Effects Of Copper Oxide Nanoparticles Research Articles

Divergent effects of copper oxide nanoparticles on methanotrophs: Stimulation at low concentrations and inhibition at high concentrations

Methanotrophs represent pivotal microorganisms, integral to the regulation of global methane emissions. Upon introduction into the environment, copper oxide nanoparticles (CuO NPs), a frequently employed category of inorganic nanomaterials, possess the potential to exert influences on methanotrophs. This study investigated the impact of CuO NPs on methanotrophs, showing a clear concentration-dependent response. Under high concentrations, exposure of methanotrophs to CuO NPs induced the production of reactive oxygen species, compromised cell membrane integrity, and resulted in the substantial release of lactate dehydrogenase. The expressions of genes encoding methane monooxygenase were obviously down-regulated. Whereas under low concentrations, a distinct enhancement of bacterial growth and metabolism was observed. The presence of methanotrophs facilitated the release of Cu2+ from CuO NPs, and the Cu2+ stimulated the biosynthesis of particulate methane monooxygenase reversely. Compared to the cellular toxicity of CuO NPs as nanoparticles, the released Cu2+ exerted a more pronounced promoting effect on methanotrophs growth, resulting in an overall strengthened methane metabolism. Significant alterations were observed in genes encoding copper uptake and resistance, cytochrome-related and heme-related proteins. This study provides novel insights into interactions between methanotrophs and nanoparticles, thereby advancing our comprehension of the impact of CuO NPs on methane emissions within an environmental context.

Illuminating new possibilities: Effects of copper oxide nanoparticles on gastrointestinal adenocarcinoma cells in hypoxic condition

Cancer remains a major global health concern, necessitating the development of novel therapeutic approaches. Hypoxia is a common characteristic of solid tumors that plays critical roles in tumor progression, making it a prime target for anticancer therapies. This study aimed to determine the effects of copper oxide nanoparticles (CuONPs) on human gastrointestinal cancer cells in hypoxic condition for the first time. Toxicity of CuONPs was evaluated on human colon and gastric adenocarcinoma cells and normal fibroblasts by alamarBlue assay. Real-time polymerase chain reaction (PCR) was performed to study the effcets of CuONPs on genes involved in cell apoptosis. To elucidate the molecular mechanisms underlying the effects of CuONPs in hypoxic condition, molecular docking was conducted on HIF-1α. Results revealed dose- and cell type-dependent toxic effects of CuONPs, as more significant (p < 0.0001) decrease in viability of LoVo cells (23%) was observed compared to MKN-45 and HDF cells. In addition, CuONPs significantly (p < 0.0001) reduced LoVo cell viability down to 30.2% in hypoxic condition. Gene expression analysis revealed significant (p < 0.0001) over expression of P53 and BAX but downregulation of BCL-2 and CCND1 after treatment with CuONPs. Molecular docking indicated preferable binding of CuONPs to HIF-1α PAS-B domain through interaction with 15 residues with -4.8 Kcal/mol binding energy. Our findings open up new possibilities for modulating HIF-1 activity and inhibiting hypoxia-induced tumor progression.

Size Effects of Copper Oxide Nanoparticles on Boosting Soybean Growth via Differentially Modulating Nitrogen Assimilation.

Nanoscale agrochemicals have been widely used in sustainable agriculture and may potentially affect the nitrogen fixation process in legume crops. The present study investigated the size-effects of copper oxide nanoparticles (CuO NPs) on nitrogen assimilation in soybean (G. max (L.) Merrill) plants, which were treated with different sizes (20 and 50 nm) of CuO NPs at low use doses (1 and 10 mg/kg) for 21 days under greenhouse conditions. The results showed that 50 nm CuO NPs significantly increased the fresh biomass more than 20 nm CuO NPs achieved at 10 mg/kg. The activities of N assimilation-associated enzymes and the contents of nitrogenous compounds, including nitrates, proteins, and amino acids, in soybean tissues were greatly increased across all the CuO NP treatments. The use doses of two sizes of CuO NPs had no impact on the Cu contents in shoots and roots but indeed increased the Cu contents in soils in a dose-dependent fashion. Overall, our findings demonstrated that both 20 and 50 nm CuO NPs could positively alter soybean growth and boost N assimilation, furthering our understanding that the application of nanoscale micro-nutrient-related agrochemicals at an optimal size and dose will greatly contribute to increasing the yield and quality of crops.

