Plant cell walls determine cellular shape and provide structural support for the entire plant. Polysaccharides, comprising the major components of the wall, are actively remodelled throughout development. Xyloglucan endotransglucosylase (XET)/hydrolase (XTH, EC 2.4.1.207) cleaves xyloglucan (XyG), the donor substrate, and attaches a portion to another XyG chain, the acceptor substrate. Recently, a novel transglucosylase called mixed-linkage β-glucan (MLG) : XyG endotransglucosylase (MXE) was discovered in horsetails (Equisetum spp.) that could attach a portion of MLG to XyG, resulting in a hetero-polymer product. My aims were to further investigate the nature of this activity, biochemically characterize the enzyme, and explore its physiological role. MXE activity was attributable to an enzyme unlike Equisetum XTHs. MXE had a p1 of 4.1 (XTHs were 6.6-9), a pH optimum of 6.3 (XTHs preferred 5.5), and had higher activity using smaller oligosaccharide acceptor substrates like XXXGol (XTHs were more active using XLLGol). Importantly, the MXE protein was shown to utilize both MLG and XyG as donor substrates, and therefore have both MXE and XET activity. Also, the enzyme was capable of using various glucan oligosaccharides (O) as substrates, including MLGO, XyGO, and cello-O, but not laminari-O. By using a novel ex vivo approach, the proportion of extractable MXE product to XET product was found to increase in older tissues. Transglucosylase products were localized in sclerenchyma and structural parenchyma by in situ assays, implying a strenghening function for MXE. Surprisingly, another novel activity was discovered that could covalently attach cellulose to XyG, and termed cellulose : xyloglucan endotransglucosylase (CXE). This activity was attributed to the MXE enzyme, implying that the protein is a promiscuous endotransglucosylase. The presence of CXE in other plants has not yet been tested. Besides being a novel discovery in plant cell biology, the modification of cellulose has applications in a number of industries.

AbstractA study was made to determine if the age of a herbarium specimen of Equisetum hiemale had any effect on the chromatographic patterns. Specimens of E. hiemale were analyzed employing descending paper chromatography and electrophoresis.The amino acid and phenolic patterns were of significant value in determining if the chromatographic patterns varied as the herbarium specimen aged. The fluorescent phenolic compounds of E. hiemale were analyzed by placing the chromatograms under long wave ultraviolet light. The free amino acids were detected by spraying the chromatogram. with ninhydrin.The chromatographic patterns showed that the age of the oldest herbarium specimen investigated had no effect on its patterns.Ball State UniversityMuncie, IN 47306

Estudos relataram a atividade antimicrobina de Equisetum giganteum e Punica granatum, reduzindo o risco do desenvolvimento da estomatite protética, doença relacionada principalmente à colonização das próteses pelo fungo Candida albicans. Diante disso, é necessário que essas plantas sejam bem toleradas pelos tecidos bucais e, se possível, auxiliem no processo de reparo. Objetivo: Realizar um estudo fitoquímico de substâncias potencialmente ativas de Equisetum giganteum e Punica granatum e avaliar a viabilidade de fibroblastos gengivais humanos frente a diferentes concentrações destas plantas, após diferentes períodos in vitro. Material e Métodos: Após a identificação dos compostos das plantas por HPLC-PAD, foram selecionadas as frações com melhor atividade antifúngica perante Candida albicans. Os extratos brutos e frações selecionadas de P. granatum e E. giganteum foram testados em diferentes concentrações (0.23, 0.47, 0.94, 1.88, 3.75, 7.5, 15 e 30 mg) e períodos (12, 24, 36 e 60 h) sobre fibroblastos gengivais humanos (FGH), para a avaliação de suas citotoxicidades através da análise da viabilidade dos FGH, pelo ensaio LIVE/DEAD. Por meio desse ensaio, analisamos quantitativamente a viabilidade celular através das leituras das unidades relativas de fluorescência (URF) e qualitativamente por meio da analise da morfologia e da densidade observadas pela microscopia invertida de fluorescência, após três experimentos independentes para cada período de avaliação. Os resultados quantitativos paramétricos foram representados como média e desvio padrão (SD) com análise de Variância ANOVAOne- Way, seguida da análise comparativa pelo teste de Tukey HSD. Os resultados quantitativos não paramétricos foram apresentados como mediana e quartis e foram submetidos ao teste de Kruskal-Wallis, seguido de análise comparativa pelo teste de Dunn, de acordo com as análises de normalidade (Teste de Kolmogorov-Smirnov). Valores de p< 0.05 foram indicativos de significância estatística. Conclusões: Foram identificados compostos fenólicos, como flavonoides e taninos em E.giganteum e P. granantum, respectivamente. Identificamos uma citotoxicidade concentração-dependente para as duas plantas testadas, independente do tempo. Sob as menores concentrações das plantas a viabilidade e a morfologia dos FGH foram preservadas. Dentro deste contexto, acreditamos na possibilidade de se utilizar essas plantas como terapia alternativa em diversas áreas de saúde, porém em concentrações biocompatíveis. / Studies have reported the antimicrobial activity of Equisetum giganteum and Punica granatum, reducing the risk of development of denture stomatitis, a disease mainly related to the colonization of prostheses by the fungus Candida albicans. In view of this, it is necessary that these plants be well tolerated by the oral tissues and, if possible, assist in the repair process. Objective: