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.

Prenatal Stress Impairs Postnatal Learning and Memory Development via Disturbance of the cGMP-PKG Pathway and Oxidative Phosphorylation in the Hippocampus of Rats

Clinical and animal studies have found that prenatal stress can lead to pathological changes in embryos and fetuses. However, the mechanisms through which this occurs have not been made clear. In the present study, pregnant rats were subjected to chronic psychological stress during gestational days using an improved communication box system, and the changes in behavioral performance and proteins in the hippocampus of offspring were analyzed. It was found that prenatal stress caused postnatal growth retardation and impairment in spatial learning and memory. Furthermore, in isobaric tags for relative and absolute quantitation-based proteomics analyses, 158 significantly differentially expressed proteins (DEPs) were found between the two groups. Further analyses showed that these DEPs are involved in different molecular function categories and participate in several biological processes, such as energy metabolism, learning or memory, and synaptic plasticity. Moreover, the enrichment of pathways showed that the learning and memory impairment was primarily connected with the cyclic guanosine monophosphate–protein kinase G (cGMP–PKG) pathway and oxidative phosphorylation. At the same time, the cGMP level and the expression of PKG protein were significantly decreased, and the neuronal mitochondria appeared to have a swollen and irregular shape in the hippocampus of offspring of stressed rats. These results suggest that the chronic psychological stress that pregnant rats were subjected to during gestational days may have impaired the spatial learning and memory of offspring. This affected the hippocampal oxidative phosphorylation and inhibited the cGMP–PKG pathway.

Protective effect of methylene blue against copper oxide nanoparticle-induced neurobehavioral toxicity

Increasing attention has been paid in the past decade to assessing the toxicological effects of nanoparticles and finding a protectant; thus, the current study aimed to investigate the protective effect of the mitochondria-targeting drug methylene blue (MB) against copper oxide nanoparticle (CuO-NP)-induced neurobehavioral toxicity in rats. For this purpose, twenty rats were allocated to four equal groups (n = 5). The negative control group received distilled water intraperitoneally (IP) and Tween 80 (10 %) orally. The CuO-NP group was given a dose of 100 mg/kg of CuO-NPs, administered orally, and the positive control group was treated with 1 mg/kg MB intraperitoneally (IP). The final group was concurrently exposed to CuO-NPs and MB for 14 consecutive days. At the end of the study, each group was neurobehaviorally blind tested relative to other experimental animals, then brain tissue markers were determined and a histopathological examination was conducted. The results showed that supplementation with CuO-NPs induced neurobehavioral alterations; increased Cu content in the brain; and enhanced lipid peroxidation (malondialdehyde [MDA]), protein peroxidation (protein carbonyl [PC]), and DNA oxidative damage (8-hydroxy-2-deoxyguanosine [8-OH-dG]) compared to other treatments. In addition, a decrease was noted in the mitochondrial dehydrogenases' (aldehyde dehydrogenase 2 [ALDH2], and glutamate dehydrogenase [GDH]) activity in Cu-exposed rats. The histopathological findings revealed shrunken, pyknotic, and hypereosinophic cortical neurons and increased immune positive brown staining of caspase-3 protein, indicating apoptosis. Co-treatment with methylene blue ameliorated the neurotoxic effects of CuO-NPs; therefore, MB evidently had a powerful modulatory effect against the neurotoxicity of nano-Cu oxide via its antioxidant and mitochondrial protection properties.

Organ distribution and biological compatibility of surface-functionalized reduced graphene oxide

Graphene is an sp² hybridized allotrope of carbon with a honeycomb lattice structure that has many applications in biomedicine owing to its unique physico-chemical properties. Graphene has attracted much interest from scientists for its biomedical potential, including in drug/gene delivery, fluorescent labeling of target analytes, tissue engineering, regenerative medicine and MRI contrast enhancement. However, there are very limited data available concerning the toxicity of graphene, and efforts have been made to study the bio-nano interactions of Pluronic functionalized reduced graphene oxide (rGO-P) in animal models. The present study aimed to evaluate the systemic toxicity of rGO-P and its ability to cross the blood-brain barrier in Swiss Albino mice subject to acute exposure to 10 mg kg^-1 body weight of rGO-P. Prolonged exposure was evaluated in female Wistar rats by analyzing feto-placental transmission and any associated developmental neurotoxicity after intravenous administration of 5 mg kg^-1 and 10 mg kg^-1 body weight of rGO-P. Biodistribution analysis using confocal Raman mapping indicated that tiny amounts of rGO-P accumulated in major organs of both dams and pups, with no evident toxic response. The accumulation of rGO-P in various tissues of rat pups born to treated dams is ample evidence of feto-placental transmission. The present study clearly suggests that rGO-P is not toxic under any of the experimental conditions. These findings can therefore be carried forward for application of rGO-P in drug/gene delivery, early diagnosis and treatment of various diseases in neonates and adults. The results of the study show that rGO-P is an auspicious and promising material for future healthcare applications.

