RESUMO
There is continuous and growing interest in research into new alternatives to standard biomarkers to detect and follow-up disease, reducing physical and psychological stress in patients needing regular and invasive medical examinations for the evaluation of pathologies, including inflammatory bowel diseases (IBD). Saliva is one of the most promising body fluids in the research of new biomarkers, thanks to the large number of molecules it contains. Many molecules present in saliva are often directly correlated to their concentration in the blood but may be affected by the condition of the oral cavity. This means that a careful selection of a specific biomarker is required for each pathology, especially pathologies such as IBD, which may induce inflammation in the oral cavity. Here, we analyze the currently used and the proposed new salivary biomarkers (i.e., calprotectin, cytokines, IgA, cortisol, and oxidative stress markers) for the detection and follow-up of the main subtypes of IBD, known as ulcerative colitis and Crohn's disease.
Assuntos
Colite Ulcerativa/metabolismo , Doença de Crohn/metabolismo , Estresse Oxidativo , Saliva/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Biomarcadores/metabolismo , Colite Ulcerativa/diagnóstico , Doença de Crohn/diagnóstico , HumanosRESUMO
Olive leaves represent a quantitatively significant by-product of agroindustry. They are rich in phenols, mainly oleuropein, which can be hydrolyzed into several bioactive compounds, including hydroxytyrosol. In this study, water extract from olive leaves 'Biancolilla' was analyzed for polyphenol profile, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and protective effect on differentiated Caco-2 cells. The efficacy of two enzymatic treatments in promoting the release of bioactive phenols was investigated: a) enzymatic extract from Wickerhamomyces anomalus, characterized by ß-glucosidase and esterase activities; b) commercial ß-glucosidase. Composition and bioactivity of the resulting extracts were compared. The results showed that the yeast-treated extract presented hydroxytyrosol content and DPPH radical scavenging activity comparable to those obtained using commercial ß-glucosidase; however, it was showed the additional presence of hydroxycinnamic acids. In experiments on Caco-2 cells, the leaf extracts promoted the recovery of cell membrane barrier at different minimum effective concentrations. The high specificity of W. anomalus enzymatic extract may represent an effective tool for the release of bioactive phenols from olive by-products.
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Iridoides/análise , Olea/química , Fenóis/análise , Álcool Feniletílico/análogos & derivados , Polifenóis/análise , Saccharomycetales/enzimologia , Biotransformação , Células CACO-2 , Ácidos Cumáricos/análise , Ácidos Cumáricos/metabolismo , Esterases/metabolismo , Humanos , Hidrólise , Glucosídeos Iridoides , Iridoides/metabolismo , Fenóis/metabolismo , Álcool Feniletílico/análise , Álcool Feniletílico/metabolismo , Folhas de Planta/química , Polifenóis/metabolismo , beta-Glucosidase/metabolismoRESUMO
BACKGROUND: The role of Lactobacillus cell wall components in the protection against pathogen infection in the gut is still largely unexplored. We have previously shown that L. amylovorus DSM 16698T is able to reduce the enterotoxigenic F4+ Escherichia coli (ETEC) adhesion and prevent the pathogen-induced membrane barrier disruption through the regulation of IL-10 and IL-8 expression in intestinal cells. We have also demonstrated that L. amylovorus DSM 16698T protects host cells through the inhibition of NF-kB signaling. In the present study, we investigated the role of L. amylovorus DSM 16698T cell wall components in the protection against F4+ETEC infection using the intestinal Caco-2 cell line. METHODS: Purified cell wall fragments (CWF) from L. amylovorus DSM 16698T were used either as such (uncoated, U-CWF) or coated with S-layer proteins (S-CWF). Differentiated Caco-2/TC7 cells on Transwell filters were infected with F4+ETEC, treated with S-CWF or U-CWF, co-treated with S-CWF or U-CWF and F4+ETEC for 2.5 h, or pre-treated with S-CWF or U-CWF for 1 h before F4+ETEC addition. Tight junction (TJ) and adherens junction (AJ) proteins were analyzed by immunofluorescence and Western blot. Membrane permeability was determined by phenol red passage. Phosphorylated p65-NF-kB was measured by Western blot. RESULTS: We showed that both the pre-treatment with S-CWF and the co- treatment of S-CWF with the pathogen protected the cells from F4+ETEC induced TJ and AJ injury, increased membrane permeability and activation of NF-kB expression. Moreover, the U-CWF pre-treatment, but not the co-treatment with F4+ETEC, inhibited membrane damage and prevented NF-kB activation. CONCLUSIONS: The results indicate that the various components of L. amylovorus DSM 16698T cell wall may counteract the damage caused by F4+ETEC through different mechanisms. S-layer proteins are essential for maintaining membrane barrier function and for mounting an anti-inflammatory response against F4+ETEC infection. U-CWF are not able to defend the cells when they are infected with F4+ETEC but may activate protective mechanisms before pathogen infection.
