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Trouxe esse video de um curso de Drug Discovery, nele pode-se aprender um pouco mais sobre a Revolução das Ômicas, avanço tecnológico, e como eles se relacionam e se ajudam no processo de descobrimento de novas drogas.

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This Course

Video Transcript

The University of California San Diego, Skaggs School of Pharmacy and Pharmaceutical Sciences Drug Discovery course brings you lectures from both faculty and industry experts. With this course, recorded on campus at UCSD, we seek to share our access to top people in the field who bring an unprecedented range of expertise on drug discovery. In this course you will learn the drug discovery process up to the filing of an Initial New Drug Application or IND. Each week you will learn the steps that a pharmaceutical or biotech company goes through to discover a new therapeutic drug. In this course you will be able to: * Understand the pharmaceutical and biotechnology market a changing landscape * Learn the major aspects of the drug discovery process, starting with target selection, to compound screening to designing lead candidates. * Recognize current modern drug discovery based on the lock-and-key theory, which attempts to use one single compound to hit one target to combat the related disease. * Increase understanding of the various drug discovery tools and methods that are used for finding, identifying and designing a new drug. * Define and understand the regulatory responsibilities for drug discovery to file an Investigational New Drug Application (IND). This course is intended as part 1 of a series: Drug Discovery, Drug Development (https://www.coursera.org/learn/drug-development) and Drug Commercialization (https://www.coursera.org/learn/drug-commercialization). We would highly recommend that you take the courses in order since it will give you a better understanding on how a drug is discovered in the lab before being tested in clinical trials and then launched in the market place.

View Syllabus

Skills You'll Learn

Pharmacology, Drug Development, Clinical Development, Pharmacokinetics

From the lesson

Drug Discovery: Proteomics, Genomics

This week we will be hearing from Phillip Bourne, PhD. Dr. Bourne was, at the time of this recording, the Associate Vice Chancellor for Innovation and Industrial Alliances in the UCSD Skaggs School of Pharmacy and Pharmaceutical Sciences. Since that time, he has been named the first Associate Director for Data Science at the United States National Institutes of Health.

Taught By

Williams S. Ettouati, Pharm.D.

Managing Director, Master of Science in Drug Development & Product Management

Joseph D. Ma

Associate Professor of Clinical Pharmacy

Transcript

[BLANK AUDIO]. Hello everyone. my name is Philip Borne. I'm actually professor in the Skaggs School of Pharmacy. I do early stage drug discovery. I'm also the associate vice-chancellor for innovation and industrial alliances here on campus. And that's a new role for me. Something since this class was given last year, and I have quite a different perspective on things than, than I had before as a result of that. And I'm not going to touch on too much of that today. But it's clearly something that is nagging at me right now in terms of how we get things out of the university. into clinical trials and of course beyond. I think there's some huge challenges there. And I've, I've heard a bit about, you've touched on that already. And perhaps we can talk about that at the end. Okay, so I'm going to focus on the idea of Proteomics and Genomics and what that brings. and how that's perturbing the drug discovery process. And I would say that you've kind of heard a bit of this, let me just cast it in my own way. By saying it's the best of times and in someways it's the worse of times. And I love this, this is the opening paragraph from Charles Dickens book. And it's so at [UNKNOWN] for drug discovery, it's unbelievable. It was the best of times, it was the worst of times, it was the age of wisdom. And I think Genomics and Prodiomics is kind of giving us. The age of wisdom, but it is also the age of foolishness in how we've so far been out, to take a lot of that forward. Because we haven't changed the way we do things in large part in the drug discovery process, even in light of this new data and these new capabilities, in my opinion. And I'll give you some illustrations of why I think that's breaking down. and I could go onto this with the winter of despair, and so on. And, but here's the sort of best of times, right? We are in this Omics Revolution. It started in about 1990, with the, with the human genome project, which took quite a long time to actually bear fruit after it was finished in 2000. But there's no question, and you asked, there's no doubt. And you asked the question about personalized medicine, that as we move down we're at, whatever it is now, three to $5,000 for a genome. A human genome, we will be down at the $50 level in the next several years. That is going to have, undoubtedly, a profound impact, on, on healthcare, in times to come. So, from that point of view, it's, it's the best of times. And we'll see what that means in terms of data and integration. And the kinds of other questions you were asking. In some ways, it's sort of the best of times, because you know we have scenes through NIH and other places. And, and the private sector large increases in research budgets. In principle spurn by the human gene among other things. To actually do better at discovering drugs. But when as you already heard, I'm sure that you'll continue to hear throughout this, the success rate is abysmal. And you know, so this is the, another sort of illustration of the best of times and the worst of times. So, putting that into words you know we have this explosion of data which in principle allows us to do a lot we, we are starting to get. And I'm going to emphasize this, we're starting to get to an understanding of complex systems in ways that we never have before. That should be impacting the drug discovery process. At this point in time, I don't think it is, but I think we're on the cusp of a turnover, and I'll say more about that. And of course the information technology that's needed to do all this, which is an area where I spend quite a lot of time myself, is obviously improving. so, let optimisim rule. So, what this all means is you know, this whole traditional model that's been based on on the computational side at least, computational chemistry and cheminformatics. We're now bringing the idea of bioinformatics, and systems biology studying the whole system particularly in silico, into play into this whole process. And the end result of that is something I would call Systems Pharmacology. And it's actually doing pharmacology in a different way than we've done before which I'll illustrate. And I'll show you a couple of examples of what I mean by that, and why I think it's so important. All right, so what's my agenda? I'll give you a little sense of you know, I think what you're going to get out of this course is because this is the nature of the game right now. You're going to get from different people, you're going to get some mixed messages. Their opinions are going to be somewhat different about where drug discovery and the whole industry's going. So, I'm just giving you my perspective. I'm going to tell you where it comes from and you can, you can take it or leave it. That's, you know, that's the business. I'll say a little bit about the Omics revolution in a bit more detail. Something about, something that I'm very passionate about, and something that I think it's also driving some change. And anything that drives change I love. So, the notion of open science, and I mentioned the IT revolution, but open science is also something that's changing. Drug companies are becoming, at some levels, much more open than they ever were before. And that's basically out of necessity, because of failure, in my opinion. Again, this is biased coming in, right. and then what impact does all that have on drug discovery? We'll look to that and I'll give you a couple of examples. Because how could I possibly stand here and not talk about my own work. Oh, people were, of course I don't actually do anything, but the work of people in the lab. and then there's, you know, a few words of caution about everything I've said, which probably means it's not true at all. All right, so this is we, what we do is, I maintain a resource, an open resource called the Protein Data Bank. Which is the repository for all meca molecular structure information, proteins DNA, RNA. and that there hasn't been a drug discovered in the last 30 years, that hasn't used that quite extensively. And that's given me a certain view point in all of this. we distribute a ton of data there are seven structures looked at every second essentially around the world. and then we've been using that ourselves in a research perspective to to do what I, already introduced to you the notion of systems pharmacology. So, you know personally I mention the open science. Also I've started some companies while I've been here, which is one of the reasons why I'm doing this associate vice chancellor job right now. because you'll learn as you go on the more you complain about something, if you complain long enough. Before you know it, you're part of the solution. So, you know trying to form companies here is not totally straightforward. having you know, finally the chance that says we don't like it, fix it. So, that's kind of what I'm trying to do right now. so that sort of some background. So, let's look at the Omics Driver. So, right now we're in a very interesting situation associated with data particular genomic data but it's true of all data in biology. and beyond for that matter. we're completely out of whack, with the ability to handle that data. So, the data there's a you know what Moore's law is? Most of you, so Moore's law is just you know a reflection of the dropping cost per some unit of computing over time. And essentially what you could do with a, a unit of computing whether it be storage or CPU was you know essentially that doubles every 18 months. And that it's gone between eight 12 and 24 months, but 18 is sort of average. And biological data of all elks, and the whole notion of translation, and having data, not just at the Omics level but at higher levels. you know, all of that data, for a long time that was essentially keeping track with paralleling, Moore's law. So, the cost of maintaining that data was essentially on par, hadn't changed over time. That is no longer true. In fact with forth generation sequencing, the new types of sequencing technologies. The amount of data far, far outweighs, you know, these are, this is an exponential scale. And you can see, you know, sequencing sort of was paralleling this for quite a while. And then, you know, first of all, were second and third and fourth generation, that's really gone completely wacky. Right now, the amount of sequence data that we're generating is doubling every five months. It's absolutely huge, and that, that doesn't speak to any of the data's of greater complexity, which I'll get to in a minute. No one is really addressing the issues of what we keep, what we throw away. We're not addressing issues associated with the complexity of that data, the errors in that data. How we represent metadata, how we represent prominence which is, how we describe the value of that data and who owns it. All of these things, are completely out of whack right now.

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Drug Discovery: Proteomics, Genomics I - Drug Discovery: Proteomics, Genomics | Coursera

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Video created by University of California San Diego for the course "Drug Discovery ". This week we will be hearing from Phillip Bourne, PhD. Dr. Bourne was, at the time of this recording, the Associate Vice Chancellor for Innovation and ...

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Olá pessoal, encontrei esse artigo muito interessante que trás um pouco da visão que estudantes de farmácia tem sobre a farmacogenômica.

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Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia

Author to whom correspondence should be addressed.

Academic Editor: Michele Rubini

Received: 3 January 2022 / Revised: 25 January 2022 / Accepted: 26 January 2022 / Published: 29 January 2022

Pharmacists are considered among the most accessible healthcare workers in fundamental positions to implement new clinical initiatives, such as pharmacogenomics services. The scope of pharmacogenomics in improving health outcomes and the quality of health care is well-known. Implementation of such initiatives requires adequate knowledge, perception, and positive attitudes among pharmacists. A study was conducted on pharmacy students at King Saud University in Riyadh to analyze their attitudes, knowledge, and perceptions concerning pharmacogenomics to explore the feasibility of establishing full-time pharmacogenomics instruction and services. A cross-sectional study was carried out in one of the significant pharmacy schools of Saudi Arabia, using a simple questionnaire-based survey in pharmacy students pursuing Bpharm and PharmD courses to obtain preliminary information about pharmacogenomics among the surveyed population. The study's secondary objective was to determine the perceived belief about pharmacogenomics implementation in clinical practice. Out of the total of 552 participants, 41.8% correctly defined pharmacogenomics and 81.3% understood that genetic change could lead to adverse reactions. More than half of the participants agreed that the FDA recommends pharmacogenomics testing for certain drugs. The knowledge about a year of use of pharmacogenomics in clinical practice was found to be very low; only 15.2% could correctly answer. Only 60% of students agreed on pharmacogenomics testing for selecting the therapy with the most negligible adverse effects. Due to the limited knowledge about and understanding of pharmacogenomics, there is a lack of interest among pharmacy students in implementing pharmacogenomics testing in clinical practice. Our study highlights the need for improving pharmacy students' knowledge about pharmacogenomics and pharmacogenetics so that the implementation of pharmacogenomics testing in clinical practice will become easier. There is a need to introduce an up-to-date curriculum for pharmacy courses other pharmacogenomics-based health education programs in Saudi Arabia. View Full-Text

Arafah, A.; Rehman, M.U.; Syed, W.; Babelghaith, S.D.; Alwhaibi, A.; Al Arifi, M.N. Knowledge, Attitude and Perception of Pharmacy Students towards Pharmacogenomics and Genetics: An Observational Study from King Saud University. Genes 2022, 13, 269. https://doi.org/10.3390/genes13020269

AMA Style

Arafah A, Rehman MU, Syed W, Babelghaith SD, Alwhaibi A, Al Arifi MN. Knowledge, Attitude and Perception of Pharmacy Students towards Pharmacogenomics and Genetics: An Observational Study from King Saud University. Genes. 2022; 13(2):269. https://doi.org/10.3390/genes13020269

Chicago/Turabian Style

Arafah, Azher, Muneeb U. Rehman, Wajid Syed, Salmeen D. Babelghaith, Abdulrahman Alwhaibi, and Mohamed N. Al Arifi. 2022. "Knowledge, Attitude and Perception of Pharmacy Students towards Pharmacogenomics and Genetics: An Observational Study from King Saud University" Genes 13, no. 2: 269. https://doi.org/10.3390/genes13020269

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Knowledge, Attitude and Perception of Pharmacy Students towards Pharmacogenomics and Genetics: An Observational Study from King Saud University

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Pharmacists are considered among the most accessible healthcare workers in fundamental positions to implement new clinical initiatives, such as pharmacogenomics services. The scope of pharmacogenomics in improving health outcomes and the quality of health care is well-known. Implementation of such initiatives requires adequate knowledge, perception, and positive attitudes among pharmacists.

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Potencial terapêutico e uso de plantas medicinais em uma área de Caatinga no estado do Ceará, nordeste do Brasil #DrugDiscovery

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Potencial terapêutico e uso de plantas medicinais em uma área de Caatinga no estado do Ceará, nordeste do Brasil #DrugDiscovery

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Esse artigo traz uma relação muito interessante entre o conhecimento popular e o científico no que diz respeito às ações terapêuticas de plantas da nossa Caatinga.

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Potencial terapêutico e uso de plantas medicinais em uma área de Caatinga no estado do Ceará, nordeste do Brasil

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O presente trabalho visou o levantamento etnobotânico das plantas medicinais, verificando a...

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Uma revisão breve sobre os possíveis benefícios da junção da farmacogenômica com os tratamentos de doenças cardiovasculares.

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A farmacogenômica (FGx) investiga a interação entre genes e medicamentos. Através da análise de regiões específicas do DNA, informações sobre o perfil de metabolização do paciente para um determinado fármaco podem ser descritas, assim como o perfil esperado de resposta ao tratamento. Objetivamente, esse tipo de teste pode ter impacto no tratamento de pacientes que não estão respondendo adequadamente a um determinado medicamento, seja pela ausência dos efeitos esperados ou em virtude do aparecimento de efeitos adversos. Neste cenário, o objetivo desta revisão é o de informar o cardiologista clínico sobre esta importante área do conhecimento e atualizá-lo sobre o tema, procurando preencher as lacunas no que diz respeito à relação custo-benefício da aplicação da FGx nas doenças cardiovasculares, além de fornecer informações para a implementação da terapia guiada pela FGx na prática clínica.

Palavras-chave
Doenças Cardiovasculares; Genes; Hereditariedade; Genoma; Perfil Genético; Farmacogenética; Biotransformação; Tratamento Farmacológico/eventos adversos; Saúde Pública

A farmacogenômica (FGx) é a ciência que estuda a interação entre genes e medicamentos. A partir da análise de regiões específicas do DNA, é possível obter informações sobre, por exemplo, o perfil de metabolização do paciente para um determinado fármaco, bem como o perfil esperado de resposta ao tratamento. A FGx também visa diminuir a ocorrência de eventos adversos aos medicamentos (EAM)., As inúmeras pesquisas nesta área têm focado na identificação de genes que predispõem às doenças, modulam respostas aos fármacos, e afetam a concentração e a ação desses medicamentos, além de se associarem a reações adversas. É frustrante saber que a eficácia de alguns tratamentos medicamentosos varia entre 25% a 80%, sendo que somente um terço dos pacientes expostos ao uso de diferentes tipos de fármacos obtém os benefícios terapêuticos desejados.

A ocorrência de EAM constitui um problema de saúde pública no mundo todo, pois aumenta significativamente o tempo de hospitalização, além de ter sido considerada como a quarta dentre as seis causas mais frequentes de morte nos Estados Unidos nos últimos 20 anos., Lá, por exemplo, mais de dois milhões de pessoas são hospitalizadas e pelo menos 55.000 morrem por ano em decorrência da não resposta ao tratamento ou de EAM. No Brasil, os dados ainda são escassos, e a FGx pode ser uma ferramenta de auxílio tanto no tratamento do paciente quanto na otimização dos gastos financeiros. Foi evidenciado que no Hospital de Clínicas de Porto Alegre, Brasil, 14% dos pacientes procuraram a emergência por EAM, e as classes de medicamentos mais envolvidas foram os antirretrovirais, os anticoagulantes, e os anti-hipertensivos. Daqueles que procuraram a emergência uma primeira vez, 20-30% retornaram. Os pesquisadores evidenciaram que o custo médio para tratar um paciente por EAM durante um ano foi de R$ 2200,00, sendo o custo total de 18 milhões de reais.

A doença cardiovascular (DCV) é a principal causa de morte no mundo, contribuindo significativamente para o crescente ônus econômico na área da saúde. Em 2016, 31% de todas as mortes no mundo (17,9 milhões) foram causadas por DCVs; aproximadamente 555 bilhões de dólares foram gastos nos Estados Unidos, e as previsões informam que esses custos aumentem para US$ 1,1 trilhão no ano 2035.

Sabemos que existem várias classes de medicamentos para reduzir o risco de DCV, como também existe uma variação significativa na resposta ao tratamento. Além da variação que pode ser atribuída a diversas características sociodemográficas, há determinantes genéticos da droga, assim como respostas que podem afetar a maneira como as drogas são metabolizadas, absorvidas e distribuídas.14. Johnson JA, Cavallari LH. Pharmacogenetics and cardiovascular disease--implications for personalized medicine. Pharmacol Rev. 2013;65(3):987-1009. 17. Lee MS, Flammer AJ, Lerman LO, Lerman A. Personalized medicine in cardiovascular diseases. Korean Circ J. 2012;42(9):583-91. ,¹⁴
¹⁷

18. Joyner MJ. Precision medicine, cardiovascular disease and hunting elephants. Prog Cardiovasc Dis. 2016;58(6):651-60.
15. Peters BJM, Klungel OH, de Boer A, Ch Stricker BH, Maitland-van der Zee AH. Pharmacogenetics of cardiovascular drug therapy. Clin Cases Miner Bone Metab. 2009;6(1):55-65. ⁻ Portanto, dados genéticos podem ser usados para identificação e avaliação das respostas a doses de drogas, controle de efeitos colaterais e também para previsão de resultados.⁻ Nos últimos anos, devido ao desenvolvimento na clonagem de genes, na genotipagem e no sequenciamento de DNA, a FGx emerge como um componente útil. O conhecimento atual pode ser aplicado em um gene individual, em uma área terapêutica ou em medicamento específico: a) uso de testes FGx para prever a dose individual de medicamento; b) uso de testes FGx para prever a ausência de resposta a um medicamento; e c) uso de testes FGx para prever indivíduos com sério risco de toxicidade se um medicamento for prescrito ou administrado.

Várias diretrizes clínicas nessa área do conhecimento estão disponíveis, sendo as principais delas: o Clinical Pharmacogenetics Implementation Consortium (CPIC), o Dutch Pharmacogenetics Working Group (DPWG), o Canadian Pharmacogenomics Network for Drug Safety (CPNDS), o Groupe de Pharmacologie Clinique Oncologique (GPCO/Unicancer), o Réseau National de Pharmacogénétique Hospitalière (RNPGx), e o American College of Rheumatology (ACR).

Um Pouco de História

Umas das primeiras terapias baseadas em uma mutação específica, que mudaram significativamente o prognóstico de doenças, são o trastuzumab no câncer de mama HER-2 positivo e o imatinibe na leucemia mieloide crônica., Desde então, a oncologia aposta progressivamente na utilização da informação genética, e atualmente esta serve para pautar a decisão terapêutica, tendo incluído o teste genômico em 39% dos ensaios clínicos de oncologia em 2018. Além da oncologia, inúmeras outras áreas identificaram ou aprimoraram tratamentos baseados em variações genéticas. Para a fibrose cística já foram identificadas mais de 100 mutações causadoras, o que, apesar de dificultar o desenvolvimento de tratamento específico para cada variante, possibilitou o agrupamento dos seus subtipos que parecem responder a tratamentos semelhantes.

Os avanços da medicina genômica não se limitam apenas a drogas que agem a nível proteico. Técnicas como o CRISPR ( clustered regularly interspaced short palindromic repeats) - uma região especializada do DNA - são usadas para silenciar genes e evitar o desenvolvimento de doenças em embriões e/ou modificar genes relacionados à doença em adultos. Essas técnicas são parte do que se conhece como terapia genética e, apesar de estarem em fase embrionária, são esperadas como alternativas potencialmente revolucionárias.

Metabolização de Medicamentos

* Metabolizadores Lentos

* Metabolizadores intermediários

* Metabolizadores rápidos

* Metabolizadores ultrarrápidos

O gene CYP2D6, especificamente, é responsável pelo metabolismo em cerca de 25% dos medicamentos prescritos, e possui alelos que podem causar os quatro tipos de metabolismo descritos anteriormente. Estes alelos têm uma prevalência que varia de acordo com a etnia. Por exemplo, um dos principais alelos não funcionais conhecidos, o CYP2D6*4, tem prevalência estimada de 25% em indivíduos caucasianos; já o alelo CYP2D6*10 e CYP2D6*17 (ambos de função reduzida) são mais comuns em africanos e asiáticos, com uma frequência alélica de aproximadamente 40%.

Ensaios Clínicos Randomizados

Diversos estudos vêm sendo realizados nos últimos anos para testar o papel da FGx na prática clínica. Em um ensaio clínico randomizado (ECR), 1.956 pacientes infectados pelo vírus da imunodeficiência humana (HIV) foram divididos em dois grupos. O primeiro foi rastreado prospectivamente quanto à presença do alelo HLA-B*5701 e, aqueles positivos, não receberam o antiviral abacavir. O outro grupo recebeu tratamento padrão com abacavir sem rastreamento prospectivo quanto à presença de HLA-B*5701 (grupo controle). A incidência de hipersensibilidade ao medicamento foi menor no grupo que passou pelo rastreamento genético (3,4%) em comparação ao grupo controle (7,8%). Este resultado levou a Food and Drug Administration (FDA) dos Estados Unidos a incluir a exigência do teste FGx na bula do medicamento. Mais recentemente, o estudo de Smith et al. evidenciou redução de 30% na intensidade de dor em usuários crônicos de opioide quando a terapia era guiada pela presença da variante no gene CYP2D6. Uma meta-análise, incluindo cinco ECRs, encontrou 1,71 mais chance de remissão de sintomas em pacientes recebendo terapia guiada por genotipagem quando comparada à terapia usual.

Focando na área de DCVs, os estudos mais numerosos são relacionados aos antiagregantes plaquetários e aos anticoagulantes. Após observações retrospectivas de que a presença de variantes genéticas classificadas como perda de função apresentava impacto nos efeitos do clopidogrel, iniciativas surgiram para avaliar o benefício de incluir o teste de forma rotineira. Investigadores da Implementing Genomics in Practice (IGNITE) evidenciaram em um grupo de 1.815 pacientes, maior taxa de eventos cardiovasculares naqueles com variantes de perda de função do gene CYP2C19 e em uso de clopidogrel, comparado com antiplaquetários alternativos, como o prasugrel ou o ticagrelor (hazard ratio [HR] 2,26, intervalo de confiança [IC] 95% 1,18-4,32; p=0,013). Outro ECR mostrou diminuição importante nos eventos coronarianos tardios com a implementação da estratégia FGx para uso do clopidogrel.

Já em relação à varfarina, a maioria dos estudos avaliou variantes genéticas ligadas ao seu metabolismo nos genes CYP2C9 e VKORC1. O European Pharmacogenetics of anticoagulant therapy (EU-PACT) mostrou que, guiando a terapia pelo teste genético, houve aumento significativo no tempo em que os pacientes mantinham-se com um INR ( International Normalized Ratio) dentro da faixa terapêutica (2,0-3,0). Mais recentemente, o estudo Genetics Informatics Trial of Warfarin to Prevent Deep Vein Thrombosis (GIFT) mostrou diminuição de sangramentos significativos, tromboembolismo venoso e morte no período perioperatório em pacientes com terapia guiada por FGx para cirurgias eletivas de implante de próteses de quadril e de joelho. Ambos os estudos citados relacionados à varfarina incluíram uma população majoritariamente branca e, por isso, há a necessidade de se incluir variantes do CYP2C9 mais comuns em populações de ascendência africana para obtenção de resultados mais acurados relacionados a esse grupo populacional. Por sua vez, o maior dos estudos da varfarina, o Clarification of Optimal Anticoagulation Through Genetics (COAG) mostrou-se diferente dos demais e relatou não haver diferença em se iniciar terapia com varfarina guiada por informação clínica ou guiada pela pesquisa de variantes do gene CYP2C9, as quais são muito mais comuns em população de ascendência europeia, em uma coorte composta apenas por 27% de afro-americanos. Por outro lado, e considerando o custo-benefício relacionado ao uso da varfarina e do clopidogrel, uma revisão sistemática recente que incluiu 31 ECRs mostrou que, comparado à terapia padrão, o teste FGx foi superior em 81% das vezes.

Paralelamente aos estudos de medicamentos isolados, o conceito de teste preventivo vem crescendo e apresentando algumas evidências de benefício. Em 2012, Schildcrout et al. mostraram, em uma coorte de 52.942 pacientes em cuidado domiciliar, uma exposição de 64,8% a pelo menos um medicamento de mecanismo influenciado por variantes genéticas. Os autores estimaram em 398 o número de eventos adversos potenciais que poderiam ter sido evitados com a genotipagem preventiva. Já o estudo do genótipo de 44.000 participantes do biobanco da Estônia mostrou que 99,8% desses indivíduos tinham genótipo associado a um risco aumentado a pelo menos uma medicação. Com resultados concordantes, o protocolo RIGHT ( 'Right Drug, Right Dose, Right Tim eUsing Genomic Data to Individualize Treatment') criado pela clínica Mayo/iniciativa eMERGE, sequenciou painel incluindo os genes SLCO1B1 (membro da família do transportador de ânions orgânicos transportadores de soluto 1B1), CYP2C19, CYP2C9, VKORC1 e CYP2D6. Eles identificaram em 99% dos 1.013 indivíduos pelo menos uma variante de risco para uso de algum medicamento.

Nos Estados Unidos, medicamentos com recomendações relacionadas à FGx perfazem 18% de todas as prescrições e 30% dos medicamentos com alto risco FGx mais prescritos representam 738 milhões de prescrições por ano. Tais informações vão à direção de que parece existir um impacto positivo do teste FGx preventivo, não apenas pelo aumento da eficácia terapêutica e custo-benefício, mas também pelo seu potencial de evitar EAMs. Além dos dados já mencionados, um estudo holandês também mostrou benefício pela redução de 73% para 28% no risco de na taxa de intoxicação por fluoropirimidinas em pacientes com dose guiada por genotipagem, além da redução das mortes induzidas pelo medicamento de 10% para 0%.

Importância da Farmacogenômica

Diferentes são os benefícios que podem ser alcançados com o advento da FGx, a citar:

Além disso, a FGx pode contribuir para redução geral no custo dos cuidados de saúde, conforme apresentado na Figura 1. É importante mencionar que quase 200 mil mortes/ano na Europa são relacionadas aos EAM, com um custo de aproximadamente 80 bilhões de euros.

Estima-se que uma boa parcela dos pacientes não apresenta respostas consideradas satisfatórias aos medicamentos., Nesse sentido, a FDA recomenda, por exemplo, que testes FGx sejam realizados antes da quimioterapia com a droga mercaptopurina - utilizada comumente para pacientes com alguns tipos de leucemia aguda. Tal recomendação baseia-se no fato de que, como esta droga pode causar efeitos colaterais graves e aumentar o risco de infecção a depender da variante genética do indivíduo, a terapia pode não surtir o efeito desejado.

O Genomics and Targeted Therapy Group, um braço do departamento de Farmacologia Clínica da FDA, tem como objetivo garantir a aplicação apropriada das estratégias FGx por meio das suas funções de revisão regulatória, pesquisa, desenvolvimento de diretrizes e educação profissional. Parte desse trabalho incluiu a criação de uma tabela agrupando as orientações farmacológicas das 161 drogas, que até o momento contém informações genômicas em seus rótulos. Sua última atualização traz números expressivos de biomarcadores associados a drogas em diversas áreas da medicina, inúmeras delas amplamente utilizadas na prática clínica ( Tabela 1).

Por fim, espera-se que, em breve, a FGx seja mais acessível e que a sua utilização consciente possa contribuir para que os médicos prescrevam as medicações com maior "acurácia" e os pacientes possam recebê-las com maior chance de sucesso terapêutico aliado ao menor risco de EAM.

Associação entre Variantes Genéticas e Respostas aos Medicamentos na Doença Cardiovascular

É de amplo conhecimento que fatores como idade, comorbidades, peso, bem como aqueles demográficos, podem contribuir para diferenças significativas nas respostas a uma mesma terapia farmacológica, bem como ao desenvolvimento de EAM., Nesse contexto, a variação genética pode representar um pilar fundamental para esse desfecho. Acredita-se que muitas mortes ao redor do mundo poderiam ter sido evitadas se o médico tivesse conhecimento prévio do perfil FGx dos pacientes, e pudesse empregar a medicação em doses corretas para aquele indivíduo. Pacientes com um mesmo diagnóstico (por exemplo, infarto agudo do miocárdio) são normalmente tratados da mesma maneira, embora suas respostas à terapia medicamentosa possam ser distintas. A "terapia sob medida" pode reduzir os EAMs e aumentar as taxas de eficácia, conforme ilustrado na Figura 2. Por exemplo, há uma enorme variação na dose diária necessária de um dos anticoagulantes mais utilizados na prática clínica, a varfarina, podendo variar em até 20 vezes. Por sua vez, o propranolol (betabloqueador) pode ter a sua dose variando em até 40 vezes a depender de qual paciente esteja recebendo a droga. Alguns fármacos utilizados em larga escala na prática clínica do cardiologista, os quais podem ter importantes associações genéticas, são apresentados na Tabela 2.

Varfarina

A varfarina é um fármaco pertencente à classe dos antagonistas da vitamina K, e vem sendo utilizada em grande escala na prevenção de eventos trombóticos. Evidências sugerem que a resposta do indivíduo à varfarina, bem como a outros antagonistas da vitamina K, pode ser influenciada de forma importante por variações genéticas na enzima hepática do citocromo P450 (CYP2C9) e na Subunidade 1 do complexo Epóxido Redutase da Vitamina K (VKORC1), alvo para estes fármacos,, além de polimorfismos no membro 2 da subfamília F e família 4 do citocromo P450 4 (CYP4F2). Foi demonstrado que variações nos alelos CYP2C9*2 e CYP2C9*3 diminuíram a atividade enzimática da CYP2C9 e inibiram o metabolismo anticoagulante, enquanto o polimorfismo VKORC1- 1639G>A parece ter influência na resposta farmacodinâmica aos antagonistas da vitamina K. Devido a essas observações, a FDA apontou a necessidade de informações FGx na bula da varfarina.

Na prática, os portadores heterozigotos dos alelos de função reduzida CYP2C9*2 ou CYP2C9*3 podem necessitar de uma dose reduzida de varfarina em cerca de 30% e 47%, respectivamente, enquanto os portadores homozigotos CYP2C9*3 podem necessitar reduções ainda maiores (~80%).69. Sconce EA, Khan TI, Wynne HA, Avery P, Monkhouse L, King BP, et al. The impact of CYP2C9 and VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements: proposal for a new dosing regimen. Blood. 2005;106(7):2329-e33. ⁶⁹

70. Higashi MK, Veenstra DL, Kondo LM, Wittkowsky AK, Srinouanprachanh SL, Farin FM, et al. Association between CYP2C9 genetic variants and anticoagulation-related outcomes during warfarin therapy. JAMA. 2002;287(13):1690e8. ⁻ Por sua vez, a variante -1639 G>A do gene VKORC1 parece reduzir a expressão de proteínas, o que teoricamente representa uma dose menor de manutenção de varfarina em comparação com os não portadores desta variante. Da mesma forma, combinações de algumas variantes associadas a um metabolismo extremo tornam mais difícil a obtenção de um INR terapêutico de maneira sistemática nesses pacientes. Nesse cenário, as diretrizes do CPIC recomendam considerar um anticoagulante oral de ação direta (por exemplo, edoxabana).

Clopidogrel

Nos Estados Unidos, estima-se que mais de três milhões de indivíduos recebam anualmente prescrição de clopidogrel após a colocação de um stent. Ele é um fármaco tienopiridínico do grupo dos antiagregantes plaquetários. A resposta do indivíduo frente ao clopidogrel pode sofrer alteração, determinada pelo polimorfismo do CYP2C19.

A variante de perda de função do CYP2C19*2 foi associada a um risco aumentado de eventos cardiovasculares adversos, incluindo trombose de stent durante o tratamento com clopidogrel. Mais especificamente, o alelo CYP2C19*2 (rs4244285) causa perda de função e foi associado à redução na atividade antiagregante do medicamento. Além disso, portadores do alelo CYP2C19 *3 (rs4986893) também têm respostas reduzidas ao clopidogrel e uma taxa mais alta de eventos cardiovasculares adversos recorrentes em comparação com não portadores., É importante mencionar que as frequências dos alelos CYP2C19 *2 e CYP2C19 *3 são mais altas nas populações asiáticas, sugerindo que estes indivíduos têm maior probabilidade de serem resistentes à terapia com esta droga. Em contraste, o alelo CYP2C19*17 (rs3758581) promove ganho de função e tem sido associado ao aumento da atividade enzimática e à melhor inibição das plaquetas. Os portadores da variante CYP2C19*17 foram denominados metabolizadores ultrarrápidos.

A raça parece ser outro fator com papel importante nesse cenário. Cresci et al. compararam o efeito do polimorfismo do CYP2C19 sobre eventos CVs adversos entre pacientes com infarto agudo do miocárdio em caucasianos e afro-americanos tratados com clopidogrel. Foi observado que o alelo CYP2C19*2 teve associação significativa com aumento da taxa de mortalidade em um ano e a uma tendência no aumento na incidência de infarto do miocárdio recorrente em caucasianos. Já o alelo CYP2C19*17 foi associado a um aumento na mortalidade em um ano e a um risco aumentado de sangramento em afro-americanos. É importante mencionar que pacientes submetidos à intervenção coronária percutânea que possuem pelo menos um alelo CYP2C19*2 podem apresentar maior risco de trombose de stent. Em um ECR, aproximadamente 2.500 pacientes foram pré-tratados uniformemente com 600 mg de clopidogrel. Os portadores do alelo CYP2C19*2 apresentaram um aumento significativamente maior na incidência de trombose de stent em 30 dias, quando comparados com os portadores do alelo CYP2C19 de tipo selvagem. Nessa mesma linha, a meta-análise conduzida por Mega et al., que arrolou estudos com pacientes mais complexos e em tratamento agressivo, encontrou um risco aumentado de trombose de stent quando o alelo *2 foi identificado pela FGx.

Na atualidade, o American College of Cardiology em conjunto com a American Heart Association também não recomenda testes de FGx de rotina para o CYP2C19. No entanto, outra meta-análise mais recente demonstrou que os pacientes que se beneficiam do estudo FGx são aqueles com doença arterial coronária que são submetidos a procedimentos de revascularização miocárdica percutânea. Nesse contexto, o CPIC recomenda formalmente que pacientes com síndrome coronária aguda, ou ainda, aqueles submetidos à intervenção coronária percutânea, sejam submetidos ao teste FGx. O CPIC enfatiza que aqueles que possuem uma ou duas cópias do alelo com perda de função devem receber agentes antiplaquetários alternativos (como prasugrel ou ticagrelor), a fim de reduzir o risco de eventos cardiovasculares adversos. Por outro lado, outras populações de pacientes (por exemplo, fibrilação atrial), nas quais o uso do clopidogrel é mais discutível, o painel FGx não está indicado.

Recentemente, os resultados do ECR TAILOR PCI foram apresentados. Este estudo avaliou uma estratégia guiada por genótipo (n = 2.652) versus terapia padrão (n = 2.650) em pacientes com doença arterial coronariana estável ou instável submetidos à intervenção coronária percutânea com objetivo de orientar a terapia antiplaquetária. No grupo randomizado para estratégia guiada por genótipo, os pacientes submetidos à genotipagem receberam ticagrelor 90 mg duas vezes ao dia (portadores de um alelo CYP2C19 *2 ou *3) ou clopidogrel 75 mg diariamente. No grupo denominado terapia padrão, os sujeitos receberam 75 mg de clopidogrel diariamente e passaram por genotipagem somente após 12 meses. O desfecho primário era composto por morte cardiovascular, infarto do miocárdio, acidente vascular cerebral, trombose de stent ou isquemia recorrente em 12 meses. O desfecho primário e a incidência de sangramento não foram diferentes entre os grupos de tratamento. Entretanto, cabe ressaltar a redução de 34% nesses eventos em um ano, bem como uma redução significativa de 40% no número total de eventos por paciente no braço guiado por FGx. Por fim, uma análise post hoc encontrou uma redução de aproximadamente 80% na taxa de eventos adversos nos primeiros três meses de tratamento nos pacientes randomizados para terapia guiada por genótipo.,

Betabloqueadores

Essa classe de drogas é amplamente utilizada para o tratamento de arritmias cardíacas, angina, infarto do miocárdio e hipertensão. Os genes associados à resposta inter individual do betabloqueador incluem o CYP2D6, o adrenoceptor beta 1 (ADBR1), o adrenoceptor beta 2 (ADBR2) e o receptor quinase 5 acoplado à proteína G (GRK5). Por exemplo, alguns betabloqueadores, incluindo propranolol e o metoprolol, são metabolizados pelo CYP2D6, e a perda de função desta variante é muito comum. Por sua vez, evidências sugeriram que pacientes hipertensos portadores do alelo Arg389 tipo selvagem homozigoto obtiveram três vezes maior redução da pressão arterial diastólica diurna com o uso do metoprolol quando comparados aos portadores do alelo Gly389. Embora com resultados ainda não tão consistentes, pacientes que são homozigotos do haplótipo Arg389 do ADBR1 parecem apresentar uma resposta mais satisfatória a toda a família dos betabloqueadores, apresentando melhor fração de ejeção do ventrículo esquerdo quando comparados aos portadores do alelo Gly389.

Assim, no cenário da insuficiência cardíaca, ainda não há recomendações para o uso de informações FGx que visem orientar o uso de betabloqueadores.

Estatinas

Possíveis Barreiras à Implementação da Farmacogenômica

Graças ao avanço da tecnologia e das técnicas de sequenciamento, o custo da avaliação FGx diminuiu significativamente nos últimos anos (Lei de Moore), facilitando seu uso na prática clínica; porém, o custo relativamente elevado ainda representa uma barreira para a implementação mais ampla dessa ferramenta. Além disso, uma possível falta de familiaridade dos profissionais da saúde, a ausência de uma plataforma padronizando a investigação e o pensamento acadêmico e, de uma forma geral, o fato de que o volume de estudos que demonstram os benefícios da FGx ainda é insuficiente, são fatores que contribuem para uma baixa aceitação por parte da comunidade científica da inclusão de testes FGx na prática clínica.

No entanto, esforços para contornar esses obstáculos ocorrem atualmente de forma global e contam com estudos de grandes proporções, tais como, o UK's 100.000 Genomes Project e o PREemptive Pharmacogenomic testing for prevention of Adverse drug REactions (PREPARE), o qual conta com a participação de sete países na Europa. No outro lado do Atlântico Norte, nos Estados Unidos, o Electronic Medical Records and Genomics (eMERGE), o Network and the Implementation of Genomics in Practice (IGNITE), e o Clinical Sequencing Evidence Generating Research Consortium, são parte de uma série de projetos custeados pelo National Human Genome Research Institute, sendo estimado um investimento na pesquisa genética de pelo menos US$ 775 milhões no período de 2007-2022. Na Ásia, o programa South East Asian Pharmacogenomics Research Network (SEAPharm) inclui cinco países para conduzir estudos de FGx. De forma geral, estes estudos visam definir, gerar e analisar evidências sobre a utilidade clínica do sequenciamento genômico para guiar terapia, custo-eficácia e o valor de sua implementação de forma vasta na prática médica. Dos resultados já obtidos, uma revisão que incluiu 44 avaliações de custo-benefício, mostrou que 30% delas mostrou custo-efetividade e 27% evidenciou até redução de custos, o que contribui para uma perspectiva otimista para o futuro da FGx.

Entre inúmeras contribuições das iniciativas globais para a expansão da FGx na prática clínica, vale destacar um de seus aspectos cruciais: a educação e o treinamento dos profissionais de saúde e a promoção e estímulo ao investimento em tecnologia nos centros de pesquisa e assistência. Além da contribuição com a literatura, os projetos promovem o treinamento de pessoas para a prática adequada da medicina genômica, a qual exige a adoção de atitudes básicas que talvez sejam menos relevantes em outras especialidades. Exemplos são a inclusão da família do paciente no aconselhamento e no plano de tratamento, além da confidencialidade que assegura o uso de informações genéticas com propósitos exclusivamente assistenciais (evitando seu uso inapropriado para imposição da lei, seguros, marketing ou relação empregatícia). A educação e treinamento têm papel central para a aceitação da medicina genômica na prática clínica, e a aceitação por sua vez é ponto chave para sua implementação. O esforço para geração de dados contribui significativamente, mas a disposição e engajamento dos profissionais da área da saúde que almejam a excelência da assistência médica são indispensáveis. A dimensão e o progresso dos esforços e investimentos que ocorrem globalmente deixam clara a relevância e o potencial atribuídos à medicina genômica, que já pode ser considerada parte da prática médica de alta qualidade e um dos pilares da medicina de precisão.

1. 1)
Áreas de consenso: o teste FGx pode ser útil para o uso otimizado de diversos medicamentos, permitindo uma maior segurança farmacológica;

2. 2)
Áreas de controvérsia: se os testes FGx devem ser aplicados mais amplamente, inclusive na prescrição de certos medicamentos em que o benefício geral é menos claro, permanece controverso;

3. 3)
Área de crescimento: cada vez mais, as informações pessoais sobre genótipos são disponibilizadas diretamente ao consumidor. Isso provavelmente aumentará a demanda por prescrição personalizada, significando que os prescritores precisam levar em consideração as informações FGx. Como exemplo, podemos citar o Projeto 100.000 genomas. Este impressionante projeto fornecerá sequências genômicas completas que podem fazer parte de um prontuário médico do paciente. Esta informação parece ser de grande valor na prescrição personalizada;

4. 4)
Áreas oportunas para o desenvolvimento de pesquisas: desenvolvimento de novos medicamentos visando fatores de risco genéticos específicos para doenças. Estes podem ser prescritos para aqueles com genótipo de risco. É provável que as informações FGx estejam disponíveis rotineiramente no futuro, especialmente em ambientes tecnologicamente avançados. Isso poderia influenciar a prescrição de uma variedade de medicamentos além daqueles para os quais, atualmente, são necessários testes antes da prescrição.

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Farmacogenômica e Doença Cardiovascular: Onde Estamos e Para Onde Vamos

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A farmacogenômica (FGx) investiga a interação entre genes e medicamentos. Através da análise de regiões específicas do DNA, informações sobre o perfil de metabolização do paciente para um determinado fármaco podem ser descritas, assim como o perfil esperado de resposta ao tratamento.

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O mercado brasileiro de anticorpos monoclonais utilizados para o tratamento do câncer #anticorpos

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O mercado brasileiro de anticorpos monoclonais utilizados para o tratamento do câncer #anticorpos

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Oi pessoal! Trago um artigo curto que analisa o mercado brasileiro de anticorpos usados no tratamento do câncer.

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Os mABs, proteínas cujo mecanismo de ação é complexo, são imunoglobulinas derivadas de um mesmo clone de linfócito B, cuja clonagem e propagação se efetuam em linhas de células contínuas . São produzidos para reagir com antígenos específicos de certos tipos de células, tendo maior capacidade de preservar as células saudáveis quando comparados às terapias citotóxicas padrão . Por isso, os anticorpos têm sido indicados como a tecnologia inovadora para o tratamento de alguns tipos de câncer e promissora no que diz respeito à possibilidade de alvejar e matar seletivamente células tumorais .

Dentro desse mercado americano, os anticorpos monoclonais foram, naquele ano, a classe mais vendida. Os mABs movimentaram 24,6 bilhões de dólares, com a liderança da Roche, dentre as empresas produtoras de biológicos, detendo 11 anticorpos monoclonais no mercado. Esse crescimento foi impulsionado principalmente pelas vendas no setor oncológico . As estimativas indicam que, até 2020, os medicamentos oncológicos movimentarão mais de 100 bilhões de dólares em mercados farmacêuticos desenvolvidos e emergentes .

Segundo a Organização Mundial da Saúde (OMS), os custos com os novos medicamentos para câncer mais que dobraram entre os anos de 2005 e 2015, sem necessariamente representarem um aumento significativo na sobrevida dos pacientes . Nos Estados Unidos, em 2008, um tratamento de 18 semanas de um único paciente com o mAB cetuximabe já custava, em média, cerca de 80 mil dólares. Da mesma forma, o bevacizumabe custava, em média, para tratar um único paciente com câncer de mama metastático, 90 mil dólares ,.

A crescente absorção desses produtos pelo mercado não é exclusividade dos Estados Unidos. No Brasil, os medicamentos biológicos são responsáveis por um percentual elevado das compras do Ministério da Saúde, devido não apenas à adoção crescente desses produtos como opção terapêutica de primeira linha, mas também ao alto valor agregado dessa classe de medicamentos . O envelhecimento populacional, a alta carga das doenças crônicas, dentre elas o câncer, e o direito à assistência farmacêutica garantido pela Constituição Federal de 1988 têm, segundo Tanaka & Amorim , pressionado a incorporação e a compra pública dos medicamentos produzidos pela rota biotecnológica.

Os mABs são medicamentos biológicos de importância no tratamento do câncer. Porém, esses altos custos dos tratamentos podem apontar para uma falta de competitividade de mercado, decorrente de uma possível concentração produtiva, fazendo com que o acesso a essas terapias pelos usuários do sistema de saúde se torne limitado pelos altos preços praticados . O cenário dos medicamentos patenteados é cada vez mais restritivo, sendo necessário que se pressione o governo, no sentido de assegurar a redução dos preços praticados pelas empresas que detêm monopólio de mercado e, com isso, que seja possível assegurar o acesso universal à saúde . Nesse âmbito, a busca por incentivo à concorrência aparece como estratégia de redução de preços. No entanto, tem-se ainda muito que caminhar no sentido de extrapolar barreiras patentárias e aspectos regulatórios .

A entrada dos mABs em alguns mercados no mundo não se faz da mesma maneira, sendo influenciada por diversos fatores não só técnico-científicos, mas também mercadológicos. Este trabalho teve como objetivo identificar as principais características dos mABs destinados ao tratamento de câncer, com registro sanitário ativo, no Brasil, em 2016.

A planilha de preços de medicamentos não indica explicitamente quais são os mABs. No entanto, foi possível identificá-los a partir do conhecimento da nomenclatura desses medicamentos. Os mABs possuem nomes terminados com o sufixo " mab" (em português, "mabe"), que significa monoclonal antibody (anticorpo monoclonal) . Todos os anticorpos foram categorizados pelo sistema de classificação de fármacos ATC/DDD Index ( Anatomical Therapeutic Chemical and Defined Daily Dose) da OMS ( https://www.whocc.no/atc_ddd_index/, acessado em 21/Dez/2016).

As variáveis de interesse coletadas foram: nome do produto biológico, antígeno-alvo, tipo de anticorpo, ano de registro, indicações terapêuticas e empresa detentora do registro. A principal fonte de dados foi a página de Internet da Anvisa, na seção de consulta às informações de registro ( http://www7.anvisa.gov.br/datavisa/consulta_produto/Medicamentos/frmConsultaMedicamentos.asp), bulário eletrônico ( http://www.anvisa.gov.br/datavisa/fila_bula/index.asp) e consulta à situação de documentos técnicos ( http://consultas.anvisa.gov.br/#/documentos/tecnicos).

Esta pesquisa utilizou apenas dados de domínio público de acesso irrestrito sobre medicamentos, não havendo identificação de sujeitos nem envolvimento de seres humanos. Por essa razão, foi dispensada de apreciação ética pelo Comitê de Ética em Pesquisa da Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz (CAAE 571745165.0.0000.5240).

Foram identificados 34 mABs em comercialização no Brasil em setembro do ano de 2016, sendo 14 (41%) deles do subgrupo químico da ATC L01XC, referente aos mABs, destinados ao tratamento de neoplasias e de interesse deste estudo. O Quadro 1 sintetiza todos os mABs registrados no Brasil com o respectivo código ATC e grupo terapêutico.

Outros 14 anticorpos (41%) também foram classificados, no nível 1, no mesmo grupo anatômico principal, representado pela letra L (agentes antineoplásicos). No entanto, como pertencem ao subgrupo terapêutico dos imunossupressores (L04) e não eram indicados para o tratamento de câncer no Brasil, foram excluídos deste estudo. São eles: natalizumabe, belimumabe, vedolizumabe, alentuzumabe, infliximabe, adalimumabe, certolizumabe pegol, golimumabe, basiliximabe, ustequinumabe, tocilizumabe, canaquinumabe, secuquinumabe e siltuximabe.

No total, 82% dos anticorpos identificados são agentes antineoplásicos ou imunossupressores. Os outros seis (18%) mABs encontrados na lista da CMED pertencem a grupos anatômicos que não o dos agentes antineoplásicos e imunomoduladores, tais como: sangue e órgãos hematopoiéticos (B), sistema cardiovascular (C), anti-infecciosos para uso sistêmico (J), sistema musculoesquelético (M), sistema respiratório (R) e órgãos sensoriais (S). O Quadro 2 traz os mABs incluídos neste estudo e as características encontradas para eles.

A maior parte dos mABs selecionados para este estudo são humanizados (43%), ou seja, são caracterizados por possuírem as regiões hipervariáveis do anticorpo de camundongo e, o restante, da estrutura de anticorpo humano ,.

Foram identificados sete antígenos-alvos diferentes, sendo os principais os seguintes: EGFR, CD20 e HER2. No que diz respeito às indicações clínicas para as quais esses biológicos eram direcionados, observou-se uma maior frequência de linfomas, leucemias e também de cânceres de mama, cólon e reto.

Quanto ao tipo, foram identificados três mABs quiméricos (brentuxumabe vedotina, cetuximabe e rituximabe), seis humanizados (bevacizumabe, nimotuzumabe, obitunuzumabe, pertuzumabe, trastuzumabe e trastuzumabe entansina) e cinco do tipo humano (ipilimumabe, nivolumabe, ofatumumabe, panitumumabe e ramucirumabe). Foi possível observar anticorpos resultantes de três tecnologias de produção diferentes - quimérico, humanizado e humano - para os mesmos alvos.

Quanto às empresas detentoras de registro, foi possível observar que a Roche detém o registro de seis mABs, o que representa 43% dos mABs registrados para o tratamento de câncer existentes no mercado brasileiro. Em segundo lugar, com dois anticorpos (15%), destaca-se a Bristol-Myers Squibb. Os outros seis mABs são registrados por seis empresas diferentes.

O CTLA-4 (antígeno 4 associado ao linfócito T citotóxico) é um regulador-chave das células T. Ao se ligarem a esse antígeno, os anticorpos bloqueiam os sinais inibitórios dessas células, reduzindo, então, o número de células T reguladoras e aumentando o número das células T efetoras reativas ao tumor que, por sua vez, mobilizam-se para promover um ataque direto às células tumorais ,.

O CD 20 ( cluster de diferenciação 20) é um antígeno transmembrana encontrado em células, desde o estágio pré-B até a sua diferenciação final em plasmócitos. As funções biológicas desse antígeno não estão bem estabelecidas, mas sabe-se que ele é encontrado em 90% das neoplasias de célula B e que o seu bloqueio tem efeitos variáveis na progressão do ciclo da célula, provocando a morte celular .

No Brasil, foi encontrado apenas um ensaio no Registro Brasileiro de Ensaios Clínicos (ReBEC; http://www.ensaiosclinicos.gov.br/rg/?q=nimotuzumab, acessado em 10/Mai/2018) do nimotuzumabe para a indicação de tratamento de câncer de mama. O anticorpo monoclonal em questão foi registrado pela primeira vez em Cuba e, em uma busca realizada no Registro Público Cubano de Ensaios Clínicos (RPCEC; http://registroclinico.sld.cu/search/node/nimotuzumab, acessado em 10/Mai/2018), foram encontrados estudos do produto biológico em câncer de mama, câncer de esôfago, gliomas, câncer de cabeça e pescoço e câncer de pulmão. Foi encontrado apenas um ensaio para a indicação clínica de câncer colorretal, cuja amostra indicada no desenho do estudo era de apenas vinte pacientes. Os resultados desse último estudo não foram encontrados na base de dados.

Outros estudos têm demonstrado os benefícios do tratamento com uso de ambos os anticorpos ,. Ensaios pré-clínicos demonstraram que o bloqueio de PD-1 concomitantemente ao bloqueio CTLA-1 melhora as respostas antitumorais, se comparado ao bloqueio de uma única via. A combinação de nivolumabe com ipilimumabe resultou em uma taxa de resposta objetiva maior, assim como respostas completas mais frequentes e sobrevida livre de progressão significativamente maior. No entanto, parece que os eventos adversos de graus 3 e 4 foram maiores com a terapia combinada, mas com um perfil de segurança gerenciável ,. Dessa forma, é interessante apontar que, em alguns casos, o bloqueio de antígenos-alvo diferentes no tratamento de um mesmo tipo de tumor aumenta a resposta tumoral e pode ser responsável por resultados melhores que os do uso do agente isolado.

Essa caracterização dos antígenos-alvo para os quais os mABs com registro sanitário ativo para tratamento de câncer são direcionados remete a uma discussão que não é recente no mercado de medicamentos produzidos por síntese química, mas que ainda não é objeto central de discussão no mercado de produtos biológicos: os chamados me-too. Os medicamentos do tipo me-too são muito similares aos líderes de mercado, com pequenas variações em sua estrutura que, na maioria das vezes, não configuram ganhos terapêuticos. Nesse sentido, a estratégia da indústria consiste em manter um mercado lucrativo, investindo em marketing, para promover esses medicamentos "novos", porém não inovadores .

Essa categoria de medicamento não fica restrita aos sintéticos, sendo capaz de alcançar outros produtos de saúde, serviços e até mesmo os produtos biológicos. O desenvolvimento de novos mABs para atuarem no mesmo antígeno-alvo poderia ser uma estratégia possível para aumentar, por exemplo, a competitividade nesse mercado e produzir uma redução nos preços praticados. Contudo, no Quadro 2, é possível observar situações como, por exemplo, o desenvolvimento de três mABs (pertuzumabe, trastuzumabe e trastuzumabe entansina), do mesmo tipo, pela mesma empresa, para atuar no mesmo antígeno e com a mesma indicação clínica. Fojo , nesse sentido, enfatiza a necessidade de se analisar se as novas terapias propostas pelas empresas apresentam inovações terapêuticas radicais.

Os anticorpos quiméricos são aqueles que possuem apenas a sua região variável derivada de anticorpo de camundongo e a fração constante do anticorpo humano. Os anticorpos humanizados, por sua vez, caracterizam-se por possuírem as regiões hipervariáveis do anticorpo de camundongo e o restante da estrutura de anticorpo humano ,. Em termos percentuais, os anticorpos quiméricos são 70% humanos, e os humanizados são entre 85 e 90% humanos .

Dentro desse contexto, quanto ao tipo, neste estudo, foram identificados três mABs quiméricos (brentuxumabe vedotina, cetuximabe e rituximabe), seis humanizados (bevacizumabe, nimotuzumabe, obitunuzumabe, pertuzumabe,trastuzumabe e trastuzumabe entansina) e cinco do tipo humano (ipilimumabe, nivolumabe, ofatumumabe, panitumumabe e ramucirumabe).

É possível destacar que, com exceção dos medicamentos que agem no receptor HER2 (um gene do receptor do fator de crescimento humano super expresso em alguns tipos de câncer), são todos humanizados e existe uma diversidade entre os tipos de anticorpos que atuam nos demais receptores. Em outras palavras, dentre os mABs cujo alvo é o antígeno CD20 ou o EGFR, por exemplo, é possível observar anticorpos resultantes de três tecnologias de produção diferentes - quimérico, humanizado e humano.

O desenvolvimento desses anticorpos totalmente humanos representou um grande avanço e acarretou uma onda de anticorpos aprovados pelas diversas agências reguladoras do mundo, sendo a oncologia hoje uma das principais áreas de utilização dessa classe de produtos. A evolução no processo produtivo, com substituição dos anticorpos murinos pelos quiméricos, humanizados e humanos, permitiu a aplicação terapêutica desses produtos com diminuição das respostas imunes geradas no organismo do paciente. Conforme se aumentou a similaridade do anticorpo terapêutico com os anticorpos humanos, diminuiu-se a imunogenicidade e, portanto, os eventos adversos relacionados a ela ,.

Na análise acerca do mercado brasileiro de mABs para o tratamento de neoplasias malignas no Brasil, este estudo identificou que oito diferentes empresas detêm o registro sanitário dos 14 mABs incluídos no estudo. A Tabela 1 traz os dados das principais empresas farmacêuticas e biotecnológicas do mundo por receita anual de venda no ano de 2015, bem como as estimativas de vendas e participação de mercado dessas empresas para o ano de 2022.

Foi possível observar que a Roche detém o registro de seis mABs, o que representa 43% dos registros sanitários ativos no mercado brasileiro de anticorpos para o tratamento de câncer. Em segundo lugar, com dois anticorpos (15%), destaca-se a Bristol-Myers Squibb. Os outros seis mABs são registrados por seis empresas diferentes.

Em 2010, nove mABs adquiriram o status de blockbuster no mercado global, gerando vendas superiores a um bilhão de dólares. As vendas dos 25 anticorpos ativos registrados em 2010 foram na ordem de 43 bilhões de dólares, sendo 75% por apenas cinco deles: bevacizumabe (Avastin®), rituximabe (Rituxan®), adalimumabe (Humira®), infliximabe (Remicade®) e trastuzumabe (Herceptin®). Três desses cinco anticorpos - bevacizumabe, rituximabe e trastuzumabe - também são os mABs registrados no Brasil há mais tempo para câncer .

É possível notar uma maior concentração de empresas no setor biotecnológico do que no setor farmacêutico tradicional e no que diz respeito à participação no mercado, com a Roche tendo o domínio de 16% do mercado de biológicos no ano de 2015 . É interessante resgatar, nesse sentido, a discussão que se faz sobre oligopólio diferenciado quando se pensa no mercado farmacêutico. Esse termo refere-se ao fato de que existe, sim, uma concentração produtiva de mercado, mas que ocorre segundo nichos e classes terapêuticas ,. A necessidade de produtos específicos para cada tipo de doença e, muitas vezes, a possibilidade de substituição entre produtos praticamente inexistentes evidenciam os mercados altamente concentrados . Sendo assim, comparando as empresas que dominam o mercado de produtos oncológicos com outros mercados farmacêuticos, é possível identificar diferenças.

Os resultados apontaram que o registro sanitário de novos mABs não é necessariamente consequência da descoberta de novos antígenos-alvo. Nesse sentido, este estudo apontou a necessidade de que se pense até que ponto as inovações propostas a esses novos produtos biotecnológicos são, de fato, inovadoras, para que não aconteça no mercado biotecnológico o mesmo que aconteceu com o mercado farmacêutico: o surgimento de um grande número de medicamentos me-too. Apesar do surgimento de novos mABs para um mesmo antígeno-alvo poder representar a possibilidade de um mercado mais competitivo, não é isso que acontece quando esses produtos são desenvolvidos pela mesma empresa. Nesse caso, o grande número de me-too, em vez de representar uma possibilidade de aumento de concorrência, pode apenas significar uma estratégia de marketing da empresa e se configurar como mais um obstáculo ao acesso.

Além disso, identificou-se que quase metade dos registros sanitários ativos de mABs para tratamento de câncer no mercado brasileiro é de domínio da empresa farmacêutica Produtos Roche Químicos e Farmacêuticos S.A. Essa empresa domina outros mercados, mas nem todos os mercados farmacêuticos e biotecnológicos, o que contribui para corroborar a discussão sobre oligopólio diferenciado. A baixa competitividade do mercado contribui para a prática de altos preços, favorecendo o acesso desigual a tratamentos inovadores em oncologia.

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O mercado brasileiro de anticorpos monoclonais utilizados para o tratamento de câncer

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Os mABs, proteínas cujo mecanismo de ação é complexo, são imunoglobulinas derivadas de um mesmo clone de linfócito B, cuja clonagem e propagação se efetuam em linhas de células contínuas . São produzidos para reagir com antígenos específicos de certos tipos de células, tendo maior capacidade de preservar as células saudáveis quando comparados às terapias citotóxicas padrão .

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Artigo: A Review of the Important Role of CYP2D6 in Pharmacogenomics

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Artigo: A Review of the Important Role of CYP2D6 in Pharmacogenomics

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Esse artigo é muito interessante e fala sobre o papel das variantes do CYP2D6, responsável pela metabolização de cerca de 20% dos fármacos. O artigo, não longo para um assunto tão rico e complexo, traz muitas informações interessantes sobre as variações do gene, a sua distribuição nas populações, e o impacto na resposta à diferentes fármacos. #farmacogenômica

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Open Access Editor's Choice Review

Wolfson Centre for Personalised Medicine, University of Liverpool, Liverpool L69 3BX, UK

MC Diagnostics, St Asaph Business Park, Saint Asaph LL17 0LJ, UK

Author to whom correspondence should be addressed.

Received: 26 September 2020 / Revised: 25 October 2020 / Accepted: 28 October 2020 / Published: 30 October 2020

1. Introduction

1.1. Background to Cytochrome P450 Enzymes

The cytochrome P450 (CYP) superfamily is an ancient family of enzymes identified in hundreds of eukaryote and prokaryote species [ 1, 2], and are named thus because they strongly absorb 450 nm wavelength light when reduced and bound by carbon monoxide. CYP standard nomenclature is the prefix, "CYP", followed by a number for the family (proteins sharing more than 40% amino acid sequence identity), a letter for the subfamily (at least 55% identity) and a number for the specific gene; for example, CYP2D6 [ 3]. The human genome encodes 57 putatively functional CYP genes along with 58 pseudogenes [ 4]. Of these 57 functional human CYPs, 12 are implicated in the metabolism of 70-80% of commonly used drugs; specifically, these are: CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2J2, CYP3A4 and CYP3A5 [ 4].

CYPs are hemoproteins and there is extensive diversity of CYP gene sequences [ 5, 6]. However, the three-dimensional (3D) structure of the common CYP fold is highly conserved, being predominantly α-helical (usually 12-13 α-helices) with a small number of β-sheets [ 5, 6, 7]. The structural domains that surround the heme complex form the substrate recognition and access channel [ 3]. CYP enzymes are typically the terminal oxidase enzymes in electron transfer chains. The major electron donor for microsomal CYPs is P450 reductase (POR), which donates the first and often both of the electrons required by a CYP for catalysis [ 8, 9]. The canonical reaction catalysed by CYPs is monooxygenation, although they can also catalyse other reactions including hydroxylation and dealkylation. Human and other mammalian CYP enzymes are membrane-anchored proteins embedded in the phospholipid bilayers of the endoplasmic reticulum or mitochondria [ 5, 10].

1.2. Background to Pharmacogenomics

Interindividual variability in drug response is a growing concern for healthcare systems across the world, since it can blunt drug efficacy and precipitate adverse drug reactions (ADRs) leading to patient harm, poorer health outcomes, and inefficient consumption of limited healthcare resources. It is estimated that for many drugs used across a range of diseases, only 50-75% of patients experience a beneficial response [ 11]. Studies in European populations have demonstrated that 3.5-6.5% of hospitalised patients are admitted because of ADRs, and one or more ADRs can occur in almost 15% of hospital inpatients [ 12, 13, 14]. Additionally, the risk of ADRs increases in patients administered multiple drugs [ 15], contributing to the clinical burden of (potentially inappropriate) polypharmacy. ADRs differ in severity with the majority of adverse events considered mild (e.g., headaches, fatigue, constipation and/or nausea), although the overall number of cases is believed to be underreported [ 16]. Nevertheless, non-severe and non-serious cases still present an avoidable burden to healthcare systems. Notably, a 2015 National Institute for Health and Care Excellence (NICE) statement concluded that 72% of ADRs are potentially avoidable, with the estimated cost of these ADRs in excess of £500 million in the UK alone [ 17]. Therefore, it is important to understand and mitigate drug response variation.

Variation in drug response is, in general, multifactorial with demographic, environmental, clinical, and genomic components. Pharmacogenomics is the study and clinical application of the genetic determinants of drug response. The aim of pharmacogenomics is to guide dose selection, drug selection, and/or prioritise patients for closer monitoring through stratification of patients based on genetic variants in order to improve drug efficacy and/or safety, and this is at the vanguard of the precision medicine initiative [ 18, 19, 20]. Pharmacogenomic studies have evolved from candidate gene investigations to genome-wide association studies (GWAS) and increasingly to sequencing based projects; sample sizes have similarly grown although, in general, remain notably smaller compared to genomic studies of polygenic diseases. Nevertheless, the magnitude of drug-gene associations is often notably larger than disease-gene associations [ 21], presumably reflecting less constrained evolutionary selection pressures. Currently, pharmacogenomic information is contained somewhere within the drug label of 298 drugs approved by the US Food & Drug Administration (FDA) [ 22]. Moreover, to date, the clinical application of gene associations with 123 drugs has been reviewed and, of these, clinical guidelines for just over 80 drugs have been developed that contain clinically actionable pharmacogenomic recommendations [ 23]. The majority of this evidence assessment and guideline writing has been conducted by the Royal Dutch Association for the Advancement of Pharmacy-Pharmacogenetics Working Group (DPWG) [ 24] and the Clinical Pharmacogenetics Implementation Consortium (CPIC) [ 25], although other guideline-writing committees also exist such as the Canadian Pharmacogenomics Network for Drug Safety (CPNDS) [ 26], the Réseau National de Pharmacogénétique (RNPGx) [ 27], and the NHS England Pharmacogenomics working group.

1.3. Background to CYP2D6

CYP2D6 is a particularly important and well-studied member of the CYP superfamily. In the late 1970s, the metabolism of debrisoquine, and separately sparteine, were both shown to be highly variable yet controlled by a single autosomal gene, which we now know to by CYP2D6 [ 28, 29]. The human CYP2D6 gene is relatively short, spanning just ~4.3 Kbps on the long arm of chromosome 22 (22q13.2), is encoded by nine exons, is translated into CYP2D6 protein that localises to the endoplasmic reticulum, and is highly expressed in liver, brain, intestinal tissue and lymphoid cells [ 10, 30]. CYP2D6 has numerous endogenous substrates including tyramine in the brain and lymphocytes [ 31, 32], and 5-hydroxyindoleacetic acid in brain tissue and possibly cerebrospinal fluid [ 33, 34]. Importantly, although CYP2D6 constitutes just 2-4% of total hepatic CYP content [ 35], it is a cardinal drug-metabolising enzyme involved in the metabolism of approximately 20% of commonly used drugs [ 36, 37]. Thus, CYP2D6 can metabolise a wide range of substrates including analgesics (e.g., codeine, tramadol), antidepressants (e.g., paroxetine, tricyclic antidepressants), antihypertensives (e.g., metoprolol, bisoprolol) and the anti-cancer agent, tamoxifen [ 38, 39, 40, 41].

Overall, to date, 72 different drugs have CYP2D6 mentioned within their FDA-approved product label [ 42]. Furthermore, the clinical relevance of CYP2D6 to at least 48 drugs has been reviewed by pharmacogenomic guideline committees and actionable recommendations based on CYP2D6 have been developed for 26 drugs to date [ 23], as summarised in Table 1. It is clear that CYP2D6 is a promiscuous pharmacogene implicated in drug response across a large number of medical specialities ( Figure 1).

The rate of CYP2D6-mediated microsomal metabolism varies at least 60-fold between individuals [ 43]. CYP2D6 is highly polymorphic and its genetic complexity is an important contributor to its functional variation. Therefore, the genetic complexity of CYP2D6 and its pivotal role in the metabolism of multiple drugs makes accurate and effective CYP2D6 genotype-based clinical prescribing a key milestone in any pharmacogenomics implementation effort. Thus, this review will focus on describing CYP2D6 genomic variation, the functional consequences of this variation, laboratory methods to detect and analyse CYP2D6 variants, the clinical impact of CYP2D6 pharmacogenomics, and highlight cutting edge developments in parsing CYP2D6 genotype-to-phenotype translation. This review has been written for an intended audience that includes both non-geneticists and healthcare prescribers as well as those proficient in pharmacogenomics.

2. An Overview of CYP2D6 Variation

Variation in CYP2D6 includes single-nucleotide variants (SNVs), indels, whole-gene deletions, multiplications, tandem arrangements and hybridisations [ 40, 44]; it can also be affected by larger chromosomal deletions or other structural alterations as part of the rare 22q13 deletion syndrome, known as Phelan-McDermid syndrome. Currently, there are 133 CYP2D6 "star" ("*") alleles listed on the PharmVar data repository [ 45], as detailed within a recent and in-depth review of 2D6 nomenclature and 2D6 allele designation by Nofziger et al. [ 46]. In essence, the star allele nomenclature system represents a useful haplotype-based system that is well established and recognised within the pharmacogenomic field [ 46]. Many of the listed variants contribute in part or entirely to altered rates of CYP2D6-associated drug metabolism. The majority of identified CYP2D6 variants are SNVs, which encompass both single-nucleotide polymorphisms (SNPs, defined as SNVs with a minor allele frequency, MAF ≥ 1%) and rarer (MAF < 1%) nucleotide substitutions. Like other genes, CYP2D6 SNVs can be in the non-coding regions (e.g., the promoter or introns) with variable effects on protein expression, or located in the coding regions, leading to synonymous or nonsynonymous (both missense and nonsense) alterations. Small base insertions/deletions (indels) may be of little consequence when occurring in non-coding (e.g., intronic) gene regions, although they could perturb transcription factor binding. However, when indels affect coding DNA and are not a multiple of three, they can change the reading frame and result in frameshift mutations. Importantly, beyond these short forms of variation, the genetic architecture of CYP2D6 differs from that of other CYP pharmacogenes by the extent and complexity of larger structural variation that can occur, as briefly highlighted below. For further information, the reader is directed to the Pharmacogene Variation Consortium (PharmVar) CYP2D6 Structural Variation document [ 47], which provides an excellent up-to-date and detailed overview of CYP2D6 structural variation.

2.1. Pseudogenes

One major complication of analysing CYP2D6 is resolving the issue of the highly similar non-functional pseudogenes, CYP2D7 and CYP2D8, which are located nine and 19 kbp upstream of CYP2D6 and have 94.2% and 89.1% sequence similarity to CYP2D6, respectively [ 36]. All three genes consist of nine exons, and CYP2D6 and CYP2D7 share a common downstream element that is 0.6 kbp in length [ 43, 47]. Moreover, CYP2D6 and CYP2D7 have near-identical repetitive sequences termed REP6 and REP7, respectively, although REP7 is separated by an additional short length of sequence from the common element in CYP2D7, unlike REP6 in CYP2D6 [ 47] (see Figure 2A). This level of similarity, particularly between CYP2D7 and CYP2D6, requires any genotype detection method to be highly specific to CYP2D6 [ 36]. However, further complicating this problem is that many haplotype-defining CYP2D6 SNPs, such as rs35742686 (*3), have identical flanking sequences in CYP2D6 and CYP2D7, and thus present a challenge to distinguish between using probe-based and microarray testing techniques.

2.2. Copy Number Variation

Copy number variation (CNV) is a type of larger structural variation and, in a diploid genome, generally refers to the presence of more or less than two copies of a gene. CNV is common in CYP2D6 and individuals, with one or three CYP2D6 copies occurs at a frequency of 12-23% depending on population ethnicity [ 40]. The significance of this type of variation on the metaboliser phenotype of CYP2D6 depends on the functionality of the duplicated CYP2D6 allele. Indeed, it has been shown in a population of patients from Hong Kong that fewer than 20% of duplicated CYP2D6 alleles were duplications of functional alleles [ 44]. However, an increased copy number of functional CYP2D6 alleles increases the rate of metabolism of associated drugs [ 39], with some studies reporting as many as 13 copies of CYP2D6 in a single individual's genome [ 48]. Thus, an individual with more than two functional copies of CYP2D6 is considered to have ultra-rapid metabolism for CYP2D6 substrate drugs. CYP2D6*1, *2 and *4 are the most common haplotypes in which duplications or multiplications are observed and are denoted as 'CYP2D6*1xN' '*2xN' and '*4xN', respectively [ 40]. Other rarer duplications have been identified, including CYP2D6*6xN, *10xN, *17xN, *36xN, *41xN, *43xN and *45xN [ 49].

CYP2D6*5 represents a whole allele deletion with a corresponding complete loss of function of the allele. Overall, this variant is present in 3-6% of African, European and East Asian populations ( Table 2). However, it is more diverse within sub-populations and so, for example, gradually increases from 1 to 6%, moving from southern to northern European countries, respectively [ 50]. CYP2D6*5 deletions are derived from breakpoints in the highly repetitive REP6 and REP7 sequences [ 38], leaving CYP2D6*5 with a REPdel sequence consisting of fused REP6 and REP7 elements [ 51].

2.3. Hybridisations, Tandem Arrangements and Conversions

Structural hybridisation describes the rearrangement of a gene sequence to form an alternate gene sequence, which often leads to a protein with reduced or no function. Many different hybridisations of CYP2D6 have been observed and typically involve the joining of CYP2D6 and CYP2D7 sequences together to make a recombinant hybrid gene ( Figure 2B) [ 51, 52, 53, 54]. CYP2D6-2D7 and CYP2D7-2D6 are two distinct forms of hybridisation (see below). It is also possible that a sequence from CYP2D7 can be inserted into CYP2D6 at a specific point, which is termed a gene conversion [ 36, 47].

CYP2D6-2D7 hybrids are formed when the 5′ section is from CYP2D6 and the 3′ section is from CYP2D7, forming a hybrid structure in place of wildtype CYP2D6. Examples of this include *36 and *61. Similarly, in CYP2D7-2D6 hybrid genes, the 5′ element of the hybrid is from CYP2D7 and the 3′ part is from CYP2D6; CYP2D7-2D6 arrangements lack CYP2D7 5′ to the recombinant gene and so could originate from the deletion of the intervening sequence [ 53]. Several CYP2D7-2D6 hybrids that conform to this pattern have been identified; although they differ in the exact 2D7-2D6 joining point between the two genes, they are collectively grouped together under the CYP2D6*13 designation [ 47].

Tandem arrangements contain two or more copies of a gene unit on the same chromosome featuring non-identical variation between the gene units. Gene duplications and multiplications are distinguished from tandems by the gene units of duplications/multiplications being the same [ 47]. In most tandems, at least one gene copy is a CYP2D7-2D6 or CYP2D6-2D7 hybrid arrangement. CYP2D6*36 + *10 is the most common tandem arrangement, and is particularly prominent in East Asian populations with an MAF of 34.1% [ 44]. In this tandem arrangement, the 5′ upstream gene unit is usually a 2D6-2D7 hybrid (*36), whilst the 3′ downstream gene unit contains the missense SNP that defines *10 (rs1065852, p.P34S). Evidence suggests that the *36 + *10 tandem is associated with decreased function, reflecting that *36 alone (as a single gene unit) has no function and *10 alone has decreased function [ 36, 55, 56].

2.4. Structural Impact of Star Alleles

X-ray crystallography has revealed that the 3D structural conformation of CYP2D6 differs between ligand-bound and ligand-free forms. The most distinct structural changes observed include the closing of the active site by reorganisation of helix F and Gly-218 [ 57, 58]. The structural changes caused by the non-synonymous, frameshifts and splicing mutations, which define the CYP2D6 star allele, drive the change in function, thus driving the metabolism phenotype. However, several of the most common function effecting point mutations do not occur near amino acids associated near the active site, instead occurring towards the extremities of the molecule, distant form the central heme iron ( Figure 3).

3. CYP2D6 Metaboliser Status

The current categorisation of CYP2D6 metaboliser status is based on activity scoring of known haplotypes [ 46]. Activity scores (AS) serve as a useful tool to translate information regarding the function of individual haplotypes into an overall predicted metaboliser status for a given diplotype, and thus an individual. At present, CYP2D6 categories remain relatively discrete and are broadly grouped into poor metaboliser (PM, AS = 0), intermediate metaboliser (IM, AS = 0.25-1), extensive (normal) metaboliser (EM, AS = 1.25-2.25) and ultra-rapid metaboliser (UM, AS > 2.25) strata [ 60]. This pragmatic approach is useful and is periodically updated as evidence regarding the metaboliser function of individual haplotypes accumulates. CYP2D6 pharmacogenomic guidelines use these metaboliser categories to provide clinicians with drug-specific recommendations with the aim of avoiding doses or drugs expected to be ineffective or harmful in patients that have a particular CYP2D6 metaboliser status.

4. CYP2D6 Star Allele Frequencies

Table 2 shows population frequencies for several CYP2D6 star alleles (that generally represent haplotypes) that are common (MAF ≥ 1%) in at least one major population group and (except *2) affect CYP2D6 function. However, importantly, these crude frequencies do not account for the complexities of CYP2D6 haplotype impact on metabolism. For example, rare variants are not considered. Furthermore, in-depth studies assessing overall frequencies of CYP2D6 metabolism status found that >20% of Ashkenazi Jewish and Europeans populations have non-functional haplotypes, 45% of East Asian Individuals had reduced function haplotypes and >10% Oceania individuals have increased function haplotypes [ 61]. This high haplotype frequency disparity can also be seen in other sub-populations and some haplotypes are only present at high frequency in specific populations. For example, CYP2D6*4 was found to be present in 22% of Jewish individuals [ 61] and CYP2D6*5 was found to be present in 16% of north Indian individuals; however, both CYP2D6*4 and CYP2D6*5 were significantly lower in other populations [ 62]. These population frequencies have also been stratified by AS, which varies depending on the combination of haplotypes and number of duplicates/deletions present. These data showed the high frequency of AS 1.5-2 across most major populations, and AS > 2 in over 10% of Oceanian, Middle Eastern and Ashkenazi Jewish populations [ 61].

5. Detection and Interpretation of CYP2D6 Genotype

Several existing CYP2D6 haplotype detection methods exist, including methods which can detect hybrid arrangements and quantify CNVs. Many of these methods include an initial sequencing step to specifically amplify CYP2D6 prior to genotyping, or as a comparison to other assays. It is important to note that, at present, there is no agreed consensus on which CYP2D6 variants should be always included when interrogating CYP2D6. Therefore, whilst different commercial solutions usually test some major CYP2D6 alleles (*2, *4, *5, *10, *17), different combinations of other CYP2D6 variants are provided by different products [ 65].

Long-range polymerase chain reaction (PCR) or extra-long-range PCR methods are designed to amplify the entire CYP2D6 gene and therefore can detect multiple copies or whole-gene deletions [ 66]. Some studies further developed this approach by directly sequencing the PCR product to ensure high sequence fidelity within exonic regions [ 67]. Pyrosequencing in particular has been established as an inexpensive high-throughput sequencing method in comparison to traditional Sanger sequencing [ 68] and can been used as a sequencing step for CYP2D6 variant detection [ 69]. This sequencing step is then followed by a CYP2D6-specific mutant probe detection assay [ 67]. Combined, these methods are able to accurately determine the presence of a small number of CNVs and has the potential to capture multitudes of other SNPs of interest. However, in its current form, this process is better suited for small-scale research projects, as it consists of multiple PCR steps, and is expensive and labour-intensive.

Taqman methods use bioluminescent tagged probes which can be designed to capture specific sequences with a high degree of precision. qPCR amplification using Taqman probes enables the relative quantification of target sequences, making it ideal for detection of CNVs [ 70]. However, this method is expensive and labour-intensive if testing a wide variety of haplotypes and has limited multiplexing potential.

Many companies offer custom microarrays which can capture SNPs; however, not all are able to determine CNVs and thus have limited use for clinically meaningful CYP2D6 genetic analysis. More specialised products are capable of detecting CYP2D6 CNVs [ 71]. The Amplichip CYP2D6 genechip platform is a microarray hybridisation assay that can detect CYP2D6*2, *3, *4, *5, *6, *9, *10, *35 and *41 and duplicates of these SNPs [ 72]. Similar to Ampligene, CYP2D6 Genochip is a microarray that can detect CYP2D6*3, *4, *6, *7, *8, *9, *10, *11, *17, *29, *41, gene deletion (*5) and gene multiplication (*xN). Comparisons between these platforms have shown a high degree of concordance; however, the Ampligene platform appears able to elucidate CYP2D6 diplotypes more precisely [ 73].

Several algorithms have been developed to infer CYP2D6 haplotype from whole-genome sequencing data [ 74, 75, 76]. Most recently, the Cyrius software algorithm has been shown to be the most accurate with 96.5% concordance between predicted and reported haplotype [ 76]. This approach could prove to be a valuable way to predict an individual's metabolism using existing data as whole-genome sequencing becomes more affordable and more commonly undertaken.

Sequencing and genotyping of the somatic genome is becoming increasingly available in oncology. However, there are challenges to using (stored) tumour tissue to determine an individual's (germline) pharmacogenomic profile. Of note, cancer mutagenesis can potentially alter the genotype of pharmacogenes within the somatic genome, leading to misclassification of the predicted germline genotype. Furthermore, in breast cancer, the region on chromosome 22 that contains CYP2D6 is commonly deleted [ 77]. Lastly, the process of formalin fixation damages somatic DNA, although repair processes have been developed [ 78].

6. Factors Impacting CYP2D6 Function beyond CYP2D6 Genetics

Adding to the complexity of CYP2D6 metabolism is the effect of non-genetic factors that contribute to metaboliser phenotype. As it stands, existing haplotypes alone may not reflect the full underlying genetic complexity of drug-metabolising CYPs due to, for example, rare variation, nor do they consider non-genetic factors. Epigenetic regulation, drug-drug interactions and some foodstuffs influence CYP2D6 activity. Of note, drugs that inhibit CYP2D6 function can lead to an individual having a less functionally active metaboliser phenotype than would be predicted by their genotype, a process termed 'phenoconversion' [ 79, 80]. Examples of strong CYP2D6 inhibitors that increase the area under the concentration-time curve (AUC) of sensitive CYP2D6 substrates (e.g., dextromethorphan, nortriptyline, eliglustat) by ≥5-fold include fluoxetine, paroxetine and bupropion [ 81]. In addition, a range of food products and associated chemicals have also been identified as CYP2D6 inhibitors, including sesamin [ 82], curcumin and the botanical herb, goldenseal [ 83]. CYP2D6 phenotyping can evaluate phenoconversion, for example in dedicated drug-drug interaction studies incorporating a CYP2D6 probe drug (e.g., dextromethorphan) or other substrate of interest. Alternatively, endogenous metabolites have been suggested as alternate CYP2D6 probes, such as urinary M1 (m/z 444.3102) identified through global metabolomics [ 84], although further validation of endogenous metabolites should be sought. Several proposed methods have been suggested to counteract the issue of phenoconversion by CYP2D6 inhibition including prioritising phenotyping over genotyping where possible, utilising metabolic probes or even using endogenous compounds to determine phenotype. One suggested improvement is simply to evolve the nomenclature to incorporate phenoconversions, therefore separating this from 'classic' metabolism statuses (e.g., pUM instead of UM) [ 85]. This approach would theoretically reduce communication errors and provide additional information when capturing phenoconversion data.

