金钗石斛多糖对Ⅱ型糖尿病大鼠心肌组织中MMP-1和MMP-9表达的影响

Effects of dendrobium nobile polysaccharides on expression of MMP-1 and MMP-9 in myocardial tissue of type Ⅱ diabetic rats

目的探讨金钗石斛多糖对Ⅱ型糖尿病大鼠心肌损伤的调节作用及其机制,为金钗石斛的开发和糖尿病心肌损伤的治疗提供参考。方法清洁级雄性SD大鼠60只在适应性喂养两周后随机分为正常组、模型组与金钗石斛多糖低、中、高剂量治疗组及阳性药物贝那普利治疗组。采用高脂高糖饮食6个月造模,造模成功后给予相应治疗,治疗结束后处死大鼠。HE染色观察心脏病理学改变,同时检测血糖、胰岛素、心功能指标以及氧化和抗氧化能力指标,实时荧光定量PCR和Western Blot检测其心脏组织中MMP-1和MMP-9的表达。结果全程中正常组大鼠饮食均正常,活泼好动,毛发发白,而模型组则有明显的多饮、多食和多尿症状,金钗石斛多糖对改善上述症状有明显的效果;HE染色正常组心肌排列正常,细胞大小均一,而模型组则有明显的纤维断裂,同时细胞核体积增大,与模型组相比,金钗石斛多糖中剂量组和高剂量组及贝那普利组上述心肌损伤特点均有明显减轻;与正常组相比,模型组血糖、胰岛素抵抗指数、AST、a-HBDH、CTnl、SOD、GSH及T-AOC明显升高,MDA和胰岛素含量明显降低,金钗石斛多糖治疗后,上述指标均有明显改善,特别是氧化和抗氧化能力指标SOD、MDA、GSH以及T-AOC改善最为明显;与正常组相比,模型组MMP-1和MMP-9表达明显降低,金钗石斛多糖组和贝那普利组其表达明显升高,同时金钗石斛多糖中、高剂量组明显高于贝那普利组。结论金钗石斛多糖可以明显改善Ⅱ型糖尿病大鼠受损的心肌细胞,同时改善心功能,其效果优于目前临床中使用的保护心肌药物贝那普利。分析其作用机理,可能与金钗石斛多糖可以提高大鼠抗氧化能力,增加心脏组织中MMP-1和MMP-9的表达有关。

Objective To explore the mechanism of dendrobium nobile polysaccharides on the effection of myocar- dium injury in type 2 diabetic rats, and provide a reference for the development of Dendrobium nobile and further to treat the diabetic myocardium injury. Methods Forty male Sprague-Dawley rats were randomly divided into the normal group, model group and low dose, medium and high dose treatment group and benazepril treatment group. The rats were sacrificed at the end of the treatment. HE staining was used to observe the histopathology of the heart. The blood glu- cose, insulin, cardiac function and oxidative and antioxidant capacity of the rats were measured by kits. The expression of MMP-1 and MMP-9 in heart tissue was detected by real-time quantitative PCR and Western Blot. Results The rats had a normal diet in the normal group, and they were active and hairy, but the model group had obvious symptoms of hyper- pinement and polyuria. Dendrobium nobile polysaccharide had obvious effect on improving the above symptoms. HE stai- ning could found normal in the normal group, while the model group had obvious fibrous rupture, the nucleus volume in-creased. Compared with the model group, Dendrobium nobile polysaccharide middle dose group, high dose group and benazepril group had a significant improvement. The levels of blood glucose, insulin resistance index, AST, a-HBDH, CTnl, SOD, GSH and T-AOC in the model group were significantly higher than those in the normal group （P〈0. 05）. MDA and insulin of Dendrobium nobile polysaccharide middle dose group, high dose group and benazepril group were sig- nificantly higher than those in the normal group （P〈0.05）. The levels of SOD MDA, GSH and T-AOC of Dendrobium nobile polysaccharide middle dose group, high dose group and benazepril group were significantly higher than those of the normal group （P〈0.05）. The levels of MMP-1 and MMP-9 in the model group were significantly higher than those in the normal group （P〈0.05）. The expression MMP-1 and MMP-9 of Dendrobium nobile polysaccharide and benazepril group significantly increased （P〈0.05）. The expression MMP-1 and MMP-9 of Dendrobium nobile polysaccharide high dose group was significantly higher than that of benazepril group（P〈0.05）. Conclusion High fat diet induced to the rats with type 2 diabetes mellitus has a significant myocardial damage and abnormal cardiac function. Dendrobium nobile polysaccharides can significantly improve the functional of damaged. The effect is superior to benazepril. Dendrobium nobile polysaccharide could improve the antioxidant capacity of rats and increase the expression of MMP-1 and MMP-9 in the heart tissue.