Hypoglycemic and Hypolipidemic Effects of Lycium barbarum Polysaccharide in Diabetic Rats

Objective To study the antidiabetic effects and the underlying molecular mechanisms of Lycium barbarum polysaccharide (LBP) and its DEAE cellulose elution fraction LBP-IV in diabetic rats induced by high fat diet (HFD) and streptozotocin (STZ). Methods After ig administration of LBP-IV [50, 100, and 200 mg/(kg·d)] and LBP [100 mg/(kg?d)] once daily for consecutive 4 weeks to diabetic rats, the glucose and lipids in blood, and mRNA expression of phosphoenolpyruvate carboxykinase (PEPCK), sterol regulatory element binding-protein-1c (SREBP-1c), and fatty acid synthase (FAS) in liver were determined. Results Ig administration of LBP and LBP-IV significantly decreased the levels of blood glucose, HbA1c, TC, TG, and LDL-C, as well as the hepatic mRNA expression of PEPCK, SREBP-1c, and FAS, whereas significantly increased the oral glucose tolerance of diabetic rats. Conclusion Our findings suggest that the antidiabetic effects of LBP and LBP-IV are associated with the decreased hepatic mRNA expression of PEPCK, SREBP-1c, and FAS in HFD-STZ induced diabetic rats.