Fig. 2.

Inhibitory effects of cordycepin on PGE₂ production and expression of COX-2 and EPs in LPS-stimulated HCT-116 cells. Cells were pre-treated with 50 μg/ml of cordycepin for 1 h prior to incubation with LPS for 48 h. Total RNA (A; upper panel) and proteins (A; lower panel) were prepared and used for the RT-PCR analysis of COX-2 gene expression with GAPDH as an internal control. Actin was used as an internal control. (B) The culture supernatants were isolated, and the amount of PGE₂ production was determined. The data are expressed as the mean ± SD of three independent experiments. **P < 0.01 compared to LPS alone. (C) Total RNA was prepared and used for RT-PCR analysis of EP1-4 gene expression. (D) The data represent the EP1-4 mRNA levels in the LPS-treated cultures compared with control cultures from three independent experiments (**P < 0.01, ***P < 0.001).