A heteropolysaccharide purified from leaves of Ilex latifolia displaying immunomodulatory activity in vitro and in vivo

Structural characteristics, immune-activating mechanisms in vitro, and immunomodulatory effects in vivo of the exopolysaccharide EPS53 from Streptococcus thermophilus XJ53

Our previous investigations have successfully identified the repeating structural units of EPS53, an exopolysaccharide derived from Streptococcus thermophilus XJ53 fermented milk, and substantiated its potential immunomodulatory properties. The present study further elucidated the structural characteristics of EPS53 and investigated the underlying mechanisms governing its in vitro immunoreactivity as well as its in vivo immunoreactivity. The results obtained from multi-detector high performance gel filtration chromatography revealed that EPS53 adopted a rigid rod conformation in aqueous solution, with the weight-average molecular weight of 1464 kDa, the number-average molecular weight of 694 kDa, and the polydispersity index of 2.11. Congo red experiment confirmed the absence of a triple helix conformation. Scanning electron microscopy showed that EPS53 displayed a three-dimensional fibrous structure covered with flakes. The in vitro findings indicated that EPS53 enhanced phagocytosis ability, reactive oxygen species (ROS) production, and cytokine levels of macrophages via the TLR4-mediated NF-κB/MAPK signaling pathways as confirmed by immunofluorescence staining experiments, inhibition blocking experiments, and Western blot assay. Additionally, the in vivo experiments demonstrated that EPS53 significantly increased macrophage and neutrophil number while enhancing NO and ROS levels in zebrafish larvae; thus, providing further evidence for the immunomodulatory efficacy of EPS53.

The Isolation, Structural Characterization and Anti-Inflammatory Potentials of Neutral Polysaccharides from the Roots of Isatis indigotica Fort

Polysaccharides have been assessed as a potential natural active component in Chinese herbal medicine with anti-inflammatory properties. However, the complex and indefinite structures of polysaccharides limit their applications. This study explains the structures and anti-inflammatory potentials of three neutral polysaccharides, RIP-A1 (Mw 1.8 × 104 Da), RIP-B1 (Mw 7.4 × 104 Da) and RIP-B2 (Mw 9.3 × 104 Da), which were isolated from the roots of Isatis indigotica Fort. with sequenced ultrafiltration membrane columns, DEAE-52 and Sephadex G-100. The planar structures and microstructures of RIP-A1, RIP-B1 and RIP-B2 were further determined by HPGPC, GC-MS, methylation analysis, FT-IR, SEM and AFM, in which the structure of RIP-A1 was elucidated in detail using 1D/2D NMR. The Raw 264.7 cells were used for the anti-inflammatory activity in vitro. The results showed that RIP-A1, RIP-B1 and RIP-B2 are all neutral polysaccharides, with RIP-A1 having the smallest Mw and the simplest monosaccharide composition of the three. RIP-A1 is mainly composed of Ara and Gal, except for a small quantity of Rha. Its main structure is covered with glycosidic linkages of T-α-Araf, 1,2-α-Rhap, 1,5-α-Araf, T-β-Galp, 1,2,4-α-Rhap, 1,3,5-α-Araf and 1,6-β-Galp with 0.33:0.12:1.02:0.09:0.45:11.41:10.23. RIP-A1 significantly inhibited pro-inflammatory cytokines (NO, TNF-α, IL-6 and IL-1β) and increased anti-inflammatory cytokines (IL-4) in LPS-stimulated RAW 264.7 cells. Moreover, RIP-A1 could significantly inhibit the mRNA expression of TNF-α, IL-6 and L-1β. It could also activate IKK, p65 and IκBα (the components of the NF-κB signaling pathway). In conclusion, the above results show the structural characterization and anti-inflammatory potentials of RIP-A1 as an effective natural anti-inflammatory drug.

