• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 18
  • 7
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 40
  • 16
  • 15
  • 12
  • 7
  • 6
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 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.
11

Desenvolvimento de carreador lipídico nanoestruturado (CLN) como sistema de co-encapsulação de curcuminóides e timol para aplicação tópica / Development of nanostructured lipid carrier (NCL) as a co-encapsulation system of curcumin and thymol for topical application

Souza, Patrícia Fernanda de 29 January 2018 (has links)
A pele desempenha um importante papel na homeostasia e é uma via muito utilizada na administração de fármacos. O envelhecimento compromete sua função protetora e contribui para o aparecimento de sintomas como a rugosidade, flacidez, secura, prurido, hiperpigmentação dificuldade de cicatrização e a incidência de melanomas. Os raios UV são a principal causa do envelhecimento devido à geração de espécies reativas de oxigênio (ROS) e peroxidação lipídica. Os danos causados pelos ROS podem ser mitigados pelo uso de antioxidantes tópicos como a curcumina e timol (TML). No entanto, a baixa permeabilidade e estabilidade são fatores limitantes para sua aplicação. Para superar esses desafios, ECUR e TML podem ser encapsulados em nanopartículas, como os carreadores lipídicos nanoestruturado (CLN). Assim, os objetivos desse projeto foi desenvolver um CLN estável com manteiga Illipê, óleo de calêndula e TPGS para co-encapsular ECUR e TML e incorporação em uma formulação tópica. O padrão analítico dos curcuminóides foi isolado de amostra comercial, identificado por LC-MS e RMN e a metodologia analítica para quantificação CUR e TML foi validada. Os CLNs foram produzidos por emulsão quente e sonicação e otimizados utilizando a ferramenta de DoE Box-Behnken. Foram caracterizados em relação às propriedades físicas, citotoxicidade em cálulas HaCaT e atividade antioxidante. O CLN otimizado apresentou tamanho em torno de 130 nm, índice de polidispersão abaixo de 0,200 e potencial zeta negativo. A eficiência de encapsulação foi acima de 97% tanto para TML quanto CUR. CLN com e sem ativos demonstrou baixo índice de recristalização e forma esférica caracterização por DSC e AFM e não foram citotóxicos para células HaCaT, mostrando viabilidade celular superior a 80% na concentração 1,48x1012 partículas/ml, correspondente a 0,8 ?g/ml de TML/CUR co-encapsulados. Além disso, TML/CUR livre e co-encapsulado mostrou alta atividade antioxidante em ensaios in vitro para inibição de xantina oxidade e auto-oxidação do pirrogalol, indicando sua potente capacidade de inibição da enzima superóxido dismutase mesmo quando encapsulados. O emulgel tópico foi desenvolvido e apresentou estabilidade física após a incorporação do CLN no teste de estabilidade acelerada. O perfil reológico do emulgel demonstrou característica plástica e reoplexa e se manteve estável com o tempo e sob as variações de temperatura de analise, indicando alta estabilidade física da formulação. O perfil de liberação de ECUR e TML indicou cinética de liberação correspondente ao modelo de Higuchi sem influência da co-encapsulação na liberação da CUR e com liberação mais lenta do TML encapsulado. Os dados de permeação sugerem que os ativos possam permear na pele. A extensão e a intensidade da permeabilidade dos ativos promovida pelo CLN determinarão a aplicabilidade da formulação que poderá ser interessante para o desenvolvimento de um produto cosmético, dermocosmético, ou mesmo para um medicamento transdérmico. Em conclusão, o CLN desenvolvido apresentou características físicas e biológicas interessantes para a aplicação tópica. / Skin plays an important role in homeostasis and it is an important route for drug delivery. Aging compromises its protective function and contributes to the appearance of symptoms such as roughness, sagging, dryness, pruritus, hyperpigmentation, scarring deficient and the incidence of melanomas. UV rays are the main cause of photo-aging due of ROS generation and lipid peroxidation. ROS damage can be mitigated by using topical antioxidants as curcumin and thymol. However, low permeability and physico-chemical stability are disadvantages for its clinical application. To overcome these challenges, ECUR and TML can be encapsulated in nanoparticles such as nanostructured lipid carriers (NLC). This project aimed to develop a stable NLC composed by Illipê butter, calendula oil and TPGS to co-encapsulate ECUR and TML, followed by the NLC incorporation into a cosmetic formulation. Curcuminoid\'s analytical standard was isolated from commercial sample, identified by LC-MS and NMR, and the analytical methodology for quantification CUR and TML was validated. NLCs were produced by sonication emulsification method and their development was designed by Box-Behnken DoE and characterized in relation to physical properties, HaCaT cell cytotoxicity and antioxidant activity. Optimized NLC with size around 130 nm, polydispersity index (PdI) below 0.200 and negative zeta potential was obtained. The encapsulation efficiency (EE%) was above 97% for both TML and CUR. Empty and co-encapsulated NLC showed in DSC and AFM characterization low recrystallization index and spherical shapes and were not cytotoxic for HaCaT cells, showing cell viability over 80% at the maximum concentration evaluated (1.48x1012 particles / ml, wich corresponds to 0.8 ?g / ml co-encapsulated TML / CUR). Furthermore, free and co-encapsulated TML / CUR showed high antioxidant activity in in vitro assays due inhibition of xanthine oxidation and pyrogallol autoxidation, indicating their potent superoxide dismutase inhibition even when co-encapsulated. The cosmetic emulgel was developed and physically stable after NLC incorporation in accelerated stability. Emulgel rheological profile showed a plastic and rheopexy characteristic, which remained storage stability. The rheological profile did not change due variations in the temperature analysis, indicating good formulation physical stability and cosmetic acceptability. The release profile of ECUR/TML release kinetics corresponded to the Higuchi model without influence of co-encapsulation with slower release of the encapsulated TML. Permeation data suggest that the active substances may permeate deep into skin. The actives permeability extent and intensity promoted by CLN will determine the applicability of the formulation that can be interest for the development of a cosmetic, dermocosmetic product or even for a transdermal drug. In conclusion, the developed CLN presented interesting physical and biological characteristics for topical application.
12

