Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-03-30T16:59:58Z No. of bitstreams: 1 Fernandes, Caio Pinho [Dissertação, 2011].pdf: 2382170 bytes, checksum: 7a855b1da9b229c8c3803eccbfdf9be5 (MD5) / Made available in DSpace on 2017-03-30T16:59:58Z (GMT). No. of bitstreams: 1 Fernandes, Caio Pinho [Dissertação, 2011].pdf: 2382170 bytes, checksum: 7a855b1da9b229c8c3803eccbfdf9be5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Manilkara subsericea (Mart.) Dubard (Sapotaceae) é popularmente cohecida no Brasil como “guracica”. Neste trabalho, é descrito o fracionamento bioguiado pelo ensaio para inibidores da acetilcolinesterase de uma mistura contendo acetato de beta-amirina e acetato de alfa-amirina e a obtenção de uma mistura de ácido ursólico e ácido oleanólico. Esta é a primeira vez que a atividade anticolinesterásica de uma mistura contendo acetato de beta amirina (76,3%) e acetato de alfa amirina (23,7%) é descrita. Também foi verificada a eficiência de extratos de polaridade distintas e da misturas dos acetatos de beta e alfa amirina no desenvolvimento de duas espécies de insetos (Oncopeltus fasciatus e Dysdercus peruvianus). O extrato etanólico de folhas e os extratos hexânico, diclorometânico, acetato de etila e butanólico provenientes da partição realizada com o extrato etanólico bruto de frutos foram capazes de induzir mortalidade, atraso no desenvolvimento e inibição da muda. Além disso, os extratos hexânico, diclorometânico e butanólico, causaram mal formação em insetos adultos. Estes resultados indicam que extratos de M. subsericea atuam como inibidores do crescimento de fitófagos e que o acetato de beta amirina e acetato de alfa amirina podem ser utilizados como potenciais marcadores químicos em possíveis formulações de produtos para controle de pragas agrícolas. Extratos e fração obtida de M. subsericea foram testados frente a Staphylococcus aureus ATCC 25923 e Escherichia coli ATCC 25922. O extrato etanólico de folhas, extrato etanólico de caules, extrato hexânico de caules, extrato diclorometânico de caules, extrato acetato de etila de caules, extrato butanólico de caules, extrato hexânico de frutos, extrato diclorometânico de frutos e a mistura dos acetatos de beta e alfa amirina mostraram atividade frente a S. aureus. Somente o extrato etanólico de caules apresentou atividade frente a E. coli. Este é o primeiro estudo sobre atividade biológicas e fitoquímico de M. subsericea e esperamos com estes resultados, contruir para a valorização desta espécie / Manilkara subsericea (Mart.) Dubard (Sapotaceae) is popularly known in Brazil as “guracica”. In the present study, it is reported the bioguided fractionation by the bioassay for anticholinesterase inhibitors of a mixture containing beta-amyrin acetate and alpha-amyrin acetate and the achievement of a mixture containing oleanolic acid and ursolic acid. This was the first time that the anticholinesterasic activity of a mixture containg the triterpenes beta-amyrin acetate (76.3%) and alpha-amyrin acetate (23.7%) was described. We also evaluated the efficacy of extracts with distinct polarity and of the mixture of beta- and alpha-amyrin acetate from Manilkara subsericea on the development of two species of agricultural pest insects (Oncopeltus fasciatus and Dysdercus peruvianus). The etanolic extract from leaves, the hexanic extract, dichloromethanic extract, ethyl acetate extract and buthanolic extract from fruits were able to induce mortality, delay development and molt inhibition. These results indicate that M. subsericea extracts acts as a potent growth inhibitor of phytophagous hemipteran nymphs and indicates that beta- and alpha-amyrin acetate can be used as chemical markers for possible formulations of products to be used in control programs against crop pests. On the present study we tested M. subsericea extracts against Staphylococcus aureus ATCC 25923 e Escherichia coli ATCC 25922. The ethanolic extract from leaves, ethanolic extract from stems, hexanic extract from stems, dichloromethanic extract from stems, ethyl acetate extract from stems, buthanolic extract from stems, hexanic extract from fruits, dichloromethanic extract from fruits and a mixture of beta- and alpha amyrin acetates showed activity against S. aureus, with exception of the the ethyl acetate extract and buthanol extract from fruits. Only the ethanolic extract from stems showed activity against E. coli. This is the first contribution about phytochemistry and biological activities of M. subsericea and we hope that these results contribute for preservation of this species

