Structure characterization and biological activities evaluation of two hetero-polysaccharides from Lepista nuda: Cell antioxidant, anticancer and immune-modulatory activities

Structural characterization and immunomodulatory activity of an exopolysaccharide isolated from Bifidobacterium adolescentis

Bifidobacterium adolescentis is a key probiotic that has been proven to possess various bioactivities. A water-soluble heteropolysaccharide (BEP-1A) was isolated from the probiotic and systematically investigated for the first time. The molecular weight of BEP-1A was calculated to be 9.69 × 106 Da. Combined with monosaccharide composition, Fourier transform infrared (FT-IR) spectroscopy, methylation and nuclear magnetic resonance (NMR) analysis, BEP-1A was composed of mannose, glucose and galactose at a molar ratio of 0.11⁚4.30⁚1.32. The backbone included β-1,2-Glcp, β-1,3-Glcp, α-1,4-Glcp, α-1,4-Galp, α-1,6-Galp and α-1,3-Manp, with the branch at the O-2 position of α-1,6-Galp, consisting of α-1,2-Galp and α-1-Glcp. Moreover, a filamentous structure of BEP-1A was detected by scanning electron microscopy (SEM). BEP-1A presented high thermal stability based on thermogravimetric analysis (TGA). X-ray diffractometry (XRD) results revealed that BEP-1A was an amorphous molecule without a crystal structure. Furthermore, BEP-1A significantly increased the viability of RAW 264.7 macrophages, improved phagocytosis, and promoted the secretion of nitric oxide (NO), reactive oxygen species (ROS), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS). BEP-1A was also found to induce the nuclear translocation of the NF-κB subunit p65 and upregulate the phosphorylation of p65 and IκB-α, which suggested that the NF-κB pathway was involved in the BEP-1A-induced immunomodulatory effect. Overall, this study provides a theoretical basis for the development of BEP-1A as an immunomodulator in pharmaceuticals and functional foods.

Structural characteristics and anti-tumor activity of alkali-extracted acidic polysaccharide extracted from Panax ginseng

In this paper, Panax ginseng residue after boiling water extraction was reused to obtain the acidic polysaccharide PGP-1, and its structural characterization and anti-tumor activity were investigated. Structural experiments showed that PGP-1 consisted of Rha, Ara, Glc, Gal, and GalA in a molar ratio of 0.04:0.31:1.00:0.28:0.54. The backbone of PGP-1 was formed by the 1 → 4 glycosidic linkage of HG and RG-I, with Araf, Glcp, and Galp sidechains attached at position O-3. In vitro experiments showed that PGP-1 induced apoptosis in MGC803 cells through the mitochondrial pathway, with apoptotic features such as nuclear consolidation and generation of apoptotic vesicles. Animal experiments showed that PGP-1 could inhibit the proliferation of tumor cells in H22 tumor-bearing mice by improving the status of immune organs, enhancing the activity of immune cells, and increasing the levels of serum cytokines and apoptosis-related proteins, with the tumor inhibition rate reaching 45.70 % (200 mg/kg). The above experimental results indicated that Panax ginseng polysaccharides had the potential to be functional anti-tumor agents.

Neutral oligosaccharides from ginseng (Panax ginseng) residues vs. neutral ginseng polysaccharides: A comparative study of structure elucidation and biological activity

This study aimed to compare the structural and biological activities of neutral ginseng residue oligosaccharides (GRO-N) and neutral ginseng polysaccharides (GP-N). Their structures of GRO-N and GP-N were established based on their molecular weight (Mw), monosaccharide composition, Fourier-transform infrared spectroscopy, methylation, and nuclear magnetic resonance analyses. The Mws of GRO-N and GP-N were 1121.0 Da and 12,791.0 Da, respectively. Both had major chain structures comprising α-D-Glcp-(1→, →4)-α-D-Glcp-(1→, and →4)-α/β-D-Glcp, with branch points at →4,6)-α-D-Glcp-(1→. Moreover, the branched chain of GRO-N was α-D-Glcp-(1→ and →6)-α-D-Glcp-(1→. The branched chain of GP-N was α-D-Glcp-(1→ and →4)-α-D-Glcp-(1→. GRO-N, with a lower Mw and more diverse glycosidic bonds, exhibited higher antioxidant, hypoglycemic, and immune activities than GP-N. Cell viability peaked (202.81 ± 4.80 %) at a GRO-N concentration of 200 μg/mL. These findings provide a theoretical basis for further utilization of ginseng residual saccharides.

