Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 664
Filtrar
Más filtros

Medicinas Complementárias
Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Metallomics ; 14(1)2022 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-34951920

RESUMEN

Copper (II) ions appear to be involved in the Alzheimer's disease and seem to influence the aggregation of the amyloid-ß1-42 (Aß1-42) peptide. However, data are not conclusive and still not subject to consensus, copper (II) being suspected to either promote or inhibit aggregation. To address this question, CE-ICP-MS (capillary electrophoresis-inductively coupled plasma-mass spectrometry) hyphenation was proposed as a complementary tool to follow the distribution of copper in the different oligomeric forms, at different substoichiometries and different incubation times. Results clearly indicated the formation of several negatively charged copper complexes and showed the enhancement of the aggregation rate with copper concentration. Moreover, the variations of copper (II) speciation suggest different aggregation pathway, even for substoichiometric ratios.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Cobre/química , Humanos , Fragmentos de Péptidos/química
2.
Biochem Biophys Res Commun ; 550: 120-126, 2021 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-33691198

RESUMEN

Ralstonia solanacearum causes bacterial wilt disease in a broad range of plants, primarily through type Ⅲ secreted effectors. However, the R. solanacearum effectors promoting susceptibility in host plants remain limited. In this study, we determined that the R. solanacearum effector RipV2 functions as a novel E3 ubiquitin ligase (NEL). RipV2 was observed to be locali in the plasma membrane after translocatio into plant cells. Transient expression of RipV2 in Nicotiana benthamiana could induce cell death and suppress the flg22-induced pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) responses, mediating such effects as attenuation of the expression of several PTI-related genes and ROS bursts. Furthermore, we demonstrated that the conserved catalytic residue is highly important for RipV2. Transient expression of the E3 ubiquitin ligase catalytic mutant RipV2 C403A alleviated the PTI suppression ability and cell death induction, indicating that RipV2 requires its E3 ubiquitin ligase activity for its role in plant-microbe interactions. More importantly, mutation of RipV2 in R. solanacearum reduces the virulence of R. solanacearum on potato. In conclusion, we identified a NEL effector that is required for full virulence of R. solanacearum by suppressing plant PTI.


Asunto(s)
Moléculas de Patrón Molecular Asociado a Patógenos/antagonistas & inhibidores , Inmunidad de la Planta , Ralstonia solanacearum/enzimología , Solanum tuberosum/inmunología , Solanum tuberosum/microbiología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Virulencia , Secuencias de Aminoácidos , Biocatálisis , Muerte Celular , Membrana Celular/enzimología , Cisteína/metabolismo , Flagelina/química , Flagelina/inmunología , Moléculas de Patrón Molecular Asociado a Patógenos/inmunología , Fragmentos de Péptidos/química , Fragmentos de Péptidos/inmunología , Ralstonia solanacearum/genética , Ubiquitina-Proteína Ligasas/química , Virulencia/genética
3.
Food Funct ; 12(4): 1415-1431, 2021 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-33527945

RESUMEN

About one in three people are affected by anxiety disorders during their lifetime. Anxiety episodes can be brief due to a stressful event, but anxiety disorders can last at least 6 months. A wide variety of therapeutic drugs are available for the treatment of anxiety disorders, but due to the associated side effects of these anxiolytics, it is interesting to find alternatives. Some food protein hydrolysates or active peptide fragments present in such hydrolysates provide a natural and promising mean for preventing certain forms of anxiety. To date, only a small number of hydrolysates or peptides from food proteins with anxiolytic-like activity have been characterized. Most of these hydrolysates or peptides have displayed potent anxiolytic profiles in animal or clinical studies. The results suggest that these molecules may exert their effects at different levels. This paper reviews the data of the structure/activity relationship, physiological effects displayed in in vitro and in vivo assays, bioavailability, and safety profiles of anxiolytic peptides.


Asunto(s)
Ansiedad/tratamiento farmacológico , Proteínas en la Dieta/análisis , Hidrolisados de Proteína/uso terapéutico , Animales , Ansiolíticos/farmacología , Trastornos de Ansiedad/tratamiento farmacológico , Caseínas/química , Caseínas/uso terapéutico , Proteínas de Peces/química , Humanos , Proteínas de la Leche/química , Oligopéptidos/uso terapéutico , Fragmentos de Péptidos/química , Fragmentos de Péptidos/uso terapéutico , Ribulosa-Bifosfato Carboxilasa/uso terapéutico , Proteínas de Soja/química
4.
Biochem Biophys Res Commun ; 545: 125-131, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33548625

