Oxygen, free radicals

Production of ROS, factors involved in the aging process (Finkel and Holbrook, 2000), is elevated in AD brain and may be an important cause of AD (Martins et al., 1986). Elevated levels of oxicUzed hpids (lipid peroxidation, maloncUaldehyde, 4-hydroxynonenal) (Markesbery and Carney, 1999), proteins (advanced glycation end product mocUfications, tyrosine nitration) (Good et al., 1996 Takeda et al., 1998), and nucleic acids (8-hydroxy-deoxyguanosine) have been documented in AD brains (Lyras et al., 1997). Mitochondria and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex 

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Ascorbic acid—vitamin C—is an essential nutrient that the human body cannot manufacture from other compounds. It is needed for the formation of collagen, the protein that makes up connective tissue, and is essential to muscles, bones, cartilage, and blood vessels. It is a strong antioxidant, preventing damage from oxygen free radicals. 

BHA is an antioxidant. It reacts with oxygen free radicals. It can thus slow down the rate at which ingredients in a product oxidize in direct contact with air, a process that can cause changes in the taste or color. BHA can be added to the food itself, or to the packaging material, and it is used primarily to prevent fats from becoming rancid. 

Propyl gallate is an antioxidant. It protects against oxidation by hydrogen peroxide and oxygen free radicals in a catalytic manner similar to superoxide dismutase. 

Polyunsaturated fats can combine easily with oxygen at the points where there is a double bond between two carbon atoms. This is why they make good antioxidants they combine with the oxygen free radicals so they don t damage other molecules. It is also how oils harden, and is thus important to painters. Oil paints made with linseed oil are almost three-quarters trilinolein. They dry to form a tough plastic film that incorporates the pigments and holds them onto the surface to be painted. 

Some colors are nutrients in their own right, and they have antioxidant properties that are beneficial to health. Beta-carotene, annatto, saffron, and turmeric all have these good properties in addition to their color. In fact, the same chemistry that makes them absorb light also helps them to absorb and neutralize dangerous oxygen free radicals in the body. 

Benzoyl peroxide can help remove dead skin cells, which in turn prevents the pores from clogging up. It also kills the Propionibac-terium acnes bacterium that causes acne. It has anti-inflammatory effects and reduces oxygen free radicals and fatty acids on the skin. 

Allopurinol 1 mM Xanthine oxidase inhibitor, suppresses oxygen free radical production... 

Aizenman E, Hartnett KA, Reynolds IJ Oxygen free radicals regulate NMDA receptor function via a redox modulatory site. Neuron 5 841—846, 1990... 

Halliwell, B. and Gutteridge, J.M.C. (1986). Oxygen free radicals and iron in relation to biology and medicine—some problems and concepts. Archives of Biochemistry and Biophysics 246, 501-514. 

Raha S, Robinson BH Mitochondria, oxygen free radicals, disease and aging. Trends Biochem Sci 2000 25 502. 

Coetzee, W.A. and Opie, L.Fl. (1992). Effects of oxygen free radicals on isolated cardiac myocytes from guinea-pig ventricle Electrophysiological studies. J. Mol. Cell. Cardiol. 24, 651-663. 

Jackson, C.V., Mickelson, J.K., Pope, T.K., Rao, P.S. and Lucchesi, B.R. (1986). Oxygen free radical mediated myocardial and vascular dysfunction. Am. J. Physiol 251, H1225-H1231. 

Kaneko, M., Beamish, R.E. and Dhalla, N.S. (1989). Depression of heart sarcolemmal Ca-pump activity by oxygen free radicals. Am. J. Physiol. 256, H368-H374. 

Cao, W., Carney, J.M., Duchon, A., Floyd, R.A. and Chevion, M. (1988). Oxygen free radical involvement in ischemia and reperfiision injury to brain. Neurosci. Lett. 88, 233-238. 

Floyd, R.A. (1990). Role of oxygen free radicals in carcinogenesis and brain ischemia. FASEB J. 4, 2587-2597. 

