Characterization of a neutral polysaccharide from pumpkin (Cucurbita moschata Duch) with potential immunomodulatory activity

De-starched Panax ginseng polysaccharide: Preparation, in vitro digestion, fermentation properties and the activating effect of the resultant products on RAW264.7 cells

Panax ginseng C. A. Meyer (ginseng) neutral polysaccharides have been proven to be an immune enhancer, but their digestion and fermentation characteristics are unclear. This study aimed to prepare a de-starched polysaccharide (DGPN) from ginseng and investigate its degradation rules and the changes in immune activity by using an in vitro digestion and fermentation model. Results showed that in digestion process, the molecular weight of DGPN decreased from 4.72 × 104 to 4.04 × 104 Da, reducing sugar (CR) content increased from 0.0539 ± 0.0037 to 0.0919 ± 0.0015 mg/mL. During the fecal fermentation process, a significant decrease in total carbohydrate content and molecular weight, a significant increase in CR and change in the proportion of monosaccharide composition can be observed, indicating that DGPN was mainly degraded during fermentation process. DGPN modulated the microbial composition via increasing the relative abundance of beneficial bacteria including Bacteroides, [Eubacterium]_nodatum_group, Ligilactobacillus, Enterococcus and reducing harmful bacteria such as Escherichia_Shigela. DGPN also promoted the production of short chain fatty acids. Cell experiments results showed that fermentation product DGPN-F48 activated RAW264.7 cells via TLR4/Myd88/NF-κB signaling pathway and the activity was significantly enhanced after fermentation process. This study confirmed DGPN is beneficial for enhancing gut health and has prebiotic potential.

Immunomodulatory Acidic Polysaccharide from Jujube Fruit (Zizyphus jujuba Mill.): Insight into Their Chemical Characteristics and Modes of Action

Jujube (Zizyphus jujuba Mill.) has been consumed globally as a fruit and a nutraceutical food for millennia. This study presents the isolation and purification of a novel water-soluble polysaccharide fraction, ZJMP-2, from Z. jujuba Mill. ZJMP-2 underwent characterization through Fourier transform infrared (FT-IR), high-performance gel permeation chromatography-laser light scattering (HPGPC-LLS), gas chromatography-mass spectrometry (GC-MS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and nuclear magnetic resonance (NMR) analyses. It consists of glucose, galactose, arabinose, rhamnose, and galacturonic acid in molar ratios of 0.41:0.08:0.11:0.05:0.33 and boasts an average molecular weight of approximately 57.8 kDa. Its backbone features the structure →2)-α-l-Rhap-(1 → 4)-α-d-GalpA-(1 → 4)-α-d-GalpA-6OMe-(1 → 4)-α-d-GalpA-(1 → 3, 4)-α-d-Glcp-(1 →, with branching at →5)-α-l-Araf-(1 →, →4)-β-d-Galp-(1 →, and →4)-α-d-Glcp-(1→ at position O-3 of →3, 4)-α-d-Glcp-(1 →. These structural variations contribute to the pronounced immunoregulatory effects of ZJMP-2. Specifically, ZJMP-2 significantly elevated the expression levels of TLR4, NF-κB, and TRAF6 proteins, enhancing RAW264.7 cell activity, index of splenic lymphocytes, and the production of cytokines and NO, thereby activating macrophages and promoting lymphocyte proliferation. In vivo studies demonstrated that ZJMP-2 promoted the heart, spleen, and bone marrow indices, peripheral blood and spleen cell counts, and the number of heart and bone marrow cells in mice. These findings demonstrated that ZJMP-2 has potential as an immunomodulator and provides valuable insights for developing natural immunomodulators in the pharmaceutical industry.

A glucan from the stems of Acanthopanax senticosus: Structure and anticolorectal cancer activity

ASPN-1, a novel glucan with a molecular weight of 33.31 kDa, was purified from Acanthopanax senticosus stems, characterized in structure, and evaluated for antitumor potential. The analysis of the structure of ASPN-1 revealed that it consisted of a backbone constructed from →4)-α-D-Glcp-(1 → glucosyls, branched at the O-3 position by an α-D-Glcp-(1 → residue and at the O-6 positions with α-D-Glcp-(1 → 6)-α-D-Glcp-(1 → and/or α-D-Glcp-(1 → residues. Surface morphological analysis revealed that ASPN-1 is an archetypal amorphous powder with an irregular network architecture composed of lamellar thin layers, filaments, and spherical particles. In vivo anti-tumor experiments indicated that ASPN-1 exerted inhibitory effects on CT26.WT mouse tumors by preserving immune function, elevating the production of IL-2, IFN-γ and TNF-α, and reducing production of TGF-β and IL-10. These findings indicated that ASPN-1, derived from A. senticosus, could potentially be used to treat colorectal carcinomas, acting through its immunomodulatory actions.

