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1.
Pak J Pharm Sci ; 33(5): 2113-2120, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33824120

RESUMEN

The major polyphenol (-)-epigallocatechin gallate (EGCG) of green tea shows well-known health benefits such as potential anti-cancer, anti-oxidation and ameliorating cardiovascular disease. This work aims to improve the bioactivity of EGCG on H9C2 cardiomyocytes by combination regimen of vardenafil and EGCG. The proliferative rates were significantly improved by 18.74%, 10.77% and 29.17% after 48 h with EGCG, vardenafil, and the combination of EGCG and low-dose vardenafil treatments, respectively. The treatments also increased the expression of the nitric oxide synthase (eNOS), and acutely stimulate production of vasodilators nitric oxide (NO) from 17.33µmol/L to 19.75, 20.87 and 24.47µmol/L in H9C2 cells. We further demonstrated that vardenafil also remarkably promoted EGCG to counteract H2O2-induced apoptotic damage in H9C2 by strengthening antioxidant defense systems and suppressing myocardial apoptosis. These results suggest that EGCG and low-dose vardenafil in combination may be a promising regimen to help prevent cardiovascular diseases.


Asunto(s)
Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Catequina/análogos & derivados , Proliferación Celular/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Diclorhidrato de Vardenafil/farmacología , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Catequina/farmacología , Línea Celular , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Peróxido de Hidrógeno/toxicidad , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Ratas , Transducción de Señal
2.
Molecules ; 24(2)2019 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-30642065

RESUMEN

Castanopsis lamontii is traditionally used to prevent inflammatory diseases such as periodontitis and pharyngitis by residents in southwest China. However, little scientific evidence has been found to support this. In this research, the antibacterial activities of Castanopsis lamontii water extract (CLE) were assessed using the micro-dilution method. The anti-inflammatory and antioxidant activities of CLE were investigated in RAW264.7 cells. Key bioactive compounds in CLE were also explored. Results showed that CLE was capable of inhibiting the periodontitis pathogen Porphyromonas gingivalis and the pharyngitis pathogen ß-hemolytic Streptococcus. It suppressed lipopolysaccharide-induced inflammation in RAW 264.7 cells via inactivating the TLR4/NF-κB pathway. Besides, it reduced oxidative stress-induced cell injury via scavenging reactive oxygen species. Chemical composition analysis revealed that CLE was rich in epicatechin and procyanidin B2. Further studies confirmed that epicatechin predominantly contributed to the antibacterial activities of CLE, while procyanidin B2 was mainly responsible for the anti-inflammatory activities of CLE. Both compounds contributed to the antioxidant activities of CLE. Acute oral toxicity tests proved that CLE was practically non-toxic. These results provide experimental evidences of the health-beneficial effects of CLE and may help promote the application of CLE in the food and health industries.


Asunto(s)
Fagaceae/química , Inflamación/etiología , Inflamación/metabolismo , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Antibacterianos/farmacología , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Bacterias/efectos de los fármacos , Femenino , Inflamación/patología , Masculino , Ratones , Pruebas de Sensibilidad Microbiana , Fitoquímicos/química , Fitoquímicos/farmacología , Extractos Vegetales/química , Células RAW 264.7 , Especies Reactivas de Oxígeno/metabolismo
3.
Planta Med ; 83(17): 1361-1367, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28499304

RESUMEN

Nine new and eleven known phorbol esters were isolated from an acetone extract of the seeds of Croton tiglium. Their structures were determined by extensive analysis of spectroscopic data. Eleven of these compounds were evaluated for their inhibition activity on human tumor cell lines HL-60 and lung carcinoma A549. 12-O-Tiglylphorbol-13-acetate (11), 12-O-(2-methyl)-butyrylphorbol-13-aetate (12), and 12-O-tiglylphorbol-13-isobutyrate (13) exhibited strong inhibition activity against both HL-60 and A549 cell lines with IC50 values ≤ 0.02 and ≤ 0.1 µg/mL, respectively. Compound 18 showed strong inhibition activity against the HL-60 cell line with an IC50 value of 0.02 µg/mL.