A glucuronogalactomannan isolated from Tetrastigma hemsleyanum Diels et Gilg: Structure and immunomodulatory activity

A novel acidic glucuronogalactomannan (STHP-5) was isolated from the aboveground part of Tetrastigma hemsleyanum Diels et Gilg with a molecular weight of 3.225 × 105 kDa. Analysis of chain conformation showed STHP-5 was approximately a random coil chain. STHP-5 was composed mainly of galactose, mannose, and glucuronic acid. Linkages of glycosides were measured via methylation analysis and verified by NMR. In vitro, STHP-5 induced the production of nitric oxide (NO) and secretion of IL-6, MCP-1, and TNF-α in RAW264.7 cells, indicating STHP-5 had stimulatory activity on macrophages. STHP-5 was proven to function as a TLR4 agonist by inducing the secretion of secreted embryonic alkaline phosphatase (SEAP) in HEK-Blue™-hTLR4 cells. The TLR4 activation capacity was quantitatively measured via EC50, and it showed purified polysaccharides had stronger effects (lower EC50) on activating TLR4 compared with crude polysaccharides. In conclusion, our findings suggest STHP-5 may be a novel immunomodulator.

An antitumor arabinan from Glehnia littoralis activates immunity and inhibits angiogenesis

Glehnia littoralis is an edible plant with significant medicinal value. To further elucidate the potential functional components for developing antitumor agents or functional foods, the polysaccharides in this plant were investigated, and a homogeneous polysaccharide, GLP90-2, was obtained through extraction and ethanol precipitation. By employing methylation, GC-MS, FT-IR, and NMR analysis, GLP90-2 was identified as an arabinan having a molecular weight of 7.76 × 103 g/mol and consisting of three types of residues: α-l-Araf-(1→, →5)-α-l-Araf-(1→, and →3,5)-α-l-Araf-(1→. The subsequent functional analysis revealed that GLP90-2 suppressed tumor development and metastasis in a zebrafish model. Mechanistic studies have shown that GLP90-2 promoted the maturation of DC2.4 cells and macrophages and enhanced the expression of immune-related cytokines, which may be attributed to the interaction between GLP90-2 and TLR-4. Additionally, GLP90-2 exhibited a strong interaction with PD-1, contributing to the activation of immunity. Furthermore, GLP90-2 suppressed angiogenesis in the transgenic zebrafish model, and this impact may be ascribed to the modulation of the VEGF/VEGFR-2 signaling pathway. All the results indicate that GLP90-2 demonstrates a strong tumor immunotherapy effect in vivo and has high potential for development.

Screening and characterization of an anti-inflammatory pectic polysaccharide from Cucurbita moschata Duch

Pectin polysaccharides have demonstrated diverse biological activities, however, the inflammatory potential of pectin polysaccharides extracted from Cucurbita moschata Duch remains unexplored. This study aims to extract, characterize and evaluate the effects of pumpkin pectin polysaccharide on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 cells and dextran sulfate sodium (DSS)-induced colitis in mice, along with its underlying mechanism of action. Initially, we extracted three fractions of pectin polysaccharides from pumpkin and screened them for anti-inflammatory activity in LPS-induced macrophages, identifying CMDP-3a as the most potent anti-inflammatory fraction. Subsequently, CMDP-3a underwent comprehensive characterization through chromatography and spectroscopic analysis, revealing CMDP-3a as an RG-I-HG type pectin polysaccharide with →4)-α-D-GalpA-(1 → and →4)-α-D-GalpA-(1 → 2,4)-α-L-Rhap-(1 → as the main chain. Further, in the LPS-induced RAW264.7 cells model, treatment with CMDP-3a significantly down-regulated the mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) by inhibiting the MAPK and NF-κB signaling pathways. Finally, in a mouse colitis model, CMDP-3a administration obviously inhibited DSS-induced pathological alterations and reduced inflammatory cytokine expressions in the colonic tissues by down-regulating the TLR4/NF-κB and MAPK pathways. These findings provide a molecular basis for the potential application of CMDP-3a in reducing inflammatory responses.

Immunomodulation of nutritional formula containing epigallocatechin-3-gallate, ginseng extract, and polydextrose on inflammation and macrophage polarization

