Polypodium leucotomos extract inhibits trans-urocanic acid photoisomerization and photodecomposition

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 82; no. 3; pp. 173 - 179
• Main Authors: Capote, R., Alonso-Lebrero, J.L., Garcı́a, F., Brieva, A., Pivel, J.P., González, S.
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 01.03.2006
• Subjects: Cells, Cultured; H 2O 2; Humans; Hydrogen Peroxide - chemistry; Photochemistry; Photoisomerization; Polypodium; Polypodium - chemistry; Reactive Oxygen Species - metabolism; Titanium - chemistry; Titanium dioxide; Ultraviolet radiation; Ultraviolet Rays; Urocanic acid; Urocanic Acid - chemistry; H 2O 2; Polypodium; Ultraviolet radiation; Photoisomerization; Titanium dioxide; Urocanic acid
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2005.11.005

In this report, we demonstrate a possible molecular mechanism by which a hydrophilic extract of the leaves of the fern Polypodium leucotomos (Fernblock ®, PL) blocks ultraviolet (UV)-induced skin photodamage. The extract inhibits UVA and UVB light induced photoisomerization of trans-urocanic acid ( t-UCA), a common photoreceptor located in the stratum corneum, and also blocks its photodecomposition in the presence of oxidizing reagents such as H 2O 2, and titanium dioxide (TiO 2). PL protects in vitro human fibroblasts from UV-induced death as well. These results suggest the potential of employing the PL extract as a component of sunscreen moistures in order to prevent photodecomposition of t-UCA, to inhibit UV-induced deleterious effects of TiO 2 and to protect skin cells and endogenous molecules directly involved in skin immunosurveillance.