Effects Of Cerium Oxide Nanoparticles Research Articles

Protective Effects of Cerium Oxide Nanoparticles on Oxaliplatin induced Neurotoxicity in Adult Male Albino Rats

Background: Oxaliplatin is a chemotherapeutic agent used for treatment of colorectal cancer. Peripheral neuropathy is a dose limiting toxicity which may persist even after its termination. Oxidative stress may be a direct cause of this neurotoxicity. Cerium oxide nanoparticles (CONPs) are promising antioxidants for applications in medicine as they are well tolerated in biological models. Aim: The present work was designed to study the protective effect of CONPs on neurotoxicity induced by oxaliplatin in adult male albino rats. Materials and methods: 120 rats were divided into 4 groups: Control group, CONPs group (60mg/kg, 5 times/week), Oxaliplatin group (4mg/kg, twice/week) and Oxaliplatin&CONPs group, for 8 weeks. After 4 & 8 weeks, 10 rats from each group were used to measure myelin protein zero (MPZ), malondialdhyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) in the left sciatic nerves. The right sciatic nerves and lumbar spinal cord were used for histopathological study. Results: Oxaliplatin decreased MPZ and induced demyelination and degeneration of sciatic nerve fibers. Also, it increased MDA levels. SOD and GPx activity were increased then decreased. GSH levels were decreased. In the lumbar spinal cord sections, abnormal morphology were seen. CONPs administration increased MPZ and returned normal morphology of sciatic nerve fibers. They decreased MDA levels. SOD was increased after 8 weeks, GPx and GSH not changed. In the lumbar spinal cord sections normal morphology were seen with some hydropic degeneration. Conclusion Oxaliplatin treatment induced hypomyelination in sciatic nerves. CONPs have neuroprotective effect.

Protection effect of cerium oxide nanoparticles against radiation-induced acute lung injuries in rats

Radiation therapy is one of the most common tools for treating cancer. The aim is to deliver adequate doses of radiation to kill cancer cells and the most challenging part during this procedure is to protect normal cells from radiation. One strategy is to use a radioprotector to spare normal tissues from ionizing radiation effects. Researchers have pursued cerium oxide nanoparticles as a therapeutic agent, due to its diverse characteristics, which include antioxidant properties, making it a potential radioprotector. One hundred rats were divided into five groups of A) control group, intraperitoneal (IP) saline injection was done twice a week; B) bi-weekly IP injection of 14.5nM (0.00001mg/kg) CNP for two weeks; C) a single whole thorax radiation dose of 18Gy; D) a single whole thorax radiation dose of 18Gy+bi-weekly injection of 14.5nM CNP for two weeks after radiation; E) bi-weekly IP injection of 14.5nM CNP for two weeks prior to radiation+a single whole thorax radiation dose of 18Gy. Thirty days after irradiation, 7 rats from each group were anesthetized and their lungs extracted for histopathological examination. Statistical analyses revealed that CNP significantly decreased the incidence of tissue collapse and neutrophile aggregation in rats receiving CNP before radiation in comparison with the radiation group. The results suggested the possibility of using CNP as a future radioprotector due to its ability to protect normal cells against radiation-induced damage.

Protective effects of nanoceria in imiquimod induced psoriasis by inhibiting the inflammatory responses.

Aim: To investigate the effect of cerium oxide nanoparticles (nanoceria) on psoriasis. Materials & methods: Fourier transform infrared, powder x-ray diffraction and scanning electron microscopy were used to characterize nanoceria. Imiquimod (62.5mg/mice) was used for the induction of psoriasis while nanoceria was administered/applied via multiple routes (topical gel, intraperitoneal and subcutaneous) as a therapeutic intervention once daily. Results: Nanoceria significantly attenuated splenic hypertrophy, psoriasis area severity index scoring, and lipid peroxidation. It also reduced the expression of various inflammatory and proliferation markers such as IL-17, IL-22, IL-23, Ki-67, NF-κB, COX-2 and GSK3. Conclusion: Nanoceria exerts an antipsoriatic effect by inhibiting major pathogenic immune axes namely the Th-cell mediated IL-17/IL-23 axis and by downregulating other crucial inflammatory proteins like NF-κB, COX-2 and GSK3.

