Objective:To study the mechanism and protective effects of tilianin on myocardial ischemia-reperfusion injury（MIRI） in rats.Method: Sixty Wistar rats were randomized into sham operation group

model group

positive control and tilianin high

medium

low dose groups（n=10）.Rats in tilianin group were perfused with Tilianin（5.0

2.5

1.5 mg·kg-1·d-1） a week before operation

positive control group were perfused with propranolol at 25 mg·kg-1·d-1

to the sham operation group and the model group

0.5% CMC-Na was given instead.The MIRI model was established by ligating left anterior descending coronary artery for 30 min and followed for 120 min.To observe the changes of ST segment on ECG during ischemia and reperfusion and pathological changes after reperfusion.The activity of lactate dehydrogenase（LDH）

aminotransferase（AST）

creatine kinas（CK）

creatine kinase isozyme（CK-MB）

superoxide dismutase（SOD）

glutathion peroxidase（GSH-Px） and the contents of malondialdehyde（MDA）

interleukin-1（IL-1）

IL-6

tumor necrosis factor alpha（TNF-α） in serum were detected.Result: Compared with model group

the changes of ST segment elevation were attenuated by tilianin significantly during ischemia and reperfusion.Tilianin groups ameliorated the damage of myocardial pathomorphology markedly.Significantly the release of myocardium enzyme in serum decreased（P<0.01

P<0.05）.Tilianin high

medium dose group can increase the activity of SOD

GSH-Px and decrease the content of MDA

IL-1

IL-6

TNF-α（P<0.01

P<0.05） in serum.Conclusion: Tilianin has a significant protective effect on MIRI in rats.The mechanism of cardioprotection may be associated with clearing oxygen free radial（OFR） and lowering release of inflammatory factors.