| Objective:In this experiment,the model of AMI in rats was established to observe the regulation of Mongolian medicine Danggong-3 on the expression of Bax,Bcl-2 and Caspase-3 in AMI rats,and to clarify the molecular mechanism of Mongolian medicine Danggong-3 in protecting the myocardium of AMI rats,so as to lay a foundation for further exploring the application of Mongolian medicine Danggong-3 in AMI.Methods:A total of 100 SPF grade SD male rats were raised,and 80 SD rats were randomly selected to establish AMI model by coronary ligation.Fifty rats successfully modeled were randomly divided into Model group(Model),high-dose Danggong-3 group(DG·3-H),medium-dose Danggong-3 group(DG·3-M),low-dose Danggong-3 group(DG·3-L),Fluvastatin group(Fluvastatin),with 10 rats in each group.Another 10 rats were selected as Sham group(Sham),and the remaining 10 rats were left as Blank control(Blank).Each group was intragastric administration of corresponding drugs 24 hours after operation.DG·3-H,DG·3-M and DG·3-L were administrated with 3.80g/kg,1.90g/kg and 0.95 g/kg suspension of Danggong-3,respectively.The Model,Sham and Blank groups were administrated with equal volume of distilled water.Fluvastatin group was administrated with 30 mg/kg fluvastatin every day.The patients were given gavage once a day for 4 weeks.After the experiment,the contents of SOD,CAT,GSH-Px and MDA in myocardial tissue and LDH and CPK in serum were detected by kit.TUNEL method was used to detect the apoptotic index of rat cardiomyocytes.The histopathologic changes of myocardial tissue were observed by HE staining.The m RNA expression levels of Bax,Bcl-2 and Caspase 3 were detected by fluorescence quantitative PCR.The expressions of Bax,Bcl-2 and Caspase 3 were detected by Western blotting.Results:1.SOD,CAT,GSH-Px,MDA in myocardial tissue and LDH and CPK in serum:Compared with Sham,the contents of LDH and CPK in serum of Model group were increased,the activities of SOD,GSH-Px and CAT in myocardial tissue were decreased,and the content of MDA was increased,with statistical significance(P<0.05).Compared with Model,the contents of LDH and CPK in serum in DG·3-H,DG·3-M,DG·3-L and Fluvastatin groups decreased,the activities of SOD,GSH-Px and CAT in myocardial tissue increased,and the content of MDA decreased,with statistical significance(P<0.05).2.Myocardial cell apoptosis index: compared with Sham group,the proportion of myocardial cell apoptosis in Blank group had no significant change(P>0.05),but compared with Model group,the proportion of myocardial cell apoptosis in Model group was significantly increased(P<0.01).Compared with Model group,the number of myocardial cell apoptosis in DG·3-H,DG·3-M and DG·3-L groups was significantly decreased(P<0.01).Compared with DG·3-H group,the proportion of myocardial cell apoptosis in Fluvastatin group had no significant change(P>0.05),and the proportion of myocardial cell apoptosis in DG·3-H group was significantly lower than that in DG·3-M and DG·3-L groups(P<0.01).3.HE staining of myocardial histopathology of rats showed that the myocardial tissue of rats in Sham group and Blank group was complete,the myocardial fibers were arranged neatly,and no inflammatory cell infiltration was observed.The myocardial fibers in Model group were arranged loosely and disordered,some of them were twisted and broken,and there were a lot of inflammatory cell infiltration and other pathological injuries in the interstitium.Compared with Model group,myocardial tissue of DG·3-H,DG·3-M and DG·3-L groups was improved to different degrees,especially in DG·3-H and DG·3-M groups.(Lack of control analysis of western medicine group)4.The m RNA expression levels of Bax,Bcl-2 and Caspase-3 were detected by PCR:there were no differences in the m RNA expressions of Bax,Bcl-2 and Caspase-3 between Sham group and Blank group(P>0.05).Compared with Sham group,the relative expressions of Bax and Caspase-3 m RNA in Model group were significantly increased(P<0.01),while the relative expressions of Bcl-2 m RNA were significantly decreased(P<0.01).Compared with Model group,the relative expressions of Bax and Caspase-3 m RNA in Fluvastatin group and DG·3-H,DG·3-M and DG·3-L groups were significantly decreased(P<0.01),while the relative expressions of Bcl-2 m RNA were significantly increased(P<0.01).Compared with Fluvastatin group,the relative expression of Bax and Caspase-3 m RNA in DG·3-M and DG·3-L groups was higher(P<0.05),while the relative expression of Bcl-2 m RNA was lower(P<0.05).5.Western blotting method was used to detect the expressions of Bax,Bcl-2 and Caspase-3 proteins: Compared with the Blank group,the expressions of Bcl-2,Bax and Caspase-3 proteins in the myocardial tissue of Sham group had no significant changes(P>0.05).Compared with Sham group,Bcl-2 protein expression was significantly decreased in Model group,while Bax and Caspase-3 protein expression was significantly increased(P<0.01).After 4 weeks of continuous gavage with gone-3,compared with Model group,the protein expressions of Bcl-2 in DG·3-H,DG·3-M and DG·3-L groups were significantly increased,while the protein expressions of Bax and Caspase-3 were significantly decreased(P<0.01).Compared with DG·3-M and DG·3-L groups,the protein expression of Bcl-2 in DG·3-H group was significantly increased,while the protein expressions of Bax and Caspase-3 were significantly decreased(P<0.01).Compared with Fluvastatin group,the protein expressions of Bax and Caspase-3 were higher in DG·3-M and DG·3-L groups(P<0.05),while the protein expressions of Bcl-2 were lower in DG·3-M and DG·3-L groups(P<0.05).Conclusion:Mongolian medicine Danggong-3 can effectively reduce the content of MDA in myocardial tissue of AMI rats,increase the activities of SOD,CAT and GSH-Px related enzymes,and reduce the contents of LDH and CPK in serum.This effect may be related to the effect of Danggong-3 on inhibiting excessive oxidative stress in myocardial tissue,reducing the degree of myocardial damage,and protecting myocardial cells.At the same time,Mongolian medicine Danggong-3 can reduce the apoptosis of myocardial cells by down-regulating the expressions of Bax and Caspase-3,and up-regulating the expression of Bcl-2,so as to play a protective role on myocardial cells of AMI rats. |
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