Characterization, antioxidant and immunomodulatory effects of selenized polysaccharides from dandelion roots

Natural polysaccharides and their derivatives targeting the tumor microenvironment: A review

Polysaccharides have gained attention as valuable supplements and natural medicinal resources, particularly for their anti-tumor properties. Their low toxicity and potent anti-tumor effects make them promising candidates for cancer prevention and treatment. The tumor microenvironment is crucial in tumor development and offers potential avenues for novel cancer therapies. Research indicates that polysaccharides can positively influence the tumor microenvironment. However, the structural complexity of most anti-tumor polysaccharides, often heteropolysaccharides, poses challenges for structural analysis. To enhance their pharmacological activity, researchers have modified the structure and properties of natural polysaccharides based on structure-activity relationships, and they have discovered that many polysaccharides exhibit significantly enhanced anti-tumor activity after chemical modification. This article reviews recent strategies for targeting the tumor microenvironment with polysaccharides and briefly discusses the structure-activity relationships of anti-tumor polysaccharides. It also summarises the main chemical modification methods of polysaccharides and discusses the impact of chemical modifications on the anti-tumor activity of polysaccharides. The review aims to lay a theoretical foundation for the development of anti-tumor polysaccharides and their derivatives.

Effects of almond (Armeniaca Sibirica L. Lam) polysaccharides on gut microbiota and anti-inflammatory effects on LPS-induced RAW264.7 cells

The aim of this study was to investigate the prebiotic properties of the almond polysaccharide AP-1 on intestinal microorganisms by using an in vitro fecal fermentation method and its anti-inflammatory effect on lipopolysaccharide (LPS)-induced RAW264.7 cells. The results showed that during the in vitro fermentation of AP-1, the pH value of the fermentation broth decreased obviously, while the concentration of short-chain fatty acids (SCFAs) increased significantly, especially acetic acid and butyric acid. In genus level, the number of Clostridium and Megamonas increased markedly in the AP-1 group after 24 h of fermentation. After 48 h of fermentation, there was a noticeable increase in the number of beneficial genera Lactobacillaceae and Bifidobacteriaceae, and a considerable decrease in the number of pro-inflammatory genera. In addition, we found that AP-1 had no toxic effect on RAW264.7 cells. In the LPS-induced inflammation model of RAW264.7 cells, AP-1 could effectively inhibit the release of NO, regulate the level of reactive oxides (ROS), and effectively down-regulate the mRNA expression of TNF-α, IL-1β, IL-6 and iNOS. In conclusion, the almond polysaccharide AP-1 may be a functional active substance aimed at promoting intestinal health and exerting anti-inflammatory effects.

Preparation, characterization and cytotoxicity assessment of a novel selenized polysaccharide from Morchella sextelata

Selenylation modification has been widely developed to improve the biological effects of natural polysaccharides. In this study, a purified new polysaccharide (MSP-4) was isolated from Morchella Sextelata, and selenized into SeMSP-4 using the HNO3-Na2SeO3 method. The selenium (Se) content of SeMSP-4 was 101.81 ± 9.90 mg/kg, and the molecular weight of SeMSP-4 was 1.23 × 105 Da. The FT-IR, XRD and AFM results showed that MSP-4 was successfully combined with the Se element. The structure characters of SeMSP-4 were analyzed by methylation analysis combined with 1D and 2D NMR spectroscopy. And, the radical scavenging test revealed that SeMSP-4 exhibited higher antioxidant capacities in vitro than MSP-4. The cytotoxicity analysis indicated that SeMSP-4 could dose-dependently inhibit the proliferation of HepG2 and HeLa cells, but did not show a cytotoxic effect on normal cells (HEK293). Furthermore, SeMSP-4 stimulation significantly increased the macrophage viability and enhanced NO production in macrophage cells. This study suggested that SeMSP-4 could be utilized as a potential selenium source with antioxidant, antitumor, and immunostimulatory activities.

Dandelion polysaccharides improve the emulsifying properties and antioxidant capacities of emulsions stabilized by whey protein isolate

In this study, the effects of dandelion polysaccharide (DP) and its carboxymethylated derivative (CMDP) on the emulsifying characteristics and antioxidant capacities of emulsions stabilized by whey protein isolate (WPI) were determined. The addition of both DP and CMDP reduced the particle size and zeta potential of the emulsions. Using 1.0 % WPI and 1.0 % CMDP as emulsifier, the emulsifying activity index (EAI) and emulsifying stability index (ESI) were 32.61 ± 0.11 m2/g and 42.58 ± 0.13 min, respectively, which were higher than the corresponding values of 27.19 ± 0.18 m2/g and 36.17 ± 0.15 min with 1.0 % WPI and 1.0 % DP. Fourier-transform infrared spectroscopy (FT-IR), far-ultraviolet circular dichroism (Far-UV CD), and fluorescence (FS) spectra analyses confirmed that the α-helix and β-sheet structures in WPI-polysaccharide complexes were reduced compared with those in pure WPI, whereas the random-coil content was enhanced by the addition of polysaccharides. Moreover, DP and CMDP effectively improved the antioxidant capacity and inhibited oxidation of the emulsions during storage. Therefore, DP and its carboxymethylated derivative exhibit great potential to be applied in the emulsion-based delivery system.

Identification of carbohydrate in Polygonatum kingianum Coll. et Hemsl and inhibiting oxidative stress

The specific structure of Polygonatum kingianum Coll. et Hemsl polysaccharide (PKP) has been rarely reported. In this study, an inulin-type fructan PKP-1, was extracted and purified from Polygonatum kingianum Coll. et Hemsl, and its structural characteristics and antioxidants activity were evaluated. The molecular weights of PKP-1 was determined to be 4.802 kDa. Monosaccharide composition analysis evidenced that PKP-1 was composed of galactose, glucose and fructose in a molar ratio of 0.8 %:7.2 %:92.0 %. Glycosidic linkage and Nuclear Magnetic Resonance (NMR) analysis revealed that PKP-1 exhibited a primary sugar residue linkage of →1-β-d-Fruf-2→2,6-β-d-Fruf-1→, where β-d-Fruf-2→ acts as the side chain and links to the C-6 position of →2,6-β-d-Fruf-1→. In vitro antioxidant activity assays demonstrated that PKP-1 enhanced the mitigation of hepatic oxidative stress in HepG2 cells induced by free fatty acids. This effect was marked by increased enzymatic activities of superoxidase dismutase (SOD) and catalase (CAT), along with elevated glutathione (GSH) levels. These findings indicate that PKP-1 could be used as a potential natural antioxidant.

Structural characterization, antioxidant and antibacterial activity of three pectin polysaccharides from blueberry

In this study, three pectin polysaccharides BP1, BP2 and BP3, were purified from blueberries. The weight-average molecular weight (Mw) of BP1, BP2, and BP3 were detected to be 9.027 × 104, 9.313 × 104, and 1.223 × 106 Da, respectively. The structures of the three pectin polysaccharides were characterized and compared based on the results of molecular weight, monosaccharide composition, GC-MS and NMR analysis. Structural characterization revealed that BP1, BP2, and BP3 all contain homogalacturonan (HG) and rhamnogalacturonan I (RG-I) domains, and the rhamnose residues in RG-I domains are substituted at C-4 with side chains such as araban and galactosan. BP2 had the highest degree of esterification and HG domain ratio, followed by BP3 and BP1. In addition, BP1, BP2 and BP3 showed great antioxidant and antibacterial activities, and could destroy the cell membrane of Staphylococcus aureus and Escherichia coli. Moreover, the better DPPH and ABTS free radical scavenging and antibacterial activities of BP1 and BP2 than BP3 might be related to their lower molecular weight. The results of this study will provide essential information for the structure-activity relationship of pectin polysaccharides and research basis for development and application of blueberry pectin polysaccharides.

