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1.
Food Funct ; 15(4): 1938-1947, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38269604

RESUMEN

This study evaluates the functional characteristics of the exopolysaccharide (EPS) extracts produced by various strains of Lactiplantibacillus pentosus (LPG1, 119, 13B4, and Lp13) and Lactiplantibacillus plantarum (Lp15) isolated from table olives. None of the EPS crude extracts showed cytotoxicity when administered to THP-1 human macrophage cells at dosages ranging from 6.25 to 50 µg mL-1. Many exhibited anti-inflammatory properties (reduction of pro-inflammatory cytokines TNF-α and IL-6 production) and antioxidant activity (reduction of ROS%) when macrophages were stimulated with Escherichia coli lipopolysaccharide. Notably, the EPS extract produced by the L. pentosus LPG1 strain had the best results corroborated by western blot immune analysis for differential expression of COX-2, Nrf-2, and HO-1 proteins, with the most significant antioxidant and anti-inflammatory response observed at a dosage of 50 µg mL-1. Chemical analysis revealed that the EPS extract produced by this strain contains a heteropolymer composed of mannose (35.45%), glucose (32.99%), arabinose (17.93%), xylose (7.48%), galactose (4.03%), rhamnose (1.34%), and fucose (0.77%). Finally, we conducted response surface methodology to model the EPS extract production by L. pentosus LPG1 considering pH (3.48-8.52), temperature (16.59-33.41 °C) and salt concentration (0.03-8.77% NaCl) as independent variables. The model identified linear effects of salt and pH and quadratic effects of salt as significant terms. The maximum EPS extract production (566 mg L-1) in a synthetic culture medium (MRS) was achieved at pH 7.5, salt 7.0%, and a temperature of 20 °C. These findings suggest the potential for novel applications for the EPS produced by L. pentosus LPG1 as nutraceutical candidates for use in human diets.


Asunto(s)
Olea , Polisacáridos Bacterianos , Humanos , Polisacáridos Bacterianos/química , Suplementos Dietéticos , Medios de Cultivo , Antioxidantes/farmacología , Antioxidantes/química , Antiinflamatorios
2.
Sci Rep ; 13(1): 21871, 2023 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-38072846

RESUMEN

Bacterial exopolysaccharides are homopolymeric or heteropolymeric polysaccharides with large molecular weights (10-1000 kDa). Exopolysaccharides' functional uses and potential have revolutionized the industrial and medicinal industries. Hence, the aim of the present study was to optimize the production of bacterial exopolysaccharide and apply it as a capping agent for selenium nanoparticles synthesis. Exopolysaccharide (EPS) producing Lactic acid bacteria (LAB) were isolated from dairy products then biochemically characterized and assessed for their potential antimicrobial effect. The most potent EPS producer was identified as Lactiplantibacillus plantarum strain A2 with accession number OP218384 using 16S rRNA sequencing. Overall, FTIR data of the extracted EPS revealed similarity with amylopectin spectrum. 1H NMR spectrum revealed an α-anomeric configuration of the glycosidic linkage pattern in the polysaccharides while the 13C NMR spectrum can also be separated into two main portions, the anomeric carbons region (δ 98-102 ppm) and the non-anomeric carbons region (δ 60-81 ppm). Antimicrobial activity of the produced EPS showed maximum activity against Staphylococcus aureus, MRSA, Enterobacter aerogenes, Klebsiella pneumoniae and Candida albicans respectively. The EPS capsule layer surrounding the bacterial cells was detected by TEM study. Optimization of EPS production was evaluated using Taguchi design, trial 23 reported the highest biomass yield and EPS output (6.5 and 27.12 g/L respectively) with 2.4 and 3.3 folds increase (from the basal media) respectively. The optimized exopolysaccharide was used as a capping and stabilizing agent for selenium nanoparticles (EPS-SeNPs) synthesis. Zeta potential, size and PDI of the synthesized nanoparticles were - 19.7 mV, 45-65 nm and 0.446 respectively with strong bactericidal and fungicidal effect against the tested pathogens. Complete microbial growth eradication was recorded after 6, 8 and 10 h against Staphylococcus aureus, Candida albicans and Klebsiella pneumoniae respectively. EPS-SeNPs showed a potent antioxidant effect reached 97.4% and anticancer effect against A549 lung cancer cell line (IC50 reached 5.324 µg/mL). EPS-SeNPs inhibited cancerous cell growth at S phase. Moreover, molecular studies revealed the anti-apoptotic activity of Bcl2's was inhibited and Bax was activated. The present investigation successfully synthesized selenium nanoparticles through bacterial EPS with significantly high antimicrobial and anticancer activity.


