Systemic photoprotection by carotenoids

Abstract

Carotenoids are micronutrients present in fruits and vegetables and ingested with the diet. They exhibit specific antioxidant activity and also influence cellular signaling and gene expression at the cellular level. b-Carotene and lycopene, the colorants of carrots respectively tomatoes, are among the most prominent members of this group and the dominating carotenoids in human blood and tissues. Both compounds modulate skin properties when ingested with supplements or dietary products. They protect against sunburn by increasing the basal defense against UV light-mediated damage to the skin although their efficacy is not comparable to the use of a sunscreen. In-vitro data provide evidence that also other carotenoids are efficient photoprotectors. Among them are lutein and structurally unusual phenolic polyenes like 3,3'- dihydroxyisorenieratene. © 2011 Springer- Verlag Berlin Heidelberg.