RÉSUMÉ
The possibility to print electronics by means of office tools has remarkedly increased the possibility to design affordable and robust point-of-care/need devices. However, conductive inks suffer from low electrochemical and rheological performances limiting their applicability in biosensors. Herein, a fast CO2 laser approach to activate printed carbon inks towards direct enzymatic bioelectrocatalysis (3rd generation) is proposed and exploited to build biosensors for D-fructose analysis in biological fluids. The CO2 laser treatment was compared with two lab-grade printed transducers fabricated with solvent (SB) and water (WB) based carbon inks. The use of the laser revealed significant morpho-chemical variations on the printed inks and was investigated towards enzymatic direct catalysis, using Fructose dehydrogenase (FDH) integrated into entirely lab-produced biosensors. The laser-driven activation of the inks unveils the inks' direct electron transfer (DET) ability between FDH and the electrode surface. Sub-micromolar limits of detection (SB-ink LOD = 0.47 µM; WB-ink LOD = 0.24 µM) and good linear ranges (SB-ink: 5-100 µM; WB-ink: 1-50 µM) were obtained, together with high selectivity due to use of the enzyme and the low applied overpotential (0.15 V vs. pseudo-Ag/AgCl). The laser-activated biosensors were successfully used for D-fructose determination in complex synthetic and real biological fluids (recoveries: 93-112%; RSD ≤8.0%, n = 3); in addition, the biosensor ability for continuous measurement (1.5h) was also demonstrated simulating physiological D-fructose fluctuations in cerebrospinal fluid.
Sujet(s)
Techniques de biocapteur , Fructose , Graphite , Encre , Fructose/analyse , Fructose/composition chimique , Graphite/composition chimique , Humains , Carbohydrate dehydrogenases/composition chimique , Techniques électrochimiques/méthodes , Transport d'électrons , Limite de détection , Lasers à gaz , Enzymes immobilisées/composition chimique , ÉlectrodesRÉSUMÉ
Deciphering the mechanisms underlying the direct association between fructose consumption and the onset and progression of non-alcoholic fatty liver disease (NAFLD), as well as the high prevalence of metabolic syndrome (MetS), is of great importance for adopting potential nutritional strategies. Thus, an evaluation of the impact of sustained high fructose consumption on the liver physiology of Wistar rats was made. Moreover, the effectiveness of a dietary pomegranate-derived supplement (P) at counteracting fructose-induced liver injury was also assessed. For unveiling the underlying mechanisms, an untargeted proteomic analysis of the livers from nineteen Wistar rats fed on a basal commercial feed and supplemented with either drinking water (C) (n = 6), 30 % (w/v) fructose in drinking water (F) (n = 7) or 30 % (w/v) fructose solution plus 0.2 % (w/v) P (F+P) (n = 6) was assessed. Fructose intake severely increased the abundance of several energy-production related-proteins, such as fructose-bisphosphate aldolase or fatty acid synthase, among others, as well as diminished the amount of another ones, such as carnitine O-palmitoyl transferase or different subunits of acyl-coenzyme A oxidase. These changes could facilitate mitochondrial disturbances and oxidative stress. Regarding the hepatic proteome of F, P extract restored mitochondrial homeostasis and strengthened endogenous antioxidant mechanisms diminishing the amount of proteins involved in process that could increase the oxidative status, as well as increasing both the quantity of several proteins involved in proteasome functionality, as expressing changes in the amount of certain RNA-splicing related-proteins, regarding F proteome.
Sujet(s)
Modèles animaux de maladie humaine , Fructose , Foie , Stéatose hépatique non alcoolique , Grenadier commun , Protéomique , Rat Wistar , Animaux , Stéatose hépatique non alcoolique/métabolisme , Stéatose hépatique non alcoolique/prévention et contrôle , Grenadier commun/composition chimique , Mâle , Foie/métabolisme , Foie/effets des médicaments et des substances chimiques , Rats , Compléments alimentaires , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/métabolisme , Extraits de plantes/pharmacologie , Stress oxydatif/effets des médicaments et des substances chimiquesRÉSUMÉ
Non-digestible oligosaccharides (OS) and allulose have beneficial health properties and could reduce the amount of added sugar in baked goods. In this study allulose and various OS [fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), lactosucrose (LOS), isomalto-oligosaccharides (IMO), Promitor 70R (P70R), and xylo-oligosaccharides (XOS)] were added to a wire-cut cookie formulation at concentrations determined to have similar effects on the gelatinization temperature (Tgel) of starch relative to sucrose. Different baking performance attributes of the doughs and cookies were assessed, including: appearance, spread, color, texture, and % moisture loss after baking. The results were correlated to: OS solution and solid properties and OS effects on starch thermal events (gelatinization, pasting, and retrogradation). The Tgel-matching formulation protocol was effective in producing reduced-sugar cookies which had similar appearance, color, and spread attributes compared to the sucrose control; however, cookie texture significantly varied. Cookies containing allulose were the least similar to the control, having darker color, reduced spread, and softer cake-like texture. The only OS cookies that matched the texture of the sucrose control contained LOS, while P70R cookies were the hardest. Cookie texture correlated strongly with the % total moisture loss after baking (r = -0.8763) and was best explained by OS solution viscosity: more viscous OS solutions limited moisture release and resulted in harder cookies. The Tgel of starch also correlated with OS solution viscosity (r = 0.7861) and should be accounted for in reduced sugar applications. The OS recommended as sucrose replacers in cookies based on principal component analysis groupings were: XOS > IMO > LOS > and GOS.