RESUMEN

Bromodomain and PHD finger containing transcription factor (BPTF) is a multidomain protein that regulates the transcription of chromatin and is related to many cancers. Herein, we report the screening-based discovery of Cpd1, a compound with micromolar affinity to the BPTF bromodomain. Through structure-guided optimization, we synthesized a variety of new inhibitors. Among these compounds, Cpd8 and Cpd10 were highly potent and selective inhibitors, with KD values of 428 nM and 655 nM in ITC assays, respectively. The high activity was explained by the cocrystal structure of Cpd8 in complex with the BPTF bromodomain protein. Cpd8 and Cpd10 were able to stabilize the BPTF bromodomain protein in cells in a cellular thermal shift assay (CETSA). Cpd8 downregulated c-MYC expression in A549 cells. All experiments prove that these two compounds are potential BPTF inhibitors.


Asunto(s)
Proteínas del Tejido Nervioso/antagonistas & inhibidores , Factores de Transcripción/antagonistas & inhibidores , Células A549 , Antígenos Nucleares/química , Antígenos Nucleares/genética , Calorimetría , Cristalografía por Rayos X , Diseño de Fármacos , Descubrimiento de Drogas , Evaluación Preclínica de Medicamentos , Fluorometría , Regulación de la Expresión Génica/efectos de los fármacos , Genes myc , Células HEK293 , Humanos , Modelos Moleculares , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Fragmentos de Péptidos/antagonistas & inhibidores , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Dominios Proteicos , Estabilidad Proteica/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/efectos de los fármacos , Proteínas Recombinantes/genética , Relación Estructura-Actividad , Factores de Transcripción/química , Factores de Transcripción/genética
5.
Commun Biol ; 4(1): 62, 2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-33437023

RESUMEN

Recent computational advancements in the simulation of biochemical processes allow investigating the mechanisms involved in protein regulation with realistic physics-based models, at an atomistic level of resolution. These techniques allowed us to design a drug discovery approach, named Pharmacological Protein Inactivation by Folding Intermediate Targeting (PPI-FIT), based on the rationale of negatively regulating protein levels by targeting folding intermediates. Here, PPI-FIT was tested for the first time on the cellular prion protein (PrP), a cell surface glycoprotein playing a key role in fatal and transmissible neurodegenerative pathologies known as prion diseases. We predicted the all-atom structure of an intermediate appearing along the folding pathway of PrP and identified four different small molecule ligands for this conformer, all capable of selectively lowering the load of the protein by promoting its degradation. Our data support the notion that the level of target proteins could be modulated by acting on their folding pathways, implying a previously unappreciated role for folding intermediates in the biological regulation of protein expression.


Asunto(s)
Evaluación Preclínica de Medicamentos/métodos , Enfermedades por Prión/tratamiento farmacológico , Proteínas Priónicas/química , Proteínas Priónicas/metabolismo , Pliegue de Proteína , Animales , Sitios de Unión , Simulación por Computador , Retículo Endoplásmico/metabolismo , Fibroblastos , Células HEK293 , Humanos , Ligandos , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Ratones , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Procesamiento Proteico-Postraduccional , Reproducibilidad de los Resultados
6.
Int J Biol Macromol ; 173: 56-65, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33465364

RESUMEN

Here, we have studied the ameliorative effects of Withania somnifera derivatives (Withanolide A, Withanolide B, Withanoside IV, and Withanoside V) on the fibril formation of amyloid-ß 42 for Alzheimer's disease. We analyzed reduction in the aggregation of ß amyloid protein with these Ashwagandha derivatives by Thioflavin T assay in the oligomeric and fibrillar state. We have tested the cytotoxic activity of these compounds against human SK-N-SH cell line for 48 h, and the IC 50 value found to be 28.61 ± 2.91, 14.84 ± 1.45, 18.76 ± 0.76 and 30.14 ± 2.59 µM, respectively. After the treatment of the cells with half the concentration of IC 50 value, there was a remarkable decrease in the number of apoptotic cells stained by TUNEL assay indicating the DNA damage and also observed significant decrease of reactive oxygen species. Also, the binding and molecular stability of these derivatives with amyloid ß was also studied using bioinformatics tools where these molecules were interacted at LVFFA region which is inhibition site of amyloid-ß1 42. These studies revealed that the Withanolides and Withanosides interact with the hydrophobic core of amyloid-ß 1-42 in the oligomeric stage, preventing further interaction with the monomers and diminishing aggregation.


