The detrimental role of galectin-3 and endoplasmic reticulum stress in the cardiac consequences of myocardial ischemia in the context of obesity.

The association between cardiac fibrosis and galectin-3 was evaluated in patients with acute myocardial infarction (MI). The role of galectin-3 and its association with endoplasmic reticulum (ER) stress activation in the progression of cardiovascular fibrosis was also evaluated in obese-infarcted rats. The inhibitor of galectin-3 activity, modified citrus pectin (MCP; 100 mg/kg/day), and the inhibitor of the ER stress activation, 4-phenylbutyric acid (4-PBA; 500 mg/kg/day), were administered for 4 weeks after MI in obese rats. Overweight-obese patients who suffered a first MI showed higher circulating galectin-3 levels, higher extracellular volume, and LV infarcted size, as well as lower E/e'ratio and LVEF compared with normal-weight patients. A correlation was observed between galectin-3 levels and extracellular volume. Obese-infarcted animals presented cardiac hypertrophy and reduction in LVEF, and E/A ratio as compared with control animals. They also showed an increase in galectin-3 gene expression, as well as cardiac fibrosis and reduced autophagic flux. These alterations were associated with ER stress activation characterized by enhanced cardiac levels of binding immunoglobulin protein, which were correlated with those of galectin-3. Both MCP and 4-PBA not only reduced cardiac fibrosis, oxidative stress, galectin-3 levels, and ER stress activation, but also prevented cardiac functional alterations and ameliorated autophagic flux. These results show the relevant role of galectin-3 in the development of diffuse fibrosis associated with MI in the context of obesity in both the animal model and patients. Galectin-3 in tandem with ER stress activation could modulate different downstream mechanisms, including inflammation, oxidative stress, and autophagy.

Prebiotic fibre mixtures counteract the manifestation of gut microbial dysbiosis induced by the chemotherapeutic 5-Fluorouracil (5-FU) in a validated in vitro model of the colon.

BACKGROUND: 5-Fluorouracil (5-FU) is used as an antineoplastic agent in distinct cancer types. Increasing evidence suggests that the gut microbiota might modulate 5-FU efficacy and toxicity, potentially affecting the patient's prognosis. The current experimental study investigated 5-FU-induced microbiota alterations, as well as the potential of prebiotic fibre mixtures (M1-M4) to counteract these shifts. METHODS: A pooled microbial consortium was derived from ten healthy donors, inoculated in an in vitro model of the colon, and treated with 5-FU, with or without prebiotic fibre mixtures for 72 h. Four different prebiotic fibre mixtures were tested: M1 containing short-chain galacto-oligosaccharides (sc GOS), long-chain fructo-oligosaccharides (lcFOS), and low viscosity pectin (lvPect), M2 consisting of arabinoxylan, beta-glucan, pectin, and resistant starch, M3 which was a mixture of scGOS and lcFOS, and M4 containing arabinoxylan, beta-glucan, pectin, resistant starch, and inulin. RESULTS: We identified 5-FU-induced changes in gut microbiota composition, but not in microbial diversity. Administration of prebiotic fibre mixtures during 5-FU influenced gut microbiota composition and taxa abundance. Amongst others, prebiotic fibre mixtures successfully stimulated potentially beneficial bacteria (Bifidobacterium, Lactobacillus, Anaerostipes, Weissella, Olsenella, Senegalimassilia) and suppressed the growth of potentially pathogenic bacteria (Klebsiella, Enterobacter) in the presence of 5-FU. The short-chain fatty acid (SCFA) acetate increased slightly during 5-FU, but even more during 5-FU with prebiotic fibre mixtures, while propionate was lower due to 5-FU with or without prebiotic fibre mixtures, compared to control. The SCFA butyrate and valerate did not show differences among all conditions. The branched-chain fatty acids (BCFA) iso-butyrate and iso-valerate were higher in 5-FU, but lower in 5-FU + prebiotics, compared to control. CONCLUSIONS: These data suggest that prebiotic fibre mixtures represent a promising strategy to modulate 5-FU-induced microbial dysbiosis towards a more favourable microbiota, thereby possibly improving 5-FU efficacy and reducing toxicity, which should be evaluated further in clinical studies.

