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3R and 2H polytypes of MoS2: DFT and DFPT calculations of structural, optoelectronic, vibrational and thermodynamic properties
(Elsevier, 2017-12) Coutinho, S.S.; Barboza, Carlos Antonio; Tavares, M.S.; Frazão, N.F.; Moreira, E.; Azevedo, David L.
We report the results of a theoretical study on the behavior of the structural, optoelectronic, vibrational, including infrared and Raman theoretical spectra, phonon spectrum, and thermodynamic properties of 3R- and 2H- polytypes of molybdenum disulfide (MoS2) using density functional theory (DFT) considering both the local density and generalized gradient approximation, LDA and GGA, respectively. Calculated lattice parameters are close to the experimental measurements, and an indirect band gap E(A→KΓ)¼ 1:33 eV (0.68 eV) was obtained within the GGA (LDA) level of calculation, considering the 3R-polytype, and for the 2H- polytype an indirect band gap E(Γ→KΓ)¼ 1:30 eV (0.70 eV) was obtained within the GGA (LDA) approximation. The complex dielectric function and absorption of 3R-MoS2 and 2H-MoS2 polytypes were shown to be sensitive to the plane of polarization of the incident light. The phonon dispersion relation together with density of states (DOS) as well as theoretical peaks of the infrared (IR) and Raman spectra in the frequency range of 0–800 cm 1 was analyzed and assigned, considering the norm-conserved pseudopotentials. The thermodynamic potentials, the specific heat at constant volume and Debye temperature of the 3R-MoS2 and 2H-MoS2 polytypes are also calculated, whose dependence on the temperature are discussed.
A relação entre a alimentação coletiva e gestão de resíduos: o papel da educação ambiental na redução de desperdício
(Revista Brasileira de Educação Ambiental, 2022) Rolim, Priscilla Moura; Seabra, Larissa Mont'Alverne Jucá; Pires, Vanessa Cristina da Costa; https://orcid.org/0000-0002-3847-5744
A produção de refeições coletivas em ambientes alimentares como as unidades de alimentação e nutrição promove elevada geração de resíduos sólidos, ocasionando impactos econômicos, ambientaise à saúdepública. A gestão desses estabelecimentosdeve estar comprometida como desenvolvimento sustentável e o cumprimento da Política Nacional de Resíduos Sólidos. Este estudo trata-se de uma revisão narrativa deliteratura sobre os procedimentos de gestão de resíduos sólidos no âmbito das práticas de alimentação coletiva. Foram pesquisados artigos e documentos oficiais publicados no período de 2000 a 2021 nas seguintes bases de dados Google acadêmico, Science Direct e Scopus, utilizando descritores em português e inglês: Desperdício de alimentos (Food waste), Unidade de alimentação e nutrição (food service), Gestão de resíduos (Waste management). A investigação trouxe uma discussão teórica que perpassou sobre adestinação correta e sustentável dos resíduos, por meio de compostagem, coleta seletiva e reciclagem, implantação de hortas e ações de Educação Ambiental. Os estudos afirmam que a adoção dessas ações contribui para uma produção de refeições mais sustentáveis
Abortion: a review of women's perception in relation to their partner's reactions in two brazilians cities
(Associação Médica Brasileira, 2014-07) Nonnenmacher, Daniele; Benute, Gláucia Rosana Guerra; Nomura, Roseli Mieko Yamamoto; Azevedo, George Dantas de; Dutra, Elza Maria do Socorro; Rebouças, Melina Séfora Souza; Luci, Mara Cristina Souza de; Francisco, Rossana Pulcineli Vieira
Objective: to analyze women’s perception in relation to their partner’s reaction and behavior during the abortion process in two Brazilian capitals, associating the variables from women who suffered a spontaneous abortion with those from women who induced it. Methods: semi-structured, questionnaire-based interviews were conducted with 285 women who underwent spontaneous abortion and 31 who reported having induced it. The data were analyzed using the thematic analysis technique, and, subsequently, by the IBM SPSS Statistics Standard Edition software program. The significance level was set at p < 0.05. Results: in both capitals, the women who induced an abortion referred to the partner as the person who could not find out about the abortion (p<0.01 in Natal; p = 0.02 in São Paulo-SP) and, simultaneously, as the one who could have avoided it (p < 0.01 in Natal; p = 0.03 in São Paulo). In Natal-RN, induced abortion was associated with the partner’s absence at the time pregnancy was confirmed (p = 0.02) and, in Sao Paulo-SP, with their negative reaction to news of the pregnancy (p = 0.04) and lack of participation in the abortion process (p < 0.01). Conclusion: despite having achieved independence, women still regard male participation in the abortion process as an important factor. The specifics of each capital denote the influence of the geographic and cultural dimension, indicating the need to take into account the particulars of each region in Brazil while considering a holistic approach to women’s health
