Effects of oral exposure to titanium dioxide nanoparticles on gut microbiota and gut-associated metabolism in vivo

Nanoscale ◽  
2019 ◽  
Vol 11 (46) ◽  
pp. 22398-22412 ◽  
Author(s):  
Zhangjian Chen ◽  
Shuo Han ◽  
Di Zhou ◽  
Shupei Zhou ◽  
Guang Jia
Keyword(s):  
Titanium Dioxide ◽  
Gut Microbiota ◽  
Titanium Dioxide Nanoparticles ◽  
Oral Exposure ◽  
Oral Toxicity

The present study explored the role of gut microbiota and gut-associated metabolism in oral toxicity induced by TiO2 NPs.

scholarly journals Hepatotoxicity and the role of the gut-liver axis in rats after oral administration of titanium dioxide nanoparticles

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Zhangjian Chen ◽  
Di Zhou ◽  
Shuo Han ◽  
Shupei Zhou ◽  
Guang Jia
Keyword(s):  
Titanium Dioxide ◽  
Gut Microbiota ◽  
Titanium Dioxide Nanoparticles ◽  
Oral Exposure ◽  
Sequencing Analysis ◽  
Dependent Manner ◽  
Indirect Pathway ◽  
Rdna Sequencing ◽  
Underlying Mechanisms

Abstract Background Due to its excellent physicochemical properties and wide applications in consumer goods, titanium dioxide nanoparticles (TiO2 NPs) have been increasingly exposed to the environment and the public. However, the health effects of oral exposure of TiO2 NPs are still controversial. This study aimed to illustrate the hepatotoxicity induced by TiO2 NPs and the underlying mechanisms. Rats were administered with TiO2 NPs (29 nm) orally at exposure doses of 0, 2, 10, 50 mg/kg daily for 90 days. Changes in the gut microbiota and hepatic metabolomics were analyzed to explore the role of the gut-liver axis in the hepatotoxicity induced by TiO2 NPs. Results TiO2 NPs caused slight hepatotoxicity, including clear mitochondrial swelling, after subchronic oral exposure at 50 mg/kg. Liver metabolomics analysis showed that 29 metabolites and two metabolic pathways changed significantly in exposed rats. Glutamate, glutamine, and glutathione were the key metabolites leading the generation of energy-related metabolic disorders and imbalance of oxidation/antioxidation. 16S rDNA sequencing analysis showed that the diversity of gut microbiota in rats increased in a dose-dependent manner. The abundance of Lactobacillus_reuteri increased and the abundance of Romboutsia decreased significantly in feces of TiO2 NPs-exposed rats, leading to changes of metabolic function of gut microbiota. Lipopolysaccharides (LPS) produced by gut microbiota increased significantly, which may be a key factor in the subsequent liver effects. Conclusions TiO2 NPs could induce slight hepatotoxicity at dose of 50 mg/kg after long-term oral exposure. The indirect pathway of the gut-liver axis, linking liver metabolism and gut microbiota, played an important role in the underlying mechanisms.

Exploration of cytotoxic and genotoxic endpoints following sub-chronic oral exposure to titanium dioxide nanoparticles

2019 ◽  
Vol 35 (9) ◽  
pp. 577-592 ◽  
Author(s):  
Srijita Chakrabarti ◽  
Danswrang Goyary ◽  
Sanjeev Karmakar ◽  
Pronobesh Chattopadhyay
Keyword(s):  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Flow Cytometric Analysis ◽  
Raw 264.7 Cells ◽  
Oral Exposure ◽  
Chromosomal Breakage ◽  
Flow Cytometric ◽  
Higher Doses

Health hazards of titanium dioxide nanoparticles (TiO2-NPs) have raised severe concerns because of the paucity of information regarding the toxic effects among the population. In the present research, the in vitro and in vivo cytotoxic potential of TiO2-NPs were evaluated using flow cytometric techniques. Further, in vitro and in vivo genotoxic endpoints were estimated by means of comet, micronucleus (MN), and chromosomal aberration (CA) assays. In vitro analysis was performed at the concentration range of 10–100 µg/mL using murine RAW 264.7 cells. In vivo experiments were conducted on Albino mice (M/F) by exposing them to 200 and 500 mg/kg TiO2-NPs for 90 days. Decreased percentage of cell viability with higher doses of TiO2-NPs was evident in both in vitro and in vivo flow cytometric analysis. Further, an impaired cell cycle (G0/G1, S, and G2/M) was reflected in the present investigation following the exposure to TiO2-NPs. Increased comet scores such as tail length, % DNA in tail, tail moment, and olive moment were also observed with the higher doses of TiO2-NPs in vitro and in vivo comet assays. Finally, the in vivo MN and CA assays revealed the formation of MN and chromosomal breakage following the exposure to TiO2-NPs.

scholarly journals The DNA Sensor AIM2 Protects against Streptozotocin-Induced Type 1 Diabetes by Regulating Intestinal Homeostasis via the IL-18 Pathway

