Influence of exercise on oxidant stress products in elite Indian cyclists

Endurance training and MitoQ supplementation improve spatial memory, VEGF expression, and neurogenic factors in hippocampal tissue of rats

Background and Aim

The hippocampus has a key role in memory and learning, which means that this brain structure has high-energy demand. Accordingly, mitochondrial dysfunction in the hippocampus has deleterious effects on brain function. MitoQ is an antioxidant that accumulates selectively in mitochondria at high concentration. In this study, the effect of MitoQ alone and in combination with endurance training (ET) was investigated on spatial memory (distance, time, and number of passes in the target quarter), antioxidant status (superoxide dismutase [SOD] and glutathione peroxidase [GPx]), and neurogenic factor levels (vascular endothelial growth factor [VEGF] and brain-derived neurotrophic factor [BDNF]) in male Wistar rats.

Methods

Rats were assigned to a control (CTL) group, ET group, ET+MitoQ group, and a MitoQ group. Rats were trained on a treadmill for 8 weeks, 5 days/week, and 50 min/day. MitoQ (250 μM daily) was administered through drinking water for 8 weeks. Spatial memory (Morris water maze test), gene expression (real-time PCR), protein expression (Western blotting), and antioxidants (ELISA method) were determined.

Results

Distance and number of passes in the target quarter in the ET, MitoQ, and ET+MitoQ groups were higher than in the CTL group (P=0.001). MitoQ+ET had more impact on the abovementioned indices than MitoQ or ET alone. Simultaneous use of MitoQ and ET significantly increased gene and protein expression of VEGF (P=0.0001) and gene expression of BDNF (P=0.004) and Sestrin 2 (SESN2) (P=0.0001) in hippocampal tissue. The expression of VEGF (P=0.007) and SESN2 (P=0.001) was higher in the MitoQ group compared to the CTL group. Tissue GPx levels were increased following all three interventions (P≤0.013) compared to the CTL group while SOD levels remained unchanged in all groups.

Conclusions

The combination of ET and MitoQ has additive effects on spatial memory in rats by modulating parameters that are involved in hippocampal neurogenesis. In addition, MitoQ may have positive effects on the antioxidant defense by improving GPx activity.

Relevance for Patients

Considering the positive effects of MitoQ on improving the memory and the antioxidant defense, it seems that it can play a positive role in improving the diseases associated with memory loss in the long term, and ET along with this supplement can increase the possible positive effects.

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.

ameliorates exhaustive exercise-induced fatigue in mice by suppressing mitophagy in skeletal muscle

The aim of present study was to evaluate the potential effects of Rhodiola crenulata oral liquid (RCOL) on exhaustive exercise (EE)-induced fatigue in mice. Male Institute of Cancer Research mice from five treatment groups (n=10 per group) were orally administered with sterilized water for the Control and EE groups and/or RCOL at doses of 1.02, 3.03 and 6.06 ml/kg/day, once daily for 2 weeks. Anti-fatigue activity was subsequently evaluated by measuring the levels of creatine kinase (CK), lactic acid (LA), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and total anti-oxidative capability (T-AOC). Histopathology was assessed using hematoxylin and eosin staining. Ultrastructures of mitochondria were observed by transmission electron microscopy. Energy supply capacity was assessed using citrate synthase (CS), succinate dehydrogenase (SDH), Na⁺-K⁺-ATPase, and liver and quadriceps glycogen content assays. Expression levels of mRNA and protein associated with mitophagy in the skeletal muscle were measured by reverse transcription-quantitative PCR and western blotting, respectively. RCOL was observed to markedly inhibit fatigue-induced oxidative stress by increasing the activities of SOD, CAT and T-AOC, whilst reducing the accumulation of LA, CK, LDH and MDA. Histological analysis of the quadriceps femoris tissue suggested increased numbers of muscle fibers in the RCOL groups compared with those in the EE group. RCOL administration was found to reverse EE-induced mitochondrial structural damage and alleviated defects inflicted onto the energy supply mechanism by increasing CS, SDH, Na⁺-K⁺-ATPase and glycogen levels. Additionally, RCOL reduced the protein expression of PTEN-induced kinase 1 (PINK1), Parkin, microtubule-associated proteins 1A/1B light chain 3, sequestosome 1 and ubiquitin, whilst lowering the gene expression of PINK1 and Parkin. Taken together, results from the present study clarified the anti-fatigue effect of RCOL, where the underlying mechanism may be associated with increased antioxidant activity, enhanced energy production and the inhibition of mitophagy by suppressing the PINK1/Parkin signaling pathway.

