Discovery of the covalent SARS-CoV-2 Mpro inhibitors from antiviral herbs via integrating target-based high-throughput screening and chemoproteomic approaches.

The main proteases (Mpro ) are highly conserved cysteine-rich proteins that can be covalently modified by numerous natural and synthetic compounds. Herein, we constructed an integrative approach to efficiently discover covalent inhibitors of Mpro from complex herbal matrices. This work begins with biological screening of 60 clinically used antiviral herbal medicines, among which Lonicera japonica Flos (LJF) demonstrated the strongest anti-Mpro effect (IC50 = 37.82 µg/mL). Mass spectrometry (MS)-based chemical analysis and chemoproteomic profiling revealed that LJF extract contains at least 50 constituents, of which 22 exhibited the capability to covalently modify Mpro . We subsequently verified the anti-Mpro effects of these covalent binders. Gallic acid and quercetin were found to potently inhibit severe acute respiratory syndrome coronavirus 2 Mpro in dose- and time- dependent manners, with the IC50 values below 10 µM. The inactivation kinetics, binding affinity and binding mode of gallic acid and quercetin were further characterized by fluorescence resonance energy transfer, surface plasmon resonance, and covalent docking simulations. Overall, this study established a practical approach for efficiently discovering the covalent inhibitors of Mpro from herbal medicines by integrating target-based high-throughput screening and MS-based assays, which would greatly facilitate the discovery of key antiviral constituents from medicinal plants.

Mechanism of the Anti-Influenza Functions of Guizhi Granules Based on Network Pharmacology, Molecular Docking, and in Vitro Experiments.

Guizhi granules mainly treat colds and improve overall health. They are widely used in clinical practice, but their protective effect and anti-inflammatory mechanism against influenza are unclear. In this study, the therapeutic effect of Guizhi granules on influenza was verified in vitro. The active compounds, targets, and cellular pathways of Guizhi granules against influenza were predicted using network pharmacology. The protein-protein interaction and component-target networks identified 5 core targets (JUN, TNF-α, RELA, AKT1, and MAPK1) and components (dihydrocapsaicin, kumatakenin, calycosin, licochalcone A, and berberine). GO and KEGG enrichment analyses revealed the anti-influenza pathways of Guizhi granules as antiviral and anti-inflammatory pathways. Molecular docking further verified that the core targets and components have good or strong binding activity. Therefore, the active ingredients, targets, and molecular mechanisms of Guizhi granules involved in influenza treatment were elucidated.

The effect of Psidium guajava Leaves' extract for mild and asymptomatic corona virus Disease-19.

COVID-19 is an emerging disease that attacks the respiratory and systemic systems. Various treatments have been used for COVID-19, but no antiviral agents seemed to be efficacious. Many medicinal plants are commonly used for viral infections in Indonesia, including the guajava leaf. The study aimed to determine the effects of Psidium guajava extract supplementation on inflammation markers of asymptomatic and mild COVID-19 patients. The conversion time of PCR results was also evaluated. This study was an experimental, single-blinded, randomized clinical trial (ClinicalTrials.gov: NCT04810728) comparing the efficacy of P. guajava extract at the dose of 1000 mg/8h on top of standard treatment with the standard treatment only for asymptomatic and mild COVID-19 subjects. The primary endpoints were neutrophil and lymphocyte percentages as well as the neutrophil/lymphocyte ratio (NLR) on day 7 of the treatment. The secondary endpoints were high-sensitivity c-reactive protein (hs-CRP) level, PCR-based conversion time, and recovery rate at weeks 2 and 4. A total of 90 subjects were enrolled, and there were 40 subjects in the P. guajava (experimental) group and 41 subjects in the control group who completed the research. On day 7, significantly lower percentage of neutrophil (52.4% vs 58.9%, p = 0.002), higher lymphocyte percentage (35.5%, vs 29.7%, p = 0.002), and lower NLR (1.5 vs 2.1, p = 0.001) were demonstrated in the experimental versus control group. The PCR-based conversion time was shorter (14 days vs 16 days, p < 0.001), and recovery rate at 2 and 4 weeks were higher (49% vs 27%, p = 0.03 and 100% vs 82%, p = 0.003, respectively) in the experimental group. There were no differences in the baseline characteristics. P. guajava extract supplementation reduced neutrophil and increased lymphocyte percentages which led to reduced NLR, accelerated PCR-based conversion time, and increased recovery rate in subjects with mild and asymptomatic COVID-19 infection.\.

