Experimental study on effect of arsenic trioxide on vascular smooth muscle cells

Objective: To investigate the effect of arsenic trioxide (As₂O₃) nanoparticles on rabbit vascular smooth muscle cells in vitro in comparison with normal form As₂O₃. Methods: The rabbit vascular smooth muscle cells were cultured in vitro. Nano and normal forms of As₂O₃ with drug concentrations of 3 μmol/L were added into the cells. Cell proliferation curve was drawn according to the light absorption values of MTT test. Flow cytometry was applied to observe the apoptosis. DNA was extracted and underwent electrophoresis. Results: Cell proliferation treated with the 3 μmol/L concentration of As₂O₃ was inhibited. Cell growth was inhibited markedly with increased treatment time, and the inhibition effect of nano drug form seemed stronger than that of normal form. MTT light absorption values of cells treated at 24, 48 and 72 h showed statistically significant difference (H=10.934, 15.039, 15.539, P<0.01). With flow cytometry test, the cell proliferation rates of 3 μmol/L nano drug form of As₂O₃, normal drug form of As₂O₃ and control group of cells without As₂O₃ were 44.97%, 58.54%, 74.02% respectively. The early apoptosis rates were 16.89%, 11.27%, 11.20%, late apoptosis rates were 26.56%, 23.60%, 12.46%, and necrosis rates were 11.58%, 6.59%, 2.32% respectively. Agarose gel electrophoresis showed 'ladder' strand of DNA, with more strands and obscurity for nano drug form treated cells. Conclusion: Arsenic trioxide may inhibit the growth of rabbit vascular smooth muscle cells. The nano drug form showed stronger inhibition effect than that of the normal drug form. (authors)