Interestingly, there are no recognised drug inducers of CYP2D6, and so the UM phenotype appears predominantly genetic in origin. It appears that canonical xenobiotic-sensing receptors that upregulate expression of CYP3A4 and other CYPs, including pregnane X receptor (PXR) and constitutive androstane receptor (CAR), have little effect on CYP2D6 [ 86]. Nevertheless, the expression of CYP2D6 transcripts is controlled by different transcriptional regulators and growing evidence suggests they contribute to part of the observed CYP2D6 variability [ 43]. For example, the transcription factor, hepatocyte nuclear factor 4α (HNF4α), is a global regulator of genes involved in liver-specific functions, and it has been shown in a systematic study of over 450 human livers that the mRNA levels of HNF4α correlate with the microsomal activity of multiple drug-metabolising CYPs, including CYP2D6 [ 87]. Moreover, a rich pharmacokinetic study that administered a single dose of tolterodine (a CYP2D6 substrate) to 30 healthy Korean individuals determined that a genetic variant within HNF4A, G60D, was significantly associated with tolterodine exposure independent of CYP2D6 genotype, and accounted for approximately a quarter of the variation explained by CYP2D6 [ 88]. It has also been observed that pregnancy induces CYP2D6 activity [ 43]. Although mechanistic understanding of this is incomplete, mouse models (e.g., CYP2D6-humanised mice) and cell lines (e.g., HepG2 cells) have led to the identification of the novel transcription factors, small heterodimer partner (SHP) and Krüppel-like factor 9 (KLF9), that appear to act as a corepressor and coactivator of HNF4α-mediated transactivation of the CYP2D6 promoter, respectively [ 43]. Thus, in pregnancy, it appears that expression of the corepressor SHP is reduced, whilst levels of the coactivator KLF9 are increased, plausibly leading to CYP2D6 induction [ 89, 90].

7. CYP2D6 Clinical Impact

Clinical Guidelines and Pharmacogenomics Implementation

The clinical guidelines developed by both CPIC and DPWG for CYP2D6-substrate drugs have overall a high degree of similarity in their determination of CYP2D6 metabolism status and therapeutic recommendations [ 91]. Moreover, recent efforts to address inconsistencies between these guidelines have further harmonised CYP2D6 metabolism status [ 39, 60, 92]. Nevertheless, the advice between the guideline writing groups differs for a few drugs, including fluvoxamine and paroxetine ( Table 1). It is also apparent that few drugs have had guidelines developed for them from all of the aforementioned pharmacogenomic guideline-writing committees, reflecting the international collaborative approach of the relatively small pharmacogenomics research field, the effort and expertise required to develop clinical guidance, and the likely influence of different patterns of prescribing between countries and regions.

As stated earlier, actionable pharmacogenomic guidance has been developed for 26 drugs involving CYP2D6 to date. The majority of these drugs are established drugs that already have a license. An exception is the glucosylceramide synthase inhibitor, eliglustat, which is a new drug indicated in Gaucher disease type 1, and was licensed with a requirement for companion CYP2D6 testing, as stated in its product label [ 93]. The evidence underpinning CYP2D6 clinical guidelines is generally based on the totality of published, predominantly observational, studies, due to an absence of large randomized control trials. Despite the limitation of this lack of gold-standard evidence, the amalgamation of congruent pharmacokinetic studies, clinical observational studies and case reports within clinical guidance provides a pragmatic approach to sensibly interpret and facilitate the use of the existing knowledge base. It can be contended that this evidence base is equivalent to the evidence underpinning dose/drug modifications based on renal or liver function biochemical testing, which is routinely carried out for many drugs in clinical practice. Overall, the question over the evidential threshold needed for dose/drug optimisation strategies has yet to be fully addressed; however intuitively, it seems reasonable to suggest that, given limited resources for research, it should not always require the same level of evidence as required for tests that carry greater clinical consequences (e.g., tests that lead to a new diagnosis, or, for example, high-risk BRCA mutations that can lead to prophylactic surgery).

Nevertheless, to inform the evidence base for pharmacogenomics implementation, one initiative being conducted is the PREPARE study. PREPARE is a large pan-European block randomised prospective pharmacogenomics intervention study, coordinated by the Ubiquitous Pharmacogenomics consortium, that has recruited ~7000 patients. These patients started one of 42 drugs, for which a DPWG guideline is available, and have been followed up for adverse events for 12 weeks [ 19]. In the control arm, patients were dosed according to standard care. In the intervention arm, patients have been genotyped for 44 variants in 12 genes, including CYP2D6, and DPWG therapeutic recommendations have been made available based on these genotype results to the patient's healthcare team within one week of starting the drug. It is expected that the primary results of PREPARE will be available in 2021 and, whilst PREPARE is not powered to answer whether individual drug-gene pairs should be implemented, it will address whether or not an overarching pharmacogenomics approach is clinically and/or cost-effective [ 19].

Recommendations in CYP2D6 guidelines include: starting with the usual dose of the drug (e.g., in EMs), altering its dose (e.g., in IMs), selecting an alternative drug (e.g., in PM/UMs), or considering increased patient monitoring and therapeutic drug monitoring if available (e.g., in PMs). In a few guidelines (e.g., atomoxetine, tamoxifen), the IM category is further subdivided and specific recommendations are provided according to the presence/absence of the CYP2D6*10 allele (AS 0.25). This metaboliser status classification system has been similarly used in the pharmacogenomic guidelines for other important CYP pharmacogenes (e.g., CYP2B6, CYP2C9, CYP2C19, CYP3A5), albeit usually without activity scoring because of the lower complexity of genetic variation compared to CYP2D6. However, these other CYP pharmacogenes can have different gene-specific considerations, such as an additional rapid metaboliser (RM) category for CYP2C19, and no UM group for CYP3A5.

A nationwide study in the Netherlands of over 45 commonly prescribed drugs paired with genotype data found that, overall, the implementation of pharmacogenomics using DPWG guidelines could lead to 5.4% of prescriptions being altered (e.g., dose adjustments or selection of alternative drugs) [ 94]. For drugs linked to CYP2D6, the proportion of patients with an actionable recommendation varied by drug according to which metaboliser statuses were deemed actionable. Thus, for example, only 5% of aripiprazole prescriptions were associated with a recommendation (reduced maximum dose) because only the PM category is considered actionable in DPWG guidance for aripiprazole. However, DPWG guidance recommends optional (for IM or PM patients) or definite (for UM patients) prescription alterations for 47% of tramadol prescriptions. Several other drugs, such as flecainide, venlafaxine and imipramine, were similarly recommended a drug or dosage change based on CYP2D6 genotype in >45% of cases [ 94]. The following subsections highlight CYP2D6 pharmacogenomics in relation to two case-studies: codeine and tamoxifen.

8. CYP2D6-Drug Case Studies

8.1. Codeine

Codeine is an opiate prodrug used primarily as an analgesic agent and to treat diarrhoea and cough. However, codeine can have a range of adverse effects from relatively mild nausea, constipation and headaches, through to drowsiness and serious respiratory depression. Metabolism of codeine into active morphine is dependent on CYP2D6, and so is strongly influenced by CYP2D6 genotype ( Figure 4). Codeine displays a reduced binding potential to mu opioid receptors compared to morphine, resulting in milder analgesic effects. Codeine is also considered to be the safer of the two compounds [ 95, 96]. If an individual is a CYP2D6 PM, there is an increased likelihood of an insufficient analgesic effect [ 97]. Conversely, several importantly case reports have identified severe respiratory depression in UM children following tonsillectomies [ 97, 98, 99]. Mothers who are CYP2D6 UMs also appear to have increased morphine present in their breast milk, and this has been associated with severe adverse events in breastfed infants [ 100].

8.2. Tamoxifen

Tamoxifen is a selective oestrogen receptor modulator (SERM) frequently used to reduce the incidence of breast cancer recurrence in pre- and perimenopausal women with oestrogen receptor-positive breast cancer. Although generally well tolerated, it can cause hot flushes, fatigue and nausea amongst other adverse effects. Tamoxifen metabolism is extensive and complex ( Figure 5). Nevertheless, an important secondary metabolite, endoxifen, has almost 100-fold greater anti-oestrogenic potency than parent tamoxifen [ 101]. The major route of endoxifen formation is demethylation via CYP3A4/5 followed by oxidation by CYP2D6 [ 101]. CYP2D6 IM/PMs have been associated with reduced endoxifen plasma concentration [ 102], although the evidence relating CYP2D6 to clinical outcomes indicative of reduced tamoxifen efficacy, such as breast cancer recurrence and mortality, are inconsistent [ 101]. Whilst an association has been shown in some studies [ 103, 104], two large studies dispute an effect [ 104, 105]. Notably, tumour tissue was used for genotyping in both these studies which, as mentioned previously, is a major limitation and their findings may not match the genotype of somatic tissue for the same patients. Furthermore, a recent review suggested that a link between CYP2D6 genotype and tamoxifen adherence was uncovered in these large studies [ 106] and other studies linked a specific CYP2D6 haplotype to outcome in tamoxifen-treated patients [ 107]. Accordingly, clinical guidance for tamoxifen-CYP2D6 has been developed by CPIC and DPWG as well as other societies, which generally recommends alternative treatment, such as an aromatase inhibitor, in CYP2D6 IMs and PMs [ 80, 108].

Other common CYP2D6-mediated drugs such as amitriptyline have also been found to have strong links between CYP2D6 status and increased risk of ADRs [ 110]. Overall, the impact of CYP2D6 genotypes will vary across medical specialities depending on the prevalence of drug prescriptions, which metaboliser phenotypes are associated with altered response for a given drug, and the frequency and severity of a drug's adverse events.

9. Novel Approaches to CYP2D6 Phenotyping

Many CYP2D6 variants, including rare variants and complex combinations of haplotypes, have been identified but not assigned a metabolic function. One in vitro state-of-the-art approach to comprehensively determine the empirical functionality of missense variants is saturation mutagenesis with massively parallel functional assays. In this approach, a mutagenesis library of missense variants is constructed that represent all possible amino acid substitutions within a protein and their in vitro functionality is determined. This high-throughput functional screening approach has been successfully applied to NUDT15 and could be conceivably applied to CYP2D6 [ 111]. Analysis of large datasets is another approach to assign functional effects to these undetermined haplotypes, and is being increasingly carried out to interrogate CYP2D6 [ 112, 113]. One example is the use of sequence data and phenotypic data from >450,000 UK biobank participants [ 112]. Analysis of these data has been used to elucidate haplotypes, but it was unable to capture structural variations. Technologies such as Nanopore utilise long read sequencing, which is able to sequence, identify and capture structural variants in CYP2D6 [ 114].

In recent years, numerous promising approaches have been employed to predict CYP2D6 function, utilising machine learning and deep learning. One interesting example leveraged the observation that CYP2D6 is amongst the most highly expressed CYPs in the brain and so used machine learning to identify imaging patterns within brain perfusion images from functional magnetic resonance imaging (fMRI) associated with CYP2D6 metaboliser groups. This technique was able to detect UM individuals with sensitivity and specificity values of 85-87%, and PM individuals with sensitivity and specificity values of 71-79% [ 115]. Another recent study utilised a deep learning approach to predict the function of CYP2D6 genotypes, including those with rare variants, and then derive a subsequent classification model that predicts whether a CYP2D6 haplotype has a normal or reduced function, and was shown to have a high degree of accuracy [ 116]. Lastly, a neural network model was recently developed and trained on long-read CYP2D6 sequencing data in conjunction with information on the rate of CYP2D6-mediated tamoxifen metabolism from 561 patients with breast cancer. This model linked CYP2D6 variation to the tamoxifen metabolic ratio on a continuous scale, rather than categorising it into the conventional discrete metaboliser phenotype groups. Importantly, it could account for 79% of observed interindividual variation in CYP2D6 activity, compared to 54% with the conventional approach. Furthermore, this model could assign enzyme activity to haplotypes containing uncharacterised combinations of variants, and was validated in independent cohorts. Thus, this approach highlights the potential of combining fully phased gene sequence data with machine learning approaches and continuous scale readout to improve pharmacogenotype-phenotype translation [ 117].

10. Veterinary Pharmacogenomics and CYP2D6 Orthologues

Beyond human pharmacogenomics, interindividual variability in drug response in veterinary practice is also being increasingly explored. However, the scale and implementation of veterinary pharmacogenomics remains limited to date. The primary example of veterinary pharmacogenomics is the identification of an ABCB1 (also known as MDR1 and encodes P-glycoprotein) allele that reduces the function of P-gp and has been associated with severe ADRs following administration of the anti-parasite drug, ivermectin, in homozygous individuals [ 118, 119]. This variant is very common in specific canine breeds (e.g., collies and English shepherd dogs) due to selective breeding to historically desired traits, and highlights the requirement for veterinary pharmacogenomic research to go beyond broad species genetics and to target genetics at breed [ 118, 120] and eventually individual level.

To date, the role of CYP2D6 orthologues in veterinary pharmacogenomics has been poorly elucidated. However, a few examples of CYP2D6 orthologue genotypes influencing drug metabolism have been studied. Canine and equine orthologues of human CYP2D6 are CYP2D15 and CYP2D50, respectively [ 118, 121, 122]. Four haplotypes have been identified in canine CYP2D15 (*1, *2, V1 and WT2), all of which have been shown to metabolise celecoxib at different rates in beagles and, additionally, the rate of metabolism of bufuralol was shown to be reduced in the WT2 haplotype [ 121]. CYP2D15 also has a role in the metabolism of desipramine, dextromethorphan and imipramine [ 123]. Moreover, the equine orthologue, CYP2D50, has been found to harbour SNPs and deletions associated with varying rates of tramadol metabolism, allowing the categorisation of horses into CYP2D50 PMs and EMs, whereas one horse displayed UM status [ 122].

11. Conclusions

CYP2D6 is a very important pharmacogene with dozens of common haplotypes. These haplotypes can significantly influence the metabolism and, thus, systemic exposure of CYP2D6 substrates, leading to variable drug response. As a result, clinical pharmacogenomic guidelines have been developed for at least 48 drugs, which collectively span a wide range of therapeutic indications. Moreover, as approximately 20% of commonly used drugs are metabolised by CYP2D6, the ramifications of variable CYP2D6 activity on drug response is likely to be notable in clinical practice. Thus, incorporating CYP2D6 metaboliser status into routine care is expected to reduce ADRs, save healthcare system resources and improve the efficiency of healthcare sectors. However, there is not yet consensus on which CYP2D6 variants should be routinely tested for clinical use. Moreover, a fast turnaround, cost-effective, non-labour intensive, accurate and reliable method for analysing CYP2D6 with the potential for rapid upscaling is required for effective implementation of CYP2D6 pharmacogenomics in the clinic. However, CYP2D6 presents a number of technical challenges to mass testing in a healthcare setting. In particular, structural variation in CYP2D6 can be challenging to identify and characterise, complicates the design of CYP2D6-specific amplification and detection methods, and can even mask potentially actionable diplotypes. Nevertheless, several technologies and solutions exist that can identify CYP2D6 structural variants, although they are, on the whole, relatively expensive, labour-intensive and/or time-consuming for mass testing. The continued efforts to develop new pharmacogenomics guidelines for different drugs will further aid adoption of CYP2D6 testing in healthcare settings. Finally, novel machine learning approaches that can comprehensively parse CYP2D6 genotype-phenotype relationships hold significant promise for application to whole genome sequencing initiatives. However, there remains much to do to translate current understanding of CYP2D6 into tangible benefit for patients in the clinic.

Author Contributions

All authors listed have contributed significantly to the knowledge, research and structuring of this review. Literature review and compiling of data was conducted by C.T., R.M.T., V.Y. and M.P.; Images and tables were created by C.T., I.C. and P.M.; Biotechnology and novel CYP2D6 approaches section was written by I.C. and P.M. All authors have read and agreed to the published version of the manuscript.

Funding

This review was written as part of a KTP project funded by UKRI through Innovate UK, the Welsh Government and MC Diagnostics. C. Taylor was funded by the Innovate UK Knowledge Transfer Partnership. R. M. Turner was supported by a Postdoctoral Research Fellowship from Health Education England Genomics Education Programme (HEE GEP). The views expressed in this publication are those of the authors and not necessarily those of HEE GEP.

Conflicts of Interest

Christopher Taylor, Ian Crosby and Peter Maguire work with MC Diagnostics which operates as a commercial genetic testing kit manufacturer. The remaining authors have not conflict of interest to declare.

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Figure 1. Venn Diagram showing recognised (non-HLA) pharmacogenes according to their association with drugs used in different therapeutic areas. CYP2D6 overlaps with four distinct therapeutic areas. BCHE: Butyrylcholinesterase. CFTR: Cystic fibrosis transmembrane conductance regulator. CYP2B6, CYP2C9, CYP2C19, CYP3A5, CYP4F2: Members of cytochrome P450 superfamily. DPYD: Dihydropyrimidine dehydrogenase. F5: Factor 5. G6PD: Glucose-6-phosphate dehydrogenase. IFNL3: Interferon lambda 3. ITPA: Inosine triphosphate pyrophosphohydrolase. NAT2: N-Acetyltransferase 2. NUDT15: Nudix hydrolase 15. POLG: DNA polymerase subunit γ. RARG: Retinoic acid receptor γ. SLCO1B1: Solute carrier organic anion transporter family member 1B1. SLC28A3: Solute carrier family 28 member 3. TPMT: Thiopurine S-methyltransferase. UGT1A1: UDP-glucuronosyltransferases. VKORC1: Vitamin K epoxide reductase complex.

Figure 2. Summary of main CYP2D6 structural variant types. Adapted from PharmVar CYP2D6 Structural Variation document [ 47]. ( A) shows the wildtype layout of CYP2D6, CYP2D7 and CYP2D8. ( B) shows examples of structural variants involving CYP2D6. For simplicity, REP6, REP7 and downstream elements have been omitted in ( B).

Figure 3. The 3D structure of CYP2D6 from different angles, annotated with the locations of notable star allele-defining variants (neon green). Images ( A- C) show CYP2D6 from different angles. The images on the left and right show the molecular surface of CYP2D6 and ribbon model of CYP2D6, respectively. The central heme group is highlighted in the ribbon models. Molecular structures were generated and annotated using Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank (PDB) software [ 59].

Figure 4. This figure illustrates the CYP2D6-mediated conversion of codeine to morphine. This pathway results in the metabolism of 0-15% of codeine. Other metabolites codeine-6-glucuronide and norcodeine are metabolized by UGT2B4 and UGT2B7, and CYP3A4, respectively, accounting for remaining codeine metabolism. [ 96]. Secondary metabolites such as morphine-6-glucuronide are not shown for simplicity.

Figure 5. This figure provides a simplified overview focusing on the role of CYP2D6 in the formation of endoxifen. Over 90% of tamoxifen metabolism is CYP3A-mediated N-demethylation to the primary metabolite, N-desmethyltamoxifen, which can be oxidized further by CYP2D6 to endoxifen. Approximately 7% of tamoxifen metabolism is CYP2D6-mediated hydroxylation to 4-hydroxytamoxifen. There is high interindividual variation in endoxifen exposure, which is a significantly more potent anti-oestrogen compared to parent tamoxifen [ 101, 109].

Table 1. Available CYP2D6-Drug Clinical Guidelines.

Drug

Drug Class

Guideline Committee Recommendations

PharmGKB Evidence Level

CPIC

DPWG

Other

Table 2. Selection of common CYP2D6 variant frequencies in major population groups.

CYP2D6 Allele

Frequency

Predicted Function

AFR

EUR

EAS

SAS

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A Review of the Important Role of CYP2D6 in Pharmacogenomics

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Cytochrome P450 2D6 (CYP2D6) is a critical pharmacogene involved in the metabolism of ~20% of commonly used drugs across a broad spectrum of medical disciplines including psychiatry, pain management, oncology and cardiology. Nevertheless, CYP2D6 is highly polymorphic with single-nucleotide polymorphisms, small insertions/deletions and larger structural variants including multiplications, deletions, tandem arrangements, and hybridisations with non-functional CYP2D7 pseudogenes.

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Esse artigo é muito interessante e fala sobre o papel dos produtos naturais na descoberta de novos fármacos com ênfase no cenário brasileiro. O artigo trás várias informações interessantes, como por exemplo sobre as diversas origens dos produtos naturais, o caso do medicamento criado a partir do veneno de jararaca e uma discussão interessante sobre as políticas brasileiras relacionadas ao tema. #drugdiscovery

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Utilização de 🤬 genéticos para individualizar a prescrição de medicamentos #Farmacogenomica

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Utilização de 🤬 genéticos para individualizar a prescrição de medicamentos #Farmacogenomica

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Uma matéria da Veja Saúde que contem algumas informações gerais acerca da farmacogenomia na prescrição individual de medicamentos. Por exemplo, a utilização da farmacogenomica para prescrever medicamentos para tratar a depressão e outras doenças mentais, evitando fortes efeitos colaterais.

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A farmacogenética, ciência que estuda a interação de cada indivíduo com medicamentos, já começa a virar realidade nos consultórios. A técnica utiliza testes de DNA para verificar como um remédio é metabolizado por cada organismo. No entanto, ela ainda precisa ser vista com cautela.

Qualquer tipo de tratamento poderia ser orientado por essa prática, mas é na psiquiatria que ela tem entrado com mais força. A ideia é reduzir o número de tentativas frustradas de medicamentos no combate à depressão e outras doenças mentais, além de evitar efeitos colaterais graves.

"É possível individualizar a prescrição de um remédio conhecendo o fenótipo de cada pessoa", conta o médico geneticista Chad Bousman, professor da Universidade de Calgary, no Canadá. Ele apresentou estudos sobre o tema durante o Genomic Summit 2021, evento promovido pela Dasa, em agosto deste ano.

A análise é feita a partir do princípio de que existem quatro padrões genéticos. São os que metabolizam remédios de forma ultrarrápida, os normais, os intermediários e os lentos. "Com esse dado em mãos, podemos estabelecer não só o tipo de medicamento ideal, mas também a dose que cada um deve receber", explica Bousman.

Os metabolizadores mais ágeis podem precisar de doses maiores, por exemplo, porque o efeito é muito curto. Já nos mais lentos, o fármaco pode demorar demais a agir no organismo, causando mais efeitos adversos. Toda essa balança precisa ser avaliada por um médico capacitado a entender os resultados desses exames.
+ LEIA TAMBÉM: Testes genéticos são capazes de antever futuros problemas no coração
Testes feitos pelo projeto Psychiatric Pharmacogenetics Labs, da Universidade de Calgary, apontaram que nem todos os laboratórios providenciam os dados necessários. "Um mesmo grupo fez exames em quatro endereços diferentes, e os laudos tinham menos de 60% de concordância entre eles", alerta o professor.

Um dos problemas é que os laboratórios não descrevem os resultados de forma suficientemente detalhada. "Muitos tendem a dar indicações prontas de medicamentos a partir de uma análise de algoritmos que não é explicada. O ideal é que a decisão e a avaliação desses dados sejam feitas no consultório a partir das informações coletadas. O médico precisa saber como se chegou à tal recomendação", ensina Bousman.

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Há ainda a questão de cada laboratório possuir uma metologia diferente, segundo o psiquiatra Luiz Dieckmann, coordenador do Instituto Brasileiro de Farmacologia Prática (BIPP).

"É essencial saber quais genes serão testados. Não há o melhor ou pior, mas cada um tem a sua função. Preciso de um lugar que faça a escolha e o processamento correto desses genes e ainda que tenha um bom corpo técnico para avaliar os resultados e entregá-los de forma clara ao médico e ao paciente", descreve Dieckmann.

Momento certo

Entende-se ainda que um teste genético não deve ser solicitado logo na primeira consulta. Bousman avalia que as experiências mais bem-sucedidas ocorrem a partir de um tempo com o paciente, e quando há dificuldade real de se encontrar um tratamento eficaz.

"Temos o exemplo de uma pessoa internada que tomou dois tipos de remédio e também fez uso de eletrochoque. Ela recebeu alta, mas voltou a ter crises. Ao fazer os testes, descobriu-se um outro fármaco que poderia se adequar melhor ao seu organismo e, depois disso, ela ficou estável", exemplifica Bousman.
+ LEIA TAMBÉM: O aconselhamento genético a serviço de uma medicina mais preventiva
Dieckmann concorda com esse tipo de abordagem. "A farmacogenética tem crescido em relevância. Existe um número cada vez maior de laboratórios que fazem esse tipo de exame de forma mais barata, mas ainda há limitações. A técnica deve ser vista apenas como uma ferramenta auxiliar ao médico ", define o psiquiatra paulistano.

Antes de partir para a avaliação do DNA, o mais importante ainda é saber o histórico do paciente, seus problemas de saúde e outros detalhes. Vale lembrar que o tratamento psiquiátrico envolve outras medidas além de remédios, como um programa de atividades físicas, mudanças de rotina e melhoras na alimentação.

"Vejo a farmacogenética não como uma ferramenta para escolher o melhor medicamento, mas para se ter uma ideia de quais são as piores escolhas. Ela ajuda o médico a excluir alternativas no lugar de escolhê-las, principalmente quando a preocupação é evitar que o indivíduo enfrente efeitos colaterais graves", defende Dieckmann.

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Teste genético já é usado para individualizar a escolha de remédios

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A farmacogenética, ciência que estuda a interação de cada indivíduo com medicamentos, já começa a virar realidade nos consultórios. A técnica utiliza testes de DNA para verificar como um remédio é metabolizado por cada organismo. No entanto, ela ainda precisa ser vista com cautela.

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Machine Learning no reaproveitamento de medicamentos #drugdiscovery

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Machine Learning no reaproveitamento de medicamentos #drugdiscovery

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O estudo apresenta estratégias e métodos de utilização de machine learning para acelerar o processo de reaproveitamento de medicamentos, assim tirando proveito de medicamentos já existentes ou combinações de medicamentos que podem ser explorados em uma situação não esperada.
Os autores propõe o Machine Learning no contexto de drug discovery para acelerar o processo pré-clínico de projetar novos medicamentos.

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Abstract

The coronavirus disease (COVID-19) has led to an rush to repurpose existing drugs, although the underlying evidence base is of variable quality. Drug repurposing is a technique by taking advantage of existing known drugs or drug combinations to be explored in an unexpected medical scenario. Drug repurposing, hence, plays a vital role in accelerating the pre-clinical process of designing novel drugs by saving time and cost compared to the traditional de novo drug discovery processes. Since drug repurposing depends on massive observed data from existing drugs and diseases, the tremendous growth of publicly available large-scale machine learning methods supplies the state-of-the-art application of data science to signaling disease, medicine, therapeutics, and identifying targets with the least error. In this article, we introduce guidelines on strategies and options of utilizing machine learning approaches for accelerating drug repurposing. We discuss how to employ machine learning methods in studying precision medicine, and as an instance, how machine learning approaches can accelerate COVID-19 drug repurposing by developing Chinese traditional medicine therapy. This article provides a strong reasonableness for employing machine learning methods for drug repurposing, including during fighting for COVID-19 pandemic.

Introduction

As of January 27, the aggregate number of patients infected with SARS-CoV-2 in the world has exceeded 100 million, and the total number of deaths has reached 2 million.1 There are still 30 million confirmed patients but without receiving specific drugs for treatment. There are two main strategies to find effective treatment drugs for SARS-CoV-2 quickly and effectively. One is the de novo drug design, and the other is the drug repurposing. In which, de novo drug design is the process of signaling new drugs or drug combinations with starting from studying the structure of the receptor protein. Drug repurposing is the process of signaling new effects of drugs or drug combinations based on existing drugs. The details of employing machine learning to assisting the drug discovery and drug repurposing are shown in the following sections, as well as the details describing the progress of discovering therapeutic drug combinations for fighting against COVID-19.

De Novo Drug Design

The current development of de novo drug discovery faces grand challenges, such as long research and development cycles, high cost, and limited experimental success rate. In recent years, the timeliness of drug research and development in the pharmaceutical industry is delaying yearly. However, employing machine learning methods to mining the properties and activities of compounds can be saving the time and costs in an efficient way. The characteristics of drug compounds can be represented by the molecular fingerprints of compounds. The molecular fingerprints include static fingerprints and dynamically generated fingerprints, which can be automatically inferred in the training process by employing machine learning approaches. Specifically, representation learning employs neural network-based approaches to training the embedding of compound features directly.

Lusci et al. [ 1] employed UG-RNN ( update gate recurrent neural network) model to train the vector of the same growth degree with molecular structure. UG-RNN model conveyed the vector of molecular structure to the fully connected neural network. Duvenaud et al. [ 2] trained molecular structure into molecular fingerprints via the GCN ( graph convolution network) model. An algorithm that is mostly used for generating new compounds is variational autoencoders (VAE) [ 3], through which the compounds' feature space can be mapped to a latent space using the encoder, and decoded into a representation of the characteristics of the original compounds through a decoder.

The strategy of combining VAE and GAN ( generative adversarial network) gained rising attention in studying generating the new compounds. Comparing to VAE, RNN ( Recurrent neural network) is another achievable way to design compounds. The model of RNN benefits in better to learn the probability distribution of feature space. Jin et al. proposed the model of GCPN [ 4] to construct the molecular graph structure by employing graph convolutional neural network along with the reinforcement learning framework. In addition, GCPN integrated GAN to minimize the bias between the generated distribution and the original distribution. GraphAF [ 5] is a compound generation model that combines the auto-regressive model with flow-based generation. The experimental results showed that GraphAF can generate 68% of chemically valid molecules without any priori chemical knowledge. Moflow model [ 6] is a flow-based model, which can generate molecule graphs in a certain validity guarantee by linking two probability distributions of the adjacency matrix. Jin et al. [ 7] proposed a generative model and borrowed the molecular pair approach to generate set of molecular rationales (molecular substructures). And a neural network-based approach was employed to combine molecular rationales to design the molecule that simultaneously conform to multiple objectives. Bung et al. [ 8] proposed a generative model as the pre-training model to learn the distribution of physical and chemical characteristics of the compound. And the model can be used to signal and identify SARS-CoV-2 3CLpro chemical frameworks. Zhavoronkov et al. [ 9] employed deep learning-based methods consisting of auto e ncoders (AE), GAN, and reinforcement learning to identifying small molecules that can inhibit SARS-CoV-2 3CL protein.

Computational method-assisted drug design is mainly by employing approaches of molecular docking and network pharmacology. To date, there have a considerable volume of works focused on developing methods of network pharmacology and molecular docking based on traditional Chinese medicine (TCM) to fight against COVID-19 [ 10, 11]. The results indicate that TCM compounds can play an indirect therapeutic effect by directly acting on the new coronavirus or by anti-inflammatory and immune regulation. Ren et al. [ 12] employed data-driven approaches to obtain TCM prescriptions as the potential treatment for pestilence from analyzing classical prescriptions. In this study, they targeted Mpro (3CL hydrolase) and ACE2 (angiotensin-converting enzyme 2) as the vital docking ingredients. And they also analyzed that Gancao (Licorice), HuangQin (Scutellaria), Dahuang (rhubarb), and Chaihu (Bupleurum) contain more potential target treating compounds. Yan et al. [ 13] employed the network pharmacology and molecular docking technology to explored the potential targets, signal pathways, and biological functions of Lianhua treating for COVID-19. And this research is based on combined six mostly used medicine databases.

Drug Repurposing

The effect of employing the strategy of de novo on drug discovering is significant enrichment as mentioned above, though the cost and timeliness of drug design is usually unaffordable. By contrast, drugs with known mechanism of action and pharmacokinetics can be considered as the priori knowledge of specific domain. When discovered the potential effects of the known drug, which is more effective and safe to be used and without having to start from scratch. In such case, the time and economic cost are much smaller of developing "old drugs for a new use". Drug repurposing is a plausible strategy and highly promising technique that has attracted growing attention from governments and pharmaceutical companies for its outstanding performance in saving time and cost. AI technology assisted drug relocation further on reducing time and economic costs. The workflow of the drug repurposing is described in Fig. 1.

The workflow of computational drug repurposing studies

Drug repurposing can benefit from new computational methods in detecting relationships among various types of biological entities such as genes, portions, diseases, and drugs. This study has the advantage in identifying alternative therapeutic indications for existing drugs.

Since the outbreak of the COVID-19 epidemic, drug repurposing has become the most used methods to signaling therapeutic drugs or potential drug combinations due to the long cycle of de novo drug design. Several drugs, such as chloroquine, phosphoate, and radecivir, have been used to evaluate the therapeutic effect for COVID-19. Drug repurposing can win in high efficiency and low cost comparing with the traditional drug discovery strategy. Besides, it has more advantages in treating pandemic, like COVID-19.

Baritinib is a drug to treat rheumatoid arthritis. After outbreak of COVID-19, Benevolent AI Company discovered that AAK1 is a regulatory factor in the process of SARS-CoC-2 infection by generating a drug-knowledge-graph. However, Baritinib can inhibit the activity of AAK1 without obvious side effects. Guney et al. [ 14] quantified the therapeutic effects of drugs and predicted new drug-disease associations by utilizing biological information to measuring the quantified interplay between drug targets and diseases. Zeng et al. [ 15] proposed an integrative deep network to generate a large network containing multiple relationships, collecting a large volume of expectations from PubMed and DrugBank database to embedding the entity as the vector representation. The results showed that 41 repurposable drugs were predicted (including dexamethasone, indomethacin, niclosamide, and toremifene) to be considered as potential therapeutic drugs for treating SARS-CoV-2. The big picture of utilizing machine learning methods to developing drug repurposing is shown in Fig. 2.

The schema of employing machine learning approaches in studying drug repurposing

By constructing a large computational biology network consisting of drugs, genes, and diseases to measure the interaction between target and biomolecule, Chen et al. [ 16] treated drug combination as another form of drug repurposing. Beck [ 17] developed the model MT-DTI ( molecule transformer-drug target interaction) based on the pre-trained drug-target interactions. MT-DTI can be used to signal the affinity of the compounds and target protein to identify commercially available drugs that could act on viral proteins of SARS-CoV-2. The results showed that atazanavir can be used to treat and prevent the human immunodeficiency virus (HIV). Kim et al. [ 18] identified potential associations between drugs and diseases by employing several machine learning methods (logistic regression, random forest, and SVM) by taking into account self-defined similarity metrics (drug-drug similarities and disease-disease similarities). Hooshmand et al. [ 19] mined possible therapeutic drugs to treat SARS-CoV-2 by analyzing the chemical structures of small-molecule drugs.

DeepPurpose [ 20] is a deep learning toolkit for drug-target interaction (DTI) integrating encoding-based approaches of drug molecules and protein amino acid sequences. Belyaeva et al. [ 21] proposed a causal framework using multiple data patterns to generate a causal network consisting of nodes represented by COVID-19 and aging. The method integrated transcriptomics, proteomics, and other omics data to identify a target located in the pathway of COVID-19 infection.

Drug Repurposing with Real-World Data

Researches based on the real world can take advantage of massive data to reflect the actual process of diagnosis, treatment, and the health status of patients in the real situation. Since traditional statistical methods limited in handling the large volume of data, deep learning can be employed to signaling and mining treasures from massive real-world data owing to its outstanding power. Liu et al. [ 22] generated a framework for drug repurposing to estimating the effect of one single drug by taking into account the feature space of existing known drugs. After given a cohort of patients, potential drugs were extracted, and each drug can be categorized to the intervention group and a control group. Confounders and disease progression in the two cohorts were estimated, and LSTM combined with the attention mechanism was used to correct the bias, and finally, a drug with therapeutic effect was obtained.

Drug Repurposing of Traditional Chinese Medicine

Comparing the aforementioned studying in mining small-molecule repurposing drugs, there are a few of studies on using machine learning to find TCM treatment for COVID-19 [ 23]. Wang et al. [ 24] used an ontology-based side-effect prediction framework (OSPF) integrating the neural network-based methods to evaluate the TCM prescriptions officially recommended by China Health Ministry as the treatment of COVID-19. The results showed that QFPD-T, HSBD-F, PMSP, GCT-CJ, SF-ZSY, and HSYF-F can be regarded as the potential therapeutic treatments. Liao et al. [ 25] used deep learning approaches to mine the relationship between patients' facial and prescriptions and propose to construct convolutional neural networks that generate TCM prescriptions according to the patient's face image. Guo et al. [ 26] conducted hierarchical clustering of TCM using unsupervised methods to classify the compounds into several modules with similar therapeutic functions. And the method is to investigate the polypharmacology effect of TCM, benefit to clarifying the mechanism of action of TCM, and providing new possibilities for disease treatment. Weng et al. [ 27] proposed a framework for automated medical knowledge graph construction based on semantic analysis, which automatically extracted semantic reasoning through the graph. The computed TCM prescription can be introduced to diagnosis based on clinical symptoms.

Table 1 describes an overview of computational drug repurposing studies, consisting of the adopted strategies, computational approaches, and main techniques.

Table 1 Summary of computational methods in studying drug repurposing

Summary of Machine Learning Applications in Drug Repurposing

Machine learning methods play a vital role in studying drug repurposing; in which traditional machine learning mainly include, such as Logistic Regression, Random Forest, Support Vector machine, KNN and RotatE, etc. [ 15, 18, 29], which are mainly used in the early stage. During the past decades, deep learning methods own the more significant power in signaling and discovering repurposable drugs, such as RNN [ 1], GCN [ 2], CNN [ 25], GNN [ 7, 28], LSTM [ 22, 30], VAE [ 4], and Transformer methods [ 17]. In addition, deep learning approaches can extract more informative features with respect to molecules and mapping these molecule structures to potential spaces. Since, flow-based models can switch the distribution of features, which have been got more attention [ 5, 6].

Conclusion

Machine learning plays an important role in studying drug repurposing, especially since the occurrence of COVID-19, scientists around the world used machine learning-based approaches to signal effective drugs. At present, there are still some problems, such as the black box problem of deep learning to signaling repurposable drugs causing hard to explain the rationality of the results. It is necessary to develop interpretable deep learning and causal learning along with the traditional drug discovery experiments. Furthermore, it is the fusion problem of the general field of machine learning in drug development, how to better characterize molecules and their conformational changes, to better extract the characteristics of molecules. By developing machine learning methods, we can accelerate drug discovery and improve human health in a way that has never been possible before.

Notes

1.

Acknowledgements

This work was supported by the China Postdoctoral Science Foundation (2019M662373) and the National Key Research and Development Program of China (2020YFC2003500, 2017YFB0202602, 2018YFC0910405, 2017YFC1311003, 2016YFC1302500, 2016YFB0200400, and 2017YFB0202104).

Author information

Affiliations

1. Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China

Fan Yang, Xiaokang Ji & Fuzhong Xue

2. Institute for Medical Dataology, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China

Fan Yang, Qi Zhang, Xiaokang Ji & Fuzhong Xue

3. Institute for Sustainable Industries & Liveable Citie, Victoria University, Melbourne, Australia

Yanchun Zhang

4. Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, 325001, China

Yanchun Zhang

5. College of Computer Science and Electronic Engineering, Hunan University, Changsha, China

Shaoliang Peng

6. School of Computer Science, National University of Defense Technology, Changsha, China

Wentao Li & Shaoliang Peng

7. Peng Cheng Lab, Shenzhen, China

Shaoliang Peng

Corresponding authors

Correspondence to Shaoliang Peng or Fuzhong Xue.

Ethics declarations

Conflict of interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.

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Yang, F., Zhang, Q., Ji, X. et al. Machine Learning Applications in Drug Repurposing. Interdiscip Sci Comput Life Sci (2022). https://doi.org/10.1007/s12539-021-00487-8
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DOI: https://doi.org/10.1007/s12539-021-00487-8

Keywords

Machine learning

Deep learning

COVID-19

Drug repurposing

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Machine Learning Applications in Drug Repurposing - Interdisciplinary Sciences: Computational Life Sciences

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The coronavirus disease (COVID-19) has led to an rush to repurpose existing drugs, although the underlying evidence base is of variable quality. Drug repurposing is a technique by taking advantage of existing known drugs or drug combinations to be explored in an unexpected medical scenario.

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O vídeo explica, objetivamente, as etapas de desenvolvimento de novos medicamentos nos EUA.
É um vídeo interessante e, como é rápido, não se torna cansativo.

#drugdiscovery

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Drug Discovery and Development #drugdiscovery

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Drug Discovery and Development #drugdiscovery

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Olá! Este vídeo mostra um pouco como ocorreu os avanços da pesquisa de desenvolvimento para um medicamento de ação rápida contra a depressão resistente a tratamento, utilizando como base a cetamina.

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National Institute of Mental Health (NIMH)

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Discover NIMH: Drug Discovery and Development

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Neutralização de SARS-CoV-2 Omicron por soros humanos induzidos por vacina de mRNA BNT162b2 #Vacinas

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Neutralização de SARS-CoV-2 Omicron por soros humanos induzidos por vacina de mRNA BNT162b2 #Vacinas

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Um estudo que apresenta 🤬 do pseudovírus das váriantes do covid-19 com soros de pacientes vacinados com 2 ou 3 doses das vacinas baseada em mRNA contra a covid-19.
Os 🤬 foram feitos utilizando ensaios de neutralização do pseudovírus (pVNT) e do SARS-CoV-2 vivos, onde apresentaram uma neutralização efetiva da variante Ômicron devido a terceira dose de vacina.

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Abstract

The globally-circulating SARS-CoV-2 Variant of Concern Omicron (B.1.1.529) has a large number of mutations especially in the spike protein, indicating that recognition by neutralizing antibodies may be compromised. We tested Wuhan, Beta, Delta, or Omicron pseudoviruses with sera of 51 participants that received two or three doses of the mRNA-based COVID-19 vaccine BNT162b2. Following two doses, sera had >22-fold reduced neutralizing titers against Omicron compared to Wuhan pseudovirus. One month after the third vaccine dose, Omicron-neutralizing titers were increased 23-fold compared to two doses, with titers similar to Wuhan-neutralizing titers after two doses. The requirement of a third vaccine dose to effectively neutralize Omicron was confirmed using live SARS-CoV-2 in a subset of participants. These data suggest that three doses of the mRNA vaccine BNT162b2 may protect against Omicron-mediated COVID-19.

Since the first reports of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans in December 2019, numerous genetically distinct lineages have evolved. Among those, variants of concern (VOCs), especially Alpha and Delta variants, were associated with increased viral transmissibility and sparked new waves of infection, with Delta, first designated a VOC on 11th May 2021 (1), quickly becoming a globally dominant variant (2). On November 26th 2021, a new VOC - Omicron - was reported by the World Health Organization (WHO) (3). Omicron is a highly divergent variant and harbors a hitherto unprecedented number of mutations in its spike (S) glycoprotein (4). Fifteen mutations are located in the receptor-binding domain (RBD) and another eight mutated sites are found in the N-terminal domain (NTD), both being immunodominant targets of neutralizing antibodies elicited by COVID-19 vaccines or by SARS-CoV-2 infection (5, 6). Some amino acid changes (Δ69/70, T95I, G142D, Δ145, K417N, T478K, N501Y, and P681H) are shared mutations also found in the Alpha, Beta, Gamma or Delta VOCs and were described to lead to increased transmissibility, and to a typically mild partial escape from vaccine-induced humoral immunity (7-10).

The BNT162b2 COVID-19 mRNA vaccine contains lipid nanoparticle formulated mRNA that encodes the SARS-CoV-2 spike glycoprotein from the parental Wuhan reference strain (11). Administration of two 30-μg doses of BNT162b2 was shown to have 95% efficacy in a Phase 3 trial (12), and shown to elicit strong antibody responses, effectively neutralizing the parental strain as well as diverse SARS-CoV-2 VOCs (13-15). As neutralizing antibody titers are strongly predictive with the degree of immune protection against symptomatic SARS-CoV-2 infection (16), it is important to understand the effect of the new mutations in Omicron on recognition by neutralizing antibodies in convalescent and vaccinated individuals.

To evaluate whether BNT162b2-elicited antibodies (11) are capable of neutralizing the Omicron variant, we used two orthogonal test systems: a pseudovirus neutralization test (pVNT) that has been shown to be in close concordance with live SARS-CoV-2 neutralization assays (17, 18) as well as a live SARS-CoV-2 neutralization test (VNT). For the former, we generated vesicular stomatitis virus (VSV)-SARS-CoV-2-S pseudoviruses bearing the spike proteins of either the Wuhan strain, Omicron, Beta (as a benchmark for partially reduced neutralization (7) without major impact on effectiveness (19, 20)) or Delta (the predominant strain until mid-December 2021). BNT162b2 immune sera from vaccinated individuals between 20-72 years of age (with over one third being 56 years of age and older, table S1) were obtained from different clinical trials - the Phase 1/2 trial BNT162-01 (NCT04380701); the Phase 2 rollover trial BNT162-14 (NCT04949490) conducted in Germany; and the global Phase 2 trial BNT162-17 (NCT05004181) (see methods). Neutralizing titers against VSV-SARS-CoV-2-S pseudoviruses were analyzed with serum drawn from 32 participants from the BNT162-01 trial 21 days (median of 22 days; range 19-23 days) after two doses of BNT162b2 (median time from dose 1 to dose 2 was 21 days; range 19-23 days; table S1), and with serum drawn from 30 participants from the BNT162-14 (n = 11) and BNT162-17 (n = 19) trials at 1 month (median of 28 days; range 26-30 days) after the third dose of BNT162b2 (Median time from dose 2 to dose 3 was 219 days; range 180-342 days). Eleven of the individuals in this analysis were rolled over from the BNT162-01 into the BNT162-14 trial and were included in a longitudinal analysis of neutralizing antibody responses against Wuhan or Omicron variant pseudovirus. These individuals were immunized with a third dose of BNT162b2, with sera collected 1) 21 days (median of 21 days; range 19-23 days) after the second dose, 2) sera collected directly prior to the third dose (median 256 days after dose 2; range 180-342 days), and 3) sera collected at one month (all 28 days) after the third dose.

After two doses of BNT162b2, geometric mean neutralization titers (GMT) against Omicron pseudovirus were 22.8-fold lower compared to the Wuhan reference pseudovirus ( Fig. 1; GMT of 7 vs. 160). 20 out of 32 immune sera displayed no detectable neutralizing activity against Omicron (table S2). In contrast, the majority of sera neutralized Beta and Delta pseudoviruses with GMTs of 24 and 73, respectively. This corresponds to a 6.7-fold and 2.2-fold reduction in neutralization activity compared to the Wuhan pseudovirus and is in line with previous reports (11, 14, 15, 21).

N = 32 sera from participants in trial BNT162-01 drawn at 21 days after dose 2, and n = 30 sera from participants in the BNT162-14 (n = 11) and BNT162-17 trials (n = 19) drawn at 1 month after dose 3 were tested. Each serum was tested in duplicate and geometric mean 50% pseudovirus neutralizing titers (GMTs) were plotted. For values below the limit of detection (LOD), LOD/2 values were plotted. Group GMTs (values) and 95% confidence intervals are indicated.

One month after the third BNT162b2 dose, neutralizing GMTs against the Omicron variant pseudovirus increased 23.4-fold compared to neutralizing GMTs at 21 days after the second dose (GMT of 164 vs. 7); achieving titers comparable to the neutralization against the reference Wuhan pseudovirus at 21 days after two doses of BNT162b2 (GMT of 164 vs. 160). 29 out of 30 sera were capable of neutralizing the Omicron pseudovirus (table S3). The third dose of BNT162b2 also increased neutralizing activity against Beta, Delta and Wuhan pseudoviruses, with GMTs of 279, 413, and 368, respectively.

For 11 individuals that were included in the above analyses a longitudinal analysis of neutralizing titers against Omicron and Wuhan pseudovirus was performed. 21 days after dose 2, sera exhibited a 21.4-fold reduction in GMT against the Omicron variant compared to the Wuhan reference pseudovirus (fig. S1; GMT of 7 vs. 150). Prior to receiving the third dose of BNT162b2 (at a median 256 days following dose 2), neutralizing titers against the Wuhan pseudovirus were considerably reduced (GMT of 13) while the Omicron-specific titers were below the limit of detection. Consistent with the larger serum panel, the third dose of BNT162b2 resulted in a significant increase in neutralizing titers against the Wuhan pseudovirus (GMT of 320) and a 25.8-fold increase in neutralizing titers against Omicron 1 month after dose 3 compared to titers 21 days after dose 2 (GMT of 181 vs. 7).

Sera from a subset of trial participants were analyzed with the second neutralization assay using live SARS-CoV-2 Wuhan and Omicron virus. To this aim, serum from 32 and 25 participants in trial BNT162-01 drawn at 21 days after dose 2, and serum from 7 and 28 participants in the BNT162-14 (n = 7 and n = 11) and BNT162-17 trials (n = 0 and n = 17) drawn at 1 month after dose 3 were tested for neutralization against SARS-CoV-2 Wuhan and Omicron, respectively. Neutralizing GMTs against live SARS-CoV-2 Omicron were 61.3-fold lower compared to the Wuhan reference ( Fig. 2; GMT of 6 vs. 368) at 21 days after two doses of BNT162b2. 17 out of 25 immune sera displayed no detectable neutralizing activity against Omicron (table S4). One month after the third BNT162b2 dose, neutralizing GMTs against Omicron increased 17.6-fold compared to neutralizing GMTs at 21 days after the second dose (GMT of 106 vs. 6) and were 3.4-fold lower as compared to the neutralization against the Wuhan reference at 21 days after two doses of BNT162b2 (GMT of 106 vs. 368). 27 of the 28 post dose 3 sera neutralized live SARS-CoV-2 Omicron (table S5).

Sera from participants in trial BNT162-01 drawn at 21 days after dose 2 were tested for neutralization against SARS-CoV-2 Wuhan (n = 32) and Omicron (n = 25), respectively. Sera from participants in the BNT162-14 (n = 7 and n = 11) and BNT162-17 trials (n = 0 and n = 17) drawn at 1 month after dose 3 were tested for neutralization against SARS-CoV-2 Wuhan (total n = 7) and Omicron (total n = 28), respectively. Each serum was tested in duplicate and geometric mean 50% SARS-CoV-2 neutralizing titers (GMTs) were plotted. For values below the limit of detection (LOD), LOD/2 values were plotted. Group GMTs (values) and 95% confidence intervals are indicated.

The observed SARS-CoV-2 neutralizing GMTs correlated positively with the neutralizing GMTs against VSV-SARS-CoV-2-S pseudoviruses (fig. S2).

BNT162b2 vaccination induces strong poly-epitopic T cell responses, directed against multiple epitopes spanning the length of the spike protein (11). To assess the risk of immune evasion of CD8⁺ T cell responses by Omicron, we investigated a set of HLA class I restricted T cell epitopes from the Wuhan spike protein sequence that were reported in the Immune Epitope Database to be immunogenic (IEDB, n = 244; see methods). Despite the multitude of mutations in the Omicron spike protein, 85.3% (n = 208) of the described class I epitopes were not impacted on the amino acid sequence level, indicating that the targets of the vast majority of T cell responses elicited by BNT162b2 may still be conserved in the Omicron variant (fig. S3).

In summary, our data indicate that two doses of the BNT162b2 mRNA vaccine may not be sufficient to protect against infection with the Omicron variant. In both neutralization assay platforms, we observed a substantial reduction in neutralizing activity for immune sera drawn 21 days after the primary 2-dose series of BNT162b2, confirming preliminary reports describing a 20- to 40-fold reduction in titers (22, 23). Both assays also showed that a third dose of BNT162b2 boosts Omicron neutralization capability to robust levels. While in the pseudovirus assay Omicron neutralization titers after three doses reach a level similar to that observed after two doses against the Wuhan pseudovirus, live SARS-CoV-2 Omicron neutralizing GMTs after dose 3 were 3.4-fold lower compared to post-two dose the Wuhan neutralizing GMTs. The observed variability in specific titers and fold differences between non-replicating pseudovirus and replicating live virus neutralization assay platforms as well as different SARS-CoV-2 strains are not unexpected. Importantly, the overall trends are similar and demonstrate that a third dose of BNT162b2 augments antibody-based immunity against Omicron, in line with previous observations that a third vaccination broadens humoral immune responses against VOCs (24).

The analysis presented here has evaluated and compared serum panels from different clinical trials with a limited sample size. BNT162-01 trial participants received the first two doses of BNT162b2 21 days apart (median 21 days; range 19-23 days), with the timing of the third dose not consistent between participants. Recent reports indicate that longer dosing intervals (>42 days) between the first and second dose improve immunogenicity, potentially resulting in a more favorable outcome (25). Future analyses will evaluate antibody persistence.

Neutralizing antibodies represent a first layer of adaptive immunity against COVID-19. T cell responses play a vital role as a second layer of defense, in particular in the prevention of severe COVID-19 (26). CD8⁺ T cell responses in individuals vaccinated with BNT162b2 are poly-epitopic (11), and our analyses suggest that CD8⁺ T cell recognition of Omicron spike glycoprotein epitopes are largely preserved. Our data show that a third BNT162b2 dose effectively neutralizes Omicron at a similar order of magnitude as was observed after two doses of BNT162b2 against wild-type SARS-CoV-2. Early reports estimate moderate to high vaccine effectiveness against symptomatic Omicron infection especially shortly after dose 3; 65 to 75% has been reported from the UK at 2 to 4 weeks after the booster dose, dropping to 55 to 70% at 5-9 weeks and below 55% from >10 weeks after the third dose (27, 28). Further clinical trial and real-world data will soon emerge to address the effectiveness of a third dose with BNT162b2 against COVID-19 mediated by Omicron.

Acknowledgments

We thank the BioNTech German clinical Phase 1/2 trial (NCT04380701, EudraCT: 2020-001038-36), the German Phase 2 rollover booster trial (NCT04949490, EudraCT: 2021-002387-50) and the global clinical Phase 2 trial (NCT04380701) participants, from whom the post-immunization human sera were obtained. We thank the many colleagues at BioNTech and Pfizer who developed and produced the BNT162b2 mRNA vaccine candidate. We thank S. Jägle for logistical support, and B. Huang for support generating the overview figure S4. We thank the VisMederi team for performing excellent work on live virus-neutralizing antibody assays. We thank C. Heiser, A. Telorman, K. Krüger, C. Müller, A. Wanamaker, N. Williams and J. VanCamp for sample demographics support. Funding: This work was supported by BioNTech and Pfizer. Author contributions: U.S., Ö.T., and A.M. conceived and conceptualized the work. A.M, B.G.L., J.R., H.C., Q.Y., K.A.S and R.G planned and supervised experiments. A.M., A.W., B.G.L, J.M., J.R., M.B., N.B. and R.G. performed experiments. A.M., A.P., B.G.L., J.R., K.A.S., O.O., R.G., and S.S. and analyzed data. U.S., Ö.T., A.M., A.F., and K.A.S. interpreted data and wrote the manuscript. All authors supported the review of the manuscript. Competing interests: U.S. and Ö.T. are management board members and employees at BioNTech SE. A.F., A.M., A.W., B.G.L, J.M., J.R., M.B, N.B., O.O., S.S. and R.G. are employees at BioNTech SE. A.P. is an employee at BioNTech US. U.S., Ö.T. and A.M. are inventors on patents and patent applications related to RNA technology and COVID-19 vaccine. U.S., Ö.T., N.B., A.F., A.M., A.P., A.W., B.G.L., J.M., O.O., J.R., S.S., and R.G. have securities from BioNTech SE; H.C., Q.Y., K.A.S. are employees at Pfizer and may have securities from Pfizer. Data and materials availability: All data are available in the main manuscript or the supplementary materials. Trial participant baseline characteristics are provided in table S1. The neutralization titers are provided in tables S2 to S5. Materials are available from the authors under a material transfer agreement with BioNTech. This work is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/. This license does not apply to figures/photos/artwork or other content included in the article that is credited to a third party; obtain authorization from the rights holder before using such material.

Supplementary Materials

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MDAR Reproducibility Checklist

Other Supplementary Material for this manuscript includes the following:

MDAR Reproducibility Checklist

References and Notes

WHO Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE), Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern (2021).

WHO Headquarters (HQ), WHO Health Emergencies Programme, Enhancing Readiness for Omicron (B.1.1.529): Technical Brief and Priority Actions for Member States (2021).

S. Cele, L. Jackson, D. S. Khoury, K. Khan, T. Moyo-Gwete, H. Tegally, J. E. San, D. Cromer, C. Scheepers, D. Amoako, F. Karim, M. Bernstein, G. Lustig, D. Archary, M. Smith, Y. Ganga, Z. Jule, K. Reedoy, S.-H. Hwa, J. Giandhari, J. M. Blackburn, B. I. Gosnell, S. S. Abdool Karim, W. Hanekom, NGS-SA, COMMIT-KZN Team, A. von Gottberg, J. Bhiman, R. J. Lessells, M.-Y. S. Moosa, M. P. Davenport, T. de Oliveira, P. L. Moore, A. Sigal, SARS-CoV-2 Omicron has extensive but incomplete escape of Pfizer BNT162b2 elicited neutralization and requires ACE2 for infection. medRxiv 2021.12.08.21267417 (2021); .

A. Wilhelm, M. Widera, K. Grikscheit, T. Toptan, B. Schenk, C. Pallas, M. Metzler, N. Kohmer, S. Hoehl, F. A. Helfritz, T. Wolf, U. Goetsch, S. Ciesek, Reduced Neutralization of SARS-CoV-2 Omicron Variant by Vaccine Sera and Monoclonal Antibodies. medRxiv 2021.12.07.21267432 (2021); .

B. Grunau, D. M. Goldfarb, M. Asamoah-Boaheng, L. Golding, T. L. Kirkham, P. A. Demers, P. M. Lavoie, Immunogenicity of Extended mRNA SARS-CoV-2 Vaccine Dosing Intervals. JAMA (2021).

W. Fleri, N. Salimi, R. Vita, B. Peters, A. Sette, Immune Epitope Database and Analysis Resource (2016). Encyclopedia of Immunobiology. 2 (2016).

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Received: 20 December 2021

Accepted: 11 January 2022

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Acknowledgments

We thank the BioNTech German clinical Phase 1/2 trial (NCT04380701, EudraCT: 2020-001038-36), the German Phase 2 rollover booster trial (NCT04949490, EudraCT: 2021-002387-50) and the global clinical Phase 2 trial (NCT04380701) participants, from whom the post-immunization human sera were obtained. We thank the many colleagues at BioNTech and Pfizer who developed and produced the BNT162b2 mRNA vaccine candidate. We thank S. Jägle for logistical support, and B. Huang for support generating the overview figure S4. We thank the VisMederi team for performing excellent work on live virus-neutralizing antibody assays. We thank C. Heiser, A. Telorman, K. Krüger, C. Müller, A. Wanamaker, N. Williams and J. VanCamp for sample demographics support. Funding: This work was supported by BioNTech and Pfizer. Author contributions: U.S., Ö.T., and A.M. conceived and conceptualized the work. A.M, B.G.L., J.R., H.C., Q.Y., K.A.S and R.G planned and supervised experiments. A.M., A.W., B.G.L, J.M., J.R., M.B., N.B. and R.G. performed experiments. A.M., A.P., B.G.L., J.R., K.A.S., O.O., R.G., and S.S. and analyzed data. U.S., Ö.T., A.M., A.F., and K.A.S. interpreted data and wrote the manuscript. All authors supported the review of the manuscript. Competing interests: U.S. and Ö.T. are management board members and employees at BioNTech SE. A.F., A.M., A.W., B.G.L, J.M., J.R., M.B, N.B., O.O., S.S. and R.G. are employees at BioNTech SE. A.P. is an employee at BioNTech US. U.S., Ö.T. and A.M. are inventors on patents and patent applications related to RNA technology and COVID-19 vaccine. U.S., Ö.T., N.B., A.F., A.M., A.P., A.W., B.G.L., J.M., O.O., J.R., S.S., and R.G. have securities from BioNTech SE; H.C., Q.Y., K.A.S. are employees at Pfizer and may have securities from Pfizer. Data and materials availability: All data are available in the main manuscript or the supplementary materials. Trial participant baseline characteristics are provided in table S1. The neutralization titers are provided in tables S2 to S5. Materials are available from the authors under a material transfer agreement with BioNTech. This work is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/. This license does not apply to figures/photos/artwork or other content included in the article that is credited to a third party; obtain authorization from the rights holder before using such material.

Authors

Affiliations

BioNTech, An der Goldgrube 12, 55131 Mainz, Germany.

HI-TRON - Helmholtz Institute for Translational Oncology Mainz by DKFZ, Obere Zahlbacherstr. 63, 55131 Mainz, Germany.

BioNTech, An der Goldgrube 12, 55131 Mainz, Germany.

TRON gGmbH - Translational Oncology at the University Medical Center of the Johannes Gutenberg, University Freiligrathstraße 12, 55131 Mainz, Germany.

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# data[].attributes.attachment_link.title
Neutralization of SARS-CoV-2 Omicron by BNT162b2 mRNA vaccine-elicited human sera

# data[].attributes.attachment_link.description
The globally-circulating SARS-CoV-2 Variant of Concern Omicron (B.1.1.529) has a large number of mutations especially in the spike protein, indicating that recognition by neutralizing antibodies may be compromised. We tested Wuhan, Beta, Delta, or Omicron pseudoviruses with sera of 51 participants that received two or three doses of the mRNA-based COVID-19 vaccine BNT162b2.

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E aí, pessoal. Hoje trouxe esse vídeo curtinho que explica de uma forma bem simples a farmacogenômica. Ele mostra que informações famacogenômicas podem ser relevantes ao longo da vida de uma pessoa.
PS: o vídeo tá em inglês, mas o YouTube disponibiliza a tradução das legendas pra português.

#farmacogenômica

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MEDICINA TRADICIONAL KAINGANG NA COMUNIDADE DA TERRA INDÍGENA CHAPECÓ: ENTEROPARASITORES, FATORES SOCIOAMBIENTAIS E SEU ENFRENTAMENTO #drugdiscovery

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MEDICINA TRADICIONAL KAINGANG NA COMUNIDADE DA TERRA INDÍGENA CHAPECÓ: ENTEROPARASITORES, FATORES SOCIOAMBIENTAIS E SEU ENFRENTAMENTO #drugdiscovery

# data[].attributes.body
Olá, pessoal. Trago pra vocês um trabalho fruto de uma ação extensionista, que buscou entender os hábitos relacionados à medicina tradicional em uma terra indígena de Chapecó, em Santa Catarina.

O estudo analisou amostras de 67 moradores da aldeia para verificar a presença de esteroparasitoses, e encontrou apenas uma amostra positiva. Dito isso, o estudo buscou avaliar quais ervas ou produtos naturais eram utilizados que pudessem conter essa atividade antiparasitária. Foram identificadas cerca de 20 ervas possivelmente responsáveis por conter essas doenças.

Com esse estudo pode-se ter ideia de onde começa uma prospecção de espécies que contém substâncias bioativas para o possível desenvolvimento de um medicamento, ressaltando a necessidade do conhecimento tradicional associado a essas culturas.

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022 MEDICINA TRADICIONAL KAINGANG NA COMUNIDADE DA TERRA

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Medicina personalizada no tratamento do câncer #farmacogenômica

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Medicina personalizada no tratamento do câncer #farmacogenômica

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Olá, pessoal. Trago pra vocês este artigo falando sobre a farmacogenômica e a medicina personalizada no tratamento do câncer.

Um dos pontos interessantes do artigo é quando é explicado que 95% das reações adversas a medicamentos pode ser explicada por fatores genéticos. Nesse sentido, doenças como o câncer sofrem para adequar tratamentos a pacientes com perfis genéticos diversos, e para isso, se vê um desafio proporcionar um tratamento personalizado para o paciente.

Tal artigo de revisão estuda as diferentes reações adversas e suas relações com diferenças genéticas por meio da revisão de 11 artigos da área.

Espero que gostem!

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Medicina personalizada no tratamento do câncer/Personalized medicine in cancer treatment | Teixeira | Brazilian Journal of Health Review

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Medicina personalizada no tratamento do câncer/Personalized medicine in cancer treatment

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Teste farmacogenômico mostra com precisão medicamentos mais eficazes a cada indivíduo #farmacogenômica

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Teste farmacogenômico mostra com precisão medicamentos mais eficazes a cada indivíduo #farmacogenômica

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Oii pessoal, vimos na aula um pouco sobre os 🤬 farmacogenômicos e sua importância na hora de conhecer a reação do organismo a determinado medicamento de forma individualizada.
Dessa forma, resolvi trazer um pouco mais de conteúdo sobre esse tópico :)

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Exame genômico de última geração possibilita, de forma personalizada, que pacientes que fazem uso contínuo de medicamentos consigam melhora da qualidade de vida e redução de efeitos colaterais e gastos com remédios desnecessários
Um painel dinâmico que avalia uma importante parte do seu metabolismo e que demonstra, com precisão, como cada medicamento reage no seu organismo, a interação com outras drogas, com alimentos e até com muitos dos seus hábitos de vida. É neste formato inovador e de forma individualizada que o novo teste da GeneOne, laboratório de medicina genômica da Dasa, apresenta seu laudo interativo.

O exame analisa o DNA do paciente e fornece um panorama completo que indica como algumas rotinas da vida e medicamentos de uso contínuo agem no corpo da pessoa. Dessa forma, remédios que não têm indicadores tangíveis, como os psiquiátricos, ganham um aliado para ajuste de prescrições, troca ou exclusão de medicamentos que estejam causando reações indesejadas. Sem estes dados, esse processo pode levar tempo e implicar em desgaste, muitas vezes ocasionando gastos desnecessários ou o abandono do tratamento.

"Este teste possibilita que médicos e pacientes possam prever, antes mesmo de receitar ou comprar o medicamento, as chances de um resultado mais satisfatório, com mais respostas e menos efeitos colaterais", comenta Leandro Brust, responsável técnico pela área de farmacogenômica da Dasa.

Medicamentos para tratamento psiquiátrico e psicológico são amplamente consumidos no Brasil. Estudo da Funcional Health Tech - empresa de inteligência de dados de saúde - revelou que, de 2014 a 2018, o consumo de antidepressivos cresceu 23% por aqui e, segundo a OMS, o Brasil lidera o ranking de estresse e ansiedade na América Latina, com 5,8% da população com depressão e 9,3%, com transtornos de ansiedade. "Atualmente, o paciente precisa usar um medicamento pelo período que o médico determinar e então relatar como se sente - melhor, pior ou igual, ajustando a dosagem de acordo com sua melhora ou piora. O avanço da medicina genômica funciona como um suporte para médico e paciente, para ser preciso, assertivo e contribuir para a melhora do quadro geral da pessoa", explica Gustavo Campana, diretor médico da Dasa.

Em parceria com a Coriell Life Science, companhia americana referência em farmacogenômica, a GeneOne disponibiliza painel que pode ser atualizado no momento que o paciente faz o teste e ao longo da sua vida.

Segundo a American Heart Association, alguns alimentos, inclusive os considerados saudáveis, também podem tornar medicações menos eficientes. Ou seja, não só os remédios têm a capacidade de reagir entre si, mas práticas como o tabagismo e o sedentarismo também influenciam a genética e a resposta do organismo.

"Por isso a importância de o painel ser vivo. É possível incluir se a pessoa está consumindo mais álcool ou se está grávida, pois sabemos que o cenário externo influencia reações em nosso organismo. A possibilidade de avaliar a conduta a partir de dados precisos e personalizados é um ganho de tempo no tratamento que obviamente se reflete em economia da saúde", explica Campana.

O painel apresenta uma relação de 103 medicamentos que já possuem uma informação farmacogenômica consolidada, todos eles aprovados pelo FDA, órgão regulador dos Estados Unidos e uma referência mundial, e uma lista de atividades e hábitos que podem ser escolhidas para compor o perfil. Médico ou o próprio paciente podem fazer esta seleção e monitorar o painel, de forma segura e restrita, com login e senha. Também permite que sejam incluídos dados de histórico de patologias e outros quadros, fixos ou temporários. O laudo é dinâmico e atemporal e a lista principal dos medicamentos vai aumentando ao longo do tempo.

O exame é realizado uma só vez e de maneira muito simples, via coleta de sangue ou amostra de saliva em uma das quase 900 unidades de laboratórios da Dasa, em marcas como Alta (SP e RJ), Delboni (SP) e Sergio Franco (RJ) ou também via Atendimento Domiciliar. O prazo para o processamento do exame é de 40 dias úteis. E não há restrição de idade para fazer o exame, por isso crianças que precisem de tratamentos com medicações também podem realizá-lo.

"Por fim, normalmente, pessoas mais velhas tendem a tomar vários remédios. Com o auxílio deste teste, podemos considerar um impacto positivo inclusive no custo das hospitalizações, na produtividade das pessoas e, em última instância, até em como a rotina com suas famílias é impactada. E afinal, se você estivesse tomando um remédio que lhe faz mal, você não gostaria de saber?", conclui Campana.

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Teste farmacogenômico mostra com precisão medicamentos mais eficazes a cada indivíduo

# data[].attributes.attachment_link.description
Exame genômico de última geração possibilita, de forma personalizada, que pacientes que fazem uso contínuo de medicamentos consigam melhora da qualidade de vida e redução de efeitos colaterais e gastos com remédios desnecessários Um painel dinâmico que avalia uma importante ...

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Molécula com forte ação antitumoral desenvolvida por pesquisadores brasileiros para tratar câncer de mama #biofarmacos 

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Molécula com forte ação antitumoral desenvolvida por pesquisadores brasileiros para tratar câncer de mama #biofarmacos 

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Um grupo de pesquisadores que fazem parte da startup brasileira PHP Biotech oferecem tratamento para o câncer de mama mais agressivo.
Se trata de uma molécula sintetizada em laboratório, a 3-NAntC. É uma molécula inspirada em um composto que é encontrado na nossa biodiversidade brasileira!
É um novo tratamento para esse tipo de câncer de mama mais agressivo. Além disso, oferece uma chance de tratamento menos agressiva e menos efeitos colaterais.

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A startup PHP Biotech, sediada em Botucatu, no interior de São Paulo, tem um desafio e uma esperança em vista: oferecer a mulheres com câncer de mama triplo negativo, o tipo mais agressivo da doença, um novo e efetivo tratamento.

A história, ainda sendo escrita, começou há cerca de 15 anos com pesquisas feitas numa universidade paulista, passou pelas mãos de um empreendedor com mais de duas décadas de experiência com inovações em saúde, avançou por testes em outra universidade e, a partir da criação de uma healthtech nacional, caminha agora com a realização dos estudos pré-clínicos, aqueles que antecedem o teste em humanos.

O candidato a medicamento, batizado de 3-NAntC, é uma molécula concebida e sintetizada em laboratório cuja inspiração é um composto originalmente encontrado na biodiversidade brasileira - a fonte exata será divulgada assim que for concluído o processo de patente do produto.

"Sabíamos que a substância original tinha uma ação antitumoral, mas ao mesmo tempo apresentava alta toxicidade. O que nossos cientistas fizeram foi desenvolver uma nova molécula só com o efeito de combate ao câncer e modificada para ser ainda mais eficiente nisso", resume Moacyr Bighetti, CEO da PHP Biotech e o empreendedor desta história.

A descoberta do composto natural e o aperfeiçoamento até a versão sintética com potencial de virar remédio é obra do biofísico Marcos Fontes, professor da Universidade Estadual Paulista (Unesp) de Botucatu e hoje consultor técnico do projeto.

De olho num futuro biofármaco, Bighetti levou a molécula à Universidade de São Paulo (USP) em Ribeirão Preto, onde ela seria testada no laboratório da farmacêutica Maria Regina Torqueti. E foi assim que uma aluna de pós-doutorado da professora entrou na história, a biotecnologista Patrícia Bezerra, hoje a principal pesquisadora a investigar a 3-NAntC.
+ LEIA TAMBÉM: Os desafios e os avanços contra o câncer de mama
Orientada por Maria Regina, Patrícia avaliou o efeito da molécula em modelos de células de câncer de mama, um expediente normalmente utilizado para analisar o potencial de um medicamento. E o que mais chamou a atenção foi sua ação contra células do câncer de mama triplo negativo, que, apesar de ser menos prevalente, é o mais agressivo.

"Esse tumor tem poucas opções terapêuticas além da quimioterapia, e entre 30 e 45% das pacientes vão a óbito cinco anos após o diagnóstico. Das sobreviventes, 30% ainda acabam apresentando uma recidiva em cinco anos", conta Patrícia. Para tornar a situação mais dramática, a doença tem maior capacidade de se espalhar, gerando metástases em outros órgãos como o pulmão, e costuma afetar mulheres com menos de 40 anos.

Atualmente, fora a quimioterapia - que nem sempre obtém sucesso e gera muitos efeitos colaterais -, apenas 30% das pacientes com câncer de mama triplo negativo são beneficiadas com uma terapia-alvo (a classes dos inibidores de PARP). Mais recentemente, boas expectativas envolvem o tratamento com imunoterapia e os chamados anticorpos conjugados.

Continua após a publicidade

Candidata brasileira

A ideia da PHP Biotech é alargar o arsenal terapêutico. Para isso, a molécula 3-NAntC foi avaliada em ensaios in vitro (culturas de células), encarou testes com peixes-zebra na Suécia - esse é um modelo animal cada vez mais utilizado em biologia - e ainda passou por simulações computadorizadas para compará-la a milhares de substâncias parecidas pelo mundo.

"Nossos experimentos mostraram que a 3-NAntC matou 30% das células de câncer de mama triplo negativo num período de 48 horas. E menos de 5% das células saudáveis foram afetadas", relata Patrícia. O resultado foi considerado animador pela equipe, porque, na quimioterapia-padrão, calcula-se que o tratamento destrua duas células tumorais para cada célula normal. Com a nova molécula, a razão ficou em 6 para 1.

Mas como ela funciona? Patrícia conta que tudo leva a crer que a substância induza a apoptose das células doentes. É como se ela se conectasse às unidades do tumor e as estimulasse a um suicídio programado. "Daí uma célula do sistema imune vem e termina com a célula cancerosa", pontua a biotecnologista.
+ Assine VEJA SAÚDE a partir de R$ 12,90 mensais
É diferente do modelo de ataque da químio, por exemplo, em que a aniquilação do tumor ocorre por necrose. "Nesse caso, é como se um homem-bomba aparecesse e se detonasse entre as células", compara a pesquisadora.

Além da ação mais precisa contra a doença, o que é importante para o efeito em si mas também para a redução das reações adversas, Bighetti ressalta que, pelos testes até o momento, o biofármaco ainda inibe a proliferação das células tumorais, sem se intrometer nas sadias.

A healthtech aguarda agora o aval da FDA, a agência reguladora de medicamentos dos Estados Unidos, para iniciar os estudos com animais e, posteriormente, com humanos em solo americano. O CEO da startup explica que a escolha por dar sequência aos testes ali tem a ver com a maior viabilidade de avançar em meio a regras e burocracias. "Esperamos começar a fase 1 de pesquisa, em humanos, no início de 2023", revela Bighetti.

A expectativa é que a molécula reproduza os resultados promissores vistos em laboratório em gente como a gente, uma das etapas mais difíceis no desenvolvimento de remédios - nem sempre compostos bem-sucedidos num primeiro momento passam pelas provas clínicas. "Nosso propósito, nesse projeto que é tocado cientificamente por uma mulher, é mudar o tratamento do câncer de mama triplo negativo, trazendo esperança às mulheres que enfrentam a doença", diz o CEO da startup.

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Promessa brasileira para o tratamento do câncer de mama mais agressivo

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A startup PHP Biotech, sediada em Botucatu, no interior de São Paulo, tem um desafio e uma esperança em vista: oferecer a mulheres com câncer de mama triplo negativo, o tipo mais agressivo da doença, um novo e efetivo tratamento.

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Anticorpos monoclonais no combate à febre amarela #anticorpos

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Anticorpos monoclonais no combate à febre amarela #anticorpos

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Olá pessoal! Quem nunca ouviu falar dos temores da febre amarela? Uma doença infecciosa grave, transmitida por vetores como o Aedes aegypti por exemplo e que há anos vem sendo amplamente estudada.
Por isso, resolvi trazer essa notícia com mais um estudo sobre a febre amarela e dessa vez com anticorpos monoclonais como uma rota alternativa. Ficou interessado? Já corre pra ler!!

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Pesquisadores da Faculdade de Medicina Albert Einstein, nos Estados Unidos, em parceria com o Instituto Oswaldo Cruz (IOC/Fiocruz) e a Universidade de São Paulo (USP), além de outras instituições, deram um importante passo em busca de uma terapia contra a febre amarela. Considerados tendência mundial, os anticorpos monoclonais sintéticos têm sido alvo de estudos mundo afora. Produzidos em laboratório, esses anticorpos se ligam a uma região específica da partícula do vírus, interrompendo o processo de infecção.

Medicamentos desse tipo foram desenvolvidos, por exemplo, para tratamento da Covid-19 e da Zika. Na febre amarela, os fármacos podem ser uma alternativa para o tratamento de infecções e para a profilaxia, considerando pessoas que viajam para áreas de risco, mas não podem se vacinar por causa de contraindicações.

Os primeiros resultados do estudo recém-publicado na revista científica 'Cell Host & Microbe' apresentam o mapeamento de variações de aminoácidos que alteram a superfície da partícula viral, dificultando a ação de algumas classes de anticorpos.

"Os anticorpos monoclonais são baseados em anticorpos naturais, produzidos pelo organismo. Nosso estudo mostra que é obrigatório selecionar as moléculas contra a febre amarela considerando os vírus que circulam em cada região, porque alguns anticorpos que neutralizam o vírus vacinal e outras cepas de origem africana não foram capazes de neutralizar os vírus da América do Sul", adianta a pesquisadora, Myrna Bonaldo, chefe do Laboratório de Biologia Molecular de Flavivírus do IOC e uma das autoras do artigo.
Variação mapeada
Na primeira etapa do estudo, os pesquisadores avaliaram a capacidade do soro de pessoas vacinadas - que contém dezenas de tipos de anticorpos induzidos pela imunização - para neutralizar diferentes linhagens virais. Foram consideradas as linhagens utilizadas nas formulações da vacina da febre amarela no Brasil e nos Estados Unidos, sendo ambas versões atenuadas de um vírus isolado na África, em 1927, e uma linhagem isolada no Brasil, em 2017. A neutralização do vírus brasileiro foi significativamente menor do que a dos vírus vacinais.

Em seguida, os cientistas investigaram a capacidade de atuação de cerca de cem anticorpos monoclonais, produzidos com base nos anticorpos naturais presentes no soro de pessoas vacinadas.

"Detectamos que a capacidade de neutralização de algumas moléculas que eram muito reativas para o vírus vacinal caiu para zero contra o vírus brasileiro. Os experimentos apontaram que os anticorpos que falhavam tinham um alvo comum: o domínio II da proteína E", diz a doutoranda do Programa de Pós-graduação em Biologia Celular e Molecular do IOC e também autora do estudo, Nathalia Dias Furtado.

A proteína E forma o envelope que reveste a partícula viral e apresenta três segmentos expostos na superfície do vírus, chamados de domínios I, II e III. A molécula tem um papel importante na infecção. Ela atua como uma chave, que se liga à célula hospedeira, promovendo a abertura da membrana celular para a penetração do vírus. Por isso, para bloquear a infecção, os anticorpos miram nos diferentes segmentos da proteína E.

Comparando o vírus brasileiro com a linhagem vacinal e outros dois vírus de origem africana, os pesquisadores identificaram variações em dois pontos no domínio II da proteína E. Segundo os cientistas, essas alterações explicam por que uma parte dos anticorpos perde a capacidade de neutralizar o vírus. "Anticorpos que têm como alvo outros domínios da proteína E permanecem capazes de atuar. Mas, sem o efeito dos anticorpos que miram no domínio II, a potência de neutralização total do soro de pessoas vacinadas cai", comenta Nathalia.

A etapa final do trabalho consistiu na análise de 281 sequências genéticas do vírus da febre amarela disponíveis em bancos de dados. Olhando para região do genoma referente à proteína E, os pesquisadores observaram que as mutações nos dois pontos do domínio II estavam presentes em quase todos os vírus do genótipo I Sul Americano, que é predominante no Brasil. Já os vírus do genótipo II da América do Sul, encontrados com maior frequência na Bolívia, Peru, Equador, apresentaram apenas um dos pontos de variação. Enquanto isso, nenhum vírus de origem africana exibiu este tipo de variação na proteína do envelope.
Adaptação ao Novo Mundo
Para as autoras da pesquisa, os dados indicam que as mutações fazem parte do processo de adaptação do vírus da febre amarela ao Novo Mundo. "O vírus da febre amarela se originou na África e foi trazido para as Américas com o tráfico de escravos. Aqui, ele encontrou espécies de mosquitos e primatas não humanos diferentes das que existiam no continente africano e isso forçou uma adaptação, que provavelmente ocorreu séculos atrás", aponta Nathalia.

Chamando atenção para o ciclo silvestre da febre amarela, as pesquisadoras destacam ainda que a evolução genética do patógeno é motivada principalmente por fatores ecológicos e não busca "escapar da vacina". "O vírus da febre amarela precisa se replicar em dois hospedeiros muito diferentes, um inseto e um mamífero. A proteína E tem que ser uma chave-mestra. Isso gera uma pressão seletiva para que o vírus se mantenha estável, porque se ele se adapta muito a um tipo de hospedeiro, corre risco de perder a adaptação ao outro. Se isso acontece, ele é eliminado da natureza", explica Myrna.

A pesquisadora enfatiza ainda a diferença em relação ao SARS-CoV-2, causador da Covid-19, que começou a se disseminar há pouco tempo na população humana, com transmissão direta de uma pessoa para a outra e taxa de mutação alta. "Escapar da vacina pode ser uma vantagem evolutiva importante para o SARS-CoV-2, mas não é um fator central para o vírus da febre amarela, que tem um ciclo silvestre e já está bem estabelecido na natureza há séculos", salienta.
Eficácia da vacina
Segundo as pesquisadoras, apesar da menor capacidade de neutralização dos anticorpos, a eficácia da vacina contra a febre amarela pode se manter elevada devido a outros mecanismos imunológicos.

