title: Dose-response and time-course of α-tocoferol mediating the cytoprotection of dental pulp cells against hydrogen peroxide.
abstract: This in vitro study evaluated the potential protective effect of vitamin E alpha-tocopherol (α-T) isomer against the toxicity of hydrogen peroxide (HP) applied on dental pulp cells. Odontoblast-like MDPC-23 cells were seeded on 96-well plates for 72 h, treated with different concentrations of α-T (1, 3, 5, and 10 mM) for different times (1, 4, 8, and 24 h) and then exposed or not to a 0.018% HP solution for 30 min. In positive and negative control groups, cells were exposed to HP or culture medium (DMEM containing 5% DMSO), respectively. Cell viability was assessed by the MTT assay and the absorbance numeric data, expressed as percentage values, were subjected to the statistical analysis by Kruskal-Wallis and Mann-Whitney tests (α=5%). Considering the cells in the negative control as having 100% of cell viability, all combinations of α-T concentrations and pretreatment times showed a protective effect against HP cytotoxicity. Significant reduction of cell viability (59%) was observed in the positive control compared with the negative control. The highest values of pulp cell viability were obtained after pretreatment with 1 and 3 mM α-T concentrations for 24 h followed by exposure to HP (126% and 97% of cell viability, respectively). Under the tested conditions, the most effective cell protection against the cytotoxic effects of HP was provided by the lowest concentrations of α-T (1 and 3 mM) applied for 24 h.
authors.affiliation: Department of Dental Materials and Prosthodontics, Araraquara School of Dentistry, Univ Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: Fernanda da Silveira
authors.initials: Fda S
authors.lastname: Vargas
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, Univ Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: Diana Gabriela
authors.initials: DG
authors.lastname: Soares
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, Univ Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: Fernanda Gonçalves
authors.initials: FG
authors.lastname: Basso
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, Univ Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: Josimeri
authors.initials: J
authors.lastname: Hebling
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, Univ Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: Carlos Alberto de Souza
authors.initials: CA
authors.lastname: Costa
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D019610:Cytoprotection / Q000187:drug effects*; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000633:toxicity*; D051379:Mice; D009804:Odontoblasts / Q000187:drug effects; D013053:Spectrophotometry / Q000379:methods; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors; D058205:Tooth Bleaching Agents / Q000633:toxicity*; D024502:alpha-Tocopherol / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D013778:Tetrazolium Salts; D013844:Thiazoles; D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide; C022616:thiazolyl blue; D024502:alpha-Tocopherol