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Introduction: Medicinal mushrooms have been used for the treatment of diseases and general promotion of health for many centuries. Recent pharmacological research into medicinal mushrooms has identified various therapeutic properties, with applications in modern medicine.Aim: To evaluate the anti-cancer activities of Fomitopsis pinicola (F. pinicola) alcoholic extract in an in vivo setting.Methods: The anti-tumour effect of the F. pinicola extract was tested in a xenograft immune-compromised Rag-1 mouse model. This was followed by RT-PCR and metabolomics analyses.Results: There were no observable differences in tumor growth between treated and non-treated groups. The bioactive components were not detected in the mouse plasma or the tumor site.Conclusions: The extract was poorly absorbed; this is likely due to the timing of treatment, dosage levels and modifications made to the extract where the alcohol-based solvent was replaced with water. This, in combination with fractionation studies which identified most anti-cancer compounds to be hydrophobic, largely explained the lack of anti-cancer activities in vivo.
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Antineoplásicos Fitogênicos/uso terapêutico , Coriolaceae , Neoplasias Experimentais/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Neoplasias Experimentais/metabolismo , Extratos Vegetais/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Crohn's disease and ulcerative colitis, the two common forms of inflammatory bowel disease (IBD), affect over 2.5 million people of European ancestry, with rising prevalence in other populations. Genome-wide association studies and subsequent meta-analyses of these two diseases as separate phenotypes have implicated previously unsuspected mechanisms, such as autophagy, in their pathogenesis and showed that some IBD loci are shared with other inflammatory diseases. Here we expand on the knowledge of relevant pathways by undertaking a meta-analysis of Crohn's disease and ulcerative colitis genome-wide association scans, followed by extensive validation of significant findings, with a combined total of more than 75,000 cases and controls. We identify 71 new associations, for a total of 163 IBD loci, that meet genome-wide significance thresholds. Most loci contribute to both phenotypes, and both directional (consistently favouring one allele over the course of human history) and balancing (favouring the retention of both alleles within populations) selection effects are evident. Many IBD loci are also implicated in other immune-mediated disorders, most notably with ankylosing spondylitis and psoriasis. We also observe considerable overlap between susceptibility loci for IBD and mycobacterial infection. Gene co-expression network analysis emphasizes this relationship, with pathways shared between host responses to mycobacteria and those predisposing to IBD.
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Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Interações Hospedeiro-Patógeno , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/microbiologia , Mycobacterium/imunologia , Colite Ulcerativa/genética , Colite Ulcerativa/imunologia , Colite Ulcerativa/microbiologia , Colite Ulcerativa/fisiopatologia , Doença de Crohn/genética , Doença de Crohn/imunologia , Doença de Crohn/microbiologia , Doença de Crohn/fisiopatologia , Genoma Humano/genética , Haplótipos/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/fisiopatologia , Mycobacterium/patogenicidade , Infecções por Mycobacterium/genética , Infecções por Mycobacterium/microbiologia , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Crohn's disease and ulcerative colitis are the two major forms of inflammatory bowel disease; treatment strategies have historically been determined by this binary categorisation. Genetic studies have identified 163 susceptibility loci for inflammatory bowel disease, mostly shared between Crohn's disease and ulcerative colitis. We undertook the largest genotype association study, to date, in widely used clinical subphenotypes of inflammatory bowel disease with the goal of further understanding the biological relations between diseases. METHODS: This study included patients from 49 centres in 16 countries in Europe, North America, and Australasia. We applied the Montreal classification system of inflammatory bowel disease subphenotypes to 34,819 patients (19,713 with Crohn's disease, 14,683 with ulcerative colitis) genotyped on the Immunochip array. We tested for genotype-phenotype associations across 156,154 genetic variants. We generated genetic risk scores by combining information from all known inflammatory bowel disease associations to summarise the total load of genetic risk for a particular phenotype. We used these risk scores to test the hypothesis that colonic Crohn's disease, ileal Crohn's disease, and ulcerative colitis are all genetically distinct from each other, and to attempt to identify patients with a mismatch between clinical diagnosis and genetic risk profile. FINDINGS: