OBJECTIVETo investigate the protective effect of epimedium flavonoids Injection (EFI) on experimental acute myocardial infarction (AMI) rats.

METHODSRats were randomly divided into 6 groups, the acute myocardial infarction model was established by ligating left anterior descending branch of coronary artery (LAD). After operation, the rats in the sham-operation and model group were intravenous injected with 5% glucose injection, those in the positive medicine group were intravenous injected with nitroglycerin 0.3mg/kg, while rats in the low-, middle- and large-dose EFI group were intravenous injected with TFE in a dose of 10, 20, 40 mg/kg respectively. ECG was monitored before and after coronary artery ligation, and after treatment at different time points. At the same time, the millivolt of ST and ST-T segment were measured. The changes of serum creatine phosphokinase (CPK), lactate dehydrogenase (LDH), superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were determined, and the myocardial infarcted area was detected by MTT respectively 3 h after LAD. Results After intravenous injection of EFI in a dose of 10, 20, 40 mg/kg, the myocardial infarcted area of AMI rats could be decreased in different degree, the activity of serum CPK, LDH and the content of MDA decreased (P < 0.05 or P < 0.01), while the activity of serum SOD increased significantly (P < 0.05 or P < 0.01). It could began to lower the elevated ST-T segment 5 min after medication and the action could last for 3 h (P < 0.05 or P < 0.01).

CONCLUSIONEFI has a protective effect against acute myocardial ischemia caused by LAD, and the effect is quickly initiated.