title: [Effect of Ca(OH)2 on the cytotoxicity of lipopolysaccharide extracted from Porphyromonas endodontalis in vitro].
abstract: OBJECTIVE
  To detect the degradation of Ca(OH)2 on lipopolysaccharide (LPS) extracted from Porphyromonas endodontalis (P.e) in vitro and estimate the influence of P.e LPS pretreated with Ca(OH)2 on the proliferation of MC3T3-E1 cells.
  
  
  METHODS
  The effect of Ca(OH)2 on MC3T3-E1 cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) assay. Then P.e LPS was treated with Ca(OH)2 for 30 mins or 60 mins at 37 degrees centigrade in vitro and the activity of P.e LPS was evaluated by Chromogenic End-point Tachypleus Amebocyte Lysate (CE TAL) test. Finally, MC3T3-E1 cells were exposed to P.e LPS pretreated with 15% Ca(OH)2 for 1, 3 and 5 d, and the cell proliferation was measured using the MTT assay comparing with the P.e LPS control group. SPSS 13.0 software package was used for statistical analysis.
  
  
  RESULTS
  Compared with the negative control, exposing cells to 5%, 10% and 15% Ca(OH)2 had greatly promoted MC3T3-E1 cell proliferation. P.e LPS treated with 10% and 15% Ca(OH)2 both presented the best results by CE TAL and significant difference compared with P.e LPS control group. When 10 μg/mL P.e LPS was pretreated with 15% Ca(OH)2, no inhibition of MC3T3-E1 cell proliferation was noted.
  
  
  CONCLUSIONS
  Ca(OH)2 detoxifies P.e LPS in vitro, mitigates the impact of P.e LPS on MC3T3-E1 cell proliferation. Supported by Science and Technology Projects of Liaoning Province (2011225020).
authors.affiliation: Department of Endodontics,College of Stomatology, China Medical University;Shenyang 110002, Liaoning Province, China.E-mail:jiajieguo@hotmail.com.
authors.forename: Jia-jie
authors.initials: JJ
authors.lastname: Guo
authors.forename: Li-hong
authors.initials: LH
authors.lastname: Qiu
authors.forename: Ya-qiong
authors.initials: YQ
authors.lastname: Yu
authors.forename: Li-ya
authors.initials: LY
authors.lastname: Xu
authors.forename: Yun-qian
authors.initials: YQ
authors.lastname: Fan
authors.forename: Ming
authors.initials: M
authors.lastname: Zhong
mesh_terms: D002126:Calcium Hydroxide; D049109:Cell Proliferation; D066298:In Vitro Techniques; D008070:Lipopolysaccharides; D010006:Osteoblasts; D045202:Porphyromonas endodontalis
chemical_list: D008070:Lipopolysaccharides; D002126:Calcium Hydroxide