Copper Oxide Nanoparticles Induced Growth and Physio-Biochemical Changes in Maize (Zea mays L.) in Saline Soil.

Research on nanoparticles (NPs) is gaining great attention in modulating abiotic stress tolerance and improving crop productivity. Therefore, this investigation was carried out to evaluate the effects of copper oxide nanoparticles (CuO-NPs) on growth and biochemical characteristics in two maize hybrids (YH-5427 and FH-1046) grown under normal conditions or subjected to saline stress. A pot-culture experiment was carried out in the Botanical Research Area of "the University of Lahore", Lahore, Pakistan, in a completely randomized design. At two phenological stages, both maize hybrids were irrigated with the same amount of distilled water or NaCl solution (EC = 5 dS m-1) and subjected or not to foliar treatment with a suspension of CuO-NPs. The salt stress significantly reduced the photosynthetic parameters (photosynthetic rate, transpiration, stomatal conductance), while the sodium content in the shoot and root increased. The foliar spray with CuO-NPs improved the growth and photosynthetic attributes, along with the N, P, K, Ca, and Mg content in the roots and shoots. However, the maize hybrid YH-5427 responded better than the other hybrid to the saline stress when sprayed with CuO-NPs. Overall, the findings of the current investigation demonstrated that CuO-NPs can help to reduce the adverse effects of salinity stress on maize plants by improving growth and physio-biochemical attributes.

Comparing the toxicity effects of copper oxide nanoparticles conjugated with Lapatinib on breast (MDA-MB-231) and lung (A549) cancer cell lines.

In recent years, the increase in cancer morbidity and mortality has presented scientists with a major challenge in developing new therapeutic agents against cancer cells. This study aims to characterize the anticancer effects of copper oxide nanoparticles (NPs) conjugated with Lapatinib (CuO@Lapatinib) on breast and lung cancer cell lines. The physicochemical properties of the NPs were characterized by fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and zeta potential analyses. The antiproliferative potential of the NPs in the breast (MDA-MB-231) and lung (A549) cancer cell lines and a normal cell line (MRC5) was investigated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. Flow cytometry and Hoechst staining were used to evaluate cell apoptosis and cell cycle analysis. The reactive oxygen species (ROS) levels in the treated and control cells were also determined. The NPs were spherical, with a size range of 20-59nm, a DLS size of 338nm, and a zeta potential of -42.9 mV. The half maximal inhibitory concentration (IC50) of CuO@Lapatinib NPs for the normal, breast cancer, and lung cancer cell lines was 105, 98, and 87 µg/ml, respectively. Treatment with CuO@Lapatinib NPs caused considerable apoptosis induction in breast cancer (from 0.65% to 68.96%) and lung cancer cell lines (from 1.11% to 44.11%). Also, an increased level of cell cycle arrest at the S phase was observed in both cancer cell lines. The ROS level in the breast and lung cancer cell lines after treatment with CuO@Lapatinib NPs increased by 3.45 and 21.04 folds, respectively. Nuclear morphological alterations, including chromatin condensation and fragmentation, were observed in both cancer cell lines. This study indicates CuO@Lapatinib is a potent antiproliferative compound with more efficient inhibitory effects on lung cancer than breast cancer cells, which can be related to the higher ROS generation in the A549 cell line.

