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Structural properties, bioactivities, structure-activity relationships and bio-applications of polysaccharides from Auricularia auricula: A review
... Therefore, PPP may effectively remove free radicals in the body and reduce oxidative stress, and it may prevent and treat diseases related to oxidative stress. Hence, PPP could be used as a health food additive to provide many health benefits, such as enhancing immunity and reducing fatigue and aging [32,53,54]. ...
The selection and breeding of high-quality wild edible fungal strains can bring significant economic and social benefits. A wild fungal strain (X21185) from the Tibetan Plateau was isolated and identified as a novel Pleurotus pulmonarius (P. pulmonarius) based on its morphological and molecular characteristics. The appropriate culture conditions for P. pulmonarius were determined. The nutrient contents of P. pulmonarius fruiting bodies were analyzed. Compared with the conventional nutritional contents of the representative edible fungi (Pleurotus ostreatu and Pleurotus eryngii) and egg, the protein, ash, and dietary fiber contents of P. pulmonarius were higher. Four types of essential amino acids, seven types of nonessential amino acids, the total essential and nonessential amino acids of P. pulmonarius were present in considerably higher quantities than those of representative edible fungi (Pleurotus ostreatus and Pleurotus citrinopileatus) and egg, respectively. P. pulmonarius polysaccharides (PPPs) had strong ABTS⁺, DPPH, and hydroxyl free radical scavenging activities (EC50: 0.051, 3.322, and 2.87 mg/mL, respectively), and the cytotoxicity was higher against HepG2 hepatocellular carcinoma cells (IC50: 1.501 mg/mL) than against MDA-MB-468 triple-negative breast cancer cells (IC50: 2.183 mg/mL). This study provides a foundation for the development of the novel wild P. pulmonarius strain.
... Previous studies showed that the glycosidic bond types, chain structure and the position of the functional groups in the polysaccharides are closely related to their bioactivity (Tang et al., 2024). At present, the role of seaweed polysaccharides in regulating mitochondrial dysfunction and their structural characteristics have been reported, but the relationship between the two is still unknown. ...
Seaweed polysaccharides are naturally occurring macromolecules in seaweeds with a variety of health benefits. Their multiple health benefits are attributed to their regulatory effects on mitochondrial function. However, the relationship between the source of seaweed polysaccharides, polysaccharide properties, and mitochondrial dysfunction has not been comprehensively reviewed. This review summarizes the sources of seaweed polysaccharides, effects of polysaccharide properties (including molecular weight, monosaccharide composition, chemical structure, and functional groups) on regulating mitochondrial function, as well as their main potential regulatory mechanisms (including mitochondrial respiratory chain, mitochondrial membrane structural integrity, mitochondrial DNA, mitochondrial dynamic, mitochondrial autophagy, and mitochondrial Ca²⁺ homeostasis), with the aim to provide a theoretical reference to promote further research on the development and application of seaweed polysaccharides.
... Finally, the Mw of polysaccharides is one of the important influential indicators of their biological activity [51]. Polysaccharides exhibiting lower Mw display reduced viscosity and enhanced solubility, whereas those with high Mw can hinder interactions with cellular receptors due to elevated viscosity or chain entanglement, resulting in diminished bioactivity [52]. Therefore, it is crucial to prepare BCPs with appropriate Mws, and the GEP method is precisely a good way to obtain polysaccharides with different Mw fragments. ...
Given that the preparation method of polysaccharides affects the functional properties, four types of acidic polysaccharides (BCP30-1a, BCP50-1a, BCP70-1a, and BCP90-1a) were prepared using the gradient ethanol precipitation method. Then, a series of chemical and instrumental analysis techniques were used to compare structural characteristics and morphology. Neuroprotective effects were explored using OGD/R-induced PC12 cells. The results showed that BCP30-1a, BCP50-1a, BCP70-1a, and BCP90-1a had similar characteristic groups and contained both β-glycosidic and α-glycosidic bonds. Their molecular weights, in descending order, were 198.398 kDa, 184.690 kDa, 184.556 kDa, and 184.217 kDa, respectively. In addition, the four polysaccharides contained different proportions of glycosidic bonds, namely, Manp-(1→, →5)-Araf-(1→, →3)-Galp (or GalAp)-(1→, →4)-Glcp-(1→ and →3,6)-Galp-(1→. BCP30-1a also contained a certain proportion of Galp-(1→, and each polysaccharide had different microscopic characteristics and good thermal stability. Finally, BCP50-1a, BCP70-1a, and BCP90-1a exhibited good cytoprotective effects on PC12 cells based on the OGD/R model. These findings provide a novel regulatory strategy for the functional activity of BCPs and offer scientific evidence supporting application in the research field of ischemic stroke.
Glycoproteins are special proteins and important nutrients for hypoglycemic activity. However, the structure of Auricularia Auricula glycoprotein (AAG) and the stability of its hypoglycemic activity during simulated digestion (including saliva, gastral and intestine digestion) in vitro are still unknown. In this study, AAG-3 was isolated from Auricularia Auricula. SDS-PAGE, UV spectrum, FTIR, amino acid composition, dichroic spectrum and SEM were used to characterize its structure. The hypoglycemic activity of AAG-3 during in vitro digestion was investigated via inhibition of α-amylase and α-glucosidase activities, as well as glucose consumption, glycogen content and related enzyme activity in insulin-resistant HepG2 cells. Structural characterization showed that AAG-3 with a Mw of 18.21 kDa had an O-type glycopeptide bond and typical functional groups of glycoproteins. AAG-3 contained 18 kinds of amino acid and many α-helixes and β-turns, and its microstructure was sheet-like. With the simulated digestion of AAG-3 in vitro, the inhibition of α-amylase and α-glucosidase activity as well as the glucose consumption, glycogen content and HK and PK enzyme activities in insulin-resistant HepG2 cells were significantly increased. Therefore, AAG-3 has a potential role in reducing blood glucose levels and improving insulin resistance and can be used as a potential micronutritional supplement for diabetic patients.
β-glucans are widely known for their biological activities. However, the choice of extraction method can significantly influence their structural characteristics, thereby potentially impacting their biological functions. In this paper, three fractions of β-glucans were obtained from Candida lusitaniae yeast via alkali and hot-water extraction methods and were analyzed using solid-state ¹³C nuclear magnetic resonance (NMR) spectroscopy. Solid-state NMR spectroscopy was used as a nondestructive technique that preserves the structure of the analyzed molecules. The results suggest that differences in the β-glucan structure are affected by the choice of extraction method. The main difference occurred in the 82–92 ppm region with signal presence suggesting that β-glucans have a linear structure when hot-water-extracted, which is absent in alkali-extracted fractions resulting in the acquisition of β-glucans with an ordered, possibly helical structure. A hot-water extracted water-insoluble (HWN) fraction consists of linear β-1,3-glucans with other signals indicating the presence of β-1,6-linked side chains, chitin and small amounts of α-glucan impurities. For those that are alkali-extracted, alkali-insoluble (AN) and water-soluble (AWS) fractions are structurally similar and consist of an ordered β-1,3-glucan structure with β-1,6-linked side chains and a significant amount of α-glucan and chitin in both fractions.
