title: The benefit of a supplement with the antioxidant melatonin on redox status and muscle damage in resistance-trained athletes.
abstract: Previous data showed that the administration of high doses of melatonin improved the circadian system in athletes. Here, we investigated in the same experimental paradigm whether the antioxidant properties of melatonin has also beneficial effects against exercise-induced oxidative stress and muscle damage in athletes. Twenty-four athletes were treated with 100 mg·day-1of melatonin or placebo 30 min before bedtime during 4 weeks in a randomized double-blind scheme. Exercise intensity was higher during the study that before starting it. Blood samples were collected before and after treatment, and plasma was used for oxygen radical absorption capacity (ORAC), lipid peroxidation (LPO), nitrite plus nitrate (NOx), and advanced oxidation protein products (AOPP) determinations. Glutathione (GSH), glutathione disulphide (GSSG) levels, and glutathione peroxidase (GPx) and reductase (GRd) activities, were measured in erythrocytes. Melatonin intake increased ORAC, reduced LPO and NOx levels, and prevented the increase of AOPP, compared to placebo group. Melatonin was also more efficient than placebo in reducing GSSG·GSH-1and GPx·GRd-1ratios. Melatonin, but not placebo, reduced creatine kinase, lactate dehydrogenase, creatinine, and total cholesterol levels. Overall, the data reflect a beneficial effect of melatonin treatment in resistance-training athletes, preventing extra- and intracellular oxidative stress induced by exercise, and yielding further skeletal muscle protection against exercise-induced oxidative damage.
authors.affiliation: a Instituto de Biotecnología, Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada, 18016-Granada, Spain.|b Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016-Granada, Spain.|c Department of Nutrition, Atlântica University Higher Institution, Lisbon, Portugal.
authors.forename: Roberto C
authors.initials: RC
authors.lastname: Leonardo-Mendonça
authors.affiliation: d Departamento de Educación Física y Deportiva, Facultad de Ciencias del Deporte, Universidad de Granada, 18071-Granada, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Ocaña-Wilhelmi
authors.affiliation: e Unidad de Gestión Clínica de Laboratorios Clínicos, CIBER de Fragilidad y Envejecimiento, Ibs.Granada, Complejo Hospitalario de Granada, 18016-Granada, Spain.
authors.forename: Tomás
authors.initials: T
authors.lastname: de Haro
authors.affiliation: f Centro Andaluz de Medicina del Deporte, Granada, and Hospital San Juan de Dios, 18001-Granada, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: de Teresa-Galván
authors.affiliation: g Departamento de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Granada, 18011-Granada, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Guerra-Hernández
authors.affiliation: a Instituto de Biotecnología, Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada, 18016-Granada, Spain.|b Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016-Granada, Spain.
authors.forename: Iryna
authors.initials: I
authors.lastname: Rusanova
authors.affiliation: a Instituto de Biotecnología, Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada, 18016-Granada, Spain.|b Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016-Granada, Spain.
authors.forename: Marisol
authors.initials: M
authors.lastname: Fernández-Ortiz
authors.affiliation: a Instituto de Biotecnología, Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada, 18016-Granada, Spain.|h Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Sohag University, Sohag, Egypt.
authors.forename: Ramy K A
authors.initials: RKA
authors.lastname: Sayed
authors.affiliation: a Instituto de Biotecnología, Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada, 18016-Granada, Spain.|b Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016-Granada, Spain.|e Unidad de Gestión Clínica de Laboratorios Clínicos, CIBER de Fragilidad y Envejecimiento, Ibs.Granada, Complejo Hospitalario de Granada, 18016-Granada, Spain.
authors.forename: Germaine
authors.initials: G
authors.lastname: Escames
authors.affiliation: a Instituto de Biotecnología, Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada, 18016-Granada, Spain.|b Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016-Granada, Spain.|e Unidad de Gestión Clínica de Laboratorios Clínicos, CIBER de Fragilidad y Envejecimiento, Ibs.Granada, Complejo Hospitalario de Granada, 18016-Granada, Spain.
authors.forename: Darío
authors.initials: D
authors.lastname: Acuña-Castroviejo
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000975:Antioxidants / Q000008:administration & dosage*; D001219:Aspartate Aminotransferases / Q000097:blood; D056352:Athletes; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D004032:Diet; D019587:Dietary Supplements; D004311:Double-Blind Method; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology; D005978:Glutathione / Q000097:blood; D019803:Glutathione Disulfide / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008550:Melatonin / Q000008:administration & dosage*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D010084:Oxidation-Reduction / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects; D055070:Resistance Training; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D014280:Triglycerides; D002784:Cholesterol; D007770:L-Lactate Dehydrogenase; D005979:Glutathione Peroxidase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D003402:Creatine Kinase; D005978:Glutathione; D008550:Melatonin; D019803:Glutathione Disulfide
keywords: antioxidants; antioxydants; athletes; athlètes; exercice physique; exercise; melatonin; muscle squelettique; mélatonine; oxidative stress; skeletal muscle; stress oxydant