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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

Investigating the mechanism of action of potato extract against Helicobacter pylori

Adeyemi, Temitope January 2016 (has links)
Helicobacter pylori is a Gram-negative bacterium that is the major cause of many upper gastrointestinal diseases such as gastritis and peptic ulcer disease. It has the unique ability of colonising the human gastric mucosa. Failure in complete eradication of H. pylori in infected patients, mainly due to antibiotic resistance, has necessitated the development of better therapeutics, especially from natural sources. In this study, extract of Maris piper potatoes were obtained and evaluated for antibacterial activity against H. pylori in vitro. Antibacterial activity was carried out against antibiotic-sensitive and clinical antibiotic-resistant H. pylori strains, as well as a range of Gram-negative bacteria including Helicobacter and Campylobacter species, using the viable count method. Result of the antibacterial assays indicated that potato extract is bactericidal against H. pylori lab strain as well as clinical antibiotic-resistant strains, with minimum inhibitory concentration at 15.6 mg/ml. Potato extract also showed minimal antibacterial activity against other Gram- negative bacteria tested, with minimum inhibitory concentration at 250 mg/ml. The effect of the extract on the morphology of H. pylori was also observed by transmission electron microscopy (TEM). TEM analysis of potato extract-treated H. pylori cells showed disruption of the morphology of H. pylori, characterized by separation of the outer membrane from the inner membrane and loss of cell shape. Potato extract also caused hyperpolarisation of H. pylori plasma membrane; however it is unclear whether the membrane active pumping activity is affected. Mutants of H. pylori that are resistant to potato extract were generated as a means to identify the target of potato extract within the H. pylori genome. Genome sequence analysis led to the discovery of a hypothetical protein, encoded by HP0603 gene, which may be involved in inducing resistance to potato extract. The results obtained in this study provide great insights into the anti-H. pylori activity of potato extract. Overall, this study suggests the potential use of potato extract as a source of anti-H. pylori agents; and stimulates further studies into identifying its mechanism of action.
2

Control of Foodborne Pathogenic Bacteria Using Natural Plant Antimicrobials

Reyna-Granados, Javier Rolando January 2012 (has links)
Foodborne pathogens are a threat to public health worldwide. Because many consumers prefer natural compounds to synthetic additives, research on safe plant-derived compounds with antimicrobial activity against foodborne pathogens is vital. The aim of this investigation was to evaluate the antimicrobial activities of plant essential oils (oregano, cinnamon, lemongrass), their active components (carvacrol, trans-cinnamaldehyde, citral) and plant-extracts such as green tea, apple skin extract, black and decaffeinated black tea, grapes seed and pomace extracts against foodborne bacteria. Salmonella enterica serotype Typhimurium DT104, and serotype Newport, were selected conducting an antibiotic screening on 23 Salmonella isolates using seven antibiotics to determine antibiotic resistance. Listeria monocytogenes (strain 101M; beef and pork sausage isolate; resistant to antimicrobials in past investigations) was included to represent gram-positive bacteria. Escherichia coli O157:H7 virulent isolates (932- apple juice isolate; ATCC 35150- human isolate; F4637- sprouts isolate; used as a cocktail) were selected after conducting a Multiplex PCR over nine E. coli O157:H7 isolates to detect shiga-toxin 1 and 2 genes. All antimicrobials were evaluated in vitro in phosphate buffered saline. In general, all pathogens were more susceptible to essential oils and their active components, than powder extracts. The most active antimicrobials from each category were directly applied on foods. The activity of oregano oil (0.5%) and green tea (3%) was evaluated against S. Typhimurium on chicken and S. Newport on tomatoes and sprouts, and the results showed that oregano oil was more effective. In addition, baby spinach leaf samples inoculated with green fluorescent protein labeled S. Newport were examined under confocal scanning laser microscope before and after antimicrobial treatments. Antimicrobial experiments against L. monocytogenes on sprouts, ham and bologna, carvacrol at 0.5% and grape seed extract at 3% were used and carvacrol showed better activity. Antimicrobial activity against E. coli O157:H7 was tested on romaine lettuce, spinach and ground beef using oregano oil at 0.5% and green tea at 3%. Both compounds were effective showing no recovery of E. coli O157:H7 from lettuce and spinach; however, was not reduced in ground beef. Antimicrobial plant compounds have the potential for reducing foodborne pathogenic bacteria on/in various foods.
3

