Effects of EGb761 on the Dynamic Alterations of Magnesium, Glucose, and Lactate Level in the Brain Cortex of Gerbils during Focal Cerebral Ischemia

The aim of this study was to evaluate the pharmaco logical effect of EGb761 on the dynamic alterations of the level of magnesium, glucose, and lactate in the brain cortex of gerbils during focal cerebral ischemia. A single-dose of E Gb761 (100 mg/kg, i.p.) was given 30 min prior to cerebral ischemic surgery. Cerebral ischemia was in duced by occlusion of the right middle cerebral art ery (RMCA) for 180 minutes. Two microdialysis probes were stereotaxically implanted bilaterally into the brain cortex for auto-samplin g the extracellular fluid. Experimental result showed that pretreatment gerbil with EGb761 could preserve the highest Mg and glucose level in the con tralateral (non-ischemic) brain. Meanwhile, the lowest lactate concentration was observed in th e contralateral (non-ischemic) brain in gerbils pre treated with EGb761. Interestingly, an opposite result concerning the level of Mg, glucose, and lac tate was found in the ipsilateral (ischemic) brain in EGb761 pretreated subject. Based on our present finding, it seems likely that due to the ph armacological and compensatory effect, EGb761 can exert its biological effects by preserving more Mg and glucose level but not the lactate concentrat ion in the contralateral brain. Also, this phenomen on, 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-ischem ic brain from further serious cerebral ischemic challenge.