Antioxidant capacity of protein hydrolysates and phenolic compounds of flaxseed (Linum usitatissimum L.) and its modulatory effects on experimental colitis

Orientador: Flávia Maria NettoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: As proteínas da linhaça, assim como outras proteínas de origem vegetal, estão naturalmente associadas aos compostos fenólicos. Durante a hidrólise enzimática dessas proteínas, peptídeos e compostos fenólicos são liberados e podem exercer atividades antioxidante e anti-inflamatória. Este estudo avaliou a influência do complexo proteína-fenólico e da hidrólise com Alcalase e/ou enzimas digestivas sobre a capacidade antioxidante (CA) de produtos de linhaça. Investigou-se também a capacidade anti-inflamatória dos hidrolisados proteicos e compostos fenólicos da linhaça in vitro, pela inibição da produção de mediadores inflamatórios em macrófagos estimuladas por IFN-?/LPS e, in vivo, por meio da modulação da inflamação em animais com retocolite ulcerativa induzida por TNBS. O isolado proteico de linhaça (FPI) foi obtido a partir da farinha de linhaça desengordurada por extração alcalina (pH 9,0) e precipitação no ponto isoelétrico (pH 4,2) seguida de neutralização (pH 6,0). O hidrolisado de proteína de linhaça (FPH) foi produzido a partir da hidrólise do FPI com Alcalase. Para obter o isolado e hidrolisado proteico de linhaça com reduzido teor fenólico (phr-FPI e phr-FPH, respectivamente) a farinha de linhaça desengordurada foi lavada com etanol antes do processo de isolamento, para remoção da fração fenólica (Phi). A fração fenólica hidrolisada (Phh) foi obtida submetendo-se a Phi às mesmas condições de pH e temperatura utilizadas na hidrólise dos isolados proteicos. A análise de fluorescência intrínseca foi utilizada para avaliar a formação do complexo proteína: fenólico e a CA foi determinada pelos métodos ORAC e FRAP. As amostras Phi e Phh apresentam a maior CA seguida dos hidrolisados e isolados proteicos. A presença de compostos fenólicos nas amostras proteicas foi responsável pelo aumento de até 80% na CA do isolado proteico, medida pelos métodos ORAC e FRAP, enquanto que para o hidrolisado proteico ela foi responsável por um aumento de 15% da CA medida por ORAC, e 80%, quando medida por FRAP. Após a simulação da digestão, a CA dos isolados e hidrolisados proteicos aumentou e a influência dos compostos fenólicos na capacidade antioxidante persistiu, especialmente quando determinada por FRAP. Nossos resultados sugerem que CA de isolados deve-se principalmente à formação do complexo proteína:fenólico, enquanto que nos hidrolisados a CA deve-se possivelmente ao sinergismo entre fenólicos e peptídeos liberados a partir da hidrólise com Alcalase ou com as enzimas digestivas. Além disso, a transferência de H+ parece ser o principal mecanismo pelo qual as proteínas de linhaça atuam como antioxidantes. Em relação à capacidade antioxidante do phr-FPH, foram identificados quatro sequências de peptídeos usando LC-MS/MS e uma sequência foi identificada por degradação de Edman (GFPGRLDHWCASE) a qual apresentou CA maior do que a do antioxidante sintético BHA. Em relação ao efeito anti-inflamatório, as amostras Phi, Phh, FPH e phr-FPH foram capazes de inibir a produção de NO e TNF-? em macrófagos estimulados com IFN-?/LPS. No estudo in vivo, Phi e phr-FPH foram capazes de atenuar a perda de peso dos animais, as respostas inflamatórias das células TH1 e TH17, a proliferação de linfócitos TCD4+ e os níveis de citocinas inflamatórias em animais com retocolite induzida por TNBS. De forma geral os resultados demonstram que os hidrolisados proteicos e os compostos fenólicos da linhaça possuem atividade antioxidante e anti-inflamatória. Mais estudos são necessários para avaliar a interferência do complexo proteína:fenólico na biodisponibilidade de peptídeos e fenólicos, e a relação destes compostos com a