Activation of caspase-3, -8 and -9 after ginsenosides treatment on HK-1 cells. HK-1 cells were treated with ginsenosides (A) 20(S)-Rh2 (15 μM), (B) CK (15 μM), (C) PD (10 μM) and (D) PPD (10 μM) in 1% FBS supplemented RPMI 1640 medium. Cells lysates were harvested at indicated time points for Western blot analysis using antibodies against both pro and active forms of caspase-3, -8 and -9. The expression of the pro and active forms was indicated by solid and hollow arrows, respectively. β-actin was used as a protein loading control.