Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2012, Article ID 678592, 10 pages doi:10.1155/2012/678592 Research Article Citrus ichangensis Peel Extract Exhibits Anti-Metabolic Disorder Effects by the Inhibition of PPARγ and LXR Signaling in High-Fat Diet-Induced C57BL/6 Mouse Xiaobo Ding, 1, 2, 3 Shengjie Fan, 3 Yan Lu, 1, 2, 3 Yu Zhang, 3 Ming Gu, 3 Lu Zhang, 3 Gaigai Liu, 3 Lu Guo, 3 Dong Jiang, 4 Xiong Lu, 5 Yiming Li, 3 Zhiqin Zhou, 1, 2 and Cheng Huang 3 1 College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400716, China 2 Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing 400715, China 3 School of Pharmacy, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China 4 Citrus Research Institute, Chinese Academy of Agricultural Sciences, Chongqing 400712, China 5 Scientific Experimental Center, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China Correspondence should be addressed to Zhiqin Zhou, zzqswu@yahoo.com and Cheng Huang, chuang.shutcm@gmail.com Received 7 October 2012; Accepted 29 November 2012 Academic Editor: Weena Jiratchariyakul Copyright © 2012 Xiaobo Ding 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. Obesity is a common nutritional disorder associated with type 2 diabetes, cardiovascular diseases, dyslipidemia, and certain cancers. In this study, we investigated the effects of Citrus ichangensis peel extract (CIE) in high-fat (HF) diet-induced obesity mice. Female C57BL/6 mice were fed a chow diet or an HF diet alone or supplemented with 1% w/w CIE for 8 weeks. We found that CIE treatment could lower blood glucose level and improve glucose tolerance. In the HF+CIE group, body weight gain, serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) levels, and liver triglyceride (TG) and TC concentrations were significantly (P< 0.05) decreased relative to those in the HF group. To elucidate the mechanism of CIE on the metabolism of glucose and lipid, related genes expression in liver were examined. In liver tissue, CIE significantly decreased the mRNA expression levels of peroxisome proliferator-activated receptor γ (PPARγ) and its target genes, such as fatty acid synthase (FAS) and acyl-CoA oxidase (ACO). Moreover, CIE also decreased the expression of liver X receptor (LXR) α and β which are involved in lipid and glucose metabolism. These results suggest that CIE administration could alleviate obesity and related metabolic disorders in HF diet-induced obesity mice through the inhibition of PPARγ and LXR signaling. 1. Introduction According to World Health Organization (WHO) estimates, there are 1.4 billion overweight adults worldwide and more than 500 million of these are obese [1]. Obesity is one of the most notorious symptoms of metabolic disorders throughout the world. It is considered to be a major risk factor for various chronic diseases, including type 2 diabetes, major cardiovascular diseases, hypertension, dyslipidemia, and certain cancers [2]. At present, only orlistat can be used for long-term weight reduction. However, these drugs are confounded by diminishing response in long-term treatment because of side effects and limited efficacies [3, 4]. Nutritional components may play a prominent role in the prevention and treatment of obesity and related metabolic disorders. Recently, there have been increasing efforts in research for new health-enhancing foods from natural products, and these findings also suggest that nutritional intervention could be an effective and promising strategy to inhibit obesity and obesity-related metabolic diseases [5, 6]. Citrus is one of the most important fruits in the world and is a rich source of nutrients and bioactive compounds. Citrus fruits not only provide ample vitamins, minerals, dietary fibers, and pectins but also provide an abundant of bioactive compounds, including flavonoids, coumarins, limonoids, and carotenoids. Currently, the study of bioactive compounds is one of the most active fields of food and medical science. Many epidemiological and experimental