Cerium oxide nanoparticles improve liver regeneration after acetaminophen-induced liver injury and partial hepatectomy in rats

Background and aimsCerium oxide nanoparticles are effective scavengers of reactive oxygen species and have been proposed as a treatment for oxidative stress-related diseases. Consequently, we aimed to investigate the effect of these nanoparticles on hepatic regeneration after liver injury by partial hepatectomy and acetaminophen overdose.MethodsAll the in vitro experiments were performed in HepG2 cells. For the acetaminophen and partial hepatectomy experimental models, male Wistar rats were divided into three groups: (1) nanoparticles group, which received 0.1 mg/kg cerium nanoparticles i.v. twice a week for 2 weeks before 1 g/kg acetaminophen treatment, (2) N-acetyl-cysteine group, which received 300 mg/kg of N-acetyl-cysteine i.p. 1 h after APAP treatment and (3) partial hepatectomy group, which received the same nanoparticles treatment before partial hepatectomy. Each group was matched with vehicle-controlled rats.ResultsIn the partial hepatectomy model, rats treated with cerium oxide nanoparticles showed a significant increase in liver regeneration, compared with control rats. In the acetaminophen experimental model, nanoparticles and N-acetyl-cysteine treatments decreased early liver damage in hepatic tissue. However, only the effect of cerium oxide nanoparticles was associated with a significant increment in hepatocellular proliferation. This treatment also reduced stress markers and increased cell cycle progression in hepatocytes and the activation of the transcription factor NF-κB in vitro and in vivo.ConclusionsOur results demonstrate that the nanomaterial cerium oxide, besides their known antioxidant capacities, can enhance hepatocellular proliferation in experimental models of liver regeneration and drug-induced hepatotoxicity.

Antioxidant Enzyme-Mimetic Activity and Neuroprotective Effects of Cerium Oxide Nanoparticles Stabilized with Various Ratios of Citric Acid and EDTA.

Cerium oxide (CeO2) nanoparticles (CeNPs) are potent antioxidants that are being explored as potential therapies for diseases in which oxidative stress plays an important pathological role. However, both beneficial and toxic effects of CeNPs have been reported, and the method of synthesis as well as physico-chemical, biological, and environmental factors can impact the ultimate biological effects of CeNPs. In the present study, we explored the effect of different ratios of citric acid (CA) and EDTA (CA/EDTA), which are used as stabilizers during synthesis of CeNPs, on the antioxidant enzyme-mimetic and biological activity of the CeNPs. We separated the CeNPs into supernatant and pellet fractions and used commercially available enzymatic assays to measure the catalase-, superoxide dismutase (SOD)-, and oxidase-mimetic activity of each fraction. We tested the effects of these CeNPs in a mouse hippocampal brain slice model of ischemia to induce oxidative stress where the fluorescence indicator SYTOX green was used to assess cell death. Our results demonstrate that CeNPs stabilized with various ratios of CA/EDTA display different enzyme-mimetic activities. CeNPs with intermediate CA/EDTA stabilization ratios demonstrated greater neuroprotection in ischemic mouse brain slices, and the neuroprotective activity resides in the pellet fraction of the CeNPs. The neuroprotective effects of CeNPs stabilized with equal proportions of CA/EDTA (50/50) were also demonstrated in two other models of ischemia/reperfusion in mice and rats. Thus, CeNPs merit further development as a neuroprotective therapy for use in diseases associated with oxidative stress in the nervous system.

Cerium Oxide Nanoparticles Affect Heavy Metals Uptake by Pea in a Divergent Way than Their Ionic and Bulk Counterparts

The impact of cerium oxide nanoparticles, bulk cerium oxide and ionic cerium nitrate on the plant development as well as the uptake and further translocation of Cu, Mn, Zn and Fe by sugar pea (Pisum sativum L.) was investigated. Plants were cultivated in the laboratory pot experiments using the modified Hoagland solutions supplemented with cerium compounds at the 200 mg L−1 Ce level. Analysis of variance proved that cerium oxide nanoparticles significantly decreased Cu, Mn, Zn and Fe concentrations in roots and above ground parts of the pea plants. The latter ions are presumably transported via symplastic pathways and may compete with nanoparticles for similar carriers. The lowest impact on the plant growth and the metal uptake was observed under the bulk CeO2 treatment. On the contrary, strongest interactions were observed for supplementation with ionic cerium nitrate. The highly beneficial effect of cerium oxide nanoparticles on the plant growth was not supported by this study. The latter conclusion is of particular relevance when environmental impact of cerium compounds on the waste management, municipal urban low emissions and food production is to be concerned.

