Genotoxic and cytotoxic in vitro evaluation of ivermectin and its formulation ivomec® on Aedes albopictus larvae (CCL-126™) cells

Genotoxic effects of ivermectin (IVM) and its commercial formulation ivomec® (IVM 1.0%) were studied on Aedes albopictus larvae (CCL-126?) cells by sister chromatid exchange (SCE) and single cell gel electrophoresis (SCGE) while cytotoxicity was determined by cell-cycle progression (CCP), proliferative rate index (PRI), mitotic index (MI), 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and neutral red (NR) endpoints within a 1–250 µg mL^?1 concentration range. While IVM and ivomec® did not markedly affect SCE frequencies, these agents induced DNA-strand breaks enhancing both slightly damaged and damaged cells at 25–50 and 5–50 µg mL^?1 IVM and ivomec®, respectively. Both compounds exerted a delay in CCP and reduction of PRI at 10 µg mL^?1. Cytotoxicity was observed at concentrations higher than 25 µg mL^?1. A marked reduction of about 98% and 94% of MI compared to controls was noted with 25 µg mL^?1 of IVM and ivomec®, respectively. NR and MTT assays revealed that both compounds induced a cell growth inhibition within the 1–250 µg mL^?1 concentration range. Data indicated that IVM and ivomec® exert both genotoxicity and cytotoxicity in insect cells in vitro, at least in A. albopictus larvae CCL-126? cells.     

Studies on the water extracts of medicinal plants grown in copper mining areas and their antioxidant effects

High copper (Cu) accumulation in medicinal plants might favor lipid peroxidation and hence affect antioxidant responses. This effect was studied by determining antioxidant activities in the water extracts of medicinal plants from Cu mining impact site and compared with control samples. Antioxidant activities of the extracted medicinal plants were assayed by measuring (1) total phenolic and flavonoid contents, (2) diphenyl-1-picrylhydrazyl (DPPH)^? free radical scavenging activity, and (3) inhibition capacities of lipid peroxidation. The total phenolic as well as total flavonoid contents of the mining impact samples and control samples are not significantly different. However, inhibition of lipid peroxidation capacities was significantly less (12–60%) for mining impact samples as reflected by the IC₅₀ values. These anomalies were attributed to high concentrations of Cu (2–4-fold higher) in mining impact samples as measured by inductively coupled plasma mass spectrometry. A positive correlation was observed between Cu levels and IC₅₀ values for the inhibition of lipid peroxidation for mining impact samples.     

Cytotoxicity of single-walled carbon nanotubes,multi-walled carbon nanotubes,and chrysotile to human lung epithelial cells

Carbon nanotubes (CNTs) have found numerous applications in various industries. Recently, adverse effects of these materials on human and animal cells in vitro have been reported. In the present study, the cytotoxicity of single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), and chrysotile asbestos in human lung epithelial cells has been studied using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cells were exposed for 6 h and 24 h to between 0.97 and 1500 μg mL^?1 of CNTs and chrysotile fibers prepared in two culture media containing 5% serum and 0.5% dimethylsulfoxide. Dose–response curves were obtained to determine the nonobservable adverse effect concentration and the half-maximum inhibitory concentration (IC₅₀). The way of dispersion affects the cytotoxicity of CNTs. For MWCNT, the toxicological indexes were lower than for SWCNT. Chrysotile fibers were even less cytotoxic than CNTs. Therefore, workplace control measures are recommended as priority for occupational and environmental conditions.     

DNA damage in mouse organs and in human sperm cells by bisphenol A

Abstract

The in vivo genotoxic potential of bisphenol A using the comet assay in mice and in human sperm cells in vitro without metabolizing enzymes was studied. Male mice were exposed by oral gavage to the following doses of bisphenol A (0 125, 250 and 500?mg/kg body weight). DNA damage was investigated in liver, kidney, testes, urinary bladder, colon and lungs cells. In testicular cells, a significant increase in DNA strand breaks was observed in the lowest, but not in the medium or highest dose groups. Histopathological investigation of the testicular samples did not show any treatment dose-related effects. No DNA strand breaks were observed in any of the other investigated tissues. In human sperm cells in vitro, bisphenol A did not induce DNA strand breaks.     

石油烃对栉孔扇贝血淋巴细胞DNA损伤的初步研究

为研究石油烃对海洋生物的毒性效应,将栉孔扇贝(Chlamys farreri)暴露于0.08、0.21和0.88mg·L-1石油烃中,采用单细胞凝胶电泳实验(彗星实验)技术检测不同暴露时间扇贝血淋巴细胞的DNA损伤程度,对照组中石油烃背景浓度为0.04mg·L-1。结果显示,低浓度(0.08mg·L-1)的石油烃短期(<7d)内即可导致栉孔扇贝血淋巴细胞的DNA损伤,并且随石油烃浓度的增大和暴露时间的延长,DNA损伤程度增加,石油烃浓度达0.88mg·L-1时,DNA损伤程度已非常严重。3d恢复实验后,各浓度组DNA损伤又均有不同程度的恢复。研究表明,彗星实验是检测石油烃对海洋贝类DNA损伤的一种有效手段,贝类血淋巴细胞DNA损伤有望成为石油烃污染的一种生物标志物,用于海洋污染的早期预警监测。     

