title: Effects of glucosinolate-rich broccoli sprouts on urinary levels of aflatoxin-DNA adducts and phenanthrene tetraols in a randomized clinical trial in He Zuo township, Qidong, People's Republic of China.
abstract: Residents of Qidong, People's Republic of China, are at high risk for development of hepatocellular carcinoma, in part due to consumption of aflatoxin-contaminated foods, and are exposed to high levels of phenanthrene, a sentinel of hydrocarbon air toxics. Cruciferous vegetables, such as broccoli, contain anticarcinogens. Glucoraphanin, the principal glucosinolate in broccoli sprouts, can be hydrolyzed by gut microflora to sulforaphane, a potent inducer of carcinogen detoxication enzymes. In a randomized, placebo-controlled chemoprevention trial, we tested whether drinking hot water infusions of 3-day-old broccoli sprouts, containing defined concentrations of glucosinolates, could alter the disposition of aflatoxin and phenanthrene. Two hundred healthy adults drank infusions containing either 400 or < 3 micromol glucoraphanin nightly for 2 weeks. Adherence to the study protocol was outstanding; no problems with safety or tolerance were noted. Urinary levels of aflatoxin-N(7)-guanine were not different between the two intervention arms (P = 0.68). However, measurement of urinary levels of dithiocarbamates (sulforaphane metabolites) indicated striking interindividual differences in bioavailability. An inverse association was observed for excretion of dithiocarbamates and aflatoxin-DNA adducts (P = 0.002; R = 0.31) in individuals receiving broccoli sprout glucosinolates. Moreover, trans, anti-phenanthrene tetraol, a metabolite of the combustion product phenanthrene, was detected in urine of all participants and showed a robust inverse association with dithiocarbamate levels (P = 0.0001; R = 0.39), although again no overall difference between intervention arms was observed (P = 0.29). Understanding factors influencing glucosinolate hydrolysis and bioavailability will be required for optimal use of broccoli sprouts in human interventions.
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Room E7541, 615 North Wolfe Street, Baltimore, MD 21205, USA. tkensler@jhsph.edu
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kensler
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Chen
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Egner
authors.forename: Jed W
authors.initials: JW
authors.lastname: Fahey
authors.forename: Lisa P
authors.initials: LP
authors.lastname: Jacobson
authors.forename: Katherine K
authors.initials: KK
authors.lastname: Stephenson
authors.forename: Lingxiang
authors.initials: L
authors.lastname: Ye
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Coady
authors.forename: Jin-Bing
authors.initials: JB
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Qi-Nan
authors.initials: QN
authors.lastname: Zhang
authors.forename: Bao-Chu
authors.initials: BC
authors.lastname: Zhang
authors.forename: Yuan-Rong
authors.initials: YR
authors.lastname: Zhu
authors.forename: Geng-Sun
authors.initials: GS
authors.lastname: Qian
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Carmella
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Hecht
authors.forename: Lorie
authors.initials: L
authors.lastname: Benning
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Gange
authors.forename: John D
authors.initials: JD
authors.lastname: Groopman
authors.forename: Paul
authors.initials: P
authors.lastname: Talalay
mesh_terms: D000328:Adult; D000348:Aflatoxins / Q000378:metabolism / Q000652:urine*; D000368:Aged; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D001628:Beverages; D001682:Biological Availability; D001937:Brassica / Q000737:chemistry*; D006528:Carcinoma, Hepatocellular / Q000209:etiology / Q000517:prevention & control; D018736:DNA Adducts / Q000652:urine*; D005260:Female; D005961:Glucosinolates / Q000494:pharmacology*; D006801:Humans; D006868:Hydrolysis; D008113:Liver Neoplasms / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010616:Phenanthrenes / Q000652:urine*; D010919:Placebos
chemical_list: D000348:Aflatoxins; D016588:Anticarcinogenic Agents; D018736:DNA Adducts; D005961:Glucosinolates; D010616:Phenanthrenes; D010919:Placebos