Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.535
Filtrar
1.
Carbohydr Polym ; 337: 122141, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38710568

RESUMO

Production of value-added compounds and sustainable materials from agro-industrial residues is essential for better waste management and building of circular economy. This includes valorization of hemicellulosic fraction of plant biomass, the second most abundant biopolymer from plant cell walls, aiming to produce prebiotic oligosaccharides, widely explored in food and feed industries. In this work, we conducted biochemical and biophysical characterization of a prokaryotic two-domain R. champanellensis xylanase from glycoside hydrolase (GH) family 30 (RcXyn30A), and evaluated its applicability for XOS production from glucuronoxylan in combination with two endo-xylanases from GH10 and GH11 families and a GH11 xylobiohydrolase. RcXyn30A liberates mainly long monoglucuronylated xylooligosaccharides and is inefficient in cleaving unbranched oligosaccharides. Crystallographic structure of RcXyn30A catalytic domain was solved and refined to 1.37 Å resolution. Structural analysis of the catalytic domain releveled that its high affinity for glucuronic acid substituted xylan is due to the coordination of the substrate decoration by several hydrogen bonds and ionic interactions in the subsite -2. Furthermore, the protein has a larger ß5-α5 loop as compared to other GH30 xylanases, which might be crucial for creating an additional aglycone subsite (+3) of the catalytic site. Finally, RcXyn30A activity is synergic to that of GH11 xylobiohydrolase.


Assuntos
Endo-1,4-beta-Xilanases , Microbioma Gastrointestinal , Glucuronatos , Oligossacarídeos , Xilosidases , Glucuronatos/metabolismo , Glucuronatos/química , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Endo-1,4-beta-Xilanases/química , Xilosidases/metabolismo , Xilosidases/química , Humanos , Cristalografia por Raios X , Xilanos/química , Xilanos/metabolismo , Domínio Catalítico , Modelos Moleculares , Especificidade por Substrato
2.
Arch Microbiol ; 206(6): 261, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38753095

RESUMO

The search for affordable enzymes with exceptional characteristics is fundamental to overcoming industrial and environmental constraints. In this study, a recombinant GH10 xylanase (Xyn10-HB) from the extremely alkaliphilic bacterium Halalkalibacterium halodurans C-125 cultivated at pH 10 was cloned and expressed in E. coli BL21(DE3). Removal of the signal peptide improved the expression, and an overall activity of 8 U/mL was obtained in the cell-free supernatant. The molecular weight of purified Xyn10-HB was estimated to be 42.6 kDa by SDS-PAGE. The enzyme was active across a wide pH range (5-10) with optimal activity recorded at pH 8.5 and 60 °C. It also presented good stability with a half-life of 3 h under these conditions. Substrate specificity studies showed that Xyn10-HB is a cellulase-free enzyme that conventionally hydrolyse birchwood and oat spelts xylans (Apparent Km of 0.46 mg/mL and 0.54 mg/mL, respectively). HPLC analysis showed that both xylans hydrolysis produced xylooligosaccharides (XOS) with a degree of polymerization (DP) ranging from 2 to 9. The conversion yield was 77% after 24 h with xylobiose and xylotriose as the main end-reaction products. When assayed on alkali-extracted wheat straw heteroxylan, the Xyn10-HB produced active XOS with antioxidant activity determined by the DPPH radical scavenging method (IC50 of 0.54 mg/mL after 4 h). Owing to its various characteristics, Xyn10-HB xylanase is a promising candidate for multiple biotechnological applications.


Assuntos
Endo-1,4-beta-Xilanases , Proteínas Recombinantes , Xilanos , Especificidade por Substrato , Hidrólise , Xilanos/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Escherichia coli/genética , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Clonagem Molecular , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Glucuronatos/metabolismo , Estabilidade Enzimática , Cinética , Peso Molecular , Oligossacarídeos/metabolismo , Dissacarídeos
3.
Molecules ; 29(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38611816

