Abstract: Objective: To investigate the effect of hawthorn proanthocyanidins extract, epicatechin and proanthocyanidin B2 on the proliferation and apoptosis of human hepatocellular carcinoma SMMC-7721 cells. Methods: SMMC-7721 cells were cultured in vitro. The effect of different concentrations of hawthorn proanthocyanidins on cell proliferation and apoptosis was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay and 4’,6-diamidino-2-phenylindole (DAPI) staining, respectively. The expression of apoptosis-related proteins was detected by Western blotting. The activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and Na+K+-ATPase and malondialdehyde (MDA) level in cells from each group were determined. Results: Hawthorn proanthocyanidins extract, epicatechin and proanthocyanidin B2 all significantly inhibited the proliferation of SMMC-7721 cells in a time-dependent and concentrationdependent manner (P < 0.05) and induced cell apoptosis. Compared with the control group, hawthorn proanthocyanidins extract, epicatechin and proanthocyanidin B2 decreased the activity of SOD, CAT, GSH-Px and Na+K+-ATPase and increased the level of MDA in SMMC-7721 cells. The expression of apoptosis-related proteins casepase-8, caspase-3, Bcl-2-associated X protein and the fragment of poly (ADP-ribose) polymerase were increased, while the expression of Bcl-2 was decreased. Conclusion: Hawthorn proanthocyanidins can inhibit the proliferation of SMMC-7721 cells and induce apoptosis through regulating antioxidant activity and apoptosis-related proteins.

Key words: hawthorn proanthocyanidins, antioxidant activity, human hepatocellular carcinoma SMMC-7721 cells, cell proliferation, cell apoptosis