RESUMEN

Panax ginseng C. A. Meyer (ginseng) is a medicinal plant widely used for promoting longevity. Recently, homogalacturonan (HG) domain-rich pectins purified from some plants have been reported to have anti-aging-related activities, leading us to explore the longevity-promoting activity of the HG pectins from ginseng. In this study, we discovered that two of low methyl-esterified ginseng HG pectins (named as WGPA-2-HG and WGPA-3-HG), whose degree of methyl-esterification (DM) was 16 % and 8 % respectively, promoted longevity in Caenorhabditis elegans. Results showed that WGPA-2-HG/WGPA-3-HG impaired insulin/insulin-like growth factor 1 (IGF-1) signalling (IIS) pathway, thereby increasing the nuclear accumulation of transcription factors SKN-1/Nrf2 and DAF-16/FOXO and enhancing the expression of relevant anti-aging genes. BLI and ITC analysis showed that the insulin-receptor binding, the first step to activate IIS pathway, was impeded by the engagement of WGPA-2-HG/WGPA-3-HG with insulin. By chemical modifications, we found that high methyl-esterification of WGPA-2-HG/WGPA-3-HG was detrimental for their longevity-promoting activity. These findings provided novel insight into the precise molecular mechanism for the longevity-promoting effect of ginseng pectins, and suggested a potential to utilize the ginseng HG pectins with appropriate DM values as natural nutrients for increasing human longevity.

Asunto(s)

Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Factor I del Crecimiento Similar a la Insulina , Insulina , Longevidad , Panax , Pectinas , Transducción de Señal , Animales , Caenorhabditis elegans/efectos de los fármacos , Caenorhabditis elegans/metabolismo , Panax/química , Factor I del Crecimiento Similar a la Insulina/metabolismo , Pectinas/farmacología , Pectinas/metabolismo , Pectinas/química , Longevidad/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Insulina/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Esterificación

RESUMEN

The objectives of this study were to elucidate the effects of degree of methyl esterification (DM) and charge distribution of pectin on the stability of emulsions and to analyze bioaccessibility of curcumin incorporated in emulsions stabilized by pectins. Three commercial pectins, CP72 (DM72), CP50 (DM50), and CP7 (DM7), were used. MP50 (DM50) with consecutive demethylesterified galacturonic acid residues was prepared from CP72 via demethylesterification to induce different charge distributions. Emulsions containing curcumin were prepared and were stored for 30 days. The CP72 and CP50 emulsions remained relatively stable for 30 days. However, MP50 and CP7 were less effective at forming stable emulsions. When the pectin emulsions passed through each phase of the simulated gastrointestinal tract (GIT), the CP72 and CP50 emulsions retained their initial droplet structures after in vitro mouth and gastric digestion, whereas the MP50 and CP7 emulsions exhibited gel-like clusters, although the gel-like formation of MP50 was distinct from that observed in CP7. MP50 emulsion showed a high degree of final lipid digestion and high bioaccessibility of curcumin while CP72 emulsion displayed a low degree of final lipid digestion. CP50 exhibited low bioaccessibility of curcumin, which might have been contributed by its fast lipid digestion profiles.

