Potent antioxidative activity of lycopene: a potential role in scavenging hypochlorous acid

Abstract

Lycopene, a carotenoid that imparts a red color in tomatoes, is a proven anti‐oxidant that may lower the risk of certain diseases. Hypochlorous acid (HOCl) is an oxidant generated by a two electron oxidation of chloride, catalyzed by the neutrophil derived myeloperoxidase. Although HOCl plays a key role in the host immune response, it is also linked to tissue oxidation in cardiovascular disease and other inflammatory disorders through its ability to modify proteins, DNA, and lipids. Here we show that lycopene can function as a potent scavenger of HOCl at a wide range of concentrations that span various physiological and supplemental ranges. The oxidation of lycopene by HOCl was accompanied by a marked change in color, from red to colorless, of the lycopene solution suggesting lycopene degradation. HPLC and LC‐MS analysis showed that the exposure of lycopene to increasing concentrations of HOCl gave a range of metabolites resulting from oxidative cleavage of one or more carbon‐carbon double bonds. The degree of degradation of lycopene (as assessed by the number and chain lengths of the different oxidative metabolites of lycopene) depends mainly on the ratio between HOCl to lycopene, suggesting that multiple molecules of HOCl are consumed per molecule of lycopene. This work demonstrates the link between lycopene and HOCl scavenging, and provides contribution to the mechanism of the protective function exerted by lycopene.