中文摘要：

目的分析表没食子儿茶素没食子酸酯（epigallocatechin gallate,EGCG）、Ni2＋及其相互作用对人牙龈成纤维细胞（human gingival fibroblast cells,HGF）的生物学效应。方法用MTT法检测HGF的存活率,运用彗星电泳检测细胞的DNA损伤情况,使用流式细胞仪法检测HGF周期变化。结果 Ni2＋可呈时间依赖性抑制HGF的生长,造成细胞DNA损伤,并且可使细胞周期阻滞于S期,诱导细胞凋亡。高浓度的EGCG（〉200μmol/L）可明显抑制HGF生长,使细胞的DNA损伤。Ni2＋与EGCG相互作用后增加了对HGF的抑制（P〈0.01）,DNA的损伤及凋亡细胞也明显增加（P〈0.05）。结论 Ni2＋和EGCG相互作用后使Ni2＋对HGF的抑制作用增强,加剧HGF的DNA损伤和细胞周期阻滞,并明显增加细胞凋亡。

英文摘要：

Objective To determine the biological effects of epigallocatechin gallate（EGCG）,Ni2＋ and their interactions on human gingival fibroblast（HGF） cells. Methods The viability of cells was determined by the MTT reduction assay.To measure DNA damage,we followed a modified version of comet assay.Cell cycle was analyzed by flow cytometry. Results Ni2＋ significantly inhibited the growth of HGF cells.Concentrations of Ni2＋ greater than 100 μmol/L significantly increased DNA strand breaks damage and arrested the cell cycle.The high concentrations of EGCG（greater than 200 μmol/L） could inhibit the growth of HGF cells.Greater than 150 μmol/L EGCG could increase the DNA strand break damage.The co-treatment of Ni2＋ and EGCG could increase Ni2＋-induced inhibit effect on HGF cells（P0.01）,and the DNA damage was significantly increased（P0.01）.Conclusions Ni2＋ mixed with EGCG could increase the Ni2＋-induced damage on the HGF cells and the blockage of cell cycle.