Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-06-21T11:22:42Z No. of bitstreams: 1 2016 - Raquel Teixeira Ferreira.pdf: 4123117 bytes, checksum: d2271c63e8c851f1e25afd9a0bd8cf91 (MD5) / Made available in DSpace on 2017-06-21T11:22:42Z (GMT). No. of bitstreams: 1 2016 - Raquel Teixeira Ferreira.pdf: 4123117 bytes, checksum: d2271c63e8c851f1e25afd9a0bd8cf91 (MD5) Previous issue date: 2016-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Kalanchoe pinnata (KP) is popularly used for treating inflammatory diseases. This study investigated the antinociceptive and anti-inflammatory potential of the KP flower aqueous extract (KPFE), the ethyl acetate (EtOAcF), butanol (BuOHF) and aqueous (AqF) fractions and the main flavonoid [quercetin 3-O-?-L-arabinopyranosyl (1??) ?-L-rhamnopyranoside] (KPFV) of KP, as well as possible mechanisms of action. Swiss albino mice, male (25-35g) were pretreated with KPFE (30-300 mg/kg, s.c.) producing dose-related inhibition of acetic acid-induced writhing (ID50 164.8 mg/kg), and the subcutaneous administration of KPFE (300 mg/kg), EtOAcF (12 mg/kg), BuOHF (15 mg/kg) or AqF (210 mg/kg) reduced leukocyte migration on carrageenan-induced pleurisy in mice at 56.1%, 47.3%, 39.6% and 43.1%, respectively. At doses of up to 240 times smaller than KPFE, KPFV (0.3-3.0 mg/kg, s.c.), also inhibited leukocyte migration (ID50 1.78 mg/kg). In croton oil-induced ear edema in mice, KPFE (3-30 mg/kg, s.c.) and KPFV (0.3-3.0 mg/kg, s.c.) presented dose-related antiedematogenic activity (KPFE - ID50 4.3 mg/kg, KPFV - ID50 0.76 mg/kg). Treatment with KPFE reduced the MPO and TNF-? concentration in the pleural exudates on carrageenaninduced pleurisy test, while KPFV inhibited both isoforms of cyclooxygenase (COX), with IC50 3.8 x 10-5 M (22.1 ?g/mL) for COX-1 and a maximum COX-2 inhibition of 43.5% (IC50 >8.4 x10-5M or 50 ?g/mL). The selectivity index (COX-1 IC50/COX-2 IC50) was <0.44. These results indicate that KPFE and KPFV produced anti-inflammatory and antinociceptive activity through the COX inhibition and TNF-? reduction. This study reveals that the main flavonoid in KP flowers and leaves plays an important role in the ethnomedicinal use of this species for healing inflammatory processes / Kalanchoe pinnata (KP) ? popularmente utilizada para tratamento de doen?as inflamat?rias. Este estudo investigou o potencial antinociceptivo e anti-inflamat?rio do extrato aquoso das infloresc?ncias de KP (EAFL), a fra??o acetato de etila (FAcOEt), a fra??o butan?lica (FBuOH), a fra??o aquosa (FAq) e o flavonoide majorit?rio [quercetina 3-O-?-Larabinopiranosil (1??) ?-L-ramnopiranos?deo] (KPFV) de KP, assim como poss?veis mecanismos de a??o. Camundongos albinos, machos (25-35g) foram pr?-tratados com EAFL (30-300 mg/kg, s.c.), produzindo inibi??o dose dependente das contor??es induzidas por ?cido ac?tico (DI50 164,8 mg/kg), e a administra??o subcut?nea de EAFL (300 mg/kg), FAcOEt (12 mg/kg) ou FBuOH (15 mg/kg) reduziu a migra??o leucocit?ria na pleurisia induzida por carragenina em camundongos em 56,1%, 47,3%, 39,6% e 43,1%, respectivamente. Em doses at? 240 vezes menores que o EAFL, KPFV (0,3-3,0 mg/kg, s.c.), tamb?m foi capaz de inibir a migra??o leucocit?ria (DI50 1,78 mg/kg). No teste do edema de orelha induzido por ?leo de cr?ton em camundongos, EAFL (3-30 mg/kg, s.c.) e KPFV (0,3-3,0 mg/kg, s.c.) apresentaram atividade antiedematog?nica dose dependente (EAFL - DI50 4,3 mg/kg, KPFV - DI50 0,76 mg/kg). O tratamento com EAFL reduziu a concentra??o de MPO e de TNF-? no exsudato pleural obtido do teste da pleurisia induzida