Objective: To observe the effect of Sanhua Tang on expression of MMP-9 in brain tissues of cerebral ischemia-reperfusion rat. Method: The rats were randomly allotted 5 groupa as following: sham operation group

model group

low dose group of Sanhua Tang(7.2 g·kg-1)

large dose group of Sanhua Tang(14.4 g·kg-1)ig

and nimodipine group(8.1 mg·kg-1)ig. After 3 days of routine breeding

Sanhua Tang was administered to rats by intragastric administration once every day for a week.The cerebral ischemia reperfusion model was reproduced by blocking middle cerebral arteryt with suture method. The expression of MMP-9 protein was detected by immunohistochemical methods with marketable kit

and mRNA expression of MMP-9 was assayed by RT-PCR. Result: In model group the expression of MMP-9 and MMP-9 mRNA in brain tissues was significantly increased(P<0.01).In large dose group of Sanhua Tang the expression of MMP-9 and MMP-9 mRNA was significantly decreased (P<0.01).In nimodipine group the expression of MMP-9 and MMP-9 mRNA was significantly decreased (P<0.05).In low dose group of Sanhua Tang the expression of MMP-9

and MMP-9 mRNA was less significantly decreased. In large dose group of Sanhua Tang the expression of MMP-9

MMP-9 mRNA was decreased more significantly than in nimodipine group. Conclusion: The mechanism of Sanhua Tang protecting against injure of cerebral ischemia reperfusion may be involved in ameliorating MMP expression.