• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 225
  • 14
  • 8
  • 7
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 270
  • 153
  • 46
  • 36
  • 34
  • 33
  • 32
  • 31
  • 30
  • 23
  • 22
  • 20
  • 18
  • 18
  • 16
  • 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.
81

Fenolinių rūgščių ir fenilpropanoidų nustatymas propolyje / Determination of phenolic acids and phenylpropanoids in propolis

Mažeikaitė, Ingrida 16 June 2008 (has links)
Fenolinės rūgštys ir fenilpropanoidai pasižymi reikšmingu biologiniu aktyvumu ir yra vaistinių žaliavų veiklieji komponentai. Įteisintų tyrimo metodikų vystymas šių junginių nustatymui (kokybiniam ir kiekybiniam žaliavų tyrimui) yra ypač svarbus augalinių vaistinių preparatų efektyvumo, saugumo ir kokybės kontrolei. Iš skirtingų Lietuvos regionų buvo surinkta 18 propolio pavyzdžių. Atlikto darbo tikslas - analitiniais metodais ištirti Lietuvoje surinktų propolio pavyzdžių cheminę sudėtį, bei kiekybiškai ir kokybiškai įvertinti šias fenolines rūgštis ir fenilpropanoidus: chlorogeno rūgštį, cinamono rūgštį, galo rūgštį, ferulo rūgštį, kavos rūgštį, kumaro rūgštį, protokatecho (3,4-dihidroksibenzoinę) rūgštį, rozmarino rūgštį, vaniliną ir vanilino rūgštį. Atlikti tyrimai paprastos ir greitos atvirkštinių fazių efektyviosios skysčių chromatografijos metodikos optimizavimui ir įtiesinimui. Sukurto crhromatografinio metodo judrioji skystoji fazė yra metanolis ir 0,5 procento acto rūgšties tirpalas vandenyje. Esant optimalioms atskyrimo sąlygoms (aprašytoms skyriuje „Tyrimo metodas“), analizė atliekama 27 min., sulaikymo laikas 4,04 min (galo rūgštis), 6,93 min (protokatecho rūgštis), 11,30 min (chlorogeno rūgštis), 12,26 min (vanilinė rūgštis), 12,93 min (kavos rūgštis), 13,80 min (vanilinas), 16,97 min (kumaro rūgštis), 17,95 min (ferulo rūgštis), 22,29 min (rozmarino rūgštis) ir 26,30 min (cinamono rūgštis). Aptikimo riba ir nustatymo riba buvo atitinkamai tarp 0,004–0,021 ir 0,0... [toliau žr. visą tekstą] / The phenolic acids and phenylpropanoids have an important biological activity and are therapeutic agents of crude drugs. Development of validated analysis techniques of these phytotherapeutic agents (fingerprinting and assay procedures) is an important practice for efficacy, safety and quality control of herbal drug preparations. 18 samples of propolis were collected from different districts of Lithuania. The aim of the present work was to study chemical composition of collected samples and estimate analytical capabilities of the evaluation of selected phenolic acids and phenylpropanoids: caffeic acid, chlorogenic acid, cinnamic acid, coumaric acid, ferulic acid, gallic acid, protocatechuic (3,4-dihydroxybenzoic) acid, rosmarinic acid, vanillic acid and vanillin. Optimization and validation procedures of rapid and simple method of reversed phase high performance liquid chromatography were carried out. The mobile phase of the optimized chromatographic method consisted of methanol and 0.5 per cent acetic acid solvent in water. Under the optimal separation conditions (described in Methods), analysis was done in 27 min, with the retention times 4.04 min (gallic acid), 6.93 min (protocatechuic acid), 11.30 min (chlorogenic acid), 12.26 min (vanillic acid), 12.93 min (caffeic acid), 13.80 min (vanillin), 16.97 min (coumaric acid), 17.95 min (ferulic acid), 22.29 min (rosmarinic acid) and 26.30 min (cinnamic acid). The limits of detection and the limits of quantitation were between... [to full text]
82

Propolio neetanolinio ekstrakto technologijos parinkimas ir veikliųjų medžiagų analizė / The selection of propolis non ethanolic extract technology and analysis of active substances

