Effects of different branched-chain amino acids supplementation protocols on the inflammatory response of LPS-stimulated RAW 264.7 macrophages.

Although branched-chain amino acids (BCAA) are commonly used as a strategy to recover nutritional status of critically ill patients, recent findings on their role as immunonutrients have been associated with unfavorable outcomes, especially in obese patients. The present study aimed to explore the effects of different BCAA supplementation protocols in the inflammatory response of LPS-stimulated RAW 264.7 macrophages. Cell cultures were divided into five groups, with and without BCAA supplementation, (2 mmol/L of each amino acid). Then, cell cultures followed three different treatment protocols, consisting of a pretreatment (PT), an acute treatment (AT), and a chronic treatment (CT) with BCAA and LPS stimulation (1 µg/mL). Cell viability was analyzed by MTT assay, NO production was assessed by the Griess reaction and IL-6, IL-10, TNF-α and PGE2 synthesis, was evaluated by ELISA. BCAA significantly increased cell viability in AT and CT protocols, and NO and IL-10 synthesis in all treatment protocols. IL-6 synthesis was only increased in PT and CT protocols. TNF-α and PGE2 synthesis were not altered in any of the protocols and groups. BCAA supplementation was able to increase both pro and anti-inflammatory mediators synthesis by RAW 264.7 macrophages, which was influenced by the protocol applied. Moreover, these parameters were significantly increased by isoleucine supplementation, highlighting a potential research field for future studies.

Effects of glutamine and alanine supplementation on muscle fatigue parameters of rats submitted to resistance training.

OBJECTIVE: Although glutamine and alanine have properties that could delay fatigue, recent evidence showed that these amino acids impaired central fatigue markers. Nevertheless, the effect of this intervention on muscle fatigue is unknown. The aim of this study was to investigate the effects of glutamine and alanine supplementation on muscle fatigue parameters in rats submitted to resistance training (RT). METHODS: Wistar rats were distributed into the following groups: sedentary (SED), exercised (CON), exercised and supplemented with alanine (ALA), glutamine and alanine in their free form (G+A) or l-alanyl-l-glutamine (DIP). Trained groups underwent a ladder-climbing exercise for 8 wk. In the last 3 wk of RT, supplementations were offered in water with a 4% concentration. RESULTS: G+A and DIP supplementation increased the muscle content of glutamine and glutamate. DIP administration increased glycogen and lactate dehydrogenase (LDH) concentrations in muscle, whereas ALA and G+A supplementation reduced plasma LDH and creatine kinase levels. All trained groups presented higher levels of muscle glutathione (GSH) than SED. There was no difference between groups in lactate, xanthine, hypoxanthine, thiobarbituric acid reactive substances, 8-isoprostane and GSH in plasma; adenosine monophosphate deaminase, citrate synthase and monocarboxylate transporters 1 and 4 in muscle; and glycogen and GSH in the liver. Moreover, physical performance did not differ between groups. CONCLUSION: Glutamine and alanine supplementation improved muscle fatigue markers without affecting exercise performance.

Glutamine as an Anti-Fatigue Amino Acid in Sports Nutrition.

Glutamine is a conditionally essential amino acid widely used in sports nutrition, especially because of its immunomodulatory role. Notwithstanding, glutamine plays several other biological functions, such as cell proliferation, energy production, glycogenesis, ammonia buffering, maintenance of the acid-base balance, among others. Thus, this amino acid began to be investigated in sports nutrition beyond its effect on the immune system, attributing to glutamine various properties, such as an anti-fatigue role. Considering that the ergogenic potential of this amino acid is still not completely known, this review aimed to address the main properties by which glutamine could delay fatigue, as well as the effects of glutamine supplementation, alone or associated with other nutrients, on fatigue markers and performance in the context of physical exercise. PubMed database was selected to examine the literature, using the keywords combination "glutamine" and "fatigue". Fifty-five studies met the inclusion criteria and were evaluated in this integrative literature review. Most of the studies evaluated observed that glutamine supplementation improved some fatigue markers, such as increased glycogen synthesis and reduced ammonia accumulation, but this intervention did not increase physical performance. Thus, despite improving some fatigue parameters, glutamine supplementation seems to have limited effects on performance.

Effects of Glutamine and Alanine Supplementation on Adiposity, Plasma Lipid Profile, and Adipokines of Rats Submitted to Resistance Training.