The Role of Wound Healing and Protective Effect of Cerium Oxide Nanoparticles

While it is true that the humans are endangered by many dangers and may endure many pains, but the fact remains that some risks are inescapable. For one thing, the skin is the first defensive wall of the body against external hazards.

Impact of nanoparticle surface charge and phosphate on the uptake of coexisting cerium oxide nanoparticles and cadmium by soybean (Glycine max. (L.) merr.)

Engineered nanoparticles (ENPs) often interact closely with coexisting environmental pollutants; however, the effect of their surface properties on such interactions in a plant system has not been examined. This study investigated the roles of ENP surface charge and growth media chemistry on the mutual effects of cerium oxide nanoparticles (CeO2NPs) and cadmium (Cd) on their plant uptake and accumulation in a hydroponic system. Soybean seedlings were exposed to five nanoparticle/Cd treatments including: 100 mg L−1 CeO2NPs(+); 100 mg L−1 CeO2NPs(−); 100 mg L−1 CeO2NPs(+) + 1 mg L−1 Cd; 100 mg L−1 CeO2NPs(−) + 1 mg L−1 Cd; and 1 mg L−1 Cd only, in the presence or absence of 15 mg L−1 phosphorous in the form of phosphate. After 4 days of exposure, concentrations of Cd and Ce in plant tissues were quantified by inductively coupled plasma-mass spectrometry. Roots exposed to CeO2NPs(+) contained 87% higher Ce than plants exposed to CeO2NPs(−). Phosphate significantly increased the root concentration of Ce by 61% and 66% exposed to CeO2NPs(+) and CeO2NPs(−), respectively. The mutual effect of CeO2NPs and Cd was also affected by phosphate, and the net effect of phosphate depended upon the surface charge of CeO2NPs.

Beyond the Scavenging of Reactive Oxygen Species (ROS): Direct Effect of Cerium Oxide Nanoparticles in Reducing Fatty Acids Content in an In Vitro Model of Hepatocellular Steatosis

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic accumulation of lipids. Antisteatotic effects of cerium oxide nanoparticles (CeO2NPs) have recently been shown in animal models of liver disease. However, it is unclear whether the activity of CeO2NPs is related solely to the decrease in oxidative stress or, in addition, they directly decrease liver fatty acid accumulation. To address this question, in this work, we used an in vitro model of hepatocellular steatosis, exposing HepG2 cells to oleic and palmitic acid. Cell uptake of CeO2NPs and their effect on oxidative stress and viability of hepatic cells cultured with H2O2 were also evaluated. Results show that CeO2NPs were uptaken by HepG2 cells and reduced oxidative stress and improved cell viability. Treatment with oleic and palmitic acid increased lipogenesis and the content of different fatty acids. CeO2NPs reduced palmitic and stearic acid and most fatty acids consisting of more than 18 carbon atoms. These effects were associated with significant changes in elongase and desaturase activity. In conclusion, CeO2NPs directly protected HepG2 cells from cell injury in oxidative stress conditions and reduced fatty acid content in steatotic conditions by inducing specific changes in fatty acid metabolism, thus showing potential in the treatment of NAFLD.

Functionalized cerium oxide nanoparticles mitigate the oxidative stress and pro-inflammatory activity associated to the portal vein endothelium of cirrhotic rats

Background and aimsThe occurrence of endothelial alterations in the liver and in the splanchnic vasculature of cirrhotic patients and experimental models of liver diseases has been demonstrated. However, the pathological role of the portal vein endothelium in this clinical context is scarcely studied and, therefore, deserves attention. In this context, we aimed to investigate whether pathological endothelial activation occurs in the portal vein of cirrhotic rats.MethodsCirrhosis was induced in wistar rats by CCl4 inhalation. We generated immortalized endothelial cells from the portal vein of control (CT-iPVEC) and cirrhotic rats (CH-iPVEC) by retroviral transduction of the SV40 T antigen. We assessed differential gene expression and intracellular reactive oxygen species (ROS) levels in iPVECs and in portal veins of control and cirrhotic rats. Finally, we assessed the therapeutic effectiveness of cerium oxide nanoparticles (CeO2NP) on reversing PVEC activation and macrophage polarization.ResultsCH-iPVECs overexpressed collagen-I, endothelin-1, TIMP-1, TIMP-2, IL-6 and PlGF genes. These results were consistent with the differential expression showed by whole portal veins from cirrhotic rats. In addition, CH-iPVECs showed a significant increase in intracellular ROS and the capacity of potentiating M1 polarization in macrophages. The treatment of CH-iPVECs with CeO2NPs blocked intracellular ROS formation and IL-6 and TIMP-2 gene overexpression. In agreement with the in vitro results, the chronic treatment of cirrhotic rats with CeO2NPs also resulted in the blockade of both ROS formation and IL-6 gene overexpression in whole portal veins.ConclusionsEndothelial cells from portal vein of cirrhotic rats depicted an abnormal phenotype characterized by a differential gene expression and the induction of M1 polarization in macrophages. We identified the excess of intracellular reactive oxygen species (ROS) as a major contributor to this altered phenotype. In addition, we demonstrated the utility of the nanomaterial cerium oxide as an effective antioxidant capable of reverse some of these pathological features associated with the portal vein in the cirrhosis condition.

