Advances in Research on Immunoregulation of Macrophages by Plant Polysaccharides

A novel polysaccharide from blueberry leaves: Extraction, structural characterization, hypolipidemic and hypoglycaemic potentials

In this study, the structural characterization, physicochemical properties, antioxidant, hypolipidemic, and hypoglycemic potentials of polysaccharide components (BLP-1, BLP-2, and BLP-3) purified from blueberry leaf polysaccharides (BLP) were investigated. Ion chromatography results showed that BLP-1, BLP-2, and BLP-3 contained rhamnose, arabinose, galactose, glucose, and glucuronic acid. In contrast to BLP-1, BLP-2 and BLP-3 included galacturonic acid. The methylation analysis results indicated that the backbones of BLP-1, BLP-2, and BLP-3 were mainly composed of glycosidic linkages of arabinose, galactose, and glucose, which was consistent with the results of the previously determined monosaccharide composition. The in-vitro antioxidant results showed that BLP-1, BLP-2, and BLP-3 possessed antioxidant activity with the highest scavenging of -OH radicals. Furthermore, BLP-1, BLP-2, and BLP-3 showed high bile acid-binding activity and α-amylase inhibitory activity, suggesting that they have the potentials of hypolipidemic and hypoglycemic. This study provides a reference for the utilization of blueberry leaf resources.

A novel antidepressant homogeneous polysaccharide YLP-1 from Millettia pulchra ameliorates tryptophan metabolism and SCFAs through modulating gut microbiota

The root of Millettia pulchra (YLS) has been traditionally used as a folk medicine for the treatment of depression and insomnia in the Zhuang nationality of China, and its polysaccharides have potential antidepressant effect. In this study, a novel homogeneous polysaccharide (YLP-1) was purified from the crude polysaccharides of YLS, and it is mainly composed of glucose, arabinose and mannose with molar ratio of 87.25%, 10.77%, and 1.98%, respectively. YLP-1 is a novel α-glucan with the backbone of 1,4-Glcp and branched at C6 of 1,4,6-Glcp to combine 1,4-Manp and 1,5-Araf. The microstructure of YLP-1 displayed a uniform ellipsoidal-like chain morphology and dispersed uniformly in solution. YLP-1 effectively ameliorated depression-like ethological behaviors and restored the decreased catecholamine levels in chronic variable stress (CVS)-induced depression rats. Additionally, it significantly improved the disturbance of gut microbiota induced by CVS stimuli, particularly affecting bacteria that produce short-chain fatty acids (SCFAs), such as bacteria species Lactobacillus spp.. In vitro fermentation study further confirmed that YLP-1 intake could promote SCFAs production by Lactobacillus spp. YLP-1 also mitigated the disruption of tryptophan metabolites in urine and serum. These findings provide evidences for the further development of YLP-1 as a macromolecular antidepressant drug.

Application of plant-derived products as adjuvants for immune activation and vaccine development

Vaccines are one of the most important means to prevent and control the epidemic of infectious diseases. Commercial vaccines not only include corresponding antigens, but also need vaccine adjuvants. Immune adjuvants play an increasingly important role in the research, development and manufacture of vaccines. Adjuvants combined with antigens can improve the stability, safety and immune efficiency of vaccines. Some substances that can enhance the immune response have been found in nature(mainly plants) and used as adjuvants in vaccines to improve the immune effect of vaccines. These plant-derived immune adjuvants often have the advantages of low toxicity, high stability, low price, etc., providing more possibilities for vaccine development. We summarized and analyzed the advantages, application research, particulate delivery systems, existing problems and future research focus of botanical adjuvant. It is hoped to provide new ideas for the research and development of immune adjuvants in the future.

Immunomodulatory effects of Fructus corni acidic polysaccharide and its selenium nanoparticles composites in hepatocellular carcinoma

Natural polysaccharides have promising application prospects in cancer immunotherapy due to their excellent biocompatibility and immunomodulatory effects. In this study, an acidic polysaccharide (FCP-3) from Fructus corni with good immunomodulatory effects was extracted. Stable polysaccharide‑selenium nanoparticles composites (FCP-SeNPs) were synthesized to enhance the immunoregulatory effects of FCP-3. The molecular weight and monosaccharide composition of FCP-3, as well as the morphological characteristics and chemical composition of FCP-SeNPs were analyzed. The immunological effects and anti-tumor activity of FCP-3 and FCP-SeNPs were explored. These results suggested that FCP-3 and FCP-SeNPs increased the production of NO, TNF-α and IL-12p70 in macrophages, and the ratio of CD4+/CD8+ T cells in peripheral blood, as well as indirectly promoted hepatoma cells apoptosis in vitro. After treatment with FCP-3 and FCP-SeNPs, tumor size was significantly controlled. The proliferation antigen staining (KI67) and apoptosis assay (TUNEL) also demonstrated an obvious inhibitory effect on tumor proliferation. Moreover, FCP-SeNPs showed stronger efficacy compared to FCP-3 alone. These findings demonstrated the promising potential of FCP-SeNPs as an immunoregulatory agent for hepatic carcinoma.

Effects of traditional Chinese medicine polysaccharides on chronic diseases by modulating gut microbiota: A review

Intestinal tract is the largest immune system of human body. Gut microbiota (GM) can produce a large number of metabolites, such as short-chain fatty acids and bile acids, which regulate the physiological health of the host and affect the development of disease. In recent years, traditional Chinese medicine (TCM) polysaccharides have attracted extensive attention with multiple biological activities and low toxicity. TCM polysaccharides can promote the growth of intestinal beneficial bacteria and inhibit the growth of harmful bacteria by regulating the structure and function of GM, thus playing a crucial role in preventing or treating chronic diseases such as inflammatory bowel disease (IBD), obesity, type 2 diabetes mellitus (T2DM), liver diseases, cancer, etc. In this paper, the research progress of TCM polysaccharides in the treatment of chronic diseases such as inflammatory bowel disease, obesity, T2DM, liver diseases, cancer, etc. by modulating GM was reviewed. Meanwhile, this review makes an in-depth discussion on the shortcomings of the research of TCM polysaccharides on chronic diseases by modulating GM, and new valuable prospection for the future researches of TCM polysaccharides are proposed, which will provide new ideas for the further study of TCM polysaccharides.

Areca nut polysaccharide induces M1 macrophage polarization through the NF-κB and MAPK pathways independent of TLR2 and TLR4 signaling

In this study, the structure of Areca nut polysaccharide (ANP) was characterized, and its effects on macrophage activation and the underlying molecular mechanisms were investigated. ANP was identified as a glucan with a molecular weight of 24.5 kDa, and its structure was analyzed using XRD, SEM, FT-IR, methylation, and NMR techniques. The main chain of ANP is composed of →4)-α-D-Glcp-(1 → and →4,6)-α-D-Glcp-(1→, with a branched α-D-Glcp-(1 → chain. Furthermore, the activation of macrophages by ANP was explored. Stimulation of RAW264.7 cells with ANP in vitro increased the expression of inflammatory cytokines (TNF-α and IL-6) and NO levels. Flow cytometry showed that ANP induced M1 macrophage polarization. RNA-seq and Western blot analyses revealed that ANP activated the NF-κB and MAPK pathways. Importantly, TLR2- and TLR4- specific antibodies did not affect ANP-induced M1 polarization, whereas endocytosis inhibitors reduced the production of inflammatory cytokines in ANP-treated macrophages. In conclusion, ANP engages macrophages without interacting with TLR2 and TLR4 receptors, inducing M1 polarization through the NF-κB and MAPK signaling pathways.