Asunto(s)
Antiinfecciosos , Neoplasias Pulmonares , Nanopartículas , Selenio , Humanos , Selenio/farmacología , Selenio/química , ARN Ribosómico 16S/genética , Polisacáridos Bacterianos/química , Antiinfecciosos/farmacología , Antiinfecciosos/metabolismo , Nanopartículas/química , Staphylococcus aureus/genética , Candida albicans , Bacterias/genética
3.
Int J Biol Macromol ; 243: 125092, 2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37247706

RESUMEN

Scientists from across the world are being inspired by recent development in polysaccharides and their use in medical administration. Due to their extraordinary physical, chemical, and biological characteristics, polysaccharides are excellent materials for use in medicine. Acidic polysaccharides, which include Pectin, Xanthan gum, Carrageenan, Alginate, and Glycosaminoglycan, are natural polymers with carboxyl groups that are being researched for their potential as drug delivery systems. Most publications do not discuss how the different polysaccharides interact structurally in terms of drug delivery, which limits the scope of their use. The purpose of this review is to inform readers about the structural activity correlations between acidic polysaccharides, their different modification process and effects of combination of various acidic polysaccharides which have been used in drug delivery systems and expanding their potential applications, and bringing new perspectives to the fore.


Asunto(s)
Polisacáridos Bacterianos , Polisacáridos , Polisacáridos/química , Polisacáridos Bacterianos/química , Sistemas de Liberación de Medicamentos , Alginatos/química , Carragenina , Pectinas , Polímeros/química
4.
Food Chem ; 403: 134320, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36162267

RESUMEN

A novel film composed of Polygonatum cyrtonema extracts (PCE), xanthan gum (XG), flaxseed gum (FG) and carboxymethyl cellulose (CMC) was prepared (XFCP). Addition of PCE has decreased the light transmittance, while enhanced the UV blocking performance, antioxidant activity, tensile strength and elongation at break of XFCP due to polysaccharides, polyphenols, and flavonoid in PCE. Structural analyses by FTIR and XRD indicated the hydrogen-bonding interaction between PCE, XG, FG and CMC. It was found that compared with the control sample, XFCP2.5% with the lowest WVTR was able to prolong the shelf life of mango. The overall quality of mango was also improved in terms of lower decay rate, weight loss rate, total soluble solid, and polyphenol oxidase, higher titratable acidity, Vc, and superoxide dismutase than control mango upon 8 days of storage. This effectively expanded the application of PCE into food packaging in addition to merely as Chinese traditional medicine herbs.


Asunto(s)
Lino , Mangifera , Polygonatum , Carboximetilcelulosa de Sodio/química , Antioxidantes/química , Polisacáridos Bacterianos/química , Embalaje de Alimentos , Extractos Vegetales
5.
Molecules ; 27(2)2022 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35056840

RESUMEN

The aim of the study was to evaluate emulsion systems prepared on the basis of blended fat in different ratios (watermelon seed oil and mutton tallow) stabilised by orange fibres and xanthan gum. Emulsions were subjected to stability testing by Turbiscan and were assessed in terms of mean droplet size, colour, viscosity, texture, skin hydration and sensory properties. The most stable systems were found to be the ones containing a predominance of mutton tallow in a fat phase. For these emulsions the lowest increase in mean particle size during storage was observed. The study also confirmed the synergistic effect of the thickeners used. The presented emulsions despite favourable physicochemical parameters, did not gain acceptance in sensory evaluation.