Introduction:
Auricularia auricula is a well-known traditional edible and medical fungus with high nutritional and pharmacological values, as well as metabolic and immunoregulatory properties. Nondigestible fermentable polysaccharides are identified as primary bioactive constituents of Auricularia auricula extracts. However, the exact mechanisms underlying the effects of Auricularia auricula polysaccharides (AAP) on obesity and related metabolic endpoints, including the role of the gut microbiota, remain insufficiently understood.
Methods:
The effects of AAP on obesity were assessed within high-fat diet (HFD)-based mice through obesity trait analysis and metabolomic profiling. To determine the mechanistic role of the gut microbiota in observed anti-obesogenic effects AAP, faecal microbiota transplantation (FMT) and pseudo-germ-free mice model treated with antibiotics were also applied, together with 16S rRNA genomic-derived taxonomic profiling.
Results:
High-fat diet (HFD) murine exposure to AAP thwarted weight gains, reduced fat depositing and enhanced glucose tolerance, together with upregulating thermogenesis proteomic biomarkers within adipose tissue. Serum metabolome indicated these effects were associated with changes in fatty acid metabolism. Intestine-dwelling microbial population assessments discovered that AAP selectively enhanced Papillibacter cinnamivorans, a commensal bacterium with reduced presence in HFD mice. Notably, HFD mice treated with oral formulations of P. cinnamivorans attenuated obesity, which was linked to decreased intestinal lipid transportation and hepatic thermogenesis. Mechanistically, it was demonstrated that P. cinnamivorans regulated intestinal lipids metabolism and liver thermogenesis by reducing the proinflammatory response and gut permeability in a JAK-STAT signaling-related manner.
Conclusion:
Datasets from the present study show that AAP thwarted dietary-driven obesity and metabolism-based disorders by regulating intestinal lipid transportation, a mechanism that is dependent on the gut commensal P. cinnamivorans. These results indicated AAP and P. cinnamivorans as newly identified pre- and probiotics that could serve as novel therapeutics against obesity.
Background
Mushrooms are considered as next-generation healthy food components. Owing to their low-fat content, high-quality proteins, dietary fiber, and rich source of nutraceuticals. They are ideally preferred in formulation of low-caloric functional foods. In this view, the breeding strategies of mushroom Auricularia cornea (A. cornea) focusing on high yield and higher quality with rich nutritional values and health benefits are still needed.
Materials and methods
A total of 50 strains of A. cornea were used to analyze the bio efficiency and the time required for fruiting body formation following the cultivation experiment. The calorimetric method was used to evaluate the antioxidant activity and quantify the crude polysaccharides and minerals content thereafter.
Results
The results showed that the time required for fruiting body formation and biological efficiency varied significantly among the selected strains. Noticeably, the wild domesticated strain Ac13 of A. cornea mushroom showed the shortest fruit development time (80 days). Similarly, the hybrid strains including Ac3 and Ac15 possessed the highest biological efficiency (82.40 and 94.84%). Hybrid strains Ac18 (15.2%) and cultivated strains Ac33 (15.6%) showed the highest content of crude polysaccharides, while cultivated strains Ac1 and Ac33, demonstrated the highest content of total polysaccharides in the fruiting body (216 mg. g⁻¹ and 200 mg. g⁻¹). In the case of mineral content, the highest zinc contents were observed from the cultivated strain Ac46 (486.33 mg·kg⁻¹). The maximum iron content was detected from the hybrid strain Ac3 (788 mg·kg⁻¹), and the wild domesticated strain Ac28 (350 mg·kg⁻¹). The crude polysaccharides of the A. cornea strain showed significant antioxidant potential, and the ability of Ac33 and Ac24 to scavenge DPPH radicals and ABTS, which was significantly improved compared to other strains, respectively. Principal component analysis was applied to examine the agronomic traits and chemical compounds of various strains of A. cornea mushrooms. The results revealed that cultivated, wild domesticated, and hybrid strains of A. cornea exhibited distinct characteristics in terms of growth, yield, and nutritional properties.
Conclusion
The crude polysaccharides from A. cornea mushroom strains act as natural antioxidants, the wild, hybrid, and commercial A. cornea mushroom strains can achieve rapid growth, early maturation, and high yields. The evaluation of biochemical indexes and nutritional characteristics of strains with excellent traits provided a scientific basis for initiating high-quality breeding, provided germplasm resources for the production of “functional food” with real nutritional and health value.
In this study, Lactiplantibacillus plantarum ATCC14917 was used to ferment Ganoderma lucidum spore powder. Two polysaccharides were purified from unfermented (GLP) and fermented (FGLP) Ganoderma lucidum spore powder. The chemical structure and antioxidant activity of the polysaccharides were studied. Finally, the effect of GLP and FGLP on the oxidative stress regulation pathway in HepG2 cells was explored. The results showed that the main structural characteristics of Ganoderma lucidum polysaccharides remained unchanged during the fermentation. However, the average molecular weight (Mw) of Ganoderma lucidum polysaccharides decreased from 1.12 × 105 Da to 0.89 × 105 Da. Besides this, the contents of mannose, galactose, and glucuronic acid increased, while the contents of xylose and glucose were decreased. In addition, the content of uronic acid was raised, and the apparent structure was changed from smooth and hard to porous and loose. In antioxidant studies, intracellular ROS and MDA contents in the oxidative stress model were decreased, and T-AOC content was increased under GLP and FGLP intervention. In the investigation of the regulation pathway, Nrf-1 gene expression was up-regulated, and Keap1 gene expression was down-regulated under GLP and FGLP intervention. The antioxidant genes NQO1 and NO-1 expressions were increased to activate the activities of antioxidant enzymes CAT, SOD and GSH-PA to resist oxidative stress. Compared with GLP, FGLP has a stronger regulatory role in this pathway, thus showing more potent antioxidant activity. This experiment is beneficial to the further utilization of Ganoderma lucidum spore powder.
Type 2 diabetes, a long-term chronic metabolic disease, causes severe and increasing economic and health problems globally. There is growing evidence that β-glucans can function as bioactive macromolecules that help control type 2 diabetes with minimal side effects. However, conflicting conclusions about the antidiabetic activities of β-glucans have been published, potentially resulting from incomplete understanding of their precise structural characteristics. This review aims to increase clarity on the structure–function relationships of β-glucans in treating type 2 diabetes by examining detailed structural and conformational features of naturally derived β-glucans, as well as both chemical and instrumental methods used in their characterization, and their underlying anti-diabetic mechanisms. This may help to uncover additional structure and function relationships and to expand applications of β-glucans.
Gold nanoparticles (AuNPs) with size of 12 ~ 25 nm were loaded on the dendritic nanotubes (DNTs), which were self‐assembled by the triple‐helix polysaccharides from black fungus (AF1). The characterization results proved that the AuNPs were dispersed on the surface of DNTs without affecting their tubular structure. Due to the dendritic structure, the loading content of AuNPs could arrived at 46.4%. Moreover, the potential anticancer activities of the complex (DNT‐Au) were evaluated by the induction of apoptosis in HepG2 cells. It was found DNT‐Au could be taken up by cells and enter into lysosomes, further inducing apoptosis in HepG2 cells by ROS‐mediated mitochondrial dysfunction. This work was benefit for the development of natural polysaccharide as a substrate to stabilize nanoparticles in biomedical fields.
