Oral vitamin C and E combination modulates blood lipid peroxidation and antioxidant vitamin levels in maximal exercising basketball players

Recovery Methods in Basketball: A Systematic Review

Although different strategies have been implemented to manage recovery-fatigue status in athletes, there is still a lack of consensus on which recovery protocols have the greatest impact and effectiveness when implemented with basketball players, including both physiological and psychological recovery methods. Thus, the purpose of this systematic review is to: (a) determine which recovery methods attain the greatest benefit in restoring the process of attenuating fatigue and (b) provide sports practitioners with guidelines on how some of the most effective recovery strategies can be used to optimize athletes' recovery and ultimately enhance their performance. Using the PRISMA guidelines, a total of 3931 research reports were obtained through four database searches (i.e., PubMed, Scopus, Cochrane, and Web of Science), from which only 25 met the inclusion and exclusion criteria. The recovery protocols analyzed in this systematic review were: sleep, nutrition, hydration, ergogenic aids, cold-water immersion, compression garments, massage, acupuncture, tapering, mindfulness, and red-light irradiation. The results revealed that all recovery strategies are capable of attenuating fatigue and enhancing recovery in basketball players to a certain degree. However, an individualized approach should be promoted, where a combination of proactive recovery modalities appears to result in the most rapid rates of recovery and athletes' ability to maintain high-level performance. Recovery should be programmed as an integral component of training regimens. Also, cooperation and communication between coaches, players, and the rest of the team staff members are essential in minimizing the risk of non-functional overreaching or injury and optimizing basketball players' on-court performance.

Antioxidants Supplementation During Exercise: Friends or Enemies for Cardiovascular Homeostasis?

Exercise is a preferred strategy for improving cardiac function, especially for patients with cardiovascular diseases. Increasing evidence indicates that oxidative stress is involved in exercise-induced cardioprotection, while the underlying mechanism remains unclear. Furthermore, the effect of antioxidant supplementation during or post-exercise still exists despite divergences. To explore the effect of oxidative stress and antioxidant supplementation on cardiovascular homeostasis during or post-exercise, we take insights into the progress of exercise-induced oxidative stress, antioxidant supplementation, and cardiovascular homeostasis. In particular, antioxidants such as vitamin C or E, gamma-oryzanol, and other natural antioxidants are discussed concerning regulating exercise-associated oxidative stress. Additionally, our present study reviewed and discussed a meta-analysis of antioxidant supplementation during exercise. Overall, we take an insight into the essential biological adaptations in response to exercise and the effects of antioxidant supplementation on cardiac function, which aid us in giving recommendations on antioxidant supplementation for exercisers and exercised people. A better understanding of these issues will broaden our knowledge of exercise physiology.

Effects of Intramuscular Injections of Vitamins AD3E and C in Combination on Fertility, Immunity, and Proteomic and Transcriptomic Analyses of Dairy Cows during Early Gestation

This research aimed to investigate the effects of the intramuscular injection of vitamins AD3E and C in combination immediately before the estrus synchronization program (the Ovsynch program) on conception and pregnancy rates, blood parameters, serum biochemical properties, immune systems, antioxidant parameters, and proteomic and transcriptomic analyses during early gestation in dairy cows. Forty nonlactating multiparous cows were randomly assigned to one of four treatments: (1) C: control with normal saline injection; (2) VAD3E: a single intramuscular injection (I/M) of vitamin AD3E; (3) VAD3EC: injection of both vitamins AD3E and C; (4) VC: a single dose of vitamin C. Blood and serum samples were taken immediately at day 0 (before AI), day 7, and day 14 (after AI for 5 days) from the coccygeal vein. Generally, injections of AD3E and C in combination had no effect on the rate of conception or pregnancy. However, they improved hematological parameters and immune and antioxidant activities. Serum samples were analyzed using LC-MS/MS, and 8190 proteins were identified. Five proteins were successfully validated using the quantitative real-time reverse transcription PCR (qRT-PCR) method. This study found that lymphocyte-specific protein 1 (LSP1, A0A3Q1M894) could be used as a protein biomarker for cows administrated with vitamins AD3E and C.

