Sub-chronic oral toxicity evaluation of herbo-metallic formulation Arshakuthar rasa in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Arshakuthar rasa (AR) is a mercury based Ayurvedic herbo-metallic formulation. The concerns are being raised about the probable toxicity of mercury after prolonged use of AR. Hence, there is need for a long-term repeated in vivo toxicity study. The study will provide data with scientific evidence to enable safe use of the drug. Moreover, lack of toxicity study with AR incited us to perform sub-chronic study on rats. AIM OF THE STUDY: The aim of the study is to generate data by performing a sub-chronic study to assess the toxicity of AR after its prolonged oral intake. MATERIALS AND METHODS: The female and male rats were administered with 30 (low), 300 (medium) and 600 mg/kg BW/day (high) dose of AR for 90 consecutive days. The body weight, feed consumption and water intake were monitored weekly. On 91st day, blood was collected from retro-orbital plexus of rats and then sacrificed to harvest the vital organs for biochemical, haematological, histopathological, genotoxicity along with the expression study of oxidative stress related genes and the biodistribution of elements in the blood. RESULTS: Significant alterations in serum biochemical parameters were observed at the medium and high doses. The histopathological changes were in corroboration with biochemical changes at high dose in liver. There was no detectable level of mercury in blood, less to moderate biochemical changes, no haematological changes, moderate regulation of stress-related genes, and low genotoxicity. These results indicated that AR can be considered as moderately toxic above 600 mg/kg BW and mildly toxic at 300 mg/kg BW. CONCLUSIONS: It may be interpreted that AR may not induce grave toxic response in human after long-duration of oral administration at therapeutic doses.

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.

1,2,3-Triazole Tagged 3H-Pyrano[2,3-d]pyrimidine-6-carboxylate Derivatives: Synthesis, in Vitro Cytotoxicity, Molecular Docking and DNA Interaction Studies.

A series of novel ethyl 2,7-dimethyl-4-oxo-3-[(1-phenyl-1H-1,2,3-triazol-4-yl)methyl]-4,5-dihydro-3H-pyrano[2,3-d]pyrimidine-6-carboxylate derivatives 7a - 7m were efficiently synthesized employing click chemistry approach and evaluated for in vitro cytotoxic activity against four tumor cell lines: A549 (human lung adenocarcinoma cell line), HepG2 (human hematoma), MCF-7 (human breast adenocarcinoma), and SKOV3 (human ovarian carcinoma cell line). Among the compounds tested, the compounds 7a, 7b, 7f, 7l, and 7m have shown potential and selective activity against human lung adenocarcinoma cell line (A549) with IC50 ranging from 0.69 to 6.74 µm. Molecular docking studies revealed that the compounds 7a, 7b, 7f, 7l, and 7m are potent inhibitors of human DNA topoisomerase-II and also showed compliance with stranded parameters of drug likeness. The calculated binding constants, kb , from UV/VIS absorptional binding studies of 7a and 7l with CT-DNA were 10.77 × 104 , 6.48 × 104 , respectively. Viscosity measurements revealed that the binding could be surface binding mainly due to groove binding. DNA cleavage study showed that 7a and 7l have the potential to cleave pBR322 plasmid DNA without any external agents.

Comparative study of cyto- and genotoxic potential with mechanistic insights of tungsten oxide nano- and microparticles in lung carcinoma cells.

The exigency of semiconductor and super capacitor tungsten oxide nanoparticles (WO3 NPs) is increasing in various sectors. However, limited information on their toxicity and biological interactions are available. Hence, we explored the underlying mechanisms of toxicity induced by WO3 NPs and their microparticles (MPs) using different concentrations (0-300 µg ml-1 ) in human lung carcinoma (A549) cells. The mean size of WO3 NPs and MPs by transmission electron microscopy was 53.84 nm and 3.88 µm, respectively. WO3 NPs induced reduction in cell viability, membrane damage and the degree of induction was size- and dose-dependent. There was a significant increase in the percentage tail DNA and micronuclei formation at 200 and 300 µg ml-1 after 24 hours of exposure. The DNA damage induced by WO3 NPs could be attributed to increased oxidative stress and inflammation through reactive oxygen species generation, which correlated with the depletion of reduced glutathione content, catalase and an increase in malondialdehyde levels. Cellular uptake studies unveiled that both the particles were attached/surrounded to the cell membrane according to their size. In addition, NP inhibited the progression of the cell cycle in the G2 /M phase. Other studies such as caspase-9 and -3 and Annexin-V-fluorescein isothiocyanate revealed that NPs induced intrinsic apoptotic cell death at 200 and 300 µg ml-1 concentrations. However, in comparison to NPs, WO3 MPs did not incite any toxic effects at the tested concentrations. Under these experimental conditions, the no-observed-significant-effect level of WO3 NPs was determined to be ≤200 µg ml-1 in A549 cells.