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Lifestyle habits, host gene repertoire, and alterations in the intestinal microbiota concur to the development of obesity. A great deal of research has recently been focused on investigating the role gut microbiota plays in the pathogenesis of metabolic dysfunctions and increased adiposity. Altered microbiota can affect host physiology through several pathways, including enhanced energy harvest, and perturbations in immunity, metabolic signaling, and inflammatory pathways. A broad range of "omics" technologies is now available to help decipher the interactions between the host and the gut microbiota at detailed genetic and functional levels. In particular, metabolomics--the comprehensive analysis of metabolite composition of biological fluids and tissues--could provide breakthrough insights into the links among the gut microbiota, host genetic repertoire, and diet during the development and progression of obesity. Here, we briefly review the most insightful findings on the involvement of gut microbiota in the pathogenesis of obesity. We also discuss how metabolomic approaches based on nuclear magnetic resonance spectroscopy could help understand the activity of gut microbiota in relation to obesity, and assess the effects of gut microbiota modulation in the treatment of this condition.
Assuntos
Bactérias/metabolismo , Intestinos/microbiologia , Espectroscopia de Ressonância Magnética , Metabolômica/métodos , Obesidade/microbiologia , Adiposidade , Animais , Dieta/efeitos adversos , Interações Hospedeiro-Patógeno , Humanos , Microbiota , Obesidade/fisiopatologia , Obesidade/terapia , Prebióticos , ProbióticosRESUMO
Age-related dysbioses of intestinal microbiota and decline in the overall metabolic homeostasis are frequently found in the elderly. Probiotic supplementation may represent a way to prevent or reduce the senescence-associated metabolic disorders. The present study evaluated the metabolic impact of Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 supplementation in relation to age by analyzing urine and feces metabolic profiles using (1)H-nuclear magnetic resonance spectroscopy and multivariate analysis. Adult (3 mo old) and aged (16 mo old) mice received an oral supplementation of the 2 probiotics (1 × 10(9) colony-forming units/d each) or phosphate buffered saline (control) daily for 30 d. Urine and feces were collected for 48 h before the end of the study. Partial least squares-discriminant analysis showed that the urinary discriminant metabolites for the probiotic treatment included higher dimethylglycine in adult and aged mice, lower sarcosine and nicotinate in adult mice, higher N-methylnicotinamide in adult mice and lower N-methylnicotinamide in aged mice compared with their controls. These results indicate a probiotic-induced modulation of homocysteine and NAD metabolism pathways, which have important implications because these pathways are involved in essential cellular processes that can be altered in senescence. The probiotic supplementation also modified the fecal metabolic profiles, inducing in both adult and aged mice higher 4-hydroxyphenylacetate and lower xylose in treated mice compared with their control mice, whereas valerate was greater in treated adult mice and lower in treated aged mice compared with their controls. The ANOVA simultaneous component analysis on urinary and fecal metabolic profiling showed an age × treatment interaction (P < 0.05), confirming the age-related modulation of the metabolic response to probiotic supplementation. The results suggest that L. acidophilus and B. lactis may prevent or reduce age-related metabolic dysfunction.