Asunto(s)
Citrullus/química , Citrus sinensis/química , Emulsiones , Grasas/química , Aceites de Plantas/química , Polisacáridos Bacterianos/química , Reología , Agua
6.
J Sci Food Agric ; 102(3): 1056-1065, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34312850

RESUMEN

BACKGROUND: Foam-gels are one of the most important multicomponent-model systems in aerated confectionery, and an investigation of their microstructure is desirable. In this research, the structure-function relationship of xanthan gum/guar gum (XG/GG) and licorice (Glycyrrhiza glabra) root extract powder (LEP) was investigated in a high-sugar medium. Foam-gel systems were prepared at 4:10% to 8:20% ratios of LEP to biopolymer. RESULTS: The results show that increasing the LEP content reduced both the melting point and enthalpy, probably due to higher overrun and weaker junctions. Boosting the XG/GG ratio led the enhancement of mechanical properties, whereas increasing the LEP concentration weakened all textural parameters, which could be due to the poor structure of the network in the presence of the foaming agent, increased moisture content and overrun. In the whipped mixture samples containing 10 g kg-1 XG/GG, higher foaming capacity was observed. By increasing the level of biopolymers, smaller and more uniform air cells were formed according to a scanning electron microscopical study. At higher concentration of LEP, smaller bubbles and increased porosity were seen, which could be attributed to the availability of surfactant in the interfacial layer. CONCLUSION: Maximum structural strength was achieved at a 4:20 ratio of LEP to XG/GG. In rheological experiments, pseudoplastic behavior was seen in all samples. Generally, this model system can be simulated for other herbal extracts containing natural surfactants such as saponins. Achieving a more detailed understanding of these structures and their interactions could help in formulating novel food products. © 2021 Society of Chemical Industry.


Asunto(s)
Galactanos/química , Glycyrrhiza/química , Mananos/química , Extractos Vegetales/química , Gomas de Plantas/química , Polisacáridos Bacterianos/química , Azúcares/química , Galactanos/aislamiento & purificación , Mananos/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Gomas de Plantas/aislamiento & purificación , Raíces de Plantas/química , Polisacáridos Bacterianos/aislamiento & purificación , Reología , Azúcares/aislamiento & purificación , Tensoactivos/química , Tensoactivos/aislamiento & purificación , Viscosidad
7.
PLoS One ; 16(12): e0261792, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34941972

RESUMEN

A highly stable oil-in-water nanoemulsion for topical applications, containing mangostins extracted from the pericarp of mangosteen (Garcinia mangostana L.), is a promising strategy to protect mangostins as well as to improve penetration of these important antioxidants through the skins. Nanoemulsions consisted of virgin coconut oil as the oil phase, Tween-80 and Span-80 as surfactants, and xanthan gum as the thickening agent, were prepared using the high-energy and low-energy emulsification methods. The nanoemulsions that were stable up to 28 days had oil droplet diameter of 220 nm to 353 nm and zeta potential of -46.9 mV to -63.7 mV. The accelerated stability test showed that the most stable nanoemulsions were those prepared using the low-energy emulsification method with an estimated shelf life of eleven months, composed of 11% oil phase, 17% surfactant, and 72% aqueous phase. The in vitro percutaneous penetration test for the nanoemulsion with added xanthan gum provided high cumulative skin penetration of mangostins of up to 114 µg/cm2. The results of this study indicate that virgin coconut oil-based nanoemulsions containing mangostins, prepared using the low-energy emulsification method, stabilized by xanthan gum and mixed at 40°C can prospectively be used for topical applications.


Asunto(s)
Garcinia mangostana/química , Nanopartículas , Extractos Vegetales , Absorción Cutánea , Administración Tópica , Animales , Emulsiones/química , Emulsiones/farmacocinética , Emulsiones/farmacología , Ratones , Nanopartículas/química , Nanopartículas/uso terapéutico , Extractos Vegetales/química , Extractos Vegetales/farmacocinética , Extractos Vegetales/farmacología , Polisacáridos Bacterianos/química , Polisacáridos Bacterianos/farmacocinética , Polisacáridos Bacterianos/farmacología , Polisorbatos/química , Polisorbatos/farmacocinética , Polisorbatos/farmacología , Tensoactivos/química , Tensoactivos/farmacocinética , Tensoactivos/farmacología
8.
Drug Des Devel Ther ; 15: 3937-3952, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34556975

