Figure 2. Costunolide enhanced doxorubicin to induce apoptosis in PC-3 and DU-145 cells.

PC-3 and DU-145 cells were treated with 20 μM costunolide, 200 nM doxorubicin, or both for 24 h. Costunolide enhanced doxorubicin to induce apoptosis in PC-3 (A) and DU-145 (B) cells detected by using annexin V-APC kit and PI staining. Bar charts showed quantitative data of average of 3 independent experiments in PC-3 and DU-145 cells. Western blots and quantitative analyses were performed to determine cleave caspase-9, cleave caspase-3 and PARP proteins expression in PC-3 (C) and DU-145 (D) cells after treatment. β-actin was used as a loading control. Results were presented as the mean ± SD of three independent experiments. ^*p < 0.05; ^#p < 0.05 compared with the control group.