Objectives:

In obstructive jaundice, free radical production is increased and antioxidative activity is reduced. Melatonin has a beneficial effect with antiinflammatory and antioxidant activity acting as a free radical scavenger. Melatonin inhibits the NF-?B expressions, suppresses cytokine expression/release and inhibits the adhesion molecule expressions. The aim of this study was to investigate the effects of Melatonin on liver and renal tissue NF- ?B expressions, serum and tissue lipid peroxidation in lipopolysaccharide (LPS) induced obstructive jaundice.

Methods:

We randomized 60 rats into 6 groups. Group A: Sham, Group B: Obstructive jaundice, Group C: Obstructive jaundice + Melatonin (20 mg kg-1 intraperitoneal), Group D: Obstructive jaundice+ LPS (10 mg kg-1), Group E: Obstructive jaundice + LPS + Melatonin. Group F: Obstructive jaundice + Melatonin +LPS. Biochemical markers of lipid peroxidation as Malondialdehyde(MDA) and Myeloperoxidase(MPO) were determined after sacrifice in each groups.

Results:

Serum and Liver/renal tissue MDA, MPO levels and tissues NF-?B increased in group 2, 4 and 6 compared to group 1. After the administration of Melatonin (group 3 and 5), liver/renal tissue MDA and MPO levels decreased; and tissues NF-?B levels decreased as compared to other groups.

Conclusions:

In this model of OJ stimulated by LPS, Melatonin suppressed the adverse effects of OJ in the absence of LPS. It is clearly shown that melatonin acts as a hepatic and renal protective effect against oxidative stress in OJ. However, it failed to prevent lipid peroxidation in case of LPS-induced OJ when it is administrated before or after LPS.

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