RESUMEN

BACKGROUND/OBJECTIVE: Periodontitis is a widely spread oral infection and various antibiotics are utilized for its treatment, but high oral doses and development of antibiotic resistance limit their use. This study was aimed at development of natural polymer-based mucoadhesive bilayer films loaded with moxifloxacin hydrochloride (Mox) and clove essential oil (CEO) to potentially combat bacterial infection associated with periodontitis. METHODS: Films were synthesized by double solvent casting technique having an antibiotic in the gellan gum-based primary layer with clove oil in a hydroxyethyl cellulose-based secondary layer. RESULTS: Prepared films were transparent, flexible, and showed high antibacterial response against both gram-positive and gram-negative bacteria. The films showed excellent pharmaceutical attributes in terms of drug content, folding endurance, swelling index, and mucoadhesive strength. Solid state characterization of formulation showed successful incorporation of drug and oil in separate layers of hydrogel structure. An in-vitro release study showed an initial burst release of drug followed by sustained release for up to 48 hours. CONCLUSION: The prepared mucoadhesive bilayer buccal films could be used as a potential therapeutic option for the management of periodontitis.


Asunto(s)
Antibacterianos/farmacología , Aceite de Clavo/farmacología , Moxifloxacino/farmacología , Polisacáridos Bacterianos/química , Adhesividad , Administración Bucal , Antibacterianos/administración & dosificación , Antibacterianos/química , Química Farmacéutica/métodos , Aceite de Clavo/administración & dosificación , Preparaciones de Acción Retardada , Liberación de Fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Moxifloxacino/administración & dosificación , Moxifloxacino/química , Aceites Volátiles/administración & dosificación , Aceites Volátiles/farmacología , Periodontitis/tratamiento farmacológico , Periodontitis/microbiología
9.
Carbohydr Polym ; 270: 118350, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34364598

RESUMEN

In this study, bacterial cellulose was synthesized by Taonella mepensis from traditional Chinese medicinal herb residues hydrolysate. To overcome the inhibitory effect of fermentation environment, in-situ fermentation with gellan gum adding was carried out for the first time. After 10 days' static fermentation, both high-acyl gellan gum and low-acyl gellan gum adding showed certain beneficial effects for bacterial cellulose production that the highest bacterial cellulose yield (0.866 and 0.798 g/L, respectively) was 59% and 47% higher than that (0.543 g/L) without gellan gum adding. Besides, gellan gum based bacterial cellulose showed some better texture characteristics. Gellan gum was loaded in the nano network of bacterial cellulose, and gellan gum adding had some influence on the crystal structure and thermal degradation behaviors of bacterial cellulose but affected little on its functional groups. Overall, this in-situ fermentation technology is attractive for bacterial cellulose production from low-cost but inhibitory substrates.


Asunto(s)
Celulosa/biosíntesis , Polisacáridos Bacterianos/biosíntesis , Rhodospirillaceae/metabolismo , Celulosa/química , China , Fermentación , Hidrólisis , Medicina Tradicional China , Microscopía Electrónica de Rastreo/métodos , Plantas Medicinales/química , Polisacáridos Bacterianos/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos
10.
Int J Biol Macromol ; 185: 959-965, 2021 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-34229017

RESUMEN

Raspberry pomace extracts (RPE) with different concentrations (0.5 g/L, 1.5 g/L and 3 g/L) were incorporated into pectin/sodium alginate/xanthan gum composite film (PAX) to prepare colorimetric raspberry films (PAXR5, PAXR15 and PAXR30). Fourier Transform Infrared and Scanning Electron Microscopy analysis showed RPE had good compatibility with PAX. Compared to PAX, the raspberry films had lower water vapor permeability and water swelling ratio, higher tensile strength, opacity and antioxidant capacity. The films presented a smoother surface and denser structure than PAX. Furthermore, PAXR15 had an excellent discoloration at pH 1-13, especially at pH 5-10, the color changes of PAXR15 from pink-red-brown-blue-dark green distinguished by the naked eyes. Therefore, it has the potential to become a pH-sensitive film used in monitoring protein-rich food freshness.


