Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40.296
Filtrar
1.
Methods Mol Biol ; 2576: 111-118, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36152180

RESUMO

Displacement binding assays are nonfunctional assays mostly used with the aim of determining whether a certain compound (plant-derived or synthetic) can bind to a specific receptor with high affinity. Here, we describe the displacement binding assay that is carried out with a radioligand and CHO (Chinese Hamster Ovarian) cells stably transfected with the human cannabinoid CB2 receptor.


Assuntos
Bioensaio , Canabinoides , Animais , Células CHO , Canabinoides/metabolismo , Cricetinae , Cricetulus , Humanos , Ensaio Radioligante , Receptor CB2 de Canabinoide/genética , Receptores de Canabinoides
2.
Methods Mol Biol ; 2576: 225-232, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36152190

RESUMO

N-Acyl-phosphatidylethanolamine (NAPE)-hydrolyzing phospholipase D (NAPE-PLD) is a prominent enzyme involved in the biosynthesis of fatty acid amides, a family of bioactive lipids including anandamide as the prototypical member. Here, we describe a NAPE-PLD assay based on radioactive substrates and product separation by thin layer chromatography (TLC).


Assuntos
Fosfatidiletanolaminas , Fosfolipase D , Bioensaio , Cromatografia em Camada Delgada , Fosfatidiletanolaminas/química , Piridoxal/análogos & derivados
3.
Braz. j. biol ; 83: e03316, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345530

RESUMO

Abstract Behavioral lab bioassays involving termites must be promptly performed to allow intended observations prior to death from dissecation, typical of these soft-bodied insects. To this end, topic markers have been proposed as an alternative to histological stains which, while not always toxic are inevitably lengthy to apply. Among recommended topic markers, gouache is easy to apply, dries out quickly, but it is known affect termites in the long run, being suitable only to short-term bioassays. Its alternative, colored glue, is also easy to apply, but it takes long to dry and it is too dense and heavy, being thus prone to affect termite walking patterns. Here we tested a mix of gouache and colored glue aiming to combine the qualities of both into a suitable topical marker for Cornitermes cumulans termites. Similar patterns of survival presented by marked and unmarked termites ruled out concerns about toxicity of this mixture. Such results were consistent across distinct group densities evidencing that the mixture does not interfere with, nor it is affected by, crowding effects. Because crowding regulates interindividual interactions and these underlie most behaviors, the mixture can be thought to be suitable to behavioral studies. We argue that this 1:2 glue:gouache mixture is an excellent alternative to mark termites for lab bioassays. Being atoxic, cheap, easy to apply, and non-invasive, this mixture may happen to be useful not only for termites but also in bioassaying other similarly soft-bodied insects.


Resumo Bioensaios comportamentais em laboratório com cupins devem ser realizados rapidamente a fim de garantir observações antes da morte por dissecação, típico desses insetos de corpo mole. Para este fim, marcadores tópicos têm sido propostos como uma alternativa para marcadores histológicos que, embora nem sempre tóxico, possuem uma aplicação demorada. Entre os marcadores tópicos recomendados, tinta guache é de fácil aplicação, rápida secagem, porém afeta os cupins em bioensaios longos, sendo adequado apenas para bioensaios curtos. Sua alternativa, cola colorida, também é de fácil aplicação mas leva muito tempo para secar e é muito denso e pesado, afetando os padrões de caminhamento dos cupins. No presente estudo, nós testamos uma mistura de tinta guache e cola colorida objetivando combinar as qualidades de ambos os marcadores tópicos em um marcador tópico adequado para Cornitermes cumulans. Padrões similares de sobrevivência entre cupins marcados e controle indicam a ausência de toxicidade na mistura de tinta guache e cola colorida. Tais resultados são consistentes em grupos de densidades distintas, o que comprova que a mistura não interfere, nem sofre efeitos de aglomeração. Uma vez que a aglomeração regula as interações inter-individuais e afetam a maioria dos comportamentos, a mistura pode ser adequada para estudos comportamentais. Nós argumentamos que a mistura de tinta guache e cola (1:2) é uma excelente alternativa como marcador tópico em cupins para bioensaios em laboratório. Sendo atóxico, barato, fácil de aplicar e não invasivo, esta mistura pode ser útil não só para os cupins, mas também em bioensaios com outros insetos de corpo mole.


