The n-hexane extract of the stem bark of Croton anisodontus yielded 2-hydroxy-3,4,6-trimethoxyacetophenone, a well-known substance, but isolated from this species for the first time. The ...antimicrobial and modulatory activities of the compound towards Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, C krusei and C tropicalis strains were assessed. Antibiotics such as amikacin, gentamicin and neomycin were used in a subinhibitory concentration. Significant activity was observed towards P. aeruginosa and S. aureus 358, with p < 0.001 in association with amikacin. The present results place C anisodontus as an alternative source of 2-hydroxy-3,4,6-trimethoxyacetophenone with antibacterial potential.
Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder that belongs to a group of conditions called laminopathies which affect nuclear lamins. Mutations in two genes, LMNA and ...ZMPSTE24, have been found in patients with HGPS. The p.G608G LMNA mutation is the most commonly reported mutation. The aim of this work was to compile a comprehensive literature review of the clinical features and genetic mutations and mechanisms of this syndrome as a contribution to health care workers. This review shows the necessity of a more detailed clinical identification of Hutchinson-Gilford progeria syndrome and the need for more studies on the pharmacologic and pharmacogenomic approach to this syndrome.
In this paper we analyzed the effect size and frequency of Brazilian discontinued operations as well as the managers’ justifications presented in the current and annual reports for discontinued ...operations. Our study comprises the analysis of 191 discontinued operations disclosed by Brazilian companies after the IFRS adoption, for the period from 2010 to June 2016. We hand-collected the reasons for discontinued operations based on management’s explanations provided in the current and annual reports. We performed a qualitative (content analysis) and quantitative (contingency table and nonparametric statistical tests) data analysis. Consistent with the Theory of Corporate Scandals, our results show that there was no evidence that Brazilian companies made opportunistic decisions to discontinue operations in order to increase their core income. Our study extends the literature in two ways: first, by providing new evidence about the impacts of IFRS 5 adoption in a developing market; second, by showing that adopting the forward-looking approach based on managers’ intention does not relate to opportunistic decisions.
Neste estudo, analisamos a magnitude e frequência das operações descontinuadas, bem como as justificativas apresentadas pelos administradores brasileiros nos relatórios anuais e fatos relevantes para classificar tais operações. O estudo compreende a análise de 191 operações descontinuadas divulgadas por empresas brasileiras, após a adoção das IFRS, no período de 2010 a junho de 2016. Realizamos uma análise qualitativa (análise de conteúdo) e quantitativa (tabela de contingência e testes estatísticos não paramétricos) dos dados coletados. Assim como sugerido pela Teoria dos Escândalos Corporativos, nossos resultados demostram que não há evidências de que as empresas brasileiras tomaram decisões oportunistas para aumentar o resultado das operações continuadas. Nosso estudo amplia a literatura de duas maneiras. Primeiro, fornece novas evidências sobre os impactos de adotar as IFRS 5 em um mercado em desenvolvimento. Segundo, demostra que a adoção da abordagem orientada para o futuro, aplicada no IFRS 5, não está associada a decisões oportunistas.
En este estudio, analizamos la magnitud y frecuencia de las operaciones discontinuas, así como las justificaciones presentadas por los administradores brasileños en los informes anuales y en hechos relevantes para la clasificación de las operaciones discontinuadas. El estudio comprende el análisis de 191 operaciones discontinuadas divulgadas por empresas brasileñas, después de la adopción del IFRS, en el período de 2010 a junio de 2016. Hemos hecho un análisis cualitativo (análisis de contenido) y cuantitativo (tabla de contingencia y pruebas estadísticas no paramétricas) de los datos recolectados. Así como sugerido por la Teoría de los escándalos corporativos, nuestros resultados demuestran que no hay evidencias de que las empresas brasileñas tomaron decisiones oportunistas para aumentar el resultado de las operaciones continuadas. Nuestro estudio amplía la literatura de dos maneras. Primero, proporciona nuevas evidencias sobre los impactos de la adopción del IFRS 5 en un mercado en desarrollo. Segundo, demuestra que la adopción del enfoque orientado hacia el futuro, aplicado en el IFRS 5, no está asociada a decisiones oportunistas.
