• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 8
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

El sistema verbal en la lengua shawi

Julia Barraza de Garcia, Yris January 2005 (has links)
Made available in DSpace on 2014-06-12T18:35:24Z (GMT). No. of bitstreams: 2 arquivo8448_1.pdf: 1663373 bytes, checksum: 007a6825c7a5971e81ed142df19f4724 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / Este artigo apresenta um avanço na análise do sistema verbal do shawi língua, uma língua indígena falada na Amazônia peruana por cerca de 15, 000 pessoas, incluindo monolíngüe e bilíngüe. Esta é uma estimativa que tenta refletir a realidade atual, considerando o crescimento populacional desde a última população e censo habitacional realizado no Peru em 1993. A análise proposta se limita ao estudo do sistema verbal em frases simples variedade shawi falado nas margens do rio Sillay. O primeiro capítulo discute brevemente o problema do estudo da língua, a lógica e os objectivos. No segundo capítulo apresenta o referencial teórico, os fundamentos da teoria lingüística relacionadas com as noções de discurso, linguagem e, especialmente, verbo, classes verbais, atuantes, espectadores, os processos de aumento e diminuição da valência de verbos. Neste capítulo apresentamos um quadro sobre as pessoas shawi, linguagem e estudos existentes sobre o assunto. O terceiro capítulo trata da análise fonológica e morfofonológica da língua e as tentativas de trazer o leitor para o conhecimento da língua nestes níveis. A apresentação está relacionado com os fonemas segmentais, então precisamos de mais estudos sobre as características supra-segmentais. O quarto capítulo trata da análise morfossintática da língua. Ela começa com uma descrição dos aspectos gerais da linguagem em sua morfossintaxe: tipo de linguagem, tipos de estrutura pregação, a palavra estrutura da frase, etc. Estes dados irão ajudar o leitor quando este sistema de análise verbal. O capítulo continua com a apresentação do sistema verbal: verbo, classes verbais, morfologia verbal (morfemas que coalescem ao radical verbal) predicado verbal, atuantes, funções sintáticas, etc. Termina com as mudanças que podem ocorrer no predicado verbal. Nós tentamos terminar o trabalho com algumas conclusões
2

A place for the Shawi in the history of Maynas / Un lugar para los shawi en la historia de Maynas

González Saavedra, María Luisa 25 September 2017 (has links)
Este texto pretende recabar las noticias que, sobre los shawi, seregistran en las fuentes escritas de la provincia de Maynas. El objetivo es acercarse, desde una perspectiva antropológica, a una sociedad que ya en el siglo XVI fue retratada desde la óptica de la evangelización. Siguiendo la cronología de las notas escritas por algunos de los conquistadores y misioneros españoles que llegaron a sus tierras, dibujaremos la silueta de un grupo que ha llegado a nuestros días posicionándose a la sombra de sus grupos vecinos: por un lado, los shiwilu, indios modelo de la evangelización jesuita; por otro, los awajun, quienes lograron vivir en su ‘gentilidad’, esto es, fuera de los límites misionales. Esta aparente neutralidad es la que define hoy a la sociedad shawi, que se siente indígena y cristiana a la vez. / This text aims to make a compilation of the news about the Shawifound in written sources concerning the History of Maynas. Its purpose is to approach a society already portrayed in the sixteen century from the standpoint of evangelization, considering now its anthropological perspective. Following the chronology of noteswritten by some of the Spanish conquistadors and missionaries who came to take over their land, we will draw the silhouette of a group that has reached our days by positioning itself in the shadow of its neighboring groups: on one hand, the Shiwilu, the model indig- enous group evangelized by the Jesuit order; secondly, the Awajun, who managed to keep their ‘paganism’, i.e., to remain their selves outside the mission boundaries. This apparent neutrality is what defines today the Shawi society: a society which identifies itself as indigenous and Christian at once.
3

Vigilância da leishmaniose visceral americana no município de São Paulo / Surveillance of American visceral leishmaniasis in São Paulo municipality