Effects of cerium oxide nanoparticles on hemostasis: Coagulation, platelets, and vascular endothelial cells.

Cerium oxide nanoparticles (nanoceria [NC]) have attracted much attention in biomedicine due to their surface composition that confers interesting redox activities and regenerative properties. Studies have demonstrated that the application of NPs in biomedicine can influence components of hemostatic system, inducing blood clotting, alterations of blood cells, and endothelial cell functions. NC were tested in vitro to assess their hemocompatibility and anticoagulant, anti-inflammatory, and anti-senescence activity in human endothelial cells. Hemocompatibility has been evaluated in vitro looking at the impact of NC on coagulation times, fibrinogen, and platelet aggregation. The effect of NC on vascular endothelial cells were assayed by testing cell viability, antioxidant activity, anticoagulant (tissue factor [TF]-mRNA expression) and anti-inflammatory properties (VCAM-1 exposure, cytokine release), and senescence (telomere shortening). NC did not show significant effects on coagulation process, hemolysis, or platelet aggregation. In endothelial cells, NC did not affect cell viability, reduced oxidative stress, inhibited mRNA-TF expression, VCAM-1 expression, and cytokine release. Moreover, NC reduce telomere shortening, possibly counteracting premature senescence. The hemocompatibility combined with anticoagulant and anti-inflammatory phenotype and the ability of counteract the premature senescence in vascular cells make NC a promising therapeutic tool in oxidative stress-related conditions. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Effect of foliar application of cerium oxide nanoparticles on growth, photosynthetic pigments, electrolyte leakage, compatible osmolytes and antioxidant enzymes activities of Calendula officinalis L.

The nanoparticles influence on plants’ biological processes has not been clearly understood. Increase of nanoparticles in the environment during advent of industrial technologies can be a significant threat to ecosystems, and their interaction with plants is very important. The aim of this study was to investigate the effects of cerium oxide nanoparticles (CeO2 NPs) on biochemical and physiological parameters of marigold (Calendula officinalis L.). Seeds were planted and after 2 weeks, seedlings were treated with different concentrations of CeO2 NPs (50, 100, 200, 400, 800, 1600 and 3200 mg L−1) with foliar spray method. The hydrogen peroxide content and membrane electrolyte leakage were respectively increased after 100 and 200 mg L−1 CeO2 NPs treatment. Except for glutathione reductase (GR), the activities of antioxidant enzymes e.g. catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APOX), guaiacol peroxidase (GPOX), glutathione S-transferase (GST) and polyphenol oxidase (PPO) were induced by high concentrations of CeO2 NPs. Application of CeO2 NPs increased the contents of proline and soluble sugars after 200 mg L−1 and glycine betaine (GB) after 400 mg L−1. The growth parameters and chlorophyll contents were increased at low concentrations of CeO2 NPs (50 and 100 mg L−1) and decreased at higher ones. The results suggested that low concentrations of CeO2 NPs had a positive induction effect on C. officinalis but higher ones caused oxidative stress and toxicity responses. It seemed that induction of defense system including antioxidant enzymes activities and accumulation of osmolytes were not sufficient for reactive oxygen (ROS) detoxification.

