侧柏叶乙酸乙酯提取物缓解小鼠糖尿病心肌病OA北大核心CSTPCD

AIM:To investigate the alleviating effect of ethyl acetate extract from Platycladus orientalis leaves(EAEPOL)on diabetic cardiomyopathy(DCM)and its mechanisms.METHODS:Healthy adult C57BL/6 mice were ran-domly divided into normal control group,DCM group,and EAEPOL group.Cardiac structure and function of the mice were assessed by echocardiography.Myocardial fibrosis was evaluated though myocardial hydroxyproline content determi-nation,myocardial Masson and Sirius red staining,and collagen type I(Col I)and collagen type Ⅲ(Col Ⅲ)immunohis-tochemistry.The degree of myocardial oxidative stress was assessed by measuring malondialdehyde(MDA),superoxide dismutase(SOD)and total antioxidative capacity(T-AOC)levels using kits,as well as detection of nuclear factor E2-re-lated factor-2(Nrf-2)and heme oxygenase-1(HO-1)expression by qRT-PCR and Western blot.Endothelial-mesenchy-mal transition(EndMT)was evaluated by detecting CD31 and α-smooth muscle actin(α-SMA)protein expression by Western blot,and cadherin 5(CDH5)and fibroblast specific protein 1(FSP1)mRNA expression by qRT-PCR,as well as α-SMA immunofluorescence staining.RESULTS:(1)Mouse echocardiography revealed that compared with normal control group,heart rate(HR)and ejection fraction(EF)were significantly reduced in DCM group(P<0.05 or P<0.01),while left ventricular anterior wall thickness at systole and diastole(LVAWs and LVAWd)and left ventricular pos-terior wall thickness at systole and diastole(LVPWs and LVPWd)were significantly increased(P<0.05).Compared with DCM group,the mice in EAEPOL group showed significant increases in HR and EF(P<0.01),and marked decreases in LVAWs,LVAWd,LVPWs and LVPWd(P<0.05).(2)Compared with normal control group,the content of hydroxypro-line in mouse myocardium,the collagen area ratio shown by Sirius red and Masson staining,and the immunohistochemical positive area ratio of Col I and Col Ⅲ in DCM group were significantly increased(P<0.01).Compared with DCM group,the above myocardial fibrosis indicators in EAEPOL group were significantly reduced(P<0.05 or P<0.01).(3)Com-pared with normal control group,the myocardial MDA content and the expression of Nrf-2 in DCM group were significantly increased,while the SOD activity,the T-AOC and the expression of HO-1 was significantly decreased(P<0.01).Com-pared with DCM group,the myocardial MDA content in EAEPOL group was significantly reduced,while the SOD activity,the T-AOC,and the HO-1 and Nrf-2 expression were significantly enhanced(P<0.05 or P<0.01).(4)Compared with normal control group,the myocardial expression of CD31 and CDH5 in DCM group was significantly reduced,the expres-sion of α-SMA and FSP1 was significantly enhanced(P<0.05 or P<0.01),and the α-SMA positive area ratio by immuno-fluorescence staining was also increased(P<0.01).Compared with DCM group,EAEPOL significantly up-regulated the expression of CD31 and CDH5 and down-regulated the expression of α-SMA and FSP1,and the α-SMA positive area ratio by immunofluorescence staining was evidently decreased(P<0.05 or P<0.01).CONCLUSION:EAEPOL may attenuate myocardial fibrosis and improve cardiac function in DCM mice by suppressing oxidative stress and alleviating EndMT.