This study compares the absorption characteristics of two iron-based dietary supplements and their biocompatibility to bisglycinate iron, a common chelated iron form. The Caco-2 cell line-a model of human intestinal absorption-and GTL-16 cell line-a model of gastric epithelial cells-were used to perform the experiments; in the first experiments, the kinetics of absorption have been evaluated analyzing the divalent metal transporter 1 (DMT1) expression. Three different iron combinations containing 50 µM iron (named Fisioeme®, Sideral® and bisglycinate) were used for different stimulation times (1-24 h). After this, the effects of the three iron formulations were assessed in both a short and a long time, in order to understand the extrusion mechanisms. The effects of the three different formulations were also analyzed at the end of stimulation period immediately after iron removal, and after some time in order to clarify whether the mechanisms were irreversibly activated. Findings obtained in this study demonstrate that Fisioeme® was able to maintain a significant beneficial effect on cell viability compared to control, to Sideral®, and to iron bisglycinate. This observation indicates that Fisioeme® formulation is the most suitable for gastric and intestinal epithelial cells.
Keywords: Caco-2 permeability; DMT1 receptor; GTL-16 permeability; iron mechanisms; iron metabolism.