Lipids protein oxidation

Raw pork patties Black currant extract Inhibit lipid protein oxidation Jia etal., 2012... 

Recent findings from the ATBC stndy even showed that P-carotene snpple-mentation increased the post-trial risk of a hrst-ever non-fatal MI. Two secondary prevention trials, the Heart Protection Stndy and the ATBC presented similar resnlts. The former showed no association between P-carotene and fatal or non-fatal vascular events and the latter reported signihcantly increased risks of fatal coronary events in the P-carotene-snpplemented gronp. Resnlts of clinical trials focused on the effects of carotenoids on CVD biomarkers are controversial. Although carotenoid supplementation increased sernm levels,only lycopene was shown to be inversely associated with lipid, protein, DNA and LDL oxidation, and plasma cholesterol levels. - - ... 

Bhosale, P. and P. S. Bernstein (2005). Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. Biochim. Biophys. Acta 1740(2) 116-121. 

N-AryInitrones (XIII) formed by oxidation of N-hydroxy-N-methyl arylamines, show high reactivity toward carbon-carbon and carbon-nitrogen double bonds in non-aqueous media (21,203) (Figure 10). Under physiological conditions, however, it appears that N-arylnitrones exist as protonated salts that readily hydrolyze to formaldehyde and a primary N-hydroxy arylamine and efforts to detect N-arylnitrone addition products in cellular lipid, protein or nucleic acids have not been successful (204). Nitroxide radicals derived from N-hydroxy-MAB have also been suggested as reactive intermediates (150), but their direct covalent reaction with nucleic acids has been excluded (21). 

Engelman HM, Alekel DL, Hanson LN, Kanthasamy AG and Reddy MB. 2005. Blood lipid and oxidative stress responses to soy protein with isoflavones and phytic acid in postmenopausal women. Am J Clin Nutr 81 590-596. 

Vitamins (C and E), polyphenolic compounds, and carotenoids are the main groups of antioxidants present in fruits and vegetables. Vitamins are single molecules, but polyphenols and carotenoids are made up of hundreds of compounds with a wide range of structures and molecular masses. The intake of these antioxidants can lead to sustained reduction of the kind of oxidative damage to lipids, proteins, and DNA that is associated with the development of chronic diseases (Evans and Halliwell 2001). 

Several compounds can be oxidized by peroxidases by a free radical mechanism. Among various substrates of peroxidases, L-tyrosine attracts a great interest as an important phenolic compound containing at 100 200 pmol 1 1 in plasma and cells, which can be involved in lipid and protein oxidation. In 1980, Ralston and Dunford [187] have shown that HRP Compound II oxidizes L-tyrosine and 3,5-diiodo-L-tyrosine with pH-dependent reaction rates. Ohtaki et al. [188] measured the rate constants for the reactions of hog thyroid peroxidase Compounds I and II with L-tyrosine (Table 22.1) and showed that Compound I was reduced directly to ferric enzyme. Thus, in this case the reaction of Compound I with L-tyrosine proceeds by two-electron mechanism. In subsequent work these authors have shown [189] that at physiological pH TPO catalyzed the two-electron oxidation not only L-tyrosine but also D-tyrosine, A -acetyltyrosinamide, and monoiodotyrosine, whereas diiodotyrosine was oxidized by a one-electron mechanism. 

Similar to lipids the oxidation of proteins has already been studied for more than 20 years. Before discussing the data on protein oxidation, it should be mentioned that many associated questions were already considered in previous chapters. For example, the oxidation of lipoproteins, which is closely connected with the problems of nonenzymatic lipid peroxidation was discussed in Chapter 25. Many questions on the interaction of superoxide and nitric oxide with enzymes including the inhibition of enzymatic activities of prooxidant and antioxidant enzymes are considered in Chapters 22 and 30. Therefore, the findings reported in those chapters should be taken into account for considering the data presented in this chapter. 

In contrast to numerous literature data, which indicate that protein oxidation, as a rule, precedes lipid peroxidation, Parinandi et al. [66] found that the modification of proteins in rat myocardial membranes exposed to prooxidants (ferrous ion/ascorbate, cupric ion/tert-butyl-hydroperoxide, linoleic acid hydroperoxide, and soybean lipoxygenase) accompanied lipid peroxidation initiated by these prooxidant systems. 

On the other hand, in rats, a single dose of 6,156 mg/kg hexachloroethane in mineral oil had no effects on a different set of biochemical indicators of liver function (microsomal protein, oxidative demethylase, NADP-NT reductase, glucose-6-phosphatase, or lipid conjugated diene concentration) when measured 2 hours after compound administration (Reynolds 1972). Each of these parameters is an indicator of microsomal function. The authors postulated that the observed lack of effects could have been the result of slow uptake of hexachloroethane by the liver in a 2-hour period. Gastrointestinal absorption of hexachloroethane in mineral oil is probably minimal because, unlike olive oil, mineral oil cannot be digested. Dissolved lipophilic materials could be excreted in the feces soon after administration because mineral oil can act as a laxative. Thus, the author s hypothesis that minimal hexachloroethane would reach the liver in 2 hours is reasonable. 

Nagasawa, T., Yonekura, T., Nishizawa, N., and Kitts, D. D. (2001). In vitro and in vivo inhibition of muscle lipid and protein oxidation by carnosine. Mol. Cell Biochem. 225,29-34. 

The aim of the present study was to evaluate the effect of LLLT on oxidative markers in serum and tissue biopsies of healing ulcers before and after the 8th session of an LLLT course of chronic leg ulcer treatment. Oxidative damage was assessed in terms of lipid peroxidation reflected by serum malondialdehyde (MDA) level, protein oxidation was measured in terms of tissue protein carbonyls (PCb), and DNA damage was measured in terms of DNA fragmentation. Antioxidative activity was estimated by measuring activity of SOD, GPX and CAT enzymes. 

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