ABSTRACT
Oxidative stress is part of the more general term environmental stress, but the former primarily causes the response of components of the oxidative stress response system, whereas the latter also includes subjects such as proteotoxic, metal, and genotoxic stress. Oxidative stressors are intermediates of oxygen reduction processes, such as respiration, of redox reactions, and of the metabolism of chemicals. The enzyme systems participating in the cellular defense against oxidative stress and contributing to a cellular homeostasis by metabolizing endogenous harmful intermediates. The hydroxyl radical is a major component of oxidative damage and is considered the most potent oxidant in biological systems. Oxidative stress is initiated by a variety of stimuli causing an array of effects, which may be related to inhibition of enzymatic activity, disturbance of metabolic processes, disturbance of signal transduction, and damage to DNA and cellular structures.
