Curculigoside reduces the expression of cytochrome c, APAF-1, caspase-9 and caspase-3 at the gene and protein levels in vitro. (A) The mRNA expression of cytochrome c, APAF-1, caspase-9 and caspase-3 was determined by RT-qPCR. (B) The protein expression of cytochrome c, APAF-1, cleaved caspase-9 and cleaved caspase-3 was evaluated by western blot analysis. **P<0.05 vs. the control group, *P<0.05 vs. the H/R group, #P<0.05 vs. the curculigoside-treated group. APAF-1, apoptotic protease activating factor-1; H/R, hypoxia/re-oxygenation; Cur, curculigoside; ATR, atractyloside.