Anti-influenza agents from plants and traditional Chinese medicine

The protective effect of Lonicera japonica Thunb. against lipopolysaccharide-induced acute lung injury in mice: Modulation of inflammation, oxidative stress, and ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Various components of Lonicera japonica Thunb. (LJT) exhibit pharmacological activities, including anti-inflammatory and antioxidant effects. Nevertheless, the relationship between LJT and ferroptosis remains largely unexplored.

AIM OF THE STUDY

The purpose of this research was to look into the role of LJT in regulating LPS-induced ferroptosis in ALI and to compare the effects of different parts of LJT.

MATERIALS AND METHODS

We established a mice ALI model by treating with LPS. Administered mice with different doses of Lonicerae Japonicae Flos (LJF), Lonicera Japonica Leaves (LJL) and Lonicerae Caulis (LRC) extracts, respectively. The levels of IL-6, IL-1β, TNF-α, IL-4, IL-10, and PGE2 in bronchoalveolar lavage fluid (BALF) were measured using enzyme-linked immunosorbent assay. Furthermore, the concentrations of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), and total ferrous ions (Fe2+) in lung tissues were evaluated. Hematoxylin and eosin staining was conducted to examine the morphological structure of lung tissues. Transmission electron microscopy was used to investigate the ultrastructural morphology of mitochondria. Furthermore, the effects of LJT were evaluated via immunohistochemical staining, western blotting, and quantitative real-time polymerase chain reaction analyses. Finally, employing molecular docking and molecular dynamics research techniques, we aimed to identify crucial components in LJT that might inhibit ferroptosis by targeting nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione peroxidase 4 (GPX4).

RESULTS

We observed that pretreatment with LJT significantly mitigated LPS-induced lung injury and suppressed ferroptosis. This was supported by reduced accumulation of pro-inflammatory cytokines, ROS, MDA, and Fe2+, along with increased levels of anti-inflammatory cytokines, SOD, GSH, Nrf2, and GPX4 in the lung tissues of ALI mice. Luteolin-7-O-rutinoside, apigenin-7-O-rutinoside, and amentoflavone in LJT exhibit excellent docking effects with key targets of ferroptosis, Nrf2 and GPX4.

CONCLUSIONS

Pretreatment with LJT may alleviate LPS-induced ALI, possibly by suppressing ferroptosis. Our initial results indicate that LJT activates the Nrf2/GPX4 axis, providing protection against ferroptosis in ALI. This finding offers a promising therapeutic candidate for ALI treatment.

Two undescribed coumarins from Hansenia weberbaueriana

Two previously undescribed coumarins (1 and 2) were isolated from the root of Hansenia weberbaueriana which have been used to cure inflammatory diseases over thousands of years by Chinese. The structures of new findings were confirmed by comprehensive analyses of spectral evidences in HRESIMS, 1D and 2D NMR combined with chemical calculations. Compounds 1 and 2 exhibited potential anti-inflammatory properties by reducing the mRNA expression levels of TNF-α, IL-6 and IL-1β in lipopolysaccharide (LPS)-induced RAW264.7 macrophages at a concentration of 15 μM.

Comparing factors influencing seasonal influenza vaccine acceptance and intentions among Chinese university students residing in China and UK: A cross-sectional study

University students, who face an elevated risk of influenza due to close living quarters and frequent social interactions, often exhibit low vaccine uptake rates. This issue is particularly pronounced among Chinese students, who encounter unique barriers related to awareness and access, emphasizing the need for heightened attention to this problem within this demographic. This cross-sectional study conducted in May-June 2022 involved 1,006 participants (404 in the UK, 602 in Mainland China) and aimed to explore and compare the factors influencing influenza vaccine acceptance and intentions between Chinese university students residing in the UK (C-UK) and Mainland China (C-M). The study employed a self-administered questionnaire based on the Theoretical Domains Framework and Capability Opportunity Motivation-Behavior model. Results revealed that approximately 46.8% of C-UK students received the influenza vaccine in the past year, compared to 32.9% of C-M students. More than half in both groups (C-UK: 54.5%, C-M: 58.1%) had no plans for vaccination in the upcoming year. Knowledge, belief about consequences, and reinforcement significantly influenced previous vaccine acceptance and intention in both student groups. Barriers to vaccination behavior included insufficient knowledge about the influenza vaccine and its accessibility and the distance to the vaccine center. Enablers included the vaccination behavior of individuals within their social circles, motivation to protect others, and concerns regarding difficulties in accessing medical resources during the COVID-19 pandemic. The findings of this study offer valuable insights for evidence-based intervention design, providing evidence for healthcare professionals, policymakers, and educators working to enhance vaccination rates within this specific demographic.

Calculation, knowledge, and identity: Dimensions of trust when making COVID-19 vaccination choices in China

Vaccine hesitancy threatens the response to the COVID-19 pandemic and to other infectious disease outbreaks globally. Fostering trust has been highlighted as a critical factor in addressing vaccine hesitancy and expanding vaccine coverage, but qualitative exploration of trust in the context of vaccination remains limited. We contribute to filling this gap by providing a comprehensive qualitative analysis of trust in the context of COVID-19 vaccination in China. We conducted 40 in-depth interviews with Chinese adults in December 2020. During data collection, trust emerged as a highly salient topic. Interviews were audio-recorded, transcribed verbatim, translated into English, and analyzed with a combination of inductive and deductive coding. Following established trust literature, we differentiate between three types of trust - calculation-based trust, knowledge-based trust, and identity-based trust - which we grouped across components of the health system, as informed by the WHO's building blocks. Our results highlight how participants attributed their level of trust in COVID-19 vaccines to their trust in the medical technology itself (based on assessing risks and benefits or previous vaccination experiences), the service delivery and health workforce (informed by past experiences with health providers and their role throughout the pandemic), and leadership and governance (drawing on notions of government performance and patriotism). Reducing negative impact from past vaccine controversies, increasing the credibility of pharmaceutical companies, and fostering clear communication are identified as important channels for facilitating trust. Our findings emphasize a strong need for comprehensive information on COVID-19 vaccines and increased promotion of vaccination by credible figures.

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.

Network pharmacology associated anti-influenza mechanism research of Qingjie-Tuire Granule via STAT1/3 signaling pathway

Qingjie-Tuire (QT) granule was approved for clinical use and its combination was reported to treat influenza infection. To explore its active component and mechanism, the components of QT granule were retrieved from UPLC-UC-Q-TOF/MS analysis. The genes corresponding to the targets were retrieved using GeneCards and TTD database. The herb-compound-target network was constructed by Cytoscape. The target protein-protein interaction network was built using STRING database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of QT granule to IAV were performed for further study. The regulation to different signaling transduction events and cytokine/chemokine expression of QT granule was evaluated using Western blotting and real-time qPCR. Totally, 47 compounds were identified and effect of QT granule on cell STAT1/3 signaling pathways was confirmed by A549 cell model. The efficiency of QT granule on host cell contributes to its clinical application and mechanism research.

A systemic review on medicinal plants and their bioactive constituents against avian influenza and further confirmation through in-silico analysis

Background

Avian influenza or more commonly known as bird flu is a widespread infectious disease in poultry. This review aims to accumulate information of different natural plant sources that can aid in combating this disease. Influenza virus (IV) is known for its ability to mutate and infect different species (including humans) and cause fatal consequences.

