Dietary supplementation with ipriflavone decreases hepatic iron stores in wild type mice

Hepcidin, a peptide produced in the liver, decreases intestinal iron absorption and macrophage iron release by causing degradation of the iron exporter, ferroportin. Because its levels are inappropriately low in patients with iron overload syndromes, hepcidin is a potential drug target. We previously conducted a chemical screen that revealed ipriflavone, an orally available small molecule, as a potent inducer of hepcidin expression. To evaluate ipriflavone's effect on iron homeostasis, we placed groups of 5-week old wild type or thalassemia intermedia (HbbTh3 +/−) mice on a soy-free, iron-sufficient diet, AIN-93G containing 220 mg iron and 0–750 mg ipriflavone/kg of food for 50 days. Ipriflavone 500 mg/kg significantly reduced liver iron stores and intestinal ferroportin expression in WT mice, while increasing the ratio of hepcidin transcript levels to liver iron stores. Ipriflavone supplementation in HbbTh3 +/− mice failed to alleviate iron overload and was associated with a milder reduction in intestinal ferroportin and a failure to alter the ratio of hepcidin transcript levels to liver iron stores or splenic expression of the hepcidin-regulatory hormone, erythroferrone. These data suggest that dietary supplementation with ipriflavone alone would not be sufficient to treat iron overload in thalassemia intermedia.