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1.
Biomolecules ; 13(7)2023 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-37509183

RESUMO

Uveal melanoma (UVM) is a highly aggressive ocular cancer with limited therapeutic options and poor prognosis particularly for patients with liver metastasis. As such, the identification of new prognostic biomarkers is critical for developing effective treatment strategies. In this study, we aimed to investigate the potential of an ultraviolet light response gene signature to predict the prognosis of UVM patients. Our approach involved the development of a prognostic model based on genes associated with the cellular response to UV light. By employing this model, we generated risk scores to stratify patients into high- and low-risk groups. Furthermore, we conducted differential expression analysis between these two groups and explored the estimation of immune infiltration. To validate our findings, we applied our methodology to an independent UVM cohort. Through our study, we introduced a novel survival prediction tool and shed light on the underlying cellular processes within UVM tumors, emphasizing the involvement of immune subsets in tumor progression.


Assuntos
Melanoma , Neoplasias Uveais , Humanos , Raios Ultravioleta , Melanoma/patologia , Neoplasias Uveais/genética , Neoplasias Uveais/metabolismo , Neoplasias Uveais/patologia , Olho/metabolismo
2.
J Int Soc Sports Nutr ; 20(1): 2237952, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37498180

RESUMO

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).


Assuntos
Desempenho Atlético , Café , Masculino , Feminino , Humanos , Cafeína/farmacologia , Desempenho Atlético/fisiologia , Ácido Clorogênico/análise , Exercício Físico
3.
J Int Soc Sports Nutr ; 20(1): 2204066, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37221858

RESUMO

Based on a comprehensive review and critical analysis of the literature regarding the nutritional concerns of female athletes, conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: 1. Female athletes have unique and unpredictable hormone profiles, which influence their physiology and nutritional needs across their lifespan. To understand how perturbations in these hormones affect the individual, we recommend that female athletes of reproductive age should track their hormonal status (natural, hormone driven) against training and recovery to determine their individual patterns and needs and peri and post-menopausal athletes should track against training and recovery metrics to determine the individuals' unique patterns. 2. The primary nutritional consideration for all athletes, and in particular, female athletes, should be achieving adequate energy intake to meet their energy requirements and to achieve an optimal energy availability (EA); with a focus on the timing of meals in relation to exercise to improve training adaptations, performance, and athlete health. 3. Significant sex differences and sex hormone influences on carbohydrate and lipid metabolism are apparent, therefore we recommend first ensuring athletes meet their carbohydrate needs across all phases of the menstrual cycle. Secondly, tailoring carbohydrate intake to hormonal status with an emphasis on greater carbohydrate intake and availability during the active pill weeks of oral contraceptive users and during the luteal phase of the menstrual cycle where there is a greater effect of sex hormone suppression on gluconogenesis output during exercise. 4. Based upon the limited research available, we recommend that pre-menopausal, eumenorrheic, and oral contraceptives using female athletes should aim to consume a source of high-quality protein as close to beginning and/or after completion of exercise as possible to reduce exercise-induced amino acid oxidative losses and initiate muscle protein remodeling and repair at a dose of 0.32-0.38 g·kg-1. For eumenorrheic women, ingestion during the luteal phase should aim for the upper end of the range due to the catabolic actions of progesterone and greater need for amino acids. 5. Close to the beginning and/or after completion of exercise, peri- and post-menopausal athletes should aim for a bolus of high EAA-containing (~10 g) intact protein sources or supplements to overcome anabolic resistance. 6. Daily protein intake should fall within the mid- to upper ranges of current sport nutrition guidelines (1.4-2.2 g·kg-1·day-1) for women at all stages of menstrual function (pre-, peri-, post-menopausal, and contraceptive users) with protein doses evenly distributed, every 3-4 h, across the day. Eumenorrheic athletes in the luteal phase and peri/post-menopausal athletes, regardless of sport, should aim for the upper end of the range. 7. Female sex hormones affect fluid dynamics and electrolyte handling. A greater predisposition to hyponatremia occurs in times of elevated progesterone, and in menopausal women, who are slower to excrete water. Additionally, females have less absolute and relative fluid available to lose via sweating than males, making the physiological consequences of fluid loss more severe, particularly in the luteal phase. 8. Evidence for sex-specific supplementation is lacking due to the paucity of female-specific research and any differential effects in females. Caffeine, iron, and creatine have the most evidence for use in females. Both iron and creatine are highly efficacious for female athletes. Creatine supplementation of 3 to 5 g per day is recommended for the mechanistic support of creatine supplementation with regard to muscle protein kinetics, growth factors, satellite cells, myogenic transcription factors, glycogen and calcium regulation, oxidative stress, and inflammation. Post-menopausal females benefit from bone health, mental health, and skeletal muscle size and function when consuming higher doses of creatine (0.3 g·kg-1·d-1). 9. To foster and promote high-quality research investigations involving female athletes, researchers are first encouraged to stop excluding females unless the primary endpoints are directly influenced by sex-specific mechanisms. In all investigative scenarios, researchers across the globe are encouraged to inquire and report upon more detailed information surrounding the athlete's hormonal status, including menstrual status (days since menses, length of period, duration of cycle, etc.) and/or hormonal contraceptive details and/or menopausal status.