Jasaitytė, Jolanta 18 June 2014 (has links)
Tyrimo tikslas - parinkti neetanolinio propolio ekstrakto technologiją ir atlikti veikliųjų medžiagų analizę. Uždaviniai: nustatyti propolio koncentracijos, ekstrakcijos tirpiklių bei jų koncentracijų, ekstrakcijos laiko, temperatūros, ekstrakcijos metodo įtakas fenolinių junginių išsiskyrimui. Nustatyti propolio ekstrakto antiradikalinį aktyvumą ir flavonoidų kiekį bei efektyviosios skysčių chromatografijos metodu nustatyti propolio ekstrakte esančius cheminius junginius ir jų antiradikalinį aktyvumą. Metodika. Bendras fenolinių junginių kiekis, buvo nustatytas naudojant farmakopėjinį Folino Ciocalteu metodą pagal galo rūgšties ekvivalentą. Flavonoidų kiekis nustatytas naudojant spektrofotometrinį metodą pagal rutino ekvivalentą. Antioksidacinis aktyvumas spektrofotometriškai buvo nustatomas naudojant DPPH radikalą. Efektyviosios skysčių chromatografijos su elektrocheminiu detektoriumi būdu buvo identifikuoti fenoliniai junginiai ir nustatytas jų antiradikalinis aktyvumas. Rezultatai. Didinant propolio koncentraciją, naudojant tirpiklius didėja bendras fenolinių junginių kiekis (p<0,05). Technologiniai procesai t.y. ekstrakcijos trukmė, temperatūros padidinimas daro reikšmingą įtaką fenolinių junginių išsiskyrimui (p<0,05). Didžiausias bendras fenolinių junginių kiekis 35,60 mg/ml buvo gautas naudojant ultragarsu skatinamą ekstrakciją 10 min esant 70 ⁰C temperatūrai, ekstrakcijos tirpikliu naudojant 30 proc. makrogolio ir vandens mišinį. Šiame ekstrakte nustatytas 88,76±1... [toliau žr. visą tekstą] / The aim of survey - to select the technology of nonethanolic propolis extract and analyse the active substances. Tasks: To examine the influence of concentration, solvent and its concentration, extraction time, temperature, the extraction method on release of total phenolic compounds. Determine the radical scavenging activity and flavonoid content of propolis extract and using high performance liquid chromatography method identify active substances and its antiradical activity. Methods: Total phenolic compounds were determined by using pharmacopoeial Folin Ciocalteu method expressed in gallic acid equivalents. Flavonoids were determined using a spectrophotometric method in rutin equivalent. Radical scavenging activity was determined by spectrophotometry using DPPH radical. High performance liquid chromatography with electrochemical detection were used to identify phenolic compounds and its radical scavenging activity. Results: Increasing of propolis concentration made a significance impact on the amount of total phenolic content (p<0,05). Extraction time, increase of temperature made a significance impact on increase of the amount of total phenolic content (p<0,05). The highest amount of total phenolic compounds 35,60 mg/ml were obtained using ultrasonic induced extraction for 10 minutes at 70 ⁰ C temperature and using 30 % macrogol – water solution as solvent. The radical scavenging capacity of this extract was 88,76 ± 1,27% and amount of flavonoids were 3,89 ± 0,43 mg/ml... [to full text]
83

Dermatologinių puskiečių formų su propolio produktais modeliavimas, optimizavimas ir biofarmacinis vertinimas / Modeling, optimization, and biopharmaceutical assessment of dermatological semisolid formulations with propolis products

Žilius, Modestas 18 June 2014 (has links)
Siekiant efektyvaus propolio fenolinių junginių poveikio odoje, svarbu sumodeliuoti veiksmingai šiuos junginius atpalaiduojančias ir tiekiančias į odą puskietes sistemas su propolio produktais. Darbo tikslas – pagrįsti puskiečių formų su propolio produktais modeliavimo principus, optimizuoti eksperimentines puskietes formas ir suformuluoti kokybės modelį, remiantis biofarmaciniais tyrimais. Įvertinta atskirų fenolinių rūgščių (vanilo, kavos, p-kumaro, ferulo rūgšties) ir vanilino skvarba į žmogaus odą ex vivo iš vandeninės propolio ištraukos ir eksperimentinių propolio puskiečių formų: tepalo, vanduo-aliejus tipo kremo, hidrogelio, aliejus-vanduo tipo gelifikuoto kremo. Patvirtintas aktyvus puskietės sistemos vaidmuo, atpalaiduojant ir darant įtaką propolio veikliųjų junginių skvarbai į odą. Įvertintas tirtų fenolinių junginių pasiskirstymas odos sluoksniuose (epidermyje ir dermoje), kuris susietas su skirtingu jų lipofiliškumu. Santykinai lipofiliniai junginiai (ferulo ir p-kumaro rūgštis) kaupėsi epidermyje, o santykinai hidrofiliniai junginiai (vanilo rūgštis ir vanilinas) migravo į dermą. Kavos rūgštis, kurios tirtuose propolio produktuose yra mažesnis kiekis negu kitų fenolinių rūgščių, nustatyta tik epidermyje. Pritaikytas eksperimentų planavimas vaisto formų sudėties optimizavimui. Optimizavimo parametrai leido prognozuoti propolio veikliųjų junginių atpalaidavimą iš tirtų puskiečių sistemų. / In order to achieve a desired effect of propolis phenolic compounds in the skin, it is important to develop semisolid systems with propolis products that would efficiently release and deliver these compounds into the skin. The aim of the study is to justify the modeling principles of semisolid formulations with propolis products, to optimize experimental semisolid formulations, and to formulate a quality model based on biopharmaceutical studies. The penetration of individual phenolic acids (vanillic, caffeic, p-coumaric, and ferulic) and vanillin from aqueous propolis extract and experimental propolis semisolid formulations (ointment, water-in-oil cream, hydrogel, and oil-in-water gelified cream) into the human skin ex vivo have been evaluated. An active role of the semisolid system in releasing and influencing the penetration of propolis active compounds into the skin has been confirmed. The distribution of investigated phenolic compounds in the layers of skin (epidermis and dermis) was evaluated and linked to different lipophilicity. Relatively lipophilic compounds (ferulic and p-coumaric acids) accumulated in the epidermis and relatively hydrophilic compounds (vanillic acid and vanillin) migrated to the dermis. Caffeic acid, which was present in analyzed propolis products at lower quantities as compared with other phenolic acids, was determined only in the epidermis. The design of experiments was applied for the optimization of the composition of dosage forms. Optimization... [to full text]
84