"Em termos práticos, mesmo com as diferenças observadas, temos uma vacina eficaz, que tem sido poderosa para controlar surtos tanto na África como na América do Sul", afirma Myrna, lembrando que as epidemias mais recentes de febre amarela no Brasil se espalharam em contextos de baixa cobertura vacinal e foram controladas com o avanço da imunização.

"Os anticorpos são apenas uma parte da resposta imune. A vacinação estimula, por exemplo, as células T CD8 citotóxicas, que são muito importantes para reconhecer e eliminar células infectadas", acrescenta Nathalia.

As autoras do trabalho apontam ainda que existem diversas pesquisas em andamento para desenvolver novas vacinas da febre amarela, utilizando tecnologias diferentes da vacina atual, que tem como base um vírus vivo atenuado. Entre as opções em estudo estão uso de vírus inativado, vetor viral, RNA mensageiro e antígeno.

Neste contexto, os dados obtidos na pesquisa podem orientar a busca de formulações capazes de estimular a produção de anticorpos contra diferentes linhagens virais. "Com tecnologias mais avançadas, é possível pensar em uma vacina múltipla. Porém, para isso, os estudos terão que provar que as novas formulações são mais eficazes do que a vacina atualmente utilizada", pondera Myrna.

*Edição: Vinícius Ferreira (IOC/Fiocruz)

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pesquisa com anticorpos monoclonais sintéticos

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Febre amarela: pesquisadores buscam nova terapia contra a doença

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Pesquisadores da Faculdade de Medicina Albert Einstein, nos Estados Unidos, em parceria com o Instituto Oswaldo Cruz (IOC/Fiocruz) e a Universidade de São Paulo (USP), além de outras instituições, deram um importante passo em busca de uma terapia contra a febre amarela. Considerados tendência mundial, os anticorpos monoclonais sintéticos têm sido alvo de estudos mundo afora.

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The Drug Discovery & Development Process

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The Drug Discovery & Development Process

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Olá, pessoal!

Para falar um pouco sobre Drug Discovery, eu resolvi trazer esse conteúdo produzido pela empresa da indústria farmacêutica Boehringer Ingelheim. Ele traz informações sobre tempo e investimento necessários na descoberta de novas drogas, além de um vídeo que explica rapidamente o processo de produção de um novo medicamento. Bem interessante!

#DrugDiscovery

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From initial discovery to a marketable medicine is a long, challenging road. It takes about 12 - 15 years from discovery to the approved medication and requires an investment of about US $1 billion. On average, from more than a million screened molecules only one is investigated in late stage clinical trials and is finally made available for patients.

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From initial discovery to a marketable medicine is a long, challenging road. It takes about 12 - 15 years from discovery to the approved medication and requires an investment of about US $1 billion. On average, from more than a million screened molecules only one is investigated in late stage clinical trials and is finally made available for patients.

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Encontrei esse artigo publicado em março de 2020, que traz um apanhado de informações sobre o uso da farmacogenômica na neurociência, mais especificamente em tratamentos antidepressivos e antipsicóticos, sendo possível inclusive identificar polimorfismos clinicamente relevantes.
É um artigo bem interessante, vale a pena a leitura!

#Farmacogenomica

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Department of Psychiatry, Parnassia Group, Amsterdam, Netherlands

Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands

Departments of Psychiatry and Medical Genetics, University of Alberta, Edmonton, AB, Canada

Pharmacogenetics Section, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden

Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia

In recent decades, very few new psychiatric drugs have entered the market. Thus, improvement in the use of antidepressant and antipsychotic therapy has to focus mainly on enhanced and more personalized treatment with the currently available drugs. One important aspect of such individualization is emphasizing interindividual differences in genes relevant to treatment, an area that can be termed neuropsychopharmacogenomics. Here, we review previous efforts to identify such critical genetic variants and summarize the results obtained to date. We conclude that most clinically relevant genetic variation is connected to phase I drug metabolism, in particular to genetic polymorphism of CYP2C19 and CYP2D6. To further improve individualized pharmacotherapy, there is a need to take both common and rare relevant mutations into consideration; we discuss the present and future possibilities of using whole genome sequencing to identify patient-specific genetic variation relevant to treatment in psychiatry. Translation of pharmacogenomic knowledge into clinical practice can be considered for specific drugs, but this requires education of clinicians, instructive guidelines, as well as full attention to polypharmacy and other clinically relevant factors. Recent large patient studies (n > 1,000) have replicated previous findings and produced robust evidence warranting the clinical utility of relevant genetic biomarkers. To further judge the clinical and financial benefits of preemptive genotyping in psychiatry, large prospective randomized trials are needed to quantify the value of genetic-based patient stratification in neuropsychopharmacotherapy and to demonstrate the cost-effectiveness of such interventions.

Introduction

Despite intensive effort in neuroscience research, very few new psychopharmacological agents have entered the market during recent decades. Antidepressants in general aim to increase monoaminergic neurotransmission by blocking monoamine reuptake, while antipsychotics mostly aim to reduce mesolimbic dopaminergic neurotransmission by blocking receptors including D ₂ and 5-HT 2A receptors ( 1). However, these effects are neither necessary nor sufficient for a favorable treatment response and the effectiveness of therapy is therefore suboptimal. Current selection of an appropriate antipsychotic or antidepressant drug to a great extent still relies on psychiatrists' clinical experience as well as on a potentially long trial and error approach, with potential serious adverse reactions such as suicidal ideation and behaviors. Moreover, while antidepressants and antipsychotics are superior compared to placebo ( 2, 3), their efficacy is not impressive keeping in mind the effect size of superiority over placebo ( 4). Since molecular targets for psychiatric drugs are not yet fully elucidated, many of the currently available drugs will likely remain the cornerstone of pharmacotherapy in psychiatry for the foreseeable future. It is therefore of paramount value to maximize their effectiveness prospectively by treatment personalization.

In general, differences between individuals in drug treatment response can be caused by environmental, physiological, and psychological factors, as well as by comorbidities and genetic variability ( 5, 6). With respect to the genetic component, one can estimate that roughly one quarter of the total variability in drug response is genetic in origin ( 7). To facilitate the transfer of genetic information to physicians, regulatory agencies incorporate pharmacogenomic drug labels into the summaries of product information (SmPC); here they specify which of the genetic variation information is important to consider with regard to drug prescription. Such drug labels include mandatory guidelines, recommendations and information about how pharmacogenomic variation should be taken into account regarding the indication or dosage - data that are expected to be beneficial for individualization of drug therapy ( 6). In addition two different organizations, CPIC (Clinical Pharmacogenetics Implementation Consortium) and DPWG (Dutch Pharmacogenetics Working Group) publish similar guidance based on their own expertise and judgment. It was published recently however, that the concordance among pharmacogenomic drug labels between FDA, EMA, DPGW, and CPIC is low and of drugs considered by all agencies; for only 18% of them is the information similar across the four agencies ( 8). For pharmacogenomic drug labels provided by the FDA and the EMA (or the Dutch or the German MPAs), the concordance is low ( 8, 9), in contrast to the high concordance between the FDA and the EMA regarding the approval of new drugs ( 10). Furthermore, the use of such labels in a clinical setting is relatively limited apart from in oncology ( 11).

There is substantial interindividual variability in the response and efficacy of CNS active drugs and it has become evident that genes encoding pharmacokinetic-related biomolecules have significant impact ( https://cpicpgx.org/guidelines/). In particular, functional polymorphisms in genes encoding the drug metabolizing enzymes CYP2C19 and CYP2D6 are quite frequent among all populations ( 12) and these variants are associated with altered drug exposure sufficiently to support the clinical utility of CYP2C19 and CYP2D6 genotyping ( 13- 15). In contrast, receptors that are currently used as drug targets for psychiatric drugs are evolutionary conserved to a higher extent than genes encoding drug metabolism and the actionability of pharmacodynamic-related genotyping is currently still questionable ( 16). However, when the functional interpretation of common or rare variants in such genes becomes available, it is clear that such pharmacogenomic information can be used to improve pharmacotherapy individualization ( 17).

Many findings to date in the field of pharmacogenomics in psychiatry have lacked consensus and yielded a lot of controversy. We herein review the most important studies in the field and summarize the current situation, outline future directions, and discuss possible implementation of genetic biomarkers in psychiatry with a particular focus on the CYP2C19 and CYP2D6 genes.

Biomarkers Based on Genes Coding Drug Metabolizing Enzymes

In phase I, drugs are usually transformed by oxidation, demethylation, reduction, or hydrolysis to more soluble compounds, which facilitates their subsequent elimination from the body. A major phase I enzyme family is the cytochrome P450s (CYPs), whose activity usually leads to the reduction of drug potency. The human liver possesses a wide spectrum of CYP isoforms; the most abundant isoforms (CYP1A2, CYP2C9, and CYP3A4/5) ( 18) account for more than half of total CYP content in the human liver and they participate in metabolism of roughly one third of psychiatric drugs ( 19). Importantly, certain drugs are known to induce or inhibit these enzymes and consequently, polypharmacy can affect the exposure of many psychiatric drugs ( https://drug-interactions.medicine.iu.edu/MainTable.aspx). In addition, one recently published and adequately powered study suggests that the CYP1A2 SNP rs2472297 may predict clozapine exposure ( 20) and potentially affect clozapine treatment. However, at this point, CYP2C19 and CYP2D6 enzymes seem to be more important for pharmacogenetics in psychiatry, since they contribute significantly to the phase I metabolism of more than two thirds of all currently available psychiatric drugs ( 19). Whilst CYP2C19 and CYP2D6 are much less abundantly expressed in the human liver than the other CYPs mentioned above, they seem to have a very high affinity for the molecular structures on which most of the currently available psychiatric drugs are based. However, unlike the major form of hepatic CYP3A P450 isoform CYP3A4 ( 21), the CYP2D6 and CYP2C19 genes are highly polymorphic, and this genetic variation is associated with profound changes in enzymatic capacity ( Tables 1 and 2). Owing to this genetic variability with demonstrated clinical relevance, all currently commercially available pharmacogenetic-based decision-support tools in psychiatry encompass the common variants in the CYP2C19 and CYP2D6 genes ( 13). However, in order to appropriately personalize treatment based on CYP2C19/CYP2D6 genotype in psychiatry, prescribers need to know (i) how and in what depth CYP2C19/CYP2D6 genotyping should be performed, (ii) the relationship between genotypic variation and the relevant linked phenotypes, and (iii) how to appropriately use this information to improve pharmacotherapy. While admirable progress in this regard has been made to date, certain research and clinical application gaps still remain to be addressed.

Table 1 Relation between genotype and phenotype among diploid genotypes of CYP2C19 and CYP2D6.

Table 2 world-wide frequencies of common variant CYP2C19 and CYP2D6 alleles.

CYP2C19 and CYP2D6 Functional Variant Genotyping

Functional CYP2C19 and CYP2D6 genetic variants include: (1) variants or Null alleles that encode nonfunctional proteins; (2) variants that cause a decrease in enzyme capacity or transcription levels compared to normal alleles, but not complete lack of enzyme; and (3) variants that result in an increase in enzyme capacity or transcription levels ( 12). Moreover, the CYP2D6 gene belongs to one of the most complicated and polymorphic loci in the whole of the human genome ( 23). Deletion of the entire gene ( CYP2D6*5) and duplication/multiplication of the gene (e.g., CYP2D6Wtx2/N) occur frequently worldwide ( 12). For all genetic variants, a distinction between common (MAF > 1%) and rare (MAF < 1%) variants can be made. The frequencies of common CYP2C19 and CYP2D6 functional variant alleles worldwide, as previously described by ( 12), are listed in Table 1.

Currently, CYP2C19, CYP2D6 and other CYP genotyping assays mostly cover only common variants, which is understandable from an economic point of view; however, there is an abundance of rare CYP2C19 and CYP2D6 variant alleles ( 24) ( https://www.pharmvar.org/gene/CYP2D6). Thus, a substantial fraction of genetically caused variation in drug metabolism cannot be resolved unless extensive sequencing efforts are carried out in a psychiatric setting. The examination of big datasets from, for example, the EXAC consortium, reveals that among all mutations seen based on whole exome sequencing of > 67,000 individuals, rare mutations account for over 90% of the number of unique SNVs and 50% of the SNVs identified are seen in only one individual ( 24). The total contribution of rare SNVs to interindividual variation in drug response is difficult to estimate but one quarter of the total variation appears to be a realistic figure ( 25). This means that in clinical practice, a substantial amount of the true functional genetic variation of drug metabolizing enzymes is not detected by using the commercially available genotyping tools. The importance of rare, often de novo, variants contribution for explaining interindividual variation in drug pharmacokinetics is also supported by results from twin studies where the differences in pharmacokinetics of e.g. torsemide and metoprolol were found to be much less between monozygotic as compared to dizygotic twins ( 26); only 30%-40% of the inheritable part of this variation was attributable to genetic variants known at that time. For more than half of the genes encoding drug metabolizing enzymes (other than CYP2C19 and CYP2D6) and drug transporters, rare variants account for the entire genetic variability ( 24). Therefore, the only robust manner to determine the true genetic variation of patients in a comprehensive manner, would appear to be the use of sequencing techniques, which is not realistic in most of clinical facilities. However, it is likely that a transition to more use of these will appear in the coming years and that this will yield more optimal tools to assist treatment personalization in psychiatry.

Sequencing-based analyses present various challenges. Firstly, many pharmacogenes represent complex loci, including several genes and/or pseudogenes with very similar sequences. Conventional NGS analyses with short overlapping reads are unable to determine the genotype in such cases, as sequence similarities with neighboring genes/pseudogenes renders alignment of short sequences to the gene(s) in question very difficult or impossible. Long read sequencing or synthetic long read methods have to be employed for such loci ( 27). Secondly, NGS based sequencing is not able to make a firm assignment of the functionality of mutations identified, with respect to loss of function mutations and true synonymous mutations. However, relatively accurate algorithms to predict the functionality of mutations have been developed and trained on DME genes ( 28); the analysis workflow using such sequencing-based techniques is depicted in Figure 1. In the future, the application of such a broad personalized approach for analyses of genetic variation could make pharmacogenomic predictions much more attainable for individual patients.

Figure 1 Scheme for NGS-based sequencing for determination of global genomic variations of importance for preemptive pharmacogenetics advice. Common variants might also be directly detected by using standard genotyping techniques and conventional sequencing. The gene of interest might have its origin in a complex locus like the CYP2D locus and for proper sequencing e.g. long range PCR methods are necessary. From the (NGS, common known mutations will be evident but also rare mutations. These can be classified by subjecting the sequences to specific algorithms that can classify the mutations according to expected functional impact.

Phenotypic Classification Based on CYP2C19 and CYP2D6 Genotype

The cumulative allelic frequency of all CYP2C19 and CYP2D6 alleles that influence enzymatic capacity varies by ethnicity, but it is always substantial (higher than 50%); therefore, the total number of affected patients is considerable. Traditional classification usually divides patients into four groups: ( 1) poor metabolizers (PMs) are homozygous carriers of two loss-of-function alleles and their specific enzymatic capacity is completely abolished; ( 2) intermediate metabolizers (IMs) carry genotypes that are causing substantially reduced, but not absent, enzyme capacity; ( 3) normal metabolizers NMs homozygously carry normal ( Wt) alleles and are associated with normal enzymatic capacity. NMs may also carry other genotypes as long as the enzymatic capacity is not significantly different compared with Wt/Wt carriers; ( 4) ultrarapid metabolizers (UM) carry genotypes linked to significantly increased enzymatic capacity compared with Wt/Wt carriers.

While this classification is informative and consistent with recent data, it is over-simplified, as certain genotypes that are classified within one category may carry different enzymatic capacities and the functional categorization of some specific genotypes is unclear ( Table 1). A potential solution is the establishment of activity scores that may be used to translate highly complex CYP2D6 or CYP2C19 diplotype data into one value, which can be used as the estimate for phenotypic alteration ( 29). However, the precision of such an activity score index would require very reliable estimates of how much each variant allele affects enzymatic capacity and the activity score may also be substrate dependent. Consequently, such a classification is very simple for Null alleles since they completely abolish enzymatic capacity (0% activity score compared with Wt allele), but quite complicated for the other functional alleles. According to our data from 2,087 CYP2C19 genotyped patients treated with escitalopram, the CYP2C19*17 allele increases the enzymatic capacity of CYP2C19 by only approximately 20% compared with CYP2C19Wt ( 15). Similarly, in our data from 1,003 CYP2D6 genotyped patients treated with venlafaxine, the CYP2D6*41 allele reduces the enzymatic capacity of CYP2D6 by approximately 85% compared to CYP2D6Wt, while CYP2D6*9 and CYP2D6*10 alleles reduce CYP2D6 enzymatic capacity by approximately 70% compared to CYP2D6Wt ( 22). Table 2 illustrates the metabolizer categorization and activity scores based on CYP2C19 and CYP2D6 genotypes; however, although these estimates are quite reasonable, the activity scores may also be drug- and ethnicity-dependent and more in vivo studies are needed to improve the trustworthiness of the activity scores.

While associations between functional diplotype category and expected enzymatic capacity are informative, the clinically relevant information is how CYP2C19 and CYP2D6 genotypes translate into phenotypes such as drug concentration, and whether genotypes are associated with differential treatment outcomes. It is expected that the occurrence of CYP2C19 and CYP2D6 variant alleles will affect the exposure of drugs metabolized by CYP2C19 and CYP2D6, and conversely, that drugs which are specifically metabolized by CYP2C19 or CYP2D6 will be mostly affected in terms of relevant clinical phenotypes. However, specific associations and the magnitudes of such effects have to be established and quantified accordingly.

Escitalopram and sertraline are examples of drugs that are metabolized predominantly by CYP2C19 and as expected, a profound increase in escitalopram and sertraline exposure is observed in CYP2C19 PMs ( 15, 30). Escitalopram treated PMs are more prone to side effects and treatment dropout ( 15, 31); however, they also respond better to escitalopram if treatment is tolerated ( 31, 32). The increase in enzymatic capacity caused by the CYP2C19*17 variant seems to also affect escitalopram treatment outcome, likely by reducing the exposure ( 15, 33). Patients carrying CYP2C19*1/*17 and CYP2C19*17/*17 genotype had a 50% increase in treatment failure rate compared with NMs ( 15). Moreover, replicated findings that CYP2C19 UMs treated with escitalopram exhibit increased suicidal ideation ( 34, 35) indicates that distinguishing between CYP2C19 NMs and UMs is clinically relevant for the escitalopram treatment.

Risperidone is an example of a drug that is metabolized predominantly by CYP2D6, and in a study of 1,288 patients, approximately 1.4- and 1.6-fold risperidone exposure increase was observed in IMs and PMs, respectively ( 14). Since the therapeutic window for risperidone is quite narrow, this exposure increase is likely the reason behind the higher incidence of risperidone-associated adverse drug reactions ( 36) and treatment failure ( 14) observed among PMs compared with NMs. Furthermore, an increased treatment failure rate is also observed in Ums ( 14), indicating that they might be exposed to insufficient drug levels. Many other antipsychotics, such as aripiprazole and haloperidol, are metabolized by CYP2D6. Although aripiprazole metabolism is not as CYP2D6 selective as that of risperidone, CYP2D6 genotype clearly affects drug exposure for aripiprazole: a 1.6-fold increased drug exposure is observed in CYP2D6 PMs in a study of 1,334 patients ( 14). Since aripiprazole has a very long half-life (almost a week), the net clinical effect is significant; hence, halving the aripiprazole dose is recommended on the FDA drug label for known CYP2D6 PMs (FDA Aripiprazole).

Translation of CYP2C19 and CYP2D6 Phenotypes Into Clinical Recommendations

It is not realistic to expect that clinicians are able to follow scientific literature on a regular basis in addition to their clinical work, and it is therefore essential to differentiate robust scientific evidence from the findings that need further validation and to translate the former into informative treatment guidelines. There is a research gap in knowledge regarding the cost-effectiveness of preemptive genotyping in psychiatry; however, it has previously been suggested that pharmacogenetic testing in psychiatry might be cost-effective if the tests became cheaper. Importantly, most of the models did not consider indirect costs, which are known to be high for psychiatric patients ( 37- 39). In the EU, the direct and indirect costs of mental health disorders have been estimated at €798 billion and are expected to double by 2030 ( 40). The cost of genetic testing is dropping each year, rendering its implementation in daily psychiatric care more and more possible.

In addition, utilization of the outputs from pharmacogenetic testing can be very challenging in the complex real-life situations ( 41). Patients often suffer from multiple disorders and are therefore taking combinations of medications, which can influence the metabolism of the CNS active drugs. This phenomenon causes the conversion of genetic EMs into phenotypic UMs, IMs, or PMs (phenoconversion) owing to the effects of concomitant medications on enzyme inhibition and induction and this can modify clinical response to drugs. This has mostly not been taken into account in clinical studies and there is a therefore a real risk that such studies may have missed clinically relevant phenomena.

Although the scientific evidence for the above mentioned CYP2C19 and CYP2D6 genes is strong enough to recommend clinical application, larger international and nonindustry-funded implementation studies demonstrating feasibility and cost-effectiveness in real-world settings are lacking. Real-world settings include people that use more than one drug, which is something that the current guidelines do not yet cover. Possible obstacles in terms of feasibility include the availability of an efficient system to generate, deliver and implement genotyping in the clinical prescription of psychiatric medication. At this time, despite gene-dosing advice for many antidepressants ( Tables 3 and 4) and antipsychotics ( Table 5) these are all prescribed to patients with almost no preemptive genotyping or genetic analyses during treatment, not even when side effects occur or when the pharmacotherapy is inefficacious.

Table 3 Dosing advice of antidepressants based on CYP2C19 and CYP2D6 phenotype according to DPWG and/orCPIC; see ( 77).

Table 4 Tricyclic antidepressants dosing advice based on CYP2C19 and CYP2D6 phenotype according to DPWG and/or CPIC; see ( 78).

Pharmacodynamic Pharmacogenetics

Research oriented towards pharmacodynamic-related biomarkers has to date mainly focused on functional variants of genes encoding drug targets for currently available antipsychotics and antidepressants such as SERT ( SLC6A4), NET ( SLC6A2), DRD2, HTR1A, and HTR2A. In addition, genes coding pivotal proteins involved in neuroprotection, stress-response and immune system activation such as BDNF, FKPB5, CHRBP, HLA-A, and HLA-B have been considered. However, despite initial enthusiasm, most of these polymorphisms have not yet been validated for clinical utility.

One example is a polymorphism in the promoter region of the serotonin transporter ( 5-HTTLPR), which is one of the most studied genetic polymorphisms for response to antidepressants. The deletion of a 44-bp long region gives rise to a short (S)/long (L) variant in the promoter region, the short having been associated with lower levels of SERT expression ( 42). The long (L) variant was initially associated with better response to SSRIs ( 43). After 28 studies were conducted to either validate or dismiss this finding, a recent systematic review was performed and according to the meta-analysis therein, this variant did not conclusively affect SSRI treatment outcome ( 44). Although it may nonetheless be possible that it is relevant together with other data( 45), at the present date, it is unlikely that 5-HTTLPR genotyping, which is present in more than one third of currently available commercially assays ( 13) can be utilized as an effective clinical predictor for drug response. Similarly, rs7997072 ( HTR2A) ( 46), rs5569 (SLC6A2) ( 47), and rs1360780 (FKBP5) ( 48) were suggested to be predictors of response to SSRIs, SNRIs, and all antidepressants admixed respectively with reasonable confidence levels and effect sizes. However, these findings were not replicated in a precise manner by the GENDEP study ( 49). For example, for the HTR2A, different markers (rs2224721 and rs9316233) in the same region of the gene (intron 2) as rs7997072 were nominally significantly associated with response to escitalopram in GENDEP study ( 49). It is likely that the effect of HTR2A polymorphism involves complex polygenic gene-environment interactions; however, these interactions are yet to be elucidated. A further example is the -141C Ins/Del polymorphism in the DRD2 gene, which in a GWAS was associated with risk of schizophrenia and was suggested to predict response to antipsychotic therapy ( 50); in addition, a recent report linked the minor allele with less favorable response to clozapine ( 51). However, the level of significance was only marginal ( p value between 0.05 and 0.01), suggesting that the clinical relevance of this SNP, when considered alone, is limited. Of note, CYP2C19 and CYP2D6 are both expressed in the human brain ( 52, 53), where they can metabolize trace amines to monoamines and affect psychiatric-relevant phenotypes and pharmacological treatment outcomes ( 54, 55). Substantial effort has been made to elucidate the endogenous role of these two enzymes in the brain and the impact of variant CYP2C19 and CYP2D6 alleles. However, it is not yet clear whether their endogenous role and local drug metabolism can affect treatment with psychiatric drugs. This topic however, is beyond the scope of this review; for further reading see ( 56) and. P-glycoprotein (P-gp) is a plasma membrane efflux pump encoded by the ABCB1 gene which acts as a drug transport mechanism, actively exporting drugs from cerebrospinal fluid to blood. Many psychiatric drugs are substrates for P-gp and functional polymorphism in ABCB1 might hypothetically change the levels of such drugs at the site of action; however, although certain variants of ABCB1 have been associated with alterations in drug disposition and response, the results have been highly conflicting, with questionable clinical relevance ( 57).

Other types of polymorphic loci, such as the HLA locus, can be used for prediction of drug response and adverse drug reactions. For example, the HLA-B*1502 allele is connected with an increased risk of developing Stevens-Johnson syndrome (SJS) and its related disease, toxic epidermal necrolysis (TEN) during carbamazepine or oxcarbazepine treatment ( 58). HLA-B*1502 is common among East Asians (6.9%, apart from Japanese at <1% and Korean at <2.5%); Oceanic (5.4%); and South/Central Asian (4.6%) ethnic groups have relatively high frequencies of HLA-B*1502 ( 58). Among carbamazepine treated patients, HLA-B*1502 increases the risk of SJS/TEN hundredfold (OR: 113.4; 95% CI: 51.2-251.0) ( 59). While the positive predictive value of HLA-B*1502 genotype is much less for oxcarbazepine then for carbamazepine, the negative predictive value for both is nearly 100% in South East Asian populations ( 60). In a trial of 4,877 patients in Taiwan, HLA-B*1502 genotyping completely prevented SJS/TEN from occurring, while the estimated historical incidence of carbamazepine-induced SJS-TEN (0.23%) would translate into approximately 10 cases among study subjects ( 61). As a result of this evidence, the FDA introduced a black-box warning on the carbamazepine drug label and proscribed mandatory genotyping for the HLA-B*1502 in patients with documented Asian origin ( https://www.accessdata.fda.gov/drugsatfda_docs/label/2009/016608s101,018281s048lbl.pdf). CPIC provides guidelines for HLA-B*1502 and HLA-A*31:01 variants for all carbamazepine and oxcarbazepine-treated patients, irrespective of region of origin or ethnic group ( 58). This example illustrates how drug labelling and clinical guidelines follow, once the clinical studies are able to provide firm and robust evidence about the usefulness of preemptive genotyping.

In the present situation, where commercial companies specialized in the sale of genetic test results for profit have proliferated, there is an increasing risk of advertisements relatied to offering nonvalidated pharmacodynamic- and pharmacokinetic-based genotypes directly to consumers (patients). In fact, for inadequately informed clinicians, such genetic testing may actually cause more harm than benefit. One of the examples that illustrates this possibility is a recently published case report describing a patient whose family and outpatient care provider received the information that he was a -141Cdel carrier. Since the genetic test results implied that the patient was expected to poorly respond to clozapine, objection was raised when switching the antipsychotic to clozapine was suggested to the patient. However, since the symptom level was severe, after consulting with the hospital medical director, clozapine was nonetheless administered to the patient and this had a remarkably good and rapid effect ( 62). As previously mentioned, the DRD2 -141C ins/del is very far from a validated biomarker for clozapine response and is seldom present on any of the commercially available assays ( 13). This case therefore illustrates the danger of testing using insufficiently validated genetic markers and provides an example of how such testing can cause a setback in the clinician-patient relationship. We therefore conclude that healthcare providers who order and deal with pharmacogenetic testing should have a moral and legal responsibility to educate themselves and their patients about pharmacogenetic testing and its limitations. Furthermore, regulatory and legislative frameworks should be developed and implemented to guide this process.

Discussion

The number of drugs carrying pharmacogenomic labels continues to increase ( 6, 63), while in contrast, the chance of discovering more blockbuster drugs is decreasing. Therefore the advancement of pharmacotherapy in psychiatry and in general in the forseeable future will likely be dependent on adequate drug treatment personalization ( 64). One example is the treatment of cystic fibrosis, where genotyping of the CFTR gene directly impacts the likelihood for successful treatment using CFTR modulators ( 65). Guidelines for pharmacogenomic work during drug development have been developed and are instrumental tools for the pharmaceutical industry ( https://www.ema.europa.eu/en/documents/scientific-guideline/guideline-good-pharmacogenomic-practice-first-version_en.pdf), particuarly in oncology.

With respect to psychiatry, the HLA markers described above are relevant for mood stabilizers carbamazepine and oxcarbamazepine. While genotyping to avoid life-threatening adverse drug reactions is mandatory for the HLA markers, pharmacoeconomic analyses provide support for the cost-effectiveness of other pharmacogenetic-based treatment decisions, especially in the case of CYP2D6 ( 66, 67). Currently, it seems evident that, out of many proposed markers, only genetic variants located in the CYP2C19 and CYP2D6 genes are of value for optimizing antipsychotic and antidepressant drug treatment. These genes were consistently found to influence pharmacotherapy response in seven randomized controlled trials when genotyping was performed prospectively ( 68- 74). While genotyping pharmacodynamic genes such as DRD2 is not at this time sufficiently supported by research results, it is possible that machine learning of multivariate data including pharmacokinetic and pharmacodynamic genes may produce associations of interest.

Variants in pharmacogenes often have low allele frequencies and thus for good power, thousands of patients, or meta-analyses in which variants are grouped together into functional categories, are required for robust results. While neuropsychopharmacogenomic clinical trials including a health economic component could strengthen the evidence for cost savings, in general there is a need for a larger, nonindustry sponsored prospective trials. For some gene-drug pairs, some might argue that the strength of the evidence is sufficient and that such a clinical trial might be unnecessary and unethical. For most of the drugs however, the situation is not quite clear and further large analyses are indicated; moreover, even for the validated drug-gene pairs, some would argue that clinical evidence are still incomplete ( 16). It is also possible that further retrospective analyses of relevant clinical trials already conducted, especially where cost-related data are available, could generate informative health economic data. Certainly, pharmacogenomic analyses should incorporate comprehensive genomic analysis (sequencing) and also carefully consider factors that may influence the findings, such as comedications and pathophysiolgical factors.

Therapeutic drug monitoring (TDM) of drug plasma levels has been used in psychiatry for a long time, in particular for tricyclic antidepressants, lithium, and clozapine. TDM captures all factors of interindividual variability in drug metabolism, while genotyping can offer only a solid prediction of patient metabolic capacity ( 19); however, genotyping is possible before drug treatment is initiated, whereas TDM can only be performed when the drug levels reach steady-state and when the patient is possibly already exposed to adverse drug reactions. Therefore, in an ideal constellation, a psychiatrist would take into consideration all available genetic, somatic, dietary and environmental parameters to make the best possible drug and dose selection at initiation of therapy for each individual patient, and once the drug levels reach steady-state, TDM would be utilized to ascertain whether such an educated decision was indeed optimal. Since the efficacy rate is only 30%-40% for antidepressants and antipsychotics ( 75, 76) despite TDM, there is clearly room for an improvement in approach.

Conclusion

To conclude, there are good pharmacogenetic clinical recommendations for a wide selection of psychopharmacological agents based on CYP2C19 and CYP2D6 functional diplotypes. In addition, recent adequately-powered studies (n > 1,000) have yielded more clinically useful information and support the clinical utility of preemptive pharmacogenomics for specific gene-drug pairs. To extend the knowledge beyond these gene-drug pairs, further large-scale prospective randomized trials having a sequencing-based genetic approach and/or reanalyses of studies with economic data are needed. At this point, there would appear to be sufficient data to support implementation of pharmacogenomics in to daily psychiatric practice in patients experiencing side effects and/or inefficacy ( Tables 1- 3). Finally, it is crucial that clinicians are adequately educated in the field of pharmacogenetics and equipped with adequate guidelines and decision support tools to interpret genotyping results and translate them into the clinical setting.

Author Contributions

RW drafted pharmacokinetics-clinical part. KA drafted the discussion KA and MJ drafted pharmacodynamics part. MI-S drafted the introduction and conclusion. MI-S and MJ drafted pharmacogenetics-genetics part. MJ drafted pharmacokinetics introduction part and pharmacokinetics-phenotypes part. All authors edited and approved all parts.

Funding

2017 Koers 2017/2018 Internal funding Erasmus MC to start Outpatient clinic Pharmacogenetics in Psychiatry, Instigator and PI to RW 2017 NL63514.019.17 Pharmacogenetics to improve personalized antidepressant dosing in patients with severe depression: a randomized controlled trial using tricyclic antidepressants. Co-applicant (PI ErasmusMC) to RvW 2016 Project 42653483 for a Dutch Guideline in Implementation of pharmacogenetics in psychiatry SKMS (Stichting Kwaliteitsgelden Medisch Specialisten), Instigator, and Chairperson to RW 2019 Phillip Morris grant - Utility of CYP2C19 genotyping and therapeutic drug monitoring in the personalization of escitalopram therapy to MJ.

Conflict of Interest

KA has received the AmpliChip CYP450 Test and associated research support from Roche Molecular Systems, and has acted in a consulting capacity for companies including Bristol-Myers Squibb and Otsuka Pharmaceuticals Ltd, Otsuka Canada Pharmaceuticals Inc., Lundbeck, and HLS Therapeutics. She has also received research grants from companies including Bristol-Myers Squibb and Otsuka Pharmaceuticals, Johnson and Johnson Research and Development, and Jannsen Inc. Canada. RW is a medical consultant at Chipsoft (Electronic patient files, Netherlands) and a founder of Outpatient Clinic Pharmacogenetics Parnassia Psychiatric Institute.

The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

The authors would like to thank Vasyl Yavorskyy, Michael Carr, and Beatriz Carvalho Henriques for their contributions to this review.

References

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# data[].attributes.attachment_link.title
Pharmacogenomics of Antidepressant and Antipsychotic Treatment: How Far Have We Got and Where Are We Going?

# data[].attributes.attachment_link.description
In recent decades, very few new psychiatric drugs have entered the market. Thus, improvement in the use of antidepressant and antipsychotic therapy has to focus mainly on enhanced and more personalized treatment with the currently available drugs. One important aspect of such individualization is emphasizing interindividual differences in genes relevant to treatment, an area that can be termed neuropsychopharmacogenomics.

# data[].attributes.headline
Vídeo Ilustrando a forma como anticorpos funcionam, são produzidos no corpo e como são produzidos na indústria  #anticorpos

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Vídeo Ilustrando a forma como anticorpos funcionam, são produzidos no corpo e como são produzidos na indústria  #anticorpos

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Olá, pessoal. Trouxe para vocês esse vídeo bem didático de como funciona a produção de anticorpos no corpo.

É um vídeo com uma didática bastante convidativa, e apesar de estar legendado em inglês, apresenta ilustrações que são fáceis de entender e de explicar.

O vídeo foca principalmente nos anticorpos monoclonais, e fala também sobre como eles podem ser produzidos em escala. É um vídeo explicativo da Nature vídeo.

Espero que gostem!

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#drugdiscovery Pesquisa relacionada à aprendizagem de desequilíbrio de classe com otimização Bayesiana aplicada em drug discovery

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#drugdiscovery Pesquisa relacionada à aprendizagem de desequilíbrio de classe com otimização Bayesiana aplicada em drug discovery

# data[].attributes.body
Inteligência de máquina, incluindo aprendizado de máquina e aprendizado profundo, têm sido considerados métodos promissores para reduzir o custo proibitivamente alto do desenvolvimento de medicamentos. Portanto, é proposto um pipeline chamado Class Imbalance Learning with Bayesian Optimization (CILBO) para melhorar o desempenho de modelos de aprendizado de máquina em drug discovery.

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Introduction

Drug development is a costly process that takes more than 10 years and up to an average of 2.6 billion USD to bring a drug from preliminary discovery to the market1,2,3,4,5. Much of this cost is attributed to the high attrition rate of the failure trials of the candidate drugs3,4. Despite substantial investment in the selection of candidate molecules from hundreds or thousands of compounds, the success rate for new candidates to finally reach the market is approximately 10%4. Therefore, selecting the most promising candidate molecules will help to accelerate the research process and reduce final stage failure, thereby minimizing the cost of drug development.

Machine intelligence (MI), including machine learning and deep learning, has been successfully applied to drug discovery and is regarded as a promising method for such candidate selection6,7. However, there is a dilemma between performance and interpretability within MI8, which has limited its application. Previous studies have shown that deep learning models perform better than machine learning models on classifications9,10 but are harder to interpret11. The reason deep learning models are more difficult to interpret is that it is harder to find direct and reliable correlations between features the models utilized in classification and the output predictions11. These limitations are unfavourable in drug development because researchers in the field would prefer to acquire not only the capacity for prediction but also the knowledge suggested by the model12.

Developing methods to interpret the outcomes of deep learning models is no simple task12,13,14. Instead, improving the performance of machine learning models may offer a faster and easier solution to alleviate the dilemma of predictivity and interpretability. For instance, automatic machine learning (AutoML) is one promising strategy to enhance the drug development process.

Models built on automatic machine learning have been verified in healthcare to have relatively good performance15,16. Even the deep learning model's performance sometimes relies on the network structure suggested by automatic machine learning10. Under the AutoML algorithm, various hyperparameters or ensemble methods can be automatically tried tens to hundreds of times to improve the performance of the machine learning model. Meanwhile, the AutoML algorithm frees the researcher from these tedious, and repetitive trial and error as well17. Besides, training a machine learning model generally takes orders of magnitude less time than training a deep learning model. Machine learning models built on AutoML can be easily trained with many more hyperparameters in an acceptable training time.

Additionally, drug discovery datasets are usually highly imbalanced, that contain very few functional candidates (interested class) and hundreds or thousands of times more unfunctional molecules (uninterested class)18,19. The minority interested class is more likely to be predicted as a rare occurrence, ignored altogether, or assumed as noise or an outlier, which causes bias and leads to poor generalization performance20. Although several previous studies in disease and drug related fields proved that addressing class imbalance problem appropriately would improve the model's performance21,22,23, this problem has still been frequently ignored. Once the machine learning models apply strategies to minimize classification bias caused by the imbalanced datasets, it may further benefit the performance improved by the AutoML algorithm.

Therefore, we suggest a pipeline of constructing a machine learning model using Bayesian Optimization with strategies for imbalanced datasets to improve the classification performance of this model on drug discovery. In this pipeline, the best hyperparameter combination of the model variables, training and treating imbalanced datasets is suggested with Bayesian optimization. Bayesian optimization is a sequential design strategy for global optimization of black-box functions that does not assume any functional forms, and it seems particularly well-positioned for the application areas like drug development24,25. The optimization used here differs from commonly used hyperparameter optimization by addressing the issue of class imbalance. We call this pipeline Class Imbalance Learning with Bayesian optimization (CILBO). Antibiotic predictions are used here as an example to evaluate the effectiveness of this pipeline.

In the past decades, antibiotic screening has become prohibitively costly and has decreased dramatically10,26,27,28,29. This situation, together with widespread antibiotic resistance, makes the discovery of new antibiotics critical10,26,30. A recent work done by Stokes et al. showed the successful discovery of new antibiotics through the combination of a graph neural network (GNN) model prediction and empirical investigation10. Stokes' research highlighted the significant impact of deep learning on early antibiotic discovery, but interpreting the results generated by their model is still not an easy task.

Here, using the same datasets described in the paper by Stokes et al.10, we generated a random forest classifier with CILBO and compared the predictions of our model to those of Stokes' model10. The comparison suggests that our machine learning model can perform predictions as well as the deep learning model. The CILBO pipeline is simple to run and able to efficiently improve the performance of machine learning models, offering an alternative approach that can be widely applied in many fields of drug discovery.

Results

Summary of our example model construction

To improve the classification performance of the easy-to-interpret machine learning models on drug discovery, we built a pipeline called Class Imbalance Learning with Bayesian Optimization (CILBO). This pipeline uses Bayesian optimization to suggest the best combination of hyperparameters for model variables, training, and treating imbalanced datasets of a machine learning model. We constructed a random forest classifier based on CILBO as an example to verify CILBO's effectiveness on improving model performance in drug discovery (Fig. 1).

Workflow of the final model construction.

Evaluation of our model performance during the training phase

We trained our model on the same datasets used in Stokes' GNN model10. The dataset used for training contained 2335 molecules, but only 120 of them had proved antibacterial activity (see Supplementary Table S1). The dataset was highly imbalanced. To compare the performance and outcomes of our model with Stokes' deep learning model, we used the same training dataset and training/testing ratio (see " Methods " section).

The best hyperparameters suggested by Bayesian optimization, which were used in this study, are listed in Table 1. The last two hyperparameters, "class_weight" and "sampling_strategy" were utilized to minimize the bias caused by dataset imbalance and enhance the overall model performance. The feature "fingerprint" providing the descriptions of the topological structure representations was very useful for interpreting the model. The RDK fingerprint computed by RDKit31 was selected as the molecule feature for our model because it behaved optimally compared to other optional features (for descriptors and other fingerprints, see " Methods " section).

Table 1 Best hyperparameters suggested by Bayesian optimization.

With these best hyperparameters and feature, the average receiver operating characteristic curve-area under the curve (ROC-AUC) of our model, after 30 times fivefold cross-validation at the training phase, was about 0.917 ( Supplementary File random_forest_antibiotic_20210511c.py). It was greater than 0.896, by the ROC-AUC of Stokes' model10. After being enhanced by the best hyperparameters and molecule features described above, and with more training samples (the training set includes 90% of molecules), our final model achieved a ROC-AUC of 0.99 (Fig. 2). The confusion matrix based on the test set of our final model is shown in Table 2. According to this matrix, our model did not classify any non-antibacterial molecules as antibacterial, which suggests that the model has a low false-positive rate for identifying candidate compounds.

ROC-AUC of our final model.

Table 2 Confusion matrix of our final model.

Comparison of the prediction results generated by our model and Stokes' model in antibacterial discovery

Our final model was then applied to identify candidate molecules with antibacterial characteristics from the library recorded by the Drug Repurposing Hub10,32. This library contained 6111 molecules at different stages of investigation for human diseases. After removing compounds with molecular graphs common between the training dataset (2335 molecules) and the Drug Repurposing Hub (6111 molecules), a dataset containing 4496 unique molecules was used for the identification. Importantly, this dataset was also the same set of molecules used by Stokes et al. to demonstrate their model10. For each molecule, our model provides a prediction score. The full list of prediction results can be found in Supplementary Table S2.

Using their model, Stokes and his colleagues selected the top 99 molecules most strongly predicted to display antibacterial properties, along with the 63 molecules with the lowest prediction scores. To validate this finding, Stokes et al. empirically tested these 162 (99 + 63) molecules10. We leveraged Stokes' empirically tested antibacterial information to estimate our own prediction results across the same set of 162 molecules (Supplementary Table S3). We found that our model was comparably effective as the Stokes' model in its prediction of the 162 molecules with antibacterial properties. (Fig. 3).

Plot of the prediction results by both models. Plot of the 162 molecules with empirically tested antibacterial information and also predicted with top and bottom scores respectively for antibacterial properties by Stokes' model10. Blue dots represent non-antibacterials; orange dots represent antibacterials. X-axis (Pred_Score_Forest) is the score predicted by our final model, a random forest classifier; Y-axis (Pred_Score_Net) is the score predicted by Stokes' final model10, a graph neural network.

Specifically, about 75% of the molecules with prediction scores above 0.5 in our model (model default threshold score) were found to be empirically tested antibacterials, while 74% of the molecules with prediction scores above 0.5 in the Stokes' model were empirically tested antibacterials. When a threshold score above 0.5 was selected in both models, about 80% of molecules meeting the criteria had empirically tested antibacterial properties, which was higher than the number by any model alone. If requires 90% of the empirically tested antibacterial molecules were screened out, the score threshold of our model and Stokes's model would be 0.15 and 0.3 respectively based on this comparison (Fig. 3). Of the molecules that scored near zero, almost all were absent of antibacterial properties in both models. Again, this finding further emphasizes that our model is comparable with the Stokes' model in its prediction capacity.

Discussion

Machine Intelligence (MI) has been regarded as a promising approach to help relieve the pressure of prohibitively costly procedures during drug discovery. However, the dilemma between predictivity and interpretability within MI has limited broader applications in drug discovery. Therefore, we suggested a pipeline Class Imbalance learning with Bayesian Optimization (CILBO) to improve the machine learning model's classification performance.

We verified the performance of an example model built based on CILBO for candidate antibiotic discovery. Here, a random forest classifier constructed using Bayesian optimization with strategies for imbalanced datasets was applied as the example model. The random forest classifier was adopted because it limits overfitting and is easy to interpret.

By using the same datasets and similar training conditions described in Stokes' paper10 (see " Methods" section), our model was comparable to Stokes' model. Based on the same splitting ratio of training and testing sets, the average ROC-AUC of our model could reach 0.917, which is notably higher than 0.896 the ROC-AUC of Stokes' model. Meanwhile, the results of imbalanced random forest model with empirical hyperparameters and xgboost were also compared with our model, and the average ROC-AUC calculated based on them were 0.895 and 0.901 respectively (see the Supplementary File "machine_learning_model_20211208.py"). This finding indicates that the performance of our model is not inferior to that of Stokes' deep learning model10 based on the comparatively simple library we used for training.

When directly comparing the prediction results of two models among the 162 empirically tested molecules, our model also successfully captured promising candidates at a rate comparable to Stokes' deep learning model. These results all suggest that our model can perform as well as deep learning models in early screenings for drug discovery.

A key natural benefit of the CILBO model is that it is easy to interpret. Furthermore, the time required to train a machine learning model like the random forest model used here is at least 100 times shorter than the time required to train a deep learning model. It provides enough time to try various hyperparameters automatically and identify the best ones to enhance the model. Another obvious advantage of the model built on CILBO compared to the normal deep learning model is that CILBO is less dependent on the model designer and infrastructure. To design a neural network model, the researcher needs a rich experience and a high-end machine. The random forest model is simpler to design since the key characters are provided by Bayesian optimization, an AutoML method. Therefore, the simplicity and efficiency of our model will make it applicable in a wider context of drug candidate selection.

Of particular note is that imbalanced datasets are fairly common in the drug industry. They may cause severe classification bias during MI aided drug development, but this problem has been frequently ignored. We considered this imbalance problem in the construction of our model and used special hyperparameters to control for this type of bias. It is designed to enhance the performance of our model.

In our work, we constructed a special random forest model using CILBO (a pipeline we proposed), and compared this machine learning model to the deep learning model created by Stokes et al.10 in antibiotic discovery. The comparison results together with other properties of our model suggest that: (1) the machine learning model built on CILBO can perform prediction at least as well as the deep learning model; (2) it is naturally easier to interpret and comparatively simpler to operate without requiring a high level of researcher experience, (3) inclusion of strategies for class imbalance to control classification bias further improved the predictive performance of the model built on CILBO, and may broaden its applicability in drug development. Therefore, CILBO, the pipeline we designed provides an alternative and simple solution to promote MI in drug development.

Methods

Model selection

We used a random forest model as the classifier in this work (Fig. 1). A random forest model is robust against overfitting33 and easy to interpret because routine methods can be used to estimate the importance of and interaction between features34.

Molecule feature selection

The optional molecule features include descriptors, RDK fingerprint, MACCS key, Avalon fingerprint, ECFP4 and ECFP6, which were calculated by RDKit 2020.09.1.031. All of these features were tested separately during the training phase of our model, but not the complex combination of features. Descriptors usually provide information on different molecular properties, such as general physical properties, electrochemical properties and electron cloud characteristics. Fingerprint provides descriptions of various topological structure representations of molecules. RDK fingerprint was chosen for the final model. RDK fingerprint calculated for the dataset used to train our model (including 2335 unique compounds) and the dataset used to predict candidates (including 4496 unique compounds) can see in Tables S4 and S5 respectively.

Hyperparameters optimization

Bayesian optimization was used to find the best hyperparameters to our model. In this work, Bayesian optimization was used not just for the classifier, but also for the strategies specially dealing with imbalanced datasets. As we observed, the training dataset was highly imbalanced, which may introduce classification bias. Bayesian optimization was supposed to give the best combination of hyperparameters for the classifier and to mitigate the problem caused by class imbalance. This is distinct from common models using an automatic machine learning algorithm. In most cases, only classifier hyperparameters and training details of the models are focused, while strategies to deal with imbalanced datasets are frequently ignored.

Specifically, Python packages, scikit-learn 0.23.2, imbalanced-learn 0.7.0 and scikit-optimize 0.8.1 were used to search for the best hyperparameters. For convenience, the BalancedRandomForestClassifier defined in imbalanced-learn 0.7.0 package was adopted, since it included the sampling strategy and class weight. In our model, the maximum feature number was the default value in BalancedRandomForestClassifier. The hyperparameters that needed to be optimized were as follows:

Hyperparameters

Value type (range)

n_estimators

Integer (5, 5000)

Criterion

Categorical (["gini", "entropy"])

max_depth

Integer (1, 6000)

min_samples_split

Integer (2, 200)

min_samples_leaf

Integer (1, 200)

Bootstrap

Categorical ([True, False])

class_weight

Categorical (["balanced", "balanced_subsample", None])

sampling_strategy

Categorical (['majority', 'not minority', 'not majority'])

The hyperparameters most frequently used in random forest models included: "n_estimators", "criterion", "max_depth", "min_samples_split", "min_samples_leaf" and "bootstrap". The last two hyperparameters, "class_weight" and "sampling_strategy", were specifically used to handle imbalanced datasets.

In Bayesian searching, the ROC-AUC was the metric used for the random forest classifier. BayesSearchCV from the package scikit-optimize was the function for Bayesian searching, and the surrogate model was used by default. The cross-validation folds were created by StratifiedFold in scikit-learn package. The splitting number was set to 5 and the iteration number was 150. These numbers were set according to the relative description in Stokes' paper10 for a better comparison. Once the best hyperparameters were identified, an additional cross validation was performed. The final model was then trained with the best hyperparameters suggested by Bayesian optimization.

Datasets for training, analysis and direct comparison

The dataset used to train our model was the same dataset described in Stokes' paper10. This dataset combined the molecules from the USFDA-approved Drug Library and those isolated from natural products. It contained 2335 unique compounds, 120 of which had growth inhibitory activity against E. coli (see Supplementary Table S1). The dataset was highly imbalanced. For a fair comparison, the splitting ratio of training and testing sets used in our model were the same as the Stokes model10. It was about 80%/20% (training/testing) for the cross validation, and approximately 90%/10% for the final model training.

The dataset we used for candidate prediction was also the same dataset described by Stokes'10. It was a dataset from Drug Repurposing Hub10,32 containing 6111 molecules at various stages of investigation for human diseases. By removing the compounds with molecule graphs common between the training set and the Drug Repurposing Hub, the remaining 4496 molecules were used for both our model and Stokes' model prediction (see Supplementary Table S2). Of these molecules, 99 were predicted the most effectively and 63 were predicted the most ineffectively by the Stokes deep learning model (see Supplementary Table S3). These 162 (99 + 63) molecules were empirically tested for growth inhibition against E. coli by Stokes and his colleagues, and 53 (51 out of 99 and 2 out of 63) of them were found to have antibacterial properties.

The dataset used for direct comparison of prediction results between our model and Stokes' model was based on the 162 molecules with empirically tested antibacterial information.

Author information

Affiliations

Shanghai GenomSeqCare Biotechnology Co. Ltd., Shanghai, 200052, China

Shenmin Guan & Ning Fu

Contributions

S.G. conceived of the presented idea. S.G. developed the method and performed all the computations and analyses. N.F. helped with result presenting and discussion. N.F. drafted the manuscript. S.G. and N.F. revised the manuscript.

Corresponding author

Correspondence to Shenmin Guan.

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The authors declare no competing interests.

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Guan, S., Fu, N. Class imbalance learning with Bayesian optimization applied in drug discovery. Sci Rep 12, 2069 (2022). https://doi.org/10.1038/s41598-022-05717-7
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DOI: https://doi.org/10.1038/s41598-022-05717-7

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Sofi Imtiyaz Ali , Wajid Mohammad Sheikh , Muzafar Ahmad Rather , Venugopalan Venkatesalu , Showkeen Muzamil Bashir , Showkat Ul Nabi ,

Corresponding Author

Showkat Ul Nabi

Large Animal Diagnostic Laboratory, Department of Clinical Veterinary Medicine, Ethics & Jurisprudence, Faculty of Veterinary Sciences and Animal Husbandry, SKUAST-K, Srinagar, India
Correspondence
Showkeen Muzamil Bashir, Biochemistry & Molecular Biology Lab, Division of Veterinary Biochemistry, F.V.Sc. & A.H, Shuhama, Alusteng, Srinagar-190006, Jammu & Kashmir, India.

Email: showkeen@skuastkashmir.ac.in

Showkat Ul Nabi, Large Animal Diagnostic Laboratory, Department of Clinical Veterinary Medicine, Ethics & Jurisprudence, F.V.Sc. & A.H, SKUASTt-K, Shuhama, Alusteng, Srinagar-190006, Jammu & Kashmir, India.

Email: showkatnabi@gmail.com
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Corresponding Author

Showkeen Muzamil Bashir

Biochemistry & Molecular Biology Lab, Division of veterinary Biochemistry, Faculty of Veterinary Sciences and Animal Husbandry, SKUAST-K, Srinagar, India
Correspondence
Showkeen Muzamil Bashir, Biochemistry & Molecular Biology Lab, Division of Veterinary Biochemistry, F.V.Sc. & A.H, Shuhama, Alusteng, Srinagar-190006, Jammu & Kashmir, India.

Email: showkeen@skuastkashmir.ac.in

Showkat Ul Nabi, Large Animal Diagnostic Laboratory, Department of Clinical Veterinary Medicine, Ethics & Jurisprudence, F.V.Sc. & A.H, SKUASTt-K, Shuhama, Alusteng, Srinagar-190006, Jammu & Kashmir, India.

Email: showkatnabi@gmail.com
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Venugopalan Venkatesalu

Department of Botany, Annamalai University, Annamalainagar, India
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Muzafar Ahmad Rather

Biochemistry & Molecular Biology Lab, Division of veterinary Biochemistry, Faculty of Veterinary Sciences and Animal Husbandry, SKUAST-K, Srinagar, India
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Wajid Mohammad Sheikh

Biochemistry & Molecular Biology Lab, Division of veterinary Biochemistry, Faculty of Veterinary Sciences and Animal Husbandry, SKUAST-K, Srinagar, India
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Sofi Imtiyaz Ali

Biochemistry & Molecular Biology Lab, Division of veterinary Biochemistry, Faculty of Veterinary Sciences and Animal Husbandry, SKUAST-K, Srinagar, India
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Abstract

The pandemic of viral diseases like novel coronavirus (2019-nCoV) prompted the scientific world to examine antiviral bioactive compounds rather than nucleic acid analogous, protease inhibitors, or other toxic synthetic molecules. The emerging viral infections significantly associated with 2019-nCoV have challenged humanity's survival. Further, there is a constant emergence of new resistant viral strains that demand novel antiviral agents with fewer side effects and cell toxicity. Despite significant progress made in immunization and regenerative medicine, numerous viruses still lack prophylactic vaccines and specific antiviral treatments that are so often influenced by the generation of viral escape mutants. Of importance, medicinal herbs offer a wide variety of therapeutic antiviral chemotypes that can inhibit viral replication by preventing viral adsorption, adhering to cell receptors, inhibiting virus penetration in the host cell, and competing for pathways of activation of intracellular signals. The present review will comprehensively summarize the promising antiviral activities of medicinal plants and their bioactive molecules. Furthermore, it will elucidate their mechanism of action and possible implications in the treatment/prevention of viral diseases even when their mechanism of action is not fully understood, which could serve as the base for the future development of novel or complementary antiviral treatments.

1 INTRODUCTION

Among all the numerous outbreaks of infectious diseases confronted by humankind, it's indeed the viral infections that are undoubtedly the biggest pandemic threat in the recent era. The replication patterns and viral modes of transmission are the main determinants underpinning this assault. A wide-spectrum antiviral agent's inadequacy plays a pivotal role (Center for Health Security, ). Viruses need to use host cell machines for several functions. Therefore, their obligatory parasitic nature and antiviral approaches must be applied directly to a virus to minimize interference with the host cell functions (Adalja & Inglesby, ).

Further, the virus acts as barriers to broad-spectrum antiviral agents, including distinctions among RNA and DNA viruses, completely distinct virally encoded proteins, single or double genomic structure, cycles of cytoplasmic or nuclear replication, and degree of dependence on host proteins (Schoeman & Fielding, ). The global antiviral drug armamentarium is expanding exponentially and is now covering many viral families. Nonetheless, very few known antiviral agents have activity spectrums that even marginally match up to the penicillin or sulfa range, the very first antibacterial agents identified.

The Earth's planet constitutes approximately 1,031 viruses, and their pervasiveness has colonized the marine ecosystem, where about 5,000 viral genomes seem to be prevalent in every 200 L of water (Breitbart & Rohwer, ). Also, viruses continue moving between the environments. They are available worldwide, for example, in deep Ocean, polar ices, alkaline, hot, and salt waters, and are about 2,000 m deep in the terrestrial ecosystem. There have been nearly 20 families of viruses that certainly infect humans (Harvey, Champe, Fisher, & Strohl, ), and many of them also trigger diseases in animals (Mahzounieh, Moghtadaei, & Zahraei Salehi, ). Virus particles contact the living system, and if they inundate the human immune response, then preventing their expansion in the body would be almost unfeasible. For the sake of their frequent replication, they control the host biochemical pathway/metabolic processes and make their treatment almost tricky. However, it is now well comprehended that viruses are specific in their replication mode that could be effectively approached (Syed, Amako, & Siddiqui, ). For instance, the proteolytic enzyme enhances viral maturation by distinguishing the viral polyprotein predecessor, whose obstruction would prevent its growth (Wapling, Srivastava, Shehu-Xhilaga, & Tachedjian, ). The epidemic outbreaks caused by emerging and re-emerging viruses represent a critical threat to public health, mainly when preventive vaccines and antiviral therapies are unavailable. Several hard-to-cure diseases and complex syndromes, including Alzheimer's disease, type 1 diabetes, and hepatocellular carcinoma (HCC), have also been associated with viral infection (M. J. Ball, Lukiw, Kammerman, & Hill, ; Hober et al., ; Morgan et al., ). However, many viruses remain without adequate immunization and, only a few antiviral drugs are licensed for clinical practice. The situation is further exacerbated by drug-resistant mutants' especially when using viral enzyme-specific inhibitors, which significantly hampers drug efficacy (Geretti, Armenia, & Ceccherini, ; Locarnini & Yuen, ). Hence, there is an urgent need to discover novel antivirals that are highly productive and cost-effective for managing and controlling viral infections when vaccines and standard therapies lack.

New viral infections needed quite advanced drug molecules; however, the process of establishing such approaches toward this moment seems to have been sluggish and filled with impediments (Desselberg, ). Antiviral chemotherapy has proceeded at a snail-like pace, unlike antibiotics that had attained a specific treatment level in three decades. Nevertheless, it ended up taking nearly 60 years for antiviral development to achieve its current prevalence position. The evolution of diagnosis for Hepatitis C is a prime illustration of how complicated the antiviral effect can be. However, cumulative and aimed antiviral therapy has proven to be an excellent strategy for treating viral infectious disease.

Viruses are amongst the substantial causes of mortality and morbidity globally (GBD 2017 Disease and Injury Incidence and Prevalence Collaborators, ; WHO, ). Antiviral drugs and vaccines are being used to control human viral infections (De Clercq & Li, ). Eventually, the main focus was on "one drug, one virus" dogma, which depends solely on targeting virus-specific factors. A counterstatement to this is "one drug multiple viruses" (BSAAs), as viruses utilize similar pathways and host factors to replicate within a cell (Bekerman & Einav, ; Bosl et al., ; de Clercq & Montgomery, ; De bing, Neyts, & Delang, ; Ianevski, Andersen, Merits, Bjoras, & Kainov, ; Rada & Dragun, 1977; Sidwell et al., ). Though the concept of BSAAs was about 50 years ago, due to the recent outbreaks of a novel coronavirus (2019-nCoV) and several other viral infections, the field has acquired new urgency for the discovery of novel host-directed agents and the expansion of a drug repositioning methodology (Paraskevis et al., ).

Drug repurposing, also known as repositioning, redirecting, reprofiling, is a strategic approach for accumulating additional benefits from an approved drug by approaching a disease apart from that it was initially envisioned (Nishimura & Hara, ; Pushpakom et al., ). It has distinct advantages over new drug discovery since chemical synthesis, manufacturing processes, reliable safety, and pharmacokinetic properties are accessible in pre-clinical and early clinical development phases. Consequently, the repositioning of launched or perhaps failed viral drugs offer incredible translational opportunities, such as a substantially higher probability of commercial success in comparison to the implementation of novel virus-specific medicines and vaccines and a substantially decreased cost and timeframe for clinical accessibility (Ianevski et al., ; Pizzorno, Padey, Terrier, & Rosa-Calatrava, ; Zheng, Sun, & Simeonov, ).

Antivirals are antimicrobial compounds derived from living organisms or generated by chemical synthesis, mostly hindering viral replication. Antivirals tamper with one or more phases of the viral life cycle, which include: cell attachment, cell penetration, viral uncoating, copy of the viral genome (DNA/RNA), maturation, and reveal of viral progeny and, are an essential tool to facilitate vaccine action (Veiga-Crespo, Viñas, & Villa, ). The synthesized antiviral drugs such as moroxydine, ganciclovir, valganciclovir, and valaciclovir were used to inhibit virus replication through various mechanisms (Biron, ). However, due to their low efficacy, cytotoxicity, and the development of viral resistance, difficulties in treating drugs arise. A further antiviral therapy, vaccination, may be used but is still under advancement because it often provides inadequate virus protection, and its validity needs further investigation (Subbarao & Joseph, ). Thus, more scientific research is required in the treatment of antiviral synthetic drugs and vaccines.

Nature has provided yet another credible source of antiviral agents, and almost 40% of the drugs available at the moment are directly or indirectly plant derivatives. A range of ethnobotanical studies focused on identifying possible therapeutic plants for even more effective management of healthcare issues, demonstrating the significance of medicinal plants in the healthcare deliveray system (Ansari & Inamdar, ; Appidi, Grierson, & Afolayan, ; Heneidy & Bidak, ; Ky et al., ; Makambila-Koubemba, Mbatchi, Ardid, Gelot, & Henrion, ; Shinwari & Khan, 2000). Herbal remedies and extracted natural products often provide a significant source of novel antiviral developing drugs. Antiviral medications' characterization from such natural sources sheds light on where they interrelate with the viral replication cycle, like viral entry, replication, assembly, and release, and the targeting of precise virus-host interactions. Here, we enumerate the antiviral activities of a range of natural products and herbal medicines against specific critical viral pathogens. This study aims to assess previously published antiviral plants and spot possible action mechanisms and substances accountable for their antiviral activity. A deeper understanding of the mode of action and evaluating the concerned compounds will provide a unique insight into the concept of new antiviral drugs for even more effective viral co-operation.

2 METHODOLOGY

An extensive review of the literature was carried out on antiviral medicinal plants and their associated bioactive compounds between 2019 and 2020 via electronic search Pubmed, Scopus, Web of Science, Science Direct, J-Gate, Google Scholar, and a library search for articles published in peer-reviewed journals. The unpublished materials have been excluded from this review. The review process was further continued by the refining of the search results using the keywords namely viral medicinal plants, antiviral bioactive compounds, emerging viral infections, novel coronavirus, coxsackievirus (CV), dengue virus (DENV), enterovirus 71, human herpes viruses, hepatitis virus, human immunodeficiency virus, influenza virus, measles virus (MV), respiratory syncytial virus (RSV), and rotavirus. The literature cited in the review dated from 1950 to 2020 and limited to the English language. The final data collected through the authors' discussions were then compiled, evaluated, compared, and drawn accordingly.

3 BASIC VIRAL STRUCTURE AND ITS PATHOBIOLOGY

Viruses are organic artifacts that are metabolically inactive outside the host and after accessing the host cell becomes activated (Dupre & O'Malley, ). They are comprised primarily of proteins and nucleic acid; the proteins contribute to their unique shape by forming a capsid (Andersson, ). Therefore, viruses are of different forms, like superficial, helical, icosahedral, or complex, and perhaps some viruses are accompanied by a lipid bilayer extrapolated from a host membrane called an envelope (Geng et al., ). Besides, capsid proteins associated with nucleic acids form nucleocapsids. Proteins related to viral nucleic acids are called nucleoproteins. Virus nucleic acid is either DNA or RNA and has been the elementary source of knowledge required to monitor its metabolic functions. This DNA and RNA are categorized based on the number of strands into single or double-stranded DNA/RNA (Firth et al., ; Pichlmair et al., ). The sense of strand can further differentiate single-stranded RNA viruses as some RNA viruses have a positive-sense RNA (+ve ssRNA), and some viruses have a negative-sense RNA (−ve ssRNA) (Gorbalenya, Enjuanes, Ziebuhr, & Snijder, ). Nucleic acid form (DNA/RNA) is indeed a vital point of differentiation since all viruses did not constitute the same nucleic acid pattern (Gao & Hu, ).

The multiplication of all viruses results from several sequential processes: adhesion of the virus to the cell surface, virus adsorption and entry into the cell, replication of viral nucleic acids, and expression of viral proteins, and release of virus particles from the cell. For example, the virus entrance process is often carried out by cell surface proteins; Hepatitis C virus (HCV) entry involves claudin-1, occludin, and tetraspanins as the primary receptor proteins (Burlone & Budkowska, ). The latter's accession is influenced by other lipoproteins and the enzyme lipoprotein lipase. Moreover, infection with the influenza virus is modulated by a protease enzyme that triggers the viral surface protein hemagglutinin (Zambon, ). The protease enzyme is pertinent for illustrating viral proteins; it categorizes proteins into groups based on everyone's structural and non-structural features (Appel, Schaller, Penin, & Bartenschlager, ). But RNA viruses require two powerful enzymes to sustain; reverse transcriptase and integrase, former transcribed viral RNA to DNA at the moment of replication (Briones, Dobard, & Chow, ; Sluis-Cremer & Tachedjian, ). In contrast, the second enzyme integrates viral DNA into the host genome and is required for the effective uncoating of virus-core proteins. As a result, the virus needs enzymatic and non-enzymatic proteins to stop its replication and infection.

4 ANTIVIRAL MOLECULES OF PLANT ORIGIN

Conventional medicine is indeed a worthwhile line of study for analyzing, extracting, and developing medicinal benefits. Conversely, a relatively small proportion of bioactive compounds were studied systematically for their therapeutic uses. Natural products include an unusual approach to exploring antiviral agents with remarkable pharmacological properties (Cragg & Newman, ; Atanasov et al., ). Herbal therapists have been using traditional plants since prehistoric days to cure diseases in humans and animals, particularly in the Asia-Pacific region. People continue to rely on medicinal herbs and their products for their wellness and primary medical care throughout the globe (Ekor, ). About 2,500 natural plant species are listed globally to diagnose many diseases and illnesses (Kapoor, Sharma, & Kanwar, ).

Collecting traditional data from local or indigenous communities or even using important ethnopharmacology plant(s) to extract bioactive molecules/phytochemicals is a very demanding approach for diagnosing different ailments (Altemimi, Lakhssassi, Baharlouei, Watson, & Lightfoot, ). Numerous aspects, including the various solvents (polar, non-polar) used during the extraction of bioactive constituents and the selection of plant parts/tissue for their extraction from plants, commonly play a crucial role (Ben-Shabat, Yarmolinsky, Porat, & Dahan, ). A holistic approach for isolating and characterizing bioactive molecules and virus replication inhibitory experiments in animal cell systems is required when such bioactive molecules could be used to cure a viral infection (Kapoor et al., ). The eternal objective of establishing high throughput screening assays is just the way to recognize bioactive molecules/phytochemicals from large chemical libraries quickly and accurately. In vivo experiments and consequent clinical studies are necessary to identify the antiviral activity and severe complications like reactogenicity or toxicity of purified bioactive molecules.

4.1 Coronavirus and medicinal plants

There have been no specific treatments for CoV infection, and preventive vaccines are still under examination. It illustrates the need to implement new antivirals for prophylaxis and treatment of CoV infection. The complete list of the potent plant extracts and their bioactive compounds that inhibit coronavirus are depicted in Table 1. Ginsenoside Rb1 (Gynosaponin C), one of the bioactive ginsenosides extrapolated from Panax ginseng, displayed antiviral activity (Wu et al., ). Tetra-O-galloyl-beta-d-glucose, luteolin, and tetra-O-galloyl-beta-d-glucose, blocked the SARS-CoV host cell entry (Yi et al., ). Chinese herbs have long been known for their antiviral effects and therefore examined for SARS-CoV's potential role. Of the 200 herbal extracts analyzed, Lycoris radiata, Artemisia annua, Pyrrosia lingua, and Lindera aggregata seemed to have an anti-SARS-CoV impact with a 50% effective aa(EC ₅₀) of 2.4-88.2 μg/ml (Li et al., 2005a). Additionally, tannic acid, 3-isotheaflavin-3-gallate, and theaflavin-3,3′-digallate, three black tea phenolics, collectively, exhibited inhibitory effects SARS-CoV 3CLpro with IC ₅₀ values of 3, 7, and 9, 5 μM, respectively (Chen et al., ). On the other hand, phenolic compounds from Isatis indigotica showed an inhibitory effect against SARS-CoV 3CLpro with IC ₅₀ values of 217, 752, 8.3, 365, and 1,210 μM, respectively for sinigrine, indigo, aloe emodin, hesperetine, and β-sitosterol (Lin et al., ).

Natural product(s) evaluated

Test system

Test dose

Proposed mechanism

References

Extract ( Rheum officinale Baill., Polygonum multiflorum Thunb.)

SARS-CoV spike (S) Protein

0-100 μg/ml

Inhibits the interaction of SARS-CoV S protein and ACE2

Ho, Wu, Chen, Li, & Hsiang, 2007

Herbal extracts ( Gentiana scabra, Dioscorea batatas, Cassia tora, Taxillus chinensis, Cibotium barometz)

SARS-CoV

25-200 μg/ml

3CL protease inhibition

Anthemis hyalina, Nigella sativa, and Citrus sinensis Extracts

SARS-CoV

1/50 and 1/100 dilution of ethanolic (100 g/200 ml)

Increased IL-8 level.

Significantly changed the expression of TRPA1, TRPC4, TRPM6, TRPM7, TRPM8, and TRPV4 genes

Natural product(s) evaluated

Test system

Dose/concentration

Proposed mechanism(s)

References

Extract ( Rheum officinale Baill., Polygonum multiflorum Thunb.)

SARS-CoV spike (S) protein

0-100 μg/ml

Inhibits the interaction of SARS-CoV S protein and ACE2.

Ho et al., 2007

Herbal extracts ( Gentiana scabra, Dioscorea batatas, Cassia tora, Taxillus chinensis, Cibotium barometz)

SARS-CoV

25-200 μg/ml

3CL protease inhibition

Anthemis hyalina, Nigella sativa, and Citrus sinensis

Extracts

SARS-CoV

1/50 and 1/100 dilution of ethanolic (100 g/200 ml)

Increased IL-8 level.

Significantly changed The expression of TRPA1, TRPC4, TRPM6, TRPM7, TRPM8, and TRPV4 genes

4′-O-methylbavachalcone and Neobavaisoflavone ( Psoralea corylifolia)

SARS-CoV

1-150 μM

Inhibitors of papain-like protease (PLpro)

Kim et al., 2014a

Mimulone, 3′-O-methyldiplacol, 4′-O-methyldiplacol, 3′-O-methyldiplacone, 4′-O-methyldiplacone ( Paulownia

Tomentosa)

SARS-CoV

0-100 μM

Inhibition of papain-like protease

Cho et al., 2013

7-Methoxycryptopleurine and Tylophorine

( Tylophora indica)

CoV-infected swine testicular cells

-

Inhibition of viral replication

Saikosaponins A, B ₂, C, D

HCoV-22E9

5-25 μM/L

Saikosaponin B ₂

inhibits viral attachment and penetration stages

Cheng et al., 2006

Tylophorin

CoV

0-100 μM

Targeting viral RNA replication and

Cellular JAK2 mediated dominant NF-κB activation

Yang et al., 2017

Scutellarein

SARS-CoV

0.01-10 μM

3CL protease inhibition

Yu et al., 2012

Silvestrol

HCoV-229E

0.6-2 μM

Inhibition of cap-dependent viral mRNA translation

Muller et al., 2018

Saikosaponins (A, B2, C, and D), naturally occurring triterpene glycosides obtained from Bupleurum spp., Heteromorpha spp., and Scrophularia scorodonia, exhibited antiviral activity against HCoV-22E9. Saikosaponin A, B2, C, and D have efficacy toward human CoV-229E, with EC ₅₀ values of 8.6, 1.7, 19.9, and 13.2 μM, respectively; saikosaponin B2 subdued viral attachment and penetration stages (Cheng et al., 2006a). These natural compounds effectively avoid the initial stage of HCoV-22E9 infection, like viral attachment and penetration, following co-challenge with the virus. In contrast, Rheum officinale, Polygonum multiflorum, and emodin have been investigated and proven to suppress SARS-CoV (S) protein and ACE2 interaction with IC ₅₀ valuesHo et al., 2007). Among 221 phytochemicals studied against SARS-CoV, 10 diterpenes, two sesquiterpenes, two triterpenes, and five lignans curcumin exhibited inhibitory effects at 3-10 μM concentration (Wen et al., ).

Interestingly, psoralidin showed a strong protease inhibitor influence on SARS-CoV with an IC ₅₀ value of 4.2 μM. Simultaneously, emodin, rhein, and chrysin hindered SARS-CoV (S) and ACE2 protein-protein interaction at 0-400 μM (T. Y. Ho et al., 2007; Kim et al., 2007). Conversely, ferruginol, 8β-hydroxyabieta-9(11),13-dien-12-one, 3β,12-diacetoxyabieta-6,8,11,13-tetraene, betulonic acid, betulinic acid, hinokinin, savinine, and curcumin inhibits replication of SARS-CoV at 0-80 μM (Wen et al., ). Other natural anti-CoV molecules include water extract from Houttuynia cordata, which displayed antiviral mechanisms against SARS-CoV, such as viral 3CL protease inhibition and viral RNA-dependent polymerase activity blockage (Lau et al., ). In the same way, Toona sinensis aqueous leaf extract inhibited SARS-CoV replication with EC ₅₀ values ranging from 30 to 40 μg/ml and SI values ranging from 12 to 17 (Chen et al., ). Procyanidin A2, procyanidin B1, and cinnamon tannin B1, extracted from Cinnamomi cortex, also hindered SARS-CoV infection at 0-500 μM (Zhuang et al., ).

Flavones and biflavones isolated from Torreya nucifera exude cytotoxic effect on SARS-CoV 3CLpro (Ryu et al., ), and Tylophorin and 7-methoxycryptopleurine isolated from Tylophora indica inhibit both N and S protein function and viral replication of enteropathogenic coronavirus transmissible gastroenteritis virus (Yang et al., ). Such molecules showed incredible antiviral activity with IC ₅₀ values of 0.018 and <0.005 μM, respectively. Tylophorine and 7-methoxycryptopleurine separated from T. indica have been shown to impede viral replication in coV-infected swine testicular cells (Yang et al., ). Six plant extracts ( Gentiana scabra, Dioscorea batatatas, Cassia tora, Taxillus chinensis, Cibotium barometz) asserted inhibitory effect against SARS-CoV 3CLpro with IC ₅₀ values of 39 and 44 μg/ml, respectively (Wen et al., ). Besides, diterpenoid, 8b-hydroxyabieta-9 (11), 13-dien-12-one, and lignin, savinin were reported to prevent SARS-CoV 3CLpro activity with a SI >667. In comparison, betulinic acid and savinin were found competitive inhibitors of SARS-CoV 3CLpro with Ki values of 8.2 and 9.1 μM, respectively. Tanshinones (e.g., tanshinone I, rosmariquinone) derived from Salvia miltiorrhiza also hindered infection and replication of SARS-CoV 3CLpro and PLpro at 1-1000 μM (Park et al., ). Further, myricetine and scutellarein exert an inhibitory effect of 0.01-10 μM for SARS-CoV 3CLpro (Yu et al., ). Likewise, (−) catechin gallate and (−)-gallocatechin gallate at 0.001-1 μg/ml prevented SARS-CoV nanoparticle RNA oligonucleotide (Roh, 2012).

Further, Eckol, 7-phloroeckol, phlorofucofuroeckoln, and dieckol segregated from Ecklonia cava obstructed virus adhesion to porcine epidemic cells at 1-200 μM with IC ₅₀ values of 22.5, 18.6, 12.2, and 14.6 μM, respectively (Kwon et al., ). Similarly, tomentine A, B, C, D, and E, 3′-O-methyldiplacol, 4′-O-methyldiplacol, 3′-O-methyldiplacone, 4′-O-methyldiplacone, mimulone, diplacone, and 6-geranyl-4′,5,7-trihydroxy-3′,5′-dimethoxyflavanone isolated from Paulownia tomentosa have been reported to suppress SARS-CoV PLpro at 0-100 μM (Cho et al., 2013). Anthemis hyalina, Nigella sativa, and Citrus sinensis extracts significantly reduced viral infection after HeLa-CEACAM1a (HeLa-epithelial carcinoembryonic antigen-related cell adhesion molecule 1a) has been afflicted with MHV-A59 (Mous Hepatitis Virus - A59) CoV, with A. hyalin being the most effective of the three plants assessed. Even though TRP gene expression was reduced upon diagnosis with these extracts, a rise in calcium ion level made it unconvincing to equate this impact with reduced viral replication (Ulasli et al., ). In another report, bavachinin, neobavaisoflavone, isobavachalcone, 4′-O-methylbavachalcone, psoralidin, and corylifol isolated from Psoralea corylifolia suppressed papain-like protease (Kim et al., 2014a). The investigation by Schwarz et al. (2014) noticed that juglanin prevents the SARS-CoV 3a channel with an IC ₅₀ value of 2.3 μM. Among the NIH clinical collection of 727 tested antiviral activity compounds against both murine and human coronavirus, alkaloid macetaxine (homoharringtonine) was perhaps the most effective (Cao, Forrest, & Zhang, ). On the other side, Quercetin, Quercetrin, Rutin, Cinanserin (1 and 2 dpi) isolated from H. cordata reported showed significant against CoV murine at 15.63-500 μg/ml (Chiow et al., 2016). Note that the SARS-CoV spike protein (S) uses ACE2 as a responsive binding site to invade host cells ( Li, ).

In contrast, broussochalcone B, broussochalcone A, 4-hydroxyisolonchocarpine, papyriflavonol A, 3′-(3-methylbut-2-enyl)-3′,4,7-trihydroxyflavane, kazinol A, broussoflavan A, kazinol F, and kazinol J extracted from Broussonetia papyrifera suppressed both SARS-CoV 3CLpro and PLpro, during which papyriflavonol A had the highest inhibition toward PLpro with an IC ₅₀ value of 3.7 μM (Park et al., ). Likewise, 7-methoxycryptopleurine (IC ₅₀: 20 nM) was much more efficient than tylophorine (IC50: 58 nM). In another investigation, tylophorine was also identified to approach viral replication of RNA and cellular JAK2-mediated dominant NF-ҟB activation in CoV at 0-1000 nM (Yang et al., 2017). In comparison, silvestrol impeded cap-dependent viral mRNA translation of HCoV-229E with an IC ₅₀ of 40 nM at 0.6-2 μM, and ouabain decreased both viral titers and viral yields and decreased the incidence of viral RNA copies at 0-3000 nM (Muller et al., 2018; Yang et al., 2020). New reports have shown that tetrandrin, fangchinoline, and cepharanthin, significantly inhibit initial phase viral-induced cell death in HCoV-OC43-infected human MRC-5 lung cells with IC ₅₀ values of 0.33, 1.01, and 0.83 μM, respectively (Kim et al., ). Also, lycorin, berbamine, emetin and mycophenolate mofetil were shown to intervene against HCoV-OC43, HCoV-NL63, MERS-CoV, and MHV-A59 at 0-5 μM. Lycorin and emetin suppressed cell division and hindered RNA, DNA, and protein synthesis, respectively while mycophenolate mofetil conferred an immune suppression effect on CoV species (Shen et al., ).

The docking studies analysis was used to examine the binding affinity and type of interaction among all compounds (67 natural molecules) and the target (Coronavirus (2019-nCoV) main protease). The outcomes of molecular modeling shown that among 67 molecules of biological origin crocin, digitoxigenin, and b-eudesmol act as inhibitors against the Coronavirus based on the energy types of interaction molecules (Aanouz et al., ). Also, 3CLpro sequence SARS-CoV-2 was assessed; its 3D homology model was developed and examined against a medicinal plant library containing 32,297 potential antiviral phytochemicals/Chinese traditional therapeutic molecules. Further, 5, 7, 3′, 4′-tetrahydroxy-2′-(3,3-dimethylallyl) isoflavone, myricitrin, methyl rosmarinate, (2S)-eriodictyol7-O-(600-Ogalloyl)-beta-d-glucopyranoside and calceolarioside B isolated from Psorothamnus arborescens, Myrica cerifera, Hyptis atrorubens Poit. Phyllanthus emblica and Fraxinus sieboldiana may act as anti-SARS-CoV-2 active compounds for more prioritization (Ul Qamar, Alqahtani, Alamri, & Chen, ).

