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Evidence-Based Complementary and Alternative Medicine
Volume 2013, Article ID 349790, 11 pages
http://dx.doi.org/10.1155/2013/349790
Research Article

Antidiabetic Activity of Polysaccharides from Tuberous Root of Liriope spicata var. prolifera in KKAy Mice

Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji School of Pharmaceutical Sciences, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, China

Received 17 April 2012; Revised 13 March 2013; Accepted 18 April 2013

Academic Editor: Kanokwan Jarukamjorn

Copyright © 2013 Yihui Liu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Tuberous root of Liriope spicata var. prolifera has been widely used as a traditional Chinese medicine for the treatment of diabetes. The present study investigated the antidiabetic effect and the potential mechanisms of two new polysaccharides (LSP1, LSP2) and the total polysaccharides (TLSP), isolated from the tuberous roots. Upon the intragastric administration in obese insulin-resistant diabetic KKAy mice for 28 days, TLSP, LSP1, and LSP2 all caused a remarkable decrease of fasting blood glucose and significant improvement of insulin resistance and serum lipid metabolism in diabetic mice. In addition, liver histological analysis showed that TLSP, LSP1, and LSP2 significantly ameliorated the hepatocyte hypertrophy and decreased the lipid accumulation in the mice liver. Further experiments suggested that TLSP, LSP1, and LSP2 effectively inhibited hepatic gluconeogenesis and increased hepatic glycolysis and hepatic glycogen content. Furthermore, the mechanistic analysis showed the increased expression of insulin-receptor α subunit, insulin-receptor substrate-1, phosphatidylinositol 3-kinase, and peroxisome proliferators-activated receptors γ. These results suggested that TLSP, LSP1, and LSP2 manifest strong antidiabetic activity, therefore hold a great promise for therapeutic application in diabetic therapy and other related metabolic disorders.