Tectorigenin attenuates myocardial damage by doxorubicin-induced ferroptosis by activating the p62-Keap1-Nrf2/HO-1/GPX4 axis.

BACKGROUND: Anticancer agent doxorubicin is essential for cancer treatment but often causes cardiotoxicity. Tectorigenin has shown potential cardioprotective effects, but underlying mechanisms remain unclear. We aimed to investigate whether Tectorigenin attenuates doxorubicin-induced myocardial injury. METHODS: Doxorubicin (DOX) was utilized in C57BL/6J mice and cardiomyocytes H9c2, to establish in vivo and in vitro cardiotoxicity models, then treated with Tectorigenin. The levels of ferroptosis-related factors were measured using specific assay kits. The Liperfluo and DHE stainings were used to detect levels of lipid ROS. Cardiac function in rats was assessed using echocardiography. Immunofluorescence staining was used to detect Nrf2 nuclear translocation. ELISA assay was employed to check serum CK-MB, BNP and Tn-T levels. Cardiac injury and fibrosis were evaluated through HE and Masson stainings. Furthermore, TEM was employed to observe mitochondrial ultrastructure. Western blot and immunofluorescence staining were utilized to detect protein levels. RESULTS: DOX induced ferroptosis in H9c2 cells concentration-dependently and time-dependently, which was alleviated by Tectorigenin treatment. ML385 or K67 abolished Tectorigenin's inhibition on DOX-induced H9c2 cell ferroptosis. Mechanistically, Tectorigenin promoted the expressions of p62 and p-p62, leading to decreased Keap1 expression. This cascade facilitated Nrf2 nuclear translocation and subsequently elevated HO-1 and GPX4 expressions. Moreover, Tectorigenin treatment improved cardiac function, myocardial injury, fibrosis and mitochondrial function in C57BL/6J mice induced by DOX, as well as ferroptosis. CONCLUSION: Our findings reveal that Tectorigenin attenuates DOX-induced ferroptosis and myocardial damage by activating the p62-Keap1-Nrf2/HO-1/GPX4 axis, this may provide a therapeutic strategy for mitigating cardiotoxicity associated with chemotherapeutic agents.