Asunto(s)
Péptidos beta-Amiloides/antagonistas & inhibidores , Ergosterol/análogos & derivados , Fármacos Neuroprotectores/farmacología , Fragmentos de Péptidos/antagonistas & inhibidores , Withania/química , Witanólidos/farmacología , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/metabolismo , Sitios de Unión , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Ergosterol/química , Ergosterol/metabolismo , Ergosterol/farmacología , Humanos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/metabolismo , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Extractos Vegetales/química , Agregado de Proteínas/efectos de los fármacos , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Witanólidos/química , Witanólidos/metabolismo
7.
Food Chem ; 341(Pt 2): 128249, 2021 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-33038804

RESUMEN

The metabolic profile of Lavado cocoa was characterized for the first time by NMR spectroscopy, then compared with the profiles of fermented and processed varieties, Natural and commercial cocoa. The significant difference in the contents of theobromine and flavanols prompted us to examine the cocoa varieties to seek correlations between these metabolite concentrations and the anti-amyloidogenic activity reported for cocoa in the literature. We combined NMR spectroscopy, preparative reversed-phase (RP) chromatography, atomic force microscopy, in vitro biochemical and cell assays, to investigate and compare the anti-amyloidogenic properties of extracts and fractions enriched in different metabolite classes. Lavado variety was the most active and the catechins and theobromine were the chemical components of cocoa hindering Aß peptide on-pathway aggregation and toxicity in a human neuroblastoma SH-SY5Y cell line.


Asunto(s)
Cacao/química , Alimentos Fermentados/análisis , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/metabolismo , Antioxidantes/química , Cacao/metabolismo , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión , Cromatografía de Fase Inversa , Flavanonas/análisis , Humanos , Espectroscopía de Resonancia Magnética , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Extractos Vegetales/química , Extractos Vegetales/farmacología , Agregado de Proteínas/efectos de los fármacos , Teobromina/análisis
8.
Ultrason Sonochem ; 71: 105385, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33271422

RESUMEN

Whey protein isolate (WPI) hydrolysates have higher solubility in aqueous phase and enhanced biological properties. Hydrolysis of WPI was optimized using operating pressure (ΔP, bar), number of passes (N), and WPI concentration (C, %) as deciding parameters in hydrodynamic cavitation treatment. The optimum conditions for generation of WPI hydrolysate with full factorial design were 8 bar, 28 passes, and 4.5% WPI concentration yielding 32.69 ± 1.22 mg/mL soluble proteins. WPI hydrolysate showed alterations in binding capacity over WPI. SDS-PAGE and particle size analysis confirmed the hydrolysis of WPI. Spectroscopic, thermal and crystallinity analyses showed typical properties of proteins with slight variations after hydrodynamic cavitation treatment. ABTS, DPPH and FRAP assays of WPI hydrolysate showed 7-66, 9-149, and 0.038-0.272 µmol/mL GAE at 1-10, 0.25-4, and 3-30 mg/mL concentration, respectively. Further, a considerable enhancement in fresh weight, chlorophyll, carotenoids, reducing sugars, total soluble sugars, soluble proteins content and total phenolics content was noticed during in vitro growth of sugarcane in WPI hydrolysate supplemented medium at 50-200 mg/L concentration over the control. The process cost (INR/kg) to hydrolyze WPI was also calculated.


Asunto(s)
Hidrodinámica , Fragmentos de Péptidos/química , Proteína de Suero de Leche/química , Hidrólisis , Presión , Solubilidad
9.
Toxicology ; 447: 152612, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33171268

RESUMEN

Mitochondria are subcellular organelles involved in cell metabolism and cell life-cycle. Their role in apoptosis regulation makes them an interesting target of new drugs for dealing with cancer or rare diseases. Several peptides and proteins isolated from animal and plant sources are known for their therapeutic properties and have been tested on cancer cell-lines and xenograft murine models, highlighting their ability in inducing cell-death by triggering mitochondrial apoptosis. Some of those molecules have been even approved as drugs. Conversely, many other bioactive compounds are still under investigation for their proapoptotic properties. In this review we report about a group of peptides, isolated from animal venoms, with potential therapeutic properties related to their ability in triggering mitochondrial apoptosis. This class of compounds is known with different names, such as mitochondriotoxins or mitocans.


Asunto(s)
Apoptosis/efectos de los fármacos , Bilis , Factores Biológicos/toxicidad , Miel , Mitocondrias/metabolismo , Fragmentos de Péptidos/toxicidad , Secuencia de Aminoácidos , Animales , Apoptosis/fisiología , Factores Biológicos/química , Factores Biológicos/aislamiento & purificación , Humanos , Péptidos y Proteínas de Señalización Intercelular/química , Péptidos y Proteínas de Señalización Intercelular/aislamiento & purificación , Péptidos y Proteínas de Señalización Intercelular/toxicidad , Mitocondrias/química , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Fragmentos de Péptidos/química , Fragmentos de Péptidos/aislamiento & purificación , Estructura Secundaria de Proteína , Venenos de Avispas/química , Venenos de Avispas/aislamiento & purificación , Venenos de Avispas/toxicidad
10.
PLoS One ; 15(9): e0223815, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32997672

