Objective: To study the protective effect of notoginsenoside R1 on acute myocardial ischemia (AMI) in rats. Method: The SD rats were randomly assigned to 5 groups: normal group

model group

diltiazem group (5 mg·kg-1)

notoginsenoside R1 groups (5

10 mg·kg-1

respectively). The changes of electrocardiogram in AMI rats were observed after treatment. The levels of aspartete transaminase (AST)

creatine kinase (CK)

creatine kinase isoenzyme (CK-MB)

lactate dehydrogenase (LDH)

and lactate dehydrogenase-1 (LDH1) in serum were detected and analyzed. The double staining method was used for the determination of the ischemic area. Additionally

the histopathological changes of cardiac tissue were observed of by HE staining.The expression of B cell lymphoma/leukemia-2(Bcl-2)

Bcl-2-associated X protein(Bax) proteins in cardiac tissue were observed using Western blot analysis. Result: Compared to model group

notoginsenoside R1 lessened the elevation value of ST-segment and inversion rate of T-wave (P<0.01)

and effectively reduced the levels of myocardium enzyme in serum (P<0.05)

in addition

notably reduced the area of myocardial ischemia in AMI rats (P<0.01). And the pathological damages of myocardial ischemia were improved. Meanwhile

the expression of Bcl-2 protein in heart tissue was increased

whereas the level of Bax protein was decreased (P<0.01). Conclusion: The results suggest that notoginsenoside R1 has protective effect on AMI rats

and mechanisms may be related to lessening the release of myocardium enzyme in serum and inhibiting the apoptosis of cardiomyocyte.