Assessment of DNA damage and repair in adults consuming allyl isothiocyanate or Brassica vegetables

Allyl isothiocyanate (AITC) is a dietary component with possible anticancer effects, though much information about AITC and cancer has been obtained from cell studies. To investigate the effect of AITC on DNA integrity in vivo, a crossover study was conducted. Adults (n=46) consumed AITC, AITC-rich vegetables [mustard and cabbage (M/C)] or a control treatment with a controlled diet for 10 days each. On day 11, volunteers provided blood and urine before and after consuming treatments. Volunteers were characterized for genotype for GSTM1 and GSTT1 (glutathione S-transferases) and XPD (DNA repair). DNA integrity in peripheral blood mononuclear cells was assessed by single-cell gel electrophoresis. Urine was analyzed for 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and creatinine. Ten-day intake of neither AITC nor M/C resulted in statistically significant differences in DNA strand breaks [least squares mean (LSmean) % DNA in tail +/- S.E.M.: 4.8 +/- 0.6 for control, 5.7 +/- 0.7 for AITC, 5.3 +/- 0.6 for M/C] or urinary 8-oxodG (LSmean mu g 8-oxodG/g creatinine S.E.M.: 2.95 +/- 0.09 for control, 2.88 +/- 0.09 for AITC, 3.06+0.09 for M/C). Both AITC and M/C increased DNA strand breaks 3 h postconsumption (LSmean % DNA in tail +/- S.E.M.: 3.2 +/- 0.7 for control, 8.3 +/- 1.7 for AITC, 8.0 +/- 1.7 for M/C), and this difference disappeared at 6 h (4.2 +/- 0.9 for control, 5.7 +/- 1.2 for AITC, 5.5 +/- 1.2 for M/C). Genotypes for GSTM1, GSTF1 and XPD were not associated with treatment effects. In summary, DNA damage appeared to be induced in the short term by AITC and AITC-rich products, but that damage disappeared quickly, and neither AITC nor AITC-rich products affected DNA base excision repair. (C) Published by Elsevier Inc.