Preparation of Rehmanniae Radix Praeparata Polysaccharide Iron(III) Complex and Evaluation of Its Biological Activity

This study extracted and purified a polysaccharide from Rehmanniae radix praeparata (RGP) with an average molecular weight. The structural characteristics of RGP and its iron (III) complex, RGP−Fe(III), were examined for their antioxidant properties and potential in treating iron deficiency anemia (IDA). Analysis revealed that RGP comprised Man, Rha, Gal, and Xyl, with a sugar residue skeleton featuring 1→3; 1→2, 3; and 1→2, 3, 4 linkages, among others. RGP−Fe(III) had a molecular weight of 4.39×104 Da. Notably, RGP−Fe(III) exhibited superior antioxidant activity compared to RGP alone. In IDA rat models, treatment with RGP−Fe(III) led to increased weight gain, restoration of key blood parameters including hemoglobin, red blood cells, and mean hemoglobin content, elevated serum iron levels, and decreased total iron‐binding capacity. Histological examination revealed no observable toxic effects of RGP−Fe(III) on the liver and spleen. These findings suggest the potential of RGP−Fe(III) as a therapeutic agent for managing IDA and highlight its promising antioxidant properties.