Preclinical and clinical evaluation of sulforaphane for chemoprevention in the breast.
Consumers of higher levels of Brassica vegetables, particularly those of the genus Brassica (broccoli, Brussels sprouts and cabbage), reduce their susceptibility to cancer at a variety of organ sites. Brassica vegetables contain high concentrations of glucosinolates that can be hydrolyzed by the plant enzyme, myrosinase, or intestinal microflora to isothiocyanates, potent inducers of cytoprotective enzymes and inhibitors of carcinogenesis. Oral administration of either the isothiocyanate, sulforaphane, or its glucosinolate precursor, glucoraphanin, inhibits mammary carcinogenesis in rats treated with 7,12-dimethylbenz[a]anthracene. In this study, we sought to determine whether sulforaphane exerts a direct chemopreventive action on animal and human mammary tissue. The pharmacokinetics and pharmacodynamics of a single 150 mumol oral dose of sulforaphane were evaluated in the rat mammary gland. We detected sulforaphane metabolites at concentrations known to alter gene expression in cell culture. Elevated cytoprotective NAD(P)H:quinone oxidoreductase (NQO1) and heme oxygenase-1 (HO-1) gene transcripts were measured using quantitative real-time polymerase chain reaction. An observed 3-fold increase in NQO1 enzymatic activity, as well as 4-fold elevated immunostaining of HO-1 in rat mammary epithelium, provides strong evidence of a pronounced pharmacodynamic action of sulforaphane. In a subsequent pilot study, eight healthy women undergoing reduction mammoplasty were given a single dose of a broccoli sprout preparation containing 200 mumol of sulforaphane. Following oral dosing, sulforaphane metabolites were readily measurable in human breast tissue enriched for epithelial cells. These findings provide a strong rationale for evaluating the protective effects of a broccoli sprout preparation in clinical trials of women at risk for breast cancer.
Cornblatt
Brian S
BS
Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA.
Ye
Lingxiang
L
Dinkova-Kostova
Albena T
AT
Erb
Melanie
M
Fahey
Jed W
JW
Singh
Navin K
NK
Chen
Min-Shue A
MS
Stierer
Tracey
T
Garrett-Mayer
Elizabeth
E
Argani
Pedram
P
Davidson
Nancy E
NE
Talalay
Paul
P
Kensler
Thomas W
TW
Visvanathan
Kala
K
D000818:Animals; D016588:Anticarcinogenic Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D001937:Brassica / Q000737:chemistry*; D005260:Female; D051547:Heme Oxygenase-1 / Q000378:metabolism; D006801:Humans; D017879:Isothiocyanates; D008321:Mammary Glands, Animal / Q000201:enzymology / Q000378:metabolism*; D042361:Mammary Glands, Human / Q000201:enzymology / Q000378:metabolism*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D010865:Pilot Projects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013454:Sulfoxides; D013861:Thiocyanates / Q000493:pharmacokinetics / Q000494:pharmacology*; D014018:Tissue Distribution
D016588:Anticarcinogenic Agents; D015415:Biomarkers; D017879:Isothiocyanates; D013454:Sulfoxides; D013861:Thiocyanates; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human; C016766:sulforaphane