We found that treatment with luteolin (20, 30, 40 μmol/L) led to the activation of caspase-3 and subsequently to the cleavage of PARP from its intact form (116 kD) to its cleaved form (89 kD) markedly in PC-3 cells (Fig. 7B), Taken together, these results suggest that luteolin induces apoptosis in prostate cancer cells through a caspase-3-dependent pathway. Here, CASP3 is linked to prostate cancer.