北五味子提取物对糖尿病大鼠心肌组织中NOX2和p47phox表达的影响

Effect of Schisandrae Chinensis extracts on expressions of NOX2 and p47phox in myocardium tissue of diabetic rats

目的:探讨北五味子提取物(SCE)对糖尿病大鼠心肌组织中还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶亚单位NOX2和p47phox表达的影响,并阐明其对大鼠心肌的保护作用。方法:选取49只清洁级健康雄性Wistar大鼠采用腹腔单次注射链脲佐菌素(STZ)方法建立糖尿病大鼠模型。45只成模大鼠随机分为模型组(n=12)、低剂量(100 mg·kg^-1)SCE组(n=11)、中剂量(200 mg·kg^-1)SCE组(n=11)和高剂量(400 mg·kg^-1)SCE组(n=11),另取10只Wistar大鼠作为正常对照组。干预12周后麻醉下腹主动脉取血,分离血清,取心脏,称取左心室质量,计算左心室质量指数(LVMI),全自动分析仪检测血清中空腹血糖(FBG)、肌酸激酶(CK)和乳酸脱氢酶(LDH)水平,HE染色观察各组大鼠心肌病理形态表现,比色法测定各组大鼠心肌组织丙二醛(MDA)水平及超氧化物歧化酶(SOD)和谷胱甘肽激酶(GSH)活性,实时荧光定量PCR法检测各组大鼠心肌组织中NOX2和p47phox mRNA表达水平,Western blotting法检测各组大鼠心肌组织中NOX2和p47phox蛋白表达水平。结果:与正常对照组比较,模型组大鼠LVMI增加(P<0.01),心肌细胞排列紊乱,血清中FBG、CK和LDH水平及心肌组织中MDA水平升高(P<0.05或P<0.01),心肌组织中SOD和GSH活性明显降低(P<0.05),而NOX2和p47phox mRNA及蛋白表达水平升高(P<0.01);与模型组比较,不同剂量SCE组大鼠LVMI降低(P<0.05或P<0.01),心肌损伤减轻,血清中FBG、CK和LDH水平及心肌组织中MDA水平降低(P<0.05或P<0.01),心肌组织中SOD和GSH活性升高(P<0.05或P<0.01),NOX2和p47phox mRNA及蛋白表达水平降低(P<0.05或P<0.01),且呈一定的剂量依赖性。结论:SCE可降低糖尿病大鼠FBG水平,抑制心肌NADPH氧化酶表达,降低心肌组织氧化应激水平,该作用可能与其心肌保护作用有关。

Objective:To investigate the effect of Schisandrae Chinensis extracts(SCE)on the expressions of reduced nicotinamide adenine dinucleotide phosphate(NADPH)oxidase subunits NOX2 and p47phox in myocardium tissue of the diabetic rats,and to clarify its protective effect on myocardium of the rats.Methods:Forty-nine clean healthy male Wistar rats were given single intraperitoneal injection of streptozotocin(STZ)to establish the diabetic rat models.Forty-five model rats were randomly divided into model group(n=12),low dose(100 mg·kg^-1)of SCE group(n=1),medium dose(200 mg·kg-1)of SCE group(n=11)and high dose(400 mg·kg^-1)of SCE group(n=11);another 10 rats were selected as normal control group.After 12 weeks of intervention,the blood sample was obtained from abdominal aorta after anesthesia,and the serum was isolated;the heart was obtained and the weight of left ventricle was weighed,and the left ventricular mass index(LVMI)was calculated;the levels of fasting blood glucose(FBG),creatine kinase(CK)and lactate dehydrogenase(LDH)in serum of the rats in various groups were detected by automatic analyzer,the pathological changes of myocardium tissue were observed by HE staining,the levels of malondialdehyde(MDA)and the activities of superoxide dismutase(SOD)and glutathione kinase(GSH)in myocardium tissue were determined by colorimetry,the expression levels of NOX2 mRNA and p47phox mRNA in myocardium tissue of the rats were detected by real-time fluorescence quantitative PCR,and the expression levels of NOX2 and p47phox proteins in myocardium tissue of the rats were detected by Western blotting method.Results:Compared with normal control group,the LVMI of the rats in model group was increased(P<0.01),the arrangement of myocardial cells was disordered,the levels of serum FBG,CK,LDH and MDA in myocardium tissue were increased(P<0.05 or P<0.01),the activities of SOD and GSH in myocardium tissue were decreased(P<0.05),and the expression levels of NOX2 and p47phox mRNA and proteins were increased(P<0.01).Compared with model group,the LVMI of the rats in different doses of SCE groups was decreased(P<0.05 or P<0.01),the myocardial damages were reduced,the levels of serum FBG,CK,LDH and MDA in myocardium tissue were decreased(P<0.05 or P<0.01),the SOD and GSH activities were increased(P<0.05),and the expression levels of NOX2 and p47phox mRNA and proteins were decreased(P<0.05)in a dose-dependent manner.Conclusion:SCE can reduce the FBG level of the diabetic rats,inhibit the expression of NADPH oxidase in myocardium tissue,and reduce the level of oxidative stress in myocardium tissue,which may be related to its myocardial protective effect.