Emodin increased the expression of Apaf-1, Cytochrome c, Fas, FasL, and FADD but decreased the expression of Pro-caspase-9, Pro-caspase-8, and Pro-caspase-3 in HeLa cells. HeLa cells were treated with Emodin (0, 20, 40 and 80 μM) for 48 h and the expression of proteins in treated cells was determined by Western blot analysis. (a), Emodin increased the expression of Apaf-1, Cytochrome c. (b), Emodin increased the expression of Fas, FasL, and FADD. (c), Emodin decreased the expression of Pro-caspase-8, Pro-caspase-9, and Pro-caspase-3. Data are reported as the means±SEM of at least three experiments. *P<0.05 versus control group (0 μM) (two-way ANOVA followed by the Tukey post hoc test).