After quality control, the primary analysis included 29,838 patients (16,902 with Crohn's disease, 12,597 with ulcerative colitis). Three loci (NOD2, MHC, and MST1 3p21) were associated with subphenotypes of inflammatory bowel disease, mainly disease location (essentially fixed over time; median follow-up of 10·5 years). Little or no genetic association with disease behaviour (which changed dramatically over time) remained after conditioning on disease location and age at onset. The genetic risk score representing all known risk alleles for inflammatory bowel disease showed strong association with disease subphenotype (p=1·65â×â10(-78)), even after exclusion of NOD2, MHC, and 3p21 (p=9·23â×â10(-18)). Predictive models based on the genetic risk score strongly distinguished colonic from ileal Crohn's disease. Our genetic risk score could also identify a small number of patients with discrepant genetic risk profiles who were significantly more likely to have a revised diagnosis after follow-up (p=6·8â×â10(-4)). INTERPRETATION: Our data support a continuum of disorders within inflammatory bowel disease, much better explained by three groups (ileal Crohn's disease, colonic Crohn's disease, and ulcerative colitis) than by Crohn's disease and ulcerative colitis as currently defined. Disease location is an intrinsic aspect of a patient's disease, in part genetically determined, and the major driver to changes in disease behaviour over time. FUNDING: International Inflammatory Bowel Disease Genetics Consortium members funding sources (see Acknowledgments for full list).
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Colite Ulcerativa/genética , Doença de Crohn/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Adulto , Alelos , Feminino , Genótipo , Cadeias HLA-DRB1/genética , Fator de Crescimento de Hepatócito/genética , Humanos , Imunoensaio , Complexo Principal de Histocompatibilidade/genética , Masculino , Proteína Adaptadora de Sinalização NOD2/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas/genética , Medição de Risco , Adulto JovemRESUMO
Chronic inflammation is defined by the persistence of inflammatory processes beyond their physiological function, resulting in tissue destruction. Chronic inflammation is implicated in the progression of many chronic diseases and plays a central role in chronic inflammatory and autoimmune disease. As such, this review aims to collate some of the latest research in relation to genetic and environmental susceptibilities to chronic inflammation. In the genetic section, we discuss some of the updates in cytokine research and current treatments that are being developed. We also discuss newly identified canonical and non-canonical genes associated with chronic inflammation. In the environmental section, we highlight some of the latest updates and evidence in relation to the role that infection, diet and stress play in promoting inflammation. The aim of this review is to provide an overview of the latest research to build on our current understanding of chronic inflammation. It highlights the complexity associated with chronic inflammation, as well as provides insights into potential new targets for therapies that could be used to treat chronic inflammation and consequently prevent disease progression.
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Exposição Ambiental/efeitos adversos , Predisposição Genética para Doença , Inflamação/etiologia , Doença Crônica , Citocinas/genética , Citocinas/metabolismo , Dieta , Humanos , Infecções/complicações , Inflamação/genética , Estresse Psicológico/complicaçõesRESUMO
Genomic instability can initiate cancer, augment progression, and influence the overall prognosis of the affected patient. Genomic instability arises from many different pathways, such as telomere damage, centrosome amplification, epigenetic modifications, and DNA damage from endogenous and exogenous sources, and can be perpetuating, or limiting, through the induction of mutations or aneuploidy, both enabling and catastrophic. Many cancer treatments induce DNA damage to impair cell division on a global scale but it is accepted that personalized treatments, those that are tailored to the particular patient and type of cancer, must also be developed. In this review, we detail the mechanisms from which genomic instability arises and can lead to cancer, as well as treatments and measures that prevent genomic instability or take advantage of the cellular defects caused by genomic instability. In particular, we identify and discuss five priority targets against genomic instability: (1) prevention of DNA damage; (2) enhancement of DNA repair; (3) targeting deficient DNA repair; (4) impairing centrosome clustering; and, (5) inhibition of telomerase activity. Moreover, we highlight vitamin D and B, selenium, carotenoids, PARP inhibitors, resveratrol, and isothiocyanates as priority approaches against genomic instability. The prioritized target sites and approaches were cross validated to identify potential synergistic effects on a number of important areas of cancer biology.