Alessandra Ferreira da Silva 14 August 2015 (has links)
Introdução: As leishmanioses são doenças que se apresentam como um sério obstáculo ao desenvolvimento socioeconômico. A leishmaniose visceral americana (LVA) tem como agente etiológico a Leishmania (Leishmania) infantum chagasi, como reservatório doméstico principal o cão e os vetores são flebotomíneos (Diptera:Psychodidae). Objetivo: investigar a vulnerabilidade do município de São Paulo para a ocorrência de LVA, utilizando os parâmetros de casos humanos notificados, presença do vetor e infecção em reservatórios domésticos. Método: A área de estudo compreende a região dos distritos administrativos do Anhanguera, Jaraguá e Perus (município de São Paulo) que incluem o Parque do Anhanguera e o Parque estadual do Jaraguá. A justificativa para o estudo nessa área é o eixo viário oeste-leste de expansão da LVA no estado de São Paulo. Foram levantados notificações humanas de LVA entre os anos de 2007 a 2014, para análise espacial pelos programas SaTScan e Terra View, num total de 140 e nenhuma dessas é considerada autóctone. Realizamos levantamento entomológico nos parques Anhanguera e Jaraguá. A análise estatística foi realizada pelos cálculos da Média geométrica de Williams, pelo índice de diversidade de Shannon-Weaver (H) e a dominância pelo índice de Pielou (J) também foi calculado o índice de Abundância de espécies padronizado (IAEP). Realizamos inquérito canino amostral e obtivemos 126 amostras de sangue canino que foram submetidas aos testes EIE. Foram colhidas amostras de Swab bucal do cão sororreagente e contactantes, as quais foram analisadas por PCR (RFLP), juntamente ás amostras de coágulos sanguíneos dos cães dos parques Anhanguera e Jaraguá num total de 31 amostras. Resultado: A análise espacial mostrou Clusters nos distritos do Brás e Guaianases (p<0,05) e, a espaço temporal em Raposo Tavares e Parelheiros (p<0,05). Os distritos do Carrão, Cachoeirinha e José Bonifácio formaram clusters secundários (p>0,05). Foram capturados 3660 espécimes de flebotomíneos identificadas 16 espécies de flebotomíneos e as mais frequentes na amostra foram: Pintomyia fischeri (82,46 por cento ), Psathyromyia pascalei (5,57 por cento ), Migonemyia migonei (5.25 por cento ) e Expapillata firmatoi (3.22 por cento ). Dentre as espécies capturadas, está uma fêmea de espécie similar à Lutzomyia longipalpis. O inquérito canino sorológico apontou um sororreagente no distrito de Perus. Do total de 31 amostras analisadas por PCR, 10 foram positivas para Leishmania sp. Foi possível chegar á espécie em seis delas, três positivas para a espécie L. (V.) shawi ou L (V.) lainsoni e três para L. (L.) infantum chagasi. Conclusões: A análise espacial das notificações de LVA humana dá direcionamento para investigações de uma possível transmissão autóctone no município. Há elos epidemiológicos que sugerem que as leishmanioses tegumentar e visceral caninas se tratam de doenças emergentes no município. Possivelmente, os casos caninos encontrados na região de estudo sejam parte da disseminação do eixo oeste-leste da leishmaniose visceral no Estado de São Paulo, pelo eixo viário. Palavras-chave: Leishmaniose visceral canina; Leishmaniose tegumentar. / Introduction: The leishmaniases are diseases which are a serious obstacle to social economic development. American visceral leishmaniasis (AVL) has Leishmania (Leishmania) infantum chagasi as its etiological agent, the domestic dog is its main reservoir and sand flies (Diptera, Psychodidae) its vectors. Objective: to investigate the vulnerability of São Paulo municipality to the occurrence of AVL, using the parameters of notified human cases, the presence of the vector and infection in domestic reservoirs. Method: The study area covers the region of the distinct administrative districts of Anhanguera, Jaraguá and Perus (São Paulo municipality) which include the Parque do Anhanguera and the Parque Estadual do Jaraguá. The reason for undertaking the study in this area is the existence of the roads linking the west and east of São Paulo state along which AVL has expanded eastwards. A survey was made of the 140 human cases (none of which was considered autochthonous) of AVL notified from 2007 to 2014, for the spatial analysis of the SaTScan and Terra View programs. An entomological survey was conducted in the two parks mentioned. The statistical analyses of the insects were undertaken using Williams geometrical means, Shannon-Weavers diversity index (H), Pielous evenness index (J) and the standardized species abundance index (SSAI). A canine sampling inquiry was conducted and 126 blood samples were submitted to the Enzyme-Linked Immunosorbent Assay (ELISA) test. A total of five samples of mouth swabs of the serum positive dog and four of its contacts and also blood clot samples of a total of 26 dogs from the two parks were analyzed by PCR (RFLP). Results: The spatial analysis showed clusters in the Brás and Guaianases (p<0.05) districts and the temporal/spatial analysis in Raposo Tavares and Parelheiros (p<0.05) districts. The Carrão, Cachoeirinha and José Bonifácio districts formed secondary clusters (p>0.05). A total of 3,660 specimens of sand flies were collected, representing 16 species, Pintomyia fischeri (82.46 per cent ), Psathyromyia pascalei (5.57 per cent ), Migonemyia migonei (5.25 per cent ) and Expapillata firmatoi (3.22 per cent ) being the most frequent. One female of a species similar to Lutzomyia longipalpis was captured. The canine serological enquiry showed one reagent in the Perus district. Of the total of 31 samples analyzed by PCR, 10 were positive for Leishmania sp., among which six were identified, three as species L. (V.) shawi/L (V.) lainsoni and three as L. (L.) infantum chagasi. Conclusions: The spatial analysis of the AVL human cases notified suggests the direction to be followed for future investigation of a possible autochthonous transmission in the municipality. There are epidemiological links which suggest that the canine cutaneous and visceral leishmaniases are emergent diseases in the municipality. Possibly the canine cases of visceral leishmaniasis found in this study region are part of its dissemination along the west-east axis of the diseases expansion in the state of São Paulo along the highways.
4