The structure elucidation and alleviating effect on liver fibrosis in vivo of a pectin-like polysaccharide isolated from Buddleja officinalis

Buddleja officinalis has been used as a traditional Chinese medicine for years. Although evidence has demonstrated it can enhance liver function, the active material basis remains unknown. We hypothesize polysaccharides from Buddleja officinalis may be the active material against liver disease. Herein, we elucidated the structure of a novel pectin-like polysaccharide designed BOM0.05S2 with a molecular weight of 13.6 kDa. Combined with endo-1, 4-β-Mannanase degradation, we found its backbone consists of alternate 1, 2, 4-linked α-Rhap and 1, 4-linked α-GalpA (RG-I type pectin) and mannoglucan, with branches of 1, 4-, 1, 6- and 1, 3, 6-linked β-Galp, T-, 1, 5- and 1, 3, 5-linked α-Araf, T-linked β-Manp and T-linked α-Glcp substituted at C-4 of 1, 2, 4-linked α-Rhap and C-6 of 1, 4, 6-linked α-Glcp. As speculated, BOM0.05S2 showed a significant improvement on carbon tetrachloride (CCl4)-induced liver damage in mice. Bioactivity test showed that BOM0.05S2 reduced AST, ALT and four indexes of liver fibrosis including LN, HA, IV-C, PC-III. Further, we demonstrated that BOM0.05S2 attenuated the collagenous fiber and α-SMA in liver. These findings highlight the potential of BOM0.05S2 as a lead compound for the treatment of liver fibrosis.

Structural characteristics and anti-photoaging effect of Pyracantha fortuneana fruit polysaccharides in vitro and in vivo

Pyracantha fortuneana is a cultivated pant extensively cultivated worldwide for its ornamental value and ecological benefits. In this study, a polysaccharide with anti-photoaging activity was extracted and purified from P. fortuneana fruit (PPFP). The structural constitution of PPFP was elucidated by molecular weight determination, FT-IR, monosaccharide composition analysis, smith degradation, methylation, and NMR spectroscopy. The results revealed that PPFP is a macromolecular polysaccharide with a weight-average molecular weight of 70,895 Da. The PPFP is predominantly characterized by →3,6)-β-Galp-(1→, →5,3)-α-Araf-(1 → and →4,2)-α-Xylp-(1→, →4)-β-Galp-(1 → and →4)-β-GalpA-(1 → glycosidic linkages, with t-α-Araf-(1 → and t-α-Glcp-(1 → terminal units. The anti-photoaging activity and potential mechanism of action of PPFP was investigated in vitro and in vivo. Results showed that PPFP exerted anti-photoaging effect on UVB-damaged HaCaT cells by ameliorating cell apoptosis, regulating the mitochondrial membrane potential and oxidative stress level, alleviating the phosphorylation level of the proteins in MAPK pathways, and repairing the expression of tight junction proteins. Moreover, PPFP enhanced the lifespan and diminished the oxidative stress in UVB-injured Caenorhabditis elegans. Collectively, this study comprehensively elucidates the anti-photodamaging potential of P. fortuneana fruit polysaccharide and offers a novel plant-derived adjuvant therapy for the treating photodamage.