Taraxacum: A Review of Ethnopharmacology, Phytochemistry and Pharmacological Activity

Taraxacum refers to the genus Taraxacum, which has a long history of use as a medicinal plant and is widely distributed around the world. There are over 2500 species in the genus Taraxacum recorded as medicinal plants in China, Central Asia, Europe, and the Americas. It has traditionally been used for detoxification, diuresis, liver protection, the treatment of various inflammations, antimicrobial properties, and so on. We used the most typically reported Taraxacum officinale as an example and assembled its chemical makeup, including sesquiterpene, triterpene, steroids, flavone, sugar and its derivatives, phenolic acids, fatty acids, and other compounds, which are also the material basis for its pharmacological effects. Pharmacological investigations have revealed that Taraxacum crude extracts and chemical compounds contain antimicrobial infection, anti-inflammatory, antitumor, anti-oxidative, liver protective, and blood sugar and blood lipid management properties. These findings adequately confirm the previously described traditional uses and aid in explaining its therapeutic applications.

Extraction, purification, structural features, biological activities, modifications, and applications from Taraxacum mongolicum polysaccharides: A review

Dandelion (Taraxacum mongolicum Hand.-Mazz), as a famous medicinal and edible plant, has the effects of clearing heat and detoxifying, diuresis, and resolving masses. Phytochemistry investigations revealed that T. mongolicum has various bioactive ingredients, mainly including flavonoids, sterols, polysaccharides, phenolic acids and volatile oils. There is growing evidence have shown that the polysaccharides from T. mongolicum (TMPs) are a class of representative pharmacologically bioactive macromolecules with a variety of biological activities both in vitro and in vivo, such as immunomodulatory, anti-inflammatory, anti-oxidant, anti-tumor, hepatoprotective, hypolipidemic and hypoglycemic, anti-bacterial, regulation of intestinal microbial, and anti-fatigue activities, etc. Additionally, the structural modification and potential applications of TMPs were also outlined. The present review aims to comprehensively and systematically collate the recent research progress on extraction and purification methods, structural characteristics, biological activities, mechanism of action, structural modification, and potential industry applications of TMPs to support their therapeutic potential and health care functions. Overall, the present review provides a theoretical overview for further development and utilization of TMPs in the fields of pharmaceutical and health food.

Research on the application of Thelephora ganbajun exopolysaccharides in antioxidant, anti-inflammatory and spot-fading cosmetics

Thelephora ganbajun exopolysaccharides (TGEP) with a "coral-like" branched chain structure (main chain diameter ∼ 80 nm) were prepared by liquid fermentation and fractionated by ion-exchange chromatography. The main fraction (TGEP-2) with the highest in vitro antioxidant capacity was composed of Glc, Man, Gal, GalA, GlcA, Ara, Rha, GlcN, Fuc and Rib in a molar ratio of 465.43:420.43:219.14:188.43:37:35.14:31.43:19.43:11.14:1, with a molecular weight of 1.879 × 104 Da. The sequence of monosaccharide residue release revealed that Gal, Glc and Ara residues were more distributed in the side-branch chains and at their ends, whereas Man and GalA residues were more distributed in the main chains. TGEP-2 contained linear residues (mainly →4)-Glcp-(1 → and →4)-Manp-(1→), branch residues (→3,6)-Glcp-(1→, →4,6)-Glcp-(1 → and →3,6)-Galp-(1→) and terminal residues (Galp-(1→, Manp-(1 → and Glcp-(1→). TGEP-2 consisted of α- and β-glycosidically linked pyranosides, with a triple helical conformation and many long branches. Zebrafish oxidative stress and inflammation models found that TGEP-2 had antioxidant and anti-inflammatory activities. The zebrafish skin black spot assay showed that TGEP-2 inhibited melanin formation. Therefore, extracellular polysaccharides of T. ganbajun have strong application potential in anti-oxidant, anti-inflammatory and skin spot-fading functions cosmetics.

Effect of chemical modification of κ-carrageenan on its inhibitory effect against heterocyclic amine (HAs) formation in roasted tilapia fish patties

Sulfated κ-carrageenan (S-KC), carboxymethylated κ-carrageenan (C-KC), acetylated κ-carrageenan (A-KC) and phosphorylated κ-carrageenan (P-KC) were synthesized and tested for their inhibitory effect on heterocyclic amine (HAs) formation in roasted tilapia fish patties. Fish patties with 1 % of each hydrocolloid prepared by 90 % of fish and 10 % of an aqueous hydrocolloid dispersion were determined for HAs-levels after roasting. P-KC showed the strongest inhibitory effect against total HAs formation (20.95 %). Moreover, P-KC increased the content of creatinine and glucose but decreased the content of free amino acids in fish patties, indicating that P-KC may compete with creatinine and glucose to react with amino acids to suppress HAs generation. In addition, P-KC plus naringenin had a stronger inhibitory effect against HAs formation than P-KC or naringenin alone. P-KC at 1 % (w/w) and P-KC (0.5 %, w/w) plus naringenin (0.5 %, w/w) showed no significant effects on the color and textural properties compared to the control group (100 % fish), and had less impact on food quality than 1 % (w/w) KC. Therefore, our results suggest that chemical modification could enhance the inhibitory effect of some hydrocolloids on HAs formation, and an appropriate combination of hydrocolloids and flavonoids contributes to the attenuation of dietary exposure to genotoxic HAs.

Dandelion Polysaccharides Ameliorate High-Fat-Diet-Induced Atherosclerosis in Mice through Antioxidant and Anti-Inflammatory Capabilities

Dandelion (Taraxacum officinale), a member of the Asteraceae (Compositae) family, is well known as the traditional medical plant. Dandelion polysaccharides, a natural active ingredient extracted from the dandelion, possess immune regulation, anti-inflammatory, antioxidant, and anti-aggregation properties. These properties suggest that dandelion polysaccharides might alleviate atherosclerosis. Using an ApoE-/- atherosclerotic mice model fed a high-fat diet, we investigated the impact and potential mechanism of dandelion polysaccharides on atherosclerosis. We observed that dandelion polysaccharides significantly reduced the levels of triglyceride, total cholesterol, and low-density lipoprotein-cholesterol in serum, while elevated the high-density lipoprotein-cholesterol level. Concomitantly, dandelion polysaccharides reduced the area of atherosclerotic lesions and necrotic core of the aortic sinus, and increased the collagen content. Mechanistic studies showed that dandelion polysaccharides were effective in reducing serum malondialdehyde levels while elevating the enzymatic activities of superoxide dismutase and glutathione peroxidase. Furthermore, dandelion polysaccharides reduced the expression of chemotactic factor Mcp-1 and pro-inflammatory cytokines (Tnf-α, Il-1β, and Il-6) in atherosclerotic lesions. Overall, these results indicated that dandelion polysaccharides may take an important part in the attenuation of atherosclerosis via its antioxidant and anti-inflammatory properties.

Structural characterization and antioxidant activity of processed polysaccharides PCP-F1 from Polygonatum cyrtonema Hua

Introduction

Polygonatum cyrtonema Hua. (PC) is a traditional Chinese herb with a history of use in both food and medicine. For clinical use, processed PC pieces are most commonly used, while present research has focused on crude PC polysaccharides (PCPs).

Methods

In this study, a new polysaccharide, PCP-F1, with a molecular weight of 37.46 kDa, was separated from four-time processed PCPs by column chromatography and evaluated by antioxidant activity. It was composed of glucose, mannose, galactose, rhamnose, and galacturonic acid with a molar ratio of 3.5: 2.5: 1.3: 1.8: 0.8.