The Benefits of High-Intensity Functional Training Fitness Programs for Military Personnel

INTRODUCTION

High intensity functional training (HIFT) programs are designed to address multiple fitness domains, potentially providing improved physical and mental readiness in a changing operational environment. Programs consistent with HIFT principals such as CrossFit, SEALFIT and the US Marine Corps' High Intensity Tactical Training (HITT) are increasingly popular among military personnel. The goal of HIFT programs is to produce high levels of cardiorespiratory fitness, endurance and strength that exceed those achieved by following current physical activity recommendations.

MATERIALS AND METHODS

Given the investment in and popularity of HIFT in the military, it is important to consider the potential impact of this approach to fitness training for the health of military personnel and their risk of training injury. In a previous report in this journal, we addressed the question of whether HIFT was associated with higher injury rates compared to other exercise programs. We argued that concerns about the injury potential of HIFT exercise programs were not supported by the scientific literature to date, although additional research was needed to directly compare injury rates in approaches such as CrossFit to traditional military fitness programs. In this article we will review the scientific data on the practical, health and fitness benefits of HIFT exercise programs for military populations.

RESULTS

Practical benefits to HIFT exercise programs include shorter training times and volumes, exercises which simulate combat tasks, lower equipment costs, reduced potential for boredom and adaptation as a result of constant variation, less injury potential compared to high volume endurance training, and scalability to all fitness levels and rehabilitation needs. For instance, HIFT training volumes are typically between 25% to nearly 80% less than traditional military fitness programs without reductions in fitness outcomes. HIFT program also provide an impressive range of health benefits such as the promotion of metabolic conditioning and muscular strength, less systemic inflammation or oxidative damage compared to sustained aerobic activity, and promoting general physical preparedness (GPP) for the unpredictable physical demands of combat.

CONCLUSION

Given the unique benefits of HIFT, we recommend that these programs become the standard for military physical training. Despite the promise of HIFT fitness programs, questions remain about implementing these programs in the military context. For instance, no large scale randomized trials comparing traditional military physical training with HIFT programs on both health and injury outcomes have been conducted. Such a trial could identify key elements from both types of programs which should be incorporated in future approaches to military fitness training. Also, research regarding the optimal ways of implementing HIFT to maximize both GPP and combat oriented physical skills is lacking. It is likely that an approach to HIFT training which promotes GPP for all personnel along with specialized elements selected on the basis of individual occupation demands would be maximally disseminable in the military.

Cameroonian professional soccer players and risk of atherosclerosis

Background

Elevated titers of antibodies against oxidized low-density lipoproteins-cholesterol (ox-LDL-Ab) have been reported among professional athletes, paradoxically reflecting an increased risk of developing atherogenic and/or cardiovascular events. This study aimed to determine titers of ox-LDL-Ab in a group of Cameroonian professional soccer players, and evaluate their evolution during part of a competition season as well as the plasmatic antioxidant status to find out if this latter correlates with ox-LDL-Ab .

Methods

We conducted a descriptive cohort study in 2012 including 18 healthy male soccer players. Three samplings were performed in March (T1), May (T2), and July 2012 (T3) to assess the lipid profile, titers of ox-LDL-Ab, and plasmatic concentrations of four antioxidants: the ferric reducing antioxidant power (FRAP), reduced glutathione (GSH), superoxide dismutase (SOD), and uric acid.

