Glucosinolates in cancer prevention and treatment: experimental and clinical evidence.

Glucosinolates are naturally occurring β-d-thioglucosides that mainly exist in the Brassicaceae family. The enzyme myrosinase hydrolyzes glucosinolates to form isothiocyanates, which are chemical protectors. Phenethyl isothiocyanate, sulforaphane, and benzyl isothiocyanate are potential isothiocyanate with efficient anti-cancer effects as a protective or treatment agent. Glucosinolate metabolites exert the cancer-preventive activity through different mechanisms, including induction of the Nrf2 transcription factor, inhibition of expression of tumor necrosis factor-α (TNFα) and interleukin-1β (IL-1β), induction of apoptosis through inhibiting phase I enzymes and inducting phase II enzymes, interruption of caspase pathways, STAT1/STAT2, inhibition of sulfotransferases. Moreover, glucosinolates and their metabolites are effective in cancer treatment by inhibiting angiogenesis, upregulating natural killers, increasing expression of p53, p21, caspase 3 and 9, and modulating NF-κB. Despite the mentioned cancer-preventing effects, some isothiocyanates can increase the risk of tumors. So, further studies are needed to obtain an accurate and effective dose for each glucosinolates to treat different types of tumors.