Plant polysaccharides and antioxidant benefits for exercise performance and gut health: from molecular pathways to clinic

In the last three decades, our understanding of how exercise induces oxidative stress has significantly advanced. Plant polysaccharides, such as dietary fibers and resistant starches, have been shown to enhance exercise performance by improving energy metabolism, reducing fatigue, increasing strength and stamina, mitigating oxidative stress post-exercise, facilitating muscle recovery, and aiding in detoxification. Moreover, antioxidants found in plant-based foods play a crucial role in protecting the body against oxidative stress induced by intense physical activity. By scavenging free radicals and reducing oxidative damage, antioxidants can improve exercise endurance, enhance recovery, and support immune function. Furthermore, the interaction between plant polysaccharides and antioxidants in the gut microbiota can lead to synergistic effects on overall health and performance. This review provides a comprehensive overview of the current research on plant polysaccharides and antioxidants in relation to exercise performance and gut health.

Construction and performance evaluation of polyguluronic acid polysaccharides-based drug delivery systems

Polysaccharides have garnered significant attention as potential nanoparticle carriers for targeted tumor therapy due to their excellent biodegradability and biocompatibility. Polyguluronic acid (PG) is a homogeneous acidic polysaccharide fragment derived from alginate, which is found in brown algae, possesses excellent bioactivities, unique properties. This study explored the immunomodulatory activity of PG and developed PG-based nanogels through modified disulfide bonds and Ca2+ dual crosslinking. We characterized their structure, assessed their drug-loading and release properties, and ultimately validated both the safety of the nanocarrier and the in vitro anti-tumor efficacy of the encapsulated drug. Results indicated that PG significantly enhanced the proliferative activity and phagocytosis of RAW264.7 cells while promoting reactive oxygen species (ROS) production and cytokine secretion. The study identified TLR4 as the primary receptor for PG recognition in RAW264.7 cells. Furthermore, PG-based drug-carrying nanogels were prepared, exhibiting uniform sizes of about 184 nm and demonstrating exceptional encapsulation efficiency (82.15 ± 0.82 %) and drug loading capacity (8.12 ± 0.08 %). In vitro release experiments showed that these nanogels could responsively release drugs under conditions of high glutathione (GSH) reduction, facilitating drug accumulation at tumor sites and enhancing therapeutic efficacy. This research not only expands the application of PG in drug delivery systems but also provides valuable insights into leveraging natural immunomodulatory polysaccharides as carriers for targeted drug delivery.

Structural characterization of polysaccharides from Panax ginseng C. A. Meyer root and their triggered potential immunoregulatory and radioprotective activities

With people's increasing awareness of healthy diet, the diverse health-promoting functions of ginseng have been widely recognized. As one of the key functional components, ginseng polysaccharides have attracted increasing research interest. Here, three purified polysaccharide fractions, GPS-1a, GPS-1b, and GPS-2, were obtained from the root extract of Panax ginseng C. A. Meyer. Structurally, GPS-1a and GPS-1b were both linked in a → 6)-α-D-Glcp-(1 → pattern but composed of glucose and galactose in molar ratios of 9.76:0.24 and 9.81:0.19. In contrast, GPS-2 was composed of glucose, galactose, arabinose, rhamnose, and galacturonic acid in a molar ratio of 1.82:1.94:0.79:0.52:4.93. The main backbone consisted of →4)-α-D-GalpA-(1→, →4)-α-D-GalpA-6OMe-(1→, →3, 4)-α-D-GalpA-(1→, →3)-α-L-Rhap-(1 → linages, and its branches are composed of →5)-α-L-Araf-(1→, →4)-β-D-Galp-(1→, →2)-β-D-Glcp-(1→, α-D-GalAp-(1→. Benefitting from this structural variance, GPS-2 exhibited the most significant immunoregulatory and radioprotective efficacies. Specifically, GPS-2 promoted TLR2, NF-κB, and TRAF6 protein expression levels, thereby significantly improving macrophage phagocytosis, splenic lymphocyte proliferation, and stimulation of NO, IL-1β, IL-6, and TNF-α secretion, which activated RAW264.7 and splenic lymphocytes. The following radioprotection activity tests unveiled that GPS-2 increased the organ index, number of peripheral blood cells, cellularity of splenocytes, and bone marrow cell numbers in irradiated mice. This investigation revealed the contribution of polysaccharide structure characteristics to the bioactive expression and elucidated the potential utilization of GPS-2 as a radioprotective agent or immunomodulator.

