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  • 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

Antimalarial and anticancer activities of selected South African Salvia species and isolated compounds from S. radula

Kamatou, GPP, Van Zyl, RL, Davids, H, Van Heerden, FR, Lourens, ACU, Viljoen, AM 26 November 2007 (has links)
Extracts of seventeen Salvia species used in traditional medicine in South Africa were subjected to biological testing. The potential ability to inhibit the in vitro growth/proliferation of Plasmodium falciparum (FCR-3 strain) and the cytotoxic effects on three human cancer cells [breast adenocarcinoma (MCF-7), colon adenocarcinoma (HT-29) and glioblastoma (SF-268)] and a human kidney epithelial cell line were investigated. The extracts displayed antimalarial activity with IC50 values ranging from 3.91 to 26.01 μg/ml and S. radula displaying the most favorable activity. Two compounds were subsequently isolated from the active fraction of S. radula and identified as betulafolientriol oxide and salvigenin. The two compounds displayed similar or lower antimalarial activity (IC50 values: 4.95 and 24.60 μg/ml, respectively) compared to the crude solvent extract. The concentration required to inhibit 50% of cancer cells ranged between 9.69 μg/ml and 43.65 μg/ml, and between 8.72 μg/ml and 59.12 μg/ml against the MCF-7 and SF-268 cell lines, respectively. The IC50 values determined for the HT-29 cell line ranged from 17.05 to 57.00 μg/ml, with S. lanceolata being the most active. The samples also displayed some degree of toxicity when tested against the human kidney epithelial cells, with IC50 values ranging from 12.12 to 53.34 μg/ml. The in vitro antimalarial and anticancer activities support the historic and present use of Salvia species in traditional medicine.
2

Smart nanocrystals of artemether: fabrication, characterization, and comparative in vitro and in vivo antimalarial evaluation

Shah, S.M.H., Ullah, F., Khan, Shahzeb, Shah, S.M.M., de Matas, Marcel, Hussain, Z., Minhas, M.U., AbdEl-Salam, N.M., Assi, Khaled H., Isreb, Mohammad 29 August 2016 (has links)
Yes / Artemether (ARTM) is a very effective antimalarial drug with poor solubility and consequently low bioavailability. Smart nanocrystals of ARTM with particle size of 161±1.5 nm and polydispersity index of 0.172±0.01 were produced in <1 hour using a wet milling technology, Dena® DM-100. The crystallinity of the processed ARTM was confirmed using differential scanning calorimetry and powder X-ray diffraction. The saturation solubility of the ARTM nanocrystals was substantially increased to 900 µg/mL compared to the raw ARTM in water (145.0±2.3 µg/mL) and stabilizer solution (300.0±2.0 µg/mL). The physical stability studies conducted for 90 days demonstrated that nanocrystals stored at 2°C-8°C and 25°C were very stable compared to the samples stored at 40°C. The nanocrystals were also shown to be stable when processed at acidic pH (2.0). The solubility and dissolution rate of ARTM nanocrystals were significantly increased (P<0.05) compared to those of its bulk powder form. The results of in vitro studies showed significant antimalarial effect (P<0.05) against Plasmodium falciparum and Plasmodium vivax. The IC50 (median lethal oral dose) value of ARTM nanocrystals was 28- and 54-fold lower than the IC50 value of unprocessed drug and 13- and 21-fold lower than the IC50 value of the marketed tablets, respectively. In addition, ARTM nanocrystals at the same dose (2 mg/kg) showed significantly (P<0.05) higher reduction in percent parasitemia (89%) against P. vivax compared to the unprocessed (27%), marketed tablets (45%), and microsuspension (60%). The acute toxicity study demonstrated that the LD50 value of ARTM nanocrystals is between 1,500 mg/kg and 2,000 mg/kg when given orally. This study demonstrated that the wet milling technology (Dena® DM-100) can produce smart nanocrystals of ARTM with enhanced antimalarial activities.
3

Joziknipholones A and B : the First Dimeric Phenylanthraquinones, from the Roots of Bulbine frutescens

Bringmann, Gerhard, Mutanyatta-Comar, Joan, Maksimenka, Katja, Wanjohi, John M., Heydenreich, Matthias, Brun, Reto, Müller, Werner E. G., Peter, Martin, Midiwo, Jacob O., Yenesew, Abi January 2008 (has links)
From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells.
4

Avaliação do potencial antimalárico de Norantea brasiliensis Choisy (Marcgraviaceae) cultivada in vitro e in vivo / Evaluation of potential antimalarial of Norantea brasiliensis choisy (Marcgraviaceae) grown in vitro and in vivo

