Chromium oxide nanoparticle-induced biochemical and histopathological alterations in the kidneys and brain of Wistar rats

An Update Overview on Mechanistic Data and Biomarker Levels in Cobalt and Chromium-Induced Neurodegenerative Diseases

There is increasing evidence that the imbalance of metals as cobalt (Co) and chromium (Cr) may increase the risk of development and progression of neurodegenerative diseases (NDDs). The human exposure to Co and Cr is derived mostly from industry, orthopedic implants, and polluted environments. Neurological effects of Co and Cr include memory deficit, olfactory dysfunction, spatial disorientation, motor neuron disease, and brain cancer. Mechanisms of Co and Cr neurotoxicity included DNA damage and genomic instability, epigenetic changes, mitochondrial disturbance, lipid peroxidation, oxidative stress, inflammation, and apoptosis. This paper seeks to overview the Co and Cr sources, the mechanisms by which these metals induce NDDs, and their levels in fluids of the general population and patients affected by NDDs. To this end, evidence of Co and Cr unbalance in the human body, mechanistic data, and neurological symptoms were collected using in vivo mammalian studies and human samples.

Exploring the biocompatibility and healing activity of actinobacterial-enhanced reduced nano-graphene oxide in in vitro and in vivo model and induce bone regeneration through modulation of OPG/RANKL/RUNX2/ALP pathways

BACKGROUND

The development of cost-effective, simple, environment-friendly biographene is an area of interest. To accomplish environmentally safe, benign culturing that has advantages over other methods to reduce the graphene oxide (GO), extracellular metabolites from actinobacteria associated with mushrooms were used for the first time.

METHODS

Bactericidal effect of GO against methicillin-resistant Staphylococcus aureus, antioxidant activity, and hydroxyapatite-like bone layer formation, gene expression analysis and appropriate biodegradation of the microbe-mediated synthesis of graphene was studied.

RESULTS

Isolated extracellular contents Streptomyces achromogenes sub sp rubradiris reduced nano-GO to graphene (rGO), which was further examined by spectrometry and suggested an efficient conversion and significant reduction in the intensity of all oxygen-containing moieties and shifted crystalline peaks. Electron microscopic results also suggested the reduction of GO layer. In addition, absence of significant toxicity in MG-63 cell line, intentional free radical scavenging prowess, liver and kidney histopathology, and Wistar rat bone regeneration through modulation of OPG/RANKL/RUNX2/ALP pathways show the feasibility of the prepared nano GO.

CONCLUSIONS

The study demonstrates the successful synthesis of biographene from actinobacterial extracellular metabolites, its potential biomedical applications, and its promising role in addressing health and environmental concerns.

Toxic Kidney Damage in Rats Following Subchronic Intraperitoneal Exposure to Element Oxide Nanoparticles

Chronic diseases of the urogenital tract, such as bladder cancer, prostate cancer, reproductive disorders, and nephropathies, can develop under the effects of chemical hazards in the working environment. In this respect, nanosized particles generated as by-products in many industrial processes seem to be particularly dangerous to organs such as the testes and the kidneys. Nephrotoxicity of element oxide particles has been studied in animal experiments with repeated intraperitoneal injections of Al2O3, TiO2, SiO2, PbO, CdO, CuO, and SeO nanoparticles (NPs) in total doses ranging from 4.5 to 45 mg/kg body weight of rats. NPs were synthesized by laser ablation. After cessation of exposure, we measured kidney weight and analyzed selected biochemical parameters in blood and urine, characterizing the state of the excretory system. We also examined histological sections of kidneys and estimated proportions of different cells in imprint smears of this organ. All element oxide NPs under investigation demonstrated a nephrotoxic effect following subchronic exposure. Following the exposure to SeO and SiO2 NPs, we observed a decrease in serum creatinine and urea, respectively. Exposure to Al2O3 NPs caused an increase in urinary creatinine and urea, while changes in total protein were controversial, as it increased under the effect of Al2O3 NPs and was reduced after exposure to CuO NPs. Histomorphological changes in kidneys are associated with desquamation of the epithelium (following the exposure to all NPs except those of Al2O3 and SiO2) and loss of the brush border (following the exposure to all NPs, except those of Al2O3, TiO2, and SiO2). The cytomorphological evaluation showed greater destruction of proximal sections of renal tubules. Compared to the controls, we observed statistically significant alterations in 42.1% (8 of 19) of parameters following the exposure to PbO, CuO, and SeO NPs in 21.1% (4 of 19)-following that, to CdO and Al2O3 NPs-and in 15.8% (3 of 19) and 10.5% (2 of 19) of indicators, following the exposure to TiO2 and SiO2 nanoparticles, respectively. Histomorphological changes in kidneys are associated with desquamation of epithelium and loss of the brush border. The cytomorphological evaluation showed greater destruction of proximal sections of renal tubules. The severity of cyto- and histological structural changes in kidneys depends on the chemical nature of NPs. These alterations are not always consistent with biochemical ones, thus impeding early clinical diagnosis of renal damage. Unambiguous ranking of the NPs examined by the degree of their nephrotoxicity is difficult. Additional studies are necessary to establish key indicators of the nephrotoxic effect, which can facilitate early diagnosis of occupational and nonoccupational nephropathies.