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Instabilidade Genômica/efeitos dos fármacos , Neoplasias/dietoterapia , Neoplasias/genética , Centrossomo/metabolismo , Dano ao DNA/genética , Reparo do DNA/genética , Dieta , Instabilidade Genômica/genética , Humanos , Neoplasias/patologia , Prognóstico , Telomerase/antagonistas & inibidores , Telomerase/genéticaRESUMO
BACKGROUND: Androgen deprivation therapy (ADT) is an effective palliation treatment in men with advanced prostate cancer (PC). However, ADT has well documented side effects that could alter the patient's health-related quality of life (HRQoL). The current study aims to test whether a genetic stratification could provide better knowledge for optimising ADT options to minimize HRQoL effects. METHODS: A cohort of 206 PC survivors (75 treated with and 131 without ADT) was recruited with written consent to collect patient characteristics, clinical data and HRQoL data related to PC management. The primary outcomes were the percentage scores under each HRQoL subscale assessed using the European Organisation for Research and Treatment of Cancer Quality of Life questionnaires (QLQ-C30 and PR25) and the Depression Anxiety Stress Scales developed by the University of Melbourne, Australia. Genotyping of these men was carried out for the aldo-keto reductase family 1, member C3 (AKR1C3) rs12529 single nucleotide polymorphism (SNP). Analysis of HRQoL scores were carried out against ADT duration and in association with the AKR1C3 rs12529 SNP using the generalised linear model. P-values <0 · 05 were considered significant, and were further tested for restriction with Bonferroni correction. RESULTS: Increase in hormone treatment-related effects were recorded with long-term ADT compared to no ADT. The C and G allele frequencies of the AKR1C3rs12529 SNP were 53·4 % and 46·6 % respectively. Hormone treatment-related symptoms showed an increase with ADT when associated with the AKR1C3 rs12529 G allele. Meanwhile, decreasing trends on cancer-specific symptoms and increased sexual interest were recorded with no ADT when associated with the AKR1C3 rs12529 G allele and reverse trends with the C allele. As higher incidence of cancer-specific symptoms relate to cancer retention it is possible that associated with the C allele there could be higher incidence of unresolved cancers under no ADT options. CONCLUSIONS: If these findings can be reproduced in larger homogeneous cohorts, a genetic stratification based on the AKR1C3 rs12529 SNP, can minimize ADT-related HRQoL effects in PC patients. Our data additionally show that with this stratification it could also be possible to identify men needing ADT for better oncological advantage.
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3-Hidroxiesteroide Desidrogenases/genética , Aldeído Redutase/genética , Antagonistas de Androgênios/efeitos adversos , Hormônio Liberador de Gonadotropina/agonistas , Hidroxiprostaglandina Desidrogenases/genética , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Membro C3 da Família 1 de alfa-Ceto Redutase , Aldo-Ceto Redutases , Humanos , Masculino , Nova Zelândia , Neoplasias da Próstata/enzimologiaRESUMO
Maternal stress during pregnancy has been associated with detrimental cognitive developmental outcomes in offspring. This study investigated whether antenatal maternal perceived stress and variants of the rs12193738 and rs2179515 polymorphisms on the KIAA0319 gene interact to affect reading ability and full-scale IQ (FSIQ) in members of the longitudinal Auckland Birthweight Collaborative study. Antenatal maternal stress was measured at birth, and reading ability was assessed at ages 7 and 16. Reading data were available for 500 participants at age 7 and 479 participants at age 16. FSIQ was measured at ages 7 and 11. At age 11, DNA samples were collected. Analyses of covariance revealed that individuals with the TT genotype of the rs12193738 polymorphism exposed to high maternal stress during pregnancy possessed significantly poorer reading ability (as measured by Woodcock-Johnson Word Identification standard scores) during adolescence compared with TT carriers exposed to low maternal stress. TT carriers of the rs12193738 SNP also obtained lower IQ scores at age 7 than C allele carriers. These findings suggest that the KIAA0319 gene is associated with both reading ability and general cognition, but in different ways. The effect on IQ appears to occur earlier in development and is transient, whereas the effect of reading ability occurs later and is moderated by antenatal maternal stress. Copyright © 2016 John Wiley & Sons, Ltd.
