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Effects of Daily Astaxanthin and L-Carnitine Supplementation for Exercise-Induced Muscle Damage in Training Thoroughbred Horses
Abstract
The effects of dietary supplementation with astaxanthin and L-carnitine on serum markers and clinical incidence rate of exercise-induced muscle damage were studied in training horses. Sixty-three healthy Thoroughbred horses were randomly assigned to two groups and received the same base diet and exercise training throughout this study. The supplement (supp.) group (n = 31) received daily supplementation with astaxanthin (75 mg) and L-carnitine (3,000 mg) for 8 weeks, and the control (cont.) group (n = 32) received no supplementation. Blood samples were collected after high-intensity exercise training at 5 weeks before supplementation, 3 days (3d), and 8 weeks (8w) after the start of the supplementation. The blood samples were analyzed for creatine kinase (CK) activity and lactate dehydrogenase isoenzyme-5 (LDH-5), and a retrospective study was carried out by analyzing medical records for symptoms of exercise-induced muscle damage in both groups. Five horses (two of supp. group and three of cont. group) were excluded from this study for other disease. In the cont. group, CK activity at 8w was significantly increased compared with 3d, whereas the supp. group showed no significant change. After 8w, the CK activity of the supp. group was significantly lower than that of the cont. group. Additionally, the LDH-5 concentration of the supp. group also tended to be lower as compared with that of the cont. group. The incidence rate of exercise-induced muscle damage was significantly lower in the supp. group compared with the cont. group. These results suggest that continuous dietary administration of astaxanthin and L-carnitine attenuates exercise-induced muscle damage in horses.
... Astaxanthin is recommended as a supplement for sport horses by several equine web portals, but the hypothesis regarding its effect has been studied only indirectly, in combination with L-carnitine, based on the activities of creatine kinase (CK) and lactate dehydrogenase isoenzyme-5 (LDH-5) in blood 32 . Direct effect of astaxanthin on oxidative stress in horses has never been studied. ...
... Moreover, the recommended dosage of commercially available supplements is wide. Sato et al. 32 administered to the horses supplement that contained 37.5 mg of astaxanthin, however, the manufacturer of AstaReal ® mentioned the studies with 75 mg and 30-100 mg doses 35 and other company recommended much higher dose: 937.5 mg twice daily 36 . Astaxanthin has been proven to be safe and beneficial at very high doses: 50 mg/kg and even 200 mg/kg in rats 37,38 . ...
... restitution. Compared to Sato et al. 32 findings, in our study the antioxidant effect of astaxanthin supplementation was observed earlier, after 4 weeks of supplementation and then remained at the similar level till the end of the observation period. ...
Astaxanthin due to its strong antioxidant activity is believed to reduce oxidative stress and therefore is considered as feed additive in pathological conditions and also for the athletes. It is promoted by several equine web portals, however, data supporting that concept in horses is limited. Thus, the aim of this study was to evaluate the effect of astaxanthin supplementation on the parameters of oxidative status in 3 years old, racing Arabian horses during long term observation and the changes related to a single training session of high intensity. Six horses were supplemented with astaxanthin at a dose of 0.52–0.58 mg/kg BW and 7 received no supplementation. Astaxanthin supplementation resulted in the increase in total antioxidant status by 31.5%, accompanied by decreases in the amount of total thiobarbituric acid-reactive substances -TBARS and glutathione reductases - GR values by 34.5% and 45.4%, respectively, after 1 month and this effect persisted until the end of the observation. After individual training session the activities of glutathione peroxidases and GR were lower by 69% and 46%, respectively, and TBARS lower by 38% in supplemented horses. These results directly confirmed the beneficial effects of astaxanthin supplementation on the antioxidant status of race horses. Astaxanthin partially counterbalance the training-related oxidative stress, save the horse natural antioxidant defense, and shift the redox status towards a more reducing environment. At the same time, exercise-induced reactive oxygen species production at certain level was maintained and so that contributed to training progress.
... When subjected to intense exercise, the animal body tends to consume more oxygen (O 2 ) (SATO et al., 2015). Oxygen molecules have a strong tendency to receive an electron, due to their electron configuration, forming the superoxide (O 2 -) radical. ...
... Oxygen molecules have a strong tendency to receive an electron, due to their electron configuration, forming the superoxide (O 2 -) radical. This radical, by receiving one more electron and two hydrogen atoms, through a process called dismutation, forms hydrogen peroxide (H 2 O 2 ) (SCHNEIDER & OLIVEIRA, 2004), increasing the production of free radicals in the musculature, causing oxidative stress. From this reaction, accelerated muscle fatigue occurs, causing damage to muscle fibers (SATO et al., 2015). ...
... This radical, by receiving one more electron and two hydrogen atoms, through a process called dismutation, forms hydrogen peroxide (H 2 O 2 ) (SCHNEIDER & OLIVEIRA, 2004), increasing the production of free radicals in the musculature, causing oxidative stress. From this reaction, accelerated muscle fatigue occurs, causing damage to muscle fibers (SATO et al., 2015). Some enzymes are released into the bloodstream, after exercise, when muscle fibers are damaged. ...
The objective of this review is to discuss aspects of the practice of endurance racing and alternatives to reduce oxidative stress in horses. Characterized by a high aerobic effort and requirement of the organic systems for maintenance of homeostasis, the endurance race is a form of sport for horses that demands great attention to the physical preparation of these animals and must be progressive, paying attention to the physiological parameters to evaluate the adaptation of the organism. To begin the preparation, the animals must be at least five years old and the duration can be on average of three years. Another factor that may be detrimental to the health and well-being of competing horses is the occurrence of oxidative stress, due to the accumulation of free radicals in the tissues, generating post-exercise muscle injuries. Antioxidant supplementation has been an alternative to this disorder. Several studies using compounds rich in antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), demonstrate positive effects on antioxidant status, markers of oxidative stress and muscle enzymes, which may represent an improvement in performance during the exercise and recovery of animals destined to the practice of equestrian sports. Therefore, a correct physical preparation becomes crucial and antioxidant supplementation may be used to maintain the health and well-being of horses destined to the equestrian endurance practice.
... Additionally, the use of ATX is widespread in injured, immune-compromised, and allergic horses [19][20][21], as well as horses with muscle disorders such as tying-up syndrome or polysaccharide storage myopathy (PSSM). In racehorses, antioxidants have been proposed as supplements reducing inflammation in the musculoskeletal system [22,23] and airways [24]. Due to the strong antioxidant properties of ATX and the fact that the mechanism by which it limits exercise-induced muscle damage has been recognized in mice [25], it is widely considered as a supplement for human athletes [12] and seems to be a perfect candidate also for horses. ...
... However, the rapidly increasing popularity of ATX in horses is scarcely supported by scientific evidence. It has been shown that long-term supplementation with ATX and L-carnitine is associated with lower serum creatinine kinase (CK) activity and a tendency toward lower lactate dehydrogenase isoenzyme-5 (LDH-5) activity, suggesting these compounds may reduce the rate of exercise-induced muscle damage [22]. Current anti-inflammatory recommendations for horses are based only on in vitro studies, rodent studies, and observations in humans [26][27][28][29]. ...
This study aimed to evaluate the oral supplementation of astaxanthin (ATX) on inflammatory markers in 3-year-old Arabian racehorses. Despite the recognized antioxidant and anti-inflammatory properties of ATX observed in vitro in rodent models and in human athletes, the effects in equine subjects remain unknown. This study involved a controlled trial with 14 horses receiving either ATX (six horses) or a placebo (eight horses), monitored over four months of race training. Inflammatory cytokines: TNFα, IFNγ, IL-6, IL-10, and prostaglandin E (PGE), were measured monthly to assess the impact of ATX on the inflammatory response. The results indicated no significant differences in measured parameters between the ATX and the control group during the study. However, a significant time-dependent decrease in TNFα and IFNγ levels (p = 0.001) was observed in both groups, suggesting that regular training naturally modulates inflammatory responses. Moreover, positive correlations were noted between TNFα and IFNγ (p < 0.001) in the early phase of the study and between IL-6 and IL-10 (p = 0.008) in the later phase. Hematological parameters remained stable and within reference ranges, indicating no adverse effects of ATX supplementation. Performance metrics, including the number of races completed and wins, showed no significant differences between groups, suggesting that ATX did not enhance athletic performance under the study conditions. Overall, while ATX supplementation affected neither cytokine levels nor performance in Arabian racehorses, the natural anti-inflammatory effects of regular training were evident. Further research is needed to explore potential benefits of ATX supplementation under different conditions, such as in horses with subclinical inflammation or varying training regimens, to fully clarify its role and applications in equine sports medicine.
