Toxicity and effects of copper oxide nanoparticles on cognitive performances in rats

Effect of sub-acute exposure of metal-organic framework-199 on cognitive function and oxidative stress level of brain tissue in rat

Metal-Organic Framework-199 (MOF-199) is a subgroup of MOFs that is utilized in different medical fields such as drug delivery. In the current study, the effect of sub-acute exposure to MOF-199 on spatial memory, working memory, inflammatory mediators' expression, and oxidative stress level of brain tissue has been investigated. Thirty-two male Wistar rats were randomly divided into four groups as vehicle, MOF-199 at doses 0.3, 3, or 6 mg/kg. After four injections of relevant interventions via tail vein during 14 days, behavioral parameters were investigated using Y-maze and Morris Water Maze (MWM) tests. Oxidative stress was measured by ferric reducing antioxidant power (FRAP) and thiobarbituric acid-reacting substance (TBARS) tests. The expression levels of TNF-α and IL-1β were assessed by quantitative real-time reverse-transcription PCR (qRT-PCR). No significant differences were observed in working memory, spatial learning and memory of MOF-199 receiving rats. Additionally, the level of oxidative stress and inflammatory genes expression were not remarkably changed in the brain tissues of MOF-199 treated rats. Despite the lack of remarkable toxic effects of sub-acute exposure to MOF-199, more studies with a longer duration of administration are necessary to use this substance for drug delivery systems in diseases related to the nervous system.

Acute exposure to tenorite nanoparticles induces phenotypic and behavior alterations in zebrafish larvae

Tenorite or copper oxide nanoparticles (CuO NPs) are extensively used in biomedical fields due to their unique physicochemical properties. Increased usage of these NPs leads to release in the environment, affecting varied ecosystems and the biota within them, including humans. The effect of these NPs can be evaluated with zebrafish, an excellent complementary model for nanotoxicity studies. Previous reports focusing on CuO NPs-induced teratogenicity in zebrafish development have not elucidated the phenotypical changes in detail. In most of the studies, embryos at 3 hpf with a protective chorion layer were exposed to CuO NPs, and their effect on the overall developmental process is studied. Hence, in this study, we focused on the effect of acute exposure to CuO NPs (96-120 hpf) and its impact on zebrafish larvae. Larvae were exposed to commercially available CuO NPs (<50 nm) at various concentrations to obtain the LC50 value (52.556 ppm). Based on the LC50, three groups (10, 20, and 40 ppm) were taken for further analysis. Upon treatment, bradycardia, and impaired swim bladder (reduced/absence of inflation) were found in the treated groups along with alterations in the erythrocyte levels. Also, the angles and distance between the cartilages varied in the treated larvae affecting their craniofacial structures. There was a significant behavior change, as evidenced by the reduced touch escape response and locomotion (speed, distance, time mobile, time frozen, and absolute turn angle). Further, the acetylcholinesterase activity was reduced. Overall, our results suggest that acute exposure to CuO NPs elicits morphological defects in zebrafish larvae.

Synthesis, biomedical applications, and toxicity of CuO nanoparticles

Versatile nature of copper oxide nanoparticles (CuO NPs) has made them an imperative nanomaterial being employed in nanomedicine. Various physical, chemical, and biological methodologies are in use for the preparation of CuO NPs. The physicochemical and biological properties of CuO NPs are primarily affected by their method of fabrication; therefore, selectivity of a synthetic technique is immensely important that makes these NPs appropriate for a specific biomedical application. The deliberate use of CuO NPs in biomedicine questions their biocompatible nature. For this reason, the present review has been designed to focus on the approaches employed for the synthesis of CuO NPs; their biomedical applications highlighting antimicrobial, anticancer, and antioxidant studies; and most importantly, the in vitro and in vivo toxicity associated with these NPs. This comprehensive overview of CuO NPs is unique and novel as it emphasizes on biomedical applications of CuO NPs along with its toxicological assessments which would be useful in providing core knowledge to researchers working in these domains for planning and conducting futuristic studies. KEY POINTS: • The recent methods for fabrication of CuO nanoparticles have been discussed with emphasis on green synthesis methods for different biomedical approaches. • Antibacterial, antioxidant, anticancer, antiparasitic, antidiabetic, and antiviral properties of CuO nanoparticles have been explained. • In vitro and in vivo toxicological studies of CuO nanoparticles exploited along with their respective mechanisms.