Ergo-Nutritional Intervention in Basketball: A Systematic Review

Using nutritional supplements is a widespread strategy among basketball players to ensure the appropriate provision of energy and nutrients to avoid certain complaints. Particularly in basketball, there is no consensus on the type, quantity or form of use in which these supplements should be administered. Therefore, the main aim of this systematic review is to highlight the ergo-nutritional aids that may be effective in basketball. A structured search was carried out following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA®) guidelines in the Medline/PubMed and Web of Science, Cochrane Library, and Scopus databases until 31 December 2021; no year restriction was applied to the search strategy. There were no filters applied to the basketball players' level, gender, race, or age to increase the power of the analysis. The results of this systematic review have shown that the effective dose of caffeine to enhance anaerobic performance and the feeling of vigorousness and energy ranges from 3 to 6 mg·kg-1, showing more positive effects when is supplemented 60-75 min before exercise in the morning and in test-based task. On the other hand, vitamin E (ranging from 200 to 268 mg), vitamin D (10,000 IU) and EPA (2 g) may have a potential role in recovery and wellness. The primary limitation of this study is the scarcity of studies related to nutritional supplementation in basketball players. However, a major strength is that this is the first systematic review describing what ergo-nutritional aids may be specifically helpful for basketball. Despite the need for future studies, certain nutritional supplements may have promising advantages for basketball (long-term supplementation of nitrates for recovery), whereas others (β-alanine, sodium bicarbonate, and acute nitrate supplementation) might theoretically be regarded as not interesting for basketball, or even not recommended by the World Anti-Doping Agency (WADA) as bovine colostrum.

The Role of Vitamin C in Two Distinct Physiological States: Physical Activity and Sleep

This paper is a literature overview of the complex relationship between vitamin C and two opposing physiological states, physical activity and sleep. The evidence suggests a clinically important bidirectional association between these two phenomena mediated by different physiological mechanisms. With this in mind, and knowing that both states share a connection with oxidative stress, we discuss the existing body of evidence to answer the question of whether vitamin C supplementation can be beneficial in the context of sleep health and key aspects of physical activity, such as performance, metabolic changes, and antioxidant function. We analyze the effect of ascorbic acid on the main sleep components, sleep duration and quality, focusing on the most common disorders: insomnia, obstructive sleep apnea, and restless legs syndrome. Deeper understanding of those interactions has implications for both public health and clinical practice.

Effect of corticosteroid (triamcinolone acetonide) and chlorhexidin on chemotherapy- induced oxidative stress in buccal mucosa of rats

Oral mucositis (OM) refers to erythematous and ulcerative lesions of the oral mucosa. This pathology can occur by various causes. Cancer therapy is one of the well-known causes of OM such as chemotherapy and/or with radiation therapy. It has been widely mentioned that oxidative stress parameters such as lipid peroxidation (LP) levels increase during cancer process. Glutathione (GSH) is one of the major intracellular enzymes to detoxify oxidant molecules. The aim of this study was to investigate and compare the effects of Triamcinolone Acetonide (TA), a synthetic steroid chlorhexidine (CHX), a chemical antiseptic, on 5- fluorouracil (5-FU), a chemotherapeutic agent and soft abrasion induced OM in buccal mucosa of rats.OM was induced in rats through a combination of 5-FU treatment and mild abrasion of the cheek pouch with a wire brush. Buccal mucosa lipid peroxidation (LP) levels were higher (p< 0.05) in 5-FU group than in control although LP levels were lower (p<0.05) in TA group than in control group. The reduced glutathione levels were lower (p<0.05) in 5-FU group than in the control group although its level was higher (p<0.05) in TA and CHX groups than in the 5-FU group. Glutathione peroxidase activity was also higher (p<0.05) in TA group than the 5- FU group. In histopathological analyses, treatment with TA reduced 5-FU induced inflammatory cell infiltration and ulceration (p<0.001) but not with CHX.In conclusion, we observed that TA and CHX treatment modulated chemotherapy induced oxidative injury in the rat OM. However, only TA histopathologically ameliorated the 5-FU induced OM of rats. These findings suggest that TA is a useful agent for management of experimental oxidative injury and OM caused by the chemotherapy.

Fabrication of Co3O4 NPs-graphene oxide nanocomposites as an efficient catalyst towards oxygen reduction and its catalytic applications

Co₃O₄ nanoparticles-graphene oxide (Co₃O₄ NPs-GO) nanocomposites with good solubility were successfully synthesized and well characterized. As a nanocatalyst with oxidase-mimicking activity, the nanocomposites can catalyze the oxidation of 3',5,5'-tetramethylbenzidine (TMB) with high efficiency. The catalyzing reaction was rapid and no extra H₂O₂ was needed compared with other similar TMB oxidation reactions. The catalyzing reaction mechanism of the system was investigated in detail. And it was demonstrated that the oxygen involved in the reaction came from the oxygen absorbed on the nanocomposites which oxidized TMB. Based on this reaction, a colorimetric system for vitamin C detection in vegetable and fruits was established. Under the optimum conditions, the detection can be achieved within 10 min and a linear relationship in concentration range of 2.5 × 10^-6 to 1.8 × 10^-5 M and 3.4 × 10^-5 to 1.7 × 10^-4 M was obtained with a detection limit of 7.0 × 10^-7 M. The colorimetric system exhibited good selectivity, sensitivity and satisfactory recoveries ranged from 93.1% to 101.1%.