Toxic and carcinogenic effects of hexavalent chromium in mammalian cells in vivo and in vitro: a recent update

Chromium VI (Cr (VI)) can cross cell membranes readily and causes the formation of Cr-DNA adducts, genomic damages, elevation of reactive oxygen species (ROS) and alteration of survival signaling pathways, as evidenced by the modulation in p53 signaling pathway. Mammals, including humans are exposed to Cr, including Cr (VI), frequently through inhalation, drinking water, and food. Several studies demonstrated that Cr (VI) induces cellular death through apoptosis and autophagy, genotoxicity, functional alteration of mitochondria, endocrine and reproductive impairments. In the present review, studies on deleterious effects of Cr (VI) exposure to mammalian cells (in vivo and in vitro) have been documented. Special attention is paid to the underlying molecular mechanism of Cr (VI) toxicity.

Therapeutic effects of CoenzymeQ10, Biochanin A and Phloretin against arsenic and chromium induced oxidative stress in mouse (Mus musculus) brain

Arsenic and chromium are the most common environmental toxicants prevailing in nature. Hence, the present study endeavors to investigate the salutary effects of Coenzyme Q10 (CoQ10), Biochanin A (BCA), and Phloretin (PHL) on the combined neurotoxic impact of arsenic and chromium in the Swiss albino mice (Mus musculus). Sodium meta-arsenite (100 ppm) and potassium dichromate (75 ppm) were given orally in conjugation with CoQ10 (10 mg/kg), BCA & PHL (50 mg/kg each) in accordance with body weight per day for the 2 weeks experimental duration. Weight reduction was figured out in the exposed toxic group of arsenic and chromium in contrast with the comparison group (control), and with the selected anti-oxidants treatment, it rose significantly to the basal status (p < 0.05). The concentration of arsenic and chromium was reduced significantly (p < 0.001) amidst all the natural compounds co-medicated groups. Anti-oxidant indicators, viz. lipid peroxidation (LPO) and protein carbonyl content (PCC), were found elevated, with reduction observed in the levels of superoxide dismutase (SOD), reduced glutathione (GSH), glutathione s-transferase (GST), and total thiols (TT) in the arsenic and chromium, co-exposed mice. The alterations in redox homeostasis were well corroborated with the estimations of cholinesterase's enzymes (p < 0.05) along with DNA fragmentation assay and altered Nrf2 signaling. The administration of CoQ10, BCA, and PHL ameliorated the effects of arsenic and chromium induced oxidative stress in the exposed mice. Our research unfolds the remedial outcome of these natural compounds contrary to the combined arsenic and chromium associated-neurotoxicity in the experimental model.

Lithium intoxication induced pyroptosis via ROS/NF-κB/NLRP3 inflammasome regulatory networks in kidney of mice

