Objective:By measuring the level of myeloperoxidase (MPO)

infarction weight ratio

myocardial cell morphology

to observe the myocardial protective effects and possible mechanism of Tiaozhi Tongluo capsules for myocardial ischemia-reperfusion injury (MIRI). Method: Ninety-six male Wistar rats were fed with high fat diet for 4 weeks except the non-fat model group. The rats were randomized into six groups and drug intervention or saline for 4 weeks: (1) fat model group; (2) non-fat model group; (3) statin group; (4) Tiaozhi Tongluo capsules 8.64 g·kg-1·d-1; (5) Tiaozhi Tongluo capsules 4.32 g·kg-1·d-1; (6) Tiaozhi Tongluo capsules 2.16 g·kg-1·d-1. The same volume of saline was infused in fat model and non-fat model group. After 2 hours of the last intragastric infusion

the chest was opened and the left anterior desending coronary arteries (LAD) was ligated for 30 min and unclamped for 24 hours for all the rats. After 24 h of reperfusion

the level of blood lipids

cardiac enzymes in serum or the content of MPO in ischemic myocardium tissue (half of the animals of each group) were measured. Myocardial tissue near the apical about 0.5 cm2 was taken for HE staining

morphological changes were observed. The myocardial tissue of the rest animals in each group was stained by Evans blue and TTC. Then these slices were immersed in 4% paraformaldehyde formalin

ischemic zone size (IZS)

infarct size (IS)

the ischemic weight ratio and the infarction weight ratio were determined. Result: The level of cardial enzymes

MPO and infarction weight ratio were significantly higher in fat model group compared to the non-fat model group(P<0.01). The drug treatment groups could significantly reduce the level of cardial enzymes

MPO and infarction weight ratio compared to fat model group(P<0.01). Conclusion: Tiaozhi Tongluo capsules and atorvastatin could protect myocardial cells by reducing the infiltration of inflammatory cells

which might be related to the effects of lowering blood lipids and protecting endothelial function. No clear does-dependent effects were found for Tiaozhi Tongluo capsules.