Composição química e atividade biológica do extrato hidroalcoolico de própolis preta. / Chemical composition and biological activity of the hydroalcoholic extract of black propolis.

CUNHA, Marcelo Holanda da. 05 June 2018 (has links)
Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-06-05T13:11:17Z No. of bitstreams: 1 MARCELO HOLANDA DA CUNHA - DISSERTAÇÃO PPGSA PROFISSIONAL 2018..pdf: 1249369 bytes, checksum: 6fd10dae8346a148f59677b96d3a3f5a (MD5) / Made available in DSpace on 2018-06-05T13:11:17Z (GMT). No. of bitstreams: 1 MARCELO HOLANDA DA CUNHA - DISSERTAÇÃO PPGSA PROFISSIONAL 2018..pdf: 1249369 bytes, checksum: 6fd10dae8346a148f59677b96d3a3f5a (MD5) Previous issue date: 2018-03-05 / Neste trabalho buscou-se investigar a composição química, o efeito antifúngico e antibacteriano do extrato da própolis preta, in vitro, em leveduras do gênero Candida e bactérias do grupo Staphylococcus aureus, respectivamente. A princípio obteve-se as amostras de 06 (seis) espécies de Candida spp. e 01(uma) de Sthaphylococus aureus por doação. Assim como, a própolis proveniente da jurema preta, cedida pelo apiário Edimel. A própolis preta foi extraída e sua composição química foi caracterizada por Cromatografia Líquida de Alta Eficiência. Posteriormente, os extratos hidroalcoolicos da própolis preta foram elaborados por dois métodos, a saber: maceração a quente e Soxhlet, com o intuito de se obervar a melhor forma de obter a melhor síntese e seu rendimento do referido extrato. Em seguida, as leveduras do gênero Candida sp foram reidratadas e semeadas, enquanto que a bactéria Sthaphylococus aureus foi replicada. As amostras viáveis foram testadas quanto ao perfil de sensibilidade considerando-o como sensível, sensibilidade dose-dependente e resistente utilizando como método de referência o teste de difusão em disco, de acordo com os documentos M44-A2 e M2-A8 do Clinical and Laboratory Standards Institute, respectivamente. Os resultados evidenciaram que o perfil químico da própolis preta consta de 14 substâncias químicas, e dentre elas, destacam-se as maiores concentrações para o ácido 3,4-dihidroxibenzoico (14,19 mg/mL), a rutina (12,71 mg/mL), o ácido transcinâmico (6,25 mg/mL), sendo esses responsáveis por atividade antioxidante e antibacteriana. Os processos de extração hidroalcoólica da própolis por maceração a quente e por soxhlet, resultaram respectivamente, em 43,6% e 57,6% de rendimento. Sugerindo que a extração por soxhlet apresentou melhor viabilidade, em virtude de redução de tempo e aumento na temperatura frente à maceração a quente. No que concerne, a reidratação e semeaduras das culturas de leveduras do gênero Candida sp, 100% das amostras apresentaram crescimento satisfatório para o desenvolvimento dos testes de sensibilidade. No entanto, o extrato hidroalcoólico de própolis preta testado nas concentrações de 26,4 mg/mL (33%), 52,8 mg/mL (66%) e 79,2 mg/mL (99%) e do álcool etílico a 70%, todos frente ao crescimento das 06 (seis) espécies de Candida, que se observaram ser resistentes ao extrato, enquanto para o fluconazol na concentração de 25 mg/mL, marcador antifúngico, foram sensíveis. Já, para o teste de difusão em disco com o extrato hidroalcoólico de própolis preta testado nas concentrações de 26,4 mg/mL (33%), 52,8 mg/mL (66%) e 79,2 mg/mL (99%), bem como do cloranfenicol na concentração de 30 mg/mL e do álcool etílico a 70%, frente ao crescimento da espécie de Staphylococcus aureus, estes apresentaram sensibilidades frente ao marcador antibacteriano e aos extratos. A formação dos halos por S. Aureus, indicando a sensibilidade tanto para os extratos hidroalcoólicos da própolis preta, cujos diâmetros foram entre 19 a 25,3 mm, e no marcador (Cloranfenicol) com diâmetro entre 30 a 30,1 mm. Em suma, pode ser afirmado que a própolis preta apresentou atividade antibacteriana para bactérias da espécie Staphyloccocus aureus, não havendo atividade antifúngica frente as leveduras do gênero cândida. Efeito esse relacionado à presença de compostos fenólicos e flavonóides, e que a predominância da concentração desses compostos bioativos, influencia na ação biológica dos microorganismos, estudados neste trabalho, Candida sp e Staphylococus aureus, em virtude de ter apresentado inibição e sensibilidade, respectivamente para esses microorganismos. / We studied the chemical composition of the black propolis extract, and its in vitro antifungal and antibacterial effects against yeasts of the genus Candida spp. (six species) and the bacterium Staphylococcus aureus. The propolis from Mimosa hostilis (Jurema-preta) flowers was provided by the Edimel apiary. Black propolis was extracted, and its chemical composition was measured by High-Performance Liquid Chromatography. Hydroalcoholic extracts of black propolis were done through two methods, hot maceration and Soxhlet, to obtain the best synthesis and yield. The yeasts were rehydrated and sown, whereas the bacterium was replicated. Viable samples were tested for sensitivity profile and classified as: sensitive, dose-dependent, and resistant. For the disc diffusion test, we followed reference methods described in the M44-A2 and M2-A8 documents of the Clinical and Laboratory Standards Institute, respectively for Candida spp. and S. aureus. The chemical profile of black propolis comprises 14 chemical substances. The compounds with highest concentrations were: protocatechuic acid (14.19 mg/mL), rutin (12.71 mg/mL), and transcinnamic acid (6.25 mg/mL), which were responsible for the antioxidant and antibacterial activity. The hydroalcoholic extraction processes of propolis by hot maceration and Soxhlet resulted in yields of 43.6% and 57.6%, respectively. Thus, the Soxhlet extraction showed better viability due to its faster extraction and increase in temperature. After rehydration and sowing, all samples of yeast cultures showed satisfactory growth for the sensitivity tests. All Candida species were resistant to the extract of black propolis (at the concentrations of 26.4 mg/mL – 33%; 52.8 mg/mL – 66%; and 79.2 mg/mL – 99%), and to 70% ethanol, whereas they were sensitive to fluconazole at 25 mg/mL, the antifungal marker. The S. aureus was sensitive to the extracts at all concentrations and to chloramphenicol at 30 mg/mL, the antibacterial marker. The halos around the discs show the sensitivity of S. aureus to both hydroalcoholic extracts of black propolis, whose diameters ranged from 19 to 25.3 mm, while the marker halos ranged from 30 to 30.1 mm. So, the black propolis showed antibacterial activity against S. aureus but no antifungal activity against Candida spp. The antibacterial activity occurred due to the presence of phenolic and flavonoid compounds. The predominance of these bioactive compounds affects the biological activity of microorganisms.
85