Results

Ages ranged from 16 to 28 years with a median (interquartile range) of 19.5 (19–23) years. Total cholesterol, high-density lipoproteins-cholesterol (HDL-C), low-density lipoproteins-cholesterol (LDL-C) and triglycerides varied within normal ranges throughout the three samplings. While total cholesterol and LDL-C titers increased significantly (p = 0.003 and p = 0.006, respectively), triglycerides and HDL-C values varied non-significantly throughout the measurements (p = 0.061 and p = 0.192, respectively). The median ox-LDL-Ab titers were respectively: 653.3 (468.2–838.8) mIU/ml at T1, 777.7 (553.7–1150.7) mIU/ml at T2, and 1037.7 (901.7–1481.5) mIU/ml at T3. Overall, ox-LDL-Ab titers increased significantly from T1 to T3 (p = 0.006). Concomitantly, uric acid and FRAP concentrations decreased significantly (p = 0.001 and p = 0.003, respectively); on the contrary, GSH and SOD values increased, but insignificantly (p = 0.115 and p = 0.110, respectively). There was a positive and significant correlation between ox-LDL-Ab and HDL-C (ρ = 0.519, p = 0.027), and between ox-LDL-Ab and SOD (ρ = 0.504, p = 0.033) at T2. Ox-LDL-Ab values were expected to increase with each new visit (β = 201.1; p = 0.041) and each IU/ml of SOD titers (β = 23.6; p = 0.019).

Conclusion

These Cameroonian professional soccer players exhibited high levels of ox-LDL-Ab reflecting elevated levels of oxidatively-modified LDL-C particles with an increment over time, this being insufficiently counterbalanced by the antioxidant defense mechanisms. As a consequence, they may be at increased atherogenic and cardiovascular risks.

A lifelong competitive training practice attenuates age-related lipid peroxidation

The effect of exercise-induced oxidative stress on health and aging is not clearly explained. This study examined the effects of habitual sport practice, age, and submaximal exercise on the blood markers of oxidative stress, muscle damage, and antioxidant response. Seventy-two healthy men were grouped by their habitual sport practice: inactive (<1.5 h/week), recreational (3-8 h/week), and trained athletes (>8 h/week), and further divided by age: young (18-25 years), adult (40-55 years), and senior (>55 years). Blood samples were collected at rest and after submaximal effort. Hydroperoxides and superoxide dismutase, glutathione peroxidase, and catalase activities were measured by spectrophotometry. Nuclear DNA damage was analyzed by comet assay. The alpha-actin release was analyzed by Western blot. Alpha-tocopherol, retinol, and coenzyme-Q10 were quantified by high-performance liquid chromatography analysis. Data was analyzed through a factorial ANOVA and the Bonferroni post hoc test. Lipid peroxidation increased significantly with age and submaximal effort (p < 0.05). However, the trained athlete group presented lower lipid peroxidation compared with the recreational group (MD = 2.079, SED = 0.58, p = 0.002) and inactive group (MD = 1.979, SED = 0.61, p = 0.005). Trained athletes showed significant higher alpha-actin levels (p < 0.001) than the other groups. Recreational group showed lower nuclear DNA damage than trained athletes (MD = 3.681, SED = 1.28, p = 0.015). Nevertheless, the inactive group presented significantly higher superoxide dismutase and catalase (p < 0.05) than the other groups. Data suggested that habitual competitive training practice could prevent age-related increases of plasma lipid peroxidation, which, according with our results, cannot be entirely attributed to blood antioxidant defense systems.

Effect of Maximal Versus Supra-Maximal Exhausting Race on Lipid Peroxidation, Antioxidant Activity and Muscle-Damage Biomarkers in Long-Distance and Middle-Distance Runners

Background

Exhausting physical exercise increases lipid peroxidation and causes important muscle damages. The human body tries to mitigate these adverse effects by mobilizing its antioxidant defenses.

