HYDROGEN PEROXIDE-INDUCED OXIDATIVE DAMAGE AND APOPTOSIS IN CEREBELLAR GRANULE CELLS: PROTECTION BY GINKGO BILOBA EXTRACT

The ability of oxidative stress to induce apoptosis and the protective effects of Ginkgo biloba extract (EGb761) against this induction were studied in cultures of rat cerebellar granule cells. Cells were exposed to oxidative stress by treatment with 50 μm hydrogen peroxide+100 μm ferrous sulphate which generates hydroxyl radicals by Fenton reaction. Both morphological observation and biochemical analysis revealed that H2O2/FeSO4treatment induced apoptotic cell death in cerebellar granule cells, which was characterized by chromatin condensation and DNA fragmentation. During this process, the fluidity of the cell membrane decreased markedly, and the conformation of membrane proteins altered significantly. Pretreating cerebellar granule cells with the antioxidant EGb761 (Ginkgo biloba extract) effectively attenuated oxidative damage induced by H2O2/FeSO4, and prevented cells from apoptotic cell death. The results suggested that EGb761 might be used as a potential drug for neuronal diseases associated with the excessive production of reactive oxygen species.