Etude du stress oxydatif dans l’hypertrophie bénigne de la prostate et mise en évidence de l’effet de la propolis contre le cancer de la prostate in vivo sur un modèle animal de rat Wistar et ex vivo sur les cellules LNCaP du cancer de la prostate hormono-sensibles / Study of the oxidative stress in benign prostatic hyperplasia and the effect of propolis against prostate cancer in vivo on an animal model of Wistar rat and ex vivo on hormone-sensitive (LNCaP) prostate cancer cell lines

Zabaiou, Nada 23 October 2017 (has links)
L’HBP et le cancer de la prostate constituent les deux maladies prostatiques les plus répandues chez l’homme âgé. La compréhension de leur étiologie et de leur pathogenèse est nécessaire afin de permettre la prévention mais aussi la recherche et le développement de nouveaux agents thérapeutiques. Notre but est d’étudier l’implication du stress oxydatif dans l’HBP et d’étudier l’effet de l’extrait de propolis sur le cancer de la prostate in vivo chez le rat Wistar et in vitro sur les cellules LNCaP. Nous avons montré que : 1) Le stress oxydatif joue le rôle de promoteur dans le développement de l’HBP, 2) Le benzo(a)pyrène administré aux rats Wistar induit le développement du cancer de la prostate, 3) La propolis induit la diminution de la prolifération, de l’expression du Ki-67 (-49 %) et de l’expression de AhR chez le rat Wistar, 4) La propolis possède un effet antiprolifératif sur les cellules LNCaP via le blocage de la signalisation de AR. / BPH and prostate cancer are the two most prevalent prostatic diseases in elders. Understanding their etiology and pathogenesis is necessary in order to prevent them and to enhance both research and development of new therapeutic agents. Our goal is to study the implication of oxidative stress in BPH and to study the effect of propolis extract on prostate cancer in vivo in Wistar rats and in vitro on LNCaP cells. We have shown that: 1) Oxidative stress acts as a promoter in the development of BPH, 2) Benzo(a)pyrene administered to Wistar rats induces the development of prostate cancer, 3) Propolis induces a decrease in proliferation, Ki-67 expression (-49%) and AhR expression in the Wistar rat, (4) Propolis has an antiproliferative effect on LNCaP cells via AR signaling blockade.
86

