• Antioxidant responses following active and passive smoking of tobacco and electronic cigarettes

      Poulianiti, Konstantina; Karatzaferi, Christina; Flouris, Andreas D; Fatouros, Ioannis G; Koutedakis, Yiannis; Jamurtas, Athanasios Z (Taylor & Francis, 2016-07-27)
      It has been indicated that acute active and passive tobacco cigarette smoking may cause changes on redox status balance that may result in significant pathologies. However, no study has evaluated the effects of active and passive e-cigarette smoking on redox status of consumers.
    • Comparison between G6PD-Deficient and Normal Individuals after Eccentric Exercise

      Theodorou, Anastasios A.; Nikolaidis, Michalis G.; Paschalis, Vassilis; Sakellariou, Georgios K.; Fatouros, Ioannis G.; Koutedakis, Yiannis; Jamurtas, Athanasios Z. (American College of Sports Medicine, 2010)
      Purpose: Theoretically, glucose-6-phosphate dehydrogenase (G6PD)-deficient compared with nondeficient individuals may be less capable of performing physical activities and/or may be more vulnerable to muscle damage and oxidative stress. Therefore, the purpose of the present study was to examine the effects of a resistance muscle-damaging exercise bout on muscle function and damage, redox status in plasma, and erythrocytes and hemolysis. Methods: Nine males with established G6PD deficiency and nine males with normal G6PD activity performed an eccentric muscledamaging exercise protocol. Isometric torque, range of motion, delayed onset muscle soreness, and creatine kinase were measured as indices of muscle function and damage. Reduced glutathione, oxidized glutathione, thiobarbituric acid–reactive substances, protein carbonyls, catalase, uric acid, and total antioxidant capacity were measured as indices of blood redox status. Plasma hemoglobin and bilirubin were measured as indices of hemolysis. All measurements conducted before, immediately after, and 1, 2, 3, 4, and 5 d after exercise. Results: All indices measured confirmed that eccentric exercise induced severe muscle damage, oxidative stress, and hemolysis, peaking at 2 and 3 d postexercise. Lower resting levels of reduced glutathione were detected in the G6PD-deficient group compared with the control group. Nevertheless, both the time course and the magnitude of the changes of the selected muscle performance, redox status (both in plasma and in erythrocytes), and hemolysis indices measured were similar between the two groups. Conclusions: The present study indicates that G6PD-deficient individuals may participate in high-intensity muscle-damaging activities, without a negative impact on muscle function, blood redox status, and hemolysis
    • Enhanced erythrocyte antioxidant status following an 8-week aerobic exercise training program in heavy drinkers

      Georgakouli, K; Manthou, E; Fatouros, IG; Georgoulias, P; Deli, CK; Koutedakis, Y; Theodorakis, Y; Jamurtas, AZ; Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala 42100, Greece; Institute of Human Performance and Rehabilitation, Centre for Research and Technology - Thessaly (CERETETH), Karies, Trikala 42100, Greece. Electronic address: kgeorgakouli@gmail.com. (Elsevier BV, 2017-12-02)
      © 2017 Elsevier Inc. Alcohol-induced oxidative stress is involved in the development and progression of various pathological conditions and diseases. On the other hand, exercise training has been shown to improve redox status, thus attenuating oxidative stress-associated disease processes. The purpose of the present study was to evaluate the effect of an exercise training program that has been previously reported to decrease alcohol consumption on blood redox status in heavy drinkers. In a non-randomized within-subject design, 11 sedentary, heavily drinking men (age: 30.3 ± 3.5 years; BMI: 28.4 ± 0.86 kg/m2) participated first in a control condition for 4 weeks, and then in an intervention where they completed an 8-week supervised aerobic training program of moderate intensity (50–60% of the heart rate reserve). Blood samples were collected in the control condition (pre-, post-control) as well as before, during (week 4 of the training program), and after intervention (week 8 of the training program). Samples were analyzed for total antioxidant capacity (TAC), thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), uric acid (UA), bilirubin, reduced glutathione (GSH), and catalase activity. No significant change in indices of redox status in the pre- and post-control was observed. Catalase activity increased (p < 0.05) after 8 weeks of intervention compared to week 4. GSH increased (p < 0.05) after 8 weeks of intervention compared to the control condition and to week 4 of intervention. TAC, UA, bilirubin, TBARS, and PC did not significantly change at any time point. Moreover, concentrations of GSH, TBARS, and catalase activity negatively correlated with alcohol consumption. In conclusion, an 8-week aerobic training program enhanced erythrocyte antioxidant status in heavy drinkers, indicating that aerobic training may attenuate pathological processes caused by alcohol-induced oxidative stress.
    • Ergogenic and Antioxidant Effects of Spirulina Supplementation in Humans

