Significant Inactivation of SARS-CoV-2 In Vitro by a Green Tea Catechin, a Catechin-Derivative, and Black Tea Galloylated Theaflavins

Potential effects of tea and its constituents on SARS-CoV-2 infection were assessed in vitro. Infectivity of SARS-CoV-2 was decreased to 1/100 to undetectable levels after a treatment with black tea, green tea, roasted green tea, or oolong tea for 1 min. An addition of (-) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while the same concentration of theasinensin A (TSA) and galloylated theaflavins including theaflavin 3,3 '-di-O-gallate (TFDG) had more remarkable anti-viral activities. EGCG, TSA, and TFDG at 1 mM, 40 mu M, and 60 mu M, respectively, which are comparable to the concentrations of these compounds in tea beverages, significantly reduced infectivity of the virus, viral RNA replication in cells, and secondary virus production from the cells. EGCG, TSA, and TFDG significantly inhibited interaction between recombinant ACE2 and RBD of S protein. These results suggest potential usefulness of tea in prevention of person-to-person transmission of the novel coronavirus.

Automated summary

This study evaluated the potential effects of tea and its constituents on SARS-CoV-2 infection in vitro. The results showed that black tea, green tea, roasted green tea, and oolong tea significantly reduced the infectivity of SARS-CoV-2, while compounds like EGCG, TSA, and TFDG had remarkable anti-viral activities at concentrations comparable to those found in tea beverages. These findings suggest the potential usefulness of tea in preventing person-to-person transmission of the novel coronavirus.