Objectives

This study aims to investigate the effect of a maximal versus supra-maximal race sustained until exhaustion on lipid peroxidation, antioxidant activity and muscle-damage biomarkers in trained (i.e. long-distance and middle-distance runners) and sedentary subjects.

Materials and Methods

The study has been carried out on 8 middle-distance runners (MDR), 9 long-distance runners (LDR), and 8 sedentary subjects (SS). Each subject has undergone two exhaustive running tests, the first one is an incremental event (VAMEVAL test), the second one is a constant supra-maximal intensity test (limited-time test). Blood samples were collected at rest and immediately after each test.

Results

A significant increase in malondialdehyde (MDA) concentrations was observed in SS and MDR after the VAMEVAL test and in LDR after the Limited-Time test. A significant difference was also observed between LDR and the other two groups after the VAMEVAL test, and between LDR and MDR after the Limited-Time test. Significant modifications, notably, in myoglobin, CK, LDH, IL-6, TNF-α, and TAS were likewise noted but depending on the race-type and the sportive specialty.

Conclusions

Maximal and supra-maximal races induce a significant increase in lipid peroxidation and cause non-negligible inflammation and muscle damage. These effects were relatively related to the physical exercise type and the sportive specialty.

Alterations in redox homeostasis in the elite endurance athlete

BACKGROUND

The production of reactive oxygen (ROS) and nitrogen species (RNS) is a fundamental feature of mammalian physiology, cellular respiration and cell signalling, and essential for muscle function and training adaptation. Aerobic and anaerobic exercise results in alterations in redox homeostasis (ARH) in untrained, trained and well trained athletes. Low to moderate doses of ROS and RNS play a role in muscle adaptation to endurance training, but an overwhelming increase in RNS and ROS may lead to increased cell apoptosis and immunosuppression, fatigued states and underperformance.

OBJECTIVES

The objectives of this systematic review are: (a) to test the hypotheses that ARH occur in elite endurance athletes; following an acute exercise bout, in an endurance race or competition; across a micro-, meso- or macro-training cycle; following a training taper; before, during and after altitude training; in females with amenorrhoea versus eumenorrhoea; and in non-functional over-reaching (NFOR) and overtraining states (OTS); (b) to report any relationship between ARH and training load and ARH and performance; and (c) to apply critical difference values for measures of oxidative stress/ARH to address whether there is any evidence of ARH being of physiological significance (not just statistical) and thus relevant to health and performance in the elite athlete.

METHODS

Electronic databases, Embase, MEDLINE, and SPORTDiscus were searched for relevant articles. Only studies that were observational articles of cross-sectional or longitudinal design, and included elite athletes competing at national or international level in endurance sports were included. Studies had to include biomarkers of ARH; oxidative damage, antioxidant enzymes, antioxidant capacity, and antioxidant vitamins and nutrients in urine, serum, plasma, whole blood, red blood cells (RBCs) and white blood cells (WBCs). A total of 3,057 articles were identified from the electronic searches. Twenty-eight articles met the inclusion criteria and were included in the review.

RESULTS

ARH occurs in elite endurance athletes, after acute exercise, a competition or race, across training phases, and with natural or simulated altitude. A reduction in ARH occurs across the season in elite athletes, with marked variation around intensified training phases, between individuals, and the greatest disturbances (of physiological significance) occurring with live-high-train-low techniques, and in athletes competing. A relationship with ARH and performance and illness exists in elite athletes. There was considerable heterogeneity across the studies for the biomarkers and assays used; the sport; the blood sampling time points; and the phase in the annual training cycle and thus baseline athlete fitness. In addition, there was a consistent lack of reporting of the analytical variability of the assays used to assess ARH.

CONCLUSIONS

The reported biochemical changes around ARH in elite athletes suggest that it may be of value to monitor biomarkers of ARH at rest, pre- and post-simulated performance tests, and before and after training micro- and meso-cycles, and altitude camps, to identify individual tolerance to training loads, potentially allowing the prevention of non-functionally over-reached states and optimisation of the individual training taper and training programme.