To carry out a phytochemical study of potentially active substances of E. giganteum and P. granatum and to evaluate the viability of human gingival fibroblasts against different concentrations of these two plants, after different periods in vitro. Material and Methods: After the identification of the plant compounds by HPLC-PAD, the fractions with the best antifungal activity against Candida albicans were selected. The crude extracts and selected fractions of P. granatum and E. giganteum were tested at different concentrations (0.23, 0.47, 0.94, 1.88, 3.75, 7.5, 15 and 30 mg) and periods (12, 24, 36 and 60 h) against human gingival fibroblasts (FGH), for the evaluation of their possible cytotoxicity through the analysis of the viability of FGH by the LIVE/DEAD assay. By means of this assay we quantitatively analyzed the cell viability through the readings of the relative units of fluorescence (URF) and qualitatively by analysis of the cellular morphology and density using inverted fluorescence microscopy, after three independent experiments. The parametric quantitative results were represented as mean and standard deviation (SD) with ANOVA-One-Way Variance analysis, followed by comparative analysis by the Tukey HSD test. The non-parametric quantitative results were presented as medians and quartiles and were submitted to the Kruskal-Wallis test, followed by comparative analysis by the Dunn test, according to normality tests (Kolmogorov-Smirnov test). Values of p <0.05 were indicative of statistical significance. Conclusions: Phenolic compounds, such as flavonoids and tannins, were identified in E. giganteum and P. granantum, respectively. We identified a concentration-dependent cytotoxicity for the two plants tested, regardless of the time. Under the lowest concentrations of plants the viability and morphology of FGH were preserved when compared to the control. Within this context, we believe in the possibility to use these plants as alternative therapy in several health areas, but in biocompatible concentrations.

Estudos relataram a atividade antimicrobina de Equisetum giganteum e Punica granatum, reduzindo o risco do desenvolvimento da estomatite protética, doença relacionada principalmente à colonização das próteses pelo fungo Candida albicans. Diante disso, é necessário que essas plantas sejam bem toleradas pelos tecidos bucais e, se possível, auxiliem no processo de reparo. Objetivo: Realizar um estudo fitoquímico de substâncias potencialmente ativas de Equisetum giganteum e Punica granatum e avaliar a viabilidade de fibroblastos gengivais humanos frente a diferentes concentrações destas plantas, após diferentes períodos in vitro. Material e Métodos: Após a identificação dos compostos das plantas por HPLC-PAD, foram selecionadas as frações com melhor atividade antifúngica perante Candida albicans. Os extratos brutos e frações selecionadas de P. granatum e E. giganteum foram testados em diferentes concentrações (0.23, 0.47, 0.94, 1.88, 3.75, 7.5, 15 e 30 mg) e períodos (12, 24, 36 e 60 h) sobre fibroblastos gengivais humanos (FGH), para a avaliação de suas citotoxicidades através da análise da viabilidade dos FGH, pelo ensaio LIVE/DEAD. Por meio desse ensaio, analisamos quantitativamente a viabilidade celular através das leituras das unidades relativas de fluorescência (URF) e qualitativamente por meio da analise da morfologia e da densidade observadas pela microscopia invertida de fluorescência, após três experimentos independentes para cada período de avaliação. Os resultados quantitativos paramétricos foram representados como média e desvio padrão (SD) com análise de Variância ANOVAOne- Way, seguida da análise comparativa pelo teste de Tukey HSD. Os resultados quantitativos não paramétricos foram apresentados como mediana e quartis e foram submetidos ao teste de Kruskal-Wallis, seguido de análise comparativa pelo teste de Dunn, de acordo com as análises de normalidade (Teste de Kolmogorov-Smirnov). Valores de p< 0.05 foram indicativos de significância estatística. Conclusões: Foram identificados compostos fenólicos, como flavonoides e taninos em E.giganteum e P. granantum, respectivamente. Identificamos uma citotoxicidade concentração-dependente para as duas plantas testadas, independente do tempo. Sob as menores concentrações das plantas a viabilidade e a morfologia dos FGH foram preservadas. Dentro deste contexto, acreditamos na possibilidade de se utilizar essas plantas como terapia alternativa em diversas áreas de saúde, porém em concentrações biocompatíveis. / Studies have reported the antimicrobial activity of Equisetum giganteum and Punica granatum, reducing the risk of development of denture stomatitis, a disease mainly related to the colonization of prostheses by the fungus Candida albicans. In view of this, it is necessary that these plants be well tolerated by the oral tissues and, if possible, assist in the repair process. Objective: To carry out a phytochemical study of potentially active substances of E. giganteum and P. granatum and to evaluate the viability of human gingival fibroblasts against different concentrations of these two plants, after different periods in vitro. Material and Methods: After the identification of the plant compounds by HPLC-PAD, the fractions with the best antifungal activity against Candida albicans were selected. The crude extracts and selected fractions of P. granatum and E. giganteum were tested at different concentrations (0.23, 0.47, 0.94, 1.88, 3.75, 7.5, 15 and 30 mg) and periods (12, 24, 36 and 60 h) against human gingival fibroblasts (FGH), for the evaluation of their possible cytotoxicity through the analysis of the viability of FGH by the