Cardioprotective Effect of Croton macrostachyus Stem Bark Extract and Solvent Fractions on Cyclophosphamide-Induced Cardiotoxicity in Rats

Context. Croton macrostachyus Hochst. ex Delile (Euphorbiaceae) has been used in traditional medicine to manage heart failure and other heart diseases in Ethiopia. Objective. To evaluate the antioxidant and cardioprotective activities of stem bark extract and solvent fractions of Croton macrostachyus on cyclophosphamide-induced cardiotoxicity in rats. Materials and Methods. DPPH free radical scavenging assay method was used to determine antioxidant activity whereas Sprague-Dawley rats were used to evaluate the cardioprotective activity. Except for the normal control, all groups were subjected to cyclophosphamide (200 mg/kg, i.p.) toxicity on the first day. Enalapril at 10 mg/kg was used as a reference. The hydromethanolic crude extract (100, 200, and 400 mg/kg) and aqueous and ethyl acetate fractions (100 and 200 mg/kg, each) were administered for 10 days. The cardioprotective activities were evaluated using cardiac biomarkers such as Troponin I, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total cholesterol (TC), triglyceride (TG), and histopathological studies of heart tissue. Results. Crude extract and ethyl acetate and aqueous fractions exhibited free radical scavenging activities at IC50 of 594 mu g/mL, 419 mu g/mL, and 716 mu g/mL, respectively. Crude extract at 400 mg/kg decreased the levels of troponin, AST, ALT, and ALP to 0.29 +/- 0.06 ng/mL, 103.00 +/- 7.63 U/L, 99.80 +/- 6.18 U/L, and 108.80 +/- 8.81 U/L, respectively. In addition, ethyl acetate fraction at 200 mg/kg decreased the levels of troponin, AST, ALT, and ALP to 0.22 +/- 0.02 ng/mL, 137.00 +/- 14.30 U/L, 90.33 +/- 6.13 U/L, and 166.67 +/- 13.50 U/L, respectively, compared with the cyclophosphamide control group. Conclusions. Croton macrostachyus possesses cardioprotective activities and it could be a possible source of treatment for cardiotoxicity induced by cyclophosphamide.