Results and Discussion

The methylation analysis and two-dimensional NMR measurement revealed that the configuration of PCP-F1 contained nine residues in the primary structural unit by the chain of →3)-α-D-Glcp, →2)-α-D-Glcp (6→, →1)-ꞵ-D-Glcp (2→, →2)-α-D-GalAp (3,4→, →1) -ꞵ-D-Manp (3→, →2)-α-D-Glcp (3→, branched for →3)-α-D-Glcp, →2)-ꞵ-D-Galp (4→, →1)-ꞵ-D-Glcp (2→, →2,4)-α-D-Manp (6→, →3)-α-L-Rhap (4→. Radical scavenging assays indicated that PCP-F1 could scavenge radicals with a high scavenging rate, suggesting PCP-F1 possesses good antioxidant activity. The study confirms the importance of processed PC and offers the potential for exploiting it as a functional food.

Structural characterization and anti-oxidation activity of pectic polysaccharides from Swertia mileensis

In this study, we isolated the pectic polysaccharide WSMP-A2b (37 kDa) from the stems and leaves of Swertia mileensis, and we investigated its compositional/structural features and antioxidant activity. FT-IR, NMR, monosaccharide composition, enzymatic hydrolysis and methylation analyses indicated that WSMP-A2b is composed of rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II) and homogalacturonan (HG) domains with mass ratios of 2.1:1.0:2.2. The RG-I domain is primarily substituted with α-L-1,5-arabinan and type II arabinogalactan (AG-II) side chains, as well as minor contributions of β-D-1,4-galactan and/or type I arabinogalactan (AG-I) side chains. The HG domain was released in the form of un-esterified and partly methyl-esterified and/or acetyl-esterified oligogalacturonides with a 1 to 7 degree of polymerization after endo-polygalacturonase degradation. WSMP-A2b showed stronger antioxidant activity in vitro, in part this might due to the presence of galacturonic acid (GalA). In addition, WSMP-A2b exerted a protective effect on tert-butyl hydroperoxide (tBHP)-induced oxidative stress in INS-1 cells by reducing reactive oxygen species (ROS) production and increasing the glutathione/oxidized glutathione (GSH/GSSG) ratio. Our results provide crucial structural information on this pectic polysaccharide from Swertia mileensis, thus prompting further investigation into its structure-activity relationship.

Dandelion (Taraxacum Genus): A Review of Chemical Constituents and Pharmacological Effects

Dandelion (Taraxacum genus) is a perennial herb belonging to the Asteraceae family. As a well-known and extensively studied genus, dandelion comprises numerous species. Some species have been widely used in both complementary and alternative medicine to clear heat, detoxify, activate blood circulation, dispel stasis, and discharge urine. Multiple pharmacological studies have highlighted its therapeutic potential, including anti-bacterial, anti-oxidant, anti-cancer, and anti-rheumatic activities. Furthermore, bioactive compounds associated with these effects include sesquiterpenoids, phenolic compounds, essential oils, saccharides, flavonoids, sphingolipids, triterpenoids, sterols, coumarins, etc. Based on recent studies about the Taraxacum genus, the present review critically evaluates the current state of dandelion utilization and summarizes the significant roles of dandelion and its constituents in different diseases. We also focus on the reported phytology, chemical composition, pharmacology, and toxicity of dandelion, along with the main possible action mechanisms behind their therapeutic activities. Meanwhile, the challenges and future directions of the Taraxacum genus are also prospected in this review, thus highlighting its pharmaceutical research and practical clinical applications.

Flammulina velutipes polysaccharide counteracts cadmium-induced gut injury in mice via modulating gut inflammation, gut microbiota and intestinal barrier

Cadmium (Cd), as Group I carcinogen, can induce damage to various organs including the gut. It is of great importance to meet the rising demand for effective therapies against Cd-induced damage and investigate the mechanism. Flammulina velutipes is a popular edible mushroom, despite the well-known health benefits of Flammulina velutipes, little is known about the effect of its polysaccharide (FVP) against CdCl₂-intestinal injury. In this study, a FVP (uronic acid, 5.10 %; degree of methylation, 41.24 %) was produced via hot water extraction (85 °C) and ethanol precipitation. The FVP contained eight major monosaccharides and exhibited good thermal stability at temperatures lower than 139.73 °C. FVP (100 mg/kg b. w., gavage for 4 weeks) alleviated CdCl₂ (1.5 mg/kg b. w., gavage for 4 weeks)-induced intestinal inflammation and apoptosis, intestinal permeability alteration and intestinal barrier disruption. FVP increased the abundance of Bacteroides, whilst decreasing the abundance of Desulfovibrionales and Clostridium. FVP also restored the levels of short-chain fatty acids (SCFAs), including acetic, propionic, isobutyric, butyric, isovaleric and valeric acids. Correlation analysis indicated the interplays among the FVP, gut microbes, SCFAs, intestinal barrier/cells and gut inflammation. FVP enhances the metabolic functions of gut microbiota via functional pathways analyzed by KEGG database. Furthermore, gut microbial transplantation of FVP + CdCl₂ group mice partially alleviated CdCl₂ caused-gut damage. Thus, FVP may be an effective therapeutic agent against CdCl₂-induced gut damage via SCFA-mediated regulation of intestinal inflammation and gut microbiota-related energy metabolism. This study may open a new avenue for developing alternative strategies to prevent CdCl₂-caused injury.

Carboxymethylation modification, characterization of dandelion root polysaccharide and its effects on gel properties and microstructure of whey protein isolate

In the present study, a native polysaccharide (DP) with sugar content of 87.54 ± 2.01 % was isolated from dandelion roots. DP was chemically modified to obtain a carboxymethylated polysaccharide (CMDP) with DS of 0.42 ± 0.07. DP and CMDP were composed of the same six monosaccharides including mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose. The molecular weights of DP and CMDP were 108,200 and 69,800 Da, respectively. CMDP exhibited more stable thermal performance and better gelling properties than DP. The effects of DP and CMDP on the strength, water holding capacity (WHC), microstructure, and rheological properties of whey protein isolate (WPI) gels were investigated. Results showed that CMDP-WPI gels had higher strength and WHC than DP-WPI gels. With the addition of 1.5 % CMDP, WPI gel had a good three-dimensional network structure. The apparent viscosities, loss modulus (G"), and storage modulus (G') of WPI gels were increased with the polysaccharide addition, the influence of CMDP was remarkable compared to DP at the same concentration. These findings suggest that CMDP may be used as a functional ingredient in protein-containing food products.

Cordyceps militaris polysaccharide alleviates ovalbumin-induced allergic asthma through the Nrf2/HO-1 and NF-κB signaling pathways and regulates the gut microbiota

Polysaccharides, as one of the main types of bioactive components of Cordyceps militaris, have anti-allergic asthma effects. Herein, an ovalbumin-induced allergic asthma mouse model was established to assess the potential mechanisms of the separated and purified Cordyceps militaris polysaccharide (CMP). CMP is an α-pyranose with a molecular weight of 15.94 kDa that consists of Glc, Man, Gal, Xyl, Ara and GlcA in a molar ratio of 81.25:21.96:13.88:3.92:3.58:1.00. CMP improved inflammatory cytokine levels, alleviated the histopathological changes in the lung and intestinal tissues, regulated the expression of mRNA and proteins related to oxidative stress and inflammatory pathways, reversed gut dysbiosis at the phylum and family levels and improved microbiota function in allergic asthma mice. Moreover, it was found that the levels of inflammatory cytokines in lung tissue of mice were significantly correlated with some intestinal microbial communities. Overall, CMP improved oxidative stress and the inflammatory response in allergic asthma mice by regulating the Nrf2/HO-1 and NF-κB signaling pathways, which may be closely correlation with maintaining the stability of the gut microbiota.