Glutamine and alanine are lipogenic and could prevent the effects of resistance training (RT) in reducing adiposity and modulating lipid profile. Thus, we aimed to investigate the effects of RT and glutamine and alanine supplementation, in their free or conjugated form, on relative epididymal adipose tissue (EAT) and brown adipose tissue (BAT) weight, plasma lipid profile, and adipokines in EAT. Thirty Wistar rats, aged two months, were distributed into five groups: control (CTRL), trained (TRN), trained and supplemented with alanine (ALA), glutamine and alanine in their free form (GLN+ALA), or L-alanyl-L-glutamine (DIP). Trained groups underwent a ladder-climbing exercise for eight weeks, with progressive load increase. Supplementations were offered in a solution with a concentration of 4% in the last 21 days of training. Food consumption and body weight gain were decreased in the TRN group compared with CTRL. RT also reduced relative EAT and BAT weight, while supplementations, especially with ALA, increased adipose tissue mass. RT reduced total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-c) (TRN vs. CTRL), whereas glutamine and alanine supplementation increased TC and LDL-c, impairing lipid profile modulation by physical exercise. RT did not affect the concentrations of adipokines in EAT, but DIP supplementation increased interleukin- (IL-) 6 and IL-10. In conclusion, RT reduced adiposity and modulated lipid profile, whereas glutamine and alanine supplementation increased adiposity and impaired lipid profile but increased the concentration of the anti-inflammatory cytokines IL-6 and IL-10 in EAT.

Effects of Glutamine and Alanine Supplementation on Central Fatigue Markers in Rats Submitted to Resistance Training.

Recent evidence suggests that increased brain serotonin synthesis impairs performance in high-intensity intermittent exercise and specific amino acids may modulate this condition, delaying fatigue. This study investigated the effects of glutamine and alanine supplementation on central fatigue markers in rats submitted to resistance training (RT). Wistar rats were distributed in: sedentary (SED), trained (CON), trained and supplemented with alanine (ALA), glutamine and alanine in their free form (G + A), or as dipeptide (DIP). Trained groups underwent a ladder-climbing exercise for eight weeks, with progressive loads. In the last 21 days, supplementations were offered in water with a 4% concentration. Albeit without statistically significance difference, RT decreased liver glycogen, and enhanced the concentrations of plasma glucose, free fatty acids (FFA), hypothalamic serotonin, and ammonia in muscle and the liver. Amino acids affected fatigue parameters depending on the supplementation form. G + A prevented the muscle ammonia increase by RT, whereas ALA and DIP augmented ammonia and glycogen concentrations in muscle. DIP also increased liver ammonia. ALA and G + A reduced plasma FFA, whereas DIP increased this parameter, free tryptophan/total tryptophan ratio, hypothalamic serotonin, and the serotonin/dopamine ratio. The supplementations did not affect physical performance. In conclusion, glutamine and alanine may improve or impair central fatigue markers depending on their supplementation form.

Resistance training alone or combined with leucine supplementation improves the serum lipid profile of diabetic rats, whereas leucine alone does not.

OBJECTIVES: Diabetes mellitus is associated with dyslipidemia, which contributes to a higher risk of thrombosis, atherosclerosis and cardiovascular disease. This study evaluated the effects of leucine and resistance training on the serum lipid profile in rats with streptozotocin-induced diabetes for 8 weeks. METHODS: Wistar rats with neonatal streptozotocin-induced diabetes were treated with leucine supplementation (5%) and/or resistance training (3 days per week) for 8 weeks, and divided in DL (diabetic and leucine), DT (diabetic and resistance training group) and DLT (diabetic, leucine and resistance training) groups. Others 2 groups of animals received isonitrogen AIN-93M diet that was defined as a control diet: group D (diabetic untreated) and group C (non-diabetic). RESULTS: The decrease in serum total cholesterol and increase in high-density lipoprotein cholesterol (HDL-C) was observed in the resistance training-induced diabetic rats when compared with diabetic rats. There was no change in serum lipid profile in leucine-supplemented diabetic rats and no synergistic effect of leucine and resistance training. The fasting glucose levels were reduced in all animals treated compared to D group. CONCLUSION: The diabetic trained rats demonstrate a protective effect of resistance training on the serum lipid profile.

Leucine and resistance training improve hyperglycemia, white adipose tissue loss, and inflammatory parameters in an experimental model of type 1 diabetes.

