FIG 1.

PKC inhibitors reduce the replication of SARS-CoV-2 in BHK-21 cells. (A and B) Luciferase activity of the replicon system. BHK-21 cells were pretreated with DMSO, remdesivir (A), or PKC inhibitors (Go 6983, bisindolylmaleimide I, enzastaurin, or sotrastaurin) (B) for 1 h, followed by replicon RNA transfection. The luciferase activities were determined at 6 or 24 h posttransfection. (C to F) IC₅₀ and CC₅₀ values of Go 6983 (C), bisindolylmaleimide I (D), enzastaurin (E), and sotrastaurin (F) in BHK-21 cells. IC₅₀ and CC₅₀ values are indicated above the curves. The cytotoxic effects of each drug at the indicated concentrations were determined by a CCK8 cell viability assay at 24 h. CC₅₀ values were calculated using Prism software. Data are presented as means ± standard deviations (SD) from three experiments; P values were calculated by unpaired, two-tailed Student’s t tests or ANOVA with Dunnett’s multiple-comparison test (***, P < 0.001; ****, P < 0.0001; NS, not significant).