Pectin Oligosaccharides Ameliorate Colon Cancer by Regulating Oxidative Stress- and Inflammation-Activated Signaling Pathways

Physicochemical properties, health benefits, and applications of the polysaccharides from Rosa rugosa Thunb.: A review

Rosa rugosa Thunb. (R. rugosa) has been used as food and medicine and not just as ornamental plant for nearly a thousand years, its nutritional and medicinal value have been recognized by people. It contains a variety of biological active ingredients that are beneficial to the human body. R. rugosa polysaccharides are also one of the main bioactive ingredients, which have many health benefits such as anti-diabetes, antioxidation, anti-inflammation, anti-tumour, moisture-preserving and anti-alcoholic liver disease. This review summarizes the extraction, purification, structural characteristics, health benefits, and structure-activity relationships of R. rugosa polysaccharides. In addition, current and potential applications of R. rugosa polysaccharides are analyzed and supplemented, hoping to provide some valuable insights for further research and development of functional food additives, nutritional supplements, additives for daily chemical products, and even pharmaceuticals.

Mannose coated selenium nanoparticles normalize intestinal homeostasis in mice and mitigate colitis by inhibiting NF-κB activation and enhancing glutathione peroxidase expression

Impaired intestinal homeostasis is a major pathological feature of inflammatory bowel diseases (IBD). Mannose and selenium (Se) both demonstrate potential anti-inflammatory and anti-oxidative properties. However, most lectin receptors bind free monosaccharide ligands with relatively low affinity and most Se species induce side effects beyond a very narrow range of dosage. This has contributed to a poorly explored therapies for IBD that combine mannose and Se to target intestinal epithelial cells (IECs) for normalization gut homeostasis. Herein, a facile and safe strategy for ulcerative colitis (UC) treatment was developed using optimized, mannose-functionalized Se nanoparticles (M-SeNPs) encapsulated within a colon-targeted hydrogel delivery system containing alginate (SA) and chitosan (CS). This biocompatible nanosystem was efficiently taken up by IECs and led to increased expression of Se-dependent glutathione peroxidases (GPXs), thereby modulating IECs' immune response. Using a mouse model of DSS-induced colitis, (CS/SA)-embedding M-SeNPs (C/S-MSe) were found to mitigate oxidative stress and inflammation through the inhibition of the NF-kB pathway in the colon. This stabilized mucosal homeostasis of IECs and ameliorated colitis-related symptoms, thereby providing a potential new approach for treatment of IBD.

Effects of passion fruit peel (Passiflora edulis) pectin and red yeast (Sporodiobolus pararoseus) cells on growth, immunity, intestinal morphology, gene expression, and gut microbiota in Nile tilapia (Oreochromis niloticus)

This study explores the effects of dietary supplementation with passion fruit peel pectin (Passiflora edulis) and red yeast cell walls (Sporidiobolus pararoseus) on growth performance, immunity, intestinal morphology, gene expression, and gut microbiota of Nile tilapia (Oreochromis niloticus). Nile tilapia with an initial body weight of approximately 15 ± 0.06 g were fed four isonitrogenous (29.09-29.94%), isolipidic (3.01-4.28%), and isoenergetic (4119-4214 Cal/g) diets containing 0 g kg-1 pectin or red yeast cell walls (T1 - Control), 10 g kg-1 pectin (T2), 10 g kg-1 red yeast (T3), and a combination of 10 g kg-1 pectin and 10 g kg-1 red yeast (T4) for 8 weeks. Growth rates and immune responses were assessed at 4 and 8 weeks, while histology, relative immune and antioxidant gene expression, and gut microbiota analysis were conducted after 8 weeks of feeding. The results showed that the combined supplementation (T4) significantly enhanced growth performance metrics, including final weight, weight gain, specific growth rate, and feed conversion ratio, particularly by week 8, compared to T1, T2, and T3 (P < 0.05). Immunological assessments revealed increased lysozyme and peroxidase activities in both skin mucus and serum, with the T4 group showing the most pronounced improvements. Additionally, antioxidant and immune-related gene expression, including glutathione peroxidase (GPX), glutathione reductase (GSR), and interleukin-1 (IL1), were upregulated in the gut, while intestinal morphology exhibited improved villus height and width. Gut microbiota analysis indicated increased alpha and beta diversity, with a notable rise in beneficial phyla such as Actinobacteriota and Firmicutes in the supplemented groups. These findings suggest that the combined use of pectin and red yeast cell walls as prebiotics in aquaculture can enhance the health and growth of Nile tilapia, offering a promising alternative to traditional practices. Further research is needed to determine optimal dosages for maximizing these benefits.

Optimization of Pectin Extraction from Melon Peel as a New Source of Pectin and Pectin Hydrolysate with Prebiotic Potential

Food wastes have a large number of functional ingredients that have potential for valorization. Melon peels are increasingly produced as waste in food industries in Thailand. This study aimed to optimize pectin extraction conditions from melon peel for its prebiotic potential. Optimization was conducted using a response surface methodology and Box-Behnken experimental design. An analysis of variance indicated a significant interaction between the extraction conditions on extraction yield and degree of esterification (DE). These include pH and solvent-to-sample ratio. The conditions for the extraction of pectin with low DE (LDP), medium DE (MDP) and high DE (HDP) were optimized. Pectin hydrolysate from LDP, MDP and HDP was prepared by enzymatic hydrolysis into LPEH, MPEH and HPEH, respectively. LDP, MDP, HDP, LPEH, MPEH and HPEH were compared for their efficiency in terms of the growth of three probiotic strains, namely Lactobacillus plantarum TISTR 877, Lactobacillus casei TISTR 390 and Enterococcus faecium TISTR 1027. Among the samples tested, HPEH showed the highest ability as a carbon source to promote the growth and prebiotic activity score for these three probiotic strains. This study suggests that melon peel waste from agro-industry can be a novel source for prebiotic production.

Novel role of homogalacturonan region of pectin in disrupting the interaction between fibronectin and integrin β1

Pectin interacts with fibronectin (FN), a modular protein in the extracellular matrix. This interaction is significant as FN plays a pivotal role by binding to the receptor integrin α5β1. However, the molecular mechanism underlying the pectin-FN interaction and its impact on integrin binding remains unknown. In this study, water-soluble pectins (WSPs) were extracted from three different pectin sources and subsequently characterized. These included Citrus WSP, which primarily comprises the homogalacturonan region, and Kaki and Yuzu WSPs, both of which are rich in rhamnogalacturonan regions. We investigated the molecular interactions between these WSPs and two FN fragments, Anastellin and RetroNectin, using surface plasmon resonance analysis. Citrus WSP exhibited a notable binding affinity to FN, with a dissociation constant (KD) of approximately 10-7 M. In contrast, Kaki and Yuzu WSPs displayed comparatively weaker or negligible binding affinities. The binding reactivity of Citrus WSP with FN was notably diminished following the enzymatic removal of its methyl-ester groups. Additionally, Citrus WSP disrupted the binding of integrin β1 to RetroNectin without altering the affinity, despite its minimal direct binding to integrin itself. This study furthers our understanding of the intricate pectin-FN interaction and sheds light on their potential physiological relevance and impact on cellular responses.