4.2 Human herpes viruses and medicinal plants

Numerous members of the human herpesvirus (HHV) family are mostly causative factors for various human diseases. In contrast, many HHV infections are associated with Herpes Simplex Virus (HSV-1 and HSV-2). Other members of herpes viruses that cause multiple conditions are HHV-3 (Varicella-Zoster Virus), HHV-4 (Epstein Barr virus), HHV-5 (Cytomegalovirus), HHV-6, HHV-7, and HHV-8. HSV-1 and HSV-2 have encapsulated dsDNA viruses of the family Herpesviridae. HSV infection causes mucosal lesions in the ocular/perioral (usually HSV-1) and genital (usually HSV-2) areas and many other body sites. HSV tends to cause lifetime infection by developing itself on the sensory neurons and thus can be reactivated by different stimuli, like sun exposure, sore throat, immune suppression, menstrual cycles, or anxiety (Fatahzadeh & Schwartz, ). The transmission of HSV results from direct contact with infected lesions and could occur via vertical transmission from infected mother to fetus. However, the disease is typically self-limited and can be handled with antiviral drugs. However, consequences could develop in neonates, and immunosuppressed persons lead keratoconjunctivitis and life-threatening meningitis (Arduino et al., 2008; Chentoufi & Benmohamed, ).

Hardly any vaccine is recommended against HSV, even though there are no effective drugs that could neutralize innate HSV infection. A few primary and metastatic conditions could be monitored by analogous like acyclovir, penciclovir, and prodrugs. Moreover, the expansion of resistance to antibiotics virus is becoming a severe problem, especially in immune-compromised patients (Morfin & Thouvenot, ). Therefore, the discovery of new anti-HSV agents with diverse mechanisms is significant to HSV's clinical management. Plant extracts attracted substantial attention while looking for alternative compounds with anti-herpetic activity. Intriguingly, innumerable plant-derived extracts and molecules were already known to prevent HSV replication (Table 2) (Akram et al., ; Li et al., ).

Plant name

Natural product(s) evaluated

Virus assessed

Culture /Animal model assessed

Proposed mechanism

References

Labiatae and Verbenaceae families (essential oils)

Unknown

HSV-1 and HSV-2

In vitro

Virucidal, inhibition of viral binding, inhibition of viral entry

Aglaia odorata (Chinese perfume plant), Moringa oleifera (Moringa) and Ventilago denticulata

Unknown

HSV-1

In vivo

Inhibition after viral attachment

Lipipun et al., 2003

Houttuynia cordata (fish mint)

Quercitin, Isoquercitrin, and Quercitrin

HSV-1 and HSV-2

In vitro

Inhibition of NF-kB activation, inhibition of viral binding, inhibition of viral entry

Eucalyptus camaldulensis (River Red Gum)

Unknown

HSV-1 and HSV-2

In vitro

Inhibition before and after virus adsorption

Cassia stipulacea (Quebracho) and Escallonia illinita (Ñipa)

Unknown

HSV-1

In vitro

Inhibition after virus adsorption

Pacheco et al., 1993

Aristotelia chilensis (Chilean Wineberry), Drymis winteri (Winter's Bark), Elytropus chilensis (Quilmay) and Luma apiculata (Chilean Myrtle)

Unknown

HSV-2

In vitro

Inhibition after virus adsorption

Pacheco et al., 1993

Melaleuca alternifolia (tea tree)

Unknown

HSV-1 and HSV-2

In vitro

Inhibition of virus binding, inhibition of virus entry

Garozzo et al., 2009

Alpinia officinarum (Lesser Galangal) and Geum japonicum (Asian herb Bennet)

Unknown

HSV-1

In vitro

Inhibition after virus adsorption

Kurokawa et al., 1995

Paeonia suffruticosa (Mudan), Phellodendron amurense (Amur Cork tree), Polygala tenuifolia (Yuan Zhi), Polygonum cuspidatum (Asian Knotweed), Rhus javanica (Java Brucea), Syzygium aromaticum (clove), Terminalia arjuna (Arjun tree) and Terminalia chebula (Black Myrobalan)

Unknown

HSV-1

In vitro and in vivo

Inhibition after virusadsorption

Kurokawa et al., 1995

Licorice roots of Glycyrrhiza glabra were used to prepare a 2% topical acid cream, which contains carbenoxolone sodium. The cream was used to cure12 patients having acute oral herpetic (HSV) infections. The disease symptoms such as pain and dysphagia were resolved after applying the cream six times a day within a short span of 24-48 hr. In contrast, ulceration and lymphadenopathy were shown to cure steadily within 24-72 hr (Partridge & Poswillo, ). Samarangenin B extracted from the leaves of Limonium sinense observed suppression of HSV-1 α gene expression (Kuo et al., ). Further, Artocarpus lakoocha containing oxyresveratrol was reported to prevent early and late HSV-1 and HSV-2 viral replication phases, respectively (Chuanasa et al., ). Pterocarnin A compound isolated from Pterocarya stenoptera impeded HSV-2 from adhesion and infiltration to host cells (Cheng et al., ). Yatein extracted from Chamaecyparis obtuse substantially inhibits HSV-1 replication in HeLa cells without noticeable cytotoxic effects (Kuo et al., ).

In comparison, several H. cordata flavonoids were assessed to determine their capability to obstruct the HSV-2 replication cycle. The principal flavonoids quercetine, quercitrine, and isoquercitrine showed significant HSV-2 activity (Chen et al., ). Subsequent investigation assessed that the mode of action could be behind the anti-herpetic activity of H. cordata, like adsorption, entry, post-infection by NF-kB, and virucidal activity (Hung et al., ). Also, meliacin obtained from Melia azedarach was shown to induce TNF-α and IFN-α production and reduce HSV-2 by improving virus-induced pathogenesis in the mouse genital model of herpetic inflammation (Petrera & Coto, ).

Comparably, the aqueous extract from Rhododendron ferrugineum blackberry extract and the extract from Myrothamnus flabellifolia enriched with proanthocyanidin prevented the HSV-1 infection (Danaher et al., ; Gescher, Kuhn, Hafezi, et al., ; Gescher, Kuhn, Lorentzen, et al., ). Glucoevatromonoside, a cardenolide from Digitalis lanata, alter the cellular electrochemical gradient and hinder the proliferation of HSV-1 and HSV-2 in cells (Bertol et al., ). The natural products from the marine ecosystem such as algae and sponges produce active metabolites with anti-HSV activity (Sagar et al., ; Vo et al., ). Houttuynoids A-E extracted from H. cordata, showed effective anti-HSV-1 activity (Chen et al., 2012a). Another resveratrol compound isolated from the Veratum grandiflorum inhibited NF-kB activation, the primary bioactive substance present in grapes, peanuts, legumes, or other plant-derived matrices and perhaps in red wine (Chen et al., 2012b).

Numerous studies documented the antibacterial activity of resveratrol against the ACV-resistant and wild-type HSV-1 and HSV-2 replication cycles in cell lines and animal studies (Faith et al., ; Leyton et al., ). Compounds like spiroketalenol ether derivatives extracted from Tanacetum vulgare rhizome extract served as cell entry inhibitors and apprehend HSV-1 gC and HSV-2 gG glycoproteins production (Alvarez et al., ). Essential oils derived from Glechon spathulata and Glechon marifolia noted antiviral activity against HSV-1, which became effective after infecting Vero cells (Venturi et al., ). Furthermore, essential oils derived from plants of the families Labiatae and Verbenaceae have an antiviral effect on HSV. Vero cells after incubation with HSV and essential oils for 48-72 hr dramatically lowered viral titers of HSV-1 and HSV-2. It is important to note that their modes of action were related to the pre-infective stages (Brand et al., ). An analysis showed that the leaves of Morus alba L. exhibited antiviral properties against HSV-1 and HSV-2. Kuwanon X, a stilbene polyphenol derivative active compound found in this plant, reported antiviral activity against HSV at different phases of the infection process, preventing adsorption and penetration, and instant early and late gene expression of HSV-1, and replication of HSV-1 DNA (Ma et al., ).

Ethanolic extract from the Eucalyptus camaldulensis leaves prevents HSV-1 and HSV-2 infection during and after illness to Vero cells. Synergism was observed in cultured cells among acyclovir and ethanol extracts (Abu-Jafar & Mahmoud, ). Similarly, the antiviral activity of 24 new metabolites from the leaves of Eucalyptus sideroxylon and four new metabolites from genus Eucalyptus were reported. In contrast to HSV-1 and HSV-2 these compounds suppressed hepatitis A, coxsackie, and adenoviruses. Notably, antiviral activity against HSV-2 was exhibited by inhibiting the entrance of viruses and consequent infection processes (Okba et al., ). Xanthotoxin, bergapten, imperatorin, phellopterin, isoimperatorin, imperatorin, and phellopterin isolated from dichloromethane fruit extract of Angelica archangelica were explored as the practicable antiviral agents toward HSV l. Imperatorin and phellopterin showed the highest effect, minimizing replication of HSV-1 by 5.61 logs and 4.7 logs, respectively. The extract resulted in a decrease in the titer of the virus concerning the control of the virus. The findings demonstrate that coumarins of A. archangelica may be an excellent material for the formation of an alternative natural anti-HSV-1 compound (Rajtar et al., ).

Further, 12 compounds isolated from Eucalyptus globulus leaves and twigs were noticed to have antiviral efficacy against HSV-1 and HSV-2. Tereticornate A has been assessed to holds the most incredible action against HSV-1, relatively high than acyclovir. Cypellocarpin C showed significant antiviral activity against HSV-2, higher than that offered by acyclovir (Brezáni et al., ). Organic extracts relating to the Peganum harmala species showed antiviral activity against HSV-2 by disrupting virus entry (Benzekri et al., ). Besides, Yatein separated from C. obtuse prevents HSV-1 alpha gene expression, along with ICP0 and ICP4 expression of genes, by halting HSV-1 DNA replication and structural protein expression in HeLa cells ( Wang et al., ). Natural anti-HSV substances' availability should provide novel pharmacological properties against the virus for future use in monitoring HSV infections.

4.3 Medicinal plants in viral hepatitis

Viral hepatitis or inflammation of the liver is associated with several different viruses called hepatitis A, B, C, D, and E. Since exposure to any of these viruses results in acute infection, type B and C are distinctive in inducing chronic conditions.

4.3.1 Hepatitis B virus

Hepatitis B virus (HBV) a prototype virus belonging to Hepadnaviridae family, is an enveloped virus with a relaxed circular and partly double-stranded DNA genetic structure (dsDNA) (Liang, ). HBV induces hepatitis B and is transmitted by contact with the virus-containing blood or other body fluids. Though some spontaneous recovery following acute hepatitis B is prevalent, due to the extreme risk of cirrhosis, HCC therapy is advised for chronic infection. The HBV vaccine design and the national vaccination policy against hepatitis B in endemic regions like Taiwan have helped to alleviate HBV infection and decreased the prevalence of HCC in the childhood stage (Ni & Chen, ).

Given the availability of effective vaccinations, the existing HBV compromised population remains at the threat of end-stage liver diseases, mostly in areas where vaccine schedules are inaccessible. Nucleotide/nucleoside analogs like lamivudine, adefovir, tenofovir, telbivudine, entecavir, and the immune modulator pegylated interferon-α (Peg-IFN-α) were used for the treatment of HBV infections (Kwon & Lok, ). Nevertheless, it is difficult to eradicate HBV from the body once a prolonged inflammation occurs. The condition gets exacerbated by threats of selecting drug-resistant viral mutants, failure of diagnosis in non-responders, and possible future viral recurrence. Thus, anti-HBV drugs' development will always be of significance for the scientific attention and hepatitis B management system's assistance to diagnose about 300-400 million carriers globally (Franco et al., ).

Phyllanthus species are considered an essential source of antiviral bioactive metabolites such as lignans, including hypophyllanthine and phyllanthine, flavonoids (ternatin), and alkaloids such as quercetin. They can block the endogenous DNA polymerase enzyme of HBV, which is crucial for viral replication (Venkateswaran et al., ). A variety of bioactive metabolites extracted from Phyllanthus niruri were also evaluated for their inhibitory potential, using sera containing HBsAg, collected from chronic HBV patients (Thyagarajan et al., ). Subsequent studies have revealed the in vivo efficiency of P. niruri extract in eliminating HBV in 3-6 weeks in mammals. A 90-day treatment with plant extracts successfully reduced the HBV antigen to undetectable levels among two-thirds of HBV-positive patients (Wang et al., ). Further, numerous studies were conducted in the last several years to recognize anti-HBV molecules from medicinal herbs (Cui et al., ; Qiu et al., ; Zhan et al., ; Zhang et al., ). For examples, the antiviral effects of the saikosaponins from Bupleurum species and the ethanol extract from Polygonum cuspidatum were reported against HBV in vitro (; Chang et al., ; Chang et al., ). Further, curcumin showed to suppress the HBV gene's replication and an appearance by controlling the peroxysome proliferator-activated gamma receptor co-activator 1-alpha (PGC-1α), the HBV transcription co-activator (Rechtman et al., ). Furthermore, Phyllanthus, Salvia miltiorrhiza, Rheum palmatum L., and Radix astragali and chemical compounds like oxymatrine, artemisinin, artesunate, and wogonin also reported promising anti-HBV activities (Cui et al., ). Other examples include isochlorogenic acid A, amide alkaloid, and dehydrocheilanthifoline from Laggera alata, Piper longum, and Corydalis saxicola experienced high anti-HBV activities (Hao et al., ; Jiang et al., ; Zeng et al., ). The LPRP-Et-97,543, isolated from the roots of Liriope platyphylla, hinders the mechanism of HBV's action by regulating the gene expression and the DNA replication by viral proteins by interacting with the pathway of NF-αΚB nuclear factor (Huang et al., ).

There seems to be a lack of studies on bioactive components' mode of action against HBV, while most natural compounds were proven to effectively suppress the HBV (Wu, ) (Table 3). For instance, Acanthus ilicifolius L. significantly decreases HBV-induced liver damage by lowering the transaminase (Wei et al., ). Gymnema sylvestre phytoconstituents prevent HBsAg binding and HBV DNA polymerase activity (Subashini and Rajendran, ). Further, the expression of intracellular HBV DNA in HBV WT-or mutant-transfected HepG2 cells declined following Phyllanthus extract treatment. Phyllanthus triggered interferon-beta, cyclooxygenase-2, and interleukin-6 mRNA expression in HBV WT-transfected HepG2 cells, probably by modulation of extracellular signal-regulated kinases and c-jun N-terminal kinases and by induction of retinoic acid-inducible gene-I, toll-like receptor 3, myeloid distinctions of primary response gene, and tumor necrosis of fac (Jung et al., ). Two new major C-boivinopyranosyl flavones (luteolin-6-C-β-d-boivinopyranosyl-3′-O-β-d-glucopyranoside and chrysoeriol-6-C-β-boivinopyranosyl-4′-O-β-d-glucopyranoside) isolated from Alternanthera philoxeroids showed substantial anti-HBV activity by reducing HBsAg secretion in HepG2.15 cells (Li et al., ).

Natural products/Extracts evaluated

Virus strain assessed

Culture/Animal model assessed

Proposed mechanism

References

1,2,3,4,6-penta-O-galloyl-beta-d-glucoside ( Saxifraga melanocentra Engl.& Irmsch)

HCV

COS-7 fibroblast-like cells

Inhibition against HCV NS3 serine protease

Zuo et al., 2005

Epigallocatechin-3-gallate

HCV

Huh7 cells

Inhibits viral entry by affecting the fluidity of the HCV envelope; inhibits viral entry

Rhusflavanone ( Rhus succedanea and Garcinia multiflora) as well as their methyl ethers and acetates

MV

Vero cell lines

Undefined

Lin et al., 1996

Zanthoxylum chalybeum and Warburgia ugandensis

MV

Vero cell lines

Undefined

Olila et al., 2002

Olinia rochetiana and Warburgia ugandensis

MV

U937 cell lines

Neutralize virus particles

Parker et al., 1997

Ethanol extract of leaves ( Senna angustifolia), ethanol extract of leaves ( Tridax procumbers), and methanol extract of leaves ( Vernonia cinerea)

DENV-2

Vero cells

Undefined

Hederasaponin B ( Hedera helix)

EV 71

Vero cells

Inhibition of viral capsid protein synthesis

Phytol, aloe-emodin, byzantionoside B, a mixture of trans-martynoside and cis-martynoside, a mixture of trans-isomartynoside and cis-isomartynoside, luteolin-7- O- β-d-glucopyranoside, and apigenin-7- O-[ β-d-apiofuranosyl (1→6)- β-d-glucopyranoside (Lindernia crustacean)

EBV

Burkitt's lymphoma cell line (P3HR)

Undefined

Consequently, ethanol extract of Sanguisorba officinalis and its significant compounds (ziyuglycoside I and II) against HBV in HepG2.2.15 cells inhibit replication and antigen secretion of HBV. Hence, describing the plant's tendency as novel candidates for the treatment of HBV-related diseases (Jang et al., 2018). The anti-HBV effect of Abrus cantoniensis were explored both in vitro and in vivo studies. Treatment of A. cantoniensis strongly suppressed the development of HBV DNA, Hepatitis Be Antigen (HBeAg), and Hepatitis B surface antigen (HBsAg) in HepG2.2.15 cells and rAAV8-1.3HBV transfected mice, which provides a base for its possible clinical usage (Yao et al., ). Quercetin and myricetin-3-O-rhamnoside extracted from Guiera senegalensis leaves showed antiviral activity (HBsAg and HBeAg assay) in HepG2.2.2.15 HBV-reporter cells. Quercetin notably repressed HBsAg and HBeAg synthesis by approximately 60 and 62%, respectively, compared to myricetin-3-O-rhamnoside by 44 and 35%. Their probable anti-HBV mode of action was expected by the ability to bind with viral Pol/RT and core as well as host NTCP proteins (Parvez et al., 2020).

Furthermore, the HBV inhibition activities of polysaccharide from Radix isatidis were mediated by the stimulation of the IFN-α-dependent JAK/STAT signal pathway and the initiation of protein expression against HBV (Wang et al., ). Swertisin obtained from Iris tectorum displayed a significant inhibitory effect for HBV replication by inhibiting HBeAg and HBsAg and HBV DNA (Xu et al., 2020). Although novel anti-HBV inhibitors were developed, the combination of remedies with conventional nucleotide/nucleoside analogs or IFN-α-based hepatitis B therapy must also be assessed in future research.

4.3.2 Hepatitis C virus

HCV is a flavivirus with a positive-sense ssRNA, usually transmits through blood-to-blood interactions, intravenous injections, blood transfusion, and varying exposures to blood toxic substances. Due to the overly abstract nature of HCV, a precautionary vaccine has not been available yet. Approximately 70% of infections are consistent, affecting an estimated 300 million carriers worldwide, among which 1-3% can proceed to end-stage liver diseases, such as cirrhosis and HCC (El-Serag, ). The recommended treatment comprises Peg-IFN-α plus oral ribavirin parenteral. Nevertheless, few challenges exist in the current method of HCV treatment. They have limited efficacy for specific viral genetic variants, unavoidable selection of drug-resistant mutants, adverse side effects, exorbitant prices of medication, patient adherence issues, and challenges in diagnosing communities such as non-responsive patients and patients with liver transplantation (Welsch et al., ). The rapid expansion of anti-HCV substances is indeed essential to address such deficiencies.

Table 3 summarizes the antiviral potential of different natural products determined against HCV infection. For instance, Silybum marianum and its flavonolignans showed significant anti-HCV activity in vitro (Polyak et al., , ). Many clinical trials showed a viable impact on reducing the viral load (Marino et al., ; Neumann et al., ). Curcumin was reported as a critical inhibitor of HCV replication by conceivably restricting the sterol regulatory element-binding to protein-1 (SREBP-1)-Akt pathway Kim et al., ), and its adverse impact on HCV entry (Anggakusuma et al., ). Many natural products deter HCV entry, including epigallocatechin-3-gallate, griffithsin, ladanein, and tellimagrandin I (Calland et al., ; Ciesek et al., ; Haid et al., ; Meuleman et al., ; Takebe et al., ). Similarly, chebulagic acid and punicalagin hydrolyzable tannins were found as competitive HCV intake inhibitors (Lin et al., ). Both tannins inactivate free virus particles, inhibit viral adhesion and penetration of the host cell, and interrupt HCV cell-to-cell post-infection transfer. As the HCV immunization is unavailable, the identification of new anti-HCV entry inhibitors could help develop preventive hepatitis C therapy/medication.

Loliolide isolated from Phyllanthus urinaria inactivates the HCV virus and stops viral attachment and entry/fusion (Chung et al., ). Leaves extract and fractions of Ficus fistulosa using Huh7it cells and HCV JFH1a inhibited HCV JFH1a with an IC ₅₀ value of 20.43 ± 4.51 μg/ml (Hafid et al., ). The dichloromethane extract of Artocarpus heterophyllus demonstrated good anti-HCV activity using Huh7it-1 cells with an inhibitory concentration (IC ₅₀) of (1.5 ± 0.6) μg/ml. A. Heterophyllus impeded the viral entry process by direct virucidal activity and targeting host cells and HCV RNA replication. HCV protein expression was substantially decreased by elevated-concentration treatment (Hafid et al., ). Antiviral activity of methanol extract of Ajuga bracteosa, Ajuga parviflora, Berberis lyceum, and Citrus lemon against HCV infected HepG2 cells showed that 24-hour treatment with A. parvifloras exhibited maximum antiviral activity, accompanied by A. bracteosa. The findings demonstrate these as a substitute standard therapy or in combination with conventional HCV therapies to treat HCV infections (Yousaf et al., ). Two fractions "N1" and "N8" isolated from acetone extract of Nymphaea alba suppressed HCV NS3 gene expression in transfected Huh-7 cells with an EC ₅₀ value of 37 ± 0.03 and 20 ± 0.02 μg/ml, respectively. Besides, the combination of fractions with the standard antiviral drug showed stimulatory activity to suppress HCV replication. N. alba and its isolated compounds may offer a promising source regimen against HCV, alone or even in mixture with other prospective anti-HCV entities (Rehamn et al., ).

4.4 HIV/AIDS and medicinal plants

A comprehensive list of herbal ingredients for HIV infection was examined (Cos et al., ; Singh & Bodiwala, ) (Table 3). In contrast, marine products with anti-HIV activity were reported as potential anti-HIV treatment (Kim et al., 2011; X. Zhou et al., ). Phytolacca americana is a potent source of a set of plant proteins known as pokeweed antiviral protein (PAP). Three isoforms, specifically from spring leave PAP-I, early summer leaves PAP-II, and late summer leaves PAP-III was identified as a class of ribosome-inactivating proteins (RIPs) responsible for causing depurination of genomic HIV-1 RNA (Rajamohan et al., ). Similarly, Momordica charantia and Gelonium multiflorum are considered useful sources of an anti-HIV protein MAP30 and GAP31, similar to RIPs known for their anti-HIV potency (Schreiber et al., ).

Furthermore, the leaves of P. americana also contain an anti-HIV protein PAP29, having a prophylactic anti-HIV potential. P. Wang and Tumer () reported that PAP isolation cleaves supercoiled DNA into linear and straightforward forms using the same active site required to remove rRNA purine. The RIPs are toxic N-glycosidases that purify the typically preserved α-sarcin loop of large rRNAs. Thus, depuration disables the ribosome, consequently obstructing its further involvement in protein synthesis. Several studies have shown that RIP's enzymatic activity is not only restricted to site-specific activity on ribosome rRNAs but also entails the depuration and nucleic acid scission of other targets (Barbieri et al., ; Horrix et al., ; Nicolas et al., ). Trichobitacin, a RIP, extracted from the roots of Trichosanthes kirilowiiis was reported to decline the appearance of the p24 HIV-1 antigen by reducing the number of antigens in HIV-positive cells in an acute in vitro assay but failed in cases of chronic infection (Zheng et al., ). Cyanovirin-N extracted from marine algae showed an inhibitory effect on HIV through aborting transmission and cell to cell fusion of HIV by interacting strongly with gp120 (De Clercq, ). Several sulfated polysaccharide groups extracted from seaweeds possess anti-HIV effects by interfering with viral adsorption (Duarte et al., ; Schaeffer & Krylov, ). Alkaloid extracts of P. niruri exhibited an inhibitory effect on HIV by monitoring the inhibition of HIV-induced cytopathogenecity in human MT-4 cells (Naik & Juvekar, ). Furthermore, coumarin-containing calophyllum species exhibited an inhibitory effect on HIV (Cesar et al., ; Huerta-Reyes et al., ). Similarly, the crude extracts of A. annua and Artemisia afra revealed promising anti-HIV efficacy (Lubbe et al., ). In regards, tricyclic coumarin reported from Calophyllum brasiliense stem bark suppressed HIV replication by repressing the activation of nuclear factor-kappa B (NF-κB) in in vitro models (Kudo et al., ).

The root extract of Pelargonium sidoides displays potent anti-HIV-1 activity by protecting peripheral blood mononuclear cells and macrophages from infection with several X4 and R5 tropic HIV-1 strains. Thus, it is considered a novel herbal medicine for anti-HIV-1 therapy with different action mechanisms and complementary to current single-molecule drugs (Helfer et al., ). Furthermore, Cistus incanus inhibited clinical HIV-1 and HIV-2 isolates in vitro, and no resistant viruses appeared throughout 24 weeks of continuous propagation of the virus in the presence of C. incanus aqueous extract (Rebensburg et al., ). Methanol extracts of Euphorbia spinidens Bornm (Euphorbiaceae) possess significant antioxidant activity due to high phenolics terpenes and saponins and flavonoid compounds and have a strong antiviral effect on HSV-1 by inhibiting the replication of the virus (Karimi et al., ; Mohammadi et al., ). Patentiflorin A isolated from Justicia gendarussa, shows significant activity against various HIV strains by acting as a potential HIV-1 reverse transcription inhibitor with IC ₅₀ values ranging from 15-21 nM (Zhang et al., 2017a, 2017b).

Besides this, a diverse range of medicinal plants such as Withania somnifera (Williams-Orlando, ), Tinospora cordifolia (Husain et al., ), Moringa oleifera (Monera-Penduka et al., ), Hypericum perforatum (Béjaoui et al., ), Silybum marianum (Lovelace et al., ), Panax ginseng (Cho & Kim, ), Hypoxis hemerocallidea (Jegede et al., ), Sutherlandia frutescens (Wilson et al., ), Lobostemon trigonus (Koffuor et al., ), and Curcuma longa (Kim et al., 2014b) were used in the diagnosis and treatment of AIDS. In comparison, four new lignans from the aerial parts of Justicia procumbens were examined for anti-HIV-1 activity. One of the new secoisolariciresinol dimethyl ether acetate showed significant anti-HIV-1 activity with an IC ₅₀ of 5.27 μM in vitro (Xu et al., 2019). Premised on the scientific advances till now, rapid advances in identifying natural antivirals against HIV must produce novel therapeutic regimens that would play a critical role in combating the existing immediacy of anti-HIV/AIDS therapeutics.

4.5 Anti-influenza virus and medicinal plants

Influenza A, B, and C viruses (IFA, IFB, and IFC) are encapsulated negative-sense ssRNA viruses categorized in the Orthomyxoviridae family. Such viruses can cause respiratory infection with symptoms include fever, headache, sore throat, sneezing, and muscle and joint pain, which can lead to devastating and potentially lethal situations like pneumonia (Eccles, ; Rello & Pop-Vicas, ). IFA (most epidemics) has a broad array of hosts, such as birds, human beings, and other mammals. At the same time, IFB seems to harm people naturally, and IFCs could be separated from humans and pigs (Pleschka, ). The infection of influenza viruses has caused significant human morbidity, and approximately 250,000 to 500,000 fatalities happen yearly as a consequence of periodic epidemics. This figure was documented to rise to about 20-40 million deaths in major pandemics, as was the case with the Spanish flu of 1918 (Saunders-Hastings & Krewski, ).

Hemagglutinin (HA) and neuraminidase (NA) protein envelopes are developed by the IF vaccines through prior contact or immunization, thus, making any pre-existing antibody inefficient and susceptible to infection. Another concern is the pervasive growth of drug resistance, mostly M2 ion channel blockers of amantadine and rimantadine, in the first wave of anti-influenza drugs. Resistant strains of available neuraminidase inhibitors such as oseltamivir and zanamivir (which mainly prevent the release of mature influenza viruses) have also been identified (Samson et al., ). As a result of drug resistance development, the rapid evolution of influenza viruses, and the incidence of many recent outbreaks (e.g., H5N1, H1N1, H7N9), more advanced antiviral strategies are urgently needed to prevent and control potential pandemics with evolving influenza strains (Shao et al., ). Numerous natural products have been assessed for their adverse effects on influenza (Table 3).

Pelargonium estides root extract restricts IFA entry influences, viral hemagglutination, neuraminidase function, and improves influenza-infected mice (Theisen & Muller, ). Aqueous extract from Taraxacum officinale inhibits IFA infection and reduces the activity of polymerase and nucleoproteins (NP) RNA levels (He et al., ). Several plant secondary metabolites were also determined as possible inhibitors of NA influenza (Grienke et al., ) such as chalcones from Glycyrrhiza inflata (Dao et al., ), xanthones from Polygala karensium (Dao et al., ), homoisoflavonoids from Caesalpinia sappan (Jeong et al., ), and spirooliganone B from the roots of Illicium oligandrum (Ma et al., ). Lariciresinol-4-O-d-glucopyranoside isolated from the root of Isatis indigotica hindered the IAV-induced pro-inflammatory response. The underpinning coping mechanism against IAV infection derives from pharmacological actions on the immune system, signal transduction, cell cycle, and metabolism (Li et al., 2015; Zhou et al., ). The Sambucus nigras activities against influenza were investigated extensively, especially in the vicinity (Roschek et al., ; Ulbricht et al., ). Studies have shown the potency of S. nigra toward infectious disease, which may be caused by immune system stimulation ( Ho et al., ; Ho et al., ). Immunomodulating peptic polysaccharides, polyphenolic, and flavonoid of S. nigra are responsible for suppressing the viruses. This plant's berries and flowers are documented from diverse cultures (Porter & Bode, ).

The double-blind trial was conducted among 40 adults and children in southern Israel confirmed to have influenza B. The fruit of Sambucus nigra (black elder) syrup or placebo 1 tbsp b.i.d. (for children) or 2 tbsp b.i.d. (for adults) was given. Symptom severity and duration (mean 1.3 days shorter with black elders) were appreciably lesser in the black elder group than placebo (Zakay-Rones et al., ). A similar double-blind trial of 60 adult Norwegians with influenza A or B was conducted. Again, symptom severity was significantly less with black elders than placebo, and in this case, recovery was on average 4 days quicker with black elders. The use of rescue medication was also notably less in the black elder group versus placebo. There were no adverse effects in either of these trials (Zakay-Rones et al., ). Recently, a randomized trial of 312 Australian adults undertaking international travel by coach received black elder capsules 300 mg b.i.d. before travel and t.i.d. during travel and after arrival, or placebo. Each participant took their assigned medicine for a total of 14 days. There was no difference between the groups in terms of the incidence of clinical viral respiratory infections. However, these colds' duration was significantly shorter and severity substantially less in the black elder group than the placebo. There was no difference between the two groups' adverse effects, suggesting no significant danger from black elders (Tiralongo et al., 2020). The development of these natural anti-influenza agents for clinical use will further extend the portfolio of drugs for prophylactic treatment of severe flu epidemics or pandemic.

4.6 Enterovirus 71 and medicinal plants

Preventive EV71 vaccines were currently developed, and palliative care is being used to improve the symptoms. However, many other natural products and herbal medicines exhibited inhibitory activity against EV71 infection (Table 3). The analysis revealed that O. basilicum extracts and isolated compounds effectively prevent EV71 disease and replication (Chiang et al., ). In contrast, raoulic acid recognized as a CVB inhibitor suppresses EV71 (Choi et al., ). Similarly, epigallocatechin gallate from green tea tamper with EV71 replication by modulating the redox cell environment (H. Y. Ho et al., ). Gallic acid from Woodfordia fruticosa flowers showed anti-EV71 activity (Choi et al., ). Anti-EV71 activity of chrysosplenetin and penduletin, two o-methylated flavonols confined from the leaves of Laggera pterodonta, showed vigorous anti-EV71 activity with low cytotoxicity. Throughout the time-of-addition assay, all compounds impeded progeny virus development and RNA replication by almost 100% when incorporated within 4 hr post-infection (Zhu et al., ). In relation, there were studies undertaken to study the antiviral capabilities of various plant or algae-derived EV 71-containing compounds (Chiu et al., ; Lin et al., ; Wang et al., 2011a; Wang et al., 2012d; Wang et al., ; Yang et al., ).

Contrary, phytochemicals evaluated for EV71 antiviral activity showed low cytotoxicity. Some of them, such as aloe-emodin, (Lin et al., ) extract of H. cordata, kappa carrageenan (Chiu et al., ) extract of Kalanchoe gracilis, and extract of Paris polyphylla Smith (Wang et al., 2011b) have a precise molecular mechanism(s) of action. The research tries to evaluate 12 frequently used antiviral herbs preferred by Chinese government agencies for the HFMD. H. cordata found the only remedy with potent antiviral activity against both EV71. These study results may justify follow-up experiments to determine the precise molecular mechanisms of action and to analyze the plant's anti-EV71 capability in the animal study (Chen et al., ). Chebulagic acid, isolated from Terminalia chebula fruit, displayed antiviral activity against human enterovirus 71 in vitro and in vivo models. Its treatment significantly reduced the viral cytopathic effect on rhabdomyosarcoma cells with an IC ₅₀ of 12.5 μg/ml. The use of chebulagic acid therapy in patients with enterovirus 71 effectively reduced mortality and alleviated clinical symptoms by inhibiting viral replication. Chebulagic acid may be a potent pharmacological entity to influence enterovirus 71 infections (Yang et al., 2013). Hederasaponin B and 30% ethanol extract of Hedera helix against EV71 subgenotypes C3 and C4a in Vero cells showed vigorous antiviral activity by lowering visible development CPE. It further impeded viral VP2 protein expression, implying the suppression of viral capsid protein synthesis (Hong et al., ; Song et al., ). Without appropriate medical care to prevent and treat EV71 infection, further studies are needed to explore novel enteroviral antivirals.

4.7 Respiratory syncytial virus and medicinal plants

RSV is an enshrouded negative-stranded ssRNA virus belonging to the Paramyxoviridae family. RSV is a prevalent virus responsible for respiratory illness in infants and toddlers (Hall, ). Almost all children often get afflicted with RSV well before 2 years (Braciale, ). It develops mild symptoms and bronchiolitis or pneumonia in infants and immunocompromised patients (Sigurs et al., ). Even though RSV causes the most severe illness in premature children, it continues to haunt living beings throughout their lifespan. Immune response to RSV is usually not sufficient to provide protection, but instead, humans are susceptible to reiterated re-infections (Hall et al., 2009; Henderson et al., ), that may be life-threatening for older or immune-compromised patients (Falsey & Walsh, ). Presently, RSV immunotherapy is not applicable. The therapies available for diagnosing RSV infections like palivizumab (a monoclonal antibody against RSV fusion protein) and ribavirin (nucleoside analog) are slightly effective. Therefore, it is necessary to develop new antivirals to manage RSV infections, and numerous plant-derived natural products were shown to display anti-RSV activity (Table 3).

Uncinoside A and B, the two isolated chromone glycosides from Selaginella uncinata, effectively inhibit RSV inflammation, and biflavonoids, namely genkwanol B, genkwanol C, and stellenranol derived from Radix Wikstroemiae, are said to have antiviral activity against RSV (Huang et al., ; Ma et al., ). Further, flavonous 6-C-monoglycosides from Lophatherum gracile leaves reported curtailing RSV infection in the cytopathic impact reduction assay (Wang et al., 2012c). Numerous natural anti-RSV therapies such as the herbal prescription ( Cimicifuga foetida L., and bioactive compound cimicifuga) relieve respiratory diseases (Wang et al., 2011; Wang, Ho, et al., ; Wang, Chen, et al., ). Furthermore, chebulagic acid and punicalagin hydrolyzable tannins possess antiviral activity toward RSV infection. The two tannins can explicitly inactivate RSV entities and obstruct viral entry aspects, like binding and fusion. They are inadequate against the transmission of RSV post-infection and could contravene the same event in MV, which is another paramyxovirus (Lin et al., ). Certain herbal products will help improve the respiratory tract symptoms induced by RSV, like inflammation of the respiratory system to target the viral infection. Resveratrol is one specific illustration documented to stabilize IFN-γlevels and prevent the trachea's inflammation/hyperresponsiveness throughout RSV infection in mice, implying its suitability to minimize airway symptoms triggered by RSV (Zang et al., ). Tangeretin and nobiletin (polymethoxylated flavones) obtained from Citrus reticulate (Pericarps) impaired RSV replication intracellularly. Tangeretin significantly suppressed RSV phosphoprotein (P protein) expression through virus-cell fusion inhibition at an early stage and cell fusion inhibition at the end of the replication process (Xu et al., ). Schefflera heptaphylla-derived dicaffeoylquinic acids also hindered RSV replication (Li et al., 2005b). The ethanol extract of Lophatherum gracile suppressed RSV infection and inflammation prompted in a dose-dependent manner (Chen et al., ).

4.8 Rotavirus and medicinal plants

Rotavirus is the common cause of chronic gastroenteritis in infants and young children across the globe. It is a paramount public health concern in low-income countries and massive morbidity and mortality rates in advanced nations (Parashar et al., ). The genus of rotavirus consists of nine species (A to I), but the only rotavirus A tends to cause more than 90% of human rotavirus infections (Kirkwood, ). The rotavirus's genetic material consists of 11 dsRNA segments that code for six structural and six nonstructural proteins. Structural proteins form the rotavirus particle called VP1, VP2, VP3, VP4, VP6, and VP7 premised on their molecular weight. Besides, nonstructural proteins are only produced during cell infection and are called NSP1, NSP2, NSP3, NSP4, NSP5, and NSP. Rotavirus afflicts intestinal cells and causes gastroenteritis; even so, the disease is not restricted to the gastrointestinal tract, and systemic viral transmission has been extensively illustrated (Ramig, ; Rivero-Calle et al., ).

While there is no particular antiviral drug for rotavirus, several other preventative actions like environmental hygiene and safe food and water can reduce the risk of rotavirus infection (Brown et al., ). The U.S. Food and Drug Administration (FDA) certified two subsequent oral attenuated vaccines as an efficient way to prevent rotavirus pandemics. The RotaTeq (Merck), a pentavalent human-bovine vaccine is comprising four rotavirus strains generated by recombination and Rotarix (GlaxoSmithKline), a monovalent human rotavirus vaccine that included one G1P-specific rotavirus strain (Desai et al., ; Gurgel et al., 2011). Hence, alternative safe therapies for rotavirus infections have become the subject of ongoing research (Alfajaro et al., ). Pinus koraiensis, Lomatium dissectum, Artocarpus integrifolia, Myristica fragrans, Spongias lutea, Tylosema esculentum, Byrsonima verbascifolia, Myracrodruon urundeuva Allemão, Eugenia dysenterica, Hymenaea courbaril, and Achillea kellalensis were reported to hinders rotaviral strains (Cecílio et al. ; Chingwaru et al. ; Gandhi et al., ; Goncalves et al., ; Taherkhani et al., ) (Table 4). The active ingredients have not yet been isolated and characterized from the above-described plant species. Further, chemical investigations are needed to explore plant species' chemical compounds in mass quantities and display more inhibitory effects toward rotavirus than that of the extract.

Plant name/Active compounds

Virus strain assessed

Test dose

Culture/Animal model assessed

Proposed mechanism

References

Epigallocatechin gallate and theaflavin digallate (green tea)

Human rotavirus (Wa)

IC ₅₀ 125 μg/ml to 250 μg/ml

MA-104 cells

Interfered with virus adsorption

Mukoyama et al., 1991b

Lomatium dissectum Nutt.

Bovine rotavirus)

Dilutions ranging from 1 × 10-l through 1 × l0 −7 of 0.2 ml of extract

MA-104 cells

Inhibited virus induced CPE

McCutcheon et al., 1995

Hesperidin and neohesperidin ( Citrus aurantium Linn.)

Human rotavirus (Wa)

IC ₅₀ 0.05 mg/ml, 10 μM/ml and 25 μM/ml

MA-104 cells

Hesperidin and neohesperidin exhibited inhibitory effect on rotavirus infection

Kim et al., 2000

Stevian ( Stevia rebaudiana)

Human rotavirus strains and SA-11

EC ₅₀ 431-492 μg/ml

MA-104 cells

Inhibitory activity against the replication of four serotypes of human rotavirus (HRV) and inhibited the binding of VP7 to the infected cells

Takahashi et al., 2001

Stevia rebaudiana Bertoni.

Human rotavirus and SA-11

EC ₅₀ 32-153 μg/ml

MA-104 cells

Inhibitory activity against the virus replication and binding of viral proteins VP7 not VP4 to the infected cells

Takahashi et al., 2001

Artocarpus integrifolia Linn. Myristica fragrans Houtt. and Spongias lutea Linn.

SA-11 and Human (HCR3) rotaviruses in MA-104 cells

(480 μg/ml), (160 μg/ml) and (40 μg/ml)

MA-104 cells

Antiviral activity against both the viruses

280 natural compounds

Rotaviruses

IC ₅₀ 7.5 μg/ml

MA-104 cells

18-β-glycyrrhetinic acid, abietic acid, alltrans-retinoic acid, and mangostin reduced the virus replication as well induced the cell signaling pathways involved in antiviral and inflammatory gene expressions

Shaneyfelt et al., 2006

Pectic polysaccharides (Panax ginseng C.A. Mey)

IC ₅₀ (15 and 10) μg/m

Human rotavirus (Wa)

MA-104 cells

Protecting cell viability from rotavirus-induced infection. It possibly allievated virus proliferation in cells

Polyphenols ( Glycyrrhiza uralensis Fisch)

EC ₅₀ of polyphenols were 18.7-69.5 μM against G5P[7] and 14.7-88.1 μM against G8P[7]

Bovine rotavirus G8P[7] and porcine rotavirus G5P[7]

Fetal rhesus Monkey kidney (TF-104) cells

Licocoumarone, licoflavonol, glyasperin D and 2′-methoxyisoliquiritigenin showed inhibition viral absorption, viral replication, and viral RNA synthesis

Kwon et al., 2010

Nelumbo nucifera Gaertn. Aspalathus linearis, Urtica dioica Linn.Glycyrrhiza glabra Linn. and Olea europaea Linn.

SA-11 and the Rhesus rotavirus Strain

IC ₅₀  < 300 μg/ml

MA-104 cells

Exerted antiviral activities and has no positive effect on the maintenance of trans-epithelial resistance

Alpinia katsumadai
Bovine G8P(7) and porcine G5P(7]) rotaviruses

EC ₅₀ 0.7 ± 0.4 to 33.7 ± 6.5 μg/ml against G5P(7) strainEC ₅₀ 8.4 ± 2.2μg/ml, 6.5 ± 0.8μg/ml, and 8.4 ± 5.0 μg/ml against G8P(7) strain

MA-104 cells

Blocked viral adsorption

Kim et al., 2012

Achillea kellalensis Boiss.

Bovine rotavirus

EC ₅₀ 100 μg/ml

MA-104 cells

Prevented viral replication and inhibited the viral CPE

Rice bran ( Oryza sativa Linn.)

Human rotavirus(VirHRV)Wa strain(G1P1A[8])

10% of the pigs total daily calorie

Neonatal gnotobotic pigs

Rice bran promoted thedevelopment of IFN-T cell responses, total IgM IgSCs in ileum and spleen, total IgA IgSCs in spleen and blood, and total serum IgM, IgA, and IgG

antibody production

Yang et al., 2014

Achillea fragrantissima Linn. Nitraria retusa (Forssk.) Asch

Human rotavirus (Wa) strain

IC ₅₀ 1.0-1.2 mg/ml and IC ₅₀ 0.9-1.4 mg/ml

MA-104 cells

Reduced viral titres against rotavirus

α-Glucosyl hesperitin and epigallocatechin gallate

SA-11

100 × 10 ³  μg/ml nd 80, 160, and 320 μg/ml

MA-104 cells

Loss of viral capsid protein

Genistein

Human rotavirus (Wa) and SA-11 strain

>160 μM

MA-104 human epithelial colorectal (Caco2) cells

Genistein inhibited rotavirus replication by upregulating AQP4 expression via the cAMP/PKA/CREB signaling pathway

Resveratrol, Piceatannol, Trans-arachidin-1 and Transarachidin-3

SA-11

10-20 μM

Human adenocarcinoma intestinal cell lines (HT29 FT8) and MA-104 cells

Two stilbenoids, trans-arachidin-1 and transarachidin-3 showed therapeutic potential against rotavirus replication via downregulating NSP4 protein levels

Aegle marmelos, Quillaja saponaria, Psidium guajava, Nelumbo nucifera, Aspalathus linearis, Urtica dioica, G. glabra, Olea europaea, Achyrocline bogotensis, Eucalyptus camaldulensis, Achillea fragrantissima, Nitraria retusa; Rindera lanata, and Euphorbia hirta were reported as novel antiviral candidates toward rotavirus infection. They interfere with virus absorption, inhibits virus replication, and reduces the levels of virus titers (Birdi et al., ; Brijesh et al., ; Civra et al., ; El-Baz et al., ; Knipping et al., ; Mohamed et al., ; Pilau et al., ; Roner et al., ; Téllez, Téllez, Vélez, & Ulloa, ). Besides, Vaccinium macrocarpon, Vitis labrusca, and Myracrodruon urundeuva (Cecílio et al., ; Lipson et al. , , ) decreases the level of external viral capsid proteins and influences the virulence of rotavirus. Similarly, bioactive compounds such as licocoumarone, licoflavonol, glyasperin D and 2′-methoxyisoliquiritigenin, carvacrol, 18β-glycyrrhetinic acid, luteolin, vitexin, apigenin-7-O-glucoside, and tannins from Diospyros kaki (Ebenaceae) inhibits the rotavirus infection of MA-104. Similarly, epigallocatechin gallate, theaflavin digallate, genistein, hesperidin, neohesperidin, diosmin, pectic polysaccharides isolated from the Panax ginseng; abietic acid, all-trans-retinoic acid, mangostin, α-glucosyl hesperidin, proanthocyanidins from Vaccinium macrocarpon and V. labrusca; resveratrol, piceatannol, trans-arachidin-1 and trans-arachidin-3, from Arachis hypogaea inhibited infections of fetal rhesus monkey kidney (TF-104), human epithelial colorectal (Caco-2), and human adenocarcinoma intestinal (HT29.F8) rotaviruses cultured cells (Baek et al., ; Ball et al., ; Gandhi et al., ; Hardy et al., ; H. Huang et al., ; Lipson et al., ; Pilau et al., ; Savi et al., ).

4.9 CV and medicinal plants

Unfortunately, hardly any vaccine or effective antibiotic treatments are presently available to avoid CV infections. However, natural ingredients, herbs, and traditional decoctions showed CV-infection therapy (Table 3). A study performed on 76 patients treated with Sophora spp. extract reported that RNA clearance of Coxsacki B virus was dose-dependent, and all patients displayed relief from arrhythmia, improved cardiac output, stroke volume, and cardiac index showed progress. The left ventricular mass and its index diminished expressively. The anti-Coxsackie antibody returns to the average titer after 5-months of treatment (Li, ).

Aqueous, ethanol extract and bioactive compounds, such as linalool, apigenin, and ursolic acid from Ocimum basilicum (sweet basil) reported antiviral activity against CVB1. In particular, Ursolic acid interacts with post-infection replication of CVB1 (Chiang et al., ). Further, Bupleurum kaoi was known to inhibit CVB1 infection by activating type I interferon response (Cheng et al., 2006b; Cheng et al., ). Raoulic acid from Raoulia australis was determined as an antiviral informant against many CVB subtypes; however, the mechanism for its influence is uncertain (Choi et al., ). Rheum palmatum (Polygonaceae) against CV B3 in vitro and in vivo showed inhibitory effects on HEp-2 cells. Extract-treated mice showed improved survival rate, reduced clinical symptoms, and lowered viral titers. The whole study demonstrates that interferon inducers of type I could be useful in maintaining CVB infection and could be further analyzed as a therapeutic intervention (Xiong et al., ). Besides, extracts of Dodonaea viscosa leaves displayed a therapeutic efficacy ranging from 0.3 to 25 with a reduction in virus titer ranging from 0.25 to 5 log10 TCID 50/0.1 ml against coxackievirus B3 (CVB3) infections. Crude extract provided significant inhibition of CVB3 replication by attaching to the viral capsid of CVB3, and prevents the virus from accessing host cells (Shaheen et al., ). Cornus officinalis, Acer triflorum, Pulsatilla koreana, and Clematis heracleifolia var. Davidiana Hemsl extracts showed significant antiviral activity toward CVA16 (Song et al., ). Isatindolignanoside A, a glucosidic indole-lignan isolated from aqueous root extract of Isatis indigotica revealed antiviral activity against CVB3 CVB3, with IC ₅₀ and SI values of 25.9 μM and >3.9, respectively (Meng et al., 2018).

4.10 Dengue virus and medicinal plants

DENV is an encased positive sensory ssRNA virus of the Flaviviridae family. The DENV is transferred particularly by mosquito bites of Aedes aegypti and is an influential arbovirus in Southeast Asia (Black et al., ). However, most of the four virus serotypes (DENV 1-4), could trigger dengue fever (Back & Lundkvist, ). Clinical symptoms of DENV infection include evident/mild febrile exposure, contemporary dengue fever (fever, headache, myalgia, joint pain, nausea, vomiting, and skin rash), and life-threatening hemorrhage diseases, explicitly dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) (Sam et al., ). Although this is an obsolete viral infection, current vaccination and treatment interventions accessible to prevent and control DENV infection are minimal. The management of dengue-related illnesses entails mosquito-controlled viral infection prevention and the alleviation of infected patients' symptoms.

Developing preventative/pharmacological intervention for DENV infection with natural ingredients could resolve these practical limits. Quite a few natural compounds, like quercetin and narasin, and marine algae derivatives exhibit robust anti-DENV features (Zandi et al., ; Low et al., ; Koishi et al., ) (Table 3). For example, Flavone baicalein shows inhibitory activities against DENV adsorption to host and post-entry viral replication (Zandi et al., ). Also, chebulagic acid and punicalagin, extracted from Terminalia chebula, have a broad array of antiviral agents against the viruses (Lin et al., ). They will effectively inactivate free DENV particles and tamper with attachment and fusion incidents throughout the early viral entry. Nordihydroguaiaretic acid extracted from the leaves of Larrea tridentata (Zygophyllaceae) was found to hinder the replication of the linked DENV by approaching genome replication and viral assembly (Soto et al., 2014).

In contrast, flavonoids are the inhibitors of NS2B-NS3 serotype 2 and 3 DENV proteases with IC ₅₀ values ranging from 15 to 44 μM. Myricetin is non-competitive serotype 2 NS2B-NS3 protease inhibitor with Ki values of 11 and 4.7 μM, respectively (Sousa et al., 2015). Ethanol extracts of Cassia grandis leaves, and Tabernaemontana cymosa bark toward two DENV serotype 2 strains DENV-2/NG and DENV-2/16681 in VERO, and U937 cells hinders viral replication and significantly impact viral internalization (Hernández-Castroa, Diaz-Castillo, & Martínez-Gutierrez, ). The recognition of such natural viral inhibitors may help in building anti-DENV therapy and lower DHF/DSS risk. Schisandrin A extracted from Schisandra chinensis hinders DENV replication by up-regulation of antiviral interferon responses through STAT signaling pathway (Yu et al., 2017).

4.11 MV and medicinal plants

MV is an encased negative-sense ssRNA virus of the Morbillivirus gene (Family: Paramyxoviridae). MV induces measles (an acute respiratory infection characterized by fever, conjunctivitis, coughing, runny nose, and nausea), and a generalized red macular rash across the body resulting in pneumonia encephalitis (Sabella, ). Although extremely infectious by interaction with respiratory secretions or airborne particulates, immunotherapies toward measles were described as a three-part MMR vaccine (measles, mumps, and rubella). Despite an effective MV vaccine, the virus remains a vital assassin for children in the developing world (Clements & Cutts, ; Murray & Lopez, ). A severe further aspect is a resurgence of measles in vaccinated populations and non-immunized individuals (Mossong & Muller, ; Zandotti et al., ). Such problems highlight MV's medical significance and the need to develop appropriate drug therapies.

Natural products from East and South-east Asian medicinal plants (Kurokawa et al., ), the herbal decoction (Huang et al., ), the Cherokee remedy spicebush (McWhorter, ), plant bioflavonoid isolated from Rhus succedanea and Garcinia multiflora (Lin et al., ), calcium spirulan from the blue-green alga Spirulina platensis (Hayashi et al., ) and several Rwandan and Ugandan medicinal plant extracts were reported to inhibit MV infection (Cos et al., ) (Table 3). In contrast, certain Olinia rochetiana (Olkirenyi) and Warburgia ugandensis (Osokonoi) typical dietary herbal additives were demonstrated to suppress in vitro MV infection (Parker et al., ). Another example is the Cajanus cajan extracts recommended to have anti-MV activity, though their bioactive components remain unknown (Nwodo et al., ). The chebulagic acid and punicalagin tannins showed potent efficacy against MV infection, mainly by inhibiting the virus particles, disrupting the attachment and fusion stages throughout viral entry (Lin et al., ). Therefore, they could serve as potential entry inhibitors to MV.

5 CONCLUSION AND FUTURE PERSPECTIVES

Antiviral drug production is a concern, as enzymes do not behave like normal living cells and antiviral medications could only deter replication of viruses or inhibit deeper inflammation. Accordingly, plant extracts/botanically derived compounds were documented with potential antiviral activity in cell line and animal model studies. Intriguingly, different mechanisms were established for these compounds, among which virucidal behavior is the most prevalent. Other confirmed exercises include hindering virus entrance into target cells, inhibiting viral protein expressions like 3CLpro, PLpro, S, and ACE2, and interfering with viral DNA replication, all of which are essential prerequisites constructing individual viral particles. Besides, the introduction of high-throughput technologies and traditional medicines together might play a critical role in assessing potential plant-derived substances for innovative discovery in contemporary drug development. They compete against viral diseases but have a long way to go before final use in the clinic to compensate for exploration, isolation, and mechanistic studies. Given the broad diversity of bioactive molecules derived from plants, a reliable, relentless, and constant approach is necessary to pursue unidentified bioactive molecules with potent antiviral activity, particularly relative to the risk posed by pathogenic viruses to enhance resistance to antibiotics. Many natural products like lycorine, homoharringtonine, silvestrol, ouabain, tylophorine glycyrrhetinic acid, acetoxime, and caffeic acid chebulagic acid, punicalagine and 7-methoxycryptopleurine possess significant antiviral activity even in the nanomolar concentration and will be better candidates for novel drug discovery. However, it requires further research to demonstrate the mechanism of secondary metabolites' action in an in vivo and invitr o model.

In contrast, many natural products with good antiviral activity are the essential components of some traditional food additives that could strengthen the wider public's immune system in inevitable outbreaks. Further, research must entertain therapeutic agents' feasibility with several other natural sources or with existing drugs, as the multi-target treatment mitigating the chances of drug-resistant viruses being developed. Therefore, comprehensive research in the forthcoming could recognize the possible antiviral molecules and understand their mechanism of action to stabilize such fatal viruses more appropriately.

CONFLICT OF INTEREST

The authors declare no conflicts of interest.

Abstract

The pandemic of viral diseases like novel coronavirus (2019-nCoV) prompted the scientific world to examine antiviral bioactive compounds rather than nucleic acid analogous, protease inhibitors, or other toxic synthetic molecules. The emerging viral infections significantly associated with 2019-nCoV have challenged humanity's survival. Further, there is a constant emergence of new resistant viral strains that demand novel antiviral agents with fewer side effects and cell toxicity. Despite significant progress made in immunization and regenerative medicine, numerous viruses still lack prophylactic vaccines and specific antiviral treatments that are so often influenced by the generation of viral escape mutants. Of importance, medicinal herbs offer a wide variety of therapeutic antiviral chemotypes that can inhibit viral replication by preventing viral adsorption, adhering to cell receptors, inhibiting virus penetration in the host cell, and competing for pathways of activation of intracellular signals. The present review will comprehensively summarize the promising antiviral activities of medicinal plants and their bioactive molecules. Furthermore, it will elucidate their mechanism of action and possible implications in the treatment/prevention of viral diseases even when their mechanism of action is not fully understood, which could serve as the base for the future development of novel or complementary antiviral treatments.

1 INTRODUCTION

Among all the numerous outbreaks of infectious diseases confronted by humankind, it's indeed the viral infections that are undoubtedly the biggest pandemic threat in the recent era. The replication patterns and viral modes of transmission are the main determinants underpinning this assault. A wide-spectrum antiviral agent's inadequacy plays a pivotal role (Center for Health Security, ). Viruses need to use host cell machines for several functions. Therefore, their obligatory parasitic nature and antiviral approaches must be applied directly to a virus to minimize interference with the host cell functions (Adalja & Inglesby, ).

Further, the virus acts as barriers to broad-spectrum antiviral agents, including distinctions among RNA and DNA viruses, completely distinct virally encoded proteins, single or double genomic structure, cycles of cytoplasmic or nuclear replication, and degree of dependence on host proteins (Schoeman & Fielding, ). The global antiviral drug armamentarium is expanding exponentially and is now covering many viral families. Nonetheless, very few known antiviral agents have activity spectrums that even marginally match up to the penicillin or sulfa range, the very first antibacterial agents identified.

The Earth's planet constitutes approximately 1,031 viruses, and their pervasiveness has colonized the marine ecosystem, where about 5,000 viral genomes seem to be prevalent in every 200 L of water (Breitbart & Rohwer, ). Also, viruses continue moving between the environments. They are available worldwide, for example, in deep Ocean, polar ices, alkaline, hot, and salt waters, and are about 2,000 m deep in the terrestrial ecosystem. There have been nearly 20 families of viruses that certainly infect humans (Harvey, Champe, Fisher, & Strohl, ), and many of them also trigger diseases in animals (Mahzounieh, Moghtadaei, & Zahraei Salehi, ). Virus particles contact the living system, and if they inundate the human immune response, then preventing their expansion in the body would be almost unfeasible. For the sake of their frequent replication, they control the host biochemical pathway/metabolic processes and make their treatment almost tricky. However, it is now well comprehended that viruses are specific in their replication mode that could be effectively approached (Syed, Amako, & Siddiqui, ). For instance, the proteolytic enzyme enhances viral maturation by distinguishing the viral polyprotein predecessor, whose obstruction would prevent its growth (Wapling, Srivastava, Shehu-Xhilaga, & Tachedjian, ). The epidemic outbreaks caused by emerging and re-emerging viruses represent a critical threat to public health, mainly when preventive vaccines and antiviral therapies are unavailable. Several hard-to-cure diseases and complex syndromes, including Alzheimer's disease, type 1 diabetes, and hepatocellular carcinoma (HCC), have also been associated with viral infection (M. J. Ball, Lukiw, Kammerman, & Hill, ; Hober et al., ; Morgan et al., ). However, many viruses remain without adequate immunization and, only a few antiviral drugs are licensed for clinical practice. The situation is further exacerbated by drug-resistant mutants' especially when using viral enzyme-specific inhibitors, which significantly hampers drug efficacy (Geretti, Armenia, & Ceccherini, ; Locarnini & Yuen, ). Hence, there is an urgent need to discover novel antivirals that are highly productive and cost-effective for managing and controlling viral infections when vaccines and standard therapies lack.

New viral infections needed quite advanced drug molecules; however, the process of establishing such approaches toward this moment seems to have been sluggish and filled with impediments (Desselberg, ). Antiviral chemotherapy has proceeded at a snail-like pace, unlike antibiotics that had attained a specific treatment level in three decades. Nevertheless, it ended up taking nearly 60 years for antiviral development to achieve its current prevalence position. The evolution of diagnosis for Hepatitis C is a prime illustration of how complicated the antiviral effect can be. However, cumulative and aimed antiviral therapy has proven to be an excellent strategy for treating viral infectious disease.

Viruses are amongst the substantial causes of mortality and morbidity globally (GBD 2017 Disease and Injury Incidence and Prevalence Collaborators, ; WHO, ). Antiviral drugs and vaccines are being used to control human viral infections (De Clercq & Li, ). Eventually, the main focus was on "one drug, one virus" dogma, which depends solely on targeting virus-specific factors. A counterstatement to this is "one drug multiple viruses" (BSAAs), as viruses utilize similar pathways and host factors to replicate within a cell (Bekerman & Einav, ; Bosl et al., ; de Clercq & Montgomery, ; De bing, Neyts, & Delang, ; Ianevski, Andersen, Merits, Bjoras, & Kainov, ; Rada & Dragun, 1977; Sidwell et al., ). Though the concept of BSAAs was about 50 years ago, due to the recent outbreaks of a novel coronavirus (2019-nCoV) and several other viral infections, the field has acquired new urgency for the discovery of novel host-directed agents and the expansion of a drug repositioning methodology (Paraskevis et al., ).

Drug repurposing, also known as repositioning, redirecting, reprofiling, is a strategic approach for accumulating additional benefits from an approved drug by approaching a disease apart from that it was initially envisioned (Nishimura & Hara, ; Pushpakom et al., ). It has distinct advantages over new drug discovery since chemical synthesis, manufacturing processes, reliable safety, and pharmacokinetic properties are accessible in pre-clinical and early clinical development phases. Consequently, the repositioning of launched or perhaps failed viral drugs offer incredible translational opportunities, such as a substantially higher probability of commercial success in comparison to the implementation of novel virus-specific medicines and vaccines and a substantially decreased cost and timeframe for clinical accessibility (Ianevski et al., ; Pizzorno, Padey, Terrier, & Rosa-Calatrava, ; Zheng, Sun, & Simeonov, ).

Antivirals are antimicrobial compounds derived from living organisms or generated by chemical synthesis, mostly hindering viral replication. Antivirals tamper with one or more phases of the viral life cycle, which include: cell attachment, cell penetration, viral uncoating, copy of the viral genome (DNA/RNA), maturation, and reveal of viral progeny and, are an essential tool to facilitate vaccine action (Veiga-Crespo, Viñas, & Villa, ). The synthesized antiviral drugs such as moroxydine, ganciclovir, valganciclovir, and valaciclovir were used to inhibit virus replication through various mechanisms (Biron, ). However, due to their low efficacy, cytotoxicity, and the development of viral resistance, difficulties in treating drugs arise. A further antiviral therapy, vaccination, may be used but is still under advancement because it often provides inadequate virus protection, and its validity needs further investigation (Subbarao & Joseph, ). Thus, more scientific research is required in the treatment of antiviral synthetic drugs and vaccines.

Nature has provided yet another credible source of antiviral agents, and almost 40% of the drugs available at the moment are directly or indirectly plant derivatives. A range of ethnobotanical studies focused on identifying possible therapeutic plants for even more effective management of healthcare issues, demonstrating the significance of medicinal plants in the healthcare deliveray system (Ansari & Inamdar, ; Appidi, Grierson, & Afolayan, ; Heneidy & Bidak, ; Ky et al., ; Makambila-Koubemba, Mbatchi, Ardid, Gelot, & Henrion, ; Shinwari & Khan, 2000). Herbal remedies and extracted natural products often provide a significant source of novel antiviral developing drugs. Antiviral medications' characterization from such natural sources sheds light on where they interrelate with the viral replication cycle, like viral entry, replication, assembly, and release, and the targeting of precise virus-host interactions. Here, we enumerate the antiviral activities of a range of natural products and herbal medicines against specific critical viral pathogens. This study aims to assess previously published antiviral plants and spot possible action mechanisms and substances accountable for their antiviral activity. A deeper understanding of the mode of action and evaluating the concerned compounds will provide a unique insight into the concept of new antiviral drugs for even more effective viral co-operation.

2 METHODOLOGY

An extensive review of the literature was carried out on antiviral medicinal plants and their associated bioactive compounds between 2019 and 2020 via electronic search Pubmed, Scopus, Web of Science, Science Direct, J-Gate, Google Scholar, and a library search for articles published in peer-reviewed journals. The unpublished materials have been excluded from this review. The review process was further continued by the refining of the search results using the keywords namely viral medicinal plants, antiviral bioactive compounds, emerging viral infections, novel coronavirus, coxsackievirus (CV), dengue virus (DENV), enterovirus 71, human herpes viruses, hepatitis virus, human immunodeficiency virus, influenza virus, measles virus (MV), respiratory syncytial virus (RSV), and rotavirus. The literature cited in the review dated from 1950 to 2020 and limited to the English language. The final data collected through the authors' discussions were then compiled, evaluated, compared, and drawn accordingly.

3 BASIC VIRAL STRUCTURE AND ITS PATHOBIOLOGY

Viruses are organic artifacts that are metabolically inactive outside the host and after accessing the host cell becomes activated (Dupre & O'Malley, ). They are comprised primarily of proteins and nucleic acid; the proteins contribute to their unique shape by forming a capsid (Andersson, ). Therefore, viruses are of different forms, like superficial, helical, icosahedral, or complex, and perhaps some viruses are accompanied by a lipid bilayer extrapolated from a host membrane called an envelope (Geng et al., ). Besides, capsid proteins associated with nucleic acids form nucleocapsids. Proteins related to viral nucleic acids are called nucleoproteins. Virus nucleic acid is either DNA or RNA and has been the elementary source of knowledge required to monitor its metabolic functions. This DNA and RNA are categorized based on the number of strands into single or double-stranded DNA/RNA (Firth et al., ; Pichlmair et al., ). The sense of strand can further differentiate single-stranded RNA viruses as some RNA viruses have a positive-sense RNA (+ve ssRNA), and some viruses have a negative-sense RNA (−ve ssRNA) (Gorbalenya, Enjuanes, Ziebuhr, & Snijder, ). Nucleic acid form (DNA/RNA) is indeed a vital point of differentiation since all viruses did not constitute the same nucleic acid pattern (Gao & Hu, ).

The multiplication of all viruses results from several sequential processes: adhesion of the virus to the cell surface, virus adsorption and entry into the cell, replication of viral nucleic acids, and expression of viral proteins, and release of virus particles from the cell. For example, the virus entrance process is often carried out by cell surface proteins; Hepatitis C virus (HCV) entry involves claudin-1, occludin, and tetraspanins as the primary receptor proteins (Burlone & Budkowska, ). The latter's accession is influenced by other lipoproteins and the enzyme lipoprotein lipase. Moreover, infection with the influenza virus is modulated by a protease enzyme that triggers the viral surface protein hemagglutinin (Zambon, ). The protease enzyme is pertinent for illustrating viral proteins; it categorizes proteins into groups based on everyone's structural and non-structural features (Appel, Schaller, Penin, & Bartenschlager, ). But RNA viruses require two powerful enzymes to sustain; reverse transcriptase and integrase, former transcribed viral RNA to DNA at the moment of replication (Briones, Dobard, & Chow, ; Sluis-Cremer & Tachedjian, ). In contrast, the second enzyme integrates viral DNA into the host genome and is required for the effective uncoating of virus-core proteins. As a result, the virus needs enzymatic and non-enzymatic proteins to stop its replication and infection.

4 ANTIVIRAL MOLECULES OF PLANT ORIGIN

Conventional medicine is indeed a worthwhile line of study for analyzing, extracting, and developing medicinal benefits. Conversely, a relatively small proportion of bioactive compounds were studied systematically for their therapeutic uses. Natural products include an unusual approach to exploring antiviral agents with remarkable pharmacological properties (Cragg & Newman, ; Atanasov et al., ). Herbal therapists have been using traditional plants since prehistoric days to cure diseases in humans and animals, particularly in the Asia-Pacific region. People continue to rely on medicinal herbs and their products for their wellness and primary medical care throughout the globe (Ekor, ). About 2,500 natural plant species are listed globally to diagnose many diseases and illnesses (Kapoor, Sharma, & Kanwar, ).

Collecting traditional data from local or indigenous communities or even using important ethnopharmacology plant(s) to extract bioactive molecules/phytochemicals is a very demanding approach for diagnosing different ailments (Altemimi, Lakhssassi, Baharlouei, Watson, & Lightfoot, ). Numerous aspects, including the various solvents (polar, non-polar) used during the extraction of bioactive constituents and the selection of plant parts/tissue for their extraction from plants, commonly play a crucial role (Ben-Shabat, Yarmolinsky, Porat, & Dahan, ). A holistic approach for isolating and characterizing bioactive molecules and virus replication inhibitory experiments in animal cell systems is required when such bioactive molecules could be used to cure a viral infection (Kapoor et al., ). The eternal objective of establishing high throughput screening assays is just the way to recognize bioactive molecules/phytochemicals from large chemical libraries quickly and accurately. In vivo experiments and consequent clinical studies are necessary to identify the antiviral activity and severe complications like reactogenicity or toxicity of purified bioactive molecules.

4.1 Coronavirus and medicinal plants

There have been no specific treatments for CoV infection, and preventive vaccines are still under examination. It illustrates the need to implement new antivirals for prophylaxis and treatment of CoV infection. The complete list of the potent plant extracts and their bioactive compounds that inhibit coronavirus are depicted in Table 1. Ginsenoside Rb1 (Gynosaponin C), one of the bioactive ginsenosides extrapolated from Panax ginseng, displayed antiviral activity (Wu et al., ). Tetra-O-galloyl-beta-d-glucose, luteolin, and tetra-O-galloyl-beta-d-glucose, blocked the SARS-CoV host cell entry (Yi et al., ). Chinese herbs have long been known for their antiviral effects and therefore examined for SARS-CoV's potential role. Of the 200 herbal extracts analyzed, Lycoris radiata, Artemisia annua, Pyrrosia lingua, and Lindera aggregata seemed to have an anti-SARS-CoV impact with a 50% effective aa(EC ₅₀) of 2.4-88.2 μg/ml (Li et al., 2005a). Additionally, tannic acid, 3-isotheaflavin-3-gallate, and theaflavin-3,3′-digallate, three black tea phenolics, collectively, exhibited inhibitory effects SARS-CoV 3CLpro with IC ₅₀ values of 3, 7, and 9, 5 μM, respectively (Chen et al., ). On the other hand, phenolic compounds from Isatis indigotica showed an inhibitory effect against SARS-CoV 3CLpro with IC ₅₀ values of 217, 752, 8.3, 365, and 1,210 μM, respectively for sinigrine, indigo, aloe emodin, hesperetine, and β-sitosterol (Lin et al., ).

Natural product(s) evaluated

Test system

Test dose

Proposed mechanism

References

Extract ( Rheum officinale Baill., Polygonum multiflorum Thunb.)

SARS-CoV spike (S) Protein

0-100 μg/ml

Inhibits the interaction of SARS-CoV S protein and ACE2

Ho, Wu, Chen, Li, & Hsiang, 2007

Herbal extracts ( Gentiana scabra, Dioscorea batatas, Cassia tora, Taxillus chinensis, Cibotium barometz)

SARS-CoV

25-200 μg/ml

3CL protease inhibition

Anthemis hyalina, Nigella sativa, and Citrus sinensis Extracts

SARS-CoV

1/50 and 1/100 dilution of ethanolic (100 g/200 ml)

Increased IL-8 level.

Significantly changed the expression of TRPA1, TRPC4, TRPM6, TRPM7, TRPM8, and TRPV4 genes

Natural product(s) evaluated

Test system

Dose/concentration

Proposed mechanism(s)

References

Extract ( Rheum officinale Baill., Polygonum multiflorum Thunb.)

SARS-CoV spike (S) protein

0-100 μg/ml

Inhibits the interaction of SARS-CoV S protein and ACE2.

Ho et al., 2007

Herbal extracts ( Gentiana scabra, Dioscorea batatas, Cassia tora, Taxillus chinensis, Cibotium barometz)

SARS-CoV

25-200 μg/ml

3CL protease inhibition

Anthemis hyalina, Nigella sativa, and Citrus sinensis

Extracts

SARS-CoV

1/50 and 1/100 dilution of ethanolic (100 g/200 ml)

Increased IL-8 level.

Significantly changed The expression of TRPA1, TRPC4, TRPM6, TRPM7, TRPM8, and TRPV4 genes

4′-O-methylbavachalcone and Neobavaisoflavone ( Psoralea corylifolia)

SARS-CoV

1-150 μM

Inhibitors of papain-like protease (PLpro)

Kim et al., 2014a

Mimulone, 3′-O-methyldiplacol, 4′-O-methyldiplacol, 3′-O-methyldiplacone, 4′-O-methyldiplacone ( Paulownia

Tomentosa)

SARS-CoV

0-100 μM

Inhibition of papain-like protease

Cho et al., 2013

7-Methoxycryptopleurine and Tylophorine

( Tylophora indica)

CoV-infected swine testicular cells

-

Inhibition of viral replication

Saikosaponins A, B ₂, C, D

HCoV-22E9

5-25 μM/L

Saikosaponin B ₂

inhibits viral attachment and penetration stages

Cheng et al., 2006

Tylophorin

CoV

0-100 μM

Targeting viral RNA replication and

Cellular JAK2 mediated dominant NF-κB activation

Yang et al., 2017

Scutellarein

SARS-CoV

0.01-10 μM

3CL protease inhibition

Yu et al., 2012

Silvestrol

HCoV-229E

0.6-2 μM

Inhibition of cap-dependent viral mRNA translation

Muller et al., 2018

Saikosaponins (A, B2, C, and D), naturally occurring triterpene glycosides obtained from Bupleurum spp., Heteromorpha spp., and Scrophularia scorodonia, exhibited antiviral activity against HCoV-22E9. Saikosaponin A, B2, C, and D have efficacy toward human CoV-229E, with EC ₅₀ values of 8.6, 1.7, 19.9, and 13.2 μM, respectively; saikosaponin B2 subdued viral attachment and penetration stages (Cheng et al., 2006a). These natural compounds effectively avoid the initial stage of HCoV-22E9 infection, like viral attachment and penetration, following co-challenge with the virus. In contrast, Rheum officinale, Polygonum multiflorum, and emodin have been investigated and proven to suppress SARS-CoV (S) protein and ACE2 interaction with IC ₅₀ valuesHo et al., 2007). Among 221 phytochemicals studied against SARS-CoV, 10 diterpenes, two sesquiterpenes, two triterpenes, and five lignans curcumin exhibited inhibitory effects at 3-10 μM concentration (Wen et al., ).

Interestingly, psoralidin showed a strong protease inhibitor influence on SARS-CoV with an IC ₅₀ value of 4.2 μM. Simultaneously, emodin, rhein, and chrysin hindered SARS-CoV (S) and ACE2 protein-protein interaction at 0-400 μM (T. Y. Ho et al., 2007; Kim et al., 2007). Conversely, ferruginol, 8β-hydroxyabieta-9(11),13-dien-12-one, 3β,12-diacetoxyabieta-6,8,11,13-tetraene, betulonic acid, betulinic acid, hinokinin, savinine, and curcumin inhibits replication of SARS-CoV at 0-80 μM (Wen et al., ). Other natural anti-CoV molecules include water extract from Houttuynia cordata, which displayed antiviral mechanisms against SARS-CoV, such as viral 3CL protease inhibition and viral RNA-dependent polymerase activity blockage (Lau et al., ). In the same way, Toona sinensis aqueous leaf extract inhibited SARS-CoV replication with EC ₅₀ values ranging from 30 to 40 μg/ml and SI values ranging from 12 to 17 (Chen et al., ). Procyanidin A2, procyanidin B1, and cinnamon tannin B1, extracted from Cinnamomi cortex, also hindered SARS-CoV infection at 0-500 μM (Zhuang et al., ).

Flavones and biflavones isolated from Torreya nucifera exude cytotoxic effect on SARS-CoV 3CLpro (Ryu et al., ), and Tylophorin and 7-methoxycryptopleurine isolated from Tylophora indica inhibit both N and S protein function and viral replication of enteropathogenic coronavirus transmissible gastroenteritis virus (Yang et al., ). Such molecules showed incredible antiviral activity with IC ₅₀ values of 0.018 and <0.005 μM, respectively. Tylophorine and 7-methoxycryptopleurine separated from T. indica have been shown to impede viral replication in coV-infected swine testicular cells (Yang et al., ). Six plant extracts ( Gentiana scabra, Dioscorea batatatas, Cassia tora, Taxillus chinensis, Cibotium barometz) asserted inhibitory effect against SARS-CoV 3CLpro with IC ₅₀ values of 39 and 44 μg/ml, respectively (Wen et al., ). Besides, diterpenoid, 8b-hydroxyabieta-9 (11), 13-dien-12-one, and lignin, savinin were reported to prevent SARS-CoV 3CLpro activity with a SI >667. In comparison, betulinic acid and savinin were found competitive inhibitors of SARS-CoV 3CLpro with Ki values of 8.2 and 9.1 μM, respectively. Tanshinones (e.g., tanshinone I, rosmariquinone) derived from Salvia miltiorrhiza also hindered infection and replication of SARS-CoV 3CLpro and PLpro at 1-1000 μM (Park et al., ). Further, myricetine and scutellarein exert an inhibitory effect of 0.01-10 μM for SARS-CoV 3CLpro (Yu et al., ). Likewise, (−) catechin gallate and (−)-gallocatechin gallate at 0.001-1 μg/ml prevented SARS-CoV nanoparticle RNA oligonucleotide (Roh, 2012).

Further, Eckol, 7-phloroeckol, phlorofucofuroeckoln, and dieckol segregated from Ecklonia cava obstructed virus adhesion to porcine epidemic cells at 1-200 μM with IC ₅₀ values of 22.5, 18.6, 12.2, and 14.6 μM, respectively (Kwon et al., ). Similarly, tomentine A, B, C, D, and E, 3′-O-methyldiplacol, 4′-O-methyldiplacol, 3′-O-methyldiplacone, 4′-O-methyldiplacone, mimulone, diplacone, and 6-geranyl-4′,5,7-trihydroxy-3′,5′-dimethoxyflavanone isolated from Paulownia tomentosa have been reported to suppress SARS-CoV PLpro at 0-100 μM (Cho et al., 2013). Anthemis hyalina, Nigella sativa, and Citrus sinensis extracts significantly reduced viral infection after HeLa-CEACAM1a (HeLa-epithelial carcinoembryonic antigen-related cell adhesion molecule 1a) has been afflicted with MHV-A59 (Mous Hepatitis Virus - A59) CoV, with A. hyalin being the most effective of the three plants assessed. Even though TRP gene expression was reduced upon diagnosis with these extracts, a rise in calcium ion level made it unconvincing to equate this impact with reduced viral replication (Ulasli et al., ). In another report, bavachinin, neobavaisoflavone, isobavachalcone, 4′-O-methylbavachalcone, psoralidin, and corylifol isolated from Psoralea corylifolia suppressed papain-like protease (Kim et al., 2014a). The investigation by Schwarz et al. (2014) noticed that juglanin prevents the SARS-CoV 3a channel with an IC ₅₀ value of 2.3 μM. Among the NIH clinical collection of 727 tested antiviral activity compounds against both murine and human coronavirus, alkaloid macetaxine (homoharringtonine) was perhaps the most effective (Cao, Forrest, & Zhang, ). On the other side, Quercetin, Quercetrin, Rutin, Cinanserin (1 and 2 dpi) isolated from H. cordata reported showed significant against CoV murine at 15.63-500 μg/ml (Chiow et al., 2016). Note that the SARS-CoV spike protein (S) uses ACE2 as a responsive binding site to invade host cells ( Li, ).

In contrast, broussochalcone B, broussochalcone A, 4-hydroxyisolonchocarpine, papyriflavonol A, 3′-(3-methylbut-2-enyl)-3′,4,7-trihydroxyflavane, kazinol A, broussoflavan A, kazinol F, and kazinol J extracted from Broussonetia papyrifera suppressed both SARS-CoV 3CLpro and PLpro, during which papyriflavonol A had the highest inhibition toward PLpro with an IC ₅₀ value of 3.7 μM (Park et al., ). Likewise, 7-methoxycryptopleurine (IC ₅₀: 20 nM) was much more efficient than tylophorine (IC50: 58 nM). In another investigation, tylophorine was also identified to approach viral replication of RNA and cellular JAK2-mediated dominant NF-ҟB activation in CoV at 0-1000 nM (Yang et al., 2017). In comparison, silvestrol impeded cap-dependent viral mRNA translation of HCoV-229E with an IC ₅₀ of 40 nM at 0.6-2 μM, and ouabain decreased both viral titers and viral yields and decreased the incidence of viral RNA copies at 0-3000 nM (Muller et al., 2018; Yang et al., 2020). New reports have shown that tetrandrin, fangchinoline, and cepharanthin, significantly inhibit initial phase viral-induced cell death in HCoV-OC43-infected human MRC-5 lung cells with IC ₅₀ values of 0.33, 1.01, and 0.83 μM, respectively (Kim et al., ). Also, lycorin, berbamine, emetin and mycophenolate mofetil were shown to intervene against HCoV-OC43, HCoV-NL63, MERS-CoV, and MHV-A59 at 0-5 μM. Lycorin and emetin suppressed cell division and hindered RNA, DNA, and protein synthesis, respectively while mycophenolate mofetil conferred an immune suppression effect on CoV species (Shen et al., ).

The docking studies analysis was used to examine the binding affinity and type of interaction among all compounds (67 natural molecules) and the target (Coronavirus (2019-nCoV) main protease). The outcomes of molecular modeling shown that among 67 molecules of biological origin crocin, digitoxigenin, and b-eudesmol act as inhibitors against the Coronavirus based on the energy types of interaction molecules (Aanouz et al., ). Also, 3CLpro sequence SARS-CoV-2 was assessed; its 3D homology model was developed and examined against a medicinal plant library containing 32,297 potential antiviral phytochemicals/Chinese traditional therapeutic molecules. Further, 5, 7, 3′, 4′-tetrahydroxy-2′-(3,3-dimethylallyl) isoflavone, myricitrin, methyl rosmarinate, (2S)-eriodictyol7-O-(600-Ogalloyl)-beta-d-glucopyranoside and calceolarioside B isolated from Psorothamnus arborescens, Myrica cerifera, Hyptis atrorubens Poit. Phyllanthus emblica and Fraxinus sieboldiana may act as anti-SARS-CoV-2 active compounds for more prioritization (Ul Qamar, Alqahtani, Alamri, & Chen, ).

