Oxidation cholesterol

Increasing the degree of unsaturation of PUFA increases the concentration of labile bis allylic hydrogen atoms, making it more likely that one of 

---

Tart cherries Cirmamic acid derivatives, anthocyanins and flavonols dominate Raw and cooked beef patties Reduces secondary lipid oxidation and cholesterol oxidation products up to 90% Britt et al., 1998... 

Enrichment of processed food with plant material or plant extracts rich in polyphenols has two aspects in relation to human nutrition and human health. Food protected against oxidation has better keeping quality and will stay healthy longer since formation of toxic oxidation products, like cholesterol oxides, is being prevented (Britt et al., 1998). The other aspect is the beneficial effects of the intake of polyphenols on human health. Both of these aspects are, however, related to the availability of the phenolic substances. 

XU z, HUA N, GODBER s (2001) Antioxidant activity of tocopherols, tocotrienols, and y-oryzanol components from rice bran against cholesterol oxidation accelerated by 2, 2 -azobis(2-methylpropionamidine) dihydrochloride. J Agri Food Chem, 49 2077-81. 

Studies conducted by Barenghi eta.1. (1990) and Lodge etal. (1993) independently have demonstrated the facile, multicomponent analysis of a wide range of PUFA-derived peroxidation products (e.g. conjugated dienes, epoxides and oxysterols) in samples of oxidized LDL by high-field H-NMR spectroscopy. Figure 1.9 shows the applications of this technique to the detection of cholesterol oxidation products (7-ketocholesterol and the 5a, 6a and 5/3,60-epoxides) in isolated samples of plasma LDL pretreated with added coppcr(Il) or an admixture of this metal ion with H2O2, an experiment conducted in the authors laboratories. 

Steroids Cholesterol oxidation (haem) Zn fingers Haem oxidation... 

Spectra of the greasy wool are more complicated than in the previous study. In negative ion mode, different fatty acids, fatty alcohols and alkanes are detected, whereas the positive ion mode shows mainly the presence of cholesterol and the cholesterol oxidation product (Figure 15.6). These ions are attributed to the presence of wool wax on the surface of raw wool. 

As mentioned earlier, oxidation of LDL is initiated by free radical attack at the diallylic positions of unsaturated fatty acids. For example, copper- or endothelial cell-initiated LDL oxidation resulted in a large formation of monohydroxy derivatives of linoleic and arachi-donic acids at the early stage of the reaction [175], During the reaction, the amount of these products is diminished, and monohydroxy derivatives of oleic acid appeared. Thus, monohydroxy derivatives of unsaturated acids are the major products of the oxidation of human LDL. Breuer et al. [176] measured cholesterol oxidation products (oxysterols) formed during copper- or soybean lipoxygenase-initiated LDL oxidation. They identified chlolcst-5-cnc-3(3, 4a-diol, cholest-5-ene-3(3, 4(3-diol, and cholestane-3 3, 5a, 6a-triol, which are present in human atherosclerotic plaques. 

Napoli et al. [286] found that the nifedipine treatment of stroke-prone spontaneously hypertensive rats (SPSHR) suppressed the plasma and LDL oxidation and the formation of oxidation-specific epitopes and increased the survival of rats independently of blood pressure modification. Their results suggest that the protective effects of calcium blockers of dihydro-pyridine-type on cerebral ischemia and stroke may, at least in part, depend on their antioxidant activity. In vivo antioxidant effect of nilvadipine on LDL oxidation has been studied in hypertensive patients with high risk of atherosclerosis [287], It was found that there was a significant decrease in the level of LDL cholesterol oxidation in patients after nilvadipine treatment. 

E. J. Smart, Y. S. Ying, P. A. Conrad, and R. G. Anderson. Caveolin moves from caveolae to the Golgi apparatus in response to cholesterol oxidation. J. Cell Biol. 127 1185-1197 (1994). 

Chang, Y.H., Abdalla, D.S., and Sevanian, A., 1997, Characterization of cholesterol oxidation products formed by oxidative modification of low density lipoprotein. Free Radio. Biol. Med. 23 202-214. 

An evaporative light scattering detector was coupled with a UV spectrophotometer, and was applied to HPLC for the quantitative determination of cholesterol oxides in edible oils and fats. 

Dutta, P.C., Caboni, M.F., Diczfalusy, U., Dionisi, F., and Dzeletovic, S. 1999. Measurements of cholesterol oxides in foods Results of an interlaboratory comparison study. Spec. Publ. R. Soc. Chem. 240 309-315. 

Study looking for good universal method for determination of eight analogs of cholesterol oxides in egg and milk powders. The results indicate difficulty in working with various food samples such as mixed diets. 

By separation of cholesterol oxides from cholesterol by TLC, it became possible to determine small amounts of cholesterol oxides by the enzymatic method even in the presence of a quantity of cholesterol. 

Prygonski, K., Jelen, H., and Wasowicz, E. 2000. Determination of cholesterol oxidation products in milk powder and infant formulas by gas chromatography and mass spectrometry. Nahrung 44 122-125. 

Ong W. Y., Goh E. W. S., Lu X. R., Farooqui A. A., Patel S. C., and Halliwell B. (2003). Increase in cholesterol and cholesterol oxidation products, and role of cholesterol oxidation products in kainate-induced neuronal injury. Brain Path. 13 250-262. 

Smith LL, Teng JI, Kulig MJ, Hill FL. Sterol metabolism. XXIII. Cholesterol oxidation by radiation-induced processes. J Org Chem 1973 38 1763-1765. 

Moriel, P., Sevanian, A., Ajzen, S., Zanella, M.T., Plavnik, F.L., Rubbo, H., and Abdalla, D.S. 2002. Nitric oxide, cholesterol oxides and endothelium-dependent vasodialation in plasma of patients with essential hypertension. Braz. J. Med. Biol. Res. 35, 1301-1309. 

Aviram, M., and Fuhrman, B., Wine flavonoids, LDL cholesterol oxidation and atherosclerosis, in Wine A scientific exploration, Sandler, M. and Pinder, R.M. (eds.), Taylor Francis, London, 140, 2003. 

---