Graziela da Silva Mello 28 February 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / A malária é uma doença infecciosa causada por protozoários do gênero Plasmodium, transmitidos ao homem, principalmente, através da picada do mosquito infectado. O tratamento é realizado por meio do uso de drogas, como a cloroquina, uma vez que não há vacina eficiente contra a doença. Porém, a resistência dos parasitos aos medicamentos tem levado à busca por novas substâncias com atividade antimalárica, inclusive de origem vegetal. Nesse contexto, o presente trabalho teve por objetivo avaliar a atividade antimalárica de extratos metanólicos de Norantea brasiliensis cultivada sob condições in vivo e in vitro, espécie nativa ocorrente em restingas, com potencial medicinal já comprovado para várias atividades. Foram desenvolvidos protocolos de calogênese e cultura de raízes da espécie visando à definição de um sistema de produção de metabólitos. Para a cultura in vitro, explantes foram inoculados em meio líquido e sólido contendo diferentes fitorreguladores e concentrações. A partir da cultura de tecidos, foram testados extratos do material produzido biotecnologicamente para comparação com o material botânico cultivado no campo. Os testes sobre o potencial antimalárico foram realizados in vivo, utilizando-se camundongos infectados pelo Plasmodium berghei ANKA, e in vitro utilizando o Plasmodium falciparum. Em seguida foram administrados a cloroquina e os extratos vegetais. A parasitemia foi observada seguindo os protocolos já estabelecidos pelo Laboratório de Imunofarmacologia do Instituto Oswaldo Cruz (IOC). Resultados mostraram que explantes foliares e caulinares de plantas germinadas in vitro, inoculados em meio sólido B5 suplementado com 2,0 mg.mL-1 de ANA, são as melhores fontes para a produção de raízes, apresentando maiores valores de peso fresco e peso seco, mostrando-se um sistema promissor para a produção in vitro de metabólitos da espécie. A avaliação da atividade antimalárica in vivo revelou seu potencial a partir de extrato de raízes de planta cultivada in vivo, na concentração de 50 mg/kg apresentando redução significativa da parasitemia quando comparada com o controle não tratado. Paralelamente, nos testes in vitro a concentração de 100 &#956;g/kg do extrato de raízes de planta cultivada in vivo apresentou diferença significativa quando comparada com as outras concentrações testadas e o controle negativo. Além disso, há uma tendência de aumento do efeito inibitório conforme o aumento da concentração do extrato. Os resultados indicam o potencial de atividade antimalárica em raízes de N. brasiliensis, sendo este estudo o primeiro realizado para a espécie / Malaria is an infectious disease caused by protozoa of the genus Plasmodium, transmitted to humans primarily through the bite of an infected mosquito. The treatment is accomplished through the use of drugs such as chloroquine, since there is no effective vaccine against the disease. However, the resistance of parasites to drugs has led to the search for new antimalarial substances, including vegetable. In this context, this study aimed to evaluate the antimalarial activity of methanol extracts of Norantea brasiliensis grown under conditions in vivo and in vitro, native species occurring in salt marshes, with proven medicinal potential for various activities. Protocols were developed callus and culture of roots of species in order to define a system for production of metabolites. For in vitro culture, explants were inoculated in liquid and solid media containing different growth regulators and concentrations. From the tissue culture material were tested extracts biotechnologically produced for comparison with plant material grown in the field. Tests on the potential in vivo antimalarial were performed using mice were infected by Plasmodium berghei ANKA, and in vitro using the Plasmodium falciparum. They were then administered chloroquine and plant extracts. The parasitemia was observed following the protocols established by the Laboratory of Immunopharmacology of the Oswaldo Cruz Institute (IOC). Results showed that stem and leaf explants of in vitro germinated seedlings were inoculated on B5 solid medium supplemented with 2.0 mg.mL-1 ANA, are the best sources for the production of roots, with highest values of fresh weight and dry weight and proved to be a promising system for in vitro production of metabolites of the species. The assessment of antimalarial activity in vivo has shown its potential to extract from plant roots grown in vivo at a concentration of 50 mg/kg showing significant reduction of parasitemia when compared with the untreated control. Similarly, in in vitro tests the concentration of 100 &#956;g/kg of extract of roots of plants grown in vivo showed a significant difference when compared with other tested concentrations and negative control. Furthermore, there is a tendency to increase the inhibitory effect with increasing extract concentration. The results indicate the potential for antimalarial activity in roots of N. brasiliensis, which is the first study conducted for the species.
5

Avaliação do potencial antimalárico de Norantea brasiliensis Choisy (Marcgraviaceae) cultivada in vitro e in vivo / Evaluation of potential antimalarial of Norantea brasiliensis choisy (Marcgraviaceae) grown in vitro and in vivo

