中文摘要：

目的探讨甘草酸二铵（DG）对人肝癌细胞SMMC-7721增殖的抑制作用及对p53表达的影响。方法实验分对照组及DG干预组,采用MTT比色法测定细胞的生长情况,检测DG对细胞增殖的抑制作用;RT-PCR检测DG对p53mRNA表达水平的影响;通过Western blot测定DG对p53蛋白表达的影响。结果 DG（0.50、1.00、2.00、4.00、8.00、16.00mg/L）呈浓度依赖性降低人肝癌细胞存活率,作用48h时IC50值为（4.31±0.21）mg/L;DG可明显抑制肝癌细胞增殖,剂量为4.00、8.00、16.00mg/L时,其抑制率分别为44.52%、66.78%、91.24%;低、中、高浓度组DG（2.0、4.0、8.0mg/L）可明显提高肝癌细胞中p53mRNA及其蛋白表达,并呈浓度依赖性增强。结论 DG对人肝癌细胞SMMC-7721具有明显细胞毒性和抑制增殖作用,其机制可能与上调p53表达有关。

英文摘要：

Objective To investigate the inhibiting effect of diammonium glycyrrhizinate（DG） on proliferation of liver cancer cell SMMC-7721 in vitro and its effect on p53 expression. Methods Two groups were set up：the study group（DG intervention） and the control group without DG. MTT assay was used to measure the cell growth and the inhibiting effect of DG on SMMC-7721 cells. P53 mRNA was quantified by real-time fluorescence quantitative PCR,followed by Western blot for detecting p53 protein expres sion. Results The survival rate of SMMC 7721 cell was decreased by DG（0.50,1.00,2.00,4.00,8.00,16.00 mg/L） in a concen- tration dependent manner,and the ICs0 value for 48 h was（4. 31 _4_ 0. 21） mg/L. The inhibition rate was respectively 44.52%, 66.78 % and 91.24 % in 4.00,8.00,16.00 mg/L treatment groups. The gene and protein expressions of p53 were obviously up-regulated after exposure to DG in 2.00,4.00,8.00 mg/L treatment groups. Conclusion DG inhibits the growth of liver cancer cell SMMC-7721 obviously. And its mechanism may be related to up regulate p53 expression.