Depuis une vingtaine d’années, l’utilisation massive des antibiotiques a provoqué l’apparition de souches bactériennes résistantes contre la plupart des familles d’antibiotiques disponibles sur le marché pharmaceutique. L’apparition de souches multirésistantes voire totorésistantes notamment dans le milieu hospitalier, pose de manière croissante des difficultés thérapeutiques et constitue un grave problème de santé publique. Lors de mon doctorat, deux approches ont été abordées.La première approche consiste à inhiber les enzymes DapF et MurE impliquées dans la voie de biosynthèse du peptidoglycane, composant principal de la paroi des cellules bactériennes. Nous avons donc préparé des acides aminés comportant des groupes fonctionnels triazolyle ou alcynyle, analogues stériquement contraints de l’acide 2,6-diaminopimélique (méso-DAP).La deuxième approche développée au laboratoire repose sur le développement d’adjuvants d’antibiotiques, permettant de cibler spécifiquement les protéines responsables des mécanismes de résistances (Histidines kinases, HKs). Ce travail a permis l’obtention de trente-trois molécules dérivées du thiophène, dont huit présentent une activité biologique contre trois HKs différentes (1,63 < CI50 (μM) < 243,9). De plus, sur les huit molécules biologiquement actives, deux ont présenté une inhibition de la croissance bactérienne contre des bactéries à gram-positif et/ou à gram-négatif (B. subtilis, S. aureus, B. anthracis, E. coli…) et une restaure la sensibilité de souches bactériennes (E. coli productrice de β-lactamases à spectre large (BLSE) et S. aureus résistant à la méticilline (SARM)) à l’antibiotique approprié (céfotaxime). / Over the two past decades, the massive use of antibiotics has led to the emergence of resistant bacterial strains against most families of antibiotics available on the pharmaceutical market. The emergence of multiresistant and totoresistant bacterial strains particularly in hospitals, which create increasing problem in the development of new therapeutics and constitutes serious public health threat problems. During my PhD, two approaches were discussed.The first approach of this project consist in targeting the DapF and MurE enzymes, which are implicated in the biochemical pathway for peptidoglycan biosynthesis, a key component of the bacterial cell wall. Consequently, we prepared amino acids derivatives with triazolyl and alkynyl groups, sterically hindered analogs of 2,6-diaminopimelic acid (meso-DAP).The second approach is the development of antibiotic adjuvants, to target specific proteins implicated in the development of bacterial resistance mechanisms (Histidine kinases, HKs). This work has enabled the development of thirty-three thiophene derivatives, eight of them have biological activity against three HKs (1.63 < IC50 (μM) < 243.9). In addition, among the eight molecules with biological activity, two of them present inhibition of bacterial growth (bactericide) against both gram-positive and/or gram-negative bacteria (B. subtilis, S. aureus, B. anthracis, E. coli…) and one of them restores the sensibility of bacterial strains (E. coli producing extended spectrum of β-lactamases (ESBL) and S. aureus resistant to methicillin (MRSA)) to the appropriate antibiotic (cefotaxim).

>Magister Scientiae - MSc / Extracts from the root bark, stem bark, and leaves of R. natalensis were screened for antibacterial activity against standard bacterial strains; Staphylococcus aureas, Escherichia coli and Pseudomonas aureginosa, and fungi; Candida albicans, Trichophyton mentagrophytes or Microsporum gyseum. Chromatographic techniques were utilized to isolate pure compounds. This study validates and documents, in a systematic way, the antimicrobial properties of the R.natalensis used for many years by many people of the world. It also provides valuable information for further phytochemical isolation and characterization studies of active compounds, necessary for the development of new drugs. The extractions were carried out using broad spectrum of solvents (hexane, dichloromethane, ethyl acetate, and methanol).Fractionation was done using standard chromatographic techniques. A total of seven (7)compounds were isolated from R. natalensis. Three of the isolates were characterized and their structures were unambiguously established by detailed spectroscopic analysis that involved high resolution mass spectrometry, 1D and 2D-NMR spectral data experiments 1H, 13C, DEPT,COSY, HMBC, and NOESY. These compounds are: 3-(1-(2,4-dihydroxyphenyl)-3,3-bis(4- hydroxyphenyl)-1-oxopropan-2-yl)-7-methoxy-4H-chromone-4-one (39), Rhuschromone, a novel compound isolated for the first time, 2’,4’ dihydroxychalcone-(4-O-5’’’)-4’’,2’’’,4’’’-trihydroxychalcone (40) and 3-((Z)-heptadec-13-enyl) benzene-1,2-diol (41), an urushiol.Compound 39 recorded the highest activity zone of inhibition (21mm) against S. aureas, which was found to be 50% as active the chloramphenicol standard used. The traditional use of the extracts in infections and inflammatory conditions is rationalized based on the content of the isolated compounds, and it has been proposed that the total crude extract, with its contents of so many bioactive compounds, could be formulated for use in many infections, microbial or fungal.Furthermore, not all of the species studied to date have been fully characterized for potential bioactivities. Thus, there remains a significant research gap spanning the range from lead chemical discovery through process development and optimization in order to better understand the full bioactive potential of many of these plants.

Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Neoplasms are a major cause of death worldwide and have been worrying about the medical and scientific community, as most anticancer vector does not act on cancer cells, triggering numerous side-effects and, in some cases, resistance to treatment. No less worrying is the resistance acquired by bacteria, which culminate in strains with the phenomenon of multi-drug resistance commercially available. In this context, many research groups that adopted the medicinal chemistry, turn their studies to the discovery of new molecules that may be more selective therapeutic approaches with fewer side effects than currently exist. Triazenes compounds represent a class of compounds having wide versatility with proven pharmacological antimicrobial and antitumor activities. Similarly, considering the results from several studies relevant complexes of palladium (II) have been considered as promising therapeutic agents. As a result, two novel compounds were synthesized, and a binder, and a triazene triazenido complex with palladium (II), which according to the IUPAC nomenclature rules were so named, respectively: 1,3-Bis(4-sulfonamidephenyl)triazene (1) and {trans-Bis-[1,3-bis-(4sulfonamidephenyl)triazenide]bis(piridine)palladium(II)}{piridine)4palladium(II)} {potassim(I)}.water (2). We assess the cytotoxic potential of such compounds by colorimetric assay bromide 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Mononuclear cells from different types of leukemia and control samples were incubated for 24 hours with the compounds at concentrations 12.5, 50 and 100 μmol mL-1. To examine the antimicrobial activity of the compounds we used the measurement method of broth microdilution by determining the minimum inhibitory concentration (MIC) against the gram positive and gram negative bacteria. The results showed that the compounds showed significant cytotoxicity in the tested samples, but the compound 2 had lower IC50 than 1. Significant differences were observed between the compounds in the samples of CML and at concentrations 12,5 e 50 μmol mL-1. The antibacterial activity was found narrow spectrum, focused on gram-positive strains. / As neoplasias constituem uma das principais causas de morte no mundo e vêm preocupando a comunidade médica e científica, visto que a maioria dos antineoplásicos não age de forma vetorizada nas células cancerosas, desencadeando inúmeros efeitos colateriais e, em determinados casos, refratariedade ao tratamento. Não menos preocupante, são as resistências adquiridas pelas bactérias, as quais culminam em cepas com fenômeno de multirresistência aos fármacos disponíveis comercialmente. Neste contexto, muitos grupos de pesquisas os quais adotam a química medicinal, voltam seus estudos para a descoberta de novas moléculas que possam constituir abordagens terapêuticas mais seletivas e com menos efeitos colaterais que as existentes atualmente. Os compostos triazenos representam uma classe de compostos com ampla versatilidade farmacológica com comprovadas atividades antitumorais e antimicrobianas. De maneira semelhante, considerando os resultados de vários estudos relevantes, complexos de Paládio(II) vêm sendo considerados como promissores agentes terapêuticos. Em vista disso, foram sintetizados dois compostos inéditos, sendo um ligante triazeno e um complexo triazenido com paládio(II), os quais de acordo com as normas de nomenclatura da IUPAC, foram assim denominados, respectivamente: 1,3-Bis(4-sulfonamidafenil)triazeno (1) e {trans-bis-[1,3-bis-(4-sulfonamidafenil)triazenido-κN1]bis(piridina κN -)paládio(II)}{tetra(piridina- κN)paládio(II)}bis(potássio)}·monohidratado (2). Avaliamos o potencial citotóxico desses compostos através do ensaio colorimétrico com brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazólio (MTT). As células mononucleares de diferentes tipos de leucemia e a amostra controle, foram incubadas durante 24 horas com os compostos nas concentrações 12,5, 50 e 100 μmol mL-1. Para analisar a atividade antimicrobiana dos compostos, utilizou-se a metodologia quantitativa microdiluição em caldo, com a determinação da concentração inibitória mínima (CIM), frente à bactérias gram positivas e gram negativas. Os resultados demonstraram que os compostos apresentaram citotoxicidade importante nas amostras testadas, porém o composto 2 obteve menores IC50 que o 1. Diferenças significativas entre os compostos foram observadas nas amostras de LMC e nas concentrações 12,5 e 50 μmol mL-1. A atividade antibacteriana encontrada foi de estreito espectro, voltada às cepas gram positivas.

