Antiviral potentials of medicinal plants

Stixis scandens leaf extract-loading ZnO nanoparticles for porcine epidemic diarrhea virus (PEDV) treatment

Porcine epidemic diarrhea (PED) is one of the diseases that causes great losses for livestock farmers. Because vaccines against the disease are not very effective, there is a great demand for biological products with effective resistance to PED virus (PEDV). One of the most important trends today is the use of active ingredients from nature in animal husbandry. This study aimed to create an effective agent against PEDV from the extract of Stixis scandens, which has been shown to inhibit PEDV. The aqueous (denoted as TCN) and ethanolic extracts (denoted as TCC) of Stixis scandens leaves were first prepared and then qualitatively analyzed for their chemical compositions. The TCN was used to synthesize ZnO nanoparticles (NPs) at various sizes from 20 to 120 nm. Subsequently, TCC was loaded on ZnO NPs to form ZnO-extract nanoformulations with an extract loading content of 5.8-7.6%. Total polyphenols (TP) and total alkaloids (TA) in TCC were 38.51 ± 0.25 μg GAE per mg and 22.37 ± 0.41 μg AtrE per mg, respectively. TP was less loaded but more released from the nanoformulations than TA. The A1T nanoformulation, containing only 7.6% extract, had a minimum PEDV inhibitory concentration of 3.9 μg mL-1, which was comparable to that of TCC. The experiments confirmed that the nanoformulations are promising for PEDV inhibition applications.

Insights of phytoremediation mechanisms for viruses based on in-vitro, in-vivo and in-silico assessments of selected herbal plants

Waterborne pathogenic viruses present unrelenting challenges to the global health and wastewater treatment industry. Phytoremediation offers promising solutions for wastewater treatment through plant-based technologies. This study investigated antiviral mechanisms in-vivo using bacteriophages MS2 and T4 as surrogates for effective herbs screened in-vitro from three embryophytes (Ocimum basilicum, Mentha sp., Plectranthus amboinicus), two macrophytes (Eichhornia crassipes, Pistia stratiotes) and a perennial grass (Cyperus rotundas). In-silico virtual screening predicted antiviral phytochemicals for further antiviral potency assessment. Results suggested in-vitro antiviral activities of embryophytes and macrophytes were higher (43-62%) than grass (21-26%). O. basilicum (OB, 57-62%) and P. stratiotes (PS, 59-60%) exhibited the highest antiviral activities. In-vivo tests showed notable virus reduction (>60%) in culture solution, attributed to rhizofiltration (66-74%) and phytoinactivation/phytodegradation (63-84%). In-silico analysis identified rutin as a primary antiviral phytochemical for MS2 (-9.7 kcal/mol) and T4 (-10.9 kcal/mol), correlating with dose-response inactivation (∼58-62%). In-vivo tests suggested additional phytocompounds may contribute to viral inactivation, presenting new opportunities for herb-based wastewater treatment solutions. Consequently, this study not only demonstrates the antiviral capabilities of OB and PS but also introduces an innovative approach for addressing viral contaminants in water.

Antibacterial, Antifungal, and Antiviral Bioactive Compounds from Natural Products

In the relentless pursuit of innovative therapeutic agents, natural products have emerged as a transformative avenue in the battle against infectious diseases [...].

Pharmacokinetics, dynamics, toxicology and molecular docking of bioactive alkaloid vasicine from Adhatoda vasica: a promising toxin binder against aflatoxin B1 and ochratoxin A

Vasicine from Adhatoda vasica was investigated in the management of aflatoxicosis and ochratoxicosis by in silico molecular docking approach. The computational analysis was carried out using Discovery Studio Autodock 4.5 tool. Absorption, distribution, metabolism, and excretion (ADME), pharmacodynamics and toxicity studies were also carried out using Swiss ADME and PASS online server, respectively. The standard drug compound used was silymarin and the structure were retrieved from the protein data bank for both the test compound vasicine and the standard drug. Vasicine interacted with aflatoxin B1 at 10 different poses and the maximum dock score was found to be 83.04 and the binding energy was -37.54 kcal/mol. Silymarin interacted with aflatoxin B1 at 10 different poses and the maximum dock score was found to be 143.578 and the binding energy was -67.32 kcal/mol. Vasicine interacted with ochratoxin A at 10 different poses and the maximum dock score was found to be 73.75 and the binding energy was -56.20 kcal/mol. Silymarin interacted with ochratoxin A at 10 different poses and the maximum dock score was found to be 89.23 and the binding energy was -98.86 kcal/mol. The compounds possess good gastro intestinal absorption with antioxidant property and exhibits minimum adverse effects. The obtained results support the toxin mitigating potential of the test compound with minimum adverse effects and hence vasicine can be regarded as a potential toxin binder of aflatoxin B1 and ochratoxin A, wherein it can be implemented for alleviating aflatoxicosis and ochratoxicosis.

Medicinal Plants against Viral Infections: A Review of Metabolomics Evidence for the Antiviral Properties and Potentials in Plant Sources

Most plants have developed unique mechanisms to cope with harsh environmental conditions to compensate for their lack of mobility. A key part of their coping mechanisms is the synthesis of secondary metabolites. In addition to their role in plants' defense against pathogens, they also possess therapeutic properties against diseases, and their use by humans predates written history. Viruses are a unique class of submicroscopic agents, incapable of independent existence outside a living host. Pathogenic viruses continue to pose a significant threat to global health, leading to innumerable fatalities on a yearly basis. The use of medicinal plants as a natural source of antiviral agents has been widely reported in literature in the past decades. Metabolomics is a powerful research tool for the identification of plant metabolites with antiviral potentials. It can be used to isolate compounds with antiviral capacities in plants and study the biosynthetic pathways involved in viral disease progression. This review discusses the use of medicinal plants as antiviral agents, with a special focus on the metabolomics evidence supporting their efficacy. Suggestions are made for the optimization of various metabolomics methods of characterizing the bioactive compounds in plants and subsequently understanding the mechanisms of their operation.

Enhancing nutritional value and health benefits of gluten-free confectionery products: innovative pastilles and marshmallows

Introduction

The research focuses on enhancing the nutritional value and potential health benefits of gluten-free confectionery products, developing innovative pastilles and marshmallows enriched with medicinal herb extracts, probiotics, and bioactive compounds from natural sources.

Methods

Physicochemical properties, including water activity, texture, and color, are assessed to evaluate the quality of the final products. Moreover, in vitro digestibility of the confectionery products is also investigated, with a focus on the release of bioactive compounds such as total phenolic compounds (TPC) and total anthocyanin (TAC) during simulated gastrointestinal digestion.

Results and discussion

Results indicate that the addition of specific ingredients to pastille samples does not lead to variations in water activity (~0.44), preserving the original properties, quality, and stability of the food. In contrast, the incorporation of additives in marshmallow products significantly increases water activity (p ≤ 0.05), attributed to their moisture-retaining effect. In general, our findings reveal that texture properties and color parameters are significantly affected by different formulations (p ≤ 0.05) for both confectionery products. Notably, the use of fruit and berries puree, along with the incorporation of additives, improves the functionality of confectionary products in terms of consumer acceptance (harder pastilles and softer marshmallow) and product quality. Furthermore, the study reveals that bioactive compounds are released and become more bioaccessible during digestion, particularly in the intestinal phase, with a maximum release exceeding 97% of TPC and TAC for both pastille and marshmallow samples. These findings pave the way for the development of a new category of gluten-free confectionery products, enriched with functional ingredients that offer potential health benefits, aligning with consumer preferences for natural, functional, and health-conscious treats. This research contributes to the evolving the landscape of functional confectionery products and underscores their potential as immune-boosting and naturally based food options.