      Kalafati, Maria; Jamurtas, Athanasios Z.; Nikolaidis, Michalis G.; Paschalis, Vassilis; Theodorou, Anastasios A.; Sakellariou, G. K.; Koutedakis, Yiannis; Kouretas, Dimitris (American College of Sports Medicine, 2010)
      Purpose: Spirulina is a popular nutritional supplement that is accompanied by claiMSS for antioxidant and performance-enhancing effects. Therefore, the aim of the present study was to examine the effect of spirulina supplementation on (i) exercise performance, (ii) substrate metabolism, and (iii) blood redox status both at rest and after exercise. Methods: Nine moderately trained males took part in a double-blind, placebo-controlled, counterbalanced crossover study. Each subject received either spirulina (6 gd-1) or placebo for 4 wk. Each subject ran on a treadmill at an intensity corresponding to 70%–75% of their VO2max for 2 h and then at 95% VO2max to exhaustion. Exercise performance and respiratory quotient during exercise were measured after both placebo and spirulina supplementation. Blood samples were drawn before, immediately after, and at 1, 24, and 48 h after exercise. Reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG, thiobarbituric acid-reactive substances (TBARS), protein carbonyls, catalase activity, and total antioxidant capacity (TAC) were determined. Results: Time to fatigue after the 2-h run was significantly longer after spirulina supplementation (2.05 ± 0.68 vs 2.70 ± 0.79 min). Ingestion of spirulina significantly decreased carbohydrate oxidation rate by 10.3% and increased fat oxidation rate by 10.9% during the 2-h run compared with the placebo trial. GSH levels were higher after the spirulina supplementation compared with placebo at rest and 24 h after exercise. TBARS levels increased after exercise after placebo but not after spirulina supplementation. Protein carbonyls, catalase, and TAC levels increased similarly immediately after and 1 h after exercise in both groups. Conclusions: Spirulina supplementation induced a significant increase in exercise performance, fat oxidation, and GSH concentration and attenuated the exercise-induced increase in lipid peroxidation.
    • Uniform and prolonged changes in blood oxidative stress after muscle-damaging exercise

      Paschalis, Vassilis; Nikolaidis, Michalis G.; Fatouros, Ioannis; Giakas, Giannis; Koutedakis, Yiannis; Karatzaferi, Christina; Kouretas, Dimitris; Jamurtas, Athanasios Z. (International Institute of Anticancer Research, 2007)
      Background: The effect of eccentic exercise on the time-course changes in several indices of muscle damage and blood oxidative stress as examined. Materials and methods: Isometric rorque, delayed-onset muscle soreness, creatine kinase, reduced glutathione (GSH), oxidized glutathione (GSSG), thiobarbituric-acid reactive substances (TBARS), protein carbonyls, catalase, uric acid, bilirubin and total antioxidant capacity (TAC) in blood were measured pre-, 24 h, 48 h and 72 h post-exercise of knee extensors in ten females. Results: The concentration of all oxidative stress indices changed significantly in a way indicating increased oxidative stress in the blood (GSH and GSH/GSSG, decreased, whereas GSSG, TBARS, protein carbonyls, catalase, uric acid, bilirubin and TAC increased) peaking, in all but TBARS, at 48 h and returning towards baseline afterwards. Conclusion: We believe that muscle-damaging exercise should be viewedd as a different challenge compared to non-muscle-damaging exercise with regard to its effects on blood oxidative stress.