Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The present study employed a two-phased approach to investigate the possible mechanisms involved in the chemopreventive properties of rooibos (Aspalathus linearis) and different honeybush species (Cyclopia spp.) in vitro. In the first phase, the effect of unfermented methanol and aqueous herbal tea extracts against the growth parameters (cell viability, proliferation and apoptosis) of normal (CRL 7761); premalignant (HaCaT); and malignant (CRL 7762) skin cells was evaluated and compared to green tea extracts. The predictive potential of polyphenol content (total polyphenol and flavanol/proanthocyanidins) and antioxidant properties (ABTS; ORAC; FRAP and LPO) in the biological activity of extracts in cells was also assessed. Of the herbal teas, the methanol extract of rooibos was the most active and it inhibited the growth of skin cells presumably by inducing mitochondrial dysfunction via membrane depolarisation. At lower concentrations, this activity was associated with inhibition of cell proliferation that was selective for cancer cells whilst higher concentrations induced apoptosis that was more prominent in premalignant cells. The strong antioxidant properties of the extracts implicated the role of pro-oxidative polyphenol/iron interactions involving monomeric flavonoids and polymeric proanthocyanidins in the cytotoxic effects of rooibos. The strong relationship between total polyphenolic and flavanol/proanthocyanidins content, antioxidant properties and reduction of cell viability indicated that these parameters (polyphenols and antioxidant properties) can serve as predictive tools for the cytotoxic effects of rooibos in vitro. The aqueous extracts of honeybush species, although weaker, displayed similar effects to rooibos extracts in cells with C. genistoides being the most effective at selectively inhibiting the proliferation of cancer cells whilst the pro-apoptotic activity of C. subternata and C. intermedia was more prominent in premalignant cells. The underlying mechanisms are also likely to result from pro-oxidative mechanisms resulting from polyphenol/iron interactions that mainly involve polymeric flavanol-like proanthocyanidin compounds in honeybush. In contrast, the methanol extracts exhibited weaker cytotoxic effects and protected cancer cells from going into apoptosis. The cytoprotective effects of honeybush species are possibly mediated by the major monomeric compounds such as mangiferin and hesperidin through antioxidant mechanisms that result in reduction of oxidative stress. Due to the possible dual role of the monomeric and polymeric compounds in the honeybush extracts, the total polyphenolic content of these herbal teas may not be a good indicator of biological activity in vitro. However, as aqueous extracts displayed high flavanol/proanthocyanidins content and exceptional activity in the ABTS assay, these parameters may be considered as indicators of cytotoxicity. On the other hand, methanol extracts, particularly from the xanthone-rich species (C. genistoides and C. longifolia) which exhibited the weakest cytotoxic effects, were more active in the ORAC thus this assay may be a useful predictor for cytoprotective activity. In the second phase, an in vitro UVB/HaCaT model which used IL-1α as a biomarker for early inflammation was developed and validated with known anti-inflammatory compounds, dexamethasone and ibuprofen. It was used to determine the specific mechanisms involved in the modulatory effects of the herbal tea extracts against inflammation. Rooibos extracts and the aqueous extract of honeybush enhanced the cytotoxic effects of UVB in the model and exhibited indirect anti-inflammatory effects as they removed icIL-1α containing cells via apoptosis. In contrast, methanol extracts of honeybush exacerbated icIL-1α by protecting UVB stimulated cells from undergoing apoptosis. In conclusion, methanol extract of rooibos and aqueous extracts of honeybush species may be useful in protecting the skin after UVB exposure. These herbal tea extracts may block initiation and delay the promotion stage during skin carcinogenesis by removing premalignant cells via apoptosis and preventing onset of inflammation. In contrast, due to their cytoprotective effects, methanol extracts of honeybush may be more effective at preventing oxidative stress in skin before UVB