Bioavailability of iron from plant and animal ferritins.

Iron deficiency is a major public health problem in the world. Ferritin is being explored as a novel and natural strategy for iron supplementation. The objective of this study was to evaluate iron bioavailability from ferritin isolated from plant and animal sources. The stability of plant ferritin and animal ferritin was studied by in vitro and in vivo digestion to determine whether these ferritins can pass through the gastrointestinal tract in intact form. Results from sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot indicate that both plant ferritin and animal ferritin can resist digestion (both under acidic and moderately acidic conditions). Furthermore, ferritin was labeled with (59)Fe, and bioavailability of iron from ferritin was assessed by uptake into Caco-2 cells. Our results indicate that iron is taken up from the ferritins and that iron bioavailability from soybean ferritin (rH-1:rH-2=1:1) is the highest. These results may be explained by the binding of ferritin to Caco-2 cells, which can be attributed to the interaction between ferritin and its putative receptor(s) at the surface of Caco-2 cells. In conclusion, ferritin from plant and animal sources may be developed as an iron source.