Citrus pectin attenuates endotoxin shock via suppression of Toll-like receptor signaling in Peyer's patch myeloid cells

Low methyl-esterified ginseng homogalacturonan pectins promote longevity of Caenorhabditis elegans via impairing insulin/IGF-1 signalling

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

Postbiotics-peptidoglycan, lipoteichoic acid, exopolysaccharides, surface layer protein and pili proteins-Structure, activity in wounds and their delivery systems

Chronic wound healing is a pressing global public health concern. Abuse and drug resistance of antibiotics are the key problems in the treatment of chronic wounds at present. Postbiotics are a novel promising strategy. Previous studies have reported that postbiotics have a wide range of biological activities including antimicrobial, immunomodulatory, antioxidant and anti-inflammatory abilities. However, several aspects related to these postbiotic activities remain unexplored or poorly known. Therefore, this work aims to outline general aspects and emerging trends in the use of postbiotics for wound healing, such as the production, characterization, biological activities and delivery strategies of postbiotics. In this review, a comprehensive overview of the physiological activities and structures of postbiotic biomolecules that contribute to wound healing is provided, such as peptidoglycan, lipoteichoic acid, bacteriocins, exopolysaccharides, surface layer proteins, pili proteins, and secretory proteins (p40 and p75 proteins). Considering the presence of readily degradable components in postbiotics, potential natural polymer delivery materials and delivery systems are emphasized, followed by the potential applications and commercialization prospects of postbiotics. These findings suggest that the treatment of chronic wounds with postbiotic ingredients will help provide new insights into wound healing and better guidance for the development of postbiotic products.

Oral Treatment with the Pectin Fibre Obtained from Yellow Passion Fruit Peels Worsens Sepsis Outcome in Mice by Affecting the Intestinal Barrier

The biological activities of plant-derived soluble dietary fibres (SDFs) have been widely investigated. Pectin from yellow passion fruit (YPF-peSDF) peels was suggested as a protective macromolecule in ulcers and colitis due to its antioxidant and anti-inflammatory properties. Sepsis has high mortality and morbidity and is characterised by inflammatory and oxidative stress imbalances. Evidence suggests that pectins may aid sepsis treatment; however, the effects of YPF-peSDF on sepsis remain unclear. Herein, polymicrobial sepsis was induced by cecal-ligation and puncture in mice treated with YPF-peSDF (1 and 10 mg/kg; gavage). YPF-peSDF accelerated mortality, reaching 100% in 24 h. Inflammation was present in the colons and small intestines (SI) of both vehicle- and fibre-treated mice. Although crypt depth and width, and villus height were preserved in the SI of septic mice administered YPF-peSDF, they exhibited exacerbated muscle layer atrophy and mucosa and submucosa hypertrophy, along with shortened enterocytes. Larger crypts and shorter enterocytes were noted in their colons in comparison with vehicle-controls. YPF-peSDF also reduced inflammatory cell numbers and exacerbated IL-6 levels in peritoneal lavage fluid (PELF) samples. YPF-peSDF modulated SI but not colon cytokines. Lipoperoxidation and antioxidant capacity levels were attenuated in PELF samples. Overall, in contrast to previous evidence, YPF-peSDF worsened polymicrobial sepsis outcomes in mice.

Hawthorn Fruit (Crataegus spp.) Polysaccharides Exhibit Immunomodulatory Activity on Macrophages via TLR4/NF-κB Signaling Activation

The immunostimulatory effects and the involved molecular mechanisms of polysaccharides from hawthorn fruit (Crataegus spp.) have not been well understood. In this study, the chemical composition, monosaccharide composition, uronic acid content, and structural features of hawthorn fruit polysaccharides (HFP) and the two collected fractions were analyzed. Both AF1-2 and AF2 have pectic-like structural features rich in galacturonic acid. AF2 showed superior proinflammatory effects on macrophages which significantly increased the secretion of pro-inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α, but not AF1-2. AF2 was found to activate the nuclear factor-κB signaling pathway with suppressed expression of IκBα but up-regulated expression of p-IκBα and nuclear factor-κB P65. The surface binding site of AF2 on macrophage cells was characterized and toll like receptor-4 was responsible for AF2 induced activation of down-stream nuclear factor-κB signaling pathways. AF2 from hawthorn fruit could be potentially used as a natural source of immunomodulator in functional foods.

A Gestational Pectin Diet Could Improve the Health of Multiparous Sows by Modulating the Gut Microbiota and Cytokine Level during Late Pregnancy

This study aimed to investigate the effects of the dietary fiber pectin on the gut microbiota and health of parturient sows. A total of 30 parity 5-7, multiparous gestation sows (Large White × Landrace) were randomly assigned to two treatment groups after mating: Con (control, basic diet) and Pec (pectin, 3%). The sows received the two diets during gestation, and all sows were fed the same standard basic diet during lactation. The results of β-diversity showed that the composition of the gut microbiota was different in the Con and Pec groups. Compared with the sows in the Con group, the Pec sows showed a higher abundance of the gut bacteria Clostridium and Romboutsia and a lower abundance of harmful bacteria (Micrococcaceae, Coriobacteriaceae, Dorea, Actinomyces). On the other hand, the SCFA plasma concentration was increased in the Pec group, while pro-inflammatory cytokine (IL-6, IL-1β, and TNF-α) concentrations were decreased. In conclusion, the soluble dietary fiber pectin could improve the reproductive performance and health of sows by increasing the abundance of some commensal bacteria enhancing the metabolite SCFA levels and reducing the pro-inflammatory cytokine plasma levels.

Citrus pectin protects mice from burn injury by modulating intestinal microbiota, GLP-1 secretion and immune response

Water-soluble rhamnogalacturonan-I enriched citrus pectin (WRP) has promising effect on antimicrobial defense. We aim to determine whether the modified acidic (A) or neutral (B) WRP solutions can improve intestinal microbial dysbiosis in burn-injured mice. Male Balb/c mice were gavaged with WRPs at 80, 160, 320 mg/kg. Body weight daily for 21 days before exposed to thermal injury of 15 % total body surface area and mortality was monitored. Mice with 80 mg/kg WRPs were also subjected to fecal DNAs and T cell metabonomics analysis, intestinal and plasma glucagon-like peptide 1 (GLP-1) detection, plasma defensin, immunoglobin and intestinal barrier examinations at 1 and 3d postburn (p.b.). Burn-induced mortality was only improved by low dose WRP-A (P = 0.039). Both WRPs could prevent the dysbiosis of gut microbiota in burn injury by reducing the expansion of inflammation-promoting bacteria. Both WRPs suppressed ileum GLP-1 production at 1d p.b. (P = 0.002) and plasma GLP-1 levels at 3d p.b. (P = 0.013). Plasma GLP-1 level correlated closely with ileum GLP-1 production (P = 0.019) but negatively with microbiota diversity at 1d p.b. (P = 0.003). Intestinal T cell number was increased by both WRPs in jejunum at 3d p.b. However, the exaggerated splenic T cell metabolism in burn injury was reversed by both WRPs at 1d p.b. The burn-increased plasma defensin β1 level was only reduced by WRP-B. Similarly, the intestinal barrier permeability was only rescued by WRP-B at 1d p.b. WRP-A rather than WRP-B could reduce burn-induced mortality in mice by suppressing intestinal GLP-1 secretion, restoring gut microbiota dysbiosis and improving adaptive immune response.