Vigilância da leishmaniose visceral americana no município de São Paulo / Surveillance of American visceral leishmaniasis in São Paulo municipality

Silva, Alessandra Ferreira da 14 August 2015 (has links)
Introdução: As leishmanioses são doenças que se apresentam como um sério obstáculo ao desenvolvimento socioeconômico. A leishmaniose visceral americana (LVA) tem como agente etiológico a Leishmania (Leishmania) infantum chagasi, como reservatório doméstico principal o cão e os vetores são flebotomíneos (Diptera:Psychodidae). Objetivo: investigar a vulnerabilidade do município de São Paulo para a ocorrência de LVA, utilizando os parâmetros de casos humanos notificados, presença do vetor e infecção em reservatórios domésticos. Método: A área de estudo compreende a região dos distritos administrativos do Anhanguera, Jaraguá e Perus (município de São Paulo) que incluem o Parque do Anhanguera e o Parque estadual do Jaraguá. A justificativa para o estudo nessa área é o eixo viário oeste-leste de expansão da LVA no estado de São Paulo. Foram levantados notificações humanas de LVA entre os anos de 2007 a 2014, para análise espacial pelos programas SaTScan e Terra View, num total de 140 e nenhuma dessas é considerada autóctone. Realizamos levantamento entomológico nos parques Anhanguera e Jaraguá. A análise estatística foi realizada pelos cálculos da Média geométrica de Williams, pelo índice de diversidade de Shannon-Weaver (H) e a dominância pelo índice de Pielou (J) também foi calculado o índice de Abundância de espécies padronizado (IAEP). Realizamos inquérito canino amostral e obtivemos 126 amostras de sangue canino que foram submetidas aos testes EIE. Foram colhidas amostras de Swab bucal do cão sororreagente e contactantes, as quais foram analisadas por PCR (RFLP), juntamente ás amostras de coágulos sanguíneos dos cães dos parques Anhanguera e Jaraguá num total de 31 amostras. Resultado: A análise espacial mostrou Clusters nos distritos do Brás e Guaianases (p<0,05) e, a espaço temporal em Raposo Tavares e Parelheiros (p<0,05). Os distritos do Carrão, Cachoeirinha e José Bonifácio formaram clusters secundários (p>0,05). Foram capturados 3660 espécimes de flebotomíneos identificadas 16 espécies de flebotomíneos e as mais frequentes na amostra foram: Pintomyia fischeri (82,46 por cento ), Psathyromyia pascalei (5,57 por cento ), Migonemyia migonei (5.25 por cento ) e Expapillata firmatoi (3.22 por cento ). Dentre as espécies capturadas, está uma fêmea de espécie similar à Lutzomyia longipalpis. O inquérito canino sorológico apontou um sororreagente no distrito de Perus. Do total de 31 amostras analisadas por PCR, 10 foram positivas para Leishmania sp. Foi possível chegar á espécie em seis delas, três positivas para a espécie L. (V.) shawi ou L (V.) lainsoni e três para L. (L.) infantum chagasi. Conclusões: A análise espacial das notificações de LVA humana dá direcionamento para investigações de uma possível transmissão autóctone no município. Há elos epidemiológicos que sugerem que as leishmanioses tegumentar e visceral caninas se tratam de doenças emergentes no município. Possivelmente, os casos caninos encontrados na região de estudo sejam parte da disseminação do eixo oeste-leste da leishmaniose visceral no Estado de São Paulo, pelo eixo viário. Palavras-chave: Leishmaniose visceral canina; Leishmaniose tegumentar. / Introduction: The leishmaniases are diseases which are a serious obstacle to social economic development. American visceral leishmaniasis (AVL) has Leishmania (Leishmania) infantum chagasi as its etiological agent, the domestic dog is its main reservoir and sand flies (Diptera, Psychodidae) its vectors. Objective: to investigate the vulnerability of São Paulo municipality to the occurrence of AVL, using the parameters of notified human cases, the presence of the vector and infection in domestic reservoirs. Method: The study area covers the region of the distinct administrative districts of Anhanguera, Jaraguá and Perus (São Paulo municipality) which include the Parque do Anhanguera and the Parque Estadual do Jaraguá. The reason for undertaking the study in this area is the existence of the roads linking the west and east of São Paulo state along which AVL has expanded eastwards. A survey was made of the 140 human cases (none of which was considered autochthonous) of AVL notified from 2007 to 2014, for the spatial analysis of the SaTScan and Terra View programs. An entomological survey was conducted in the two parks mentioned. The statistical analyses of the insects were undertaken using Williams geometrical means, Shannon-Weavers diversity index (H), Pielous evenness index (J) and the standardized species abundance index (SSAI). A canine sampling inquiry was conducted and 126 blood samples were submitted to the Enzyme-Linked Immunosorbent Assay (ELISA) test. A total of five samples of mouth swabs of the serum positive dog and four of its contacts and also blood clot samples of a total of 26 dogs from the two parks were analyzed by PCR (RFLP). Results: The spatial analysis showed clusters in the Brás and Guaianases (p<0.05) districts and the temporal/spatial analysis in Raposo Tavares and Parelheiros (p<0.05) districts. The Carrão, Cachoeirinha and José Bonifácio districts formed secondary clusters (p>0.05). A total of 3,660 specimens of sand flies were collected, representing 16 species, Pintomyia fischeri (82.46 per cent ), Psathyromyia pascalei (5.57 per cent ), Migonemyia migonei (5.25 per cent ) and Expapillata firmatoi (3.22 per cent ) being the most frequent. One female of a species similar to Lutzomyia longipalpis was captured. The canine serological enquiry showed one reagent in the Perus district. Of the total of 31 samples analyzed by PCR, 10 were positive for Leishmania sp., among which six were identified, three as species L. (V.) shawi/L (V.) lainsoni and three as L. (L.) infantum chagasi. Conclusions: The spatial analysis of the AVL human cases notified suggests the direction to be followed for future investigation of a possible autochthonous transmission in the municipality. There are epidemiological links which suggest that the canine cutaneous and visceral leishmaniases are emergent diseases in the municipality. Possibly the canine cases of visceral leishmaniasis found in this study region are part of its dissemination along the west-east axis of the diseases expansion in the state of São Paulo along the highways.
5