RESUMO

In this study, the α-glucosidase (maltase-glucoamylase: MGAM) and α-amylase inhibitory properties elicited by xylooligosaccharides (XOSs) prepared from dulse xylan were analysed as a potential mechanism to control postprandial hyperglycaemia for type-2 diabetes prevention and treatment. Xylan was purified from red alga dulse powder and used for enzymatic hydrolysis using Sucrase X to produce XOSs. Fractionation of XOSs produced xylobiose (X2), ß-(1→3)-xylosyl xylobiose (DX3), xylotriose (X3), ß-(1→3)-xylosyl-xylotriose (DX4), and a dulse XOS mixture with n ≥ 4 xylose units (DXM). The different fractions exhibited moderate MGAM (IC50 = 11.41-23.44 mg/mL) and α-amylase (IC50 = 18.07-53.04 mg/mL) inhibitory activity, which was lower than that of acarbose. Kinetics studies revealed that XOSs bound to the active site of carbohydrate digestive enzymes, limiting access to the substrate by competitive inhibition. A molecular docking analysis of XOSs with MGAM and α-amylase clearly showed moderate strength of interactions, both hydrogen bonds and non-bonded contacts, at the active site of the enzymes. Overall, XOSs from dulse could prevent postprandial hyperglycaemia as functional food by a usual and continuous consumption.


Assuntos
Algas Comestíveis , Glucuronatos , Hiperglicemia , Rodófitas , alfa-Amilases , Humanos , alfa-Glucosidases , Hipoglicemiantes/farmacologia , Xilanos/farmacologia , Simulação de Acoplamento Molecular , Oligossacarídeos/farmacologia
4.
Cell Death Dis ; 15(4): 267, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622131

RESUMO

Isochlorate dehydrogenase 1 (IDH1) is an important metabolic enzyme for the production of α-ketoglutarate (α-KG), which has antitumor effects and is considered to have potential antitumor effects. The activation of IDH1 as a pathway for the development of anticancer drugs has not been attempted. We demonstrated that IDH1 can limit glycolysis in hepatocellular carcinoma (HCC) cells to activate the tumor immune microenvironment. In addition, through proteomic microarray analysis, we identified a natural small molecule, scutellarin (Scu), which activates IDH1 and inhibits the growth of HCC cells. By selectively modifying Cys297, Scu promotes IDH1 active dimer formation and increases α-KG production, leading to ubiquitination and degradation of HIF1a. The loss of HIF1a further leads to the inhibition of glycolysis in HCC cells. The activation of IDH1 by Scu can significantly increase the level of α-KG in tumor tissue, downregulate the HIF1a signaling pathway, and activate the tumor immune microenvironment in vivo. This study demonstrated the inhibitory effect of IDH1-α-KG-HIF1a on the growth of HCC cells and evaluated the inhibitory effect of Scu, the first IDH1 small molecule agonist, which provides a reference for cancer immunotherapy involving activated IDH1.


Assuntos
Carcinoma Hepatocelular , Glucuronatos , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proteômica , Apigenina/farmacologia , Apigenina/uso terapêutico , Ácidos Cetoglutáricos/metabolismo , Microambiente Tumoral , Isocitrato Desidrogenase
5.
Riv Psichiatr ; 59(2): 52-59, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38651773

RESUMO

INTRODUCTION: Prenatal alcohol exposure causes a variety of impairments to the fetus called Fetal Alcohol Spectrum Disorders (FASD). Since it is very difficult to identify women that consume alcohol during pregnancy, different methods have been studied to evaluate alcohol exposure. Ethyl Glucuronide (EtG) and Fatty Acid Ethyl Esters (FAEEs) are commonly used to measure alcohol consumption in individuals at-risk for alcohol abuse, including pregnant women. MATERIALS AND METHODS: We conducted a study of two cohorts of 1.5 year-old infants (of mothers without a history of alcohol abuse) with or without meconium samples positive to both EtG and FAEEs and we evaluated their cognitive-behavioral development by the Griffiths Mental Developmental Scale (GMDS) method. Our protocol included 8 infants with meconium positive to alcohol metabolites (EtG and FAEEs) and 7 with meconium negative to alcohol metabolites. RESULTS: None of the 8 alcohol metabolites positive meconium infants exhibited distinctive facial features and growth retardation of severe FASD, showing that other factors may contribute to the FASD onset but elevations in EtG and FAEEs in the meconium were significantly associated with disrupted neurodevelopment and adaptive functions within the first year and a half of life. Indeed, we found out that infants with meconium positive for both EtG and FAEEs, although without displaying any FASD morphological features, had a delay in the fine regulation of their own locomotory capabilities. CONCLUSIONS: Further analyses and larger studies are needed to estimate the right link between prenatal alcohol exposure and the different range of disorders connected but this study provides an additional step in the field of FASD in order to suggest early treatments for at-risk newborns and infants.