Assessment of genotoxicity and biodistribution of nano- and micron-sized yttrium oxide in rats after acute oral treatment.

The increasing use of yttrium oxide (Y2 O3 ) nanoparticles (NPs) entails an improved understanding of their potential impact on the environmental and human health. In the present study, the acute oral toxicity of Y2 O3 NPs and their microparticles (MPs) was carried out in female albino Wistar rats with 250, 500 and 1000 mg kg-1 body weight doses. Before the genotoxicity evaluation, characterization of the particles by transmission electron microscopy, dynamic light scattering and laser Doppler velocimetry was performed. The genotoxicity studies were conducted using micronucleus and comet assays. Results showed that Y2 O3 NP-induced significant DNA damage at higher dose (1000 mg kg-1 body weight) in peripheral blood leukocytes and liver cells, micronucleus formation in bone marrow and peripheral blood cells. The findings from biochemical assays depicted significant alterations in aspartate transaminase, alanine transaminase, alkaline phosphatase, malondialdehyde, superoxide dismutase, reduced glutathione, catalase and lactate dehydrogenase levels in serum, liver and kidneys at the higher dose only. Furthermore, tissue biodistribution of both particles was analyzed by inductively coupled plasma optical emission spectrometry. Bioaccumulation of yttrium (Y) in all tissues was significant and dose-, time- and organ-dependent. Moreover, Y2 O3 NP-treated rats exhibited higher tissue distribution along with greater clearance through urine whereas Y2 O3 MP-dosed animals depicted the maximum amount of Y in the feces. Hence, the results indicated that bioaccumulation of Y2 O3 NPs via its Y ions may induce genotoxic effects.

Toxicological assessment of nano and micron-sized tungsten oxide after 28days repeated oral administration to Wistar rats.

Tungsten oxide (WO3) nanoparticles (NPs) are being used in various applications. However, the health consequences of WO3 NPs exposure have not been explored extensively. Hence, the goal of this study was to evaluate the toxicity of WO3 NPs and their microparticles (MPs) after 28days repeated oral administration in Wistar rats. The particles were characterised by transmission electron microscopy (TEM), dynamic light scattering (DLS), laser Doppler velocimetry (LDV), Brunner-Emmett-Teller (BET), X- ray diffraction (XRD), and inductively coupled plasma optical emission spectrometer (ICP-OES). Genotoxicity was determined using comet assay in blood and liver and micronucleus test in bone marrow. Biochemical parameters such as aspartate aminotransferase and alanine aminotransferase in serum and reduced glutathione content, catalase and lipid peroxidation in liver tissue were determined. Histopathological changes in tissues were documented. Biodistribution of tungsten (W) in rat's blood, urine, feces and tissues were analysed. The mean size of WO3 NPs and MPs by TEM was 52±2.97nm, and 5.73±7.58µm and morphology were spherical in both the particles. DLS of NPs was 195.6nm. XRD and BET data of WO3 NPs and MPs showed a hexagonal and tetragonal crystal structure and surface area of 19.33 and 15.15(m2/g), respectively. The results revealed a significant increase in DNA damage and micronuclei, a difference in biochemical levels and histopathological alterations after exposure to 1000mg/kg dose of WO3 NPs. W biodistribution was detected in all the tissues in a dose and organ-dependent manner in both the particles. The highest amount of W was found in the liver and lowest in the brain of the treated rats. The tested NPs were found to have little toxicity hazard.

Toxicological assessment of tungsten oxide nanoparticles in rats after acute oral exposure.