RESUMEN

2,2,6,6-Tetramethylpiperidine-1-oxyl radical (TEMPO)-catalytic oxidation was applied to a water-insoluble α-(1 â†’ 3)-glucan in water at pH 10 and room temperature (∼24 °C), with solid NaOCl·5H2O as the primary oxidant. Oxidation with NaOCl at 15 mmol/g gave a water-soluble TEMPO-oxidized product at a mass recovery ratio of 97 %. The carboxy content of the TEMPO-oxidized product was 5.3 mmol/g, which corresponds to a degree of C6-oxidation (DO) of 93 %. A new water-soluble α-(1 â†’ 3)-polyglucuronic acid with a nearly homogeneous chemical structure was therefore quantitatively obtained. X-ray diffraction and solid-state 13C NMR spectroscopic analyses showed that the original α-(1 â†’ 3)-glucan and its TEMPO-oxidized product with a carboxy content of 5.3 mmol/g had crystalline structures, whereas the oxidized products with DOs of 50 % and 66 % had almost disordered structures. The carboxy groups in the oxidized products were regioselectively methyl esterified with trimethylsilyl diazomethane, and analyzed by using size-exclusion chromatography with multi-angle laser-light scattering and refractive index detections. The results show that the original α-(1 â†’ 3)-glucan and its oxidized products with DOs of 50 %, 66 %, and 93 % had weight-average degrees of polymerization of 671, 288, 54, and 45, respectively. Substantial depolymerization of the α-(1 â†’ 3)-glucan molecules therefore occurred during catalytic oxidation, irrespective of the oxidation pH.

RESUMEN

Pectin, predominantly present within plant cell walls, is a dietary fiber that potentially induces distinct health effects depending on its molecular structure. Such structure-dependent health effects of pectin-derived galacturonic acid oligosaccharides (GalA-OS) are yet largely unknown. This study describes the influence of methyl-esterification and ∆4,5-unsaturation of GalA-OS through defined sets of GalA-OS made from pectin using defined pectinases, on the fermentability by individual fecal inocula. The metabolite production, OS utilization, quantity and size, methyl-esterification and saturation of remaining GalA-OS were monitored during the fermentation of GalA-OS. Fermentation of all GalA-OS predominantly induced the production of acetate, butyrate and propionate. Metabolization of unsaturated GalA-OS (uGalA-OS) significantly increased butyrate formation compared to saturated GalA-OS (satGalA-OS), while satGalA-OS significantly increased propionate formation. Absence of methyl-esters within GalA-OS improved substrate metabolization during the first 18 h of fermentation (99 %) compared to their esterified analogues (51 %). Furthermore, HPAEC and HILIC-LC-MS revealed accumulation of specific methyl-esterified GalA-OS, confirming that methyl-esterification delays fermentation. Fermentation of structurally distinct GalA-OS results in donor specific microbiota composition with uGalA-OS specifically stimulating the butyrate-producer Clostridium Butyricum. This study concludes that GalA-OS fermentation induces highly structure-dependent changes in the gut microbiota, further expanding their potential use as prebiotics.

Asunto(s)

Pectinas , Propionatos , Fermentación , Pectinas/química , Oligosacáridos/química , Heces , Butiratos

RESUMEN

Common smut caused by Ustilago maydis is one of the dominant fungal diseases in plants. The resistance mechanism to U. maydis infection involving alterations in the cell wall is poorly studied. In this study, the resistant single segment substitution line (SSSL) R445 and its susceptible recurrent parent line Ye478 of maize were infected with U. maydis, and the changes in cell wall components and structure were studied at 0, 2, 4, 8, and 12 days postinfection. In R445 and Ye478, the contents of cellulose, hemicellulose, pectin, and lignin increased by varying degrees, and pectin methylesterase (PME) activity increased. The changes in hemicellulose and pectin in the cell wall after U. maydis infection were analyzed via immunolabeling using monoclonal antibodies against hemicellulsic xylans and high/low-methylated pectin. U. maydis infection altered methyl esterification of pectin, and the degree of methyl esterification was correlated with the resistance of maize to U. maydis. Furthermore, the relationship between methyl esterification of pectin and host resistance was validated using 15 maize inbred lines with different resistance levels. The results revealed that cell wall components, particularly pectin, were important factors affecting the colonization and propagation of U. maydis in maize, and methyl esterification of pectin played a role in the resistance of maize to U. maydis infection.

