| ABSTRACT: |
|
The design of the present study was based on the premise that if
blocking agents and suppressing agents are targeted at different phases of
chemical carcinogenesis, a greater chemopreventive effect would be
achieved by using the combination treatment compared to the single-agent
treatment. The dimethylbenz[a]anthracene (DMBA)-induced mammary tumor
model in rats was used to test this hypothesis, with the blocking agent
given before DMBA only and the blocking agent given after DMBA until the
end of the experiment. A total of three sets of combination treatment were
carried out; diallyl sulfide/Se-methylselenocysteine, ellagic
acid/selenomethionine, and diallyl sulfide/quercetin. In all three cases,
the combination regimen was much more effective than the single-agent
treatment in tumor suppression. It should be noted that only naturally
occurring inhibitors were selected for these experiments. The impact of
minor dietary anutrients in cancer chemoprevention is also
discussed. |