Objective: To observe the effect of modefied Si Junzitang on the expression of extracellular signal-regulated kinase1/2(ERK1/2)

protein kinase B(Akt) and B cell lymphoma/lewkmia-2 assaciated X protein(Bax) in rats with cerebral ischemia/reperfusion injury

and to explore its possible protective mechanism on nerve cells. Method: Totally 55 male SD rats were randomly divided into sham operation group

model group

edaravone group

modefied Si Junzitang low-dose group

middle-dose group

and high-dose group (3.69

7.38

14.76 g·kg-1). The middle cerebral artery occlusion (MCAO) model was induced by suture method

after 7d treatment

the rats were sacrificed and ischemic side brain tissues were taken. Phosphorylation of ERK1/2 (p-ERK1/2)

p-Akt and p-Bax protein contents were detected by Western blot; the mRNA expression levels of ERK1/2

Akt and Bax were detected by real time fluorescence quantitative polymerase chain reaction(Real-time PCR). Result: As compared with sham operation group

the p-ERK1/2

p-Akt and p-Bax protein and mRNA expression levels were significantly reduced in model group(P<0.01). As compared with the model group

the protein and mRNA expression levels of p-ERK1/2 and p-Akt were up-regulated

the expression of protein and mRNA of Bax were significantly reduced in low-dosed group

middle-dosed group

high-dosed group

with statistically significant difference (P<0.01). Conclusion: Modefied Si Junzitang can protects brain with cerebral ischemia/reperfusion injury by up-regulating the expression of p-ERK1/2 and p-Akt. reducing the expression of Bax.