exposure. Future studies should focus on the effects of extracts and polyphenolic fractions on the oxidative status of the cells and development of biomarkers of chemoprevention that can be utilised in vivo and in human skin. / AFRIKAANSE OPSOMMING: In hierdie studie word moontlike velkankerwerende eienskappe van rooibos (Aspalathus linearis) en ‘n aantal heuningbos (Cyclopia spp.) spesies deur twee afsonderlike benaderings bestudeer. Die eerste benadering ondersoek die effek van die kruietee op groeiparameters van velselle [lewensvatbaarheid, groei en dood van normale selle (CRL 7761), vroeë kankerselle (HaCaT) en kankerselle (CRL 7762)]. Tydens eksperimente is die moontlikheid om polifenoolinhoud (totale polifenole, en flavanol/proantosianidiene verhouding) en antioksidant-eienskappe te gebruik om die biologiese funksies van die ekstrakte in die selle te voorspel, geevalueer. Die metanolekstrak van rooibos het die groei van selle die effektiefste gestop, moontlik deur depolarisasie van die mitokondriale membraan. By lae konsentrasies van die ekstrak is die groei van kankerselle selektief gestop, terwyl vroeë kankerselle die sensitiefste by hoër konsentrasies was. Die hoë antioksidant-aktiwiteit van die rooibosekstrak kan moontlik ‘n rol speel in die indusering van sitotoksiese effekte in die selle en kan toegeskryf word aan die pro-antioksidant aktiwiteit van die polifenole weens hul interaksie met yster. ‘n Spesifieke funksie word vir die monomeriese flavonoïede en die polimeriese proantosianidiene geïmpliseer. Die sterk verwantskap tussen die totale polifenoolinhoud, flavanol/proantosianidien inhoud en antioksidant aktiwiteit met die verlaging in selgroei, maak hul relevante parameters van die voorspellingsmodel. Die waterekstrakte van heuningbos induseer ook soortgelyke maar swakker effekte met die induksie van kankersel dood, met C. genistoides die selektiefste en C. subternata en C. intermedia die aktiefste spesies wat die groei van die vroeë kanker selle inhibeer. Die onderliggende meganismes betrokke blyk ook aan ‘n pro-oksidant effek toe geskryf te wees, waartydens spesifieke polifenool/yster interaksies betrokke is. In teenstelling met rooibos, beskerm die metanolekstrak van heuningbos kankerselle teen seldood, wat moontlik verband hou met die antioksidant-eienskappe van die hoof monomeriese polifenole, mangiferien/isomangiferien en hesperidien. Vanweë die dubbele rol van die monomeriese polifenole en polimeriese verbindings in heuninghbosekstrakte is die totale polifenol inhoud nie ‘n goeie indikator van die biologiese aktiwiteit in vitro nie. Daarenteen is die flavanol/proantosianien inhoud en die hoë aktiwiteit in die ABTS antioksidanttoets goeie indikators om seldood te voorspel. In teenstelling hiermee het die metanolekstrakte van die xantoon-ryke spesies (C. genistoides en C. longifolia) ‘n baie lae effek op seldood, maar ‘n hoë aktiwitiet in die ORAC toets getoon, wat ‘n goeie rigtingwyser is om die beskermende effek in selle te voorspel. Met die tweede benadering is die anti-inflammatoriese eienskappe en die onderliggende meganismes van die kruietee ondersoek in ‘n UVB/HaCaT selmodel. Intrasellulêre interleukin 1α (IL-1α) is as merker gebruik en die model is geëvalueer deur bekende anti-inflammatoriese verbindings soos dexamethasone en ibuprofin te gebruik. Die metanolekstrak van rooibos en die waterekstrak van heuningbos het die toksiese effek van UVB in die model verhoog deur selle met verhoogde vlakke,van icIL-1α te verwyder deur middel van die induksie van seldood. Die metanolekstrak beskerm die selle teen die oksidatiewe skade wat deur UVB geïnduseer word en verwyder nie selle met hoë IL-1α vlakke nie. Ter opsomming blyk dit dat die metanolekstrak van rooibos en die waterekstrak van heuningbos moontlik gebuik kan word om die vel te beskerm teen die induksie van icIL-1α en sodoende die inisiëring van kanker te blokkeer en ook die promosie van kanker te vertraag. Die beskermende effek van die metanolekstrak kan moontlik aangewend word om die oksidatiewe skade wat deur UVB veroorsaak word teen te werk deur dit aan te wend voordat blootstelling plaasvind. Toekomstige studies behoort verdere karakterisering van die polifenoolsamestelling van die ekstrakte in te sluit en hul effek op die oksidatiewe status en anti-inflammoriese effekte van selle te bepaal ten einde sekere merkers te identifiseer vir vel studies in vivo.