RESUMEN

Allium roseum is an important medicinal and aromatic plant, specific to the North African flora and a rich source of important nutrients and bioactive molecules including flavonoids and organosulfur compounds whose biological activities and pharmacological properties are well known. In the present study, the inhibition of amyloid beta protein toxicity by the ethanolic extract of this plant is investigated for the first time. Preliminary biochemical analyses identified kæmpferol and luteolin-7-o-glucoside as the more abundant phenolic compounds. The effects of A. roseum extract (ARE) on aggregation and aggregate cytotoxicity of amyloid beta-42 (Aß42), whose brain aggregates are a hallmark of Alzheimer's disease, were investigated by biophysical (ThT assay, Dynamic light scattering and transmission electron microscopy) and cellular assays (cytotoxicity, aggregate immunolocalization, ROS measurement and intracellular Ca2+ imaging). The biophysical data suggest that ARE affects the structure of the Aß42 peptide, inhibits its polymerization, and interferes with the path of fibrillogenesis. The data with cultured cells shows that ARE reduces Aß42 aggregate toxicity by inhibiting aggregate binding to the cell membrane and by decreasing both oxidative stress and intracellular Ca2+. Accordingly, ARE could act as a neuroprotective factor against Aß aggregate toxicity in Alzheimer's disease.


Asunto(s)
Allium/química , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/metabolismo , Fármacos Neuroprotectores/farmacología , Fragmentos de Péptidos/metabolismo , Extractos Vegetales/farmacología , Agregación Patológica de Proteínas/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/toxicidad , Calcio/metabolismo , Línea Celular Tumoral , Membrana Celular/metabolismo , Citosol/metabolismo , Evaluación Preclínica de Medicamentos , Dispersión Dinámica de Luz , Etanol/química , Humanos , Microscopía Electrónica de Transmisión , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/aislamiento & purificación , Fármacos Neuroprotectores/uso terapéutico , Estrés Oxidativo/efectos de los fármacos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/toxicidad , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/uso terapéutico , Agregación Patológica de Proteínas/patología , Especies Reactivas de Oxígeno/metabolismo
11.
J Mater Chem B ; 8(36): 8414-8421, 2020 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-32966536

RESUMEN

Due to the number of phosphorylation sites, mono- and multiple-phosphopeptides exhibit significantly different biological effects. Therefore, comprehensive profiles of mono- and multiple-phosphopeptides are vital for the analysis of these biological and pathological processes. However, the most commonly used affinity materials based on metal oxide affinity chromatography (MOAC) show stronger selectivity toward mono-phosphopeptides, thus losing most information on multiple-phosphopeptides. Herein, we report polymer functionalized magnetic nanocomposite microspheres as an ideal platform to efficiently enrich both mono- and multiple-phosphopeptides from complex biological samples. Driven by complementary multiple hydrogen bonding interactions, the composite microspheres exhibited remarkable performance for phosphopeptide enrichment from model proteins and real bio-samples. Excellent selectivity (the molar ratio of nonphosphopeptides/phosphopeptides was 5000 : 1), high enrichment sensitivity (2 fmol) and coverage, as well as high capture rates of multiple-phosphopeptides revealed their great potential in comprehensive phosphoproteomics studies. More importantly, we successfully captured the cancer related phosphopeptides (from the phosphoprotein Stathmin-1) and identified their relevant phosphorylation sites from oral carcinoma patients' saliva and tissue lysate, demonstrating the potential of this material for phosphorylated disease marker detection and discovery.


Asunto(s)
Biomarcadores de Tumor/aislamiento & purificación , Óxido Ferrosoférrico/química , Microesferas , Fosfopéptidos/aislamiento & purificación , Animales , Biomarcadores de Tumor/química , Carcinoma/química , Caseínas/química , Caseínas/aislamiento & purificación , Bovinos , Humanos , Enlace de Hidrógeno , Fenómenos Magnéticos , Masculino , Leche/química , Nanosferas/química , Fragmentos de Péptidos/química , Fragmentos de Péptidos/aislamiento & purificación , Fosfopéptidos/química , Fosforilación , Polímeros/síntesis química , Polímeros/química , Ratas Sprague-Dawley , Saliva/química , Dióxido de Silicio/química , Extracción en Fase Sólida/métodos , Estatmina/química , Estatmina/aislamiento & purificación
12.
J Med Chem ; 63(20): 11691-11706, 2020 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-32960056

