1,130 research outputs found
Rose geranium essential oil as a source of new and safe anti-inflammatory drugs
Background: Since the available anti-inflammatory drugs exert an extensive variety of side effects, the search for new anti-inflammatory agents has been a priority of pharmaceutical industries.Aims: The aim of the present study was to assess the anti-inflammatory activities of the essential oil of rose geranium (RGEO).Methods: The chemical composition of the RGEO was investigated by gas chromatography. The major components were citronellol (29.13%), geraniol (12.62%), and citronellyl formate (8.06%). In the carrageenaninduced paw edema, five different groups were established and RGEO was administered orally in three different doses.Results: RGEO (100 mg/kg) was able to significantly reduce the paw edema with a comparable effect to that observed with diclofenac, the positive control. In addition, RGEO showed a potent anti-inflammatory activity by topical treatment in the method of croton oil-induced ear edema. When the dose was 5 or 10 ml of RGEO per ear, the inflammation was reduced by 73 and 88%, respectively. This is the first report to demonstrate a significant anti-inflammatory activity of Algerian RGEO. In addition, histological analysis confirmed that RGEO inhibited the inflammatory responses in the skin.Conclusion: Our results indicate that RGEO may have significant potential for the development of novel antiinflammatory drugs with improved safety profile.Keywords: essential oils; rose geranium; citronellol; anti-inflammatory effect; skin inflammation; histopathology; carrageenan; croto
Lemon grass (Cymbopogon citratus) essential oil as a potent anti-inflammatory and antifungal drugs
Background: Volatile oils obtained from lemon grass [Cymbopogon citratus (DC.) Stapf, Poaceae family] are used in traditional medicine as remedies for the treatment of various diseases.Aims: In the present study, lemon grass essential oil (LGEO) was evaluated for its in vivo topical and oral antiinflammatory effects, and for its in vitro antifungal activity using both liquid and vapor phases.Methods:The chemical profile ofLGEOas determined bygas chromatography-mass spectrometry analysis revealed twomajor components: geranial (42.2%), and neral (31.5%). The antifungal activity of LGEOwas evaluated against several pathogenic yeasts and filamentous fungi using disc diffusion and vapor diffusion methods.Results: LGEO exhibited promising antifungal effect against Candida albicans, C. tropicalis, and Aspergillus niger, with different inhibition zone diameters (IZDs) (35-90 mm). IZD increased with increasing oil volume. Significantly, higher anti-Candida activity was observed in the vapor phase. For the evaluation of the antiinflammatory effect, LGEO (10 mg/kg, administered orally) significantly reduced carrageenan-induced paw edema with a similar effect to that observed for oral diclofenac (50 mg/kg), which was used as the positive control. Oral administration of LGEO showed dose-dependent anti-inflammatory activity. In addition, topical application of LGEO in vivo resulted in a potent anti-inflammatory effect, as demonstrated by using the mouse model of croton oil-induced ear edema. To our knowledge, this is the first such report to be published. The topical application of LGEO at doses of 5 and 10 mL/ear significantly reduced acute ear edema induced by croton oil in 62.5 and 75% of the mice, respectively. In addition, histological analysis clearly confirmed that LGEO inhibits the skin inflammatory response in animal models.Conclusion: Results of the present study indicate that LGEO has a noteworthy potential for the development of drugs for the treatment of fungal infections and skin inflammation that should be explored in future studies.Keywords: lemon grass; essential oil; antifungal activity; anti-inflammatory effect; citral; aromatherap
Solvent-free microwave extraction of essential oil from aromatic herbs: From laboratory to pilot and industrial scale
Natural coagulates for wastewater treatment; a review for application and mechanism
The increase of water demand and wastewater generation is among the global concerns in the world. The less effective management of water sources leads to serious consequences, the direct disposal of untreated wastewater is associated with the environmental pollution, elimination of aquatic life and the spread of deadly epidemics. The flocculation process is one of the most important stages in water and wastewater treatment plants, wherein this phase the plankton, colloidal particles, and pollutants are precipitated and removed. Two major types of coagulants are used in the flocculation process included the chemical and natural coagulants. Many studies have been performed to optimize the flocculation process while most of these studies have confirmed the hazardous effects of chemical coagulants utilization on the ecosystem. This chapter reviews a summary of the coagulation/flocculation processes using natural coagulants as well as reviews one of the most effective natural methods of water and wastewater treatment
Escherichia coli mar and acrAB Mutants Display No Tolerance to Simple Alcohols
The inducible Mar phenotype of Escherichia coli is associated with increased tolerance to multiple hydrophobic antibiotics as well as some highly hydrophobic organic solvents such as cyclohexane, mediated mainly through the AcrAB/TolC efflux system. The influence of water miscible alcohols ethanol and 1-propanol on a Mar constitutive mutant and a mar deletion mutant of E. coli K-12, as well as the corresponding strains carrying the additional acrAB deletion, was investigated. In contrast to hydrophobic solvents, all strains were killed in exponential phase by 1-propanol and ethanol at rates comparable to the parent strain. Thus, the Mar phenotype does not protect E. coli from killing by these more polar solvents. Surprisingly, AcrAB does not contribute to an increased alcohol tolerance. In addition, sodium salicylate, at concentrations known to induce the mar operon, was unable to increase 1-propanol or ethanol tolerance. Rather, the toxicity of both solvents was increased in the presence of sodium salicylate. Collectively, the results imply that the resilience of E. coli to water miscible alcohols, in contrast to more hydrophobic solvents, does not depend upon the AcrAB/TolC efflux system, and suggests a lower limit for substrate molecular size and functionality. Implications for the application of microbiological systems in environments containing high contents of water miscible organic solvents, e.g., phage display screening, are discussed
Mechanism of periodic height variations along self-aligned VLS-grown planar nanostructures
In this study we report in-plane nanotracks produced by molecular-beam-epitaxy (MBE) exhibiting lateral self-assembly and unusual periodic and out-of-phase height variations across their growth axes. The nanotracks are synthesized using bismuth segregation on the GaAsBi epitaxial surface, which results in metallic liquid droplets capable of catalyzing GaAsBi nanotrack growth via the vapor–liquid–solid (VLS) mechanism. A detailed examination of the nanotrack morphologies is carried out employing a combination of scanning electron and atomic force microscopy and, based on the findings, a geometric model of nanotrack growth during MBE is developed. Our results indicate diffusion and shadowing effects play significant roles in defining the interesting nanotrack shape. The unique periodicity of our lateral nanotracks originates from a rotating nucleation “hot spot” at the edge of the liquid–solid interface, a feature caused by the relative periodic circling of the non-normal ion beam flux incident on the sample surface, inside the MBE chamber. We point out that such a concept is divergent from current models of crawling mode growth kinetics and conclude that these effects may be utilized in the design and assembly of planar nanostructures with controlled non-monotonous structure
Post-primary education in West Ham, 1918-39.