Potential Environmental and Health Implications from the Scaled-Up Production and Disposal of Nanomaterials Used in Biosensors

Biosensors often combine biological recognition elements with nanomaterials of varying compositions and dimensions to facilitate or enhance the operating mechanism of the device. While incorporating nanomaterials is beneficial to developing high-performance biosensors, at the stages of scale-up and disposal, it may lead to the unmanaged release of toxic nanomaterials. Here we attempt to foster connections between the domains of biosensors development and human and environmental toxicology to encourage a holistic approach to the development and scale-up of biosensors. We begin by exploring the toxicity of nanomaterials commonly used in biosensor design. From our analysis, we introduce five factors with a role in nanotoxicity that should be considered at the biosensor development stages to better manage toxicity. Finally, we contextualize the discussion by presenting the relevant stages and routes of exposure in the biosensor life cycle. Our review found little consensus on how the factors presented govern nanomaterial toxicity, especially in composite and alloyed nanomaterials. To bridge the current gap in understanding and mitigate the risks of uncontrolled nanomaterial release, we advocate for greater collaboration through a precautionary One Health approach to future development and a movement towards a circular approach to biosensor use and disposal.

Characterization and Toxicity Analysis of Lab-Created Respirable Coal Mine Dust from the Appalachians and Rocky Mountains Regions

Coal mine workers are continuously exposed to respirable coal mine dust (RCMD) in workplaces, causing severe lung diseases. RCMD characteristics and their relations with dust toxicity need further research to understand the adverse exposure effects to RCMD. The geographic clustering of coal workers’ pneumoconiosis (CWP) suggests that RCMD in the Appalachian region may exhibit more toxicity than other geographic regions such as the Rocky Mountains. This study investigates the RCMD characteristics and toxicity based on geographic location. Dissolution experiments in simulated lung fluids (SLFs) and in vitro responses were conducted to determine the toxicity level of samples collected from five mines in the Rocky Mountains and Appalachian regions. Dust characteristics were investigated using Fourier-transform infrared spectroscopy, scanning electron microscopy, the BET method, total microwave digestion, X-ray diffraction, and X-ray photoelectron spectroscopy. Inductively coupled plasma mass spectrometry was conducted to determine the concentration of metals dissolved in the SLFs. Finer particle sizes and higher mineral and elemental contents were found in samples from the Appalachian regions. Si, Al, Fe, Cu, Sr, and Pb were found in dissolution experiments, but no trends were found indicating higher dissolutions in the Appalachian region. In vitro studies indicated a proinflammatory response in epithelial and macrophage cells, suggesting their possible participation in pneumoconiosis and lung diseases development.

Hippocampal toxicity of metal base nanoparticles. Is there a relationship between nanoparticles and psychiatric disorders?

Metal base nanoparticles are widely produced all over the world and used in many fields and products such as medicine, electronics, cosmetics, paints, ceramics, toys, kitchen utensils and toothpastes. They are able to enter the body through digestive, respiratory, and alimentary systems. These nanoparticles can also cross the blood brain barrier, enter the brain and aggregate in the hippocampus. After entering the hippocampus, they induce oxidative stress, neuro-inflammation, mitochondrial dysfunction, and gene expression alteration in hippocampal cells, which finally lead to neuronal apoptosis. Metal base nanoparticles can also affect hippocampal neurogenesis and synaptic plasticity that both of them play crucial role in memory and learning. On the one hand, hippocampal cells are severely vulnerable due to their high metabolic activity, and on the other hand, metal base nanoparticles have high potential to damage hippocampus through variety of mechanisms and affect its functions. This review discusses, in detail, nanoparticles' detrimental effects on the hippocampus in cellular, molecular and functional levels to reveal that according to the present information, which types of nanoparticles have more potential to induce hippocampal toxicity and psychiatric disorders and which types should be more evaluated in the future studies.

Therapeutic nanoparticles in the brain: A review of types, physicochemical properties and challenges

One of the main obstacles in the treatment of neurological diseases, perhaps the biggest one, is the delivery of therapeutic compounds to the central nervous system, and nanoparticles are promising tools to overcome this challenge. Different types of nanoparticles may be used as delivery systems, including liposomes, carbon nanotubes, and dendrimers. Nevertheless, these nanoparticles must display characteristics to be useful in brain drug delivery, such as stability, permeability to blood vessels, biocompatibility, and specificity. All of these aspects are intrinsically related to the physicochemical properties of nanoformulations: size, composition, electric charge, hydrophobicity, mucoadherence, permeability to the blood-brain barrier, and many others. Furthermore, there are challenging hindrances involved in the development and application of nanoparticles - hence the importance of studying and understanding these pharmaceutical tools.

Hepatorenal protective effect of nano-curcumin against nano‑copper oxide-mediated toxicity in rats: Behavioral performance, antioxidant, anti-inflammatory, apoptosis, and histopathology

BACKGROUND

Metal oxide nanoparticles (NPs) induce oxidative stress that can cause cellular toxicity. A natural antioxidant that can be used to protect tissues from oxidative stress is curcumin.

