Preventive Effect of Total Flavones of Choerospondias axillaries on Ischemia/Reperfusion-Induced Myocardial Infarction-Related MAPK Signaling Pathway

Choerospondias axillaris (Guangzao) is a medicinal plant used in Mongolia, and its fruit is commonly used for the treatment of cardiovascular diseases in clinic. The constituents responsible for this effect are always conceded to be the total flavonoids of C. axillaries (TFC). The present study was to evaluate the preventive effect of TFC on acute myocardial infarction induced by ischemia/reperfusion (I/R) in rats and the possible signaling pathway involved. The model of myocardial I/R was caused by occlusion of the left anterior descending coronary artery for 30 min followed by reperfusion for 2 h. Cardiac dysfunction, infarct size, pathologic histology and apoptosis were examined. Heart tissues were homogenized for biochemistry assays and Western blots analysis. The results indicated that pretreatment with TFC strongly improved cardiac function, obviously reduced heart pathologic lesion in I/R rat hearts. TFC also could protect the heart from I/R injury by increasing the levels of catalase, glutathione peroxidase and superoxide dismutase in heart homogenate, and decreasing that of malondialdehyde level. These beneficial effects were associated with the decrease in TUNEL-positive nuclear staining, Bax and caspase-3 levels, and the increase in Bcl-2 expression. Moreover, TFC counteracted the I/R-induced decreased activation of p38 mitogen-activated protein kinase (MAPK) and Jun N-terminal kinase. These data suggested that TFC improved I/R-induced myocardium impairment via anti-oxidative and anti-apoptotic activities, and this beneficial effects were intervened by MAPK signaling pathway.