86 research outputs found

    Anti-atherogenic properties associated with the antioxidant activity from the hydrophilic extracts of Halimeda incrassata (Chlorophyta, Bryopsidales)

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    Seaweeds are a source of natural antioxidants having potential application in oxidative stress and associated diseases. In this work, anti-atherogenic properties associated with the antioxidant activity from the hydrophilic extracts of Halimeda incrassata were studied. The phenolic content assessed inthe aqueous extract and fraction phenolic acids (FPA) was 0.13 ± 0.05 and 0.47 ± 0.09 mg of gallic acid equivalents (GAE)/g dry seaweed, respectively. In DPPH?, radical scavenging assay fractions exhibited a dependent concentration. The seaweeds extract inhibited the desoxirribose oxidation in the presenceor absence of EDTA (IC50 = 1.91± 0.09 mg/mL) (IC50 = 2.95 ± 0.01 mg/mL). In vivo antioxidant properties of FPA-H.incrassata were investigated in rats with a CCl4-induced liver injury. Pre-treatment with H.incrassata led to approximately 50% reductions in liver TBARS levels. The treatment with H. incrassataFPA also increased the activity of the CAT enzyme, which in turn resulted in an enhanced antioxidantdefense. The expression of Catalase by PCR-RT technique demonstrated a higher gene expression when compared with that which was observed in the CCl 4-treated group. Antiatherogenic properties were studied in the inhibition of lipoprotein oxidation mediated by Cu2+ or HRP/H2O2, free radicalscavenging, and metal ion chelation, and it was dose dependent with a higher concentration needed for the aqueous extract than for the FPA fraction. Antioxidant activity was also improved in macrophages as evaluated in the cell supernatant (by TBARS formation); and by luminol enhanced chemiluminescence after cell activation with zymosan; and a degree of cell lipoperoxidation wasdecreased by the Halimeda incrassata extract. The results of this work add to the antioxidant potential of the seaweed for its application in oxidative stress associated conditions.Fil: Vidal-Novoa, Alexis. Universidad de la Habana. Facultad de Biología; CubaFil: Costa-Mugica, Ariadna. Universidad de la Habana. Facultad de Biología; CubaFil: Zulueta Díaz, Yenisleidy de Las Mercedes. Universidad de la Habana. Facultad de Biología; Cuba. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Diaz-Gutierrez, Daylín. Universidad de la Habana. Facultad de Biología; CubaFil: de Oliveira e Silva, Ana, Mara. Universidade de Sao Paulo; BrasilFil: Vazquez, Ana María. Center For Molecular Inmunology; CubaFil: Claudina, Zaldívar-Munoz. Universidad de la Habana. Facultad de Biología; CubaFil: Dalva, Assuncao Portari de Mancini. Institute Butantan Sao Paulo; BrasilFil: Mancini-Filho, Jorge. Universidade de Sao Paulo; Brasi

    EU methodology for critical raw materials assessment : policy needs and proposed solutions for incremental improvements

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    Raw materials form the basis of Europe's economy to ensure jobs and competitiveness, and they are essential for maintaining and improving quality of life. Although all raw materials are important, some of them are of more concern than others, thus the list of critical raw materials (CRMs) for the EU, and the underlying European Commission (EC) criticality assessment methodology, are key instruments in the context of the EU raw materials policy. For the next update of the CRMs list in 2017, the EC is considering to apply the overall methodology already used in 2011 and 2014, but with some modifications. Keeping the same methodological approach is a deliberate choice in order to prioritise the comparability with the previous two exercises, effectively monitor trends, and maintain the highest possible policy relevance. As the EC's in-house science service, the Directorate General Joint Research Centre (DG JRC) identified aspects of the EU criticality methodology that could be adapted to better address the needs and expectations of the resulting CRMs list to identify and monitor critical raw materials in the EU. The goal of this paper is to discuss the specific elements of the EC criticality methodology that were adapted by DG JRC, highlight their novelty and/or potential outcomes, and discuss them in the context of criticality assessment methodologies available internationally