LIVE/DEAD assay. By means of this assay we quantitatively analyzed the cell viability through the readings of the relative units of fluorescence (URF) and qualitatively by analysis of the cellular morphology and density using inverted fluorescence microscopy, after three independent experiments. The parametric quantitative results were represented as mean and standard deviation (SD) with ANOVA-One-Way Variance analysis, followed by comparative analysis by the Tukey HSD test. The non-parametric quantitative results were presented as medians and quartiles and were submitted to the Kruskal-Wallis test, followed by comparative analysis by the Dunn test, according to normality tests (Kolmogorov-Smirnov test). Values of p <0.05 were indicative of statistical significance. Conclusions: Phenolic compounds, such as flavonoids and tannins, were identified in E. giganteum and P. granantum, respectively. We identified a concentration-dependent cytotoxicity for the two plants tested, regardless of the time. Under the lowest concentrations of plants the viability and morphology of FGH were preserved when compared to the control. Within this context, we believe in the possibility to use these plants as alternative therapy in several health areas, but in biocompatible concentrations.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-06T21:04:37Z No. of bitstreams: 2 Dissertação - Danilo Maciel Carneiro - 2012.pdf: 736566 bytes, checksum: 660a01af596995a79647c05ae709a844 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-06T21:16:22Z (GMT) No. of bitstreams: 2 Dissertação - Danilo Maciel Carneiro - 2012.pdf: 736566 bytes, checksum: 660a01af596995a79647c05ae709a844 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-06T21:16:22Z (GMT). No. of bitstreams: 2 Dissertação - Danilo Maciel Carneiro - 2012.pdf: 736566 bytes, checksum: 660a01af596995a79647c05ae709a844 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2012-09-28 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Treatment with medicinal plants is described for centuries as part of traditional medicine and the interest for herbal products is growing consistently in present days. Equisetum arvense (horsetail) has a long traditional use in several countries and in Brazil its marketing is regulated. However, the existence of studies on its pharmacological effects and safety of use is questioned. The present study aims to combine to the traditional use and official regulations, new clinical data on the diuretic effect, safety and acute effects on kidney function of E. arvense. Primarily we preceded a literature review with searches by uniterm "Equisetum arvense" in the databases of PubMed, LILACS, SciELO, BVS, Cochrane, and Scopus. At the same time a double-blind randomized clinical trial randomly distributed 36 male healthy volunteers in 6 groups (n = 6), who have gone through a 3 stages treatment. Alternately for 4 days in a row, where given the drug tested, placebo or hydrochlorothiazide, separated by 10 days of wash out. The literature review showed that, despite of a well-documented traditional use and the regulation in some countries, studies on E. arvense are still incomplete for a well-established medical use, based on proven effectiveness and acceptable level of safety, necessitating more research mainly on the clinic area. In the clinical study, the extract of E. arvense demonstrated better acute diuretic effect than negative control and similar to hydrochlorothiazide (25 mg), without significant changes in elimination of electrolytes or urinary catabolites, and no signs of acute toxicity, hepatic, renal or cardiac. Further researches are needed to better clarification of the mechanism of action diuretic, as well as other possible pharmacological actions of this phytomedicine. / O tratamento com plantas medicinais é descrito há séculos como parte da medicina tradicional e o interesse em relação aos produtos fitoterápicos é crescente nos dias atuais. A Equisetum arvense (cavalinha) tem longa tradição de uso em vários países e, no Brasil, sua comercialização é regulamentada. Entretanto, há poucos estudos sobre os seus efeitos farmacológicos e segurança. O presente estudo visa contribuir com dados clínicos novos sobre o efeito diurético, segurança e ação na função renal da E. arvense. Inicialmente, procedeu-se uma revisão bibliográfica, de julho de 2011 a agosto de 2012, com buscas pelo unitermo “Equisetum arvense” nas bases de dados do PubMed, LILACS, SciELO, BVS, Cochrane e Scopus. Logo após, foi realizado um ensaio clínico duplo-cego randomizado com 36 voluntários sadios do sexo masculino, com idade entre 20 a 55 anos, alocados em 6 grupos (n=36) que passaram por 3 etapas de tratamento. Administrou-se alternadamente, por 4 dias seguidos, o extrato seco padronizado de Equisetum arvense, o placebo e a hidroclorotiazida, separados por 10 dias de wash out. A revisão bibliográfica revelou que, apesar do uso tradicional bem documentado e regulamentado em alguns países, os estudos sobre a E. arvense ainda são incompletos para o uso médico bem estabelecido, com base em eficácia comprovada e nível de segurança aceitável, necessitando de mais pesquisas principalmente na parte clínica. Contudo, no ensaio clínico, o extrato da E. arvense (900 mg/dia) demonstrou efeito diurético superior ao placebo e comparável à hidroclorotiazida (25 mg/dia), sem diferenças significativas nas taxas urinárias de eletrólitos ou de catabólitos e sem sinais de toxicidade aguda hepática, renal, hematológica ou cardíaca. Novas pesquisas são necessárias para melhor esclarecimento do mecanismo de ação diurética, bem como de outras possíveis ações farmacológicas deste fitomedicamento.