BACKGROUND: Loss of white adipose tissue (WAT), associated with type 1 diabetes (DM1), contributes to increased chronic systemic inflammation. AIM: The aim of this study was to investigate the effects of leucine supplementation and resistance training (RT) in attenuating WAT loss and improving inflammatory parameters and glucose metabolism in DM1 rats. METHODS: Thirty-two male Wistar rats were distributed into four groups: DA (sedentary and supplemented with non-essential amino acids (NEAA)), DL (sedentary and supplemented with leucine), DTA (submitted to RT and supplemented with NEAA) and DTL (submitted to RT and supplemented with leucine). DM1 was induced by streptozotocin (STZ). An 8-week period of RT consisted of climbing a ladder with a progressively increased load, and supplementation was offered in the feed. RESULTS: Glycemia, polyphagia and polydipsia were lower in DL, DTA and DTL groups compared with the DA group by approximately 20% ( p<.0001), 28% ( p=.004) and 64% ( p<.0001), respectively. Weight of total WAT and retroperitoneal adipose tissue (RPAT) were higher by approximately 21% ( p=.01) and 54% ( p=.0004), respectively, in DL, DTA and DTL groups compared with DA. However, gene expression of adiponectin and leptin in RPAT was only increased by RT (DTA and DTL) compared with DA and DL by approximately 93% ( p<.0001) and 78% ( p=.0002), respectively. Similarly, the levels of adiponectin in the serum, tissue IL-10 (RPAT) and serum IL-10 were only increased in DTA and DTL compared with DA and DL by approximately 31% ( p=.03), 45% ( p=.0009) and 35% ( p=.003), respectively. CONCLUSIONS: Both interventions, isolated or together, reduced hyperglycemia and excessive loss of WAT, but RT was the main factor responsible for attenuating inflammation.

Effects of supplementation with L-glutamine and L-alanine in the body composition of rats submitted to resistance exercise / Efeitos da suplementação com L-glutamina e L-alanina na composição corporal de ratos submetidos ao exercício resistido / Efectos de la suplementación con L-glutamina y L-alanina en la composición corporal de ratones sometidos a ejercicio de resistencia

Abstract We investigated the effects of glutamine and alanine supplementation on body composition of rats submitted to resistance exercise. Wistar rats were submitted to eight-week of resistance exercise, which consisted of climbing a ladder with progressive loads (25-100% of body weight). In the last 21 days of training, animals were supplemented with L-glutamine and L-alanine, as a dipeptide or in their free form (DIP, GLN + ALA and ALA groups), or water (SED and CTRL groups). RE attenuated body weight gain and lipid contents of CTRL group (p < 0.05 vs. SED) and DIP supplementation promoted an increase in tibialis muscle weight, as well as in protein content (p < 0.05 vs. CTRL). Taken together, our data indicated that resistance exercise improves body composition and dipeptide potentiated the muscle hypertrophic effect.

Resumo Foram investigados os efeitos da suplementação com glutamina e alanina na composição corporal de ratos submetidos a exercício resistido. Ratos Wistar foram submetidos, durante oito semanas, ao exercício resistido, que consistia em subir uma escada com cargas progressivas (25 a 100% do peso corporal). Nos últimos 21 dias de treinamento, os animais foram suplementados com L-glutamina e L-alanina, como dipeptídeo ou em sua forma livre (DIP, GLN + ALA ALA e grupos) ou água (grupos SED e CTRL). Exercício resistido atenuou o ganho de peso corporal e conteúdo lipídico do CTRL (p < 0,05 vs. SED) e o DIP promoveu aumento no peso do músculo tibial, bem como no teor de proteína (p < 0,05 vs. CTRL). Os nossos dados indicam que o exercício resistido, melhora a composição corporal e dipeptídeo potencializa o efeito hipertrófico muscular.

Resumen Se investigaron los efectos de la glutamina y la alanina en la composición corporal de ratones sometidos a ejercicio de resistencia. Algunos ratones Wistar fueron sometidos a 8 semanas de ejercicio de resistencia, que consistía en subir una escalera con cargas progresivas (del 25 al 100% de la masa corporal). En los últimos 21 días, los animales recibieron un suplemento de L-glutamina y L-alanina, en forma de dipéptido o en su forma libre (grupos DIP, GLN + ALA y ALA) o agua (grupos SED y CTRL). El ejercicio de resistencia redujo el aumento de masa corporal y la concentración de lípidos del CTRL (p <0,05 vs. SED). La suplementación con DIP promovió un aumento de peso del músculo tibial, así como en el contenido de proteína (p < 0,05 frente a CTRL). Nuestros resultados indican que el ejercicio de resistencia mejora la composición corporal y el DIP potencia el efecto hipertrófico.

Effects of leucine supplementation and resistance training on myopathy of diabetic rats.