... to newborn lambs, the amount of BHT (Butylated hydroxytoluene) that accumulated in the flesh reduced, the colour of the meat and fat rose, and the stability of the lipid in frozen meat increased (Zenteno-Savýn et al, 2002). In training Thoroughbred horses, Sato et al (2015) found that continuous dietary supplementation with astaxanthin and L-carnitine decreased serum Creatine kinase and Lactate dehydrogenase isoenzyme-5(LDH-5) activity levels and delayed the onset of clinical signs of exertional rhabdomyolysis. Inoue et al (2019) reported that in rooster sperm, astaxanthin and cadmium nanoparticles protected against lipid peroxidation and improved the enzymatic (MDA, CAT, SOD, TAC and GPX) antioxidant systems. ...
... Область применения L-карнитина в клинической практике достаточно широка: его используют при кардиомиопатии, недоедании, циррозе печени, диабете, эндокринных расстройствах, сепсисе, старении, нейропатических расстройствах [2,3]. Результаты ранее проведенных экспериментальных и эпидемиологических исследований использования L-карнитина в качестве терапевтического средства подтверждают целесообразность его применения в лечебной практике в ветеринарии [4][5][6][7]. Карнитин благотворно влияет на продуктивность животных, повышая устойчивость к заболеваниям обмена веществ, предотвращает ряд заболеваний, укрепляет иммунную системы и играет важную роль в метаболических и физиологических процессах [8][9][10][11][12][13][14][15][16]. ...
To date, there is no registered injectable dosage form of levocarnitine for veterinary use on the territory of the Russian Federation. Based on the above, the purpose of our work was to conduct preclinical studies of L-carnitine of subchronic toxicity for veterinary use in laboratory animals. Experiments to test the toxicity were performed on outbred rats in October 2021 at the vivarium of St. Petersburg State University of Veterinary Medicine. The study involved females weighing 190210 grams, purchased from RAPPOLOVO Laboratory Animal Nursery. To study subchronic toxicity via subcutaneous injection, L-carnitine was administered in 2 dose levels. The doses were determined based on the results of the acute toxicity experiment: 1/5 and 1/10 of the maximum tolerated dose. The first experimental group (n=10) received the drug subcutaneously at a dose of 0.08 mg/kg (1/5 of 2000 mg/kg). The second experimental group (n = 10) received the drug subcutaneously at a dose of 0.04 mg/kg (1/10 of 2000 mg/kg). The control group (n = 10) received sodium chloride 0.09 % subcutaneously at a dose of 1/5 of 2000 mg/kg. The drug was administered subcutaneously daily for 42 days. Killing and blood sampling from the second half of the animals was carried out after assessing the recovery period (10 days after drug cancellation). As a result of studies of subchronic toxicity of subcutaneously administered L-carnitine for veterinary use in laboratory animals, it was found that the dosage of 1/5 of the maximum tolerated, and the dosage of 1/10 of the maximum tolerated, do not cause external signs of toxicosis and death of rats. No significant changes in the hematological parameters of blood of animals from the experimental and control groups were found.
... Currently, to the best of our knowledge, there are no published clinical studies on astaxanthin supplementation in horses suffering from EMS. Nevertheless, studies by Sato et al. showed that supplementation of astaxanthin and L-carnitine during training of Thoroughbred horses reduced the incidence of exercise-induced muscle damage due to their mutual antioxidant properties [83]. Research on the use of natural extracts against EMS was conducted by Nawrocka et al. ...
Astaxanthin is gaining recognition as a natural bioactive component. This study aimed to test whether astaxanthin could protect adipose-derived stromal stem cells (ASCs) from apoptosis, mitochondrial dysfunction and oxidative stress. Phaffia rhodozyma was used to extract astaxanthin, whose biocompatibility was tested after 24, 48 and 72 h of incubation with the cells; no harmful impact was found. ASCs were treated with optimal concentrations of astaxanthin. Several parameters were examined: cell viability, apoptosis, reactive oxygen levels, mitochondrial dynamics and metabolism, superoxide dismutase activity, and astaxanthin’s antioxidant capacity. A RT PCR analysis was performed after each test. The astaxanthin treatment significantly reduced apoptosis by modifying the normalized caspase activity of pro-apoptotic pathways (p21, p53, and Bax). Furthermore, by regulating the expression of related master factors SOD1, SOD2, PARKIN, PINK 1, and MFN 1, astaxanthin alleviated the oxidative stress and mitochondrial dynamics failure caused by EMS. Astaxanthin restored mitochondrial oxidative phosphorylation by stimulating markers associated with the OXPHOS machinery: COX4I1, COX4I2, UQCRC2, NDUFA9, and TFAM. Our results suggest that astaxanthin has the potential to open new possibilities for potential bio-drugs to control and suppress oxidative stress, thereby improving the overall metabolic status of equine ASCs suffering from metabolic syndrome.
... 57 In one study, 75 mg/kg ASX was administered to horses for 8 weeks, and the results revealed that muscle damage decreased significantly due to the decrease in creatine kinase (CK) activity compared to the control group. 58 The preferred dose of ASX in studies generally ranges from 3 to 50 mg/kg. [59][60][61] No genotoxic or mutagenic effect of ASX given in doses of 40,200, and 1000 mg/kg/day, in addition to diet, has been reported. ...
This study evaluated the effects of astaxanthin (ASX) on alveolar bone loss, receptor activator of nuclear factor-κB ligand (RANKL), and osteoprotegerin (OPG) activity in ligature-induced periodontitis in diabetic rats. Diabetes mellitus (DM) was induced with 50 mg/kg intraperitoneal streptozotocin in 40 male Wistar rats. The Wistar rats were divided into six experimental groups: non-ligated (NL; n = 6); ligature only (L; n = 6); DM only (D; n = 6); DM + ligature (DP; n = 6); DM + ligature + 1 mg/kg/day ASX (ASX 1 group; n = 8); and DM + ligature + astaxanthin 5 mg/kg/day ASX (ASX 5 group; n = 8). Silk ligatures were placed along the gingival margin of the left mandibular first molar tooth. The study duration was 11 days, after which the animals were euthanised. Changes in alveolar bone levels were clinically measured, and RANKL and OPG activities were immunohistochemically examined. Alveolar bone loss was the most significant in the DP group (p < 0.05). Decreased alveolar bone loss was observed in the ASX 5 group (p < 0.05). Although RANKL activity was highest in the DP group, it was observed at lower levels in the groups to which ASX was administered. OPG activity did not differ between groups (p > 0.05). The results of this study suggested that 1 and 5 mg/kg ASX administration reduced RANKL activity and alveolar bone loss in rats with experimentally induced periodontitis.
... H. pluvialis-derived astaxanthin has been patented for improving mammalian muscle function and treatment of mammalian muscle disorders such as equine exertional rhabdomyolysis with 30 mg of astaxanthin supplementation daily resulting in symptom-free horses after only 2-3 weeks [117]. Daily administration of 75-mgday À1 astaxanthin through an inert carrier has been shown to be effective for minimizing exercise-induced muscle damage [118]. ...
The Haematococcus pluvialis–derived astaxanthin industry has been a commercial success for the nutraceutical market, but several constraints remain to be addressed including high downstream processing costs (primarily cell disruption and extraction) to dominate the aquaculture and animal feed markets. This chapter will evaluate the most effective harvesting, cell disruption, and extraction processes for astaxanthin. Limited studies have focused on the encapsulation of astaxanthin for the nutraceutical market, and this is discussed in detail. The incorporation of astaxanthin as a whole cell biomass for animal/aquaculture feed and as a functional food/fortifying agent for the human market is discussed. Overall the downstream processing developments in the coming years will lead to a more economically and environmentally viable biobased production process to expand the product range of astaxanthin beyond nutraceuticals and to replace the commercially available synthetic astaxanthin additive in aquaculture.
... Therefore, it can inhibit damage caused by cellular lipids and DNA peroxidation, and astaxanthin has a positive effect on relieving eye fatigue, anti-inflammatory, and protecting the central nervous system. In the field of sports science, astaxanthin has the effect of relieving skeletal muscle and myocardial damage, maintaining skeletal muscle tone and endurance, and delaying exercise fatigue [5][6][7]. In recent years, there has been some new research on astaxanthin in the field of sports. ...
... So, the availability of carnitine even in the baseline level can reduce the rate of loss of physical function and prevent muscle fatigue (Naclerio, Larumbe-Zabala, Cooper, Allgrove, & Earnest, 2015;Pandareesh & Anand, 2013;Sato et al., 2015). Eizadi et al. (2009) investigated the Influence of short-term L-carnitine and heparin 90 minutes before exercise. ...
Background. Probably L-Carnitine can induce the increase of Pyruvate dehydrogenase activity, decrease of
lactic acid production and performance improvements due to the reinforcement of long chain fatty acid oxidation
and stabilize of coASH to free COA. Based on this, the aim of our study was to investigate the effects of acute
L-Carnitine supplementation on blood lactate, glucose, VO 2 max and anaerobic power in elite male artistic gymnasts.
