Fig. 2
From: Inhibition of enterovirus 71 replication and viral 3C protease by quercetin
Analysis of effective stage. a The design of action mode of quercetin against EV71. b The antiviral effects were detected by measuring cell viability after 48 h of infection when cells were treated with quercetin before, simultaneously or after EV71 (100 TCID50) inoculation. c Analysis of the effect on EV71 adsorption. Mock- or quercetin-treated EV71 was inoculated onto RD cells and adsorbed for 2 h, the infected cells were harvested and then subjected to virus titrations using the TCID50 method. d Time-of-addition assay. 50 μM quercetin was added to RD cells at different time periods after EV71 infection. At 12 h pi, the progeny virus yield was determined by the TCID50 assay. (− 2–0 h: viral infection period; 0–12 h: the period for virus proliferation in the cells). VC, virus control