Lectins are widely distributed in the natural world and are usually involved in antitumor activities. Auricularia auricula (A. auricula) is a medicinal and edible homologous fungus. A. auricula contains many active ingredients, such as polysaccharides, melanin, flavonoids, adenosine, sterols, alkaloids, and terpenes. In this study, we expected to isolate and purify lectin from A. auricula, determine the glycoside bond type and sugar-specific protein of A. auricula lectin (AAL), and finally, determine its antitumor activities. We used ammonium sulfate fractionation, ion exchange chromatography, and affinity chromatography to separate and purify lectin from A. auricula. The result was a 25 kDa AAL with a relative molecular mass of 18913.22. Protein identification results suggested that this lectin contained four peptide chains by comparing with the UniProt database. The FT-IR and β-elimination reaction demonstrated that the connection between the oligosaccharide and polypeptide of AAL was an N-glucoside bond. Analyses of its physical and chemical properties showed that AAL was a temperature-sensitive and acidic/alkaline-dependent glycoprotein. Additionally, the anticancer experiment manifested that AAL inhibited the proliferation of A549, and the IC50 value was 28.19±1.92 μg/mL. RNA sequencing dataset analyses detected that AAL may regulate the expression of JUN, TLR4, and MYD88 to suppress tumor proliferation. Through the pulmonary flora analysis, the bacterial structure of each phylum in the lectin treatment group was more reasonable, and the colonization ability of the normal microflora was improved, indicating that lectin treatment could significantly improve the bacterial diversity characteristics.
Auricularia auricula (AA) and Auricularia polytricha (AP) are popular edible fungi. This study successfully produced hypoglycemic polysaccharides from un-smashed or smashing and sieving (through a 10-mesh sieve) AA and AP (termed as AAP/AAP-10 and APP/APP-10) via scalable processes (water extraction, ethanolic precipitation and deproteinization). This is the first report to compare the effectiveness of AAP and APP in combating streptozotocin-induced oxidative stress and diabetes-related changes in mice (body weight, fasting blood glucose, serum insulin, proinflammatory mediator and cytokines, oxidative stress-related products, antioxidant enzymes). APP and AAP with different molecular weights and monosaccharide molar ratios could be therapeutic options for diabetes with a low dose (100 mg/kg/day) likely working better. At the same dose, APP generally performed more effective than AAP, and AAP-10/APP-10 seemed slightly more beneficial than AAP/APP. One mechanism underlying these antidiabetic functions might involve the NF-κB and associated signalling pathways. AP is cheaper than AA, thereby representing a favorable source of functional polysaccharides.
Tissue resident intestinal macrophages are known to exhibit an anti-inflammatory phenotype and produce little pro-inflammatory cytokines upon TLR ligation, allowing symbiotic co-existence with the intestinal microbiota. However, upon acute events such as epithelial damage and concomitant influx of microbes, these macrophages must be able to quickly mount a pro-inflammatory response while more inflammatory macrophages are recruited from the blood stream simultaneously. Here, we show that dietary intake of vitamin A is required for the maintenance of the anti-inflammatory state of tissue resident intestinal macrophages. Interestingly, these anti-inflammatory macrophages were characterized by high levels of Dectin-1 expression. We show that Dectin-1 expression is enhanced by the vitamin A metabolite retinoic acid and our data suggests that Dectin-1 triggering might provide a switch to induce a rapid production of pro-inflammatory cytokines. In addition, Dectin-1 stimulation resulted in an altered metabolic profile which is linked to a pro-inflammatory response. Together, our data suggests that presence of vitamin A in the small intestine enhances an anti-inflammatory phenotype as well as Dectin-1 expression by macrophages and that this anti-inflammatory phenotype can rapidly convert toward a pro-inflammatory state upon Dectin-1 signaling.
To explore Auricularia auricula-judae polysaccharides (AAP) as natural anticoagulants for application in the functional food industry, ultrasound assisted extraction (UAE) was optimized for the extraction of AAP by using a response surface methodology (RSM). The maximum extraction yield of crude AAP (14.74 mg/g) was obtained at the optimized extraction parameters as follows: Extraction temperature (74 °C), extraction time (27 min), the ratio of liquid to raw material (103 mL/g), and ultrasound power (198 W). Furthermore, the acidic AAP (aAAP) was precipitated with cetyltrimethylammonium bromide (CTAB) from crude AAP (cAAP). aAAP was further purified using ion exchange chromatography with a DEAE Purose 6 Fast Flow column to obtain aAAP-1. Additionally, according to the HPLC analysis, the aAAP-1 was mainly composed of mannose, glucuronic acid, glucose, galactose, and xylose, with a molar ratio of 80.63:9.88:2.25:1:31.13. Moreover, the results of the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) indicated aAAP-1 had anticoagulant activity, which was a synergic anticoagulant activity by the endogenous and exogenous pathway.
The cell walls of fungi are composed of glycoproteins, chitin, and α- and β-glucans. Although there are many reports on β-glucans, α-glucan polysaccharides are not yet fully understood. This review characterizes the physicochemical properties and functions of (1→3)-α-d-glucans. Particular attention has been paid to practical application and the effect of glucans in various respects, taking into account unfavourable effects and potential use. The role of α-glucans in plant infection has been proven, and collected facts have confirmed the characteristics of Aspergillus fumigatus infection associated with the presence of glucan in fungal cell wall. Like β-glucans, there are now evidence that α-glucans can also stimulate the immune system. Moreover, α-d-glucans have the ability to induce mutanases and can thus decompose plaque.
Auricularia auricula-judae is an important culinary-medicinal mushroom. The A. auricula-judae polysaccharides (AAPs) were prepared from A. auricula-judae in the early stage through alkali extraction and deproteination with the Sevag method, and optimal acid hydrolysis conditions were established by Box−Behnken to prepare the degraded polysaccharides (AAPs-F) from AAPs. In this study, a nonenzymatic glycosylation reaction system was used for the evaluation of the inhibitory effects on the formation of advanced glycation end products (AGEs). In addition, high glucose resistance was assessed by glucose consumption of HepG2 cells and the lifespan of Caenorhabditis elegans under high sugar stress. It was found that both 0.5 mg·mL-1 AAPs and 0.2 mg·mL-1 AAPs-F could significantly inhibit AGE formation in short- and long-term glycosylation (P < .05) in a dose-dependent manner, determined by ultraviolet and fluorospectrophotometry. It indicated activity against AGE formation for different concentrations of AAPs and AAPs-F. AAPs-F at 0.5 mg·mL-1 significantly enhanced the glucose absorption of HepG2 cells by 24.4% (P < .05) in a dose-dependent manner at 24 h, and markedly extended the lifespan of C. elegans by 32.9% (P < 0.05) under high sugar stress conditions. This study demonstrated that the derived hydrolysates produced by the hydrolysis of acid had a prominent effect on the inhibition of AGE formation and relieved the stress state caused by high sugar levels.