Assuntos
Biomarcadores , Transtornos do Espectro Alcoólico Fetal , Glucuronatos , Mecônio , Humanos , Mecônio/química , Mecônio/metabolismo , Projetos Piloto , Feminino , Transtornos do Espectro Alcoólico Fetal/metabolismo , Biomarcadores/metabolismo , Glucuronatos/análise , Lactente , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ácidos Graxos/metabolismo , Ácidos Graxos/análise , Consumo de Bebidas Alcoólicas/efeitos adversos , Recém-Nascido , Locomoção , Ésteres/análise , Desenvolvimento Infantil
6.
Appl Microbiol Biotechnol ; 108(1): 312, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38683242

RESUMO

The xylanolytic enzymes Clocl_1795 and Clocl_2746 from glycoside hydrolase (GH) family 30 are highly abundant in the hemicellulolytic system of Acetivibrio clariflavus (Hungateiclostridium, Clostridium clariflavum). Clocl_1795 has been shown to be a xylobiohydrolase AcXbh30A releasing xylobiose from the non-reducing end of xylan and xylooligosaccharides. In this work, biochemical characterization of Clocl_2746 is presented. The protein, designated AcXyn30B, shows low sequence similarity to other GH30 members and phylogenetic analysis revealed that AcXyn30B and related proteins form a separate clade that is proposed to be a new subfamily GH30_12. AcXyn30B exhibits similar specific activity on glucuronoxylan, arabinoxylan, and aryl glycosides of linear xylooligosaccharides suggesting that it is a non-specific xylanase. From polymeric substrates, it releases the fragments of degrees of polymerization (DP) 2-6. Hydrolysis of different xylooligosaccharides indicates that AcXyn30B requires at least four occupied catalytic subsites for effective cleavage. The ability of the enzyme to hydrolyze a wide range of substrates is interesting for biotechnological applications. In addition to subfamilies GH30_7, GH30_8, and GH30_10, the newly proposed subfamily GH30_12 further widens the spectrum of GH30 subfamilies containing xylanolytic enzymes. KEY POINTS: Bacterial GH30 endoxylanase from A. clariflavus (AcXyn30B) has been characterized AcXyn30B is non-specific xylanase hydrolyzing various xylans and xylooligosaccharides Phylogenetic analysis placed AcXyn30B in a new GH30_12 subfamily.


Assuntos
Clostridiales , Endo-1,4-beta-Xilanases , Xilanos , Dissacarídeos/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/química , Glucuronatos/metabolismo , Hidrólise , Oligossacarídeos/metabolismo , Filogenia , Especificidade por Substrato , Xilanos/metabolismo , Clostridiales/enzimologia , Clostridiales/genética
7.
Bioresour Technol ; 400: 130702, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38615968

RESUMO

The bioconversion of lignocellulosic biomass into novel bioproducts is crucial for sustainable biorefineries, providing an integrated solution for circular economy objectives. The current study investigated a novel microwave-assisted acidic deep eutectic solvent (DES) pretreatment of waste cocoa pod husk (CPH) biomass to extract xylooligosaccharides (XOS). The sequential DES (choline chloride/citric acid, molar ratio 1:1) and microwave (450W) pretreatment of CPH biomass was effective in 67.3% xylan removal with a 52% XOS yield from total xylan. Among different XOS of varying degrees of polymerization, a higher xylobiose content corresponding to 69.3% of the total XOS (68.22 mg/g CPH) from liquid fraction was observed. Enzymatic hydrolysis of residual xylan from pretreated CPH biomass with low commercial xylanase (10 IU/g) concentration yielded 24.2% XOS. The MW-ChCl/citric acid synergistic pretreatment approach holds great promise for developing a cost-effective and environmentally friendly method contributing to the sustainable production of XOS from agricultural waste streams.


Assuntos
Biomassa , Cacau , Solventes Eutéticos Profundos , Glucuronatos , Micro-Ondas , Oligossacarídeos , Oligossacarídeos/química , Cacau/química , Cacau/metabolismo , Hidrólise , Solventes Eutéticos Profundos/química , Xilanos , Biotecnologia/métodos , Ácidos/química , Solventes/química
8.
J Nutr Biochem ; 129: 109640, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38583497

