Antiviral Activity of Interferon Alpha-2b and Taurine Combination Against SARS-CoV-2 in vitro.

Interferons (IFN) have antiviral activity against many viruses, including SARS-CoV-2. A combination of IFN-a2b and the antioxidant taurine is widely used in the Russian Federation, and its antiviral activity has not been studied before. The aim of this study was to determine the antiviral activity of interferon drugs, in combination with taurine and without it. The study included cytotoxicity and antiviral activity assays of IFN-a2b preparations, when stored according to the instructions at 2-8degreeC, and after 1 month storage at the temperature of 20-26degreeC in a pre-opened state. The combination of IFN alpha-2b with taurine has a higher antiviral activity compared to IFN alpha-2b mono-preparation by more than 25% at a <<low>> and 85% at a <<high>> multiplicity of infection. Selectivity index for combinations of IFN-a2b (50,000 IU/dose) + taurine (1 mg/ml) and IFN-a2b (10,000 IU/ml) + taurine (0.8 mg/ml) was more than 600 units, whereas for the IFN-a2b (10,000 IU/ml) it was 200 units. Antiviral activity does not change after one month at room temperature. The combination of interferon with taurine at high concentrations was less toxic than interferon. The results obtained demonstrate practicability of interferon alpha-2b and taurine combination use for treatment and prevention of COVID-19.Copyright © Team of Authors, 2022.

Ecofriendly aminochalcogenation of alkenes: a green alternative to obtain compounds with potential anti-SARS-CoV-2 activity

Here, we report a solvent- and metal-free methodology for the aminochalcogenation of alkenes, using molecular iodine as a catalyst, DMSO as a stoichiometric oxidant, and different nucleophiles under microwave irradiation. This ecofriendly approach provided the desired products with good to excellent yields in just 20 minutes. In addition, twenty compounds obtained by this methodology were referred for evaluation of potential antiviral activity against the coronavirus SARS-CoV-2. Two of the evaluated compounds (named 4d and 5b) showed potent antiviral activity, with a low cytotoxic profile resulting in a promising selectivity index.Copyright © 2023 The Royal Society of Chemistry.

Antiviral Activity of Interferon Alpha-2b and Taurine Combination Against SARS-CoV-2 in vitro

Interferons (IFN) have antiviral activity against many viruses, including SARS-CoV-2. A combination of IFN-a2b and the antioxidant taurine is widely used in the Russian Federation, and its antiviral activity has not been studied before. The aim of this study was to determine the antiviral activity of interferon drugs, in combination with taurine and without it. The study included cytotoxicity and antiviral activity assays of IFN-a2b preparations, when stored according to the instructions at 2-8°C, and after 1 month storage at the temperature of 20-26°C in a pre-opened state. The combination of IFN alpha-2b with taurine has a higher antiviral activity compared to IFN alpha-2b mono-preparation by more than 25% at a «low» and 85% at a «high» multiplicity of infection. Selectivity index for combinations of IFN-a2b (50,000 IU/dose) + taurine (1 mg/ml) and IFN-a2b (10,000 IU/ml) + taurine (0.8 mg/ml) was more than 600 units, whereas for the IFN-a2b (10,000 IU/ml) it was 200 units. Antiviral activity does not change after one month at room temperature. The combination of interferon with taurine at high concentrations was less toxic than interferon. The results obtained demonstrate practicability of interferon alpha-2b and taurine combination use for treatment and prevention of COVID-19.

Glycyrrhizin as a promising kryptonite against SARS-CoV-2: Clinical, experimental, and theoretical evidences.

COVID-19 is the most devastating disease in recent times affecting most people globally. The higher rate of transmissibility and mutations of SARS-CoV-2 along with the lack of potential therapeutics has made it a global crisis. Potential molecules from natural sources could be a fruitful remedy to combat COVID-19. This systematic review highlights the detailed therapeutic implication of naturally occurring glycyrrhizin and its related derivatives against COVID-19. Glycyrrhizin has already been established for blocking different biomolecular targets related to the SARS-CoV-2 replication cycle. In this article, several experimental and theoretical evidences of glycyrrhizin and related derivatives have been discussed in detail to evaluate their potential as a promising therapeutic strategy against COVID-19. Moreover, the implication of glycyrrhizin in traditional Chinese medicines for alleviating the symptoms of COVID-19 has been reviewed. The potential role of glycyrrhizin and related compounds in affecting various stages of the SARS-CoV-2 life cycle has also been discussed in detail. Derivatization of glycyrrhizin for designing potential lead compounds along with combination therapy with other anti-SARS-CoV-2 agents followed by extensive evaluation may assist in the formulation of novel anti-coronaviral therapy for better treatment to combat COVID-19.

