Polygonum cuspidatum and its active components inhibit replication of the influenza virus through toll-like receptor 9-induced interferon beta expression

Resveratrol targeting NRF2 disrupts the binding between KEAP1 and NRF2-DLG motif to ameliorate oxidative stress damage in mice pulmonary infection

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Polygonum cuspidatum Sieb. et Zucc (PC), known as 'Huzhang' in the Chinese Pharmacopoeia, has been traditionally employed for its anti-inflammatory, antiviral, antimicrobial, and other biological activities. Polydatin (PD) and its aglycone, resveratrol (RES), are key pharmacologically active components responsible for exerting anti-inflammatory and antioxidant effects. However, its specific targets and action mechanisms remain unclear.

AIM OF THE STUDY

The equilibrium of the KEAP1-NRF2 system serves as the primary protective response to oxidative and electrophilic stresses within the body, particularly in cases of acute lung injury caused by pathogenic microbial infection. In this study, the precise mechanisms by which RES alleviates oxidative stress damage in conjunction with NRF2 activators are discussed.

MATERIALS AND METHODS

The active components from PC were screened to evaluate their potential to inhibit reactive oxygen species (ROS) and activate antioxidant activity dependent on antioxidant response elements (ARE). RES was evaluated for its potential to alleviate the oxidative stress caused by pathogenic microbial infection. Functional probes were designed to study the RES distribution and identify its targets. A lipopolysaccharide (LPS)-induced oxidative injury model was used to evaluate the effects of RES on the KEAP1-NRF2/ARE pathway in RAW 264.7 cells. The interaction between RES and NRF2 was elucidated using drug-affinity responsive target stability (DARTS), cellular thermal shift assays (CETSA), co-immunoprecipitation (Co-IP), and microscale thermophoresis (MST) techniques. The key binding sites were predicted using molecular docking and validated in NRF2-knockdownand reconstructed cells. Finally, protective effects against pulmonary stress were verified in a mouse model of pathogenic infection.

RESULTS

The accumulation of RES in lung macrophages disrupted the binding between KEAP1 and NRF2, thereby preventing the ubiquitination degradation of NRF2 through its interaction with Ile28 on the NRF2-DLG motif. The activation of NRF2 resulted in the upregulation of nuclear transcription, enhances the expression of antioxidant genes dependent on ARE, suppresses ROS generation, and ameliorates oxidative damage both in vivo and in vitro.

CONCLUSION

These findings shed light on the potential of RES to mitigate oxidative stress damage caused by pathogenic microorganism-induced lung infections and facilitate the discovery of novel small molecule modulators targeting the KEAP1-NRF2 DLG motif interaction.

Advances for pharmacological activities of Polygonum cuspidatum - A review

CONTEXT

Polygonum cuspidatum Sieb. et Zucc (Polygonaceae), the root of which is included in the Chinese Pharmcopoeia under the name 'Huzhang', has a long history as a medicinal plant and vegetable. Polygonum cuspidatum has been used in traditional Chinese medicine for the treatment of inflammation, hyperlipemia, etc.

OBJECTIVE

This article reviews the pharmacological action and the clinical applications of Polygonum cuspidatum and its extracts, whether in vivo or in vitro. We also summarized the main phytochemical constituents and pharmacokinetics of Polygonum cuspidatum and its extracts.

METHODS

The data were retrieved from major medical databases, such as CNKI, PubMed, and SinoMed, from 2014 to 2022. Polygonum cuspidatum, pharmacology, toxicity, clinical application, and pharmacokinetics were used as keywords.

RESULTS

The rhizomes, leaves, and flowers of Polygonum cuspidatum have different phytochemical constituents. The plant contains flavonoids, anthraquinones, and stilbenes. Polygonum cuspidatum and the extracts have anti-inflammatory, antioxidation, anticancer, heart protection, and other pharmacological effects. It is used in the clinics to treat dizziness, headaches, traumatic injuries, and water and fire burns.

CONCLUSIONS

Polygonum cuspidatum has the potential to treat many diseases, such as arthritis, ulcerative colitis, asthma, and cardiac hypertrophy. It has a broad range of medicinal applications, but mainly focused on root medication; its aerial parts should receive more attention. Pharmacokinetics also need to be further investigated.

Assessment of the potential value of combining western medicine therapies with traditional chinese medicine in the treatment of COVID-19: Mechanistic perspectives

BACKGROUND

The pandemic caused by the novel coronavirus disease (COVID-19) since early 2020 is one of the most significant global health issues in history. Although there is currently no specific treatment for COVID-19, researchers have provided a whole array of potential treatments, both from the Western medicine approach, which is molecular target and pathogenesis based, and from the traditional Chinese medicine (TCM) approach, which is based on the exposure to toxins/pathogens and the balance of the body to combat them for recovery.

OBJECTIVE

The aim of this research is to find combinations of Western medicine and TCM that may offer better therapeutic efficacy synergystically with a better adverse events profile. The findings of the research may provide a new insight in the development of the treatment of COVID-19.

METHODS

From the Western medicine perspective, drugs target the mechanisms of viral infection, including the stages of viral entry (Arbidol, Camostat Mesylate, Convalescent Plasma therapy) and viral replication (Lopinavir/Ritonavir, Redemsivir, Ribavirin). Additional therapies target host defenses, preventing cytokine storms (Tocilizumab) and stimulating the immune system (Interferons). On the other hand, TCM also proposed a number of treatment methods for COVID-19 with new scientific approaches identifying their antiviral and immunomodulatory activities. The novel combination of Western medicine and TCM can be proposed by analyzing their respective molecular targets.

RESULTS

Although TCM is not generally accepted in the Western community because of the general lack of knowledge on their detailed mechanisms, studies and clinical trials suggest that TCM could be beneficial in combating COVID-19.

CONCLUSION

Based on the principle of combining TCM and Western medicine, two combinations are tested effective in clinical trials, and three possible combinations that might be effective are proposed in the paper.

Modulation of type I interferon signaling by natural products in the treatment of immune-related diseases

Type I interferon (IFN) is considered as a bridge between innate and adaptive immunity. Proper activation or inhibition of type I IFN signaling is essential for host defense against pathogen invasion, tumor cell proliferation, and overactive immune responses. Due to intricate and diverse chemical structures, natural products and their derivatives have become an invaluable source inspiring innovative drug discovery. In addition, some natural products have been applied in clinical practice for infection, cancer, and autoimmunity over thousands of years and their promising curative effects and safety have been well-accepted. However, whether these natural products are primarily targeting type I IFN signaling and specific molecular targets involved are not fully elucidated. In the current review, we thoroughly summarize recent advances in the pharmacology researches of natural products for their type I IFN activity, including both agonism/activation and antagonism/inhibition, and their potential application as therapies. Furthermore, the source and chemical nature of natural products with type I IFN activity are highlighted and their specific molecular targets in the type I IFN pathway and mode of action are classified. In conclusion, natural products possessing type I IFN activity represent promising therapeutic strategies and have a bright prospect in the treatment of infection, cancer, and autoimmune diseases.

Antiviral and Anti-Inflammatory Plant-Derived Bioactive Compounds and Their Potential Use in the Treatment of COVID-19-Related Pathologies

The highly contagious coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been declared a global pandemic and public health emergency as it has taken the lives of over 5.7 million in more than 180 different countries. This disease is characterized by respiratory tract symptoms, such as dry cough and shortness of breath, as well as other symptoms, including fever, chills, and fatigue. COVID-19 is also characterized by the excessive release of cytokines causing inflammatory injury to the lungs and other organs. It is advised to undergo precautionary measures, such as vaccination, social distancing, use of masks, hygiene, and a healthy diet. This review is aimed at summarizing the pathophysiology of COVID-19 and potential biologically active compounds (bioactive) found in plants and plant food. We conclude that many plant food bioactive compounds exhibit antiviral and anti-inflammatory properties and support in attenuating organ damage due to reduced cytokine release and improving the recovery process from COVID-19 infection.

