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BACKGROUND: Food-grade titanium dioxide (E171), a white colourant widely used in ultra-processed food products, has been banned in the European Union. However, its usage is still permitted in medicines, and in several other countries. The estimated intake of E171 in children is higher than in adults, which led us to hypothesise that E171 induces differential effects depending on age, with adult mice being the most susceptible due to age, despite the lower dose. AIM: To evaluate the effects of oral administration of E171 on intestinal permeability, ileum, and colon histology, and how these effects impact anxious and depressive behaviour in young and adult mice of both sexes. METHODS: Young and adult mice of both sexes C57BL/6 mice received 10 mg/kgbw E171/3 times per week for 3 months. E171 was administered orally in water by pipetting, while control groups only received drinking water, then intestinal permeability, histology and animal behaviour were analysed. RESULTS: E171 showed an amorphous shape, primary particles sized below 1 µm and anatase crystalline structure. Oral administration of E171 disrupted the intestinal permeability in adult male and female mice, but no effects were observed in young mice of both sexes. E171 promoted ileal adenoma formation in half of the adult female population, moreover hyperplastic crypts, and hyperplastic goblet cells at histological level in adult mice of both sexes. The colon presented hyperplastic goblet cells, hyperchromatic nuclei, increased proliferation and DNA damage in adult mice of both sexes. The anxiety and depressive behaviour were only altered in adult mice treated with E171, but no changes were detected in young animals of both sexes. CONCLUSIONS: Adult mice displayed higher susceptibility in all parameters analysed in this study compared to young mice of both sexes.
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Aditivos Alimentares , Nanopartículas , Humanos , Criança , Masculino , Feminino , Animais , Camundongos , Aditivos Alimentares/química , Aditivos Alimentares/farmacologia , Camundongos Endogâmicos C57BL , Alimentos , Intestinos , Titânio/química , Nanopartículas/químicaRESUMO
In the published publication [...].
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Cisplatin (CP) is a chemotherapeutic drug used to treat solid tumors. However, studies have revealed its nephrotoxic effect. Oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction are involved in CP-induced renal damage. Thus, preconditioning (hormetic effect) of ER stress is a strategy to prevent CP-induced renal damage. On the other hand, isoliquiritigenin (IsoLQ) is recognized as a flavonoid with antioxidant properties and an inducer of ER stress. Therefore, we evaluated the ER stress-inducing capacity of IsoLQ and its possible protective effect against CP-induced nephrotoxicity in adult male Wistar rats. The findings reflected that IsoLQ pretreatment might decrease renal damage by reducing plasma creatinine and blood urea nitrogen levels in animals with CP-induced nephrotoxicity. These may be associated with IsoLQ activating ER stress and unfolded protein response (UPR). We found increased messenger RNA levels of the ER stress marker glucose-related protein 78 kDa (GRP78). In addition, we also found that pretreatment with IsoLQ reduced the levels of CCAAT/enhancer-binding protein-homologous protein (CHOP) and X-box-binding protein 1 (XBP1) in the renal cortex, reflecting that IsoLQ can regulate the UPR and activation of the apoptotic pathway. Moreover, this preconditioning with IsoLQ of ER stress had oxidative stress-regulatory effects, as it restored the activity of glutathione peroxidase and glutathione reductase enzymes. Finally, IsoLQ modifies the protein expression of mitofusin 2 (Mfn-2) and voltage-dependent anion channel (VDAC). In conclusion, these data suggest that IsoLQ pretreatment has a nephroprotective effect; it could functionally regulate the ER and mitochondria and reduce CP-induced renal damage by attenuating hormesis-mediated ER stress.
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Apoptose , Cisplatino , Ratos , Animais , Masculino , Cisplatino/toxicidade , Ratos Wistar , Rim , Estresse Oxidativo , Estresse do Retículo EndoplasmáticoRESUMO
We appreciate the interest in our article describing transcriptome changes in a transgenic mouse model carrying an APC gene mutation and would like to reply to the reader [...].