Acute and chronic alcohol administration: effects on performance of zebrafish in a latent learning task
(Elsevier, 2015) Luchiari, Ana Carolina; Salajan, Diana C.; Gerlai, Robert
Alcohol abuse is a major medical problem. Zebrafish have been proposed to model alcohol related human disorders. Alcohol impairs learning and memory. Here, we analyze the effects of alcohol on performance of zebrafish in a recently developed latent learning paradigm. We employ a 2 × 3 × 2 experimental design (chronic × acute alcohol treatment × path blocked). The latent learning task had two phases: one, 30 min long exploration trials (16 days, 1 trial/day) with left or right path of a complex maze blocked, and two, a subsequent probe trial with all paths open leading to a goal box that now contained stimulus fish. During the 16 days each fish received one of two chronic treatments: freshwater or 0.50% (v/v%) alcohol. Subsequently, fish were immersed for 1 h in one of the following solutions: 0.00 (freshwater), 0.50% or 1.00% alcohol, the acute challenge. Behavior of fish was recorded during the probe trial that commenced immediately after the acute treatment. Path choices, latency to leave the start box and to enter the goal box, time spent in the goal box, distance traveled, and duration of freezing were quantified. We found that acute exposure to 1.00% alcohol after chronic freshwater disrupted learning performance, so did exposure to freshwater after chronic alcohol treatment (withdrawal). We also found exposure to chronic alcohol to diminish the effect of subsequent acute alcohol suggesting development of tolerance. Our results demonstrate that analysis of learning performance of zebrafish allows detection of alcoholinduced functional changes. The simplicity and scalability of the employed task also imply the utility of the zebrafish in high throughput drug screens
Adjustments in the time, distance and direction of foraging in dinoponera quadriceps workers
(Springer, 2014) Azevedo, Dina L. O.; Medeiros, Jeniffer C.; Araújo, Arrilton
We measured individual decisions regarding the adjustments of time, distance and direction of foraging in Dinoponera quadriceps.We observed two colonies in an area of secondary Atlantic Forest, FLONA-ICMBio, in Northeastern Brazil. The workers were individually marked. We recorded the displacement of workers, their returns to the nest with and without food, the time spent searching for food, maximum and total distance, inter-trip latency and direction of trips. The time spent searching for food, maximum distance and transport velocity did not vary with food size. The previous trip success reduced the latency between foraging trips and increased the percentage of success on the next trip. However, this previous success did not demonstrate a significant variation relative to the time spent searching on the next trip or direction of search. The workers maintained an individual directional fidelity during foraging. The adjustments of these foraging variables under individual control contributed to the efficiency at the colony level. D. quadriceps is compatible with the central place theory and risk sensitivity model of behavior
Affect-regulated exercise: an alternative approach for lifestyle modification in overweight/obese women with polycystic ovary syndrome
(Taylor and Francis, 2015-09-25) Costa, Eduardo Caldas; Sá, Joceline Cássia Ferezini de; Costa, Ingrid Bezerra Barbosa; Meireles, Rodrigo da Silva Rosa Veleda; Lemos, Telma Maria Araújo Moura; Elsangedy, Hassan Mohamed; Krinski, Kleverton; Azevedo, George Dantas de
Objective: affect-regulated exercise (‘‘ARE’’) is an alternative approach to guide exercise intensity based on feeling of pleasure. The aim of this study was to analyze if overweight/obese women with polycystic ovary syndrome (PCOS) meet the American College of Sports Medicine (ACSM) recommendation regarding to exercise intensity to improve health status during a single bout of ‘‘ARE". Methods: a sample of 14 overweight/obese women with PCOS (18–34 years) performed a single bout of ‘‘ARE’’ (40 min of aerobic exercise on outdoor track). The Feeling Scale (FS) was used to guide ‘‘ARE’’ intensity/pace maintaining an affective valence between ‘‘good’’ and ‘‘very good’’ during all time. Heart rate (HR), speed, % of HR at first and second ventilatory threshold (VT1 and VT2) and time spent at moderate (64–76% of HRmax) and vigorous (77–95% of HRmax) intensity during ‘‘ARE’’ were measured with a global positioning system (GPS) device. Results: volunteers exercised at 73% (68–78%) of HRmax, 5.8 (5.2–6.2) km/h, 93.4% of HR at VT1 (89.3–98.2) and 80.5% of HR at VT2 (75.3–84.6) and spent 480% of time at moderate intensity. Conclusions: overweight/obese women with PCOS met the ACSM recommendation regarding exercise intensity to improve health status when exercised between ‘‘good’’ and ‘‘very good’’ of FS. Thus, ‘‘ARE’’ may be an interesting approach to be used in clinical practice regarding to exercise prescription and/or physical activity advice
