RESUMO
Polyphenols are secondary metabolites involved in a myriad of critical processes in plants. Over recent decades, special attention has been paid to the anti-oxidative role of fruit-derived polyphenols in the human diet, with evidence supporting the contribution of polyphenols in the prevention of numerous non-communicable disease outcomes. However, due to the low concentration in biological fluids in vivo, the antioxidant properties of polyphenols seem to be related to an enhanced endogenous antioxidant capacity induced via signaling through the nuclear respiratory factor 2 pathway. Polyphenols also seem to possess anti-inflammatory and antioxidant properties and have been shown to enhance vascular function via nitric oxide mediated mechanisms. Consequently, there is rationale to support fruit-derived polyphenol supplementation to enhance exercise performance, possibly via improved muscle perfusion. Fruit-derived polyphenol supplementation in exercise studies have included a variety of fruits, e.g., New Zealand blackcurrant, pomegranate, and cherry, in the form of extracts (multicomponent or purified), juices and infusions to varying degrees of benefit. For example, research has yet to link the health-related benefits of black elderberry (Sambucus nigra L.) ingestion to exercise performance in spite of the purported health benefits associated with black elderberry provision in vitro and in vivo models, which has been attributed to their high antioxidant capacity and polyphenol content. This review summarizes the existing evidence supporting a beneficial effect of fruit-derived polyphenols on various biological processes and outlines the potential for black elderberry ingestion to improve nitric oxide production, exercise performance, and the associated physiological responses before-, during- and post-exercise.
Assuntos
Suplementos Nutricionais , Exercício Físico/fisiologia , Frutas/química , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/uso terapêutico , Extratos Vegetais/uso terapêutico , Polifenóis/uso terapêutico , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/uso terapêutico , Antioxidantes/isolamento & purificação , Antioxidantes/uso terapêutico , Suplementos Nutricionais/efeitos adversos , Nível de Saúde , Humanos , Músculo Esquelético/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/efeitos adversos , Substâncias para Melhoria do Desempenho/isolamento & purificação , Extratos Vegetais/efeitos adversos , Extratos Vegetais/isolamento & purificação , Polifenóis/efeitos adversos , Polifenóis/isolamento & purificaçãoRESUMO
The objective of this study was to establish a novel method for rapid detection of six glucocorticoids (prednisone, prednisone acetate, prednisolone, hydrocortisone, hydrocortisone acetate, and dexamethasone) added illegally in dietary supplements simultaneously by combining thin layer chromatography (TLC) with spot-concentrated Raman scattering (SCRS). The doping ingredients were separated by TLC, and viewed and located with UV light (254 nm), enriched by chromatography, then Raman spectra were directly detected by a Raman Imagine microscope with 780 nm laser source. This method had complementary advantages of TLC and Raman spectroscopy, which enhanced the specificity of the test results. The limit of detection (LOD) of the reference substances were 4 µg, 4 µg, 4 µg, 6 µg, 6 µg, and 4 µg, respectively. The method was used to study the six glucocorticoids added illegally in five dietary supplements. Fake drugs had been detected. The study showed that the TLC-SCRS method is simple, rapid, specific, sensitive, and reliable. The method could be used for effective separation and detection of six chemical components used in dietary supplement products, and would have good prospects for on-site qualitative screening of dietary supplement products for adulterants.
Assuntos
Dexametasona/isolamento & purificação , Suplementos Nutricionais/análise , Hidrocortisona/análogos & derivados , Hidrocortisona/isolamento & purificação , Substâncias para Melhoria do Desempenho/isolamento & purificação , Prednisolona/isolamento & purificação , Prednisona/isolamento & purificação , Cromatografia em Camada Fina/métodos , Dopagem Esportivo/prevenção & controle , Humanos , Limite de Detecção , Análise Espectral Raman/métodosRESUMO
The challenges facing modern anti-doping analytical science are increasingly complex given the expansion of target drug substances, as the pharmaceutical industry introduces more novel therapeutic compounds and the internet offers designer drugs to improve performance. The technical challenges are manifold, including, for example, the need for advanced instrumentation for greater speed of analyses and increased sensitivity, specific techniques capable of distinguishing between endogenous and exogenous metabolites, or biological assays for the detection of peptide hormones or their markers, all of which require an important investment from the laboratories and recruitment of highly specialized scientific personnel. The consequences of introducing sophisticated and complex analytical procedures may result in the future in a change in the strategy applied by the Word Anti-Doping Agency in relation to the introduction and performance of new techniques by the network of accredited anti-doping laboratories.
