Lactic acid decreases Fe(II) and Fe(III) retention but increases Fe(III) transepithelial transfer by Caco-2 cells.
Lactic acid (LA) has been proposed to be an enhancer for dietary iron absorption, but contradictory results have also been reported. In the present study, fully differentiated Caco-2 cell monolayers were used to evaluate the effects of LA (1-50 mmol/L) on the cellular retention and transepithelial transport of soluble non-heme iron (as ferric nitrilotriacetate). Our data revealed a linear decline in Fe(III) retention with respect to the concentration of LA added. In the presence of 50 mmol/L LA, retention of Fe(III) and Fe(II) decreased 57% and 58%, respectively. In contrast, transfer of Fe(III) across the cell monolayer was doubled, while Fe(II) transfer across the cell monolayer decreased 35%. We conclude that LA reduces cellular retention and transepithelial transport of Fe(II) by Caco-2 cells in a dose-dependent manner. However, while LA also reduces retention of Fe(III) by Caco-2 cells, the transfer of Fe(III) across cell monolayers is enhanced, possibly due to effects on paracellular transport.
Bergqvist
Sharon W
SW
Department of Chemical and Biological Engineering/Food Science, Chalmers University of Technology, Gothenburg, Sweden. sbt@fsc.chalmers.se
Sandberg
Ann-Sofie
AS
Andlid
Thomas
T
Wessling-Resnick
Marianne
M
D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D004848:Epithelium / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism*; D005296:Ferrous Compounds / Q000378:metabolism*; D006801:Humans; D019344:Lactic Acid / Q000494:pharmacology*; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives / Q000378:metabolism
D005290:Ferric Compounds; D005296:Ferrous Compounds; D019344:Lactic Acid; D009571:Nitrilotriacetic Acid; C020326:ferric nitrilotriacetate