Adesivos protéticos inibem a inflamação da mucosa subjacente e podem receber, em sua composição, componentes antimicrobianos, reduzindo o risco do desenvolvimento da estomatite protética (EP), doença relacionada principalmente à colonização das próteses pelo fungo Candida albicans. Tem sido relatada a atividade antifúngica de fitoterápicos, podendo auxiliar no tratamento da EP. Objetivo: Realizar o estudo fitoquímico de substâncias potencialmente ativas de Equisetum giganteum (Eg) (Cavalinha) e de Punica granatum (Pg) (Romã) e avaliar in vitro se a incorporação de extratos hidroalcóolicos de Eg e de Pg a um adesivo protético (COREGA®) influencia no desenvolvimento do biofilme de C. albicans (SC5314) sobre a superfície de resina acrílica termopolimerizável (Lucitone 550). Material e Métodos: Após identificação dos compostos dos fitoterápicos por HPLC-PAD, foi selecionada a fração e a concentração de interesse por meio da concentração inibitória mínima (CIM). Os biofilmes foram induzidos durante 3, 6 ou 12 horas sobre a superfície de corpos de prova de resina acrílica, previamente submetidos ao tratamento com o adesivo associado aos fitoterápicos (AD/Eg ou AD/Pg). Como controles, corpos de prova foram tratados apenas com adesivo (AD), com a associação adesivo/nistatina (AD/Nt) ou não recebam tratamento (PBS). A atividade antimicrobiana foi avaliada por meio da quantificação do biofilme pela contagem de unidades formadoras de colônias por mililitro (UFC/mL) e pelo percentual de redução da atividade metabólica das células fúngicas pelo ensaio colorimétrico de redução de sais de tetrazólio XTT (2,3 Bis (2-Methoxy-4-Nitro-5-Sulfophenil) 5 - [(Phenyl-Amino) Carbonyl] 2H - Tetrazolium Hidroxide). Os resultados foram expressos como média ± desvio padrão, e submetidos ao teste de Kruskal-Wallis para UFC/mL e Mann-Whitney ou análise de variância ANOVA-2 fatores seguido do teste post-hoc de Tukey HSD e teste de Dunnett para XTT. As médias dos valores obtidos pelas duas metodologias (UFC/mL e XTT) foram submetidas ao teste de correlação de Spearman (&#x3B1;= 0,05). Resultados: Foi possível identificar, pela análise em HPLCPAD, compostos derivados de kaempferol e quercetina em Eg e derivados de elagitaninos, como punicalina, em Pg. A associação de ambos os fitoterápicos ao adesivo (AD/Eg ou AD/Pg) reduziram significativamente o biofilme sobre a superfície da resina, em comparação ao grupo AD. Considerando os corpos de prova tratados, o período inicial (3 horas) apresentou os melhores resultados em relação à inibição do crescimento fúngico, comparando-se com os outros períodos. Conclusão: Possivelmente, o potencial antimicrobiano de Eg e de Pg está associado a compostos como flavonoides e taninos, respectivamente. Por fim, é possível que a associação destes fitoterápicos ao adesivo protético COREGA® poderá constituir uma alternativa temporária, viável e inovadora para auxiliar no tratamento e/ou prevenção da EP, desde que a manutenção das propriedades inerentes deste adesivo seja comprovada após estudos posteriores. / Denture adhesives inhibit inflammation of the underlying mucosal tissue and can receive, in their composition, antimicrobial components, reducing the risk of development of denture stomatitis (DS), a disease related mainly to the colonization of the prosthesis by the fungus Candida albicans. It has been reported the antifungal activity of herbal medicines, which may help in the treatment of DS. Objective: To realize the phytochemical study of potentially active substances of Equisetum giganteum (Eg) (Cola de caballo) and Punica granatum Linne (Pg) (Pomegranate) and evaluate in vitro the incorporation of hydroalcoholic extracts of Eg and Pg to a denture adhesive (COREGA®) influences the development C. albicans biofilm (SC5314) on the surface a polymerized acrylic resin (Lucitone 550). Material and Methods: After identification of compounds of the herbal by HPLC-PAD, the fraction and the concentration were selected by minimum inhibitory concentration (MIC). Biofilms were induced for 3, 6 or 12 hours on the surface of acrylic resin specimens, previously subjected to treatment with the adhesive associated with herbal (AD/Eg or AD/Pg). As controls, samples were treated with adhesive (AD), adhesive/nystatin association (AD/Nt) or not received treatment (PBS). The antimicrobial activity was evaluated by quantifying the biofilm using counting colony forming units per milliliter (CFU/mL) and by reduction percentage of fungal metabolic activity using colorimetric assay XTT (2,3 Bis (2-Methoxy-4-Nitro-5-Sulfophenil) 5 - [(Phenyl-Amino) Carbonyl] 2H - Tetrazolium Hidroxide). The results were expressed as mean ± standard deviation, and subjected to Kruscal-Wallis test for CFU/mL and Mann-Whitney or 2-way analysis of variance (ANOVA) followed by Tukey\'s HSD post-hoc test and Dunnett test for XTT. The mean values obtained by the two methods (CFU/mL and XTT) were submitted to Spearman correlation test (&#x3B1;=0,05). Results: It was possible to identify, by the analysis on HPLC-PAD, compounds derived from kaempferol and quercetin in Eg and ellagitannins derivatives, as punicalin in Pg. The combination of both herbal medicines to the adhesive (AD/Eg or AD/Pg) significantly reduced the biofilm on the surface of the resin, compared to the AD group. Accordingly, there was an increase in the percentage of reduction of the metabolic activity of biofilm at all periods in the presence of herbal medicines. Considering the treated specimens, the initial period (3 hours) showed the best results in relation to inhibition of fungal growth compared with other periods. Conclusion: Possibly, the antimicrobial potential of E. giganteum and P. granatum is associated with compounds such as flavonoids and tannins, respectively. Finally, we suggest that the combination of these herbal medicines to COREGA® prosthetic adhesive may be a temporary, viable and innovative alternative to assist in the treatment and/or prevention of DS, since the maintenance of the inherent properties of this adhesive is proven after further studies.

