RESUMO
This study proposed to determine global microRNA (miRNA) expression and miRNA-regulated pathways in Intestinal Neuronal Dysplasia type B (IND-B). Fifty patients (0-15 years old) with IND-B were included in the study. Peripheral blood samples were collected from all 50 patients and from 10 healthy asymptomatic children (controls). Rectal biopsies were collected from 29/50 patients; biopsy tissues were needle microdissected to isolate the different intestinal layers, for molecular analysis. Global miRNA expression was determined using TaqMan arrays. Correlation analysis between miRNA expression in plasma and biopsy samples as well as among tissues derived from the distinct intestinal layers was performed. Computational approaches were used for miRNA target prediction/identification of miRNA-regulated genes and enriched pathways biologically relevant to IND-B pathogenesis. miRNAs were statistically significantly deregulated (FC ≥ 2 and p ≤ 0.05) in submucosal and muscular layers: over-expressed (miR-146a and miR-146b) and under-expressed (miR-99a, miR-100, miR-130a, miR-133b, miR-145, miR-365, miR-374-5p, miR-451). Notably, let-7a-5p was highly over-expressed in patient plasma compared to healthy controls (FC = 17.4). In addition, miR-451 was significantly under-expressed in both plasma and all biopsy tissues from the same patients. Enriched pathways (p < 0.01) were axon guidance, nerve growth factor signalling, NCAM signalling for neurite out-growth, neuronal system and apoptosis. miRNA expression is deregulated in the submucosa and muscular layers of the rectum and detected in plasma from patients with IND-B. Biologically enriched pathways regulated by the identified miRNAs may play a role in IND-B disease pathogenesis, due to the activity related to the neurons of the enteric nervous system.
Assuntos
Biologia Computacional/métodos , Enteropatias/genética , Enteropatias/patologia , MicroRNAs/genética , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/patologia , Transcriptoma , Adolescente , Apoptose , Orientação de Axônios , Biópsia , Criança , Pré-Escolar , Feminino , Perfilação da Expressão Gênica , Humanos , Lactente , Recém-Nascido , Enteropatias/sangue , Masculino , Fatores de Crescimento Neural/metabolismo , Doenças do Sistema Nervoso/sangue , Moléculas de Adesão de Célula Nervosa/metabolismo , Reto/patologiaRESUMO
Red and processed meat consumption has been strongly related to increase the risk of colorectal cancer (CRC), although its impact is largely unknown. Hemin, an iron-containing porphyrin, is acknowledged as a putative factor of red and processed meat pro-carcinogenic effects. The aim of this study was to investigate the effects of high dietary hemin on the promotion/progression stages of 1,2-dimethylhydrazine (1,2-DMH)-induced colon carcinogenesis. Twenty-four Wistar male rats were given four subcutaneous 1,2-DMH injections and received either balanced diet or balanced diet supplemented with hemin 0.5â¯mmol/kg for 23 weeks. Colon specimens were analyzed for aberrant crypt foci (ACF) and tumor development. Dietary hemin significantly increased ACF number and fecal water cytotoxicity/genotoxicity in Caco-2 cells when compared to 1,2-DMH control group. However, tumor incidence, multiplicity and cell proliferation did not differ between 1,2-DMHâ¯+â¯hemin and 1,2-DMH control group. Gene expression analysis of 91 target-genes revealed that only three genes (Figf, Pik3r5 and Tgfbr2) were down-regulated in the tumors from hemin-fed rats compared to those from 1,2-DMH control group. Therefore, the findings of this study show that high hemin intake promotes mainly DNA damage and ACF development and but does not change the number nor incidence of colon tumors induced by 1,2-DMH in male rats.
Assuntos
Focos de Criptas Aberrantes/induzido quimicamente , Neoplasias do Colo/induzido quimicamente , Dano ao DNA , Hemina/toxicidade , Lesões Pré-Cancerosas/induzido quimicamente , 1,2-Dimetilidrazina , Ração Animal , Animais , Células CACO-2 , Cocarcinogênese , Ensaio Cometa , Regulação para Baixo/efeitos dos fármacos , Fezes , Humanos , Masculino , Fosfatidilinositol 3-Quinase/genética , Ratos , Ratos Wistar , Receptor do Fator de Crescimento Transformador beta Tipo II/biossíntese , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Carne Vermelha , Fatores de Tempo , Fator D de Crescimento do Endotélio Vascular/biossíntese , Fator D de Crescimento do Endotélio Vascular/genéticaRESUMO
Previous studies have shown that early life intake of high-fat diet or western-style diet (WD) enhances the development of mammary tumors in adult female rats. Thus, we hypothesized that maternal WD throughout pregnancy and the lactation period could speed up the development of MNU-induced mammary tumors and alter their gene expression. For this, the present study investigated the gene expression profile of chemically-induced mammary tumors in female rat offspring from dams fed a WD or a control diet. Pregnant female Sprague-Dawley rats received a WD (high-fat, low-fiber and oligoelements) or a control diet from gestational day 12 until post-natal day (PND) 21. At PND 21, female offspring received a single dose of N-Methyl-N-Nitrosourea (MNU, 50 mg/kg body weight) and were fed a control diet for 13 weeks. Tumor incidence, multiplicity, and latency were recorded and mammary gland samples were collected for histopathology and gene expression analysis. Tumor multiplicity and histological grade were significantly higher and tumor latency was lower in WD offspring compared to control offspring. Transcriptome profiling identified 57 differentially expressed genes in tumors from WD offspring as compared to control offspring. There was also an increase in mRNA expression of genes such as Emp3, Ccl7, Ets1, Abcc5, and Cyr61, indicative of more aggressive disease detected in tumors from WD offspring. Thus, maternal WD diet increased MNU-induced mammary carcinogenesis in adult female offspring through transcriptome changes that resulted in a more aggressive disease.
