DNA protective effects of Brussels sprouts: Results of a human intervention study

B67 To find out if the cancer protective effects of Brussels sprouts seen in epidemiological studies are due to protection against DNA-damage, an intervention trial was conducted in which the impact of vegetable consumption on DNA-stability was monitored in lymphocytes with single cell gel electrophoresis (SCGE) assays. After consumption of the sprouts (300g/P/d, n=8), a reduction of DNA-migration (97%) induced by the heterocyclic aromatic amine 2-amino-1-methyl-6-phenyl-imidazo-[4,5-b]pyridine (PhIP) was observed, whereas no protective effect was seen with 3-amino-1-methyl-5H-pyrido[4,3-b]-indole (Trp-P-2). The protection may be due to inhibition of sulfotransferase (SULT) 1A1, which plays a key role in the activation of PhIP. In addition, DNA-damage caused by hydrogen peroxide was significantly (39%) lower after the intervention and a strong decrease of the endogenous formation of oxidised DNA bases was observed in experiments with lesion specific enzymes (ENDO III and FPG). These antioxidant effects could not be explained by induction of antioxidant enzymes (glutathione peroxidase and superoxide dismutase). Serum vitamin C levels were increased by 37% after sprout consumption but no correlations were seen between prevention of DNA-damage and individual alterations of the vitamin levels. In vitro experiments indicate that sprouts contain compounds which act as direct reactive oxygen species (ROS) scavengers and it is likely that these compounds are involved in the strong effects seen in the intervention trial. Our study shows for the first time that sprout consumption leads to inhibition of SULTs in humans and to protection against PhIP and oxidative DNA-damage. Since SULTs are involved in the activation of a number of genotoxic carcinogens their inhibition by dietary factors may be a novel new mechanism of cancer chemoprevention.