title: Differences in visible light-induced pigmentation according to wavelengths: a clinical and histological study in comparison with UVB exposure.
abstract: The visible light spectrum is wide, and it can be hypothesized that all the wavelengths between 400-700 nm do not induce the same photobiological effects on pigmentation. We assessed the potential pro-pigmenting effects of two single wavelengths located at both extremities of the visible spectrum: the blue/violet line (λ = 415 nm) and the red line (λ = 630 nm). We made colorimetric, clinical, and histological assessments with increasing doses of those lights on healthy volunteers. Then, we compared these irradiations to non-exposed and UVB-exposed skin. Colorimetric and clinical assessments showed a clear dose effect with the 415-nm irradiation, in both skin type III and IV subjects, whereas the 630 nm did not induce hyperpigmentation. When compared to UVB irradiation, the blue-violet light induced a significantly more pronounced hyperpigmentation that lasted up to 3 months. Histological examination showed a significant increase of keratinocyte necrosis and p53 with UVB, as compared to 415- and 630-nm exposures.
authors.affiliation: Centre de Pharmacologie Clinique Appliquée à la Dermatologie (CPCAD), University hospital of Nice, Nice, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Duteil
authors.forename: Nathalie
authors.initials: N
authors.lastname: Cardot-Leccia
authors.forename: Catherine
authors.initials: C
authors.lastname: Queille-Roussel
authors.forename: Yves
authors.initials: Y
authors.lastname: Maubert
authors.forename: Yona
authors.initials: Y
authors.lastname: Harmelin
authors.forename: Fériel
authors.initials: F
authors.lastname: Boukari
authors.forename: Damien
authors.initials: D
authors.lastname: Ambrosetti
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lacour
authors.forename: Thierry
authors.initials: T
authors.lastname: Passeron
mesh_terms: D003124:Colorimetry; D064368:Healthy Volunteers; D006801:Humans; D017495:Hyperpigmentation / Q000473:pathology; D015603:Keratinocytes / Q000166:cytology; D008027:Light; D008544:Melanocytes / Q000166:cytology*; D009336:Necrosis; D010858:Pigmentation / Q000502:physiology*; D012867:Skin / Q000528:radiation effects*; D012880:Skin Pigmentation / Q000502:physiology*; D013473:Sunscreening Agents; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D013473:Sunscreening Agents; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53
keywords: UVB; melanogenesis; p53; pigmentation; visible light