Asunto(s)

Enfermedades de las Plantas , Ustilago , Enfermedades de las Plantas/microbiología , Esterificación , Zea mays/metabolismo , Pectinas/metabolismo , Ustilago/metabolismo , Pared Celular/metabolismo

RESUMEN

Inflammatory bowel disease (IBD) is a public health challenge and the use of pectin for symptom amelioration is a promising option. In this work, sunflower pectin has been extracted without (CHP) and with assistance of ultrasound (USP) using sodium citrate as a food-grade extracting agent. At optimal conditions (64 °C, 23 min) the highest yield was obtained with ultrasound application (15.5 vs. 8.1 %). Both pectins were structurally characterized by 1H NMR, HPSEC-ELSD, FT-IR and GC-FID. Unlike CHP, USP showed a lower molecular weight, higher galacturonic acid, lower degree of methyl-esterification and, overall, higher viscosity. These characteristics could affect the anti-inflammatory activity of pectins, evaluated using DSS-induced IBD model mice. So, USP promoted the defence (ICAM-1) and repair of the gastrointestinal mucosa (TFF3, ZO-1) more effectively than CHP. These results demonstrate the potential amelioration of acute colitis in IBD mice through USP supplementation. Taking into account the biomarkers analysed, these results demonstrate, for the first time, the positive impact of sunflower pectin extracted by ultrasound under very soft conditions on inflammatory bowel disease that might open up new possibilities in the treatment of this serious pathology.

Asunto(s)

Helianthus , Enfermedades Inflamatorias del Intestino , Animales , Ratones , Pectinas/farmacología , Pectinas/química , Helianthus/química , Espectroscopía Infrarroja por Transformada de Fourier , Citrato de Sodio , Enfermedades Inflamatorias del Intestino/diagnóstico por imagen , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico

RESUMEN

The aim of this study is to report the preparation of pectin microspheres by varying degrees of methyl esterification (DM) cross-linked with divalent cationic calcium to encapsulate Lactiplantibacillus plantarum STB1 and L. plantarum LJ1, respectively. Scanning electron microscopy revealed the compact and smooth surface of pectin of DM 28 %, and the stochastic distribution of L. plantarum throughout the gel reticulation. And the pectin of DM 28 % considerably increased probiotics tolerance after continuous exposure to stimulated gastrointestinal tract conditions, with viable counts exceeding 109 CFU/mL. This data indicated that low methoxy-esterification pectin was more efficient to improve the targeted delivery of probiotics in GIT. Additionally, the controlled release of microspheres was dependent on various pH levels. At pH 7.4, the release rates of L. plantarum STB1 and L. plantarum LJ1 reached up to 97.63 % and 95.33 %, respectively. Finally, the Caco-2 cell adhesion model was used to evaluate the cell adhesion rate after encapsulation, which exhibited better adhesion at DM of 60 %.

Asunto(s)

Lactobacillus plantarum , Probióticos , Humanos , Pectinas/farmacología , Pectinas/metabolismo , Esterificación , Preparaciones de Acción Retardada/metabolismo , Microesferas , Células CACO-2 , Colon/metabolismo , Lactobacillus plantarum/metabolismo

RESUMEN

The structural and functional properties of two different pea water-soluble polysaccharides, a high methyl-esterified (HM-SPPS; degree of methyl esterification (DMe): 71.0 %) and low methyl-esterified SPPS (LM-SPPS; DMe: 25.2 %) were investigated. The two extracts did not vary in composition and showed a weight average molecular mass of about 1,000 kDa, as measured by size exclusion chromatography equipped with a multi-angle light scattering detector. Both HM-SPPS and LM-SPPS had similar sugar compositions, with arabinose 42.2-47.1 %, glucose 26.6-31.0 %, and galacturonic acid 17.5-18.0 %, as their main sugars. Their charge varied as a function of pH. The molecular structure was observed by a scanning probe microscope and showed a straight chain structure with small branches. The structure was similar to that already reported for polysaccharides from kidney bean. SPPS molecules interact with acidified milk protein particles at pH < 4.4. There were differences between the two SPPS. LM-SPPS could stabilize a model acidified milk dispersion with minimal aggregation between pH 3.6-4.4, while HM-SPPS showed the presence of bridging flocculation caused by polysaccharide's entanglements. It was concluded that SPPS stabilizes acidified protein by steric and electrostatic repulsion.