Plant ingredients in Thai food: a well-rounded diet for natural bioactive associated with medicinal properties.

Background: Seeking cures for chronic inflammation-associated diseases and infectious diseases caused by critical human pathogens is challenging and time-consuming. Even as the research community searches for novel bioactive agents, consuming a healthy diet with functional ability might be an effective way to delay and prevent the progression of severe health conditions. Many plant ingredients in Thai food are considered medicinal, and these vegetables, herbs, and spices collectively possess multiple biological and pharmacological activities, such as anti-inflammatory, antimicrobial, antidiabetic, antipyretic, anticancer, hepatoprotective, and cardioprotective effects. Methodology: In this review, the selected edible plants are unspecific to Thai food, but our unique blend of recipes and preparation techniques make traditional Thai food healthy and functional. We searched three electronic databases: PUBMED, Science Direct, and Google Scholar, using the specific keywords "Plant name" followed by "Anti-inflammatory" or "Antibacterial" or "Antiviral" and focusing on articles published between 2017 and 2021. Results: Our selection of 69 edible and medicinal plant species (33 families) is the most comprehensive compilation of Thai food sources demonstrating biological activities to date. Focusing on articles published between 2017 and 2021, we identified a total of 245 scientific articles that have reported main compounds, traditional uses, and pharmacological and biological activities from plant parts of the selected species. Conclusions: Evidence indicates that the selected plants contain bioactive compounds responsible for anti-inflammatory, antibacterial, and antiviral properties, suggesting these plants as potential sources for bioactive agents and suitable for consumption for health benefits.

Persicamidines-Unprecedented Sesquarterpenoids with Potent Antiviral Bioactivity against Coronaviruses.

A new family of highly unusual sesquarterpenoids (persicamidines A-E) exhibiting significant antiviral activity was isolated from a newly discovered actinobacterial strain, Kibdelosporangium persicum sp. nov., collected from a hot desert in Iran. Extensive NMR analysis unraveled a hexacyclic terpenoid molecule with a modified sugar moiety on one side and a highly unusual isourea moiety fused to the terpenoid structure. The structures of the five analogues differed only in the aminoalkyl side chain attached to the isourea moiety. Persicamidines A-E showed potent activity against hCoV-229E and SARS-CoV-2 viruses in the nanomolar range together with very good selectivity indices, making persicamidines promising as starting points for drug development.

Therapeutic approaches for chronic hepatitis C: a concise review.

Hepatitis C virus (HCV) infection is a significant global health concern, prompting the need for effective treatment strategies. This in-depth review critically assesses the landscape of HCV treatment, drawing parallels between traditional interferon/ribavirin therapy historically pivotal in HCV management and herbal approaches rooted in traditional and complementary medicine. Advancements in therapeutic development and enhanced clinical outcomes axis on a comprehensive understanding of the diverse HCV genome, its natural variations, pathogenesis, and the impact of dietary, social, environmental, and economic factors. A thorough analysis was conducted through reputable sources such as Science Direct, PubMed, Scopus, Web of Science, books, and dissertations. This review primarily focuses on the intricate nature of HCV genomes and explores the potential of botanical drugs in both preventing and treating HCV infections.

Effects of Lipophilicity and Structural Features on the Antiherpes Activity of Digitalis Cardenolides and Derivatives.

