Figure 2.

Emodin from Ae inhibits SADS-CoV replication in vitro. (A) Chemical structures of Aloin, Emodin, and Quercetin. (B) The cytotoxicity of Aloin, Emodin, and Quercetin in Vero and IPI-FX cells. Vero and IPI-FX cells were co-incubated with various concentrations of Aloin (25–400 μg/ml), Emodin (6.25–100 μg/ml), and Quercetin (1.5625–400 μg/ml) or 0.1% DMSO for 24 h and 48 h prior to the CCK-8 assay. (C) Vero and IPI-FX cells were pre-incubated with Aloin, Emodin, and Quercetin, or 0.1% DMSO at a safe concentration for 1 h, followed by infection with SADS-CoV at an MOI of 0.1. After 1.5 h, the cells were re-treated with Aloin, Emodin, and Quercetin or the normal medium. At 24 h post-inoculation, the expression levels of N and GAPDH proteins in the cell lysates were detected by Western blot using anti-SADS-CoV N polyclonal antibody and anti-GAPDH monoclonal antibody. (D) The relative quantity of SADS-CoV N protein described in (C). (E) At indicated time points (12 h, 24 h, and 48 h), the viral titers in the cell lysates were determined by the TCID₅₀ assay. Results are representative of three independent experiments (mean ± SD). n = 8 or 3. **p < 0.01, ***p < 0.001.