In vitro anti-HIV, cytotoxicity and nutritional analysis of Trianthema portulacastrum L. (Aizoaceae)

The development of antiretroviral therapy has brought a tremendous relief to the world as it minimizes mortality, reduces HIV transmission, and suppresses progression in infected patients. However, the orthodox antiretroviral therapy is faced with limitations which have necessitated a continuous search for more novel plant-based antiviral compounds, which can bypass the existing barriers created by drug resistance and target more viral proteins. Despite the edibility and enormous pharmacological benefits of T. portulacastrum, little is known about its nutrient profiles and potential use as a natural source of antiviral drug. This study focuses on the full feed analysis and anti-HIV potential of two biotypes of T. portulacastrum. Ethanolic extracts of both biotypes of T. portulacastrum (T01 and T02) had significant inhibitory effects on the level of replication of the HIV-1. Both extracts induced the inhibition of at least 50% of the HIV-1 viral load at considerably low IC50 values of 1.757 mg/mL (T01) and 1.205 mg/mL (T02) which is comparable to the AZT standard. The protein composition ranged between 8.63-22.69%; fat (1.84-4.33%); moisture (7.89-9.04%); fibre (23.84-49.98%); and carbohydrate content (38.54-70.14%). Mineral contents of tested T. portulacastrum varied considerably in different parts of the plant. Nitrogen N mineral ranged between 13.8-36.3 mg/g; sodium Na (2.0-14.0 mg/g); potassium K (14.0-82.0 mg/g); magnesium Mg (2.8-7.1 mg/g); calcium Ca (9.1-24.7 mg/g); phosphorus P (1.3-3.6 mg/g); iron Fe (193.5-984.0 ppm); zinc Zn (42.5-96.0 ppm); manganese Mn (28.5-167.5 ppm); and copper Cu (2.0-8.5 ppm). These mineral values are comparable or higher than values quoted for common vegetables, suggesting that T. portulacastrum is a nutrient-dense vegetable that could provide alternative sources of antiviral nutrients to HIV-infected individuals. Further studies are recommended to unravel key metabolites responsible for high nutrient profiles and antiretroviral effects in T. portulacastrum.

The Overview of Potential Antiviral Bioactive Compounds in Poxviruses

Poxviruses belong to the family of double-stranded DNA viruses, and it is pathogenic for humans and spread worldwide. These viruses cause infections and various diseases in human. So, it is required to develop new drugs for the treatment of smallpox or other poxvirus infections. Very few potential compounds for the treatment of poxvirus such as smallpox, chickenpox, and monkeypox have been reported. Most of the compounds has used as vaccines. Cidofovir is most commonly used as a vaccine for the treatment of poxviruses. There are no phytochemicals reported for the treatment of poxviruses. Very few phytochemicals are under investigation for the treatment of poxviruses.

Antiviral Flavonoids: A Natural Scaffold with Prospects as Phytomedicines against SARS-CoV2

Flavonoids are vital candidates to fight against a wide range of pathogenic microbial infections. Due to their therapeutic potential, many flavonoids from the herbs of traditional medicine systems are now being evaluated as lead compounds to develop potential antimicrobial hits. The emergence of SARS-CoV-2 caused one of the deadliest pandemics that has ever been known to mankind. To date, more than 600 million confirmed cases of SARS-CoV2 infection have been reported worldwide. Situations are worse due to the unavailability of therapeutics to combat the viral disease. Thus, there is an urgent need to develop drugs against SARS-CoV2 and its emerging variants. Here, we have carried out a detailed mechanistic analysis of the antiviral efficacy of flavonoids in terms of their potential targets and structural feature required for exerting their antiviral activity. A catalog of various promising flavonoid compounds has been shown to elicit inhibitory effects against SARS-CoV and MERS-CoV proteases. However, they act in the high-micromolar regime. Thus a proper leadoptimization against the various proteases of SARS-CoV2 can lead to high-affinity SARS-CoV2 protease inhibitors. To enable lead optimization, a quantitative structure-activity relationship (QSAR) analysis has been developed for the flavonoids that have shown antiviral activity against viral proteases of SARS-CoV and MERS-CoV. High sequence similarities between coronavirus proteases enable the applicability of the developed QSAR to SARS-CoV2 proteases inhibitor screening. The detailed mechanistic analysis of the antiviral flavonoids and the developed QSAR models is a step forward toward the development of flavonoid-based therapeutics or supplements to fight against COVID-19.

Unveiling the Potent Antiviral and Antioxidant Activities of an Aqueous Extract from Caesalpinia mimosoides Lamk: Cheminformatics and Molecular Docking Approaches

Our group previously demonstrated that Caesalpinia mimosoides Lamk exhibits many profound biological properties, including anticancer, antibacterial, and antioxidant activities. However, its antiviral activity has not yet been investigated. Here, the aqueous extract of C. mimosoides was prepared from the aerial parts (leaves, stalks, and trunks) to see whether it exerts anti-influenza (H1N1) effects and to reduce the organic solvents consumed during extraction, making it a desirable approach for the large-scale production for medical uses. Our plant extract was quantified to contain 7 g of gallic acid (GA) per 100 g of a dry sample, as determined using HPLC analysis. It also exerts potent antioxidant activities comparable to those of authentic GA. According to untargeted metabolomics (UPLC-ESI(-)-QTOF-MS/MS) with the aid of cheminformatics tools (MetFrag (version 2.1), SIRIUS (version 5.8.3), CSI:FingerID (version 4.8), and CANOPUS), the major metabolite was best annotated as "gallic acid", phenolics (e.g., quinic acid, shikimic acid, and protocatechuic acid), sugar derivatives, and dicarboxylic acids were deduced from this plant species for the first time. The aqueous plant extract efficiently inhibited an influenza A (H1N1) virus infection of MDCK cells with an IC50 of 5.14 µg/mL. Of equal importance, hemolytic activity was absent for this plant extract, signifying its applicability as a safe antiviral agent. Molecular docking suggested that GA interacts with conserved residues (e.g., Arg152 and Asp151) located in the catalytic inner shell of the viral neuraminidase (NA), sharing the same pocket as those of anti-neuraminidase drugs, such as laninamivir and oseltamivir. Additionally, other metabolites were also found to potentially interact with the active site and the hydrophobic 430-cavity of the viral surface protein, suggesting a possibly synergistic effect of various phytochemicals. Therefore, the C. mimosoides aqueous extract may be a good candidate for coping with increasing influenza virus resistance to existing antivirals.

Role of phytocompounds as the potential anti-viral agent: an overview

Viral diseases are the most notorious infective agent(s) causing morbidity and mortality in every nook and corner for ages; viruses are active in host cells, and specific anti-virus medicines' developments remain uncanny. In this century of the biological era, human viruses act predominantly as versatile spreaders. The infection of the present COVID-19 virus is up in the air; blithely, the integument of medicinal chemistry approaches, particularly bioactive derived phytocompounds could be helpful to control those human viruses, recognized in the last 100 years. Indeed, natural products are being used for various therapeutic purposes. The major bioactive phytocompounds are chemically containing coumarin, thiosulfonate, steroid, polysaccharide, tannin, lignin, proanthocyanidin, terpene, quinone, saponin, flavonoid, alkaloid, and polyphenol, that are documented for inhibitory action against several viral infections. Mostly, about 20-30% of plants from tropical or temperate regions are known to have some antiviral activity. This comprehensive analysis of bioactive-derived phytocompounds would represent a significant impact and might be helpful for antiviral research and the current state of viral treatments.

Solanum nigrum L. in COVID-19 and post-COVID complications: a propitious candidate

COVID-19 is caused by severe acute respiratory syndrome coronavirus-2, SARS-CoV-2. COVID-19 has changed the world scenario and caused mortality around the globe. Patients who recovered from COVID-19 have shown neurological, psychological, renal, cardiovascular, pulmonary, and hematological complications. In some patients, complications lasted more than 6 months. However, significantly less attention has been given to post-COVID complications. Currently available drugs are used to tackle the complications, but new interventions must address the problem. Phytochemicals from natural sources have been evaluated in recent times to cure or alleviate COVID-19 symptoms. An edible plant, Solanum nigrum, could be therapeutic in treating COVID-19 as the AYUSH ministry of India prescribes it during the pandemic. S. nigrum demonstrates anti-inflammatory, immunomodulatory, and antiviral action to treat the SARS-CoV-2 infection and its post-complications. Different parts of the plant represent a reduction in proinflammatory cytokines and prevent multi-organ failure by protecting various organs (liver, kidney, heart, neuro, and lung). The review proposes the possible role of the plant S. nigrum in managing the symptoms of COVID-19 and its post-COVID complications based on in silico docking and pharmacological studies. Further systematic and experimental studies are required to validate our hypothesis.

