Cardio-protective effects of the new crystal of puerarin in isoproterenol-induced myocardial ischemia rats based on metabolomics

OBJECTIVE To evaluate the cardio-protective effects of the new crystal of puerarin and investigate its potential therapeutic mechanism. METHODS A total of 60 male Sprague-Dawley rats were randomly divided into six groups（n=10）: the control group, the Isoproterenol（ISO）-damaged group, and the different drug administration groups, including the propranolol group,the original crystal of puerarin group, the low and high dose of the new crystal of puerarin groups. Besides, rats in the control group were subcutaneously injected with saline, and other rats in the model and drug-treatment groups were injected with ISO（85 mg·kg-1） for the final 2 consecutive days to establish the model of myocardial ischemia（MI）. And for control and model groups, the rats were intragastric administrated starch continuously for 7 d,and drug-treatment rats were respectively intragastric administered the new crystal of puerarin(30, 120 mg·kg;·d;),the original crystal of puerarin(120 mg·kg;·d;) and the positive drug(propranolol 15 mg·kg;·d;) for 7 d. In this research, the cardio-protective effect of the new crystal of puerarin in ISO-damaged experimental rats were evaluated by echocardiography detection, biochemical assays in serum levels（including CK, LDH, cTnT, cTnI,SOD, and MDA）, and myocardial histology analysis.Then nuclear magnetic resonance（NMR） analysis both in serum and heart tissues was used to investigate potential mechanism of the new crystal. RESULTS In this study, given ISO to rats caused significant increase in heart weight and the heart weight index. And the twodimensional and M-mode short-axis image of the left ventricle from model rats was obviously different from other groups. And the left ventricular internal dimensiondiastole（LVIDd） was significantly increased and ejection fraction（EF%） and fractional shortening（FS%） were obviously reduced in model rats. Compared with model group, aforesaid parameters were improved in all drugtreatment groups. For the biochemical assays of the serum, on the one hand, the contents of representative diagnostic markers of ischemia injury（CK, LDH, cTn-T and cTn-I） were obviously increased in ISO-damaged rats and apparently decreased after the drug-administration treatment. On the other hand, the activity of SOD was significantly decreased in model rats and the levels of MDA was increased, while pretreatment with the new crystal of puerarin exhibited different improvements in these indices. The results of histopathology showed that pretreatment with the new crystal of puerarin in ISOinduced rats significantly ameliorated the injuries in myocardial tissues. Then the NMR analysis showed that the new crystal of puerarin could effectively inhibit the abnormalities of 11 metabolites in serum and 9 metabolites in cardiac tissues, which were mainly associated with amino acid metabolism, oxidative stress and energy metabolism. CONCLUSION The new crystal of puerarin was effective to treatment MI, which could obviously improve the ISO-induced cardiac hypertrophy. And the potential mechanism was improved the amino acid metabolism disorder, oxidative stress and energy metabolism under MI conditions.