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1.
Anal Chim Acta ; 1179: 338826, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34535248

RESUMO

Fluorescence-based methods for the identification of enzyme inhibitors are widespread, but usually require protein or ligand labelling. In this study, we present a label-free displacement assay that takes advantage of the intrinsic fluorescence of a tight binding ligand avoiding any labeling. Autodisplay-based accessibility of the target enzyme on the cell surface of Escherichia coli enabled the quantification of fluorescent ligand binding by flow cytometry. Human protein kinase CK2 was used as proof-of-concept enzyme and its ATP competitive inhibitor (E)-1,3-dichloro-6-[(4-methoxyphenylimino)methyl]dibenzo[b,d]furan-2,7-diol (compound 5) was shown to exhibit intrinsic fluorescence (λmax(ex) = 370 nm, λmax(em) = 585 nm). Binding of compound 5 to CK2 displaying cells was quantified via flow cytometry with linearly increasing relative fluorescence up to a concentration of 1.25 µM. The addition of the non-fluorescent CK2 inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) competed for compound 5 binding with a half maximal fluorescence reduction at 15.6 µM TBB. This new and simple binding assay provides a valuable tool for the screening of high affinity enzyme inhibitors, overcoming the limitations of fluorescent ligand labelling.


Assuntos
Inibidores Enzimáticos , Inibidores de Proteínas Quinases , Inibidores Enzimáticos/farmacologia , Citometria de Fluxo , Humanos , Inibidores de Proteínas Quinases/farmacologia
2.
Nat Commun ; 12(1): 4838, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376698

RESUMO

Macropinosomes are formed by shaping actin-rich plasma membrane ruffles into large intracellular organelles in a phosphatidylinositol 3-kinase (PI3K)-coordinated manner. Here, we utilize lattice lightsheet microscopy and image visualization methods to map the three-dimensional structure and dynamics of macropinosome formation relative to PI3K activity. We show that multiple ruffling morphologies produce macropinosomes and that the majority form through collisions of adjacent PI3K-rich ruffles. By combining multiple volumetric representations of the plasma membrane structure and PI3K products, we show that PI3K activity begins early throughout the entire ruffle volume and continues to increase until peak activity concentrates at the base of the ruffle after the macropinosome closes. Additionally, areas of the plasma membrane rich in ruffling had increased PI3K activity and produced many macropinosomes of various sizes. Pharmacologic inhibition of PI3K activity had little effect on the rate and morphology of membrane ruffling, demonstrating that early production of 3'-phosphoinositides within ruffles plays a minor role in regulating their morphology. However, 3'-phosphoinositides are critical for the fusogenic activity that seals ruffles into macropinosomes. Taken together, these data indicate that local PI3K activity is amplified in ruffles and serves as a priming mechanism for closure and sealing of ruffles into macropinosomes.


Assuntos
Membrana Celular/metabolismo , Microscopia de Fluorescência/métodos , Fosfatidilinositol 3-Quinases/metabolismo , Pinocitose/fisiologia , Animais , Membrana Celular/efeitos dos fármacos , Células Cultivadas , Cromonas/farmacologia , Inibidores Enzimáticos/farmacologia , Células HEK293 , Humanos , Macrófagos/citologia , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Camundongos , Microscopia Eletrônica de Varredura , Morfolinas/farmacologia , Fosfatidilinositóis/metabolismo , Pinocitose/efeitos dos fármacos , Células RAW 264.7
3.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34353890