microbiota intestinal para conhecer a real capacidade destes produtos em fornecer benefícios ao organismoAbstract: Flaxseed protein is a potential source of bioactive compounds. During the enzymatic hydrolysis of vegetable proteins, peptides and phenolic compounds, which are associated with proteins, are released and may act as antioxidants and anti-inflammatory. This study evaluated the influence of the hydrolysis with Alcalase and simulated gastrointestinal digestion on the antioxidant capacity of different flaxseed products. We also evaluated the inhibitory capacity of flaxseed protein hydrolysates and phenolic fractions on the production of inflammatory mediators by stimulated macrophages and the anti-inflammatory effects on TNBS-induced colitis. The Flaxseed protein hydrolysate (FPH) was produced with protein isolate obtained from defatted meal by alkaline extraction (pH 9.0) followed by precipitation (pH 4.2) and neutralization (pH 6.0). In order to obtain phenolic reduced flaxseed protein hydrolysate (phr-FPH), flaxseed was extracted from defatted meal with ethanol before isolating process. The hydrolysis was performed with Alcalase (pH 8.5; enzyme/substrate 1/90, w/w). Hydrolysed phenolics compounds (Phi) was obtained with the phenolics compounds extracted from the defatted flaxseed meal using the same conditions of protein hydrolysis. Four glycosylated phenolic compounds ¿ secoisolariciresinol and ferulic, p-coumaric, caffeic acids ¿ were identified using HPLC-MS/MS. Intrinsic fluorescence was used to analyze protein:polyphenol complex. A chromatographic characterization of the samples was performed and the AC was determined by FRAP and ORAC methods. A chromatographic separation of the phr-FPH by RP-HPLC was performed, and the AC of the six obtained fractions was determined. Flaxseed phenolic fractions exhibit the highest antioxidant capacity followed by flaxseed protein hydrolysates and isolates. The presence of phenolic compounds increased 80% of antioxidant capacity of the protein isolate, measured by ORAC and FRAP methods, while for the hydrolysates accounted for 15% measured by ORAC, and 80% when measured by FRAP. After simulated digestion, the antioxidant capacity of isolates and hydrolysates increased and the influence of phenolics on their antioxidant capacity persisted, especially when determined by FRAP. Our findings suggest that AC of isolates is mainly due to the protein: phenolic complex while in the hydrolysates is mainly by the synergism between phenolics and peptides released by Alcalase or simulated digestion. Also, the preferential mechanism that flaxseed protein may act as antioxidant is the H+ atom transfer. Four peptide sequences could be identified by using LC-MS/MS and one by Edman degradation. The peptide sequence GFPGRLDHWCASE was synthesized and showed a value higher than that of butylated hydroxyanisole. The identified sequences represent an advance in the molecular characterization of the flaxseed protein fraction. Regarding to the anti-inflammatory effect of flaxseed extracts, Phi, Phh, FPH and phr-FPH inhibit NO and TNF-? secretion in stimulated RAW cells and also downregulating weight loss, histological inflammation, TH1 and TH17 responses, T cell proliferation and inflammatory cytokine levels on TNBS-induced colitis in BALB/c mice. Together, the results demonstrate that flaxseed protein hydrolysates and phenolic isolated fractions had antioxidant activity and protective effects on a TNBS-induced colitis model. More studies are needed to evaluate the effect of the protein complex: phenol in the bioavailability of peptides and phenolics, and the relationship of these compounds with the intestinal microbiota to know the real ability of these products to provide health benefitsDoutoradoNutrição Experimental e Aplicada à Tecnologia de AlimentosDoutora em Alimentos e Nutrição2010/52680-7FAPES