<p>In South Africa, the crude aqueous extract from Hypoxis hemerocallidea is used by AIDS patients to treat opportunistic infections, such as tuberculosis. The rapid emergence of multidrug-resistant tuberculosis, and extreme drug resistant tuberculosis, in recent years, is a major threat to human health. The treatment of TB, nosocomial bacterial infections, and fungal infections is now a clinical challenge, especially in the immuno-compromised individual. There is a dire need for novel antibiotic alternatives with phytotherapies and plant-derived compounds as potentially promising alternatives. The main objective of this study was to investigate the antimycobacterial activity of Hypoxis hemerocallidea, a South African medicinal plant, using Mycobacterium smegmatis.</p>

<p>Early man dabbled with the use of plant extracts to cure ailments. This practice has been passed down from generation to generation and today more than 50% of the world'sdrugs are natural products or derivatives thereof. Scientists have thus established a branch of research called natural product research. This branch of research involves the identification and purification of secondary metabolites with a specific biological activity. The methodology involves the screening of plant products for a specific biological activity, purification of the biologically active natural product by separation technology and structure determination. The biologically active natural products is then further scrutinized to serve as a novel drug or lead compound for the development of a novel drug. This research exploited this research methodology.</p>

Ganoderma lucidum is a popular herbal medicine used in China to promote health. Modern studies have disclosed that the active ingredients of Ganoderma can exhibit several effects, including antitumor effects and immunomodulation. The present study evaluated the antitumor effects of self-prepared Ganoderma extracts and spores oil, and investigated the possible underlying mechanisms by observing the effects of the extracts and oil on topoisomerases and the cell cycle. The results showed that Ganoderma extracts and spores oil presented dose-dependent inhibitory effects on tumor cells. The half maximal inhibitory concentration (IC50) values of Ganoderma extracts on HL60, K562 and SGC-7901 cells for 24 h were 0.44, 0.39 and 0.90 mg/ml, respectively; for Ganoderma spores oil, the IC50 values were 1.13, 2.27 and 6.29 mg/ml, respectively. In the in vivo study, the inhibitory rates of Ganoderma extracts (4 g/kg/d, intragastrically) on S180 and H22 cells were 39.1 and 44.6%, respectively, and for Ganoderma spores oil (1.2 g/kg/d, intragastrically) the inhibitory rates were 30.9 and 44.9%, respectively. Ganoderma extracts and spores oil inhibited the activities of topoisomerase I and II. Ganoderma spores oil was shown block the cell cycle at the transition between the G1 and S phases and induce a marked decrease in cyclin D1 levels in K562 cells, with no significant change in cyclin E level. These results suggest that the Ganoderma extracts and spores oil possessed antitumor effects in the in vitro and in vivo studies. The antitumor mechanisms of the extracts and spores oil were associated with inhibitory effects on topoisomerase I and II activities, and for Ganoderma spores oil, the antitumor effects may also be associated with decreased cyclin D1 levels, thus inducing G1 arrest in the cell cycle.

This study was undertaken in order to determine whether the extracts of common garden vegetables could be incorporated into simple, economical culture media which might be used for the growth and cultivation of at least some of the more commonly used microorganisms.