Leucine supplementation and resistance training positively influence the protein translation process and the cell signaling mTOR (mammalian target of rapamycin) pathway that regulates muscle protein balance and muscle remodeling, and thus may be therapeutic to diabetic myopathy. However, the effect of a combined intervention has not been well studied. Forty male Wistar rats were divided into five groups, control (C), diabetic control (D), diabetic + trained (DT), diabetic + L-leucine (DL), diabetic + L-leucine + trained (DLT). The supplementation of 5% leucine in chow, and resistance training were conducted for 8 weeks postweaning of rats. The extensor digitorum longus was used to assess signaling proteins involved in muscle protein synthesis, and the gastrocnemius and soleus were used for determination of muscle weight. Blood samples were collected for biochemical assays. Strength and ambulation tests were employed to evaluate motor performance. Results showed that both leucine supplementation and resistance training elevated the activity of mTOR-p70S6K in diabetic rats (P < 0.05). Moreover, though leucine supplementation in combination with resistance training demonstrated synergistic effects on p70S6K (P < 0.05), both treatments were capable of recovering motor performance (P < 0.05). In conclusion, 5% leucine supplementation combined with resistance training has the potential to attenuate muscle loss and motor performance decrements in diabetic rats, at least in part through increased protein synthesis.

Conjugated linoleic acid supplementation does not maximize motor performance and abdominal and trunk fat loss induced by aerobic training in overweight women / Suplementação de ácido linoléico conjugado não maximiza o desempenho motor e a perda de gordura de tronco e abdominal induzida pelo treinamento aeróbio em mulheres com excesso de peso

ABSTRACT Objective: To analyze the effect of eight weeks of conjugated linoleic acid supplementation on physical performance, and trunk and abdominal fat in overweight women submitted to an aerobic training program. Methods: Twenty-eight overweight women (body mass index ³25 kg/m2) were divided randomly and double-blindly to receive conjugated linoleic acid or placebo, both associated with an aerobic exercise program (frequency = three times a week, duration=30 min/session, intensity=80% of maximum heart rate). Conjugated linoleic acid (3.2 g) and placebo (4.0 g) supplements were consumed daily (four capsules) for eight weeks. Maximum speed and time to exhaustion were determined in incremental treadmill test. Trunk fat was estimated by dual-energy X-Ray absorptiometry. Waist circumference was used as indicator of abdominal fat. Results: Main effect of time (p<0.05) showed increased maximum speed (conjugated linoleic acid=+6.3% vs. placebo=+7.5%) and time to exhaustion (conjugated linoleic acid=+7.1% vs. placebo=+8.6%) in the incremental treadmill test, with no differences between the groups (p>0.05). Similarly, significant reductions (p<0.05) in trunk fat (conjugated linoleic acid=-1.7% vs. placebo=-1.5%) and abdominal fat (conjugated linoleic acid=-4.7% vs. placebo=-4.0%) were found after eight weeks of intervention, with no differences between the groups (p>0.05). Conclusion: The results of this study suggest that conjugated linoleic acid supplementation does not maximize motor performance, and loss of body and abdominal fat induced by aerobic training in overweight women.

RESUMO Objetivo: Analisar o efeito de oito semanas de suplementação de ácido linoleico conjugado sobre o desempenho físico, a gordura de tronco e abdominal em mulheres com excesso de peso submetidas a um programa de treinamento aeróbio. Métodos: Vinte e oito mulheres com excesso de peso (índice de massa corporal ³ 25 kg/m2) foram separadas aleatoriamente por meio de um delineamento duplo cego para receber suplementação de ácido linoleico ou placebo associado a um programa de exercícios aeróbios (frequência = três sessões semanais, duração=30 min/sessão, intensidade=80% da frequência cardíaca máxima). A suplementação de ácido linoleico (3,2 g) ou de placebo (4,0 g) foi consumida diariamente (quatro cápsulas), durante oito semanas. As variáveis velocidade máxima atingida e tempo de permanência até a exaustão foram determinadas em teste incremental em esteira. A gordura de tronco foi estimada por absortometria radiológica de dupla energia. A circunferência de cintura foi utilizada como indicador de gordura abdominal. Resultados: Efeito principal do tempo (p<0,05) revelou aumento da velocidade máxima atingida (suplementação de ácido linoleico=+6,3% versus placebo=+7,5%) e tempo de duração até a exaustão (suplementação de ácido linoleico=+7,1% versus placebo=+8,6%) em teste incremental em esteira, sem diferenças entre os grupos (p>0,05). De forma similar, uma redução significante (p<0,05) na gordura relativa de tronco (suplementação de ácido linoleico=-1,7% versus placebo=-1,5%) e na gordura abdominal (suplementação de ácido linoleico=-4,7% versus placebo=-4,0%) foi encontrada após oito semanas de intervenção, sem diferenças entre os grupos (p>0,05). Conclusão: Os resultados do presente estudo sugerem que a suplementação de ácido linoleico não maximiza o desempenho motor e a redução da gordura de tronco e abdominal induzida pelo treinamento aeróbio em mulheres com excesso de peso.

l-glutamine and l-alanine supplementation increase glutamine-glutathione axis and muscle HSP-27 in rats trained using a progressive high-intensity resistance exercise.