Cereal β-glucans are dietary fibres primarily found in oats and barley, and have several positive effects on health, including lowering the postprandial glucose response and the improvement of blood cholesterol levels. Cereal β-glucans have a specific combination of β-(1→4) and β-(1→3) linkages into linear long-chain polysaccharides of high molecular weight. Due to their particular structure, cereal β-glucans generate viscosity within the intestinal tract, which is thought to be the main mechanism of action responsible for their positive health effects. However, cereal grains are rarely consumed raw; at least one cooking step is generally required before they can be safely eaten. Cooking and processing methods more generally will modify the physicochemical characteristics of β-glucans, such as molecular weight, extractability and the resulting viscosity. Therefore, the health impact of β-glucans will depend not only on the dose administered, but also on the ways they are processed or converted into food products. This review aims at summarizing the different parameters that can affect β-glucans efficacy to improve glucose and lipid metabolism in humans.
Current antifungal drugs present poor effectiveness and there is no available vaccine for fungal infections. Thus, novel strategies to treat or prevent invasive mycosis, such as cryptococcosis, are highly desirable. One strategy is the use of immunomodulators of polysaccharide nature isolated from mushrooms. The purpose of the present work was to evaluate the immunostimulatory activity of β-(1,3)-glucan-containing exopolysaccharides (EPS) from the edible mushrooms Auricularia auricula in phagocytes and mice infected with Cryptococcus neoformans. EPS triggered macrophages and dendritic cell activation upon binding to Dectin-1, a pattern recognition receptor of the C-type lectin receptor family. Engagement of Dectin-1 culminated in pro-inflammatory cytokine production and cell maturation via its canonical Syk-dependent pathway signaling. Furthermore, upon EPS treatment, M2-like phenotype macrophages, known to support intracellular survival and replication of C. neoformans, repolarize to M1 macrophage pattern associated with enhanced production of the microbicidal molecule nitric oxide that results in efficient killing of C. neoformans. Treatment with EPS also upregulated transcript levels of genes encoding products associated with host protection against C. neoformans and Dectin-1 mediated signaling in macrophages. Finally, orally administrated β-glucan-containing EPS from A. auricular enhanced the survival of mice infected with C. neoformans. In conclusion, the results demonstrate that EPS from A. auricula exert immunostimulatory activity in phagocytes and induce host protection against C. neoformans, suggesting that polysaccharides from this mushroom may be promising as an adjuvant for vaccines or antifungal therapy.
Four polysaccharide fractions (P‐1: 71.40%, P‐2: 1.95%, P‐3: 1.14%, P‐4: 1.64%) were isolated from crude Polygonatum sibiricum polysaccharide (PSP), processed by water extraction, ethanol precipitation, and further separated with diethylaminoethyl cellulose‐52 anion‐exchange chromatography. Their molecular weights and monosaccharide compositions were characterized by high performance gel chromatography with evaporative light scattering detector and ultraviolet–visible detector. The antioxidant activity of four polysaccharides fractions were assessed by the electron transfer menchanism (DPPH, ferric reducing power, and ABST assays) and chelation of transition metals (Fe²⁺ and Cu²⁺ chelation ability). The highest content fraction P‐1 exhibited the lowest antioxidant activity, and the ranking of antioxidant capacity was P‐4 > P‐3 > P‐2 > PSP > P‐1. After processed by microwave‐assisted degradation, the molecular weight of P‐1 was decreased from 2.99 × 10⁵ to 2.33 × 10³ Da, while the antioxidant activity of degraded P‐1 was about eightfold higher than natural P‐1. These results indicated that the proposed microwave‐assisted degradation approach was an efficacious methodology to improve their bioactivity by lower the molecular weight of polysaccharides.
Practical Application
This study provided an environmentally friendly, convenient and efficient microwave‐assisted degradation technology to process the neutral polysaccharides from Polygonatum sibiricum. The results could be used for the development and utilization of various plant polysaccharides as a kind of food supplement in our daily life.
Auricularia cornea var. Li. is an edible fungi and polysaccharides in Auricularia cornea var. Li. may have bioactive activities. Polysaccharides from Auricularia cornea var. Li. (ACP) was extracted using ultrasound-assisted extraction (UAE) method and compared with hot water extraction (HWE) for extraction yield, extraction rate, purity of polysaccharides, microstructure of residues after extraction, preliminary structure and rheological properties of polysaccharides. Optimum conditions for UAE (particle size of 150–200 mesh, water to raw material ratio of 70:1, extraction temperature at 70 °C for 40 min, ultrasonic amplitude of 40%) and HWE (particle size of 150–200 mesh, water to raw material ratio of 60:1, extraction temperature at 90 °C for 3.0 h) were obtained via single-factor experiment. Under optimum conditions, extraction yield of polysaccharides by UAE was 30.99 ± 1.93% which showed no significant difference with that by HWE (30.35 ± 1.67%) (P > 0.05). Extraction rate (29.29 ± 1.41%) and purity (88.62 ± 2.80%) of polysaccharides by UAE were higher than those by HWE (extraction rate of 24.95 ± 2.78% and purity of 75.33 ± 6.15%) (P < 0.05). Scanning Electron Microscopy (SEM) images of residues by UAE showed more broken cells than those by HWE. Fourier Transform Infrared (FTIR) spectra showed that the dialyzed ACP extracted by HWE and UAE (DACP-HWE and DACP-UAE) had similar characteristic absorption peaks of polysaccharides. Both DACP-HWE and DACP-UAE solutions showed typical shear thinning and temperature-independent behaviors (25–90 °C) and UAE resulted in polysaccharides with remarkably lower viscosity in comparison with HWE. DACP-UAE solutions exhibited more liquid-like state while DACP-HWE solutions solid-like system. Data indicated that ultrasound treatment may be a useful means for extraction of polysaccharides from Auricularia cornea var. Li.
In this study,a novel polysaccharide, AAP-2S, was extracted from Auricularia auricula, and the anti-glycosylationeffect of AAP-2S and its underlying mechanisms were investigated using an in vitro BSA-fructose model anda cel-lular model. The results demonstrated the inhibiting formation of advanced glycation end products (AGEs) invitro by AAP-2S. Concurrently, it attenuated oxidative damage to proteins in the model, preserved proteinsulfhydryl groups from oxidation, reduced protein carbonylation, prevented structural alterations in proteins,and decreased the formation ofβ-crosslinked structures. Furthermore, AAP-2S demonstrated metal-chelating ca-pabilities. GC–MS/MS-based metabolomics were employed to analyze changes in metabolic profiles induced byAAP-2S ina CML-induced HK-2 cell model. Mechanistic investigations revealed that AAP-2S could mitigate gly-cosylation and ameliorate cell fibrosis by modulating the RAGE/TGF-β/NOX4 pathway. This study providesafoundational framework for further exploration of Auricularia auricular polysaccharide asa natural anti-AGEsagent, paving the way for its potential development and application asa food additive.