Assuntos
Creatina , Esportes , Feminino , Humanos , Masculino , Progesterona , Atletas , Aminoácidos
4.
Biomedicines ; 10(3)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35327526

RESUMO

The immune function is closely related to iron (Fe) homeostasis and allostasis. The aim of this bioinformatics-assisted review was twofold; (i) to update the current knowledge of Fe metabolism and its relationship to the immune system, and (ii) to perform a prediction analysis of regulatory network hubs that might serve as potential biomarkers during stress-induced immunosuppression. Several literature and bioinformatics databases/repositories were utilized to review Fe metabolism and complement the molecular description of prioritized proteins. The Search Tool for the Retrieval of Interacting Genes (STRING) was used to build a protein-protein interactions network for subsequent network topology analysis. Importantly, Fe is a sensitive double-edged sword where two extremes of its nutritional status may have harmful effects on innate and adaptive immunity. We identified clearly connected important hubs that belong to two clusters: (i) presentation of peptide antigens to the immune system with the involvement of redox reactions of Fe, heme, and Fe trafficking/transport; and (ii) ubiquitination, endocytosis, and degradation processes of proteins related to Fe metabolism in immune cells (e.g., macrophages). The identified potential biomarkers were in agreement with the current experimental evidence, are included in several immunological/biomarkers databases, and/or are emerging genetic markers for different stressful conditions. Although further validation is warranted, this hybrid method (human-machine collaboration) to extract meaningful biological applications using available data in literature and bioinformatics tools should be highlighted.

5.
Nutrients ; 13(6)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199588

RESUMO

Creatine is one of the most studied and popular ergogenic aids for athletes and recreational weightlifters seeking to improve sport and exercise performance, augment exercise training adaptations, and mitigate recovery time. Studies consistently reveal that creatine supplementation exerts positive ergogenic effects on single and multiple bouts of short-duration, high-intensity exercise activities, in addition to potentiating exercise training adaptations. In this respect, supplementation consistently demonstrates the ability to enlarge the pool of intracellular creatine, leading to an amplification of the cell's ability to resynthesize adenosine triphosphate. This intracellular expansion is associated with several performance outcomes, including increases in maximal strength (low-speed strength), maximal work output, power production (high-speed strength), sprint performance, and fat-free mass. Additionally, creatine supplementation may speed up recovery time between bouts of intense exercise by mitigating muscle damage and promoting the faster recovery of lost force-production potential. Conversely, contradictory findings exist in the literature regarding the potential ergogenic benefits of creatine during intermittent and continuous endurance-type exercise, as well as in those athletic tasks where an increase in body mass may hinder enhanced performance. The purpose of this review was to summarize the existing literature surrounding the efficacy of creatine supplementation on exercise and sports performance, along with recovery factors in healthy populations.


Assuntos
Desempenho Atlético/fisiologia , Creatina/farmacologia , Suplementos Nutricionais , Exercício Físico/fisiologia , Trifosfato de Adenosina , Atletas , Bases de Dados Factuais , Humanos , Músculo Esquelético , Substâncias para Melhoria do Desempenho/farmacologia
6.
Nutrients ; 13(2)2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33572884

RESUMO

Although creatine has been mostly studied as an ergogenic aid for exercise, training, and sport, several health and potential therapeutic benefits have been reported. This is because creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised. This systematic review assesses the peer-reviewed scientific and medical evidence related to creatine's role in promoting general health as we age and how creatine supplementation has been used as a nutritional strategy to help individuals recover from injury and/or manage chronic disease. Additionally, it provides reasonable conclusions about the role of creatine on health and disease based on current scientific evidence. Based on this analysis, it can be concluded that creatine supplementation has several health and therapeutic benefits throughout the lifespan.