Asunto(s)
Alginatos/química , Pectinas/química , Polisacáridos Bacterianos/química , Rubus/química , Embalaje de Alimentos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Rastreo , Espectroscopía Infrarroja por Transformada de Fourier , Resistencia a la Tracción
11.
Food Chem ; 362: 130181, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34082291

RESUMEN

The effect of carboxymethyl cellulose (CMC), high-methoxyl pectin (HMP), konjac glucomannan (KGM), and xanthan gum (XG) on the physicochemical, structural properties, and digestibility of rice starch were investigated and compared. The four viscous soluble dietary fibers (VSDFs) increased the viscosity, storage modulus and loss modulus while decreased the pasting temperature and gelatinization enthalpy. Moreover, XG produced the lowest peak viscosity and dynamic modulus compared with the other VSDFs. Furthermore, the degree of short-range ordered structure of starch with KGM increased from 0.8448 to 0.8716; and the relative crystallinity of starch with XG increased by 12%. An ordered and reunited network structure was observed in SEM. In addition, VSDF inhibited the digestibility of rice starch and significantly increased the resistant starch content. This study compared the effect of four VSDFs on the physicochemical, structural and digestion properties of rice starch to fully understand and develop their application to starchy foods.


Asunto(s)
Fibras de la Dieta , Oryza/química , Almidón/química , Almidón/farmacocinética , Rastreo Diferencial de Calorimetría , Carboximetilcelulosa de Sodio/química , Digestión , Mananos/química , Pectinas/química , Polisacáridos Bacterianos/química , Almidón Resistente , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termodinámica , Viscosidad
12.
Int J Biol Macromol ; 183: 2100-2108, 2021 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-34102235

RESUMEN

Effect of edible coatings of gum Arabic, carrageenan and xanthan gum containing lemon grass essential oil 1% w/v on postharvest quality of strawberry was studied under refrigeration for a period of 12 days. Results showed all the three coatings maintained fruit quality parameters during storage compared to control. Among all the coatings, carrageenan coated fruits showed delayed weight loss (10.1 to 8%), decay percentage (78.42 to 14.29%), retained ascorbic acid (0.15 to 0.27 g kg-1), antioxidant activity (18.17 to 25.85%), firmness (9.07 to 12.43 N), L* (32.38 to 40.42), a* (16.08 to 17.22) and b* (27.36 to 33.54). Carrageenan gum also showed lowest cellulase activity (0.03 units h-1 mg protein-1), pectin methylesterase activity (1.13 A620 min-1 mg protein-1) and ß-galactosidase activity (0.51 µmol min-1 mg protein-1), while showed maximum reduction in polygalacturonase activity (0.07 units h-1 mg protein-1) at the end of storage. Carrageenan gum was found effective in retention of anthocyanins and phenolic compounds during storage. Coatings loaded with antimicrobial agent inhibited psychrophilic bacteria, yeast and mold growth. It is concluded that carrageenan gum could better retain strawberry quality up to 12 days under refrigeration.


Asunto(s)
Antiinfecciosos/química , Carragenina/química , Películas Comestibles , Embalaje de Alimentos , Conservación de Alimentos , Fragaria/enzimología , Frutas/enzimología , Goma Arábiga/química , Aceites de Plantas/química , Polisacáridos Bacterianos/química , Antocianinas/metabolismo , Antiinfecciosos/farmacología , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Hidrolasas de Éster Carboxílico/metabolismo , Celulasa/metabolismo , Cymbopogon , Microbiología de Alimentos , Almacenamiento de Alimentos , Fragaria/microbiología , Frutas/microbiología , Fenoles/química , Aceites de Plantas/aislamiento & purificación , Aceites de Plantas/farmacología , Poligalacturonasa/metabolismo , Refrigeración , Factores de Tiempo , beta-Galactosidasa/metabolismo
13.
Food Chem ; 358: 129819, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33933974

RESUMEN

The formation mechanism of furan has been studied extensively in model systems, however, furan formation in real foods are complex and far from being fully understood. In this study, the effects of acid-regulating agent (citric acid), sugar addition (glucose, fructose and sucrose) and thickening agents (xanthan gum, κ-carrageenan and pectin) on furan levels in strawberry jams were studied; meanwhile the formation pathway of furan in canned strawberry jam was proposed by carbon module labeling (CAMOLA) technique. Our results suggested low pH promoted furan formation in strawberry jam. Besides, fructose produces more furans than sucrose and glucose, and the addition of xanthan gum reduced furan levels significantly. The kinetic data showed that ascorbic and dehydroascorbic acid degradation followed first-order kinetics while rate of furan formation followed zero-order kinetics. This study presented the possibility of mitigating furan formation in canned strawberry jams by optimization of processing parameters and addition of xanthan gum.