RESUMO

Alum, used as an adjuvant in injected vaccines, promotes T helper 2 (Th2) and serum antibody (Ab) responses. However, it fails to induce secretory immunoglobulin (Ig) A (SIgA) in mucosal tissues and is poor in inducing Th1 and cell-mediated immunity. Alum stimulates interleukin 1 (IL-1) and the recruitment of myeloid cells, including neutrophils. We investigated whether neutrophil elastase regulates the adjuvanticity of alum, and whether a strategy targeting neutrophil elastase could improve responses to injected vaccines. Mice coadministered a pharmacological inhibitor of elastase, or lacking elastase, developed high-affinity serum IgG and IgA antibodies after immunization with alum-adsorbed protein vaccines, including the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2). These mice also developed broader antigen-specific CD4+ T cell responses, including high Th1 and T follicular helper (Tfh) responses. Interestingly, in the absence of elastase activity, mucosal SIgA responses were induced after systemic immunization with alum as adjuvant. Importantly, lack or suppression of elastase activity enhanced the magnitude of anti-SARS-CoV-2 spike subunit 1 (S1) antibodies, and these antibodies reacted with the same epitopes of spike 1 protein as sera from COVID-19 patients. Therefore, suppression of neutrophil elastase could represent an attractive strategy for improving the efficacy of alum-based injected vaccines for the induction of broad immunity, including mucosal immunity.


Assuntos
Adjuvantes Imunológicos/farmacologia , Compostos de Alúmen/farmacologia , COVID-19/imunologia , COVID-19/terapia , Inibidores Enzimáticos/farmacologia , Elastase de Leucócito/antagonistas & inibidores , SARS-CoV-2/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos/efeitos dos fármacos , COVID-19/tratamento farmacológico , COVID-19/metabolismo , Células HEK293 , Humanos , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Imunidade nas Mucosas/efeitos dos fármacos , Imunidade nas Mucosas/imunologia , Imunoglobulina A/imunologia , Elastase de Leucócito/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/imunologia , Suínos , Células Th1/imunologia
4.
Molecules ; 26(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34443621

RESUMO

There are few novel therapeutic options available for companion animals, and medications rely heavily on repurposed drugs developed for other species. Considering the diversity of species and breeds in companion animal medicine, comprehensive PK exposures in the companion animal patient is often lacking. The purpose of this paper was to assess the pharmacokinetics after oral and intravenous dosing in domesticated animal species (dogs, cats, and horses) of a novel soluble epoxide hydrolase inhibitor, EC1728, being developed for the treatment of pain in animals. Results: Intravenous and oral administration revealed that bioavailability was similar for dogs, and horses (42 and 50% F) but lower in mice and cats (34 and 8%, respectively). Additionally, clearance was similar between cats and mice, but >2× faster in cats vs. dogs and horses. Efficacy with EC1728 has been demonstrated in mice, dogs, and horses, and despite the rapid clearance of EC1728 in cats, analgesic efficacy was demonstrated in an acute pain model after intravenous but not oral dosing. Conclusion: These results demonstrate that exposures across species can vary, and investigation of therapeutic exposures in target species is needed to provide adequate care that addresses efficacy and avoids toxicity.


Assuntos
Desenvolvimento de Medicamentos , Inibidores Enzimáticos/metabolismo , Epóxido Hidrolases/antagonistas & inibidores , Animais , Disponibilidade Biológica , Gatos , Cães , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/química , Cavalos , Camundongos , Solubilidade , Especificidade da Espécie
5.
Inorg Chem ; 60(17): 13051-13061, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34369147

RESUMO

The facile modification of the ligands in organometallic Ru(II)-arene complexes offers more opportunities to optimize their pharmacological profiles. Herein, three Ru(II)-arene complexes containing a glutathione S-transferase (GST) inhibitor (NBDHEX) in chelate ligand have been designed and synthesized in this study. In vitro results indicated that the ligation with NBDHEX significantly increased the activities and selectivities of the organometallic Ru(II)-arene complexes against tumor cells, especially complex 3, which was the most active compound among the tested compounds. DFT calculations and hydrolysis results demonstrated that complex 3 with more alkyl groups in the arene ligand has increased electron density at the Ru(II) center as compared with complexes 1 and 2, thus resulting in the improved hydrolysis rate, which may be responsible for its higher anticancer activity. Further studies showed that complexes 1-3 can cause the loss of the mitochondrial membrane potential and upregulate the expression of Bcl-2 and Bax in A549 cells, suggesting that complexes 1-3-induced cell death may be mediated via the mitochondrial apoptotic pathway. Thus, these findings suggested that simultaneous modification of the chelate ligands and arene rings in the organometallic Ru(II)-arene complexes is an effective way to improve their pharmacological properties.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/antagonistas & inibidores , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Complexos de Coordenação/síntese química , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Estrutura Molecular , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Rutênio/química , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismo
6.
Molecules ; 26(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34443550