Asunto(s)
Croton/química , Ésteres del Forbol/química , Ésteres del Forbol/aislamiento & purificación , Extractos Vegetales/química , Células A549 , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Humanos , Estructura Molecular , Ésteres del Forbol/farmacología , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Semillas/química
4.
J Food Sci Technol ; 54(12): 3908-3916, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29085133

RESUMEN

Fresh tea leaves were crushed into juice and then fermented (oxidation) to obtain fermented black tea juice, which can be used to prepare black tea beverage. The effects of addition of oolong tea infusion or tossing of tea leaves on the sensory quality and theaflavins (TFs) concentration of fermented black tea juice were investigated. The results showed that both addition of tea infusion and tossing of fresh tea leaves increased the TFs/thearubigins (TRs) ratio and improved the sensory quality of fermented black tea juice. The TFs/TRs ratio was found to be significantly correlated with the scores for flavor (r = 0.98), mouth feel (r = 0.94), and overall acceptability (r = 0.91) of the fermented black tea juices from different processes. This result suggested that a relatively high concentration of catechins and stepwise enzymatic oxidation were the crucial factors that increased the TFs/TRs ratio and improved the sensory quality. The combination of adding tea infusion and tossing fresh tea leaves greatly improved the quality of the fermented black tea juice by markedly increasing the TFs/TRs ratio (87%). Results of the present study provided useful information for improving the quality of fermented black tea juice.

5.
Pak J Pharm Sci ; 28(6 Suppl): 2267-72, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26687755

RESUMEN

The Chinese commonly believe that tea helps maintain clear vision. This viewpoint has been recorded in Chinese medical books also. The key bioactive compounds in green tea leaves, (-)-epigallocatechin gallate (EGCG), L-theanine (theanine) and caffeine, were investigated for their abilities to attenuate the injury of retinal ganglion cells (RGC-5) induced by H2O2 and ultraviolet radiation. Theanine and caffeine promoted cell growth while concentrations of EGCG greater than 10µg/ml inhibited cell growth. The nine and caffeine both protected RGC-5 cells from injury as well as enhanced their recovery, while EGCG only protected the cells from injury and did not help them to recover. Tea is a unique drink, which is simultaneously enriched with EGCG, theanine and caffeine. The role of these compounds in optic nerve protection may partially explain why some tea drinkers feel enhanced vision.

6.
Int J Biol Macromol ; 260(Pt 1): 129347, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38224808

RESUMEN

Herein, the low-molecular-weight heteropolysaccharide (designated as TABP), with a weight-average Mw of 5408 Da, was produced by the endophytic bacterium Bacillus sp. TAB, which was initially isolated from the fruiting bodies of the wild Tremella aurantialba. A relatively high TABP accumulation was obtained and enhanced to 6.94 g/L in 5 L fed-batch fermentation by high-density cultivation. Monosaccharide composition analysis showed that the TABP comprised arabinose, glucosamine, galactose, glucose, and mannose with a molar ratio of 0.073: 0.145: 0.406: 0.182: 0.195, respectively. Methylation and NMR analyses indicated that TABP contained 1,4-linked ß-d-Galp and 1,4-linked ß-d-Manp pyranosyl backbone, extensively substituted at the side chains to form a complex structure. Prebiotic potential analysis exhibited significant growth-promoting effects for various lactic acid bacteria by more than 90 %. Overall, this study initially provides valuable insights into the endophytic exopolysaccharides from T. aurantialba and their biological activity, which provides prospective sources of prebiotics for functional foods and aids in understanding the endophytes symbiosis mechanism in edible mushrooms.


Asunto(s)
Basidiomycota , Polisacáridos , Estudios Prospectivos , Polisacáridos/farmacología , Polisacáridos/química , Basidiomycota/química , Bacterias
7.
Food Chem ; 438: 138051, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38056097

RESUMEN

To improve the quality of osmanthus black tea, samples produced with different scenting methods were prepared. The sensory quality was assessed and the characteristic aromatic components were explored using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry. According to the results, osmanthus black tea obtained by adding osmanthus scenting in the fermentation process had the strongest floral aroma. The major contributors to the aroma of osmanthus black tea were identified as ß-ionone, dihydro-ß-ionone, benzeneacetaldehyde, citral, geraniol, and linalool by calculating their relative odor activity values. An analysis of the causes revealed that the moisture content of tea dhool significantly affected the adsorption of fresh flower aroma by tea. The experimental results showed that osmanthus black tea produced using tea dhool containing 30% moisture content had the highest content of crucial aroma components, suggesting the tea dhool under this condition had the strongest adsorption capacity for osmanthus aroma.