Impact of Plant-Based Dietary Fibers on Metabolic Homeostasis in High-Fat Diet Mice via Alterations in the Gut Microbiota and Metabolites.

BACKGROUND: The gut microbiota contributes to metabolic disease, and diet shapes the gut microbiota, emphasizing the need to better understand how diet impacts metabolic disease via gut microbiota alterations. Fiber intake is linked with improvements in metabolic homeostasis in rodents and humans, which is associated with changes in the gut microbiota. However, dietary fiber is extremely heterogeneous, and it is imperative to comprehensively analyze the impact of various plant-based fibers on metabolic homeostasis in an identical setting and compare the impact of alterations in the gut microbiota and bacterially derived metabolites from different fiber sources. OBJECTIVES: The objective of this study was to analyze the impact of different plant-based fibers (pectin, ß-glucan, wheat dextrin, resistant starch, and cellulose as a control) on metabolic homeostasis through alterations in the gut microbiota and its metabolites in high-fat diet (HFD)-fed mice. METHODS: HFD-fed mice were supplemented with 5 different fiber types (pectin, ß-glucan, wheat dextrin, resistant starch, or cellulose as a control) at 10% (wt/wt) for 18 wk (n = 12/group), measuring body weight, adiposity, indirect calorimetry, glucose tolerance, and the gut microbiota and metabolites. RESULTS: Only ß-glucan supplementation during HFD-feeding decreased adiposity and body weight gain and improved glucose tolerance compared with HFD-cellulose, whereas all other fibers had no effect. This was associated with increased energy expenditure and locomotor activity in mice compared with HFD-cellulose. All fibers supplemented into an HFD uniquely shifted the intestinal microbiota and cecal short-chain fatty acids; however, only ß-glucan supplementation increased cecal butyrate concentrations. Lastly, all fibers altered the small-intestinal microbiota and portal bile acid composition. CONCLUSIONS: These findings demonstrate that ß-glucan consumption is a promising dietary strategy for metabolic disease, possibly via increased energy expenditure through alterations in the gut microbiota and bacterial metabolites in mice.

Pectinose induces cell cycle arrest in luminal A and triple-negative breast cancer cells by promoting autophagy through activation of the p38 MAPK signaling pathway.

Breast cancer patients often have a poor prognosis largely due to lack of effective targeted therapy. It is now well established that monosaccharide enhances growth retardation and chemotherapy sensitivity in tumor cells. However, Pectinose whether has capability to restrict the proliferation of tumor cells remain unclear. Here, we report that Pectinose induced cytotoxicity is modulated by autophagy and p38 MAPK signaling pathway in breast cancer cell lines. The proliferation of cells was dramatically inhibited by Pectinose exposure in a dose-dependent manner, which was relevant to cell cycle arrest, as demonstrated by G2/M cell cycle restriction and ectopic expression of Cyclin A, Cyclin B, p21and p27. Mechanistically, we further identified that Pectinose is positively associated with autophagy and the activation of the p38 MAPK signaling in breast cancer. In contrast, 3-Ma or SB203580, the inhibitor of autophagy or p38 MAPK, reversed the efficacy of Pectinose suppressing on breast cancer cell lines proliferation and cell cycle process. Additionally, Pectinose in vivo treatment could significantly inhibit xenograft growth of breast cancer cells. Taken together, our findings were the first to reveal that Pectinose triggered cell cycle arrest by inducing autophagy through the activation of p38 MAPK signaling pathway in breast cancer cells,especially in luminal A and triple-negative breast cancer.

Pectin: Health-promoting properties as a natural galectin-3 inhibitor.