A presença de 14 compostos fenólicos (ácido elágico, ácido gálico, vanilina, siringaldeído, sinapaldeído, coniferaldeído, ácido vanílico , siríngico ácido, a quercetina, trans-resveratrol, catequina, epicatequina, eugenol, e miricetina) e duas cumarinas (escopoletina e cumarina) foi investigada por HPLC-ESI-MSn em um total de 25 extratos de aguardente de seis diferentes madeiras brasileiras e o carvalho, comumente utilizados pela indústria de tanoaria para o envelhecimento da cachaça. Estes dados foram comparados com os anteriormente obtidos utilizando HPLC-DAD-Fluorescência. Questões pendentes relativas à atribuição da epicatequina, co-eluições do ácido gálico e do ácido elagico respectivamente foram resolvidas utilizando HPLC-ESI-MSn. Além disso, elaborou-se uma impressão digital cromatográfica de HPLC-DAD usando a análise quimiométrica (PCA) com base nos perfis de eluição cromatográfica dos extratos monitorizada a 280 nm. As principais diferenças observadas entre o carvalho e as madeiras brasileiras reside nas concentrações de cumarina, catequina, siringaldeído, e coniferaldeído. A análise quimiometrica do perfil do quantitativo dos 14 compostos fenólicos e das duas cumarinas nos extractos de madeira permitiu uma boa diferenciação entre os extratos das madeiras brasileiras e os extratos de carvalho. A impressão digital cromatográfica analisada por PCA revelou diferenças significativas entre as madeiras brasileiras e o carvalho, definindo claramente seis grupos de extratos de madeira: (i) extratos de carvalho, extratos (ii) de jatobá, (iii) cabreúva- parda extratos, (iv) os extratos de amendoim (v) canela-sassafrás e extratos (vi) de pequi. As análises multivariadas de UV-Vis de dados espectrais de 93 extratos de cachaça ,de madeiras brasileiras e de carvalho, forneceu um modelo simples e robusto para classificar cachaças brasileiras de acordo com as espécies de madeira utilizados nos barris de maturação. Aplicação de PCA (Análise de Componentes Principais) e HCA (análise hierárquica de agrupamentos) levou a identificação de 7 agrupamentos; amburana, amendoim, balsamo, castanheira, jatobá, jequitibá e carvalho. A aplicaçao de LDA (Análise Discriminante Linear) aos resultados experimentais permitiu a classificação de 10 diferentes espécies de madeira utilizadas nos extratos de cachaça ;amburana, amendoim, balsamo, cabreúva-parda, canela sassafrás, castanheira, jatobá, jequitibá-rosa, louro-canela, e carvalho, com uma precisão variando de 80% (amendoim e Castanheira) a 100% (bálsamo e jequitibá-rosa). A auto consistência do modelo foi verificada usando 50 amostras de cachaças comerciais. Um índice de classificação muito bom foi observado para este modelo, cuja atribuiçao correta variou de 100% a 80 %. A metodologia aqui desenvolvida (UV-vis) fornece uma alternativa de baixo custo e robusta a cromatografia líquida e a espectrometria de massa para identificar as diferentes espécies de madeira utilizadas nas construções dos barris em que destilados foram armazenados. Além disso, ela contém potencial como uma possível ferramenta forense para a identificação de madeiras objetivando controlar a extração de espécies em risco. Estes desenvolvimentos poderao ser ampliados para outros destilados e para uma maior variedade de espécies de madeira. / A total of 25 sugarcane spirit extracts of six different Brazilian woods and oak, commonly used by cooperage industries for aging cachaça, were analyzed for the presence of 14 phenolic compounds (ellagic acid, gallic acid, vanillin, syringaldehyde, synapaldehyde, coniferaldehyde, vanillic acid, syringic acid, quercetin, trans-resveratrol, catechin, epicatechin, eugenol, and myricetin) and two coumarins (scopoletin and coumarin) by HPLC-ESI-MSn . This data was compared with the previous one obtained from HPLC-DAD-Fluorescence. Pending questions regarding to epicatechin attribution, galic acid and elagic acid co-elution have been solved through HPLC-ESI-MSn analysis. Furthermore, an HPLC-DAD chromatographic fingerprint was build-up using chemometric analysis based on the chromatographic elution