Modulation of pectin on intestinal barrier function via changes in microbial functional potential and bile acid metabolism

Weaning is one of the major factors that cause stress and intestinal infection in infants and in young animals due to an immature intestine and not fully developed immune functions. Pectin (PEC), a prebiotic polysaccharide, has attracted considerable attention in intestinal epithelial signaling and function via modulation of the microbial community. A total of 16 weaned piglets (21-d-old) were randomly assigned into two groups: control group and PEC group. Supplementation of 5% pectin improved intestinal mucosal barrier function by modulating the composition of the bile acid pool in piglets. Specifically, piglets in PEC group had less serum D-lactate content and alkaline phosphatase activity. In the ileum, dietary pectin increased the number of crypt PAS/AB-positive goblet cells and the mRNA expressions of MUC2, ZO-1, and Occludin. Piglets in PEC group displayed a decreased abundance of Enterococcus (2.71 vs. 65.92%), but the abundances of Lactobacillus (30.80 vs. 7.93%), Streptococcus (21.41 vs. 14.81%), and Clostridium_sensu_stricto_1 (28.34 vs. 0.01%) were increased. Elevated concentrations of bile acids especially hyocholic acid species (HCAs) including HCA, HDCA, and THDCA were also observed. Besides, correlation analysis revealed that dietary pectin supplementation may have beneficial effects through stimulation of the crosstalk between gut microbes and bile acid synthesis within the enterohepatic circulation. Thus, dietary pectin supplementation exhibited a further positive effect on the healthy growth and development of weaned piglets. These findings suggest pectin supplementation as the prebiotic is beneficial for gut health and improvement of weaned stress via regulating microbiota and bile acid metabolism.

Intragastric infusion of a liquid diet with low-methoxyl pectin alleviates fecal inconsistency and local proinflammatory cytokine expression in lipopolysaccharide-septic rats

OBJECTIVE

Diarrhea interrupts enteral nutrition management in hospitalized patients with severe illnesses, such as sepsis. Pectin, a water-soluble dietary fiber, has the potential to maintain intestinal function and may reduce inflammatory reactions. The aim of this study was to demonstrate that the addition of low-methoxyl (LM) pectin to a liquid diet suppresses softening of stool texture and reduces tissue inflammatory responses in enteral nutrition management during sepsis.

METHODS

A fat-enriched liquid diet with LM pectin (P-EN) or a liquid diet without dietary fiber (FF-EN) was given continuously to rats through a gastric catheter. Lipopolysaccharide (LPS; 10 mg/kg) was injected intraperitoneally 24 h (study 1) and 7 h (study 2) before sacrifice.

RESULTS

LPS injection significantly worsened fecal property scores in rats infused with FF-EN compared with the rats given P-EN in study 1. Whereas many myeloperoxidase-positive cells infiltrated the liver, and the hepatic expressions of chemokine genes were markedly elevated 24 h after LPS administration, these findings were clearly alleviated in the LM pectin-containing liquid diet group. In study 2, protein expressions of proinflammatory cytokines, such as small intestinal tumor necrosis factor-α and hepatic interleukin-1β, and interleukin-6, were significantly downregulated in the P-EN LPS group compared with the FF-EN LPS group.

CONCLUSIONS

A liquid diet containing LM pectin allows enteral nutrition management with a low risk for diarrhea and reduces local inflammation under septic conditions.

Effects of pectin's degree of methyl esterification on TLR2-mediated IL-8 secretion and tight junction gene expression in intestinal epithelial cells: influence of soluble TLR2

This study investigates the anti-inflammatory effects of pectins with different degrees of methyl esterification (DM) on intestinal epithelial cells (IECs) expressing low and high levels of TLR2. It also studies the influence of soluble TLR2 (sTLR2) which may be enhanced in patients with inflammatory bowel syndrome on the inflammation-attenuating effects of pectins. Also, it examines the impact of pectins on tight junction gene expression in IECs. Lemon pectins with DM18 and DM88 were characterized, and their effects on TLR2-1-induced IL8 gene expression and secretion were investigated in low-TLR2 expressing Caco-2 and high-TLR2 expressing DLD-1 cells. The results demonstrate that both DM18 and DM88 pectins can counteract TLR2-1-induced IL-8 expression and secretion, with more pronounced effects observed in DLD-1 cells expressing high levels of TLR2. Furthermore, the presence of sTLR2 does not interfere with the attenuating effects of low DM18 pectin and may even support its anti-inflammatory effects in Caco-2 cells. The impact of pectins and sTLR2 on tight junction gene expression also demonstrates cell-type-dependent effects. Overall, these findings suggest that low DM pectins possess potent anti-inflammatory properties and may influence tight junction gene expression in IECs, thereby contributing to the maintenance of gut homeostasis.

Pectin Modulates Calcium Absorption in Polarized Caco-2 Cells via a Pathway Distinct from Vitamin D Stimulation

Pectin, a type of soluble fiber, promotes morphological changes in the small intestinal villi. Although its physiological significance is unknown, we hypothesized that changes in villus morphology enhance the efficiency of nutrient absorption in the small intestine and investigated the effect of pectin derived from persimmon on calcium absorption using polarized Caco-2 cells. In polarized Caco-2 cells, pectin altered the mRNA expression levels of substances involved in calcium absorption and the regulation of intracellular calcium concentration and significantly reduced calcium absorption. Although this was comparable to the results of absorption and permeability associated with the addition of active vitamin D, the simultaneous action of pectin and active vitamin D did not show any additive effects. Furthermore, as active vitamin D significantly increases the activity of intestinal alkaline phosphatase (ALP), which is known to be involved in the regulation of intestinal absorption of calcium and lipids, we also investigated the effect of pectin on intestinal ALP activity. As a result, it was found that, unlike the effect of active vitamin D, pectin significantly reduced intestinal ALP activity. These results suggest that pectin stimulates polarized Caco-2 cells through a mechanism distinct from the regulation of calcium absorption by vitamin D, modulating total calcium absorption from the elongated villi through morphological changes in the small intestine by suppressing it at the cellular level.

