Comparison Of Effect And Regulation Mechanisms Of Mulberry Ingredients On Insulin Secretion

The traditional Chinese medicine mulberry has anti-diabetes effect,the previous research showed that mulberry ingredients including 1-deoxynojrimycin(DNJ),resveratrol(RES),oxyresveratrol(OXY),cyanidin-3-glucoside(C3G),and cyanidin-3-rutinoside(C3R)had hypoglycemic effect.Improvement of islet cells is very important.Which of the active ingredients is the dominant factor in improving the secretory function of beta cells?So far,there has been no report on the effects of insulin secretion and apoptosis on islet cells.In this study,we compared the effects of five mulberry ingredients on insulin secretion,apoptosis and its mechanism.The results revealed that 250 ?M H2O2 significantly decreased cell proliferation activity,basal(BIS)and glucose stimulate(GSIS)insulin secretion.Mulberry ingredients had distinct effects on insulin secretion in H2O2-induced MIN6 cells,especially DNJ,C3G and C3R,While RES and OXY showed modest effects in low dose(12.5 ?M).The mechanisms were demonstrated in signal pathway that after treatment with DNJ,C3G and C3R,the expressions of glucokinase(GK)were up-regulated,leading to intracellular ATP accumulation and insulin secretion.They also bound to glucagon like peptide-1 receptor(GLP-1R),improved GLP-1R,duodenal homeobox factor-1(PDX-1)expression and stimulated insulin secretion.Moreover,ROS production,Caspase-3 and Caspase-9 activities were inhibited,followed by decreasing apoptosis rate,while RES and OXY accelerated the apoptosis at high dose(50 ?M).This work expounded the potential mechanisms of mulberry ingredients on antidiabetes,which were attribute to the improvement of secretion ability and inhibition the apoptosis of beta cells.It indicated the potential application in the intervention against hyperglycemia,and promoted the development and utilization of mulberry resources.