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1.
Food Chem ; 367: 130738, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34384978

RESUMO

A homogeneous galactoglucan was purified from the alkali-extracted polysaccharides from the basidioma of Macrolepiota albuminosa by gradient ethanol precipitation, whose proposed structure was given for the first time. Results showed it had a molecular weight of 210 kDa, and mainly consisted of glucose and galactose. There were abundant filaments, randomly distributed sheet-like and flaky appearance in its surface by SEM observation. Its backbone comprised ß-(1 â†’ 6)-Glcp, α-(1 â†’ 6)-Galp and ß-(1 â†’ 3,6)-Glcp residues at 4:1:1, terminated by ß-(1 â†’ 3)-Glcp and T-Glcp residues. Rheological measurements suggested its steady flow behavior was highly dependent on concentrations. Newtonian behavior was evident at low concentrations, whereas pseudoplastic behavior was observed at high concentrations. Besides, the X-ray diffraction patterns proved the presence of amorphous structure. The conformational parameters were detected by HPSEC-MALLS-RI, revealing a random coil conformation in NaNO3 aqueous solution. This work provides a theoretical basis for the application of polysaccharides from M. albuminosa in food- and drug-based therapies.


Assuntos
Galactanos , Polissacarídeos Bacterianos , Glucanos , Peso Molecular , Polissacarídeos
2.
Food Chem ; 367: 130716, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34384981

RESUMO

Preparation of protein/polysaccharide nanocomplexes for delivering environment-sensitive bioactive compounds is significant in the fields of functional foods and pharmaceuticals. In this work, ovalbumin-pullulan (OVA-Pul) nanogels were fabricated through Maillard reaction combined with heat treatment. The results of SDS-PAGE, circular dichroism and conjugation yield (84.96%) confirmed the covalent crosslinking of ovalbumin to pullulan. Dynamic light scattering measurements indicated that nanogels and curcumin-loaded nanogels exhibited small particle diameter at around 190 nm and 160 nm, and excellent polydispersity index at 0.227 and 0.146, respectively. OVA-Pul nanogels showed good encapsulation efficiency (88.38%) and loading capacity (8.78%) for curcumin. Transmission electron microscope observations and in vitro gastrointestinal digestion suggested that OVA-Pul nanogels facilitated the controlled release of curcumin and the spherical structure of curcumin-loaded nanogels was damaged during digestion. Notably, both nanogels and curcumin-loaded nanogels showed desirable storage stability during 30 d. Hence, OVA-Pul nanogels have the potential for effectively delivering nutrients and drugs.


Assuntos
Curcumina , Glucanos , Nanogéis , Ovalbumina
3.
Food Chem ; 367: 130708, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34352692

RESUMO

In this study, we explored structural differences of five commercial samples of yeast ß-glucan. Samples were assayed for their ß-glucan content and the yeast storage carbohydrate, glycogen. The ß-glucan content ranged from 74% to 86%, the glycogen content varied from 0 to 20%. The linkage pattern of each sample was measured by the partially methylated alditol acetate method. This method showed that the samples varied from 1.9% to 9.2% branching. The side chain length distribution for each sample was analyzed by an alkaline degradation assay followed by ion chromatography. The side length distributions of the samples were shown to be similar. The samples were also analyzed by FT-IR and 1HNMR spectroscopy but it was difficult to derive quantitative differences in the samples by these methods. Our findings confirm that each proprietary source of yeast ß-glucan has a unique purity profile, branching, and linkage patterns that determine the chemical structure and composition.