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Dislexia/genética , Proteínas do Tecido Nervoso/genética , Complicações na Gravidez/psicologia , Leitura , Estresse Psicológico/psicologia , Adolescente , Adulto , Criança , Cognição , Disfunção Cognitiva/genética , Dislexia/psicologia , Feminino , Predisposição Genética para Doença , Variação Genética , Genótipo , Humanos , Estudos Longitudinais , Masculino , Polimorfismo de Nucleotídeo Único , GravidezRESUMO
For the first time this study has shown a direct effect of food textural complexity on satiation. Independent of oral processing time, increasing the textural complexity of a food significantly decreased food intake. Foods with complex textures stimulate many sensory perceptions during oral processing, with a succession of textures perceived between first bite and swallow. Previously the impact of texture on satiation (commonly tested by increasing viscosities of semi-solids) has been explained by texture's influence on oral processing time; a long oral processing time enhances satiation. The results of the current study show that subjects in a randomised cross-over trial who consumed a "starter" (preload) model food with high textural complexity went on to eat significantly less of a two course ad libitum meal. Subjects who consumed a "starter" model food with low textural complexity, but with the same flavour, energy density and oral processing time, ate significantly more of the same ad libitum meal. The results show that increasing the number of textures perceived during chewing of a solid food triggers the satiation response earlier than when chewing a less texturally complex food. Increasing textural complexity of manufactured foods, to allow for greater sensory stimulation per bite, could potentially be used as a tool to enhance the satiation response and decrease food intake.
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Alimentos Especializados , Mastigação , Modelos Químicos , Resposta de Saciedade , Sensação , Regulação para Cima , Regulação do Apetite , Estudos Cross-Over , Dieta Redutora/métodos , Ingestão de Energia , Comportamento Alimentar , Feminino , Manipulação de Alimentos , Alimentos Especializados/análise , Humanos , Almoço , Masculino , Nova Zelândia , Sobrepeso/prevenção & controle , Autorrelato , Propriedades de SuperfícieRESUMO
For many years, there has been confusion about the role that nutrition plays in inflammatory bowel diseases (IBD). It is apparent that good dietary advice for one individual may prove inappropriate for another. As with many diseases, genome-wide association studies across large collaborative groups have been important in revealing the role of genetics in IBD, with more than 200 genes associated with susceptibility to the disease. These associations provide clues to explain the differences in nutrient requirements among individuals. In addition to genes directly involved in the control of inflammation, a number of the associated genes play roles in modulating the gut microbiota. Cell line models enable the generation of hypotheses as to how various bioactive dietary components might be especially beneficial for certain genetic groups. Animal models are necessary to mimic aspects of the complex aetiology of IBD, and provide an important link between tissue culture studies and human trials. Once we are sufficiently confident of our hypotheses, we can then take modified diets to an IBD population that is stratified according to genotype. Studies in IBD patients fed a Mediterranean-style diet have been important in validating our hypotheses and as a proof-of-principle for the application of these sensitive omics technologies to aiding in the control of IBD symptoms.
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Curcumina/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Estado Nutricional , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Perfilação da Expressão Gênica/métodos , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Metabolômica/métodos , Proteômica/métodosRESUMO
Intestinal dysbiosis is thought to be an important cause of disease progression and the gastrointestinal symptoms experienced in patients with inflammatory bowel disease (IBD). Inflammation appears to be a major contributor in perpetuating a dysregulated gut microbiota. Although current drug therapies can significantly induce and maintain disease remission, there is no cure for these diseases. Nevertheless, ongoing human studies investigating dietary fibre interventions may potentially prove to exert beneficial outcomes for IBD. Postulated mechanisms include direct interactions with the gut mucosa through immunomodulation, or indirectly through the microbiome. Component species of the microbiome may degrade dietary-fibre polysaccharides and ferment the products to form short-chain fatty acids such as butyrate. Prebiotic dietary fibres may also act more directly by altering the composition of the microbiome. Longer term benefits in reducing the risk of more aggressive disease or colorectal cancer may require other dietary fibre sources such as wheat bran or psyllium. By critically examining clinical trials that have used dietary fibre supplements or dietary patterns containing specific types or amounts of dietary fibres, it may be possible to assess whether varying the intake of specific dietary fibres may offer an efficient treatment for IBD patients.
