Figure 5

Antiviral activities of phenazine-1-carboxylic acid (PCA) against ASFV. A The chemical structure of PCA. B Half-cytotoxic concentration (CC₅₀) of PCA in PAMs. The PAMs were exposed to varying concentrations of PCA, and cell viability was assessed using the CellTiter-Glo kit at 48 hours post-treatment. The CC₅₀ was calculated using dose–response curves on GraphPad Prism. C The half-maximal inhibitory concentration (IC₅₀) of PCA on ASFV. PAMs were infected with rASFV-Gluc/EGFP (MOI = 0.2) and treated with a specified concentration of PCA; luciferase activities were measured at 36 hours post-infection (hpi) to evaluate the IC₅₀, which was calculated using nonlinear regression analysis of dose‒response curves on GraphPad Prism. D and E Anti-ASFV activities of PCA by EGFP expression assay. PAMs were infected with rASFV-Gluc/EGFP (MOI = 0.2) while being treated with PCA (0, 5, 10, or 25 μM), and EGFP expression was observed at 36 hpi, with representative fluorescence images captured (D), and the number of EGFP-positive cells per field of view was measured using the ImageJ software (E). Scale bars = 400 μm. F Inhibition of rASFV-Gluc/EGFP replication by PCA. ASFV genomic DNA was extracted from the PAMs infected with rASFV-Gluc/EGFP and then treated with a specified concentration of PCA (0, 5, 10, or 25 μM), after which the ASFV genome copies was measured by qPCR. G The antiviral effects of PCA on rASFV-Gluc/EGFP. PAMs were infected with rASFV-Gluc/EGFP (MOI = 0.2) and treated with a specified concentration of PCA (0, 5, 10, or 25 μM). The viral titres were determined by a hemadsorption (HAD) assay at 48 hpi. H Western blotting analysis of PCA-mediated inhibition of ASFV-WT. The protein expression levels of the p72 and A137R in the ASFV-WT-infected PAMs treated with different concentrations of PCA (0, 5, 10, or 25 μM) were analysed by western blotting. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.