Pectin a multifaceted biopolymer in the management of cancer: A review

This review article focuses on the multifaceted roles of pectin in cancer management, namely as an oncotherapeutic delivery vehicle and a pharmacological agent. Over the past decades, the potential of pectin as a novel therapeutical agent for the prevention and/or management of cancer has gained increasing interest. Pectin has been found to modulate different mechanisms involved in the onset and progression of carcinogenesis, such as galectin-3 inhibition, caspase-3-induced apoptosis, and autophagy. Elucidating the structure-activity relationship provides insight into the relationship between the structure of pectin and different mechanism/s. The bioactivity of pectin, with respect to its structure, was critically discussed to give a better insight of the relationship between the structure of the extracted pectin and the observed bioactive effects. The rhamnogalacturonan I part of the pectin chain was found to bind to galectin-3, associated with several cancer hallmarks. The anti-inflammatory and antioxidant potential of pectin were also described. The roles of pectin as a treatment enhancer and a drug delivery vehicle for oncotherapeutics were critically defined. The scientific findings presented in this paper are expected to highlight the potential and role of pectin recovered from various plant sources in preventing and managing cancer.

The potential of dietary fiber in building immunity against gastrointestinal and respiratory disorders

The numerous health benefits of dietary fibers (DFs) justify their inclusion in human diets and biomedical products. Given the short- and long-term human impacts of the COVID-19 virus on human health, the potential of DFs in building immunity against gastrointestinal and respiratory disorders is currently receiving high attention. This paper reviews the physicochemical properties of DFs, together with their immune functions and effects on the gastrointestinal tract and respiratory system mainly based on research in the last ten years. Possible modes of action of DFs in promoting health, especially building immunity, are explored. We seek to highlight the importance of understanding the exact physical and chemical characteristics and molecular behaviors of DFs in providing specific immune function. This review provides a perspective beyond the existing recognition of DFs' positive effects on human health, and offers a theoretical framework for the development of special DFs components and their application in functional foods and other therapeutic products against gastrointestinal and respiratory disorders. DFs enhance immunity from gastrointestinal and respiratory diseases to promote host health.

TLR 2/1 interaction of pectin depends on its chemical structure and conformation

Citrus pectins have demonstrated health benefits through direct interaction with Toll-like receptor 2. Methyl-ester distribution patterns over the homogalacturonan were found to contribute to such immunomodulatory activity, therefore molecular interactions with TLR2 were studied. Molecular-docking analysis was performed using four GalA-heptamers, GalA₇Me⁰, GalA₇Me^1,6, GalA₇Me^1,7 and GalA₇Me^2,5. The molecular relations were measured in various possible conformations. Furthermore, commercial citrus pectins were characterized by enzymatic fingerprinting using polygalacturonase and pectin-lyase to determine their methyl-ester distribution patterns. The response of 12 structurally different pectic polymers on TLR2 binding and the molecular docking with four pectic oligomers clearly demonstrated interactions with human-TLR2 in a structure-dependent way, where blocks of (non)methyl-esterified GalA were shown to inhibit TLR2/1 dimerization. Our results may be used to understand the immunomodulatory effects of certain pectins via TLR2. Knowledge of how pectins with certain methyl-ester distribution patterns bind to TLRs may lead to tailored pectins to prevent inflammation.

Persistence and remote sensing of agri-food wastes in the environment: Current state and perspectives

Food demand is expected to increase globally by 60-110% from 2005 to 2050 due to diet shifts and population growth. This growth in food demand leads to the generation of enormous agri-food wastes (AFWs), which could be classified into pre-consumption and post-consumption. The AFW represents economic losses for all stakeholders along food supply chains, including consumers. It is reported that the direct financial, social, and environmental costs of food waste are 1, 0.9, and 0.7 trillion USD/year, respectively. Diverse conventional AFW management approaches are employed at the different life cycle levels (entre supply chain). The review indicates that inadequate transportation, erroneous packaging, improper storage, losses during processing, contamination, issues with handling, and expiry dates are the main reason for the generation of AFWs in the supply chain. Further, various variables such as cultural, societal, personal, and behavioral factors contribute to the AFW generation. The selection of a specific valorization technology is based on multiple physicochemical and biological parameters. Furthermore, other factors like heterogeneity of the AFWs, preferable energy carriers, by-products management, cost, end-usage applications, and environmental legislative and disposal processes also play a crucial role in adopting suitable technology. Valorization of AFW could significantly impact both economy and the environment. AFWs have been widely investigated for the development of engineered added-value biomaterials and renewable energy production. Considering this, this study has been carried out to highlight the significance of AFW cost, aggregation, quantification, and membrane-based strategies for its management. The study also explored the satellite remote sensing data for Spatio-temporal monitoring, mapping, optimization, and management of AFW management. Along with this, the study also explained the most recent strategies for AFW valorization and outlined the detailed policy recommendation along with opportunities and challenges. The review suggested that AFW should be managed using a triple-bottom-line strategy (economic, social, and environmental sustainability).

The comparison of preliminary structure and intestinal anti-inflammatory and anti-oxidative activities of polysaccharides from different root parts of Angelica sinensis (Oliv.) Diels

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Angelica sinensis, has been commonly used in gynecology for centuries, and is normally applied divided into different parts in various clinical applications. At present, the majority of existing studies focus on the volatile oil and ferulic acid extracted from different parts of A. sinensis, but there is a dearth of scientific information on its water-soluble polysaccharides.

AIM OF THE STUDY

The structures of polysaccharides from plants, have been reported contributing to multiple pharmacological activities such as anti-oxidative, anti-inflammatory, anti-tumor and liver protection. Therefore, the focus of this study was on its anti-oxidative and anti-inflammatory activities in vitro, which would be based on the various polysaccharides with distinct structures obtained from different parts of the A. sinensis root.

MATERIALS AND METHODS

Four parts of A. sinensis root were separated according to the Chinese Pharmacopoeia: head, body, tail and whole body. Crude polysaccharides were obtained by water extraction and ethanol precipitation method, and were further fractionated by DEAE Sepharose chromatographic column and gel filtration. The comparison of ASPs from different root parts were performed, including chemical compositions determined by colorimetric analysis, monosaccharide compositions measured by high performance liquid chromatography (HPLC), glycosidic linkage units determined by methylation and gas chromatography-mass spectrometry (GC-MS), organic functional groups determined by FT-IR, molecular weight (Mw) demarcated by gel permeation chromatography, and the viscosities and solubilities were measured according to method published in the previous report with minor modification. In vitro biological activities of APSs were compared on lipopolysaccharide (LPS)-induced inflammatory and oxidative stress models on IPEC-J2 cells.

