Abstract
Background:
Doxorubicin (DOX), an anthracycline antibiotic, is a powerful chemotherapeutic agent effective against multiple types of cancer, particularly lung, breast, bladder and hematologic neoplasia (lymphomas and leukemia). However, its therapeutic usage is restricted by its known cardiotoxicity, which is associated with the production of oxidative stress. Enhancing antioxidant capacity represents a promising approach to mitigate DOX-induced cardiotoxicity. Hesperidin (HES), a citrus bioflavonoid, possesses several pharmacological effects, such as anti-inflammatory and antioxidant characteristics.
Aim:
This study was designed to evaluate the cardiotoxicity of DOX and assess the possible cardioprotective role of HES.
Methods:
Groups of Wistar rats were either treated with doxorubicin (4 mg/kg. bw., once a week for 5 consecutive weeks, intraperitoneally) or received co-treatment with hesperidin (100 mg/kg. bw./day in distilled water, 5 days in a week for 5 consecutive weeks, administered orally). Heart and blood samples were obtained for histological, immunohistochemical, and biochemical assessments.
Results:
DOX administration resulted in severe cardiotoxicity, as evidenced by significant elevations in cardiac biomarkers, including Troponin I (CTnI), Creatine kinase (CK-Total), Creatine kinase isoenzyme-MB (CK-MB), lactate dehydrogenase (LDH), and Aspartate aminotransferase (AST). DOX also elevated pro-inflammatory cytokines, such as Interferon γ (IFN-γ), Interleukin 1β (IL-1β), and Tumor necrosis factor α (TNF-α). Furthermore, DOX induced oxidative stress and substantially reduced the levels of antioxidant enzymes, including Glutathione peroxidase (GPX), Superoxide dismutase (SOD), and Catalase (CAT). Histopathologically, DOX caused severe Zenker's necrosis, cardiomyocyte disarray, sarcoplasmic vacuolizations, cardiomyocyte congestion, and inflammatory cell infiltration. Immunohistochemically, DOX exhibited extensive apoptosis, as indicated by strong positive immuno-localization against anti-caspase-3 antibody. In contrast, co-treatment with HES protected cardiac tissues against cardiotoxicity of DOX, as indicated by the amelioration of histological abnormalities and the normalization of biochemical values.
Conclusion:
We can conclude that DOX induces severe cardiotoxicity characterized by oxidative stress, inflammation, pathological alterations, and apoptosis. Co-treatment with HES demonstrates significant cardioprotective effects by virtue of its potent anti-inflammatory, antioxidant, cytoprotective, and antiapoptotic characteristics.

Key words: Doxorubicin, Hesperidin, Cardioprotective, Cardiotoxicity, Oxidative damage