OBJECTIVE: To explore the effects and related mechanisms of oral exposure titanium dioxide nanoparticles (TiO₂ NPs) for 90 days on the intestinal and the gut microbiota of rats, through fecal metabolomics. METHODS: Twelve 4-week-old clean-grade Sprague Dawley (SD) rats were randomly de-vided into 2 groups by body weight, treated with TiO₂ NPs at dose of 0 or 50 mg/kg body weight everyday respectively for 90 days. The solution of each infection was freshly prepared and shocked fully by ultrasonic. Characterization of the particle size, crystal form, purity, and specific surface area of TiO₂ NPs was conducted. And the fresh feces of the rats were collected on the 90th day. After lyophilized and hydrophilic phase extraction, ultra performance liquid chromatography-Q-exactive orbitrap-high-resolution mass spectrometry system (UPLC-QEMS) was utilized for non-targeted determination of fecal meta-bolites. The metabolites were identified and labeled through Compound Discoverer 3.0 software, and used for subsequent metabolomics analysis. Bioinformatics analysis was carried out including unsupervised principal component analysis and supervised orthogonal projection to latent structure discriminant analysis for the differential metabolites between the two groups. The differential metabolites were followed-up for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. RESULTS: Compared with the control group, the body weight of the rats was significantly reduced (P<0.05) in the treatment group. A total of 22 metabolites in fecal metabolomics showed significant changes. Among them, xanthine, 1-methyladenine, 3-hydroxypyridine, methionine sulfoxide, pyridoxine, 1,5-isoquinolinediol, N-acetylornithine, N-acetyl-D-galactosamine, L-citrulline, L-methionine, leucine, DL-tryptophan, L-ornithine, 4-methyl-5-thiazoleethanol, and L-glutamic acid totaled 15 metabolites increased significantly. N-acetylhistamine, D-pipecolinic acid, imidazolelactic acid, L-valine, 2,3,4,6-tetramethylpyrazine, caprolactam, and histamine totaled 7 metabolites decreased significantly. N-acetylhistamine, L-valine and methionine sulfoxide were changed more than 16 times. Analysis of KEGG pathway revealed that the two metabolic pathways arginine biosynthesis and aminoacyl-tRNA biosynthesis were significantly changed (false discover rate < 0.05, pathway impact > 0.1). CONCLUSION Oral exposure to TiO₂ NPs for 90 days could disrupt the metabolism of the intestine and gut microbiota, causing significant changes in metabolites and metabolic pathways which were related to inflammatory response, oxidative stress, glucose homeostasis, blood system and amino acid homeostasis in rat feces. It is suggested that the toxic effect of TiO₂ NPs on rats may be closely related to intestinal and gut microbiota metabolism.
Administration, Oral ; Animals ; Feces ; Metabolome ; Metal Nanoparticles ; Rats ; Rats, Sprague-Dawley ; Titanium

OBJECTIVE1H magnetic resonance (1H MR) spectroscopic technique in combination with pattern recognition technique were applied to analyze toxic effects of rats which were intratracheally instilled with titanium dioxide nanoparticles (nano-TiO2) as well as to detect the target organs and biomarkers associated with the toxic effects.

METHODSTwenty-four SD male rats were divided into 4 groups randomly which were high dose group (40 mg/kg nano-TiO2), moderate dose group (4 mg/kg nano-TiO2), low dose group (0.4 mg/kg nano-TiO2) and control group (0.9% NaCl solution) respectively, there were six rats per group. All rats were exposed to the object by single intratracheally instilling at a volume of 0.1 ml/100 g. After one week observation, 1H MR spectra of plasma were measured and analyzed by principal component analysis. Histopathologic examination for tissues such as heart, lung, liver, and kidney were performed simultaneously.

RESULTSThe relative content of lactate [(37.86+/-2.58)x10(-3)], citrate [(2.21+/-0.45)x10(-3)], choline [(7.74+/-0.76)x10(-3)] and creatine [(4.17+/-1.15)x10(-3)] in high dose group were significantly decreased as compared with those [(52.07+/-5.12)x10(-3), (3.01+/-0.21)x10(-3), (9.28+/-0.78)x10(-3), (8.59+/-2.64)x10(-3)] in control group (t values were -6.024, -3.177, -3.374, -4.215 respectively, P<0.05), however the relative content of glucose [(19.41+/-1.72)x10(-3)] was significantly increased compared with that [(14.45+/-2.45)x10(-3)] in control group (t value was 2.802, P<0.05). The relative content of lactate [(44.39+/-5.09)x10(-3)] and creatine [(3.67+/-0.76)x10(-3)] in moderate group was significantly decreased compared with those [(52.07+/-5.12)x10(-3), (8.59+/-2.64)x10(-3)] in control group (t values were -3.254, -4.694 respectively, P<0.05). The relative content of pyruvate [(3.84+/-0.70)x10(-3)] was significantly increased in low dose group as compared with that [(3.13+/-0.46)x10(-3)] in control group (t value was 2.787, P<0.05), however the relative content of creatine [(8.10+/-0.72)x10(-3)] was significantly decreased compared with that [(9.28+/-0.78)x10(-3)] in control group (t value was -2.602, P<0.05). No significant difference was found between other experimental groups and control group. No visible damage was found in histopathologic examination.