RESUMO

Midlife overweight and obesity are risk factors of cognitive decline and Alzheimer' s disease (AD) in late life. In addition to increasing risk of obesity and cognitive dysfunction, diets rich in fats also contributes to an imbalance of gut microbiota. Xylo-oligosaccharides (XOS) are a kind of prebiotic with several biological advantages, and can selectively promote the growth of beneficial microorganisms in the gut. To explore whether XOS can alleviate cognitive decline induced by high-fat diet (HFD) through improving gut microbiota composition, mice were fed with normal control or 60% HFD for 9 weeks to induce obesity. After that, mice were supplemented with XOS (30 g or 60 g/kg-diet) or without, respectively, for 12 weeks. The results showed that XOS inhibited weight gain, decreased epidydimal fat weight, and improved fasting blood sugar and blood lipids in mice. Additionally, XOS elevated spatial learning and memory function, decreased amyloid plaques accumulation, increased brain-derived neurotrophic factor levels, and improved neuroinflammation status in hippocampus. Changes in glycerolipids metabolism-associated lipid compounds caused by HFD in hippocampus were reversed after XOS intervention. On the other hand, after XOS intervention, increase in immune-mediated bacteria, Faecalibacterium was observed. In conclusion, XOS improved gut dysbiosis and ameliorated spatial learning and memory dysfunction caused by HFD by decreasing cognitive decline-associated biomarkers and changing lipid composition in hippocampus.


Assuntos
Dieta Hiperlipídica , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Oligossacarídeos , Prebióticos , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Oligossacarídeos/farmacologia , Oligossacarídeos/administração & dosagem , Masculino , Camundongos , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Obesidade/metabolismo , Obesidade/microbiologia , Glucuronatos/farmacologia , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Lipídeos/sangue , Disfunção Cognitiva/prevenção & controle , Disbiose , Metabolismo dos Lipídeos/efeitos dos fármacos
9.
Food Funct ; 15(6): 3122-3129, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38426554

RESUMO

Little is known regarding the effects of xylooligosaccharides (XOS) on insulin resistance (IR) in gestational diabetes mellitus (GDM). We aimed to investigate this issue and its mechanism. Sixty female mice were randomly allotted to 4 groups (n = 15): control, high fat diet (HFD), GDM, and GDM + XOS. The control mice were fed an AIN-93 diet, while the mice in the other groups were fed 45% HFD. After pregnancy, mice in GDM and GDM + XOS groups were intraperitoneally injected with 30 mg kg-1 streptozocin for 3 days from the first day of pregnancy. Mice in the GDM + XOS group were then fed an HFD containing 2% XOS. Fasting glucose and insulin levels were monitored. The fecal Akkermansia muciniphila (Akk. muciniphila) and Bifidobacterium were measured by qPCR. The Chiu scores were calculated from hematoxylin-eosin (HE)-stained ileal tissues. Phosphorylated Akt in the liver and occludin and ZO-1 in the intestinal tissues were determined by western blotting. XOS reduced (p < 0.05) fasting blood glucose and insulin and HOMA-IR, and increased (p < 0.05) Akt phosphorylation in the livers of GDM mice. Moreover, XOS decreased (p < 0.05) TNFα, IL-1ß, IL-15 and LPS in the serum, increased (p < 0.05) fecal Akk. muciniphila abundance, lowered (p < 0.05) Chiu's scores, and enhanced (p < 0.05) occludin and ZO-1 expression. XOS ameliorate IR by increasing Akk. muciniphila and improving intestinal barrier dysfunction in GDM mice.


Assuntos
Diabetes Gestacional , Gastroenteropatias , Glucuronatos , Resistência à Insulina , Enteropatias , Oligossacarídeos , Gravidez , Humanos , Feminino , Animais , Camundongos , Diabetes Gestacional/tratamento farmacológico , Diabetes Gestacional/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ocludina , Insulina , Akkermansia
10.
Bioresour Technol ; 398: 130526, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38437967

RESUMO

Globally, the demands for sustainably sourced functional foods like prebiotic oligosaccharides have been constantly increasing. This study assessed the potential of pineapple leaves (PL) as lignocellulosic feedstock for sustainable production of cellulose and hemicellulose-derived oligosaccharides through its hydrothermal pretreatment (HT) followed by controlled enzymatic hydrolysis. PL was subjected to HT at 160, 175, and 190 °C for 20, 30, 60, and 90 min without any catalyst for xylooligosaccharide (XOS) production, whereas, the resulting solid content after HT was subjected to controlled enzymatic hydrolysis by commercial cellulase using conduritol B epoxide (0.5-5 mM) for glucooligosaccharides (GOS) production. HT at 160 °C for 60 min resulted in maximum yield of XOS and GOS at 23.7 and 18.3 %, respectively, in the liquid phase. Controlled enzymatic hydrolysis of HT treated (160 °C) PL solids for 20 and 30 min yielded âˆ¼ 174 mg cellobiose/g dry biomass within 24 h, indicating overall high oligosaccharide production.