Asunto(s)

Proteínas de la Leche , Pisum sativum , Animales , Estructura Molecular , Polisacáridos , Leche

RESUMEN

Introduction: GoSAMTs play a role in the methylation of polysaccharides synthesized by the Golgi. Pectin homogalacturonan (HG) methyl-esterification is essential for the proper function of this polysaccharide in cell walls. In order to better understand the role of GoSAMTs in HG biosynthesis, we analyzed mucilage methyl-esterification in gosamt mutants. Methods: To determine the function of GoSAMT1 and GoSAMT2 in HG methyl-esterification we utilized epidermal cells of seed coats, as these structures produce mucilage, which is a pectic matrix. We evaluated differences in seed surface morphology and quantified mucilage release. We measured methanol release, and used antibodies and confocal microscopy to analyze HG methyl-esterification in mucilage. Results: We observed morphological differences on the seed surface and delayed, uneven mucilage release in gosamt1-1gosamt2-1 double mutants. We also found changes in the distal wall length indicating abnormal cell wall breakage in this double mutant. Using methanol release and immunolabeling, we confirmed that GoSAMT1 and GoSAMT2 are involved in HG methyl-esterification in mucilage. However, we did not find evidence of decreasing HG in the gosamt mutants. Confocal microscopy analyses detected different patterns in the adherent mucilage and a greater number of low-methyl-esterified domains near the seed coat surface, which correlates with a greater number of "egg-box" structures in this region. We also detected a shift in the partitioning between the Rhamnogalacturonan-I soluble and adherent layers of the double mutant, which correlated with increased amounts of arabinose and arabinogalactan-protein in the adherent mucilage. Discussion: The results show that the HG synthesized in gosamt mutant plants is less methyl esterified, resulting in more egg-box structures, which stiffen the cell walls in epidermal cells and change the rheological properties of the seed surface. The increased amounts of arabinose and arabinogalactan-protein in adherent mucilage, also suggests that compensation mechanisms were triggered in the gosamt mutants.

RESUMEN

O-Acetyl esterification is an important structural and functional feature of pectins present in the cell walls of all land plants. The amount and positions of pectin acetyl substituents varies across plant tissues and stages of development. Plant growth and response to biotic and abiotic stress are known to be significantly influenced by pectin O-acetylation. Gel formation is a key characteristic of pectins, and many studies have shown that gel formation is dependent upon the degree of acetylation. Previous studies have indicated that members of the TRICHOME BIREFRINGENCE-LIKE (TBL) family may play a role in the O-acetylation of pectin, however, biochemical evidence for acceptor specific pectin acetyltransferase activity remains to be confirmed and the exact mechanism(s) for catalysis must be determined. Pectin acetylesterases (PAEs) affect pectin acetylation as they hydrolyze acetylester bonds and have a role in the amount and distribution of O-acetylation. Several mutant studies suggest the critical role of pectin O-acetylation; however, additional research is required to fully understand this. This review aims to discuss the importance, role, and putative mechanism of pectin O-acetylation.

