UVA1 rays (340–400 nm) representing at least 75% of solar UVs, generate cellular oxidative stress and are able to induce cutaneous damage and impairment of functions (immunity, development, inflammation, dermal matrix organization). Clinically, they contribute to hyperpigmentation, immunosuppression, carcinogenesis and photoaging. State of the art sunscreens can filter UV rays up to 370 nm, but lack absorption in the 370–400 nm range supporting the development of new UVA1 filters. The absorber Methoxypropylamino Cyclohexenylidene Ethoxyethylcyanoacetate (MCE), exhibiting a peak of absorption at 385 nm has recently been listed in the Annex VI of EU authorized UV filters for use in suncreens. The present studies evaluated, in a 3D skin model and in clinical trials, the protection afforded by state of the art sunscreen formulations covering UVB, UVA2 and UVA1 up to 370nm and similar formulas enriched with MCE filter thus covering the whole UV spectrum. Photoprotection was evaluated through morphological and gene expression analysis in 3D skin model exposed to UVA1 as well as in intra-individual trials conducted under controlled UVA1 or UVB+UVA exposure, and real sun. Induced pigmentation was followed as the clinical surrogate for UV impact using colorimetry and visual scoring. In 3D skin model, formulations with MCE compared to reference sunscreen, enabled significantly higher protection of the epidermis and the dermis and higher reduction of modulations of gene expression. In vivo, whatever the exposure condition (UVA1, UVB+UVA, real sun), the level of pigmentation was increased. In the three studies, the comparison showed a higher prevention of hyperpigmentation with the sunscreen with MCE compared to the state-of-the-art sunscreen. In conclusion, thanks to the UVA1 filtering properties of MCE leading to a full coverage of UVs in sunscreens, a higher photoprotection against sun-induced biological and clinical impacts was achieved.

ESDR536 - UVA1 harmful effects and benefit of an enlarged photoprotection covering the whole UV spectrum.

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.