title: Carotenoids, but not vitamin A, improve iron uptake and ferritin synthesis by Caco-2 cells from ferrous fumarate and NaFe-EDTA.
abstract: Due to the high prevalence of iron and vitamin A deficiencies and to the controversy about the role of vitamin A and carotenoids in iron absorption, the objectives of this study were to evaluate the following: (1) the effect of a molar excess of vitamin A as well as the role of tannic acid on iron uptake by Caco-2 cells; (2) iron uptake and ferritin synthesis in presence of carotenoids without pro-vitamin A activity: lycopene, lutein, and zeaxantin; and (3) iron uptake and ferritin synthesis from ferrous fumarate and NaFe-EDTA. Cells were incubated 1 h at 37 °C in PBS pH 5.5, containing (59) Fe and different iron compounds. Vitamin A, ferrous fumarate, β-carotene, lycopene, lutein, zeaxantin, and tannic acid were added to evaluate uptake. Ferritin synthesis was measured 24 h after uptake experiments. Vitamin A had no effect on iron uptake by Caco-2 cells, and was significantly lower from NaFe-EDTA than from ferrous fumarate (15.2 ± 2.5 compared with 52.5 ± 8.3 pmol Fe/mg cell protein, respectively). Carotenoids increase uptake up to 50% from fumarate and up to 300% from NaFe-EDTA, since absorption from this compound is low when administered alone. We conclude the following: (1) There was no effect of vitamin A on iron uptake and ferritin synthesis by Caco-2cells. (2) Carotenoids significantly increased iron uptake from ferrous fumarate and NaFe-EDTA, and were capable of partially overcoming the inhibition produced by tannic acid. (3) Iron uptake by Caco-2 cell from NaFe-EDTA was significantly lower compared to other iron compounds, although carotenoids increased and tannic acid inhibited iron uptake comparably to ferrous fumarate.
authors.affiliation: Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela.
authors.forename: María N
authors.initials: MN
authors.lastname: García-Casal
authors.forename: Irene
authors.initials: I
authors.lastname: Leets
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D018938:Caco-2 Cells; D002338:Carotenoids / Q000494:pharmacology*; D004492:Edetic Acid / Q000737:chemistry; D005293:Ferritins / Q000096:biosynthesis*; D005296:Ferrous Compounds / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007501:Iron / Q000378:metabolism*; D007502:Iron Chelating Agents / Q000737:chemistry; D058085:Iron Compounds / Q000378:metabolism* / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology; D013634:Tannins / Q000494:pharmacology*; D014801:Vitamin A / Q000494:pharmacology*; D014815:Vitamins / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005296:Ferrous Compounds; D007502:Iron Chelating Agents; D058085:Iron Compounds; D010936:Plant Extracts; D013634:Tannins; D014815:Vitamins; D014801:Vitamin A; D002338:Carotenoids; D005293:Ferritins; D004492:Edetic Acid; D007501:Iron; C031621:ferrous fumarate
keywords: Caco-2 cells; NaFe-EDTA; ferritin synthesis; ferrous fumarate; iron uptake