Oral administration of puerh tea polysaccharides lowers blood glucose levels and enhances antioxidant status in alloxan-induced diabetic mice.

UNLABELLED: The polysaccharides, named puerh tea polysaccharides (PTPS), were isolated from puerh tea. Physicochemical characteristics, hypoglycemic and antioxidant effects of PTPS in alloxan-induced diabetic mice were investigated. PTPS was found to be a kind of acid heteropolysaccharides conjugate, but the physicochemical characteristics of which were different from the polysaccharides from other kinds of teas in literature. Meanwhile, daily administration of PTPS (40 mg/kg BW) could significantly lower the blood glucose levels, which was not different (P > 0.05) from the effects of metformin (15 mg/kg BW) throughout the entire experiment. Furthermore, after 4-wk administration of PTPS (40 mg/kg BW), the superoxide dismutase activity and malondialdehyde contents both in serum and liver were improved to the levels of those in normal mice. In regards to the serum GSH-Px activity, it was even significantly higher (P < 0.05) than that in normal mice, indicating the oxidative stress induced by alloxan could be reversed by administration of PTPS.

PRACTICAL APPLICATION: Control of blood sugar levels and inhibition of oxidative stress are suggested to be important in the treatment of diabetes. In the present work, the effects of the polysaccharides from puerh tea (PTPS) on blood glucose levels and antioxidant status in alloxan-induced diabetic mice were investigated. The information obtained will be valuable for potential application of PTPS in the treatment of diabetes.