Effect of the immunoregulation activity of a pectin polysaccharide from Saussurea laniceps petals on macrophage polarization

Saussurea laniceps is a traditional medicinal herb. In our previous study, a pectin polysaccharide, SLP-4, was isolated from the petals of S. laniceps. In this study, the immunomodulatory activity of SLP-4 was studied by analyzing its effects on macrophage (RAW 264.7 cells) polarization. The immunomodulatory activity assays indicated that SLP-4 could significantly enhance the pinocytic and phagocytic capacity and promote the expression and secretion of cytotoxic molecules (nitric oxide, increased by 6.4 times when the SLP-4 concentration was 800 μg/mL) and cytokines (tumor necrosis factor-α and interleukin-6 increased by 7.7 and 11.9 times, respectively) in original macrophage. The possible mechanism could be attributed to the activation of the mitogen-activated protein kinase and nuclear factor-κB signaling pathways through Toll-like receptors 2 and 4. Moreover, SLP-4 significantly induced M1 polarization of original macrophages and transferred macrophages from M2 to M1, but had little effect on the conversion of M1 macrophages into M2 phenotype. Overall, these results demonstrate the potential of SLP-4 as an attractive immunomodulating functional supplement.

Study on the mechanism of macrophages activated by phosphoesterified rehmanniae polysaccharide on human gastric cancer cells

Gastric cancer(GC)is one of the most common gastrointestinal malignant tumors in the world, requiring the development of novel therapeutic agents with reduced toxicity. Rehmannia polysaccharide (RPS) possesses immunomodulatory and anti-tumor properties, yet its efficacy is suboptimal. To enhance its biological activity, we subjected RPS to molecular modifications, resulting in phosphorylated Rehmannia polysaccharides (P-RPS). Using the mixed phosphate method, we synthesized P-RPS and optimized the synthesis conditions through a combination of single-factor and response surface methodologies. In vitro studies on P-RPS's anti-tumor activity showed no direct influence on the viability of GC cells. However, P-RPS induced the transformation of PMA-activated THP-1 cells into the M1 phenotype. We collected conditioned medium (CM) of THP-1 cells to stimulate gastric cancer cells and CM-P-RPS significantly promoted apoptosis of gastric cancer cells and inhibited cell proliferation, and reduced cell migration. Mechanistically, CM-P-RPS inhibits the Wnt/β-catenin signaling pathway through LGR6, leading to the suppression of tumor growth. Furthermore, P-RPS demonstrated a significant inhibitory effect on tumor growth in vivo, suggesting its potential as a promising therapeutic agent for GC treatment.

Evaluation of the therapeutic action of original antiviral drug in SARS-CoV-2

Purpose of this article is to study the possible direct antiviral effect of "Armenikum" on SARS-CoV-2, conduct an in vitro study on the SARS-CoV-2 encephalomocarditis virus, and an in vivo study on the Syrian hamster model. Human coronavirus SARS-CoV-2 (delta strain) was used as the virus. Two groups of four-specimen hamsters were used to study the therapeutic activity of the drug during 48 h after infecting. One group of hamsters served as positive control and was infected with the virus at a similar dose as experimental one and was used as a control of pathology induced by the viral infection till the end of the experiment. Another group of hamsters (four of them) was injected physiological solution and was used as a control. The Syrian hamsters underwent a clinical blood test and computed tomography. "Armenikum" in the form of an injection has a significant antiviral effect on the human coronavirus SARS-CoV-2, credibly reducing the titers of the virus and the time of its elimination from the Syrian hamsters, significantly mitigating the viral infection. "Armenikum" in the form of an injection drug almost completely removes the pathological effect of the virus in the lungs of the hamsters.

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

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

Natural plant-derived polysaccharides targeting macrophage polarization: a promising strategy for cancer immunotherapy

Tumor associated macrophages (TAMs) are the predominant innate immune cells in the tumor microenvironment (TME). Cytokines induce the differentiation of macrophages into distinct types of TAMs, primarily characterized by two phenotypes: M1-polarized and M2-polarized. Cancer growth is suppressed by M1-polarized macrophages and promoted by M2-polarized macrophages. The regulation of macrophage M1 polarization has emerged as a promising strategy for cancer immunotherapy. Polysaccharides are important bioactive substances found in numerous plants, manifesting a wide range of noteworthy biological actions, such as immunomodulation, anti-tumor effects, antioxidant capabilities, and antiviral functions. In recent years, there has been a significant increase in interest regarding the immunomodulatory and anti-tumor properties of polysaccharides derived from plants. The regulatory impact of polysaccharides on the immune system is mainly associated with the natural immune response, especially with the regulation of macrophages. This review provides a thorough analysis of the regulatory effects and mechanisms of plant polysaccharides on TAMs. Additionally, an analysis of potential opportunities for clinical translation of plant polysaccharides as immune adjuvants is presented. These insights have greatly advanced the research of plant polysaccharides for immunotherapy in tumor-related applications.

Preparation, characteristic, biological activities, and application of polysaccharide from Lilii Bulbus: a review

OBJECTIVES

This review highlights the current knowledge of polysaccharide from Lilii Bulbus, including the extraction, purification, structure, structure modification, biological activities and application, which will hopefully provide reference for further research and development of polysaccharide from Lilii Bulbus.

MATERIALS AND METHODS

Literature searches were conducted on the following databases: Pubmed, ACS website, Elsevier, Google Scholar, Web of Science and CNKI database. Keywords such as "Lilii Bulbus", "polysaccharide", "preparation", "biological activities" and "application" were used to search relevant journals and contents, and some irrelevant contents were excluded.

RESULTS

In general, the study of Lilium Bulbus polysaccharide extraction and purification, structure characterization and biological activity has made substantial progress, these findings highlight the lilium brownii polysaccharide enormous potential in biomedical applications, of lilium brownii polysaccharide laid a solid foundation for further research.

DISCUSSION AND CONCLUSIONS

However, it should be noted that the relevant mechanism of the effective effect of lily bulb polysaccharide still needs to be worked on by researchers. These findings highlight the great potential of lily polysaccharides in biomedical applications, and lay a solid foundation for further research on lily polysaccharides.

Polysaccharides in fruits: Biological activities, structures, and structure-activity relationships and influencing factors-A review

Fruits are a rich source of polysaccharides, and an increasing number of studies have shown that polysaccharides from fruits have a wide range of biological functions. Here, we thoroughly review recent advances in the study of the bioactivities, structures, and structure-activity relationships of fruit polysaccharides, especially highlighting the structure-activity influencing factors such as extraction methods and chemical modifications. Different extraction methods cause differences in the primary structures of polysaccharides, which in turn lead to different polysaccharide biological activities. Differences in the degree of modification, molecular weight, substitution position, and chain conformation caused by chemical modification can all affect the biological activities of fruit polysaccharides. Furthermore, we summarize the applications of fruit polysaccharides in the fields of pharmacy and medicine, foods, cosmetics, and materials. The challenges and perspectives for fruit polysaccharide research are also discussed.

Reversible ON- and OFF-switch receptors Clec4G and Rab1A reveal the hormetic effects of a pectin polysaccharide in Aralia elata (Miq.) Seem

BACKGROUND

Numerous studies indicate that natural polysaccharides have immune-enhancing effects as a host defense potentiator. Few reports are available on hormetic effects of natural polysaccharides, and the underlying mechanisms remain unclear.

PURPOSE

AELP-B6 (arabinose- and galactose-rich pectin polysaccharide) from Aralia elata (Miq.) Seem was taken as a case study to clarify the potential mechanism of hormetic effects of natural polysaccharides.

METHODS

The pharmacodynamic effect of AELP-B6 was verified by constructing the CTX-immunosuppressive mouse model. The hormetic effects were explored by TMT-labeled proteomics, energy metabolism analysis, flow cytometry and western blot. The core-affinity target of AELP-B6 was determined by pull down, nanoLC-nanoESI+-MS, CETSA, immunoblot and SPR assay. The RAW264.7Clec4G-RFP and RAW264.7Rab1A-RFP cell lines were simultaneously constructed to determine the affinity difference between AELP-B6 and targets by confocal laser scanning live-cell imaging. Antibody blocking assays were further used to verify the mechanism of hormetic effects.

