香椿叶提取物对II型糖尿病db/db小鼠的降血糖作用研究

Study on the hypoglycemic effect of Toona sinensis Roem leaf extract on type II diabetes mellitus db/db mice

中文关键词:  香椿  糖尿病  胰岛素抵抗  胰岛素受体底物-1

英文关键词:Toona sinensis Roem leaf  diabetes mellitus  insulin resistance  insulin receptor substrate-1

中文摘要:

      目的 研究香椿叶提取物对II型糖尿病db/db模型小鼠的降血糖作用。方法 以自发性II型糖尿病db/db小鼠为模型, 以二甲双胍为阳性药物, 评价香椿叶提取物的降血糖和抗氧化功能。db/db小鼠被随机分为: 模型组、阳性药组[二甲双胍, 50 mg/(kg·BW)]、高剂量香椿叶组[1.0 g/(kg·BW)]、低剂量香椿叶组[0.5 g/(kg·BW)]和安慰剂组, 另设正常组。给药8周后, 检测各组小鼠血浆血糖、糖化血红蛋白(hemoglobin A1c, HbA1c)、血清总胆固醇(total cholesterol, TC)、甘油三酯(triglyceride, TG)、丙二醛(malondialdehyde, MDA)、超氧化物歧化酶(superoxide dismutase, SOD)、肿瘤坏死因子-α (tumor necrosis factor-α, TNF-α)和白细胞介素-1β (interleukin-1β, IL-1β)的水平, 并通过显微镜观察胰腺的组织病理学变化。结果 香椿叶提取物能够显著降低II型糖尿病db/db模型小鼠血糖及炎症因子水平, 并能够改善糖尿病小鼠胰岛纤维化。Western blot分析表明, 香椿叶提取物可通过提高胰岛素受体底物-1 (insulin receptor substrate-1, IRS-1)的磷酸化水平改善胰岛素抵抗而发挥降血糖作用。结论 香椿叶提取物可能通过调控IRS-1的磷酸化水平降低胰岛素抵抗、保护胰岛细胞、延缓胰岛细胞纤维化, 从而发挥降血糖作用, 本研究为香椿叶作为防治高血糖功能性食品的应用开发提供了科学依据。

英文摘要:

      Objective To study the hypoglycemic effect of Toona sinensis Roem leaf extract on type II diabetes mellitus db/db model mice. Methods With spontaneous type II diabetes mellitus db/db mice as the model, metformin as the positive drug, the hypoglycemic and antioxidant functions of Toona sinensis Roem leaf extract were evaluated. The db/db mice were randomly divided into model group, positive drug group [metformin, 50 mg/(kg·BW)], high-dose Toona sinensis Roem group [1.0 g/(kg·BW)], low-dose Toona sinensis Roem group [0.5 g/(kg·BW)] and placebo group, and another normal group. After 8 weeks of administration, the levels of blood glucose in the plasma, hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were detected in the mice of each group, and the histopathological changes of the pancreas were observed through microscope. Results Toona sinensis Roem leaf extract was able to significantly reduce blood glucose and inflammatory factor levels and improve islet fibrosis in diabetic mice. Weston blot analysis showed that Toona sinensis Roem leaf extract could play a hypoglycemic role by increasing the phosphorylation level of insulin receptor substrate-1 (IRS-1) to improve insulin resistance. Conclusion The Toona sinensis Roem leaf extract may reduce insulin resistance, protect pancreatic cells, and delay pancreatic cell fibrosis by regulating the phosphorylation level of IRS-1, thereby exerting a hypoglycemic effect. This study provides scientific basis for the application and development of Toona sinensis Roem leaves as a functional food for preventing and treating hyperglycemia.