In this study we investigated the chronic effects of oral l-glutamine and l-alanine supplementation, either in their free or dipeptide form, on glutamine-glutathione (GLN-GSH) axis and cytoprotection mediated by HSP-27 in rats submitted to resistance exercise (RE). Forty Wistar rats were distributed into 5 groups: sedentary; trained (CTRL); and trained supplemented with l-alanyl-l-glutamine, l-glutamine and l-alanine in their free form (GLN+ALA), or free l-alanine (ALA). All trained animals were submitted to a 6-week ladder-climbing protocol. Supplementations were offered in a 4% drinking water solution for 21 days prior to euthanasia. Plasma glutamine, creatine kinase (CK), myoglobin (MYO), and erythrocyte concentration of reduced GSH and glutathione disulfide (GSSG) were measured. In tibialis anterior skeletal muscle, GLN-GSH axis, thiobarbituric acid reactive substances (TBARS), and the expression of heat shock factor 1 (HSF-1), 27-kDa heat shock protein (HSP-27), and glutamine synthetase were determined. In CRTL animals, high-intensity RE reduced muscle glutamine levels and increased GSSG/GSH rate and TBARS, as well as augmented plasma CK and MYO levels. Conversely, l-glutamine-supplemented animals showed an increase in plasma and muscle levels of glutamine, with a reduction in GSSG/GSH rate, TBARS, and CK. Free l-alanine administration increased plasma glutamine concentration and lowered muscle TBARS. HSF-1 and HSP-27 were high in all supplemented groups when compared with CTRL (p < 0.05). The results presented herein demonstrate that l-glutamine supplemented with l-alanine, in both a free or dipeptide form, improve the GLN-GSH axis and promote cytoprotective effects in rats submitted to high-intensity RE training.

Exercise dependence and its relationship with supplementation at gyms in Brazil

Introduction: Brazil is the second country in the world with the largest number of gyms, currently accounting for approximately 30 thousand units. There is increasing evidence that a significant part of gym-goers develop excessive commitment to practicing physical exercises, which may even generate pathological dependence. Aim: To determine the association between physical exercise addiction (ED) and supplement intake among gym-goers. Method: The exercise addiction scale was employed for gym-goers older than 19 years of both sexes. Individual interview was made by using nutritional history to determine supplement intake profile; data related to anthropometry and participation in the gym were also assessed. Results: The frequency of ED at gyms was 66.5% and the prevalence of supplementation was 51.5%, while the chances for an exercise addict to be a supplement consumer were estimated at 4.53. Conclusion: The relationship between ED and supplement intake was proven, constituting an alert for health professionals, who should consider the risk factors for the development of more severe signs and symptoms, including obsessive weight control by means of excessive practice of exercises, diets with no nutritional basis and unnecessary supplementation. It is recommended to include nutritional assessment among the instruments to detect ED and supplementation so that, if necessary, campaigns can be promoted to elucidate diets, healthy body composition patterns and drastic changes in eating patterns, as well as other issues related to nutritional care.

Determination of the anti-inflammatory and cytoprotective effects of l-glutamine and l-alanine, or dipeptide, supplementation in rats submitted to resistance exercise.

We evaluated the effects of chronic oral supplementation with l-glutamine and l-alanine in their free form or as the dipeptide l-alanyl-l-glutamine (DIP) on muscle damage, inflammation and cytoprotection, in rats submitted to progressive resistance exercise (RE). Wistar rats (n 8/group) were submitted to 8-week RE, which consisted of climbing a ladder with progressive loads. In the final 21 d before euthanasia, supplements were delivered in a 4 % solution in drinking water. Glutamine, creatine kinase (CK), lactate dehydrogenase (LDH), TNF-α, specific IL (IL-1ß, IL-6 and IL-10) and monocyte chemoattractant protein-1 (MCP-1) levels were evaluated in plasma. The concentrations of glutamine, TNF-α, IL-6 and IL-10, as well as NF-κB activation, were determined in extensor digitorum longus (EDL) skeletal muscle. HSP70 level was assayed in EDL and peripheral blood mononuclear cells (PBMC). RE reduced glutamine concentration in plasma and EDL (P<0·05 v. sedentary group). However, l-glutamine supplements (l-alanine plus l-glutamine (GLN+ALA) and DIP groups) restored glutamine levels in plasma (by 40 and 58 %, respectively) and muscle (by 93 and 105 %, respectively). GLN+ALA and DIP groups also exhibited increased level of HSP70 in EDL and PBMC, consistent with the reduction of NF-κB p65 activation and cytokines in EDL. Muscle protection was also indicated by attenuation in plasma levels of CK, LDH, TNF-α and IL-1ß, as well as an increase in IL-6, IL-10 and MCP-1. Our study demonstrates that chronic oral l-glutamine treatment (given with l-alanine or as dipeptide) following progressive RE induces cyprotective effects mediated by HSP70-associated responses to muscle damage and inflammation.