Assuntos
Saccharomyces cerevisiae , beta-Glucanas , Parede Celular , Glucanos , Saccharomyces cerevisiae/genética , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Planta ; 254(6): 130, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34817644

RESUMO

MAIN CONCLUSION: A Populus euphratica NAC gene regulates (1,3; 1,4)-ß-D-glucan content in oat developing seed and improves the spikelet number and grain number per spike in transgenic oat under salinity conditions Salinity is the major factor affecting the production and quality of oat, and improving oat salt tolerance to increase yield and quality is vital. (1,3;1,4)-ß-D-glucan in Gramineae is the key component in response to various environmental signals, and it is the most important functional ingredient in oat grain. The NAC transcription factors are important candidate genes used in genetic engineering to improve plant abiotic stress tolerance. In this study, we introduced Populus euphratica PeNAC1, controlled by its own promoter, into hexaploid cultivated oat and produced six transgenic lines. Compared to the non-transgenic control, the expression of PeNAC1 significantly improved the seed germination rate, seedling survival rate, and leaf chlorophyll content in the transgenic plants under salt stress. These physiological changes increased the spikelet number and grain number per spike in the transgenic oat under salinity conditions and reduced the yield loss per plant. The results indicated that the heterologous expression of PeNAC1 plays an effective role in improving the salt tolerance in transgenic oat. In addition, overexpressing PeNAC1 significantly increased the (1,3;1,4)-ß-D-glucan content as well as the expression level of the (1,3;1,4)-ß-D-glucan biosynthetic genes AsCslF3, AsCslF6, and AsCslF9 in the transgenic lines under salt stress, which suggested that PeNAC1 regulates the synthesis of (1,3;1,4)-ß-D-glucan. Our research should assist in the discovery of the diverse action modes of NAC proteins, while PeNAC1 will be useful for improving the salt tolerance and quality of oat through molecular breeding.


Assuntos
Tolerância ao Sal , Fatores de Transcrição , Avena/genética , Avena/metabolismo , Regulação da Expressão Gênica de Plantas , Glucanos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Salinidade , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Int J Mol Sci ; 22(19)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34638811

RESUMO

A breached nasal epithelial barrier plays an important role in driving allergic rhinitis (AR). Corticosteroids remain the standard of care (SoC) but come with side effects, thus alternative safe and effective treatments able to avoid inflammation and restore barrier integrity are needed. The aim of the present study is to evaluate the barrier-forming capacity of a xyloglucan-based nasal spray (XG) and compare its efficacy to several SoC treatments (corticosteroid spray, oral mast-cell stabilizer and oral antihistamine) in reducing allergic responses in addition to its effect when concomitantly administered with an antihistamine. An ovalbumin (OVA)-induced mouse AR model was used. XG shows a significant efficacy in reducing histological damage in AR mice; improves nasal rubbing and histamine-induced hyper-responsiveness. Total and OVA-specific IgE as well as pro-inflammatory cytokines are significantly reduced compared to OVA challenged-mice, with im-proved efficacy when used as an add-on treatment. However, XG reduces mucous secreting cells (PAS-positive) and mucin mRNA expression similar to the corticosteroid-treated mice. XG-spray maintains tight junction protein expression (ZO-1) and conversely decreases HDAC1 significantly; the latter being highly expressed in AR patients. Moreover, the concomitant treatment showed in all of the endpoints a similar efficacy to the corticosteroids. This innovative approach may represent a novel therapeutic strategy for nasal respiratory diseases like AR, reducing undesirable side effects and improving the quality of life in patients.


Assuntos
Glucanos/farmacologia , Mucosa Nasal/imunologia , Sprays Nasais , Rinite Alérgica/prevenção & controle , Xilanos/farmacologia , Animais , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Rinite Alérgica/induzido quimicamente , Rinite Alérgica/imunologia , Proteína da Zônula de Oclusão-1/imunologia
6.
Mater Sci Eng C Mater Biol Appl ; 130: 112463, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34702538

