Antidiabetic Effect of an Active Components Group from Ilex kudingcha and Its Chemical Composition

Evidence-Based Complementary and Alternative Medicine, Mar 2012

The leaves of Ilex kudingcha are used as an ethnomedicine in the treatment of symptoms related with diabetes mellitus and obesity throughout the centuries in China. The present study investigated the antidiabetic activities of an active components group (ACG) obtained from Ilex kudingcha in alloxan-induced type 2 diabetic mice. ACG significantly reduced the elevated levels of serum glycaemic and lipids in type 2 diabetic mice. 3-Hydroxy-3-methylglutaryl coenzyme A reductase and glucokinase were upregulated significantly, while fatty acid synthetase, glucose-6-phosphatase catalytic enzyme was downregulated in diabetic mice after treatment of ACG. These findings clearly provided evidences regarding the antidiabetic potentials of ACG from Ilex kudingcha. Using LC-DAD/HR-ESI-TOF-MS, six major components were identified in ACG. They are three dicaffeoylquinic acids that have been reported previously, and three new triterpenoid saponins, which were the first time to be identified in Ilex kudingcha. It is reasonable to assume that antidiabetic activity of Ilex kudingcha against hyperglycemia resulted from these six major components. Also, synergistic effects among their compounds may exist in the antidiabetic activity of Ilex kudingcha.

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Antidiabetic Effect of an Active Components Group from Ilex kudingcha and Its Chemical Composition

Antidiabetic Effect of an Active Components Group from Ilex kudingcha and Its Chemical Composition Chengwu Song, Chao Xie, Zhiwen Zhou, Shanggong Yu, and Nianbai Fang Key Laboratory of Chinese Medicine Resource and Compound Prescription, Hubei University of Chinese Medicine, Ministry of Education, 1 Huang-jia-hu, Wuhan 430065, China Received 31 August 2011; Revised 21 November 2011; Accepted 22 November 2011 Academic Editor: Ching Liang Hsieh Copyright © 2012 Chengwu Song 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 The leaves of Ilex kudingcha are used as an ethnomedicine in the treatment of symptoms related with diabetes mellitus and obesity throughout the centuries in China. The present study investigated the antidiabetic activities of an active components group (ACG) obtained from Ilex kudingcha in alloxan-induced type 2 diabetic mice. ACG significantly reduced the elevated levels of serum glycaemic and lipids in type 2 diabetic mice. 3-Hydroxy-3-methylglutaryl coenzyme A reductase and glucokinase were upregulated significantly, while fatty acid synthetase, glucose-6-phosphatase catalytic enzyme was downregulated in diabetic mice after treatment of ACG. These findings clearly provided evidences regarding the antidiabetic potentials of ACG from Ilex kudingcha. Using LC-DAD/HR-ESI-TOF-MS, six major components were identified in ACG. They are three dicaffeoylquinic acids that have been reported previously, and three new triterpenoid saponins, which were the first time to be identified in Ilex kudingcha. It is reasonable to assume that antidiabetic activity of Ilex kudingcha against hyperglycemia resulted from these six major components. Also, synergistic effects among their compounds may exist in the antidiabetic activity of Ilex kudingcha. 1. Introduction Diabetes mellitus is one of the most common chronic and systemic diseases in the world. The World Health Organization estimated that diabetes is responsible for approximately 5% of all deaths worldwide and predicted a >50% increase in diabetes-related mortality in 10 years [1]. Dietary restrictions, exercise, and administration of oral glucose-lowering agents are applied widely to control blood glucose concentrations as tightly as possible [2]. Moreover, herbal supplements and other alternative medicines have gradually increased to be used for treatment of diabetic disorders. Kudingcha is the leaves of Ilex kudingcha C. J. Tseng (Aquifoliaceae), and a folk medicine for therapy of diabetes in China. Also, the Ilex kudingcha have been report to possess antioxidative, hypotensive, antiobesity and antidiabetic activities and contain saponin, polyphenol, and flavones [3–6]. However, there is a lack of reliable data about bioactive components (ACG of Ilex kudingcha) for its antiobesity and antidiabetic activities and the effect of ACG on diabetes and obesity. The present study focused on the effectiveness of ACG on type 2 diabetic mice induced by alloxan. The physiologic and biochemical changes that resulted from ACG treatment were examined. Also, the expression levels of the genes related to glycemia and lipids metabolism were investigated to elucidate the antidiabetic potentials of ACG on type 2 diabetes. Furthermore, a series of LC-DAD/HR-ESI-TOF-MS analyses were carried out to identify the structures of the components present in ACG. 2. Materials and Methods2.1. Drugs and Chemicals The leaves of Ilex kudingcha, which grown in Hainan area of China, was obtained from Xianning Kang Jin Chinese Herbal Pieces Co., Ltd. (Hubei, China). The leaves of Ilex kudingcha were identified and authenticated by the taxonomist of Key Laboratory of Chinese Medicine Resource and Compound Prescription (Hubei University of Chinese Medicine), Ministry of Education. A voucher specimen (No. 020) was deposited in herbarium of the Key Laboratory. Alloxan was purchased from Sigma Ltd. (USA). Phenformin was obtained from Merck Sharp pharmaceutical Ltd. (Beijing, China). Cholesterol, triglyceride, blood glucose, superoxide dismutase, malondialdehyde, and nonesterified fatty acid assay kits were purchased from Shanghai Mind Bioengineering Co. Ltd. (Shanghai, China). 2.2. Fractionation of the Extract from Ilex Kudingcha Four kilograms of Ilex kudingcha were boiled in 40 L distilled water for 3 h, and this extraction process was repeated for 3 times. The four extracts were combined and concentrated on a rotary evaporator under reduced pressure followed by drying in a freeze dryer. The lyophilized powder of water extract from Ilex kudingcha was extracted with 20-fold (w/v) 100% MeOH at 65°C for 3 h and the extraction was repeated for 3 times. The combined 100% MeOH extract was evaporated and dried by a freeze dryer to yield fraction A. The residue was then extracted with 50% MeOH/H2O, using same e (...truncated)


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Chengwu Song, Chao Xie, Zhiwen Zhou, Shanggong Yu, Nianbai Fang. Antidiabetic Effect of an Active Components Group from Ilex kudingcha and Its Chemical Composition, Evidence-Based Complementary and Alternative Medicine, 2012, 2012, DOI: 10.1155/2012/423690