Exercise dependence and its relationship with supplementation at gyms in Brazil / Dependencia de ejercicio y su relación con la administración de suplementos en los gimnasios de Brasil

Introduction: Brazil is the second country in the world with the largest number of gyms, currently accounting for approximately 30 thousand units. There is increasing evidence that a significant part of gym-goers develop excessive commitment to practicing physical exercises, which may even generate pathological dependence. Aim: To determine the association between physical exercise addiction (ED) and supplement intake among gym-goers. Method: The exercise addiction scale was employed for gym-goers older than 19 years of both sexes. Individual interview was made by using nutritional history to determine supplement intake profile; data related to anthropometry and participation in the gym were also assessed. Results: The frequency of ED at gyms was 66.5% and the prevalence of supplementation was 51.5%, while the chances for an exercise addict to be a supplement consumer were estimated at 4.53. Conclusion: The relationship between ED and supplement intake was proven, constituting an alert for health professionals, who should consider the risk factors for the development of more severe signs and symptoms, including obsessive weight control by means of excessive practice of exercises, diets with no nutritional basis and unnecessary supplementation. It is recommended to include nutritional assessment among the instruments to detect ED and supplementation so that, if necessary, campaigns can be promoted to elucidate diets, healthy body composition patterns and drastic changes in eating patterns, as well as other issues related to nutritional care (AU)

Introducción: Brasil es el segundo país del mundo con el mayor número de gimnasios y actualmente representa aproximadamente 30 mil unidades. Cada vez hay más evidencias de que una parte significativa de los practicantes de actividad física desarrollan un compromiso exagerado con esta actividad, que incluso pueden generar dependencia patológica. Objetivo: determinar la asociación entre la práctica exagerada de ejercicio físico (ED) y el consumo de suplementos entre los practicantes. Método: se utilizó la escala de adicción al ejercicio en practicantes mayores de 19 años, de ambos sexos. Fue realizada una entrevista individual para determinar históricamente el consumo de suplementos; también se evaluaron los resultados de antropometría y la frecuencia de participación en el gimnasio. Resultados: la frecuencia de la práctica en el gimnasio fue del 66,5% y la prevalencia de la suplementación fue de 51,5%, la posibilidades de un adicto al ejercicio ser un consumidor de suplemento se estima en 4,53. Conclusión: la relación entre la adicción al ejercicio y el consumo de suplemento fue comprobada, constituyendo una alerta para los profesionales de la salud, que deben tener en cuenta los factores de riesgo para el desarrollo de los signos más graves y síntomas, incluyendo el control de peso obsesivo por medio de la práctica intensa de ejercicios físicos, consumo de dietas inadecuadas y uso de suplementos nutricionales. Se recomienda que la evaluación nutricional se complemente de otras determinaciones para detectar la adicción al ejercicio y el uso de suplementación nutricional. Si es necesario, se pueden promover campañas para avalar las dietas consumidas, la composición corporal ideal y detectar los cambios drásticos en la alimentación, así como otras cuestiones relacionadas con el cuidado nutricional en general (AU)

Effect of Conjugated Linoleic Acid Associated With Aerobic Exercise on Body Fat and Lipid Profile in Obese Women: A Randomized, Double-Blinded, and Placebo-Controlled Trial.

The aim of this study was to analyze the effects of 8 weeks of conjugated linoleic acid (CLA) supplementation associated with aerobic exercise on body fat and lipid profile on obese women. We performed a randomized, double-blinded and placebo-controlled trial with 28 obese women who received 3.2 g/day of CLA or 4 g/day of olive oil (placebo group) while performing an 8-week protocol of aerobic exercise. Dietary intake (food record), body fat (dual-energy X-ray absorptiometry), and biochemical analysis (blood sample) were assessed before and after the intervention period. Independent of CLA supplementation, both groups improved (p < .05) oxygen uptake (CLA group, 13.2%; PLC group, 14.8%), trunk fat (CLA group, -1.0%; PLC group, -0.5%), leg fat (CLA group, -1.0%; PLC group, -1.6%), and total body fat (CLA group, -1.7%; PLC group, -1.3%) after the 8-week intervention. No main effect or Group × Time interaction was found for total cholesterol, triglycerides, and plasma lipoproteins (p > .05). We conclude that CLA supplementation associated with aerobic exercise has no effect on body fat reduction and lipid profile improvements over placebo in young adult obese women.