RESULTS

Four purified polysaccharides, ASP-H-AP, ASP-B-AP, ASP-T-AP and ASP-Hb-AP from the root of A. sinensis, were obtained, and consisted of various contents of protein and the polyphenol. They were possibly pectic polysaccharides with a long homogalacturonan region as the main backbone and ramified with rhamnogalacturonan I region, but they were differed by subregions and the relative contents of glycosidic units. The Mw of four pectic polysaccharides were ranged from 67.9-267.7 kDa. The infrared spectrum also showed that the four polysaccharide fractions contained the characteristic peaks of polysaccharides. Their distinct primary structure could lead to a variety of biological activities. In vitro biological assays suggested that four polysaccharide fractions can protect IPEC-J2 cells against the LPS-induced inflammation by down-regulating inflammation factors and related genes on IPEC-J2 cells. These polysaccharides also could alleviate oxidative stress on IPEC-J2 cells by up-regulating the gene and protein expressions of antioxidant enzymes. It was concluded that ASP-H-AP possessed better anti-inflammatory and anti-oxidative effects, while those of ASP-T-AP was relatively poor among the four polysaccharide fractions.

CONCLUSION

All results indicated that the structure of pectic polysaccharides from different root parts of A. sinensis differed, which lead to their distinct anti-inflammatory and anti-oxidative activities. This may also be one of the factors why different parts of A. sinensis showed various pharmacological activities and applied independently in traditional use. In addition, it would be valuable for further studies on structure-activity relationship of polysaccharides obtained by different root parts of A. sinensis.

Pectin supplementation ameliorates intestinal epithelial barrier function damage by modulating intestinal microbiota in lipopolysaccharide-challenged piglets

During weaning, infants and young animals are susceptible to severe enteric infections, thus inducing intestinal microbiota dysbiosis, intestinal inflammation, and impaired intestinal barrier function. Pectin (PEC), a prebiotic polysaccharide, enhances intestinal health with the potential for therapeutic effect on intestinal diseases. One 21-days study was conducted to investigate the protective effect of pectin against intestinal injury induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) in a piglet model. A total of 24 piglets (6.77±0.92 kg BW; Duroc × Landrace × Large White; barrows; 21 d of age) were randomly assigned into three groups: control group, LPS-challenged group, and PEC + LPS group. Piglets were administrated with LPS or saline on d14 and d21 of the experiment. All piglets were slaughtered and intestinal samples were collected after 3 h administration on d21. Pectin supplementation ameliorated the LPS-induced inflammation response and damage to the ileal morphology. Meanwhile, pectin also improved intestinal mucin barrier function, increased the mRNA expression of MUC2, and improved intestinal mucus glycosylation. LPS challenge reduced the diversity of intestinal microbiota and enriched the relative abundance of Helicobacter. Pectin restored alpha diversity improved the structure of the gut microbiota by enriching anti-inflammatory bacteria and short-chain fatty acid (SCFA)-producing bacteria, and increased the concentrations of acetate. In addition, Spearman rank correlation analysis also revealed the potential relationship between intestinal microbiota and intestinal morphology, intestinal inflammation, and intestinal glycosylation in piglets. Taken together, these results indicate that pectin enhances intestinal integrity and barrier function by altering intestinal microbiota composition and their metabolites, which subsequently alleviates intestinal injury and finally improves the growth performance of piglets.

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.

Immune-instructive copolymer scaffolds using plant-derived nanoparticles to promote bone regeneration

Background

Age-driven immune signals cause a state of chronic low-grade inflammation and in consequence affect bone healing and cause challenges for clinicians when repairing critical-sized bone defects in elderly patients.

Methods

Poly(l-lactide-co-ɛ-caprolactone) (PLCA) scaffolds are functionalized with plant-derived nanoparticles from potato, rhamnogalacturonan-I (RG-I), to investigate their ability to modulate inflammation in vitro in neutrophils and macrophages at gene and protein levels. The scaffolds’ early and late host response at gene, protein and histological levels is tested in vivo in a subcutaneous rat model and their potential to promote bone regeneration in an aged rodent was tested in a critical-sized calvaria bone defect. Significant differences were tested using one-way ANOVA, followed by a multiple-comparison Tukey’s test with a p value ≤ 0.05 considered significant.

Results

Gene expressions revealed PLCA scaffold functionalized with plant-derived RG-I with a relatively higher amount of galactose than arabinose (potato dearabinated (PA)) to reduce the inflammatory state stimulated by bacterial LPS in neutrophils and macrophages in vitro. LPS-stimulated neutrophils show a significantly decreased intracellular accumulation of galectin-3 in the presence of PA functionalization compared to Control (unmodified PLCA scaffolds). The in vivo gene and protein expressions revealed comparable results to in vitro. The host response is modulated towards anti-inflammatory/ healing at early and late time points at gene and protein levels. A reduced foreign body reaction and fibrous capsule formation is observed when PLCA scaffolds functionalized with PA were implanted in vivo subcutaneously. PLCA scaffolds functionalized with PA modulated the cytokine and chemokine expressions in vivo during early and late inflammatory phases. PLCA scaffolds functionalized with PA implanted in calvaria defects of aged rats downregulating pro-inflammatory gene markers while promoting osteogenic markers after 2 weeks in vivo.

Conclusion

We have shown that PLCA scaffolds functionalized with plant-derived RG-I with a relatively higher amount of galactose play a role in the modulation of inflammatory responses both in vitro and in vivo subcutaneously and promote the initiation of bone formation in a critical-sized bone defect of an aged rodent. Our study addresses the increasing demand in bone tissue engineering for immunomodulatory 3D scaffolds that promote osteogenesis and modulate immune responses.

The Complex Biological Effects of Pectin: Galectin-3 Targeting as Potential Human Health Improvement?

Galectin-3 is the only chimeric representative of the galectin family. Although galectin-3 has ubiquitous regulatory and physiological effects, there is a great number of pathological environments where galectin-3 cooperatively participates. Pectin is composed of different chemical structures, such as homogalacturonans, rhamnogalacturonans, and side chains. The study of pectin's major structural aspects is fundamental to predicting the impact of pectin on human health, especially regarding distinct molecular modulation. One of the explored pectin's biological activities is the possible galectin-3 protein regulation. The present review focuses on revealing the structure/function relationship of pectins, their fragments, and their biological effects. The discussion highlighted by this review shows different effects described within in vitro and in vivo experimental models, with interesting and sometimes contradictory results, especially regarding galectin-3 interaction. The review demonstrates that pectins are promissory food-derived molecules for different bioactive functions. However, galectin-3 inhibition by pectin had been stated in literature before, although it is not a fully understood, experimentally convincing, and commonly agreed issue. It is demonstrated that more studies focusing on structural analysis and its relation to the observed beneficial effects, as well as substantial propositions of cause and effect alongside robust data, are needed for different pectin molecules' interactions with galectin-3.

