Abstract:
Objective To investigate the protective effect and underlying mechanisms of HydroMg, a novel sustained-release hydrogen donor, in a model of doxorubicin (DOX)-induced chronic cardiotoxicity.
Methods H9C2 cells were treated with 1 μmol/L DOX and/or 1 μg/mL HydroMg, and mitochondrial membrane potential, reactive oxygen species (ROS) levels, and apoptosis were measured. In the animal experiment, mice were divided into control, HydroMg, DOX, and DOX+HydroMg groups. The HydroMg group received intraperitoneal injection of HydroMg (100 mg/kg). Chronic cardiotoxicity was established by intraperitoneal injection of DOX (5 mg/kg every week) for four consecutive weeks; In the DOX+HydroMg group, HydroMg (100 mg/kg) was administered intraperitoneally 4–5 h prior to each DOX injection. Cardiac function and remodeling were evaluated by echocardiography and heart weight index (HWI). The long-term survival of mice were analyzed. Subsequently, transcriptome sequencing was performed on myocardial tissues from the DOX group to identify key molecular alterations compared with controls.
Results At the cellular level, HydroMg treatment effectively reversed DOX-induced mitochondrial dysfunction and oxidative stress, as evidenced by restored membrane potential, reductions in total ROS and mitochondrial superoxide levels by approximately 30% and 9%, respectively, and a decrease in the apoptosis rate from 34.13% to 18.27%. In the animal model, compared with the DOX group, HydroMg intervention increased left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) by 9.62% and 5.82%, respectively, attenuated the reduction in HWI (4.41 mg/mm vs 3.53 mg/mm), and improved the 4-week survival rate (80% vs 60%). Transcriptomic analysis revealed that the core molecular features of DOX-induced cardiotoxicity, including widespread suppression of oxidative phosphorylation and antioxidant pathways.
Conclusions HydroMg protects against DOX-induced chronic cardiotoxicity by alleviating oxidative stress and improving mitochondrial function, and provides a potential therapeutic strategy against DOX-related cardiotoxicity.