Aging-related changes on social synchronization of circadian activity rhythm in a diurnal primate (Callithrix jacchus)
(Taylor and Francis, 2020-06-23) Gonçalves, Fabiana Barbosa; Gonçalves, Bruno S. B.; Cavalcante, Jeferson de Souza; Azevedo, Carolina Virginia Macedo de
The input of environmental time cues and expression of circadian activity rhythms may change with aging. Among nonphotic zeitgebers, social cues from conspecific vocalizations may contribute to the stability and survival of individuals of social species, such as nonhuman primates. We evaluated aging- related changes on social synchronization of the circadian activity rhythm (CAR) in a social diurnal primate, the common marmoset. The activity of 18 male marmosets was recorded by actiwatches in two conditions. (1) Experimental – 4 young adult (5 ± 2 yrs of age) and 4 older (10 ± 2 yrs of age) animals maintained under LD 12/12 h and LL in a room with full insulation for light but only partial insulation for sound from vocalizations of conspecifics maintained outdoors in the colony; and (2) Control – 10 young adult animals maintained outdoors in the colony (5 animals as a control per age group). In LL, the CAR of young adults showed more stable synchronization with controls. Among the aged marmosets, two free-ran with τ > 24 h, whereas the other two showed relative coordination during the first 30 days in LL, but free-ran thereafter. These differences were reflected in the “social” phase angles (ψon and ψoff) between rhythms of experimental and control animal groups. Moreover, the activity patterns of aged animals showed lower social synchrony with controls compared to young adults, with the time lags of the time series between each experimental group and control group being negative in aged and positive in young adult animals (t-test, p < 0.05). The index of stability of the CAR showed no differences according to age, while the intradaily variability of the CAR was higher in the aged animals during LD-resynchronization, who took additional days to resynchronize. Thus, the social modulation on CAR may vary with age in marmosets. In the aged group, there was a lower effect of social synchronization, which may be associated with aging-related changes in the synchro- nization and generation of the CAR as well as in system outputs
Alterações bioquímicas em ratos com doença periodontal e tratados com olmesartana, captopril e atorvastatna
(Universidade Federal da Bahia - UFBA, 2013) Araújo, Aurigena Antunes; Souza, Graziene Lopes de; Silva, Gisele Ribeiro da; Silva, Larissa Marina Pereira; Lima, Flávio Maurílio dos Santos; Mata, Neida da
Introdução: A doença periodontal é o processo inﬂamatório que ocorre na gengiva em resposta a antgenos bacterianos da placa dentária. Como a doença periodontal acomete indivíduos adultos, principalmente, idosos, a presença desta patologia em pacientes com fatores de risco para doenças cardiovasculares, que estão fazendo utlização de medicamentos se torna um achado usual. Objetvo: verifcar as alterações bioquímicas decorrentes da utlização subcrônica de Olmesartana, Captopril e Atovastatna em animais com doença periodontal. Metodologia: Foram utlizados 50 ratos Wistar com pesos entre 250-400g, a doença periodontal foi induzida com ligadura de fo nylon 3-0, por 10 dias, os animais receberam dose oral única e diária de Olmesartana (1 e 10mg/Kg), Captopril (1,5 e 10mg/Kg) e Atovastatna (1,5 e 10mg/Kg). No 11º dia cada subgrupo foi eutanasiado com Tiopental sódico na dosagem de 20 mg/Kg e o sangue colhido para avaliação bioquímica. As variáveis estudadas foram glicose, creatnina, uréia, colesterol total, triglicerídeos, HDL, LDL, TGO e TGP A leitura foi realizada no equipamento semiiautomátco BioPlus 2000®. Para verifcar as diferenças entre os grupos estudados foi utlizado o Teste t de Student com nível de signifcância de 5% no programa Graf Pad Install. Resultados: A doença periodontal elevou signifcantemente os níveis de glicose, LDL-C e colesterol total (p<0,05). Além disso nos animais tratados com atovastatn, um efeito farmacológico esperado, que era redução nos níveis de LDL-C, e aumento do HDL-C, não foram encontrados. Conclusão: O estudo aponta para um importante efeito da doença periodontal, na resposta a medicamentos sistêmicos.