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Fibras na Dieta/uso terapêutico , Doenças Inflamatórias Intestinais/dietoterapia , Humanos , Prebióticos , Psyllium/uso terapêuticoRESUMO
Olive leaf extract (OLE) has been used for many years for its putative health benefits, but, to date, scientific evidence for the basis of these effects has been weak. Although recent literature has described a link between ailments such as cardiovascular disease, diabetes and cancer and a protective effect of polyphenols in the OLE, the mode of action is still unclear. Here, we describe a double-blinded placebo (PBO)-controlled trial, in which gene expression profiles of peripheral blood mononuclear cells from healthy male volunteers (n = 29) were analysed to identify genes that responded to OLE, following an eight-week intervention with 20 mL daily consumption of either OLE or PBO. Differences between groups were determined using an adjusted linear model. Subsequent analyses indicated downregulation of genes important in inflammatory pathways, lipid metabolism and cancer as a result of OLE consumption. Gene expression was verified by real-time PCR for three genes (EGR1, COX-2 and ID3). The results presented here suggest that OLE consumption may result in health benefits through influencing the expression of genes in inflammatory and metabolic pathways. Future studies with a larger study group, including male and female participants, looking into direct effects of OLE on lipid metabolism and inflammation are warranted.
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Suplementos Nutricionais , Regulação da Expressão Gênica/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Olea/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Ontologia Genética , Humanos , Imunidade Inata/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Masculino , Anotação de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Placebos , Extratos Vegetais/administração & dosagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Transcrição Gênica/efeitos dos fármacosRESUMO
BACKGROUND: There is strong evidence to support a genetic predisposition to eczema and more recently studies have suggested that probiotics might be used to prevent eczema by modifying the expression of putative allergy-associated genes. The aim of this present study was to investigate whether two probiotics, Lactobacillus rhamnosus HN001 (HN001) and Bifidobacterium animalis subsp. lactis HN019 (HN019), can modify the known genetic predisposition to eczema conferred by genetic variation in the Toll-like receptor (TLR) genes in a high-risk infant population. METHODS: We selected 54 SNPs in the Toll-like receptor genes. These SNPs were analysed in 331 children of sole European ancestry as part of a double-blind, randomized, placebo-controlled trial examining the effects of HN001 and HN019 supplementation on eczema development and atopic sensitization. RESULTS: The data showed that 26 TLR SNPs interacted with HN001 resulting in a significantly reduced risk of eczema, 18 for eczema severity as defined by SCORAD ≥ 10 and 20 for atopic sensitization compared to placebo. There were only two SNPs that interacted with HN019 resulting in a reduced risk of eczema, eczema severity or atopy. CONCLUSIONS: This is the first study to show that the negative impact of specific TLR genotypes may be positively affected by probiotic supplementation. HN001 exhibits a much stronger effect than HN019 in this respect.
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Bifidobacterium/imunologia , Dermatite Atópica/tratamento farmacológico , Eczema/dietoterapia , Lacticaseibacillus rhamnosus/imunologia , Probióticos/administração & dosagem , Receptores Toll-Like/genética , População Branca , Pré-Escolar , Dermatite Atópica/genética , Dermatite Atópica/imunologia , Suplementos Nutricionais , Método Duplo-Cego , Eczema/genética , Eczema/imunologia , Feminino , Seguimentos , Predisposição Genética para Doença , Humanos , Lactente , Recém-Nascido , Efeito Placebo , Polimorfismo de Nucleotídeo Único , Gravidez , RiscoRESUMO
BACKGROUND: Inflammation is an essential immune response; however, chronic inflammation results in disease including Crohn's disease. Therefore, reducing the inflammation can yield a significant health benefit, and one way to achieve this is through diet. We developed a Mediterranean-inspired anti-inflammatory diet and used this diet in a 6-week intervention in a Crohn's disease population. We examined changes in inflammation and also in the gut microbiota. We compared the results of established biomarkers, C-reactive protein and the micronuclei assay, of inflammation with results from a transcriptomic approach. RESULTS: Data showed that being on our diet for 6 weeks was able to reduce the established biomarkers of inflammation. However, using transcriptomics, we observed significant changes in gene expression. Although no single gene stood out, the cumulative effect of small changes in many genes combined to have a beneficial effect. Data also showed that our diet resulted in a trend of normalising the microbiota. CONCLUSIONS: This study showed that our Mediterranean-inspired diet appeared to benefit the health of people with Crohn's disease. Our participants showed a trend for reduced markers of inflammation and normalising of the microbiota. The significant changes in gene expression after 6 weeks highlighted the increased sensitivity of using transcriptomics when compared to the established biomarkers and open up a new era of dietary intervention studies.
