Isolation, structures, bioactivities, and utilizations of polysaccharides from Dictyophora species: A review.

Dictyophora species is an edible and medicinal fungus belonging to the Basidiomycotina, Gasteromycetes, Phallales, family Phallaceae, and genus Dictyophora, which is popular with consumers in China and across various Asian regions. Polysaccharides from Dictyophora species (DPs) are important bioactive macromolecules with multiple health benefits, according to published studies, including anti-tumor, antioxidative, anti-obesity, anti-hyperlipidemic, hepatoprotective, immunomodulatory, anti-inflammatory, regulation of gut microbiota, antibacterial, renoprotective, and other pharmacological effects. Based on their rich pharmacological activities, the preparation techniques, structural characteristics and pharmacological activities of DPs have been extensively studied. However, to the best of our knowledge, there is no dedicated review to shed light on recent advances in DPs. Therefore, in order to fill this gap, this review provides a comprehensive overview of the research on DPs, including the latest advances in extraction, isolation and purification, structural characteristics, pharmacological properties, safety assessment and potential utilizations, which will provide a theoretical basis for the research and development of subsequent DPs-related products.

Polysaccharides from Hericium erinaceus and its immunomodulatory effects on RAW 264.7 macrophages.

This study aimed to optimize the extraction of Hericium erinaceus polysaccharides (HEP) using ultrasound-assisted enzymatic extraction combined with Plackett-Burman design (PBD) and response surface methodology (RSM). The optimal extraction conditions were identified as: 33 min extraction time, 30:1 liquid to material ratio, 38 °C extraction temperature, 9 g/kg cellulase amount, pH 4, and 20 % ethanol concentration. Under these conditions, the extraction yield of HEP was 5.87 ± 0.16 %, consistent with the predicted results. Additionally, the potential immunomodulatory activity of HEP on RAW 264.7 macrophage was evaluated. The results revealed that HEP improved the immunostimulatory activity of RAW264.7 cells, evident from increased production of IL-6 and TNF-α. These findings suggest that HEP is capable of enhancing the immune activity of RAW 264.7 macrophage.

Extraction, Purification, Structural Characterization, and Antitumor Effects of Water-Soluble Intracellular Polysaccharide (IPSW-1) from Phellinus igniarius Mycelia.

Phellinus igniarius is a commonly used Chinese medicine fungus, and its polysaccharide is a valuable bioactive with antioxidant, antiaging, antitumor activities, etc. However, their bioactivities are influenced by their structural and physicochemical properties. Hence, this research isolated and purified homogeneous water-soluble intracellular polysaccharide (IPSW-1) from P. igniarius mycelia. A coherent study of its structural characteristics, conformation, and antitumor mechanisms was evaluated. The results showed IPSW-1 has no triple helical conformation according to the Congo red test. Based on FT-IR, periodate oxidation, Smith degradation, methylation analysis, 1H and 13C NMR spectroscopy data, and IPSW-1 consisted of α-d-glucopyranose (Glcp). The backbone of IPSW-1 consisted primarily of repeating three (1 → 6)-linked α-d-Glcp and one (1 → 3,4)-linked α-d-Glcp, with one terminal α-d-Glcp as side chains of 3-O-connected to the main chain for every four residues. The IPSW-1 had an inhibitory influence on HepG2 cell proliferation and inhibited the migration and invasion ability by down-regulating the expression levels of MMP-7 and RhoA. Moreover, IPSW-1 could inhibit the lysis of autophagosomes to inhibit autophagy and regulate mitochondrial membrane potential and pro-apoptotic protein Bax, which causes the caspase cascade to promote apoptosis, thereby inhibiting the role of tumor cells. These findings show IPSW-1 holds potential as an innovative functional food.

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

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

Isolation Techniques, Structural Characteristics, and Pharmacological Effects of Phellinus Polysaccharides: A Review.