Assuntos
Dieta Hiperlipídica , Dieta Ocidental , Neoplasias Mamárias Animais/etiologia , Fenômenos Fisiológicos da Nutrição Materna , Complicações na Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , Transcriptoma , Animais , Feminino , Perfilação da Expressão Gênica , Genes Neoplásicos , Lactação , Neoplasias Mamárias Animais/induzido quimicamente , Neoplasias Mamárias Animais/patologia , Metilnitrosoureia , Mães , Gradação de Tumores , Gravidez , RNA Mensageiro/metabolismo , Ratos Sprague-DawleyRESUMO
The risk of developing colorectal cancer (CRC) could be associated with red and processed meat intake. Experimental data supports that hemin iron, found abundantly in red meat, promotes CRC in mice and rats, while indole-3 carbinol (I3C) and synbiotics (syn) exert anti-carcinogenic activities in most studies of colon carcinogenesis. This study aimed to investigate the modifying effects of I3C and syn (inulin + Bifidobacterium lactis), given separately or together, on dimethylhidrazine (DMH)-induced colon carcinogenesis in hemin-fed rats. All animals were given four subcutaneous DMH injections and then, two weeks after carcinogen exposure, they began a basal diet containing hemin, hemin + I3C, hemin + syn, or hemin + I3C + syn for 23 weeks. The combination of I3C + syn significantly increased fecal water genotoxicity, tumor volume and invasiveness when compared to the hemin-fed control group. The groups fed I3C or syn alone had a significant reduction in the number of preneoplastic aberrant crypt foci (ACF) lesions compared to the hemin-fed group. Dietary I3C also reduced fecal water genotoxicity. Gene expression analysis of colorectal tumors demonstrated that the combination of dietary I3C + syn increased transcript levels for Raf1 and decreased tumor progression and invasiveness related to the genes Cdh1 and Appl1. This analysis also revealed that the Tnf and Cdh1 genes were significantly up- and down-regulated, respectively, in tumors of rats that received I3C, in comparison with the hemin-fed group. These findings reveal that the joint administration of I3C and syn enhanced the development of colon tumors induced by DMH in hemin-fed rats, while they potentially reduced ACF development when given alone.
Assuntos
Anticarcinógenos/administração & dosagem , Cocarcinogênese , Neoplasias do Colo/etiologia , Hemina/efeitos adversos , Indóis/administração & dosagem , Carne Vermelha/efeitos adversos , Simbióticos/administração & dosagem , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Células CACO-2 , Caderinas/genética , Carcinógenos/toxicidade , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Ensaio Cometa , Dimetilidrazinas/toxicidade , Progressão da Doença , Perfilação da Expressão Gênica , Hemina/administração & dosagem , Humanos , Peroxidação de Lipídeos , Masculino , Invasividade Neoplásica/genética , Proteínas do Tecido Nervoso/genética , Proteínas Proto-Oncogênicas c-raf/genética , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/genéticaRESUMO
Intestinal neuronal dysplasia type B is a controversial entity expressed by complex changes in the enteric nervous system. Diagnosis depends on rectal biopsy histopathology and diagnostic criteria, both qualitative and quantitative, have changed over time, hindering the diagnostic practice. We analyzed the morphological criteria for the histological diagnosis of intestinal neuronal dysplasia type B in a series of patients with intestinal neuronal dysplasia type B according to the 1990 Frankfurt Consensus criteria and verified the applicability of the numerical criteria proposed by Meier-Ruge et al in 2004 and 2006. Qualitative criteria adopted for the histological diagnosis of intestinal neuronal dysplasia type B included hyperplasia of the submucous plexus with hyperganglionosis and hypertrophy of the nerve trunks. Quantitative criteria considered more than 20% giant ganglia in the submucosa, with more than eight neurons each on 25 ganglia, and children aged over 1 year. Distal colon surgical specimens from 29 patients, aged 0-16 years, diagnosed with intestinal neuronal dysplasia type B were retrospectively analyzed using sections processed for conventional histology (H&E) and calretinin immunohistochemistry. Hyperplasia of the submucosal nerve plexi with hyperganglionosis and hypertrophy of the nerve trunks was observed in all cases. Ganglia with small, immature neurons were detected in the majority of cases. Quantitative analysis confirmed hyperganglionosis (mean number=10.7 neurons per ganglion) and hypertrophy of the nerve trunks (median=44.6 µm thickness). Neurons showed immunostaining for calretinin, but neuron counts in calretinin-stained sections were lower compared with H&E (P<0.01). No significant differences were verified between children aged under and over 1 year regarding hyperganglionosis (P=0.79), neuron counts (P=0.36), and immature ganglia (P=0.66). Only one patient met the numerical criteria proposed by Meier-Ruge et al in 2004 and 2006. In conclusion, the numerical criteria showed limited applicability when transposed to conventional histopathology. Children aged over 1 year presented very similar histological features of neuronal immaturity to younger children, questioning the need for an age criterion when diagnosing intestinal neuronal dysplasia type B.
