Protective effects of flavonoids in the roots of Scutellaria baicalensis Georgi against hydrogen peroxide-induced oxidative stress in HS-SY5Y cells

Oxidative stress plays an important role in the pathological process of neurodegenerative diseases. The effects of four major flavonoids present in Scutellaria baicalensis Georgi on hydrogen peroxide induced neuronal cell damage are studied in this paper. When human neuroblastoma SH-SY5Y cells were incubated in Hanks' solution with the addition of 400 muM hydrogen peroxide for 2 h, the viability of cells was decreased remarkably, while the cell lipid peroxidation and the percentage of lactose dehydrogenase released into the culture medium was significantly increased. Addition of 10 muM Of baicalein and baicalin significantly attenuated the cellular injury induced by hydrogen peroxide, while the effect of wogonin was marginal and wogonoside showed no effect at the tested concentration. In a separate experiment, 10 muM of baicalein and baicalin also antagonized the intracellular free-calcium concentration ([Ca2+](i)) increase caused by 1 mM hydrogen pet-oxide. The effects of baicalein in both experiments were similar to those of quercetin, a well-studied antioxidant flavonoid. These results demonstrated the protective effects of flavonoids originating from Scutellaria baicalensis Georgi on the oxidative injury of neuronal cells. (C) 2001 Academic Press.