Dietetic-nutritional, physical and physiological recovery methods post-competition in team sports

To a proper recovery, is absolutely necessary to know that athletes with enhanced recovery after maximal exercise are likely to perform better in sports. Recovery strategies are commonly used in team sports despite limited scientific evidence to support their effectiveness in facilitating optimal recovery and the players spend a much greater proportion of their time recovering than they do in training. According to authors, some studies investigated the effect of recovery strategies on physical performance in team sports, lack of experimental studies about the real origin of the fatigue, certify the need for further study this phenomenon. Thus, developing effective methods for helping athletes to recover is deemed essential. Therefore, the aim of this review is provide information for his practical application, based on scientific evidence about recovery in team sports.

Vitamin C attenuates methotrexate-induced oxidative stress in kidney and liver of rats

Like several other anticancer drugs, methotrexate (MTX) causes side effects, such as neuropathic pain, hepatotoxicity, and nephrotoxicity. Abnormal production of reactive oxygen species has been suspected in the pathophysiology of MTX-induced hepatorenal toxicity. Therefore, the aim of this study was to investigate the probable protective role of vitamin C (Vit C) on oxidative stress induced by MTX in the liver and kidney tissues of rats. A total of 32 rats were randomly and equally divided into four groups. The first group served as the control group. The second group received a single dose of 20 mg/kg of MTX intraperitoneally. To demonstrate our hypothesis, the third and the fourth groups received 250 mg/kg of Vit C for 3 days by oral gavage, with or without MTX treatment. At the end of the study, the liver and kidney tissues of the rats were collected and examined using histology. Both the tissues were assayed for malondialdehyde concentration and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities. In hepatic and renal tissues, lipid peroxidation levels were increased, whereas SOD, CAT, and GSH-Px levels were decreased by MTX. All parameters, including CAT levels in hepatic tissue, were significantly restored after the administration of Vit C for 3 days. Similar to the biochemical findings, evidence of oxidative damage was examined in both types of tissues by histopathological examination. From the results of this study, we were able to observe that Vit C administration modulates the antioxidant redox system and reduces the renal and hepatic oxidative stress induced by MTX. Vit C can ameliorate the toxic effect of MTX in liver and kidney tissues of rat.

Effect of a corticosteroid (triamcinolone) and chlorhexidine on chemotherapy-induced oxidative stress in the buccal mucosa of rats

Oral mucositis manifests as erythematous and ulcerative lesions of the oral mucosa. Among its various causes, cancer treatment (e.g., chemotherapy with or without radiation therapy) is one of the more well known. It has been widely mentioned that oxidative stress parameters such as lipid peroxidation levels increase during the cancer process. Glutathione is one of the major intracellular enzymes used to detoxify oxidant molecules; it exists in both a reduced and oxidized state. Reduced glutathione is used as a substrate to synthesize glutathione peroxidase. We conducted a study to investigate and compare the effects of triamcinolone (a synthetic steroid) and chlorhexidine (a chemical antiseptic) on 5-fluorouracil (5-FU; a chemotherapeutic agent)-induced oral mucositis in the buccal mucosa of 36 rats. Oral mucositis was induced through a combination of 5-FU treatment and mild abrasion of the cheek pouch with a wire brush. The rats were treated with one of four regimens: saline placebo (group I), 5-FU only (group II), 5-FU plus triamcinolone (group III), and 5-FU plus chlorhexidine (group IV). Three rats in the triamcinolone group died of unknown causes on days 7 and 8, and 3 rats in the chlorhexidine group died on days 7 and 9. On day 9, the remaining 30 rats were sacrificed and examined. Buccal mucosa lipid peroxidation levels were significantly higher in the 5-FU-only group than in the control group and significantly higher in the control group than in the triamcinolone group (p < 0.05 for both). Levels of reduced glutathione were significantly lower in the 5-FU-only group than in both the triamcinolone group and the chlorhexidine group (p < 0.05). Glutathione peroxidase activity was significantly higher in the triamcinolone group than in the 5-FU-only group (p < 0.01). Histopathologic analysis revealed that treatment with triamcinolone significantly reduced 5-FU-induced inflammatory cell infiltration and ulceration (p < 0.001); no such reduction was seen with chlorhexidine. In conclusion, we observed that triamcinolone and chlorhexidine treatment modulated chemotherapy-induced oxidative injury in rat oral mucositis. However, only triamcinolone histopathologically ameliorated 5-FU-induced oral mucositis. These findings suggest that triamcinolone is a useful agent for the management of experimental oxidative injury and oral mucositis caused by 5-FU chemotherapy.