Obesity has emerged as a crucial factor impacting people's lives, and gut microbiota disorders contribute to its development and progression. Auricularia auricula-judae (Bull.) polysaccharides (AAPs), a traditional functional food in Asia, exhibit potential anti-obesity effects. However, the specific mechanism still needs to be further confirmed. This study investigated the beneficial effects and specific mechanisms of AAPs on obesity. Firstly, AAPs showed significant improvements in overweight, insulin resistance, glucose and lipid metabolism disorders, and liver damage in obese mice. Additionally, AAPs ameliorated gut microbiota disorders, promoting the proliferation of beneficial bacteria like Lactobacillus and Roseburia, resulting in increased levels of SCFAs, folate, and cobalamin. Simultaneously, AAPs inhibited the growth of harmful bacteria, thereby protecting intestinal barrier function, improving endotoxemia, and decreasing the levels of inflammatory factors such as TNF-α and IL-6. Furthermore, AAPs can inhibit the TLR4/JNK signaling pathway while promoting the activation of AKT and AMPK. Importantly, our study underscored the pivotal role of gut microbiota in the anti-obesity effects of AAPs, as evidenced by fecal microbiota transplantation experiments. In conclusion, our findings elucidated that AAPs improve obesity by regulating gut microbiota and TLR4/JNK signaling pathway, offering novel perspectives for further conclusion the anti-obesity potential of AAPs.
An unprecedent glucuronoxylogalactoglucomannan (GXG'G″M), ME-2 (Mw, 2.60 × 105 g/mol; O-acetyl % = 16.7 %), was isolated and purified from water extracts of Auricularia auricula-judae (black woody ear). Firstly, due to much higher O-acetyl contents, we prepared its fully deacetylated products (dME-2; Mw, 2.13 × 105 g/mol) for convenient structure survey. The repeating structure-unit of dME-2 was readily proposed based on Mw determination, monosaccharide compositions, methylation analysis, free-radical degradation and 1/2D NMR spectroscopy. The dME-2 was identified as a highly branched polysaccharide with an average of 10 branches per 10 sugar backbone units. The backbone was only repeating →3)-α-Manp-(1→ residues, substituted at the C-2, C-6 and C-2,6 positions. The side chains included β-GlcAp-(1→, β-Xylp-(1→, α-Manp-(1→, α-Galp-(1→ and β-Glcp-(1→. Secondly, the complex substituted positions of O-acetyl groups in ME-2 were determined to be at C-2, C-4, C-6 and C-4,6 in the backbone and at C-2 and C-2,3 in some side chains. Finally, the anti-inflammatory activity of ME-2 was preliminarily explored on LPS-stimulated THP-1 cells. The above date not only provided the first example for structural studies of GXG'G″M type polysaccharides, but also facilitated development and application of black woody ear polysaccharides as medicinal agents or functional dietary supplements.
Most current strategies of drug delivery systems face momentous challenges owing to obvious biological barriers. It is urgently necessary to develop artificial nanocarriers with biological and physical properties to reduce the severe system cytotoxicity of chemical drugs. Herein, triggered by the stiffness and amphiphilicity of the triple helix β-glucan (LNT), we developed a novel nanocarrier with the hydrophobic cavity for delivering the anti-cancer drug of doxorubicin. In our findings, based on the law of minimum surface energy, LNT with considerable chain stiffness self-assembled into nanotubes (LNT-NT) with the controlled hydrophobic nanotube diameter at the nanometer level positively depending on the molecular weight through hydrogen bonding and hydrophobic interaction in manners of "shoulder-to-shoulder" and "head-to-head" arrangements. The hydrophobic drug of doxorubicin was then demonstrated to be entrapped into LNT-NT through hydrophobic interaction. Doxorubicin loaded into LNT-NT nanocarriers significantly inhibited tumor growth in vitro and in vivo by promoting tumor cell apoptosis and blocking cell proliferation, showing a higher therapeutic efficacy of 74.5 % and less adverse effects than the free doxorubicin, which was ascribed to the enhanced targetability by LNT-NT. In conclusion, this work proposes an alternative strategy for delivering hydrophobic drugs to reduce cytotoxicity and enhance therapeutic effectiveness by constructing β-glucan-based nanotubes as a promising nanocarrier.
In this paper, using to the comprehensive scoring method, pressure shear assisted extraction was used to prepare polysaccharide from Auricularia auricula (PS-AAP)by orthogonal test to optimize the extraction. The highest comprehensive score (90.70) was obtained under 1: 70 g/mL solid-liquid ratio, 110 °C reaction temperature, 60 min reaction time and 1.0 MPa reaction pressure. Compared to AAP by water bath(WB-AAP), PS-AAP led to a higher extraction efficiency and decreased the relative molecular weight. In addition, infrared spectrum(FT-IR) analysis showed that pressure shear assisted did not change the polysaccharide structure. Scanning electron microscope(SEM) showed that PS-AAP was smaller and more broken by pressure shear assisted. Furthermore, the ratio of glucose to mannose in PS-AAP was relatively higher than WB-AAP, which also proved that PS-AAP had certain antioxidant and hypoglycemic activities. Compared with WB-AAP, the inhibition α-glucosidase and α-amylase activity of PS-AAP increased by 11.37% and 24.43% respectively. These results revealed that PS-AAP has the poten- tial value of being a antioxidant and hypoglycemic agent.
Mushrooms either alone or in combination with conventional cancer treatment have been enhanced the efficacy of chemotherapy and radiotherapy improving the patients' quality of life. These therapy effects have been attributed to polysaccharides; the most potent compounds found in the fungi kingdom. Due to their wide range of biological activity and the backbone of glucose residues linked by β-(1 → 3)-glycosidic bonds, often with attached side-chain glucose residues joined by β-(1 → 6) linkages, the mushroom's polysaccharides, particularly the β-glucans, are the most versatile metabolites. Lentinan, D-fraction, and schizophyllan from Lentinula edodes, Grifola frondosa, and Schizophyllum commune, respectively are well-known β-glucans, however, the precise immunomodulation and anticancer mechanisms of action remain to be uncovered. According to several studies, β-glucan can interact with certain receptors on macrophages and dendritic cells, such as dectin-1 and TLRs, producing different cytokines and, in turn, indirectly activating other immune cells including T and B cells. Moreover, recent findings have proved that β-glucans have a direct cytotoxic effect on cancer cells suppressing proliferation and enhancing apoptosis possibly via multiple pathways such as PI3K/Akt/mTOR, NF-κB-, ERK-, ERα-, caspase- and p53-dependent pathways.
Indeed, this study intends to provide information on the lentinan, D-fraction, and schizophyllan by examining the extraction procedures, chemical composition, and immunostimulatory and antitumoral biological activities. Future research directions should be directed toward improving the validity and reliability of randomized trials to confirm the potential role of β-glucans on the immune system and as anticancer therapy.
Exacerbating oxidative stress has become a promising strategy for effective cancer therapy. However, the hyperactive antioxidant systems in tumor cells neutralize this effect, reducing potency and promoting drug resistance. Herein, we put forward a new insight into the cancer therapy by depleting glutathione (GSH) and inducing cellular redox imbalance based on a selenium nanoparticle (SeNPs) loaded β-glucan nanotube (BFP-Se) composed of natural triple-helix glucan, derived from black fungus. BFP-Se targeted tumor tissues through enhanced permeability and retention effects, enhancing the bioavailability of SeNPs. Metabolomics unveiled that BFP-Se related metabolic responses were mainly associated with oxidative stress in hepatoma cells. In vivo and in vitro experiments prove that BFP-Se effectively depleted the intracellular GSH, inhibited TXNIP/TRX and NRF2/GPX4-associated antioxidant systems expressions, while produced reactive oxygen species by reacting with intracellular H2O2, ultimately leading to apoptosis and ferroptosis of hepatoma cells. This work offers a deeper understanding of nanomedicine-bio interactions and provides a forward look at cancer therapy by depleting GSH and inducing cellular redox imbalance.
