Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Mais filtros










Intervalo de ano de publicação
2.
JMIR Aging ; 6: e41185, 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37733406

RESUMO

BACKGROUND: Informal carers play a major role in supporting relatives and friends who are sick, disabled, or frail. Access to information, guidance, and support that are relevant to the lives and circumstances of carers is critical to carers feeling supported in their role. When unmet, this need is known to adversely affect carer resilience and well-being. To address this problem, Care Companion was co-designed with current and former carers and stakeholders as a free-to-use, web-based resource to provide access to a broad range of tailored information, including links to local and national resources. OBJECTIVE: This study aimed to investigate the real-world uptake and use of Care Companion in 1 region of England (with known carer population of approximately 100,000), with local health, community, and social care teams being asked to actively promote its use. METHODS: The study had a convergent parallel, mixed methods design and drew on the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework. Data included metrics from carers' use of Care Companion, surveys completed by users recruited through general practice, and interviews with carers and health and social care providers regarding their views about Care Companion and their response to it. Quantitative data were analyzed using descriptive statistics. Interview data were analyzed thematically and synthesized to create overarching themes. The qualitative findings were used for in-depth exploration and interpretation of quantitative results. RESULTS: Despite awareness-raising activities by relevant health, social care, and community organizations, there was limited uptake with only 556 carers (0.87% of the known carer population of 100,000) registering to use Care Companion in total, with median of 2 (mean 7.2; mode 2) visits per registered user. Interviews with carers (n=29) and stakeholders (n=12) identified 7 key themes that influenced registration, use, and perceived value: stakeholders' signposting of carers to Care Companion, expectations about Care Companion, activity levels and conflicting priorities, experience of using Care Companion, relevance to personal circumstances, social isolation and networks, and experience with digital technology. Although many interviewed carers felt that it was potentially useful, few considered it as being of direct relevance to their own circumstances. For some, concerns about social isolation and lack of hands-on support were more pressing issues than the need for information. CONCLUSIONS: The gap between the enthusiastic views expressed by carers during Care Companion's co-design and the subsequent low level of uptake and user experience observed in this evaluation suggests that the co-design process may have lacked a sufficiently diverse set of viewpoints. Numerous factors were identified as contributing to Care Companion's level of use, some of which might have been anticipated during its co-design. More emphasis on the development and implementation, including continuing co-design support after deployment, may have supported increased use.

3.
Int J Mol Sci ; 23(14)2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35887325

RESUMO

Antimicrobial peptides (AMPs) are naturally occurring compounds which possess a rapid killing mechanism and low resistance potential. Consequently, they are being viewed as potential alternatives to traditional antibiotics. One of the major factors limiting further development of AMPs is off-target toxicity. Enhancements to antimicrobial peptides which can maximise antimicrobial activity whilst reducing mammalian cytotoxicity would make these peptides more attractive as future pharmaceuticals. We have previously characterised Smp24, an AMP derived from the venom of the scorpion Scorpio maurus palmatus. This study sought to better understand the relationship between the structure, function and bacterial selectivity of this peptide by performing single amino acid substitutions. The antimicrobial, haemolytic and cytotoxic activity of modified Smp24 peptides was determined. The results of these investigations were compared with the activity of native Smp24 to determine which modifications produced enhanced therapeutic indices. The structure-function relationship of Smp24 was investigated by performing N-terminal, mid-chain and C-terminal amino acid substitutions and determining the effect that they had on the antimicrobial and cytotoxic activity of the peptide. Increased charge at the N-, mid- and C-termini of the peptide resulted in increased antimicrobial activity. Increased hydrophobicity at the N-terminus resulted in reduced haemolysis and cytotoxicity. Reduced antimicrobial, haemolytic and cytotoxic activity was observed by increased hydrophobicity at the mid-chain. Functional improvements have been made to modified peptides when compared with native Smp24, which has produced peptides with enhanced therapeutic indices.