The Emulsification and Stabilization Mechanism of an Oil-in-Water Emulsion Constructed from Tremella Polysaccharide and Citrus Pectin

The objective of this study was to investigate the feasibility of the mixture of tremella polysaccharide (TP) and citrus pectin (CP) as an emulsifier by evaluating its emulsifying ability/stability. The results showed that the TP:CP ratio of 5:5 (w/w) could effectively act as an emulsifier. CP, owing its lower molecular weight and highly methyl esterification, facilitated the emulsification of oil droplets, thereby promoting the dispersion of droplets. Meanwhile, the presence of TP enhanced the viscosity of emulsion system and increased the electrostatic interactions and steric hindrance, therefore hindering the migration of emulsion droplets, reducing emulsion droplets coalesce, and enhancing emulsion stability. The emulsification and stabilization performances were influenced by the molecular weight, esterified carboxyl groups content, and electric charge of TP and CP, and the potential mechanism involved their impact on the buoyant force of droplet size, viscosity, and steric hindrance of emulsion system. The emulsions stabilized by TP-CP exhibited robust environmental tolerance, but demonstrated sensitivity to Ca2+. Conclusively, the study demonstrated the potential application of the mixture of TP and CP as a natural polysaccharide emulsifier.

Antimicrobial activity and structure-activity relationships of molecules containing mono- or di- or oligosaccharides: An update

Bacterial infections are the second leading cause of death worldwide, and the evolution and widespread distribution of antibiotic-resistance elements in bacterial pathogens exacerbate the threat crisis. Carbohydrates participate in bacterial infection, drug resistance and the process of host immune regulation. Numerous antimicrobials derived from carbohydrates or contained carbohydrate scaffolds that are conducive to an increase in pathogenic bacteria targeting, the physicochemical properties and druggability profiles. In the paper, according to the type and number of sugar residues contained in antimicrobial molecules collected from the literatures ranging from 2014 to 2024, the antimicrobial activities, action mechanisms and structure-activity relationships were delineated and summarized, for purpose to provide the guiding template to select the type and size of sugars in the design of oligosaccharide-based antimicrobials to fight the looming antibiotic resistance crisis.

Supplementation of citrus pectin with whole-cell pectinase PG5 on Pichia pastoris promotes recovery of colitis and enhances intestinal barrier function in DSS-treated mice

A whole-cell biocatalyst was developed by genetically engineering pectinase PG5 onto the cell surface of Pichia pastoris using Gcw12 as the anchoring protein. Whole-cell PG5 eliminated the need for enzyme extraction and purification, while also exhibiting enhanced thermal stability, pH stability, and resistance to proteases in vitro compared to free PG5. Magnetic resonance mass spectrometry analysis revealed that whole-cell PG5 efficiently degraded citrus pectin, resulting in the production of a mixture of pectin oligosaccharides. The primary components of the mixture were trigalacturonic acid, followed by digalacturonic acid and tetragalacturonic acid. Supplementation of citrus pectin with whole-cell PG5 resulted in a more pronounced protective effect compared to free PG5 in alleviating colitis symptoms and promoting the integrity of the colonic epithelial barrier in a mouse model of dextran sulfate sodium-induced colitis. Hence, this study demonstrates the potential of utilizing whole-cell pectinase as an effective biocatalyst to promote intestinal homeostasis in vivo.

Insights into the impact of modification methods on the structural characteristics and health functions of pectin: A comprehensive review

Pectin is a complex polysaccharide that is widely present in plant cells and has multiple physiological functions. However, most pectin exists in the form of protopectin, which has a large molecular weight and cannot be fully absorbed and utilized in the human gut to exert its effects. The significant differences in the structure of different sources of pectin also limited their application in the food and medical fields. In order to achieve greater development and utilization of pectin functions, this paper reviewed several commonly used methods for pectin modification from physical, chemical, and biological perspectives, and elaborated on the relationship between these modification methods and the structure and functional properties of pectin. At the same time, the functional characteristics of modified pectin and its application in medical health, such as regulating intestinal health, anticancer, anti-inflammatory, and drug transport, were reviewed, so as to provide a theoretical basis for targeted modification of pectin and the development of new modified pectin products.

Polysaccharides regulate Th1/Th2 balance: A new strategy for tumor immunotherapy

T helper (Th) cells have received extensive attention owing to their indispensable roles in anti-tumor immune responses. Th1 and Th2 cells are two key subsets of Th cells that exist in relative equilibrium through the secretion of cytokines that suppress their respective immune response. When the type of cytokine in the tumor microenvironment is altered, this equilibrium may be disrupted, leading to a shift from Th1 to Th2 immune response. Th1/Th2 imbalance is one of the decisive factors in the development of malignant tumors. Therefore, focusing on the balance of Th1/Th2 anti-tumor immune responses may enable future breakthroughs in cancer immunotherapy. Polysaccharides can regulate the imbalance between Th1 and Th2 cells and their characteristic cytokine profiles, thereby improving the tumor immune microenvironment. To our knowledge, this study is the most comprehensive assessment of the regulation of the tumor Th1/Th2 balance by polysaccharides. Herein, we systematically summarized the intrinsic molecular mechanisms of polysaccharides in the regulation of Th1 and Th2 cells to provide a new perspective and potential target drugs for improved anti-tumor immunity and delayed tumor progression.

microRNA-92b-3p augments colon cancer development through inhibiting KLF3

Colon cancer (CC) is a tumor of the large intestine. miR-92b-3p is often deregulated in the tumorigensis. Here, the role of miR-92b-3p in the development of CC was investigated. miR-92b-3p and Kruppel-like factor 3 (KLF3) expression was examined in CC tissues and cells. miR-92b-3p inhibitor or KLF3 overexpression vector was transfected into CC cells, respectively to observe its role in CC cell proliferation, invasion, migration, and apoptosis. The targeting relationship between miR-92b-3p and KLF3 was validated. Meanwhile, rescue experiments were performed by co-transfection of miR-92b-3p inhibitor and KLF3 siRNA, followed by determining CC cell proliferation, invasion, migration, and apoptosis. Higher miR-92b-3p and lower KLF3 expression levels were observed in CC tissues and cells. miR-92b-3p inhibition or KLF3 overexpression reduced proliferation, invasion, and migration whereas induced apoptosis of CC cells. KLF3 was validated to be the target gene of miR-92b-3p. Depletion of KLF3 could reverse the antitumor role of miR-92b-3p inhibition in CC cells. miR-92b-3p augments CC development through inhibiting KLF3, which may confers a novel way to develop future treatment target.