Graziela da Silva Mello 28 February 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / A malária é uma doença infecciosa causada por protozoários do gênero Plasmodium, transmitidos ao homem, principalmente, através da picada do mosquito infectado. O tratamento é realizado por meio do uso de drogas, como a cloroquina, uma vez que não há vacina eficiente contra a doença. Porém, a resistência dos parasitos aos medicamentos tem levado à busca por novas substâncias com atividade antimalárica, inclusive de origem vegetal. Nesse contexto, o presente trabalho teve por objetivo avaliar a atividade antimalárica de extratos metanólicos de Norantea brasiliensis cultivada sob condições in vivo e in vitro, espécie nativa ocorrente em restingas, com potencial medicinal já comprovado para várias atividades. Foram desenvolvidos protocolos de calogênese e cultura de raízes da espécie visando à definição de um sistema de produção de metabólitos. Para a cultura in vitro, explantes foram inoculados em meio líquido e sólido contendo diferentes fitorreguladores e concentrações. A partir da cultura de tecidos, foram testados extratos do material produzido biotecnologicamente para comparação com o material botânico cultivado no campo. Os testes sobre o potencial antimalárico foram realizados in vivo, utilizando-se camundongos infectados pelo Plasmodium berghei ANKA, e in vitro utilizando o Plasmodium falciparum. Em seguida foram administrados a cloroquina e os extratos vegetais. A parasitemia foi observada seguindo os protocolos já estabelecidos pelo Laboratório de Imunofarmacologia do Instituto Oswaldo Cruz (IOC). Resultados mostraram que explantes foliares e caulinares de plantas germinadas in vitro, inoculados em meio sólido B5 suplementado com 2,0 mg.mL-1 de ANA, são as melhores fontes para a produção de raízes, apresentando maiores valores de peso fresco e peso seco, mostrando-se um sistema promissor para a produção in vitro de metabólitos da espécie. A avaliação da atividade antimalárica in vivo revelou seu potencial a partir de extrato de raízes de planta cultivada in vivo, na concentração de 50 mg/kg apresentando redução significativa da parasitemia quando comparada com o controle não tratado. Paralelamente, nos testes in vitro a concentração de 100 &#956;g/kg do extrato de raízes de planta cultivada in vivo apresentou diferença significativa quando comparada com as outras concentrações testadas e o controle negativo. Além disso, há uma tendência de aumento do efeito inibitório conforme o aumento da concentração do extrato. Os resultados indicam o potencial de atividade antimalárica em raízes de N. brasiliensis, sendo este estudo o primeiro realizado para a espécie / Malaria is an infectious disease caused by protozoa of the genus Plasmodium, transmitted to humans primarily through the bite of an infected mosquito. The treatment is accomplished through the use of drugs such as chloroquine, since there is no effective vaccine against the disease. However, the resistance of parasites to drugs has led to the search for new antimalarial substances, including vegetable. In this context, this study aimed to evaluate the antimalarial activity of methanol extracts of Norantea brasiliensis grown under conditions in vivo and in vitro, native species occurring in salt marshes, with proven medicinal potential for various activities. Protocols were developed callus and culture of roots of species in order to define a system for production of metabolites. For in vitro culture, explants were inoculated in liquid and solid media containing different growth regulators and concentrations. From the tissue culture material were tested extracts biotechnologically produced for comparison with plant material grown in the field. Tests on the potential in vivo antimalarial were performed using mice were infected by Plasmodium berghei ANKA, and in vitro using the Plasmodium falciparum. They were then administered chloroquine and plant extracts. The parasitemia was observed following the protocols established by the Laboratory of Immunopharmacology of the Oswaldo Cruz Institute (IOC). Results showed that stem and leaf explants of in vitro germinated seedlings were inoculated on B5 solid medium supplemented with 2.0 mg.mL-1 ANA, are the best sources for the production of roots, with highest values of fresh weight and dry weight and proved to be a promising system for in vitro production of metabolites of the species. The assessment of antimalarial activity in vivo has shown its potential to extract from plant roots grown in vivo at a concentration of 50 mg/kg showing significant reduction of parasitemia when compared with the untreated control. Similarly, in in vitro tests the concentration of 100 &#956;g/kg of extract of roots of plants grown in vivo showed a significant difference when compared with other tested concentrations and negative control. Furthermore, there is a tendency to increase the inhibitory effect with increasing extract concentration. The results indicate the potential for antimalarial activity in roots of N. brasiliensis, which is the first study conducted for the species.
6

Caracterização química e potencial antimalárico de Andira nitida Mart. ex Benth / Chemical characterization and antimalarial potential of Andira nitida Mart. ex Benth