Assuntos
Anti-Infecciosos , Venenos de Escorpião , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos , Bactérias Gram-Negativas , Hemólise , Mamíferos , Testes de Sensibilidade Microbiana , Venenos de Escorpião/química , Venenos de Escorpião/farmacologia , Escorpiões , Índice Terapêutico
4.
Curr Opin Biotechnol ; 76: 102729, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35525176

RESUMO

In this review, we offer our opinion of current and expected trends regarding the use of mushrooms and mycelia in food and feed. Mushrooms have provided food for millennia and production methods and species diversity have recently expanded. Beyond mushrooms, cultured fungal mycelia are now harvested as a primary product for food. Mushrooms and mycelia provide dietary protein, lipids and fatty acids, vitamins, fibre, and flavour, and can improve the organoleptic properties of processed foods (including meat analogues). Further, they are often key ingredients in nutritional or therapeutic supplements because of diverse specialised metabolites. Mycelia can also improve feed conversion efficiency, gut health, and wellbeing in livestock. New molecular tools, coupled with quality genetic data, are improving production technologies, enabling the synthesis of specialised metabolites, and creating new processing and valorisation opportunities. Production systems for submerged culture are capital intensive, but investment is required considering the scale of the protein market.


Assuntos
Agaricales , Alimento Funcional , Ração Animal , Aromatizantes , Paladar
5.
mSphere ; 6(3)2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980680

RESUMO

The increasing development of microbial resistance to classical antimicrobial agents has led to the search for novel antimicrobials. Antimicrobial peptides (AMPs) derived from scorpion and snake venoms offer an attractive source for the development of novel therapeutics. Smp24 (24 amino acids [aa]) and Smp43 (43 aa) are broad-spectrum AMPs that have been identified from the venom gland of the Egyptian scorpion Scorpio mauruspalmatus and subsequently characterized. Using a DNA microarray approach, we examined the transcriptomic responses of Escherichia coli to subinhibitory concentrations of Smp24 and Smp43 peptides following 5 h of incubation. Seventy-two genes were downregulated by Smp24, and 79 genes were downregulated by Smp43. Of these genes, 14 genes were downregulated in common and were associated with bacterial respiration. Fifty-two genes were specifically upregulated by Smp24. These genes were predominantly related to cation transport, particularly iron transport. Three diverse genes were independently upregulated by Smp43. Strains with knockouts of differentially regulated genes were screened to assess the effect on susceptibility to Smp peptides. Ten mutants in the knockout library had increased levels of resistance to Smp24. These genes were predominantly associated with cation transport and binding. Two mutants increased resistance to Smp43. There was no cross-resistance in mutants resistant to Smp24 or Smp43. Five mutants showed increased susceptibility to Smp24, and seven mutants showed increased susceptibility to Smp43. Of these mutants, formate dehydrogenase knockout (fdnG) resulted in increased susceptibility to both peptides. While the electrostatic association between pore-forming AMPs and bacterial membranes followed by integration of the peptide into the membrane is the initial starting point, it is clear that there are numerous subsequent additional intracellular mechanisms that contribute to their overall antimicrobial effect.IMPORTANCE The development of life-threatening resistance of pathogenic bacteria to the antibiotics typically in use in hospitals and the community today has led to an urgent need to discover novel antimicrobial agents with different mechanisms of action. As an ancient host defense mechanism of the innate immune system, antimicrobial peptides (AMPs) are attractive candidates to fill that role. Scorpion venoms have proven to be a rich source of AMPs. Smp24 and Smp43 are new AMPs that have been identified from the venom gland of the Egyptian scorpion Scorpio maurus palmatus, and these peptides can kill a wide range of bacterial pathogens. By better understanding how these AMPs affect bacterial cells, we can modify their structure to make better drugs in the future.


