Dietary Glucosinolates Sulforaphane, Phenethyl Isothiocyanate, Indole-3-Carbinol/3,3′-Diindolylmethane: Antioxidative Stress/Inflammation, Nrf2, Epigenetics/Epigenomics and In Vivo Cancer Chemopreventive Efficacy

Glucosinolates are a group of sulfur-containing glycosides found in many plant species, including cruciferous vegetables such as broccoli, cabbage, Brussels sprouts, and cauliflower. Accumulating evidence increasingly supports the beneficial effects of dietary glucosinolates on overall health, including as potential anticancer agents, because of their role in the prevention of the initiation of carcinogenesis via the induction of cellular defense detoxifying/antioxidant enzymes and their epigenetic mechanisms, including modification of the CpG methylation of cancer-related genes, histone modification regulation and changes in the expression of microRNAs (miRNAs). In this context, the defense mechanism mediated by Nrf2-antioxidative stress and anti-inflammatory signaling pathways can contribute to cellular protection against oxidative stress and reactive metabolites of carcinogens. In this review, we summarize the cancer chemopreventive role of naturally occurring glucosinolate derivatives as inhibitors of carcinogenesis, with particular emphasis on specific molecular targets and epigenetic alterations in in vitro and in vivo human cancer animal models.