Assuntos
Envelhecimento/efeitos dos fármacos , Creatina/farmacocinética , Suplementos Nutricionais , Disponibilidade Biológica , Doença Crônica/reabilitação , Humanos , Ferimentos e Lesões/reabilitação
7.
Food Funct ; 9(6): 3097-3103, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29850709

RESUMO

Açaí (Euterpe oleracea Mart.) berries, characterized by high polyphenol concentrations (predominantly anthocyanins), have demonstrated anti-inflammatory and anti-diabetic activities. The study objective was to determine the modulation of lipid and glucose-metabolism, as well as oxidative stress and inflammation, by an açaí-beverage (containing 1139 mg L-1 gallic acid equivalents of total polyphenolics) in 37 individuals with metabolic syndrome (BMI 33.5 ± 6.7 kg m-2) who were randomized to consume 325 mL twice per d of a placebo control or açaí-beverage for 12 weeks. Anthropometric measurements, dietary intake, and blood and urine samples were collected at baseline and after 12 weeks of consumption. Two functional biomarkers, plasma level of interferon gamma (IFN-γ) and urinary level of 8-isoprostane, were significantly decreased after 12 weeks of açaí consumption compared to the placebo control (p = 0.0141 and 0.0099, respectively). No significant modification of biomarkers for lipid- and glucose-metabolism was observed in this study. Findings from this small pilot study provide a weak indication that the selected dose of açaí polyphenols may be beneficial in metabolic syndrome as only two biomarkers for inflammation and oxidative stress were improved over 12 weeks. Follow-up studies should be conducted with higher polyphenol-doses before drawing conclusions regarding the efficacy of açaí polyphenols in metabolic syndrome.


Assuntos
Euterpe/química , Glucose/metabolismo , Síndrome Metabólica/dietoterapia , Extratos Vegetais/metabolismo , Adolescente , Adulto , Idoso , Biomarcadores/metabolismo , Feminino , Sucos de Frutas e Vegetais/análise , Humanos , Metabolismo dos Lipídeos , Masculino , Síndrome Metabólica/imunologia , Síndrome Metabólica/metabolismo , Pessoa de Meia-Idade , Estresse Oxidativo , Projetos Piloto , Adulto Jovem
8.
J Int Soc Sports Nutr ; 14: 18, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28615996

RESUMO

Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilitation, and concussion and/or spinal cord neuroprotection. Additionally, a number of clinical applications of creatine supplementation have been studied involving neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's, Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, brain and heart ischemia, adolescent depression, and pregnancy. These studies provide a large body of evidence that creatine can not only improve exercise performance, but can play a role in preventing and/or reducing the severity of injury, enhancing rehabilitation from injuries, and helping athletes tolerate heavy training loads. Additionally, researchers have identified a number of potentially beneficial clinical uses of creatine supplementation. These studies show that short and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. Moreover, significant health benefits may be provided by ensuring habitual low dietary creatine ingestion (e.g., 3 g/day) throughout the lifespan. The purpose of this review is to provide an update to the current literature regarding the role and safety of creatine supplementation in exercise, sport, and medicine and to update the position stand of International Society of Sports Nutrition (ISSN).


Assuntos
Creatina/administração & dosagem , Suplementos Nutricionais , Exercício Físico/fisiologia , Ciências da Nutrição e do Esporte/normas , Traumatismos em Atletas/prevenção & controle , Desempenho Atlético , Humanos , Substâncias para Melhoria do Desempenho/administração & dosagem , Sociedades Científicas
9.
J Int Soc Sports Nutr ; 11(1): 55, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25505854

