Costa C, Silvari V, Melchini A, Catania S, Heffron J J, Trovato A, De Pasquale R
Dip. Medicina Sociale del Territorio, Sez. Medicina del Lavoro, Policlinico Universitario Gaetano Martino, 98125 Messina, Italy.
Mutat Res. 2009 Jan;672(1):40-4. doi: 10.1016/j.mrgentox.2008.09.018. Epub 2008 Oct 11.
Imidacloprid is a neonicotinoid insecticide combining excellent efficiency against parasites with low toxicity for mammals. Commercially, it is co-formulated with dimethyl sulfoxide, methylpyrrolidone, propylene carbonate and mineral oil, which can modify its bioavailability and toxicological profile for humans following occupational exposure. A combined in vitro approach employing the comet assay and the micronucleus test was used to assess the genotoxicity of imidacloprid in relation to formulation, metabolic activation and exposure level. Human peripheral blood lymphocytes from unexposed healthy volunteers were treated with imidacloprid (0.2, 2 and 20 μM) and with equimolar concentrations of a commercial product, with and without addition of S9 fraction. Imidacloprid significantly increased the comet score and the frequency of micronuclei only at the highest concentration tested. DNA damage was slightly more severe with the commercial product, and was increased, though not significantly, by metabolic activation. Formation of reactive oxygen species (ROS) does not seem to be involved as a mechanism of genotoxicity, but this result may be explained by the insufficient sensitivity of the 2',7'-dichlorofluorescein diacetate assay at the test concentrations of imidacloprid. These results suggest that at concentrations<20 μM imidacloprid is not genotoxic to human lymphocytes in vitro. Nonetheless, the presence of co-formulants in the commercial product and occupational exposure, along with poor safety procedures, may present an increased risk for DNA fragmentation and chromosomal aberrations.
吡虫啉是一种新烟碱类杀虫剂，对寄生虫具有高效杀灭作用，对哺乳动物毒性较低。在商业上，它与二甲基亚砜、甲基吡咯烷酮、碳酸丙烯酯和矿物油混合配制，这些物质会改变其职业接触后对人类的生物利用度和毒理学特征。采用彗星试验和微核试验相结合的体外方法，评估吡虫啉在制剂、代谢活化和接触水平方面的遗传毒性。用吡虫啉（0.2、2和20 μM）以及等摩尔浓度的一种商业产品处理未接触过的健康志愿者的人外周血淋巴细胞，添加或不添加S9组分。仅在最高测试浓度下，吡虫啉显著增加了彗星试验评分和微核频率。商业产品导致的DNA损伤略严重一些，代谢活化使其有所增加，但不显著。活性氧（ROS）的形成似乎不是遗传毒性的机制，但这一结果可能是由于在吡虫啉测试浓度下，二氯荧光素二乙酸酯检测的灵敏度不足所致。这些结果表明，在浓度＜20 μM时，吡虫啉在体外对人淋巴细胞无遗传毒性。尽管如此，商业产品中混合剂的存在以及职业接触，再加上安全程序不完善，可能会增加DNA片段化和染色体畸变的风险。