Evidence-based post-exercise recovery strategies in basketball

Basketball can be described as a moderate-to-long duration exercise including repeated bouts of high-intensity activity interspersed with periods of low to moderate active recovery or passive rest. A match is characterized by repeated explosive activities, such as sprints, jumps, shuffles and rapid changes in direction. In top-level modern basketball, players are frequently required to play consecutive matches with limited time to recover. To ensure adequate recovery after any basketball activity (i.e., match or training), it is necessary to know the type of fatigue induced and, if possible, its underlying mechanisms. Despite limited scientific evidence to support their effectiveness in facilitating optimal recovery, certain recovery strategies are commonly utilized in basketball. It is particularly important to optimize recovery because players spend a much greater proportion of their time recovering than they do in training. Therefore, the main aim of this report is to facilitate useful information that may lead to practical application, based on the scientific evidence and applied knowledge specifically in basketball.

Control of antioxidant supplementation through interview is not appropriate in oxidative-stress sport studies: Analytical confirmation should be required

OBJECTIVE

Controlling antioxidant supplementation in athletes involved in studies related to oxidative stress and muscle damage is the key to ensure results. The aim of this study was to confirm through high-performance liquid chromatography (HPLC) analysis whether well-trained individuals lied during a personal interview when asked if they were taking supplements with antioxidants, and how this could affect oxidative stress, muscle damage, and antioxidant response.

METHODS

A total of 94 men, well trained in endurance sports, volunteered in this study. They denied taking any antioxidant supplementation at initial interview. After a HPLC analysis, abnormal α-tocopherol concentrations were detected, probably due to a hidden antioxidant supplementation. Participants were classified into two groups: no evidence of antioxidant supplementation (NS group = α-tocopherol values <80 nmol/mL; n = 75) and evidence of antioxidant supplementation (S group = α-tocopherol values >80 nmol/mL; n = 19). Lipid peroxidation, muscle damage, antioxidant enzyme activity, and nonenzymatic antioxidant content were analyzed according to this classification. Statistical comparisons were performed using Student's t test.

RESULTS

The α-tocopherol concentrations were significantly higher in the S group than in the NS group (MD = 725.01 ± 39.01 nmol/mL; P = 0.001). The S group showed a trend toward lower hydroperoxides than the NS group (MD = 1.19 ± 0.72 nmol/mL; P = 0.071). The S group showed significantly lower catalase activity than the NS group (MD = 0.10 ± 0.02-seg-1 mg-1; P < 0.01). Skeletal muscle damage markers did not differ between experimental groups.

CONCLUSIONS

Data from the present study reveal that 20% of participants lied in the exclusion criteria of antioxidant supplementation in a personal interview, as they showed high plasmatic α-tocopherol concentrations after HPLC verification. Catalase activity seems to be affected by high α-tocopherol plasma levels. Therefore, we strongly recommend the HPLC analysis as a necessary tool to verify the antioxidant intake and preserve results in studies linking oxidative stress and sport.

Fluorescence probe for the convenient and sensitive detection of ascorbic acid

Ascorbic acid is an important antioxidant that plays an essential role in the biosynthesis of numerous bioactive substances. The detection of ascorbic acid has traditionally been achieved using high-performance liquid chromatography and absorption spectrophotometry assays. However, the development of fluorescence probes for this purpose is highly desired because they provide a much more convenient and highly sensitive technique for the detection of this material. OFF-ON-type fluorescent probes have been developed for the detection of non-fluorescent compounds. Photo-induced electron transfer and fluorescence resonance energy transfer are the two main fluorescence quenching mechanisms for the detection of ascorbic acid, and several fluorescence probes have been reported based on redox-responsive metals and quantum dots. Profluorescent nitroxide compounds have also been developed as non-metal organic fluorescence probes for ascorbic acid. These nitroxide systems have a stable unpaired electron and can therefore react with ascorbic acid and a strong fluorescence quencher. Furthermore, recent synthetic advances have allowed for the synthesis of α-substituted nitroxides with varying levels of reactivity towards ascorbic acid. In this review, we have discussed the design strategies used for the preparation of fluorescent probes for ascorbic acid, with particular emphasis on profluorescent nitroxides, which are unique radical-based redox-active fluorescent probes.

