Effect Of Puerarin On Myocardial Fibrosis In Hypertensive Rats With Diabetes Mellitus

Objective:To explore the effect of puerarin on myocardial fibrosis in diabetic hypertensive rats.Methods:Methods: 8 WKY rats were used as control group,and 16 successful hypertensive rats with diabetes mellitus were randomly divided into model group(n=8)and traditional Chinese medicine group(n=8),puerarin suspension was given to the rats in the traditional Chinese medicine group,and aseptic distilled water was given to the model group and the control group for 12 weeks.After the blood pressure,ultrasonic cardiogram,blood glucose and body weight were measured,all the rats were killed,and their hearts were taken out and weighed,and the whole heart index of rats was calculated.The morphology of left ventricle was observed by HE staining,the content of myocardial collagen fiber was observed by Masson staining,the expression of typeⅠ collagen,type Ⅲ collagen and TGF-β1 was detected by immunohistochemistry,and the protein levels of type Ⅰ collagen,TGF-β1,p-p38 MAPK and p38 MAPK were detected by Western Blot.Results:1 Blood pressure: compared with the control group,the systolic blood pressure increased in the model group(P<0.05),and decreased in the traditional Chinese medicine group compared with the model group(P<0.05).Compared with the control group,the diastolic blood pressure of the model group increased(P<0.05),and compared with the model group,the diastolic blood pressure of the traditional Chinese medicine group decreased(P<0.05).2 Blood glucose: compared with the control group,the blood glucose of the model group increased(P<0.05),and that of the traditional Chinese medicine group decreased compared with the model group(P<0.05).3 Echocardiography: compared with the control group,the ejection fraction(EF)and minor axis shortening rate(FS)in the model group decreased(P<0.05),while the ejection fraction(EF)and minor axis shortening rate(FS)increased in the traditional Chinese medicine group compared with the model group(P<0.05).4 Heart mass index: compared with the control group,the heart mass index of the model group increased(P<0.05),and that of the traditional Chinese medicine group decreased compared with the model group(P<0.05).5 HE staining: the myocardial tissue of the control group was arranged neatly,the boundary was clear,and the shape was regular;compared with the control group,the myocardial tissue of the model group was disordered,obviously broken and the boundary was unclear.Compared with the model group,the cardiomyocytes in the traditional Chinese medicine group were relatively neatly arranged,more regular in shape and less broken.6 Masson staining: the myocardial tissue of the control group was arranged neatly,the gap between the myocardial muscle bundles was smaller,and the myocardial collagen fibers were evenly distributed and less;compared with the control group,the myocardial tissue of the model group was disordered,the myocardial muscle bundle space was significantly increased,and the collagen fibers were significantly increased and aggregated;compared with the model group,the myocardial muscle bundle space of the traditional Chinese medicine group became smaller and the collagen fibers decreased significantly.The area percentage of collagen fiber: compared with the control group,the area of collagen fiber in the model group increased(P<0.05),and that in the traditional Chinese medicine group decreased compared with the model group(P<0.05).7 Bitter Sirius red staining: the shape of myocardial collagen fibers in the control group was normal,neatly arranged,and the boundary was clear;compared with the control group,the distribution of myocardial collagen fibers in the model group increased,arranged disorderly,irregular;compared with the model group,the content of myocardial collagen fiber in the traditional Chinese medicine group decreased.8 Immunohistochemistry: the results showed that the expression of type Ⅰcollagen fiber and type Ⅲ collagen fiber in the model group was higher than that in the control group(P<0.05),and that in the traditional Chinese medicine group was lower than that in the model group(P<0.05).Compared with the control group,the expression of TGF-β1 in the model group increased(P<0.05),while the expression of TGF-β1 decreased in the traditional Chinese medicine group(P<0.05).9 Compared with the control group,the content of collagen Ⅰ protein in the model group increased(P<0.05),while that in the traditional Chinese medicine group decreased(P<0.05).Compared with the control group,the content of TGF-β1 protein in the model group increased,while the content of TGF-β1 protein in the traditional Chinese medicine group decreased compared with the model group.Compared with the control group,the ratio of p-p38MAPK/p38 MAPK and the level of p38 MAPK phosphorylation in the model group increased(P<0.05),while the ratio of p-p38MAPK/p38 MAPK and the level of p38 MAPK phosphorylation in the traditional Chinese medicine group decreased(P<0.05).Conclusion:Puerarin can reduce blood pressure and blood glucose level,improve cardiac function and inhibit myocardial fibrosis in hypertensive rats with diabetes mellitus.Its mechanism may be related to the inhibition of TGF-β1,the inhibition of p38 MAPK signal pathway and the reduction of type Ⅰ and Ⅲcollagen deposition.