Alterações histológicas e morfométricas da tuba uterina de cabras sem raça definida durante o ciclo estral
(UFERSA, 2015) Brito, Keylle de Souza; Braz, Janine Karla França da Silva; Miranda-Moura, Maria Tereza; Maia, Marciane da Silva; Silva, Naisandra Bezerra da; Papa, Paula de Carvalho; Oliveira, Moacir Franco de; Moura, Carlos Eduardo Bezerra de
Objetivou-se caracterizar as variações morfométricas da tuba uterina de cabras durante o ciclo estral. Para isso foram utilizados 20 cabras sem raça definida (SRD) adultas, divididas em 4 grupos: Grupo 1(D3)M - 3 dias após ovulação; Grupo 2 (D12)D - dia 12º pós-ovulação (p.o); Grupo 3 (D18)P - dia 18º p.o e Grupo 4 (D22)E - dia 22º p.o., correspondendo as fases de metaestro, diestro, proestro e estro, respectivamente. Após o tratamento hormonal, os animais foram abatidos e tiveram as tubas uterinas coletadas para mensuração do comprimento das regiões da tuba e fixados em formaldeído 10% por 24h, para análises histomorfométricas. Após esse período os fragmentos foram submetidos ao processamento histológico padrão. Dessa forma, foi possível mensurar a altura do epitélio e quantificar as células cilíndricas (CC) e células secretórias (CS). Nesse estudo, o comprimento das regiões da tuba variou conforme fase do ciclo, com menores valores aos 22 dias p.o. (grupo 4). Enquanto, a altura do epitélio aumentou nas regiões da tuba à medida que se distanciava do estro (grupo 4). Nas fimbrias e infundíbulo, a proporção de CC foi maior que CS, independente da fase do ciclo, com maior percentual no grupo 4. No istmo predominou as CS ao longo do ciclo, sendo significativamente maior também no grupo 4. Na ampola não houve diferença significativa entre a proporção de CC e CS, exceto nos grupos 3 e 4, nos quais predominaram CC. Assim, a tuba uterina de cabras apresenta modificações morfológicas e morfométricas ao longo do ciclo estral.
Análise da relação entre custo e consumo dos antipsicóticos típicos e atípicos: implicações para a saúde pública
(Universidade Federal da Bahia - UFBA, 2007) Araujo, Aurigena Antunes de; Alves, Maria do Socorro Costa Feitosa; Guerra, Gerlane Coelho; Xavier, Caroline Addison; Rodrigues, Francisco das Chagas; Diógenes, Arícia Rodrigues
O objetivo deste estudo foi verificar a relação entre custo e consumo dos antipsicóticos típicos e atípicos. A coleta de dados foi realizada no Hospital Psiquiátrico Dr. João Machado, Natal, Rio Grande do Norte (RN), Brasil, no período de 2002 a 2005. Para a comparação do custo ou consumo entre os dois grupos de antipsicóticos, utilizou-se o Teste t de Student com nível de significância de 5 %. A correlação entre custo e consumo para cada grupo de antipsicótico foi verificada pelo Coeficiente de Correlação de Pearson, com nível de significância de 5 %. Os resultados mostraram uma diferença estatisticamente significante entre o custo dos medicamentos típicos e atípicos (p < 0,0001), bem como uma correlação positiva entre custo e consumo para medicamentos atípicos (r = 0,96, p < 0,02). O estudo demonstrou que existe preocupação e compromisso do Estado do Rio Grande do Norte, Brasil, em incrementar a terapia com os antipsicóticos atípicos. A diferença entre os custos dos antipsicóticos típicos e atípicos podem representar um empecilho para incrementar o acesso dos pacientes com esquizofrenia a uma terapêutica que possibilite melhor qualidade de vida.