Single nutrient likes polyphenol or dietary fiber have been exhaustively investigated to validate their positive intervention in health or disease. Meanwhile, the common interaction of inner systems with the nutrient complex has not been well elucidated, which raises the scientific issue of the modulatory effect of the nutrient complex on immunity. The representative prebiotics of epigallocatechin-3-gallate (EGCG), ginseng extract, and polydextrose (PDX) were selected on behalf of the classification of polyphenol, flavone or polysaccharides, and dietary fiber to generally cover the daily food intake in this study to explore their intervention in inflammation and macrophage polarization. The intervention of selected nutrients on inflammation and macrophage polarization has been evaluated against macrophages to unveil their comprehensive effects. The synergistic effect of selected nutrients was demonstrated by inhibiting M1 macrophage polarization and the promotion of M2 macrophage polarization. Then, the nutrient formula was set up to verify the intervention effect, and the results revealed the significant inhibition of cell inflammation and the effect on cell proliferation through promoting the cell cycle in the G2 phase. The nutrient complex could inhibit M1 macrophage polarization to inhibit M1-mediated inflammation and promote M2 macrophages for anti-inflammatory effect and enhance cell phagocytosis. Moreover, the varied intervention effects of the nutrient complex with different formulas could be summarized. In general, the formula containing EGCG, ginseng extract, and PDX was demonstrated to possess an enhanced immunomodulatory effect on cell inflammation and macrophage polarization, which could potentially inspire the investigation of complex nutrients in health and diseases.

Structural Characterization and Anticomplement Activity of an Acidic Heteropolysaccharide from Lysimachia christinae Hance

A novel acidic heteropolysaccharide (LCP-90-1) was isolated and purified from a traditional "heat-clearing" Chinese medicine, Lysimachia christinae Hance. LCP-90-1 (Mw, 20.65 kDa) was composed of Man, Rha, GlcA, Glc, Gal, and Ara, with relative molar ratios of 1.00: 3.00: 11.62: 1.31: 1.64: 5.24. The backbone consisted of 1,4-α-D-GlcpA, 1,4-α-D-Glcp, 1,4-β-L-Rhap, and 1,3,5-α-L-Araf, with three branches of β-D-Galp-(1 → 4)-β-L-Rhap-(1→, α-L-Araf-(1→ and α-D-Manp-(1→ attached to the C-5 position of 1,3,5-α-L-Araf. LCP-90-1 exhibited potent anticomplement activity (CH50: 135.01 ± 0.68 µg/mL) in vitro, which was significantly enhanced with increased glucuronic acid (GlcA) content in its degradation production (LCP-90-1-A, CH50: 28.26 ± 0.39 µg/mL). However, both LCP-90-1 and LCP90-1-A were inactivated after reduction or complete acid hydrolysis. These observations indicated the important role of GlcA in LCP-90-1 and associated derivatives with respect to anticomplement activity. Similarly, compared with LCP-90-1, the antioxidant activity of LCP-90-1-A was also enhanced. Thus, polysaccharides with a high content of GlcA might be important and effective substances of L. christinae.

A zinc-modified Anemarrhena asphodeloides polysaccharide complex enhances immune activity via the NF-κB and MAPK signaling pathways

Anemarrhena asphodeloides polysaccharide (AAP70-1) was reported to have immunomodulatory effects in our previous report. To further improve the immunomodulatory effects of AAP70-1, an A. asphodeloides polysaccharide-zinc complex (AAP-Zn) was synthesized using a ZnCl2 modification method, and the potential mechanisms by which AAP-Zn activates macrophages were investigated. The results showed that the structural features of AAP-Zn were similar to those of AAP70-1 with a Zn content of 0.2 %, confirming that Zn mainly interacted with AAP70-1 by forming ZnO coordination bonds and Zn…OH bonds. In addition, the administration of AAP70-1 and AAP-Zn effectively improved the immunomodulatory effects by enhancing phagocytosis and upregulating the mRNA expression of cytokines (TNF-α, IL-6, IL-1β, and IL-18), as well as increasing the production levels of nitric oxide (NO) and reactive oxygen species (ROS) in zebrafish embryos. The intracellular mechanism by which AAP-Zn activates macrophages was found to involve activation of the NF-κB and MAPK signaling pathways. Our findings suggested that AAP-Zn may be a potential immunopotentiator in the field of biomedicine or functional foods.