Immunomodulatory Effect of Cordyceps militaris Polysaccharide on RAW 264.7 Macrophages by Regulating MAPK Signaling Pathways

Polysaccharide is one of the principal bioactive components found in medicinal mushrooms and has been proven to enhance host immunity. However, the possible mechanism of immunomodulatory activity of Cordyceps militaris polysaccharide is not fully understood. Hot water extraction and alcohol precipitation, DEAE-Sephadex A-25 chromatography, and Sephadex G-100 chromatography were used to isolate polysaccharide from C. militaris. A high-molecular-weight polysaccharide isolated from C. militaris was designated as HCMP, which had an Mw of 6.18 × 105 Da and was composed of arabinose, galactose, glucose, mannose, and xylose in a mole ratio of 2.00:8.01:72.54:15.98:1.02. The polysaccharide content of HCMP was 91.2% ± 0.16. The test in vitro showed that HCMP activated mouse macrophage RAW 264.7 cells by enhancing phagocytosis and NO production, and by regulating mRNA expressions of inflammation-related molecules in RAW 264.7 cells. Western blotting revealed that HCMP induced the phosphorylation of mitogen-activated protein kinases (MAPKs). Moreover, using inhibitors of MAPKs decreased the mRNA levels of inflammation-related molecules induced by HCMP. These data evidenced that the immunomodulatory effect of HCMP on RAW 264.7 macrophages was mediated via the MAPK signaling pathway. These findings suggested that HCMP could be developed as a potent immunomodulatory agent for use in functional foods and dietary supplements.

Polysaccharides from Basella alba Protect Post-Mitotic Neurons against Cell Cycle Re-Entry and Apoptosis Induced by the Amyloid-Beta Peptide by Blocking Sonic Hedgehog Expression

The amyloid-beta peptide (Aβ) is the neurotoxic component in senile plaques of Alzheimer's disease (AD) brains. Previously we have reported that Aβ toxicity is mediated by the induction of sonic hedgehog (SHH) to trigger cell cycle re-entry (CCR) and apoptosis in post-mitotic neurons. Basella alba is a vegetable whose polysaccharides carry immunomodulatory and anti-cancer actions, but their protective effects against neurodegeneration have never been reported. Herein, we tested whether polysaccharides derived from Basella alba (PPV-6) may inhibit Aβ toxicity and explored its underlying mechanisms. In differentiated rat cortical neurons, Aβ25-35 reduced cell viability, damaged neuronal structure, and compromised mitochondrial bioenergetic functions, all of which were recovered by PPV-6. Immunocytochemistry and western blotting revealed that Aβ25-35-mediated induction of cell cycle markers including cyclin D1, proliferating cell nuclear antigen (PCNA), and histone H3 phosphorylated at Ser-10 (p-Histone H3) in differentiated neurons was all suppressed by PPV-6, along with mitigation of caspase-3 cleavage. Further studies revealed that PPV-6 inhibited Aβ25-35 induction of SHH; indeed, PPV-6 was capable of suppressing neuronal CCR and apoptosis triggered by the exogenous N-terminal fragment of sonic hedgehog (SHH-N). Our findings demonstrated that, in the fully differentiated neurons, PPV-6 exerts protective actions against Aβ neurotoxicity via the downregulation of SHH to suppress neuronal CCR and apoptosis.

Structural characterization of squash polysaccharide and its effect on STZ-induced diabetes mellitus model in MIN6 cells

A novel natural water-soluble acidic polysaccharide (PWESP-3) was isolated from squash with a molecular mass of 140.519 kDa, which was composed of arabinose (Ara, 35.30 mol%), galactose (Gal, 61.20 mol%), glucose (Glc, 1.80 mol%), and Mannuronic acid (ManA, 1.70 mol%) and contained Araf-(1→, →3)-Araf-(1→, →5)-Araf-(1→, Glcp-(1→, Galp-(1→, →3,5)-Araf-(1→, →2)-Glcp-(1→, →2)-Manp-(1→, →3)-Glcp-(1→, →4)-Galp-(1→, →3)-Galp-(1→, →6)-Galp-(1→, →3,4)-Galp-(1→, →4,6)-Galp-(1→ residues in the backbone. Moreover, the structure of PWESP-3 was identified by NMR spectra. The branch chain was connected to the main chain by the O-3 and O-4 atom of Gal. In addition, the effect of PWESP-3 on STZ-induced type I diabetes mellitus model in MIN6 cells was investigated. The results showed that PWESP-3 can increase the viability and insulin secretion of MIN6 cells and reduce the oxidative stress caused by ROS and NO. Meanwhile, PWESP-3 can also reduce the content of ATP, Ca2+, mitochondrial membrane potential and Caspase-3 activity in MIN6 cells. Furthermore, treatment with PWESP-3 can prevent single or double stranded DNA breaking to form DNA fragments and improve DNA damage in MIN6 cells, thereby avoiding apoptosis. Therefore, the above data highlight that PWESP-3 can improve the function of insulin secretion in STZ-induced MIN6 cells in vitro and can be used as an alternative food supplement to diabetes drugs.