RESUMO

Chronic inflammation, infection, and fixation stability disrupts bone tissue regeneration by implants. The elevated levels of inflammatory markers and reactive oxygen species (ROS) damage tissues, inhibit osteoblastic differentiation, and promote bone resorption. Activation of local and chronic inflammatory responses due to the implantable biomaterial poses a high risk of implant failure and compromised bone repair in several pathological conditions. Not much progress has been made in the development of biomaterials that can counter inflammation and ROS along with inducing osteogenic activities for managing bone defects/injuries. We have developed, for the first time, injectable polymeric hydrogels by crosslinking oxidized pullulan (OP, 1% w/v) and 8-arm PEG hydrazine (PEG-HY, 10% w/v) using pH-sensitive and dynamic hydrazone linkages at 37 °C in buffer. The hydrogels were loaded with dexamethasone (Dex), an anti-inflammatory corticosteroid and osteogenic inducer, by covalently linking it to PEG-HY by hydrazone linkages, and their morphological, injectability, viscoelastic, self-healing, swelling, and drug-release properties were investigated. The hydrogels provided a pH-sensitive sustained release of PEG-Dex conjugate (3.62 wt%, 9.22 × 10-5 mol of Dex/gram) for 28 days, with 74.54 and 55.15% PEG-Dex conjugate being released at pH 6.5 and 7.4. ABTS assay showed that hydrogels inhibited 68% radicals within 1 h, and treatment with hydrogel releasates inhibited the pro-inflammatory markers, IL-6 and IL-1ß, and elevated the anti-inflammatory marker, TGF-ß, in murine osteoblast precursor cells (MC3T3-E1). The hydrogels were found suitable for cell encapsulation and they exhibited 110% viability on treatment with releasates. Finally, the osteogenic activities of hydrogels were ascertained by alkaline phosphatase (ALP) activities, alizarin red S staining, and osteogenic gene expressions- RUNX2, Col-I, OPN, and IBSP. Overall, PEG-Dex conjugate released from hydrogels improved the cell viability and proliferation, and induced the osteoblastic differentiation. The hydrogels with their promising antioxidant and anti-inflammatory properties along with the osteogenic activities show a strong potential as an injectable, extracellular matrix (ECM)-mimicking implantable drug-depot for bone repair applications in chronic inflammatory conditions.


Assuntos
Materiais Biocompatíveis , Regeneração Óssea , Animais , Dexametasona/farmacologia , Glucanos , Hidrogéis/farmacologia , Camundongos , Osteogênese , Polietilenoglicóis
7.
J Biomed Nanotechnol ; 17(10): 1972-1983, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34706797

RESUMO

To discuss the effect of hydrophobic groups of a polymer on the structural properties and function of polymer nanoparticles (NPs), we grafted chenodeoxycholic acid (CDCA) with pullulan (PU) to form hydrophobically modified PU (PUC). Three PUC polymers, namely, PUC-1, PUC-2, and PUC-3, with different degrees of substitution were designed by changing the feed ratio of CDCA and PU. 1H-NMR spectra showed that the PUC polymer was successfully synthesized, and the degrees of hydrophobic substitution for PUC-1, PUC-2, and PUC-3 were calculated to be 10.66%, 13.92%, and 16.94%, respectively. The PUC NPs were prepared by the dialysis method and were shown to be uniformly spherical by transmission electron microscopy (TEM). The average sizes were about (220±10) nm, (203±7) nm, and (163±6) nm under dynamic light scattering (DLS) for PUC-1 NPs, PUC-2 NPs, and PUC-3 NPs, respectively. Drug release experiments showed that the three PUC/DOX NPs exhibited good sustained release. At 48 h, the IC50 of doxorubicin in inhibiting colon cancer HCT116 cells was 0.0904 µg/mL. A cell study showed that PUC-3/DOX NPs had the highest uptake efficiency by HCT116 cells with the most cytotoxicity and inhibited the migration of HCT116 cells with the highest efficiency. The structural properties and function of polymer NPs were closely related to the hydrophobic groups in the polymer, and NPs with higher hydrophobicity showed a smaller size, higher drug capacity, and greater cell efficiency.


