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Lichenic extracts and metabolites as UV filters
Françoise Lohézic-Le Dévéhat1, Béatrice Legouin, Céline Couteau
1PNSCM-UMR 6226; Faculté des Sciences Pharmaceutiques et Biologiques, Université Européenne de Bretagne, Université de Rennes 1, 2 Av. du Pr Léon Bernard, 35043 Rennes Cedex, France. francoise.le-devehat@univ-rennes1.fr
Abstract:
Three lichen extracts and ten lichenic compounds have been screened for their photoprotective activities. The determination of their Sun Protection Factor (SPF) and Protection Factor-UVA (PF-UVA) values was done in vitro. Among them, a Lasallia pustulata extract and gyrophoric acid exhibited SPF values over 5, which is better than Homosalate (SPF≈4). Their photoprotective properties are only slightly modified after a 2-hours period of irradiation. Salazinic acid and L. pustulata presented characteristics of a UVA booster like the butyl-methoxydibenzoylmethane (Avobenzone) (PF-UVA≈2 vs. 2.8 for Avobenzone). Salazinic acid was a better anion superoxide scavenger than ascorbic acid and none of them exhibited a photosensitizing cytotoxicity by exposing them on HaCaT cells to UVA radiations (photo-irritancy factor PIF<5).
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