Complete genome sequence of pectin-degrading Flavobacteriaceae bacterium GSB9

Pectic oligosaccharides, which are considered to be potential prebiotics, may be generated by pectin-degrading enzymes. Here, we report the complete genome sequence of the pectin-degrading marine bacterium, Flavobacteriaceae bacterium GSB9, which was isolated from seawater of South Korea. The complete genome sequence revealed that the chromosome was 3,630,376 bp in size, had a G + C content of 36.6 mol%, and was predicted to encode 3100 protein-coding sequences (CDSs), 40 tRNAs, and six 16S-23S-5S rRNAs. Genome sequence analysis revealed that this strain possesses multiple genes predicted to encode pectin-degrading enzymes. Our analysis may facilitate the future application of this strain against pectin in various industries.

Unveiling Plant-Based Pectins: Exploring the Interplay of Direct Effects, Fermentation, and Technological Applications in Clinical Research with a Focus on the Chemical Structure

Pectin, a plant-derived polysaccharide, possesses immense technological and biological application value. Several variables influence pectin's physicochemical aspects, resulting in different fermentations, interactions with receptors, and other functional properties. Some of those variables are molecular weight, degree of methylation and blockiness, and monosaccharide composition. Cancer cell cytotoxicity, important fermentation-related byproducts, immunomodulation, and technological application were found in cell culture, animal models, and preclinical and clinical assessments. One of the greater extents of recent pectin technological usage involves nanoencapsulation methods for many different compounds, ranging from chemotherapy and immunotherapy to natural extracts from fruits and other sources. Structural modification (modified pectin) is also utilized to enhance the use of dietary fiber. Although pectin is already recognized as a component of significant importance, there is still a need for a comprehensive review that delves into its intricate relationships with biological effects, which depend on the source and structure of pectin. This review covers all levels of clinical research, including cell culture, animal studies, and clinical trials, to understand how the plant source and pectin structures influence the biological effects in humans and some technological applications of pectin regarding human health.

Recent advances in polygalacturonase: Industrial applications and challenges

This review focuses on the applications of polygalacturonase (PG), one of the most commercially produced enzymes on the biocatalyst market, in the food, beverage, feed, textile, and paper industries. Most PGs are acidic mesophilic enzymes, as shown by a summary of their biochemical properties. However, the acidic PGs discovered to date are insufficiently effective for industrial applications. The sequence and structural characteristics of thermophilic PGs are analyzed based on the results of extensive discussions regarding the catalytic mechanism and structural characteristics of PGs with shared right-handed parallel β-helical structures. In addition, the molecular modification methods for obtaining thermostable PGs are systematically presented. Notably, the demand for alkaline heat-resistant PGs has increased significantly concurrent with the biomanufacturing industry development. Therefore, this review also provides a theoretical guideline for mining heat-resistant PG gene resources and modifying PG thermostability.

Structure characteristics of low molecular weight pectic polysaccharide and its anti-aging capability by modulating the intestinal homeostasis

Pectic polysaccharide has attracted increasing attention for their potential biological properties and applications in health industries. In this study, a low-molecular-weight pectic polysaccharide, POS4, was obtained from citrus peel. The structure of POS4 was preliminarily analyzed by gel-permeation chromatography, monosaccharide analysis, infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Results showed that the molecular weight of POS4 was 4.76 kDa and it was a galacturonic acid enriched pectic polysaccharide. The anti-aging activity in vivo showed that POS4 could notably prolong the average lifespan of fruit flies by suppressing the generation of reactive oxygen species (ROS). Further studies demonstrated that POS4 could enhance intestinal homeostasis by modulating gut microbiota in a positive way and regulating autophagy associated genes. Taken together, we proposed that galacturonic acid enriched low molecular weight pectic polysaccharide have great potential in the development of healthy foods such as anti-aging health care products.

Chitosan and Pectin Hydrogels for Tissue Engineering and In Vitro Modeling

Hydrogels are fascinating biomaterials that can act as a support for cells, i.e., a scaffold, in which they can organize themselves spatially in a similar way to what occurs in vivo. Hydrogel use is therefore essential for the development of 3D systems and allows to recreate the cellular microenvironment in physiological and pathological conditions. This makes them ideal candidates for biological tissue analogues for application in the field of both tissue engineering and 3D in vitro models, as they have the ability to closely mimic the extracellular matrix (ECM) of a specific organ or tissue. Polysaccharide-based hydrogels, because of their remarkable biocompatibility related to their polymeric constituents, have the ability to interact beneficially with the cellular components. Although the growing interest in the use of polysaccharide-based hydrogels in the biomedical field is evidenced by a conspicuous number of reviews on the topic, none of them have focused on the combined use of two important polysaccharides, chitosan and pectin. Therefore, the present review will discuss the biomedical applications of polysaccharide-based hydrogels containing the two aforementioned natural polymers, chitosan and pectin, in the fields of tissue engineering and 3D in vitro modeling.

Fortified milk-beverage with amphora algae and its functionality for aflatoxin inactivation in rats

Aflatoxins are considered a severe hazard, contaminate dietary products, and cause malignant alterations in liver tissues. Fermented milk (FM) is prepared using probiotic lactic acid strains. This investigation aimed to produce an integrated milk beverage, inactivating aflatoxins toxicity and biotransformation. The proximate analysis of the investigated materials and biochemical parameter changes of the in-vivo experiment were determined. Results reflected the extract’s valuable content of polysaccharides and antioxidants. Nine phenolics were identified predominantly with catechin (39.67 ± 1.5 µg/g). FM-fortification is reflected by enhancement in protein (49.5 ± 2.97 g/Kg) and fiber content (1.78 ± 0.54 g/Kg) compared to the FM content. Relative rats’ weight gain improved to 34.29% for the fortified-FM group close to the control; it was recorded at 16.47% for the AFM1 group. Alkaline phosphatase in AFM1 rats was 99.2 ± 1.86 U/L and decreased to 44.2 ± 0.71 U/L in the fortified-FM group (44.2 ± 0.71 U/L) to be close to the control group. Aflatoxin M1 rats exposure reflects tissue alterations and cell damage, which recorded lesser in rats treated by extract and beverage administrations. The beverage’s corrective action relied on two integrated mechanisms, aflatoxin-binding to bacterial and bioactivity interaction of extract substances. This beverage stopped tissue alterations that occurred due to aflatoxins. The result supports the future production of fortified-milk beverages as a bio-shield against aflatoxin toxicity, besides their nutritional and functional properties.