Pharmacological Effect of Copper Oxide Nanoparticles of Azadirachta indica Leaf Extract and Application for its Antibacterial Properties

ABSTRACT Nanoparticles prepared from bio-reduction agents are of keen interest to researchers around the globe due to their ability to mitigate the harmful effects of chemicals. In this regard, the present study aims to synthesize copper oxide nanoparticles (CuO NPs). CuNPs show a characteristic absorption peak at 347 nm, while SEM reveals the spherical but agglomerated shape of CuNPs of the size within the range of 51.26–56.66 nm. The crystallite size measured by using XRD was found to be within a range of 23.38–46.64 nm for ginger-doped CuO and 26–56 nm for garlic-doped CuO. The X-ray diffraction analysis shows the crystalline structure of copper nanoparticles with prominent peaks. Bragg’s reflection of copper nanoparticles shows diffraction peaks around 2θ =43.4°, 50.3°, and 74.39°, representing [111], [200], and [220] crystallographic planes of face-centered cubic (fcc). The synthesized CuO NPs tested antibacterial properties against various strains of microorganisms, including Escherichia coli, 25 μg/mL 2.3 ± 0.21 and 100 μg/mL 6.5 ± 0.17, Staphylococcus aureus, 25 μg/mL 2.3 ± 0.29 and 100 μg/mL 11.5 ± 1.17, Streptococcus mutans, 25 μg/mL 01.05 ± 0.21 and 100 μg/mL 15.8 ± 0.17, Enterococcus faecalis). The short novelty of Azadirachta indica lies in its potential relevance to human health, as it has been found to possess bioactive compounds with various medicinal properties, such as antimicrobial, antioxidant, and anti-inflammatory activities, making it a promising natural resource for therapeutic applications.

Antihyperlipidemic and antioxidant effects of biogenic copper oxide nanoparticles in diabetic rats

Diabetes mellitus is often associated with metabolic disorders like hyperglycemia, hyperlipidemia, oxidative stress and obesity. Health problems related to these disorders are on a rise globally. Although nanotechnology based approaches have been explored for diabetes treatment, specific information on alleviation of the associated health problem is scanty. Here we report the beneficial effects of copper oxide nanoparticles (CuOnpls) for the control of hyperlipidemia and oxidative stress caused due to diabetes. Wistar rats were fasted overnight and type 2 diabetes was induced by intraperitoneal (i.p.) injection of freshly prepared nicotinamide followed by streptozotocin. Induction of diabetes was confirmed by estimation of blood glucose levels of the animals. Estimation of total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and high density lipoprotein-cholesterol (HDL-c) from the serum was carried out for ascertaining hyperlipidemia. Biogenic CuOnpls (spherical, 88.25 nm diameter) capped with bud extract of Syzygium aromaticum and α-tocopherol were administered in the animals per-oral route. Superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels were determined to evaluate antioxidant activity of CuOnpls. The nanoparticles were characterized for surface chemical groups by FTIR and HRLC-MS. The nanoparticles revealed novel surface groups responsible for site-specific delivery and beneficial effects. Diabetic rats showed enhanced serum BG, TC, TG and LDL levels and reduction in levels of HDL-c, SOD, CAT and GSH. Administration of CuOnpls caused significant reversal of the effects of diabetes on lipid profile and oxidative stress enzymes. The results pointed to the beneficial effects of CuOnpls for management of post-diabetes complications.

Potential Antifungal Effect of Copper Oxide Nanoparticles Combined with Fungicides against Botrytis cinerea and Fusarium oxysporum.