Asunto(s)
Camellia sinensis , Oleaceae , Compuestos Orgánicos Volátiles , Té/química , Odorantes/análisis , Compuestos Orgánicos Volátiles/análisis , Camellia sinensis/química
8.
Magn Reson Chem ; 51(7): 435-8, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23630063

RESUMEN

Complete and unambiguous (1)H and (13)C NMR chemical shift assignments for all-trans-retinal, 13-cis-retinal, 11-cis-retinal and 9-cis-retinal (1-4) have been established by means of two-dimensional COSY, HSQC, HMBC and NOESY spectroscopic experiments.


Asunto(s)
Espectroscopía de Resonancia Magnética , Retinaldehído/química , Diterpenos , Estructura Molecular
9.
Foods ; 12(11)2023 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-37297416

RESUMEN

This study was aimed to investigate the effect of Guisangyou tea (GSY tea) in improving abnormal lipid metabolism in mice with obesity induced by a high-fat diet (HFD). The results showed that intervention of the water extract of GSY tea (WE) decreased serum levels of lipids, and positively regulated the related antioxidant enzyme activities and the inflammatory factors in the serum and liver. In the liver, the mRNA and protein expression levels of sterol regulatory element-binding proteins-1 (SREBP-1), stearoyl-CoA desaturase-1 (SCD-1), fatty acid synthase (FASN), and acetyl CoA carboxylase (ACC) related to lipid synthesis were downregulated, and the mRNA and protein expression levels of the farnesoid X receptor (FXR) and small heterodimer partner (SHP) related to bile acid production were upregulated. The results demonstrate that GSY tea can improve abnormal lipid metabolism in obese mice by improving the body's antioxidant capacity, regulating the inflammatory state, and reducing the synthesis of lipids and increasing the production of bile acids. GSY tea can be processed and utilized as a safe and effective resource for improving abnormal lipid metabolism.

10.
Cell Mol Immunol ; 20(4): 404-418, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36823235

RESUMEN

Group 2 innate lymphoid cells (ILC2s) are a category of heterogeneous cells that produce the cytokines IL-5 and IL-13, which mediate the type 2 immune response. However, specific drug targets on lung ILC2s have rarely been reported. Previous studies have shown that type 2 cytokines, such as IL-5 and IL-13, are related to depression. Here, we demonstrated the negative correlation between the depression-associated monoamine neurotransmitter serotonin and secretion of the cytokines IL-5 and IL-13 by ILC2s in individuals with depression. Interestingly, serotonin ameliorates papain-induced lung inflammation by suppressing ILC2 activation. Our data showed that the serotonin receptor HTR2A was highly expressed on ILC2s from mouse lungs and human PBMCs. Furthermore, an HTR2A selective agonist (DOI) impaired ILC2 activation and alleviated the type 2 immune response in vivo and in vitro. Mice with ILC2-specific depletion of HTR2A (Il5cre/+·Htr2aflox/flox mice) abolished the DOI-mediated inhibition of ILC2s in a papain-induced mouse model of inflammation. In conclusion, serotonin and DOI could restrict the type 2 lung immune response, indicating a potential treatment strategy for type 2 lung inflammation by targeting HTR2A on ST2+ ILC2s.


Asunto(s)
Inmunidad Innata , Neumonía , Humanos , Animales , Ratones , Papaína , Interleucina-13 , Interleucina-5 , Serotonina , Linfocitos , Neumonía/inducido químicamente , Pulmón , Citocinas , Interleucina-33
11.
Food Funct ; 13(3): 1291-1298, 2022 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-35028655

