Theaflavins, polyphenols of black tea, inhibit entry of hepatitis C virus in cell culture

Abstract

The treatment of hepatitis C virus (HCV) infection by combination of direct acting antivirals (DAA), with different mode of action, has made substantial progress in the past few years. However, appearance of resistance and high cost of the therapy is still an obstacle in the achievement of the therapy, more specifically in developing countries. In this context, search for affordable antivirals with new mechanisms of action is still needed. Tea, after water, is the most popular drink worldwide. Polyphenols extracted from green tea have already shown anti-HCV activity as entry inhibitors. Here, three different theaflavins, theaflavin (TF1), theaflavin-3’-monogallate (TF2), and theaflavin-3-3’-digallate (TF3), which are major polyphenols from black tea, were tested against HCV in cell culture. The results showed that all theaflavins inhibit HCV infection in a dose-dependent manner in an early step of infection. Results obtained with HCV pseudotyped virions confirmed their activity on HCV entry and demonstrated their pan-genotypic action. No effect on HCV replication was observed by using HCV replicon. Investigation on the mechanism of action of black tea theaflavins showed that they act directly on the virus particle and are able to inhibit cell-to-cell spread. Combination study with inhibitors most widely used in anti-HCV treatment regimen demonstrated that TF3 exerts additive effect. In conclusion, theaflavins, that are present in high quantity in black tea, are new inhibitors of HCV entry and hold promise for developing in therapeutic arsenal for HCV infection.

The potential chemical structure of anti‐SARS‐CoV‐2 RNA‐dependent RNA polymerase

“…Theaflavin, a polyphenolic compound in black tea, is thought to be responsible for the medicinal value of black tea. Theaflavin and theaflavin gallate derivatives have shown broad‐spectrum antiviral activity against several viruses, including influenza A and B viruses and hepatitis C virus 15,16 …”

Plant-derived natural polyphenols as potential antiviral drugs against SARS-CoV-2viaRNA‐dependent RNA polymerase (RdRp) inhibition: anin-silicoanalysis

“…Many reports suggest polyphenols have low systemic toxicity, and they are highly beneficial for human health (Bhardwaj et al., 2020 ; Cory et al., 2018 ). TF1 and its gallate derivatives, collectively known as black tea polyphenols, previously have shown to exert antiviral activity against many viruses such as hepatitis virus and influenza A and B viruses (Chowdhury et al., 2018 ). Hesperidin is also known to possess antiviral activity by altering the immune system mainly via regulating interferons in the influenza A virus (Randall & Goodbourn, 2008 ).…”

Nutrigenomic Effects of Long-Term Grape Pomace Supplementation in Dairy Cows

“…Some dietary polyphenols (e.g., quercetin, resveratrol, rutin) show a certain efficacy against leishmaniosis [90], and giardiasis [91]; furthermore, resveratrol itself has been suggested as a potential restorative agent against toxoplasmosis brain disorders [92] and Schistosoma mansoni infections [93]. As far as the effects on viruses, human and animal evidence suggest polyphenolic compounds (e.g., resveratrol, tea polyphenols) possess potential preventive and therapeutic effects, and might be used as adjuvant therapy for the management of viral infection, e.g., influenza, herpes simplex, pseudorabies, hepatitis C, porcine reproductive and respiratory syndrome, and even Ebola [88,[94][95][96][97].…”