Zhang Yu, Zhang Hui, Wang Li, Qian Haifeng, Qi Xiguang, Ding Xiangli, Hu Bo, Li Jiajia
Jiangnan University, State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
Jiangnan University, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
J Sci Food Agric. 2016 Jan 30;96(2):484-91. doi: 10.1002/jsfa.7114. Epub 2015 Feb 26.
Many previous studies have reported the role of oat β-glucan (OBG) in the reduction of postprandial glucose, and hypothesised that OBG may form a protective layer along the intestinal wall, acting as a viscous barrier to decrease glucose transportation. This study examined whether the molecular weight (MW) and concentration of OBG affected the diffusion of glucose in vitro. The effect of OBG on glucose transportation in vitro and sodium-potassium adenosine triphosphatase (Na(+)/K(+)-ATPase) activity in the everted small intestines of normal rats was also examined.
In vitro, higher MWs and concentrations of OBG increased the inhibitory effects on glucose diffusion and glucose adsorption. The transport of glucose by glucose transporters and Na(+)/K(+)-ATPase activity in the small intestinal mucosa of rats were significantly lower following the addition of OBG than those in the absence of OBG at the same time-points throughout glucose transportation (P < 0.05). In the OBG-treated group, the Na(+)/K(+)-ATPase activity decreased with increasing OBG MW. However, as the concentration of OBG in the solution increased, the Na(+)/K(+)-ATPase activity in the small intestine increased due to stronger gastrointestinal motility. We also found that higher MWs of OBG had a greater inhibitory effect on intestinal disaccharidase activities in vitro.
Oat β-glucan is able to adsorb glucose molecules, inhibit glucose transport, decrease the concentration of available glucose and suppress disaccharidase activities in the small intestine.
此前许多研究报道了燕麦β-葡聚糖（OBG）在降低餐后血糖方面的作用，并推测OBG可能沿肠壁形成一层保护层，作为一种粘性屏障来减少葡萄糖转运。本研究检测了OBG的分子量（MW）和浓度是否会在体外影响葡萄糖的扩散。还检测了OBG对体外葡萄糖转运以及正常大鼠外翻小肠中钠钾腺苷三磷酸酶（Na(+)/K(+)-ATP酶）活性的影响。
在体外，较高分子量和浓度的OBG增强了对葡萄糖扩散和葡萄糖吸附的抑制作用。在整个葡萄糖转运过程中的同一时间点，添加OBG后大鼠小肠黏膜中葡萄糖转运蛋白介导的葡萄糖转运以及Na(+)/K(+)-ATP酶活性均显著低于未添加OBG时（P < 0.05）。在OBG处理组中，Na(+)/K(+)-ATP酶活性随OBG分子量增加而降低。然而，随着溶液中OBG浓度的增加，由于胃肠蠕动增强，小肠中的Na(+)/K(+)-ATP酶活性增加。我们还发现，较高分子量的OBG在体外对肠双糖酶活性的抑制作用更强。
燕麦β-葡聚糖能够吸附葡萄糖分子，抑制葡萄糖转运，降低可利用葡萄糖的浓度，并抑制小肠中的双糖酶活性。
