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, in their free form or as dipeptide, on fatigue parameters of rats submitted to resistance training / Efeitos da suplementação com glutamina e alanina, na forma livre ou como dipeptídeo, sobre parâmetros de fadiga de ratos submetidos ao treinamento resistido

Fatigue is defined as the inability to maintain muscle power and strength, impairing performance. Nutritional interventions have been used to delay this phenomenon, such as glutamine and alanine supplementation. These amino acids might attenuate several causes of fatigue, since they are important energy substrates, transport ammonia avoiding the accumulation of this toxic metabolite and attenuate muscle damage and oxidative stress. Thus, the aim of this study was to evaluate the effects of glutamine and alanine supplementation on central and muscle fatigue parameters of rats submitted to resistance training (RT). Forty adult Wistar rats (60 days) were distributed into five groups: SED (sedentary, receiving water), CON (trained, receiving water), ALA, G+A and DIP (trained and supplemented with alanine, glutamine and alanine in their free form, and Lalanyl-L-glutamine, respectively). Trained groups underwent a ladder-climbing exercise, with progressive loads, for eight weeks. Supplements were diluted in water to a 4% concentration and offered ad libitum during the last 21 days of experiment. RT increased plasma glucose, the muscle concentrations of ammonia and glutathione (GSH) and the muscle damage parameters - plasma creatine kinase (CK) and lactate dehydrogenase (LDH), whereas decreased muscle glycogen. G+A supplementation prevented the increase of muscle ammonia by RT, while ALA and G+A administration reduced plasma CK and LDH, and DIP supplementation increased the muscle content of glycogen and LDH. Contrary to expectations, DIP administration increased central fatigue parameters, such as plasma concentration of free fatty acids (FFA), hypothalamic content of serotonin and serotonin/dopamine ratio. Despite these results, there was no difference between groups in the maximum carrying capacity (MCC) tests. In conclusion, supplementation with glutamine and alanine improves some fatigue parameters, but does not affect physical performance of rats submitted to RT

O termo fadiga é definido como a incapacidade de manutenção da força e da potência musculares, prejudicando a performance. Intervenções nutricionais têm sido utilizadas para retardar este fenômeno, como a suplementação com glutamina e alanina. Estes aminoácidos poderiam atenuar diversas causas de fadiga, pois são importantes substratos energéticos, carreiam amônia evitando o acúmulo deste metabólito tóxico e atenuam a lesão muscular e o estresse oxidativo. Logo, o objetivo deste estudo foi avaliar os efeitos da suplementação com glutamina e alanina sobre parâmetros de fadiga central e muscular em ratos submetidos ao treinamento resistido (TR). Foram utilizados 40 ratos Wistar adultos (60 dias de idade), distribuídos nos grupos: SED (não treinados, recebendo água), CON (treinados, recebendo água), ALA, G+A e DIP (treinados e suplementados com alanina, glutamina e alanina livres, e L-alanil-L-glutamina, respectivamente). Os grupos treinados realizaram um exercício de escalada em escada, com aumento progressivo de carga, durante oito semanas. A suplementação foi diluída a 4% em água e ofertada via oral, ad libitum, durante os últimos 21 dias de experimento. O TR aumentou a glicemia, as concentrações musculares de amônia e de glutationa (GSH) e os parâmetros de lesão muscular - creatina quinase (CK) e lactato desidrogenase (LDH) no plasma, enquanto reduziu o glicogênio no músculo. A suplementação com G+A preveniu o aumento de amônia muscular promovido pelo TR, enquanto a administração de ALA e G+A reduziu as concentrações de CK e LDH no plasma, e a suplementação com DIP aumentou o conteúdo muscular de glicogênio e de LDH. Ao contrário do esperado, a administração de DIP aumentou parâmetros de fadiga central, como as concentrações plasmáticas de ácidos graxos livres, o conteúdo hipotalâmico de serotonina e a razão serotonina/dopamina. Apesar disso, não houve diferença entre os grupos nos testes de carga máxima. Em conclusão, a suplementação com glutamina e alanina melhora alguns parâmetros de fadiga, mas não afeta o desempenho físico em ratos submetidos ao TR

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.

