oxidative stress

oxidative stress,

1 any of various pathologic changes seen in living organisms in response to excessive levels of cytotoxic oxidants and free radicals in the environment.

2 use of antioxidant intake in the diet to provide both preventive and therapeutic advantage and reduce the damaging effects of free radicals on cellular constituents.

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oxidative stress,

n an imbalance of the prooxidant antioxidant ratio in which too few antioxidants are produced or ingested or too many oxidizing agents are produced.

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oxidative stress 

A term used to describe the effect of oxidation in which an abnormal level of reactive oxygen species (ROS), such as the free radicals (e.g. hydroxyl, nitric acid, superoxide) or the non-radicals (e.g. hydrogen peroxide, lipid peroxide) lead to damage (called oxidative damage) to specific molecules with consequential injury to cells or tissue. Increased production of ROS occurs as a result of fungal or viral infection, inflammation, ageing, UV radiation, pollution, excessive alcohol consumption, cigarette smoking, etc. Removal or neutralization of ROS is achieved with antioxidants, endogenous (e.g. catalase, glutathione, superoxide dismutase) or exogenous (e.g. vitamins A, C, E, bioflavonoids, carotenoids). Oxidative damage to the eye, particularly the retina and the lens, is a contributing factor to age-related macular degeneration and cataract.

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oxidative stress

The presence of oxygen free radicals, which are generated by various stressants–eg, tobacco, alcohol; the primary antioxidant is glutathione; other antioxidants include vitamins A, C, and E; ↑ oxidative stress may be one of the key factors in the early pathogenesis of AIDS in which the production of TNF ↑ the production of free radicals in T cells. See Free radicals.