Sujet(s)
Oligosaccharides , Oligosaccharides/composition chimique , Cuisine (activité)/méthodes , Saccharose/composition chimique , Amidon/composition chimique , Couleur , Eau/composition chimique , Fructose/composition chimique , Manipulation des aliments/méthodes , Viscosité , TempératureRÉSUMÉ
Sex differences may play a role in the etiopathogenesis and severity of metabolic dysfunction-associated steatotic liver disease (MASLD), a disorder characterized by excessive fat accumulation associated with increased inflammation and oxidative stress. We previously observed the development of steatosis specifically in female rats fed a high-fat diet enriched with liquid fructose (HFHFr) for 12 weeks. The aim of this study was to better characterize the observed sex differences by focusing on the antioxidant and cytoprotective pathways related to the KEAP1/NRF2 axis. The KEAP1/NRF2 signaling pathway, autophagy process (LC3B and LAMP2), and endoplasmic reticulum stress response (XBP1) were analyzed in liver homogenates in male and female rats that were fed a 12-week HFHFr diet. In females, the HFHFr diet resulted in the initial activation of the KEAP1/NRF2 pathway, which was not followed by the modulation of downstream molecular targets; this was possibly due to the increase in KEAP1 levels preventing the nuclear translocation of NRF2 despite its cytosolic increase. Interestingly, while in both sexes the HFHFr diet resulted in an increase in the levels of LC3BII/LC3BI, a marker of autophagosome formation, only males showed a significant upregulation of LAMP2 and XBP1s; this did not occur in females, suggesting impaired autophagic flux in this sex. Overall, our results suggest that males are characterized by a greater ability to cope with an HFHFr metabolic stimulus mainly through an autophagic-mediated proteostatic process while in females, this is impaired. This might depend at least in part upon the fine modulation of the cytoprotective and antioxidant KEAP1/NRF2 pathway resulting in sex differences in the occurrence and severity of MASLD. These results should be considered to design effective therapeutics for MASLD.
Sujet(s)
Alimentation riche en graisse , Fructose , Protéine-1 de type kelch associée à ECH , Facteur-2 apparenté à NF-E2 , Caractères sexuels , Transduction du signal , Animaux , Facteur-2 apparenté à NF-E2/métabolisme , Femelle , Mâle , Alimentation riche en graisse/effets indésirables , Transduction du signal/effets des médicaments et des substances chimiques , Rats , Protéine-1 de type kelch associée à ECH/métabolisme , Autophagie/effets des médicaments et des substances chimiques , Protéine-1 liant la boite X/métabolisme , Protéine-1 liant la boite X/génétique , Modèles animaux de maladie humaine , Stéatose hépatique/métabolisme , Stéatose hépatique/anatomopathologie , Foie/métabolisme , Foie/anatomopathologie , Foie/effets des médicaments et des substances chimiques , Stress du réticulum endoplasmique/effets des médicaments et des substances chimiques , Rat Wistar , Stress oxydatif/effets des médicaments et des substances chimiques , Protéines associées aux microtubulesRÉSUMÉ
In a recent issue of Nature, Gomes et al.1 utilized structural, experimental, and computational biology to investigate the ligand-gated activation of BmGr9, an insect gustatory receptor specifically tuned to D-fructose. Together with two other studies published elsewhere, they are the first to describe how sugars bind to insect gustatory receptors.