    Effect of aqueous rosemary extract (Rosmarinus officinalis L.) on the oxidative stress of diabetic rats

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    OBJETIVO: Avaliar o efeito do extrato aquoso de alecrim sobre o estresse oxidativo em ratos diabéticos. MÉTODOS: O extrato aquoso de alecrim foi obtido por método sequencial. Os fenólicos totais foram determinados pelo método de Folin Ciocateau e a atividade antioxidante in vitro foi determinada através de três métodos: β-caroteno/ácido linoleico, varredura do radical 2,2 Difenil-1-Picril-hidrazil e oxigen radical absorbance capacity. Ratos Wistar machos foram distribuídos em 5 grupos: controle, diabético, e três grupos de animais diabéticos tratados com extrato aquoso de alecrim em concentrações diferentes: 25, 50 ou 100mg/kg por via oral durante 30 dias. O diabetes foi induzido por estreptozotocina e, no final do experimento, foi coletado sangue para avaliar o percentual de hemoglobina glicada e os tecidos hepático e cerebral para determinação das enzimas antioxidantes: superóxido dismutase, catalase, glutationa peroxidase e glutationa redutase. RESULTADOS: Constatou-se que o extrato aquoso de alecrim apresentou altos teores de compostos fenólicos totais e expressiva atividade antioxidante in vitro nos três métodos de avaliação. O extrato aquoso de alecrim na concentração de 50mg/kg diminuiu o percentual de hemoglobina glicada e aumentou a atividade das enzimas catalase e glutationa peroxidase no fígado, e da superóxido dismutase no cérebro de ratos diabéticos. No entanto, não foi observado efeito dose-resposta nas demais concentrações analisadas. CONCLUSÃO: O extrato aquoso de alecrim apresenta significativa capacidade antioxidante in vitro, atribuída à presença de compostos fenólicos em sua composição. E, quando administrado em ratos na concentração de 50mg/kg, demonstrou-se eficiente na atenuação do estresse oxidativo presente no diabetes experimental.OBJECTIVE: This study assessed the effect of aqueous rosemary extract on the oxidative stress of diabetic rats. METHODS: Aqueous rosemary extract was obtained by the sequential method. Total phenolic content was determined by the Folin Ciocateau method and antioxidant activity in vitro was determined by the following methods: β-carotene/linoleic acid, 2,2 Difenil-1-Picril-hidrazil and oxygen radical absorbance capacity. Male Wistar rats were distributed into 5 groups: control, diabetic, and three groups of diabetic animals treated with aqueous rosemary extract in different concentrations: 25, 50 or 100mg/kg orally for 30 days. Diabetes was induced by streptozotocin and, at the end of the experiment, blood was collected to assess the percentage of glycated hemoglobin; liver and brain tissues were collected for the determination of the antioxidant enzymes: superoxide dismutase, catalase, glutatione peroxidase and glutatione reductase. RESULTS: Aqueous rosemary extract contains high levels of phenolic compounds and significant total antioxidant activity in vitro according to the three methods. Aqueous rosemary extract at a concentration of 50mg/kg decreased the percentage of glycated hemoglobin and increased the activity of glutatiose peroxidase and catalase enzymes in the liver and superoxide dismutase in the brain of diabetic rats. However, no dose-response effect was observed in the other concentrations. CONCLUSION: Aqueous rosemary extract presented significant antioxidant capacity in vitro attributed to its high phenolic compound content. When administered to rats at a concentration of 50mg/kg, it proved to be efficient against the oxidative stress secondary to experimental diabetes

    Chemical composition and antioxidant activity of the red marine algae Bryothamnion triquetrum (S.G.Gmelin) Howe