Asunto(s)
Industria de Procesamiento de Alimentos/métodos , Fragaria/química , Furanos/química , Carragenina/química , Ácido Cítrico/química , Ácido Deshidroascórbico/química , Fructosa/química , Frutas/química , Glucosa/química , Cinética , Pectinas/química , Polisacáridos Bacterianos/química , Sacarosa/química
14.
J Mater Chem B ; 9(14): 3224-3234, 2021 04 14.
Artículo en Inglés | MEDLINE | ID: mdl-33885626

RESUMEN

An injectable gellan gum-based nanocomposite hydrogel (Bi2S3@GG) was designed for X-ray computed tomography (CT) imaging and photothermal/antiangiogenic therapy. The linear anionic polysaccharide gellan gum (GG) was used as a stabilizer, embedded with ultra-small bismuth sulfide (Bi2S3) nanodots (∼2 nm) through a one-pot synthesis method. The as-prepared Bi2S3@GG hydrogel displays excellent capability for both photothermal therapy (PTT) (with a photothermal conversion efficiency of 44.3%) and X-ray computed tomography (with an X-ray absorption coefficient of 51.5 HU L g-1), integrated with real-time monitoring drug retention and tunable therapeutic functions. After the incorporation of sorafenib (SF), the hydrogel shows a sustained release of SF over 15 days. A tumor suppression rate of 98.2% is shown at day 22 postinjection in the mice received the combined treatments of photothermal/antiangiogenic therapy. In contrast, tumor growth and recurrence are observed in the single treatment. Our work presents a new strategy to construct a multifunctional hydrogel platform for a safe and precise antitumor therapy.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antineoplásicos/farmacología , Imagen Óptica , Fototerapia , Inhibidores de la Angiogénesis/síntesis química , Inhibidores de la Angiogénesis/química , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Bismuto/química , Bismuto/farmacología , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Hidrogeles/química , Hidrogeles/farmacología , Masculino , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Polisacáridos Bacterianos/química , Polisacáridos Bacterianos/farmacología , Sulfuros/química , Sulfuros/farmacología , Tomografía Computarizada por Rayos X , Células Tumorales Cultivadas
15.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-33925509

RESUMEN

The structure of the exopolysaccharide capsule of Streptococcus pneumoniae is defined by the genetic arrangement of the capsule operon allowing the unequivocal identification of the pneumococcal serotype. Here, we investigated the environment-dependent composition of the polysaccharide structure of S. pneumoniae serotype 6F. When grown in a chemically defined medium (CDM) with glucose versus galactose, the exopolysaccharide capsule of the serotype 6F strains reveals a ratio of 1/0.6 or 1/0.3 for galactose/glucose in the capsule by 1H-NMR analyses, respectively. Increased production of the capsule precursor UDP-glucose has been identified by 31P-NMR in CDM with glucose. Flow cytometric experiments using monoclonal antibodies showed decreased labelling of Hyp6AG4 (specific for serotype 6A) antibodies when 6F is grown in glucose as compared to galactose, which mirrors the 1H-NMR results. Whole-genome sequencing analyses of serotype 6F isolates suggested that the isolates evolved during two different events from serotype 6A during the time when the 13-valent pneumococcal conjugate vaccine (PCV-13) was introduced. In conclusion, this study shows differences in the capsular structure of serotype 6F strains using glucose as compared to galactose as the carbon source. Therefore, 6F strains may show slightly different polysaccharide composition while colonizing the human nasopharynx (galactose rich) as compared to invasive locations such as the blood (glucose rich).


Asunto(s)
Carbono/metabolismo , Polisacáridos Bacterianos/química , Streptococcus pneumoniae/química , Streptococcus pneumoniae/genética , Anticuerpos Monoclonales/metabolismo , Evolución Biológica , Citometría de Flujo , Galactosa/metabolismo , Genoma Bacteriano , Glucosa/metabolismo , Humanos , Espectroscopía de Resonancia Magnética/métodos , Nasofaringe/microbiología , Fósforo , Filogenia , Infecciones Neumocócicas/microbiología , Serogrupo , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/aislamiento & purificación
16.
Int J Biol Macromol ; 181: 1003-1009, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-33892026