Sujet(s)
Récepteurs de surface cellulaire , Animaux , Récepteurs de surface cellulaire/métabolisme , Récepteurs de surface cellulaire/composition chimique , Récepteurs couplés aux protéines G/métabolisme , Récepteurs couplés aux protéines G/composition chimique , Fructose/métabolisme , Fructose/composition chimique , Insectes/métabolisme , Ligands , Protéines d'insecte/métabolisme , Protéines d'insecte/composition chimique , GoûtRÉSUMÉ
Introducción: El hígado graso no alcohólico se enmarca en un grupo de patologías de etiología multifactorial, en el que la alimentación tendría un papel protagónico. En este sentido, el consumo de dietas ricas en fructosa, en especial a partir de fructosa añadida o jarabe de maíz alto en fructosa, ha sido motivo de investigación por su probable rol en la patogénesis de esta enfermedad. Metodología: Se realizó una búsqueda de artículos en relación con los efectos de las dietas ricas en fructosa sobre parámetros que podrían afectar la esteatosis hepática con el objetivo de organizar las principales evidencias al respecto. Resultados: Los estudios analizados tienden a evidenciar asociaciones positivas entre estas dietas y un mayor riesgo de desarrollar disbiosis intestinal, pérdida de integridad de la barrera intestinal y esteatosis hepática. Conclusiones: Los antecedentes recopilados en la presente revisión muestran evidencia de que este tipo de dietas favorecerían una serie de eventos que pueden conducir al hígado graso no alcohólico; por lo tanto, procurar un consumo adecuado de este monosacárido representaría una interesante alternativa de prevención para esta patología
Introduction: The non-alcoholic fatty liver disease falls within the group of multifactorial etiology pathologies in which food would play an important role. It is in this regard that the consumption of diets rich in fructose, especially from added fructose or corn syrup in fructose, has been a subject of investigation due to its likely roll in the pathogenesis of this disease. Methodology: A research for articles was performed about the effects of very rich fructose diets on parameters who could affect the liver steatosis in order to organize the main evidences. Results: The studies analized tend to report positive association between this diets and a higher risk of intestinal dysbiosis, intestinal barrier loss and partially with increased hepatic steatosis. Conclusions: The records compiled in the present review show evidence that this type of diets promote a serie of events that could result in non-alcoholic fatty liver disease so try a adequate consumption of this monosaccharides it would represent an interesting alternative to prevent this pathology
Sujet(s)
Sirop de maïs à haute teneur en fructose , Fructose , Dysbiose , Stéatose hépatique non alcooliqueRÉSUMÉ
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) in South Africa and Africa at large is considered a hidden threat. Our local population is burdened with increased metabolic risk factors for NAFLD. Our setting requires a reasonable approach to screen for and aid the diagnosis of NAFLD. OBJECTIVES: To investigate serum fructosamine and random spot urine fructose levels as biomarkers for the screening, diagnosis and monitoring of NAFLD. The primary objective of this study was to compare serum fructosamine and random spot urine fructose levels between groups with different levels of NAFLD severity as measured by ultrasound. A secondary objective was to determine the association, if any, between serum transaminases, the aspartate aminotransferase (AST) to platelet ratio index (APRI) score, serum fructosamine and urine fructose in different groups with steatosis. METHODS: Using a cross-sectional study design, 65 patients with three different levels of NAFLD, as detected by imaging, were enrolled. The primary exposures measured were serum fructosamine with random spot urine fructose, and secondary exposures were the serum transaminases (AST and alanine aminotransferase (ALT)) and the APRI score. Patients identified at the departments of gastroenterology, general internal medicine and diagnostic radiology were invited to participate. RESULTS: There were 38, 17 and 10 patients with mild, moderate and severe steatosis, respectively. There was no significant difference between the groups regarding serum fructosamine, measured as median (interquartile range): mild 257 (241 - 286) µmol/L, moderate 239 (230 - 280) µmol/L and severe 260 (221 - 341) µmol/L, p=0.5; or random spot urine fructose: mild 0.86 (0.51 - 1.30) mmol/L, moderate 0.84 (0.51 - 2.62) mmol/L and severe 0.71 (0.58 - 1.09) mmol/L, p = 0.8. ALT (U/L) differed between groups: mild 19 (12 - 27), moderate 27 (22 - 33), severe 27 (21 - 56), p=0.03, but not AST (U/L) (p=0.7) nor APRI (p=0.9). Urine fructose and ALT were correlated in the moderate to severe steatosis group (R=0.490, p<0.05), but not in the mild steatosis group. Serum fructosamine was associated with age in the mild steatosis group but not the moderate-severe steatosis group (R=0.42, p<0.01). CONCLUSION: Serum fructosamine and random spot urine fructose did not vary with the severity of NAFLD, indicating that they would not be useful biomarkers in this condition.
Sujet(s)
Alanine transaminase , Aspartate aminotransferases , Marqueurs biologiques , Fructosamine , Fructose , Stéatose hépatique non alcoolique , Indice de gravité de la maladie , Humains , Fructosamine/sang , Stéatose hépatique non alcoolique/urine , Stéatose hépatique non alcoolique/sang , Études transversales , Femelle , Fructose/urine , Mâle , Adulte d'âge moyen , Marqueurs biologiques/sang , Marqueurs biologiques/urine , Adulte , Aspartate aminotransferases/sang , Alanine transaminase/sang , République d'Afrique du Sud/épidémiologie , ÉchographieRÉSUMÉ
Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common cause of chronic liver-related morbidity and mortality. Though high fructose intake is acknowledged as a metabolic hazard, its role in the etiology of MASLD requires further clarification. Here, we demonstrated that high dietary fructose drives MASLD development and promotes MASLD progression in mice, and identified Usp2 as a fructose-responsive gene in the liver. Elevated USP2 levels were detected in the hepatocytes of MASLD mice; a similar increase was observed following fructose exposure in primary hepatocytes and mouse AML12 cells. Notably, hepatocytes overexpressing USP2 presented with exaggerated lipid accumulation and metabolic inflammation when exposed to fructose. Conversely, USP2 knockdown mitigated these fructose-induced changes. Furthermore, USP2 was found to activate the C/EBPα/11ß-HSD1 signaling, which further impacted the equilibrium of cortisol and cortisone in the circulation of mice. Collectively, our findings revealed the role of dietary fructose in MASLD pathogenesis and identified the USP2-mediated C/EBPα/ 11ß-HSD1 signaling as a potential target for the management of MASLD.