Alterações morfológicas dos ovários de Rhipicephalus microplus submetidos ao tratamento com Lippia sidoides e Lippia gracilis / Morphological alterations of Rhipicephalus microplus ovaries submitted to treatment with Lippia sidoides and Lippia gracilis

Penha, Tatiane Aranha da 31 October 2016 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-12T20:06:08Z No. of bitstreams: 1 TatianePenha.pdf: 1070731 bytes, checksum: 317d377ddfce7d741b49eecde3cf7ec4 (MD5) / Made available in DSpace on 2017-05-12T20:06:08Z (GMT). No. of bitstreams: 1 TatianePenha.pdf: 1070731 bytes, checksum: 317d377ddfce7d741b49eecde3cf7ec4 (MD5) Previous issue date: 2016-10-31 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / The tick Rhipicephalus microplus, found in tropical and subtropical regions, has caused great harm to the Brazilian livestock. The damage caused by this tick the Brazilian livestock exceeds three billion dollars. Verbenaceae Lippia genus, especially the species L. sidoides and L. gracilis, have been reported with potential activity in larvae and R. microplus females. Therefore, the aim of this study was to evaluate the acaricide activity of L. sidoides and L. gracilis essential oils and its major compounds thymol and carvacrol and characterize morphological changes in ovaries of R. microplus females from lethal concentrations 50 (LC50) and 75% (LC75) of the study population. After selection of the genotypes (LGRA-106, LGRA-201, LSDI-102 and LSDI-103), groups of 10 engorged females were subjected to the immersion test in essential oils at different concentrations and DMSO 3% was used for the control. After seven days, the ticks were dissected in phosphate buffer solution and the ovaries were fixed in 2.5% glutaraldehyde for a period of 24 hours. The tissues were dehydrated and embedded in plastic molds Leica resin for histological analysis. The results visualization and characterization of the ovary and the different stages of development of oocytes. In the control group, treated with 3% DMSO, changes in the tissues have not been verified. In groups treated with the L. gracillis oils and L. sidoides oils, vacuolization was observed in oocytes II, III, IV and V, cell membrane disintegration in oocytes II, III, IV and V, with complete morphological deformation of oocytes IV and V. The major compounds, thymol and carvacrol seem to be actively working on these changes. The results showed activity of the different genotypes of the essential oils and their major compounds in larvae and females of R. microplus and allowed to elucidate the mechanism of action of the same in the oogenesis of the females, leading to believe that the compounds tested are promising for the development of acaricide products. / O carrapato Rhipicephalus microplus, encontrado em regiões tropicais e subtropicais, ocasionam mais de três bilhões de dólares à pecuária brasileira. Óleos essenciais de Verbenáceas do gênero Lippia, especialmente Lippia sidoides e Lippia gracilis, têm sido descritos com potencial atividade carrapaticida e interferindo na reprodução de diferentes espécies de carrapatos. O objetivo desse trabalho foi avaliar a atividade carrapaticida dos óleos essenciais de L. sidoides e L. gracilis e seus compostos majoritários timol e carvacrol, selecionando os genótipos que apresentam maiores atividades contra o carrapato bovino e caracterizar as alterações morfológicas dos ovários de fêmeas de R. microplus a partir das concentrações letais para 50 (CL50) e 75% (CL 75) da população estudada. Após a seleção dos genótipos (LGRA-106, LGRA-201, LSDI-102 e LSDI-103, grupos de 10 fêmeas ingurgitadas foram submetidas ao teste de imersão em óleos essenciais em diferentes concentrações e para o controle foi utilizado DMSO 3%. Após sete dias, as fêmeas foram dissecadas em solução tampão fosfato e os ovários foram fixados em glutaraldeído 2,5% por um período de 24 horas. Os tecidos foram desidratados e incluídos em moldes plásticos de resina Leica para análise histológica. Os resultados permitiram a visualização e caracterização do ovário e dos diferentes estágios de desenvolvimento dos ovócitos. No grupo controle (DMSO 3%), não foram verificadas alterações nos tecidos. Nos grupos tratados com os óleos de L. gracillis e L. sidoides foram observadas vacuolizações de ovócitos II, III, IV e V, desintegração de membrana plasmática em ovócitos II, III, IV e V, com completa deformidade morfológica de ovócitos IV e V. Os compostos majoritários, timol e carvacrol parecem estar atuando ativamente nessas alterações. Os resultados obtidos mostraram atividade dos diferentes genótipos dos óleos essenciais e seus compostos majoritários em larvas e fêmeas de R. microplus e permitiu elucidar o mecanismo de ação dos mesmos na oogêse das fêmeas, levando a crer que os compostos testados são promissores para o desenvolvimento de produtos carrapaticidas.
13