profiles of the extracts monitored at 280?nm. The main difference observed among oak and Brazilian woods remains in the concentration of coumarin, catechin, syringaldehyde, and coniferaldehyde. The chemometric analysis of the quantitative profile of the 14 phenolic compounds and two coumarins in the wood extracts provides a good differentiation between the Brazilian wood and oak extracts. The chromatographic fingerprint treated by multivariate analysis revealed significant differences among Brazilian woods themselves and oak, clearly defining six groups of wood extracts: (i) oak extracts, (ii) jatobá extracts, (iii) cabreúva-parda extracts, (iv) amendoim extracts, (v) canela-sassafrás extracts and (vi) pequi extracts.<br /> Multivariate analyses of UV-Vis spectral data from 93 cachaça wood extracts provide a simple and robust model to classify aged Brazilian cachacas according to the wood species used in the maturation barrels. Application of PCA (Principal Components Analysis) and HCA (Hierarchical Cluster Analysis) leads to identification of 7 clusters of cachaca\'s wood extracts (amburana, amendoim, balsamo, castanheira, jatoba, jequitibá and oak). LDA (Linear Discriminant Analysis) affords classification of 10 different wood species used in the cachaça extracts (amburana, amendoim, balsamo, cabreuva-parda, canela-sassafras, castanheira, jatobá, jequitiba-rosa, louro-canela, and oak) with an accuracy ranging from 80% (amendoim and castanheira) to 100% (bálsamo and jequitibá-rosa).This model self consistency was checked using 50 samples of commercial cachaças. A very good classification was observed for this model, which 100 to 80% of correct assignment.<br /> The methodology provides a robust low-cost alternative to methods based on liquid chromatography and mass spectrometry to classify cachaças aged in barrels that are composed of different wood species. Furthermore, it holds some potential as a possible forensic tool for wood identification which could be applied to control the wood marked of endangered species. Our findings could be extended to other spirits and to a wider variety of wood species.

O mercado de produtos cosméticos, especialmente aqueles que têm na sua composição constituintes naturais, está em franca expansão. Uma das razões desta expansão é que os extratos vegetais têm eficácia na proteção contra os efeitos da exposição solar, sendo que o mecanismo de ação envolve principalmente o efeito antioxidante, diminuindo ou inibindo os danos gerados pelos radicais livres e/ou por outros compostos oxidantes. Este efeito protetor dos extratos vegetais tem motivado o interesse das indústrias do ramo, especialmente no entendimento dos mecanismos de dano e proteção. Além do efeito antioxidante, demonstrou-se recentemente que compostos vegetais podem também exercer efeito protetor através da proteção de membranas. No entanto, a relação entre a capacidade antioxidante desses compostos e a eficiência de proteção de membranas ainda não foi estabelecida. Neste trabalho, pretende-se quantificar a eficácia relativa dos extratos vegetais em termos de proteção de membranas. / The market of cosmetics, especially those who have in their composition natural constituents, is booming. One reason for this increase is that the plant extracts are effective in protecting against the effects of solar exposure, and the mechanism of action involves mainly the antioxidant effect, decreasing or inhibiting the damage caused by free radicals and / or other oxidizing compounds. This protective effect of plant extracts has motivated the interest of the sector industries, especially in the understanding of the mechanisms of injury and protection. In addition to the antioxidant effect, it was demonstrated recently that plant compounds may also exert a protective effect by the protective membrane. However, the relationship between the antioxidant capacity of these compounds and membranes protecting efficiency has not been established. In this work, it is intended to quantify the relative efficacy of the plant extracts in terms of membrane protection.

