Abstract
We previously showed rats fed with apiaceous vegetables, but not with their putative chemopreventive phytochemicals, reduced colonic DNA adducts formed by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a dietary procarcinogen. We report here the effects of feeding apiaceous and cruciferous vegetables versus their purified predominant phytochemicals, either alone or combined, on prostate and pancreatic PhIP-DNA adduct formation. In experiment I, male Wistar rats received three supplemented diets: CRU (cruciferous vegetables), API (apiaceous vegetables), and CRU+API (both types of vegetables). In experiment II, rats received three diets supplemented with phytochemicals matched to their levels in the vegetables from experiment I: P + I (phenethyl isothiocyanate and indole-3-carbinol), FC (furanocoumarins; 5-methoxypsoralen, 8-methoxypsoralen, and isopimpinellin), and COMBO (P + I and FC combined). After 6 days of feeding, PhIP was injected (10 mg/kg body weight) and animals were killed on day 7. PhIP-DNA adducts were analyzed by LC-MS/MS. In prostate, PhIP-DNA adducts were reduced by API (33%, P < .05), P + I (45%, P < .001), and COMBO (30%, P < .01). There were no effects observed in pancreas. Our results suggest that fresh vegetables and purified phytochemicals lower PhIP-DNA adducts and may influence cancer risk.