por carragenina, enquanto o KPFV inibiu ambas as isoformas de cicloxigenase (COX), com CI50 3,8 x 10-5M (22,1 ?g/mL) para COX-1 e um m?ximo de inibi??o da COX-2 de 43,5% (CI50 >8,4 x10-5M ou 50 ?g/mL). O ?ndice de seletividade (COX-1 CI50/COX-2 CI50) foi < 0,44. Estes resultados indicam que EAFL e KPFV produziram atividade anti-inflamat?ria e antinociceptiva envolvendo a inibi??o da COX e a redu??o de TNF-?. Este estudo revela que o principal flavonoide presente nas infloresc?ncias e folhas de KP possui papel importante no uso etnomedicinal desta esp?cie nos processos de natureza inflamat?ria

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-20T20:18:23Z No. of bitstreams: 1 julianarasomarquesbecho.pdf: 1211488 bytes, checksum: 4196fd1ff0cfee03d2d19782ed5e338c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-22T15:26:30Z (GMT) No. of bitstreams: 1 julianarasomarquesbecho.pdf: 1211488 bytes, checksum: 4196fd1ff0cfee03d2d19782ed5e338c (MD5) / Made available in DSpace on 2016-07-22T15:26:30Z (GMT). No. of bitstreams: 1 julianarasomarquesbecho.pdf: 1211488 bytes, checksum: 4196fd1ff0cfee03d2d19782ed5e338c (MD5) Previous issue date: 2011-03-25 / Introdução: A rutina é um flavonóide glicosilado pertencente à subclasse dos flavonols, sendo extensamente encontrada na natureza em frutas, vegetais e bebidas como o vinho. Apresenta grande importância terapêutica por melhorar a resistência e permeabilidade dos capilares, atividade antioxidante, antiinflamatória, antimitótica dentre outras. Hidrolizada como quercetina, promove a inibição da motilidade dos espermatozóides, alterações na próstata, nos níveis de testosterona e de dihidrotestosterona, fatores que interferem com a fertilidade. Entretanto não foram observados estudos para verificar seu efeito sobre o sistema reprodutor de ratos. Hipótese: A rutina possui atividade tóxica sobre o sistema reprodutor de ratos. Objetivo: Avaliar a toxicidade da rutina sobre testículos, próstata, vesícula seminal, epidídimo e na concentração dos espermatozóides epididimários, assim como no fígado, rins e baço. Métodos: Ratos Wistar adultos provenientes da Colônia do Centro de Biologia da Reprodução da Universidade Federal de Juiz de Fora, foram distribuídos, aleatoriamente, em quatro grupos: Controle que recebeu por via intragástrica 1ml de água destilada; Tratado I, II e III onde os animais receberam, pela mesma via 5, 10 e 20 mg/Kg/dia rutina, diluída em água, respectivamente, durante sete dias consecutivos. Após eutanásia realizada 10, 42 e 60 dias do início do experimento foram retirados: testículos, próstata, vesícula seminal, epidídimo, fígado baço e rins. Obteve-se secreção epididimária para contagem de espermatozóides. No sangue foram feitas dosagens bioquímicas (ALT e creatinina) e hematológicas (hematimetria,hematócrito, hemoglobina, leucometria, CHGM, HGM e VGM). Os epidídimos foram processados histologicamente e a altura do epitélio foi medida através de cortes dos epidídimos. Em cada corte foram selecionados 10 túbulos circulares ao longo do epidídimo nos quais se obtiveram oito medidas ao longo de sua circunferência. A média dos valores foi considerada representativa da altura do epitélio do túbulo. Os dados coletados foram processados por análise de variância – uma via e teste post hoc de Dunnet T3 (α=0.05), e teste de KruskalWallis (α=0.05). Para análise da altura do epitélio do epidídimo, foi ulitizado ANOVA – uma via, seguido de teste post hoc de Dunnet (α=0.05). Resultados: Animais do grupo T3 tiveram menor peso e menor consumo de ração em relação aos controles (p<0.05). O