Assuntos
Drogas Desenhadas/isolamento & purificação , Dopagem Esportivo/prevenção & controle , Substâncias para Melhoria do Desempenho/isolamento & purificação , Detecção do Abuso de Substâncias/métodos , Detecção do Abuso de Substâncias/tendências , Acreditação , Anabolizantes/isolamento & purificação , Humanos , Cooperação Internacional , Laboratórios/normas , Hormônios Peptídicos/isolamento & purificaçãoRESUMO
PURPOSE: Myostatin is a key regulator of skeletal muscle growth and inhibition of its signaling pathway results in an increased muscle mass and function. The aim of this study was to develop a qualitative detection assay for myostatin-neutralizing antibodies for doping control purposes by using immunological approaches. EXPERIMENTAL DESIGN: To detect different types of myostatin-neutralizing antibodies irrespective of their amino acid sequence, an immunological assay specific for antibodies directed against myostatin and having a human Fc domain was established. Affinity purification and Western blotting strategies were combined to allow extracting and identifying relevant analytes from 200 µL of plasma/serum in a non-targeted approach. The assay was characterized regarding specificity, linearity, precision, robustness, and recovery. RESULTS: The assay was found to be highly specific, robust, and linear from 0.1 to 1 µg/mL. The precision was successfully specified at three different concentrations and the recovery of the affinity purification was 58%. CONCLUSIONS AND CLINICAL RELEVANCE: Within this study, an immunological detection assay for myostatin-neutralizing antibodies present in plasma/serum specimens was developed and successfully characterized. The presented approach can easily be modified to include other therapeutic antibodies and serves as proof-of-concept for the detection of antibody-based myostatin inhibitors in doping control samples.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/isolamento & purificação , Western Blotting , Dopagem Esportivo , Miostatina/antagonistas & inibidores , Miostatina/imunologia , Substâncias para Melhoria do Desempenho/sangue , Substâncias para Melhoria do Desempenho/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Cromatografia de Afinidade , Humanos , Substâncias para Melhoria do Desempenho/imunologiaRESUMO
UNLABELLED: The purpose of the study was to determine the effect of ginseng-based steroid Rg1 on TNF-alpha and IL-10 gene expression in human skeletal muscle against exercise challenge, as well as on its ergogenic outcomes. Randomized double-blind placebo-controlled crossover trials were performed, separated by a 4-week washout. Healthy young men were randomized into two groups and received capsule containing either 5 mg of Rg1 or Placebo one night and one hour before exercise. Muscle biopsies were conducted at baseline, immediately and 3 h after a standardized 60-min cycle ergometer exercise. While treatment differences in glycogen depletion rate of biopsied quadriceps muscle during exercise did not reach statistical significance, Rg1 supplementations enhanced post-exercise glycogen replenishment and increased citrate synthase activity in the skeletal muscle 3 h after exercise, concurrent with improved meal tolerance during recovery (P<0.05). Rg1 suppressed the exercise-induced increases in thiobarbituric acids reactive substance (TBARS) and reversed the increased TNF-alpha and decreased IL-10 mRNA of quadriceps muscle against the exercise challenge. PGC-1 alpha and GLUT4 mRNAs of exercised muscle were not affected by Rg1. Maximal aerobic capacity (VO2max) was not changed by Rg1. However, cycling time to exhaustion at 80% VO2max increased significantly by ~20% (P<0.05). CONCLUSION: Our result suggests that Rg1 is an ergogenic component of ginseng, which can minimize unwanted lipid peroxidation of exercised human skeletal muscle, and attenuate pro-inflammatory shift under exercise challenge.
Assuntos
Suplementos Nutricionais , Exercício Físico , Ginsenosídeos/farmacologia , Músculo Esquelético/efeitos dos fármacos , Panax/química , Substâncias para Melhoria do Desempenho/farmacologia , Adulto , Método Duplo-Cego , Ginsenosídeos/química , Ginsenosídeos/isolamento & purificação , Transportador de Glucose Tipo 4/metabolismo , Glicogênio/metabolismo , Humanos , Interleucina-10/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Músculo Esquelético/metabolismo , Substâncias para Melhoria do Desempenho/química , Substâncias para Melhoria do Desempenho/isolamento & purificação , Resistência Física/efeitos dos fármacos , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The present review of the literature is focused on the problem of forensic-medical diagnostics of doping cases in sports, with special reference to the main classes of pharmaceutical products forbidden for use by the International Olympic Committee. The main causes of death among the athletes as a result of using doping substances are considered. Much attention is given to adverse reactions induced by long-time intake of anabolic steroids many of which can be identified at autopsy.