Assuntos
Neoplasias do Colo , Nanopartículas , Neoplasias do Colo/tratamento farmacológico , Doxorrubicina/farmacologia , Glucanos , Humanos , Interações Hidrofóbicas e Hidrofílicas
8.
J Agric Food Chem ; 69(44): 13235-13245, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34708648

RESUMO

GtfB-type α-glucanotransferase enzymes from glycoside hydrolase family 70 (GH70) convert starch substrates into α-glucans that are of interest as food ingredients with a low glycemic index. Characterization of several GtfBs showed that they differ in product- and substrate specificity, especially with regard to branching, but structural information is limited to a single GtfB, preferring mostly linear starches and featuring a tunneled binding groove. Here, we present the second crystal structure of a 4,6-α-glucanotransferase (Limosilactobacillus reuteri NCC 2613) and an improved homology model of a 4,3-α-glucanotransferase GtfB (L. fermentum NCC 2970) and show that they are able to convert both linear and branched starch substrates. Compared to the previously described GtfB structure, these two enzymes feature a much more open binding groove, reminiscent of and evolutionary closer to starch-converting GH13 α-amylases. Sequence analysis of 287 putative GtfBs suggests that only 20% of them are similarly "open" and thus suitable as broad-specificity starch-converting enzymes.


Assuntos
Sistema da Enzima Desramificadora do Glicogênio , Amido , Glucanos , Sistema da Enzima Desramificadora do Glicogênio/genética , Glicosídeo Hidrolases
9.
Molecules ; 26(19)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34641277

RESUMO

The effects of immunomodulatory activity of two types of carboxymethyl pachymaran (CMP-1 and CMP-2) on cyclophosphamide (CTX)-induced mice were investigated. Both CMP-1 and CMP-2 were found to restore the splenomegaly and alleviate the spleen lesions and the mRNA expressions of TLR4, MyD88, p65 and NF-κB in spleen were also increased. CMP-1 and CMP-2 could enhance the immunity by increasing the levels of TNF-α, IL-2, IL-6, IFN-γ, Ig-A and Ig-G in serum. In addition, CMP-1 could increase the relative abundance of Bacteroidetes and reduce the relative richness of Firmicutes at the phylum level. CMP-1 and CMP-2 could reduce the relative abundance Erysipelatoclostridum at the genus level. CMP-1 and CMP-2 might enhance the immune function of immunosuppression mice by regulating the gene expression in the TLR4/NF-κB signaling pathway and changing the composition and abundance of the intestinal microbiota. The results suggested that CMP-1 and CMP-2 would be as potential immunomodulatory agents in functional foods.


Assuntos
Ciclofosfamida/efeitos adversos , Glucanos/química , Hospedeiro Imunocomprometido/efeitos dos fármacos , Fatores Imunológicos/administração & dosagem , Polissacarídeos/administração & dosagem , Esplenomegalia/tratamento farmacológico , Animais , Bacteroidetes/classificação , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Modelos Animais de Doenças , Feminino , Firmicutes/classificação , Firmicutes/genética , Firmicutes/isolamento & purificação , Alimento Funcional , Microbioma Gastrointestinal/efeitos dos fármacos , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Camundongos , Fator 88 de Diferenciação Mieloide/genética , Filogenia , Polissacarídeos/química , Polissacarídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Esplenomegalia/induzido quimicamente , Esplenomegalia/genética , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa/genética
10.
Molecules ; 26(19)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34641284

RESUMO

To elucidate the chemical linkages between lignin and carbohydrates in ginkgo cell walls, 13C-2H-enriched cell wall-dehydrogenation polymers (CW-DHP) were selectively prepared with cambial tissue from Ginkgo biloba L. by feeding D-glucose-[6-2H2], coniferin-[α-13C], and phenylalanine ammonia-lyase (PAL) inhibitor. The abundant detection of 13C and 2H confirmed that D-glucose-[6-2H2] and coniferin-[α-13C] were involved in the normal metabolism of ginkgo cambial cells that had been effectively labelled with dual isotopes. In the ginkgo CW-DHP, ketal and ether linkages were formed between the C-α of lignin side chains and carbohydrates, as revealed by solid state CP/MAS 13C-NMR differential spectroscopy. Furthermore, the DMSO/TBAH ionic liquids system was used to fractionate the ball-milled CW-DHP into three lignin-carbohydrate complex (LCC) fractions: glucan-lignin complex (GL), glucomannan-lignin complex (GML), and xylan-lignin complex (XL). The XRD determination indicated that the cellulose type I of the GL was converted into cellulose type II during the separation process. The molecular weight was in the order of Ac-GL > Ac-GML > XL. The 13C-NMR and 1H-NMR differential spectroscopy of 13C-2H-enriched GL fraction indicated that lignin was linked with cellulose C-6 by benzyl ether linkages. It was also found that there were benzyl ether linkages between the lignin side chain C-α and glucomannan C-6 in the 13C-2H-enriched GML fraction. The formation of ketal linkages between the C-α of lignin and xylan was confirmed in the 13C-2H-enriched XL fraction.


