Protective effect of a phenolic-rich fraction from Schisandra chinensis against H2O2-induced apoptosis in SH-SY5Y cells

We have investigated the neuroprotective effects of a phenolic-rich fraction (PRF) on the hydrogen peroxide (H(2)O(2))-induced apoptosis of cultured SH-SY5Y cells. The PRF was obtained from the 80% ethanol extract of the fruits of Schisandra chinensis by Sepabeads SP-850 column chromatography. Cell viability assays revealed that pretreating SH-SY5Y cells with PRF (10-200 mugmL(-1)) resulted in significant dose-dependent protection against H(2)O(2)-induced cell death. The protective effect of PRF against H(2)O(2)-induced apoptosis was assessed by flow cytometric analysis of DNA contents using propidium iodide (PI) staining. Pre-incubation of cells with PRF at different concentrations for 24 h partially protected apoptosis by H(2)O(2) (150 muM). Moreover, cells treated with PRF reduced H(2)O(2)-induced caspase-3 activation and poly (ADP-ribose) polymerase cleavage and exerted an apparent suppressive effect on oxidative stress induced by reactive oxygen species (ROS). We concluded that PRF may be useful in the treatment and prevention of neurodegenerative diseases associated with elevated ROS levels.