Abstract
Potential effects of teas and their constituents on SARS-CoV-2 infection were studied in vitro. Infectivity of SARS-CoV-2 was significantly reduced by a treatment with green tea, roasted green tea or oolong tea. Most remarkably, exposure to black tea for 1 min decreased virus titer to an undetectable level (less than 1/1,000 of untreated control). An addition of (-) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while theasinensin A (TSA) and galloylated theaflavins including theaflavin 3, 3’-di-gallate (TFDG) had more remarkable anti-viral activities. Virus treated with TSA at 500 μM or TFDG at 100 μM showed less than 1/10,000 infectivity compared with untreated virus. TSA and TFDG significantly inhibited interaction between recombinant ACE2 and RGD of S protein. These results strongly suggest that EGCG, and more remarkably TSA and galloylated theaflavins, inactivate the novel coronavirus.
Competing Interest Statement
This study was partially funded by ITO EN, ltd, Tokyo, Japan. The company also provided tea samples, sample preparations and discussion with authors, but did not involve in the design of the study, collection and analyses of data, interpretation of results, preparation of the manuscript, or the decision to publish the results.