Assuntos
Colo/patologia , Sistema Nervoso Entérico/patologia , Enteropatias/diagnóstico , Doenças do Sistema Nervoso/diagnóstico , Neurônios/patologia , Adolescente , Criança , Pré-Escolar , Feminino , Gânglios/patologia , Humanos , Lactente , Recém-Nascido , Enteropatias/patologia , Mucosa Intestinal/patologia , Masculino , Doenças do Sistema Nervoso/patologia , Estudos RetrospectivosRESUMO
The present study investigated whether maternal exposure to western style diet (WD) increases susceptibility to mammary carcinogenesis induced by N-methyl-N-nitrosourea (MNU) in female offspring. Pregnant female Sprague-Dawley rats received WD diet or control diet from gestational day 12 until postnatal day (PND) 21. At PND 21, female offspring received a single dose of MNU (50 mg/kg body weight) and were fed chow diet until PND 110. Mammary gland structures were assessed on whole-mount preparations in the offspring at PND 21, and tumor morphology was examined at PND 110. Immunohistochemical analysis for cell proliferation (PCNA), apoptosis (cleaved caspase-3) and estrogen receptor alpha (ER-α) was performed in mammary terminal end buds (TEBs) at PND 21, and PCNA, ER-α, and p63 analysis in mammary tumors at PND 110. Maternal WD intake induced a significant increase in the number of TEBs (P = 0.024) and in PCNA labeling index (P < 0.020) in the mammary glands at PND 21. Tumor multiplicity, tumor weight, and PCNA labeling indexes were significantly higher in the WD offspring than that of the control offspring (P < 0.05). These findings indicate that maternal western style diet potentially enhanced the development of mammary tumors induced by MNU in female offspring, possibly by affecting the mammary gland differentiation.
Assuntos
Dieta Ocidental/efeitos adversos , Neoplasias Mamárias Experimentais/patologia , Fenômenos Fisiológicos da Nutrição Materna , Animais , Apoptose , Carcinogênese , Caspase 3/genética , Caspase 3/metabolismo , Diferenciação Celular , Proliferação de Células , Suscetibilidade a Doenças/etiologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Metilnitrosoureia/toxicidade , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
Many difficulties occur during the evaluation of rectal biopsies for the diagnosis of Hirschsprung disease. We investigated whether the introduction of calretinin (CR) immunohistochemistry in a diagnostic panel could decrease the rate of inconclusive results. Data from 82 patients undergoing rectal biopsies before and after CR introduction were analyzed. Inconclusive results were obtained in 17 of 45 rectal biopsies (37.8%) in the series of cases before CR introduction and in 5 of 42 rectal biopsies (11.9%) in the series of cases after CR (P < 0.006). The inclusion of CR in the histopathologic panel may improve the diagnostic accuracy of Hirschsprung disease.
Assuntos
Calbindina 2/análise , Doença de Hirschsprung/diagnóstico , Reto/patologia , Adolescente , Adulto , Biópsia , Criança , Pré-Escolar , Doença de Hirschsprung/metabolismo , Doença de Hirschsprung/patologia , Humanos , Imuno-Histoquímica , Lactente , Adulto JovemRESUMO
Coffee has been inversely related to the incidence of human liver disease; however, whether caffeine is the component responsible for the beneficial effects of coffee remains controversial. This study evaluated the beneficial effects of coffee or caffeine in a medium-term bioassay for rat liver fibrosis/carcinogenesis induced by diethylnitrosamine (DEN) and carbon tetrachloride (CCl4). One week after the DEN injection, the groups started to receive conventional coffee, instant coffee or 0.1% caffeine ad libitum for 24 weeks. The groups receiving conventional coffee or caffeine presented a significant reduction in collagen content and mRNA expression of collagen I. The groups receiving instant coffee or caffeine had a significant reduction in the size and area of pre-neoplastic lesions and in the mean number of neoplastic lesions. A significant increase in liver bax protein levels was observed in the groups receiving instant coffee or caffeine as compared to the control group. These data indicate that the most pronounced hepatoprotective effect against fibrosis was observed in the groups receiving conventional coffee and 0.1% caffeine, and the greatest effects against liver carcinogenesis were detected in the groups receiving instant coffee and 0.1% caffeine.