Avaliação da viabilidade celular de Candida albicans frente à ação antifúngica do timol

Vasconcelos, Laís César de 12 December 2013 (has links)
Made available in DSpace on 2015-05-14T12:56:03Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2062730 bytes, checksum: f8aa4f1dba574b15daf66619df74d887 (MD5) Previous issue date: 2013-12-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Candida albicans is a yeast that lives harmlessly on various parts of the human body, including the oral cavity, however, under certain circumstances, may cause superficial infections of the mucous membranes, such as denture stomatitis, in which a biofilm of Candida is formed on the acrylic surface of dentures. Thymol is a phenolic terpene found in several plant species, which has antimicrobial activity against oral microorganisms such as Candida albicans, since it can significantly interfere with fungal biofilm formation and inhibit the metabolic activity of these microorganisms by direct action on cell membrane. This study evaluated through fluorescence technique the cell viability of Candida albicans biofilms under the antifungal activity of thymol. It was used strains of Candida albicans (ATCC® 11006 ). The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the antifungal drugs (miconazole and thymol) were determined by microdilution tests in Sabouraud dextrose broth. The drugs were prepared in dimethylsulfoxide (DMSO) and the inoculum was standardized to correspond to 0.5 of McFarland s scale (106 UFC/mL). Biofilms of Candida albicans were grown, from Sabouraud broth supplemented with 10% dextrose, on the surface of acrylic resin disks in parallel flow chambers and, after 12 hours of biofilm formation in a continuous flow system, it was exposure to the antifungal agents, being evaluated periods of 5, 15 and 30 minutes. For counting of colony-forming units, the fungal solution was sequentially diluted and plated on Sabouraud dextrose agar. Cell viability was quantified by fluorescence by mixing SYTO 9 and Propidium Iodide dyes. Data were evaluated by analysis of variance (ANOVA), Tukey's test and t-test at 5% probability. Biofilms treated with thymol showed, on the three incubation times evaluated, low percentage numbers of viable cells detected by fluorescence technique, and the average of the three incubation times between miconazole and thymol were not statistically different (p˃ 0.05), demonstrating that both drugs possess equivalent efficiency, taking into account their respective minimum fungicidal concentrations. It was possible to prove that both methodologies used to quantify fungal cells showed to be strongly correlated. / Candida albicans trata-se de um fungo comensal que habita inofensivamente nichos de várias partes do corpo humano, incluindo a cavidade oral, no entanto, sob certas circunstâncias, pode causar infecções superficiais das mucosas, como a estomatite protética, na qual um biofilme de Candida é formado sobre a superfície acrílica das próteses dentárias. O timol é um terpeno fenólico encontrado em diversas espécies vegetais e que possui atividade antimicrobiana frente a microrganismos orais, tal como Candida albicans, pois é capaz de interferir de forma significativa com a formação de biofilmes fúngicos, uma vez que inibe a atividade metabólica destes microrganismos por ação direta na membrana celular. Este estudo objetivou avaliar através de técnica de fluorescência a viabilidade celular de biofilmes de Candida albicans frente à ação antifúngica do timol. Foram utilizadas cepas de Candida albicans (ATCC® 11006 ). A concentração inibitória mínima (CIM) e a concentração fungicida mínima (CFM) dos agentes antifúngicos (timol e miconazol) foram determinadas através de testes de microdiluição em caldo Sabouraud dextrose, sendo as drogas preparadas em dimetilsulfóxido (DMSO) e o inóculo padronizado para corresponder a 0,5 da escala de McFarland (106 UFC/mL). Os biofilmes de Candida albicans foram cultivados sobre a superfície de discos de resina acrílica, nas células paralelas de fluxo, a partir de caldo Sabouraud suplementado com 10% de dextrose, e, após 12 horas de formação do biofilme no sistema de fluxo contínuo, foi realizada a exposição aos agentes antifúngicos, sendo avaliados períodos de 5, 15 e 30 minutos. Para contagem das unidades formadoras de colônia, a solução fúngica foi sequencialmente diluída e semeada em ágar Sabouraud dextrose. A viabilidade celular foi quantificada por fluorescência através da mistura dos corantes SYTO 9 e Iodeto de Propídio. Os valores médios foram submetidos à análise de variância (ANOVA) e ao teste T em nível de 5% de probabilidade. Os biofilmes tratados com o timol apresentaram, nos três tempos de exposição avaliados, baixos números percentuais de células viáveis detectadas através da técnica de fluorescência, e os valores médios dos três tempos de exposição entre miconazol e timol não diferiram estatisticamente (p˃0,05), demonstrando que ambas as drogas possuem eficiência equivalente, levando-se em consideração suas respectivas concentrações fungicidas mínimas. Foi possível comprovar ainda que ambas as metodologias utilizadas para quantificação das células fúngicas apresentaram-se fortemente correlacionadas.
14

Effects of phytogenic compounds on growth and nutritional physiology of Nile tilapia (Oreochromis niloticus)

