Acteoside targeting glutamine synthetase ameliorates doxorubicin-induced cardiotoxicity by inhibiting ferroptosis.

BACKGROUND

Doxorubicin-induced cardiotoxicity (DIC) is a severe dose-limiting complication of chemotherapy. Acteoside (ACT), a bioactive phenylethanoid glycoside naturally isolated from various medicinal plants such as Plantago lanceolata and Acanthus ilicifolius, exhibits diverse pharmacological activities. However, its specific role and molecular targets in DIC remain largely unreported.

OBJECTIVE

To evaluate the cardioprotective efficacy of ACT in DIC and identify its direct molecular targets and cardiac protection mechanisms.

METHODS

Proteomic profiling of DOX-treated hearts and AAV9-mediated cardiac-specific silencing were integrated to identify and validate glutamine synthetase (GS) as a pivotal pathological driver of DIC. Subsequently, structure-based virtual screening of phytochemicals was employed to identify ACT as a potent GS inhibitor. The ACT-GS interaction was confirmed via molecular docking, pull-down, and cellular thermal shift assays. Functional and mechanistic validations were conducted using H9C2/HL-1 cells and C57BL/6 J mouse models.

RESULTS

Proteomics revealed significant myocardial GS upregulation and glutamate metabolic remodeling in DIC. ACT was identified as a direct inhibitor that specifically binds to GS. Mechanistically, ACT-mediated GS inhibition prevented pathological glutamate depletion and restored the GLU-GSH-GPX4 antioxidant axis, thereby suppressing lipid peroxidation and ferroptosis both in vitro and in vivo. Consequently, ACT administration significantly attenuated DOX-induced cardiac dysfunction, fibrosis, and myocardial atrophy, effectively recapitulating the protective effects observed with genetic GS knockdown.

CONCLUSION

ACT acts as a potent natural GS inhibitor that alleviates DIC by suppressing ferroptosis. This study establishes ACT as a promising natural lead compound for the management of DIC.