Assuntos
Cafeína/farmacologia , Carcinogênese/efeitos dos fármacos , Café , Cirrose Hepática/prevenção & controle , Neoplasias Hepáticas Experimentais/prevenção & controle , Animais , Western Blotting , Colágeno/metabolismo , Glutationa Transferase/metabolismo , Neoplasias Hepáticas Experimentais/enzimologia , Masculino , Lesões Pré-Cancerosas/enzimologia , Lesões Pré-Cancerosas/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Retinopathy, a common complication of diabetes, is characterized by an unbalanced production of nitric oxide (NO), a process regulated by nitric oxide synthase (NOS). We hypothesized that retinopathy might stem from changes in the insulin receptor substrate (IRS)/PI3K/AKT pathway and/or expression of NOS isoforms. Thus, we analysed the morphology and apoptosis index in retinas of obese rats in whom insulin resistance had been induced by a high-fat diet (HFD). Immunoblotting analysis revealed that the retinal tissue of HFD rats had lower levels of AKT(1) , eNOS and nNOS protein than those of samples taken from control animals. Furthermore, immunohistochemical analyses indicated higher levels of iNOS and 4-hydroxynonenal and a larger number of apoptotic nuclei in HFD rats. Finally, both the inner and outer retinal layers of HFD rats were thinner than those in their control counterparts. When considered alongside previous results, these patterns suggest two major ways in which HFD might impact animals: direct activity of ingested fatty acids and/or via insulin-resistance-induced changes in intracellular pathways. We discuss these possibilities in further detail and advocate the use of this animal model for further understanding relationships between retinopathy, metabolic syndrome and type 2 diabetes.
Assuntos
Gorduras na Dieta/toxicidade , Proteínas do Olho/fisiologia , Obesidade/fisiopatologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Degeneração Retiniana/etiologia , Animais , Apoptose , Astrócitos/patologia , Glicemia/análise , Retinopatia Diabética , Modelos Animais de Doenças , Ácidos Graxos/sangue , Proteínas Substratos do Receptor de Insulina/fisiologia , Resistência à Insulina , Peroxidação de Lipídeos , Lipídeos/sangue , Fígado/patologia , Masculino , Óxido Nítrico Sintase Tipo I/fisiologia , Óxido Nítrico Sintase Tipo III/fisiologia , Obesidade/sangue , Obesidade/complicações , Fosfatidilinositol 3-Quinases/fisiologia , Ratos , Ratos Wistar , Retina/metabolismo , Retina/patologia , Degeneração Retiniana/sangue , Degeneração Retiniana/fisiopatologia , Transdução de SinaisRESUMO
Coffee intake has been inversely related to the incidence of liver diseases, although there are controversies on whether these beneficial effects on human health are because of caffeine or other specific components in this popular beverage. Thus, this study evaluated the protective effects of coffee or caffeine intake on liver injury induced by repeated thioacetamide (TAA) administration in male Wistar rats. Rats were randomized into five groups: one untreated group (G1) and four groups (G2-G5) treated with the hepatotoxicant TAA (200 mg/kg b.w., i.p.) twice a week for 8 weeks. Concomitantly, rats received tap water (G1 and G2), conventional coffee (G3), decaffeinated coffee (G4) or 0.1% caffeine (G5). After 8 weeks of treatment, rats were killed and blood and liver samples were collected. Conventional and decaffeinated coffee and caffeine intake significantly reduced serum levels of alanine aminotransferase (ALT) (p < 0.001) and oxidized glutathione (p < 0.05), fibrosis/inflammation scores (p < 0.001), collagen volume fraction (p < 0.01) and transforming growth factor ß-1 (TGF-ß1) protein expression (p ≤ 0.001) in the liver from TAA-treated groups. In addition, conventional coffee and caffeine intake significantly reduced proliferating cellular nuclear antigen (PCNA) S-phase indexes (p < 0.001), but only conventional coffee reduced cleaved caspase-3 indexes (p < 0.001), active metalloproteinase 2 (p ≤ 0.004) and the number of glutathione S-transferase placental form (GST-P)-positive preneoplastic lesions (p < 0.05) in the liver from TAA-treated groups. In conclusion, conventional coffee and 0.1% caffeine intake presented better beneficial effects than decaffeinated coffee against liver injury induced by TAA in male Wistar rats.