Phellinus is a precious perennial medicinal fungus. Its polysaccharides are important bioactive components, and their chemical composition is complex. The polysaccharides are mainly extracted from the fruiting body and mycelium. The yield of the polysaccharides is dependent on the extraction method. They have many pharmacological activities, such as antitumor, immunomodulatory, antioxidant, hypoglycemic, anti-inflammatory, etc. They are also reported to show minor toxic and side effects. Many studies have reported the anticancer activity of Phellinus polysaccharides. This review paper provides a comprehensive examination of the current methodologies for the extraction and purification of Phellinus polysaccharides. Additionally, it delves into the structural characteristics, pharmacological activities, and mechanisms of action of these polysaccharides. The primary aim of this review is to offer a valuable resource for researchers, facilitating further studies on Phellinus polysaccharides and their potential applications.

Characterization and antioxidant properties of three exopolysaccharides produced by the Cyclocarya paliurus endophytic fungus.

In recent years, the considerable potential of endophytic bacteria and fungi as prolific producers of exopolysaccharides (EPSs) have attracted interest. In this study, 56 endophytes were isolated from Cyclocarya paliurus, and the secondary metabolites of EPSs were extracted from Monascus purpureus, Penicillium citrinum and Aspergillus versicolor, screened, and named MPE, PCE and AVE, respectively. In this work, the physicochemical properties and antioxidant activities of three EPSs, their cell proliferation activity on IEC-6 and RAW264.7 were investigated. The three EPSs were mainly composed of neutral sugar and differ in microstructure. However, MPE had a loose structure, and PCE exhibited a dense and sheet-like structure. In addition, the three EPSs performed ordinary antioxidant activity in vitro but showed excellent cell proliferation activity on IEC-6 and RAW264.7. The cell proliferation activity of PCE was 1.4-fold that of the controls at a concentration of 800 µg/mL on IEC-6, and MPE exhibited 1.3-fold increase on RAW264.7. This study provided scientific evidence and insights into the application of endophytes as a novel plant resource possessing huge application potential.

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.

A fungal polysaccharide from Fomitopsis officinalis as a multi-target molecule to combat cancer.

Some macrofungi have a long history of being used as traditional or folk medicines, making significant contributions to human health. To discover bioactive molecules with potential anticancer properties, a homogeneous heteropolysaccharide (FOBP90-1) was purified from the medicinal macrofungus Fomitopsis officinalis. FOBP90-1 was found to have a molecular weight of 2.87 × 104 g/mol and mainly consist of →6)-α-d-Galp-(1→, →2,6)-α-d-Galp-(1→, →3)-α-l-Fucp-(1→, →6)-ß-d-Glcp-(1→, α-d-Manp-(1→, and 3-O-Me-α-l-Fucp-(1→ according to UV, FT-IR, methylation analysis, and NMR data. In addition to its structural properties, FOBP90-1 displayed anticancer activity in zebrafish models. The following mechanistic analysis discovered that the in vivo antitumor effect was linked to immune activation and angiogenesis inhibition. These effects were mediated by the interactions of FOBP90-1 with TLR-2, TLR-4, PD-L1, and VEGFR-2, as determined through a series of experiments involving cells, transgenic zebrafish, molecular docking simulations, and surface plasmon resonance (SPR). All the experimental findings have demonstrated that FOBP90-1, a purified fungal polysaccharide, is expected to be utilized as a cancer treatment agent.

Glucan polysaccharides isolated from Lactarius hatsudake Tanaka mushroom: Structural characterization and in vitro bioactivities.

Commercially available mushroom polysaccharides have found widespread use as adjuvant tumor treatments. However, the bioactivity of polysaccharides in Lactarius hatsudake Tanaka (L. hatsudake), a mushroom with both edible and medicinal uses, remains relatively unexplored. To address this gap, five L. hatsudake polysaccharides with varying molecular weights were isolated, named LHP-1 (898 kDa), LHP-2 (677 kDa), LHP-3 (385 kDa), LHP-4 (20 kDa), and LHP-5 (4.9 kDa). Gas chromatography-mass spectrometry, nuclear magnetic resonance, and atomic force microscopy, etc., were employed to determine their structural characteristics. The results confirmed that spherical aggregates with amorphous flexible fiber chains dominated the conformation of the LHP. LHP-1 and LHP-2 were identified as glucans with α-(1,4)-Glcp as the main chain; LHP-3 and LHP-4 were classified as galactans with varying molecular weights but with α-(1,6)-Galp as the main chain; LHP-5 was a glucan with ß-(1,3)-Glcp as the main chain and ß-(1,6)-Glcp connecting to the side chains. Significant differences were observed in inhibiting tumor cell cytotoxicity and the antioxidant activity of the LHPs, with LHP-5 and LHP-4 identified as the principal bioactive components. These findings provide a theoretical foundation for the valuable use of L. hatsudake and emphasize the potential application of LHPs in therapeutic tumor treatments.