Comprehensive Assessment of Polysaccharides Extracted from Squash by Subcritical Water under Different Conditions

The effects of subcritical water microenvironment on the physiochemical properties, antioxidant activity and in vitro digestion of polysaccharides (SWESPs) from squash were investigated. After single-factor experiments, twenty samples were successfully prepared at different extraction temperatures (110, 130, 150, 170 and 190 °C) and extraction times (4, 8, 12 and 16 min). Under a low temperature environment, the whole process was mainly based on the extraction of SWESP. At this time, the color of SWESP was white or light gray and the molecular mass was high. When the temperature was 150 °C, since the extraction and degradation of SWESP reached equilibrium, the maximum extraction rate (18.67%) was reached at 150 °C (12 min). Compared with traditional methods, the yield of squash SWESP extracted by subcritical water was 3-4 times higher and less time consuming. Under high temperature conditions, SWESPs were degraded and their antioxidant capacity and viscosity were reduced. Meanwhile, Maillard and caramelization reactions turned the SWESPs yellow-brown and produced harmful substances. In addition, different SWESPs had different effects on in vitro digestion. In brief, SWESPs prepared under different conditions have different structures and physicochemical properties, allowing the obtainment of the required polysaccharide. Our results show that squash polysaccharides prepared in different subcritical water states had good development potential and application in the food industry.

Effects of Flammulina velutipes polysaccharide with ice recrystallization inhibition activity on the quality of beef patties during freeze-thaw cycles: An emphasis on water status and distribution

The antifreeze activity of Flammulina velutipes polysaccharide (FVP) autoclave-extracted with dilute alkaline and effects of FVP on moisture status, size of ice crystals, physical and chemical characteristics of beef patties during repeated freeze-thaw (F-T) cycles were investigated. Results showed that FVP exhibited ice recrystallization inhibition activity and was able to alter the onset freezing/melting temperature of beef patties. 0.01% FVP significantly alleviated (P < 0.05) the decrement in water holding capacity by inhibiting water migration, restraining the mobility of water, and reducing the size of ice crystals of beef patties during the repeated F-T cycles. In addition, FVP could effectively inhibited oxidation reaction and protein aggregation of beef patties with significant decreases in TBARS value, protein turbidity, contents of total sulfhydryl and carbonyl of myofibrillar protein, and an increase in protein solubility during the repeated cycles. These results suggest FVP could be developed to be a promising cryoprotectant in frozen patties.

Specific molecular weight of Lycium barbarum polysaccharide for robust breast cancer regression by repolarizing tumor-associated macrophages

The pro-tumorigenic M2-type tumor-associated macrophages (TAMs) in the immunosuppressive tumor microenvironment (TME) promote the progression, angiogenesis, and metastasis of breast cancer. The repolarization of TAMs from an M2-type toward an M1-type holds great potential for the inhibition of breast cancer. Here, we report that Lycium barbarum polysaccharides (LBPs) can significantly reconstruct the TME by modulating the function of TAMs. Specifically, we separated four distinct molecular weight segments of LBPs and compared their repolarization effects on TAMs in TME. The results showed that LBP segments within 50-100 kDa molecular weight range exhibited the prime effect on the macrophage repolarization, augmented phagocytosis effect of the repolarized macrophages on breast cancer cells, and regression of breast tumor in a tumor-bearing mouse model. In addition, RNA-sequencing confirms that this segment of LBP displays an enhanced anti-breast cancer effect through innate immune responses. This study highlights the therapeutic potential of LBP segments within the 50-100 kDa molecular weight range for macrophage repolarization, paving ways to offer new strategies for the treatment of breast cancer.