Estudos da atividade biológica de produtos naturais visando suas aplicações no controle de microrganismos são estratégicos e de fundamental importância econômica e social. Considerando o grande potencial da biodiversidade brasileira, o objetivo deste trabalho foi avaliar a atividade antimicrobiana do xilitol e dos extratos brutos obtidos das folhas das plantas Eugenia uniflora, Psidum guajava, Punica granatum e Syzygium cumini, bem como da associação entre os extratos e entre o xilitol e os extratos. Os extratos foram obtidos de folhas frescas maceradas em uma solução de etanol 95%, filtrada após 72 horas e concentrada em evaporador rotatório sob pressão reduzida. Foi realizada a técnica de macrodiluição em caldo e o crescimento das bactérias Staphylococcus aureus (ATCC 25923) e Escherichia coli (ATCC 25922) foi verificado pela leitura da absorbância dos tubos. O crescimento bacteriano normal foi considerado como 100%. A porcentagem de inibição sobre o crescimento bacteriano foi calculada subtraindo-se de 100% a porcentagem de crescimento na presença do extrato, xilitol ou associações. Todos os extratos inibiram o crescimento bacteriano, no entanto a atividade sobre a bactéria E. coli foi inferior aquela obtida para a bactéria S. aureus. Nos ensaios na presença de xilitol apenas a bactéria S. aureus teve seu crescimento inibido. As associações entre os extratos das folhas das espécies E. uniflora e P. guajava e das espécies E. uniflora e P. granatum promoveram inibições superiores e em concentrações menores sobre o crescimento da bactéria S. aureus quando comparadas com as inibições promovidas pelos extratos isolados, indicando um efeito antimicrobiano sinérgico entre estes extratos. As associações entre o xilitol e os extratos das folhas das espécies E. uniflora ou S. cumini e entre o xilitol e os extratos das folhas das espécies P. guajava ou P. granatum apresentaram um efeito antimicrobiano sinérgico sobre as bactérias S. aureus e E. coli, respectivamente. Os resultados do presente estudo contribuem na busca de novas alternativas terapêuticas antimicrobianas, uma vez que pode servir de subsídio para novos estudos químicos e farmacológicos a partir de fontes naturais brasileiras. / Biological activities studies of natural products aiming their applications in microorganisms control are strategic, economic, and socially important. Considering the Brazilian biodiversity&#8223;s large potential, the purpose of this work was to evaluate antimicrobial activity of xylitol and of crude extracts obtained from leaves of the following plants: Eugenia uniflora, Psidum guajava, Punica granatum and Syzygium cumini, as well as from the association of the extracts and of xylitol with the extracts. The extracts were obtained from fresh leaves macerated in a 95% ethanol solution, filtered after 72 hours and concentrated in spinning evaporator under reduced pressure. The broth macrodilution technique was used and growth of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) bacteria was observed upon reading of pipes absorption. Regular bacterial growth was considered as 100%. The percentage of inhibition over bacterial growth was calculated by subtracting from 100%, the growth percentage in the presence of the essence, xylitol or associations. All extracts inhibited bacterial growth, but the activity on E. coli bacteria was inferior to the one obtained for S. aureus bacteria. In tests in the presence of xyliol only the S. aureus bacteria had its growth inhibited. Associations between the extracts from leaves of the species E. uniflora and P. guajava and the species E. uniflora and P. granatum promoted superior inhibitions and in inferior concentrations over the growth of S. aureus bacteria in comparison to inhibitions promoted by isolated extracts, indicating a synergetic antimicrobial effect between these extracts. The associations between xylitol and the extracts of E. uniflora or S. cumini species and between xylitol and the extracts from leaves of the species P. guajava or P. granatum presented a synergetic antimicrobial effect over the S. aureus and E. coli bacteria, respectively. The results of the present study contribute in the search of antimicrobial therapeutic alternatives, once it can be used as base for new chemical and pharmacological studies from Brazilian natural sources.

