Cell Cycle and Mismatch Repair Genes as Potential Biomarkers in Arabidopsis thaliana Seedlings Exposed to Silver Nanoparticles

The expression of cell cycle genes and DNA mismatch repair (MMR) genes were analyzed in Arabidopsis thaliana seedlings exposed to 0, 0.2, 0.5 and 1 mg/L of silver nanoparticles for 24, 48 and 72 h using real-time PCR. Significant up-regulation of AtPCNA1 was observed after 24 h exposure to 0.2 and 0.5 mg/L of silver nanoparticles. AtPCNA2 gene was up-regulated after 24, 48 and 72 h exposure to 0.5 and 1 mg/L of silver nanoparticles. AtMLH1 gene was up-regulated after 48 h exposure to 0.5 and 1 mg/L of silver nanoparticles and down-regulated after 72 h. Down-regulation of AtMSH2, AtMSH3, AtMSH6 and AtMSH7 mRNA was observed after exposure to all concentrations of silver nanoparticles for different time periods. Exposure to silver ions showed no significant change in the expression levels of AtPCNA and MMR genes. The results show that AtPCNA and MMR genes could be used as potential molecular biomarkers.     

纳米银抗菌材料在医疗器具与生活用品中的应用

介绍了纳米银抗菌材料的抗菌原理及特性,并叙述了其在医疗器具与生活用品中的新近应用情况。     

Rapid Surface-Enhanced Raman Spectroscopy Detection of Chlorothalonil in Standard Solution and Orange Peels with Pretreatment of Ultraviolet Irradiation

Bulletin of Environmental Contamination and Toxicology - At present, the detection of chlorothalonil is generally based on chromatography and immunoassay; both of which are time-consuming and...     

纳米银的抗菌原理及生物安全性研究进展

由于纳米银独特的抗菌特性,使其得到了广泛的应用,极大地增加了人们接触纳米银的机会,对其安全性进行评价就成为迫切需要解决的问题.迄今为止,国内外对纳米银的毒性研究在方法上主要集中于形态学、线粒体功能测定、细胞增殖、酶活力等细胞毒性的检测,整体水平的毒性检测也有报道,而缺乏从分子水平进行机制方面的探讨研究.该文就纳米银的抗菌原理及其生物安全性的研究现状进行综述,并对纳米银在毒理学研究的发展方向进行了展望.     

Nephrotoxicity and Genotoxicity of Silver Nanoparticles in Juvenile Rats and Possible Mechanisms of Action

Because of their widespread use and potential adverse effects in young developing organism, this study focused on the nephrotoxicity and genotoxicity of chronic low-dose exposure to silver nanoparticles (AgNPs) in 32 14-day-old male Wistar rats, randomly divided into three groups receiving AgNP solution (3 mg/kg body weight) intraperitoneally for one, two, or three weeks and the untreated control group (eight animals per group). When the rats were eight weeks old, blood creatinine and urine microalbumin were tested, followed by haematoxylin and eosin (H&E) staining. Proteinuria was found in the animals treated with AgNP for three weeks, and H&E staining revealed pathological changes in the kidney sections of this group. DNA damage was detected with the alkaline comet assay in the groups treated for two and three weeks. All results indicate that chronic exposure, even at a low dose, may affect animal health. The main culprit might be increased and time-dependent reactive oxygen species (ROS) production. Highly reactive ROS could cause a major structural damage to proteins and DNA, change the expression of ion channel proteins, and trigger inflammation. The findings of our in vivo experiment raise concern about nephrotoxic and genotoxic effects of silver nanoparticles in young organisms and call for further investigation of nanoparticle properties that can be modified to minimise the risks.     

Toxicological Effects of the Antibiotic Oxytetracycline to an Indian Major Carp Labeo rohita

Oxytetracycline (OTC), an antibacterial agent, is extensively used in aquaculture practices all over the world. Despite its use, the toxicity of OTC to freshwater fish has been scarcely investigated. In this study, Labeo rohita were exposed to different concentrations (20, 40, 60, 80, 100, and 120 mg L^?1) of OTC. Based on the survival-to-mortality ratio, an 80 mg L^?1 concentration was selected for sublethal toxicity analysis. Fish were exposed to the above-mentioned concentration for a period of 25 days, during which fish were killed at the end of every 5 days to analyse certain hematological and enzymological parameters. During the exposure period, a mixed trend was observed in hemoglobin (Hb), hematocrit, mean cell volume, mean cellular Hb, and mean cellular Hb concentration, whereas decreased red blood cell count and increased white blood cell was noted. A biphasic trend was observed in the enzymatic levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in the vital organs (gill, liver and muscle) of fish. The alterations of these parameters lead to the conclusion that these parameters may be used as biomarkers in monitoring OTC toxicity in aquaculture and fisheries farms.     

载银活性炭净水器净化饮水的效率及毒理效应研究

本研究对三种型号载银活性炭净水器净化饮水的效率及对Wistar大鼠和昆明种小鼠的亚慢性毒性和遗传毒性效应进行了试验观察。水质指标的监测结果显示,本地区饮水卫生质量良好,净水器的净水作用不大。亚慢性毒性的试验结果显示,三型净水器净化水显示出不同程度的毒性作用,表现为大鼠出现贫血和动物肝、肾脏器受到一定损害。遗传毒性试验未发现载银活性炭净化水具有致突变作用。     

Effects and Removal of the Antibiotic Sulfadiazine by Eichhornia crassipes: Potential Use for Phytoremediation

Bulletin of Environmental Contamination and Toxicology - The antibiotic sulfadiazine (SDZ) is a challenging threat to the health of aquatic organisms, as it frequently occurs in aquatic ecosystems....     