The effects of 16 weeks of intensive cycling training on seminal oxidants and antioxidants in male road cyclists

OBJECTIVE

To examine the effects of 16 weeks of intensive cycling training on seminal reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase, and total antioxidant capacity (TAC) in male road cyclists.

DESIGN

Repeated measures design.

SETTING

The Exercise Physiology Laboratory of the Urmia University.

PARTICIPANTS

Twenty-four healthy nonprofessional male road cyclists (aged 17-26 years) participated in this study.

INTERVENTIONS

All subjects participated in 16 weeks of intensive cycling training. The semen samples were collected, respectively, at baseline (T1), immediately (T2), 12 (T3), and 24 (T4) hours after the last training session in week 8; immediately (T5), 12 (T6), and 24 (T7) hours after the last training session in week 16; and 7 (T8) and 30 (T9) days after the last training session in week 16.

MAIN OUTCOME MEASURES

Total antioxidant capacity and SOD were measured by colorimetric assay. The levels of ROS were measured by a chemiluminescence assay. Malondialdehyde levels were measured by thiobarbituric acid reactive substance assay. Catalase was measured by monitoring the initial rate of disappearance of hydrogen peroxide (initial concentration 10 mM) at 240 nm.

RESULTS

The levels of seminal ROS and MDA increased (P < 0.008) and remained high after 30 days of recovery. The levels of seminal SOD, catalase, and TAC decreased (P < 0.008) and remained low after 30 days of recovery (P < 0.008).

CONCLUSIONS

Sixteen weeks of intensive cycling training may have deleterious consequences for spermatozoa and hence may affect sperm healthy parameters in male cyclists.

Correlation between seminal oxidative stress biomarkers and antioxidants with sperm DNA damage in elite athletes and recreationally active men

OBJECTIVE

To evaluate the seminal plasma 8-isoprostane, reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase, total antioxidant capacity (TAC), and levels of sperm DNA fragmentation in elite athletes and recreationally active men.

DESIGN

Prospective design was used for this study.

SETTING

The study was performed in the Exercise Physiology Laboratory of the Urmia University.

PARTICIPANTS

Fifty-six elite athletes and 52 recreationally active men (18-28 years) participated in this study.

INTERVENTION

All subjects had a semen sampling at baseline.

MAIN OUTCOME MEASURES

Total antioxidant capacity and SOD activity were measured by colorimetric assay. Levels of ROS were measured by a chemiluminescence assay. Malondialdehyde levels were measured by thiobarbituric acid reactive substance assay. Catalase activity was measured by monitoring the initial rate of disappearance of hydrogen peroxide. Concentration of free 8-isoprostane was measured by enzyme immunoassay method. Sperm DNA fragmentation was evaluated with the terminal deoxynucleotidyl transferase-mediated fluorescein dUTP nick end-labeling assay.

RESULTS

Recreationally active men have significantly higher levels of body fat, seminal SOD, TAC, and catalase and lower levels of V[Combining Dot Above]O2max, seminal ROS, MDA, and 8-isoprostane and subsequently lower rate of sperm DNA fragmentation when compared with elite athletes (P < 0.001). Significantly negative correlation was observed between sperm DNA fragmentation with body fat, seminal SOD, catalase, and TAC levels (P < 0.001). Significantly positive correlation was observed between sperm DNA fragmentation with V[Combining Dot Above]O2max, seminal 8-isoprostane, ROS, and MDA levels (P < 0.001).

CONCLUSION

Spermatozoa from recreationally active men may be less susceptible to oxidative stress-induced DNA damage and hence infertility.