Notch signaling-induced cyclin d1 in diabetes ameliorating effects of the isolated polysaccharide from Rosa canina: In vitro and in vivo studies

Notch signaling has a role in the expansion of the pancreas and the pathogenesis of diabetes. Modulation of Notch signaling by natural products seems to pave the way for treating diabetes. This research aimed to scrutinize the involvement of the Notch cascade in the diabetes-ameliorating effects of an isolated polysaccharide from Rosa canina. The isolated polysaccharide was characterized using Fourier transform infrared, nuclear magnetic resonance, high-performance gel-permeation chromatography, and liquid chromatography with tandem mass spectrometry techniques. Rat pancreatic β cells and STZ-induced diabetic rats were treated with the isolated polysaccharide. MTT assay, cell cycle analysis, quantative realtime-polymerase chain reaction, immunohistochemistry, and immunoblotting were used to reveal the growth and the expression levels of Notch1, DLL4, Jagged-1, hes1, Ins-1, Pdx-1, and cyclin d1 in treated and untreated pancreatic cells and tissues. The ameliorating effect of the polysaccharide in STZ-treated cells was accomplished by upregulation of cyclin d1 and hes1 as well as cell cycle progression. Notch inhibition by LY-411575 was associated with the downregulation of cyclin d1 which upregulates with polysaccharide treatment. The significant expression of cyclin d1 (90%) and nuclear expression of hes1 in the pancreas of the polysaccharide group were accompanied by improvement of hyperglycemia and associated biochemical factors as well as regeneration of islet cells as compared to untreated diabetic rats. Based on these findings, upregulation of Notch signaling-induced cyclin d1 could be proposed as the underlying diabetes-reducing effects of the isolated polysaccharide derivative implying that cyclin d1 actuation through activation of the Notch-DLL4 circuit may play the causal role in the treatment of diabetes.

Anti-melanogenesis effect from Wampee fruit pectin via α-MSH/TRY pathway in A375 cells

Background

Polysaccharides from wampee have been reported to process various biological activities, while the relationship between structure and bioactivities has been barely addressed. Pectin, an abundant water-soluble polysaccharide in wampee, showed significant antioxidant activity, which was associated with the anti-melanogenic activity. Therefore, this study investigated the physicochemical characteristics and the anti-melanogenesis effect of pectin extracted from wampee fruit in A375 cells.

Methods

The physicochemical characterization of pectin from wampee fruit was investigated by gel chromatography (GCP), FT-IR spectroscopy, and NMR spectroscopy methods. The anti-melanogenesis effects and mechanism were evaluated by mushroom tyrosine enzyme and human melanin cell model in vitro.

Results

The results showed that a molecular weight of 5.271 × 10⁵ Da wampee fruit pectin (WFP) were mainly composed of mannose (Man), ribose (Rib), rhamnose (Rha), glucuronic acid (Glc A), glucose (Glc), galacturonic acid (Gal A), galactose (Gal), and arabinose (Ara), which linked with →4)-β-D-Galp-(1 → units. The current study revealed that WFP could significantly suppress mushroom TRY activity in vitro. Furtherly, WFP significantly reduced intracellular and extracellular melanin formation in A375 melanoma cells depending on the presence of alpha-melanocyte stimulating hormone (α-MSH). TRY activity was only inhibited in α-MSH treated A375 cells. Western blot analysis demonstrated that WFP reverse α-MSH induced melanogenesis in A375 melanoma cells, including in down-regulated TRY, TYRP-1, TYRP-2, MITF and CREB expressions.

Conclusion

These results indicated that WFP could inhibit α-MSH induced melanogenesis in A375 melanoma cells via α-MSH/TRY pathway. In conclusion, these data provided a new perspective to annotate WFP anti-melanogenesis activity mechanism.

Mechanism and Antibacterial Activity of Gold Nanoparticles (AuNPs) Functionalized with Natural Compounds from Plants

Recently, the biosynthesis of gold nanoparticles (AuNPs) has been widely studied and described. In the age of bacterial drug resistance, an intensive search for new agents with antibacterial properties or a new form of antibiotics with effective action is necessary. As a result, the antibacterial activity of AuNPs functionalized with natural compounds is being investigated more frequently. AuNPs biosynthesized with plant extract or functionalized with bioactive compounds isolated from plants could be particularly useful for pharmaceutical applications. The biosynthesized AuNPs are stabilized by an envelope, which may consist of flavonoids, phenolic acids, lipids and proteins as well as carbohydrates and vitamins. The composition of the natural coating affects the size, shape and stability of the AuNPs and is also responsible for interactions with the bacterial cell wall. Recently, several mechanisms of AuNP interactions with bacterial cells have been identified. Nevertheless, they are not yet well understood, due to the large diversity of plants and biosynthesized AuNPs. Understanding the antibacterial mechanisms allows for the creation of pharmaceutical formulations in the most useful form. Utilizing AuNPs functionalized with plant compounds as antibacterial agents is still a new concept. However, the unique physicochemical and biological properties of AuNPs emphasises their potential for a broad range of applications in the future.

The impact of dietary fibers on Clostridioides difficile infection in a mouse model

Diets rich in fiber may provide health benefits and regulate the gut microbiome, which affects the immune system. However, the role of dietary fiber in Clostridioides difficile infection (CDI) is controversial. Here, we investigated the use of fermentable fibers, such as inulin or pectin, to replace the insoluble fiber cellulose to explore how dietary fiber affects C. difficile-induced colitis in mice through intestinal microecology and metabolomics. Using C. difficile VPI 10463, we generated a mouse model of antibiotic-induced CDI. We evaluated disease outcomes and the microbial community among mice fed two fermentable fibers (inulin or pectin) versus the insoluble fiber cellulose. We analyzed and compared the gut microbiota, intestinal epithelium, cytokine levels, immune responses, and metabolites between the groups. Severe histological injury and elevated cytokine levels were observed in colon tissues after infection. Different diets showed different effects, and pectin administration protected intestinal epithelial permeability. Pectin also steadily increased the diversity of the microbiome and decreased the levels of C. difficile-induced markers of inflammation in serum and colonic tissues. The pectin group showed a higher abundance of Lachnospiraceae and a lower abundance of the conditionally pathogenic Enterobacteriaceae than the cellulose group with infection. The concentration of short-chain fatty acids in the cecal contents was also higher in the pectin group than in the cellulose group. Pectin exerted its effects through the aryl hydrocarbon receptor (AhR) pathway, which was confirmed by using the AhR agonist FICZ and the inhibitor CH2223191. Our results show that pectin alters the microbiome and metabolic function and triggers a protective immune response.

Antiaging Effects of Dietary Polysaccharides: Advance and Mechanisms

Aging is a process in which the various physiological functions of the body gradually deteriorate and eventually lead to death. During this process, the body’s resistance to external stresses gradually decreases and the aging-related diseases gradually are increased. Polysaccharides are a group of active substances extracted from living organisms and are widely found in plants, animals, and microorganisms. In the last decade, a variety of natural polysaccharides from functional and medicinal foods have attracted considerable interest for their beneficial effects in the prevention of chronic diseases such as cancers, diabetes, and neurodegenerative diseases. Interestingly, these polysaccharides have also been found to delay aging by reducing oxidative damage, inhibiting telomere shortening, and being anti-inflammatory in different animal models of aging. These reviews summarized the progresses in effects of polysaccharides on antiaging and the potential mechanisms and especially focused on the signaling pathways involved in the antiaging functions. Finally, the applications and prospects of the antiaging effects of polysaccharides are discussed.