Métodos de controle químico de amostras de própolis / Chemical control methods of propolis samples

Ricardo Gomide Woisky Do Rio 22 November 1996 (has links)
Propõe-se um conjunto de parâmetros e respectivos métodos para análise de amostras de própolis bruta e tinturas de própolis, com vistas ao seu controle químico. Para amostras de própolis bruta, propõe-se a determinação dos teores de fenóis totais, flavonóides, ácidos fenólicos, ceras, cinzas, substâncias voláteis e resíduo seco. Para a análise de tinturas, propõe-se a determinação dos quatro primeiros ítens acima, acrescidos do teor de álcool etílico e densidade. A adequação dos métodos apresentados para a determinação de fenóis totais, flavonóides e ácidos fenólicos foi avaliada através de sua aplicação a uma mistura contendo quantidades conhecidas de flavonóides e ácidos fenólicos. O percentual das diferenças entre os teores reais e os teores medidos na mistura padrão situaram-se sempre abaixo de 10,0%. O emprego do conjunto de análises propostas é exemplificado, através da determinação dos parâmetros em amostras de própolis bruta, coletadas em distintas localidades do Brasil, e em amostras de tinturas etanólicas e hidroalcoólicas de própolis. Todos os ensaios foram realizados em triplicata, o que permitiu verificar que os métodos propostos apresentam boa reprodutibilidade. As amostras de própolis analisadas apresentam teores de fenóis totais cerca de 30% inferiores à média dos resultados relatados para amostras de origem européia. Os teores de flavonóides encontrados são muito pequenos, se comparados com os valores geralmente reportados para amostras de própolis de regiões temperadas. / A number of parameters and respective methods of analysis for chemical control of samples and tinctures of propolis is presented. It is suggested the determination of the contents of total phenolics, flavonoids, phenolic acids, waxes, ashes, volatile substances and dry residue for chemical control of samples of crude propolis. For propolis tinctures, in addition to the first four parameters it is proposed the determination of the density and the content of ethyl alcohol. The validity of the proposed methods for quantification of total phenolics, flavonoids and phenolic acids was evaluated by means of analysis of a mixture containing known quantities of several flavonoids and phenolic acids. The percentages of the differences between the actual contents and the measured quantities in the standard mixture remained always below 10,0%. The utility of the proposed methods is shown by the determination of the proposed parameters in samples of crude propolis collected in distinct localities of Brasil, and also in samples of ethanolic and hydroalcoholic tinctures of propolis. Because all assays were conducted as triplicates it was possible to demonstrate that all methods present good reproducibility. The samples of crude propolis assayed showed contents of total phenolics 30% below the average of the values reported for samples of propolis from Europe. The contents of flavonoids are also relatively small when compred with the contents generally reported for samples of propolis from temperate regions.
87

Efficacy of propolis against fusobacterium nucleatum biofilm

Griglione, Anthony Leonard January 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The primary goal of root canal treatment is to eliminate microbes from the root canal system, which is the cause of pulpal and periapical infections. Research shows that after a single visit of chemomechanical debridement microbes continue to remain within the canal system. An interappointment medication step has been advocated to maximize potential elimination of microbes within the root canal system. Previous studies have shown propolis to be antibacterial against common endodontic microbes. Studies have shown trends in different microbes being present in primary verus secondary endodontic infections. The majority of literature has focused on the efficacy of propolis against Enterococcus faecalis, a microbe commonly implicated in secondary endodontic 95 infections. The aim of this study was to demonstrate the efficacy of propolis against Fusobacterium nucleatum, a microbe commonly found in primary endodontic infections. This study aims to demonstrate the efficacy of propolis against a bacterium of primary endodontic infections (F. nucleatum) as well as against microbial biofilm to further support its potential use as a novel intracanal medicament. Dilutions of propolis were added to cultures of F. nucleatum in microtiter plates in a range from 390 μg/ml to 50,000 μg/ml. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and the minimum biofilm inhibitory concentration (MBIC) were determined. The MIC was determined of the total solution (biofilm+planktonic), planktonic, and biofilm (MBIC) after a 48-hour incubation period. The MBIC was determined by fixing biofilm to the wells and using crystal violet staining with spectrophotometry. The MBC was examined by plating solution from each concentration test well and reading the plates after 48 hours of incubation. The results show that the MIC of the total (biofilm+planktonic) appears to occur at a concentration of 6250 μg/ml. The MBIC appears to occur at the concentration of 1562.5 μg/ml. The planktonic results exhibit no significant difference in test and control wells. There was no MBC at any of the test concentrations. The propolis appears to inhibit bacterial growth and biofilm formation but does not appear to be bactericidal at any of the tested concentrations. The results of this study indicate that propolis has an MIC and MBIC when tested in vitro against F. nucleatum, although it does not show an MBC. There appears to be potentially significant interaction of propolis with biofilm as displayed by the lower concentration needed to exibit inhibitory effects on biofilm formation. This information 96 may contribute to the ability to develop a proper concentration of propolis to use in vivo when treating endodontic infections.
88

