Protective effects of Paeonia lactiflora pall on hydrogen peroxide-induced apoptosis in PC12 cells

This study was conducted to examine the antioxidative and neuroprotective effects of Paeonia lactiflora pall (PLE). Total phenolic content of PLE was 89.65mg of gallic acid equivalent per gram of PLE. IC50 values for reducing power, hydrogen peroxide scavenging activity, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were 297.57, 3.33, and 32.74 mu g, respectively. The protective effect of PLE against H2O2-induced oxidative damage to PC12 cells was investigated by an 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) reduction assay and lactate dehydrogenase (LDH) release assay. After 2h of cell exposure to 0.5mm H2O2, a marked reduction in cell survival was observed. However, this reduction was significantly prevented by 10-100 mu g/ml of PLE. H2O2 also induced severe apoptosis of the PC12 cells, which was indicated by a flow cytometric analysis. Interestingly, the H2O2-stressed PC12 cells that had been incubated with PLE had greatly suppressed apoptosis. The results suggest that PLE could be a candidate for a new antioxidant against neuronal diseases.