School of Food Science and Nutrition, University of Leeds, Leeds, United Kingdom.
Mol Nutr Food Res. 2010 Dec;54(12):1773-80. doi: 10.1002/mnfr.201000019.
The effect of polyphenols, phenolic acids and tannins (PPTs) from strawberry and apple on uptake and apical to basolateral transport of glucose was investigated using Caco-2 intestinal cell monolayers. Substantial inhibition on both uptake and transport was observed by extracts from both strawberry and apple. Using sodium-containing (glucose transporters SGLT1 and GLUT2 both active) and sodium-free (only GLUT2 active) conditions, we show that the inhibition of GLUT2 was greater than that of SGLT1. The extracts were analyzed and some of the constituent PPTs were also tested. Quercetin-3-O-rhamnoside (IC₅₀ =31 μM), phloridzin (IC₅₀=146 μM), and 5-caffeoylquinic acid (IC₅₀=2570 μM) contributed 26, 52 and 12%, respectively, to the inhibitory activity of the apple extract, whereas pelargonidin-3-O-glucoside (IC₅₀=802 μM) contributed 26% to the total inhibition by the strawberry extract. For the strawberry extract, the inhibition of transport was non-competitive based on kinetic analysis, whereas the inhibition of cellular uptake was a mixed-type inhibition, with changes in both V(max) and apparent K(m) . The results in this assay show that some PPTs inhibit glucose transport from the intestinal lumen into cells and also the GLUT2-facilitated exit on the basolateral side.
采用 Caco-2 肠细胞单层模型，研究了草莓和苹果中的多酚、酚酸和单宁（PPTs）对葡萄糖摄取和顶端到基底外侧转运的影响。草莓和苹果的提取物均对摄取和转运有明显的抑制作用。利用含钠（葡萄糖转运蛋白 SGLT1 和 GLUT2 均活跃）和无钠（仅 GLUT2 活跃）条件，我们表明 GLUT2 的抑制作用大于 SGLT1。对提取物进行了分析，并测试了一些组成 PPTs。槲皮素-3-O-鼠李糖苷（IC₅₀=31 μM）、根皮苷（IC₅₀=146 μM）和 5-咖啡酰奎宁酸（IC₅₀=2570 μM）分别对苹果提取物的抑制活性贡献了 26%、52%和 12%，而矢车菊素-3-O-葡萄糖苷（IC₅₀=802 μM）对草莓提取物的总抑制作用贡献了 26%。对于草莓提取物，基于动力学分析，转运的抑制是非竞争性的，而细胞摄取的抑制是混合性抑制，V(max)和表观 K(m)都发生了变化。该测定中的结果表明，一些 PPTs 抑制葡萄糖从肠腔进入细胞的转运，以及 GLUT2 促进的基底外侧侧出。