Assuntos
Ananas , Celulose , Polissacarídeos , Hidrólise , Oligossacarídeos , Glucuronatos
11.
Traffic Inj Prev ; 25(4): 553-561, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38497827

RESUMO

OBJECTIVE: The first aim of the study was to identify sex differences in the use of psychoactive substances among subjects with a previous driving under the influence (DUI) episode. The secondary objective was to propose specific strategies for medico-legal improvements. METHODS: This was a retrospective observational study that took place between June 1, 2019, and August 31, 2023. It was conducted on DUI subjects examined for reinstatement of their driver's license using an integrated medico-legal and toxicological approach. Ethyl glucuronide (EtG) and illicit psychoactive substances were determined from hair samples. We performed descriptive statistical analyses for the entire sample as well as separately by sex. Additionally, we conducted binary logistic regression analyses separately for males and females to identify protective/risk factors associated with previous road accidents and judgments of unfitness to drive due to excessive alcohol consumption (EtG ≥ 30 pg/mg). RESULTS: The study included 2,221 subjects, comprising 1,970 men and 251 women. Men exhibited a higher prevalence of tobacco, alcohol, and illicit psychoactive substance use. Women were more frequently co-users of alcohol and psychoactive substances and involved in road accidents at the time of DUI. Among the men, being married or having a partner was found to be a protective factor concerning past traffic accidents. For both sexes, a DUI episode with a blood alcohol concentration (BAC) exceeding 1.5 g/L or the co-ingestion of alcohol and drugs was identified as a risk factor for road accident involvement. For men, smoking more than 20 cigarettes per day and, for women, having a DUI episode with a BAC over 1.5 g/L were the main factors indicating unfitness to drive, as determined through high hair EtG levels (> 30 pg/mg). Women with a previous history of road accidents were less likely to have EtG levels of 30 pg/mg or more. CONCLUSIONS: The study confirmed sex differences in subjects with a previous DUI episode. A BAC exceeding 1.5 g/L or the simultaneous use of alcohol and drugs at the time of DUI necessitate careful assessment of both men and women seeking driver's license reinstatement. In women, a BAC exceeding 1.5 g/L is considered a risk factor for a subsequent judgment of unfitness to drive. The medico-legal assessment should also involve a thorough investigation of smoking habits in men, as these habits could be related to an increased risk of excessive alcohol consumption.


Assuntos
Condução de Veículo , Dirigir sob a Influência , Glucuronatos , Transtornos Relacionados ao Uso de Substâncias , Feminino , Humanos , Masculino , Acidentes de Trânsito , Concentração Alcoólica no Sangue , Etanol , Caracteres Sexuais , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Estudos Retrospectivos
12.
Appl Environ Microbiol ; 90(4): e0222323, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38497645

RESUMO

An uncharacterized gene encoding a glycoside hydrolase family 43-like enzyme from Clostridium boliviensis strain E-1 was identified from genomic sequence data, and the encoded enzyme, CbE1Xyn43-l, was produced in Escherichia coli. CbE1Xyn43-l (52.9 kDa) is a two-domain endo-ß-xylanase consisting of a C-terminal CBM6 and a GH43-like catalytic domain. The positions of the catalytic dyad conserved in GH43, the catalytic base (Asp74), and proton donor (Glu240) were identified in alignments including GH43-enzymes of known 3D-structure from different subfamilies. CbE1Xyn43-l is active at pH 7.0-9.0, with optimum temperature at 65°C, and a more than 7 days' half-life in irreversible deactivation studies at this temperature. The enzyme hydrolyzed birchwood xylan, quinoa stalks glucuronoarabinoxylan, and wheat arabinoxylan with xylotriose and xylotetraose as major hydrolysis products. CbE1Xyn43-l also released xylobiose from pNPX2 with low turnover (kcat of 0.044 s-1) but was inactive on pNPX, showing that a degree of polymerization of three (DP3) was the smallest hydrolyzable substrate. Divalent ions affected the specific activity on xylan substrates, which dependent on the ion could be increased or decreased. In conclusion, CbE1Xyn43-l from C. boliviensis strain E-1 is the first characterized member of a large group of homologous hypothetical proteins annotated as GH43-like and is a thermostable endo-xylanase, producing xylooligosaccharides of high DP (xylotriose and xylotetraose) producer. IMPORTANCE: The genome of Clostridium boliviensis strain E-1 encodes a number of hypothetical enzymes, annotated as glycoside hydrolase-like but not classified in the Carbohydrate Active Enzyme Database (CAZy). A novel thermostable GH43-like enzyme is here characterized as an endo-ß-xylanase of interest in the production of prebiotic xylooligosaccharides (XOs) from different xylan sources. CbE1Xyn43-l is a two-domain enzyme composed of a catalytic GH43-l domain and a CBM6 domain, producing xylotriose as main XO product. The enzyme has homologs in many related Clostridium strains which may indicate a similar function and be a previously unknown type of endo-xylanase in this evolutionary lineage of microorganisms.


