Figure 4.

A-macB enhances intracellular ROS production and induced p38/caspase 9 mediated apoptotic pathway. (A and B) A-macB treatment markedly increased ROS levels in A549 and H1299 cells. The antioxidant N-acetylcysteine (NAC, a precursor of glutathione, 10 mM) effectively prevented A-macB-induced ROS generation. (C and D) The population of H1299 and A549 cells undergoing apoptosis increased significantly in response to increasing ROS levels. NAC pretreatment prevented H1299 and A549 apoptosis. (E) Western blot analysis showed that NAC pretreatment protected cells from DNA damage and inhibited the p38 MAPK signaling pathway, thus suppressing the caspase 9-caspase 3-PARP signaling pathway. Data are presented as the mean ± SEM (*p < 0.05, **p < 0.01, ***p < 0.001).