Estudo de algumas populações de Lutzomyia (Nyssomyia) whitmani (Atunes & Coutinho, 1939) (Díptera: Psychodidae: Phlebotominae) procedentes de áreas de transmissão de Leishmaniose Tegumentar Americana no norte e nordeste do Brasil

Silva, Daniel Motta da January 2010 (has links)
Submitted by Anderson Silva (avargas@icict.fiocruz.br) on 2012-07-06T17:37:06Z No. of bitstreams: 1 daniel_m_silva_ioc_bp_0026_2010.pdf: 1427559 bytes, checksum: 532cc287ce2cf619826a2b8055638b91 (MD5) / Made available in DSpace on 2012-07-06T17:37:06Z (GMT). No. of bitstreams: 1 daniel_m_silva_ioc_bp_0026_2010.pdf: 1427559 bytes, checksum: 532cc287ce2cf619826a2b8055638b91 (MD5) Previous issue date: 2010 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil. / Lutzomyia (Nyssomyia) whitmani é incriminado como vetor de Leishmaniose Tegumentar Americana (LTA), associada à transmissão de duas leishmânias dermotrópicas: Leishmania (Viannia) braziliensis e Leishmania (Viannia) shawi. No entanto, além da competência comprovada para transmitir dois parasitos, diferenças no comportamento entre populações geograficamente distintas têm sugerido que esta não seria uma única espécie e sim um complexo de espécies crípticas. A segura identificação destas populações é de fundamental importância para os estudos eco-epidemiológicos da LTA, possibilitando o entendimento dos ciclos de transmissão, uma vez que esta espécie ocorre na grande maioria dos estados brasileiros. No presente estudo foi avaliada a variabilidade genética de populações L. (N.) whitmani procedentes de Buriticupu (MA), área de transmissão de Le. (V.) shawi e Le. (V.) braziliensis, de Paragominas (PA), de transmissão de Le. (V.) shawi, e de Ilhéus (BA), localidade tipo, e de Meruoca (CE), áreas de transmissão de Le. (V.) braziliensis. A partir das análises por RAPD-PCR e sequenciamento do gene do Citocromo b foi possível observar três agrupamentos, onde os espécimes de Buriticupu e Paragominas compõem o mesmo grupo, os de Ilhéus formaram um segundo grupo e os de Meruoca o terceiro. As análises mostram um alto grau de diferenciação e sugerem que os três agrupamentos possam representar diferentes espécies crípticas do “complexo” whitmani. / Lutzomyia (Nyssomyia) whitmani is incriminated as vectors of leishmaniasis (ACL) associated with the transmission of two leishmania dermotropic: Leishmania (Viannia) braziliensis and Leishmania (Viannia) shawi. However, in addition to proven competence to transmit two parasites, differences in behavior between geographically distinct populations have suggested that this would not be a single species but a complex of cryptic species. The secure identification of these populations is of fundamental importance to the eco-epidemiological studies of LTA, allowing for better understanding of transmission cycles, since this species occurs in most Brazilian states. In this study we evaluated the genetic variability of populations L. (N.) whitmani coming Buriticupu (MA) transmission area of Le. (V.) shawi and Le. (V.) braziliensis, Paragominas (PA), transmission of Le. (V.) shawi, and Ilhéus (BA), type locality, and Meruoca (CE), transmission area of Le. (V.) braziliensis. From the analysis by RAPD-PCR and sequencing of the cytochrome b gene it was possible to observe three clusters, where the specimens Buriticupu and Paragominas comprise the same group, from Ilhéus formed a second group and from Meruoca of the third. The analysis shows a high degree of differentiation and suggests that the three groups may represent different cryptic species “whitmani complex”.
6

Centro de interpretación de la producción cultural indígena shawi a través de la arquitectura fenomenológica en la ciudad de Yurimaguas / Interpretation Center of Shawi Indigenous Cultural Production through Phenomenological Architecture in the city of Yurimaguas

Beltran Gala, Maria Fernanda Damaris 09 November 2021 (has links)
La comunidad Indígena Shawi, es parte del distrito de Yurimaguas, además de una de la más representativa de la Región Loreto, ya que parte de la población Amazónica, desciende a partir de esta cultura. Además, generan recursos económicos y una representación cultural hacia la zona. Pese a esto, se encuentran en peligro de extinción, debido a que sus territorios y modo de vida se ven afectados por las industrias que los invaden, así como también, la falta de identidad cultural en esta zona, respecto a esta comunidad. De este modo, se pretende contribuir con el desarrollo y sensibilización mediante la apreciación de sus expresiones culturales. Asimismo, incentivar a la concientización, aprovechando también, la potencialidad Shawi para el crecimiento turístico en el distrito. / The Shawi Indigenous community is part of the Yurimaguas district, in addition to one of the most representative of the Loreto Region, since part of the Amazonian population descends from this culture. In addition, they generate economic resources and a cultural representation towards the area. Despite this, they are in danger of extinction, because their territories and way of life are affected by the industries that invade them, as well as the lack of cultural identity in this area, with respect to this community. In this way, it is intended to contribute to the development and awareness through the appreciation of their cultural expressions. Also, encourage awareness, also taking advantage of Shawi potential for tourism growth in the district. / Trabajo de investigación
7

Étude des propriétés antidiabétiques de Nigella sativa : sites d’action cellulaires et moléculaires