Methods

Total 33 plants and 4 natural compounds were identified and documented. Molecular docking was performed against the target viral protein neuraminidase (NA), with some plant based natural compounds and compared their results with standard drugs Oseltamivir and Zanamivir to obtain novel drug targets for influenza in chickens.

Results

It was seen that most extracts exhibit their action by interacting with viral hemagglutinin or neuraminidase and inhibit viral entry or release from the host cell. Some plants also interacted with the viral RNA replication or by reducing proinflammatory cytokines. Ethanol was mostly used for extraction. Among all the plants Theobroma cacao, Capparis Sinaica Veil, Androgarphis paniculate, Thallasodendron cillatum, Sinularia candidula, Larcifomes officinalis, Lenzites betulina, Datronia molis, Trametes gibbose exhibited their activity with least concentration (below 10 μg/ml). The dockings results showed that some natural compounds (5,7- dimethoxyflavone, Aloe emodin, Anthocyanins, Quercetin, Hemanthamine, Lyocrine, Terpenoid EA showed satisfactory binding affinity and binding specificity with viral neuraminidase compared to the synthetic drugs.

Conclusion

This review clusters up to date information of effective herbal plants to bolster future influenza treatment research in chickens. The in-silico analysis also suggests some potential targets for future drug development but these require more clinical analysis.

Rapid screening of neuraminidase inhibitors using an at-line nanofractionation platform involving parallel oseltamivir-sensitive/resistant neuraminidase bioassays

In this study, an advanced at-line nanofractionation based screening platform was developed to screen potential neuraminidase inhibitors (NAIs) from Lonicera japonica Thunb by involving two parallel bioassays, for determining both oseltamivir-sensitive neuraminidase (NAS) and oseltamivir-resistant neuraminidase (NAR) inhibitory activities. 20 potential NAIs with both NAS and NAR inhibitory effects were screened from Lonicera japonica Thunb and identified by mass spectrometer, including 11 phenolic acids, 8 flavonoids and one iridoid glycoside. The proposed at-line nanofractionation based screening platform for NAIs was also used to rapidly screen nine batches of water extracts of Lonicera japonica Thunb or its similar species. Clear differences in the number and content of active components were easily observed, demonstrating that the proposed method possesses great potential for the quality control of herb medicines.

Research progress on the effect of traditional Chinese medicine on the activation of PRRs-mediated NF-κB signaling pathway to inhibit influenza pneumonia

Influenza pneumonia has challenged public health and social development. One of the hallmarks of severe influenza pneumonia is overproduction of pro-inflammatory cytokines and chemokines, which result from the continuous activation of intracellular signaling pathways, such as the NF-κB pathway, mediated by the interplay between viruses and host pattern recognition receptors (PRRs). It has been reported that traditional Chinese medicines (TCMs) can not only inhibit viral replication and inflammatory responses but also affect the expression of key components of PRRs and NF-κB signaling pathways. However, whether the antiviral and anti-inflammatory roles of TCM are related with its effects on NF-κB signaling pathway activated by PRRs remains unclear. Here, we reviewed the mechanism of PRRs-mediated activation of NF-κB signaling pathway following influenza virus infection and summarized the influence of anti-influenza TCMs on inflammatory responses and the PRRs/NF-κB signaling pathway, so as to provide better understanding of the mode of action of TCMs in the treatment of influenza pneumonia.

Antiviral Potential of Natural Resources against Influenza Virus Infections

Influenza is a severe contagious disease caused by influenza A and B viruses. The WHO estimates that annual outbreaks lead to 3-5 million severe infections of which approximately 10% lead to the death of the patient. While vaccination is the cornerstone of prevention, antiviral drugs represent the most important treatment option of acute infections. Only two classes of drugs are currently approved for the treatment of influenza in numerous countries: M2 channel blockers and neuraminidase inhibitors. In some countries, additional compounds such as the recently developed cap-dependent endonuclease inhibitor baloxavir marboxil or the polymerase inhibitor favipiravir are available. However, many of these compounds suffer from poor efficacy, if not applied early after infection. Furthermore, many influenza strains have developed resistances and lost susceptibility to these compounds. As a result, there is an urgent need to develop new anti-influenza drugs against a broad spectrum of subtypes. Natural products have made an important contribution to the development of new lead structures, particularly in the field of infectious diseases. Therefore, this article aims to review the research on the identification of novel lead structures isolated from natural resources suitable to treat influenza infections.

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.

Aptamer-Based High-Throughput Screening Model for Efficient Selection and Evaluation of Natural Ingredients against SGIV Infection

Singapore grouper iridovirus (SGIV) causes high economic losses in mariculture. Effective drugs for managing SGIV infection are urgently required. Medicinal plant resources are rich in China. Medicinal plants have a long history and significant curative effects in the treatment of many diseases. Reverse-transcription quantitative real-time PCR is the most commonly used method for detecting virus infection and assessing antiviral efficacy with high accuracy. However, their applications are limited due to high reagent costs and complex time-consuming operations. Aptamers have been applied in some biosensors to achieve the accurate detection of pathogens or diseases through signal amplification. This study aimed to establish an aptamer-based high-throughput screening (AHTS) model for the efficient selection and evaluation of medicinal plants components against SGIV infection. Q2-AHTS is an expeditious, rapid method for selecting medicinal plant drugs against SGIV, which was characterized as being dram, high-speed, sensitive, and accurate. AHTS strategy reduced work intensity and experimental costs and shortened the whole screening cycle for effective ingredients. AHTS should be suitable for the rapid selection of effective components against other viruses, thus further promoting the development of high-throughput screening technology.

Phytochemistry and Biological Activity of Medicinal Plants in Wound Healing: An Overview of Current Research

Wound healing is a complicated process, and the effective management of wounds is a major challenge. Natural herbal remedies have now become fundamental for the management of skin disorders and the treatment of skin infections due to the side effects of modern medicine and lower price for herbal products. The aim of the present study is to summarize the most recent in vitro, in vivo, and clinical studies on major herbal preparations, their phytochemical constituents, and new formulations for wound management. Research reveals that several herbal medicaments have marked activity in the management of wounds and that this activity is ascribed to flavonoids, alkaloids, saponins, and phenolic compounds. These phytochemicals can act at different stages of the process by means of various mechanisms, including anti-inflammatory, antimicrobial, antioxidant, collagen synthesis stimulating, cell proliferation, and angiogenic effects. The application of natural compounds using nanotechnology systems may provide significant improvement in the efficacy of wound treatments. Increasing the clinical use of these therapies would require safety assessment in clinical trials.

A Review on the Potential Species of the Zingiberaceae Family with Anti-viral Efficacy Towards Enveloped Viruses

Natural products are a great wellspring of biodiversity for finding novel antivirals, exposing new interactions between structure and operation and creating successful defensive or remedial methodologies against viral diseases. The members of Zingiberaceae traditional plant and herbal products have robust anti-viral action, and their findings will further lead to the production of derivatives and therapeutic. Additionally, it highlights the insight of utilizing these phytoextracts or their constituent compounds as an emergency prophylactic medicine during the pandemic or endemic situations for novel viruses. In this connection, this review investigates the potential candidates of the Zingiberaceae family, consisting of bioactive phytocompounds with proven antiviral efficacy against enveloped viruses. The present study was based on published antiviral efficacy of Curcuma longa, Zingiber officinale, Kaempferia parviflora, Aframomum melegueta Elettaria cardamomum, Alpina Sps (belongs to the Zingiberaceae family) towards the enveloped viruses. The relevant data was searched in Scopus”, “Scifinder”, “Springer”, “Pubmed”, “Google scholar” “Wiley”, “Web of Science”, “Cochrane “Library”, “Embase”, Dissertations, theses, books, and technical reports. Meticulously articles were screened with the subject relevancy and categorized for their ethnopharmacological significance with in-depth analysis. We have comprehensively elucidated the antiviral potency of phytoextracts, major composition, key compounds, mode of action, molecular evidence, immunological relevance, and potential bioactive phytocompounds of these five species belonging to the Zingiberaceae family. Conveniently, these phytoextracts exhibited multimode activity in combating the dreadful enveloped viruses.

