Antioxidant and anti-inflammatory action of melatonin in an experimental model of secondary biliary cirrhosis induced by bile duct ligation

AIM: To evaluate the effects of melatonin (Mel) on oxidative stress in an experimental model of bile duct ligation (BDL). METHODS: Male Wistar rats (n = 32, weight ± 300 g) were allocated across four groups: CO (sham BDL), BDL (BDL surgery), CO + Mel (sham BDL and Mel administration) and BDL + Mel (BDL surgery and Mel administration). Mel was administered intraperitoneally for 2 wk, starting on postoperative day 15, at a dose of 20 mg/kg. RESULTS: Mel was effective at the different standards, reestablishing normal liver enzyme levels, reducing the hepatosomatic and splenosomatic indices, restoring lipoperoxidation and antioxidant enzyme concentrations, reducing fibrosis and inflammation, and thereby reducing liver tissue injury in the treated animals. CONCLUSION: The results of this study suggest a protective effect of Mel when administered to rats with secondary biliary cirrhosis induced by BDL.