Galectin-3 has a variety of important pathophysiological significance in the human body. Much evidence shows that the abnormal expression of galectin-3 is related to the formation and development of many diseases. Pectin is mostly obtained from processed citrus fruits and apples and is a known natural inhibitor of galactin-3. A large number of peels produced each year are discarded, and it is necessary to recycle some of the economically valuable active compounds in these by-products to reduce resource waste and environmental pollution. By binding with galectin-3, pectin can directly reduce the expression level of galectin-3 on the one hand, and regulate the expression level of cytokines by regulating certain signaling pathways on the other hand, to achieve the effect of treating diseases. This paper begins by presenting an overview of the basic structure of pectin, subsequently followed by a description of the structure of galectin-3 and its detrimental impact on human health when expressed abnormally. The health effects of pectin as a galectin-3 inhibitor were then summarized from the perspectives of anticancer, anti-inflammatory, ameliorating fibrotic diseases, and anti-diabetes. Finally, the challenges and prospects of future research on pectin are presented, which provide important references for expanding the application of pectin in the pharmaceutical industry or developing functional dietary supplements.

Cryoprotective Polysaccharides with Ordered Gel Structures Induce Ice Growth Anticipation and Survival Enhancement during Cell Cryopreservation.

This work cross-correlated rheological, thermodynamic, and conformational features of several natural polysaccharides to their cryoprotective performance. The basis of cryoprotection of FucoPol, pectin, and agar revealed a causal combination of (i) an emerging sol-gel transition (p = 0.014) at near-hypothermia (4 °C), (ii) noncolligative attenuated supercooling of the kinetic freezing point of water (p = 0.026) supporting ice growth anticipation, and (iii) increased conformational order (p < 0.0001), where helix-/sheet-like features boost cryoprotection. FucoPol, of highest cryoprotective performance, revealed a predominantly helical structure (α/ß = 1.5) capable of forming a gel state at 4 °C and the highest degree of supercooling attenuation (TH = 6.2 °C). Ice growth anticipation with gel-like polysaccharides suggests that the gel matrix neutralizes elastic deformations and lethal cell volumetric fluctuations during freezing, thus preventing the loss of homeostasis and increasing post-thaw viability. Ultimately, structured gels capable of attenuated supercooling enable cryoprotective action at the polymer-cell interface, in addition to polymer-ice interactions. This rationale potentiates implementing alternative, biobased, noncytotoxic polymers in cryobiology.

Polysaccharides (pectin, mucilage, and fructan inulin) and their fermented products: A critical analysis of their biochemical, gut interactions, and biological functions as antidiabetic agents.

Diabetes mellitus is a globally metabolic endocrine syndrome marked by a deficiency of insulin secretion (type-1 DM) or glucose intolerance arising from insulin response impairment (type-2 DM) leading to abnormal glucose metabolism. With an increasing interest in natural dietary components for diabetes management, the identification of novel agents witnessed major discoveries. Plant-derived mucilage, pectin, and inulin are important non-starch polysaccharides that exhibit effective antidiabetic properties often termed soluble dietary fiber (SDF). SDF affects sugar metabolism through multiple mechanisms affecting glucose absorption and diffusion, modulation of carbohydrate metabolizing enzymes (α-amylase and α-glucosidase), ameliorating ß-pancreatic cell dysfunction, and improving insulin release or sensitivity. Certain SDFs inhibit dipeptidyl peptidase-4 and influence the expression levels of genes related to glucose metabolism. This review is designed to discuss holistically and critically the antidiabetic effects of major SDF and their underlying mechanisms of action. This review should aid drug discovery approaches in developing novel natural antidiabetic drugs from SDF.

Modified Citrus Pectin (MCP) Confers a Renoprotective Effect on Early-Stage Nephropathy in Type-2 Diabetic Mice.