There is growing interest in exploring Digitalis cardenolides as potential antiviral agents. Hence, we herein investigated the influence of structural features and lipophilicity on the antiherpes activity of 65 natural and semisynthetic cardenolides assayed in vitro against HSV-1. The presence of an α,ß-unsaturated lactone ring at C-17, a ß-hydroxy group at C-14 and C-3ß-OR substituents were considered essential requirements for this biological activity. Glycosides were more active than their genins, especially monoglycosides containing a rhamnose residue. The activity enhanced in derivatives bearing an aldehyde group at C-19 instead of a methyl group, whereas inserting a C-5ß-OH improved the antiherpes effect significantly. The cardenolides lipophilicity was accessed by measuring experimentally their log P values (n-octanol-water partition coefficient) and disclosed a range of lipophilicity (log P 0.75±0.25) associated with the optimal antiherpes activity. In silico studies were carried out and resulted in the establishment of two predictive models potentially useful to identify and/or optimize novel antiherpes cardenolides. The effectiveness of the models was confirmed by retrospective analysis of the studied compounds. This is the first SAR study addressing the antiherpes activity of cardenolides. The developed computational models were able to predict the active cardenolides and their log P values.

Sequence-Specific Features of Short Double-Strand, Blunt-End RNAs Have RIG-I- and Type 1 Interferon-Dependent or -Independent Anti-Viral Effects.

Pathogen-associated molecular patterns, including cytoplasmic DNA and double-strand (ds)RNA trigger the induction of interferon (IFN) and antiviral states protecting cells and organisms from pathogens. Here we discovered that the transfection of human airway cell lines or non-transformed fibroblasts with 24mer dsRNA mimicking the cellular micro-RNA (miR)29b-1* gives strong anti-viral effects against human adenovirus type 5 (AdV-C5), influenza A virus X31 (H3N2), and SARS-CoV-2. These anti-viral effects required blunt-end complementary RNA strands and were not elicited by corresponding single-strand RNAs. dsRNA miR-29b-1* but not randomized miR-29b-1* mimics induced IFN-stimulated gene expression, and downregulated cell adhesion and cell cycle genes, as indicated by transcriptomics and IFN-I responsive Mx1-promoter activity assays. The inhibition of AdV-C5 infection with miR-29b-1* mimic depended on the IFN-alpha receptor 2 (IFNAR2) and the RNA-helicase retinoic acid-inducible gene I (RIG-I) but not cytoplasmic RNA sensors MDA5 and ZNFX1 or MyD88/TRIF adaptors. The antiviral effects of miR29b-1* were independent of a central AUAU-motif inducing dsRNA bending, as mimics with disrupted AUAU-motif were anti-viral in normal but not RIG-I knock-out (KO) or IFNAR2-KO cells. The screening of a library of scrambled short dsRNA sequences identified also anti-viral mimics functioning independently of RIG-I and IFNAR2, thus exemplifying the diverse anti-viral mechanisms of short blunt-end dsRNAs.

Effects of bioactive compounds from Pleurotus mushrooms on COVID-19 risk factors associated with the cardiovascular system.

Mushrooms are a group of fungi with great diversity and ultra-accelerated metabolism. As a consequence, mushrooms have developed a protective mechanism consisting of high concentrations of antioxidants such as selenium, polyphenols, ß-glucans, ergothioneine, various vitamins and other bioactive metabolites. The mushrooms of the Pleurotus genus have generated scientific interest due to their therapeutic properties, especially related to risk factors connected to the severity of coronavirus disease 2019 (COVID-19). In this report, we highlight the therapeutic properties of Pleurotus mushrooms that may be associated with a reduction in the severity of COVID-19: antihypertensive, antihyperlipidemic, antiatherogenic, anticholesterolemic, antioxidant, anti-inflammatory and antihyperglycemic properties. These properties may interact significantly with risk factors for COVID-19 severity, and the therapeutic potential of these mushrooms for the treatment or prevention of this disease is evident. Besides this, studies show that regular consumption of Pleurotus species mushrooms or components isolated from their tissues is beneficial for immune health. Pleurotus species mushrooms may have a role in the prevention or treatment of infectious diseases either as food supplements or as sources for pharmacological agents.