Ferreira, Antônio Vinícius Doriguetto 30 July 2013 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-28T11:14:22Z No. of bitstreams: 1 antonioviniciusdoriguettoferreira.pdf: 2820060 bytes, checksum: 3ecff4ce032ebee730a9907d3248b98a (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-28T12:25:03Z (GMT) No. of bitstreams: 1 antonioviniciusdoriguettoferreira.pdf: 2820060 bytes, checksum: 3ecff4ce032ebee730a9907d3248b98a (MD5) / Made available in DSpace on 2016-06-28T12:25:03Z (GMT). No. of bitstreams: 1 antonioviniciusdoriguettoferreira.pdf: 2820060 bytes, checksum: 3ecff4ce032ebee730a9907d3248b98a (MD5) Previous issue date: 2013-07-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / As espécies do gênero Andira (Fabaceae), popularmente conhecidas como “angelins”, destacam-se pelo uso popular como febrífugas, vermífugas e antimaláricas. Apesar das evidências da atividade antimalárica das espécies do gênero, existe uma carência de estudos químicos e biológicos em torno da espécie Andira nitida. Desta forma, este trabalho objetivou estabelecer o perfil químico e avaliar o potencial biológico de A. nitida, a fim de encontrar uma possível opção de novos alvos terapêuticos para o tratamento da malária. O perfil químico foi estabelecido por cromatografia em camada delgada (CCD) e cromatografia em fase líquida de alta eficiência (CLAE), após a análise dos cromatogramas constatou-se a presença de derivados fenólicos, especialmente, flavonoides como as isoflavonas e de derivados de catequina. O conteúdo de derivados fenólicos totais variou de 100-320 mg de equivalente em catequina/g amostra e de 90-280 mg de equivalente em ácido gálico/ g amostra, já o de isoflavonoides de 6,24-11,15 mg de equivalente em biochanina A/g amostra e o de flavonoides totais de 1,20-4,55 mg de equivalente em quercetina/g amostra. As CE50 para o método DPPH variaram de 5,99-31,90 μg/mL. Os valores da atividade antioxidante equivalente ao Trolox (TEAC) para as amostras foram de 0,161-0,693. Foi encontrada forte correlação entre atividade antioxidante por DPPH e o conteúdo de derivados fenólicos (Pearson > 0,9) e entre TEAC e o teor de flavonoides expressos em quercetina (Pearson > 0,83). A fração em hexano e em clorofórmio apresentaram CE50 de 40,5 μg/mL e 136,2 μg/mL, respectivamente, no ensaio de quantificação de substâncias reativas ao ácido tiobarbitúrico (SRAT). As amostras mais ativas no ensaio antiplasmodial (Teste LDH) foram as frações em hexano e em clorofórmio com 31% de inibição do crescimento de P. falciparum. Já no ensaio de inibição da polimerização da ferriprotoporfirina (FBIT) as CE50 variaram de 0,41-1,12 mg/mL sendo as frações em hexano, clorofórmio e em acetato de etila ativas, juntamente com o extrato lipofílico. In vivo, estas amostras a 200 mg/kg/dia foram ativas no teste de Peters com inibições da parasitemia de 39-75% no sétimo dia após a infeccção. Os resultados indicaram que A. nitida apresenta perfil químico predominante em isoflavonas, corroborado pela quantificação de isoflavonoides, dessa forma ratifica-se o papel das isoflavonas como possíveis marcadores quimiossistemáticos do gênero Andira, além de responsáveis, em parte, pela atividade antimalárica das espécies estudadas até o presente momento. Além disso, as amostras provenientes dos galhos de A. nitida podem ser fontes de substâncias bioativas com pronunciada atividade antioxidante, além de interessante atividade antimalárica. / The Andira species (Fabaceae), popularly known as "Angelins" stand out for popular use as febrifugue, vermifuge and antimalarial. Chemically they are characterized by the presence of phenolic derivatives such as isoflavones. However, despite evidence of antimalarial activity of the genus, there is a lack about chemical and biological studies of Andira nitida. So the present study aimed to establish the chemical profile and assess the biological potential of A. nitida, to find a possible option for new therapeutic targets for the malaria treatment. The chemical profile was established by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), after analysis of the chromatograms; they showed the predominant presence of phenolic derivatives, especially flavonoids such as isoflavones and catechin derivatives. The contents of phenolic derivatives ranged from 100 to 320 mg catechin equivalent/g sample and from 90 to 280 mg gallic acid equivalent/g sample. The isoflavonoids content ranged from 6.24 to 11.15 mg equivalent biochanin A/g sample and flavonoids content ranged from 1.20 to 4.55 mg quercetin equivalent/g sample. The EC50 for DPPH ranged from 5.99-31.90 μg/mL.Trolox equivalent antioxidant activity (TEAC) values for the samples were 0.161 to 0.693. Strong correlation was found between oxidant activity by DPPH and content of phenolic derivatives (Pearson > 0.9) and between TEAC and the flavonoids content expressed in quercetin (Pearson > 0.83). The fraction in hexane and in chloroform showed EC50 of 40.5 μg/mL and 136.2 μg/mL, respectively; in the quantification of thiobarbituric acid reactive substances assay (TBARS). The more active samples in antiplasmodial assay (LDH testing) were the fractions in hexane and in chloroform with 31% inhibition of P. falciparum growth. In the ferriprotoporphyrin polymerization inhibition assay (FBIT) the EC50 ranging from 0.41 to 1.12 mg/ml and the fractions in hexane, in chloroform and in ethyl acetate were actives along with the lipophilic extract. In vivo, these samples at 200 mg/kg/day (Peters testing) showed parasitaemia inhibitions of 39-75 % in day 7 after infection. The results indicated that A. nitida presents chemical profile composed of isoflavones, corroborated by quantification of isoflavones, and thus confirms the role of isoflavones as potential chemosystematic markers of Andira genus. Futhermore, the samples from A. nitida can be a source of bioactive substances with pronounced antioxidant activity, as well as interesting antimalarial activity thus can be an alternative for future therapeutic applications.
7