Methods. Eighteen male artistic gymnasts were randomly assigned to supplementation (n = 9) or placebo
(n = 9) groups. In a double blind design, subjects participated in two tests with a break of one week between them.
Subjects ingested 3 grams of L-Carnitine or placebo (maltodextrin) 90 minutes before aerobic and anaerobic exercise
protocols. We used a 20 m shuttle run as an aerobic exercise protocol and running based anaerobic sprint test (RAST)
as an anaerobic exercise protocol. Blood samples were collected 5 minutes pre and 4 minutes post-tests for the
analysis of lactate and glucose.
Results. L-Carnitine group had significantly lower lactate concentration than placebo group after tests (p < .05).
L-Carnitine group had significantly higher blood glucose (p < .05) compared with placebo group, too. Also VO 2 max
as well as mean and maximum power in L-Carnitine group were significantly higher than those in placebo group
(p < .05).
Conclusions. These findings indicated that acute oral supplementation of L-Carnitine can probably induce
fatigue decrease and improvement of aerobic and anaerobic performance in elite male artistic gymnasts.
Keywords: L-carnitine, lactate, glucose, aerobic exercise, anaerobic exercise, gymnastics.
... Therefore, to reduce the oxidative stress in the synovial fluid during arthritis, it is important to improve the antioxidant capacity. At early stages of arthritis, oxidative stress can be reduced by intra-articular administration of substances having antioxidant capacity, such as vitamin C, vitamin E, astaxanthin, and low molecular weight hyaluronic acid [11,19,23]. ...
Arthritis is thought to cause oxidative stress in synovial fluid in humans, but there have been few reports in horses. To evaluate oxidative stress in synovial fluid in horses, this study used 19 horses with unilateral fracture of the carpal joint bone. Synovial fluid was collected from the carpal joint on the fracture (arthritis group) and contralateral (control group) sides. Diacron-reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) were then measured, and the oxidative stress index (OSI) was calculated. d-ROMs and OSI of the arthritis group were significantly higher than the control group. BAP of the arthritis group was significantly lower than the control group. Thus, this study revealed that oxidative stress develops in the synovial fluid of horses during arthritis.
... Alguns ingredientes presentes nos suplementos comerciais, como a L-carnitina (Sato et al., 2015), aminoácidos de cadeia ramificada (BCAAs) (Harris e Harris, 2005), gama-orizanol (Ostaszewski et al., 2012), cromo quelato (Jordão et al., 2010), ômega 3, pré e próbiótico (Urschel e Lawrence, 2013) e creatina (Teixeira et al., 2016), podem auxiliar na diminuição de lesões musculares induzidas pelo exercício, no aumento de energia disponível e na redução da fadiga. Entre os suplementos comerciais, destaca-se o Tonnus JCR ® por possuir esses componentes na sua formulação, sendo desenvolvido para equinos com o intuito de melhorar o desempenho atlético, acelerar o processo de recuperação entre um exercício e outro, além de diminuir os riscos de lesão muscular (Vetnil, 2012). ...
O Team Penning (TP) é uma modalidade equestre que exige velocidade máxima. Nesse tipo de exercício ocorre o rápido consumo de energia pela via anaeróbica. Diversos suplementos têm sido desenvolvidos para melhorar o desempenho e diminuir lesões musculares em equinos atletas. Objetivou-se neste estudo avaliar a influência da suplementação com Tonnus JCR® nos parâmetros fisiológicos, metabolismo energético e muscular no treinamento de TP. Foram utilizados 12 equinos da raça Quarto de Milha, atletas de TP, separados em dois grupos, suplementado (GS) e não suplementado (GNS), avaliados em dois treinos. Foi realizado o exame físico, avaliação das concentrações plasmáticas de glicose e lactato, e concentrações séricas de creatinoquinase (CK), aspartato aminotransferase (AST) e lactato desidrogenase (LDH). As amostras de sangue foram colhidas durante e após os treinos em 12 diferentes momentos (M0 - M11). A suplementação foi realizada no intervalo entre os treinos. No segundo treino, verificou-se diminuição nas concentrações de glicose no GS quando comparado ao treino 1 (p = 0,01); no GNS não houve diferença entre os treinos (p = 0,13). Não houve diferença nas concentrações de lactato entre grupos e treinos. Os valores da concentração de CK no treino 1 não apresentaram diferença entre os grupos (p = 0,83) e momentos (p = 0,16). Quando comparadas as concentrações de CK entre os grupos no treino 2, observaram-se concentrações menores no GS (p = 0,02). Ao se comparar o GS antes e após a suplementação, as concentrações de CK foram menores no treino 2 (p = 0,01). No GNS não houve diferença entre os treinos (p = 0,51). As enzimas AST e LDH não diferiram entre os grupos nos treinos 1 e 2. Concluiu-se que a suplementação influenciou de forma positiva, diminuindo as concentrações de glicose e os níveis de CK, o que indica menor injúria muscular pós-treino.
The singlet oxygen quenching activities among common hydrophilic and lipophilic antioxidants such as
polyphenols, tocopherols, carotenoids, ascorbic acid, coenzyme Q10 and α-lipoic acid were recorded under the
same test condition: the chemiluminescence detection system for direct 1O2 counting using the
thermodissociable endoperoxides of 1,4-dimethylnaphthalene as 1O2 generator in DMF : CDCl3 (9 : 1).
Carotenoids exhibited larger total quenching rate constants than other antioxidants, with astaxanthin showing
the strongest activity. α-Tocopherol and α-lipoic acid showed considerable activities, whereas the activities of
ascorbic acid, CoQ10 and polyphenols were only slight; these included capsaicin, probucol, edaravon, BHT
and Trolox. This system has the potential of being a powerful tool to evaluate the quenching activity against
singlet oxygen for various hydrophilic and lipophilic compounds.
Astaxanthin, one of the dominant carotenoids in marine animals, showed both a strong quenching effect against singlet oxygen, and a strong scavenging effect against free radicals. These effects are considered to be defence mechanisms in the animals for attacking these active oxygen species. The activities of astaxanthin are approximately 10 times stronger than those of other carotenoids that were tested, namely zeaxanthin, lutein, tunaxanthin, canthaxanthin and β-carotene, and 100 times greater than those of a tocopherol. Astaxanthin also showed strong activity as an inhibitor of lipid peroxidation mediated by these active forms of oxygen. From these results, astaxanthin has the properties of a “SUPER VITAMIN E”.
The purpose of the current study was to examine the effect of Astaxanthin (Asx) supplementation on muscle enzymes as indirect markers of muscle damage, oxidative stress markers and antioxidant response in elite young soccer players.
Thirty-two male elite soccer players were randomly assigned in a double-blind fashion to Asx and placebo (P) group. After the 90 days of supplementation, the athletes performed a 2 hour acute exercise bout. Blood samples were obtained before and after 90 days of supplementation and after the exercise at the end of observational period for analysis of thiobarbituric acid-reacting substances (TBARS), advanced oxidation protein products (AOPP), superoxide anion (O2•¯), total antioxidative status (TAS), sulphydril groups (SH), superoxide-dismutase (SOD), serum creatine kinase (CK) and aspartate aminotransferase (AST).
TBARS and AOPP levels did not change throughout the study. Regular training significantly increased O2•¯ levels (main training effect, P<0.01). O2•¯ concentrations increased after the soccer exercise (main exercise effect, P<0.01), but these changes reached statistical significance only in the P group (exercise x supplementation effect, P<0.05). TAS levels decreased significantly post- exercise only in P group (P<0.01). Both Asx and P groups experienced increase in total SH groups content (by 21% and 9%, respectively) and supplementation effect was marginally significant (P=0.08). Basal SOD activity significantly decreased both in P and in Asx group by the end of the study (main training effect, P<0.01). All participants showed a significant decrease in basal CK and AST activities after 90 days (main training effect, P<0.01 and P<0.001, respectively). CK and AST activities in serum significantly increased as result of soccer exercise (main exercise effect, P<0.001 and P<0.01, respectively). Postexercise CK and AST levels were significantly lower in Asx group compared to P group (P<0.05)
The results of the present study suggest that soccer training and soccer exercise are associated with excessive production of free radicals and oxidative stress, which might diminish antioxidant system efficiency. Supplementation with Asx could prevent exercise induced free radical production and depletion of non-enzymatic antioxidant defense in young soccer players.
We report a two- to three-fold increase in free radical (R•) concentrations of muscle and liver following exercise to exhaustion. Exhaustive exercise also resulted in decreased mitochondrial respiratory control, loss of sarcoplasmic reticulum (SR) and endoplasmic reticulum (ER) integrity, and increased levels of lipid peroxidation products. Free radical concentrations, lipid peroxidation, and SR, ER, and mitochondrial damage were similar in exercise exhausted control animals and non-exercised vitamin E deficient animals, suggesting the possibility of a common R• dependent damage process. In agreement with previous work showing that exercise endurance capacity is largely determined by the functional mitochondrial content of muscle (1–4), vitamin E deficient animals endurance was 40% lower than that of controls. The results suggest that R• induced damage may provide a stimulus to the mitochondrial biogenesis which results from endurance training.
