Broccoli Sprout Extracts Inhibit Bladder Cancer Cell Proliferation

Broccoli sprout extracts inhibit bladder cancer cell proliferation

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana

Session 54G, Nutraceutical & Functional Foods: General II
R. A. ROSSELOT1, S. K. Clinton2, S. J. Schwartz1, and Q. Tian3. (1) Dept. of Food Science and Technology, The Ohio State Univ., 2015 Fyffe Road, Columbus, OH 43210, (2) Dept. of Internal Medicine, Ohio State Univ., Division of Hematology and Oncology, 320 W. 10th Ave., A-437 Starling-Loving Hall, Columbus, OH 43210, (3) Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007

Epidemiologic findings support the hypothesis that cruciferous vegetable consumption is associated with lower bladder cancer risk. Our objective is to identify components of cruciferous vegetables that may influence bladder carcinogenesis and define their mechanisms of action. We first examined glucosinolates, a class of phytochemicals abundant in cruciferous vegetables that are enzymatically converted to isothiocyanates during chopping, chewing, and digestion. The glucosinolate-rich fraction was extracted from commercially available broccoli sprouts and quantified using liquid chromatography coupled to electrospray ionization tandem mass spectrometry. We were able to detect and quantify ten individual glucosinolates in broccoli sprouts. The glucosinolates were enzymatically converted with myrosinase to corresponding isothiocyanates. 0, 1, 3, 6, 15, 30, 45, 70, and 100 µM of the total combined glucosinolates in the extract and the corresponding isothiocyanates (produced from 0, 1, 3, 10, 13, 17, 25, 45, and 70 µM of the combined glucosinolates) were used to examine the ability of these extracts to influence the growth of bladder cancer cell lines in vitro using the MTS assay and direct cell counting. Bladder cancer cell lines examined include: human RT4 (superficial transitional cell carcinoma), human J82 (invasive transitional cell carcinoma), and murine MB49 (derived from a chemically induced bladder cancer). The broccoli sprout isothio-cyanate fraction decreased cell proliferation in all three cell lines; the effect was strongest in the J82 cell line, where the IC50 was 15 µM of total converted glucosinolates. The unconverted glucosinolate extract did not alter growth. Overall, this study supports the hypothesis that cruciferous vegetables may contain phyto-chemicals that may directly influence bladder cancer cells. Additional studies will examine how the phyto-chemicals regulate cell proliferation, apoptosis, and other mechanisms of action related to bladder cancer risk.