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

There is increasing scientific evidences that the physical and chemical properties of manufactured nanoparticles lead to an increase in their bioavailability and toxicity. Among them Copper oxide nanoparticles (CuO-NPs) are widely used in different fields. However their potential adverse effects namely on brain functions are still discussed. Thus, the present study aimed to investigate the subacute oral toxicity and effects of CuO-NPs on cognitive performances in rats. Rats were randomly divided into three groups of 8 animals each, a control group received a dose 9‰ sodium chloride and the other groups received a suspension of CuO-NPs at doses of 250 and 500 mg/kg through oral gavage for 14 consecutive days. Multiple behavioral tests showed that CuO-NPs caused little changes in memory and learning performances as well as the locomotors activity, while the anxiety index increased. Copper NPs exposure increased also the liver and stomach relative weights and altered some blood biochemical parameters.

Effects of Iron Oxide Nanoparticles (γ-Fe2O3) on Liver, Lung and Brain Proteomes following Sub-Acute Intranasal Exposure: A New Toxicological Assessment in Rat Model Using iTRAQ-Based Quantitative Proteomics.

Iron Oxide Nanoparticles (IONPs) present unique properties making them one of the most used NPs in the biomedical field. Nevertheless, for many years, growing production and use of IONPs are associated with risks that can affect human and the environment. Thus, it is essential to study the effects of these nanoparticles to better understand their mechanism of action and the molecular perturbations induced in the organism. In the present study, we investigated the toxicological effects of IONPs (γ-Fe2O3) on liver, lung and brain proteomes in Wistar rats. Exposed rats received IONP solution during 7 consecutive days by intranasal instillation at a dose of 10 mg/kg body weight. An iTRAQ-based quantitative proteomics was used to study proteomic variations at the level of the three organs. Using this proteomic approach, we identified 1565; 1135 and 1161 proteins respectively in the brain, liver and lung. Amon them, we quantified 1541; 1125 and 1128 proteins respectively in the brain, liver and lung. Several proteins were dysregulated comparing treated samples to controls, particularly, proteins involved in cytoskeleton remodeling, cellular metabolism, immune system stimulation, inflammation process, response to oxidative stress, angiogenesis, and neurodegenerative diseases.

Nanoparticles in foods? A multiscale physiopathological investigation of iron oxide nanoparticle effects on rats after an acute oral exposure: Trace element biodistribution and cognitive capacities.

Iron Oxide Nanoparticles (IONPs) are used in several fields of application, mainly in the biomedical field for their magnetic properties and in food additive known as "E172" for their colour. In the present investigation, we focused on IONP effects on Wistar rat following acute oral exposure. We performed a multiscale physiopathological investigation in order to elucidate potential toxic effects linked to IONP ingestion, especially on cognitive capacities, trace element distribution, blood constituents, organ functions, organ structure and iron deposit. We demonstrated that oral exposure to IONPs induces disturbances of certain parameters depending on the dose. Interestingly, the histopathological examination evidenced inflammatory effects of IONPs in the liver with iron deposits in hepatocytes and Kuppfer cells. Neurobehavioral examination showed that oral exposure to IONPs did not affect nor rat emotions, exploration and locomotion capacities, nor spatial reference memory status. Furthermore, oral administration of IONPs did not disrupt the trace element homeostasis nor in the liver neither in the stomach. Altogether, our study evidenced low signs of toxicity, but some effects lead us to a careful use of these NPs. Thereby, their use in foods should be further studied to better evaluate the potential toxic risks of the oral exposure to IONPs.

Sub-acute intravenous exposure to Fe2O3 nanoparticles does not alter cognitive performances and catecholamine levels, but slightly disrupts plasma iron level and brain iron content in rats.

Engineered nanomaterials are used in various applications due to their particular properties. Among them, Iron Oxide Nanoparticles (Fe2O3-NPs) are used in Biomedicine as theranostic agents i.e. contrast agents in Magnetic Resonance Imaging and cancer treatment. With the increasing production and use of these Fe2O3-NPs, there is an evident raise of Fe2O3-NPs exposure and subsequently a higher risk of adverse outcomes for the environment and Human. In the present paper, we investigated the effects of an intravenous daily Fe2O3-NPs exposure on Wistar rat for one week. As results, we showed that several hematological parameters and transaminase (ALT and AST) levels as well as organ histology remained unchanged in treated rats. Neither the catecholamine levels nor the emotional behavior and learning / memory capacities of rats were impacted by the sub-acute intravenous exposure to Fe2O3-NPs. However, iron level in plasma and iron content homeostasis in brain were disrupted after this exposure. Thus, our results demonstrated that Fe2O3-NPs could have transient effects on rat but the intravenous route is still safer that others which is encouraging for their use in medical and/or biological applications.

Intranasal instillation of iron oxide nanoparticles induces inflammation and perturbation of trace elements and neurotransmitters, but not behavioral impairment in rats.

Over the last decades, engineered nanomaterials have been widely used in various applications due to their interesting properties. Among them, iron oxide nanoparticles (IONPs) are used as theranostic agents for cancer, and also as contrast agents in magnetic resonance imaging. With the increasing production and use of these IONPs, there is an evident raise of IONP exposure and subsequently a higher risk of adverse outcome for humans and the environment. In this work, we aimed to investigate the effects of sub-acute IONP exposure on Wistar rat, particularly (i) on the emotional and learning/memory behavior, (ii) on the hematological and biochemical parameters, (iii) on the neurotransmitter content, and (vi) on the trace element homeostasis. Rats were treated during seven consecutive days by intranasal instillations at a dose of 10 mg/kg body weight. The mean body weight increased significantly in IONP-exposed rats. Moreover, several hematological parameters were normal in treated rats except the platelet count which was increased. The biochemical study revealed that phosphatase alkaline level decreased in IONP-exposed rats, but no changes were observed for the other hepatic enzymes (ALT and AST) levels. The trace element homeostasis was slightly modulated by IONP exposure. Sub-acute intranasal exposure to IONPs increased dopamine and norepinephrine levels in rat brain; however, it did not affect the emotional behavior, the anxiety index, and the learning/memory capacities of rats.