The effects of the carotenoids β-carotene and astaxanthin on the peroxidation of liposomes induced by ADP and Fe2+ were examined. Both compounds inhibited production of lipid peroxides, astaxanthin being about 2-fold more effective than β-carotene. The difference in the modes of destruction of the conjugated polyene chain between β-carotene and astaxanthin suggested that the conjugated polyene moiety and terminal ring moieties of the more potent astaxanthin trapped radicals in the membrane and both at the membrane surface and in the membrane, respectively, whereas only the conjugated polyene chain of β-carotene was responsible for radical trapping near the membrane surface and in the interior of the membrane. The efficient antioxidant activity of astaxanthin is suggested to be due to the unique structure of the terminal ring moiety.
We examined the effect of Astaxanthin (AST) on substrate metabolism and cycling time trial (TT) performance by randomly assigning 21 competitive cyclists to 28 d of encapsulated AST (4 mg/d) or placebo (PLA) supplementation. Testing included a VO2max test and on a separate day a 2 h constant intensity pre-exhaustion ride, after a 10 h fast, at 5% below VO2max stimulated onset of 4 mmol/L lactic acid followed 5 min later by a 20 km TT. Analysis included ANOVA and post-hoc testing. Data are Mean (SD) and (95% CI) when expressed as change (pre vs. post). Fourteen participants successfully completed the trial. Overall, we observed significant improvements in 20 km TT performance in the AST group (n=7; -121 s; 95% CI, -185, -53), but not the PLA (n=7; -19 s; 95% CI, -84, 45). The AST group was significantly different vs. PLA (P<0.05). The AST group significantly increased power output (20 W; 95% CI, 1, 38), while the PLA group did not (1.6 W; 95% CI, -17, 20). The mechanism of action for these improvements remains unclear, as we observed no treatment effects for carbohydrate and fat oxidation, or blood indices indicative of fuel mobilization. While AST significantly improved TT performance the mechanism of action explaining this effect remains obscure.
Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine animal carotenoids from natural product chemistry, metabolism, food chain, and chemosystematic viewpoints, and also describe new structural carotenoids isolated from marine animals over the last decade.
Non‐technical summary After 30 years of endeavour, this is the first study to show that muscle carnitine content can be increased in humans by dietary means and, perhaps more importantly, that carnitine plays a dual role in skeletal muscle fuel metabolism that is exercise intensity dependent. Specifically, we have shown that increasing muscle total carnitine content reduces muscle carbohydrate use during low intensity exercise, consistent with an increase in muscle lipid utilisation. However, during high intensity exercise muscle carnitine loading results in a better matching of glycolytic, pyruvate dehydrogenase complex and mitochondrial flux, thereby reducing muscle anaerobic energy generation. Collectively, these metabolic effects resulted in a reduced perception of effort and increased work output during a validated exercise performance test. These findings have significant implications for athletic performance and pathophysiological conditions where fat oxidation is impaired or anaerobic ATP production is increased during exercise.
The effect of vitamin E intake on indicators of muscle integrity was studied in exercised horses. Nineteen horses were blocked by sex and then assigned to one of three diets: no supplemental vitamin E (BASAL), BASAL plus 80 IU of supplemental vitamin E/kg DM (80), or BASAL plus 300 IU of supplemental vitamin E/kg DM (300). The BASAL diet contained less than 44 IU of vitamin E/kg DM, but it was adequate in all other nutrients. During the 90-d treatment period, horses were exercised 5 d/wk; in addition, serum and middle gluteal muscle alpha-tocopherol concentrations were measured at 0, 30, and 90 d. All horses performed a repeated submaximal exercise test (RSET) at the end of the 90-d period. The following were measured before and after the RSET: alpha-tocopherol, thiobarbituric acid reactive substances (TBARS), conjugated diene (CD) concentrations of the middle gluteal muscle, and serum creatine kinase (CK) and aspartate aminotransferase (AST) activities. Serum alpha-tocopherol concentrations of horses receiving the BASAL and 80 diets decreased (P < .05 and P < .06, respectively) during the 90-d treatment period but did not change in horses receiving the 300 diet. Serum and muscle alpha-tocopherol concentrations were higher (P < .05) at 30 and 90 d in horses receiving the 300 diet than in horses receiving the BASAL and 80 diets. Serum CK and AST activities increased (P < .05) following RSET but were not affected by dietary vitamin E level. Muscle alpha-tocopherol level did not affect muscle CD or TBARS.
L‐carnitine, a betaine derivative of β‐hydroxybutyrate, is found in virtually all cells of higher animals and also in some microorganisms and plants. In animals it is synthesized almost exclusively in the liver. Two essential amino acids, i.e., lysine and methionine serve as primary substrates for its biosynthesis. Also required for its synthesis are sufficient amounts of vitamin B6, nicotinic acids, vitamin C and folate. The first discovered ergogenic function of L‐carnitine is the transfer of activated long‐chain fatty acids across the inner mitochondrial membrane into the mitochondrial matrix. For this transfer acyl‐CoA esters are transesterified to form acylcarnitine esters. Thus, in carnitine deficiency fat oxidation and energy production from fatty acids are markedly impaired. Skeletal muscles constitute the main reservoir of carnitine in the body and have a carnitine concentration at least 200 times higher than blood plasma. Uptake of carnitine by skeletal muscles takes place by an active transport mechanism which transports L‐carnitine into muscles probably in the form of an exchange process with γ‐butyrobetain.
We examined the influence of L-carnitine L-tartrate (LCLT) on markers of purine catabolism, free radical formation, and muscle tissue disruption after squat exercise. With the use of a balanced, crossover design (1 wk washout), 10 resistance-trained men consumed a placebo or LCLT supplement (2 g L-carnitine/day) for 3 wk before obtaining blood samples on six consecutive days (D1 to D6). Blood was also sampled before and after a squat protocol (5 sets, 15-20 repetitions) on D2. Muscle tissue disruption at the midthigh was assessed using magnetic resonance imaging (MRI) before exercise and on D3 and D6. Exercise-induced increases in plasma markers of purine catabolism (hypoxanthine, xanthine oxidase, and serum uric acid) and circulating cytosolic proteins (myoglobin, fatty acid-binding protein, and creatine kinase) were significantly (P < or = 0.05) attenuated by LCLT. Exercise-induced increases in plasma malondialdehyde returned to resting values sooner during LCLT compared with placebo. The amount of muscle disruption from MRI scans during LCLT was 41-45% of the placebo area. These data indicate that LCLT supplementation is effective in assisting recovery from high-repetition squat exercise.
Dietary antioxidants may attenuate oxidative damage from strenuous exercise in various tissues. Beneficial effects of the antioxidant astaxanthin have been demonstrated in vitro, but not yet in vivo. We investigated the effect of dietary supplementation with astaxanthin on oxidative damage induced by strenuous exercise in mouse gastrocnemius and heart. C57BL/6 mice (7 weeks old) were divided into groups: rested control, intense exercise, and exercise with astaxanthin supplementation. After 3 weeks of exercise acclimation, both exercise groups ran on a treadmill at 28 m/min until exhaustion. Exercise-increased 4-hydroxy-2-nonenal-modified protein and 8-hydroxy-2'-deoxyguanosine in gastrocnemius and heart were blunted in the astaxanthin group. Increases in plasma creatine kinase activity, and in myeloperoxidase activity in gastrocnemius and heart, also were lessened by astaxanthin. Astaxanthin showed accumulation in gastrocnemius and heart from the 3 week supplementation. Astaxanthin can attenuate exercise-induced damage in mouse skeletal muscle and heart, including an associated neutrophil infiltration that induces further damage.
This study tested the development of oxidative stress and the effects of antioxidant supplementation in an 80-km ride. A precompetition survey revealed that no competitor would participate without vitamin E supplementation; therefore, 46 horses were paired for past performances and randomly assigned to two groups of 23 each for 3 wk of supplementation before the ride. One group (E) was orally supplemented with 5,000 IU of vitamin E per day; the other group (E+C) received that dose of vitamin E plus 7 g/d of vitamin C. Blood samples, temperature, and heart rate were taken the day before the race, at 21 and 56 km during the ride, at completion, and after 20 min of recovery. Plasma was assayed for lipid hydroperoxides, alpha-tocopherol, total ascorbate, albumin, creatine kinase (CK), and aspartate aminotransferase (AST). Total glutathione and glutathione peroxidase activity were determined in red blood cells and white blood cells. Thirty-four horses completed the race, 12 horses (six in E and six in E+C) did not finish for reasons including lameness, metabolic problems, and rider option. Plasma ascorbate was higher (P = 0.045) in the E+C group than in the E group. Other than ascorbate, neither antioxidant status nor CK and AST activities were affected by supplementation with E+C vs. E. Red blood cell glutathione peroxidase, white blood cell total glutathione, lipid hydroperoxides, CK, and AST increased, and red blood cell total glutathione and white blood cell glutathione peroxidase activity decreased with distance (P < 0.001). Positive correlations were found for plasma lipid hydroperoxides on CK (r = 0.25; P = 0.001) and AST (r = 0.33; P < 0.001). These results establish an association between muscle leakage and a cumulative index of oxidative stress.