Assuntos
Cafeína/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Café/química , Fígado/efeitos dos fármacos , Tioacetamida/antagonistas & inibidores , Animais , Cafeína/administração & dosagem , Caspase 3/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/fisiopatologia , Colágeno/metabolismo , Manipulação de Alimentos , Glutationa/metabolismo , Fígado/metabolismo , Fígado/patologia , Fígado/fisiopatologia , Cirrose Hepática/etiologia , Cirrose Hepática/prevenção & controle , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Oxirredução , Lesões Pré-Cancerosas/etiologia , Lesões Pré-Cancerosas/prevenção & controle , Antígeno Nuclear de Célula em Proliferação/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Tioacetamida/toxicidade , Fator de Crescimento Transformador beta1/metabolismoRESUMO
Yacon (Smallanthus sonchifolius), a tuberous root native to the Andean region of South America, contains high concentration of fructans with potential for colon cancer prevention. This study investigated the potential beneficial of yacon intake on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats. After 4 weeks of DMH-initiation, groups were fed basal diet (G1 and G6) or basal diet containing dried extract of yacon root at 0.5% (G2), 1.0% (G3 and G5) or a synbiotic formulation (G4) (1.0% yacon plus Lactobacillus casei at 2.5 × 10(10)CFU per g diet) for 13 weeks. At week 20, a significant reduction in number and multiplicity of aberrant crypt foci (ACF) and in number of invasive adenocarcinomas was observed in the groups orally treated with 1.0% yacon (G3) or the synbiotic formulation (G4) (0.05
Assuntos
Asteraceae , Neoplasias do Colo/prevenção & controle , 1,2-Dimetilidrazina/toxicidade , Animais , Carcinógenos/toxicidade , Proliferação de Células , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Imuno-Histoquímica , Masculino , Ratos , Ratos WistarRESUMO
The noxious effects of dietary zinc deficiency (ZD) and deoxycholic bile acid (DCA) supplementation in the oesophagus were investigated. The additional influence of cigarette smoke and ethanol intake on the changes in the oesophageal mucosa induced by dietary ZD plus DCA was also assessed. Male C57BL/6 mice were allocated into four groups: Group 1 was fed control diet and groups 2-4 were fed ZD plus DCA diet. After 5 weeks, groups 3 and 4 were exposed to 10% ethanol intake or cigarette smoke for 15 weeks, respectively. All animals were euthanized at the end of week 20, and the oesophagus, lung, liver and colon were collected and analysed by conventional morphology. Cell proliferation was assessed in the oesophageal mucosa by Ki-67 immunohistochemistry and cyclooxygenase 2 (COX-2) protein by Western blotting. Dietary ZD plus DCA treatment induced mild hyperkeratosis and hyperplasia, increased cell proliferation index and COX-2 protein expression in the oesophagus, and intranuclear inclusion, karyocytomegaly and microvesicular fatty change in the liver. Cigarette smoke increased COX-2 protein expression in oesophageal mucosa and irregular enlargement of alveolus and alveolar ductal air spaces, while ethanol enhanced liver damage induced by ZD plus DCA diet. These findings indicate that dietary ZD plus DCA treatment during 20 weeks induces a pattern of chemical oesophageal injury but not Barrett's-like lesions.
Assuntos
Ácido Desoxicólico/administração & dosagem , Suplementos Nutricionais/efeitos adversos , Esôfago/patologia , Etanol/efeitos adversos , Fumaça/efeitos adversos , Zinco/deficiência , Animais , Western Blotting , Proliferação de Células/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Ácido Desoxicólico/efeitos adversos , Dieta , Esôfago/efeitos dos fármacos , Imuno-Histoquímica , Fígado/efeitos dos fármacos , Fígado/patologia , Hepatopatias Alcoólicas/etiologia , Hepatopatias Alcoólicas/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mucosa/efeitos dos fármacos , Mucosa/patologia , Nicotiana/efeitos adversos , Zinco/administração & dosagem , Zinco/efeitos adversosRESUMO
Lemongrass (Cymbopogon citratus Stapf) essential oil has been used worldwide because of its ethnobotanical and medicinal usefulness. Regarding its medicinal usefulness, the present study evaluated the beneficial effects of lemongrass essential oil (LGEO) oral treatment on cell proliferation and apoptosis events and on early development of hyperplastic lesions in the mammary gland, colon, and urinary bladder induced by N-methyl-N-nitrosourea (MNU) in female BALB/c mice. The animals were allocated into three groups: G1, treated with LGEO vehicle for 5 weeks (five times per week); G2, treated with LGEO vehicle as for G1 and MNU (two injections each of 30 mg/kg of body weight at weeks 3 and 5); and G3, treated with LGEO (five times each with 500 mg/kg of body weight per week) and MNU as for G2. Twenty-four hours after the last MNU application, all animals were euthanized, and mammary glands, colon, and urinary bladder were collected for histological and immunohistochemical analysis. LGEO oral treatment significantly changed the indexes of apoptosis and/or cellular proliferation for the tissues analyzed. In particular, the treatment reduced the incidence of hyperplastic lesions and increased apoptosis in mammary epithelial cells. This increment in the apoptosis response may be related to a favorable balance in Bcl-2/Bax immunoreactivity in mammary epithelial cells. These findings indicate that LGEO presented a protective role against early MNU-induced mammary gland alterations in BALB/c mice.
