Eugenol attenuates paclitaxel-induced cardiotoxicity by modulating autophagy-related markers in rats

Objective(s): Paclitaxel (PTX) is a commonly used chemotherapeutic agent that causes cardiotoxicity characterized by oxidative stress, inflammation, and mitochondrial dysfunction, which disrupts autophagy and apoptosis in cardiomyocytes. This study investigated the therapeutic potential of eugenol (EUG), a natural anti-oxidant and anti-inflammatory compound, against PTX-induced cardiac damage. Materials and Methods: Thirty-six male Wistar rats were randomly assigned to six groups: Control, EUG5, EUG25, PTX, PTX+EUG5, and PTX+EUG25. Hemodynamic parameters (systolic and diastolic blood pressure and heart rate), serum cardiac biomarkers (troponin T and brain natriuretic peptide), histopathological alterations, and immunohistochemical expression of autophagy-related proteins (mTOR, ULK1, and Atg13) were evaluated. Results: PTX administration significantly reduced arterial blood pressure and increased serum cardiac injury biomarkers, accompanied by marked myocardial structural damage. Histopathological analysis revealed myocardial degeneration, inflammation, edema, and tissue disorganization in the PTX group. In PTX-exposed rats treated with EUG, arterial blood pressure was higher, and serum cardiac injury biomarkers were lower than in the PTX group, accompanied by reduced histopathological scores. PTX exposure was associated with decreased mTOR expression and increased ULK1 and Atg13 immunoreactivity, while EUG-treated PTX groups showed values closer to those of the control group for these autophagy-related markers. Conclusion: EUG administration was associated with reduced biochemical and histopathological indicators of cardiac injury in PTX-exposed rats, along with changes in autophagy-related markers. These findings demonstrate that EUG treatment coincided with attenuation of PTX-induced cardiac injury at the biochemical and histopathological levels, suggesting its potential experimental value in models of chemotherapy-associated cardiotoxicity.