title: Effect of hydrogen-peroxide-mediated oxidative stress on human dental pulp cells.
abstract: OBJECTIVE
  To evaluate the effect of the oxidative stress on human dental pulp cells (HDPCs) promoted by toxic concentrations of hydrogen peroxide (H2O2) on its odontoblastic differentiation capability through time.
  
  
  METHODS
  HDPCs were exposed to two different concentrations of H2O2 (0.1 and 0.3μg/ml) for 30min. Thereafter, cell viability (MTT assay) and oxidative stress generation (H2DCFDA fluorescence assay) were immediately evaluated. Data were compared with those for alkaline phosphatase (ALP) activity (thymolphthalein assay) and mineralized nodule deposition (alizarin red) by HDPCs cultured for 7 days in osteogenic medium.
  
  
  RESULTS
  A significant reduction in cell viability and oxidative stress generation occurred in the H2O2-treated cells when compared with negative controls (no treatment), in a concentration-dependent fashion. Seven days after H2O2 treatment, the cells showed significant reduction in ALP activity compared with negative control and no mineralized nodule deposition.
  
  
  CONCLUSIONS
  Both concentrations of H2O2 were toxic to the cells, causing intense cellular oxidative stress, which interfered with the odontogenic differentiation capability of the HDPCs.
  
  
  CONCLUSIONS
  The intense oxidative stress on HDPCs mediated by H2O2 at toxic concentrations promotes intense reduction on odontoblastic differentiation capability in a 7-day evaluation period, which may alter the initial pulp healing capability in the in vivo situation.
authors.affiliation: Department of Dental Materials and Prosthodontics, Univ. Estadual Paulista - UNESP, Araraquara School of Dentistry, Araraquara, SP, Brazil.
authors.forename: Diana Gabriela
authors.initials: DG
authors.lastname: Soares
authors.affiliation: Department of Physiology and Pathology, Univ. Estadual Paulista - UNESP, Araraquara School of Dentistry, Araraquara, SP, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Gonçalves Basso
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, Univ. Estadual Paulista - UNESP, Araraquara School of Dentistry, Araraquara, SP, Brazil.
authors.forename: Josimeri
authors.initials: J
authors.lastname: Hebling
authors.affiliation: Department of Physiology and Pathology, Univ. Estadual Paulista - UNESP, Araraquara School of Dentistry, Araraquara, SP, Brazil. Electronic address: casouzac@foar.unesp.br.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Souza Costa
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology / Q000000981:diagnostic imaging / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D009804:Odontoblasts / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D006861:Hydrogen Peroxide
keywords: Hydrogen peroxide; Pulp cells; Toxicity