Application of gas chromatography and mass spectrometry for analysis of propolis from different geographic regions

Christov, Roumen January 2004 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.
89

Efeitos da própolis verde brasileira sobre a proteinúria e função renal em pacientes com doença renal crônica: um estudo clínico randomizado, duplo-cego, placebo-controlado / Effects of Brazilian green propolis on proteinuria and renal function in patients with chronic kidney disease: a randomized, double-blind clinical study, placebo-controlled

Silveira, Marcelo Augusto Duarte 02 May 2019 (has links)
A Doença Renal Crônica (DRC) é um importante problema de saúde pública ao redor do mundo e a proteinúria é um marcador de progressão da doença bem estabelecido. A própolis, uma resina natural produzida por abelhas a partir de resíduos e seivas de diferentes partes de plantas, possui propriedades anti-inflamatória, imunomoduladora, anti-câncer, anti-oxidante, bem como demonstrou ter efeito antiproteinúrico em modelo experimental de DRC. O objetivo deste estudo foi avaliar o efeito do extrato de Própolis verde brasileiro na proteinúria e ritmo de filtração glomerular estimada (RFG) em pacientes com DRC. Este foi um estudo clínico, randomizado, duplo-cego, controlado por placebo que reuniu pacientes com DRC de etiologias diabética e não-diabética, com idade entre 18 e 90 anos, com RFG estimado entre 25-70 ml/min/1.73 m2 e proteinúria (excreção urinária de proteína > 300mg/dia) ou microalbuminúria ou macroalbuminúria (taxa urinária de albumina-creatinina > 30mg/g Cr ou > 300mg/g Cr, respectivamente). Nós pesquisamos 148 pacientes e selecionamos randomicamente 32 para receberam, por 12 meses, extrato de própolis verde brasileiro na dose de 500mg/dia (n=18) ou placebo (n=14). No final do tratamento, a proteinúria foi significantemente menor no grupo Própolis do que no grupo Placebo--695 mg/24 h (IC de 95%, 483 a 999) x 1403 mg/24 h (IC de 95%, 1031 a 1909); P=0.004--independente de variações no RFG e pressão arterial, os quais não foram diferentes entre os grupos. O subgrupo de pacientes com DRC de etiologia diabética que recebeu Própolis apresentou redução significativa da albuminúria ao final do estudo (de 981 mg/g uCr [IC de 95%, 223 a 1739] para 476 mg/g uCr [IC de 95%, -282 a 1235]; p= 0,031), ao passo que o subgrupo de diabéticos que recebeu Placebo apresentou elevação da albuminúria (de 1261 mg/g uCr [IC de 95%, 569 a 1953] para 1451 mg/g uCr [IC de 95%, 758 a 2143]; p = 0,999). O Monocyte Chemoattractant Protein-1 (MCP-1) urinário também foi menor no grupo Própolis do que no grupo Placebo ao final do tratamento -- 58 pg/mg Cr [IC de 95%, 36 a 95] x 98 pg/mg Cr [IC de 95%, 62 a 155]; P=0.038. O extrato de própolis verde brasileiro foi seguro e bem tolerado, bem como reduziu significativamente a proteinúria em pacientes com DRC de etiologia diabética e não-diabética / Chronic kidney disease (CKD) is a public health problem worldwide, and proteinuria is a well-established marker of disease progression. Propolis, a natural resin produced by bees from residues and sap of different parts of plants, has anti-inflammatory, immunomodulatory, anti-cancer, anti-oxidant properties, as well as having been shown to have an antiproteinuric effect in experimental CKD. The aim of this study was to evaluate the effect that Brazilian green propolis extract has on proteinuria and on the estimated glomerular filtration rate (eGFR). This was a randomized, double-blind, placebo-controlled study including patients with CKD caused by diabetes or non-diabetic etiology, 18-90 years of age, with an eGFR of 25-70 ml/min per 1.73 m2 and proteinuria (urinary protein excretion > 300 mg/day) or micro- or macro-albuminuria (urinary albumin-to-creatinine ratio > 30 mg/g or > 300 mg/g, respectively). We screened 148 patients and selected 32, randomly assigning them to receive 12 months of Brazilian green propolis extract at a dose of 500 mg/day (n=18) or 12 months of a placebo (n=14). At the end of treatment, proteinuria was significantly lower in the propolis group than in the placebo group--695 mg/24 h (95% CI, 483 to 999) vs. 1403 mg/24 h (95% CI, 1031 to 1909); P=0.004--independent of variations in eGFR and blood pressure, which did not differ between the groups during follow-up. The subgroup of patients with CKD of diabetic ethiology who received Propolis presented a significant reduction of albuminuria at the end of the study (from 981 mg / g uCr [95% CI, 223 to 1739] to 476 mg / g uCr [95% CI, (P = 0.031), whereas the subgroup of diabetics receiving Placebo presented elevation of albuminuria (from 1261 mg / g uCr [95% CI, 569 to 1953] to 1451 mg / g uCr [CI 95%, 758 to 2143], p = 0.999). Urinary Monocyte Chemoattractant Protein-1 (MCP-1) was also significantly lower in the propolis group than in the placebo group -- 58 pg/mg creatinine (95% CI, 36 to 95) vs. 98 pg/mg creatinine (95% CI, 62 to 155); P=0.038. Brazilian green propolis extract was found to be safe and well tolerated, as well as to reduce proteinuria significantly in patients with diabetic and non-diabetic CKD
90

