Preparation and in vitro absorption studies of a novel polysaccharide‑iron (III) complex from Flammulina velutipes

Iron is essential in fundamental bioactivities, so it makes sense to improve the efficiency of iron on epithelial transport. In this work, a novel polysaccharide‑iron(III) complex (FVP-Fe(III)) was prepared from Flammulina velutipes with a specific structure. The FVP-Fe(III) had a molecular weight of 15.13 kDa with a monosaccharide composition of mannose, galacturonic acid, glucose, galactose, xylose, fucose in a molar ratio 3.6:2.1:60.8:18.7:3.9:10.9. In the vitro digestion model, the complex could maintain better solubility and steady of iron than FeSO₄. In the cell assay, FVP-Fe(III) showed lower cytotoxicity and better absorption. The transport amount of FVP-Fe(III) was 1.5-fold of FeSO₄ at same concentration and 1.8-fold of FeSO₄ at same time. The transport was mediated by the peptide transporter (pepT1) active transport pathway and the efflux of the sample was mainly mediated by multidrug-resistance proteins (MRP) transporter. The results of this study suggested that the polysaccharide obtained from F. velutipes could be developed a new kind of iron delivery for further study.