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Regular physical activity induces oxidative stress but also causes adaptations in antioxidant defences including the nuclear factor κB (NF-κB) pathway, which activates target genes related to antioxidant defences such as uncoupling proteins (UCPs), and mitochondrial biogenesis mediated by peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). The aim of the study was to determine the effect of long-term training and acute exercise on oxidant/antioxidant status and the expression of mitochondrial biogenesis genes in peripheral blood mononuclear cells (PBMCs). Twelve professional football players performed an 8-week exercise programme comprising a daily 2-h football training session. Blood samples were taken before and after the training season. The results reported a significant increase in antioxidant protein levels and in mitochondrial proteins in resting conditions after the 8-week training period. PGC1α, UCP-2 and mitofusin 2 protein levels also increased after acute exercise compared to pre-exercise levels. After the training, the expression of PGC1α, cytochrome c oxidase subunit IV and mitochondrial NADH dehydrogenase subunit 5 messenger RNA (mRNA) significantly augmented after the acute physical activity compared to pre-exercise levels; while no changes occurred in these mRNA in basal conditions. NF-κB activation and ROS production reported a significant increase after acute exercise. Training increases the levels of proteins related to mitochondrial biogenesis and improves the antioxidant capabilities of mitochondria in PBMCs among well-trained football players. Acute exercise may act as an inducer of mitochondrial biogenesis through NF-κB activation and PGC1α gene expression.

Our aim was to investigate the effects of diet supplementation with phytoestrogens on sex hormone levels, antioxidant adaptive responses and oxidative damage induced by exercise. Ten female swimmers participated for 26 days in a diet intervention with either a functional beverage rich in vitamins C and E or the same beverage but also supplemented with Lippia citriodora extract (PLX) containing 20 mg/100 ml verbascoside. After the intervention all subjects participated in a swimming session for 30 min maintaining the intensity at about 75-80% of their individual best performance time for a 50-m swim. In lymphocytes, the superoxide dismutase activity increased after exercise, with a higher increase in the PLX group. Swimming increased the erythrocyte activity of glutathione peroxidase and glutathione reductase in the PLX group. Purified glutathione reductase activity increased after an in vitro incubation with PLX. No effects were observed on the lymphocyte levels of malondialdehyde and carbonyls, but exercise increased the percentage of high-damaged lymphocytes 2.8 times in the placebo group and 1.5 times in the PLX group. PLX decreased the levels of 17-β-estradiol and testosterone and increased the levels of the sex hormone binding globulin. In conclusion, supplementation with phytoestrogens enhances the glutathione-dependent enzyme activities in erythrocytes and the superoxide dismutase activity in lymphocytes in response to exercise. PLX also shows direct antioxidant properties, by increasing glutathione reductase enzyme activity in vitro. Supplementation with phytoestrogens also decreases the plasma steroid hormone levels, pointing towards a possible agonistic effect of verbascoside in the hypothalamic regulation of estradiol synthesis.

The response of lymphocyte and plasma antioxidant defences to a prolonged exercise as a cycling stage in a professional race was analysed. Antioxidant enzyme activities and gene expression, carbonyl derivative and MDA levels were determined in lymphocytes. Plasma levels of vitamin E, carotenes, protein carbonyl derivatives and the test d-Roms were measured. Significant increases in plasmatic carbonyls and in the test d-Roms were observed after the cycling stage. No significant differences were found in the lymphocyte MDA and carbonyl derivative levels. A significant increase was found in plasma vitamin E concentration after the cycling stage; however, the lymphocyte vitamin E concentration did not change. Significant increases were observed in lymphocyte total superoxide dismutase (SOD) activity and in the levels of CuZn-SOD and Mn-SOD isoenzymes. The moderate levels of oxidative stress in the lymphocyte induced a cellular adaptation to exercise enough to counteract the negative effects of oxidative stress.

Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid catabolism and limited l-arginine availability. Oral l-citrulline supplementation raises plasma l-arginine concentration and augments NO-dependent signalling. Our aim was to evaluate the effects of diet supplementation with l-citrulline-malate prior to intense exercise on the metabolic handle of plasma amino acids and on the products of metabolism of arginine as creatinine, urea and nitrite and the possible effects on the hormonal levels. Seventeen voluntary male pre-professional cyclists were randomly assigned to one of two groups: control or supplemented (6 g l-citrulline-malate 2 h prior exercise) and participated in a 137-km cycling stage. Blood samples were taken in basal conditions, 15 min after the race and 3 h post race (recovery). Most essential amino acids significantly decreased their plasma concentration as a result of exercise; however, most non-essential amino acids tended to significantly increase their concentration. Citrulline-malate ingestion significantly increased the plasma concentration of citrulline, arginine, ornithine, urea, creatinine and nitrite (p < 0.05) and significantly decreased the isoleucine concentration from basal measures to after exercise (p < 0.05). Insulin levels significantly increased after exercise in both groups (p < 0.05) returning to basal values at recovery. Growth hormone increased after exercise in both groups, although the increase was higher in the citrulline-malate supplemented group (p < 0.05). l-citrulline-malate supplementation can enhance the use of amino acids, especially the branched chain amino acids during exercise and also enhance the production of arginine-derived metabolites such as nitrite, creatinine, ornithine and urea.

The aim of the study was to determine the effects of an antioxidant supplementation, which includes coenzyme Q(10), on plasma and neutrophil oxidative stress and the antioxidant response after a soccer match. Nineteen voluntary male pre-professional footballers were randomly and double-blinded treated with either a multivitamin and mineral supplement (n = 8) or a placebo (n = 11). After the 3 months of supplementation, the sportsmen played a friendly soccer match of 60 min. The 3-month supplementation induced higher plasma ascorbate and coenzyme Q levels when compared to the placebo group. Antioxidant supplementation influenced plasma oxidative stress markers because they were lower in the supplemented group than in the placebo one after the match. The football match induced decreased neutrophil vitamin E levels and catalase and glutathione peroxidase activities but increased glutathione reductase activity. Antioxidant diet supplementation prevented plasma oxidative damage but did not influence the neutrophil response to a football match.