Grupo T1 eutanasiados três dias após o término do tratamento apresentaram hepatomegalia e redução de HGM, que não ocorreu em outras doses e não se manifestou aos 42 e 60 dias. Todos os grupos apresentaram redução do peso do epidídimo (p<0.05) após 10 dias do início do experimento, porém essa alteração não persistiu aos 45 e 60 dias. Outras variáveis não apresentaram diferença significativa. Conclusão: A rutina não causou efeitos tóxicos gerais persistentes nos exames realizados, mas levou à toxicidade no o epidídimo, reduzindo o seu peso entretanto, o mecanismo de tal efeito não foi identificado nesse trabalho. / Introduction: Rutin is a glycosylated flavonoid belonging to the subclass of flavonols and widely found in nature in fruits, vegetables, and beverages such as wine. It has great therapeutic importance since it improves the resistance and permeability of capillaries, as well as the antioxidant, anti-inflammatory and antimitotic activities, among others. Hydrolyzed as quercetin, it promotes the inhibition of spermatozoa motility, changes in the prostate and in the levels of testosterone and dihydrotestosterone, factors that interfere with fertility. However, no studies were found regarding its effects on the reproductive system of rats. Hypothesis: Rutin has toxic activity on the reproductive system of rats. Objective: Evaluate the toxicity of rutin on testicles, prostate, seminal vesicles, epididymis, and epididymal spermatozoa concentration, as well as liver, kidneys, and spleen. Methods: Adult rats, from the vivarium of the Center for Reproductive Biology of the Federal University of Juiz de Fora, were distributed randomly into four groups: Control, which received intragastrically 1ml of distilled water; Treated I, II and III which received 5, 10 and 20 mg/kg/day of rutin, intragastrically, diluted in water, for seven consecutive days. Once euthanasia was performed, after 10, 42 and 60 days of the beginning of the experiment; testicles, prostate, seminal vesicles, epididymis, liver, spleen, and kidneys were removed. Epididymal secretion was obtained for spermatozoa count. Biochemical (ALT and creatinine) and hematological (hematimetry, hematocrit, hemoglobin, leukocyte counts, MGHC, MGH, and MGV) dosages were performed. The epididymides were processed histologically, and the epithelial height was measured by cutting the epididymis. In each cut, 10 circular tubules along the epididymis were selected and eight measurements along its circumference were obtained. The mean value was considered representative of the epithelial height of the tubule. The collected data were processed by variance analysis - one way and a post-hoc Dunnet T3 test (α = 0.05), and Kruskal-Wallis test with significance level α = 0.05. To analyse the epididymal epithelium, we used one way - ANOVA followed by Dunnet post hoc test (α = 0.05). Results: Animals of the TIII group had lower weight and lower feed intake compared to the control (p <0.05). The animals of the TI group, euthanized three days after the end of treatment, showed hepatomegaly and reduction of MGH, which did not occur in other doses and did not manifest at 42 and 60 days. All groups showed a reduction in the epididymis weight (p <0.05) after 10 days into the experiment, but this change did not endure at 45 and 60 days. Other variables showed no significant difference. Conclusion: Rutin did not cause persistent general toxic effects; however, it manifested toxicity to the epididymis, reducing its weight. Nevertheless, the mechanism of this effect was not identified in this study.

Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-03-28T16:51:43Z No. of bitstreams: 1 Oliveira, Rafael Portugal Rizzo Franco de [Dissertação, 2014].pdf: 2189274 bytes, checksum: ea08452f36c971680598c7fa0742290c (MD5) / Made available in DSpace on 2017-03-28T16:51:43Z (GMT). No. of bitstreams: 1 Oliveira, Rafael Portugal Rizzo Franco de [Dissertação, 2014].pdf: 2189274 bytes, checksum: ea08452f36c971680598c7fa0742290c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A busca por medicamentos mais seguros e com menores efeitos adversos levou o homem a desenvolver novas tecnologias de formulação. Neste contexto, a nanotecnologia tem contribuído para o surgimento de medicamentos cada vez mais específico para a doença a qual está destinado a tratar. O vírus Herpes simplex (HSV) é um patógeno muito conhecido pelo homem e estima-se que grande parte da população já esteja contaminada de maneira assintomática. Nas infecções bacterianas têm se tornado cada vez mais comum o surgimento de cepas resistentes aos antibióticos, por isso a descoberta de novos ativos antimicrobianos se torna cada dia mais essencial. Os flavonoides são metabolitos especiais que garantem às plantas resistência a microrganismos, tornando-se por isso, bastante promissores no desenvolvimento de novos agentes antivirais e antibacterianos. O presente estudo tem como objetivo elaborar uma nanoemulsão a base do extrato rico em flavonóides extraídos das folhas de Ocotea notata e avaliar suas atividades biológicas. O extrato de O. notata foi obtido por maceração e a análise de sua atividade antiviral demonstrou que esses possuíam percentual de inibição superior a 99% frente ao HSV tipos 1 e 2. Além disto, foi demonstrada a atividade antibacteriana desse extrato frente a quatro cepas bacterianas: S. aureus (MIC = 0,31 mg/mL), E. coli (MIC = 5,0 mg/mL), P. aeruginosa (MIC = 2,5 mg/mL) e Salmonella (MIC = 2,5 mg/mL).Uma nanoemulsão estável constituída de Miristato de isopropila, Transcutol®, Tween® 80, água e 1% (p/p) dos flavonoides de O. notata foi desenvolvida e avaliada quanto às atividades descritas. Como esperado, a nanoemulsão não apresentou atividade, uma vez que a concentração do ativo incorporada à formulação foi muito pequena (1%) não sendo possível observar as atividades biológicas nos modelos testados. Faz-se necessário, portanto, mais estudos para o desenvolvimento de um produto contendo o extrato de O. notata a fim de otimizar sua eficácia / The search for safer and minor adverse effects has led man to develop new technologies formulation that increases patient comfort. In this context, nanotechnology has contributed to the emergence of more specific drugs for the disease which is intended to treat. Herpes simplex virus (HSV) is a pathogen well known by man and it is estimated that a great part of the population is already infected asymptomatically. In bacterial infections has become the emergence of antibiotic-resistant strains, so the discovery of new antimicrobial active is becoming most essential. Flavonoids are special plant metabolites which guarantee resistance to microorganisms, making it therefore very promising in the development of new antiviral and antibacterial agents. This study aims to develop a nanoemulsion base of flavonoids extracted from leaves of Ocotea notata and evaluate their biological activities. Flavonoids of O. notata were extracted by maceration and analysis of its antiviral activity demonstrated that these had higher inhibition percentage at 99% compared to HSV types 1 and 2. Furthermore, we demonstrated the antiviral activity extract against four bacterial strains: S. aureus (MIC = 0.31 mg / ml), E. coli (MIC = 5.0 mg / ml), P. aeruginosa (MIC = 2.5 mg / ml) and Salmonella (MIC = 2.5 mg / ml). A stable nanoemulsion consisting of isopropyl myristate, Transcutol®, Tween® 80, and 1% (w/w) of the flavonoids of O. notata was developed and evaluated with respect to the described activities. As expected, the nanoemulsion showed no biological activity, once the concentrations of the active incorporated in the formulation was very small (1%) in the tested models.. It is necessary, therefore, further studies to the development of a product containing extract of O. notata in order to optimize its effectiveness

Le bois est un matériau renouvelable utilisé par l’Homme pour la construction, l’ameublement, la fabrication du papier, l’énergie, etc. Le bois contient des extractibles d’un grand intérêt économique appartenant à diverses familles chimiques telles que les terpènes, les flavonoïdes, les tanins, etc. Les nœuds (base de la branche englobée dans le tronc) de certaines essences sont extrêmement riches en extractibles.Ce travail a pour objectif l’analyse des variabilités interspécifiques, intraspécifiques et intra-arbre des extractibles nodaux, afin de cibler les essences, les stations et les parties de l’arbre les plus riches. Pour cela, les nœuds de vingt-trois essences, puis ceux de quinze sapins ayant poussé dans des conditions différentes ont été extraits par différents solvants et analysés. Les résultats confirment la richesse des nœuds par rapport au duramen et à l’aubier pour toutes les essences. Globalement, les nœuds des résineux contiennent plus d’extractibles que les feuillus. Les principaux composés identifiés chez