Figure 1.

NBT suppresses cell growth and affects cell cycle in vitro. (A) Chemical structure of NBT. (B) Cytotoxicity effects of NBT on seven tumor cell lines. Cells were treated with NBT (0–10 μM) for 24, 48, 72 h. Cell proliferation was measured by the MTT assay. The IC₅₀ values are reported as the means ± SD from three independent experiments. (C) HeLa cells treated with different concentrations of NBT for 24 h or for different time periods as indicated were analyzed by flow cytometry to determine cell cycle distribution. (D) HeLa cells were treated with NBT (5 μM) for varying amounts of time (2, 4, 6, 8, and 10 h), and the cell cycle-related proteins in the samples were analyzed by western blotting (GAPDH as loading control).