Histopathological changes and antioxidant responses in common carp (Cyprinus carpio) exposed to copper nanoparticles

Assessment of toxicity and oxidative stress induced by rare earth oxide nanoparticles in brine shrimp (Artemia salina)

This study meticulously explored the oxidative stress effects induced by lanthanum (III) oxide (La2O3), erbium (III) oxide (Er2O3), and yttrium (III) oxide (Y2O3) nanoparticles on Artemia salina, with the objective of evaluating the environmental toxicity of rare earth oxide nanoparticles. The characterization of the nanoparticles was conducted using a suite of advanced techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential analysis. Artemia salina, a widely recognized model organism in ecotoxicological research, was exposed to these nanoparticles under meticulously controlled laboratory conditions. The investigation focused on quantifying oxidative stress markers, such as reduced glutathione (GSH), malondialdehyde (MDA), and antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST). The findings revealed significant alterations in these biomarkers, indicating nanoparticle-induced oxidative stress, which varied according to the type of nanoparticle and the duration of exposure.

Is the trend toward a sustainable green synthesis of copper oxide nanoparticles completely safe for Oreochromis niloticus when compared to chemical ones?: using oxidative stress, bioaccumulation, and histological biomarkers

Scientists worldwide have noticed that cutting-edge technologies can be used to produce nanoparticles (NPs) in a sustainable and environmentally friendly way, instead of the old methods. However, the effectiveness of this approach for aquatic environments and species still needs to be determined. Therefore, this study aims to compare between the toxicity of green and chemically synthesized copper oxide nanoparticles (GS and CS) CuO NPs at two different concentrations on Nile tilapia (Oreochromis niloticus) using various biomarkers. CuO NPs' formation was proved, and their different characterizations were recorded. Then, the fish samples were randomly allocated in glass aquaria into five groups: one acted as a control group, and the other groups were exposed to two concentrations (25 and 50 mg/L) of GS-CuO NPs and CS-CuO NPs, separately, for 4 days. After the experimental time, in all groups that were exposed to two concentrations of both synthesized CuO NPs, the results revealed that glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and thiobarbituric acid reactive substances (TBARS) levels were elevated in the liver and gills compared to glutathione reduced (GSH) content, which showed a significant decline. Bioaccumulation of Cu was more prevalent in the liver than in the gills, and the highest bioaccumulation capacity was more evident in the groups exposed to CS-CuO NPs. Moreover, the bioaccumulation of Cu caused severe histological changes in the liver and gills. In conclusion, the results suggested that GS-CuO NPs revealed less toxicity than CS-CuO NPs to the examined fish. However, they are still toxic, and their toxic effect cannot be overlooked.

"From shadows to shores"-quantitative analysis of CuO nanoparticle-induced apoptosis and DNA damage in fish erythrocytes: A multimodal approach combining experimental, image-based quantification, docking and molecular dynamics

The usage of copper (II) oxide nanoparticles (CuO NPs) has significantly expanded across industries and biomedical fields. However, the potential toxic effects on non-target organisms and humans lack comprehensive understanding due to limited research on molecular mechanisms. With this study, by combining the 96 h in vivo exposure of crucian carp fish, Carassius carassius, to sub-lethal CuO NPs doses (0.5 and 1 mg/dL) with image-based quantification, and docking and molecular dynamics approaches, we aimed to understand the mechanism of CuO NPs-induced cyto-genotoxicity in the fish erythrocytes. The results revealed that both doses of copper NPs used were toxic to erythrocytes causing oxidative stress response and serious red blood cell morphological abnormalities, and genotoxicity. Docking and 10-ns molecular dynamics confirmed favorable interactions (ΔG = -2.07 kcal mol-1) and structural stability of Band3-CuO NP complex, mainly through formation of H-bonds, implying the potential of CuO NPs to induce mitotic nuclear abnormalities in C. carassius erythrocytes via Band3 inhibition. Moreover, conventional and multiple ligand simultaneous docking with DNA revealed that single, double and triple CuO NPs bind preferentially to AT-rich regions consistently in the minor grooves of DNA. Of note, the DNA-binding strength subtantially increased (ΔG = -2.13 kcal mol-1, ΔG = -4.08 kcal mol-1, and ΔG = -6.03 kcal mol-1, respectively) with an increasing number of docked CuO NPs, suggesting that direct structural perturbation on DNA could also count for the molecular basis of in-vivo induced DNA damage in C. carassius erythrocytes. This study introduces the novel term "erythrotope" to describe comprehensive red blood cell morphological abnormalities. It proves to be a reliable and cost-effective biomarker for evaluating allostatic erythrocyte load in response to metallic nanoparticle exposure, serving as a distinctive fingerprint to assess fish erythrocyte health and physiological fitness.