Optimization of ultrasound-assisted aqueous two-phase extraction of polysaccharides from seabuckthorn fruits using response methodology, physicochemical characterization and bioactivities

BACKGROUND

Seabuckthorn fruits contains many active subtances, among them, the seabuckthorn polysaccharide is one of the main active ingredients, and exhibits diverse bioactivities. The extraction of polysaccharides from seabuckthorn fruits is the most important step for their wide applications. Ultrasound-assisted aqueous two-phase extraction (UA-ATPE) is a promising green method for extracting polysaccharides. Additionally, physicochemical characterization and antioxidant activities can evaluate the potential functions and applications in the food and medicine industries.

RESULTS

Based on the single-factor experiments, 20.70% (w/w) ammonium sulfate ((NH₄ )₂ SO₄ ) and 27.56% (w/w) ethanol were determined as the suitable composition for aqueous two-phase. The optimum conditions of UA-ATPE obtained by response surface methodology were as follows: ultrasonic power (390 W), extraction time (41 min), liquid-to-material ratio (72: 1 mL/g), and the total yield of the polysaccharides reached 34.14 ± 0.10%, The molecular weights of the purified upper-phase seabuckthorn polysaccharide (PUSP) and the purified lower-phase seabuckthorn polysaccharide (PLSP) were 65 525 and 26 776 Da, respectively. PUSP and PLSP contained the same six monosaccharides (galacturonic acid, rhamnose, xylose, mannose, glucose and galactose), but with different molar ratios. Furthermore, PUSP and PLSP displayed certain viscoelastic property, had no triple helical structure, possessed different thermal stability, surface morphology and conformation in aqueous solution. PUSP and PLSP displayed strong antioxidant properties by the assays of scavenging ability of ABTS⁺ ·, the protection of DNA damage and erythrocyte hemolysis.

CONCLUSION

UA-ATPE significantly increased the yield of seabuckthorn polysaccharides. PUSP and PLSP were different in many aspects, such as molar ratio, surface shape and antioxidant activities. Seabuckthornpolysaccharides possess great potential in medicine and functional foods. © 2022 Society of Chemical Industry.

Microanalysis Characterization and Immunomodulatory Effect for Selenium-Enriched Polysaccharide from Morchella esculenta (L.) Pers

Morchella esculenta (L.) Pers., referred to as Morel, is a medicinal and edible homologous fungus, which contains many bioactive substances. In Morel, polysaccharides are the most abundant and have various bioactivities. In the present work, two novel polysaccharides, Se-MPS and MPS, were prepared and purified from selenium-enriched (Se-enriched) and common Morel mycelia, respectively, and their structural and immunomodulatory properties were evaluated. The results show that Se-enriched treatment significantly changed the polysaccharides' chemical composition, molecular weight, and sugar chain configuration. In addition, the Se-enriched treatment also improved the polysaccharides' fragmentation and thermal stability. Importantly, Se-enriched Morel polysaccharide (Se-MPS) could significantly enhance phagocytosis of RAW 264.7 macrophage cells and, remarkably, activate their immune response via activating the TLR4-TRAF6-MAPKs-NF-κB cascade signaling pathway, finally exerting an immunomodulatory function. Based on these findings, selenium-enriched Morel polysaccharide appears to have more potential for development and utilization in functional foods or medicines than ordinary Morel polysaccharide.

Effects of dandelion root on rat heart function and oxidative status

This study aimed to examine the effects of dandelion root on rat heart function and oxidative status. At the beginning of the experimental protocol, Wistar albino rats were randomly classified into two groups (10 rats per group): 1. control group - animals that drank tap water; 2. experimental group - animals that drank dandelion root for four weeks. Every morning for four weeks, the animals received freshly boiled dandelion root in a volume of 250 ml. At the end of the dandelion administration, animals were sacrificed, and their hearts were isolated and retrogradely perfused according to the Langendorff technique at a gradually increasing perfusion pressure between 40 - 120 cm H₂O. The following myocardial function parameters were measured: maximum rate of left ventricular pressure development (dp/dt max), minimum rate of left ventricular pressure development (dp/dt min), systolic left ventricular pressure (SLVP), diastolic left ventricular pressure (DLVP), heart rate (HR). In addition, the coronary flow (CF) was measured flowmetrically. Finally, blood samples were collected after sacrificing to determine oxidative stress biomarkers: nitrite (NO₂^-), superoxide anion radical (O₂^-), hydrogen peroxide (H₂O₂), the index of lipid peroxidation (TBARS), reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD). The present pioneer results indicated that dandelion root did not manifest a negative impact on functional aspects of isolated rat heart. In addition, dandelion consumption was not associated with promising results in terms of maintaining systemic redox balance.

Preparation of nano-selenium from chestnut polysaccharide and characterization of its antioxidant activity

Chestnut is widely cultivated and has high nutritional value due to its richness in polysaccharides. In order to improve the antioxidant activity of chestnut polysaccharide, chestnut polysaccharide (CP) was extracted by ultrasonic-assisted water extraction and alcohol precipitation and purified by cellulose DEAE-52 exchange and Sephadex G-100 chromatography in this study. CP isolates were characterized by I₂-KI reaction, three-strand helical structure analysis, infrared spectrum analysis, and nuclear magnetic resonance detection. The results showed that CP is a pyrylan sugar with triple helical structure and connected by α-glycosidic bonds, with sugar residues 1,4-α-D-Glcp, 1,6-α-D-Galp, 1,5-α-L-Araf, 1,4-α-L-Rhap, and 1,4-β-D-Glcp in the CP backbone. After purification, the branching structure, rod, and spherical structure were significantly increased, with reduced lamellar structure. The in vitro scavenging rates of CP at 10 mg·mL^-1 against DPPH, hydroxyl radicals, and ABTS were 88.95, 41.38, and 48.16%, respectively. The DPPH free radical scavenging rate of purified polysaccharide fraction CP-1a was slightly enhanced, and the other rates showed a small decrease. Selenized chestnut polysaccharide (CP-Se) was prepared using nano-selenium method. The selenization method was optimized and stable Se-CP was obtained. When the concentration was 5 mg·mL^-1, Se-CP had significantly higher scavenging abilities 89.81 ± 2.33, 58.50 ± 1.60, and 40.66 ± 1.91% for DPPH, hydroxyl radical, and ABTS radicals, respectively, than those of CP. The results of this study provide insight into the effects purification and selenization of chestnut polysaccharide on antioxidant activity, and also provide a theoretical basis for the development of chestnut polysaccharide for use in functional foods or health products.

Preparation, characterization and bioactivities of selenized polysaccharides from Lonicera caerulea L. fruits

Native polysaccharide was obtained from Lonicera caerulea L. fruits (PLP). Two selenized polysaccharides (PSLP-1 and PSLP-2) were synthesized by the microwave-assisted HNO₃-Na₂SeO₃ method, where the selenium (Se) contents were 228 ± 24 and 353 ± 36 μg/g, respectively. The molecular weights of PLP, PSLP-1, and PSLP-2 were 5.9 × 10⁴, 5.6 × 10⁴, and 5.1 × 10⁴ kDa, respectively. PSLP-1 and PSLP-2 contained the same type of monosaccharides as PLP but with different molar ratios. The main chain structure of the native polysaccharide was not changed after selenization. PLP, PSLP-1, and PSLP-2 contained the same six types of glycosidic bonds. Bioactivity assays revealed that the two selenized polysaccharides possessed better antioxidant activities than PLP, but their bile acid-binding abilities and inhibitory activities on acetylcholinesterase (AChE) had weakened. In summary, PLP, PSLP-1, and PSLP-2 may be promising Se supplements in functional foods and inhibitors for the treatment of AChE.