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 959 ◽  
Author(s):  
Jefferson Antônio Leite ◽  
Gabriela Pessenda ◽  
Isabel C. Guerra-Gomes ◽  
Alynne Karen Mendonça de Santana ◽  
Camila André Pereira ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Gut Microbiota ◽  
Bacterial Translocation ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Dna Sensor ◽  
Proinflammatory Response

Pattern recognition receptors (PRRs), such as Nod2, Nlrp3, Tlr2, Trl4, and Tlr9, are directly involved in type 1 diabetes (T1D) susceptibility. However, the role of the cytosolic DNA sensor, AIM2, in T1D pathogenesis is still unknown. Here, we demonstrate that C57BL/6 mice lacking AIM2 (AIM2−/−) are prone to streptozotocin (STZ)-induced T1D, compared to WT C57BL/6 mice. The AIM2−/− mice phenotype is associated with a greater proinflammatory response in pancreatic tissues, alterations in gut microbiota and bacterial translocation to pancreatic lymph nodes (PLNs). These alterations are related to an increased intestinal permeability mediated by tight-junction disruption. Notably, AIM2−/− mice treated with broad-spectrum antibiotics (ABX) are protected from STZ-induced T1D and display a lower pancreatic proinflammatory response. Mechanistically, the AIM2 inflammasome is activated in vivo, leading to an IL-18 release in the ileum at 15 days after an STZ injection. IL-18 favors RegIIIγ production, thus mitigating gut microbiota alterations and reinforcing the intestinal barrier function. Together, our findings show a regulatory role of AIM2, mediated by IL-18, in shaping gut microbiota and reducing bacterial translocation and proinflammatory response against insulin-producing β cells, which ultimately results in protection against T1D onset in an STZ-induced diabetes model.

scholarly journals Unraveling the neurotoxicity of titanium dioxide nanoparticles: focusing on molecular mechanisms

2016 ◽  
Vol 7 ◽  
pp. 645-654 ◽  
Author(s):  
Bin Song ◽  
Yanli Zhang ◽  
Jia Liu ◽  
Xiaoli Feng ◽  
Ting Zhou ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Titanium Dioxide ◽  
Molecular Mechanisms ◽  
Titanium Dioxide Nanoparticles ◽  
Brain Dysfunction ◽  
In Vivo Studies ◽  
Cell Components ◽  
New Perspective ◽  
The Brain

Titanium dioxide nanoparticles (TiO2 NPs) possess unique characteristics and are widely used in many fields. Numerous in vivo studies, exposing experimental animals to these NPs through systematic administration, have suggested that TiO2 NPs can accumulate in the brain and induce brain dysfunction. Nevertheless, the exact mechanisms underlying the neurotoxicity of TiO2 NPs remain unclear. However, we have concluded from previous studies that these mechanisms mainly consist of oxidative stress (OS), apoptosis, inflammatory response, genotoxicity, and direct impairment of cell components. Meanwhile, other factors such as disturbed distributions of trace elements, disrupted signaling pathways, dysregulated neurotransmitters and synaptic plasticity have also been shown to contribute to neurotoxicity of TiO2 NPs. Recently, studies on autophagy and DNA methylation have shed some light on possible mechanisms of nanotoxicity. Therefore, we offer a new perspective that autophagy and DNA methylation could contribute to neurotoxicity of TiO2 NPs. Undoubtedly, more studies are needed to test this idea in the future. In short, to fully understand the health threats posed by TiO2 NPs and to improve the bio-safety of TiO2 NPs-based products, the neurotoxicity of TiO2 NPs must be investigated comprehensively through studying every possible molecular mechanism.

scholarly journals Quercetin and Idebenone Ameliorate Oxidative Stress, Inflammation, DNA damage, and Apoptosis Induced by Titanium Dioxide Nanoparticles in Rat Liver

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581881218 ◽  
Author(s):  
Laila M. Fadda ◽  
Hanan Hagar ◽  
Azza M. Mohamed ◽  
Hanaa M. Ali
Keyword(s):  
Titanium Dioxide ◽  
Histopathological Examination ◽  
Titanium Dioxide Nanoparticles ◽  
Reactive Protein ◽  
Wide Range ◽  
Factor Α ◽  
Immunoglobin G ◽  
Endothelial Growth Factor