Finding an eco-friendly homogeneous catalyst with high efficiency to rapidly clean up dyes and 4-nitrophenol in wastewater is urgently to be solved. Herein, we ingeniously designed a stable and reusable homogeneous catalyst of ultra-small silver nanoparticles (AgNPs)-loaded triple-helix β-glucan (BFP) nanomaterial (BFP-Ag) via one-step reduction in dimethyl sulfoxide with BFP as the reductant. Moreover, BFP triplex formed nanotubes, acting as a matrix to disperse and stabilize AgNPs through Ag-O bonds in water. The ultra-small AgNPs (2.8-10 nm) were embedded into the hollow cavity of BFP nanotubes indicated by the aqueous solution color. BFP-Ag could effectively catalyze reduction of 4-nitrophenol with the higher catalytic efficiency for smaller size of AgNPs. The catalytic turnover frequencies of BFP-Ag nanocomposite for reduction of Congo Red, Methyl Orange, Rhodamine B and 4-nitrophenol were determined to be 1423.02 h⁻¹, 349.52 h⁻¹, 452.78 h⁻¹ and 1335.89 h⁻¹, respectively, which were far higher than those of the most reported catalysts. BFP-Ag maintained over 95% conversion after eight continuous cycles and the entire catalytic and recovery process could be achieved by a simple filter device for the practice applications. The hot filtration and recovery test verified the homogeneity and stability of BFP-Ag. This work provides a novel strategy for designing environmental-friendly homogeneous catalysts in wastewater treatment and expands the application of natural polysaccharides in the synthetic catalysis.
In this study, we explored structural differences of five commercial samples of yeast β-glucan. Samples were assayed for their β-glucan content and the yeast storage carbohydrate, glycogen. The β-glucan content ranged from 74% to 86%, the glycogen content varied from 0-20%. The linkage pattern of each sample was measured by the partially methylated alditol acetate method. This method showed that the samples varied from 1.9% to 9.2% branching. The side chain length distribution for each sample was analyzed by an alkaline degradation assay followed by ion chromatography. The side length distributions of the samples were shown to be similar. The samples were also analyzed by FT-IR and ¹HNMR spectroscopy but it was difficult to derive quantitative differences in the samples by these methods. Our findings confirm that each proprietary source of yeast β-glucan has a unique purity profile, branching, and linkage patterns that determine the chemical structure and composition.
Natural polysaccharide as the third abundant biomacromolecule has attracted considerable attentions due to their superior anti-tumor activities. However, the anti-tumor mechanism of polysaccharides has not been completely understood. Herein, the anti-tumor effects of black fungus polysaccharide (BFP), a typical β-glucan was comprehensively investigated, and the anti-tumor mechanism was obtained from metabolomics profiling. The in vitro results demonstrate that BFP inhibited the proliferation, migration and invasion of hepatoma carcinoma cells (HCC) through inducing the cell apoptosis and arresting the cell cycle at S phase without direct cytotoxicity. The hepatoma-bearing nude mice experiments further demonstrate that BFP could significantly inhibit the growth without system toxicity in vivo. Mass spectrometry-based metabolomics unveils that BFP significantly disturbed the multiple metabolic pathways, leading to the inhibition of tumor cells proliferation by promoting DNA damage, attenuating DNA damage repair, and inhibiting DNA synthesis. This study provides new insights for pharmacological research and clinical practice of polysaccharides.
Bletilla striata polysaccharides (BSPs) are effective for anti-inflammatory, detumescence, and radicals scavenging, with important applications in the area of food chain, pharmacy science, and health care. In this study, we comprehensively studied the interplay between the polysaccharides' formation, physicochemical properties, rheological properties, and associated antioxidant activities of BSPs from different extraction methods. The crude polysaccharides obtained from Bletilla striata by using the hot water extraction (BSPs-H), alkali-assisted extraction (BSPs-A), boiling water extraction (BSPs-B), and ultrasonic-assisted extraction (BSPs-U) methods showed different molecular weights, monosaccharide compositions, glycosidic bond compositions, and zeta potentials, but with the same IR spectra characteristic and thermal stability. By the above-mentioned four kinds of extraction methods, the resultant BSPs exhibited various degrees of reticular and lamellar structure. All the BSPs solutions exhibited shear-thinning behavior with the increase of the shear rate. Among these BSPs, BSPs-A exhibited better DPPH and ABTS radical scavenging activities and reducing power, whereas BSPs-H showed better hydroxyl radical scavenging activities.
Size controllable silver nanoparticles (AgNPs) were synthesized in situ on the polysaccharides-based nanotubes, which were formed by the triple-helix polysaccharide extracted from black fungus (AF1). The results of transmission electron microscope (TEM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) proved that AgNPs with the size from 10-25 nm were uniformly dispersed on the surface of AF1 dendritic nanotubes without affecting their tubular morphology. Moreover, due to the tubular structure, the loaded silver content of the composites (AgNPs and AF1 nanotube, AF1-Ag) could reach about 50% by thermogravimetric analysis (TG) evaluation. Thus, the smaller size of AgNPs and higher silver loading content suggest that the composites could be applied in the biomedical field. The antibacterial properties of AF1-Ag were evaluated as an example in the present work. As expected, the culture medium contained a few of AF1-Ag (10% ω%, c = 50 μg/mL) exhibited obvious antibacterial properties, and the effect of bacteriostasis increased with the increase of the amount of supported silver content. Taken together, the AF1-Ag with good antibacterial activity and good stability has the potential to be applied in the antibacterial field.
Triple helix conformation of polysaccharides is generally believed to be associated with their biological activities. However, the formation mechanisms and analytical methods for the triple helix polysaccharides, to our best knowledge, have not been systematically investigated. This article reviews specifically the literature on the formation and characterization of triple-helix polysaccharides. The formation mechanisms and related structural-conformation-bioactivity relationships are discussed; various analytical methods for characterizing triple-helix polysaccharides are summarized. This review devotes to a better understanding of the formation of polysaccharides based triple-helix structure and related analytical methods. These could provide some insights and inspirations for their applications in both food and pharmaceutical industries.
Although the application of Auricularia auricula-judae (AAJ) for health purposes has a long tradition in Asia, there is a lack of research on the functional nutrition of AAJ; the current research focused on polysaccharides has been too unitary compared to other mushrooms in recent years. Identification, extraction, and large-scale production of biologically active substances have emerged as critical determinants that determine AAJ becoming a functional food. AAJ is being treated in a restrained manner, despite having significant potential as a drug or a source of pure bioactive substances. Functional ingredients of mushrooms and AAJ have emerged as a new impetus for researchers interested in developing functional foods. This review presents an overview of current studies relevant to nutrition and the application of AAJ. The physiological conditions of AAJ and the corresponding functional ingredients beneficial to human health are reviewed to better understand the function and mechanisms of different nutrient contents. Relevant methods for evaluating the efficiency of extraction are also summarized. Finally, current limitations and the future scope for functional ingredients of AAJ are identified and discussed.
