Sustained renal inflammation following 2 weeks of inhalation of occupationally relevant levels of zinc oxide nanoparticles in Sprague Dawley rats

Ameliorative effects of Dunaliella salina microalgae on nanoparticle (ZnO NPs)-induced toxicity in fish

Dunaliella salina (D. salina) is a well-known microalga that contains considerable amounts of nutritious and medicinal bioactive components. This work studied the modulatory role of D. salina against zinc oxide nanoparticle (ZnO NPs)-induced neurotoxic effects in adult zebrafish. Fishes were subjected to 0.69 mg L-1 (1/5th 96-h LC50) for 4 weeks; then, fishes were supplemented with D. salina in the diet for 2 weeks at two levels (15 and 30%). Exposure to ZnO NPs induced a significant increase in the levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OH-dG) while accompanied with downregulation of antioxidant genes in the brain of exposed fishes. Brain neurochemistry and enzyme activities were also altered following ZnO NP exposure. ZnO NPs significantly reduced the neurotransmitters and acetylcholinesterase (AchE) activity while increasing Alzheimer's disease-related proteins and inflammatory response via upregulation of tumor necrosis factor (TNF-α). Additionally, ZnO NPs increased the indices of brain's DNA oxidative damage, increasing brain tissue's metallothionein (MT) and zinc residues. ZnO NPs upregulated the transcription patterns of apoptosis-related genes (casp3 and p53). D. salina dietary co-supplementation with ZnO NPs alleviated the ZnO NPsZnO NP-induced neuro-oxidative damages by lowering the lipid, DNA damage, and inflammatory biomarkers. Besides, D. salina alleviating responses were linked with increasing the levels of the assessed antioxidants. Conclusively, D. salina dietary supplementation induced potential alleviating effects of the ZnO NP-induced neurotoxicity in adult zebrafish.

Zinc oxide nanoparticles promote the aging process in a size-dependent manner

Zinc oxide (ZnO) nanoparticles (NPs) are generally utilized in cosmetic goods, sheds, biosensors, and delivery of drug. As in vitro ideal systems, mesenchymal stem cells (MSCs) are used to test acute toxicity. In the present study, size-dependent cytotoxicity effects of ZnO NPs on MSCs were assessed. Bone marrow and adipose MSCs were treated with ZnO NPs with average sizes of 10-30 and 35-45 nm. The 5 and 10 µg/ml concentrations of ZnO NP were found to be the safe concentrations for the NP sizes of 10-30 and 35-45 nm, respectively. Cell-cycle analysis indicated that the small size of ZnO NPs has more negative effects on the process of cell entry to DNA synthesis when compared to the larger size. The results of the β-galactosidase test showed the promotion of the aging process in the cells treated with the smaller size of ZnO NPs. Both sizes of the NP were found to upregulate the aging-related genes NF-kB and p53 and downregulate the anti-aging gene Nanog. To sum up, the smaller size of ZnO NPs can enhance the aging process in the cells.

Pulmonary Exposure to Copper Oxide Nanoparticles Leads to Neurotoxicity via Oxidative Damage and Mitochondrial Dysfunction

Copper oxide nanoparticles (CuONPs) are widely used in pharmaceutical, food, and textile industries. They have been shown to cause lung, liver, and kidney damage. However, whether an intratracheal instillation of CuONPs would affect the brain and its underlying mechanisms remain poorly studied. In this study, healthy C57BL/6J male mice were equally subdivided into control group, low-dose (30 μg/animal), medium-dose (50 μg/animal), and high-dose (100 μg/animal) CuONPs-treated groups. Mice were subjected to acute exposure of CuONPs via intratracheal instillation. Brain histopathology, inflammatory factors, oxidative stress markers, and mitochondrial function-related protein expression were determined. Our results demonstrated that CuONPs caused a dose-dependent brain damage in mice. Histopathological changes in the brain, elevation of inflammatory factors (Tnf, Il-6), and significant alterations in oxidative stress markers were also observed after treatment with CuONPs. Intriguingly, we did not observe infiltration of macrophage cell. Moreover, Tim23, TFAM, and MFN2 protein expression levels showed the decreasing trend after treatment with CuONPs. Taken together, these results indicate that pulmonary exposure to CuONPs induces pathological damage, inflammation, oxidative stress, and mitochondrial dysfunction in the cerebral cortex, suggesting that neurotoxicity caused by pulmonary exposure of CuONPs needs more attention from the public and relevant departments.