Structure-based virtual screening of natural compounds against wild and mutant (R1155K, A1156T and D1168A) NS3-4A protease of Hepatitis C virus

NS3-4A, a serine protease, is a primary target for drug development against Hepatitis C Virus (HCV). However, the effectiveness of potent next-generation protease inhibitors is limited by the emergence of mutations and resulting drug resistance. To address this, in this study a structure-based drug design approach is employed to screen a large library of 7320 natural compounds against both wild-type and mutant variants of NS3-4A protease. Telaprevir, a widely used protease inhibitor, was recruited as the control drug. The top 10 compounds with favorable binding affinities underwent drug-likeness evaluation. Based on ADMET studies, complexes of NP_024762 and NP_006776 were selected for molecular dynamic simulations. Principal component analysis (PCA) was employed to explore the conformational space and protein dynamics of the protein-ligand complex using a Free Energy Landscape (FEL) approach. The cosine values obtained from FEL analysis ranged from 0 to 1, and eigenvectors with cosine values below 0.2 were chosen for further analysis. To forecast binding free energies and evaluate energy contributions per residue, the MM-PBSA method was employed. The results highlighted the crucial role of amino acids in the catalytic domain for the binding of the protease with phytochemicals. Stable associations between the top compounds and the target protease were confirmed by the formation of hydrogen bonds in the binding pocket involving residues: His1057, Gly1137, Ser1139, and Ala1157. These findings suggest the potential of these compounds for further validation through biological evaluation.Communicated by Ramaswamy H. Sarma.

Potential medicinal plants to combat viral infections: A way forward to environmental biotechnology

The viral diseases encouraged scientific community to evaluate the natural antiviral bioactive components rather than protease inhibitors, harmful organic molecules or nucleic acid analogues. For this purpose, medicinal plants have been gaining tremendous importance in the field of attenuating the various kinds of infectious and non-infectious diseases. Most of the commonly used medicines contains the bioactive components/phytoconstituents that are generally extracted from medicinal plants. Moreover, the medicinal plants offer many advantages for the recovery applications of infectious disease especially in viral infections including HIV-1, HIV-2, Enterovirus, Japanese Encephalitis Virus, Hepatitis B virus, Herpes Virus, Respiratory syncytial virus, Chandipura virus and Influenza A/H1N1. Considering the lack of acceptable drug candidates and the growing antimicrobial resistance to existing drug molecules for many emerging viral diseases, medicinal plants may offer best platform to develop sustainable/efficient/economic alternatives against viral infections. In this regard, for exploring and analyzing large volume of scientific data, bibliometric analysis was done using VOS Viewer shedding light on the emerging areas in the field of medicinal plants and their antiviral activity. This review covers most of the plant species that have some novel bioactive compound like gnidicin, gniditrin, rutin, apigenin, quercetin, kaempferol, curcumin, tannin and oleuropin which showed high efficacy to inhibit the several disease causing virus and their mechanism of action in HIV, Covid-19, HBV and RSV were discussed. Moreover, it also delves the in-depth mechanism of medicinal with challenges and future prospective. Therefore, this work delves the key role of environment in the biological field.

The antiviral potential of Phyllanthus species: a systematic review

Viral infections and diseases caused by viruses are worldwide problems. According to a WHO report, three to five million people are chronically infected with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) each year globally. Since some viruses mutate very quickly, developing antiviral drugs can be a daunting task. Moreover, currently used synthetic drugs are toxic and associated with side effects. Therefore, there is a need to search for alternative natural remedies that have low toxicity, a new mechanism of action, and no major side effects. Phyllanthus plants have traditionally been used to treat viral hepatitis and liver damage in many tropical and subtropical countries worldwide. In this review, we discuss the therapeutic potential of Phyllanthus spp. against HBV, HCV, HIV, herpes simplex virus, and SARS-CoV-2. The inferences from in vitro and in vivo studies and clinical trials validate the use of Phyllanthus in antiviral remedies.

Eupatin, a Flavonoid, Inhibits Coronavirus 3CL Protease and Replication

The coronavirus disease 2019 (COVID-19) pandemic has caused more than six million deaths worldwide since 2019. Although vaccines are available, novel variants of coronavirus are expected to appear continuously, and there is a need for a more effective remedy for coronavirus disease. In this report, we isolated eupatin from Inula japonica flowers and showed that it inhibits the coronavirus 3 chymotrypsin-like (3CL) protease as well as viral replication. We showed that eupatin treatment inhibits SARS-CoV-2 3CL-protease, and computational modeling demonstrated that it interacts with key residues of 3CL-protease. Further, the treatment decreased the number of plaques formed by human coronavirus OC43 (HCoV-OC43) infection and decreased viral protein and RNA levels in the media. These results indicate that eupatin inhibits coronavirus replication.

Exploration of the Molecular Basis of Forsythia Fruit in the Prevention and Treatment of Cholestatic Liver Injury through Network Pharmacology and Molecular Docking

Forsythia fruit, edible fruit of Forsythia suspensa (Thunb.) Vahl, which has been found to be effective in treating cholestasis. However, its key component for alleviating cholestasis has not been determined. In this study, four representative active ingredients in forsythia fruit were selected. Through network pharmacology and molecular docking technology, we tried to find the key component for its treatment of cholestasis. Furthermore, the model of cholestasis in mice was established to verify the protective effect of the key component on cholestasis. Network pharmacology and molecular docking showed that forsythoside A (FTA) is the key component of forsythia fruit in the treatment of cholestasis. In vivo experiments revealed that FTA treatment could alleviate liver injury, dysfunction, and collagen deposition induced by cholestasis in mice. At the same time, FTA treatment inhibited inflammatory factor release and fibrosis-related factor expression. In addition, FTA treatment also reduced MMP-2, TLR4, MYD88, NF-κB p65, and p-NF-κB p65 protein expression. In conclusion, FTA, a key component of forsythia fruit, alleviated liver damage and fibrosis caused by cholestasis via inhibiting the TLR4/NF-κB pathway, extracellular matrix accumulation, and inflammatory cytokine expression. The research results could provide a scientific reference for the development of forsythia fruit as a drug or functional food to prevent and treat cholestasis.

Anti-human immunodeficiency virus-1 activity of MoMo30 protein isolated from the traditional African medicinal plant Momordica balsamina

BACKGROUND

Plants are used in traditional healing practices of many cultures worldwide. Momordica balsamina is a plant commonly used by traditional African healers as a part of a treatment for HIV/AIDS. It is typically given as a tea to patients with HIV/AIDS. Water-soluble extracts of this plant were found to contain anti-HIV activity.

METHODS

We employed cell-based infectivity assays, surface plasmon resonance, and a molecular-cell model of the gp120-CD4 interaction to study the mechanism of action of the MoMo30-plant protein. Using Edman degradation results of the 15 N-terminal amino acids, we determined the gene sequence of the MoMo30-plant protein from an RNAseq library from total RNA extracted from Momordica balsamina.

RESULTS

Here, we identify the active ingredient of water extracts of the leaves of Momordica balsamina as a 30 kDa protein we call MoMo30-plant. We have identified the gene for MoMo30 and found it is homologous to a group of plant lectins known as Hevamine A-like proteins. MoMo30-plant is distinct from other proteins previously reported agents from the Momordica species, such as ribosome-inactivating proteins such as MAP30 and Balsamin. MoMo30-plant binds to gp120 through its glycan groups and functions as a lectin or carbohydrate-binding agent (CBA). It inhibits HIV-1 at nanomolar levels and has minimal cellular toxicity at inhibitory levels.

CONCLUSIONS

CBAs like MoMo30 can bind to glycans on the surface of the enveloped glycoprotein of HIV (gp120) and block entry. Exposure to CBAs has two effects on the virus. First, it blocks infection of susceptible cells. Secondly, MoMo30 drives the selection of viruses with altered glycosylation patterns, potentially altering their immunogenicity. Such an agent could represent a change in the treatment strategy for HIV/AIDS that allows a rapid reduction in viral loads while selecting for an underglycosylated virus, potentially facilitating the host immune response.

