Hypochlorite Destroys Carotenoids in Low Density Lipoproteins Thus Decreasing Their Resistance to Peroxidative Modification

O. M. Panasenko,^1,2 O. O. Panasenko,³ K. Briviba,⁴ and H. Sies⁴

¹Institute of Physico-Chemical Medicine, ul. M. Pirogovskaya 1a, Moscow, 119828 Russia; E-mail: panasenko@glas.apc.org

²To whom correspondence should be addressed.

³Department of Biochemistry, School of Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-3955.

⁴Institute of Physiological Chemistry 1, Heinrich Heine University Dusseldorf, 101007, D-40001, Dusseldorf, Germany; fax: (+49) 211-811-3029.

Submitted June 10, 1997.

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The effects of hypochlorite (HOCl/OCl^-) on the content of carotenoids (trans-lycopene, 5-cis-lycopene, alpha- and beta-carotene) and oxycarotenoids (lutein, zeaxanthin, trans- and cis-2´,3´-anhydrolutein, alpha- and beta-cryptoxanthin) in human blood low-density lipoproteins (LDL) were compared using HPLC. Hypochlorite decreased the content of all the above-mentioned pigments in LDL. However, it was more reactive towards carotenoids rather than to their oxy derivatives. The ability of carotenoids and oxycarotenoids to scavenge HOCl/OCl^- decreases in the series: trans-lycopene ~ 5-lycopene > alpha-carotene > beta-carotene > zeaxanthin > alpha-cryptoxanthin > cis-2´,3´-anhydrolutein > beta-cryptoxanthin > trans-2´,3´-anhydrolutein > lutein. Preincubation of LDL with hypochlorite decreased their resistance to Cu²⁺-induced accumulation of dienic conjugates that are produced in the course of lipid peroxidation. The data suggest that hypochlorite-induced destruction of carotenoids in LDL decreases their resistance to oxidative modification, thus promoting the development of early stages of atherosclerosis.

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KEY WORDS: hypochlorite, low-density lipoproteins (LDL), carotenoids, oxycarotenoids, xanthophylls, lipid peroxidation, antioxidants, atherosclerosis.

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