Screening Of Anti- Myocardial Ischemia Effective Parts Of Xiangdan Injection And Mechanism Studies

Objective:To optimize the effective parts of xiangdan injection against myocardial ischemia and study its possible pharmacological mechanism. In this study, it was provide the scientific basis for quality control method and material basis study of anti-myocardial ischemia to clinical medicine.Methods:(1) pharmacodynamic evaluation : By the normal pressure anoxia animal model, it was investigated the effect of 5 different polar solvents extraction:the petroleum ether extracts of the Xiangdan injection group(A), the chloroform extracts of the Xiangdan injection group(B), the acetic ether extracts of the Xiangdan injection group(C), the n-butanol extracts of the Xiangdan injection group(D), the water extracts of the Xiangdan injection group(E) and 12 compound extracts of xiangdan injection(DE,AE,CE,ABCDE,ABC,AB,ACD,ADE,BCE,BD,BDE,CD) on the survial time of mice under the normal pressure and hypoxia;the rat model of acute myocardial ischemia was induced by ranine vein injection of pituitrin 0.5 U /kg,to observe the effect of 5 different extracts of the Xiangdan injection groups and 12 compound extracts of xiangdan injection groups(DE,AE,CE,ABCDE,ABC,AB,ACD,ADE,BCE,BD,BDE,CD)by examining the changes of T-waves ofⅡlead at different time point after injecting pituitrin; Parameters on changes of hemodynamics including heart rate(HR), systolic blood pressure (SBP), diastolic blood pressure(DBP), mean aortic pressure (MAP), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure(LVEDP), maximal ascending rate of left intraventricular pressure (+dp/dtmax), maximal descending rate of left intraventricular pressure (-dp/dtmax) and the interval time from that when the left ventricular begins contracting to the dp/dtmax( t-dp/dtmax) were recorded before and 5, 10, 15min after injection by cannulating femoral artery, right common carotid artery and consecutive electrocardiographicⅡ. (2) pharmacodynamic screening: Zhen's model and a support vector machine (SVM) model were established for pharmacodynamics prediction of TCM prescriptions to screen the active fraction of xiangdan injection.(3) Effect and mechanism reseach: Myocardial ischemia of rats was induced by subcutaneous injection of isoprenaline(5mg·kg-1) and intrapertitoneal injection of isoprenaline(5mg·kg-1) once a day for consecutive 3 days.the descent of J point at different time after injecting isoprenaline were examined,and the serum lactate de-hydrogenase (LDH),creatine kinase (CK), superoxiade dismutase (SOD) and malondial dehyde (MDA) in the myocardial homogenate were measured ; the hearts were examined with microscope.Results: (1) pharmacodynamic evaluation : D,E,DE,BDE,ADE and ABCDE groups could significantly prolong the survival time(P<0.05) ,DE and ADE groups are significantly different with the Xiangdan injection(P<0.05);C,CE,ADE,BCE and BDE groups could inhibition the raise of T-wave in 0s, 5s and 10s(P<0.05), which induced by Pituitrin;.5,10,15 min after injecting the corresponding drug ,the SAP,DAP,LVSP and -dp/dtmax of anesthetized rats rose significantly in group (D)(P<0.01 or P<0.05), however, there were no significant changes of LVEDP, +dp/dtmax and t-dp/dtmax in group (D); the +dp/dtmax and -dp/dtmax of anesthetized rats rose significantly in group (ABC)( P<0.05), there were significant changes of LVEDP in 5min, LVSP and -dp/dtmax of anesthetized rats rose significantly in group BCE and ABCDE from 5 min to 15min after injecting( P<0.05).(2) pharmacodynamic screening: Zhen's model and a support vector machine model were established for pharmacodynamics prediction of TCM prescriptions to screen the effective parts of xiangdan injection through three pharmacodynamic indexs: the survial time of mice under the normal pressure; the changes of T-waves ofⅡlead and two hemodynamics parameters :left ventricular systolic pressure (LVSP) and left ventricular end-diastolic pressure(LVEDP), The model could predict that ADE had the best effect.(3) Effect and mechanism reseach: Low-dose group and middle-dose group of compound extracts(ADE) of Xiangdan injection significantly reduced the activities of LDH,CK and the level of MDA, enhanced the activities of SOD and showed less histological change.Conclutions: The present model could predict the drug actions for different combinations of the formulations, the pharmacodynamic actions of several formulas were superior to the original formulation, and ADE had the best effect; compound extracts (ADE)of Xiangdan injection had a protective effect against isoproterenol-induced myocardial injury in rats, it may be relevant to its antioxidant and anti-lipid peroxidation properties.