Evaluation of the antimutagenic and antiradical potentials of extracts from the tubers of (Tunisian) Cyperus rotundus

The mutagenic potential of aqueous, total oligomers flavonoids (TOF), ethyl acetate and methanol extracts from tubers of Cyperus rotundus L. was assessed using Ames Salmonella tester strains TA98 and TA100, and SOS chromotest strain Escherichia coli PQ37 with and without metabolic activation (S9). None of the different extracts produced a mutagenic effect. Likewise, the antimutagenicity of the same extracts was tested using the “Ames test” and the “SOS chromotest”. Our results showed that C. rotundus extracts possess antimutagenic effects against S. typhimurium TA98 and TA100 strains towards the mutagen aflatoxin B1 (AFB1), similar to E. coli PQ37 strain against AFB1 and Nifuroxazide mutagens using the SOS chromotest assay. A free radical scavenging test was used in order to explore the antioxidant capacity of the extracts obtained from the tubers of C. rotundus. TOF, ethyl acetate and methanol extracts showed an important free radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazine (DPPH) free radical. These extracts showed an IC50 value of respectively 5, 20 and 65?µg?mL^?1. The beneficial effects of TOF, ethyl acetate and methanol extracts of C. rotundus were assessed by antioxidant and antimutagenic activities.     

壬基酚聚氧乙烯醚降解前后的激素效应和诱变活性

采用重组基因酵母和SOS/Umu试验研究了壬基酚聚氧乙烯醚(NP₁₀EO)经生物降解前后的雌激素活性和致突变活性.结果表明,在降解反应开始后的4d内降解产物的雌激素活性较低且不具有致突变性.随着降解时间的不断增加,降解产物的雌激素活性和致突变性不断增强.降解20d后,降解产物的雌激素活性相当于1nmol 17-β雌二醇的61.6%,诱变比值大于2,表明壬基酚聚氧乙烯醚的生物降解产物同时具有雌激素活性和致突变活性,且两者在产生时间和活性数值方面均是同步的和成正相关的.因此致突变活性很可能是此类降解产物对生物机体具有雌激素活性的基础.     

用SOS/umu试验评价降雨径流遗传毒性的变化

通过SOS/umu试验分析检测屋面和道路在2017年5、6月2场降雨过程中的遗传毒性变化。结果表明,从降雨初期到结束,在5月份屋面产生降雨径流2 h内和道路产生径流20 min内雨水样品的检测结果均呈阳性,诱导率IR均大于2,表现出DNA损伤效应;在6月份屋面产生降雨径流60 min内和道路产生径流10~60 min内雨水样品的结果均呈阳性,表现出遗传毒性。2场降雨中屋面和道路雨水样品的TEQ4-NQO均随降雨时间先增加后逐渐减小,5月份屋面雨水样品的毒性大于路面雨水样品的毒性,6月份则相反。遗传毒性分析降雨径流中污染物毒性的变化为雨水的安全利用提供理论基础。     

南京市主要饮用水源水中有机污染物的遗传毒性研究

运用鼠伤寒沙门氏菌 /哺乳动物微粒体酶系 ( Ames)试验 ( DNA)、SOS/Umu试验 (基因 )和蚕豆根尖微核试验(染色体 )对不同季节 (枯、丰、平 )南京市主要水厂的水源水中有机污染物的遗传毒性进行了研究。以 XAD-2树脂为吸附剂 ,丙酮 -甲醇的混合液为洗脱液 ,浓缩水样中有机物 ,并对部分阳性水样进行了有机组分的定性分析 ( GC/MS法 )及其污染源调查。结果发现 ,不同季节水样均有不同程度的遗传毒性检出 ,其中以上元门水厂水质最劣 ;同时通过 GC/MS法分析 ,发现阳性水样中存在有美国 EPA所列的多种优先污染物以及其它黑名单上所属的有毒有害物质 ,应当引起足够的重视     

Effect of electronic waste on E. coli genomic integrity: a possible role for metal induced carcinogenesis

Electronic waste (e-waste) poses a major public health threat for developing countries’ populations. The hazards of e-waste are exacerbated by crude recycling methods. In this study, the presence of metals in e-waste samples obtained from Lagos, Nigeria, was assessed using atomic absorption spectrometry. The effect of e-waste on Escherichia coli (E. coli) PQ-37 genomic integrity was evaluated using the SOS chromotest. The means of metal concentrations in the evaluated samples were 16 (cadmium), 7.3 (nickel), 11 (chromium), 20 (lead), 3100 (iron), 90 (zinc), and 2000 (copper) μg_L^?1. Damage to E. coli deoxyribonucleic acid (DNA) increased proportionally to the metal concentrations. Significant amounts of DNA damaging agents from inadequately processed e-waste are present in the studied environment, which will have implications for adverse effects on public and ecological health. Existing policies against dumping of toxic materials in susceptible communities should be enforced.     

利用SOS/umu测试评价某电子垃圾处理地土壤的遗传毒性

由电子垃圾不当处理引起的环境污染问题已经引起普遍关注.采用SOS/umu测试方法对我国南方某电子垃圾处理地23个土壤样品的有机提取物的直接和间接遗传毒性进行了初步的评估和筛选.结果表明,在有机提取物最高暴露浓度相当于100mg·well-1时,只有很少一部分样品检出直接遗传毒性,而绝大多数样品的有机提取物经过代谢活化后,表现出遗传毒性.与对照地区土壤相比,从事电子垃圾回收处理的地区土壤中存在间接致突变物质的积累,这可能与当地粗放形式的电子垃圾处理活动有关.     

天津地区土壤中遗传毒性物质的分布规律

利用SOS／umu试验测试了天津地区41个土壤样品有机提取物的遗传毒性,研究了该地区土壤中遗传毒性物质污染水平及区域生态风险的分布规律．结果表明,在所研究区域中,遗传毒性的高风险区主要分布在天津市和塘沽、汉沽两个区．其中,汉沽区土壤有机组分遗传毒性值最高,其次为塘沽区和市区．与有限的文献报道数据相比,天津地区土壤有机组分的遗传毒性较高,且与该地区土壤中多环芳烃浓度的分布规律相似．研究结果表明,遗传毒性的生物效应标记方法可以用于区域生态风险评价,来快速筛选和甄别遗传毒性物质污染的高风险区．