The influence of season on oxidant–antioxidant status in trained and sedentary subjects

Effects of combined physical exercise on plasma lipid variables, paraoxonase 1 activity, and inflammation parameters in adults with obesity: a randomized clinical trial

OBJECTIVE

We aimed to investigate whether combined physical exercise may affect plasma lipid variables, paraoxonase 1 (PON1) activity, and inflammation parameters in adults with obesity.

METHODS

Thirty-six participants were recruited to complete the study protocol. The mean age was 37 ± 1 years, and the baseline body mass index was 33.0 ± 0.4 kg/m². Participants were allocated to the control group (CG) and the exercise group (EG). The EG performed three weekly sessions of combined physical exercise for 16 weeks. Plasma lipid variables, PON1 activity, and inflammatory profile were determined before and after intervention.

RESULTS

Total cholesterol levels decreased in both groups, without intergroup difference (time p = 0.001). Non-high-density lipoprotein cholesterol (HDL-C) levels decreased in both groups (time p = 0.001); however, they were lower in the EG than in the CG (p = 0.038). The EG had increased HDL-C levels, but the CG had decreased HDL-C levels (time*group p = 0.011). PON1 activity was reduced in both groups (time, p = 0.001). The Castelli risk Index I and II reduced in the EG and increased in the CG (time*group, p = 0.008 and p = 0.011, respectively). The inflammatory markers were not modified.

CONCLUSION

Adults with obesity may benefit from regular practice of combined physical exercise training in many metabolic aspects that are related to protection against the development of cardiovascular disease.

Inflammation, Peripheral Signals and Redox Homeostasis in Athletes Who Practice Different Sports

The importance of training in regulating body mass and performance is well known. Physical training induces metabolic changes in the organism, leading to the activation of adaptive mechanisms aimed at establishing a new dynamic equilibrium. However, exercise can have both positive and negative effects on inflammatory and redox statuses. In recent years, attention has focused on the regulation of energy homeostasis and most studies have reported the involvement of peripheral signals in influencing energy and even inflammatory homeostasis due to overtraining syndrome. Among these, leptin, adiponectin, ghrelin, interleukin-6 (IL6), interleukin-1β (IL1β) and tumour necrosis factor a (TNFa) were reported to influence energy and even inflammatory homeostasis. However, most studies were performed on sedentary individuals undergoing an aerobic training program. Therefore, the purpose of this review was to focus on high-performance exercise studies performed in athletes to correlate peripheral mediators and key inflammation markers with physiological and pathological conditions in different sports such as basketball, soccer, swimming and cycling.

Influence of Synbiotics on Selected Oxidative Stress Parameters

The aim of the present study was to assess synbiotic (Lactobacillus casei + inulin) influence on oxidative stress parameters such as concentrations of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), glutathione, and free sulfhydryl groups content. Experiments were carried out on healthy volunteers (n = 32). The subjects were divided into women group (n = 16) and men group (n = 16) and randomly assigned to synbiotic and control groups. Blood samples were collected before synbiotic supplementation and after 7 wks, at the end of the study. The administration of synbiotic resulted in a significant decrease in MDA (p < 0.01), H₂O₂ (p < 0.01), and GSSG concentrations (p < 0.05) as compared with the control groups and significant increase in the concentrations of GSHt (p < 0.001), GSH (p < 0.01), and -SH group content (p < 0.05) versus control. Synbiotics containing L. casei plus inulin may have positive influence on selected oxidative stress markers.

The Influence of Probiotic Lactobacillus casei in Combination with Prebiotic Inulin on the Antioxidant Capacity of Human Plasma

The aim of the present study was to assess whether probiotic bacteria Lactobacillus casei (4 × 10⁸ CFU) influences the antioxidant properties of human plasma when combined with prebiotic Inulin (400 mg). Experiments were carried out on healthy volunteers (n = 32). Volunteers were divided according to sex (16 male and 16 female) and randomly assigned to synbiotic and control groups. Blood samples were collected before synbiotic supplementation and after 7 weeks, at the end of the study. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activity, and the ferric reducing ability of plasma (FRAP) in human plasma were examined. The administration of synbiotics containing L. casei plus Inulin resulted in a significant increase in FRAP values (p = 0.00008) and CAT activity (p = 0.02) and an insignificant increase in SOD and GPx activity compared to controls. Synbiotics containing L. casei (4 × 10⁸ CFU) with prebiotic Inulin (400 mg) may have a positive influence on human plasma antioxidant capacity and the activity of selected antioxidant enzymes.

