In vitro induction of benzo(a)pyrene cell-transforming activity by the glucosinolate gluconasturtiin found in cruciferous vegetables

Cytotoxic and cell-transforming activity of gluconasturtiin (GNST), a promising chemopreventive agent commonly found in human diet, was studied in a medium-term bioassay utilizing BALB/c 3T3 cells. We also assessed whether GNST coupled with myrosinase, thus yielding product phenylethyl isothiocyanate (as shown by gas chromatography–mass spectral analysis), can affect the transforming potential of benzo(a)pyrene (B(a)P). Neither cytotoxicity nor cell-transforming activity was recorded. On the contrary, a marked increase (up to sevenfold) of the transforming activity of B(a)P was seen. This cocarcinogenic potential could be ascribed to an imbalance among bioactivation/detoxication during cell growth. These results indicate the need for an overall toxicological characterization of a chemopreventive agent prior to large-scale use.