RESUMO

BACKGROUND: The purpose of this study was to examine the short-term and chronic effects of ß-ALA supplementation with and without creatine monohydrate on body composition, aerobic and anaerobic exercise performance, and muscle carnosine and creatine levels in college-aged recreationally active females. METHODS: Thirty-two females were randomized in a double-blind, placebo-controlled manner into one of four supplementation groups: ß-ALA only (BA, n = 8), creatine only (CRE, n = 8), ß-ALA and creatine combined (BAC, n = 9) and placebo (PLA, n = 7). Participants supplemented for four weeks included a loading phase for the creatine for week 1 of 0.3 g/kg of body weight and a maintenance phase for weeks 2-4 of 0.1 g/kg of body weight, with or without a continuous dose of ß-ALA of 0.1 g/kg of body weight with doses rounded to the nearest 800 mg capsule providing an average of 6.1 ± 0.7 g/day of ß-ALA. Participants reported for testing at baseline, day 7 and day 28. Testing sessions consisted of obtaining a resting muscle biopsy of the vastus lateralis, body composition measurements, performing a graded exercise test on the cycle ergometer for VO2peak with lactate threshold determination, and multiple Wingate anaerobic capacity tests. RESULTS: Although mean changes were consistent with prior studies and large effect sizes were noted, no significant differences were observed among groups in changes in muscle carnosine levels (BA 35.3 ± 45; BAC 42.5 ± 99; CRE 0.72 ± 27; PLA 13.9 ± 44%, p = 0.59). Similarly, although changes in muscle phosphagen levels after one week of supplementation were consistent with prior reports and large effect sizes were seen, no statistically significant effects were observed among groups in changes in muscle phosphagen levels and the impact of CRE supplementation appeared to diminish during the maintenance phase. Additionally, significant time × group × Wingate interactions were observed among groups for repeated sprint peak power normalized to bodyweight (p = 0.02) and rate of fatigue (p = 0.04). CONCLUSIONS: Results of the present study did not reveal any consistent additive benefits of BA and CRE supplementation in recreationally active women.

10.
Eur J Appl Physiol ; 114(6): 1321-32, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24633488

RESUMO

PURPOSE: The present study evaluated the effects of creatine monohydrate (CrM) consumption post-exercise on body composition and muscle strength in middle to older males following a 12-week resistance training program. METHODS: In a double-blind, randomized trial, 20 males aged between 55 and 70 years were randomly assigned to consume either CrM-carbohydrate (CHO) [20 g days(-1) CrM + 5 g days(-1) CHO × 7 days, then 0.1 g kg(-1) CrM + 5 g CHO on training days (average dosage of ~8.8 g)] or placebo CHO (20 g days(-1) CHO × 7 days, then 5 g CHO on training days) while participating in a high intensity resistance training program [3 sets × 10 repetitions at 75% of 1 repetition maximum (1RM)], 3 days weeks(-1) for 12 weeks. Following the initial 7-day "loading" phase, participants were instructed to ingest their supplement within 60 min post-exercise. Body composition and muscle strength measurements, blood collection and vastus lateralis muscle biopsy were completed at 0, 4, 8 and 12 weeks of the supplement and resistance training program. RESULTS: A significant time effect was observed for 1RM bench press (p = 0.016), leg press (p = 0.012), body mass (p = 0.03), fat-free mass (p = 0.005) and total myofibrillar protein (p = 0.005). A trend for larger muscle fiber cross-sectional area in the type II fibers compared to type I fibers was observed following the 12-week resistance training (p = 0.08). No supplement interaction effects were observed. CONCLUSION: Post-exercise ingestion of creatine monohydrate does not provide greater enhancement of body composition and muscle strength compared to resistance training alone in middle to older males.


Assuntos
Creatina/farmacologia , Força Muscular/efeitos dos fármacos , Músculo Esquelético/fisiologia , Treinamento Resistido , Adaptação Fisiológica , Idoso , Creatina/administração & dosagem , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/crescimento & desenvolvimento
11.
Nutr Res ; 34(3): 191-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24655485

RESUMO

The effects of a single bout of resistance exercise (RE) in conjunction with periexercise branched-chain amino acid (BCAA) and carbohydrate (CHO) ingestion on skeletal muscle signaling markers indicative of muscle protein synthesis were determined. It was hypothesized that CHO + BCAA would elicit a more profound effect on these signaling markers compared with CHO. Twenty-seven males were randomly assigned to CHO, CHO + BCAA, or placebo (PLC) groups. Four sets of leg presses and leg extensions were performed at 80% 1 repetition maximum. Supplements were ingested 30 minutes and immediately before and after RE. Venous blood and muscle biopsy samples were obtained immediately before supplement ingestion and 0.5, 2, and 6 hours after RE. Serum insulin and glucose and phosphorylated levels of muscle insulin receptor substrate 1 (IRS-1), protein kinase B, mammalian target of rapamycin, phosphorylated 70S6 kinase, and 4E binding protein 1 were assessed. Data were analyzed by 2-way repeated-measures analysis of variance. Significant group × time interactions were observed for glucose and insulin (P < .05) showing that CHO and CHO + BCAA were significantly greater than PLC. Significant time main effects were observed for IRS-1 (P = .001), protein kinase B (P = .031), mammalian target of rapamycin (P = .003), and phosphorylated 70S6 kinase (P = .001). Carbohydrate and CHO + BCAA supplementation significantly increased IRS-1 compared with PLC (P = .002). However, periexercise coingestion of CHO and BCAA did not augment RE-induced increases in skeletal muscle signaling markers indicative of muscle protein synthesis when compared with CHO.