Adesivos protéticos inibem a inflamação da mucosa subjacente e podem receber, em sua composição, componentes antimicrobianos, reduzindo o risco do desenvolvimento da estomatite protética (EP), doença relacionada principalmente à colonização das próteses pelo fungo Candida albicans. Tem sido relatada a atividade antifúngica de fitoterápicos, podendo auxiliar no tratamento da EP. Objetivo: Realizar o estudo fitoquímico de substâncias potencialmente ativas de Equisetum giganteum (Eg) (Cavalinha) e de Punica granatum (Pg) (Romã) e avaliar in vitro se a incorporação de extratos hidroalcóolicos de Eg e de Pg a um adesivo protético (COREGA®) influencia no desenvolvimento do biofilme de C. albicans (SC5314) sobre a superfície de resina acrílica termopolimerizável (Lucitone 550). Material e Métodos: Após identificação dos compostos dos fitoterápicos por HPLC-PAD, foi selecionada a fração e a concentração de interesse por meio da concentração inibitória mínima (CIM). Os biofilmes foram induzidos durante 3, 6 ou 12 horas sobre a superfície de corpos de prova de resina acrílica, previamente submetidos ao tratamento com o adesivo associado aos fitoterápicos (AD/Eg ou AD/Pg). Como controles, corpos de prova foram tratados apenas com adesivo (AD), com a associação adesivo/nistatina (AD/Nt) ou não recebam tratamento (PBS). A atividade antimicrobiana foi avaliada por meio da quantificação do biofilme pela contagem de unidades formadoras de colônias por mililitro (UFC/mL) e pelo percentual de redução da atividade metabólica das células fúngicas pelo ensaio colorimétrico de redução de sais de tetrazólio XTT (2,3 Bis (2-Methoxy-4-Nitro-5-Sulfophenil) 5 - [(Phenyl-Amino) Carbonyl] 2H - Tetrazolium Hidroxide). Os resultados foram expressos como média ± desvio padrão, e submetidos ao teste de Kruskal-Wallis para UFC/mL e Mann-Whitney ou análise de variância ANOVA-2 fatores seguido do teste post-hoc de Tukey HSD e teste de Dunnett para XTT. As médias dos valores obtidos pelas duas metodologias (UFC/mL e XTT) foram submetidas ao teste de correlação de Spearman (&#x3B1;= 0,05). Resultados: Foi possível identificar, pela análise em HPLCPAD, compostos derivados de kaempferol e quercetina em Eg e derivados de elagitaninos, como punicalina, em Pg. A associação de ambos os fitoterápicos ao adesivo (AD/Eg ou AD/Pg) reduziram significativamente o biofilme sobre a superfície da resina, em comparação ao grupo AD. Considerando os corpos de prova tratados, o período inicial (3 horas) apresentou os melhores resultados em relação à inibição do crescimento fúngico, comparando-se com os outros períodos. Conclusão: Possivelmente, o potencial antimicrobiano de Eg e de Pg está associado a compostos como flavonoides e taninos, respectivamente. Por fim, é possível que a associação destes fitoterápicos ao adesivo protético COREGA® poderá constituir uma alternativa temporária, viável e inovadora para auxiliar no tratamento e/ou prevenção da EP, desde que a manutenção das propriedades inerentes deste adesivo seja comprovada após estudos posteriores. / Denture adhesives inhibit inflammation of the underlying mucosal tissue and can receive, in their composition, antimicrobial components, reducing the risk of development of denture stomatitis (DS), a disease related mainly to the colonization of the prosthesis by the fungus Candida albicans. It has been reported the antifungal activity of herbal medicines, which may help in the treatment of DS. Objective: To realize the phytochemical study of potentially active substances of Equisetum giganteum (Eg) (Cola de caballo) and Punica granatum Linne (Pg) (Pomegranate) and evaluate in vitro the incorporation of hydroalcoholic extracts of Eg and Pg to a denture adhesive (COREGA®) influences the development C. albicans biofilm (SC5314) on the surface a polymerized acrylic resin (Lucitone 550). Material and Methods: After identification of compounds of the herbal by HPLC-PAD, the fraction and the concentration were selected by minimum inhibitory concentration (MIC). Biofilms were induced for 3, 6 or 12 hours on the surface of acrylic resin specimens, previously subjected to treatment with the adhesive associated with herbal (AD/Eg or AD/Pg). As controls, samples were treated with adhesive (AD), adhesive/nystatin association (AD/Nt) or not received treatment (PBS). The antimicrobial activity was evaluated by quantifying the biofilm using counting colony forming units per milliliter (CFU/mL) and by reduction percentage of fungal metabolic activity using colorimetric assay XTT (2,3 Bis (2-Methoxy-4-Nitro-5-Sulfophenil) 5 - [(Phenyl-Amino) Carbonyl] 2H - Tetrazolium Hidroxide). The results were expressed as mean ± standard deviation, and subjected to Kruscal-Wallis test for CFU/mL and Mann-Whitney or 2-way analysis of variance (ANOVA) followed by Tukey\'s HSD post-hoc