Assuntos
Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Estresse Oxidativo/efeitos dos fármacos , Venenos de Escorpião/farmacologia , Escorpiões/química , Sideróforos/biossíntese , Animais , Peptídeos Catiônicos Antimicrobianos/farmacologia , Egito , Perfilação da Expressão Gênica
6.
Front Pharmacol ; 12: 788874, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35082671

RESUMO

Within the last decade, several peptides have been identified according to their ability to inhibit the growth of microbial pathogens. These antimicrobial peptides (AMPs) are a part of the innate immune system of all living organisms. Many studies on their effects on prokaryotic microorganisms have been reported; some of these peptides have cytotoxic properties although the molecular mechanisms underlying their activity on eukaryotic cells remain poorly understood. Smp24 and Smp43 are novel cationic AMPs which were identified from the venom of the Egyptian scorpion Scorpio maurus palmatus. Smp24 and Smp43 showed potent activity against both Gram-positive and Gram-negative bacteria as well as fungi. Here we describe cytotoxicity of these peptides towards two acute leukaemia cell lines (myeloid (KG1-a) and lymphoid (CCRF-CEM) leukaemia cell lines) and three non-tumour cell lines CD34+ (hematopoietic stem progenitor from cord blood), HRECs (human renal epithelial cells) and HaCaT (human skin keratinocytes). Smp24 and Smp43 (4-256 µg/ml) decreased the viability of all cell lines, although HaCaT cells were markedly less sensitive. With the exception HaCaT cells, the caspase-1 gene was uniquely up-regulated in all cell lines studied. However, all cell lines showed an increase in downstream interleukin-1ß (IL-1ß) expression. Transmission electron microscope studies revealed the formation of cell membrane blebs and the appearance of autolysosomes and lipid droplets in all cell lines; KG1-a leukemia cells also showed the unique appearance of glycogen deposits. Our results reveal a novel mechanism of action for scorpion venom AMPs, activating a cascade of events leading to cell death through a programmed pyroptotic mechanism.

7.
Trends Biochem Sci ; 44(4): 365-379, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30651181

RESUMO

Toxins are substances produced from biological sources (e.g., animal, plants, microorganisms) that have deleterious effects on a living organism. Despite the obvious health concerns of being exposed to toxins, they are having substantial positive impacts in a number of industrial sectors. Several toxin-derived products are approved for clinical, veterinary, or agrochemical uses. This review sets out the case for toxins as 'friends' that are providing the basis of novel medicines, insecticides, and even nucleic acid sequencing technologies. We also discuss emerging toxins ('foes') that are becoming increasingly prevalent in a range of contexts through climate change and the globalisation of food supply chains and that ultimately pose a risk to health.


Assuntos
Toxinas Biológicas/efeitos adversos , Toxinas Biológicas/uso terapêutico , Animais , Humanos , Toxinas Biológicas/química
8.
Environ Sci Pollut Res Int ; 25(29): 29325-29334, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30121766

RESUMO

Fruit shell residue from Xanthoceras sorbifolia was investigated as a potential biosorbent to remove crude oil from aqueous solution. The shell powder and its carbonized material were compared while assessing various factors that influenced oil removal capacity. The structure and sorption mechanism were characterized using scanning electron microscopy and Fourier-transform infrared spectroscopy. The oil removal capacity of the raw material (75.1 mg g-1) was better than the carbonized material (49.5 mg g-1). The oil removal capacity increased with greater saponin content, indicating that hydrophobic and lipophilic surface characteristics of the saponins improved adsorption by the raw X. sorbifolia shell. An orthogonal experimental design was used to optimize the adsorption. Using 4 g L-1 of raw X. sorbifolia shell (particle size of < 0.15 mm), the highest crude oil removal efficiency was obtained using an initial oil concentration of 400 mg L-1, adsorption temperature of 30 °C, adsorption time of 10 min at a shaking speed of 150 rpm. The adsorption of crude oil onto X. sorbifolia shell was best described using a pseudo-second-order kinetic model. Raw X. sorbifolia shell material was more efficient than the carbonized material at crude oil removal from aqueous solution. This was attributable to the functional groups of saponins in raw X. sorbifolia shell. This study highlights that some agricultural and forest residues could be a promising source of low-cost biosorbents for oil contaminants from water-without requiring additional processing such as carbonization.