A hypothesis that Notopterol may be effective in COVID-19 via JAK/STAT and other signaling pathways

COVID-19 is a rapidly spreading disease, causing a global pandemic. It is circulating in multiple countries and causing a series of respiratory infections. Due to the uncertain safety and efficacy of the vaccines and lack of specific medicines, it's important to investigate new pharmacological procedures and find out new drugs that help us eradicate this pandemic. We suggest the hypothesis that Notopterol (NOT), the main Secondary metabolite of Notopterygium incisum Ting ex H.T (a common Chinese medicinal herb), may have the potential benefits on SARS-CoV2 infection for this reasons: (a) NOT exhibits anti-inflammatory, anticancer, and anti-angiogenic properties, (b) NOT indicates a significant reduction in cytokines and chemokines releasing including TNFa, IL-6, interferon-γ, which may decrease COVID-19 cytokine storm (c) NOT can suppress the expression of genes which leads to inflammation via Janus kinase/signal transducers and activators of transcription (JAK-STAT) signaling pathway. It is exactly acting like tocilizumab, (an approved drug against COVID-19) and (d) Notopterygium incisum has antiviral activity against influenza virus, it can reduce the viral-induced oxidative stress. By these explanations, it is hopeful that NOT may be effective in COVID-19 infections which needs further investigations to examine Notopterol as a beneficial agent against the SARS-CoV2 infection.

Efficacy of the commercial plant products acting against influenza-a review

Background

Influenza infection always poses a threat to human and animal health. Vaccines and antiviral drugs are recommended to deal with the situation. The drawback of these remedial agents made the scientist change their focus on an alternative therapy. The anti-influenza effects of plants have been extensively studied, and many pharmaceutical companies have prepared their products on this basis.

Main body

The present review documents the successfully launched anti-influenza commercial products. In specific, it exposes the scientifically validated and evidence-based supporting inhibitory action of influenza and its strains.

Conclusion

This review highlighted the efficacy of the commercial products which effectively combat influenza. It provides a complementary strategy to deal with the worst-case scenario of flu. Meanwhile, to face the emerging strains, brand new products are in great necessity besides prevailing and available drugs.

Kaempferol-induced GPER upregulation attenuates atherosclerosis via the PI3K/AKT/Nrf2 pathway

CONTEXT

The effect of kaempferol, a regulator of oestrogen receptors, on atherosclerosis (AS) and the underlying mechanism is elusive.

OBJECTIVE

To explore the effect and mechanism of kaempferol on AS.

METHODS AND MATERIALS

In vivo, C57BL/6 and apolipoprotein E (APOE)^-/- mice were randomly categorized into six groups (C57BL/6: control, ovariectomy (OVX), high-fat diet (HFD); APOE^-/-: OVX-HFD, OVX-HFD + kaempferol (50 mg/kg) and OVX-HFD + kaempferol (100 mg/kg) and administered with kaempferol for 16 weeks, intragastrically. Oil-Red and haematoxylin-eosin (HE) staining were employed to examine the effect of kaempferol. In vitro, human aortic endothelial cells (HAECs) were pre-treated with or without kaempferol (5, 10 or 20 μM), followed by administration with kaempferol and oxidized low-density lipoprotein (ox-LDL) (200 μg/mL). The effect of kaempferol was evaluated using flow cytometry, and TdT-mediated dUTP Nick-End Labelling (TUNEL).

RESULTS

In vivo, kaempferol (50 and 100 mg/kg) normalized the morphology of blood vessels and lipid levels and suppressed inflammation and apoptosis. It also activated the G protein-coupled oestrogen receptor (GPER) and PI3K/AKT/nuclear factor-erythroid 2-related factor 2 (Nrf2) pathways. In vitro, ox-LDL (200 μg/mL) reduced the cell viability to 50% (IC₅₀). Kaempferol (5, 10 or 20 μM) induced-GPER activation increased cell viability to nearly 10%, 19.8%, 30%, and the decreased cellular reactive oxygen species (ROS) generation (16.7%, 25.6%, 31.1%), respectively, consequently attenuating postmenopausal AS. However, the protective effects of kaempferol were blocked through co-treatment with si-GPER.

CONCLUSIONS

The beneficial effects of kaempferol against postmenopausal AS are associated with the PI3K/AKT/Nrf2 pathways, mediated by the activation of GPER.

3-Indoleacetonitrile Is Highly Effective in Treating Influenza A Virus Infection In Vitro and In Vivo

Influenza A viruses are serious zoonotic pathogens that continuously cause pandemics in several animal hosts, including birds, pigs, and humans. Indole derivatives containing an indole core framework have been extensively studied and developed to prevent and/or treat viral infection. This study evaluated the anti-influenza activity of several indole derivatives, including 3-indoleacetonitrile, indole-3-carboxaldehyde, 3-carboxyindole, and gramine, in A549 and MDCK cells. Among these compounds, 3-indoleacetonitrile exerts profound antiviral activity against a broad spectrum of influenza A viruses, as tested in A549 cells. Importantly, in a mouse model, 3-indoleacetonitrile with a non-toxic concentration of 20 mg/kg effectively reduced the mortality and weight loss, diminished lung virus titers, and alleviated lung lesions of mice lethally challenged with A/duck/Hubei/WH18/2015 H5N6 and A/Puerto Rico/8/1934 H1N1 influenza A viruses. The antiviral properties enable the potential use of 3-indoleacetonitrile for the treatment of IAV infection.

Viral UL8 Is Involved in the Antiviral Activity of Oleanolic Acid Against HSV-1 Infection

Herpes simplex virus type 1 (HSV-1) is highly prevalent in humans and can cause severe diseases, especially in immunocompromised adults and newborns, such as keratitis and herpes simplex encephalitis. At present, the clinical therapeutic drug against HSV-1 infection is acyclovir (ACV), and its extensive usage has led to the emergence of ACV-resistant strains. Therefore, it is urgent to explore novel therapeutic targets and anti-HSV-1 drugs. This study demonstrated that Oleanolic acid, a pentacyclic triterpenoid widely existing in natural product, had strong antiviral activity against both ACV-sensitive and -resistant HSV-1 strains in different cells. Mechanism studies showed that Oleanolic acid exerted its anti-HSV-1 activity in the immediate early stage of infection, which involved the dysregulation of viral UL8, a component of viral helicase-primase complex critical for viral replication. In addition, Oleanolic acid significantly ameliorated the skin lesions in an HSV-1 infection mediated zosteriform model. Together, our study suggested that Oleanolic acid could be a potential candidate for clinical therapy of HSV-1 infection-related diseases.