Structure characterization and immunoactivity on dendritic cells of two neutral polysaccharides from Dictyophora rubrovalvata

Dictyophora rubrovalvata is a valuable fungus homologous to food and medicine, and its polysaccharide have been gaining increasing attention because of its plentiful activity. However, the structure and activity of its homogeneous polysaccharide have not been studied enough. In this study, two polysaccharides DRP-I and DRP-II were purified from D. rubrovalvata. Their structures were characterized by chemical composition, monosaccharide composition analysis, methylation analysis and nuclear magnetic resonance spectroscopy. The results showed that DRP-I and DRP-II were neutral heteropolysaccharides with molecular weights of 5.79 × 103 and 1.25 × 104 Da, respectively, which were composed of mannose, galactose, glucose, xylose and fucose. The main chains were → 6)-α-D-Galp-(1 → 6)-α-D-Galp-(2,1 → 6)-α-D-Manp-(2,1 → 6)-α-D-Galp-(1, and branch chains were β-D-Xylp-(1 → 3)-α-L-Fucp-(1 → 4)-α-D-Manp-(1 → and α-D-Galp-(1 → 3)-α-D-Galp-(1 → . The in vitro immunoactivity assays on dendritic cells showed that DRP-I and DRP-II could up-regulate the expression of IL-10 and IL-6 and inhibit the expression of TNF-α in a concentration-dependent manner. This research indicated that DRP-I and DRP-II possessed immunoactivity by balancing the excessive inflammation, and molecular weight is an important factor affecting immunoactivity.

A polysaccharide PRCP from Rosa cymosa Tratt fruit: Structural characteristics and immunomodulatory effects via MAPK pathway modulation in vitro

The Rosa cymosa Tratt, an herbal plant from the Rosaceae family, has historically been valued in China for its medicinal and edible properties. In this study, a novel polysaccharide from R. cymosa fruit, termed PRCP (purified R. cymosa polysaccharide), was isolated using water extraction, decolorization, deproteinization, and ion-exchange chromatography. The structural characteristics of PRCP were investigated using monosaccharide composition analysis, methylation, GPC, FTIR, CD, and NMR spectroscopy. The immunomodulatory effect and potential mechanism of PRCP were evaluated in vitro using a macrophage cell model. Results indicated that PRCP (37.28 kDa) is a highly branched polysaccharide (72.61 %) primarily composed of arabinogalactan, rhamnogalacturonan, and galactoglucan domains with 13 types of glycosidic linkage fragments. Furthermore, PRCP appears to modulate immunomodulatory effects by influencing the phosphorylation of P38 and JNK proteins in the MAPK pathway. Collectively, these findings highlight the potential of PRCP as a promising natural functional food ingredient for immunostimulation.

Isolation, structural characterization and immunomodulatory activity on RAW264.7 cells of a novel exopolysaccharide of Dictyophora rubrovalvata

Fungal polysaccharides have been explored by many for both structural studies and biological activities, but few studies have been done on the extracellular polysaccharides of Dictyophora rubrovalvata, so a new exopolysaccharide was isolated from Dictyophora rubrovalvata and its structure and its immunological activity were investigated. The crude exopolysaccharide (EPS) was purified by DEAE52 cellulose and Sephadex G-200 to obtain a new acidic polysaccharide (DR-EPS). DR-EPS (2.66 × 103 kDa) was consisted mainly of mannose, glucose, galactose and glucuronic acid with a molar ratio of 1: 0.86: 0.20: 0.01. In addition, DR-EPS increased the phagocytic activity of RAW264.7 cells up to 2.67 times of the blank control group. DR-EPS improved intracellular nucleic acid and glycogen metabolism as observed by AO and PAS staining. DR-EPS(40 μg/mL) promoted NO production up to 30.66 μmol, enhanced acid phosphatase (ACP) and superoxide dismutase (SOD) activities, with activity maxima of 660 U/gprot and 96.27 U/mgprot, respectively, and DR-EPS (160 μg / mL) significantly increased the lysozyme content as 2.73 times of the control group. The good immunological activity of extracellular polysaccharides of Dictyophora rubrovalvata provides directions for the use of fermentation broths.