Assuntos
Envelhecimento/metabolismo , Bifidobacterium , Intestinos/microbiologia , Lactobacillus acidophilus , Metaboloma , Probióticos , Fatores Etários , Envelhecimento/urina , Animais , Fezes , Homocisteína/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Masculino , Redes e Vias Metabólicas , Camundongos , Camundongos Endogâmicos BALB C , NAD/metabolismo , Niacina/urina , Niacinamida/análogos & derivados , Niacinamida/urina , Ácidos Pentanoicos/metabolismo , Fenilacetatos/metabolismo , Sarcosina/análogos & derivados , Sarcosina/urina , Xilose/metabolismoRESUMO
The remarkable biological activities of oregano essential oils (EOs) have recently prompted a host of studies aimed at exploring their potential innovative applications in the food and pharmaceutical industries. The chemical composition and biological activities of EOs from two Origanum vulgare genotypes, widely cultivated in Sicily and not previously studied for their biological properties, were characterized. Plants of the two genotypes, belonging to the carvacrol (CAR) and thymol (THY) chemotypes and grown in different cultivation environments, were considered for this study. The chemical profiles, including the determination of enantiomeric distribution, of the EOs, obtained by hydrodistillation from dried leaves and flowers, were investigated by GC-MS. Biological activity was evaluated as antimicrobial properties against different pathogen indicator strains, while intestinal barrier integrity, reduction in pathogen adhesion and anti-inflammatory actions were assayed in the intestinal Caco-2 cell line. The chemical profile of the CAR genotype was less complex and characterized by higher levels of the most active compound, i.e., carvacrol, when compared to the THY genotype. The enantiomeric distribution of chiral constituents did not vary across genotypes, while being markedly different from that observed in Origanum vulgare genotypes from other geographical origins. In general, all EOs showed high antimicrobial activity, both in vitro and in a food matrix challenge test. Representative EOs from the two genotypes resulted not altering epithelial monolayer sealing only for concentrations lower than 0.02%, were able to reduce the adhesion of selected pathogens, but did not exert relevant anti-inflammatory effects. These results suggest their potential use as control agents against a wide spectrum of foodborne pathogens.
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Nowadays, research on plant extracts has attracted increasing interest. The aim of this study was to compare phenolic profile, vitamin C, and carotenoid content, as well as the biological activities of five different rose species, including Rosa canina, R. corymbifera, R. micrantha, R. rubiginosa, and R. rugosa. These species had different morphological characteristics, with R. rugosa showing higher size of flower petals and higher weight of hips. The highest vitamin C content was found in hip extracts of R. rubiginosa and R. rugosa, which also showed the highest carotenoid amount. R. corymbifera showed the highest phenolic content. No significant antimicrobial activity of extracts containing phenolic compounds against different indicator strains could be detected. Cell monolayer integrity was not affected by treatments with the above-mentioned extracts of R. canina, R. micrantha, and R. rugosa at different concentrations for up to 24 h, while those of R. rubiginosa and R. corymbifera affected intestinal permeability at the highest concentration tested. The partial least squares regression analysis generated a predictive model correlating phenolic compounds with cell monolayer integrity, suggesting a relevant role for catechin, quercitrin, and p-coumaric acid. In conclusion, this study highlights how rose hips belonging to different species can have a diverse phenolic profile, differently influencing intestinal monolayer integrity.