Humans and animals may be exposed to increasing contaminant lithium (Li) concentrations in the environment with the use and disposal of Li-containing products. Meanwhile, Li plays a key role in the treatment of human mental disorders, while the excessive accumulation of Li salts in the body can cause renal damage and nephrotic syndrome. In this study, the mechanism of renal inflammatory reaction induced by Li excessive intake was studied by establishing mice models in vitro and in vivo. The results of histopathology staining and TdT-mediated dUTP nick-end labeling assay showed that high Li condition (Lithium carbonate, 20 mg/kg/twice a day, i.e., for 30 consecutive days) caused inflammatory damage and apoptosis in kidney tissue cells. Western blot, qPCR, and immunohistochemical analysis were used to further study. In the vivo experiments, we found that Li reduced antioxidant enzyme capacity (glutathione peroxidase, total superoxide dismutase, total antioxidant capacity, and catalase) and induced the production of reactive oxygen species (ROS). Moreover, excessive Li activated nuclear factor kappa-B (NF-κB) signaling pathway and nucleotide-binding oligomerization domain-like receptors domains-containing protein 3 (NLRP3) inflammasome, resulting in activation of inflammatory factors tumor necrosis factor-α and IL-1β in the kidney of mice. In the vitro study, ROS as an upstream signal phosphorylated IκBα and NF-κB, up-regulated the NLRP3 inflammasome, increased caspase3, 6, 7, and 9 to exaggerate inflammation response, finally inducing pyroptosis in renal cells.

Current understanding of hexavalent chromium [Cr(VI)] neurotoxicity and new perspectives

Hexavalent chromium [Cr(VI)] is a global environmental pollutant that increases risk for several types of cancers and is increasingly being recognized as a neurotoxicant. Traditionally, the brain has been viewed as a largely post-mitotic organ due to its specialized composition of neurons, and consequently, clastogenic effects were not considered in neurotoxicology. Today, we understand the brain is composed of at least eight distinct cell types - most of which continue mitotic activity throughout lifespan. We have learned these dividing cells play essential roles in brain and body health. This review focuses on Cr(VI), a potent clastogen and known human carcinogen, as a potentially neurotoxic agent targeting mitotic cells of the brain. Despite its well-established role as a human carcinogen, Cr(VI) neurotoxicity studies have failed to find a significant link to brain cancers. In the few studies that did find a link, Cr(VI) was identified as a risk for gliomas. Instead, in the human brain, Cr(VI) appears to have more subtle deleterious effects that can impair childhood learning and attention development, olfactory function, social memory, and may contribute to motor neuron diseases. Studies of Cr(VI) neurotoxicity with animal and cell culture models have demonstrated elevated markers of oxidative damage and redox stress, with widespread neurodegeneration. One study showed mice exposed to Cr(VI)-laden tannery effluent exhibited longer periods of aggressive behavior toward an "intruder" mouse and took longer to recognize mice previously encountered, recapitulating the social memory deficits observed in humans. Here we conducted a critical review of the available literature on Cr(VI) neurotoxicity and synthesize the collective observations to thoroughly evaluate Cr(VI) neurotoxicity - much remains to be understood and recognized.

An Overview of the Beneficial Role of Antioxidants in the Treatment of Nanoparticle-Induced Toxicities

Nanoparticles (NPs) are used in many products and materials for humans such as electronics, in medicine for drug delivery, as biosensors, in biotechnology, and in agriculture, as ingredients in cosmetics and food supplements. Besides that, NPs may display potentially hazardous properties on human health and the environment as a consequence of their abundant use in life nowadays. Hence, there is increased interest of researchers to provide possible therapeutic agents or dietary supplements for the amelioration of NP-induced toxicity. This review summarizes the new findings in the research of the use of antioxidants as supplements for the prevention and alleviation of harmful effects caused by exposure of organisms to NPs. Also, mechanisms involved in the formation of NP-induced oxidative stress and protective mechanisms using different antioxidant substances have also been elaborated. This review also highlights the potential of naturally occurring antioxidants for the enhancement of the antioxidant defense systems in the prevention and mitigation of organism damage caused by NP-induced oxidative stress. Based on the presented results of the most recent studies, it may be concluded that the role of antioxidants in the prevention and treatment of nanoparticle-induced toxicity is unimpeachable. This is particularly important in terms of oxidative stress suppression.

An Overview of the Beneficial Role of Antioxidants in the Treatment of Nanoparticle-Induced Toxicities

Nanoparticles (NPs) are used in many products and materials for humans such as electronics, in medicine for drug delivery, as biosensors, in biotechnology, and in agriculture, as ingredients in cosmetics and food supplements. Besides that, NPs may display potentially hazardous properties on human health and the environment as a consequence of their abundant use in life nowadays. Hence, there is increased interest of researchers to provide possible therapeutic agents or dietary supplements for the amelioration of NP-induced toxicity. This review summarizes the new findings in the research of the use of antioxidants as supplements for the prevention and alleviation of harmful effects caused by exposure of organisms to NPs. Also, mechanisms involved in the formation of NP-induced oxidative stress and protective mechanisms using different antioxidant substances have also been elaborated. This review also highlights the potential of naturally occurring antioxidants for the enhancement of the antioxidant defense systems in the prevention and mitigation of organism damage caused by NP-induced oxidative stress. Based on the presented results of the most recent studies, it may be concluded that the role of antioxidants in the prevention and treatment of nanoparticle-induced toxicity is unimpeachable. This is particularly important in terms of oxidative stress suppression.