Assuntos
Carcinógenos/toxicidade , Cymbopogon/química , Metilnitrosoureia/toxicidade , Neoplasias/tratamento farmacológico , Óleos de Plantas/farmacologia , Terpenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Feminino , Humanos , Camundongos , Neoplasias/induzido quimicamente , Neoplasias/fisiopatologia , Especificidade de Órgãos/efeitos dos fármacosRESUMO
The intestinal population of Escherichia coli is increased in patients with inflammatory bowel disease (IBD), but the reason for this elevation, the particular features of these bacteria and their potential role in the pathogenesis of the disease are not known. The present study was undertaken to investigate the adherence abilities and some virulence properties of a collection of 131 E. coli isolates cultured from rectal biopsies of 23 subjects diagnosed with ulcerative colitis (UC), 8 with Crohn's disease (CD) and 23 control patients from southern Brazil. The adherence abilities of the bacteria were investigated in vitro, using HEp-2 epithelial cells in assays of 3 and 6h of bacteria-cell contact. The isolates were screened by PCR with primers for the following virulence genetic markers: plasmid of aggregative adhesion (pAA) and the aggregative adherence fimbriae R (aggR), E. coli attaching and effacing (eae), invasion-associated locus (ial), invasion plasmid antigen H (ipaH) and Shiga citotoxin-encoding (stx) genes. HEp-2 cells aggregative adherent E. coli strains, as detected in the 3h adherence assay, were found in 14/23 (60.9%) patients with UC, 7/8 (87.5%) with CD and in 7/23 (30.4%) controls (p=0.011). Virulence genetic markers were detected in strains of 9 patients with UC (39.1%), but in none of CD or control group. Two of these UC patients had strains harboring both pAA and aggR, one had strains positive for aggR, four had strains positive for eae and two had strains positive for stx. These results suggest that the augmented population of E. coli on the rectal mucosa of IBD patients, particularly of those diagnosed with UC, is mostly comprised of aggregative adherent strains, some of which possessing classical virulence markers of E. coli.
Assuntos
Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Escherichia coli/patogenicidade , Fímbrias Bacterianas/genética , Mucosa Intestinal/microbiologia , Metagenoma , Adulto , Aderência Bacteriana , Brasil/epidemiologia , Linhagem Celular , Colite Ulcerativa/microbiologia , Doença de Crohn/microbiologia , Células Epiteliais/metabolismo , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Feminino , Marcadores Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Plasmídeos , Prevalência , Transativadores/genética , Transativadores/metabolismo , VirulênciaRESUMO
This study investigated the protective effect of oral treatment with lemongrass (Cymbopogon citratus STAPF) essential oil (LGEO) on leukocyte DNA damage induced by N-methyl-N-nitrosurea (MNU). Also, the anticarcinogenic activity of LGEO was investigated in a multi-organ carcinogenesis bioassay induced by 7,12-dimethylbenz(a)antracene, 1,2-dimethylhydrazine and N-butyl-N-(4-hydroxibuthyl)nitrosamine in Balb/C female Balb/c mice (DDB-initiated mice). In the short-term study, the animals were allocated into three groups: vehicle group (negative control), MNU group (positive control) and LGEO 500 mg kg⻹ (five times per week for 5 weeks) plus MNU group (test group). Blood samples were collected to analyze leukocyte DNA damage by comet assay 4 h after each MNU application at the end of weeks 3 and 5. The LGEO 500 mg kg⻹ treated group showed significantly lower (P < 0.01) leukocyte DNA damage than its respective positive group exposed to MNU alone at week 3. In the medium-term study, DDB-initiated mice were allocated into three groups: vehicle group (positive control) and LGEO 125 or 500 mg kg⻹ (five times per week for 6 weeks; test groups). At week 20, all animals were euthanized and mammary glands, colon and urinary bladder were processed for histopathological analyses for detection of preneoplastic and neoplastic lesions. A slight non-significant effect of treatment with LGEO 500 mg kg⻹ in reducing development of alveolar and ductal mammary hyperplasia was found (P = 0.075). Our findings indicate that lemongrass essential oil provided protective action against MNU-induced DNA damage and a potential anticarcinogenic activity against mammary carcinogenesis in DDB-initiated female Balb/C mice.