Análise do processo de aprendizagem e alfabetização científica sobre a evolução dos veterbrados em um museu de ciências
(II Seminário Nacional do Ensino Médio - SENACEM, 2012) Pereira, Josélia Domingos; Santos, Adriana de Souza; Costa, Ivaneide Alves Soares da
Análisis histológica preliminar de el esófago de callithrix jacchus en cautiverio
(Revista Argentina de Anatomia Online, 2014) Duque Neto, Sebastião Pacheco; Amarante, Maria do Socorro; https://orcid.org/0000-0002-5569-7568
Anatómicamente el esófago posee parte cervical, una torácica, y una abdominal, y esta última llega en el estómago. Su organizacíon histológica se constituye del epitélio escamoso estratificado no queratinizado, poseyendo además de esta capa de la mucosa, submucosa, capas de músculo y serosa, con la presencia de glándulas mucosas y el tejido linfoide. El reconocimiento de la anatomía y la histología del esófago, incluyendo su relación con el estómago, es de gran importancia tanto para los estudios de la gastroenterología. El aumento de la incidencia de tumores en la parte abdominal del esófago, así como las consecuencias de la enfermedad de reflujo gastroesofágico son razones para el desarrollo de modelos animales con primates no humanos. Este estudio tiene como objetivo presentar un hallazgo histológico de los esófago de primates no humanos, el Callithrix jacchus (sagui o tití). Este es un pequeño mono neotropical (30cm, 230g a 420g) que se encuentra en el entorno natural en el noreste de Brasil, que se promociona como un buen modelo para la investigación biomédica. Nacidas y mantenidas en cautiverio en el Centro de Primatología semi-natural de la Universidad Federal de Rio Grande do Norte (Natal, Brasil) hembras adultas fueron sacrificados para la extracción del cerebro, y fue trasladado inmediatamente al Laboratorio de Histología, donde se realizó la extracción del esófago para preparacíon histológica. Las secciones transversales en las partes cervical, torácico y abdominal muestran la presencia de epitelio escamoso estratificado no queratinizado. En la porción abdominal (acerca de la juncíon gastroesofágica), se observó la presencia de características de renovacíon intenso de tejidos, pero sin aparente metaplasia. La distribución de las fibras musculares en las direcciones longitudinal y transversal mostró el esperado: en la parte cervical de músculo estriado, músculo estriado y el músculo liso en la parte torácica, y músculos lisos en la parte abdominal. Sin embargo, no se observó en cualquier corte la presencia de tejido linfoide o tejido glandular, como sería de esperar. Este hallazgo puede estar relacionado con la característica predominante de la dieta en cautiverio de los animales, que incluye gachas, que posiblemente llevó al desarrollo inadecuado de este aparato digestivo, a pesar de ser considerados que los monos regugitan los alimentos. Esta propuesta está de acuerdo con la ausencia de infiltrado linfocitario y metaplasia. Estos resultados también apuntan a la necesidad de evaluar cuidadosamente la indicación del perfil de alimentación a los monos en cautiverio
Anestésicos locais: revisando o mecanismo de ação molecular
(Conselho Federal de Farmácia, 2006) Araújo, Aurigena Antunes de; Silva, Inara Dantas da; Diniz, Rodrigo dos Santos; Guerra, Gerlane Coelho Bernardo
Os anestésicos locais são bases fracas que agem no axônio, bloqueando de modo reversível a geração e condução do impulso nervoso. Esses fármacos têm ação sob qualquer parte do sistema nervoso e em qualquer tipo de fibra. O seu uso têm se dado em larga escala na clínica médica e odontológica. Além de se prestarem ao uso nos procedimentos cirúrgicos, estão sendo associados ao tratamento da dor crônica, com os opióides, o que reduz a tolerância destes, no tratamento da artrite reumatóide e câncer (ROCHA et al, 2002). O primeiro anestésico local foi à cocaína, extraído de folhas de Erythroxylon coca, isolado em 1860, por Albert Niemann. Outros anestésicos locais, do tipo éster, surgiram depois, entre eles, a procaína (1905), tetracaína (1932) e cloroprocaína (1952). Os anestésicos locais do tipo amida foram introduzidos, em 1948, com a lidocaína, que serviu de padrão para síntese de outros anestésicos locais dentro deste grupo (CATTERAL& MACKIE, 2003).
