Abstract: In this study, SD male rats were employed to establish a diabetic animal model by tail vein injection of streptozotocin in an effort to explore the effect of konjac oligosaccharides (KOS) on blood glucose, serum lipid composition and oxidative stress levels and to clarify the underlying mechanism. The results showed that compared with the diabetic model group, fasting blood glucose, and the serum levels of triglyceride, total cholesterol, and low density lipoprotein were significantly decreased (P < 0.05, P < 0.01), serum high density lipoprotein, total antioxidant capacity and insulin (INS) secretion level were significantly improved in the KOS intervention group (P < 0.05). The analysis of the genes involved in glycolipid metabolism and oxidative stress pathways revealed that the expression levels of glycogen synthesis-related gene glutamine synthetase 2, insulin-induced genes Insig1 and Insig2, oxidative stress-related gene Hmox1 and epidermal growth factor receptor gene were significantly up-regulated (P < 0.05). In contrast, the expression of gluconeogenesis-related gene glucose-6-phosphatase catalytic subunit 1, triglyceride synthesis-related gene, sterol regulatory element binding protein-1, fatty acid synthesis-related genes ACC and FAS, oxidative stress-related genes and insulin-like growth factor binding protein-1 were greatly down-regulated in the KOS intervention group (P < 0.05). We concluded that KOS can regulate blood glucose and glycolipid metabolism, and inhibit oxidative stress induced by diabetes mellitus, and enhance antioxidant capacity in the body.

Key words: konjac oligosaccharides, diabetes, oxidative stress, glycolipid metabolism