IMPACT OF VARIOUS SOURCES OF GARLIC AND THEIR CONSTITUENTS ON 7,12-DIMETHYLBENZ[A]ANTHRACENE BINDING TO MAMMARY CELL-DNA

The present studies assessed the impact of various sources of garlic a nd their constituents (water- and ethanol-extracts and S-allylcysteine ) on the in vivo binding of the carcinogen 7,12-dimethylbenz[a]anthrac ene (DMBA) to rat mammary cell DNA. The provision of dietary raw garli c powder (2%) or its water-extract (1.5%) reduced DMBA-DNA binding by 33 and 46% respectively. Dietary supplementation with a commercially a vailable deodorized garlic powder (powder A) at 2 or 4% depressed the occurrence of adducts by 50 and 78% respectively, while providing a co mmercially available high sulfur garlic preparation (powder B) at 2% r educed binding by 56%. A pair-feeding study revealed that the depressi on in carcinogen binding was independent of food intake or weight gain . Although 1% raw garlic powder did not significantly influence the oc currence of DMBA-DNA adducts, an equivalent as the water-extract (0.75 %), the ethanol-extract (0.015%) or commercially available powders (A and B) reduced DMBA adducts in mammary tissue by 44, 25, 71 and 65% re spectively. Dietary fortification with S-allylcysteine (SAC), a water- soluble constituent of processed garlic, caused a progressive decrease in the binding of DMBA to DNA. Studies with SAC suggest the primary e ffect of garlic and its constituents is on the bioactivation and bindi ng of the carcinogen rather than DNA repair. These data reveal that se veral forms of garlic are effective, although variable, in altering ca rcinogen bioactivation and presumably chemically induced carcinogenesi s.