Effect of Shenfu injection on expressions of matrix metalloproteinase-9 and tissue inhibitors of metalloproteinase-1 in rats after cerebral ischemia-reperfnsion injury

Abstract

Objective To investigate the effect of Shenfu injection on the expressions of matrix metalloproteinase-9 (MMP-9) and tissue inhibitors of metalloproteinase-1 (TIMP-1) in rats after cerebral ischemia-reperfusion injury,and explore the brain protection mechanism of Shenfu injection. Methods Ninety adult healthy male Wister rats were chosen and randomly divided into sham-operated group,Shenfu injection treatment group and vehicle group (n=30); animal models of middle cerebral artery occlusion/reperfusion in the later 2 groups were established by a filament method in the left external-internal carotid artery.Rats in the Shenfu injection treatment group were injected with 8 mg/kg Shenfu injection during the reperfusion while those in the vehicle group with physiological saline.These rats in each group were divided into 3 sub-groups (n=10) according to the ischemia time (0.5,1 and 1.5 h after the model establishment). Twenty-four h after reperfusion, dry-weight method was employed to detect the content of brain tissues on the side received ischemia-reperfusion; and Western blotting was employed to observe the expressions of MMP-9 and TIMP-1 in the brain tissues. Results The water content of those brain tissues and the expressions of MMP-9 and TIMP-1 in the Shenfu injection treatment group and vehicle group at each time point significantly increased as compared with those in the sham-operated group (P＜0.05); the longer the ischemic time,the heavier the water content of the brain tissues and the higher the expressions of MMP-9 and TIMP-1. As compared with those in the vehicle group, the water content of the brain tissues and the expression of MMP-9 in the Shenfu injection treatment group obviously decreased,while the expression of TIMP-1 in the Shenfu injection treatment group significantly increased at each time point (P＜0.05). Conclusion Shenfu injection has the function against cerebral edema by accommodating the expressions of MMP-9 and TIMP-1. Key words: Shenfu injection; Cerebral ischemia/reperfusion; Brain edema; Matrix metalloproteinase-9