Assuntos
Carboidratos/química , Ginkgo biloba/química , Lignina/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Parede Celular/química , Glucanos/química , Glucose/química , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética , Traqueófitas/química , Xilanos/química
11.
Biomacromolecules ; 22(11): 4479-4488, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34605629

RESUMO

The fabrication of biomimetic photonic materials with environmental stimuli-responsive functions from entirely biobased materials is becoming increasingly challenging with the growing demand for biodegradable materials. Herein, the effect of glucan with different molecular weights on the mechanical performance and tunable structural color of iridescent CNC composite films was investigated. The existence of glucan did not influence the self-assembly performance of CNCs, but rather led to an improvement in the mechanical performance, enabling cholesteric CNC composite films with an adjustable structural color. Simultaneously, the iridescent films showed a conspicuous redshift and enlarged initial pitch without obstruction of the chiral structure. In response to environmental humidity, the structural colors of the iridescent composite films can be changed by regulating their chiral nematic structure. In particular, the films demonstrate a reversible structural color change between blue and red at RH between 50 and 98%. The resulting biobased iridescent composite films have potential applications in decorative coating, optical and humidity sensing, and anticounterfeiting.


Assuntos
Celulose , Nanopartículas , Glucanos , Umidade , Iridescência
12.
Biomacromolecules ; 22(11): 4701-4708, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34676760

RESUMO

α-1,6-Graft-α-1,3-glucan comprises a main-chain of α-1,6-glucan and side-chains of α-1,3-glucan. It was synthesized by a one-pot in vitro enzymatic polymerization of sucrose and dextran (α-1,6-glucan) of different molecular weights. In the presence of the high-molecular-weightdextran (Mw ≥ 650 000), the graft glucan formed a self-standing hydrogel without any cross-linker. It was possible to control the number of α-1,3-glucan side-chains by controlling the molecular weight and concentration of the dextran. Consequently, it was possible to control the compression strength of the obtained gels. Hydrogels of the graft glucan were formed by physically cross-linking the α-1,3-glucan side-chains. These physical gels are potentially useful biomaterials with high biocompatible, because the graft glucan is composed of glucose alone.


Assuntos
Glucanos , Hidrogéis , Peso Molecular , Polimerização
13.
Nutrients ; 13(10)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34684408

RESUMO

We previously showed that supplementation of a high fat diet with paramylon (PM) reduces the postprandial glucose rise, serum total and LDL cholesterol levels, and abdominal fat accumulation in mice. The purpose of this study was to explore the underlying mechanism of PM using microarray analysis. Male mice (C57BL/BL strain) were fed an experimental diet (50% fat energy) containing 5% PM isolated from Euglena gracilis EOD-1 for 12 weeks. After confirming that PM had an improving effect on lipid metabolism, we assessed ileal and hepatic mRNA expression using DNA microarray and subsequent analysis by gene ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The results suggested that dietary supplementation with PM resulted in decreased abdominal fat accumulation and serum LDL cholesterol concentrations via suppression of the digestion and absorption pathway in the ileum and activation of the hepatic PPAR signaling pathway. Postprandial glucose rise was reduced in mice fed PM, whereas changes in the glucose metabolism pathway were not detected in GO classification and KEGG pathway analysis. PM intake might enhance serum secretory immunoglobulin A concentrations via promotion of the immunoglobulin production pathway in the ileum.