Structural characterization of the polysaccharide from the black crystal region of Inonotus obliquus and its effect on AsPC-1 and SW1990 pancreatic cancer cell apoptosis.

In this study, one water soluble polysaccharide (IOP1-1) with a weight average molecular weight of 6886 Da was obtained from the black crystal region of Inonotus obliquus by hot water extraction, DEAE-52 cellulose extraction and Sephadex-100 column chromatography purification. Structural analysis indicated that IOP1-1 was a glucan with a main chain composed of α-Glcp-(1 â†’ 4)-α-Glcp-(1 â†’ 4)-ß-Glcp-(1 â†’ 4)-ß-Glcp-(1 â†’ 4)-α-Glcp-(1 â†’ 6)-ß-Glcp-(1 â†’ 4)-α-Glcp-(1 â†’ 3)-ß-Glcp-(1→. The CCK-8 assay results showed that IOP1-1 inhibited AsPC-1 and SW1990 pancreatic cancer cell proliferation in a concentration-dependent manner. Flow cytometric analysis revealed that IOP1-1 induced cell cycle arrest in AsPC-1 and SW1990 cells. Hoechst 33342 staining and Annexin V-FITC/PI double staining analysis showed that IOP1-1 could induce apoptosis in AsPC-1 and SW1990 cells. Furthermore, western blot analysis confirmed that IOP1-1 could induce apoptosis in AsPC-1 and SW1990 pancreatic cancer cells through three pathways: the mitochondrial pathway, the death receptor pathway, and endoplasmic reticulum stress. According to these research data, IOP1-1 may be utilized as an adjuvant treatment to anticancer medications, opening up new application prospects and opportunities.

An antitumor fungal polysaccharide from Fomitopsis officinalis by activating immunity and inhibiting angiogenesis.

Macrofungi, a class of unique natural resources, are gaining popularity owing to their potential therapeutic benefits and edibility. From Fomitopsis officinalis, a medicinal macrofungus with anticancer activity, a homogeneous heteropolysaccharide (FOBP50-1) with a molecular weight of 2.21 × 104 g/mol has been extracted and purified. FOBP50-1 was found to be composed of 3-O-methylfucose, fucose, mannose, glucose, and galactose with a ratio of 1: 6.5: 4.4: 8.1: 18.2. The sugar fragments and structure of FOBP50-1 were investigated, which included →6)-α-d-Galp-(1→, →2,6)-α-d-Galp-(1→, →3)-α-l-Fucp-(1→, α-d-Glcp-(1→, →3)-ß-d-Manp-(1→, →6)-ß-d-Manp-(1→, 3-O-Me-α-l-Fucp-(1→, according to the UV, FT-IR, GC-MS, and NMR data. Besides the structure elucidation, FOBP50-1 showed promising antitumor activity in the zebrafish assays. The following mechanism examination discovered that FOBP50-1 interacted with TLR-4, PD-1, and VEGF to activate immunity and inhibit angiogenesis according to a series of cell, transgenic zebrafish, and surface plasmon resonance (SPR) experiments. The KD values indicating the association of FOBP50-1 with TLR-4, PD-1, and VEGF, were 4.69 × 10-5, 7.98 × 10-6, 3.04 × 10-6 M, respectively, in the SPR experiments. All investigations have demonstrated that the homogenous fungal polysaccharide FOBP50-1 has the potential to be turned into a tumor immunotherapy agent.

Characterization and biological activities of polysaccharides extracted from Auricularia auricula with different extraction methods.