Diabetic nephropathy (DN) is a significant global health concern with a high morbidity rate. Accumulating evidence reveals that Galectin-3 (Gal-3), a ß-galactoside-binding lectin, is a biomarker in kidney diseases. Our study aimed to assess the advantageous impacts of modified citrus pectin (MCP) as an alternative therapeutic strategy for the initial and ongoing progression of DN in mice with type 2 diabetes mellitus (T2DM). The animal model has been split into four groups: control group, T2DM group (mice received intraperitoneal injections of nicotinamide (NA) and streptozotocin (STZ), T2DM+MCP group (mice received 100 mg/kg/day MCP following T2DM induction), and MCP group (mice received 100 mg/kg/day). After 4 weeks, kidney weight, blood glucose level, serum kidney function tests, histopathological structure alterations, oxidative stress, inflammation, apoptosis, and fibrosis parameters were determined in renal tissues. Our findings demonstrated that MCP treatment reduced blood glucose levels, renal histological damage, and restored kidney weight and kidney function tests. Additionally, MCP reduced malondialdehyde level and restored glutathione level, and catalase activity. MCP demonstrated a notable reduction in inflammatory and apoptosis mediators TNF-α, iNOS, TGF-ßRII and caspase-3. Overall, MCP could alleviate renal injury in an experimental model of DN by suppressing renal oxidative stress, inflammation, fibrosis, and apoptosis mediators.

Phosphorus deficiency-induced cell wall pectin demethylesterification enhances cadmium accumulation in roots of Salix caprea.

Regions affected by heavy metal contamination frequently encounter phosphorus (P) deficiency. Numerous studies highlight crucial role of P in facilitating cadmium (Cd) accumulation in woody plants. However, the regulatory mechanism by which P affects Cd accumulation in roots remains ambiguous. This study aims to investigate the effects of phosphorus (P) deficiency on Cd accumulation, Cd subcellular distribution, and cell wall components in the roots of Salix caprea under Cd stress. The results revealed that under P deficiency conditions, there was a 35.4% elevation in Cd content in roots, coupled with a 60.1% reduction in Cd content in shoots, compared to the P sufficiency conditions. Under deficient P conditions, the predominant response of roots to Cd exposure was the increased sequestration of Cd in root cell walls. The sequestration of Cd in root cell walls increased from 37.1% under sufficient P conditions to 66.7% under P deficiency, with pectin identified as the primary Cd binding site under both P conditions. Among cell wall components, P deficiency led to a significant 31.7% increase in Cd content within pectin compared to P sufficiency conditions, but did not change the pectin content. Notably, P deficiency significantly increased pectin methylesterase (PME) activity by regulating the expression of PME and PMEI genes, leading to a 10.4% reduction in the degree of pectin methylesterification. This may elucidate the absence of significant changes in pectin content under P deficiency conditions and the concurrent increase in Cd accumulation in pectin. Fourier transform infrared spectroscopy (FTIR) results indicated an increase in carboxyl groups in the root cell walls under P deficiency compared to sufficient P treatment. The results provide deep insights into the mechanisms of higher Cd accumulation in root mediated by P deficiency.

Antibacterial and Anti-Inflammatory Polysaccharide from Fructus Ligustri Lucidi Incorporated in PVA/Pectin Hydrogels Accelerate Wound Healing.

In cutaneous wound healing, an overproduction of inflammatory chemokines and bacterial infections impedes the process. Hydrogels can maintain a physiologically moist microenvironment, absorb chemokines, prevent bacterial infection, inhibit bacterial reproduction, and facilitate wound healing at a wound site. The development of hydrogels provides a novel treatment strategy for the entire wound repair process. Here, a series of Fructus Ligustri Lucidi polysaccharide extracts loaded with polyvinyl alcohol (PVA) and pectin hydrogels were successfully fabricated through the freeze-thaw method. A hydrogel containing a 1% mixing weight ratio of FLL-E (named PVA-P-FLL-E1) demonstrated excellent physicochemical properties such as swellability, water retention, degradability, porosity, 00drug release, transparency, and adhesive strength. Notably, this hydrogel exhibited minimal cytotoxicity. Moreover, the crosslinked hydrogel, PVA-P-FLL-E1, displayed multifunctional attributes, including significant antibacterial properties, earlier re-epithelialization, production of few inflammatory cells, the formation of collagen fibers, deposition of collagen I, and faster remodeling of the ECM. Consequently, the PVA-P-FLL-E1 hydrogel stands out as a promising wound dressing due to its superior formulation and enhanced healing effects in wound care.

