Tannins possessing bacteriostatic effect impair pseudomonas aeruginosa adhesion and biofilm formation

Plants produce many compounds that are biologically active, either as part of their normal program of growth and development or in response to pathogen attack or stress. Traditionally, Anadenanthera colubrina, Commiphora leptophloeos and Myracrodruon urundeuva have been used by communities in the Brazilian Caatinga to treat several infectious diseases. The ability to impair bacterial adhesion represents an ideal strategy to combat bacterial pathogenesis, because of its importance in the early stages of the infectious process; thus, the search for anti-adherent compounds in plants is a very promising alternative. This study investigated the ability of stem-bark extracts from these three species to control the growth and prevent biofilm formation of Pseudomonas aeruginosa, an important opportunistic pathogen that adheres to surfaces and forms protective biofilms. A kinetic study (0–72 h) demonstrated that the growth of extract-treated bacteria was inhibited up to 9 h after incubation, suggesting a bacteriostatic activity. Transmission electron microscopy and fluorescence microscopy showed both viable and nonviable cells, indicating bacterial membrane damage; crystal violet assay and scanning electron microscopy demonstrated that treatment strongly inhibited biofilm formation during 6 and 24 h and that matrix production remained impaired even after growth was restored, at 24 and 48 h of incubation. Herein, we propose that the identified (condensed and hydrolyzable) tannins are able to inhibit biofilm formation via bacteriostatic properties, damaging the bacterial membrane and hindering matrix production. Our findings demonstrate the importance of this abundant class of Natural Products in higher plants against one of the most challenging issues in the hospital setting: biofilm resilience

Antimicrobial activity and phytochemical screening of buchenavia tetraphylla (aubl.) R. A. Howard (combretaceae: combretoideae)

This study evaluated the antimicrobial and hemolytic activities and phytochemical constituents of hydroalcoholic extract and its fractions from Buchenavia tetraphylla leaves. Cyclohexane (BTCF), ethyl acetate (BTEF), and n-butanol-soluble (BTSBF) and non-soluble (BTNBF) fractions were obtained from a liquid-liquid partition of hydroalcoholic extract (BTHE) from B. tetraphylla leaves. The hemolytic activity of active fractions was checked. The BTHE inhibited the growth of Micrococcus luteus (MIC: 0.10 mg/mL), Pseudomonas aeruginosa (MIC: 0.20 mg/mL), Mycobacterium smegmatis (MIC: 0.39 mg/mL), Proteus vulgaris, and Staphylococcus aureus(MIC: 0.78 mg/mL for both). The more active fractions were BTCF and BTBSF. BTCF showed better potential to inhibit M. luteus (0.10 mg/mL), P. aeruginosa (0.20 mg/mL), S. enteritidis (0.39 mg/mL), and S. aureus (1.56 mg/mL). BTBSF showed the best results for M. luteus (0.10 mg/mL), M. smegmatis, B. subtilis (0.39 mg/mL for both), and P. vulgaris (0.10 mg/mL). The HC50 were greater than observed MIC: 20.30, 4.70 and 2.53 mg/mL, respectively, to BTBF, BTHE and BTCF, which. The phytochemical analysis detected the presence of flavanoids, triterpene, carbohydrate, and tannin. Our work showed for the first time the broad-spread antimicrobial activity of B. tetraphylla, which has nonhemolytic action, creating a new perspective on the interesting association of traditional and scientific knowledge

Bioactive profile of Aspidosperma pyrifolium Mart. & Zucc: An integrative review / Perfil bioativo de Aspidosperma pyrifolium Mart. & Zucc: Uma revisão integrativa

The objective of this work was to evaluate the biological potential from Aspidosperma pyrifolium Mart. & Zucc presents, through reports found in the literature. For this, articles were evaluated using compatible descriptors with the objective. As a result, it was observed that many studies have found several biological activities associated with the species

Histomorfometric Analysis of the Endochondral Ossification of the limbs of Rats submitted to Usnic Acid from Cladonia Substellata (AHTI) encapsulated in Plga-Microspheres / Análise Histomorfométrica da Ossificação Endocondral dos membros de Ratos submetidos ao Ácido Úsnico de Cladonia Substellata (AHTI) encapsulado em Microesferas de Plga

