Effects of magnetic nanoparticles of Fe3O4 combinated with gambogic acid on apoptosis of SMMC-7721 cells

This study aims to investigate the potential benefit of combination therapy with magnetic nanoparticles of Fe3O4 (Fe3O4-MNP) and gambogic acid (GA) on SMMC-7721 cells. The inhibition of proliferation of SMMC-7721 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was calculated and analyzed by flow cytometry, and the expressions of the apoptosis-related protein were detected by Western blot. GA enhanced the cytotoxicity of SMMC-7721 cells in a dose-dependent manner. The Fe3O4-MNP itself had no obviously inhibitory effect, but it could enhance the effect of GA on proliferation of SMMC-7721 cells. The apoptotic rate of SMMC-7721 cells induced by combination of GA with Fe3O4-MNP was higher than that by GA alone. The expression levels of caspase-3 and caspase-8 after co-treatment of GA and Fe3O4-MNP were higher than that exposed to either GA or Fe3O4-MNP alone, while the levels of bcl-2 were downregulated. Fe3O4-MNP can promote GA-induced apoptosis of SMMC-7721 cells, which may be related to the downregulation of Bcl-2 and upregulation of caspase-3.