Fluorescence probe for the convenient and sensitive detection of ascorbic acid

Ascorbic acid is an important antioxidant that plays an essential role in the biosynthesis of numerous bioactive substances. The detection of ascorbic acid has traditionally been achieved using high-performance liquid chromatography and absorption spectrophotometry assays. However, the development of fluorescence probes for this purpose is highly desired because they provide a much more convenient and highly sensitive technique for the detection of this material. OFF-ON-type fluorescent probes have been developed for the detection of non-fluorescent compounds. Photo-induced electron transfer and fluorescence resonance energy transfer are the two main fluorescence quenching mechanisms for the detection of ascorbic acid, and several fluorescence probes have been reported based on redox-responsive metals and quantum dots. Profluorescent nitroxide compounds have also been developed as non-metal organic fluorescence probes for ascorbic acid. These nitroxide systems have a stable unpaired electron and can therefore react with ascorbic acid and a strong fluorescence quencher. Furthermore, recent synthetic advances have allowed for the synthesis of α-substituted nitroxides with varying levels of reactivity towards ascorbic acid. In this review, we have discussed the design strategies used for the preparation of fluorescent probes for ascorbic acid, with particular emphasis on profluorescent nitroxides, which are unique radical-based redox-active fluorescent probes.

Effect of lycopene-enriched olive and argan oils upon lipid serum parameters in Wistar rats

BACKGROUND

Lycopene has the highest antioxidant activity within carotenoids and is an effective free radical scavenger. Virgin olive oil (VOO) and argan oil (AO) contain trace amounts of a wide variety of phytochemicals which have desirable nutritional properties. The present study intended to assess the effect of various dietary VOO and AO in combination with lycopene consumption on serum biochemical parameters, including total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglycerides (TGs) and phospholipids, as well as on hepatosomatic index (HSI) of rats.

RESULTS

Results showed that ingestion of VOO and AO diminished TC, LDL-C, TGs and phospholipid levels, whereas the HDL-C levels augmented in all the groups assayed. The enrichment of VOO and AO with lycopene improved the beneficial effects derived from the consumption of both oils on serum biochemical parameters. A decrease in body weight gain and HSI was detected after the consumption of lycopene-enriched oils.

CONCLUSION

These findings suggest that the inclusion of lycopene in VOO and AO may be used as a natural tool to fight against hyperlipidaemic and hypercholesterolaemic-derived disorders.

Alpha lipoic acid attenuates inflammatory response during extracorporeal circulation

Aim

Extracorporeal circulation (ECC) of blood during cardiopulmonary surgery has been shown to stimulate various pro-inflammatory molecules such as cytokines and chemokines. The biochemical oxidation/reduction pathways of a-lipoic acid suggest that it may have antioxidant properties.

Methods

In this study we aimed to evaluate only patients with coronary heart disease and those planned for coronary artery bypass graft operation. Blood samples were obtained from the patients before the operation (P1) and one (P2), four (P3), 24 (P4) and 48 hours (P5) after administration of a-lipoic acid (LA). The patients were divided into two groups, control and LA treatment group. Levels of interleukin-6 (IL-6) and -8 (IL-8), complement 3 (C3) and 4 (C4), anti-streptolysin (ASO), C-reactive protein (CRP) and haptoglobin were assessed in the blood samples.

Results

Cytokine IL-6 and IL-8 levels were significantly higher after surgery. Compared with the control groups, LA significantly decreased IL-6 and IL-8 levels in a time-dependent manner. CRP levels did not show significant variation in the first three time periods. CRP levels were higher after surgery, especially in the later periods. These results demonstrate that CRP formation depends on cytokine release. C3 and C4 levels were significantly higher after surgery than in the pre-operative period. LA treatment decreased C3 and C4 levels. Therefore, LA administration may be useful for the treatment of diseases and processes where excessive cytokine release could cause oxidative damage.

Conclusions

Our findings suggest a possible benefit of using LA during cardiac surgery to reduce cytokine levels.

Redox status and antioxidant response in professional cyclists during training

The aim of this study was to investigate whether different phases of training affect oxidative stress and antioxidant defences in professional cyclists. Ten professional cyclists, aged 21.8 ± 2.5 years, were enrolled in the study. They were classified into two groups of five athletes each one with similar nutritional intake excepting for the overload of vitamin C (1000 mg day(-1)) and E (400 mg day(-1)) supplementation in one of them. The cyclists of both groups performed the same exercise design, consisting of hard, tapering and recovery training periods. Total antioxidant capacity (TAC) of the diet, plasma oxygen radical absorption capacity (ORAC), lipid peroxidation (LPO), DNA damage (8-OHdG) and erythrocyte glutathione disulfide/glutathione ratio (GSSG:GSH(-1)) were measured. During the intense exercise trainings, the cyclists without vitamin supplements had the TAC of diet significantly lower than the supplemented group. Plasma ORAC, LPO and 8-OHdG were similar in both groups of athletes. Athletes with supplements had a basal LPO:ORAC(-1) ratio lower than that without supplements, but this ratio converged to the same level at the end of the training in both groups of cyclists. Both groups of cyclists showed similar changes in GSSG:GSH(-1) ratio and in GSSG and GSH levels along the study. The data suggest that well-trained athletes with suitable ultra-endurance training volume and intensity do not require antioxidant vitamin supplements to adapt their endogenous antioxidant defenses to exercise-induced ROS.