The Use of Endo-Cellulase and Endo-Xylanase for the Extraction of Apple Pectins as Factors Modifying Their Anticancer Properties and Affecting Their Synergy with the Active Form of Irinotecan

Pectin constitutes an essential component of dietary fiber. Modified pectins from various sources possess potent anticancer and immunomodulatory activities. In this study, two pectins isolated from apple pomace by Trichoderma enzyme treatment, PX (with endo-xylanase) and PCX (with both endo-cellulase and endo-xylanase), were studied in colon cancer cell lines (HCT 116, Caco-2, and HT-29). Both pectins reduced colon cancer cell viability, induced apoptosis, and increased intracellular amounts of reactive oxygen species. Additionally, synergy between pectin and an active form of irinotecan, SN-38, in all aspects mentioned above, was discovered. This drug is a common component of cytotoxic combinations recommended as treatment for colon cancer patients. PX and PCX demonstrated significant anti-inflammatory activity in lipopolysaccharide-stimulated cells. Interaction of apple pectins with galectin-3 and Toll-like Receptor 4 (TLR4) was suggested to be responsible for their anticancer and anti-inflammatory effect. Since PCX was more active than PX in almost all experiments, the role of the enzyme used to obtain the pectin for its biological activity was discussed. It was concluded that co-operation between both enzymes was needed to obtain the molecule of the most beneficial properties. The low molecular mass of PCX together with a high proportion of rhamnogalacturonan I (RG I) regions seemed to be crucial for its superior activity.

The Anti-Cancer Effects of Red-Pigmented Foods: Biomarker Modulation and Mechanisms Underlying Cancer Progression

Cancer is one the most malignant diseases that is a leading cause of death worldwide. Vegetables and fruits contain beneficial nutrients such as vitamins, minerals, folates, dietary fibers, and various natural bioactive compounds. These can prevent the pathological processes of many cancers and reduce cancer related mortality. Specifically, the anti-cancer effect of vegetables and fruits is largely attributable to the natural bioactive compounds present within them. A lot of bioactive compounds have very specific colors with pigments and the action of them in the human body varies by their color. Red-pigmented foods, such as apples, oranges, tomatoes, cherries, grapes, berries, and red wine, have been widely reported to elicit beneficial effects and have been investigated for their anti-tumor, anti-inflammatory, and antioxidative properties, as well as anti-cancer effect. Most of the anti-cancer effects of bioactive compounds in red-pigmented foods arise from the suppression of cancer cell invasion and metastasis, as well as the induction of apoptosis and cell cycle arrest. In this review, we assessed publications from the last 10 years and identified 10 bioactive compounds commonly studied in red-pigmented foods: lycopene, anthocyanin, β-carotene, pectin, betaine, rutin, ursolic acid, kaempferol, quercetin, and myricetin. We focused on the mechanisms and targets underlying the anti-cancer effect of the compounds and provided rationale for further investigation of the compounds to develop more potent anti-cancer treatment methods.

Taurine loaded chitosan-pectin nanoparticle shows curative effect against acetic acid-induced colitis in rats

Owing to the poor outcomes and adverse side effects of existing ulcerative colitis drugs, the study aimed to develop an alternative nano-based treatment approach. The study was designed to characterize the in vitro and in vivo properties of taurine, taurine-loaded chitosan pectin nanoparticles (Tau-CS-PT-NPs) and chitosan pectin nanoparticles (CS-PT-NPs) in the therapy of acetic acid (AA)-induced colitis in rats. CS-PT-NPs and Tau-CS-PT-NPs were prepared by ionic gelation method then in vitro characterized, including transmission electron microscopy (TEM), polydispersity index (PDI), zeta potential, Fourier transform infrared (FTIR) spectroscopy, encapsulation efficiency (EE), and drug release profile. Following colitis induction, rats were orally administrated with free taurine, Tau-CS-PT-NPs, and CS-PT-NPs once per day for six days. The sizes of Tau-CS-PT-NPs and CS-PT-NPs were 74.17 ± 2.88 nm and 42.22 ± 2.41 nm, respectively. EE was about 69.09 ± 1.58%; furthermore, 60% of taurine was released in 4 h in simulated colon content. AA-induced colitis in untreated rats led to necrosis of colon tissues and a significant increase in interleukin-1beta (IL-1β), Tumor Necrosis Factor-alpha (TNF-α), myeloperoxidase (MPO), and malondialdehyde (MDA) levels associated with a remarkable reduction in glutathione (GSH) level in colon tissue in comparison to control group. Treatment with taurine, Tau-CS-PT-NPs, and CS-PT-NPs partly reversed these effects. The present study demonstrated that the administration of free taurine, CS-PT-NPs, and Tau-CS-PT-NPs exerted beneficial effects in acetic acid-induced colitis by their anti-inflammatory and antioxidant activities. The best therapeutic effect was observed in animals treated with taurine-loaded chitosan pectin nanoparticles.

Anti-Cancer Pectins and Their Role in Colorectal Cancer Treatment

A class of plant polysaccharides, pectin is known to display several medicinal properties including in cancer. There is some evidence that pectin from some fruits can reduce the severity of colorectal cancer (CRC) due to its antiproliferative, anti-inflammatory, antimetastatic and pro-apoptotic properties. Pectin fermentation in the colon induces antiproliferative activity via butyrate. Research also showed that pectin acts as a potent inducer of programmed cell death and cell-cycle arrest, thereby selectively targeting cancer cells. Pectin can limit oxidative stress to maintain cellular homeostasis while increasing reactive oxygen species damage to activate cancer cell death. Pectin regulates various signaling cascades, e.g., signal transduction and transcriptional activator and mitogen-activated protein kinase signaling, that contribute to its anticancer activity. By curbing inflammation-activated signaling and bolstering immune-protective mechanisms pectin can eradicate CRC. Due to its chemical structure, pectin can also inhibit galectin-3 and suppress tumor growth and metastasis. Prior reports also suggested that pectin is beneficial to use alongside the CRC standard care. Pectin can increase sensitivity to conventional CRC drugs, alleviate unwanted side effects and reduce drug resistance. Although some preclinical studies are promising, early clinical trials are showing some evidence for pectin's efficacy in tumor growth inhibition and preventing metastasis in some cancers; however, the clinical use of pectin in CRC therapy is not yet well established. Further studies are needed to confirm the efficacy of pectin treatment as a valid clinical therapy for CRC in humans.

Effects of pectins on colorectal cancer: targeting hallmarks as a support for future clinical trials

The intake of dietary fibers has been associated with a reduction in the risk of colorectal cancer.