RESULTS

AELP-B6 at low and medium doses may maintain the structural integrity of thymus and spleen, increase the concentrations of TNF-α, IFN-γ, IL-3 and IL-8, and alleviate CTX-induced reduction of immune cell viability in vivo. Proteomics and energy metabolism analysis revealed that AELP-B6 regulate HIF-1α-mediated metabolic programming, causing Warburg effects in macrophages. AELP-B6 at low and medium doses promoted the release of intracellular immune factors, and driving M1-like polarization of macrophages. As a contrast, AELP-B6 at high dose enhanced the expression levels of apoptosis related proteins, indicating activation of the intrinsic apoptotic cascade. Two highly expressed transmembrane proteins in macrophages, Clec4G and Rab1A, were identified as the primary binding targets of AELP-B6 which co-localized with the cell membrane and directly impacted with immune cell activation and apoptosis. AELP-B6 exhibits affinity differences with Clec4G and Rab1A, which is the key to the hormetic effects.

CONCLUSION

We observed hormesis of natural polysaccharide (AELP-B6) for the first time, and AELP-B6 mediates the hormetic effects through two dose-related targets. Low dose of AELP-B6 targets Clec4G, thereby driving the M1-like polarization via regulating NF-κB signaling pathway and HIF-1α-mediated metabolic programming, whereas high dose of AELP-B6 targets Rab1A, leading to mitochondria-dependent apoptosis.

Impact of molecular weight and gastrointestinal digestion on the immunomodulatory effects of Lycium barbarum polysaccharides

In traditional Chinese medicine, Lycium barbarum is of rich medicinal value, and its polysaccharides are particularly interesting due to their significant pharmacological effects and potential health benefits. This study investigated the immunomodulatory effects of Lycium barbarum polysaccharides (LBPs) by examining their interaction with the TLR4/MD-2 complex and the impacts of gastrointestinal digestion on these interactions. We discovered that the affinity binding of LBPs for TLR4/MD-2 and their cytokine induction capability are influenced by molecular weight, with medium-sized LBPs (100-300 kDa) exhibiting stronger binding affinity and induction capability. Conversely, LBPs smaller than 10 kDa showed reduced activity. Additionally, the content of arabinose and galactose within the LBPs fractions was found to correlate positively with both receptor affinity and cytokine secretion. Simulated gastrointestinal digestion resulted in the degradation of LBPs into smaller fragments that are rich in glucose. Although these fragments exhibited decreased binding affinity to the TLR4/MD-2 complex, they maintained their activity to promote cytokine production. Our findings highlight the significance of molecular weight and specific monosaccharide composition in the immunomodulatory function of LBPs and emphasize the influence of gastrointestinal digestion on the effects of LBPs. This research contributes to a better understanding of the mechanisms underlying the immunomodulatory effects of traditional Chinese medicine polysaccharides and their practical application.

Preparation of Rehmanniae Radix Praeparata Polysaccharide Iron(III) Complex and Evaluation of Its Biological Activity

This study extracted and purified a polysaccharide from Rehmanniae radix praeparata (RGP) with an average molecular weight. The structural characteristics of RGP and its iron (III) complex, RGP-Fe(III), were examined for their antioxidant properties and potential in treating iron deficiency anemia (IDA). Analysis revealed that RGP comprised Man, Rha, Gal, and Xyl, with a sugar residue skeleton featuring 1→3; 1→2, 3; and 1→2, 3, 4 linkages, among others. RGP-Fe(III) had a molecular weight of 4.39×104 Da. Notably, RGP-Fe(III) exhibited superior antioxidant activity compared to RGP alone. In IDA rat models, treatment with RGP-Fe(III) led to increased weight gain, restoration of key blood parameters including hemoglobin, red blood cells, and mean hemoglobin content, elevated serum iron levels, and decreased total iron-binding capacity. Histological examination revealed no observable toxic effects of RGP-Fe(III) on the liver and spleen. These findings suggest the potential of RGP-Fe(III) as a therapeutic agent for managing IDA and highlight its promising antioxidant properties.

Immunomodulatory, Antioxidant, and Potential Anticancer Activity of the Polysaccharides of the Fungus Fomitiporia chilensis

Fomitiporia species have aroused the interest of numerous investigations that reveal their biological activity and medicinal potential. The present investigation shows the antioxidant, anticancer, and immunomodulatory activity of acidic polysaccharides obtained from the fungus Fomitiporia chilensis. The acidic polysaccharides were obtained for acidic precipitation with 2% O-N-cetylpyridinium bromide. Chemical analysis was performed using FT-IR and GC-MS methods. The antioxidant capacity of acidic polysaccharides from F. chilensis was evaluated by scavenging free radicals with an ABTS assay. Macrophage proliferation and cytokine production assays were used to determine the immunomodulatory capacity of the polysaccharides. Anti-tumor and cytotoxicity activity was evaluated with an MTT assay in the U-937, HTC-116, and HGF-1 cell lines. The effect of polysaccharides on the cell cycle of the HCT-116 cell line was determined for flow cytometry. Fourier Transform-infrared characterization revealed characteristic absorption peaks for polysaccharides, whereas the GC-MS analysis detected three peaks corresponding to D-galactose, galacturonic acid, and D-glucose. The secreted TNF-α concentration was increased when the cell was treated with 2 mg mL-1 polysaccharides, whereas the IL-6 concentration was increased with all of the evaluated polysaccharide concentrations. A cell cycle analysis of HTC-116 treated with polysaccharides evidenced that the acidic polysaccharides from F. chilensis induce an increase in the G0/G1 cell cycle phase, increasing the apoptotic cell percentage. Results from a proteomic analysis suggest that some of the molecular mechanisms involved in their antioxidant and cellular detoxifying effects and justify their traditional use in heart diseases. Proteomic data are available through ProteomeXchange under identifier PXD048361. The study on acidic polysaccharides from F. chilensis has unveiled their diverse biological activities, including antioxidant, anticancer, and immunomodulatory effects. These findings underscore the promising therapeutic applications of acidic polysaccharides from F. chilensis, warranting further pharmaceutical and medicinal research exploration.

Fingerprint profiling for quality evaluation and the related biological activity analysis of polysaccharides from Liuweizhiji Gegen-Sangshen beverage

Introduction

Liuweizhiji Gegen-Sangshen beverage (LGS) is popular in China, which has been used for alleviating alcohol-mediated discomfort and preventing alcoholic liver disease (ALD). This beverage is consisted of six herbal components that are known as functional foods and fruits. LGS is rich in polysaccharides, however, the activity and quality evaluation of LGS-derived polysaccharides remain unexplored. The purpose of this study is thus to establish a comprehensive quality control methodology for the assessment of LGS polysaccharides (LGSP) and to further explore the anti-oxidant, anti-inflammatory as well as prebiotic effect of LGSP.

Methods

LGSP was extracted, followed by analysis of molecular weight distribution, monosaccharide content and structural characterization via integrating the application of high-performance size exclusion chromatography (HPSEC), 1-phenyl-3-methyl-5-pyrazolone-HPLC (PMP-HPLC), fourier transform infrared spectroscopy (FT-IR) as well as nuclear magnetic resonance spectroscopy (NMR) techniques. The anti-oxidation activity of LGSP was determined by DPPH, ABTS, hydroxyl radical scavenging capacity and total antioxidant capacity. The anti-inflammation of LGSP were assessed on the RAW 264.7 cells. The effect of LGSP on growth of Lactobacillus, Bifidobacterium bifidum and Bifidobacterium adolescentis was evaluated.

Results

The results demonstrated that LGSP had two molecular weight distribution peaks, with the average molecular weights of (6.569 ± 0.12) × 104 Da and (4.641 ± 0.30) × 104 Da. LGSP was composed of 8 monosaccharides, with galacturonic acid, glucose rhamnose and galactose representing the highest molar ratios. Homogalacturonic acid (HG) type and rhamnosegalacturonic acid glycans I (RG-I) type and α-1,4-glucan were present in LGSP. LGSP concentration in LGS was 17.94 ± 0.28 mg/mL. Furthermore, fingerprint analysis combined with composition quantification of 10 batches of LGSP demonstrated that there was a high similarity among batches. Notably, LGSP exhibited anti-oxidant effect and inhibited expressions of pro-inflammatory factors (TNF-α and IL-6) in LPS-stimulated RAW 264.7 cells. In addition, LGSP remarkably promoted the proliferation of probiotics Lactobacillus, Bifidobacterium bifidum and Bifidobacterium adolescentis, showing good prebiotic activity.