Avalia??o da efici?ncia do extrato de ra?z Dahlstedti pentaphylla (Leguminosae, Papilionoidae, Millettiedae) sobre Boophilus microplus (CANESTRINI, 1887) na Regi?o do Vale do Para?ba - S?o Paulo, Brasil / Evaluate the efficiency of root extracts of Dahlstedt pentaphylla (Leguminosae, Papilionoidae, Millettiedae) about Boophilus microplus (Canestrini, 1887) in Para?ba Valley ? S?o Paulo, Brasil

PEREIRA, Jos? Roberto 25 May 2004 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-23T17:23:05Z No. of bitstreams: 1 2004 - Jos? Roberto Pererira.pdf: 1063290 bytes, checksum: ac86f4bd5958ba416f5739fd8e9c3de5 (MD5) / Made available in DSpace on 2017-06-23T17:23:05Z (GMT). No. of bitstreams: 1 2004 - Jos? Roberto Pererira.pdf: 1063290 bytes, checksum: ac86f4bd5958ba416f5739fd8e9c3de5 (MD5) Previous issue date: 2004-05-25 / Laboratory and field trials were performed to evaluate the efficiency of Timb? root extract (Dahlstedtia pentaphylla) (Taub). Burk. (Leguminosae, Papilionoidae, Millettiedae) on samples of Boophilus microplus (Canestrini, 1887) in bovines of the Para?ba Valley region ? S?o Paulo, Brasil. The ?in vitro? trials were carried out using immersion of engorged females, and ?in vivo? on bovines in the field by means of artificial infestation. The standard dilution was made from one part of root powder and three parts of ethanol this was considered the 100% solution. To determine the more efficient solvent to extract rotenone from the root, laboratory trials were conducted on B. microplus engorged females with in three solvents: water, ethanol a.p. and acetone a.p. The laboratory trials permitted the calculation of lethal doses at 90% (LD90) and 50% (LD50) for larvae between seventh and fourtheenth days of application and efficient concentrations at 90% (EC90) and 50% (EC50) on strain local and Mozo with B. microplus engorged females. For the larvae of the local strain (Para?ba Valley Regional Hub) LD50 calculated was 1:31,37 mL and LD90 was 1:85,24 mL. The EC90 for engorged females, of the same strain was of 1:10,19 mL and the EC50 1:34,94 mL. For the engorged females on the hypersersitive strain Mozo the EC90 was 1:23,91 mL and the EC50 1:60,46 mL. The mortality of engorged females in relation to the different kinds of solvents, was analyzed. In the field, the best results (76,10% of control) were obtained three days after application of the product extracted in ethanol, in 1:10, on animals. Then gradually between the seventh and fourteenth days the products lost efficiency, there was no significant difference between treatments and the control group after 21 days. / Foram realizados testes laboratoriais e de campo para avaliar a efici?ncia do extrato de ra?zes da planta Dahlstedtia pentaphylla (Taub.) Burk., (Leguminosae, Papilionoideae, Millettiae) sobre amostras de Boophilus microplus ( Canestrini, 1887 ) de bovinos da regi?o do Vale do Para?ba e da cepa sens?vel Mozo. Os testes foram efetuados ?in vitro?, pela t?cnica de imers?o de tel?ginas e ?in vivo?, sobre bovinos no campo, ap?s infesta??o artificial. As dilui??es foram obtidas a partir da extra??o de roten?ides utilizando?se uma parte de p? das ra?zes da planta para tr?s de etanol, sendo considerada padr?o 100%. Visando determinar o solvente mais eficiente para a extra??o de roten?ides das ra?zes, conduziram-se testes laboratoriais sobre tele?ginas de B. microplus em tr?s solventes: ?gua, etanol p.a e acetona p.a. Os testes laboratoriais permitiram calcular a Dose Letal 90% (DL90) e DL50 para larvas com idade entre sete e 21 dias e a Concentra??o Eficaz 90% (CE90) e CE50 sobre tele?ginas de B. microplus das cepas local e Mozo. Para as larvas da cepa local (Polo Regional do Vale do Para?ba) a DL50 calculada foi de 1: 231,37 mL e DL90 1: 85,24 mL. A CE90 para as tele?ginas, da mesma cepa, foi de 1:10,19 mL e a CE50 1: 34,94 mL. Para tele?ginas da cepa sens?vel Mozo a CE90 foi de 1: 23,91 mL e a CE50, 1: 60,46 mL. Analisou-se tamb?m a mortalidade das tele?ginas frente aos diferentes solventes. No campo os melhores resultados obtidos (76,10% de controle) foram obtidos tr?s dias ap?s a aplica??o do produto extra?do em etanol, na dilui??o 1: 10, sobre os animais. A partir da? gradualmente nos dias sete e quatorze os produtos foram perdendo efici?ncia, n?o apresentando mais diferen?a significativa entre os tratamentos e o grupo controle no dia +21.
4