Protective role of nutraceuticals against myocarditis

Myocarditis is an inflammatory disease of the myocardium that mostly affects young adults. The disease is commonly caused by viral infection, medications, autoimmune disorders, and inflammatory conditions. Nearly 50% of the cases of myocarditis are due to post-viral immune response in a setting of an identifiable or non-identifiable infection. The clinical manifestation is nonspecific ranging from asymptomatic courses to sudden death in infants and young patients. This review describes the properties of phytochemicals as plant-derived active ingredients which can be used in the prevention and treatment of myocarditis and its associated risk factors. Meanwhile, it has illustrated epidemiological analyses, mechanism of action, and the metabolism of phytochemicals in animal and human clinical trials. We also mentioned the precise mechanism of action by which phytochemicals elicit their anti-viral, anti-inflammatory, antioxidant, and immunomodulatory effects and how they regulate signal transduction pathways. Nevertheless, comprehensive clinical trials are required to study the properties of phytochemicals in vivo, in vitro, and in silico for a proper management of myocarditis. Our findings indicate that phytochemicals function as potent adjunctive therapeutic drugs in myocarditis and its related complications.

Pectin Oligosaccharides Enhance α2,6-Sialylation Modification that Promotes Apoptosis of Bladder Cancer Cells by Targeting the Hedgehog Pathway

Although pectin oligosaccharide (POS) can inhibit the growth and proliferation of gastric, colon, prostate, breast, melanoma, and leukemia cells, its effect on bladder cancer remains unknown. Therefore, screening and identification of factors associated with the sensitivity of bladder cancer to drugs and elucidation of their molecular mechanisms will help provide a theoretical basis for establishing postoperative systemic chemotherapy for patients with bladder cancer. We showed that POS promoted the apoptosis of bladder cancer cells, and this finding was consistent with enhanced α2,6-sialylation post-modification. Moreover, POS activated the Hedgehog pathway, the inhibition of which regulated the tumorigenicity of bladder cancer cells in vivo. These findings were consistent with our results in vitro. We conclude that POS promotes the apoptosis of bladder cancer and offers new insights and evidence for the development of individualized treatment strategies. Schema of molecular events underlying POS-induced inhibition of bladder cancer cell proliferation.

Green synthesis of metallic nanoparticles using pectin as a reducing agent: a systematic review of the biological activities

CONTEXT

Pectin is a plant heteropolysaccharide that is biocompatible and biodegradable, enabling it to be an excellent reducing agent (green synthesis) for metallic nanoparticles (MNPs). Nevertheless, in the biological industry, pectin has been left behind in synthesising MNPs, for no known reason.

OBJECTIVE

To systematically review the biological activities of pectin synthesised MNPs (Pe-MNPs).

METHODS

The databases Springer Link, Scopus, ScienceDirect, Google Scholar, PubMed, Mendeley, and ResearchGate were systematically searched from the date of their inception until 10^th February 2020. Pectin, green synthesis, metallic nanoparticles, reducing agent and biological activities were among the key terms searched. The data extraction was focussed on the biological activities of Pe-MNPs and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations for systematic reviews.

RESULTS

A total of 15 studies outlined 7 biological activities of Pe-MNPs in the only three metals that have been explored, namely silver (Ag), gold (Au) and cerium oxide (CeO₂). The activities reported from the in vitro and in vivo studies were antimicrobial (9 studies), anticancer (2 studies), drug carrier (3 studies), non-toxic (4 studies), antioxidant (2 studies), wound healing (1 study) and anti-inflammation (1 study).

CONCLUSIONS

This systematic review demonstrates the current state of the art of Pe-MNPs biological activities, suggesting that Ag and Au have potent antibacterial and anticancer/chemotherapeutic drug carrier activity, respectively. Further in vitro, in vivo, and clinical research is crucial for a better understanding of the pharmacological potential of pectin synthesised MNPs.

Dialdehyde pectin-crosslinked and hirudin-loaded decellularized porcine pericardium with improved matrix stability, enhanced anti-calcification and anticoagulant for bioprosthetic heart valves

To conveniently and effectively cure heart valve diseases or defects, combined with transcatheter valve technology, bioprosthetic heart valves (BHVs) originated from the decellularized porcine pericardium (D-PP) have been broadly used in clinics. Unfortunately, most clinically available BHVs crosslinked with glutaraldehyde (GA) were challenged in their long-term tolerance, degenerative structural changes, and even failure, owing to the synergistic impact of multitudinous elements (cytotoxicity, calcification, immune responses, etc.). In this work, dialdehyde pectin (AP) was prepared by oxidizing the o-dihydroxy of pectin with sodium periodate. Hereafter, the AP-fixed PP model was obtained by crosslinking D-PP with AP with high aldehyde content (6.85 mmol g^-1), for acquiring excellent mechanical properties and outstanding biocompatibility. To further improve the hemocompatibility of the AP-fixed PP, a natural and specific inhibitor of thrombin (hirudin) was introduced to achieve surface modification of the AP-fixed PP. The feasibility of crosslinking and functionalizing AP-fixed PP, which was a potential leaflet material of BHVs, was exhaustively and systematically evaluated. In vitro studies found that hirudin-loaded and AP-fixed PP (AP + Hirudin-PP) had synchronously achieved effective fixation of collagen, highly effective anticoagulation, and good HUVECs-cytocompatibility. In vivo results revealed that the AP + Hirudin-PP specimens recruited the minimum immune cells in the implantation experiment, and also presented an excellent anti-calcification effect. Overall, AP + Hirudin-PP was endowed with competitive collagen stability (compared with GA-fixed PP), excellent hemocompatibility, good HUVECs-cytocompatibility, low immunogenicity and outstanding anti-calcification, suggesting that AP + Hirudin-PP might be a promising alternative to GA-fixed PP and exhibited a bright prospect in the clinical applications of BHVs.

Recent advances in utilization of pectins in biomedical applications: a review focusing on molecular structure-directing health-promoting properties

The numerous health benefits of pectins justify their inclusion in human diets and biomedical products. This review provides an overview of pectin extraction and modification methods, their physico-chemical characteristics, health-promoting properties, and pharmaceutical/biomedical applications. Pectins, as readily available and versatile biomolecules, can be tailored to possess specific functionalities for food, pharmaceutical and biomedical applications, through judicious selection of appropriate extraction and modification technologies/processes based on green chemistry principles. Pectin's structural and physicochemical characteristics dictate their effects on digestion and bioavailability of nutrients, as well as health-promoting properties including anticancer, immunomodulatory, anti-inflammatory, intestinal microflora-regulating, immune barrier-strengthening, hypercholesterolemia-/arteriosclerosis-preventing, anti-diabetic, anti-obesity, antitussive, analgesic, anticoagulant, and wound healing effects. HG, RG-I, RG-II, molecular weight, side chain pattern, and degrees of methylation, acetylation, amidation and branching are critical structural elements responsible for optimizing these health benefits. The physicochemical characteristics, health functionalities, biocompatibility and biodegradability of pectins enable the construction of pectin-based composites with distinct properties for targeted applications in bioactive/drug delivery, edible films/coatings, nano-/micro-encapsulation, wound dressings and biological tissue engineering. Achieving beneficial synergies among the green extraction and modification processes during pectin production, and between pectin and other composite components in biomedical products, should be key foci for future research.