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Doença de Crohn/dietoterapia , Doença de Crohn/genética , Dieta Mediterrânea , Inflamação/dietoterapia , Inflamação/genética , Transcriptoma/genética , Adulto , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Dano ao DNA , Feminino , Trato Gastrointestinal/microbiologia , Expressão Gênica , Humanos , Masculino , Microbiota , Testes para Micronúcleos , Pessoa de Meia-Idade , Projetos Piloto , RNA/sangueRESUMO
BACKGROUND: Children born small-for-gestational-age (SGA) are at increased risk of developing obesity and metabolic diseases later in life, a risk which is magnified if followed by accelerated postnatal growth. We investigated whether common gene variants associated with adult obesity were associated with increased postnatal growth, as measured by BMI z-score, in children born SGA and appropriate for gestational age (AGA) in the Auckland Birthweight Collaborative. METHODS: A total of 37 candidate SNPs were genotyped on 547 European children (228 SGA and 319 AGA). Repeated measures of BMI (z-score) were used for assessing obesity status, and results were corrected for multiple testing using the false discovery rate. RESULTS: SGA children had a lower BMI z-score than non-SGA children at assessment age 3.5, 7 and 11 years. We confirmed 27 variants within 14 obesity risk genes to be individually associated with increasing early childhood BMI, predominantly in those born AGA. CONCLUSIONS: Genetic risk variants are less important in influencing early childhood BMI in those born SGA than in those born AGA, suggesting that non-genetic or environmental factors may be more important in influencing childhood BMI in those born SGA.
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Recém-Nascido Pequeno para a Idade Gestacional , Obesidade/genética , Criança , Predisposição Genética para Doença , Humanos , Recém-Nascido , Nova Zelândia , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Selenium (Se) supplementation was tested in a group of healthy men from Auckland, New Zealnd with selenized yeast (Selplex, 200 µg/day) as the supplementation mode. A set of biomarkers, including DNA damage levels and seleno-antioxidant enzyme levels, were evaluated at pre- and postsupplementation time points. Supplementation produced significant increases in serum Se levels, red blood cell (RBC) thioredoxin reductase (TR) activity and peroxide-induced DNA damage, when the mean baseline serum Se level was 110 ng/ml. Those with higher baseline serum Se levels gained less serum Se and showed a significant reduction of RBC glutathione peroxidase (GPx) activity by supplementation. The optimum benefits of supplementation on DNA stability are observed when the serum Se level reaches between >120 and <160 ng/ml. However, the most significant observation was that those with highest baseline DNA damage benefit the most from Se supplementation, whereas those having lower baseline DNA damage are disadvantaged. A dose of 200 µg/day selenized yeast was also shown to be a safer supplementation option compared to a similar dose of selenomethionine (SeMet). This study highlights the requirement for prestratification of a population by standing serum Se level and baseline DNA damage level, before any Se supplementation is carried out.