Étude métabolomique et valorisation pharmacologique et biotechnologique d'éspèces du genre Psiadia endémiques de la Réunion et de l'ile Maurice / Metabolomic study and pharmacological and biotechnological valorization of species of the Psiadia genus endemic to Reunion and Mauritius

Mahadeo, Keshika 28 February 2018 (has links)
Les travaux de thèse présentés dans ce manuscrit portent sur l’étude chimique de plantes du genre Psiadia. Trois axes de recherche ont été menés parallèlement à savoir (1) une étude chimiotaxonomique à partir de 11 espèces du genre Psiadia endémiques de La Réunion, (2) un criblage biologique réalisé sur 16 espèces du genre Psiadia dont 11 endémiques de La Réunion et 5 endémiques de Maurice et (3) une étude phytochimique ciblée sur l’espèce Psiadia arguta endémique de Maurice. Le premier axe comportant l'étude chimiotaxonomique menée par une approche métabolomique avait pour objectif d'identifier des marqueurs chimiotaxonomiques. Cette étude a été effectuée à partir des analyses CG-SM et CG-DIF des composés volatils et des analyses RMN 1H des composés non volatils de 11 espèces endémiques de La Réunion récoltées sur différents lieux géographiques et au cours des saisons estivale et hivernale. Une analyse intra-espèce a permis d'étudier la variabilité saisonnière et/ou géographique de la composition chimique de chaque espèce. Une analyse inter-espèces a conduit à deux classifications différentes des 11 espèces selon leur composition en métabolites volatils et non volatils. Le deuxième axe avait pour objectif d'identifier parmi 11 espèces du genre Psiadia endémiques de La Réunion et 5 espèces endémiques de Maurice, les espèces présentant une ou des activités biologiques prometteuses. Les cibles biologiques choisies ont été le parasite Plasmodium falciparum responsable du paludisme, la lignée cellulaire humaine cancéreuse HeLa responsable du cancer du col de l'utérus et l'enzyme HRP (Horseradish peroxydase) intervenant dans la réponse inflammatoire. À l'issue de ce criblage, 5 espèces se sont révélées prometteuses : les espèces réunionnaises P. amygdalina et P. anchusifolia et les espèces mauriciennes P. arguta et P. lithospermifolia pour l'activité antiplasmodiale, ainsi que l'espèce réunionnaise P. dentata pour les trois activités testées. Le troisième axe consacré à une étude phytochimique de P. arguta réalisée par un fractionnement bioguidé de l'extrait brut a conduit à l'isolement et à l'identification de 16 terpénoïdes : 2 triterpènes et 14 diterpènes de structure labdane dont 4 sont de structure nouvelle. Cinq diterpènes se sont révélés particulièrement actifs contre le parasite P. falciparum : l'acétate de labda-13(E)-en-8α-ol-15-yle, l'acétate de labdan-8α-ol-15-yle, le 13-épi-sclaréol, le labda-13(E)-ène-8α,15-diol et le (8R,13S)-labdane-8,15-diol. Par ailleurs, une étude métabolomique menée par RMN 1H sur des plantules de P. arguta cultivées in vitro et acclimatées a permis l'étude des facteurs influençant la production de ces composés bioactifs. / The present work describes the chemical composition of the plant genus Psiadia and focuses on three research topics: (1) a chemotaxonomic study of 11 species endemic to Reunion island, (2) a biological screening of 16 Psiadia species among which 11 are endemic to Reunion and 5 are endemic to Mauritius and (3) a phytochemical investigation of Psiadia arguta, endemic to Mauritius. The aim of the chemotaxonomic study was to identify chemical markers by a metabolomic approach using GC-MS and GC-FID for volatiles compounds and 1H NMR for non-volatiles compounds. The 11 studied species were harvested in different locations and seasons in order to analyze the seasonal or geographical variability of the chemical profile of each species. This study led to two classifications of the 11 species in terms of the composition of volatiles and non-volatiles compounds. The objective of the second research topic was to identify within 11 species endemic to Reunion island and 5 species endemic to Mauritius, the most active species for the biological activities tested. The targeted activities were antiplasmodial against Plasmodium falciparum, anticancer against the human cancer cell lines HeLa and anti-inflammatory through the inhibition of the enzyme HRP (Horseradish Peroxidase). Four species, P. amygdalina and P. anchusifolia, endemic to Reunion, and P. arguta and P. lithospermifolia, endemic to Mauritius, were particularly active against P. falciparum. Besides, P. dentata (endemic to Reunion) displayed interesting antiplasmodial, anticancer and anti-inflammatory activities. The third research topic was devoted to a phytochemical investigation of P. arguta by a bioguided fractionation and led to purification and identification of 16 terpenoids: 2 triterpenes and 4 diterpenes including 4 new compounds. The evaluation of the antiplasmodial activity of all isolated compounds allowed to highlight activities of five diterpenes: labda-13(E)-en-8α-ol-15-yle acetate, labdan-8α-ol-15-yle acetate, 13-epi-sclareol, labda-13(E)-ene-8α,15-diol and (8R,13S)-labdane-8,15-diol. Furthermore, in order to identify factors influencing the production of bioactive compounds, P. arguta has been multiplicated using in vitro culture techniques and micropropagated plants were acclimatized.
8