Sujet(s)
11-beta-Hydroxysteroid dehydrogenase type 1 , Fructose , Ubiquitin thiolesterase , Animaux , Souris , Fructose/effets indésirables , Ubiquitin thiolesterase/métabolisme , Ubiquitin thiolesterase/génétique , Mâle , 11-beta-Hydroxysteroid dehydrogenase type 1/métabolisme , 11-beta-Hydroxysteroid dehydrogenase type 1/génétique , Souris de lignée C57BL , Transduction du signal , Stéatose hépatique/métabolisme , Hépatocytes/métabolisme , Foie/métabolisme , Endopeptidases/métabolismeRÉSUMÉ
The effects of normal (NA) and controlled atmosphere (CA) storage and postharvest treatment with 1-methylcyclopropene (1-MCP) before CA storage for 5 months on the volatilome, biochemical composition and quality of 'Golden Delicious' (GD) and 'Red Delicious' (RD) apples were studied. Apples stored under NA and CA maintained and 1-MCP treatment increased firmness in both cultivars. NA storage resulted in a decrease of glucose, sucrose and fructose levels in both cultivars. When compared to CA storage, 1-MCP treatment caused a more significant decrease in sucrose levels and an increase in glucose levels. Additionally, 1-MCP-treated apples exhibited a significant decrease in malic acid content for both cultivars. All storage conditions led to significant changes in the abundance and composition of the volatilome in both cultivars. GD and RD apples responded differently to 1-MCP treatment compared to CA storage; higher abundance of hexanoate esters and (E,E)-α-farnesene was observed in RD apples treated with 1-MCP. While 1-MCP was effective in reducing (E,E)-α-farnesene abundance in GD apples, its impact on RD apples was more limited. However, for both cultivars, all storage conditions resulted in lower levels of 2-methylbutyl acetate, butyl acetate and hexyl acetate. The effectiveness of 1-MCP is cultivar dependent, with GD showing better results than RD.
Sujet(s)
Stockage des aliments , Malus , Malus/composition chimique , Malus/métabolisme , Cyclopropanes/pharmacologie , Composés organiques volatils/analyse , Composés organiques volatils/composition chimique , Fruit/composition chimique , Fruit/métabolisme , Saccharose/métabolisme , Malates , Sesquiterpènes/analyse , Glucose/métabolisme , Fructose/métabolisme , Fructose/analyseRÉSUMÉ
Enzymatic fructosylation has emerged as a strategy to enhance the hydrophilicity of polyphenols by introducing sugar moieties, leading to the development of phenolic glycosides, which exhibit improved solubility, stability, and biological activities compared to their non-glycosylated forms. This study provides a detailed analysis of the interactions between five phenolic fructosides (4MFPh, MFF, DFPh, MFPh, and MFPu) and twelve proteins (11ß-HS1, CRP, DPPIV, IRS, PPAR-γ, GK, AMPK, IR, GFAT, IL-1ß, IL-6, and TNF-α) associated with the pathogenesis of T2DM. The strongest interactions were observed for phlorizin fructosides (DFPh) with IR (-16.8 kcal/mol) and GFAT (-16.9 kcal/mol). MFPh with 11ß-HS1 (-13.99 kcal/mol) and GFAT (-12.55 kcal/mol). 4MFPh with GFAT (-11.79 kcal/mol) and IR (-12.11 kcal/mol). MFF with AMPK (-9.10 kcal/mol) and PPAR- γ (-9.71 kcal/mol), followed by puerarin and ferulic acid monofructosides. The fructoside group showed lower free energy binding values than the controls, metformin and sitagliptin. Hydrogen bonding (HB) was identified as the primary interaction mechanism, with specific polar amino acids such as serin, glutamine, glutamic acid, threonine, aspartic acid, and lysine identified as key contributors. ADMET results indicated favorable absorption and distribution characteristics of the fructosides. These findings provide valuable information for further exploration of phenolic fructosides as potential therapeutic agents for T2DM.
