Prevention of oxidative injury by flavonoids from stems and leaves of Scutellaria baicalensis Georgi in PC12 cells.

Reactive oxygen species (ROS) are important mediators in a number of neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). The neuroprotective effects of flavonoids from the stems and leaves of Scutellaria baicalensis Georgi (SSF) against hydrogen peroxide (H2O2)-induced rat pheochromocytoma line PC12 injury were evaluated by cell lesion, free radicals and ATPase disorders. Following a 30 min exposure of the cells to H2O2 (100 microm), a marked decrease in cell survival and activity of superoxide dismutase (SOD) and Na+-K+-ATPase as well as an increase of malondialdehyde (MDA) production and lactate dehydrogenase (LDH) release were observed. Pretreatment of the cells with SSF (18-76 microg/mL) prior to H2O2 exposure notably elevated the cell survival and activity of SOD and Na+-K+-ATPase, and lowered the MDA level and LDH release. Neuroprotection by SSF was also observed in animal models. The present results indicated that SSF exerts neuroprotective effects against H2O2 toxicity, which might be of importance and might contribute to its clinical efficacy for the treatment of neurodegenerative disease. Copyright 2006 John Wiley & Sons, Ltd.