Organic acids influence iron uptake in the human epithelial cell line Caco-2.
It has previously been suggested that organic acids enhance iron absorption. We have studied the effect of nine organic acids on the absorption of Fe(II) and Fe(III) in the human epithelial cell line Caco-2. The effect obtained was dose-dependent, and the greatest increase (43-fold) was observed for tartaric acid (4 mmol/L) on Fe(III) (10 micromol/L). Tartaric, malic, succinic, and fumaric acids enhanced Fe(II) and Fe(III) uptake. Citric and oxalic acid, on the other hand, inhibited Fe(II) uptake but enhanced Fe(III) uptake. Propionic and acetic acid increased the Fe(II) uptake, but had no effect on Fe(III) uptake. Our results show a correlation between absorption pattern and chemical structure; e.g. hydroxyl groups, in addition to carboxyls, were connected with a positive influence. The results may be important for elucidating factors affecting iron bioavailability in the small intestine and for the development of foods with improved iron bioavailability.
D000042:Absorption; D019342:Acetic Acid / Q000494:pharmacology; D018938:Caco-2 Cells / Q000187:drug effects* / Q000378:metabolism*; D002264:Carboxylic Acids / Q000494:pharmacology*; D019343:Citric Acid / Q000494:pharmacology; D005290:Ferric Compounds / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D005650:Fumarates / Q000494:pharmacology; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008293:Malates / Q000494:pharmacology; D019815:Oxalic Acid / Q000494:pharmacology; D011422:Propionates / Q000494:pharmacology; D019802:Succinic Acid / Q000494:pharmacology; D013644:Tartrates / Q000494:pharmacology
D002264:Carboxylic Acids; D005290:Ferric Compounds; D005296:Ferrous Compounds; D005650:Fumarates; D008293:Malates; D011422:Propionates; D013644:Tartrates; D019343:Citric Acid; C030298:malic acid; C032005:fumaric acid; D019815:Oxalic Acid; D019802:Succinic Acid; D007501:Iron; C029658:propionic acid; D019342:Acetic Acid; C029768:tartaric acid