Assuntos
Petróleo , Sapindaceae/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Carbono/química , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Modelos Químicos , Tamanho da Partícula , Soluções/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Água/química , Poluentes Químicos da Água/química , Purificação da Água/instrumentação , Purificação da Água/métodos
9.
Soft Matter ; 14(29): 6146-6154, 2018 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-29999090

RESUMO

Understanding the mechanism of action of antimicrobial peptides (AMP) is fundamental to the development and design of peptide based antimicrobials. Utilizing fast-scan atomic force microscopy (AFM) we detail the attack of an AMP on both prototypical prokaryotic (DOPC:DOPG) and eukaryotic (DOPC:DOPE) model lipid membranes on the nanoscale and in real time. Previously shown to have a favourable therapeutic index, we study Smp43, an AMP with a helical-hinge-helical topology isolated from the venom of the North African scorpion Scorpio maurus palmatus. We observe the dynamic formation of highly branched defects being supported by 2D diffusion models and further experimental data from liposome leakage assays and quartz crystal microbalance-dissipation (QCM-D) analysis, we propose that Smp43 disrupts these membranes via a common mechanism, which we have termed 'diffusion limited disruption' that encompasses elements of both the carpet model and the expanding pore mechanism.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Membrana Celular/metabolismo , Animais , Difusão , Microscopia de Força Atômica , Fosfolipídeos/metabolismo , Escorpiões
10.
Front Microbiol ; 9: 1159, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29896190

RESUMO

The alarming rise in the prevalence of antibiotic resistance among pathogenic bacteria poses a unique challenge for the development of effective therapeutic agents. Antimicrobial peptides (AMPs) have attracted a great deal of attention as a possible solution to the increasing problem of antibiotic-resistant bacteria. Marcin-18 was identified from the scorpion Mesobuthus martensii at both DNA and protein levels. The genomic sequence revealed that the marcin-18 coding gene contains a phase-I intron with a GT-AG splice junction located in the DNA region encoding the N-terminal part of signal peptide. The peptide marcin-18 was also isolated from scorpion venom. A protein sequence homology search revealed that marcin-18 shares extremely high sequence identity to the AMPs meucin-18 and megicin-18. In vitro, chemically synthetic marcin-18 and its homologs (meucin-18 and megicin-18) showed highly potent inhibitory activity against Gram-positive bacteria, including some clinical antibiotic-resistant strains. Importantly, in a mouse acute peritonitis model, these peptides significantly decreased the bacterial load in ascites and rescued nearly all mice heavily infected with clinical methicillin-resistant Staphylococcus aureus from lethal bacteremia. Peptides exerted antimicrobial activity via a bactericidal mechanism and killed bacteria through membrane disruption. Taken together, marcin-18 and its homologs have potential for development as therapeutic agents for treating antibiotic-resistant, Gram-positive bacterial infections.

11.
Drug Discov Today ; 23(10): 1705-1717, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29775668

RESUMO

Inhaled administration is underutilised because the drug discovery process is viewed as challenging, risky, and expensive. However, unmet medical need continues to grow, and significant opportunities exist to discover novel inhaled medicines delivering the required lung concentrations while minimising systemic exposure. This profile could be achieved by a combination of properties, including lung retention and low oral bioavailability. Property-based rules exist for orally administered compounds, but there has been limited progress defining in silico predictors to guide the discovery of novel inhaled drugs. Recently, the use of informative cell- and tissue-based screens has greatly facilitated the identification of compounds with optimal characteristics for inhaled delivery. Here, we address opportunities for novel inhaled drugs, and the key challenges and uncertainties hampering progress.