RESUMO

To confirm that the ß-phenyl-α,ß-unsaturated thiocarbonyl (PUSTC) scaffold, similar to the ß-phenyl-α,ß-unsaturated carbonyl (PUSC) scaffold, acts as a core inhibitory structure for tyrosinase, twelve (Z)-5-(substituted benzylidene)-4-thioxothiazolidin-2-one ((Z)-BTTZ) derivatives were designed and synthesized. Seven of the twelve derivatives showed stronger inhibitory activity than kojic acid against mushroom tyrosinase. Compound 2b (IC50 = 0.47 ± 0.97 µM) exerted a 141-fold higher inhibitory potency than kojic acid. Kinetic studies' results confirmed that compounds 2b and 2f are competitive tyrosinase inhibitors, which was supported by high binding affinities with the active site of tyrosinase by docking simulation. Docking results using a human tyrosinase homology model indicated that 2b and 2f might potently inhibit human tyrosinase. In vitro assays of 2b and 2f were conducted using B16F10 melanoma cells. Compounds 2b and 2f significantly and concentration-dependently inhibited intracellular melanin contents, and the anti-melanogenic effects of 2b at 10 µM and 2f at 25 µM were considerably greater than the inhibitory effect of kojic acid at 25 µM. Compounds 2b and 2f similarly inhibited cellular tyrosinase activity and melanin contents, indicating that the anti-melanogenic effects of both were due to tyrosinase inhibition. A strong binding affinity with the active site of tyrosinase and potent inhibitions of mushroom tyrosinase, cellular tyrosinase activity, and melanin generation in B16F10 cells indicates the PUSTC scaffold offers an attractive platform for the development of novel tyrosinase inhibitors.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Melaninas/biossíntese , Tiazóis/química , Tiazóis/farmacologia , Linhagem Celular Tumoral , Simulação por Computador , Inibidores Enzimáticos/metabolismo , Humanos , Cinética , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/química , Monofenol Mono-Oxigenase/metabolismo , Conformação Proteica , Relação Estrutura-Atividade , Tiazóis/metabolismo
7.
Molecules ; 26(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443596

RESUMO

FAH domain containing protein 1 (FAHD1) acts as oxaloacetate decarboxylase in mitochondria, contributing to the regulation of the tricarboxylic acid cycle. Guided by a high-resolution X-ray structure of FAHD1 liganded by oxalate, the enzymatic mechanism of substrate processing is analyzed in detail. Taking the chemical features of the FAHD1 substrate oxaloacetate into account, the potential inhibitor structures are deduced. The synthesis of drug-like scaffolds afforded first-generation FAHD1-inhibitors with activities in the low micromolar IC50 range. The investigations disclosed structures competing with the substrate for binding to the metal cofactor, as well as scaffolds, which may have a novel binding mode to FAHD1.


Assuntos
Inibidores Enzimáticos/farmacologia , Hidrolases/antagonistas & inibidores , Inibidores Enzimáticos/metabolismo , Humanos , Hidrolases/química , Hidrolases/metabolismo , Simulação de Acoplamento Molecular , Conformação Proteica
8.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360977

RESUMO

Inhibition of ruminal microbial urease is of particular interest due to its crucial role in regulating urea-N utilization efficiency and nitrogen pollution in the livestock industry. Acetohydroxamic acid (AHA) is currently the only commercially available urease inhibitor, but it has adverse side effects. The urease accessory protein UreG, which facilitates the functional incorporation of the urease nickel metallocentre, has been proposed in developing urease inhibitor through disrupting urease maturation. The objective of this study was to screen natural compounds as potential urease inhibitors by targeting UreG in a predominant ruminal microbial urease. In silico screening and in vitro tests for potential inhibitors were performed using molecular docking and an assay for the GTPase activity of UreG. Chelerythrine chloride was selected as a potential urease inhibitor of UreG with an inhibition concentration IC50 value of 18.13 µM. It exhibited mixed inhibition, with the Ki value being 26.28 µM. We further explored its inhibition mechanism using isothermal titration calorimetry (ITC) and circular dichroism (CD) spectroscopy, and we found that chelerythrine chloride inhibited the binding of nickel to UreG and induced changes in the secondary structure, especially the α-helix and ß-sheet of UreG. Chelerythrine chloride formed a pi-anion interaction with the Asp41 residue of UreG, which is an important residue in initiating the conformational changes of UreG. In conclusion, chelerythrine chloride exhibited a potential inhibitory effect on urease, which provided new evidence for strategies to develop novel urease inhibitors targeting UreG to reduce nitrogen excretion from ruminants.