Polysaccharides derived from Auricularia auricula exhibit diverse biological activities and hold significant potential for commercial utilization as functional food ingredients. In this investigation, polysaccharides from A. auricula were obtained using six extraction techniques (ammonium oxalate solution extraction, sodium hydroxide solution extraction, hot water extraction, pectinase and cellulase-assisted extraction, ultrasonic-assisted extraction, and microwave-assisted extraction). Subsequently, a comprehensive comparison was conducted to evaluate their physicochemical properties and biological functionalities. The ammonium oxalate solution extraction method yielded a higher extraction rate (11.76%) and polysaccharide content (84.12%), as well as a higher uronic acid content (10.13%). Although the six Auricularia polysaccharides had different molecular weight distributions, monosaccharide molar ratios, similar monosaccharide compositions, and characteristic functional groups of polysaccharides, they exhibited different surface morphology. In vitro assays showed that polysaccharides extracted by ammonium oxalate solution possessed good scavenging ability against DPPH free radical, hydroxyl free radical and superoxide anion free radical as well as reduction power of iron ion. At the same time, both polysaccharides extracted by ammonium oxalate solution and sodium hydroxide solution promoted NO production in mouse macrophages along with the secretion of cytokines TNF-α, IL-1ß, and IL-6. These results indicated significant differences in the structure and characteristics among Auricularia polysaccharides prepared by various extraction methods, which may be related to the variety or origin of A. auricula; furthermore, their bioactivities varied accordingly in vitro assays where the ammonium oxalate solution extraction method was found more beneficial for obtaining high-quality bioactive Auricularia polysaccharides.

Identification and Quantification of Monosaccharides from Fungal Cell Walls and Exopolysaccharides by Gas Chromatography Coupled to Mass Spectrometry.

The fungal cell wall and secreted exopolysaccharides play an important role in the interactions between fungi and their environment. Despite their central role in fungal biology, ecology, and host-pathogen interactions, the composition of these polymers and their synthetic pathways are not well understood. The protocols presented in this article describe an approach to isolate fungal cell wall polysaccharides and to identify and quantify the monosaccharide composition of these polymers by gas chromatography-mass spectrometry (GC-MS). © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: O-methyl trimethylsilyl monosaccharide derivatives composition analysis by GC-MS Support Protocol: Fungal cell wall extraction.

Characterization and immunomodulatory effect of an alkali-extracted galactomannan from Morchella esculenta.

In our continuous exploration for bioactive polysaccharides, a novel polysaccharide FMP-2 was isolated and purified from the fruiting bodies of Morchella esculenta by alkali-assisted extraction. FMP-2 had an average molecular weight of 1.09 × 106 Da and contained mannose, glucuronic acid, glucose, galactose, and arabinose in a molar ratio of 4.10:0.22:1.00:5.75:0.44. The backbone of FMP-2 mainly consisted of 1,2-α-D-Galp, 1,6-α-D-Galp, and 1,4-α-D-Manp, with branches of 1,4,6-α-D-Manp and 1,2,6-α-D-Galp. FMP-2 can stimulate phagocytosis and promote the secretion of NO, ROS, and cytokines like IL-6, IL-1ß, and TNF-α in RAW264.7 cells ranging from 25 to 400 µg/mL. FMP-2 had great repairing effect on the immune injury of zebrafish induced by chloramphenicol. The phagocytosis ability of zebrafish macrophages and the proliferation of neutrophils can be greatly enhanced by polysaccharide FMP-2 with concentrations from 50 to 200 µg/mL. These findings suggest that FMP-2 might be used as a potential immunomodulator in the food and pharmaceutical industries.

Selenium-Containing Exopolysaccharides Isolated from the Culture Medium of Lentinula edodes: Structure and Biological Activity.