Discussion

The results of present study would be of help to gain the understanding of structure-activity relationship of LGSP, provide a reference for quality evaluation of bioactive LGSP, and facilitate development of unique health and functional products in the future.

Structure and antitumor activity of a polysaccharide from Rosa roxburghii

It is well known that Rosa roxburghii, as a homology of both medicine and food, is rich in polysaccharides. To discover bioactive macromolecules for combating cancer, the polysaccharides in R. roxburghii were investigated, leading to the purification of a polysaccharide (RRTP80-1). RRTP80-1 was measured to have an average molecular weight of 8.65 × 103 g/mol. Monosaccharide composition analysis revealed that RRTP80-1 was formed from three types of monosaccharides including arabinose, glucose, and galactose. Methylation and GC-MS analysis suggested that the backbone of RRTP80-1 consisted of →5)-α-l-Araf-(1→, →6)-α-d-Glcp-(1→, →2,5)-α-l-Araf-(1→, →4,6)-β-d-Galp-(1→, and →3)-α-l-Araf-(1→, with branch chains composed of α-l-Araf-(1→. In vivo studies indicated that RRTP80-1 exhibited inhibitory activity against the growth and proliferation of neoplasms in the zebrafish tumor xenograft model by suppressing angiogenesis. Additionally, RRTP80-1 was found to upregulate reactive oxygen species (ROS) and nitric oxide (NO) production levels in zebrafish models. All these studies suggest that RRTP80-1 activates the immune system to inhibit tumors. The potential role of the newly discovered homogeneous polysaccharide RRTP80-1 in cancer treatment was preliminarily clarified in this study.

Elucidating Korean meadowsweet (Filipendula glaberrima Nakai)-derived arabinogalactan protein-induced macrophage activation and its associated mechanism of action

This study aimed to confirm macrophage-stimulatory component from Korean meadowsweet (Filipendula glaberrima; FG) and characterize its compositional and structural properties. FG-CWH, prepared via cool-water extraction and ethanol precipitation, induced the highest secretion of NO (6.0-8.0 μM), TNF-α (8.7-9.5 ng/mL), and IL-6 (1.0-5.7 ng/mL) compared to other samples at 0.4-10 μg/mL in RAW 264.7 cells. Analytical results revealed that FG-CWH is a high-molecular-weight component with an average molecular weight of 220 kDa, constituting a polysaccharide-protein mixture. Chemical and enzymatic treatment of FG-CWH indicated its primary composition as arabinogalactan protein (AGP)-rich glycoprotein, with activity likely associated with the chemical and structural characteristics of AGP. FG-CWH treatment resulted in significant and concentration-dependent increases in iNOS (20.0-29.6 folds), TNFα (10.6-18.6 folds) and IL6 (10.9-155.6 folds) gene expression, as well as the secretion of NO (5.3-6.3 μM), TNF-α (35.4-44.3 ng/mL), and IL-6 (4.1-8.4 ng/mL) secretion, even at a reduced concentration range of 125-500 ng/mL, compared to the negative control group. Immunoblotting analysis indicated FG-CWH-induced macrophage stimulation significantly associated with the activation of MAPK (ERK, JNK, and p38) and NF-κB (p65 and IκBα). These findings can serve as valuable groundwork for developing FG-derived AGP as novel functional ingredients to enhance human immunity.

Polysaccharides from Porphyra haitanensis: A Review of Their Extraction, Modification, Structures, and Bioactivities

Porphyra haitanensis (P. haitanensis), an important food source for coastal residents in China, has a long history of medicinal and edible value. P. haitanensis polysaccharides are some of the main active ingredients in P. haitanensis. It is worth noting that P. haitanensis polysaccharides have a surprising and satisfactory biological activity, which explains the various benefits of P. haitanensis to human health, such as anti-oxidation, immune regulation, anti-allergy, and anticancer properties. Hence, a systematic review aimed at comprehensively summarizing the recent research advances in P. haitanensis polysaccharides is necessary for promoting their better understanding. In this review, we systematically and comprehensively summarize the research progress on the extraction, purification, structural characterization, modification, and biological activity of P. haitanensis polysaccharides and address the shortcomings of the published research and suggest area of focus for future research, providing a new reference for the exploitation of polysaccharides from P. haitanensis in the fields of medicine and functional foods.

Current landscape of fecal microbiota transplantation in treating depression

Depression, projected to be the predominant contributor to the global disease burden, is a complex condition with diverse symptoms including mood disturbances and cognitive impairments. Traditional treatments such as medication and psychotherapy often fall short, prompting the pursuit of alternative interventions. Recent research has highlighted the significant role of gut microbiota in mental health, influencing emotional and neural regulation. Fecal microbiota transplantation (FMT), the infusion of fecal matter from a healthy donor into the gut of a patient, emerges as a promising strategy to ameliorate depressive symptoms by restoring gut microbial balance. The microbial-gut-brain (MGB) axis represents a critical pathway through which to potentially rectify dysbiosis and modulate neuropsychiatric outcomes. Preclinical studies reveal that FMT can enhance neurochemicals and reduce inflammatory markers, thereby alleviating depressive behaviors. Moreover, FMT has shown promise in clinical settings, improving gastrointestinal symptoms and overall quality of life in patients with depression. The review highlights the role of the gut-brain axis in depression and the need for further research to validate the long-term safety and efficacy of FMT, identify specific therapeutic microbial strains, and develop targeted microbial modulation strategies. Advancing our understanding of FMT could revolutionize depression treatment, shifting the paradigm toward microbiome-targeting therapies.

Recent Advances in Polysaccharides from Chaenomeles speciosa (Sweet) Nakai.: Extraction, Purification, Structural Characteristics, Health Benefits, and Applications

This article systematically reviews the extraction and purification methods, structural characteristics, structure-activity relationship, and health benefits of C. speciosa polysaccharides, and their potential application in food, medicine, functional products, and feed, in order to provide a useful reference for future research. Chaenomeles speciosa (Sweet) Nakai. has attracted the attention of health consumers and medical researchers as a traditional Chinese medicine with edible, medicinal, and nutritional benefits. According to this study, C. speciosa polysaccharides have significant health benefits, such as anti-diaetic, anti-inflammatory and analgesic, anti-tumor, and immunomodulatory effects. Researchers determined the molecular weight, structural characteristics, and monosaccharide composition and ratio of C. speciosa polysaccharides by water extraction and alcohol precipitation. This study will lay a solid foundation for further optimization of the extraction process of C. speciosa polysaccharides and the development of their products. As an active ingredient with high value, C. speciosa polysaccharides are worthy of further study and full development. C. speciosa polysaccharides should be further explored in the future, to innovate their extraction methods, enrich their types and biological activities, and lay a solid foundation for further research and development of products containing polysaccharides that are beneficial to the human body.

Impacts of monosaccharide composition on immunomodulation by cello-pentaose, manno-pentaose, and xylo-pentaose: Unraveling the underlying molecular mechanisms

Different types of functional oligosaccharides exhibit varying degrees of immune-enhancing effects, which might be attributable to differences in their glycosyl structures. The differences in the immunomodulatory action of three functional oligosaccharides with distinct glycosyl compositions: cello-oligosaccharides (COS), manno-oligosaccharides (MOS), and xylo-oligosaccharides (XOS), were investigated in mouse-derived macrophage RAW264.7. Moreover, the immune enhancement mechanism of oligosaccharides with diverse glycosyl compositions was investigated from a molecular interaction perspective. The TLR4-dependent immunoregulatory effect of functional oligosaccharides was shown by measuring the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in RAW264.7 cells treated with different functional oligosaccharides, both with and without Resatorvid [TAK-242] (a Toll-like receptor 4 [TLR4] inhibitor). Western blot analysis showed that binding of the three oligosaccharides to TLR4 activated the downstream signaling pathway and consequently enhanced the immune response. The fluorescence spectra and molecular docking results revealed that the main mechanisms by which these oligosaccharides attach to the TLR4 active pocket are hydrogen bonds and van der Waals forces. Functional oligosaccharides were ranked according to their affinity for TLR4, as follows: MOS > COS > XOS, indicating that oligosaccharides or polysaccharides containing mannose units may confer significant advantages for immune enhancement.