Copper oxide nanoparticles (NCuO) have emerged as an alternative to pesticides due to their antifungal effect against various phytopathogens. Combining them with fungicides represents an advantageous strategy for reducing the necessary amount of both agents to inhibit fungal growth, simultaneously reducing their environmental release. This study aimed to evaluate the antifungal activity of NCuO combined with three fungicide models separately: Iprodione (IPR), Tebuconazole (TEB), and Pyrimethanil (PYR) against two phytopathogenic fungi: Botrytis cinerea and Fusarium oxysporum. The fractional inhibitory concentration (FIC) was calculated as a synergism indicator (FIC ≤ 0.5). The NCuO interacted synergistically with TEB against both fungi and with IPR only against B. cinerea. The interaction with PYR was additive against both fungi (FIC > 0.5). The B. cinerea biomass was inhibited by 80.9% and 93% using 20 mg L-1 NCuO + 1.56 mg L-1 TEB, and 40 mg L-1 NCuO + 12 µg L-1 IPR, respectively, without significant differences compared to the inhibition provoked by 160 mg L-1 NCuO. Additionally, the protein leakage and nucleic acid release were also evaluated as mechanisms associated with the synergistic effect. The results obtained in this study revealed that combining nanoparticles with fungicides can be an adequate strategy to significantly reduce the release of metals and agrochemicals into the environment after being used as antifungals.

Evaluation of copper nanoparticles on growth, organs histology and DNA damage in Japanese quails (Coturnix coturnix japonica)

The effects of Copper oxide nanoparticles (CuO-NPs) have been investigated on human cells and various experimental animals. However, there is a lack of research on the effects of CuO-NPs specifically in Japanese quails. Therefore, the current study aimed to examine the impact of a low and a high doses of CuO-NPs on the growth performance, DNA damage, and histological structures of the liver, kidney, and heart in Japanese quails. In this experiment 120 one-d-old Japanese quails, divided into three experimental groups (n = 40) as follows: Group 1 served as the control group and fed only basic feed, while Group 2 was fed with 6 mg/kg and group 3 received 18 mg/kg body weight CuO-NPs through oral gavage at weekly intervals until 35 days of age. Our findings revealed that, birds fed with 6 mg/kg body weight had significantly (p < 0.05) higher feed intake and weight gain compared to the group receiving the higher dose (18 mg/kg body weight) during weeks 4 and 5 of the study. Both treatment groups indicated DNA damage and histopathological changes, but these effects were more severe in the higher dose group. These results suggested that the lower dose (6 mg/kg) may serve as a growth promoter, whereas the higher dose (18 mg/kg) is detrimental, leading to not only poor growth but also causing DNA damage and histopathological abnormalities in vital organs of the body.

Effect of Copper Oxide Nanoparticles on Prostate Cancer PC3 Cells

Copper oxide (CuO NPs) nanoparticles were synthesized by green synthesis and characterized by UV-Vis spectroscopy, FT-IR spectroscopy, SEM and EDX analysis. The shape of the CuO nanoparticles obtained is approximately spherical and their particle sizes range from 40 to 85 nm. According to the experimental results, two peaks at 305 and 318 nm in the 270-400 nm range in the UV-Vis absorption spectrum and one peak at 536 cm-1 in the FT-IR spectrum confirm the presence of copper oxide nanoparticles. In addition, the presence of biomolecules in aesculus hippocastanum(horse chestnut) extract on the surface of the copper oxide nanoparticles synthesized by green synthesis was determined by the peaks seen in the range of 3300 cm-1 - 1000 cm-1 in the FTIR spectrum. The images, shape and size of the copper oxide nanoparticles were determined by SEM, and the weight percent of the elements were determined by EDX. PC3 prostate cell lines were used in the study. After measuring the cytotoxic effect of the agents used in the study on prostate cancer cells, the apoptotic effect of this effect was determined by Hoechst/propidium iodide (HOPI) staining. Graphpad prism program was used to compare all parameters between groups, and "one-way analysis of variance" (one-way ANOVA) method and dunnet's test were applied to test whether there was any difference between at least two groups. It has been determined that the drug obtained from copper oxide nanoparticles has a cytotoxic effect on PC3 prostate cancer cells and this effect occurs through the apoptosis pathway.