A comprehensive review of traditional uses, phytochemistry and pharmacology of Reynoutria genus

Objectives

The genus Reynoutria belonging to the family Polygonaceae is widely distributed in the north temperate zone and used in folk medicine. It is administered as a sedative, tonic and digestive, also as a treatment for canities and alopecia. Herein, we reported a review on traditional uses, phytochemistry and pharmacology reported from 1985 up to early 2022. All the information and studies concerning Reynoutria plants were summarized from the library and digital databases (e.g. ScienceDirect, SciFinder, Medline PubMed, Google Scholar, and CNKI).

Key findings

A total of 185 articles on the genus Reynoutria have been collected. The phytochemical investigations of Reynoutria species revealed the presence of more than 277 chemical components, including stilbenoids, quinones, flavonoids, phenylpropanoids, phospholipids, lactones, phenolics and phenolic acids. Moreover, the compounds isolated from the genus Reynoutria possess a wide spectrum of pharmacology such as anti-atherosclerosis, anti-inflammatory, antioxidative, anticancer, neuroprotective, anti-virus and heart protection.

Summary

In this paper, the traditional uses, phytochemistry and pharmacology of genus Reynoutria were reviewed. As a source of traditional folk medicine, the Reynoutria genus have high medicinal value and they are widely used in medicine. Therefore, we hope our review can help genus Reynoutria get better development and utilization.

Japanese Knotweed Rhizome Bark Extract Inhibits Live SARS-CoV-2 In Vitro

Coronavirus disease 2019 (COVID-19), a viral infectious respiratory disease, is caused by highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is responsible for the ongoing COVID-19 pandemic. Since very few drugs are known to be effective against SARS-CoV-2, there is a general need for new therapeutics, including plant-based drugs, for the prophylaxis and treatment of infections. In the current study, the activity of a 70% ethanolic(aq) extract of the rhizome bark of Japanese knotweed, an invasive alien plant species, was tested for the first time against the wild-type SARS-CoV-2 virus using a specific and robust virus neutralization test (VNT) on Vero-E6 cells, which best mimics the mechanism of real virus−host interaction. A statistically significant antiviral effect against SARS-CoV-2 (p-value < 0.05) was observed for the 50.8 µg mL−1 extract solution in cell medium. A suitable extract preparation was described to avoid loss of polyphenols throughout filtration of the extract, which was dissolved in cell medium containing fetal bovine serum (FBS). The significance of the differences between the sums of the test and control groups in the incidence of cytopathic effects (CPE) was determined using the one-way ANOVA test. A dose−response relationship was observed, with the cytotoxic effect occurring at higher concentrations of the extract (≥101.6 µg mL−1). The obtained results suggest possible use of this plant material for the production of various products (e.g., packaging, hygiene products, biodisinfectants, etc.) that would be useful against the spread of and for self-protection against COVID-19.

Antiviral activity of natural phenolic compounds in complex at an allosteric site of SARS-CoV-2 papain-like protease

SARS-CoV-2 papain-like protease (PLpro) covers multiple functions. Beside the cysteine-protease activity, facilitating cleavage of the viral polypeptide chain, PLpro has the additional and vital function of removing ubiquitin and ISG15 (Interferon-stimulated gene 15) from host-cell proteins to support coronaviruses in evading the host's innate immune responses. We identified three phenolic compounds bound to PLpro, preventing essential molecular interactions to ISG15 by screening a natural compound library. The compounds identified by X-ray screening and complexed to PLpro demonstrate clear inhibition of PLpro in a deISGylation activity assay. Two compounds exhibit distinct antiviral activity in Vero cell line assays and one inhibited a cytopathic effect in non-cytotoxic concentration ranges. In the context of increasing PLpro mutations in the evolving new variants of SARS-CoV-2, the natural compounds we identified may also reinstate the antiviral immune response processes of the host that are down-regulated in COVID-19 infections.

The Invasive Species Reynoutria japonica Houtt. as a Promising Natural Agent for Cardiovascular and Digestive System Illness

Polygoni Cuspidati Rhizoma et Radix, the dry roots and stems of Reynoutria japonica Houtt (called Huzhang, HZ in Chinese), is a traditional and popular chinese medicinal herb for thousands of years. As a widely used ethnomedicine in Asia including China, Japan, and Korea, HZ can invigorate the blood, cool heat, and resolve toxicity, which is commonly used in the treatment of favus, jaundice, scald, and constipation. However, HZ is now considered an invasive plant in the United States and many European countries. Therefore, in order to take advantage of HZ and solve the problem of biological invasion, scholars around the world have carried out abundant research studies on HZ. Until now, about 110 compounds have been isolated and identified from HZ, in which anthraquinones, stilbenes, and flavonoids would be the main bioactive ingredients for its pharmacological properties, such as microcirculation improvement, myocardial protective effects, endocrine regulation, anti-atherosclerotic activity, anti-oxidant activity, anti-tumor activity, anti-viral activity, and treatment of skin inflammation, burns, and scalds. HZ has a variety of active ingredients and broad pharmacological activities. It is widely used in health products, cosmetics, and even animal husbandry feed and has no obvious toxicity. Efforts should be made to develop more products such as effective drugs, health care products, cosmetics, and agricultural and animal husbandry products to benefit mankind.

The Extracts of Polygonum cuspidatum Root and Rhizome Block the Entry of SARS-CoV-2 Wild-Type and Omicron Pseudotyped Viruses via Inhibition of the S-Protein and 3CL Protease

COVID-19, resulting from infection by the SARS-CoV-2 virus, caused a contagious pandemic. Even with the current vaccines, there is still an urgent need to develop effective pharmacological treatments against this deadly disease. Here, we show that the water and ethanol extracts of the root and rhizome of Polygonum cuspidatum (Polygoni Cuspidati Rhizoma et Radix), a common Chinese herbal medicine, blocked the entry of wild-type and the omicron variant of the SARS-CoV-2 pseudotyped virus into fibroblasts or zebrafish larvae, with IC₅₀ values ranging from 0.015 to 0.04 mg/mL. The extracts were shown to inhibit various aspects of the pseudovirus entry, including the interaction between the spike protein (S-protein) and the angiotensin-converting enzyme II (ACE2) receptor, and the 3CL protease activity. Out of the chemical compounds tested in this report, gallic acid, a phytochemical in P. cuspidatum, was shown to have a significant anti-viral effect. Therefore, this might be responsible, at least in part, for the anti-viral efficacy of the herbal extract. Together, our data suggest that the extracts of P. cuspidatum inhibit the entry of wild-type and the omicron variant of SARS-CoV-2, and so they could be considered as potent treatments against COVID-19.

Promising Role of Emodin as Therapeutics to Against Viral Infections

Emodin is an anthraquinone derivative that is widely present in natural plants and has a wide spectrum of pharmacological effects, such as antibacterial, anti-inflammatory, anti-fibrotic and anticancer and so on. Through reviewing studies on antiviral effect of emodin in the past decades, we found that emodin exhibits ability of inhibiting the infection and replication of more than 10 viruses in vitro and in vivo, including herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), coxsackievirus B (CVB), hepatitis B virus (HBV), influenza A virus (IAV), SARS-CoV, viral haemorrhagic septicaemia rhabdovirus (VHSV), enterovirus 71 (EV71), dengue virus serotype 2 (DENV-2) and Zika virus (ZIKV). Therefore, this review aims to summarize the antiviral effect of emodin, in order to provide reference and hopes to support the further investigations.

