Single-Walled Carbon Nanotubes Induces Oxidative Stress in Rat Lung Epithelial Cells

Molecular Neurotoxicology Laboratory/Proteomics Core, Department of Biology, Texas Southern University, Houston, TX 77004, USA.
Journal of Nanoscience and Nanotechnology (Impact Factor: 1.34). 08/2007; 7(7):2466-72. DOI: 10.1166/jnn.2007.431
Source: PubMed

ABSTRACT Single-walled carbon nanotubes (SWCNT) show unique properties find applications in micro devices; electronics to biological systems specially drug delivery and gene therapy. However the manufacture and extensive use of nanotubes raises concern about its safe use and human health. Very few studies have been carried out on toxicity of carbon nanotubes in experimental animals and humans, thus resulted in limiting their use. The extensive toxicological studies using in vitro and in vivo models are necessary and are required to establish safe manufacturing guidelines and also the use of SWCNT. These studies also help the chemists to prepare derivative of SWCNT with less or no toxicity. The present study was undertaken to determine the toxicity exhibited by SWCNT in rat lung epithelial cells as a model system. Lung epithelial cells (LE cells) were cultured with or without SWCNT and reactive oxygen species (ROS) produced were measured by change in fluorescence using dichloro fluorescein (DCF). The results show increased ROS on exposure to SWCNT in a dose and time dependent manner. The decrease in glutathione content suggested the depletion and loss of protective mechanism against ROS in SWCNT treated cells. Use of rotenone, the inhibitor of mitochondrial function have no effect on ROS levels suggested that mitochondria is not involved in SWCNT induced ROS production. Studies carried out on the effect of SWCNT on superoxide dismutase (SOD-1 and SOD-2) levels in LE cells, indicates that these enzyme levels decreased by 24 hours. The increased ROS induced by SWCNT on LE cells decreased by treating the cells with 1 mM of glutathione, N-Acetyl Cysteine, and Vitamin C. These results further prove that SWCNT induces oxidative stress in LE cells and shows loss of antioxidants.

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Available from: Renard L. Thomas, Mar 25, 2015
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    • "The toxicological concern is as a result of their fibrous shape and durability, along with their proved capacity to generate free radicals (Patlolla et al., 2011; Ye et al., 2011) and to activate signaling pathways involved in cell growth control (Valko et al., 2006). Previous studies have shown that multi-walled carbon nanotubes can produce cytotoxic, genotoxic and apoptotic effects not only on different cell lines (Murray et al., 2009; Patlolla et al., 2010; Sharma et al., 2007), but also after pulmonary (Muller et al., 2005) or skin administration (Murray et al., 2009; Park et al., 2011). However, the results of the studies performed during the past years in order to explore the potential toxic effects of CNT have shown their dependence on the type, surface geometry, diameter, length and functionalization. "
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    ABSTRACT: In recent years, a great deal of studies have focused on the possible toxicity of carbon nanotubes (CNT), as a result of their potential applications in the field of nanotechnologies. The investigation of spleen toxicity is part of the carbon nanotubes-induced toxicity assessment. In this study, we investigated the possible toxic effects of CNT on the rat spleen, after intraperitoneally (i.p.) administration of a single dose [1.5 ml; 2 mg multi-walled (MW) CNT per body weight (bw)] of multi-walled carbon nanotubes (exterior diameter 15-25 nm, interior diameter 10-15 nm, surface 88 m(2) g(-1) ) functionalized 1:1 with single-strand DNA (ss-DNA-MWCNT, 270 mg l(-1) ). CNT functionalization with DNA determines a stable dispersion in the body fluids. For the detection of carbon nanotubes in the spleen, Raman spectroscopy, histopathologic examination, confocal microscopy and transmission electron microscopy (TEM) were performed at different time points (1, 6, 24, 48 and 144 h) after MWCNT administration. The dynamics of oxidative stress parameters (malondialdehyde, protein carbonyls and reduced glutathione), along with nitrosative stress parameters (nitric oxide, inducible NO synthase), the pro-inflammatory cytokines [interleukin-(IL)-1β] and the number of cells expressing caspase 3 and proliferating cell nuclear antigen (PCNA) were assessed. Our results indicate that, after i.p. administration, MWCNT translocate progressively in the spleen, with a peak of concentration after 48 h, and determine lymphoid hyperplasia and an increase in the number of cells which undergo apoptosis, in parallel with the enhancement of the mitosis in the white pulp and with transient alterations of oxidative stress and inflammation that need further investigations for a longer period of monitoring. Copyright © 2013 John Wiley & Sons, Ltd.
    Journal of Applied Toxicology 04/2014; 34(4). DOI:10.1002/jat.2883 · 3.17 Impact Factor
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    • "It has been previously reported that genotoxicity effects can result from the direct interaction of nanoparticles with genetic material or secondary damage resulting from particle-induced reactive oxygen species production (Kisin et al., 2011). According to the recent in vitro studies, SWCNTs and MWCNTs induce ROS production in mammalian cells (Sharma et al., 2007; Shvedova et al., 2003; Ye et al., 2009, 2011). In a previous in vivo 5-day inhalation study by the current authors, a 2.57 mm average tube length induced an increased concentration of intracellular H 2 O 2 with a similar trend of DNA damage (Kim et al., 2012b). "
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    • "The most prevalent exposures include: inhalation in the workplace and through significantly contaminated air, ingestion of water or food, and dermal contact, primarily through the application of personal care products. Current literature using both mammalian models in vivo and human cell lines in vitro has evaluated potential human health risks of NMs and has shown an increased possibility of oxidative stress (Sharma et al., 2007), lipid peroxidation (Sayes et al., 2005), genotoxicity (Dhawan et al., 2006), lung disease (Heinrich et al., 1995; Lam et al., 2004; Shvedova et al., 2005), inflammation (Balbus et al., 2007; Bermudez et al., 2004), and adverse effects on the human immune system (Bermudez et al., 2004; Tinkle et al., 2003). "
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