Aanyu, Margaret January 2016 (has links)
With increasing world population, the demand for fish is growing thus there is a need to identify products with potential to increase the efficiency of fish production. Phytogenics are among the products being investigated as potential naturally derived growth promoters. The aim of this study was to identify phytogenic compounds and doses with growth-promoting effects in Nile tilapia and investigate relevant pathways underlying their growth promotion effects. The phytogenic compounds limonene, carvacrol and thymol, major constituents of essential oils from the plants citrus, oregano and thyme, respectively, were evaluated. Six Trials (Trials I, II, III, IV, V and VI) were carried out using diets supplemented with varying concentrations of the phytogenic compounds. In Trials I, II and III (Chapter 3), the effects of either limonene (Trial I), carvacrol (Trial II) or thymol (Trial III) on growth performance of Nile tilapia were investigated (objective 1) and performance parameters including final fish weight, daily growth coefficient, growth rate per metabolic body weight, percentage (%) weight gain, % survival, feed intake, feed conversion ratio and protein efficiency ratio were evaluated. Results from Trials I, II and III indicated that dietary supplementation of 400 and 500 ppm limonene and 750 ppm thymol had growth-promoting effects in Nile tilapia but the somatic growth was not associated with enhanced feed intake and feed utilisation efficiency. Trials IV and V (Chapter 4) investigated growth and nutritional physiology pathways in Nile tilapia regulated by individual phytogenic compounds (objective 2). This was accomplished by analysing the effects of limonene (Trial IV) and thymol (Trial V) supplemented diets on the expression of key genes participating in selected pathways of somatotropic axis-mediated growth, appetite regulation, nutrient digestion, absorption and transport, lipid metabolism, and antioxidant enzyme defence system. Limonene was supplemented in the diet at 0, 200, 400 and 600 ppm while thymol was supplemented at 0, 250 and 500 ppm. Trials IV and V found that growth-promoting effects of limonene (400 and 600 ppm) in Nile tilapia involved up-regulation of key genes within pathways including somatotropic axis-mediated growth, nutrient digestion, absorption and transport, lipid metabolism and antioxidant enzyme defence system. Dietary thymol at 250 and 500 ppm did not significantly enhance growth of Nile tilapia nor regulate the nutritional physiology pathways listed above. In Trial VI (Chapter 5), the effects of combined phytogenic compounds (limonene and thymol) on growth and nutritional physiology of Nile tilapia was tested (objective 3) to establish if the compounds had synergistic or additive effects on the growth of the fish as well as complementary effects on the selected nutritional physiology pathways. A candidate gene approach was also used for the selected pathways. Results from Trial VI showed that a diet supplemented with a combination of limonene (400 ppm) and thymol (500 ppm) has neither synergistic nor additive effects on the growth performance of Nile tilapia, with limonene mainly influencing the attained somatic growth. The analysed candidate genes involved in the pathways of nutrient digestion, absorption and transport, lipid metabolism, antioxidant enzymes and somatotropic axis growth also showed no synergistic or additive effects of a dietary combination of limonene and thymol in Nile tilapia. Overall, results from the study suggest approaches for developing functional diets for Nile tilapia using limonene and thymol growth promoters.
15

Extending Spectrophotometric pHT Measurements in Coastal and Estuarine Environments

Douglas, Nora Katherine 06 April 2018 (has links)
Nearshore and estuarine environments play a vital role in the cycling of carbon, but the effects of ocean acidification in estuarine waters have not been studied as extensively as in the open ocean. One reason for this is the limitation of pH measurement capabilities in low-salinity waters. Typically, pH in these environments has been measured using potentiometric methods that are subject to uncertainties on the order of 0.01. Spectrophotometric methods for measuring pHT offer precision and accuracy superior to those of potentiometric methods. However, previous characterizations for purified sulfonephthalein indicators, used for marine spectrophotometric measurements, are not applicable to estuarine salinities. Some estuarine datasets using unpurified indicators exist, but the presence of dye impurities affects the accuracy of these characterizations. Colorimetric impurities are known to interfere with absorbance measurements and can cause errors in pH on the order of 0.02. In this work, a mathematical model has been developed to correct spectrophotometric pHT determined with unpurified m-Cresol Purple (mCP), the indicator used most widely for these measurements. The model accounts for absorbances of colorimetric impurities that interfere with absorbance by mCP. This corrective approach brings measurements made using unpurified mCP in synthetic solutions of 0.7 M NaCl into better agreement with those made using purified mCP: within ±0.004 pH units for all six indicators tested at pHT ≤ 8.0. The model is useful for both (a) research groups currently using unpurified mCP to measure pHT, and (b) retrospective correction of historic pHT datasets collected using unpurified mCP. The correction requires only that a small sample of the unpurified mCP is saved for a single-point test at high pHT (~12), and that historic absorbance measurements are archived for subsequent correction. The principles of the corrective model were applied to an historic calibration of the mCP dissociation constant (KI) at 0 ≤ S ≤ 40 and T = 298.15 K using unpurified indicator. After correction of absorbances for dye impurities, recalculation of KI was performed, and the recalculated values were combined with mCP KI data for freshwater and seawater. The combined dataset was then refitted as a function of S and T. The resulting model is representative of mCP behavior across 0 ≤ S ≤ 40 and 278.15 ≤ T ≤ 308.15 K and produces p(KIe2) values that are within ±0.004 of p(KIe2) values from previously published purified mCP calibrations. This refitting approach was also applied to pHT determinations made with Thymol Blue (TB) and Cresol Red (CR), two sulfonephthalein indicators that have been previously used in waters outside the indicating range of mCP. The models, which were of the same form as the estuarine p(KIe2) model for mCP, performed approximately as well as the mCP model: with the exception of one high-salinity, high-temperature TB datum, all residuals were within ±0.0043 of the previously published TB and CR calibrations. Finally, an internal consistency analysis was performed using carbon chemistry data collected during two recent coastal ocean acidification research cruises. For pHT measurements performed during both cruises, purified mCP was used, and corresponding measurements of total alkalinity (TA) and dissolved inorganic carbon (DIC) were conducted. Both cruises included excursions into the Columbia River, where low salinities prevent usage of the marine p(KIe2) model for purified mCP. The Columbia River samples provided the opportunity to evaluate the internal consistency of pHT measurements made in low-salinity waters using the refitted estuarine p(KIe2) model. Although internal consistency agreement in the estuarine range is poor compared to marine measurements, pHT calculated using the new estuarine model compared well with pHT calculated using the previously published estuarine mCP model. The poor internal consistency in the estuarine range, even when making state-of-the-art pH measurements, points toward the need for a more robust characterization of the carbonic acid dissociation constants in the estuarine salinity range. This characterization should take into account the contributions of organic acids to total alkalinity in nearshore waters.
16

