白花蛇舌草总黄酮对肝癌的体内外抑制作用及对小鼠移植性肝癌H22细胞增殖周期、凋亡、免疫环境的影响

AIM: To investigate the inhibitory effect of favonoids from Hedyotis diffusa willd, (FHD) on human hepatoma cell line SMMC-7721 and BEL-7402 in vitro, the antitumor effect on transplanted H22 tumor cells in vivo and its influence on the proliferation cycle, apoptosis of tumor cells and immune circumstances. METHODS: MTT assay was used to measure the inhibition of SMMC-7721 and BEL-7402 cells exposing to 0, 5, 10, 50 and 100 mg/L FHD for 24, 48 and 72 hours. Sixty Kunming mice were randomly and averagely divided into 6 groups. Except those in normal control group, the other mice received inoculation of H22 tumor cells, and then treated with normal saline, 5-fluorouracil (30 mg/kg), and FHD (25, 50, 100 mg/kg), respectively, for 10 days. The following indicators were compared among the 6 groups, including the inhibitory rates of tumor weights, the distribution of H22 cell cycle, the apoptosis of H22 cells, the thymus index (×10^(-3)) and splenic index (×10^(-3)) in mice bearing H22 tumors, the splenic lymphocyte transformation efficiency, and the serum levels (ng/L) of tumor necrosis factor (TNF-α) and interferon-γ (IFN-γ). RESULTS: FHD inhibited the proliferation of SMMC-7721 and BEL-7402 cells in vitro in a dose- and time-dependent manner. In comparison with those in the model control mice, when FHD was used at the concentrations of 25, 50 and 100 mg/kg, the growth of H22 tumors was obviously restrained (P＜0.01); the proportion of G0/G1-phase cells was increased (30.36%±5.72%, 32.83%±6.67%, 39.67%±8.01% vs 25.62%±4.36%, P＜0.05 or P＜0.01), while that of G2/M-phase cells was decreased (7.65%±2.32%, 6.33%±3.43%, 2.22%±0.98% vs 11.13%±2.77%, P＜0.05 or P＜0.01); the apoptosis of tumor cells was significantly promoted (2.41%±0.42%, 2.22%±0.33%, 2.07%±0.40% vs 1.47%±0.66%, P＜0.01); the splenic index was down-regulated (51.43±8.31, 47.43±7.89, 48.64±9.35 vs 67.63±7.44, P＜0.01), but the thymus index (33.36±4.09, 40.35±5.79, 34.57±6.56 vs 22.43±4.52, P＜0.01), the splenic lymphocyte transformation rate (10.83%±3.75%, 11.33%±5.04%, 13.58%±4.62% vs 9.35%±2.02%, P＜0.05), and the serum levels of TNF-α (257.56±42.29, 386.36±25.97, 364.52±23.62 vs 101.43±24.72, P＜0.01) and IFN-γ (355.83±35.74, 392.31±25.17, 357.38±34.82 vs 172.35±29.02, P＜0.01) were markedly elevated. CONCLUSION: FHD has inhibitory effect on hepatoma cells both in vivo and in vitro, which is related to the blocking of tumor cell proliferation cycle, promotion of tumor cell apoptosis and regulation of immune circumstances.