Toxicity of ZnO Nanoparticles,ZnO Bulk,and ZnCl2 on Earthworms in a Spiked Natural Soil and Toxicological Effects of Leachates on Aquatic Organisms

The present study assessed the uptake and toxicity of ZnO nanoparticles (NPs), ZnO bulk, and ZnCl₂ salt in earthworms in spiked agricultural soils. In addition, the toxicity of aqueous extracts to Daphnia magna and Chlorella vulgaris was analyzed to determine the risk of these soils to the aquatic compartment. We then investigated the distribution of Zn in soil fractions to interpret the nature of toxicity. Neither mortality nor differences in earthworm body weight were observed compared with the control. The most sensitive end point was reproduction. ZnCl₂ was notably toxic in eliminating the production of cocoons. The effects induced by ZnO-NPs and bulk ZnO on fecundity were similar and lower than those of the salt. In contrast to ZnO bulk, ZnO-NPs adversely affected fertility. The internal concentrations of Zn in earthworms in the NP group were greater than those in the salt and bulk groups, although bioconcentration factors were consistently <1. No relationship was found between toxicity and internal Zn amounts in earthworms. The results from the sequential extraction of soil showed that ZnCl₂ displayed the highest availability compared with both ZnO. Zn distribution was consistent with the greatest toxicity showed by the salt but not with Zn body concentrations. The soil extracts from both ZnO-NPs and bulk ZnO did not show effects on aquatic organisms (Daphnia and algae) after short-term exposure. However, ZnCl₂ extracts (total and 0.45-μm filtered) were toxic to Daphnia.     

The Effects of Dietary Silver on Larval Growth in the Echinoderm Lytechinus variegatus

Previous studies have demonstrated that the euryhaline copepod Acartia tonsa is extremely sensitive to dietborne silver (Ag) exposure, with a 20 % inhibition (EC(20)) of survival occurring when copepods are fed algae with 1.6 μg g(-1) dry weight (dw) Ag, corresponding to a waterborne Ag concentration of 0.46 μg l(-1) Ag. In contrast, 43 μg l(-1) Ag is required to elicit similar effects in copepods exposed to Ag by way of water. In the current study, we investigated whether another planktonic marine organism might also be sensitive to dietary Ag. Specifically, we tested larvae of the echinoderm, Lytechinus variegatus in an 18-day study in which larvae were continuously exposed to Ag-laden algae (Isochrysis galbana). After 7 days of exposure, no significant effects were observed on larval growth up to the highest concentration tested (10.68 μg g(-1) dw Ag in algae after exposure to 3.88 μg l(-1) waterborne Ag). After 18 days, significant effects were observed in all Ag treatments resulting in a lowest-observable effect concentration of 0.68 μg g(-1) dw Ag in algae and corresponding waterborne Ag concentration of 0.05-0.07 μg l(-1) Ag (depending on background Ag [see Results]). However, the dose-response relationship was quite flat with a similar level of growth inhibition (approximately 15 %) in all Ag treatments, resulting in an EC(20) of >10.68 μg g(-1) dw Ag in algae (>3.88 μg l(-1) Ag in water). This flat dose-response relationship is characteristic of dietary metal (silver, copper, cadmium, nickel, and zinc) toxicity to copepods as well, although the effect is slightly more robust (approximately 20-30 % inhibition of survival or reproduction). We conclude that echinoderm larvae may be similar to copepods in their sensitivity to dietary Ag, although a better understanding of the mechanisms underlying the apparent flat dose-response relationships is clearly needed.     

Silver Nanoparticles Compromise Neurodevelopment in PC12 Cells: Critical Contributions of Silver Ion,Particle Size,Coating, and Composition

Background

Silver exposures are rising because of the increased use of silver nanoparticles (AgNPs) in consumer products. The monovalent silver ion (Ag⁺) impairs neurodevelopment in PC12 cells and zebrafish.

Objectives and methods

We compared the effects of AgNPs with Ag⁺ in PC12 cells for neurodevelopmental end points including cell replication, oxidative stress, cell viability, and differentiation. First, we compared citrate-coated AgNPs (AgNP-Cs) with Ag⁺, and then we assessed the roles of particle size, coating, and composition by comparing AgNP-C with two different sizes of polyvinylpyrrolidone-coated AgNPs (AgNP-PVPs) or silica nanoparticles.

Results

In undifferentiated cells, AgNP-C impaired DNA synthesis, but to a lesser extent than an equivalent nominal concentration of Ag⁺, whereas AgNP-C and Ag⁺ were equally effective against protein synthesis; there was little or no oxidative stress or loss of viability due to AgNP-C. In contrast, in differentiating cells, AgNP-C evoked robust oxidative stress and impaired differentiation into the acetylcholine phenotype. Although the effects of AgNP-PVP showed similarities to those of AgNP-C, we also found significant differences in potencies and differentiation outcomes that depended both on particle size and coating. None of the effects reflected simple physical attributes of nanoparticles, separate from composition or coating, as equivalent concentrations of silica nanoparticles had no detectable effects.

Conclusions

AgNP exposure impairs neurodevelopment in PC12 cells. Further, AgNP effects are distinct from those of Ag⁺ alone and depend on size and coating, indicating that AgNP effects are not due simply to the release of Ag⁺ into the surrounding environment.