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Suplementos Nutricionais , Selênio/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA/sangue , DNA/efeitos dos fármacos , Dano ao DNA , Glutationa Peroxidase/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Peróxidos/farmacologia , Selênio/sangue , Telomerase/sangue , LevedurasRESUMO
Probiotic bacteria were previously encapsulated in sub-100 µm Ca(2+) alginate microcapsules for enhanced survival in human gastrointestinal tract. The aim of this study is to evaluate the altered mucoadhesive property of the probiotic delivery system by coating it with mucoadhesive chitosan or thiolated chitosan, for prolonged retention in human colon. The results confirmed that cross-linking with calcium ions reduced the mucoadhesive property of alginate hydrogel, thus questioning the intrinsic mucoadhesiveness of uncoated systems. In contrast, chitosan and thiolated chitosan were found to be adsorbed on sub-100 µm Ca(2+) alginate microcapsules, and substantially improved the mucoadhesion performance of the system. The adhesion performance was correlated to the amount of mucoadhesive coating polymer adsorbed on the surface of the system. The coated system was demonstrated on HT29-MTX colonic epithelial monolayer to deliver markedly higher amount of probiotic bacteria to the in vitro model of colonic mucosa. Additionally, the coatings were also found to exert significantly stronger mucoadhesion to colonic mucosa tissue at slight acid neutral pH with less ambient water, which conforms to the physiological environment of the colon, thus supporting prolonged retention in this region.
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Aderência Bacteriana , Quitosana , Colo , Limosilactobacillus reuteri , Probióticos , Alginatos/química , Alginatos/farmacologia , Cálcio/química , Cálcio/farmacologia , Cápsulas , Linhagem Celular , Quitosana/química , Quitosana/farmacologia , Ácido Glucurônico/química , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/química , Ácidos Hexurônicos/farmacologia , Humanos , Probióticos/química , Probióticos/farmacologiaRESUMO
A 1-yr carcinogenicity bioassay was conducted in rats fed 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), simultaneously with AIN-76/ high-fat (HF) diet alone, or with 10% starch replaced with kumara, pineapple, coconut, or taro, prepared as for a human diet. All of the non-IQ treated control, kumara, pineapple, or taro but not coconut-fed rats survived to 1 yr. None of the IQ-fed animals survived to 1 yr and although there were minor survival time differences among the groups, none was statistically significant. At sacrifice, IQ/HF controls had tumors in the skin, Zymbal's gland, ear canal, oral cavity, liver, and small intestine, totaling 32 among 20 animals. Kumara-fed rats had a similar tumor distribution but no tumors in the ear or oral cavity, and a total of 27 tumors among 20 animals, whereas pineapple-fed rats showed a somewhat lower tumor incidence (23/20 animals), including no small intestine lesions. Unexpectedly, a higher tumor incidence, especially of skin tumors, was seen in coconut and taro-fed animals (35/20 and 41/20 animals, respectively). In particular, the incidence of malignant liver tumors and gastrointestinal tumors were significantly increased in the taro-fed group in comparison with the kumara group.
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Carcinógenos/administração & dosagem , Dieta , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/prevenção & controle , Plantas Comestíveis , Quinolinas/administração & dosagem , Ananas/química , Animais , Anticarcinógenos/administração & dosagem , Cocos/química , Colocasia/química , Dieta/etnologia , Peixes , Temperatura Alta , Ipomoea batatas/química , Masculino , Carne/análise , Nova Zelândia , Ilhas do Pacífico , Fitoterapia , Ratos , Ratos Endogâmicos F344RESUMO
Selenium (Se) is an essential micronutrient for humans, acting as a component of the unusual amino acids, selenocysteine (Se-Cys) and selenomethionine (Se-Met). Where Se levels are low, the cell cannot synthesise selenoproteins, although some selenoproteins and some tissues are prioritised over others. Characterised functions of known selenoproteins, include selenium transport (selenoprotein P), antioxidant/redox properties (glutathione peroxidases (GPxs), thioredoxin reductases and selenoprotein P) and anti-inflammatory properties (selenoprotein S and GPx4). Various forms of Se are consumed as part of a normal diet, or as a dietary supplement. Supplementation of tissue culture media, animal or human diets with moderate levels of certain Se compounds may protect against the formation of DNA adducts, DNA or chromosome breakage, and chromosome gain or loss. Protective effects have also been shown on mitochondrial DNA, and on telomere length and function. Some of the effects of Se compounds on gene expression may relate to modulation of DNA methylation or inhibition of histone deacetylation. Despite a large number of positive effects of selenium and selenoproteins in various model systems, there have now been some human clinical trials that have shown adverse effects of Se supplementation, according to various endpoints. Too much Se is as harmful as too little, with animal models showing a "U"-shaped efficacy curve. Current recommended daily allowances differ among countries, but are generally based on the amount of Se necessary to saturate GPx enzymes. However, increasing evidence suggests that other enzymes may be more important than GPx for Se action, that optimal levels may depend upon the form of Se being ingested, and vary according to genotype. New paradigms, possibly involving nutrigenomic tools, will be necessary to optimise the forms and levels of Se desirable for maximum protection of genomic stability in all humans.
