Antidiabetic Properties of 2,5-Dihydroxy-4,3′-Di( β -D-Glucopyranosyloxy)- trans -Stilbene from Mulberry ( Morus bombycis Koidzumi) Root in Streptozotocin-Induced Diabetic Rats

We investigated the antidiabetic properties of 2,5-dihydroxy-4,3-di(β-D-glucopyranosyloxy)-trans-stilbene (DGTS) isolated from Morus bombycis Koidzumi in streptozotocin (STZ)-induced diabetic rats. The DGTS prevented the increase in aspartate aminotransferase, alanine aminotransferase, and blood urea nitrogen levels in serum of diabetic rats. At doses of 200–800 mg/kg, DGTS improved hyperglycemia in the rats, and the hypoglycemic effect of DGTS was comparable to that of tolbutamide. The histological observations showed that DGTS prevented atrophy of pancreatic β-cells and vascular degenerative changes in the islets. DGTS reversed STZ-induced diabetes and had antioxidant activity in assays of FeCl₂/ascorbic acid-induced lipid peroxidation in the rats. Levels of cytochrome P450 2E1 mRNA, as measured by reverse transcription-polymerase chain reaction, were lower in the livers of the DGTS-treated rats than those of the control group. These results suggest that DGTS might be beneficial in the treatment of type 1 diabetes.