Assuntos
Sistemas de Liberação de Medicamentos , Descoberta de Drogas/métodos , Pulmão/metabolismo , Administração por Inalação , Animais , Disponibilidade Biológica , Humanos , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/metabolismo , Distribuição Tecidual
12.
Sci Total Environ ; 615: 1-8, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28968577

RESUMO

During silicate weathering, atmospheric carbon dioxide (CO2) is consumed and base cations are released from silicate minerals to form carbonate and bicarbonate ions, which are finally deposited as carbonate complexes. Continental silicate weathering constitutes a stable carbon sink that is an important influence on long-term climate change, as it sequesters atmospheric carbon dioxide at a million-year time scale. Traditionally, CO2 sequestered through silicate weathering is estimated by measuring the flux of the base cations to watersheds. However, plants also absorb considerable amounts of base cations. Plant biomass is often removed from ecosystems during harvesting. The base cations are subsequently released after decomposition of the harvested plant materials, and thereby enhance CO2 consumption related to weathering. Here, we analyze plant biomass storage-harvest fluxes (production and removal of biomass from forests) of base cations in forests across China to quantify the relative contribution of forest trees to the terrestrial weathering-related carbon sink. Our data suggest that the potential CO2 consumption rate for biomass-related silicate weathering (from the combined action of with afforestation/reforestation, controlled harvesting and rock powder amendment) in Chinese forests is 7.9±4.1Tg CO2yr-1. This represents ~34% of the chemical weathering rate in China. Globally, forests may increase CO2 sequestration through biologically-mediated silicate weathering by ~32%.

13.
Bioresour Technol ; 244(Pt 1): 982-988, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28847093

RESUMO

In this study, the effects of four types of organic compounds (tryptone, acetate/propionate, glucose and ethanol) on methanogenesis, electron transfer processes and microbial community structure were examined. When tryptone and acetate/propionate were used, the dominant methanogenic pathway was aceticlastic methanogenesis and Methanosarcina was the most abundant methanogen. When glucose or ethanol were provided as the external carbon source, the aceticlastic and hydrogenotrophic pathways were utilised simultaneously, and Methanosarcina and Methanobacterium were enriched. However, the reactor fed with glucose was prone to acidification because volatile fatty acids accumulated in the medium, which inhibited methane synthesis. Geobacter was dominant in the reactor fed with ethanol and 45% of genes encoding pili synthesis were attributable to Geobacter, indicating that direct interspecies electron transfer may be a possible mechanism during syntrophic methanogenesis.


Assuntos
Carbono , Metano , Methanosarcina , Reatores Biológicos , Geobacter , Metagenômica , Compostos Orgânicos
14.
Bioorg Med Chem Lett ; 27(10): 2201-2206, 2017 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-28372911

RESUMO

The development of novel non-nucleoside inhibitors of the RSV polymerase complex is of significant clinical interest. Compounds derived from the benzothienoazepine core, such as AZ-27, are potent inhibitors of RSV viruses of the A-subgroup, but are only moderately active against the B serotype and as yet have not demonstrated activity in vivo. Herein we report the discovery of several novel families of C-2 arylated benzothienoazepine derivatives that are highly potent RSV polymerase inhibitors and reveal an exemplary structure, compound 4a, which shows low nanomolar activity against both RSV A and B viral subtypes. Furthermore, this compound is effective at suppressing viral replication, when administered intranasally, in a rodent model of RSV infection. These results suggest that compounds belonging to this chemotypes have the potential to provide superior anti-RSV agents than those currently available for clinical use.