Sujet(s)
Hypoglycémiants , Hypoglycémiants/composition chimique , Hypoglycémiants/pharmacologie , Phénols/composition chimique , Phénols/pharmacologie , Humains , Simulation de docking moléculaire , Isoflavones/composition chimique , Isoflavones/métabolisme , Isoflavones/pharmacologie , Diabète de type 2/traitement médicamenteux , Diabète de type 2/métabolisme , Phloridzine/composition chimique , Phloridzine/pharmacologie , Fructose/composition chimique , Fructose/métabolisme , Glycosylation , Acides coumariques/composition chimique , Acides coumariques/métabolismeRÉSUMÉ
The interactions of different dietary doses of copper with fructose contribute to the development of metabolic dysfunction-associated steatotic liver disease (MASLD) via the gut-liver axis. The underlying mechanisms remain elusive. The aim of this study was to identify the specific pathways leading to gut barrier dysfunction in the ileum using a proteomics approach in a rat model. Male weanling Sprague Dawley rats were fed diets with adequate copper (CuA), marginal copper (CuM), or supplemented copper (CuS) in the absence or presence of fructose supplementation (CuAF, CuMF, and CuSF) for 4 weeks. Ileum protein was extracted and analyzed with an LC-MS. A total of 2847 differentially expressed proteins (DEPs) were identified and submitted to functional enrichment analysis. As a result, the ileum proteome and signaling pathways that were differentially altered were revealed. Of note, the CuAF is characterized by the enrichment of oxidative phosphorylation and ribosome as analyzed with the KEGG; the CuMF is characterized by an enriched arachidonic acid metabolism pathway; and focal adhesion, the regulation of the actin cytoskeleton, and tight junction were significantly enriched by the CuSF. In conclusion, our proteomics analysis identified the specific pathways in the ileum related to the different dietary doses of copper-fructose interactions, suggesting that distinct mechanisms in the gut are involved in the development of MASLD.
Sujet(s)
Cuivre , Fructose , Iléum , Foie , Protéomique , Rat Sprague-Dawley , Animaux , Fructose/administration et posologie , Fructose/effets indésirables , Mâle , Cuivre/métabolisme , Protéomique/méthodes , Iléum/métabolisme , Iléum/effets des médicaments et des substances chimiques , Foie/métabolisme , Foie/effets des médicaments et des substances chimiques , Rats , Régime alimentaire , Protéome/métabolisme , Transduction du signal/effets des médicaments et des substances chimiques , Stéatose hépatique non alcoolique/métabolisme , Stéatose hépatique non alcoolique/étiologie , Compléments alimentairesRÉSUMÉ
Carbohydrates are the main components of lentils, accounting for more than 60% of their composition. Their content is influenced by genetic factors, with different contents depending on the variety. These compounds have not only been linked to interesting health benefits, but they also have a significant influence on the techno-functional properties of lentil-derived products. In this study, the use of near-infrared spectroscopy (NIRS) to predict the concentration of total carbohydrate, fibre, starch, total sugars, fructose, sucrose and raffinose was investigated. For this purpose, six different cultivars of macrosperm (n = 37) and microsperm (n = 43) lentils have been analysed, the samples were recorded whole and ground and the suitability of both recording methods were compared. Different spectral and mathematical pre-treatments were evaluated before developing the calibration models using the Modified Partial Least Squares regression method, with a cross-validation and an external validation. The predictive models developed show excellent coefficients of determination (RSQ > 0.9) for the total sugars and fructose, sucrose, and raffinose. The recording of ground samples allowed for obtaining better models for the calibration of starch content (R > 0.8), total sugars and sucrose (R > 0.93), and raffinose (R > 0.91). The results obtained confirm that there is sufficient information in the NIRS spectral region for the development of predictive models for the quantification of the carbohydrate content in lentils.
Sujet(s)
Glucides , Lens , Spectroscopie proche infrarouge , Spectroscopie proche infrarouge/méthodes , Glucides/analyse , Glucides/composition chimique , Lens/composition chimique , Amidon/analyse , Amidon/composition chimique , Saccharose/analyse , Méthode des moindres carrés , Fructose/analyse , CalibrageRÉSUMÉ
Advanced glycation end products (AGEs) play an important role in the pathogenesis of age-linked disorders and diabetes mellitus. The aim of this study was to assess the repurposing potential of Phloroglucinol (PHL the antispasmodic drug), as an anti-glycation agent using Fructose-BSA model. The ability of PHL to inhibit AGE formation was evaluated using AGEs formation (Intrinsic fluorescence), fructosamine adduct (NBT) and free lysine availability (TNBSA) assays. The BSA protein conformation was assessed through Thioflavin-T, Congo-Red and Circular Dichroism assays. The lysine blockade and carbonyl entrapment were explored as possible mode of action. Our data showed that PHL significantly decreased the formation of AGEs with an IC50 value of 0.3mM. The fructosamine adducts and free lysine load was found to be reduced. Additionally, the BSA conformation was preserved by PHL. Mechanistic assays did not reveal involvement of lysine blockade as underlying reason for reduction in AGEs load. This was also supported by computational data whereby PHL failed to engage any catalytic residue involved in early fructose-BSA interaction. However, it was found to entrap the carbonyl moieties. In conclusion, the PHL demonstrated anti-glycation potential, which can be attributed to its ability to entrap carbonyl intermediates. Hence, the clinically available antispasmodic drug, presents itself as a promising candidate to be repurposed as anti-glycation agent.
