葛根素激活GLP-1R通路改善高脂诱导的HFD小鼠高血糖水平
Puerarin Ameliorates Hyperglycemia in HFD Mice Dependent on Activation of GLP-1R Signaling Pathway
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摘要: 目的 探讨葛根素对高脂诱导的HFD小鼠高血糖水平的影响以及GLP-1R通路在葛根素降糖功效中的作用。方法 以高脂诱导的HFD(High-fat-diet)糖尿病小鼠模型为对象,采用GLP-1受体拮抗剂Exendin 9-39(Ex 9-39)用以阻断GLP-1R通路的激活,通过动物体内实验进一步评价GLP-1R通路在葛根素降糖功效中的作用。结果 葛根素能够有效降低HFD小鼠血糖水平并改善HFD小鼠口服葡萄糖耐受能力,而Ex 9-39显著抑制葛根素的降糖作用,并且葛根素促进小鼠胰岛素分泌的作用也被Ex 9-39所阻断。通过小鼠胰腺组织切片免疫荧光染色检测观察到,葛根素能够增加HFD小鼠胰岛β细胞中ki67的表达,提示其能够促进胰岛β细胞增殖,当Ex 9-39阻断GLP-1R通路激活时,葛根素的作用被抑制。结论 本研究首次在糖尿病小鼠模型中,证实葛根素降糖及改善胰岛β细胞生存的作用依赖于GLP-1R通路的激活,为今后葛根降糖的潜在开发应用奠定实验基础。Abstract: OBJECTIVE To investigate the effect of puerarin on hyperglycemia in HFD mice and the role of GLP-1R signaling in modulating the hypoglycemic effect of puerarin. METHODS HFD induced diabetic mice was used as the subject, GLP-1 receptor antagonist Exendin 9-39 (Ex 9-39) was used to block the activation of GLP-1R signaling, and in vivo experiments were performed to further evaluate the role of GLP-1R signaling in the hypoglycemic effect of puerarin. RESULTS The glucose homeostasis and the OGTT (oral glucose tolerance tests) of HFD mice were both improved by puerarin, while the effect was impaired by Ex 9-39 significantly. Moreover, puerarin increased serum insulin contents in HFD mice, but such effect was blocked by Ex 9-39 as well. Elevated expression of ki67 in β-cells was observed in pancreatic sections from HFD mice pre-treated with puerarin using Ki-67/insulin immunostaining, suggesting that puerarin could promote β-cell proliferation. The puerarin effect was inhibited when the GLP-1R signaling activation was blocked by Ex9-39. CONCLUSION The results confirmed that the activation of GLP-1R signaling was critical for the anti-diabetic effects of puerarin on HFD induced diabetic mice. Our finding highlights the potential value of Radix puerariae as a dietary supplement for diabetes care.