A NOVEL CLASS of ANTIVIRAL COMPOUNDS with POTENT ACTIVITY AGAINST SARS-CoV-2

Background: The SARS-CoV-2 pandemic has sickened over 245 million people, and has killed more than 5 million worldwide. Recent data proves that vaccinations are highly effective in preventing Covid-19 disease, however antigenic drift and other functional mutations in the virus genome reduce the efficacy of vaccines, indicating that the development of antiviral treatments remain a crucial priority. We report potent antiviral activity against SARS-CoV-2 for a promising, novel class of nitrogen-based heterocyclic compounds. Methods: 232 compounds based on the same class of nitrogen-based hetereocyclic molecules were synthesized to final purity of greater than 99%. This library was screened for antiviral phenotypes in a cytopathic effect (CPE) assay using VeroE6 cells and the SARS-CoV-2 WA1 isolate. Based on the results of the WA1 CPE screen, 47 lead candidates were structurally analyzed, and this information was utilized to design 56 additional compounds. A second antiviral CPE-based screen was performed using these 103 candidates in VeroE6 cells with the SARS-CoV-2 delta variant. Antiviral assays studying SARS-CoV-1 (Urbani) and MERS-CoV were performed in Vero 76 cells utilizing a Neutral Red cytopathic effect assay. Results: Within the same class of structurally related small molecules, we tested an initial set of 232 compounds using a CPE-based assay with VeroE6 cells and the USA/WA1 SARS-CoV-2 isolate. Of the compounds tested, 124 demonstrated potency 10 to 540-times higher than a Remdesivir control tested in parallel. Importantly, we observed no detectable toxicity for the vast majority of these compounds when tested up to a concentration of 30 μ M. The lead candidate in this screen displayed an IC50 of 0.02 μ M and a selectivity index of >1,500. Based on structural analysis of an initial 47 lead candidates, we synthesized 56 new molecules, and tested all 103 in a CPE-based assay using the delta variant, also observing efficacy against this variant of concern. Examples of this same class of compounds also display antiviral activity against SARS-CoV-1 (Urbani) and MERS-CoV in cell-based assays. Conclusion: We have identified a novel class of antiviral compounds with potent activity against SARS-CoV-2. High potency against both the early WA1 isolate and the more recent delta variant, as well as efficacy against SARS-CoV-1 and MERS-CoV, suggest that this class of antiviral compounds has pan-Coronavirus antiviral activity.

Antiviral potential of garlic (Allium sativum) and its organosulfur compounds: A systematic update of pre-clinical and clinical data.

BACKGROUND: Garlic (Allium sativum L.) is a common herb consumed worldwide as functional food and traditional remedy for the prevention of infectious diseases since ancient time. Garlic and its active organosulfur compounds (OSCs) have been reported to alleviate a number of viral infections in pre-clinical and clinical investigations. However, so far no systematic review on its antiviral effects and the underlying molecular mechanisms exists. SCOPE AND APPROACH: The aim of this review is to systematically summarize pre-clinical and clinical investigations on antiviral effects of garlic and its OSCs as well as to further analyse recent findings on the mechanisms that underpin these antiviral actions. PubMed, Cochrane library, Google Scholar and Science Direct databases were searched and articles up to June 2020 were included in this review. KEY FINDINGS AND CONCLUSIONS: Pre-clinical data demonstrated that garlic and its OSCs have potential antiviral activity against different human, animal and plant pathogenic viruses through blocking viral entry into host cells, inhibiting viral RNA polymerase, reverse transcriptase, DNA synthesis and immediate-early gene 1(IEG1) transcription, as well as through downregulating the extracellular-signal-regulated kinase (ERK)/mitogen activated protein kinase (MAPK) signaling pathway. The alleviation of viral infection was also shown to link with immunomodulatory effects of garlic and its OSCs. Clinical studies further demonstrated a prophylactic effect of garlic in the prevention of widespread viral infections in humans through enhancing the immune response. This review highlights that garlic possesses significant antiviral activity and can be used prophylactically in the prevention of viral infections.

The Petasites hybridus CO2 Extract (Ze 339) Blocks SARS-CoV-2 Replication In Vitro.

