Free radicals scavengers for

A wide range of iron chelators have been shown to inhibit ribonucleotide reductase [144-146] and this is likely to be the explanation of the cytotoxic properties of such molecules. Some iron chelators may also function as free radical scavengers. For instance, hydroxyurea appears to inhibit the enzyme by this latter mode of action [144], Such inhibitory agents block the cell division cycle in the S-phase because replication of cellular DNA is arrested. This also suggests possible therapeutic applications. 

Pennstop . [Atochem N. Am.] N < Diethylhydioxylamine free radical scavenger for rubber industry as an emulsion polymerizatimi inhibitor va> por phase inhibitor fa olefin or styrene monomer recovery systens. 

Uses Botanical, antioxidant, free radical scavenger for cosmetics natural flavoring agent in foods... 

Uses Antioxidant, light stabilizer, free radical scavenger for polyolefins, polyesters, ABS, pipe, crates, drums,... 

CAS 8002-47-9 EINECS/ELINCS 232-309-3 Synonyms Vitulus Definition Extract of bovine livers Uses Biological additive, skin conditioner in cosmetics free radical scavenger for cosmetic anti-aging preps. 

In order to reduce phototoxicity due to free radicals forming by photobleach-ing of the fluorophores during time-lapse microscopy, ascorbic acid (1 (rg/ml) or oxyrase (30 mM) may be added to the medium as free radical scavengers. For long-term observations (longer than two hours) the culture medium should be covered with mineral oil (from Sigma) to avoid the culture medium drying out. 

Slemmer JE, Shacka JJ, Sweeney MI, Weber JT (2008) Anti-oxidants and free radical scavengers for the treatment of stroke, traumatic brain injury and aging. Curr Med Chem 15 404 14... 

There are, indeed, many biological implications that have been triggered by the advent of fullerenes. They range from potential inhibition of HIV-1 protease, synthesis of dmgs for photodynamic therapy and free radical scavenging (antioxidants), to participation in photo-induced DNA scission processes [156, 157, 158, 159, 160, 161, 162 and 163]. These examples unequivocally demonstrate the particular importance of water-soluble fullerenes and are summarized in a few excellent reviews [141, 1751. 

Rather scanty evidence exists for the participation of free radicals in Alzheimer s disease and Down s syndrome. However, more recendy, reports have appeared that suggest possible free-radical involvement in the pathogenesis of these two conditions. Zemlan et al. (1989) repotted that the activity of the free-radical scavenging enzyme, SOD, was significantly increased in fibroblast cell lines derived from familial Alzheimer s and Down s patients. They hypothesized that the elevation in SOD activity observed in the Alzheimer patients supports the theory that paired helical filaments are formed by free-radical hydroxylation of proline residues. They further su ested that SOD levels might also be increased in the brains of Alzheimer s and Down s patients, and that the increase in SOD may reflect an enhanced generation of free radicals. 

The most extensive evidence that supports a role for free radicals in pathological conditions of the brain is provided by studies on experimental models of cerebral ischaemia/reperfusion. Although a burst of free-radical production occurs during the reperfusion phase after temporary cerebral ischaemia, the contribution of this radical burst to brain cell death can not be directly quantified. Perhaps the best way to quantify the contribution of free radicals to brain damage after ischaemia/ reperfusion is to assess damage after treatment with free-radical scavengers or antioxidants. Numerous studies have been reported where free-radical scavengers/ antioxidants have been used to try to ameliorate brain... 

It should be remembered that some of the established antioxidants have other metabolic roles apart from free-radical scavenging. The finding of reduced antioxidant defences in diabetes, for example, may not be prima fascie evidence of increased oxidative stress, since alternative explanations may operate. For example, this may reflect a response to reduced free-radical activity as su ested by the results of a previous study (Collier et al., 1988). In the case of ascorbate, an alternative explanation has been proposed by Davis etal. (1983), who demonstrated competitive inhibition of ascorbate uptake by glucose into human lymphocytes. This view is supported by the similar molecular structure of glucose and ascorbic acid (see Fig. 12.4) and by a report of an inverse relationship between glycaemic control and ascorbate concentrations in experimental diabetes in rats. Other investigators, however, have not demonstrated this relationship (Som etal., 1981 Sinclair etal., 1991). 

Dimethylsulfoxide (DMSO) is the antidote of choice for anthracycline and mitomycin C extravasations. It readily penetrates tissues and increases diffusion in the tissue area. In addition, DMSO is a free-radical scavenger that functions to block this principal mechanism of anthracycline- and mitomycin C-mediated tissue injury. DMSO generally is well tolerated but may cause some mild burning and redness. Dexrazoxane is a free-radical scavenger typically used for cardio-protection from anthracyclines. Promising results have been seen with large-volume extravasations and in a mouse model.38... 

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