Scientific sketching as a partner in the conservation of the Cerrado Biome

Tradução de / Translated by Professor José Augusto Drummond Ph. D., Center for Sustainable Development, University of Brasilia.Quando se fala de ilustração científica, a reação que temos é de, no mínimo, perplexidade. Alguns imaginam que se trata de uma área extinta ou em vias de extinção. Outros nem sabem do que se trata, principalmente fora do meio acadêmico. Mas, repassemos um pouco de história, para ver que nós, ilustradores científicos, somos herdeiros de uma tradição secular.Nowadays, when somebody mentions scientific sketching, most people will be perplexed, at the least. Some will even think that it is an extinct – or all but extinct – undertaking. Others will not have a clue about what it is, especially if they do not belong to academic or scientific circles. However, a bit of history lets us see that scientific sketchers are the inheritors of a multi-secular tradition

Morphological convergence in a Mexican garter snake associated with the ingestion of a novel prey

Morphological convergence is expected when organisms which differ in phenotype experience similar functional demands, which lead to similar associations between resource utilization and performance. To consume prey with hard exoskeletons, snakes require either specialized head morphology, or to deal with them when they are vulnerable, for example, during molting. Such attributes may in turn reduce the efficiency with which they prey on soft-bodied, slippery animals such as fish. Snakes which consume a range of prey may present intermediate morphology, such as that of Thamnophiine (Natricinae), which may be classified morphometrically across the soft–hard prey dietary boundary. In this study, we compared the dentition and head structure of populations of Thamnophis melanogaster that have entered the arthropod–crustacean (crayfish)-eating niche and those that have not, and tested for convergence between the former and two distantly related crayfish specialists of the genus Regina (R. septemvittata and R. grahamii). As a control, we included the congener T. eques. Multivariate analysis of jaw length, head length, head width, and number of maxillary teeth yielded three significant canonical variables that together explained 98.8% of the variance in the size-corrected morphological data. The first canonical variable significantly discriminated between the three species. The results show that head dimensions and number of teeth of the two Regina species are more similar to those of crayfish-eating T. melanogaster than to non-crayfish- eating snakes or of T. eques. It is unclear how particular head proportions or teeth number facilitates capture of crayfish, but our results and the rarity of soft crayfish ingestion by T. melanogaster may reflect the novelty of this niche expansion, and are consistent with the hypothesis that some populations of T. melanogaster have converged in their head morphology with the two soft crayfish-eating Regina species, although we cannot rule out the possibility of a morphological pre-adaptation to ingest crayfish.Universidad Autónoma del Estado de México: 2865/2010 and 2663/201

Synthesis of new, single-isomer quaternary ammonium derivatives of beta-cyclodextrin for electrophoretic enantiomer separations

The isolation of individual enantiomers of drugs is an important subject of interest in the pharmaceutical and medical fields, because stereochemistry can have a significant effect on the biological activity of the drug. Therefore, it is important to develop enantiomeric separation methods for the determination of the optical purity of drugs, since the undesired enantiomer is regarded as one of the impurities. The available single isomer anionic cyclodextrins (CD) can resolve the enantiomers of only a few weakly acidic analytes. To rectify this problem, the chloride salts of heptakis(6-deoxy-6-morpholinio)-cyclomaltoheptaose (HMBCD), and mono(6- deoxy-6-N,N,N r,N r,N r-pentamethylethylenediammonio)-cyclomaltoheptaose (PEMEDA-BCD), the first members of the permanently charged, single-isomer cationic cyclodextrin family, have been synthesized. The purity of process intermediates and final products was determined by HPLC-ELSD and indirect UV-detection capillary electrophoresis. Structural identity was verified by 1D and 2D NMR and massBoth cationic CD derivatives have been used for the separation of the enantiomers of strong acid, weak acid, weak base, ampholytic, and neutral analytes by capillary electrophoresis. Because the charge state of these cationic chiral resolving agents is independent of the pH of the buffer, separation could be performed in both low and high pH buffers without compromising the charge density of the resolving agent. Contrary to expectation, the multiply charged HMBCD showed poor complexation with the newly synthesized strong electrolyte test analytes. The weak binding between the analytes and HMBCD resulted in separation of enantiomers of only three strong electrolyte analytes. Strong complexation was observed between PEMEDA-BCD and the anionic and nonionic analytes in both low and high pH buffers, though complexation was stronger in the high pH buffer. Due to strong complexation between the anions and PEMEDA-BCD, only low concentrations of the resolving agent were required to effect good enantiomer resolutions. spectrometry

Perturbation theory vs. simulation for tadpole improvement factors in pure gauge theories

We calculate the mean link in Landau gauge for Wilson and improved SU(3) anisotropic gauge actions, using two loop perturbation theory and Monte Carlo simulation employing an accelerated Langevin algorithm. Twisted boundary conditions are employed, with a twist in all four lattice directions considerably improving the (Fourier accelerated) convergence to an improved lattice Landau gauge. Two loop perturbation theory is seen to predict the mean link extremely well even into the region of commonly simulated gauge couplings and so can be used remove the need for numerical tuning of self-consistent tadpole improvement factors. A three loop perturbative coefficient is inferred from the simulations and is found to be small. We show that finite size effects are small and argue likewise for (lattice) Gribov copies and double Dirac sheets.Comment: 13 pages of revtex

Congenital feeding response to a novel prey in a Mexican gartersnake.