Avaliação dos extratos vegetais de clusia fluminensis planch & triana na neutralização de atividades biológicas provocadas pelo veneno de Bothrops jararaca

Oliveira, Eduardo Coriolano de 03 April 2017 (has links)
Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-04-03T16:56:41Z No. of bitstreams: 1 Oliveira, Eduardo Coriolano de [Dissertação, 2011].pdf: 1135569 bytes, checksum: 8920e224ba454e60a5daa5d299a3e9bb (MD5) / Made available in DSpace on 2017-04-03T16:56:41Z (GMT). No. of bitstreams: 1 Oliveira, Eduardo Coriolano de [Dissertação, 2011].pdf: 1135569 bytes, checksum: 8920e224ba454e60a5daa5d299a3e9bb (MD5) / O envenenamento ofídico, dentre os acidentes com animais peçonhentos é o mais importante deles, pela sua frequência e gravidade. No Brasil, as serpentes do gênero Bothrops são responsáveis por 90 % dos acidentes ofídicos. Os extratos vegetais apresentam uma diversidade de moléculas com diversas ações farmacológicas. As espécies de Clusia são de grande interesse paisagístico, porém duas espécies deste gênero, C. torresii Standl. e C. palmana Standl. apresentam propriedades antiofídicas contra o veneno de B. asper. O objetivo do nosso trabalho foi avaliar as propriedades antiofídicas da espécie Clusia fluminensis Planch & Triana, utilizando diferentes partes vegetais e solventes de diferentes polaridades para o preparo dos extratos, assim como uma benzofenona isolada do extrato hexânico da flor, frente atividades biológicas do veneno de B. jararaca. Ensaios in vitro mostraram que os extratos hexânicos e metanólicos das folhas e frutos, na proporção de 1:50 (veneno:extrato) foram capazes de inibir 100 % a atividade proteolítica do veneno de B. jararaca (9 μg/mL), usando-se azocaseína como substrato; com exceção do extrato hexânico do caule e da benzofenona que inibiram cerca de 50 %. Na atividade hemolítica do veneno de B. jararaca (88 μg/mL), a inibição foi de 40 %, nas proporções de 1:10 e 1:20. Por outro lado, os extratos nestas mesmas proporções não foram capazes de neutralizar a coagulação do plasma induzida pelo veneno de B. jararaca (22 μg/mL), de forma significativa. Em ensaios in vivo (atividade hemorrágica) apenas o extrato acetônico do fruto, na proporção de 1:20, foi capaz de reverter totalmente a hemorragia causada pelo veneno de B. jararaca (16,7 μg/g). Sendo assim, nossos resultados mostram que a planta C. fluminensis pode ser uma fonte de moléculas com propriedades antiofídicas, especificamente contra o veneno de B. jararaca, e que este efeito neutralizante está diretamente relacionado a parte do vegetal e a polaridade do solvente utilizado na extração, Além disso podemos concluir que a benzofenona não é responsável, isoladamente, pelos resultados obtidos / Snake venom poisoning, among accidents with venomous animals is the most important of them, by their frequency and severity. In Brazil, Bothrops are responsible for 90 % of snake bites. The plant extracts have a variety of molecules with several pharmacological actions. Clusia species are of great landscape interest, but two species of this genus, C. torresii Standl. and C. palmana Standl. have properties against snake venom B. asper. The aim of our study was to evaluate the antivenom properties the species Clusia fluminensis Triana & Planch, using different plant parts and solvents of different polarities for the preparation of extracts, as well as a benzophenone isolated from the hexane extract of the flower, against biological activity of the venom of B. jararaca. In vitro assays showed that the hexane and methanolic extracts of leaves and fruits at a ratio of 1:50 (venom: extract) were able to inhibit 100 % proteolytic activity of the venom of B.jararaca (9μg/mL), using azocaseíne as substrate, with the exception of hexanic extract from stem and benzophenone which inhibited about 50 %. In the hemolytic activity of the venom of B. jararaca (88 μg/mL), inhibition was 40 %, the proportions of 1:10 and 1:20. On the other hand, the same proportions in these extracts were not able to neutralize the plasma coagulation induced by the venom of B. jararaca (22 μg/mL) significantly. In vivo assays (hemorrhagic activity) only the acetone extract of the fruit was able to totally reverse bleeding caused by the venom of B. jararaca (16,7 μg/g). Thus, our results show that the plant C. fluminensis can be a source of molecules with neutralizing properties of snake venom, specifically against the venom of B. jararaca, and that the neutralizing effect is directly related to part of the plant and the polarity of the solvent used in extraction, we can also conclude that benzophenone is not responsible alone for the results
5

Ação antimicrobiana in vitro de Psidium guajava L. contra Staphylococcus aureus isolados de leite mastítico / In vitro antimicrobial activity of Psidium guajava L. against Staphylococcus aureus isolated from mastitic milk.

