title: A review of metal-catalyzed molecular damage: protection by melatonin.
abstract: Metal exposure is associated with several toxic effects; herein, we review the toxicity mechanisms of cadmium, mercury, arsenic, lead, aluminum, chromium, iron, copper, nickel, cobalt, vanadium, and molybdenum as these processes relate to free radical generation. Free radicals can be generated in cells due to a wide variety of exogenous and endogenous processes, causing modifications in DNA bases, enhancing lipid peroxidation, and altering calcium and sulfhydryl homeostasis. Melatonin, an ubiquitous and pleiotropic molecule, exerts efficient protection against oxidative stress and ameliorates oxidative/nitrosative damage by a variety of mechanisms. Also, melatonin has a chelating property which may contribute in reducing metal-induced toxicity as we postulate here. The aim of this review was to highlight the protective role of melatonin in counteracting metal-induced free radical generation. Understanding the physicochemical insights of melatonin related to the free radical scavenging activity and the stimulation of antioxidative enzymes is of critical importance for the development of novel therapeutic strategies against the toxic action of these metals.
authors.affiliation: Departamento de Toxicología y Farmacología, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Romero
authors.forename: Eva
authors.initials: E
authors.lastname: Ramos
authors.forename: Cristóbal
authors.initials: C
authors.lastname: de Los Ríos
authors.forename: Javier
authors.initials: J
authors.lastname: Egea
authors.forename: Javier
authors.initials: J
authors.lastname: Del Pino
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
mesh_terms: D002384:Catalysis; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004249:DNA Damage; D005609:Free Radicals / Q000737:chemistry / Q000378:metabolism; D015227:Lipid Peroxidation; D008550:Melatonin / Q000737:chemistry / Q000378:metabolism*; D019216:Metals, Heavy / Q000737:chemistry / Q000378:metabolism*; D018384:Oxidative Stress
chemical_list: D005609:Free Radicals; D019216:Metals, Heavy; D004247:DNA; D008550:Melatonin
keywords: chelating properties; free radicals; melatonin; metals; oxidative stress