Polysaccharide from Boletus aereus ameliorates DSS-induced colitis in mice by regulating the MANF/MUC2 signaling and gut microbiota

Inflammatory bowel diseases (IBD) are chronic inflammatory conditions characterized by disruptions in the colonic mucus barrier and gut microbiota. In this study, a novel soluble polysaccharide obtained from Boletus aereus (BAP) through water extraction was examined for its structure. The protective effects of BAP on colitis were investigated using a DSS-induced mice model. BAP was found to promote the expression of intestinal mucosal and tight junction proteins, restore the compromised mucus barrier, and suppress the activation of inflammatory signaling. Moreover, BAP reshape the gut microbiota and had a positive impact on the composition of the gut microbiota by reducing inflammation-related microbes. Additionally, BAP decreased cytokine levels through the MANF-BATF2 signaling pathway. Correlation analysis revealed that MANF was negatively correlated with the DAI and the level of cytokines. Furthermore, the depletion of gut microbiota using antibiotic partially inhabited the effect of BAP on the activation of MANF and Muc2, indicating the role of gut microbiota in its protective effect against colitis. In conclusion, BAP had an obvious activation on MANF under gut inflammation. This provides new insights into the prospective use of BAP as a functional food to enhance intestinal health.

Attenuation effect of a polysaccharide from large leaf yellow tea by activating autophagy

Chemotherapy, the most common class of anticancer drugs, is considerably limited owing to its adverse side effects. In this study, we aimed to evaluate the protective effect and mechanism of action of large-leaf yellow tea polysaccharides (ULYTP-1, 1.29 × 104 Da) against chemotherapeutic 5-fluorouracil (5-Fu). Structural characterisation revealed that ULYTP-1 was a β-galactopyranouronic acid. Furthermore, ULYTP-1 promoted autolysosome formation, activating autophagy and reducing the oxidative stress and inflammation caused by 5-Fu. Our in vivo study of 4 T1 tumour-bearing mice revealed that ULYTP-1 also attenuated 5-Fu toxicity through modulation of the gut microbiota. Moreover, ULYTP-1 effectively protected immune organs and the liver from 5-Fu toxicity, while promoting its tumour-inhibitory properties. The current findings provide a new strategy for optimising chemotherapy regimens in the clinic.

Fungi-derived natural antioxidants

In humans, exogenous antioxidants aid the endogenous antioxidant system to detoxify excess ROS generated during oxidative stress, thereby protecting the body against various diseases and stressful conditions. The majority of natural antioxidants available on the consumer market are plant-based; however, fungi are being recognized as alternative sources of various natural antioxidants such as polysaccharides, pigments, peptides, sterols, phenolics, alkaloids, and flavonoids. In addition, some exogenous antioxidants are exclusively found in fungi. Fungi-derived antioxidants exhibit scavenging activities against DPPH, ABTS, hydroxyl, superoxide, hydrogen peroxide, and nitric oxide radicals in vitro. Furthermore, in vivo models, application of fungal-derived antioxidants increase the level of various antioxidant enzymes, such as catalases, superoxide dismutases, and glutathione peroxidases, and reduce the level of malondialdehyde. Therefore, fungi-derived antioxidants have potential to be used in the food, cosmetic, and pharmaceutical industries. This review summarizes the antioxidant potential of different fungi (mushrooms, yeasts, and molds)-derived natural compounds such as polysaccharides, pigments, peptides, ergothioneine, ergosterol, phenolics, alkaloids, etc.

Polyamines in Edible and Medicinal Fungi from Serbia: A Novel Perspective on Neuroprotective Properties

