[Protective effects and underlying mechanisms of Panax notoginseng saponins against SH-SY5Y cell apoptosis induced by 6-hydroxydopamine].

The aim of this study is to investigate the protective effects of Panax notoginseng saponins (PNS) against 6-hydroxydopamine(6-OHDA)-induced apoptosis in SH-SY5Y cells and the possible underlying mechanisms. Cell viability was examined by MTT assay. The levels of lactate dehydrogenase(LDH), reactive oxygen species (ROS), malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase(GSH-Px) were measured using the respective assay kits. Apoptosis was measured by TUNEL kit, JC-1 and ROS was measured by staining with fluorescent dyes. The activation of caspase-3 was measured with the caspase-3 assay kit. The expression of nuclear protein Nrf2 and HO-1 were determined by Western blot. PNS had significant protective effects against 6-OHDA-induced apoptosis in SH-SY5Y cells in a time- and dose-dependent manner. PNS could attenuate 6-OHDA-induced suppression of SOD, GAT, GSH-Px (P < 0.01). PNS reduced the level of LDH, decreased the levels of ROS, MDA and increased cell viability and the mitochondrial membrane potential (P < 0.01). PNS also inhibited DNA fragmentation, mitochondrial response and the activation of caspase-3 (P < 0.01). Moreover, PNS pretreatment increased the expression of the nuclear Nrf2 and up-regulate HO-1. The protective effects of PNS could be inhibited by HO-1 inhibitor SnPP. In conclusion, PNS has significant protective effects against 6-OHDA- induced apoptosis in SH-SY5Y cells. The possible mechanisms of PNS are due to PNS-mediated activation of Nrf2, up-regulation of HO-1 and inhibition of oxidative stress.