Influence of training frequency on serum concentrations of some essential trace elements and electrolytes in male swimmers

Elemental fluctuations during physical performances have been a point of interest. This study was designed to investigate the effect of swimming frequency on serum concentrations of some trace elements (chromium, iron, copper, zinc, selenium) and electrolytes (sodium, magnesium, potassium, calcium). Three groups of different-level male swimmers were included in the study, as elite swimmers (n = 14), amateur swimmers (n = 11), and sedentary individuals (n = 10). Elite and amateur swimmer groups followed a 3-week training program. At the end of the period, all volunteers were subjected to a controlled swimming test, and blood samples were collected at the beginning of (pre-test), immediately after (post-test), and 1 h after this activity. Element concentrations were determined by inductively coupled plasma mass spectrometry using a dilute and shoot procedure. Apart from the swimming test applied, pre-test calcium and potassium levels were higher in elite swimmers compared to amateurs and controls. The difference in pre-test levels of these elements can be associated with adaptive mechanisms emerged by the frequent training. Regarding the test applied, changes in magnesium, calcium, copper, zinc, and selenium levels exhibited a common pattern in all study groups, with higher post-test serum concentrations. Another point of note was a drop of copper, zinc, and selenium levels at 1 h after the test in elite swimmers. The decrease in serum zinc was also observed in the other groups. Results highlight the value of regular control of elemental status to provide insight into transient effects and deficiencies.

Metabolic effects of a caffeinated sports drink consumed during a soccer match

The purpose of this study was to verify the effect of the intake of a caffeinated sport drink (CAFD) compared to a commercial carbohydrate drink (CHOD) on biochemical parameters and rate of perception exertion in youth soccer players. The experiment was setup in a double-blind crossover design where athletes consumed 5mL.Kg-1 body weight (BW) before the game and 3mL.Kg-1 BW every 15 minutes during the game. Intake of the CAFD resulted in increased blood glucose (BG) and blood lactate (BL) levels and average of maximum heart rate compared to consumption of the CHOD (p = 0.01). No difference was observed in the other variables. CAFD promoted greater plasmatic concentration of BG and BL compared with the CHOD. The CAFD did not increase the mobilization of free fatty acids, did not alter the plasma potassium concentration and was not able to reduce subjective perceived exertion.

Efeitos do ácido ascórbico nos biomarcadores de estresse oxidativo em nadadores de elite

OBJETIVO: O objetivo do estudo foi verificar os efeitos da oferta de vitamina C através de um suplemento alimentar e dieta rica em ácido ascórbico (AA) no estresse oxidativo induzido pelo exercício. MÉTODOS: A amostra foi composta por 13 nadadores de elite (seis homens e sete mulheres) com idades entre 18 e 26 anos. Os mesmos atletas foram submetidos a sessão de exercício agudo em três fases, com diferentes tratamentos: controle (C), dieta rica em AA (D) e suplemento de AA (S), nas quais amostras de sangue foram colhidas antes, imediatamente após e 24 horas depois do exercício. Para comparação entre as fases e etapas foi utilizado o modelo de regressão linear com efeitos mistos. RESULTADOS: O consumo alimentar habitual de antioxidantes não foi diferente entre as fases, apenas a ingestão de AA foi maior na fase D e S em relação à fase C. O uso de dieta rica em AA favoreceu uma menor peroxidação lipídica, devido aos menores valores de hidroperóxidos lipídicos (FOX), diminuição da peroxidação após exercício, pela diminuição de substâncias reativas ao ácido tiobarbitúrico (TBARS) e aumento dos níveis de vitamina C logo após o exercício. O uso de suplemento de AA também conteve a peroxidação lipídica após exercício e aumentou o poder antioxidante, devido aos maiores níveis de glutationa reduzida (GSH). Sem adição de AA os nadadores tiveram um maior dano hepático, pois apresentaram maiores níveis de transaminase-glutâmico-oxalacética (TGO), menores níveis de antioxidantes (vitamina C e GSH) e aumento do ácido úrico. CONCLUSÃO: Assim, as mudanças observadas com a adição de AA à dieta de nadadores sugerem um importante papel deste micronutriente na defesa contra o estresse oxidativo induzido pelo exercício.

