Neochamaejasmin A extracted from Stellera chamaejasme L. induces apoptosis involving mitochondrial dysfunction and oxidative stress in Sf9 cells

Abstract

To explore the toxicity mechanisms of neochamaejasmin A (NCA), extracted from Stellera chamaejasme L., we first evaluated its cytotoxicity on the Spodoptera frugiperda (Sf9) cell line. The results confirmed that NCA inhibited Sf9 cell survival in both a dose- and time-dependent manner. Then, intracellular biochemical assays showed that NCA induced apoptosis in Sf9 cells. Evidence of apoptosis was confirmed by morphological changes and the activation of caspases-3/9. We also observed that NCA induced apoptosis via mitochondrial-dependent intrinsic apoptotic pathway by upregulating cytochrome c and proapoptotic protein (Bax) and downregulating the mitochondrial membrane potential (MMP) and antiapoptotic protein (Bcl-2). Moreover, we found a dose-dependent increase in reactive oxygen species (ROS), accumulation of lipid peroxidation product and an inactivation of the antioxidant enzymes in treated cells. Additionally, the cleavage of PARP and G2/M arrest were also detected in Sf9 cells exposed to NCA. These findings provide critical information that NCA effectively induced apoptosis in Sf9 cells through mitochondrial pathways.