Reactive oxygen species-mitochondria pathway involved in LYG-202-induced apoptosis in human hepatocellular carcinoma HepG2 cells

Previously, we demonstrated that LYG-202, a newly synthesized flavonoid with a piperazine substitution, exhibited obvious antitumor activity in vivo and in vitro. The exact mechanism of this new compound remains unclear. In the present study, we examined the effects of LYG-202 on reactive oxygen species (ROS) production and the downstream signaling pathway in the apoptosis of human hepatocellular carcinoma HepG2 cells. Pretreatment with NAC (N-acetylcysteine), a ROS production inhibitor, partly inhibited the apoptosis induced by LYG-202 via blocking the ROS generation. Further data revealed that LYG-202 induced ROS accumulation followed by a decrease in mitochondrial membrane potential (MMP), release of cytochrome c (Cyt c) and apoptosis-inducing factor (AIF) to cytosol, which induced apoptosis of the cells. Moreover, the mitogen-activated protein kinases (MAPK), the downstream effect of ROS accumulation including c-Jun N-terminal kinase (JNK) and p38 MAPK, could be activated by LYG-202. Taken together, the generation of ROS might play an important role in LYG-202-induced mitochondrial apoptosis pathway, which provided further support for LYG-202 as a novel anticancer therapeutic candidate.