Polysaccharides confer benefits in immune regulation and multiple sclerosis by interacting with gut microbiota

Pharmacological and clinical studies have consistently demonstrated that polysaccharides exhibit great potential on immune regulation. Polysaccharides can interact directly or indirectly with the immune system, triggering cell-cell communication and molecular recognition, leading to immunostimulatory responses. Gut microbiota is adept at foraging polysaccharides as energy sources and confers benefits in the context of immunity and chronic autoimmune disease, such as multiple sclerosis. A compelling set of interconnectedness between the gut microbiota, natural polysaccharides, and immune regulation has emerged. In this review, we highlighted the available avenues supporting the existence of these interactions, with a focus on cytokines-mediated and SCFAs-mediated pathways. Additionally, the neuroimmune mechanisms for gut microbiota communication with the brain in multiple sclerosis are also discussed, which will lay the ground for ameliorate multiple sclerosis via polysaccharide intervention.

Pectins that Structurally Differ in the Distribution of Methyl-Esters Attenuate Citrobacter rodentium-Induced Colitis

INTRODUCTION

Pectins have anti-inflammatory properties on intestinal immunity through direct interactions on Toll-like receptors (TLRs) in the small intestine or via stimulating microbiota-dependent effects in the large intestine. Both the degree of methyl-esterification (DM) and the distribution of methyl-esters (degree of blockiness; DB) of pectins contribute to this influence on immunity, but whether and how the DB impacts immunity through microbiota-dependent effects in the large intestine is unknown. Therefore, this study tests pectins that structurally differ in DB in a mouse model with Citrobacter rodentium induced colitis and studies the impact on the intestinal microbiota composition and associated attenuation of inflammation.

METHODS AND RESULTS

Both low and high DB pectins induce a more rich and diverse microbiota composition. These pectins also lower the bacterial load of C. rodentium in cecal digesta. Through these effects, both low and high DB pectins attenuate C. rodentium induced colitis resulting in reduced intestinal damage, reduced numbers of Th1-cells, which are increased in case of C. rodentium induced colitis, and reduced levels of GATA3+ Tregs, which are related to tissue inflammation.

CONCLUSION

Pectins prevent C. rodentium induced colonic inflammation by lowering the C. rodentium load in the caecum independently of the DB.

Characterization of Citrus Pectin Oligosaccharides and Their Microbial Metabolites as Modulators of Immunometabolism on Macrophages

We characterized the structure of prepared citrus pectin oligosaccharides (POS) and investigated the immunometabolism-modulating effects of POS and their microbial metabolites on human macrophages. Both POS and metabolites activated immune responses and exhibited anti-inflammatory properties in the presence of lipopolysaccharide (LPS) via regulating expressions of inflammatory cytokines and nuclear factor-kappa B. Cholesterol efflux was also facilitated via increased gene expressions of the liver X receptor-α-adenosine triphosphate-binding cassette transporter (ABC) A1/ABCG1 pathway and suppressed cholesterol synthesis via suppressing expressions of 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Microbial degradation prevented POS from attenuating palmitoyl-3-cysteine-serine-lysine-4-induced inflammation and promoting M2 polarization, but it is capable of inhibiting cholesterol uptake-related genes CD36 and SR-A. These findings indicate that immunometabolism-modulating effects of POS are not solely microbiota-dependent effects. Both POS and their microbial metabolites are potential immunometabolism modulators via different mechanisms.

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.

Impact of Bacterial Metabolites on Gut Barrier Function and Host Immunity: A Focus on Bacterial Metabolism and Its Relevance for Intestinal Inflammation

The diverse and dynamic microbial community of the human gastrointestinal tract plays a vital role in health, with gut microbiota supporting the development and function of the gut immune barrier. Crosstalk between microbiota-gut epithelium and the gut immune system determine the individual health status, and any crosstalk disturbance may lead to chronic intestinal conditions, such as inflammatory bowel diseases (IBD) and celiac disease. Microbiota-derived metabolites are crucial mediators of host-microbial interactions. Some beneficially affect host physiology such as short-chain fatty acids (SCFAs) and secondary bile acids. Also, tryptophan catabolites determine immune responses, such as through binding to the aryl hydrocarbon receptor (AhR). AhR is abundantly present at mucosal surfaces and when activated enhances intestinal epithelial barrier function as well as regulatory immune responses. Exogenous diet-derived indoles (tryptophan) are a major source of endogenous AhR ligand precursors and together with SCFAs and secondary bile acids regulate inflammation by lowering stress in epithelium and gut immunity, and in IBD, AhR expression is downregulated together with tryptophan metabolites. Here, we present an overview of host microbiota-epithelium- gut immunity crosstalk and review how microbial-derived metabolites contribute to host immune homeostasis. Also, we discuss the therapeutic potential of bacterial catabolites for IBD and celiac disease and how essential dietary components such as dietary fibers and bacterial tryptophan catabolites may contribute to intestinal and systemic homeostasis.

Anti-inflammatory activity of citrus pectin on chicken monocytes' immune response

Pectin is a dietary fibre composed of galacturonic acid, primarily found in the citrus fruits' cell walls. Citrus pectin (CP) has demonstrated antioxidative, anticancer, and anti-inflammatory properties in humans and animals. In broilers, CP supplementation improves energy utilization and nutrient digestibility, but limited information on its effects on chicken immunity is available so far. This study aimed to assess the in vitro impact of CP on chicken monocytes' immune response. Cells were purified from whole blood of healthy chickens and incubated with increasing concentrations (0, 0.25, 0.5, 0.75, 1 mg/mL) of CP to determine CP working concentration. The effects of different CP concentrations on cells' apoptosis and viability were assessed by measuring caspase-3 and -7 and the cells' metabolic activity (MTT assay), respectively. CP had no dose-dependent effect on monocyte apoptosis and viability.Then, the effects of CP (0.5 mg/mL) on chicken monocytes' chemotaxis and phagocytosis were assessed by measuring transwell migration and fluorescein-labelled E. coli incorporation, respectively. CP inhibited both monocytes' chemotaxis and phagocytosis.These data demonstrate that CP exerts an immunomodulatory role in chicken monocytes, supporting its integration in nutrition strategies that might be beneficial for the animal's immunity and health.