McIntosh, L.J., Trush, M.A. and Troncoso, J.C. (1991). Oxygen-free radical mediated processes in Alzheimer s disease. Soc. Neurosci. Abstr. 17, 1071. 

Koyama, L, Bulkley, G.B., Williams, G.H. and Im, H.J. (1985). The role of oxygen free radicals in mediating the reperfusion injury of cold-preserved ischaemic kidneys. Transplantation 40, 590-595. 

Paller, M.S., Hoidal, J.R. and Ferris, T.F. (1984). Oxygen free radicals in ischaemic acute renal failure in the rat. J. Clin. Invest. 74, 1156-1164. 

Human chronic inflammatory diseases are characterized by populations of cells with altered regulation and function. A large body of evidence suggests that many of these cellular abnormalities may be linked to an increase in the production of free radicals and/or deficiencies of antioxidant defence systems. Oxygen free radicals attack cell structures, altering their function, and are cytotoxic. They have therefore been implicated in the pathogenesis of rheumatoid arthritis as well as many other human diseases (HaUiwell, 1991). 

Winyard, P.G. and Blake, D. R. (1989). Caeruloplasmin and oxygen free radicals. In Free Radicals, Metal Ions and Biopolymers (eds. C.P. Beaumont, D.J. Deeble, B. J. Parsons and C. Rice-Evans) pp. 183-197. Richelieu, London. 

Hull, D.S. and Green, K. (1989). Oxygen free radicals and corneal endothelium. Lens Eye Toxic Res. 6, 89-91. 

Reoxygenation following transient anoxia increases oxygen free radical formation by isolated rat hepatocytes. Hepatology 16, 159A. 

Del Soldato, P., Foschi, D., Benoni, G. and Scarpignato, C. (1985). Oxygen free radicals interact with indomethacin to cause gastrointestinal injury. Agents Actions 17, 484-488. 

Filez, L.E.A., Kerremans, R., Gebocs, K., Stalmans, W. and Penninckx, F. (1990). Oxygen free radicals are the most important oxygen species involved in the development of reperfusion lesions. Gastroenterolt 98, A169. 

Inauen, W., Bilzer, M., Rowedder, E., Halter, F. and Lauterbutg, B.H. (1988). Decreased gjutathione (GSH) in colonic mucosa of patients with inflammatory bowel disease mediated by oxygen free radicals Gastroenterology 94, A199. 

Ma, T.Y., Hollander, D., Freeman, D., Nguyen, T. and Krugliak, P. (1991). Oxygen free radical injury of IEC-18 small intestinal epithelial cell monolayers. Gastroenterology 100, 1533-1543. 

Moyana, T. and Lalonde, J.M. (1991). Carrageenan-induced intestinal injury, possible role of oxygen free radicals. Ann. Clin. Lab. Sci. 21, 258-263. 

Mozsik, G., Siito, G., Garamszegi, M., Javor, T., Nagy, L., Vineze, A. and Zsoldos, T. (1991). Oxygen free radicals and gastric mucosal damage in rats treated with ethanol and HCl Eur. J. Gastroenterol. Hepatol. 3, 757-761. 

Stein, H.J., Oosthuizen, M.M., Hinder, R.A. and Lamprechts, H. (1991). Oxygen free radicals and glutathione in hepatic ischaemia/reperfusion injury. J. Surg. Res. 50, 398-402. 

Takeuchi, K., Ueshima, K., Hironaka, Y., Fujioka, Y., May-sumoto, J. and Okabe, S. (1991a). Oxygen free radicals and lipid peroxidation in the pathc nesis of gastric mucosal lesions induced by indomethadn in rats. Relation to gastric hypermotility. Digestion 49, 175-184. 

Tamura, K., Manabe, T., Ohshio, G., Ando, K., Yotsumoto, F., Kyogoku, T., Imanishi, K. and Tobe, T. (1991a). Effect of oxygen free radicals on the rat pancreas in vivo. Gastroenterology 100, A844. 

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