Specialized metabolites from plants as a source of new multi-target antiviral drugs: a systematic review

Viral infections have always been the main global health challenge, as several potentially lethal viruses, including the hepatitis virus, herpes virus, and influenza virus, have affected human health for decades. Unfortunately, most licensed antiviral drugs are characterized by many adverse reactions and, in the long-term therapy, also develop viral resistance; for these reasons, researchers have focused their attention on investigating potential antiviral molecules from plants. Natural resources indeed offer a variety of specialized therapeutic metabolites that have been demonstrated to inhibit viral entry into the host cells and replication through the regulation of viral absorption, cell receptor binding, and competition for the activation of intracellular signaling pathways. Many active phytochemicals, including flavonoids, lignans, terpenoids, coumarins, saponins, alkaloids, etc., have been identified as potential candidates for preventing and treating viral infections. Using a systematic approach, this review summarises the knowledge obtained to date on the in vivo antiviral activity of specialized metabolites extracted from plant matrices by focusing on their mechanism of action.

Antiviral Effects of the Plant Family Amaryllidaceae

Background

In spite of the significant progress in modern medicine, viruses continue to be a formidable challenge to human health. The use of plants for the remediation of viral-borne diseases stretches back to the very dawn of mankind. Among bulbous plants, the Amaryllidaceae is one of the most popular families exploited in the traditional remediation of infectious diseases.

Methods

This account details the findings from a literature search carried out on the antiviral properties of the Amaryllidaceae. The keyword engaged in the search was “antiviral” in combination with the words “Amaryllidaceae,” “Amaryllidaceae specie,” and “Amaryllidaceae alkaloid.”

Results

Thirty-six taxa from 13 countries, notably in Africa and parts of Asia, have been cited as traditional remedies for viral diseases. Alcoholic bulb extracts of 18 species were evaluated against 23 different pathogens from 13 viral families. A wide range of activities was observed, with the whole-plant methanol extract of Zephyranthes candida seen to be the most striking (IC50 0.0019 µg/mL against poliovirus). The active principles in the main were isoquinoline alkaloids, of which lycorine impressed against the Avian influenza virus (strain H5N1). The mechanisms underlying the antiviral effects were seen to be related to the inhibition of DNA, RNA, and protein synthesis as well as inhibitory effects toward reverse transcriptase and protease enzymes.

Conclusion

Amaryllidaceae provides a richly diverse platform for antiviral drug research. Such endeavors have been fortified by the significant amounts of information emerging from indigenous knowledge systems. Ongoing studies will continue to target the active entities, particularly from taxa with verifiable ethnomedicinal backgrounds.

Antiviral Potential of Traditional Unani Medicine with Special Emphasis on Dengue: A Review

Dengue fever has become a major public health concern. It is usually related to intravascular leaking, bleeding disorders, and thrombocytopenia and is recognized as a potent threat to humans. The scarcity of anti-dengue medication or vaccine for such a serious disease leads to an upsurge in the usage of traditional medicines for its proper management. India has diverse biodiversity and a long history of using plant-based remedies. Several medicinal plant extracts have been studied for producing anti-dengue viral activity. AYUSH traditional systems provide a plethora of plants that have been reported to be useful in the treatment of fever. Single and compound plant- based formulations in natural form have been used in Unani holistic approaches. This review serves as a new approach to illustrate the most recent evidence regarding the antiviral activity of various plants by providing scientific proof and also to validate the traditional formulations as effective treatments in dengue fever for global acceptance.

Antiviral alkaloid principles of the plant family Amaryllidaceae

BACKGROUND

Viral-borne diseases are amongst the oldest diseases known to mankind. They are responsible for some of the most ravaging effects wrought on human health and well-being. The use of plants against these ailments is entrenched in both traditional and secular medicine around the globe. Their natural abundance and chemical diversity have also boosted their appeal in drug discovery.

AIM

The plant family Amaryllidaceae is distinguished for its alkaloid principles, some of which are of considerable interest in the clinical arena. This account is the outcome of a literature review undertaken to establish the applicability of these substances as antiviral agents.

METHODS

The survey utilized the search engines Google Scholar, PubMed, SciFinder, Scopus and Web of Science engaging the word 'antiviral' in conjunction with 'Amaryllidaceae' and 'Amaryllidaceae alkaloid'. The search returned over five hundred hits, of which around eighty were of relevance to the theme of the text.

RESULTS

Over eighty isoquinoline alkaloids have been screened against nearly fifty pathogens from fourteen viral families, the majority of which were RNA viruses. Potent activities were reported in some instances, such as that of trans-dihydronarciclasine against Yellow fever virus (IC₅₀ 0.003 μg/ml), with minimal effects being manifested on host cells. There were also promising results obtained from in vivo studies, in most cases without lethal effects on test subjects. Structure-activity relationship studies afforded useful insight to the antiviral pharmacophore, with the phenanthridone alkaloid nucleus shown to be the most enabling. Although the mechanistic basis to these activities pertained mostly to inhibition of DNA, RNA and protein synthesis, evidence was also forthcoming about the inhibitory action of some of the alkaloids against viral neuraminidase, protease and reverse transcriptase. In silico methods of analysis have offered further perspectives of how some of the alkaloids interact at the active sites of their targets.

CONCLUSION

The Amaryllidaceae offers a viable platform for plant-based antiviral drug discovery. Its cause is strengthened not only by its wide proliferation and exploitation of its members in alternative forms of medicine, but also by its rich chemical diversity which has already spawned useful antiviral drug leads.

In Silico Identification of Anti-SARS-CoV-2 Medicinal Plants Using Cheminformatics and Machine Learning

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of COVID-19, is spreading rapidly and has caused hundreds of millions of infections and millions of deaths worldwide. Due to the lack of specific vaccines and effective treatments for COVID-19, there is an urgent need to identify effective drugs. Traditional Chinese medicine (TCM) is a valuable resource for identifying novel anti-SARS-CoV-2 drugs based on the important contribution of TCM and its potential benefits in COVID-19 treatment. Herein, we aimed to discover novel anti-SARS-CoV-2 compounds and medicinal plants from TCM by establishing a prediction method of anti-SARS-CoV-2 activity using machine learning methods. We first constructed a benchmark dataset from anti-SARS-CoV-2 bioactivity data collected from the ChEMBL database. Then, we established random forest (RF) and support vector machine (SVM) models that both achieved satisfactory predictive performance with AUC values of 0.90. By using this method, a total of 1011 active anti-SARS-CoV-2 compounds were predicted from the TCMSP database. Among these compounds, six compounds with highly potent activity were confirmed in the anti-SARS-CoV-2 experiments. The molecular fingerprint similarity analysis revealed that only 24 of the 1011 compounds have high similarity to the FDA-approved antiviral drugs, indicating that most of the compounds were structurally novel. Based on the predicted anti-SARS-CoV-2 compounds, we identified 74 anti-SARS-CoV-2 medicinal plants through enrichment analysis. The 74 plants are widely distributed in 68 genera and 43 families, 14 of which belong to antipyretic detoxicate plants. In summary, this study provided several medicinal plants with potential anti-SARS-CoV-2 activity, which offer an attractive starting point and a broader scope to mine for potentially novel anti-SARS-CoV-2 drugs.

