Dose-related effects of dexamethasone on liver damage due to bile duct ligation in rats

AIM: To evaluate the effects of dexamethasone on liver damage in rats with bile duct ligation. METHODS: A total of 40 male Sprague-Dawley rats, weighing 165-205 g, were used in this study. Group 1 (sham-control, n = 10) rats underwent laparotomy alone and the bile duct,was just dissected from the surrounding tissue. Group 2 rats (untreated, n = 10) were subjected to bile duct ligation (BDL) and no drug was applied. Group 3 rats (low-dose dexa, n = 10) received a daily dose of dexamethasone by orogastric tube for 14 d after BDL. Group 4 rats (high-dose dexa, n = 10) received a daily dose of dexamethasone by orogastric tube for 14 d after BDL. At the end of the two-week period, biochemical and histological evaluations were processed. RESULTS: The mean serum bilirubin and liver enzyme levels significantly decreased, and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) values were significantly increased in low-dose dexa and high-dose dexa groups when compared to the untreated group. The histopathological score was significantly less in the low-close and high-dose dexa groups compared to the untreated rats. In the low-dose dexa group, moderate liver damage was seen, while mild liver damage was observed in the high-dose dexa group. CONCLUSION: Corticosteroids reduced liver damage produced by bile duct obstruction. However, the histopathological score was not significantly lower in the high-dose corticosteroid group as compared to the low-dose group. Thus, low-dose corticosteroid provides a significant reduction of liver damage without increased side effects, while high dose is associated not with lower fibrosis but with increased side effects. (c) 2006 The WJG Press. All rights reserved.