Objective To explore effects of Huoxue Wentong Formula（活血温通方） on myocardial ischemia and its possible mechanism. Methods Male SD rats were randomly divided into sham operation group

model group

positive medicine group

as well as Huoxue Wentong Formula low

medium

and high dose groups

with 8 rats in each group. For all groups but the sham operation group

left anterior descending coronary arteries were ligated to prepare models of myocardial ischemia. After modeling

the positive medicine group was administrated with 6.3 mg/（kg·d） isosorbide mononitrate sustained release tablets

the Huoxue Wentong Formula low

medium and high dose groups were administrated with 0.42

0.84 and 1.68 g/（kg·d） Huoxue Wentong Formula respectively

the sham operation group and the model group were given equal volume of distilled water by gavage. Serum cardiac troponin I（cTn-I）

creatine kinase MB isoenzyme（CK-MB） and lactate dehydrogenase（LDH） levels were measured 4 weeks after continuous gavage. Cardiac structure was observed by HE staining

and Masson staining was applied for observing on myocardial fibrosis. Western blot was used for determining expressions of cardiac silent information regulator 1（Sirt1）

nuclear factor κB（NF-κB）

forkhead box protein O1（Foxo1） and p53 protein. Results Compared with the sham operation group

the serum levels of cTn-I

CK-MB and LDH in the model group were significantly increased（P<0.01）. Ischemic myocardium space was increased

muscle fibers were arranged disorderly

and infiltration of a large number of inflammatory cells occurred. At the same time

collagen fibrosis was severe

the Sirt1 protein expression was significantly decreased

and the NF-κB

Foxo1 and p53 protein expressions were increased（P<0.01）. Compared with the model group

the above indexes could be improved to different degrees in the positive medicine group and the medium dose Huoxue Wentong Formula group（P<0.05 or P<0.01）. The decrease of NF-κB and p53 protein expressions and the increase of Sirt1 expression in the medium dose Huoxue Wentong Formula group were more significant than those in the low dose Huoxue Wentong Formula group（P<0.01）. And it was also better than the high dose Huoxue Wentong Formula group in decreasing CK-MB and LDH levels

as well as expressions of NF-κB

Foxo1 and p53 protein（P<0.05 or P<0.01）. It was also effective in improving cardiac pathology in the medium dose Huoxue Wentong Formula group. Conclusion Huoxue Wentong Formula may reverse pathological changes of ischemic heart by up-regulating Sirt1 signaling pathway

thereby improving myocardial ischemic injury

and the efficacy is best at medium dose.