脱脂米糠可溶性膳食纤维对小肠葡萄糖吸收和转运的影响及其作用机制  

Effect of Soluble Dietary Fiber from Defatted Rice Bran on Glucose Absorption and Transport in Small Intestine and Its Mechanism of Action

作　　者：丁晓萌 侯坤友 胡晓祎 贾梦云 谢建华[1] 陈奕[1] 余强[1] DING Xiaomeng;HOU Kunyou;HU Xiaoyi;JIA Mengyun;XIE Jianhua;CHEN Yi;YU Qiang(State Key Laboratory of Food Science and Technology,Nanchang University,Nanchang 330047,China)

机构地区：[1]南昌大学食品科学与技术国家重点实验室

出　　处：《食品科学》2020年第1期183-189,共7页Food Science

基　　金：江西省重点研发计划项目（20171BBF60041）;国家自然科学基金青年科学基金项目（31701603）;国家自然科学基金面上项目（31972066）

摘　　要：目的:探讨绿色木霉发酵法制备的脱脂米糠可溶性膳食纤维(soluble dietary fiber from defatted rice bran,DRB-SDF)对小肠葡萄糖吸收和转运的影响及其作用机制。方法:以Caco-2细胞为研究对象,分别建立葡萄糖吸收和转运模型,设置正常组、阳性阿卡波糖对照组(25μg/mL)以及DRB-SDF低、中、高(2、4、8 mg/mL)剂量组。在DRB-SDF作用一定时间后,采用CCK-8法检测Caco-2细胞活力、氧化酶-偶联比色法检测葡萄糖质量浓度、酶活力检测试剂盒测定α-葡萄糖苷酶活力、逆转录实时荧光定量聚合酶链式反应测定α-葡萄糖苷酶以及SGLT-1、GLUT-2和Na^+-K^+-ATP酶mRNA的表达水平。结果:DRB-SDF质量浓度小于8 mg/mL时对Caco-2细胞增殖未产生显著影响。相比于正常组,DRB-SDF低、中、高剂量组葡萄糖吸收和转运水平均被抑制,并呈浓度依赖性。DRB-SDF作用后,Caco-2细胞α-葡萄糖苷酶活力明显被抑制,同时α-葡萄糖苷酶、SGLT-1、GLUT-2和Na^+-K^+-ATP酶mRNA的表达水平均显著下降(P<0.05)。结论:DRB-SDF可能通过抑制α-葡萄糖苷酶活性,降低小肠上皮细胞葡萄糖转运载体蛋白SGLT-1、GLUT-2和Na^+-K^+-ATP酶mRNA的表达,抑制碳水化合物水解,占据葡萄糖的吸收位点等途径,延缓小肠葡萄糖的吸收和转运,最终降低餐后高血糖。Objective: To investigate the effect of soluble dietary fiber from defatted rice bran(DRB-SDF) prepared by Trichoderma viride fermentation on glucose absorption and transport in the small intestine and to ascertain its mechanism of action. Methods: Using Caco-2 cells in vitro, glucose absorption and transport in small intestine were simulated and evaluated in the presence of different concentrations of DRB-SDF(2, 4 and 8 mg/mL). Acarbose(25 μg/mL) was served as a positive control and cells without any treatment were used as a normal control. The effect of DRB-SDF on the proliferation and viability of Caco-2 cells was detected by CCK-8 assay. Glucose concentration in the absorption and transport models was determined using a glucose test kit. Alpha-glucosidase activity was determined using an enzyme assay kit. The mRNA expression of α-glucosidase, SGLT-1, GLUT-2 and Na^+-K^+-ATPase was examined by reverse transcription real-time quantitative polymerase chain reaction(qPCR). Results: The proliferation of Caco-2 cells was not significantly affected when the concentration of DRB-SDF was less than 8 mg/mL. Compared with the normal control, the level of glucose absorption and transport in the DRB-SDF-treated groups was inhibited in a concentration-dependent way. The activity of α-glucosidase in Caco-2 cells was significantly inhibited after treatment with DRB-SDF, and the expression levels of α-glucosidase, SGLT-1, GLUT-2 and Na^+-K^+-ATPase mRNA were significantly decreased. Conclusion: DRB-SDF can delay the absorption and transport of glucose in the small intestine possibly by inhibiting α-glucosidase activity, decreasing the expression of glucose transporter proteins such as SGLT-1, GLUT-2 and Na^+-K^+-ATPase in intestinal epithelial cells, inhibiting carbohydrate hydrolysis, and occupying glucose absorption sites, and ultimately reducing postprandial hyperglycemia.

关 键 词：脱脂米糠 微生物发酵 可溶性膳食纤维 逆转录实时荧光定量聚合酶链式反应 CACO-2细胞 葡萄糖吸收和转运 

分 类 号：R151.1[医药卫生—营养与食品卫生学]