Decursin from Angelica gigas Nakai induces apoptosis in RC-58T/h/SA#4 primary human prostate cancer cells via a mitochondria-related caspase pathway

Decursin is a major biological active component of Angelica gigas Nakai and is known to induce apoptosis of metastatic prostatic cancer cells. However, the apoptotic mechanism of decursin using primary malignant tumor (RC-58T/h/SA#4)-derived human prostate cells is not known. In the present study, we show that treatment of prostate cancer cells with decursin inhibited cell proliferation in a dose-dependent manner. Decursin also induced apoptosis in RC-58T/h/SA#4 cells, as determined by flow cytometry, Hoechst 33258 staining, and DNA fragmentation. Decursin caused activation of caspases-8, -9, and -3 and promoted the apoptotic action of caspase-8-mediated Bid cleavage. Decursin increased the protein levels of Bax and cytosolic cytochrome c as well as cleavage of PARP while decreasing the protein levels of Bcl-2. Furthermore, the caspase-independent mitochondrial apoptosis factor, apoptosis-inducing factor (AIF), was upregulated by treatment with decursin. Taken together, these findings indicate that decursin inhibited the proliferation of RC-58T/h/SA#4 cells through induction of apoptosis, which is mediated by both caspase-dependent and -independent apoptotic pathways.