Objective To investigate the effect of single-walled carbon nanotubes (SWCNTs) on oxidative stress and apoptosis of human bronchial epithelial cell line (BEAS-2B).
Methods BEAS-2B cells were cultured with 0, 10, 50, 100, and 200 μg/mL SWCNTs separately for 24 h and 48 h. The viability of BEAS-2B cells was detected by tetrazolium (MTT) assay; the generation of reactive oxygen species (ROS) was detected by fluorescent probe (DCFH-DA), the enzymatic activity of super oxide dismutase (SOD) was detected by xanthine oxidase method; the enzymatic activity of catalase (CAT) was detected by visible spectrophotometry; the content of malondialdehyde (MDA) was determined by thiobarbituric acid (TBA); the enzymatic activity of glutathione peroxidase (GSH-Px) was determined by dithio nitrobenzoic acid (DTNB); the mitochondrial membrane potential was determined by cationic fluorescent dye rhodamine 123; the intracellular caspase-3 protein activity was determined by pNA assay; the mRNA levels of bax and bcl-2 were determined using reverse transtription polymerase chain reaction (RT-PCR).
Results When the concentration of SWCNTs was more than 10 μg/mL, the viability of BEAS-2B cells declined, the levels of intracellular ROS increased, the mitochondrial membrane potential declined, the lipid peroxidation product (MDA) increased, the activities of antioxidant enzymes (SOD, CAT, GSH-Px) reduced, the protein activity of caspase-3 increased, the expression of bax mRNA in creased while the bcl-2 mRNA reduced. All the results were exhibited in a dose-response manner (P<0.05).
Conclusion SWCNTs could induce oxidative stress and apoptosis in BEAS-2B cells.
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