Melatonin, a hormone secreted by the pineal gland, is known to have anti-mutagenicand oncostatic actions. This beneficial action of melatonin has been explained in terms of its abilityto scavenge free radicals and augment the activities of anti-oxidant enzymes. In the present study, weevaluated the effect of melatonin on benzo(a)pyrene-induced two stage skin carcinogenesis in mice andobserved that it can not only decrease the number of animals bearing papillomas but also the number ofpapillomas per animal both in the initiation and promotion stages of skin carcinogenesis. It was alsofound that melatonin treated animals have low levels of lipid peroxides and that it can also preventthe binding of BP or its metabolites to DNA. In view of these evidence, it can be suggested that melatoninmay function as an endogenous anti-mutagenic and oncostatic agent.

Keywords: Anticarcinogenic Agents, Benzo(a)pyrene, Croton Oil, DNA, Melatonin, Papilloma, Skin, Skin Neoplasms, Thymidine