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Probiotics may modulate the host immune response by mechanisms not yet fully understood. We evaluated the modulation of intestinal and systemic antigen-specific immune response by Lactobacillus rhamnosus GG (LGG) or Bifidobacterium animalis MB5 in tolerized and immunized rats. Three groups of rats received orally LGG, B. animalis, or PBS (control) for 28 d. Each group was divided into two subgroups of tolerized or immunized rats receiving orally ovalbumin (OVA; 7 mg) or PBS on d 7, 9, and 11. All rats were immunized with OVA (300 µg) on d 14 and 21. In tolerized rats, the OVA-induced proliferative response of mesenteric lymph nodes (MLN) and spleen cells did not differ from control, indicating that the two probiotics maintained the tolerance. LGG and B. animalis in immunized rats reduced the OVA-induced proliferative response in MLN (P < 0.01) but not in spleen, whereas the proliferative response to anti-CD3 and concanavalin A of MLN and spleen cells as well as the delayed-type hypersensitivity reaction were not affected by probiotic treatment, indicating OVA-specific hyporesponsiveness restricted to intestinal immunity. This hyporesponsiveness was associated with CD4+CD25+Foxp3+ T cell expansion (P < 0.01) and increased IL-10 and TGFß after LGG (P < 0.05), and increased apoptosis after B. animalis (P < 0.001) in MLN. In conclusion, we report a novel activity of LGG and B. animalis in inducing OVA-specific hyporesponsiveness in MLN of OVA-immunized rats that can be useful for a therapeutic strategy to prevent undesirable reactions to immunogenic antigens in the gut.
Assuntos
Antígenos/imunologia , Bifidobacterium/fisiologia , Intestinos/imunologia , Lacticaseibacillus rhamnosus/fisiologia , Ovalbumina/imunologia , Probióticos/farmacologia , Animais , Especificidade de Anticorpos , Apoptose , Bifidobacterium/classificação , Regulação da Expressão Gênica , Interleucina-10/genética , Interleucina-10/metabolismo , Lacticaseibacillus rhamnosus/classificação , Masculino , Ratos , Ratos Sprague-Dawley , Linfócitos T Reguladores/fisiologia , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismoRESUMO
BACKGROUND: Studies on health effects of organic (ORG) products are still limited and often contradictory. We have investigated the impact of ORG and conventional (CV) carrots from two consecutive harvest years on mouse peripheral and intestinal immunity. RESULTS: Danish carrots (Bolero variety) were grown in three ORG (O1, O2 and O3) and one CV cropping system (D-CV). Italian carrots (Maestro and Excelso varieties) were grown in one ORG and one CV field for each variety. Immune phenotypes of blood, spleen and intestinal lymphocytes, and cytokine serum levels were analyzed in mice fed the different carrots for 30 days. Principal component analysis (PCA) was performed in mice fed the Danish carrots. The consumption of the 'more organic' O2 and O3 carrots induced some changes in lymphocyte populations, including an increase in regulatory T cells. In Italian carrots more differences between ORG and CV were observed in the first as compared to the second year. No relevant differences were observed in cytokine secretion. PCA showed a clear separation among mice fed the O1, O2, O3 and D-CV carrots. CONCLUSIONS: Although a great variability was observed between the two years, an immune stimulation was found after the ORG carrot consumption.
Assuntos
Daucus carota/crescimento & desenvolvimento , Alimentos Orgânicos , Imunidade Celular , Imunidade nas Mucosas , Imunomodulação , Intestinos/imunologia , Raízes de Plantas/crescimento & desenvolvimento , Animais , Colo/citologia , Colo/imunologia , Produtos Agrícolas/crescimento & desenvolvimento , Citocinas/sangue , Citocinas/metabolismo , Dinamarca , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Itália , Contagem de Linfócitos , Camundongos , Camundongos Endogâmicos BALB C , Reprodutibilidade dos Testes , Baço/citologia , Baço/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismoRESUMO
The non-professional sport environment is a grey zone not as widely assessed as that of elite athletes. The purpose of this research was to investigate the dietary supplementation habits and the nutrition knowledge on sport (NKS) in a sample of gym users. The level of adequacy of NKS was set at ≥60% of correct answers. Almost half (46.4%) of respondents stated they used food supplements, in particular multivitamins (31.0%), amino acid pills (29.5%), minerals (29.1%), and protein powders (28.7%). Supplements were used to increase muscle mass (36.9%) and to repair muscle (35.1%). Gym trainers were the preferred source of information on the use of supplements, especially in males (84%). The NKS correct response rate was 57.1% and the proportion of respondents with a sufficient level of NKS was 47.3%. The prevalence of correct answers was highest in males (61.5%) and for respondents with the highest educational attainment levels (44.5% and 53%). This study demonstrated that non-professional sportsmen do not have sufficient knowledge of nutrition and that the gym environment does not facilitate the circulation of the correct information on the role of supplementation. Considering the importance of nutrition for sportsmen, it is necessary to put in place actions aimed at increasing the knowledge of nutrition of gym users and their trainers.