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / The development of products with antimicrobial, inhibitory or even lethal action has attracted considerable attention in widely different research and applications fields. The present work studies the obtaining of an antimicrobial material derived from activated carbon submitted to adsorption in a medium with silver ions. It s divided into five chapters, dealing respectively of: introduction (subject s delimitation; research objectives; study s structure); literature review (antimicrobial materials, metal ions, activated carbon impregnated with silver (ACIS); ACIS s details of obtaining and applications); materials and methods (type of research, experiments, characterization tests); results and discussions and conclusions. To characterize the material obtained, in addition to the surface area analysis, inhibitory and bactericidal effects of the samples were evaluated by microbiological testing with different bacteria. About the experimental methodology, it was tested the effects of the silver ions impregnated on coal in cultures of bacteria Escherichia coli and Staphylococcus aureus from different strains. These effects were evaluated by minimum inhibitory concentration and minimum bactericidal concentration tests. The results for the material obtained confirmed the action of silver as an important antibacterial agent. / O desenvolvimento de produtos com ação antimicrobiana, inibitória ou mesmo letal, tem atraído considerável atenção nos mais distintos campos de pesquisa e aplicações. O objetivo deste estudo foi obter um material antimicrobiano a partir de carvão ativado submetido à adsorção em um meio com íons de prata. O trabalho está dividido em cinco capítulos, tratando respectivamente de: introdução (delimitação do tema; objetivos da pesquisa; estrutura do estudo); fundamentação teórica (materiais antimicrobianos; íons metálicos; carvão ativado impregnado com prata (CAIP); detalhes de obtenção e aplicações do CAIP); materiais e métodos (tipo de pesquisa; experimentos; testes de caracterização); resultados e discussões e considerações finais da autora. Para a caracterização do material obtido, além de análise de área superficial, avaliaram-se os efeitos inibitório e bactericida das amostras através de testes microbiológicos com diferentes bactérias. Quanto à metodologia experimental aplicada, foram testados os efeitos da presença de íons de prata no carvão em culturas de bactérias Escherichia coli e Staphylococcus aureus de diferentes cepas. Tais efeitos foram avaliados através de testes de concentração mínima inibitória e concentração mínima bactericida. Os resultados referentes ao material obtido confirmaram a ação da prata como um importante agente antibacteriano.