Variability of salivary markers of oxidative stress and antioxidant status in young healthy individuals

OBJECTIVES

Salivary advanced glycation end-products (AGEs), advanced oxidation protein products (AOPP), total antioxidant capacity (TAC), and ferric reducing ability of saliva (FRAS) are increased in various diseases. Little data exist for these markers in the healthy population. The aim of this study was to assess the inter-individual and intra-individual variability of AGEs, AOPP, TAC, and FRAS in the saliva of young healthy individuals.

METHODS

Unstimulated saliva samples were collected from 16 females and 18 males daily over a period of 30 days. Markers were measured using spectrophotometric and spectrofluorometric microplate-based methods.

RESULTS

All salivary markers measured were significantly higher in men than in women (P < 0.05 for AGEs; P < 0.001 for AOPP, TAC, and FRAS). The inter-individual variability was approximately 60% for AGEs and AOPP and 30-40% for TAC and FRAS in both genders. The inter-individual variability of FRAS was higher in men vs. women (P < 0.01). Intra-individual variability ranged from 20% for TAC, to 30% for AGES and FRAS and 45% for AOPP.

DISCUSSION

Intra-individual variability of salivary AGEs, AOPP, TAC, and FRAS indicates that their use is currently limited to large cohort studies. Identifying the underlying factors related to the high inter-individual and intra-individual variability is needed. Sex differences should be considered in future studies.

[Sport's related sudden death]

Non-traumatic sudden death related to sport is a rare but always dramatic event. Its causes are mainly cardiovascular. Prevention of sudden death depends on effective medical examination involving history, physical examination and resting ECG, as education of athletes who must follow the rules for safe sport practice and lastly training for emergency actions of the population.

Human catalase, its polymorphisms, regulation and changes of its activity in different diseases

Catalase (CAT) is a well-studied enzyme that plays an important role in protecting cells against the toxic effects of hydrogen peroxide. In human, it has been implicated in different physiological and pathological conditions. This review summarizes the information available on the function and role of CAT polymorphisms in pathogenesis of various pathophysiological states as well as on the regulation of CAT gene expression. Numerous studies have described the CAT polymorphisms and their link with various diseases. Changes in the CAT levels were reported in many different diseases and polymorphisms in the CAT gene were shown to be associated with different pathophysiological states, e.g. hypertension, diabetes mellitus, insulin resistance, dyslipidaemia, asthma, bone metabolism or vitiligo. Regulation of the CAT gene expression plays an important role in the levels of CAT. The catalase gene expression is regulated by various mechanisms involving e.g. peroxisome proliferator-activated receptor γ (PPARγ), tumour necrosis factor α (TNF-α), p53 protein and hypermethylation of CpG islands in the catalase promoter. Transcription of the CAT gene is mainly influenced by the -262 C/T and -844 A/G polymorphisms. A common polymorphism -262 C/T in the promoter region has been found to be associated with altered CAT activities. Apart from genetic factors, the activities of CAT may be affected by age, seasonal variations, physical activity, or a number of chemical compounds. Future investigations are necessary to elucidate the role of CAT in pathogenesis of oxidative stress-related diseases.

Prepubertal children with suitable fitness and physical activity present reduced risk of oxidative stress

To assess the impact of fitness status and physical activity on oxidative stress in prepubertal children, we measured selected biomarkers such as protein carbonyls (PC), lipid peroxidation products, and total nitrites, as well as the antioxidant system: total glutathione (TG), oxidized glutathione (GSSG), reduced glutathione (GSH), superoxide dismutase activity, and glutathione peroxidase. A total of 132 healthy children ages 7-12, at prepubertal stage, were classified into two groups according to their fitness level: low fitness (LF) and high fitness (HF). They were observed while engaged in an after-school exercise program, and a questionnaire was created to obtain information on their physical activity or sedentary habits. Plasma and red blood cells were obtained to analyze biomarkers. Regarding oxidative stress markers, the LF group and the sedentary group showed higher levels of TG and GSSG and a lower GSH/GSSG ratio than the HF group and the children engaged in physical activity. A negative association was found between PC and GSSG and TG and between TG and the GSH/GSSG ratio. Moreover, a negative correlation was found between GSSG and fitness, with a positive correlation with the GSH/GSSG ratio. TG, GSSG, and the GSH/GSSG ratio seem to be reliable markers of oxidative stress in healthy prepubertal children with low fitness or sedentary habits. This research contributes to the recognition that an adequate level of fitness and recreational physical activity in childhood leads to better health and oxidative status.

