Preventive effects of broccoli bioactives : role on Oxidative stress and cancer risk

Cruciferous vegetables (such as broccoli) seem to have an important role in cancer prevention, as suggested by the results of several epidemiological studies showing an inverse association between their consumption and cancer risk at several sites. This class of vegetables contains several antioxidants and provides glucosinolates, which are converted to isothiocyanates and indoles, the bioactives believed to be responsible for most of the protection against cancer development. Numerous mechanisms of action have been studied; they involve interconnected signaling pathways important for cancer growth and progression including the direct and indirect effect on oxidative stress, and modulation of phase I and phase II enzymes and of epigenetic mechanisms. In particular, brassica vegetables may contribute to reducing free radical-related molecular damage in subjects, such as smokers, with high exposure to oxidative stress. In this regard, the effect of broccoli intake on biomarkers of oxidative stress and cancer risk in smokers is briefly discussed.