Protective Effects Of Curcumin On Myocardial Ischemia Reperfusion Injury In Rats

ObjectiveThe effects of curcumin on the hemodynamic parameters,lactate dehydrogenase (LDH)activity,myocardial infarct size,the release of purine nucleotide catabolites, purine nucleoside phosphorylase(PNPase)activity and the sarcoplasmic reticulum (SR)Ca²⁺-ATPase activity,Ca²⁺uptake,Ca²⁺release of isolated rat hearts were observed.To explore the protective effects of curcumin on myocardial ischemia reperfusion injury in rats.MethodsSixteen Wistar rats were randomly divided into tow groups.Isolated rat hearts were mounted on a Langendorff perfusion apparatus.Control group,isolated rat hearts were perfused with Krebs-Henseleit(K-H)perfusion buffer and maintained for 20 min of heart working,ischemia for 30 min and reperfused for 30 min. Curcumin group,isolated rat hearts were perfused with K-H buffer containing curcumin(0.2 mmol/L)and maintained for 20 min of heart working,ischemia for 30 min and reperfused for 30 min.Before ischemia the hemodynamic parameter(heart rate,systolic pressure,coronary artery flow,cardiac output)were observed.After the reperfusion,the purine nucleotide catabolites(uric acid,hypoxanthine,xanthine, inosine,adenosine)and PNPase activity of arteriae aorta and coronary artery effluent were assayed by HPLC.The LDH activity was determined by ultraviolet spectrophotometry.The myocardial infarct size was determined by the TTC staining method.The myocardial SR was extracted with differential centrifugation.The protein concentration was determined by Folin-Phenol method.The Ca²⁺uptake of myocardial SR Ca²⁺-ATPase(Ca²⁺pump)and the Ca²⁺release of Ryanodine receptor (RyR)/ Ca²⁺release channel were observed by spectrophotometry.The myocardial SR Ca²⁺-ATPase activity was determined by enzyme coupling assay.Results1 Effects of curcumin on the hemodynamics parameters,LDH activity and infarct size of rat heartsThe heart rate,systolic pressure,and cardiac output in curcumin group and control group had no difference(P＞0.05).The coronary artery flow in curcumin group was higher than that in control group(P＜0.05).The LDH activity in curcumin group was lower than that in control group(P＜0.01).The myocardial infarct size in curcumin group was less than that in control group(P＜0.05).2 Effects of curcumin on the release of purine nucleotide catabolites and PNPase activity of myocardial ischemia reperfusion injury in ratsThe release of uric acid and xanthine in curcumin group and control group had no difference(P＞0.05).The release of hypoxanthine and PNPase activity in curcumin group were lower than those in control group(P＜0.05).While the release of inosine and adenosine in curcumin group were higher than those in control group (P＜0.05).3 Effects of curcurnin on myocardial SR Ca²⁺uptake,Ca²⁺release and Ca²⁺-ATPase activityThe maxium of Ca²⁺uptake and Ca²⁺release and the Ca²⁺-ATPase activity of myocardial SR in curcumin group were higher than those in control group(P＜0.05).ConclusionsCurcumin can improve the hemodynamic parameters,increase the coronary artery flow and reduce the myocardial infarct size and the LDH release of myocardial cells.Consequently,curcumin can protect ischemia-reperfused myocardium.Curcumin can improve the energy metabolism of ischemia-reperfused myocardium by reducing the release of purine bases and the consumption of high-energy phosphate bond.Therefore,curcumin can protect ischemia-reperfused myocardium.The function of myocardial SR Ca²⁺uptake and Ca²⁺release was improved, indicating that curcumin can promote the recovery of contractile and diastolic function and reduce the cytosolic Ca²⁺overload.Consequently,curcumin can protect ischemia-reperfused myocardium.The results of this study indicate that curcumin can protect ischemia-reperfused myocardium.The findings might provide new clue for further researches on the protective mechanisms of curcumin on myocardial ischemia reperfusion injury.