Study On The Effect And Mechanism Of Leonurusine Against Myocardial Fibrosis

Objective:To explore the effects and mechanisms of Leonurine on rats with myocardial fibrosis.Methods:1.In vivo studies,we used the rat myocardial fibrosis model established by subcutaneously injection with large dose of Isoprenaline(Iso)induced experimental myocardial fibrosis.After treatment with Leourine(10.0?5.0?2.5mg·kg-1)and positive control drug captopril(4.0mg·kg-1),the degree of myocardial fibrosis in rats were observed by HE staining and Masson staining.And we examined rat heart weight index,left ventricular weight index,the content of hydroxyproline(Hyp),Superoxide dismutase(SOD),malondialdehyde(MDA)in serum,as well as the protein expression of transforming growth factor beta l(TGF-?1),connective tissue growth factor(CTGF)and the phosphorylation of p38 mitogenic activated protein kinase(p38MAPK)in myocardial tissue.2.In vitro studies,Angiotensin ?(Ang ?)was used to induce the proliferation of myocardial fibroblasts(MyoFbs)model.we detected the proliferation of myocardial fibroblasts by MTT,observed the effects of Leonurine on expression of Col ?,Col ? by Elisa,as well as the protein expression of TGF-?1,CTGF by Western blotting(WB).3.In vitro experimental studies,we observed the effects of reactive oxygen species(ROS)scavenger NAC and p38MAPK inhibitor SB203580 on Col I,Col ?,TGF-?1 and CTGF expression by WB.In addition,we analyzed the effects of Leonurine on ROS by flow cytometry,and observed the effects of Leonurine on phosphorylation of p38MAPK by WB.Results:1.In vivo studies,The results showed that there were significant decrease in higher HMI and LVMI,significant increase in serum Hyp and MDA,decrease in SOD found in Iso group,compared with the normal control group.In addition,the results of HE staining and Masson staining showed that the morphology of Iso induced myocardial fibrosis in rats was significantly changed,and the collagen content in myocardial tissue increased significantly.Furthermore,The results of WB showed that the level of p38MAPK phosphorylation in myocardial tissue was significantly increased in Iso model group,as well as the protein expression of TGF-?1 and CTGF increased significantly,compared with normal group;Compared with Iso group,Leonurine groups obviously decreased the HWI and LVWI of rats,reduced serum Hyp and MDA content,and increased the activity of SOD in myocardial fibrosis rats.In addition,the results of WB showed that Leonurine could decrease the phosphorylation of p38MAPK and down-regulate the protein expression of TGF-?1 and CTGF in myocardial tissue of rats.HE staining and Masson staining results also showed that myocardial morphology was improved significantly and collagen concentration in myocardial tissue of rats was reduced after treatment with Leonurine.2.In vitro studies,the results showed that Ang II could significantly increase the proliferation rate of myocardial fibroblasts and the content of Col I,Col?,upregulate the protein expression of TGF-?1 and CTGF,compared with normal group;Compared with Ang II group,Leonurine groups significantly lower the proliferative activity of myocardial fGbroblasts,Leonurine could significantly reduced the secretion of Col ?,Col ?,down-regulate the expression of TGF-?1 and CTGF.3.In vitro experimental studies,the results showed that the protein expression of Col I,Col III,TGF-Pi and CTGF,the content of ROS,and the level of p38MAPK phosphorylation increased significantly in Ang II group.Compared with Ang ?group,NAC and SB203580 could significantly reduce the secretion of Col ?,Col?,down-regulate the expression of TGF-Pi and CTGF.In addition,Leonurine could significantly reduce the content of ROS and down-regulate the expression of p-p38MAPK.Conclusions:1.In this studies,the myocardial fibrosis model successfully induced by Iso.2.Leonurine could improve the morphology of myocardial tissue,reduce the deposition of collagen,decrease the protein expression of TGF-Pi and CTGF,so as to inhibit the Iso-induced myocardial fibrosis,which is related to oxidative stress and the expression of p38MAPK.3.Leonurine could inhibited Ang ?-induced proliferation of myocardial fibroblasts,decrease the collagen content in myocardial fibroblasts down-regulate the expression of TGF-?1 and CTGF,and inhibit the proliferation of myocardial fibroblasts.4.Leonurine could inhibited the proliferation of myocardial fibroblasts,reverse myocardial remodeling,so as to achieve the effect of resisting myocardial fibrosis,The mechanism may be related to the decrease of ROS and the activation of p38MAPK signaling pathway.