The therapeutic effectiveness of current neurodegenerative disease treatments is still under debate because of problems with bioavailability and a range of side effects. Fungi, which are increasingly recognized as sources of natural antioxidants and acetylcholinesterase (AChE) enzyme inhibitors, may thus serve as potent neuroprotective agents. Previous studies have associated the anti-AChE and antioxidant activities of fungi mostly with polysaccharides and phenolic compounds, while other secondary metabolites such as polyamines (PAs) have been neglected. This study aimed to investigate eight edible and medicinal fungi from Serbia, marking the initial investigation into the neuroprotective capabilities of Postia caesia, Clitocybe odora, Clitopilus prunulus, and Morchella elata. Neuroprotective activity was examined using the Ellman assay, while the antioxidant capacity was tested by conducting DPPH, NO, ABTS, and FRAP tests. PA levels were determined by high-performance liquid chromatography (HPLC) coupled with fluorescent detection. Ganoderma applanatum and Lepista nuda exhibited the most robust anti-AChE (98.05 ± 0.83% and 99.94 ± 3.10%, respectively) and antioxidant activities, attributed to the synergistic effects of the total protein, total phenolic, and PA levels. Furthermore, P. caesia displayed significant AChE inhibition (88.21 ± 4.76%), primarily linked to the elevated spermidine (SPD) (62.98 ± 3.19 mg/kg d.w.) and putrescine (PUT) levels (55.87 ± 3.16 mg/kg d.w.). Our results highlight the need for thorough research to comprehend the intricate relationships between distinct fungus species and AChE inhibition. However, it is important to recognize that more research is required to identify the precise substances causing the reported inhibitory effects.

Antitumor Activity of Carboxymethyl Pachymaran with Different Molecular Weights Based on Immunomodulatory and Gut Microbiota

Carboxymethyl pachymaran (CMP) was treated via high-temperature and cellulase hydrolysis to obtain HTCMP, HTEC-24, and HTEC-48. The chemical structure and in vivo antitumor activities of the four types of CMPs were investigated. Compared with CMP (787.9 kDa), the molecular weights of HTCMP, HTEC-24, and HTEC-48 were decreased to 429.8, 129.9, and 68.6 kDa, respectively. The viscosities and particle sizes of the CMPs could also decrease with the decline in the molecular weights. All the CMPs showed antitumor abilities, but HTEC-24 exhibited the best activity. In the animal study, when curing the spleen and thymus, CMPs displayed immunomodulatory effects by increasing the secretion of IFN-γ and IL2 in mice. The CMPs also exerted an antitumor ability by regulating the gut microbiota in tumor-bearing mice. Our results established a foundation to develop an antitumor drug with CMP.

Poria cocos polysaccharide improves intestinal barrier function and maintains intestinal homeostasis in mice

The function of the intestinal tract is critical to human health. Poria cocos is a widely used functional edible fungus in Asia and has been reported to modulate gastrointestinal function. However, the effects of polysaccharides, the main active constituents of Poria cocos, on the intestinal tract remains unclear and is the focus of the study. Poria cocos polysaccharides (PCP) were extracted, characterized, and administered to mice by gavage. The results show that PCP used in this study has a typical polysaccharide peak with a molecular weight of 11.583 kDa and is composed primarily of mannose, D-glucosamine hydrochloride, glucose, galactose, and fucose with a molar ratio of 15.308: 0.967: 28.723: 31.631: 23.371. The methylation results suggest that the PCP backbone may be t-Gal(p), 6-Gal(p) and 2,6-Gal(p). The effects of PCP on the mucosal barrier function of the mouse intestine (duodenum, jejunum, and ileum) were examined in terms of intestinal physiological status, physical barrier, biochemical barrier, immune barrier, and microbial barrier. The results showed that PCP significantly improved the physiological state of mouse intestine. Moreover, PCP strengthened the intestinal physical barrier by upregulating the expression of intestinal Occludin and ZO-1 and downregulating the levels of serum endotoxin, DAO, D-lactate, and intestinal MPO. Regarding biochemical barrier, PCP could upregulate the expression of MUC2, β-defensin, and SIgA in intestinal tissues. In addition, PCP modulated the immune barrier by increasing IL-2, IL-4, IL-6, IL-10, TGF-β, and IFN-γ expression. Besides, PCP increased the level of SCFAs in small intestinal contents. PCP modulates intestinal barrier function by altering the microbial composition of the gut. We also found that PCP could maintain intestinal barrier function by increasing the expression of Wnt/β-Catenin and Lrp5 proteins. Generally, our findings suggested that PCP may be used as a functional food to regulate intestinal mucosal function, thereby enhancing the health of the intestinal and host.