Assuntos
Proteínas de Bactérias/antagonistas & inibidores , Benzofenantridinas/farmacologia , Inibidores Enzimáticos/farmacologia , Proteínas de Ligação a Fosfato/antagonistas & inibidores , Rúmen/microbiologia , Amônia/metabolismo , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Benzofenantridinas/química , Sítios de Ligação , Bovinos , Inibidores Enzimáticos/química , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Proteínas de Ligação a Fosfato/química , Proteínas de Ligação a Fosfato/metabolismo , Ligação Proteica
9.
Int J Mol Sci ; 22(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34445315

RESUMO

A common mechanism in which glucocorticoids participate is suggested in the pathogenesis of such metabolic diseases as obesity, metabolic syndrome, or Cushing's syndrome. The enzyme involved in the control of the availability of cortisol, the active form of the glucocorticoid for the glucocorticoid receptor, is 11ß-HSD1. Inhibition of 11ß-HSD1 activity may bring beneficial results for the alleviation of the course of metabolic diseases such as metabolic syndrome, Cushing's syndrome or type 2 diabetes. In this work, we obtained 10 novel 2-(adamantan-1-ylamino)thiazol-4(5H)-one derivatives containing different substituents at C-5 of thiazole ring and tested their activity towards inhibition of two 11ß-HSD isoforms. For most of them, over 50% inhibition of 11ß-HSD1 and less than 45% inhibition of 11ß-HSD2 activity at the concentration of 10 µM was observed. The binding energies found during docking simulations for 11ß-HSD1 correctly reproduced the experimental IC50 values for analyzed compounds. The most active compound 2-(adamantan-1-ylamino)-1-thia-3-azaspiro[4.5]dec-2-en-4-one (3i) inhibits the activity of isoform 1 by 82.82%. This value is comparable to the known inhibitor-carbenoxolone. The IC50 value is twice the value determined by us for carbenoxolone, however inhibition of the enzyme isoform 2 to a lesser extent makes it an excellent material for further tests.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Inibidores Enzimáticos/síntese química , Simulação de Acoplamento Molecular , Tiazóis/síntese química , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/química , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Adamantano/química , Sítios de Ligação , Inibidores Enzimáticos/farmacologia , Hidrocortisona/química , Hidrocortisona/metabolismo , Ligação Proteica , Tiazóis/farmacologia
10.
Int J Mol Sci ; 22(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34445316

RESUMO

Inhibition of pyruvate dehydrogenase kinase (PDK) emerged as a potential strategy for treatment of cancer and metabolic disorders. Dichloroacetate (DCA), a prototypical PDK inhibitor, reduces the abundance of some PDK isoenzymes. However, the underlying mechanisms are not fully characterized and may differ across cell types. We determined that DCA reduced the abundance of PDK1 in breast (MDA-MB-231) and prostate (PC-3) cancer cells, while it suppressed both PDK1 and PDK2 in skeletal muscle cells (L6 myotubes). The DCA-induced PDK1 suppression was partially dependent on hypoxia-inducible factor-1α (HIF-1α), a transcriptional regulator of PDK1, in cancer cells but not in L6 myotubes. However, the DCA-induced alterations in the mRNA and the protein levels of PDK1 and/or PDK2 did not always occur in parallel, implicating a role for post-transcriptional mechanisms. DCA did not inhibit the mTOR signaling, while inhibitors of the proteasome or gene silencing of mitochondrial proteases CLPP and AFG3L2 did not prevent the DCA-induced reduction of the PDK1 protein levels. Collectively, our results suggest that DCA reduces the abundance of PDK in an isoform-dependent manner via transcriptional and post-transcriptional mechanisms. Differential response of PDK isoenzymes to DCA might be important for its pharmacological effects in different types of cells.