Changes in the mitochondrial function of fibroblast-like cells exposed to copper oxide nanoparticles

Introduction. Mitochondria are targets for almost all types of damaging agents, including toxins and oxidative stress. There is no doubt that possible effects on mitochondria should be taken into account in a comprehensive assessment of metal toxicity. Our objective was to establish changes in the mitochondrial function under the effect of copper oxide nanoparticles in vitro.&#x0D; Material and methods. A monolayer culture of human lung fibroblast-like cells of the FLECH-104 line were exposed to copper oxide nanoparticles (CuO NPs) 21±4 nm in size, final concentrations of which in the media were 25, 50, and 100 μg/mL. We measured the rate of oxygen consumption by the cells and its changes under the influence of modulators, such as oligomycin, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone, and rotenone combined with antimycin A. We estimated parameters of mitochondrial function and the bioenergetics index.&#x0D; Results. At the concentration of 100 μg/mL in the incubation medium, CuO NPs induced changes in the culture of fibroblast-like cells that impeded further assessment of the mitochondrial function. At the lower concentrations of 25 and 50 μg/mL, we observed a dose-dependent trend toward a decrease in ATP-related respiration and bioenergetics index. It is noteworthy that the concentration of 25 μg/mL increased the maximum and reserve respiratory capacity of the cells, which was probably related to the dual effect of copper as a toxicant and an essential element.&#x0D; Limitations of the study. The study was conducted using only one cell line and three concentrations of CuO nanoparticles suspended in the culture medium.&#x0D; Conclusion. We established that copper oxide nanoparticles, when added to the incubation medium, have a multidirectional effect on the mitochondrial function of fibroblast-like cells potentially attributed to biotic properties of this metal.

Antibacterial Effect of Copper Oxide Nanoparticles Prepared by Laser Production in Water Against Staphylococcus aureus and Escherichia coli

Antibacterial Effect of Copper Oxide Nanoparticles Prepared by Laser Production in Water Against Staphylococcus aureus and Escherichia coli

Microalgae-bacteria interaction in alginate beads prevents the negative effect of copper oxide nanoparticles on the growth and metabolism of Scenedesmus sp.

Microalgae-bacteria interaction in alginate beads prevents the negative effect of copper oxide nanoparticles on the growth and metabolism of Scenedesmus sp.

Numerical investigation on heat and mass transfer characteristics of inclined plate falling film absorption with nano-lithium bromide solution

Nanofluids play an essential role in enhancing heat and mass transfer in falling film absorption processes. To reveal the underlying mechanisms of enhanced absorption by nanoparticles at the gas–liquid interface, an innovative model considering the Marangoni effect is proposed for falling film absorption on an inclined plate. The effects of copper oxide nanoparticles on heat and mass transfer for the inclined plate falling film absorption, utilizing lithium bromide solution as the working fluid, are numerically studied using the software COMSOL Multiphysics. The accuracy of the numerical model is verified by experimental and simulation results, showing superior agreement when the Marangoni effect is incorporated. The vapor absorption performance of lithium bromide solution is significantly enhanced by the addition of nanoparticles. Surface tension amplifies temperature and concentration gradients, playing a pivotal role in augmenting heat and mass transfer through the Marangoni effect. The largest temperature and concentration gradients occur at the gas–liquid interface. The interfacial heat transfer coefficient and mass transfer coefficient decrease along the length of the inclined plate and gradually stabilize at 15.01 W·m−2·K−1 and 1.12 × 10−4 m·s−1, respectively.

Quercetin and l-Arginine Ameliorated the Deleterious Effects of Copper Oxide Nanoparticles on the Liver of Mice Through Anti-inflammatory and Anti-apoptotic Pathways

