Daily intake of a bean-fiber fortified bar reduces oxidative stress

as been proposed that the consumption of common beans (Phaseolus vulgaris L.) reduces cardiovascular risk, and prevents and controls both chronic and degenerative diseases. The aim of this study was to compare the antioxidant capacity of a bean-fiber fortified bar (BFB) versus a commercial bar (CB) in 60 Mexican men and women (18-65 years old), who were randomly distributed in two groups: BFB or CB; individuals consumed a bar a day for one month. Anthropometric data, food intake and blood samples were collected. Glucose tolerance (GTT), lipid profile (PL), and lipid peroxidation (TBARS) tests were performed; carbonyls groups in serum oxidized proteins were also measured. GTT and PL were not different between both groups in either the 15 or 30-day follow-up of bar consumption assessments. There were no significant differences in either TBARS or carbonyl concentration between groups; BFB group showed higher levels of serum lipid peroxidation in basal and fifteen days measurements; these levels decreased at the final evaluation: No differences were detected on carbonyl levels between groups. In conclusion, 30 days of fiber bean bar consumption did not alter glucose or PL levels, while, in the BFF group, oxidative stress decreased within 30 days of the consumption of the fortified bar(AU)

Se ha propuesto que el consumo de frijol común (Phaseolus vulgaris L.) reduce el riesgo cardiovascular, y previene y controla las enfermedades crónicas y degenerativas. El objetivo del presente estudio fue comparar la capacidad antioxidante de una barra fortificada con fibra de frijol (BFB) versus una barra comercial (CB) en 60 hombres y mujeres mexicanos (18-65 años de edad), quienes aleatoriamente fueron distribuidos en dos grupos: El grupo BFB y el CB que consumieron la barras fortificada con frijol y la barra comercial, respectivamente, durante un mes. Se recopilaron datos antropométricos, ingesta de alimentos y muestras de sangre. Se realizó prueba de tolerancia a la glucosa (GTT), el perfil de lípidos (PL), la peroxidación de lípidos (TBARS) y la cuantificación de carbonilos en proteínas oxidadas como pruebas de bioquímica sanguínea. GTT y PL no fueron diferentes entre ambos grupos en la evaluación de seguimiento de 15 y 30 días del consumo de la barra. No hubo diferencias significativas en los TBARS o la concentración de carbonilo entre los grupos, el grupo BFB mostró niveles más altos de peroxidación de lípidos en suero en la fase basal y a los quince días del consumo de la barra; curiosamente, estos niveles disminuyeron en la evaluación final. No se detectaron diferencias en los niveles de carbonilo entre los grupos. En conclusión, 30 días de consumo de barras de fibra de frijol no alteraron los niveles de glucosa o PL; mientras que, en el grupo BFB, el estrés oxidativo disminuyó a los 30 días del consumo de la barra fortificada(AU)

Changes in oxidative markers, endogenous antioxidants and activity of the enzyme acetylcholinesterase in farmers exposed to agricultural pesticides - a pilot study / Alterações em marcadores oxidativos, antioxidantes endógenos e na atividade da enzima acetilcolinesterase em trabalhadores rurais expostos a pesticidas agrícolas - um estudo piloto

Agricultural practices are directly related to the use of pesticides, which indiscriminately and without due care may contribute to the occurrence of numerous intoxications. Several studies have demonstrated the relationship of certain pesticides and the occurrence of oxidative stress and therefore, in recent years have developed methods of analysis of several biomarkers of cellular damage that can be measured and quantified. In this context, the objective of this study was to evaluate the possible changes in biochemical markers: glutamic aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, urea, total protein, and oxidative markers such as lipid peroxidation, damage to proteins and the activity of the enzymes acetylcholinesterase (AChE) and catalase (CAT) in farmers exposed to different pesticides for at least five years from Ibirubá - RS city. With the exception of AST and ALT, the results showed a significant difference between the mean total protein, urea and creatinine in the control group, showing that no changes in liver or kidney function of rural workers. In the oxidative parameters, there was a decrease in AChE activity and CAT in the control group; there were an increase in protein carbonyl and a decreased on TBARS compared to control group. Therefore, the results demonstrated a change in oxidative status of rural workers compared with the control group, mainly by possible inhibition of AChE activity and the occurrence of oxidative stress without showing changes in biochemical parameters.