Foram desenvolvidos cinco experimentos com o objetivo de avaliar o efeito do fornecimento de óleos essenciais sobre a fermentação ruminal e a digestibilidade dos nutrientes em borregos. No experimento I, avaliou-se um produto comercial tendo como princípio ativo óleo essencial de pimenta (Activo&reg;), os tratamentos experimentais foram: controle negativo ração base (30% de volumoso e 70% de concentrado, % da MS); controle positivo - ração base adicionada com 25 mg de monensina sódica por kg de matéria natural e ração base adicionada com 100, 200 ou 300 ppm de Activo&reg; (%MS). Nos quatro experimentos restantes, além dos tratamentos controle negativo e controle positivo descritos para o primeiro experimento, avaliou-se também a inclusão na dieta de 1,09; 2,18 ou 3,27 mL/kg de matéria seca (MS) de óleo essencial extraído do capim cidreira, Cymbopogon citratus (Experimento II); Óleo essencial extraído do fruto da aroeira-vermelha, Schinus terebinthifolius (Experimento III); Óleo essencial extraído do capim limão, Cymbopogon flexuosus (Experimento IV) ou óleo essencial extraído das folhas da aroeira vermelha; Schinus terebinthifolius (Experimento V). No experimento I, não houve efeito dos tratamentos sobre a concentração ruminal de ácidos graxos de cadeia curta (AGCC). No entanto, quando comparados ao controle positivo, o fornecimento de Activo&reg; (%MS) aumentou o consumo de MS e reduziu a digestibilidade dos nutrientes. No experimento II, não houve efeito dos tratamentos sobre as características de fermentação ruminal, contudo, a digestibilidade da PB foi maior nas dietas contendo monensina sódica ou óleo essencial de capim cidreira em comparação ao tratamento controle. Nos experimentos III, IV e V, não observou-se efeito dos tratamentos sobre nenhuma das variáveis estudadas. Desta forma, os resultados mais promissores foram observados para o experimento com capim cidreira, devido ao benéfico observado sobre a digestibilidade da proteína bruta. / Five experiments were developed in order to evaluate the effect of providing essential oils on ruminal fermentation and nutrient digestibility in lambs. In the first experiment (Experiment I) it was evaluated a commercial product having as active principle pepper essential oil (Activo&reg;), the experimental treatments were: negative control - basal diet (30% roughage and 70% concentrate,% DM); positive control - basal diet plus 25 mg monensin per kg of natural matter (NM) and basal diet plus 100, 200 or 300 ppm Activo&reg; (% DM). The remaining four experiments, besides of the treatments negative and positive control described in the first experiment, were also evaluated the inclusion in the diet 1.09; 2.18 or 3.27 mL/kg dry matter of essential oil extracted from West Indian lemongrass, Cymbopogon citratus (Experiment II); Essential oil extracted from the fruit of the Brazilian peppertree; Schinus terebinthifolius (Experiment III); essential oil extracted from Lemon grass; Cymbopogon flexuosus (Experiment IV) or essential oil extracted from the leaves of the Brazilian peppertree; Schinus terebinthifolius (Experiment V). In the first experiment, there was no effect of treatments on ruminal concentration of short-chain fatty acids (SCFA). However, when compared to the positive control, the supply of Activo&reg; increased dry matter intake (DMI) and reduced nutrient digestibility. In the second experiment, there was no effect of treatments on ruminal fermentation characteristics, however, the digestibility of CP was higher in diets containing monensin or essential oil of lemon grass compared to the control treatment. In the experiments III, IV and V, there was no effect of treatments on any of the variables studied. Thereby, the most promising results were observed for the experiment with essential oil of lemon grass, because of the beneficial on the digestibility of crude protein.

Este estudo teve por objetivo avaliar, in vitro, a viabilidade do uso de soluções de extratos naturais no tratamento restaurador da dentina, por meio do ensaio de resistência à microtração e análise qualitativa da superfície dentinária e interface adesiva em microscopia eletrônica de varredura (MEV). A amostra foi composta de 90 fragmentos de dentina bovina. Os fragmentos foram planificados, polidos e condicionados com ácido fosfórico 37% e, em seguida, divididos de acordo com o tratamento da dentina em 5 níveis: GI Sem tratamento (controle), GII Solução de extrato de Camellia sinensis (chá verde), GIII Solução de extrato de Punica granatum (romã), GIV Solução de extrato de Vitis vinifera (semente de uva), GV Solução de extrato de Lycium barbarum (goji berry). Os espécimes que foram utilizados na análise da resistência de união