In Vitro and In Vivo Effects of Ulvan Polysaccharides from Ulva rigida

One of the main bioactive compounds of interest from the Ulva species is the sulfated polysaccharide ulvan, which has recently attracted attention for its anticancer properties. This study investigated the cytotoxic activity of ulvan polysaccharides obtained from Ulva rigida in the following scenarios: (i) in vitro against healthy and carcinogenic cell lines (1064sk (human fibroblasts), HACAT (immortalized human keratinocytes), U-937 (a human leukemia cell line), G-361 (a human malignant melanoma), and HCT-116 (a colon cancer cell line)) and (ii) in vivo against zebrafish embryos. Ulvan exhibited cytotoxic effects on the three human cancer cell lines tested. However, only HCT-116 demonstrated sufficient sensitivity to this ulvan to make it relevant as a potential anticancer treatment, presenting an LC₅₀ of 0.1 mg mL^-1. The in vivo assay on the zebrafish embryos showed a linear relationship between the polysaccharide concentration and growth retardation at 7.8 hpf mL mg^-1, with an LC₅₀ of about 5.2 mg mL^-1 at 48 hpf. At concentrations near the LC₅₀, toxic effects, such as pericardial edema or chorion lysis, could be found in the experimental larvae. Our in vitro study supports the potential use of polysaccharides extracted from U. rigida as candidates for treating human colon cancer. However, the in vivo assay on zebrafish indicated that the potential use of ulvan as a promising, safe compound should be limited to specific concentrations below 0.001 mg mL^-1 since it revealed side effects on the embryonic growth rate and osmolar balance.

Preparation and anti-tumor activity of selenium nanoparticles based on a polysaccharide from Paeonia lactiflora

The combination of selenium and polysaccharides is one of the significant ways to ameliorate the anti-cancer effects of polysaccharides. PLP50-1, a homogeneous polysaccharide purified from the aqueous extract of Paeonia lactiflora, had a molecular weight of 1.52 × 10⁴ Da and consisted of α-D-Glcp-(1→, →4)-α-D-Glcp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and →6)-β-D-Fruf-(2→. PLP50-1 showed weak anti-tumor effects against A549 cells. To ameliorate the activity of PLP50-1, the complex nanoparticles combining P. lactiflora polysaccharide with selenium were constructed successfully. Structural properties of the polysaccharide-based selenium nanoparticles (PLP-SeNPs) were clarified using various means. The results displayed that a kind of monodisperse spherical nanoparticles containing high selenium content (39.1 %) with controllable size was constructed and showed satisfactory stability. The cellular anti-tumor assay indicated that PLP-SeNPs had stronger antiproliferative activity against A549 cells than PLP50-1. Additionally, the zebrafish experiments displayed that PLP-SeNPs inhibited the proliferation and migration of A549 cells significantly and blocked the angiogenesis.

An Acidic Heteropolysaccharide Isolated from Pueraria lobata and Its Bioactivities

A novel water-soluble acidic heteropolysaccharide, called PPL-1, was purified from Pueraria lobata. PPL-1 had an average molecular weight of 35 Kad, and it was composed of glucose, arabinose, galactose and galacturonic acid (6.3:0.8:0.8:2.1). In accordance with methylation and nuclear magnetic resonance analyses, PPL-1 primarily consisted of (1→2)-linked α-Araf, (1→4)-linked α-Glcp, (1→)-linked β-Glcp, (1→6)-linked α-Glcp, (1→3,6)-linked α-Galp, (1→)-linked β-GalpA and (1→4)-linked α-GalpA. In terms of bioactivities, PPL-1 exhibited remarkable scavenging ability towards DPPH (1,1-Diphenyl-2-picrylhydrazyl) radicals and moderate activity by enhancing the proliferation rate of RAW 264.7 cells by approximately 30% along with the secretion of NO. This work demonstrates that PPL-1 can be a potential source of immunoenhancers and antioxidants.

Secotrijugins A-D, four highly oxidized and rearranged limonoids from Trichilia sinensis and their anti-inflammatory activity

Four undescribed highly oxidized and rearranged limonoids, secotrijugins A-D, were purified from the leaves and twigs of Trichilia sinensis. Within them, secotrijugin A was characterized as a rare 30-nortrijugin-type limonoid with an unusual cleavage of 1,14-ether bond, secotrijugins B and C represented new examples with the cleavage of δ-lactone ring D, and secotrijugin D was a rare trijugin-type limonoid with an unusual 2,6-oxygen bridge. The structures of limonoids were characterized by means of spectroscopic analysis and ECD calculations. The cellular screening revealed that secotrijugin B was the most active against LPS-stimulated NO production in BV-2 cells, which played an anti-inflammatory role by downregulating COX-2 and iNOS protein expression. The further in vivo experiments confirmed that secotrijugin B had strong in vivo anti-inflammatory effect via suppressing NO and ROS generation.