4.2 Human herpes viruses and medicinal plants

Numerous members of the human herpesvirus (HHV) family are mostly causative factors for various human diseases. In contrast, many HHV infections are associated with Herpes Simplex Virus (HSV-1 and HSV-2). Other members of herpes viruses that cause multiple conditions are HHV-3 (Varicella-Zoster Virus), HHV-4 (Epstein Barr virus), HHV-5 (Cytomegalovirus), HHV-6, HHV-7, and HHV-8. HSV-1 and HSV-2 have encapsulated dsDNA viruses of the family Herpesviridae. HSV infection causes mucosal lesions in the ocular/perioral (usually HSV-1) and genital (usually HSV-2) areas and many other body sites. HSV tends to cause lifetime infection by developing itself on the sensory neurons and thus can be reactivated by different stimuli, like sun exposure, sore throat, immune suppression, menstrual cycles, or anxiety (Fatahzadeh & Schwartz, ). The transmission of HSV results from direct contact with infected lesions and could occur via vertical transmission from infected mother to fetus. However, the disease is typically self-limited and can be handled with antiviral drugs. However, consequences could develop in neonates, and immunosuppressed persons lead keratoconjunctivitis and life-threatening meningitis (Arduino et al., 2008; Chentoufi & Benmohamed, ).

Hardly any vaccine is recommended against HSV, even though there are no effective drugs that could neutralize innate HSV infection. A few primary and metastatic conditions could be monitored by analogous like acyclovir, penciclovir, and prodrugs. Moreover, the expansion of resistance to antibiotics virus is becoming a severe problem, especially in immune-compromised patients (Morfin & Thouvenot, ). Therefore, the discovery of new anti-HSV agents with diverse mechanisms is significant to HSV's clinical management. Plant extracts attracted substantial attention while looking for alternative compounds with anti-herpetic activity. Intriguingly, innumerable plant-derived extracts and molecules were already known to prevent HSV replication (Table 2) (Akram et al., ; Li et al., ).

Plant name

Natural product(s) evaluated

Virus assessed

Culture /Animal model assessed

Proposed mechanism

References

Labiatae and Verbenaceae families (essential oils)

Unknown

HSV-1 and HSV-2

In vitro

Virucidal, inhibition of viral binding, inhibition of viral entry

Aglaia odorata (Chinese perfume plant), Moringa oleifera (Moringa) and Ventilago denticulata

Unknown

HSV-1

In vivo

Inhibition after viral attachment

Lipipun et al., 2003

Houttuynia cordata (fish mint)

Quercitin, Isoquercitrin, and Quercitrin

HSV-1 and HSV-2

In vitro

Inhibition of NF-kB activation, inhibition of viral binding, inhibition of viral entry

Eucalyptus camaldulensis (River Red Gum)

Unknown

HSV-1 and HSV-2

In vitro

Inhibition before and after virus adsorption

Cassia stipulacea (Quebracho) and Escallonia illinita (Ñipa)

Unknown

HSV-1

In vitro

Inhibition after virus adsorption

Pacheco et al., 1993

Aristotelia chilensis (Chilean Wineberry), Drymis winteri (Winter's Bark), Elytropus chilensis (Quilmay) and Luma apiculata (Chilean Myrtle)

Unknown

HSV-2

In vitro

Inhibition after virus adsorption

Pacheco et al., 1993

Melaleuca alternifolia (tea tree)

Unknown

HSV-1 and HSV-2

In vitro

Inhibition of virus binding, inhibition of virus entry

Garozzo et al., 2009

Alpinia officinarum (Lesser Galangal) and Geum japonicum (Asian herb Bennet)

Unknown

HSV-1

In vitro

Inhibition after virus adsorption

Kurokawa et al., 1995

Paeonia suffruticosa (Mudan), Phellodendron amurense (Amur Cork tree), Polygala tenuifolia (Yuan Zhi), Polygonum cuspidatum (Asian Knotweed), Rhus javanica (Java Brucea), Syzygium aromaticum (clove), Terminalia arjuna (Arjun tree) and Terminalia chebula (Black Myrobalan)

Unknown

HSV-1

In vitro and in vivo

Inhibition after virusadsorption

Kurokawa et al., 1995

Licorice roots of Glycyrrhiza glabra were used to prepare a 2% topical acid cream, which contains carbenoxolone sodium. The cream was used to cure12 patients having acute oral herpetic (HSV) infections. The disease symptoms such as pain and dysphagia were resolved after applying the cream six times a day within a short span of 24-48 hr. In contrast, ulceration and lymphadenopathy were shown to cure steadily within 24-72 hr (Partridge & Poswillo, ). Samarangenin B extracted from the leaves of Limonium sinense observed suppression of HSV-1 α gene expression (Kuo et al., ). Further, Artocarpus lakoocha containing oxyresveratrol was reported to prevent early and late HSV-1 and HSV-2 viral replication phases, respectively (Chuanasa et al., ). Pterocarnin A compound isolated from Pterocarya stenoptera impeded HSV-2 from adhesion and infiltration to host cells (Cheng et al., ). Yatein extracted from Chamaecyparis obtuse substantially inhibits HSV-1 replication in HeLa cells without noticeable cytotoxic effects (Kuo et al., ).

In comparison, several H. cordata flavonoids were assessed to determine their capability to obstruct the HSV-2 replication cycle. The principal flavonoids quercetine, quercitrine, and isoquercitrine showed significant HSV-2 activity (Chen et al., ). Subsequent investigation assessed that the mode of action could be behind the anti-herpetic activity of H. cordata, like adsorption, entry, post-infection by NF-kB, and virucidal activity (Hung et al., ). Also, meliacin obtained from Melia azedarach was shown to induce TNF-α and IFN-α production and reduce HSV-2 by improving virus-induced pathogenesis in the mouse genital model of herpetic inflammation (Petrera & Coto, ).

Comparably, the aqueous extract from Rhododendron ferrugineum blackberry extract and the extract from Myrothamnus flabellifolia enriched with proanthocyanidin prevented the HSV-1 infection (Danaher et al., ; Gescher, Kuhn, Hafezi, et al., ; Gescher, Kuhn, Lorentzen, et al., ). Glucoevatromonoside, a cardenolide from Digitalis lanata, alter the cellular electrochemical gradient and hinder the proliferation of HSV-1 and HSV-2 in cells (Bertol et al., ). The natural products from the marine ecosystem such as algae and sponges produce active metabolites with anti-HSV activity (Sagar et al., ; Vo et al., ). Houttuynoids A-E extracted from H. cordata, showed effective anti-HSV-1 activity (Chen et al., 2012a). Another resveratrol compound isolated from the Veratum grandiflorum inhibited NF-kB activation, the primary bioactive substance present in grapes, peanuts, legumes, or other plant-derived matrices and perhaps in red wine (Chen et al., 2012b).

Numerous studies documented the antibacterial activity of resveratrol against the ACV-resistant and wild-type HSV-1 and HSV-2 replication cycles in cell lines and animal studies (Faith et al., ; Leyton et al., ). Compounds like spiroketalenol ether derivatives extracted from Tanacetum vulgare rhizome extract served as cell entry inhibitors and apprehend HSV-1 gC and HSV-2 gG glycoproteins production (Alvarez et al., ). Essential oils derived from Glechon spathulata and Glechon marifolia noted antiviral activity against HSV-1, which became effective after infecting Vero cells (Venturi et al., ). Furthermore, essential oils derived from plants of the families Labiatae and Verbenaceae have an antiviral effect on HSV. Vero cells after incubation with HSV and essential oils for 48-72 hr dramatically lowered viral titers of HSV-1 and HSV-2. It is important to note that their modes of action were related to the pre-infective stages (Brand et al., ). An analysis showed that the leaves of Morus alba L. exhibited antiviral properties against HSV-1 and HSV-2. Kuwanon X, a stilbene polyphenol derivative active compound found in this plant, reported antiviral activity against HSV at different phases of the infection process, preventing adsorption and penetration, and instant early and late gene expression of HSV-1, and replication of HSV-1 DNA (Ma et al., ).

Ethanolic extract from the Eucalyptus camaldulensis leaves prevents HSV-1 and HSV-2 infection during and after illness to Vero cells. Synergism was observed in cultured cells among acyclovir and ethanol extracts (Abu-Jafar & Mahmoud, ). Similarly, the antiviral activity of 24 new metabolites from the leaves of Eucalyptus sideroxylon and four new metabolites from genus Eucalyptus were reported. In contrast to HSV-1 and HSV-2 these compounds suppressed hepatitis A, coxsackie, and adenoviruses. Notably, antiviral activity against HSV-2 was exhibited by inhibiting the entrance of viruses and consequent infection processes (Okba et al., ). Xanthotoxin, bergapten, imperatorin, phellopterin, isoimperatorin, imperatorin, and phellopterin isolated from dichloromethane fruit extract of Angelica archangelica were explored as the practicable antiviral agents toward HSV l. Imperatorin and phellopterin showed the highest effect, minimizing replication of HSV-1 by 5.61 logs and 4.7 logs, respectively. The extract resulted in a decrease in the titer of the virus concerning the control of the virus. The findings demonstrate that coumarins of A. archangelica may be an excellent material for the formation of an alternative natural anti-HSV-1 compound (Rajtar et al., ).

Further, 12 compounds isolated from Eucalyptus globulus leaves and twigs were noticed to have antiviral efficacy against HSV-1 and HSV-2. Tereticornate A has been assessed to holds the most incredible action against HSV-1, relatively high than acyclovir. Cypellocarpin C showed significant antiviral activity against HSV-2, higher than that offered by acyclovir (Brezáni et al., ). Organic extracts relating to the Peganum harmala species showed antiviral activity against HSV-2 by disrupting virus entry (Benzekri et al., ). Besides, Yatein separated from C. obtuse prevents HSV-1 alpha gene expression, along with ICP0 and ICP4 expression of genes, by halting HSV-1 DNA replication and structural protein expression in HeLa cells ( Wang et al., ). Natural anti-HSV substances' availability should provide novel pharmacological properties against the virus for future use in monitoring HSV infections.

4.3 Medicinal plants in viral hepatitis

Viral hepatitis or inflammation of the liver is associated with several different viruses called hepatitis A, B, C, D, and E. Since exposure to any of these viruses results in acute infection, type B and C are distinctive in inducing chronic conditions.

4.3.1 Hepatitis B virus

Hepatitis B virus (HBV) a prototype virus belonging to Hepadnaviridae family, is an enveloped virus with a relaxed circular and partly double-stranded DNA genetic structure (dsDNA) (Liang, ). HBV induces hepatitis B and is transmitted by contact with the virus-containing blood or other body fluids. Though some spontaneous recovery following acute hepatitis B is prevalent, due to the extreme risk of cirrhosis, HCC therapy is advised for chronic infection. The HBV vaccine design and the national vaccination policy against hepatitis B in endemic regions like Taiwan have helped to alleviate HBV infection and decreased the prevalence of HCC in the childhood stage (Ni & Chen, ).

Given the availability of effective vaccinations, the existing HBV compromised population remains at the threat of end-stage liver diseases, mostly in areas where vaccine schedules are inaccessible. Nucleotide/nucleoside analogs like lamivudine, adefovir, tenofovir, telbivudine, entecavir, and the immune modulator pegylated interferon-α (Peg-IFN-α) were used for the treatment of HBV infections (Kwon & Lok, ). Nevertheless, it is difficult to eradicate HBV from the body once a prolonged inflammation occurs. The condition gets exacerbated by threats of selecting drug-resistant viral mutants, failure of diagnosis in non-responders, and possible future viral recurrence. Thus, anti-HBV drugs' development will always be of significance for the scientific attention and hepatitis B management system's assistance to diagnose about 300-400 million carriers globally (Franco et al., ).

Phyllanthus species are considered an essential source of antiviral bioactive metabolites such as lignans, including hypophyllanthine and phyllanthine, flavonoids (ternatin), and alkaloids such as quercetin. They can block the endogenous DNA polymerase enzyme of HBV, which is crucial for viral replication (Venkateswaran et al., ). A variety of bioactive metabolites extracted from Phyllanthus niruri were also evaluated for their inhibitory potential, using sera containing HBsAg, collected from chronic HBV patients (Thyagarajan et al., ). Subsequent studies have revealed the in vivo efficiency of P. niruri extract in eliminating HBV in 3-6 weeks in mammals. A 90-day treatment with plant extracts successfully reduced the HBV antigen to undetectable levels among two-thirds of HBV-positive patients (Wang et al., ). Further, numerous studies were conducted in the last several years to recognize anti-HBV molecules from medicinal herbs (Cui et al., ; Qiu et al., ; Zhan et al., ; Zhang et al., ). For examples, the antiviral effects of the saikosaponins from Bupleurum species and the ethanol extract from Polygonum cuspidatum were reported against HBV in vitro (; Chang et al., ; Chang et al., ). Further, curcumin showed to suppress the HBV gene's replication and an appearance by controlling the peroxysome proliferator-activated gamma receptor co-activator 1-alpha (PGC-1α), the HBV transcription co-activator (Rechtman et al., ). Furthermore, Phyllanthus, Salvia miltiorrhiza, Rheum palmatum L., and Radix astragali and chemical compounds like oxymatrine, artemisinin, artesunate, and wogonin also reported promising anti-HBV activities (Cui et al., ). Other examples include isochlorogenic acid A, amide alkaloid, and dehydrocheilanthifoline from Laggera alata, Piper longum, and Corydalis saxicola experienced high anti-HBV activities (Hao et al., ; Jiang et al., ; Zeng et al., ). The LPRP-Et-97,543, isolated from the roots of Liriope platyphylla, hinders the mechanism of HBV's action by regulating the gene expression and the DNA replication by viral proteins by interacting with the pathway of NF-αΚB nuclear factor (Huang et al., ).

There seems to be a lack of studies on bioactive components' mode of action against HBV, while most natural compounds were proven to effectively suppress the HBV (Wu, ) (Table 3). For instance, Acanthus ilicifolius L. significantly decreases HBV-induced liver damage by lowering the transaminase (Wei et al., ). Gymnema sylvestre phytoconstituents prevent HBsAg binding and HBV DNA polymerase activity (Subashini and Rajendran, ). Further, the expression of intracellular HBV DNA in HBV WT-or mutant-transfected HepG2 cells declined following Phyllanthus extract treatment. Phyllanthus triggered interferon-beta, cyclooxygenase-2, and interleukin-6 mRNA expression in HBV WT-transfected HepG2 cells, probably by modulation of extracellular signal-regulated kinases and c-jun N-terminal kinases and by induction of retinoic acid-inducible gene-I, toll-like receptor 3, myeloid distinctions of primary response gene, and tumor necrosis of fac (Jung et al., ). Two new major C-boivinopyranosyl flavones (luteolin-6-C-β-d-boivinopyranosyl-3′-O-β-d-glucopyranoside and chrysoeriol-6-C-β-boivinopyranosyl-4′-O-β-d-glucopyranoside) isolated from Alternanthera philoxeroids showed substantial anti-HBV activity by reducing HBsAg secretion in HepG2.15 cells (Li et al., ).

Natural products/Extracts evaluated

Virus strain assessed

Culture/Animal model assessed

Proposed mechanism

References

1,2,3,4,6-penta-O-galloyl-beta-d-glucoside ( Saxifraga melanocentra Engl.& Irmsch)

HCV

COS-7 fibroblast-like cells

Inhibition against HCV NS3 serine protease

Zuo et al., 2005

Epigallocatechin-3-gallate

HCV

Huh7 cells

Inhibits viral entry by affecting the fluidity of the HCV envelope; inhibits viral entry

Rhusflavanone ( Rhus succedanea and Garcinia multiflora) as well as their methyl ethers and acetates

MV

Vero cell lines

Undefined

Lin et al., 1996

Zanthoxylum chalybeum and Warburgia ugandensis

MV

Vero cell lines

Undefined

Olila et al., 2002

Olinia rochetiana and Warburgia ugandensis

MV

U937 cell lines

Neutralize virus particles

Parker et al., 1997

Ethanol extract of leaves ( Senna angustifolia), ethanol extract of leaves ( Tridax procumbers), and methanol extract of leaves ( Vernonia cinerea)

DENV-2

Vero cells

Undefined

Hederasaponin B ( Hedera helix)

EV 71

Vero cells

Inhibition of viral capsid protein synthesis

Phytol, aloe-emodin, byzantionoside B, a mixture of trans-martynoside and cis-martynoside, a mixture of trans-isomartynoside and cis-isomartynoside, luteolin-7- O- β-d-glucopyranoside, and apigenin-7- O-[ β-d-apiofuranosyl (1→6)- β-d-glucopyranoside (Lindernia crustacean)

EBV

Burkitt's lymphoma cell line (P3HR)

Undefined

Consequently, ethanol extract of Sanguisorba officinalis and its significant compounds (ziyuglycoside I and II) against HBV in HepG2.2.15 cells inhibit replication and antigen secretion of HBV. Hence, describing the plant's tendency as novel candidates for the treatment of HBV-related diseases (Jang et al., 2018). The anti-HBV effect of Abrus cantoniensis were explored both in vitro and in vivo studies. Treatment of A. cantoniensis strongly suppressed the development of HBV DNA, Hepatitis Be Antigen (HBeAg), and Hepatitis B surface antigen (HBsAg) in HepG2.2.15 cells and rAAV8-1.3HBV transfected mice, which provides a base for its possible clinical usage (Yao et al., ). Quercetin and myricetin-3-O-rhamnoside extracted from Guiera senegalensis leaves showed antiviral activity (HBsAg and HBeAg assay) in HepG2.2.2.15 HBV-reporter cells. Quercetin notably repressed HBsAg and HBeAg synthesis by approximately 60 and 62%, respectively, compared to myricetin-3-O-rhamnoside by 44 and 35%. Their probable anti-HBV mode of action was expected by the ability to bind with viral Pol/RT and core as well as host NTCP proteins (Parvez et al., 2020).

Furthermore, the HBV inhibition activities of polysaccharide from Radix isatidis were mediated by the stimulation of the IFN-α-dependent JAK/STAT signal pathway and the initiation of protein expression against HBV (Wang et al., ). Swertisin obtained from Iris tectorum displayed a significant inhibitory effect for HBV replication by inhibiting HBeAg and HBsAg and HBV DNA (Xu et al., 2020). Although novel anti-HBV inhibitors were developed, the combination of remedies with conventional nucleotide/nucleoside analogs or IFN-α-based hepatitis B therapy must also be assessed in future research.

4.3.2 Hepatitis C virus

HCV is a flavivirus with a positive-sense ssRNA, usually transmits through blood-to-blood interactions, intravenous injections, blood transfusion, and varying exposures to blood toxic substances. Due to the overly abstract nature of HCV, a precautionary vaccine has not been available yet. Approximately 70% of infections are consistent, affecting an estimated 300 million carriers worldwide, among which 1-3% can proceed to end-stage liver diseases, such as cirrhosis and HCC (El-Serag, ). The recommended treatment comprises Peg-IFN-α plus oral ribavirin parenteral. Nevertheless, few challenges exist in the current method of HCV treatment. They have limited efficacy for specific viral genetic variants, unavoidable selection of drug-resistant mutants, adverse side effects, exorbitant prices of medication, patient adherence issues, and challenges in diagnosing communities such as non-responsive patients and patients with liver transplantation (Welsch et al., ). The rapid expansion of anti-HCV substances is indeed essential to address such deficiencies.

Table 3 summarizes the antiviral potential of different natural products determined against HCV infection. For instance, Silybum marianum and its flavonolignans showed significant anti-HCV activity in vitro (Polyak et al., , ). Many clinical trials showed a viable impact on reducing the viral load (Marino et al., ; Neumann et al., ). Curcumin was reported as a critical inhibitor of HCV replication by conceivably restricting the sterol regulatory element-binding to protein-1 (SREBP-1)-Akt pathway Kim et al., ), and its adverse impact on HCV entry (Anggakusuma et al., ). Many natural products deter HCV entry, including epigallocatechin-3-gallate, griffithsin, ladanein, and tellimagrandin I (Calland et al., ; Ciesek et al., ; Haid et al., ; Meuleman et al., ; Takebe et al., ). Similarly, chebulagic acid and punicalagin hydrolyzable tannins were found as competitive HCV intake inhibitors (Lin et al., ). Both tannins inactivate free virus particles, inhibit viral adhesion and penetration of the host cell, and interrupt HCV cell-to-cell post-infection transfer. As the HCV immunization is unavailable, the identification of new anti-HCV entry inhibitors could help develop preventive hepatitis C therapy/medication.

Loliolide isolated from Phyllanthus urinaria inactivates the HCV virus and stops viral attachment and entry/fusion (Chung et al., ). Leaves extract and fractions of Ficus fistulosa using Huh7it cells and HCV JFH1a inhibited HCV JFH1a with an IC ₅₀ value of 20.43 ± 4.51 μg/ml (Hafid et al., ). The dichloromethane extract of Artocarpus heterophyllus demonstrated good anti-HCV activity using Huh7it-1 cells with an inhibitory concentration (IC ₅₀) of (1.5 ± 0.6) μg/ml. A. Heterophyllus impeded the viral entry process by direct virucidal activity and targeting host cells and HCV RNA replication. HCV protein expression was substantially decreased by elevated-concentration treatment (Hafid et al., ). Antiviral activity of methanol extract of Ajuga bracteosa, Ajuga parviflora, Berberis lyceum, and Citrus lemon against HCV infected HepG2 cells showed that 24-hour treatment with A. parvifloras exhibited maximum antiviral activity, accompanied by A. bracteosa. The findings demonstrate these as a substitute standard therapy or in combination with conventional HCV therapies to treat HCV infections (Yousaf et al., ). Two fractions "N1" and "N8" isolated from acetone extract of Nymphaea alba suppressed HCV NS3 gene expression in transfected Huh-7 cells with an EC ₅₀ value of 37 ± 0.03 and 20 ± 0.02 μg/ml, respectively. Besides, the combination of fractions with the standard antiviral drug showed stimulatory activity to suppress HCV replication. N. alba and its isolated compounds may offer a promising source regimen against HCV, alone or even in mixture with other prospective anti-HCV entities (Rehamn et al., ).

4.4 HIV/AIDS and medicinal plants

A comprehensive list of herbal ingredients for HIV infection was examined (Cos et al., ; Singh & Bodiwala, ) (Table 3). In contrast, marine products with anti-HIV activity were reported as potential anti-HIV treatment (Kim et al., 2011; X. Zhou et al., ). Phytolacca americana is a potent source of a set of plant proteins known as pokeweed antiviral protein (PAP). Three isoforms, specifically from spring leave PAP-I, early summer leaves PAP-II, and late summer leaves PAP-III was identified as a class of ribosome-inactivating proteins (RIPs) responsible for causing depurination of genomic HIV-1 RNA (Rajamohan et al., ). Similarly, Momordica charantia and Gelonium multiflorum are considered useful sources of an anti-HIV protein MAP30 and GAP31, similar to RIPs known for their anti-HIV potency (Schreiber et al., ).

Furthermore, the leaves of P. americana also contain an anti-HIV protein PAP29, having a prophylactic anti-HIV potential. P. Wang and Tumer () reported that PAP isolation cleaves supercoiled DNA into linear and straightforward forms using the same active site required to remove rRNA purine. The RIPs are toxic N-glycosidases that purify the typically preserved α-sarcin loop of large rRNAs. Thus, depuration disables the ribosome, consequently obstructing its further involvement in protein synthesis. Several studies have shown that RIP's enzymatic activity is not only restricted to site-specific activity on ribosome rRNAs but also entails the depuration and nucleic acid scission of other targets (Barbieri et al., ; Horrix et al., ; Nicolas et al., ). Trichobitacin, a RIP, extracted from the roots of Trichosanthes kirilowiiis was reported to decline the appearance of the p24 HIV-1 antigen by reducing the number of antigens in HIV-positive cells in an acute in vitro assay but failed in cases of chronic infection (Zheng et al., ). Cyanovirin-N extracted from marine algae showed an inhibitory effect on HIV through aborting transmission and cell to cell fusion of HIV by interacting strongly with gp120 (De Clercq, ). Several sulfated polysaccharide groups extracted from seaweeds possess anti-HIV effects by interfering with viral adsorption (Duarte et al., ; Schaeffer & Krylov, ). Alkaloid extracts of P. niruri exhibited an inhibitory effect on HIV by monitoring the inhibition of HIV-induced cytopathogenecity in human MT-4 cells (Naik & Juvekar, ). Furthermore, coumarin-containing calophyllum species exhibited an inhibitory effect on HIV (Cesar et al., ; Huerta-Reyes et al., ). Similarly, the crude extracts of A. annua and Artemisia afra revealed promising anti-HIV efficacy (Lubbe et al., ). In regards, tricyclic coumarin reported from Calophyllum brasiliense stem bark suppressed HIV replication by repressing the activation of nuclear factor-kappa B (NF-κB) in in vitro models (Kudo et al., ).

The root extract of Pelargonium sidoides displays potent anti-HIV-1 activity by protecting peripheral blood mononuclear cells and macrophages from infection with several X4 and R5 tropic HIV-1 strains. Thus, it is considered a novel herbal medicine for anti-HIV-1 therapy with different action mechanisms and complementary to current single-molecule drugs (Helfer et al., ). Furthermore, Cistus incanus inhibited clinical HIV-1 and HIV-2 isolates in vitro, and no resistant viruses appeared throughout 24 weeks of continuous propagation of the virus in the presence of C. incanus aqueous extract (Rebensburg et al., ). Methanol extracts of Euphorbia spinidens Bornm (Euphorbiaceae) possess significant antioxidant activity due to high phenolics terpenes and saponins and flavonoid compounds and have a strong antiviral effect on HSV-1 by inhibiting the replication of the virus (Karimi et al., ; Mohammadi et al., ). Patentiflorin A isolated from Justicia gendarussa, shows significant activity against various HIV strains by acting as a potential HIV-1 reverse transcription inhibitor with IC ₅₀ values ranging from 15-21 nM (Zhang et al., 2017a, 2017b).

Besides this, a diverse range of medicinal plants such as Withania somnifera (Williams-Orlando, ), Tinospora cordifolia (Husain et al., ), Moringa oleifera (Monera-Penduka et al., ), Hypericum perforatum (Béjaoui et al., ), Silybum marianum (Lovelace et al., ), Panax ginseng (Cho & Kim, ), Hypoxis hemerocallidea (Jegede et al., ), Sutherlandia frutescens (Wilson et al., ), Lobostemon trigonus (Koffuor et al., ), and Curcuma longa (Kim et al., 2014b) were used in the diagnosis and treatment of AIDS. In comparison, four new lignans from the aerial parts of Justicia procumbens were examined for anti-HIV-1 activity. One of the new secoisolariciresinol dimethyl ether acetate showed significant anti-HIV-1 activity with an IC ₅₀ of 5.27 μM in vitro (Xu et al., 2019). Premised on the scientific advances till now, rapid advances in identifying natural antivirals against HIV must produce novel therapeutic regimens that would play a critical role in combating the existing immediacy of anti-HIV/AIDS therapeutics.

4.5 Anti-influenza virus and medicinal plants

Influenza A, B, and C viruses (IFA, IFB, and IFC) are encapsulated negative-sense ssRNA viruses categorized in the Orthomyxoviridae family. Such viruses can cause respiratory infection with symptoms include fever, headache, sore throat, sneezing, and muscle and joint pain, which can lead to devastating and potentially lethal situations like pneumonia (Eccles, ; Rello & Pop-Vicas, ). IFA (most epidemics) has a broad array of hosts, such as birds, human beings, and other mammals. At the same time, IFB seems to harm people naturally, and IFCs could be separated from humans and pigs (Pleschka, ). The infection of influenza viruses has caused significant human morbidity, and approximately 250,000 to 500,000 fatalities happen yearly as a consequence of periodic epidemics. This figure was documented to rise to about 20-40 million deaths in major pandemics, as was the case with the Spanish flu of 1918 (Saunders-Hastings & Krewski, ).

Hemagglutinin (HA) and neuraminidase (NA) protein envelopes are developed by the IF vaccines through prior contact or immunization, thus, making any pre-existing antibody inefficient and susceptible to infection. Another concern is the pervasive growth of drug resistance, mostly M2 ion channel blockers of amantadine and rimantadine, in the first wave of anti-influenza drugs. Resistant strains of available neuraminidase inhibitors such as oseltamivir and zanamivir (which mainly prevent the release of mature influenza viruses) have also been identified (Samson et al., ). As a result of drug resistance development, the rapid evolution of influenza viruses, and the incidence of many recent outbreaks (e.g., H5N1, H1N1, H7N9), more advanced antiviral strategies are urgently needed to prevent and control potential pandemics with evolving influenza strains (Shao et al., ). Numerous natural products have been assessed for their adverse effects on influenza (Table 3).

Pelargonium estides root extract restricts IFA entry influences, viral hemagglutination, neuraminidase function, and improves influenza-infected mice (Theisen & Muller, ). Aqueous extract from Taraxacum officinale inhibits IFA infection and reduces the activity of polymerase and nucleoproteins (NP) RNA levels (He et al., ). Several plant secondary metabolites were also determined as possible inhibitors of NA influenza (Grienke et al., ) such as chalcones from Glycyrrhiza inflata (Dao et al., ), xanthones from Polygala karensium (Dao et al., ), homoisoflavonoids from Caesalpinia sappan (Jeong et al., ), and spirooliganone B from the roots of Illicium oligandrum (Ma et al., ). Lariciresinol-4-O-d-glucopyranoside isolated from the root of Isatis indigotica hindered the IAV-induced pro-inflammatory response. The underpinning coping mechanism against IAV infection derives from pharmacological actions on the immune system, signal transduction, cell cycle, and metabolism (Li et al., 2015; Zhou et al., ). The Sambucus nigras activities against influenza were investigated extensively, especially in the vicinity (Roschek et al., ; Ulbricht et al., ). Studies have shown the potency of S. nigra toward infectious disease, which may be caused by immune system stimulation ( Ho et al., ; Ho et al., ). Immunomodulating peptic polysaccharides, polyphenolic, and flavonoid of S. nigra are responsible for suppressing the viruses. This plant's berries and flowers are documented from diverse cultures (Porter & Bode, ).

The double-blind trial was conducted among 40 adults and children in southern Israel confirmed to have influenza B. The fruit of Sambucus nigra (black elder) syrup or placebo 1 tbsp b.i.d. (for children) or 2 tbsp b.i.d. (for adults) was given. Symptom severity and duration (mean 1.3 days shorter with black elders) were appreciably lesser in the black elder group than placebo (Zakay-Rones et al., ). A similar double-blind trial of 60 adult Norwegians with influenza A or B was conducted. Again, symptom severity was significantly less with black elders than placebo, and in this case, recovery was on average 4 days quicker with black elders. The use of rescue medication was also notably less in the black elder group versus placebo. There were no adverse effects in either of these trials (Zakay-Rones et al., ). Recently, a randomized trial of 312 Australian adults undertaking international travel by coach received black elder capsules 300 mg b.i.d. before travel and t.i.d. during travel and after arrival, or placebo. Each participant took their assigned medicine for a total of 14 days. There was no difference between the groups in terms of the incidence of clinical viral respiratory infections. However, these colds' duration was significantly shorter and severity substantially less in the black elder group than the placebo. There was no difference between the two groups' adverse effects, suggesting no significant danger from black elders (Tiralongo et al., 2020). The development of these natural anti-influenza agents for clinical use will further extend the portfolio of drugs for prophylactic treatment of severe flu epidemics or pandemic.

4.6 Enterovirus 71 and medicinal plants

Preventive EV71 vaccines were currently developed, and palliative care is being used to improve the symptoms. However, many other natural products and herbal medicines exhibited inhibitory activity against EV71 infection (Table 3). The analysis revealed that O. basilicum extracts and isolated compounds effectively prevent EV71 disease and replication (Chiang et al., ). In contrast, raoulic acid recognized as a CVB inhibitor suppresses EV71 (Choi et al., ). Similarly, epigallocatechin gallate from green tea tamper with EV71 replication by modulating the redox cell environment (H. Y. Ho et al., ). Gallic acid from Woodfordia fruticosa flowers showed anti-EV71 activity (Choi et al., ). Anti-EV71 activity of chrysosplenetin and penduletin, two o-methylated flavonols confined from the leaves of Laggera pterodonta, showed vigorous anti-EV71 activity with low cytotoxicity. Throughout the time-of-addition assay, all compounds impeded progeny virus development and RNA replication by almost 100% when incorporated within 4 hr post-infection (Zhu et al., ). In relation, there were studies undertaken to study the antiviral capabilities of various plant or algae-derived EV 71-containing compounds (Chiu et al., ; Lin et al., ; Wang et al., 2011a; Wang et al., 2012d; Wang et al., ; Yang et al., ).

Contrary, phytochemicals evaluated for EV71 antiviral activity showed low cytotoxicity. Some of them, such as aloe-emodin, (Lin et al., ) extract of H. cordata, kappa carrageenan (Chiu et al., ) extract of Kalanchoe gracilis, and extract of Paris polyphylla Smith (Wang et al., 2011b) have a precise molecular mechanism(s) of action. The research tries to evaluate 12 frequently used antiviral herbs preferred by Chinese government agencies for the HFMD. H. cordata found the only remedy with potent antiviral activity against both EV71. These study results may justify follow-up experiments to determine the precise molecular mechanisms of action and to analyze the plant's anti-EV71 capability in the animal study (Chen et al., ). Chebulagic acid, isolated from Terminalia chebula fruit, displayed antiviral activity against human enterovirus 71 in vitro and in vivo models. Its treatment significantly reduced the viral cytopathic effect on rhabdomyosarcoma cells with an IC ₅₀ of 12.5 μg/ml. The use of chebulagic acid therapy in patients with enterovirus 71 effectively reduced mortality and alleviated clinical symptoms by inhibiting viral replication. Chebulagic acid may be a potent pharmacological entity to influence enterovirus 71 infections (Yang et al., 2013). Hederasaponin B and 30% ethanol extract of Hedera helix against EV71 subgenotypes C3 and C4a in Vero cells showed vigorous antiviral activity by lowering visible development CPE. It further impeded viral VP2 protein expression, implying the suppression of viral capsid protein synthesis (Hong et al., ; Song et al., ). Without appropriate medical care to prevent and treat EV71 infection, further studies are needed to explore novel enteroviral antivirals.

4.7 Respiratory syncytial virus and medicinal plants

RSV is an enshrouded negative-stranded ssRNA virus belonging to the Paramyxoviridae family. RSV is a prevalent virus responsible for respiratory illness in infants and toddlers (Hall, ). Almost all children often get afflicted with RSV well before 2 years (Braciale, ). It develops mild symptoms and bronchiolitis or pneumonia in infants and immunocompromised patients (Sigurs et al., ). Even though RSV causes the most severe illness in premature children, it continues to haunt living beings throughout their lifespan. Immune response to RSV is usually not sufficient to provide protection, but instead, humans are susceptible to reiterated re-infections (Hall et al., 2009; Henderson et al., ), that may be life-threatening for older or immune-compromised patients (Falsey & Walsh, ). Presently, RSV immunotherapy is not applicable. The therapies available for diagnosing RSV infections like palivizumab (a monoclonal antibody against RSV fusion protein) and ribavirin (nucleoside analog) are slightly effective. Therefore, it is necessary to develop new antivirals to manage RSV infections, and numerous plant-derived natural products were shown to display anti-RSV activity (Table 3).

Uncinoside A and B, the two isolated chromone glycosides from Selaginella uncinata, effectively inhibit RSV inflammation, and biflavonoids, namely genkwanol B, genkwanol C, and stellenranol derived from Radix Wikstroemiae, are said to have antiviral activity against RSV (Huang et al., ; Ma et al., ). Further, flavonous 6-C-monoglycosides from Lophatherum gracile leaves reported curtailing RSV infection in the cytopathic impact reduction assay (Wang et al., 2012c). Numerous natural anti-RSV therapies such as the herbal prescription ( Cimicifuga foetida L., and bioactive compound cimicifuga) relieve respiratory diseases (Wang et al., 2011; Wang, Ho, et al., ; Wang, Chen, et al., ). Furthermore, chebulagic acid and punicalagin hydrolyzable tannins possess antiviral activity toward RSV infection. The two tannins can explicitly inactivate RSV entities and obstruct viral entry aspects, like binding and fusion. They are inadequate against the transmission of RSV post-infection and could contravene the same event in MV, which is another paramyxovirus (Lin et al., ). Certain herbal products will help improve the respiratory tract symptoms induced by RSV, like inflammation of the respiratory system to target the viral infection. Resveratrol is one specific illustration documented to stabilize IFN-γlevels and prevent the trachea's inflammation/hyperresponsiveness throughout RSV infection in mice, implying its suitability to minimize airway symptoms triggered by RSV (Zang et al., ). Tangeretin and nobiletin (polymethoxylated flavones) obtained from Citrus reticulate (Pericarps) impaired RSV replication intracellularly. Tangeretin significantly suppressed RSV phosphoprotein (P protein) expression through virus-cell fusion inhibition at an early stage and cell fusion inhibition at the end of the replication process (Xu et al., ). Schefflera heptaphylla-derived dicaffeoylquinic acids also hindered RSV replication (Li et al., 2005b). The ethanol extract of Lophatherum gracile suppressed RSV infection and inflammation prompted in a dose-dependent manner (Chen et al., ).

4.8 Rotavirus and medicinal plants

Rotavirus is the common cause of chronic gastroenteritis in infants and young children across the globe. It is a paramount public health concern in low-income countries and massive morbidity and mortality rates in advanced nations (Parashar et al., ). The genus of rotavirus consists of nine species (A to I), but the only rotavirus A tends to cause more than 90% of human rotavirus infections (Kirkwood, ). The rotavirus's genetic material consists of 11 dsRNA segments that code for six structural and six nonstructural proteins. Structural proteins form the rotavirus particle called VP1, VP2, VP3, VP4, VP6, and VP7 premised on their molecular weight. Besides, nonstructural proteins are only produced during cell infection and are called NSP1, NSP2, NSP3, NSP4, NSP5, and NSP. Rotavirus afflicts intestinal cells and causes gastroenteritis; even so, the disease is not restricted to the gastrointestinal tract, and systemic viral transmission has been extensively illustrated (Ramig, ; Rivero-Calle et al., ).

While there is no particular antiviral drug for rotavirus, several other preventative actions like environmental hygiene and safe food and water can reduce the risk of rotavirus infection (Brown et al., ). The U.S. Food and Drug Administration (FDA) certified two subsequent oral attenuated vaccines as an efficient way to prevent rotavirus pandemics. The RotaTeq (Merck), a pentavalent human-bovine vaccine is comprising four rotavirus strains generated by recombination and Rotarix (GlaxoSmithKline), a monovalent human rotavirus vaccine that included one G1P-specific rotavirus strain (Desai et al., ; Gurgel et al., 2011). Hence, alternative safe therapies for rotavirus infections have become the subject of ongoing research (Alfajaro et al., ). Pinus koraiensis, Lomatium dissectum, Artocarpus integrifolia, Myristica fragrans, Spongias lutea, Tylosema esculentum, Byrsonima verbascifolia, Myracrodruon urundeuva Allemão, Eugenia dysenterica, Hymenaea courbaril, and Achillea kellalensis were reported to hinders rotaviral strains (Cecílio et al. ; Chingwaru et al. ; Gandhi et al., ; Goncalves et al., ; Taherkhani et al., ) (Table 4). The active ingredients have not yet been isolated and characterized from the above-described plant species. Further, chemical investigations are needed to explore plant species' chemical compounds in mass quantities and display more inhibitory effects toward rotavirus than that of the extract.

Plant name/Active compounds

Virus strain assessed

Test dose

Culture/Animal model assessed

Proposed mechanism

References

Epigallocatechin gallate and theaflavin digallate (green tea)

Human rotavirus (Wa)

IC ₅₀ 125 μg/ml to 250 μg/ml

MA-104 cells

Interfered with virus adsorption

Mukoyama et al., 1991b

Lomatium dissectum Nutt.

Bovine rotavirus)

Dilutions ranging from 1 × 10-l through 1 × l0 −7 of 0.2 ml of extract

MA-104 cells

Inhibited virus induced CPE

McCutcheon et al., 1995

Hesperidin and neohesperidin ( Citrus aurantium Linn.)

Human rotavirus (Wa)

IC ₅₀ 0.05 mg/ml, 10 μM/ml and 25 μM/ml

MA-104 cells

Hesperidin and neohesperidin exhibited inhibitory effect on rotavirus infection

Kim et al., 2000

Stevian ( Stevia rebaudiana)

Human rotavirus strains and SA-11

EC ₅₀ 431-492 μg/ml

MA-104 cells

Inhibitory activity against the replication of four serotypes of human rotavirus (HRV) and inhibited the binding of VP7 to the infected cells

Takahashi et al., 2001

Stevia rebaudiana Bertoni.

Human rotavirus and SA-11

EC ₅₀ 32-153 μg/ml

MA-104 cells

Inhibitory activity against the virus replication and binding of viral proteins VP7 not VP4 to the infected cells

Takahashi et al., 2001

Artocarpus integrifolia Linn. Myristica fragrans Houtt. and Spongias lutea Linn.

SA-11 and Human (HCR3) rotaviruses in MA-104 cells

(480 μg/ml), (160 μg/ml) and (40 μg/ml)

MA-104 cells

Antiviral activity against both the viruses

280 natural compounds

Rotaviruses

IC ₅₀ 7.5 μg/ml

MA-104 cells

18-β-glycyrrhetinic acid, abietic acid, alltrans-retinoic acid, and mangostin reduced the virus replication as well induced the cell signaling pathways involved in antiviral and inflammatory gene expressions

Shaneyfelt et al., 2006

Pectic polysaccharides (Panax ginseng C.A. Mey)

IC ₅₀ (15 and 10) μg/m

Human rotavirus (Wa)

MA-104 cells

Protecting cell viability from rotavirus-induced infection. It possibly allievated virus proliferation in cells

Polyphenols ( Glycyrrhiza uralensis Fisch)

EC ₅₀ of polyphenols were 18.7-69.5 μM against G5P[7] and 14.7-88.1 μM against G8P[7]

Bovine rotavirus G8P[7] and porcine rotavirus G5P[7]

Fetal rhesus Monkey kidney (TF-104) cells

Licocoumarone, licoflavonol, glyasperin D and 2′-methoxyisoliquiritigenin showed inhibition viral absorption, viral replication, and viral RNA synthesis

Kwon et al., 2010

Nelumbo nucifera Gaertn. Aspalathus linearis, Urtica dioica Linn.Glycyrrhiza glabra Linn. and Olea europaea Linn.

SA-11 and the Rhesus rotavirus Strain

IC ₅₀  < 300 μg/ml

MA-104 cells

Exerted antiviral activities and has no positive effect on the maintenance of trans-epithelial resistance

Alpinia katsumadai
Bovine G8P(7) and porcine G5P(7]) rotaviruses

EC ₅₀ 0.7 ± 0.4 to 33.7 ± 6.5 μg/ml against G5P(7) strainEC ₅₀ 8.4 ± 2.2μg/ml, 6.5 ± 0.8μg/ml, and 8.4 ± 5.0 μg/ml against G8P(7) strain

MA-104 cells

Blocked viral adsorption

Kim et al., 2012

Achillea kellalensis Boiss.

Bovine rotavirus

EC ₅₀ 100 μg/ml

MA-104 cells

Prevented viral replication and inhibited the viral CPE

Rice bran ( Oryza sativa Linn.)

Human rotavirus(VirHRV)Wa strain(G1P1A[8])

10% of the pigs total daily calorie

Neonatal gnotobotic pigs

Rice bran promoted thedevelopment of IFN-T cell responses, total IgM IgSCs in ileum and spleen, total IgA IgSCs in spleen and blood, and total serum IgM, IgA, and IgG

antibody production

Yang et al., 2014

Achillea fragrantissima Linn. Nitraria retusa (Forssk.) Asch

Human rotavirus (Wa) strain

IC ₅₀ 1.0-1.2 mg/ml and IC ₅₀ 0.9-1.4 mg/ml

MA-104 cells

Reduced viral titres against rotavirus

α-Glucosyl hesperitin and epigallocatechin gallate

SA-11

100 × 10 ³  μg/ml nd 80, 160, and 320 μg/ml

MA-104 cells

Loss of viral capsid protein

Genistein

Human rotavirus (Wa) and SA-11 strain

>160 μM

MA-104 human epithelial colorectal (Caco2) cells

Genistein inhibited rotavirus replication by upregulating AQP4 expression via the cAMP/PKA/CREB signaling pathway

Resveratrol, Piceatannol, Trans-arachidin-1 and Transarachidin-3

SA-11

10-20 μM

Human adenocarcinoma intestinal cell lines (HT29 FT8) and MA-104 cells

Two stilbenoids, trans-arachidin-1 and transarachidin-3 showed therapeutic potential against rotavirus replication via downregulating NSP4 protein levels

Aegle marmelos, Quillaja saponaria, Psidium guajava, Nelumbo nucifera, Aspalathus linearis, Urtica dioica, G. glabra, Olea europaea, Achyrocline bogotensis, Eucalyptus camaldulensis, Achillea fragrantissima, Nitraria retusa; Rindera lanata, and Euphorbia hirta were reported as novel antiviral candidates toward rotavirus infection. They interfere with virus absorption, inhibits virus replication, and reduces the levels of virus titers (Birdi et al., ; Brijesh et al., ; Civra et al., ; El-Baz et al., ; Knipping et al., ; Mohamed et al., ; Pilau et al., ; Roner et al., ; Téllez, Téllez, Vélez, & Ulloa, ). Besides, Vaccinium macrocarpon, Vitis labrusca, and Myracrodruon urundeuva (Cecílio et al., ; Lipson et al. , , ) decreases the level of external viral capsid proteins and influences the virulence of rotavirus. Similarly, bioactive compounds such as licocoumarone, licoflavonol, glyasperin D and 2′-methoxyisoliquiritigenin, carvacrol, 18β-glycyrrhetinic acid, luteolin, vitexin, apigenin-7-O-glucoside, and tannins from Diospyros kaki (Ebenaceae) inhibits the rotavirus infection of MA-104. Similarly, epigallocatechin gallate, theaflavin digallate, genistein, hesperidin, neohesperidin, diosmin, pectic polysaccharides isolated from the Panax ginseng; abietic acid, all-trans-retinoic acid, mangostin, α-glucosyl hesperidin, proanthocyanidins from Vaccinium macrocarpon and V. labrusca; resveratrol, piceatannol, trans-arachidin-1 and trans-arachidin-3, from Arachis hypogaea inhibited infections of fetal rhesus monkey kidney (TF-104), human epithelial colorectal (Caco-2), and human adenocarcinoma intestinal (HT29.F8) rotaviruses cultured cells (Baek et al., ; Ball et al., ; Gandhi et al., ; Hardy et al., ; H. Huang et al., ; Lipson et al., ; Pilau et al., ; Savi et al., ).

4.9 CV and medicinal plants

Unfortunately, hardly any vaccine or effective antibiotic treatments are presently available to avoid CV infections. However, natural ingredients, herbs, and traditional decoctions showed CV-infection therapy (Table 3). A study performed on 76 patients treated with Sophora spp. extract reported that RNA clearance of Coxsacki B virus was dose-dependent, and all patients displayed relief from arrhythmia, improved cardiac output, stroke volume, and cardiac index showed progress. The left ventricular mass and its index diminished expressively. The anti-Coxsackie antibody returns to the average titer after 5-months of treatment (Li, ).

Aqueous, ethanol extract and bioactive compounds, such as linalool, apigenin, and ursolic acid from Ocimum basilicum (sweet basil) reported antiviral activity against CVB1. In particular, Ursolic acid interacts with post-infection replication of CVB1 (Chiang et al., ). Further, Bupleurum kaoi was known to inhibit CVB1 infection by activating type I interferon response (Cheng et al., 2006b; Cheng et al., ). Raoulic acid from Raoulia australis was determined as an antiviral informant against many CVB subtypes; however, the mechanism for its influence is uncertain (Choi et al., ). Rheum palmatum (Polygonaceae) against CV B3 in vitro and in vivo showed inhibitory effects on HEp-2 cells. Extract-treated mice showed improved survival rate, reduced clinical symptoms, and lowered viral titers. The whole study demonstrates that interferon inducers of type I could be useful in maintaining CVB infection and could be further analyzed as a therapeutic intervention (Xiong et al., ). Besides, extracts of Dodonaea viscosa leaves displayed a therapeutic efficacy ranging from 0.3 to 25 with a reduction in virus titer ranging from 0.25 to 5 log10 TCID 50/0.1 ml against coxackievirus B3 (CVB3) infections. Crude extract provided significant inhibition of CVB3 replication by attaching to the viral capsid of CVB3, and prevents the virus from accessing host cells (Shaheen et al., ). Cornus officinalis, Acer triflorum, Pulsatilla koreana, and Clematis heracleifolia var. Davidiana Hemsl extracts showed significant antiviral activity toward CVA16 (Song et al., ). Isatindolignanoside A, a glucosidic indole-lignan isolated from aqueous root extract of Isatis indigotica revealed antiviral activity against CVB3 CVB3, with IC ₅₀ and SI values of 25.9 μM and >3.9, respectively (Meng et al., 2018).

4.10 Dengue virus and medicinal plants

DENV is an encased positive sensory ssRNA virus of the Flaviviridae family. The DENV is transferred particularly by mosquito bites of Aedes aegypti and is an influential arbovirus in Southeast Asia (Black et al., ). However, most of the four virus serotypes (DENV 1-4), could trigger dengue fever (Back & Lundkvist, ). Clinical symptoms of DENV infection include evident/mild febrile exposure, contemporary dengue fever (fever, headache, myalgia, joint pain, nausea, vomiting, and skin rash), and life-threatening hemorrhage diseases, explicitly dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) (Sam et al., ). Although this is an obsolete viral infection, current vaccination and treatment interventions accessible to prevent and control DENV infection are minimal. The management of dengue-related illnesses entails mosquito-controlled viral infection prevention and the alleviation of infected patients' symptoms.

Developing preventative/pharmacological intervention for DENV infection with natural ingredients could resolve these practical limits. Quite a few natural compounds, like quercetin and narasin, and marine algae derivatives exhibit robust anti-DENV features (Zandi et al., ; Low et al., ; Koishi et al., ) (Table 3). For example, Flavone baicalein shows inhibitory activities against DENV adsorption to host and post-entry viral replication (Zandi et al., ). Also, chebulagic acid and punicalagin, extracted from Terminalia chebula, have a broad array of antiviral agents against the viruses (Lin et al., ). They will effectively inactivate free DENV particles and tamper with attachment and fusion incidents throughout the early viral entry. Nordihydroguaiaretic acid extracted from the leaves of Larrea tridentata (Zygophyllaceae) was found to hinder the replication of the linked DENV by approaching genome replication and viral assembly (Soto et al., 2014).

In contrast, flavonoids are the inhibitors of NS2B-NS3 serotype 2 and 3 DENV proteases with IC ₅₀ values ranging from 15 to 44 μM. Myricetin is non-competitive serotype 2 NS2B-NS3 protease inhibitor with Ki values of 11 and 4.7 μM, respectively (Sousa et al., 2015). Ethanol extracts of Cassia grandis leaves, and Tabernaemontana cymosa bark toward two DENV serotype 2 strains DENV-2/NG and DENV-2/16681 in VERO, and U937 cells hinders viral replication and significantly impact viral internalization (Hernández-Castroa, Diaz-Castillo, & Martínez-Gutierrez, ). The recognition of such natural viral inhibitors may help in building anti-DENV therapy and lower DHF/DSS risk. Schisandrin A extracted from Schisandra chinensis hinders DENV replication by up-regulation of antiviral interferon responses through STAT signaling pathway (Yu et al., 2017).

4.11 MV and medicinal plants

MV is an encased negative-sense ssRNA virus of the Morbillivirus gene (Family: Paramyxoviridae). MV induces measles (an acute respiratory infection characterized by fever, conjunctivitis, coughing, runny nose, and nausea), and a generalized red macular rash across the body resulting in pneumonia encephalitis (Sabella, ). Although extremely infectious by interaction with respiratory secretions or airborne particulates, immunotherapies toward measles were described as a three-part MMR vaccine (measles, mumps, and rubella). Despite an effective MV vaccine, the virus remains a vital assassin for children in the developing world (Clements & Cutts, ; Murray & Lopez, ). A severe further aspect is a resurgence of measles in vaccinated populations and non-immunized individuals (Mossong & Muller, ; Zandotti et al., ). Such problems highlight MV's medical significance and the need to develop appropriate drug therapies.

Natural products from East and South-east Asian medicinal plants (Kurokawa et al., ), the herbal decoction (Huang et al., ), the Cherokee remedy spicebush (McWhorter, ), plant bioflavonoid isolated from Rhus succedanea and Garcinia multiflora (Lin et al., ), calcium spirulan from the blue-green alga Spirulina platensis (Hayashi et al., ) and several Rwandan and Ugandan medicinal plant extracts were reported to inhibit MV infection (Cos et al., ) (Table 3). In contrast, certain Olinia rochetiana (Olkirenyi) and Warburgia ugandensis (Osokonoi) typical dietary herbal additives were demonstrated to suppress in vitro MV infection (Parker et al., ). Another example is the Cajanus cajan extracts recommended to have anti-MV activity, though their bioactive components remain unknown (Nwodo et al., ). The chebulagic acid and punicalagin tannins showed potent efficacy against MV infection, mainly by inhibiting the virus particles, disrupting the attachment and fusion stages throughout viral entry (Lin et al., ). Therefore, they could serve as potential entry inhibitors to MV.

5 CONCLUSION AND FUTURE PERSPECTIVES

Antiviral drug production is a concern, as enzymes do not behave like normal living cells and antiviral medications could only deter replication of viruses or inhibit deeper inflammation. Accordingly, plant extracts/botanically derived compounds were documented with potential antiviral activity in cell line and animal model studies. Intriguingly, different mechanisms were established for these compounds, among which virucidal behavior is the most prevalent. Other confirmed exercises include hindering virus entrance into target cells, inhibiting viral protein expressions like 3CLpro, PLpro, S, and ACE2, and interfering with viral DNA replication, all of which are essential prerequisites constructing individual viral particles. Besides, the introduction of high-throughput technologies and traditional medicines together might play a critical role in assessing potential plant-derived substances for innovative discovery in contemporary drug development. They compete against viral diseases but have a long way to go before final use in the clinic to compensate for exploration, isolation, and mechanistic studies. Given the broad diversity of bioactive molecules derived from plants, a reliable, relentless, and constant approach is necessary to pursue unidentified bioactive molecules with potent antiviral activity, particularly relative to the risk posed by pathogenic viruses to enhance resistance to antibiotics. Many natural products like lycorine, homoharringtonine, silvestrol, ouabain, tylophorine glycyrrhetinic acid, acetoxime, and caffeic acid chebulagic acid, punicalagine and 7-methoxycryptopleurine possess significant antiviral activity even in the nanomolar concentration and will be better candidates for novel drug discovery. However, it requires further research to demonstrate the mechanism of secondary metabolites' action in an in vivo and invitr o model.

In contrast, many natural products with good antiviral activity are the essential components of some traditional food additives that could strengthen the wider public's immune system in inevitable outbreaks. Further, research must entertain therapeutic agents' feasibility with several other natural sources or with existing drugs, as the multi-target treatment mitigating the chances of drug-resistant viruses being developed. Therefore, comprehensive research in the forthcoming could recognize the possible antiviral molecules and understand their mechanism of action to stabilize such fatal viruses more appropriately.

CONFLICT OF INTEREST

The authors declare no conflicts of interest.

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Medicinal plants: Treasure for antiviral drug discovery

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Sofi Imtiyaz Ali , Wajid Mohammad Sheikh , Muzafar Ahmad Rather , Venugopalan Venkatesalu , Showkeen Muzamil Bashir , Showkat Ul Nabi , Corresponding Author Showkat Ul Nabi Large Animal Diagnostic Laboratory, Department of Clinical Veterinary Medicine, Ethics & Jurisprudence, Faculty of Veterinary Sciences and Animal Husbandry, SKUAST-K, Srinagar, India Correspondence Showkeen Muzamil Bashir, Biochemistry & Molecular Biology Lab, Division of Veterinary Biochemistry, F.V.Sc.

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#Farmacogenômica A expansão das evidências leva a uma nova cobertura do pagador de farmacogenômica

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#Farmacogenômica A expansão das evidências leva a uma nova cobertura do pagador de farmacogenômica

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Olá, pessoal! Hoje trago um artigo que achei muito interessante sobre o tema de farmacogenômica.

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In Dr. Francis Collins' 2001 testimony to Congress, he heralded advances in genetics with the Human Genome Project. He imagined testing "being used to tailor medicines to fit individual genetic profiles, since drugs that are effective in some people are less effective in others and, in some, cause severe side effects." It has been nearly 20 years and, finally, this promise of pharmacogenomics is becoming a reality through increasing clinical implementation and recent significant milestones in payer coverage.

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Affiliations

1. Department of Pharmacy and Therapeutics, University of Pittsburgh, Pittsburgh, PA, USA

Philip E. Empey

2. Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA

Victoria M. Pratt

3. Office of Quality & Patient Care, St. Jude Children's Research Hospital, Memphis, TN, USA

James M. Hoffman

4. Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA

James M. Hoffman & Kelly E. Caudle

5. Department of Biomedical Data Science and Medicine, Stanford University, Stanford, CA, USA

Teri E. Klein

Corresponding author

Correspondence to Philip E. Empey.

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Competing interests

P.E.E. is a Co-Investigator on Implementing Genomics in Practice (IGNITE) project grant (U01 HG010245) and has provided consultative services for Cipherome. V.M.P. reports the following: the Indiana University School of Medicine Pharmacogenomics Laboratory is a fee-for-service clinical laboratory that offers clinical pharmacogenetic testing. V.M.P. is supported by the IGNITE project grants (U01 HG007762 and HG010245) and is on the clinical advisory board of Avalon Healthcare Solutions. J.M.H. is a Co-Investigator for CPIC (NIH/NHGRI U24HG010135). K.E.C. is the Co-Principal Investigator for CPIC (NIH/NHGRI U24HG010135). T.E.K. is the Co-Principal Investigator for the PharmGKB (NIH/NHGRI/NICHD U24 HG010615), CPIC (NIH/NHGRI U24HG010135) and PharmCAT (NIH/NHGRI U24 HG010862). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

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Empey, P.E., Pratt, V.M., Hoffman, J.M. et al. Expanding evidence leads to new pharmacogenomics payer coverage. Genet Med 23, 830-832 (2021). https://doi.org/10.1038/s41436-021-01117-w
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DOI: https://doi.org/10.1038/s41436-021-01117-w

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Highlights

Recent advances in multipass membrane protein (MP) production and formulation strategies have made them more accessible as drug targets.

Growing knowledge of MP function modulators (ligands, specific lipids/cholesterol, nanobodies stabilizing desired conformations, or protein interaction partners) can aid selection of more specific MP-targeting drugs in discovery assays.

Increased sophistication in structure determination [e.g., cryoEM (cryogenic electron microscopy)] and high-throughput assay technologies, such as the ability to monitor protein-protein interactions and conformational changes, complement advances in MP production.

Challenges for targeting MPs with monoclonal antibody therapeutics are being addressed by judicious choice of immunization host, in vitro discovery platforms, and implementation of activity assays to select function-modulating antibodies.

Integral membrane proteins (MPs) are important drug targets across most fields of medicine, but historically have posed a major challenge for drug discovery due to difficulties in producing them in functional forms. We review the state of the art in drug discovery strategies using recombinant multipass MPs, and outline methods to successfully express, stabilize, and formulate them for small-molecule and monoclonal antibody therapeutics development. Advances in structure-based drug design and high-throughput screening are allowing access to previously intractable targets such as ion channels and transporters, propelling the field towards the development of highly specific therapies targeting desired conformations.

Keywords

G protein-coupled receptors

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COVID-19

COVID-19 background

The new pandemic coronavirus disease 2019 (COVID-19) is caused by the novel Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). COVID-19 is currently triggering enormous global demands on health systems and presents an unprecedented challenge to identify effective drugs for prevention and treatment [ 1]. Coronaviruses have a genome made of RNA. Viruses with RNA genomes have an essential gene called the RNA-dependent RNA polymerase (RdRp), which is highly conserved, meaning that there are few changes in the gene from one RNA virus to another [ 2]. SARS-CoV2 binds principally to the cell-membrane angiotensen converting enzyme 2 (ACE2) receptors through the viral structural spike (S) protein [ 3]. At the intracellular level, the virus activates cellular processes to produce viral proteins that replicate the virus's genetic material, providing potential targets for drug therapy [ 4].

COVID-19 therapy

In an urgent attempt to mitigate devastating catastrophe of SARS-CoV2, many drugs without established efficacy have been used in patients either as an offlabel/compassionate use or as a clinical trial [ 5, 6, 7, 8]. A combination of antivirals with different mechanisms of action may be more effective but at the same time, their adverse effects should not be underestimated [ 9, 10]. Mechanistic and in vitro analyses suggest multiple promising therapeutic options with potential for repurposing to treat patients with COVID-19 [ 11]. Drug repurposing is an attractive approach with reduced time and cost to treat COVID-19 [ 12, 13, 14]; however, limitations such as low success rate and the possibility of adverse side effects, can not be overlooked [ 13, 14, 15, 16, 17]. There is limited data on the human genome interactions with many of these agents and this may constitute an obstacle for successful COVID-19 therapy. Knowing the major human genetic variants association with the clinical therapeutic outcome has the potential not only to expedite emergency use authorization and approvals but also to afford an additional level of safety and efficacy to patients. Therefore, the purpose of this review is to look at some drugs commonly used in regimens for COVID-19 and provides specific examples of how genetics may affect drug efficacy and toxicity. It adds to the efforts of recently published relevant articles [ 18, 19, 20] and does not serve as an exhaustive review of all relationships between host genetics and these drugs.

Pharmacogenomics (PGx) overview

Genetic polymorphism

Genetic polymorphisms are a type of genetic diversity within a population's gene pool. Single nucleotide polymorphisms (SNPs), are the most common type of genetic variation among people. Various polymorphisms exist in genes encoding phase 1 cytochrome P450 (CYP) or phase 2 drug-metabolizing enzymes, transporters, drug targets, or human leucocyte antigen (HLA) alleles and predict drug efficacy or toxicity [ 21, 22]. Genetic variations of CYP2C9, CYP2D6, CYP2C19 and CYP3A5 were associated with therapeutic effects of phenytoin [ 23], tamoxifen [ 24], clopidogrel [ 25], and tacrolimus [ 26], respectively. The dose regimens of mercaptopurines and irinotecan should be adjusted according to the polymorphism of thiopurine methytransferase (TPMT) [ 27] and UDP glucuronosyltransferase 1A1 (UGT1A1) [ 28], respectively. A variant allele in the solute carrier organic anion transporter family member 1B1 (SLCO1B1) gene has been associated with statin-induced myalgia [ 29]. A common variant in the vitamin K epoxide reductase complex subunit 1(VKORC1) gene, has also been strongly associated with inter-individual warfarin dosing variability [ 29].

Pharmacogenetics and PGx

Evidence-based PGx resources

The rapid innovation in sequencing technology and genome-wide association studies has led to the development of numerous data resources and dramatically changed the landscape of PGx research. Resources provided by organizations such as The Clinical Pharmacogenetics Implementation Consortium (CPIC) [ 27] and The PGx Knowledgebase (PharmGKB) [ 33], that use standardized approaches to evaluate the literature and provide clinical guidance, are essential for the implementation of pharmacogenetics into routine clinical practice. Important online resources such as PharmGKB.org and cpicpgx.org provide the clinician with summarized PGx associations and clinical guidelines. Other resources include SCAN and PACdb PGx databases developed and published by the PGx of Anticancer Agents Research Group. SCAN is designed to collect, annotate, and present the relationship between genotype and gene expression. It is a large-scale genetic and genomic database containing SNP and copy number variation annotations along with a web interface, a set of methods and algorithms, and some data mining tools [ 34]. PACdb is a pharmacogenetics-cell line database collecting pharmacology-related information including genotypes, gene expression, and pharmacological data gathered via lymphoblastoid cell lines [ 35].

PGx clinical implications and testing

In recent years, clinical evidence has strengthened, guidelines have emerged, and genomic medicine is becoming integrated into routine care for certain disease states, such as some cancers. Recently, the FDA approved direct-to-consumer tests for PGx, breast cancer risk, and propensity to develop certain conditions (e.g., Parkinson's and Alzheimer's diseases) [ 36]. A notable example is that CYP2C9 and VKORC1 genotypes predict different sensitivity and resistance frequencies in the Ashkenazi and Sephardi Jewish populations necessitating warfarin dose adjustment [ 37]. Many major medical institutions have started implementing genotyping protocols for preemptive pharmacogenetic testing [ 38]. A good example of a pharmacogenetic test is the association between a particular HLA allele (HLA-B*5701) and hypersensitivity reactions to abacavir [ 39]. Moreover, HLA-B*1502 screening is successful in patients who are prescribed carbamazepine, particularly in Asians. The HLAB*1502 allele is associated with carbamazepine-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) [ 27].

Repurposed anti-COVID-19 drugs

Chloroquine (CQ)and hydroxychloroquine (HCQ)

SARS-CoV-2 uses ACE2 receptors expressed on host epithelial cells along with cofactor transmembrane protease, serine 2 (TMPRSS2) to enter the cell. HCQ and CQ inhibit virus entry by targeting the endosomal pathway. They increase the pH of endosomes and inhibit membrane fusion [ 43]. In addition, inhibition of SARS-CoV-2 could be partly due to differential glycosylation of both ACE2 and the spike protein [ 44]. Several variants in ACE2 including p.Met383Thr, p.Pro389His, and p.Asp427Tyr were identified in the African American and Latino American populations. These pathogenic variants in ACE2 may inhibit interaction with the S protein and could influence the clinical efficacy of HCQ or CQ [ 45]. The ACE2 receptor N720D variant may enhance TMPRSS2 activation and subsequent viral entry [ 46]. HCQ and CQ may only work for TMPRSS2-absence patients who are infected by SARSCoV-2, and may have less effect or no effect for the patients with wild-type TMPRSS2 [ 47].

In patients with COVID-19, CQ has been administered orally at a dose of 300 mg for adults, twice daily (bid) for a maximal duration of 10 days. HCQ therapy is started at a loading dose of 400 mg bid. on day 1 and then lowered to 200 mg bid (10 days average). A recent study showed that both drugs have favorable and unfavorable characteristics, but none showed clear evidence of benefit for early outpatient disease or prophylaxis [ 48].The most severe complications from use of HCQ and CQ include QTc prolongation and ventricular arrhythmias [ 49], which may pose a particular risk to critically ill patients. HCQ and CQ undergo N-dealkylation via CYP isozymes [ 50]. A few reports have described significance of gene polymorphisms in affecting HCQ or CQ treatment outcome. In African children with acute falciparum malaria, peak plasma CQ and DCQ concentrations were highly variable [ 51]. In malaria patients from Tanzania [ 52], India [ 53] and Sudan [ 54], the mean plasma CQ concentrations were higher in sensitive patients than in resistant patients. The carriers of CYP2C8-reduced activity alleles showed lower efficacy as compared with homozygous wild-type allele *1  A [ 55]. CYP2C8*4 is a missense mutation, which promotes a lower enzyme activity in vitro than the wild-type allele *1  A, and similarly CYP2C8*2 and CYP2C8*3 also present a markedly decreased activity in vitro [ 56]. Both CQ and HCQ are metabolized by hepatic cytochrome P450 CYP2D6, the expression of which varies among individuals as the result of genetic polymorphisms. High HCQ concentrations have been observed in individuals who are poor or intermediate CYP2D6 metabolizers (CYP2D6*4; CYP2D6*10) [ 57]. Both CQ and HCQ were reported to inhibit CYP2D6 activity [ 58]. They may potentiate other CYP2D6 substrates such as labetalol and carvedilol [ 59] and decrease the effectiveness of prodrugs reliant on CYP2D6 for activation such as codeine and tramadol [ 60]. There is no established clinical guidance related to CYP2D6 gene variants in CQ or HCQ use. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is most common in the Mediterranean area, in Europe, in Middle East, Asia and parts of Africa. Genetic variants affecting G6PD activity show remarkably individual and ethnical differences [ 61]. More than 160 G6PD genetic variants have been identified including G6PD B (wild type), G6PD A (non-deficient type) and G6PD A − (African deficient type). G6PD 376 G/202 A haplotype is the most common G6PD variants in sub-Saharan Africa [ 62]. CQ and HCQ use in individuals having genetic mutations in the G6PD may induce hemolysis and hemolytic anemia.

The blood group ABO gene encodes glycosyltransferases which determine addition of N-acetylgalactosamine or galactose to H antigen and subsequently determines A and B antigens. Vasku et al. [ 63] identified an association of blood pressure with ACE I/D polymorphism and ABO blood group. Genetic variation within Fucosyltransferase 2 (FUT2) has been studied extensively in the context of human exposure. Homozygotes for the nonsense mutation (rs601338 G > A) that inactivates the FUT2 enzyme are unable to secrete ABO(H) histo-blood group antigens or express them on mucosal surfaces [ 64]. An association between the A allele and COVID-19 prevalence/mortality was recently confirmed [ 65]. ABO blood group, Hb genotype and G6PD status showed no significant influence on CQ treatment outcome in Nigerian children with uncomplicated malarial infection, but there was greater risk of developing resistance to CQ in HbAA than HbAS individuals [ 66]. Another well-recognized adverse effect of HCQ and CQ is retinopathy, which occurs more frequently with long term use and higher doses. Retinopathy occurred less frequently in those with the minor allele of ATP-binding cassette (ABC) transporters ABCA4 c.5814 A > G [ 67]. CQ and HCQ should be used with caution especially in combination with other drugs or at high doses potentially with monitoring of RBC or hemoglobin levels and genetic testing should be recommended.

Azithromycin

This macrolide antibiotic is used extensively in patients with viral infections to prevent severe respiratory tract infections Azithromycin-HCQ combination shows a synergistic effect on Covid-19 disease [ 68]. The pharmacokinetics (PKs) of azithromycin are influenced by the activity of P-glycoprotein (P-gp) transporter encoded by ABCB1. Genetic variation in ABCB1 showed up to a twofold lower peak azithromycin concentrations in 20 healthy volunteers after a single dose [ 69]. Higher systemic exposure to azithromycin is of particular concern when it is combined with HCQ or CQ because of their additive effects on QTc prolongation.

Protease inhibitors

Lopinavir (LPV)/Ritonavir (RTV), LPV/r

LPV blocks a postentry step in the MERS‐CoV replication cycle, conferring this drug a promising potential agent for COVID-19 [ 70]. RTV blocks CYP3A-mediated metabolism of LPV thereby prolonging its exposure. LPV is metabolized primarily through CYP3A and transported by ABCB1 and ABCB2. RTV is metabolized by CYP2J2, CYP3A4, CYP3A5 and CYP2D6. RTV inhibits CYP3A and organic anion transporting polypeptides (OATP1B1 and OATP1B3), and may also induce other CYP isoforms [ 71]. RTV is enhancing the effect and concentrations of the medicines usually metabolized by CYP3A4, including LPV. RTV also increases the biotransformation of some drugs metabolized by glucuronidation catalyzed by UGT. The clinical relevance of these effects needs to be investigated. LPV/r was used in a regimen of 400 mg/100 mg bid for adults for 10-21 days [ 72]. There is also an initiative to reformulate LPV/r in a new extracellular vesicles delivery system [ 73].

Genetic screening of Apo lipoprotein E (APOE) and APOC3 can reduce the risk of hypertriglyceridemia and lipodystrophy associated with RTV [ 74]. Interindividual variations of LPV concentration were associated with SLCO1B1. A pharmacogenomic analysis of LPV/RTV, including 1380 variants in 638 HIV-infected Caucasians, identified four significant variants. Clearance of LPV was higher in individuals with SLCO1B1*4/*4 and lower in individuals with two or more variant alleles of SLCO1B1*5, ABCC2 or a CYP3A [ 75]. The CYP3A4 polymorphism L292P (rs28371759, CYP*18B) is linked with increased CYP3A4 activity, thus facilitating the metabolism of drugs like LPV. L292P was reported to occur more in East Asians, indicating that East Asians may metabolize LPV and RTV more rapidly. There are about 66 coding SNPs in ABCB1 gene [ 76]. The 3435 C > T is present in exon 26 of the ABCB1 gene, involving a C-to-T transformation, and does not alter the amino acid isoleucine. The variant allele frequency of 3435 C > T in the Asian population differs significantly from the African and Caucasian population [ 77]. There are many non-synonymous polymorphisms in ABCB1 [ 78]. Among them, S893T, S893A (rs2032582), N21D (rs9282564) and S400N (rs2229109) can increase the drug concentration through decreasing the efflux of ABCB1. S893A carriers are found in all populations with high frequency, which is up to 90% in Africans. S893T carriers are almost East Asians, while N21D carriers are Europeans. These patients may have more response to the drugs transported by ABCB1.

Atazanavir (ATV)

ATV exhibits potent anti-HIV activity and good oral bioavailability. ATV inhibits SARS‐CoV2 replication in both Vero cells and human epithelial pulmonary cells (A549). ATV is metabolized by CYP3A and is an inhibitor of CYP3A and UGT1A. The CPIC guideline for ATV considers several polymorphisms in UGT1A1, including a variable dinucleotide (TA) repeat within the gene promoter region (rs8175347, alleles UGT1A1*28, *36 and *37), and the SNPs rs4148323 ( UGT1A1*6) and rs887829 ( UGT1A1*80) [ 79]. The UGT1A1*28 allele predisposes to severe hyperbilirubinemia in individuals exposed to ATV [ 80]. UGT1A1*28 homozygotes have the highest risk and UGT1A1*28 heterozygotes have an intermediate risk of developing hyperbilirubinemia [ 81]. The CPIC guidelines for pharmacogenomic prescribing of ATV recommend counseling on the likelihood of developing hyperbilirubinemia in UGT1A1*28/*28,*28/*37, *37/*37, and −364 TT genotype carriers before initiating therapy [ 79]. ATV metabolism is partially due to the P-gp efflux pump encoded by the multidrug resistance 1 ( MDR1) gene, which seems to increase plasma concentrations of ATV in the presence of 3435 variable genetic homozygosis C/C, exposing the patient to a risk of hyperbilirubinemia and severe jaundice. Polymorphism 238 G > A appears to be related to an early onset of lipodystrophy [ 82]. Several studies demonstrated that APOA5 gene polymorphisms (1131 T > C and 64 G > C), APOC3 (482 C > T, 455 C > T, 3238 C > G), and ABCA1 (2962 A > G) and APOE (ε2 and ε3 haplotypes) are associated with a high risk of dyslipidemia [ 83].

Non-nucleoside reverse transcriptase inhibitors (NNRTIs)

Favipiravir (FVP)

Nevirapine (NVP)

NVP is a NNRTI widely prescribed for HIV treatment. It is generally effective with some reported cases of hepatotoxicity and severe cutaneous adverse reactions. The HLA-DRB1*01, HLA-B*3505 and CYP2B6 gene polymorphisms have been associated with the onset of rash from NVP [ 87]. The CYP2B6 983 C allele was reported to confer a higher risk of SJS and TEN in a population of Mozambique treated with NVP. Polymorphism C > T position 3435 of MDR1 was associated with reduced risk of hepatotoxicity [ 88]. Also, the ABCC10 (MDR7) polymorphism rs2125739 has been associated with plasma concentrations of NVP.

Efavirenz (EFV)

Oseltamivir

Oseltamivir targets the neuraminidase distributed on the surface of the influenza virus [ 92]. Several clinical trials are still evaluating the effectiveness of oseltamivir in treating SARS-CoV-2 infection [ 93]. Oseltamivir needs to be activated by carboxylesterase 1 (CES1) into its active metabolite, oseltamivir carboxylate [ 94]. G143E variants were reported to be 3.7%, 4.3%, 2.0% and 0% in White, Black, Hispanic and Asian populations, respectively [ 95]. A clinical study showed that G143E heterozygotes exhibited 18% greater AUC of oseltamivir and 23% smaller AUC ratios of oseltamivir carboxylate to oseltamivir compared to individuals with the 143GG genotype [ 96]. Significant inter-individual variability in oseltamivir PK and in antiviral effects have been consistently reported in clinical studies [ 97]. CES1 and ABCB1 genetic variants have the potential to serve as valid biomarkers for the prediction of oseltamivir activation and the optimization of oseltamivir pharmacotherapy [ 98].

Remdesivir

Biological Drugs

Anakinra

Anakinra is a biologic medicine used in the treatment of rheumatoid arthritis (RA) in combination with methotrexate. Anakinra inhibits the IL-1α and IL-1β and has been used with some success in several small studies in patients with COVID-19 [ 101]. A relationship between the infrequent IL-1a + 4845 G/T polymorphism and a significant better response to anakinra treatment was reported [ 102].

Tocilizumab (TCZ)

Treatment with TCZ may reduce the risk of invasive mechanical ventilation or death in patients with severe COVID-19 pneumonia [ 103]. In vitro studies in hepatocytes have shown that TCZ blocks the downregulation of CYP450 (mainly CYP3A4) that is caused by IL6 [ 104]. Several genetic biomarkers have been associated with the efficacy of TCZ in RA, including FCGR3A, IL6R, CD69, and GALNT18 [ 105]. The only genetic variants potentially involving TCZ's PKs are in the FCGR3A gene. In 87 patients with RA treated with TCZ, FCGR3A rs396991TT genotype showed higher response at 12 months. Polymorphisms of IL6R are considered to affect the intracellular signaling pathway of IL-6 receptor bound to TCZ [ 106]. In contrast, variants in CD69 and GALNT18 are thought to have limited direct effects on TCZ. Genetic variation in IL6R may aid in predicting TCZ therapy outcome in COVID-19 patients. To date, no pharmacogenetic testing is recommended for TCZ.

Eculizumab

Heme Oxygenase 1 (HO-1) up-regulators

Human HO protein has an important anti-inflammatory role in attenuating serious conditions like thrombosis, sepsis, tissue damage and fibrinogenesis, all of which are associated with SARS-CoV-2 infections [ 110]. The inducibility of HO-1 is regulated by the promoter region guanosine thymidine dinucleotide (GT)n repeats mutation [ 111]. Patients with COVID-19 complications have longer GT sequences [ 112]. Inducing HO-1 expression may prevent SARS-CoV-2-induced pulmonary complications [ 113].

Hemin, a substrate for HO-1 obtained from the breakdown of RBCs, is FDA approved for treatment of porphyria and is effective in blocking Zika viral replication [ 114]. The hemin-induced HO-1 cytoprotective pathway appears as a consistent target to control COVID-19. Heme arginate increases HO-1 levels by inhibiting delta-aminolevulinate synthase and so it can improve inflammation and viral infections [ 115]. Heme arginate is able to induce CYP2D6 and CYP3A4 [ 116]. CQ, HCQ, azithromycin, and remdesivir decrease heme production, in part, by inhibiting CYP induction, thus decreasing the demand for heme. These drugs also display interactions with the CYP system, which make maintaining safe effective therapeutic drug levels a challenge. Up-regulation of HO-1 is especially important in COVID-19 patients with the longer GT allele HO-1 polymorphism, and those with CYP2D6 polymorphisms that lead to supra- or sub-therapeutic drug levels. A synergistic anti-inflammatory effect may be obtained by the combination of heme arginate with repurposed anti-COVID-19 drugs that are not metabolized by CYP2D6/3A4. Recently, the glucocorticoid dexamethasone was found to save many severely ill COVID-19 patients [ 117]. Dexamethasone reduces hemolysis and induces HO-1 in macrophages [ 118], leading to attenuation of the severity of disease in COVID-19 patients. There are a number of naturally occurring substances that are capable of upregulating HO-1 [ 119] such as thymoquinone, neem leaf extract, resveratrol and curcumin.

Inhibitors of the renin-angiotensin-aldosterone system (RAAS)

There are some pharmacogenetic predictors of disposition and response of RAAS inhibitors [ 120]. Losartan, an ACE receptor blocker and is metabolized by CYP2C9 [ 121]. Genotyping some of Cyp 2C9 polymorphisms may affect losartan clinical benefits. The most common reduced-function variants are CYP2C9*2 (Arg144Cys), and CYP2C9*3 (Ile359Leu). CYP2C9 genotyping could be beneficial for dose adjustment. Other pharmacogenetic biomarkers, namely ABCB1 gene variants, could be useful predictors of losartan response [ 122]. The most relevant polymorphisms in ABCB1 are C3435T (rs1045642), G2677T/A (rs2032582) and C1236T (rs1128503) [ 123]. Regarding ACE inhibitors, ACE rs1799752 was related to variability in ACE inhibitors [ 124, 125]. This polymorphism consists of a 50-nucleotide deletion (del). Patients with the del/del diplotype correlated with a worse clinical outcome. The best pharmacogenetic predictor for spironolactone effectiveness is rs4961, located in the alpha-adducin gene, which predicts drug response in combination with furosemide [ 126]. Carriers of the G allele exhibited a better response to therapy compared with T allele carriers.

Anthelmintics

Ivermectin

Ivermectin has the potential to prevent viral replication of a broad spectrum of viruses. It has shown inhibition against SARS-CoV-2 in vitro through inhibition of Importin α/β1 (IMPα/β1)-mediated nuclear import of viral proteins [ 127]. Ivermectin is metabolized by CYP3A4. Ivermectin is both a substrate and a potent inducer of the P-gp. P-gp inhibitors can increase ivermectin plasma levels [ 128].

Nitazoxanide

Nitazoxanide and its active metabolite, tizoxanide have demonstrated potent activity against SARS CoV-2 and MERS CoV in Vero E6 cells. Nitazoxanide upregulates the innate antiviral mechanisms by broadly amplifying cytoplasmic RNA sensing and type I IFN pathways [ 85]. Metabolism of nitazoxanide occurs via hydrolysis and then conjugation via glucuronidation. Nitazoxanide has a very favorable drug interaction profile with no known clinically significant drug interaction concerns. So far, no pharmacogenetic studies regarding efficacy or toxicity of nitazoxanide were rported.

Conclusions

Currently, no direct evidence of PGx data in patients with COVID-19 is available. There are clear mechanisms by which genetic determinants may alter the therapeutic outcome of the current repurposed drugs for COVID-19. There is a need to do more PGx studies for COVID-19 repurposed therapies to establish evidence-based guidelines for genetic testing. The article identifies some potential associations between genetic variants and clinical outcomes of COVID-19 therapy. Incorporating the knowledge of PGx in the prospective clinical investigations of repurposed drugs during COVID-19 therapy is necessary to achieve safe and effective dosing and to reduce severity of adverse effects.

