Fig. 4. Cytotoxicity and anti-PRRSV activity of compounds 9 and 12 in PAM cells. (A) Cellular toxicity of 9 and 12 was examined in PAMs at 48 hpi using MTT assay. (B) and (C) PAMs grown in 24-well plates were infected with NADC30-like PRRSV (0.5 MOI) for 2 h at 37 °C and then treated with various concentrations of 9 or 12. 24 or 48 h later, the samples were submitted to viral titer determination using the end point dilution assay and expressed as log10 TCID50/1 mL. *P < 0.05, **P < 0.01, and ***P < 0.001 compared to that of the DMSO control.
