The protective role of carotenoids against 7-keto-cholesterol formation in solution
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The antioxidant activity of β-carotene and oxygenated carotenoids lutein, canthaxanthin, and astaxanthin was investigated during spontaneous and peroxyl-radical-induced cholesterol oxidation. Cholesterol oxidation, measured as generation of 7-keto-cholesterol (7-KC), was evaluated in a heterogeneous solution with cholesterol, AAPH, and carotenoids solubilized in tetrahydrofuran and in water, and in a homogeneous solution of chlorobenzene, with AIBN as a prooxidant. The formation of 7-KC was dependent on temperature and on cholesterol and prooxidant concentrations. All the carotenoids tested, exhibited significant antioxidant activity by inhibiting spontaneous, AAPH- and AIBN-induced formation of 7-KC, although the overall order of efficacy of these compounds was astaxanthin > canthaxanthin > lutein = β-carotene. The finding that carotenoids exert protective effects on spontaneous and free radical-induced cholesterol oxidation may have important beneficial effects on human health, by limiting the formation of atheroma and by inhibiting cholesterol oxidation in food processing or storage.
KeywordsCholesterol oxidation 7-keto-cholesterol formation Carotenoids Antioxidant activity Heterogeneous solution
Cholesterol oxidation products
This work was supported by MIUR.
- 11.Nielsen JH, Olsen CE, Jensen C, Skibsted LH (1996) Cholesterol oxidation in butter and dairy spread during storage. J Dairy Sci 63:159–167 Google Scholar
- 13.Shozen K, Ohshima T, Ushio H, Koizurni C (1995) Formation of cholesterol oxides in marine fish products induced by grilling. Fish Sci 61:817–821Google Scholar
- 14.Zimin P, Evangelisti F, Calcagno C, Tiscomia E (1996) Cholesterol oxidation in dried egg pasta: Detecting 7-ketocholesterol content. Cereal Chem 73:691–694Google Scholar
- 18.Watanabe K, Nakamura R, Hosono A (1988) Mutagenic activity of heat-induced cholesterol-degradation products. J Food Sci 38:119–123Google Scholar
- 25.Lizard G, Monier S, Cordelet C, Gesquiere L, Deckert V, Gueldry S, Lagrost L Gambert P (1999) Characterization and comparison of the mode of cell death, apoptosis versus necrosis, induced by 7β-hydroxycholesterol and 7-ketocholesterol in the cells of the vascular wall. Arterioscler Thromb Vasc Biol 19:1190–1200PubMedGoogle Scholar
- 39.Chang YH, Abdalla DSP, Sevanian A (1996) Characterization of cholesterol oxidation products formed by oxidative modification of low density lipoprotein. Free Radic Biol Med 2:202–214Google Scholar
- 42.Palozza P, Serini S, Di Nicuolo F, Boninsegna A, Torsello A, Maggiano N, Ranelletti FO, Wolf FI, Calviello G, Cittadini A (2004) beta-Carotene exacerbates DNA oxidative damage and modifies p53-related pathways of cell proliferation and apoptosis in cultured cells exposed to tobacco smoke condensate. Carcinogenesis 25:1315–1325PubMedCrossRefGoogle Scholar
- 49.Woodal AA, Lee SW, Weesie RJ, Jackson MJ, Britton G (1997) Oxidation of carotenoids by free radicals: relationships between structure and reactivity. Biochim Biophys Acta 1336(1):33–42Google Scholar