FLAVONOIDS IN SKIN CANCER CHEMOPREVENTION

摘要

UV radiation is a very potent initiator of photochemical reactions. In biological systems, the absorbed light can interact with endogenous molecules (lipids, proteins and DNA) so producing, directly or indirectly, deleterious cytotoxic andgenotoxic effects. Chronic exposure of mammalian skin to UV radiation induces a number of biological responses (including edema, hyperplasia, immune suppression, DNA damage, photoaging, etc.), which may be involved in the development of skin cancer. Thus, it is imperative to protect the skin from UV light-induced damage. Recent researches have been carried out to investigate the scientific basis for photoprotection by naturally occurring antioxidants to be topically or systemically employed for minimizing the harmful effect of sun exposure. Several plant compounds have gained considerable attention as chemopreventers effective against skin cancer. In particular, flavonoids represent an interesting class of active compounds in the protection of UV light-induced skin damage due to their wide spectrum of activities including anti-inflammatory, antioxidant, anti-mutagenic, anti-carcinogenic and capability to modulate enzyme activities involved in cell response. Herein the state of art of flavonoids in the protection against UV-induced skin cancer will be reviewed, with particular regard for issues relating to their topical application or oral administration.