Assuntos
Ácido Dicloroacético/farmacologia , Inibidores Enzimáticos/farmacologia , Fibras Musculares Esqueléticas/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil/antagonistas & inibidores , Proteases Dependentes de ATP/antagonistas & inibidores , Proteases Dependentes de ATP/metabolismo , ATPases Associadas a Diversas Atividades Celulares/antagonistas & inibidores , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Animais , Linhagem Celular Tumoral , Endopeptidase Clp/antagonistas & inibidores , Endopeptidase Clp/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Células PC-3 , Piruvato Desidrogenase Quinase de Transferência de Acetil/genética , Piruvato Desidrogenase Quinase de Transferência de Acetil/metabolismo , Ratos
11.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361017

RESUMO

Glycogen synthase kinase-3 beta (GSK-3ß) is an enzyme pertinently linked to neurodegenerative diseases since it is associated with the regulation of key neuropathological features in the central nervous system. Among the different kinds of inhibitors of this kinase, the allosteric ones stand out due to their selective and subtle modulation, lowering the chance of producing side effects. The mechanism of GSK-3ß allosteric modulators may be considered still vague in terms of elucidating a well-defined binding pocket and a bioactive pose for them. In this context, we propose to reinvestigate and reinforce such knowledge by the application of an extensive set of in silico methodologies, such as cavity detection, ligand 3D shape analysis and docking (with robust validation of corresponding protocols), and molecular dynamics. The results here obtained were consensually consistent in furnishing new structural data, in particular by providing a solid bioactive pose of one of the most representative GSK-3ß allosteric modulators. We further applied this to the prospect for new compounds by ligand-based virtual screening and analyzed the potential of the two obtained virtual hits by quantum chemical calculations. All potential hits achieved will be subsequently tested by in vitro assays in order to validate our approaches as well as to unveil novel chemical entities as GSK-3ß allosteric modulators.


Assuntos
Sítio Alostérico , Glicogênio Sintase Quinase 3 beta/química , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/farmacologia , Regulação Alostérica , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Fármacos Neuroprotetores/química , Ligação Proteica
12.
J Enzyme Inhib Med Chem ; 36(1): 1839-1859, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34338119

RESUMO

A series of [1]benzothieno[2,3-c]pyridines was synthesised. Most compounds were chosen by NCI-USA to evaluate their anticancer activity. Compounds 5a-c showed prominent growth inhibition against most cell lines. 5c was selected at five dose concentration levels. It exhibited potent broad-spectrum anticancer activity with a GI50 of 4 nM-37 µM. Cytotoxicity of 5a-c was further evaluated against prostate, renal, and breast cancer cell lines. 5c showed double and quadruple the activity of staurosporine and abiraterone, respectively, against the PC-3 cell line with IC50 2.08 µM. The possible mechanism of anti-prostate cancer was explored via measuring the CYP17 enzyme activity in mice prostate cancer models compared to abiraterone. The results revealed that 5c suppressed the CYP17 enzyme to 15.80 nM. Moreover, it was found to be equipotent to abiraterone in testosterone production. Cell cycle analysis and apoptosis were performed. Additionally, the ADME profile of compound 5c demonstrated both good oral bioavailability and metabolic stability.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Piridinas/química , Piridinas/farmacologia , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Linhagem Celular Tumoral , Simulação por Computador , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Humanos , Masculino , Camundongos , Neoplasias da Próstata/patologia , Piridinas/síntese química , Piridinas/farmacocinética , Análise Espectral/métodos , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361729