Menezes, Juliana da Silva 04 February 2013 (has links)
Made available in DSpace on 2016-05-02T13:55:35Z (GMT). No. of bitstreams: 1 Juliana da Silva MenezesDissertacaoPt2.pdf: 1449580 bytes, checksum: a75c6c34c790ed22db757094de03b7a2 (MD5) Previous issue date: 2013-02-04 / Coordenacao de Aperfeicoamento de Pessoal de Nïvel Superior / Mastitis is a disease that affects dairy cattle, an intramammary infection. Staphylococcus aureus are the major mastitis causing bacteria and the milk can be contaminated by the contact with infected teats. For treatment, due to the indiscriminate use of antimicrobials drugs commercialized, the appearing of multi-resistant strains is notorious. An alternative to the antimicrobial resistance problem is the use of plant extracts like Psidium guajava L. The objective of this study was to evaluate, in vitro, the microbial sensibility profile of Staphylococcus aureus isolated from milk samples of cows infected with mastitis, against antimicrobial agents and hydroalcoholic leaf of Psidium guajava L. Plants were harvested in three rural properties located in the municipality of Alfenas/MG region. Sampling animals was not probabilistic. Milk samples were cultured for presence of Staphylococcus sp. Additionally, the isolated bacteria were identified as Staphylococcus aureus and subjected to many tests to check the antimicrobial sensibility. The hydroalcoholic extract of Psidium guajava L. was prepared and antimicrobial tests were performed by the technician in wells. Contamination by Staphylococcus aureus was confirmed in 55% of the analyzed samples. The most effective antibiotics were clindamycin, erythromycin and rifampin. Penicillin G was the antimicrobial that showed the lower levels of sensibility. The hydroalcoholic extract of the leaf of Psidium guajava L. showed antimicrobial activity against all strains of isolated Staphylococcus aureus by inhibiting microbial growth in all tested concentrations. Therefore the use of this plant extract can be an alternative method to combat the increase incidence of microorganisms resistant to antimicrobial drugs sold, besides a potential field of study. / A mastite é a infecção intramamária que acomete o gado leiteiro bovino, causada mais frequentemente pela bactéria Staphylococcus aureus. O leite pode ser contaminado pelo contato direto com tetos infectados. Devido ao uso indiscriminado de antimicrobianos utilizados para o tratamento, é notório o aparecimento de micro-organismos resistentes. Uma alternativa pode ser o uso de extratos vegetais, a exemplo Psidium guajava L.. O objetivo deste trabalho foi avaliar o perfil de sensibilidade microbiana in vitro de isolados de Staphylococcus aureus provenientes de leite mastítico contra antimicrobianos e extrato hidroalcoólico da folha de Psidium guajava L.. A colheita foi realizada em três propriedades rurais da região da cidade de Alfenas, MG. A amostragem dos animais foi não probabilística. As amostras de leite foram processadas e inoculadas em meios de cultura seletivos para verificar a presença de Staphylococcus sp. Os isolados foram identificados quanto à espécie Staphylococcus aureus e submetidos a diferentes testes para verificar a sensibilidade aos antimicrobianos. Foi preparado o extrato hidroalcoólico das folhas e os testes antimicrobianos realizados pela técnica de poços. Foi confirmada a contaminação por Staphylococcus aureus em 55% das amostras. Os antibióticos de maior ação foram clindamicina, eritromicina e rifampicina. Penicilina G foi o antimicrobiano que apresentou menores índices de sensibilidade. O extrato da folha apresentou atividade antimicrobiana contra todos os isolados, inibindo o crescimento em todas as concentrações testadas. Portanto, a utilização deste extrato vegetal pode ser uma alternativa à crescente resistência microbiana aos antimicrobianos comercializados, sendo um potencial campo de estudos.
6

Investigation of G1 Arrest Mechanisms Induced by Sanguisorba officinalis Extracts in B16F10 Cells / Sanguisorba officinalis の抽出物がB16F10細胞に誘導するG1 arrest の誘導機構の解析

Tan, Yi-Hsun 25 November 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(生命科学) / 甲第22136号 / 生博第423号 / 新制||生||55(附属図書館) / 京都大学大学院生命科学研究科高次生命科学専攻 / (主査)教授 垣塚 彰, 教授 原田 浩, 教授 豊島 文子 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM
7

Copigmentation and Pyranoanthocyanin Formation as Means to Enhance and StabilizeAnthocyanins and Their Colors

