Cytoprotective Effect of Lygodium venustum Sw. (Lygodiaceae) against Mercurium Chloride Toxicity

Mercury is a very dangerous metal when humans come into contact with it, whether through the air or skin or by ingestion. The aim of this work was to investigate the possible effects of the ethanol extract and fractions of Lygodium venustum Sw. against mercurium chloride toxicity towards Escherichia coli strain ATCC25922. The polyphenols and flavonoids present in the extract and fractions were quantified in mg equivalent of gallic acid/g sample and mg equivalent of quercetin/g sample, respectively. The in vitro FRAP method demonstrated the antioxidant activity of the samples. The antibacterial activity of the natural products was evaluated by microdilution method and by assays to elucidate the possible cytoprotective action when combining the natural products samples and mercurium chloride, utilizing the extract and fractions at a subinhibitory concentration. The results obtained in this work indicate that the ethanol extract and fractions of L. venustum are an alternative source of natural products with cytoprotective action, where this protection is correlated with antioxidant and chelating activity, due to the presence of total phenols and flavonoids

Effect of seasonality on chemical profile and antifungal activity of essential oil isolated from leaves Psidium salutare (Kunth) O. Berg

Medicinal plants play a crucial role in the search for components that are capable of neutralizing the multiple mechanisms of fungal resistance. Psidium salutare (Kunth) O. Berg is a plant native to Brazil used as both food and traditional medicine to treat diseases and symptoms such as stomach ache and diarrhea, whose symptoms could be related to fungal infections from the genus Candida. The objective of this study was to investigate the influence of seasonal variability on the chemical composition of the Psidium salutare essential oil, its antifungal potential and its effect on the Candida albicans morphogenesis. The essential oils were collected in three different seasonal collection periods and isolated by the hydrodistillation process in a modified Clevenger apparatus with identification of the chemical composition determined by gas chromatography coupled to mass spectrometry (GC/MS). The antifungal assays were performed against Candida strains through the broth microdilution method to determine the minimum fungicidal concentration (MFC). Fungal growth was assessed by optical density reading and the Candida albicans dimorphic effect was evaluated by optical microscopy in microculture chambers. The chemical profile of the essential oils identified 40 substances in the different collection periods with γ-terpinene being the predominant constituent. The antifungal activity revealed an action against the C. albicans, C. krusei and C. tropicalis strains with an IC50 ranging from 345.5 to 2,754.2 µg/mL and a MFC higher than 1,024 µg/mL. When combined with essential oils at sub-inhibitory concentrations (MIC/16), fluconazole had its potentiated effect, i.e. a synergistic effect was observed in the combination of fluconazole with P.salutare oil against all Candida strains; however, for C. albicans, its effect was reinforced by the natural product in all the collection periods. The results show that the Psidium salutare oil affected the dimorphic transition capacity, significantly reducing the formation of hyphae and pseudohyphae in increasing concentrations. The results show that P. salutare oil exhibits a significant antifungal activity against three Candida species and that it can act in synergy with fluconazole. These results support the notion that this plant may have a potential use in pharmaceutical and preservative products

Menadione (vitamin K) enhances the antibiotic activity of drugs by cell membrane permeabilization mechanism

Menadione, vitamin K3, belongs to the class of lipid-soluble vitamins and lipophilic substances as menadione cause disturbances in the bacterial membrane, resulting in damage to the fundamental elements for the integrity of the membrane, thus allowing increased permeability. Accordingly, the aim of this study was to evaluate in vitro the antibiotic-modifying activity of menadione in multiresistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, with a gradual increase in its subinhibitory concentration. In addition, menadione was compared with cholesterol and ergosterol for similarity in mechanism of drug modulatory action. Antibiotic-modifying activity and antibacterial effect were determined by the broth microdilution assay. Menadione, cholesterol and ergosterol showed modulatory activity at clinically relevant concentrations, characterizing them as modifiers of bacterial drug resistance, since they lowered the MIC of the antibiotics tested. This is the first report of the antibacterial activity of menadione and its potentiation of aminoglycosides against multiresistant bacteria

Phytochemical Analysis and Modulation of Antibiotic Activity by Luehea paniculata Mart. & Zucc. (Malvaceae) in Multiresistant Clinical Isolates of Candida Spp.