Assuntos
Animais , Baratas , Isópteros , Bioensaio , Laboratórios
4.
Nutrients ; 14(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36079877

RESUMO

Soy isoflavones, at adequate dosages, have estrogenic and anti-thyroidal effects in animals and humans, which can either be beneficial or adverse, depending on the consumer's physiological status. Hence, this study presents an assay of soy isoflavones in hair, aiming to give new information about a person's exposure to isoflavones, when health issues related to estrogenic or thyroidal effects are observed. Aqueous or organic extraction procedures following acidic, basic, or enzymatic digestions were tested on 60 hair samples (from volunteers) from a hairdresser, and a clinical trial 2017T2-29. The acidic digestion method was the most efficient regarding isoflavones. A specific inquiry was developed to assess the dietary habits of French consumers based on the analysis of 12,707 food labels from France. It was used to check for the reliability of the new assay method. A score for the consumer exposures to isoflavones was built considering, among other parameters, soy-based diets and foodstuff containing soy as an ingredient, i.e., "hidden-soy". The correlation between this score and isoflavone measurements in hair reached 0.947; p < 0.001. Therefore, providing that relevant data are considered to assess isoflavone exposure, hair that smoothens daily isoflavone intake variations, is a relevant tissue to assess human isoflavone exposure for subsequent health analyses.


Assuntos
Bioensaio , Cabelo , Isoflavonas , Soja , Dieta , Feminino , Cabelo/química , Humanos , Isoflavonas/análise , Reprodutibilidade dos Testes
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 1659-1662, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36085889

RESUMO

The Cellular Thermal Shift Assay (CETSA) is a biophysical assay based on the principle of ligand-induced thermal stabilization of target proteins. This technology has revolutionized cell-based target engagement studies and has been used as guidance for drug design. Although many ap-plications of CETSA data have been explored, the correlations between CETSA data and protein-protein interactions (PPI) have barely been touched. In this study, we conduct the first exploration study applying CETSA data for PPI prediction. We use a machine learning method, Decision Tree, to predict PPI scores using proteins' CETSA features. It shows promising results that the predicted PPI scores closely match the ground-truth PPI scores. Furthermore, for a small number of protein pairs, whose PPI score predictions mismatch the ground truth, we use iterative clustering strategy to gradually reduce the number of these pairs. At the end of iterative clustering, the remaining protein pairs may have some unusual properties and are of scientific value for further biological investigation. Our study has demonstrated that PPI is a brand-new application of CETSA data. At the same time, it also manifests that CETSA data can be used as a new data source for PPI exploration study.


Assuntos
Bioensaio , Projetos de Pesquisa , Biofísica , Análise por Conglomerados , Domínios Proteicos
6.
Anal Chim Acta ; 1227: 340307, 2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36089318

RESUMO

The detection of DNA methylation with high sensitivity and specificity is important for the early diagnosis of many human diseases, including cancers. Here, we integrated the high specificity of the methylation-dependent restriction endonuclease GlaI for methylation-dependent digestion and the high amplification efficiency of rolling circle amplification (RCA) for the detection of GlaI digestion products. GlaI can only digest a methylated template, leading to the generation of digestion products with specific ends. The specific digestion product can then be ligated to a ligation mediator with a dumbbell structure to generate a complete circular template for further RCA, and the final RCA amplicon can be detected using lateral flow detection (LFD) with the naked eye. The specificity of Gla-RCA not only depends on the specific methylation digestion of GlaI, but only the ligation process of RCA amplification. As a proof of principle, the sensitivity of GlaI-RCA assay was applied to methylated Septin 9 and showed a sensitivity of approximately 1% (50 copies of methylated template per reaction) and no cross-reactivity with 5000 copies of unmethylated DNA used as background. The application of GlaI-RCA was also evaluated with colorectal cancer tissue samples and showed great accordance with standard bisulfite sequencing. A bisulfite-free and LFD-based DNA methylation detection was successfully developed, promising high specificity and rapid visual detection and having a great potential to become a robust tool for DNA methylations analysis.