Investigation of the Structural Properties and Antioxidant Potency of Pectic Polysaccharides Derived from Rohdea japonica (Thunb.) Roth.

This study investigated the structural composition and antioxidant properties of pectic polysaccharides extracted from Rohdea japonica (Thunb.) Roth. Pectins, which belong to a complex category of acidic polysaccharides, possess a wide range of biological effects stemming from their distinctive structural domains. The polysaccharides were extracted using water, and were subsequently purified through ion exchange and gel permeation chromatography. In order to elucidate their structural features, Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance techniques were applied. Two specific polysaccharides, WRJP-A2a and WRJP-A3b, with molecular weights of 42.7 kDa and 64.1 kDa, respectively, were identified to contain varying proportions of homogalacturonan, rhamnogalacturonan I, and rhamnogalacturonan II domains. Regarding antioxidant capacity, WRJP-A3b exhibited superior scavenging capabilities against DPPH, ABTS, and hydroxyl radicals, potentially attributed to its higher galacturonic acid content and abundance of homogalacturonan domains. These results enhance our comprehension of the structure-activity interplay of pectic polysaccharides sourced from Rohdea japonica (Thunb.) Roth and their potential utility in the healthcare and functional food sectors.

Biological Activity of Hybrid Vaterite-Pectin Microparticles Towards Bacteria E. coli and Human Neutrophils.

Interaction of microbiota with hybrid vaterite-pectin microparticles as an attractive multifunctional vehicle for mucosal delivery should not provoke inflammation. Our purpose was to study the reaction of bacteria E. coli strain Mg1655 and isolate SharL from a patient with Crohn disease on the cultivation with hybrid microparticles and vaterite, and the subsequent activation of neutrophils. Vaterite-pectin microparticles enhanced leakage of ATP from bacteria. For E. coli Mg1655, the concentration of DNA decreased, while intracellular ATP increased. For E. coli SharL, the intracellular ATP decreased with simultaneous growth of DNA. Bacteria and microparticles together did not enhance activation of neutrophils in comparison with the particles per se in the medium without serum and in comparison with bacteria in the medium supplemented with serum; microparticles did not reduce functional activity of neutrophils.

Evaluation of citrus pectin capped copper sulfide nanoparticles against Candidiasis causing Candida biofilms.

The incidence of candidiasis has significantly increased globally in recent decades, and it is a significant source of morbidity and mortality, particularly in critically ill patients. Candida sp. ability to generate biofilms is one of its primary pathogenic traits. Drug-resistant strains have led to clinical failures of traditional antifungals, necessitating the development of a more modern therapy that can inhibit biofilm formation and enhance Candida sp. sensitivity to the immune system. The present study reports the anticandidal potential of pectin-capped copper sulfide nanoparticles (pCuS NPs) against Candida albicans. The pCuS NPs inhibit C. albicans growth at a minimum inhibitory concentration (MIC) of 31.25 µM and exhibit antifungal action by compromising membrane integrity and overproducing reactive oxygen species. The pCuS NPs, at their biofilm inhibitory concentration (BIC) of 15.63 µM, effectively inhibited C. albicans cells adhering to the glass slides, confirmed by light microscopy and scanning electron microscopy. Phase contrast microscopy pictures revealed that NPs controlled the morphological transitions between the yeast and hyphal forms by limiting conditions that led to filamentation and reducing hyphal extension. In addition, C. albicans showed reduced exopolysaccharide (EPS) production and exhibited less cell surface hydrophobicity (CSH) after pCuS NPs treatment. The findings suggest that pCuS NPs may be able to inhibit the emergence of virulence traits that lead to the formation of biofilms, such as EPS, CSH, and hyphal morphogenesis. The results raise the possibility of developing NPs-based therapies for C. albicans infections associated with biofilms.

