Mutagenic, genotoxic and enzyme inhibitory effects of carbosulfan in rainbow trout Oncorhynchus mykiss

Rainbow trout (Oncorhynchus mykiss; 116.88 ± 21.69 g) were exposed to sublethal concentrations (25 μg/L) of carbosulfan for 60 days to test if the long term exposure of fish to carbosulfan affects red blood cells acetylcholinesterase (AChE), δ-aminolevulinic acid dehydratase (ALA-D) and paraoxonase (PON) enzyme activity and induces genotoxic and/or mutagenic effects. The exposure resulted in inhibition of AChE and ALA-D activity of rainbow trout when compared to control fish. The activity of PON was not affected by carbosulfan. Interestingly, carbosulfan was found to induce DNA damage in red blood cells (comet assay) and proved to be mutagenic as revealed by the Ames test. Results indicate that blood AChE and ALA-D of rainbow trout may be a sensitive biomarker for assessment of carbosulfan contaminated water bodies. Furthermore, because the Ames test and comet assay were proven successful to detect the genotoxicity of carbosulfan, we proposed that nonlethal techniques such as blood collection from caudal vein of fish should be used to determine potential toxic effects of other pesticides to surrounding environment.     

新疆药用层孔菌补益作用的研究

本研究采用抗应激实验的方法，观察新疆药用层孔菌对小鼠抗疲劳能力以及耐常压缺氧能力的影响,比较给药组与对照组小鼠存活的时间，对测试结果的方差分析及多重比较表明，药用层孔菌具有很好的补益作用，能增加小鼠的抗应激能力,同样条件下能延长小鼠的存活时间。     

亚硒酸钠突变试验研究

为评价亚硒酸钠的致突变性,进行了Ames试验,结果表明：在5～0.008 mg亚硒酸钠/皿剂量范围内,在加S9混合物和不加S9混合物时,受试物对鼠伤寒沙门氏菌TA97、TA98、TA1535、TA100、TA102五株试验菌株,在加与不加S-9时试验结果均为阴性.     

Evaluation of the Antioxidant Activity of Cell Extracts from Microalgae

A growing market for novel antioxidants obtained from non-expensive sources justifies educated screening of microalgae for their potential antioxidant features. Characterization of the antioxidant profile of 18 species of cyanobacteria (prokaryotic microalgae) and 23 species of (eukaryotic) microalgae is accordingly reported in this paper. The total antioxidant capacity, accounted for by both water- and lipid-soluble antioxidants, was evaluated by the (radical cation) ABTS method. For complementary characterization of cell extracts, a deoxyribose assay was carried out, as well as a bacteriophage P22/Salmonella-mediated approach. The microalga Scenedesmus obliquus strain M2-1 exhibited the highest (p > 0.05) total antioxidant capacity (149 ± 47 AAU) of intracellular extracts. Its scavenger activity correlated well with its protective effects against DNA oxidative damage induced by copper(II)-ascorbic acid; and against decay in bacteriophage infection capacity induced by H₂O₂. Finally, performance of an Ames test revealed no mutagenic effects of the said extract.     

之江菌素对沙门氏菌和小鼠的致突变研究

通过Ames试验、精子畸变试验和微核试验检测之江菌素诱变性.结果表明,用低浓度(0.05 μg/皿)至高浓度(500 μg/皿)6个梯度的之江菌素样品处理后,鼠伤寒沙门氏菌组氨酸营养缺陷型TA97a,TA98,TA100,TA102的回复突变菌落数均未超过其自发回复突变菌落数的两倍;用461.52,230.76,115.38 mg/kg 3个剂量处理ICR雄性小鼠,低、中剂量组精子畸形数与阴性对照组无显著性差异(P>0.05),高剂量组呈显著差异(P<0.05),但无剂量反应关系;576.9,115.38,57.69 mg/kg 3个剂量未能诱发ICR雄性小鼠的微核增加,对细胞分裂亦无明显影响,表明各项试验结果均为阴性.因此在本试验条件下,之江菌素是一种非诱变剂.     

(Q)SAR tools for the prediction of mutagenic properties: Are they ready for application in pesticide regulation?