RESUMEN

(-)-Epigallocatechin gallate (EGCG)-incorporated casein nanoparticles benefit from excellent antioxidant, anti-inflammatory and anti-cancer activities due to their synergistic efficiency, but few studies have evaluated their safety. In this study, the EGCG-casein nanoparticles (EGCG-NPs) formulated using caseinate by ultrasonic treatment were evaluated for their subacute toxicity. The subacute toxicity test of EGCG-NPs through 28-day oral administration in rats did not exhibit adverse effect, with a no-observed-adverse-effect level (NOAEL) of at least 5.0 g per kg body weight (BW) per day, which was equivalent to 500 mg per kg BW EGCG per day. However, the serum Na level in females and males treated with 10.0 g per kg BW EGCG-NPs increased significantly as compared to the control rats (P < 0.05). Similar indications appeared in rats treated with 10.0 g per kg BW pure casein nanoparticles without EGCG, which indicated that high doses of caseinate nanoparticles result in an excess serum Na level. Therefore, we should consider the safety of the nanoparticle formulation of caseinate when it is used as a loading nutrient and a functional substance in foods.


Asunto(s)
Caseínas/sangre , Catequina/análogos & derivados , Nanopartículas/administración & dosificación , Sodio/sangre , Animales , Catequina/sangre , Portadores de Fármacos/administración & dosificación , Modelos Animales , Ratas , Ratas Sprague-Dawley
12.
Nutrients ; 14(19)2022 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-36235540

RESUMEN

This study aims to develop specific-molecular-weight hyaluronic acid oligosaccharides-coated paclitaxel-loaded casein nanoparticles (HA-PT-Cas NPs) via chemical conjugation to increase the stability and antitumor effects. Optimized HA-PT-Cas NPs (HA/casein of 3:1) were obtained with a mean size of 235.3 nm and entrapment efficiency of 93.1%. HA-PT-Cas exhibited satisfactory stability at 4 °C for 12 days and 37 °C for 3 h; paclitaxel was retained at rates of 81.4% and 64.7%, respectively, significantly higher than those of PT-Cas (only 27.8% at 4 °C after 16 h and 20.3% at 37 °C after 3 h). HA-PT-Cas exhibited high efficiency (61.3%) in inhibiting A375 tumor owing to the enhanced stability of HA oligosaccharides barrier, which was comparable with that of 10 µg/mL cis-platinum (64.9%). Mice experiments showed the 74.6% tumor inhibition of HA-PT-Cas by intravenously administration, significantly higher than that of PT-casein (39.8%). Therefore, this work provides an effective carrier for drug delivery via HA oligomers-coated modification.


Asunto(s)
Nanopartículas , Paclitaxel , Animales , Caseínas , Línea Celular Tumoral , Cisplatino , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Ácido Hialurónico , Ratones , Oligosacáridos , Paclitaxel/farmacología
13.
Foods ; 11(16)2022 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-36010542

RESUMEN

Microwave radiation is one of the main heating methods for food processing, especially affecting the color quality of colorful foods. This work presents the effect of microwave radiation on the green color loss of green tea powder (GTP) by the color description (L*, a*, b*, and Ha of green tea powder, L*:whiteness/darkness, a*: redness/greenness, and b*: yellowness/blueness; Ha derived from Hunter a and b could visually describe the color space) of the Hunter color system. First, the L*, a*, and b* were determined from the GTP samples treated with various microwave powers with the change of time to investigate the kinetic of color loss. Then, the L*, a*, and b*and temperature of GTP samples with serious thickness treated with constant microwave power (700 W) for a different time were determined to study the effect of sample thickness on the color loss. Finally, the chemicals that contributed to color change in the GTP samples treated with mild, moderate, and severe radiation were analyzed. The results showed that L*, |a*| (|a*|was the absolute value of a*), b*, and Ha decreased with the power increase in microwave radiation, and their changes conformed to the first-order kinetics. The activation energies (Ea) of different thickness GTP for change of L*, a*, b*, and Ha values could be predicted with the fitting models, and Ea for 20 mm-thick GTP were approximately 1/5, 1/8, 1/8, and 1/13 of those for 4 mm-thick GTP. The color loss was mainly caused by the Mg2+ loss of chlorophylls and the formation of derivates under mild radiation, the degradation of chlorophylls and the formation of theaflavin from catechins under moderate radiation, and the degradation of chlorophylls and their derivates accompanied by Maillard reaction between reducing sugar and amino acids under severe radiation. The results indicate that sample thickness and radiation time are two key parameters to keeping the color of GTP in food processing and microwave pasteurization.