Assuntos
Antivirais/química , Azepinas/química , Animais , Antivirais/síntese química , Antivirais/farmacologia , Antivirais/uso terapêutico , Azepinas/síntese química , Azepinas/farmacologia , Azepinas/uso terapêutico , RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , RNA Polimerases Dirigidas por DNA/metabolismo , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Humanos , Camundongos , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Vírus Sinciciais Respiratórios/enzimologia , Sorogrupo , Relação Estrutura-Atividade
15.
Microorganisms ; 4(1)2016 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-27681905

RESUMO

Polyhydroxyalkanoate (PHA) biopolymers are widely recognised as outstanding candidates to replace conventional petroleum-derived polymers. Their mechanical properties are good and can be tailored through copolymer composition, they are biodegradable, and unlike many alternatives, they do not rely on oil-based feedstocks. Further, they are the only commodity polymer that can be synthesised intracellularly, ensuring stereoregularity and high molecular weight. However, despite offering enormous potential for many years, they are still not making a significant impact. This is broadly because commercial uptake has been limited by variable performance (inconsistent polymer properties) and high production costs of the raw polymer. Additionally, the main type of PHA produced naturally is poly-3-hydroxybutyrate (PHB), which has limited scope due to its brittle nature and low thermal stability, as well as its tendency to embrittle over time. Production cost is strongly impacted by the type of the feedstock used. In this article we consider: the production of PHAs from methanotrophs using methane as a cost-effective substrate; the use of mixed cultures, as opposed to pure strains; and strategies to generate a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer (PHBV), which has more desirable qualities such as toughness and elasticity.

16.
Biochim Biophys Acta ; 1858(11): 2737-2744, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27480803

RESUMO

Determining the mechanism of action of antimicrobial peptides (AMPs) is critical if they are to be developed into the clinical setting. In recent years high resolution techniques such as atomic force microscopy (AFM) have increasingly been utilised to determine AMP mechanism of action on planar lipid bilayers and live bacteria. Here we present the biophysical characterisation of a prototypical AMP from the venom of the North African scorpion Scorpio maurus palmatus termed Smp24. Smp24 is an amphipathic helical peptide containing 24 residues with a charge of +3 and exhibits both antimicrobial and cytotoxic activity and we aim to elucidate the mechanism of action of this peptide on both membrane systems. Using AFM, quartz crystal microbalance-dissipation (QCM-D) and liposomal leakage assays the effect of Smp24 on prototypical synthetic prokaryotic (DOPG:DOPC) and eukaryotic (DOPE:DOPC) membranes has been determined. Our data points to a toroidal pore mechanism against the prokaryotic like membrane whilst the formation of hexagonal phase non-lamellar phase structures is seen in eukaryotic like membrane. Also, phase segregation is observed against the eukaryotic membrane and this study provides direct evidence of the same peptide having multiple mechanisms of action depending on the membrane lipid composition.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Bicamadas Lipídicas/química , Lipossomos/química , Venenos de Escorpião/farmacologia , Animais , Peptídeos Catiônicos Antimicrobianos/síntese química , Mimetismo Molecular , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Fosfatidilgliceróis/química , Conformação Proteica em alfa-Hélice , Venenos de Escorpião/síntese química , Escorpiões/química , Eletricidade Estática
17.
Toxicon ; 117: 30-6, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27019370

RESUMO

Scorpion venoms provide a rich source of anti-microbial peptides. Here we characterise three from the venom of Scorpion maurus palmatus. Smp13 is biologically inactive, despite sharing homology with other antimicrobial peptides, probably because it lacks a typically charged structure. Both Smp-24 and Smp-43 have broad spectrum antimicrobial activity, disrupting bacterial membranes. In addition, there is evidence that Smp24 may inhibit DNA synthesis in Bacillus subtilis. Smp24 haemolysed red blood cells but in contrast, Smp43 was non-haemolytic. The introduction of a flexible Gly-Val-Gly hinge into the middle of Smp24 did not alter the haemolytic activity of Smp24 (as might have been predicted from earlier studies with Pandinin2 (Pin2), although C-terminal truncation of Smp-24 reduced its haemolytic activity, in agreement with earlier Pin 2 studies. Smp24 and its derivatives, as well as Smp-43, were all cytotoxic (ATP release assay) toward mammalian HepG2 liver cells. Our results highlight the beneficial effect of helical-hinge-helical conformation on promoting prokaryotic selectivity of long chain scorpion AMPs, as well as the importance of examining a wide range of mammalian cell types in cytotoxicity testing.