Análise química e atividades antioxidante e citotóxica de amostras de própolis de alecrim / Chemical characterization and antioxidant and citotoxic activities from alecrim propolis

Silva, Caroline Cristina Fernandes da 16 October 2008 (has links)
A própolis é uma mistura complexa de substâncias, constituída por ceras de abelhas e resinas de plantas. Sua coloração e textura são bastante variáveis, e a composição química difere com o local onde está localizada a colméia. As abelhas utilizam a própolis para selar aberturas na colméia, como revestimento interno, manutenção de um ambiente asséptico, entre outros propósitos. Suas propriedades farmacológicas são conhecidas há tempos, sendo que, dentre as principais, pode-se citar a ação antimicrobiana, a antiinflamatória, a antioxidante e a citotóxica. O presente trabalho teve como objetivos principais a caracterização química, por meio do doseamento de fenóis, ceras e flavonóides, de seis amostras de própolis verde, provenientes de Minas Gerais e do Paraná, e a identificação por CG/EM e CLAE/EM de algumas substâncias presentes nas amostras. Além disso, foram testados os extratos brutos metanólicos e as frações hexânicas, clorofórmicas, metanólicas e de acetato de etila das amostras, quanto à atividade citotóxica em embriões de ouriço-do-mar, e quanto à atividade antioxidante. A caracterização química ocorreu através da quantificação do teor de ceras, por gravimetria, que variou de 38,79 a 104,6 mg/g. Os teores de fenóis totais foram obtidos através de reação colorimétrica com o reagente Folin-Ciocalteau (&#955 760 nm) e variou de 132,69 a 187,57 mg/g. A quantificação de flavonas e flavonóis ocorreu através da reação com AlCl3 (&#955=420 nm), variando de 15,17 a 40,42 mg/g. Os teores de flavanonas e isoflavonas foram quantificados através da reação com a dinitrofenilhidrazina (&#955=486 nm), sendo obtidos os valores de 11,95 a 18,91 mg/g. Os perfis cromatográficos mostraram-se bastante semelhantes, sendo identificadas 35 substâncias, predominando os derivados prenilados do ácido &#961-cumárico, ácidos cafeoilquínicos e alguns flavonóides. As atividades antioxidantes seguiram os métodos de redução do radical livre DPPH (2,2-difenil-1-picrilhidrazila, &lambda;= 517 nm) e o sistema &#946;-caroteno/ácido linoléico (&lambda;= 470 nm). Os resultados obtidos pelo primeiro método variaram de 10,50 a 18,56% (25 µg/mL), e pelo segundo método a variação foi de 71,2 a 84,1% (1 mg/mL). Alta atividade antioxidante, nas mesmas concentrações, também foi verificada nas frações de hexano, clorofórmio, acetato de etila e metanol, nos dois métodos. Possíveis relações entre a atividade antioxidante e os teores de fenóis e flavonas e flavonóis foram testadas através de correlação linear, pelo método dos mínimos quadrados, assumindo como significantes valores de R2 > 0,5. Verificou-se uma correlação positiva significativa entre a atividade antioxidante e os teores de fenóis no método do DPPH (R2 = 0,835). Essa correlação, entretanto, não foi observada no sistema &#946-caroteno/ácido linoléico (R² = 0,450). Quanto ao teor e flavonas e flavonóis, observou-se uma correlação positiva significativa tanto no método do DPPH (R2 = 0,783) quanto no sistema &#961-caroteno/ácido linoléico (R2 = 0,693). A ausência de correlação com o método de descoloração do &#946-caroteno e a presença de atividade antioxidante em frações de menor polaridade sugere que substâncias solúveis em solventes menos polares estejam atuando como antioxidantes nas própolis estudadas. As atividades citotóxicas foram testadas em embriões de ouriço-do-mar Lytechinus variegatus e foram caracterizadas principalmente pela inibição da primeira clivagem dos ovos recém-fertilizados, demonstrando um efeito anti-mitótico. Foi utilizada a concentração de 32 &#956;g/mL de extrato para os testes, e a atividade variou de 97,33 a 100%. Na mesma concentração, verificou-se alta atividade nas frações de acetato de etila (100%), e baixa nas frações de metanol (&lt; 5%); nas frações de hexano e clorofórmio a atividade foi bastante variável (4,33 a 98,5% e 2 a 92,5%, respectivamente). Os resultados sugerem a presença de substâncias com potencial citotóxico e, possivelmente, antitumoral, importantes para o desenvolvimento de novos tratamentos para o câncer. Por meio das PCA e PCO concluiu-se que as própolis coletadas em Minas Gerais diferem entre si, inclusive entre