title: Mechanisms of cytotoxicity of eugenol in human osteoblastic cells in vitro.
abstract: OBJECTIVE
  To evaluate the mechanisms of cytotoxicity of eugenol in human osteoblastic cells in vitro.
  
  
  METHODS
  Cytotoxicity and cell proliferation assays were performed to elucidate the toxic effects of eugenol on the human osteoblastic cell line U2OS. Furthermore, the effects of antioxidants catalase (scavenger of H2O2), superoxide dismutase (SOD, an extracellular superoxide free radical scavenger) and N-acetyl-L-cysteine (NAC, a cell-permeable glutathione precursor) were added to discover the possible mechanisms of eugenol-induced cytotoxicity. Paired Student's t-test was applied for the statistical analysis of the results.
  
  
  RESULTS
  Eugenol demonstrated a cytotoxic effect to U2OS cells in a dose-dependent manner (P < 0.05). The 50% inhibition concentration of eugenol was approximately 0.75 mmol L(-1). Eugenol also inhibited cell proliferation during a 4-day culture period (P < 0.05). Addition of NAC extracellularly protected the cells from eugenol-induced cytotoxicity (P < 0.05). Neither, SOD nor catalase provided any protective effects on eugenol-induced cytotoxicity (P > 0.05).
  
  
  CONCLUSIONS
  The levels of eugenol tested inhibited growth and proliferation of U2OS cells. Eugenol has significant potential for periapical toxicity. These inhibitory effects were associated with glutathione levels.
authors.affiliation: School of Applied Chemistry, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Y-C
authors.initials: YC
authors.lastname: Ho
authors.forename: F-M
authors.initials: FM
authors.lastname: Huang
authors.forename: Y-C
authors.initials: YC
authors.lastname: Chang
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D003764:Dental Materials / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005054:Eugenol / Q000633:toxicity*; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D008422:Materials Testing; D010006:Osteoblasts / Q000187:drug effects*; D020011:Protective Agents / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000975:Antioxidants; D003764:Dental Materials; D016166:Free Radical Scavengers; D020011:Protective Agents; D005054:Eugenol; D002374:Catalase; D013482:Superoxide Dismutase; D000111:Acetylcysteine