The present study was designed to determine the effect of astaxanthin on endurance capacity in male mice aged 4 weeks. Mice were given orally either vehicle or astaxanthin (1.2, 6, or 30 mg/kg body weight) by stomach intubation for 5 weeks. The astaxanthin group showed a significant increase in swimming time to exhaustion as compared to the control group. Blood lactate concentration in the astaxanthin groups was significantly lower than in the control group. In the control group, plasma non-esterfied fatty acid (NEFA) and plasma glucose were decreased by swimming exercise, but in the astaxanthin group, NEFA and plasma glucose were significantly higher than in the control group. Astaxanthin treatment also significantly decreased fat accumulation. These results suggest that improvement in swimming endurance by the administration of astaxanthin is caused by an increase in utilization of fatty acids as an energy source.
The rate constants (ks of 1O2 scavenging for α-tocopherol (α-Toc) and β-carotene (β-Car) were measured in liposome membranes, and compared with those in EtOH solution. 1O2 was site-specifically generated by photoirradiation using two photosensitizers, water-soluble Rose bengal (RB) and lipid-soluble 12-(1-pyrene)-dodecanoic acid (PDA). The ks value for β-Car in EtOH solution was 1.3 × 1010 M−1 s−1, which was 36 times that for α-Toc (3.6 × 108 M−1 s−1), but there was no difference between their ks values in liposomes (1.8 × 107 M−1 s−1 for β-Car and 1.2 × 107 M−1 s−1 for α-Toc). In the liposomes, the ks value for α-Toc was affected by the membrane site where 1O2 was generated, which depended on the localization of the photosensitizer, being high at the membrane surface in the RB-system and low in the inner region of the membrane in the PDA-system. In contrast, the ks value for β-Car was not affected by the 1O2-generating site. These differences were supposed to be caused by differences in the relative concentrations of 1O2 and active sites of α-Toc and β-Car in the membranes. α-Toc and β-Car inhibited 1O2-dependent peroxidation of egg yolk phosphatidylcholine (egg PC). The concentrations of α-Toc required for 50% inhibition of lipid peroxidation (IC50) were higher than those of β-Car, being more than 6 times higher in EtOH solution and less than 2 times higher in liposomes. The ratio of the antioxidant activity of β-Car to that of α-Toc was more in EtOH solution than in liposomes, and was well correlated with the ratio of their 1O2 scavenging rate constants.
When oxygenic photosynthesis evolved, one of the key functions of carotenoids was to protect aerobic photosynthetic organisms against destruction by photodynamic sensitization. Aerobic photosynthesis would not exist without the coevolution of carotenoids alongside the chlorophylls. As carotenoids are abundant in nature, in many fruits and vegetables, they are able to react with excited states of appropriate energy and quench them, and they can react with free radicals according to their reactivity, redox potentials, and XÐH bond energies. This report concerns the bimolecular reactions of carotenoids with oxygen species, such as 3 O 2 , 1 O 2 , H , HO , À 2 , etc.
Two human clinical studies were performed. One was an open-label non-controlled study involving 30 healthy female subjects for 8 weeks. Significant improvements were observed by combining 6 mg per day oral supplementation and 2 ml (78.9 μM solution) per day topical application of astaxanthin. Astaxanthin derived from the microalgae, Haematococcus pluvialis showed improvements in skin wrinkle (crow's feet at week-8), age spot size (cheek at week-8), elasticity (crow's feet at week-8), skin texture (cheek at week-4), moisture content of corneocyte layer (cheek in 10 dry skin subjects at week-8) and corneocyte condition (cheek at week-8). It may suggest that astaxanthin derived from H. pluvialis can improve skin condition in all layers such as corneocyte layer, epidermis, basal layer and dermis by combining oral supplementation and topical treatment. Another was a randomized double-blind placebo controlled study involving 36 healthy male subjects for 6 weeks. Crow's feet wrinkle and elasticity; and transepidermal water loss (TEWL) were improved after 6 mg of astaxanthin (the same as former study) daily supplementation. Moisture content and sebum oil level at the cheek zone showed strong tendencies for improvement. These results suggest that astaxanthin derived from Haematococcus pluvialis may improve the skin condition in not only in women but also in men.
Cardiovascular risks are frequently accompanied by high serum fatty acid levels. Although recent studies have shown that fatty acids affect mitochondrial function and induce cell apoptosis, L-carnitine is essential for the uptake of fatty acids by mitochondria, and may attenuate the mitochondrial dysfunction and apoptosis of cardiocytes. This study aimed to elucidate the activity of L-carnitine in the prevention on fatty acid-induced mitochondrial membrane permeability transition and cytochrome c release using isolated cardiac mitochondria from rats. Palmitoyl-CoA-induced mitochondrial respiration that was observed with L-carnitine was inhibited with oligomycin. The palmitoyl-CoA-induced mitochondrial membrane depolarization and swelling were greatly inhibited by the presence of L-carnitine. In ultrastructural observations, terminally swollen and ruptured mitochondria with little or no distinguishable cristae structures were induced by treatment with palmitoyl-CoA. However, the severe morphological damage in cardiac mitochondria was dramatically inhibited by pretreatment with L-carnitine. Treatment with L-carnitine also attenuated 4-hydroxy-L-phenylglycine- and rotenone-induced mitochondrial swelling even when the L-carnitine could not protect against the decrease in oxygen consumption associated with these inhibitors. Furthermore, L-carnitine completely inhibited palmitoyl-CoA-induced cytochrome c release. We concluded that L-carnitine is essential for cardiac mitochondria to attenuate the membrane permeability transition, and to maintain the ultrastructure and membrane stabilization, in the presence of high fatty acid β-oxidation. Consequently, the cells may be protected against apoptosis by L-carnitine through inhibition of the fatty acid-induced cytochrome c release.
Reasons for performing study:
Intense physical exercise produces an excess of reactive oxygen species which can disturb the antioxidant/oxidant balance of the horse in training. Several classes of antioxidant dietary compounds have been suggested to provide health benefits and there is evidence that consumption of these products leads to a reduction in the expression of various pro-inflammatory and/or oxidative stress biomarkers. The recent development of a new galenic system allows the oral delivery of the antioxidant enzyme: superoxide dismutase (SOD). This has been developed from a specific melon variety with a particularly high SOD activity.
Objectives:
To study the influence of an oral supplementation with an encapsulated melon rich in SOD on muscular and antioxidant balance variables in a population of Standardbreds in training.
Methods:
Twenty-four Standardbreds in training were paired by age, sex and training level. They were randomly split into 2 groups: SOD group (520 iu/day) and placebo group. At the beginning of the study (T0) and after 30 days (T30) and 60 days (T60) of supplementation, physiological response during a standardised exercise test, plasma muscular enzymes at rest and post exercise (creatine kinase), oxidative stress markers (erythrocyte SOD) and blood resistance to haemolysis (KRL test) were assessed. Analysis of variance of time, treatment and interaction time x treatment was calculated.
Results:
Between T0 and T60, in contrast with placebo group, a significant increase in the plasma resistance to haemolysis in the SOD group was observed and it was significantly higher (P < 0.05) in the SOD group than in the placebo group on T60. Between T0 and T60, resting CK remained constant in SOD group whereas a significant increase in plasma CK in the placebo group was observed. On T60, the CK level was significantly lower (P < 0.05) in SOD group than in the placebo group.
Conclusions:
These results suggest that oral SOD supplementation might increase blood resistance to haemolysis and reduce the increase in muscular membrane permeability induced by training.
Tying-up syndrome, also known as recurrent exertional rhabdomyolysis in Thoroughbreds, is a common muscle disorder for racehorses. In this study, we performed a multipoint linkage analysis using LOKI based on the Bayesian Markov chain Monte Carlo method using 5 half-sib families (51 affected and 277 nonaffected horses in total), and a genome-wide association study (GWAS) using microsatellites (144 affected and 144 nonaffected horses) to map candidate regions for tying-up syndrome in Japanese Thoroughbreds. The linkage analysis identified one strong L-score (82.45) between the loci UCDEQ411 and COR058 (24.9-27.9 Mb) on ECA12. The GWAS identified two suggestive genomic regions on ECA12 (24.9-27.8 Mb) and ECA20 (29.3-33.5 Mb). Based on both results, the genomic region between UCDEQ411 and TKY499 (24.9-27.8 Mb) on ECA12 was the most significant and was considered as a candidate region for tying-up syndrome in Japanese Thoroughbreds.
