The antigenotoxic potential of dietary flavonoids

Human exposure to genotoxic agents has dramatically increased. Both endogenous (reactive species generated during physiological and pathological processes) and exogenous (UV light, ionizing radiation, alkylating agents, antimetabolites and topoisomerase inhibitors, air, water and food pollutants) factors can impair genomic stability. The cumulative DNA damage causes mutations involved in the development of cancer and other disorders (neuromuscular and neurodegenerative diseases, immune deficiencies, infertility, cardiovascular diseases, metabolic syndrome and aging). Dietary flavonoids have protective effects against DNA damage induced by different genotoxic agents such as mycotoxins, food processing-derived contaminants (polycyclic aromatic hydrocarbons, N-nitrosamines), cytostatic agents, other medications (estrogenic and androgenic hormones), nicotine, metal ions (Cd2+, Cr6+), radiopharmaceuticals and ionizing radiation. Dietary flavonoids exert their genoprotection by reducing oxidative stress and modulation of enzymes responsible for bioactivation of genotoxic agents and detoxification of their reactive metabolites. Data on structure-activity relationship is sometimes contradictory. Free hydroxyl groups on the B ring (catechol moiety) and C-3 position of the C ring are important structural features for the antigenotoxic activity. As dietary flavonoids are extensively metabolized, more in vivo studies are needed for a better characterization of their antigenotoxic potential.