Assuntos
Metilação de DNA , Técnicas de Amplificação de Ácido Nucleico , Bioensaio , DNA/química , DNA/genética , Enzimas de Restrição do DNA/genética , Humanos
7.
Molecules ; 27(17)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-36080125

RESUMO

Despite the rapid advances in drug R&D, there is still a huge need for antibacterial medications, specifically for the methicillin-resistant Staphylococcus aureus (MRSA). Inspired by the research where a viable class of MRSA inhibitors was found in the species Platanus occidentalis, a S. aureus inhibition screening-guided phytochemical reinvestigation on Platanus × acerifolia (London plane tree) leaves were performed with four flavonoid glycosides garnered, including two new compounds, quercetin-3-O-α-l-(2″-E-p-coumaroyl-3″-Z-p-coumaroyl)-rhamnopyranoside (E,Z-3'-hydroxyplatanoside, 1) and quercetin-3-O-α-l-(2″-Z-p-coumaroyl-3″-E-p-coumaroyl)-rhamnopyranoside (Z,E-3'-hydroxyplatanoside, 2). All of the isolates showed significant S. aureus ATCC 25904 inhibitory activity with MICs ranging from 4 to 64 µg/mL, suggesting the potential of discovering drug leads for the control of S. aureus from such a rich, urban landscaping plant in the Platanus genus.


Assuntos
Glicosídeos , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/química , Bioensaio , Flavonoides/química , Glicosídeos/química , Testes de Sensibilidade Microbiana , Folhas de Planta/química , Quercetina/farmacologia , Staphylococcus aureus
8.
Molecules ; 27(17)2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36080262

RESUMO

Erythrostemon yucatanensis (Greenm.) Gagnon & GP Lewis is a legume tree native to and widely distributed in southeast Mexico, where its branches are used in traditional medicine. An in vitro evaluation of the antiviral activity of extracts and fractions from the leaves, stem bark and roots against two strains of the AH1N1 influenza virus was performed, leading to the identification of bioactive compounds in this medicinal plant. In a cytopathic effect reduction assay, the fractions from the leaves and stem bark were the active elements at the co-treatment level. These were further fractionated based on their hemagglutination inhibition activity. The analysis of spectroscopy data identified a combination of phytosterols (ß-sitosterol, stigmasterol and campesterol) in the stem bark active fraction as the main anti-hemagglutinin binding components, while 5-hydroxy-2(2-hydroxy-3,4,5-trimethoxyphenyl)-7-metoxi-4H(chromen-4-ona), which was isolated from the leaf extracts, showed a weak inhibition of viral hemagglutinin. Time of addition experiments demonstrated that the mixture of sterols had a direct effect on viral particle infectivity at the co-treatment level (IC50 = 3.125 µg/mL). This effect was also observed in the virus plaque formation inhibition assay, where the mixture showed 90% inhibition in the first 20 min of co-treatment at the same concentration. Additionally, it was found using qRT-PCR that the NP copy number was reduced by 92.85% after 60 min of co-treatment. These results are the first report of components with anti-hemagglutinin binding activity in the genus Erythrostemon sp.