Author information

Affiliations

1. Clinical Pharmacy Practice Department, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt

Osama A. Badary

2. Clinical Pharmacy Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt

Osama A. Badary

Corresponding author

Correspondence to Osama A. Badary.

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Conflict of interest

The author declares that he has no conflict of interest.

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Badary, O.A. Pharmacogenomics and COVID-19: clinical implications of human genome interactions with repurposed drugs. Pharmacogenomics J 21, 275-284 (2021). https://doi.org/10.1038/s41397-021-00209-9
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DOI: https://doi.org/10.1038/s41397-021-00209-9

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Pharmacogenomics and COVID-19: clinical implications of human genome interactions with repurposed drugs - The Pharmacogenomics Journal

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The outbreak of Coronavirus disease 2019 (COVID-19) has evolved into an emergent global pandemic. Many drugs without established efficacy are being used to treat COVID-19 patients either as an offlabel/compassionate use or as a clinical trial. Although drug repurposing is an attractive approach with reduced time and cost, there is a need to make predictions on success before the start of therapy.

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Olá, pessoal! Espero que esteja tudo bem com vocês.

Para aumentarmos nosso conhecimento sobre produtos naturais e drug discovery, trouxe um artigo de revisão que possui até o momento 457 citações e trata de maneira geral como a descoberta de medicamentos para a próxima geração foi possível devido à exploração de produtos naturais à base de plantas juntamente com a inovação tecnológica.

Quer saber mais sobre quais produtos e tecnologias foram analisados? Então dá uma lida no artigo anexado :D

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Caracterização #farmacogenômica e o câncer gástrico  

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Caracterização #farmacogenômica e o câncer gástrico  

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Olá, pessoal! Espero que esteja tudo bem com vocês.

O artigo que trouxe sobre farmacogenômica foi publicado dois anos atrás em inglês (bom para treinar a capacidade leitora de outras línguas de vocês) e tem como principal foco a farmacogenômica do câncer gástrico. Os autores partem do ponto da dificuldade de tratamento enfrentada pelos pacientes com tumores sólidos gástricos, devido a este últimos, na maioria das vezes, possuírem diversas alterações genéticas. Assim, eles construíram um conjunto de dados de derivados dos pacientes anotados molecularmente associado com perfis farmacológicos para 60 agentes sinalizados, para que assim fosse possível descobrir interações farmacogenômicas em cânceres do tipo gástrico.

Para saber mais como foi feito esse estudo, é só ler o arquivo anexado ;)

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O aumento da produção de dados como uma faca de dois gumes na descoberta e fabricação de medicamentos #Drugdiscovery

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O aumento da produção de dados como uma faca de dois gumes na descoberta e fabricação de medicamentos #Drugdiscovery

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Esse artigo fala sobre os problemas e avanços na manutenção de dados gerados no processo de drug discovery e a necessidade de ferramentas para o processamento e armazenamento desses dados de forma que eles fiquem acessíveis para consultas futuras.

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Advancements in analytics have significantly increased the amount of data that is generated throughout the biologic drug lifecycle. This increased data flow presents challenges to managing the information. Managing the increased output is best achieved with the help of automated analytical workflows, which can organize data collection and streamline analyses.

Incorporating automation into the workflow

The biopharma industry has seen a significant increase over the past few years in the complexity and variety of biomolecular therapies. Manufacturers have found themselves often facing situations in which existing platforms and prior knowledge no longer apply to newer molecular formats, says Xiao Dong, marketing manager, Biopharmaceutical Business, Waters Corporation. As a result, larger-scale analytical testing is needed, especially during earlier-stage development, to minimize the risks associated with manufacturability and quality, Dong states.

"Automated analytical workflows allow manufacturers to address the gap between existing analytical capability and increased testing needs by reducing resource costs and improving turnaround time. In addition, automation improves data quality and reduces FTE [full-time employee] resource needs, leading to cost benefits as well as reduced compliance risks," says Dong.

The drug discovery and development process involves a series of complex stages that take 12-15 years to commercialize and cost between $0.9 billion and $2 billion, with a low success rate, says Anis H. Khimani, PhD, senior strategy leader, Pharma Development, Life Science, PerkinElmer. "Workflows within every stage contribute to large volumes of data that require management and interpretation, for both small- and large-molecule drug development," Khimani says.

Over the past two decades, the discovery and development of large-molecule therapeutics has seen significant progress in the areas of target characterization, screening, process optimization, automation, and analytics, Khimani explains. Implementation of automation and analytics across biologics workflows has played a key role in this success; they have enhanced productivity and are overcoming big data management challenges.

"Automation and data management deliver accuracy and reproducibility as well as enhance data quality and biological relevance. Furthermore, more recent advancements in artificial intelligence (AI) and machine learning have enabled predictability and process design," Khimani points out.

In the drug target identification (ID) and drug discovery space, next-generation sequencing (NGS) has revolutionized target discovery across the genome, exome, and transcriptome paradigm, while bioinformatics capabilities have enabled panel design for specific disease areas and the screening of disorders at the population genomics level, Khimani emphasizes.

Moreover, automation solutions in liquid handling and nucleic acid sample preparation continue to empower scientists in achieving higher throughput, accuracy, and reproducibility along the target ID workflows, Khimani adds.

"Drug discovery involving large-molecule screening has benefited significantly from automation and leveraging analytics. Integrating a workflow through interface and protocol configurations enables each step involving related instrument(s), software, and consumables to offer a seamless process, data generation, data interpretation, and biological evaluation," he states.

Regarding protein characterization, the implementation of automation workflows and AI tools has accelerated protein characterization and process development by enabling critical quality attributes (CQAs) and streamlining integration. According to Khimani, capillary electrophoresis (CE) platforms with higher throughput, for example, have enabled lower sample requirement, superior resolution of isolated/separated proteins, and reliable characterization.

For process development and scale up, it is important to remember that CQAs for biologics involve cell culture and production process parameters as well as storage conditions to ensure stability along the workflow. "In this context, an important data analytic to monitor is long-term stability on three production batches. Temperature

mapping services (e.g., OneSource, PerkinElmer), can help biopharma operators monitor variations and maintain consistency supporting good laboratory practice (GLP)/good manufacturing practice (GMP) compliance," according to Khimani.

Meanwhile, fully automated reports and advanced techniques, such as wireless temperature probes, reduce human error, while software solutions support data visualization of stability studies. Other quality control measures, such as impurities testing, can be achieved using analytical tools such as chromatography and atomic and molecular spectroscopy, Khimani says.

Managing increased data output

Automation technologies are also key in helping to collect and organize increased data output, which facilitates data analyses. The integration and automation of workflows results in enhanced data output at every step, from configuration of integration through metadata management and eventually data analysis, visualization, and interpretation, Khimani points out. Over the past decade, the adoption of electronic lab notebooks (ELN) have facilitated the migration of data-related content from paper notebooks to electronic formats. These electronic formats manage unstructured and structured data and provide for subsequent analysis and visualization.

"The clustering and visualization of vast volumes of data enable scientists to gain biological insights into target characterization and validation. There has been increasing awareness that identifying and validating the right target upstream is critical to the screening and development of drug candidates downstream to further enhance the success rate of therapeutic molecules," Khimani explains.

Advanced analytics technologies (e.g., TIBCO Spotfire, PerkinElmer) offer data analysis and visualization capabilities for this workflow; these capabilities play a critical role in decision-making. Additionally, ELN technologies (e.g., Signals Notebook, part of the new PerkinElmer Signals Research Suite) can enable audit trail and security features to support 21 Code of Federal Regulations ( CFR) Part 11 (1) compliance within the biologics GMP environment. "Huge volumes of data either require database capabilities or a cloud environment that can be maintained on site or outsourced via third-party informatics solutions. Implementation of Biopharma 4.0 is being adopted and driven by the principles of Industry 4.0 to improve efficiency, facilitate real-time monitoring, reduce cost, enhance predictability, and allow for better decision-making within bioprocess workflows," emphasizes Khimani.

Some of these advanced automated technologies are leveraged both upstream in drug discovery and development as well as downstream in bioprocess development and manufacturing; however, the requirements differ, Khimani points out. He explains that discovery workflows upstream seek flexibility and an open format to organize and develop protocols followed by management of structured data. "Research scientists may need to vary experimental conditions to optimize protocols into SOPs [standard operating procedures] as well as analyze a wide array of data for biological relevance," he says.

An ELN notebook (e.g., Signals Notebook, PerkinElmer), for instance, provides the latitude to manage metadata and analyze various groups of experimental data into visualization formats to enable decision-making. Biopharma research groups leverage the capabilities of ELN to optimize workflows to enable discovery and validation of disease-specific targets as well as the development of large-molecule therapeutics.

Meanwhile, further downstream in drug development, these advanced technologies also facilitate validation and security requirements within the GLP and GMP environments. ELN notebooks (e.g., Signals Notebook, PerkinElmer) can offer security-driven administration and audit capabilities. In the manufacturing environment, scale up for higher production volumes and GMP compliance are key. "Therefore, downstream it is important for analytics technologies to support automation, as well as provide electronic compliance supporting capabilities for biopharma to be able to meet regulatory requirements. Bioprocess workflows have continued to migrate from a batch process to continuous manufacturing; hence, there is a constant demand in this space for technologies to offer real-time monitoring and accuracy to maintain production that is devoid of errors and meets scale, sterility, and safety requirements," Khimani says.

Gunnar Schaefer, co-founder and chief technology officer of Flywheel, a research data management platform, notes the importance of having end-to-end solutions to streamline data ingested from multiple sources and curate it to common standards. Focusing on the facilitation of large-scale organization, processing, and analyses of complex data, such as annotated biomedical images frequently collected as part of clinical trials, can enable real-world data collaboration, machine learning, and AI development, all of which can accelerate drug discovery, Schaefer says.

Historically, for instance, most data assets collected in clinical trials were archived and largely forgotten, often stored with partners offsite, Schaefer observes. "With the broad adoption of machine learning, these data assets have gained a second life. However, many data archives are offline or otherwise inaccessible, poorly organized, and seldom quality-controlled," Schaefer states.

Addressing those problems head on, starting with flexible and scalable data ingestion and establishing a de-identification framework as well as having a customizable and multi-modal data processing automation and structured annotation options, goes a long way towards optimizing analytical workflows. "In concert, these capabilities accelerate [the] path to meaningful data at scale," Schaefer explains.

Khimani adds that bottlenecks in data collection and processing exist at every step of the workflow, with greater challenges arising when higher volumes of data are generated from automation and real-time monitoring of the process. He points out that multiple factors contribute to data overload in the process development and scale-up environment, such as the evaluation of process parameters, raw material requirements, and monitoring along the workflow, including product stability, media components, and microbial presence. Additionally, data across the workflow is obtained and sorted manually using accessory tools or devices.

"Further contributing to bottlenecks is the use of complex spreadsheets. [In addition,] locally developed or third-party software may be utilized to collect and process data. These programs can be labor- and time-intensive and may result in errors," Khimani says.

"Automation across workflows with centralization of informatics tools to manage data can alleviate these bottlenecks," Khimani continues. "Subsequently, data can be structured, tracked, and processed for visualization, as well as archived for future reference." Furthermore, adoption of the holistic automation tenets of Industry 4.0 with enhanced process technologies, as well as advanced digital solutions, can alleviate numerous bottlenecks. Having an automation roadmap such as this aims to deliver enhanced robustness and reproducibility of quality metrics and can significantly reduce cost, provide flexibility, and enhance productivity, Khimani concludes.

Facilitating implementation

Automating the entire analytical workflow often requires a manufacturer to integrate solutions from different vendors. This often requires steep learning curves, cautions Dong. Thus, working closely with different vendors while having a cross-functional team that can work on data and system integration are essential requirements.

"Automated platforms need to be flexible, because the number of samples can vary. The platforms themselves should not be complex or hard to operate as many of these scientists are not automation engineers," explains Dong. "Easy-to-use platforms with simple, user-friendly informatic interfaces will be critical to successful implementation. Additionally, it is often a good practice to start implementing automation in non-GMP development settings before GMP manufacturing, which has higher compliance needs."

Furthermore, automated analytical workflows require access to large-scale, standardized, quality-controlled, and expert-labeled datasets, adds Schaefer. At the same time, data privacy and security requirements are becoming ever stricter. A comprehensive data management and sharing framework would allow researchers to focus on new discoveries, rather than solving information technology problems, Schaefer notes.

Although the level of automation and data management across analytical workflows differs between a laboratory setting and a bioprocess environment in terms of the scale and compliance requirements, there are important common themes, says Khimani. These common themes include streamlined workflows, standardization of protocols, and reproducibility.

The main components required to allow the implementation of fully automated analytical workflows, either in the laboratory setting or in a commercial biomanufacturing setting, include workflow integration, informatics capabilities, standardization, quality control programs, and digitization, Khimani states.

Workflow integration includes a customized configuration using informatics capabilities, which translate protocols interfacing from one step-or from an analytical instrument of the workflow-to the next. This configuration is designed to enable walk-away automation with the least manual intervention, according to Khimani.

Khimani also explains that, at an enterprise level, an organization requires informatics solutions that are either cloud-based, local databases, or laboratory-level laboratory information management systems (LIMS) platforms for the management of various instrumentation and data communication. Standard software tools to enable data analysis and visualization are useful at the end-user level, Khimani points out. A laboratory informatics footprint allows security-based central monitoring of analytical workflows, data management and archiving, root cause analysis (RCA), and enhanced productivity and cost-savings.

Having reference standards programs across hardware calibration, reagents, and consumables can establish uniformity across workflows. Most importantly, such standards enable reproducibility, reliability, and monitoring of results for errors and deviation. Timely qualification and calibration of instruments and tools is critical to maintaining reliability. The use of appropriate reference standards or controls for assay and diagnostic reagents establishes quality control for the consumables and the entire assay, says Khimani.

Ensuring monitoring as well as identification and control of any deviations for quality control requires a disciplined and systems approach that proactively establishes workflow and process design requirements (e.g., quality by design established within drug manufacturing) across laboratories and scale-up environments. Any further deviations can also be managed via RCA. Moreover, in biomanufacturing, RCA, can point to whether critical process parameters (CPPs) and CQAs are being met.

In addition to informatics capabilities, empowering the laboratory-and the bioprocess ecosystem in particular-with digitization and AI capabilities enables continuous manufacturing, real-time monitoring, process predictability, and superior control of the workflows, emphasizes Khimani. He explains that data captured at every step from this streamlined digitization can be analyzed to develop both real-time and predictable models to ensure CPPs and delivery of CQAs.

Reference

1. CFR Title 21, 11 (Government Printing Office, Washington, DC).

About the author

Feliza Mirasol is the science editor for Pharmaceutical Technology.

Article Details

Pharmaceutical Technology
Volume 46, Number 2
February 2022
Page: 36-39, 47

Citation

When referring to this article, please cite it as F. Mirasol, "Increased Data Output is a Double-Edged Sword in Drug Discovery and Manufacturing," Pharmaceutical Technology 46 (2) 36-39, 47 (2022).

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Increased Data Output is a Double-Edged Sword in Drug Discovery and Manufacturing

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Advancements in analytics have significantly increased the amount of data that is generated throughout the biologic drug lifecycle. This increased data flow presents challenges to managing the information. Managing the increased output is best achieved with the help of automated analytical workflows, which can organize data collection and streamline analyses.

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Raça e a farmacogenômica - Medicina personalizada ou prática equivocada? #farmacogenomica

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Raça e a farmacogenômica - Medicina personalizada ou prática equivocada? #farmacogenomica

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Esse artigo traz uma discussão bem interessante sobre o uso de raças na medicina personalizada e mostra que algumas suposições sobre o uso de certos medicamentos em determinadas etnias podem acabar sendo errôneos.

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Oi gente, além dos outros artigos, trouxe esse sobre o extrato de própolis, eu usei esse medicamento quando tive uma crise de garganta que fiquei sem conseguir beber água, juntamente com antibiótico, esse combo me ajudou bastante. [continua] #drugdiscovery 

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Oi gente, além dos outros artigos, trouxe esse sobre o extrato de própolis, eu usei esse medicamento quando tive uma crise de garganta que fiquei sem conseguir beber água, juntamente com antibiótico, esse combo me ajudou bastante. [continua] #drugdiscovery 

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Então pensando sobre o assunto, pesquisei algumas aplicações do uso do extrato, achei dois estudos interessantes, um fala sobre a atividade antimicrobiana do extrato de própolis frente à Staphylococcus spp. e outro relacionado a saúde bucal, uma revisão. Espero que gostem!
Segundo para baixas o PDF: https://www.scielo.br/j/pvb/a/zqjNpQhDR3swwDL5BpBN3gb/abstract/?lang=en#

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Abstract

Ethnopharmacological relevance

The antimicrobial potential of propolis - a honey bee product - was correlated with its traditional use as a natural medicine, mainly known for antimicrobial and antioxidant properties. Moreover, research on natural products in dentistry has increased in recent years in the search for products with greater therapeutic activity, lower toxicity, better biocompatibility, and more affordable cost to the population.

Objective

Considering that the beneficial effect of propolis is acknowledged for several oral conditions, this study aimed to synthesize the research and technological forecasts of existing evidence on the use of propolis extract as a potential antimicrobial agent in dentistry.

Methods

Studies were identified through an investigation in the PubMed, Web of Science, Scopus, and Scielo electronic databases. Additionally, the following patent databases were screened: Google Patents, WIPO, INPI, Espacenet, and Questel Orbit. The data were tabulated and analyzed using Microsoft Office Excel 2013 and Questel Orbit.

Results

A total of 174 scientific articles and 276 patents fulfilled all the criteria and were included in the investigation. The highest number of patents (n = 144) was produced by China. Additionally, the most prevalent studies were performed on an experimental basis (72%), followed by clinical studies (n = 27) and review articles (n = 21). The effect of using propolis has been extensively observed in oral care products, periodontics, pathology, and cariology, among other dental specialties.

Conclusion

It was possible to identify the current scientific and technological scenario of the application of propolis in dentistry, with the number of patents increasing in recent years. However, all studies related to the use of propolis in dentistry have shown a potentially safe antimicrobial agent in an extensive field of application.

Introduction

The oral biofilm is rich in microorganisms, including bacteria and fungi, which under favorable conditions may be harmful to health. For combating these oral health problems, there are various antibiotics and antifungals and synthetic or natural drugs (Bezerra et al., 2015; Brown et al., 2016). The number of studies with natural products is increasing because of the possibility to obtain bioactive elements that may be used for both therapeutic purposes and the development of medicines with applications in dentistry (Ahangari et al., 2018; Ishida et al., 2011). Although there is scientific evidence proving the effectiveness and obvious advantages of phytotherapy, such as lower toxicity, better biocompatibility, and potentially more affordable cost to the population (Almeida et al., 2016), it is still discriminated against by health professionals. One solution could be the development of evidence-based patents to validate its use in the population.

Propolis is a non-toxic natural substance with multiple pharmacological properties, including anti-cancer, antioxidant, fungicide, antibacterial, antiviral, and anti-inflammatory, among others (Andrade et al., 2017; Agarwal et al., 2012; Barrientos et al., 2013; Brown et al., 2016; Peycheva et al., 2019). Several studies report the use of this substance in pharmaceutical, medicinal, veterinary, and dental fields, and the results have proven its pharmacological activities (Bruschi et al., 2017; de Luca et al., 2017; de Rezende et al., 2008). Propolis has shown effects such as reduced inflammatory response, improved immune system (Asawahame et al., 2015; Badea et al., 2013; de Rezende et al., 2008), and an important antimicrobial effect (Abbasi et al., 2018; Arafa et al., 2018; Brown et al., 2016; de Rezende et al., 2008; Kim et al., 2019; Veloz et al., 2019) that further extends the potential use of propolis in dentistry and its commercialization (Furtado Jr. et al., 2018).

The strategic application of scientific and technological information on the use and formulation of propolis extracts may provide opportunities for science-based technologies aligned with public policies to stimulate innovation. There is a trend towards the application of phytochemicals with pharmacological activity in dentistry, but the effectiveness has not been completely elucidated. Therefore, this scoping review proposed to identify and compile the scientific and technological evidences regarding the antimicrobial activity of propolis extracts, as well as advances in research and prospects for the development of herbal medicines for dental use.

Section snippets

Study selection

The search initially retrieved 2415 scientific articles and, after removing the duplicates, 2092 studies were selected. After reading the titles and abstracts, 1915 studies were excluded (Fig. 1). Out of 177 studies selected, three were excluded for not meeting the eligibility criteria, as they were not related to antimicrobial application. After carefully analyzing the full texts, 174 studies were selected. Moreover, the patent database search initially identified 3975 patents. After removing

Acknowledgements

This study was financed in part by the Coordination for the Improvement of Higher Education Personnel (CAPES) - Finance Code 001. The authors would like to thank CAPES for granting a scholarship to the first author. They are also grateful to CNPq (National Council for Scientific and Technological Development) for the [grant number 309848/2017-2] and scholarships provided to the last author.

References (53)

Evaluation of chemical composition and efficacy of Chinese propolis extract on Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans: an in vitro study

Antibacterial activity and inhibition of adherence of Streptococcus mutans by propolis electrospun fibers

Chemical and botanical characterization of chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus

View more references

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The CsAqEx inhibited the migration of leukocytes at the doses of 25, 50, and 100 mg/kg. The CsAqEx showed anti-inflammatory activity after the intraplantar injection of carrageenan, presenting a reduction in edema formation at all tested doses (12.5, 25, 50 and 100 mg/kg). The dose of 12.5 mg/kg of CsAqEx prevented edema formation after intraplantar injection of histamine. In an organ bath, 729 μg/mL of CsAqEx did not promote spasmolytic effect on isolated mice tracheal rings contracted by carbachol (CCh) or potassium chloride (KCl). We did not observe clinical signs of toxicity in the animals after acute treatment with CsAqEx, which suggested that the median lethal dose (LD ₅₀) is greater than 1000 mg/kg. Repeated dose exposure to the CsAqEx did not produce significant changes in hematological, biochemical, or organ histology parameters.

The results suggest that the anti-inflammatory effect of CsAqEx is related to the reduction of vascular extravasation and migration of inflammatory cells, without effects on the central nervous system. Moreover, there was no spasmolytic effect on airway smooth muscle and no toxicity was observed on mice.

Flavonoids interact with multiple targets in Central Nervous System resulting in a broad neuroprotection mediated by complementary processes and synergic interactions. Therefore, flavonoid-based therapies may input positive outcomes in the prevention and early management of neurodegenerative diseases. In Brazilian folk medicine Trichilia catigua is used for its neuroactive properties, such as neurostimulant, antioxidant and anti-neuroinflammatory, while Turnera diffusa is traditionally used as a tonic in neurasthenia. Both species are known to be rich in flavonoids.

To study aqueous extracts of T. catigua and T. diffusa in terms of their antioxidant and antiglycation effects, inhibition of tyrosinase activity, and interaction with enzymes and pathways engaged in neuroinflammation. Moreover, whenever possible, to establish a relationship between the studied activities and the traditional usage of the species.

The phenolic profiles of the aqueous extracts were validated by HPLC-DAD. The effect of the extracts over mushroom tyrosinase and 5-lipoxygenase activities, as well as their capacity to impair bovine serum albumin glycation, were assessed by i n vitro assays. The anti-neuroinflammatory potential of the same extracts was evaluated by their capacity to mitigate the pro-inflammatory stimulus induced in BV-2 microglia cells by interferon-gamma.

T. catigua extract, a rich mixture of phenolic acids, catechins and flavonolignans, excels by its ability to decrease lipid peroxidation (EC ₅₀ = 227.18 ± 9.04 μg/mL), and to work as anti-glycation agent, and inhibitor of both tyrosinase and 5-lipoxigenase (IC ₅₀ = 358.84 ± 19.05 and 56.25 ± 14.53 μg/mL, respectively). However, only T. diffusa extract, mainly composed by luteolin derivatives, is able to lower NO production by BV-2 microglia cells stimulated with interferon-gamma, despite its lower activities in the other assays.

Overall, this work highlights the value of medicinal plant extracts as sources of bioactive flavonoid-rich extracts with neuroactive effects. Furthermore, these results support their application as alternative strategies to develop functional foods and therapeutics to fight chronic neurodegenerative disorders.

The flower buds of Sophora japonica L. are a major traditional medicine in China, Japan, and Korea and are used to stop bleeding and 'cool the blood'. Accordingly, they are used to treat bleeding haemorrhoids, hypertension, and pyoderma. In addition, it was recently found that the flower buds of S. japonica (SJ) have cosmetic whitening properties.

Compounds in SJ and their targets and related diseases were investigated using the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and analysis platform. Target gene information was obtained from the UniProt database. Network construction was carried out using Cytoscape 3.72. Contact dermatitis (CD)-related gene searching was performed using the Cytoscape string App. Docking analysis was conducted using AutoDock Vina. Six-week-old Balb/c male mice with DNFB (1-fluoro-2,4-dinitrofluorobenzene)-induced CD were treated with a methanol extract of the flower buds of S. japonica (MESJ), and its effects on skin colour, lesions, and immune cell infiltration, and on histopathological abnormalities such as epidermal hyperplasia were investigated.

Eleven compounds targeted 13 CD-related genes, that is, serum albumin (ALB), prostaglandin G/H synthase (COX) 2, C-X-C motif chemokine (CXCL) 2, CXCL10, ICAM1, IFN-γ, IL-10, IL-1α, IL-1β, IL-2, IL-6, E-selectin, and TNF. In the murine DNFB model, MESJ significantly suppressed scaling, erythema, and skin thickening as compared with DNFB controls and epithelial hyperplasia and immune cell infiltrations induced by repeated DNFB application.

Our animal study showed that the mode of action of MESJ was closely related to the prevention of epithelial hyperplasia and immune cell infiltration. The results obtained demonstrated that the flower buds of S. japonica offer a potential means of treating CD, and suggest that the therapeutic mechanism of CD is explained by relations between 11 major components of SJ, including kaempferol and quercetin, and 13 CD-related genes.

This review documents the wide and varied repertoire of traditional practices and remedies based on the use of domestic animals in Spanish ethnoveterinary medicine (EVM) from the early 20th century to the present. Empirical practices, both ritual and magical, are recorded, and these EVM data are compared with those of other countries in the Mediterranean region and Latin America. The data collected here could form a scientific foundation for future inventories of local veterinary knowledge (LVK) and research addressing the discovery of new drugs for livestock and the validation of the effects.

A qualitative systematic review of the most important databases in the fields of ethnobiology, ethnoveterinary medicine, folklore and ethnography was performed. Information and use-reports were obtained from more than 60 documentary sources.

We recorded the use of nine domestic animal species and one hybrid (the mule) and a total of 171 empirical remedies based on the use of a single species. A wide diversity of body parts or derivative products were/are used. Fat was/is the most commonly used product, being used in 71 remedies (42%). These zootherapeutic resources were/are used to treat or prevent a total of 69 animal diseases or medical conditions, in particular dermatological, reproductive and digestive ailments, together with some infectious diseases. Sheep, cattle, goats and equines form the group of domestic animals in which the greatest number of useful species is employed. In addition, many remedies and practices of the magical-religious type are documented. In comparison with other culturally related areas, there is a greater parallelism in the animals and body parts and derivative products used, and the ailments treated.

Contemporary Spanish EVM practices amass a great richness of domestic animal-based remedies. A diversity of body parts or derivative products has been used, offering a cultural heritage that could be a fundamental step in the discovery of new and low-cost drugs for treating livestock and alternative materials for pharmaceutical purposes, and it can contribute to the creation of new strategies for the conservation of natural resources and management of endangered species. The usage of zootherapeutic products derived from wild animals can be replaced by the use of products isolated from domestic animals. Finally, this overview contributes to the inventory of some uses, traditional practices and rituals seriously threatened by the progressive loss of LVK.

Polygonum multiflorum Thunb.(PM), (known as Heshouwu (何首乌) in China) is one of the most important and well mentioned Chinese medicinal herbs in the literature for its use in blackening hair, nourishing liver and kidney, anti-aging, anti-hyperlipidemia, antioxidant, anti-inflammatory, anticancer, hepatoprotection, cardio-protection and improving age-related cognitive dysfunction. The purpose of this review is to give a comprehensive and recent update on PM: new compounds or isolated for the first time, potential hepatotoxic compounds and their mechanisms. Moreover, future perspectives and challenges in the future study of this plant are conversed which will make a new base for further study on PM.

A comprehensive review of relevant published literature on PM using the scientific databases SCOPUS, PubMed, and Science Direct was done.

PM is broadly produced in many provinces of China and well known in other Eastern Asian Countries for its ethno-medical uses. Previous phytochemical investigation of PM had led to the isolation of more than 175 compounds including recently isolated 70 new compounds. Most of the new compounds isolated after 2015 are majorly dianthrone glycosides and stilbene glycosides. Processing has also a significant effect on chemical composition, pharmacological activities, and toxicity of PM. PM-induced liver injury is increasing after the first report in Hong Kong in 1996. Hepatotoxicity of PM was constantly reported in Japan, Korea, China, Australia, Britain, Italy, and other countries although its toxicity is related to idiosyncratic hepatotoxicity. More interestingly, although there is indispensable interest to predict idiosyncratic hepatotoxicity of PM and understand its mechanisms, the responsible hepatotoxic compounds and mechanisms of liver damage induced by PM are still not clear. There is a big controversy on the identification of the most responsible constituent. Anthraquinone and stilbene compounds in PM, mainly emodine and TSG are mentioned in the literature to be the main responsible hepatotoxic compounds. However, comparing the two compounds, which one is the more critical toxic agent for PM-induced hepatotoxicity is not well answered. Affecting different physiological and metabolic pathways such as oxidative phosphorylation and TCA cycle pathway, metabolic pathways, bile acid excretion pathway and genetic polymorphisms are among the mechanisms of hepatotoxicity of PM.

Deeper and effective high throughput experimental studies are still research hotspots to know the most responsible constituent and the mechanism of PM-induced hepatotoxicity.

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Are propolis extracts potential pharmacological agents in human oral health? - A scoping review and technology prospecting

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The antimicrobial potential of propolis - a honey bee product - was correlated with its traditional use as a natural medicine, mainly known for antimicrobial and antioxidant properties. Moreover, research on natural products in dentistry has increased in recent years in the search for products with greater therapeutic activity, lower toxicity, better biocompatibility, and more affordable cost to the population.

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Oi pessoal, esse artigo trata-se de uma revisão sobre as interações disponíveis do genoma humano com alguns medicamentos reaproveitados promissores para o gerenciamento do COVID-19. Levantando em pauta novamente o uso de cloroquina e outros medicamentos como azitromicina, remdesivir e ivermectina, perfeito para uma leitura e depois uma postagem no grupo da família! #farmacogenomica 

# data[].attributes.subject
Oi pessoal, esse artigo trata-se de uma revisão sobre as interações disponíveis do genoma humano com alguns medicamentos reaproveitados promissores para o gerenciamento do COVID-19. Levantando em pauta novamente o uso de cloroquina e outros medicamentos como azitromicina, remdesivir e ivermectina, perfeito para uma leitura e depois uma postagem no grupo da família! #farmacogenomica 

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Abstract

The outbreak of Coronavirus disease 2019 (COVID-19) has evolved into an emergent global pandemic. Many drugs without established efficacy are being used to treat COVID-19 patients either as an offlabel/compassionate use or as a clinical trial. Although drug repurposing is an attractive approach with reduced time and cost, there is a need to make predictions on success before the start of therapy. For the optimum use of these repurposed drugs, many factors should be considered such as drug-gene or dug-drug interactions, drug toxicity, and patient co-morbidity. There is limited data on the pharmacogenomics of these agents and this may constitute an obstacle for successful COVID-19 therapy. This article reviewed the available human genome interactions with some promising repurposed drugs for COVID-19 management. These drugs include chloroquine (CQ), hydroxychloroquine (HCQ), azithromycin, lopinavir/ritonavir (LPV/r), atazanavir (ATV), favipiravir (FVP), nevirapine (NVP), efavirenz (EFV), oseltamivir, remdesivir, anakinra, tocilizumab (TCZ), eculizumab, heme oxygenase 1 (HO-1) regulators, renin-angiotensin-aldosterone system (RAAS) inhibitors, ivermectin, and nitazoxanide. Drug-gene variant pairs that may alter the therapeutic outcomes in COVID-19 patients are presented. The major drug variant pairs that associated with variations in clinical efficacy include CQ/HCQ ( CYP2C8, CYP2D6, ACE2, and HO-1); azithromycin ( ABCB1); LPV/r ( SLCO1B1, ABCB1, ABCC2 and CYP3A); NVP ( ABCC10); oseltamivir (CES1 and ABCB1); remdesivir ( CYP2C8, CYP2D6, CYP3A4, and OATP1B1); anakinra ( IL-1a); and TCZ ( IL6R and FCGR3A). The major drug variant pairs that associated with variations in adverse effects include CQ/HCQ ( G6PD; hemolysis and ABCA4; retinopathy), ATV ( MDR1 and UGT1A1*28; hyperbilirubinemia; and APOA5; dyslipidemia), NVP ( HLA-DRB1*01, HLA-B*3505 and CYP2B6; skin rash and MDR1; hepatotoxicity), and EFV ( CYP2B6; depression and suicidal tendencies).

Subject terms: Genetic association study, Drug development

COVID-19

COVID-19 background

The new pandemic coronavirus disease 2019 (COVID-19) is caused by the novel Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). COVID-19 is currently triggering enormous global demands on health systems and presents an unprecedented challenge to identify effective drugs for prevention and treatment [ 1]. Coronaviruses have a genome made of RNA. Viruses with RNA genomes have an essential gene called the RNA-dependent RNA polymerase (RdRp), which is highly conserved, meaning that there are few changes in the gene from one RNA virus to another [ 2]. SARS-CoV2 binds principally to the cell-membrane angiotensen converting enzyme 2 (ACE2) receptors through the viral structural spike (S) protein [ 3]. At the intracellular level, the virus activates cellular processes to produce viral proteins that replicate the virus's genetic material, providing potential targets for drug therapy [ 4].

COVID-19 therapy

In an urgent attempt to mitigate devastating catastrophe of SARS-CoV2, many drugs without established efficacy have been used in patients either as an offlabel/compassionate use or as a clinical trial [ 5- 8]. A combination of antivirals with different mechanisms of action may be more effective but at the same time, their adverse effects should not be underestimated [ 9, 10]. Mechanistic and in vitro analyses suggest multiple promising therapeutic options with potential for repurposing to treat patients with COVID-19 [ 11]. Drug repurposing is an attractive approach with reduced time and cost to treat COVID-19 [ 12- 14]; however, limitations such as low success rate and the possibility of adverse side effects, can not be overlooked [ 13- 17]. There is limited data on the human genome interactions with many of these agents and this may constitute an obstacle for successful COVID-19 therapy. Knowing the major human genetic variants association with the clinical therapeutic outcome has the potential not only to expedite emergency use authorization and approvals but also to afford an additional level of safety and efficacy to patients. Therefore, the purpose of this review is to look at some drugs commonly used in regimens for COVID-19 and provides specific examples of how genetics may affect drug efficacy and toxicity. It adds to the efforts of recently published relevant articles [ 18- 20] and does not serve as an exhaustive review of all relationships between host genetics and these drugs.

Pharmacogenomics (PGx) overview

Genetic polymorphism

Genetic polymorphisms are a type of genetic diversity within a population's gene pool. Single nucleotide polymorphisms (SNPs), are the most common type of genetic variation among people. Various polymorphisms exist in genes encoding phase 1 cytochrome P450 (CYP) or phase 2 drug-metabolizing enzymes, transporters, drug targets, or human leucocyte antigen (HLA) alleles and predict drug efficacy or toxicity [ 21, 22]. Genetic variations of CYP2C9, CYP2D6, CYP2C19 and CYP3A5 were associated with therapeutic effects of phenytoin [ 23], tamoxifen [ 24], clopidogrel [ 25], and tacrolimus [ 26], respectively. The dose regimens of mercaptopurines and irinotecan should be adjusted according to the polymorphism of thiopurine methytransferase (TPMT) [ 27] and UDP glucuronosyltransferase 1A1 (UGT1A1) [ 28], respectively. A variant allele in the solute carrier organic anion transporter family member 1B1 (SLCO1B1) gene has been associated with statin-induced myalgia [ 29]. A common variant in the vitamin K epoxide reductase complex subunit 1(VKORC1) gene, has also been strongly associated with inter-individual warfarin dosing variability [ 29].

Pharmacogenetics and PGx

The genetic polymorphisms constitute the basis of pharmacogenetics which means the monogenic variants which alter the drug response [ 30]. The term pharmacogenetics was coined in 1957 [ 31]. On the other hand, PGx is the genome-wide analysis of genetic determinants of drug metabolizing enzymes, receptors, transporters, and targets that influence therapeutic efficacy and safety [ 32]. The realization that most variable drug responses appear to be multifactorial led to the rise of interest in PGx, a rise paralleled by the expansion of genetics into genomics.

Evidence-based PGx resources

The rapid innovation in sequencing technology and genome-wide association studies has led to the development of numerous data resources and dramatically changed the landscape of PGx research. Resources provided by organizations such as The Clinical Pharmacogenetics Implementation Consortium (CPIC) [ 27] and The PGx Knowledgebase (PharmGKB) [ 33], that use standardized approaches to evaluate the literature and provide clinical guidance, are essential for the implementation of pharmacogenetics into routine clinical practice. Important online resources such as PharmGKB.org and cpicpgx.org provide the clinician with summarized PGx associations and clinical guidelines. Other resources include SCAN and PACdb PGx databases developed and published by the PGx of Anticancer Agents Research Group. SCAN is designed to collect, annotate, and present the relationship between genotype and gene expression. It is a large-scale genetic and genomic database containing SNP and copy number variation annotations along with a web interface, a set of methods and algorithms, and some data mining tools [ 34]. PACdb is a pharmacogenetics-cell line database collecting pharmacology-related information including genotypes, gene expression, and pharmacological data gathered via lymphoblastoid cell lines [ 35].

PGx clinical implications and testing

In recent years, clinical evidence has strengthened, guidelines have emerged, and genomic medicine is becoming integrated into routine care for certain disease states, such as some cancers. Recently, the FDA approved direct-to-consumer tests for PGx, breast cancer risk, and propensity to develop certain conditions (e.g., Parkinson's and Alzheimer's diseases) [ 36]. A notable example is that CYP2C9 and VKORC1 genotypes predict different sensitivity and resistance frequencies in the Ashkenazi and Sephardi Jewish populations necessitating warfarin dose adjustment [ 37]. Many major medical institutions have started implementing genotyping protocols for preemptive pharmacogenetic testing [ 38]. A good example of a pharmacogenetic test is the association between a particular HLA allele (HLA-B*5701) and hypersensitivity reactions to abacavir [ 39]. Moreover, HLA-B*1502 screening is successful in patients who are prescribed carbamazepine, particularly in Asians. The HLAB*1502 allele is associated with carbamazepine-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) [ 27].

Repurposed anti-COVID-19 drugs

Chloroquine (CQ)and hydroxychloroquine (HCQ)

CQ and HCQ have been used to treat malaria for over 50 years. They were the first antiviral drugs officially indicated for COVID-19 in the U.S. as an FDA Emergency Use Authorization issued on March 28, 2020. This was later revoked on June 15, 2020 based on new data suggesting that the drug's potential benefits may not outweigh its known and potential risks [ 40]. However, a number of ongoing studies for both treatment and prevention of COVID-19 are still underway. HCQ and CQ inhibit major histocompatability complex (MHC) class II expression; production of IL-1, IFNα and TNF and interfere with cyclic GMP-AMP synthase activity partly by accumulating in lysosomes and autophagosomes of phagocytic cells and changing local pH concentrations [ 41]. CQ and HCQ were reported to be effective against SARS-CoV-2 with a 50% effective concentration (EC50) of 2.71 µM and 4.51 µM in Vero E6 cells, respectively [ 42].

SARS-CoV-2 uses ACE2 receptors expressed on host epithelial cells along with cofactor transmembrane protease, serine 2 (TMPRSS2) to enter the cell. HCQ and CQ inhibit virus entry by targeting the endosomal pathway. They increase the pH of endosomes and inhibit membrane fusion [ 43]. In addition, inhibition of SARS-CoV-2 could be partly due to differential glycosylation of both ACE2 and the spike protein [ 44]. Several variants in ACE2 including p.Met383Thr, p.Pro389His, and p.Asp427Tyr were identified in the African American and Latino American populations. These pathogenic variants in ACE2 may inhibit interaction with the S protein and could influence the clinical efficacy of HCQ or CQ [ 45]. The ACE2 receptor N720D variant may enhance TMPRSS2 activation and subsequent viral entry [ 46]. HCQ and CQ may only work for TMPRSS2-absence patients who are infected by SARSCoV-2, and may have less effect or no effect for the patients with wild-type TMPRSS2 [ 47].

In patients with COVID-19, CQ has been administered orally at a dose of 300 mg for adults, twice daily (bid) for a maximal duration of 10 days. HCQ therapy is started at a loading dose of 400 mg bid. on day 1 and then lowered to 200 mg bid (10 days average). A recent study showed that both drugs have favorable and unfavorable characteristics, but none showed clear evidence of benefit for early outpatient disease or prophylaxis [ 48].The most severe complications from use of HCQ and CQ include QTc prolongation and ventricular arrhythmias [ 49], which may pose a particular risk to critically ill patients. HCQ and CQ undergo N-dealkylation via CYP isozymes [ 50]. A few reports have described significance of gene polymorphisms in affecting HCQ or CQ treatment outcome. In African children with acute falciparum malaria, peak plasma CQ and DCQ concentrations were highly variable [ 51]. In malaria patients from Tanzania [ 52], India [ 53] and Sudan [ 54], the mean plasma CQ concentrations were higher in sensitive patients than in resistant patients. The carriers of CYP2C8-reduced activity alleles showed lower efficacy as compared with homozygous wild-type allele *1  A [ 55]. CYP2C8*4 is a missense mutation, which promotes a lower enzyme activity in vitro than the wild-type allele *1  A, and similarly CYP2C8*2 and CYP2C8*3 also present a markedly decreased activity in vitro [ 56]. Both CQ and HCQ are metabolized by hepatic cytochrome P450 CYP2D6, the expression of which varies among individuals as the result of genetic polymorphisms. High HCQ concentrations have been observed in individuals who are poor or intermediate CYP2D6 metabolizers (CYP2D6*4; CYP2D6*10) [ 57]. Both CQ and HCQ were reported to inhibit CYP2D6 activity [ 58]. They may potentiate other CYP2D6 substrates such as labetalol and carvedilol [ 59] and decrease the effectiveness of prodrugs reliant on CYP2D6 for activation such as codeine and tramadol [ 60]. There is no established clinical guidance related to CYP2D6 gene variants in CQ or HCQ use. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is most common in the Mediterranean area, in Europe, in Middle East, Asia and parts of Africa. Genetic variants affecting G6PD activity show remarkably individual and ethnical differences [ 61]. More than 160 G6PD genetic variants have been identified including G6PD B (wild type), G6PD A (non-deficient type) and G6PD A − (African deficient type). G6PD 376 G/202 A haplotype is the most common G6PD variants in sub-Saharan Africa [ 62]. CQ and HCQ use in individuals having genetic mutations in the G6PD may induce hemolysis and hemolytic anemia.

The blood group ABO gene encodes glycosyltransferases which determine addition of N-acetylgalactosamine or galactose to H antigen and subsequently determines A and B antigens. Vasku et al. [ 63] identified an association of blood pressure with ACE I/D polymorphism and ABO blood group. Genetic variation within Fucosyltransferase 2 (FUT2) has been studied extensively in the context of human exposure. Homozygotes for the nonsense mutation (rs601338 G > A) that inactivates the FUT2 enzyme are unable to secrete ABO(H) histo-blood group antigens or express them on mucosal surfaces [ 64]. An association between the A allele and COVID-19 prevalence/mortality was recently confirmed [ 65]. ABO blood group, Hb genotype and G6PD status showed no significant influence on CQ treatment outcome in Nigerian children with uncomplicated malarial infection, but there was greater risk of developing resistance to CQ in HbAA than HbAS individuals [ 66]. Another well-recognized adverse effect of HCQ and CQ is retinopathy, which occurs more frequently with long term use and higher doses. Retinopathy occurred less frequently in those with the minor allele of ATP-binding cassette (ABC) transporters ABCA4 c.5814 A > G [ 67]. CQ and HCQ should be used with caution especially in combination with other drugs or at high doses potentially with monitoring of RBC or hemoglobin levels and genetic testing should be recommended.

Azithromycin

This macrolide antibiotic is used extensively in patients with viral infections to prevent severe respiratory tract infections Azithromycin-HCQ combination shows a synergistic effect on Covid-19 disease [ 68]. The pharmacokinetics (PKs) of azithromycin are influenced by the activity of P-glycoprotein (P-gp) transporter encoded by ABCB1. Genetic variation in ABCB1 showed up to a twofold lower peak azithromycin concentrations in 20 healthy volunteers after a single dose [ 69]. Higher systemic exposure to azithromycin is of particular concern when it is combined with HCQ or CQ because of their additive effects on QTc prolongation.

Protease inhibitors

Lopinavir (LPV)/Ritonavir (RTV), LPV/r

LPV blocks a postentry step in the MERS‐CoV replication cycle, conferring this drug a promising potential agent for COVID-19 [ 70]. RTV blocks CYP3A-mediated metabolism of LPV thereby prolonging its exposure. LPV is metabolized primarily through CYP3A and transported by ABCB1 and ABCB2. RTV is metabolized by CYP2J2, CYP3A4, CYP3A5 and CYP2D6. RTV inhibits CYP3A and organic anion transporting polypeptides (OATP1B1 and OATP1B3), and may also induce other CYP isoforms [ 71]. RTV is enhancing the effect and concentrations of the medicines usually metabolized by CYP3A4, including LPV. RTV also increases the biotransformation of some drugs metabolized by glucuronidation catalyzed by UGT. The clinical relevance of these effects needs to be investigated. LPV/r was used in a regimen of 400 mg/100 mg bid for adults for 10-21 days [ 72]. There is also an initiative to reformulate LPV/r in a new extracellular vesicles delivery system [ 73].

Genetic screening of Apo lipoprotein E (APOE) and APOC3 can reduce the risk of hypertriglyceridemia and lipodystrophy associated with RTV [ 74]. Interindividual variations of LPV concentration were associated with SLCO1B1. A pharmacogenomic analysis of LPV/RTV, including 1380 variants in 638 HIV-infected Caucasians, identified four significant variants. Clearance of LPV was higher in individuals with SLCO1B1*4/*4 and lower in individuals with two or more variant alleles of SLCO1B1*5, ABCC2 or a CYP3A [ 75]. The CYP3A4 polymorphism L292P (rs28371759, CYP*18B) is linked with increased CYP3A4 activity, thus facilitating the metabolism of drugs like LPV. L292P was reported to occur more in East Asians, indicating that East Asians may metabolize LPV and RTV more rapidly. There are about 66 coding SNPs in ABCB1 gene [ 76]. The 3435 C > T is present in exon 26 of the ABCB1 gene, involving a C-to-T transformation, and does not alter the amino acid isoleucine. The variant allele frequency of 3435 C > T in the Asian population differs significantly from the African and Caucasian population [ 77]. There are many non-synonymous polymorphisms in ABCB1 [ 78]. Among them, S893T, S893A (rs2032582), N21D (rs9282564) and S400N (rs2229109) can increase the drug concentration through decreasing the efflux of ABCB1. S893A carriers are found in all populations with high frequency, which is up to 90% in Africans. S893T carriers are almost East Asians, while N21D carriers are Europeans. These patients may have more response to the drugs transported by ABCB1.

Atazanavir (ATV)

ATV exhibits potent anti-HIV activity and good oral bioavailability. ATV inhibits SARS‐CoV2 replication in both Vero cells and human epithelial pulmonary cells (A549). ATV is metabolized by CYP3A and is an inhibitor of CYP3A and UGT1A. The CPIC guideline for ATV considers several polymorphisms in UGT1A1, including a variable dinucleotide (TA) repeat within the gene promoter region (rs8175347, alleles UGT1A1*28, *36 and *37), and the SNPs rs4148323 ( UGT1A1*6) and rs887829 ( UGT1A1*80) [ 79]. The UGT1A1*28 allele predisposes to severe hyperbilirubinemia in individuals exposed to ATV [ 80]. UGT1A1*28 homozygotes have the highest risk and UGT1A1*28 heterozygotes have an intermediate risk of developing hyperbilirubinemia [ 81]. The CPIC guidelines for pharmacogenomic prescribing of ATV recommend counseling on the likelihood of developing hyperbilirubinemia in UGT1A1*28/*28,*28/*37, *37/*37, and −364 TT genotype carriers before initiating therapy [ 79]. ATV metabolism is partially due to the P-gp efflux pump encoded by the multidrug resistance 1 ( MDR1) gene, which seems to increase plasma concentrations of ATV in the presence of 3435 variable genetic homozygosis C/C, exposing the patient to a risk of hyperbilirubinemia and severe jaundice. Polymorphism 238 G > A appears to be related to an early onset of lipodystrophy [ 82]. Several studies demonstrated that APOA5 gene polymorphisms (1131 T > C and 64 G > C), APOC3 (482 C > T, 455 C > T, 3238 C > G), and ABCA1 (2962 A > G) and APOE (ε2 and ε3 haplotypes) are associated with a high risk of dyslipidemia [ 83].

Non-nucleoside reverse transcriptase inhibitors (NNRTIs)

Favipiravir (FVP)

FVP is a purine nucleic acid analog and potent RdRp) inhibitor. It has been shown to be effective in the treatment of influenza and Ebola virus disease [ 84]. FAV inhibits SARS‐CoV‐2 replication in Vero E6 cells [ 85]. FVP undergoes metabolism in the liver mainly by aldehyde oxidase and partially by xanthine oxidase. The efficacy of substrates of aldehyde oxidase such as azathioprine or allopurinol are associated with variants of aldehyde oxidase [ 86].

Nevirapine (NVP)

NVP is a NNRTI widely prescribed for HIV treatment. It is generally effective with some reported cases of hepatotoxicity and severe cutaneous adverse reactions. The HLA-DRB1*01, HLA-B*3505 and CYP2B6 gene polymorphisms have been associated with the onset of rash from NVP [ 87]. The CYP2B6 983 C allele was reported to confer a higher risk of SJS and TEN in a population of Mozambique treated with NVP. Polymorphism C > T position 3435 of MDR1 was associated with reduced risk of hepatotoxicity [ 88]. Also, the ABCC10 (MDR7) polymorphism rs2125739 has been associated with plasma concentrations of NVP.

Efavirenz (EFV)

EFV is predominantly inactivated by CYP2B6, and patients with certain CYP2B6 genetic variants may be at increased risk for adverse effects [ 89]. In a genome-wide association study, CYP2B6 rs4803419 (g.15582 C > T) was independently associated with increased plasma EFV exposure [ 90]. Patients who were homozygous for the minor allele (g.15582 T/T) had plasma EFV concentrations comparable to CYP2B6 intermediate metabolizers (based on CYP2B6 c.516 G > T and c.983 T > C status). CYP2B6 genotyping can possibly afford minimization of adverse effects with EFV, such as depression and suicidal tendencies, by tailoring the drug dose to the genotype of patients [ 91].

Oseltamivir

Oseltamivir targets the neuraminidase distributed on the surface of the influenza virus [ 92]. Several clinical trials are still evaluating the effectiveness of oseltamivir in treating SARS-CoV-2 infection [ 93]. Oseltamivir needs to be activated by carboxylesterase 1 (CES1) into its active metabolite, oseltamivir carboxylate [ 94]. G143E variants were reported to be 3.7%, 4.3%, 2.0% and 0% in White, Black, Hispanic and Asian populations, respectively [ 95]. A clinical study showed that G143E heterozygotes exhibited 18% greater AUC of oseltamivir and 23% smaller AUC ratios of oseltamivir carboxylate to oseltamivir compared to individuals with the 143GG genotype [ 96]. Significant inter-individual variability in oseltamivir PK and in antiviral effects have been consistently reported in clinical studies [ 97]. CES1 and ABCB1 genetic variants have the potential to serve as valid biomarkers for the prediction of oseltamivir activation and the optimization of oseltamivir pharmacotherapy [ 98].

Remdesivir

Preliminary clinical trials demonstrated remdesivir effectiveness for the treatment of COVID-19 [ 70]. Remdesivir is primarily metabolized by hydrolase in vivo [ 99]. It has a generally low risk of significant genetic PKs interactions. In vitro studies suggest that it is a substrate for drug metabolizing enzymes CYP2C8, CYP2D6, and CYP3A4, as well as a substrate for OATP1B1 and P-gp transporters [ 100]. Thus, known variants of these genes could theoretically affect the PKs of remdesivir. According to current knowledge, no guideline recommends pharmacogenetic testing before remdesivir administration.

Biological Drugs

Anakinra

Anakinra is a biologic medicine used in the treatment of rheumatoid arthritis (RA) in combination with methotrexate. Anakinra inhibits the IL-1α and IL-1β and has been used with some success in several small studies in patients with COVID-19 [ 101]. A relationship between the infrequent IL-1a + 4845 G/T polymorphism and a significant better response to anakinra treatment was reported [ 102].

Tocilizumab (TCZ)

Treatment with TCZ may reduce the risk of invasive mechanical ventilation or death in patients with severe COVID-19 pneumonia [ 103]. In vitro studies in hepatocytes have shown that TCZ blocks the downregulation of CYP450 (mainly CYP3A4) that is caused by IL6 [ 104]. Several genetic biomarkers have been associated with the efficacy of TCZ in RA, including FCGR3A, IL6R, CD69, and GALNT18 [ 105]. The only genetic variants potentially involving TCZ's PKs are in the FCGR3A gene. In 87 patients with RA treated with TCZ, FCGR3A rs396991TT genotype showed higher response at 12 months. Polymorphisms of IL6R are considered to affect the intracellular signaling pathway of IL-6 receptor bound to TCZ [ 106]. In contrast, variants in CD69 and GALNT18 are thought to have limited direct effects on TCZ. Genetic variation in IL6R may aid in predicting TCZ therapy outcome in COVID-19 patients. To date, no pharmacogenetic testing is recommended for TCZ.

Eculizumab

Multiple therapeutic agents targeting complement activation are currently being studied for COVID-19 [ 107] Eculizumab is a monoclonal antibody that specifically binds to C5 with high affinity, thereby inhibiting its cleavage to C5a and C5b and preventing the generation of the terminal complement complex C5b-9. AMY-101, a C3 inhibitor, is currently being tested in patients with COVID-19 [ 108]. The combination of clinical indicators of lung injury progression with known biomarkers of inflammation (C- reactive protein, plasma IL-6 levels and ferritin) would allow identification of patients that could benefit from complement inhibition [ 109].

Heme Oxygenase 1 (HO-1) up-regulators

Human HO protein has an important anti-inflammatory role in attenuating serious conditions like thrombosis, sepsis, tissue damage and fibrinogenesis, all of which are associated with SARS-CoV-2 infections [ 110]. The inducibility of HO-1 is regulated by the promoter region guanosine thymidine dinucleotide (GT)n repeats mutation [ 111]. Patients with COVID-19 complications have longer GT sequences [ 112]. Inducing HO-1 expression may prevent SARS-CoV-2-induced pulmonary complications [ 113].

Hemin, a substrate for HO-1 obtained from the breakdown of RBCs, is FDA approved for treatment of porphyria and is effective in blocking Zika viral replication [ 114]. The hemin-induced HO-1 cytoprotective pathway appears as a consistent target to control COVID-19. Heme arginate increases HO-1 levels by inhibiting delta-aminolevulinate synthase and so it can improve inflammation and viral infections [ 115]. Heme arginate is able to induce CYP2D6 and CYP3A4 [ 116]. CQ, HCQ, azithromycin, and remdesivir decrease heme production, in part, by inhibiting CYP induction, thus decreasing the demand for heme. These drugs also display interactions with the CYP system, which make maintaining safe effective therapeutic drug levels a challenge. Up-regulation of HO-1 is especially important in COVID-19 patients with the longer GT allele HO-1 polymorphism, and those with CYP2D6 polymorphisms that lead to supra- or sub-therapeutic drug levels. A synergistic anti-inflammatory effect may be obtained by the combination of heme arginate with repurposed anti-COVID-19 drugs that are not metabolized by CYP2D6/3A4. Recently, the glucocorticoid dexamethasone was found to save many severely ill COVID-19 patients [ 117]. Dexamethasone reduces hemolysis and induces HO-1 in macrophages [ 118], leading to attenuation of the severity of disease in COVID-19 patients. There are a number of naturally occurring substances that are capable of upregulating HO-1 [ 119] such as thymoquinone, neem leaf extract, resveratrol and curcumin.

Inhibitors of the renin-angiotensin-aldosterone system (RAAS)

There are some pharmacogenetic predictors of disposition and response of RAAS inhibitors [ 120]. Losartan, an ACE receptor blocker and is metabolized by CYP2C9 [ 121]. Genotyping some of Cyp 2C9 polymorphisms may affect losartan clinical benefits. The most common reduced-function variants are CYP2C9*2 (Arg144Cys), and CYP2C9*3 (Ile359Leu). CYP2C9 genotyping could be beneficial for dose adjustment. Other pharmacogenetic biomarkers, namely ABCB1 gene variants, could be useful predictors of losartan response [ 122]. The most relevant polymorphisms in ABCB1 are C3435T (rs1045642), G2677T/A (rs2032582) and C1236T (rs1128503) [ 123]. Regarding ACE inhibitors, ACE rs1799752 was related to variability in ACE inhibitors [ 124, 125]. This polymorphism consists of a 50-nucleotide deletion (del). Patients with the del/del diplotype correlated with a worse clinical outcome. The best pharmacogenetic predictor for spironolactone effectiveness is rs4961, located in the alpha-adducin gene, which predicts drug response in combination with furosemide [ 126]. Carriers of the G allele exhibited a better response to therapy compared with T allele carriers.

Anthelmintics

Ivermectin

Ivermectin has the potential to prevent viral replication of a broad spectrum of viruses. It has shown inhibition against SARS-CoV-2 in vitro through inhibition of Importin α/β1 (IMPα/β1)-mediated nuclear import of viral proteins [ 127]. Ivermectin is metabolized by CYP3A4. Ivermectin is both a substrate and a potent inducer of the P-gp. P-gp inhibitors can increase ivermectin plasma levels [ 128].

Nitazoxanide

Nitazoxanide and its active metabolite, tizoxanide have demonstrated potent activity against SARS CoV-2 and MERS CoV in Vero E6 cells. Nitazoxanide upregulates the innate antiviral mechanisms by broadly amplifying cytoplasmic RNA sensing and type I IFN pathways [ 85]. Metabolism of nitazoxanide occurs via hydrolysis and then conjugation via glucuronidation. Nitazoxanide has a very favorable drug interaction profile with no known clinically significant drug interaction concerns. So far, no pharmacogenetic studies regarding efficacy or toxicity of nitazoxanide were rported.

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Pharmacogenomics and COVID-19: clinical implications of human genome interactions with repurposed drugs

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The outbreak of Coronavirus disease 2019 (COVID-19) has evolved into an emergent global pandemic. Many drugs without established efficacy are being used to treat COVID-19 patients either as an offlabel/compassionate use or as a clinical trial. Although drug repurposing is an attractive approach with reduced time and cost, there is a need to make predictions on success before the start of therapy.

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Oi pessoal, trouxe esse artigo que fala um pouco sobre o progresso do desenvolvimento e aplicação de anticorpos terapêuticos contra COVID-19, falando sobre os problemas e desafios correspondentes e ainda sugerindo novas estratégias e soluções. #anticorpos

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Oi pessoal, trouxe esse artigo que fala um pouco sobre o progresso do desenvolvimento e aplicação de anticorpos terapêuticos contra COVID-19, falando sobre os problemas e desafios correspondentes e ainda sugerindo novas estratégias e soluções. #anticorpos

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Affiliations

¹ School of Healthcare Technology, Chengdu Neusoft University, Sichuan, China.

² School of Life Science and Technology, University of Electronic Science and Technology of China, Sichuan, China.

³ Center for Informational Biology, University of Electronic Science and Technology of China, Sichuan, China.

Free PMC article

Free PMC article

Affiliations

¹ School of Healthcare Technology, Chengdu Neusoft University, Sichuan, China.

² School of Life Science and Technology, University of Electronic Science and Technology of China, Sichuan, China.

³ Center for Informational Biology, University of Electronic Science and Technology of China, Sichuan, China.

Abstract

The pandemic of Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome 2 coronavirus (SARS-CoV-2) continues to be a global health crisis. Fundamental studies at genome, transcriptome, proteome, and interactome levels have revealed many viral and host targets for therapeutic interventions. Hundreds of antibodies for treating COVID-19 have been developed at preclinical and clinical stages in the format of polyclonal antibodies, monoclonal antibodies, and cocktail antibodies. Four products, i.e., convalescent plasma, bamlanivimab, REGN-Cov2, and the cocktail of bamlanivimab and etesevimab have been authorized by the U.S. Food and Drug Administration (FDA) for emergency use. Hundreds of relevant clinical trials are ongoing worldwide. Therapeutic antibody therapies have been a very active and crucial part of COVID-19 treatment. In this review, we focus on the progress of therapeutic COVID-19 antibody development and application, discuss corresponding problems and challenges, suggesting new strategies and solutions.

Keywords: COVID-19; SARS-CoV-2; antibody cocktail; convalescent plasma; monoclonal antibody; therapeutic antibody.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interest exists.

References

Zhou P, Yang X Lou, Wang XG, Hu B, Zhang L, Zhang W. et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020;579(7798):270-3. - PMC - PubMed

Wu F, Zhao S, Yu B, Chen YM, Wang W, Song ZG. et al. A new coronavirus associated with human respiratory disease in China. Nature. 2020;579(7798):265-9. - PMC - PubMed

Harrison AG, Lin T, Wang P. Mechanisms of SARS-CoV-2 Transmission and Pathogenesis. Trends Immunol. 2020;41(12):1100-15. - PMC - PubMed

Bedford J, Enria D, Giesecke J, Heymann DL, Ihekweazu C, Kobinger G. et al. COVID-19: towards controlling of a pandemic. Lancet. 2020;395(10229):1015-8. - PMC - PubMed

WHO. WHO Coronavirus Disease (COVID-19) Dashboard [Internet] Available from: https://covid19.who.int.

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national center for biotechnology information

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Development and application of therapeutic antibodies against COVID-19 - PubMed

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The pandemic of Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome 2 coronavirus (SARS-CoV-2) continues to be a global health crisis. Fundamental studies at genome, transcriptome, proteome, and interactome levels have revealed many viral and host targets for therapeu ...

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Boa tarde gente, ainda sobre a ultima aula sobre produtos naturais, encontrei esse artigo de 2019 sobre saúde ambiental, os autores fazem uma revisão bibliográfica sobre os produtos naturais e suas ações sobre doenças como a Leishmaniose 

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Boa tarde gente, ainda sobre a ultima aula sobre produtos naturais, encontrei esse artigo de 2019 sobre saúde ambiental, os autores fazem uma revisão bibliográfica sobre os produtos naturais e suas ações sobre doenças como a Leishmaniose 

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#produtosnaturais

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Oie gente, trouxe um artigo babado publicado em 2014 na Revista Saúde e Ciência sobre anticorpos monoclonais, em que é debatido a posição deles enquanto opção terapêutica na oncologia.

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Oie gente, trouxe um artigo babado publicado em 2014 na Revista Saúde e Ciência sobre anticorpos monoclonais, em que é debatido a posição deles enquanto opção terapêutica na oncologia.

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#anticorpos

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Descoberta de medicamentos por meio da inteligência artificial #drugdiscovery

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Descoberta de medicamentos por meio da inteligência artificial #drugdiscovery

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Olá pessoal! Encontrei este artigo muito interessante, de 2019, que aborda sobre os avanços na descoberta de medicamentos através da inteligência artificial. Como o custo para a descoberta de medicamentos torna-se alto, além de ser um processo por vezes complexo e longo, espera-se que a inteligência artificial atrelada à novas tecnologias experimentais, torne a busca por novos produtos farmacêuticos mais rápida, barata e eficaz.

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Uma forma lúdica de aprender sobre desenvolvimento de medicamentos #drugdiscovery

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Uma forma lúdica de aprender sobre desenvolvimento de medicamentos #drugdiscovery

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Oi gente! Hoje gostaria de compartilhar com vocês esse artigo que trata da criação de um jogo para facilitar o aprendizado sobre o Desenvolvimento e Descoberta de novas Drogas (DDD) para alunos de pós-graduação, principalmente, de farmacologia, química medicinal, toxicologia, entre outros. Achei esse artigo bem interessante pela nova perspectiva de ensino desse tema que é bastante importante, principalmente por ser uma forma lúdica de capacitar futuros profissionais nessa área de atuação. #drugdiscovery

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SCREENER, an educational game for teaching the Drug Discovery and Development process

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Although the use of games as an educational strategy is an important current trend, there is...

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Farmacogenômica no Tratamento de Sarcomas de Tecidos Moles. #farmacogenomica

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Farmacogenômica no Tratamento de Sarcomas de Tecidos Moles. #farmacogenomica

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Oi gente, gostaria de compartilhar esse artigo que trata das novas perspectivas da farmacogênomica no tratamento de sarcomas de tecidos moles, considerando a otimização da eficácia e a redução dos efeitos de toxicidade. Achei esse artigo interessante por tratar da medicina personalizada numa doença altamente variável como o câncer. Espero que gostem. #farmacogenomica

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Highlights

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Clinical response to therapies is limited to a small subset of soft tissue sarcoma (STS) patients.

*

Genetic polymorphisms may influence drug response and toxicities.

*

Pharmacogenomic markers are located in drug metabolizing enzymes and transporters.

*

Single-nucleotide polymorphisms are suitable biomarkers for toxicity and drug response.

Abstract

Clinical responses to anticancer therapies in advanced soft tissue sarcoma (STS) are unfortunately limited to a small subset of patients. Much of the inter-individual variability in treatment efficacy and risk of toxicities is as result of polymorphisms in genes encoding proteins involved in drug pharmacokinetics and pharmacodynamics. Therefore, the detection of pharmacogenomics (PGx) biomarkers that might predict drug response and toxicity can be useful to explain the genetic basis for the differences in treatment efficacy and toxicity among STS patients. PGx markers are frequently located in transporters, drug-metabolizing enzyme genes, drug targets, or HLA alleles. Along this line, genetic variability harbouring in the germline genome of the patients can influence systemic pharmacokinetics and pharmacodynamics of the treatments, acting as predictive biomarkers for drug-induced toxicity and treatment efficacy. By linking drug activity to the functional complexity of cancer genomes, also systematic pharmacogenomic profiling in cancer cell lines and primary STS samples represents area of active investigation that could eventually lead to enhanced efficacy and offer a powerful biomarker discovery platform to optimize current treatments and improve the knowledge about the individual's drug response in STS patients into the clinical practice.

Keywords

Single-nucleotide polymorphisms

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Pharmacogenomics of soft tissue sarcomas: New horizons to understand efficacy and toxicity

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Clinical response to therapies is limited to a small subset of soft tissue sarcoma (STS) patients. * Genetic polymorphisms may influence drug response and toxicities. * Pharmacogenomic markers are located in drug metabolizing enzymes and transporters. * Single-nucleotide polymorphisms are suitable biomarkers for toxicity and drug response.

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Estudos farmacogenômicos em larga escala e predição de resposta a medicamentos para medicina personalizada do câncer #farmacogenômica

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Estudos farmacogenômicos em larga escala e predição de resposta a medicamentos para medicina personalizada do câncer #farmacogenômica

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Olá! Nesta revisão, os autores discutem sobre como a farmacogenômica tem evoluído nos últimos 20 anos, tendo produzido vários biomarcadores e estudos complexos dentro da área, providenciando insights sobre novas formas de tratamento de câncer, dentro da medicina personalizada. Além disso, o estudo cita os recentes métodos computacionais para predição de resposta à drogas, bem como os desafios existentes dentro da medicina personalizada voltada para o tratamento de câncer.

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A startup brasileira InsilicAll integra Inteligência Artificial, Computação e Automação Biológica para aumentar a taxa de sucesso em levar medicamentos inovadores para as necessidades dos pacientes, diminuindo o cronograma, os custos e o tempo para que um novo produto chegue à sociedade, visando superar os principais desafios de #drugdiscovery. Nesse vídeo, Rodolpho Braga, CTO da empresa, fala sobre como ocorreu o processo de identificação de oportunidade no mercado brasileiro e os serviços oferecidos pela empresa científica.

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VIDEO #163 - A TRANSFORMAÇÃO DIGITAL NA PESQUISA -  INSILICALL, UMA STARTUP BIOTECH

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The reaction oncology platform: programa integrado de drug discovery direcionado ao câncer #Drug Discovery 

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The reaction oncology platform: programa integrado de drug discovery direcionado ao câncer #Drug Discovery 

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Olá a todos gostaria de indicar que conheça  o reaction oncology platform que é um serviço de suporte a pesquisa e desenvolvimento de moléculas ativas contra o câncer, tal iniciativa foi realizada pela empresa reaction biology e tem como objetivo fornecer uma parceria com consultoria e suporte aplicado a pesquisadores ou empresas que visam desenvolver tais moléculas ou medicamentos no futuro. Assim, o serviço oferece suporte as etapas do processo de drug discovery com: target research, hit identificantion, hit-to-lead, lead otimization e ensaios pré-clínicos. Logo, forncecendo análises preditivas precisas, determinação de biomarcadores, ensaior aplicados, entre outros serviços por meio dos laboratórios parceiros. É interessante conhecer tais iniciativas, visto a grande possibilidade de desenvolvimento de medicamentos eficientes no tratamento de câncer, assim como conhecer um pouco mais a fundo as etapas do processo. Encaminho o link do portfólio que apresenta a plataforma para ser acessada. #Drug Discovery

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Reaction Oncology Platform | Reaction Biology

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Helping patients with effective treatments they urgently need, is what we live for. Our employees are passionate to accelerate drug discovery process in finding responses to our clients' most pressing questions.

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Dissertação: Produtos Naturais na Descoberta de Fármacos    #DrugDiscovery

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Dissertação: Produtos Naturais na Descoberta de Fármacos    #DrugDiscovery

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A autora dessa dissertação de mestrado de 2018 traz uma revisão bibliográfica do uso de produtos naturais, os principais métodos utilizados e sua evolução na descoberta de fármacos.
Muito bom, vale a pena dar uma olhada!

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Utilize este identificador para referenciar este registo: http://hdl.handle.net/10284/6660

Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.

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Produtos naturais na descoberta de fármacos

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Utilize este identificador para referenciar este registo: http://hdl.handle.net/10284/6660 Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.

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Dockthor: servidor brasileiro para screening de drogas                                                                          #drugdiscovery

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Dockthor: servidor brasileiro para screening de drogas                                                                          #drugdiscovery

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Olá, pessoal, boa noite. Trago pra vocês esse site brasileiro, do LNCC, que realiza docking online de proteína com seu ligante, podendo ser, no caso, as famosas "small drug molecules". Todos já sabem como é importante a triagem de hits, e o dockthor pode auxiliar de grande forma, avaliando por meio de docking, a interação da proteína com os hits.

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Attention: DockThor is temporarily unavailable for maintenance. Sorry for the inconvenience.

COVID-19: We provide to the DockThor users structures of COVID-19 potential targets already prepared for docking at the Protein tab. New targets and structures will be available soon.

Guedes, I. A. et al. Drug design and repurposing with DockThor-VS web server focusing on SARS-CoV-2 therapeutic targets and their non-synonym variants. Sci Rep 11, 5543 (2021).

A Free Web Server for Protein-ligand Docking

Interactive Analyses. Explore docking poses and predict affinity.

Investigate different binding modes and predict binding affinities. Visualize predicted complexes with JSMol.

SDumont Supercomputer. Virtual screening experiments even faster.

Run virtual screening experiments at Santos Dumont supercomputer, located at LNCC, Petrópolis - Brazil.

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Attention: DockThor is temporarily unavailable for maintenance. Sorry for the inconvenience. COVID-19: We provide to the DockThor users structures of COVID-19 potential targets already prepared for docking at the Protein tab. New targets and structures will be available soon. Guedes, I. A. et al.

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Notícia: farmacogenômica em evidência                                                          #farmacogenômica

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Notícia: farmacogenômica em evidência                                                          #farmacogenômica

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Olá, pessoal, boa noite. Trago essa notícia que traz um certo resumo de como é o cenário da farmacogenômica, mas também traz o dado de que houve um aumento significativo na procura de exames de farmacogenética de uma empresa no ano passado, em comparação ao mesmo período do ano antepassado. Isso serve de evidência de como essa área está tendo um crescimento surpreendente.

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Por Andressa Paladino, Isabella Maria Dias Payão Ortiz, Maíra Cícero Ferreira e Pamella Silveira Sulai

Por que uma pessoa responde melhor a um determinado tratamento medicamentoso do que outra? A resposta pode estar no genoma humano. A medicina tem entre suas vertentes a medicina personalizada, ganhando principal destaque a farmacogenética, que estuda como as diferenças genéticas influenciam as respostas aos . O objetivo dessa área da medicina é entender de forma mais rápida, precisa e segura qual o melhor tratamento para cada paciente, impedindo o agravamento das enfermidades e garantindo longevidade e uma melhor qualidade de vida.

Apenas no DB Molecular, no primeiro semestre de 2021, foi computado um aumento de mais de 400% na procura por exames de farmacogenética, quando comparado ao mesmo período do ano passado. Boa parte dessas solicitações tinha como objetivo auxiliar o médico na prescrição de uma terapia medicamentosa mais eficaz e com menos efeitos colaterais, principalmente para tratamento de doenças, como depressão, psicose, ansiedade e epilepsia.

Essa grande variação de respostas aos medicamentos se dá por múltiplos fatores, como a adesão terapêutica, o estágio da doença, a presença de doenças sistêmicas, a dieta realizada pelo paciente e a própria variação genética do indivíduo. Isso porque cada indivíduo tem pequenas variações que são próprias do seu DNA, conhecidas como polimorfismos. Essas modificações ocorrem nas enzimas associadas à metabolização dos fármacos, influenciando assim a velocidade em que esse medicamento é processado pelo organismo, desde o momento em que é administrado até, por fim, ser eliminado. Se o medicamento for processado muito rapidamente, ele pode não desempenhar o efeito desejado no organismo. Por outro lado, se demorar muito para ser metabolizado, podem ocorrer os efeitos colaterais.

Para descobrir a velocidade de metabolização de cada fármaco, é realizada uma simples coleta de sangue, que identifica as variações presentes nos genes que podem interferir nas respostas aos remédios.

É preciso destacar que existem dois grupos de genes responsáveis pela ação do medicamento. O primeiro grupo é constituído pelos genes que influenciam na forma como o organismo modifica o fármaco. O segundo consiste nos genes que influenciam a maneira como o medicamento modifica nosso organismo.

Essa melhor seleção de medicamentos, com base nas informações genéticas, pode significar menores efeitos colaterais e melhores resultados ao tratamento. Com isso, há benefícios para os pacientes, mas também para o serviço de saúde, já que o indivíduo não precisará retornar ao médico com tanta frequência para trocar os medicamentos.

Diante desse cenário, a farmacogenética pode auxiliar no tratamento de doenças crônicas, como câncer, Alzheimer, Parkinson e depressão, identificando polimorfismos associados com a eficácia e os efeitos colaterais dos medicamentos, que geram diferentes respostas ao tratamento para cada grupo de indivíduos.

Com isso, podemos concluir que exames farmacogenéticos são necessários para todos aqueles que passam por tratamentos prolongados e/ou intensivos e que precisam de um acompanhamento médico mais próximo. Esses são exames que podem gerar um grande ganho na qualidade de vida do paciente.
*Andressa Paladino, Isabella Maria Dias Payão Ortiz, Maíra Cícero Ferreira, Pamella Silveira Sulai são Especialistas de Produtos do DB Molecular.

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A importância dos exames genéticos para direcionamento de tratamentos medicinais

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Por Andressa Paladino, Isabella Maria Dias Payão Ortiz, Maíra Cícero Ferreira e Pamella Silveira Sulai Por que uma pessoa responde melhor a um determinado tratamento medicamentoso do que outra? A resposta pode estar no genoma humano. A medicina tem entre suas vertentes a medicina personalizada, ganhando principal destaque a farmacogenética, que estuda como as diferenças [...]

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Boa tarde pessoal! Hoje trouxe para vocês essa revisão de 2018 que aborda sobre o progresso recente do uso da farmacogenômica em medicamentos antipsicóticos. A farmacogenômica da resposta a drogas antipsicóticas é uma área ativa de pesquisa atualmente. Neste estudo, são abordadas descobertas recentes na pesquisa epigenética, incluindo a metilação do DNA, a qual promete novas descobertas que potencialmente podem ser aplicadas na prática clínica.

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Apresentando Insichem: Um projeto brasisleiro de plataformas de drug discovery #drugdiscovery

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Apresentando Insichem: Um projeto brasisleiro de plataformas de drug discovery #drugdiscovery

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Boa tarde a todos os colegas. Recomendo a todos que explorem e analisem o site da Insichem, empresa start-up especializada em tecnologia computacional para Drug Discovery atuante no Brasil. No site podemos encontrar publicações vinculadas à companhia, explicações sobre o procedimento de drug discovery em si e a apresentação dos projetos da empresa, como softwares de modelagem e de avaliação e testagem de pequenas moléculas druglike.

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Nos dias 04 e 05 de setembro na cidade de São Paulo, a InSiChem Drug Discovery com o apoio do Programa de Incubadoras de Empresas da Universidade Estadual de Goiás (PROIN.UEG), participou do BIO Latin Conference organizado pela Fundação Biominas Brasil. Esta...

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Nos dias 04 e 05 de setembro na cidade de São Paulo, a InSiChem Drug Discovery com o apoio do Programa de Incubadoras de Empresas da Universidade Estadual de Goiás (PROIN.UEG), participou do BIO Latin Conference organizado pela Fundação Biominas Brasil. Esta...

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Farmacogenômica no Brasil: A diversidade genética dos brasileiros #farmacogenômica

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Farmacogenômica no Brasil: A diversidade genética dos brasileiros #farmacogenômica

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Boa tarde a todos. Segue um breve artigo da SciELO contextualizando a farmacogenômica há mais de uma década, apontando sua importância e seu potencial. Fica o destaque para a abordagem do Refargen, projeto que evoluiu cada vez mais ao longo dos anos e se tornou referência para os cientistas brasileiros. Também é interessante avaliar a enorme evolução da farmacogenômica de 2009 pra cá.

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EDITORIAL

Farmacogenômica e a diversidade genética da população brasileira

A população brasileira é uma das mais heterogêneas do mundo, em conseqüência de cinco séculos de miscigenação entre três raízes ancestrais: os ameríndios autóctones, os europeus e os africanos subsaarianos. Essa heterogeneidade e miscigenação têm implicações importantes no desenho e interpretação de ensaios clínicos farmacogenéticos, na implementação dos princípios de farmacogenética/farmacogenômica (FGx), na prescrição de medicamentos e, ainda, em relação à extrapolação de dados farmacogenéticos obtidos em outras populações. O paradigma populacional em FGx emerge da observação de que a freqüência de inúmeros polimorfismos em "farmacogenes" varia amplamente entre as populações. Um exemplo extremo disso ocorre no gene CYP3A5 que codifica a enzima CYP3A5, importante via de eliminação de diversos medicamentos de uso clínico, tais como os imunossupressores tacrolimus e ciclosporina. A freqüência do alelo variante CYP3A5*3, que codifica uma isoforma inativa de CYP3A5, é < 10% entre as populações subsaarianas e > 90% entre europeus. No entanto, a freqüência do alelo CYP3A5*3 em brasileiros sadios vivendo no Rio de Janeiro e que se autoclassificaram como brancos ou pretos (conforme o critério oficial do censo brasileiro) foi de 78% e 32%, respectivamente ( Pharmacogenomics 2007; 8:1299-306). Ou seja, o alelo CYP3A5*3 é três vezes mais freqüente entre brasileiros autodeclarados pretos (32%) do que nos africanos (< 10%), e ocorre com menor freqüência em brasileiros autodeclarados brancos (78%) do que nos europeus (> 95%). A miscigenação de nossa população pode explicar essas discrepâncias, pois, independentemente da autodeclaração por "cor/raça" (na terminologia do censo brasileiro), a maioria dos brasileiros tem ancestralidade européia e africana, às quais se soma, em um número significativo de indivíduos, a ancestralidade ameríndia ( Pharmacogenomics in Admixed Populations. Landes Bioscience; 2007). É razoável pensar que a contribuição da ancestralidade européia nos indivíduos autodeclarados pretos explique a maior freqüência do alelo CYP3A5*3 neste grupo, em relação aos africanos; da mesma forma, a presença de ancestralidade africana explicaria a menor freqüência de CYP3A5*3 nos autodeclarados brancos, comparados aos europeus. A situação exemplificada pelo alelo CYP3A5*3 foi observada com outros polimorfismos farmacogenéticos estudados por nosso grupo ( Pharmacogenet Genomics 2007; 17:765-72; Eur J Clin Pharmacol 2008; 3:253-6). Esse conjunto de dados indica que é claramente inapropriada a extrapolação de dados farmacogenéticos obtidos em grupos relativamente homogêneos (europeus, norte-americanos brancos ou africanos subsaarianos) para a população brasileira, heterogênea e miscigenada ( Trends Pharmacol Sci 2005; 26:196-201).

O reconhecimento desse fato motivou a criação da Rede Nacional de Farmacogenética (REFARGEN; http://www.refargen.org.br), um consórcio de 18 grupos de pesquisadores de diferentes instituições brasileiras, com a missão de promover a pesquisa e a educação em FGx no Brasil, com impacto na saúde da população. Em estudos recentes, os pesquisadores da REFARGEN empregaram métodos de regressão logística para investigar a influência da ancestralidade genética individual - estimada por meio de polimorfismos de inserção/deleção, validados como marcadores de ancestralidade ( Ann Human Genet 2006; 70:658-65) - na distribuição de freqüência de polimorfismos farmacogenéticos em brasileiros. Os resultados indicam que a miscigenação de nossa população deve ser tratada como uma variável contínua que não é adequadamente representada pela distribuição dos indivíduos em categorias arbitrárias de "raça/cor". No contexto da prescrição medicamentosa, isso implica que cada paciente deve ser tratado como um indivíduo e não como um "exemplar de uma raça", e que a noção de medicamentos "raça"-específicos é inaceitável, especialmente no caso de populações miscigenadas.

