Depletion of intracellular glutathione and increased lipid peroxidation mediate cytotoxicity of hematite nanoparticles in MRC-5 cells

Abstract

Particles generated from numerous anthropogenic and/or natural sources, such as crystalline α-Fe2O3 nanoparticles, have the potential to damage lung cells. In our study we investigated the effects of these nanoparticles (12.5 μg/ml) on lipid peroxidation and the antioxidative system in MRC-5 lung fibroblast cells following exposure for 24, 48 or 72 h. Exposure to α-Fe2O3 nanoparticles increased lipid peroxidation by 81 %, 189 % and 110 % after 24, 48 and 72 h, respectively. Conversely, the reduced glutathione concentration decreased by 23.2 % and 51.4 % after 48 and 72 h of treatment, respectively. In addition, an augmentation of the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione transferase and glutathione reductase within the interval between 48-72 h was noticed. Taking into account that the reduced glutathione level decreased and the malondialdehyde level, a lipid peroxidation product, remained highly increased up to 72 h of exposure, it would appear that the MRC-5 antioxidant defense mechanisms did not efficiently counteract the oxidative stress induced by exposure to hematite nanoparticles.