A broader filtration of UVA1 wavelengths improves skin photoprotection

Sun exposure involves ultraviolet (UV) rays: UVB (290-320 nm), UVA2 (320-340 nm) and UVA1 (340-400 nm). UVA1 rays represent the majority of UV reaching the Earth surface. In human, UVA1 induces an immediate and persistent non-protective skin darkening and contribute to photoaging, immunosuppression and carcinogenesis [1–4]. Using in vitro reconstructed skin, we showed that UVA1 exposure generated reactive oxygen species and led to epidermal damage and fibroblast apoptosis. A strong UVA1-induced alteration of the expression of genes encoding proteins involved in essential biological pathways was also evidenced in this 3D model, and in human skin in vivo [5,6].