Assuntos
Aminoácidos de Cadeia Ramificada/administração & dosagem , Carboidratos da Dieta/administração & dosagem , Proteínas Musculares/biossíntese , Treinamento Resistido , Transdução de Sinais/efeitos dos fármacos , Sirolimo/metabolismo , Adulto , Glicemia/metabolismo , Índice de Massa Corporal , Proteínas Alimentares/administração & dosagem , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Insulina/sangue , Proteínas Substratos do Receptor de Insulina/metabolismo , Masculino , Músculo Esquelético/efeitos dos fármacos , Fosfatidilinositol 3-Quinase/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Adulto Jovem
12.
Food Chem Toxicol ; 61: 47-52, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23376779

RESUMO

PURPOSE: The impact of prophylactic supplementation of N-acetyl-cysteine (NAC) and epigallocatechin gallate (EGCG) on intramuscular expression of proteolytic genes after unaccustomed eccentric muscle contractions was investigated. METHODS: Thirty apparently healthy males (mean ± SD: 20.0 ± 1.8 years, 175 ± 7.1cm, 76.1 ± 16.9 kg) ingested daily either 1,800 mg of NAC or 1,800 mg of EGCG (98% total polyphenols, 80% total catechins, and 50% EGCG), or 1,000 mg of a glucomannan placebo (PLA) in a double blind, prophylactic fashion for 14 days. Subjects then completed an unaccustomed eccentric exercise bout (100 repetitions at 30 °s(-1)) using the dominant knee extensors. Skeletal muscle biopsies were collected from the vastus lateralis at baseline and both 6 and 24h after exercise. The expression of proteolytic genes [i.e., muscle ring-finger 1 (MuRF1), atrogin-1, α-type 20S subunit C2 (HC2), α-type 20S subunit C3 (HC3), ubiquitin protein ligase 3B (UBE3B), µ-calpain, and m-calpain] was quantified using real-time RT-PCR. Separate 3 × 3 (group × time) repeated measures ANOVAs were used to analyze changes in gene expression over time between groups. RESULTS: No significant group × time interactions were detected between groups for the expression of any of the atrogenes or calpains (p>0.05). Significant main effects for time identified increases in MuRF1 (6h: 5.3 ± 10.8 fold; p=0.046), UBE3B (6h: 5.3 ± 7.7 fold; p=0.006; 24h: 3.3 ± 4.5 fold; p=0.005), and m-calpain expression (6h: 2.7 ± 4.4 fold; p=0.045) in all participants following exercise. Increases approached significance in HC2 (6h: 1.9 ± 2.4 fold; p=0.079; 24h: 1.6 ± 1.9 fold; p=0.084) and m-calpain expression (24h: 1.8 ± 2.3 fold; p=0.084) following exercise. CONCLUSIONS: Prophylactic supplementation of NAC and EGCG did not impact acute changes in skeletal muscle proteolytic gene expression following eccentric exercise. Eccentric muscle contractions elevated MuRF1 and UBE3B, while m-calpain and HC2 mRNA tended to increase.


Assuntos
Acetilcisteína/farmacologia , Catequina/análogos & derivados , Expressão Gênica/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Calpaína/genética , Catequina/farmacologia , Suplementos Nutricionais , Método Duplo-Cego , Exercício Físico , Humanos , Masculino , Contração Muscular/efeitos dos fármacos , Contração Muscular/genética , Proteínas Musculares/genética , Músculo Esquelético/fisiologia , Experimentação Humana não Terapêutica , Proteínas Ligases SKP Culina F-Box/genética , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases/genética , Adulto Jovem
13.
Nutr J ; 10: 99, 2011 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-21943352

