Figure 2.

Antiviral activities of pimprinine, pimprinethine, WS-30581 A and WS-30581 B against EV71 in a dose-dependent manner in RD cells. (A) The inhibition of virus-induced CPE. RD cells were infected with 100 TCID₅₀ of EV71 mixed with serial dilutions of tested compounds for 1 h at 37°C, the inocula were aspirated and the cells were incubated with DMEM/tested compounds at 37°C, 5% CO₂ for 48 h, the antiviral effects were observed in terms of cellular morphology. (B) The inhibition of progeny virus yield. RD cells were infected with 100 TCID₅₀ of EV71 in the absence or presence of tested compounds, the culture media and cell lysates were collected for virus titration at 10 h pi. The viral titers were presented as Log10 TCID₅₀/mL. (C) Analysis of the dependence of the EC50s on virus titers. RD cells were infected with various TCID₅₀ of EV71, the tested compounds were added as described in (A), cell viability was determined at 48 h pi and the EC50 were calculated. The x-axis is in a base 10 logarithmic scale. Each value is the mean of triplicate assays ± standard deviation (SD).