Zhu Hong-Yang, Liu Ye, Li Jia-Rong, Liu Yu-Hui, Rong Zi-Ling, Li Yu-Ting, Chang Shi-Yao
Jiangxi University of Chinese Medicine Nanchang 330004, China.
the Second Affiliated Hospital of Nanchang University Nanchang 330008, China.
Zhongguo Zhong Yao Za Zhi. 2023 Sep;48(17):4693-4701. doi: 10.19540/j.cnki.cjcmm.20230418.402.
This study aimed to examine the effect and underlying mechanism of Puerariae Lobatae Radix on insulin resistance in db/db mice with type 2 diabetes mellitus(T2DM) based on the analysis of intestinal flora. Fifty db/db mice were randomly divided into a model group(M group), a metformin group(YX group), a high-dose Puerariae Lobatae Radix group(YGG group), a medium-dose Puerariae Lobatae Radix group(YGZ group), and a low-dose Puerariae Lobatae Radix group(YGD group). Another 10 db/m mice were assigned to the normal group(K group). After continuous administration for eight weeks, body weight and blood sugar of mice were measured. Enzyme linked immunosorbent assay(ELISA) was used to detect glycosylated serum protein(GSP) and fasting serum insulin(FINS), and insulin resistance index(HOMA-IR) was calculated. The histopathological changes in the pancreas were observed by HE staining. Tumor necrosis factor(TNF)-α expression in the pancreas was detected using immunohistochemistry. The structural changes in fecal intestinal flora in the K, M, and YGZ groups were detected by 16S rRNA. Western blot was used to detect the expression of farnesoid X receptor(FXR) and takeda G protein-coupled receptor 5(TGR5) in the ileum, cholesterol 7α-hydroxylase(CYP7A1) and sterol 27α-hydroxylase(CYP27A1) in the liver, and G protein-coupled receptors 41(GPR41) and 43(GPR43) in the colon. Compared with the K group, the M group showed increased body weight, blood sugar, serum GSP, fasting blood glucose(FBG), and FINS, increased HOMA-IR, inflammatory infiltration of islet cells, necrosis and degeneration of massive acinar cells, unclear boundary between islet cells and acinar cells, disturbed intestinal flora, and down-regulated FXR, TGR5, CYP7A1, CYP27A1, GPR41, and GPR43. Compared with the M group, the YX, YGG, YGZ, and YGD groups showed decreased body weight, blood sugar, serum GSP, FBG, and FINS, islet cells with intact and clumpy morphology and clear boundary, necrosis of a few acinar cells, and more visible islet cells. The intestinal flora in the YGZ group changed from phylum to genus levels, and the relative abundance of intestinal flora affecting the metabolites of intestinal flora increased. The protein expression of FXR, TGR5, CYP7A1, CYP27A1, GPR41, and GPR43 increased. The results show that Puerariae Lobatae Radix can improve the inflammatory damage of pancreatic islet cells and reduce insulin resistance in db/db mice with T2DM. The mechanism of action may be related to the increase in the abundance of Actinobacteria, Bifidobacterium, and Bacteroides in the intestinal tract and the protein expression related to metabolites of intestinal flora.
本研究旨在基于肠道菌群分析，探讨葛根对2型糖尿病（T2DM）db/db小鼠胰岛素抵抗的影响及潜在机制。将50只db/db小鼠随机分为模型组（M组）、二甲双胍组（YX组）、高剂量葛根组（YGG组）、中剂量葛根组（YGZ组）和低剂量葛根组（YGD组）。另将10只db/m小鼠分配至正常组（K组）。连续给药八周后，测量小鼠体重和血糖。采用酶联免疫吸附测定（ELISA）法检测糖化血清蛋白（GSP）和空腹血清胰岛素（FINS），并计算胰岛素抵抗指数（HOMA-IR）。通过苏木精-伊红（HE）染色观察胰腺的组织病理学变化。采用免疫组织化学法检测胰腺中肿瘤坏死因子（TNF）-α的表达。通过16S rRNA检测K、M和YGZ组粪便肠道菌群的结构变化。采用蛋白质印迹法检测回肠中法尼醇X受体（FXR）和武田G蛋白偶联受体5（TGR5）、肝脏中胆固醇7α-羟化酶（CYP7A1）和甾醇27α-羟化酶（CYP27A1）以及结肠中G蛋白偶联受体41（GPR41）和43（GPR43）的表达。与K组相比，M组体重、血糖、血清GSP、空腹血糖（FBG）和FINS升高，HOMA-IR升高，胰岛细胞炎性浸润，大量腺泡细胞坏死和变性，胰岛细胞与腺泡细胞界限不清，肠道菌群紊乱，FXR、TGR5、CYP7A1、CYP27A1、GPR41和GPR43表达下调。与M组相比，YX、YGG、YGZ和YGD组体重、血糖、血清GSP、FBG和FINS降低，胰岛细胞形态完整且成团，界限清晰，少数腺泡细胞坏死，胰岛细胞更明显。YGZ组肠道菌群从门水平到属水平发生变化，影响肠道菌群代谢产物的肠道菌群相对丰度增加。FXR、TGR5、CYP7A1、CYP27A1、GPR41和GPR43的蛋白表达增加。结果表明，葛根可改善T2DM db/db小鼠胰岛细胞的炎性损伤并降低胰岛素抵抗。作用机制可能与肠道中放线菌、双歧杆菌和拟杆菌丰度增加以及与肠道菌群代谢产物相关的蛋白表达有关。