Antiamyloid activity of functionalized cerium oxide nanoparticle on lysozyme fibrillation: Spectroscopic and microscopic investigation

Accumulation of amyloid fibrils of proteins in different organs is a pathological indication for various neurogenerative disorders. Recently nanotechnology is at the centre of interest to tackle with those disorders. In this study we have chosen hen egg white lysozyme as our model protein which is responsible for hereditary systemic Amyloidosis disease. Here we have reported effect of cerium oxide nanoparticle (CeONP), folic acid functionalized CeONP (FA-CeONP) and polyacrylic acid functionalized CeONP (PAA-CeONP) (all of them having size ∼18 nm) on fibrillation of hen egg white lysozyme (Lyz). The amyloid growth is monitored by Thioflavin T (ThT), Congo Red (CR), 8-anilinonapthalene-1-sulfonic acid (ANS) assay, time resolved fluorescence anisotropy, intrinsic fluorescence, circular dichroism, atomic force microscopy and fluorescence microscopy study. Results demonstrate that all nanoparticle (NP) shows antiamyloid activity by broadening lag phase and suppressing growth phase of Lyz amyloid growth, but PAA-CeONP shows maximum inhibitory effect. These bare and functionalized CeONP shows dose dependent antiamyloid activity. We have also demonstrated that such inhibition of amyloid formation is associated with reduction of β-sheet content of protein. The inhibition efficiency is quantified by half maximal inhibition concentration IC50 values. A mechanistic pathway is explained on the basis of electrostatic interaction between NP and Lyz by ζ- potential measurement. This interaction is also analyzed theoretically by docking analysis. Thus our study provides a basis for use of CeONP as a promising candidate in therapeutic application in amyloid related disorders.

Effects of cerium oxide nanoparticles on bacterial growth and behaviors: induction of biofilm formation and stress response.

In this paper, the effects of cerium oxide nanoparticles (CeO2 NPs) on the group bacterial behaviors were elaborated. After 36-h cultivation, the biofilm biomass was enhanced by the sub-lethal concentrations of 0.5 and 2mg/L CeO2 NP exposure. Meanwhile, the promoted production of total amino acids in microbes further resulted in the increased surface hydrophobicity and percentage aggregation. To resist the CeO2 NPs stress, the biofilm exhibited a double-layer microstructure, with the protein (PRO) and living cells occupying the bottom, the polysaccharide (PS), and dead cells dominating the top. The bacterial diversity was highly suppressed and Citrobacter and Pseudomonas from the phylum of γ-Proteobacteria strongly dominated the biofilm, indicating the selective and enriched effects of CeO2 NPs on resistant bacteria. The stimulated inherent resistance of biofilm was reflected by the reduced adenosine triphosphate (ATP) content after 4h exposure. The increased levels of reactive oxygen species (ROS) in the treatments of 8h CeO2 NP exposure led to the upregulated quorum sensing signals of acylated homoserine lactone (AHL) and autoinducer 2 (AI-2), beneficial to mitigating the environmental disturbance of CeO2 NPs. These results provide evidences for the accelerating effects of CeO2 NPs on biofilm formation through oxidative stress, which expand the understanding of the ecological effects of CeO2 NPs.

Effects of cerium oxide nanoparticles on biochemical and oxidative parameters in marigold leaves

The effects of suspensions of cerium oxide nanoparticles sprayed onto marigold seedlings (Calendula officinalis L.) at concentrations between 50 and 3200 mg L−1 were studied. At concentrations of 50 and 100 mg L−1, the nanoparticles had a slight positive effect on some growth parameters, but at higher concentrations they caused severe oxidative damage. Activities of phenylalanine ammonia lyase and lipoxygenase increased from 400 mg L−1 upward, tyrosine ammonia lyase from 1600 mg L−1. Ascorbate and glutathione contents decreased from 400 mg L−1 upwards.

Anti-apoptotic and Antioxidant Effect of Cerium Oxide Nanoparticles on Cyclophosphamide-Induced Hepatotoxicity

Anti-apoptotic and Antioxidant Effect of Cerium Oxide Nanoparticles on Cyclophosphamide-Induced Hepatotoxicity

Evaluation of anticancer effects of cerium oxide nanoparticles on mouse fibrosarcoma cell line.

Cerium oxide nanoparticles are associated with anticancer effects. While protecting normal cells, these nanoparticles exert their anticancer effects via oxidative stress and apoptosis in the cancer cells. In this study, the anticancer properties of nanoceria on fibrosarcoma cell line are evaluated. Cerium oxide nanoparticles were synthesized by the coprecipitation method and their anticancer effects on mouse fibrosarcoma tumor cells (WEHI164) were investigated. Viability assay was evaluated by MTT, and the DC-FDA assay performed for the detection of reactive oxygen species. For apoptosis assay, the annexin V/PI test was done as well as measuring the mRNA and protein expression levels of Bax and Bcl2 by real-time PCR and western blot method, respectively. Characterization of nanoceria reveals that synthesized nanoceria has cubic floruit structure with a size of about 30 nm. Toxicity assessment results show that nanoceria increases ROS levels and induced apoptosis in a dose-dependent manner in cancer cells (WEHI164), whereas low levels of toxicity were observed in normal cells (L929), even at the concentrations above 250 µg/ml in MTT assay. Real-time PCR and western blot assays showed that nanoceria could significantly increase the Bax expression in cancer cells. The results showed that nanoceria could act as a potential therapeutic agent for the treatment of fibrosarcoma.

