Fig. 1.

Anti-proliferative and apoptotic effect of apigenin on human prostate cancer cells. a Effect of apigenin on protein expression of cleaved caspase 3/9 and PARP cleavage. The cells were treated with 20 μM apigenin for specified times and Western blotting was performed. Time-dependent increase in protein expression of cleaved caspase 3/9 and PARP cleavage was observed in both cell lines after apigenin treatment. β-actin was used as loading control. Numeric values represent the protein level normalized to the loading control (β-actin). b Effect of caspase inhibitor treatment on apigenin-mediated cell viability in prostate cancer cells. The cells were pretreated with 0.1 % DMSO, pan caspase inhibitor (z-VAD-fmk), caspase 9 inhibitor (z-LEHD-fmk) and caspase 3 inhibitor (z-DEVD-fmk) at 150 μM for 1 h followed by 20 μM apigenin treatment for 24 h. Cell viability was measured by MTT assay. The experiment was repeated thrice with similar results. Bars represent mean ± SE, **P < 0.001 versus control. Details are described in “Materials and methods” section