Abstract
Cadmium sulfide nanoparticles (CdSNP) are increasingly used in biological applications. This study was undertaken to understand the mechanisms underlying adverse effects of CdSNP using human lung adenocarcinoma epithelial (A549) cells. Cellular toxicity was evaluated by using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide and neutral red assays. Results showed that CdSNP reduced mitochondrial function and induced lysosomal activity in concentration and time-dependent manner. CdSNP produced oxidative stress as evidenced by reduction of glutathione (GSH) levels and increase in reactive oxygen species and lipid peroxidation levels. Induction of caspase-3 enzymes and condensed, fragmented nuclei was observed in CdSNP-treated cells. Furthermore, the levels of interleukin-8, tumor growth factor and DNA fragmentation were significantly higher in CdSNP exposed cells. Data indicated that toxicity of CdSNP noted in A549 cells may be mediated through oxidative stress. This study warrants more comprehensive assessment of CdSNP prior to industrial applications.