RESUMEN

Due to the convenience, fresh-cut vegetables or fruits as the emerging commercial products have attracted much attention in recent years. However, the preservation of food with high quality remains a big challenge. In this study, one novel kind of edible composite film (PAX) consisted of pectin, sodium alginate (SA), and xanthan gum (XG) was well developed. The optimum concentrations for pectin and SA in PAX film based on the shearing viscosity were 6 g/L and 5 g/L, respectively. Upon this condition, the experimental results from the response surface methodology showed that the tensile strength for the optimized PAX (PAXO) film can reach the maximum value of 29.65 MPa at the concentration of 4 g/L XG, 18 g/L glycerol, and 20 g/L CaCl2. The corresponding elongation at break was 19.02% and the water vapor transmission rate was evaluated to be 18.12 × 10-11 g/(m2·s·pa). Furthermore, the nanocomposites in terms of coating or films were used to keep fresh-cut potatoes, where they exhibited different efficiencies in food preservation with the order: PAXO coating + CaCl2 ≈ PAXO coating > PAXO film > sterile water. All the results indicated that the as-prepared PAXO film or PAXO solution could be good candidates in packaging preservation.


Asunto(s)
Películas Comestibles , Conservación de Alimentos , Nanocompuestos/química , Pectinas/química , Alginatos/química , Embalaje de Alimentos , Frutas/efectos de los fármacos , Glicerol/química , Polisacáridos Bacterianos/química , Vapor , Agua/química
17.
Int J Biol Macromol ; 175: 40-48, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33548306

RESUMEN

Herein, improvement of the stability of the water-in-oil-in-water (W/O/W) emulsions by addition of xanthan gum (XG)/locust bean gum (LBG) mixture in the inner water phase was aimed. The impact of XG/LBG mixture on the physical stability, microstructure and rheological properties of W/O/W emulsions was investigated. It was found that, compared with the control emulsions, the presence of XG/LBG mixture could improve the stability of W/O/W emulsions against coalescence. The tea polyphenols (TPPs) and XG/LBG mixture were simultaneously included in the internal aqueous phase of the double emulsion and stored at 25 and 40 °C in the dark for 28 d. The results showed that XG/LBG mixture not only had a protective role for TPPs encapsulated in the internal water phase, but also maintained more than 50% of the antioxidant capacity of TPPs.


Asunto(s)
Galactanos/química , Mananos/química , Gomas de Plantas/química , Polisacáridos Bacterianos/química , Té/química , Aceite de Coco/química , Emulsiones/química , Polifenoles/química , Reología , Viscosidad , Agua/química
18.
Biomolecules ; 11(2)2021 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-33573343

RESUMEN

Green synthesis of metal nanoparticles using plant extracts as capping and reducing agents for the biomedical applications has received considerable attention. Moreover, emergence and spread of multidrug resistance among bacterial pathogens has become a major health concern and lookout for novel alternative effective drugs has gained momentum. In current study, we synthesized gold nanoparticles using the seed extract of Trachyspermum ammi (TA-AuNPs), assessed its efficacy against drug resistant biofilms of Listeria monocytogenes and Serratia marcescens, and evaluated its anticancer potential against HepG2 cancer cell lines. Microwave-assisted green synthesis of gold nanoparticles was carried out and characterization was done using UV-vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Most nanoparticles were observed as spherical and spheroidal with few anisotropies with an average crystalline size of 16.63 nm. Synthesized TA-AuNPs demonstrated significant biofilm inhibitory activity against L. monocytogenes (73%) as well as S. marcescens (81%). Exopolysaccharide (EPS), motility, and CSH, key elements that facilitate the formation and maintenance of biofilm were also inhibited significantly at the tested sub-minimum inhibitory concentrations (sub-MICs). Further, TA-AuNPs effectively obliterated preformed mature biofilms of S. marcescens and L. monocytogenes by 64% and 58%, respectively. Induction of intracellular ROS production in TA-AuNPs treated bacterial cells could be the plausible mechanism for the reduced biofilm formation in test pathogens. Administration of TA-AuNPs resulted in the arrest of cellular proliferation in a concentration-dependent manner. TA-AuNPs decrease the intracellular GSH in HepG2 cancer cell lines, cells become more prone to ROS generation, hence induce apoptosis. Thus, this work proposes a new eco-friendly and rapid approach for fabricating NPs which can be exploited for multifarious biomedical applications.