RESUMEN

Homogalacturonan (HG)-type pectins are nutrient components in plants and are widely used in the food industry. The methyl-esterification pattern is a crucial structural parameter used to assess HG pectins in terms of their nutraceutical activity. To better understand the methyl-esterification pattern of natural HG pectins from different plants, we purified twenty HG pectin-rich fractions from twelve plants and classified them by their monosaccharide composition, Fourier transform-infrared spectroscopy (FT-IR) signatures, and NMR analysis. FT-IR shows that these HG pectins are all minimally esterified, with the degree of methyl-esterification (DM) being 5 to 40%. To examine their methyl-esterification pattern by enzymatic fingerprinting, we hydrolyzed the HG pectins using endo-polygalacturonase. Hydrolyzed oligomers were derivatized with 2-aminobenzamide and subjected to liquid chromatography-fluorescence-tandem mass spectrometry (HILIC-FLR-MSn). Twenty-one types of mono-/oligo-galacturonides having DP values of 1-10 were found to contain nonesterified monomers, dimers, and trimers, as well as oligomers with 1 to 6 methyl-ester groups. In these oligo-galacturonides, MSn analysis demonstrated that the number of methyl-ester groups in the continuous sequence was 2 to 5. Mono- and di-esterified oligomers had higher percentages in total methyl-esterified groups, suggesting that these are a random methyl-esterification pattern in these HG pectins. Our study analyzes the characteristics of the methyl-esterification pattern in naturally occurring plant-derived HG pectins and findings that will be useful for further studying HG structure-function relationships.

RESUMEN

A homogalacturonan (HG) FPLP obtained from Ficus pumila L. was reported to have anti-diabetic activity but how this is influenced by degree of methyl-esterification (DM) of HG is unknown. To comprehensively analyze the role of DM in hypoglycemic activity in insulin-resistant HepG2 cells, HG derivatives (0 < DM < 100) were prepared from FPLP (DM25) by alkali or methanol acidified with acetyl chloride. Interestingly, a quadratic curve relationship revealed that hypoglycemic effect increased and then decreased with DM, and which was the most pronounced with DM54. DM might regulate activity by altering the intracellular drug concentration through cellular uptake. Furthermore, HG-DMn (0 < n < 100) were dependent on macropinocytosis, while HG-DMn (30 < n < 100) were also dependent on caveolae-mediated endocytosis. For HG, higher lipophilicity, smaller particle size, and more endocytosis mechanisms involved were favorable for cellular uptake, thereby increasing the intracellular drug concentration and enhancing the hypoglycemic activity. This work provides ideas for future investigations on structure-activity relationships.

Asunto(s)

Ésteres , Hipoglucemiantes , Ésteres/farmacología , Células Hep G2 , Humanos , Hipoglucemiantes/farmacología , Pectinas/farmacología

RESUMEN

Pectins are dietary fibres that modulate T cell immunity, microbiota composition, and fermentation profiles, but how this is influenced by the degree of methyl-esterification (DM) and degree-of-blockiness (DB) of pectin is unknown. Here, we demonstrate that supplementation of DM19(high-DB), DM49(low-DB) and DM43(high-DB) pectins at a low dose increased the frequencies of intestinal T-helper (Th)1 and Th2 cells after 1 week of pectin supplementation in mice, whereas DM18(low-DB) did not. After 4 weeks of supplementation with those pectins, Th1 and Th2 frequencies returned to control levels, whereas Rorγt+ regulatory T-cell frequencies increased. These structure-dependent effects could derive from induced shifts in microbiota composition that differed between DM18(low-DB) pectin and the other pectins. T-cell-modulating effects were not short-chain-fatty acid-dependent, but rather through an increase in Aryl-hydrocarbon-receptor-activating components. Thus, pectins with a specific combination of DM and DB have an impact on intestinal T cell-immunity in mice, when supplemented at a low dose.

Asunto(s)

Microbiota , Pectinas , Animales , Fibras de la Dieta , Ésteres , Intestinos , Ratones , Pectinas/farmacología