14.
Nutrients ; 14(23)2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36501222

RESUMEN

Curcumin possesses beneficial biological functions, namely anti-inflammation and anti-diabetic functions. However, due to its low solubility and crystallinity, its applications are limited. In this work, curcumin was encapsulated in casein micelles in order to form curcumin-casein nanoparticles by ultrasound treatment (5 min). The ultrasound treatment induced the entry of the hydrophobic groups to the inner micelles and the polar sulfydryl groups to the surface of the micelles in order to form compact curcumin-casein nanoparticles of an appropriate size (100-120 nm) for cellular endocytosis. The product exhibited excellent stability during 8 months of cold storage, 6 days at room temperature, and 2 days at body temperature. Advanced in vitro experiments demonstrated that curcumin-casein nanoparticles displayed significantly greater inhibitory activity against the proliferation and proinflammatory cytokines of human fibroblast-like synoviocyte-osteo arthritis (HFLS-OA) cells and HFLS-rheumatoid (RA) cells than native curcumin due to better cellular uptake as a result of the low crystallinity and the appropriate nano-size of the nano-form. The results provide a reference for the use of ultrasound treatment to encapsulate other drug molecules and curcumin-casein nanoparticles as potential treatment for arthritis.


Asunto(s)
Curcumina , Nanopartículas , Humanos , Curcumina/farmacología , Curcumina/química , Caseínas/farmacología , Caseínas/química , Nanopartículas/química , Micelas , Solubilidad , Tamaño de la Partícula
15.
Bioorg Med Chem Lett ; 21(3): 1001-3, 2011 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-21215628

RESUMEN

Two new tetrasaccharide glyceroglycolipids were obtained from pumpkin. The structures of the two compounds were determined using chemical methods and spectroscopic analysis. Both compounds demonstrated significant glucose-lowering effects in streptozotocin- and high-fat-diet-induced diabetic mice.


Asunto(s)
Cucurbita/química , Glucolípidos/química , Hipoglucemiantes/química , Animales , Glucemia/análisis , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/tratamiento farmacológico , Frutas/química , Glucolípidos/aislamiento & purificación , Glucolípidos/uso terapéutico , Hipoglucemiantes/aislamiento & purificación , Hipoglucemiantes/uso terapéutico , Espectroscopía de Resonancia Magnética , Ratones , Conformación Molecular
16.
J Asian Nat Prod Res ; 13(3): 260-4, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21409689

RESUMEN

A new abietane diterpenoid, (3S,16R)-12,16-epoxy-3,6,11,14,17-pentahydroxy-17(15 â†’ 16)-abeo-5,8,11,13-abietatetraen-7-one (1), was isolated from the stems of Clerodendrum kaichianum Hsu, together with four known diterpenoids. The structures of the isolated compounds were assigned on the basis of their NMR spectra including 2D NMR techniques such as COSY, HMQC, and HMBC experiments, and were compared with those of the literature data. This new compound showed significant cytotoxicity against the HL-60 and A-549 tumor cell lines.


Asunto(s)
Abietanos/química , Abietanos/aislamiento & purificación , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Clerodendrum/química , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/aislamiento & purificación , Abietanos/farmacología , Antineoplásicos Fitogénicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Medicamentos Herbarios Chinos/farmacología , Células HL-60 , Humanos , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular
17.
Zhongguo Zhong Yao Za Zhi ; 36(17): 2361-6, 2011 Sep.
Artículo en Zh | MEDLINE | ID: mdl-22121804

RESUMEN

A UPLC-ESIMS method was developed for simultaneous analysis of seven major bioactive flavonolignans in silymarin including silychristins A(1) and B(2), silydianin(3), silybins A(4) and B(5), and isosilybins A(6) and B(7). In this study, the seven major active flavonolignans including the diastereomers 1/2, 4/5, and 6/7 were completely separated using UPLC with an ACQUITY UPLC C18 column and MeOH-water (formic acid) mobile phase system. The collision-induced dissociation (CID) MS/MS spectra of these flavonolignans were studied systematically using ESI-MS. The results with the present methodology showed that UPLC-MS/MS can be used for general screening of active natural products from plant extracts and for the specific quality control of silymarin.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Extractos Vegetales/química , Silimarina/química , Espectrometría de Masa por Ionización de Electrospray/métodos , Estructura Molecular
18.
RSC Adv ; 11(8): 4646-4653, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-35424385

