Artigo
The oxidation of p-phenylenediamine, an ingredient used for permanent hair dyeing purposes, leads to the formation of hydroxyl radicals: oxidative stress and DNA damage in human immortalized keratinocytes
Registro en:
Toxicology Letters, v. 239, n. 3, p. 194-204, 2015.
1879-3169
10.1016/j.toxlet.2015.09.026
26456176
0000-0002-2296-1393
Autor
Zanoni, Thalita Boldrin
Hudari, Felipe [UNESP]
Munnia, Armelle
Peluso, Marco
Godschalk, Roger W.
Zanoni, Maria Valnice Boldrin [UNESP]
den Hartog, Gertjan J. M.
Bast, Aalt
Barros, Silvia Berlanga de Moraes
Maria-Engler, Silvya Stuchi
Hageman, Geja J.
Oliveira, Danielle Palma de
Resumen
The hair-dyeing ingredient, p-phenylenediamine (PPD), was previously reported to be mutagenic, possibly by inducing oxidative stress. However, the exact mechanism of PPD in inducing oxidative stress upon skin exposure during hair-dyeing in human keratinocytes remains unknown. The aim of our studies was therefore to investigate the toxicity of PPD and its by-products in human immortalized keratinocytes (HaCaT) after auto-oxidation and after reaction with hydrogen peroxide (H2O2). We found that the PPD half maximal effective cytotoxic concentration (EC50) to HaCaT is 39.37 and 35.63μg/mL after 24 and 48h, respectively, without addition of H2O2 to induce oxidation. When PPD (10 or 100μg/mL) is combined with 10.5μg/mL of H2O2, intracellular ROS production by HaCaT after 1h was significantly increased and enhanced levels of DNA damage were observed after 4h of exposure. After 24h incubations, 20μg/mL of PPD increased the level of DNA oxidation in HaCaT. Also, we found that the in vitro reaction between PPD and H2O2, even below the maximum allowance by cosmetic industries, released hydroxyl radicals which can damage DNA. Taken together, we conclude that PPD alone and when combined with H2O2 increases the formation of reactive oxygen species in human keratinocytes, leading to oxidative stress and subsequent DNA damage. These alterations suggest that the mechanism by which PPD exposure, alone or combined with H2O2, damages keratinocytes by the formation of the high reactive HO radicals. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Universidade de São Paulo, Departamento de Toxicologia Ambiental, Faculdade de Ciências Farmacêuticas de Ribeirão Preto Maastricht University, Department of Toxicology, School of Nutrition and Translational Research in Metabolism Universidade de São Paulo, Departamento de Química e Toxicologia Clínica, Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista, Departamento de Química Analítica, Instituto de Química de Araraquara FAPESP: 2008/10449-7 FAPESP: 2010/07116-6 FAPESP: 2012/05961-6