Effects of salvianolate lyophilized injection on neural functional recovery and the expression of microtubule associated protein-2 after focal cerebral ischemia-reperfusion injury in diabetic rats

Abstract

Objective To investigate the effects of salvianolate lyophilized injection(SLI) on neural functional recovery and the expression of microtubule associated protein-2(MAP2) after focal cerebral ischemia-reperfusion injury in the diabetic rats. Methods Diabetes model was made by intraperitoneal injection of streptozotocin (STZ) and cerebral ischemia-reperfusion model was developed by Longa suture occluded method in the middle cerebral artery of diabetic rats. The rats were randomly divided into five groups: sham operation group, model group, SLI (21.0 mg.kg-1, 10.5 mg.kg-1) treatment groups, and edaravone (6 mg.kg-1) treatment group.3 hours after ischemia, rats were respectively given normal saline or drugs followed by the injection once a day for 14 days and the neurological impairment was assessed. 2 h after the last injection, the rats were decapitated and the brains were collected. The expression of MAP2 protein and mRNA in the bilateral hippocampal ischemia and infarcted area was detected with immunohistochemistry and RT-PCR. Results Severe neurological dysfunction was found in diabetic rats that had been subjected to cerebral ischemic injury(1.850±0.457). A significant improvement on neurological function was found in the SLI treatment groups(1.581±0.314, 1.345±0.425) compared with model group(P<0.01, P<0.05=. Moreover, the expression of MAP2 in ischemia bilateral hippocampal CA1 and penumbra was represented by the average optical density value respectively (0.743±0.250, 0.561±0.224 ). In the hippocampal CA1 region, the number of MAP2-positive cells(0.781±0.420, 0.851±0.136) in the treatment group showed significant increase than those in model group (P<0.01, P<0.05=. In the ischemic penumbra region, the number of MAP2-positive cells (0.753±0.235, 1.203±0.326 ) in the treatment group showed significant increase than those in model group (P<0.01, P<0.05=. Conclusion The SLI can promote the post-injury neurocognitive function in diabetic rats. The increase of MAP2 expression may be involved in the mechanisms. Key words: Diabetes; Cerebral ischemia-reperfusion injury; Salvianolate lyophilized injection; Microtubule associated protein-2