Assuntos
Glucuronatos , Glicosídeo Hidrolases , Oligossacarídeos , Xilanos , Xilanos/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Especificidade por Substrato , Clostridium/genética , Clostridium/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Hidrólise , Estabilidade Enzimática , Concentração de Íons de Hidrogênio
13.
Phytomedicine ; 128: 155418, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38518647

RESUMO

BACKGROUND: Scutellaria barbata D. Don (SB), commonly known as Ban Zhi Lian and firstly documented by Shigong Chen, is a dried whole plant that has been studied for its therapeutic effects on breast cancer, colon cancer, and prostate cancer. Among its various compounds, scutellarin (SCU) has been demonstrated with anti-tumor effects. PURPOSE: This study aimed to evaluate the effects of SB water extract (SBW) and scutellarin on breast cancer stem cells (BCSCs), and to investigate their potential therapeutic effects on breast tumors in mice. METHODS: BCSCs were enriched from human breast cancer cells (MDA-MB-231 and MDA-MB-361) and their characteristics were analyzed. The effects of varying concentrations of SBW and scutellarin on cell viability, proliferation, self-renewal, and migration abilities were studied, along with the underlying mechanisms. The in vivo anti-tumor effects of scutellarin were further evaluated in SCID/NOD mice. Firstly, mice were inoculated with naïve BCSCs and subjected to treatment with scutellarin or vehicle. Secondly, BCSCs were pre-treated with scutellarin or vehicle prior to inoculation into mice. RESULTS: The derived BCSCs expressed CD44, CD133 and ALDH1, but not CD24, indicating that BCSCs have been successfully induced from both MDA-MB-231 and MDA-MB-361 cells. Both SBW and scutellarin reduced the viability, proliferation, sphere and colony formation, and migration of BCSCs. In mice with tumors derived from naïve BCSCs, scutellarin significantly reduced tumor growth, expression of proliferative (Ki67) and stem cell markers (CD44), and lung metastasis. In addition, pre-treatment with scutellarin also slowed tumor growth. Western blot results suggested the involvement of Wnt/ß-catenin, NF-κB, and PTEN/Akt/mTOR signaling pathways underlying the inhibitory effects of scutellarin. CONCLUSION: Our study demonstrated for the first time that both SB water extract and scutellarin could reduce the proliferation and migration of BCSCs in vitro. Scutellarin was shown to possess novel inhibitory activities in BCSCs progression. These findings suggest that Scutellaria barbata water extract, in particular, scutellarin, may have potential to be further developed as an adjuvant therapy for reducing breast cancer recurrence.


Assuntos
Apigenina , Neoplasias da Mama , Proliferação de Células , Glucuronatos , Camundongos Endogâmicos NOD , Células-Tronco Neoplásicas , Scutellaria , Animais , Apigenina/farmacologia , Scutellaria/química , Glucuronatos/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Camundongos SCID , Antineoplásicos Fitogênicos/farmacologia , Camundongos , Extratos Vegetais/farmacologia , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Receptores de Hialuronatos/metabolismo
14.
Sud Med Ekspert ; 67(1): 56-61, 2024.
Artigo em Russo | MEDLINE | ID: mdl-38353016

RESUMO

Quantitative determination of ethyl glucuronide (EtG) in different biological objects in recent years has been positioned as one of the most reliable biomarkers of unconditional alcohol consumption. The aim of the study is to summarize the analytical methods of alcohol consumption testing with the use of EtG currently available in domestic and foreign literature and to present a schematic overview of possible errors in reproducibility and interpretation of research on EtG results, which may limit their use in forensic medical practice. The main objective is to increase the reliability and validity of EtG as a marker of ethanol consumption.


