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.