Probiotic supplementation in dental caries: is it possible to replace conventional treatment?

BACKGROUND: Probiotic supplementation alters oral microbiota composition and could reduce the risk or treat oral cavity diseases, such as dental caries, which are considered a public health problem. Aim: To summarize the therapeutic effects of probiotics in caries and to verify whether this intervention is capable of replacing conventional treatment in human beings. METHODS: he search of the studies was carried out in the PubMed database in October 2017, without limiting the publication period. The keyword combination used was "Probiotics" and "Dental caries." Forty-two original articles that evaluated the effect of probiotic supplementation on caries treatment in humans were included in the study. RESULTS: Most of the studies evaluated bacteria of the genus Lactobacillus. The main therapeutic effects are related to the reduction of the Streptococcus mutans oral count, increased Lactobacillus oral count, and reduction in the incidence of caries. Evidence on the therapeutic effects of the Bifidobacterium and Streptococcus genres is scarce and conflicting, making it difficult to recommend them for use in clinical practice. Only a few studies administered probiotics without conventional treatments, such as fluoride. Although probiotic supplementation presented interesting properties, the therapeutic effects are more pronounced when probiotic and fluoride are applied together. CONCLUSION: Probiotics, especially of the Lactobacillus genus, can be used as adjuvants, but cannot replace the conventional treatments of caries.

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.

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.

Probiotic supplementation in sports and physical exercise: Does it present any ergogenic effect?

BACKGROUND: Probiotics are live microorganisms that promote health benefits to the host. Evidence indicates that some probiotic strains play an immunomodulatory role and reduce the incidence of respiratory and gastrointestinal infections in athletes and in physical activity practitioners. For this reason, probiotic supplementation could indirectly improve exercise performance. However, recent studies have observed direct ergogenic effects of probiotics, but the mechanisms of action are poorly elucidated. OBJECTIVE: In this study, we aim to synthesize available knowledge on the effect of probiotics on physical exercise, identify the mechanisms of action by which probiotics could improve performance directly and indirectly, and verify whether probiotics have any ergogenic effect. METHODS: The study was performed in the PubMed database in February 2017, without limitation as to the publication period. The keyword combinations used were: 'Probiotics' and 'Sports' ( n = 17 articles), 'Probiotics' and 'Exercise' ( n = 26 articles) and 'Probiotics' and 'Athletes' ( n = 11 articles). RESULTS: Of the 16 studies evaluated, only six applied performance tests, of which only two demonstrated that probiotic supplementation increases performance, but one of them was performed with mice. CONCLUSIONS: According to the studies evaluated, probiotic supplementation does not present ergogenic effect, however, considering the small number of studies, this subject should be better investigated.

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.

Pre-season dietary intake of professional soccer players.

BACKGROUND: Despite the well-documented importance of nutrition in optimizing performance and health, the dietary intake of soccer players has attracted little attention. AIM: We aimed to assess the pre-season dietary intake of professional soccer players and its adequacy in macro and micronutrients. METHODS: The pre-season dietary intake of 19 male athletes was assessed using a semi-structured 3-day food record. To determine dietary adequacy and excess, energy and macronutrient intake were compared with the Brazilian dietary reference values for athletes, and micronutrients were compared with the Estimated Average Requirement - EAR (minimum recommendation) and Tolerable Upper Intake Level - UL (maximum recommendation). RESULTS: Mean daily energy intake (40.74±12.81 kcal/kg) was adequate. However, there was a low carbohydrate intake (5.44±1.86 g/kg/day) and a high amount of protein and fat (1.91±0.75 and 1.27±0.50 g/kg/day, respectively). Sodium intake (3141.77±939.76 mg/day) was higher than UL (2300 mg/day), while the majority of players showed daily intake of vitamin A (74%), vitamin D (100%), folate (58%), calcium and magnesium (68%) below the EAR (625, 10 and 320 µg/day, 800 and 330 mg/day, respectively). CONCLUSION: The dietary intake of professional soccer players was adequate in energy, but inadequate in macro and micronutrients, which suggests the need to improve nutritional practices to sustain the physical demands of soccer during pre-season.

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.