Assuntos
Fabaceae , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A , Influenza Humana , Antivirais/química , Bioensaio , Hemaglutininas , Humanos , Extratos Vegetais/química
9.
J Oleo Sci ; 71(9): 1403-1412, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36047244

RESUMO

Clove, a dried flower buds of Syzygium aromaticum, is used in traditional medicine, for culinary purposes, and in essential oil production. In our preliminary screening of crude drugs used in Japanese Kampo formulas, a methanol (MeOH) extract of clove buds was found to exhibit a melanin induction. To date, the effects of clove buds or their constituents on the activation of melanogenesis remain unclear. Thus, this study aimed to isolate active compounds from the MeOH extract of clove buds associated with melanin synthesis in melanoma cells and to investigate the molecular mechanism involved. The MeOH extract of clove buds increased melanin content in murine B16-F1 melanoma cells. To identify the active compounds responsible for melanin induction, the MeOH extract was suspended in water and successively partitioned using hexane, ethyl acetate (EtOAc), and n-butanol (n-BuOH). Comparative analysis revealed that the EtOAc fraction induced melanin synthesis. Bioassay-guided separation of the EtOAc fraction isolated three compounds including eugenol. The analysis of structure-activity relationships of eugenol and structurally related compounds indicated that eugenol was the most potent melanin inducer among the 11 compounds, and that a hydroxyl group at C-1 and a methoxy group at C-2 may contribute to melanin induction. Eugenol induced melanin synthesis in human HMV-II melanoma cells as well as in B16-F1 cells. Further analysis indicated that eugenol may invoke intracellular tyrosinase activity and expression of tyrosinase, tyrosinaserelated protein (TRP)-1, TRP-2, and microphthalmia-associated transcription factor (MITF). These results suggest that eugenol enhances melanin synthesis by upregulating the expression of MITF and subsequent expression of melanogenic enzymes, and that it may be a potent therapeutic agent for hypopigmentation.


Assuntos
Melanoma Experimental , Syzygium , Animais , Bioensaio , Eugenol/farmacologia , Eugenol/uso terapêutico , Humanos , Melaninas , Melanoma Experimental/metabolismo , Metanol , Camundongos , Monofenol Mono-Oxigenase/metabolismo , Extratos Vegetais/farmacologia , Syzygium/metabolismo
10.
ACS Chem Biol ; 17(9): 2471-2482, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36049119

RESUMO

Determining a molecule's mechanism of action is paramount during chemical probe development and drug discovery. The cellular thermal shift assay (CETSA) is a valuable tool to confirm target engagement in cells for a small molecule that demonstrates a pharmacological effect. CETSA directly detects biophysical interactions between ligands and protein targets, which can alter a protein's unfolding and aggregation properties in response to thermal challenge. In traditional CETSA experiments, each temperature requires an individual sample, which restricts throughput and requires substantial optimization. To capture the full aggregation profile of a protein from a single sample, we developed a prototype real-time CETSA (RT-CETSA) platform by coupling a real-time PCR instrument with a CCD camera to detect luminescence. A thermally stable Nanoluciferase variant (ThermLuc) was bioengineered to withstand unfolding at temperatures greater than 90 °C and was compatible with monitoring target engagement events when fused to diverse targets. Utilizing well-characterized inhibitors of lactate dehydrogenase alpha, RT-CETSA showed significant correlation with enzymatic, biophysical, and other cell-based assays. A data analysis pipeline was developed to enhance the sensitivity of RT-CETSA to detect on-target binding. RT-CETSA technology advances capabilities of the CETSA method and facilitates the identification of ligand-target engagement in cells, a critical step in assessing the mechanism of action of a small molecule.


Assuntos
Bioensaio , Descoberta de Drogas , Bioensaio/métodos , Descoberta de Drogas/métodos , Lactato Desidrogenases , Ligantes
12.
Chem Rev ; 122(18): 14881-14910, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-36067039

RESUMO

Lateral flow assays (LFAs) are currently the most used point-of-care sensors for both diagnostic (e.g., pregnancy test, COVID-19 monitoring) and environmental (e.g., pesticides and bacterial monitoring) applications. Although the core of LFA technology was developed several decades ago, in recent years the integration of novel nanomaterials as signal transducers or receptor immobilization platforms has brought improved analytical capabilities. In this Review, we present how nanomaterial-based LFAs can address the inherent challenges of point-of-care (PoC) diagnostics such as sensitivity enhancement, lowering of detection limits, multiplexing, and quantification of analytes in complex samples. Specifically, we highlight the strategies that can synergistically solve the limitations of current LFAs and that have proven commercial feasibility. Finally, we discuss the barriers toward commercialization and the next generation of LFAs.


