Background: Single-walled carbon nanotubes (SWCNTs) have been reported to
induce cytotoxicity in different cell lines. Although the mechanisms
underlying cytotoxicity are not fully understood, accumulation of reactive
oxygen species (ROS) and oxidative damage is considered to be a likely
contributing factor. Methods: Human lung carcinoma cells, A549, and human
fetal lung fibroblasts, MRC-5 were used to assess the cytotoxicity of SWCNT
in the presence and absence of a redox status regulator, N-acetylcysteine
(NAC), via the MTT assay. Results: SWCNT induced a nearly three-fold greater
loss of viability in A594 vs. MRC-5 cells at ?250 ?g/ml. SWCNT cytotoxicity
at higher concentrations was similar for both cell lines, while NAC alone was
non-toxic. The cytotoxicity of SWCNT (250 ?g/ml) in combination with NAC to
A549 cells was significantly decreased at the lowest NAC concentration (1.5
?g/ml), and was similar to NAC treatment alone at that concentration. Higher
concentrations of NAC in combination with SWCNT (250 ?g/ml) resulted in
increased cytotoxicity in both A549 and MRC-5 cells. Conclusion: A549
malignant lung cells are more susceptible to low concentrations of SWCNT vs.
normal lung cells, and low concentrations of N-acetylcysteine appear to be
cytoprotective, possibly due to its antioxidant properties.
Cytotoxicity of single-walled carbon nanotubes to human lung carcinoma cells: The influence of N-acetylcysteine