A neutral polysaccharide from Persicaria hydropiper (L.) Spach ameliorates lipopolysaccharide-induced intestinal barrier injury via regulating the gut microbiota and modulating AKT/PI3K/mTOR and MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Persicaria hydropiper (L.) Spach, a herb that is prevalent across Asia and Europe, finds utility as both a culinary ingredient and medicinal herb. In China, P. hydropiper decoction is commonly employed to alleviate dysentery, gastroenteritis, and diarrhea symptoms.

AIM OF THE STUDY

To assess the effects of a neutral polysaccharide from P. hydropiper (PHP) on the intestinal barrier (IB) injury induced by lipopolysaccharide (LPS) in mice, and elucidate the molecular mechanisms involved.

MATERIALS AND METHODS

PHP was extracted from dried P. hydropiper herb using hot water extraction, followed by ethanol precipitation. The extract underwent successive isolation and purification steps involving anion-exchange and gel filtration chromatography. The primary structure of PHP was determined using Fourier-transformed infrared spectroscopy, ion chromatography, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. Male BALB/c mice were randomly assigned to control (CON), model (MOD), berberine hydrochloride (BBR), and PHP (20, 40 and 80 mg/kg) groups. Histopathological changes in jejunal tissues were assessed through hematoxylin and eosin (HE) staining. The expression levels of proteins and genes involved in AKT/PI3K/mTOR and MAPK signaling pathways were evaluated using qRT-PCR and Western blotting, respectively. The composition and abundance of the gut microbiota in mice were analyzed using high-throughput 16S rRNA gene sequencing. Additionally, the concentrations of short-chain fatty acids (SCFAs) were determined using GC-MS.

RESULTS

The main components of PHP included arabinose, galactose, and glucose (molar ratio = 1.00:5.52:11.39). The backbone of PHP consisted of →4)-Glcp-(1→, →4,6)-Glcp-(1→, →4)-Galp-(1→, →4,6)-Galp-(1→. The branched chains primarily consisted of 5)-Araf-(1→ residues, which were attached to the backbone through →6)-Glcp-(1→ and →6)-Galp-(1→ at the 6-position. Histological analysis demonstrated that PHP exhibited a mitigating effect on intestinal damage induced by LPS. PHP could markedly reduce the mRNA levels of PI3K, AKT, mTOR, p70 S6K, Ras, Raf1, MEK1/2, p38, ERK1/2, and JNK, while downregulating the protein levels of p-mTOR, p-PI3K, p-AKT, p-p38, p-ERK, and p-JNK. PHP also modulated the diversities and abundances of the gut microbiota, resulting in an increase in the abundances of Lactobacillaceae, Anaerovoracaceae, Lachnospiraceae, Eggerthellaceae, and Desulfovibrionaceae and a decrease in the abundances of Muribaculaceae, Prevotellaceae, and Rikenellaceae. Additionally, PHP significantly increased the content of various SCFAs.

CONCLUSION

PHP emerges as a pivotal factor in the repair of IB injury by virtue of its ability to regulate the gut microbiota, elevate SCFA levels, and inhibit the MAPK and AKT/PI3K/mTOR pathways. It is worth noting that the therapeutic effect of high-dose PHP was remarkably significant, surpassing even the positive control of berberine hydrochloride.

Ultrasound-assisted polysaccharide extraction from Fritillaria ussuriensis Maxim. and its structural characterization, antioxidant and immunological activity

Fritillaria ussuriensis Maxim. (F.M.) has been widely used in both food and medication for more than 2000 years. In order to achieve its comprehensive utilization and investigate the structural characterization and biology activity, response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction conditions of F.M. polysaccharides. The optimal extraction conditions were ultrasonic power of 174.2 W, ratio of liquid to material of 40.7 mL/g and ultrasonic time of 82.0 min. In addition, a neutral polysaccharide F-1 was obtained, and its structure characterization, antioxidant and immunological activity were evaluated. The structural properties of the polysaccharide were characterized by UV, IR, GC-MS, NMR and AFM. Monosaccharide composition of F-1 (MW 18.11 kDa) was rhamnose, arabinose, glucosamine hydrochloride, galactose, and glucose which under the ratio of 0.9: 3.8: 0.2: 2.9: 92.2. The fractions of F-1 were mainly linked by → 6)-α-D-Glcp-(1 → with branch chain α-D-Glcp-(1 → 4)-α-D-Glcp-(1 → and 4,6)-α-D-Glcp-(1 → residues. Moreover, F-1 has a significant scavenging activity, which can clear hydroxyl radicals, superoxide anion, DPPH and ABTS. In addition, the immunological activity showed that F-1 had an effect on macrophage phagocytic activity. And it can increase the release of inflammatory factors including TNF-α, IL-1β and IL-6. F-1 is a novel polysaccharide with significant activity in antioxidant and immunological activity, which has great potential for antioxidant and immunizer in food, pharmaceutical and cosmetic industries. The study can provide a methodological basis for polysaccharide research and theoretical basis for the industrialized production and practical application.