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    En la actualidad existe un marcado interés por la búsqueda de antioxidantes de fuentes naturales, incluidas las algas marinas. El objetivo de este trabajo fue evaluar la composición química y propiedades antioxidantes del alga Bryothamnion triquetrum. Se estudió la composición centesimal y de minerales, identificación de ácidos grasos y sustancias antioxidantes. La composición centesimal es la siguiente: Proteínas (9,5%), Lípidos (1,3%), Carbohidratos (5,9%), Fibras (10,2%) y Cenizas (43%). Los resultados de la actividad antioxidante para las diferentes metodologías empleadas fueron: atrapamiento de radicales DPPH (38%, 4 mg de liofilizado), beta-Caroteno-Linoleico (12%, 4 mg de liofilizado), actividad atrapadora de radicales O2- (CI50 0,36 mg/mL), de radicales OH (CI50 2,11 mg/mL) y unión al Fe (CI50 0,37 mg/mL). Las propiedades antioxidantes de esta alga parecen explicarse por la capacidad atrapadora de radicales libres, particularmente relacionada con mecanismos de dismutación de radicales O2-, inactivación de radicales OH y quelación de Fe. En trabajos previos se identificaron ácidos cinámicos y fenólicos como moléculas que pudieran explicar la actividad antioxidante, sin embargo adicionalmente se debe considerar un efecto sumatorio y/o sinérgico de otros componentes antioxidantes del extracto, como los descritos en este trabajo, incluidos minerales, carotenoides y vitamina C.An increasing interest has been growing during the past years for the search of natural origin antioxidants, particularly those from marine algae. In this context, the main objective of current research was to evaluate the chemical composition and some antioxidant properties of the aqueous extract of the seaweed Bryothamnion triquetrum. The extracts contains: Proteins (9.5%), Lipids (1.3%), Carbohydrates (5.9%), Fibers (10.2%) and Ashes (43%). In current approach, the following results were obtained for the different procedures assessed: DPPH radicals scavenging (38% for 4 mg of lyophilized); beta-Carotene-Linoleic assay (12% for 4 mg of lyophilized); O2- radicals scavenging (IC50 0.36 mg/mL); OH radicals scavenging (IC50 2.11 mg/mL) and iron quelation ability (IC50 0.37 mg/mL). Thus, antioxidant properties of this natural product seem to be related to its ability to scavenge free species. In previous reports of our group, cinnamic and phenolic acids were proposed as at least partially responsible for the antioxidant properties of the extract, but the necessity for the presence of other components was also shown. Then, the antioxidant properties of the extract could be envisioned as the result of the additive and/or synergic effect between phenolic constituents and the other antioxidant components, such as minerals, carotenes and ascorbic acid

    Inhibition of LDL-oxidation and antioxidant properties related to polyphenol content of hydrophilic fractions from seaweed Halimeda Incrassata (Ellis) Lamouroux

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    LDL oxidation and oxidative stress are closely related to atherosclerosis. Therefore, natural antioxidants have been studied as promising candidates. In the present study, the LDL oxidation inhibition activity of bioactive compounds from Halimeda incrassata seaweed. associated to antioxidant capacity, was evaluated in vitro. Experimental work was conducted with lyophilized aqueous extract and phenolic-rich fractions of the seaweed and their effect on LDL oxidation was evaluated using heparin-precipitated LDL (hep-LDL) with exposure to Cu2+ ions and AAPH as the free radical generator. H. incrassata had a protective effect for hep-LDL in both systems and the presence of phenolic compounds contributed to the activity where phenolic-rich fractions showed significant capacity for inhibition of oxidation mediated by Cu2+ ions. The observed effect could be related to the antioxidant potential of polar fractions evidenced by reducing activity and DPPH center dot radical scavenging. The results obtained in vitro further support the antioxidant and LDL oxidation inhibition properties of H. incrassata and further knowledge toward future phytotherapeutic application of the seaweed.IFSIFS [F/4897-1]CIHR [MOP24447]CIHRCanadian Research Chair awardCanadian Research Chair awardGSEPGSEPCNPq (Brasil)CNPq- (Brasil

    L’influence des relations familiales et sociales sur la consommation de médicaments psychotropes chez les personnes âgées

