title: Genotoxic effects of silver nanoparticles stimulated by oxidative stress in human normal bronchial epithelial (BEAS-2B) cells.
abstract: Many classes of silver nanoparticles (Ag-NPs) have been synthesized and widely applied, but the genotoxicity of Ag-NPs and the factors leading to genotoxicity remain unknown. Therefore, the purpose of this study is to elucidate the genotoxic effects of Ag-NPs in lung and the role of oxidative stress on the genotoxic effects of Ag-NPs. For this, Ag-NPs were completely dispersed in medium by sonication and filtration. The Ag-NPs dispersed in medium were 43-260nm in size. We observed distinct uptake of Ag-NPs into BEAS-2B cells. The Ag-NPs aggregates were wrapped with an endocytic vesicle within the cytoplasm and nucleus of BEAS-2B cells. In the comet assay and micronucleus (MN) assay for BEAS-2B cells, Ag-NPs stimulated DNA breakage and MN formation in a dose-dependent manner. The genotoxic effect of Ag-NPs was partially blocked by scavengers. In particular, of the scavengers tested, superoxide dismutase most significantly blocked the genotoxic effects in both the cytokinesis-block MN assay and the comet assay. In the modified comet assay, Ag-NPs induced a significant increase in oxidative DNA damage. Furthermore, in the oxidative stress assay, Ag-NPs significantly increased the reactive oxygen radicals. These results suggest that Ag-NPs have genotoxic effects in BEAS-2B cells and that oxidative stress stimulated by Ag-NPs may be an important factor in their genotoxic effects.
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do, South Korea.
authors.forename: Ha Ryong
authors.initials: HR
authors.lastname: Kim
authors.forename: Mi Jie
authors.initials: MJ
authors.lastname: Kim
authors.forename: Soo Yeun
authors.initials: SY
authors.lastname: Lee
authors.forename: Seung Min
authors.initials: SM
authors.lastname: Oh
authors.forename: Kyu Hyuck
authors.initials: KH
authors.lastname: Chung
mesh_terms: D001980:Bronchi / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage; D006801:Humans; D053768:Metal Nanoparticles / Q000633:toxicity*; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species; D020545:Respiratory Mucosa / Q000187:drug effects*; D012834:Silver / Q000008:administration & dosage / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D009153:Mutagens; D017382:Reactive Oxygen Species; D012834:Silver; D013482:Superoxide Dismutase