Assuntos
Academias de Ginástica , Esportes , Suplementos Nutricionais , Exercício Físico , Humanos , Masculino , Inquéritos e QuestionáriosRESUMO
The biological activities of dietary bioactive polysaccharides have been largely explored. Studies on the immunomodulating effects of oligosaccharides and polysaccharides have shown that they are able to modulate innate immunity. Prebiotics are a class of poorly digested carbohydrates that are mainly produced from dietary fibers, which are carbohydrate polymers with ten or more monomeric units as defined by the Codex Alimentarius Commission in 2009. Considering the capacity of prebiotics in reducing gut inflammation, the aim of this study was to investigate the anti-inflammatory activity of galactooligosaccharide (Bimuno® GOS) in an in vitro model of ulcerative colitis (UC)-like inflamed intestinal cells. Differentiated Caco-2 cells were exposed to 2 % dextran-sulfate-sodium salt (DSS) to induce inflammation, and then with different concentrations of Bimuno GOS (1-1,000 µg/ml). Cell monolayer permeability, tight- and adherent junction protein distribution, pro-inflammatory cytokine secretion, and NF-kB cascade were assessed. Bimuno GOS at different concentrations, while not affecting cell monolayer permeability, was shown to counteract UC-like intestinal inflammatory responses and damages induced by DSS. Indeed, Bimuno GOS was able to counteract the detrimental effects of DSS on cell permeability, determined by transepithelial electrical resistance, phenol red apparent permeability, and tight- and adherent junction protein distribution. Furthermore, Bimuno GOS inhibited the DSS-induced NF-kB nuclear translocation and pro-inflammatory cytokine secretion. Further analyses showed that Bimuno GOS was able to revert the expression levels of most of the proteins involved in the NF-kB cascade to control levels. Thus, the prebiotic Bimuno GOS can be a safe and effective way to modulate the gut inflammatory state through NF-kB pathway modulation, and could possibly further improve efficacy in inducing remission of UC.
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Inflammatory bowel diseases, namely Crohn's disease and ulcerative colitis, are currently considered multifactorial pathologies in which various combined environmental factors act on genetic background, giving rise to chronic inflammation of the gastrointestinal tract. Ulcerative colitis is an inflammation of the colon caused by a dysregulated immune response to host intestinal microbiota in genetically susceptible subjects. Ulcerative colitis has a strong impact on patients' quality of life, as well as high costs for the health-care system. A great interest on the role of intestinal microbiota modulation in ulcerative colitis is emerging. Several studies have shown an improvement of inflammatory markers and symptoms in ulcerative colitis patients through treatments with probiotics and prebiotics separately. Despite the low number of studies on the treatment of ulcerative colitis by specific strains of probiotics plus selected prebiotics, i.e. synbiotics, the results are promising, even if discordant. The mechanism of action in synbiotics supplementation is still unclear and needs more investigation, although there is a large number of data indicating that the synergism between probiotics and prebiotics favours the survival and implantation of probiotics into the gastrointestinal tract with beneficial effects on human health by modulating the inflammatory response and gut microbiota composition. The aim of this minireview is to describe the main in vitro, animal and human studies performed up to now, that have used synbiotics to treat ulcerative colitis, and to highlight limitations and future perspectives.
