Figure 4.

Emodin inhibits SADS-CoV infection at multiple steps of the virus life cycle. (A) SADS-CoV-infected IPI-FX cells were co-incubated with Emodin (12.5 μg/ml) or 0.1% DMSO at different stages of the viral replication cycle (M1–M7). Cell lysates were collected at 24 h after infection. (B) Real-time PCR was used to examine the mRNA expression of N and GAPDH using specific primers. The expression levels of mRNA were calculated in relation to the expression level of GAPDH. (C) The expression of N and GAPDH proteins was detected by Western blot using anti-SADS-CoV N polyclonal antibody and anti-GAPDH monoclonal antibody. (D) The viral titers were measured by the TCID₅₀ assay. Data are representative of three independent experiments (mean ± SD). n = 3. *p < 0.05, **p < 0.01, ***p < 0.001.