Effect of propolis on Th2 and Th17 cells: interplay with EtxB- and LPS-treated dendritic cells

Dendritic cells (DCs) are antigen-presenting cells that drive the differentiation of T CD4+ cells into different profiles according to the nature of the antigen or immunomodulator. Propolis is a resinous product made by bees that has numerous pharmacological properties, including an immunomodulatory action. To assess whether propolis can modulate the activation of CD4+ T cells by stimulating DCs with heat-labile enterotoxin B subunit (EtxB) or lipopolysaccharide (LPS), we aimed to elucidate the mechanisms affected by propolis in the differential activation of T lymphocytes. Cell viability, lymphocyte proliferation, gene expression (GATA-3 and RORc), and cytokine production (interleukin (IL)-4 and IL-17A) were analyzed. Propolis, EtxB, and LPS induced a higher lymphoproliferation compared with the control. Propolis induced GATA-3 expression and, in combination with EtxB, maintained the baseline levels. Propolis alone or in combination with LPS inhibited RORc expression. EtxB alone and in combination with propolis increased IL-4 production. Propolis in combination with LPS prevented LPS-induced IL-17A production. These results opened perspectives for the study of biological events that may be favored by propolis by promoting Th2 activation or helping in the treatment of inflammatory conditions mediated by Th17 cells.

Structure, selenization modification, and antitumor activity of a glucomannan from Platycodon grandiflorum

Platycodon grandiflorum is consumed popularly as a nutritional and healthy plant in East Asia, which has multiple medicinal functions. As an exploration to elucidate the beneficial ingredients, an acetylated glucomannan (PGP40-1) was purified from P. grandiflorum. Structural analysis showed that PGP40-1 was composed of →4)-β-Manp-(1→, →4)-β-Glcp-(1→, →6)-β-Glcp-(1→, and terminal α-Glcp-(1→. PGP40-1 was found to possess weak antitumor activity in vitro, which was thus modified to afford a selenized polysaccharide (Se-PGP40-1) by the HNO₃/Na₂SeO₃ method. Se-PGP40-1 showed significant antitumor activity in cell and zebrafish models, which could inhibit tumor proliferation and migration by inducing cell apoptosis and blocking angiogenesis. The research not only clarifies the ingredients of P. grandiflorum with high economical value, but also affords a potential antitumor agent originating from the plant polysaccharide.

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.

Preparation and structural properties of selenium modified heteropolysaccharide from the fruits of Akebia quinata and in vitro and in vivo antitumor activity

Cancer is a complex disease, and blocking tumor angiogenesis has become one of the most promising approaches in cancer therapy. Here, an exopoly heteropolysaccharide (AQP70-2B) was firstly isolated from Akebia quinata. Monosaccharide composition indicated that the AQP70-2B was composed of rhamnose, glucose, galactose, and arabinose. The backbone of AQP70-2B consisted of →1)-l-Araf, →3)-l-Araf-(1→, →5)-l-Araf-(1→, →3,5)-l-Araf-(1→, →2,5)-l-Araf-(1→, →4)-d-Glcp-(1→, →6)-d-Galp-(1→, and →1)-d-Rhap residues. Based on the close relationship between selenium and anti-tumor activity, AQP70-2B was modified with selenium to obtain selenized polysaccharide Se-AQP70-2B. Then, a series of methods for analysis and characterization, especially scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS), indicated that Se-AQP70-2B was successfully synthesized. Furthermore, zebrafish xenografts and anti-angiogenesis experiments indicated that selenization could improve the antitumor activity by inhibiting tumor cell proliferation and migration and blocking angiogenesis.

Structural characterization of polysaccharide purified from Amanita caesarea and its pharmacological basis for application in Alzheimer's disease: endoplasmic reticulum stress

