ABSTRACT
The aim of the study was to evaluate the hepatoprotective effect of aqueous extract of bitter kola (garcinia kola) seeds on carbon tetrachloride (CCl4) induced liver damage in adult wistar rats. The experimental animals (36 male and female) weighing between 150-250g were randomly divided into six groups. Each group comprised of 6 rats and was labeled as groups I, II, III, IV, V and VI. Group I (control) animals were administered distilled water orally daily for 2 weeks (volume per body weight) while group II (CCl4 control) animals were administered distilled water orally daily for 2 weeks (volume per body weight) and carbon tetrachloride (CCl4) 0.4 m1/kg intraperitonially as a single application. Group III rats were administered 100 mg of silymarin / kg body weight once daily for 2 weeks followed by a single dose of CCl4 (0.4 m1) on day 14 of the experiment. Group IV rats were administered 800 mg aqueous extract bitter kola (Garcinia kola) / kg body weight orally once daily for 2 weeks. Group V and VI rats were administered 800 mg and 400 mg aqueous extract bitter kola (Garcinia kola) seed) orally once daily for 2 weeks followed by a single dose of CCl4 (0.4 m1) on day 14 respectively. At the end of the experiment, blood samples were a collected for serum analysis of levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), superoxide dismutase (SOD), reduced glutathione (GSH) and catalase (CAT). Hepatic tissues were also collected for histopathological assessment of liver damage. Results obtained showed that the CCl4 treated group caused significant increase in the levels of liver enzymes (AST, ALP and ALT). Bitter kola (Garcinia kola) seed aqueous extract caused significant decrease in the aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) levels in the serum of the extract treated groups. Histopathological and histochemical examinations of liver sections revealed distortion of histoarchitecture of the liver tissue, such as, sinusoidal congestion, necrosis, steatosis and fibrosis was observed in group II. The administration of aqueous extract of bitter kola (Garcinia kola) seed remarkably inhibited histoarchitectural distortion induced by CCl4 administration. Hepatoprotective activity of the extract at dose of 400mg/kg was comparable to the reference drug. Garcinia kola aqueous seed extract showed a remarkable hepatoprotective and antioxidant activity against CCl4-induced hepatotoxicity as observed from the serum marker enzymes and antioxidant levels in liver tissues. CCl4-induced a significant rise in AST, ALT, ALP with a reduction of superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH). Treatment of the rats with the extract significantly (p<0.05) altered serum marker enzymes and antioxidant levels to near normal compared with CCl4-treated rats (group II). The activity of the extract at dose of 400mg/kg (group VI) was comparable to the standard drug confirmed by histopathological examinations of liver sections. Results indicated that Garcinia kola aqueous seed extract has hepatoprotective and antioxidant properties against CCl4-induced hepatotoxicity in Wistar rats.