Avalia??o das atividades anti-toxopl?smica, antioxidante e antiinflamat?ria dos monoterpenos timol (lippia sidoides) e estragol (croton zenhtneri)

Oliveira, Claudio Bruno Silva de 14 March 2012 (has links)
Made available in DSpace on 2014-12-17T14:10:26Z (GMT). No. of bitstreams: 1 ClaudioBSO_DISSERT.pdf: 2673133 bytes, checksum: 44082c33463f5700264efa7b77ae2f4c (MD5) Previous issue date: 2012-03-14 / Toxoplasmosis, a benign disease in normal healthy individuals, can have serious effects in pregnant women and immunocompromised patients. It is a parasitic disease caused by Toxoplasma gondii (Tg), an obligatory intracellular protozoan. The prophylactic and therapeutic arsenal against this parasite is very restricted. Thus, there is an ongoing search for novel drugs and therapeutic strategies. A promising alternative is a rational approach using medicinal plants. This study aimed to standardize methodologies for assessing the toxicological, antiproliferative, antioxidant, antiinflammatory and anti-Toxoplasma effects of Estragole and Thymol compounds isolated from species of plants (Lippia sidoides and Croton zenhtneri) commonly used in the Cariri region of Ceara State, Brazil. First we evaluated in vivo toxicity and conducted a pathological analysis of mice livers. In vivo antiinflammatory activity was assessed using air pouch and paw edema methods. Cytotoxicity assays were performed and antiproliferative, antioxidant and nitric oxide production analyzed. Anti-Toxoplasma activity was evaluated in a congenital experimental model with varying stages of maternal infection using the ME-49 strain and a non- congenital model by using ME-49 and RH strains. The results suggest low to moderate toxicity for both compounds. Thymol was more toxic in vivo and in vitro, having greater pathological repercussion than Estragole. The compounds were inactive for antiproliferative activity. Thymol showed better antioxidant activity, while Estragole stimulated nitric oxide production in macrophages. Both showed significant antiinflammatory activity. In non-congenital Tg infection, both compounds were active only against the ME49 strain. In congenital infection, Estragole (oral route) improved the newborn weight of infected mothers compared with untreated controls. Subcutaneous administration of the two compounds increased the weight of offspring born to infected mothers compared with untreated controls. We concluded that Estragole and Thymol exhibit important biological and anti-Toxoplasma activities. Further studies are needed to elucidate the mechanism of action of these compounds and other possible activities not investigated in the present study / A toxoplasmose, doen?a de curso benigno em pacientes imunocompetentes, mas que pode ocasionar graves acometimentos cl?nicos em imunossuprimidos e gestantes ? causada pelo Toxoplasma gondii (Tg), protozo?rio intracelular obrigat?rio. O arsenal profil?tico e terap?utico contra este parasito ? bastante restrito, tornando urgente a busca por novos medicamentos. Uma alternativa promissora ? a abordagem racional a partir de plantas medicinais. Neste estudo foram padronizadas metodologias objetivando avaliar os efeitos toxicol?gicos, antiproliferativos, antiinflamat?rios, antioxidantes e anti-toxopl?smicos do Timol e Estragol isolados, respectivamente, das esp?cies vegetais Lippia sidoides e Croton zenhtneri, usadas popularmente na regi?o do Cariri/CE para diversas mol?stias. Inicialmente foram realizados testes de toxicidade in vivo e an?lise patol?gica do f?gado dos camundongos. Avaliou-se a atividade antiinflamat?ria in vivo pelo m?todo da bolsa de ar e pela medida da varia??o do edema de pata. Ensaios de citotoxicidade in vitro foram realizados, bem como pesquisas de atividade antiproliferativa, antioxidante e produ??o de ?xido n?trico. A atividade anti-toxopl?smica foi avaliada em modelo murino de infec??o n?o cong?nita (usando Tg ME-49 e Tg RH) e cong?nita, com per?odos variados de infec??o materna (Tg ME-49). Os resultados sugerem toxicidade baixa a moderada para os dois compostos. O Timol se mostrou mais t?xico, in vivo e in vitro, e teve maior repercuss?o patol?gica do que o Estragol. Os compostos foram inativos para atividade antiproliferativa. O Timol apresentou ?tima atividade antioxidante enquanto o Estragol estimulou a produ??o de ?xido n?trico em macr?fagos. Ambos apresentaram significativa atividade antiinflamat?ria. Os dois compostos foram ativos apenas contra a cepa ME-49. No modelo de infec??o cong?nita o Estragol proporcionou um aumento significativo de peso neonatal em filhotes de m?es infectadas quando comparadas com o controle n?o tratado. O mesmo ocorreu com filhotes de m?es tratadas, via subcut?nea, com ambos os compostos ap?s 30 dias. Conclui-se que o Timol e o Estragol possuem importantes atividades biol?gicas e anti-toxopl?smica. Estudos posteriores s?o necess?rios para elucidar o mecanismo de a??o destes compostos, al?m de outras poss?veis atividades n?o investigadas neste estudo
17

