Of cholesterol oxides

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. 

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. 

Physical Barriers. Wu et al (46) observed that the inclusion of palmitic acid or cholesteryl acetate in linoleic acid monolayers on silica, exerted a protective effect against oxidation. They suggested that these compounds act as a spacer keeping the linoleic acid molecules farther apart while being only slowly oxidized themselves. Similarly, our recent work with cholesterol oxidation appears to indicate that carbohydrates do not change the pathway of cholesterol oxidation but rather act as a physical barrier against the migration of reactive species. 

Hodis, H.N., Crawford, D.W., Sevanian, A. 1991. Cholesterol feeding increases plasma and aortic tissue cholesterol oxide levels in parallel further evidence for the role of cholesterol oxidation in artherosclerosis. Artherosclerosis 89, 117-126. 

Table 18.1. Nomenclature and Abbreviations of Cholesterol Oxidation Products...

Figure 18.7. Major pathways of cholesterol oxidation A, CHOL B, 7-OOH (7< -and 7(3-OOH) C, 7-OH (7a-and 7(3-OH) D, 7-keto E, epoxides (a-and (3-epoxides), ki-ks, rate constants of the reactions of cholesterol oxidation. For abbreviations, see Table 18.1.

Angulo, A.J., Romera, J.M., Ramirez, M., Gil, A. 1997. Determination of cholesterol oxides in dairy products. Effect of storage conditions. 1. Agric. Food Chem. 45, 4318 1323. 

Dutta, P.C., Savage, G.P. 2002. Harmonization of cholesterol oxidation product analysis. In Cholesterol and Phytosterol Oxidation Products Analysis, Occurrence, and Bological Effects (F. Guardiola, P.C. Dutta, R. Codony, G.P. Savage, eds.), pp. 114-123, AOCS Press, Champaign, IL. 

Dutta, P.C., Carboni, M.F., Diczfalusy, U., Dionisi, F., Dzeletovic, S., Grandgirard, A., Guardiola, F., Kumpulainen, J., Lebovics, V.K., Pihlava, J.R., Rodriguez-Estrada, M.T., Ulberth, F. 1999. Measurement of cholesterol oxides in foods results of an interlaboratory comparison study. In Natural Antioxidants and Anticarcinogens in Nutrition, Health and Diseases (J.T. Kumpulainen, J.T. Salonen, eds.), pp. 309-315, Royal Society of Chemistry, London. 

Lai, S.-M., Gray, J.I., Buckley, D.J., Kelly, P.M. 1995. Influence of free radicals and other factors on formation of cholesterol oxidation products in spray-dried whole egg. J. Agric. Food Chem. 43, 1127-1131. 

Linseisen, J., Wolfram, G. 1998. Absorption of cholesterol oxidation products from ordinary foodstuffs in humans. Arm. Nutr. Metab. 42, 221-230... 

Morgan J.N., Armstrong, D.J. 1992. Quantification of cholesterol oxidation products in egg yolk powder spray-dried with direct heating. J. Food Sci. 57, 43-45. 

Prasad, C.R., Subramanian, R. 1992. Qualitative and comparative studies of cholesterol oxides in commercial and home-made Indian ghees. Food Chem. 45, 71-73. 

Rose-Sallin, C., Huggett, A.C., Bosset, J.O., Tabacchi, R., Fay, L.B. 1995. Quantitation of cholesterol oxidation products in milk powder using [2Hy] cholesterol to monitor cholesterol autoxidation. J. Agric. Food Chem. 43, 935-941. 

Smith, L.L. 1992. The oxidation of cholesterol. In Biological Effects of Cholesterol Oxides (S-K. Peng, R.J. Morin, eds.), pp. 7-31, CRC Press, Boca Raton, FL. 

Stanton, C., Devery, R. 2002. Formation and content of cholesterol oxidation products in milk and dairy products. In Cholsterol and Phytosterol Oxidation Products Analysis,... 

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