title: Prevention of the epoxy resin-based root canal sealers-induced cyclooxygenase-2 expression and cytotoxicity of human osteoblastic cells by various antioxidants.
abstract: Cyclooxygenase-2 (COX-2) is an inducible enzyme believed to be responsible for prostaglandin synthesis at the site of inflammation. Recently, the activation of COX-2 expression may be one of the important pathogenesis of root canal sealers-induced periapical inflammation. However, little is known about whether chemical interaction can modulate the epoxy resin-based root canal sealers-induced cytotoxicity as well as COX-2 expression. The aim of the present study was to investigate the effects of antioxidants catalase, superoxide dismutase (SOD), and N-acetyl-L-cysteine (NAC) on AH26- and Topseal-induced COX-2 mRNA gene and cytotoxicity in human osteoblastic cell line U2OS cells. The results showed that both epoxy resin-based root canal sealers were cytotoxic to U2OS cells in a concentration-dependent manner (p<0.05). AH26 and Topseal were found to induce COX-2 mRNA gene expression in U2OS cells. The addition of glutathione (GSH) precursor NAC led to decrease the induction of COX-2 mRNA gene expression and cytotoxicity by both AH26 and Topseal (p<0.05). However, catalase and SOD lacked the ability to prevent AH26-and Topseal-induced cytotoxicity and COX-2 mRNA gene expression (p>0.05). Taken together, the activation of COX-2 mRNA gene expression may be one of the pathogenesis of epoxy resin-based root canal sealers-induced periapical inflammation. In addition, GSH depletion, but not the attack of oxygen free radicals, could be the mechanism for epoxy resin-based root canal sealers-induced cytotoxicity and COX-2 mRNA gene expression. Factors that induce GSH synthesis may appear useful in preventing cell damage mediated by epoxy resin-based root canal sealers.
authors.affiliation: Department of Prosthodontics, Oral Medicine Center, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Fu-Mei
authors.initials: FM
authors.lastname: Huang
authors.forename: Yu-Chao
authors.initials: YC
authors.lastname: Chang
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage*; D017209:Apoptosis / Q000187:drug effects; D001729:Bismuth / Q000009:adverse effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004347:Drug Interactions; D004853:Epoxy Resins / Q000009:adverse effects*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D008422:Materials Testing; D008565:Membrane Proteins; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects / Q000378:metabolism*; D012387:Root Canal Filling Materials / Q000009:adverse effects*; D012834:Silver / Q000009:adverse effects*; D014025:Titanium / Q000009:adverse effects*
chemical_list: D000975:Antioxidants; D004338:Drug Combinations; D004853:Epoxy Resins; D008565:Membrane Proteins; D012387:Root Canal Filling Materials; C115110:Topseal; D012834:Silver; C028044:epoxy resin AH-26; D014025:Titanium; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D001729:Bismuth