The Effect of Glutamine Supplementation on Exercise-Induced Oxidative Stress B. Nakhostin-Roohi Department of Exercise Physiology, Ardabil Branch, Islamic Azad University, Ardabil, Iran Email: b.nakhostinroohi@iauardabil.ac.ir R. Javanamani Science and Research Branch, Islamic Azad University, Guilan, Iran Email: r.jamani@yahoo.com Abstract—The shift in balance between oxidant/antioxidant in favor of oxidants is termed oxidative stress. Physical exercise may increase accumulation of free radicals and induce oxidative stress. The aim of this study was to evaluate effect of 7 day glutamine supplementation on exercise-induced oxidative stress. Nineteen healthy, nonsmoking, young men were recruited to participate in this study. Participants were randomized in a double-blind placebo-controlled fashion into 2 groups: Glutamine (G group) (n = 9) and placebo (P group) (n = 10). Subjects consumed daily either placebo (1.5 g/kg glutamine + 250ml water + 15g sweetener) or glutamine (250ml water + 15g sweetener) for 7 days. Then, Participants ran 14 km. Blood samples were taken before supplementation, before exercise, immediately, and 1h after exercise. TAC significantly increased immediately after exercise compared with pre- exercise just in G group (P<0.05). There was significant GHS increasein G group after supplementation, immediately, and 1h after exercise, but just 1h after exercise in P group compared with baseline(P<0.05). MDA-TBARS significantly increased 1h after exercise compared with pre- exercise just in P group (P<0.05). It seems 7day glutamine supplementation has been able to affectoxidative stress markers via possibly effect on antioxidant agents. Index Terms—glutamine, supplementation, oxidative stress, reduced glutathione. I. INTRODUCTION Regular physical activity and exercise are recommended for the maintenance of an optimal health status and the prevention or management of chronic diseases. However, physical exercise may increase accumulation of free radicals and induce oxidative stress as a response to the increased oxygen consumption. Under normal physiological conditions, the cellular antioxidant system removes reactive oxygen species (ROS) and other inflammatory molecules [1]. However, oxidative stress occurs when there is an imbalance between the production of free radicals and antioxidant defense [2]. The cells in our body continuously produce free radicals and reactive oxygen species (ROS) as part of metabolic processes [3].Oxidative stress can occur as a Manscript received August 29, 2014; revised December 23, 2014. consequence of a general increase in ROS generation, a depression of the antioxidant defense system (enzymatic and non-enzymatic), or both [4].Oxidative stress causes damage to biologic macromolecules such as nucleic acids, membrane lipids, and proteins, and hence disrupts normal physiological function [5]. Evidence for increased ROS production during and following exercise is provided by numerous investigations that have noted an increase in various oxidative stress biomarkers following both acute aerobic and anaerobic exercise [6], [7]. During strenuous exercises, an insufficiency of endogenous antioxidants may cause antioxidant defense systems to be temporarily overwhelmed. Supplementation of these systems with antioxidants may therefore reduce oxidative stress [8]. Measurement of various antioxidant or oxidant parameters can be used to determine the risk of oxidative stress or the effectiveness of antioxidant supplementation [9]-[12]. Glutamine is an important constituent of proteins and is a precursor for the synthesis of amino acids, nucleotides, nucleic acids, amino sugars, and several other biologically important molecules [13], [14]. It is the most abundant amino acid in plasma as well as skeletal muscle and accounts for more than 60% of the total intramuscular free amino acid pool [15], [16]. Glutamine is largely synthesized in skeletal muscles and precursors to gluconeogenesis in the liver. Physical exercise is known to affect glutamine synthesis and to modulate glutamine uptake [17]. Glutamine, a nonessential amino acid, has received increasing attention because it becomes essential during stress and catabolic conditions [18]. Moreover, According to some researches, glutamine has antioxidant capacity. Its administration can result in an enhanced antioxidant capacity in various situations, such as critical illness or sepsis [19]. It seems glutamine exerts its antioxidant property through promotion of reduced glutathione synthesis [19]. Strenuous physical exercise as well as prolonged endurance-like programs leads to glutamine depletion due to lowered synthesis and enhanced uptake by liver and immune cells [20]. Nevertheless, based on a literature survey, the alleviating or augmenting action of glutamine on oxidative stress following acute strenuous exercise in humans has not been reported. Journal of Advanced Agricultural Technologies Vol. 2, No. 1, June 2015 8 doi: 10.12720/joaat.2.1.8-12 © 2015 Journal of Advanced Agricultural Technologies