A New Drug Formula for Pneumonia and Severe Seasonal Flu; a Promising Drug for Eradicate COVID19

World Health Organization (WHO) well-known pleiotropic antiviral compounds.This study was designed to evaluate the effects of herbal drug combination in treatment of pneumonia, severe respiratory distress, and severe flu and recently for COVID19.The treatment phase includes 12 days period of herbal drug mixture (X) . Results showed the activity of herbal drug in eradication of COVID19, pneumonia and severe seasonalful.

Herbal immune-boosters: Substantial warriors of pandemic Covid-19 battle

Current scenario depicts that world has been clenched by COVID-19 pandemic. Inevitably, public health and safety measures could be undertaken in order to dwindle the infection threat and mortality. Moreover, to overcome the global menace and drawing out world from moribund stage, there is an exigency for social distancing and quarantines. Since December, 2019, coronavirus, SARS-CoV-2 (COVID-19) have came into existence and up till now world is still in the state of shock.At this point of time, COVID-19 has entered perilous phase, creating havoc among individuals, and this has been directly implied due to enhanced globalisation and ability of the virus to acclimatize at all conditions. The unabated transmission is due to lack of drugs, vaccines and therapeutics against this viral outbreak. But research is still underway to formulate the vaccines or drugs by this means, as scientific communities are continuously working to unravel the pharmacologically active compounds that might offer a new insight for curbing infections and pandemics. Therefore, the topical COVID-19 situation highlights an immediate need for effective therapeutics against SARS-CoV-2. Towards this effort, the present review discusses the vital concepts related to COVID-19, in terms of its origin, transmission, clinical aspects and diagnosis. However, here, we have formulated the novel concept hitherto, ancient means of traditional medicines or herbal plants to beat this pandemic.

Screening and evaluation of anti-SARS-CoV-2 components from Ephedra sinica by ACE2/CMC-HPLC-IT-TOF-MS approach

Traditional Chinese medicines played an important role in the treatment of COVID-19 in 2020. Ephedra sinica, one of the major constituent herbs of multi-component herbal formula, has been widely used to treat COVID-19 in China. However, its active components are still unclear. The objectives of this study are to screen and evaluate active components from the traditional Chinese medicine Ephedra sinica for the treatment of COVID-19. In our study, we established an ACE2/CMC bioaffinity chromatography model, and then developed an ACE2/CMC-HPLC-IT-TOF-MS system for the active compounds screening and identification from Ephedra sinica extract. We performed molecular docking and surface plasmon resonance (SPR) assays to assess the binding characteristics (binding mode and K_D value). We used CCK-8 staining to assess the toxicity of screened compounds, and also used SARS-CoV-2 pseudovirus to observe the viropexis effect of screened compounds in ACE2^h cells. In this current work, one fraction was fished out, separated and identified as ephedrine (EP), pseudoephedrine (PEP), and methylephedrine (MEP). Binding assays showed that the three compounds could bind with ACE2 in a special way to some amino acid residues, similar to the way SARS-CoV-2 bound with ACE2. Additionally, the three compounds, especially EP, can inhibit the entrance of SARS-CoV-2 spike pseudovirus into ACE2^h cells because they can reduce the entrance ratio of pseudovirus in the pseudovirus model. Overall, the ACE2/CMC-HPLC-IT-TOF-MS system was established and verified to be suitable for ACE2-targeted bioactive compound screening. EP, PEP, and MEP with ACE2-binding features were screened out from Ephedra sinica, and acted as blockers inhibiting SARS-CoV-2 spike pseudovirus entering ACE2^h cells.

Evidence that Ginkgo Biloba could use in the influenza and coronavirus COVID-19 infections

Coronavirus COVID-19 pandemic invades the world. Public health evaluates the incidence of infections and death, which should be reduced and need desperately quarantines for infected individuals. This article review refers to the roles of Ginkgo Biloba to reduce the risk of infection in the respiratory tract, the details on the epidemiology of corona COVID-19 and influenza, and it highlights how the Ginko Biloba could have been used as a novel treatment.Ginkgo Biloba can reduce the risk of infection by several mechanisms; these mechanisms involve Ginkgo Biloba contains quercetin and other constituents, which have anti-inflammatory and immune modulator effects by reducing pro-inflammatory cytokines concentrations. Cytokines cause inflammation which have been induced the injuries in lung lining.Some observational studies confirmed that Ginkgo Biloba reduced the risk of asthma, sepsis and another respiratory disease as well as it reduced the risk of cigarette smoking on respiratory symptoms. While other evidences suggested the characters of Ginkgo Biloba as an antivirus agent through several mechanisms. Ginkgolic acid (GA) can inhibit the fusion and synthesis of viral proteins, thus, it inhibit the Herpes Simplex Virus type1 (HSV-1), genome replication in Human Cytomegalovirus (HCMV) and the infections of the Zika Virus (ZIKV). Also, it inhibits the wide spectrum of fusion by inhibiting the three types of proteins that have been induced fusion as (Influenza A Virus [IAV], Epstein Barr Virus [EBV], HIV and Ebola Virus [EBOV]).The secondary mechanism of GA targeting inhibition of the DNA and protein synthesis in virus, greatly have been related to its strong effects, even afterward the beginning of the infection, therefore, it potentially treats the acute viral contaminations like (Measles and Coronavirus COVID-19). Additionally, it has been used topically as an effective agent on vigorous lesions including (varicella-zoster virus [VZV], HSV-1 and HSV-2). Ginkgo Biloba may be useful for treating the infected people with coronavirus COVID-19 through its beneficial effect. To assess those recommendations should be conducted with random control trials and extensive population studies.

Potential anti-influenza effective plants used in Turkish folk medicine: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Due to the outbreaks such as SARS, bird flu and swine flu, which we frequently encounter in our century, we need fast solutions with no side effects today more than ever. Due to having vast ethnomedical experience and the richest flora (34% endemic) of Europe and the Middle East, Turkey has a high potential for research on this topic. Plants that locals have been using for centuries for the prevention and treatment of influenza can offer effective alternatives to combat this problem. In this context, 224 herbal taxa belonging to 45 families were identified among the selected 81 studies conducted in the seven regions of Turkey. However, only 35 (15.6%) of them were found to be subjected to worldwide in vitro and in vivo research conducted on anti-influenza activity. Quercetin and chlorogenic acid, the effectiveness of which has been proven many times in this context, have been recorded as the most common (7.1%) active ingredients among the other 56 active substances identified.

AIM OF THE STUDY

This study has been carried out to reveal the inventory of plant species that have been used in flu treatment for centuries in Turkish folk medicine, which could be used in the treatment of flu or flu-like pandemics, such as COVID 19, that humanity has been suffering with, and also compare them with experimental studies in the literature.

MATERIALS AND METHODS

The investigation was conducted in two stages on the subject above by using electronic databases, such as Web of Science, Scopus, ScienceDirect, ProQuest, Medline, Cochrane Library, EBSCO, HighWire Press, PubMed and Google Scholar. The results of both scans are presented in separate tables, together with their regional comparative analysis.

RESULTS

Data obtained on taxa are presented in a table, including anti-influenza mechanism of actions and the active substances. Rosa canina (58.7%) and Mentha x piperita (22.2%) were identified as the most common plants used in Turkey. Also, Sambucus nigra (11.6%), Olea europaea (9.3%), Eucalyptus spp., Melissa officinalis, and Origanum vulgare (7.0%) emerged as the most investigated taxa.

