Audrey Yule Coqueiro

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-1β, 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-1β, 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.

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.

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

BackgroundProbiotic 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.AimTo summarize the therapeutic effects of probiotics in caries and to verify whether this intervention is capable of replacing conventional treatment in human beings.MethodsThe 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.ResultsMost 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.ConclusionProbiotics, 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.

Immunomodulatory role of branched-chain amino acids

Branched-chain amino acids (BCAAs) have been associated with immunomodulation since the mid-1970s and 1980s and have been used in the nutritional therapy of critically ill patients. Evidence shows that BCAAs can directly contribute to immune cell function, aiding recovery of an impaired immune system, as well as improving the nutritional status in cancer and liver diseases. Branched-chain amino acids may also play a role in treatment of patients with sepsis or trauma, contributing to improved clinical outcomes and survival. Branched-chain amino acids, especially leucine, are activators of the mammalian target of rapamycin (mTOR), which, in turn, interacts with several signaling pathways involved in biological mechanisms of insulin action, protein synthesis, mitochondrial biogenesis, inflammation, and lipid metabolism. Although many in vitro and human and animal model studies have provided evidence for the biological activity of BCAAs, findings have been conflicting, and the mechanisms of action of these amino acids are still poorly understood. This review addresses several aspects related to BCAAs, including their transport, oxidation, and mechanisms of action, as well as their role in nutritional therapy and immunomodulation.

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

ABSTRACT 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.

Probiotics for inflammatory bowel diseases: a promising adjuvant treatment

Abstract Inflammatory bowel diseases (IBD) encompass ulcerative colitis (UC), Crohn’s disease (CD) and indeterminate colitis (IC), characterising chronic inflammation in the gastrointestinal tract, associated with changes in the immune system and in the intestinal microbiota. Thus, probiotics may offer an alternative or adjuvant approach to conventional therapy. The present review aims to summarise the mechanisms of action of probiotics in IBD and their therapeutic effects. Most of the studies suggest that probiotics are effective in the treatment of UC, especially when several strains are concomitantly administered. Species of Lactobacillus and Bifidobacterium genres are the most commonly used, and some studies even indicate that it is possible to replace medical therapy with probiotic supplementation. Regarding CD, the results of clinical trials are controversial and do not support the use of probiotics in this disease. In conclusion, probiotic supplementation is a promising adjuvant treatment in UC, but not in CD.

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.