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Titanium dioxide food grade (E171) is one of the most used food additives containing nanoparticles. Recently, the European Food Safety Authority indicated that E171 could no longer be considered safe as a food additive due to the possibility of it being genotoxic and there is evidence that E171 administration exacerbates colon tumor formation in murine models. However, less is known about the effects of E171 accumulation once the exposure stopped, then we hypothesized that toxic effects could be detected even after E171 removal. Therefore, we investigated the effects of E171 exposure after being removed from colon cell cultures. Human colon cancer cell line (HCT116) was exposed to 0, 1, 10 and 50 µg/cm2 of E171. Our results showed that in the absence of cytotoxicity, E171 was accumulated in the cells after 24 of exposure, increasing granularity and reactive oxygen species, inducing alterations in the molecular pattern of nucleic acids and lipids, and causing nuclei enlargement, DNA damage and tubulin depolymerization. After the removal of E171, colon cells were cultured for 48 h more hours to analyze the ability to restore the previously detected alterations. As we hypothesized, the removal of E171 was unable to revert the alterations found after 24 h of exposure in colon cells. In conclusion, exposure to E171 causes alterations that cannot be reverted after 48 h if E171 is removed from colon cells.
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Nanopartículas , Titânio , Animais , Colo , Aditivos Alimentares/toxicidade , Humanos , Camundongos , Nanopartículas/toxicidade , Titânio/toxicidadeRESUMO
Titanium dioxide (TiO2) is present in many different food products as the food additive E171, which is currently scrutinized due to its potential adverse effects, including the stimulation of tumor formation in the gastrointestinal tract. We developed a transgenic mouse model to examine the effects of E171 on colorectal cancer (CRC), using the Cre-LoxP system to create an Apc-gene-knockout model which spontaneously develops colorectal tumors. A pilot study showed that E171 exposed mice developed colorectal adenocarcinomas, which were accompanied by enhanced hyperplasia in epithelial cells, lymphatic nodules at the base of the polyps, and increased tumor size. In the main study, tumor formation was studied following the exposure to 5 mg/kgbw/day of E171 for 9 weeks (Phase I). E171 exposure showed a statistically nonsignificant increase in the number of colorectal tumors in these transgenic mice, as well as a statistically nonsignificant increase in the average number of mice with tumors. Gene expression changes in the colon were analyzed after exposure to 1, 2, and 5 mg/kgbw/day of E171 for 2, 7, 14, and 21 days (Phase II). Whole-genome mRNA analysis revealed the modulation of genes in pathways involved in the regulation of gene expression, cell cycle, post-translational modification, nuclear receptor signaling, and circadian rhythm. The processes associated with these genes might be involved in the enhanced tumor formation and suggest that E171 may contribute to tumor formation and progression by modulation of events related to inflammation, activation of immune responses, cell cycle, and cancer signaling.
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Food-grade titanium dioxide (E171) is a white additive widely used in solid and liquid food products. There is still debate about E171 toxic effects after oral consumption since this additive is deposited in colon, liver, spleen, testis and brain. The consumption of E171 commonly occurs with Western diets that are characterized by a high fat content. Thus, E171 could worsen adverse effects associated with a high fat diet (HFD) such as anxiety, colon diseases and testicular damage. We aimed to evaluate the effects of E171 on anxiety-like behavior, colon, liver and testis and to analyze if the administration of a HFD could exacerbate adverse effects. E171 was administered at ~5 mg/kgbw by drinking water for 16 weeks and mice were fed with a Regular Diet or a HFD. E171 promoted anxiety, induced adenomas in colon, goblet cells hypertrophy and hyperplasia and mucins overexpression, but had no toxic effects on testicular tissue or spermatozoa in regular diet fed-mice. Additionally, E171 promoted microvesicular steatosis in liver in HFD fed-mice and the only HFD administration decreased the spermatozoa concentration and motility. In conclusion, E171 administration increases the number of adenomas in colon, induces hypertrophy and hyperplasia in goblet cells and microvesicular steatosis.
