846 research outputs found
Physicochemical characterization, microbiological quality and safety, and pharmacological potential of Hancornia speciosa Gomes
Hancornia speciosa Gomes is a fruit tree, commonly known as the mangaba tree, which is widespread throughout Brazil. The leaves
of this plant are used in traditional medicine for medicinal purposes. Thus, the objective of this study was to perform a
physicochemical characterization, identify the lipophilic antioxidants and fatty acids, and determine the microbiological quality
and safety of H. speciosa leaves. In addition, the antioxidant, antimutagenic, and inhibitory activities of the ethanolic extract of
H. speciosa leaves (EEHS) against enzymes related to neurodegenerative diseases, inflammation, obesity, and diabetes were
investigated. Furthermore, this study aimed at assessing the in vivo effects of the EEHS on the glycemia of normoglycemic and
diabetic Wistar rats. Physicochemical characterization was performed by colorimetry and gas-liquid chromatography with flame
ionization detection (GC-FID). The total number of colonies of aerobic mesophiles, molds, and yeasts was determined. The total
coliforms and Escherichia coli were counted using the SimPlates kit, and sulphite-reducing Clostridium spores were quantified
using the sulphite-polymyxin-sulfadiazine agar method. Salmonella spp. were detected using the 1-2 Test. The antioxidant activity
of the EEHS was measured by its inhibition of 2,2′-azobis(2-amidinopropane) dihydrochloride- (AAPH-) induced oxidative
hemolysis of human erythrocytes. The antimutagenic activity was determined using the Ames test. The acetylcholinesterase,
butyrylcholinesterase, tyrosinase, hyaluronidase, lipase, α-amylase, and α-glycosidase enzyme-inhibiting activities were assessed
and compared with commercial controls. The in vivo effects of the EEHS were assessed using the oral glucose tolerance test in
normoglycemic Wistar rats and measuring the blood glucose levels in diabetic rats. The results demonstrated physical-chemical
parameters of microbiological quality and safety in the leaves of H. speciosa, as well as antioxidant and antimutagenic activities
and inhibition of enzymes related to neurodegenerative diseases, inflammation, obesity, and diabetes. In in vivo assays, it was
shown that the normoglycemic rats challenged with glucose overload show significantly decreased blood glucose levels when
treated with the EEHS. Taken together, the results ensure the microbiological quality and safety as well as showing the contents of
carotenoids and polyunsaturated fatty acids of H. speciosa leaves. Additionally, the antioxidant, antimutagenic, anti-inflammatory,
anti-Alzheimer’s disease, anti-Parkinson’s disease, antiobesity, and antihyperglycemic activities of the EEHS were demonstrated.This work was supported by grants from Fundação de Apoio
ao Desenvolvimento do Ensino, Ciência e Tecnologia do
Estado de Mato Grosso do Sul (FUNDECT), Coordenação
de Aperfeiçoamento de Pessoal de Nível Superior (CAPES),
Conselho Nacional de Desenvolvimento Científico e Tecnológico
(CNPq), Universidade Federal da Grande Dourados
(UFGD), and PRODER (24.073–A, Portugal).info:eu-repo/semantics/publishedVersio
Diversity, chemical constituents and biological activities of endophytic fungi isolated from Schinus terebinthifolius raddi
Schinus terebinthifolius Raddi is a medicinal plant widely used for the treatment of
various diseases. The secondary metabolites responsible for the pharmacological properties can
be produced directly by the plant or by endophytic fungi. The objective of this study was to
evaluate the diversity of endophytic fungi of di erent parts of S. terebinthifolius and to identify
chemical compounds produced by endophytes and their antioxidant and antibacterial activities.
For this, fruits, stem bark and roots were dried, ground and placed in fungal growth medium.
The selected endophytes were grown and subjected to extraction with ethyl acetate. DPPH, FRAP,
-carotene bleaching and antimicrobial assays were performed. The phylogenetic tree was elaborated,
encompassing 15 di erent species. The fungal extracts showed hydroxybenzoic acids and 1-dodecanol
as predominant compounds. All fungal extracts exhibited antioxidant activity. The fungal extracts
exhibited bactericidal and bacteriostatic activities against Gram-positive and Gram-negative bacterial
ATCC strains and against methicillin-resistant nosocomial bacteria. Among the 10 endophytic
fungi evaluated, the extract of the fungus Ochrocladosporium elatum showed higher phenolic content
and exhibited higher antioxidant and antibacterial activities in all tests. Together, the results increase
the known diversity of S. terebinthifolius endophytic fungi, secondary metabolites produced and their
antioxidant and antibacterial activities.Thisworkwas supported by grants fromFoundation to Support to Fundação deApoio aoDesenvolvimento do Ensino, Ciência e Tecnologia do Estado deMato Grosso do Sul (FUNDECT), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).info:eu-repo/semantics/publishedVersio
Quality and microbiological safety and antifungal activity of Hancornia Speciosa Gomes (Apocynaceae).
