Anti-tumor and macrophage activation induced by alkali-extracted polysaccharide from Pleurotus ostreatus

Structural characterization, anti-tumor and immunomodulatory activity of intracellular polysaccharide from Armillaria luteo-virens

Armillaria luteo-virens (A. luteo-virens) is a kind of edible fungus mainly exists in Qinghai-Tibet of China, but at present only very few studies focus on the bioactivities of its polysaccharides. This study aimed to purify and characterize the structure features of a novel intracellular polysaccharide (ALP-A) derived from A. luteo-virens and explore its potential anti-tumor and immunomodulatory activities. Through systematic separation and purification, we obtained a homogeneous ALP-A with an average molecular weight of 23693Da. Structural analysis indicated that ALP-A was mainly composed of glucose and mannose with a molar ratio of 6.02:1. The repeating unit of ALP-A was →4) -α-D-Glcp-(1→ backbone with α-Glcp-(1→ and α-Manp-(6→ side chains which branched at O-2 position. The anti-tumor assays in vivo suggested that ALP-A could effectively restrain S180 solid tumor growth, protect immune organs and promote the secretion of cytokines (IL2, IL6 and TNF-α) in serum. Besides, in vitro immunomodulatory assays indicated that ALP-A could improve proliferation, phagocytic capacity and raise the level of NO and cytokines in Raw264.7 cells. These results demonstrate that ALP-A which possess potential antitumor and immunomodulatory abilities can be developed as a new functional food.

Antitumor effects of polysaccharides from medicinal lower plants: A review

Cancer is one of the leading causes of death worldwide, yet the drugs currently approved for cancer treatment are associated with significant side effects, making it urgent to develop alternative drugs with low side effects. Polysaccharides are natural polymers with ketone or aldehyde groups, which are widely found in plants and have various biological activities such as immunomodulation, antitumor and hypolipidemic. The lower plants have attracted much attention for their outstanding anticancer effects, and many studies have shown that medicinal lower plant polysaccharides (MLPPs) have antitumor activity against various cancers and are promising alternatives with potential development in the food and pharmaceutical fields. Therefore, this review describes the structure and mechanism of action of MLPPs with antitumor activity. In addition, the application of MLPPs in cancer treatment is discussed, and the future development of MLPPs is explored.

Structural Characterization and Immunobiological Activity of Polysaccharides from Astragalus Oyster Mushroom

When added to mushroom growing substrates, edible and medicinal herbs affect the mushrooms' nutritional and medicinal value. In this study, polysaccharides (P⁰OP-I and P¹⁵OP-I) were extracted and purified from oyster mushrooms grown on substrates supplemented with 0% and 15% Astragalus roots (P⁰ and P¹⁵), respectively, and their chemical structure and immunobiological activities were compared. P¹⁵OP-I and P⁰OP-I were extracted using ultrasound-assisted hot water and deproteinized with the Sevage method, depigmented with 30% H₂O₂, desalted with dialysis, and purified using DEAE-52 cellulose and Sephadex G-100 dextran column chromatography. The molecular weight of P⁰OP-I and P¹⁵OP-I was 21,706.96 and 20,172.65 Da, respectively. Both were composed of monosaccharides D-mannose, galacturonic acid, D-glucose, D-galactose, and L-arabinose but in different molar ratios, and both were connected by a pyranoside linkage. P¹⁵OP-I consisted of higher contents of mannose, glucose, galactose and arabinose and lower content of galacturonic acid as compared to P⁰OP-I. Both P⁰OP-I and P¹⁵OP-I induced NO and TNF-α production but did not show cytotoxic effect or induce ROS generation in RAW264.7 cells. P¹⁵OP-I showed a stronger ability to promote NO and TNF-α production relative to P⁰OP-I. In vitro experiments showed that the immunomodulatory activity of P⁰OP-I and P¹⁵OP-I in RAW264.7 macrophages were mediated by the JNK/MAPK, Erk/MAPK, and NF-κB signaling pathways. The results would be helpful for elucidation of the health promoting mechanism of Astragalus oyster mushrooms as a source of neutraceuticals.