RESUMEN

Self-adjuvanting vaccines, wherein an antigenic peptide is covalently bound to an immunostimulating agent, have been shown to be promising tools for immunotherapy. Synthetic Toll-like receptor (TLR) ligands are ideal adjuvants for covalent linking to peptides or proteins. We here introduce a conjugation-ready TLR4 ligand, CRX-527, a potent powerful lipid A analogue, in the generation of novel conjugate-vaccine modalities. Effective chemistry has been developed for the synthesis of the conjugation-ready ligand as well as the connection of it to the peptide antigen. Different linker systems and connection modes to a model peptide were explored, and in vitro evaluation of the conjugates showed them to be powerful immune-activating agents, significantly more effective than the separate components. Mounting the CRX-527 ligand at the N-terminus of the model peptide antigen delivered a vaccine modality that proved to be potent in activation of dendritic cells, in facilitating antigen presentation, and in initiating specific CD8+ T-cell-mediated killing of antigen-loaded target cells in vivo. Synthetic TLR4 ligands thus show great promise in potentiating the conjugate vaccine platform for application in cancer vaccination.


Asunto(s)
Vacunas contra el Cáncer/síntesis química , Glucosamina/análogos & derivados , Lípido A/análogos & derivados , Compuestos Organofosforados/química , Ovalbúmina/química , Receptor Toll-Like 4/inmunología , Adyuvantes Inmunológicos , Animales , Vacunas contra el Cáncer/química , Vacunas contra el Cáncer/inmunología , Citocinas/inmunología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Glucosamina/química , Glucosamina/inmunología , Inmunoglobulina G/sangre , Ligandos , Activación de Linfocitos/efectos de los fármacos , Ratones , Compuestos Organofosforados/inmunología , Ovalbúmina/inmunología , Fragmentos de Péptidos/química , Fragmentos de Péptidos/inmunología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Vacunas Conjugadas
13.
J Dairy Sci ; 103(11): 9923-9935, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32921475

RESUMEN

In casein micelle (CM), Ca is either precipitated in the colloidal calcium phosphate (CCP) stabilized by clusters of phosphoserine (SEP) residues, or is directly bound to SEP (or glutamic and aspartic acids) of caseins without inorganic phosphate. However, it is currently not possible to titrate separately the different micellar Ca forms, making it difficult to assess their respective importance for CM properties and behavior. Both Ca2+ and Mg2+ have the same binding constants with SEP. Moreover, MgHPO4 is more soluble than CaHPO4, and its natural concentration in milk is lower. Thus, upon addition of MgCl2, Mg is mainly exchanged with CM in the bound form, whereas upon addition of CaCl2, Ca is mainly exchanged in the precipitated form. Our objective was to assess the role of the 2 forms of micellar cations (bound and precipitated) during the enzymatic coagulation of cow milk. Magnesium chloride, CaCl2, or KCl (10 mM) were added to milk and pH was adjusted to 6.6 after overnight equilibration. The KCl-supplemented milk was a positive control to assess the effect of the increased ionic strength after MgCl2 and CaCl2 addition. Mineral partition between soluble and colloidal phases after salt addition was assessed both experimentally and by using computer simulation. Enzymatic coagulation was proceeded at 30°C. Hydrolysis of κ-casein was followed by the quantitative determination of caseinomacropeptide released by RP-HPLC, aggregation of para-κ-casein micelles was measured through the evolution of backscattering properties of milk and the gel time and gel firming kinetics were determined using a Chymograph (Chr. Hansen, Horsholm, Denmark). The KCl addition did not affect mineral partition. As expected, CaCl2 addition mainly increased the CCP content, whereas the addition of MgCl2 mainly increased the bound divalent cations content. The kinetics of κ-casein hydrolysis was slowed down after CaCl2 and MgCl2 addition, and was negatively correlated with the concentration of divalent cations in the soluble phase of milk. Aggregation and gel firming curves plotted versus the progress of κ-casein hydrolysis were similar for both CaCl2- and MgCl2-supplemented milk. In view of the dual-binding model for CM assembly, this means that both Ca forms reduce electronegative repulsions between para-micelles by specific charge shielding. Inclusion of 2 Ca forms in structural models for CM allows a more detailed comprehension of how mineral equilibria affect CM properties.