Isolation, structural, biological activity and application of Gleditsia species seeds galactomannans

Gleditsia fruits have been known as a valuable traditional Chinese herb for tens of centuries. Previous studies showed that the galactomannans are considered as one of the major bioactive components in Gleditsia fruits seeds (GSGs). Here, we systematically review the major studies of GSGs in recent years to promote their better understanding. The extraction methods of GSGs mainly include hot water extraction, microwave-assisted extraction, ultrasonic extraction, acid extraction, and alkali extraction. The analysis revealed that GGSs exhibited in the form of semi-flexible coils, and its molecular weight ranged from 0.018 × 103 to 2.778 × 103 KDa. GSGs are composed of various monosaccharide constituents such as mannose, galactose, glucose, and arabinose. In terms of pharmacological effects, GSGs exhibit excellent activity in antioxidation, hypoglycemic, hypolipidemic, anti-inflammation. Moreover, GSGs have excellent bioavailability, biocompatibility, and biodegradability, which make them used in food additives, food packaging, pharmaceutical field, industry and agriculture. Of cause, the shortcomings of the current research and the potential development and future research are also highlighted. We believe our work provides comprehensive knowledge and underpinnings for further research and development of GSGs.

Cu-Tremella fuciformis polysaccharide-based tumor microenvironment-responsive injectable gels for cuproptosis-based synergistic osteosarcoma therapy

Cuproptosis affects osteosarcoma locally, and the exploitation of cuproptosis-related biomaterials for osteosarcoma treatment is still in its infancy. We designed and synthesized a novel injectable gel of Cu ion-coordinated Tremella fuciformis polysaccharide (TFP-Cu) for antiosteosarcoma therapy. This material has antitumor effects, the ability to stimulate immunity and promote bone formation, and a controlled Cu2+ release profile in smart response to tumor microenvironment stimulation. TFP-Cu can selectively inhibit the proliferation of K7M2 tumor cells by arresting the cell cycle and promoting cell apoptosis and cuproptosis. TFP-Cu also promoted the M1 polarization of RAW264.7 cells and regulated the immune microenvironment. These effects increased osteogenic gene and protein expression in MC3T3-E1 cells. TFP-Cu could significantly limit tumor growth in tumor-bearing mice by inducing tumor cell apoptosis and improving the activation of anti-CD8 T cell-mediated immune responses. Therefore, TFP-Cu could be a potential candidate for treating osteosarcoma and bioactive drug carrier for further cancer-related applications.

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.

Investigation of natural deep eutectic solvent for the extraction of crude polysaccharide from Polygonatum kingianum and influence of metal elements on its immunomodulatory effects

In this study, natural deep eutectic solvent (NADES) was used to extract Polygonatum kingianum crude polysaccharide (PKCP) and response surface methodology (RSM) was designed to optimize the extraction procedure. The immunomodulatory effect of PKCP and the influence of metal elements on its immunomodulatory effect were further discussed. The optimum conditions for PKCP extraction were obtained by RSM optimization: NADES were synthesized with a 1:2 choline chloride-glycerol molar ratio, then extracted at a liquid-solid ratio of 16.6 mL g-1 and water content of 31.2 % for 60 min at 60 °C. This method was used for the extraction of PKCP, and the extraction efficiency was 29.69 %, which was 2.5 times greater than the conventional method of water extraction. In the concentration range of 200-800 μg mL-1, PKCP could activate macrophages, promoting NO secretion and mRNA expression of interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) in a dose-dependent way. NO secretion and cytokine expression were not affected when the metal elements were spiked to the equivalent of the metal elements contained in Polygonatum kingianum. When the content of metal elements was higher, the secretion of NO and the gene expression of iNOS were both decreased, which may affect the immunomodulatory effect of Polygonatum kingianum.

Research progress and future development potential of Flammulina velutipes polysaccharides in the preparation process, structure analysis, biology, and pharmacology: A review

In recent years, Flammulina velutipes (F. velutipes) has attracted consequential attention in various research fields due to its rich composition of proteins, vitamins, amino acids, polysaccharides, and polyphenols. F. velutipes polysaccharides (FVPs) are considered as key bioactive components of F. velutipes, demonstrating multiple physiological activities, including immunomodulatory, anti-inflammatory, and antibacterial properties. Moreover, they offer health benefits such as antioxidant and anti-aging properties, which have exceptionally valuable clinical applications. Polysaccharides derived from different sources exhibit a wide range of biomedical functions and distinct biological activities. The varied biological functions of polysaccharides, coupled with their extensive application in functional foods and clinical applications, have prompted a heightened focus on polysaccharide research. Additionally, the extraction, deproteinization, and purification of FVPs are fundamental to investigate the structure and biological activities of polysaccharides. Therefore, this review provides a comprehensive and systematic overview of the extraction, deproteinization, purification, characterization, and structural elucidation of FVPs. Furthermore, the biological activities and mechanisms of FVPs have been further explored through in vivo and in vitro experiments. This review aims to provide a theoretical foundation and guide future research and development of FVPs.

An arabinose-rich heteropolysaccharide isolated from Belamcanda chinensis (L.) DC treats liver cancer by targeting FAK and activating CD40

An undisclosed polysaccharide, BCP80-2, was isolated from Belamcanda chinensis (L.) DC. Structural investigation revealed that BCP80-2 consists of ten monosaccharide residues including t-α-Araf-(1→, →3,5)-α-Araf-(1→, →5)-α-Araf-(1→, →4)-β-Xylp-(1→, →3)-α-Rhap-(1→, →4)-β-Manp-(1→, t-β-Glcp-(1→, →6)-α-Glcp-(1→, t-β-Galp-(1→, and→3)-α-Galp-(1→. In vivo activity assays showed that BCP80-2 significantly suppressed neoplasmic growth, metastasis, and angiogenesis in zebrafish. Mechanistic studies have shown that BCP80-2 inhibited cell migration of HepG2 cells by suppressing the FAK signaling pathway. Moreover, BCP80-2 also activated immunomodulation and upregulated the secretion of co-stimulatory molecules CD40, CD86, CD80, and MHC-II. In conclusion, BCP80-2 inhibited tumor progression by targeting the FAK signaling pathway and activating CD40-induced adaptive immunity.

Structure and immunostimulatory activity studies on two novel Flammulina velutipes polysaccharides: revealing potential impacts of →6)-α-D-Glcp(1→ on the TLR-4/MyD88/NF-κB pathway

Two novel Flammulina velutipes (F. velutipes) polysaccharides, FVPH1 and FVPH2, were isolated and purified after hot water extraction. The structural characterization revealed that the backbone of FVPH1 consisted mainly of →6)-α-D-Glcp(1→, →3,4)-α-D-Galp(1→, →4)-α-L-Fucp(1→, and →4)-β-D-Manp(1→, while the backbone of FVPH2 consisted of →3)-α-D-Galp(1→, →3,4)-α-D-Manp(1→,→6)-α-D-Glcp(1→. The branches of FVPH1 contained →6)-α-D-Glcp(1→ and α-D-Glcp(1→ and the branches of FVPH2 consisted of →3)-α-D-Galp(1→, →6)-α-D-Glcp(1→, and β-L-Fucp(1→. FVPH2 exhibited significantly better immunostimulatory activity than FVPH1 (P < 0.05), as evidenced by the increased expression of NO, IL-1β, IL-6, and TNF-α and pinocytic activity of RAW264.7 cells. As the most abundant structure in the polysaccharides of F. velutipes, the content of →6)-α-D-Glcp(1→ might play a crucial role in influencing the immunostimulatory activity of F. velutipes polysaccharides. The F. velutipes polysaccharide with a lower content of →6)-α-D-Glcp(1→ and a higher branching degree could significantly enhance the immunostimulatory activity of F. velutipes polysaccharides via activating the TLR-4/MyD88/NF-κB pathway more effectively.