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Adenoma/induzido quimicamente , Ansiedade/induzido quimicamente , Neoplasias do Colo/induzido quimicamente , Dieta Hiperlipídica , Fígado Gorduroso/induzido quimicamente , Alimentos , Células Caliciformes/efeitos dos fármacos , Hiperplasia/induzido quimicamente , Titânio/farmacologia , Animais , Células Caliciformes/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Titânio/administração & dosagem , Titânio/toxicidadeRESUMO
The Organisation for Economic Co-operation and Development has listed thirteen engineered nanomaterials (ENM) in order to investigate their toxicity on human health. Silicon dioxide (SiO2) and titanium dioxide (TiO2) are included on that list and we added indium tin oxide (ITO) nanoparticles (NPs) to our study, which is not listed on OECD suggested ENM to be investigated, however ITO NPs has a high potential of industrial production. We evaluate the physicochemical properties of SiO2 NPs (10-20 nm), TiO2 nanofibers (NFs; 3 µm length) and ITO NPs (<50 nm) and the impact of protein-corona formation on cell internalization. Then, we evaluated the toxicity of uncoated ENM on human lung epithelial cells exposed to 10 and 50 µg/cm2 for 24 h. TiO2 NFs showed the highest capability to adsorb proteins onto the particle surface followed by SiO2 NPs and ITO NPs after acellular incubation with fetal bovine serum. The protein adsorption had no impact on Alizarin Red S conjugation, intrinsic properties for reactive oxygen (ROS) formation or cell uptake for all types of ENM. Moreover, TiO2 NFs induced highest cell alterations in human lung epithelial cells exposed to 10 and 50 µg/cm2 while ITO NPs induced moderated cytotoxicity and SiO2 NPs caused even lower cytotoxicity under the same conditions. DNA, proteins and lipids were mainly affected by TiO2 NFs followed by SiO2 NPs with toxic effects in protein and lipids while limited variations were detected after exposure to ITO NPs on spectra analyzed by Fourier Transform Infrared Spectroscopy.
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Nanoestruturas/química , Nanoestruturas/toxicidade , Coroa de Proteína/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células A549 , Tamanho Celular , Grânulos Citoplasmáticos/metabolismo , Grânulos Citoplasmáticos/ultraestrutura , Células Epiteliais/metabolismo , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Mucosa Respiratória/citologia , Mucosa Respiratória/metabolismo , Dióxido de Silício/química , Dióxido de Silício/metabolismo , Dióxido de Silício/toxicidade , Propriedades de Superfície , Titânio/química , Titânio/metabolismo , Titânio/toxicidade , Cicatrização/efeitos dos fármacosRESUMO
The increasing concern of possible adverse effects on human health derived from occupational engineered nanomaterials (ENMs) exposure is an issue addressed by entities related to provide guidelines and/or protocols for ENMs regulation. Here we analysed 17 entities from America, Europe and Asia, and some of these entities provide limits of exposure extrapolated from the non-nanosized counterparts of ENMs. The international landscape shows that recommendations are mostly made for metal oxide based ENMs and tonnage is one of the main criteria for ENMs registration, however, sub-nanometric ENMs are emerging and perhaps a novel category of ENMs will appear soon. We identify that besides the lack of epidemiological evidence of ENMs toxicity in humans and difficulties in analysing the toxicological data derived from experimental models, the lack of information on airborne concentrations of ENMs in occupational settings is an important limitation to improve the experimental designs. The development of regulations related to ENMs exposure would lead to provide safer work places for ENMs production without delaying the nanotechnology progress but will also help to protect the environment by taking opportune and correct measures for nanowaste, considering that this could be a great environmental problem in the coming future.
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Nanoestruturas/efeitos adversos , Exposição Ocupacional/efeitos adversos , Saúde Ocupacional , Animais , Relação Dose-Resposta a Droga , Guias como Assunto , Humanos , Nível de Efeito Adverso não Observado , Exposição Ocupacional/legislação & jurisprudência , Exposição Ocupacional/prevenção & controle , Exposição Ocupacional/normas , Saúde Ocupacional/legislação & jurisprudência , Saúde Ocupacional/normas , Formulação de Políticas , Medição de Risco , Fatores de Risco , Níveis Máximos PermitidosRESUMO
Food-grade titanium dioxide labeled as E171 has been approved for human consumption by the Food and Drug Administration (USA) and by the European Union for five decades. However, titanium dioxide has been classified as a possible carcinogen for humans by the International Agency of Research in Cancer raising concerns of its oral intake and the translocation to bloodstream, which could disturb barriers such as the blood-testis barrier. There is evidence that titanium dioxide by intragastric/intraperitoneal/intravenous administration induced alterations on testosterone levels, testicular function and architecture, but studies of the E171 effects on the testicle structure and blood-testis barrier are limited. E171 is contained not only in foods in liquid matrix but also in solid ones, which can exert different biological effects. We aimed to compare the effects of E171 consumption in a solid matrix (0.1%, 0.5% and 1% in pellets) and liquid suspension (5 mg/kg body weight) on testis structure, inflammation infiltrate and blood-testis barrier disruption of male BALB/c mice. Results showed that none of the administration routes had influence on body weight but an increase in germ cell sloughing and the infiltrate of inflammatory cells in seminiferous tubules, together with disruption of the blood-testis barrier were similar in testis of both groups even if the dose received in mice in liquid matrix was 136 or 260 times lower than the dose reached by oral intake in solid E171 pellets in 0.5% E171 and 1% E171, respectively. This study highlights the attention on matrix food containing E171 and possible adverse effects on testis when E171 is consumed in a liquid matrix.