RESUMEN

INTRODUCTION: Pectins have anti-inflammatory properties on intestinal immunity through direct interactions on Toll-like receptors (TLRs) in the small intestine or via stimulating microbiota-dependent effects in the large intestine. Both the degree of methyl-esterification (DM) and the distribution of methyl-esters (degree of blockiness; DB) of pectins contribute to this influence on immunity, but whether and how the DB impacts immunity through microbiota-dependent effects in the large intestine is unknown. Therefore, this study tests pectins that structurally differ in DB in a mouse model with Citrobacter rodentium induced colitis and studies the impact on the intestinal microbiota composition and associated attenuation of inflammation. METHODS AND RESULTS: Both low and high DB pectins induce a more rich and diverse microbiota composition. These pectins also lower the bacterial load of C. rodentium in cecal digesta. Through these effects, both low and high DB pectins attenuate C. rodentium induced colitis resulting in reduced intestinal damage, reduced numbers of Th1-cells, which are increased in case of C. rodentium induced colitis, and reduced levels of GATA3+ Tregs, which are related to tissue inflammation. CONCLUSION: Pectins prevent C. rodentium induced colonic inflammation by lowering the C. rodentium load in the caecum independently of the DB.

Asunto(s)

Colitis/tratamiento farmacológico , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Pectinas/química , Pectinas/farmacología , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/farmacología , Ciego/efectos de los fármacos , Ciego/metabolismo , Citrobacter rodentium/patogenicidad , Citrus sinensis/química , Colitis/microbiología , Colitis/patología , Citocinas/metabolismo , Infecciones por Enterobacteriaceae/patología , Ésteres/química , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/genética , Ratones Endogámicos C57BL , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/patología

RESUMEN

SCOPE: Intestinal mucositis is a common side effect of the chemotherapeutic agent doxorubicin, which is characterized by severe Toll-like receptor (TLR) 2-mediated inflammation. The dietary fiber pectin is shown to prevent this intestinal inflammation through direct inhibition of TLR2 in a microbiota-independent manner. Recent in vitro studies show that inhibition of TLR2 is determined by the number and distribution of methyl-esters of pectins. Therefore, it is hypothesized that the degree of methyl-esterification (DM) and the degree of blockiness (DB) of pectins determine attenuating efficacy on doxorubicin-induced intestinal mucositis. METHODS AND RESULTS: Four structurally different pectins that differed in DM and DB are tested on inhibitory effects on murine TLR2 in vitro, and on doxorubicin-induced intestinal mucositis in mice. These data demonstrate that low DM pectins or intermediate DM pectins with high DB have the strongest inhibitory impact on murine TLR2-1 and the strongest attenuating effect on TLR2-induced apoptosis and peritonitis. Intermediate DM pectin with a low DB is, however, also effective in preventing the induction of doxorubicin-induced intestinal damage. CONCLUSION: These pectin structures with stronger TLR2-inhibiting properties may prevent the development of doxorubicin-induced intestinal damage in patients undergoing chemotherapeutic treatment with doxorubicin.

Asunto(s)

Doxorrubicina/efectos adversos , Intestino Delgado/efectos de los fármacos , Mucositis/inducido químicamente , Mucositis/tratamiento farmacológico , Pectinas/farmacología , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/farmacología , Antibióticos Antineoplásicos/efectos adversos , Apoptosis/efectos de los fármacos , Línea Celular , Relación Dosis-Respuesta a Droga , Esterificación , Femenino , Enfermedades Intestinales/inducido químicamente , Enfermedades Intestinales/tratamiento farmacológico , Enfermedades Intestinales/patología , Mucosa Intestinal/efectos de los fármacos , Intestino Delgado/patología , Ratones Endogámicos C57BL , Mucositis/patología , Pectinas/administración & dosificación , Pectinas/química , Peritonitis/inducido químicamente , Peritonitis/tratamiento farmacológico , Peritonitis/patología , Relación Estructura-Actividad , Receptor Toll-Like 2/antagonistas & inhibidores , Receptor Toll-Like 2/metabolismo