Enhancement of functional activity and biosynthesis of exopolysaccharides in Monascus purpureus by genistein treatments

The exopolysaccharides (EPS) produced by the edible medicinal fungus Monascus purpureus (EMP) become the center of growing interest due to their techno-functional properties and their numerous applications in the food industries; however, the low EPS yields limit its application. In this study, the effect of genistein supplementation on the production, rheological and antioxidant properties of EPS by M. purpureus and its biosynthesis mechanism were explored. The results indicated that the addition of genistein (3 g/L) generated a 110% and 59% increase in the maximum mycelial biomass and EPS yield, respectively. The genistein supplementation group (G-EMP) had higher molar percentages of Xyl and Man, and significantly decreased molecule weight and particle size of EPS, which resulted in stronger antioxidant effect and cell growth promotion. Rheological analysis showed that both EMP and G-EMP demonstrated pseudoplastic fluid behavior and G-EMP exhibited strong gel-like elastic behavior (G' > G"). Furthermore, genistein not only facilitated the production of EPS by regulating cell membrane permeability, enhancing cellular respiratory metabolism and monosaccharide precursor synthesis pathways, and enhancing antioxidant enzyme activity to reduce oxidative stress damage, but also affected the composition of the monosaccharides by increasing enzyme activity in the underlying synthesis pathways. These findings expand the application of M. purpureus resources and provide a paradigm for future study of the structural and functional characteristics of EPS.

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Genistein (3 g/L) significantly stimulate yield of biomass and exopolysaccharides (EPS) from M. purpureus.

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The physicochemical and rheological properties of EPS were significantly changed.

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Their antioxidant and cytoprotective effect were compared.

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A possible mechanism for the response of genistein to increase EPS yield is proposed.

Protective Effect of the Polysaccharides from Taraxacum mongolicum Leaf by Modulating the p53 Signaling Pathway in H22 Tumor-Bearing Mice

Dandelion is an edible plant with a variety of bioactive components. This paper mainly reports the antitumor activity of dandelion polysaccharide DLP120 on H22 tumor-bearing mice. DLP120 is an acidic polysaccharide composed of pectin and arabinogalactan. The results indicate that DLP120 markedly inhibited tumor growth in a dose-dependent manner and attenuated and regulated negative effects on organs. In addition, DLP120 not only increased the viability of spleen lymphocytes and natural killer (NK) cells, but also increased the proportion of lymphocyte subsets in peripheral blood. Furthermore, Hematoxylin-Eosin (HE) staining showed that tumor tissues and cells exhibited typical pathology features. Annexin V FITC/PI staining and cell cycle distribution results further confirmed apoptosis and cell cycle arrest in S and G2 phases. Notably, there was a significant accumulation of reactive oxygen species. Western blotting results demonstrated that the expression of p53 was up-regulated in the DLP120 group. Moreover, the pro-apoptotic protein Bax was up-regulated while the inhibitory-apoptotic protein Bcl-2 was down-regulated. In addition, the expression of Fas and FasL, associated with the death receptor pathway, were also up-regulated. Overall, administration of DLP120 in H22 tumor-bearing mice can not only enhance immunity but also directly induce tumor cell apoptosis.

Chemical Modification, Characterization, and Activity Changes of Land Plant Polysaccharides: A Review

Plant polysaccharides are widely found in nature and have a variety of biological activities, including immunomodulatory, antioxidative, and antitumoral. Due to their low toxicity and easy absorption, they are widely used in the health food and pharmaceutical industries. However, low activity hinders the wide application. Chemical modification is an important method to improve plant polysaccharides' physical and chemical properties. Through chemical modification, the antioxidant and immunomodulatory abilities of polysaccharides were significantly improved. Some polysaccharides with poor water solubility also significantly improved their water solubility after modification. Chemical modification of plant polysaccharides has become an important research direction. Research on the modification of plant polysaccharides is currently increasing, but a review of the various modification studies is absent. This paper reviews the research progress of chemical modification (sulfation, phosphorylation, acetylation, selenization, and carboxymethylation modification) of land plant polysaccharides (excluding marine plant polysaccharides and fungi plant polysaccharides) during the period of January 2012-June 2022, including the preparation, characterization, and biological activity of modified polysaccharides. This study will provide a basis for the deep application of land plant polysaccharides in food, nutraceuticals, and pharmaceuticals.

Recent advances in medicinal and edible homologous polysaccharides: Extraction, purification, structure, modification, and biological activities

110 kinds of traditional Chinese medicines can be used for medicine and food from Chinese pharmacopoeia in 2021. With the deepening of research in recent years, medicinal and edible homologous (MEH) traditional Chinese medicines have great development and application prospects in many fields. Polysaccharides are one of the major and representative pharmacologically active macromolecules in traditional Chinese medicines with MEH. Moreover, traditional Chinese medicines with MEH have become the main source of natural polysaccharides with safety, high efficiency, and low side effects. Increasing researches have confirmed that MEH polysaccharides (MEHPs) have multiple biological activities both in vitro and in vivo methods, such as antioxidant, immunomodulatory, anti-tumor, anti-aging, anti-inflammatory, hypoglycemic, hypolipidemic activities, and regulating intestinal flora. Additionally, different raw materials, extraction, purification, and chemical modification methods result in differences in the structure and biological activities of MEHPs. The purpose of the present review is to provide comprehensively and systematically reorganized information in the extraction, purification, structure, modification, biological activities, and potential mechanism of MEHPs to support their therapeutic effects and health functions. New valuable insights and theoretical basis for the future researches and developments regarding MEHPs were proposed in the fields of medicine and food.

Structural characterization of a pectic polysaccharide from laoshan green tea and its inhibitory effects on the production of NO, TNF-α and IL-6

A novel pectic polysaccharide, named GTPS3-1, was isolated and purified from Laoshan green tea polysaccharide (GTPS) through DEAE Sepharose Fast Flow and Sephacryl S-300 columns, its structure was characterized and its anti-inflammatory activity was explored. GTPS3-1, with a molecular weight of 26.05 kDa, was mainly composed of galacturonic acid, galactose, rhamnose and arabinose in a molar ratio of 4.72:2.5:1.68:1 on the basis of monosaccharide composition. Structural analysis results revealed that GTPS3-1 was a highly branched pectin consisting of →3)-Galp-(1→, →2)-Rhap-(1→, →3,5)-Araf-(1→, →3)-Rhap-(1→, GalpA-(1→, →3,4)-Galp-(1→, →4)-GalpA-(1→, →5)-Araf-(1→, →2,4)-Rhap-(1→, Rhap-(1→ and Araf-(1→ according to FT-IR, methylation and NMR analyses. In addition, GTPS3-1 inhibited the production of NO, TNF-α and IL-6 in a dose-dependent manner, which resulted in the amelioration of inflammatory injury in LPS-induced RAW 264.7 cells. These results would provide a theoretical basis for practical application of the novel polysaccharide as an anti-inflammatory adjuvant.

Antibacterial mechanism of polysaccharides from the leaves of Lindera aggregata (Sims) Kosterm. by metabolomics based on HPLC/MS

Lindera aggregata (Sims) Kosterm. is a traditional Chinese herb, which has been proven to have excellent antibacterial activity. In this work, we firstly extracted the polysaccharides from the leaves of Lindera aggregata (Sims) Kosterm. (LLPs), and explored their antibacterial activity and related mechanisms. The experimental results show that LLPs are a good antibacterial agent, which can damage the cell structure of bacteria and lead to the leakage of intracellular lysates. Compared with Escherichia coli (E. coli), LLPs showed better inhibitory activity against Staphylococcus aureus (S. aureus). Furthermore, the administration of LLPs not only led to the upregulation of the levels of fructose-1,6-bisphosphate (F-1,6-P) and citric acid in the glycolysis and tricarboxylic acid cycle pathways in bacteria, but also resulted in the down-regulation of the levels of oxaloacetate (OAA) and 1,3-diphosphoglycerate (1,3-BPG). This study confirmed that LLPs have good antibacterial activity, and broaden the application of the leaves of Lindera aggregata (Sims) Kosterm. in the antibacterial field. It provides ideas for exploring the antibacterial mechanism of active ingredients of Chinese herbal medicine through metabolomics.

