Protection and mechanism of total flavones from Rhododendron simsii on myocardial ischemia-reperfusion injury rats / 中草药

ABSTRACT

Objective To study the protective effect of total flavone from Rhododendron simsii(TFRS) on myocardial ischemia-reperfusion injury rats and its mechanism.Methods The ischemic model was made by occluding the anterior descending of the left artery(LAD) in rats.The change of ST segment and T wave of electrocardiograph(ECG) were observed,and the activity of lactate dehydrogenase(LDH),creatine kinase(CK),levels of the maleic dialdehyde(MDA),and nitric oxide(NO) in serum were measured.And by tetrazolium chloride(TTC) staining,the areas of myocardial infarction were observed.The expression of inducible nitricoxide synthase(iNOS) in rats was detected by emploring the reverse transcription-polymerase chain reaction(RT-PCR) technique.Results On the myocardial infarction model by occluding the anterior descending of the LAD in rats,TFRS(100 mg/kg) obviously reduced the height of ST segment after occluding 30 min and TFRS(25,50,and 100 mg/kg) obviously reduced the height of ST segment after reperfusion 30 min.TFRS(50 mg/kg) reduced by myocardial infarction area.TFRS(50 and 100 mg/kg) obviously reduced the activity of CK and LDH.TFRS(50 mg/kg) decreased the level of MDA in serum.By RT-PCR technique,it was found that the expression of iNOS mRNA in myocardium in IR rats pretreated with TFRS(100 mg/kg) was higher than that in IR and normal groups.Conclusions TFRS has the significant protection against myocardial ischemia-reperfusion injury via atte-nuating oxygen free radical and increasing the expression of iNOS mRNA and NO production.