Atividade antifúngica in vitro de timol sobre cepas do gênero Penicillium / antifungal activity of thymol against Penicillium strains

Dantas, Tassiana Barbosa 31 October 2013 (has links)
Made available in DSpace on 2015-05-14T13:00:00Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3314099 bytes, checksum: 6718a7629561d518b36935f1ca31ec59 (MD5) Previous issue date: 2013-10-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The fungi have become, over the last two decades, a major cause of illness in humans. Fungi of the genus Penicillium can be found in various substrates and affect immunocompromised people, hospitalized patients, many animals and plants, as well as compromise the quality of air indoors. The indiscriminate use of antibiotics and the resulting framework of resistance of microorganisms to conventional antimicrobial therapy has been stimulating researchers to seek alternative sources of these compounds, among them products derived by medicinal plants. Tendency to get phytochemicals from extracts, fractions, fixed or essential oils obtained from plant species is currently observed. In this context, the present study evaluated the in vitro antifungal activity of seven phytochemicals: carvacrol, citral, geraniol, linalool, pcymene, terpinolene and thymol, against twelve strains of Penicillium. Firstly, screening was carried out to find the phytochemical with the best activity by determining the Minimum Inhibitory Concentration (MIC) by the broth microdilution technique. Following, the tests were proceeded with thymol, which were: determination of Minimum Fungicidal Concentration (MFC), effect of the phytochemical on mycelial growth kinetics, interference of thymol on germination of conidia and evaluation of the influence of thymol on the fungal morphology. To this end, we selected two strains, one that was more resistant and another with a more sensitive profile. The value of thymol MIC50 and MIC90 was 128μg/ml, while the CFM value ranged from 128μg/ml to 1024μg/ml. It was observed total radial mycelial growth inhibition at the three thymol concentrations used (128μg/ml, 256μg/ml and 512μg/ml) over 14 days of exposure. In the study of the interference of thymol on the conidia germination was observed inhibitory effect. At the concentration of 512μg/mL was found greater than 80% inhibition, at 256 μg/mL inhibition was higher than 75%, while in 128μg/mL inhibition was higher than 60%, all this for both strains tested, revealing concentration-dependent inhibitory effect. In the presence of thymol, morphological changes were observed in mycelial structure, such as decrease in the amount of conidia, reduction in the formation of reproductive structures with the appearance of rudimentary reproductive structures, besides the abnormal development of hyphae. Given the above, it is concluded that thymol has antifungal activity against strains of Penicillium and therefore represents a new possibility in the arsenal of products for the treatment of infections caused by this fungus. / Os fungos tornaram-se, ao longo das últimas duas décadas, uma das principais causas de doença em humanos. Fungos do gênero Penicillium podem ser encontrados nos mais variados substratos e afetam indivíduos imunocomprometidos, pacientes hospitalizados, animais e plantas diversas, além de comprometerem a qualidade do ar de ambientes internos. O uso indiscriminado de antibióticos e o decorrente quadro de resistência dos microrganismos à terapêutica antimicrobiana convencional vem impulsionando os pesquisadores a buscarem fontes alternativas desses fármacos, dentre elas, produtos de plantas medicinais. Observa-se, atualmente, uma tendência à obtenção de fitoconstituintes a partir de extratos, frações, óleos fixos ou essenciais, obtidos de espécies vegetais. Nesse contexto, o presente estudo avaliou a atividade antifúngica in vitro de sete fitoconstituintes: carvacrol, citral, geraniol, linalol, pcimeno, terpinoleno e timol, sobre doze cepas de Penicillium. Primeiramente, realizou-se uma triagem para encontrar o fitoconstituinte com melhor atividade, através da determinação da Concentração Inibitória Mínima (CIM), pela técnica de microdiluição. A seguir, prosseguiram-se os testes com o timol, quais foram: determinação da Concentração Fungicida Mínima (CFM), efeito do fitoconstituinte sobre a cinética de crescimento micelial do fungo, interferência do timol sobre a germinação dos conídios e avaliação da influência do timol sobre a micromorfologia fúngica. Para tanto, foram selecionadas duas cepas, uma que se mostrou mais resistente e outra com perfil mais sensível. O valor da CIM50 do timol, bem como da CIM90, foi 128μg/ml, já o valor da CFM variou de 128μg/ml a 1024μg/ml. Observou-se total inibição do crescimento micelial radial, nas três concentrações de timol utilizadas (128μg/ml, 256μg/ml e 512μg/ml), ao longo de 14 dias de exposição. No estudo da interferência do timol sobre a germinação dos conídios, observou-se efeito inibitório. Na concentração de 512μg/mL foi encontrada uma inibição superior a 80%, em 256 μg/mL a inibição foi superior a 75%, enquanto que em 128μg/mL a inibição foi superior a 60%, para as duas cepas testadas, revelando um efeito inibitório dependente da concentração. Na presença do timol, foram observadas alterações morfológicas na estrutura micelial, tais como diminuição do número de conídios, redução da formação de estruturas de reprodução com surgimento de estruturas reprodutivas rudimentares, além de desenvolvimento anormal das hifas. Diante do exposto, conclui-se que o timol apresenta atividade antifúngica contra cepas de Penicillium e, conseqüentemente, representa uma nova possibilidade no arsenal de produtos para o tratamento de infecções por este fungo.
18