Assuntos
Suplementos Nutricionais , Glucanos/administração & dosagem , Íleo/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Obesidade/metabolismo , Gordura Abdominal/metabolismo , Animais , Glicemia/metabolismo , Peso Corporal , Dieta , Ingestão de Alimentos , Euglena gracilis/química , Regulação da Expressão Gênica , Ontologia Genética , Glucanos/química , Glucanos/isolamento & purificação , Glucanos/farmacologia , Imunoglobulina A Secretora/sangue , Lipídeos/sangue , Masculino , Redes e Vias Metabólicas/genética , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência com Séries de Oligonucleotídeos , Tamanho do Órgão , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/genética
14.
Int J Pharm ; 609: 121144, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34600055

RESUMO

This study aimed to prepare pullulan films containing pomegranate seeds oil (PSO) based nanocapsules, and evaluate the formulation efficacy in the treatment of atopic dermatitis (AD)-like lesions induced by 2,4-dinitrochlorobenzene (DNCB). The Eudragit RS 100® nanocapsules (PSONC) were prepared by the interfacial precipitation of preformed polymer, whereas the films were produced by the solvent casting method. Pomegranate seed oil nanoemulsions (PSONE) were prepared by the spontaneous emulsification method for comparative reasons. Both nanosystems presented adequate mean diameter (248 ± 16 nm for PSONE and 181 ± 6 nm for PSONC), polydispersity index (below 0.2), zeta potential (-25.63 ± 1.1 mV for PSONE and + 43.13 ± 0.7 mV for PSONC) and pH in the acid range (6.77 ± 0.27 and 5.31 ± 0.17, PSONE and PSONC). By a pre-formulation study, sorbitol (6.5%) and PEG 400 (1.5%) were considered the most suitable plasticizers for developing pullulan films (6%) intending topical application. In general, pullulan films were classified as flexible and hydrophilic, with high occlusive properties, 57.6 ± 0.8%, 64.6 ± 0.8% for vehicle, PSONCF (pullulan film containing PSONC), respectively. All formulations (films and nanocarriers) presented no irritant potential in the chorioallantoic membrane test. In the in vivo model, the treatments with free PSO and PSONCF attenuated the skin injury as well as the mechanical hypernociceptive behavioral induced by DNCB exposure to mice. Importantly, the biochemical analyses provided evidence that only the treatment with PSONCF modulated the inflammatory and the oxidative stress parameters evaluated in this study. In conclusion, these data lead us to believe that PSONC incorporation into a pullulan film matrix improved the biological properties of the PSO in this AD-model.


Assuntos
Dermatite Atópica , Nanocápsulas , Romã (Fruta) , Animais , Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Dermatite Atópica/tratamento farmacológico , Glucanos , Camundongos , Nanocápsulas/uso terapêutico , Óleos Vegetais/uso terapêutico
15.
Artigo em Inglês | MEDLINE | ID: mdl-34583820

RESUMO

Pullulan is a biocompatible and water-soluble exo-polysaccharide produced by primary strains of the fungus Aureobasidium pullulans. It is frequently used in the pharmaceutical and food industries. In this study, possible cytotoxic effect of pullulan was assessed using the MTT assay in the human breast cancer (MCF-7) cell line. Micronucleus (MN), micronucleus-FISH (MN-FISH), random amplified polymorphic DNA (RAPD-PCR), and comet assays were used to investigate genotoxic and antigenotoxic effects of pullulan against mitomycin C (MMC) (at MN assay) and hydrogen peroxide (at comet assay) in human lymphocytes. Antigenotoxicity was determined using two different applications: 1 h pretreatment and simultaneous treatment. In the MTT assay, pullulan significantly reduced the cell viability at 15.6-2000 µg/mL compared to the control. No significant alterations in MN rates were found in human lymphocytes treated with different concentrations of pullulan compared to the control. In contrast, co-treatment of pullulan and MMC decreased the frequency of MN in almost all the treatment concentrations and durations compared to the MMC. No significant change was observed in the frequency of the centromere-positive C + or negative C- MNi compared to the positive control. In comet assay, pullulan did not affect comet tail intensity compared to the negative control. On the contrary, pullulan in combination with H2O2 significantly decreased tail intensity at almost all the concentrations compared to the positive control. The changes occurring in RAPD-PCR profiles following pullulan treatments included an increase or decrease in band intensity and gain or loss of bands. These results indicate that exopolysaccharide Pullulan is not genotoxic; moreover, it possesses a protective effect against MMC and H2O2 induced genotoxicity. In breast cancer cells, pullulan induced cytotoxic/anti-proliferative effect.