RESUMO

Tyrosinase (TYR) is a type III copper oxidase present in fungi, plants and animals. The inhibitor of human TYR plays a vital role in pharmaceutical and cosmetic fields by preventing synthesis of melanin in the skin. To search for an effective TYR inhibitor from various plant extracts, a kinetic study of TYR inhibition was performed with mushroom TYR. Among Panax ginseng, Alpinia galanga, Vitis vinifera and Moringa oleifera, the extracts of V. vinifera seed, A. galanga rhizome and M. oleifera leaf reversibly inhibited TYR diphenolase activity with IC50 values of 94.8 ± 0.2 µg/mL, 105.4 ± 0.2 µg/mL and 121.3 ± 0.4 µg/mL, respectively. Under the same conditions, the IC50 values of the representative TYR inhibitors of ascorbic acid and kojic acid were found at 235.7 ± 1.0 and 192.3 ± 0.4 µg/mL, respectively. An inhibition kinetics study demonstrated mixed-type inhibition of TYR diphenolase by A. galanga and V. vinifera, whereas a rare uncompetitive inhibition pattern was found from M. oleifera with an inhibition constant of Kii 73 µg/mL. Phytochemical investigation by HPLC-MS proposed luteolin as a specific TYR diphenolase ES complex inhibitor, which was confirmed by the inhibition kinetics of luteolin. The results clearly showed that studying TYR inhibition kinetics with plant extract mixtures can be utilized for the screening of specific TYR inhibitors.


Assuntos
Inibidores Enzimáticos/farmacologia , Proteínas Fúngicas/antagonistas & inibidores , Luteolina/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Moringa oleifera/química , Agaricales/química , Agaricales/enzimologia , Alpinia/química , Ácido Ascórbico/química , Ácido Ascórbico/isolamento & purificação , Ácido Ascórbico/farmacologia , Ensaios Enzimáticos , Inibidores Enzimáticos/química , Proteínas Fúngicas/isolamento & purificação , Ensaios de Triagem em Larga Escala , Concentração Inibidora 50 , Cinética , Luteolina/química , Luteolina/isolamento & purificação , Monofenol Mono-Oxigenase/isolamento & purificação , Panax/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Pironas/química , Pironas/isolamento & purificação , Pironas/farmacologia , Rizoma/química , Sementes/química , Vitis/química
14.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361759

RESUMO

Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), ß-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 µg/mL, a scavenging capacity SC50 of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC50 of 146 ± 20 µg/mL.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Croton/química , Inibidores Enzimáticos/química , Óleos Voláteis/química , Folhas de Planta/química , Monoterpenos Acíclicos/química , Monoterpenos Acíclicos/isolamento & purificação , Alcenos/química , Alcenos/isolamento & purificação , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Benzotiazóis/antagonistas & inibidores , Compostos de Bifenilo/antagonistas & inibidores , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Monoterpenos Cicloexânicos/química , Monoterpenos Cicloexânicos/isolamento & purificação , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Sesquiterpenos Monocíclicos/química , Sesquiterpenos Monocíclicos/isolamento & purificação , Picratos/antagonistas & inibidores , Sesquiterpenos Policíclicos/química , Sesquiterpenos Policíclicos/isolamento & purificação , Sesquiterpenos de Germacrano/química , Sesquiterpenos de Germacrano/isolamento & purificação , Ácidos Sulfônicos/antagonistas & inibidores , alfa-Glucosidases/química
15.
Viruses ; 13(8)2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34452451

RESUMO

SARS-CoV-2 has caused an extensive pandemic of COVID-19 all around the world. Key viral enzymes are suitable molecular targets for the development of new antivirals against SARS-CoV-2 which could represent potential treatments of the corresponding disease. With respect to its essential role in the replication of viral RNA, RNA-dependent RNA polymerase (RdRp) is one of the prime targets. HeE1-2Tyr and related derivatives were originally discovered as inhibitors of the RdRp of flaviviruses. Here, we present that these pyridobenzothiazole derivatives also significantly inhibit SARS-CoV-2 RdRp, as demonstrated using both polymerase- and cell-based antiviral assays.