A Scientometric Visualization Analysis for Natural Products on Cancer Research from 2008 to 2020

Background: An increasing number of studies have shown that natural products have anti-tumor effects, and it has become a hotspot in cancer research. However, few bibliometric analyses have been examined in this field systematically. The current study aimed to explore the status and provide the developing trends in the natural products on cancer research.

Methods: Publications on natural products in cancer research were extracted from the Web of Science core collection database. CiteSpace (5.6.R3) software and GraphPad prism 6 were used to analyze and plot the references.

Results: On February 1, 2021, 34,611 records of natural products in cancer research published from 2008 to 2020 were collected. The United States was the driving force, with a strong academic reputation in this area. The top-contributing institution was the Chinese Academy of Sciences. Most publications were published in Molecules. Efferth Thomas was the most prolific author, while Newman DJ was the most cited and frequently co-cited author. Flavonoid, curcumin, and polyphenol were the most widely studied natural products. Oleanolic acid and rosmarinic acid have gradually become research hotspots recently. Breast cancer, prostate cancer, and colorectal cancer were the most common types of cancer in this field. “Natural killer cell” was the leading research hotspot. The keywords of “leaf extract,” “molecular docking” and “gold nanoparticle” appeared most recently as research frontiers.

Conclusion: Our results provided a general overview of the major research directions of natural products research in cancer. The mechanisms of natural products, especially those related to molecular docking, gold nanoparticle, gut microbiota, and immune checkpoints may soon become hotspots and should be closely monitored.

The Athlete and Gut Microbiome: Short-chain Fatty Acids as Potential Ergogenic Aids for Exercise and Training

Short-chain fatty acids (SCFAs) are metabolites produced in the gut via microbial fermentation of dietary fibers referred to as microbiota-accessible carbohydrates (MACs). Acetate, propionate, and butyrate have been observed to regulate host dietary nutrient metabolism, energy balance, and local and systemic immune functions. In vitro and in vivo experiments have shown links between the presence of bacteria-derived SCFAs and host health through the blunting of inflammatory processes, as well as purported protection from the development of illness associated with respiratory infections. This bank of evidence suggests that SCFAs could be beneficial to enhance the athlete's immunity, as well as act to improve exercise recovery via anti-inflammatory activity and to provide additional energy substrates for exercise performance. However, the mechanistic basis and applied evidence for these relationships in humans have yet to be fully established. In this narrative review, we explore the existing knowledge of SCFA synthesis and the functional importance of the gut microbiome composition to induce SCFA production. Further, changes in gut microbiota associated with exercise and various dietary MACs are described. Finally, we provide suggestions for future research and practical applications, including how these metabolites could be manipulated through dietary fiber intake to optimize immunity and energy metabolism.

Challenges of pectic polysaccharides as a prebiotic from the perspective of fermentation characteristics and anti-colitis activity

Several studies are described that contribute to the systematic exploration of new aspects of digestion, fermentation, and biological activities of pectic polysaccharides (PPS) leading to a better understanding of prebiotics. Inflammatory bowel disease (IBD) is thought to be associated with the dysbacteriosis induced by different environmental agents in genetically susceptible persons. PPS are considered as an indispensable gut-microbiota-accessible carbohydrate that play a dominant role in maintaining gut microbiota balance and show a better effect in ameliorating IBD than some traditional prebiotics. The aim of this review is to summarize the fermentation characteristics of PPS, highlight its role in improving IBD, and propose a view that PPS may be a new and effective prebiotic.

Newly Obtained Apple Pectin as an Adjunct to Irinotecan Therapy of Colorectal Cancer Reducing E. coli Adherence and β-Glucuronidase Activity

Colorectal cancer (CRC) is the second cause of cancer death worldwide. The composition and enzymatic activity of colonic microbiota can significantly affect the effectiveness of CRC chemotherapy. Irinotecan is a drug widely used to treat colon cancer. However, the transformation of a drug-glucuronide (SN-38G) back to its active form (SN-38) by bacterial β-glucuronidase (GUS) constitutes the primary reason for the observed intestinal toxicity of irinotecan. It was demonstrated that novel enzymatically extracted apple pectin (PC) might be a promising candidate for an adjunct to irinotecan therapy. PC itself reduced the viability of HCT 116 and Caco-2 colorectal cancer cells, induced apoptosis, and increased intracellular reactive oxygen species production. Moreover, PC enhanced the cytotoxic and proapoptotic effect of irinotecan (at concentrations below its IC₅₀), i.e., synergistic effect was recorded. Additionally, PC exhibited potent anti-inflammatory properties and prevented adhesion of prototype adherent-invasive E. coli (AIEC) LF82 strain and laboratory K-12_C600 strain to colon cancer cells. PC was also identified to be an effective inhibitor of bacterial GUS activity. Altogether, novel apple pectin was identified as a promising candidate for a supplement to irinotecan therapy that might alleviate its side-effects via inhibition of bacterial GUS and thus increasing its therapeutic efficacy.

Characterization of an antioxidant pectic polysaccharide from Platycodon grandiflorus

Platycodonis Radix is widely used as homology of medicine and food in China; polysaccharides are thought to be one of its functional constituents. In this study, a pectic polysaccharide, PGP-I-I, was obtained from the root of the traditional medicine plant Platycodon grandiflorus through ion exchange chromatography and gel filtration. This was characterized being mainly composed of 1,5-α-L-arabinan and both arabinogalactan type I (AG-I) and II chains linked to rhamnogalacturonan I (RG-I) backbone linked to longer galacturonan chains. In vitro bioactivity study showed that PGP-I-I could restore the intestinal cellular antioxidant defense under the condition of hydrogen peroxide (H₂O₂) treatment through promoting the expressions of cellular antioxidant genes and protect against oxidative damages.