Combined Network Pharmacology, Molecular Docking, and Experimental Verification Approach to Investigate the Potential Mechanisms of Polydatin Against COVID-19

Background: Coronavirus disease 2019 (COVID-19) has posed a serious threat to human health and there is an urgent need for drug development. In this study, we explored the potential mechanisms underlying the efficacy of polydatin against COVID-19. Methods: A combined approach of network pharmacology, molecular docking, and experimental verification were employed in this study. Potential targets of polydatin for treating COVID-19 were obtained from multiple drug and disease databases. Protein–protein interaction and enrichment analyses were performed to predict the potential mechanism of action of polydatin against COVID-19. The binding potential of polydatin and key targets was evaluated through molecular docking. Furthermore, experimental methods including flow cytometry and luciferase assay were used to validate the results of computational analyses. Results: The main diseases identified as polydatin targets included metabolic diseases, lung diseases, inflammation, infectious diseases, and tumors. Polydatin may be used to treat COVID-19 through interventions that alter the immune and inflammatory responses, including IL-17 signaling pathway, T-cell activation, cytokines and inflammatory response, lipopolysaccharide-mediated signaling pathway, as well as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) innate immunity evasion and cell-specific immune response. Polydatin can potentially bind to the target proteins related to COVID-19, such as SARS-CoV-2 Mpro, RdRp, and human angiotensin-converting enzyme 2 (ACE2), while directly exerting its regulatory or therapeutic functions. The experimental results showed that polydatin decreased the infectivity of the SARS-CoV-2 spike pseudovirus in HEK293T-ACE2 cells. Accordingly, polydatin may retard the entry of SARS-CoV-2 into cells by competitively binding to human ACE2. Conclusion: The potential targets and signaling pathways of polydatin against COVID-19 were preliminarily identified. The findings may benefit the development and application of polydatin as a treatment for COVID-19.

The Importance of Nutraceuticals in COVID-19: What's the Role of Resveratrol?

Since COVID-19 has affected global public health, there has been an urgency to find a solution to limit both the number of infections, and the aggressiveness of the disease once infected. The main characteristic of this infection is represented by a strong alteration of the immune system which, day by day, increases the risk of mortality, and can lead to a multiorgan dysfunction. Because nutritional profile can influence patient’s immunity, we focus our interest on resveratrol, a polyphenolic compound known for its immunomodulating and anti-inflammatory properties. We reviewed all the information concerning the different roles of resveratrol in COVID-19 pathophysiology using PubMed and Scopus as the main databases. Interestingly, we find out that resveratrol may exert its role through different mechanisms. In fact, it has antiviral activity inhibiting virus entrance in cells and viral replication. Resveratrol also improves autophagy and decreases pro-inflammatory agents expression acting as an anti-inflammatory agent. It regulates immune cell response and pro-inflammatory cytokines and prevents the onset of thrombotic events that usually occur in COVID-19 patients. Since resveratrol acts through different mechanisms, the effect could be enhanced, making a totally natural agent particularly effective as an adjuvant in anti COVID-19 therapy.

Screening of Antiviral Components of Yinhuapinggan Granule and Protective Effects of Yinhuapinggan Granule on MDCK Cells with Influenza A/H1N1 Virus

Background. Traditional Chinese medicine Yinhuapinggan granule (YHPG) has been used for treating upper respiratory tract infection like influenza, cough, and viral pneumonia. However, its active ingredients that really exert the main efficacy have not been well elucidated. This study is aimed at screening its antiviral components and investigating the potential therapeutic mechanisms of YHPG against the influenza A/PR8/34 (H1N1) virus in Madin Darby canine kidney (MDCK). Methods. MDCK cells were infected with the influenza virus and then treated with ribavirin, YHPG, and main active ingredients in YHPG. Based on the maximum nontoxic concentration (TC0), half-maximal toxic concentration (TC50), half-maximal inhibitory concentration (IC50), and therapeutic index (TI), interferon-β (IFN-β) and interleukin-6 (IL-6) levels were measured using enzyme-linked immunosorbent assay (ELISA), and the gene expression of TLR7, MyD88, tumor necrosis factor receptor-associated factor 6 (TRAF6), c-Jun amino terminal kinase (JNK), p38 mitogen-activated protein kinase (p38 MAPK), and p65 nuclear transcription factor-kappa B (p65 NF-κB) was quantified using reverse transcription-polymerase chain reaction (RT-PCR). Results. The results indicated that the components of YHPG, such as ephedrine hydrochloride, pseudoephedrine hydrochloride, chlorogenic acid, and emodin, had significant antiviral effects. High and medium doses of YHPG effectively reduced the cytopathic effect (CPE) and significantly decreased IFN-β and IL-6 levels in the supernatant. Simultaneously, the transcript levels of TLR7, MyD88, TRAF6, JNK, p38 MAPK, and p65 NF-κB decreased in infected MDCK cells. Moreover, a certain dose-dependent relationship among different groups of YHPG was observed. Conclusions. These results indicated that YHPG and the components of YHPG had a significant inhibitory function on the proliferation of the H1N1 virus. The mechanism might be associated with suppressing the activation of the TLR7/MyD88 signaling pathway, a decrease in the mRNA expression of key target genes, and inhibition of IFN-β and IL-6 secretion.

COVID-19 Risk Appears to Vary Across Different Alcoholic Beverages

Objectives: To evaluate the associations of status, amount, and frequency of alcohol consumption across different alcoholic beverages with coronavirus disease 2019 (COVID-19) risk and associated mortality. Methods: This study included 473,957 subjects, 16,559 of whom tested positive for COVID-19. Multivariate logistic regression analyses were used to evaluate the associations of alcohol consumption with COVID-19 risk and associated mortality. The non-linearity association between the amount of alcohol consumption and COVID-19 risk was evaluated by a generalized additive model. Results: Subjects who consumed alcohol double above the guidelines had a higher risk of COVID-19 (1.12 [1.00, 1.25]). Consumption of red wine above or double above the guidelines played protective effects against the COVID-19. Consumption of beer and cider increased the COVID-19 risk, regardless of the frequency and amount of alcohol intake. Low-frequency of consumption of fortified wine (1-2 glasses/week) within guidelines had a protective effect against the COVID-19. High frequency of consumption of spirits (≥5 glasses/week) within guidelines increased the COVID-19 risk, whereas the high frequency of consumption of white wine and champagne above the guidelines decreased the COVID-19 risk. The generalized additive model showed an increased risk of COVID-19 with a greater number of alcohol consumption. Alcohol drinker status, frequency, amount, and subtypes of alcoholic beverages were not associated with COVID-19 associated mortality. Conclusions: The COVID-19 risk appears to vary across different alcoholic beverage subtypes, frequency, and amount. Red wine, white wine, and champagne have chances to reduce the risk of COVID-19. Consumption of beer and cider and spirits and heavy drinking are not recommended during the epidemics. Public health guidance should focus on reducing the risk of COVID-19 by advocating healthy lifestyle habits and preferential policies among consumers of beer and cider and spirits.

Potential therapeutic effect of Shufeng Jiedu capsule and its major herbs on coronavirus disease 2019 (COVID-19): A review

The outbreak and rapid spread of coronavirus disease 2019 (COVID-19) poses a huge threat to human health and social stability. Shufeng Jiedu capsule (SFJDC), a patented herbal drug composed of eight medicinal plants, is used to treat different viral respiratory tract infectious diseases. Based on its antiviral, anti-inflammatory, and immunoregulatory activities in acute lung injury, SFJDC can be effectively used as a treatment for COVID-19 patients according to the diagnosis and treatment plan issued in China and existing clinical data. SFJDC has been recommended in 15 therapeutic regimens for COVID-19 in China. This review summarizes current data on the ingredients, chemical composition, pharmacological properties, clinical efficacy, and potential therapeutic effect of SFJDC on COVID-19, to provide a theoretical basis for its anti-viral mechanism and the clinical treatment of COVID-19.