Zhu, Xiaoyi January 2020 (has links)
No description available.
8

Plant Extract Sensitised Nanoporous TiO2 Thin Film Photoelectrochemical Cells

Hedbor, Sigrid, Klar, Linnéa January 2005 (has links)
<p>För att undersöka skillnad i prestationsförmåga mellan celler sensiterade med växtextraktsbaserad färg, och celler sensiterademed ruteniumkomplex-baserad färg, samt huruvida presskraften påverkar en cells prestationsförmåga, tillverkades icke-slutna fotoelektrokemiska färg-sensiterade solceller med tunnfilmsfotoelektroder av pressad, nanoporös titandioxid.</p><p>Cellerna pressades med tre olika presskrafter och sensiterades med växtextraktsfärg från rödkål, rödbeta, viol och henna, samt en ruteniumkomplex-baserad färg som fick utgöra kontrollbetingelse. För varje cell uppmättes IPCE- och iV-värde och motsvarande fyllnadsgrad (fill factor) och dessa jämfördes.</p><p>Ingen signifikant skillnad kunde fastställas mellan celler pressade med olika presstryck. Bland cellerna sensiterade med växtextraktbaserad färg presterade rödbeta bäst. Cellen med högst effektivitet hade fyllnadsgraden 70%. Emellertid uppvisade de växtfärgade cellerna genomgående sämre effektivitet än de rutenium-sensiterade och fotoströmmarna var mycket låga. IPCE-värdena var allmännt låga: den bäst presterande cellen hade ett IPCE-värde på något över 0,06 i våglängdsintervallet 440-470 nm. En förklaring till detta är de övriga ämnen som förutom pigment återfinns i de växtbaserade färgerna. Dessa hindrar pigmentmättnad och förhindrar att växtfärgen når ruteniumfärgens intensitet. En annan anledning består i svårigheten att passa ihop energinivåerna i cellens elektrolyt-halvledarsystem med energinivåerna hos pigmentet i växtfärgen.</p> / <p>Non-sealed photoelectrochemical dye sensitised solar cells (DSSC) with pressed nanoporous TiO2 thin film photoelectrodes were manufactured for the purposes of finding out whether plant extractbased dye sensitised cells can perform as well as ruthenium complex-based dye sensitised cells and whether the pressing force affects the cell performance.</p><p>The cells were pressed with three different pressing forces and sensitised with plant extracts from red cabbage, beetroot, violet and henna, as well as with a ruthenium complex-based dye for comparison. The IPCE and iV values and the corresponding fill factors of the cells were evaluated and compared.</p><p>No significant difference between the cells pressed with different pressing forces could be established. Among the plant extract-based dye sensitised cells the ones sensitised with beetroot extract performed best. The cell that achieved the highest efficiency had a fill factor of 70%. Compared to the ruthenium-sensitised cells the overall performance of the plant dye sensitised cells were very poor and the produced photocurrents very low. The IPCE values were generally low: one of the best-performing cells had an IPCE value of slightly over 0.06 in the 440-470 nm wavelength ranges. One reason for this is that it is difficult to obtain a plant extract dye as intense and deep in colour as ruthenium complex-based dyes, since pigment saturation is obstructed by the presence of other chemical compounds in the plant extracts. Another is that it is a delicate and difficult matter to match the energy levels in the electrolyte-semiconductor system with the energy levels of the pigments in the plant extract dye.</p>
9