RESUMO

BACKGROUND: Milk protein fractions and peptides have been shown to have bioactive properties. This preliminary study examined the potential mechanisms of action and clinical safety of novel milk protein peptide (MP). FINDINGS: A novel MP mixture inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor 2 (VEGFR2), and insulin receptor (IR) with IC50 of 9.85 µM, 7.7 µM, and 6.18 µM respectively. In vitro, this multi-kinase inhibitor causes apoptosis in HT-29 colon cancer cells, and in a C. elegans worm study, showed a weak but significant increase in lifespan. A six week double-blind, placebo-controlled study involving 73 healthy volunteers demonstrated that the MP mixture is safe to consume orally. All clinical blood markers remained within normal levels and no clinically significant side effects were reported. There was some evidence of improved insulin sensitivity, neutrophil-to-lymphocyte ratio (NLR), and quality of life assessment of role of physical function. CONCLUSIONS: These data in combination with the observed in vitro anti-cancer properties warrant further clinical studies to investigate this MP mixture as a potential clinical nutrition intervention for improving the quality of life and clinical outcomes in cancer patients. TRIAL REGISTRATION: NCT01412658.


Assuntos
Proteínas do Leite/farmacologia , Proteínas do Leite/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Adulto , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/crescimento & desenvolvimento , Bovinos , Método Duplo-Cego , Receptores ErbB/antagonistas & inibidores , Feminino , Células HT29/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Masculino , Pessoa de Meia-Idade , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptor de Insulina/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores
14.
Int J Sport Nutr Exerc Metab ; 20(6): 457-65, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21116018

RESUMO

The purpose of this study was to determine the effects of an alleged aromatase and 5-α reductase inhibitor (AI) on strength, body composition, and hormonal profiles in resistance-trained men. Thirty resistance-trained men were randomly assigned in a double-blind manner to ingest 500 mg of either a placebo (PL) or AI once per day for 8 wk. Participants participated in a 4-d/wk resistance-training program for 8 wk. At Weeks 0, 4, and 8, body composition, 1-repetition-maximum (1RM) bench press and leg press, muscle endurance, anaerobic power, and hormonal profiles were assessed. Statistical analyses used a 2-way ANOVA with repeated measures for all criterion variables (p ≤ .05). Significant Group × Time interaction effects occurred over the 8-wk period for percent body fat (AI: -1.77% ± 1.52%, PL: -0.55% ± 1.72%; p = .048), total testosterone (AI: 0.97 ± 2.67 ng/ml, PL: -2.10 ± 3.75 ng/ml; p = .018), and bioavailable testosterone (AI: 1.32 ± 3.45 ng/ml, PL: -1.69 ± 3.94 ng/ml; p = .049). Significant main effects for time (p ≤ .05) were noted for bench- and leg-press 1RM, lean body mass, and estradiol. No significant changes were detected among groups for Wingate peak or mean power, total body weight, dihydrotestosterone, hemodynamic variables, or clinical safety data (p > .05). The authors concluded that 500 mg of dailyAI supplementation significantly affected percent body fat, total testosterone, and bioavailable testosterone compared with a placebo in a double-blind fashion.


Assuntos
Inibidores de 5-alfa Redutase/farmacologia , Inibidores da Aromatase/farmacologia , Di-Hidrotestosterona/sangue , Estradiol/sangue , Testosterona/sangue , Trigonella , Inibidores de 5-alfa Redutase/sangue , Tecido Adiposo/efeitos dos fármacos , Adulto , Análise de Variância , Inibidores da Aromatase/sangue , Composição Corporal/efeitos dos fármacos , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Masculino , Músculo Esquelético/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Treinamento Resistido , Fatores de Tempo , Adulto Jovem
15.
Amino Acids ; 39(1): 219-32, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19967420