Photodynamic Inactivation of Human Coronaviruses

Photodynamic inactivation (PDI) employs a photosensitizer, light, and oxygen to create a local burst of reactive oxygen species (ROS) that can inactivate microorganisms. The botanical extract PhytoQuin^TM is a powerful photosensitizer with antimicrobial properties. We previously demonstrated that photoactivated PhytoQuin also has antiviral properties against herpes simplex viruses and adenoviruses in a dose-dependent manner across a broad range of sub-cytotoxic concentrations. Here, we report that human coronaviruses (HCoVs) are also susceptible to photodynamic inactivation. Photoactivated-PhytoQuin inhibited the replication of the alphacoronavirus HCoV-229E and the betacoronavirus HCoV-OC43 in cultured cells across a range of sub-cytotoxic doses. This antiviral effect was light-dependent, as we observed minimal antiviral effect of PhytoQuin in the absence of photoactivation. Using RNase protection assays, we observed that PDI disrupted HCoV particle integrity allowing for the digestion of viral RNA by exogenous ribonucleases. Using lentiviruses pseudotyped with the SARS-CoV-2 Spike (S) protein, we once again observed a strong, light-dependent antiviral effect of PhytoQuin, which prevented S-mediated entry into human cells. We also observed that PhytoQuin PDI altered S protein electrophoretic mobility. The PhytoQuin constituent emodin displayed equivalent light-dependent antiviral activity to PhytoQuin in matched-dose experiments, indicating that it plays a central role in PhytoQuin PDI against CoVs. Together, these findings demonstrate that HCoV lipid envelopes and proteins are damaged by PhytoQuin PDI and expands the list of susceptible viruses.

Risk of inflammatory bowel disease appears to vary across different frequency, amount, and subtype of alcoholic beverages

Objective

Inflammatory bowel disease (IBD) and alcohol use has become a significant and growing public health concern. Alcohol use has been reported to be the most-avoided diet item among IBD patients. However, knowledge regarding the impact of different classes of alcoholic beverages on the management of IBD is limited. Our study aims to evaluate the association of different frequencies, amounts, and subtypes of alcoholic beverages with IBD risk.

Methods

The UK Biobank comprised 7,095 subjects with IBD and 4,95,410 subjects without IBD. Multivariate Logistic regression, stratifying analysis, and interaction terms were used to estimate the odds ratios (ORs) and 95% confidence intervals (95% CIs) of IBD. A generalized additive model was used to evaluate the linearity associations of the total amount of all alcoholic beverages or that of each of five alcoholic beverages with IBD risk.

Results

Compared with non-drinkers, the IBD risk was 12 to 16% lower in red wine consumers (1-2 glasses/week, OR [95%CI], 0.88 [0.80, 0.97]; 3-4 glasses/week, 0.84 [0.76, 0.93]; ≥5 glasses/week, 0.86 [0.78, 0.95]), whereas 12% higher in white wine and champagne consumers (1-2 glasses/week, 1.12 [1.03, 1.22]). Stratifying analysis showed low-frequency red wine consumers were associated with a lower IBD risk (0.85 [0.74, 0.97]), whereas spirits consumers were associated with a higher risk (1.28 [1.03, 1.59]). High doge of red wine consumers were associated with a lower IBD risk (above guidelines, 0.80 [0.67, 0.97]; double above, 0.83 [0.71, 0.97]), whereas high doge white wine and champagne (1.32 [1.09, 1.61]) and beer and cider (1.26 [1.02, 1.54]) consumers were associated with a higher IBD risk. White wine and champagne showed a significant interaction effect with high doge alcohol consumption (1.27 [1.03-1.58], p = 0.029). The dose-response association showed an increased IBD risk with more number of alcohol consumption of white wine and champagne, beer and cider, or the total amount of all alcoholic beverages. However, red wine is at low risk across the whole dose cycle.

Conclusions

The IBD risk appears to vary across different frequencies, amounts, and subtypes of alcoholic beverages. Overall, alcohol intake is not recommended.

Polyphenols as Potential Inhibitors of SARS-CoV-2 RNA Dependent RNA Polymerase (RdRp)

An increasing number of studies have demonstrated the antiviral nature of polyphenols, and many polyphenols have been proposed to inhibit SARS-CoV or SARS-CoV-2. Our previous study revealed the inhibitory mechanisms of polyphenols against DNA polymerase α and HIV reverse transcriptase to show that polyphenols can block DNA elongation by competing with the incoming NTPs. Here we applied computational approaches to examine if some polyphenols can also inhibit RNA polymerase (RdRp) in SARS-CoV-2, and we identified some better candidates than remdesivir, the FDA-approved drug against RdRp, in terms of estimated binding affinities. The proposed compounds will be further examined to develop new treatments for COVID-19.

Delineating a potent antiviral activity of Cuphea ignea extract loaded nano-formulation against SARS-CoV-2: In silico and in vitro studies

The outbreak of coronavirus disease-2019, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a worldwide emerging crisis. Polyphenols are a class of herbal metabolites with a broad-spectrum antiviral activity. However, most polyphenols encounter limited efficacy due to their poor solubility and degradation in neutral and basic environments. Thus, the effectiveness of their pharmaceutical application is critically dependent on the delivery systems to overcome the aforementioned drawbacks. Herein, Polyphenols-rich Cuphea ignea extract was prepared and its constituents were identified and quantified. Molecular docking was conducted for 15 compounds in the extract against SARS-CoV-2 main protease, among which rutin, myricetin-3-O-rhamnoside and rosmarinic acid depicted the most promising antiviral activity. Further, a self-nanoemulsifying formulation, composed of 10% oleic acid, 40% tween 20 and propylene glycol 50%, was prepared to improve the solubility of the extract components and enable its concurrent delivery permitting combined potency. Upon dilution with aqueous phases, the formulation rapidly Formsnanoemulsion of good stability and excellent dissolution profile in acidic pH when compared to the crude extract. It inhibited SARS-CoV-2 completely in vitro at a concentration as low as 5.87 μg/mL presenting a promising antiviral remedy for SARS-CoV-2, which may be attributed to the possible synergism between the extract components.

Protective Role of Combined Polyphenols and Micronutrients against Influenza A Virus and SARS-CoV-2 Infection In Vitro

Polyphenols have been widely studied for their antiviral effect against respiratory virus infections. Among these, resveratrol (RV) has been demonstrated to inhibit influenza virus replication and more recently, it has been tested together with pterostilbene against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In the present work, we evaluated the antiviral activity of polydatin, an RV precursor, and a mixture of polyphenols and other micronutrients, named A5+, against influenza virus and SARS-CoV-2 infections. To this end, we infected Vero E6 cells and analyzed the replication of both respiratory viruses in terms of viral proteins synthesis and viral titration. We demonstrated that A5+ showed a higher efficacy in inhibiting both influenza virus and SARS-CoV-2 infections compared to polydatin treatment alone. Indeed, post infection treatment significantly decreased viral proteins expression and viral release, probably by interfering with any step of virus replicative cycle. Intriguingly, A5+ treatment strongly reduced IL-6 cytokine production in influenza virus-infected cells, suggesting its potential anti-inflammatory properties during the infection. Overall, these results demonstrate the synergic and innovative antiviral efficacy of A5+ mixture, although further studies are needed to clarify the mechanisms underlying its inhibitory effect.

Modulating Neurological Complications of Emerging Infectious Diseases: Mechanistic Approaches to Candidate Phytochemicals

Growing studies are revealing the critical manifestations of influenza, dengue virus (DENV) infection, Zika virus (ZIKV) disease, and Ebola virus disease (EVD) as emerging infectious diseases. However, their corresponding mechanisms of major complications headed for neuronal dysfunction are not entirely understood. From the mechanistic point of view, inflammatory/oxidative mediators are activated during emerging infectious diseases towards less cell migration, neurogenesis impairment, and neuronal death. Accordingly, the virus life cycle and associated enzymes, as well as host receptors, cytokine storm, and multiple signaling mediators, are the leading players of emerging infectious diseases. Consequently, chemokines, interleukins, interferons, carbohydrate molecules, toll-like receptors (TLRs), and tyrosine kinases are leading orchestrates of peripheral and central complications which are in near interconnections. Some of the resulting neuronal manifestations have attracted much attention, including inflammatory polyneuropathy, encephalopathy, meningitis, myelitis, stroke, Guillain-Barré syndrome (GBS), radiculomyelitis, meningoencephalitis, memory loss, headaches, cranial nerve abnormalities, tremor, and seizure. The complex pathophysiological mechanism behind the aforementioned complications urges the need for finding multi-target agents with higher efficacy and lower side effects. In recent decades, the natural kingdom has been highlighted as promising neuroprotective natural products in modulating several dysregulated signaling pathways/mediators. The present study provides neuronal manifestations of some emerging infectious diseases and underlying pathophysiological mechanisms. Besides, a mechanistic-based strategy is developed to introduce candidate natural products as promising multi-target agents in combating major dysregulated pathways towards neuroprotection in influenza, DENV infection, ZIKV disease, and EVD.