The effect of iron-vitamin C co-supplementation on biomarkers of oxidative stress in iron-deficient female youth

There is no study that assessed the effect of co-supplementation of iron and vitamin C on biomarkers of oxidative stress in non-anemic iron-deficient females. We investigated the effects of iron vs. iron + vitamin C co-supplementation on biomarkers of oxidative stress in iron-deficient girls. In a double-blind randomized controlled clinical trial, performed among 60 non-anemic iron-deficient girls, participants were randomly assigned to receive either 50 mg/day elemental iron supplements or 50 mg/day elemental iron + 500 mg/day ascorbic acid for 12 weeks. Fasting blood samples were taken at baseline, weeks 6 and 12 for assessment of biomarkers of oxidative stress. Compared with the baseline levels, both iron and iron + vitamin C supplementation resulted in a significant reduction in serum malondialdehyde (MDA) levels (P time < 0.001) and remarkable elevation in serum total antioxidant capacity (TAC; P time < 0.001) and vitamin C levels (P time = 0.001); however, comparing the two groups we failed to find an additional effect of iron + vitamin C supplementation to that of iron alone on serum TAC and MDA levels (P group was not statistically significant). Iron + vitamin C supplementation influenced serum vitamin C levels much more than that by iron alone (P group < 0.01). We also found a significant interaction term between time and group about serum vitamin C levels while this interaction was not significant about serum TAC and MDA levels. In conclusion, we found that iron supplementation with/without vitamin C improve biomarkers of oxidative stress among non-anemic iron-deficient females and may strengthen the antioxidant defense system by decreasing reactive oxygen species. Co-supplementation of iron + vitamin C has no further effect on oxidative stress compared with iron alone.

Antioxidant vitamins C and E supplementation increases markers of haemolysis in sickle cell anaemia patients: a randomized, double-blind, placebo-controlled trial

Erythrocytes from sickle cell anaemia (SCA) patients continuously produce larger amounts of pro-oxidants than normal cells. Oxidative stress seems to primarily affect the membrane and results in haemolysis. The use of antioxidants in vitro reduces the generation of pro-oxidants. To evaluate the impact of vitamins C (VitC) and E (VitE) supplementation in SCA patients, patients over 18 years were randomly assigned to receive VitC 1400 mg + VitE 800 mg per day or placebo orally for 180 d. Eighty-three patients were enrolled (44 vitamins, 39 placebo), median age 27 (18-68) years, 64% female. There were no significant differences between the two groups regarding clinical complications or baseline laboratorial tests. Sixty percent of the patients were VitC deficient, 70% were VitE deficient. Supplementation significantly increased serum VitC and E. However, no significant changes in haemoglobin levels were observed, and, unexpectedly, there was a significant increase in haemolytic markers with vitamin supplementation. In conclusion, VitC + VitE supplementation did not improve anaemia and, surprisingly, increased markers of haemolysis in patients with SCA and S-β(0) -thalassaemia. The exact mechanisms to explain this findings and their clinical significance remain to be determined.

Carnitine supplementation effects on nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress

Previous studies have demonstrated that exercise stress increases oxidative stress in rats. However, antioxidant supplement therapy effects on reactive oxygen substances are conflicting. We evaluated the effects of carnitine on renal nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. Wistar rats were divided into 3 groups: (a) control group (not submitted to exercise stress), (b) exercise stress group, and (c) exercise stress and carnitine group. The rats from group 3 were treated with gavage administration of 1 ml of carnitine (5 mg·kg⁻¹) for 7 consecutive days. The animals from groups 2 and 3 were submitted to a bout of swimming exhaustive exercise stress. Kidney samples were analyzed for reactive substances to thiobarbituric acid by malondialdehyde (MDA), reduced glutathione (GSH), and vitamin-E levels. Carnitine treatment attenuated MDA increase caused by exercise stress (1: 0.16 ± 0.02 vs. 2: 0.34 ± 0.07 vs. 3: 0.1 ± 0.01 mmmol per milligram of protein; p < 0.0001). It also increased the renal levels of GSH (1: 23 ± 4 vs. 2: 23 ± 2 vs. 3: 58 ± 9 μmol per gram of protein; p < 0.0001); however, it did not change renal vitamin E (1: 24 ± 5 vs. 2: 27 ± 1 vs. 3: 28 ± 5 μM per gram of tissue; p < 0.001). In conclusion, carnitine improved oxidative stress and partially improved the nonenzymatic antioxidant activity in young rats submitted to exhaustive exercise stress.

Rapid and convenient detection of ascorbic acid using a fluorescent nitroxide switch

Ascorbic acid is a small-molecule reductant with multiple functions in vivo. Reducing ascorbic acid intake leads to a lack of hydroxylation of prolines and lysines, causing a looser triple helix and resulting in scurvy. Ascorbic acid also acts as an antioxidant to prevent oxidative stress. Because ascorbic acid is related to disease states, rapid and convenient detection of ascorbic acid should be useful in diagnosis. Nitroxide is reduced to the corresponding hydroxylamine by ascorbic acid and a sensitive and novel approach to its detection employs covalent coupling of nitroxide with a fluorophore, leading to intramolecular quenching of fluorescence emission by electron-exchange interactions. Here, we developed a new fluorophore-nitroxide probe, Naph-DiPy nitroxide, for ascorbic acid. Naph-DiPy nitroxide rapidly reacted with ascorbic acid and showed fluorescence enhancement, but not in response to other reductants or reactive oxygen species. To confirm the practical usefulness of the fluorophore-nitroxide probe, we demonstrated the use of Naph-DiPy nitroxide for the measurement of ascorbic acid in the plasma of osteogenic disorder Shionogi rats when fed an ascorbic acid-deficient diet. The results suggest that this novel fluorophore-nitroxide probe could sensitively and easily detect ascorbic acid and be useful as a tool for the diagnosis of disease states.