PURPOSE

In the present study, we evaluated the protective effect of curcumin nanoparticles (curcumin-NPs) against copper oxide nanoparticles (CuO-NPs)-mediated hepatorenal effects on behavioral performance, biochemical markers, antioxidants, inflammation, apoptosis, and histopathology in rats.

STUDY DESIGN

Twenty Wistar adult male rats were randomly divided into four groups (n = 5); Group Ι served as a control, group ΙΙ was orally gavaged with curcumin-NPs (100 mg/Kg), group ΙΙI orally received CuO-NPs (100 mg/kg), and group ΙV received both CuO-NPs and curcumin-NPs orally for 14 days.

METHODS

Behavioral performance, biochemical markers, antioxidants, inflammatory mediators, and apoptotic gene expression were evaluated in addition to histopathological and immunohistochemical examination.

RESULTS

The results revealed that rats exposed to CuO-NPs suffered from behavioral alterations and hepatic and renal damages, which indicated by a marked elevation of serum biochemical parameters, including alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, urea, uric acid, and creatinine and a decline of total protein. Moreover, there was a significant downregulation in the expression of antioxidants genes, whereas inflammatory mediators expression were upregulated. The histopathological and immunohistochemical examination also corroborated these findings. In contrast, rats co-treated with curcumin-NPs exhibited better behavioral performance, biochemical profile, gene expression, histological architecture, and immunohistochemical staining results.

CONCLUSION

These findings strongly indicated that curcumin-NPs exert significant protection against the behavioral and hepatorenal disorders induced by CuO-NPs toxicity by modulating oxidative stress regulators and gene expression.

Acute titanium dioxide nanoparticles exposure impaired spatial cognitive performance through neurotoxic and oxidative mechanisms in Wistar rats

CONTEXT

Titanium dioxide nanoparticles (TiO2-NPs) are used in many commercial products. However, their effects on human and animal organism remained to be clarified.

OBJECTIVE

The present study aimed to investigate the effects of TiO2-NPs on the behavioural performance, monoamine neurotransmitters and oxidative stress in the rat brain.

MATERIAL AND METHODS

Rats were injected intravenously with a single dose of TiO2-NPs (20 mg/kg body weight) and were subjected to cognitive and emotional tests using Morris water maze and elevated plus maze.

RESULTS

Cognitive capacity as well as the emotional reactivity were significantly disrupted, in TiO2-NPs-administered rats compared to control group. These behavioural effects were correlated with changes in brain neurotransmitter contents reflected by a significant increase in dopamine and a decrease in serotonin levels. TiO2-NPs also induced oxidative stress in the brain manifested by increased levels of H2O2 and malondialdehyde, associated with antioxidant enzymes activities disturbance, in particular, superoxide dismutase and catalase activities. Moreover, TiO2-NPs administration caused histological damages in the brain tissue with abundant lymphocytic clusters, capillary dilations, vascular congestion and oedema.

CONCLUSIONS

Acute intravenous injection of TiO2-NPs impaired behaviour performances through brain biochemical and structural changes and precautions should be taken to their usage in food additive and medical applications.

Integrated in silico analysis for the identification of key genes and signaling pathways in copper oxide nanoparticles toxicity

Copper oxide nanoparticles (CuO-NPs) are used in various industrial and commercial products due to their enhanced physicochemical properties. The vast consumption increases their exposure in the environment, thereby affecting the ecosystem. Even with the rise in research towards understanding their toxicity, the major signaling cascades and key genes involved in CuO-NPs remain elusive due to the various attributes involved (size, shape, charge, coating in terms of nanoparticles, and dose, duration, and species used in the experiment). The focus of the study is to identify the key signaling cascades and genes involved in CuO-NPs toxicity irrespective of these attributes. CuO-NPs related microarray expression profiles were screened from GEO database and were subjected to toxicogenomic analysis to elucidate the toxicity mechanism. In silico tools were used to obtain the DEGs, followed by GO and KEGG functional enrichment analysis. The identified DEGs were then analyzed to determine major signaling pathways and key genes. Module and centrality parameter analysis was performed to identify the key genes. Further, the miRNAs and transcription factors involved in regulating the genes were predicted, and their interactive pathways were constructed. A total of 44 DEGs were commonly present in all the analysed datasets and all of them were downregulated. GO analysis reveals that most of the genes were enriched in functions related to cell division and chemotaxis. Cell-cycle, chemokine, cytokine-cytokine receptor interaction, and p53 signaling pathways were the key pathways with Cdk1 as the major biomarker altered irrespective of the variables (dosage, duration, species used, and surface coating). Overall, our integrated toxicogenomic analysis reveal that Cdk1 regulated cell cycle and cytokine-cytokine signaling cascades might be responsible for CuO-NPs toxicity. These findings will help us in understanding the mechanisms involved in NPs toxicity.