Eliminate Hepatitis C as a Public Health Threat: A Narrative Review of Strategies, Gaps, and Opportunities for China.

INTRODUCTION: As a country that is heavily burdened by hepatitis C, China's successful responses to this public health threat have significant implications for the achievement of the global elimination goal. METHODS: This article reviews China's strategies for prevention, screening, diagnosis, access to direct-acting antiviral agents (DAA) therapy, and patient management of hepatitis C. It also analyses the major challenges and summarizes the valuable successful international experiences that have implications for China to achieve the elimination goal. RESULTS: To promote the achievement of elimination, China has taken a series of proactive measures to promote the prevention and treatment of hepatitis C. Compared with other middle-income countries, there is still much room for China to achieve universal screening, diagnosis and treatment based on a streamlined disease management procedure. A stronger role of primary care in an integrated healthcare delivery system and integration of hepatitis C with other infectious disease programs should also be the focus of China's efforts. CONCLUSIONS: As a developing country with a large population, a "micro-elimination" strategy with focused screening and proactive diagnosis and treatment for the vulnerable population may be a more practical approach to eliminating hepatitis C in China. Continued efforts are needed to fully overcome the intellectual property barriers of sofosbuvir for forming the more competitive pan-genotype DAA combinations based on the locally developed DAAs. Meanwhile, the safety net for patients in economic hardship needs to be further strengthened. More importantly, it is necessary to promote patients' willingness and compliance with standard treatment through increased awareness of hepatitis C. The development of an integrated healthcare delivery system, a disease management procedure which is suitable for primary care, and full compliance of the primary care providers are also important to achieve effective cascade care management.

In vitro antiviral activity against SARS-CoV-2 of plant extracts used in Colombian traditional medicine / Actividad antiviral in vitro contra el SARS-CoV-2 de extractos de plantas usados en medicina tradicional colombiana

Background: Coronavirus infectious disease 2019 (COVID-19) caused by the infection with the new coronavirus SARS-CoV-2 has affected the life and health of more than 222 million people. In the absence of any specific pharmacological treatment, the need to find new therapeutic alternatives is clear. Medicinal plants are widely used worldwide to treat different conditions, including COVID-19; however, in most cases, there are no specific studies to evaluate the efficacy of these treatments. Objective: This article evaluates the antiviral effect of six plant extracts used by indigenous and afro Colombian people against SARS-CoV-2 in vitro. Methods: The antiviral effect of six extracts prepared from plants used in Colombian traditional medicine was evaluated against SARS-CoV-2 through a pre-post treatment strategy on the Vero E6 cell line. Once cytotoxicity was established through an MTT assay, the antiviral effect of the extracts was calculated based on the reduction in the viral titer determined by plaque assay. Results:Gliricidia sepium inhibited SARS-CoV-2 in a 75.6%, 56.8%, 62.5% and 40.0% at 10 mg/mL, 8 mg/mL, 6 mg/mL, and 2 mg/mL, respectively, while Piper tuberculatumtreatment reduced viral titer in 33.3% at 6 mg/mL after 48h. Conclusion:G. sepium and P. tuberculatum extracts exhibit antiviral activity against SARS-CoV-2 in vitro

Introducción: La enfermedad infecciosa causada por el coronavirus 2019 (COVID-19) generada por la infección con el nuevo coronavirus SARS-CoV-2 ha afectado la vida y la salud de mas de 222 millones de personas. En ausencia de algún tratamiento farmacológico específico, la necesidad de encontrar nuevas alternativas terapéuticas es clara. Las plantas medicinales son utilizadas en todo el mundo para tratar diferentes condiciones, incluyendo el COVID-19; sin embargo, en la mayoría de los casos no existen estudios específicos que evalúen la eficacia de estos tratamientos. Objetivo: En este artículo, evaluamos el efecto antiviral de seis extractos de plantas usadas por pueblos indígenas y afrocolombianos contra el SARS-CoV-2 in vitro.Metodología: El efecto antiviral de seis extractos preparados a partir de plantas usadas en medicina tradicional colombiana fue evaluado contra SARS-CoV-2 por medio de una estrategia de pre-post tratamiento en células Vero E6. Una vez se estableció la citotoxicidad por un ensayo de MTT, el efecto antiviral de estos extractos fue calculado basado en la reducción del título viral determinado por ensayo de plaqueo. Resultados:G. sepium inhibió SARS-CoV-2 en un 75.6%, 56.8%, 62.5% y 40.0% a 10 mg/mL, 8 mg/mL, 6 mg/mL, and 2 mg/mL, respectivamente. Mientras el extracto de Piper tuberculatum redujo el título viral en un 33.3% a 6 mg/mL luego de 48h de tratamiento