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Barreira Hematotesticular/efeitos dos fármacos , Aditivos Alimentares , Nanopartículas Metálicas/toxicidade , Epitélio Seminífero/efeitos dos fármacos , Células de Sertoli/efeitos dos fármacos , Titânio/toxicidade , Ração Animal/análise , Animais , Barreira Hematotesticular/imunologia , Barreira Hematotesticular/patologia , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Água Potável/química , Ingestão de Alimentos/efeitos dos fármacos , Aditivos Alimentares/toxicidade , Antígenos de Histocompatibilidade Classe II/imunologia , Masculino , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da Partícula , Epitélio Seminífero/imunologia , Epitélio Seminífero/patologia , Túbulos Seminíferos/efeitos dos fármacos , Túbulos Seminíferos/imunologia , Túbulos Seminíferos/ultraestrutura , Células de Sertoli/imunologia , Células de Sertoli/ultraestrutura , Propriedades de Superfície , Titânio/administração & dosagem , Titânio/químicaRESUMO
Titanium dioxide nanoparticles (TiO2 NPs) production has been used for pigment, food and cosmetic industry and more recently, shaped as belts for treatment of contaminated water, self-cleaning windows and biomedical applications. However, the toxicological data have demonstrated that TiO2 NPs inhalation induce inflammation in in vivo models and in vitro exposure leads to cytotoxicity and DNA damage. Dermal exposure has limited adverse effects and the possible risks for implants used for tissue regeneration is still under research. Then, it has been difficult to establish a straight statement about TiO2 NPs toxicity since route of exposure and shapes of nanoparticles play an important role in the effects. In this study we aimed to investigate the effect of three different types of TiO2 NPs (industrial, food-grade and belts) dispersed in fetal bovine serum (FBS) and saline solution (SS) on microvessel network, angiogenesis gene expression and femur ossification using a chick embryo model after an acute exposure of NPs on the day 7 after eggs fertilization. Microvascular density of chorioallantoic membrane (CAM) was analyzed after 7days of NPs injection and vehicles induced biological effects per se. NPs dispersed in FBS or SS have slight differences in microvascular density, mainly opposite effect on angiogenesis gene expression and no effects on femur ossification for NPs dispersed in SS. Interestingly, NPs shaped as belts dramatically prevented the alterations in ossification induced by FBS used as vehicle.
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Membrana Corioalantoide/efeitos dos fármacos , Fêmur/efeitos dos fármacos , Nanopartículas Metálicas/química , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Titânio/farmacologia , Animais , Biomarcadores/metabolismo , Bovinos , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Membrana Corioalantoide/metabolismo , Fêmur/crescimento & desenvolvimento , Fêmur/metabolismo , Feto , Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/ultraestrutura , NF-kappa B/genética , NF-kappa B/metabolismo , Osteogênese/genética , Tamanho da Partícula , Titânio/sangue , Titânio/química , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , ZigotoRESUMO
Titanium dioxide nanoparticles (TiO2 NPs) have been classified as possibly carcinogenic to humans and they are an important nanomaterial widely used in pharmaceutical and paint industries. Inhalation is one of the most important routes of exposure in occupational settings. Several experimental models have shown that oxidative stress and inflammation are key mediators of cell damage. In this regard, Nrf2 modulates cytoprotection against oxidative stress and inflammation, however, its role in inflammation induced by TiO2 NPs exposure has been less investigated. The aim of this work was to investigate the role of Nrf2 in the cytokines produced after 4 weeks of TiO2 NPs exposure (5 mg/kg/2 days/week) using wild-type and Nrf2 knockout C57bl6 mice. Results showed that Nrf2 protects against inflammation and oxidative damage induced by TiO2 NPs exposure, however, Nrf2 is a positive mediator in the expression of IFN-γ, TNF-α, and TGF-ß in bronchial epithelium and alveolar space after 4 weeks of exposure. These results suggest that Nrf2 has a central role in up-regulation of cytokines released during inflammation induced by TiO2 NPs and those cytokines are needed to cope with histological alterations in lung tissue.