Atividade antiplasm?dica e toxicol?gica de plantas medicinais usadas popularmente no Brasil : uma abordagem etnobot?nica

Wanderley, Bruno Mattos Silva 15 October 2012 (has links)
Made available in DSpace on 2014-12-17T14:10:27Z (GMT). No. of bitstreams: 1 BrunoMSW_DISSERT.pdf: 2493064 bytes, checksum: 67d2a8f0addf9c48ec5976ed766a8e15 (MD5) Previous issue date: 2012-10-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Malaria is a disease of global distribution, recognized by governments around the world as a serious public health problem, affecting more than 109 countries and territories and endangering more than 3.3 billion people. The economic costs of this disease are also relevant: the African continent itself has malaria-related costs of about $ 12 billion annually. Nowadays, in addition to chloroquine, Plasmodium falciparum is resistant to many drugs used in the treatment of malaria, such as amodiaquine, mefloquine, quinine and sulfadoxine-pyrimethamine; resistance of Plasmodium vivax to treatments, although less studied, is also reported. Nature, in general, is responsible for the production of most known organic substances, and the plant kingdom is responsible for the most of the chemical diversity known and reported in the literature. Most medicinal plants commercialized in Brazil, however, are of exotic origin, which makes the search for endemic medicinal plants, besides a patent necessity, a fascinating subject of academic research and development. This study aimed to: (i) verify the antimalarial activity of ethanolic and hydroalcoholic extracts of Boerhavia paniculata Rich. And acetonic extract of Clethra scabra Pers. in Swiss albino mice infected by Plasmodium berghei NK65, (ii) observe possible combined effects between the course of infection by P. berghei NK65 and administration of these extracts in Swiss albino mice, and (iii) conduct a preliminary study of the acute toxicity of these extracts in Swiss albino mice. All extracts notable pharmacological activities - with parasite infections inhibitions ranging from 22% to 54%.These characteristics suggest that the activities are relevant, although comparatively lower than the activity displayed by the positive control group (always above 90%). The general framework of survival analysis demonstrates an overall reduction in survival times for all groups. Necroscopy has not pointed no change in color, shape, size and/or consistency in the evaluated organs - the only exception was the livers of rats submitted to treatment to hydroalcoholic extracts: these organs have been presented in a slightly congestive aspect with mass increasing roughly 28% higher than the other two groups and a p-value of 0.0365. The 250 mg/Kg ethanolic group has been pointed out by the Dunn s post test, as the only class with simultaneous inequalities (p<0.05) between positive and negative control groups. The extracts, notably ethanol extract, have, in fact, a vestigial antimalarial activity, although well below from the ones perceived to chloroquine-treated groups; nevertheless, the survival times of the animals fed with the extracts do not rise by presence of such therapy. Both the toxicopharmacological studies of the synergism between the clinical course of malaria and administration of extracts and the isolated evaluation of toxicity allow us to affirm the absence of toxicity of the extracts at the level of CNS and ANS, as well as their non-influence on food and water consumption patterns, until dosages of 500 mg/Kg. Necroscopic analysis leads us to deduct a possible hepatotoxic effect of hydroalcoholic extract at dosages of 500 mg/Kg, and an innocuous tissue activity of the ethanol extract, in the same dosage. We propose a continuation of the studies of these extracts, with protocol modifications capable of addressing more clearly and objectively their pharmacological and toxicological aspects / A mal?ria ? uma doen?a de distribui??o global, reconhecida por governos de todo o mundo como grave problema de sa?de p?blica, ocorrendo em mais de 109 pa?ses e territ?rios e pondo em risco mais de 3,3 bilh?es de pessoas. Os custos econ?micos da doen?a s?o tamb?m relevantes: apenas o continente africano tem um ?nus de cerca de US$12 bilh?es anuais. Hodiernamente, al?m da cloroquina, o Plasmodium falciparum apresenta resist?ncia aos diversos medicamentos usados na rotina, como amodiaquina, mefloquina, quinina e sulfadoxina-pirimetamina; a resist?ncia de Plasmodium vivax, apesar de menos estudada, tamb?m ? relatada. A natureza, de um modo geral, ? a respons?vel pela produ??o da maioria das subst?ncias org?nicas conhecidas, sendo o reino vegetal respons?vel pela maior parcela da diversidade qu?mica conhecida e registrada na literatura. A maioria das plantas medicinais comercializadas no Brasil, contudo, ? de origem ex?tica, o que torna a busca por plantas medicinais end?micas, al?m de uma patente necessidade, um fascinante assunto de pesquisa acad?mica e de desenvolvimento. Este trabalho teve por objetivo: (i) verificar a atividade antimal?rica dos extratos etan?lico e hidroalco?lico de Boerhavia paniculata Rich. e acet?nico de Clethra scabra Pers. em camundongos albinos Swiss infectados por Plasmodium berghei NK65; (ii) observar poss?veis efeitos combinados entre o curso da infec??o por P. berghei NK65 e a administra??o destes extratos em camundongos albinos Swiss; e (iii) realizar um estudo da toxicidade aguda destes extratos em camundongos albinos Swiss. Notam-se, em todos os extratos, atividades farmacol?gicas not?rias com inibi??es da parasitemia variando de 22% a 54% - caracter?sticas estas que sugerem atividades relevantes, apesar de comparativamente inferior ? atividade apresentada pelo grupo controle positivo (sempre superior a 90%). O quadro geral da an?lise de sobreviv?ncia demonstra uma redu??o global dos tempos de sobrevida para todos os grupos testados. A necroscopia n?o apontou, em um quadro geral, qualquer altera??o de cor, forma, tamanho e/ou consist?ncia nos ?rg?os avaliados nos estudos a ?nica exce??o recaiu sobre os f?gados dos animais submetidos ao extrato hidroalco?lico: estes se apresentaram sob um aspecto levemente congestivo, com aumento de massa cerca de 28% superior aos outros dois grupos e um p-valor de 0,0365. O grupo etan?lico 250 mg/Kg foi apontado, pelo p?s-teste de Dunn, como a ?nica classe com desigualdades simult?neas (p< 0,05) entre os grupos controles positivo e negativo. Os extratos analisados, notadamente o extrato etan?lico, apresentam, de fato, uma atividade antiplasm?dica resquicial, embora muito abaixo da percebida para grupos tratados com cloroquina; n?o obstante, os tempos de sobrevida dos animais submetidos aos tratamentos com os extratos n?o se elevam mediante a presen?a de tal terap?utica. Tanto o estudo t?xico-farmacol?gico do sinergismo entre a evolu??o cl?nica da mal?ria e a administra??o dos extratos quanto a avalia??o isolada de toxicidade nos permitem afirmar a aus?ncia de toxicidade dos extratos em n?vel de SNC e SNA, bem como a n?o influ?ncia destes nos padr?es de consumo h?drico e alimentar, at? as doses de 500 mg/Kg. A an?lise necrosc?pica nos leva ? dedu??o de um poss?vel efeito hepatot?xico do extrato hidroalco?lico, em doses de 500 mg/Kg, e uma atividade tecidual in?cua do extrato etan?lico, em mesma dosagem. Propomos uma continua??o dos estudos destes extratos, com modifica??es protocolares capazes de abordar, de forma mais clara e objetiva, seus aspectos farmacol?gicos e toxicol?gicos
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Avaliação da atividade antimalárica de análogos de 4-aminoquinolinas e 6-mercaptopurinas em modelo murino