CircMRE11A_013 binds to UBXN1 and integrates ATM activation enhancing lens epithelial cells senescence in age-related cataract

Ultraviolet B (UVB) irradiation could trigger DNA double-strand breaks (DDSBs) and senescence in lens epithelial cells (LECs), thus inducing age-related cortical cataract (ARCC) formation. Cell-cycle irreversible arrest induced by DDSBs depended on excessive activation of ataxia-telangiectasia mutated kinase (ATM). We studied the up-regulated circular RNA circMRE11A_013 (circMRE11A) in LECs of ARCC and SRA01/04 cell lines under UVB exposure. In vitro, knockdown of circMRE11A in SRA01/04 cell lines enhanced cell viability and cell cycle, while over-expression of circMRE11A exhibited an opposite trend. Additionally, circMRE11A could bind to UBX domain-containing protein 1 (UBXN1), which might enhance excessive activation of ATM and initiate ATM/p53/p21 signaling pathway causing LECs cell-cycle arrest and senescence. In vivo, recombinant adeno-associated virus vectors (rAAV-2) virions of circMRE11A (circMRE11A-AAV2) was injected to Institute of Cancer Research mouse vitreous cavity. The circMRE11A-AAV2 could express in mouse lens at 4 weeks. The LECs aging and opacity lens were observed at 8 weeks after the injection. Together, our findings reveal a previously unidentified role of circMRE11A interacting with UBXN1 in enhancing ATM activity and inhibiting LECs cell-cycle in ARCC formation. The findings might give us a better understanding of ARC pathology and provide a novel and more effective therapeutic approaches for ARC treatment.

Enzymatic treatment, unfermented and fermented fruit-based products: current state of knowledge

In recent years, food manufacturers are increasingly utilizing enzymes in the production of fruit-based (unfermented and fermented) products to increase yield and maximize product quality in a cost-effective manner. Depending on the fruits and desired product characteristics, different enzymes (e.g. pectinase, cellulase, hemicellulase, amylase, and protease) are used alone or in combinations to achieve optimized processing conditions and improve nutritional and sensorial quality. In this review, the mechanisms of action and sources of different enzymes, as well as their effects on the physicochemical, nutritional, and organoleptic properties of unfermented and fermented fruit-based products are summarized and discussed, respectively. In general, the application of enzymatic hydrolysis treatment (EHT) in unfermented fruit-based product helps to achieve four main purposes: (i) viscosity reduction (easy to filter), (ii) clarification (improved appearance/clarity), (iii) better nutritional quality (increase in polyphenolics) and (iv) enhanced organoleptic characteristic (brighter color and complex aroma profile). In addition, EHT provides numerous other advantages to fermented fruit-based products such as better fermentation efficiency and enrichment in aroma. To meet the demand for new market trends, researchers and manufacturers are increasingly employing non-Saccharomyces yeast (with enzymatic activities) alone or in tandem with Saccharomyces cerevisiae to produce complex flavor profile in fermented fruit-based products. Therefore, this review also evaluates the potential of some non-Saccharomyces yeasts with enzymatic activities and how their utilization helps to tailor wines with unique aroma profile. Lastly, in view of an increase in lactose-intolerant individuals, the potential of fermented probiotic fruit juice as an alternative to dairy-based probiotic products is discussed.

Toll-like receptor 2-modulating pectin-polymers in alginate-based microcapsules attenuate immune responses and support islet-xenograft survival

Encapsulation of pancreatic islets in alginate-microcapsules is used to reduce or avoid the application of life-long immunosuppression in preventing rejection. Long-term graft function, however, is limited due to varying degrees of host tissue responses against the capsules. Major graft-longevity limiting responses include inflammatory responses provoked by biomaterials and islet-derived danger-associated molecular patterns (DAMPs). This paper reports on a novel strategy for engineering alginate microcapsules presenting immunomodulatory polymer pectin with varying degrees of methyl-esterification (DM) to reduce these host tissue responses. DM18-pectin/alginate microcapsules show a significant decrease of DAMP-induced Toll-Like Receptor-2 mediated immune activation in vitro, and reduce peri-capsular fibrosis in vivo in mice compared to higher DM-pectin/alginate microcapsules and conventional alginate microcapsules. By testing efficacy of DM18-pectin/alginate microcapsules in vivo, we demonstrate that low-DM pectin support long-term survival of xenotransplanted rat islets in diabetic mice. This study provides a novel strategy to attenuate host responses by creating immunomodulatory capsule surfaces that attenuate activation of specific pro-inflammatory immune receptors locally at the transplantation site.

An efficient protocol for the preparation of linear arabino-oligosaccharides

In this study, we report the development of an efficient protocol in the preparation of linear arabino-oligosaccharides derived from sugar beet arabinan. By optimizing hydrolytic conditions and separation on tandem Bio-Gel P4 columns, we obtained arabino-oligosaccharides with various degrees of polymerization (DP) from 2 to 15. All of these α-1,5-linked arabino-oligosaccharides are highly pure (>95%) as determined by HPAEC, MALDI-TOF mass spectrometry and ¹³C NMR spectroscopy. Due to their purity, these oligosaccharides can be used as standards to identify other oligosaccharides and as substrates to characterize new arabinan-specific enzymes, as well as for the development of new functional oligosaccharides.

Comparative Characterization of Aspergillus Pectin Lyases by Discriminative Substrate Degradation Profiling

Fungal genomes often contain several copies of genes that encode carbohydrate active enzymes having similar activity. The copies usually have slight sequence variability, and it has been suggested that the multigenecity represents distinct reaction optima versions of the enzyme. Whether the copies represent differences in substrate attack proficiencies of the enzyme have rarely been considered. The genomes of Aspergillus species encode several pectin lyases (EC 4.2.2.10), which all belong to polysaccharide lyase subfamily PL1_4 in the CAZy database. The enzymes differ in terms of sequence identity and phylogeny, and exhibit structural differences near the active site in their homology models. These enzymes catalyze pectin degradation via eliminative cleavage of the α-(1,4) glycosidic linkages in homogalacturonan with a preference for linkages between methyl-esterified galacturonate residues. This study examines four different pectin lyases (PelB, PelC, PelD, and PelF) encoded by the same Aspergillus sp. (namely A. luchuensis), and further compares two PelA pectin lyases from two related Aspergillus spp. (A. aculeatus and A. tubingensis). We report the phylogeny, enzyme kinetics, and enzymatic degradation profiles of the enzymes' action on apple pectin, citrus pectin, and sugar beet pectin. All the pectin lyases exerted highest reaction rate on apple pectin [degree of methoxylation (DM) 69%, degree of acetylation (DAc) 2%] and lowest reaction rate on sugar beet pectin (DM 56%, DAc 19%). Activity comparison at pH 5-5.5 produced the following ranking: PelB > PelA > PelD > PelF > PelC. The evolution of homogalacturonan-oligomer product profiles during reaction was analyzed by liquid chromatography with mass spectrometry (LC-MS) detection. This analyses revealed subtle differences in the product profiles indicating distinct substrate degradation preferences amongst the enzymes, notably with regard to acetyl substitutions. The LC-MS product profiling analysis thus disclosed that the multigenecity appears to provide the fungus with additional substrate degradation versatility. This product profiling furthermore represents a novel approach to functionally compare pectin-degrading enzymes, which can help explain structure-function relations and reaction properties of disparate copies of carbohydrate active enzymes. A better understanding of the product profiles generated by pectin modifying enzymes has significant implications for targeted pectin modification in food and biorefinery processes.