In continuation of our research on the influence of selenium incorporation on the biosynthesis, structure, and immunomodulatory and antioxidant activities of polysaccharides of fungal origin, we have isolated from a post-culture medium of Lentinula edodes a selenium (Se)-containing exopolysaccharide fraction composed mainly of a highly branched 1-6-α-mannoprotein of molecular weight 4.5 × 106 Da, with 15% protein component. The structure of this fraction resembled mannoproteins isolated from yeast and other mushroom cultures, but it was characterized by a significantly higher molecular weight. X-ray absorption fine structure spectral analysis in the near edge region (XANES) suggested that selenium in the Se-exopolysaccharide structure was present mainly at the IV oxidation state. The simulation analysis in the EXAFS region suggested the presence of two oxygen atoms in the region surrounding the selenium. On the grounds of our previous studies, we hypothesized that selenium-enriched exopolysaccharides would possess higher biological activity than the non-Se-enriched reference fraction. To perform structure-activity studies, we conducted the same tests of biological activity as for previously obtained mycelial Se-polyglucans. The Se-enriched exopolysaccharide fraction significantly enhanced cell viability when incubated with normal (human umbilical vein endothelial cells (HUVEC)) cells (but this effect was absent for malignant human cervical HeLa cells) and this fraction also protected the cells from oxidative stress conditions. The results of tests on the proliferation of human peripheral blood mononuclear cells suggested a selective immunosuppressive activity, like previously tested Se-polyglucans isolated from L. edodes mycelium. The Se-exopolysaccharide fraction, in concentrations of 10-100 µg/mL, inhibited human T lymphocyte proliferation induced by mitogens, without significant effects on B lymphocytes. As with previously obtained Se-polyglucans, in the currently tested Se-polymannans, the selenium content increased the biological activity. However, the activity of selenium exopolysaccharides in all tests was significantly lower than that of previously tested mycelial isolates, most likely due to a different mode of selenium binding and its higher degree of oxidation.

The chemical structure and immunomodulatory activity of an exopolysaccharide produced by Morchella esculenta under submerged fermentation.

The extracellular polysaccharide of Morchella esculenta cultivated under submerged fermentation was extracted. A single polysaccharide was purified through DEAE-Cellulose 52 and Sephadex G 100, and named as MEP 2a. The molecular weight of MEP 2a was determined by HPGPC and it is about 1391.5 kDa. MEP 2a is composed of mannose and glucose as the monosaccharide unit with a molar ratio of 8.15 : 1.07. The main polysaccharide chemical structure was analyzed by 1D and 2D NMR. Methylation and NMR analysis revealed that the backbone of MEP 2a consists of 1,3,4-linked-Manp, 1,2-linked-Manp and 1,6-linked-Glcp. 1D and 2D NMR results indicated that the main chain is based on →1)-ß-D-Glcp-(6→, →1)-α-D-Manp-(3,4→, →1)-α-D-Manp-(2→) and the branch chain is composed of α-D-Manp-(1→, →1)-ß-D-Glcp-(6→ and α-D-Glcp-(1→). MEP 2a promoted the phagocytosis function and secretion of NO, IL-1ß, IL-6 and TNF-α of macrophages. In the present study, the chemical structure and immunomodulatory ability of an extracellular polysaccharide of Morchella esculenta was investigated which guarantees further research studies and promising applications.

Structural characteristics, anti-proliferative and immunomodulatory activities of a purified polysaccharide from Lactarius volemus Fr.

Lactarius volemus Fr. is an edible mushroom widely consumed in China. Polysaccharide is an important nutritional component of L. volemus. This research aimed to isolate the polysaccharide from L. volemus and study its structure and bioactivities. A purified polysaccharide was identified and named as LVF-I whose primary structure was proposed considering the comprehensive results of monosaccharide composition, periodate oxidation-smith degradation, methylation analysis, FT-IR and 1D/2D NMR spectroscopy. Then the immunomodulation of LVF-I and its inhibition effect on H1299 and MCF-7 cells were investigated. Results showed that LVF-I (12,894 Da) contained fucose, mannose, glucose and galactose. It had a backbone consisting of →4)-α-D-Glcp-(1→, →6)-ß-D-Manp-(1→, →6)-α-D-Galp-(1 â†’ and →4)-ß-D-Manp-(1→. And its side chains were branched at C2 of →4)-ß-D-Manp-(1 â†’ by →6)-α-D-Galp-(1→, α-D-Glcp-(1→, α-D-Galp-(1 â†’ and α-L-Fucp-(1→. LVF-I (250-1000 µg/mL) could inhibit the proliferation of H1299 and MCF-7 cells, while enhance the proliferative response of splenocyte and the phagocytic ability of RAW264.7. Furthermore, LVF-I (250-1000 µg/mL) significantly induced the secretion of nitric oxide, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) by up-regulating their mRNA expression in macrophages. These results suggested that LVF-I had the potential to be developed as antitumor or immunomodulatory agents by inhibiting the proliferation of tumor cells and stimulating macrophages-mediated immune responses.