Effects of dietary supplement with a Chinese herbal mixture on growth performance, antioxidant capacity, and gut microbiota in weaned pigs

Weaning stress decreases the growth performance of piglets and is one of the main concerns of pig industries. Traditional Chinese herbal medicines have been used to reduce the adverse effects of weaning stress as both nutritional supplements and antibiotic substitutes. This study aimed to evaluate the effects of a Chinese herbal mixture (Kangtaile, which contained Paeonia lactiflora, licorice, dandelion, and tea polyphenols) on the growth performances, immune response, antioxidant capacity, and intestinal microbiota of weaned pigs. A total of 400 weaned pigs [Duroc × (Landrace × Yorkshire)] were randomly allocated into one of four treatments: the CON group, fed with basic diet; the HM1 group, fed with basal diet supplemented with 0.5 g herbal mixture/kg diet; the HM2 group, fed with basal diet supplemented with 1.0 g herbal mixture/kg diet; or the HM3 group, fed with basal diet supplemented with 1.5 g herbal mixture/kg diet. The results revealed that dietary supplementation with the herbal mixture for 28 days improved average daily gain and feed conversion ratio, while decreased the diarrhea rate of weaned pigs. Moreover, dietary supple-mentation with the herbal mixture improved the antioxidant capacity through increasing the activity of catalase (CAT) and the total antioxidant capacity (T-AOC) level, while decreasing the concentration of malondialdehyde (MDA) in the serum. Pigs supplemented with herbal mixture presented an increased serum immunoglobulin (Ig)M level on day 14 compared with control pigs. The herbal mixture altered the composition of intestinal microbiota by influencing the relative abundances of Firmicutes and Bacteroidetes at the phylum level. The relative abundances of the Firmicutes and Bacteroidetes were significantly related to the body weight gain of pigs. In conclusion, supplementation of herbal mixture to the diet improved growth performance, immunity, and antioxidant capacity and modified the composition of intestinal microbiota in weaning pigs. This study provided new insights into the nutritional regulation effects of the herbal mixtures on weaned pigs.

Preparation and structure-activity relationship of highly active black garlic polysaccharides

The aim of this study was to establish a method to improve the biological activity of polysaccharides. Three acid-treated polysaccharides (BGPS-2, BGPS-3 and BGPS-4) were obtained by treating black garlic polysaccharides (BGPS-1) with sulfuric acid at different intensities. The structure was characterized using the sulfuric acid-carbazole assay, IC, HPSEC-MALLS and FT-IR. The biological functions were evaluated using antioxidant and melanin biosynthesis inhibition assays. Compared with BGPS-1, the molecular weight of acid-treated polysaccharides significantly decreased, and the uronic acid content significantly increased. Antioxidant capacity negatively correlated with molecular weight, whereas melanin inhibition activity positively correlated with uronic acid content. BGPS-4 had the highest antioxidant capacity and the lowest molecular weight (1.25 × 10³ Da), 79.41 % lower than that of BGPS-1. BGPS-3 was the strongest inhibitor of melanin formation and had the highest uronic acid content (50.73 %), 238.2 % higher than that of BGPS-1. Molecular weight and uronic acid content were the main structural characteristics that affected the antioxidant and melanin biosynthesis inhibition activities, respectively. BGPS-1, BGPS-2, BGPS-3, and BGPS-4 all had β-linked pyranose, multi-branched, and non-triple helical spiral structures. Therefore, the acid hydrolysis method markedly modified the structural characteristics of black garlic polysaccharides, and increased their antioxidant capacity and melanin biosynthesis inhibition activity.

The anti-obesity effects of a water-soluble glucan from Grifola frondosa via the modulation of chronic inflammation

Polysaccharides from Grifola frondosa (G. frondosa) have anti-obesity and anti-inflammatory activities. In this study, the major type, molecular weight, homogeneity and structure of a polysaccharide purified from G. frondosa (denoted GFPA) were determined. In high-fat diet (HFD)-treated mice, 8 weeks of GFPA administration efficiently decreased body weight and blood glucose concentration and counteracted hyperlipidemia. GFPA efficiently decreased adipocyte size and ameliorated inflammatory infiltration in the three types of white adipose tissue and alleviated steatosis, fat accumulation and inflammatory infiltration in the livers of HFD-fed mice. GFPA also decreased the concentrations of aspartate aminotransferase, alanine aminotransferase and pro-inflammatory factors in the sera and livers of HFD-treated mice. Furthermore, GFPA was found to regulate lipid metabolism via the inhibition of ceramide levels in HFD-treated mice. GFPA exhibited strong anti-obesity effects via the modulation of chronic inflammation through Toll-like receptor 4/nuclear factor kappa-B signaling, which supports the use of GFPA for the treatment of obesity.

Monosaccharide composition and in vivo immuno-stimulatory potential of soluble yam (Dioscorea opposita Thunb.) polysaccharides in response to a covalent Se incorporation

The present study aimed to investigate whether selenylation modification could affect compositional features and in vivo immuno-stimulatory potential of yam polysaccharides. In this study, the soluble yam mucilage polysaccharides (YPS) were prepared and selenylated in the HNO₃-Na₂SeO₃ system, and two selenylated polysaccharide products, namely SeYPS-1 and SeYPS-2 with respective Se contents of 719 and 1585 mg/kg, were thus obtained. GC-MS analysis demonstrated that the compositional features of SeYPS-1 and SeYPS-2 were similar to those of YPS. Meanwhile, the immuno-stimulatory potential of the selenylated products, especially SeYPS-2, in the BALB/c mice model was higher than that of YPS, reflected by the elevated contents of serum immunoglobins and increased percentage of CD4⁺ splenic lymphocytes. It was thus confirmed that the selenylation did not change the composition of monosaccharides but endowed YPS with greater immuno-stimulation in the mice, while the higher extent of selenylation also caused a much enhanced immuno-stimulatory potential of SeYPS-2.

Beneficial Effect of Selenium Doped Carbon Quantum Dots Supplementation on the in vitro Development Competence of Ovine Oocytes

Background

After the synthesis of selenium doped carbon quantum dots (Se/CDs) via a step-by-step hydrothermal synthesis method with diphenyl diselenide (DPDSe) as precursor, the beneficial effects of Se/CDs’ supplementation on the in vitro development competence of ovine oocytes were firstly investigated in this study by the assay of maturation rate, cortical granules’ (CGs) dynamics, mitochondrial activity, reactive oxygen species (ROS) production, epigenetic modification, transcript profile, and embryonic development competence.

Results

The results showed that the Se/CDs’ supplementation during the in vitro maturation (IVM) process not only enhanced the maturation rate, CGs’ dynamics, mitochondrial activity and embryonic developmental competence of ovine oocytes, but remarkably decreased the ROS production level of ovine oocytes. In addition, the expression levels of H3K9me3 and H3K27me3 in the ovine oocytes were significantly up-regulated after the Se/CDs’ supplementation, in consistent with the expression levels of 5mC and 5hmC. Moreover, 2994 up-regulated differentially expressed genes (DEGs) and 846 repressed DEGs were found in the oocytes after the Se/CDs’ supplementation. According to the analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), these DEGs induced by the Se/CDs’ supplementation were positively related to the progesterone mediated oocyte maturation and mitochondrial functions. And these remarkably up-regulated expression levels of DEGs related to oocyte maturation, mitochondrial function, and epigenetic modification induced by the Se/CDs’ supplementation further confirmed the beneficial effect of Se/CDs’ supplementation on the in vitro development competence of ovine oocytes.

Conclusion

The Se/CDs prepared in our study significantly promoted the in vitro development competence of ovine oocytes, benefiting the extended research about the potential applications of Se/CDs in mammalian breeding technologies.