Assessment of DNA Methylation and Oxidative Changes in the Heart and Brain of Rats Receiving a High-Fat Diet Supplemented with Various Forms of Chromium

Simple Summary

Obesity is one of the most prevalent diseases of civilization in the 21st century. This may be due to an increase in the consumption of high-fat diets. For the treatment of obesity, various supplements with chromium (III) are used. Chromium has the ability to regulate carbohydrate and lipid metabolism, which may result in weight loss. Our studies compared the effects of a high-fat diet supplemented with three different forms of chromium-chromium (III) picolinate, chromium (III) -methionine, and nano-sized chromium on oxidative damage of the DNA, proteins, and lipids in the heart and brain of rats. The conducted study showed that the use of a high-fat diet results in oxidation of the DNA, proteins, and lipids in the brain and heart, and the addition of chromium additionally intensifies these processes, especially when used in the form of nanoparticles. Therefore, the results of these studies suggest that one should be careful when using chromium supplementation to counteract obesity, because it may be associated with the risk of deterioration of the functioning of the heart and brain.

Abstract

The aim of the study was to determine how feeding rats a high-fat diet supplemented with various forms of chromium affects DNA methylation and oxidation reactions as well as the histology of heart and brain tissue. The rats received standard diet or high-fat diet and chromium at 0.3 mg/kg body weight (BW) in form of chromium (III) picolinate, chromium (III)-methionine, or nano-sized chromium. The content of malondialdehyde (MDA), protein carbonyl (PC), and 8-hydroxydeoxyguanosine (8-OHDG), the level of global DNA methylation and the activity of selected DNA repair enzymes were determined in the blood. In the brain and heart, the content of MDA, PC, 8-OHDG, and levels of global DNA methylation were determined. The brain was subjected to histological examination. The use of a high-fat diet was found to intensify epigenetic changes and oxidation reactions in the heart and brain. It was concluded that epigenetic changes and oxidation of lipids, proteins, and DNA in the heart and brain of rats resulting from the use of a high-fat diet cannot be limited by supplementing the diet with chromium. It was established that the use of chromium to supplement a high-fat diet intensifies the negative epigenetic and oxidative changes in the heart and brain, especially in the case of chromium nanoparticles.

Nanotechnology-based Drug Delivery, Metabolism and Toxicity

BACKGROUND

Nanoparticles (NPs) are being used extensively owing to their increased surface area, targeted delivery and enhanced retention. NPs have the potential to be used in many disease conditions. Despite widespread use, their toxicity and clinical safety still remain a major concern.

OBJECTIVE

The purpose of this study was to explore the metabolism and toxicological effects of nanotherapeutics.

METHODS

Comprehensive, time-bound literature search was done covering the period from 2010 till date. The primary focus was on the metabolism of NP including their adsorption, degradation, clearance, and bio-persistence. This review also focuses on updated investigations on NPs with respect to their toxic effects on various in vitro and in vivo experimental models.

RESULTS

Nanotechnology is a thriving field of biomedical research and an efficient drug delivery system. Further their applications are under investigation for diagnosis of disease and as medical devices.

CONCLUSION

The toxicity of NPs is a major concern in the application of NPs as therapeutics. Studies addressing metabolism, side-effects and safety of NPs are desirable to gain maximum benefits of nanotherapeutics.