L-glutamine supplementations enhance liver glutamine-glutathione axis and heat shock factor-1 expression in endurance-exercise trained rats.

Liver L-glutamine is an important vehicle for the transport of ammonia and intermediary metabolism of amino acids between tissues, particularly under catabolic situations, such as high-intensity exercise. Hence, the aim of this study was to investigate the effects of oral supplementations with L-glutamine in its free or dipeptide forms (with L-alanine) on liver glutamine-glutathione (GSH) axis, and 70 kDa heat shock proteins (HSP70)/heat shock transcription factor 1 (HSF1) expressions. Adult male Wistar rats were 8-week trained (60 min/day, 5 days/week) on a treadmill. During the last 21 days, the animals were daily supplemented with 1 g of L-glutamine/kg body weight per day in either l-alanyl-L-glutamine dipeptide (DIP) form or a solution containing L-glutamine and l-alanine in their free forms (GLN+ALA) or water (controls). Exercise training increased cytosolic and nuclear HSF1 and HSP70 expression, as compared with sedentary animals. However, both DIP and GLN+ALA supplements enhanced HSF1 expression (in both cytosolic and nuclear fractions) in relation to exercised controls. Interestingly, HSF1 rises were not followed by enhanced HSP70 expression. DIP and GLN+ALA supplements increased plasma glutamine concentrations (by 62% and 59%, respectively) and glutamine to glutamate plasma ratio in relation to trained controls. This was in parallel with a decrease in plasma ammonium levels. Supplementations increased liver GSH (by 90%), attenuating the glutathione disulfide (GSSG) to GSH ratio, suggesting a redox state protection. In conclusion, oral administration with DIP and GLN+ALA supplements in endurance-trained rats improve liver glutamine-GSH axis and modulate HSF1 pathway.

Yerba Mate (Ilex paraguariensis) modulates NF-kappaB pathway and AKT expression in the liver of rats fed on a high-fat diet.

To investigate the effect of Yerba Mate (YM) aqueous extract intake on the NF-kB pathway and AKT expression in the liver, muscle, and adipose tissue of rats submitted to a high-fat diet (HFD). Male Wistar rats were fed a control (CON) (n = 24) or a HFD (n = 24) for 12 weeks. Afterwards, rats received YM daily (1 g/kg body weight) for 4 weeks. Intake of YM aqueous extract reduced body weight gain (p < 0.05) and total blood cholesterol (p < 0.05) in the HFD group in comparison to the non-treated HFD group. HFD group demonstrated an increased glycemic response at 5 and 10 min after insulin injection. YM decreased the ratio between phosphorylated and total kinase inhibitor of κB (IKK), increased the ratio of phosphorylated to total form of protein kinase B (AKT) and reduced NF-κB phosphorylation in the liver of the HFD group. Our data suggest a beneficial role of YM in improving metabolic dysfunctions induced by HFD.

Oral free and dipeptide forms of glutamine supplementation attenuate oxidative stress and inflammation induced by endotoxemia.

OBJECTIVE: The aim of the present study was to determine the effects of oral supplementation with L-glutamine plus L-alanine (GLN+ALA), both in the free form and L-alanyl-L-glutamine dipeptide (DIP) in endotoxemic mice. METHODS: B6.129 F2/J mice were subjected to endotoxemia (Escherichia coli lipopolysaccharide [LPS], 5 mg/kg, LPS group) and orally supplemented for 48 h with either L-glutamine (1 g/kg) plus L-alanine (0.61 g/kg) (GLN+ALA-LPS group) or 1.49 g/kg DIP (DIP-LPS group). Plasma glutamine, cytokines, and lymphocyte proliferation were measured. Liver and skeletal muscle glutamine, glutathione (GSH), oxidized GSH (GSSG), tissue lipoperoxidation (TBARS), and nuclear factor (NF)-κB-interleukin-1 receptor-associated kinase 1 (IRAK1)-Myeloid differentiation primary response gene 88 pathway also were determined. RESULTS: Endotoxemia depleted plasma (by 71%), muscle (by 44%), and liver (by 49%) glutamine concentrations (relative to the control group), which were restored in both GLN+ALA-LPS and DIP-LPS groups (P < 0.05). Supplemented groups reestablished GSH content, intracellular redox status (GSSG/GSH ratio), and TBARS concentration in muscle and liver (P < 0.05). T- and B-lymphocyte proliferation increased in supplemented groups compared with controls and LPS group (P < 0.05). Tumor necrosis factor-α, interleukin (IL)-6, IL-1 ß, and IL-10 increased in LPS group but were attenuated by the supplements (P < 0.05). Endotoxemic mice exhibited higher muscle gene expression of components of the NF-κB pathway, with the phosphorylation of IκB kinase-α/ß. These returned to basal levels (relative to the control group) in both GLN+ALA-LPS and DIP-LPS groups (P < 0.05). Higher mRNA of IRAK1 and MyD88 were observed in muscle of LPS group compared with the control and supplemented groups (P < 0.05). CONCLUSION: Oral supplementations with GLN+ALA or DIP are effective in attenuating oxidative stress and the proinflammatory responses induced by endotoxemia in mice.