Assuntos
Consumo de Bebidas Alcoólicas , Detecção do Abuso de Substâncias , Reprodutibilidade dos Testes , Detecção do Abuso de Substâncias/métodos , Glucuronatos , Biomarcadores , Etanol
15.
Carbohydr Polym ; 331: 121869, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38388037

RESUMO

Xylooligosaccharides (XOS) have been employed as prebiotics containing oligomers of varying sizes or molecular ratios. XOS with a low degree of polymerization (DP) has been demonstrated to have high prebiotic potential. However, there is limited information regarding the specific chain length of XOS required to elicit distinct responses in the gut microbiota. In this study, we aimed to explore whether variations in XOS DP could alter the fate of colonic fermentation. Five XOS fractions (BWXFs) with DP ranges of >40, 20-40, 10-20, 5-10, and 2-4 were prepared by beechwood xylan autohydrolysis and tested on human gut microbiota. Extracellular XOS degradation was observed for molecules with a DP exceeding 5. BWXF treatments altered the microbial community structures, and substrate size-dependent effects on the microbial composition and metabolic outputs were observed. Bacteroidaceae were specifically enriched by xylan. Lachnospiraceae were particularly stimulated by XOS with a DP of 20-40 and 2-4. Bifidobacteriaceae were notably enriched by XOS with a DP of 5-20. High butyrate yields were obtained from cultures containing long-chain BWXFs. Microbiota responses differed with XOS DP composition changes, and microbial competition with XOS with a DP of 2-4 requires further exploration.


Assuntos
Prebióticos , Xilanos , Humanos , Fermentação , Xilanos/metabolismo , Colo/metabolismo , Oligossacarídeos/metabolismo , Glucuronatos/metabolismo
16.
Clin Exp Pharmacol Physiol ; 51(4): e13845, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38382550

RESUMO

Abnormalities in vascular smooth muscle cells (VSMCs) are pivotal in the pathogenesis of cardiovascular pathologies such as atherosclerosis and hypertension. Scutellarin (Scu), a flavonoid derived from marigold flowers, exhibits a spectrum of biological activities including anti-inflammatory, antioxidant, antitumor, immunomodulatory and antimicrobial effects. Notably, Scu has demonstrated the capacity to mitigate vascular endothelial damage and prevent atherosclerosis via its antioxidative properties. Nevertheless, the influence of Scu on the formation of VSMC-derived foam cells remains underexplored. In this study, Scu was evidenced to efficaciously attenuate oleic acid (OA)-induced lipid accumulation and the upregulation of adipose differentiation-associated protein Plin2 in a dose- and time-responsive manner. We elucidated that Scu effectively diminishes OA-provoked VSMC foam cell formation. Further, it was established that Scu pretreatment augments the protein expression of LC3B-II and the mRNA levels of Map1lc3b and Becn1, concurrently diminishing the protein levels of the NLRP3 inflammasome compared to the OA group. Activation of autophagy through rapamycin attenuated NLRP3 inflammasome protein expression, intracellular lipid droplet content and Plin2 mRNA levels. Scu also counteracted the OA-induced decrement of LC3B-II levels in the presence of bafilomycin-a1, facilitating the genesis of autophagosomes and autolysosomes. Complementarily, in vivo experiments revealed that Scu administration substantially reduced arterial wall thickness, vessel wall cross-sectional area, wall-to-lumen ratio and serum total cholesterol levels in comparison to the high-fat diet model group. Collectively, our findings suggest that Scu attenuates OA-induced VSMC foam cell formation through the induction of autophagy and the suppression of NLRP3 inflammasome activation.


Assuntos
Apigenina , Aterosclerose , Glucuronatos , Inflamassomos , Humanos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Células Espumosas/metabolismo , Células Espumosas/patologia , Músculo Liso Vascular/metabolismo , Ácido Oleico/farmacologia , Ácido Oleico/metabolismo , Aterosclerose/metabolismo , Autofagia , RNA Mensageiro/metabolismo , Miócitos de Músculo Liso/metabolismo
17.
Drug Alcohol Depend ; 257: 111128, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38394813

RESUMO

The increase in alcohol consumption in society has not only led to a number of medical issues but has also become a matter of considerable legal importance. Thus, there is both scientific interest and the necessity to diagnose alcohol abuse in the application of the provisions of the law through laboratory tests that ensure maximum objectivity. The purpose of this work is to study and compare the diagnostic performance of two of the main markers of alcohol abuse, serum carbohydrate-deficient transferrin (CDT) and Ethyl glucuronide (EtG) in a group of 336 driving under the influence (DUI) of alcohol offenders. Thus, it is possible to establish the best marker of alcohol consumption in order to assess the fitness to drive of DUI subjects.EtG was detected in 55 hair samples, while CDT was detected in 5 blood samples. Of the EtG-positive subjects 96,4% had CDT values below the cut-off. While CDT refers to an alcohol consumption of approximately the previous 10 days, EtG allows to detect an excessive alcohol consumption of the last few months. Because of these two different time-windows, EtG proves to be more reliable, since it is more difficult for subjects to change their drinking practice to test negative to toxicological analysis. The determination of Ethyl glucuronide on hair matrix is a valuable tool for the diagnosis of alcohol abuse, with high sensitivity and specificity and certainly greater reliability than traditional markers such as CDT, being a direct marker of alcohol consumption.