Benhaddou Andaloussi, Ali 02 1900 (has links)
Nigella sativa ou cumin noir est une plante et un condiment populaires. Les graines de N. sativa sont très utilisées en médecine traditionnelle des pays nord africains pour le traitement du diabète. Cependant, les mécanismes d'actions cellulaires et moléculaires via lesquels cette plante exerce son effet euglycémiant restent encore mal compris. Le but de notre étude est d'examiner l’effet de N. sativa sur la sécrétion d’insuline, le transport de glucose et sur les voies de signalisation impliquées dans l’homéostasie et le métabolisme de glucose, en utilisant des essais biologiques sur des cultures cellulaires murines (cellules β pancréatiques βTC, myoblastes C2C12, hépatocytes H4IIE et adipocytes 3T3-L1) et des études in vivo chez le rat normoglycémique et le Meriones shawi (rongeur) diabétique. Chez les cellules β pancréatiques, N. sativa a augmenté leur prolifération ainsi que la sécrétion basale et gluco-stimulée de l’insuline. N. sativa a augmenté aussi la prise de glucose de 50% chez les cellules musculaires alors que chez les cellules graisseuses, la prise de glucose est augmentée jusqu’au 400%. Les expériences d’immunobuvardage de type western ont montré que N. sativa stimule les voies de signalisation de l’insuline (Akt et ERKs) et aussi celle insulino-indépendante (AMPK) chez les cellules C2C12. Par contre, chez les 3T3-L1, l’augmentation de transport de glucose est plutôt reliée à une activation de la voie de peroxisome proliferator activated receptor γ (PPARγ). Chez les hépatocytes, N. sativa augmente la stimulation des protéines intracellulaires Akt et 5' adenosine monophosphate-activated protein kinase (AMPK). Cette activation de l’AMPK est associée à un effet découpleur de la plante au niveau de la phosphorylation oxydative mitochondriale. Par ailleurs, chez les Meriones shawi diabétiques, N. sativa diminue graduellement la glycémie à jeun ainsi que la réponse glycémique (AUC) à une charge orale en glucose (OGTT) pour atteindre des valeurs semblables aux animaux témoins après quatre semaines de traitement. Une amélioration du profile lipidique est observée autant chez les Meriones shawi diabétiques que chez les rats normaux. Au niveau moléculaire, N. sativa augmente le contenu musculaire en glucose transporter 4 Glut4 et la phosphorylation de l’acetyl-coenzyme A carboxylase ACC dans le muscle soléaire et le foie chez les Mériones shawi diabétiques. Par contre, chez le rat normal, on assiste à une stimulation des voies de signalisation de l’insuline (Akt et ERK) au niveau hépatique. En conclusion, nous avons confirmé l’action insulinotropique de N. sativa au niveau des cellules β pancréatiques et mis en évidence un effet proliférateur pouvant potentiellement s’avérer utile pour contrecarrer la perte de masse cellulaire observée chez les diabétiques. Notre étude a également mis en évidence pour la première fois que N. sativa exerce son activité antidiabétique par une combinaison d’effets insulino-mimétiques et insulino-sensibilisateurs directs permettant ainsi d’augmenter le transport de glucose des tissus périphériques. Cette action de N. sativa est liée à une stimulation des voies de signalisation intracellulaires insulinodépendantes et -indépendantes (AMPK) chez le muscle squelettique et le foie alors qu’elle passe par la voie des PPARγ au niveau du tissu adipeux. Finalement, l’étude in vivo vient confirmer l’effet antidiabétique de N. sativa. Notre apport novateur se situe au niveau de la démonstration que l’activité antidiabétique de N. sativa chez le Meriones shawi diabétique est la résultante des mêmes activités que celles déterminées au niveau de l’étude in vitro. En effet, N. sativa active la voie de l’AMPK, améliore