Polyphenols as alternative treatments of COVID-19

Although scientists around the world have put lots of effort into the development of new treatments for COVID-19 since the outbreak, no drugs except Veklury (remdesivir) have been approved by FDA. There is an urgent need to discover some alternative antiviral treatment for COVID-19. Because polyphenols have been shown to possess antiviral activities, here we conducted a large-scale virtual screening for more than 400 polyphenols. Several lead compounds such as Petunidin 3-O-(6″-p-coumaroyl-glucoside) were identified to have promising binding affinities and convincing binding mechanisms. Analyzing the docking results and ADME properties sheds light on the potential efficacy of the top-ranked drug candidates and pinpoints the key residues on the target proteins for the future of drug development.

Anticoronavirus and Immunomodulatory Phenolic Compounds: Opportunities and Pharmacotherapeutic Perspectives

In 2019, COVID-19 emerged as a severe respiratory disease that is caused by the novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The disease has been associated with high mortality rate, especially in patients with comorbidities such as diabetes, cardiovascular and kidney diseases. This could be attributed to dysregulated immune responses and severe systemic inflammation in COVID-19 patients. The use of effective antiviral drugs against SARS-CoV-2 and modulation of the immune responses could be a potential therapeutic strategy for COVID-19. Studies have shown that natural phenolic compounds have several pharmacological properties, including anticoronavirus and immunomodulatory activities. Therefore, this review discusses the dual action of these natural products from the perspective of applicability at COVID-19.

Can Resveratrol-Inhaled Formulations Be Considered Potential Adjunct Treatments for COVID-19?

The pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has led to an extraordinary threat to the global healthcare system. This infection disease, named COVID-19, is characterized by a wide clinical spectrum, ranging from asymptomatic or mild upper respiratory tract illness to severe viral pneumonia with fulminant cytokine storm, which leads to respiratory failure. To improve patient outcomes, both the inhibition of viral replication and of the unwarranted excessive inflammatory response are crucial. Since no specific antiviral drug has been proven effective for the treatment of patients and the only upcoming promising agents are monoclonal antibodies, inexpensive, safe, and widely available treatments are urgently needed. A potential anti-inflammatory molecule to be evaluated, which possesses antiviral activities in several experimental models, is the polyphenol resveratrol. This compound has been shown to inhibit SARS-CoV-2 replication in human primary bronchial epithelial cell cultures and to downregulate several pathogenetic mechanisms involved in COVID-19 severity. The use of resveratrol in clinical practice is limited by the low bioavailability following oral administration, due to the pharmacokinetic and metabolic characteristics of the molecule. Therefore, topical administration through inhaled formulations could allow us to achieve sufficiently high concentrations of the compound in the airways, the entry route of SARS-CoV-2.

A Comprehensive Study on the Antimicrobial Properties of Resveratrol as an Alternative Therapy

Resveratrol is a polyphenolic antioxidant whose possible health benefits include anticarcinogenic, antiaging, and antimicrobial properties that have gained significant attention. The compound is well accepted by individuals and has been commonly used as a nutraceutical in recent decades. Its widespread usage makes it essential to study as a single agent as well as in combination with traditional prescription antibiotics as regards to antimicrobial properties. Resveratrol demonstrates the action of antimicrobials against a remarkable bacterial diversity, viruses, and fungus. This report explains resveratrol as an all-natural antimicrobial representative. It may modify the bacterial virulence qualities resulting in decreased toxic substance production, biofilm inhibition, motility reduction, and quorum sensing disturbance. Moreover, in conjunction with standard antibiotics, resveratrol improves aminoglycoside efficacy versus Staphylococcus aureus, while it antagonizes the deadly function of fluoroquinolones against S. aureus and also Escherichia coli. The present study aimed to thoroughly review and study the antimicrobial potency of resveratrol, expected to help researchers pave the way for solving antimicrobial resistance.

Huanglian-Houpo drug combination ameliorates H1N1-induced mouse pneumonia via cytokines, antioxidant factors and TLR/MyD88/NF-κB signaling pathways

Huanglian-Houpo drug combination (HHDC) is a classical traditional Chinese medicine that has been effectively used to treat seasonal colds and flu. However, no systematic studies of the effects of HHDC on H1N1 influenza infection and the associated mechanisms have been reported. The aim of the present study was to determine the anti-H1N1 influenza effects of HHDC and explore the underlying mechanisms. A mouse model of H1N1-induced pneumonia was established and the mice were treated with HHDC (4, 8 and 16 g/kg) for 5 days after viral challenge. The antiviral effects of HHDC and the underlying mechanisms in the mice were investigated and evaluated with respect to inflammation, oxidative stress and Toll-like receptor (TLR)/myeloid differentiation factor (MyD88)/nuclear factor (NF)-κB signaling pathways. HHDC provided significant protection against weight loss and reduced the H1N1 viral load in the lungs. In addition, HHDC significantly decreased the lung index and increased the spleen and thymus indices of the H1N1-infected mice. HHDC also significantly ameliorated the histopathological changes of pneumonia, decreased serum levels of the cytokines interleukin (IL)-6, tumor necrosis factor-α and interferon-γ, and increased the serum level of IL-2. Moreover, HHDC significantly increased the levels of the antioxidant factors superoxide dismutase and glutathione, and reduced the serum level of nitric oxide. Furthermore, the mRNA and protein expression levels of TLR3, TLR7, MyD88, NF-κB p65 and tumor necrosis factor receptor-associated factor 3 in the lung tissues were significantly decreased by HHDC. These findings suggest that HHDC directly inhibited H1N1 infection in vivo and exerted a therapeutic effect on influenza-induced pneumonia in mice by modulating cytokines, antioxidant factors and TLR/MyD88/NF-κB signaling pathways.

Can Natural Polyphenols Help in Reducing Cytokine Storm in COVID-19 Patients?

SARS-CoV-2 first emerged in China during late 2019 and rapidly spread all over the world. Alterations in the inflammatory cytokines pathway represent a strong signature during SARS-COV-2 infection and correlate with poor prognosis and severity of the illness. The hyper-activation of the immune system results in an acute severe systemic inflammatory response named cytokine release syndrome (CRS). No effective prophylactic or post-exposure treatments are available, although some anti-inflammatory compounds are currently in clinical trials. Studies of plant extracts and natural compounds show that polyphenols can play a beneficial role in the prevention and the progress of chronic diseases related to inflammation. The aim of this manuscript is to review the published background on the possible effectiveness of polyphenols to fight SARS-COV-2 infection, contributing to the reduction of inflammation. Here, some of the anti-inflammatory therapies are discussed and although great progress has been made though this year, there is no proven cytokine blocking agents for COVID currently used in clinical practice. In this regard, bioactive phytochemicals such as polyphenols may become promising tools to be used as adjuvants in the treatment of SARS-CoV-2 infection. Such nutrients, with anti-inflammatory and antioxidant properties, associated to classical anti-inflammatory drugs, could help in reducing the inflammation in patients with COVID-19.

Preliminary study of Yinhuapinggan granule against H1N1 influenza virus infection in mice through inhibition of apoptosis

CONTEXT

Yinhuapinggan granule (YHPG) is frequently used for treating fever, cough, and viral pneumonia in traditional Chinese medicine.

OBJECTIVE

This study investigated the antiviral effects of YHPG in H1N1 influenza virus (IFV)-infected mice and its possible mechanism.

