Abstract

The aim of this study was to investigate the effect of Piper nigrum L. root extracts on carbon tetrachloride (CCl₄)-induced rat liver injury. Among the three different extracts (water, ethanol and chloroform extract), ethanol extract exhibits the highest hepatoprotective activity (p < 0.05). When using the ethanol extract at a dose of 120 mg/ kg to treat the CCl₄-intoxicated rat, the activities of alanine transaminase (ALT) and aspartate transanimase (AST) in rat serum decreased to 65.7 and 84.5%, respectively. At the same time, the lipid peroxidation (MDA) decreased to 52.3% and glutathione (GSH) increased to 55.8% in the rats liver homogenate, as compared with those of the CCl₄ positive control rats. The hepatoprotective effect of ethanol extract was also supported by the histopathological observations. Moreover, the ethanol extract was studied for its in vitro antioxidant activity using the methods of ferric thiocyanate (FTC) and thiobarbituric acid (TBA). The findings indicate that the ethanol extract of P. nigrum L. root is an efficient hepatoprotective and antioxidant agent against CCl₄-induced liver injury.

Key words: Piper nigrum L. root, ethanol extract, carbon tetrachloride (CCl₄)_,hepatoprotective, antioxidant.

Abbreviation

Abbreviations: FTC, Ferric thiocyanate; TBA, thiobarbituric acid; GSH, reduced glutathione; MDA,  malondialdehyde; ALT, alanine aminotransferase; AST,aminotransferase; CCl₄, carbon tetrachloride; Vit C, vitamin C; vit E, vitamin E;WE, water extract; EE6, 60% ethanol extract; CE, chloroform extract of dried and powdered root of P. nigrum L.