Pectin alleviates the pulmonary inflammatory response induced by PM2.5 from a pig house by modulating intestinal microbiota.

This study aimed to investigate whether dietary fiber pectin can alleviate PM2.5-induced pulmonary inflammation and the potential mechanism. PM2.5 samples were collected from a nursery pig house. The mice were divided into three groups: the control group, PM2.5 group and PM2.5 + pectin group. The mice in the PM2.5 group were intratracheally instilled with PM2.5 suspension twice a week for four consecutive weeks, and those in the PM2.5 + pectin group were subject to the same PM2.5 exposure, but fed with a basal diet supplemented with 5% pectin. The results showed that body weight and feed intake were not different among the treatments (p > 0.05). However, supplementation with pectin relieved PM2.5-induced pulmonary inflammation, presenting as slightly restored lung morphology, decreased mRNA expression levels of IL-1ß, IL-6 and IL-17 in the lung, decreased MPO content in bronchoalveolar lavage fluid (BLAF), and even decreased protein levels of IL-1ß and IL-6 in the serum (p < 0.05). Dietary pectin altered the composition of the intestinal microbiota, increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes/Bacteroidetes. At the genus level, short-chain fatty acid (SCFA)-producing bacteria, such as Bacteroides, Anaerotruncus, Prevotella 2, Parabacteroides, Ruminococcus 2 and Butyricimonas, were enriched in the PM2.5 +pectin group. Accordingly, dietary pectin increased the concentrations of SCFAs, including acetate, propionate, butyrate and valerate, in mice. In conclusion, dietary fermentable fiber pectin can relieve PM2.5-induced pulmonary inflammation via alteration of intestinal microbiota composition and SCFA production. This study provides a new insight into reducing the health risk associated with PM2.5 exposure.

Effect of calcium chloride and gelling agents on the physicochemical and sensory characteristics of sugar-free banana preserves.

Banana preserve is produced by mixing the puree of the fruit with sucrose and organic acids. However, concerns about body esthetics or health reasons have encouraged the search for low-calorie products. Therefore, the objective of this study was to evaluate the effect of calcium chloride (CaCl2), carrageenan gum, and low methoxyl pectin (LM-pectin) on the physicochemical and sensory characteristics of sugar-free banana preserves. By using a central composite rotational design (CCRD) of 2³ + 6 axial points + 4 central points, we obtained 18 formulations that were further tested. Lower CaCl2 concentrations (0.54% to 0.61%) resulted in preserves with lower pH and more vivid color. The increased concentration of LM-pectin (1.40% to 1.64%) resulted in formulations with a yellowish-red hue and with lower moisture, thus, reducing the flavor and purchase intention of the product. Higher concentrations of carrageenan gum (1.04% to 1.15%) decreased the perception of banana preserve aroma. Therefore, concentrations of CaCl2 ranging from 0.54% to 0.61%, carrageenan gum ranging from 0.74% to 0.89% and LM-pectin ranging from 1.40% to 1.64% resulted in sugar-free banana preserves with ideal sweetness and consistency and were, therefore, more acceptable.

Characterization and In Vivo Assay of Allantoin-Enriched Pectin Hydrogel for the Treatment of Skin Wounds.

This work describes a liquid allantoin-enriched pectin hydrogel with hydrophilic behavior that is supported by the presence of functional groups related to healing efficacy. A topical study shows the effect of the hydrogel application on surgically induced skin wound healing in a rat model. Contact angle measurements confirm hydrophilic behavior (11.37°), while Fourier-transform infrared spectroscopy indicates the presence of functional groups related to the healing effectiveness (carboxylic acid and amine groups). Allantoin is distributed on the surface and inside the amorphous pectin hydrogel surrounded by a heterogeneous distribution of pores. This promotes wound drying with better interaction between the hydrogel and cells involved in the wound healing process. An experimental study with female Wistar rats indicates that the hydrogel improves wound contraction, reducing around 71.43% of the total healing time and reaching total wound closure in 15 days.

