Abstract:
Ethnopharmacoiogical relevance: The leaf extract of Terminalia brownii Fresen
(Combretaceae) is used for treatment of liver diseases in Ethiopia but so far there is no scientific report on the hepatoprotective and antioxidant activities of the plant. The main aim of the present study was, therefore, to evaluate the hepatoprotective and antioxidant activities of the leaf extract of the plant. Methodology: The plant was collected from Northwest Ethiopia in August 2011 and authenticated. The dried and powdered leaves of the plant were extracted by maceration using 80% methanol and the hepatoprotective and antioxidant activity of the extract was evaluated in a rat model with a liver injury induced by intraperitonea I (ip) administration of 0.2 ml/ / 100 g, b.vv of carbon tetrachloride (20% in olive oil) every 72 h for twenty one days. The antioxidant activity of the extract was also evaluated in vitro on the basis of its ability to scavenge the stable l.l-diphenyl-2-picrylhyorazyl (DPPH) radical. Results: Administration of CCL significantly (p < 0.001) increased the plasma levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) while reducing endogenous antioxidant enzymes, catalase (CAT) and superoxide disniutase (SOD) in the toxin
group compared with the values in the control group. Pretreatment of the rats with 250 mg/kg and 500 mg/kg of the 80% methanolic leaf extract of T. brownii and standard drug, sylimarin (100 mg/kg) reduced plasma transaminases level, significantly (p < 0.05 to p < 0.001) while increasing CAT and SOD. The serum marker result was further supported by histopathological examination of the liver that showed improved architecture and reduction of necrosis compared with the finding in the toxic group. The extract also showed potent DPPH scavenging activity with lCs0 of 5.9 pg/ml. Preliminary phytochemical screening of the plant showed the presence of polyphenols, flavonoids, tannins, saponins, and phytosterols. The oral acute toxicity study did not show any sign of morbidity and mortality up to a dose of 2 g/kg. Conclusion: The results of the present study revealed the hepatoprotective and antioxidant activities of the leaf extract of T. brownii that scientifically validates its use in the traditional medicine and its potential for the treatment of liver disorders.
