Leucine improves protein nutritional status and regulates hepatic lipid metabolism in calorie-restricted rats

Author(s)

Pedroso, Joao Alfredo B. ^{[1, 2]} ; Nishimura, Luciana Sigueta ^[2] ; de Matos-Neto, Emidio Marques ^[3] ; Donato, Jr., Jose ^[1] ; Tirapegui, Julio ^[2]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Pharmaceut Sci, Dept Food Sci & Expt Nutr, BR-05508900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Inst Biomed Sci, Dept Cell & Dev Biol, BR-05508900 Sao Paulo - Brazil

• Document type: Journal article
• Source: Cell Biochemistry and Function; v. 32, n. 4, p. 326-332, JUN 2014.
• Web of Science Citations: 7

Abstract

Several studies have highlighted the potential of leucine supplementation for the treatment of metabolic diseases including type 2 diabetes and obesity. Caloric restriction is a common approach to improve the health in diabetic and obese subjects. However, very few studies assessed the effects of leucine supplementation in calorie-restricted animals. Rats were subjected to a 30% calorie-restricted diet for 6weeks to study the effects of leucine supplementation on protein status markers and lipid metabolism. Caloric restriction reduced the body weight. However, increased leucine intake preserved body lean mass and protein mass and improved protein anabolism as indicated by the increased circulating levels of albumin and insulin-like growth factor-1 (IGF-1), and the liver expression of albumin and IGF-1 messenger RNA. Leucine supplementation also increased the circulating levels of interleukin-6 and leptin but did not affect the tumour necrosis factor-alpha and monocyte chemotactic protein-1 concentrations. Ketone bodies were increased in rats consuming a leucine-rich diet, but we observed no changes in cholesterol or triglycerides concentrations. Caloric restriction reduced the liver expression of peroxisome proliferator activated receptor-alpha and glucose-6-phosphatase, whereas leucine supplementation increased the liver expression of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA) reductase and sterol regulatory element-binding transcription factor 1. A leucine-rich diet during caloric restriction preserved whole body protein mass and improved markers of protein anabolism. In addition, leucine modulated the hepatic lipid metabolism. These results indicate that increased leucine intake may be useful in preventing excessive protein waste in conditions of large weight loss. Copyright (C) 2013 John Wiley \& Sons, Ltd. (AU)

• FAPESP's process: 11/11792-0 - Effect of caloric restriction and leucine supplementation on markers of inflammation and expression of proteins involved in insulin signaling pathway and protein synthesis in untrained rats
• Grantee: Julio Orlando Tirapegui Toledo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 10/18086-0 - Molecular basis of leptin resistance
• Grantee: Jose Donato Junior
• Support Opportunities: Research Grants - Young Investigators Grants