Assuntos
Antimutagênicos/farmacologia , Dano ao DNA/efeitos dos fármacos , Glucanos/farmacologia , Linfócitos/efeitos dos fármacos , Mutagênicos/toxicidade , Adolescente , Adulto , Ensaio Cometa , Feminino , Humanos , Hibridização in Situ Fluorescente , Células MCF-7 , Masculino , Testes para Micronúcleos , Mitomicina/antagonistas & inibidores , Adulto Jovem
16.
Viruses ; 13(9)2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34578399

RESUMO

Over the decades, the world has witnessed diverse virus associated pandemics. The significant inhibitory effects of marine sulfated polysaccharides against SARS-CoV-2 shows its therapeutic potential in future biomedical applications and drug development. Algal polysaccharides exhibited significant role in antimicrobial, antitumor, antioxidative, antiviral, anticoagulant, antihepatotoxic and immunomodulating activities. Owing to their health benefits, the sulfated polysaccharides from marine algae are a great deal of interest globally. Algal polysaccharides such as agar, alginate, carrageenans, porphyran, fucoidan, laminaran and ulvans are investigated for their nutraceutical potential at different stages of infection processes, structural diversity, complexity and mechanism of action. In this review, we focus on the recent antiviral studies of the marine algae-based polysaccharides and their potential towards antiviral medicines.


Assuntos
Antivirais/farmacologia , Organismos Aquáticos/química , Polissacarídeos/farmacologia , Alga Marinha/química , Viroses/epidemiologia , Alginatos/química , Alginatos/farmacologia , Antivirais/química , Glucanos/química , Glucanos/farmacologia , Humanos , Estrutura Molecular , Pandemias , Polissacarídeos/química , Viroses/tratamento farmacológico , Viroses/etiologia , Viroses/prevenção & controle
17.
Biomacromolecules ; 22(10): 4262-4273, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34546742

RESUMO

Gelation in the presence of cells with minimum cytotoxicity is highly desirable for materials with applications in tissue engineering. Herein, the naturally occurring polysaccharide pullulan is functionalized with thiolactones that undergo ring-opening addition of amines. As a result, the modified pullulan can be cross-linked with diamines and/or amine-containing biological substrates enhancing the system's versatility (e.g., gelatin and cell-binding ligands GHK/GRGDS). Thiolactone degrees of substitution of 2.5 or 5.0 mol % are achieved, and respective hydrogels exhibit mesh sizes of 27.8 to 49.1 nm. Cell proliferation studies on chosen gels (G' ≅ 500 Pa, over 14 days) demonstrate that for normal human dermal fibroblasts (NHDFs), both gelatin and GRGDS equally support cell proliferation, while in the case of hepatocytes (HepG2), the presence of GRGDS and GHK improve cell proliferation 10-fold compared to gelatin. Cells remain viable and in one instance were successfully encapsulated by in situ gelation, altogether confirming the mild and biocompatible nature of this strategy to produce biogels using biologically active substrates as cross-linkers.


Assuntos
Materiais Biocompatíveis , Gelatina , Glucanos , Humanos , Hidrogéis , Engenharia Tecidual
18.
Int J Mol Sci ; 22(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34502129

RESUMO

Size control is a fundamental question in biology, showing incremental complexity in plants, whose cells possess a rigid cell wall. The phytohormone auxin is a vital growth regulator with central importance for differential growth control. Our results indicate that auxin-reliant growth programs affect the molecular complexity of xyloglucans, the major type of cell wall hemicellulose in eudicots. Auxin-dependent induction and repression of growth coincide with reduced and enhanced molecular complexity of xyloglucans, respectively. In agreement with a proposed function in growth control, genetic interference with xyloglucan side decorations distinctly modulates auxin-dependent differential growth rates. Our work proposes that auxin-dependent growth programs have a spatially defined effect on xyloglucan's molecular structure, which in turn affects cell wall mechanics and specifies differential, gravitropic hypocotyl growth.