Assuntos
COVID-19 , Nanopartículas Metálicas , Nanoestruturas , Praguicidas , Bioensaio , COVID-19/diagnóstico , Humanos , Sistemas Automatizados de Assistência Junto ao Leito
13.
ACS Nano ; 16(9): 15484-15494, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36094397

RESUMO

The preclinical assessment of efficacy and safety is essential for cardiovascular drug development in order to guarantee effective prevention and treatment of cardiovascular disease and avoid human health endangerment and a huge waste of resources. Rhythmic mechanical beating as one of the crucial cardiomyocyte properties has been exploited to establish a drug assessment biosensing platform. However, the conventional label-free biosensing platforms are difficult to perform high-throughput and high-resolution mechanical beating detection for a single cardiomyocyte, while label-based strategies are limited by pharmacologically adverse effects and phototoxicity. Herein, we propose a biosensing platform involving the multichannel electrode array device and the universal mechanical beating detection system. The platform can determine the optimal characteristic working frequency of different devices and dynamically interrogate the viability of multisite single cardiomyocytes to establish the optimized cell-based model for sensitive drug assessment. The subtle changes of mechanical beating signals induced by cardiovascular drugs can be detected by the platform, thereby demonstrating its high performance in pharmacological assessment. The universal and sensitive drug assessment biosensing platform is believed to be widely applied in cardiology investigating and preclinical drug screening.


Assuntos
Técnicas Biossensoriais , Fármacos Cardiovasculares , Bioensaio , Fármacos Cardiovasculares/farmacologia , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Humanos , Miócitos Cardíacos
14.
Anal Chem ; 94(37): 12715-12722, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36076186

RESUMO

Inspired by the interpretation of two-dimensional (2D) nuclear magnetic resonance spectra, an efficient strategy was proposed for pinpointing bioactive components from complex natural products. An off-line comprehensive countercurrent chromatography (CCC) × high-performance liquid chromatography (HPLC) was employed to achieve a 2D chemical chromatogram, and 2D bioassay profilings were obtained from bioassays of the eluent of the first dimension (1D) CCC and the eluent of the second dimension (2D) HPLC. Then 2D chemical chromatograms and 2D bioassay profilings were matched for pinpointing bioactive natural components from complex matrices. Thus, bioactive components in a complex matrix could be efficiently analyzed, separated, and bioactivity-determined. This experimental scheme was successfully demonstrated with a traditional medicinal herb Polygonum cuspidatum Sieb. et Zucc. The feasibility of this 2D strategy was verified with tyrosinase inhibition assay, α-glucosidase inhibition assay, DPPH radical scavenging assay, and ABTS•+ decolorization assay. Eight natural inhibitors were successfully pinpointed and identified from P. cuspidatum. Both pieceid-2″-O-gallate (10) and vanicoside B (20) were screened and identified as natural tyrosinase inhibitors for the first time. Meanwhile, vanicoside B (20) was also found as the strongest α-glucosidase inhibitor among all the isolated components. Most of the compounds exhibited much higher radical scavenging activities. Compared with traditional methodology based on one-dimensional chromatographic separation, the present 2D strategy would be more precise, efficient, and convenient to screen and separate bioactive compounds from complex matrices.