Immunomodulatory Effects of Allium sativum L. and its Constituents against Viral Infections and Metabolic Diseases.

BACKGROUND: Allium sativum L., or garlic, is one of the most studied plants worldwide within the field of traditional medicine. Current interests lie in the potential use of garlic as a preventive measure and adjuvant treatment for viral infections, e.g., SARS-CoV-2. Even though it cannot be presented as a single treatment, its beneficial effects are beyond doubt. The World Health Organization has deemed it an essential part of any balanced diet with immunomodulatory properties. OBJECTIVE: The aim of the study was to review the literature on the effects of garlic compounds and preparations on immunomodulation and viral infection management, with emphasis on SARS-CoV- -2. METHODS: Exhaustive literature search has been carried out on electronic databases. CONCLUSION: Garlic is a fundamental part of a well-balanced diet which helps maintain general good health. The reported information regarding garlic's ability to beneficially modulate inflammation and the immune system is encouraging. Nonetheless, more efforts must be made to understand the actual medicinal properties and mechanisms of action of the compounds found in this plant to inhibit or diminish viral infections, particularly SARS-CoV-2. Based on our findings, we propose a series of innovative strategies to achieve such a challenge in the near future.

A Photoactivable Natural Product with Broad Antiviral Activity against Enveloped Viruses, Including Highly Pathogenic Coronaviruses.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has highlighted the need for broad-spectrum antivirals against coronaviruses (CoVs). Here, pheophorbide a (Pba) was identified as a highly active antiviral molecule against human CoV-229E after bioguided fractionation of plant extracts. The antiviral activity of Pba was subsequently shown for SARS-CoV-2 and Middle East respiratory syndrome coronavirus (MERS-CoV), and its mechanism of action was further assessed, showing that Pba is an inhibitor of coronavirus entry by directly targeting the viral particle. Interestingly, the antiviral activity of Pba depends on light exposure, and Pba was shown to inhibit virus-cell fusion by stiffening the viral membrane, as demonstrated by cryoelectron microscopy. Moreover, Pba was shown to be broadly active against several other enveloped viruses and reduced SARS-CoV-2 and MERS-CoV replication in primary human bronchial epithelial cells. Pba is the first described natural antiviral against SARS-CoV-2 with direct photosensitive virucidal activity that holds potential for COVID-19 therapy or disinfection of SARS-CoV-2-contaminated surfaces.

Repurposing pharmaceutical excipients as an antiviral agent against SARS-CoV-2.

The limited time indorsed to face the COVID-19 emergency and large number of deaths across the globe, poses an unrelenting challenge to find apt therapeutic approaches. However, lead candidate selection to phase III trials of new chemical entity is a time-consuming procedure, and not feasible in pandemic, such as the one we are facing. Drug repositioning, an exploration of existing drug for new therapeutic use, could be an effective alternative as it allows fast-track estimation in phase II-III trials, or even forthright compassionate use. Although, drugs repurposed for COVID-19 pandemic are commercially available, yet the evaluation of their safety and efficacy is tiresome and painstaking. In absence of any specific treatment the easy alternatives such as over the counter products, phytotherapies and home remedies have been largely adopted for prophylaxis and therapy as well. In recent years, it has been demonstrated that several pharmaceutical excipients possess antiviral properties making them prospective candidates against SARS-CoV-2. This review highlights the mechanism of action of various antiviral excipients and their propensity to act against SARs-CoV2. Though, repurposing of pharmaceutical excipients against COVID-19 has the edge over therapeutic agents in terms of safety, cost and fast-track approval trial burdened, this hypothesis needs to be experimentally verified for COVID-19 patients.

