Citrulline: Modulation on Protein Synthesis, Intestinal Homeostasis and Antioxidant Status

Special Article - Nutrition Diet

Int J Nutr Sci. 2019; 4(2): 1033.

Citrulline: Modulation on Protein Synthesis, Intestinal Homeostasis and Antioxidant Status

Xu XM1,2, Wu CM1,2, Jia G1,2, Zhao H1,2, Chen XL1,2, Wang J3 and Liu GM1,2*

1Institute of Animal Nutrition, Sichuan Agricultural University, China

2Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, China

3Maize Research Institute, Sichuan Agricultural University, China

*Corresponding author: Liu GM, Institute of Animal Nutrition, Sichuan Agricultural University, 211 Huimin St, Wenjiang District, Chengdu, Sichuan, China, Email: liugm@sicau.edu.cn

Received: June 17, 2019;Accepted: July 09, 2019; Published: July 16, 2019

Abstract

Citrulline, a nonessential amino acid, is an important precursor substance of arginine. It has been implicated in diverse biological and physiological events, such as nitrogen balance, growth and development, muscle performance, and intestinal homeostasis, but its underlying mechanism in intestinal function is unclear. This review discusses the modulation effects of citrulline on protein synthesis and intestinal homeostasis, as well as its potential mechanisms to broaden its application.

Keywords: Citrulline; Protein synthesis; Intestinal homeostasis; Antioxidant; Nitrogen balance; Gut barrier

Introduction

Citrulline (C6H13N3O3), a key intermediate of urea cycle, mainly exist in the watermelon in nature [1]. In mammals, enterocytes have a significant effect on the circulating citrulline levels [2]. Citrulline is essential for various regulation processes, especially during sepsis and endotoxemia [3], and plays an important role in protein synthesis and intestinal homeostasis. Studies have found that citrulline regulates nitrogen balance [4], growth and development [5,6], muscle performance [7], gut barrier function [8-11] intestinal digestion and absorption [12], intestinal cell apoptosis [13] and antioxidant function [4,14,15]. The present review briefly highlights the significant role of citrulline in animals in the modulation of protein synthesis and intestinal homeostasis and points out its potential mechanisms.

Physicochemical property

The term citrulline (Figure 1) was derived from watermelon (Citrullus vulgaris) in the 1930s [16]. Citrulline has a molecular weight of 175.19 g/mol and presents two enantiomers, namely, the L and D forms. In nature, citrulline exists in the L form. Under normal temperature and pressure, citrulline is a white crystal or crystalline powder. Citrulline has a melting point of 222 °C and density of 1.289 g/cm [17]. It is well soluble in water but not in ethanol, ether, and methanol [17].