CONCLUSION

This is the first nationwide ethnomedical screening work conducted on flu treatment with plants in Turkey. Thirty-nine plants have been confirmed in the recent experimental anti-influenza research, which strongly shows that these plants are a rich pharmacological source. Also, with 189 (84.4%) taxa, detections that have not been investigated yet, they are an essential resource for both national and international pharmacological researchers in terms of new natural medicine searches. Considering that the production of antimalarial drugs and their successful use against COVID-19 has begun, this correlation was actually a positive and remarkable piece of data, since there are 15 plants, including Centaurea drabifolia subsp. Phlocosa (an endemic taxon), that were found to be used in the treatment of both flu and malaria.

Lipolytic and Lipophagic Effects of Pinellia ternata Pharmacopuncture on Localized Adiposity

Localized adiposity is not only a common aesthetic issue but also a health risk factor. Pharmacopuncture can be a therapeutic option for the imbalance of regional fat distribution. The tuber of Pinellia ternata has been prescribed as antitussive and expectorant as a traditional Korean medicine. This study investigated the effects of pharmacopuncture with P. ternata water extract (PT) on localized adiposity. Male C57BL/6J mice were fed on a high-fat diet (HFD) for 6 weeks. 100 μL of 10 mg/mL of PT was injected into the left-side inguinal fat pad, while saline was injected into the right-side inguinal fat pad as self-control. Treatments were performed 3 times per week for 4 weeks. The inguinal fat weight was analyzed by dual-energy X-ray absorptiometry. PT pharmacopuncture significantly decreased the weight of the inguinal fat pad. The adipocyte size was reduced with increases of lipolytic enzymes and lipophagy-related factors by PT pharmacopuncture. There was marked inhibition of lipid accumulation content in 3T3-L1 adipocytes by PT treatment. The expressions of adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), autophagy-related gene (ATG) 5, ATG7, and LC3 were markedly increased by PT treatments in vivo and in vitro. This study suggests that pharmacopuncture of Pinellia ternata has ameliorative effects on adiposity by lipid catabolic effects via activating both lipolysis and lipophagy in a localized region.

Cardenolides and pentacyclic triterpenes isolated from Acokanthera oblongifolia leaves: their biological activities with molecular docking study

Pentacyclic triterpenes and cardenolides were isolated from Acokanthera oblongifolia leaves. Their chemical structures were determined based on comprehensive 1D and 2D NMR spectroscopy. Their MIC was determined against 12 microorganisms. Their exerted cytotoxicity on the immortalized normal cells, hTERT-RPE1 was assessed by the sulforhodamine-B assay. The viral inhibitory effects of compounds against Newcastle disease virus (NDV) and H5N1 influenza virus IV were evaluated. Four in vitro antioxidant assays were performed in comparison with BHT and trolox and a weak activity was exhibited. Acovenoside A was with potent against H5N1-IV and NDV with IC₅₀ ≤ 3.2 and ≤ 2.1 μg/ml and SI values of 93.75 and 95.23%, respectively, in comparison to ribavirin. Its CC₅₀ record on Vero cells was > 400 and 200 μg/ml, respectively. Acobioside A was the most active compound against a broad range of microbes while Pseudomonas aeruginosa was the most sensitive. Its MIC (0.07 μg/ml) was 1/100-fold of the recorded CC₅₀ (7.1 μg/ml/72 h) against hTERT-RPE1. The molecular docking of compounds on human DNA topoisomerase I (Top1-DNA) and IV glycoprotein hemagglutinin were studied using MOE program. This study has introduced the cardenolides rather than triterpenoids with the best docking score and binding interaction with the active site of the studied proteins.

The Inhibitory Activities and Antiviral Mechanism of Medicinal Plant Ingredient Quercetin Against Grouper Iridovirus Infection

Singapore grouper iridovirus (SGIV) causes high mortality rates in mariculture, and effective treatments against SGIV infection are urgently required. Illicium verum Hook. f. (I. verum) is a well-known medicinal plant with a variety of biological activities. The natural ingredient quercetin isolated from I. verum could effectively inhibit SGIV infection in a dose-dependent manner. The possible antiviral mechanism of quercetin was further analyzed in this study. It showed that quercetin did obvious damages to SGIV particles. Furthermore, quercetin could interfere with SGIV binding to targets on host cells (by 76.14%), disturb SGIV invading into host cells (by 56.03%), and effect SGIV replication in host cells (by 52.73%), respectively. Quercetin had the best antiviral effects during the SGIV life cycle of binding to the receptors on host cells' membranes. Overall, the results suggest that quercetin has direct and host-mediated antiviral effects against SGIV and holds great potential for developing effective drugs to control SGIV infection in aquaculture.

Bioactive Natural Antivirals: An Updated Review of the Available Plants and Isolated Molecules

Viral infections and associated diseases are responsible for a substantial number of mortality and public health problems around the world. Each year, infectious diseases kill 3.5 million people worldwide. The current pandemic caused by COVID-19 has become the greatest health hazard to people in their lifetime. There are many antiviral drugs and vaccines available against viruses, but they have many disadvantages, too. There are numerous side effects for conventional drugs, and active mutation also creates drug resistance against various viruses. This has led scientists to search herbs as a source for the discovery of more efficient new antivirals. According to the World Health Organization (WHO), 65% of the world population is in the practice of using plants and herbs as part of treatment modality. Additionally, plants have an advantage in drug discovery based on their long-term use by humans, and a reduced toxicity and abundance of bioactive compounds can be expected as a result. In this review, we have highlighted the important viruses, their drug targets, and their replication cycle. We provide in-depth and insightful information about the most favorable plant extracts and their derived phytochemicals against viral targets. Our major conclusion is that plant extracts and their isolated pure compounds are essential sources for the current viral infections and useful for future challenges.

Sociocultural, behavioural and political factors shaping the COVID-19 pandemic: the need for a biocultural approach to understanding pandemics and (re)emerging pathogens

Although there has been increasing focus in recent years on interdisciplinary approaches to health and disease, and in particular the dimension of social inequalities in epidemics, infectious diseases have been much less focused on. This is especially true in the area of cultural dynamics and their effects on pathogen behaviours, although there is evidence to suggest that this relationship is central to shaping our interactions with infectious disease agents on a variety of levels. This paper makes a case for a biocultural approach to pandemics such as COVID-19. It then uses this biocultural framework to examine the anthropogenic dynamics that influenced and continue to shape the COVID-19 pandemic, both during its initial phase and during critical intersections of the pandemic. Through this understanding of biocultural interactions between people, animals and pathogens, a broader societal and political dimension is drawn as a function of population level and international cultures, to reflect on the culturally mediated differential burden of the pandemic. Ultimately, it is argued that a biocultural perspective on infectious disease pandemics will allow for critical reflection on how culture shapes our behaviours at all levels, and how the effects of these behaviours are ultimately foundational to pathogen ecology and evolution.

