382 THE JOURNAL OF SPORTS MEDICINE AND PHYSICAL FITNESS August 2012 cer training and soccer exercise are associated with excessive production of free radicals and oxidative stress, which might diminish antioxidant system eficiency. Supplementation with Asx could prevent exercise induced free radical produc- tion and depletion of non-enzymatic antioxidant defense in young soccer players Key words: Astaxanthine - Soccer - Oxidative stress. A erobic exercise of suficient intensity and dura- tion can result in increased production of reac- tive oxygen species (ROS) in various tissues. 1 Pro- longed exercise leads to the increased production of ROS by the mitochondrial electron transport chain through an increase in oxygen consumption. 2 Also, xanthine oxidase is activated via the ischemia–reper- fusion process during exercise, resulting in the pro- duction of ROS. 3 The imbalance between enhanced ROS production and the ability of antioxidant sys- tems to render them inactive, lead to cellular loss of redox homeostasis and to prone conditions of oxida- tive damage to cellular lipids, proteins and DNA. 4 Additionally, the emerging role of ROS in the de- layed-onset muscle soreness and muscle injury has been recently reported. 5 ROS mediated sarcolemmal 1 Institute for Bromatology, Faculty of Pharmacy University of Belgrade, Belgrade, Serbia 2 Institute for Medical Biochemistry Faculty of Pharmacy University of Belgrade, Belgrade, Serbia 3 Sports Medicine Association of Serbia Outpatient Clinic Vita Maximam, Belgrade, Serbia B. DJORDJEVIC 1 , I. BARALIC 1 , J. KOTUR-STEVULJEVIC 2 , A. STEFANOVIC 2 J. IVANISEVIC 2 , N. RADIVOJEVIC 3 , M. ANDJELKOVIC 3 , N. DIKIC 3 Effect of astaxanthin supplementation on muscle damage and oxidative stress markers in elite young soccer players Aim. The purpose of the current study was to examine the effect of Astaxanthin (Asx) supplementation on muscle en- zymes as indirect markers of muscle damage, oxidative stress markers and antioxidant response in elite young soccer play- ers. Methods. Thirty-two male elite soccer players were randomly assigned in a double-blind fashion to Asx and placebo (P) group. After the 90 days of supplementation, the athletes per- formed a 2 hour acute exercise bout. Blood samples were ob- tained before and after 90 days of supplementation and after the exercise at the end of observational period for analysis of thiobarbituric acid-reacting substances (TBARS), advanced oxidation protein products (AOPP), superoxide anion (O 2 • ¯), total antioxidative status (TAS), sulphydril groups (SH), su- peroxide-dismutase (SOD), serum creatine kinase (CK) and aspartate aminotransferase (AST). Results. TBARS and AOPP levels did not change throughout the study. Regular training signiicantly increased O 2 • ¯ levels (main training effect, P<0.01). O 2 • ¯ concentrations increased after the soccer exercise (main exercise effect, P<0.01), but these changes reached statistical signiicance only in the P group (exercise x supplementation effect, P<0.05). TAS lev- els decreased signiicantly post- exercise only in P group (P<0.01). Both Asx and P groups experienced increase in total SH groups content (by 21% and 9%, respectively) and sup- plementation effect was marginally signiicant (P=0.08). Ba- sal SOD activity signiicantly decreased both in P and in Asx group by the end of the study (main training effect, P<0.01). All participants showed a signiicant decrease in basal CK and AST activities after 90 days (main training effect, P<0.01 and P<0.001, respectively). CK and AST activities in serum signiicantly increased as result of soccer exercise (main ex- ercise effect, P<0.001 and P<0.01, respectively). Postexercise CK and AST levels were signiicantly lower in Asx group compared to P group (P<0.05) Conclusion. The results of the present study suggest that soc- Corresponding author: I. Baralic, Vatroslava Lisinskog 19/17, 11000 Belgrade, Serbia. E-mail: ivanabaralic111@gmail.com BODY COMPOSITION, NUTRITION, SUPPLEMENTATION ORIGINAL ARTICLES J SPORTS MED PHYS FITNESS 2012;52:382-92 MINERVA MEDICA COPYRIGHT® This document is protected by international copyright laws. No additional reproduction is authorized. It is permitted for personal use to download and save only one file and print only one copy of this Article. It is not permitted to make additional copies (either sporadically or systematically, either printed or electronic) of the Article for any purpose. It is not permitted to distribute the electronic copy of the article through online internet and/or intranet file sharing systems, electronic mailing or any other means which may allow access to the Article. The use of all or any part of the Article for any Commercial Use is not permitted. The creation of derivative works from the Article is not permitted. The production of reprints for personal or commercial use is not permitted. It is not permitted to remove, cover, overlay, obscure, block, or change any copyright notices or terms of use which the Publisher may post on the Article. It is not permitted to frame or use framing techniques to enclose any trademark, logo, or other proprietary information of the Publisher.