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.

Melanoidin-like carbohydrate-containing macromolecules from Shanxi aged vinegar exert immunoenhancing effects on macrophage RAW264.7 cells

Bioactive macromolecule mining is important for the functional chemome analysis of traditional Chinese vinegar. In this study, we isolated and characterized carbohydrate-containing macromolecules from Shanxi aged vinegar (CCMSAV) and evaluated their immunomodulatory activity. The isolation process involved ethanol precipitation, deproteinization, decolorization, and DEAE-650 M column chromatography, resulting in the acquisition of four sub-fractions. All sub-fractions exhibited a molecular weight range of 6.92 to 16.71 kDa and were composed of 10 types of monosaccharides. Comparative analysis of these sub-fractions with two melanoidins exhibited similarities in elemental composition, spectral signature, and pyrolytic characteristics. Immunological assays confirmed the significantly enhanced cell viability, phagocytic activity, and secretion of nitric oxide, tumor necrosis factor (TNF)-α and interleukin (IL)-6 in RAW264.7 cells by all four sub-fractions. Further investigation of the immunomodulatory mechanism revealed that SAV-RP70-X, the most potent purified sub-fraction, enhanced aerobic glycolysis in macrophages and activated Toll-like receptor 2 (TLR2), TLR4, mannose receptor (MR), scavenger receptor (SR), and the dendritic cell-associated C-type lectin-1 receptor (Dectin-1). Furthermore, the activation of macrophages was associated with the MyD88/PI3K/Akt/NF-κB signaling pathway. Methylation analysis revealed that 1,4-Xylp was the most abundant glycosidic linkage in SAV-RP70-X.

A new perspective on structural characterisation and immunomodulatory activity of arabinogalactan in Larix kaempferi from Qinling Mountains

In this study, crude polysaccharide (LAG-C) and homogeneous arabinogalactan (LAG-W) were isolated from Qinling Larix kaempferi of Shaanxi Province. Bioactivity assays showed that LAG-W and LAG-C enhanced the phagocytic ability, NO secretion, acid phosphatase activity, and cytokine production (IL-6, IL-1β, and TNF-α) of RAW264.7 macrophages. Notably, LAG-W exhibited a significantly stronger immunomodulatory effect than LAG-C. The primary structure of LAG-W was characterised by chemical methods (monosaccharide composition, methylation analysis, and alkali treatment) and spectroscopic techniques (gas chromatography-mass spectrometry, high-performance liquid chromatography-mass spectrometry, and 1D/2D nuclear magnetic resonance). LAG-W was identified as a 22.08 kilodaltons (kDa) neutral polysaccharide composed of arabinose and galactose at a 1:7.5 molar ratio. Its backbone consisted of repeated →3)-β-Galp-(1→ residues. Side chains, connected at the O-6 position, were mainly composed of T-β-Galp-(1→ and T-β-Galp-(1→6)-β-Galp-(1→ residues. And it also contained small amounts of T-β-Arap-(1→, T-α-Araf-(1→6)-β-Galp-(1→6)-β-Galp-(1→, and T-α-Araf-(1→3)-α-Araf-(1→6)-β-Galp-(1→ residues. By structurally and functionally characterising L. kaempferi polysaccharides, this study opens the way for the valorisation of this species.

Ameliorative effect of an acidic polysaccharide from Phellinus linteus on ulcerative colitis in a DSS-induced mouse model

Phellinus linteus, a rare medicinal fungus, displays strong antitumor and anti-inflammatory activities because of its active metabolites, particularly polysaccharides. We investigated effects of P. linteus acidic polysaccharide (PLAP) on amelioration of dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in a mouse model, and associated mechanisms. PLAP treatment alleviated major UC symptoms (weight loss, reduced food intake, increased disease activity index), and ameliorated histopathological colon tissue damage, reduced levels of pro-inflammatory factors (TNF-α, IL-6, IL-1β), enhanced anti-inflammatory factor IL-10 level, reduced levels of oxidative stress-related enzymes iNOS and MPO, and enhanced expression of tight junction proteins (ZO-1, occludin, claudin-1). qPCR analysis revealed that PLAP downregulated phosphorylation levels of p65 and p38 and transcriptional level of TLR-4. High-throughput sequencing showed that PLAP restored gut microbiota diversity and species abundances in the UC model, and gas chromatographic analysis showed that it increased levels of beneficial short-chain fatty acids. Our findings indicate that PLAP has strong potential for development as an anti-UC agent based on its reduction of inflammation and oxidative stress levels, modulation of gut microbiota composition, and promotion of normal intestinal barrier function.

Advances in the regulation of radiation-induced apoptosis by polysaccharides: A review

Polysaccharides are biomolecules composed of monosaccharides that are widely found in animals, plants and microorganisms and are of interest for their various health benefits. Cumulative studies have shown that the modulation of radiation-induced apoptosis by polysaccharides can be effective in preventing and treating a wide range of radiation injuries with safety and few side effects. Therefore, this paper summarizes the monosaccharide compositions, molecular weights, and structure-activity relationships of natural polysaccharides that regulate radiation-induced apoptosis, and also reviews the molecular mechanisms by which these polysaccharides modulate radiation-induced apoptosis, primarily focusing on promoting cancer cell apoptosis to enhance radiotherapy efficacy, reducing radiation damage to normal tissues, and inhibiting apoptosis in normal cells. Additionally, the role of gut microbiota in mediating the interaction between polysaccharides and radiation is discussed, providing innovative ideas for various radiation injuries, including hematopoiesis, immunity, and organ damage. This review will contribute to a better understanding of the value of natural polysaccharides in the field of radiation and provide guidance for the development of natural radioprotective agents and radiosensitizers.

Analyzing the structure-activity relationship of raspberry polysaccharides using interpretable artificial neural network model

The structure-activity relationship has been a hot topic in the field of polysaccharide research. Six polysaccharides and three polysaccharide fragments were obtained from raspberry pulp. Based on their structural information and immune-enhancing activity data, an artificial neural network (ANN) model was used for prediction, and Gradient-weighted class activation mapping (Grad-CAM) algorithm was exploited for explanation structure-activity relationship of these raspberry polysaccharides in the present study. The structural information and immune activity data of raspberry polysaccharides were respectively used as input and output in the ANN model. The training and testing losses of ANN model was no longer decreased after trained for 200 epochs. The mean-square error (MSE) of training set and test set stabilized around 0.003 and 0.013, and the mean absolute percentage error (MAPE) of training set and test set were 0.21 % and 0.98 %, indicating the trained ANN model converged well and exhibited strong robustness. The interpretability analysis showed that molecular weight, content of arabinose, galactose or galacturonic acid, and glycosyl linkage patterns of →3)-Arap-(1→, Araf-(1→, →4)-Galp-(1 → were the main structural factors greatly affecting the immune-enhancing activity of raspberry polysaccharides. This work may provide a new perspective for the study of structure-activity relationship of polysaccharides.

Isolation, purification, and structural characterization of polysaccharides from Codonopsis pilosula and its therapeutic effects on non-alcoholic fatty liver disease in vitro and in vivo

Codonopsis pilosula is a famous edible and medicinal plants, in which polysaccharides are recognized as one of the important active ingredients. A neutral polysaccharide (CPP-1) was purified from C. pilosula. The structure was characterized by HPSEC-MALLS-RID, UV, FT-IR, GC-MS, methylation analysis, and NMR. The results showed that CPP-1 was a homogeneous pure polysaccharide, mainly containing fructose and glucose, and a small amount of arabinose. Methylation analysis showed that CPP-1 composed of →1)-Fruf-(2→, Fruf-(1→ and Glcp-(1→ residues. Combined the NMR results the structure of CPP-1 was confirmed as α-D-Glcp-(1 → [2)-β-D-Fruf-(1 → 2)-β-D-Fruf-(1]26 → 2)-β-D-Fruf with the molecular weight of 4.890 × 103 Da. The model of AML12 hepatocyte fat damage was established in vitro. The results showed that CPP-1 could increase the activity of SOD and CAT antioxidant enzymes and reduce the content of MDA, thus protecting cells from oxidative damage. Subsequently, the liver protective effect of CPP-1 was studied in the mouse model of nonalcoholic fatty liver disease (NAFLD) induced by the high-fat diet. The results showed that CPP-1 significantly reduced the body weight, liver index, and body fat index of NAFLD mice, and significantly improved liver function. Therefore, CPP-1 should be a potential candidate for the treatment of NAFLD.

