CHEMOPREVENTION OF MAMMARY-CANCER BY DIALLYL SELENIDE, A NOVEL ORGANOSELENIUM COMPOUND

Previous research has demonstrated that structurally distinctive organ oselenium compounds are superior to the corresponding sulfur analogs i n cancer, prevention. The present study was designed to extend this ob servation to diallyl selenide (DASe), a volatile synthetic compound an d diallyl sulfide (DAS), a flavor component of garlic. Their anticarci nogenic activities were evaluated using the 7,12-dimethylbenz(a)-anthr acene (DMBA)-induced mammary tumor model. Rats were gavaged thr ee tim es with DASe (6 or 12 mu mol/kg body wt) or DAS (300, 900 or, 1,800 mu mol/kg) at 96, 48 and 24 hours before DMBA treatment. Significant tum or inhibition was found with the two closes of DASe and the highest do se of DAS. Based on these results, DASe appears to be at least 300 tim es more active than DAS. Analysis of total DMBA-DNA binding and indivi dual DNA adducts in the mammary gland and liver showed that DASe had n o effect on these parameters, suggesting that DASe might influence som e unknown risk-associated events other than carcinogen activation/deto xification. Although the mechanism of action of DASe remains to be elu cidated its potential relevance to natural products will be discussed in the context of the chemistry of selenium-enriched garlic which has been reported to be effective in cancer protection in several studies.