Assuntos
Distribuição Contracorrente , Monofenol Mono-Oxigenase , Bioensaio , Cromatografia Líquida de Alta Pressão/métodos , Cinamatos , Distribuição Contracorrente/métodos , Inibidores de Glicosídeo Hidrolases , Extratos Vegetais/química , Extratos Vegetais/farmacologia , alfa-Glucosidases
15.
J Mol Graph Model ; 117: 108325, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36088765

RESUMO

CRBN protein is an E3 ubiquitin ligase which plays an important role in the ubiquitin-proteasome system of eukaryotic cells. Small molecules can modulate CRBN and induce multiple target proteins to bind with CRBN, which contributes to ubiquitination and degradation of target proteins. Modulating the CRBN protein through small molecules provides a novel idea for treatment of tumors and immune system disease. Due to most of CRBN modulators containing glutarimide skeleton, we aimed to discover novel potent CRBN modulators. In this study, Lipinski's rule and Veber rule, pharmacophore based virtual screening, docking based virtual screening and ADMET screening methods were performed to discover potential CRBN modulators. The antitumor activity of 11 candidates were evaluated by MTS assay. AN7535 showed potent antitumor activity with IC50 = 0.72 µM against HL-60 and IC50 = 1.438 µM against SMMC-7721. AO6355 showed potent antitumor activity with IC50 = 7.469 µM against SMMC-7721. MD simulations and binding free energy calculations suggested that AN7535 and AO6355 could stabilize the CRBN protein and have favorable binding affinity with CRBN protein. Luciferase complementation assay suggested AN7535 could bind to CRBN with IC50 = 215.9 µM.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Complexo de Endopeptidases do Proteassoma , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Bioensaio , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina-Proteína Ligases/química , Ubiquitinas/metabolismo
16.
AAPS J ; 24(6): 102, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36167856

RESUMO

Historically, a neutralization antibody (NAb) assay is considered critical in immunogenicity assessment of biologic therapeutics, even with low anti-drug antibody (ADA) positive rates. In 2019, FDA new guidelines issued on immunogenicity testing acknowledged the possibility of using "a highly sensitive PD marker or an appropriately designed PK assay or both that generate data that inform clinical activity" to replace a NAb assay. In the current manuscript, we present data for PK, PD, and ADA assays which collectively succeed to replace the standalone NAb assay. The data include a total LC/MS-based PK assay, a serum neutralization antibody (SNA) assay that essentially measures pharmacodynamically functional PK and can detect NAb activity in the presence of 1:1 ratio of drug, and a highly drug-tolerant ADA assay. In addition, a model-based meta-analysis (MBMA) demonstrated that the ability of SNA assay to detect NAb at 1:1 ratio of drug is sensitive enough to monitor clinically meaningful efficacy change, which is 50% reduction of SNA titer. Our strategy of preparing a holistic data package discussed here may provide a roadmap to the community for alternatives in assaying neutralizing activity of ADA.


Assuntos
Anticorpos Neutralizantes , Produtos Biológicos , Bioensaio , Cromatografia Líquida , Análise de Dados
17.
Biosensors (Basel) ; 12(9)2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-36140125

RESUMO

We report analysis of phosphatase activity and inhibition on droplet-based microfluidic chips. Phosphatases are such attractive potential drug targets because abnormal phosphatase activity has been implicated in a variety of diseases including cancer, neurological disorders, diabetes, osteoporosis, and obesity. So far, several methods for assessing phosphatase activity have been reported. However, they require a large sample volume and additional chemical modifications such as fluorescent dye conjugation and nanomaterial conjugation, and are not cost-effective. In this study, we used an artificial phosphatase substrate 3-O-methylfluorescein phosphate as a fluorescent reporter and dual specificity phosphatase 22. Using these materials, the phosphatase assay was performed from approximately 340.4 picoliter (pL) droplets generated at a frequency of ~40 hertz (Hz) in a droplet-based microfluidic chip. To evaluate the suitability of droplet-based platform for screening phosphatase inhibitors, a dose-response inhibition study was performed with ethyl-3,4-dephostatin and the half-maximal inhibitory concentration (IC50) was calculated as 5.79 ± 1.09 µM. The droplet-based results were compared to microplate-based experiments, which showed agreement. The droplet-based phosphatase assay proposed here is simple, reproducible, and generates enormous data sets within the limited sample and reagent volumes.