Asunto(s)
Cloruro de Calcio/química , Fosfatos de Calcio/química , Caseínas/química , Cloruro de Magnesio/química , Leche/química , Fragmentos de Péptidos/química , Animales , Calcio de la Dieta/análisis , Simulación por Computador , Micelas , Minerales/química , Fosfatos/química
14.
Eur J Pharm Biopharm ; 156: 97-113, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32911066

RESUMEN

The current study aimed to develop novel peptide dendrimer (PD)-conjugated nanoliposomal formulations of asenapine maleate (ASP) for improvement in the transdermal delivery and pharmacokinetic profile of the drug. Novel arginine-terminated PDs (+/-lipidation) were prepared by solid phase peptide synthesis, followed by conjugation onto ASP nanoliposomes. The nanoliposomes were characterized for particle size (and polydispersity index), zeta potential (ZP), drug entrapment efficiency, shape and morphology, differential scanning calorimetry and FT-IR spectroscopy. Ex vivo skin permeation and retention studies demonstrated considerably higher percutaneous permeation of ASP from the developed nanoliposomes (Q24 = 794.31 ± 54.89 µg/cm2, Jss = 105.40 ± 4.8 µg/cm2/h, ER = 36.85 ± 2.89 for liposomes with lipidated peptide dendrimer (Lipo-PD2)) in comparison with passive diffusion studies (Q24 = 63.09 ± 3.56 µg/cm2, Jss = 3.01 ± 0.23 µg/cm2/h). Confocal Laser Scanning Microscopy (CLSM) confirmed the higher percutaneous penetration of Lipo-PD2 in comparison with liposomes without the dendrimer. In vitro cytotoxicity determined on HaCaT cell line demonstrated CTC50 of >1000 µg/mL for both the synthesized PDs and Lipo-PD2. Pharmacokinetic studies in male Sprague Dawley rats revealed considerably and significantly higher t1/2 = 82.32 ± 14.48 h and AUC0-t = 4403.34 ± 367.10 h.ng/mL, from the developed formulation, compared to orally administered ASP (t1/2 = 21.64 ± 2.53 h and AUC0-t = 2303.55 ± 444.5 h.ng/mL), demonstrating higher bioavailability and longer retention in vivo. Additionally, in vivo skin retention, brain uptake studies and pharmacodynamics of the developed formulations were investigated. Stability studies indicated that the formulations were stable up to relatively stable with respect to size, ZP and drug content for 4 months at the tested conditions. This study demonstrates that the developed PD-conjugated nanoliposomal formulations can effectively serve as a transdermal delivery strategy for ASP.


Asunto(s)
Ingeniería Química/métodos , Dendrímeros/química , Sistemas de Liberación de Medicamentos/métodos , Desarrollo de Medicamentos/métodos , Nanopartículas/química , Fragmentos de Péptidos/química , Administración Cutánea , Animales , Dendrímeros/administración & dosificación , Dendrímeros/toxicidad , Dibenzocicloheptenos/administración & dosificación , Dibenzocicloheptenos/química , Dibenzocicloheptenos/toxicidad , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Liposomas , Masculino , Nanopartículas/administración & dosificación , Nanopartículas/toxicidad , Técnicas de Cultivo de Órganos , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/toxicidad , Ratas , Ratas Sprague-Dawley
15.
J Nutr Biochem ; 86: 108492, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32920088

RESUMEN

The role of the gut microbiome in bone health has received significant attention in the past decade. We investigated the effects of green tea polyphenols (GTP) and annatto-extracted tocotrienols (AT) on bone properties and gut microbiome in obese mice. Male mice were assigned to a two (no AT vs. 400 mg/kg diet AT) × two (no GTP vs. 0.5% w/v GTP) factorial design, namely control, G, T, and G+T group respectively, for 14 weeks. The 4th lumbar vertebra (LV-4) and femur were harvested for bone microstructural analysis using µ-CT. Microbiome analysis using 16S rRNA gene sequencing of cecal feces was performed. AT increased bone volume at distal femur. GTP increased serum procollagen type 1 N-terminal propeptide concentration, bone volume at the distal femur and the LV-4, and trabecular number at distal femur; whereas GTP decreased trabecular separation at distal femur. Interactions between GTP and AT were observed in serum C-terminal telopeptide of type I collagen level (control>G=T=G+T) as well as the cortical bone area (control

Asunto(s)
Bixaceae/química , Huesos/efectos de los fármacos , Carotenoides/química , Microbiota/efectos de los fármacos , Extractos Vegetales/química , Polifenoles/farmacología , , Tocotrienoles/farmacología , Vitamina K 2/metabolismo , Animales , Peso Corporal , Huesos/patología , Clostridiales , Colágeno Tipo I/metabolismo , ADN/metabolismo , Fémur/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Fragmentos de Péptidos/química , ARN Ribosómico 16S/metabolismo , Microtomografía por Rayos X
16.
Eur J Pharm Biopharm ; 155: 177-189, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32828948