The coronavirus disease 2019 (COVID-19), caused by a novel coronavirus (SARS-CoV-2), has spread worldwide, affecting over 250 million people and resulting in over five million deaths. Antivirals that are effective are still limited. The antiviral activities of the Petasites hybdridus CO2 extract Ze 339 were previously reported. Thus, to assess the anti-SARS-CoV-2 activity of Ze 339 as well as isopetasin and neopetasin as major active compounds, a CPE and plaque reduction assay in Vero E6 cells was used for viral output. Antiviral effects were tested using the original virus (Wuhan) and the Delta variant of SARS-CoV-2. The antiviral drug remdesivir was used as control. Pre-treatment with Ze 339 in SARS-CoV-2-infected Vero E6 cells with either virus variant significantly inhibited virus replication with IC50 values of 0.10 and 0.40 µg/mL, respectively. The IC50 values obtained for isopetasin ranged between 0.37 and 0.88 µM for both virus variants, and that of remdesivir ranged between 1.53 and 2.37 µM. In conclusion, Ze 339 as well as the petasins potently inhibited SARS-CoV-2 replication in vitro of the Wuhan and Delta variants. Since time is of essence in finding effective treatments, clinical studies will have to demonstrate if Ze339 can become a therapeutic option to treat SARS-CoV-2 infections.

Co-crystallization and structure determination: An effective direction for anti-SARS-CoV-2 drug discovery.

Safer and more-effective drugs are urgently needed to counter infections with the highly pathogenic SARS-CoV-2, cause of the COVID-19 pandemic. Identification of efficient inhibitors to treat and prevent SARS-CoV-2 infection is a predominant focus. Encouragingly, using X-ray crystal structures of therapeutically relevant drug targets (PLpro, Mpro, RdRp, and S glycoprotein) offers a valuable direction for anti-SARS-CoV-2 drug discovery and lead optimization through direct visualization of interactions. Computational analyses based primarily on MMPBSA calculations have also been proposed for assessing the binding stability of biomolecular structures involving the ligand and receptor. In this study, we focused on state-of-the-art X-ray co-crystal structures of the abovementioned targets complexed with newly identified small-molecule inhibitors (natural products, FDA-approved drugs, candidate drugs, and their analogues) with the assistance of computational analyses to support the precision design and screening of anti-SARS-CoV-2 drugs.

The potential of BEN815 as an anti-inflammatory, antiviral and antioxidant agent for the treatment of COVID-19.

Background: The corona virus disease 2019 (COVID-19) pandemic has highlighted the fact that there are few effective antiviral agents for treating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Although the very recent development of vaccines is an extremely important breakthrough, it remains unclear how long-lived such vaccines will be. The development of new agents therefore remains an important goal. Purpose: Given the multifaceted pathology of COVID-19, a combinatorial formulation may provide an effective treatment. BEN815, a natural nutraceutical composed of extracts from guava leaves (Psidium guajava), green tea leaves (Camellia sinensis), and rose petals (Rosa hybrida), had previously shown to have a therapeutic effect on allergic rhinitis. We investigated whether BEN815 possesses anti-inflammatory, antiviral and antioxidant activities, since the combination of these effects could be useful for the treatment of COVID-19. Study design: We examined the anti-inflammatory effects of BEN815 and its principal active components quercetin and epigallocatechin gallate (EGCG) in lipopolysaccharide (LPS)-induced RAW264.7 cells and in an LPS-challenged mouse model of endotoxemia. We also assessed the antioxidant activity, and antiviral effect of BEN815, quercetin, and EGCG in SARS-CoV-2-infected Vero cells. Methods: The principal active ingredients in BEN815 were determined and quantified using HPLC. Changes in the levels of LPS-induced pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α were measured by ELISA. Changes in the expression levels of cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) were analyzed using western blotting. Antioxidant assay was performed using DPPH and ABTS assay. SARS-CoV-2 replication was measured by immunofluorescence staining. Results: BEN815 significantly suppressed the induction of IL-6 and TNF-α as well as COX-2 and iNOS in LPS-induced RAW264.7 cells. In addition, BEN815 protected against LPS-challenged endotoxic shock in mice. Two major constituents of BEN815, quercetin and EGCG, reduced the induction of IL-6 and TNF-α as well as COX-2 and iNOS synthase in LPS-induced RAW264.7 cells. BEN815, quercetin, and EGCG were also found to have antioxidant effects. Importantly, BEN815 and EGCG could inhibit SARS-CoV-2 replications in Vero cells. Conclusion: BEN815 is an anti-inflammatory, antiviral, and antioxidant natural agent that can be used to prevent and improve inflammation-related diseases, COVID-19.