Protective effect of Azadirachta indica a. Juss against doxorubicin-induced cardiac toxicity in tumour bearing mice.

Doxorubicin (DOX) treatment (12 microg/g body weight, once a week for 2 weeks) resulted in a significant decrease in the heart rate along with an increase in QRS, ST, and QT intervals. Histopathological studies showed cardiomyocyte degeneration, cytoplasmic vacuolation and macrophage infiltration in cardiac tissue. A marked increase in the rate of apoptosis was also observed. An increased oxidative stress was evidenced by significantly higher levels of lipid peroxidation (LPO) and depletion of reduced glutathione. A decrease in the activity of cellular antioxidant defence enzymes was also observed. The decrease in the heart rate and ECG alterations were prevented significantly by AAILE (100 microg/g body weight, po) co-treatment, started two weeks prior to DOX treatment and continued till the termination of the experiment. The cardioprotection was also evident from histopathology and decrease in the rate of apoptosis in cardiomyocytes. AAILE co-treatment also prevented DOX-induced increase in LPO and decrease in antioxidant defence enzymes. The results suggest that AAILE administration prevents DOX-induced cardiotoxicity.