Protective Impact of Edaravone Against ZnO NPs-induced Oxidative Stress in the Human Neuroblastoma SH-SY5Y Cell Line

Extensive applications of ZnO NPs (zinc oxide nanoparticles) in daily life have created concern about their biotoxicity. Zinc oxide nanoparticles induce oxidative stress, inflammation, and apoptosis in neurons. Edaravone applies antioxidant agent and anti-inflammatory impacts in the different cells, as evaluated in both in vitro and in vivo experimental models. This study is designed to explore, how edaravone would avert mitochondrial impairment in human neuronal cells against ZnO NPs-induced toxicity. Accordingly, we analyzed here whether a pretreatment (for 24 h) with edaravone (10-100 μM) would enhance mitochondrial protection in the human neuroblastoma cells SH-SY5Y against ZnO NPs-induced toxicity. We found that edaravone at 25 μM averted the ZnO NPs-induced decrease in the amounts of adenosine triphosphate (ATP), just as on the activity of the complexes I and V. Also, edaravone induced an antioxidant activity by diminishing the levels of lipid peroxidation, protein carbonylation, and protein nitration in the mitochondrial membranes. Edaravone blocked the ZnO NPs-induced transcription factor nuclear factor-κB (NF-κB) upregulation. The inhibition of the heme oxygenase-1 (HO-1) enzyme by zinc protoporphyrin IX (ZnPP IX, 10 μM) smothered the preventive impacts brought about by edaravone with respect to mitochondrial function and inflammation. After this examination, it can be concluded that edaravone caused cytoprotective impacts in an HO-1-dependent manner in SH-SY5Y cells against ZnO NPs-induced toxicity.

Comparative study between zinc oxide nanoparticles synthesis by biogenic and wet chemical methods in vivo and in vitro against Staphylococcus aureus

ZnO nanoparticles (ZnO-NPs) can be used as nano medicine for Staphylococcus aureus infection, which causes deleterious effects on liver, kidney and lung tissue, as it causes catarrhal bronchitis, peri-bronchial oedema, lymphocytic granulomas, oedematous fluid and haemorrhage inside the bronchi, and interstitial pneumonia. In this research ZnO nanoparticle (ZnO-NPs) synthesis by biogenic method using green alga Ulva fasciata and by wet chemical method. Both of them tested in vitro and in vivo against Staphylococcus aureus. The characterization of ZnO-NPs was detected by U.V spectroscopy, Fourier-transform infrared (FTIR), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). In vivo assessment eight groups, each group contain of five rats and the treatment as follow (1) an uninfected control group; (2) an infected group; groups (3), (4), and (5) were injected with biogenic or chemical ZnO-NPs or zinc acetate, as the bulk group, respectively; and groups (6), (7) and (8) were infected and then treated in the same manner as groups (3), (4), and (5), respectively. The blood profile, biochemical parameters, phagocytic activity and histological assessment of liver, kidney and lung tissue of each rat was investigated after 20 days. The rats treated with 5 mg/1 kg natural ZnO-NPs showed improved lung characteristics, and the number of platelets in the infected groups treated with ZnO-NPs from chemical and natural sources (G6 and G7) was close to those in the control group. However, the trend was reversed for regarding lymphocytes, which remained at higher levels in uninfected animals treated with synthetic ZnO-NPs (G4) than in infected rats treated with synthetic ZnO-NPs (G7). Moreover, a significant difference in phagocytic activity was found among all groups compared to that of controls. Compared to control group rats (G1), uninfected rats injected with only natural ZnO-NPs (G3) showed a significant (P < 0.05) improvement in the phagocytic index. We propose that ZnO-NPs produced from natural sources are preferable to those produced from chemical sources for use as nano medicine for the treatment of S. aureus infection in albino rats.

Nanoparticles: An Experimental Study of Zinc Nanoparticles Toxicity on Marine Crustaceans. General Overview on the Health Implications in Humans

The presence of products containing nanoparticles or nanofibers is rapidly growing. Nanotechnology involves a wide spectrum of industrial fields. There is a lack of information regarding the toxicity of these nanoparticles in aqueous media. The potential acute toxicity of ZnO NPs using two marine crustacean species: the copepod Tigriopus fulvus and the amphypod Corophium insidiosum was evaluated. Acute tests were conducted on adults of T. Fulvus nauplii and C. insidiosum. Both test species were exposed for 96 h to 5 increasing concentrations of ZnO NPs and ZnSO4H2O, and the endpoint was mortality. Statistical analysis revealed that the mean LC50 values of both ZnO NPs and ZnSO4H2O (ZnO NPs: F = 59.42; P < 0.0015; ZnSO4H2O: F = 25.57; P < 0.0015) were significantly lower for Tigriopus fulvus than for Corophium insidiosum. This result confirms that the toxic effect could be mainly attributed to the Zn ions, confirming that the dissolution processes play a crucial role in the toxicity of the ZnO NPs.

Biodistribution and acute toxicity of cadmium-free quantum dots with different surface functional groups in mice following intratracheal inhalation

Indium phosphide/zinc sulfate (InP/ZnS) quantum dots (QDs) are presumed to be less hazardous than those that contain cadmium. However, the toxicological profile has not been established. The present study investigated the acute toxicity of InP/ZnS QDs with different surface modifications (COOH, NH₂, and OH) in mice after pulmonary aerosol inhalation. InP/ZnS QDs were able to pass through the blood-gas barrier and enter the circulation, and subsequently accumulated in major organs. No obvious changes were observed in the body weight or major organ coefficients. Red blood cell counts and platelet-related indicators were in the normal range, but the proportion of white blood cells was altered. The InP/ZnS QDs caused varying degrees of changes in some serum markers, but no histopathological abnormalities related to InP/ZnS QDs treatment was observed in major organs except that hyperemia in alveolar septa was found in lung sections. These results suggested that the effects of respiratory exposure to InP/ZnS QDs on the lungs need to be fully considered in future biomedical application although the overall toxicity of quantum dots is relatively low.