Assuntos
Alcoolismo , Transferrina/análogos & derivados , Humanos , Alcoolismo/diagnóstico , Reprodutibilidade dos Testes , Biomarcadores , Consumo de Bebidas Alcoólicas , Glucuronatos , Cabelo/química , Detecção do Abuso de Substâncias
18.
Food Funct ; 15(2): 894-905, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38168976

RESUMO

Xylooligosaccharides (XOSs) have recently garnered interest for their potential as an anti-constipation agent. In this study, we investigated the effects of XOSs derived from corn cobs on constipation in mice through a comprehensive analysis of both the metabolome and transcriptome. Our multi-omics approach revealed that XOSs primarily modulated butanoate metabolism and steroid hormone biosynthesis pathways, as well as key signaling pathways such as PPAR and NF-kappa B. Notably, we observed a decrease in inflammatory biomarker expression and an elevation of butyric acid metabolite levels with XOSs treatment. A deeper analysis of gene expression and metabolite alterations highlighted significant changes in genes encoding critical enzymes and metabolites involved in these pathways. Overall, these findings underscore the considerable potential of XOSs derived from corn cobs as a dietary supplement for effectively alleviating constipation.


Assuntos
Glucuronatos , Metabolômica , Oligossacarídeos , Zea mays , Camundongos , Animais , Zea mays/genética , Perfilação da Expressão Gênica , Transcriptoma , Metaboloma , Constipação Intestinal/tratamento farmacológico , Constipação Intestinal/genética
19.
Bioresour Technol ; 395: 130352, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272142

RESUMO

The productive separation and conversion of corn straw offers significant prospects for the economic viability of biorefineries centered on straw resources. In this work, a graded utilization method was proposed to produce xylo-oligosaccharides (XOS), ethanol and lignin from corn straw by nicotinic acid (NA) hydrolysis and water/pentanol pretreatment. A XOS yield of 52.6 % was achieved under optimized conditions of 100 mM NA, 170 °C and 30 min. The solid residue was directly treated with water/pentanol, achieving a lignin removal rate of 79.7 %, and the total XOS yield was improved to 62.6 %. The lignin recovered from pentanol had a high purity of 97.6 %, with high phenolic OH content. Simultaneous saccharification and fermentation of final residue resulted in an ethanol yield of 92.0 %, which yielded 55.3 g/L ethanol. Thus, NA hydrolysis and water/pentanol pretreatment provided an efficient, environmentally friendly approach to fractionate corn straw for the co-production of XOS, ethanol, and lignin.


Assuntos
Glucuronatos , Lignina , Niacina , Lignina/química , Zea mays , Etanol , Pentanóis , Hidrólise , Oligossacarídeos , Fermentação , Água
20.
Biotechnol Adv ; 72: 108319, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38280495

RESUMO

The construction of high-performance microbial cell factories (MCFs) is the centerpiece of biomanufacturing. However, the complex metabolic regulatory network of microorganisms poses great challenges for the efficient design and construction of MCFs. The genome-scale metabolic network models (GSMs) can systematically simulate the metabolic regulation process of microorganisms in silico, providing effective guidance for the rapid design and construction of MCFs. In this review, we summarized the development status of 16 important industrial microbial GSMs, and further outline the technologies or methods that continuously promote high-quality GSMs construction from five aspects: I) Databases and modeling tools facilitate GSMs reconstruction; II) evolving gap-filling technologies; III) constraint-based model reconstruction; IV) advances in algorithms; and V) developed visualization tools. In addition, we also summarized the applications of GSMs in guiding metabolic engineering from four aspects: I) exploring and explaining metabolic features; II) predicting the effects of genetic perturbations on metabolism; III) predicting the optimal phenotype; IV) guiding cell factories construction in practical experiment. Finally, we discussed the development of GSMs, aiming to provide a reference for efficiently reconstructing GSMs and guiding metabolic engineering.


Assuntos
Dissacarídeos , Glucuronatos , Engenharia Metabólica , Redes e Vias Metabólicas , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/genética , Fenótipo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...