The study evaluated the cardioprotective and antioxidant activity of onion (Allium cepa) leaves extract in Doxorubicin (DOX) induced cardiotoxicity in rats. In this study twenty four male Albino Wistar rats weighing between 200-250g were used. The animals were treated as follows. Group 1: animals served as control and received saline (0.9%)10ml/kg/p.o, Group 2: animals received doxorubicin 10mg/kg, i.v once 48 h before sacrifice. Group 3: animals received vitamin E (4mg/kg/p.o.,) for 14 days followed by Doxorubicin, Group 4: animals received aqueous Allium cepa leaves extract of (200mg/kg/day/p.o.,) for 14 days followed by Doxorubicin. In each group, body wt of rats were taken before and after Doxorubicin administration. After 48 hrs of doxorubicin administration blood was collected for serum CK-MB and LDH estimation. Isolated hearts were dried and weighed. In the heart tissues superoxide dismutase (SOD) & catalase (CAT), glutathione (GSH) and malondialdehyde (MDA) were estimated. Results showed that the mean heart weight/body weight (HW/BW) ratio in group 2 was significantly (p<0.001) decreased, CKMB (p<0.01), LDH (p<0.05) increased, GSH (p<0.01) decreased, MDA (p<0.01) increased, SOD and CAT (p<0.01) enzymes were decreased as compared to group 1. Group 3, 4 has shown significant (p<0.001) increase in (HW/BW) ratio, decrease in CKMB and LDH levels (p<0.01), GSH levels were significantly (p<0.01) increased, MDA levels significantly decreased (p<0.01), SOD and CAT enzymes levels significantly (p<0.01) increased as compared to group 2. It may be concluded that the aqueous extract of A.cepa leaves posseses cardioprotective and antioxidant activity in doxorubicin induced cardiotoxicity in rats.
