title: Interaction between dental metals and antioxidants, assessed by cytotoxicity assay and ESR spectroscopy.
abstract: Among dental metals, copper showed the highest cytotoxicity against human oral squamous cell carcinoma and human submandibular gland carcinoma cells, followed by palladium-alloy, gold and silver. Normal human cells (gingival fibroblast, pulp cells, periodontal ligament fibroblast) were relatively resistant to these metals. The palladium-alloy failed to induce internucleosomal DNA fragmentation, a biochemical hallmark of apoptosis, in human promyelocytic leukemic HL-60 cells. The cytotoxic activity of the palladium-alloy was significantly reduced by a non-cytotoxic concentration of N-acetyl-L-cysteine, or more efficiently by sodium ascorbate. However, higher concentrations of sodium ascorbate enhanced the cytotoxic activity of palladium-alloy. ESR spectroscopy showed that the palladium-alloy enhanced the intensity of ascorbate radical, suggesting the possible interaction between metals and antioxidants. All metals, except copper, did not significantly affect the generation of superoxide anion (by hypoxanthine-xanthine oxidase reaction), hydroxyl radical (by Fenton reaction) and nitric oxide (from NOC-7 in the presence of C-PTIO). These data demonstrate for the first time that antioxidants modify the biological activity of dental metals.
authors.affiliation: Department of Operative Dentistry, Meikai University School of Dentistry, Saitama, Japan. sakagami@dent.meikai.ac.jp
authors.forename: Naoto
authors.initials: N
authors.lastname: Kinoshita
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yamamura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Teranuma
authors.forename: Tadashi
authors.initials: T
authors.lastname: Katayama
authors.forename: Mikako
authors.initials: M
authors.lastname: Tamanyu
authors.forename: Takaharu
authors.initials: T
authors.lastname: Negoro
authors.forename: Kazue
authors.initials: K
authors.lastname: Satoh
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy; D003300:Copper / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D003764:Dental Materials / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004347:Drug Interactions; D004578:Electron Spin Resonance Spectroscopy; D005347:Fibroblasts / Q000187:drug effects; D005609:Free Radicals / Q000737:chemistry / Q000378:metabolism; D005881:Gingiva / Q000166:cytology / Q000187:drug effects; D006046:Gold / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D018922:HL-60 Cells / Q000187:drug effects; D006801:Humans; D019271:Hypoxanthine / Q000737:chemistry / Q000378:metabolism; D008670:Metals / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D009062:Mouth Neoplasms / Q000188:drug therapy; D010165:Palladium / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism; D012834:Silver / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D013365:Submandibular Gland Neoplasms / Q000188:drug therapy; D014407:Tumor Cells, Cultured; D014969:Xanthine Oxidase / Q000737:chemistry / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003764:Dental Materials; D005609:Free Radicals; D008670:Metals; D017382:Reactive Oxygen Species; D019271:Hypoxanthine; D012834:Silver; D010165:Palladium; D006046:Gold; D003300:Copper; D014969:Xanthine Oxidase; D001205:Ascorbic Acid