Structural characterization, α-glucosidase inhibitory activity and antioxidant activity of neutral polysaccharide from apricot (Armeniaca Sibirica L. Lam) kernels

Screening for α-glucosidase inhibitors and antioxidants from natural sources that could reduce postprandial glucose in diabetic patients and reduce oxidative stress had attracted considerable interest. In this study, a neutral polysaccharide (AP-1) with a triple helix structure was isolated and purified from the residue of apricot (Armeniaca sibirica L. Lam.) kernels by using DEAE-52 and Sephadex G-100 columns. The molecular weight of AP-1 was 23.408 kDa and consisted mainly of glucose with trace amounts of arabinose, galactose, and mannose, which had molar percentages of 98.48, 0.63, 0.62 and 0.27 %, respectively. The main chain of AP-1 was composed of →4)-α-D-Glcp-(1 → interlinked, and α-D-Glcp-(1 → was attached as a branched chain at the O-6 position of →4,6)-α-D-Glcp-(1→. In addition, AP-1 exhibited stronger α-glucosidase inhibition and free radical scavenging ability compared to crude polysaccharides. Therefore, AP-1 could be used as a potential natural hypoglycemic agent and antioxidant in the treatment of diabetes mellitus.

Purification, structural characterization and antioxidant activities of two neutral polysaccharides from persimmon peel

Two neutral polysaccharides (PPP1-1 and PPP1-2) were purified from persimmon peel. PPP1-1 (21.84 kDa) was mainly composed of arabinose (22.92 %), galactose (21.09 %), glucose (35.13 %), and xylose (19.09 %), while PPP1-2 (10.42 kDa) mainly contained arabinose (32.98 %), galactose (20.81 %), glucose (26.86 %), xylose (10.46 %), and mannose (7.63 %). Methylation and NMR spectra analysis demonstrated that the backbone of PPP1-1 appeared to be →6)-α-D-Glcp-(1→, →2,6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,5)-α-L-Araf-(1 → residues with branches consisting of →3)-α-L-Araf-(1→, →4)-α-D-Glcp-(1→, →3)-β-D-Galp-(1→, →4)-β-D-Galp-(1→, →4)-β-D-Xylp-(1→, →6)-β-D-Galp-(1→, →4)-β-D-Manp-(1→, and α-L-Araf-(1 → residues. The main chain of PPP1-2 was composed of →6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,5)-α-L-Araf-(1 → residues with branches consisting of →3)-α-L-Araf-(1→, →1,2)-α-D-Glcp-(6→, →4)-α-D-Glcp-(1→, →3)-β-D-Galp-(1→, →4)-β-D-Galp-(1→, →6)-β-D-Galp-(1→, →4)-β-D-Xylp-(1→, →4,6)-α-D-Glcp-(1→, and →4)-β-D-Manp-(1 → residues and terminal of α-L-Araf-(1 → residue. PPP1-2 exhibited stronger antioxidant activities and better thermal stability than PPP1-1. Our results provided the foundation for further investigating the structure and biological activities of persimmon peel polysaccharides and highlighted their potential to become potential antioxidants in functional food.

A review on biochemical constituents of pumpkin and their role as pharma foods; a key strategy to improve health in post COVID 19 period

Progression of today’s world has been given setback due to the adversity of a novel, viral, deadly outbreak COVID 19, which raised the concerns of the scientists, researchers and health related officials about the inherent and adaptive immune system of the living body and its relation with healthy diet balanced with pharma foods. Now world is coming out of the destructive pandemic era, the choice of right food can help to build and boost adaptive immunity and pumpkin due to excellent profile of functional and nutraceutical constituents could be the part of both infected and non-infected person’s daily diet. Vitamins like A, C and E, minerals like zinc, iron and selenium, essential oils, peptides, carotenoids and polysaccharides present in pumpkin could accommodate the prevailing deficiencies in the body to fought against the viral pathogens. In current post COVID 19 scenario adequate supply of healthy diet, balanced with pharma foods could play a basic role in boosting immune system of the populations. This review covers the pharmacological activities of pumpkin functional constituents in relation with COVID 19 pandemic. Pumpkins are well equipped with nutraceuticals and functional bioactives like tocopherols, polyphenols, terpenoids and lutein therefore, consumption and processing of this remarkable vegetable could be encouraged as pharma food due to its antihyperlipidemic, antiviral, anti-inflammatory, antihyperglycemic, immunomodulatory, antihypertensive, antimicrobial and antioxidant potential. Need of healthy eating in current post COVID 19 period is very crucial for healthy population, and medicinal foods like pumpkin could play a vital role in developing a healthy community around the globe.