Plant Extract Sensitised Nanoporous TiO2 Thin Film Photoelectrochemical Cells

Hedbor, Sigrid, Klar, Linnéa January 2005 (has links)
För att undersöka skillnad i prestationsförmåga mellan celler sensiterade med växtextraktsbaserad färg, och celler sensiterademed ruteniumkomplex-baserad färg, samt huruvida presskraften påverkar en cells prestationsförmåga, tillverkades icke-slutna fotoelektrokemiska färg-sensiterade solceller med tunnfilmsfotoelektroder av pressad, nanoporös titandioxid. Cellerna pressades med tre olika presskrafter och sensiterades med växtextraktsfärg från rödkål, rödbeta, viol och henna, samt en ruteniumkomplex-baserad färg som fick utgöra kontrollbetingelse. För varje cell uppmättes IPCE- och iV-värde och motsvarande fyllnadsgrad (fill factor) och dessa jämfördes. Ingen signifikant skillnad kunde fastställas mellan celler pressade med olika presstryck. Bland cellerna sensiterade med växtextraktbaserad färg presterade rödbeta bäst. Cellen med högst effektivitet hade fyllnadsgraden 70%. Emellertid uppvisade de växtfärgade cellerna genomgående sämre effektivitet än de rutenium-sensiterade och fotoströmmarna var mycket låga. IPCE-värdena var allmännt låga: den bäst presterande cellen hade ett IPCE-värde på något över 0,06 i våglängdsintervallet 440-470 nm. En förklaring till detta är de övriga ämnen som förutom pigment återfinns i de växtbaserade färgerna. Dessa hindrar pigmentmättnad och förhindrar att växtfärgen når ruteniumfärgens intensitet. En annan anledning består i svårigheten att passa ihop energinivåerna i cellens elektrolyt-halvledarsystem med energinivåerna hos pigmentet i växtfärgen. / Non-sealed photoelectrochemical dye sensitised solar cells (DSSC) with pressed nanoporous TiO2 thin film photoelectrodes were manufactured for the purposes of finding out whether plant extractbased dye sensitised cells can perform as well as ruthenium complex-based dye sensitised cells and whether the pressing force affects the cell performance. The cells were pressed with three different pressing forces and sensitised with plant extracts from red cabbage, beetroot, violet and henna, as well as with a ruthenium complex-based dye for comparison. The IPCE and iV values and the corresponding fill factors of the cells were evaluated and compared. No significant difference between the cells pressed with different pressing forces could be established. Among the plant extract-based dye sensitised cells the ones sensitised with beetroot extract performed best. The cell that achieved the highest efficiency had a fill factor of 70%. Compared to the ruthenium-sensitised cells the overall performance of the plant dye sensitised cells were very poor and the produced photocurrents very low. The IPCE values were generally low: one of the best-performing cells had an IPCE value of slightly over 0.06 in the 440-470 nm wavelength ranges. One reason for this is that it is difficult to obtain a plant extract dye as intense and deep in colour as ruthenium complex-based dyes, since pigment saturation is obstructed by the presence of other chemical compounds in the plant extracts. Another is that it is a delicate and difficult matter to match the energy levels in the electrolyte-semiconductor system with the energy levels of the pigments in the plant extract dye.
10

Potencial citotóxico e antimicrobiano de plantas da reserva florestal Adolpho Ducke, Manaus-AM

