Effect of melatonin on antioxidant status and circadian activity rhythm during hepatocarcinogenesis in mice

AIM: Alteration of circadian systems can cause cancer and affects its development and response to therapeutics. The present study investigates whether cancer can disrupt circadian locomotor rhythms and evaluated the influence of melatonin (MLT) and oxaliplatin on the levels of antioxidants and circadian locomotor activity rhythms in N-nitrosodiethylamine (NDEA)-induced liver tumor in Indian field mouse (Mus booduga). MATERIALS AND METHODS: Effects of NDEA, NDEA, and MLT, as well as NDEA and oxaliplatin, on levels of mice liver marker enzymes and antioxidants and their circadian locomotor activity rhythm were assessed. RESULTS: Treatment of mice with NDEA caused significant alteration of their liver marker enzymes [aspartate transaminase and alanine transaminase; P<0.05 Duncan's multiple range test (DMRT) test] antioxidant levels (superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase; P<0.05, DMRT test] and circadian locomotor activity rhythm, which were abrogated when the animals were also given MLT or the anticancer drug, oxaliplatin. CONCLUSION: Our study demonstrated that the circadian clock was disturbed by hepatocarcinogenesis and the effects could be reversed by the chronobiotic, MLT.