La valorisation des dérivés phénoliques et terpéniques issus de la biomasse s’insère parfaitement dans le défi actuel de nos sociétés qui pousse la chimie traditionnelle à évoluer vers une chimie durable. De par leur nature insaturée, les terpènes se montrent particulièrement intéressants pour synthétiser de nouveaux matériaux par réaction de chimie thiol-ène. Parallèlement, les dérivés phénoliques peuvent être facilement modifiés en synthons insaturés, susceptibles de réagir dans ces mêmes réactions. Ainsi, une large gamme de matériaux à base de linalol et d’eugénol a été élaborée sous irradiation UV. Une approche par photochimie a été privilégiée puisqu’elle s’inscrit parfaitement dans le cadre d’une chimie plus respectueuse de l’environnement. L’effet bénéfique des fonctions oxygénées du linalol et du phénol de l’eugénol sur l’activité antibactérienne a été démontré contre deux souches bactériennes principalement responsables du développement des maladies nosocomiales : S. aureus et E. coli. L’incorporation de nanoparticules de ZnO, de carvacrol ou d’acide tannique lors de la réaction de réticulation permet d’améliorer les propriétés antimicrobiennes de manière significative. L’association avec des polyesters semi-cristallins biosourcés et biodégradables présente une alternative intéressante pour optimiser les performances thermomécaniques des matériaux obtenus.Un deuxième type de matériaux a été synthétisé par photo-réticulation de dérivés phénoliques époxydés comme le résorcinol ou l’eugénol. La polymérisation cationique par ouverture de cycle photoamorcée permet la synthèse de matériaux dont les propriétés mécaniques sont plus élevées que les matériaux obtenus par réaction thiol-ène, et d’autre part de s’affranchir de l’agent réticulant à base de thiol. La synthèse de différents dérivés de l’eugénol mono-époxydés offre l’avantage de pouvoir moduler la composition des matériaux obtenus qui peuvent contenir des fonctions phénol et/ou des insaturations. Les groupements phénols sont indispensables à l’activité antibactérienne et sont à l’origine des propriétés anti-oxydantes. La possibilité d’introduire des insaturations permet une post- fonctionnalisation de la surface des matériaux.Ainsi une large gamme de matériaux réticulés, biosourcés et bioactifs dont les propriétés varient de l’élastomère au thermodurcissable a été synthétisée sous irradiation / The valorization of phenolic and terpene derivatives of biomass is perfectly in line with the current challenge of our societies that drives traditional chemistry to evolve towards a sustainable chemistry. Because of their unsaturated nature, terpenes are particularly interesting for synthesizing new materials by thiol-ene chemistry. At the same time, the phenolic derivatives can easily be modified to unsaturated synthons capable of reacting in these same reactions. Thus, a wide range of materials based on linalool and eugenol has been developed under UV irradiation. An approach by photochemistry has been selected since it fits perfectly within the framework of a chemistry more respectful of the environment. The beneficial effect of the oxygenated functions of linalol and phenolic functions of eugenol on antibacterial activity was demonstrated against two bacterial strains mainly responsible for the development of nosocomial diseases: S. aureus and E. coli. The incorporation of ZnO nanoparticles, carvacrol or tannic acid during the crosslinking reaction makes it possible to improve the antimicrobial properties significantly. The association with semi-crystalline biobased and biodegradable polyesters presents an interesting alternative to optimize the thermomechanical performance of the obtained materials.A second type of materials has been synthesized by photocrosslinking epoxidized phenolic derivatives such as resorcinol or eugenol. The photoinitiated cationic polymerization by opening of the ring enables the synthesis of materials whose mechanical properties are higher than the materials obtained by thiol-ene reaction and on the other hand to get rid of the thiol-based crosslinking agent. The synthesis of various monoepoxidized eugenol derivatives offers the advantage of being able to modulate the composition of the obtained materials which may contain phenol functions and / or unsaturations. The phenol groups are essential to the antibacterial activity and lead to the antioxidant properties. The possibility of introducing unsaturations allows a post-functionalization of the surface of the materials.Thus, a wide range of crosslinked, biosourced and bioactive materials whose properties vary from elastomer to thermosetting have been synthesized under irradiation

Abstract Chlamydia pneumoniae is a common human pathogen worldwide, which causes both upper and lower respiratory tract infections. In addition, C. pneumoniae infections have been associated with atherosclerosis and other chronic diseases, and successful treatment and eradication of the organism from tissues would therefore be desirable. The purpose of this study was to assess the effects of C. pneumoniae inoculations on the development of chronic infection and atherosclerotic changes in normocholesterolemic, wild-type mice. We also aimed to elucidate the effects of antibiotic and other treatments on the eradication of chlamydia and on the reduction of the pathologic sequelae induced by these infections. Female C57BL/6J mice were fed either normal chow when assessing the effects of acute infection, or a diet supplemented with 0.2% cholesterol when evaluating the atherosclerotic changes. Primary or repeated inoculations with C. pneumoniae isolate K7 were given to the mice intranasally, and the effects of treatments with telithromycin, levofloxacin and erythromycin antimicrobial agents and with the phenolic compounds quercetin, luteolin and octyl gallate were evaluated. The following methods were used to measure infection and treatment effects and the presence of chlamydia in tissue: chlamydia culture, PCR and RT-PCR methods, histology of lung, heart and aortic tissue, serologic methods and measurements of aortic contractility responses. Repeated C. pneumoniae inoculations induced persistent chlamydial DNA and inflammation in lung tissue and development of mouse Hsp60 autoantibodies. Infection was shown to influence aortic endothelial function, and repeated inoculations significantly increased subendothelial lipid accumulation in the aortic sinus area. A flavonoid, luteolin, was shown to effectively decrease the chlamydial load and inflammatory reactions in lung tissue. All antimicrobial agents eradicated the presence of viable chlamydia effectively; however, PCR positivity persisted in lung tissue despite the treatments. Only immediate treatment after each inoculation was able to decrease aortic sinus lipid accumulation. In conclusion, these data support the role of C. pneumoniae in promoting atherosclerotic development via autoimmune responses and also via direct effects on aortic tissue. Conventional antimicrobial treatments may not effectively eradicate persistent infection, and further studies are warranted to seek for alternative treatment options.

