Prevent And Cure Effects Of XNSK On Myocardial Ischemia-Reperfusion Injury In Rats

Objective:To screen XNSK on myocardial ischemical injury and establish quality control standard. Methods: Orthogonal design testing method was used to optimize the compatibility of XNSK with TP, Egb761, PNS, DS by myocardium antioxidation in vitro. Method independent variables were inhibition ratio of materials to MDA. A new thin layer chromatography (TLC )method was set up for examination of composition in XNSK respectively. A high performance liquid chromatography( HPLC) method for detecting the total content and the lower limit content of EGCG in XNSK was given according to several of tablets testing result. Results: The best compound of XNSK on myocardial ischemical injury was screened. They were unfolded with different systems by TLC respectively and all displayed single spot.The R_f's figure of major spot was 0.43, 0.59, 0.61, 0.45 successively.The EGCG's determination content of XNSK is 197.76mg.g^-1,caculating the content of EGCG in the sample by external reference method of HPLC. According to experimental results, the XNSK tablets'draft quality control standard was formulated.Conclusions: The best compound of XNSK is screened in preliminary experiment. To be suitable quality control for XNSK, determination content of EGCG in XNSK is 197.76mg.g^-1. These also showed that the analytical method is reasonable and practical, the quality is controllable. Objective: To study the effects and mechanism of XNSK on preventing and curing the acute myocardial ischemia-reperfusion injury in rats. Methods: The acute myocardial ischemica-reperfusion injury model in rats was established by ligation of left anterior descending coronary artery for 30 min followed by reperfusion for 60 min, and haemodynamics in rats were detected by inner cordis cannula; Several biochemical indices were measured to evaluate the antioxidational mechanism; AST,LDH,LDH-1,CK and CK-MB were measured to investigate the effect of XNSK on serum myocardial enzymology changes of myocardial ischemical reperfusion injury;The platelet aggregation induced by ADP was detected to investigate the mechanism of microcirculation; Pathological sections were used to study the pathologic changes of myocardium and ultrastructural changes of myocardium were observed under electronmicroscope;The expression of apoptosis - correlated protein Bcl-2 and Bax were analyzed. Results: Comparing with model group, the results showed that XNSK increased heart rate (HR), left ventricular systolic pressure (LVSP), the maximum of upstroke velocity on left intraventricular pressure (+dp/dt_max), the maximum of drawdown velocity on left intraventricular pressure (-dp/dt_max), and decreased left ventricular end-diastolic pressure (LVEDP). The effects were correlated with the dosage; Comparing with the model group, the activity of SOD and the content of ATPase was increased by XNSK (P<0.05), but the content of MDA,ROS,NOS in homogenate of myocardial tissue was reduced respectively(P<0.05).The effects were concerned with dosage; XNSK could decrease the platelet aggregation induced by ADP; Histopathological examination confirmed that, the degree of myocardial injury and ultrastructure of myocardium in high dosage of XNSK groups was obviously lessened compared with model group(P<0.05); XNSK could downregulate the expression of Bax and the ratio of Bax /Bcl-2 (P<0.05),and significantly increased the expression of Bcl-2 (P<0.01). Conclusions: XNSK preconditioning has the protective effects on myocardial ischemical reperfusion injury in Wistar rats. The mechanism will be possibly related to antioxidation, antiplatelet aggregation,inhibiting the increasing of serum myocardial enzymology, depressing on apoptosis, lessening injury of pathology, thereby lead to antiischemia injury by multi-targets, multi- pathways, and co- effects .