Heat stress on reproductive function and fertility in mammals

In most mammalian species including cattle, heat stress has deleterious effects on nutritional, physiological and reproductive functions. Exposure of animals to a hot environment causes an increase in body temperature in mammals, including domestic animals. High ambient temperature also causes a decrease in the length and intensity of estrus by disturbing ovarian function as well as decreasing pregnancy rate after artificial insemination. Therefore, it is important to understand the effects of heat stress on reproductive function in order to improve the production of domestic animals. Heat stress decreases appetite, weight gain, and milk yield in dairy cattle. It also adversely affects the reproductive performance of both sexes. In males, it reduces spermatogenic activity, while in females it adversely impacts oogenesis, oocyte maturation, fertilization development and implantation rate. Detection and evaluation of the deteriorating effects of heat stress on reproductive organs and cells can help to design measures to prevent them and improve reproductive functions. In this review, we discuss the impacts of heat stress on reproductive functions.

Superoxide dismutase and cytochrome P450 isoenzymes might be associated with higher risk of renal cell carcinoma in male patients

Literature data support the hypothesis that oxidative stress and the accompanying antioxidant defense might play an important role in renal cell carcinoma (RCC) growth and progression. It is also known that the incidence of renal tumors is two times higher in men than in women. Thus, the aim of this study was to determine whether the oxidant/antioxidant profile of renal cell carcinoma tissue, adjacent to tumor tissue and nontumor tissue was different in male and female patients. Significantly higher lipid peroxidation (LPO) in renal cell carcinoma tissue compared to nontumor tissue was demonstrated only in male patients. Besides, gender-related difference in copper zinc superoxide dismutase (CuZnSOD) and manganese superoxide dismutase (MnSOD) in nontumor and renal cell carcinoma tissue was obtained at the level of transcription, translation and activity of these antioxidant isoenzymes. Morever, we demonstrated that the gene expression of 3 CYPs out of 7 was altered; CYP2D6 mRNA was decreased in both sexes while gender-related suppression of mRNA for CYP2E1 (women) and CYP2C19 (men) was observed. Taken together, these parameters might be potentially responsible for higher risk of renal cell carcinoma in men than in women.

Increased oxidative stress in healthy children following an exercise program: a pilot study

Exercise can induce oxidative stress or an imbalance between reactive oxygen species and cellular antioxidant defenses.

OBJECTIVE

We investigated the effect of a real-life exercise program on systemic oxidative stress measured by urinary concentrations of 8-isoprostaglandin F2alpha (8-iso-PGF2 alpha), a noninvasive index of lipid peroxidation, in a well-characterized pediatric group.

METHODS

Healthy but primarily sedentary, 8- to 10-year-old children (n = 6, mean age 8.8 +/- 0.9 years) of equally distributed healthy weight, overweight, and obese categories, participated in a 5-week exercise program (track and field summer camp, 2 hours/day, 1-2 days/week).

RESULTS

By using high-performance liquid chromatography with online electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS), we found a significant (p = .028) increase in group mean urinary 8-iso-PGF2 alpha concentration from 8.163 +/- 6.919 ng/mg creatinine pre-exercise program to 32.320 +/- 16.970 ng/mg creatinine post-exercise program. The increase was also measured at each individual level. We found preliminary evidence that pre- and post-exercise program urinary 8-iso-PGF2 alpha concentrations selectively correlated with children's cardiometabolic characteristics and mood.

CONCLUSION

Our results warrant further exploration of the relationships between pre/post-exercise oxidative stress marker 8-iso-PGF2 alpha and cardiometabolic characteristics, exercise habits, eating habits, and mood to determine whether increased post-exercise oxidative stress in healthy children is part of their normal adaptation to exercise or mediator of oxidative injury.

Oxidative stress and DNA damage in older adults that do exercises regularly

OBJECTIVES

Free radicals may damage lipids, proteins and DNA, which may lead to critical diseases in the aging. This work evaluated levels of malondialdehyde (MDA), glutathione peroxidase (GPx) and DNA damage by comet assay (SCGE) in older adults that do exercises regularly.

DESIGN AND METHODS

110 females, aged 66.3+/-8 years were divided into sedentary (n=54), walking (n=36) and muscle building (n=20) groups. Levels of MDA, GPx and SCGE were measured in venous blood before and after exercise.