CONCLUSIONLung, liver, kidney and heart were the target organs of rats which were intratracheally instilling titanium dioxide nanoparticles. Lactate, pyruvate, glucose, citrate, choline and creatine can be presumed as the biomarkers when searching the target organs of the toxic effects.

Animals ; Male ; Metal Nanoparticles ; Plasma ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Titanium ; administration & dosage ; toxicity

To study the effects of nano elemental selenium (Nano-Se) or sodium selenite (Na2SeO3) on the activities of glutathione peroxidase (GSH-Px) and Type-I deiodinase in the liver. A total of 234 weanling pigs (Duroc x Landrace x Yorkshire) at an average initial body weight of 8.3 kg were allocated to 13 treatments. The thirteen dietary treatments were basal diet only (containing 0.04 mg/kg Se), basal diet + 0.1, 0.2, 0.3, 0.4, 0.5, 1.0 mg/kg Se as Na2SeO3 or Nano-Se, respectively. The results were as follows: Supplementation with 1.0 mg/ kg Se as Na2SeO3 reduced (P < 0.05) growth performance and GSH-Px activities as compared with the addition of a concentration range of 0.20-0.40 mg/kg Se. When Nano-Se was added to the diet, the growth and GSH-Px activities remained steady at the peak value as at a concentration of 1.0 mg/kg Se; There were no difference in the activities of GSH-Px between the treatments of Nano-Se and Na2SeO3 when added concentration of Se was 0.10-0.40 mg/kg. The pigs had higher (P < 0.05) activities of GSH-Px at a concentration range of 0.50 and 1.0 mg/kg as Nano-Se than Na2SeO3; Supplentation with Se increased the activity of Type- I deiodinase in liver, however, the increased extent was affected by neither Se sources nor added concentration of Se. The results implicated that for the best concentration range of Weinberg curve, Nano-Se is wider than Na2SeO3.
Animals ; Dose-Response Relationship, Drug ; Glutathione Peroxidase ; metabolism ; Iodide Peroxidase ; metabolism ; Liver ; enzymology ; Metal Nanoparticles ; administration & dosage ; Selenium ; administration & dosage ; pharmacology ; Sodium Selenite ; administration & dosage ; pharmacology ; Swine

OBJECTIVE: To establish a proper animal model of pyogenic spondylitis, to evaluate the efficacy of silver nanoparticles for treatment of spinal pyogenic infections, and to explore the distribution of the particles in the body of the animals. METHODS: Staphylococcus aureus was inoculated into intervertebral discs of rabbits to establish a spinal pyogenic infection model. These rabbits were divided into Group A [0.1 mg/(kg.d)], Group B [1 mg/(kg.d)], and a Control group. Groups A and B were injected with different doses of silver nanoparticles solution daily at locally infected side. Two weeks later, bacterial cultures, radiographic outcomes, histopathology were analyzed. Atomic absorption spectrometry was utilized to measure silver contents in some vital organs of the rabbits to detect the distribution and accumulation of silver particles. RESULTS: Staphylococcus aureus (100 CFU/mL), induced 100% pyogenic spondylitis. 1 mg/kg dose of silver nanoparticles solution could effectively inhibit the occurrence of spinal pyogenic infection with the effective rate of 75%. While the effect of 0.1 mg/kg dose of silver nanoparticles solution was less obvious, the efficiency was only 25%. Significant numbers of silver nanoparticles were observed to accumulate in the animal. In the 1 mg/kg group silver was deposited mainly in the spinal cord, liver, kidneys, spleen, and testicles, while in the 0.1 mg/kg group it accumulated only in the spinal cord. CONCLUSION Local administration of silver nanoparticles can effectively prevent and treat pyogenic spondylitis; the particles accumulate in the body commensurate with the administered drug concentration.
Animals ; Infusions, Intralesional ; Lumbar Vertebrae ; Male ; Metal Nanoparticles ; administration & dosage ; Rabbits ; Silver ; administration & dosage ; pharmacology ; Spondylitis ; drug therapy ; microbiology ; Staphylococcal Infections ; drug therapy

OBJECTIVETo investigate the influence of intranasal instilling titanium dioxide (TiO2) nanoparticles on monoaminergic neurotransmitters at different-time exposure.

METHODSCD female mice were intranasally instilled three different-sized (25 nm, 80 nm and 155 nm) TiO, suspension every other day in a dose of 50 mg/kg body weight. The control group was instilled the same volume of Milli-Q water. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to analyze the titanium contents in murine brain after exposure to TiO2 particles 2 days, 10 days, 20 days and 30 days. The monoaminergic neurotransmitters such as norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), 5-hydroxyindole acetic acid (5-HIAA), 3, 4-dihydroxyphenylacetic acid (DOPAC), and homovanillic (HVA), were determined by reversed-phase high performance liquid chromatography (RP-HPLC) with electrochemical detector.

