目的 探究黑树莓多酚对糖尿病小鼠血糖代谢的调控作用及其作用机制。方法 分别以链脲佐菌素和四氧嘧啶诱导小鼠建立糖尿病模型，给予含黑树莓多酚的饲料喂养，检测各组小鼠血糖；采用试剂盒检测各组小鼠血清中三酰甘油（triglyceride，TG）和总胆固醇（cholesterol，CHO）水平；考察黑树莓多酚对糖尿病小鼠脏器指数的影响；采用qRT-PCR法考察黑树莓多酚对糖尿病小鼠肝脏中白细胞介素-1（interleukin-1，IL-1）、IL-6、环氧合酶2（cyclooxygenase 2，COX2）和肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）mRNA和骨骼肌中葡萄糖转运蛋白4（glucose transporter 4，GLUT4）和AMP激活蛋白激酶α1（AMP-activated protein kinase α1，AMPKα1）mRNA表达的影响；采用Western blotting法检测黑树莓多酚对糖尿病小鼠骨骼肌中胰岛素信号通路相关蛋白表达的影响。结果 黑树莓多酚显著降低链脲佐菌素和四氧嘧啶诱导的糖尿病小鼠空腹血糖和糖耐量（P<0.05、0.01），显著降低四氧嘧啶诱导的糖尿病小鼠血清中TG和CHO水平（P<0.05），显著降低四氧嘧啶诱导的糖尿病小鼠肾脏指数（P<0.05），显著降低四氧嘧啶诱导的糖尿病小鼠肝脏中IL-1、IL-6、COX2和TNF-α mRNA表达水平（P<0.05、0.01）；显著上调链脲佐菌素诱导的糖尿病小鼠骨骼肌中磷酸化胰岛素受体底物（phosphorylated insulin receptor substrate，p-IRS）、胰岛素受体（insulin receptor，IR）、磷酸化IR（p-IR）和磷酸化蛋白激酶B（phosphorylated protein kinase B，p-Akt）蛋白表达水平（P<0.05、0.01），显著上调骨骼肌GLUT4 mRNA表达水平（P<0.05）；显著上调四氧嘧啶诱导的糖尿病小鼠骨骼肌中p-IRS、IR、p-IR和糖原合成酶激酶3β（glycogen synthase kinase 3β，GSK3β）蛋白表达水平（P<0.05），显著上调骨骼肌GLUT4及AMPKα1 mRNA表达水平（P<0.05、0.01）。结论 黑树莓多酚可以通过激活胰岛素信号通路并促进葡萄糖代谢，从而缓解链脲佐菌素以及四氧嘧啶诱导的糖尿病小鼠中血糖代谢紊乱引发的相关症状。

Objective To explore the blood sugar regulation and mechanism of polyphenol from Rubus occidentalis on blood sugar in diabetic mice. Methods Diabetes models induced by streptozotocin and alloxan were established in mice, after fed with feed containing polyphenol from R. occidentalis, blood glucose of mice in each group were detected; Kit was used to detect levels of triglyceride (TG) and total cholesterol (CHO) in serum of mice in each group; The effect of polyphenol from R. occidentalis on organ index of diabetic mice were investigated; qRT-PCR method was used to investigate the effect of polyphenol from R. occidentalis on interleukin-1 (IL-1), IL-6, cyclooxygenase 2 (COX2), tumor necrosis factor-α (TNF-α) mRNA expressions in liver and glucose transporter 4 (GLUT4), AMP-activated protein kinase α1 (AMPKα1) mRNA expressions in skeletal muscle of diabetic mice; Western blotting was used to detect the effect of polyphenol from R. occidentalis on expression of insulin signaling pathway-related proteins in skeletal muscle of diabetic mice. Results Polyphenol from R. occidentalis significantly reduced fasting blood glucose and glucose tolerance in diabetic mice induced by streptozotocin and alloxan (P < 0.05, 0.01), reduced levels of TG and CHO in serum of diabetic mice induced by alloxan (P < 0.05), reduced the kidney index of diabetic mice induced by alloxan (P < 0.05), reduced IL-1, IL-6, COX2 and TNF-α mRNA expressions in liver of diabetic mice induced by alloxan (P < 0.05, 0.01), up-regulated phosphorylated insulin receptor substrate (p-IRS), insulin receptor (IR), phosphorylated IR (p-IR) and phosphorylated protein kinase B (p-Akt) expressions in skeletal muscle of diabetic mice induced by streptozotocin (P < 0.05, 0.01), up-regulated GLUT4 mRNA expression levels (P < 0.05), up-regulated p-IRS, IR, p-IR and glycogen synthase kinase 3β (GSK3β) expressions in skeletal muscle of diabetic mice induced by alloxan (P < 0.05), and up-regulated GLUT4 and AMPKα1 mRNA expressions (P < 0.05, 0.01). Conclusion Polyphenol from R. occidentalis can alleviate the symptoms caused by disorders of blood glucose metabolism in diabetic mice induced by streptozotocin and alloxan through activating the insulin signaling pathway and promoting glucose metabolism.

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