Valorization of fruits and vegetable wastes and by-products to produce natural pigments

Synthetic pigments from petrochemicals have been extensively used in a wide range of food products. However, these pigments have adverse effects on human health that has rendered it obligatory to the scientific community in order to explore for much safer, natural, and eco-friendly pigments. In this regard, exploiting the potential of agri-food wastes presumes importance, extracted mainly by employing green processing and extraction technologies. Of late, pigments market size is growing rapidly owing to their extensive uses. Hence, there is a need for sustainable production of pigments from renewable bioresources. Valorization of vegetal wastes (fruits and vegetables) and their by-products (e.g. peels, seeds or pomace) can meet the demands of natural pigment production at the industrial levels for potential food, pharmaceuticals, and cosmeceuticals applications. These wastes/by-products are a rich source of natural pigments such as: anthocyanins, betalains, carotenoids, and chlorophylls. It is envisaged that these natural pigments can contribute significantly to the development of functional foods as well as impart rich biotherapeutic potential. With a sustainability approach, we have critically reviewed vital research information and developments made on natural pigments from vegetal wastes, greener extraction and processing technologies, encapsulation techniques and potential bioactivities. Designed with an eco-friendly approach, it is expected that this review will benefit not only the concerned industries but also be of use to health-conscious consumers.

Effects of dietary fibre intake in chemotherapy-induced mucositis in murine model

Mucositis is an inflammation of the gastrointestinal mucosa resulting from high doses of radio/chemotherapy treatment and may lead to interruption of antineoplasic therapy. Soluble fibres, like pectin, increase SCFA production, which play a role in gut homoeostasis and inflammation suppression. Due to the properties of pectin, the aim of the present study was to evaluate the effect of a high-fibre (HF) diet on chemotherapy-induced mucositis in a murine model. C57/BL6 mice received control (AIN93M), HF, low/zero fibre (LF) diets for 10 d prior to mucositis challenging with irinotecan (75 mg/kg), or they were treated with acetate added to drinking water 5 d prior to and during the mucositis induction. Mice that received the HF diet showed decreased immune cells influx and improved histopathological parameters in the intestine, compared with mice that received the normal diet. Furthermore, the HF diet decreased intestinal permeability induced in the mucositis model when compared with the control group. This effect was not observed for acetate alone, which did not improve gut permeability. For instance, mice that received the LF diet had worsened gut permeability, compared with mice that received the normal diet and mucositis. The effects of the HF and LF diets were shown to modulate the intestinal microbiota, in which the LF diet increased the levels of Enterobacteriaceae, a group associated with gut inflammation, whereas the HF diet decreased this group and increased Lactobacillus and Bifidobacterium (SCFA producers) levels. In conclusion, the results demonstrated the importance of dietary fibre intake in the modulation of gut microbiota composition and homoeostasis maintenance during mucositis in this model.

How Pectin Play a Role in Histological Changes by Monosodium Glutamate (MSG) in the Ovary of Mice?

BACKGROUND AND OBJECTIVE

The effects of pectin from the natural vitamins and herbs on the ovary of mice induced by monosodium glutamate (MSG) leads to over accumulations in living cells and finally produces cellular toxicity and damage, pectin helps to rapidly reduce this changes.

MATERIALS AND METHODS

Cytotoxicity of monosodium glutamate was investigated histologically by using hematoxylin and eosin (H and E) stains. The animals received (MSG) in drinking water at a dose of 3 g kg-1 b.wt., in drinking water for three weeks. The ovary tissues were subjected to histological and morphological analysis.

RESULTS

In female rats treated with a dose of MSG of 3 g kg-1 daily in drinking water clear toxicological effects on the ovary tissue were significantly obtained. The mice were then anesthetized, dissected the ovary samples were taken from female mice and kept in a 10% neutral formalin solution to make tissue slides after that examined under the microscope to see the differences. Sections showed the occurrence of several histopathological changes in the ovary.

CONCLUSION

This study concluded that the effectiveness of pectin therapy on ovarian cells destroyed by the effect of monosodium glutamate, which has proven to be very effective in treating all affected and restoring tissue to normal.

The impact of the level and distribution of methyl-esters of pectins on TLR2-1 dependent anti-inflammatory responses

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

The effects of different dietary fiber pectin structures on the gastrointestinal immune barrier: impact via gut microbiota and direct effects on immune cells

Pectins are dietary fibers with different structural characteristics. Specific pectin structures can influence the gastrointestinal immune barrier by directly interacting with immune cells or by impacting the intestinal microbiota. The impact of pectin strongly depends on the specific structural characteristics of pectin; for example, the degree of methyl-esterification, acetylation and rhamnogalacturonan I or rhamnogalacturonan II neutral side chains. Here, we review the interactions of specific pectin structures with the gastrointestinal immune barrier. The effects of pectin include strengthening the mucus layer, enhancing epithelial integrity, and activating or inhibiting dendritic cell and macrophage responses. The direct interaction of pectins with the gastrointestinal immune barrier may be governed through pattern recognition receptors, such as Toll-like receptors 2 and 4 or Galectin-3. In addition, specific pectins can stimulate the diversity and abundance of beneficial microbial communities. Furthermore, the gastrointestinal immune barrier may be enhanced by short-chain fatty acids. Moreover, pectins can enhance the intestinal immune barrier by favoring the adhesion of commensal bacteria and inhibiting the adhesion of pathogens to epithelial cells. Current data illustrate that pectin may be a powerful dietary fiber to manage and prevent several inflammatory conditions, but additional human studies with pectin molecules with well-defined structures are urgently needed.

Intestinal anti-inflammatory effects of artichoke pectin and modified pectin fractions in the dextran sulfate sodium model of mice colitis. Artificial neural network modelling of inflammatory markers

Anti-inflammatory properties of artichoke pectin and modified fractions (arabinose- and galactose-free) used at two doses (40 and 80 mg kg-1) in mice with colitis induced by dextran sulfate sodium have been investigated. Expression of pro-inflammatory markers TNF-α and ICAM-I decreased in groups of mice treated with original and arabinose-free artichoke pectin while IL-1β and IL-6 liberation was reduced only in mice groups treated with original artichoke pectin. A decrease in iNOS and TLR-4 expression was observed for most treatments. Intestinal barrier gene expression was also determined. MUC-1 and Occludin increased in groups treated with original artichoke pectin while MUC-3 expression also increased in arabinose-free pectin treatment. Galactose elimination led to a loss of pectin bioactivity. Characteristic expression profiles were established for each treatment through artificial neural networks showing high accuracy rates (≥90%). These results highlight the potential amelioration of inflammatory bowel disease on mice model colitis through artichoke pectin administration.