Heteropolysaccharides from S. cerevisiae show anti-adhesive properties against E. coli associated with Crohn's disease.

The Saccharomyces cerevisiae CNCM I-3856 was previously reported to strongly inhibit adherent-invasive Escherichia coli (AIEC) adhesion to intestinal epithelial cells in vitro and to favor AIEC elimination from the gut in a murine model of Crohn's disease in vivo. In order to identify which cell wall components of yeast are responsible for AIEC elimination, constituent polysaccharides of yeast were isolated and their anti-adhesive ability against AIEC adhesion in vitro was screened. A fraction containing mannan, ß-glucan and α-glucan extracted from yeast cell-walls was shown to inhibit 95% of AIEC adhesion in vitro and was thus identified as the strongest anti-adhesive yeast cell wall component. Furthermore, this mannan-glucan-containing fraction was shown to accelerate AIEC decolonization from gut in vivo. This fraction could be proposed as a treatment to eliminate AIEC bacteria in patients with Crohn's disease, a microbial trigger of intestinal inflammation.

Characteristics and antifatigue activity of graded polysaccharides from Ganoderma lucidum separated by cascade membrane technology.

In this paper, cascade membrane technology was utilized to classify polysaccharides from Ganoderma lucidum (GLPs). The properties and antifatigue activity of graded polysaccharides were identified and compared. GLPs were separated using cascade ultrafiltration membranes of 100 kDa, 10 kDa and 1 kDa in sequence. The molecular weights of polysaccharides in these GLP fractions were approximately 322.0 kDa, 18.8 kDa and 6.4 kDa, and all polysaccharides were in active ß-configurations. This showed that all graded GLPs could elongate swimming time, improve endurance and promote fatigue recovery, especially polysaccharides with molecular weights above 10 kDa. This demonstrated that GLPs could decrease the activities of SUN and CK and the levels of MDA and BLA. They also increased the level of Gly, accelerated fat transformation, and improved the activities of GPx, SOD and LDH in all treated mice. Accordingly, GLPs above 10 kDa might be potential agents with antifatigue activity.

The lipid lowering and antioxidative stress potential of polysaccharide from Auricularia auricula prepared by enzymatic method.

An efficient extraction method of Auricularia auricula polysaccharides (AAPs) by neutral protease was developed and optimized by response surface methodology. AAPs were graded by stepwise ethanol precipitation, the fraction with high recovery rate and strong radical scavenging rate were obtained, then its antioxidant and lipid lowering effect were studied using Caenorhabditis elegans as model organism. The extract yield and ABTS+ scavenging rates of AAPs could reach 14.90% and 86.0% at 50 °C, 75 mL/g of liquid-to-material ratio and pH 9.0. AAP3 obtained by 15% ethanol was a heteropolysaccharide comprised of mannose, glucose, glucuronic acid, xylose, galactose and glucosamine. AAP3 could significantly prolong the lifespan of C. elegans and enhance the activity of antioxidant enzymes including superoxide dismutase (SOD), catalases (CAT) at 0.25 mg/mL (p < 0.05). The qRT-PCR results showed that AAP3 could up regulate mRNA expression levels of daf-16 and skn-1 (>1.6 fold) at 0.25 mg/mL. Besides, AAP3 could significantly reduce the level of body fat and triglyceride in C. elegans (p < 0.05). These studies demonstrated that A. auricula polysaccharides prepared by neutral protease had a prominent protective effect to the damage induced by the intracellular free radical generating agents.