In silico prediction of natural compounds as potential multi-target inhibitors of structural proteins of SARS-CoV-2

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a colossal loss to human health and lives and has deeply impacted socio-economic growth. Remarkable efforts have been made by the scientific community in containing the virus by successful development of vaccines and diagnostic kits. Initiatives towards drug repurposing and discovery have also been undertaken. In this study, we compiled the known natural anti-viral compounds using text mining of the literature and examined them against four major structural proteins of SARS-CoV-2, namely, spike (S) protein, nucleocapsid (N) protein, membrane (M) protein and envelope (E) protein. Following computational approaches, we identified fangchinoline and versicolactone C as the compounds to exhibit strong binding to the target proteins and causing structural deformation of three structural proteins (N, S and M). We recommend the inhibitory effects of these compounds from our study should be experimentally validated against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Secondary metabolites produced by endophytic fungi, Alternaria alternata, as potential inhibitors of the human immunodeficiency virus

Antiretroviral treatment has significantly reduced human immunodeficiency virus infection and mortality. However, the current treatment regimen is limited by adverse side effects, the emergence of drug resistance, and the inability to eliminate viral reservoirs. Here, fifteen endophytic fungi were isolated from Sclerocarya birrea and Hypoxis plants. Crude extracts of Alternaria alternata (strain ID PO4PR1, PO4PR2, and PO2PL1) of the fifteen isolate's crude extracts showed anti-HIV-1 activity in TZM-bl cell line at inhibitory concentration (IC₅₀) values ranging from 0.017 to 1.170 μg/ml. The three crude extracts also maintained the virus replication inhibition profile on PBMCs and CD4⁺ T cells at concentrations ranging from 0.3 to 50.2 ng/ml. Partial purification using the solid phase extraction and analysis with Gas Chromatography-Mass spectrophotometry showed a diverse profile. The bioactive compounds were identified based on peak area, retention time, similarity index. The major compounds from GC-MS analysis of A. Alternata revealed the existence of cyclotrisiloxane octamethyl (22.92%); Propaninitrile (16,67%); Pyrrolol[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl) (10.42%); Silane, diethylethoxy(2-ethoxyethyloxy) (4.17%); Coumarin, 3,4-dihydro-4,5,7-trimethyl- 4,5,7-Trimethyl-2-chromanone (13.7%) and 1,2-Cyclobutanedicarbonitrile (2.08%) with previously reported biological activities such as antimicrobial, anti-inflammatory and antioxidant properties. Therefore, these bioactive compounds from A. alternata fungal endophytes could be repurposed as potential anti-HIV agents. This study showed the potential of endophytic fungi, Alternaria alternata from S. birrea, and Hypoxis species as producers of anti-HIV compounds.

Paving New Roads Using Allium sativum as a Repurposed Drug and Analyzing its Antiviral Action Using Artificial Intelligence Technology

Context

The whole universe is facing a coronavirus catastrophe, and prompt treatment for the health crisis is primarily significant. The primary way to improve health conditions in this battle is to boost our immunity and alter our diet patterns. A common bulb veggie used to flavor cuisine is garlic. Compounds in the plant that are physiologically active are present, contributing to its pharmacological characteristics. Among several food items with nutritional value and immunity improvement, garlic stood predominant and more resourceful natural antibiotic with a broad spectrum of antiviral potency against diverse viruses. However, earlier reports have depicted its efficacy in the treatment of a variety of viral illnesses. Nonetheless, there is no information on its antiviral activities and underlying molecular mechanisms.

Objectives

The bioactive compounds in garlic include organosulfur (allicin and alliin) and flavonoid (quercetin) compounds. These compounds have shown immunomodulatory effects and inhibited attachment of coronavirus to the angiotensin-converting enzyme 2 (ACE2) receptor and the Mpro of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Further, we have discussed the contradictory impacts of garlic used as a preventive measure against the novel coronavirus.

Method

The GC/MS analysis revealed 18 active chemicals, including 17 organosulfur compounds in garlic. Using the molecular docking technique, we report for the first time the inhibitory effect of the under-consideration compounds on the host receptor ACE2 protein in the human body, providing a crucial foundation for understanding individual compound coronavirus resistance on the main protease protein of SARS-CoV-2. Allyl disulfide and allyl trisulfide, which make up the majority of the compounds in garlic, exhibit the most potent activity.

Results

Conventional medicine has proven its efficiency from ancient times. Currently, our article's prime spotlight was on the activity of Allium sativum on the relegation of viral load and further highlighted artificial intelligence technology to study the attachment of the allicin compound to the SARS-CoV-2 receptor to reveal its efficacy.

Conclusions

The COVID-19 pandemic has triggered interest among researchers to conduct future research on molecular docking with clinical trials before releasing salutary remedies against the deadly malady.

Scientific production on medicinal plants and their efficacy against Covid-19: A review and scientometric analysis based on VOSviewer

Historically, numerous plants have been used to alleviate various diseases, particularly viral diseases (bronchitis, influenza virus and dengue virus). This review evaluated their therapeutic potential against Covid-19 and mapped the 10 most studied plants during the pandemic. The standardized protocol for systematic reviews (PRISMA-P) was developed in this study. All studies involving medicinal plants and their potential against Covid-19 infection were also considered. Two specific search fields “traditional medicine and Covid-19” and “medicinal plants and Covid-19” with appearance in the title, abstract and keywords were used to search for information. Only papers (review and original) published between 2020 and October 2021 were included. Short communications, letters to the editor, books and book chapters were excluded. A total of 24,046 articles were recorded among the four databases and an increase of 69% in publications for the 2021 search date, a higher percentage compared to the previous year (31%). China was the country with the highest production with 28% (2725 papers). The analysis of variance showed that the number of studies of Nigella sativa L. (1.62 ± 0.21; p = 0.02), Glycyrrhiza glabra L. (1.50 ± 0.32; p = 0.03), Zingiber officinale Roscoe (1.51 ± 0.32; p = 0.03) were statistically significant with respect to the other species. This is probably because these species show compounds with high antiviral spectrum. Despite the pharmacological potential found in medicinal plants, more large-scale clinical trials are still needed to demonstrate the efficacy of phytocompounds against viral diseases.

Molecular dynamics simulation analysis of alpha-cobra toxin docked with phytochemical compounds

It is of interest to document data on the molecular dynamics simulation analysis of alpha-cobratoxin docked with phytochemical compounds. This can be used as effective drug candidates against the snake and scorpion venom. It should be noted experimental verification is needed to further validate the current data.

Prospecting for Cressa cretica to treat COVID-19 via in silico molecular docking models of the SARS-CoV-2

The severe acute respiratory syndrome COVID-19 declared as a global pandemic by the World Health Organization has become the present wellbeing worry to the whole world. There is an emergent need to search for possible medications. Cressa cretica is reported to show antitubercular, antibacterial and expectorant property. In this research, we aim to prospect the COVID-19 main protease crystal structure (Mpro; PDB ID: 6LU7) and the active chemical constituents from Cressa cretica in order to understand the structural basis of their interactions. We examined the binding potential of active constituents of Cressa cretica plant to immensely conserved protein Mpro of SARS-CoV-2 followed by exploration of the vast conformational space of protein-ligand complexes by molecular dynamics (MD) simulations. The results suggest the effectiveness of 3,5-Dicaffeoylquinic acid and Quercetin against standard drug Remdesivir. The active chemical constituents exhibited good docking scores, and interacts with binding site residues of Mpro by forming hydrogen bond and hydrophobic interactions. 3,5-Dicaffeoylquinic acid showed the best affinity towards Mpro receptor which is one of the target enzymes required by SARS CoV-2 virus for replication suggesting it to be a novel research molecule. The potential of the active chemical constituents from Cressa cretica against the SARS-CoV-2 virus has best been highlighted through this study. Therefore, these chemical entities can be further scrutinized and provides direction for further consideration for in-vivo and in-vitro validations for the treatment of covid-19. Communicated by Ramaswamy H. Sarma.

Anti-Coronavirus Efficiency and Redox-Modulating Capacity of Polyphenol-Rich Extracts from Traditional Bulgarian Medicinal Plants

Background: The use of various herbal therapists as part of traditional medicine in different parts of the world, including Bulgaria, is due to the knowledge accumulated over the centuries by people about their valuable biological activities. In this study, we investigate extracts from widely used Bulgarian medicinal plants for their ability to prevent the coronavirus infection of cells by testing different mechanisms of antiviral protection, their polyphenol content, and redox-modulating capacity. Methods: The influence on the stage of viral adsorption, the inhibition of extracellular virions, and the protective effect on uninfected cells of the plant’s extracts were reported by the end-point dilution method, and virus titer (in Δ lgs) was determined as compared to the untreated controls. The total content of polyphenols and flavonoids was also determined. We tested the antioxidant power of the extracts by their ability to inhibit the generation of superoxide anionic radicals and to scavenge DPPH radicals. We determined their iron-reducing, copper-reducing, and metal-chelating antioxidant powers. Results: Most of the extracts tested suppress the extracellular virions of HCov. They also inhibit the stage of viral adsorption to the host cell to varying degrees and have a protective effect on healthy cells before being subjected to viral invasion. The examined extracts contained significant levels of polyphenols and quercetin-like flavonoids and showed remarkable antioxidant, radical, and redox-modulating effects. Conclusions: All of these 13 extracts from Bulgarian medicinal plants tested can act as antioxidants and antiviral and symptomatic drugs for the management of coronavirus infection.

