title: Basic Red 51, a permitted semi-permanent hair dye, is cytotoxic to human skin cells: Studies in monolayer and 3D skin model using human keratinocytes (HaCaT).
abstract: The use of hair dyes is closely associated with the increase of cancer, inflammation and other skin disorders. The recognition that human skin is not an impermeable barrier indicates that there is the possibility of human systemic exposure. The carcinogenic potential of hair dye ingredients has attracted the attention of toxicologists for many decades, mainly due to the fact that some ingredients belong to the large chemical family of aromatic amines. Herein, we investigated the cytotoxicity of Basic Red 51 (BR51) in immortalized human keratinocytes (HaCaT). BR51 is a temporary hair dye that belongs to the azo group (NN); the cleavage of this bond may result in the release of toxic aromatic amines. The half maximal effective concentration (EC50) in HaCaT cells is 13μg/mL. BR51 induced a significant decrease on expression of p21 in a dose dependent manner. p53 was not affected, whereas BR51 decreased procaspase 8 and cleaved procaspase 9. These results proved that caspase 3 is fully involved in BR51-induced apoptosis. The dye was also able to stop this cell cycle on G2 in sub-toxic doses. Moreover, we reconstructed a 3D artificial epidermis using HaCaT cells; using this model, we observed that BR51 induced cell injury and cells were undergoing apoptosis, considering the fragmented nuclei. Subsequently, BR51 induced reactive oxygen species (ROS) leading to an increase on the levels of 8-oxo-dG. In conclusion, we provide strong evidence that consumer and/or professional exposure to BR51 poses risk to human health.
authors.affiliation: Department of Environmental Toxicology, School of Pharmaceutical Sciences, University of São Paulo, Ribeirao Preto, Brazil. Electronic address: thalitaz@fcfrp.usp.br.
authors.forename: Thalita B
authors.initials: TB
authors.lastname: Zanoni
authors.affiliation: Department of Clinical Chemistry & Toxicology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Manoela
authors.initials: M
authors.lastname: Tiago
authors.affiliation: Department of Clinical Chemistry & Toxicology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Faião-Flores
authors.affiliation: Department of Clinical Chemistry & Toxicology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Silvia B
authors.initials: SB
authors.lastname: de Moraes Barros
authors.affiliation: Toxicology, Research Institute NUTRIM, Maastricht University, Maastricht, Netherlands.
authors.forename: Aalt
authors.initials: A
authors.lastname: Bast
authors.affiliation: Toxicology, Research Institute NUTRIM, Maastricht University, Maastricht, Netherlands.
authors.forename: Geja
authors.initials: G
authors.lastname: Hageman
authors.affiliation: Department of Environmental Toxicology, School of Pharmaceutical Sciences, University of São Paulo, Ribeirao Preto, Brazil.
authors.forename: Danielle Palma
authors.initials: DP
authors.lastname: de Oliveira
authors.affiliation: Department of Clinical Chemistry & Toxicology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Silvya S
authors.initials: SS
authors.lastname: Maria-Engler
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001391:Azo Compounds / Q000737:chemistry / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006202:Hair Dyes / Q000737:chemistry / Q000633:toxicity*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects*; D015394:Molecular Structure; D009336:Necrosis / Q000139:chemically induced
chemical_list: D001391:Azo Compounds; D006202:Hair Dyes; C000589147:Basic Red 51
keywords: 3D organotipic culture; Basic Red 51; HaCaT; Temporary hair dye