Use of the Ames test in assessing the relation of dietary lipid and antioxidants to N-2-fluorenylacetamide activation.

The Ames mutagenicity assay was employed to examine the effect of dietary lipid and antioxidants upon hepatic activation of N-2-fluorenylacetamide by hairless mice. Animals received diets that contained 4% and 12% corn oil and 12% hydrogenated corn oil. In addition, some animals received the respective diets with a 2% (w/w) antioxidant supplement consisting of 1.2% ascorbic acid, 0.5% butylated hydroxytoluene, 0.2% dl-alpha-tocopherol, and 0.1% reduced glutathione. No effects upon N-2-fluorenylacetamide activation, that was related to dietary lipid level or degree of saturation, were observed after 38 weeks on the experimental diets. However, significant increases in carcinogen activation were observed with microsomal fractions from animals receiving antioxidant supplements, regardless of the type or level of dietary lipid, Moreover, an effect by dietary lipid was observed when animals were treated with the carcinogen one week prior to testing. The mutagenic frequency was increased by both 4% and 12% corn oil whereas the latter level of hydrogenated corn oil produced a negligible effect. These results suggest that level of fat, degree of saturation, as well as antioxidant level, are related to hepatic capacity for carcinogen metabolism and substantiate the value of the mutagenicity assay in dietary studies.