test and Dunnett test for XTT. The mean values obtained by the two methods (CFU/mL and XTT) were submitted to Spearman correlation test (&#x3B1;=0,05). Results: It was possible to identify, by the analysis on HPLC-PAD, compounds derived from kaempferol and quercetin in Eg and ellagitannins derivatives, as punicalin in Pg. The combination of both herbal medicines to the adhesive (AD/Eg or AD/Pg) significantly reduced the biofilm on the surface of the resin, compared to the AD group. Accordingly, there was an increase in the percentage of reduction of the metabolic activity of biofilm at all periods in the presence of herbal medicines. Considering the treated specimens, the initial period (3 hours) showed the best results in relation to inhibition of fungal growth compared with other periods. Conclusion: Possibly, the antimicrobial potential of E. giganteum and P. granatum is associated with compounds such as flavonoids and tannins, respectively. Finally, we suggest that the combination of these herbal medicines to COREGA® prosthetic adhesive may be a temporary, viable and innovative alternative to assist in the treatment and/or prevention of DS, since the maintenance of the inherent properties of this adhesive is proven after further studies.

Equisetum spp. (horsetail / “Schachtelhalm”) is the only surviving genus of the primitive Sphenopsids vascular plants which reached their zenith during the Carboniferous era. It is an herbaceous plant and is distinguished by jointed stems with fused whorl of nodal leaves. The plant has been used for scouring kitchen utensils and polishing wood during the past time due to its high silica encrustations in the epidermis. Equisetum hyemale (scouring rush) can accumulate silica up to 16% dry weight in its tissue, which makes this plant an interesting candidate as a renewable resource of silica for the synthesis of biomorphous ceramics. The thesis comprises a comprehensive experimental study of silica accumulations in E.hyemale using different characterisation techniques at all hierarchical levels. The obtained results shed light on the local distribution, chemical form, crystallinity, and nanostructure of biogenic silica in E.hyemale which were quite unclear until now. Furthermore, isolation of biogenic silica from E.hyemale to obtain high grade mesoporous silica with high purity is investigated. Finally, syntheses of silicon carbide (b-SiC) by a direct thermoconversion process of E.hyemale is attempted, which is a promising material for high performance ceramics. It is found that silica is deposited continuously on the entire epidermal layer with the highest concentration on the knobs. The highest silicon content is at the knob tips (≈ 33%), followed by epidermal flank (≈ 17%), and inner lower knob (≈ 6%), whereas there is almost no silicon found in the interior parts. Raman spectroscopy reveals the presence of at least two silica modifications in E.hyemale. The first type is pure hydrated amorphous silica restricted to the knob tips. The second type is accumulated on the entire continuous outer layer adjacent to the epidermis cell walls. It is lacking silanol groups and is intimately associated with polysaccharides (cellulose, hemicellulose, pectin) and inorganic compounds. Silica deposited in E.hyemale is found to be mostly amorphous with almost negligible amounts of crystalline silica in the form of a-quartz (< 7%). The silica primary particles have a plate-like shape with a thickness of about 2 nm. Pure mesoporous amorphous silica with an open surface area up to 400 m2/g can be obtained from E.hyemale after leaching the plant with HCl to remove the inorganic impurities followed by a calcination treatment. The optimum calcination temperature appears to be around 500°C. Calcination of untreated E.hyemale causes a collapse of the biogenic silica structure which is mainly attributed to the detrimental action of alkali ions present in the native plant. Finally, pure b-SiC with a surface area of about 12 m2/g is obtained upon direct pyrolysis of HCl-treated E.hyemale samples in argon atmosphere. The original structure of native E.hyemale is substantially retained in the biomorphous b-SiC. The results of this thesis lead to a better understanding of the silicification process and allow to draw conclusions about the role of silica in E.hyemale. In particular, a templating role of the plant biopolymers for the synthesis of the nanostructured silica within the plant body can be deduced. Moreover, the high grade ultrafine amorphous silica isolated from E.hyemale promises applications as adsorbent and catalyst support and as silica source for the fabrication of silica-based composites. The synthesis of biomorphous b-SiC from sustainable and low-cost E.hyemale is still in its initial stage. The present thesis demonstrates