The widespread use and applications of copper oxide nanoparticles (CuO NPs) in daily life make human exposure to these particles inevitable. This study was carried out to investigate the deteriorations in hepatic and serum biochemical parameters induced by CuO NPs in adult male mice and the potential ameliorative effect of l-arginine and quercetin, either alone or in combination. Seventy adult male mice were equally allocated into seven groups: untreated group, l-arginine, quercetin, CuO NPs, arginine + CuO NPs, quercetin + CuO NPs, and quercetin + arginine + CuO NPs. Treating mice with CuO NPs resulted in bioaccumulation of copper in the liver and consequent liver injury as typified by elevation of serum ALT activity, reduction in the synthetic ability of the liver indicated by a decrease in the hepatic arginase activity, and serum total protein content. This copper accumulation increased oxidative stress, lipid peroxidation, inflammation, and apoptosis as manifested by elevation in malondialdehyde, nitric oxide, tumor necrosis factor-α, the expression level of caspase-3 and bax quantified by qPCR, and the activity of caspase-3, in addition to the reduction of superoxide dismutase activity. It also resulted in severe DNA fragmentation as assessed by Comet assay and significant pathological changes in the liver architecture. The study proved the efficiency of quercetin and l-arginine in mitigating CuO NPs-induced sub-chronic liver toxicity due to their antioxidant, anti-inflammatory, and anti-apoptotic properties; ability to inhibit DNA damage; and the potential as good metal chelators. The results of histopathological analysis confirmed the biochemical and molecular studies.

Comparative Evaluation of the Effect of Copper Oxide and Copper Sulfate Nanoparticles on Structural and Functional Characteristics of Thalassiosira weissflogii under Conditions of Enrichment Cultivation // Russian Journal of Plant Physiology.

The effect of copper oxide nanoparticles (500, 1000, 2000 μg/L) and copper ions (37.5, 75, 150 μg/L) on the morphological, structural-functional, and fluorescent parameters of diatom microalgae Thalassiosira weissflogii under conditions of long-term cultivation was studied. It was shown that copper in ionic form is more toxic for this microalgae species than in the form of a nanooxide. The nature of the effect of copper in ionic and nanoform on cells Thalassiosira weissflogii has both similarities and significant differences. The difference in the effect of the studied toxicants on the growth of algae and the performance of photosynthetic apparatus was revealed. The addition of copper ions into the cultivation medium led to long lag phase during the initial stage of the experiment, followed by the restoration of growth on days 3–6 of exposure. An increase in the concentration of copper oxide nanoparticles in the medium caused inhibition of algae growth without a pronounced lag phase. With an increase in the concentration of Cu2+ in the culture medium, a decrease in the quantum efficiency of light energy utilization by the PS II photosynthetic complex and the maximum relative electron transport rate were observed, while copper oxide nanoparticles had an insignificant effect on the efficiency of the photosynthetic apparatus ofThalassiosira weissflogii. With an increase in the concentration of copper, both in the ionic form and in the form of nanooxide, increase in cell volume, changes of cell shape and granularity, an increase in the production of reactive oxygen species, suppression of enzymatic activity and a decrease in autofluorescence values of individual cells in the red region of the spectrum were observed.

Effect of Copper Oxide Nanoparticles on the Performance of Polyvinyl Chloride Membranes

AbstractPolyvinyl chloride (PVC)/copper oxide (CuO) nanocomposite membranes were fabricated at different CuO nanoparticles loading levels using the phase inversion method. The fabricated membranes were tested through two filtration cycles in a submerged membrane system to remove bovine serum albumin (BSA) from water. Results showed that the hydrophilicity and porosity of the nanocomposite membranes were enhanced with an increase of CuO nanoparticles loading. The field emission electron microscopy images from the membrane surface demonstrated that the number and size of pores increased with addition of CuO nanoparticles. The atomic force microscopy test displayed that all nanocomposite membranes showed lower surface roughness in comparison to neat PVC membranes. The obtained results from membrane performance indicated that the irreversible fouling ratio for neat PVC membranes in the first and second cycles of filtration decreased for PVC/CuO‐1.5 membranes. Compared with the neat PVC membrane, the membrane containing CuO exhibited better capabilities such as the enhanced permeation flux, higher BSA rejection rate, and better antifouling properties.

