Fig. 2.

Anti- SADS-CoV activity of quercetin on IPI-FX. (A) IPI-FX was treated with different concentrations of quercetin for 24 h, and cell viability was measured by CCK-8 assay. (B) Infection with SADS-CoV (0.1 MOI) in the presence of different concentrations of quercetin was replaced with fresh medium containing different concentrations of quercetin supplemented with 3‰ trypsin after 1 h, and the relative SADS-CoV N mRNA levels were determined by RT-qPCR at 24 h, with DMSO as a treatment control. Results are from one of three independent experiments (n = 3), and asterisks in the graphs indicate significant differences (*P < 0.05; **P < 0.01; ***P < 0.001; ns: not significant). (C) Cell lysates were collected at 24 h for protein blot identification. (D) SADS-CoV N protein content was detected by IFA under fluorescence microscope, SADS-CoV N protein was shown in green color and nuclei in blue color. (E) Release of quercetin-treated SADS-CoV into cell supernatants in daughter virus titers