RESUMEN

Ultra-small nanostructured lipid carriers (usNLCs) have been hypothesized to promote site-specific glioblastoma (GB) drug delivery. Envisioning a multitarget purpose towards tumor cells and microenvironment, a surface-bioconjugated usNLC prototype is herein presented. The comeback of co-delivery by repurposing atorvastatin and curcumin, as complementary therapy, was unveiled and characterized, considering colloidal properties, stability, and drug release behavior. Specifically, the impact of the surface modification of usNLCs with hyaluronic acid (HA) conjugates bearing the cRGDfK and H7k(R2)2 peptides, and folic acid (FA) on GB cells was sequentially evaluated, in terms of cytotoxicity, internalization, uptake mechanism and hemolytic character. As proof-of-principle, the biodistribution, tolerability, and efficacy of the nanocarriers were assessed, the latter in GB-bearing mice through magnetic resonance imaging and spectroscopy. The hierarchical modification of the usNLCs promotes a preferential targeting behavior to the brain, while simultaneously sparing the elimination by clearance organs. Moreover, usNLCs were found to be well tolerated by mice and able to impair tumor growth in an orthotopic xenograft model, whereas for mice administered with the non-encapsulated therapeutic compounds, tumor growth exceeded 181% in the same period. Relevant biomarkers extracted from metabolic spectroscopy were ultimately identified as a potential tumor signature.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Inhibidores de Crecimiento/administración & dosificación , Nanoestructuras/administración & dosificación , Fragmentos de Péptidos/administración & dosificación , Microambiente Tumoral/efectos de los fármacos , Animales , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Inhibidores de Crecimiento/química , Humanos , Ácido Hialurónico/administración & dosificación , Ácido Hialurónico/química , Masculino , Ratones , Ratones Desnudos , Nanoestructuras/química , Fragmentos de Péptidos/química , Células THP-1 , Microambiente Tumoral/fisiología , Ensayos Antitumor por Modelo de Xenoinjerto/métodos
17.
J Vis Exp ; (160)2020 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-32597857

RESUMEN

Natural products derived from plants and microbes are a rich source of bioactive molecules. Prior to their use, the active molecules from complex extracts must be purified for downstream applications. There are various chromatographic methods available for this purpose yet not all labs can afford high performance methods and isolation from complex biological samples can be difficult. Here we demonstrate that preparative liquid-phase isoelectric focusing (IEF) can separate molecules, including small molecules and peptides from complex plant extracts, based on their isoelectric points (pI). We have used the method for complex biological sample fractionation and characterization. As a proof of concept, we fractionated a Gymnema sylvestre plant extract, isolating a family of terpenoid saponin small molecules and a peptide. We also demonstrated effective microbial protein separation using the Candida albicans fungus as a model system.


Asunto(s)
Productos Biológicos/aislamiento & purificación , Candida albicans/metabolismo , Proteínas Fúngicas/aislamiento & purificación , Focalización Isoeléctrica/métodos , Fragmentos de Péptidos/aislamiento & purificación , Extractos Vegetales/química , Bibliotecas de Moléculas Pequeñas/aislamiento & purificación , Productos Biológicos/química , Proteínas Fúngicas/química , Gymnema sylvestre/química , Fragmentos de Péptidos/química , Bibliotecas de Moléculas Pequeñas/química
18.
Eur J Med Chem ; 198: 112257, 2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32375073

RESUMEN

In our overall goal to overcome the limitations associated with natural products for the management of Alzheimer's disease and to develop in-vivo active multifunctional cholinergic inhibitors, we embarked on the development of ferulic acid analogs. A systematic SAR study to improve upon the cholinesterase inhibition of ferulic acid with analogs that also had lower logP was carried out. Enzyme inhibition and kinetic studies identified compound 7a as a lead molecule with preferential acetylcholinesterase inhibition (AChE IC50 = 5.74 ± 0.13 µM; BChE IC50 = 14.05 ± 0.10 µM) compared to the parent molecule ferulic acid (% inhibition of AChE and BChE at 20 µM, 15.19 ± 0.59 and 19.73 ± 0.91, respectively). Molecular docking and dynamics studies revealed that 7a fits well into the active sites of AChE and BChE, forming stable and strong interactions with key residues Asp74, Trp286, and Tyr337 in AChE and with Tyr128, Trp231, Leu286, Ala328, Phe329, and Tyr341 in BChE. Compound 7a was found to be an efficacious antioxidant in a DPPH assay (IC50 = 57.35 ± 0.27 µM), and it also was able to chelate iron. Data from atomic force microscopy images demonstrated that 7a was able to modulate aggregation of amyloid ß1-42. Upon oral administration, 7a exhibited promising in-vivo activity in the scopolamine-induced AD animal model and was able to improve spatial memory in cognitive deficit mice in the Y-maze model. Analog 7a could effectively reverse the increased levels of AChE and BChE in scopolamine-treated animals and exhibited potent ex-vivo antioxidant properties. These findings suggest that 7a can act as a lead molecule for the development of naturally-inspired multifunctional molecules for the management of Alzheimer's and other neurodegenerative disorders.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Productos Biológicos/química , Colinérgicos/química , Inhibidores de la Colinesterasa/química , Colinesterasas/metabolismo , Ácidos Cumáricos/química , Secuencia de Aminoácidos , Péptidos beta-Amiloides/metabolismo , Animales , Antioxidantes/química , Antioxidantes/farmacología , Productos Biológicos/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Colinérgicos/farmacología , Inhibidores de la Colinesterasa/farmacología , Disfunción Cognitiva/tratamiento farmacológico , Ácidos Cumáricos/farmacología , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Humanos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Modelos Moleculares , Fragmentos de Péptidos/química , Escopolamina/metabolismo , Memoria Espacial/efectos de los fármacos
19.
Int J Pharm ; 582: 119310, 2020 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-32276088