The aim of this study was to evaluate the quality
and microbiological safety and antifungal activity of the
ethanolic extract of the leaves of Hancomia Gomes (EEHS), a Brazilian fruit tree popularly known mangabeira
.info:eu-repo/semantics/publishedVersio
Conservation of wild mushrooms through electron beam irradiation
The high perishability is a characteristic of the mushrooms consumed in fresh. Therefore, it is mandatory the application of effective conservation technologies to preserve and protect their chemical composition and nutritional value. Drying processes are widely used, but do not avoid the development of bacteria and fungi which have the ability to survive for long periods of time in dry foods, causing the loss of some nutrients and leading to food browning and oxidation of lipids and vitamins [1]. Irradiation appears as an alternative to food preservation assuring and maintaining its quality [2]. In this work, the effects of electron beam irradiation and storage time on nutritional and chemical parameters of wild samples of Macrolepiota procera (Scop.) Singer, previously submitted to a drying process (oven at 30 ºC), were assessed. The wild mushroom samples were collected in Trás-os-Montes; electron beam irradiation (doses 0.5, 1 and 6 kGy) was carried out in the INCT- Institute of Nuclear Chemistry and Technology in Warsaw, Poland and the analyses were performed over the storage period (0, 6 and 12 months). The results were compared with a control (non-irradiated samples). The nutritional value was determined according to the official procedures of food analysis, while the profiles of fatty acids, tocopherols, mono and oligosaccharides were obtained by chromatographic techniques [1]. The irradiation showed a better capacity to maintain the nutritional and chemical profile, in comparison with the storage time. Effectively, the storage time had a significant effect in all parameters, but fatty acids undergone significant changes both with irradiation doses and storage time. Electron beam irradiation can be considered a suitable technique for conservation of mushrooms for long periods of time, attenuating the changes caused by the drying treatment.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013), A. Fernandes (SFRH/BPD/114753/2016) and J.C.M. Barreira contract.info:eu-repo/semantics/publishedVersio
Chemical profile and antioxidant, anti-inflammatory, antimutagenic and antimicrobial activities of geopropolis from the stingless bee Melipona orbignyi
Licensee MDPI, Basel, Switzerland. Geopropolis is a resin mixed with mud, produced only by stingless bees. Despite being popularly known for its medicinal properties, few scientific studies have proven its biological activities. In this context, the objective of this study was to determine the chemical composition and antioxidant, anti-inflammatory, antimutagenic and antimicrobial activities of the Melipona orbignyi geopropolis. The hydroalcoholic extract of geopropolis (HEGP) was prepared and its chemical composition determined by high performance liquid chromatography coupled to diode array detector and mass spectrometry (HPLC-DAD-MS). The antioxidant activity was determined by the capture of free radicals and inhibition of lipid peroxidation in human erythrocytes. The anti-inflammatory activity was evaluated by the inhibition of the hyaluronidase enzyme and the antimutagenic action was investigated in Saccharomyces cerevisiae colonies. The antimicrobial activities were determined against bacteria and yeasts, isolated from reference strains and hospital origin. The chemical composition of HEGP included flavonoids, derivatives of glycosylated phenolic acids and terpenoids. HEGP showed high antioxidant activity, it inhibited the activity of the inflammatory enzyme hyaluronidase and reduced the mutagenic effects in S. cerevisiae. In relation to the antimicrobial activity, it promoted the death of all microorganisms evaluated. In conclusion, this study reveals for the first time the chemical composition of the HEGP of M. orbignyi and demonstrates its pharmacological properties.This work was supported by grants from Foundation to Support to Fundação de Apoio
ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT, Brazil),
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil), Conselho Nacional de
Desenvolvimento Científico e Tecnológico (CNPq, Brazil) and PRODER, (24.073 – Â, Portugal).info:eu-repo/semantics/publishedVersio
Microbiological quality, chemical profile as well as antioxidant and antidiabetic activities of Schinus terebinthifolius Raddi