Effects of CuO nanoparticles in composted sewage sludge on rice-soil systems and their potential human health risks

The release of metal-based nanoparticles (MNPs) into sewage systems is worrisome due to their potential impact on crop-soil systems that are amended with sewage sludge. This study aimed to investigate the effects of copper oxide nanoparticles (CuO NPs) in composted sewage sludge (CSS) on rice-soil systems and to assess the health risks associated with consuming CuO NP-contaminated rice produced by CSS amendment. CSS was treated with three doses of CuO NPs, resulting in Cu levels below the sludge limits (1500 mg Cu kg−1) for reuse as a soil amendment. Results showed that CuO NPs in CSS at environmentally acceptable levels had no negative effect on rice growth and yield. In fact, they enhanced biomass production, tillering capacity, and soil fertility by increasing N and K levels in the soil. In addition, CuO NPs in CSS (450–1450 mg Cu kg−1) promoted the accumulation of macro- and micro-minerals in rice grains, thereby improving the nutritional value of rice. However, Cu contamination in CSS led to elevated levels of toxic metals, especially As, in rice grains, posing potential health risks to both adults and children. In the presence of higher CuO NPs contamination in CSS, the hazard quotient of As exceeded one, indicating an increased risks of toxic metal exposure via rice consumption. This study raises concerns about potential long-term threats to human health posed by MNPs contamination in CSS and highlights the need to reevaluate the permissible limits of hazardous elements in sludge to ensure its safe reuse in agriculture.

Effects of copper oxide nanoparticles on reproductive system of zebrafish

Copper oxide nanoparticles (CuO NPs) were regarded as the versatile materials in daily life and the in-depth evaluation of their biological effects is of great concern. Herein the female and male zebrafishes were chosen as the model animals to analyze the reproductive toxicity caused by CuO NPs at low concentration (10, 50 and 100 μg/L) After 20-days exposure, the structure of zebrafish ovary and testis were impaired. Moreover, the contents of 17β-estradiol (E2) in both females and males were increased, while the contents of testosterone (T) were decreased, indicating the imbalanced sex hormones caused by CuO NPs. The expression of genes along the hypothalamic pituitary-gonad (HPG) axis, were examined with quantitative real-time PCR to further evaluate the toxic mechanisms. Meanwhile, the levels of erα/er2β and cyp19a in female zebrafishes and erα/er2β, lhr, hmgra/hmgrb, 3βhsd and 17βhsd in male zebrafishes were obviously up-regulated. While, the level of αr was obviously down-regulated in female and male zebrafishes. Thus, the obtained data uncovered that long-term exposure of CuO NPs with low dose could trigger the endocrine disorder, resulting in the disturbance of E2 and T level, inhibition of gonad development, and alteration of HPG axis genes. In brief, this study enriched the toxicological data of NPs on aquatic vertebrates and provided the theoretical support for assessing the environmental safety of NPs.

Biochemical and histopathological effects of copper oxide nanoparticles exposure on the bivalve Chambardia rubens (Lamarck, 1819).

Copper nanoparticles are widely incorporated into many applications, including air and liquid filters, wood preservatives, batteries, thermal and electrical conductivity, inks and skin products. Their potential toxicity and environmental fate, however, are poorly studied in the freshwater bivalves. The aim of the present study was to evaluate the different effects of copper oxide nanoparticles and ionic copper on the digestive glands and gills of the mussel Chambardia rubens. Mussels were treated with 100 and 1000 µg Cu L-1 of copper oxide nanoparticles (CuONPs) or ionic copper (Cu2+) for 3, 7, and 14 days. The Cu accumulation and markers of oxidative stress in the digestive glands and gills were evaluated. The results show that the digestive gland collected higher levels of the two forms of copper than the gills. Exposure to CuONPs or Cu2+ induced significant elevations in superoxide dismutase, glutathione peroxidase and lipid peroxidation. Notably, a significant decrease was observed in the glutathione levels after exposure to both copper forms. CuONPs only induced a significant increase in glutathione reductase and glutathione S-transferase. The ionic copper only induced a significant decrease in catalase activities in the gill tissues. Overall, CuONPs and Cu2+ provoked oxidative stress, and further research is needed to clarify their genotoxic and neurotoxic effects on freshwater mussels and other biota.