Pre-Treatment with Metformin in Comparison with Post-Treatment Reduces Cerebral Ischemia Reperfusion Induced Injuries in Rats

Objective: to explore the effects of pre versus post ischemic treatment with metformin after global cerebral ischemia in rats. methods: male wister rats underwent forebrain ischemia by bilateral common carotid artery occlusion for 17 min. metformin (200 mg/kg) or vehicle was given orally by gavage for 7-14 days. rats were divided into: control, metformin pre-treatment, metformin post-treatment and metformin pre and post continuous treatment groups. cerebral infarct size, histopathology, myeloperoxidase and serum malondialdehyde were measured 7 days after ischemia. results: histopathological analysis showed that metformin pre-treatment significantly decreased leukocyte infiltration, myeloperoxidase activity and also malondialdehyde level. metformin pre-treatment and metformin post-treatment reduced infarct size compared with the control group, but it was not significant in the pre and post continuous treatment group. conclusion: our findings suggest that pre-treatment with metformin in comparison with post- treatment in experimental stroke can reduce the extent of brain damage and is more neuroprotective at least in part by inhibiting oxidative stress and inflammation.