RESUMEN

Antigen-adjuvant combination could induce a protective and long-lasting anti-tumor immune response. However, exploiting system which could co-deliver melanoma antigen peptide Trp2 (Tyrosinase-related protein 2) and Toll-like-receptor-7 (TLR7) agonists imiquimod (R837) both are poor aqueous solubility is still challenging. Our new nanocomplex was explored for specific delivery of Trp2 and R837 into antigen-presenting cells (APCs). R837 was loaded into mannosylated-ß-cyclodextrin (Man-CD) to target dendritic cells (DCs) by binding mannose receptors (MR) on DCs. A fusion peptide (WT) was constructed by incorporating the amino acid region of TAT (cell-penetrating peptide) into Trp2 to improve the TAT-mediated intracellular efficiency. Negatively charged sodium alginate (SA), a biocompatible polymer, which can induce adjuvant responses by affecting the functions of DCs, was complexed with Man-CD/R837 and WT via physical adsorption. The optimized nanocomplex promoted the cellular uptake and showed remarkable efficacy to enhance the secreting of Th1-cytokines. This multi-functional nanocomplex system may allow effective targeting-codelivery of multi-hydrophobic drugs and be a promising subunit vaccine candidate as a potential prevention action of tumor.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Vacunas contra el Cáncer/farmacología , Portadores de Fármacos , Imiquimod/farmacología , Manosa/química , Melanoma Experimental/tratamiento farmacológico , Proteínas de la Membrana/farmacología , Nanopartículas , Fragmentos de Péptidos/farmacología , beta-Ciclodextrinas/química , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/química , Alginatos/química , Alginatos/farmacología , Animales , Vacunas contra el Cáncer/administración & dosificación , Vacunas contra el Cáncer/química , Línea Celular Tumoral , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Composición de Medicamentos , Femenino , Interacciones Hidrofóbicas e Hidrofílicas , Imiquimod/administración & dosificación , Imiquimod/química , Lectinas Tipo C/metabolismo , Receptor de Manosa , Lectinas de Unión a Manosa/metabolismo , Melanoma Experimental/inmunología , Melanoma Experimental/metabolismo , Proteínas de la Membrana/administración & dosificación , Proteínas de la Membrana/química , Ratones Endogámicos C57BL , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/química , Receptores de Superficie Celular/metabolismo , Solubilidad , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Linfocitos T Colaboradores-Inductores/metabolismo
20.
Curr Pharm Des ; 26(12): 1365-1376, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31931693

RESUMEN

The ß-amyloid peptide (1-42) is a molecule capable of aggregating into neurotoxic structures that have been implicated as potential etiological factors of Alzheimer's Disease. The aim of this study was to evaluate the inhibition of ß-amyloid aggregation of ethyl acetate and ethanolic extracts obtained from Ugni molinae leaves on neurotoxic actions of ß-amyloid aggregates. Chemical analyses were carried out with the extracts in order to determine their phenolic profile and its quantification. Both extracts showed a tendency to reduce neuronal deaths caused by ß-amyloid. This tendency was inversely proportional to the evaluated concentrations. Moreover, the effect of EAE and ETE on ß-amyloid aggregation was studied by fluorimetric T Thioflavin assay and transmission electronic microscopy (TEM); the extracts showed a modulation in the aggregation process. Partly, it is believed that these effects can be attributed to the polyphenolic compounds present in the extracts.


Asunto(s)
Enfermedad de Alzheimer , Myrtaceae , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/metabolismo , Humanos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Fenoles/química , Extractos Vegetales/farmacología , Hojas de la Planta/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA