International Journal of Neurorehabilitation

Polygonum multiflorum extracts protect the SH-SY5Y cells against the oxidative stress injury induced by MPP+

Abstract

Yadong Zhu, Jing Zhu, Xu Yang, Yongming Caib, Wei-Jian Beia and Jiao Guo

Objective: To investigate the protective effect of Polygonum multiflorum extracts (EPM) on SH-SY5Y cells treated with MPP+. Methods: SH-SY5Y cells were first exposed to various doses of EPM, and then treated with MPP+. The cell viability was detected with MTT assay, cell morphology was observed with microscope by Hoechst33258 staining, the level of glutathione (GSH), Malondialdehyde (MDA) and the activity of Lactate dehydrogenase (LDH) were measured with UV spectrophotometer. Reactive oxygen species (ROS) and the mitochondrial membrane potential were observed with fluorescence microscope. The expression of p-JNK and Caspase 3 was analyzed by Western Blot. Results: After 0.5 mmol/L MPP+ treatment for 48 h, the viability of SH-SY5Y cells was decreased to 44.7% (VS. control group), the shrunk cell body and nuclear condensation were observed. Compared with control group, the activity of lactate dehydrogenase (LDH), the level of malondialdehyde (MDA) and reactive oxygen species (ROS) and the expression of p-JNK and Caspase 3 were increased significantly in MPP+ treated SH-SY5Y cells, whereas the level of GSH and the mitochondrial membrane potential was reduced significantly in MPP+ treated group. However, pretreatment with EPM (at the concentration of 5, 25 and 100 mg/L) 4 h prior to being exposed to MPP+ rescued the cell viability of SH-SY5Y cells, and restored the cell morphological features in a dose-dependent manner. The increasement of lactate dehydrogenase (LDH), malondialdehyde (MDA) and reactive oxygen species (ROS) and the expression of p-JNK and Caspase 3 induced by MPP+ were also inhibited significantly by pretreatment with EPM. Exposure to EPM also blocked the reduction of the GSH level and the mitochondrial membrane potential induced by MPP+ in SH-SY5Y cells. Conclusion: Our results suggested that the EPM was able to protect the SH-SY5Y cells against the damage induced by MPP+, with the mechanism involved in resisting the oxidative stress.