title: Multi-walled carbon nanotubes induce oxidative stress and apoptosis in human lung cancer cell line-A549.
abstract: Multi-walled carbon-nanotubes (MWCNTs)-induced apoptotic changes were studied in human lung epithelium cell line-A549. Non-cytotoxic doses of MWCNTs were identified using tetrazolium bromide salt (MTT) and lactate dehydrogenase (LDH) release assays. Cells were exposed to MWCNTs (0.5-100 μg/ml) for 6-72 h. Internalization and characterization of CNTs was performed by electron microscopy. Apoptotic changes were estimated by nuclear condensation, DNA laddering, and confirmed by expression of associated markers: p(53), p(21WAF1/CIP1), Bax, Bcl(2) and activated caspase-3. MWCNTs induced the production of reactive oxygen species and malondialdehyde along with significant decrease in the activity of catalase and glutathione. MWCNTs-induced ROS generation was found not to be associated with the mitochondrial activity. In general, the changes were significant at 10 and 50 μg/ml only. Results indicate the involvement of oxidative stress and apoptosis in A549 cells exposed to MWCNTs. Our studies provide insights of the mechanisms involved in MWCNTs-induced apoptosis at cellular level.
authors.affiliation: Indian Institute of Toxicology Research, Lucknow, India.
authors.forename: Ritesh K
authors.initials: RK
authors.lastname: Srivastava
authors.forename: Aditya B
authors.initials: AB
authors.lastname: Pant
authors.forename: Mahendra P
authors.initials: MP
authors.lastname: Kashyap
authors.forename: Vivek
authors.initials: V
authors.lastname: Kumar
authors.forename: Mohathshim
authors.initials: M
authors.lastname: Lohani
authors.forename: Ludwig
authors.initials: L
authors.lastname: Jonas
authors.forename: Qamar
authors.initials: Q
authors.lastname: Rahman
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015415:Biomarkers / Q000378:metabolism; D045744:Cell Line, Tumor / Q000187:drug effects*; D006801:Humans; D008175:Lung Neoplasms; D008928:Mitochondria / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000009:adverse effects* / Q000648:ultrastructure; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012402:Rotenone / Q000378:metabolism; D014475:Uncoupling Agents / Q000378:metabolism
chemical_list: D015415:Biomarkers; D037742:Nanotubes, Carbon; D017382:Reactive Oxygen Species; D014475:Uncoupling Agents; D012402:Rotenone