Inhibitory effect of an extract of Sanguisorba officinalis L. on Ultraviolet-B-induced photodamage of rat skin

We previously reported that chronic Ultraviolet-B (UVB) irradiation causes wrinkle formation, decreases skin elasticity and damages/curls dermal elast ic fibers. Those UVB-induced wrinkles can be improved by treatment with ret inoic acid or with a CO,, laser which results in a recovery of skin elastic ity and a repair of elastic fiber linearity. We showed further that topical application of N-phenetyl-leucyl-tryptophane, an agent that specifically i nhibits fibroblast-derived elastase, immediately after UVB irradiation inhi bited UVB-induced wrinkle formation, maintained skin elasticity, and inhibi ted changes in the three-dimensional structure of dermal elastic fibers in a dose-dependent manner. In this study, the effects of an extract of Sangui sorba officinalis L., which also inhibits fibroblast-derived elastase, was evaluated for possible inhibition of UVB induced wrinkle formation, mainten ance of skin elasticity, and prevention of damage to the 3-dimensional stru cture of dermal elastic fibers. Hind limb skins of 3-week-old Sprague-Dawle y rats were irradiated with UVB at a suberythemal dose 3 times a week for 6 weeks. Simultaneously, an extract of Sanguisorba officinalis L. (at 0.2% ( v/v) or 1% (v/v)) was topically applied 5 times per week immediately follow ing each UVB irradiation and 1 d later. The extract of Sanguisorba officina lis L. inhibited wrinkle formation, maintained skin elasticity, and inhibit ed the decrease of dermal elastic fiber linearity in the rat hind limb skin in a dose-dependent manner. We have confirmed that the inhibition of elast ase activity in fibroblasts immediately after UVB irradiation using an extr act of Sanguisorba officinalis L. prevents chronic photodamage following UV B irradiation.