Protection of total flavones from Microcos paniculata on acute myocardial ischemia in rats and its mechanism

Objective To study the protective effect of the total flavones in Microcos paniculata(TFMP) on the acute myocardial ischemia(AMI) induced by isoprenaline(ISO) and its mechanism.Methods The rats were ig administered with TFMP(8,4,and 2 mg/kg) once daily for consecutive 5 d,and the AMI rat model was established by sc injection with ISO(2 mg/kg) 1 h after the last administration.The effects of TFMP on the electrocardiogram(ECG) at different time points and the myocardial tissue pathological histomorphology dying by hematoxylin were observed;The superoxide dismutase(SOD) and malondialdehyde(MDA) levels of myocardial tissue,glutathione peroxidase(GSH-Px),lactate dehydrogenase(LDH),and creatine kinase(CK) activities in serum were detected using biochemical method.Results Compared with the model group,the high-and mid-doses(8 and 4 mg/kg) TFMP inhibited the J spot downward of ECG during myocardial ischemia(P 0.05),especially after 10 min of ISO injection.The myocardial injury induced by ISO was aslo improved in these two groups,the levels of LDH and CK in serum(P 0.05) and the content of MDA in myocardial homogenate(P 0.01) were decreased,the activities of SOD(P 0.01) and GSH-Px(P 0.05,0.001) in the myocardial homogenate were increased.Conclusion The TFMP has the apparent protective effect on AMI injury,its mechanism may be related with improving the myocardial anti-oxidative ability and decreasing the oxidative stress reaction.