RESULTSAfter exposure to TiO, nanoparticles 10 days, the titanium contents in murine brain were increased, the titanium content in the 25 nm group was up to (1059.3 +/- 293.5) ng/g. In 20 days, the titanium content decreased slowly with the metabolism of titanium in vivo, but it kept at a high level, the content decreased to (654.7 +/- 269.2) ng/g in the 25 nm group. After exposure to TiO2 nanoparticles 30 days, the titanium contents had no obviously change. Because of the accumulation of TiO, in the brain, the contents of NE and 5-HT increased significantly after exposure to 80 nm and 155 nm TiO, nanoparticles 20 days, while the decreased contents of DA, DOPAC, HVA and 5-HIAA were observed.

CONCLUSIONThe inhaled TiO2 nanoparticles could be translocated to and deposited in murine brain after absorbing by nasal mucosa, and further influence the releases and metabolisms of monoaminergic neurotransmitters in brain.

Administration, Intranasal ; Animals ; Biogenic Monoamines ; metabolism ; Brain ; drug effects ; metabolism ; Brain Chemistry ; Female ; Metal Nanoparticles ; Mice ; Neurotransmitter Agents ; metabolism ; Time ; Titanium ; administration & dosage ; pharmacology

This study was purposed to evaluate whether the safe concentration of magnetic nanoparticles of Fe₃O₄(MNPs-Fe₃O₄) for monocytes could induce the SKM-1 cell apoptosis. The average size and Zeta potential of MNPs-Fe₃O₄were determined by transmission electron microscopy and the Malvern Zetasizer 3000 HS, respectively. The cell viability after being exposed to MNPs-Fe₃O₄for 12, 24, 48, and 72 hours was detected by using cell count Kit-8. The cell apoptosis was evaluated by flow cytometry with Annexin V/PI double staining and Wright-Giemsa staining. The cell cycle was measured by flow cytometry. The levels of active caspase-3, survivin and bcl-rambo in cells treated with MNPs-Fe₃O₄and/or trolox for 48 hours were detected with Western blot. The results showed that the cell viability decreased in SKM-1 cells after exposure to 50 µmol/L and 100 µmol/L MNPs-Fe₃O₄(P < 0.05), but did not in monocytes (P > 0.05), compared with that of each non-MNPs-Fe₃O₄-treated group. This exposure also induced the SKM-1 cells to be arrested in G0/G1. Annexin V/PI staining assay showed that cell apoptotic rate induced by 100 µmol/L MNPs-Fe₃O₄was significantly high in SKM-1 cells while not so high in monocytes, and the pretreatment with trolox could attenuate the apoptosis. Moreover, the active caspase-3 increased in SKM-1 cells after the exposure to MNPs-Fe₃O₄, while that was not in monocytes, and the increased expression of BCL-rambo and the decreased expression of survivin involved in the process were also observed. It is concluded that MNPs-Fe₃O₄can induce the caspase 3-dependent SKM-1 cell apoptosis by increasing the BCL-rambo expression and decreasing the survivin expression, but this cytotoxic effect can not be observed in monocyte's.
Apoptosis ; drug effects ; Caspase 3 ; Cell Cycle ; Cell Line, Tumor ; Ferric Compounds ; pharmacology ; Flow Cytometry ; Humans ; Magnetics ; Metal Nanoparticles ; administration & dosage

Platinum nanoparticles (PtNP) exhibit remarkable antioxidant activity. There is growing evidence concerning a positive relationship between oxidative stress and bone loss, suggesting that PtNP could protect against bone loss by modulating oxidative stress. Intragastric administration of PtNP reduced ovariectomy (OVX)-induced bone loss with a decreased level of activity and number of osteoclast (OC) in vivo. PtNP inhibited OC formation by impairing the receptor activator of nuclear factor-kappaB ligand (RANKL) signaling. This impairment was due to a decreased activation of nuclear factor-kappaB and a reduced level of nuclear factor in activated T-cells, cytoplasmic 1 (NFAT2). PtNP lowered RANKL-induced long lasting reactive oxygen species as well as intracellular concentrations of Ca2+ oscillation. Our data clearly highlight the potential of PtNP for the amelioration of bone loss after estrogen deficiency by attenuated OC formation.
Animals ; Metal Nanoparticles/*administration & dosage ; Mice ; Mice, Inbred C57BL ; NFATC Transcription Factors/metabolism ; *Osteoclasts/drug effects/physiology ; Osteoporosis/drug therapy ; Ovariectomy/adverse effects ; Oxidative Stress/drug effects ; Platinum/*administration & dosage ; *RANK Ligand/genetics/metabolism ; Reactive Oxygen Species/metabolism ; Signal Transduction