Figure 4.

EGCG, TSA, and TFDG inactivated SARS-CoV-2, but did not render cells resistant to intact virus. (a,b) Virus was treated with each compound at the indicated concentrations for 1 min, and the mixture was added to VeroE6/TMPRSS2 cells at MOI = 3 for 1 h. After removal of the supernatant, cells were cultured in fresh MS for 30 h, followed by cell viability evaluation as described in the Materials and Methods section. (c,d) Cells were pretreated with the indicated concentrations of the compounds for 10 min, followed by a removal of the supernatant, wash with PBS, and an addition of virus suspension (MOI = 5). One hour later, supernatant was replaced by fresh MS, and cells were culture for 30 h until cell viability was evaluated. Values are means ± S.D. (n = 3). * p < 0.05, ** p < 0.01 and *** p < 0.001 between groups by Student’s t test.