Pectin Interaction with Immune Receptors is Modulated by Ripening Process in Papayas

Dietary fibers have been shown to exert immune effects via interaction with pattern recognition receptors (PRR) such as toll-like receptors (TLR) and nucleotide-binding oligomerization domain (NOD)-like receptors. Pectin is a dietary fiber that interacts with PRR depending on its chemical structure. Papaya pectin retains different chemical structures at different ripening stages. How this influence PRR signaling is unknown. The aim of this work was to determine how ripening influences pectin structures and their ability to interact with TLR2, 3, 4, 5 and 9, and NOD1 and 2. It was evaluated the interaction of the water-soluble fractions rich in pectin extracted from unripe to ripe papayas. The pectin extracted from ripe papayas activated all the TLR and, to a lesser extent, the NOD receptors. The pectin extracted from unripe papayas also activated TLR2, 4 and 5 but inhibited the activation of TLR3 and 9. The differences in pectin structures are the higher methyl esterification and smaller galacturonan chains of pectin from ripe papayas. Our finding might lead to selection of ripening stages for tailored modulation of PRR to support or attenuate immunity.

Bioactives From Agri-Food Wastes: Present Insights and Future Challenges

Sustainable utilization of agri-food wastes and by-products for producing value-added products (for cosmetic, pharmaceutical or food industrial applications) provides an opportunity for earning additional income for the dependent industrial sector. Besides, effective valorisation of wastes/by-products can efficiently help in reducing environmental stress by decreasing unwarranted pollution. The major focus of this review is to provide comprehensive information on valorisation of agri-food wastes and by-products with focus laid on bioactive compounds and bioactivity. The review covers the bioactives identified from wastes and by-products of plants (fruits, exotic fruits, vegetables and seeds), animals (dairy and meat) and marine (fish, shellfish seaweeds) resources. Further, insights on the present status and future challenges of sustainably utilizing agri-food wastes/by-products for value addition will be highlighted.

Dietary Fiber Pectin Ameliorates Experimental Colitis in a Neutral Sugar Side Chain-Dependent Manner

Dietary fiber, with intake of soluble fibers in particular, has been reported to lower the risk for developing inflammatory bowel diseases (IBD). This is at least partly attributable to the fermentation of dietary fiber by the colonic microbiota to produce short chain fatty acids. Pectin, a widely consumed soluble fiber, is known to exert a protective effect in murine models of IBD, but the underlying mechanism remains elusive. Apart from having a prebiotic effect, it has been suggested that pectin direct influences host cells by modulating the inflammatory response in a manner dependent on its neutral sugar side chains. Here we examined the effect of the side chain content of pectin on the pathogenesis of experimental colitis in mice. Male C57BL/6 mice were fed a pectin-free diet, or a diet supplemented with characteristically high (5% orange pectin) or low (5% citrus pectin) side chain content for 10-14 days, and then administered 2,4,6-trinitrobenzene sulfonic acid or dextran sulfate sodium to induce colitis. We found that the clinical symptoms and tissue damage in the colon were ameliorated in mice that were pre-fed with orange pectin, but not in those pre-fed with citrus pectin. Although the population of CD4⁺Foxp⁺ regulatory T cells and CD4⁺RORγt⁺ inflammatory T cells in the colon were comparable between citrus and orange pectin-fed mice, colonic interleukin (IL)-1β and IL-6 levels in orange pectin-fed mice were significantly decreased. The fecal concentration of propionic acid in orange pectin-fed mice was slightly but significantly higher than that in control and citrus pectin-fed mice but the cecal concentration of propionic acid after the induction of TNBS colitis was comparable between orange and citrus pectin-fed mice. Furthermore, the protective effect of orange pectin against colitis was observed even in mice treated with antibiotics. IL-6 production from RAW264.7 cells stimulated with the toll-like receptor agonist Pam3CSK4 or lipopolysaccharide was suppressed by pre-treatment with orange pectin in vitro. Taken together, these results suggest that the side chains of pectin not only augment prebiotic effects but also directly regulate IL-6 production from intestinal host cells in a microbiota-independent fashion to attenuate colitis.

Anti-inflammatory effect of aqueous extract from Kawachi-bankan (Citrus maxima) peel in vitro and in vivo

Kawachi-bankan (Citrus maxima) is one of the citruses produced in Ehime, Japan. Although health functions of flavonoids and carotenoids in citrus peel have been studied very well, those of water-soluble substances in the peel have not been focused. We herein indicated the anti-inflammatory effect of Kawachi-bankan peel aqueous extract (KPE) in vitro and in vivo. KPE significantly inhibited the production of inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α by LPS-stimulated RAW264.7 cells without cytotoxicity. KPE also significantly inhibited the mRNA expression levels of IL-6 and TNF-α in the cells, suggesting that KPE inhibits the production of inflammatory cytokines by suppressing the gene expression levels. Immunoblot analysis revealed that KPE shows an anti-inflammatory effect on macrophages through the suppression of the phosphorylation of p38 and the translocation of NF-κB into nucleus. The oral administration of KPE inhibited the serum levels of inflammatory cytokines and improved the survival rate in systemic inflammatory response syndrome (SIRS) model mice. Our experiments using a cell line suggested that KPE inhibits the production of inflammatory cytokines by macrophages in hyperinflammatory state. In addition, experiments in vivo showed that the oral administration of KPE inhibited the serum levels of inflammatory cytokines and improved the survival rate in SIRS model mice. Our findings indicated that KPE contributes to alleviating of a hyperinflammatory response.

Ingestion of Non-digestible Carbohydrates From Plant-Source Foods and Decreased Risk of Colorectal Cancer: A Review on the Biological Effects and the Mechanisms of Action

The hypothesis that links the increase in the intake of plant-source foods to a decrease in colorectal cancer (CRC) risk has almost 50 years. Nowadays, systematic reviews and meta-analysis of case-control and cohort studies confirmed the association between dietary patterns and CRC risk, in which the non-digestible carbohydrates (NDC) from plant-source foods are known to play beneficial effects. However, the mechanisms behind the physicochemical properties and biological effects induced by NDC on the decrease of CRC development and progression remain not fully understood. NDC from plant-source foods consist mainly of complex carbohydrates from plant cell wall including pectin and hemicellulose, which vary among foods in structure and in composition, therefore in both physicochemical properties and biological effects. In the present review, we highlighted the mechanisms and described the recent findings showing how these complex NDC from plant-source foods are related to a decrease in CRC risk through induction of both physicochemical effects in the gastrointestinal tract, fermentation-related effects, and direct effects resulting from the interaction between NDC and cellular components including toll-like receptors and galectin-3. Studies support that the definition of the structure-function relationship-especially regarding the fermentation-related effects of NDC, as well as the direct effects of these complex carbohydrates in cells-is crucial for understanding the possible NDC anticancer effects. The dietary recommendations for the intake of NDC are usually quantitative, describing a defined amount of intake per day. However, as NDC from plant-source foods can exert effects that vary widely according to the NDC structure, the dietary recommendations for the intake of NDC plant-source foods are expected to change from a quantitative to a qualitative perspective in the next few years, as occurred for lipid recommendations. Thus, further studies are necessary to define whether specific and well-characterized NDC from plant-source foods induce beneficial effects related to a decrease in CRC risk, thereby improving nutritional recommendations of healthy individuals and CRC patients.