RESUMO

Prophylactic supplementation of N-acetyl-cysteine (NAC) and epigallocatechin gallate (EGCG) was studied for physiological and cellular changes in skeletal muscle after eccentric muscle contractions. Thirty healthy, active males (20.0 +/- 1.8 years, 160 +/- 7.1 cm, 76.1 +/- 17.0 kg) ingested for 14 days either 1,800 mg of NAC, 1,800 mg of EGCG, or 1,000 mg of fiber (glucomannan) placebo (PLC) in a double blind, prophylactic fashion. Subjects completed one eccentric exercise bout (100 repetitions at 30 degrees /s) using the dominant knee extensors. Strength and soreness were assessed, and blood and muscle samples obtained before and 6, 24, 48, and 72 h with no muscle sample being collected at 72 h. Separate mixed factorial repeated measures ANOVA (P < 0.05) were used for all statistical analysis. All groups experienced significantly reduced peak torque production after 6 and 24 h, increased soreness at all time points from baseline [with even greater soreness levels 24 h after exercise in PLC when compared to EGCG and NAC (P < 0.05)], increased lactate dehydrogenase at 6 h, and increased creatine kinase 6, 24 and 48 h after exercise. No significant group x time interaction effects were found for serum cortisol, neutrophil counts, and the neutrophil:lymphocyte ratio; although, all values experienced significant changes 6 h after exercise (P < 0.05), but at no other time points. At 48 h after the exercise bout the Neu:Lym ratio in EGCG was significantly less than NAC (P < 0.05), whereas there was a trend (P = 0.08) for the EGCG values to be less when compared to PLC at this time point. Markers of intramuscular mitochondrial and cytosolic apoptosis were assessed (e.g., bax, bcl-2, cytochrome C, caspase-3 content/enzyme activity, and total DNA content). Significant increases (P < 0.05) in muscle levels of bax and bcl-2 were observed in all groups with no significant differences between groups, whereas no changes (P > 0.05) were reported for cytochrome C, caspase-3 content, caspase-3 enzyme activity, and total DNA. Caspase-3 enzyme activity was significantly greater in all groups 48 h after exercise when compared to baseline (P < 0.05) and 6 h (P < 0.05) after exercise. An eccentric bout of muscle contractions appears to significantly increase muscle damage, markers of mitochondrial apoptosis, apoptotic enzyme activity, and whole-blood cell markers of inflammation with no changes in oxidative stress. While soreness ratings were blunted in the two supplementation groups 24 h after exercise when compared to PLC values, more research is needed to determine the potential impact of EGCG and NAC supplementation on changes related to oxidative stress, apoptosis, and eccentric exercise.


Assuntos
Acetilcisteína/administração & dosagem , Adaptação Fisiológica , Antioxidantes/administração & dosagem , Catequina/análogos & derivados , Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Adulto , Catequina/administração & dosagem , Suplementos Nutricionais , Método Duplo-Cego , Teste de Esforço , Humanos , Masculino , Contração Muscular/fisiologia , Adulto Jovem
16.
J Strength Cond Res ; 23(8): 2179-87, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19826309

RESUMO

A single bout of high-intensity resistance exercise is capable of activating the expression of various genes in skeletal muscle involved in hypertrophy such as myosin heavy chain (MHC) isoforms, myogenic regulatory factors (MRFs), and growth factors. However, the specific role exercise intensity plays on the expression of these genes is not well defined. The purpose of this study was to investigate the effects of exercise intensity on MHC (type I, IIA, IIX), MRF (Myo-D, myogenin, MRF-4, myf5), and growth factor (insulin-like growth factor [IGF]-1, IGF-1 receptor [IGF-R1], mechano-growth factor [MGF]) mRNA expression. Thirteen male participants (21.5 +/- 2.9 years, 86.1 +/- 19.5 kg, 69.7 +/- 2.7 in.) completed bouts of resistance exercise involving 4 sets of 18-20 repetitions with 60-65% 1 repetition maximum (1RM) and 4 sets of 8-10 repetitions with 80-85% 1RM. Vastus lateralis biopsies were obtained immediately before exercise, and at 30 minutes, 2 hours, and 6 hours after each bout. The levels of mRNA expression were determined using real-time polymerase chain reaction. Data were analyzed using 2 x 4 multivariate analysis of variance (p

Assuntos
Biomarcadores/metabolismo , Desenvolvimento Muscular/fisiologia , Músculo Esquelético/metabolismo , RNA Mensageiro/metabolismo , Treinamento Resistido/métodos , Análise de Variância , Biópsia , Estudos Cross-Over , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Desenvolvimento Muscular/genética , Fatores de Regulação Miogênica/genética , Fatores de Regulação Miogênica/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Miostatina/genética , Miostatina/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Regulação para Cima , Adulto Jovem
17.
J Int Soc Sports Nutr ; 5: 8, 2008 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-18318910