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Good oral health has a major influence on the general quality of life and well-being. Several chronic and systemic diseases have been attributed to poor oral health. With the increasing incidence of oral diseases, the global need for alterative prevention and treatment methods and safe, effective, and economical products has expanded. There are many studies showed that Streptococcus mutans has been implicated as major etiological agent of dental caries. South African has very rich natural flora especially Cape region. Several South African medicinal plants have been used since immemorial time for treatment of different human pathologies including dental problems. The antibacterial activities of plants extracts have been recognized and documented scientifically during the last few decades. In this project we aimed at the screening of 31 South African plants randomly collected from Cape region for their antibacterial activity against Streptococcus mutans initially at two concentrations (500 and 100 µg/ml).MIC’s and MBC’s were determined for the active plant extracts, as well as the qualitative studies of the effect of the active extracts on the biofilm formation. The best or the most active safe plant (Psoralea fruticans) was submitted to chromatographic separation to isolate the bioactive compounds which could be responsible for such activity. Identification of the pure active compounds was carried out using different spectroscopic techniques. Finally the biological evaluation of the isolated pure compounds was measured against S. mutans and also the cytotoxicity studies in-vitro against normal cells lines was carried out.

Afin d'obtenir de nouveaux agents dermo-cosmétiques et thérapeutiques issus de l'utilisation traditionnelle de plantes, nous avons sélectionné cinq légumineuses au Venezuela. Trois types d'extraits ont été étudiés : aqueux, éthanolique et un dérivé protéique à partir de l'extrait aqueux. Notre objectif a été de mettre en évidence de nouvelles sources de substances actives au niveau cutané, pour le traitement de l'acné, mais aussi dans le stress oxydant et la régénération cellulaire. L'effet cytoprotecteur, la capacité de la stimulation de la croissance cellulaire, l'efficacité antioxydante vis à vis des fibroblastes dermiques 3T3, ont été analysés in vitro. L'activité antibactérienne a été évaluée envers Propionibacterium acnes, Staphylococcus epidermidis et Staphylococcus aureus, des bactéries impliquées dans le processus de l'acné. Nos résultats ont démontré que Machaerium floribundum est une plante très prometteuse, une fonction antioxydante élevée à des concentrations relativement faibles. Cette activité antioxydante est liée à la présence de tanins de type anthocyanes. Les extraits de Machaerium peuvent aussi s'inscrire dans le domaine de la régénération des tissus. Par une activité antibactérienne démontrée sur des germes impliqués dans l'acné, ils offrent une ouverture alternative pour le traitement des peaux acnéiques. / In order to obtain new dermo-cosmetic and therapeutic agents from traditional medicinal plants, highlighting new sources of active substances at the skin level, treatment of the acne, oxidative stress and cell regeneration, five Venezuelan leguminous have been selected. Three types of extracts: aqueous, ethanolic and protein derived from the aqueous extract have been studied. The cytoprotective effect, the ability of the stimulation of cell growth and antioxidant efficiency were analyzed in dermal fibroblasts 3T3 cells. Our results showed that Machaerium floribundum extracts had a very high antioxidant activity at low concentrations. This antioxidant activity is linked to the presence of condensed tannins (polymers of anthocyanins). Also a good antibacterial activity was found using Machaerium ethanolic extracts against bacteria involved in the acne process: Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus offering an alternative for acne treatment.