Anti-diabetic effects of water extract and crude polysaccharides from tuberous root of Liriope spicata var. prolifera in mice

Aim of the study: The present study was designed to investigate the hypoglycemic and hypolipidemic effects of the water extract (WE) and crude polysaccharides (CPs) obtained from the tuberous root of Liriope spicata (Thund.) var. prolifera Y. T. Ma, which is widely used in prescriptions of traditional Chinese medicine for the treatment of diabetes mellitus. Materials and methods: WE and CPs were administered orally at different doses (200 and 100 mg/kg body weight) to normal and streptozotocin (STZ)-induced type 2 diabetic male BABL/c mice, respectively. The fasting blood glucose (FBG), lipids and insulin in serum were estimated and an oral glucose tolerance test (OGTT) was performed for the evaluation of hypoglycemic and hypolipidemic effects. Results: Both doses of WE and CPs did not show any appreciable effect on FBG in normal mice. However, they caused a marked decrease of FBG and a significant improvement on glucose tolerance and insulin resistance in STZ-induced type 2 diabetic mice. In addition, while lowering total cholesterol (TC), triglyceride (TG) and low-density lipoprotein (LDL) cholesterol levels, WE and Cps elevated the relative high density lipoprotein (HDL) cholesterol level (HDL/TC) in serum. Compared to WE, the hypoglycemic and hypolipidemic effects of CPs were more marked. Conclusions: The results suggest that WE and CPs may have hypoglycemic and hypolipidemic potential for the type 2 diabetes and support the traditional use of the tuberous root of Liriope spicata var. prolifera as a hypoglycemic agent. (C) 2009 Elsevier Ireland Ltd. All rights reserved.