The high incidence of fungal infections has led to the continuous search for new drugs. Extracts of Luehea paniculata, a tree of multiple medicinal uses, were evaluated for anti-Candida activity, as well as its modulator potential of the Fluconazole antibiotic. Chemical prospecting of ethanol extracts of leaf and bark was carried out, the quantification of total phenols and flavonoids, characterized by the HPLC-DAD technique. The rosmarinic acid and the vitexin flavonoid were observed as major constituents in ELELP and ESWELP, respectively. Antioxidant activity was also evaluated by the method of scavenging the free radical DPPH, and quercetin was used as standard, obtaining IC50 values: 0.341 (mg/mL) for ELELP and 0.235 (mg/mL) for ESWELP. The microdilution assay was performed for antifungal activity against strains of Candida albicans, C. krusei, and C. tropicalis and showed minimum inhibitory concentrations values ≥1024 μg/mL. In the modulator action of extracts on Fluconazole against multiresistant clinical isolates of Candida (subinhibitory concentration minimum of 128 μg/mL), a significant synergism was observed, indicating that the extracts potentiated the antifungal effect against C. tropicalis, where antioxidant flavonoids could be responsible. This is the first report about modifying activity of the antibiotic action of a species of the genus Luehea

Fern extracts potentiate fluconazole activity and inhibit morphological changes in Candida species

Objective: To investigate the antifungal activity of the fern species Lygodium venustum (L. venustum) and Pityrogramma calomelanos (P. calomelanos) against Candida albicans and Candida tropicalis strains. Methods: The microdilution method was used to evaluate the antifungal activity, as well as the modulating effects of ethanolic extracts of these plants in combination with fluconazole. The minimum inhibitory concentration (MIC), minimum fungicide concentration and morphological changes were also determined. Results: The extract obtained from L. venustum presented a MIC > 8192 μg/mL, while the extract obtained from and P. calomelanos presented a MIC = 8192 μg/mL, indicating that they present weak antifungal activity. However, combination of the extracts with Fluconazole potentiated the antifungal activity of this drug. At different experimental conditions, such as concentration of the extract and type of strain, the extracts inhibited hyphae and pseudohyphae formation, indicating that these fern species can affect the morphology of the fungi. Conclusions: The extracts obtained from the fern species L. venustum and P. calomelanos dose not present significant antifungal activity. However, P. calomelanos potentiates the activity of fluconazole and both extracts inhibits the morphological changes in Candida species, indicating that they have potential pharmacological activity as modulators of fungal biology. Therefore, novel studies are required to characterize the interference of these extracts in the virulence and pathogenicity of Candida species as well as the potential of fern species to treat fungal infections

Efeito da utilização de Butil-Hidroxianizol como agente antioxidante em biodiesel de óleos residuais

Um dos desafios a serem superados nos próximos anos, buscando ampliar a utilização de biodiesel no mercado brasileiro, trata da sua estabilidade à oxidação. Pela sua composição química, o biodiesel oxida-se quando em contato com o ar ou submetido à ação do calor, provocando variação de parâmetros como viscosidade cinemática, índice de acidez e índice de peróxidos. Desta forma, o presente trabalhou buscou atender à esta demanda a partir da aplicação de butil-hidroxianizol como agente antioxidante em biodiesel produzido a partir de óleos e gorduras residuais. Durante quatro semanas, foram avaliadas quatro concentrações deste antioxidante no biodiesel: 250, 500, 750 e 1000 ppm. Para acompanhar a evolução da oxidação do combustível, foi monitorado o seu índice de peróxido. Os resultados mostraram que a concentração de 1000 ppm se mostrou mais eficaz que as demais no controle da formação de peróxidos durante os ensaios, indicando maior capacidade de controlar a oxidação do combustível. Por fim, foi determinada a estabilidade à oxidação do biodiesel sem adição de butil-hidroxianizol e com a adição deste produto na concentração de 1000 ppm. Os resultados mostraram um aumento superior à 700 % na estabilidade à oxidação do biodiesel pelo uso deste antioxidante nesta concentração, corroborando os resultados obtidos a partir do monitoramento do índice de peróxido