生物可降解材料PHBV的细胞毒性评价的研究

通过体外细胞毒性试验,对新型材料β-羟基丁酸与β-羟基戊酸共聚物(PHBV)的细胞生物相容性进行了研究.主要依据ISO10993及GB/T16886-1997的标准,应用四甲基偶氮唑盐(MTT assay)比色法对PHBV的细胞毒性进行评价.选用不同体积分数、不同温度下的PHBV材料浸提液为培养液,以及与PHBV材料直接接触培养来检测1d、3 d、5 d小鼠成纤维细胞BHK-21的相对增值率,确定PHBV材料的毒性程度.实验结果表明,PHBV材料即使在高温下其物理化学性质也很稳定;它的细胞毒性程度为0级,有着良好的细胞生物相容性.     

Screening of textile finishing agents available on the Chinese market: An important source of per- and polyfluoroalkyl substances to the environment

Kendrick mass defect was used for PFASs screening in textile finishing agents (TFAs). Total oxidizable precursor assay provides insight into unknown precursors. Perfluorooctane sulfonate was found as impurity in short ECF technology based TFAs. Perfluorooctanoate was also detected in C6 telomerization based TFAs. Long chain precursors were also observed in both types of TFAs. Organofluorinated surfactants are widely employed in textile finishing agents (TFAs) to achieve oil, water, and stain repellency. This has been regarded as an important emission source of per-and polyfluoroalkyl substances (PFASs) to the environment. China is the biggest manufacturer of clothes, and thus TFA production is also a relevant industrial activity. Nevertheless, to date, no survey has been conducted on PFAS contents in commercially available TFAs. In the present study, TFA products were investigated by the Kendrick mass defect method. The quantification results demonstrated a significant presence of perfluorooctane sulfonate (0.37 mg/L) in TFAs manufactured by electrochemical fluorination technology. The products obtained by short-chain PFAS-based telomerization were dominated by perfluorooctanoic acid (mean concentration: 0.29 mg/L), whose values exceeded the limits stated in the European Chemical Agency guidelines (0.025 mg/L). Moreover, the total oxidizable precursor assay indicated high levels of indirectly quantified precursors with long alkyl chains (C7–C9). Together, these results suggest that there is currently a certain of environmental and health risks in China that originates from the utilization of TFAs, and a better manufacturing processes are required to reduce such risks.     

用CBMN法评价饮用水处理流程中有机提取物的细胞毒性

利用ＣＨＯ细胞胞质分裂阻断微核（ＣＢＭＮ）法,对某自来水厂７个处理工艺流程水中的有机提取物的细胞毒性进行了评价。在实验剂量范围内,比较了各样品的含微核的双核细胞率（ＢＮＭＮ）、核分裂指数（ＮＤＩ）和胞质分裂阻断增殖指数（ＣＢＰＩ）,实验表明,源水加氯后比源水的细胞性增大,经机加池和煤砂滤池处理后的水样毒性较大,其中煤砂滤池水毒性最大,机加池水次之,经炭吸附后的水样比炭吸附前水样的毒性下降,管网水的     

用SOS/umu测试评价光电催化降解五氯酚过程的遗传毒性特征

采用SOS/umu测试研究了五氯酚水溶液在光电催化反应过程中的遗传毒性变化及降解产物对鼠伤寒沙门氏菌TA1535/pSK1002的细胞毒性,并与五氯酚在直接光解、光催化反应过程中的降解产物进行了比较.五氯酚光电催化降解过程中降解产物对测试菌种的细胞毒性逐渐降低,产物经代谢活化的细胞毒性低于直接光解、光催化降解五氯酚的产物.五氯酚经光电催化降解15￣45分钟的产物经代谢活化测试结果呈阳性,在60￣120分钟的降解产物呈阴性,说明五氯酚的光电催化降解过程中生成了间接遗传毒性物质,但该类物质能够在光电催化过程中被去除.而五氯酚经直接光解、光催化处理120分钟的产物均具有遗传毒性风险.本研究结果表明光电催化技术的环境安全性优于直接光解、光催化技术.此外,SOS/umu测试作为一种简单、灵敏的遗传毒性物质检测方法,适合于评价光电催化技术的遗传毒性特征,可以作为评价该技术环境安全性的生态毒理学方法之一.     

荧光染色法测定活性污泥中的活性生物量

活性污泥中活性微生物量是表征污染物去除能力的重要指标。探索了荧光染色法直接检测活性细菌的原理和测定方法,结果表明,大肠杆菌、唾液链球菌和铜绿假单胞杆菌的活菌细胞浓度与荧光光强的线性相关度都超过0.95;在惰性颗粒物浓度为20 mg/L到60 mg/L的范围内,其对荧光光强的影响可通过线性关系修正;搅拌速度为1 000 r/min且搅拌10 min时前处理效果最好。