Assuntos
Colite Ulcerativa/terapia , Microbioma Gastrointestinal , Simbióticos/administração & dosagem , Animais , Colite Ulcerativa/microbiologia , Colite Ulcerativa/fisiopatologia , Custos de Cuidados de Saúde , Humanos , Qualidade de VidaRESUMO
Ageing is often characterised by nutritional deficiencies and functional alterations of the digestive and immune system. The aim of the present study was to analyse the impact of consumption of conventional milk with A1/A2 beta-casein, compared to milk containing only the A2 beta-casein variant, characterised by a protein profile favouring gut health. Twenty-four ageing Balb-c mice (20 months old) were fed for 4 weeks, with either a control diet (CTRL), a diet supplemented with bovine milk containing A1/A2 beta-casein (A1A2) or a diet containing A2/A2 beta-casein (A2A2). Lymphocyte subpopulations, enzymatic activities, cytokine secretion, gut morphology and histopathological alterations were measured in different gut segments, while short-chain fatty acids (SCFAs) content and microbiota composition were evaluated in faecal samples. The A2A2 group showed higher content of faecal SCFAs (in particular, isobutyrate) of intestinal CD4+ and CD19+ lymphocytes in the intraepithelial compartment and improved villi tropism. The A1A2 group showed higher percentages of intestinal TCRγδ+ lymphocytes. Faecal microbiota identified Deferribacteriaceae and Desulfovibrionaceae as the most discriminant families for the A2A2 group, while Ruminococcaceae were associated to the A1A2 group. Taken together, these results suggest a positive role of milk, in particular when containing exclusively A2 beta-casein, on gut immunology and morphology of an ageing mice model.
Assuntos
Caseínas/administração & dosagem , Caseínas/farmacologia , Suplementos Nutricionais , Microbioma Gastrointestinal , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Leite , Fenômenos Fisiológicos da Nutrição/fisiologia , Animais , Caseínas/classificação , Citocinas/metabolismo , Ácidos Graxos Voláteis/metabolismo , Feminino , Inflamação , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Linfócitos/imunologia , Masculino , Camundongos Endogâmicos BALB C , Leite/química , Modelos AnimaisRESUMO
A functional bread tailored for the needs of the aging population was baked by substituting 24% of wheat flour with red lentil flour and compared with wheat bread. Its nutritional profile was assessed by analysing proteins, amino acids, lipids, soluble and insoluble dietary fibre, resistant starch, total polyphenols, lignans and the antioxidant capacity (FRAP assay). The wheat-lentil bread had 30% more proteins than wheat bread (8.3%, as is), a more balanced amino acids composition, an almost double mineral (0.63%, as is) as well as total dietary fibre content (4.6%, as is), double the amount of polyphenols (939.1 mg GAE/100g on dry matter, d.m.), higher amounts and variety of lignans, and more than double the antioxidant capacity (71.6 µmoL/g d.m.). The in vivo effect of 60 days bread consumption on the immune response was studied by means of a murine model of elderly mice. Serum cytokines and intraepithelial lymphocyte immunophenotype from the mice intestine were analysed as markers of systemic and intestinal inflammatory status, respectively. Analysis of immune parameters in intraepithelial lymphocytes showed significant differences among the two types of bread indicating a positive effect of the wheat-lentil bread on the intestinal immune system, whereas both breads induced a reduction in serum IL-10.