the principal possibility of carbothermal synthesis of SiC from E.hyemale with the prospect of potential applications, for instance as refractory materials, catalyst supports, or high performance advanced ceramics. / Equisetum spp. (Schachtelhalm) ist die einzige überlebende Gattung der Schachtelhalmgewächse, die ihren Zenit während der Karbon Ära erreichten. Der Schachtelhalm ist eine krautartige Pflanze und wird durch verbundene Stämme mit fixiertem Wirtel der Knotenblätter unterschieden. Aufgrund seiner hohen Siliciumdioxid Bedeckung in der Epidermis sind Winterschachtelhalmen lange Zeit zur Reinigung von Küchegeräten und zum Polieren von Holz verwendet worden. Der Winterschachtelhalm (auch Scheuerkraut genannt) kann Siliciumdioxid bis zu 16% Trockengewicht in seinem Gewebe ansammeln. Dies macht aus dieser Pflanze einen interessanten Kandidaten als erneubare Ressource von Siliciumdioxid für die Synthese von biomorphen Keramiken. Die vorliegende Doktorarbeit beinhaltet eine ausführliche experimentelle Studie der Siliciumdioxidansammlungen in Winterschachtelhalmen mittels unterschiedlicher Charakterisierungstechniken auf allen hierarchischen Ebenen. Die Ergebnisse der Arbeit werfen neues Licht auf die lokale Verteilung, die chemischen Form, die Kristallinität und die Nanostruktur des biogenen Siliciumdioxids, die bisher ziemlich unklar waren. Außerdem werden Möglichkeiten zur Isolierung des biogenen Siliciumdioxids aus Winterschachtelhalmen untersucht, um hochgradig reines Siliciumdioxid zu erhalten. Auch wird die direkte carbothermale Synthese von Siliciumkarbid (b-SiC) aus Schachtelhalmen untersucht, mit dem Ziel einer kostengünstigen Herstellung von Hochleistungskeramiken aus nachwachsenden Rohstoffen Es wird gezeigt, dass das Siliciumdioxid in einer kontinuierlichen Schicht in der Epidermis vorliegt, mit der höchsten Siliciumkonzentration in den auffälligen knopfartigen Ausbuchtungen. Den höchsten Siliciumgehalt zeigen die Knopfspitzen (≈ 33%), gefolgt von der epidermalen Flanke (≈ 17%) und inneren unteren Teile der Knöpfe (≈ 6%), während es in den inneren Teilen der Pflanze praktisch kein Silicium gibt. Ramanspektroskopie beweist eindeutig, dass mindestens zwei Siliciumdioxid Modifikationen vorhanden sind. Der erste Typ ist reines hydratisiertes amorphes Siliciumdioxid, das auf den Bereich der Knopfspitzen beschränkt ist. Der zweite Typ wird in der gesamten kontinuierlichen äußeren Schicht angesammelt, weist keine Ramanbanden von Silanolgruppen auf, und ist örtlich eng verknüpft mit Banden von Polysacchariden (Zellulose, Hemizellulose, Pektin) sowie anorganischen Verbindungen. Der Großteil des Siliciumdioxids in Winterschachtelhalmen ist amorph mit unwesentlichen Mengen an kristallinem a-Quarz (< 7%). Die primären Siliciumdioxidpartikel haben eine plattenähnliche Form mit einer Dicke von ungefähr 2 nm. Hochreines mesoporöses amorphes Siliciumdioxid mit offener Porosität und innerer Oberfläche bis zu 400 m2/g kann aus Winterschachtelhalmen isoliert werden. Dies wird erreicht indem man die Pflanze mit Salzsäure behandelt um die anorganischen Verunreinigungen zu entfernen, gefolgt von einer Kalzinierung, wobei die optimale Temperatur bei etwa 500°C liegt. Im Gegensatz zu den chemisch vorbehandelten Schachtelhalmen, verursacht die Kalzinierung von unbehandelten Winterschachtelhalmen einen Kollaps der biogenen Siliciumdioxidstruktur, und es werden nur sehr kleine innere Oberflächen erzielt. Dies wird hauptsächlich dem Einfluss der Alkaliionen zugeschrieben die in der unbehandelten Pflanze vorhanden sind. Es wird schließlich gezeigt, dass durch direkte Pyrolyse der HCl-behandelten Winterschachtelhalme in Argonatmosphäre reines b-SiC mit einer Oberfläche von ungefähr 12 m2/g erzeugt werden kann. Die ursprüngliche Struktur von natürlichen Winterschachtelhalmen bleibt dabei im Wesentlichen im biomorphen b-SiC erhalten. Die Ergebnisse dieser Arbeit führen zu einem besseren Verständnis des Silicifizierungsprozesses und erlauben es auch, Aussagen über die mögliche Rolle von Siliciumdioxid in E.hyemale zu treffen. Insbesondere kann den Pflanzenpolymeren die Rolle eines Templates bei der Synthese des biogenen Siliciumdioxids im Pflanzengewebe zugeschrieben werden. Das aus den Pflanzen isolierte ultrafeine amorphe Siliciumdioxid mit hoher Reinheit verspricht potentielle Anwendungen, z.B. als Adsorbent oder Katalysatorsupport, und auch als Füllmaterial für die Herstellung von Komopositmaterialien. Die Synthese von biomorphem b-SiC aus erneubaren und preiswerten Winterschachtelhalmen steht zwar erst am Anfang, jedoch konnte die vorliegende Arbeit die prinzipielle Machbarkeit aufzeigen. Dieses Material scheint sehr vielversprechend für eine Reihe technischer Anwendung, zum Beispiel als Refraktärmaterial, Katalysatorsupport oder neuartige Hochleistungskeramik.

