title: Effect of alpha-tocopherol and N-acetylcysteine on benzoyl peroxide toxicity in human keratinocytes.
abstract: Benzoyl peroxide is a free-radical generating compound widely used in the polymer industry and also in pharmaceuticals as antimicrobial agent to treat acne. However, benzoyl peroxide causes irritation and contact dermatitis in about 1% of patients. Concern over the use of this compound is motivated by the demonstration that it can also act as skin tumor promoter in mice. In addition, benzoyl peroxide induces DNA strand breaks in many cells, including keratinocytes. Benzoyl peroxide toxicity is presumably mediated by the formation of reactive free radicals and by the consumption of intracellular antioxidants. In this work we investigated the effect of both the lipophilic antioxidant alpha-tocopherol and the hydrophilic thiol donor N-acetylcysteine (NAC) in human keratinocyte line HaCaT exposed to benzoyl peroxide. A protective effect against benzoyl peroxide cytotoxicity was achieved when cells were grown on a alpha-tocopherol layer. On the contrary, the addition of alpha-tocopherol dissolved in ethanol had a pro-oxidant effect, leading to an enhancement of benzoyl peroxide toxicity. Cytotoxicity was also reduced adding NAC to the culture medium; the presence of both NAC and alpha-tocopherol exerts a synergistic cytoprotection.
authors.affiliation: Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bellei
authors.forename: Cristina
authors.initials: C
authors.lastname: Rota
authors.forename: Stefania
authors.initials: S
authors.lastname: Bergamini
authors.forename: Paolo
authors.initials: P
authors.lastname: Manfredini
authors.forename: Alberto
authors.initials: A
authors.lastname: Albertazzi
authors.forename: Aldo
authors.initials: A
authors.lastname: Tomasi
authors.forename: Anna
authors.initials: A
authors.lastname: Iannone
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001585:Benzoyl Peroxide / Q000633:toxicity*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D024502:alpha-Tocopherol / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D005978:Glutathione; D024502:alpha-Tocopherol; D019803:Glutathione Disulfide; D001585:Benzoyl Peroxide; D000111:Acetylcysteine