Beneficial effect of curcumin on epidermal permeability barrier function
Curcumin is a low molecular polyphenol isolated from turmeric. Recent researches have revealed that curcumin has beneficial effect in various skin diseases such as scleroderma, psoriasis and skin cancer . However, studies on an effect of curcumin on epidermal barrier function have been scarce.
In this study, we investigated the effect of curcumin on epidermal permeability barrier function in vitro and in vivo. We analyzed the expression of filaggrin, a marker of keratinocyte differentiation, and serine palmitoyltransferase (SPT), a marker of formation of the stratum corneum lipid barrier, in human HaCaT keratinocyte [2,3]. To evaluate the effect of curcumin on epidermal permeability barrier function in vivo, hairless rats were exposed to UVB irradiation to induce epidermal barrier function perturbation and curcumin was treated orally with 150mg/kg per day for 8 weeks. Transepidermal water loss (TEWL) was measured at the end of experiment. We also investigated the morphological changes using histological examination.
Our results showed the concentration-dependent effect of curcumin on the expression of both filaggrin and SPT in HaCaT cells, reflecting that curcumin can induce epidermal keratinocyte differentiation and improve the recovery of skin barrier function. In vivo experiment revealed that 8 weeks administration of curcumin markedly prevented the UVB-induced increase in TEWL. UV-induced increase of epidermal thickness was also significantly reduced by curcumin treatment. These results suggest that curcumin is a potent candidate for the improvement of epidermal permeability barrier function.
References: 1. Thangapazham, RL. et al. (2007) Adv Exp Med Biol. 595:343–57. 2. Lim, S.W. et al. (2007)J Dermatol. 34:625–34. 3. Farrell, A.M. et al. (1998)J Lipid Res. 39:2031–8.