Estudo da composição Química do óleo essencial de Lippia microphylla CHAM em três anos diferentes e atividade antioxidante

Mauro Marcos da Silva 29 March 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O estado de Roraima é dividido em três grandes sistemas ecológicos: floresta, campinas-campinarana e savanas ou cerrados e está localizado no extremo norte da Amazônia brasileira. Apesar da grande variedade de plantas existem poucas informações sobre plantas aromáticas da região. Lippia microphylla Cham., pertence à família Verbenaceae e ao gênero Lippia, e conhecida popularmente em Roraima como salva do campo, sendo encontrada nos lavrados roraimenses. Esta planta pode ser encontrada com facilidade ao longo da BR 174 que liga Boa Vista a Santa Elena de Uairén, na Venezuela. O objetivo desse trabalho foi avaliar a constituição química do óleo essencial de Lippia microphylla Cham. em épocas e horários diferentes e analisar sua atividade antioxidante. As amostras foram coletadas no município de Boa Vista, Roraima, em três horários diferentes (8,12 e 18 horas) nos meses de maio 2009, 2010 e 2011. As folhas extraídas por hidrodestilação com auxílio de um aparelho de clevenger e os óleos foram analisados por cromatografia gasosa com auxílio da espectrometria de massas. Para determinação da atividade antioxidante do óleo essencial foi utilizado o método de capacidade sequestrante do radical livre DPPH. Os maiores rendimentos de óleos foram registrados em maio de 2011, mês que registrou maior precipitação, mas não choveu no dia da coleta. A análise da constituição do óleo revelou que o timol, carvacrol, E-cariofileno, nerolidol e o óxido de cariofileno foram os principais constituintes, sendo o carvacrol majoritário em quase todas as análises. O óleo de melhor capacidade antioxidante foi extraído do material coletado ao meio dia e contem maior concentração de timol (9,22%) e carvacrol (19,80%). Observamos que os óleos coletados nos diferentes anos apresentam diferenças significativas quanto a sua composição química e ao seu rendimento. A chuva do dia da coleta foi mais relevante do que o volume de precipitação no mês. A atividade antioxidante desses óleos pode ser atribuída principalmente à presença dos dois isômeros fenólicos. / The state of Roraima is divided into three major ecological systems: forests, meadow-campinarana and savannas, and are located in the extreme north of the Brazilian Amazon. Despite the wide variety of plants there is little information on herbs of the region. The Lippia microphylla Cham., belongs to the family Verbenaceae and the genus Lippia, popularly known as salva-do-campo being found in the Roraima savannas. This plant is easily found along the margins of the BR 174, the route Boa Vista, Brazil, to the Santa Elena de Uairén, Venezuela. The aim of this study was to evaluate the chemical composition of essential oil of Lippia microphylla Cham. Collected at different times and schedules and analyze their antioxidant activity. The samples were collected in Boa Vista, Roraima, at three different times ( 8, 12 and 18 hours ) in May 2009, 2010 and 2011, for realization of antioxidant activity the samples were collected in the month of March 2011. The leaves were extracted by hydrodistillation with the assistance of a Clevenger apparatus and the oils analyzed by Gas chromatography coupled with mass spectrometry, GC-MS. To determine the antioxidant activity of the essential oil the method of sequestering ability of the free radical DPPH was used. The highest yields of oils were recorded in May 2011, which recorded highest rainfall month, but it did not rain on the day of collection. The analysis of the constitution of the oils revealed that thymol, carvacrol, E-caryophyllene, nerolidol and caryophyllene oxide were the main constituents of which the majority carvacrol was in almost all analyzes. The best antioxidant capacity oil was extracted from material collected at noon containing higher concentration of thymol ( 9.22% ) and carvacrol ( 19.80% ). We observed that the oils collected in different years showed significant differences in their chemical composition and yield. The rain on the day of collection was more important than the volume of rainfall in the month. The antioxidant activity of these oils can be attributed mainly to the presence of two phenolic isomers.
19