la sensibilité à l’insuline et augmente l’insulinémie. Notre étude montre aussi que N. sativa possède une activité antilipidémiante. Ces résultats confirment le bien-fondé de l'utilisation ethnopharmacologique de N. sativa comme traitement du diabète et des perturbations du métabolisme lipidique qui y sont associées. De plus, les actions pléiotropiques de N. sativa en font un traitement alternatif ou complémentaire du diabète très prometteur qui encouragent à présent la tenue d’études cliniques de bonne qualité. / Nigella sativa or black cumin is a medicinal plant and a popular condiment. The seeds of N. sativa are widely used in the traditional medicine of North African countries for the treatment of diabetes. However, the cellular and molecular mechanisms of action through which the plant exerts its hypoglycemic effect remain unclear. The aim of our study is to determine the effect of N. sativa on insulin secretion, glucose transport and signaling pathways involved in the regulation of glucose homeostasis and metabolism. We carried out in vitro murine cell-based bioassays (βTC pancreatic β cells, C2C12 myoblasts, H4IIE hepatocytes and 3T3-L1 adipocytes) and in vivo studies in normoglycemic rats and diabetic Meriones shawi (rodent). In pancreatic β cells, N. sativa increased cell proliferation as well as basal and glucose stimulated insulin secretion. It also enhanced glucose uptake in muscle cells by 50%. Moreover, the increase of glucose uptake in fat cells reached levels up to 400%. The experiments using Western immunoblot analysis showed that N. sativa stimulated insulin-dependent (Akt and ERK) as well as -independent (AMPK) pathways in C2C12 cells. In 3T3-L1 cells, the increase of glucose uptake was attributed to the activation of the peroxisome proliferator activated receptor γ (PPARγ) pathway. Similarly to C2C12 cells, N. sativa activated Akt and 5' adenosine monophosphate-activated protein kinase (AMPK) in hepatocytes. This activation of AMPK was associated with an uncoupling effect on mitochondrial oxidative phosphorylation. In diabetic Meriones, N. sativa gradually decreased fasting blood glucose and the glycemic response to an oral glucose load (OGTT) to values similar to normal animals at the end of treatment. Improved lipid profile is observed in both animal models. At the molecular level, N. sativa increased muscle glucose transporter 4 (Glut4) content and acetyl-coenzyme A carboxylase (ACC) phosphorylation in soleus muscle and liver in diabetic Meriones shawi. In normal rats, the plant extract induced a stimulation of insulin signaling pathways (Akt and ERK) in the liver. In conclusion, N. sativa has an insulinotropic effect on pancreatic β cells. Our study has revealed for the first time that N. sativa exerts its antidiabetic activity by a combination of insulino-mimetic and insulin-sensitizing effects, thereby increasing glucose uptake in peripheral tissues. This effect of N. sativa is linked to the stimulation of insulin-dependent and -independent (AMPK) pathway in skeletal muscle and liver, while in adipose tissue, the effect was attributed to the activation of PPARγ. Finally, the in vivo study confirms the antidiabetic and antihyperlipidemic effects of N. sativa. Our original contribution lies in the demonstration that the in vivo antidiabetic action of N. sativa is exerted though the same mechanisms identified by our in vitro studies. These data support the soundness of the ethnobotanical use of this plant for the treatment of diabetes and its associated dyslipidemia. Moreover, the pleiotropic actions of N. sativa make it a very promising alternative or complementary treatment for diabetes, which calls for immediate high quality clinical trials.
8