Advances in and the rapid growth of the nanotechnology sector have escalated manufacture of nanoparticles (NPs), resulting in a significant increase in the probability of exposure of humans and wildlife to these materials. Many NPs have been found to exert genotoxicity. Therefore, genotoxicity studies are mandatory to assess the toxicity of NPs as a concern of succumbing to genetic diseases and cancers are universal. Tungsten oxide (WO3) NPs are being explored extensively in various fields. However, the toxicological data of WO3 NPs by oral route in mammals is limited. Hence, the goal of the current investigation was to evaluate the acute toxicity of WO3 NPs and microparticles (MPs) after single oral administration with 100, 500 and 1000 mg/kg body weight doses in female Wistar rats. TEM, dynamic light scattering and laser Doppler velocimetry techniques were used to characterise the particles. The genotoxicity studies were conducted using comet, micronucleus and chromosomal aberration assays. Alterations in biochemical indices and metal distribution in various organs were also evaluated. The mean size of WO3 NPs and MPs by TEM was 53.2 ± 1.91 nm and 5.17 ± 3.18 µm, respectively. The results revealed a significant increase in DNA damage and micronuclei and chromosomal aberrations after exposure to 1000 mg/kg dose of WO3 NPs. Significant alterations in aspartate transaminase, alanine transaminase, reduced glutathione, catalase and malondialdehyde levels in serum and liver were found only at the higher dose of WO3 NPs. Tungsten (W) biodistribution was observed in all the tissues in a dose-, time- and organ-dependent manner. In addition, the maximum concentration of W was found in the liver and the least in the brain was observed. The test substances were found to have a relatively low acute toxicity hazard. The data obtained gives preliminary information on the potential toxicity of WO3 NPs and MPs.

Genotoxicity study of nickel oxide nanoparticles in female Wistar rats after acute oral exposure.

Nanoparticles (NPs) apart from their widespread advantages and increased utilisation, have aroused concerns over their safe use. Nickel (II) oxides (NiO) NPs are used as catalysts, biosensors and in many of the consumer products. The increasing use of NiO NPs necessitates an improved understanding of their potential impact on the environment and human health. In this study, we investigated the acute genotoxic effects of NiO NPs by oral route administration with three different doses (125, 250 and 500 mg/kg bw). Before the in vivo toxicological evaluation, characterisation of particles by Transmission Electron Microscopy, X-ray diffraction, Dynamic Light Scattering (DLS) and Laser Doppler Velocimetry analysis was performed. Genotoxicity biomarkers such as comet, micronucleus and chromosomal aberrations (CAs) assays were utilised in this study. To document the uptake, retention and elimination of the NPs, biodistribution studies were also performed. The particle size obtained from Transmission Electron Microscopy analysis for NiO NPs was 15.62 ± 2.59 nm. The mean hydrodynamic diameter and PdI of NiO NPs in Milli-Q water suspension obtained by DLS was 168.9 ± 17.13 nm and 0.375, respectively. Comet assay revealed significant (P < 0.001) DNA damage at 500 mg/kg bw dose in the PBL, liver and kidney cells of rats at the 24-h sampling time. The result of micronucleus and CAs tests was in agreement with the comet assay data. Biodistribution of NiO NPs revealed a maximum accumulation of Ni in the liver tissue at the 24-h sampling time. Our study showed significant DNA damage at the high dose level and the effect was more prominent at 24-h sampling time, providing preliminary evidence that the NiO NPs are capable of inducing genotoxicity when administered through the oral route. However, mechanistic investigations are needed before drawing any firm conclusion regarding the toxicology of NiO NPs.

Assessment of genotoxicity in female agricultural workers exposed to pesticides.

OBJECTIVE: This study was designed to determine the genotoxic effect of exposure to a mixture of pesticides in 106 female agricultural workers employed in cotton fields from India. METHODS: Comet, micronucleus and chromosomal aberrations tests were carried out in peripheral blood lymphocytes. Micronucleus test was also performed in buccal epithelial cells. Levels of antioxidant enzymes, RBC acetylcholinesterase and hematological parameters were analyzed in the blood samples of the study subjects. RESULTS: The results indicated significant DNA damage, increased frequency of micronuclei and chromosomal aberrations in the exposed subjects (p < 0.05). The levels of antioxidant enzymes were significantly lowered and the rate of lipid peroxidation was elevated in the exposed subjects. CONCLUSION: The outcome of the study revealed an increased risk of genotoxicity and health implications in female agricultural workers.

Iodine catalyzed simple and efficient synthesis of antiproliferative 2-pyridones.

A simple and efficient method for the selective synthesis of 2-pyrdones from 4H-pyrans using iodine as catalyst and ethanol as solvent was developed. The present method is equally effective for both aromatic and hetero aromatic ring containing 4H-pyrans. The compatibility with various functional groups, mild reaction conditions, high yields and application of inexpensive, readily and easily available iodine as catalyst and formation of 2-pyridones as major products are the advantages of the present procedure. In vitro antiproliferative activity of the final synthesized compounds was evaluated with four different human cancer cell lines (Lung adenocarcinoma-A549, Hepatocarcinoma-HepG2, Breast carcinoma-MCF-7 and Ovarian carcinoma-SKOV3) and normal human lung fibroblast cell line (MRC-5). Compounds 2b showed better inhibition against MCF-7, HepG2 and A549 cell lines (IC50 8.00 ± 0.11, 11.93 ± 0.01 and 15.85 ± 0.04 µM, respectively) as compared with doxorubicin and also 2e showed moderate inhibition against MCF-7, HepG2 (IC50 9.32 ± 0.21 and 20.22 ± 0.01 µM, respectively, cell lines, respectively) as compared with doxorubicin. As many clinically used antiproliferative agents induce apoptosis in cancer cells hence, the 2-pyridone analogues were also tested for their ability to induce apoptosis in MCF-7 cells using the caspases-3 and -9 assays.