Effects of bioactive compounds from Pleurotus mushrooms on COVID-19 risk factors associated with the cardiovascular system / 中西医结合学报

Mushrooms are a group of fungi with great diversity and ultra-accelerated metabolism. As a consequence, mushrooms have developed a protective mechanism consisting of high concentrations of antioxidants such as selenium, polyphenols, β-glucans, ergothioneine, various vitamins and other bioactive metabolites. The mushrooms of the Pleurotus genus have generated scientific interest due to their therapeutic properties, especially related to risk factors connected to the severity of coronavirus disease 2019 (COVID-19). In this report, we highlight the therapeutic properties of Pleurotus mushrooms that may be associated with a reduction in the severity of COVID-19: antihypertensive, antihyperlipidemic, antiatherogenic, anticholesterolemic, antioxidant, anti-inflammatory and antihyperglycemic properties. These properties may interact significantly with risk factors for COVID-19 severity, and the therapeutic potential of these mushrooms for the treatment or prevention of this disease is evident. Besides this, studies show that regular consumption of Pleurotus species mushrooms or components isolated from their tissues is beneficial for immune health. Pleurotus species mushrooms may have a role in the prevention or treatment of infectious diseases either as food supplements or as sources for pharmacological agents.

Carotenoids: Therapeutic Strategy in the Battle against Viral Emerging Diseases, COVID-19: An Overview.

Carotenoids, a group of phytochemicals, are naturally found in the Plant kingdom, particularly in fruits, vegetables, and algae. There are more than 600 types of carotenoids, some of which are thought to prevent disease, mainly through their antioxidant properties. Carotenoids exhibit several biological and pharmaceutical benefits, such as anti-inflammatory, anti-cancer, and immunity booster properties, particularly as some carotenoids can be converted into vitamin A in the body. However, humans cannot synthesize carotenoids and need to obtain them from their diets or via supplementation. The emerging zoonotic virus severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), originated in bats, and was transmitted to humans. COVID-19 continues to cause devastating international health problems worldwide. Therefore, natural preventive therapeutic strategies from bioactive compounds, such as carotenoids, should be appraised for strengthening physiological functions against emerging viruses. This review summarizes the most important carotenoids for human health and enhancing immunity, and their potential role in COVID-19 and its related symptoms. In conclusion, promising roles of carotenoids as treatments against emerging disease and related symptoms are highlighted, most of which have been heavily premeditated in studies conducted on several viral infections, including COVID-19. Further in vitro and in vivo research is required before carotenoids can be considered as potent drugs against such emerging diseases.

IL28B rs12979860 polymorphism and zinc supplementation affect treatment outcome and liver fibrosis after direct-acting antiviral hepatitis C therapy.

BACKGROUND: Impact of interleukin 28B (IL28B) rs12979860 polymorphism on response to direct-acting antivirals agents in HCV genotype 4-infected patients is under investigation. Zinc may have an advantage in improvement of liver damage and treatment outcome. We aimed to evaluate IL28B polymorphism and zinc administration impact on patient response to treatment and amelioration of liver fibrosis. RESULTS: Three hundred patients on anti-HCV treatments were equally categorized into patients treated with dual therapy (sofosbuvir/ribavirin) for 24 weeks, triple therapy (sofosbuvir/ribavirin+pegylated interferon-alpha) for 12 weeks, dual therapy plus oral zinc and with triple therapy plus oral zinc. All patients were genotyped for IL28B. Sustained virologic response (SVR) was achieved in 100% of patients with CC genotypes while 15.5% of CT/TT carriers did not attain SVR. After treatment, patients with CC genotype showed improvement in liver-related parameters compared with CT/TT genotypes. Zinc supplementation was associated with improved SVR in CT/TT genotypes and liver parameters in both CC and CT/TT genotypes. Hepatic fibrosis was improved in higher percent of CC genotype (16.7%) compared with CT/TT genotypes (5.8%). Interestingly with zinc administration, improved fibrosis increased to 60.9% in CC genotype vs. 15.4% in CT/TT genotypes. CONCLUSION: Absolute SVR rates in patients with IL28B CC genotype support their selection for shorter treatment duration and therefore associated with high economic value. IL28B polymorphism is associated with improvement of hepatic functions and fibrosis after antiviral treatments. Zinc is powerful supplement not only to increase SVR in non-responders but also to improve hepatic functions and fibrosis.