Carneiro, Ana Lúcia Basílio 15 June 2015 (has links)
Submitted by Alisson Mota (alisson.davidbeckam@gmail.com) on 2015-07-13T18:17:07Z No. of bitstreams: 1 Tese - Ana Lúcia Basílio Carneiro.pdf: 16610047 bytes, checksum: c4cd629d2777cd22001ca4ee47db8b8c (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-15T18:51:06Z (GMT) No. of bitstreams: 1 Tese - Ana Lúcia Basílio Carneiro.pdf: 16610047 bytes, checksum: c4cd629d2777cd22001ca4ee47db8b8c (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-15T18:57:21Z (GMT) No. of bitstreams: 1 Tese - Ana Lúcia Basílio Carneiro.pdf: 16610047 bytes, checksum: c4cd629d2777cd22001ca4ee47db8b8c (MD5) / Made available in DSpace on 2015-07-15T18:57:21Z (GMT). No. of bitstreams: 1 Tese - Ana Lúcia Basílio Carneiro.pdf: 16610047 bytes, checksum: c4cd629d2777cd22001ca4ee47db8b8c (MD5) Previous issue date: 2015-06-15 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Tropical forests are species-rich reserves for the discovery and development of antimicrobial drugs. The aim of this work is to investigate the in vitro antimicrobial potential of Amazon plants found within the National Institute on Amazon Research’s Adolpho Ducke forest reserve, located in Manaus, state of Amazonas, Brazil. 75 methanol, chloroform and water extracts representing 12 plant species were tested for antimicrobial activity towards strains of Mycobacterium smegmatis, Escherichia coli, Streptococcus sanguis, Streptococcus oralis, Staphylococcus aureus and Candida albicans using the gel-diffusion method. Active extracts were further evaluated to establish minimum inhibitory concentrations (MIC) and antimicrobial profiles using bioautography on normal-phase thin-layer chromatography plates. Diclinanona calycina presented extracts with good antimicrobial activity and S. oralis and M. smegmatis were the most sensitive bacteria. D. calycina and Lacmellea gracilis presented extracts with the lowest MIC (48.8 μg/ml). D. calycina methanol and chloroform leaf extracts presented the best overall antimicrobial activity. All test organisms were sensitive to D. calycina branch chloroform extract in the bioautography assay. This is the first evaluation of the biological activity of these plant species and significant in vitro antimicrobial activity was detected in extracts and components from two species, D. calycina and L. gracilis. / O objetivo deste trabalho foi avaliar a atividade citotóxica, antitumoral e antimicrobiana de espécies vegetais amazônicas da Reserva Florestal Adolpho Ducke do Instituto Nacional de Pesquisas da Amazônia (INPA). As espécies vegetais sem estudos anteriores