A total of 30 horses were divided into two groups, one served as a control whereas other was rhabdomyolysis diseased horses. After blood collection, the resulted sera were used for estimation of the activities of creatin kinase (CK), aspartate transaminase (AST), lactate dehydrogenase (LDH), lactic acid, triacylglycerol (TAG), glucose, total protein, albumin, globulin, urea, creatinine, Triiodothyronine (T(3)), calcium, sodium, potassium, phosphorus, chloride, vitamin E, interleukin-6 (IL-6) and tumor necrosis-α (TNF-α). In addition, whole blood was used for determination of selenium, reduced glutathione (G-SH) and prostaglandin F2-α (PGF2α). The erythrocyte hemolysates were used for the determination of the activities of super oxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), nitric oxide (NO) and malondialdehyde (MDA). The present findings revealed a significant (p ≤ 0.05) increase in the values of CK, AST, LDH, glucose, lactate, TAG, urea, creatinine, phosphorus, MDA, TNF- α, IL6 and PGF2- α in diseased horses when compared with the control. Furthermore, the values of calcium, SOD, CAT, TAC, NO and GSH in diseased horses were significantly (p ≤ 0.05) lower than the control. The other examined parameters were not statistically significant. In conclusion, the examined pro-inflammatory cytokines were useful biomarkers for the diagnosis of Equine rhabdomyolysis (ER) in Arabian horses beside the old examined biomarkers. In the future, efforts should be made to confirm this in other breed. If this could be achieved, it would open up new perspectives in research fields dealing with ER.
Chronic exertional rhabdomyolysis represents a syndrome of recurrent exercise-associated muscle damage in horses that arises from a variety of etiologies. Major advances have been made in the understanding of the pathophysiology of this disease, and causative genetic defects have been recently identified for two conditions-polysaccharide storage myopathy of quarter horses, paints, warm bloods, and draft breeds. Dietary management in combination with a regular exercise regimen comprises the most effective means for control of clinical signs.
Effects of astaxanthin (AX) derived from H. pluvialis on human blood rheology were investigated in 20 adult men with a single-blind method. The experimental group was 57.5 +/- 9.8 years of age and the placebo group was 50.8 +/- 13.1 years of age. A blood rheology test that measures whole blood transit time was conducted using heparinized blood of the volunteers by a MC-FAN apparatus (microchannel array flow analyzer). After administration of AX 6 mg/day for 10 days, the values of the experimental group were decreased from 52.8 +/- 4.9 s to 47.6 +/- 4.2 s (p<0.01) and a comparison of the values between the experimental (47.6 +/- 4.2 s) and the placebo (54.2 +/- 6.7 s) groups showed a significant difference (p<0.05). There were no adverse effects resulting from the administration of AX 6 mg/day for 10 days. Informed consent was obtained from each subject.
Lactic dehydrogenase, although widely distributed in most tissues, was more highly concentrated in skeletal muscle, cardiac muscle, kidney and liver. Isoenzyme patterns showed a selective concentration of LDH5 in skeletal muscle while in the heart LDH 1 and 2 were predominant. In contrast, creatine kinase was only present in substantial concentration in skeletal and cardiac muscle. The serum concentration of both enzymes showed a wide range of activity.
La deshydrogénase lactique, bien que largement pRÉSente dans la plupart des tissus, fut trouvée en plus forte concentration dans les muscles striés, dans le muscle cardiaque, dans le rein et dans le foie.
En revanche, pour la créatine kinase, les concentrations significatives furent celles du muscle cardiaque et des muscles striés. La concentration sérique des deux enzymes montra une grande variation.
Oblgeich die Laktatdehydrogenase ubiquitär in den meisten Geweben vorkommt, wird sie besonders konzentriert im Skelettmuskel, im Myokard, in der Niere und der Leber gefunden. Die Isoenzymmuster zeigten eine selektive Konzentration von LDH5 im Skelettmuskel, während im Myokard LDH1 und 2 prädominierten. Im Gegensatz dazu fand sich die Kreatinkinase in erheblicher Konzentration nur im Skelett- und Herzmuskel. Die Serum- konzentrationen beider Enzyme variierten in einem weiten Bereich.
The paper provides some basic epidemiological and clinical descriptive information for the equine rhabdomyolysis syndrome (ERS) in the United Kingdom. Information was obtained retrospectively from laboratory submission data as well as cases investigated by the author via their veterinary surgeon. Sex appeared to be a significant variable, with females being more likely than males to suffer from ERS compared to other conditions (P less than 0.01). More samples were submitted in the period November-February than at other times of the year (P less than 0.01). The condition appeared to be found in many breeds/types. Most episodes occurred whilst animals were being worked, although 38% occurred after exercise. In the majority of instances the affected animal was still able to walk. A clinical description of a very mild, mild, moderately severe and severe case of ERS is given. Utilizing all the information the syndrome was divided into five grades according to the severity of the stiffness and the presence or absence of auxiliary signs such as sweating and discoloured urine.
Mice were subjected to one session of strenuous running exercise and their soleus muscles were examined in respect of changes in ultrastructure and to their concentration of reduced glutathione [GSH] which are indicators of oxidative stress. It was hypothesized that invading leucocytes contributed to oxidative stress and they were functionally inhibited in one experimental group by the administration of colchicine. Exercise led to an immediate decrease in [GSH] of about 60%, which slowly recovered during 96 h after exercise. With the administration of colchicine after exercise, [GSH] was higher than in the untreated exercise group 48 h after exercise, indicating an inhibition of the ability of leucocytes to produce oxidative stress. However, at 96 h after exercise, [GSH] was lower in the treated exercise group than in the untreated group. The morphological evaluation of the percentage of affected fibres showed that the invasion of leucocytes increased muscle fibre damage. The results suggested that invading leucocytes enhanced production of reactive species of oxygen that may have participated in inducing muscle damage. However, inhibition of leucocyte invasion did not permit their scavenger action of removing cell debris, which appeared to produce even more oxidative stress in the muscle.
Carnitine is critical for normal skeletal muscle bioenergetics. Carnitine has a dual role as it is required for long-chain fatty acid oxidation, and also shuttles accumulated acyl groups out of the mitochondria. Muscle requires optimization of both of these metabolic processes during peak exercise performance. Theoretically, carnitine availability may become limiting for either fatty acid oxidation or the removal of acyl-CoAs during exercise. Despite the theoretical basis for carnitine supplementation in otherwise healthy persons to improve exercise performance, clinical data have not demonstrated consistent benefits of carnitine administration. Additionally, most of the anticipated metabolic effects of carnitine supplementation have not been observed in healthy persons. The failure to demonstrate clinical efficacy of carnitine may reflect the complex pharmacokinetics and pharmacodynamics of carnitine supplementation, the challenges of clinical trial design for performance endpoints, or the adequacy of endogenous carnitine content to meet even extreme metabolic demands in the healthy state. In patients with end stage renal disease there is evidence of impaired cellular metabolism, the accumulation of metabolic intermediates and increased carnitine demands to support acylcarnitine production. Years of nutritional changes and dialysis therapy may also lower skeletal muscle carnitine content in these patients. Preliminary data have demonstrated beneficial effects of carnitine supplementation to improve muscle function and exercise capacity in these patients. Peripheral arterial disease (PAD) is also associated with altered muscle metabolic function and endogenous acylcarnitine accumulation. Therapy with either carnitine or propionylcarnitine has been shown to increase claudication-limited exercise capacity in patients with PAD. Further clinical research is needed to define the optimal use of carnitine and acylcarnitines as therapeutic modalities to improve exercise performance in disease states, and any potential benefit in healthy individuals.