Alzheimer's disease (AD) leads to progressive declines in memory and learning. This disease may arise from endoplasmic reticulum stress due to protein misfolding, which promotes inflammatory pathway activation and induces neuronal cell apoptosis. Polysaccharide is one of the main active components of the mushroom Amanita caesarea (A. caesarea) and has been proven to act as an antioxidant, immune regulatory and anti-inflammatory agent with neurodevelopmental effects. In this study, polysaccharide isolated from A. caesarea (ACPS2) was subjected to analysis to determine the main components, homogeneity and molecular weight and characterize the structure. Furthermore, APP/PS1 mice were orally treated with ACPS2 for 6 weeks. Structural characterization of ACPS2 revealed a mass average molar mass of 16.6 kDa and a structure containing a main chain and branching. In vivo, treatment with ACPS2 for 6 weeks significantly improved cognition and anxious behavior in APP/PS1 mice using Morris water maze and open-field test. Alleviation of brain injury, amyloid-β deposition and tau hyperphosphorylation were observed in ACPS2-treated AD mice. No changes in other tissues were observed. ACPS2 appeared to alleviate inflammation in vivo, as determined by decreases in the serum concentrations of tumor necrosis factor-α and interleukin-1β relative to those in non-treated mice. ACPS2 improved cholinergic system function and stabilized oxidative stress in APP/PS1 mice. Proteomics and bioinformatics analyses showed that the therapeutic effect of ACPS2 is achieved through regulation of oxidative stress-mediated endoplasmic reticulum stress. Furthermore, ACPS2 exerted anti-AD effects by regulating nuclear factor-E2-related factor 2 (Nrf2) signaling, thereby inhibiting endoplasmic reticulum stress and nuclear factor-kappa B (NF-κB) activation.

Structural elucidation and anti-diabetic osteoporotic activity of an arabinogalactan from Phellodendron chinense Schneid

Phellodendron chinense Schneid. was widely used as a medicinal herb for the treatment of diabetic osteoporosis in China. In this study, an arabinogalactan, named as PPCP-1, was isolated from the bark of Phellodendron chinense Schneid., and purified by DEAE-cellulose DE52 and Sephacryl S-200 HR column chromatography. The structure of PPCP-1 was characterized as a repeating unit consisting of →3)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→, →5)-α-l-Araf-(1→, →4)-α-d-Glcp-(1→, →3)-α-d-Glcp-(1→, →4)-α-d-Manp-(1→ with branches of →5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→ and terminal α-l-Araf. Pharmacologically, the oral administration of PPCP-1 preserved osteoporosis associated with hyperglycemia by inhibiting α-glucosidase activity, improving glucose tolerance, decreasing the accumulation of advanced glycation end products (AGEs), as well as down-regulating the expression of receptor for AGEs in tibias of streptozotocin-induced diabetic rats. Collectively, the present study suggested that the arabinogalactan PPCP-1 from Phellodendron chinense Schneid. might potentially be used as functional foods for bone health and/or developed for drug discovery for alleviating diabetic osteoporosis.

Structure characteristics and immunomodulatory activities of a polysaccharide RGRP-1b from radix ginseng Rubra

The present study was undertaken to explore the structure characteristics, immune regulation, and anti-cancer abilities of polysaccharides in radix ginseng Rubra (RGR). For this purpose, RGR polysaccharides (RGRP) were purified through DEAE and S-300 chromatography. Monosaccharide composition, methylation, and GC-MS analyses, as well as field emission scanning electron microscope (FESEM), atomic force microscope (AFM), Fourier-transformed infrared resonance (FT-IR), and nuclear magnetic resonance (NMR) spectra, were used to establish the structure of RGRP-1b. Our results revealed that RGRP-1a and RGRP-1b possess different molecular weights (21.3 kDa and 10.2 kDa, respectively). RGRP-1a was found to be composed of glucose, while RGRP-1b was composed of glucose, galactose, and arabinose. The main chain structure of RGRP-1b was composed of 1,4-α-Glcp, with a 1,4,6-α-Glcp branch unit. Its side chains were branched at the O-4 position of 1,4,6-α-Glcp, namely 1)-β-Galp-(4 → 1)-α-Araf-(5 → α-Araf and 1)-β-Galp-(6 → α-Glcp. The changes in the nitric oxide (NO) levels and cytotoxicity revealed that macrophages probably get activated by RGRP-1b. The expressions of IL-6, IL-12, and TNF-α were found to be upregulated after treatment with RGRP-1b. RGRP-1b thus possesses the potential to arrest the growth of Huh7 through immunoregulation. Our cumulative findings indicate that RGRP-1b obtained from radix ginseng Rubra can function as a strong immune modulator.