Assuntos
Instabilidade Genômica , Selênio/fisiologia , Animais , Antioxidantes/metabolismo , Deleção Cromossômica , Adutos de DNA/metabolismo , DNA Mitocondrial , Dieta , Suplementos Nutricionais , Epigênese Genética , Expressão Gênica , Humanos , Neoplasias/etiologia , Necessidades Nutricionais , Selênio/deficiência , Selenoproteínas/metabolismo , Telômero/metabolismo , Oligoelementos/metabolismoRESUMO
AIM: The functional polymorphism Val158Met in the catechol-O-methyltransferase (COMT) gene was analysed to determine its association with maternal stress and childhood total difficulties. METHOD: Data were collected at birth from a group of infants who were born small for gestational age and a group who were born at an appropriate size for gestational age and had been enrolled in the Auckland Birthweight Collaborative Study. Children were followed up at the ages of 1 year, 3 years 6 months, 7 years, and 11 years. At the age of 11 years, DNA samples were collected from 546 children (270 females, 276 males): 227 children born small for gestational age and 319 children born at an appropriate size for gestational age. The main independent variable was perceived maternal stress at birth and at 7 and 11 years of age, assessed using the total difficulties scale of the Strength and Difficulties Questionnaire. IQ was assessed at the age of 7 years. RESULTS: Met/Met homozygotes were at a significantly increased risk of behavioural and emotional problems at the ages of 7 (p=0.002) and 11 years (p=0.003), relative to either heterozygous or homozygous carriers of the Val158Met polymorphism, but only when they were exposed to maternal stress in utero. Met/Met homozygotes had, on average, IQ scores that were four points higher than those of Val/Val homozygotes (p=0.010). INTERPRETATION: These findings emphasize the potential long-term consequences of prenatal stress for genetically susceptible individuals during neurodevelopment in utero. Our findings add to the general understanding of the aetiology and developmental nature of childhood emotional and behavioural problems.
Assuntos
Catecol O-Metiltransferase/genética , Transtornos do Comportamento Infantil/genética , Metionina/genética , Polimorfismo de Nucleotídeo Único/genética , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Valina/genética , Fatores Etários , Criança , Transtornos do Comportamento Infantil/etiologia , Pré-Escolar , Feminino , Genótipo , Humanos , Inteligência , Estudos Longitudinais , Masculino , Relações Mãe-Filho , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genéticaRESUMO
The aim of this study was to apply flow cytometric (FCM) analysis to assess the use of sucrose and lecithin vesicles for the protection of probiotic lactic acid bacteria in response to the challenge of gastric acidity and bile salts. FCM analysis in combination with fluorescent probes carboxyfluorescein (cF) and propidium iodide was used to reveal the physiological heterogeneity in the stressed bacteria population. Three subpopulations (intact, stressed, and damaged) were differentiated by FCM in all six examined strains. Significant changes were observed in the presence of the selected protectants. The addition of 20 mM sucrose in the simulated gastric fluid substantially increased the number of intact cells over 20 folds and reduced the damaged subpopulation by half. The presence of 2 % (w/v) lecithin vesicles was shown to protect 50 % more intact cells from the challenge of bile salts. The improved survival as evaluated by FCM analysis was further assessed for the proliferation capacity by sorting a number of cells from each subpopulation on nutrient agar plate. The result confirmed conformity between the proliferation-based cultivability and the probe-indicated viability in the samples of the intact and the damaged subpopulations. However, it also revealed the complexities of the stressed (injured) subpopulation. In conclusion, FCM analysis confirmed that the selected protectants could improve the survival of the probiotic strains in the simulated GI environments. The FCM analysis also proved to be a useful analytical tool for the probiotics research.