Assessment of the activity of provitamin A against hepatocarcinogenesis in rats

ABSTRACT

The present work was performed to study the influence of chemoprotective and preventive activity of dietary carrot which was consumed daily on hepatocarcinogenesis induced by Dibutylnitrosamine [DBN] in male albino rats. Sixty six adult male albino rats [Sprague Dawley Strain] were randomly allocated in groups of eleven rats fed continuously for 60 days on six diets. The first three groups were served as control and put on the following diets throughout the experimental period, [GI] commercial diet; [G2] commercial diet with 50g of fresh carrot daily; [G3] commercial diet and treated with Dibutylnitrosamine [DBN] in drinking water as hepatocarcinogenie agent. The other experimental groups were fed on commercial diet +50g of fresh carrot, 30 days before [G4] or after treatment with DBN [G5] respectively, while G6 received commercial diet +50 g of fresh carrot daily and treated at the same time with DBN throughout the experimental period, 60 days. Fasting blood samples were taken on the day 60 for the determination of antioxidative state by measuring reduced glutathione [GSH]; complete blood picture [CBC] and blood indices; serum and liver malondialdehydc [lipid peroxidations marker]; liver GSH; serum AST, ALT, ALP, LDH, GOT, total and direct bilirubin; serum total protein and albumin; and pathologic evaluations were made. Fresh carrot administration revealed a protective and preventive effects on the rats hepatocyte treated with DBN which was reflected by the significant reduction in the liver function tests [AST, ALT, ALP, GOT, LDH and total bilirubin], while no significant improvement in either total protein or albumin could be detected. This reduction is ordered among the different treated groups as following G5, G6 and G4. The oxidative state was determined by measuring liver and whole blood GSH, exhibiting significant increase in blood GSH in contrast to significant reduction in liver GSH. While liver and serum MDA concentration as lipid peroxidation index, showed significant reduction in serum and liver MDA. Histopathologically, liver of rats fed carrot before, during or after hepatocarcinogensis, showed highly improvement on preneoplastic lesions, less fibrosis and oval cells development than positive control, but in different degree of lesions. It was concluded that, carrot consumption was very effective in preventing hepatocarcinogensis, when it is administrated daily after short exposure to hepatocarcinogen, while before or during the earcinogenesis carrot intake may have mild improvement effect on hepatocarcinogenesis which was revealed by decrease in the severity of illness