97 Pakistan Veterinary Journal ISSN: 0253-8318 (PRINT), 2074-7764 (ONLINE) Accessible at: www.pvj.com.pk Effects of Dietary β-Glucan on Serum Lipids and Performance Indices in Rats Fed a Diet Enriched with Cholesterol Tanay Bilal*, Feraye Esen Gursel 1 , Atila Ates 1 and Onur Keser Department of Animal Nutrition and Nutritional Diseases, 1 Department of Biochemistry, Faculty of Veterinary Medicine, Istanbul University, 34320 Avcilar, Istanbul, Turkey *Corresponding author: tanbilal@istanbul.edu.tr ARTICLE HISTORY ABSTRACT Received: Revised: Accepted: July 04, 2011 August 15, 2011 August 17, 2011 Key words: β-glucan Cholesterol Hypercholesterolemic rat Lipoprotein The aims of this study were to investigate effects of β-glucan on body weight gain, food intake, food conversion ratio and serum total cholesterol, high-density lipoprotein cholesterol (HDL-cholesterol), low-density lipoprotein cholesterol (LDL- cholesterol) and triglyceride levels in female rats fed hypercholesterolemic diet. Female Sprague-Dawley rats (8-weeks-old) weighing 161.78±3.88 g were divided into three equal groups. Group 1 (control) was fed basal diet (2% liquid-vegetable oil, 0% cholesterol), group 2 was fed high-cholesterol diet (2% liquid- vegetable oil, 15% hydrogenated-oil and 1.5% cholesterol) and group 3 was fed high-cholesterol diet with 1% β-glucan. The trial period was 30 days. Blood samples were withdrawn on days 0 and 30. Also, all rats were weighed on same days. Serum total cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride levels were detected with commercial kits by auto-analyzer. Body weight gain, food intake and food conversion ratio, and serum total cholesterol and LDL-cholesterol levels were significantly lower (P<0.05) in group 3 (the group fed fatty and added β-glucan) than in the other two groups. Serum HDL-cholesterol and triglyceride levels were not significant between all groups at the end of the study. β-glucan supplementation negatively affected food intake. However, β-glucan effectively lowered serum LDL-cholesterol and total cholesterol concentrations without affecting HDL-cholesterol and triglyceride levels. Therefore, β-glucan may decrease the cholesterol synthesizing ability of liver and the risk for atherosclerotic vascular disease. ©2011 PVJ. All rights reserved To Cite This Article: Bilal T, FE Gursel, A Ates and O Keser, 2012. Effects of dietary β-glucan on serum lipids and performance indices in rats fed a diet enriched with cholesterol. Pak Vet J, 32(1): 97-100. INTRODUCTION The leading cause of morbidity and mortality in many countries in the world is still cardiovascular disease (CVD), in spite of remarkable improvements in its prevention, diagnosis and therapy (Anderson et al., 1990). Hypercholesterolemia is caused by increased concentra- tions of low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C). The increase in VLDL causes the increase in triglycerides (TGs). High TG and greater LDL-C are predictors of increased CVD risk. High-density lipoprotein cholesterol (HDL-C) concentrations provide the opposite relationship, with increased blood concentrations of HDL-C predicting reduced risk (Chen et al., 2009). To lower serum LDL-C levels by making dietary changes is the well-established way to reduce the risk of developing CVD. In addition to reducing saturated fat and cholesterol intake, and increasing cis-unsaturated fat intake, the importance of other dietary approaches, such as increasing the intake of water-soluble dietary fibers has become increasingly recognized (Theuwissen and Mensik, 2008). β-glucans are water-soluble fibers, which are found in a wide variety of product such as oats, barley, and yeast (Bell et al., 1999; Eshghi and Akhundova, 2010). One of the richest sources of β-glucan is the cell wall of baker’s yeast Saccharomyces cerevisiae. Regardless of their source, all β-glucans are polysaccha- rides composed of glucose molecules (Theuwissen and Mensik, 2008). Natural (1,3)-beta-D-glucans from yeast, grain and mushrooms are well-established biological response modifiers which represent highly conserved structural components of cell walls in yeast, fungi, seaweed or grain seeds (Borchers et al., 1999). Although the exact mechanism explaining the cholesterol-lowering effect of β-glucan is not known, the most likely explanation is that RESEARCH ARTICLE