Structural diversity and physicochemical properties of polysaccharides isolated from pumpkin (Cucurbita moschata) by different methods

Natural polysaccharides were isolated and purified from Cucurbita moschata by hot water extraction and mild acid-base sequential extraction. Chemical and instrumental studies revealed that hot water-extracted and mild acid-extracted polysaccharides with molecular masses of 48 kDa and 85 kDa were both pectic polysaccharides with homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) domains, while mild acid-extracted polysaccharide was more dominated by branched RG-I with higher contents of galactose (10.59 %) and arabinose (8.08 %). Furthermore, mild acid-extracted polysaccharide exhibited better thickening and emulsifying properties, likely due to its larger molecular mass and higher branching degree. Mild base-extracted polysaccharide with a molecular mass of 18 kDa was a glucan-like polysaccharide. It showed the strongest thermostability and gel behavior among these pumpkin polysaccharides, likely attributed to its unique network structure stabilized by substantial intra/intermolecular hydrogen bonds. This study aimed to establish the structure-property relationships between these structurally diverse pumpkin polysaccharides from different extraction methods and provided theoretical foundations for their targeted application in foods.

Physicochemical properties and prebiotic activities of polysaccharides from Zizyphus jujube based on different extraction techniques

Zizyphus jujube polysaccharide was extracted with hot water, ultrahigh pressure, deep eutectic solvent (DES) and ultrahigh pressure-assisted DES. Comparative analyses were conducted on the yield, physicochemical properties and prebiotic activity of four polysaccharides (JP-H, JP-U, JP-D and JP-UD). The yield of JP-UD (10.42 %) was 3.3 times that of JP-H (3.12 %), and its sugar content was the highest. JP-UD possessed the lowest Mw, while JP-H possessed the highest. Four JPs were acidic pyranose and mainly composed of galacturonic acid, arabinose and galactose. NMR results demonstrated that they contained not only similar glycosidic linkage but also the specific glycosidic linkage of →4)-α-D-Glcp-(l→ appeared in JP-U and JP-UD, the esterified units of GalA and CONH₂ group appeared in JP-D and JP-UD, and the Terminal β-D-Galp and →4)-α-GalpA-(1→ appeared in JP-UD. JPs showed different proliferation effects on four lactobacillus strains, among which JP-UD exhibited the strongest prebiotic activity. Zizyphus jujube polysaccharides have great potential for application in the functional food and medical industry.

The Therapeutic Potential of Plant Polysaccharides in Metabolic Diseases

Plant polysaccharides (PPS) composed of more than 10 monosaccharides show high safety and various pharmacological activities, including immunoregulatory, antitumor, antioxidative, antiaging, and other effects. In recent years, emerging evidence has indicated that many PPS are beneficial for metabolic diseases, such as cardiovascular disease (CVD), diabetes, obesity, and neurological diseases, which are usually caused by the metabolic disorder of fat, sugar, and protein. In this review, we introduce the common characteristics and functional activity of many representative PPS, emphasize the common risks and molecular mechanism of metabolic diseases, and discuss the pharmacological activity and mechanism of action of representative PPS obtained from plants including Aloe vera, Angelica sinensis, pumpkin, Lycium barbarum, Ginseng, Schisandra chinensis, Dioscorea pposite, Poria cocos, and tea in metabolic diseases. Finally, this review will provide directions and a reference for future research and for the development of PPS into potential drugs for the treatment of metabolic diseases.

Peucedanum praeruptorum Dunn polysaccharides regulate macrophage inflammatory response through TLR2/TLR4-mediated MAPK and NF-κB pathways