Oral supplementations with free and dipeptide forms of L-glutamine in endotoxemic mice: effects on muscle glutamine-glutathione axis and heat shock proteins.

Sepsis is a leading cause of death in intensive care units worldwide. Low availability of glutamine contributes to the catabolic state of sepsis. L-Glutamine supplementation has antioxidant properties and modulates the expression of heat shock proteins (HSPs). This study investigated the effects of oral supplementation with L-glutamine plus L-alanine (GLN+ALA), both in the free form and L-alanyl-L-glutamine dipeptide (DIP), on glutamine-glutathione (GSH) axis and HSPs expression in endotoxemic mice. B6.129F2/J mice were subjected to endotoxemia (lipopolysaccharides from Escherichia coli, 5 mg.kg(-1), LPS group) and orally supplemented for 48 h with either L-glutamine (1 g.kg(-1)) plus L-alanine (0.61 g.kg(-1)) (GLN+ALA-LPS group) or 1.49 g.kg(-1) of DIP (DIP-LPS group). Endotoxemia reduced plasma and muscle glutamine concentrations [relative to CTRL group] which were restored in both GLN+ALA-LPS and DIP-LPS groups (P<.05). In supplemented groups were re-established GSH content and intracellular redox status (GSSG/GSH ratio) in circulating erythrocytes and muscle. Thiobarbituric acid reactive substance was 4-fold in LPS treated mice relative to the untreated CTRL group, and plasma TNF-α and IL-1ß levels were attenuated by the supplements. Heat shock proteins 27, 70 and 90 (protein and mRNA) were elevated in the LPS group and were returned to basal levels (relative to CTRL group) in both GLN+ALA-LPS and DIP-LPS groups. Supplementations to endotoxemic mice resulted in up-regulation of GSH reductase, GSH peroxidase and glutamate cysteine ligase mRNA expression in muscle. In conclusion, oral supplementations with GLN+ALA or DIP are effective in reversing the conditions of LPS-induced deleterious impact on glutamine-GSH axis in mice under endotoxemia.

Leucine improves protein nutritional status and regulates hepatic lipid metabolism in calorie-restricted rats.

Several studies have highlighted the potential of leucine supplementation for the treatment of metabolic diseases including type 2 diabetes and obesity. Caloric restriction is a common approach to improve the health in diabetic and obese subjects. However, very few studies assessed the effects of leucine supplementation in calorie-restricted animals. Rats were subjected to a 30% calorie-restricted diet for 6 weeks to study the effects of leucine supplementation on protein status markers and lipid metabolism. Caloric restriction reduced the body weight. However, increased leucine intake preserved body lean mass and protein mass and improved protein anabolism as indicated by the increased circulating levels of albumin and insulin-like growth factor-1 (IGF-1), and the liver expression of albumin and IGF-1 messenger RNA. Leucine supplementation also increased the circulating levels of interleukin-6 and leptin but did not affect the tumour necrosis factor-α and monocyte chemotactic protein-1 concentrations. Ketone bodies were increased in rats consuming a leucine-rich diet, but we observed no changes in cholesterol or triglycerides concentrations. Caloric restriction reduced the liver expression of peroxisome proliferator activated receptor-α and glucose-6-phosphatase, whereas leucine supplementation increased the liver expression of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA) reductase and sterol regulatory element-binding transcription factor 1. A leucine-rich diet during caloric restriction preserved whole body protein mass and improved markers of protein anabolism. In addition, leucine modulated the hepatic lipid metabolism. These results indicate that increased leucine intake may be useful in preventing excessive protein waste in conditions of large weight loss.