Rapid identification and isolation of neuraminidase inhibitors from mockstrawberry (Duchesnea indica Andr.) based on ligand fishing combined with HR-ESI-Q-TOF-MS

Neuraminidase inhibitors (NAIs) are the mainstay antiviral drugs against influenza infection. In this study, a ligand fishing protocol was developed to screen NAIs using neuraminidase immobilized magnetic beads (NA-MB). After verifying the feasibility of NA-MB with an artificial mixture including NA inhibitors and non-inhibitors, the developed ligand fishing protocol was applied to screen NAIs from the crude extracts of Duchesnea indica Andr. Twenty-four NA binding compounds were identified from the normal butanol (n-BuOH) extract of D. indica as potential NAIs by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC–Q-TOF-MS) assisted with Compound Structure Identification (CSI):FingerID, including 12 ellagitannins, 4 brevifolin derivatives, 3 ellagic acid derivatives, and 4 flavonoids. Among them, 9 compounds were isolated and tested for in vitro NA inhibitory activities against NA from Clostridium perfringens, and from oseltamivir sensitive and resistant influenza A virus strains. The results indicate that compound B23 has the NA inhibitory activities in both the oseltamivir sensitive and resistant viral NA, with half maximal inhibitory concentration (IC₅₀) values of 197.9 and 125.4 μmol/L, respectively. Moreover, B23 can obviously reduce the replication of oseltamivir sensitive and resistant viruses in Madin–Darby canine kidney (MDCK) cells at the concentrations of 40 and 200 μmol/L.

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An efficient ligand fishing protocol was developed to rapidly screen the neuraminidase inhibitors from natural sources.

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24 potential neuraminidase inhibitors were identified from Duchesnea indica as potential NAIs by HPLC-Q-TOF-MS.

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One compound can inhibit neuraminidase activities in both the oseltamivir sensitive and resistant virus strains.

Antiviral activity of Illicium verum Hook. f. extracts against grouper iridovirus infection

Grouper iridovirus causes high mortality rates in cultured groupers, and effective treatment for grouper iridovirus infection is urgently required. Illicium verum Hook. f. is a well-known medicinal plant with a variety of biological activities. The aim of this study was to analyse the use of I. verum extracts to treat grouper iridovirus infection. The safe working concentration of each I. verum extract was identified both in vitro and in vivo as follows: I. verum aqueous extract (IVAE) ≤ 500 μg/ml; I. verum ethanol extract (IVEE) ≤ 250 μg/ml; shikimic acid (SKA) ≤ 250 μg/ml; trans-anethole (TAT) ≤ 800 μg/ml; 3,4-dihydroxybenzoic acid (DDBA) ≤ 400 μg/ml; and quercetin (QCE) ≤ 50 μg/ml. The inhibitory activity of each I. verum extract against grouper iridovirus infection was analysed using aptamer (Q2)-based fluorescent molecular probe (Q2-AFMP) and RT-qPCR. All of the I. verum extracts displayed dose-dependent antiviral activities against grouper iridovirus. Based on the achieved per cent inhibition, IVAE, IVEE, DDBA and QCE were associated with the greatest antiviral activity (all > 90%). Together, our results indicate that I. verum extracts have effective antiviral properties, making it an excellent potential source material for the development of effective treatment for grouper iridovirus infection.

Herbal extracts as antiviral agents

Phytotherapy, or herbalism, is defined as the usage of plants or herbs as medication to treat or prevent diseases in human and animals. The usage is gaining more attention among medical practitioners as well as large-scale livestock producers. A number of reports have shown the positive effects of herbal extracts as an antiviral agent used in animal feed or as a prophylaxis and remedy. Besides being a cheaper and safer alternative, the use of herbs may reduce the incidence of drug resistance and may modulate the immune system in preventing viral-related diseases. In this chapter, the antiviral effects of several herbs and their extracts against viruses in terms of the mechanism of action in targeting viral replication steps, the effects in the host and the application in animals will be discussed. The information given may aid in improving the health and increase the production of animals.

Pterodontic acid isolated from Laggera pterodonta suppressed RIG-I/NF-KB/STAT1/Type I interferon and programmed death-ligand 1/2 activation induced by influenza A virus in vitro

Influenza viruses can bring about acute respiratory diseases and are a potential hazard to human health. Antiviral drugs are the main ways to control the influenza virus infection except the vaccine. In this study, the immune regulation activity of pterodontic acid isolated from Laggera pterodonta induced by influenza A virus in vitro was evaluated. In studies on anti-influenza activity, our results showed that it maybe target the influenza protein of polymerase basic 1 (PB1), polymerase basic 2 (PB2), polymerase acid (PA), nuclear protein (NP), non-structural protein (NS), and matrix protein (M) but not hemagglutinin (HA) and neuraminidase (NA). In studies on immune regulation, our results demonstrated that pterodontic acid can inhibit the Retinoic acid inducible gene-I (RIG-I) expression in mRNA and protein level at 100 μg/ml, then further to clarify its action on the signalling pathway, The results indicated that pterodontic acid can inhibit the Tumor Necrosis Factor-related Apoptosis-inducing Ligand/Fas Ligand (TRAIL/Fasl) expression in mRNA level at 100 μg/ml; the cleaved caspase 3/7, p-NF-KB, and p-ERK were all suppressed in protein level by pterodontic acid at 100 μg/ml. This confirmed its mechanism that restrained the nuclear export of viral RNPs. The interferon system was also affected, the STAT1, IFN-α, IFN-β expression were also inhibited by pterodontic acid at 25-100 μg/ml and also, the important programmed death-ligand of PD-L1 and PD-L2 was inhibited at 50-100 μg/ml. The mechanisms of pterodontic acid against influenza virus infection may be a cascade inhibition and it has the anti-inflammatory activity, which has no side effect, and can be as a supplement drug in clinical influenza virus infection.

The Signaling Pathways, and Therapeutic Targets of Antiviral Agents: Focusing on the Antiviral Approaches and Clinical Perspectives of Anthocyanins in the Management of Viral Diseases

As the leading cause of death worldwide, viruses significantly affect global health. Despite the rapid progress in human healthcare, there are few viricidal and antiviral therapies that are efficient enough. The rapid emergence of resistance, and high costs, as well as the related side effects of synthetic antiviral drugs, raise the need to identify novel, effective, and safe alternatives against viral diseases. Nature has been of the most exceptional help and source of inspiration for developing novel multi-target antiviral compounds, affecting several steps of the viral life cycle and host proteins. For that matter and due to safety and efficacy limitations, as well as high resistance rate of conventional therapies, hundreds of natural molecules are preferred over the synthetic drugs. Besides, natural antiviral agents have shown acceptable antiviral value in both preclinical and clinical trials.This is the first review regarding molecular and cellular pathways of the virus life cycle, treatment strategies, and therapeutic targets of several viral diseases with a particular focus on anthocyanins as promising natural compounds for significant antiviral enhancements. Clinical applications and the need to develop nano-formulation of anthocyanins in drug delivery systems are also considered.

Unraveling the Molecular Mechanism of Traditional Chinese Medicine: Formulas Against Acute Airway Viral Infections as Examples

Herbal medicine, including traditional Chinese medicine (TCM), is widely used worldwide. Herbs and TCM formulas contain numerous active molecules. Basically, they are a kind of cocktail therapy. Herb-drug, herb-food, herb-herb, herb-microbiome, and herb-disease interactions are complex. There is potential for both benefit and harm, so only after understanding more of their mechanisms and clinical effects can herbal medicine and TCM be helpful to users. Many pharmacologic studies have been performed to unravel the molecular mechanisms; however, basic and clinical studies of good validity are still not enough to translate experimental results into clinical understanding and to provide tough evidence for better use of herbal medicines. There are still issues regarding the conflicting pharmacologic effects, pharmacokinetics, drug interactions, adverse and clinical effects of herbal medicine and TCM. Understanding study validation, pharmacologic effects, drug interactions, indications and clinical effects, adverse effects and limitations, can all help clinicians in providing adequate suggestions to patients. At present, it would be better to use herbs and TCM formulas according to their traditional indications matching the disease pathophysiology and their molecular mechanisms. To unravel the molecular mechanisms and understand the benefits and harms of herbal medicine and TCM, there is still much work to be done.

