Abstract: AIM: To study the protectective effect of bacalin on myocardial ischemia in isolated rat heart and its mechanism.METHODS: Thirty six Sprague-Dawley rats were randomly divided into 3 groups.The heart of rats in control group (n=12) were perfused for 1 h and 50 min incessantly.The heart of rats in ischemia group (n=12) received 25min of perfusion first and then subjected to 25 min of global ischemia followed by 1 h reperfusion.The heart of rats in baicalin group (n=12) received 5 min perfusion of 5 mg/L) baicalin before ischemia while other procession was the same as ischemia group.The hemodynamic measurement and the coronary flow were recorded.The levels of CK and LDH in the coronary effluent were detected.The expression of p38mapk, NF-κB and the levels of TNF-ê and IL-6 in myocardium were respectively detected by immumohisto- chemical technique and ELISA.RESULT: The function of hearts treated with baicalin was improved significantly, and the level of LDH and CK of coronary effluent were decreased significantly compared with ischemia group. The level of TNF-ê and IL-6 and the expression of p38mapk and NF-κB in myocardium also decreased observably compared with ischemia group.CONCLUSION: Baicalin has a protective effect on myocardial ischemia of isolated rat heart and the effect may be due to the decrease of TNF-ê and IL-6 induced by the reduction of the expression of p38mapk and NF-κB.

Key words: baicalin, isolated rat, myocardial ischemia, p38mapk, NF-кB, TNF-α, IL-6