Resistant dextrin improves insulin resistance in db/db mice by enhancing insulin signaling pathway / 上海交通大学学报（医学版）

ABSTRACT

Objective: To investigate the effect of resistant dextrin on insulin resistance in db/db mice and preliminarily explore potential molecular mechanisms. Methods: Ten 8-week-old db/db mice were randomly assigned into two groups, i.e., control group and resistant dextrin group, which were administered with distilled water and resistant dextrin by gavage for 9 weeks, respectively. Fasting blood glucose (FBG) and body weight were measured every week. Intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) were performed separately at the 8th and 9th week. Fasting serum insulin (FINS) was measured, homeostasis model assessment insulin resistance (HOMA-IR) index was calculated, and triacylglycerol (TAG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-Ch), high density lipoprotein-cholesterol (HDL-Ch) were detected after the mice were sacrificed. The relative expression of Ir, Irs-1, Pi3k, Akt, and Glut-2 in insulin signaling pathways in the liver was determined by real-time quantitative PCR. The expression of IRS-1, p-AKT, GLUT-2 in the liver were determined by Western blotting. Results: After 9 weeks of treatment with resistant dextrin, the body weight of the resistant dextrin group decreased, but the difference was not statistically significant (P=0.384); FINS decreased, and HOMA-IR index significantly decreased (P=0.032); insulin resistance was significantly improved (all P<0.05); the blood biochemical parameters, including TAG, TC, LDL-Ch, and HDL-Ch were lower, but only LDL-Ch was statistically different (P=0.034); the expression of Ir, Irs-1, Akt, and Glut-2 mRNA in the liver significantly increased (all P<0.05); the expression of IRS-1 and GLUT-2 proteins also significantly increased (P=0.026, P=0.039). Conclusion: Resistant dextrin may improve insulin resistance in db/db mice by enhancing insulin signaling pathway.