The aim of this study was to evaluate the histology and morphometry of endochondral ossification in limbs of rats submitted to usnic acid from Cladonia substellata (AHTI) encapsulated in PLGA-microspheres. It was used 12 pregnant Wistar rats that were randomly distributed in the control groups (n = 6), which received 1.0 mL of saline solution; and treated (n = 6), that received 25 mg/kg/day of encapsulated usnic acid in PLGA microspheres by oral administration. It was analyzed six fetuses from each rat under study. At the 20th day of gestation were euthanized the females and their fetuses removed for histomorphometric analysis of the anterior and posterior limbs. The results showed the epiphyseal discs of the animals with cell alterations, as in the morphology and numbers of chondrocytes. It also showed a decrease in the amount of collagen type I collagen in bone tissue. However, this study showed low toxicity of the encapsulated usnic acid on bone development, when compared to its conventional dosage form. In this way, the toxicity of usnic acid can be reduced by encapsulation in PLGA-microspheres

Trichomonicidal and parasite membrane damaging activity of bidesmosic saponins from Manilkara rufula

The infection caused by Trichomonas vaginalis is the most common but overlooked nonviral sexually transmitted disease worldwide. Treatment relies on one class of drugs, the 5- nitroimidazoles, but resistance is widespread. New drugs are urgently needed. We reported the effect of crude and purified saponin fractions of Manilkara rufula against Trichomonas vaginalis. The compound responsible for antitrichomonal activity was isolated and identified as an uncommon bidesmosic saponin, Mi-saponin C. This saponin eliminated parasite viability without toxicity against the human vaginal epithelial line (HMVII). In addition, the isolated saponin fraction improved the metronidazole effect against a metronidazole-resistant isolate and dramatically reduced the cytoadherence of T. vaginalis to human cells. Investigation of the mechanism of death showed that the saponin fraction induced the parasite death due to profound membrane damage, inducing a disturbance of intracellular content without nuclear damage. To the best of our knowledge, this is the first report of antitrichomonal activity in the bidesmosic saponins of Manilkara rufula

Differential gene expression, induced by salicylic acid and Fusarium oxysporum f. sp. lycopersici infection, in tomato

O objetivo deste trabalho foi determinar o perfi l de transcritos em plantas de tomate (Lycopersicon esculentum Mill.), durante a infecção com Fusarium oxysporum f. sp. lycopersici e após a aplicação foliarde ácido salicílico. A técnica de hibridização subtrativa por supressão (SSH) foi utilizada para gerar uma biblioteca de cDNA enriquecida por transcritos diferencialmente expressos. Foram identifi cados 307 clones,em duas bibliotecas subtrativas, que permitiram o isolamento de diversos genes de defesa com função em diferentes processos relacionados à resistência vegetal contra patógenos. Também foram isolados, nas duasbibliotecas, genes com função desconhecida, o que indica a possibilidade de identifi cação de novos genes que ainda não tenham sido relatados em estudos anteriores de resposta a estresses e defesa, em plantas. A técnica SSH é efi ciente em identifi car genes de resistência, ativados pelo ácido salicílico e pela infecção com Fusarium oxysporum f. sp. lycopersici. A aplicação dessa técnica não apenas possibilita isolar seqüências diferencialmente expressas, a baixo custo, como também permite a identifi cação de novas seqüências, em tomate, a partir de umnúmero relativamente pequeno de seqüências.The objective of this work was to determine the transcript profi le of tomato plants (Lycopersicon esculentum Mill.), during Fusarium oxysporum f. sp. lycopersici infection and after foliar application of salicylic acid. The suppression subtractive hybridization (SSH) technique was used to generate a cDNA library enriched for transcripts differentially expressed. A total of 307 clones was identifi ed in two subtractive libraries, which allowed the isolation of several defense-related genes that play roles in different mechanisms of plant resistanceto phytopathogens. Genes with unknown roles were also isolated from the two libraries, which indicates the possibility of identifying new genes not yet reported in studies of stress/defense response. The SSH technique is effective for identifi cation of resistance genes activated by salicylic acid and F. oxysporum f. sp. lycopersici infection. Not only the application of this technique enables a cost effective isolation of differentially expressed sequences, but also it allows the identifi cation of novel sequences in tomato from a relative small number ofsequences

Avaliação Ponderal e Screening Hipocrático de Camundongos Tratados Com Nerolidol / Ponderal Evaluation and Hypocratic Screening of Nerolidol Treated Mice