Purification, structural characterization, and immunomodulatory activity of two polysaccharides from Portulaca oleracea L

In present study, two water-soluble polysaccharides designated as POL-1 and POL-2 were purified from purslane and their structural characteristics as well as immunomodulatory activity were investigated. The weight-average molecular weight (Mw) of POL-1 and POL-2 were determined to be 64,100 Da and 21,000 Da, respectively. Comprehensive techniques including UV, IR, GC-MS, and NMR were applied to deduced that POL-1 was a pectin polysaccharide homogalacturonan (HG) consisting of →4)-α-GalpA-(1→ with methyl ester degree of 9.71 % and acetylation degree of 0.34 %, while POL-2 was composed of a 1, 4-linked β-Galp backbone substituted by short side chain →4)-α-Glcp-(1→ and →6)-α-Glcp-(1→. The →4)-α-Glcp-(1→ was attached at the O-6 position of →4)-β-Galp-(1→. TEM further revealed that POL-1 was non-branched single chains, while POL-2 was entangled microstructure with side chains. Moreover, POL-2 significantly promoted macrophage phagocytosis as well as the secretion of NO and cytokines (TNF-α, IL-6) through activating NF-κB signaling pathway, thus demonstrating potential immunomodulatory activity. These findings suggested that purslane may be exploited as a potential adjuvant and dietary supplement with immunostimulatory purpose.

Extraction, purification, structural characteristics, bioactivity and potential applications of polysaccharides from Avena sativa L.: A review

Avena sativa L. (A. sativa L.), commonly known as oat, is a significant cereal grain crop with excellent edible and medicinal value. Oat polysaccharides (OPs), the major bioactive components of A. sativa L., have received considerable attention due to their beneficial bioactivities. However, the isolation and purification methods of OPs lack innovation, and the structure-activity relationship remains unexplored. This review emphatically summarized recent progress in the extraction and purification methods, structural characteristics, biological activities, structure-to-function associations and the potential application status of OPs. Different materials and isolation methods can result in the differences in the structure and bioactivity of OPs. OPs are mainly composed of various monosaccharide constituents, including glucose, arabinose and mannose, along with galactose, xylose and rhamnose in different molar ratios and types of glycosidic bonds. OPs exhibited a broad molecular weight distribution, ranging from 1.34 × 105 Da to 4.1 × 106 Da. Moreover, structure-activity relationships demonstrated that the monosaccharide composition, molecular weight, linkage types, and chemical modifications are closely related to their multiple bioactivities, including immunomodulatory activity, antioxidant effect, anti-inflammatory activity, antitumor effects etc. This work can provide comprehensive knowledge, update information and promising directions for future exploitation and application of OPs as therapeutic agents and multifunctional food additives.

Long-term music stimulating alleviated the inflammatory responses caused by acute noise stress on the immune organs of broilers by NF-κB signaling pathway

As an environmental enrichment, music can positively influence the immune function, while noise has an adverse effect on the physical and mental health of humans and animals. However, whether music-enriched environments mitigate noise-induced acute stress remains unclear. To investigate the anti-inflammatory effects of music on the immune organs of broiler chickens under conditions of early-life acute noise stress, 140 one-day-old white feather broilers (AA) were randomly divided into four groups: control (C), the music stimulation (M) group, the acute noise stimulation (N) group, the acute noise stimulation followed by music (NM) group. At 14 days of age, the N and NM groups received 120 dB noise stimulation for 10 min for one week. After acute noise stimulation, the NM group and M group were subjected to continuous music stimulation for 14 days (6 h per day, 60 dB). At 28 days of age, the body temperature of the chicks, the histopathological changes, quantification of ROS-positive density and apoptosis positivity in tissues of spleen, thymus, and bursa of Fabricius (BF) were measured. The results showed that acute noise stimulation led to an increase in the number and area of splenic microsomes and the cortex/medulla ratio of the detected immune organs. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of immune tissues of broilers in N group were decreased compared to the broilers in C group, while the mRNA levels of malondialdehyde (MDA), TNF-α, IL-1, and IL-1β increased. In addition, the gene and protein expression levels of IKK, NF-κB, and IFN-γ of three immune organs from broilers in the N group were increased. Compared to the C and N group, chickens from the NM group showed a decrease in the number and area of splenic follicles, an increase in the activities of SOD and GSH-Px, and a decrease in the expression levels of MDA, TNF-α, IL-1, and IL-1β. Therefore, a music-enriched environment can attenuate oxidative stress induced by acute noise stimulation, inhibiting the activation of the NF-κB signaling pathway and consequently alleviating the inflammatory response in immune organs.

Evaluation of the Polysaccharide "Immeran" Activity in Syrian hamsters' Model of SARS-CoV-2

COVID-19 is a highly contagious respiratory disease with a high number of lethal cases in humans, which causes the need to search for new therapeutic agents. Polysaccharides could be one of the prospective types of molecules with a large variety of biological activities, especially antiviral. The aim of this work was to study the specific antiviral activity of the drug "Immeran" on a model of a new coronavirus infection SARS-CoV-2 in hamsters. Based on the second experiment, intraperitoneal treatment with the drug according to a treatment regimen in doses of 500 and 1000 μg/kg (administration after an hour, then once a day every other day, a total of 3 administrations) was effective, reliably suppressing the replication of the virus in the lungs and, at a dose of 1000 μg/kg, prevented weight loss in animals. In all cases, the treatment stimulated the formation of virus-neutralizing antibodies to the SARS-CoV-2 virus, which suggests that the drug possesses adjuvant properties.

Effect of subcritical water temperature on the structure, antioxidant activity and immune activity of polysaccharides from Glycyrrhiza inflata Batalin

In this study, the polysaccharide from Glycyrrhiza inflata Batalin extracted by hot water (HW-GP) was further physically modified with subcritical water to obtain novel polysaccharides (SW-GP). Comparative analysis was conducted to examine the disparities in conformation and bioactivity between HW-GP and SW-GP, aiming to precisely regulate the structure of the polysaccharides and enhance their bioactivity by controlling subcritical water temperature. The results showed that, compared with HW-GP, subcritical water modification (100-160 °C) not only significantly reduced the molecular weight of polysaccharides (from 5.586 × 105 g/mol to 1.484 × 105 g/mol), but also modulated the intermolecular interaction forces, which maintain the conformation of the polysaccharides, including electrostatic and hydrophobic interactions, thereby dynamically transforming the polysaccharide chain conformation from triple helix to random coil, and the strength of the chain conformation shifted from rigid to flexible. In addition, the modification of the SW-GP structure by subcritical water also enhanced its biological activity. SW-GP (140 °C) with low molecular weight and semi-rigid triple helix conformation showed the best scavenging effect on the DPPH, ABTS, and hydroxyl radicals, and exhibited excellent antioxidant activity. SW-GP (130 °C) with medium molecular weight and semi-rigid triple helix conformation significantly promoted the proliferation and phagocytosis of RAW264.7 cells, as well as increased the release levels of NO, TNF-α, IL-6, and IL-1β, and the immunomodulatory activity was much higher than that of other polysaccharides. These findings confirmed the feasibility of using subcritical water temperature as a regulatory feature for the structure and bioactivity of glycyrrhiza polysaccharides, which may have reference significance for the modification of polysaccharides with heightened bioactivity.