Soares, Roberta Reis 20 February 2013 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-02T11:30:44Z No. of bitstreams: 1 robertareissoares.pdf: 1821120 bytes, checksum: 37f4636d8bd6ef3623072173760d6105 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-12T15:51:49Z (GMT) No. of bitstreams: 1 robertareissoares.pdf: 1821120 bytes, checksum: 37f4636d8bd6ef3623072173760d6105 (MD5) / Made available in DSpace on 2017-05-12T15:51:49Z (GMT). No. of bitstreams: 1 robertareissoares.pdf: 1821120 bytes, checksum: 37f4636d8bd6ef3623072173760d6105 (MD5) Previous issue date: 2013-02-20 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A malária permanece ao longo dos anos como emergência global em saúde pública. São aproximadamente 87 milhões de casos e 106.820 mortes ocorridas anualmente no mundo. As principais estratégias atuais no controle da doença se baseiam no diagnóstico precoce e tratamento oportuno dos casos, devendo ser considerada a resistência dos parasitos a praticamente todos os fármacos atualmente em uso, o que torna urgente a busca por novos antimaláricos. Neste contexto, análogos de 4-aminoquinolinas e 6-mercaptopurinas contendo 1,2,3-triazol ou esteroide foram sintetizados e tiveram sua atividade antimalárica investigada utilizando o teste supressivo de Peters em modelo murino de infecção por Plasmodium berghei NK65. Dentre os 11 análogos avaliados, 5 exibiram atividade antimalárica significativa, alcançando percentuais de supressão de até 81% em relação ao controle não tratado. Além da atividade antimalárica, um composto promissor não pode apresentar efeitos indesejáveis às células do hospedeiro, sendo assim foram avaliadas a citotoxicidade e atividade hemolítica dos análogos. A maioria dos compostos foram considerados seguros às células do hospedeiro mesmo nas maiores concentrações avaliadas. Portanto, estes análogos merecem ser objeto de futuras investigações visando compor novos antimaláricos. / Malaria remains over the years as a global public health emergency. There are approximately 87 million cases and 106.820 deaths worldwide each year. The main current strategies to control the disease are based on early diagnosis and appropriate treatment cases and should be considered the resistance of parasites to almost all drugs currently in use, which makes urgent the search for new antimalarials. In this context, analogs of 4-aminoquinolines and 6-mercaptopurines containing 1,2,3-triazole or steroid were synthesized and investigated for their antimalarial activity using the 4-day suppressive test described by Peters in a murine model of infection by Plasmodium berghei NK65. Among the 11 analogues evaluated, 5 exhibited significant antimalarial activity, reaching percentages of suppression up to 81% compared to untreated control. Besides antimalarial activity, a promising compound cannot have undesirable effects on host cells, thus was evaluated the cytotoxicity and hemolytic activity of analogs. Most compounds were considered safe to host cells even at the highest concentrations evaluated. So, this analogs deserve to be object of future investigations aiming compose new antimalarials.
10

