TCRV inhibits PEDV infection through the regulation of caspase-3. (A) Western blotting analysis of PEDV N, cleaved caspase-3, and caspase-3 proteins in PEDV-infected Vero cells treated with 85 µM TCRV and 50 µM Z-DEVD-FMK at 24 hpi. Results were presented as the ratio of band intensities of the target protein to β-actin. (B) PEDV-infected cells were treated with 85 µM TCRV and 50 µM Z-DEVD-FMK at 24 hpi. Apoptosis was analyzed using Annexin V-PE/7AAD staining, and the apoptotic cells were explored using flow cytometry. The Annexin V-positive cells were considered apoptotic cells. (C) Determination of the cytotoxicity of Z-DEVD-FMK (30 µM, 40 µM, 50 µM, 60 µM, and 70 µM) by the CCK-8 assay. (D) Western blotting analysis of PEDV N, p-p53, and p53 proteins in PEDV-infected Vero cells treated with the indicated concentrations of TCRV and PTF-α (20 µM) at 24 hpi. Results were presented as the ratio of band intensities of the target protein to β-actin. (E) Determination of the cytotoxicity of PTF-α (5 µM, 10 µM, 20 µM, 30 µM, and 40 µM) by the CCK-8 assay. Data from three independent experiments and error bars are presented as the mean ± SEM. *** p < 0.001.