Two Novel Polysaccharides From Clitocybe squamulosa: Their Isolation, Structures, and Bioactivities

The crude polysaccharides from the fruiting bodies of Clitocybe squamulosa (CSFP) were isolated by hot-water extraction. Two novel polysaccharides, CSFP1-β and CSFP2-α, were further purified by DEAE-52 anion exchange and Sephacryl S-400 gel filtration chromatography, and the purities reached 98.44 and 97.83%, respectively. The structural characteristics and bioactivities of CSFP, CSFP1-β, and CSFP2-α were identified by the combination of chemical and instrumental analysis. Results showed that CSFP was formed by the aggregation of honeycomb spherical materials; CSFP1-β and CSFP2-α were interwoven by reticular and fibrous structures, respectively. Purified components of both CSFP1-β and CSFP2-α showed typical infrared absorption peaks of polysaccharides, and contents of nucleic acid and protein decreased significantly. Simultaneously, CSFP with a molecular weight (Mw) of 1.948 × 10⁴ Da were composed mainly of glucose, mannose, galactose, and rhamnose. CSFP1-β was composed mainly of glucose, galactose, and mannose, while CSFP2-α was composed of glucose, and both their Mw distributions were uneven. Compared with CSFP, the antioxidant activities of CSFP1-β and CSFP2-α were significantly improved (p < 0.05), and they both showed good abilities to bind free cholesterol and bile acid salts in vitro. The binding abilities of the two compounds were found to be 68.62 and 64.43%, and 46.66 and 45.05 mg/g, respectively. CSFP, CSFP1-β, and CSFP2-α had good bacteriostatic effects with a linear increasing relationship to increasing concentration. In addition, CSFP promoted the growth of RAW264.7 cells and has potential immunomodulatory, anti-inflammatory, and anti-tumor activities.

Structural characterization and hypolipidemic activity of Gracilaria lemaneiformis polysaccharide and its degradation products

This research aimed to analyze structural characterization and hypolipidemic activity in vitro of G. lemaneiformis polysaccharide (GLP) and its degradation products. The results presented that the content of galacturonic acid declined and glucuronic acid level enhanced, average particle size decreased from 99.9 μm to 25.7 μm, and color brightness of polysaccharide strengthened after degraded by H₂O₂-Vc. There was no significant change in thermal stability of polysaccharide before and after degradation. It was observed in AFM analysis, polysaccharide changed to smaller, delicacy and dispersion after degradation. As seen in FT-IR, H₂O₂-Vc degradation never change the structure of polysaccharide. Polysaccharide and its degradation products showed a significant inhibition effect on pancreatic lipase and cholesterol esterase in a dose-dependent manner, which presented the mixed type of competitive and non-competitive for pancreatic lipase, and non-competitive for cholesterol esterase, respectively. The fluorescence quenching type was static on pancreatic lipase and dynamic on cholesterol esterase.

Preparation, characterization and immunoregulatory activity of derivatives of polysaccharide from Atractylodes lancea (Thunb.) DC

A polysaccharide (ALP-1) extracted from Atractylodes lancea (Thunb.) DC. was carboxymethylated (C-ALP-1), phosphorylated (P-ALP-1) and acetylated (A-ALP-1) to improve its physicochemical properties and bioactivities. The solubility of all derivatives was increased, and the solubility of A-ALP-1 increased to 137.5 mg/mL, which was much higher than the solubility of ALP-1 (15.0 mg/mL). The results of HPSEC-MALLS-RID showed that the molecular weight of polysaccharides was slightly increased after the modification, and the root mean square radius of rotation (Rz) and morphology of polysaccharides in solution were also changed. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results confirmed that the surface morphology of ALP-1 changed dramatically and the crystallinity decreased after structural modification. From thermal analysis results, the T₅₀ of ALP-1, C-ALP-1, P-ALP-1 and A-ALP-1 were 281.34, 292.14, 333.75 and 298.70 °C, which showed that derivatives had stronger thermal stability than ALP-1. The immunomodulatory activity studies displayed that P-ALP-1 showed the best ability to stimulate RAW264.7 macrophages to release NO, and A-ALP-1 showed the best capacity to stimulate TNF-α and IL-6 releasing. These results indicated that chemical modification could enhance the solubility, the thermal stability and immunomodulatory activity of polysaccharides, which is beneficial for the development and utilization of natural polysaccharides.

Structural characterization and anti-osteoporosis activity of two polysaccharides extracted from the rhizome of Curculigo orchioides

Curculigo orchioides is widely used to treat osteoporosis in China. In this study, we identified the active substances in the crude polysaccharide (CO50) from C. orchioides that had anti-osteoporosis activity in vivo. Two polysaccharides, COP50-1 and COP50-4, were purified from CO50. Based on structural analysis, COP50-1 was composed of α-D-Glcp-(1→, β-D-Galp-(1→, →4)-α-D-Glcp-(1→, →3,4)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, →4,6)-β-D-Manp-(1→, whereas COP50-4 was composed of α-L-Araf-(1→, →2)-α-L-Rhap-(1→, β-D-Manp-(1→, α-D-Galp-(1→, →2,4)-α-L-Rhap-(1→, →2)-β-D-Manp-(1→, →4)-α-D-GlcAp-(1→, →3)-α-D-GalAp-(1→, →4,6)-α-D-Galp-(1→, →2,3,6)-β-D-Manp-(1→, →2,3,5)-α-L-Araf-(1→, →2,5)-α-L-Araf-(1→, →4)-α-D-Glcp-(1→ and →3)-α-D-Galp-(1→. Pharmacological assessment revealed that COP50-1 had no obvious osteogenic activity. However, COP50-4 (0.5 μM) significantly enhanced the differentiation and mineralization of osteoblasts in vitro. Moreover, the effect of COP50-4 was greater than that of 17β-estradiol. Therefore, COP50-4 may be an effective component of CO50 that has great potential for development as an alternative drug for the treatment of osteoporosis.

Physicochemical Characteristics and Antidiabetic Properties of the Polysaccharides from Pseudostellaria heterophylla

This study aimed to investigate the Pseudostellaria heterophylla polysaccharides (PF40) physicochemical and antidiabetic characteristics. The ultraviolet–visible (UV) spectra, Fourier transform infrared radiation (FT-IR) spectra, nuclear magnetic resonance (NMR) spectra, zeta potential, surface characteristics, and conformational and thermal stability properties of PF40 were characterized. X-ray diffraction (XRD) and scanning electron microscopy (SEM), combined with Congo red test, revealed that PF40 powder has mainly existed in amorphous form with triple-helix conformation. The single-molecular structure of PF40 exhibited a multi-branched structure extending from the center to the periphery by scanning probe microscopy (SPM) scanning. The monosaccharide residue of PF40 was an α-pyranoid ring and exhibits good stability below 168 °C. Experimental studies on antidiabetic characteristics found that PF40 could significantly improve STZ-induced intestinal mucosal damage and reduce the apoptosis of villus epithelial cells. PF40 combined with metformin could significantly improve the symptoms of insulin resistance in type 2 diabetes mellitus (T2DM) rats, the molecular mechanism might be through inhibiting the expression of RORγ protein and increasing Foxp3 protein in the jejunum of T2DM rats, and then restoring the STZ-induced imbalance of T helper 17(Th17)/ regulatory T cells (Treg) cells, thereby maintaining intestinal immune homeostasis. Results identified in this study provided important information regarding the structure and antidiabetic characteristics of Pseudostellaria heterophylla polysaccharides, which can contribute to the development of Pseudostellaria heterophylla polysaccharides for industrial purposes in the future.

