Biochemical assessments of oxidative stress, erythrocyte membrane fluidity and antioxidant status in professional soccer players and sedentary controls.

BACKGROUND: Physical exercise is characterized by an increase in oxygen consumption by the whole body. This leads to a decrease in antioxidant levels that could promote both an increase in the markers of lipoprotein peroxidation and damage to the erythrocyte membrane with consequent modification of membrane fluidity. MATERIALS AND METHODS: Different markers of oxidative stress, erythrocyte membrane fluidity and antioxidant status were determined in 20 professional soccer players and 20 sedentary controls. Plasma lipoperoxides and kinetics of Cu-stimulated plasma peroxidation were measured together with hydrosoluble (albumin, uric acid and vitamin C), liposoluble (vitamin E and bilirubin) and enzymatic (superoxide dismutase and glutathione peroxidase) serum antioxidants. Erythrocyte membrane rigidity was determined by measuring fluorescence anisotropy (rs) of the fluorescent probe 1, 3, 5 diphenylexatriene. RESULTS: The sportsmen showed higher levels of the following plasmatic antioxidants: ascorbic acid (P<0.0001), uric acid (P<0.0001), alpha-tocopherol (P=0.03) and superoxide dismutase activity (P=0.0001). According to this evidence, the lipoperoxide levels (P=0.0158), the duration of the latency phase of plasma peroxidation (P=0.0123) and erythrocytes membrane fluidity (P=0.0152) were found to be significantly higher in the soccer players. DISCUSSION: Athletes undergoing regular and adequate training show improved antioxidant status together with a more fluid membrane status, which could contribute to improving both peripheral resistance to insulin and all the functional metabolic interchanges in the cellular membrane.

[The hypocaloric balanced diet therapy and the supplementation with antioxidant and omega-3: what are the effects on the oxidative balance and erythrocytes membrane fluidity status?]. / La dietoterapia ipocalorica bilanciata personalizzata ed il trattamento con integratori a base di antiossidanti e omega-3: quali gli effetti sullo stato della bilancia ossidativa e della fluidità delle membrane eritrocitarie in un gruppo di donne in sovrappeso?

BACKGROUND: To investigate the effects of a hypocaloric balanced diet therapy and a supplementation with antioxidant and omega-3 polyunsaturated fatty acids on the oxidative balance and erythrocytes membrane fluidity status. METHODS: A randomised, double-blind, placebo-controlled study of the association between a hypocaloric balanced diet therapy and a supplementation with antioxidant and omega-3 was done on 40 women with 25 < BMI < 33. The inclusion criteria were the following: absence of dismetabolic pathologies, of previous hypocaloric diet therapy and/or supplementation and of hormonal treatments. Each subjects consumed a balanced diet with a daily caloric intake equal to: Kcal of basal metabolism (determined by indirect calorimetry) x LAF (1.64) 800 Kcal. At the start and after two months of treatment, the blood chemistry and anthropometrics parameters, the plasmatic reactive oxygen species (ROS) and antioxidant defence levels and erythrocyte membrane fluidity status were measured. RESULTS: The preliminary results of this study show that the weight loss, found in both groups investigated, determines a significant decrease of ROS. Furthermore, the association of the hypocaloric diet with antioxidant and omega-3 polyunsaturated fatty acids caused a significant increase of both plasmatic antioxidant defences and erythrocytes membrane fluidity status. CONCLUSIONS: The correlations found between the above parameters and the blood chemistry and anthropometrics variables suggest that the supplementation with antioxidant and omega-3 polyunsaturated fatty acids could ameliorate the effects of hypocaloric diet on the obesity treatment and may give some clinical benefit through the decrease of the values of atherosclerosis risk factors.