RESUMEN

Phytic acid, the principal storage form of phosphorus in wheat, plays both beneficial and antinutrient functions for human being, and its analytical method still needs further development. In this work, we have developed a new method for the determination of phytic acid in wheat products based on derivatization with (trimethylsilyl)diazomethane in combination with liquid chromatography-mass spectrometry analysis. Methyl esterification greatly decreased the polarity and the acidity of phytic acid, and thus the corresponding derivative can be easily analyzed by liquid chromatography-mass spectrometry under common conditions. Furthermore, treatment with cation exchange resin removed the polyvalent metal ions in the solutions, and thus derivatization of phytic acid can be achieved efficiently and completely. The standard curve for phytic acid has been well established in the linear range of 0.5-100 ng/mL with squared correlation coefficient more than 0.999 and the quantification limit of 0.25 ng/mL. The phytic acid content varies greatly in different wheat products, ranging from 153.5 to 17299.0 µg/g.

Asunto(s)

Ácido Fítico/análisis , Triticum/química , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida/métodos , Esterificación , Fósforo/análisis , Extracción en Fase Sólida , Espectrometría de Masas en Tándem/métodos

RESUMEN

One of the possible mechanisms of the anti-inflammatory action of pectins is associated with the inhibition of excessive pro-inflammatory activity of macrophages - the cells that regulate inflammation intensity and reparative regeneration. It has been found that pectins with a low degree of methyl esterification of the carboxyl groups of the galacturonan core of the macromolecule exhibit this effect. In addition to leukocytes, intestinal epithelial cells are also involved in the pathogenesis of inflammatory bowel diseases. However, to date, there have been insufficient studies of the effect of pectin methyl esterification on the inflammatory response of enterocytes. The aim of the research was to evaluate the effect of the degree of pectin methyl esterification on inflammation of the colon in mice after oral administration and on the inflammatory response of human colon epithelium cells of the Caco-2 line in vitro. Material and methods. In a prospective study, 40 male BALB/c mice weighing 20-25 g were used, 10 animals in each group. Solutions of apple pectins (200 mg/0.2 ml) were orally administered to mice through a plastic catheter 24 h before the induction of colitis. The control mice received water, and prednisone administration at a dose of 5 mg/kg of body weight was used as a positive control. Colon inflammation in mice was induced by a single rectal administration of 5% acetic acid (0.1 ml). A day later, the degree and area of the lesion was assessed using a light microscope, the activity of myeloperoxidase in the wall of the colon was determined by spectrophotometry. The effect of pectins on metabolic activity, intercellular permeability, Tumor Necrosis Factor α generation and alkaline phosphatase (ALP) activity in Caco-2 cells was assessed. Results. It was found that low-methyl esterified pectin AU701, which contains more than 70% of free carboxyl groups, inhibited colon inflammation in mice. High methyletherified pectin AU201, in which more than 70% of the carboxyl groups are replaced by methyl ester, didn't affect inflammation. It was revealed that pretreatment of Caco-2 cells with AU701 and AU201 pectins prevented lipopolysaccharide-induced increase in intercellular permeability and reduced the pro-inflammatory response of Caco-2 cells to LPS. After incubation of Caco-2 cells with AU701 pectin, the rate of hydrolysis of p-nitrophenyl phosphate (an alkaline phosphate substrate) increased by 40%. Pectin AU201 had no effect on the alkaline phosphatase activity of enterocytes. Conclusion. Thus, it was found that low-methyl esterified pectin AU701 inhibits inflammation both in vivo and in vitro. High-methyl esterified pectin AU201 suppresses pro-inflammatory reactions only in vitro. The ability of pectins to inhibit intestinal inflammation has a multifactorial nature, and is due, inter alia, to their ability to stimulate the expression of alkaline phosphatase by enterocytes.

