Dose-dependent genotoxicity of copper oxide nanoparticles stimulated by reactive oxygen species in human lung epithelial cells

Abstract

Copper oxide nanoparticles (CuO NPs) are of great interest in nanoscience and nanotechnology because of their broad industrial and commercial applications. Therefore, toxicity of CuO NPs needs to be thoroughly understood. The aim of this study was to investigate the cytotoxicity, genotoxicity, and oxidative stress induced by CuO NPs in human lung epithelial (A549) cells. CuO NPs were synthesized by solvothermal method and the size of NPs measured under transmission electron microscopy (TEM) was found to be around 23 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) and lactate dehydrogenase (LDH) assays showed that CuO NPs (5-15 µg/ml) exert cytotoxicity in A549 cells in a dose-dependent manner. Comet assay suggested concentration-dependent induction of DNA damage due to the exposure to CuO NPs. The comet tail moment was 27% at 15 µg/ml of CuO NPs, whereas it was 5% in control (p < 0.05). The flow cytometry data revealed that CuO NPs induced micronuclei (MN) in A549 cells dose dependently. The frequency of MN was 25/10(3) cells at 15 µg/ml of CuO NPs, whereas it was 2/10(3) cells for control. CuO NPs were also found to induce oxidative stress in a concentration-dependent manner, which was indicated by induction of reactive oxygen species (ROS) and lipid peroxidation along with glutathione depletion. Moreover, MN induction and DNA damage were significantly correlated with ROS (R(2) = 0.937 for ROS vs. olive tail moment, and R(2) = 0.944 for ROS vs. MN). Taken together, this study suggested that CuO NPs induce genotoxicity in A549 cells, which is likely to be mediated through ROS generation and oxidative stress.

Copper Oxide Nanoparticles Stimulate Glycolytic Flux and Increase the Cellular Contents of Glutathione and Metallothioneins in Cultured Astrocytes

“…Studies on astrocytes [17] and other cell types [12,13,[49][50][51][52] revealed that CuO-NP-treated cells suffer from an increased formation of cellular ROS. For astrocytes, elevated ROS levels and toxicity were prevented by coapplication of the membrane-permeable copper chelator TTM, suggesting that copper ions which have been liberated from the accumulated CuO-NPs are responsible for the ROS-induced toxicity [17].…”

Assessment of the Lung Toxicity of Copper Oxide Nanoparticles: Current Status

“…Our previous study also demonstrated that CuO NPs (average size: 53 nm) regulated the genes involved in DNA damage and apoptosis (e.g., Hsp70, p53, Rad51 and MSH2) [34]. Another recent study from our group observed that CuO NPs (average size: 23 nm) induced dose-dependent (5-15 μg/ml) cytotoxicity, DNA damage (comet assay) and micronuclei induction in A549 cells [35].…”

“…Once the NPs were introduced to aqueous media, the sizes changed to often times higher than those of the primary size [33]. For example, our previous studies have shown that, once CuO NPs are introduced into cell culture media, their hydrodynamic sizes changed to around ten-times higher than those observed from CuO nanopowder [34,35]. The higher size of CuO NPs in aqueous suspension compared with the primary size of dry powder might be due to the tendency of particles to agglomerate in an aqueous state.…”

Some inferences from in vivo experiments with metal and metal oxide nanoparticles: the pulmonary phagocytosis response, subchronic systemic toxicity and genotoxicity, regulatory proposals, searching for bioprotectors (a self-overview)

“…[1][2][3][4][5][6][7][8][9][10] Although in the vast nanotoxicological literature of the last decade studies concerned with the assessment of metal or metal-oxide NP toxicity are not at the top of the list, such publications are nevertheless quite numerous. To illustrate this, we may refer to several works devoted to NPs of the metals that were the subject-matter of our own studies considered below: iron oxide, [11][12][13][14][15][16][17][18][19][20] silver, gold, 24,[45][46][47][48][49][50][51][52][53][54][55][56][57][58] copper and copper oxide, 43,[59][60][61][62][63][64][65][66][67][68] nickel oxide, 65,[69]…”