Abstract: The purpose of this study was to explore the mechanism by which hawthorn proanthocyanidins (HPC) inhibit cell proliferation and promote apoptosis in Huh-7 cells. Huh-7 cells and Traf6-overexpressed Huh-7 cells were cultured routinely at HPC concentrations of 0, 5, 10, 20, 40 and 80 μg/mL. Cell counting kit-8 (CCK-8) was used to detect the inhibitory effect of HPC on the proliferation of Huh-7 cells and Traf6-overexpressed Huh-7 cells. The mRNA expression of the tumor necrosis factor receptor associated factor 6 (Traf6), nuclear factor kappa-B p65 (NF-κB p65), Bax and caspase-3 genes were evaluated by real-time polymerase chain reaction (PCR). The protein expression of Traf6, NF-κB p65, Bax and caspase-3 were tested by Western blotting. Double staining with Annexin V-FITC and propidium iodide (PI) was used to test and calculate the apoptosis of Huh-7 cells. Treatment with HPC at concentrations higher than 20 μg/mL could inhibit Huh-7 cell proliferation in a dose-dependent way (P < 0.05). The over-expression of Traf6 promoted the proliferation of Huh-7 cells．Compared with the control group, HPC at 40 μg/mL significantly decreased the relative mRNA and protein expression of Traf6 and NF-κB p65 (P < 0.05), increased the relative mRNA and protein expression of Bax and caspase-3 (P < 0.05), and promoted Huh-7 cell apoptosis (P < 0.05). We concluded that HPC induce apoptosis in Huh-7 cells by down-regulating the Traf6/NF-κB signaling pathway.

Key words: hawthorn proanthocyanidin; hepatocellular carcioma; tumor necrosis factor receptor associated factor 6; nuclear factor kappa B; cell apoptosis