Polysaccharide storage myopathy (PSSM) is a distinct cause of exertional rhabdomyolysis in Quarter Horses that results in glycogen and abnormal polysaccharide accumulation. The purpose of this study was to determine if excessive glycogen storage in PSSM is due to a glycolytic defect that impairs utilisation of this substrate during exercise. Muscle biopsies, blood lactates and serum CK were obtained 1) at rest from 5 PSSM Quarter Horses, 4 normal Quarter Horses (QH controls) and 6 Thoroughbreds with recurrent exertional rhabdomyolysis (TB RER) and 2) after a maximal treadmill exercise test in PSSM and QH controls. In addition, 3 PSSM horses performed a submaximal exercise test. At rest, muscle glycogen concentrations were 2.4x and 1.9x higher in PSSM vs. QH controls or TB RER, respectively. Muscle lactates at rest were similar between PSSM and QH controls but significantly higher in PSSM vs. TB RER. Muscle glucose-6-phosphate concentrations were also higher in PSSM horses than controls combined. During maximal exercise, mean muscle glycogen concentrations declined 2.7x more and mean lactate increased 2x more in PSSM vs. QH controls; however, differences were not statistically significant. Blood lactate concentrations after maximal exercise did not reflect generally higher muscle lactate in PSSM vs. QH controls. No change in blood lactate concentrations occurred in PSSM horses with submaximal exercise. Serum CK activity increased significantly 4 h after maximal and submaximal exercise and was significantly higher in PSSM vs. QH controls. These results show that during maximal exercise, PSSM horses utilised muscle glycogen and produce lactic acid via a functional glycolytic pathway and that during submaximal exercise oxidative metabolism was unimpaired. The excessive glycogen storage and formation of abnormal polysaccharide in PSSM horses therefore appear to reflect increased glycogen synthesis rather than decreased utilisation. The specific subset of horses with exertional rhabdomyolysis due to PSSM would likely benefit clinically from a diet low in soluble carbohydrates like grain with fat added as well as gradually increasing daily exercise to reduce excessive glycogen accumulation and enhance utilisation.
Physical exercise increases both tissue needs for oxygen and cellular respiration and causes an overproduction of free radicals. When free radical generation exceeds the cell's antioxidant capacity tissue-damage develops due to oxidative stress. Therefore, it appears important to increase the scavenger ability of the tissues. Controlled training and dietary supplements may provide ways of doing this. As a model, we used 3-year-old racehorses (Equus caballus) which underwent a series of different physical exercise trials before and after 70 days of daily training and dietary supplements (vitamin E and selenium). The above treatments were able to increase both red blood cell resistance to the peroxidative stress induced in vitro and the glutathione peroxidase activity in lymphocytes. Moreover, they were also able to decrease malondialdehyde (MDA) concentration in the plasma as well as vitamin E consumption and the mobilisation of low molecular weight antioxidants (total peroxyl-radical trapping) following the physical exercise trials. The results obtained indicated that the training and diet supplements we used were able to significantly increase horse antioxidant defences in both the extracellular fluids and blood cells of our horses, thus decreasing peroxidative phenomena following physical exercise.
To determine incidence, effect on performance, and management practices associated with exertional rhabdomyolysis (ER) in Thoroughbreds.
Medical records for 984 Thoroughbreds and a survey of trainers of horses with and without ER.
Medical records for 984 Thoroughbreds stabled at a midwestern racetrack were examined to determine the incidence of ER during the 1995 racing season. A retrospective questionnaire was administered to trainers to determine management practices associated with ER in 59 Thoroughbreds with ER and 47 control Thoroughbreds in training. Multiple logistic regression was used to determine management factors associated with ER.
ER affected 48 of 984 (4.9%) Thoroughbreds. Two-year-old females were most frequently affected, and 36 of 96 (37.5%) trainers had > or = 1 horse with ER. Horses with ER were more likely not to race during the racing season, compared with control horses. For horses that raced, differences were not found with respect to racing performance between ER and control horses. Exertional rhabdomyolysis developed frequently in susceptible horses that had > or = 1 day of rest prior to exercise and that galloped during exercise. Horses with ER were commonly fed > 4.5 kg of grain daily. Nervous and extremely nervous horses were 5.4 times more likely, and horses with some form of lameness were 4.2 times more likely, to have ER.
Exertional rhabdomyolysis is common in Thoroughbreds, and ER can be affected by temperament, sex, age, diet, exercise routines, and lameness. Management that minimizes excitability, particularly when tailored to each horse, may be most effective for controlling ER.
Carnitine is an endogenous compound with well-established roles in intermediary metabolism. An obligate for optimal mitochondrial fatty acid oxidation, it is a critical source of energy and also protects the cell from acyl-CoA accretion through the generation of acylcarnitines. Carnitine homeostasis is affected by exercise in a well-defined manner because of the interaction of the carnitine-acylcarnitine pool with key metabolic pathways. Carnitine supplementation has been hypothesized to improve exercise performance in healthy humans through various mechanisms, including enhanced muscle fatty acid oxidation, altered glucose homeostasis, enhanced acylcarnitine production, modification of training responses, and altered muscle fatigue resistance. Available experimental clinical studies designed to assess the effect of carnitine on exercise metabolism or performance in healthy humans do not permit definitive conclusions to be drawn. In the aggregate, however, these studies suggest that carnitine supplementation does not improve maximal oxygen uptake or metabolic status during exercise in healthy humans. Carnitine administration for </=1 mo in humans increases plasma carnitine concentrations but does not increase muscle carnitine content. Additional clinical trials integrating physiologic, biochemical, and pharmacologic assessments are needed to definitively clarify any effects of carnitine on exercise performance in healthy persons.
During exercise, the oxygen consumption and the production of free radicals increase and can lead to oxidative stress with a deleterious effect on cellular structures involved in physical activity. To evaluate the oxidative stress produced by exercise and the role of ascorbate as an antioxidant, venous blood samples were obtained from 44 thoroughbred racehorses, before and after a 1000+/-200-m race at maximum velocity. Fourteen of these horses were treated intravenously with 5 g of ascorbate before running. Antioxidant capacity (PAOC), endogenous and exogenous ascorbate concentration, total antioxidant reactivity (TAR), urate concentration, creatine kinase activity, protein concentration and thiobarbiturate reactive substances (TBAR) as oxidative stress indicators were measured in the plasma of some of these horses. PAOC, TAR and TBAR increased after the race, while plasma ascorbate and urate concentrations remained unchanged. Total plasma protein (TPP) concentrations increased in line with antioxidant capacity. As predicted, both the plasma ascorbate concentration and PAOC increased immediately after ascorbate administration, but was not modified after the race, such as TBAR. However, in both groups plasma creatine kinase activity increased after the race. These results would suggest that the administration of ascorbate could nullify the oxidative stress produced by exercise in thoroughbred racehorses, but could not prevent muscular damage.
Telephone surveys of 34 racing yards with 1276 horses in training were made to establish the overall incidence of exertional rhabdomyolysis in the previous year. A case-control study was used to investigate the risk factors for the syndrome in 12 yards selected on the basis of the routine confirmation of diagnoses by the evaluation of the serum activities of creatine kinase and aspartate aminotransferase. The overall incidence of the syndrome was 6.7 per cent and 80 per cent of the trainers had at least one affected horse. In 74 per cent of the affected horses it frequently recurred, with an average of six lost training days per episode. Risk factors identified for the syndrome included being female, having a nervous, excitable temperament, and being two years old.
We investigated the effect of L-carnitine supplementation on carnitine content in muscle fiber, glucose, and fatty acid metabolism and on performance in trained rats.
Male Wistar rats received a daily dose of 28 mg/kg, intragastrically, during the last 4 wk of a 6-wk moderate-intensity training program. The contents of carnitine and coenzyme A were evaluated in muscle fiber and its capacity to metabolize labeled glucose, oleate, and pyruvate. The ergogenic effect of the amine was assessed by the evaluation of time until exhaustion in an exercise session. The results were analyzed by analysis of variance and Tukey's post hoc test, and significance was set at P < 0.05.
In our model, carnitine supplementation increased time until exhaustion (14.0%), similar to that observed for trained rats, but the effect was even greater (30.3% increase) in the supplemented and trained rats. Carnitine supplementation increased oleate decarboxylation (17% for sedentary rats and 119% for trained rats) and decreased glucose (29.7% and 45% for sedentary and trained rats, respectively) and [2-(14)C ]-pyruvate (45.9% and 61% for sedentary and trained rats, respectively) decarboxylation. The flux of [1-(14)C]-pyruvate through the Krebs cycle increased by 32% and 70% for supplemented sedentary and trained rats, respectively. The training protocol also increased [1-(14)C]-pyruvate decarboxylation by 32%. The cytosolic content of free, long-chain, and short-chain acyl-carnitine increased in the soleus muscle obtained from supplemented sedentary rats by 28%, 117%, and 16%, respectively, and 99%, 205%, and 32% for the muscle from supplemented trained rats.
This study showed that carnitine supplementation increases fatty acid oxidation in skeletal muscle by a mechanism that includes increasing total carnitine content in soleus muscle mitochondria and the total content of acyl-carnitine. The most interesting finding was that the effect of supplementation was even greater in trained rats that had received 3-wk supplementation of carnitine.
