| This study was performed to investigate the cardioprotective effect of Schisandra chinensis bee pollen extract(SCBPE)on acute myocardial infarction in rats induced by isoproterenol(ISO)and its potential mechanism,and aimed to provide theory evidences for the development of other function.The main contents and results of this research are summarized as follows:1.The antioxidant activities of SCBPE and its cardioprotective effect against acute myocardial infarction model induced by ISO in rats:the purity of Schisandra chinensis bee pollen grain exceed 90%.Total phenolic acid and total flavonoid contents of SCBPE were 52.92±1.47 GAE mg·g-1 and 30.30±1.09 RE mg·g-1,respectively.IC50 value of DPPH was 44.14 μg/ml.ABTS+· scavenging activity and Ferric-reducing antioxidant power were 0.37±0.01 and 0.33±0.01 TE mM·g-1,respectively.In terms of animal experiment,72 SD rats were randomly allocated into six groups.They were control group,model group,positive group,low dosage group(600 mg·kg-1),middle dosage group(1200 mg·kg-1)and high dosage group(1800 mg·kg-1).All experimental rats were pretreated with SCBPE for 28 days and subcutaneous injected 65 mg·kg-1 ISO for two consecutive days(on 29th and 30th).After anaesthetized and sacrificed,the blood and heart tissue samples were collected.Compared with model group,pretreatment with middle and high dosage of SCPBE significantly reduced the death rate by 16.67%and 25.00%,and the heart and left ventricular mass index were respectively reduced by 14.19%,21.22%and 9.97%,13.62%.Meanwhile,the levels of serum myocardial enzymes(AST,LDH,CK,α-HBDH)also reduced.The activities of SOD,GPX,CAT were elevated in dose-dependent manner,accompanied with the reduction of MDA in heart tissue of middle and high dosage groups.The pathological features of enlarged infarcted area,inflammatory cell infiltration and vascular congestion were observed in model group.However,these microstructure changes were greatly alleviated in middle and high dosage group,which further confirmed the cardioprotective effect of SCBPE.2.The protective mechanism of SCBPE against acute myocardial infarction induced by ISO model in rats:the results of Western Blot showed that,in model group,the expression of Bax,Nrf-2 and HMGB-1 significantly increased,along with the decline expression of Bcl-2 and HO-1.On the contrary,the expression of Nrf-2 was further enhanced,and the expression of Bcl-2 and HO-1 were elevated,but the expression of Bax and HMGB-1 were reduced in middle and high dosage groups.These results indicated that SCBPE was likely through regulating Nrf-2/ARE pathway to enhance the activities of antioxidant system,inhibit proinflammatory protein HMGB-1 and regulated the apoptosis pathway with Bcl-2 and Bax,thereby exert the cardioprotective effect.3.The metabonomics analysis of the cardioprotective effect of SCBPE against acute myocardial infarction induced by ISO in rats:except positive group,the groups of control,middle dosage and high dosage group were obviously differentiated in PCA score plot when compared with model group.And middle dosage and high dosage groups showed recovery tendency toward control group.Score plot of OPLS-DA represented the sharpened differentiation of serum samples in all groups and was employed to screen differential metabolites.23 metabolites including amino acids,sphingosine,arachidonic acid,lyso-phosphatidylcholine and creatine were identified eventually.The results above indicated that SCBPE pretreatment could protected metabolic perturbations in acute myocardial infarction rats,mainly via amino acid metabolism,sphingosine metabolism,lipid metabolism,arachidonic acid metabolism and glycerophosphatide metabolism.In conclusion,SCBPE has protective effect against acute myocardial infarcted induced by ISO,which was likely through the mechanism of Nrf-2/ARE signaling pathway to inhibit inflammatory reaction and apoptosis.Additionally,application of metabonomics analysis dig out differential metabolites,provided another new theoretical basis for the interpretation of protective activities.Furthermore,the positive effect of S.chinensis bee pollen confirmed in this study provided theoretical basis for the potential development and application in the further. |
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