CHEMOPREVENTIVE ACTION OF SELENIUM ON METHYLCHOLANTHRENE-INDUCED CARCINOGENESIS IN THE UTERINE CERVIX OF MOUSE

The placement of cotton thread impregnated with beeswax containing methylcholanthrene (MCA, approximately 600-mu-g) inside the canal of the uterine cervix of virgin, adult mice results in the emergence of precancerous and cancerous lesions in the cervical epithelium. Employing this experimental carcinogenesis model system, the present study evaluates the chemopreventive action of selenium on the incidences of precancerous and cancerous lesions in the cervical epithelium. When selenium was administered through drinking water at the dose level of 1 ppm for 1 week before and 12 weeks following carcinogen thread insertion, the cervical carcinoma incidence, as compared to that in control mice (72%), was 37%. This decline in the incidence of carcinoma was significant (p < 0.05). The incidences of hyperplasia and dysplasia show a decreasing trend with selenium treatment in MCA-thread-inserted animals.