In recent years, glucan has become one of the hotspots in life science research. It is widely concerned because of its advantages, such as good immune regulation, antitumor, antivirus, hypoglycemic and lipid‐lowering effects, antioxidation, antiaging, low toxicity, and high efficiency. At present, there are still two problems in the pharmacodynamics of glucans. Firstly, compared with other drugs used in clinic, most of the glucans still lack information about the mechanism of action between glucans and corresponding ligands in vivo. Secondly, the research on the structure–activity relationship of glucans is still slow. Herein, the structure–activity relationships of glucans were reviewed. The relationship between structure and biological activity is very important for the development of new glucan drugs.
Natural polysaccharides as sustainable polymers are rich sources with good biological safety and various biological functions, which are important research topics in the fields of food and medicine. However, their widespread medical application is hindered due to the technical difficulties in the extraction/purification and chain structure characterization of polysaccharides, as well as due to the lack of thorough understanding of the macromolecular chain conformation and the mechanism of bioaction for these polysaccharides. To provide a relatively comprehensive reference for relevant researchers, we mainly introduce several natural polysaccharides with different chain conformations including random coil, hyperbranched sphere, and triple helix in solution, as well as summarize their extraction and purification processes, characterization of chemical structure and chain conformation, anti-tumor activities and potential mechanisms.
The objective was to investigate the in vitro antioxidant activity of a novel polysaccharide AAP–3–1 from Auricularia auricula. AAP–3–1 was isolated from the fruiting bodies of A. auricula by hot water extraction and ethanol precipitation and was purified by DEAE FF ion exchange chromatography and Superdex 200 gel filtration chromatography. The molecular weight and monosaccharide composition were determined by high performance gel permeation chromatography and high–performance liquid chromatography, respectively. Ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy were used for structural characterization. The results showed that AAP–3–1 is a heteropolysaccharide and is mainly composed of mannose and glucose in a molar ratio of 1.4:1 with a molecular weight of 320.9 kDa. AAP–3–1 exhibited antioxidant activity in a concentration–dependent manner and the scavenging rates at 1.6 mg/mL on superoxide anions and hydroxyl and 1,1–diphenyl–2–picrylhydrazyl radicals were 88.13%, 93.03% and 68.31%, respectively. AAP–3–1 effectively ameliorated 2,2′–azobis–2–methyl–propanimidamide–induced oxidative stress in HepG2 cells by inhibiting reactive oxygen species generation, decreasing the content of malondialdehyde, and increasing the activities of superoxide dismutase, glutathione peroxidase and catalase. The results indicated that the antioxidant mechanism of AAP–3–1 was associated with both non–enzymatic and enzymatic defense systems.
Auricularia auricula is a well-known traditional edible fungus with high nutritional and pharmacological values. Polysaccharides are identified as one of the pivotal bioactive constituents of natural extracts of A. auricula. Accumulating evidence has revealed that polysaccharides from A. auricula (AAPs) exhibit diverse biological functions. Hence, a systematic review of research advances and future prospects of AAPs is very necessary for facilitating their better understanding. In this review, we have summarized current knowledge about extraction and purification methods, structural features, biological activities and potential molecular mechanisms of AAPs. Besides, the proposed structure-activity relationships of AAPs have also been highlighted and discussed. This review may provide some valuable insights for further researches regarding AAPs.
An efficient enzymatic hydrolysis method was developed and optimized for the degradation of auricularia auricula polysaccharide (AAP) and the degradation product of AAP was characterized. Cellulase was used for the degradation of AAP. The yield of reducing sugar and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate were used as indices to optimize the enzymatic hydrolysis of AAP, based on response surface methodology (RSM). The resulting optimal enzymolysis conditions were as follows: enzyme dosage, 13,500 U/g; enzymolysis temperature, 50 °C; and pH, 4.2. Under these conditions, the actual yield of reducing sugar was 16.50 mg/mL and the DPPH radical scavenging rate was 87.97%. The degradation product of AAP (C-EAAP) was homogeneous and contained alpha and beta glycoside bonds, but did not contain protein or nucleic acid. The molecular weight of the degradation product was 5.94 × 10⁵ Da. Monosaccharide composition analysis revealed that C-EAAP was composed of mannose (57.1%), glucuronic acid (10.0%), rhamnose (0.4%), glucose (22.5%), galactose (2.9%), xylose (6.0%), and fucose (1.1%). The antioxidant activity of the polysaccharide indicated that C-EAAP had better antioxidant activity than AAP. The scavenging rates of C-EAAP for hydroxyl radicals (·OH) and superoxide anion radicals (O2⁻·) were 1.65 and 1.90 times those of AAP.
Acute myeloid leukemia (AML) is a difficult therapeutic hematological tumor. It is urgent to find a non-toxic natural drug to treat AML. Herein, the selenium nanoparticles (SeNPs) embedded in nanotubes consisted of triple helix β-(1, 3)-D-glucan (BFP) from the black fungus that were wrapped to form stable inclusion complex BFP-Se, which was self-assembled and exhibited high stability in water. In vitro, the BFP-Se significantly inhibited the proliferation of AML cells and increased the cytotoxicity on AML cells. On single-cell levels, the U937 cells were gradually swelled and lysed with BFP-Se treatment on optofluidics chips. Further, the blood and bone marrow analysis indicated the anti-leukemia effects of BFP-Se in vivo. Moreover, BFP-Se increased the total antioxidant capacity of AML cells and decreased the expression of c-Jun activation domain-binding protein-1 and thioredoxin 1. Our results suggest that this biocompatible polysaccharide nanotube containing Se nanoparticles would provide a novel strategy for AML therapy.
Fermentation technology was used to improve the antioxidant activities of Auricularia auricula polysaccharide (AAP). Response surface methodology (RSM) was used to optimize the fermentation conditions. The effects of 4 independent factors: water content (X1: 40–80%), inoculation amount (X2: 2–20%), temperature (X3: 24–32 °C), and time (X4: 4–6 d) on the biological degradation efficiency were evaluated. The RSM results showed that the optimal fermentation conditions were: X1: 61.7%, X2: 12.4%, X3: 31.0 °C, X4: 5.5 d. Verification tests showed no significant differences between the practical and the predictive values for each response. Under the optimal conditions, the degradation rate was 26.89 ± 0.14%, without significant differences with the predicted value (27.03%). The degradation products were classified to different molecular weight (Mw) polysaccharide fragments using membrane separation technology. The FT-IR analysis and monosaccharide composition analysis of degraded AAP (D-AAP-VI) showed that D-AAP-VI was a furan type polysaccharide, which was different from the total AAP (pyran type). In addition, compared to total AAP, the antioxidant activities in vitro of D-AAP-VI were significantly improved (p < 0.05) and D-AAP-VI showed the strongest antioxidant activity. These results indicated that biological degradation may be a suitable way to improve the antioxidant activities of natural polysaccharides.