RESUMEN

The aim of this study was to improve the stability of eugenol-casein nanoparticles (EL-CS-NPs) through polyethylene glycol (PEG) modification. The results show that modifying the EL-CS-NPs with PEG after loading with eugenol (EL) gives PEG-EL-CS-NPs, with increased stability. The NPs modified with higher-molecular-weight PEG showed better stability. A CS/PEG ratio of 200 : 1 (w/w) yielded the NPs with the best stability. A PEG20 K-EL-CS-NP dispersion remained stable in cold storage for over one year, and also exhibited stronger inhibitory effects against Colletotrichum musae inoculated on bananas than an EL-CS-NP dispersion, since it showed more prolonged sustained release of EL than the EL-CS-NP dispersion. Lyophilized PEG20 K-EL-CS-NP powder showed better effectiveness against mold on bread than lyophilized EL-CS-NPs powder. Using PEG to modify CS-NPs shows potential for improving the stability of CS-NPs loaded with hydrophobic substances for delivery in the fields of food and agriculture.

19.
Food Chem ; 360: 130036, 2021 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-34004594

RESUMEN

This study aimed to investigate the antibacterial efficiency and synergistic mechanisms of novel formulated eugenol-casein-lysozyme nanoparticles (ECL-NPs) against gram-positive bacteria. We obtained optimized ECL-NPs 151.9 nm in size and with an entrapment efficiency of 92.2%. ECL-NPs exhibited a satisfactory slow-release pattern, excellent storage stability (for 180 days at 4 °C), and freeze-drying stability. The synergy of low-dose lysozyme significantly enhanced the inhibitory efficiency of eugenol-casein nanoparticles against Staphylococcus aureus and Bacillus sp. by 5.83-fold and 5.53-fold, respectively; this resulted in a much lower minimum inhibitory concentration (3.75-fold and 4.16-fold) and minimum bacterial concentration (2.92-fold and 1.70-fold) values. Scanning electron microscopy clearly demonstrated that the entire cell morphological structure was broken into pieces after exposure to ECL-NPs. Furthermore, 100% microbial inhibition was observed in fresh fruits treated with ECL-NPs for 15 days. These findings suggest that ECL-NPs have an excellent potential for use in food industry against gram-positive bacteria.


Asunto(s)
Antibacterianos/farmacología , Caseínas/química , Eugenol/química , Bacterias Grampositivas/efectos de los fármacos , Muramidasa/química , Antiinfecciosos , Bacillus/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Nanopartículas/química , Staphylococcus aureus/efectos de los fármacos
20.
Carbohydr Polym ; 251: 117115, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33142650

RESUMEN

Mannans are functional polysaccharides with unique biological activities that have been employed widely in food, medicine and pharmaceutics. Recent breakthroughs in plant polysaccharide metabolism identified numerous genes involved in the biosynthesis of mannans. However, constructing highly efficient low-cost microbial cell factories to produce low-molecular-weight (LMW) mannans remains challenging. In this work, we designed a de novo mannan synthetic pathway in food-grade Bacillus subtilis, resulting in mannan accumulation of 0.97 g/L. By co-expressing the identified committed genes (manC, manB, manA and pgi), mannan production was significantly increased to 2.5 g/L. Furthermore, by redirecting the carbon flux using a glucose-repressed promoter to control pfkA expression, mannan production was substantially increased to 4.1 g/L. Production was further enhanced to 12.6 g/L (average MW 6370 Da) in 3-L fed-batch fermentation. This work provides alternative synthetic pathways for metabolic engineering of LMW mannans in B. subtilis, and a useful, optimisable approach to enhance mannans production.


Asunto(s)
Bacillus subtilis/metabolismo , Glucosa/metabolismo , Mananos/biosíntesis , Ingeniería Metabólica/métodos , Bacillus subtilis/genética , Proteínas Bacterianas/metabolismo , Fermentación , Mananos/aislamiento & purificación , Peso Molecular
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