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 signifi cantly 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-dose 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 signifi cantly lower in the high-dose corticosteroid group as compared to the low-dose group. Thus, low-dose corticosteroid provides asignifi cant reduction of liver damage without increased side effects, while high dose is associated not with lower fi brosis but with increased side effects.