MATERIALS AND METHODS

ICR mice were intranasally infected with 10 LD₅₀ viral dose of IFV and then oral administration of YHPG (6, 12, and 18 g/kg) or oseltamivir (positive control) once a day for 2 or 4 consecutive days, six mice in each group. The lung, spleen and thymus indexes of IFV-infected mice, the expression of viral loads and pathological changes in lung tissues were performed to evaluate the antiviral effects of YHPG. Real-time PCR, immunohistochemistry and western blot assays were used to determine the expression of Bax, Bcl-2 and caspase-3.

RESULTS

LD₅₀ in mice was 10^-3.5/0.02 mL. YHPG (6, 12, and 18 g/kg) dose-dependently decreased the lung index and viral load; the inhibition ratio of lung index was 5.31, 18.22, and 34.06%, respectively. Further detection revealed that YHPG (12 and 18 g/kg) significantly attenuated lung pathological changes, and increased the spleen and thymus indexes. Moreover, YHPG significantly down-regulated the mRNA and protein expression of Bax and caspase-3 in lung tissues of mice infected with IFV, and up-regulated the expression of Bcl-2.

CONCLUSIONS

YHPG has significant antiviral effects in IFV-infected mice, partially by inhibiting influenza virus replication and regulating the occurrence of apoptosis induced by influenza virus infection, suggesting that YHPG may be a promising antiviral agent with potential clinical application prospects.

The upshot of Polyphenolic compounds on immunity amid COVID-19 pandemic and other emerging communicable diseases: An appraisal

Polyphenols are a large family of more than 10,000 naturally occurring compounds, which exert countless pharmacological, biological and physiological benefits for human health including several chronic diseases such as cancer, diabetes, cardiovascular, and neurological diseases. Their role in traditional medicine, such as the use of a wide range of remedial herbs (thyme, oregano, rosemary, sage, mint, basil), has been well and long known for treating common respiratory problems and cold infections. This review reports on the most highlighted polyphenolic compounds present in up to date literature and their specific antiviral perceptive properties that might enhance the body immunity facing COVID-19, and other viral infectious diseases. In fact, several studies and clinical trials increasingly proved the role of polyphenols in controlling numerous human pathogens including SARS and MERS, which are quite similar to COVID-19 through the enhancement of host immune response against viral infections by different biological mechanisms. Thus, polyphenols ought to be considered as a potential and valuable source for designing new drugs that could be used effectively in the combat against COVID-19 and other rigorous diseases.

Cell Clearing Systems as Targets of Polyphenols in Viral Infections: Potential Implications for COVID-19 Pathogenesis

The novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has generated the ongoing coronavirus disease-2019 (COVID-19) pandemic, still with an uncertain outcome. Besides pneumonia and acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), other features became evident in the context of COVID-19. These includes endothelial and coagulation dysfunction with disseminated intravascular coagulation (DIC), and multiple organ dysfunction syndrome (MODS), along with the occurrence of neurological alterations. The multi-system nature of such viral infection is a witness to the exploitation and impairment of ubiquitous subcellular and metabolic pathways for the sake of its life-cycle, ranging from host cell invasion, replication, transmission, up to a cytopathic effect and overt systemic inflammation. In this frame, alterations in cell-clearing systems of the host are emerging as a hallmark in the pathogenesis of various respiratory viruses, including SARS-CoV-2. Indeed, exploitation of the autophagy and proteasome pathways might contribute not only to the replication of the virus at the site of infection but also to the spreading of either mature virions or inflammatory mediators at both cellular and multisystem levels. In this frame, besides a pharmacological therapy, many researchers are wondering if some non-pharmacological substances might counteract or positively modulate the course of the infection. The pharmacological properties of natural compounds have gained increasing attention in the field of alternative and adjunct therapeutic approaches to several diseases. In particular, several naturally-occurring herbal compounds (mostly polyphenols) are reported to produce widespread antiviral, anti-inflammatory, and anti-oxidant effects while acting as autophagy and (immuno)-proteasome modulators. This article attempts to bridge the perturbation of autophagy and proteasome pathways with the potentially beneficial effects of specific phytochemicals and flavonoids in viral infections, with a focus on the multisystem SARS-CoV-2 infection.

Herbal medicine, a reliable support in COVID therapy

At present, specific therapies for COVID-19 are not well established, being certain only that the immune system plays a decisive role in the initiation and progression of the disease. Plants have given and continue to give compounds with great efficiency and low toxicity, some of them being a starting point for extremely effective synthetic substances. Although herbal remedies are used mainly for preventive purposes, there are also guidelines issued by some countries that indicate the use of traditional remedies for different stages of COVID-19 disease.Europe has a long and strong tradition of using medicinal plants for therapeutic purposes, but clinical trials for this type of approach are scarce, compared to Asia. In this regard, a bridge between tradition and science, would have a strong impact on the capacity for prevention and treatment of COVID-19. The paper reviews compounds of plant origin that have previously proven effective in counteracting some coronaviruses but also some of their major effects - direct action on virus replicative apparatus (viral entry or replication, action on the viral enzymatic system), collateral action of natural compounds on the immune system and also the contribution of herbal medicine as vaccine adjuvants are tackled.

Screening for Anti-Influenza Actives of Prefractionated Traditional Chinese Medicines

Traditional Chinese medicines (TCMs) have proven to possess advantages in counteracting virus infections according to clinical practices. It's therefore of great value to discover novel antivirals from TCMs. In this paper, One hundred medicinal plants which have been included in TCM prescriptions for antiviral treatment were selected and prefractionated into 5 fractions each by sequentially using cyclohexane, dichloromethane, ethyl acetate, n-butanol, and water. 500 TCM-simplified extracts were then subjected to a phenotypic screening using a recombinant IAV expressing Gaussia luciferase. Ten TCM fractions were identified to possess antiviral activities against influenza virus. The IC50's of the hit fractions range from 1.08 to 6.45 μg/mL, while the SIs, from 7.52 to 98.40. Furthermore, all the ten hit fractions inhibited the propagation of progeny influenza virus significantly at 20 μg/mL. The hit TCM fractions deserve further isolation for responsible constituents leading towards anti-influenza drugs. Moreover, a library consisting of 500 simplified TCM extracts was established, facilitating antiviral screening in quick response to emerging and re-emerging viruses such as Ebola virus and current SARS-CoV-2 pandemic.

Identification of the phytobioactive Polygonum cuspidatum as an antiviral source for restricting dengue virus entry

Dengue virus (DENV) is a mosquito-borne pathogen that is becoming a serious global threat, owing to its rising incidence in inter-tropical regions that yield over 50 million annual infections. There are currently no approved antiviral agents for the management of dengue, and recent shortcomings in its immunization called for immediate action to develop effective drugs with prophylactic ability to better manage its infection. In an attempt to discover novel antiviral sources, we identified the medicinal herb Polygonum cuspidatum (PC) as a bioactive botanical material against DENV infectivity. Specifically, the methanolic extract from PC rhizomes (PCME) potently inhibited DENV infection without causing significant cytotoxicity. Further examination on the viral life cycle demonstrated that PCME particularly targeted the initial stages of DENV infection, while pre- and post-infection treatments had no effect. More importantly, the PCME could efficiently inactivate DENV free virus particles and block the viral attachment and entry/fusion events without apparently influencing viral replication, egress, and cell-to-cell spread. The antiviral effect of PCME was also recapitulated in infection analysis using DENV pseudoparticles displaying viral structural proteins that mediate DENV particle entry. Besides, PCME treatment also inhibited direct DENV entry into several cell types relevant to its infection and reduced viral infectivity of other members of the Flaviviridae family, including the hepatitis C virus (HCV) and Zika virus (ZIKV). Due to its potency against DENV entry, we suggest that the phytobioactive extract from PC is an excellent starting point as an antiviral source material for further development of therapeutic strategies in the prophylactic management of DENV infection.