Effect of subcritical water temperature on the chain conformation and immune activity of ginger polysaccharides

In this study, the ginger polysaccharides extracted from hot water (HW-G) were modified with subcritical water (SW-G) to effectively regulate their immune activity, and the relationship between polysaccharide chain conformation and immune activity at different subcritical water temperatures was investigated. The results indicated that, compared with HW-G, the xylose and mannose were degraded at high temperatures. The molecular weight of ginger polysaccharide decreased from 1.083 × 106 g/mol to 3.113 × 105 g/mol after subcritical water modification (100-160 °C). The chain conformation transitioned from rigid rod chain to semi-rigid chain and eventually to random coil. The degree of relaxation of the polysaccharide chains showed a continuous increase trend. Additionally, ginger polysaccharide modified by subcritical water at 130 °C was found to promote the proliferation and phagocytosis of 264.7 cells more obviously and signally increase the secretion levels of NO, IL-6, TNF-α and IL-1β. When the subcritical water temperature exceeds 130 °C, the activity of ginger polysaccharide begins to decline rapidly. These findings demonstrate a close correlation between polysaccharide chain conformation and immunomodulatory activity, confirming the feasibility of the subcritical water temperature effect as a means of immune activity regulation, which opens up a new approach to obtaining highly active polysaccharides.

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

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

Identification of intracellular activation mechanism of rhamnogalacturonan-I type polysaccharide purified from Panax ginseng leaves in macrophages and roles of component sugar chains on activity

This study aimed to investigate the mechanisms underlying intracellular signaling pathways in macrophages in relation to the structural features of rhamnogalacturonan (RG) I-type polysaccharide (PGEP-I) purified from Panax ginseng leaves. For this investigation, we used several specific inhibitors and antibodies against mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB), and pattern recognition receptors (PRRs). Furthermore, we investigated the roles of component sugar chains on immunostimulating activity through a sequential enzymatic and chemical degradation steps. We found that PGEP-I effectively induced the phosphorylation of several MAPK- and NF-κB-related proteins, such as p38, cJun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p65. Particularly, immunocytochemistry analysis confirmed the PGEP-I-induced translocation of p65 into the nucleus. Furthermore, the breakdown of PGEP-I side chains and main chain during sequential enzymatic and chemical degradation reduced the PGEP-I-induced macrophage cytokine secretion activity. IL-6, TNF-α, and NO secreted by macrophages are associated with several signaling pathway proteins such as ERK, JNK, and NF-κB and several PRRs such as dectin-1, CD11b, CD14, TLR2, TLR4, and SR. Thus, these findings suggest that PGEP-I exerts potent macrophage-activating effects, which can be attributed to its typical RG-I structure comprising arabinan, type II arabinogalactan, and rhamnose-galacturonic acid repeating units in the main chain.

Comparative Study on the Impact of Different Extraction Technologies on Structural Characteristics, Physicochemical Properties, and Biological Activities of Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruit

Seedless chestnut rose (Rosa sterilis S. D. Shi, RS) is a fresh type of R. roxburghii Tratt with copious functional components in its fruit. Polysaccharides are recognized as one of the vital bioactive compounds in RS fruits, but their antioxidant and hypoglycemic properties have not been extensively explored. Hence, in this study, accelerated solvent extraction (RSP-W), citric acid (RSP-C), 5% sodium hydroxide/0.05% sodium borohydride (RSP-A), and 0.9% sodium chloride (RSP-S) solution extraction were individually utilized to obtain RS fruit polysaccharides. The physicochemical properties, structural characteristics, and biological activities were then compared. Results indicated that extraction methods had significant influences on the extraction yield, uronic acid content, monosaccharide composition, molecular weight, particle size, thermal stability, triple-helical structure, and surface morphology of RSPs apart from the major linkage bands and crystalline characteristics. The bioactivity tests showed that the RSP-S, which had the greatest amount of uronic acid and a comparatively lower molecular weight, exhibited more potent antioxidant and α-glucosidase inhibitory property. Furthermore, all RSPs inhibited α-glucosidase through a mixed-type manner and quenched their fluorescence predominantly via a static quenching mechanism, with RSP-S showing the highest binding efficiency. Our findings provide a theoretical basis for utilizing RSPs as functional ingredients in food industries.

Immunomodulation by xylan and carrageenan-type polysaccharides from red seaweeds: Anti-inflammatory, wound healing, cytoprotective, and anticoagulant activities

The immunomodulatory properties of the polysaccharides (carrageenan, xylan) from Chondrus crispus (CC), Ahnfeltiopsis devoniensis (AD), Sarcodiotheca gaudichaudii (SG) and Palmaria palmata (PP) algal species were studied. Using RAW264.7 macrophages, we investigated the proliferation and migration capacity of different extracts along with their immunomodulatory activities, including nitric oxide (NO) production, phagocytosis, and secretion of pro-inflammatory cytokines. Polysaccharides from C. crispus and S. gaudichaudii effectively mitigated inflammation and improved scratch-wound healing. Polysaccharide fractions extracted under cold conditions (25 °C), including CC-1A, SG-1A and SG-1B stimulated cell proliferation, while fractions extracted under hot conditions (95 °C), including CC-3A, CC-2B and A. devoniensis (AD-3A), inhibited cell proliferation after 48 h. Furthermore, RAW264.7 cells treated with the fractions CC-3A, AD-1A, and SG-2A significantly reduced LPS-stimulated NO secretion over 24 h. Phagocytosis was significantly improved by treatment with C. crispus (CC-2B, CC-3B) and A. devoniensis (AD-3A) fractions. RAW264.7 cells treated with the CC-2A and SG-1A fractions showed elevated TGF-β1 expression without affecting TNF-α expression at 24 h. Polysaccharide fractions of A. devoniensis (ι/κ hybrid carrageenan; AD-2A, AD-3A) showed the highest anti-coagulation activity. CC-2A and SG-1A fractions enhanced various bioactivities, suggesting they are candidates for skin-health applications. The carrageenan fractions (CC-3A: λ-, μ-carrageenan, SG-2A: ν-, ι-carrageenan) tested herein showed great potential for developing anti-inflammatory and upscaled skin-health applications.

Research progress on the structure, derivatives, pharmacological activity, and drug carrier capacity of Chinese yam polysaccharides: A review

Chinese yam is a traditional Chinese medicine that has a long history of medicinal and edible usage in China and is widely utilised in food, medicine, animal husbandry, and other industries. Chinese yam polysaccharides (CYPs) are among the main active components of Chinese yam. In recent decades, CYPs have received considerable attention because of their remarkable biological activities, such as immunomodulatory, antitumour, hypoglycaemic, hypolipidaemic, antioxidative, anti-inflammatory, and bacteriostatic effects. The structure and chemical alterations of polysaccharides are the main factors affecting their biological activities. CYPs are potential drug carriers owing to their excellent biodegradability and biocompatibility. There is a considerable amount of research on CYPs; however, a systematic summary is lacking. This review summarises the structural characteristics, derivative synthesis, biological activities, and their usage as drug carriers, providing a basis for future research, development, and application of CYPs.

Structural Characterization and In Vitro Anti-Inflammatory Activity of Polysaccharides Isolated from the Fruits of Rosa laevigata

RLPa-2 (Mw 15.6 kDa) is a polysaccharide isolated from Rosa laevigata Michx. It consists of arabinose (Ara), galactose (Gal), rhamnose (Rha), glucose (Glc), xylose (Xyl), and galacturonic acid (Gal-UA) with a molar ratio of 1.00:0.91:0.39:0.34:0.25:0.20. Structural characterization was performed by methylation and NMR analysis, which indicated that RLPa-2 might comprise →6)-α-D-Galp-(1→, →4)-α-D-GalpA-(1→, α-L-Araf-(1→, →2,4)-α-D-Glcp-(1→, β-D-Xylp, and α-L-Rhap. In addition, the bioactivity of RLPa-2 was assessed through an in vitro macrophage polarization assay. Compared to positive controls, there was a significant decrease in the expression of M1 macrophage markers (CD80, CD86) and p-STAT3/STAT3 protein. Additionally, there was a down-regulation in the production of pro-inflammatory mediators (NO, IL-6, TNF-α), indicating that M1 macrophage polarization induced with lipopolysaccharide (LPS) and interferon-γ (IFN-γ) stimulation could be inhibited by RLPa-2. These findings demonstrate that the RLPa-2 might be considered as a potential anti-inflammatory drug to reduce inflammation.