Comparative study of toxicological assessment of yttrium oxide nano- and microparticles in Wistar rats after 28 days of repeated oral administration

Despite their enormous advantages, nanoparticles (NPs) have elicited disquiet over their safety. Among the numerous NPs, yttrium oxide (Y2O3) NPs are utilised in many applications. However, knowledge about their toxicity is limited, and it is imperative to investigate their potential adverse effects. Therefore, this study explored the effect of 28 days of repeated oral exposure of Wistar rats to 30, 120 and 480 mg/kg body weight (bw) per day of Y2O3 NPs and microparticles (MPs). Before initiation of the study, characterisation of the particles by transmission electron microscopy, dynamic light scattering, Brunauer-Emmett-Teller and laser Doppler velocimetry was undertaken. Genotoxicity was evaluated using the comet and micronucleus (MN) assays. Biochemical markers aspartate transaminase, alanine transaminase, alkaline phosphatase, malondialdehyde, superoxide dismutase, reduced glutathione, catalase and lactate dehydrogenase in serum, liver and kidney were determined. Bioaccumulation of the particles was analysed by inductively coupled plasma optical emission spectrometry. The results of the comet and MN assays showed significant differences between the control and groups treated with 120 and 480 mg/kg bw/day Y2O3 NPs. Significant biochemical alterations were also observed at 120 and 480 mg/kg bw/day. Haematological and histopathological changes were documented. Yttrium (Y) biodistribution was detected in liver, kidney, blood, intestine, lungs, spleen, heart and brain in a dose- and the organ-dependent manner in both the particles. Further, the highest levels of Y were found in the liver and the lowest in the brain of the treated rats. More of the Y from NPs was excreted in the urine than in the faeces. Furthermore, NP-treated rats exhibited much higher absorption and tissue accumulation. These interpretations furnish rudimentary data of the apparent genotoxicity of NPs and MPs of Y2O3 as well as the biodistribution of Y. A no-observed adverse effect level of 30 mg/kg bw/day was found after oral exposure of rats to Y2O3 NPs.

Hepatotoxicity and chromosomal abnormalities evaluation due to single and repeated oral exposures of chromium oxide nanoparticles in Wistar rats

Metal oxide nanoparticles (NPs) have widespread uses ranging from nanoelectronics to nanotherapeutics. Because of their expanding industrial applications, a better understanding of their toxicity is needed. So far, limited reports are available on chromium oxide NPs (Cr2O3 NPs) toxicity. In this work, Cr2O3 NPs were synthesized and characterized in a sequential manner using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy. Dose- and time-dependent toxicity assessment of Cr2O3 NPs was carried out in Wistar rats by examining liver function biomarkers, tissue histopathology, micronuclei (MN) formation, and chromosomal aberrations (CAs) in bone marrow along with sperm abnormalities. The results of this study demonstrated typical XRD and FTIR patterns of Cr2O3 NPs with a size of approximately 23.47 nm. Animals exposed to Cr2O3 NPs, exhibited a significant increase in aspartate transaminase, alanine transaminase, alkaline phosphatase, gamma glutamyltransferase, and total bilirubin, signifying liver injury. Histopathology data also supported the marked alterations in the liver biochemistry of NPs-exposed animals. Further, an increase in the frequency of MN, CA, and sperm abnormalities suggested Cr2O3 NPs-mediated genotoxicity. It is, therefore, suggested that possible safety issues of Cr2O3 NPs should be addressed promptly with limited future use in occupational settings.

Response of the antioxidant enzymes of rats following oral administration of metal-oxide nanoparticles (Al2O3, CuO, TiO2)

Metal-oxide nanoparticles (NPs), as a new emerging technological compound, promise a wide range of usage areas and consequently have the potential to cause environmental toxicology. In the present work, aluminum (Al₂O₃), copper (CuO), and titanium (TiO₂) nanoparticles (NPs) were administered via oral gavage to mature female rats (Rattus norvegicus var. albinos) for 14 days with a dose series of 0 (control), 0.5, 5, and 50 (mg/kg b.w./day). Enzyme activities of the antioxidant system such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), and glutathione reductase (GR) in the liver were measured. Transmission electron microscope (TEM) images of the liver were taken to demonstrate NP accumulation and distribution in liver tissue. Data showed that all NPs caused some significant (P > 0.05) alterations in the activities of antioxidant enzymes. CAT activity increased after CuO and TiO₂ administrations, while SOD activity decreased after Al₂O₃ administration. The activities of enzymes associated with glutathione (GR, GPx, GST) metabolisms were also significantly altered by NPs. GPx activity increased in rats received Al₂O₃, CuO NPs, while GR activity increased only by Al₂O₃. However, there were increases (TiO₂) and decreases (CuO) in GST activity in the liver of rats. TEM images of the liver demonstrated that all NPs accumulated in the liver, even at the lowest dose. This study indicated that the antioxidant enzymes in the liver of rats were affected by all NPs, suggesting the antioxidant system of rats suffered after NP administration.