les résineux sont des lignanes, des stilbènes, des flavonoïdes et des terpènes. L’acide gallique et des flavonoïdes sont présents chez les feuillus. L’étude du profil vertical montre que les concentrations diminuent de la base du houppier vers la cime de l’arbre. De plus, les résultats mettent en évidence l’influence des conditions de croissance puisque les arbres dominants, et/ou ayant poussé selon des sylvicultures dynamiques sont particulièrement riches en extractibles nodaux. Ces résultats permettent d’envisager la valorisation des coproduits des industries du bois en tant que ressource de molécules bioactives pour diverses applications. / Wood is a renewable material used by man for construction, furniture, paper making, energy, etc. Wood contains extractives of great economic value which belong to various chemical families such as terpenes, flavonoids, tannins, etc. The knots (base of the branch embedded in the trunk) of some tree species are extremely rich in extractives.This study aims at analysing the inter-specific, intra-specific and within-tree variabilities of knotwood extractives to target the richest species, stations and tree parts. For that purpose, the knots of twenty-three species and those of fifteen firs grown under different conditions were extracted using several solvents and analysed. The results confirm the richness of knots compared to heartwood and sapwood for all species. Overall softwood knots contain mainly more extractives than hardwoods. The main compounds identified in softwoods are lignans, stilbenes, flavonoids and terpenes Gallic acid and flavonoids are present in hardwoods. The study of the vertical profile shows that concentrations decrease from the base of the crown to the tree tip. In addition, the results highlight the influence of growth conditions since dominant trees and/or those grown according to dynamic silvicultures are particularly rich in knot extractives. These results allow considering the valorization of wood industries by-products as bioactive molecules resource for various applications.

Les flavonoïdes sont des substances naturelles connues pour leurs propriétés anti-inflammatoires, anti-cancéreuses ou anti-virales chez l'homme. Chez les végétaux, ils participent notamment à leur protection vis-à-vis d'organismes pathogènes. La voie de biosynthèse des flavonoïdes est l'une des plus étudiées chez les plantes et notamment chez la vigne : Vitis vinifera. Cependant, la ou les enzymes impliquées dans les dernières étapes de biosynthèse conduisant aux anthocyanes et aux proanthocyanidines restent, à ce jour, peu ou pas connues. L’étude que nous proposons a pour but de concevoir des sondes moléculaires d’affinité susceptibles d’interagir avec une ou plusieurs enzymes impliquées dans ces dernières étapes de biosynthèse. Ces sondes, basées sur la technologie émergeante de protéomique chimique : « Activity- and affininity Based Protein Profiling » (ABPP), ont été validées à l’aide d’une enzyme modèle : la leucoanthocyanidine dioxygénase (LDOX). Elles ont ensuite été appliquées à des extraits complexes de protéines issus de Vitis vinifera. / Flavonoids are natural substances known for their anti-inflammatory, anti-cancerous and anti-virals properties in humans. In plants, they are one of the molecules responsible for fighting pathogens. The flavonoid biosynthesis pathway as been greatly studied in plants, especially in that of the grapevine: Vitis vinifera. However, detailed studies of the exact function of the enzymes involved in the last steps of the biosynthesis of anthocyanins and proanthocyanidins remains largely lacking.The study that we propose is to synthesize molecular probes designed to specifically interact with enzymes involved in the last stages of flavonoids biosynthesis. Our probes, based on the emerging chemical proteomic technology, activity- and affinity based protein profiling (ABPP), were validated with a model enzyme: leucoanthocyanidin dioxygenase (LDOX). After which, they were used with complex protein mixtures from Vitis vinifera.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Daniela Uramová Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of diploma thesis: Pharmacokinetics of flavanones The aim of the work was to summarize the available information regarding the fate of the flavanones in the human organism. These flavonoids are a common part of human diet, and therefore oral administration is the most relevant and examined. There are many obstacles in the digestive tract which are lowering their absorption. Flavanones in human food occur mainly in the form of glycosides, and therefore must be deglycosylated by the β- glucosidase enzyme family. Aglycones are absorbed mainly in the small intestine. Flavonoids in the form of non-cleavable glycosides (e.g., rutinosides) are absorbed in the distal parts of the digestive system, after cleavage of the sugar component by intestinal bacteria. They also decompose the flavanone ring. This leads to substances with a phenylpropionic structure which can be absorbed. In general, flavanones are subject to extensive metabolism by cytochrome P450, not only in the liver but also in the enterocytes, which greatly limits their bioavailability. They are also rapidly conjugated with glucuronic or sulfuric acid. The...

