[Protective Effect of Total Saponins of Panax japonicus Against H2O2-Induced Oxidative Stress Damage].

OBJECTIVE

To investigate the protective effects of total saponins of Panax japonicus (TSPJ) on H2O2-induced oxidative stress damage in SH-SY5Y cells, and to explore the underlying mechanism.

METHODS

SH-SY5Y cells were incubated with 600 μmol/L H2O2 for 12 h, then treated with various concentrations of TSPJ (0.1, 1, 5 and 20 μg/mL) for 12 h,and then incubated with 600 μmol/ L H2O2 for 12 h. Cell viability was detected by MTT assay. Superoxide dicmutase (SOD) activities and malondialdehyde( MDA) contents were measured by biochemical assay kits. Protein levels of Nrf2,p-ERK, and p-P38 were detected by Western blotting. Levels of NQO1 and GCLC mRNA expression were determined by real-time PCR.

RESULTS

Compared with control group, H2O2 stimulated the decrease of cell viability and SOD activities as well as the increase of MDA contents, which were reversed by TSPJ treatment. Furthermore, TSPJ treatment up-regulated not only the decreased protein expressions of Nrf2 and p-ERK but also the decreased mRNA expression of NQO1 and GCLC.

CONCLUSION

TSPJ can protect SH-SY5Y cells from H2O2-induced oxidative stress damage. The mechanism may be related to up-regulating the phosphorylation of ERK thereby promoting the Nrf2 nuclear translocation and increasing the mRNA expression of antioxidant genes such as NQO1 and GCLC.