Peptides and proteins with antimicrobial activity Coutinho, Henrique Douglas Melo; Lobo, Katiuscia Menezes; Bezerra, Denise Aline Casimiro ...
Indian journal of pharmacology,
01/2008, Letnik:
40, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The increase of microbial resistance to antibiotics has led to a
continuing search for newer and more effective drugs. Antimicrobial
peptides are generally found in animals, plants, and ...microorganisms and
are of great interest to medicine, pharmacology, and the food industry.
These peptides are capable of inhibiting pathogenic microorganisms.
They can attack parasites, while causing little or no harm to the host
cells. The defensins are peptides found in granules in the
polymorphonuclear neutrophils (PMNs) and are responsible for the
defense of the organism. Several animal defensins, like dermaseptin,
antileukoprotease, protegrin, and others, have had their activities and
efficacy tested and been shown to be effective against bacteria, fungi,
and protists; there are also specific defensins from invertebrates,
e.g., drosomycin and heliomicin; from plants, e.g., the types A and B;
and the bacteriocins, e.g., acrocin, marcescin, etc. The aim of the
present work was to compile a comprehensive bibliographic review of the
diverse potentially antimicrobial peptides in an effort to systematize
the current knowledge on these substances as a contribution for further
researches. The currently available bibliography does not give a
holistic approach on this subject. The present work intends to show
that the mechanism of defense represented by defensins is promising
from the perspective of its application in the treatment of infectious
diseases in human, animals and plants.
Bacterial infectious agents present a risk to populations, as they are responsible for high morbidity and mortality. For combating these pathogens, our main line of defense is the use of antibiotics. ...However, indiscriminate use of these drugs develops resistant strains to these same drugs. The present study has tested the antibacterial and modifying antibiotic activity of natural products from Nasutitermes corniger (Termitidae) (Motschulsky), a termite used in folk medicine in Northeast Brazil, by the microdilution and checkerboard methods, respectively. In this study, the aqueous extract from the nest of N. corniger (ANCE) was prepared and tested with chlorpromazine (CPZ) for its antimicrobial activity, using the microdilution method. CPZ and ANCE were used independently and also in combination with aminoglycosides, against a strain of Escherichia coli resistant to these antibiotics, to determine the participation of efflux systems in resistance mechanisms. The fractional inhibitory concentration (FIC) index was calculated and evaluated for the occurrence of synergism, using the checkerboard method. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) values were >/= 2048 mug/mL for both strains of E. coli assayed, indicating low antibacterial activity. However, synergism was observed with kanamycin when the decoction was used, but when chlorpromazine was used, synergism was observed with kanamycin, amikacin, and neomycin. This synergism with CPZ indicated the involvement of an efflux system in the resistance to these aminoglycosides. Therefore, it was suggested that the natural products from N. corniger could be used as a source of zoo-derived natural products with kanamycin-modifying activity, resulting in a new approach against bacterial resistance to antibiotics.
The survival and spreading of resistant bacterial strains has boosted research which focusses on discovering new antimicrobial agents derived from plant species. Several studies have demonstrated ...that substances present in plant extracts can modify the activity of antibiotics, increasing their efficacy. Species of the genus Psidium have been popularly used to treat bacterial infections. However, their modulatory effect on antibiotic activity remains to be elucidated. The aim of this study was to evaluate the modulatory effect of the hydroalcoholic extracts obtained from the leaves of Psidium guajava L. and Psidium brownianum Mart ex DC on bacterial proliferation, both separately and in combination with antibiotics.
The assays were performed using the microdilution method. The minimum inhibitory concentration (MIC) of the extracts and drugs were determined against standard and clinical isolates of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. To verify the potentiation of the antibiotic activity, the MIC of the antibiotics were determined alone and in association with the extracts.
The extracts of P. guajava and P. brownianum did not present clinically significant activity against the Gram negative bacteria evaluated, with MIC values against S. aureus of 256 and 512μg/mL, respectively. However, when combined at sub-inhibitory concentrations with antibiotics, both extracts presented significantly synergistic effects.
