姜黄素及其类似物H8对糖尿病大鼠心肌损伤的改善

Reduction of myocardial injury in diabetic rats induced by curcumin and its analogue H8

目的探讨姜黄素及其类似物H8改善糖尿病大鼠心肌损伤的作用及机制。方法将50只健康8周龄SPF级雄性SD大鼠随机分为5组,分别为对照组、糖尿病组和3、6 mg/kg H8组及姜黄素(6 mg/kg)组,每组10只。糖尿病组和3、6mg/kg H8组及姜黄素组建立2型糖尿病大鼠模型后,H8组和姜黄素组采用灌胃方式染毒,对照组及糖尿病组均给与等量的1%CMC-Na溶液,染毒容量为2.5 ml/kg,每日1次,连续4周。测定血清中脂蛋白A[lipoprotein A,LP(A)]、总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)、高密度脂蛋白(high-density lipoprotein,HDL)、低密度脂蛋白(lowdensity lipoprotein,LDL)、血糖(glucose,GLU)的水平。采用HE和MASSON染色检测大鼠心肌组织的病理改变及纤维化情况。采用Real-time PCR法检测大鼠心肌组织中心钠肽(ANP)、脑钠肽(BNP)、Bax/Bcl-2、Caspase-3 mRNA的表达水平;采用Western Blot法检测Bax、Bcl-2、Caspase-3的蛋白表达水平。结果与对照组比较,糖尿病组大鼠血清中LP(A)、TC、TG、GLU水平较高,差异有统计学意义(P<0.05);与糖尿病组比较,6 mg/kg H8组血清中TC水平降低,3、6 mg/kg H8组及姜黄素组血清中LP(A)、TG、GLU水平较低,差异有统计学意义(P<0.05)。与对照组比较,糖尿病组心肌细胞排列紊乱,部分心肌细胞变性坏死,且肌间质胶原纤维分布及心肌增生纤维组织积分光密度增加,差异有统计学意义(P<0.05);与糖尿病组比较,3、6 mg/kg H8组及姜黄素组大鼠病理情况及心肌细胞纤维化程度均得到了明显的改善,且心肌增生纤维组织积分光密度减少,差异有统计学意义(P<0.05)。与对照组比较,糖尿病组大鼠心肌组织中ANP、BNP mRNA表达均升高,差异有统计学意义(P<0.05);与糖尿病组比较,3、6 mg/kg H8组及姜黄素组大鼠心肌组织中ANP、BNP mRNA表达均降低,差异有统计学意义(P<0.05)。与对照组比较,糖尿病组大鼠心肌组织中Bcl-2、Bax、Caspase-3的mRNA和蛋白表达水平及Bax/Bcl-2的比值均升高,差异均有统计学意义(P<0.05);与糖尿病组比较,3、6 mg/kg H8组及姜黄素组大鼠心肌组织中Bax、Caspase-3 mRNA和蛋白表达水平及Bax/Bcl-2的比值均降低,差异均有统计学意义(P<0.05)。结论姜黄素及其类似物H8可通过抑制凋亡因子基因和蛋白的表达,改善糖尿病大鼠心肌损伤。

Objective To understand the influence and mechanism of curcumin and its analogue H8 on myocardial injury in diabetic rats.Methods A total of 50 healthy eight-week-old SPF male SD rats were randomly divided into five groups:control group,diabetes group,3,6 mg/kg H8 group and curcumin(6 mg/kg)group,10 rats in each group.After the type 2 diabetic rat models were established in the diabetic group,the 3,6 mg/kg H8 group and the curcumin group,the H8(3,6 mg/kg)group and the curcumin(6 mg/kg)group were administered by gavage,and the control group and the diabetic group were given equal amounts of 1%CMC-Na solution,the exposure volume was 2.5 ml/kg,once a day for four consecutive weeks.Serum lipoprotein A[lipoprotein A,LP(A)],total cholesterol(TC),triglyceride(TG),high-density lipoprotein(HDL),low-density lipoprotein(LDL)and glucose(GLU)levels were determined.Real-time PCR was used to detect the expression of atrial natriuretic peptide(ANP),brain natriuretic peptide(BNP),Bax,Bcl-2,Bax/Bcl-2 and Caspase-3 mRNA in rat myocardial tissue.The protein expressions of Bax,Bcl-2,Bax/Bcl-2 and Caspase-3 were detected by Western blot.Results Compared with the control group,the serum levels of LP(A),TC,TG,and GLU in the diabetic rats were significantly higher(P<0.05);Compared with the diabetic group,the levels of TC in the serum of 6 mg/kg H8 group were lower,the serum levels of LP(A),TG,and GLU in the3 and 6 mg/kg H8 group,and the curcumin(6 mg/kg)group were lower,with significant differences(P<0.05).Compared with the control group,the myocardial cells in the diabetic group were disorderly arranged,and some myocardial cells were degenerated and necrotic,and the distribution of interstitial collagen fibers and integral optical density of myocardial hyperplasia fibers were increased.(P<0.05);Compared with the diabetic group,the pathological conditions and myocardial fibrosis in the 3 and 6 mg/kg H8 groups and the curcumin(6 mg/kg)group were significantly improved,and the integral optical density of myocardial hyperplasia fiber tissue decreased significantly(P<0.05).Compared with the control group,the expressions of ANP and BNP mRNA in the myocardial tissue of the diabetic rats increased significantly(P<0.05);Compared with the diabetic group,the expressions of ANP and BNP mRNA in the myocardial tissue in the 3 and 6 mg/kg H8 groups and the curcumin(6 mg/kg)group decreased with significant differences(P<0.05).Compared with the control group,the mRNA and protein expression levels of Bcl-2,Bax and Caspase-3,and the ratio of Bax/Bcl-2 in myocardial tissue of the diabetic rats increased,with significant differences(P<0.05);Compared with the diabetic group,the expression levels of Bax,Caspase-3 mRNA and protein,and Bax/Bcl-2 ratio in the myocardial tissue in 3 and 6 mg/kg H8 groups and curcumin(6 mg/kg)group were all reduced with significant differences(P<0.05).Conclusion Curcumin and its analogue H8 can reduce myocardial injury in diabetic rats by inhibiting the expression of apoptotic factor genes and proteins.