Hypoglycemic and hypolipidemic activities of MT-α-glucan and its effect on immune function of diabetic mice

► MT-α-glucan is a new kind of α-glucan purified from fruit body of maitake. ► MT-α-glucan has hypoglycemic and hypolipidemic effect on type 2 diabetes model. ► MT-α-glucan has protective effect on pancreatic β-cell. ► MT-α-glucan could adjust the immunity which has been disrupted in type 2 diabetes. The hypoglycemic and hypolipidemic effect of an α-glucan (designed here as MT-α-glucan) from fruit body of maitake (Grifola frondosa) on diabetic mouse model induced by streptozotocin and high-fat-diet were evaluated, and its effect on immune function of diabetic mice was investigated. Treatment with MT-α-glucan (300 or 100mgkg−1) could decrease the levels of fasting plasma glucose, triglycerides, cholesterol, free fatty acid, the proliferative response of macrophages and IL-1, NO production by macrophages significantly. Treatment with MT-α-glucan could increase the serum insulin, the proliferative response and IL-2 production of splenocytes induced by ConA significantly. Ultrastructural changes of pancreatic β-cells were ameliorated in the treatment group. These data suggest that MT-α-glucan has hypoglycemic and hypolipidemic effect on the diabetic mice model, which might be related to its benefit effect on immune reactions involved in pathogenesis of diabetes mellitus, leading to attenuate the degree of injured β-cells of the pancreatic islets.