Assuntos
Carcinogênese/efeitos dos fármacos , Carcinógenos/toxicidade , Dano ao DNA/efeitos dos fármacos , Óleos de Plantas/farmacologia , Terpenos/farmacologia , Animais , Testes de Carcinogenicidade , Colo/efeitos dos fármacos , Colo/metabolismo , Ensaio Cometa , Determinação de Ponto Final , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Metilnitrosoureia/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/patologiaRESUMO
OBJECTIVE: We investigated the effects of high-fat diet-induced obesity on vascular proinflammatory factors and oxidative stress on endothelium-dependent relaxation of the aorta. METHODS: Female Swiss mice were submitted to a high-fat diet for 16 weeks. At the end of the experimental period, we evaluated blood pressure, relaxation in response to acetylcholine in aortic rings in the absence and the presence of the superoxide anion scavenger, superoxide dismutase (SOD, 150 U/ml), and the nuclear factor (NF)-κB inhibitor, sodium salicylate (5 mmol/l). Aortic protein expression of endothelial nitric oxide synthase, Cu/Zn-SOD, NF-κB, IκB-α, and proinflammatory cytokines were also evaluated. RESULTS: Obese mice presented higher systolic and diastolic blood pressure than control mice (P < 0.05). The relaxation of aortas to acetylcholine, but not to sodium nitroprusside, was significantly decreased in obese mice and was corrected by both SOD and sodium salicylate (P < 0.05). The protein expression of endothelial nitric oxide synthase and Cu/Zn-SOD was significantly decreased in aorta from obese mice (P < 0.05). Total p65 NF-κB subunit protein expression was not affected by obesity, but the protein expression of NF-κB inhibitor IκB-α was lower in aorta from obese mice (P < 0.05). There were no significant differences in the interleukin (IL)-1ß and IL-6 protein expression between groups. In contrast, the expression of TNF-α was significantly increased in aortas from obese mice. CONCLUSION: Our results suggest that the reduced antioxidant defense and the local NF-κB pathway play an important role in the impairment of endothelium-dependent relaxation in aorta from obese mice.
Assuntos
Gorduras na Dieta/efeitos adversos , Endotélio Vascular/fisiopatologia , Inflamação/fisiopatologia , Obesidade/etiologia , Obesidade/fisiopatologia , Estresse Oxidativo/fisiologia , Acetilcolina/farmacologia , Animais , Aorta/efeitos dos fármacos , Aorta/fisiopatologia , Pressão Sanguínea/fisiologia , Modelos Animais de Doenças , Endotélio Vascular/efeitos dos fármacos , Feminino , Camundongos , NF-kappa B/metabolismo , Nitroprussiato/farmacologia , Obesidade/metabolismo , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
This study evaluated whether a synergy exists for the combined treatment with lycopene and synbiotic on early biomarkers of colon carcinogenesis. Male Wistar rats received a diet containing 300 mg/kg of lycopene and/or synbiotic (Bifidobacterium lactisplus oligofructose/inulin) or their combination 2 weeks before and during carcinogen treatment with 1,2-dimethylhydrazine (DMH). Twenty-four hours after the last DMH application, the colons were processed for immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), p53 protein, hematoxylin-eosin staining for apoptosis analysis and genotoxicity of fecal water by comet assay. Eight weeks after the last DMH application, the colons were analyzed for development of classical aberrant crypt foci (ACF) and mucin-negative ACF. Treatment with lycopene, synbiotic or their combination significantly increased apoptosis, reduced the PCNA and p53 labeling indexes and the development of classical ACF and mucin-negative ACF. Furthermore, a lower genotoxicity of fecal water was also detected in the groups treated with the chemopreventive agents. An additive/synergistic effect of the combined treatment with lycopene/synbiotic was observed only for the fecal water genotoxicity and mucin-negative ACF parameters. These results indicate that an additive/synergistic of the combination of chemopreventive agents on the initiation phase of colon carcinogenesis can be detected using selective early biomarkers.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Bifidobacterium/química , Carotenoides/farmacologia , Neoplasias do Colo/patologia , Neoplasias do Colo/prevenção & controle , Oligossacarídeos/farmacologia , 1,2-Dimetilidrazina , Animais , Biomarcadores Tumorais , Peso Corporal/efeitos dos fármacos , Carcinógenos , Neoplasias do Colo/metabolismo , Ensaio Cometa , Dano ao DNA , Ingestão de Alimentos/efeitos dos fármacos , Fezes/química , Imuno-Histoquímica , Mucosa Intestinal/patologia , Licopeno , Masculino , Mucinas/metabolismo , Oligossacarídeos/química , Celulas de Paneth/patologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Ratos Wistar , Proteína Supressora de Tumor p53/metabolismoRESUMO
Ginkgo biloba (EGb) has been proposed as a promising candidate for cancer chemoprevention and has shown protective effects on the liver against chemically induced oxidative injury and fibrosis. The potential beneficial effects of EGb were investigated in two rat liver carcinogenesis bioassays induced by diethylnitrosamine (DEN). In a short-term study for anti-initiating screening, male Wistar rats were fed a basal diet or supplemented diet with 500 or 1000 ppm EGb and initiated 14 days later with a single dose of DEN (100 mg/kg i.p.). The respective groups were killed 24h or 2 weeks after DEN-initiation. Liver samples were collected for the analysis of proliferating cell nuclear antigen (PCNA), transforming growth factor alpha (TGF-alpha), p53, apoptosis and induction of single hepatocytes and minifoci positive for the enzyme glutathione S-transferase P-form (GST-P). In a medium-term study for anti-promoting screening, the animals received a single dose of DEN (200 mg/kg i.p.) and, 2 weeks later, were fed a basal diet or supplemented diet with 500 or 1000 ppm EGb for 6 weeks. All animals underwent 70% partial hepatectomy (PH) at week 3 and killed at week 8. Liver samples were collected to analyze development of preneoplastic foci of altered hepatocytes (FAH) expressing GST-P. In the short-term study, pretreatment of rats with 1000 ppm EGb significantly reduced the rates of cell proliferation, apoptosis and p53, TGF-alpha immunoreactivity and the number of GST-P-positive hepatocytes. In the medium-term study, EGb treatment during the post-initiation stage failed to reduce the development of DEN-induced GST-P-positive foci. Thus, EGb presented inhibitory actions during initiation but not promotion of rat liver carcinogenesis induced by DEN.
