Ethanol extract of Terminalia avicennioides root bark protects against cadmium toxicities in rats
Environmental exposure to cadmium is widespread and its toxicity has been linked with generation of reactive oxygen species. Dietary antioxidants therefore hold great promise against cadmium intoxication. We investigated the effects of ethanol extract of Terminalia avicennioidesroot bark (ERTA), a rich source of secondary metabolites, on cadmium-induced hepatotoxicity and clastogenicity in male Wistar rats. Groups of rats, five each group, were treated with either ERTA (200 or 400 mg/kg b.w), cadmium chloride (CdCl2) at 5 mg/kg b.w. or both ERTA and CdCl2. Administration of CdCl2 alone caused significantly (p<0.05) higher mean serum aspartate (AST) and alanine aminotransferases (ALT) activities, and mPCEs number in the treated rats compared to the control given distilled water. There was significant (p < 0.05) reduction in AST and ALT activities, and mPCEs in the groups given ERTA and CdCl2 compared with group given CdCl2 alone. ERTA alone at 200 mg/kg or 400 mg/kg body weight induced significant (p < 0.05) increase in mean serum alkaline phosphatase (ALP) but not AST and ALT activities, compared with the negative control. Results for histopathological analyses of liver samples of rats followed the same trends as what was obtained in the enzyme activities. In addition, CdCl2 alone produced a significantly (p<0.05) higher level of thiobarbituric acid index of lipid peroxidation compared with the negative control group which was significantly (p<0.05) reduced by ERTA treatment. ERTA therefore displayed protective properties against cadmium-induced toxicities in the male rats though there is possibility of its toxicity at the tested doses.
Keywords: Hepatotoxicity; micronucleated polychromatic erythrocytes (mPCEs); aminotransferases; cadmium chloride; clastogenicity