In Vitro study of 56 polyphenols showing that curcumin has high binding affinity to the RBD of the SARS-CoV-2 spike protein, inhibits ACE2 at non-toxic concentrations, and decreases activity of TMPRSS2. Promising results were also seen for brazilin and theaflavin-3,3’-digallate.
Goc et al., 6/17/2021, peer-reviewed, 4 authors.
In Vitro studies are an important part of preclinical research, however results may be very different in vivo.