Eleutheroside E Attenuates Doxorubicin-Induced Cardiotoxicity by Suppressing Ferroptosis Through Activation of the Nrf2/SLC7A11/GPX4 Signaling Pathway

Doxorubicin (DOX)-induced cardiotoxicity significantly impairs cancer patient survival rates. Eleutheroside E (EE), a polyphenolic compound with established cardioprotective properties against high-altitude myocardial injury and ischemia/reperfusion damage, has not previously been investigated in the context of DOX-induced cardiac toxicity. This study aimed to elucidate the therapeutic potential of EE against DOX-associated cardiotoxicity and its underlying mechanisms. Cardiomyocyte viability was quantified using the CCK-8 assay and Hoechst 33342/PI dual staining. Cardiac function was evaluated by echocardiography. Morphological alterations in cardiomyocytes were analyzed through phalloidin, hematoxylin-eosin (H&E), and wheat germ agglutinin staining. Ferroptosis-related biomarkers including malondialdehyde (MDA), Ptgs2 mRNA levels, Fe2+ concentration, and lipid peroxidation were assessed respectively. EE administration attenuated DOX-induced cardiomyocyte atrophy in-vitro and improved cardiac function in-vivo. Mechanistically, EE counteracted DOX-mediated suppression of Nrf2 expression and inhibited ferroptosis via activation of the Nrf2/SLC7A11/GPX4 signaling axis. siRNA-mediated Nrf2 knockdown partly abolished EE's cardioprotective effects. These findings conclusively demonstrate that EE mitigates DOX-induced cardiotoxicity through Nrf2-dependent ferroptosis regulation, highlighting its therapeutic potential for preventing chemotherapy-associated cardiac complications.