aquelas de mesma localização. As amostras coletadas no Paraná se mostraram muito semelhantes nas duas análises. Houve, entretanto, diferenças significativas entre as amostras A-D, coletadas em Minas Gerais, e aquelas, E e F, coletadas no Paraná. / Propolis is a complex mixture of substances derived from bee products and plant resins. Propolis color and texture vary widely and chemical composition is dependent on the hive locality. Bees use propolis to seal openings in the hive and to line it internally, which help keeping the environment aseptic. Propolis properties in medicine has been known since ancient times, and more recently activities such as antimicrobial, anti-inflammatory, antioxidant and cytotoxic have been demonstrated. The present work aimed to characterize chemically six samples of green propolis produced in the states of Minas Gerais and Paraná and identify their constituents by GC/MS and HPLC/MS. In addition, this investigation aimed to evaluate cytotoxic and antioxidant activities of the crude hexane, chloroform, ethyl acetate and methanol extracts of all samples. Chemical characterization was carried out by the determination of the contents of wax, total phenols and flavonoids. Wax content was determined by extracting the waxes with chloroform, followed by purification with cold methanol and gravimetric determination. Wax contents varied from 28.79 to 104.6 mg/g. Total phenols were determined with the Folin-Ciocalteau reagent and. Values obtained varied in the range 132.69 - 187.57 mg/g. Flavone and flavonol contents combined were determined by the AlCl3 method and values obtained varied from 15.72 to 40.42 mg/g. Contents of flavanones and isoflavones combined were determined by the dinitrophenylhydrazine method, values varying in the range 11.95 -18.91. Chromatographic patterns were similar for all samples, with the predominance of derivatives of &#961-coumaric acid, caffeoylquinic acids and few flavonoids. Antioxidant activity determination followed the methods of the free radical DPPH (2,2-diphenyl-1-picrihydrazyl) and the &#946;-carotene/linoleic acid. Results relative the former method and the crude methanol extract at 25 g/mL, results varied from 10.50 to 18.56%; regarding the latter method and the crude methanol extract at 1 mg/ml, results varied in the range 71.2 - 84.1%. High antioxidant activities at the same concentrations and using both methods were observed with the hexane, chloroform, ethyl acetate and methanol fractions. Relationships between antioxidant activity and contents of total phenols and flavonoids of the crude methanol extract were tested by means of linear correlation and the minimum square method, assuming as significant values of R2 > 0.5. Positive significant correlation was observed between antioxidant activity and total phenol contents determined with the DPPH method (R2 = 0.835). No significant correlation was obtained, however, with the &#946;-carotene/linoleic acid method (R2 = 0.450). As to the flavone plus flavonol content, positive correlation was obtained with both DPPH and &#946;-carotene/linoleic acid methods (R2 = 0.783 and 0.693, respectively). No correlation with the &#946;-carotene discoloration method and high antioxidant activity of fractions obtained with low polarity solvents suggest that lipophylic chemical constituents exert antioxidant activity in analyzed samples. Cytotoxic activities of crude methanol extracts at 32 &#956;g/mL were determined using sea urchin (Lytechinus variegatus) embryos, taking into account mainly the inhibition of the first cleavage of recently fertilized eggs, which characterize an anti-mitotic effect. Values obtained varied in the range 97.33 - 100%. At the same concentration, high activities were obtained with the ethyl acetate fraction (100%) and low activities with methanol fraction (&lt; 0.5%). Regarding hexane and chloroform fractions, values varied widely (4.33 - 98.5% and 2 92.5%, respectively). Based on chemical composition, PCA and PCO analyses were carried out aiming the establishment of affinities among the six propolis samples. The results indicate that the samples from Minas Gerais differ significantly from those of Paraná The two samples of Paraná are very similar; however, significant differences exist among the four samples of Minas Gerais, even among samples from the same locality.

Page generated in 0.4546 seconds