As práticas agrícolas estão diretamente relacionadas com o uso de agrotóxico, que, de forma indiscriminada e sem o devido cuidado, podem contribuir para a ocorrência de inúmeras intoxicações. Diversos estudos demonstraram a relação de determinados pesticidas e a ocorrência do estresse oxidativo e, portanto, nos anos recentes, tem-se desenvolvido métodos de análise de diversos biomarcadores de dano celular, o qual pode ser medido e quantificado. Nesse contexto, o objetivo deste estudo foi avaliar as possíveis alterações nos marcadores bioquímicos: aspartato aminotransferase (AST), alanina aminotransferase (ALT), creatinina, ureia, proteína total, e marcadores oxidativos como: a peroxidação de lipídios, danos nas proteínas e a atividade das enzimas acetilcolinesterase (AChE) e catalase (CAT), em agricultores da cidade de Ibirubá, RS, expostos a diferentes agrotóxicos por pelo menos cinco anos. Com exceção da AST e da ALT, os resultados mostraram diferença significativa entre as médias das proteínas totais, ureia e creatinina, no grupo controle, mostrando que não houve alterações na função hepática ou renal dos trabalhadores rurais. Nos parâmetros oxidativos avaliados, houve uma diminuição da atividade da AChE e da CAT em relação ao grupo controle; um aumento das proteínas carboniladas e uma diminuição dos níveis de TBARS em relação ao grupo controle. Portanto, os resultados demonstram uma alteração oxidativa nos trabalhadores rurais, comparados com o grupo controle, principalmente pela possível inibição da AChE e ocorrência do estresse oxidativo, sem demonstrar mudança nos parâmetros bioquímicos analisados.

Oxidative stress parameters as biomarkers of risk factor for diabetic foot among the patients with type 2 diabetes

The aim of this study was to determine whether plasma levels of carbonylated proteins, total antioxidant capacity (TAC) and reduced protein thiols could be suitable biomarkers of risk factors for diabetic foot. Individuals with type 2 diabetes with normal protective sensation (normal foot group) vs. loss of protective sensation and/or signs of peripheral arterial disease and/or foot deformities and/or history of ulcers and/or neuropathic fractures and/or amputation (diabetic foot group) were compared. The diabetic foot group showed higher carbonylated protein levels (P = 0.0457) and lower levels of TAC (P = 0.0148) and reduced protein thiols (P = 0.0088), compared with the normal foot group. In general, several other parameters of risk of diabetes complication (blood levels of glycated hemoglobin, glucose and cholesterol, duration of diabetes, body mass index and waist circumference) showed a tendency of higher values in the diabetic foot group. The results suggest that the plasma levels of carbonylated proteins, TAC and reduced protein thiols could furnish information about the risk of diabetic foot, considering that the changes in these biomarkers were associated with the loss of sensitivity and foot ulcerations.

Mecanismo de oxidação aeróbica de acetoacetato e 2-metilacetoacetato catalisada por mioglobina: implicações em desordens cetogênicas / Mechanism of the aerobic oxidation of acetoacetate and 2- methylacetoacetate catalyzed by Mb: implications for ketogenic disorders

Acetoacetato (AA) e 2-metilacetoacetato (MAA) são compostos β-cetoácidos acumulados em diversas desordens metabólicas como no diabetes e na isoleucinemia, respectivamente. Examinamos o mecanismo de oxidação aeróbica de AA e MAA iniciada por intermediários reativos de mioglobina de coração de cavalo (Mb) gerados pela adição de H2O2. Uma rota quimioluminescente que envolve um intermediário dioxetânico cuja termólise gera espécies α-dicarbonílicas (metilglioxal e biacetilo) foi proposta e estudada. Emissão de luz ultra fraca acompanha a reação, e sua intensidade aumenta linearmente pelo aumento da concentração tanto de Mb (10-500 µM) quando AA (10-100 mM). Estudos de consumo de oxigênio mostraram que MAA é, como esperado, quase uma ordem de grandeza mais reativo que AA. Estudos de EPR com captação de spin, utilizando MNP, possibilitaram detectar adutos de MAA atribuíveis a um radical centrado no Cα (aN = 1.55 mT) e ao radical acetila (aN = 0.83 mT). O sinal do radical acetila é totalmente suprimido por sorbato, um conhecido e eficiente supressor de espécies tripletes, o que é consistente com uma rota reacional envolvendo um intermediário dioxetânico. Clivagem-α da ligação carbonila-carbonila do produto biacetilo triplete produziria, de fato, radicais acetila. Além disso, utilizando AA como substrato para Mb/H2O2, um sinal de EPR atribuível ao aduto MNP-AA• (aN = 1.46 mT e aH = 0.34 mT) foi observado e confirmado por efeito isotópico. O consumo de oxigênio e o rendimento de compostos α-dicarbonílicos foram dose-dependentes à concentração de AA ou MAA (1-50 mM) bem como à concentração de H2O2 adicionado às misturas de reação contendo Mb (até 1:10 quando medido o consumo de oxigênio, e até 1:25 quando medido o rendimento de compostos α-dicarbonílicos) e tert-butilhidroperóxido (até 1:200). Os perfis de pH (5,8-7,8) para consumo de oxigênio e rendimento de compostos α-dicarbonílicos mostraram maiores rendimentos para baixos valores de pH, indicativo de ferrilMb...

