부산대학교 도서관

Carotenoids are ubiquitously distributed in nature, β-carotene being the most frequently found carotenoid in the human diet. In the human body, β-carotene is absorbed, distributed and metabolized by enzymatic and/or non-enzymatic oxidant cleavage into several metabolites. Despite the broadly accepted biological value of β-carotene, it has also been considered a double-edged sword, mainly due to its potential antioxidant versus pro-oxidant behaviour. In this sense, the aim of this work was to scrutinize the antioxidant or pro-oxidant potential of β-carotene and its metabolites, namely trans- β-apo-8′-carotenal and β-ionone. Several parameters were evaluated in this study, viz. their effects on reactive species production, both in human whole blood and neutrophils; their effects on lipid peroxidation, in the absence and presence of peroxynitrite anion (ONOO−) or hydrogen peroxide (H 2 O 2), using a synaptosomal model; and finally, their putative genotoxic effects in the human hepatic HepG2 cell line. In general, depending on the cellular model and conditions tested, β-carotene and its metabolites revealed antioxidant effects to varying degrees without significant pro-oxidant or genotoxic effects. Image 1 • trans-β-Apo-8′-carotenal scavenges H 2 O 2 in activated human neutrophils. • β-Carotene inhibits ONOO− - induced lipid peroxidation, in rat brain synaptosomes. • β-Ionone inhibits H 2 O 2 - induced lipid peroxidation, in rat brain synaptosomes. • β-Carotene and its metabolites are not genotoxic in the HepG2 cell model. [ABSTRACT FROM AUTHOR]