微囊藻毒素与饮用水有机提取物联合致HepG_2细胞DNA损伤的研究

目的探讨微囊藻毒素(MC-LR)与管网末梢水有机提取物联合致HepG2细胞DNA损伤的作用。方法于2007年7月采集某市的管网末梢水,分别选用XAD-2、XAD-8大孔吸附树脂以及两者等体积配制的复合树脂(简称XAD-2/8)富集为100、10和30ml/ml的有机物。应用彗星试验,研究MC-LR与管网末梢水有机提取物联合致HepG2细胞(1×105个/孔)DNA损伤的作用。结果与溶剂对照组相比,0.5μg/mlMC-LR染毒组可使HepG2细胞Olive尾矩值显著增加(P0.01)。较高浓度(0.1、0.5μg/ml)MC-LR与经XAD-2树脂富集的有机物(100ml/ml)联合染毒时,所诱导的HepG2细胞Olive尾矩值较之相应的单独作用组显著增加(P0.01);0.05、0.1、0.5μg/mlMC-LR与经XAD-8树脂富集的有机物(10ml/ml)联合染毒时,所诱导的HepG2细胞Olive尾矩值较之相应的单独作用组显著增加(P0.01);较高浓度(0.1、0.5μg/ml)MC-LR与经XAD-2/8树脂富集的有机物(30ml/ml)联合染毒时,所诱导的HepG2细胞Olive尾矩值较之相应的单独作用组显著增加(P0.01)。运用析因分析统计学方法,发现MC-LR与3种树脂富集的饮用水有机提取物存在交互作用(P0.01)。结论饮用水有机提取物与MC-LR之间存在协同作用,MC-LR可以极大地增强饮用水中有机物的致DNA损伤作用。

Combined Effect of Microcystins and Organic Extracts of Drinking Water on DNA Damage in HepG_2 Cells

Objective To know the combined effect of microcystins and organic extracts from tap water on DNA damage. Methods Three kinds of macroporous adsorptive resins (XAD-2, XAD-8, XAD-2 and XAD-8 equal proportion mixed resin-XAD-2/8) were used to concentrate the organic compounds from tap water in Wuhan city in September 2007. The concentrations of organic compounds extracted by XAD-2, XAD-8 and XAD2/8 were 100, 10, 30 ml/ml respectively. The combined effect of MC-LR and organic extracts from tap water on DNA damage in HepG_2cells (1×10~5/hole) was determined by using comet assay. Results The high concentration of MC-LR (0.5 μg/ml) induced significant increase of OTM compared with the negative control (P＜0.01).When HepG_2 cells were co-exposed to MC-LR (0.1 μg/ml,0.5 μg/ml) and organic compounds concentrated by XAD-2 (100 ml/ml),OTM were significantly increased compared with the corresponding alone exposure'(P＜0.01). When HepG_2 cells were co-exposed to MC-LR (0.05 μg/ml,0.1 μg/ml,0.5 μg/ml) and organic compounds concetitrated by XAD-8 (10 ml/ml),OTM were significantly increased compared with the corresponding alone exposure'(P＜0.01). When HepG_2 cells were co-exposed to MC-LR (0.1 μg/ml, 0.5μg/ml) and organic compounds concentrated by XAD-2/8 (30 ml/ml),OTM were significantly increased compared with the corresponding alone exposure (P＜0.01). Factorial analysis revealed that co-exposure to organic compounds concentrated by the three resins and MC-LR had interaction effects (P＜0.01). Conclusion There is a synergistic effect between organic extracts from tap water and MC-LR. MC-LR may reinforce the effect of DNA damage induced by organic extracts from drinking water.