Oxidative stress, effects

The impairment of glucose utilization could result from the modification of the glycolytic enzymes under oxidative stress effects. Oxidative stress is an important factor leading to the pathophysiologcal alterations in conformational diseases. Oxidative stress is manifested in protein oxidation, lipid peroxidation, DNA oxidation, and advanced glycation end-products, as well as reactive oxygen species (ROS), and reactive nitrogen species (RNS) formation. Either the oxidants or the products of oxidative stress could modify the proteins or activate other pathways that may lead to additional impairment of cellular functions and to neuronal loss [57, 58]. 

Beck MA. Nutritionally induced oxidative stress effect on viral disease. Am J Clin Nutr 2000 71 1676S-81S. 

Miyazaki, H., Matsuoka, H., Itabe, H., Usui, M., Ueda, S., Okuda, S., and Imaizumi, T. (2000) Hemodialysis Impairs Endothelial Function Via Oxidative Stress-Effects of Vitamin E-Coated Dialyzer, Circulation 101,1002-1006. 

Chapters 5-7 illustrate the potential for commercial development of a nimiber of promising organometallics. Dubar and Biot describe in detail the mechanism of action of ferroquine, an antimalarial agent in phase II clinical trials at Sanofi Aventis. He shows that this drug can be linked to an oxidizing stress effect and plays a key role in the inhibition of the reinvasion stage of merozoites. This is an important mechanistic discovery that may provide a source of inspiration. 

Lopez-Granero, C., Canadas, E, Cardona, D., et al., 2013. Chlorpyrifos-, diisopropylphosphorofluoridate-, and parathion are they mediated by analogous mechanisms of -induced behavioral and oxidative stress effects action Toxicol. Sci. 131 (1), 206-216. 

The reduced oxidation near sample corners is related to these stress effects, either by retarded diffusion or modified interfacial reactionsManning described these stresses in terms of the conformational strain and distinguished between anion and cation diffusion, and concave and convex surfaces. He defined a radial vector M, describing the direction and extent of displacement of the oxide layer in order to remain in contact with the retreating metal surface, where ... 

Nifurtimox, a nitrofuran, is a prodrug that is reduced to unstable nitroanion radicals, which react to produce highly toxic oxygen metabolites, such as superoxide and peroxide. Oxidative stress subsequently kills the parasite, which seems to lack effective enzymatic pathways to detoxify oxygen metabolites. 

It has been proposed that the development of the complications of diabetes mellitus may be linked to oxidative stress and therefore might be attenuated by antioxidants such as vitamin E. Furthermore, it is discussed that glucose-induced vascular dysfunction in diabetes can be reduced by vitamin E treatment due to the inactivation of PKC. Cardiovascular complications are among the leading causes of death in diabetics. In addition, a postulated protective effect of vitamin E (antioxidants) on fasting plasma glucose in type 2 diabetic patients is also mentioned but could not be confirmed in a recently published triple-blind, placebo-controlled clinical trial [3]. To our knowledge, up to now no clinical intervention trials have tested directly whether vitamin E can ameliorate the complication of diabetes. 

Okada et al. examined the effects of TBT on cellular content of glutathione (GSH) in rat thymocites using a flow cytometer and 5-chloromethylfluorescein diacetate, a fluorescent probe for monitoring the change in the cellular content of GSH. TBT at nanomolar concentrations reduced the cellular content of GSH. There is an important implication on the TBT-induced depletion of cellular GSH since GSH has an important role in protecting the cells against oxidative stress and chemical and metal intoxications. TBT-induced decrease in cellular content of GSH in thymocytes may increase the vulnerability of the immune system. ° ... 

HININGER I A, MEYER-WENGER A, MOSER U, WRIGHT A, SOUTHON S, THURNHAN D, CHOPRA M, VAN CEN BERG H, OLMEDILLA B, FAVIER A E and ROUSSEL A M (2001) No significant effects of lutein, lycopene or beta-carotene supplementation on biological markers of oxidative stress and LDL oxidisability in healthy adult subjects. J Am Coll Nutr. 20(3) 232-238. 

L (1999) Effect of parsley intake on urinary apigenin excretion, blood antioxidant enzymes and on biomarkers for oxidative stress in hiunans, Brit J Nutr, 81, 447-55. 

The protective effects of carotenoids against chronic diseases appear to be correlated to their antioxidant capacities. Indeed, oxidative stress and reactive oxygen species (ROS) formation are at the basis of oxidative processes occurring in cardiovascular incidents, cancers, and ocular diseases. Carotenoids are then able to scavenge free radicals such as singlet molecular oxygen ( O2) and peroxyl radicals particularly, and protect cellular systems from oxidation. 

Curcumin possesses strong antioxidant capacities, which may explain its effects against degenerative diseases in which oxidative stress plays a major role. As previously described for flavonoids, it is unlikely that curcumin acts as a direct antioxidant outside the digestive tract since its concentration in peripheral blood and organs is very low (near or below 1 pM, even after acute or long-term supplementation). Indeed, it has been shown that the intestinal epithelium limits its entry into the body, as reflected by absorption studies in various models (portal blood perfusion, everted bags). ... 

Betalains have shown strong antioxidant activities in biological environments such as membranes and LDLs," -" suggesting that the consumption of betalain-colored foods may exert protective effects against certain oxidative stress-related diseases (i.e., cancers) in humans. Beetroot has been used as a treatment for cancer in Europe for several centuries. The high content of betanin in red beetroot (300 to 600 mg/kg) may be the explanation for the purported cancer chemopreventive effects of beets. 

Results obtained in in vivo and ex vivo experiments are of various types. Some studies have found positive effects of the consumption of carotenoids or foods containing carotenoids on the markers of in vivo oxidative stress, even in smokers. Other studies demonstrated no effects of carotenoid ingestion on oxidative stress biomarkers of lipid peroxidation. " It should be noted that for studies using food, the activity observed may also be partly due to other antioxidant molecules in the food (phenols, antioxidant vitamins) or to the combination of actions of all the antioxidants in the food. 

Another study showed that a mixture of oxidative metabolites of P-carotene, but not P-carotene, was able to increase the binding of benzo[a]pyrene to DNA. Other mixtures of P-carotene cleavage products have been shown to induce oxidative stress in vitro,exert cytotoxic and genotoxic effects, and inhibit gap junction intercellular communications. It has been suggested that these detrimental effects could possibly occur in vivo following the intake of high doses of carotenoids. 

Hoffman DJ, Heinz GH. 1998. Effects of mercury and selenium on glutathione metabolism and oxidative stress in mallard ducks. Environ Toxicol Chem 17 161-166. 

Turner, J.J.O., Rice-Evans, C., Davies, M.J. and Newman, E.S.R. (1991). The formation of free radicals by cardiac myocytes under oxidative stress and the effects of electron-donating drugs. Biochem. J. 277, 833-837. 

While many biological molecules may be targets for oxidant stress and free radicals, it is clear that the cell membrane and its associated proteins may be particularly vulnerable. The ability of the cell to control its intracellular ionic environment as well as its ability to maintain a polarized membrane potential and electrical excitability depends on the activity of ion-translocating proteins such as channels, pumps and exchangers. Either direct or indirect disturbances of the activity of these ion translocators must ultimately underlie reperfiision and oxidant stress-induced arrhythmias in the heart. A number of studies have therefore investigated the effects of free radicals and oxidant stress on cellular electrophysiology and the activity of key membrane-bound ion translocating proteins. 

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