RESUMO

BACKGROUND: To determine whether acute (single dose) and/or chronic (14-days) supplementation of CoQ10 will improve anaerobic and/or aerobic exercise performance by increasing plasma and muscle CoQ10 concentrations within trained and untrained individuals. METHODS: Twenty-two aerobically trained and nineteen untrained male and female subjects (26.1 +/- 7.6 yrs, 172 +/- 8.7 cm, 73.5 +/- 17 kg, and 21.2 +/- 7.0%) were randomized to ingest in a double-blind manner either 100 mg of a dextrose placebo (CON) or a fast-melt CoQ10 supplement (CoQ10) twice a day for 14-days. On the first day of supplementation, subjects donated fasting blood samples and a muscle biopsy. Subjects were then given 200 mg of the placebo or the CoQ10 supplement. Sixty minutes following supplement ingestion, subjects completed an isokinetic knee extension endurance test, a 30-second wingate anaerobic capacity test, and a maximal cardiopulmonary graded exercise test interspersed with 30-minutes of recovery. Additional blood samples were taken immediately following each exercise test and a second muscle biopsy sample was taken following the final exercise test. Subjects consumed twice daily (morning and night), 100 mg of either supplement for a period of 14-days, and then returned to the lab to complete the same battery of tests. Data was analyzed using repeated measures ANOVA with an alpha of 0.05. RESULTS: Plasma CoQ10 levels were significantly increased following 2 weeks of CoQ10 supplementation (p < 0.001); while a trend for higher muscle CoQ10 levels was observed after acute CoQ10 ingestion (p = 0.098). A trend for lower serum superoxide dismutase (SOD) was observed following acute supplementation with CoQ10 (p = 0.06), whereas serum malondialdehyde (MDA) tended to be significantly higher (p < 0.05). Following acute ingestion of CoQ10, plasma CoQ10 levels were significantly correlated to muscle CoQ10 levels; maximal oxygen consumption; and treadmill time to exhaustion. A trend for increased time to exhaustion was observed following 2 weeks of CoQ10 supplementation (p = 0.06). CONCLUSION: Acute supplementation with CoQ10 resulted in higher muscle CoQ10 concentration, lower serum SOD oxidative stress, and higher MDA levels during and following exercise. Chronic CoQ10 supplementation increased plasma CoQ10 concentrations and tended to increase time to exhaustion. Results indicate that acute and chronic supplementation of CoQ10 may affect acute and/or chronic responses to various types of exercise.

18.
J Strength Cond Res ; 16(3): 325-34, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12173945

RESUMO

Conjugated linoleic acids (CLA) are essential fatty acids that have been reported in animal studies to decrease catabolism, promote fat loss, increase bone density, enhance immunity, and serve as an antiatherogenic and anticarcinogenic agent. For this reason, CLA has been marketed as a supplement to promote weight loss and general health. CLA has also been heavily marketed to resistance-trained athletes as a supplement that may help lessen catabolism, decrease body fat, and promote greater gains in strength and muscle mass during training. Although basic research is promising, few studies have examined whether CLA supplementation during training enhances training adaptations and/or affects markers of health. This study evaluated whether CLA supplementation during resistance training affects body composition, strength, and/or general markers of catabolism and immunity. In a double-blind and randomized manner, 23 experienced, resistance-trained subjects were matched according to body mass and training volume and randomly assigned to supplement their diet with 9 g;pdd(-1) of an olive oil placebo or 6 g;pdd(-1) of CLA with 3 g;pdd(-1) of fatty acids for 28 days. Prior to and following supplementation, fasting blood samples, total body mass, and dual-energy X-ray absorptiometry (DEXA) determined body composition, and isotonic bench press and leg press 1 repetition maximums (1RMs) were determined. Results revealed that although some statistical trends were observed with moderate to large effect sizes, CLA supplementation did not significantly affect (p > 0.05) changes in total body mass, fat-free mass, fat mass, percent body fat, bone mass, strength, serum substrates, or general markers of catabolism and immunity during training. These findings indicate that CLA does not appear to possess significant ergogenic value for experienced resistance-trained athletes.


Assuntos
Análise Química do Sangue , Composição Corporal/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Suplementos Nutricionais , Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Ácido alfa-Linolênico/farmacologia , Absorciometria de Fóton , Adulto , Contagem de Células Sanguíneas , Método Duplo-Cego , Humanos , Masculino , Contração Muscular , Aptidão Física , Levantamento de Peso , Ácido alfa-Linolênico/efeitos adversos
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