Effect of EGb761 on the Dynamic Changes of Energy Metabolites and Bio-Metal in the Brain Cortex of Gerbil during Focal Cerebral Ischemia

The aim of this study was to evaluate the pharmacological effect of EGb761 on the dynamic alterations of magnesium (Mg) and energy metabolites including glucose and lactate in brain cortex of gerbil during focal cerebral ischemia. A single dose of EGb761 (100 mg/kg, i.p.) was given 30 min prior to cerebral ischemic surgery. Cerebral ischemia was induced by occlusion of the right middle cerebral artery (RMCA) for 180 minutes. Two microdialysis probes were stereotaxically implanted bilaterally into the brain cortex for auto-sampling the extracellular fluid. Experimental result showed that pretreatment gerbil with EGb761 could preserve the highest Mg and glucose level in the contralateral (non-ischemic) brain. However, the lowest lactate concentration was observed in the contralateral (non-ischemic) brain in gerbil pretreated with EGb761. Interestingly, an opposite result concerning the level of Mg, glucose, and lactate was observed in the ipsilateral (ischemic) brain in EGb761 pretreated subject. Based on our present results, it seems likely that due to the pharmacological and compensatory effect, EGb761 can preserve more Mg and glucose level but not the lactate concentration in the contralateral brain. Also, this positive phenomenon, at least in part, may be helpful for the non-ischemic brain not only in preserving more Mg and glucose level, but also in preventing the non-ischemic brain from further serious cerebral ischemic challenge.