Natural Bioactive Molecules as Potential Agents Against SARS-CoV-2.

In the past two decades, pandemics of several fatal coronaviruses have posed enormous challenges for public health, including SARS-CoV (2003), MERS-CoV (2012), and SARS-CoV-2 (2019). Among these, SARS-CoV-2 continues to ravage the world today and has lead to millions of deaths and incalculable economic damage. Till now, there is no clinically proven antiviral drug available for SARS-CoV-2. However, the bioactive molecules of natural origin, especially medicinal plants, have been proven to be potential resources in the treatment of SARS-CoV-2, acting at different stages of the viral life cycle and targeting different viral or host proteins, such as PLpro, 3CLpro, RdRp, helicase, spike, ACE2, and TMPRSS2. They provide a viable strategy to develop therapeutic agents. This review presents fundamental biological information on SARS-CoV-2, including the viral biological characteristics and invasion mechanisms. It also summarizes the reported natural bioactive molecules with anti-coronavirus properties, arranged by their different targets in the life cycle of viral infection of human cells, and discusses the prospects of these bioactive molecules for the treatment of COVID-19.

Gypenoside Inhibits Bovine Viral Diarrhea Virus Replication by Interfering with Viral Attachment and Internalization and Activating Apoptosis of Infected Cells.

Bovine viral diarrhea virus (BVDV) causes a severe threat to the cattle industry due to ineffective control measures. Gypenoside is the primary component of Gynostemma pentaphyllum, which has potential medicinal value and has been widely applied as a food additive and herbal supplement. However, little is known about the antiviral effects of gypenoside. The present study aimed to explore the antiviral activities of gypenoside against BVDV infection. The inhibitory activity of gypenoside against BVDV was assessed by using virus titration and performing Western blotting, quantitative reverse transcription PCR (RT-qPCR), and immunofluorescence assays in MDBK cells. We found that gypenoside exhibited high anti-BVDV activity by interfering with the viral attachment to and internalization in cells. The study showed that BVDV infection inhibits apoptosis of infected cells from escaping the innate defense of host cells. Our data further demonstrated that gypenoside inhibited BVDV infection by electively activating the apoptosis of BVDV-infected cells for execution, as evidenced by the regulation of the expression of the apoptosis-related protein, promotion of caspase-3 activation, and display of positive TUNEL staining; no toxicity was observed in non-infected cells. Collectively, the data identified that gypenoside exerts an anti-BVDV-infection role by inhibiting viral attachment and internalization and selectively purging virally infected cells. Therefore, our study will contribute to the development of a novel prophylactic and therapeutic strategy against BVDV infection.

Potent antiviral activity of Agrimonia pilosa, Galla rhois, and their components against SARS-CoV-2.

Agrimonia pilosa (AP), Galla rhois (RG), and their mixture (APRG64) strongly inhibited SARS-CoV-2 by interfering with multiple steps of the viral life cycle including viral entry and replication. Furthermore, among 12 components identified in APRG64, three displayed strong antiviral activity, ursolic acid (1), quercetin (7), and 1,2,3,4,6-penta-O-galloyl-ß-d-glucose (12). Molecular docking analysis showed these components to bind potently to the spike receptor-binding-domain (RBD) of the SARS-CoV-2 and its variant B.1.1.7. Taken together, these findings indicate APRG64 as a potent drug candidate to treat SARS-CoV-2 and its variants.