Epidemiological, clinical and laboratory studies have implicated solar ultraviolet (UV) radiation in various skin diseases
including, premature aging of the skin and melanoma and non-melanoma skin cancers. Chronic UV radiation exposure-induced skin
diseases or skin disorders are caused by the excessive induction of inflammation, oxidative stress and DNA damage, etc. The
use of chemopreventive agents, such as plant polyphenols, to inhibit these events in UV-exposed skin is gaining attention.
Chemoprevention refers to the use of agents that can inhibit, reverse or retard the process of these harmful events in the
UV-exposed skin. A wide variety of polyphenols or phytochemicals, most of which are dietary supplements, have been reported
to possess substantial skin photoprotective effects. This review article summarizes the photoprotective effects of some selected
polyphenols, such as green tea polyphenols, grape seed proanthocyanidins, resveratrol, silymarin and genistein, on UV-induced
skin inflammation, oxidative stress and DNA damage, etc., with a focus on mechanisms underlying the photoprotective effects
of these polyphenols. The laboratory studies conducted in animal models suggest that these polyphenols have the ability to
protect the skin from the adverse effects of UV radiation, including the risk of skin cancers. It is suggested that polyphenols
may favorably supplement sunscreens protection, and may be useful for skin diseases associated with solar UV radiation-induced
inflammation, oxidative stress and DNA damage.
Keywords Interleukin - DNA repair - Antioxidant - Anti-inflammation - Polyphenols - Ultraviolet radiation - Cyclooxygenase-2