The present study was to investigate the molecular mechanisms underlying macrophage inflammatory response to polysaccharides from Peucedanum praeruptorum Dunn (PPDs) and elucidate the receptors and signaling pathways associated with PPDs-mediated macrophage activation. MTT and Griess method were performed to investigate the effects of PPDs on cell viability and NO production. Neutral red and FITC-dextran were used to determine the pinocytic and phagocytic activity. RT-qPCR and ELISA were employed to analyze the mRNA expression of inflammatory factors and production of cytokines and chemokines. RNA-seq and bioinformatics analysis were conducted to determine the underlying molecules, regulators and pathways, which were further validated by pathway inhibition and neutralization assays. The results indicated that PPDs significantly enhanced pinocytic and phagocytic activity, promoted the expression and secretion of inflammatory factors and chemokines, and boosted the expression of accessory and costimulatory molecules. RNA-Seq analysis identified 1343 DEGs, 405 GO terms and 91 KEGG pathways. IL6 and TNF were identified as hubs of connectivity in PPDs-mediated macrophage activation. "Cytokine-cytokine receptor interaction", "TNF signaling pathway", "NF-kappa B signaling pathway", "JAK-STAT signaling pathway" and "MAPK signaling pathway" were the most significant pathways. The pathway inhibition assay revealed that MAPK and NF-κB pathways were essential to macrophage activation by PPDs. TLR2 and TLR4 were uncovered to be the functional receptors and involved in recognition of PPDs. These results indicated that PPDs modulated macrophage inflammatory response mainly through TLR2/TLR4-dependent MAPK and NF-κB pathways.

Structure of a unique fucose-containing exopolysaccharide from Sayram ketteki yoghurt and its anti-MRSA biofilm effect

In this work, we reported an in situ exopolysaccharide (in situ-EPS1) containing rare fucose produced by Lactobacillus helveticus MB2-1 in Sayram ketteki yoghurt, which made it unique. Its fine structure was characterized by GPC, HPLC, FT-IR, GC-MS,¹HNMR and ¹³CNMR together with two-dimensional (2D) NMR spectra. The results revealed that in situ-EPS1 was a new heteropolysaccharide with molecular weight of 1.06 × 10⁵ Da, and was composed of mannose, rhamnose, glucose, galactose and fucose with the following repeating units. Furthermore, the in situ-EPS1 exhibited significant antibiofilm effect against Methicillin-resistant Staphylococcus aureus (MRSA). Notably, the in situ-EPS1 did not interfere with the planktonic growth of MRSA strain, whereas inhibited its cell metabolic activity and the transcription of genes related to biofilm formation. This unique antibiofilm but non-antibacterial mechanism supposedly prevented the development of bacterial drug resistance, which may open a new door to fight against these drug-resistant microorganisms.

Structural characterization and immunoregulatory activity of a novel acidic polysaccharide from Scapharca subcrenata

A novel acidic polysaccharide named SSPA50-1 was isolated from Scapharca subcrenata using a simulated gastric fluid extraction method. SSPA50-1 is a heteropolysaccharide with an average molecular weight of 44.7 kDa that is composed of galacturonic acid, glucose, galactose, mannose, ribose, rhamnose, fucose, xylose and arabinose at a molar ratio of 1.00:5.40:9.04:3.10:1.59:4.01:2.10:2.21:2.28. The structural characterization based on the methylation and 1D/2D NMR analyses indicated that SSPA50-1 is composed of →3)-β-L-Rhap-(1→, →3)-β-L-2-O-Me-Fucp-(1→, →2)-α-D-Xylp-(1→, →5)-α-L-Araf-(1→, →3)-β-D-Galp-(1→, →6)-α-D-Glcp-(1→, →3,4)-β-D-Manp-(1→, →3,4)-β-D-Galp-(1→, β-D-Ribf-(1→, α-D-Glcp-(1→, and α-D-GalAp6Me-(1→. Furthermore, SSPA50-1 possessed potent immunoregulatory activity by enhancing the phagocytosis and NO, iNOS, TNF-α and IL-6 secretion capacity of RAW264.7 cells. Otherwise, SSPA50-1 significantly promoted the proliferation of splenic lymphocytes and RAW264.7 macrophages. These results indicated that SSPA50-1 could be developed as a potential ingredient for immunostimulatory agents.

Homogalacturonan from squash: Characterization and tau-binding pattern of a sulfated derivative

A pectic polysaccharide (WAP) was isolated from squash and identified as a homogalacturonan with a molecular mass of 83.2 kDa by GPC, monosaccharide composition analysis, FT-IR and NMR spectra. Sulfation modification of WAP was carried out and a sulfated derivative (SWAP) was obtained with a substitution degree of 1.81. The NMR spectrum indicated that the sulfation modification mainly occurred at the C-2 and C-3 positions of galacturonan residues. The binding pattern of SWAP to tau K18 protein was observed in 2D 1H15N HSQC spectra of tau, which resembled the tau-heparin interaction, with R2 domain as the major binding region. These results suggest that SWAP has the potential to act as a heparin mimic to inhibit the transcellular spread of tau; thus natural polysaccharide from squash may be developed into therapies for AD and related tauopathies.