Our results demonstrated the effectiveness of P. guajava and P. brownianum on modulating bacterial growth, suggesting that these natural products might be used in drug development in association with antibiotics, reducing bacterial resistance and thus, improving the treatment of bacterial infections.
Oral diseases, including caries and periodontal disease, are especially of concern to public health, where they affect a large part of the population, leading dental professionals to seek ...alternatives for their control. The aim of this work was to evaluate the chemical composition and antibacterial activity of the essential oil of Plectranthus amboinicus Lour (malvariço), a plant used by the local population for the treatment of diseases of the oral cavity, alone or as a mouthwash against a strain of Streptococcus mutans.
The essential oil obtained from the malvariço plant, obtained from two locations, was characterized by gas chromatography and evaluated for antibiotic activity. The essential oil was also tested for antibacterial-modifying activity in combination with mouthwash to determine any synergistic or antagonistic effect.
The yield of the essential oils extracted from plants from Fortaleza was higher than that extracted from Crato plants (0.25 and 0.15%, respectively). The two samples of essential oil exhibited significant differences in composition, where the major compounds, carvacrol and germacrene D, varied. Antibacterial activity in the two samples was low or not detectable. The essential oil combined with mouthwash was effective in inhibiting bacterial growth, but this result was lower than with chlorhexidine alone (p<0.05).
Our results demonstrated an antagonistic effect resulting from the association between the essential oil and mouthwash, indicating that this combination must be avoided and demonstrating the necessity of more studies about these combinations.
The aim of this study was to identify and evaluate the chemical compositions and effects of the
leaf and root hydroalcoholic extracts (HELST and HERST) against different strains of
. Chemical ...analysis was performed by Ultra-Performance Liquid Chromatography Coupled to Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF). The Inhibitory Concentration of 50% of the growth (IC
as well as the intrinsic and combined action of the extracts with the antifungal fluconazole (FCZ) were determined by the microdilution method while the minimum fungicidal concentrations (MFCs) and the effect on fungal morphological transitions were analyzed by subculture and in humid chambers, respectively. From the preliminary phytochemical analysis, the phenols and flavonoids were the most abundant. The intrinsic IC
values for HELST ranged from 5716.3 to 7805.8 µg/mL and from 6175.4 to 51070.9 µg/mL for the HERST, whereas the combination of the extracts with fluconazole presented IC
values from 2.65 to 278.41 µg/mL. The MFC of the extracts, individually, for all the tested strains was ≥16384 µg/mL. When fluconazole was combined with each extract, the MFC against CA URM 5974 was reduced (HELST: 2048 and HERST: 4096 µg/mL). Synergism was observed against standard
(CA) and
(CT) strains and with the root extract against the CT isolate. The leaf extract inhibited the morphological transition of all strains while the root extract inhibited only CT strains.
Sexually transmitted diseases (STDs) are produced by pathogens like bacteria, fungi, parasites, and viruses, and may generate severe health problems such as cancer, ulcers, and even problems in the ...newborn. This narrative review aims to present updated information about the use of natural bioactive compounds for the prevention and treatment of sexually transmitted infections. A search of the literature was performed using databases and search engines such as PubMed, Scopus, Google Scholar and Science Direct. From the pharmacotherapeutic management point of view, any strategies for prevention should contain medical approaches. The bioactive compounds obtained from natural products have shown biological effects against different microorganisms for the treatment of these diseases. The main results showed antimicrobial, antiprotozoal, antifungal and antiviral effects such as HIV. Also, the molecular mechanisms, signalling pathways and action targets of natural compounds were highlighted, thus justifying bacterial and antifungal inhibition, apoptosis or reduction of viral replication. From the data of our study, we can conclude that natural compounds may be a significant source for adjuvant drugs / complementary therapies in the treatment of STDs. With all these benefits, the future must conduct extensive clinical trials and the development of pharmaceutical nanotechnologies for a greater therapeutic effect.
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