Assuntos
Antivirais/farmacologia , Benzotiazóis/farmacologia , RNA-Polimerase RNA-Dependente de Coronavírus/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , SARS-CoV-2/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Alanina/análogos & derivados , Alanina/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , SARS-CoV-2/enzimologia , SARS-CoV-2/fisiologia
16.
Molecules ; 26(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34361571

RESUMO

Inducible nitric oxide synthase (iNOS) is a crucial enzyme involved in monocyte cell response towards inflammation, and it is responsible for the production of sustained amounts of nitric oxide. This free radical molecule is involved in the defense against pathogens; nevertheless, its continuous and dysregulated production contributes to the development of several pathological conditions, including inflammatory and autoimmune diseases. In the present study, we investigated the effects of two new iNOS inhibitors, i.e., 4-(ethanimidoylamino)-N-(4-fluorophenyl)benzamide hydrobromide (FAB1020) and N-{3-[(ethanimidoylamino)methyl]benzyl}-l-prolinamidedihydrochloride (CM554), on human LPS-stimulated monocytes, using the 1400 W compound as a comparison. Our results show that CM544 and FAB1020 are selective and decrease cytotoxicity, IL-6 secretion and LPS-stimulated monocyte migration. Furthermore, the modulation of iNOS, nitrotyrosine and Nrf2 were analyzed at the protein level. Based on the collected preliminary results, the promising therapeutic value of the investigated compounds emerges, as they appear able to modulate the pro-inflammatory LPS-stimulated response in the low micromolar range in human monocytes.


Assuntos
Amidinas/farmacologia , Inibidores Enzimáticos/farmacologia , Lipopolissacarídeos/toxicidade , Monócitos/enzimologia , Óxido Nítrico Sintase Tipo II , Prolina/análogos & derivados , Humanos , Interleucina-6/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Prolina/farmacologia
17.
Molecules ; 26(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34443540

RESUMO

Helicobacter pylori (H. pylori) is a pathogen that can remain in the stomach of an infected person for their entire life. As a result, this leads to the development of severe gastric diseases such as gastric cancer. In addition, current therapies have several problems including antibiotics resistance. Therefore, new practical options to eliminate this bacterium, and its induced affections, are required to avoid morbidity and mortality worldwide. One strategy in the search for new drugs is to detect compounds that inhibit a limiting step in a central metabolic pathway of the pathogen of interest. In this work, we tested 55 compounds to gain insights into their possible use as new inhibitory drugs of H. pylori glucose-6-phosphate dehydrogenase (HpG6PD) activity. The compounds YGC-1; MGD-1, MGD-2; TDA-1; and JMM-3 with their respective scaffold 1,3-thiazolidine-2,4-dione; 1H-benzimidazole; 1,3-benzoxazole, morpholine, and biphenylcarbonitrile showed the best inhibitory activity (IC50 = 310, 465, 340, 204 and 304 µM, respectively). We then modeled the HpG6PD protein by homology modeling to conduct an in silico study of the chemical compounds and discovers its possible interactions with the HpG6PD enzyme. We found that compounds can be internalized at the NADP+ catalytic binding site. Hence, they probably exert a competitive inhibitory effect with NADP+ and a non-competitive or uncompetitive effect with G6P, that of the compounds binding far from the enzyme's active site. Based on these findings, the tested compounds inhibiting HpG6PD represent promising novel drug candidates against H. pylori.


Assuntos
Simulação por Computador , Inibidores Enzimáticos/farmacologia , Glucosefosfato Desidrogenase/antagonistas & inibidores , Helicobacter pylori/enzimologia , Vetores Genéticos/metabolismo , Glucosefosfato Desidrogenase/química , Glucosefosfato Desidrogenase/metabolismo , Helicobacter pylori/efeitos dos fármacos , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Proteínas Recombinantes/isolamento & purificação , Homologia Estrutural de Proteína
18.
Nutrients ; 13(8)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34444856