Assuntos
Glucanos/metabolismo , Ácidos Indolacéticos/metabolismo , Células Vegetais/metabolismo , Desenvolvimento Vegetal , Fenômenos Fisiológicos Vegetais , Xilanos/metabolismo , Arabidopsis/fisiologia , Parede Celular/metabolismo , Imunofluorescência , Regulação da Expressão Gênica de Plantas , Glucanos/química , Ervilhas/fisiologia , Transdução de Sinais , Xilanos/química
19.
Nutrients ; 13(9)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34578800

RESUMO

Increased dietary fiber consumption has been shown to increase human gut microbial diversity, but the mechanisms driving this effect remain unclear. One possible explanation is that microbes are able to divide metabolic labor in consumption of complex carbohydrates, which are composed of diverse glycosidic linkages that require specific cognate enzymes for degradation. However, as naturally derived fibers vary in both sugar composition and linkage structure, it is challenging to separate out the impact of each of these variables. We hypothesized that fine differences in carbohydrate linkage structure would govern microbial community structure and function independently of variation in glycosyl residue composition. To test this hypothesis, we fermented commercially available soluble resistant glucans, which are uniformly composed of glucose linked in different structural arrangements, in vitro with fecal inocula from each of three individuals. We measured metabolic outputs (pH, gas, and short-chain fatty acid production) and community structure via 16S rRNA amplicon sequencing. We determined that community metabolic outputs from identical glucans were highly individual, emerging from divergent initial microbiome structures. However, specific operational taxonomic units (OTUs) responded similarly in growth responses across individuals' microbiota, though in context-dependent ways; these data suggested that certain taxa were more efficient in competing for some structures than others. Together, these data support the hypothesis that variation in linkage structure, independent of sugar composition, governs compositional and functional responses of microbiota.


Assuntos
Microbioma Gastrointestinal , Glucanos/química , Glucanos/metabolismo , Adulto , Dieta , Carboidratos da Dieta/análise , Fibras na Dieta/análise , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Fermentação , Glucose/química , Glucose/metabolismo , Glicosídeos/química , Humanos , Masculino , RNA Ribossômico 16S/genética , Adulto Jovem
20.
Enzyme Microb Technol ; 150: 109882, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34489035

RESUMO

Glycogen branching enzymes (GBEs; 1,4-α-glucan branching enzyme; E.C. 2.4.1.18) have so far been described to be capable of both α-1,6-transglycosylation (branching) and α-1,4-hydrolytic activity. The aim of the present study was to elucidate the mode of action of three distantly related GBEs from the glycoside hydrolase family 13 by in depth analysis of the activity on a well-defined substrate. For this purpose, the GBEs from R. marinus (RmGBE), P. mobilis (PmGBE1), and B. fibrisolvens (BfGBE) were incubated with a highly pure fraction of a linear substrate of 18 anhydroglucose units. A well-known and characterized branching enzyme from E. coli (EcGBE) was also taken along. Analysis of the chain length distribution over time revealed that, next to hydrolytic and branching activity, all three GBEs were capable of generating chains longer than the substrate, clearly showing α-1,4-transglycosylation activity. Furthermore, the GBEs used those elongated chains for further branching. The sequential activity of elongation and branching enabled the GBEs to modify the substrate to a far larger extent than would have been possible with branching activity alone. Overall, the three GBEs acted ambiguous on the defined substrate. RmGBE appeared to have a strong preference towards transferring chains of nine anhydroglucose units, even during elongation, with a comparably low activity. BfGBE generated an array of elongated chains before using the chains for introducing branches while PmGBE1 exhibited a behaviour intermediate of the other two enzymes. On the basis of the mode of action revealed in this research, an updated model of the mechanism of GBEs was proposed now including the α-1,4-transglycosylation activity.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Glucanos , Glicogênio , Especificidade por Substrato
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