Étude des propriétés antidiabétiques de Nigella sativa : sites d’action cellulaires et moléculaires

Benhaddou Andaloussi, Ali 02 1900 (has links)
Nigella sativa ou cumin noir est une plante et un condiment populaires. Les graines de N. sativa sont très utilisées en médecine traditionnelle des pays nord africains pour le traitement du diabète. Cependant, les mécanismes d'actions cellulaires et moléculaires via lesquels cette plante exerce son effet euglycémiant restent encore mal compris. Le but de notre étude est d'examiner l’effet de N. sativa sur la sécrétion d’insuline, le transport de glucose et sur les voies de signalisation impliquées dans l’homéostasie et le métabolisme de glucose, en utilisant des essais biologiques sur des cultures cellulaires murines (cellules β pancréatiques βTC, myoblastes C2C12, hépatocytes H4IIE et adipocytes 3T3-L1) et des études in vivo chez le rat normoglycémique et le Meriones shawi (rongeur) diabétique. Chez les cellules β pancréatiques, N. sativa a augmenté leur prolifération ainsi que la sécrétion basale et gluco-stimulée de l’insuline. N. sativa a augmenté aussi la prise de glucose de 50% chez les cellules musculaires alors que chez les cellules graisseuses, la prise de glucose est augmentée jusqu’au 400%. Les expériences d’immunobuvardage de type western ont montré que N. sativa stimule les voies de signalisation de l’insuline (Akt et ERKs) et aussi celle insulino-indépendante (AMPK) chez les cellules C2C12. Par contre, chez les 3T3-L1, l’augmentation de transport de glucose est plutôt reliée à une activation de la voie de peroxisome proliferator activated receptor γ (PPARγ). Chez les hépatocytes, N. sativa augmente la stimulation des protéines intracellulaires Akt et 5' adenosine monophosphate-activated protein kinase (AMPK). Cette activation de l’AMPK est associée à un effet découpleur de la plante au niveau de la phosphorylation oxydative mitochondriale. Par ailleurs, chez les Meriones shawi diabétiques, N. sativa diminue graduellement la glycémie à jeun ainsi que la réponse glycémique (AUC) à une charge orale en glucose (OGTT) pour atteindre des valeurs semblables aux animaux témoins après quatre semaines de traitement. Une amélioration du profile lipidique est observée autant chez les Meriones shawi diabétiques que chez les rats normaux. Au niveau moléculaire, N. sativa augmente le contenu musculaire en glucose transporter 4 Glut4 et la phosphorylation de l’acetyl-coenzyme A carboxylase ACC dans le muscle soléaire et le foie chez les Mériones shawi diabétiques. Par contre, chez le rat normal, on assiste à une stimulation des voies de signalisation de l’insuline (Akt et ERK) au niveau hépatique. En conclusion, nous avons confirmé l’action insulinotropique de N. sativa au niveau des cellules β pancréatiques et mis en évidence un effet proliférateur pouvant potentiellement s’avérer utile pour contrecarrer la perte de masse cellulaire observée chez les diabétiques. Notre étude a également mis en évidence pour la première fois que N. sativa exerce son activité antidiabétique par une combinaison d’effets insulino-mimétiques et insulino-sensibilisateurs directs permettant ainsi d’augmenter le transport de glucose des tissus périphériques. Cette action de N. sativa est liée à une stimulation des voies de signalisation intracellulaires insulinodépendantes et -indépendantes (AMPK) chez le muscle squelettique et le foie alors qu’elle passe par la voie des PPARγ au niveau du tissu adipeux. Finalement, l’étude in vivo vient confirmer l’effet antidiabétique de N. sativa. Notre apport novateur se situe au niveau de la démonstration que l’activité antidiabétique de N. sativa chez le Meriones shawi diabétique est la résultante des mêmes activités que celles déterminées au niveau de l’étude in vitro. En effet, N. sativa