绿茶浸出液对水中有机污染物致DNA损伤的抑制作用

Study on the Inhibiting Effects of Green Tea Leachate on DNA Damage Induced by Organic Pollutants in Water

目的探讨绿茶浸出液能否抑制水中有机污染物对细胞DNA的损伤。方法 固相萃取水中有机物,用绿茶浸出液与有机提取物以不同方式处理(同时处理、绿茶预处理、绿茶后处理)大鼠肝细胞后,采用单细胞凝胶电泳实验检测细胞,观察DNA迁移长度及拖尾细胞百分率,并检测培养液中丙二醛含量。结果同时处理组和绿茶预处理组的结果显示绿茶浸出液浓度在0.5、5、50μg/ml时可缩短DNA迁移长度,与水样对照组比较,差异有非常显著意义(P<0.01),拖尾细胞百分率和培养液中丙二醛含量的变化与此一致;后处理组细胞损伤明显加重,分水样对照组比较,差异有显蓍性(P<0.01)。结论绿茶浸出液对水中有机提取物致肝细胞DNA的损伤有保护作用,且在一定的浓度范围内呈剂量一反应关系。机制可能是抑制水中有机提取物对细胞的氧化损伤。

Objective To study the inhibiting effects of green tea leachate on DNA damage induced by organic extracts from water. Methods Solid phase extraction was used to extract the organic pollutants in tap water and the primary cultured rat heptocytes were treated with green tea leachate and organic extracts of water in several different ways (simultaneous treatment with green tea leachate and organic extracts of water, pre-treatment and post-treatment with green tea leachate respectively). Then single cell gel electrophoresis test was used to detect the inhibition of DNA damage. Comet length means and percentage of tailed-cell were observed, and the levels of MDA in the culture medium were determined. Results The DNA migration length induced by water organic extracts was reduced by green tea leachate at the concentrations of 0.5, 5 and 50 μg/ml (P<0.01) in simultaneous and pre-treatment groups, and it showed a dose-response relationship. The percentage of tailed-cell and the concentration of MDA in the cell culture medium were decreased significantly. The cells post-treated by grean tea leachate were damaged significantly and seriously than those of control group (P<0.01). Conclusion Green tea leachate could inhibit the DNA damage of rat primary heptocytes induced by water organic extracts, and the dose-effect relationship was noticed. The mechanism of the protection effects on DNA damage might be due to the anti-oxidation action of green tea leachate.