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OBJECTIVE: Aging induces several physiologic and immune changes. The usefulness of probiotics in ameliorating age-related disorders remains largely unexplored. The aim of this study was to evaluate the effectiveness of a Bifidobacterium longum Bar33 and Lactobacillus helveticus Bar13 mixture in improving the physiologic status and immunity of older adults (over 75 years). Furthermore, the possible role of such mixture in ameliorating gut immunity in aged mice was investigated. METHODS: A randomized, double-blind, placebo-controlled trial was conducted with 98 adults (84.6 ± 7.8 y), supplemented for 30 d with a biscuit containing a probiotic mixture of B. longum Bar33 and L. helveticus Bar13 (1:1), or no probiotics, as placebo. Blood was collected for analysis of biochemical parameters, lymphocyte subpopulations, natural killer activity, and cytokine release. Aged Balb/c mice received the same probiotic mixture or placebo daily for 28 d, then blood and intestinal lymphocyte subpopulations were analyzed. RESULTS: The probiotic mixture ameliorated immune response in older adults by increasing naive, activated memory, regulatory T cells, B cells, and natural killer activity and decreasing memory T cells compared with placebo (P < 0.05). The biochemical parameters did not change after probiotic supplementation. In the gut of old mice, the two probiotics modulated cells crucial for gut immune homeostasis by increasing regulatory T (Treg and Tr1) and decreasing γδ T cells compared with control mice (P < 0.05). In addition, B cells increased in the gut and blood of probiotic-treated mice. CONCLUSION: Results from the present study data indicated that B. longum Bar33 and L. helveticus Bar13 improve immune function at intestinal and peripheral sites in aging.
Assuntos
Bifidobacterium longum , Suplementos Nutricionais/microbiologia , Imunidade , Lactobacillus helveticus , Probióticos/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Animais , Método Duplo-Cego , Feminino , Microbioma Gastrointestinal/imunologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Zinc may contribute to the host defense by maintaining the membrane barrier. In this study, we questioned whether zinc deficiency affects the membrane function and junctional structure of intestinal epithelial cells, causing increased neutrophil migration. We used the Caco-2 cell line grown in control (C), zinc-deficient, or zinc-replete medium until differentiation. Zinc deprivation induced a decrease of transepithelial electrical resistance and alterations to tight and adherens junctions, with delocalization of zonula occludens (ZO-1), occludin, beta-catenin, and E-cadherin. Disorganization of F-actin and beta-tubulin was also found in zinc deficiency. These changes were associated with a loss of the amounts of ZO-1, occluding, and beta-tubulin. In addition, zinc deficiency caused a dephosphorylation of occludin and hyperphosphorylation of beta-catenin and ZO-1. Disruption of membrane barrier integrity led to increased migration of neutrophils. In addition, zinc deficiency induced an increase in the secretion of interleukin-8, epithelial neutrophil activating peptide-78, and growth-regulated oncogene-alpha, alterations that were not found when culture medium was replete with zinc. These results provide new information on the critical role played by dietary zinc in the maintenance of membrane barrier integrity and in controlling inflammatory cell infiltration.
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Membrana Celular/efeitos dos fármacos , Neutrófilos/fisiologia , Zinco/deficiência , Junções Aderentes/efeitos dos fármacos , Junções Aderentes/fisiologia , Células CACO-2 , Permeabilidade da Membrana Celular , Quimiocinas/genética , Quimiocinas/metabolismo , Meios de Cultura , Citoesqueleto/fisiologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/fisiologia , Humanos , Inflamação , Mucosa Intestinal/citologia , Fosforilação , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/fisiologia , Regulação para Cima/efeitos dos fármacosRESUMO
In western societies where most of the day is spent in the postprandial state, the existence of oxidative and inflammatory stress conditions makes postprandial stress an important factor involved in the development of cardiovascular risk factors. A large body of evidence have been accumulated on the anti-inflammatory effects of probiotics, but no information is available on the mechanisms through which intestinal microbiota modulates redox unbalance associated with inflammatory stress. Here, we aimed to investigate the ability of Lactobacillus casei Shirota (LS) to induce an antioxidant response to counteract oxidative and inflammatory stress in an in vitro model of enterocytes. Our results show that pretreatment of enterocytes with LS prevents membrane barrier disruption and cellular reactive oxygen species (ROS) accumulation inside the cells, modulates the expression of the gastro-intestinal glutathione peroxidase (GPX2) antioxidant enzyme, and reduces p65 phosphorylation, supporting the involvement of the Nfr2 and nuclear factor kappa B pathways in the activation of antioxidant cellular defenses by probiotics. These results suggest, for the first time, a redox mechanism by LS in protecting intestinal cells from AAPH-induced oxidative and inflammatory stress.