active la voie de l’AMPK, améliore la sensibilité à l’insuline et augmente l’insulinémie. Notre étude montre aussi que N. sativa possède une activité antilipidémiante. Ces résultats confirment le bien-fondé de l'utilisation ethnopharmacologique de N. sativa comme traitement du diabète et des perturbations du métabolisme lipidique qui y sont associées. De plus, les actions pléiotropiques de N. sativa en font un traitement alternatif ou complémentaire du diabète très prometteur qui encouragent à présent la tenue d’études cliniques de bonne qualité. / Nigella sativa or black cumin is a medicinal plant and a popular condiment. The seeds of N. sativa are widely used in the traditional medicine of North African countries for the treatment of diabetes. However, the cellular and molecular mechanisms of action through which the plant exerts its hypoglycemic effect remain unclear. The aim of our study is to determine the effect of N. sativa on insulin secretion, glucose transport and signaling pathways involved in the regulation of glucose homeostasis and metabolism. We carried out in vitro murine cell-based bioassays (βTC pancreatic β cells, C2C12 myoblasts, H4IIE hepatocytes and 3T3-L1 adipocytes) and in vivo studies in normoglycemic rats and diabetic Meriones shawi (rodent). In pancreatic β cells, N. sativa increased cell proliferation as well as basal and glucose stimulated insulin secretion. It also enhanced glucose uptake in muscle cells by 50%. Moreover, the increase of glucose uptake in fat cells reached levels up to 400%. The experiments using Western immunoblot analysis showed that N. sativa stimulated insulin-dependent (Akt and ERK) as well as -independent (AMPK) pathways in C2C12 cells. In 3T3-L1 cells, the increase of glucose uptake was attributed to the activation of the peroxisome proliferator activated receptor γ (PPARγ) pathway. Similarly to C2C12 cells, N. sativa activated Akt and 5' adenosine monophosphate-activated protein kinase (AMPK) in hepatocytes. This activation of AMPK was associated with an uncoupling effect on mitochondrial oxidative phosphorylation. In diabetic Meriones, N. sativa gradually decreased fasting blood glucose and the glycemic response to an oral glucose load (OGTT) to values similar to normal animals at the end of treatment. Improved lipid profile is observed in both animal models. At the molecular level, N. sativa increased muscle glucose transporter 4 (Glut4) content and acetyl-coenzyme A carboxylase (ACC) phosphorylation in soleus muscle and liver in diabetic Meriones shawi. In normal rats, the plant extract induced a stimulation of insulin signaling pathways (Akt and ERK) in the liver. In conclusion, N. sativa has an insulinotropic effect on pancreatic β cells. Our study has revealed for the first time that N. sativa exerts its antidiabetic activity by a combination of insulino-mimetic and insulin-sensitizing effects, thereby increasing glucose uptake in peripheral tissues. This effect of N. sativa is linked to the stimulation of insulin-dependent and -independent (AMPK) pathway in skeletal muscle and liver, while in adipose tissue, the effect was attributed to the activation of PPARγ. Finally, the in vivo study confirms the antidiabetic and antihyperlipidemic effects of N. sativa. Our original contribution lies in the demonstration that the in vivo antidiabetic action of N. sativa is exerted though the same mechanisms identified by our in vitro studies. These data support the soundness of the ethnobotanical use of this plant for the treatment of diabetes and its associated dyslipidemia. Moreover, the pleiotropic actions of N. sativa make it a very promising alternative or complementary treatment for diabetes, which calls for immediate high quality clinical trials.

Page generated in 0.0419 seconds