Synthesis and evaluation of anticancer and antiobesity activity of 1-ethoxy carbonyl-3,5-bis (3'-indolyl methylene)-4-pyperidone analogs.

A series of eleven novel bisindole derivatives were synthesized and screened for anticancer and antiobesity potentials in in vitro mode. The reaction of 1-ethoxy carbonyl 4-pyperidone 1a with indole-3-carboxaldehyde 1b in presence of catalytic amount of piperidine gave 2 which was N-alkylated with different benzyl halides in the presence of potassium carbonate to afford compounds 3a-3k in quantitative yields. Among the compounds tested for anticancer activity against different human cancer cell lines, 3f significantly inhibited HepG2 cell line (IC50 7.33 µM) when compared with standard doxorubicin (IC50 10.15 µM). Compounds 3e (IC50 2.75 µM), 3f (IC50 4.21 µM) and 3i (IC50 15.98 µM) showed better activity than the standard curcumin (IC50 23.54 µM) against A549 cell line. Also, among the synthesized compounds, 3g (IC50 14.89 µM), 3c (IC50 56.41 µM) and 3i (IC50 30.88 µM) have potentially inhibited enzyme lipase when compared to standard Orlistat (IC50 62.25 µM). In in silico docking assays, piperidones 3e, 3f, 3i, 3c and 3a showed higher binding affinity towards anti-cancer target of A549 (3e: -11.1, 3f: -10.3, 3c: -11.3, 3i: -11.2 kcal/mol), HepG2 (3f: -10.5 kcal/mol), HeLa (3d: -10.0 kcal/mol) and SKOV3 (3f: -8.4 kcal/mol) cell lines better than standard drug doxorubicin. Docking to lipase protein for compounds 3i, 3g and 3c showed scores of -11.1, -10.7 and -10.5 kcal/mol when compared to that of standard drug Orlistat with -6.9 kcal/mol.

Genotoxic effects of chromium oxide nanoparticles and microparticles in Wistar rats after 28 days of repeated oral exposure.

The nanotechnology industry has advanced rapidly in the last 10 years giving rise to the growth of the nanoparticles (NPs) with great potential in various arenas. However, the same properties that make NPs interesting raise concerns because their toxicity has not been explored. The in vivo toxicology of chromium oxide (Cr2O3)-NPs is not known till date. Therefore, this study investigated the 28-day repeated toxicity after 30, 300 and 1000 mg/kg body weight (bw)/day oral treatment with Cr2O3-NPs and Cr2O3 microparticles (MPs) in Wistar rats. The mean size of Cr2O3-NPs and Cr2O3-MPs was 34.89 ± 2.65 nm and 3.76 ± 3.41 µm, respectively. Genotoxicity was assessed using comet, micronucleus and chromosomal aberration (CA) assays. The results revealed a significant increase in DNA damage in peripheral blood leucocytes and liver, micronuclei and CA in bone marrow after exposure of 300 and 1000 mg/kg doses of Cr2O3-NPs and Cr2O3-MPs only at 1000 mg/kg bw/day. Cr biodistribution was observed in all the tissues in a dose-dependent manner. The maximum amount of Cr was found in the kidneys and least in the brain of the treated rats. More of the Cr was excreted in the faeces than in the urine. Furthermore, nanotreated rats displayed much higher absorption and tissue accumulation. These findings provide initial data of the probable genotoxicity and biodistribution of NPs and MPs of Cr2O3 generated through repeated oral treatment.

Synthesis, docking and ADMET studies of novel chalcone triazoles for anti-cancer and anti-diabetic activity.