Sujet(s)
Produits terminaux de glycation avancée , Phloroglucinol , Sérumalbumine bovine , Produits terminaux de glycation avancée/métabolisme , Sérumalbumine bovine/composition chimique , Sérumalbumine bovine/métabolisme , Phloroglucinol/pharmacologie , Phloroglucinol/composition chimique , Glycosylation/effets des médicaments et des substances chimiques , Lysine/métabolisme , Lysine/composition chimique , Fructose/composition chimique , Fructose/métabolisme , Animaux , Fructosamine/métabolisme , Simulation de docking moléculaire , BovinsRÉSUMÉ
BACKGROUND: D-psicose 3-epimerase (DPEase) is a potential catalytic enzyme for D-psicose production. D-psicose, also known as D-allulose, is a low-calorie sweetener that has gained considerable attention as a healthy alternative sweetener due to its notable physicochemical properties. This research focused on an in-depth investigation of the expression of the constructed DPEase gene from Agrobacterium tumefaciens in Escherichia coli for D-psicose synthesis. Experimentally, this research created the recombinant enzyme, explored the optimization of gene expression systems and protein purification strategies, investigated the enzymatic characterization, and then optimized the D-psicose production. Finally, the produced D-psicose syrup underwent acute toxicity evaluation to provide scientific evidence supporting its safety. RESULTS: The optimization of DPEase expression involved the utilization of Mn2+ as a cofactor, fine-tuning isopropyl ß-D-1-thiogalactopyranoside induction, and controlling the induction temperature. The purification process was strategically designed by a nickel column and an elution buffer containing 200 mM imidazole, resulting in purified DPEase with a notable 21.03-fold increase in specific activity compared to the crude extract. The optimum D-psicose conversion conditions were at pH 7.5 and 55 °C with a final concentration of 10 mM Mn2+ addition using purified DPEase to achieve the highest D-psicose concentration of 5.60% (w/v) using 25% (w/v) of fructose concentration with a conversion rate of 22.42%. Kinetic parameters of the purified DPEase were Vmax and Km values of 28.01 mM/min and 110 mM, respectively, which demonstrated the high substrate affinity and efficiency of DPEase conversion by the binding site of the fructose-DPEase-Mn2+ structure. Strategies for maintaining stability of DPEase activity were glycerol addition and storage at -20 °C. Based on the results from the acute toxicity study, there was no toxicity to rats, supporting the safety of the mixed D-fructose-D-psicose syrup produced using recombinant DPEase. CONCLUSIONS: These findings have direct and practical implications for the industrial-scale production of D-psicose, a valuable rare sugar with a broad range of applications in the food and pharmaceutical industries. This research should advance the understanding of DPEase biocatalysis and offers a roadmap for the successful scale-up production of rare sugars, opening new avenues for their utilization in various industrial processes.
Sujet(s)
Escherichia coli , Fructose , Protéines recombinantes , Protéines recombinantes/biosynthèse , Protéines recombinantes/isolement et purification , Protéines recombinantes/métabolisme , Fructose/métabolisme , Escherichia coli/génétique , Escherichia coli/métabolisme , Agrobacterium tumefaciens , Carbohydrate epimerases/génétique , Carbohydrate epimerases/métabolisme , Carbohydrate epimerases/isolement et purification , Animaux , Racémases et épimérases/métabolisme , Racémases et épimérases/génétique , Rats , Protéines bactériennes/génétique , Protéines bactériennes/métabolismeRÉSUMÉ
Prescriptions for antiseizure medications (ASMs) have been rapidly growing over the last several decades due, in part, to an expanding list of clinical indications for which they are now prescribed. This trend has raised concern for potential adverse neurodevelopmental outcomes in ASM-exposed pregnancies. Recent large scale population studies have suggested that the use of topiramate (TOPAMAX, Janssen-Cilag), when prescribed for seizure control, migraines, and/or weight management, is associated with an increased risk for autism spectrum disorder (ASD), intellectual disability, and attention-deficit/hyperactivity disorder (ADHD) in exposed offspring. Here, we critically review epidemiologic evidence demonstrating the neurobehavioral teratogenicity of topiramate and speculate on the neuromolecular mechanisms by which prenatal exposure may perturb neurocognitive development. Specifically, we explore the potential role of topiramate's pharmacological interactions with ligand- and voltage-gated ion channels, especially GABAergic signaling, its effects on DNA methylation and histone acetylation, whether topiramate induces oxidative stress, and its association with fetal growth restriction as possible mechanisms contributing to neurodevelopmental toxicity. Resolving this biology will be necessary to reduce the risk of adverse pregnancy outcomes caused by topiramate or other ASMs.
