oxygen radical


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Related to oxygen radical: Oxygen radical absorbance capacity

radical

 [rad´ĭ-kal]
1. thorough or sweeping; directed to the cause or root of a morbid process.
2. a group of atoms that enters into and goes out of chemical combination without change and that forms one of the fundamental constituents of a molecule.
color radical chromophore.
free radical a radical that carries an unpaired electron; such radicals are extremely reactive, with a very short half-life.
oxygen radical a toxic metabolite of oxygen, such as superoxide or singlet oxygen, capable of damaging microorganisms and normal tissues.

oxygen radical

Reactive oxygen metabolite Any molecule with an unpaired electron in its outer orbital which leads to an unstable and/or short half-life, which is capable of reducing or oxidizing other molecules. See Oxygen free radicals.

oxygen radical

Hydrogen peroxide (H2O2) or the superoxide radical (O2) produced by the incomplete reduction of oxygen. Oxygen free radicals are released during the respiratory burst phase of phagocytosis by neutrophils and macrophages during inflammation. They cause direct cell damage, increase vascular permeability through damage to the capillary endothelium, and promote chemotaxis. Oxygen free radicals are normally contained by antioxidant protective measures; however, with severe inflammation they cause significant damage. They are believed to be responsible for much of the cellular damage involved in adult respiratory distress syndrome (ARDS), in which massive neutrophil aggregation and phagocytosis occur.
See also: radical
References in periodicals archive ?
Hyperhomocysteinemia is a situation characterized by increased production of reactive oxygen radicals, and folate deficiency, which leads to reduced bioavailability of NO and endothelial dysfunction.
Oxidative stress may also play a role in the pathogenesis of alcoholic liver disease, and several mechanisms contribute to the generation of excessive oxygen radicals or the reduction of antioxidant levels (Ishi et al.
Among these factors, osteoclastic activity, cytokines, chronic inflammations, endotoxins, and lipid peroxidation products may be mentioned but recently the focus is increased on free oxygen radicals and nitric oxide (6,7).
22,23] Increased uric acid might be a consequence of increased cell turnover because of exaggerated haemolysis or an attempt to scavenge increased free oxygen radicals as uric acid also behaves as a powerful antioxidant and scavenger of singlet oxygen radicals.
Oxygen Radical absorbance capacity of ascorbic acid is found to be more than Gallic acid and cafeic acid and this is the reason for good results of vitamin C (ORAC value 12.
When the Oxygen Radical Absorbance Capacity (ORAC) assay was first developed and used in the analysis of foods some 17 years ago, it provided a useful measure of the amount of phytochemicals, primarily flavonoids and related phenolic and polyphenolic compounds, in foods.
Proof of the benefit of Ambrotose AO supplementation, as measured by increased serum oxygen radical antioxidant capacity (ORAC), has been confirmed in three human clinical trials.
Eating strawberries also improved other parameters such as the general plasma lipid profile, antioxidant biomarkers (such as vitamin C or oxygen radical absorbance capacity), antihemolytic defences and platelet function.
Researchers estimated a woman's antioxidant capacity based on a database that measures the oxygen radical absorption capacity (ORAC) of common foods, and on food-frequency questionnaires filled out by the study's participants.
Said to be a first-of-its-kind dietary line, Lichi Super Fruit is obtained from 100% lychee extract, which has been scientifically proven to offer numerous health benefits because of its high oxygen radical absorbance capacity value, rich antioxidant content and ability to oxidize fat.
The addition reaction between C = C and the isopropylbenzene oxygen radical is considered to represent the curing reaction of methyl vinyl SR (26), (29).
Containing phosphatidyl choline, omega-3 fatty acids, carotenoids and antioxidants with an average oxygen radical absorbance capacity (ORAC) value of 378, krill oil may play an important role in brain and eye development and health, protecting cells from free radical damage.