Eberlin S, Clerici SP, Eberlin S, Pinheiro ALTA, Pinheiro AS.
Skin pigmentation is dependent on both the increased number of melanocytes as the increase on melanogenic enzymes. Exposure to sunlight can increase the production of factors such as melanocyte stimulating hormone and endothelin-1, which trigger the melanization of the skin. In addition to ultraviolet light, studies also show that the infrared radiation and visible light promote changes in skin pigmentation. In this work we evaluated the consequences of ultraviolet A and B (UVA/UVB), infrared-A (IR-A) and visible light (VL) irradiation on melanin and endothelin-1 synthesis, using an in vitro model of melanocyte and keratinocyte cultures, and ex vivo model of skin culture. All radiations (UV, IR-A, VL and Association of radiations) produced a significant increase in melanin production when compared to non-irradiated control. UV radiation, VL and the association of all radiation produced a significant increase in the production of endothelin-1 when compared to non-irradiated control. Skin fragments subjected to all radiation have a higher melanin density in comparison with control fragments. Our results corroborate previous data from literature and indicated the need for specific photoprotection strategies which are not addressed by the available conventional sunscreens.