Neuroprotective effects of Hypericum perforatum on trauma induced by hydrogen peroxide in PC12 cells.

The standard extracts of Hypericum perforatum L. (SEHP), a well-known medicinal plant, are used for the treatment of depression, exhibited upgrading and significant protective effects on the trauma of PC12 cells induced by 200 microM H2O2 in a dose-dependent manner within 24-hour treatment. Cell viability was assessed by the MTT method, and in situ cellular hydrogen peroxide (H2O2)-induced oxidative stress was examined by measurement of reactive oxygen species (ROS) formation using CDCFH procedures. Intra- and extra-cellular ROS levels decreased significantly to 71.9% and 50.0% of the control at a moderate concentration of 20 microg/ml, respectively, suggesting that SEHP could easily enter the cells and play important roles in reducing ROS levels. Our results were proved by detection of DNA fragmentation and inspection of cell morphology of PC12 cells. SEHP can obviously block DNA fragmentation and prevent the cells from shrinking and turning round of H2O2-induced apoptosis in PC12 cells at concentrations of 10 approximately 100 microg/ml. This data suggests SEHP may be a candidate for application in neurodegenerative diseases such as Alzheimer's disease or Parkinson's disease.