selecionadas e coletadas foram: Diclinanona calycina Benoist, (Annonaceae), Lacmellea gracilis (Mull. Arg.) Markgr. (Apocynaceae), Pleurisanthes parviflora (Ducke) Howard (Icacinaceae), Dilkea johannesii Berb. Rodr. (Passifloraceae), Sterigmapetalum obovatum Kuhlm. (Rhizophoraceae), Elaeoluma nuda (Baehni) Aubrév. (Sapotaceae). Após coleta e extração as amostras foram avaliadas quanto a citotoxicidade frente a Artemia franciscana e em linhagens de células tumorais. O potencial antimicrobiano foi determinado pelo método de difusão em ágar frente a Mycobacterium smegmatis, Escherichia coli, Streptococcus sanguis, S. oralis, Staphylococcus aureus e Candida albicans. Extratos ativos foram conduzidos a avaliação da concentração inibitórioa mínima (CIM) e bioautografia para identificar Rfs de componentes antimicrobianos. Prospecção fitoquímica das espécies promissoras foi realizada para detecção dos principais constituintes químicos. Dos 38 extratos avaliados para toxicidade em A. franciscana, dois apresentaram valores de CL50 inferiores a 100 μg/mL, portanto, tóxicos para essa espécie. A menor CL50 foi do extrato de D. calycina obtido em clorofórmio com valor de 22,9 ± 0,8 μg/mL. No screening para atividade antitumoral, nove extratos representando quatro espécies vegetais foram considerados muito ativos (MA) frente à célula tumoral de sistema nervoso (E. nuda e S. obovatum), cólon (S. obovatum), mama (E.nuda) e leucemia (L. gracilis, P. parviflora, S. obovatum). A maioria dos 75 extratos analisados inibiram o crescimento dos microrganismos teste com halos entre 8 e 40 mm de diâmetro. Extratos de D. calycina demonstraram atividade antimicrobiana com CIM de 48,8 μg/mL frente a S. aureus, S. oralis e S. sanguis e 97,7 μg/mL e 195 μg/mL frente a M. smegmatis. L. gracilis foi ativa apenas contra M. smegmatis (CIM 48,8 μg/mL). A bioautografia confirmou o potencial antimicrobiano de D. calycina e L. gracilis. Todos os microrganismos avaliados por bioautografia foram sensíveis ao extrato de galho de D. calycina obtido em clorofórmio. Na prospecção fitoquímica detectou-se a presença de fenóis, taninos, flavonóides, alcalóides e antraquinonas, em extratos de D. calycina e antraquinonas e cumarinas na espécie L. gracilis. Assim, a seleção permitiu identificar espécies vegetais amazônicas com atividade antimicrobiana e antitumoral in vitro e sugerir as espécies D. calycina, L. gracilis, E. nuda e S. obovatum para apreciação detalhada em outros estudos, pois poderão ter aplicação terapêutica no tratamento de doenças infecciosas e câncer.

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