Synthesis and Characterization of a Biopolymer Pectin/Ethanolic Extract from Olive Mill Wastewater: In Vitro Safety and Efficacy Tests on Skin Wound Healing.

Wound-healing delay is one of the major problems of type 2 diabetes, representing also a clinical emergency in non-healing chronic wounds. Natural antioxidants show interesting wound-healing properties, including those extracted from waste derived from olive oil production. Olive mill wastewater is one of the main by-products of the olive oil-making process, and it is rich in high-value secondary metabolites, mainly hydroxytyrosol. We proposed an eco-friendly extraction method, employing both ultrasound-assisted and Soxhlet techniques and ethanol as a solvent, to recover valuable molecules from Roggianella cv (Olea europea L.) olive mill wastewater, which was further entrapped in a pectin polymer via an enzymatic reaction using porcine pancreatic lipase. Pectin, in combination with other substances, promoted and accelerated wound healing and demonstrated good potential to produce a biomedical conjugate for wound treatment. The antioxidant activity of the extracts and conjugate were evaluated against lipophilic (IC50 equal to 0.152 mg mL-1) and hydrophilic (IC50 equal to 0.0371 mg mL-1) radical species as well as the in vitro cytotoxicity via NRU, h-CLAT, and a wound-healing scratch assay and assessment. The pectin conjugate did not exert hemolytic effects on the peripheral blood, demonstrating interesting wound-healing properties due to its ability to stimulate cell proliferation in a dose-dependent manner.

Incorporation of Pectin into Vaterite Microparticles Prevented Effects of Adsorbed Mucin on Neutrophil Activation.

The application of vaterite microparticles for mucosal delivery depends on their interaction with mucin and immune cells. As we have shown previously, the binding of mucin onto particles enhances the generation of reactive oxygen species by neutrophils. The attenuation of the pro-oxidant effect of the bound mucin through the modification of vaterite could improve its biocompatibility. Hybrid microparticles composed of vaterite and pectin (CCP) were prepared using co-precipitation. In comparison with vaterite (CC), they had a smaller diameter and pores, a greater surface area, and a negative zeta-potential. We aimed to study the cytotoxicity and mucin-dependent neutrophil-activating effect of CCP microparticles. The incorporated pectin did not influence the neutrophil damage according to a lactate dehydrogenase test. The difference in the CC- and CCP-elicited luminol or lucigenin chemiluminescence of neutrophils was insignificant, with no direct pro- or antioxidant effects from the incorporated pectin. Unlike soluble pectin, the CCP particles were ineffective at scavenging radicals in an ABAP-luminol test. The fluorescence of SYTOX Green demonstrated a CCP-stimulated formation of neutrophil extracellular traps (NETs). The pre-treatment of CC and CCP with mucin resulted in a 2.5-times-higher CL response of neutrophils to the CC-mucin than to the CCP-mucin. Thus, the incorporation of pectin into vaterite microspheres enabled an antioxidant effect to be reached when the neutrophils were activated by mucin-treated microparticles, presumably via exposed ligands.

[Gastroprotective and antidepressant-like effect of plum pectin (Prunus domestica L.) under water-immobilization stress in laboratory mice].

