Figure 9.

Antiviral activity and cytotoxicity of robinetin, piceatannol, rosmarinic acid, scutellarein, EGCG, oridonin in Calu-3 cells. Calu-3 cells were incubated with 10-fold serial dilutions (10−0.001 or 1-0.0001 μM) of each inhibitor or DMSO (solvent control) for 1 h followed by infection with SARS-CoV-2 at a multiplicity of infection (MOI) of 0.01. After virus inoculation, cells were further incubated with the respective inhibitors for 24 h. Supernatants were harvested, and viral titers were determined by titration on Vero E6 cells. For normalization, viral titers of DMSO-treated cells were set as 0% inhibition. Means ± SDs from three biological replicates are presented.