Can phytotherapy with polyphenols serve as a powerful approach for the prevention and therapy tool of novel coronavirus disease 2019 (COVID-19)?

Much more serious than the previous severe acute respiratory syndrome (SARS) coronavirus (CoV) outbreaks, the novel SARS-CoV-2 infection has spread speedily, affecting 213 countries and causing ∼17,300,000 cases and ∼672,000 (∼+1,500/day) deaths globally (as of July 31, 2020). The potentially fatal coronavirus disease (COVID-19), caused by air droplets and airborne as the main transmission modes, clearly induces a spectrum of respiratory clinical manifestations, but it also affects the immune, gastrointestinal, hematological, nervous, and renal systems. The dramatic scale of disorders and complications arises from the inadequacy of current treatments and absence of a vaccine and specific anti-COVID-19 drugs to suppress viral replication, inflammation, and additional pathogenic conditions. This highlights the importance of understanding the SARS-CoV-2 mechanisms of actions and the urgent need of prospecting for new or alternative treatment options. The main objective of the present review is to discuss the challenging issue relative to the clinical utility of plants-derived polyphenols in fighting viral infections. Not only is the strong capacity of polyphenols highlighted in magnifying health benefits, but the underlying mechanisms are also stressed. Finally, emphasis is placed on the potential ability of polyphenols to combat SARS-CoV-2 infection via the regulation of its molecular targets of human cellular binding and replication, as well as through the resulting host inflammation, oxidative stress, and signaling pathways.

Coronavirus in human diseases: Mechanisms and advances in clinical treatment

Coronaviruses (CoVs), a subfamily of coronavirinae, are a panel of single-stranded RNA virus. Human coronavirus (HCoV) strains (HCoV-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63) usually cause mild upper respiratory diseases and are believed to be harmless. However, other HCoVs, associated with severe acute respiratory syndrome, Middle East respiratory syndrome, and COVID-19, have been identified as important pathogens due to their potent infectivity and lethality worldwide. Moreover, currently, no effective antiviral drugs treatments are available so far. In this review, we summarize the biological characters of HCoVs, their association with human diseases, and current therapeutic options for the three severe HCoVs. We also highlight the discussion about novel treatment strategies for HCoVs infections.

May Polyphenols Have a Role Against Coronavirus Infection? An Overview of in vitro Evidence

The coronavirus infection is constantly diffusing worldwide and the incidence of death is dramatically increasing, representing one of the greatest disasters in human history. Nowadays, no effective therapeutic approaches have been licensed, despite the rising interest of the scientific research in this specific field, and the daily growing number of publications, while the need to find novel strategies is urgent. Evidence in the literature reported the antiviral activity of polyphenols, the largest class of bioactive compounds in nature. Interestingly, a limited number of studies investigated the efficacy of polyphenols from different raw materials, directly against coronaviruses. The present manuscript aimed to report this evidence and provide a viewpoint on the possibility to use it as a start point for the development of novel natural approaches against this viral infection, eventually designing further appropriate researches.

Resveratrol plus carboxymethyl-β-glucan in infants with common cold: A randomized double-blind trial

Objectives

To evaluate effectiveness of a nasal resveratrol/carboxymethyl-β-glucan solution compared to nasal saline solution: a) on common cold symptoms by means of a validated measure scale (CARIFS score), b) on Rhinovirus infection and CCL2, CCL5, IL8, IL6, CXCL10 and TLR2 expression in nasal swabs, c) on frequency of relapses after 30 days of follow-up.

Methods

89 infants with respiratory infection symptoms were randomly assigned to receive either a nasal resveratrol/carboxymethyl-β-glucan solution or nasal saline solution.

All patients were evaluated with CARIFS score at enrollment, after 48 h, 7 and 30 days by physicians and parents. Nasal swabs were obtained at enrollment, after 48 h and after one week.

Results

CARIFS score improved in both groups. Episodes of sneezing and cough were fewer in study group after 7 days of follow-up (p < 0.05). No significant differences were found on nasopharyngeal swabs in Rhinovirus detection and cytokines expression after 48 h, nor in 30 days relapses. TLR2 expression was significantly higher in Rhinovirus infected children of the study group. No adverse effects occurred.

Conclusions

These data suggest that a solution containing resveratrol plus carboxymethyl-β-glucan might have a positive impact on both clinical and socio-economic burden due to infant common cold.

Photodynamic Inactivation of Herpes Simplex Viruses

Herpes simplex virus (HSV) infections can be treated with direct acting antivirals like acyclovir and foscarnet, but long-term use can lead to drug resistance, which motivates research into broadly-acting antivirals that can provide a greater genetic barrier to resistance. Photodynamic inactivation (PDI) employs a photosensitizer, light, and oxygen to create a local burst of reactive oxygen species that inactivate microorganisms. The botanical plant extract Orthoquin^TM is a powerful photosensitizer with antimicrobial properties. Here we report that Orthoquin also has antiviral properties. Photoactivated Orthoquin inhibited herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) infection of target cells in a dose-dependent manner across a broad range of sub-cytotoxic concentrations. HSV inactivation required direct contact between Orthoquin and the inoculum, whereas pre-treatment of target cells had no effect. Orthoquin did not cause appreciable damage to viral capsids or premature release of viral genomes, as measured by qPCR for the HSV-1 genome. By contrast, immunoblotting for HSV-1 antigens in purified virion preparations suggested that higher doses of Orthoquin had a physical impact on certain HSV-1 proteins that altered protein mobility or antigen detection. Orthoquin PDI also inhibited the non-enveloped adenovirus (AdV) in a dose-dependent manner, whereas Orthoquin-mediated inhibition of the enveloped vesicular stomatitis virus (VSV) was light-independent. Together, these findings suggest that the broad antiviral effects of Orthoquin-mediated PDI may stem from damage to viral attachment proteins.

Emodin Inhibition of Influenza A Virus Replication and Influenza Viral Pneumonia via the Nrf2, TLR4, p38/JNK and NF-kappaB Pathways

Lasting activations of toll-like receptors (TLRs), MAPK and NF-κB pathways can support influenza A virus (IAV) infection and promote pneumonia. In this study, we have investigated the effect and mechanism of action of emodin on IAV infection using qRT-PCR, western blotting, ELISA, Nrf2 luciferase reporter, siRNA and plaque inhibition assays. The results showed that emodin could significantly inhibit IAV (ST169, H1N1) replication, reduce IAV-induced expressions of TLR2/3/4/7, MyD88 and TRAF6, decrease IAV-induced phosphorylations of p38/JNK MAPK and nuclear translocation of NF-κB p65. Emodin also activated the Nrf2 pathway, decreased ROS levels, increased GSH levelss and GSH/GSSG ratio, and upregulated the activities of SOD, GR, CAT and GSH-Px after IAV infection. Suppression of Nrf2 via siRNA markedly blocked the inhibitory effects of emodin on IAV-induced activations of TLR4, p38/JNK, and NF-κB pathways and on IAV-induced production of IL-1β, IL-6 and expression of IAV M2 protein. Emodin also dramatically increased the survival rate of mice, reduced lung edema, pulmonary viral titer and inflammatory cytokines, and improved lung histopathological changes. In conclusion, emodin can inhibit IAV replication and influenza viral pneumonia, at least in part, by activating Nrf2 signaling and inhibiting IAV-induced activations of the TLR4, p38/JNK MAPK and NF-κB pathways.

