208 research outputs found

    Antioxidant activity of Moringa oleifera tissue extracts

    Get PDF
    Moringa oleifera is an important source of antioxidants, tools in nutritional biochemistry that could be beneficial for human health; the leaves and flowers are used by the population with great nutritional importance. This work investigates the antioxidant activity of M. oleifera ethanolic (E1) and saline (E2) extracts from flowers (a), inflorescence rachis (b), seeds (c), leaf tissue (d), leaf rachis (e) and fundamental tissues of stem (f). The radical scavenging capacity (RSC) of extracts was determined using dot-blots on thin layer chromatography stained with a 0.4 mm 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) solution; spectrophotometric assays were recorded (515 nm). Antioxidant components were detected in all E1 and E2 from a, b and d. The best RSC was obtained with E1d; the antioxidants present in E2 reacted very slowly with DPPH. The chromatogram revealed by diphenylborinate-2-ethylamine methanolic solution showed that the ethanolic extract from the flowers, inflorescence rachis, fundamental tissue of stem and leaf tissue contained at least three flavonoids; the saline extract from the flowers and leaf tissue revealed at least two flavonoids. In conclusion, M. oleifera ethanolic and saline extracts contain antioxidants that support the use of the plant tissues as food sources.The authors acknowledge financial support from the Portuguese Fundacao para Ciencia e a Tecnologia (FCT) by the Post-doctoral grant SFRH/BPD/37349/2007. The Brazilian Programmes Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for research grants and fellowships (PMGP and LCBBC) and the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) are acknowledged for financial support

    EFFECT OF RELATIVE REINFORCEMENT DURATION IN CONCURRENT SCHEDULES WITH DIFFERENT REINFORCEMENT DENSITIES: A REPLICATION OF DAVISON (1988)

    Get PDF
    Previous studies have challenged the prediction of the Generalized Matching Law about the effect of relative, but not absolute, value of reinforcement parameters on relative choice measures. Six pigeons were run in an experiment involving concurrent variable-interval schedules with unequal reinforcer durations associated with the response alternatives (10 s versus 3s), a systematic replication of Davison (1988). Programmed reinforcement frequency was kept equal for the competing responses while their absolute value was varied. Measures of both response ratios and time ratios showed preference for the larger duration alternative and that preference did not change systematically with changes in absolute reinforcer frequency. Present results support the relativity assumption of the Matching Law. It is suggested that Davison’s results were due to uncontrolled variations in obtained reinforcement frequency. Keywords: choice, preference, overall reinforcer frequency, reinforcer magnitude, pigeons.

    Non-pharmacological treatment-related changes of molecular biomarkers in major depressive disorder: A systematic review and meta-analysis

    Get PDF
    Background Major depressive disorder (MDD) is a serious mood disorder and leading cause of disability. Despite treatment advances, approximately 30% of individuals with MDD do not achieve adequate clinical response. Better understanding the biological mechanism(s) underlying clinical response to specific psychopharmacological interventions may help fine tune treatments in order to further modulate their underlying mechanisms of action. However, little is known regarding the effect of non-pharmacological treatments (NPTs) on candidate molecular biomarker levels in MDD. This review aims to identify molecular biomarkers that may elucidate NPT response for MDD. Methods We performed a systematic review and a multilevel linear mixed-effects meta-analyses, and a meta-regression. Searches were performed in PubMed, Scopus, and PsycINFO in October 2020 and July 2021. Results From 1387 retrieved articles, 17 and six studies were included in the systematic review and meta-analyses, respectively. Although there was little consensus associating molecular biomarker levels with symptomology and/or treatment response, brain metabolites accessed via molecular biomarker-focused neuroimaging techniques may provide promising information on whether an individual with MDD would respond positively to NPTs. Furthermore, non-invasive brain stimulation interventions significantly increased the expression of neurotrophic factors (NTFs) compared to sham/placebo, regardless of add-on pharmacological treatment. Conclusions NTFs are candidate biomarkers to fine-tune NIBS for MDD treatment.publishe