Sujet(s)
Anticonvulsivants , Topiramate , Topiramate/toxicité , Humains , Grossesse , Anticonvulsivants/toxicité , Femelle , Effets différés de l'exposition prénatale à des facteurs de risque , Troubles du développement neurologique/induit chimiquement , Animaux , Fructose/analogues et dérivés , Fructose/toxicitéRÉSUMÉ
The isomerization of glucose is a crucial step for biomass valorization to downstream chemicals. Herein, highly dispersed MgO doped biochar (BM-0.5@450) was prepared from rice straw via a solvent-free ball milling pretreatment and pyrolysis under nitrogen conditions. The nano-MgO doped biochar demonstrated enhanced conversion of glucose in water at low temperatures. A 31 % yield of fructose was obtained from glucose over BM-0.5@450 at 50 °C with 80.0 % selectivity. At 60 °C for 140 min, BM-0.5@450 achieved a 32.5 % yield of fructose. Compared to catalyst synthesized from conventional impregnation method (IM@450), the BM-0.5@450 catalyst shows much higher fructose yields (32.5 % vs 25.9 %), which can be attributed to smaller crystallite size of MgO (11.32 nm vs 19.58 nm) and homogenous distribution. The mechanism study shows that the activated MgOH+·OH- group by water facilitated the deprotonation process leading to the formation of key intermediate enediol.
Sujet(s)
Charbon de bois , Glucose , Oxyde de magnésium , Charbon de bois/composition chimique , Oxyde de magnésium/composition chimique , Glucose/composition chimique , Isomérie , Catalyse , Oryza/composition chimique , Fructose/composition chimique , Basse température , TempératureRÉSUMÉ
BACKGROUND: The black/white heart disease mortality disparity began increasing in the early 1980's, coincident with the switch from sucrose to high-fructose-corn-syrup/(HFCS) in the US food supply. There has been more fructose in HFCS than generally-recognized-as-safe/GRAS, which has contributed to unprecedented excess-free-fructose/(unpaired-fructose) in foods/beverages. Average- per-capita excess-free-fructose, from HFCS, began exceeding dosages/(5-10 g) that trigger fructose-malabsorption in the early 1980's. Fructose malabsorption contributes to gut-dysbiosis and gut-in-situ-fructosylation of dietary peptides/incretins/(GLP-1/GIP) which forms atherosclerotic advanced-glycation-end-products. Both dysregulate gut endocrine function and are risk factors for cardiovascular disease/(CVD). Limited research shows that African Americans have higher fructose malabsorption prevalence than others. CVD risk begins early in life. METHODS: Coronary-Artery-Risk-Development-in-Adults/(CARDIA) study data beginning in 1985-86 with 2186 Black and 2277 White participants, aged 18-30 y, were used to test the hypothesis that HFCS sweetened beverage intake increases CVD risk/incidence, more among Black than White young adults, and at lower intakes; while orange juice-a low excess-free-fructose juice with comparable total sugars and total fructose, but a 1:1 fructose-to-glucose-ratio, i.e., low excess-free-fructose, does not. Cox proportional hazards models were used to calculate hazard ratios. RESULTS: HFCS sweetened beverage intake was associated with higher CVD risk (HR = 1.7) than smoking (HR = 1.6). CVD risk was higher at lower HFCS sweetened beverage intake among Black than White participants. Intake, as low as 3 times/wk, was associated with twice the CVD risk vs. less frequent/never, among Black participants only (HR 2.1, 95% CI 1.2-3.7; P = 0.013). Probability of an ordered relationship approached significance. Among Black participants, CVD incidence jumped 62% from 59.8/1000, among ≤ 2-times/wk, to 96.9/1000 among 3-6 times/wk consumers. Among White participants, CVD incidence increased from 37.6/1000, among ≤ 1.5-times/wk, to 41.1/1000, among 2 times/wk-once/d - a 9% increase. Hypertension was highest among Black daily HFCS sweetened beverage consumers. CONCLUSION: The ubiquitous presence of HFCS over-the-past-40 years, at higher fructose-to-glucose ratios than generally-recognized-as-safe, may have contributed to CVD racial disparities, due to higher fructose-malabsorption prevalence among Black individuals, unpaired/excess-free-fructose induced gut dysbiosis and gut fructosylation of dietary peptides/incretins (GLP-1/GIP). These disturbances contribute to atherosclerotic plaque; promote incretin insufficiency/dysregulation/altered satiety/dysglycemia; decrease protective microbiota metabolites; and increase hypertension, CVD morbidity and mortality.