Anti-IIa activity and antitumor properties of a hybrid heparin/heparan sulfate-like compound from Litopenaeus vannamei shrimp
(Elsevier, 2018-06-30) Brito, Adriana da Silva; Cavalcante, Rômulo S.; Cavalheiro, Renan P.; Palhares, Laís C. G. F.; Nobre, Leonardo Thiago Duarte Barreto; Souza, Giulianna Paiva Viana de Andrade; Nader, Helena B.; Lima, Marcelo A.; Chavante, Suely Ferreira
In this present study, the anti-IIa activity and the antitumor properties of a hybrid heparin/heparan sulfate-like compound (sH/HS) from Litopenaeus vannamei shrimp heads are related. In addition to inhibiting 90.7% of thrombin activity at the lowest tested concentration (0.5 μg/mL), sH/HS compound stimulated the synthesis of antithrombotic heparan sulfate by endothelial cells in a dose-dependent manner. In vitro experiments demonstrated that the molecule from shrimp displayed a potent anti-angiogenic effect, reducing over 80% of the tubular structures formation at 50 and 100 μg/mL. In addition, sH/HS compound was able to inhibit the migration of B16F10 cells at all tested concentrations without affecting the cell viability. Although the studied compound had no effect on the proliferation of such cells during a period of 24 h, it had a significant long-term antiproliferative effect, reducing about 80% of colony formation and anchorage-independent growth at 50 and 100 μg/mL concentrations. When its effectiveness was tested in vivo, it was demonstrated that sH/HS promoted a reduction of more than 90% of tumor growth. In the context of thromboembolic disorders associated with cancer, such findings make the sH/HS compound an excellent target for studies on inhibiting of development and tumor progression, and the prevention of coagulopathies
Anti-infl ammatory and antinociceptive activities of Phyllanthus niruri spray-dried standardized extract
(Springer, 2013) Araújo, Aurigena Antunes de; Porto, Cínthia R. C.; Soares, Luiz A. L.; Souza, Tatiane P.; Petrovick, Pedro R.; Lyra, Ibson L.; Araújo Júnior, Raimundo F.; Langassner, Silvana Maria Zucolotto; Guerra, Gerlane C. B.
Phyllanthus niruri L., Euphorbiaceae, spray-dried standardized extract was studied for its anti-inflammatory and antinociceptive activities in adult albino rats and mice. The anti-inflammatory effect of spray-dried standardized extract was observed in carrageenan-induced paw edema and thioglycolate-induced leukocyte migration, while antinociceptive effects were observed using Randall & Selitto, tail flick, and hot plate tests. This study showed that intraperitoneal spray-dried standardized extract at 100, 200, 800, or 1600 mg/kg reduced the vascular response in the inflammatory process of paw edema induced by 1% carrageenan. Oral spray-dried standardized extract at 100 or 200 mg/kg inhibited leukocyte migration to the site of inflammation induced by 3% thioglycolate. In rats, at 100 and 200 mg/kg intraperitoneally, the extract exhibited a marked peripheral analgesic effect in a Randall & Selitto assay and showed significant central analgesic activity in a hot plate and tail flick assay. In conclusion, this study suggested that Phyllanthus niruri spray-dried standardized extract has potent inflammatory and antinociceptive activities and that these activities are not modified by standard drying process, making it feasible to use the dry extract standardized to obtain a phytotherapic preparation and thus validating its use for the treatment of pain and inflammation disorders.
