EGCG, a green tea polyphenol, inhibits human coronavirus replication in vitro

Biochem Biophys Res Commun. 2021 Apr 2;547:23-28. doi: 10.1016/j.bbrc.2021.02.016. Epub 2021 Feb 10.


COVID-19 pandemic results in record high deaths in many countries. Although a vaccine for SARS-CoV-2 is now available, effective antiviral drugs to treat coronavirus diseases are not available yet. Recently, EGCG, a green tea polyphenol, was reported to inhibit SARS-CoV-2 3CL-protease, however the effect of EGCG on coronavirus replication is unknown. In this report, human coronavirus HCoV-OC43 (beta coronavirus) and HCoV-229E (alpha coronavirus) were used to examine the effect of EGCG on coronavirus. EGCG treatment decreases 3CL-protease activity of HCoV-OC43 and HCoV-229E. Moreover, EGCG treatment decreased HCoV-OC43-induced cytotoxicity. Finally, we found that EGCG treatment decreased the levels of coronavirus RNA and protein in infected cell media. These results indicate that EGCG inhibits coronavirus replication.

Keywords: 3CL-protease; Coronavirus; EGCG; HCoV-229E; HCoV-OC43.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Line, Tumor
  • Coronavirus 229E, Human / drug effects*
  • Coronavirus 229E, Human / physiology
  • Coronavirus 3C Proteases / antagonists & inhibitors
  • Coronavirus OC43, Human / drug effects*
  • Coronavirus OC43, Human / physiology
  • Humans
  • Polyphenols / pharmacology*
  • SARS-CoV-2 / drug effects
  • SARS-CoV-2 / physiology
  • Tea / chemistry*
  • Virus Replication / drug effects*


  • Polyphenols
  • Tea
  • Coronavirus 3C Proteases