Articulo de investigación científica publicado en revista indizadaIn this study, we explored chemosensory, ingestive and prey-catching responses of neonate Mexican Black-bellied Gartersnakes (Thamnophis melanogaster) to crayfish (Cambarellus montezumae). By comparing snakes from a recently discovered crayfisheating population and a typical non-crayfish-eating population, we asked which behavioral components change as a species enlarges its feeding niche. In the crayfisheating population chemosensory responsiveness to crayfish was not enhanced but its heritability was higher. Neonates of both populations showed similar preference for freshly-molted versus unmolted crayfish, and whereas the tendency to ingest both crayfish stages remained stable between ages 15 and 90 days in the non-crayfisheating population, in the crayfish-eating population it actually decreased. Techniques to catch and manipulate molted crayfish were similar in the two populations. We discuss the possibility that there is no increase in the behavioral response to eat crayfish by the neonates of the crayfish-eating populations, possibly due to the absence of ecological and spatial isolation between the two T. melanogaster populations. The crayfish ingestion in some population of T. melanogaster can be explained by environmental differences between populations, or by recent origin of crayfish ingestion in T. melanogaster.Universidad Autónoma del Estado de México (3589/2013SF, 4047/2016SF, 4865/2019SF)

A confiabilidade da memória como prova no processo penal : falsas memórias e seus desdobramentos

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Faculdade de Direito, 2018.Este trabalho propõe uma análise de como a memória pode ser frágil, corruptível e inconsistente, e como essas características atribuídas à memória podem influenciar em processos em que a lembrança é a principal prova do fato ocorrido. A presente pesquisa pode ser dividida em três partes: a primeira é uma introdução a memória propriamente dita, seus aspectos biológicos e as falhas que podem ocorrer a partir da tentativa de recordar os mais diversos eventos; a segunda parte do trabalho é formada por considerações sobre aspectos relevantes do processo penal, características importantes para contextualizar a problemática das falsas memórias dentro do processo e, por fim, busca-se demonstrar as variáveis que geram a falta de confiabilidade da prova fundada na memória.This work proposes an analysis of how memory can be fragile, corruptible and inconsistent, and how these characteristics attributed to memory can influence processes in which memory is the main proof of the fact. The present research can be divided into three parts: the first is an introduction to memory itself, its biological aspects and the failures that can occur from the attempt to remember the most diverse events; the second part of the work is formed by considerations about relevant aspects of the criminal process, important characteristics to contextualize the problematic of the false memories within the process and, finally, it is sought to demonstrate the variables that generate the lack of reliability of the evidence founded in the memory

Mortalidad de hombres jóvenes por agresiones en Brasil, 2010-2014 : estudio ecológico