Antiviral activity of Portulaca oleracea L. against influenza A viruses

ETHNOPHARMACOLOGICAL RELEVANCE

Portulaca oleracea L. is used not only as an edible potherb but also as a traditional remedy to assuage the symptoms of various diseases. The water extract of P. oleracea (WEPO) has been found to effectively alleviate the signs and symptoms of pandemic influenza A virus (IAV) infection. However, the anti-IAV activity of WEPO is still unclear.

AIM OF STUDY

In this study, we aimed to elucidate the anti-IAV activity of WEPO and investigate the potential mechanisms underlying the anti-H1N1 activity.

MATERIALS AND METHODS

The cytotoxicity of WEPO and other Chinese herbs was measured using the cell viability test. The anti-IAV activity of WEPO was determined using the plaque reduction assay, real-time reverse transcription-polymerase chain reaction, and immunofluorescence assay. The virucidal activity of WEPO was determined by labeling the virus and using the time-dependent virucidal activity assay.

RESULTS

The half-maximal effective concentration of WEPO for A/WSN/1933 (H1N1) was very low, with a high selectivity index. The production of circulating H1N1 and H3N2 was suppressed by WEPO. Additionally, the antiviral activity of WEPO was observed in the early stage of IAV infection. Furthermore, WEPO inhibited the binding of virus to cells and exhibited good virucidal activity, significantly decreasing the viral load within 10 min to prevent viral infection.

CONCLUSIONS

We demonstrate the anti-IAV activity of WEPO and strongly recommend the use of WEPO, as an herbal regimen, to prevent and treat H1N1 infection at an early stage.

Greater Efficacy of Black Ginseng (CJ EnerG) over Red Ginseng against Lethal Influenza A Virus Infection

Black ginseng (BG, CJ EnerG), prepared via nine repeated cycles of steaming and drying of fresh ginseng, contains more accessible acid polysaccharides and smaller and less polar ginsenosides than red ginseng (RG) processed only once. Because RG exhibits the ability to increase host protection against viral respiratory infections, we investigated the antiviral effects of BG. Mice were orally administered either BG or RG extract at 10 mg/kg bw daily for two weeks. Mice were then infected with a A(H1N1) pdm09 (A/California/04/2009) virus and fed extracts for an additional week. Untreated, infected mice were assigned to either the negative control, without treatments, or the positive control, treated with Tamiflu. Infected mice were monitored for 14 days to determine the survival rate. Lung tissues were evaluated for virus titer and by histological analyses. Cytokine levels were measured in bronchoalveolar lavage fluid. Mice treated with BG displayed a 100% survival rate against infection, while mice treated with RG had a 50% survival rate. Further, mice treated with BG had fewer accumulated inflammatory cells in bronchioles following viral infection than did mice treated with RG. BG also enhanced the levels of GM-CSF and IL-10 during the early and late stages of infection, respectively, compared to RG. Thus, BG may be useful as an alternative antiviral adjuvant to modulate immune responses to influenza A virus.

Different types of effective fractions from Radix Isatidis revealed a multiple-target synergy effect against respiratory syncytial virus through RIG-I and MDA5 signaling pathways, a pilot study to testify the theory of superposition of traditional Chinese Medicine efficacy

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Isatidis, a commonly used traditional Chinese medicine, is also documented in "Dictionary of Chinese Ethnic Medicine" being as an ethnic herb clinically utilized by different nations in China such as Mongol, Uygur, and Dong et al. It has been reported to have a very strong efficacy on respiratory viruses, but to date the mechanism remains unknown. Similarly, it is unclear how different types of effective fractions of Radix Isatidis interact to exert antiviral effects.

AIM OF STUDY

To reveal the underlying mechanisms for the inhibitory effects of three active fractions from Radix Isatidis, i.e. total alkaloids, lignans and organic acids, on respiratory syncytial virus when used alone or in combination. In addition, we investigated whether these three parts worked synergistically in vivo and in vitro.

MATERIALS AND METHODS

A mouse model of RSV infection was constructed by intranasal infection, and the pathological changes of lung tissues in different parts were observed. The level changes of IFNβ and inflammatory cytokines in the mouse alveolar lavage fluid were detected by enzyme-linked immunosorbent assay (ELISA). The anti-RSV effects of different effective fractions were evaluated by the plaque reduction test. The mRNA and protein expressions of RIG-I, MDA-5, MAVS and IRF3 in RAW264.7 cells were detected by RT-PCR and Western blot respectively.

RESULTS

HE staining showed that Radix Isatidis extracts alone or in combination relieved virus-induced mouse lung lesions. Compared with individual drugs, the lung lesions were alleviated more significantly after treatment with the three fractions in combination. ELISA demonstrated that the expression levels of IFNβ and inflammatory cytokines were maintained balanced between antiviral and proinflammatory effects. The plaque reduction test indicated that the antiviral effect of combination treatment was much stronger than those of individual drugs. RT-qPCR and Western blot suggested that the mRNA and protein expression levels of key signaling molecules in the RIG-I and MDA5 pathways in mouse macrophages were down-regulated by different effective parts alone or in combination.

CONCLUSIONS

The three effective fractions of Radix Isatidis have remarkable synergistic anti-RSV effects in vitro and in vivo, and total alkaloids and lignans show multi-target synergistic effects via the RIG-I and MDA5 signaling pathways.

Asprellcosides B of Ilex asprella Inhibits Influenza A Virus Infection by Blocking the Hemagglutinin- Mediated Membrane Fusion

Ilex asprella is routinely used in China as a traditional medicinal herb to treat influenza (Flu). However, its specific antiviral activity and underlying molecular mechanism have not yet been determined. In this study, we sought to determine the antiviral activity and mechanism of Asprellcosides B, an active component extracted from Ilex asprella, and used against the influenza A virus cell culture. We also performed a computer-assisted structural modeling analysis and carried out surface plasmon resonance (SPR) experiments in the hope of determining the viral target of Asprellcosides B. Results from our studies show that Asprellcosides B reduced virus replication by up to 63% with an IC50 of about 9 μM. It also decreased the low pH-induced and virus-mediated hemolysis by 71% in vitro. Molecular docking simulation analysis suggested a possible binding of Asprellcosides B to the hemagglutinin (HA), which was confirmed by a surface plasmon resonance (SPR) assay. Altogether, our findings demonstrate that Asprellcosides B inhibits the influenza A virus, through a specific binding to the HA, resulting in the blockade of the HA-mediated membrane fusion.

Antiviral Activities of Oleanolic Acid and Its Analogues

Viral diseases, such as human immune deficiency virus (HIV), influenza, hepatitis, and herpes, are the leading causes of human death in the world. The shortage of effective vaccines or therapeutics for the prevention and treatment of the numerous viral infections, and the great increase in the number of new drug-resistant viruses, indicate that there is a great need for the development of novel and potent antiviral drugs. Natural products are one of the most valuable sources for drug discovery. Most natural triterpenoids, such as oleanolic acid (OA), possess notable antiviral activity. Therefore, it is important to validate how plant isolates, such as OA and its analogues, can improve and produce potent drugs for the treatment of viral disease. This article reports a review of the analogues of oleanolic acid and their selected pathogenic antiviral activities, which include HIV, the influenza virus, hepatitis B and C viruses, and herpes viruses.