To determine the effect of dietary starch, bicarbonate, and fat content on metabolic responses and serum creatine kinase (CK) activity in exercising Thoroughbreds with recurrent exertional rhabdomyolysis (RER), 5 RER horses were fed 3 isocaloric diets (28.8 Mcal/d [120.5 MJ/d]) for 3 weeks in a crossover design and exercised for 30 minutes on a treadmill 5 days/wk. On the last day of each diet, an incremental standardized exercise test (SET) was performed. The starch diet contained 40% digestible energy (DE) as starch and 5% as fat: the bicarbonate-starch diet was identical but was supplemented with sodium bicarbonate (4.2% of the pellet): and the fat diet provided 7% DE as starch and 20% as fat. Serum CK activity before the SET was similar among the diets. Serum CK activity (log transformed) after submaximal exercise differed dramatically among the diets and was greatest on the bicarbonate-starch diet (6.51 +/- 1.5) and lowest on the fat diet (5.71 +/- 0.6). Appreciable differences were observed in the severity of RER among individual horses. Postexercise plasma pH, bicarbonate concentration, and lactate concentration did not differ among the diets. Resting heart rates before the SET were markedly lower on the fat diet than on the starch diet. Muscle lactate and glycogen concentrations before and after the SET did not differ markedly among the diets. A high-fat, low-starch diet results in dramatically lower postexercise CK activity in severely affected RER horses than does a low-fat, high-starch diet without measurably altering muscle lactate and glycogen concentrations. Dietary bicarbonate supplementation at the concentration administered in this study did not prevent increased serum CK activity on a high-starch diet.
The purpose of this study was to determine whether oral L-carnitine supplementation enhances the responses of skeletal muscle to training in seven 2-year-old Standardbreds. Four horses were supplemented with 10 g/day L-carnitine for 10 weeks and 3 horses served as controls. All horses were exercised regularly every second day on a treadmill for 5 weeks (training period) and housed in individual boxes for 5 additional weeks (detraining period). The training period consisted of 8 high- and 8 low-speed exercises carried out in alternating sequence. Gluteus medius muscle biopsies were taken at Weeks 0 (pretraining), 5 (post-training) and 10 (detraining). Muscular adaptations to training were observed mainly in the L-carnitine-supplemented horses and included an increase in the percentage of type IIA fibres (delta35%, P<0.05), atrophy of type I fibres (delta24%, P<0.01), a rise in the capillary-to-fibre ratio (delta40%, P<0.01) and an increase in the quantitative reaction of periodic acid Schiff stain (delta11%, P<0.05), used as an indicator of intrafibre glycogen content. After detraining, most of these adaptations reverted towards the pretraining situation. Therefore, exogenous carnitine has an additive effect on muscular responses to training and this should be favourable to improve athletic performance. Nevertheless, further studies are necessary to show whether muscle carnitine content is a limiting factor for fatty acid oxidation.
Reactive oxygen species (ROS) produced during exercise may be involved in delayed-onset muscle damage related to inflammation. To investigate this hypothesis, we studied whether oxidative stress increases nuclear translocation of nuclear factor-kappaB and chemokine expression in skeletal muscle using myotube L6 cells. We also assessed whether prolonged acute exercise could increase these parameters in rats. In L6 cells, H(2)O(2) induced nuclear translocation of p65 and increased the expression of cytokine-induced neutrophil chemoattractant-1 (CINC-1) and monocyte chemoattractant protein-1 (MCP-1), whereas preincubation with alpha-tocopherol limited the increase in these proteins. Sprague Dawley rats were divided into the following groups: rested control, exercised, rested with a high alpha-tocopherol diet, and exercised with a high alpha-tocopherol diet. After 3 weeks of acclimation, both exercise groups ran on a treadmill at 25 m/min for 60 min. Exercise increased nuclear p65, CINC-1, and MCP-1 in gastrocnemius muscle cells, but these changes were ameliorated by the high alpha-tocopherol diet. Increases in myeloperoxidase and thiobarbituric acid-reactive substrates were ameliorated by a high alpha-tocopherol diet, as were the histological changes. Neutrophil activity was not altered by either exercise or a high alpha-tocopherol diet. These results indicate that delayed-onset muscle damage induced by prolonged exercise is partly related to inflammation via phagocyte infiltration caused by ROS and that alpha-tocopherol (an antioxidant) can attenuate such inflammatory changes.
Recent work on the initial switches that trigger cell death has revealed surprising inventions of nature that ensure the ordered suicide of a cell that has been selected for demise. Particularly intriguing is how a signal--the release of cytochrome c from the mitochondria--is translated into the activation of the death cascade, which leads to a point of no return. Now there is new understanding of how this crucial process is delicately handled by a cytosolic signalling platform known as the apoptosome. The formation of the apoptosome and the activation of its effector, caspase-9, reveals a sophisticated mechanism that might be more common than was initially thought.
Intracellular redox balance may affect nutrient metabolism in skeletal muscle. Astaxanthin, a carotenoid contained in various natural foods, exerts high antioxidative capacity in the skeletal muscles. The present study investigated the effect of astaxanthin on muscle lipid metabolism in exercise. ICR mice (8 weeks old) were divided into four different groups: sedentary, sedentary treated with astaxanthin, running exercise, and exercise treated with astaxanthin. After 4 weeks of treatment, exercise groups performed treadmill running. Astaxanthin increased fat utilization during exercise compared with mice on a normal diet with prolongation of the running time to exhaustion. Colocalization of fatty acid translocase with carnitine palmitoyltransferase I (CPT I) in skeletal muscle was increased by astaxanthin. We also found that hexanoyl-lysine modification of CPT I was increased by exercise, while astaxanthin prevented this increase. In additional experiment, we found that astaxanthin treatment accelerated the decrease of body fat accumulation with exercise training. Our results suggested that astaxanthin promoted lipid metabolism rather than glucose utilization during exercise via CPT I activation, which led to improvement of endurance and efficient reduction of adipose tissue with training.
Previous research has shown that L-carnitine L-tartrate (LCLT) supplementation beneficially affects markers of hypoxic stress following resistance exercise. However, the mechanism of this response is unclear. Therefore, the primary purpose of this study was to determine the effects of LCLT supplementation on muscle tissue oxygenation during and after multiple sets of squat exercise. Nine healthy, previously resistance-trained men (25.2 +/- 6.years, 91.2 +/- 10.2 kg, 180.2 +/- 6.3 cm) ingested 2 g.d of LCLT or an identical placebo for 23 days in a randomized, balanced, crossover, double-blind, placebo-controlled, repeated-measures study design. On day 21, forearm muscle oxygenation was measured during and after an upper arm occlusion protocol using near infrared spectroscopy (NIRS), which measures the balance of oxygen delivery in relation to oxygen consumption. On day 22, subjects performed 5 sets of 15 to 20 repetitions of squat exercise with corresponding measures of thigh muscle oxygenation, via NIRS, and serial blood draws. Compared to the placebo trial, muscle oxygenation was reduced in the LCLT trial during upper arm occlusion and following each set of resistance exercise. Despite reduced oxygenation, plasma malondealdehyde, a marker of membrane damage, was attenuated during the LCLT trial. There were no differences between trials in the vasoactive substance prostacyclin. In conclusion, because oxygen delivery was occluded during the forearm protocol, it is proposed that enhanced oxygen consumption mediated the reduced muscle oxygenation during the LCLT trial. Enhanced oxygen consumption would explain why hypoxic stress was attenuated with LCLT supplementation.
Astaxanthin, a natural nutritional component, is marketed as a dietary supplement around the world. The primary commercial source for astaxanthin is Haematococcus pluvialis (microalgae). The objective of the present study was to investigate the acute and subchronic toxicity of an astaxanthin-rich biomass of H. pluvialis (AstaCarox). The oral LD(50) of the biomass in rats was greater than 12g/kg body weight. In the subchronic study, Wistar rats (10/sex/group) were fed diets containing 0%, 1%, 5% and 20% of the biomass (weight/weight) for 90 days. trans-Astaxanthin was quantifiable in the plasma of the high-dose treated group only. Compared to the control group, no treatment-related biologically significant effects of astaxanthin were noted on body weight or body weight gain. Biomass feeding did not affect hematological parameters. In the high-dose group, slightly elevated alkaline phosphatase and changes in some urine parameters and an increase in kidney weight in both sexes were noted. Histopathology examinations did not reveal adverse effects except for a marginal increase in pigment in the straight proximal tubule of the kidney in 5/10 female rats treated with the high-dose. These changes were not considered as toxicologically significant. Although the rats in high-dose group received about 9% more fat, it is unlikely that this confounding factor significantly altered the outcome. The no-observed adverse-effect-levels (NOAEL) of the astaxanthin-rich biomass for male and female rats were determined as 14,161 and 17,076mg/kg body weight/day, or 465 and 557mg astaxanthin/kg/day, respectively, the highest dose tested.
- F Sato
F. Sato et al. / Journal of Equine Veterinary Science 35 (2015) 836–842
The apoptosome: signalling platform of cell death
- Sj Riedl
- Gs Salvesen
Riedl SJ, Salvesen GS. The apoptosome: signalling platform of cell
death. Nat Rev Mol Cell Biol 2007;8:405–13.