Protective Effect of EGb 761 Against Oxidative Phosphorylation of Brain Mitochondria After Anoxia/Reoxygenation In Vivo and In Vitro.

The aim of this study was to investigate the effects of in vivo and in vitro anoxia and reoxygenation on the oxidative phosphorylation of brain mitochondria and to study the protective effects of Ginkgo biloba extract (EGb 761). Cerebral ischemia and reperfusion induced slight decreases in respiration rates and in the efficiency of oxidative phosphorylation. Total protection of mitochondrial function was observed after chronic pretreatment of rat with EGb 761. On the contrary, in vitro anoxia and reoxygenation of isolated brain mitochondria during respiratory assay promoted important alteration in respiration rates (around -50%) and in the oxidative phosphorylation yield (-44%). Partial protection was observed after anoxia and reoxygenation in the presence of EGb 761. Such a difference between in vivo and in vitro results could be explained by an intracellular antioxidant pool that could protect mitochondria in vivo.