title: Multi wall carbon nanotubes induce oxidative stress and cytotoxicity in human embryonic kidney (HEK293) cells.
abstract: The present study was aimed at evaluating the potential toxicity and the general mechanism involved in multi wall carbon nanotubes (MWCNT)-induced cytotoxicity using human embryonic kidney cell line (HEK293) cells. Two multi wall carbon nanotubes (coded as MWCNT1, size: 90-150nm and MWCNT2, size: 60-80nm) used in this study are MWCNT1 (produced by the electric arc method and size of the nanotubes was 90-150nm) and MWCNT2 (produced by the chemical vapor deposition method with size of 60-80nm). To elucidate the possible mechanisms of MWCNT induced cytotoxicity, cell viability, mitochondrial function (MTT assay), cell membrane damage (LDH assay), reduced glutathione (GSH), interleukin-8 (IL-8) and lipid peroxidation levels were quantitatively assessed under carbon nanotubes exposed (48h) conditions. Exposure of different sizes of two carbon nanotubes at dosage levels between 3 and 300mug/ml decreased cell viability in a concentration dependent manner. The IC(50) values (concentration of nanoparticles to induce 50% cell mortality) of two (MWCNT1, MWCNT2) nanoparticles were found as 42.10 and 36.95mug/ml. Exposure of MWCNT (10-100mug/ml) to HEK cells resulted in concentration dependent cell membrane damage (as indicated by the increased levels of LDH), increased production of IL-8, increased TBARS and decreased intracellular glutathione levels. The cytotoxicity and oxidative stress was significantly more in MWCNT2 exposed cells than MWCNT1. In summary, exposure of carbon nanotubes resulted in a concentration dependent cytotoxicity in cultured HEK293 cells that was associated with increased oxidative stress.
authors.affiliation: Department of Pharmacology and Toxicology, University College of Pharmaceutical Sciences, Kakatiya University, Warangal 506 009, India.
authors.forename: Anreddy Rama Narsimha
authors.initials: AR
authors.lastname: Reddy
authors.forename: Yellu Narsimha
authors.initials: YN
authors.lastname: Reddy
authors.forename: Devarakonda Rama
authors.initials: DR
authors.lastname: Krishna
authors.forename: Vurimindi
authors.initials: V
authors.lastname: Himabindu
mesh_terms: D002244:Carbon / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003593:Cytoplasm / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008928:Mitochondria / Q000378:metabolism; D053758:Nanoparticles / Q000633:toxicity*; D037742:Nanotubes, Carbon / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D010087:Oxides / Q000378:metabolism
chemical_list: D016209:Interleukin-8; D037742:Nanotubes, Carbon; D010087:Oxides; D002244:Carbon; D007770:L-Lactate Dehydrogenase; D005978:Glutathione