RESUMO

With a yearly production of about 39 million tons, brewer's spent grain (BSG) is the most abundant brewing industry byproduct. Because it is rich in fiber and protein, it is commonly used as cattle feed but could also be used within the human diet. Additionally, it contains many bioactive substances such as hydroxycinnamic acids that are known to be antioxidants and potent inhibitors of enzymes of glucose metabolism. Therefore, our study aim was to prepare different extracts-A1-A7 (solid-liquid extraction with 60% acetone); HE1-HE6 (alkaline hydrolysis followed by ethyl acetate extraction) and HA1-HA3 (60% acetone extraction of alkaline residue)-from various BSGs which were characterized for their total phenolic (TPC) and total flavonoid (TFC) contents, before conducting in vitro studies on their effects on the glucose metabolism enzymes α-amylase, α-glucosidase, dipeptidyl peptidase IV (DPP IV), and glycogen phosphorylase α (GPα). Depending on the extraction procedures, TPCs ranged from 20-350 µg gallic acid equivalents/mg extract and TFCs were as high as 94 µg catechin equivalents/mg extract. Strong inhibition of glucose metabolism enzymes was also observed: the IC50 values for α-glucosidase inhibition ranged from 67.4 ± 8.1 µg/mL to 268.1 ± 29.4 µg/mL, for DPP IV inhibition they ranged from 290.6 ± 97.4 to 778.4 ± 95.5 µg/mL and for GPα enzyme inhibition from 12.6 ± 1.1 to 261 ± 6 µg/mL. However, the extracts did not strongly inhibit α-amylase. In general, the A extracts from solid-liquid extraction with 60% acetone showed stronger inhibitory potential towards a-glucosidase and GPα than other extracts whereby no correlation with TPC or TFC were observed. Additionally, DPP IV was mainly inhibited by HE extracts but the effect was not of biological relevance. Our results show that BSG is a potent source of α-glucosidase and GPα inhibitors, but further research is needed to identify these bioactive compounds within BSG extracts focusing on extracts from solid-liquid extraction with 60% acetone.


Assuntos
Grão Comestível/química , Inibidores Enzimáticos/farmacologia , Glucose/metabolismo , Glicosídeo Hidrolases/efeitos dos fármacos , Extratos Vegetais/farmacologia , Antioxidantes/farmacologia , Flavonoides/farmacologia , Glicosídeo Hidrolases/antagonistas & inibidores , Humanos , Fenóis/farmacologia
19.
Molecules ; 26(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34443699

RESUMO

Three α,α-difluorophosphonate derivatives of fosmidomycin were synthesized from diethyl 1,1-difluorobut-3-enylphosphonate and were evaluated on Escherichia coli. Two of them are among the best 1-deoxy-d-xylulose 5-phosphate reductoisomerase inhibitors, with IC50 in the nM range, much better than fosmidomycin, the reference compound. They also showed an enhanced antimicrobial activity against E. coli on Petri dishes in comparison with the corresponding phosphates and the non-fluorinated phosphonate.


Assuntos
Antibacterianos/farmacologia , Fosfomicina/análogos & derivados , Ácidos Hidroxâmicos/farmacologia , Aldose-Cetose Isomerases/antagonistas & inibidores , Aldose-Cetose Isomerases/metabolismo , Farmacorresistência Bacteriana/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Fosfomicina/síntese química , Fosfomicina/química , Fosfomicina/farmacologia , Testes de Sensibilidade Microbiana
20.
Biomolecules ; 11(7)2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34356672

RESUMO

In the search for new therapeutic strategies to contrast SARS-CoV-2, we here studied the interaction of polydatin (PD) and resveratrol (RESV)-two natural stilbene polyphenols with manifold, well known biological activities-with Spike, the viral protein essential for virus entry into host cells, and ACE2, the angiotensin-converting enzyme present on the surface of multiple cell types (including respiratory epithelial cells) which is the main host receptor for Spike binding. Molecular Docking simulations evidenced that both compounds can bind Spike, ACE2 and the ACE2:Spike complex with good affinity, although the interaction of PD appears stronger than that of RESV on all the investigated targets. Preliminary biochemical assays revealed a significant inhibitory activity of the ACE2:Spike recognition with a dose-response effect only in the case of PD.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/tratamento farmacológico , Glucosídeos/farmacologia , Resveratrol/farmacologia , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/metabolismo , Estilbenos/farmacologia , COVID-19/metabolismo , Descoberta de Drogas , Medicamentos de Ervas Chinesas/farmacologia , Inibidores Enzimáticos/farmacologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica/efeitos dos fármacos , SARS-CoV-2/metabolismo
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