Effects of lycopene on spontaneous mammary tumour development in SHN virgin mice

Effects of the chronic ingestion of lycopene, a caroteniod from tomato, on the development of spontaneous mammary tumours were examined in a high mammary tumor strain of SHN virgin mice. Beginning at 40 days of age, the control and the experimental groups were allowed free access to an AIN-76TM diet and diet supplemented further with lycopene at the concentration of 5.0 x 10^-5%, respectively. The treatment significantly suppressed the mammary tumor development, which suppression was associated with the decrease in the mammary gland activity of thymidylate synthetase, and serum levels of free fatty acid an prolactin. Body weight was little affected and no deleterious side-effects of lycopene were detected. All results show that lycopene could be promising as a chemopreventive agent for mammary and other types of tumors.