Bioinspired engineered nickel nanoparticles with multifunctional attributes for reproductive toxicity

Nickel nanoparticles (Ni-NPs) have potential applications in high-tech sectors such as battery manufacturing, catalysis, nanotube printing and textile. Apart from their increasing utilisation in daily life, there are concerns about their hazardous nature as they are highly penetrable in biological systems. The carcinogenic and mutagenic ability of Ni-NPs is evident but the research gaps are still there concerning the safety evaluation of Ni-NPs regarding male reproductive ability. This controlled randomized research was planned to assess the male reproductive toxicity of Ni-NPs in Sprague Dawley rats. Ni-NPs of spherical shape and mean particle size of 56 nm were used in the study, characterized by SEM, EDS and XRD. The twenty-five healthy rats (200-220 g) were used for toxicity investigation of Ni-NPs and divided into five groups; negative control (0 Ni-NPs), placebo group (0.9% saline) and three Ni-NPs treated groups (@ 15, 30 and 45 mg/kg BW). The results of 14 days of intraperitoneal exposure to Ni-NPs revealed that a higher dose (45 mg/kg BW) of Ni-NPs caused a significant reduction in body weight, serum testosterone, daily sperm production while the testis index and Ni accumulation and histological changes (necrosis in basement membrane and seminiferous tubules, vacuole formation) in testicular tissues increased with increasing dose of Ni-NPs. It can be concluded from the study that Ni-NPs have potential reproductive toxicity. This study provided the baseline data of Ni-NPs toxicity for the male reproductive system and can be applied for risk assessment in Ni-NPs based products.

Toxic Effects of Copper Nanoparticles on Paramecium bursaria–Chlorella Symbiotic System

Although many reports have demonstrated that nanoparticles can have a negative effect on aquatic organisms, the toxic effects on symbiotic organisms remain poorly understood. The present study conducts ultrastructure, enzyme activity, and transcriptomics to assess the toxic effects to the Paramecium bursaria–Chlorella symbiotic system from exposure to copper nanoparticles (CuNPs) for 24 h. We found that in both the host and symbiotic algae, CuNP exposure induced high reactive oxygen species level, which leads to oxidative damage and energy metabolism disorder. Moreover, transmission electron micrographs (TEMs) showed that the symbiotic algae in the cytoplasm of P. bursaria were enveloped in the digestive vacuole and digested, and the level of acid phosphatase activity increased significantly within 24 h, which indicated that the stability of the symbiotic system was affected after CuNP exposure. We speculated that the increased energy demand in the host and symbiotic algae resulted from oxidative stress, precipitating the decrease of the photosynthetic products provided to the host, the digestion of the symbiont, and the destruction of the stable symbiotic relationship. The study provides the first insight into the mechanisms of nanoparticles’ toxicity to the symbiotic relationship in the ecosystem, which may help to understand the environmental effects and toxicological mechanisms of nanoparticles.

Review of Copper and Copper Nanoparticle Toxicity in Fish

This review summarizes the present knowledge on the toxicity of copper and copper nanoparticles (CuNPs) to various fish species. In previous decades, the excessive usage of metal and metallic nanoparticles has increased significantly, increasing the probability of the accumulation and discharge of metals in various trophic levels of the environment. Due to these concerns, it is important to understand the toxicity mechanisms of metals and metallic nanoparticles before they lead to unhealthy effects on human health. In this review paper, we specifically focus on the effect of metal copper and CuNPs on different fish organs under different physiochemical parameters of various water bodies. Nowadays, different forms of copper have distinctive and specific usages, e.g., copper sulfate is a well-established pesticide which is used to control the growth of algae in lakes and ponds. Deactivating the fungi enzymes prevents fungal spores from germinating. This process of deactivation is achieved via the free cupric ions, which are established as the most toxic forms of copper. Complexes of copper with other ligands may or may not be bioavailable for use in aquatic organisms. On the other hand, CuNPs have shown cost-effectiveness and numerous promising uses, but the toxicity and availability of copper in a nanoparticle form is largely unknown, Additionally, physiochemical factors such as the hardness of the water, alkalinity, presence of inorganic and organic ligands, levels of pH, and temperature in various different water bodies affect the toxicity caused by copper and CuNPs. However, comprehensive knowledge and data regarding the pattern of toxicity for copper metal ions and CuNPs in marine organisms is still limited. In this review, we carry out a critical analysis of the availability of the toxicological profiles of copper metal ions and CuNPs for different fishes in order to understand the toxicity mechanisms of copper and CuNPs. We believe that this review will provide valuable information on the toxicological profile of copper, which will further help in devising safe guidelines for the usage of copper and CuNPs in a sustainable manner.