Department of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, Yanagido, Gifu, Japan.
Mol Nutr Food Res. 2012 Mar;56(3):435-45. doi: 10.1002/mnfr.201100458. Epub 2011 Dec 16.
Recent studies have reported that tiliroside, a glycosidic flavonoid, possesses anti-diabetic activities. In the present study, we investigated the effects of tiliroside on carbohydrate digestion and absorption in the gastrointestinal tract.
This study showed that tiliroside inhibits pancreatic α-amylase (IC₅₀ = 0.28 mM) in vitro. Tiliroside was found as a noncompetitive inhibitor of α-amylase with K(i) values of 84.2 μM. In male ICR mice, the increase in postprandial plasma glucose levels was significantly suppressed in the tiliroside-administered group. Tiliroside treatment also suppressed hyperinsulinemia after starch administration. Tiliroside administration inhibited the increase of plasma glucose levels in an oral glucose tolerance test, but not in an intraperitoneal glucose tolerance test. In human intestinal Caco-2 cells, the addition of tiliroside caused a significant dose-dependent inhibition of glucose uptake. The inhibitory effects of both sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2) inhibitors (phlorizin and phloretin, respectively) on glucose uptake were significantly inhibited in the presence of tiliroside, suggesting that tiliroside inhibited glucose uptake mediated by both SGLT1 and GLUT2.
These findings indicate that the anti-diabetic effects of tiliroside are at least partially mediated through inhibitory effects on carbohydrate digestion and glucose uptake in the gastrointestinal tract.
最近的研究报告称，糖苷类黄酮三叶豆紫檀苷具有抗糖尿病活性。在本研究中，我们研究了三叶豆紫檀苷对胃肠道碳水化合物消化和吸收的影响。
本研究表明，三叶豆紫檀苷在体外抑制胰腺α-淀粉酶（IC₅₀=0.28mM）。三叶豆紫檀苷被发现是α-淀粉酶的非竞争性抑制剂，其 K(i)值为 84.2μM。在雄性 ICR 小鼠中，给予三叶豆紫檀苷后，餐后血浆葡萄糖水平的升高明显受到抑制。三叶豆紫檀苷处理还抑制了淀粉给药后的高胰岛素血症。三叶豆紫檀苷给药抑制口服葡萄糖耐量试验中血糖水平的升高，但不抑制腹腔内葡萄糖耐量试验。在人肠 Caco-2 细胞中，添加三叶豆紫檀苷可显著抑制葡萄糖摄取呈剂量依赖性。在存在三叶豆紫檀苷的情况下，钠依赖性葡萄糖转运蛋白 1（SGLT1）和葡萄糖转运蛋白 2（GLUT2）抑制剂（根皮苷和根皮素）对葡萄糖摄取的抑制作用均显著抑制，表明三叶豆紫檀苷抑制了 SGLT1 和 GLUT2 介导的葡萄糖摄取。
这些发现表明，三叶豆紫檀苷的抗糖尿病作用至少部分是通过抑制胃肠道碳水化合物消化和葡萄糖摄取来介导的。