Eficácia carrapaticida do timol em solubilização etanólica sobre larvas de Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Goldner, Márcio Scoralick January 2011 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-22T11:15:51Z No. of bitstreams: 1 marcioscoralickgoldner.pdf: 1368658 bytes, checksum: 524048ed973021e443fbeb565aadcf5d (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-24T13:12:02Z (GMT) No. of bitstreams: 1 marcioscoralickgoldner.pdf: 1368658 bytes, checksum: 524048ed973021e443fbeb565aadcf5d (MD5) / Made available in DSpace on 2017-06-24T13:12:02Z (GMT). No. of bitstreams: 1 marcioscoralickgoldner.pdf: 1368658 bytes, checksum: 524048ed973021e443fbeb565aadcf5d (MD5) Previous issue date: 2011 / O uso indiscriminado de carrapaticidas sintéticos e o quadro de resistência aos produtos utilizados no mercado impulsionaram novas pesquisas e alternativas ao combate aos parasitos hematófagos. Dentre as alternativas mais promissoras, pode-se evidenciar o uso de substâncias e seus derivados provenientes de plantas com objetivo de implementar de carrapaticidas de origem natural que podem ser menos prejudiciais ao meio ambiente. O presente trabalho teve por objetivo potencializar ‘’in vitro’’ a eficácia carrapaticida do timol frente a larvas de R. (B.) microplus. No primeiro experimento, foram elaboradas três formulações, visando à escolha do preparado com melhor custo-benefício sem que os diferentes componentes das formulações interferissem na eficácia carrapaticida. A formulação de escolha demonstrou a mortalidade de 96,65% das larvas mantendo a eficácia carrapaticida do timol a 2% acima dos limites preconizados pelo Ministério da Agricultura de 95% para produtos comerciais. No segundo experimento, foram testadas, na formulação eleita, as concentrações de 0,25%%, 0,5% e 1% de timol sobre larvas de R. (B.) microplus, sendo que a taxa de mortalidade obtida com 0.25% foi de 94%, demonstrando que mesmo com baixa concentração de timol a eficácia carrapaticida foi considerável. Os resultados alcançados mostram que, in vitro, a eficácia carrapaticida do timol pode ser não somente mantida, como potencializada se for levada em consideração a metodologia de preparo da formulação, bem como características físico-químicas dos seus componentes, visando minimizar perdas do princípio ativo. Entretanto, são necessárias pesquisas futuras para ratificar o potencial acaricida do timol em ambiente de campo, modificando e testando diferentes apresentações. / The indiscriminate use of synthetic acaricides and the picture of resistance to products used in the market spurred new research and alternatives to combat these hematophagous parasites. Among the most promising alternatives, it can be highlight the use of substances and their derivatives from plants, aiming to implement the carrapaticide products of natural origin that may be less harmful to the environment. This study aimed to ''enhance'' the in vitro acaricide efficacy of thymol against the larvae of R. (B.) microplus. In the first experiment, three formulations were prepared, in order to choose the most cost-prepared without any of the different components interfere with the efficacy of insecticide formulations. The formulation of choice showed 96.65% mortality of larvae still remain effective insecticide of the thymol 2% above the limits established by the Ministry of Agriculture of 95% for commercial products. In the second experiment, were tested in the formulation choice, the concentrations of 0.25%, 0.5% and 1% of thymol on larvae of R. (B.) microplus, with a mortality rate of 94% with 0.25% of thymol, demonstrating that even in low concentrations of thymol acaricide efficacy was considerable. The results show that in vitro, acaricide efficacy of thymol can be not only maintained, as increased if it is taken into account the preparation method of the formulation and the physicochemical characteristics of its components in order to minimize losses of active. However, further research is needed to ratify the acaricidal potential of thymol in a field environment, modifying and testing different presentations and to assess its impact on the environment.
20

Use of plant-derived essential oil compounds, naturally-occurring apple aroma compounds, and apple juice flavoring mixtures to control the growth of Escherichia coli O157:H7

Kumar, Mona 17 December 2012 (has links)
In recent years, there have been a number of studies looking at inhibition of microorganisms by spices, herbs or their extracts.  Many of these products have been shown to have antimicrobial activity against foodborne pathogens.  The purpose of this research was to evaluate the antimicrobial activity of three essential oil (EO) compounds (thymol, eugenol, and trans-cinnamaldehyde) alone and in combination with three naturally-occurring apple aroma (AA) compounds (hexanal, trans-2-hexenal and 1-hexanol) to identify the minimum inhibitory concentrations necessary to inhibit E. coli O157:H7.  Three commercial apple juice flavoring mixtures (natural apple cinnamon, natural apple spice and natural red apple) were additionally tested alone for antimicrobial activity against E. coli O157:H7. The standard agar dilution method (SAD) and checkerboard assay were used to evaluate the efficacy of the nine compounds, alone and in combination against E. coli O157:H7.  In general, the EO compounds were significantly more effective against E. coli O157:H7 than the AA compounds (P<0.05).  Cinnamaldehye, with an MIC of 0.2 mg/mL, exhibited the highest degree of activity, followed by thymol, eugenol and trans-2-hexenal, which each had individual MIC values of 1.6 mg/mL.  No synergism was found in the combinations of EO compounds with AA compounds. / Master of Science in Life Sciences

Page generated in 0.4173 seconds