Asunto(s)
Antineoplásicos/farmacología , Apiaceae/metabolismo , Oro/química , Nanopartículas del Metal/química , Especies Reactivas de Oxígeno , Semillas/metabolismo , Anisotropía , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Supervivencia Celular , Glutatión Transferasa/metabolismo , Tecnología Química Verde , Células Hep G2 , Humanos , Luz , Peroxidación de Lípido , Listeria monocytogenes/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Transmisión , Microondas , Extractos Vegetales/farmacología , Polisacáridos Bacterianos/química , Dispersión de Radiación , Serratia marcescens/efectos de los fármacos , Sales de Tetrazolio/química , Tiazoles/química , Difracción de Rayos X
19.
Biomolecules ; 11(2)2021 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-33546378

RESUMEN

The study investigated the quality of emulsions containing rabbit fat modified with vegetable oil. The modification of the fat and introducing it as a fatty base into the emulsion was dictated by consumer preferences. Emulsion systems containing various fatty bases and viscosity modifier contents were evaluated in the terms of their stability (by means of Turbiscan test), texture properties, color, and viscosity. Moreover, the emulsions were assessed by a sensory panel in the context of the intensity of the following parameters: color, fragrance, consistency, greasiness, and hydration. The same characteristics were also subject to consumer evaluation. The results of the sensory assessment showed the sensory panel attributed higher scores to consistency and skin hydration to the emulsions formed with modified fats; these systems were more appreciated by consumers as well. The results confirmed a major role of sensory determinations in the development of new emulsion products. They also provide knowledge on modifications to product characteristics that would lead to the best possible quality and consumer acceptance. This research has also reaffirmed that looking for new fats among waste fats is becoming a solution to finding new fatty bases for emulsions. The natural origin of these components, and thus their agreeability with the human body, appear noteworthy as well. Enrichment with unsaturated fatty acids is an added advantage of the enzymatic modification of rabbit fat with pumpkin seed oil and can be applied not only for food but also for skin applications.


Asunto(s)
Emulsiones/química , Lípidos/química , Polisacáridos Bacterianos/química , Animales , Coloides/química , Color , Cucurbita , Ácidos Grasos Insaturados/química , Industria de Alimentos , Ensayo de Materiales , Aceites , Aceites de Plantas , Conejos , Reología , Rhizomucor , Viscosidad
20.
Pharm Res ; 38(2): 347-359, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33469875

RESUMEN

PURPOSE: To formulate a xanthan gum-containing linezolid ophthalmic solution (LZD-XG) as a new antibiotic treatment against ocular bacterial infection. METHODS: LZD-XG was prepared and evaluated for its in vitro/in vivo ocular tolerance, in vitro/in vivo antibacterial activity, and in vivo ocular penetration. RESULTS: The optimized LZD-XG exhibited good in vitro/in vivo eye tolerance. A prolonged ocular surface residence time of LZD-XG was observed after topical instillation, and the ocular permeation was significantly better for LZD-XG than fora linezolid (LZD) ophthalmic solution. The in vitro antimicrobial activity was significantly better with LZD-XG than with LZD. In vivo evaluation also confirmed a strong therapeutic treatment effect of LZD-XG, as it significantly improved the clinical symptoms, ameliorated the damage of Staphylococcus aureus to ocular tissues, lowered the colony forming unit counts in the cornea, and decreased the myeloperoxidase activity in the cornea. CONCLUSION: LZD-XG was deemed a viable ophthalmic solution against ocular bacterial infection due to its excellent in vitro and in vivo characterizations.


Asunto(s)
Portadores de Fármacos/química , Queratitis/tratamiento farmacológico , Linezolid/administración & dosificación , Soluciones Oftálmicas/administración & dosificación , Infecciones Estafilocócicas/tratamiento farmacológico , Administración Oftálmica , Animales , Disponibilidad Biológica , Córnea/efectos de los fármacos , Córnea/metabolismo , Córnea/microbiología , Córnea/patología , Modelos Animales de Enfermedad , Humanos , Queratitis/diagnóstico , Queratitis/microbiología , Queratitis/patología , Linezolid/farmacocinética , Pruebas de Sensibilidad Microbiana , Soluciones Oftálmicas/farmacología , Permeabilidad , Polisacáridos Bacterianos/química , Conejos , Microscopía con Lámpara de Hendidura , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/patología , Staphylococcus aureus/efectos de los fármacos
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