Biodiversité des invertébrés marins : de l'isolement à la modélisation moléculaire de métabolites secondaires pour la découverte de nouveaux candidats médicaments / Biodiversity of marine invertebrates : from isolation to molecular modeling of secondary metabolites for the discovery of new drug candidates.

Campos, Pierre-Éric 08 February 2017 (has links)
Les travaux de thèse exposés dans ce manuscrit portent sur l'étude chimique de quatre éponges marines collectées à Madagascar : Monanchora unguiculata, Amphimedon sp., Aulospongus gardineri et Biemna laboutei. Pour les trois premières, l'extraction, l'isolement et l'identification des métabolites secondaires par différentes techniques chromatographiques (CLMP, CLHP…) et spectroscopiques (UV-visible, SMHR, RMN 1D et 2D…) ont été envisagés. Quinze métabolites secondaires de type alcaloïdes guanidiniques, dérivés de la bromotyrosine, N-acyléthanolamines et polyynes, ont été isolés de ces éponges. Huit sont de structures nouvelles. La valorisation des molécules isolées a ensuite été envisagée via l'évaluation de leurs activités biologiques. Deux d'entres elles, la fromiamycaline (M70) et la ptilomycaline F (MU7) ont montré une excellente activité antipaludique et quatre, la fromiamycaline (M70) et les ptilomycalines E (MU6), G (MU8) et H (MU9) une cytotoxicité sur cellules KB prometteuse. L'étude de la dernière éponge, Biemna laboutei, portait sur des molécules précédemment isolées au sein du LCSNSA. Les travaux entrepris comprenaient une vérification des configurations relatives de neuf alcaloïdes guanidiniques déterminées par RMN grâce à la probabilité DP4+. Les configurations relatives déterminées par RMN de sept des molécules ont ainsi pu être confirmées et trois d'entre elles, les nétamines G (E8), P (E17) et R (E19) ont fait l'objet d'une étude plus approfondie par modélisation moléculaire afin de déterminer leur configuration absolue par comparaison de leur spectre de Dichroïsme Circulaire Électronique expérimental avec un spectre calculé. / The work described in this manuscript concerns the chemical study of four sponges from Madagascar: Monanchora unguiculata, Amphimedon sp., Aulospongus gardineri and Biemna laboutei. For the first three sponges, the study was devoted to the extraction, isolation and identification of secondary metabolites by various chromatographic (MPLC, HPLC…) and spectroscopic (UV, HRMS, 1D and 2D NMR…) techniques. Fitfteen secondary metabolites including guanidine alkaloids, bromotyrosin derivated, N-acylethanolamines and polyynes were isolated from these sponges. Eight are new molecules. The biological activities of the isolated compounds were then evaluated. Two of them, fromiamycalin (M70) and ptilomycalin F (MU7) showed a very good antimalarial activity and four of them, fromiamycalin (M70) and ptilomycalins E (MU6), G (MU8) and H (MU9) a promising cytotoxicity against KB cells. The study of the last sponge, Biemna laboutei, was performed on molecules already isolated in the LCSNSA. This work included the determination of the relative configuration of nine guanidine alkaloids by using the DP4+ probability. The relative configuration of seven molecules was confirmed. Three of them, netamines G (E8), P (E17) and R (E19) were selected for a study by molecular modeling to determine their absolute configuration by comparison of their experimental Electronic Circular Dichroism spectrum with a calculated spectrum.

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