Myrosinase-generated isothiocyanate from glucosinolates: isolation, characterization and in vitro antiproliferative studies.

Epidemiological and pharmacological studies have shown that colorectal cancer development could be reduced by consuming vegetables that contain glucosinolates. In view of this the effect of some glucosinolates and their isothiocyanate (ITC)-derived products on in vitro cell growth was studied. We report the isolation and characterization of ITCs derived from glucosinolates by using HPLC, GC-MS, and NMR techniques. The in vitro activity of ITCs on human erythroleukemic K562 cells has been investigated by using two alternative approaches: the in situ and pre-mix methods. No differences in antiproliferative activity were found comparing the effect of ITCs produced either of these methods. In the experimental conditions used, the production of ITCs from glucosinolates is almost quantitative as confirmed by HPLC or GC-MS analysis. The ITCs' inhibitory activity on K562 cells growth is particularly evident in the cases of ITCs derived from sinigrin, progoitrin, epi-progoitrin, glucotropaeolin and glucocheirolin. Finally, the antiproliferative activity of the ITCs obtained from glucoraphenin, taken as an example, was determined on other tumor cell lines with a different origin and hystotype. Considering the antiproliferative activity found for ITCs these compounds could be considered potentially responsible for the reduction of colorectal cancer associated with diets rich in cruciferous vegetables. Further studies will be aimed at the possible application of glucosinolate-derived products as chemopreventive cancer agents.