Protection of PC12 cells from hydrogen peroxide-induced cytotoxicity by salvianolic acid B, a new compound isolated from Radix Salviae miltiorrhizae

A number of studies indicate that reactive oxygen species (ROS) are involved in neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). The neuroprotective effects of salvianolic acid B (SalB) from Radix Salviae miltiorrhizae (RSM) against hydrogen peroxide (H 2O 2)-induced rat pheochromocytoma line PC12 injury were evaluated in the present study. Vitamin E, a potent antioxidant, was employed as a positive control agent. Following exposure of cells to H 2O 2 (150 μM), a marked decrease in cell survival and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), as well as increased levels of malondialdehyde (MDA) production and lactate dehydrogenase (LDH) release were observed. In parallel, H 2O 2 caused significant elevation in intracellular Ca 2+ level and caspase-3 activity, and induced apoptotic death as determined by flow cytometric assay. However, pretreatment of the cells with SalB (0.1–10 μM) prior to H 2O 2 exposure blocked these H 2O 2-induced cellular events noticeably. Moreover, SalB exhibited significantly higher potency as compared to Vitamin E. The present findings indicated that SalB exerts neuroprotective effects against H 2O 2 toxicity, which might be of importance and contribute to its clinical efficacy for the treatment of neurodegenerative diseases.