Assuntos
Técnicas Analíticas Microfluídicas , Microfluídica , Bioensaio/métodos , Fosfatases de Especificidade Dupla , Inibidores Enzimáticos , Corantes Fluorescentes , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/métodos
18.
Molecules ; 27(18)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36144672

RESUMO

Based on data from a previous ethnobotanical study in northern Angola, phytochemical investigations into the methanolic rhizomes and roots extract of Cyperus&nbsp;articulatus, monitored by in vitro assays, resulted in the recovery of 12 sesquiterpenes, 3 stilbenes, 2 phenolic acids, 1 monoterpene, and 1 flavonoid. Among them, 14 compounds were isolated for the first time from this species. Their inhibitory potential against nitric oxide (NO) production, as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, was evaluated in LPS-treated J774A.1 murine macrophages. Especially, both stilbene dimer trans-scirpusin B and trimer cyperusphenol B showed promising inhibitory activity against the production of the inflammatory mediator, NO, in a concentration-dependent manner (10-1 µM). The obtained data are the first results confirming the anti-inflammatory potential of C.&nbsp;articulatus and support its indigenous use as a traditional remedy against inflammation-related disorders.


Assuntos
Cyperus , Sesquiterpenos , Estilbenos , Animais , Anti-Inflamatórios/farmacologia , Bioensaio , Ciclo-Oxigenase 2/metabolismo , Cyperus/química , Flavonoides , Mediadores da Inflamação , Lipopolissacarídeos/farmacologia , Camundongos , Monoterpenos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sesquiterpenos/farmacologia , Estilbenos/farmacologia
19.
J Chem Inf Model ; 62(18): 4512-4522, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36053674

RESUMO

Five major variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged and posed challenges in controlling the pandemic. Among them, the current dominant variant, viz., Omicron, has raised serious concerns about its infectiousness and antibody neutralization. However, few studies pay attention to the effect of the mutations on the dynamic interaction network of Omicron S protein trimers binding to the host angiotensin-converting enzyme 2 (ACE2). In this study, we conducted molecular dynamics (MD) simulations and enzyme linked immunosorbent assay (ELISA) to explore the binding strength and mechanism of wild type (WT), Delta, and Omicron S protein trimers to ACE2. The results showed that the binding capacities of both the two variants' S protein trimers to ACE2 are enhanced in varying degrees, indicating possibly higher cell infectiousness. Energy decomposition and protein-protein interaction network analysis suggested that both the mutational and conserved sites make effects on the increase in the overall affinity through a variety of interactions. The experimentally determined KD values by biolayer interferometry (BLI) and the predicted binding free energies of the RBDs of Delta and Omicron to mAb HLX70 revealed that the two variants may have the high risk of immune evasion from the mAb. These results are not only helpful in understanding the binding strength and mechanism of S protein trimer-ACE2 but also beneficial for drug, especially for antibody development.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Bioensaio , Humanos , Simulação de Dinâmica Molecular , Mutação , Peptidil Dipeptidase A/química , Ligação Proteica , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/metabolismo
20.
Methods Mol Biol ; 2556: 141-148, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36175632

RESUMO

It is well known that influenza viruses utilize host cell glycans for virus attachment factors via their major glycoprotein, hemagglutinin (HA), to initiate their invasion to host cells. Unlike well-known theories in human and avian influenza viruses, barriers laying between interspecies transmission of influenza viruses among bird species are not well understood. Recently, it was speculated that glycan binding of the HA to fucosylated Siaα2-3Gal is related to the expansion in the host range of the virus in avian species. Accordingly, the binding specificity of avian influenza viruses to fucosylated Siaα2-3Gal glycans should be monitored for the better control of avian influenza in both poultry and wild birds. Here, general methods and points for the glycan-binding assay that are specifically modified to target fucosylated Siaα2-3Gal glycans are provided.


Assuntos
Vírus da Influenza A , Influenza Aviária , Animais , Bioensaio , Hemaglutininas , Humanos , Receptores Virais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...