Hypochlorite destroys carotenoids in low density lipoproteins thus decreasing their resistance to peroxidative...

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 approximately 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 CU(2+)-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.