Free Radicals and Tissue Damage: Role of Antioxidants

Abstract

Cells generate energy by reducing molecular oxygen to water. During the process, small amounts of partially reduced reactive oxygen forms are produced as unavoidable byproducts which are referred to as Reactive Oxygen Species. An imbalance between free radical-generating and radical scavenging systems results in Oxidative Stress. Reactive nitrogen species and other non reactive derivatives are also involved. These processes lead to tissue damage and contribute to the pathogenesis of many disorders like hypertension, cancer, diabetes, neurodegenerative disorders and others. The human body has several mechanisms to counter the effects of these reactive species by the production of antioxidant enzymes like glutathione and catalase. Antioxidants can also be taken exogenously through the diet. This article provides an overview of the different free radicals known, the mechanism by which they cause tissue damage and the protective role played by different antioxidants.

The role of myricetin fromRhodomyrtus tomentosa(Aiton) Hassk fruits on downregulation of FcɛRI‐mediated mast cell activation

“…Free radical is a reactive atom containing an unpaired electron in an atomic orbital (Rao, Kalva, Yerramilli, & Mamidi, 2011). It was reported to associate with the upregulation of mast cell activation and degranulation (Mannaioni & Masini, 1988).…”

Antioxidantes e inhibición de radicales libres: lipoperoxidación y carbonilación

“…La lipoperoxidción (LPO) es un proceso que es generado por los radicales libres principalmente el radical hidroxilo, el cual tiene una gran afinidad por los ácidos grasos poliinsaturados que conforman una parte de los fosfolípidos de la membrana celular, sin embargo también se ven afectados los grupos hemo de los pigmentos, los aminoácidos de las proteínas y los dobles enlaces de las vitaminas (Sailaja 2011, Insani et al, 2008. La oxidación lipídica se lleva a cabo mediante un mecanismo autocatalítico de radicales libres (autooxidación), este proceso se realiza a través de tres fases: iniciación, propagación y terminación (Fernández et al, 1997).…”

Relationship between vitamin intake and total antioxidant capacity in elderly adults

“…The oxidative stress involved in the pathogenesis of these diseases is a consequence of the increased production of free radicals (FR) and the inability of the human body's antioxidant systems to counteract the negative effects (Rao et al 2011) leading to tissue damage, a product of the oxidative alteration of macromolecules such as lipids and DNA (Diplock et al 1998). …”