| Carotenoids as plant pigments have been implicated in disease prevention through their antioxidant activity. The goal of this project was to explore the potential effects of β-carotene, lycopene, and lutein on specific monocyte-macrophage actions characteristic of differentiation: reduced proliferation, synthesis (NBT reduction and LDL oxidation) and cell adhesion to substratum. A human pro-monocyytc leukemic cell line, U937, was used as a model. Cellular concentrations of specific carotenoids were increased by incubation with medium containing serum enriched in vitro with specific carotenoids. At cell carotenoid levels of 100–580 ng/mg cell protein, all carotenoids inhibited proliferation, and to a lesser extent, increased NBT reduction. LDL oxidation and adhesivness were unaffected. These studies are consistent with altered monocyte-macrophage proliferation or differentiation in the presence of elevated cellular carotenoid concentrations. |