Les flavonoïdes sont des composés poly-hydroxylés d’origine végétale, connus pour leurs vertus pour la santé. Afin d’obtenir des dérivés plus stables et solubles dans des formulations hydrophobes tout en conservant les activités biologiques des molécules d’origine, une solution consiste à acyler ces composés de manière régiosélective. Ceci peut être accompli en utilisant des lipases comme catalyseurs, en milieu organique. Grand nombre d’études expérimentales sur ces bioprocédés sont disponibles, mais aucune d’entre elles n’apporte d’explication, au niveau moléculaire, de la sélectivité de ces réactions d’acylation. Le but de cette étude est d’appliquer différents outils de simulation moléculaire pour mieux comprendre, au niveau moléculaire, les propriétés de sélectivité de l’acétylation de trois flavonoïdes (quercétine et ses dérivés glycosylés isoquercitrine et rutine), en utilisant les lipases CALB et PCL. D’abord, des simulations de docking ont été appliquées, afin d’obtenir les positions et les orientations les plus probables des flavonoïdes dans la cavité des lipases préalablement acétylées. Ensuite, des simulations de dynamique moléculaire ont été exécutées sur les complexes obtenus par docking, afin d’étudier stabilité structurale des complexes sur une période de temps et notamment la stabilité des interactions enzyme-substrats. Enfin, des simulations basées sur une approche de chimie quantique (DFT) ont été appliquées pour évaluer la réactivité chimique des flavonoïdes dockées dans les complexes. Les premières tendances observées aux cours des simulations ont présenté une bonne corrélation avec les résultats expérimentaux d’acétylation. Globalement, les résultats obtenus ont montré que la sélectivité de ces réactions dépend de l’orientation des substrats (flavonoïde et acétate) dans la cavité catalytique de la lipase, des interactions intermoléculaires stabilisant ces substrats et de la réactivité chimique intrinsèque des groupements OH des flavonoïdes se situant à proximité des résidus catalytiques / Flavonoids are plant-produced polyhydroxylated compounds, well-known for their beneficial health effects. In order to obtain more stable and soluble derivatives for incorporation in hydrophobic formulations without damaging the biological activities of the native molecules, a solution consists to perform a regioselective acylation of these molecules. This can be accomplished by using lipase biocatalysts, in organic media. Several experimental studies dealing with such processes are available, but none of them give any explanation, at the molecular level, for the regioselectivity of such reactions. This study aimed to apply different molecular modelling tools in order to better understand, at the molecular level, the selectivity properties of the acetylation of three flavonoids (quercetin and its glycosylated derivatives isoquercitrin and rutin), by using the lipases CALB and PCL. Firstly, docking simulations were applied, in order to obtain the most probable positions and orientations of the flavonoids in the cavities of acetylated lipases. Then, molecular dynamics simulations were performed, aiming to study the structural stability of the complexes upon a period of time and specially the stability of the enzyme-substrates interactions. Finally, quantum chemical simulations (DFT) were applied to evaluate the chemical reactivity of the flavonoids as docked in the complexes. The trends observed during the simulations were well correlated with previous experimental results on the acetylation reaction of these flavonoids. Overall, the results showed that the selectivity in such reactions depends upon the substrates (flavonoid and acetate) orientations in the enzyme catalytic cavity, the intermolecular interactions that stabilize these substrates and the intrinsic chemical reactivity of the flavonoids OH groups reaching the catalytic residues

