Protective and therapeutic effects of fucoxanthin against sunburn caused by UV irradiation

Mild exposure to ultraviolet (uv) radiation is also harmful and hazardous to the skin and often causes a photosensitivity disorder accompanied by sunburn. to understand the action of uv on the skin we performed a microarray analysis to isolate uv-sensitive genes. we show here that uv irradiation promoted sunburn and downregulated filaggrin (flg); fucoxanthin (fx) exerted a protective effect. in vitro analysis showed that uv irradiation of human dermal fibroblasts caused production of intracellular reactive oxygen species (ros) without cellular toxicity. ros production was diminished by n-acetylcysteine (nac) or fx,but not by retinoic acid (ra). in vivo analysis showed that uv irradiation caused sunburn and flg downregulation,and that fx,but not nac,ra or clobetasol,exerted a protective effect. fx stimulated flg promoter activity in a concentration-dependent manner. flg promoter deletion and chromatin immunoprecipitation analysis showed that caudal type homeo box transcription factor 1 (cdx1) was a key factor for flg induction. cdx1 was also downregulated in uv-exposed skin. therefore,our data suggested that the protective effects of fx against uv-induced sunburn might be exerted by promotion of skin barrier formation through induction of flg,unrelated to quenching of ros or an ra-like action. © 2016 the authors