Auricularia mushrooms are known for their bioactive compounds, mostly polysaccharides, which have numerous biological activities, such as antioxidant, antitumor, immunomodulatory, hyperlipidemic, antidiabetic, anticoagulant and hepatoprotective effects. Over the past decades, there has been a consistent focus on the isolation, chemical properties and bioactivities of polysaccharides from Auricularia. This review will cover what is known about Auricularia polysaccharides (AP) especially for several common species, including A. auricula-judae, A. auricula, A. polytricha, and A. cornea var. Li. The isolation and purifications, structural characterizations, chemical modifications, and biological activities of these AP and their derivatives will be discussed, thus to provide a foundation for the further investigation, production, and application of AP as functional foods and therapeutic agents.
Natural polysaccharides derive from renewable biomass sources, and are regarded as environmentally friendly and sustainable polymers. As the third abundant biomacromolecule after protein and nucleic acid in nature, polysaccharides are also closely related to many different life activities. It is worth noting that β-glucans are one of the most widely reported active polysaccharides, and usually are considered as biological response modifiers (BRMs). Among them, β-glucans with triple-helix conformation have been the hottest and most well-researched polysaccharides at present, especially lentinan (LNT) and schizophyllan (SPG), which have already been used as commercial clinic antitumor drugs in some Asian countries. Thus, creation of these active triple-helix polysaccharides will be beneficial to the research and development of sustainable “green” biopolymers in the fields of the food and life sciences. Therefore, full fundamental research of triple-helix polysaccharides is essential to discovery more polysaccharide-applications. In this review, the recent research progress of chain conformation, bioactivities and structure-function relationship of β-glucans with triple-helix conformation are summarized, with 247 references from 1949 to 2019. The main contents can be divided as follows: the characterization methods of the macromolecular conformation, proof of triple helices, bioactivities and structure-function relationship. We believe that the governments, enterprises, universities and institutes, which are dealing with the survival and health of human beings, will expect the development of the natural bioproducts in the future. Hence, a deep understanding of β-glucans with triple-helix chain conformation is essential for the successful applications of the natural medicines and biologics for a sustainable world.
The structural characterization and antioxidant activity of four Auricularia polysaccharides (A.cornea ACP)、A.auricula(AAP)、A.polytricha (APP) and M.fungus(MFP)) were studied in this paper. The results shown: polysaccharides of four Auricularia were mainly composed of mannose and galactose, all polysaccharides contained uronic acid and pyran ring structure with spectroscopy and NMR analysis. There was a significant difference in the total antioxidant capacity and APP was significantly higher than the other polysaccharides. The ability of APP to scavenge DPPH radicals and hydroxyl radicals was significantly higher than that of other polysaccharides, respectively. The molecular weight was significantly positively correlated with DPPH radicals, superoxide anion radicals and hydroxyl radicals. Total antioxidant capacity was significantly negatively correlated with fucose and galactose. The result indicated that fucose and galactose jointly determine total antioxidant capacity. The polysaccharide from four Auricularia had good oxidation resistance and could be used as natural antioxidants.
Caenorhabditis elegans is an important model organism for studying stress response mechanisms and identifying genetic pathways that influence longevity. The present study was designed to explore the in vivo -antioxidant potentials...
Polysaccharides isolated from natural products, have raised an increasing interest due to their variety of beneficial health effects. Plantago spp., a valuable Chinese herbal plant, has a long history of cultivation and is widely accepted as traditional herbal medicines and functional foods in Asian counties. Polysaccharide is a very important biological active ingredient in the Plantago spp., which has a variety of biological effects, including immunomodulatory, antioxidant, antitumor, and hypoglycemic activities, among others. A large number of articles have been reported the structural identification and activity evaluation of psyllium polysaccharides. However, the structure-activity relationship of psyllium polysaccharides has not been well established. Therefore, this review focused on the extraction, purification, structural characterization, chain conformation, and biological activities of psyllium polysaccharides, which can provide useful research underpinnings and updated information for the development and application of related polysaccharides in functional foods and medicinal field.
Radiation is known to be associated with pathology of various human diseases. This study has focused on the effect of radiation on glucose homeostasis with regard to metabolic function of liver and pancreas and the effect of polysaccharide from the fruiting bodies of Auricularia auricular (SNAAP) on glucose metabolism. The 60Co-γ-radiated mice displayed destroyed redox equilibrium, accompanied by increased blood glucose accumulation, decreased insulin and hepatic glycogen contents, impaired blood glucose tolerance ability, abnormal changes in activities of glucose metabolism-related enzymes and damaged hepatic and pancreatic function, while SNAAP can restore the disordered glucose metabolism to some extent. Increased phosphorylation of JNK and FoxO1, reduced phosphorylation of Akt and GSK-3β and increased expression of PEPCK, G6Pase and GYS2 in the liver as well as the decreased expression of PDX1, GLUT2 and IRS1 in the pancreas of radiated mice were recovered after treated with SNAAP, leading to an improved gluconeogenesis and glycogen synthesis. These findings clearly indicate that SNAAP has significant potency in radiation-induced glucose metabolism disorder through modulating the JNK pathway in the liver as well as the PDX1/GLUT2 in the pancreas.
The objective was to determine the contribution of A. auricular polysaccharides (AAP) in modulating the composition and diversity of the intestinal microbe in mice. AAP was extracted from A. auricula freeze-dried powder and different amounts of AAP (40, 80, 160 mg AAP/kg body weight) were administered to 6 week-old male ICR mice by gavage feeding over a five-week period. AAP feeding changed the intestinal environment in the mice. The pH value of the intestinal compartments decreased while SCFAs concentrations increased in AAP-fed groups, in a dose dependent manner, compared to the controls (P < .05). High throughput sequencing revealed an enrichment in the diversity and an alteration in the composition of the fecal microbiota in the AAP fed mice with a significant decrease in the Firmicutes/Bacteroidetes ratio (P < .05). The relative abundances of Porphyromonadaceae and Bacteroidaceae also increased in the AAP fed mice which positively correlated with an increase in serum IgA and IgG concentrations (P < .05). The findings from this study show that AAP modulates the mouse gut microbiota and may contribute, at least in part, to some of the reported beneficial effects from the consumption of the mushroom, A. auricula.
In the present study, the bamboo shoot (Chimonobambusa quadrangularis) residue (BSR)-derived polysaccharides (CPS) were dried using different drying procedures, including hot air-, vacuum-, freeze-, and spray-drying. The influences of different drying procedures on the chemical compositions, physicochemical characteristics, and antioxidant activity of CPS were investigated. The results indicate that freeze-dried CPS possessed the highest polysaccharide yield (8.86%) and uronic acid content (9.42%), and the lowest medium-high molecular weight (117.49 kDa) and glucose content (5.81 mol%). Also, freeze-dried CPS had better water (5.17 g/g) and oil retention capacities (2.32 g/g) than hot air- and vacuum-dried CPS. Moreover, freeze-dried CPS exhibited the most potent antioxidant ability. Based on correlation analysis, a higher uronic acid content, lower molecular weight and lower glucose content might be closely associated with the better antioxidant activity of the freeze-dried CPS. Hence, the above results revealed freeze-drying was the optimal method for industrial production of high quality CPS.