Les graines d’Arabidopsis sont constituées de trois principaux compartiments : l’embryon, l’albumen et les tissus maternels. Ces derniers sont composés en particulier d’une enveloppe, impliquée dans la protection de la graine, sa dormance, ainsi que dans le transport de nutriments. L’endothélium est la couche cellulaire la plus interne de l’enveloppe, et tient lieu d’interface entre l’albumen et le reste de l’enveloppe. C’est aussi le site de production dans la graine des proanthocyanidines (PAs), un type particulier de flavonoïdes, d’intérêt à la fois physiologique et agronomique, et responsables de la couleur marron des graines d’Arabidopsis. À ce jour, une vingtaine de gènes impliqués dans l’accumulation de PAs ont été découverts et nommés TRANSPARENT TESTA (TT) ou TRANSPARENT TESTA GLABRA (TTG), en référence à la couleur jaune des graines mutantes correspondantes. Contrairement à d’autres gènes TT ou TTG, montrés être impliqués dans des processus enzymatiques ou de régulation transcriptionnelle, on suspecte que TT16, TT1 et TTG2 sont plutôt impliqués dans des mécanismes développementaux, ce que nous nous proposons d’étudier ici en détail. Dans cette étude, nous montrons que TT16 et TT1 contrôlent la morphologie et la différentiation des cellules de l’endothélium et de sa couche cellulaire adjacente, l’« ii1’ », tandis que TTG2 apparaît ne contrôler que la différentiation de l’endothélium. Nos résultats suggèrent aussi que TT16, TT1 and TTG2 contrôlent différents aspects du profil développemental de l’ii1’. Par ailleurs, nous étudions les mécanismes moléculaires impliqués dans la déposition d’une barrière de cutine apoplastique séparant albumen et endothélium. Nos résultats indiquent en particulier que cette déposition fait partie du processus de différentiation de l’endothélium et qu’elle est contrôlée par TT16, TT1, et dans une moindre mesure TTG2. Finalement, nos données indiquent que le développement et la différentiation de l’endothélium – incluant la déposition de cette barrière apoplastique - sont contrôlés par la fécondation de la cellule centrale du sac embryonnaire, tandis que le développement de l’ii1' requiert aussi la fécondation de la cellule-œuf. / In Arabidopsis, seeds are composed of three main compartments: an embryo, an endosperm and maternal tissues. The latter comprise in particular a seed coat, involved in seed protection, nutrient transport and dormancy. The endothelium is the innermost cell layer of the seed coat, acting as the interface between seed coat and endosperm. Moreover, the endothelium is the production site of proanthocyanidins (PAs), a class of flavonoid compounds of physiological and agricultural interest that give their brown color to Arabidopsis seeds. To date, several genes involved in PA accumulation in the endothelium have been discovered and named TRANSPARENT TESTA (TT) or TRANSPARENT TESTA GLABRA (TTG), according to the yellow color of their respective mutant seeds. Contrary to other TT and TTG genes, rather involved in enzymatic processes or transcriptional regulation, TT16, TT1 and TTG2 are thought to be involved in developmental processes, which we propose here to thoroughly characterize. In this study, we show that TT16 and TT1 control cell morphology and differentiation in the endothelium and in its adjacent cell layer, the so-called ii1’, whereas TTG2 appears to play roles in endothelium differentiation solely. Our results also suggest that TT16, TT1 and TTG2 control different aspects of the ii1’ developmental patterning. Furthermore, we shed light on genetic mechanisms controlling the deposition of an apoplastic cutin barrier separating endothelium and endosperm. In particular, our results indicate that such a deposition makes part of endothelium differentiation process and is controlled by TT16, TT1, and in a lesser extent TTG2. Finally, our data indicate that endothelium development and differentiation – including deposition of this apoplastic barrier - are controlled by the fertilization of the embryo sac central cell, whereas ii1’ development also requires the fertilization of the egg-cell.

