Dietary iron supplementation attenuates doxorubicin-induced cardiotoxicity by improving myocardial iron homeostasis and reducing ferroptosis-associated injury in mice.

Iron deficiency frequently accompanies chronic heart failure (CHF) and is linked to adverse clinical outcomes. Although intravenous iron replacement has shown clinical benefit in heart failure, whether increasing dietary iron intake can provide cardioprotective effects remains uncertain. In this study, we examined the effects of dietary iron supplementation in a murine model of doxorubicin (Dox)-induced cardiotoxicity. Mice were treated with Dox at 2.5 mg/kg by intraperitoneal injection once weekly for 6 weeks and received either standard chow containing 45 ppm iron or ferric citrate-enriched chow containing 5,000 ppm iron. We assessed cardiac function, myocardial injury, fibrosis, apoptosis, mitochondrial ultrastructure, oxidative stress, transcriptomic changes, and iron metabolism-related proteins through echocardiography, histological examination, biochemical assays, RNA sequencing, and Western blot analysis. In Dox-treated mice, the iron-enriched diet was associated with better survival and cardiac performance, together with less myocardial damage, fibrosis, apoptosis, mitochondrial injury, and oxidative stress. Transcriptomic analysis revealed enrichment of ferroptosis-related pathways in hearts exposed to Dox. Dox exposure also disturbed cardiac iron handling, as reflected by abnormal myocardial iron distribution, higher transferrin receptor 1 (TFR1) and nuclear receptor coactivator 4 (NCOA4) abundance, and lower ferritin heavy chain 1 (FTH1) expression. Most of these changes shifted toward control levels after dietary iron supplementation, while SLC7A11 abundance was unaffected. Taken together, our findings suggest that dietary iron supplementation mitigates Dox-induced cardiac injury, accompanied by improved myocardial iron homeostasis and attenuation of ferroptosis-related injury. Changes in NCOA4 and FTH1 abundance may reflect altered ferritin turnover and potentially contribute to the observed cardioprotective effects.