Objective: To observe the effect of Kangnaoye on the expression of brain derived neurotrophic factor (BDNF)

matrix metalloproteinase-9 (MMP-9)

extracellular signal regulated kinase 1/2 (ERK1/2) in rat with cerebral ischemia reperfusion injury

and to study its cerebral protection mechanism. Method: Male SD rats were randomly divided into the sham-operation group

the ischemia reperfusion (I/R) group

the high-

medium-

and low-dose Kangnaoye groups (28.6

14.3

7.15 g·kg-1·d-1). The cerebral ischemia reperfusion model was prepared in rats by a improved Zea Longa method. The rats were killed at 1-

6-

12-

24-

72-and 168-h reperfusion after 2-h ischemia. The expression of BDNF

MMP-9 and ERK1/2 were observed by using immunohistochemical method. Result: Compared with I/R group

the expression of BDNF and ERK1/2 was upregulated

the numbers of MMP-9 positive cells decreased in the high-and medium-dose Kangnaoye groups (P <0.05). Moreover

the infarct volume decreased significantly at 24-reperfusion (P <0.05). Conclusion: Kangnaoye could protect neurovascular unit by promoting the expression of BDNF in brain tissue

activating ERK1/2 signaling pathway

and inhibiting the expression of MMP-9.