Berberine-piperazine conjugates as potent influenza neuraminidase blocker

In these studies, we analyzed substituted piperazine based berberine analogs conjugated through a pentyloxy side chain for their in vitro and in silico biological effects. All the final analogs were screened for their in vitro antiviral action against a collection of different influenza virus strains using the CPE assay and SRB assay. Moreover, their cytotoxicity towards non-cancer cell lines was examined employing Madin-Darby canine kidney (MDCK) cell lines. The anti-influenza activities of berberine-piperazine derivatives (BPD) were evaluated in the range from 35.16 μg/mL to 90.25 μg/mL of the IC₅₀s along with cytotoxicity level which was observed in the range 44.8 μg/mL to 3890.6 μg/mL of CC₅₀s towards MDCK cells. In an effort to know the mechanism of action of BPD1-BPD23, results of Neuraminidase inhibition assay and Molecular docking studies carried out against neuraminidase as the target enzyme revealed that titled compounds are potential neuraminidase inhibitors that merge to the active site of neuraminidase, with moderate to high binding energy.

The Cranberry Extract Oximacro® Exerts in vitro Virucidal Activity Against Influenza Virus by Interfering With Hemagglutinin

The defense against influenza virus (IV) infections still poses a series of challenges. The current antiviral arsenal against influenza viruses is in fact limited; therefore, the development of new anti-influenza strategies effective against antigenically different viruses is an urgent priority. Bioactive compounds derived from medicinal plants and fruits may provide a natural source of candidates for such broad-spectrum antivirals. In this regard, cranberry (Vaccinium macrocarpon Aiton) extracts on the basis of their recognized anti-adhesive activities against bacteria, may provide potential compounds able to prevent viral attachment to target cells. Nevertheless, only few studies have so far investigated the possible use of cranberry extracts as an antiviral tool. This study focuses on the suitability of a cranberry extract as a direct-acting anti-influenza compound. We show that the novel cranberry extract Oximacro® inhibits influenza A and B viruses (IAV, IBV) replication in vitro because of its high content of A-type proanthocyanidins (PAC-A) dimers and trimers. Mechanistic studies revealed that Oximacro® prevents attachment and entry of IAV and IBV into target cells and exerts a virucidal activity. Oximacro® was observed to interact with the ectodomain of viral hemagglutinin (HA) glycoprotein, thus suggesting the interference with HA functions and a consequent loss of infectivity of IV particles. Fluorescence spectroscopy revealed a reduction in the intrinsic fluorescence of HA protein after incubation with purified dimeric PAC-A (PAC-A2), thus confirming a direct interaction between HA and Oximacro® PAC-A2. In silico docking simulations further supported the in vitro results and indicated that among the different components of the Oximacro® chemical profile, PAC-A2 exhibited the best binding propensity with an affinity below 10 nM. The role of PAC-A2 in the anti-IV activity of Oximacro® was eventually confirmed by the observation that it prevented IAV and IVB replication and caused the loss of infectivity of IV particles, thus indicating PAC-A2 as the major active component of Oximacro®. As a whole, these results suggest Oximacro® as a potential candidate to create novel antiviral agents of natural origin for the prevention of IV infections.

Magnetic beads-based neuraminidase enzyme microreactor as a drug discovery tool for screening inhibitors from compound libraries and fishing ligands from natural products

Neuraminidase (NA) is a glycoside hydrolase that has been proposed as a potential therapeutic target for influenza. Thus, the identification of compounds that modulate NA activity could be of great therapeutic importance. The aim of this study is to develop a drug discovery tool for the identification of novel modulators of NA from both compound libraries and natural plant extracts. NA was immobilized onto the surface of magnetic beads and the inherent catalytic activity of NA-functionalized magnetic beads was characterized. Based on the enzymatic activity (hydrolysis ratio), the inhibitory activities of 12 compounds from plant secondary metabolites were screened, and the desired anti-NA activities of flavonoids were certified. Ligand fishing with the immobilized enzyme was optimized using an artificial test mixture consisting of oseltamivir, lycorine and matrine prior to carrying out the proof-of-concept experiment with the crude extract of Flos Lonicerae. The combination of ligand fishing and HPLC-MS/MS identified luteolin-7-O-β-D-glucoside, luteolin, 3,5-di-O-caffeoylquinic acid and 3,4-di-O-caffeoylquinic acid as neuraminidase inhibitory ligands in Flos Lonicerae. This is the first report on the use of neuraminidase functionalized magnetic beads for the identification of active ligands from a botanical matrix, and it sets the basis for the de novo identification of NA modulators from complex biological mixtures.

Comparison of the Trace Elements and Active Components of Lonicera japonica flos and Lonicera flos Using ICP-MS and HPLC-PDA

Thirteen trace elements and active constituents of 40 batches of Lonicera japonica flos and Lonicera flos were comparatively studied using inductively coupled plasma mass-spectrometry (ICP-MS) and high-performance liquid chromatography-photodiode array (HPLC-PDA). The trace elements were ²⁴Mg, ⁵²Cr, ⁵⁵Mn, ⁵⁷Fe, ⁶⁰Ni, ⁶³Cu, ⁶⁶Zn, ⁷⁵As, ⁸²Se, ⁹⁸Mo, ¹¹⁴Cd, ²⁰²Hg, and ²⁰⁸Pb, and the active compounds were chlorogenic acid, 3,5-O-dicaffeoylquinc acid, 4,5-O-dicaffeoylquinc acid, luteolin-7-O-glucoside, and 4-O-caffeoylquinic acid. The data of 18 variables were statistically processed using principal component analysis (PCA) and discriminate analysis (DA) to classify L. japonica flos and L. flos. The validated method was developed to divide the 40 samples into two groups based on the PCA in terms of 18 variables. Furthermore, the species of Lonicera was better discriminated by using DA with 12 variables. These results suggest that the method and statistical analysis of the contents of trace elements and chemical components can classify the L. japonica flos and L. flos using 12 variables, such as 3,5-O-dicaffeoylquincacid, luteolin-7-O-glucoside, Cd, Mn, Hg, Pb, Ni, 4-O-caffeoyl-quinic acid, 4,5-O-dicaffeoylquinc acid, Fe, Mg, and Cr.

Inhibition of Influenza Virus Infection by Lentinus edodes Mycelia Extract Through Its Direct Action and Immunopotentiating Activity

Lentinula edodes mycelia (LEM) solid culture extracts contain many bioactive compounds with diverse pharmacological activities such as antitumor, antiviral, and immunopotentiating effects. In this study, we examined the anti-influenza virus activity of LEM in vitro and in vivo. LEM directly inhibited influenza virus growth in vitro at early phases of infection, possibly at the entry process of viral particles to host cells. We also found that the nasal administration of LEM increased the survival rate of infected mice, and this was likely due to the direct action of LEM on the viral growth. The oral administration of LEM showed prolonged median survival time of infected mice. Histological analysis revealed that the moderate bronchiolitis was observed in infected mice by the oral administration with LEM, and the extent of alveolitis was dramatically reduced. The orally LEM-administered mice showed a rapid activation of IFN-β gene expression upon influenza virus infection. These results suggest that the immunopotentiation activity of LEM on type I IFN pathway represses the virus spread to distal alveolar regions from peribronchiolar regions which are primary infection sites in the mouse model. We propose that LEM has anti-influenza virus activities through the direct action on viral growth and stimulatory activity of innate immunity.