Neuropathological and Cognitive Effects Induced by CuO-NPs in Rats and Trials for Prevention Using Pomegranate Juice

Copper oxide nanoparticles (CuO-NPs) are extensively utilized in several industries and in pharmaceutical production. This excess exposure elevates the concern about its expected poisonous impacts on humans and animals. Pomegranate juice (PJ) is a natural source of polyphenols and exhibits potent antioxidant activities. Our experiment intended to explore the neurobehavioral and toxicopathological impacts of CuO-NPs and to explain the mechanistic role of PJ to reduce their toxicity. Thirty Wistar albino rats received the subsequent materials through oral gavage, every day for 28d: (1) normal saline, (2) 3 mL/kg bwt PJ, (3) 6 mL/kg bwt PJ, (4) 300 mg/kg bwt CuO-NPs, (5) CuO-NPs + 3 mL/kg bwt PJ, (6) CuO-NPs + 6 mL/kg bwt PJ. Continuous exposure to CuO-NPs caused a significant elevation of MDA levels and reduction of total antioxidant capacity associated with remarkable pathological alterations in all brain regions including cerebrum, hippocampus and cerebellum. Progressive decline of memory along with cognitive and psychiatric disturbances were observed in rats exposed to CuO-NPs not in PJ co-treated rats. Continuous exposure to CuO-NPs caused over expression of the immunohistochemical markers of caspase-3, iNOS and GFAP altogether with DAN fragmentation and down-regulation of HO-1 and Nrf2 gene in the whole brain tissues. Conversely, rats co-treated with PJ showed dose dependent improvements in the entire toxicological, behavioral, and pathological parameters. We showed that PJ had the ability to reduce the oxidative stress damage via up-regulation of HO-1 and Nrf2 genes in the brain. So that PJ had the ability to protect the brain and DNA from further damage.

The Application of Nanotechnology for the Diagnosis and Treatment of Brain Diseases and Disorders

Brain is by far the most complex organ in the body. It is involved in the regulation of cognitive, behavioral, and emotional activities. The organ is also a target for many diseases and disorders ranging from injuries to cancers and neurodegenerative diseases. Brain diseases are the main causes of disability and one of the leading causes of deaths. Several drugs that have shown potential in improving brain structure and functioning in animal models face many challenges including the delivery, specificity, and toxicity. For many years, researchers have been facing challenge of developing drugs that can cross the physical (blood–brain barrier), electrical, and chemical barriers of the brain and target the desired region with few adverse events. In recent years, nanotechnology emerged as an important technique for modifying and manipulating different objects at the molecular level to obtain desired features. The technique has proven to be useful in diagnosis as well as treatments of brain diseases and disorders by facilitating the delivery of drugs and improving their efficacy. As the subject is still hot, and new research findings are emerging, it is clear that nanotechnology could upgrade health care systems by providing easy and highly efficient diagnostic and treatment methods. In this review, we will focus on the application of nanotechnology in the diagnosis and treatment of brain diseases and disorders by illuminating the potential of nanoparticles.

The Beneficial Role of Filipendula ulmaria Extract in Prevention of Prodepressant Effect and Cognitive Impairment Induced by Nanoparticles of Calcium Phosphates in Rats

Mineral components of dental composites are used in many medical and dental applications, including preventive, restorative, and regenerative dentistry. To evaluate the behavioural alterations induced by nanosized particles of novel dental composites, by means of depressive level and cognitive functions, experimental groups of rats were chronically administered with nanosized hydroxyapatite (HA), tricalcium phosphate (TCP), and amorphous calcium phosphate (ACP) with or without simultaneous application of Filipendula ulmaria L. (FU) methanolic extract. The significant prodepressant action was observed in groups solely treated with HA and ACP. Besides, prolonged treatment with ACP also resulted in a significant decline in cognitive functions estimated in the novel object recognition test. The adverse impact of calcium phosphates on estimated behavioural functions was accompanied by increased oxidative damage and apoptotic markers in the prefrontal cortex, as well as diminished specific neurotrophin (BDNF) and gabaergic expression. The results of our investigation showed that simultaneous antioxidant supplementation with FU extract prevented calcium phosphate-induced behavioural disturbances, as well as prooxidative and apoptotic actions, with the simultaneous restoration of BDNF and GABA-A receptors in the prefrontal cortex. These findings suggest that FU may be useful in the prevention of prodepressant impact and cognitive decline as early as the manifestation of calcium phosphate-induced neurotoxicity.