Antioxidant and Hepatoprotective Activity of Methanolic Extract of Cassia sieberiana Leaves in Carbon Tetrachloride-induced Hepatotoxicity in Rats

摘要

Aims: The study was aimed at evaluating the hepatoprotective and antioxidant activity of the methanolic extract of C. sieberiana leaves. Study Design: Hepatoprotective , in vitro and in vivo antioxidant activity. Place and Duration of Study: Department of Veterinary Physiology, Pharmacology, Biochemistry and Animal Health and Production, College of Veterinary Medicine, Micheal Okpara University of Agriculture, Umudike, Umuahia, Abia State, June 2014. Methodology: Cassia sieberiana leaves were extracted with 80% methanol for 48 h using cold maceration method. The hepatoprotective activity of C. sieberiana extract (100, 200 and 400 mg/kg) and silymarin (100 mg/kg) was evaluated using carbon tetrachloride (CCl₄) induced hepatotoxicity in albino rats. The antioxidant activity was determined using both in vitro (2, 2-diphenyl-1-picrylhydrazyl photometric assay) and in vivo (malondialdehyde and catalase level assay) models. Results: The extraction of the C. sieberiana leaves for 48 h using cold maceration method yielded 9.5% w/w of dark green and pasty extract. The phytochemical spot test of the CSE showed the presence of saponins, alkaloids, flavonoids, terpene/sterol, glycosides and tannins. The extract (100, 200 and 400 mg/kg) and silymarin (100 mg/kg) produced a significant (p < 0.05) dose-dependent increase in alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphate levels in serum of treated rats, when compared with the negative control group. The extract (25 – 400 μg/ml concentration) produced a concentration-dependent increase in antioxidant activity in 2, 2-diphenyl-1-picrylhydrazyl (DPPH) photometric assay. The IC50 of the extract in DPPH photometric assay was 50 μg/ml concentrations. The extract and silymarin showed a significant (p<0.05) dose-dependent increase in catalase level in treated rats, when compared with the negative control group. Also, the extract (400 mg/kg) and silymarin (100 mg/kg) produced a significant (p<0.05) decrease in malondialdehyde level in treated rats, when compared with the negative control group. Conclusion: This study demonstrates that C. sieberiana leaves have a potent hepatoprotective and antioxidant activities. It justified the use of C. sieberiana leaves in the treatment of liver injury related disease in folk medicine.