Exposure to CuO Nanoparticles Mediates NFκB Activation and Enhances Amyloid Precursor Protein Expression

Amyloid precursor protein (APP) is directly related to Aβ amyloidosis—a hallmark of Alzheimer’s disease (AD). However, the impact of environmental factors upon APP biology and Aβ amyloid pathology have not been well studied. The increased use of nanoparticles (NPs) or engineered nanomaterials (ENMs) has led to a growing body of evidence suggesting that exposure to metal/metal oxide NPs, such as Fe₂O₃, CuO, and ZnO, may contribute to the pathophysiology of neurodegenerative diseases such as AD through neuroinflammation. Our previous studies indicated that exposure to CuO nanoparticles (CuONPs) induce potent in vitro neurotoxicity. Herein, we investigated the effects on APP expression in neuronal cells exposed to different metal oxide NPs. We found a low dose of CuONPs effectively activated the NFκB signaling pathway and increased APP expression. Moreover, the inhibition of p65 expression using siRNA abolished CuONP-mediated APP expression, suggesting that NFκB-regulated APP expression in response to CuONP exposure may be associated with AD pathology.

Curcumin attenuates nephrotoxicity induced by zinc oxide nanoparticles in rats

Curcumin (Cur) effects on renal injury induced by zinc oxide nanoparticles (NZnO) in rats were investigated. NZnO at a dose of 50 mg/kg for 14 days was administered to rats as intoxicated group. In protection group, Cur at a dose of 200 mg/kg was administered for 7 days prior to NZnO treatment and followed by concomitant administration of NZnO for 14 days. Plasma concentrations of uric acid, creatinine (Cr), and blood urea nitrogen (BUN) were detected to evaluate renal injury. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels were determined for evaluation oxidative stress. TUNEL staining and histological changes were also performed. Administration of NZnO caused a significant elevation in the uric acid, Cr, and BUN levels. Oxidative stress was increased in the kidney by NZnO through enhancing MDA contents and reducing activities of SOD and GPx enzymes. According to histological examinations, treatment with NZnO caused proximal tubule damages, which was accompanied by the accumulation of red blood cells, infiltration of inflammatory cells, and reducing glomerular diameters. Significant increase was observed in the apoptotic index of the renal tubules in NZnO-treated rats. In present work, pretreatment of Cur reduced the histological changes, decreased biomarker levels, attenuated apoptotic index, and ameliorated oxidative stress by decreasing the MDA contents and increasing the activities of SOD and GPx enzymes. These findings indicate that Cur effectively protects against NZnO-induced nephrotoxicity in the rats.

Validation of metallothionein, interleukin-8, and heme oxygenase-1 as markers for the evaluation of cytotoxicity caused by metal oxide nanoparticles

Metal oxide nanoparticles have an industrial value, although their harmful effects are also known. Induction of respiratory inflammation through their inhalation is a serious indicator of their toxicity. Although the phenomenon of metal ion release is involved in the induction of inflammation, all metal ions are not necessarily toxic. However, currently, no particular index to evaluate cytotoxicity caused by nanoparticles exists. An index based on biological response is critical. In the present study, we examined the gene expression-based index for nanoparticle-derived cytotoxicity. The cellular effects of six kinds of metal oxide nanoparticles, ZnO, NiO, CuO, MgO, Bi₂O₃, and MoO₃ on A549 cells were examined. It was seen that lactate dehydrogenase (LDH) assay, which is one of the most important assays for assessing cell membrane damage, is inhibited by metal ions released from the metal oxide nanoparticles. In some cases, enzyme activity-based assay was not suitable for the evaluation of cytotoxicity of nanoparticles. ZnO and CuO nanoparticles displayed severe cytotoxicity and enhanced gene expression of heme oxygenase-1 (HO-1) and interleukin-8 (IL-8). The IL-8 gene expression was also increased from Bi₂O₃ exposure. Additionally, the gene expression of metallothionein 2A (MT2A) was enhanced in the ZnO, CuO, and Bi₂O₃ exposed cells. These results suggest that these nanoparticles released metal ions in the cells. The enhancement of HO-1, IL-8, and MT2A gene expressions was related to the cytotoxic activity of metal oxide nanoparticles. Thus, the expression level of these genes is a good indicator of nanotoxicology of metal oxide nanoparticles.

Zinc Oxide Nanoparticles Induced Oxidative DNA Damage, Inflammation and Apoptosis in Rat's Brain after Oral Exposure

Growing evidences demonstrated that zinc oxide nanoparticles (ZnONPs) could reach the brain after oral ingestion; however, the "neurotoxicity of" ZnONPs after oral exposure has not been fully investigated. This study aimed to explore the "neurotoxicity of" ZnONPs (.