A natureza é uma importante fonte de novos agentes terapêuticos, com isso a quantidade de medicamentos à base de produtos naturais ou de fitoconstituintes tem aumentando cada vez mais. O nerolidol é um sesquiterpeno acíclico presente em Óleos Essenciais (OE) de diferentes espécies botânicas e é amplamente utilizado como agente aromatizante pelas indústrias alimentícias e sob o ponto de vista terapêutico possui algumas propriedades farmacológicas importantes tais como: antineoplásica, leishmanicida, ansiolítica, potencializadora para permeação de drogas terapêuticas na forma transdérmica, larvicida, antioxidante e antimicrobiana. O uso de produtos naturais e fitoconstituintes no tratamento de doenças vêm crescendo ao longo do tempo, e muitas vezes sua utilização é realizada de forma indiscriminada por grande parte da população, podendo inclusive causar sinais e sintomas de toxicidade. Para avaliar a toxicidade produzida por uma substância são realizados testes de toxicidade que resultarão em informações utilizadas para a sua classificação toxicológica. Logo, o objetivo do presente estudo foi realizar uma avaliação ponderal e screening hipocrático de camundongos tratados com o nerolidol, a fim de verificar uma possível toxicidade desse composto. A avaliação do peso e a triagem farmacológica comportamental foi realizada em camundongos machos. Um grupo recebeu a administração por via oral de 2000 mg/kg de nerolidol enquanto que o outro grupo recebeu o veículo de diluição (PBS e 10% de DMSO). Após as respectivas administrações, os camundongos foram monitorados quanto aos parâmetros comportamentais por 4h e avaliação ponderal foi realizada durante 14 dias consecutivos. Não foi observada morte dos animais, na avaliação aguda do nerolidol sobre camundongos Swiss no período de 14 dias. Da mesma forma, nenhuma alteração em relação ao screening hipocrático foi observada, sendo o comportamento do grupo tratado semelhante ao do grupo controle em ambas as doses. O ganho de peso obtido com a dose avaliada foi semelhante com o grupo controle, evidenciando que o nerolidol não demonstrou toxidez nos modelo experimental avaliado

Effects of Myroxylon peruiferum L. f. organic extracts in planktonic growth and Ralstonia solanacearum biofilm formation

Ralstonia solanacearum, a causal agent of bacterial wilt, a disease with significant negative impacts on world agriculture, presents considerable difficulties in handling due to its resistance to the common forms of control. Based on this context, the objective of this work was to investigate alternative substances for biofilm control and planktonic growth of this phytopathogen. Four organic extracts in the eluotropic series (cyclohexane, chloroform, athyl acetate, and methanol) of Myroxylon peruiferum collected in the Caatinga were evaluated for antibiofilm and antibacterial activity using the crystal violet method and antibacterial activity in microplates, considering positive values greater than 50% inhibition. The organic extracts were evaluated qualitatively by thin layer chromatography. Results obtained showed that antibiofilm activity was detected in the cyclohexanic extract, whereas ethyl acetate extract showed antibiotic activity, both in the minimum inhibitory concentration of 3 mg/mL. The evaluation presented in this study provides a database for the development of new natural phytopathogen control agents

Atividades antioxidante e inibitória da acetil colinesterase do extrato das folhas de Hymenaea rubriflora / Antioxidant and acetylcholinesterase inhbition activity from Hymenaea rubriflora Ducke (Fabaceae) leaf extract

Hymenaea rubriflora is an endemic and edible plant from tropical weather, especially present in Brazilian flora and have been reported as medicinal plant in ethnobotanical studies. There has been less previous evidence regarding its biological application, therefore, to overcome this problem the present work aimed to evaluate whether the metabolites of Hymenaea rubriflora host antioxidant and anti- acetylcholinesterase (AChE) activity. To investigate these activities a whole range of different approaches as phytochemical screening, lipidic peroxidation, DPPH scavenging and total antioxidant capacity, and acetylcholinesterase inhibition assay were used. The analysis found evidence for the presence of different secondary metabolites, among them: phenolic compounds (at 286.02 ± 1.75 GAE/mg.DW concentration), flavonoids ( at 23.19 ± 2.38 QE/mg.DW concentration), known as natural antioxidants and highlighted its effectiveness as AChE inhibitor, being able to inhibit AChE activity in 96% on 10 mg/mL. In this study we provide insights of H. rubriflora extract as an alternative antioxidant and AchE inhibitor agent, relevant to the context of neurological disorders and cognitive processes.