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.

Effects of vitamin E supplementation on renal non-enzymatic antioxidants in young rats submitted to exhaustive exercise stress

BACKGROUND

Exercise stress was shown to increase oxidative stress in rats. It lacks reports of increased protection afforded by dietary antioxidant supplements against ROS production during exercise stress. We evaluated the effects of vitamin E supplementation on renal non-enzymatic antioxidants in young rats submitted to exhaustive exercise stress.

METHODS

Wistar rats were divided into three groups: 1) control group; 2) exercise stress group and; 3) exercise stress + Vitamin E group. Rats from the group 3 were treated with gavage administration of 1 mL of Vitamin E (5 mg/kg) for seven consecutive days. Animals from groups 2 and 3 were submitted to a bout of swimming exhaustive exercise stress. Kidney samples were analyzed for Thiobarbituric Acid Reactive Substances to (TBARS) by malondialdehyde (MDA), reduced glutathione (GSH) and vitamin-E levels.

RESULTS

The group treated with vitamin E and submitted to exercise stress presented the lowest levels of renal MDA (1: 0.16+0.02 mmmol/mgprot vs. 2: 0.34+0.07 mmmol/mgprot vs. 3: 0.1+0.01 mmmol/mgprot; p < 0.0001), the highest levels of renal GSH (1: 23+4 μmol/gprot vs. 2: 23+2 μmol/gprot vs. 3: 58+9 μmol/gprot; p < 0.0001) and the highest levels of renal vitamin E (1: 24+6 μM/gtissue vs. 2: 28+2 μM/gtissue vs. 3: 43+4 μM/gtissue; p < 0.001).

CONCLUSION

Vitamin E supplementation improved non-enzymatic antioxidant activity in young rats submitted to exhaustive exercise stress.

ROS-induced ROS release in vascular biology: redox-redox signaling

The involvement of reactive oxygen species (ROS) in regulating vascular function both in normal vessels and as part of an adaptive response during disease has been intensively studied. From the recognition that ROS serve as important signaling molecules has emerged multiple lines of evidence that there is a functional connectivity between intracellular sites of ROS production. This cross talk has been termed ROS-induced ROS release (RIRR) and is supported by a variety of observations showing that RIRR is a common mechanism for ROS amplification and regional ROS generation. The compartmentalization of ROS production within a cell is critical to its signaling function and is facilitated by microlocalization of specific scavengers. This review will provide descriptions and examples of important mechanisms of RIRR.

Pomegranate seed extract attenuates chemotherapy-induced acute nephrotoxicity and hepatotoxicity in rats

Cisplatin (CDDP), one of the most active cytotoxic agents against cancer, has adverse side effects, such as nephrotoxicity and hepatotoxicity. The present study was designed to investigate the potential protective effect of pomegranate seed extract (PSE) against oxidative stress caused by CDDP injury of the kidneys and liver by measuring tissue biochemical and antioxidant variables and immunohistochemically testing caspase-3-positive cells. Twenty-four Sprague-Dawley rats were divided into 4 groups: control; CDDP: injected intraperitoneally with CDDP (7 mg/kg body weight, single dose); PSE: treated for 15 consecutive days by gavage with PSE (300 mg/kg per day); and PSE+CDDP: treated by gavage with PSE 15 days after a single injection of CDDP. The degree of protection against CDDP injury afforded by PSE was evaluated by determining the levels of malondialdehyde as a measure of lipid peroxidation. The levels of glutathione and activities of glutathione peroxidase, glutathione S-transferase, and superoxide dismutase were estimated from liver and kidney homogenates; the liver and kidney were also histologically examined. PSE elicited a significant protective effect toward liver and kidney by decreasing the level of lipid peroxidation; elevating the levels of glutathione S-transferase; and increasing the activities of glutathione peroxidase, glutathione S-transferase, and superoxide dismutase. These biochemical observations were supported by immunohistochemical findings and suggested that PSE significantly attenuated nephrotoxicity and hepatotoxicity by the way of its antioxidant, radical-scavenging, and antiapoptotic effects. This PSE extract could be used as a dietary supplement in patients receiving chemotherapy medications.