Asunto(s)

Malus , Animales , Antiinflamatorios/farmacología , Células CACO-2 , Humanos , Masculino , Malus/metabolismo , Ratones , Pectinas/química , Estudios Prospectivos

RESUMEN

Pectins have anti-inflammatory effects via Toll-like receptor (TLR) inhibition in a degree of methyl-esterification-(DM)-dependent manner. However, pectins also vary in distribution of methyl-esters over the galacturonic-acid (GalA) backbone (Degree of Blockiness - DB) and impact of this on anti-inflammatory capacity is unknown. Pectins mainly inhibit TLR2-1 but magnitude depends on both DM and DB. Low DM pectins (DM18/19) with both low (DB86) and high DB (DB94) strongly inhibit TLR2-1. However, pectins with intermediate DM (DM43/DM49) and high DB (DB60), but not with low DB (DB33), inhibit TLR2-1 as strongly as low DM. High DM pectins (DM84/88) with DB71 and DB91 do not inhibit TLR2-1 strongly. Pectin-binding to TLR2 was confirmed by capture-ELISA. In human macrophages, low DM and intermediate DM pectins with high DB inhibited TLR2-1 induced IL-6 secretion. Both high number and blockwise distribution of non-esterified GalA in pectins are responsible for the anti-inflammatory effects via inhibition of TLR2-1.

Asunto(s)

Esterificación , Ésteres/química , Inflamación/metabolismo , Pectinas/química , Receptor Toll-Like 2/metabolismo , Antiinflamatorios/química , Antiinflamatorios/farmacología , Línea Celular , Cromatografía Líquida de Alta Presión , Ésteres/metabolismo , Ácidos Hexurónicos/química , Humanos , Macrófagos , Pectinas/farmacología , Receptor Toll-Like 2/efectos de los fármacos

RESUMEN

Pectin methyl-esterases (PMEs) play crucial roles in plant growth. In this study, we identified 81 PbrPMEs in pear. Whole-genome duplication and purifying selection drove the evolution of PbrPME gene family. The expression of 47 PbrPMEs was detected in pear pollen tube, which were assigned to 13 clusters by an expression tendency analysis. One of the 13 clusters presented opposite expression trends towards the changes of methyl-esterified pectins at the apical cell wall. PbrPMEs were localized in the cytoplasm and plasma membrane. Repression of PbrPME11, PbrPME44, and PbrPME59 resulted in the inhibition of pear pollen tube growth and abnormal deposition of methyl-esterified pectins at pollen tube tip. Pharmacological analysis confirmed that reduced PbrPME activities repressed the pollen tube growth. Overall, we have explored the evolutionary characteristics of PbrPME gene family and found the key PbrPME genes that control the growth of pollen tube, which deepened the understanding of pear fertility regulation.

Asunto(s)

Esterasas/genética , Pectinas/metabolismo , Tubo Polínico/enzimología , Tubo Polínico/crecimiento & desarrollo , Pyrus/enzimología , Pyrus/crecimiento & desarrollo , Mapeo Cromosómico , Esterasas/clasificación , Esterasas/metabolismo , Genes de Plantas , Genoma de Planta , Familia de Multigenes , Motivos de Nucleótidos , Filogenia , Tubo Polínico/metabolismo , Pyrus/genética , Pyrus/metabolismo , Sintenía

RESUMEN

A series of methyl alginate with different degree of esterification (DE) were prepared with low cost, and its application in acidified milk drinks (AMDs) was investigated. The gel strength, molecular weight, solution apparent viscosity and optical rotation value of methyl alginate all decreased with the increase of DE. Methyl alginate with DE equal or larger than 60.7% was more effective in stabilizing AMDs than high-methoxyl pectin (HMP) under the same conditions, and the higher the DE, the better its stabilizing ability. The methyl alginate had better synergistic action for stabilizing AMDs with propylene glycol alginate (PGA) than HMP. The reason for this could be attributed to that methyl alginate and PGA had the same main chain structure, and the same levorotatory optical activity. The results indicated that the methyl alginate had a potential industry application prospect for stabilizing AMDs as an alternative to HMP.

Asunto(s)

Ácido Algínico/química , Bebidas/análisis , Leche/química , Animales , Esterificación , Concentración de Iones de Hidrógeno , Tamaño de la Partícula , Viscosidad