Effects of Plant Metabolites on the Growth of COVID-19 (Coronavirus Disease-19) Including Omicron Strain

According to recent reports out of India, a new strain of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) B1.1.529 Omicron virus has emerged. In comparison to the Wuhan (WHU) strain and the delta variant, this variant showed a far stronger effect on the angiotensin converting enzyme2 (ACE2) receptor. There are several medicinal compounds in plant metabolites, and their diverse chemical structures make them ideal for the treatment of serious illnesses. It's possible that some of these could be useful alternative pharmaceuticals, as well as a starting point for the repurposing of existing medications and new chemical discoveries. SARS-CoV-2 infection triggered a worldwide epidemic of the severe acute respiratory syndrome (SARS). There have been trials for different therapies for SARS-CoV-2 and so also there are recent announcements of extensive research into the development of viable medicines for this global health calamity. After a thorough examination of plant-derived treatments for COVID-19, investigators in the current study decided to focus on plant-derived secondary metabolites (PSMs). According to some researchers, new MDR (Multi-Drug Resistant) antibiotics may one day be developed due to the adaptability of secondary metabolites. Identifying plant metabolites that can treat a wide range of viral infections was one of the study's aims. Many natural medications that could be recommended for the treatment of COVID-19 were discovered as a result of this research, including remedies from plant families, viral candidates that are susceptible, antiviral assays, and mechanisms of therapeutic action. The findings of this study will inspire further research and speed up the development of new antiviral plant-based medications.

Anti-respiratory syncytial virus and anti-herpes simplex virus activity of six Tanzanian medicinal plants with extended studies of Erythrina abyssinica stem bark

ETHNOPHARMACOLOGICAL RELEVANCE

Except for few highly pathogenic viruses, no antiviral drug has been approved for treatment of viral infections in humans. Plant extracts, selected based on their ethno-medical use, represent an important source of compounds for the development of novel candidate antiviral drugs. This especially concerns plants with ethnomedical records on their use in treatment of viral infections.

AIM OF THE STUDY

To identify and document medicinal plants used by traditional health practitioners (THPs) for treatment of respiratory infections and muco-cutaneous lesions in order to study their antiviral activity including identification of active components and elucidation of mode of antiviral activity.

MATERIALS AND METHODS

The ethno-medical survey was performed in the Kagera region of Tanzania. The THPs were asked for plants used for treatment of signs and symptoms of respiratory infections and watery muco-cutaneous blisters in oral and genital regions. The plants identified were successively extracted with n-hexane, ethyl acetate and water, and the extracts assayed for anti-respiratory syncytial virus (RSV), anti-herpes simplex virus 2 (HSV-2), and anti-human parainfluenza virus 2 (HPIV-2) activity in cultured cells. Antiviral components were separated by ethanol precipitation and CL-6B chromatography, and the mode of antiviral activity elucidated by the time-of-addition assay and selection for the virus variants resistant to antiviral plant extract.

RESULTS

THPs identified fifteen plants used for treatment of respiratory infections and muco-cutaneous blisters. The water extract, but not n-hexane or ethyl acetate extracts, of six of these plants including Erythrina abyssinica stem bark, inhibited infectivity of two glycosaminoglycan-binding viruses i.e., RSV and HSV-2 but not the sialic acid binding HPIV-2. An activity-guided separation revealed that antiviral component(s) of water extract of E. abyssinica could be precipitated with ethanol. This sample potently and selectively inhibited RSV and HSV-2 infectivity in cultured cells with IC50 values of 2.1 μg/ml (selectivity index >476) and 0.14 μg/ml (selectivity index >7143) respectively. The sample exhibited inhibitory effect on the virus attachment to and entry into the cells by directly targeting the viral particles. Indeed, 10 consecutive virus passages in HEp-2 cells in the presence of this extract selected for a resistant RSV variant lacking the attachment, viral membrane-associated, G protein due to a stop codon at amino acid residue 33 (Leu33stop). Fractionation of the E. abyssinica extract on a CL-6B column revealed that anti-RSV and HSV-2 activity correlated with carbohydrate content. The most pronounced antiviral activity was associated with a carbohydrate containing ingredient of molecular mass of <5 kDa, which may polymerize to antiviral composites of up to 410 kDa.

CONCLUSIONS

Altogether, the water extract of six medicinal plants showed anti-RSV and anti-HSV-2 activities. Extended studies of the stem bark of E. abyssinica identified antiviral components that potently and selectively inhibited infectivity of free RSV and HSV-2 particles, a feature of importance in topical treatment of these infections. This observation confirms ethno-medical information concerning the use of E. abyssinica extract for treatment of respiratory infections and herpetic lesions.

Bulgarian Medicinal Extracts as Natural Inhibitors with Antiviral and Antibacterial Activity

Background: Bulgaria is a country with a wide range of medicinal plants, with uses in traditional medicine dating back for centuries. Methods: Disc diffusion assay was used to evaluate the antimicrobial activity of the plant extracts. A cytopathic effect inhibition test was used for the assessment of the antiviral activity of the extracts. The virucidal activity of the extracts, their influence on the stage of viral adsorption, and their protective effect on uninfected cells were reported using the end-point dilution method, and Δlgs was determined as compared to the untreated controls. Results: The results of the study reveal that the antibacterial potential of G. glabra and H. perforatum extracts in Gram-positive bacteria is more effective than in Gram-negative bacteria. When applied during the replication of HSV-1 and HCov-OC-43, only some of the extracts showed weak activity, with SI between 2 to 8.5. Almost all tested extracts inhibited the extracellular virions of the studied enveloped viruses (HSV-1 and HCov-OC-43) to a greater extent than of the non-enveloped viruses (PV-1 and HAdV-5). They inhibited the stage of viral adsorption (HSV-1) in the host cell (MDBK) to varying degrees and showed a protective effect on healthy cells (MDBK) before they were subjected to viral invasion (HSV-1). Conclusion: The antipathogenic potential of extracts of H. perforatum and G. glabra suggests their effectiveness as antimicrobial agents. All 13 extracts of the Bulgarian medicinal plants studied can be used to reduce viral yield in a wide range of viral infections.

Structure-based pharmacophore modeling, virtual screening approaches to identifying the potent hepatitis C viral protease and polymerase novel inhibitors

Hepatitis C is an infectious disease that leads to acute and chronic liver illnesses. Currently, there are no effective vaccines against this deadly virus. Direct acting antiviral (DAA) drugs are given in the combination with ribavirin and pegylated interferon which lead to adverse effects. Through in silico analysis, the structure-based docking study was performed against NS3/4A protease and NS5B polymerase proteins of HCV. In the current study, multiple e-pharmacophore-based virtual screening methods such as HTVS, SP, and XP were carried out to screen natural compounds and enamine databases. Our result outcomes revealed that CID AE-848/13196185 and CID AE-848/36959205 compounds show good binding interactions with protease protein. In addition, CID 15081408 and CID 173568 show better binding interactions with the polymerase protein. Further to validate the docking results, we performed molecular dynamics simulation for the top hit compounds bound with protease and polymerase proteins to illustrate conformational differences in the stability compared with the active site of the cocrystal inhibitor. Thus, the current study emphasizes these compounds could be an effective drug to treat HCV.