Assuntos
Anabolizantes/intoxicação , Dopagem Esportivo , Toxicologia Forense/métodos , Substâncias para Melhoria do Desempenho/intoxicação , Esteroides/intoxicação , Anabolizantes/isolamento & purificação , Dopagem Esportivo/legislação & jurisprudência , Toxicologia Forense/legislação & jurisprudência , Humanos , Substâncias para Melhoria do Desempenho/isolamento & purificação , Intoxicação/diagnóstico , Intoxicação/mortalidade , Esteroides/isolamento & purificaçãoRESUMO
For most peptide hormones prohibited in elite sports the concentrations in plasma or urine are very low (pg/mL). Accordingly, hyphenated purification and enrichment steps prior to mass spectrometric detection are required to obtain sufficient doping control assays. Immunoaffinity purification in combination with nano-scale liquid chromatography coupled to high resolution/high accuracy mass spectrometry was found to have the potential of providing the necessary sensitivity and unambiguous specificity to produce reliable results. With the presented methodology 12 prohibited peptides (porcine insulin, Novolog, Apidra, Lantus DesB30-32 metabolite, Humalog and human insulin, Synacthen (synthetic ACTH analogue), luteinizing hormone-releasing hormone (LH-RH), growth hormone releasing hormone (GH-RH(1-29)) and CJC-1295 (GH-RH analogue), LongR(3)-IGF-1 and IFG-1) were simultaneously purified from plasma/serum or urine. With limits of detection for each target compound ranging in the low pg/mL level (urine), the method enables the determination of urinary peptides at physiologically relevant concentrations. For each class of peptides an appropriate antibody and a respective internal standard was implemented ensuring robust analysis conditions. Due to the fast and simple sample preparation procedure (â¼25 samples per day) and the fact that all materials are commercial available, the implementation of the methodology to laboratories from other analytical fields (forensics, pharmacokinetic sciences, etc.) is enabled.
Assuntos
Cromatografia de Afinidade/métodos , Imunoensaio/métodos , Hormônios Peptídicos/isolamento & purificação , Detecção do Abuso de Substâncias/métodos , Sequência de Aminoácidos , Cromatografia de Afinidade/normas , Dopagem Esportivo , Hormônio Liberador de Hormônio do Crescimento/análogos & derivados , Hormônio Liberador de Hormônio do Crescimento/sangue , Hormônio Liberador de Hormônio do Crescimento/isolamento & purificação , Hormônio Liberador de Hormônio do Crescimento/urina , Humanos , Imunoensaio/normas , Insulina Aspart/sangue , Insulina Aspart/urina , Espectrometria de Massas/métodos , Espectrometria de Massas/normas , Dados de Sequência Molecular , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/isolamento & purificação , Fragmentos de Peptídeos/urina , Hormônios Peptídicos/sangue , Hormônios Peptídicos/urina , Substâncias para Melhoria do Desempenho/sangue , Substâncias para Melhoria do Desempenho/isolamento & purificação , Substâncias para Melhoria do Desempenho/urina , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores de TempoRESUMO
The sensitivity of the athlete blood passport to detect blood doping may be improved by the inclusion of total hemoglobin mass (Hb(mass)), but the comparability of Hb(mass) from different laboratories is unknown. To optimize detection sensitivity, the analytical variability associated with Hb(mass) measurement must be minimized. The aim of this study was to investigate the efficacy of using quality controls to minimize the variation in Hb(mass) between laboratories. Three simulated laboratories were set up in one location. Nine participants completed three carbon monoxide (CO) re-breathing tests in each laboratory. One participant completed two CO re-breathing tests in each laboratory. Simultaneously, quality controls containing Low (1-3%) and High (8-11%) concentrations of percent carboxyhemoglobin (%HbCO) were measured to compare hemoximeters in each laboratory. Linear mixed modeling was used to estimate the within-subject variation in Hb(mass), expressed as the coefficient of variation, and to estimate the effect of different laboratories. The analytic variation of Hb(mass) was 2.4% when tests were conducted in different laboratories, which reduced to 1.6% when the model accounted for between-laboratory differences. Adjustment of Hb(mass) values using quality controls achieved a comparable analytic variation of 1.7%. The majority of between-laboratory variation in Hb(mass) originated from the difference between hemoximeters, which could be eliminated using appropriate quality controls.
Assuntos
Hemoglobinas/análise , Substâncias para Melhoria do Desempenho/isolamento & purificação , Controle de Qualidade , Detecção do Abuso de Substâncias/normas , Adulto , Território da Capital Australiana , Dopagem Esportivo , Feminino , Humanos , Laboratórios/normas , Masculino , Detecção do Abuso de Substâncias/métodos , Adulto JovemRESUMO
Several peptide drugs are being manufactured illicitly, and in some cases they are being made available to the public before entering or completing clinical trials. At the request of Norwegian police and customs authorities, unknown pharmaceutical preparations suspected to contain peptide drugs are regularly subjected to analysis. In 2009, an unknown pharmaceutical preparation was submitted for analysis by liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS). The preparation was found to contain a 29 amino acid peptide with a C-terminal amide function. Based on the interpretation of mass spectrometric data, an amino acid sequence was proposed. The sequence is consistent with a peptide currently marketed under the name CJC-1295. CJC-1295 is a releasing factor for growth hormone and is therefore considered a Prohibited Substance under Section S2 of the WADA Prohibited List. This substance has potential performance-enhancing effects, it is readily available, and there is reason to believe that it is being used within the bodybuilding community.