Acute liver injury (ALI) is defined as a clinical condition that results from severe and extensive damage of liver cells, accompanied with jaundice and increase in total bilirubin, alanin aminotransferase and alkaline phosphatase levels that may lead to failure of the liver to function normally and consequently induce mental confusion of various degrees.This study was performed to explore the hepatoprotective effect of some drugs with antioxidant activity including vitamin- A, N-acetylcystein, vasodilator (Nitroglycerin), calcium channel blocker (Nifedipine), xanthine oxidase inhibitor (Allopurinol), B-blocker (Metoprolol), and some medicinal plants (Apium Graveolens and Cinnamomum verum). Fifty four local domestic rabbits were used in the present study; they were divided into 9 groups(six rabbit in each group). One group was used as the control in which carbon tetrachloride (CCl4) in a dose of 1 ml/kg was given intraperitonially to induce acute liver injury. The other eight groups were treated 1 hour before induction of ALI with one of the above mentioned agents for each group. Liver function was assessed by measuring serum alanin aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total serum billirubin (T.S.B.) and total serum protein (T.S.P.) on three occasions: 24 hours, 72 hours and 120 hours after induction of ALI with CCl4. The results were compared with the normal values and that of the control to determine the hepatoprotective effect of the tested agents; also the results for each drug were compared at different occasions. Histopathological examination of the liver sections of each group was done at the end of the study to show the degree of improvement in comparison with the control group. Rabbits were pretreated one hour before administration of CCl4 with a daily single oral dose of one of these agents, vitamin-A (8500 IU/kg), N-acetylcysteine (275 mg/kg), nitroglycerin (1mg/kg), nifedipine (2mg/kg), allopurinol (100mg/kg) and metoprolol (7mg/kg). All these tested drugs continued at the same dose for five successive days after the induction of ALI. Some of these agents showed a significant lowering effect in the liver enzymes' levels of (ALT, AST and ALP) as well as reduction in the level of (T.S.B.) and significant elevation in the level of (T.S.P). Also some of these tested drugs produced a clear improvement in histopathological changes of the liver tissue. Pretreatment with aqueous extract of Apium Graveolens (celery) (400 mg/kg/day) and Cinnamomum verum (cinnamon) (15mg/kg/day) were given orally in a single daily dose and continued for five successive days after induction of ALI, resulted in a significant decrease in the levels of ALT, AST, ALP and T.S.B. with increase in the level of T.S.P. by cinnamon extract but not with celery extract.
Histopathological examination of the liver samples of treated groups also revealed an improvement. As a conclusion, the results of the effect of the previously mentioned drugs and medicinal plants had shown a hepatoprotective effect at the tested doses by restoring some of the normal hepatic functions and this may be related to their antioxidant effect against the oxidative stress produced by CCl4. It is recommended to study the safe antioxidant drugs and medicinal plants for patients with acute or chronic liver injury.
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