High dietary iron enhances oxidative stress in liver but does not increaseaberrant crypt loci development in rats with low vitamin E status

The purpose of this study was to examine the effects of high-iron and low-v itamin E diets on lipid peroxidation and aberrant crypt foci (ACF) developm ent in rats. In a 2 x 2 x 2 factorial design, male Sprague-Dawley rats were fed 45 or 450 mg Fe/kg diet (adequate and high iron, respectively) and 15 or 100 IU vitamin E/kg diet (low and adequate vitamin E, respectively) for three weeks, when they received saline or azoxymethane (15 mg/kg for 2 wk). Diets were continued for an additional six weeks. Serum alpha-tocopherol c oncentrations in rats fed low-vitamin E diets were decreased to 30% of conc entrations observed in rats fed adequate-vitamin E diets (p < 0.0001). Also , serum alpha-tocopherol concentrations tended to be lower in rats suppleme nted with iron (p < 0.08). Lipid peroxidation in liver was significantly el evated by high-iron diets after 3 and 10 weeks of treatment, but lipid pero xidation in colonic mucosa was nor altered by dietary iron or vitamin E. Th e total number of ACF and number of large ACF (greater than or equal to 4 a berrant crypts/focus) were nor significantly altered by iron or vitamin E i ntakes. However, the size distribution of ACF was slightly altered such tha t iron-supplemented rats had 12% more ACF with two crypts per focus (p < 0. 02) than rats fed adequate-iron diets. Our data suggest that high-iron diet s enhanced oxidative stress in liver but not colon, of rats fed low-vitamin E diets. Furthermore, a high-iron diet does not increase the total number of ACF, even when vitamin E status is low.