Schinus terebinthifolius Raddi, commonly known as Brazilian peppertree, is a plant species widely used in Brazilian traditional medicine for various purposes. The objective of this study was to assess the microbiological quality, safety, chemical profile as well as antioxidant and antidiabetic potentials of different parts of S. terebinthifolius. Microbiological analysis of the methanolic extracts of the roots (MESR), stem bark (MESB) and leaves (MESL) of S. terebinthifolius showed no microbial growth. The concentrations of phenolic compounds, phenolic acids and flavonoids were determined by spectrophotometry. The phenolic compounds of the MESL were identified by liquid chromatography coupled to a diode array detector and mass spectrometer (LC-DAD-MS). The antioxidant activities of the extracts were analyzed by 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radical (DPPH[rad]), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical (ABTS[rad] + ), fluorescence recovery after photobleaching (FRAP), reducing power, β-carotene bleaching and malondialdehyde (MDA) assays in human erythrocytes. The antidiabetic properties of the extracts were demonstrated in vitro by their inhibition of the α-glucosidase enzyme and their anti-glycation activity via fructose and glyoxal. After showing no acute toxicity in vivo, MESL was able to lower postprandial glycemia after glucose overload in normoglycemic mice as well as the water and feed intake, liver weight, glycemia and serum levels of glycated hemoglobin, aspartate transaminase (AST) and alanine transaminase (ALT) in diabetic mice. Overall, S. terebinthifolius extracts showed microbiological safety along with antioxidant and antidiabetic activities, likely mediated by its chemical constituents, such as gallic acid, gallotannins and glycosylated flavonolsThis work was supported by grants from Foundation to Support to Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).info:eu-repo/semantics/publishedVersio
Influencia do fenómeno enos na resposta hidrológica anual da sub-bacia Amazonica/Brasil (Regiao Hidrográfica do Xingu/Pará)
Ponencia presentada en: XXX Jornadas Científicas de la AME y el IX Encuentro Hispano Luso de Meteorología celebrado en Zaragoza, del 5 al 7 de mayo de 2008
Spiral wave dynamics in a neuronal network model
Spiral waves are spatial-temporal patterns that can emerge in different
systems as heart tissues, chemical oscillators, ecological networks and the
brain. These waves have been identified in the neocortex of turtles, rats, and
humans, particularly during sleep-like states. Although their functions in
cognitive activities remain until now poorly understood, these patterns are
related to cortical activity modulation and contribute to cortical processing.
In this work, we construct a neuronal network layer based on the spatial
distribution of pyramidal neurons. Our main goal is to investigate how local
connectivity and coupling strength are associated with the emergence of spiral
waves. Therefore, we propose a trustworthy method capable of detecting
different wave patterns, based on local and global phase order parameters. As a
result, we find that the range of connection radius (R) plays a crucial role in
the appearance of spiral waves. For R < 20 {\mu}m, only asynchronous activity
is observed due to small number of connections. The coupling strength (gsyn )
greatly influences the pattern transitions for higher R, where spikes and
bursts firing patterns can be observed in spiral and non-spiral waves. Finally,
we show that for some values of R and gsyn bistable states of wave patterns are
obtained
The Chemical Profile of Senna velutina Leaves and Their Antioxidant and Cytotoxic Effects
Natural products can be a source of biomolecules with antioxidant activity which are able to prevent oxidative stress-induced diseases and show antitumor activity, making them important sources of new anticancer drug prototypes. In this context, this study aimed to analyze the chemical composition of an ethanol extract of Senna velutina leaves and to assess its antioxidant and cytotoxic activities in leukemic cells. The antioxidant properties were evaluated using a DPPH free radical scavenging assay and by examining the extract's inhibition of AAPH-induced lipid peroxidation in human erythrocytes. Its cytotoxicity and possible mechanisms of action were assessed in Jurkat and K562 leukemic cell lines. The ethanol extract contained flavonoids, such as epigallocatechin, epicatechin, kaempferol heteroside, rutin, and dimeric and trimeric proanthocyanidin derivatives. The extract exhibited antioxidant activity by scavenging free radicals and antihemolytic action, and it decreased malondialdehyde content in human erythrocytes. Furthermore, the extract also induced leukemic cell death by activating intracellular calcium and caspase-3, decreasing mitochondrial membrane potential, and arresting the cell cycle in S and G2 phases. Hence, S. velutina leaf extract contains antioxidant and antileukemic biomolecules with potential applications in diseases associated with oxidative stress and in the inhibition of tumor cell proliferation.This work was supported by grants of the Fundac¸˜ao de
Apoio ao Desenvolvimento do Ensino, Ciˆencia e Tecnologia
do Mato Grosso do Sul (FUNDECT), Conselho Nacional
de Desenvolvimento Cient´ıfico e Tecnol´ogico (CNPq), and
Coordenac¸˜ao de Aperfeic¸oamento de Pessoal de N´ıvel Superior
(CAPES). Edson Lucas dos Santos, Carlos Alexandre
Carollo, and Edgar J. Paredes-Gamero are recipients of fellowships
from Brazilian National Research Council (CNPq),
Brazil.info:eu-repo/semantics/publishedVersio
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