FIGURE 2.

Time-of-addition experiment investigating the viral stage at which quercetin is effective. LFBK cells were treated with 625 μM quercetin 2 h prior to foot-and-mouth disease virus (FMDV) infection (Pre-2 h), at the time of infection (Co-0 h), at 2 h (Post-2 h), or 4 h (Post-4 h) post-infection; cells were infected at 0.001 MOI for 2 h. In each step, cells were washed twice using Dulbecco’s modified Eagle’s medium (DMEM). The supernatant was collected 24 h post-infection, and virus titration was performed. Error bars indicate standard deviations from the mean. Unpaired t-tests were performed to identify significant differences. **P < 0.01, ***P < 0.005, ns, not significant.