Rheum emodin inhibits enterovirus 71 viral replication and affects the host cell cycle environment

Human enterovirus 71 (EV71) is the primary causative agent of recent large-scale outbreaks of hand, foot, and mouth disease (HFMD) in Asia. Currently, there are no drugs available for the prevention and treatment of HFMD. In this study, we compared the anti-EV71 activities of three natural compounds, rheum emodin, artemisinin and astragaloside extracted from Chinese herbs Chinese rhubarb, Artemisia carvifolia and Astragalus, respectively, which have been traditionally used for the treatment and prevention of epidemic diseases. Human lung fibroblast cell line MRC5 was mock-infected or infected with EV71, and treated with drugs. The cytotoxicity of the drugs was detected with MTT assay. The cytopathic effects such as cell death and condensed nuclei were morphologically observed. The VP1-coding sequence required for EV71 genome replication was assayed with qRT-PCR. Viral protein expression was analyzed with Western blotting. Viral TCID50 was determined to evaluate EV71 virulence. Flow cytometry analysis of propidium iodide staining was performed to analyze the cell cycle distribution of MRC5 cells. Rheum emodin (29.6 μmol/L) effectively protected MRC5 cells from EV71-induced cytopathic effects, which resulted from the inhibiting viral replication: rheum emodin treatment decreased viral genomic levels by 5.34-fold, viral protein expression by less than 30-fold and EV71 virulence by 0.33107-fold. The fact that inhibition of rheum emodin on viral virulence was much stronger than its effects on genomic levels and viral protein expression suggested that rheum emodin inhibited viral maturation. Furthermore, rheum emodin treatment markedly diminished cell cycle arrest at S phase in MRC5 cells, which was induced by EV71 infection and favored the viral replication. In contrast, neither astragaloside (50 μmol/L) nor artemisinin (50 μmol/L) showed similar anti-EV71 activities. Among the three natural compounds tested, rheum emodin effectively suppressed EV71 viral replication, thus is a candidate anti-HFMD drug.

Effective inhibition of MERS-CoV infection by resveratrol

BACKGROUND

Middle East Respiratory Syndrome coronavirus (MERS-CoV) is an emerging viral pathogen that causes severe morbidity and mortality. Up to date, there is no approved or licensed vaccine or antiviral medicines can be used to treat MERS-CoV-infected patients. Here, we analyzed the antiviral activities of resveratrol, a natural compound found in grape seeds and skin and in red wine, against MERS-CoV infection.

METHODS

We performed MTT and neutral red uptake assays to assess the survival rates of MERS-infected Vero E6 cells. In addition, quantitative PCR, western blotting, and immunofluorescent assays determined the intracellular viral RNA and protein expression. For viral productivity, we utilized plaque assays to confirm the antiviral properties of resveratrol against MERS-CoV.

RESULTS

Resveratrol significantly inhibited MERS-CoV infection and prolonged cellular survival after virus infection. We also found that the expression of nucleocapsid (N) protein essential for MERS-CoV replication was decreased after resveratrol treatment. Furthermore, resveratrol down-regulated the apoptosis induced by MERS-CoV in vitro. By consecutive administration of resveratrol, we were able to reduce the concentration of resveratrol while achieving inhibitory effectiveness against MERS-CoV.

CONCLUSION

In this study, we first demonstrated that resveratrol is a potent anti-MERS agent in vitro. We perceive that resveratrol can be a potential antiviral agent against MERS-CoV infection in the near future.

Potent bacterial neuraminidase inhibitors, anthraquinone glucosides from Polygonum cuspidatum and their inhibitory mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

P. cuspidatum is a popular Chinese medicinal herb, having a long history of usage in traditional Chinese medicine for the treatment of several inflammatory diseases in the form of powders and decoctions. Similarly there are many reports that P. cuspidatum has antibacterial and anti-inflammatory effects, both of which are properties associated with compounds having activity against bacterial neuraminidase (BNA).

AIM OF THE STUDY

We investigated whether P. cuspidatum's metabolites exhibited BNA inhibition. Consistent with our hypothesis, we found several inhibitors from the methanol extract of this plant, and then fully characterized their inhibitory mechanisms.

MATERIALS AND METHODS

Activity guided separation of methanol extract led to isolation of individual constituents, and subsequently their structures were elucidated by spectroscopic analysis. Detailed kinetic behaviors of BNA inhibitors were explored by showing the changes of K_m and V_max, the ratios of K_I/K_IS and K_ik/K_iv, and fluorescence quenching effect.

RESULTS AND CONCLUSION

This study attempted to isolate the responsible metabolites and elucidate the BNA inhibitory mechanism. The principal BNA inhibitory compounds (2-6) were identified as emodin (2), physcion-8-O-β-D-glucopyranoside (3), emodin-8-O-β-D-glucopyranoside (4), emodin-1-O-β-D-glucopyranoside (5), and 2-methoxy-6-acetyl-7-methyljuglone (6). Unexpectedly, anthraquinone glucosides (3-5) were much more potent than their corresponding aglycones (1 and 2). For example, emodin (2) had an IC₅₀=5.4μM, whereas its glucosides (4 and 5) had IC₅₀=0.85μM and 0.43μM respectively. A similar trend was observed with physcion (1, IC₅₀>200μM) and its glucoside (3, IC₅₀=6.2μM). The anthraquinone (2) was mixed type I inhibitor, whereas its glucosides (4 and 5) were noncompetitive. In addition, the fluorescence quenching study showed that the affinity constants (K_SV) of inhibitors increased in proportion to their inhibitory potencies. Furthermore, we quantified the major and minor metabolites through UPLC-PDA-Q-TOF/MS, and revealed that the most potent inhibitors were the major constituents. This result contributes to our understanding of P. cuspidatum utility as functional food stuff and widely used herbal medicine.

Antiviral effects of Yinhuapinggan granule against influenza virus infection in the ICR mice model

Yinhuapinggan granule (YHPG), a Chinese medicine granule based on Ma-Huang-Tang (Ephedra Decoction) and the clinical experience of Professor Wan Haitong, is used in traditional Chinese medicine (TCM) for the treatment of colds, influenza, fever, inflammation and cough. This study investigated the antiviral effects of YHPG on the production of inflammatory cytokines in influenza virus (IFV)-infected mice and evaluated the effect of YHPG on the expression of NF-κB p65 and the level of key signaling molecules in the TLR4 signaling pathway. ICR mice were orally administrated YHPG at doses of 7.5, 15 and 30 g kg(-1) day(-1) for 2 or 6 days after IFV infection. On days 3 and 7 after infection, YHPG (15 g/kg and 30 g/kg) significantly increased levels of interleukin (IL)-2 and interferon gamma and decreased levels of IL-4, IL-5 and tumor necrosis factor (TNF) in serum compared with the IFV control group. Furthermore, the expression of TLR4, MyD88, TRAF6 and NF-κB p65 at the mRNA and protein level was significantly lower in the YHPG (15 and 30 g/kg) treatment groups than in the IFV control group. These results suggest that YHPG has antiviral effects in IFV-infected mice, which is associated with the inhibition of the TLR4-MyD88-TRAF6 signaling pathway and the expression of NF-κB p65.

Resveratrol inhibits rhinovirus replication and expression of inflammatory mediators in nasal epithelia

Human rhinoviruses (HRV), the cause of common colds, are the most frequent precipitants of acute exacerbation of asthma and chronic obstructive pulmonary disease, as well as causes of other serious respiratory diseases. No vaccine or antiviral agents are available for the prevention or treatment of HRV infection. Resveratrol exerts antiviral effect against different DNA and RNA viruses. The antiviral effect of a new resveratrol formulation containing carboxymethylated glucan was analyzed in H1HeLa cell monolayers and ex vivo nasal epithelia infected with HRV-16. Virus yield was evaluated by plaque assay and expression of viral capsid proteins by Western blot. IL-10, IFN-β, IL-6, IL-8 and RANTES levels were evaluated by ELISA assay. ICAM-1 was assessed by Western blot and immunofluorescence. Resveratrol exerted a high, dose-dependent, antiviral activity against HRV-16 replication and reduced virus-induced secretion of IL-6, IL-8 and RANTES to levels similar to that of uninfected nasal epithelia. Basal levels of IL-6 and RANTES were also significantly reduced in uninfected epithelia confirming an anti-inflammatory effect of the compound. HRV-induced expression of ICAM-1 was reversed by resveratrol. Resveratrol may be useful for a therapeutic approach to reduce HRV replication and virus-induced cytokine/chemokine production.