The assessment of human health risks resulting from the presence of metabolites in groundwater and food residues has become an important element in pesticide authorisation. In this context, the evaluation of mutagenicity is of particular interest and a paradigm shift from exposure‐triggered testing to in silico‐based screening has been recommended in the European Food Safety Authority (EFSA) Guidance on the establishment of the residue definition for dietary risk assessment. In addition, it is proposed to apply in silico predictions when experimental mutagenicity testing is not possible due to a lack of sufficient quantities of the pesticide metabolite. This, combined with animal welfare and economic considerations, has led to a situation where an increasing number of in silico studies are submitted to regulatory authorities. Whilst there is extensive experience with in silico predictions for mutagenicity in the chemical and pharmaceutical industry, their suitability in pesticide regulation is still insufficiently considered. Therefore, we herein discuss critical issues that need to be resolved to successfully implement (Quantitative) Structure‐Activity Relationship ((Q)SAR) as an accepted tool in pesticide regulation. For illustration purposes, the results of a pilot study are included. The presented study highlights a need for further improvement regarding the predictivity and applicability domain of (Q)SAR systems for pesticides and their metabolites, but also raises other questions such as model selection, establishment of acceptance criteria, harmonised approaches to the combination of model outputs into overall conclusions, adequate reporting and data sharing. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

不同产地绶草中总黄酮的含量测定

采用分光光度法,检测波长为510 nm,以芦丁为对照品,测定绶草(Spiranthes sinensis (Pers)Ames)中总黄酮的含量.总黄酮含量在0.004 03～0.020 16 mg/mL范围内呈良好的线性关系(r=-0.997),平均回收率(n=6)为97.68％,RSD为1.93％.该方法操作简便、快速、准确,可用于绶草中总黄酮含量测定.     

乳铁蛋白牛初乳颗粒的毒理安全性研究

[目的]为判定聪贝优牌乳铁蛋白牛初乳颗粒对人体健康是否产生危害,进行了聪贝优牌乳铁蛋白牛初乳颗粒的安全性毒理学评价。[方法]采用急性毒性试验、Ames试验、小鼠骨髓微核实验、微小鼠精子畸形试验和30 d喂养试验对聪贝优牌乳铁蛋白牛初乳颗粒急性毒性、致突变性以及亚慢性毒性进行了研究。[结果]聪贝优牌乳铁蛋白牛初乳颗粒小鼠急性毒性试验LD50大于20.0 g/(kg.bw),属实际无毒;对基因、体细胞与生殖细胞无明显致突作用;受试物分别按1.00、2.00、4.00 g/(kg.bw)的剂量喂养大鼠30 d,结果表明动物未出现异常。[结论]根据试验结果,可判定聪贝优牌乳铁蛋白牛初乳颗粒为安全性食品。     

转Bt基因水稻稻米的诱变活性研究

利用微核、精子畸变和Ames试验检测了转Bt基因水稻稻米对小鼠骨髓嗜多染红细胞(polychromatic erythrocytes,PCE)微核率(micronucleus frequency,MN%)和小鼠精子畸形发生率(sperm malformation rate)及组氨酸营养缺陷型鼠伤寒沙门氏菌株回变菌落数的影响。结果表明,在本实验条件下,Bt水稻稻米对小鼠体细胞和性细胞均无诱变活性,且无剂量效应;该受试物对TA97a、TA98、TA100和TA102菌株无论在有无代谢活化系统存在的条件下,各剂量组回变菌落数均处于正常水平。     

对虾保鲜剂急性毒性和致突变作用研究

采用霍恩氏法进行对虾保鲜剂对小白鼠的急性毒性试验研究,结果表明:对虾保鲜剂对雌雄小鼠半数致死量(LD50值)>10g/kg体重,毒性分级属实际无毒级。在加与不加代谢活化系统(S-9)的条件下,利用4个组氨酸营养缺陷型鼠伤寒沙门氏菌菌株(TA97、TA98、TA100、TA102),采用平板渗入进行鼠伤寒沙门氏菌哺乳动物微粒体酶试验(Salmonella typhimurium mammals microsomal enzyme test,Ames),研究对虾保鲜剂的致突变作用,结果表明:对虾保鲜剂对4个菌株诱发的回变菌落数与阴性对照组的回变菌落数之间没有显著差异(P>0.05),均未超过阴性对照组2倍,Ames试验结果为阴性,表明对虾保鲜剂对鼠伤寒沙门氏菌无直接和间接致突变作用。