RESULTS

MDA levels were higher (P<0.005) and GPx levels were lower (P<0.005) in active groups than in sedentary group. SCGE index after physical activity was greater than at baseline (muscle building: P=0.004; walking: P=0.002).

CONCLUSIONS

Exercise reduces the diseases risk, but may promote the production of free radicals. It remains unclear whether cell adaptations responsible for health benefits are associated with such events. However we may suggest the existence of a different biochemical pattern for older adults that do exercise regularly.

Effects of strength and endurance training on antioxidant enzyme gene expression and activity in middle-aged men

This study was aimed at investigating the effects of a 21-week period of progressive strength or endurance training on peripheral blood mononuclear cells (PBMC) antioxidant enzyme gene expression and activity in healthy middle-aged untrained men. Strength (n=11) and endurance (n=12) training were performed twice a week, including resistance exercises to activate all the main muscle groups or cycle-ergometer pedaling, respectively. mRNA levels of catalase, glutathione peroxidase (GPx), mitochondrial superoxide dismutase (MnSOD) and cytosolic superoxide dismutase (CuZnSOD) were increased after 21 weeks of strength training, while endurance training induced significant changes only in MnSOD and GPx mRNA levels. CuZnSOD protein content was significantly increased only in strength-trained subjects. The program of strength or endurance exercise training had no significant effects on the activity of any of the antioxidant enzymes. In conclusion, in a middle-aged population, 21 weeks of strength or endurance training was a sufficient stimulus to up-regulate mRNA levels of PBMC antioxidant enzymes, the strength training being a more optimal stimulus. However, the discrepancies between enzyme protein and mRNA levels suggest that the present systematic strength or endurance training period had no beneficial effects on enzymatic antioxidant defense mechanisms in previously untrained middle-aged men.

Acute exercise markedly increases blood oxidative stress in boys and girls

This study investigated the effect of an acute swimming protocol on selected blood redox status indices in trained children. Eleven boys and 11 girls (aged 9–11 y) swam 12 bouts of 50 m at a pace corresponding to 70%–75% of the participant’s 50 m maximum velocity, with each bout separated by 1 min rest periods. At rest, no differences in any redox status marker between boys and girls were observed. As compared with the pre-exercise values, significant increases in thiobarbituric acid-reactive substances (TBARS), protein carbonyls, catalase activity, total antioxidant capacity (TAC), and oxidized glutathione (GSSG) concentration, as well as significant decreases in reduced glutathione (GSH) concentration and GSH:GSSG, were found post-exercise in both boys and girls. The magnitude of the exercise-induced alterations in the blood redox status based on the calculated effect sizes could be considered large for all parameters in both sexes (median effect size in absolute values was equal to 1.38). The main finding of the present study is that an acute swimming bout at 70%–75% maximum velocity resulted in blood oxidative stress in a similar manner in both trained young boys and girls.

Effects of adaptive exercise on apoptosis in cells of rat renal tubuli

Regular exercise is known to improve physiological and functional capacity of many organs due to adaptive processes. We have previously shown that acute exercise in untrained rats results in apoptosis of renal tubular cells and that the apoptotic process seems to be associated with stimulation of angiotensin II, AT1 and AT2 receptors. In this study, we examined the influence of regular training on apoptosis and the role of angiotensin II receptors and antioxidant enzymes in mediating the adaptive response in renal tubular cells. We measured apoptosis, expression of AT1 and AT2 receptors, level of lipid peroxidation (TBARS) and activities of antioxidant enzymes, SOD, GPx and CAT in kidneys of sedentary rats that were exposed to acute exercise and rats that were trained for 8 weeks. In untrained animals, the acute exercise resulted in increased apoptosis and increased expression of AT1 and AT2 receptors in renal tubular cells, while in the rats exposed to the 8-week regular training, there were no changes in apoptosis nor AT1 and AT2 receptor expression as compared to the sedentary animals. The TBARS levels were significantly increased in acutely exercised rats, while in rats pre-exposed to the training they remained unchanged. The acute exercise, as well as regular training, did not change SOD, CAT or GPx activities. These findings suggested that the acute exercise-induced apoptosis in renal tubules could involve action of AT1 and AT2 receptors as well as oxidative stress, while the regular training was shown to prevent apoptosis in renal tubular cells via modulated expression of AT1 and AT2 receptors.