Related Experiment Videos
Inositol phosphates influence iron uptake in Caco-2 cells.
E Skoglund1, B Lönnerdal, A S Sandberg
1Department of Food Science, Chalmers University of Technology, SE-402 29 Göteborg, Sweden. es@fsc.chalmers.se
Journal of Agricultural and Food Chemistry
|December 20, 1999
Summary
Phytate (InsP(6)) and its breakdown products, inositol phosphates (InsP(5)), significantly inhibit iron uptake. Lower forms like InsP(4) and InsP(3) showed no effect at low concentrations, suggesting specific interactions impacting iron absorption.
Area of Science:
- Nutritional Biochemistry
- Food Science and Technology
- Human Physiology
Background:
- Phytate (inositol hexaphosphate, InsP(6)) is a common plant-derived compound that can be hydrolyzed into lower inositol phosphates (InsP(5)-InsP(1)) during food processing.
- These lower inositol phosphates exist in various isomeric forms, potentially influencing their biological activity.
- Understanding the interaction between inositol phosphates and mineral absorption is crucial for optimizing nutrient bioavailability.
Purpose of the Study:
- To investigate the impact of different inositol phosphate isomers (InsP(3)-InsP(5)) and InsP(6) on iron uptake in vitro.
- To determine if the isomeric form of inositol phosphates influences their inhibitory effect on iron absorption.
- To assess the dose-dependent effects of various inositol phosphates on iron absorption.
Main Methods:
- In vitro study using the human intestinal epithelial cell line, Caco-2.
- Incubation of Caco-2 cells with varying concentrations of InsP(6), InsP(5), InsP(4), and InsP(3) isomers and iron (Fe).
- Quantification of iron uptake after incubation periods at 37°C.
Main Results:
- A 2-fold molar excess of InsP(6) or InsP(5) significantly reduced iron uptake by 46-52% (p < 0.001).
- InsP(4) and InsP(3) isomers did not significantly affect iron uptake at a 2:1 InsP:Fe molar ratio after 1-hour incubation.
- At a 20:1 InsP:Fe molar ratio, InsP(4) showed an inhibitory effect, while InsP(3) did not impact iron absorption.
Conclusions:
- Inositol hexaphosphate (InsP(6)) and inositol pentaphosphates (InsP(5)) significantly inhibit in vitro iron uptake.
- The inhibitory effect on iron absorption is not dependent on the isomeric form of the inositol phosphates studied.
- Lower inositol phosphates (InsP(4) and InsP(3)) have minimal impact on iron absorption at low concentrations, but InsP(4) can inhibit at higher levels.