Hippocratea africana Root Extract and Fractions Attenuated Carbon Tetrachloride-Induced Oxidative Stress and Liver Injuries in Rats

Abstract

Hippocratea africana root is used locally in ethnomedicine to treat various diseases such as diabetes, malaria and poisoning. This work aimed to investigate the antidotal potential of the root extract and fractions against carbon tetrachloride induced liver injury to justify its ethnomedicinal uses and give scientific proof to its claimed antidotal activity in traditional medicine. Therefore, 40 rats were randomly divided into eight (8) groups of 5 rats each and treated as follows: Group 1- (normal control) received oral 10 mL/kg of distilled water, Group 2- served as the organotoxic group, groups 3 - 5 were orally administered with 200, 400 and 600 mg/kg of root extract respectively, groups 6 and 7 were pretreated with 400 mg/kg of DCM and aqueous fractions respectively, and group 8, the positive control group was given 100 mg/kg of silymarin. All treatment lasted 8 days, and carbon tetrachloride (1.5 mL/kg) was given to all treatment groups. Assay of liver function parameters, antioxidative stress markers as well as the histopathological study of the liver were used to assess the hepatoprotective activity of root extract and fractions. Administration of the root extract (200-600 mg/kg) caused significant (p<0.05-0.001) reductions in the levels of liver biomarker enzymes (ALT, AST, and ALP), direct and total bilirubin and elevation of serum level of total protein elevated by CCl4 administration. The effects were dose-dependent in most cases. The extract and fraction further caused significant (p<0.05-0.001) and non dose- dependent elevation in the levels of GSH, GPx, CAT, GST, and SOD when compared to the organotoxic group, while MDA level was reduced.The root extract and fractions of H. africana did not affect hematological indices of the treated rats but caused significant (p<0.001) dose-dependent increases of WBC and platelets counts at the highest dose (600 mg/kg) relative to the organotoxic group. Histology of the liver sections of extract, fractions, and silymarin-pretreated animals showed insignificant reductions in the pathological features compared to the organotoxic-treated animals except at the lowest dose (200 mg/kg). The chemical pathological improvements observed were not reflected markedly in histopathological observations, suggesting weak hepatoprotective potentials. The results showed that root extract and fractions of Hippocratea africana have weak hepatoprotective potentials against CCl4-induced liver toxicities, which may be due to the activities of its phytochemical components and short duration of study.