Guilherme Suarez-Kurtz

Rede Nacional de Farmacogenética / Instituto Nacional de Câncer, Rio de Janeiro, Brasil.

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Farmacogenômica e a diversidade genética da população brasileira

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EDITORIAL Farmacogenômica e a diversidade genética da população brasileira A população brasileira é uma das mais heterogêneas do mundo, em conseqüência de cinco séculos de miscigenação entre três raízes ancestrais: os ameríndios autóctones, os europeus e os africanos subsaarianos.

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Potencial antitumoral em plantas brasileiras #drugdiscovery

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Potencial antitumoral em plantas brasileiras #drugdiscovery

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Como vimos na aula sobre Produtos Naturais e Drug Discovery, existe uma infinidade de moléculas na natureza que possuem ações farmacológicas e podem ser utilizadas para formulação de medicamentos.

Hoje eu trouxe uma notícia do INCA (Instituto Nacional de Câncer) que mostra como pesquisadores da USP vem explorando o potencial medicinal de plantas brasileiras com capacidade antitumoral. Os extratos dessas plantas já demonstraram alta capacidade de inibição de linhagens tumorais de câncer de pulmão e mama e leucemia, podendo ser úteis no desenvolvimento de novos fármacos.

#drugdiscovery

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Potencial antitumoral das plantas brasileiras

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Esse artigo de revisão publicado em 2009 fala sobre  o desenvolvimento da farmacogenômica na Psiquiatria. assim como debate perspectivas futuras entre estas.
#farmacogenomica

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O medicamento certo para você #farmacogenômica

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O medicamento certo para você #farmacogenômica

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Oi, pessoal! Compartilhando com vocês esse artigo bem curtinho (mas muito interessante) da Nature. O autor mostra, com alguns exemplos reais, como conhecer o genoma de um paciente impacta os resultados de um tratamento.

Esse artigo foi publicado em uma seção da revista direcionada à Medicina de Precisão, que une técnicas já convencionalmente utilizadas na medicina à análise do perfil genético de um indivíduo (deixo aqui também um vídeo do FDA que fala um pouco mais sobre o assunto - What is Precision Medicine? - YouTube).

Espero que gostem! #farmacogênomica

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Olá a todos, gostaria de indicar a leitura do seguinte artigo de revisão que integra a abordagem de farmacogenômica com o estudo diagnóstico e tratamento de doenças cardiovasculares. Os autores abordam aspectos ligados ao metabolismo assim como fica destacado a importância da farmacogenômica no para o tratamento em momentos mais apropriados ou de forma mais efetiva para cada paciente. Além disso, são exemplificados os principais fármacos explorados pelas pesquisas recentes, assim como fica demonstrado certos entraves na implantação das técnicas de farmacogenômica, demonstrando que ainda existem perspectivas interessantes para o futuro. #Farmacogenômica

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A farmacogenômica (FGx) investiga a interação entre genes e medicamentos. Através da análise de regiões específicas do DNA, informações sobre o perfil de metabolização do paciente para um determinado fármaco podem ser descritas, assim como o perfil esperado de resposta ao tratamento. Objetivamente, esse tipo de teste pode ter impacto no tratamento de pacientes que não estão respondendo adequadamente a um determinado medicamento, seja pela ausência dos efeitos esperados ou em virtude do aparecimento de efeitos adversos. Neste cenário, o objetivo desta revisão é o de informar o cardiologista clínico sobre esta importante área do conhecimento e atualizá-lo sobre o tema, procurando preencher as lacunas no que diz respeito à relação custo-benefício da aplicação da FGx nas doenças cardiovasculares, além de fornecer informações para a implementação da terapia guiada pela FGx na prática clínica.

Palavras-chave
Doenças Cardiovasculares; Genes; Hereditariedade; Genoma; Perfil Genético; Farmacogenética; Biotransformação; Tratamento Farmacológico/eventos adversos; Saúde Pública

A farmacogenômica (FGx) é a ciência que estuda a interação entre genes e medicamentos. A partir da análise de regiões específicas do DNA, é possível obter informações sobre, por exemplo, o perfil de metabolização do paciente para um determinado fármaco, bem como o perfil esperado de resposta ao tratamento. A FGx também visa diminuir a ocorrência de eventos adversos aos medicamentos (EAM)., As inúmeras pesquisas nesta área têm focado na identificação de genes que predispõem às doenças, modulam respostas aos fármacos, e afetam a concentração e a ação desses medicamentos, além de se associarem a reações adversas. É frustrante saber que a eficácia de alguns tratamentos medicamentosos varia entre 25% a 80%, sendo que somente um terço dos pacientes expostos ao uso de diferentes tipos de fármacos obtém os benefícios terapêuticos desejados.

A ocorrência de EAM constitui um problema de saúde pública no mundo todo, pois aumenta significativamente o tempo de hospitalização, além de ter sido considerada como a quarta dentre as seis causas mais frequentes de morte nos Estados Unidos nos últimos 20 anos., Lá, por exemplo, mais de dois milhões de pessoas são hospitalizadas e pelo menos 55.000 morrem por ano em decorrência da não resposta ao tratamento ou de EAM. No Brasil, os dados ainda são escassos, e a FGx pode ser uma ferramenta de auxílio tanto no tratamento do paciente quanto na otimização dos gastos financeiros. Foi evidenciado que no Hospital de Clínicas de Porto Alegre, Brasil, 14% dos pacientes procuraram a emergência por EAM, e as classes de medicamentos mais envolvidas foram os antirretrovirais, os anticoagulantes, e os anti-hipertensivos. Daqueles que procuraram a emergência uma primeira vez, 20-30% retornaram. Os pesquisadores evidenciaram que o custo médio para tratar um paciente por EAM durante um ano foi de R$ 2200,00, sendo o custo total de 18 milhões de reais.

A doença cardiovascular (DCV) é a principal causa de morte no mundo, contribuindo significativamente para o crescente ônus econômico na área da saúde. Em 2016, 31% de todas as mortes no mundo (17,9 milhões) foram causadas por DCVs; aproximadamente 555 bilhões de dólares foram gastos nos Estados Unidos, e as previsões informam que esses custos aumentem para US$ 1,1 trilhão no ano 2035.

Sabemos que existem várias classes de medicamentos para reduzir o risco de DCV, como também existe uma variação significativa na resposta ao tratamento. Além da variação que pode ser atribuída a diversas características sociodemográficas, há determinantes genéticos da droga, assim como respostas que podem afetar a maneira como as drogas são metabolizadas, absorvidas e distribuídas.14. Johnson JA, Cavallari LH. Pharmacogenetics and cardiovascular disease--implications for personalized medicine. Pharmacol Rev. 2013;65(3):987-1009. 17. Lee MS, Flammer AJ, Lerman LO, Lerman A. Personalized medicine in cardiovascular diseases. Korean Circ J. 2012;42(9):583-91. ,¹⁴
¹⁷

18. Joyner MJ. Precision medicine, cardiovascular disease and hunting elephants. Prog Cardiovasc Dis. 2016;58(6):651-60.
15. Peters BJM, Klungel OH, de Boer A, Ch Stricker BH, Maitland-van der Zee AH. Pharmacogenetics of cardiovascular drug therapy. Clin Cases Miner Bone Metab. 2009;6(1):55-65. ⁻ Portanto, dados genéticos podem ser usados para identificação e avaliação das respostas a doses de drogas, controle de efeitos colaterais e também para previsão de resultados.⁻ Nos últimos anos, devido ao desenvolvimento na clonagem de genes, na genotipagem e no sequenciamento de DNA, a FGx emerge como um componente útil. O conhecimento atual pode ser aplicado em um gene individual, em uma área terapêutica ou em medicamento específico: a) uso de testes FGx para prever a dose individual de medicamento; b) uso de testes FGx para prever a ausência de resposta a um medicamento; e c) uso de testes FGx para prever indivíduos com sério risco de toxicidade se um medicamento for prescrito ou administrado.

Várias diretrizes clínicas nessa área do conhecimento estão disponíveis, sendo as principais delas: o Clinical Pharmacogenetics Implementation Consortium (CPIC), o Dutch Pharmacogenetics Working Group (DPWG), o Canadian Pharmacogenomics Network for Drug Safety (CPNDS), o Groupe de Pharmacologie Clinique Oncologique (GPCO/Unicancer), o Réseau National de Pharmacogénétique Hospitalière (RNPGx), e o American College of Rheumatology (ACR).

Um Pouco de História

Umas das primeiras terapias baseadas em uma mutação específica, que mudaram significativamente o prognóstico de doenças, são o trastuzumab no câncer de mama HER-2 positivo e o imatinibe na leucemia mieloide crônica., Desde então, a oncologia aposta progressivamente na utilização da informação genética, e atualmente esta serve para pautar a decisão terapêutica, tendo incluído o teste genômico em 39% dos ensaios clínicos de oncologia em 2018. Além da oncologia, inúmeras outras áreas identificaram ou aprimoraram tratamentos baseados em variações genéticas. Para a fibrose cística já foram identificadas mais de 100 mutações causadoras, o que, apesar de dificultar o desenvolvimento de tratamento específico para cada variante, possibilitou o agrupamento dos seus subtipos que parecem responder a tratamentos semelhantes.

Os avanços da medicina genômica não se limitam apenas a drogas que agem a nível proteico. Técnicas como o CRISPR ( clustered regularly interspaced short palindromic repeats) - uma região especializada do DNA - são usadas para silenciar genes e evitar o desenvolvimento de doenças em embriões e/ou modificar genes relacionados à doença em adultos. Essas técnicas são parte do que se conhece como terapia genética e, apesar de estarem em fase embrionária, são esperadas como alternativas potencialmente revolucionárias.

Metabolização de Medicamentos

* Metabolizadores Lentos

* Metabolizadores intermediários

* Metabolizadores rápidos

* Metabolizadores ultrarrápidos

O gene CYP2D6, especificamente, é responsável pelo metabolismo em cerca de 25% dos medicamentos prescritos, e possui alelos que podem causar os quatro tipos de metabolismo descritos anteriormente. Estes alelos têm uma prevalência que varia de acordo com a etnia. Por exemplo, um dos principais alelos não funcionais conhecidos, o CYP2D6*4, tem prevalência estimada de 25% em indivíduos caucasianos; já o alelo CYP2D6*10 e CYP2D6*17 (ambos de função reduzida) são mais comuns em africanos e asiáticos, com uma frequência alélica de aproximadamente 40%.

Ensaios Clínicos Randomizados

Diversos estudos vêm sendo realizados nos últimos anos para testar o papel da FGx na prática clínica. Em um ensaio clínico randomizado (ECR), 1.956 pacientes infectados pelo vírus da imunodeficiência humana (HIV) foram divididos em dois grupos. O primeiro foi rastreado prospectivamente quanto à presença do alelo HLA-B*5701 e, aqueles positivos, não receberam o antiviral abacavir. O outro grupo recebeu tratamento padrão com abacavir sem rastreamento prospectivo quanto à presença de HLA-B*5701 (grupo controle). A incidência de hipersensibilidade ao medicamento foi menor no grupo que passou pelo rastreamento genético (3,4%) em comparação ao grupo controle (7,8%). Este resultado levou a Food and Drug Administration (FDA) dos Estados Unidos a incluir a exigência do teste FGx na bula do medicamento. Mais recentemente, o estudo de Smith et al. evidenciou redução de 30% na intensidade de dor em usuários crônicos de opioide quando a terapia era guiada pela presença da variante no gene CYP2D6. Uma meta-análise, incluindo cinco ECRs, encontrou 1,71 mais chance de remissão de sintomas em pacientes recebendo terapia guiada por genotipagem quando comparada à terapia usual.

Focando na área de DCVs, os estudos mais numerosos são relacionados aos antiagregantes plaquetários e aos anticoagulantes. Após observações retrospectivas de que a presença de variantes genéticas classificadas como perda de função apresentava impacto nos efeitos do clopidogrel, iniciativas surgiram para avaliar o benefício de incluir o teste de forma rotineira. Investigadores da Implementing Genomics in Practice (IGNITE) evidenciaram em um grupo de 1.815 pacientes, maior taxa de eventos cardiovasculares naqueles com variantes de perda de função do gene CYP2C19 e em uso de clopidogrel, comparado com antiplaquetários alternativos, como o prasugrel ou o ticagrelor (hazard ratio [HR] 2,26, intervalo de confiança [IC] 95% 1,18-4,32; p=0,013). Outro ECR mostrou diminuição importante nos eventos coronarianos tardios com a implementação da estratégia FGx para uso do clopidogrel.

Já em relação à varfarina, a maioria dos estudos avaliou variantes genéticas ligadas ao seu metabolismo nos genes CYP2C9 e VKORC1. O European Pharmacogenetics of anticoagulant therapy (EU-PACT) mostrou que, guiando a terapia pelo teste genético, houve aumento significativo no tempo em que os pacientes mantinham-se com um INR ( International Normalized Ratio) dentro da faixa terapêutica (2,0-3,0). Mais recentemente, o estudo Genetics Informatics Trial of Warfarin to Prevent Deep Vein Thrombosis (GIFT) mostrou diminuição de sangramentos significativos, tromboembolismo venoso e morte no período perioperatório em pacientes com terapia guiada por FGx para cirurgias eletivas de implante de próteses de quadril e de joelho. Ambos os estudos citados relacionados à varfarina incluíram uma população majoritariamente branca e, por isso, há a necessidade de se incluir variantes do CYP2C9 mais comuns em populações de ascendência africana para obtenção de resultados mais acurados relacionados a esse grupo populacional. Por sua vez, o maior dos estudos da varfarina, o Clarification of Optimal Anticoagulation Through Genetics (COAG) mostrou-se diferente dos demais e relatou não haver diferença em se iniciar terapia com varfarina guiada por informação clínica ou guiada pela pesquisa de variantes do gene CYP2C9, as quais são muito mais comuns em população de ascendência europeia, em uma coorte composta apenas por 27% de afro-americanos. Por outro lado, e considerando o custo-benefício relacionado ao uso da varfarina e do clopidogrel, uma revisão sistemática recente que incluiu 31 ECRs mostrou que, comparado à terapia padrão, o teste FGx foi superior em 81% das vezes.

Paralelamente aos estudos de medicamentos isolados, o conceito de teste preventivo vem crescendo e apresentando algumas evidências de benefício. Em 2012, Schildcrout et al. mostraram, em uma coorte de 52.942 pacientes em cuidado domiciliar, uma exposição de 64,8% a pelo menos um medicamento de mecanismo influenciado por variantes genéticas. Os autores estimaram em 398 o número de eventos adversos potenciais que poderiam ter sido evitados com a genotipagem preventiva. Já o estudo do genótipo de 44.000 participantes do biobanco da Estônia mostrou que 99,8% desses indivíduos tinham genótipo associado a um risco aumentado a pelo menos uma medicação. Com resultados concordantes, o protocolo RIGHT ( 'Right Drug, Right Dose, Right Tim eUsing Genomic Data to Individualize Treatment') criado pela clínica Mayo/iniciativa eMERGE, sequenciou painel incluindo os genes SLCO1B1 (membro da família do transportador de ânions orgânicos transportadores de soluto 1B1), CYP2C19, CYP2C9, VKORC1 e CYP2D6. Eles identificaram em 99% dos 1.013 indivíduos pelo menos uma variante de risco para uso de algum medicamento.

Nos Estados Unidos, medicamentos com recomendações relacionadas à FGx perfazem 18% de todas as prescrições e 30% dos medicamentos com alto risco FGx mais prescritos representam 738 milhões de prescrições por ano. Tais informações vão à direção de que parece existir um impacto positivo do teste FGx preventivo, não apenas pelo aumento da eficácia terapêutica e custo-benefício, mas também pelo seu potencial de evitar EAMs. Além dos dados já mencionados, um estudo holandês também mostrou benefício pela redução de 73% para 28% no risco de na taxa de intoxicação por fluoropirimidinas em pacientes com dose guiada por genotipagem, além da redução das mortes induzidas pelo medicamento de 10% para 0%.

Importância da Farmacogenômica

Diferentes são os benefícios que podem ser alcançados com o advento da FGx, a citar:

Além disso, a FGx pode contribuir para redução geral no custo dos cuidados de saúde, conforme apresentado na Figura 1. É importante mencionar que quase 200 mil mortes/ano na Europa são relacionadas aos EAM, com um custo de aproximadamente 80 bilhões de euros.

Estima-se que uma boa parcela dos pacientes não apresenta respostas consideradas satisfatórias aos medicamentos., Nesse sentido, a FDA recomenda, por exemplo, que testes FGx sejam realizados antes da quimioterapia com a droga mercaptopurina - utilizada comumente para pacientes com alguns tipos de leucemia aguda. Tal recomendação baseia-se no fato de que, como esta droga pode causar efeitos colaterais graves e aumentar o risco de infecção a depender da variante genética do indivíduo, a terapia pode não surtir o efeito desejado.

O Genomics and Targeted Therapy Group, um braço do departamento de Farmacologia Clínica da FDA, tem como objetivo garantir a aplicação apropriada das estratégias FGx por meio das suas funções de revisão regulatória, pesquisa, desenvolvimento de diretrizes e educação profissional. Parte desse trabalho incluiu a criação de uma tabela agrupando as orientações farmacológicas das 161 drogas, que até o momento contém informações genômicas em seus rótulos. Sua última atualização traz números expressivos de biomarcadores associados a drogas em diversas áreas da medicina, inúmeras delas amplamente utilizadas na prática clínica ( Tabela 1).

Por fim, espera-se que, em breve, a FGx seja mais acessível e que a sua utilização consciente possa contribuir para que os médicos prescrevam as medicações com maior "acurácia" e os pacientes possam recebê-las com maior chance de sucesso terapêutico aliado ao menor risco de EAM.

Associação entre Variantes Genéticas e Respostas aos Medicamentos na Doença Cardiovascular

É de amplo conhecimento que fatores como idade, comorbidades, peso, bem como aqueles demográficos, podem contribuir para diferenças significativas nas respostas a uma mesma terapia farmacológica, bem como ao desenvolvimento de EAM., Nesse contexto, a variação genética pode representar um pilar fundamental para esse desfecho. Acredita-se que muitas mortes ao redor do mundo poderiam ter sido evitadas se o médico tivesse conhecimento prévio do perfil FGx dos pacientes, e pudesse empregar a medicação em doses corretas para aquele indivíduo. Pacientes com um mesmo diagnóstico (por exemplo, infarto agudo do miocárdio) são normalmente tratados da mesma maneira, embora suas respostas à terapia medicamentosa possam ser distintas. A "terapia sob medida" pode reduzir os EAMs e aumentar as taxas de eficácia, conforme ilustrado na Figura 2. Por exemplo, há uma enorme variação na dose diária necessária de um dos anticoagulantes mais utilizados na prática clínica, a varfarina, podendo variar em até 20 vezes. Por sua vez, o propranolol (betabloqueador) pode ter a sua dose variando em até 40 vezes a depender de qual paciente esteja recebendo a droga. Alguns fármacos utilizados em larga escala na prática clínica do cardiologista, os quais podem ter importantes associações genéticas, são apresentados na Tabela 2.

Varfarina

A varfarina é um fármaco pertencente à classe dos antagonistas da vitamina K, e vem sendo utilizada em grande escala na prevenção de eventos trombóticos. Evidências sugerem que a resposta do indivíduo à varfarina, bem como a outros antagonistas da vitamina K, pode ser influenciada de forma importante por variações genéticas na enzima hepática do citocromo P450 (CYP2C9) e na Subunidade 1 do complexo Epóxido Redutase da Vitamina K (VKORC1), alvo para estes fármacos,, além de polimorfismos no membro 2 da subfamília F e família 4 do citocromo P450 4 (CYP4F2). Foi demonstrado que variações nos alelos CYP2C9*2 e CYP2C9*3 diminuíram a atividade enzimática da CYP2C9 e inibiram o metabolismo anticoagulante, enquanto o polimorfismo VKORC1- 1639G>A parece ter influência na resposta farmacodinâmica aos antagonistas da vitamina K. Devido a essas observações, a FDA apontou a necessidade de informações FGx na bula da varfarina.

Na prática, os portadores heterozigotos dos alelos de função reduzida CYP2C9*2 ou CYP2C9*3 podem necessitar de uma dose reduzida de varfarina em cerca de 30% e 47%, respectivamente, enquanto os portadores homozigotos CYP2C9*3 podem necessitar reduções ainda maiores (~80%).69. Sconce EA, Khan TI, Wynne HA, Avery P, Monkhouse L, King BP, et al. The impact of CYP2C9 and VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements: proposal for a new dosing regimen. Blood. 2005;106(7):2329-e33. ⁶⁹

70. Higashi MK, Veenstra DL, Kondo LM, Wittkowsky AK, Srinouanprachanh SL, Farin FM, et al. Association between CYP2C9 genetic variants and anticoagulation-related outcomes during warfarin therapy. JAMA. 2002;287(13):1690e8. ⁻ Por sua vez, a variante -1639 G>A do gene VKORC1 parece reduzir a expressão de proteínas, o que teoricamente representa uma dose menor de manutenção de varfarina em comparação com os não portadores desta variante. Da mesma forma, combinações de algumas variantes associadas a um metabolismo extremo tornam mais difícil a obtenção de um INR terapêutico de maneira sistemática nesses pacientes. Nesse cenário, as diretrizes do CPIC recomendam considerar um anticoagulante oral de ação direta (por exemplo, edoxabana).

Clopidogrel

Nos Estados Unidos, estima-se que mais de três milhões de indivíduos recebam anualmente prescrição de clopidogrel após a colocação de um stent. Ele é um fármaco tienopiridínico do grupo dos antiagregantes plaquetários. A resposta do indivíduo frente ao clopidogrel pode sofrer alteração, determinada pelo polimorfismo do CYP2C19.

A variante de perda de função do CYP2C19*2 foi associada a um risco aumentado de eventos cardiovasculares adversos, incluindo trombose de stent durante o tratamento com clopidogrel. Mais especificamente, o alelo CYP2C19*2 (rs4244285) causa perda de função e foi associado à redução na atividade antiagregante do medicamento. Além disso, portadores do alelo CYP2C19 *3 (rs4986893) também têm respostas reduzidas ao clopidogrel e uma taxa mais alta de eventos cardiovasculares adversos recorrentes em comparação com não portadores., É importante mencionar que as frequências dos alelos CYP2C19 *2 e CYP2C19 *3 são mais altas nas populações asiáticas, sugerindo que estes indivíduos têm maior probabilidade de serem resistentes à terapia com esta droga. Em contraste, o alelo CYP2C19*17 (rs3758581) promove ganho de função e tem sido associado ao aumento da atividade enzimática e à melhor inibição das plaquetas. Os portadores da variante CYP2C19*17 foram denominados metabolizadores ultrarrápidos.

A raça parece ser outro fator com papel importante nesse cenário. Cresci et al. compararam o efeito do polimorfismo do CYP2C19 sobre eventos CVs adversos entre pacientes com infarto agudo do miocárdio em caucasianos e afro-americanos tratados com clopidogrel. Foi observado que o alelo CYP2C19*2 teve associação significativa com aumento da taxa de mortalidade em um ano e a uma tendência no aumento na incidência de infarto do miocárdio recorrente em caucasianos. Já o alelo CYP2C19*17 foi associado a um aumento na mortalidade em um ano e a um risco aumentado de sangramento em afro-americanos. É importante mencionar que pacientes submetidos à intervenção coronária percutânea que possuem pelo menos um alelo CYP2C19*2 podem apresentar maior risco de trombose de stent. Em um ECR, aproximadamente 2.500 pacientes foram pré-tratados uniformemente com 600 mg de clopidogrel. Os portadores do alelo CYP2C19*2 apresentaram um aumento significativamente maior na incidência de trombose de stent em 30 dias, quando comparados com os portadores do alelo CYP2C19 de tipo selvagem. Nessa mesma linha, a meta-análise conduzida por Mega et al., que arrolou estudos com pacientes mais complexos e em tratamento agressivo, encontrou um risco aumentado de trombose de stent quando o alelo *2 foi identificado pela FGx.

Na atualidade, o American College of Cardiology em conjunto com a American Heart Association também não recomenda testes de FGx de rotina para o CYP2C19. No entanto, outra meta-análise mais recente demonstrou que os pacientes que se beneficiam do estudo FGx são aqueles com doença arterial coronária que são submetidos a procedimentos de revascularização miocárdica percutânea. Nesse contexto, o CPIC recomenda formalmente que pacientes com síndrome coronária aguda, ou ainda, aqueles submetidos à intervenção coronária percutânea, sejam submetidos ao teste FGx. O CPIC enfatiza que aqueles que possuem uma ou duas cópias do alelo com perda de função devem receber agentes antiplaquetários alternativos (como prasugrel ou ticagrelor), a fim de reduzir o risco de eventos cardiovasculares adversos. Por outro lado, outras populações de pacientes (por exemplo, fibrilação atrial), nas quais o uso do clopidogrel é mais discutível, o painel FGx não está indicado.

Recentemente, os resultados do ECR TAILOR PCI foram apresentados. Este estudo avaliou uma estratégia guiada por genótipo (n = 2.652) versus terapia padrão (n = 2.650) em pacientes com doença arterial coronariana estável ou instável submetidos à intervenção coronária percutânea com objetivo de orientar a terapia antiplaquetária. No grupo randomizado para estratégia guiada por genótipo, os pacientes submetidos à genotipagem receberam ticagrelor 90 mg duas vezes ao dia (portadores de um alelo CYP2C19 *2 ou *3) ou clopidogrel 75 mg diariamente. No grupo denominado terapia padrão, os sujeitos receberam 75 mg de clopidogrel diariamente e passaram por genotipagem somente após 12 meses. O desfecho primário era composto por morte cardiovascular, infarto do miocárdio, acidente vascular cerebral, trombose de stent ou isquemia recorrente em 12 meses. O desfecho primário e a incidência de sangramento não foram diferentes entre os grupos de tratamento. Entretanto, cabe ressaltar a redução de 34% nesses eventos em um ano, bem como uma redução significativa de 40% no número total de eventos por paciente no braço guiado por FGx. Por fim, uma análise post hoc encontrou uma redução de aproximadamente 80% na taxa de eventos adversos nos primeiros três meses de tratamento nos pacientes randomizados para terapia guiada por genótipo.,

Betabloqueadores

Essa classe de drogas é amplamente utilizada para o tratamento de arritmias cardíacas, angina, infarto do miocárdio e hipertensão. Os genes associados à resposta inter individual do betabloqueador incluem o CYP2D6, o adrenoceptor beta 1 (ADBR1), o adrenoceptor beta 2 (ADBR2) e o receptor quinase 5 acoplado à proteína G (GRK5). Por exemplo, alguns betabloqueadores, incluindo propranolol e o metoprolol, são metabolizados pelo CYP2D6, e a perda de função desta variante é muito comum. Por sua vez, evidências sugeriram que pacientes hipertensos portadores do alelo Arg389 tipo selvagem homozigoto obtiveram três vezes maior redução da pressão arterial diastólica diurna com o uso do metoprolol quando comparados aos portadores do alelo Gly389. Embora com resultados ainda não tão consistentes, pacientes que são homozigotos do haplótipo Arg389 do ADBR1 parecem apresentar uma resposta mais satisfatória a toda a família dos betabloqueadores, apresentando melhor fração de ejeção do ventrículo esquerdo quando comparados aos portadores do alelo Gly389.

Assim, no cenário da insuficiência cardíaca, ainda não há recomendações para o uso de informações FGx que visem orientar o uso de betabloqueadores.

Estatinas

Possíveis Barreiras à Implementação da Farmacogenômica

Graças ao avanço da tecnologia e das técnicas de sequenciamento, o custo da avaliação FGx diminuiu significativamente nos últimos anos (Lei de Moore), facilitando seu uso na prática clínica; porém, o custo relativamente elevado ainda representa uma barreira para a implementação mais ampla dessa ferramenta. Além disso, uma possível falta de familiaridade dos profissionais da saúde, a ausência de uma plataforma padronizando a investigação e o pensamento acadêmico e, de uma forma geral, o fato de que o volume de estudos que demonstram os benefícios da FGx ainda é insuficiente, são fatores que contribuem para uma baixa aceitação por parte da comunidade científica da inclusão de testes FGx na prática clínica.

No entanto, esforços para contornar esses obstáculos ocorrem atualmente de forma global e contam com estudos de grandes proporções, tais como, o UK's 100.000 Genomes Project e o PREemptive Pharmacogenomic testing for prevention of Adverse drug REactions (PREPARE), o qual conta com a participação de sete países na Europa. No outro lado do Atlântico Norte, nos Estados Unidos, o Electronic Medical Records and Genomics (eMERGE), o Network and the Implementation of Genomics in Practice (IGNITE), e o Clinical Sequencing Evidence Generating Research Consortium, são parte de uma série de projetos custeados pelo National Human Genome Research Institute, sendo estimado um investimento na pesquisa genética de pelo menos US$ 775 milhões no período de 2007-2022. Na Ásia, o programa South East Asian Pharmacogenomics Research Network (SEAPharm) inclui cinco países para conduzir estudos de FGx. De forma geral, estes estudos visam definir, gerar e analisar evidências sobre a utilidade clínica do sequenciamento genômico para guiar terapia, custo-eficácia e o valor de sua implementação de forma vasta na prática médica. Dos resultados já obtidos, uma revisão que incluiu 44 avaliações de custo-benefício, mostrou que 30% delas mostrou custo-efetividade e 27% evidenciou até redução de custos, o que contribui para uma perspectiva otimista para o futuro da FGx.

Entre inúmeras contribuições das iniciativas globais para a expansão da FGx na prática clínica, vale destacar um de seus aspectos cruciais: a educação e o treinamento dos profissionais de saúde e a promoção e estímulo ao investimento em tecnologia nos centros de pesquisa e assistência. Além da contribuição com a literatura, os projetos promovem o treinamento de pessoas para a prática adequada da medicina genômica, a qual exige a adoção de atitudes básicas que talvez sejam menos relevantes em outras especialidades. Exemplos são a inclusão da família do paciente no aconselhamento e no plano de tratamento, além da confidencialidade que assegura o uso de informações genéticas com propósitos exclusivamente assistenciais (evitando seu uso inapropriado para imposição da lei, seguros, marketing ou relação empregatícia). A educação e treinamento têm papel central para a aceitação da medicina genômica na prática clínica, e a aceitação por sua vez é ponto chave para sua implementação. O esforço para geração de dados contribui significativamente, mas a disposição e engajamento dos profissionais da área da saúde que almejam a excelência da assistência médica são indispensáveis. A dimensão e o progresso dos esforços e investimentos que ocorrem globalmente deixam clara a relevância e o potencial atribuídos à medicina genômica, que já pode ser considerada parte da prática médica de alta qualidade e um dos pilares da medicina de precisão.

1. 1)
Áreas de consenso: o teste FGx pode ser útil para o uso otimizado de diversos medicamentos, permitindo uma maior segurança farmacológica;

2. 2)
Áreas de controvérsia: se os testes FGx devem ser aplicados mais amplamente, inclusive na prescrição de certos medicamentos em que o benefício geral é menos claro, permanece controverso;

3. 3)
Área de crescimento: cada vez mais, as informações pessoais sobre genótipos são disponibilizadas diretamente ao consumidor. Isso provavelmente aumentará a demanda por prescrição personalizada, significando que os prescritores precisam levar em consideração as informações FGx. Como exemplo, podemos citar o Projeto 100.000 genomas. Este impressionante projeto fornecerá sequências genômicas completas que podem fazer parte de um prontuário médico do paciente. Esta informação parece ser de grande valor na prescrição personalizada;

4. 4)
Áreas oportunas para o desenvolvimento de pesquisas: desenvolvimento de novos medicamentos visando fatores de risco genéticos específicos para doenças. Estes podem ser prescritos para aqueles com genótipo de risco. É provável que as informações FGx estejam disponíveis rotineiramente no futuro, especialmente em ambientes tecnologicamente avançados. Isso poderia influenciar a prescrição de uma variedade de medicamentos além daqueles para os quais, atualmente, são necessários testes antes da prescrição.

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Sibbing D, Stegherr J, Latz W, Koch W, Mehilli J, Dorrler K, et al. Cytochrome P450 2C19 loss-of-function polymorphism and stent thrombosis following percutaneous coronary intervention. Eur Heart J. 2009;30(8):916-22.

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Mega JL, Simon T, Collet JP, Anderson JL, Antman EM, Bliden K, et al. Reduced-function CYP2C19 genotype and risk of adverse clinical outcomes among patients treated with clopidogrel predominantly for PCI: a meta-analysis. JAMA. 2010;304(16):1821-30.

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Sorich MJ, Rowland A, McKinnon RA, Wiese MD. CYP2C19 genotype has a greater effect on adverse cardiovascular outcomes following percutaneous coronary intervention and in Asian populations treated with clopidogrel: a meta-analysis. Circ Cardiovasc Genet. 2014;7(6):895-902.

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Claassens DMF, Vos GJA, Bergmeijer TO, Hermanides RS, van 't Hof AWJ, van der Harst P, et al. A Genotype-Guided Strategy for Oral P2Y12 Inhibitors in Primary PCI. N Engl J Med. 2019;381(17):1621-31.

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Farmacogenômica e Doença Cardiovascular: Onde Estamos e Para Onde Vamos

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A farmacogenômica (FGx) investiga a interação entre genes e medicamentos. Através da análise de regiões específicas do DNA, informações sobre o perfil de metabolização do paciente para um determinado fármaco podem ser descritas, assim como o perfil esperado de resposta ao tratamento.

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Teste da GeneOne avalia a eficácia de medicamentos para cada paciente   #Farmacogenômica

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Teste da GeneOne avalia a eficácia de medicamentos para cada paciente   #Farmacogenômica

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Essa matéria do Portal de Atualização em Medicina do Brasil, de março de 2021, fala sobre o novo teste da GeneOne, laboratório de medicina genômica da Dasa. Esse teste analisa o DNA do paciente e fornece um panorama completo de como os medicamentos com informações farmacogenômicas aprovados pelo FDA agem no organismo do indivíduo. Achei muito interessante e parecido com o exemplo que o professor mostrou na aula.
Vale a pena conferir e comparar!

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O campo dos testes farmacogenéticos foi aclamado como uma das primeiras aplicações clínicas bem-sucedidas decorrentes da revolução da medicina de precisão. Este progresso substancial foi realizado para identificar genes e variantes genéticas envolvidas na resposta a medicamentos e estabelecer programas de implementação clínica. Agora imagine um painel dinâmico que avalia uma importante parte do metabolismo do seu paciente e que demonstra, com precisão, como os medicamentos vão reagir ao organismo dele, sua eficácia, a interação com outros fármacos, com alimentos e até com os hábitos de vida do mesmo.
Leia também: Mais de 50 medicamentos atualizados no Whitebook
Diferenciais do novo teste

É desta forma individualizada que o novo teste da GeneOne, laboratório de medicina genômica da Dasa, apresenta o seu laudo interativo. O exame analisa o DNA do paciente e fornece ao especialista um panorama completo, que indica como algumas rotinas da vida e remédios de uso contínuo agem no organismo.

Dessa forma, medicamentos que não têm indicadores tangíveis, como os psiquiátricos podem ser ajustados, trocados ou retirados com maior rapidez do tratamento por estarem causando reações indesejadas.

"Este teste possibilita que médicos e pacientes possam prever, antes mesmo de receitar ou comprar o medicamento, as chances de um resultado mais satisfatório, com mais respostas e menos efeitos colaterais", ressalta Leandro Brust, responsável técnico pela área de farmacogenômica da Dasa.

De acordo com dados da American Heart Association, alguns alimentos, inclusive os considerados saudáveis, também podem tornar as medicações menos eficientes. Aliás, não somente os remédios têm a capacidade de reagir entre si, mas práticas como o tabagismo, o álcool e o sedentarismo também influenciam a genética e a resposta do organismo.

Painel interativo e dinâmico

O painel apresenta uma relação de 103 medicamentos que já possuem uma informação farmacogenômica consolidada, todos eles aprovados pelo FDA, órgão regulador dos Estados Unidos, além de atividades e hábitos que podem ser escolhidos para compor o perfil.

O médico ou o próprio paciente pode fazer essa seleção e monitorar o painel, de forma segura e restrita, com login e senha. A nova tecnologia ainda permite que sejam incluídos dados de histórico de patologias e outros quadros, fixos ou temporários. O laudo é dinâmico e atemporal e a lista principal dos medicamentos vai aumentando ao longo do tempo.
Saiba mais: Os efeitos tóxicos de um histórico medicamentoso incompleto
O exame é realizado via coleta de sangue ou amostra de saliva em uma das quase 900 unidades de laboratórios da Dasa ou também via atendimento domiciliar. O prazo para o processamento do exame é de 40 dias úteis. E não há restrição de idade para fazer o exame, até por crianças que precisem de tratamentos com medicações.

"Normalmente, pessoas mais velhas tendem a tomar muitos remédios. Com o auxílio deste novo teste, podemos considerar um grande impacto positivo, inclusive no custo das hospitalizações, na produtividade das pessoas e, em última instância, até na rotina dessas famílias", destaca Gustavo Campana, diretor médico da Dasa.
*Esse artigo foi revisado pela equipe médica da PEBMED
Autor(a):
Referências bibliográficas:

DASA. Exames genéticos permitem conhecer melhor cada organismo e são a chave para uma medicina mais personalizada. É o que oferece a nossa marca, GeneOne. Disponível em: https://dasa.com.br/inovacao/genetica

Veja mais beneficios de ser usuário do Portal PEBMED: Veja mais beneficios de ser usuário
do Portal PEBMED:

# data[].attributes.attachment_link.title
Teste avalia a eficácia de medicamentos para cada paciente

# data[].attributes.attachment_link.description
O campo dos testes farmacogenéticos foi aclamado como uma das primeiras aplicações clínicas bem-sucedidas decorrentes da revolução da medicina de precisão. Este progresso substancial foi realizado para identificar genes e variantes genéticas envolvidas na resposta a medicamentos e estabelecer programas de implementação clínica.

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Olá, pessoal. Vimos na aula que a farmacogenômica tem como objetivo identificar variações genéticas entre indivíduos e populações, com o intuito de determinar protocolos de tratamento adequados para aumentar a eficácia de medicamentos e diminuir possíveis efeitos colaterais. Partindo disso, o artigo que trago hoje fornece uma visão geral de polimorfismos genéticos humanos relacionados com o mecanismo de infecção por SARS-CoV-2 e variações genéticas nos genes de enzimas metabolizadoras de medicamentos apontados para o tratamento da COVID-19.

#farmacogenomica

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Reviews in Medical Virology - 2020 - AL%u2010Eitan - Pharmacogenomics of genetic polymorphism within the genes responsible for

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Uso de inteligência artificial para a predição de novos anticorpos #anticorpos

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Uso de inteligência artificial para a predição de novos anticorpos #anticorpos

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Cientistas estão usando uma inteligência artificial que foi originalmente desenvolvida para a criação de vídeos e imagens "falsas" para o descobrimento de novos anticorpos que poderão ajudar a neutralizar doenças desconhecidas que ainda poderão aparecer no futuro.

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Scientists are using AI originally developed for producing deepfake videos to stop future pandemics

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Generative adversarial networks are being used to predict the structure of antibodies that could neutralize a previously unknown virus

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Anticorpos monoclonais e seus efeitos no tratamento de enxaqueca #anticorpos

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Anticorpos monoclonais e seus efeitos no tratamento de enxaqueca #anticorpos

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Olá, pessoal! Todo mundo já teve ou conhece alguém que já sentiu uma enxaqueca (também conhecida como migrânea), mas você sabia que existem fármacos que tratam esse problema? Pois é, quatro anticorpos monoclonais mostraram eficácia terapêutica e estão disponíveis no mercado para os indivíduos que enfrentam as cefaleias características da migrânea. Para saber mais é só ler o PDF disponível ;)

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Aplicações de anticorpos de IgY de galinhas para 🤬 imunodiagnósticos #anticorpos

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Aplicações de anticorpos de IgY de galinhas para 🤬 imunodiagnósticos #anticorpos

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https://www.scielo.br/j/cr/a/VV3zzbbkFgDBzphy7yzgrKk/?lang=en#

Os anticorpos têm várias aplicações médicas e científicas, sendo o anticorpo mamifero IgG altamente utilizado. Os anticorpos IgY podem ser considerados os análogos dos anticorpos IgG para aves. Esse artigo descreve várias caracteristicas dos anticorpos IgY e discorre sobre seus beneficios e aplicaçoes para 🤬 imunodiagnósticos, como por exemplo maior avidez, menor custo, e maior escalabilidade.

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Immunoglobulin Y (IgY) is the major antibody isotype in birds, reptiles, amphibia, and lungfish, playing a similar biological role as mammal IgG. Due to its phylogenetic distance, immune diversification and presence in the egg yolk, IgY provide a number of advantages in immunodiagnostic compared to IgG from mammals. Moreover, IgY production is in agreement with international efforts to reduce, refine and if possible, to replace animals in experimentation, contributing substantially in favor of animal welfare. This article presents an overview about structural and functional features, production and applications of IgY in immunodiagnostic, as well as the advantages of chicken antibodies use.

egg yolk antibody; immunodiagnostics; immunoglobulin Y; polyclonal antibodies

A imunoglobulina Y (IgY) é a classe de anticorpos de maior importância em aves, répteis, anfíbios e peixes pulmonados, desempenhando um papel semelhante a IgG de mamíferos. Devido a sua distância filogenética, mecanismos de diversificação imune e presença na gema do ovo, IgY proporciona uma série de vantagens em imunodiagnóstico, quando comparada a IgG de mamíferos. Além disso, esse método alternativo de produção de anticorpo está de acordo com os esforços internacionais para reduzir, refinar e, se possível, substituir animais em experimentação, contribuindo substancialmente a favor do bem-estar animal. Este artigo apresenta uma revisão sobre as características estruturais e funcionais da IgY, bem como os métodos de produção, vantagens e aplicações em imunodiagnóstico, além das vantagens da sua utilização.

anticorpo da gema do ovo; imunodiagnóstico; imunoglobulina Y; anticorpo policlonal

REVIEW

MICROBIOLOGY

Avian IgY antibodies: characteristics and applications in immunodiagnostic

Anticorpos IgY aviário: características e aplicações em imunodiagnóstico

Lívia Silveira MunhozI; Gilberto D'Ávila VargasI; Geferson FischerI; Marcelo de LimaI; Paulo Augusto EstevesII; Silvia de Oliveira HübnerI,

ILaboratório de Virologia e Imunologia Animal, Departamento de Veterinária Preventiva, Universidade Federal de Pelotas (UFPel), Campus Capão do Leão, 96010-900, CP 354, Pelotas, RS, Brasil. E-mail: sohubner@yahoo.com.br

II Grupo de Pesquisa em Sanidade de Aves, EMBRAPA Suínos e Aves, Vila Tamanduá, Concórdia, SC, Brasil

ABSTRACT

Immunoglobulin Y (IgY) is the major antibody isotype in birds, reptiles, amphibia, and lungfish, playing a similar biological role as mammal IgG. Due to its phylogenetic distance, immune diversification and presence in the egg yolk, IgY provide a number of advantages in immunodiagnostic compared to IgG from mammals. Moreover, IgY production is in agreement with international efforts to reduce, refine and if possible, to replace animals in experimentation, contributing substantially in favor of animal welfare. This article presents an overview about structural and functional features, production and applications of IgY in immunodiagnostic, as well as the advantages of chicken antibodies use.

Key words: egg yolk antibody, immunodiagnostics, immunoglobulin Y, polyclonal antibodies.

RESUMO

A imunoglobulina Y (IgY) é a classe de anticorpos de maior importância em aves, répteis, anfíbios e peixes pulmonados, desempenhando um papel semelhante a IgG de mamíferos. Devido a sua distância filogenética, mecanismos de diversificação imune e presença na gema do ovo, IgY proporciona uma série de vantagens em imunodiagnóstico, quando comparada a IgG de mamíferos. Além disso, esse método alternativo de produção de anticorpo está de acordo com os esforços internacionais para reduzir, refinar e, se possível, substituir animais em experimentação, contribuindo substancialmente a favor do bem-estar animal. Este artigo apresenta uma revisão sobre as características estruturais e funcionais da IgY, bem como os métodos de produção, vantagens e aplicações em imunodiagnóstico, além das vantagens da sua utilização.

Palavras-chave: anticorpo da gema do ovo, imunodiagnóstico, imunoglobulina Y, anticorpo policlonal.

INTRODUCTION

Immunoglobulins (glycoproteins also called antibody) are secreted by plasma cells in response to antigens exposure and consist in a major effector product of humoral immunity (TIZARD, 2002). These immunoglobulins are also widely used in the field of diagnostics and scientific research being employed either for detection or quantification of antibodies and specific antigens associated with various diseases by several techniques such as immunodiffusion, ELISA, and Western blotting. Historically, the animal species chosen for antibody production to be used for diagnostic purposes have been of mammalian origin. These antibodies are obtained from blood collected either by repeated bleeding or heart puncture which may frequently result in distress or even death of the animal. The production of IgY antibodies from immunized chicken eggs is an excellent alternative to the traditional methods. This review will describe the structural and functional characteristics of avian IgY, focusing on its potential as an important tool for immunodiagnosis.

The IgY

Immunoglobulin Y (IgY) is the major antibody in birds, reptiles, and lungfish (WARR et al., 1995). In birds, the IgY is found mainly in blood and in the fluid fraction of the egg providing protection to newly hatched chick (SCHADE et al., 2005). The antibodies transfer from serum to eggs was first demonstrated by KLEMPERER (1893), however this discovery remained for a long period with no scientific applications. When animal welfare became more relevant in scientific studies, researchers began to seek alternatives to reduce the indiscriminate use of animals for research and diagnostic purposes. Although IgY and IgG are sometimes used as synonyms in the scientific literature, the term IgY has become universally accepted based on its unique features (LESLIE & CLEM, 1969; SCHADE et al., 1996; TIZARD, 2002).

Structural and functional features of IgY

Like IgG, IgY contains two heavy and two light polypeptide chains, shaped in the Y characteristics and presents two binding sites for the antigen. IgY and IgG are eluted from diethylaminoethyl cellulose with low ionic strength buffers (WARR et al., 1995). However there are striking differences that must be considered: there is little or no immunological cross-reactivity between IgY and mammalian IgG. IgY has a higher molecular weight (~180kDa and ~160kDa to IgG) due to an extra constant domain in its heavy chain (H), lacks a well-defined hinge region and has an unique oligosaccharide in its structure. It has been proposed that the extra domain (CH2) may be the evolutionary precursor to the mammalian IgG hinge region (WARR et al., 1995). IgY is also capable of mediate anaphylactic reactions, a function attributed to IgE in mammals (CARLANDER, 2002). In fact, other similarities between IgY and IgE, including a similar intra chain disulphide bond in their extra heavy chain domain, lead to suggest that IgY is the ancestral molecule to both IgG and IgE, and molecular genetic studies have confirmed these findings (WARR et al., 1995). Fc region of IgY mediates most biological effector functions, such as complement fixation, anaphylactic reactions and opsonization, whereas the Fab region contains the antigen binding sites (DAVISON et al., 2008). The H chain (Mw 65,105kDa) of IgY, called upsilon (" υ" capital letter H) has one variable (V) and four constant (C) regions whereas the light chain (Mw 18,660kDa) is composed of one V and one C region. The light chain is lighter than its mammalian counterpart and has restricted mobility of the hinge region (Cυ2) (CARLANDER, 2002). IgY is stable at pH 4-9 and up to 65°C in aqueous condition. However, high salt conditions or the addition of stabilizing reagents increase its resistance to heat, acid extreme pH and high pressure (SHIMIZU et al., 1992).

It has been identified in some anseriform birds and reptiles the truncated form of IgY, with evolutionary origins still unknown (OTA et al., 2003). This truncated IgY have low molecular weight (~120kDa) and contain only two constant domains without two terminal domains of the heavy chain (TIZARD, 2002). This truncated isoform of IgY is produced as a result of alternative splicing of heavy chain messenger RNA, being called IgY (∆Fc). However, LI et al. (2012) have demonstrated that IgY and IgY(∆Fc) are codified in different genes in some species, like in the red-eared turtle. As the truncated isoform lacks a functional Fc region, it cannot undertake the usual immunoglobulin effector functions such as complement activation or Fc receptor binding (TIZARD, 2002). The immunoglobulin Y, full-sized and truncated, can be found in the same individual as in some ducks and geese, or only one form, like in Gallus domesticus where only the whole IgY is present (LIU & HIGGINS, 1990; KITAGUCHI et al., 2008).

Previous studies have shown the presence of three immunoglobulin classes in birds (IgA, IgM and IgY), but IgY is found in higher concentration (5 to 15mg/mL) than IgM (1 to 3mg/mL) and IgA (0.3 to 0.5mg/mL) in serum (ROSE et al., 1974; KOWALCZYK et al., 1985). As for mammals, the IgM is the predominant isotype produced in the avian primary humoral response while IgY is the predominant form in the secondary response (DAVISON et al., 2008).

Chicken IgY is predominantly systemic rather than a secretory antibody but can be also found in duodenal contents, tracheal washings and seminal plasma (LESLIE & CLEM, 1969), besides the egg yolk. The IgY plays a similar biological role as mammalian IgG, being considered the major immunoglobulin providing defense against infectious agents. Additionally, hatched chickens acquire an effective humoral immunity against common avian pathogens when absorb IgY from the egg yolk, until the complete maturation of the immune system (SCHADE et al., 2005).

Transport of IgY from the serum to egg yolk

There is a delay of five to six days since the appearance of IgY in serum until it is found in the yolk (DAVISON et al., 2008). The amount of IgY transferred across the follicular epithelium into the yolk is proportional to the IgY concentrations in serum (HAMAL et el., 2006). However, the concentration of IgY in egg yolk varies greatly between different bird species and even between chicken lines (CARLANDER, 2002). Yolk IgY concentrations were reported to be in the range of 7.9mg/ml to 20-25mg/ml (ROSE et al., 1974; KOWALCZYK et al., 1985), depending on the analytical method used. About 100-200mg of total IgY can be extracted from a single egg with 2-10% being antigen specific (SCHADE et al., 1994; CARLANDER, 2002). IgM and IgA can reach concentrations of 0.15 and 0.7mg/ml into the white eggs, respectively (ROSE et al., 1974). While low amounts of the IgM and IgA isotypes can be detected in the yolk, higher concentrations can be detected in the albumen (CARLANDER, 2002).

Studies performed in chickens have demonstrated that ovarian IgY incorporation happen through a specific receptor-mediated endocytosis and require the Fc region of the intact immunoglobulin for its binding and transport (KITAGUCHI et al., 2008). While both IgY and IgY(∆Fc) can be incorporated into the egg yolk, the full-length form (IgY) is preferentially incorporated (LIU & HIGGINS, 1990). KITAGUCHI et al. (2008) speculate that IgY fragments lacking in the Fc region, Fab and F(ab') ₂ fragments, can be incorporated by fluid-phase endocytosis without binding to the receptor or carrier protein after passing through the filtration gate.

IgY production

Chickens can be used for antibody production throughout their egg laying period. Different routes and various protocols have been reported so far but it is often difficult to compare the different methods described. For practical and economic reasons, chickens kept under field conditions are usually vaccinated intramuscularly in the breast muscle but subcutaneous immunization has also been used (SCHADE et al., 1996; CARLANDER et al., 2002). Injection of the antigen by intramuscular route frequently results in higher antibody levels by day 28 th after immunization (WOOLEY & LANDON, 1995). Chickens immunized by the intramuscular route continue producing specific antibodies during more than 200 days or can be used for the entire laying period depending basically on the antibody titres induced (HORTON et al., 1984; SCHADE et al., 1996).

The total number of immunization required will depend upon the type and dose of the antigen, as well as on the particular adjuvant employed. Whether the antibody titres begin to decrease, booster immunizations can be applied during the laying period. A primary vaccination and a booster should be given preferentially before the laying period, with an interval of 6 weeks for emulsion-type adjuvants and 4 weeks for lipopeptide adjuvants (SCHADE et al., 1996).

According to SCHADE et al. (1996), conventional housing should be used for scientific purpose, when antibodies are used for therapeutic and human purposes the use of specific pathogens free chickens is compulsory. It is also possible to increase yolk antibody production by using a high producing chicken line and by genetic selection within the same line (CARLANDER, 2002).

Chicken IgY exhibits high avidity (10 ⁹L/mol) even after the first immunization. In order to reach similar avidity values (10 ¹⁰ L/mol), a sheep, for example, must receive four boosters (WOOLEY & LANDON, 1995). LARSSON et al. (1998), studied the immune response in chickens using small amounts of mammalian antigens, and observed a good immune response obtained with the use of 0.1-1.0µg of bovine serum albumin. It was suggested that various concentrations of the antigen should be combined with the adjuvant. However, 25-100µg of antigen per immunization are usually used, although it is possible to obtain a good immune response with only 1µg per immunization (CARLANDER, 2002).

Isolation and purification of IgY

Currently, there are several methods of isolation and purification of functionally active chicken IgY from egg yolk described, even for large-scale purification. Nevertheless, purity and yield vary greatly from method to method and require intense optimization for each experiment (CARLANDER, 2002). The choice of a specific method depends on the yield and purity desired, final application of the IgY as well as material cost, technology, labor skills and scale of extraction.

Formerly, widespread adoption of the use of IgY-based protocols have suffered from limitations due to existing IgY purification protocols, especially those concerning the high lipid content of egg yolk which is known to interfere with affinity-based purification steps (HANSEN et al., 1998). For this, all IgY purification methods require an initial delipidation step to extract insoluble lipids and lipoproteins (KO & UHN, 2007; TAN et al., 2012) and then a subsequent step of separation. Among the currently accepted commercial and laboratory delipidation techniques, the most commonly used, involve either the use of water dilution under acidic conditions (AKITA & NAKAI, 1993), chloroform-PEG (POLSON, 1990), polyanionic polysaccharides such as xanthan (HATTA & KIM, 1990), dextran sulphate or other natural gums such as pectin (JENSENIUS et al., 1981; CHANG et al., 2000), solvents such as acetone, detergents such as SDS (SRIRAM & YGEESWARAN, 1999), carrageenan (HATTA & KIM, 1990), aqueous 2-phase system with phosphate and triton X-100 (STALBERG & LARSSON, 2001) or simple freeze and slow thaw cycling (SVENDSEN et al., 1995). These various IgY crude extraction methods give different results considering recovery and purity of levels obtained.

After the extraction step, three types of separation can be applied to eliminate the contaminants: precipitation with ammonium sulfate (KO & UHN, 2007), or sodium sulfate (WOOLEY & LANDON, 1995), or caprylic acid-ammonium sulfate (McLAREN et al., 1994), chromatography (HANSEN, 1998) and filtration (HERNÁNDEZ-CAMPOS et al. 2010). Several of these techniques could be included in one total clean-up procedure. Among these methods, AKITA & NAKAI (1993) suggested the water dilution method under acidic conditions as the most efficient and economical procedure for large-scale production of IgY from egg yolk when compared with polyethylene glycol and dextran sulphate methods in terms of yield, purity and activity of IgY.

Ultrafiltration is one of the best methods of reduce the volume of egg yolk extract, and the efficacy of this methodology is greatly influenced by the presence of lipids or lipoproteins in the solution (KO & UHN, 2007). Therefore, complete removal of lipids or lipoproteins from extract of egg yolk is required. Changes of pH value in egg yolk solution influence the extent of interactions between polysaccharides and proteins, the precipitation of polysaccharide-lipoprotein complexes, and the recovery of immunoactivity (SAMANT et al., 1993). CHANG et al. (2000) reported that addition of 0.1% of λ-carrageenan was effective in removing lipoproteins from the water extract of egg yolk at pH 5. TAN et al. (2012), have demonstrated an alternative methodology to isolate IgY from chicken egg yolks by using a mix of κ-carrageenan, pectin and CaCl2 as delipidation agent with use of ammonium sulphate ((NH ₄) ₂SO ₄) as an IgY precipitation reagent. This method also allowed the isolation of immunologically active IgY which can be used for further downstream immunotechnological processes.

Purity level of IgY from the ammonium sulfate method is higher than the cation exchange chromatography. The chromatography could handle only a small amount of samples, unlike the ammonium sulfate precipitation. Besides, the ammonium sulfate precipitation would be more efficient and useful purification method than cation exchange chromatography for the large-scale preparation of IgY (KO & UHN, 2007). After IgY precipitation by NaCl, column chromatography (JENSENIUS et al., 1981) is frequently used in the final purification step. However, chromatography columns are generally expensive and impractical for the large-scale production of antibodies (KO & UHN, 2007).

IgY in immunodiagnostic

Immunoglobulin Y has distinctive properties which can be exploited in various fields of research, diagnostics and therapy. Since the 1970's, studies were performed in order to elucidate the functional and morphological characteristics of the poorly known immunoglobulin Y. Thereafter, there was an increase in the availability of research regarding IgY reagents (purification kits, standards, and labelled antibodies specifically against IgY), and studies related with IgY production enabling the expansion of applications in immunodiagnostic techniques. In 1995, the production came to be called "IgY Technology" (WARR et al., 1995), which is the internationally accepted term for describing the production and use of this antibody. Furthermore, the "European Centre for the Validation of Alternative Methods" (ECVAM) strongly recommends that yolk antibodies should be used as an alternative to mammalian antibodies for the animal welfare (SCHADE et al., 1996).

The IgY can be harvested from the egg yolk instead of serum, thus making blood sampling obsolete. The antibody productivity of an egg-laying hen is greater than a similar sized mammal (HAU & HENDRIKSEN, 2005) and the IgY concentration in the serum of adult hens can reach approximately 5-7mg/ml. As a laying hen produces approximately 20 eggs per month, over 2 grams of IgY can be isolated during this period corresponding approximately the IgY content of 300ml of serum or 600ml of blood. Only larger mammals can produce equal amounts of serum antibodies. Chicken antibodies, therefore, constitute a much less expensive vehicle for use in diagnostic purposes (CARLANDER, 2002).

The use of IgY can also be advantageous in immunological tests where the interference caused by IgG antibodies can be problematic, particularly, the sensitivity of the assay increases. One example is the rheumatoid factor (RF) that reacts with IgG from different mammalian species and also with mouse monoclonal antibodies (CARLANDER, 2002). RF is usually found in serum samples from patients with rheumatoid arthritis, but can also be found in patients with other diseases and even in 3-5% of healthy individuals. Interference by anti-IgG antibodies and antibody-binding substances have been demonstrated in approximately 40% of serum samples from healthy individuals in an immunoradiometric assay (CARLANDER, 2002). Another fact is the increasing number of patients treated in vivo with mouse monoclonal antibodies. This treatment often evokes an antibody response in the patient resulting in production of human anti-mouse IgG antibodies (HAMA). HAMA may also be found in serum from patients who have not been treated with antibodies. The problem of RF and HAMA interference will increase as the sensitivity of the assay increases. Chicken IgY does not react with RF or HAMA and can be used to avoid interference due to these factors (LARSSON et al., 1992).

Chicken antibodies can also be used to reduce interference caused by mammalian complement activation in immunological assays. The complement cascade can be triggered after adding a fresh and undiluted serum sample to an assay, with subsequent binding of complement components to mammalian antibodies blocking the antigen-binding sites (LARSSON et al., 1992). The controls and standards used for immunological assays generally contain inactivated complement, whereas the complement activity in patient samples might differ, not only among patients but also between samples from the same patient. This difference in activity between the standards and the clinical samples might cause an analytical error (LARSSON et al., 1992; CARLANDER, 2002).

Whenever there is a risk of false positive results due to reactions between Fc region of mammalian antibodies and staphylococcal protein A or streptococcal protein G, chicken antibodies could be a tool to circumvent these problems. Unlike IgG, IgY antibodies do not bind to bacterial Fc receptors, such as staphylococcal protein A or streptococcal protein G (JENSENIUS et al., 1981). However, one disadvantage is that neither protein A nor protein G can be used for the purification of chicken IgY (SCHADE et al., 1996).

Another important advantage arises from the phylogenetic distance and genetic background that distinguishes birds from mammals improving the likelihood that an immune response will be elicited against antigens or epitopes that may be non-immunogenic in mammals (SPILLNER et al., 2012). Due to the evolutionary distance between chicken and mammalian immunoglobulins, IgY recognizes more epitopes when the immunogen used is a mammalian protein highly conserved. This feature can result in amplification of the signal, emphasizing the advantages of using IgY over IgG as the first antibody in some types of immunological reactions (CARLANDER, 2002). It is a well-known concept that a stronger immune response is elicited when the distance between the antigen source and the immune system increases. It has also been shown that chicken antibodies have 3-5 times more affinity to antibodies of pigs than the rabbit IgG for signal amplification in immunological test (HORTON et al., 1984; OLOVSSON & LARSSON, 1993).

The limited flexibility of the avian IgY may account for the inability to precipitate antigens at physiological salt concentrations (WARR et al., 1995). IgY and IgY(∆Fc) both possess two antigen-binding sites and should, in principle, precipitate or agglutinate multivalent antigens but this does not always occur. Most chicken antibodies bind antigen strongly but display precipitating properties only at raised salt concentrations. Duck antibodies generally fail to exhibit efficient precipitation or agglutination reactions (HIGGINS et al., 1988). The non-precipitating duck antibodies do not acquire the ability to precipitate antigen at raised salt concentrations (WARR et al., 1995).

More recently, chicken antibodies libraries have attracted scientific interest with increased reports on the isolation of chicken-derived antibody fragments. Such interest might, at least partially, be attributed to the genetic diversification which is achieved differently in chickens compared with the complexity of the mammalian mechanisms. In other words, avian species utilize a unique mode of DNA recombination, named gene conversion, resulting in a large and diverse antibody repertoire upon antigen priming (SPILLNER et al., 2012). This could be exemplified by the development of a humanized chicken monoclonal anti-IL12 antibody (NISHIBORI et al., 2006). It is also important to keep in mind that recombinant technologies currently available can generate monoclonal IgY or IgY-like antibodies from combinatorial libraries, sometimes without animal immunization (SPILLNER et al., 2012).

Taking together, all these characteristics clearly show substantial advantages of IgY technology in many medical areas, especially for diagnosis. Specific chicken antibodies have been successfully raised against a wide variety of antigens including proteins, peptides, lipid hormones and carbohydrate components from viruses, bacteria, fungi, plants and animals (SCHADE et al., 1994). Several studies have also shown promising results in the development of techniques for immunodiagnostic using IgY, such as immunoassays tests to detect circulating antigen of Schistosoma japonicum (CAI et al., 2012), development of IgY antibodies against proteins of Pythium insidiosum (RANGEL et al., 2010), use in antigen capture-ELISA (JULIARENA et al. 2007; VEERASAMI et al., 2008), among others.

CONCLUSION

IgY antibodies have many advantages over IgG antibodies such as strong avidity, scalable productivity, low assay background, and applicability to many immunoassays providing a strategy for improvement of assay performance and accuracy. Other advantageous features of IgY include a broader antigen-binding host range, absence of activation of the mammalian complement cascade and interaction with rheumatoid factors, or bacterial and human Fc receptors, certainly helping to reduce the costs of clinical and research immunological tests. Finally, the use of IgY represents an alternative method to utilization of mammal IgG and it is in agreement with international efforts, which aim to reduce or even replace animals in scientific experimentation not to mention other desirable characteristics and applications for immunodiagnostic.

Received 04.09.13

Approved 07.08.13

Returned by the author 10.14.13

CR-2013-0483.R1

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# data[].attributes.attachment_link.title
Avian IgY antibodies: characteristics and applications in immunodiagnostic

# data[].attributes.attachment_link.description
Immunoglobulin Y (IgY) is the major antibody isotype in birds, reptiles, amphibia, and lungfish, playing a similar biological role as mammal IgG. Due to its phylogenetic distance, immune diversification and presence in the egg yolk, IgY provide a number of advantages in immunodiagnostic compared to IgG from mammals.

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Terapias para câncer baseados em anticorpos monoclonais. #anticorpos

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Terapias para câncer baseados em anticorpos monoclonais. #anticorpos

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Olá a todos! Trouxe um artigo de revisão que trata de algumas abordagens para tratamento de câncer que utilizam anticorpos monoclonais. Este material traz informações sobre as estruturas dos diversos tipos anticorpos monoclonais e apresenta conjugados de drogas e anticorpos que são eficientes no tratamento.

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Biotecnologia reduz em até 80% custos do tratamento do câncer

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Biotecnologia reduz em até 80% custos do tratamento do câncer

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Esse material fala um pouco sobre a Recepta Biopharma, uma empresa brasileira que vem buscando desenvolver um tratamento com anticorpos monoclonais para baratear em até 80% o tratamento do câncer.
Algumas moléculas desenvolvidas pela empresa já estão sendo testadas nos EUA e apresentaram um benefício clínico de 50%. Já é um bom resultado, não é?

#anticorpos

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Biotecnologia reduz em até 80% custos do tratamento do câncer

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Empresa brasileira de biotecnologia pretende lançar tratamento com anticorpos monoclonais que seria até 80% mais barato do que tratamentos atuais.

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Reino Unido aprova o tratamento contra o coronavírus a base de anticorpos monoclonais de longa duração. (Notícia de 02/12/21) #anticorpos

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Reino Unido aprova o tratamento contra o coronavírus a base de anticorpos monoclonais de longa duração. (Notícia de 02/12/21) #anticorpos

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O laboratório afirma que o sotrovimab atua até mesmo contra a nova variante ômicron, em que apenas uma dose do medicamento pode reduzir o risco de hospitalização e de morte em 79% em adultos considerados de alto risco infectados e com sintomas.

Sotrovimab é um anticorpo monoclonal humano projetado que neutraliza SARS-CoV-2 e vários outros sarbecovírus, diferentes daqueles anticorpos monoclonais que envolve o receptor ACE2.

Sotrovimab contém uma modificação de dois aminoácidos Fc (denominado LS) para aumentar a meia-vida e potencialmente melhorar a biodisponibilidade na mucosa respiratória através de um maior engajamento com o receptor neonatal Fc. Esta modificação pode permitir concentrações terapêuticas por durações mais longas. (Fonte: Early Treatment for Covid-19 with SARS-CoV-2 Neutralizing Antibody Sotrovimab | NEJM)

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A agência de medicamentos do Reino Unido (MHRA, na sigla em inglês) anunciou nesta quinta-feira (2) a aprovação do tratamento da GlaxoSmithKline (GSK) contra o coronavírus a base de anticorpos monoclonais de longa duração. O laboratório afirma que esse remédio atua até mesmo contra a nova variante ômicron, que foi identificada na África do Sul.

OMS relaciona 29 países e territórios que já registraram casos da variante ômicron

O sotrovimab, nome do remédio, se mostrou "seguro e eficaz para reduzir os riscos de hospitalização e de morte nas pessoas com Covid-19 de leve a moderada e com risco grave de desenvolver uma forma severa da doença", afirmou a MHRA em um comunicado.

A GSK afirmou que o tratamento atua contra as mutações chave da nova variante ômicron.

"O sotrovimab demonstrou que atua contra todas as variantes de preocupação e de interesse definidas pela Organização Mundial da Saúde (OMS)", afirmou o laboratório.

De acordo com a MHRA, apenas uma dose do medicamento pode reduzir o risco de hospitalização e de morte em 79% em adultos considerados de alto risco infectados e com sintomas.

O remédio é para pessoas com sintomas leves a moderados que podem desenvolver uma doença mais grave. A agência britânica recomendou o uso a partir do quinto dia de sintomas.

O remédio foi desenvolvido em associação com o laboratório Vir Biotechnology, dos Estados Unidos.

No fim de junho, a Comissão Europeia classificou o tratamento como um dos cinco mais promissores contra o coronavírus.

O sotrovimab é o segundo tratamento contra o coronavírus aprovado em um mês pelo Reino Unido, depois do molnupiravir, comprimidos do laboratório americano Merck Sharp &amp; Dohme (MSD), que recebeu autorização em novembro.

Veja os vídeos mais assistidos do g1

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Reino Unido aprova segundo medicamento contra o coronavírus

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A agência de medicamentos do Reino Unido (MHRA, na sigla em inglês) anunciou nesta quinta-feira (2) a aprovação do tratamento da GlaxoSmithKline (GSK) contra o coronavírus a base de anticorpos monoclonais de longa duração. O laboratório afirma que esse remédio atua até mesmo contra a nova variante ômicron, que foi identificada na África do Sul.

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Estrutura e função do anticorpo: a base para a terapia de engenharia #anticorpos

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Estrutura e função do anticorpo: a base para a terapia de engenharia #anticorpos

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Olá, pessoal. Hoje trago para vocês um material bem completo e atualizado a respeito de anticorpos. Apesar do material ser extenso, achei interessante trazer dado que esse foi o conteúdo recomendado pelo meu orientador para ter como base para a minha pesquisa que está relacionada com o tema.

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Antibody Structure and Function: The Basis for Engineering Therapeutics

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Antibodies and antibody-derived macromolecules have established themselves as the mainstay in protein-based therapeutic molecules (biologics). Our knowledge of the structure–function relationships of antibodies provides a platform for protein ...

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Olá, pessoal! Dessa vez trago uma pequena revisão muito interessante sobre anticorpos monoclonais e sua aplicação em biotecnologia. O artigo versa sobre conceito de anticorpos monoclonais, etapas para sua produção e suas aplicações, como diagnóstico, análises bioquímicas, terapêutica e, ainda, entrega de drogas. Vale a pena ler!
#anticorpos

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A review on Monoclonal antibody and its application in

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O uso de anticorpos neutralizantes e  Anti-RBD contra a Covid-19 #anticorpos

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O uso de anticorpos neutralizantes e  Anti-RBD contra a Covid-19 #anticorpos

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Boa noite a todos. Segue um curto artigo explicando a aplicação de anticorpos neutralizantes e anti-rbd para o combate à covid-19, mesmo após a infecção.

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Bertholdo Consultoria - BRTLOJA - 2.1 - 10/2015

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Artigos - Anticorpos Neutralizantes e Anti-RBD na Covid-19

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A atual pandemia de COVID-19, declarada em 11 de março de 2020 pela Organização Mundial da Saúde, teve seus primeiros casos relatados em dezembro de 2019, em Wuhan, província de
Hubei, na China. Trata-se de uma doença respiratória decorrente da infecção causada pelo novo coronavírus, posteriormente…

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Respostas dos Anticorpos às mutações de SARS-CoV-2 #anticorpos

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Respostas dos Anticorpos às mutações de SARS-CoV-2 #anticorpos

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Oi gente!!
Trouxe aqui um artigo que discute como as novas variantes de SARS-CoV-2 podem apresentar resistências terapêuticas e escapes da ação de anticorpos. Achei esse artigo bem interessante por permitir aprofundar um pouco nossos estudos quanto às características dos anticorpos e suas funcionalidades, além de ter como base um tema ainda muito atual o da pandemia de covid-19. #anticorpos

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Emerging mutations in the SARS-CoV-2 variants and their role in antibody escape to small molecule-based therapeutic resistance

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Several clinical trials started during the COVID-19 pandemic to discover effective therapeutics led to identifying a few candidates from the major cli…

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Estudo da Fiocruz a respeito dos anticorpos contra covid-19 no leite materno #anticorpos

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Estudo da Fiocruz a respeito dos anticorpos contra covid-19 no leite materno #anticorpos

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Olá, pessoal. Trago uma notícia do portal da Fiocruz que trata do processo de um estudo que examina a importância de anticorpos contra covid-19, no leite materno de mulheres grávidas, para os bebês. Esse estudo é de extrema importância, porque analisa os possíveis benefícios para o bebê em relação à imunidade, oriunda dos anticorpos, contra o covid-19. #anticorpos

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Em Manaus, a população estimada de gestantes é de 28,4 mil mulheres e de puérperas, 4,7 mil. Segundo dados do Vacinômetro Covid-19 Manaus, até o momento, somente 6.606 gestantes e 1.680 puérperas receberam a primeira dose da vacina. Coordenado por pesquisadores do Instituto Leônidas & Maria Deane (Fiocruz Amazônia) e da Universidade Federal do Amazonas (Ufam), um estudo está investigando a importância dos anticorpos anti-Sars-CoV-2, presentes no leite materno, na proteção do bebê contra Covid-19.

Atualmente, o projeto procura voluntárias puérperas para participar da pesquisa (foto: Eduardo Gomes/Fiocruz Amazônia)

A equipe do projeto PROTECTCoV-19 recruta grávidas, a partir da 28º semana de gestação, e puérperas, com idade maior ou igual a 18 anos, para participar do estudo, que pretende saber o papel dos anticorpos do leite materno na proteção contra Covid-19. Até o momento, 276 mulheres já foram inseridas no projeto. O recrutamento continuará acontecendo, até a equipe atingir a marca de 800 participantes.

A química de alimentos, Lirna Souza, de 33 anos, resolveu participar do estudo logo que soube de sua realização, pois acredita que além de encontrar respostas para seus questionamentos, ajudará também nas descobertas científicas. "Quando vi as informações sobre o projeto, já pensei em mandar mensagem para me voluntariar e participar. Existe aquela curiosidade de sabermos se realmente a gente vai produzir os anticorpos após a vacinação e se vamos passar para o bebê através do leite. Além de ser uma curiosidade de mãe, participar desse estudo vai ser bom para a pesquisa, para a ciência e para outras pessoas que possuem esse mesmo questionamento", relata.

Atualmente, o projeto PROTECTCoV-19 procura voluntárias puérperas para participar da pesquisa. Para participar do estudo, as interessadas devem preencher o formulário online.

Depois de preencher o formulário, a participante receberá visita domiciliar para conhecer todas as etapas da pesquisa, incluindo a coleta do leite e amostra sanguínea. A inclusão na pesquisa está vinculada à assinatura de Termo de Consentimento Livre e Esclarecido (TCLE).

Para a Biomédica, Sabrina Maia, de 23 anos, que compõe a equipe do projeto, o contato com as grávidas e puérperas, durante as coletas, tem sido significativo. "Essa experiência tem sido de muito aprendizado. É muito significativo essa troca com as mulheres, especialmente por abordamos a importância da amamentação e da vacinação, para a proteção dos bebês", destaca.

Segundo os pesquisadores, já existem estudos demonstrando que em grávidas e puérperas vacinadas são detectados anticorpos contra Sars-CoV-2 no leite materno (foto: Eduardo Gomes/Fiocruz Amazônia)

Segundo os pesquisadores, a vacinação de grávidas e puérperas é uma ação de grande avanço na luta contra a Covid-19. Segundo os coordenadores do projeto, Pritesh Lalwani e Jaila Borges, já existem estudos demonstrando que em grávidas e puérperas vacinadas são detectados anticorpos contra Sars-CoV-2 no leite materno, o que provavelmente beneficiará o bebê que é amamentado.

Para Pritesh Lalwani, pesquisador da Fiocruz Amazônia, é necessário que o aleitamento materno seja observado não somente do ponto de vista nutricional, mas também como proteção aos bebês. "Leite não somente é uma fonte de nutrição, mas também fonte de anticorpos que a mãe passa para o bebê. A vacinação ainda está baixa na população de gravidas e puérperas. O aleitamento materno ajuda a proteger os bebês nos primeiros meses de vida, quando a resposta imunológica está sendo formada", explicou o pesquisador.

Nos próximos 30 dias, os pesquisadores pretendem divulgar os primeiros resultados deste estudo, mostrando um retrato da distribuição dos anticorpos no leite materno. O projeto PROTECTCoV-19 ganha novo apelo no mês de agosto, marcado por campanhas que simbolizam o mês do aleitamento materno no Brasil e a semana mundial da amamentação.
Agosto Dourado
A campanha Agosto Dourado simboliza a luta pelo incentivo à amamentação. De acordo com a Organização Mundial da Saúde (OMS) e o Fundo das Nações Unidas para a Infância (Unicef), por ano, cerca de 6 milhões de vidas são salvas por causa do aumento das taxas de amamentação exclusiva até o sexto mês de idade.

A Semana Mundial de Aleitamento Materno, ocorreu de 1 a 7 de agosto, nesta edição com o tema Proteger a amamentação é uma responsabilidade de todos. O tema está alinhado com os Objetivos do Desenvolvimento Sustentável (ODS), que destacam os vínculos entre amamentação e sobrevivência, saúde e bem-estar de mulheres, crianças e nações.

A história da campanha teve início em 1990, em um encontro da Organização Mundial de Saúde com a Unicef, momento em que foi gerado um documento conhecido como Declaração de Innocenti. Para cumprir os compromissos assumidos pelos países após a assinatura deste documento, em 1991 foi fundada a Aliança Mundial de Ação pró-Amamentação (Waba).

Em 1992, a WABA criou a Semana Mundial de Aleitamento Materno e, todos os anos, define o tema a ser explorado, além de lançar materiais que são traduzidos em 14 idiomas.

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Estudo investiga papel dos anticorpos contra Covid-19 no leite materno

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Em Manaus, a população estimada de gestantes é de 28,4 mil mulheres e de puérperas, 4,7 mil. Segundo dados do Vacinômetro Covid-19 Manaus, até o momento, somente 6.606 gestantes e 1.680 puérperas receberam a primeira dose da vacina.

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Terapias imunológicas envolvendo o uso de anticorpos monoclonais na rejeição de transplantes renais #anticorpos

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Terapias imunológicas envolvendo o uso de anticorpos monoclonais na rejeição de transplantes renais #anticorpos

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O presente trabalho documenta uma alternativa para pacientes que são submetidos a processos de transplante renal, os quais enfrentam problemas frequentemente relacionados a rejeição por parte do organismo. A utilização de alguns medicamentos imunossupressores em diversas situações é associada a efeitos colaterais fortes e variados, e a utilização de terapias biológicas fundamentadas em anticorpos monoclonais surge como proposta efetiva para aplicação clínica.

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Notícia pertinente aos coquetéis de anticorpos e a nova variante Omicron #anticorpos

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Notícia pertinente aos coquetéis de anticorpos e a nova variante Omicron #anticorpos

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A empresa Regeneron disse que seu coquetel de drogas com anticorpos perdeu eficácia contra a nova variante, o que é preocupante.

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Covid-19 Antibody Drugs Are Challenged by Omicron, Preliminary Testing Indicates

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Regeneron said its antibody drug cocktail was found to lose effectiveness against the new variant, a sign that some therapies might need modifying.

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Visão geral sobre o desenvolvimento de anticorpos terapêuticos para o tratamento de doenças #anticorpos 

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Visão geral sobre o desenvolvimento de anticorpos terapêuticos para o tratamento de doenças #anticorpos 

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Olá, pessoal!
Hoje trago para compartilhar com vocês um artigo de revisão publicado em 2020 que trata do desenvolvimento de anticorpos terapêuticos para o desenvolvimento de doenças. Ele aborda tópicos essenciais, como o mercado (como, por exemplo, o dado de que se espera que anticorpos monoclonais terapêuticos gerem uma receita de US$ 300 bilhões até 2025!!).
O artigo também trata das aplicações e metodologias usadas no desenvolvimento desses anticorpos, bem como perspectivas futuras para a área. Vale a pena a leitura!

#anticorpos

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development of therapeutic antibodies for the treatment of diseases

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O uso de anticorpos de domínio único como agentes neutralizantes da Covid-19 #anticorpos

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O uso de anticorpos de domínio único como agentes neutralizantes da Covid-19 #anticorpos

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Olá pessoal! Encontrei essa abordagem muito interessante sobre o uso de anticorpos de camelos e lhamas (camelídeos) que se ligam a alvos usando pequenos domínios de proteína, os denominados nanocorpos. Esses nanocorpos podem ser produzidos em formatos altamente eficazes contra as variantes do COVID-19 que são impermeáveis ​​a muitos anticorpos convencionais desenvolvidos como terapias já que podem produzir anticorpos de cadeias pesadas que reconhecem os antígenos usando domínios VHH únicos e variáveis. A vantagem dos nanocorpos é o seu tamanho pequeno, possibilitando a sua penetração nos tecidos e o reconhecimento de epítopos que normalmente são inacessíveis aos anticorpos convencionais.

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Camels and llamas make antibodies that bind to targets using small, 'nanobody' protein domains. Mice have now been engineered to make nanobodies that might be more effective than conventional antibodies in treating COVID-19.

James E. Voss

James E. Voss is in the Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California 92037, USA.

How might the emergence of SARS-CoV-2 variants affect efforts to control the COVID-19 pandemic? The threat posed by such variants is focusing attention on vaccination and therapeutic options to grapple with the evolving coronavirus. Writing in Nature, Xu et al. describe the development of a genetically engineered mouse that can generate antibodies similar to those produced by camelids (an animal grouping that includes camels and llamas). These antibodies recognize targets using a single, small protein domain called a nanobody, also known as a VHH domain. Vaccination of these mice using proteins based on the SARS-CoV-2 spike protein resulted in the generation of antiviral nanobodies. These nanobodies could be produced in formats that were highly effective against COVID-19 variants that are impervious to many conventional antibodies being developed as therapies.

Conventional antibodies such as those produced by humans and mice recognize antigens (protein fragments of disease-causing agents) by means of two variable domains (VH and VL), which are components of separate heavy- and light-chain proteins (Fig. 1). By contrast, camelids and cartilaginous fishes (such as sharks) can make heavy-chain-only antibodies that recognize antigens using single, variable VHH domains, or nanobodies. One advantage of nanobodies is their small size, which enables them to penetrate tissues and recognize epitopes (the region of an antigen to which an antibody binds) that are normally inaccessible to conventional antibodies.

Nanobodies are generally extremely stable and soluble, and their modular nature means they can be readily expressed alone or in a variety of formats: for example, fused to the human antibody Fc domain that boosts defence responses. These features make nanobody-based therapeutics a promising alternative to conventional monoclonal antibodies (antibodies with heavy and light chains that have a particular amino-acid sequence and antigen specificity). However, although 2021 saw regulatory approval of the 100th monoclonal-antibody treatment, only one nanobody-based therapy has been approved for clinical use by the US Food and Drug Administration (FDA).

