Induction of apoptosis by Myagropsis myagroides extracts is associated with a caspase dependent pathway and reactive oxygen species generation in human cancer cells

The purpose of this study was to elucidate the mechanisms underlying apoptosis induced by an ethanol extracts from Myagropsis myagroides (ME) in HeLa, U937, and PC-3 cells. ME treatment for 24 h significantly inhibited cell viability in a dose-dependent manner, and induced apoptosis. Moreover, ME treatment triggered the cleavage of caspase-8, -9, -3, and poly(ADP-ribose) polymerase (PARP). A general caspase inhibitor (z-VAD-fmk) inhibited ME-induced activation of caspase-3, PARP cleavage, and cell death. ME treatment also triggered the release of cytochrome c from the mitochondria to the cytosol and stimulated the cleavage of Bid, up-regulation of Bax, and down-regulation of Bcl-2. Furthermore, ME treatment caused reactive oxygen species (ROS) generation. An antioxidant N-acetylcysteine (NAC) blocked MEinduced activation of caspase-3, PARP cleavage, and cell death. Overall, these results suggest that ME-induced apoptosis is mediated by a caspase dependent pathway and ROS generation in HeLa, U937, and PC-3 cells.