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Amidinas/farmacologia , Enterócitos/efeitos dos fármacos , Enterócitos/metabolismo , Infecções por Bactérias Gram-Positivas/metabolismo , Infecções por Bactérias Gram-Positivas/microbiologia , Lacticaseibacillus casei/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio , Biomarcadores , Linhagem Celular , Permeabilidade da Membrana Celular/efeitos dos fármacos , Enterócitos/ultraestrutura , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Glutationa Peroxidase/metabolismo , Humanos , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de SinaisRESUMO
Lactobacilli have a potential to overcome intestinal disorders; however, the exact mode of action is still largely unknown. In this study, we have used the intestinal porcine intestinal IPEC-1 epithelial cells as a model to investigate a possible protective activity of a new Lactobacillus species, the L. sobrius DSM 16698(T), against intestinal injury induced by enterotoxigenic Escherichia coli (ETEC) K88 infection and the underlying mechanisms. Treatment of infected cells with L. sobrius strongly reduced the pathogen adhesion. L. sobrius was also able to prevent the ETEC-induced membrane damage by inhibiting delocalization of zonula occludens (ZO)-1, reduction of occludin amount, rearrangement of F-actin, and dephosphorylation of occludin caused by ETEC. RT-PCR and ELISA experiments showed that L. sobrius counteracted the ETEC-induced increase of IL-8 and upregulated the IL-10 expression. The involvement of IL-8 in the deleterious effects of ETEC was proven by neutralization of IL-8 with a specific antibody. A crucial role of IL-10 was indicated by blockage of IL-10 production with neutralizing anti-IL-10 antibody that fully abrogated the L. sobrius protection. L. sobrius was also able to inhibit the internalization of ETEC, which was likely favored by the leaking barrier. The protective effects were not found with L. amylovorus DSM 20531(T) treatment, a strain derived from cattle waste but phylogenetically closely related to L. sobrius. Together, the data indicate that L. sobrius exerts protection against the harmful effects of ETEC by different mechanisms, including pathogen adhesion inhibition and maintenance of membrane barrier integrity through IL-10 regulation.
Assuntos
Escherichia coli Enterotoxigênica/fisiologia , Células Epiteliais/microbiologia , Infecções por Escherichia coli/microbiologia , Lactobacillus/classificação , Lactobacillus/fisiologia , Animais , Aderência Bacteriana , Linhagem Celular , Membrana Celular , Células Epiteliais/citologia , Interleucina-1/metabolismo , Interleucina-10/metabolismo , Proteínas de Membrana/metabolismo , Ocludina , Fosfoproteínas/metabolismo , Transdução de Sinais , Suínos/microbiologia , Proteína da Zônula de Oclusão-1RESUMO
The highly nutritional and ecofriendly Spirulina (Arthrospira platensis) has hypolipidemic, hypoglycemic, and antihypertensive properties. Spirulina contains functional compounds, such as phenolics, phycocyanins, and polysaccharides, with antioxidant, anti-inflammatory, and immunostimulating effects. Studies conducted on Spirulina suggest that it is safe in healthy subjects, but attitude to eating probably affects the acceptability of Spirulina containing foods. Although the antioxidant effect of Spirulina is confirmed by the intervention studies, the concerted modulation of antioxidant and inflammatory responses, suggested by in vitro and animal studies, requires more confirmation in humans. Spirulina supplements seem to affect more effectively the innate immunity, promoting the activity of natural killer cells. The effects on cytokines and on lymphocytes' proliferation depend on age, gender, and body weight differences. In this context, ageing and obesity are both associated with chronic low grade inflammation, immune impairment, and intestinal dysbiosis. Microbial-modulating activities have been reported in vitro, suggesting that the association of Spirulina and probiotics could represent a new strategy to improve the growth of beneficial intestinal microbiota. Although Spirulina might represent a functional food with potential beneficial effects on human health, the human interventions used only supplements. Therefore, the effect of food containing Spirulina should be evaluated in the future.