白花蛇舌草多糖诱导人胃癌细胞凋亡作用的研究

目的研究白花蛇舌草多糖对体外培养人胃癌7901细胞增殖抑制的影响及其作用机理。方法采用MTT法测定不同浓度白花蛇舌草多糖对人胃癌7901细胞增殖的影响;流式细胞技术检测药物作用后的细胞周期和凋亡率;RT-PCR方法检测药物对人胃癌7901细胞P53和Bcl-2基因表达的影响。结果白花蛇舌草多糖能明显抑制人胃癌7901细胞的增殖,其作用48 h的IC50约为116.52 mg·L-1;流式细胞检测显示40 mg·L-1白花蛇舌草多糖联合5.0 mg·L-1顺铂组总凋亡率为69.42%,明显优于顺铂组的50.85%（P〈0.01）和40 mg·L-1白花蛇舌草多糖组的26.41%（P〈0.01）;PCR结果显示高、中浓度白花蛇舌草多糖可使人胃癌7901细胞的bcl-2 mRNA表达量降低,P53 mRNA表达量增加。结论白花蛇舌草多糖能明显诱导人胃癌7901细胞的凋亡,与顺铂联合可产生协同作用,其作用机制可能与降低细胞bcl-2和增加P53基因表达量有关。

Effect on Apoptosis of Human Gastric Cancer Cells Induced by Hedyotis Diffusae Polysaccharide

Objective To investigate the inhibitory effect of Hedyotis Diffusae polysaccharide on proliferation of human gastric cancer SGC-7901 cells in vitro and the mechanism of action.Methods Proliferation of SGC-7901 cells affected by different concentrations of Hedyotis Diffusae polysaccharide was tested by MTT assay.Cell cycles and apoptosis rates were tested by flow cytometry and the effect on mRNA expression of P53 and Bcl-2 was determined by RT-PCR.Results Proliferation of SGC-7901 cells was significantly inhibited by Hedyotis Diffusae polysaccharide.IC50 within 48 h was about 116.52 mg·L-1.The flow cytometry showed that the total apoptosis rate（69.42%） of Hedyotis Diffusae polysaccharide（40 mg·L-1） combined with cis-platinum（5.0 mg·L-1） was higher than in cis-platinum alone（5.0 mg·L-1,the apoptosis was 50.85%,P 〈 0.01） or in Hedyotis Diffusae polysaccharide alone（40 mg·L-1,the apoptosis rate was26.41%,P 〈 0.01）.The mRNA expression of Bcl-2 gene was reduced while that of P53 gene was increased by high and medium concertrations of Hedyotis Diffusae polysaccharide.Conclusion Hedyotis Diffusae polysaccharide significantly inhibits the proliferation of SGC-7901 cells and produces synergy when used with cis-platinum.The mechanism may be related to reduced expression of Bcl-2 and increased expression P53 gene.