Abstract:
Anti-tumour efficacy of doxorubicin is hindered by the cumulative dose-dependent cardiotoxicity
induced by reactive oxygen species during its metabolism. As Cinnamomum zeylanicum has proven
antioxidant potential, objective of this study was to investigate the cardioprotective activity of
Cinnamomum bark extract against doxorubicin induced cardiotoxicity in Wistar rats. Physicochemical
and phytochemical analysis was carried out and dose response effect and the cardioprotective activity
of Cinnamomum were determined in vivo. 180 mg/kg dexrazoxane was used as the positive control.
Plant extracts were free of heavy metals and toxic phytoconstituents. In vivo study carried out in
Wistar rats revealed a significant increase (p < 0.05) in cardiac troponin I, NT-pro brain natriuretic pep tide, AST and LDH concentrations in the doxorubicin control group (18 mg/kg) compared to the normal
control. Rats pre-treated with the optimum dosage of Cinnmamomum (2.0 g/kg) showed a significant
reduction (p < 0.05) in all above parameters compared to the doxorubicin control. A significant reduction
was observed in the total antioxidant capacity, reduced glutathione, glutathione peroxidase, glutathione
reductase, superoxide dismutase and catalase activity while the lipid peroxidation and myeloperoxidase
activity were significantly increased in the doxorubicin control group compared to the normal control
(p < 0.05). Pre-treatment with Cinnamomum bark showed a significant decrease in lipid peroxidation,
myeloperoxidase activity and significant increase in rest of the parameters compared to the doxorubicin
control (p < 0.05). Histopathological analysis revealed a preserved appearance of the myocardium and
lesser degree of cellular changes of necrosis in rats pre-treated with Cinnamomum extract. In conclusion,
Cinnamomum bark extract has the potential to significantly reduce doxorubicin induced oxidative stress
and inflammation in Wistar rats.