Sujet(s)
, Maladies cardiovasculaires , Sirop de maïs à haute teneur en fructose , Humains , Mâle , Maladies cardiovasculaires/épidémiologie , Sirop de maïs à haute teneur en fructose/effets indésirables , /statistiques et données numériques , Adulte , Femelle , Incidence , Jeune adulte , États-Unis/épidémiologie , Adolescent , Boissons édulcorées au sucre/effets indésirables , Boissons édulcorées au sucre/statistiques et données numériques , Facteurs de risque , Fructose/effets indésirables , Fructose/administration et posologie , Édulcorants/effets indésirablesRÉSUMÉ
Liamocins are molecules with a polyol lipid structure produced by rare strains of Aureobasidium pullulans. In recent years, liamocins have attracted attention due to their antibacterial, anticancer and surface-active properties, and promising potential applications have been identified in the food, agriculture, medical and pharmaceutical industries. This study is the first to investigate the effects of different carbon and nitrogen sources on the growth and liamocin production kinetics of A. pullulans NBRC 100716 strain. This strain was selected among six different A. pullulans strains whose liamocin productions were tested by us for the first time. In fermentations carried out in shaking water baths, the carbon source that most supported the liamocin production of this strain was fructose, and the nitrogen source was peptone-yeast extract combination. In the medium containing fructose and the peptone-yeast extract mixture, A. pullulans NBRC 100716 produced 4.26 g liamocin L-1. The specific liamocin production rate (qp) of the strain in this medium was 0.0090 g liamocin/g mo.h. This study is also the first to produce liamocin with a fructophilic A. pullulans strain. Present findings in this research also demonstrated the excellent biosurfactant capacity of the liamocin produced by this strain. The obtained liamocin reduced the water surface tension to a degree that can compete with synthetic surfactants. Furthermore, this is the first report to reveal that the fatty acid profile of liamocin obtained from A. pullulans NBRC 100716 contains an appreciable amount of unsaturated fatty acids and is similar to the composition of vegetable oil.
Sujet(s)
Aureobasidium (genre) , Carbone , Milieux de culture , Fermentation , Azote , Azote/métabolisme , Carbone/métabolisme , Milieux de culture/composition chimique , Aureobasidium (genre)/métabolisme , Cinétique , Fructose/métabolismeRÉSUMÉ
BACKGROUND Measurement of bite force plays a crucial role in assessment of the masticatory system. With a growing interest in detecting occlusal irregularities, bite force sensors have garnered attention in the biomedical field. This study aimed to introduce a hydrogel bite force sensor, based on hydroxyethyl-cellulose-fructose-water (HEC-F-water), for premolar and molar teeth, and to evaluate it using optical profilometry, infrared spectroscopy (FTIR), and Instron Tension testing system, with 2.5 cm (1 inch) margins at top, bottom, right, and left. MATERIAL AND METHODS We fabricated 20 HEC-F-water hydrogel samples sized with surface of 1×1 cm, with 2 different widths - 1 mm and 5 mm. The samples were characterized using optical profilometry and FTIR and their electrical characteristics were determined using an impedance analyzer. Aluminum (Al) electrodes, fabricated using Cutting Plotter, were used to form a HEC-F-water-based transducer, which was used for bite force sensing. The Instron tensile testing system was employed, utilizing 3D printed models of the upper and lower jaw, to simulate biting. Forces in the range between 40 N and 540 N were exerted upon the transducer, and the output change in the electrical signal was measured. RESULTS The study determined the transfer function between bite force and capacitance. The fabricated sensor exhibited a sensitivity of 3.98 pF/N, an input range of 500 N, output range of 2 nF, and accuracy of 95.9%. CONCLUSIONS This study introduces an edible bite force sensor employing an edible hydrogel as a dielectric, presenting a novel avenue in the development of edible sensorics in dentistry.
Sujet(s)
Force occlusale , Humains , Hydrogels/composition chimique , Molaire , Fructose , Mastication/physiologie , Spectroscopie infrarouge à transformée de Fourier/méthodes , Cellulose/composition chimique , Eau , PrémolaireRÉSUMÉ
Hereditary fructose intolerance (HFI) is a painful and potentially lethal genetic disease caused by a mutation in aldolase B resulting in accumulation of fructose-1-phosphate (F1P). No cure exists for HFI and treatment is limited to avoid exposure to fructose and sugar. Using aldolase B deficient mice, here we identify a yet unrecognized metabolic event activated in HFI and associated with the progression of the disease. Besides the accumulation of F1P, here we show that the activation of the purine degradation pathway is a common feature in aldolase B deficient mice exposed to fructose. The purine degradation pathway is a metabolic route initiated by adenosine monophosphate deaminase 2 (AMPD2) that regulates overall energy balance. We demonstrate that very low amounts of fructose are sufficient to activate AMPD2 in these mice via a phosphate trap. While blocking AMPD2 do not impact F1P accumulation and the risk of hypoglycemia, its deletion in hepatocytes markedly improves the metabolic dysregulation induced by fructose and corrects fat and glycogen storage while significantly increasing the voluntary tolerance of these mice to fructose. In summary, we provide evidence for a critical pathway activated in HFI that could be targeted to improve the metabolic consequences associated with fructose consumption.