Medicinal Herbs in the Relief of Neurological, Cardiovascular, and Respiratory Symptoms after COVID-19 Infection A Literature Review

COVID-19 infection causes complications, even in people who have had a mild course of the disease. The most dangerous seem to be neurological ailments: anxiety, depression, mixed anxiety–depressive (MAD) syndromes, and irreversible dementia. These conditions can negatively affect the respiratory system, circulatory system, and heart functioning. We believe that phytotherapy can be helpful in all of these conditions. Clinical trials confirm this possibility. The work presents plant materials (Valeriana officinalis, Melissa officinalis, Passiflora incarnata, Piper methysticum, Humulus lupulus, Ballota nigra, Hypericum perforatum, Rhodiola rosea, Lavandula officinalis, Paullinia cupana, Ginkgo biloba, Murraya koenigii, Crataegus monogyna and oxyacantha, Hedera helix, Polygala senega, Pelargonium sidoides, Lichen islandicus, Plantago lanceolata) and their dominant compounds (valeranon, valtrate, apigenin, citronellal, isovitexin, isoorientin, methysticin, humulone, farnesene, acteoside, hypericin, hyperforin, biapigenin, rosavidin, salidroside, linalool acetate, linalool, caffeine, ginkgolide, bilobalide, mihanimbine, epicatechin, hederacoside C,α-hederine, presegenin, umckalin, 6,7,8-trixydroxybenzopyranone disulfate, fumaroprotocetric acid, protolichesteric acid, aucubin, acteoside) responsible for their activity. It also shows the possibility of reducing post-COVID-19 neurological, respiratory, and cardiovascular complications, which can affect the functioning of the nervous system.

Identification of phytochemicals from Eclipta alba and assess their potentiality against Hepatitis C virus envelope glycoprotein: virtual screening, docking, and molecular dynamics simulation study

Hepatitis C virus has a major role in spreading chronic liver disease and hepatocellular carcinoma. Factors such as high costs, pharmacological side effects, and the development of drug resistance strains require the development of new and potentially effective antiviral to treat the various stages of Hepatitis C. Bioactive chemicals have been extracted from medicinal plants and are utilized by humans for the goal of maintaining a healthy lifestyle. The goal of this work is to recognize phytochemicals from Eclipta alba and assess their potentiality activity against the hepatitis C virus envelope glycoprotein using in silico approaches. Phytochemicals from Eclipta alba were virtually screened by Auto dock raccoon and 12 compounds were selected for molecular docking to probe the active binding site. The top two compounds based on the binding score like ecliptalbine and oleanolic acid with HCV E2 glycoprotein exhibit binding energy -8.88 and -8.02 kcal/mol, respectively. The chemicals' usefulness was reinforced by positive pharmacokinetic data. The phytocompounds were identified as potent HCV inhibitors based on the drug likeness and ADMET properties. Both ecliptalbine and oleanolic acid underwent molecular dynamics simulations to determine features such as RMSD, RMSF, SASA, hydrogen-bond number, and MM-PBSA-based binding free energy. From the molecular docking and molecular dynamics simulation study revealed that oleanolic acid obtained from Eclipta alba can be used as inhibitors against Hepatitis C. The identified inhibitor from our study will be study in vitro and in vivo studies to check their efficacy against Hepatitis C.Communicated by Ramaswamy H. Sarma.

Antiviral Activity of Medicinal Plants against Human Coronavirus: a systematic scoping review of and experimentations

OBJECTIVE

To investigate the and studies of natural compounds and medicinal plants with anti-coronavirus activity.

METHODS

A systematic review was performed based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Animal Research: Reporting of experiments guidelines to find data for medicinal plants and natural products effective against human coronaviruses in or studies. Studies published up to September 6, 2020 were included. Studies ( or ) reporting the effect of medicinal plants and natural products or their derivatives on human coronavirus were included RESULTS: Promising anti-coronavirus effects are seen with different herbal compounds like some diterpenoids, sesquiterpenoids, and three compounds in tea with 3CLpro inhibiting effect of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV); Hirsutenone, Six cinnamic amides and bavachinin are PLpro inhibitors and Tanshinones are active on both 3CLpro and PLpro. Some flavonoid compounds of Citrus fruits act on Immun-oregulation and target angiotensin-converting enzyme 2 which is used by SARS-COV for entry. Virus helicase is possibly inhibited by two compounds myricetin and scutellarein.

CONCLUSION

This review shows that complementary medicine have the potential for new drug discovery against coronavirus. Further research is needed before definitive conclusions can be made concerning the safety and efficacy of the use of these medicinal plants.

Multi-target potential of Indian phytochemicals against SARS-CoV-2: A docking, molecular dynamics and MM-GBSA approach extended to Omicron B.1.1.529

BACKGROUND

SARS-CoV-2, an emerged strain of corona virus family became almost serious health concern worldwide. Despite vaccines availability, reports suggest the occurrence of SARS-CoV-2 infection even in a vaccinated population. With frequent evolution and expected multiple COVID-19 waves, improved preventive, diagnostic, and treatment measures are required. In recent times, phytochemicals have gained attention due to their therapeutic characteristics and are suggested as alternative and complementary treatments for infectious diseases. This present study aimed to identify potential inhibitors against reported protein targets of SARS-CoV-2.

METHODOLOGY

We computationally investigated potential SARS-CoV-2 protein targets from the literature and collected druggable phytochemicals from Indian Medicinal Plants, Phytochemistry and Therapeutics (IMPPAT) database. Further, we implemented a systematic workflow of molecular docking, dynamic simulations and generalized born surface area free-energy calculations (MM-GBSA).

RESULTS

Extensive literature search and assessment of 1508 articles identifies 13 potential SARS-CoV-2 protein targets. We screened 501 druggable phytochemicals with proven biological activities. Analysis of 6513(501 *13) docked phytochemicals complex, 26 were efficient against SARS-CoV-2. Amongst, 4,8-dihydroxysesamin and arboreal from Gmelina arborea were ranked potential against most of the targets with binding energy ranging between - 10.7 to - 8.2 kcal/mol. Additionally, comparative docking with known drugs such as arbidol (-6.6 to -5.1 kcal/mol), favipiravir (-5.5 to -4.5 kcal/mol), hydroxychloroquine (-6.5 to -5.1 kcal/mol), and remedesivir (-8.0 to -5.3 kcal/mol) revealed equal/less affinity than 4,8-dihydroxysesamin and arboreal. Interestingly, the nucleocapsid target was found commonly inhibited by 4,8-dihydroxysesamin and arboreal. Molecular dynamic simulation and Molecular mechanics generalized born surface area (MM-GBSA)calculations reflect that both the compounds possess high inhibiting potential against SARS-CoV-2 including the recently emerged Omicron variant (B.1.1.529).

CONCLUSION

Overall our study imparts the usage of phytochemicals as antiviral agents for SARS-CoV-2 infection. Additional in vitro and in vivo testing of these phytochemicals is required to confirm their potency.

Multifunctional role of exosomes in viral diseases: From transmission to diagnosis and therapy

Efforts to discover antiviral drugs and diagnostic platforms have intensified to an unprecedented level since the outbreak of COVID-19. Nano-sized endosomal vesicles called exosomes have gained considerable attention from researchers due to their role in intracellular communication to regulate the biological activity of target cells through cargo proteins, nucleic acids, and lipids. According to recent studies, exosomes play a vital role in viral diseases including covid-19, with their interaction with the host immune system opening the door to effective antiviral treatments. Utilizing the intrinsic nature of exosomes, it is imperative to elucidate how exosomes exert their effect on the immune system or boost viral infectivity. Exosome biogenesis machinery is hijacked by viruses to initiate replication, spread infection, and evade the immune response. Exosomes, however, also participate in protective mechanisms by triggering the innate immune system. Besides that, exosomes released from the cells can carry a robust amount of information about the diseased state, serving as a potential biomarker for detecting viral diseases. This review describes how exosomes increase virus infectivity, act as immunomodulators, and function as a potential drug delivery carrier and diagnostic biomarker for diseases caused by HIV, Hepatitis, Ebola, and Epstein-Barr viruses. Furthermore, the review analyzes various applications of exosomes within the context of COVID-19, including its management.

