Cardioprotective activity of ethanolic extract of Callistemon lanceolatus leaves on doxorubicin-induced cardiomyopathy in rats

The cardioprotective effect of ethanol extract of Callistemon lanceolatus leaves (100 and 200 mg/kg) against doxorubicin-induced cardiomyopathy was studied. Rats were pretreated with the extract for 7 days and simultaneous treatment with doxorubicin along with the extracts for the next 14 days. After 24 hours of last dose of doxorubicin, ECG, invasive blood pressure, serum markers (creatine kinase-MB, lactate dehydrogenase, serum transaminases), tissue antioxidant markers (catalase, superoxide dismutase) and extent of lipid peroxidation (malondialdehyde) were studied. The elevated ST segment, decreased blood pressure, increased level of serum enzymes and decreased level of tissue antioxidant markers were observed in doxorubicin treatment (p<0.01). While 200 mg/kg extract significantly reduced the elevated levels of the serum enzymes and restores the ECG and blood pressure to normal, also significantly increased the tissue antioxidant levels, while decreased the malondialdehyde level (p<0.01) when compared with the control. The histopathological study confirmed the cardioprotection.