Cardioprotective Effect of Leaf and Root Extracts of Newbouldia laevis against Carbon Tetrachloride Induced-Cardiotoxicity in Albino Rats

Various parts of Newbouldia laevis are used by traditional medicine practitioners in Eastern Nigeria for treatment/management of several disorders, including cardiovascular diseases. This study was designed to investigate cardioprotective potential of aqueous leaf and root extracts of the plant in albino rats. Forty-four (44) adult male albino rats, used in this study, were placed into eleven (11) groups (A, B, C, D, E, F, G, H, I, J and K), four rats in each group. Groups A, B, C and D were orally administered with 200, 400, 600 and 800 mg/kg body of leaf extract respectively, while groups E, F, G and H were given the same doses of root extract correspondingly. Group I received 1.2 mg/kg body weight of aspirin (a cardioprotective drug), while groups J and K were given distilled water. Administration lasted seven (7) consecutive days. On the seventh day, all groups, except K, were given 2.5 ml/kg body weight of carbon tetrachloride (CCl4) intraperitoneally two hours after extract/aspirin administration. Group K received olive oil. Phytochemical screening revealed the presence of alkaloids, tannins, saponins, flavonoids, anthraquinones, terpenoids and cardiac glycosides in the extracts. The activity of creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and concentration of cardiac troponin I (CTnI) in the serum of extract- and aspirin-treated groups were significantly lower (P < 0.05) than the untreated negative control in which these parameters were significantly higher (P < 0.05) than in normal control. Serum lipid profile of the animals also followed the same trend. There was a significant decrease (P < 0.05) in the concentration of malondialdehyde (MDA) in the extract- and aspirin-treated groups relative to the negative control. The activity of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) was significantly higher (P < 0.05) in the extract- and aspirin-treated groups and normal control than in the untreated negative control. The effect of the extracts were dose-dependent, and that of 800 mg/kg leaf extract was significantly higher (P<0.05) than 1.2 mg/kg aspirin. There was a significant difference (P<0.05) between the groups given leaf extract and those treated with root extract. These findings are indicative of possible cardioprotective potential of the extracts, and may be partly responsible for their efficacy against cardiovascular diseases.