Promotion Effect of EGCG on the Raised Expression of IL-23 through the Signaling of STAT3-BATF2-c-JUN/ATF2

Tea polyphenol of epigallocatechin-3-gallate (EGCG) has been verified to possess multiple biological activities. Interleukin-23 (IL-23) is a heterodimeric cytokine consisting of two subunits of IL-23p19 and IL-12p40, with the functionality in regulating the production of cytokines under physiological or pathological conditions. By serendipity, the raised expression of IL-23 was observed after treating cells with EGCG, whereas the detailed mechanism remains poorly understood. This study was proposed to investigate the signaling related to EGCG-induced IL-23. The raised expression of IL-23 was confirmed primarily by intraperitoneally injecting with different concentrations of EGCG (0, 20, 50, 80 mg/kg) into BALB/c mice, and the raised expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Results from enzyme-linked immunosorbent assay (ELISA) revealed the increase of IL-23 in serum from 116.09 to 153.90 pg/mL after treating with EGCG. The same results were also observed in RAW264.7 and peritoneal macrophages after treating with EGCG (0, 1, 5, 10, 25 μM) with the increased tendency of IL-23 in cultural medium (7.98 to 25.38 pg/mL for RAW264.7; 3.64 to 260.93 pg/mL for peritoneal macrophages). After preliminary exploration of the signaling related to the increased IL-23, the classical signaling pathways and key transcription factors, such as nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase (MAPK) signaling pathways, and interferon regulatory factor 5 (IRF5), were demonstrated with no relevant contribution. A further study revealed the involvement of the key transcription factor of BATF2, which could antagonistically modulate the transcription and translation of IL-23. The signaling of STAT3-BATF2-c-JUN/ATF2-IL-23 has been further verified in RAW264.7 macrophages using the STAT3 inhibitor of AG490 and the activator of Colivelin TFA. The results indicated that EGCG inhibits the phosphorylation of STAT3 to facilitate the decreased level of BATF2, which contributed to the increased level of IL-23 by the enhancing heterodimerization of c-JUN and ATF2.

Structural characteristics and in vitro and in vivo immunoregulatory properties of a gluco-arabinan from Angelica dahurica

A water-soluble polysaccharide identified here as ADP80-2 was acquired from Angelica dahurica. ADP80-2 was a gluco-arabinan composed of arabinose and a trace of glucose with a molecular weight of 9950 g/mol. The backbone of ADP80-2 comprised →5)-α-L-Araf-(1→, →3, 5)-α-L-Araf-(1→, →6)-α-D-Glcp-(1→, with a terminal branch α-L-Araf-(1 → residue. In terms of immunoregulatory activity, ADP80-2 can significantly promote the phagocytosis, the production of nitric oxide (NO), and the secretion of cytokines (IL-6, IL-1β, and TNF-α) of macrophage. In addition to the cellular immunomodulatory activities, the chemokines related to immunoregulation were significantly increased in the zebrafish model after treated with ADP80-2. These biological results indicated that ADP80-2 with immunomodulatory effects was expected to be useful for the development of new immunomodulatory agents. Simultaneously, the discovery of ADP80-2 further revealed the chemical composition of A. dahurica used as a traditional Chinese medicine and spice.

Structural analysis and biological effects of a neutral polysaccharide from the fruits of Rosa laevigata

A neutral water-soluble polysaccharide (RLP50-2) was extracted and purified from the fruits of Rosa laevigata. The absolute molecular weight was determined as 1.26 × 10⁴ g/mol. Monosaccharide composition analysis showed that RLP50-2 mainly consisted of glucose, arabinose, and galactose. Structural analysis revealed that RLP50-2 consisted of →5)-α-L-Araf-(1→, →2,5)-α-L-Araf-(1→, →3,5)-α-L-Araf-(1→, →4)-α-D-Glcp-(1→, →6)-α-D-Glcp-(1→, →3,6)-β-D-Glcp-(1→, →4)-α-D-Galp-(1→, →6)-β-D-Galp-(1→, →2)-β-D-Xylp-(1→, terminal α-L-arabinose, and terminal β-D-mannose. Biological assays showed that RLP50-2 had immunomodulatory activities using cell and zebrafish models. Moreover, RLP50-2 showed significantly antitumor activities by inhibiting tumor cell proliferation and migration and blocking angiogenesis. These results suggested that RLP50-2 could be developed as a potential immunomodulatory agent or antitumor candidate drug in biomedicine field.