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目的研究红芪多糖(HPS)对db/db小鼠糖尿病心肌病心肌纤维化的保护作用机制。方法按照体重将7周龄的雄性db/db小鼠随机分为5组(每组12只):高中低3个剂量实验组(HPS:200,100,50 mg·kg-1)、对照组(罗格列酮:4 mg·kg-1)及模型组(0.9%Na Cl);正常组为12只同周龄的db/m小鼠。连续灌胃8周。于干预前及干预后第2,4,6,8周末,检测血糖;干预第8周末,处死小鼠后分离血清,用生化法检测血脂及心肌组织超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)的活性;以Masson染色观察小鼠心肌组织纤维化程度;用q PCR法、免疫印迹法检测心肌组织过氧化物酶体增殖物激活受体γ(PPARγ)、核转录因子kappa B(NF-κB)mRNA和蛋白的表达。结果模型组、高中2个剂量实验组和对照组的SOD(mg·m L-1)分别为140.70±1.04,145.81±0.99,142.21±1.09,145.70±1.10;这4组的GSH-PX(U·mg-1)分别为110.91±0.82,114.94±0.78,112.10±0.86,114.84±0.86,与模型组比较,实验组与对照组活性显著增强,差异有统计学意义(均P<0.05)。这4组的MDA含量(nmol·mg-1)分别为7.20±0.49,5.82±0.52,6.62±0.67,5.80±0.52,与模型组比较,实验组与对照组活性显著降低,差异有统计学意义(均P<0.05)。模型组、高中低3个剂量实验组及对照组的心肌组织中PPARγmRNA表达分别为0.34±0.11,0.68±0.05,0.48±0.03,0.49±0.03,0.93±0.05;这5组的蛋白表达分别为0.75±0.12,1.78±0.08,1.44±0.07,1.07±0.05,1.63±0.02,与模型组比较,给药组的mRNA和蛋白表达均显著上调,差异有统计学意义(均P<0.05)。模型组、高中2个剂量实验组和对照组的心肌组织中NF-κB mRNA表达分别为3.35±0.81,1.67±0.22,2.34±0.39,2.05±0.44及蛋白表达分别为1.17±0.04,0.56±0.12,0.86±0.13,0.55±0.12,与模型组比较,给药组表达均显著下降,差异有统计学意义(P<0.05)。结论 HPS可能通过增加心肌PPARγ的表达,抑制NF-κB的活性,经PPARγ-NF-κB信号途径来控制氧化应激和炎症反应,从而减轻心肌纤维化的进展。
Objective To study the protective mechanism of Hedysarum Polysaccharide (HPS) on myocardial fibrosis in db / db mice with diabetic cardiomyopathy. Methods Seven-week-old male db / db mice were randomly divided into five groups (12 in each group) according to body weight: high, middle and low dose three groups (HPS: 200,100,50 mg · kg- Glitazone: 4 mg · kg-1) and model group (0.9% Na Cl). The normal group was 12 db / m mice of the same age. Continuous gavage for 8 weeks. Blood glucose was measured before intervention and at the end of the 2nd, 4th, 6th and 8th week after intervention. At the end of the 8th week after intervention, the mice were sacrificed and the serum was separated. The levels of serum lipids and superoxide dismutase (SOD) (MDA) and glutathione peroxidase (GSH-Px). The degree of myocardial fibrosis was observed by Masson staining. The peroxisome proliferations of myocardium were detected by q PCR and Western blotting. Activation of receptor gamma (PPARγ), nuclear factor kappa B (NF-κB) mRNA and protein expression. Results The levels of SOD (mg · m L-1) in experimental group and control group were 140.70 ± 1.04, 145.81 ± 0.99, 142.21 ± 1.09 and 145.70 ± 1.10 respectively in the experimental group and the control group. GSH-PX (U · Mg -1) were 110.91 ± 0.82, 114.94 ± 0.78, 112.10 ± 0.86 and 114.84 ± 0.86, respectively. Compared with the model group, the activity of the experimental group and the control group was significantly increased (all P <0.05). The MDA content (nmol · mg-1) in these four groups were 7.20 ± 0.49, 5.82 ± 0.52, 6.62 ± 0.67 and 5.80 ± 0.52, respectively. Compared with the model group, the activity of the experimental group and the control group was significantly lower, the difference was statistically significant (All P <0.05). The expression of PPARγmRNA in myocardium of model group, high and low middle three dose experimental groups and control group were 0.34 ± 0.11,0.68 ± 0.05,0.48 ± 0.03,0.49 ± 0.03,0.93 ± 0.05 respectively. The protein expressions of these 5 groups were 0.75 ± 0.12,1.78 ± 0.08,1.44 ± 0.07,1.07 ± 0.05,1.63 ± 0.02. Compared with the model group, the mRNA and protein expression in the treatment group were significantly increased (all P <0.05). The expression of NF-κB mRNA in myocardial tissue of experimental group and control group were 3.35 ± 0.81,1.67 ± 0.22,2.34 ± 0.39,2.05 ± 0.44 and protein expression of 1.17 ± 0.04,0.56 ± 0.12 , 0.86 ± 0.13 and 0.55 ± 0.12, respectively. Compared with the model group, the expression of the drug group was significantly decreased, the difference was statistically significant (P <0.05). Conclusion HPS may reduce the myocardial fibrosis by increasing the expression of PPARγ, inhibiting the activity of NF-κB and controlling the oxidative stress and inflammation through PPARγ-NF-κB signaling pathway.