This is being further explored. It is likely that the major bioactive products derived from broccoli are the isothiocyanates, sulforaphane and iberin. These have been shown to have a multitude of biological activities in cell models consistent with anticarcinogenic activity. However, these studies largely involve exposing cells to concentrations of SF and IB far in excess of those which occur transiently in the plasma after broccoli consumption, and are mediated by the intracellular activity of the ITCs by, for example, Labetalol hydrochloride perturbing intracellular redox status, depletion of glutathione and perturbation of the Keap1Nfr2 complex. We question whether these processes would occur in vivo, as any of the ITCs entering cells would immediately be inactivated through conjugation with glutathione that would be present in relatively high concentration. Thus, we explored whether the biological activity of ITCs may be mediated through their chemical interaction with signalling peptides within the extracellular environment of the plasma, which has a low glutathione concentration. We demonstrated that ITCs readily form thioureas with signalling proteins in the plasma through covalently Albaspidin-AA bonding with the N-terminal residue. It is likely that ITCs chemically react with other plasma proteins and a global analysis of plasma protein modifications by ITCs 
is warranted. It is also possible that other types of chemical modification of plasma proteins by ITCs may occur, such as covalent bonding through cysteine and lysine residues. Previous studies have shown that isothiocyanate-derived thioureas modify the physicochemical and enzymatic properties of the parental proteins. Thus, it is possible that the perturbation of signalling pathways in the prostate is mediated by protein modifications that occur in the extracellular environment. We provide further evidence for this hypothesis by demonstrating that pre incubation of TGFb1 with a physiological appropriate concentration of SF, followed by dialysis for 4 h to simulate SF pharmacokinetics, results in enhanced Smadmediated transcription. As TGFb1/Smad-mediated transcription inhibits cell proliferation in non-transformed cells, the enhancement of Smad-mediated transformation by SF would be consistent with the anticarcinogenic activity of broccoli, in addition to reduced risk of myocardial infarction.