Titanium dioxide nanoparticles (TiO2-NPs) are extensively used in a wide range of applications; however, many reports have investigated their nanotoxicological effect at the molecular level either in vitro or in vivo systems. The defensive roles of quercetin (Qur) or idebenone (Id) against the hepatotoxicity induced by TiO2-NPs were evaluated in the current study. The results showed that the coadministration of Qur or Id to rats intoxicated with TiO2-NPs markedly ameliorated the elevation in hepatic malondialdehyde (MDA), serum alanine amino-transferase (ALT), glucose, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), immunoglobin G (IgG), and C-reactive protein (CRP) levels compared to their levels in TiO2-NPs-treated rats. The aforementioned antioxidants also effectively modulated the changes in the levels of serum vascular endothelial growth factor (VEGF), nitric oxide (NO), hepatic DNA breakage, caspase-3, and inhibition of drug metabolizing enzymes (cytochrome P450s; CYP4502E12E1) in rat livers induced by TiO2-NPs toxicity. The histopathological examination of the liver section showed that TiO2-NPs caused severe degeneration of most hepatocytes with an increase in collagen in the portal region, while treatment with the antioxidants in question improved liver architecture. These outcomes supported the use of Qur and Id as protective agents against the hepatotoxicity induced by TiO2-NPs and other hepatotoxic drugs.

Effect of Gut Microbiota on the Metabolism of Chemical Constituents of Berberis kansuensis Extract Based on UHPLC-Orbitrap-MS Technique

Planta Medica ◽  
2021 ◽  
Author(s):  
Huan Du ◽  
Tong Xu ◽  
Huan Yi ◽  
Xinmei Xu ◽  
Chengcheng Zhao ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
High Performance ◽  
Chemical Constituents ◽  
Chemical Components ◽  
Serum Samples ◽  
Chromatography Method ◽  
Metabolic Transformation ◽  
Orbitrap Ms

AbstractThe dried stem bark of Berberis kansuensis is a commonly used Tibetan herbal medicine for the treatment of diabetes. Its main chemical components are alkaloids, such as berberine, magnoflorine and jatrorrhizine. However, the role of gut microbiota in the in vivo metabolism of these chemical components has not been fully elucidated. In this study, an ultra-high performance liquid chromatography method coupled with Orbitrap mass spectrometry (UHPLC-Orbitrap-MS) technology was applied to detect and identify prototype components and metabolites in rat intestinal contents and serum samples after oral administration of a B. kansuensis extract. A total of 16 prototype components and 40 metabolites were identified. The primary metabolic pathways of the chemical components from B. kansuensis extract were demethylation, desaturation, deglycosylation, reduction, hydroxylation, and other conjugation reactions including sulfation, glucuronidation, glycosidation, and methylation. By comparing the differences of metabolites between diabetic and pseudo-germ-free diabetic rats, we found that the metabolic transformation of some chemical components in B. kansuensis extract such as bufotenin, ferulic acid 4-O-β-D-glucopyranoside, magnoflorine, and 8-oxyberberine, was affected by the gut microbiota. The results revealed that the gut microbiota can affect the metabolic transformation of chemical constituents in B. kansuensis extract. These findings can enhance our understanding of the active ingredients of B. kansuensis extract and the key role of the gut microbiota on them.

Effect of oral exposure to titanium dioxide nanoparticles on lipid metabolism in Sprague-Dawley rats

Nanoscale ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 5973-5986 ◽  
Author(s):  
Zhangjian Chen ◽  
Shuo Han ◽  
Pai Zheng ◽  
Di Zhou ◽  
Shupei Zhou ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Lipid Metabolism ◽  
Titanium Dioxide Nanoparticles ◽  
Oral Exposure ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

The present study investigated the effect of oral exposure to TiO2 NPs on lipid metabolism by serum lipidomics.

scholarly journals Titanium Dioxide Nanoparticles Elicit Lower Direct Inhibitory Effect on Human Gut Microbiota Than Silver Nanoparticles

2019 ◽  
Vol 172 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Richard T Agans ◽  
Alex Gordon ◽  
Saber Hussain ◽  
Oleg Paliy
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Gut Microbiota ◽  
Titanium Dioxide Nanoparticles ◽  
Close Association ◽  
Community Diversity ◽  
Bacterial Cells ◽  
Human Gut ◽  
Human Gut Microbiota

Abstract Due to continued technological development, people increasingly come in contact with engineered nanomaterials (ENMs) that are now used in foods and many industrial applications. Many ENMs have historically been shown to possess antimicrobial properties, which has sparked concern for how dietary nanomaterials impact gastrointestinal health via microbial dysbiosis. We employed an in vitro Human Gut Simulator system to examine interactions of dietary nano titanium dioxide (TiO2) with human gut microbiota. Electron microscopy indicated a close association of TiO2 particles with bacterial cells. Addition of TiO2 to microbial communities led to a modest reduction in community density but had no impact on community diversity and evenness. In contrast, administration of known antimicrobial silver nanoparticles (NPs) in a control experiment resulted in a drastic reduction of population density. In both cases, communities recovered once the addition of nanomaterials was ceased. Constrained ordination analysis of community profiles revealed that simulated colonic region was the primary determinant of microbiota composition. Accordingly, predicted community functional capacity and measured production of short-chain fatty acids were not changed significantly upon microbiota exposure to TiO2. We conclude that tested TiO2 NPs have limited direct effect on human gut microbiota.

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