Dihydromyricetin (DMH) is a natural flavonoid compound with positive effects on the human organism. In traditional Chinese medicine, plants containing DMH were used to treat liver diseases and to reduce alcohol intoxication. The effects of DHM on ethanol metabolism are not yet completely understood. Effects of DHM during alcohol intoxication were studied on primary hepatocytes of rats. DCFDA and DHR probes were used to prove that DHM (depending on concentration) reduces the number of reactive oxygen and nitrogen species in primary hepatocytes. However, the hepatoprotective effects of DHM were not achieved when presence of the alanine aminotransferase (ALT) was used to measure the damage of cells exposed to alcohol. Further, the effects of DHM on alcohol metabolism were studied in vivo. Rats were administered with single dose of ethanol or ethanol combined with DHM. Measured blood levels of ethanol and acetaldehyde show that DHM has no effects on the rate or levels of alcohol metabolism. The effects of DHM were also studied with repeated alcohol administration. In the group that was administered also DHM, increased blood levels of ethanol were measured. This points that DHM slow down the metabolic rate of ethanol. Obtained results did not prove any positive effects of DHM on alcohol metabolism....

Medicinal plants are important and valuable natural resources. South Africa is well-endowed with very diverse flora and fauna that include a considerable number of medicinal plant species. Most medicinal plants have gained popularity for the treatment or prevention of various ailments. Ginger species (Zingiber officinale and Siphonochilus aethiopicus) are essential natural resources, which provide many useful products for use in food as a spice or as medicine. The two species contain beneficial secondary metabolites useful for treating many diseases and numerous digestive imbalances such as indigestion, vomiting, heartburn, diarrhoea and pregnancy-related nausea. However, the role of different agronomic practices such as irrigation, water stress and nutrient management are crucial for enhancing the yield and quality of ginger species. Due to climate change, rainfall is often less while more erratic, putting more pressure on irrigation resources in agriculture to sustain or even increase food production for a growing population. The major plant factors negatively affected by water limitations are plant growth, quality and crop yield. The second most constraining factor in plant growth and quality is the lack of plant nutrients. Macronutrients, such as N, P and K are most important in plants to complete their life cycle and play a significant role in the growth and development of plants. This study investigated the growth, yield and phytochemical profiling of two ginger species under different maximum allowable depletion levels of soil water content and nutrient management. The soil water study was conducted under a rain-shelter at the Experimental Farm on the Hillcrest campus of the University of Pretoria, South Africa. The experiment was laid out in a randomized complete block design (RCBD) with two factors (ginger species and water regimes) and three replicates per treatment. The two experimental factors included the two species of ginger (commercial and African ginger) and four water levels (irrigated as soon as 20-25% of available soil water (ASW) was depleted, 40-45% of ASW depleted, 60-65% of ASW depleted and 80-85% of ASW depleted). Growth and development parameters such as height, leaf number and stem number were evaluated and varied between species and irrigation treatments. Irrigation treatment effects on plant growth and development were dependent on plant species. Leaf area index and fractional interception of photosynthetically active radiation (FIpar) values were higher in African ginger than commercial ginger in both seasons. Scanning electron microscopy images showed that both ginger species had more stomatal pores and open stomata under well-watered than stressed conditions. The study demonstrated that fresh and dry yields were higher for commercial ginger, compared to African ginger. The fresh and dry matter yields for severely water stressed plants were higher for commercial ginger than for African ginger. Water use efficiency in terms of fresh commercial ginger yield was highest for the moderately water-stressed treatment. The severely water-stressed irrigation regime (i.e. 80-85 MAD) resulted in higher production of total flavonoid content, phenolic content and increased antioxidant activity in both species. / Thesis (PhD)--University of Pretoria, 2019. / Plant Production and Soil Science / PhD / Unrestricted