e interface adesiva tiveram as superfícies restauradas com adesivo (Adper Single Bond 2 - 3M) e resina composta (Filtek Z250 - 3M). Os 60 fragmentos utilizados para o teste de microtração (6 mm x 6 mm x 6 mm) foram seccionados em palitos de aproximadamente 1 mm&sup2, obtendo-se 4 palitos por dente (n=12). Após o teste, o padrão de falhas foi analisado em microscopia de varredura confocal a laser (MVCL). Para análise da interface adesiva, 15 fragmentos (6 mm x 3 mm x 3 mm) foram tratados com as soluções (n=3), restaurados e preparados para MEV. Os 15 fragmentos (3 mm x 3 mm x 3 mm) destinados à análise da superfície foram tratados com as soluções (n=3) e preparados para MEV. Os dados do teste de microtração (MPa) foram submetidos à ANOVA e teste de Tukey (p=0,05). Os maiores valores médios de resistência adesiva (p < 0,05) foram obtidos nos grupos controle (sem tratamento, GI - 25,69 ± 6,32), extrato de Camellia sinenis (chá verde, GII - 28,14 ± 7,66) e extrato de Vitis vinifera (semente de uva, GIV - 25,55 ± 4,00), sendo estes iguais entre si (p > 0,05). Os fragmentos tratados com o extrato de Punica granatum apresentaram os menores valores médios (p < 0,05) de resistência adesiva (Romã, GIII - 17,42 ± 4,82). Os fragmentos que receberam o extrato de Lycium barbarum apresentaram valores intermediários (Goji Berry, GV - 23,44 ± 6,78), ora similares aos dos grupos com maiores médias, ora iguais ao grupo de menor média de resistência adesiva (p > 0,05). Falhas adesivas foram predominantes nos grupos experimentais. Na análise em MEV da superfície dentinária, verificou-se superfície regular, sem camada de smear e com abertura dos túbulos dentinários em todos os grupos analisados. Na análise da interface adesiva, houve boa hibridização da embocadura dos canais, e presença de tags resinosos na maioria dos túbulos dentinários, sugerindo formação de camada hibrida. As soluções de Camellia sinensis, Vitis vinifera e Lycium barbarum não interferiram negativamente na resistência de união quando comparados ao grupo controle, sem tratamento. / This study aimed to evaluate, in vitro, the viability of using natural extracts solutions in dentin restorative treatment, by microtensile bond strength test and qualitative analysis of dentin morphology surface and adhesive interface under scanning electron microscopy (SEM). Sample was composed of 90 fragments of intracoronary bovine dentin. The fragments were flattened, etched with 37% phosphoric acid and then were divided according to the dentin treatments: GI - Untreated (control), GII - Camellia sinensis extract solution (green tea), GIII - Punica granatum extract solution (pomegranate), GIV - Vitis vinifera extract solution (grape seed), GV - Lycium barbarum extract solution (goji berry). Specimens that were used on the bond strength test and adhesive interface analysis were restored with adhesive (Single Bond 2 - 3M) and composite resin (Filtek Z250 - 3M). The 60 fragments used to microtensile test (MPa) (6mm x 6mm x 6mm) were sectioned at approximately 1mm2 sticks, 4 destined to the bonding interface analysis (n=12). After the test, the failure pattern was analyzed in confocal laser scanning microscopy (CLSM). For adhesive interface analysis, 15 pieces (6mm x 3mm x 3mm) were treated with solutions, restored and prepared for SEM (n=3). The 15 fragments (3mm x 3mm x 3mm) destined for surface analysis were treated with solutions and prepared for SEM (n=3). The microtensile test (MPa) data were submitted to ANOVA and Tukey test (p=0.05). The highest values of bond strength (p<0.05) were obtained in the control groups (untreated, GI - 25.69 ± 6.32), Camellia sinenis extract (green tea, GII - 28.14 ± 7. 66) and Vitis vinifera extract (grape seed, GIV - 25.55 ± 4.00), which are equal to each other (p>0.05). The fragments treated with Punica granatum extract (Pomegranate, GIII - 17.42 ± 4.82) showed lowest values of bond strength (p <0.05). Fragments treated with Lycium barbarum extract showed intermediate values (Goji Berry, GV - 23.44 ± 6.78), similar to those of groups with higher values and to the lower values group of bond strength (p>0.05). Adhesive failures were predominant in all groups. The SEM analysis of the dentin surface demonstrated that there was a regular surface, without smear layer and open dentinal tubules in all groups analyzed. The adhesive interface analysis, showed that there was good hybridization of the entrance of dentinal tubules, and presence of resin tags in most dentinal tubules, suggesting formation of hybrid layer. The extracts solutions of Camellia sinensis, Vitis vinifera and Lycium barbarum did not interfere negatively on the bond strength when compared to the control group without treatment.