Assuntos
Anti-Infecciosos/química , Citotoxinas/química , Inibidores da Síntese de Ácido Nucleico/química , Venenos de Escorpião/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Citotoxinas/isolamento & purificação , Citotoxinas/farmacologia , Hemólise/efeitos dos fármacos , Células Hep G2 , Humanos , Inibidores da Síntese de Ácido Nucleico/isolamento & purificação , Inibidores da Síntese de Ácido Nucleico/farmacologia , Conformação Proteica em alfa-Hélice/fisiologia
18.
J Med Chem ; 59(5): 1727-46, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26800309

RESUMO

The discovery of a novel series of therapeutic agents that has been designed and optimized for treating chronic obstructive pulmonary disease is reported. The pharmacological strategy was based on the identification of compounds that inhibit a defined subset of kinase enzymes modulating inflammatory processes that would be effective against steroid refractory disease and exhibit a sustained duration of action after inhaled delivery.


Assuntos
Asma/tratamento farmacológico , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/metabolismo , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Animais , Asma/metabolismo , Relação Dose-Resposta a Droga , Resistência a Medicamentos/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Doença Pulmonar Obstrutiva Crônica/metabolismo , Esteroides/farmacologia , Relação Estrutura-Atividade , Células U937
19.
Toxicon ; 88: 115-37, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24951876

RESUMO

The need for new antimicrobial agents is becoming one of the most urgent requirements in modern medicine. The venoms of many different species are rich sources of biologically active components and various therapeutic agents have been characterized including antimicrobial peptides (AMPs). Due to their potent activity, low resistance rates and unique mode of action, AMPs have recently received much attention. This review focuses on AMPs from the venoms of scorpions and examines all classes of AMPs found to date. It gives details of their biological activities with reference to peptide structure. The review examines the mechanism of action of AMPs and with this information, suggests possible mechanisms of action of less well characterised peptides. Finally, the review examines current and future trends of scorpion AMP research, by discussing recent successes obtained through proteomic and transcriptomic approaches.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Venenos de Escorpião/análise , Sequência de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/química , Defensinas/farmacologia , Dados de Sequência Molecular
20.
J Venom Anim Toxins Incl Trop Dis ; 19(1): 10, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23849458

RESUMO

BACKGROUND: It is estimated that venoms of marine cone snails (genus Conus) contain more than 100,000 different small peptides with a wide range of pharmacological and biological actions. Some of these peptides were developed into potential therapeutic agents and as molecular tools to understand biological functions of nervous and cardiovascular systems. In this study we examined the cytotoxic and anticancer properties of the marine vermivorous cone snail Conus vexillum (collected from Hurgada and Sharm El-Shaikh, Red Sea, Egypt) and suggest the possible mechanisms involved. The in vitro cytotoxic effects of Conus venom were assessed against Ehrlich's ascites carcinoma (EAC) cells. RESULTS: Conus venom treatment resulted in concentration-dependent cytotoxicity as indicated by a lactate dehydrogenase leakage assay. Apoptotic effects were measured in vivo by measuring levels of reactive oxygen species and oxidative defense agents in albino mice injected with EAC cells. Conus venom (1.25 mg/kg) induced a significant increase (p < 0.05) in several oxidative stress biomarkers (lipid peroxidation, protein carbonyl content and reactive nitrogen intermediates) of EAC cells after 3, 6, 9 and 12 hours of venom injection. Conus venom significantly reduced (p < 0.05) the activities of oxidative defense enzymes (catalase and superoxide dismutase) as well as the total antioxidant capacity of EAC cells, as evidenced by lowered levels of reduced glutathione. CONCLUSIONS: These results demonstrate the cytotoxic potential of C. vexillum venom by inducing oxidative stress mediated mechanisms in tumor cells and suggest that the venom contains novel molecules with potential anticancer activity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...