Radiosensitizing Effect of Cerium Oxide Nanoparticles on Human Leukemia Cells.

Radiotherapy is an important protocol in the treatment of cancers, but radioresistance of cancerous cells is a challenge in cancer treatment. The aim of this study was to evaluate the radiosensitizing effect of Cerium oxide Nanoparticles (CNPs) on human promyelocytic leukemia cells (HL-60). HL-60 cells were treated with CNPs at different concentrations (10-100 μg/ml) and exposed to Ionizing Radiation (IR). The genotoxicity effects of CNPs or/and IR were assessed by micronuclei assay in HL-60 cells. It was found that CNPs increased the frequencies of micronuclei in HL-60 cells. CNPs pretreatment to irradiation significantly increased the IR-induced micronuclei incidences in HL-60 cells. The present study demonstrates CNPs to be an effective sensitizer on DNA damage induced by IR in HL-60 cells. These findings suggest the potential application of CNPs as a highly effective radiosensitizer for the treatment of leukemia.

Not Only Redox: The Multifaceted Activity of Cerium Oxide Nanoparticles in Cancer Prevention and Therapy.

Much information is accumulating on the effect of cerium oxide nanoparticles (CNPs) as cell-protective agents, reducing oxidative stress through their unique ability of scavenging noxious reactive oxygen species via an energy-free, auto-regenerative redox cycle, where superoxides and peroxides are sequentially reduced exploiting the double valence (Ce3+/Ce4+) on nanoparticle surface. In vitro and in vivo studies consistently report that CNPs are responsible for attenuating and preventing almost any oxidative damage and pathology. Particularly, CNPs were found to exert strong anticancer activities, helping correcting the aberrant homeostasis of cancer microenvironment, normalizing stroma-epithelial communication, contrasting angiogenesis, and strengthening the immune response, leading to reduction of tumor mass in vivo. Since these homeostatic alterations are of an oxidative nature, their relief is generally attributed to CNPs redox activity. Other studies however reported that CNPs exert selective cytotoxic activity against cancer cells and sensitize cancer cells to chemotherapy- and radiotherapy-induced apoptosis: such effects are hardly the result of antioxidant activity, suggesting that CNPs exert such important anticancer effects through additional, non-redox mechanisms. Indeed, using Sm-doped CNPs devoid of redox activity, we could recently demonstrate that the radio-sensitizing effect of CNPs on human keratinocytes is independent from the redox switch. Mechanisms involving particle dissolution with release of toxic Ce4+ atoms, or differential inhibition of the catalase vs. SOD-mimetic activity with accumulation of H2O2 have been proposed, explaining such intriguing findings only partially. Much effort is urgently required to address the unconventional mechanisms of the non-redox bioactivity of CNPs, which may provide unexpected medicinal tools against cancer.

Radioprotective Effect of Cerium Oxide Nanoparticles Against Genotoxicity Induced by Ionizing Radiation on Human Lymphocytes.

Ionizing radiation induces DNA damage on normal cell results in apoptosis and cell deaths. The radioprotective effects of cerium oxide nanoparticles (CNPs) on genotoxicity, apoptosis and necrosis induced by Ionizing Radiation (IR) in human healthy lymphocytes as highly radiosensitive cells were investigated. Lymphocytes were prepared from three volunteers and then treated with CNPs at different concentrations and exposed to IR at dose 1.5 Gy. The radioprotective effects of CNPs were assessed by micronucleus (MN) assay and flow cytometry. Interleukin-1 was quantified in treated samples. It was found that CNPs reduced the percentage of MN induced by IR in lymphocytes up to 73%. CNPs treatment significantly reduced IR-induced apoptotic and necrotic incidences in human lymphocytes. CNPs significantly reduced IL-1β produced in cell environment exposed to IR. The present study demonstrated that CNPs may be an effective radioprotector against DNA damage and apoptosis induced by IR mainly through mitigation of pro-inflammatory process in lymphocytes. This result provides a new potential indication of CNPs for protection of normal cells during radiation therapy in the treatment of cancer or unwanted radiation exposure.