Action of cholecalciferol and alpha-tocopherol on Staphylococcus aureus efflux pumps

Submitted by Adagilson Silva ([email protected]) on 2017-06-13T19:43:53Z No. of bitstreams: 1 27298617 2016 tin-act.pdf: 373418 bytes, checksum: 5674ad4d8b062cd367d34169f62a13a0 (MD5)Approved for entry into archive by Adagilson Silva ([email protected]) on 2017-06-13T19:44:14Z (GMT) No. of bitstreams: 1 27298617 2016 tin-act.pdf: 373418 bytes, checksum: 5674ad4d8b062cd367d34169f62a13a0 (MD5)Made available in DSpace on 2017-06-13T19:44:14Z (GMT). No. of bitstreams: 1 27298617 2016 tin-act.pdf: 373418 bytes, checksum: 5674ad4d8b062cd367d34169f62a13a0 (MD5) Previous issue date: 2016Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Federal da Paraíba. Laboratório de Microrganismos Genéticos. João Pessoa, PB, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Federal de Pernambuco. Laboratório de Bioinformática e Biologia Evolucionária. Departamento de Genética. Recife, PE, Brazil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Microbiologia. Recife, PE, Brasil.Centro Universitário UniLeão Sampaio. Juazeiro do Norte, CE, Brasil.Universidade Federal de Sergipe. Aracaju, SE, Brasil.Alpha-tocopherol is one the most abundant and biologically active isoforms of vitamin E. This compound is a potent antioxidant and one of most studied isoforms of vitamin E. Vitamin D3 (cholecalciferol) is an important nutrient for calcium homeostasis and bone health, that has also been recognized as a potent modulator of the immune response. Methicillin-resistant Staphylococcus aureus (MRSA) is the most important causative agent of both nosocomial and community-acquired infections. The aim of this study was to evaluate the inhibitory effect of alpha-tocopherol and cholecalciferol on both S. aureus and multidrug resistant S. aureus efflux pumps. The RN4220 strain has the plasmid pUL5054 that is the carrier of gene that encodes the macrolide resistance protein (an efflux pump) MsrA; the IS-58 strain possesses the TetK tetracycline efflux protein in its genome and the 1199B strain resists to hydrophilic fluoroquinolones via a NorA-mediated mechanism. The antibacterial activity was evaluated by determining the Minimal Inhibitory Concentration (MIC) and a possible inhibition of efflux pumps was associated to a reduction of the MIC. In this work we observed that in the presence of the treatments there was a decrease in the MIC for the RN4220 and IS-58 strains, suggesting that the substances presented an inhibitory effect on the efflux pumps of these strains. Significant efforts have been done to identify efflux pump inhibitors (EPIs) from natural sources and, therefore, the antibacterial properties of cholecalciferol and alpha-tocopherol might be attributed to a direct effect on the bacterial cell depending on their amphipathic structure

Phytochemicals from fern species: potential for medicine applications

Ferns are an important phytogenetic bridge between lower and higher plants. Historically they have been used in many ways by humans, including as ornamental plants, domestic utensils, foods, and in handicrafts. In addition, they have found uses as medicinal herbs. Ferns produce a wide array of secondary metabolites endowed with different bioactivities that could potentially be useful in the treatment of many diseases. However, there is currently relatively little information in the literature on the phytochemicals present in ferns and their pharmacological applications, and the most recent review of the literature on the occurrence, chemotaxonomy and physiological activity of fern secondary metabolites was published over 20 years ago, by Soeder (Bot Rev 51:442\u2013536, 1985). Here, we provide an updated review of this field, covering recent findings concerning the bioactive phytochemicals and pharmacology of fern species