Anticoagulant, antioxidant and antitumor activities of heterofucans from the seaweed Dictyopteris delicatula
(MDPI, 2011-05-23) Magalhaes, Kaline Dantas; Costa, Leandro Silva; Fidelis, Gabriel Pereira; Oliveira, Ruth Medeiros; Nobre, Leonardo Thiago Duarte Barreto; Dantas-Santos, Nednaldo; Câmara, Rafael Barros Gomes da; Albuquerque, Ivan Rui Lopes; Cordeiro, Sara Lima; Sabry, Diego Araujo; Costa, Mariana Santana Santos Pereira; Alves, Luciana Guimaraes; Rocha, Hugo Alexandre de Oliveira
In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (~45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress
Anticonvulsant effects of fractions isolated from dinoponera quadriceps (Kempt) ant venom (Formicidae: ponerinae)
(Multidisciplinary Digital Publishing Institute, 2017) Nôga, Diana Aline Morais Ferreira; Brandão, Luiz Eduardo Mateus; Cagni, Fernanda Carvalho; Silva, Delano; Azevedo, Dina Lilia Oliveira de; Araújo, Arrilton; Santos, Wagner Ferreira dos; Miranda, Antonio; Silva, Regina Helena da; Ribeiro, Alessandra Mussi
Natural products, sources of new pharmacological substances, have large chemical diversity and architectural complexity. In this context, some toxins obtained from invertebrate venoms have anticonvulsant effects. Epilepsy is a neurological disorder that affects about 65 million people worldwide, and approximately 30% of cases are resistant to pharmacological treatment. Previous studies from our group show that the denatured venom of the ant Dinoponera quadriceps (Kempt) protects mice against bicuculline (BIC)-induced seizures and death. The aim of this study was to investigate the anticonvulsant activity of compounds isolated from D. quadriceps venom against seizures induced by BIC in mice. Crude venom was fractionated by high-performance liquid chromatography (HPLC) resulting in six fractions referred to as DqTx1–DqTx6. A liquid chromatography-mass spectrometry (LC/MS) analysis revealed a major 431 Da compound in fractions DqTx1 and DqTx2. Fractions DqTx3 and DqTx4 showed a compound of 2451 Da and DqTx5 revealed a 2436 Da compound. Furthermore, the DqTx6 fraction exhibited a major component with a molecular weight of 13,196 Da. Each fraction (1 mg/mL) was microinjected into the lateral ventricle of mice, and the animals were observed in an open field. We did not observe behavioral alterations when the fractions were given alone. Conversely, when the fractions were microinjected 20 min prior to the administration of BIC (21.6 nM), DqTx1, DqTx4, and DqTx6 fractions increased the latency for onset of tonic-clonic seizures. Moreover, all fractions, except DqTx5, increased latency to death. The more relevant result was obtained with the DqTx6 fraction, which protected 62.5% of the animals against tonic-clonic seizures. Furthermore, this fraction protected 100% of the animals from seizure episodes followed by death. Taken together, these findings indicate that compounds from ant venom might be a potential source of new anticonvulsants molecules
Antioxidant fucoidans obtained from tropical seaweed protect pre-osteoblastic cells from hydrogen peroxide-induced damage
(MDPI, 2019-08-28) Fidelis, Gabriel Pereira; Silva, Cynthia Haynara Ferreira; Nobre, Leonardo Thiago Duarte Barreto; Medeiros, Valquíria Pereira; Rocha, Hugo Alexandre de Oliveira; Costa, Leandro Silva
Some antioxidant compounds decrease the amount of intracellular reactive oxygen species (ROS) and consequently reduce the deleterious effects of ROS in osteoblasts. Thus, these compounds fight against osteoporosis. Brown seaweeds are a rich source of antioxidant fucose-containing sulfated polysaccharides (fucans and fucoidans). We obtained six fucoidans (FRFs)—F0.3, F0.5, F0.7, F1.0, F1.5, and F2.1—from Dictyota mertensii by proteolytic digestion followed by sequential acetone precipitation. Except for F0.3, all FRFs showed antioxidant activity in different in vitro tests. In pre- osteoblast-like cells (MC3T3-L1) exposed to H2O2-oxidative stress, caspase-3 and caspase-9 were activated, resulting in apoptosis of the cells. We also observed a decrease in superoxide dismutase (SOD) and alkaline phosphatase (ALP) activity. The antioxidant FRFs protected the cells from the oxidative damage caused by H2O2, decreasing intracellular ROS and caspase activation, and increasing SOD activity. The most effective protection against damage was provided by F0.7, F1.5, and F2.1. At 0.5 mg/mL, these FRFs also suppressed the H2O2-mediated inhibition of ALP activity. The data indicated that FRFs F0.7, F1.5, and F2.1 from D. mertensii were antioxidants that protected bone tissue from oxidative stress and could represent possible adjuvants for the treatment of bone fragility through counteracting oxidative phenomena
