To study the hypoglycemic effect and mechanism of guar gum manno-oligosaccharides (GMOS) on streptozotocin-induced diabetic mice.

GMOS was administered to diabetic mice for 6 weeks, and the changes in body mass and insulin resistance were monitored. Furthermore, indicators of glucose and lipid metabolism such as glucose (GLU), insulin (INS), high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C) were determined. Hepatic histopathological changes were observed, and the expression of proteins involved in the adenosine monophosphateactivated protein kinase (AMPK)/peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) signaling pathway and the activity of antioxidant enzymes in the liver were detected.

GMOS effectively relieved the body mass loss of diabetic mice, significantly alleviated glucose tolerance (30.3%) and enhanced insulin sensitivity (34.6%).Compared with the model group, GMOS decreased the levels of GLU, glycosylated serum protein (GSP) and LDL-C by 38.6%, 29.5%, and 27.3%, respectively, and increased the levels of insulin and HDL-C significantly. Moreover, GMOS reduced oxidative damage, activated the AMPK/PGC-1α signaling pathway, and improved the activities of superoxide dismutase (SOD) and catalase (CAT) in the liver.

GMOS could reduce blood glucose and mitigate glucose and lipid metabolism disorder and oxidative stress caused by diabetes mellitus, indicating its potential as a functional food ingredient against diabetes.