Currently, the only human monoclonal antibodies in advanced development as COVID-19 therapies (see go.nature.com/3xt9ku2) are a type called neutralizing antibodies (which block viral entry). Most of these were obtained from the antibody-producing cells of people who were infected during the first wave of the pandemic. Such antibodies target the receptor-binding domain (RBD) of the spike protein; the virus uses this domain to bind to the receptor that enables it to infect cells. Human monoclonal antibodies are strongly preferred for clinical development because they are highly specific, are easily manufactured and work in concert with, and are well tolerated by, the human immune system. However, there are strong arguments in favour of developing alternative, nanobody-based therapeutics in response to evolving human respiratory viruses such as SARS-CoV-2.

Since the virus began infecting people more than a year ago, the collective human neutralizing-antibody response generated against SARS-CoV-2 has applied a strong selection pressure on the spike-protein RBD. In fact, only two or three amino-acid-residue changes in versions of the virus that became dominant during the second and third waves of the pandemic were enough to render those versions substantially more resistant to neutralization by antibodies generated during the first wave - as assessed by tests on blood samples, known as convalescent serum, from individuals who have had COVID-19.

It therefore follows that monoclonal-antibody therapies mined from antibody responses generated during the first wave of the pandemic might quickly become obsolete. RBD epitopes of the spike protein that are recognized by neutralizing nanobodies, and that are not under selection pressure as a consequence of epitope recognition by human antibodies, might provide COVID-19 antivirals that do not quickly become ineffective as viral variants emerge. Broadly neutralizing nanobodies - nanobodies that recognize evolutionarily conserved epitopes of the spike protein - might even be useful against other coronaviruses with the capacity to drive a future pandemic.

The small and soluble nature of nanobodies means that they should be inexpensive to produce and easy to administer directly by inhalation to target key initial sites of viral replication in the respiratory tract. A study in hamsters, assessing the intranasal aerosol delivery of neutralizing nanobodies targeting SARS-CoV-2, reports that nanobodies were effectively deposited throughout the animals' respiratory tract, and that this treatment notably reduced the level of virus. As long as nanobody therapies are administered only once over a short period of time to people with an acute infection, then strong immune responses should not be directed towards the nanobody itself, rendering it ineffective. The issue of such immune responses is generally a concern in relation to monoclonal-antibody therapies being developed to treat diseases that require repeated antibody administration over longer periods of time.

Although there has been some hesitancy in moving nanobodies to the clinic, many studies have found that potently neutralizing nanobodies can be elicited in camelids using SARS-CoV-2 vaccines based on the spike protein ⁻. Xu and colleagues now offer a way forward through their generation of heavy-chain-only antibody-producing 'nanomice'. The approach offers a system that should make nanobody discovery easier, faster and less expensive than was previously possible. Laboratory facilities to care for mice are inexpensive and ubiquitous, the mouse immune system is well understood, and high-quality tools such as those needed for cell sorting are readily available. Furthermore, immunizations in mice can occur on a much faster timescale than is possible for larger animal models - an important consideration when a rapid response to a newly emerging pandemic is required.

To generate these nanomice, Xu et al. replaced a large region of genomic DNA, containing all of the mouse heavy-chain variable ( V) genes, with a region of DNA comprising 30 heavy-chain V genes derived from alpaca, dromedary and Bactrian camels. Each gene was fused to a DNA sequence that enabled the gene to form the usual connection (through a process termed recombination) to mouse heavy-chain D and J genes to make complete VHH genes. The V genes were also fused to promoter DNA sequences so that the VHH genes could be expressed in mouse antibody-producing B cells. Each developing B cell could indeed recombine a single camelid V, mouse D and mouse J gene to generate B-cell populations expressing different VHH- gene sequences as heavy-chain-only antibodies. The authors demonstrated that these cells could respond normally to immunization, undergoing a process (termed affinity maturation) that boosts the potency and specificity of antibodies for the antigen that they respond to.

Xu and colleagues then immunized three nanomice and one llama with the SARS-CoV-2 spike protein and RBD. They identified neutralizing nanobodies in both animal models. These nanobodies could be formatted to be expressed as three tandem nanobody copies fused to a human antibody Fc domain (Fig. 1). This domain is a key feature of conventional antibodies: it enables an antibody to transit around the body, improves the antibody's lifespan and boosts interactions with other components of the immune system. This format using tandem nanobodies should help to boost antigen binding by the antibodies. The authors' evidence indicates that these engineered antibodies could potently neutralize all of the tested SARS-CoV-2 variants of concern (viruses with RBD mutations and which were associated with the second and third waves of the pandemic). Moreover, the proteins from nanomice recognized evolutionarily conserved epitopes on the RBD that do not overlap with regions commonly recognized by human antibodies.

The COVID-19 pandemic presents a unique opportunity for nanobodies to shine in the clinic, and the nanomouse platform is poised to help bring higher-quality therapeutic-nanobody options to the table, pushing the odds of success even higher. Just as the development of mice with antibodies containing human variable domains (such as Regeneron's VelocImmune mouse) has helped to deliver the 100th FDA-approved monoclonal antibody, perhaps the nanomouse will give nanobody-based therapeutics a push in the same direction.

Competing Interests

The author declares no competing interests.

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Engineered single-domain antibodies tackle COVID variants

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Camels and llamas make antibodies that bind to targets using small, 'nanobody' protein domains. Mice have now been engineered to make nanobodies that might be more effective than conventional antibodies in treating COVID-19. James E. Voss James E. Voss is in the Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California 92037, USA.

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Olá, pessoal! Este material apresenta informações acerca de dois anticorpos monoclonais aprovados por vários países como Estados Unidos, Canadá e Suiça, para uso no tratamento da COVID-19. O medicamento é uma associação entre os anticorpos casirivimabe e imdevimabe, desenvolvida pela farmacêutica Regeneron, que atua contra a proteína spike do SARS-CoV-2.

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Anticorpos produzidos em laboratório facilitam busca por medicamentos      #anticorpos

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Anticorpos produzidos em laboratório facilitam busca por medicamentos      #anticorpos

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Oie gente. Trago essa notícia do Jornal da USP de 2018 que fala sobre a relação dos anticorpos com os peptídeos e como isso permite estabelecer possíveis alvos para a produção de fármacos. Isso é mais uma das aplicações dos anticorpos na área da saúde em biotecnologia. Espero que gostem!

#anticorpos

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AZD7442 (coquetel de anticorpos) reduz o risco de desenvolvimento de sintomas severos de Covid-19 e mortes #anticorpos

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AZD7442 (coquetel de anticorpos) reduz o risco de desenvolvimento de sintomas severos de Covid-19 e mortes #anticorpos

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Olá a todos,
Gostaria de compartilhar essa notícia que trata dos 🤬 realizados pela Astrazeneca com um coquetel (AZD7442) de anticorpos monoclonais , tal formulação reduziu em cerca de 67% o risco do paciente desenvolver sintomas severos de Covid-19 se comparado a medicações placebo, tal teste foi realizado com pacientes da zona de risco da doença. Tal coquetel é derivado de dois anticorpos monoclonais de células B doadas de pacientes recuperados da doenças, tais células são linfócitos que produzem esses anticorpos que possuem a capacidade de se ligar a regiões específicas da proteína spike 1 de ligação do Sars-CoV-2, sendo otimizados pela pesquisa realizada, tais anticorpos tiveram um aumento de meia vida e redução a ligação com receptores Fc, o que aumentou ainda mais sua eficiência. Além disso, 🤬 in vitro detectaram atividade de neutralização de certas variantes pela aplicação do coquetel. Os 🤬 seguem avançando e serão acompanhados pelos próximos meses, tendo assim um futuro potencial no desenvolvimento de tratamentos a Covid-19 a partir da aplicação desses anticorpos.
#anticorpos

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Positive high-level results from the TACKLE Phase III COVID-19 treatment trial showed AstraZeneca's AZD7442, a long acting antibody (LAAB) combination, achieved a statistically significant reduction in severe COVID-19 or death compared to placebo in non-hospitalised patients with mild-to-moderate symptomatic COVID-19.

A total of 90% of participants enrolled were from populations at high risk of progression to severe COVID-19, including those with co-morbidities.

The trial met the primary endpoint, with a dose of 600mg of AZD7442 given by intramuscular (IM) injection reducing the risk of developing severe COVID-19 or death (from any cause) by 50% compared to placebo in outpatients who had been symptomatic for seven days or less. The trial recorded 18 events in the AZD7442 arm (18/407) and 37 in the placebo arm (37/415). The LAAB was generally well tolerated in the trial.

In a prespecified analysis of participants who received treatment within five days of symptom onset, AZD7442 reduced the risk of developing severe COVID-19 or death (from any cause) by 67% compared to placebo, with nine events in the AZD7442 arm (9/253) and 27 in the placebo arm (27/251).

AZD7442 is the first LAAB with Phase III data to demonstrate benefit in both prophylaxis and treatment of COVID-19 and is easily administered by IM injection.

Hugh Montgomery, Professor of Intensive Care Medicine at University College London, and TACKLE principal investigator, said: "With continued cases of serious COVID-19 infections across the globe, there is a significant need for new therapies like AZD7442 that can be used to protect vulnerable populations from getting COVID-19 and can also help prevent progression to severe disease. These positive results show that a convenient intramuscular dose of AZD7442 could play an important role in helping combat this devastating pandemic."

Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca, said: "These important results for AZD7442, our long-acting antibody combination, add to the growing body of evidence for use of this therapy in both prevention and treatment of COVID-19. An early intervention with our antibody can give a significant reduction in progression to severe disease, with continued protection for more than six months."

TACKLE included 903 participants in a 1:1 randomisation AZD7442 to placebo. The primary analysis was based on 822 participants.

AstraZeneca will be discussing the data with health authorities. On 5 October 2021, the Company announced that it had submitted a request to the US Food and Drug Administration for Emergency Use Authorisation for AZD7442 for prophylaxis of COVID-19.

Full results from TACKLE will be submitted for publication in a peer-reviewed medical journal and presented at a forthcoming medical meeting.
Notes
TACKLE
TACKLE is a Phase III, randomised, double-blind, placebo-controlled, multi-centre trial assessing the safety and efficacy of a single 600mg IM dose of AZD7442 compared to placebo for the outpatient treatment of COVID-19. The trial was conducted in 96 sites in Brazil, Czech Republic, Germany, Hungary, Italy, Japan, Mexico, Poland, Russian Federation, Spain, Ukraine, UK and US. 903 participants were randomised (1:1) to receive either AZD7442 (n = 452) or saline placebo (n = 451), administered in two separate, sequential IM injections.

Participants were adults 18 years-old and over who were non-hospitalised with mild-to-moderate COVID-19 and symptomatic for seven days or less. Participants had a documented laboratory-confirmed SARS-CoV-2 infection, as determined by a molecular test (antigen or nucleic acid) from any respiratory tract specimen (e.g. oropharyngeal, nasopharyngeal, or nasal swab or saliva) collected no more than three days prior to day one.

The primary efficacy endpoint was the composite of either severe COVID-19 or death from any cause through day 29. Subjects will continue to be followed for 15 months.

Approximately 13% of participants were 65 years and over. In addition, 90% had baseline co-morbidities and other characteristics that put them at high risk of progression to severe COVID-19, including cancer, diabetes, obesity, chronic lung disease or asthma, cardiovascular disease or immunosuppression. Approximately 62% were White/Caucasian, 4% Black/African-American, 6% Asian and 24% American Indian or Alaskan Native. Approximately 52% of participants were Hispanic/Latino.

AZD7442 is a combination of two LAABs - tixagevimab (AZD8895) and cilgavimab (AZD1061) - derived from B-cells donated by convalescent patients after SARS-CoV-2 virus. Discovered by Vanderbilt University Medical Center and licensed to AstraZeneca in June 2020, the human monoclonal antibodies bind to distinct sites on the SARS-CoV-2 spike protein ¹ and were optimised by AstraZeneca with half-life extension and reduced Fc receptor and complement C1q binding. The half-life extension more than triples the durability of its action compared to conventional antibodies and could afford up to 12 months of protection from COVID-19 following a single administration ²⁻⁴; data from the Phase I trial show high neutralising antibody titres for at least nine months. ⁵ The reduced Fc receptor binding aims to minimise the risk of antibody-dependent enhancement of disease - a phenomenon in which virus-specific antibodies promote, rather than inhibit, infection and/or disease. ⁶

In August 2021, AstraZeneca announced AZD7442 demonstrated a statistically significant reduction in the risk of developing symptomatic COVID-19 in the PROVENT Phase III pre-exposure prevention trial.

AZD7442 is also being studied as a potential treatment for hospitalised COVID-19 patients as part of the National Institute of Health's ACTIV-3 trial and in an additional collaborator hospitalisation treatment trial.

AZD7442 is being developed with support from the US Government, including federal funds from the Department of Health and Human Services; Office of the Assistant Secretary for Preparedness and Response; Biomedical Advanced Research and Development Authority in partnership with the Department of Defense; Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense, under Contract No. W911QY-21-9-0001.

In preclinical experiments, data show the LAABs were able to block the binding of the SARS-CoV-2 virus to host cells and protect against infection in cell and animal models of disease. ⁷ Additional in vitro findings demonstrate AZD7442 neutralises recent emergent SARS-CoV-2 viral variants, including the Delta and Mu variants. ⁸

Under the terms of the licensing agreement with Vanderbilt, AstraZeneca will pay single-digit royalties on future net sales.

AstraZeneca
AstraZeneca (LSE/STO/Nasdaq: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide. Please visit astrazeneca.com and follow the Company on Twitter @AstraZeneca.

For details on how to contact the Investor Relations Team, please click here. For Media contacts, click here.

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AZD7442 reduced risk of developing severe COVID-19 or death in TACKLE Phase III outpatient treatment trial

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Positive high-level results from the TACKLE Phase III COVID-19 treatment trial showed AstraZeneca's AZD7442, a long acting antibody (LAAB) combination, achieved a statistically significant reduction in severe COVID-19 or death compared to placebo in non-hospitalised patients with mild-to-moderate symptomatic COVID-19.

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Fábrica de Anticorpos Monoclonais do Butantan

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Fábrica de Anticorpos Monoclonais do Butantan

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Oi, pessoal! Pesquisando mais sobre o tema de anticorpos encontrei esse vídeo do Canal Butantan que fala um pouco sobre esse projeto incrível de construção de uma fábrica de produção de anticorpos monoclonais para utilização no SUS!

Essa é com certeza uma notícia animadora para todos. Porém, pesquisando mais sobre a fábrica, vi que ela ainda não começou a funcionar, embora a obra já esteja finalizada, por falta de investimentos :(

(https://g1.globo.com/jornal-nacional/noticia/2021/11/03/fabrica-de-remedios-de-alto-custo-esta-parada-em-sp-por-falta-de-acao-do-ministerio-da-saude.ghtml)

A expectativa é que esse problema possa ser resolvido e que essa fábrica possa gerar bons resultados no setor biotecnológico brasileiro.

#anticorpos

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iai bioteckers, essa reportagem fala sobre o desenvolvimento de uma vacina de DNA contra tuberculose feita por um brasileiro. Rodrigues, o criador da vacina usa a proteína Hsp65, que induz a produção de interferon gama, proteína envolvida na proteção do organismo contra bactérias como a Mycobacterium tuberculosis. Essa vacina tem se mostrado eficiente tanto na ação preventiva, quanto na ação terapêutica, sendo usada capaz de ajudar na eliminação de infecções jpa estabelecidas.

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Próximo Texto | Índice

BIOTECNOLOGIA
Sistema utiliza método seguro e eficiente para inserir material genético no corpo e combater a tuberculose
Brasileiro desenvolve vacina de DNA

ISABEL GERHARDT
ENVIADA ESPECIAL A CAXAMBU

Uma nova forma de liberação de drogas no organismo, que busca a minimização dos efeitos colaterais e das deficiências dos sistemas empregados atualmente, foi o tema de um dos simpósios inaugurais da 29 Reunião Anual da SBBq (Sociedade Brasileira de Bioquímica e Biologia Molecular), que está sendo realizada desde sábado em Caxambu, MG.
Entre os novos sistemas apresentados está o uso de partículas como transportadoras de material genético, que poderão ser utilizadas na criação de vacinas de DNA. As partículas usadas, chamadas poliméricas biodegradáveis, são microesferas produzidas a partir de polímeros (uma espécie de plástico em que se repetem moléculas de uma mesma unidade formadora).
O líder do projeto, José Maciel Rodrigues Júnior, da Faculdade de Farmácia da UFMG (Universidade Federal de Minas Gerais), explica que o sucesso das vacinas de DNA é definido por proteção máxima com o mínimo de doses administradas.
O princípio da vacina de DNA é injetar na célula o gene correspondente ao de uma proteína que se deseja produzir naquele organismo para desencadear a reação do sistema imunológico (de defesa).
O que muitas vezes acontece, segundo o pesquisador, é que o DNA, depois de ser injetado, por não se integrar de forma estável no núcleo da célula, é perdido. Com isso, a vacina não funciona, pois não há a produção da proteína de interesse, pelo menos de forma continuada.
O método mais comum para introduzir o DNA na célula consiste na utilização de vírus "desarmados", que não são capazes de causar doenças. No entanto, mesmo desarmados, esses vírus podem causar reações adversas.
No sistema desenvolvido por Rodrigues, devido às propriedades químicas das microesferas (que funcionam como invólucro do DNA), o material genético pode ser liberado aos poucos, permitindo a duração contínua da produção da proteína e, portanto, da vacina.

Devagar e sempre
Rodrigues utiliza a proteína Hsp65 - sintetizada quando há um aumento de temperatura na célula ou em resposta a outros tipos de estresse-, que induz a produção de interferon gama.
O interferon gama é uma proteína que está envolvida na proteção do organismo contra bactérias como a Mycobacterium tuberculosis, responsável pela morte de cerca de 3 milhões de pessoas no mundo por ano.
"Essa vacina poderá ser usada para tratar qualquer infecção que possa ser reduzida pela produção de interferon", diz Rodrigues.

Proteção e tratamento
A Hsp65 demonstrou ser capaz não só de agir de forma preventiva, mas também de eliminar infecções já estabelecidas, como uma vacina terapêutica. "Em testes com camundongos já infectados, a vacina com a proteína Hsp65 induziu a proteção. Por isso, ela pode ser utilizada como tratamento", explica o pesquisador.
A vacina com o gene da proteína Hsp65 deve demorar alguns anos antes de chegar ao mercado e ser administrado em humanos.
Como essa vacina também tem interesse veterinário, esclarece Rodrigues, é possível que ela esteja no mercado, com esse fim, mais cedo.
"Já estamos desenvolvendo medicamentos antiparasitários e antibióticos com a indústria nacional usando essa tecnologia", disse Rodrigues. "Introduzimos algumas inovações que iremos patentear."

Próximo Texto: Medicina: Anticorpos específicos podem controlar o sistema de defesa
Índice

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Folha de S.Paulo - Biotecnologia: Brasileiro desenvolve vacina de DNA - 29/05/2000

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Próximo Texto | Índice BIOTECNOLOGIA Sistema utiliza método seguro e eficiente para inserir material genético no corpo e combater a tuberculose Brasileiro desenvolve vacina de DNA ISABEL GERHARDT ENVIADA ESPECIAL A CAXAMBU Uma nova forma de liberação de drogas no organismo, que busca a minimização dos efeitos colaterais e das deficiências dos sistemas empregados atualmente, foi o tema de um dos simpósios inaugurais da 29 Reunião Anual da SBBq (Sociedade Brasileira de Bioquímica e Biologia Molecular), que está sendo realizada desde sábado em Caxambu, MG.

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A biotecnologia industrial por trás da produção de vacinas

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A biotecnologia abrange todas as áreas imagináveis. Em meio à pandemia do novo coronavírus, isso ficou ainda mais evidente com a produção de vacinas em massa para a população.

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Um dos maiores receios nas pessoas que não confiam nas vacinas do Covid-19 é o fato delas terem sido produzidas tão rapidamente, então trouxe esse link com um texto explicando sobre esse fato.

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Um dos maiores receios nas pessoas que não confiam nas vacinas do Covid-19 é o fato delas terem sido produzidas tão rapidamente, então trouxe esse link com um texto explicando sobre esse fato.

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O intuito principal desse texto é informa e sensibilizar a população sobre a importância, segurança e eficácia da vacinação.

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Como as vacinas para a Covid-19 ficaram prontas tão rápido?

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Pode confiar! As primeiras vacinas aprovadas para conter o Sars-Cov-2 foram desenvolvidas em menos de um ano, mas sem abrir mão de segurança e eficácia.

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Olá, pessoal.

Hoje trago para vocês uma matéria da Veja Saúde sobre a nova vacina contra a dengue no Brasil. Esta nova vacina é produzida pela farmacêutica japonesa Takeda, grande conhecida pela produção de medicamentos e pelos tratamentos gastrointestinais e de câncer.

Atualmente, temos uma vacina contra a dengue, que é apenas distribuída na rede particular e tem limitações, como só poder ser aplicada em pessoas que já foram infectadas pelo vírus, isso porque o imunizante pode provocar um quadro que agrava a situação de um infectado pela dengue após a administração da vacina em pessoas não infectadas anteriormente.

A nova vacina é produzida utilizando técnicas de engenharia genética, onde partes dos 4 sorotipos da dengue estão presentes na superfície do patógeno atenuado.

Outra vantagem é que a vacina pode ser aplicada em um grande range de idades, partindo de 4 anos até 60 anos.

Dito isso, a expectativa é que a vacina seja aprovada pela Anvisa e seja negociada para disponibilização pelo SUS em 2022.

#vacinas

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A farmacêutica Takeda solicitou à Agência Nacional de Vigilância Sanitária (Anvisa) o registro de uma nova vacina contra a . A TAK-003 é feita com uma versão modificada do vírus vivo atenuado e protege contra os quatro sorotipos da doença.

No estudo de fase 3, a vacina demonstrou eficácia geral de 80,2% na prevenção de casos confirmados de dengue. A proteção foi ainda maior contra hospitalizações (90%) e dengue hemorrágica, a versão mais grave da doença (85%).

O trabalho segue em andamento, acompanhando cerca de 20 mil crianças e adolescentes recrutados entre 2016 e 2017. Os achados mais recentes, publicados no periódico The Lancet, são dos primeiros 18 meses pós-vacinação. A investigação continua para conferir outros dados, como a duração da imunidade e segurança em longo prazo.

No registro submetido à avaliação da Anvisa, a fabricante indica que a fórmula poderá ser inoculada em pessoas entre 4 e 60 anos que tiveram ou não dengue. Esse é um detalhe importante. Vamos a ele.

A vacina que temos hoje tem uso limitado

Existe uma vacina contra a dengue aprovada no Brasil, a Dengvaxia, da Sanofi-Pasteur. Mas ela só está disponível na rede particular, e para quem já teve a doença. Ou seja, é preciso fazer um teste sorológico para verificar a presença de anticorpos (já quem nem sempre a infecção provoca sintomas) ou ter recebido a confirmação no passado.

Isso porque, em indivíduos sem contato prévio com o vírus, o imunizante pode provocar um quadro chamado de antibody-dependent-enhancement (ADE), algo como "amplificação da doença causada por anticorpos", em tradução livre. "Nessa situação, há o risco de desenvolver quadros mais graves de dengue ao ser infectado depois de receber a dose", conta o pediatra José Geraldo Leite Ribeiro, vice-presidente da Regional de Minas Gerais da Sociedade Brasileira de Imunizações (SBIm-MG).

Por causa dessa restrição, o imunizante da Sanofi-Pasteur acabou não deslanchando e ficou restrita a um número pequeno de pessoas.

Já a Takeda afirma que a TAK-003 não desperta tal mecanismo. "Os 20 mil voluntários da fase 3 foram testados antes de começar a pesquisa e, entre eles, 27,6% eram soronegativos (não tinham anticorpos contra o vírus)", comenta Abner Lobão, diretor executivo de Medical Affairs da Takeda no Brasil.

Com três anos de acompanhamento, os pesquisadores não detectaram nenhuma ocorrência do tipo. No caso da Dengvaxia, foram cerca de cinco anos até flagrar a relação. "O desafio da Anvisa será interpretar se o período desse estudo é o suficiente para demonstrar que não há o risco", comenta Leite.

Continua após a publicidade

A Takeda informou à Anvisa que a vacina pode ser tomada por todos. "Estamos tranquilos em afirmar que ela não causa o problema", completa Lobão.

Como ela funciona

A TAK-003 é uma vacina quimérica de vírus vivo atenuado. Traduzindo: é feita com pedacinhos de vírus modificados para ficarem mais fraquinhos, incapazes de provocar sintomas importantes. Diferentemente da Dengvaxia, que usa uma versão do agente por trás da febre amarela, o produto tem como base o sorotipo 2 do próprio causador da dengue. "Por meio da engenharia genética, ele passa a conter em sua superfície partes dos outros sorotipos, 1, 3 e 4", conta Lobão.

A vacina deve ser tomada em duas doses, com três meses de intervalo, e ainda não se sabe se precisará ser reaplicada de tempos em tempos. "Os dados atuais indicam que a imunidade se mantém, mas precisamos acompanhar os voluntários por mais tempo", completa o porta-voz da fabricante.

Quando deve chegar

A Anvisa tem 60 dias para decidir sobre o registro. O plano é que, uma vez aprovada, ela seja negociada com o governo e incorporada ao Programa Nacional de Imunizações (PNI).

Se realmente a vacina da Takeda puder ser aplicada na população como um todo, independentemente de uma infecção prévia por dengue, o potencial benefício para a sociedade é grande. Apesar de pouco falada no momento, a dengue segue fazendo estragos durante a pandemia de Covid-19. "Os casos dessa infecção na América Latina dobram a cada dez anos, o que mostra que nossas medidas de controle de vetores não estão funcionando", pontua o pediatra da SBIm.

Em 2020, foram registrados quase um milhão de casos prováveis de dengue no Brasil, segundo o Ministério da Saúde, dado que pode estar subestimado pela onipresença do coronavírus na rede de atendimento.

Existe ainda uma vacina sendo produzida pelo Instituto Butantan. Ela é de dose única, também tem ação contra os quatro sorotipos e foi testada em 17 mil voluntários na fase 3, mas os resultados da fase final ainda não foram divulgados.

Continua após a publicidade

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A nova vacina contra a dengue que pode ser aprovada no Brasil

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A farmacêutica Takeda solicitou à Agência Nacional de Vigilância Sanitária (Anvisa) o registro de uma nova vacina contra a . A TAK-003 é feita com uma versão modificada do vírus vivo atenuado e protege contra os quatro sorotipos da doença. No estudo de fase 3, a vacina demonstrou eficácia geral de 80,2% na prevenção de casos confirmados de dengue.

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Problemática relacionada à falta de autonomia brasileira em relação à produção de #vacinas

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Problemática relacionada à falta de autonomia brasileira em relação à produção de #vacinas

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Olá, pessoal. Hoje trouxe um texto super importante que discute sobre os problemas relacionados com a falta de protagonismo do Brasil em produzir suas próprias vacinas. Espero que gostem :D

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SBMT - Sociedade Brasileira de Medicina Tropical

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Publicação: 9 de março de 2021

País não tem parque de tecnologia que possa suprir a carência que possui

Em meio à pandemia do novo coronavírus a biotecnologia se mostrou como ferramenta essencial para enfrentar a COVID-19. Graças a ela e aos esforços dos pesquisadores foram necessários apenas 42 dias para que uma vacina baseada em biotecnologia moderna chegasse à primeira fase clínica. Com o auxílio dessa tecnologia, não apenas a vacina mRNA-1273 foi desenvolvida, mas também outras que utilizam DNA ou proteína recombinante. O potencial de aplicação da biotecnologia na área da saúde é muito amplo e, além de ajudar a detectar doenças em pessoas, animais e plantações, seus avanços têm contribuído para o desenvolvimento de formulações mais seguras e eficazes.

No Brasil, desde a década de 1970, houve grande investimento na formação de pesquisadores qualificados na área de biotecnologia. Entretanto, somente em 2005, foi regulamentada a Lei de Inovação Tecnológica, que estabelece medidas de incentivo à inovação e à pesquisa científica e tecnológica no ambiente produtivo, visando ao alcance da autonomia tecnológica e ao desenvolvimento industrial do País.

Contudo, o Brasil entrou atrasado na corrida pelo domínio do conhecimento dos processos biotecnológicos e sua aplicação na produção industrial. O diretor da Fundação Oswaldo Cruz (Fiocruz), o pesquisador especialista em saúde pública na área de biotecnologia, Dr. Rodrigo Stabeli, lembra que a carência da tecnologia para essa área no Brasil é estrutural. "O advento de tecnologias para produção de medicamentos, principalmente os bioinsumos, faz com tenhamos total dependência de importação. Mesmo que as empresas estejam em solo brasileiro, elas precisam utilizar produtos ativos que são importados, porque não temos um parque de tecnologia que possa suprir a carência tecnológica que o Brasil possui, e isso é estrutural", ressalta. Para melhor entender o gap ao comparamos o Brasil a outros países que investiram nessa tecnologia, o pesquisador cita o primeiro centro de prototipagem para bioinsumos que foi inaugurado América Latina há apenas três anos. Para ele, a biotecnologia não recebeu o mesmo incentivo que o desenvolvimento científico teve quando da criação da Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp) e do Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), por exemplo. O Dr. Stabeli esclarece que houve investimento na ciência e na tecnologia, mas investimento em tecnologia industrial é insipiente.

Investimentos em biotecnologia podem melhorar a ciência no Brasil. A Dra. Luciana Cezar de Cerqueira, que tem ampla experiência na área de biotecnologia molecular, com ênfase no desenvolvimento de vacinas, explica que a ciência envolve a pesquisa básica e a pesquisa aplicada, este último contém a biotecnologia, que ajuda a traduzir o conhecimento para produtos de interesse da população. Para a pesquisadora, a aquisição da competência em biotecnologia é um processo contínuo pela dinâmica da área, então o investimento precisa ser contínuo. "Não se pode adquirir esta competência de uma hora para outra, se ela não está estabelecida o investimento não resolve", acrescenta.

A professora do Departamento de Biologia Celular e Genética da Universidade Federal do Rio Grande do Norte (UFRN) Lucymara Fassarella, que também é coordenadora-geral da Rede Nordeste de Biotecnologia (Renorbio), atenta que o Brasil conta uma base acadêmica forte, excelentes pesquisadores, programas de pós-graduação bem estabelecidos, ou seja, em termos de recursos humanos o País tem uma massa crítica razoável. "Temos boa produção científica, somos o principal produtor de conhecimento científico na América Latina, embora ainda estejamos distantes de países como Estados Unidos, alguns países da Europa ou asiáticos, mas vejo que a maior deficiência se dá entre a academia e o setor privado", frisa.

Na avaliação da coordenadora-geral da Renorbio, faltam instrumentos de interlocução, estratégias de aproximação, para que as demandas do setor privado cheguem às universidades de forma que ele também possa participar do desenvolvimento de novos produtos e insumos. "Mas também falta uma visão do setor privado quanto a importância do investimento em pesquisa, que começa pela pesquisa básica. A iniciativa privada aporta poucos recursos ainda para o desenvolvimento base das pesquisas", lamenta a Dra. Fassarella. A professora recorda a diferença de investimento em Ciência e Tecnologia praticada no Brasil ao mencionar que estamos muito aquém, em termos de Produto Interno Bruto (PIB), de países como Coreia, China, Estados Unidos. "Isso sem dúvida é uma das principais razões de não sermos tão competitivos. O investimento é fundamental e temos vivido um período de diminuição de investimentos, o que isso é extremamente prejudicial para as instituições de Pesquisas brasileiras. Muitos pesquisadores estão sem recursos para trabalhar devido ao contingenciamento que tem ocorrido", conclui.
Brasil sem autonomia
As empresas que mais cresceram nos últimos dez anos foram as que investiram em tecnologia do DNA recombinante e bioinsumos para produção de anticorpos. Infelizmente não tivemos esse investimento no Brasil. De acordo com o Dr. Stabeli, temos ótimos cientistas que conseguem fazer manipulações na bancada, mas não temos equipamentos suficientes para transformar em produção, o que se reflete também nas vacinas. E neste ponto o pesquisador é categórico ao afirmar que recursos em vacinas são investimentos e não gastos. Um país que pensa na tecnologia em saúde é um país que busca o bem-estar social dos seus cidadãos e isso é investimento, não é gasto. Para ele, uma indústria brasileira forte, com tecnologia suficiente na saúde, vai trazer também o enriquecimento do país. "Se quisermos ter uma nação soberana e desenvolvida, precisamos investir em tecnologias que façam com que as nossas pesquisas saiam da bancada e cheguem até o setor industrial", enfatiza.

A Dra. Fassarella admite os gargalos existentes no desenvolvimento de medicamentos, de pesquisas para novas drogas e a grande dependência de insumos que muitas vezes são importados. Segundo ela, esse problema não se restringe somente à produção de vacina, mas para todos que trabalham com biologia molecular ou biotecnologia. A professora reforça que a falta de produção de insumos no Brasil faz com que as pesquisas fiquem dependentes de outros centros produtores de reagentes para biologia molecular. "Temos institutos como o Butantã e a Fiocruz com uma larga tradição na produção de vacinas, ou seja, capacidade técnica e de produção existe no País", diz.

Para se ter uma ideia, o Brasil é tão dependente da produção tecnológica de vacinas ou de anticorpos monoclonais que precisa muitas vezes comprar água em nível injetável. Noventa por cento do que é usado da tecnologia em medicina, hoje é importada, ou seja, é um déficit na balança comercial de 20 bilhões de dólares. Para o Dr. Stabeli, falta olhar a saúde como um complexo econômico e industrial. O complexo econômico industrial da saúde é uma das indústrias mais rentáveis do mundo. "Rentável no sentido de desenvolvimento de uma nação", acrescenta. E a pandemia mostrou essa importância para o mundo. Países que possuem tecnologias conseguiram dar uma resposta tanto no envase quanto na produção de vacinas e estão reduzindo o número de internações e mortes por COVID-19. Isso mostra o quão importante é termos tecnologia de saúde à disposição.

A Dra. Cerqueira Leite, que já foi vice-diretora da Fundação Butantã, diretora do Centro de Biotecnologia e diretora do laboratório de desenvolvimento de vacinas do Instituto, reconhece que o Brasil possui alta competência estabelecida em ciência básica e algumas fases do desenvolvimento de vacinas, como a fase de ensaios clínicos e de produção de alguns imunobiológicos. Entretanto, existe um gap nas fases de desenvolvimento envolvendo a biotecnologia, onde a competência para realizar as pesquisas necessárias ao escalonamento dos processos e obtenção de produtos com o controle de qualidade necessário para iniciar os ensaios clínicos é ainda incipiente. Ainda de acordo com a Dra. Cerqueira Leite, a biotecnologia no Brasil é restrita e certamente não suficiente para dar conta da pesquisa básica e aplicada realizada. "Muitas invenções se perdem porque não tem como seguir para as próximas etapas. O Brasil tem alguma competência em biotecnologia, mas o investimento necessário nesta área é maior do que nas áreas básicas. As fases de pouco investimento significam a perda da competência estabelecida e do investimento anterior", destaca ao dizer que o processo de desenvolvimento de tecnologia envolve um sem número de competências, algumas das quais estão faltando no Brasil.

O Brasil atualmente não tem uma política clara em setores estratégicos. No passado o Plano Nacional de Autossuficiência em Imunobiológicos impulsionou toda a área de biotecnologia e produção de medicamentos, incluindo a área de desenvolvimento de vacinas. "Mas atualmente todo o investimento na área de pesquisa e desenvolvimento foi reduzido. Isso vai na contramão da maioria dos países, que já perceberam que sem um setor de inovação forte não se sustenta uma economia, aponta a pesquisadora. Os países que estão conseguindo produzir as vacinas, inclusive dos países em desenvolvimento do BRICS, China, India e Russia, são aqueles que tem uma política de investimento nestes setores estratégicos, inclusive na Biotecnologia.
Biotecnologia em Saúde
Com inauguração prevista para 2023, o Complexo Industrial de Biotecnologia em Saúde do Instituto de Tecnologia em Imunobiológicos (Bio-Manguinhos) será o maior centro de fabricação de produtos biológicos da América Latina e um dos mais modernos do mundo. O local terá capacidade de produção de 120 milhões de frascos de vacinas e biofármacos por ano. Ele será responsável por toda produção de vacinas da Fiocruz, inclusive de COVID-19. As vacinas contra meningite, hepatite e tríplice bacteriana, que atualmente são importadas, também serão produzidas no complexo.

Atualmente o Brasil possui 574 empresas de biotecnologia, entre startups e maduras, nacionais e multinacionais, de acordo com o Mapa Biotec, divulgado pela plataforma aberta Profissão Biotec. Os dados revelam a desproporcional concentração de centros de pesquisa, base para a implantação das empresas de biotecnologia, em relação as regiões: São 381 no Sudeste; 113 no Sul; 45 no Centro-Oeste; 27 no Nordeste; 8 no Norte. As empresas estabelecidas vão desde a área ambiental à bioenergia, de insumos à saúde animal, além dos amplos setores da agricultura e indústria de alimentos. O setor de atuação "Saúde Humana e Bem Estar", por exemplo, inclui empresas que desenvolvem tecnologias, produzem e comercializam medicamentos biológicos, kits de diagnósticos, proteínas recombinantes, próteses, dispositivos e equipamentos médicos especializados, terapias celulares, curativos e peles artificiais e/ou vacinas para tratar humanos. Laboratórios de análise que tenham técnicas moleculares são contemplados, além de empresas com Pesquisa e Desenvolvimento na área, como identificação de novas moléculas e fármacos, validação de novos medicamentos (ensaios pré-clínicos e clínicos). São contempladas também as empresas da área cosmética ou higiene pessoal que obtém/modificam moléculas potenciais provenientes de bioprocessos através da utilização de microrganismos vivos ou parte deles e que possuem centros de pesquisa na área de Biotecnologia.

A biotecnologia está extremamente presente no desenvolvimento tanto de instrumentos para diagnóstico, prognóstico e muitas vezes até tratamento de doenças. É uma técnica revolucionária, uma ferramenta poderosa que possibilitou descobertas tecnológicas em várias áreas industriais e em setores da ciência com melhorias e inovações. Um dos impactos causados pela revolução biotecnológica moderna representou uma mudança significativa na forma como as vacinas modernas são desenvolvidas. Além disso, as pesquisas do uso da biotecnologia em diversas áreas, desde a produção de vacinas até medicamentos com menos efeitos colaterais podem proporcionar uma medicina mais personalizada e uma atuação mais eficaz na prevenção de doenças.

A pandemia de COVID-19 que levou a corrida das indústrias farmacêuticas para novas descobertas, pesquisas clínicas, medicamentos e serviços, evidenciou que o Brasil precisa expandir o setor de biotecnologia, pois sem autonomia, virou refém de outros países. Sem investimento na ciência e na tecnologia não vamos reduzir a desigualdade. Ela só vai diminuir quando entendermos que os pilares para o desenvolvimento de uma nação se baseiam na educação, na ciência e na tecnologia. O país que não investir neles está fadado a ser colonizado por aqueles que possuem a tecnologia. É o que vemos no Brasil até hoje: antes trocávamos nossas frutas, nosso ouro, por espelho. Hoje trocamos nossa soja por vacinas. E isso sai muito caro para a nação brasileira.

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Sem autonomia em biotecnologia, Brasil vira refém para aquisição de vacinas

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Publicação: 9 de março de 2021 País não tem parque de tecnologia que possa suprir a carência que possui Em meio à pandemia do novo coronavírus a biotecnologia se mostrou como ferramenta essencial para enfrentar a COVID-19. Graças a ela e aos esforços dos pesquisadores foram necessários apenas 42 dias para que uma vacina baseada em biotecnologia moderna chegasse à primeira fase clínica.

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O artigo em questão desenvolvido pela World Health Organization resume para leigos no que consiste as vacinas, como elas são produzidas, assim como ocorre sua distribuição.

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This article is part of a series of explainers on vaccine development and distribution. Learn more about vaccines - from how they work and how they're made to ensuring safety and equitable access - in WHO's Vaccines Explained series.
What are the ingredients in a vaccine?

Vaccines contain tiny fragments of the disease-causing organism or the blueprints for making the tiny fragments. They also contain other ingredients to keep the vaccine safe and effective. These latter ingredients are included in most vaccines and have been used for decades in billions of doses of vaccine.

Each vaccine component serves a specific purpose, and each ingredient is tested in the manufacturing process. All ingredients are tested for safety.
Antigen
All vaccines contain an active component (the antigen) which generates an immune response, or the blueprint for making the active component. The antigen may be a small part of the disease-causing organism, like a protein or sugar, or it may be the whole organism in a weakened or inactive form.
Preservatives
Preservatives prevent the vaccine from becoming contaminated once the vial has been opened, if it will be used for vaccinating more than one person. Some vaccines don't have preservatives because they are stored in one-dose vials and are discarded after the single dose is administered. The most commonly used preservative is 2-phenoxyethanol. It has been used for many years in a number of vaccines, is used in a range of baby care products and is safe for use in vaccines, as it has little toxicity in humans.
Stabilizers
Stabilizers prevent chemical reactions from occurring within the vaccine and keep the vaccine components from sticking to the vaccine vial.

Stabilizers can be sugars (lactose, sucrose), amino acids (glycine), gelatin, and proteins (recombinant human albumin, derived from yeast).
Surfactants
Surfactants keep all the ingredients in the vaccine blended together. They prevent settling and clumping of elements that are in the liquid form of the vaccine. They are also often used in foods like ice cream.
Residuals
Residuals are tiny amounts of various substances used during manufacturing or production of vaccines that are not active ingredients in the completed vaccine. Substances will vary depending on the manufacturing process used and may include egg proteins, yeast or antibiotics. Residual traces of these substances which may be present in a vaccine are in such small quantities that they need to be measured as parts per million or parts per billion.
Diluent
A diluent is a liquid used to dilute a vaccine to the correct concentration immediately prior to use. The most commonly used diluent is sterile water.
Adjuvant
Some vaccines also contain adjuvants. An adjuvant improves the immune response to the vaccine, sometimes by keeping the vaccine at the injection site for a little longer or by stimulating local immune cells.

The adjuvant may be a tiny amount of aluminium salts (like aluminium phosphate, aluminium hydroxide or potassium aluminium sulphate). Aluminium has been shown not to cause any long-term health problems, and humans ingest aluminium regularly through eating and drinking.

How are vaccines developed?

Most vaccines have been in use for decades, with millions of people receiving them safely every year. As with all medicines, every vaccine must go through extensive and rigorous testing to ensure it is safe before it can be introduced in a country's vaccine programme.

Each vaccine under development must first undergo screenings and evaluations to determine which antigen should be used to invoke an immune response. This preclinical phase is done without testing on humans. An experimental vaccine is first tested in animals to evaluate its safety and potential to prevent disease.

If the vaccine triggers an immune response, it is then tested in human clinical trials in three phases.
Phase 1
The vaccine is given to a small number of volunteers to assess its safety, confirm it generates an immune response, and determine the right dosage. Generally in this phase vaccines are tested in young, healthy adult volunteers.
Phase 2
The vaccine is then given to several hundred volunteers to further assess its safety and ability to generate an immune response. Participants in this phase have the same characteristics (such as age, sex) as the people for whom the vaccine is intended. There are usually multiple trials in this phase to evaluate various age groups and different formulations of the vaccine. A group that did not get the vaccine is usually included in phase as a comparator group to determine whether the changes in the vaccinated group are attributed to the vaccine, or have happened by chance.
Phase 3
The vaccine is next given to thousands of volunteers - and compared to a similar group of people who didn't get the vaccine, but received a comparator product - to determine if the vaccine is effective against the disease it is designed to protect against and to study its safety in a much larger group of people. Most of the time phase three trials are conducted across multiple countries and multiple sites within a country to assure the findings of the vaccine performance apply to many different populations.

During phase two and phase three trials, the volunteers and the scientists conducting the study are shielded from knowing which volunteers had received the vaccine being tested or the comparator product. This is called "blinding" and is necessary to assure that neither the volunteers nor the scientists are influenced in their assessment of safety or effectiveness by knowing who got which product. After the trial is over and all the results are finalized, the volunteers and the trial scientists are informed who received the vaccine and who received the comparator.

When the results of all these clinical trials are available, a series of steps is required, including reviews of efficacy and safety for regulatory and public health policy approvals. Officials in each country closely review the study data and decide whether to authorize the vaccine for use. A vaccine must be proven to be safe and effective across a broad population before it will be approved and introduced into a national immunization programme. The bar for vaccine safety and efficacy is extremely high, recognizing that vaccines are given to people who are otherwise healthy and specifically free from the illness.

Further monitoring takes place in an ongoing way after the vaccine is introduced. There are systems to monitor the safety and effectiveness of all vaccines. This enables scientists to keep track of vaccine impact and safety even as they are used in a large number of people, over a long time frame. These data are used to adjust the policies for vaccine use to optimize their impact, and they also allow the vaccine to be safely tracked throughout its use.
Once a vaccine is in use, it must be continuously monitored to make sure it continues to be safe.

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This article is part of a series of explainers on vaccine development and distribution. Learn more about vaccines - from how they work and how they're made to ensuring safety and equitable access - in WHO's Vaccines Explained series. What are the ingredients in a vaccine?

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Como a tecnologia aplicada à vacina contra COVID-19 auxilia no desenvolvimento de vacinas futuras para diversas doenças #vacinas

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Como a tecnologia aplicada à vacina contra COVID-19 auxilia no desenvolvimento de vacinas futuras para diversas doenças #vacinas

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"Com esse tipo de vacina, a maior parte do trabalho já foi feito, o 'bolo' já foi assado previamente, só precisa ser 'decorado' para atingir seu objetivo."

Com essa fala da criadora do imunizante de Oxford, o "bolo" seria a plataforma e a "decoração" seria qualquer material genético necessário para treinar o sistema imunológico a combatê-lo.

Entre os 11 vírus potencialmente pandêmicos estão: Mers, Lassa, vírus causador da Febre Hemorrágica, Nipah, Zika, Ebola, vírus causador da Febre do Vale, Chicungunya, vírus causador da Dengue, Hantavírus e Marburg. E 2 doenças bacterianas: Peste e Febre Q.

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As 13 doenças prioritárias para vacinas, segundo criadora do imunizante de Oxford contra covid-19 - BBC News Brasil

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Dengue, chikungunya e zika estão na lista de prioridades da professora Sarah Gilbert. Financiamento para pesquisa ainda é desafio quando se trata de vacinas para doenças que atingem mais países pobres.

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Vacina da fabricante Janssen contra a zika apresenta 🤬 preliminares promissores #vacinas

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Vacina da fabricante Janssen contra a zika apresenta 🤬 preliminares promissores #vacinas

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Boa noite a todos. Trago aqui uma notícia um pouco antiga, mas que ainda vale a pena ser revisitada. A fabricante Janssen, mesma da vacina contra COVID-19 de dose única, está desenvolvendo uma vacina contra a Zika, doença viral típica do Brasil, transmitida pelo mosquito Aedes Aegypti, e as aplicações preliminares de duas doses mostraram-se promissoras. Vale a pena pesquisar mais, visto que essa notícia é meramente expositiva.

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A candidata a vacina contra o vírus da zika, desenvolvida pela empresa Janssen, demonstrou segurança e geração de uma resposta imunológica promissoras após a conclusão de um ensaio clínico de fase I, segundo um estudo publicado pela revista "Annals of Internal Medicine".

A incidência do vírus diminuiu desde o surto de 2015-2016, mas a propagação geográfica do mosquito Aedes aegypti para áreas onde a imunidade da população é baixa "representa um risco substancial para futuras epidemias", já não existe nenhuma vacina disponível.

Por isso, os pesquisadores acreditam que essa candidata a vacina, chamada Ad26.ZIKV.001, "justifica um maior desenvolvimento em caso de que a necessidade surja novamente".

Para a realização dos testes e análise da eficácia da vacina, cientistas do Centro Médico Janssen e do Beth Israel Deaconess atribuíram, aleatoriamente, 100 participantes saudáveis a um regime de uma ou duas doses da vacina e a um placebo.

Os resultados mostraram que duas doses eram seguras, causavam "reatogenicidade (possíveis reações adversas) entre leve e moderada, e induziam respostas persistentes de anticorpos neutralizantes".

Também foram observadas respostas de anticorpos até um ano após a vacinação em pelo menos 80% dos participantes em ambos os grupos de duas doses (alta e baixa), "indicando que uma dose baixa seria suficiente".

Uma única dose da vacina produziu "uma resposta de anticorpos neutralizante de pico inferior às estratégias de duas doses", mas mostrou anticorpos duradouros em um ano e, portanto, "pode ser um instrumento útil para evitar futuras epidemias de Zika".

O vírus da zika é transmitido por mosquitos ou sexualmente e pode causar doenças congênitas graves apor transmissão materno-fetal, como a microcefalia.

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Vacina contra a zika tem resultados promissores nos primeiros testes

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A candidata a vacina contra o vírus da zika, desenvolvida pela empresa Janssen, demonstrou segurança e geração de uma resposta imunológica promissoras após a conclusão de um ensaio clínico de fase I, segundo um estudo publicado pela revista "Annals of Internal Medicine".

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Evolução do negacionismo: "contra o uso de máscaras" aos " anti-vacinas" em meio a pandemia de COVID-19. #vacinas

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Evolução do negacionismo: "contra o uso de máscaras" aos " anti-vacinas" em meio a pandemia de COVID-19. #vacinas

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Oi gente. Achei esse artigo que tratou da repercussão nas mídias sociais dos discursos negacionistas contra o uso de máscaras e como este pode evoluir para manifestações anti-vacina. Achei bem interessante, pois passa pela importância da comunicação Academia x Sociedade, e pela divulgação da ciência como ato de resistência.

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Available online 28 October 2021

Highlights

*

This paper provides an overview of the key trends and themes of discussion concerning attitudes to and the adoption of two health measures to control COVID-19 in the UK and US.

*

Using social media data collected via Twitter, we explore how different public groups react when confronted with mandatory policies.

*

We find two constituencies have been brought together: pre-existing vaccine critical 'anti-vaccine' groups and newly formed oppositional COVID-19 groups.

*

The oppositional COVID-19 constituencies vary in composition and nature, but the central focus is a disagreement about the seriousness and threat of COVID-19 and public health measures to control COVID-19. What unites many disparate interests is an aversion to mandates.

Abstract

Protests starting in the summer of 2020, notedly in the US and UK, have brought together two constituencies: pre-existing anti-vaccine groups and newly formed oppositional COVID-19 groups. The oppositional COVID-19 groups vary in composition and nature, but the central focus is a disagreement about the seriousness and threat of COVID-19 and with the public health measures to control COVID-19. What unites many disparate interests is an aversion to mandates. The compulsion to undertake particular public health activities such as mask-wearing and vaccination is a complex topic of public attitudes and beliefs alongside public health goals and messaging. We aim to analyse social media discussions about facemask wearing and the adoption of potential vaccines for COVID-19.

Using media monitoring softwares Meltwater and Talkwalker, we analyse English-language tweets for one year from 1st June 2020 until 1st June 2021. We pay particular attention to connections in conversations between key topics of concern regarding masks and vaccines across social media networks. We track where ideas and activist behaviours towards both health interventions have originated, have similarities, and how they have changed over time.

Our aim is to provide an overview of the key trends and themes of discussion concerning attitudes to and adoption of health measures in the control of COVID-19 and how publics react when confronted with mandatory policies. We draw on an already extensive literature about mandatory vaccination policies to inform our assessment, from psychology and behavioural science to ethics, political theory, sociology, and public policy.

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"Any idea how fast 'It's just a mask!' can turn into 'It's just a vaccine!'": From mask mandates to vaccine mandates during the COVID-19 pandemic

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Available online 28 October 2021 * This paper provides an overview of the key trends and themes of discussion concerning attitudes to and the adoption of two health measures to control COVID-19 in the UK and US. * Using social media data collected via Twitter, we explore how different public groups react when confronted with mandatory policies.

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How Vaccines Work: The Complete History of Vaccines #vacinas

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How Vaccines Work: The Complete History of Vaccines #vacinas

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Olá, pessoal!

Hoje trago um vídeo curto, mas muito ilustrativo e didático sobre o histórico das vacinas e o princípio de funcionamento delas. Esse video é de 2015 e um dos tópicos mais interessantes abordados é a busca incessante por melhorias, como o desenvolvimento de vacinas mais eficientes e também vacinas mais baratas, para que possam chegar a todos. De 2015 pra cá, muitos avanços na ciência e tecnologia surgiram, e esses continuam sendo pontos muito buscados. Esse debate ganhou bastante força desde o início da pandemia de Covid-19 e com a corrida pelas vacinas.
O video é bem legal, vale a pena assistir!

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How Vaccines Work: The Complete History of Vaccines

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Documentário: A Corrida das Vacinas #vacinas

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Documentário: A Corrida das Vacinas #vacinas

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Oii galera! Trago uma indicação já para maratonar nesse final de semana, é o documentário “A corrida das vacinas” que fala em 5 episódios sobre a criação, em tempo recorde, de vacinas contra a Covid-19 na Índia, na Rússia, na China, nos EUA, na Europa e no Brasil. #vacinas

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Assistir A Corrida das Vacinas online no Globoplay

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Veja online A Corrida das Vacinas online no Globoplay

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Plataformas vacinais podem nos proteger contra novas pandemias

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Plataformas vacinais podem nos proteger contra novas pandemias

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Oi, pessoal!

Como a nós sabemos, a pandemia de Covid-19 nos permitiu ter acesso a vacinas com o menor tempo já visto na história. Isso ocorreu principalmente pela utilização de plataformas vacinais: tecnologias que podem ser utilizadas como base para a criação de diversas outras vacinas.

Hoje eu trouxe esse artigo que explica um pouco como o desenvolvimento dessas plataformas vacinais é importante e como elas podem nos preparar para futuras pandemias.

#vacinas

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How Vaccine Platforms Can Prepare Us for Future Pandemics

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The Covid-19 pandemic exposed the weaknesses in our defenses. Vaccine platforms will be a powerful tool to react faster to future pandemics.

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Brasileiros combinam técnicas de biotecnologia para vacina contra covid-19

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Brasileiros combinam técnicas de biotecnologia para vacina contra covid-19

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Entrevista com pesquisadores do Instituto Butantan do começo da pandemia que detalha as estratégias utilizadas para desenvolver a Coronavac #vacinas

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Pesquisadores do Instituto Butantan combinam diferentes técnicas de biotecnologia para vacina contra Covid-19 (Foto: Gerd Altmann/Pixabay)

Pesquisadores do Instituto Butantan vão combinar técnicas inovadoras de biotecnologia para formular uma nova vacina contra Covid-19. O objetivo é induzir no organismo, de modo mais efetivo, diferentes tipos de resposta imune contra o novo coronavírus (Sars-CoV-2).

A nova estratégia é inspirada em um mecanismo usado por certas bactérias para "despistar" nosso sistema imune: elas liberam pequenas esferas feitas com o material de suas membranas como iscas para desviar a defesa do organismo. Essas vesículas, denominadas membranas pelos pesquisadores, têm a propriedade de ativar intensamente o sistema imunológico e, por isso, atraem células e moléculas da defesa do organismo.

Os pesquisadores vão aproveitar esse artifício das vesículas de membrana e acoplar a elas proteínas de superfície do novo coronavírus. Criadas em laboratório, essas vesículas atrairiam a defesa imune contra as proteínas de superfície do Sars-CoV-2, induzindo uma memória a ser mobilizada no caso de uma eventual infecção. A formulação estimularia não só a produção de anticorpos, mas também de outras células ligadas ao sistema imune, como macrófagos e glóbulos brancos.

"Para essa abordagem, juntamos duas estratégias diferentes que já vínhamos utilizando no desenvolvimento de vacinas contra outras doenças. A nova técnica permite que as formulações contenham uma grande quantidade de um ou mais antígenos do vírus em uma plataforma fortemente adjuvante, induzindo uma resposta imune mais pronunciada", diz Luciana Cezar Cerqueira Leite, pesquisadora do Laboratório de Desenvolvimento de Vacinas do Instituto Butantan.

O estudo, apoiado pela FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo), integra uma plataforma de pesquisa que envolve o desenvolvimento de vacinas para coqueluche, pneumonia, tuberculose e esquistossomose, com base em técnicas desenvolvidas para a BCG recombinante (usada para prevenir formas graves de tuberculose em crianças). Recentemente, foi criada uma nova linha no projeto voltada ao desenvolvimento de uma vacina para a Covid-19.

"No mundo todo, e aqui no Brasil também, estão sendo testadas diferentes técnicas. Muitas delas têm como base o que já estava sendo desenvolvido para outros vírus, como o que causou o surto de Sars em 2001. Esperamos que funcionem, mas o fato é que ninguém sabe se vão realmente proteger. Neste momento de pandemia, não é demais tentar estratégias diferentes. A nossa abordagem vai demorar mais para sair, mas, se aquelas que estão sendo testadas não funcionarem, já temos os planos B, C ou D", diz a pesquisadora.

Muitas vacinas consistem em soluções com o patógeno morto ou atenuado. São as chamadas vacinas celulares que, ao serem injetadas no indivíduo, têm por objetivo desenvolver a resposta imune contra o microrganismo, como anticorpos específicos e outras células de defesa de modo seguro, sem sofrer as consequências da doença. Dessa forma o indivíduo fica imunizado, tendo uma "memória de combate" do próprio sistema imune contra um determinado patógeno.

"As vacinas celulares são formas simples, e com frequência eficazes, de se obter um imunizante, porém, essas abordagens nem sempre funcionam, principalmente para patógenos com grande variabilidade antigênica ou organismos mais complexos, com mecanismos de evasão do sistema imune mais sofisticados", diz a pesquisadora.
Estratégias
O grupo do Butantan propõe a combinação de duas estratégias para o desenvolvimento de uma vacina acelular. De um lado, tem-se as proteínas recombinantes de antígenos de superfície do novo coronavírus, que têm o papel de deflagrar a produção de anticorpos específicos contra o Sars-CoV-2. De outro lado, utiliza-se vesículas de membrana externa ( Outer membrane vesicles conhecidos como OMVs) como matriz suporte dos antígenos, para que a partícula mimetize o vírus.

"As vesículas de membrana externa podem modular a resposta imunológica, em geral, aumentando e melhorando a proteção. Muitas vacinas têm o hidróxido de alumínio como principal adjuvante. No nosso caso, usaremos as OMVs para uma apresentação do antígeno com forte poder adjuvante embutido, que garante uma resposta melhor", diz.

Para isso, a vacina em desenvolvimento no Butantan usará uma plataforma inovadora de apresentação de antígenos chamada Multiple antigen presenting system (MAPS), desenvolvida por um colaborador da Universidade Harvard (Estados Unidos) e usada em uma formulação experimental contra o pneumococo.

Basicamente, o complexo molecular é montado por um sistema de acoplamento semelhante ao usado para detecção na reação de ELISA (ensaio de imunoabsorção enzimática), muito usada em diagnósticos. Esse tipo de teste de laboratório é usado para detectar anticorpos contra um determinado patógeno e assim diagnosticar doenças. No processo desenvolvido em Harvard, um ou vários antígenos são ligados a polissacarídeos das cápsulas das bactérias, como se fossem peças de encaixar.

"É uma plataforma que permite a ligação não covalente de proteínas de forma muito eficiente, permitindo saturar a superfície da OMV com as proteínas do vírus, tornando-as bastante imunogênicas", disse Cerqueira Leite à Agência FAPESP.

A ideia de usar as OMVs partiu da observação de uma estratégia que determinadas bactérias gram-negativas adotam para escapar do sistema de defesa do hospedeiro. "Quando infectam organismos, as bactérias produzem essas vesículas a partir de sua própria membrana externa. O intuito é atrapalhar a resposta do sistema imunológico. Anticorpos e outras células relacionadas ao sistema imune ficam tentando matar as vesículas em vez de atacar as bactérias, que ficam livres para se multiplicar no organismo", diz.

Na nova formulação, a presença dessas vesículas extracelulares tem a função de estimular a resposta imunológica. "Elas são muito imunogênicas. Estudos recentes mostram que têm grande capacidade de ativar células dendríticas e macrófagos", diz.

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Brasileiros combinam técnicas de biotecnologia para vacina contra Covid-19

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Pesquisadores do Instituto Butantan vão combinar técnicas inovadoras de biotecnologia para formular uma nova vacina contra Covid-19. O objetivo é induzir no organismo, de modo mais efetivo, diferentes tipos de resposta imune contra o novo coronavírus (Sars-CoV-2).

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Vacinas: Da Saúde Pública ao Big Business                                                 #vacinas

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Vacinas: Da Saúde Pública ao Big Business                                                 #vacinas

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O panorama atual da indústria de vacinas brasileira e mundial é representado no trabalho demonstrado. São abordados aspectos relacionados aos efeitos da pandemia de COVID-19 sobre a indústria farmacêutica, comparações do setor de produção de vacinas entre os países componentes do grupo BRICS, bem como uma explanação sobre a importância do trabalho de instituições nacionais, a exemplo de Biomanguinhos e Fiocruz. Confira!

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Desenvolvimento de vacina contra covid-19 com cooperação local  #vacinas

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Desenvolvimento de vacina contra covid-19 com cooperação local  #vacinas

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Boa tarde, pessoal. A notícia do portal Fiocruz comenta a respeito do desenvolvimento da vacina HH-120-Defenser a partir da colaboração da UECE com a Fiocruz. Além disso, também conta com o apoio do governo estadual. A vacina ainda se encontra em fases de 🤬, mas apresenta resultados promissores. #vacinas

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Covid-19: Fiocruz assina acordo para desenvolver vacina no Ceará

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Acordo amplia a parceria da Fiocruz com o estado do Ceará nas áreas de pesquisa e ciência para a busca de soluções no campo da saúde

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Percepções e barreiras para a vacinação anual de influenza comparado à vacina da COVID-19 em uma população urbana subservida. #vacinas

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Percepções e barreiras para a vacinação anual de influenza comparado à vacina da COVID-19 em uma população urbana subservida. #vacinas

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Olá a todos. Este artigo trata de algo interessante. Os autores realizaram um estudo em Ohio, comparando a percepção da população menos favorecida em relação às vacinas da influenza e COVID-19, analisando qual é a importância que a população dá a essas vacinas e quais as limitações para ter o devido acesso a elas.

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Comparação entre a Vacinação da Influenza e COVID-19

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O Instituto Butantan e a Vacina Brasileira AntiCOVID #vacinas

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O Instituto Butantan e a Vacina Brasileira AntiCOVID #vacinas

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O texto explora o tema da suficiência brasileira em vacinas. Apresenta os caminhos praticados para a capacitação nas duas instituições brasileiras mais importantes no desenvolvimento e na produção de vacinas - o Instituto Butantan e o Instituto de Tecnologia em Imunobiológicos (Bio-Manguinhos). #vacinas

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O texto explora o tema da suficiência brasileira em vacinas. Apresenta os caminhos praticados para a capacitação nas duas instituições brasileiras mais importantes no desenvolvimento e na produção de vacinas - o Instituto Butantan e o Instituto de Tecnologia em Imunobiológicos (Bio-Manguinhos). Esses caminhos referem-se à compra pura e simples, à compra do produto com compromisso de transferência de tecnologia, às parcerias que incluem a realização de ensaios da fase 1 pelo comprador, o novo caminho anunciado pelo Instituto Butantan no qual a parceria prevê a realização de ensaio nas fases 1 e 2 e, finalmente, a invenção, desenvolvimento e produção locais de vacinas. Este último caminho é apenas mencionado como possibilidade. Apresenta dados sobre as chances de sucesso no desenvolvimento de vacinas e louva a iniciativa do Butantan nessa nova modalidade de parceria.

Palavras-chave:
Vacinas; Desenvolvimento tecnológico; Indústria; Saúde Pública

The text explores the theme of Brazilian sufficiency in vaccines. It presents the ways practiced in the two most important Brazilian institutions in the development and production of vaccines - the Butantan Institute and the Institute of Technology in Immunobiologicals (Bio-Manguinhos). These paths are the pure and simple purchase, the purchase of the product with technology transfer commitment, partnerships that include the fulfillment of phase 3 trials by the buyer, the new path announced by Instituto Butantan in which the partnership includes for the realization of trials in phases 1 and 2 and, finally, the invention, development and local vaccine production. The latter is only mentioned as a possibility currently not achieved. Finally, the text presents data on the chances of success in vaccine development.

Key words:
Vaccines; Technological development; Industry; Public Health

No Brasil, há cinco caminhos possíveis para uma vacina chegar ao Sistema Único de Saúde (SUS). Em qualquer um deles, o produto deverá ter um registro na Agência Nacional de Vigilância Sanitária (Anvisa) e ter sido incorporado pela Comissão Nacional de Incorporação de Tecnologias (Conitec/MS).

O primeiro caminho é comprar um produto acabado que já esteja sendo comercializado pela empresa que o inventou, desenvolveu e produziu. Neste caso, se trata de uma operação comercial comum, cuja eficácia se encerra com a chegada do produto nas quantidades contratadas e seu pagamento.

O segundo caminho é um produtor nacional qualificado comprar o produto acabado mediante um contrato que contenha cláusulas de compensação tecnológica, atualmente denominadas de 'encomenda tecnológica'. Este contrato habitualmente prevê uma primeira etapa de entrega do produto acabado e, em etapas seguintes, uma crescente apropriação pelo comprador de operações retrógradas de desenvolvimento e produção locais. Os contratos definem prazos, cronograma de entrega do produto acabado e de matérias primas, eventuais treinamentos de profissionais, mercados a serem explorados e royalties a serem pagos ao proprietário da tecnologia que, durante a transferência da tecnologia, devem ser somados ao preço pago pelas vacinas acabadas. Nas regras vigentes de regulação da propriedade intelectual, essa modalidade de operação, presente em vários contratos há muito assinados por Butantan e Bio-Manguinhos/Fiocruz, é denominada de 'licenciamento voluntário'. Uma alternativa a ele é o 'licenciamento compulsório', previsto desde 2001 no regramento da Organização Mundial do Comércio para situações de emergência ou crise sanitária. Até hoje não foi utilizado no terreno das vacinas e uma iniciativa patrocinada pela África do Sul e Índia em 2020 não conseguiu ir adiante por oposição dos países ricos, com a lamentável adesão do Brasil a esse grupo.

O terceiro caminho foi o utilizado pelo Instituto Butantan no acordo entre ele e a empresa chinesa Sinovac, para o desenvolvimento e produção da vacina Coronavac. Neste caso, diferentemente do caminho anterior, a tecnologia de produção - vírus inativado - é amplamente dominada pelo instituto, o que vem conferindo maior aderência aos prazos de fornecimento do produto ao SUS. E há uma particularidade relativa à realização do ensaio de fase 3: a Sinovac não elaborou um protocolo único para ser rigorosamente seguido por todos os países que estabeleceram acordos de compra de seu produto. Cada país, dentro de certos delineamentos gerais, conduziu o seu protocolo que, entre nós, foi realizado pelo próprio Butantan, e a determinação da eficácia da vacina foi estabelecida após a consolidação dos resultados dos distintos ensaios realizados em vários países.

O quarto caminho é o que orienta o debate atual. O Butantan reivindica ter chegado à formulação da primeira 'vacina brasileira' e isso tem gerado controvérsia, haja vista que um componente importante da vacina foi inventado, desenvolvido e patenteado nos Estados Unidos. Esse componente é um vírus modificado inócuo para humanos, mas capaz de expressar a proteína da espícula infectante do Sars-CoV-2 sem a capacidade de penetrar nas células humanas, mas com a capacidade de produzir anticorpos contra ela. Outros detalhes do contrato não são conhecidos. O que é original no anúncio do Butantan é que o acordo com os detentores da patente envolve a realização no Brasil das etapas iniciais da fase de estudos clínicos - fases 1 e 2 - que medem a imunogenicidade em humanos e a segurança da vacina. Em tempos "normais" habitualmente apenas a fase 3 dos estudos clínicos costumava ser terceirizada para o exterior por razões quase sempre relacionadas a economia de recursos.

O quinto caminho é a invenção e desenvolvimento completos no país, cuja discussão merece um texto exclusivo. Segundo a imprensa, são 16 projetos em variadas etapas preliminares de prova de conceito 1. Mas, adianto que se continuarmos com o encurtamento financeiro crônico atualmente muito agravado e a destruição institucional, no máximo tornaremos pontual um meritório esforço de nossa comunidade científica.

Em 2019, Lo e Siah ² 2 Lo A, Siah K. Estimation of clinical trial success rates and related parameters. Biostatistics 2019; 20(2):273-286. estimaram as chances de sucesso de 1.869 vacinas contra doenças infecciosas. Em resumo, 76,8% desse total passaram da fase 1 para 2; dentre as que passaram (1.235), 58,2% tiveram sucesso na fase 2 (42,1% das 1.869 iniciais); dentre as que entraram em fase 3 (609), 85,4% tiveram sucesso nessa última fase. As chances de sucesso agregadas foram de 33,4%. Em 26 de março de 2021, a atualização do panorama das vacinas contra o Sars-CoV-2 da Organização Mundial da Saúde (OMS) continha 83 vacinas desenvolvendo ensaios em humanos, sendo 63 nas fases 1 e 2 e 20 nas fases 3 e 43. Cabe aqui observar que a prontidão da comunidade científica internacional em desenvolver vacinas durante a pandemia, até agora, tem aumentado a "mortalidade" entre as candidatas. São 7,5% de sucesso até a fase 3 contra os 33,4% do trabalho já citado. Mas, é necessário considerar que essa corrida ainda não chegou ao seu final.

Em face dos números de Lo e Siah, o anúncio do Butantan suscita três comentários. O primeiro é que os riscos de insucesso não são desprezíveis; 57,9% de acordo com os aqueles números (100 - 42,1). O segundo comentário é a evidência da confiança depositada pelos detentores da patente na competência técnica do instituto. Difícil acreditar que se assim não fosse, essa descentralização do desenvolvimento em etapa precoce da fase clínica teria sido realizada. O terceiro é que o Butantan, como na parceria com a Sinovac, mais uma vez aposta numa rota tecnológica segura. Caso a candidata passe nas três fases de ensaios clínicos e entre em produção, não haverá maiores dificuldades, pois é por esta rota que a vacina contra a gripe sazonal já é lá produzida (inoculação em ovos seguida de inativação do vírus).

A vacina candidata anunciada pelo Butantan aparece na base de dados da OMS tendo como desenvolvedores Mahidol University/GPO (Tailândia) e Icahn School of Medicine at Mount Sinai e o registro do ensaio que aparece no ClinicalTrials.gov foi atualizado pela última vez em 16 de março de 2021. É bem possível que haja nova atualização e, caso a parceria com o Butantan seja realizada nos moldes da que foi feita com a Coronavac (cada parceiro conduz seu próprio protocolo), talvez seja necessário um novo registro de ensaio.

O debate sobre se essa é ou não uma 'vacina brasileira', não pode ser respondido de modo binário - é ou não é. Do ponto de vista da propriedade intelectual, não é. Do ponto de vista de um avanço na modalidade das parcerias entre os laboratórios nacionais e estrangeiros, sem dúvida é um passo adiante. E do ponto de vista do Brasil arriscar possuir mais uma vacina de qualidade contra o Sars-CoV-2, sem dúvida é um fato extremamente positivo. E, imaginemos se, mais adiante, dada a aposta tecnológica do Butantan em caminhar sobre rotas que já domina, possa chegar a uma vacina com cinco antígenos. Os três da influenza e dois de variantes da Sars-CoV- 2.

Parabéns ao Butantan!

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O Instituto Butantan e a Vacina Brasileira AntiCOVID

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O texto explora o tema da suficiência brasileira em vacinas. Apresenta os caminhos praticados para a capacitação nas duas instituições brasileiras mais importantes no desenvolvimento e na produção de vacinas - o Instituto Butantan e o Instituto de Tecnologia em Imunobiológicos (Bio-Manguinhos).

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Desenvolvimento de vacinas para doenças infecciosas emergentes #vacinas

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Desenvolvimento de vacinas para doenças infecciosas emergentes #vacinas

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Olá! Trago essa revisão de 2021, que fala um pouco sobre estratégias de produção de vacinas, bem como sobre as plataformas utilizadas, não só na pandemia do COVID-19, mas também relembrando os caminhos utilizados para doenças infecciosas anteriores e como cada uma dessas situações podem oferecer lições valiosas como de segurança e vigilância de variantes, dois pontos críticos.

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Vacina contra o câncer usando a tecnologia de mRNA #vacinas

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Vacina contra o câncer usando a tecnologia de mRNA #vacinas

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Nessa noticia é falado sobre o inicio da segunda fase de 🤬 da vacina contra o câncer usando a mesma tecnologia utilizada na vacina contra a COVID-19. A empresa responsável pelo processo de desenvolvimento dessa vacina é a BioNTech, mas a Moderna também vem realizando pesquisas para a criação de uma vacina semelhante.

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Daniel Schultz, Monica Matsumoto, Shridhar Jayanthi, Guilherme Pimentel , Luiz Gustavo Martins e Cristina Schultz

Daniel Schultz é cientista, professor de microbiologia e membro do núcleo de ciências computacionais em Dartmouth (EUA). Estuda a dinâmica dos processos celulares, com foco na evolução de bactérias resistentes a antibióticos. É formado em engenharia pelo ITA, doutor em química pela Universidade da Califórnia San Diego e pós-doutorado em biologia sistêmica em Harvard. Possui trabalhos de alto impacto publicados em várias áreas, da física teórica à biologia experimental, e busca integrar essas várias áreas do conhecimento para desvendar os detalhes de como funciona a vida ao nível microscópico.

Monica Matsumoto

Monica Matsumoto é cientista e professora de Engenharia Biomédica no ITA. Curiosa, tem interesse em áreas multidisciplinares e procura conectar pesquisadores em diferentes campos do conhecimento. É formada em engenharia pelo ITA, doutora em ciências pela USP e trabalhou em diferentes instituições como InCor/HCFMUSP, UPenn e EyeNetra.

Shridhar Jayanthi

Shridhar Jayanthi é agente de patentes com registro no escritório de patentes norte-americano (USPTO). Tem doutorado em engenharia elétrica pela Universidade de Michigan (EUA) e diploma de engenheiro de computação pelo ITA. Atualmente, trabalha com empresas de alta tecnologia para facilitar obtenção de patentes e, nas (poucas) horas vagas, é estudante de problemas na intersecção entre direito, tecnologia e sociedade. Antes disso, teve uma vida acadêmica com passagens pela Rice, MIT, Michigan, Pennsylvania e no InCor/USP, e trabalhou com pesquisa em áreas diversas da matemática, computação e biologia sintética.

Guilherme Pimentel

Guilherme Pimentel é pesquisador no instituto de física da Universidade de Amsterdã na Holanda, onde trabalha com novas teorias para explicar a expansão acelerada do Universo. Possui graduação em engenharia eletrônica, mestrado em física pelo ITA (Instituto Tecnológico de Aeronáutica) e doutorado em física na Universidade de Princeton. Sua pesquisa é focada em cosmologia e física de partículas.

Luiz Gustavo Martins

Luiz Gustavo Martins é engenheiro químico, mestrado em física pela Universidade Federal de Minas Gerais (UFMG). Atualmente é doutorando no MIT (Massachusetts Institute of Technology), na área de física do estado sólido experimental, onde trabalha espectroscopia óptica em materiais bidimensionais (com poucos átomos de espessura) e física de altas pressões.

Cristina Schultz

Cristina Schultz é oceanógrafa formada pela USP (Universidade de São Paulo), com mestrado em meteorologia pelo INPE (Instituto Nacional de Pesquisas Espaciais) e doutorado em oceanografia química pelo WHOI (Woods Hole Oceanographic Institution) e o MIT (Massachusetts Institute of Technology). Atualmente é cientista visitante na Universidade de Princeton, no NOAA (National Oceanic and Atmospheric Administration) e no Geophysical Fluid Dynamics Laboratory (Laboratório de Dinâmica de Fluidos Geofísicos). Sua pesquisa combina o uso de dados coletados em cruzeiros oceanográficos, dados de satélite e modelos climáticos para entender as consequências das mudanças climáticas na química do oceano e no ecossistema marinho.

Daniel Schultz

24/10/2021 04h00

Logo antes da pandemia, o amadurecimento simultâneo de várias tecnologias vinham causando excitação no universo da biotecnologia. Ainda um pouco distante do olhar do grande público, a promessa era de revolução na medicina num curto prazo.

Depois de muito quebrar a cabeça, cientistas vinham conseguindo: (1) levar material genético para dentro das nossas células, (2) usar esse material genético para expressar qualquer proteína e (3) usar esse mecanismo para cooptar nosso sistema imunológico para atacar qualquer alvo de nossa escolha. Afinal, temos dentro de nós um verdadeiro exército na escala celular, pronto para atacar qualquer atividade suspeita. Basta um pouco de treinamento.

Algumas empresas de biotecnologia já vinham se destacando nesse campo, e apesar de ainda não terem produtos no mercado, já vinham crescendo com os resultados promissores.

Despontando entre elas, Moderna e BioNTech, à época ainda desconhecidas pelo público geral. Porém, essas empresas vinham focando em terapias contra o câncer, uma área mais crítica na época, e alguns produtos já vinham em fase de testes.

Com a pandemia em 2020, esse foco mudou.

Como a tecnologia já estava desenvolvida, era fácil utilizá-la para novos fins. Essas empresas se aproveitaram de uma década de pesquisas sobre a SARS, uma doença muito próxima da covid, e desenvolveram as novas vacinas em tempo recorde.

Agora, grandes e famosas após a pandemia, estão diversificando o leque de aplicações, com resultados muito animadores para a luta contra o câncer.

Tratamentos personalizados contra o câncer

Nesse último mês, a BioNTech entrou na segunda fase de testes de sua nova "vacina" contra o câncer, a BNT122 (apesar de utilizar tecnologia semelhante à vacina da covid, esse tratamento não é para prevenir, mas sim para curar o câncer).

Nessa fase, 200 pacientes de câncer colorretal de alto risco receberão a vacina, depois de terem passado sem sucesso pelas cirurgias e quimioterapias normalmente utilizadas.

A Moderna também está desenvolvendo tratamentos semelhantes. Porém, ao contrário da vacina da covid, esses tratamentos são personalizados, com coquetéis desenvolvidos separadamente para cada paciente.

Um fator que sempre complicou a busca pela cura do câncer é justamente o fato de que cada câncer é diferente.

Células cancerígenas estão sempre se multiplicando fora de controle e adquirindo novas mutações, o que causa cada câncer a desenvolver características diferentes.

Com a popularização do sequenciamento de DNA, hoje em dia podemos sequenciar amostras desses tumores e obter a lista de mutações de cada paciente. Essa lista é justamente o que diferencia as células cancerígenas das células sadias do paciente. Resta ensinar o sistema imunológico a reconhecer essas diferenças.

Para isso, os cientistas utilizam métodos computacionais para identificar dezenas de proteínas mutantes produzidas unicamente pelas células cancerígenas, que podem ser utilizadas para se treinar o sistema imunológico a atacar os tumores.

Depois é só gerar o mRNA (RNA mensageiro) correspondente a essas proteínas e envolvê-lo numa nanopartícula lipídica, da mesma forma que é feito com a vacina da covid.

Esse tratamento vem operando milagres, mas ainda é muito custoso devido à necessidade de desenvolver um coquetel diferente para cada paciente.

Para se ter uma ideia, a fábrica da Moderna atribui uma cor para cada paciente durante os testes, e divide o laboratório em áreas com equipamentos, materiais e vestimentas nessas cores para que não haja contaminação entre as amostras.

Felizmente, a expectativa é que o custo baixe bastante no futuro, com a possível adoção em maior escala e a competição entre várias empresas.

Tratamentos mais acessíveis

Ao mesmo tempo, tanto a BioNTech quanto a Moderna também vêm desenvolvendo vacinas mais gerais, que podem ser utilizadas para vários tipos de câncer mais rapidamente, sem precisar do longo processo de customização.

Essas terapias são injetadas dentro dos tumores, instruindo as células cancerígenas a liberarem um coquetel de citocinas que desencadeiam uma resposta imunológica local, atacando o tumor.

A ideia de se usar citocinas localmente nos tumores não é nova, mas a vida curta e toxicidade dessas proteínas as impediam de serem injetadas diretamente.

O uso de terapias genéticas por DNA, que fica permanentemente no interior da célula, também trazia efeitos colaterais.

Dessa maneira, a vacina à base de mRNA resolveu esses problemas por liberar uma dose consistente e temporária do coquetel de citocinas, que depois é interrompida pela degradação natural do RNA dentro das células.

Embora não sejam tão imunogênicas quanto as vacinas personalizadas, as vacinas intratumorais podem ser potencializadas se utilizadas conjuntamente com outras terapias que aumentam a resposta imunológica, como os inibidores de checkpoint.

Outra tecnologia sendo testada é a inclusão na vacina de ferramentas moleculares para a replicação do mRNA dentro das células, que é capaz de fornecer doses maiores e mais prolongadas das citocinas.

Outras aplicações

As vacinas de RNA também prometem imunização contra várias doenças infecciosas que até hoje evadiram os métodos tradicionais. Entre elas, sonhos antigos como vacinas para gripe, Aids, tuberculose e malária, doenças que ainda são responsáveis por milhões de mortes pelo mundo, principalmente em países menos favorecidos.

Tanto a BioNTech quanto a Moderna inclusive já planejam novas fábricas na África, já prevendo os testes para vacinas contra malária no ano que vem.

Se ainda existia alguma dúvida quanto ao potencial das vacinas de RNA, cuja tecnologia necessitou superar várias barreiras até que funcionasse de maneira confiável, essa dúvida se dissipou com o sucesso estrondoso durante a pandemia.

Muito à frente da concorrência, as vacinas da BioNTech/Pfizer e da Moderna se tornaram a esperança do retorno a uma vida normal.

Nos EUA, onde essas vacinas correspondem à grande maioria das doses aplicadas, mais de 99% das mortes por covid atualmente são de pessoas não vacinadas.

Com a confiança da população, estrutura montada e dinheiro em caixa, o terreno é fértil para essas empresas investirem na cura de várias doenças. Pode ser o grande legado da pandemia.

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Após sucesso contra o coronavírus, tecnologia de vacina de mRNA mira câncer

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Daniel Schultz, Monica Matsumoto, Shridhar Jayanthi, Guilherme Pimentel , Luiz Gustavo Martins e Cristina Schultz Daniel Schultz é cientista, professor de microbiologia e membro do núcleo de ciências computacionais em Dartmouth (EUA). Estuda a dinâmica dos processos celulares, com foco na evolução de bactérias resistentes a antibióticos.