The potential of pectin to impact pig nutrition and health: feeding the animal and its microbiome

The increasing efforts to substitute antibiotics and improve animal health combined with the acknowledgement of the role of gut microbiota in health have led to an elevated interest in the understanding on how fibre with prebiotic potential, such as pectin, can improve animal growth and health via direct or gut microbiota mediated effects. Various reports exist on the antiviral and antibacterial effects of pectin, as well as its potency as a modulator of the immune response and gut microbial community. Comprehensive insights into the potential of pectin to improve animal growth and health are currently still hampered by heterogeneity in the design of studies. Studies differ with regard to the dosage, molecular structure and source of the pectin implemented, as well as concerning the set of investigations of its effects on the host. Harmonisation of the study design including an in-depth analysis of the gut microbial community and its metabolome will aid to extract information on how pectin can impact growth and overall animal health. Studies with an increased focus on pectin structure such as on pectin-derived rhamnogalacturonan I (RG-I) are just starting to unravel pectin-structure-related effects on mammalian health.

Oxidative DNA damage induced by ROS-modulating agents with the ability to target DNA: A comparison of the biological characteristics of citrus pectin and apple pectin

DNA targeting anticancer agents have been very successful in clinic, especially, when used in combinatorial therapy. But unfortunately, they often exhibit high levels of toxicity towards normal cells. Hence, much effort has been put into finding agents with more selectivity, and less toxicity. Pectins are natural polysaccharides, and beneficial nutritional fibers that have attracted attentions due to their antitumor properties. However, their molecular targets, and mechanism of action are widely unknown. Here, we have reported that citrus pectin (CP) and apple pectin (AP) selectively suppress viability in MDA-MB-231, MCF-7 and T47D human Breast cancer cells, while non-toxic to L929 normal cells. Upon CP, and AP treatments, cancer cells’ ROS content increased rapidly, and led to the collapse of the mitochondrial transmembrane potential which functions upstream of the caspase-dependent apoptosis. CP and AP treated cancer cells were also arrested at the S and G1 or G2/M phases of the cell cycle, respectively. Furthermore, mRNA expression of Galectin-3 (a multi-functional lectin involved in cell adhesion, cell cycle, and apoptosis) reduced in both CP and AP treated cells. Growth inhibition of MDA-MB-231 cells by CP, and AP was concomitant with DNA damage (oxidation, and strand breaks). In this context, in an effort to clarify the mechanism of action, we showed that CP, and AP are able to interact with DNA. The strength and mode of DNA binding were established by spectroscopy techniques. We demonstrated that CP, and AP bind to dsDNA by intercalation, and groove binding/partial intercalation, respectively. In conclusion, our findings suggest that CP, and AP induce apoptosis in MDA-MB-231 cells by increasing the release of ROS, which may be related to the mitochondrial apoptosis pathway, and direct interactions with DNA. Our data indicate that these compounds may be potentially useful in cancer treatment.

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

Colon cancer (CC) is the third common neoplasm worldwide, and it is still a big challenge for exploring new effective medicine for treating CC. Natural product promoting human health has become a hot topic and attracted many researchers recently. Pectin, a complex polysaccharide in plant cell wall, mainly consists of four major types of polysaccharides: homogalacturonan, xylogalacturonan, rhamnogalacturonan I and II, all of which can be degraded into various pectin oligosaccharides (POS) and may provide abundant resource for exploring potential anticancer drugs. POS have been regarded as a novel class of potential functional food with multiple health-promoting properties. POS have antibacterial activities against some aggressive and recurrent bacterial infection and exert beneficial immunomodulation for controlling CC risk. However, the molecular functional role of POS in the prevention of CC risk and progression remains doubtful. The review focuses on antioxidant and anti-inflammatory roles of POS for promoting human health by regulating some potential oxidative and inflammation-activated pathways, such as ATP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor-2 (Nrf2), and nuclear factor-κB (NF-κB) pathways. The activation of these signaling pathways increases the antioxidant and antiinflammatory activities, which will result in the apoptosis of CC cells or in the prevention of CC risk and progression. Thus, POS may inhibit CC development by affecting antioxidant and antiinflammatory signaling pathways AMPK, Nrf2, and NF-κB. However, POS also can activate signal transduction and transcriptional activator 1 and 3 signaling pathway, which will reduce antioxidant and anti-inflammatory properties and promote CC progression. Specific structural and structurally modified POS may be associated with their functions and should be deeply explored in the future. The present review paper lacks the important information for the linkage between the specific structure of POS and its function. To further explore the effects of prebiotic potential of POS and their derivatives on human immunomodulation in the prevention of CC, the specific POS with a certain degree of polymerization or purified polymers are highly demanded to be performed in clinical practice.

Dietary Fiber Pectin Directly Blocks Toll-Like Receptor 2-1 and Prevents Doxorubicin-Induced Ileitis

Dietary carbohydrate fibers are known to prevent immunological diseases common in Western countries such as allergy and asthma but the underlying mechanisms are largely unknown. Until now beneficial effects of dietary fibers are mainly attributed to fermentation products of the fibers such as anti-inflammatory short-chain fatty acids (SCFAs). Here, we found and present a new mechanism by which dietary fibers can be anti-inflammatory: a commonly consumed fiber, pectin, blocks innate immune receptors. We show that pectin binds and inhibits, toll-like receptor 2 (TLR2) and specifically inhibits the proinflammatory TLR2-TLR1 pathway while the tolerogenic TLR2-TLR6 pathway remains unaltered. This effect is most pronounced with pectins having a low degree of methyl esterification (DM). Low-DM pectin interacts with TLR2 through electrostatic forces between non-esterified galacturonic acids on the pectin and positive charges on the TLR2 ectodomain, as confirmed by testing pectin binding on mutated TLR2. The anti-inflammatory effect of low-DM pectins was first studied in human dendritic cells and mouse macrophages in vitro and was subsequently tested in vivo in TLR2-dependent ileitis in a mouse model. In these mice, ileitis was prevented by pectin administration. Protective effects were shown to be TLR2-TLR1 dependent and independent of the SCFAs produced by the gut microbiota. These data suggest that low-DM pectins as a source of dietary fiber can reduce inflammation through direct interaction with TLR2-TLR1 receptors.