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Citocinas/metabolismo , Inflamação/etiologia , Pulmão/metabolismo , Nanopartículas Metálicas/toxicidade , Fator 2 Relacionado a NF-E2/metabolismo , Titânio/química , Animais , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Interferon gama/metabolismo , Pulmão/patologia , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/deficiência , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
Titanium dioxide has been classified in the 2B group as a possible human carcinogen by the International Agency for Research on Cancer, and amid concerns of its exposure, cell cycle alterations are an important one. However, several studies show inconclusive effects, mainly because it is difficult to compare cell cycle effects caused by TiO2 nanoparticle (NP) exposure between different shapes and sizes of NP, cell culture types, and time of exposure. In addition, cell cycle is frequently analyzed without cell cycle synchronization, which may also mask some effects. We hypothesized that synchronization after TiO2 NP exposure could reveal dissimilar cell cycle progression when compared with unsynchronized cell population. To test our hypothesis, we exposed lung epithelial cells to 1 and 10 µg/cm(2) TiO2 NPs for 7 days and one population was synchronized by serum starvation and inhibition of ribonucleotide reductase using hydroxyurea. Another cell population was exposed to TiO2 NPs under the same experimental conditions, but after treatments, cell cycle was analyzed without synchronization. Our results showed that TiO2 NP-exposed cells without synchronization had no changes in cell cycle distribution; however, cell population synchronized after 1 and 10 µg/cm(2) TiO2 NP treatment showed a 1.5-fold and 1.66-fold increase, respectively, in proliferation. Synchronized cells also reveal a faster capability of TiO2 NP-exposed cells to increase cell population in the G2/M phase in the following 9 h after synchronization. We conclude that synchronization discloses a greater percentage of cells in the G2/M phase and higher proliferation than TiO2 NP-synchronized cells.
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Ciclo Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Nanopartículas/toxicidade , Titânio/toxicidade , Divisão Celular , Linhagem Celular Tumoral , Humanos , Mitose , Testes de Toxicidade/métodosRESUMO
Titanium dioxide nanoparticles (TiO2 NPs) studies have been performed using relatively high NPs concentration under acute exposure and limited studies have compared shape effects. We hypothesized that midterm exposure to low TiO2 NPs concentration in lung epithelial cells induces carcinogenic characteristics modulated partially by NPs shape. To test our hypothesis we synthesized NPs shaped as belts (TiO2-B) using TiO2 spheres (TiO2-SP) purchased from Sigma Aldrich Co. Then, lung epithelial A549 cells were low-exposed (10 µg/cm(2)) to both shapes during 7 days and internalization, cytokine release and invasive potential were determined. Results showed greater TiO2-B effect on agglomerates size, cell size and granularity than TiO2-SP. Agglomerates size in cell culture medium was 310 nm and 454 nm for TiO2-SP and TiO2-B, respectively; TiO2-SP and TiO2-B induced 23% and 70% cell size decrease, respectively, whilst TiO2-SP and TiO2-B induced 7 and 14-fold of granularity increase. NOx production was down-regulated (31%) by TiO2-SP and up-regulated (70%) by TiO2-B. Both NPs induced a transient cytokine release (IL-2, IL-6, IL-8, IL-4, IFN-γ, and TNF-α) after 4 days, but cytokines returned to basal levels in TiO2-SP exposed cells while TiO2-B induced a down-regulation after 7 days. Midterm exposure to both shapes of NPs induced capability to degrade cellular extracellular matrix components from chorioallantoic membrane and Ki-67 marker showed that TiO2-B had higher proliferative potential than TiO2-SP. We conclude that midterm exposure to low NPs concentration of NPs has an impact in the acquisition of new characteristics of exposed cells and NPs shape influences cellular outcome.