Effects of dracorhodin perchlorate (DP) on the expression of major cell cycle and apoptotic regulators determined by western blot analysis. Gel-Pro Analyzer software was employed to extract quantitative data. (A) Protein expression levels of p53 and pRb determined by western blot analysis. (B) Protein expression levels of Bax, Bcl-2, Cas-3, PARP and AIF determined by western blot analysis. Data are expressed as the mean ± standard deviation of three independent experiments. **P<0.05 vs. control. pRb, phosphorylated retinoblastoma; Bcl-2, B-cell lymphoma-2; Bax, Bcl-2-associated X protein; Cas-3, pro-caspase-3; PARP, poly(ADP-ribose) polymerase; AIF, apoptosis-inducing factor.