Measuring Preweaning Sensorial and Motor Development in the Mouse

The immaturity at birth and the slowness of ontogenic processes in mice provide the opportunity to measure rates of development. We describe here 18 measures covering the sensorial and motor onset from birth to weaning. The measures are non-invasive, making a follow-up strategy possible. The first basic protocol indicates how to produce mice with known conceptional or chronological age, as the control of the age is a prerequisite to compare rates of development in groups of mice. The second basic protocol describes a set of methods for identifying the pups during a follow-up study. A third basic protocol describes testing newborn mice for the appearance of sensorial and motor abilities in a follow-up design. Taken together, the three protocols make possible the validation of potential murine models of interest for understanding human developmental disorders. © 2018 by John Wiley & Sons, Inc.

Engineered nanomaterial applications in perinatal therapeutics

Engineered nanomaterials (ENM) are widely used in commercial, domestic, and more recently biomedical applications. While the majority of exposures to ENM are unintentional, biomedical platforms are being evaluated for use in individualized and/or tissue-targeted therapies. Treatments are often avoided during prenatal periods to reduce adverse effects on the developing fetus. The placenta is central to maternal-fetal medicine. Perturbation of placental functions can limit transfer of necessary nutrients, alter production of hormones needed during pregnancy, or allow undesired passage of xenobiotics to the developing fetus. The development of therapeutics to target specific maternal, placental, or fetal tissues would be especially important to reduce or circumvent toxicities. Therefore, this review will discuss the potential use of ENM in perinatal medicine, the applicable physiochemical properties of ENM in therapeutic use, and current methodologies of ENM testing in perinatal medicine, and identify maternal, fetal, and offspring concerns associated with ENM exposure during gestation. As potential nanoparticle-based therapies continue to develop, so does the need for thorough consideration and evaluation for use in perinatal medicine.

Oral application of carbon nanofibers in rats increases blood concentration of IL6 and IL10 and decreases locomotor activity

Carbon nanofibers (CNF) are versatile nanomaterials that are widely used in various fields of science and technology. As a consequence, animals as well as humans may be exposed to such compounds via different routes. We hypothesized that oral intake of CNF will lead to an inflammatory reaction and consequently induce behavioral impairments. To address this issue, rats were fed with 500mg/kgCNF for 14days and their locomotor activity, emotional status and cognition were quantified by testing the animals in an open field set-up, elevated plus maze and in the universal problem solving box which provides information about motivation and cognition. The behavioral tests were performed 3 times within 10days. At the end of the experiment, blood samples were collected and the plasma concentrations of IL-6, IL-8, IL-1β, IL-10 and IL-18 were measured. Our results demonstrated an inflammatory reaction determined by a significantly elevated IL-6 concentration. This, however, was counteracted by an even more pronounced increase in IL-10. The behavioral effects were restricted mainly to a decrease in locomotor activity which was significant in the open field test, as well as the elevated plus maze. Other parameters indicative of cognitive performance were not influenced and also the emotional status was largely unaffected. In conclusion, our results revealed that oral intake of 500mg/kgCNF induced some adverse effects, which, however, can be still partially compensated by the organism.

Influence of multi-walled carbon nanotubes on the cognitive abilities of Wistar rats

Studies of the neurobehavioral effects of carbon nanomaterials, particularly those of multi-walled carbon nanotubes (MWCNTs), have concentrated on cognitive effects, but data are scarce. The aim of this study was to assess the influence of MWCNTs on a number of higher nervous system functions of Wistar rats. For a period of 10 days, two experimental groups were fed with MWCNTs of different diameters (MWCNT-1 group, 8-10 nm; MWCNT-2 group, 18-20 nm) once a day at a dosage of 500 mg/kg. In the open-field test, reductions of integral indications of researching activity were observed for the two MWCNT-treated groups, with a parallel significant (P<0.01) increase in stress levels for these groups compared with the untreated control group. In the elevated plus-maze test, integral indices of researching activity in the MWCNT-1 and MWCNT-2 groups reduced by day 10 by 51 and 62%, respectively, while rat stress levels remained relatively unchanged. In the universal problem solving box test, reductions in motivation and energy indices of researching activity were observed in the two experimental groups. Searching activity in the MWCNT-1 group by day 3 was reduced by 50% (P<0.01) and in the MWCNT-2 group the relevant reduction reached 11.2%. By day 10, the reduction compared with controls, was 64% (P<0.01) and 58% (P<0.01) for the MWCNT-1 and MWCNT-2 groups, respectively. In conclusion, a series of specific tests demonstrated that MWCNT-treated rats experienced a significant reduction of some of their cognitive abilities, a disturbing and worrying finding, taking into consideration the continuing and accelerating use of carbon nanotubes in medicine and science.