Melatonin and their protective role on oxidative cell damage: Interplay between oxidative stress and tumorigenesis

• Autor(a) principal: de Almeida Chuffa, Luiz Gustavo [UNESP]
• Data de Publicação: 2013
• Outros Autores: Fioruci, Beatriz Aparecida [UNESP], Seiva, Fábio Rodrigues Ferreira [UNESP]
• Tipo de documento: Capítulo de livro
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/227598

Melatonin, an indolamine produced by pineal gland at night, has been implicated in the treatment of many dysfunctions including oxidative disorders, apoptosis, and cancer. It is indisputable that melatonin represents an important molecule used for antioxidant therapies at cellular levels, preventing subsequent changes that results in cell damage. Melatonin is a very potent free radical scavenger, reactive species which can be extremely deleterious to macromolecules into the cells. Direct antioxidant properties of melatonin have been shown both in vitro and in vivo. Alternatively, melatonin also stimulates several antioxidant activities, protecting the cells from oxidative stress. Thus, to focus on the antioxidant effects of melatonin, several experimental and clinical studies have been carried in an attempt to assess the activity of melatonin towards radicalinduced damage. The cell oxidation is one of the main causes leading to tumorigenic process. Recently, a wide range of studies has focused attention on the positive correlation between major cell signaling-induced cancer, such as the MAP kinase and PI3K/Akt pathways, and the increasing oxygen/nitrogen species formation. Particularly, melatonin has a dual effect on intracellular redox state regarding its antiproliferative action and its cytotoxic effect directly to cancer cells. As far as we could investigate, there is no compiled data regarding melatonin, oxidative stress and cancer studies which we believe to be extremely important for the hormone divulgation and to encourage further researches. This chapter briefly presents a review of the melatonin metabolism (biosynthesis, distribution, cellular responsiveness, and degradation), followed by an introductory topic to the free radicals world, broaching the main mechanisms in which they participate, and their consequences. The next topics include the extensively studied relations between free radicals and cancer development (addressing some specific and aggressive cancer types), focusing on standard and alternative treatment methodologies. © 2013 by Nova Science Publishers, Inc. All rights reserved.