FOOD SCIENCE ›› 2020, Vol. 41 ›› Issue (1): 183-189.doi: 10.7506/spkx1002-6630-20190606-061

• Nutrition & Hygiene • Previous Articles     Next Articles

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

DING Xiaomeng, HOU Kunyou, HU Xiaoyi, JIA Mengyun, XIE Jianhua, CHEN Yi, YU Qiang   

  1. (State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China)
  • Online:2020-01-15 Published:2020-01-19

Abstract: 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.

Key words: defatted rice bran, microbial fermentation, soluble dietary fiber, reverse transcription real-time quantitative polymerase chain reaction, Caco-2 cells, glucose absorption and transport

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