A series of novel chalcone-triazole derivatives were synthesized and screened for in vitro anticancer activity on the human cancer cell lines IMR32 (neuroblastoma), HepG2 (hepatoma) and MCF-7 (breast adenocarcinoma), DU-145 (prostate carcinoma), and A549 (lung adenocarcinoma). Among the tested compounds, 4r showed the most promising anticancer activity in all the cell lines whereas, compounds 4c (IC50 65.86 µM), 4e (IC50 66.28 µM), 4o (IC50 35.81 µM), 4q (IC50 50.82 µM) and 4s (IC50 48.63 µM) showed better activity than the standard doxorubicin (IC50 69.33 µM) in A549 cell line alone. Rat intestinal α-glucosidase inhibitory activity of the synthesized derivatives showed 4m (IC50 67.77 µM), 4p (IC50 74.94 in µM) and 4s (IC50 102.10 µM) as most active compared to others. The in silico docking of synthesized derivatives 4a-4t with DNA topoisomerase IIα revealed the LibDock score in the range of 71.2623-118.29 whereas, compounds 4h, 4m, 4p and 4s with docking target α-glucosidase were in the range of 100.372-107.784.

Anticancer Active Homoisoflavone from the Underground Bulbs of Ledebouria hyderabadensis.

BACKGROUND: Ledebouria is a genus of deciduous or weakly evergreen bulbs in the Hyacinthaceae family. This is recognized as the first collection made of the new taxon Ledebouria hyderabadensis, exist in the Hyderabad city of Andhra Pradesh, India. OBJECTIVE: The goal of this work was to investigate the phytochemical constituents present in the new specifies and also to evaluate the cytotoxic properties of the extracts and pure compounds against human cancer cell lines. MATERIALS AND METHODS: The anticancer activity was evaluated in in vitro mode by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. RESULTS: Phytochemical investigation of underground bulbs of indigenous, rare, and recently identified herb L. hyderabadensis yielded a bioactive homoisoflavanone, Scillascillin 1. The structure of the compound was established on the basis of various nuclear magnetic resonance and mass spectral data. The compound Scillascillin was isolated for the first time from L. hyderabadensis. In vitro anticancer activity, performed using MTT assay, showed compound 1 as significantly active against human cancer cell lines MCF-7 (breast cancer) and DU-145 (prostate cancer) with inhibitory concentration (IC)50 values 9.59 and 11.32 µg/ml respectively when compared with herb methanol extract (IC50 values 36.21 and 44.86 µg/ml respectively).

Assessment of genotoxic effects of lead in occupationally exposed workers.

The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P < 0.01) increase in mean percent tail DNA, frequency of CA, and MN in PBL as well as in BEC as compared to controls. Pb in ambient air and B-Pb concentrations were found to be significantly higher (P < 0.01). The hematocrit, hemoglobin, and red blood cell values were significantly lowered in Pb-exposed workers in comparison to controls. SOD, GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk.

Fabrication, characterization and bioevaluation of silibinin loaded chitosan nanoparticles.

Silibinin is reported to possess multiple biological activities. However, its hydrophobic nature limits its bioavailability compromising in vivo biological activities. Nanoparticles-based delivery of such molecules has emerged as new technique to resolve these issues. Bio-degradable, compatible and adhesive nature of chitosan has recently attracted its suitability as a carrier for biologically active molecules. This study presents fabrication and characterization of chitosan-tripolyphosphate based encapsulation of silibinin. Various preparations of silibinin encapsulated chitosan-tripolyphosphate nanoparticles were studied for particle size, morphology, zeta-potential, and encapsulation efficiencies. Preparations were also evaluated for cytotoxic activities in vitro. The optimized silibinin loaded chitosan nanoparticles were of 263.7±4.1nm in particle size with zeta potential 37.4±1.57mV. Nanoparticles showed high silibinin encapsulation efficiencies (82.94±1.82%). No chemical interactions between silibinin and chitosan were observed in FTIR analysis. Powder X-ray diffraction analysis revealed transformed physical state of silibinin after encapsulation. Surface morphology and thermal behaviour were determined using TEM and DSC analysis. Encapsulated silibinin displayed increased dissolution and better cytotoxicity against human prostate cancer cells (DU145) than silibinin alone.

Toxicity study of cerium oxide nanoparticles in human neuroblastoma cells.

The present study consisted of cytotoxic, genotoxic, and oxidative stress responses of human neuroblastoma cell line (IMR32) following exposure to different doses of cerium oxide nanoparticles (CeO2 NPs; nanoceria) and its microparticles (MPs) for 24 hours. Cytotoxicity was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays whereas genotoxicity was assessed using the cytokinesis-block micronucleus and comet assays. A battery of assays including lipid peroxidation, reactive oxygen species (ROS), hydrogen peroxide, reduced glutathione, nitric oxide, glutathione reductase, glutathione peroxidase, superoxide dismutase, catalase, and glutathione S-transferase were performed to test the hypothesis that ROS was responsible for the toxicity of nanoceria. The results showed that nanosized CeO2 was more toxic than cerium oxide MPs. Hence, further study on safety evaluation of CeO2 NPs on other models is recommended.