title: N-acetyl cysteine directed detoxification of 2-hydroxyethyl methacrylate by adduct formation.
abstract: Cytotoxicity of the dental resin monomer 2-hydroxyethyl methacrylate (HEMA) and the protective effects of N-acetyl cysteine (NAC) on monomer-induced cell damage are well demonstrated. The aim of our study was to analyze the hypothesis that the protection of NAC from HEMA cytotoxicity might be due to direct NAC adduct formation. To this end, using HPLC we first measured the actual intracellular HEMA concentrations able to cause toxic effects on 3T3-fibroblasts and then determined the decrease in intracellular and extracellular HEMA levels in the presence of NAC. In addition, by capillary electrophoresis coupled with mass spectrometry analysis (CE-MS), we evaluated NAC-HEMA adduct formation. HEMA reduced 3T3 cell vitality in a dose- and time-dependent manner. The concentration of HEMA inside the cells was 15-20 times lower than that added to the culture medium for cell treatment (0-8 mmol/L). In the presence of 10 mmol/L NAC, both intracellular and extracellular HEMA concentrations greatly decreased in conjunction with cytotoxicity. NAC-HEMA adducts were detected both in the presence and absence of cells. Our findings suggest that the in vitro detoxification ability of NAC against HEMA-induced cell damage occurs through NAC adduct formation. Moreover, we provide evidence that the actual intracellular concentration of HEMA able to cause cytotoxic effects is at least one magnitude lower than that applied extracellularly.
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University, Rome, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Nocca
authors.forename: Vincenzo
authors.initials: V
authors.lastname: D'Antò
authors.forename: Claudia
authors.initials: C
authors.lastname: Desiderio
authors.forename: Diana Valeria
authors.initials: DV
authors.lastname: Rossetti
authors.forename: Rosa
authors.initials: R
authors.lastname: Valletta
authors.forename: Adriana Marquez
authors.initials: AM
authors.lastname: Baquala
authors.forename: Helmut
authors.initials: H
authors.lastname: Schweikl
authors.forename: Alessandro
authors.initials: A
authors.lastname: Lupi
authors.forename: Sandro
authors.initials: S
authors.lastname: Rengo
authors.forename: Gianrico
authors.initials: G
authors.lastname: Spagnuolo
mesh_terms: D016475:3T3 Cells; D000111:Acetylcysteine / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D019075:Electrophoresis, Capillary; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D013058:Mass Spectrometry; D008689:Methacrylates / Q000737:chemistry* / Q000633:toxicity*; D051379:Mice
chemical_list: D008689:Methacrylates; C005044:hydroxyethyl methacrylate; D000111:Acetylcysteine