Plants (macrophytes) growing in lake and wetland sediments are known mediators of greenhouse gases (GHG), specifically methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O). Current studies have emphasized the potential risk of underestimation regarding emissions of plant-mediated GHGs from terrestrial systems including lakes, streams and other freshwater bodies. In order to differentiate the possible sources and sinks of atmospheric carbon and nitrogen in aquatic environments, this study aims to investigate the spatial variability of GHG fluxes in stands of common wetland macrophytes. Field samplings were carried out in the summer of 2012 where 24-hour diel measurements were conducted with the static chamber method in a boreal lake in south western Sweden. Two macrophyte communities were studied; one mixed-species stand and one species-specific stand of water horsetail (Equisetum fluviatile). Spatial variability was confirmed at several stages, both between and within stands. The species-specific stand emitted more CH4 than the mixed stand, from 0.17 to 8.99 mmol m-2 h-1, compared to 0.63 – 1.95 mmol m-2 h-1 maximum measured. Within stand variability was confirmed as variable CH4 flux per strand of E. fluviatile was established. No significant differences were observed regarding CO2 and N2O, other than weak correlation in diel patterns, e.g. daytime uptake and night time respiration/emission for both gases.

Le silicium (Si) est un élément ubiquiste et abondant dans l’environnement. L'absorption de Si par les plantes leur confère une résistance accrue à différents stress. Il y a une corrélation positive entre les effets bénéfiques observés et la quantité de Si absorbée via des transporteurs racinaires. Deux groupes de transporteurs d’influx et d’efflux ont été identifiés récemment dans les racines de certaines plantes supérieures. Afin de mieux utiliser le potentiel du Si, il est essentiel d’élargir le spectre des espèces végétales étudiées. Cette thèse utilise comme modèle une plante primitive fortement accumulatrice de Si : la prêle des champs (Equisetum arvense). L’objectif principal des travaux était d’identifier et de caractériser les transporteurs de Si de la prêle. Une approche utilisant le séquençage du transcriptome racinaire de la prêle a d’abord permis d’identifier chez cette plante une famille multigénique de transporteurs d’influx de Si : des aquaporines du sous-groupe des NIP. Une analyse phylogénétique ainsi qu’une comparaison des domaines fonctionnels ont permis de découvrir que les transporteurs de prêle appartiennent à un groupe de transporteurs distinct de celui des plantes supérieures. Les NIP de prêle ont un pore STAR, versus le pore GSGR commun à tous les autres transporteurs d’influx de Si. Afin d’en déterminer la fonction, les protéines de prêle ont été exprimées de façon hétérologue dans des ovocytes de Xenopus et chez Arabidopsis. Les résultats démontrent un influx élevé de Si. Les travaux ont ensuite permis d’identifier deux transporteurs Lsi2 d’efflux de Si chez la prêle, partageant une faible identité avec leurs homologues des plantes supérieures. Afin d’en déterminer la fonction, un des Lsi2 de prêle a également subi une expression hétérologue dans des ovocytes de Xenopus, confirmant qu’il s’agit d’un transporteur d’efflux de Si. Il est probable que l’absorption élevée de Si par la prêle soit due à l’abondance du nombre de gènes codant pour des transporteurs d’influx et d’efflux, mais aussi par l’activité spécifique élevée de ces transporteurs. Les travaux sur les transporteurs de Si chez la prêle permettent une comparaison entre les plantes primitives et les plantes agricoles modernes, afin d’optimiser l’usage du Si contre les stress. / Silicon (Si) is an abundant element in the environment. Plants benefit greatly from Si absorption, which results in increased resistance to stresses. There appears to be a link between high Si absorption via specific transporters, and the beneficial effects linked to this element. Recently, two groups of Si influx and efflux transporter were identified in the roots of Si-accumulating higher plants. Horsetail (Equisetum arvense) is a primitive plant and one of the strongest Si accumulators in the plant kingdom. The main objective of this thesis was to identify and characterize horsetail Si transporters. By sequencing the horsetail root transcriptome, we identified a multigene family of aquaporin Si influx transporters: aquaporins of the subgroup NIP. Comparison of known functional domains and phylogenetic analysis of sequences revealed that the horsetail proteins belong to a different group than higher-plant Si transporters. The horsetail proteins contain a STAR pore as opposed to the GSGR pore common to all previously identified Si influx transporters. In order to determine its functionality, the proteins were heterologously expressed in both Xenopus oocytes and Arabidopsis, and the results showed high Si influx activity. We also identified in horsetail two homologues of Lsi2 Si efflux transporters that share low sequence identity with their higher plant homologues. In order to determine its functionality, one of the horsetail Lsi2 was heterologously expressed in Xenopus oocytes, confirming its Si efflux activity. Overall, high Si accumulation by horsetail may be linked to the number of Si influx and efflux transporter, but also to their high transport activity. These findings on horsetail Si transporters allow a comparison between primitive plants and agronomic species, to optimize the use of Si against stresses.