Resumo

LOZANO CASANOVA, Jorge; BARRIOS, María Antonia  e  PEDROSA AMADO, Andrés. Free radicals and antioxidants. Realities and perspectives. Bibliographical review. AMC [online]. 1997, vol.1, n.2, pp. 0-0. ISSN 1025-0255.

Among molecular mechanisms that may cause injury and cellular death, the most studied in recent years is the one produced by the free radicals released in oxidation reactions mediated by oxygen. Free radical production of oxygen constitutes a normal process, considering that the 5% of oxygen that penetrates the cell is transformed into one of the following radicals; superoxide ion, hydrogen peroxide or hydroxil radical. The noxious effect of these radicals on the biological membranes and DNA, is prevented by the existence of defense molecular mechanisms such as: SOD enzyme, glutathione peroxide and catalase, or vitamins such as Vitamin C, Vit. A, Vit. E, and Selenium. Unbalances among the generation of free radicals and the antioxidant capacity of the body generates a state known as "Oxidative Stress" which is responsible for the cellular and tissular damages associated with different pathological states. In this review, mechanisms are analyzed through which different antioxidants function, the relationship among the "Oxidative Stress" and some degenerative diseases. Some experiences about the possibility of using antioxidants in the treatment of these ailments and the nutrition importance as a way of preventing free radical effects for the body are described.

Palavras-chave : FREE RADICALS; ANTIOXIDANTS.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )