Enzymic Antioxidants

FlavorFicpunct. A substance used in or with a flavor but not essentially a part of it. These include solvents, antioxidants, enzymes, adjusting agents, emulsifiers, and acidulants. 

Two classes of antioxidants are known the low-molecular weight compounds (tocopherols, ascorbate, -carotene, glutathione, uric acid and etc.) and the proteins (albumin, transferrin, caeruloplasmin, ferritin, etc.) including antioxidant enzymes (e.g. superoxide dismutase, catalase, glutathione peroxidase). 

The body maintains an antioxidant network consisting of vitamins A, C, and E, antioxidant enzymes, and a group of related compounds called coenzyme Q, for which the general formula is shown below. The n represents the number of times that a particular group is repeated it can be 6, 8, or 10. Antioxidants are molecules that are easily oxidized, so they react readily with radicals before the radicals can react with other compounds in the body. Many common foods, such as green leafy vegetables, orange juice, and chocolate, contain antioxidants, as do coffee and tea. 

Tian M. Gu Q. Zhu M. (2003) The involvement of hydrogen peroxide and antioxidant enzymes in the process of shoot organogenesis of strawberry callus / / Plant Science. V. 165. P. 701-707. 

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 rice bran phytochemicals and antioxidants have a profound influence on the induction of antioxidant enzymes at the cellular level and control hpid peroxidation at the cellular level. 

Tocotrienols, gamma Oryzanol Phosphatidyl chohne Antioxidants Controls liver cirrhosis and helps in effective liver detoxification (Bruni, 1988). Protectant against hver damage (Kidd, 1996). Antioxidant enzymes prevent hpid peroxidation and helps protecting the liver cells from damage. 

It is possible that dietary flavonoids participate in the regulation of cellular function independent of their antioxidant properties. Other non-antioxidant direct effects reported include inhibition of prooxidant enzymes (xanthine oxidase, NAD(P)H oxidase, lipoxygenases), induction of antioxidant enzymes (superoxide dismutase, gluthathione peroxidase, glutathione S-transferase), and inhibition of redox-sensitive transcription factors. 

Some metabolites of curcumin (particularly tetrahydrocurcumin) may also participate in producing the observed effects of curcumin in different models because these metabolites display greater stabilities than the parent curcumin molecule at physiological pH. Recent data show similar modes of action of curcumin metabolites regarding antioxidant enzyme induction and inhibition of multidrug-resistant proteins. " Additional data indicate that curcumin may even act against other types of diseases such as atherosclerosis " " and Alzheimer s disease. " - " ... 

Punnonen, K., Puntala, A., Jansen, C.T. and Ahotupa, M. (1991a). UVB irradiation induces lipid peroxidation and reduces antioxidant enzyme activities in human keratinocytes in vitro. Acta Dermato-Venereol. 71,... 

Guy, J., Ellis, E., Hope, G. and Rao, N.A. (1989b). Antioxidant enzymes reduce loss of blood-brain barrier integrity m experimental optic neuritis. Arch. Ophthalmol. 107, 1359-1363. 

Repeated periods of exercise reduce the likelihood of damage to skeletal muscle during subsequent bouts of the same form of exercise and this appears to be associated with an increase in the activity of muscle SOD (Higuchi et al. 1985), a reduced level of lipid peroxidation products during exercise in trained rats (Alessio and Goldfarb, 1988), and a modification of the concentration of antioxidants and activity of antioxidant enzymes in trained humans (Robertson etal., 1991). Packer and colleagues (Quintanilha etui., 1983 Packer, 1984) have also examined the exercise endurance of animals of modified antioxidant capacity and found that vitamin E-deficient rats have a reduced endurance capacity, while Amelink (1990) has reported that vitamin E-deficient rats have an increased amount of injury following treadmill exercise. 

White, C.W., Ghezzi, P., McMahon, S., Dinarello, C.A. and Repine, J.E. (1989). Cytokines increase rat lung antioxidant enzymes during exposure to hyperoxia. J. Appl. Physiol. 66, 1003-1007. 

A major contribution of the free-radical scavenging activity in blood plasma is attributable to the macro-molecular proteins (Wayner et al., 1985) of which albumin is a primary component and trapping agertt (Holt et al., 1984). Serum sulphydryl levels, primarily albumin-related, are decreased in subjects with rheumatoid complicated coalworkers pneumoconiosis, indicative of exacerbated inflammatory R.OM production (Thomas and Evans, 1975). Experimental asbestos inhalation in rats leads to an adaptive but evidendy insufficient response by an increase in endogenous antioxidant enzymes (Janssen etal., 1990). Protection of the vascular endothelium against iron-mediated ROM generation and injury is afforded by the iron sequestiant protein ferritin (Balia et al., 1992). 

Experimental in vitro investigations utilizing liposomal-encapsulated and polyethylene glycol-conjugated SOD and catalase have demonstrated the potential value of such means in countering oxidative asbestos-related diseases (Freeman etal., 1985 Mossman etal., 1986). In addition to using supplementary endogenous antioxidant enzymes, the use of iron chelators like desferrioxamine... 

Janssen, Y.M.W., Marsh, J.P., Absher, M., Borm, P.J.A. and Mossman, B.T. (1990). Increases in endogenous antioxidant enzymes during asbestos inhalation in rats. Free Rad. Res. Commun. 11, 53-58. 

Lipid peroxidation (see Fig. 17.2) is a chain reaction that can be attacked in many ways. The chain reaction can be inhibited by use of radical scavengers (chain termination). Initiation of the chain reaction can be blocked by either inhibiting synthesis. of reactive oxygen species (ROS) or by use of antioxidant enzymes like superoxide dismutase (SOD), complexes of SOD and catalase. Finally, agents that chelate iron can remove free iron and thus reduce Flaber-Weiss-mediated iron/oxygen injury. 

Catalase, the antioxidant enzyme that converts hydrogen peroxide to water, has been evaluated in combination with SOD in a model of focal ischaemic stroke in the rat. Both enzymes were eonjugated with polyethylene glycol to increase the circulatory half-life. They significantly reduced inferct volume (Liu et al., 1989). 

Meier, B. W. Gomez, J. D. Kirichenko, O. V. Thompson, J. A. Mechanistic basis for inflammation and tumor promotion in lungs of 2,6-di-tert-butyl-4-methylphenol-treated mice electrophilic metabolites alkylate and inactivate antioxidant enzymes. Chem. Res. Toxicol. 2007, 20, 199-207. 

Garlic s proven mechanisms of action include (a) inhibition of platelet function, (b) increased levels of two antioxidant enzymes, catalase and glutathione peroxidase, and (c) inhibition of thiol enzymes such as coenzyme A and HMG coenzyme A reductase. Garlic s anti-hyperlipidemic effects are believed to be in part due to the HMG coenzyme A reductase inhibition since prescription medications for hyperlipidemia have that mechanism of action (statins). It is unknown whether garlic would have the same drug interactions, side effects, and need for precautions as the statins. 

Breinholt, V., S. T. Lauridsen, B. Daneshvar, and J. Jakobsen. 2000. Dose-response effects of lycopene on selected drug-metabolizing and antioxidant enzymes in the rat. Cancer Lett 154(2) 201-210. 

Lian, F. and X. D. Wang. 2008. Apo-lO -lycopenoic acid, an enzymatic metabolite of lycopene, induces Nrf2-mediated expression of phase II detoxifying/antioxidant enzymes in human bronchial epithelial cells. Int J Cancer (in press). 

Effects of Ethyl 2-Methylacetoacetate (EMA) on the Algal Antioxidant Enzymes Activity 150... 

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