Assuntos
Ginkgo biloba/química , Neoplasias Hepáticas Experimentais/prevenção & controle , Extratos Vegetais/administração & dosagem , Animais , Bioensaio , Carcinógenos/toxicidade , Dietilnitrosamina/toxicidade , Glutationa/metabolismo , Neoplasias Hepáticas Experimentais/induzido quimicamente , Masculino , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Ratos Wistar , Fator de Crescimento Transformador alfa/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
The aim of this study was to evaluate the relationship among oxidative DNA damage, density of Helicobacter pylori and the relevance of cagA, vacA and iceA genotypes of H. pylori. Gastric epithelial cells were isolated from 24 uninfected patients, 42 H. pylori infected patients with gastritis, and 61 patients with gastric cancer. Oxidative DNA damage was analyzed by the Comet assay, the density of H. pylori was measured by real-time polymerase chain reaction (PCR), and allelic variants of cagA, vacA and iceA were identified using the PCR. Infected patients by Helicobacter pylori cagA(+), vacAs1 m1 and iceA1 genotype showed higher levels of oxidative DNA damage than infected patients with H. pylori cagA(-), vacAs2 m2 and iceA2 genotypes and uninfected patients. Density of H. pylori did not influence oxidative DNA damage. Our results indicate that H. pylori genotype is more relevant than density for oxidative DNA damage.
Assuntos
Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Dano ao DNA/genética , DNA Bacteriano/genética , Mucosa Gástrica/patologia , Helicobacter pylori/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/imunologia , Biópsia , Contagem de Células , Ensaio Cometa , Feminino , Mucosa Gástrica/microbiologia , Genótipo , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/imunologia , Helicobacter pylori/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos ProspectivosRESUMO
INTRODUÇÃO: A recidiva local no câncer colorretal tem como principal causa o implante de células tumorais nas anastomoses. 11-15 Dessa maneira, lavagem química do lúmen intestinal é preconizada para evitar tanto o implante quanto à recidiva local. 11-28 Em estudos prévios constatamos que a solução bicarbonatada de ácido acetilsalicílico tem efeitos citolíticos e anti-tumorais in-vitro.31 OBJETIVOS: Avaliar a toxicidade da solução de aspirina na mucosa colônica de coelhos com o objetivo de usá-la no preparo intestinal de portadores de câncer colorretal. MATERIAIS E MÉTODOS: Foram utilizados 20 coelhos. Um clampe vascular foi colocado acima do cólon sigmóide. Os animais foram submetidos a um enema com 50 ml da solução de aspirina ou soro fisiológico de acordo com o grupo. Os animais foram sacrificados ao término do procedimento ou tardiamente de acordo com o grupo. RESULTADOS: A solução de aspirina não altera a mucosa colônica de coelhos. CONCLUSÃO: O uso da solução bicarbonatada de ácido acetilsalicílico no preparo intestinal de portadores de câncer colorretal é clinicamente possível.
BACKGROUND: The implantation of viable exfoliated intraluminal tumour cells is the major cause of local recurrence in colorectal cancer. 11-28 Therefore, the bowel lumen wash with a tumoricidal agent has been recommended. 11-28 In previous study we observe that acetylsalicylic acid solution cause neoplastic cell death in vitro.31 PURPOSE: Assess the local effect of acetylsalicylic acid solution on the colonic mucosa of rabbits, in order to use this agent in the bowel lumen wash. METHODS: 20 rabbits were used. A vascular clamp was placed on the distal colon, followed by the instillation per rectum of 50 ml of acetylsalicylic acid solution or saline solution, according to the group. The euthanasia was performed immediately or later according to the group. RESULTS: The acetylsalicylic acid solution doesn't cause any injury on the colonic mucosa of rabbits. Conclusion: The use of acetylsalicylic acid solution in the bowel lumen wash seems clinically feasible.