DIETARY ROSEMARY SUPPRESSES 7,12-DIMETHYLBENZ(A)ANTHRACENE BINDING TORAT MAMMARY CELL-DNA

Commercially available ground rosemary powder was examined for its abi lity to modify the in vivo binding of 7,12-dimethylbenz(a)anthracene ( DMBA) metabolites to mammary cell DNA in 55-d-old rats fed diets conta ining varying quantities and types of lipids. Supplementing a casein-b ased diet containing 20% corn oil with 1% rosemary for 2 wk reduced by 76% the occurrence of DMBA-induced DNA adducts occurring 24 h after t reatment with 50 mg DMBA/kg body weight. A comparable reduction in DNA adducts (66%) occurred when 0.5% rosemary was added to a diet contain ing 20% corn oil, and the quantity of DMBA given was reduced to 25 mg/ kg body weight. The reduction in the occurrence of adducts occurring 2 4 h after DMBA treatment caused by 0.5% dietary rosemary was greater ( P < 0.05) when added to a diet containing 20% corn oil than when added to a diet containing 5% corn oil and 15% coconut oil. Rosemary, 1% bu t not 0.5%, reduced DMBA-induced DNA adducts when the diet contained 5 % corn oil. These studies demonstrate that rosemary is effective in re ducing the binding of DMBA metabolites to rat mammary cell DNA. Furthe rmore, the present studies demonstrate that the benefits of rosemary a re dependent on the source and concentration of dietary lipids.