O objetivo foi analisar a associação entre o risco de morte por agressões em jovens do sexo masculino e características sociodemográficas dos municípios brasileiros. Estudo ecológico tendo como unidades de análise os 1.651 municípios com mais de 20.000 habitantes. Foram utilizados dados do Sistema de Informação sobre Mortalidade (SIM) e indicadores obtidos do Censo Demográfico 2010 e do Atlas do Desenvolvimento Humano no Brasil. Razões de taxas de mortalidade foram estimadas por modelo de regressão binomial negativa. No período de 2010-2014, foram registrados 127.137 óbitos por agressão a jovens de 15-29 anos de idade do sexo masculino. A taxa corrigida de mortalidade foi 133,3/100 mil habitantes no conjunto dos municípios (mediana 71,5/100 mil habitantes). A taxa foi maior à medida que aumentou o porte populacional dos municípios. Razões de taxas mais elevadas no modelo ajustado foram observadas nos municípios mais urbanizados (1,95; IC95%: 1,70-2,23), em categorias intermediárias de desigualdade de renda (1,10; IC95%: 1,01-1,20) e proporção de pobreza (1,69; IC95%: 1,51-1,89), com menor proporção de jovens frequentando o Ensino Médio (2,05; IC95% 1,83-2,30), maior proporção de jovens de 18-24 anos desocupados (1,27; IC95%: 1,16-1,40) e maior número de mulheres em relação ao de homens (1,28; IC95% 1,05-1,58). A mortalidade de jovens do sexo masculino por agressão foi elevada, especialmente nos municípios maiores, mais urbanizados e com maior proporção de jovens buscando emprego e fora do ensino médio. Evidencia-se a relevância das políticas sociais para o enfrentamento da violência entre jovens.The aim was to analyze the association between risk of death from assault in young males and socio-demographic characteristics in Brazilian municipalities. In this ecological study, the units of analysis were the 1,651 municipalities of Brazil with more than 20,000 inhabitants. Data were obtained from the Brazilian Mortality Information System (SIM) and indicators were obtained from the 2010 Population Census and Human Development Atlas. Mortality rate ratios were estimated by a negative binomial regression model. From 2010 to 2014, a total of 127,137 deaths from assault were reported in young males 15 to 29 years of age. Corrected mortality rate was 133.3/100 thousand inhabitants for the set of municipalities (median 71.5/100 thousand inhabitants). The rate increased with the municipalities’ population size. In the adjusted model, higher rates ratios were observed in the more urbanized municipalities (1.95; 95%CI: 1.70-2.23), in intermediate categories of income inequality (1.10; 95%CI: 1.01-1.20) and poverty rate (1.69; 95%CI: 1.51-1.89), with lower proportion of youth attending Secondary School (2.05; 95%CI: 1.83-2.30), with higher proportion of unemployed youth 18 to 24 years of age (1.27; 95%CI: 1.16-1.40), and with more women than men (1.28; 95%CI: 1.05-1.58). Mortality from assault was high in young Brazilian men, especially in larger and more urbanized municipalities and those with a higher proportion of youth looking for work and not attending secondary school. The results show the relevance of social policies for dealing with violence against youth.El objetivo fue analizar la asociación entre el riesgo de muerte por agresiones en jóvenes del sexo masculino y características sociodemográficas de los municipios brasileños. Estudio ecológico teniendo como unidades de análisis los 1.651 municipios con más de 20.000 habitantes. Se utilizaron datos del Sistema de Información sobre Mortalidad (SIM) e indicadores obtenidos del Censo Demográfico 2010 y del Atlas de Desarrollo Humano. Las razones de tasas de mortalidad se estimaron por el modelo de regresión binomial negativa. En el período de 2010-2014, se registraron 127.137 óbitos por agresión a jóvenes de 15-29 años de edad del sexo masculino. La tasa corregida de mortalidad fue de 133,3/100 mil habitantes en el conjunto de los municipios (mediana 71,5/100 mil habitantes). La tasa fue mayor, a medida que aumentó el porte poblacional de los municipios. Razones de tasas más elevadas en el modelo ajustado se observaron en los municipios más urbanizados (1,95; IC95%: 1,70-2,23), en categorías intermedias de desigualdad de renta (1,10; IC95%: 1,01-1,20) y proporción de pobreza (1,69; IC95%: 1,51-1,89), con menor proporción de jóvenes frecuentando la Enseñanza Media (2,05; IC95%: 1,83-2,30), mayor proporción de jóvenes de 18-24 años desocupados (1,27; IC95%: 1,16-1,40) y mayor número de mujeres en relación a hombres (1,28; IC95%: 1,05-1,58). La mortalidad de jóvenes del sexo masculino por agresión fue elevada, especialmente en los municipios mayores, más urbanizados y con mayor proporción de jóvenes buscando empleo y fuera de la enseñanza media. Se evidencia la relevancia de las políticas sociales para el enfrentamiento de la violencia entre jóvenes

Sleep apnea and atrial fibrillation - A different kind of rhythm

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