Stress effects activate the processes of free radical oxidation in the organism, lead to hyper production of reactive radicals and oxidative stress, provoking the development of an inflammatory process in various parts of the gastrointestinal tract. Pectin polysaccharides together with the enzyme components of the endogenous antioxidant system contribute to the elimination of the imbalance between prooxidants and antioxidants in the tissues of stressed animals and have a gastroprotective and antidepressant-like effect. The aim of the research was to evaluate the gastroprotective, antioxidant and antidepressant-like effect of plum pectin orally administered to white laboratory mice before stressful exposure. Material and methods. In the experiment on white BALB/c mice weighing 20-25 g (90 males, 10 in each group), pectin isolated from fresh plum fruits in an artificial gastric environment was used. It was administered orally to mice 24 h before the onset of stress exposure or behavioral activity asessment. 50 animals were subjected to 5 h of water immersion stress. After this corticosterone concentration in blood plasma, and the activity of superoxide dismutase, catalase and glutathione peroxidase in the tissue supernatants of the gastrointestinal tract were determined, and the condition of the gastric mucosa was also assessed. Behavioral activity of experimental mice (n=30) was assessed in the open field and forced swimming tests. Results. The stress effect was accompanied by an increase in plasma corticosterone concentration (more than 3 fold), in the activity of superoxide dismutase, glutathione peroxidase in the tissues of the stomach wall and small intestine (17.9-28.6%) and destructive damage in the gastric mucosa compared with the indices of intact animals. Preliminary oral administration of plum pectin to animals at a dose of 80 mg per 1 kg of body weight helped to reduce the level of corticosterone and the number of stress-induced hemorrhages on the gastric mucosa, normalized the activity of antioxidant enzymes and also decreased the immobility time of mice in the forced swimming test. Preliminary oral administration of plum pectin to animals at a dose of 80 mg per 1 kg of body weight prevented an increase in the activity of antioxidant enzymes, corticosterone in the blood and the development of stress-induced hemorrhages on the gastric mucosa, and reduced the time of immobility of mice in the forced swimming test. Conclusion. Plum fruit pectin pre-administered into mice before stress prevents stress-induced damage in the tissues of the gastrointestinal tract, contributing to an increase in the body's resistance to the stress factor. Plum pectin has an antioxidant, gastroprotective and antidepressant-like effect and can be used as an ingredient in functional foods that reduce the risk of inflammatory diseases of the gastrointestinal tract under stress.

Impact of pectin with various esterification degrees on the profiles of gut microbiota and serum metabolites.

Colitis is generally affected by multiple factors, including the dysbiosis of intestinal microbiota, and may affect organs outside colon through circulation. Pectin, which is an edible polysaccharide widely present in plant cell walls, has been proved in our previous study to possess preventive potentials against acute ulcerative colitis, especially when the esterification degree is less than 50%. This study aimed to clarify the underlying correlations of gut microbiome and serum metabolites with the preventive effects of pectin with different esterification degrees (H121, L13, and L102) against colitis in mice. MiSeq sequencing data showed that symbiotic bacteria especially beneficial Lactobacillus and Bifidobacterium were enriched by pectin intake. Fiber consumers such as Prevotella and Bacteroides actively responded to L13 pectin, particularly under high dosage (L13-H). In addition, the abnormal abundance of Akkermansia associated with colitis would not appear in mice who had been provided with any of the three pectins before dextran sulfate sodium (DSS) treatment. Furthermore, pre-treatment of H121 and L13 pectins could improve the serum glycerophospholipids such as phosphatidylcholine (PC) and phosphatidylethanolamine (PE). In contrast, lysophosphatidic acid (LPA) contributing to the glycerophospholipid metabolism pathway was enriched only in the L13-H group, which has been previously proved to be associated with the epithelial barrier and intestinal homeostasis. Positive relationships between the glycerophospholipids and the dominant candidates of intestinal bacteria such as Lactobacillus indicated the joint actions of intestinal microbes and serum metabolites as well as the underlying crosstalks among gut microbiome. Therefore, the results of this research suggested that the preventive effects of low-esterified pectin on DSS-induced colitis were likely to be initiated by the enrichment of probiotics in the gut and serum glycerophospholipids. KEY POINTS: • L13 pectin remarkably improved the diversity of the gut microbiome in healthy mice. • Probiotics were enriched and abnormal Akkermansia was restored by L13 and L102 pectins. • Glycerophospholipid metabolism was significantly enriched by H121 and L13 pectins.