Hypericum perforatum and Its Ingredients Hypericin and Pseudohypericin Demonstrate an Antiviral Activity against SARS-CoV-2

For almost two years, the COVID-19 pandemic has constituted a major challenge to human health, particularly due to the lack of efficient antivirals to be used against the virus during routine treatment interventions. Multiple treatment options have been investigated for their potential inhibitory effect on SARS-CoV-2. Natural products, such as plant extracts, may be a promising option, as they have shown an antiviral activity against other viruses in the past. Here, a quantified extract of Hypericum perforatum was tested and found to possess a potent antiviral activity against SARS-CoV-2. The antiviral potency of the extract could be attributed to the naphtodianthrones hypericin and pseudohypericin, in contrast to other tested ingredients of the plant material, which did not show any antiviral activity. Hypericum perforatum and its main active ingredient hypericin were also effective against different SARS-CoV-2 variants (Alpha, Beta, Delta, and Omicron). Concerning its mechanism of action, evidence was obtained that Hypericum perforatum and hypericin may hold a direct virus-blocking effect against SARS-CoV-2 virus particles. Taken together, the presented data clearly emphasize the promising antiviral activity of Hypericum perforatum and its active ingredients against SARS-CoV-2 infections.

Application of the Integrated Supercritical Fluid Extraction–Impregnation Process (SFE-SSI) for Development of Materials with Antiviral Properties

The integrated supercritical fluid extraction–impregnation process (SFE-SSI) was performed to fabricate material with antiviral properties against the herpes simplex virus (HSV). Cotton gauze and starch/chitosan polymer films (SCF) were impregnated with components extracted from Melissa officinalis at 10 MPa and 40 °C using a green medium, supercritical carbon dioxide (scCO2). The influences of the processing mode regarding the flow of the supercritical fluid through the system, and the mass ratio of the plant material and the solid carrier, on the impregnation yield of M. officinalis extract were studied. The results revealed that the introduction of a fresh amount of CO2 into the system enabled the highest impregnation yield of 2.24% for cotton gauze and 8.71% for SCF. The presence of M. officinalis extract on the surface of both impregnated cotton gaze and SCF was confirmed by FTIR and GC analyses after the re-extraction of the impregnated samples. The M. officinalis impregnated materials showed a strong inhibitory effect against Bovine herpesvirus type 1 (BHV-1).

A Systematic Review on Curcumin and Anti-Plasmodium berghei Effects

BACKGROUND

Turmeric (Curcuma longa L.) is a popular spice, containing curcumin that is responsible for its therapeutic effects. Curcumin with anti-inflammatory, antioxidant, anti-cancer, and antimicrobial activities has led to a lot of research focusing on it over the years. This systematic review aimed to evaluate researches on anti-Plasmodium berghei activity of curcumin and its derivatives.

METHODS

Our study was performed according to PRISMA guidelines and was recorded in the database of systematic review and preclinical meta-analysis of CAMARADESNC3Rs (SyRF). The search was performed in five databases, namely Scopus, PubMed, Web of Science, EMBASE, and Google Scholar from 2010 to 2020. The following keywords were searched: "Plasmodium berghei", "Medicinal Plants", "Curcumin", "Concentration", Animals kind", "Treatment Durations", "Routes of Administration" and "in vivo".

RESULTS

Of the 3,500 papers initially obtained, 14 articles were reliable and were thus scrutinized. Animal models were included in all studies. The most commonly used animal strain were Albino (43%) followed by C57BL/6 (22%). The other studies used various murine strains, including BALB/c (14%) and ICR (7%). Two (14%) studies did not mention the strain of animal model used. Curcumin alone or in combination with other compounds depending on the dose used, route of administration, and animal model showed a moderate to strong anti-Plasmodium berghei effect.

CONCLUSION

According to the studies, curcumin has anti-malarial effects on Plasmodium berghei and, however, its effect on human Plasmodium is unclear. Due to the side effects and drug resistance of current drugs in the treatment of human malaria, the use of new compounds with few or no side effects such as curcumin is recommended as an alternative or complementary treatment.

Metabolomic profile of medicinal plants with anti-RVFV activity

Twenty medicinal plants with previously established anti-viral activity against a wild-type RVFV were further investigated using bio-chemometric and analytical techniques. The aim being to identify compounds common in plants with anti-RVFV activity, potentially being the major contributors to the anti-viral effect. Proton nuclear magnetic resonance (¹H NMR) spectroscopy coupled with multivariate data analysis (MVDA) was applied to characterize metabolite profiles of twenty antiviral medicinal plants. Discrimination and prediction of metabolome data of active anti-RVFV from the less-active samples was assessed using the multivariate statistical models by constructing a robust principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) regression model. Annotation of metabolites in the samples with higher activity were performed by Chenomx software and the compounds confirmed using Ultra-High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry (UHPLC-qTOF-MS). Both the PCA and OPLS-DA score plots showed clustering of samples; however, the OPLS-DA plot indicated a clear separation among active and less-active samples. Metabolic biomarkers were screened by p-value < 0.05 and variable importance in the projection (VIP) value >1 and S-plot. Among active samples, the most prominent metabolites putatively identified by NMR include trigonelline, vanillic acid, fumarate, chlorogenic acid, ferulate, and formate. The presence of the compounds were confirmed by UHPLC-qTOF-MS, and two hydroxylated fatty acids were additionally detected indicated by peaks at m/z 293.2116 and m/z 295.2274 13S-Hydroxy-9Z,11E,15Z-octadecatrienoic acid and 13-Hydroxy-9Z,11E-octadecadienoic acid were annotated for the first time in all the antiviral active samples and are considered potential metabolites responsible for the antiviral activity. The study provides a metabolomic profile of anti-RVFV plant extracts and report for the first time the presence of hydroxylated fatty acids 13S-Hydroxy-9Z,11E,15Z-octadecatrienoic acid and 13-Hydroxy-9Z,11E-octadecadienoic acid, present in all the tested medicinal plants with high anti-RVFV activity and is a potential target for the future development of antiviral therapeutic agents.

Phytochemical Analysis Both of Water and Ethanol Extract from Some Herbs Combinations, Nanoemulsion Formulation, and Antioxidant Effects

AIM: The purpose of this study was to analyze the phenolic content and antioxidant activity of both water and ethanol extracts of a combination of several herbs (Phyllanthus urinaria, Andrographis paniculata, Curcuma longa, Zingiber officinale, Citrus limon, and Cymbopogon citratus), as well as product development in the form of nanoemulsions. METHODS: The research was conducted by making three combinations of herbs mixtures with various compositions (Formulas A, B, and C). The combined herbs powder was then made in the form of water and ethanol extracts. The ethanol extract of each herbal combination was then made also in the form of a nanoemulsion by spontaneous emulsion. RESULTS: The ethanol extract of each herbs combination contained higher phenolic compounds and antioxidant activity than the water extract. The nanoemulsion product of the combined herbs ethanol extract had a particle size of 21.1; 34.9; and 50.7 nm and showed high antioxidant activity. CONCLUSION: The combined several herbs (P. urinaria, A. paniculata, C. longa, Z. officinale, C. limon, and C. citratus) ethanol extract and its nanoemulsion products have the potential to be developed as natural antioxidants.

Plant-derived lignans as potential antiviral agents: a systematic review

Medicinal plants are one of the most important sources of antiviral agents and lead compounds. Lignans are a large class of natural compounds comprising two phenyl propane units. Many of them have demonstrated biological activities, and some of them have even been developed as therapeutic drugs. In this review, 630 lignans, including those obtained from medicinal plants and their chemical derivatives, were systematically reviewed for their antiviral activity and mechanism of action. The compounds discussed herein were published in articles between 1998 and 2020. The articles were identified using both database searches (e.g., Web of Science, Pub Med and Scifinder) using key words such as: antiviral activity, antiviral effects, lignans, HBV, HCV, HIV, HPV, HSV, JEV, SARS-CoV, RSV and influenza A virus, and directed searches of scholarly publisher's websites including ACS, Elsevier, Springer, Thieme, and Wiley. The compounds were classified on their structural characteristics as 1) arylnaphthalene lignans, 2) aryltetralin lignans, 3) dibenzylbutyrolactone lignans, 4) dibenzylbutane lignans, 5) tetrahydrofuranoid and tetrahydrofurofuranoid lignans, 6) benzofuran lignans, 7) neolignans, 8) dibenzocyclooctadiene lignans and homolignans, and 9) norlignans and other lignoids. Details on isolation and antiviral activities of the most active compounds within each class of lignan are discussed in detail, as are studies of synthetic lignans that provide structure-activity relationship information.