Effects of NO-donating oleanane derivatives on cell proliferation and apoptosis of human hepatoma cell lines

To investigate the inhibition effects of NO-donating oleanane derivative (SO-10) on human hepatoma cell lines and the antitumor activities of NO, MTT assay was used to analyze human hepatoma cells (HepG2, BEL-7402 and SMMC-7721) proliferation. SO-10 strongly inhibited human hepatoma cell proliferation and their IC₅₀ values were 1.19 ± 0.12 μmol/L for HepG2, 1.98 ± 0.85 μmol/L for BEL-7402 and 5.92 ± 0.58 μmol/L for SMMC-7721 after 48 h. Apoptosis of HepG2 cells induced by SO-10 was detected by flow cytometry (FCM), showing that SO-10 dramatically triggered apoptosis in HepG2 cells in a dose-dependent manner. The amount of NO produced by SO-10 were increased from 30 min to 6 h examined by the Griess assay. Furthermore, pre-treatment with different concentrations of hemoglobin notably reduced the concentrations of NO and inhibited the cytotoxicity of SO-10 against HepG2 cells. SO-10 showed remarkable effects of inhibiting cell proliferation and inducing apoptosis of human hepatoma cell lines. The significantly high concentrations of NO produced by SO-10 might contribute to its cytotoxicity against HepG2 cells.