    Moringa oleifera: Resource management and multiuse life tree

    Get PDF
    Moringa oleifera Lamarck (Moringaceae family) is a plant native from the Western and sub-Himalayan parts of Northwest India, Pakistan and Afghanistan. This species is widely cultivated across Africa, South-East Asia, Arabia, South America and Caribbean Islands. M. oleifera culture is also being distributed in the Semi-Arid Northeast of Brazil. It is a multiuse life tree with great environmental economic importance in industrial and medical areas. This review reports different purposes of M. oleifera including sustaining environmental resources, soil protection and shelter for animals. This plant requires not much care and distinct parts have bioactive compounds. Moringa tissues used in human and animal diets, also withdraw pollutants from water. The seeds with coagulant properties used in water treatment for human consumption, remove waste products like surfactants, heavy metals and pesticides. The oil extracted from seeds is used in cosmetic production and as biodiesel. M. oleifera tissues also contain proteins with different biological activities, including lectins, chitin-binding proteins, trypsin inhibitors, and proteases. The lectins are reported to act as insecticidal agents against Aedes aegypti (vector of dengue, chikungunya and yellow fevers) and Anagasta kuehniella (pest of stored products) and also showed water coagulant, antibacterial and blood anticoagulant activities. The presence of trypsin inhibitors has been reported in M. oleifera leaves and flowers. The inhibitor from flowers is toxic to larvae of A. aegypti. The flowers also contain caseinolytic proteases that are able to promote clotting of milk. In this sense, M. oleifera is a promising tree from a biotechnological point of view, since it has shown a great variety of uses and it is a source of several compounds with a broad range of biological activities.Conselho Nacional de Desenvolvimento Científico e Tecnológico for fellowship (LCBBC) and to the Foundation for Science and Technology, POPH/FSE (AFSS

    Coagulant properties of Moringa oleifera protein preparations : application to humic acids removal

    Get PDF
    This work aimed to characterize the coagulant properties of protein preparations from Moringa oleifera seeds to remove humic acids from water. Three distinct preparations were assayed, namely extract (seeds homogenized with 0.15 M NaCl), fraction (extract precipitated with 60 % w/v ammonium sulphate) and cMoL (protein purified with guar gel column chromatography). The extract showed the highest coagulant activity in a protein concentration between 1 mg/L and 180 mg/L at pH 7.0. The zeta potential of the extract (-10 mV to -15 mV) was less negative than that of the humic acid (-41 mV to -42 mV) in a pH range between 5.0 and 8.0; thus, the mechanism that might be involved in this coagulation activity is adsorption and neutralisation of charges. Reduction of total organic carbon (TOC) and dissolved organic carbon (DOC) was observed in water samples containing 9 mg/L carbon as humic acid when treated with 1 mg/L of the extract. It was also observed a decrease in colour and in the aromatic content of the treated water. These results suggested that the extract from M. oleifera seeds in a low concentration (1 mg/L) can be an interesting natural alternative to remove humic acid from water in developing countries. The dose of extract determined in the present study do not impart odour and colour to the treated water.The authors acknowledge the financial support from the Portuguese Fundacao para Ciencia e a Tecnologia (FCT), through the post-doctoral grant SFRH/BPD/37349/2007, and the Brazilian programmes: Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), VALNATURA ALFA and the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

    Isolation of a seed coagulant Moringa oleifera lectin

    Get PDF
    In this work hemagglutinating activity (HA) was investigated in distinct Moringa oleifera tissue extracts. A new lectin from seeds (cMoL) was purified and characterized; hemagglutinating and coagulating activities were evaluated. HA was detected in 0.15 M NaCl extracts from flowers and rachis inflorescence (5%, w/v), seeds, leaves, fundamental tissue of stem and steam bark (10%, w/v). cMoL isolated after saline extraction and guar gel column chromatography was active at pH range 4.0–9.0 agglutinating erythrocytes from rabbit and human blood types. Extracts of tissues and cMoL activities were carbohydrate inhibited; azocasein and asialofetuin abolished cMoL HA. The lectin was thermostable at 100 °C during 7 h. Polyacrylamide gel electrophoresis under reduced conditions revealed a main polypeptide band of 26.5 kDa; native basic cMoL was detected as a unique band. Seed lectin preparations and cMoL showed coagulant activity, similar to aluminium sulphate, the coagulant most widely used in water treatment.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Científico e Tecnológico (CNPq
    • …
    corecore