Un approccio globale per aggirare gli effetti dannosi della luce blu e delle radiazioni IR-A sulla pelle

Time: 11:30 - 11:55

Date: 25 Novembre 2020

Theatre: Turquoise 1

V.Bicard-Benhamou, L. Heider, M. Lefort, J. zur Lage, S. Hornung, H. Hanau, A. Kielbassa, J. von Hagen

It remains in minds that photoprotection is mainly a matter of UV protection. However, all solar radiations lead to the formation of radical oxygen species (ROS) and excess free radicals in skin, and herewith contribute to premature skin aging and wrinkling. There are already powerful solutions to address light protection beyond UV, notably in the HEV and IR-A range, considering a first defense line strategy – i.e. avoiding any radiations to enter the skin, and this by using appropriate combi-nations of titanium dioxide UV filters and mica-based functional fillers (1), (2).

In this work we present a complementary approach targeting second defense line to address radical damages that nevertheless may occur in the skin following an over-exposure to HEV and/or IR radiations. Test candidates from different origin were selected to maximize performance: synthetic and biotechnological molecules, natural extracts. Substantiating the link between first defense and impact on relevant biochemical markers after a stress to HEV/IR-A was also in focus. Therefore, a system containing a titanium dioxide UV filter was also tested. The protective effect of the different ingredients against HEV (400-520 nm) and IR-A (760-1200 nm) radiations was investigated on living human skin explants by assessing following parameters: expression of Tropoelastin and MMP-1 for explants irradiated with IR; expression of MMP-1, 8-OhdG (reflecting the degree of oxidative damage to DNA), oxidized protein level, and Opsin-3 (working as a sensor for blue light in melanocytes and activating melanogenesis) for explants irradiated with HEV.

First results show very promising protective effects on irradiated explants treated with the different products vs. irradiated non-treated explants. For example, a natural extract with known cascading antioxidant properties protected Tropoelastin after IR-A irradiation and reduced Opsin-3 expression after HEV irradiation. A multi-talented synthetic antioxidant had a positive impact on all tested markers. Finally, an emulsion containing a broad-spectrum TiO2 UV filter could protect from oxidative damages in skin, thus validating the effectiveness of a first defense line strategy at the biological level.

Our global screening approach enabled us to identify how various active ingredients with different structure and origin can circumvent harmful effects of blue light and IR-A radiations. This paves the way for innovative solutions to fulfill justified increasing needs and wishes from consumer side to protect the skin more effectively against HEV and IR light, in addition to classical UVA/B protection.

(1)     Rozman V. et al., SOFW Journal 2017, 143 (9)

(2)     Lefort M. et al., IFSCC Magazine 2019, 22 (1)

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