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    Les psychotropes occupent le deuxième rang dans la consommation de médicaments chez les personnes âgées. L'objectif de cette étude est de vérifier un modèle explicatif de la consommation de psychotropes dans cette population. Notre principale hypothèse est que la qualité des relations qu'entretient une personne âgée avec autrui, et particulièrement avec ses enfants, a une influence directe sur son bien-être psychologique, lequel a une influence directe sur la non-consommation de psychotropes. Une enquête a été réalisée auprès d'un échantillon de 500 personnes âgées de 65 à 84 ans, vivant à domicile. Au cours des trois mois précédant l'entrevue, 31,8 % des répondants ont consommé des psychotropes. Les données empiriques n'ayant pas permis de vérifier le modèle théorique retenu, des analyses multivariées ont conduit à l'élaboration d'un modèle explicatif de la consommation qui met en évidence que le bien-être psychologique et la santé sont les meilleurs prédicteurs de cette consommation. Un bien-être psychologique élevé diminue la consommation alors qu'un mauvais état de santé l'augmente. Les relations sociales influencent directement le bien-être psychologique alors que les relations familiales ont un effet de moindre importance. Le modèle explicatif proposé explique 13 % du phénomène de la consommation de psychotropes chez les personnes âgées.Psychotropic drugs are the second most commonly used medication by Quebec's elderly. The objective of this study is to test a theoretical model of psychotropic drug use in the elderly. The principal hypothesis is that the quality of relationships the elderly person has with others, particularly with his or her children, has a direct influence on his or her psychological well-being, which, in turn, directly affects the consumption of psychotropic agents. A survey was conducted on a sample of 500 elderly people, aged 65-84 years, living at home. 31.8% of the respondents used psychotropic drugs during the three-month period preceding the interview. Path analysis led to the elaboration of a modified model for the consumption of psychotropic drugs by the elderly which indicates that the best predictors of consumption are both the psychological well-being and the state of health of the individual. More elevated is the psychological well-being, less is the consumption of psychotropic drugs, whereas poor health condition increases it. The quality of an individual's social relationships has a direct influence on his or her psychological well-being, whereas family relationships are of lesser importance. Our model accounts for 13% of the predictors of psychotropic consumption by the elderly

    Genome-wide expression profiling and functional characterization of SCA28 lymphoblastoid cell lines reveal impairment in cell growth and activation of apoptotic pathways

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    BACKGROUND: SCA28 is an autosomal dominant ataxia associated with AFG3L2 gene mutations. We performed a whole genome expression profiling using lymphoblastoid cell lines (LCLs) from four SCA28 patients and six unrelated healthy controls matched for sex and age. METHODS: Gene expression was evaluated with the Affymetrix GeneChip Human Genome U133A 2.0 Arrays and data were validated by real-time PCR. RESULTS: We found 66 genes whose expression was statistically different in SCA28 LCLs, 35 of which were up-regulated and 31 down-regulated. The differentially expressed genes were clustered in five functional categories: (1) regulation of cell proliferation; (2) regulation of programmed cell death; (3) response to oxidative stress; (4) cell adhesion, and (5) chemical homeostasis. To validate these data, we performed functional experiments that proved an impaired SCA28 LCLs growth compared to controls (p\u2009<\u20090.005), an increased number of cells in the G0/G1 phase (p\u2009<\u20090.001), and an increased mortality because of apoptosis (p\u2009<\u20090.05). We also showed that respiratory chain activity and reactive oxygen species levels was not altered, although lipid peroxidation in SCA28 LCLs was increased in basal conditions (p\u2009<\u20090.05). We did not detect mitochondrial DNA large deletions. An increase of TFAM, a crucial protein for mtDNA maintenance, and of DRP1, a key regulator of mitochondrial dynamic mechanism, suggested an alteration of fission/fusion pathways. CONCLUSIONS: Whole genome expression profiling, performed on SCA28 LCLs, allowed us to identify five altered functional categories that characterize the SCA28 LCLs phenotype, the first reported in human cells to our knowledge. \ua9 2013 Mancini et al.; licensee BioMed Central Ltd
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