This thesis is concerned with post-primary education in West Ham 1918-39, with
particular reference to secondary education. The realities of local educational
experience are set against a background of educational acts an economies. The
economic difficulties of the 1920s and the Depression of the 1930s were keenly felt
in West Ham despite the efforts of the predominantly Labour council to mitigate
poverty. A gap sometimes existed between the educational opportunities Labour
councillors wished to provide and those they were able to provide. Generally a
pragmatic approach was taken and certainly a secondary education was not seen as
essential for all.
Chapter One outlines West Ham's pre-1918 history and growth with reference to
local politics and immigrant and religious groupings. West Ham's interwar history
is told in greater detail. Chapter Two relates the difficulties encountered by the
West Ham Education Committee in its decision to establish compulsory
continuation schools, not least from the parents of West Ham. West Ham was one
of the few areas in the country which succeeded in implementing compulsory
continuation education albeit for a limited period. A section on technical education
is also included in this chapter, although detailed treatment is hampered by a
scarcity of records.
Chapter Three examines West Ham's secondary school scholarships in the context
of the national situation. West Ham's higher elementary/central school scholarships
are subjected to the same scrutiny. Each of West Ham's secondary schools shared
a broadly similar curriculum and ethos. Chapter Four highlights these similarities
but also points out differences. Of the five interwar secondary schools, two
catered for girls, one for boys and two were mixed. Two of the secondary schools
were Catholic institutions, although both accepted non-Catholic pupils. Three of
the schools were aided and two municipal. A section is included on West Ham's
higher elementary/central schools but records are less full than those for the secondary schools. Chapter Five compares and contrasts West Ham's interwar
secondary school system with that in East Ham, its sister borough. Chapter Six
discusses both the economic and cultural factors underlying local attitudes to
post-compulsory schooling. The main conclusions drawn relate to these attitudes
which militated against any easy acceptance of such education as necessarily
beneficial
The TolC Protein of Legionella pneumophila Plays a Major Role in Multi-Drug Resistance and the Early Steps of Host Invasion
Pneumonia associated with Iegionnaires's disease is initiated in humans after inhalation of contaminated aerosols. In the environment, Legionella pneumophila is thought to survive and multiply as an intracellular parasite within free-living amoeba. In the genome of L. pneumophila Lens, we identified a unique gene, tolC, encoding a protein that is highly homologous to the outer membrane protein TolC of Escherichia coli. Deletion of tolC by allelic exchange in L. pneumophila caused increased sensitivity to various drugs. The complementation of the tolC mutation in trans restored drug resistance, indicating that TolC is involved in multi-drug efflux machinery. In addition, deletion of tolC caused a significant attenuation of virulence towards both amoebae and macrophages. Thus, the TolC protein appears to play a crucial role in virulence which could be mediated by its involvement in efflux pump mechanisms. These findings will be helpful in unraveling the pathogenic mechanisms of L. pneumophila as well as in developing new therapeutic agents affecting the efflux of toxic compounds
Identification of functional elements and regulatory circuits by Drosophila modENCODE
To gain insight into how genomic information is translated into cellular and developmental programs, the Drosophila model organism Encyclopedia of DNA Elements (modENCODE) project is comprehensively mapping transcripts, histone modifications, chromosomal proteins, transcription factors, replication proteins and intermediates, and nucleosome properties across a developmental time course and in multiple cell lines. We have generated more than 700 data sets and discovered protein-coding, noncoding, RNA regulatory, replication, and chromatin elements, more than tripling the annotated portion of the Drosophila genome. Correlated activity patterns of these elements reveal a functional regulatory network, which predicts putative new functions for genes, reveals stage- and tissue-specific regulators, and enables gene-expression prediction. Our results provide a foundation for directed experimental and computational studies in Drosophila and related species and also a model for systematic data integration toward comprehensive genomic and functional annotation
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