Protein nitration, lipid peroxidation and DNA damage at high altitude in acclimatized lowlanders and native highlanders: relation with oxygen consumption

Reactive oxygen and nitrogen species have been reported to be increased due to hypobaric hypoxia. It was hypothesized that lowlanders are more susceptible to protein nitration, lipid peroxidation and DNA damage at high altitude than highlanders and formation of these biomarkers may have strong correlation with oxygen consumption. Male volunteers were randomly selected and categorized into 3 groups, i.e. lowlanders at sea level (LL-SL, n=10), lowlanders at an altitude of 4560 m (LL-HA, n=10) and highlanders (HAN, n=10). Volunteers performed maximal aerobic exercise. Resting and post-exercise blood samples were taken at sea level and high altitude. Both resting and maximum oxygen consumption showed positive correlation with stress markers. LL-HA showed increased 3-nitrotyrosine and lipid hydroperoxide than LL-SL at rest. 3-Nitrotyrosine and lipid hydroperoxide increased after exercise in 3 groups, but percentage increase was higher in HAN than LL-SL and LL-HA. LL-SL and HAN showed significant DNA damage after exercise. Results indicate that resting oxygen consumption is positively correlated with nitrosative and oxidative stress markers irrespective of environmental condition and adaptation levels. Lowlanders have shown higher susceptibility to hypoxic insult than highlanders at rest, but when subjected to exercise test, they showed better tolerance to hypoxia than highlanders.

[Oxidative status evaluation in elite karate athletes during training process]

BACKGROUND/AIM

Oxidative stress is a state of disturbed balance between reactive oxygen species (ROS) and reactive nitrogen species (RNS) on the one hand, and antioxidative defense on the other. As a result of oxidative stress we have irreversible changes in cell function leading to pathological tissue changes, development of many diseases and fast aging process. Increased consumption of oxygen during exercise could be the cause of oxidative stress. The aim of the study was to establish oxidative status of elite karate athletes in the state of rest and after the loading, monitoring the parameters of oxidative stress and components of antioxidative defense in a training process.

METHODS

During training process, a group of 30 elite karate athletes was included in the study of prevalence. They were males, from 16 to 30 years of age. The examination was conducted both in resting condition and after the loading. Oxidative status was determined by the level of superoxide anion radical (O2-), hydrogen peroxide (H2O2) as prooxidants, and enzymes of the antioxidant defanse system: superoxide dismutase (SOD) and catalase (CAT).

RESULTS

There was a homogenous group of young athletes of normal weight and fats percentage. A significant decrease of O2- after the load was founded, while the levels of H2O2 was significantly increased. Activity of SOD was not significantly changed after exsercise while that of CAT was significantly increased.

CONCLUSION

In the long run a programmed physical exercise does not lead to oxidative stress, but an excessive physical load may cause its occurrence.

Antioxidant and redox status after maximal aerobic exercise at high altitude in acclimatized lowlanders and native highlanders

Exercise-induced increase in oxygen consumption leads to oxidative stress. On the contrary, hypoxia triggers oxidative stress despite decreased oxygen flux. Therefore, exercise under hypoxia may aggravate oxidative damage. Highlanders are expected to have better antioxidant capacity than lowlanders as a result of adaptation to hypoxia. The present study was undertaken to investigate the effect of exercise on antioxidant system in lowlanders and highlanders at high altitudes (HA). This study was conducted on active male volunteers, randomly selected and categorized into three groups, i.e., lowlanders tested at sea level (LL-SL, n = 35), lowlanders tested at altitude of 4560 m (LL-HA, n = 35) and native highlanders tested (HAN, n = 20) at the same height. Volunteers performed maximal exercise until exhaustion. Blood samples were collected before and after exercise. Both LL-SL and HAN had shown similar VO2max, which was significantly higher than LL-HA. GSH/GSSG ratio significantly increased in LL-SL and decreased in HAN after exercise. With exercise there were a decrease in superoxide dismutase and increase in glutathione peroxidase and catalase activities in HAN. Therefore, the results have suggested that HAN are more susceptible to oxidative stress when subjected to high-intensity exercise than lowlanders. The cumulative effect of higher VO2max and longer duration of exercise in hypoxia may be the reason of higher level of oxidative insult among HAN. Comparatively better management of antioxidant system observed in lowlanders at HA may be explained by the lower VO2max and shorter duration of exercise in hypoxia.