Acetoacetate (AA) and 2-methylacetoacetate (MAA) are β-ketoacids accumulated in several metabolic disorders such as diabetes and isoleucinemia, respectively. Here we examine the mechanism of AA and MAA aerobic oxidation initiated by the reactive enzyme intermediates formed by the reaction of muscle horse myoglobin (Mb) with H2O2. A chemiluminescent route involving a dioxetane intermediate whose thermolysis yields triplet α-dicarbonyl species (methylglyoxal and diacetyl) is envisaged. Accordingly, the ultraweak light emission that accompanies the reaction increases linearly by raising the concentration of both Mb (10-500 µM) and AA (10- 100 mM). Oxygen uptake studies revealed that MAA is, expectedly, almost one order of magnitude more reactive than AA. EPR spin-trapping studies with MNP detected spin adducts from MAA attributable to an α-carbon-centered radical (aN = 1.55 mT) and to an acetyl radical (aN = 0.83 mT). As the acetyl radical signal is totally suppressed by sorbate, a well-known efficient triplet species quencher, the dioxetane hypothesis seems to be reliable. The α-cleavage of the carbonyl-carbonyl bond of a putative excited triplet diacetyl product would, in fact, leads to an acetyl radical. Furthermore, using AA as substrate for Mb/H2O2, an EPR signal assignable to a MNP-AA• adduct (aN = 1.46 mT and aH = 0.34 mT) was observed and confirmed by isotope effect. Oxygen consumption and α-dicarbonyl yield were also dependent on AA or MAA concentrations (1-50 mM) as well as on the concentration of peroxide added to the Mb-containing reaction mixtures: H2O2 (up to 1:10 when measuring oxygen uptake and up to 1:25 when measuring the α-dicarbonyl yield) and t-butOOH (up to 1:200). The pH profiles (5.8-7.8) of oxygen consumption and α-dicarbonyl yield show higher reaction rates at lower pHs, indicative of a ferrylMb intermediate. Evaluating Mb lesion, both β-ketoacids reduced disorganization of the secondary and tertiary protein structure elicited by H2O2...

Emissões de poluentes não legislados por biodiesel / Emissions of non-criteria biodiesel pollutants

Seguindo uma tendência mundial, especialmente na Europa, o governo brasileiro autorizou a partir de 2005 o uso de 2% de biodiesel por veículos pesados. Este nível foi incrementado para 3% em 2008, quando estará autorizado o uso de 5% de biodiesel, que será definitivamente implementado pela frota em 2013. Diversos estudos identificaram que o biodiesel emite menores níveis de dióxido de carbono, óxidos de enxofre e material particulado. Entretanto, algumas classes de poluentes, como os compostos orgânicos voláteis (COVs) são carentes de dados. As emissões destes compostos não pode ser medida pelos equipamentos comerciais disponíveis usados pelas agências ambientais, que apenas quantificam os hidrocarbonetos de forma totalizada. Este trabalho fez uma avaliação das emissões de poluentes não legislados, como carbonilas, hidrocarbonetos aromáticos e policíclicos aromáticos e mercaptanas. Os testes foram conduzidos em dois motores diesel de seis cilindros, dentre os mais usados pelos ônibus urbanos no Brasil. Os teores de biodiesel testados foram 2, 5, 10 e 20% v/v de biodiesel (B2, B5, B10 e B20), e também com diesel puro (D). Os resultados indicaram um aumento nas emissões de carbonilas, com exceção do benzaldeído. As emissões de hidrocarbonetos monoaromáticos tiveram uma redução média de 4,7% para B2, 8,7% para B5 e 21,5% para B20. Para os hidrocarbonetos policíclicos aromáticos obteve-se reduções para B2, B5 e B20 de 2,7%, 6,3% e 17,2%, respectivamente. As emissões de mercaptanas também apresentaram redução em função do aumento do teor de biodiesel.

Following a worldwide trend, mainly in Europe, Brazilian government authorized since 2005 the use of 2% of biodiesel by heavy duty vehicles. This level was increased to 3% in 2008, when it will be authorized the use of 5% of biodiesel, which will be implemented in all of our fleet of vehicles in 2013. Several studies identified that biodiesel emits lower levels of carbon dioxide, sulfur dioxides and particulate matter. However, some classes of pollutants as volatile organic compounds (VOCs) lack of this kind of data. The emissions of these pollutants can not be identified by the commercial on-line equipments used by the environmental agencies; they only analyze the total quantities of these compounds. This study has done an evaluation of some non-criteria pollutants, as carbonyls, monoaromatic and polycyclic aromatic hydrocarbons, and mercaptans. Emission tests were done using two six cylinders diesel engines, commonly used by the urban buses in Brazil, that were tested with 2, 5, 10, and 20% v/v of biodiesel (B2, B5, B10, and B20), as well as with plain diesel (D). The results indicated an increase on the carbonyls emissions, with exception of benzaldehyde. The monoaromatic hydrocarbon emissions exhibit a reduction of 4.7% for B2, 8.7% for B5, and 21.5% for B20. For the polycyclic aromatic compounds the emissions reduction for B2, B5, and B20 were 2.7%, 6.3%, and 17.2%, respectively. The emissions of mercaptans also exhibit a reduction with the biodiesel content.

Cysteine and arginine in plasma albumin are the major targets attacked by free radicals / 中华肾脏病杂志

Objective To study the effects of oxidants on the structure of albumin. Methods Using both AOPPs and protein carbonyl content as indices. The oxidative stress level in normal controls and uremia patients was evaluated. Albumin in plasma was purified by HPLC and then was subjected to amino acids composition assay. Results Both AOPPs level and protein carbonyl content in uremic patients were significantly higher than those in controls (P