The Protective Effects of Three Polysaccharides From Abrus cantoniensis Against Cyclophosphamide-Induced Immunosuppression and Oxidative Damage

This study was designed to systematically elucidate the immunomodulatory and antioxidant effects of three polysaccharide fractions (ACP₆₀, ACP₈₀, and ACP_t2) from Abrus cantoniensis on cyclophosphamide (CTX)-induced immunosuppressive mice. The experimental mice were divided into 12 groups, then modeled and administrated with different doses of three polysaccharides (50, 150, 300 mg/kg/day) by gavage. The results showed that ACP could markedly recover the CTX-induced decline in immune organ and hemocytes indexes and promote proliferation of splenocytes, earlap swelling rate, secretion of cytokines (TNF-α, IFN-γ, IL-1β, IL-6), and immunoglobulin (Ig-M and Ig-G). Additionally, ACP improved the enzymatic activities of T-SOD and GSH-PX greatly, while the level of MDA was significantly decreased in the liver. In particular, ACP_t2 had higher immunomodulatory and antioxidant activities than ACP₆₀ and ACP₈₀. Based on the present findings, ACP could be utilized as an efficacious candidate for immunomodulators and antioxidants, which provide a new application prospect in the food and pharmaceutical industries.

Structural characterization of a polysaccharide from Trametes sanguinea Lloyd with immune-enhancing activity via activation of TLR4

A bioactive polysaccharide (TS2-2A) with a molecular weight of 15 kDa was isolated from Trametes sanguinea Lloyd, a medicinal food homologous fungus, by water extraction-alcohol precipitation and chromatographic separation. NMR analysis of polysaccharide and MS/MS analysis of its oligosaccharide indicated that TS2-2A featured a novel straight chain with a backbone of 1,3-α-d-glucopyranose and 1,4-β-d-glucopyranose at a molar ratio of 1:4. Moreover, TS2-2A, recognized by Toll-like receptor 4 (TLR4), stimulated RAW 264.7 macrophages to release related cytokines and contributed to immune-enhancing effects. Briefly, with remarkable immune-enhancing activity and noncytotoxicity, TS2-2A was proposed to be a potential immune enhancer for supplementing drugs or functional foods.

Synthesis of Hydroxypropyltrimethyl Ammonium Chitosan Derivatives Bearing Thioctate and the Potential for Antioxidant Application

Hydroxypropyltrimethyl ammonium chloride chitosan (HACC) is one of the most important water-soluble chitosan derivatives; its derivatives have gained growing attention due to their potential biomedical applications. Here, hydroxypropyltrimethyl ammonium chitosan derivatives bearing thioctate (HACTs), with different degrees of substitution of thioctate, were prepared using HACC and α-lipoic acid as the reaction precursors, using an ion exchange method. The structural characteristics of the synthesized derivatives were confirmed by FTIR, ¹H NMR, and ¹³C NMR spectroscopy. In addition, their antioxidant behaviors were also investigated in vitro by the assays of reducing power, and scavenging activities against hydroxyl radicals and DPPH radicals. The antioxidant assay indicated that HACTs displayed strong antioxidant activity compared with HACC, especially in terms of reducing power. Besides, the antioxidant activities of the prepared products were further enhanced with the increase in the test concentration and the degrees of substitution of thioctate. At the maximum test concentration of 1.60 mg/mL, the absorbance value at 700 nm of HACTs, under the test conditions, was 4.346 ± 0.296, while the absorbance value of HACC was 0.041 ± 0.007. The aforementioned results support the use of HACTs as antioxidant biomaterials in food and the biomedical field.

Material Basis Elucidation and Quantification of Dandelion through Spectrum-Effect Relationship Study between UHPLC Fingerprint and Antioxidant Activity via Multivariate Statistical Analysis

The excessive expression of reactive oxygen species is closely connected to many diseases. Considerable studies have demonstrated dandelion as well as its ingredients exhibited antioxidant activity. However, specific material basis reflecting the antioxidant activity has not been comprehensively investigated. In this study, a spectrum–effect relationship study on dandelion between fingerprinting and antioxidant activity was analyzed in detail, while a UHPLC quantification method developed and completely validated for simultaneous determination of active ingredients in dandelion. With the establishment of dandelion fingerprints of different regions, 24 common peaks were characterized. The classic FRAP method and ABTS methods were then used to detect their antioxidant activity. Partial least squares regression analysis, bivariate correlation analysis and grey correlation method were used to accomplish the spectrum–effect relationship. Eventually, the ingredients with antioxidant activity which could be considered as candidate quality markers of dandelion were discovered through spectrum–effect relationship analysis. The six compounds including caftaric acid, chlorogenic acid, caffeic acid, chicoric acid, isochlorogenic acid A, and isochlorogenic acid C were quantitatively determined. The developed UHPLC assay method was accurate, precise, and reliable. The study has elucidated the antioxidant material basis of dandelion and provided a scientific basis for the quality control of dandelion.

Effects of ultra-high pressure treatment on structure and bioactivity of polysaccharides from large leaf yellow tea

In this study, the changes of structure and bioactivity of polysaccharides from large leaf yellow tea (LYTP) were investigated under ultra-high pressure (UHP). Native yellow tea polysaccharide were treatmented with ultra-high pressure (200, 400 and 600 MPa) for 5 min to yield yellow tea polysaccharide including 200 MPa-LYTP, 400 MPa-LYTP and 600 MPa-LYTP. It was found that the monosaccharide composition of LYTP changed significantly after the ultra-high pressure treatment. The molecular weight (Mw) of 200 MPa-LYTP (from 563.6 to 11.7 kDa), 400 MPa-LYTP (from 372.2 to 11.8 kDa) and 600 MPa-LYTP (from 344 to 11.6 kDa) sharply decreased upon ultra-high pressure treatment compared with LYTP (771.5 kDa), coincidentally particle size was also significantly reduced for 200 MPa-LYTP (23.2 %), 400 MPa-LYTP (40.2 %) and 600 MPa-LYTP (25.9 %). The results of the scanning electron microscope showed that ultra-high pressure also changed the surface and spatial morphology of LYTP. LYTP after ultra-high pressure treatment (UHP-LYTP) could further ameliorate alcohol-induced liver injury in mice. In addition, UHP treatment can more efficiently remove protein than the Sevages method. With the gradual removal of protein, its hepatoprotective effect increased. These findings demonstrated that UHP treatment could change the primary structure and spatial structure of LYTP, increase the content of acidic polysaccharides, and improve its bioactivity.

In vitro digestion and fermentation by human fecal microbiota of polysaccharides from Clitocybe squamulose

The present study aimed to evaluate the effects of in vitro simulated saliva-gastrointestinal digestion and fecal fermentation behavior on the chemical composition, structure and bioactivity of polysaccharides from Clitocybe squamulosa (CSFP). Results showed that gastric digestion significantly changed the chemical composition and structural properties of CSFP, such as total uronic acid, reducing sugar, molecular weight, rheological properties, particle size, and microscopic morphology. In particular, the molecular weight decreased from 19,480 Da to 10,945 Da, while the reducing-sugar content increased from 0.149 mg/mL to 0.293 mg/mL. Gastric digestion also affected the biological activity of CSFP. Although after gastric digestion, CSFP retained its vigorous antioxidant activity, ability to inhibit α-amylase activity, and the binding ability to bile acid, fat, and free cholesterol in vitro. However, there was an apparent weakening trend. After in vitro fermentation of gut microbiota, the content of total sugar was significantly decreased from 11.6 mg/mL to 2.4 mg/mL, and the pH value in the fecal culture significantly decreased to 5.20, indicating that CSFP could be broken down and utilized by gut microbiota. Compared to the blank, the concentrations of total short-chain fatty acids (SCFAs) including acetic, propionic and n-butyric significantly increased. Simultaneously, CSFP could remarkably reduce the proportions of Firmicutes and Bacteroides (F/B) and promote the growth of some beneficial intestinal microbiota. Therefore, CSFP can potentially be a new functional food as prebiotics to promote human gut health.