Antioxidant sulfated polysaccharide from edible red seaweed Gracilaria birdiae is an inhibitor of calcium oxalate crystal formation
(MDPI, 2020-04-28) Oliveira, Leticia Castelo Branco Peroba; Queiroz, Moacir Fernandes; Fidelis, Gabriel Pereira; Melo, Karoline Rachel Teodosio; Câmara, Rafael Barros Gomes da; Alves, Monique Gabriela das Chagas Faustino; Costa, Leandro Silva; Teixeira, Dárlio Inácio Alves; Melo-Silveira, Raniere Fagundes; Rocha, Hugo Alexandre de Oliveira
The genus Gracilaria synthesizes sulfated polysaccharides (SPs). Many of these SPs, including those synthesized by the edible seaweed Gracilaria birdiae, have not yet been adequately investigated for their use as potential pharmaceutical compounds. Previous studies have demonstrated the immunomodulatory effects of sulfated galactans from G. birdiae. In this study, a galactan (GB) was extracted from G. birdiae and evaluated by cell proliferation and antioxidant tests. GB showed no radical hydroxyl (OH) and superoxide (O2−) scavenging ability. However, GB was able to donate electrons in two further different assays and presented iron- and copper-chelating activity. Urolithiasis affects approximately 10% of the world’s population and is strongly associated with calcium oxalate (CaOx) crystals. No efficient compound is currently available for the treatment of this disease. GB appeared to interact with and stabilize calcium oxalate dihydrate crystals, leading to the modification of their morphology, size, and surface charge. These crystals then acquired the same characteristics as those found in healthy individuals. In addition, GB showed no cytotoxic effect against human kidney cells (HEK-293). Taken together, our current findings highlight the potential application of GB as an antiurolithic agent
Antitryptical, anticoagulant and hemagglutinating activities of Eucalyptus sp. seeds
(F1000Research, 2019-01-08) Santos, Yago Queiroz dos; Carelli, Gabriella Silva Campos; Veras, Bruno Oliveira de; Batista, Virgínia Cunha; França, Anderson Felipe Jácome de; Silva, Márcia Vanusa da; Santos, Elizeu Antunes dos
Background: Plant biodiversity has great value for science being an inexhaustible source for new bioactive molecules capable of offering environmentally friendly and innovative solutions for various areas of the industry. The scientific community has increased their interest in the study of plant species in the search of new molecules and to determine their mechanisms of action. Plant seeds are natural sources of bioactive compounds, such as carbohydrates, lipids and proteins with special focus on enzymatic inhibitors which protect them against digestive enzymes of phytopathogens and lectins that play an important role on carbohydrate signalization and metabolism during germination. The objective of the present study was to evaluate and describe the protein profile and to test the hemagglutinating, hemolytic and anticoagulant activities, as well as the antitryptic effect of extracts and fractions obtained from seeds of Eucalyptus species. Methods: The crude protein extract was obtained from the seed of Eucalyptus sp. with 0.02 M sodium phosphate buffer, at pH 6.6, and fractionated using ammonium sulfate in order to study its antitryptical properties as well as the capacity of hemagglutination and influence on hemostasis. Results: The crude extract showed a high effectiveness for trypsin inhibition. For hemagglutinating activity, the ammonium sulfate fraction 0-30% presented better activity, while no hemolytic activity was present in the obtained fractions. For anticoagulation assay, the fraction 0-30% showed better results. Conclusions: Taken together, the obtained results demonstrate the biotechnological potential of Eucalyptus sp. seeds, although further study is still necessary to better isolate as well as describe the bioactive compounds

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