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[摘要]
目的 观察莲房提取物(NRE)对2型糖尿病大鼠胰岛素抵抗(IR)的影响。方法 SD大鼠喂以高脂饲料4周后一次性ip给予小剂量链脲佐菌素(STZ,30 mg/kg),建立2型糖尿病大鼠模型。NRE低、中、高剂量(100、300、500 mg/kg)ig干预5周后,检测大鼠血清空腹血糖(FBG)、胰岛素(FINS)、总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平,检测肝脏丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)和己糖激酶(HK)活性,检测肝糖原和肌糖原水平,检测肝脏丙二醛(MDA)、还原型谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)水平以及血清中瘦素和肿瘤坏死因子-α(TNF-α)水平,并计算胰岛素敏感指数(ISI)和胰岛素抵抗指数(HOMA-IR)。结果 NRE能明显降低模型大鼠FBG值,提高ISI,降低HOMA-IR,降低血清瘦素和TNF-α水平(P<0.05、0.01);对糖尿病大鼠所伴有的血脂(TC、TG、HDL-C、LDL-C)和肝脏(TC、TG、ALT、AST)代谢异常有显著改善作用(P<0.05、0.01);并能提高肝组织GSH水平及抗氧化酶活性,降低MDA水平;此外,NRE可在一定程度上增加糖原的量及HK活性(P<0.05、0.01)。结论 NRE可明显改善2型糖尿病大鼠IR,这可能与其调节血脂和肝脏代谢,提高肝组织抗氧化能力,降低瘦素和TNF-α水平作用有关。
[Key word]
[Abstract]
Objective To study the effects of Nelumbinis Receptaculum (the seedpod of Nelumbo nucifera) extract (NRE) on insulin resistance (IR) in type 2 diabetic rats. Methods The experimental type 2 diabetic rats were established by high-fat diet for 4 weeks and injected with low dose of streptozotocin (STZ, 30 mg/kg). After intervention by ig administration of NRE in low, medium, and high dose groups (100, 300, and 500 mg/kg) for 5 weeks, the effects of NRE on the levels of fasting blood glucose (FBG), fasting insulin (FINS), total cholesterol (TC), triglycerides (TG), high density lipoproteins cholesterol (HDL-C), low density lipoproteins cholesterol (LDL-C), the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hexokinase (HK), the levels of liver glycogen, muscle glycogen, liver malondialdehyde (MDA), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), plasma leptin, and TNF-α were observed. The insulin sensitivity index (ISI) and IR were calculated accordingly. Results NRE could decrease the levels of FBG, increase ISI, reduce the levels of IR, plasma leptin, and TNF-α (P < 0.05 or P < 0.01) in type 2 diabetic rats. The dyslipidemia (TC, TG, HDL-C, and LDL-C) and hepatic metabolism (TC, TG, ALT, and AST) could be improved by NRE (P < 0.05 or P < 0.01). NRE could increase the GSH level and antioxidant enzymes activities, and decrease MDA level. In addition, NRE could increase the glycogens content and HK activity. Conclusion NRE could improve the IR in the experimental type 2 diabetic rats. It might be related to its effects on improving dyslipidemia, hepatic metabolism, and antioxidant capacity of hepatic tissue, as well as reducing leptin and TNF-α levels.
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[基金项目]
国家自然科学基金资助项目(81374048,81102861);国家级大学生创新创业训练计划项目暨浙江省新苗人才计划(2013R410018,2014R410003);浙江省重点科技创新团队项目(2012R10044-02)