Structure Characterization, In Vitro Antioxidant and Anti-Tumor Activity of Sulfated Polysaccharide from Siraitia grosvenorii

From Siraitia grosvenorii, a natural polysaccharide named SGP-1 was discovered, and its purity was determined to be 96.83%. Its structure is a glucan with 4-, 6- and 4,6-linked glucose units. In this paper, the sulfated derivative S-SGP of SGP-1 was prepared by the chlorosulfonic acid method. The sulfated derivatives were analyzed by Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), and scanning electron microscopy (SEM). The degree of substitution (DS) of the polysaccharide is 0.62, and the weight average molecular weight (Mw) is 1.34 × 10⁴ Da. While retaining the morphological characteristics of polysaccharides, S-SGP appeared a large number of spherical structures and strong intermolecular forces. The in vitro activity study of S-SGP showed that the sulfated derivatives had the ability to scavenge DPPH radicals, hydroxyl radicals and superoxide anions, and the scavenging power tended to increase with the increase in polysaccharide concentration. It can inhibit the growth of human hepatoma cells (HepG2), human breast cancer cells (MDA-MB-231) and human non-small cell lung cancer cells (A549) in vitro. In addition, the treatment of A549 cells with sulfuric acid derivatives can decrease the mitochondrial membrane potential, induce apoptosis, and alter the expression of apoptosis-related mRNA and protein.

Chemometric-Based Analysis of Metabolomics Studies of Bioactive Fractions of Pleurotus osteratus and Their Correlation with In Vitro Anti-Cancer Activity

Richness in nutrients with an ample of the myco-bioactive molecules makes Pleurotus osteratus preferential mushroom. In this paper, we conducted a preliminary study on bio-assay-guided fractionation of dichloromethane:ethanol crude extract (1:1, v/v) of P. osteratus (CD) against human breast cancer cell line (MDA-MB-231). Later, CD and its potent hexane (H) and ethyl acetate (EA) fraction were screened against a panel of a human cancer cell lines. H fraction possesses higher cytotoxicity followed by EA and CD. Literature review revealed that polyphenol and ergosterol are the biomarkers found in P. osteratus and could responsible for its cytotoxic potential. Accordingly, hyphenated liquid chromatography with tandem mass spectrometry (LC-MS/MS)-based polyphenol and ergosterol-targeted myco-metabolite profiling of CD, H, and EA fractions were carried out. Despite being significantly rich in polyphenol and ergosterol content, EA fraction showed moderate cytotoxicity. Considering this, liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF/MS)-based untargeted myco-metabolite profiling of CD, H and EA fractions was further conducted to identify a new biomarker. Tentatively, 20 myco-metabolites were identified, belonging to the class of steroids, alkaloid, terpenoid, fatty alcohol, and polyketide. The myco-metabolite variabilities among potent samples in correlation to their in vitro anti-cancer activity was explored using the different chemometric tools: principal component analysis (PCA), hierarchical clustering analysis (HCA), and partial least square (PLS). A probable synergistic action among identified myco-metabolites (betulin, solanocapsine, ophiobolin F, linoleoyl ethanolamide, (13R,14R)-7-labdene-13,14,15-triol, asterosterol, cholest-5-ene, (3b,6b,8a,12a)-8,12-epoxy-7(11)-eremophilene-6,8,12-trimethoxy-3-ol, beta-obscurine, myxalamid B, momordol, and avocadyne 4-acetate) may be responsible for the observed cytotoxicity potential of H fraction of P. osteratus.

Mushroom Polysaccharide-Assisted Anticarcinogenic Mycotherapy: Reviewing Its Clinical Trials

Of the biologically active components, polysaccharides play a crucial role of high medical and pharmaceutical significance. Mushrooms have existed for a long time, dating back to the time of the Ancient Egypt and continue to be well explored globally and experimented with in research as well as in national and international cuisines. Mushroom polysaccharides have slowly become valuable sources of nutraceuticals which have been able to treat various diseases and disorders in humans. The application of mushroom polysaccharides for anticancer mycotherapy is what is being reviewed herein. The widespread health benefits of mushroom polysaccharides have been highlighted and the significant inputs of mushroom-based polysaccharides in anticancer clinical trials have been presented. The challenges and limitation of mushroom polysaccharides into this application and the gaps in the current application areas that could be the future direction have been discussed.

Immunomodulatory effects of selenium-enriched peptides from soybean in cyclophosphamide-induced immunosuppressed mice

In this study, selenium-enriched soybean peptides (<3 kDa, named Se-SPep) was isolated and purified from the selenium-enriched soybean protein (Se-SPro) hydrolysate by ultrafiltration. The in-vivo immunomodulatory effects of Se-SPep were investigated in cyclophosphamide-induced immunosuppressed mice. Se-SPep treatment could alleviate the atrophy of immune organs and weight loss observed in immunosuppressive mice. Besides, Se-SPep administration could dramatically improve total protein, albumin, white blood cell, immunoglobulin (Ig) M, IgG, and IgA levels in blood. Moreover, Se-SPep strongly stimulated interleukin-2 (IL-2), interferon-gamma (IFN-γ), nitric oxide (NO), and cyclic guanosine monophosphate productions by up-regulating mRNA expressions of IL-2, IFN-γ, and inducible NO synthase in spleen tissue. Furthermore, Se-SPep exhibits more effective immunomodulatory activity compared to Se-SPro and SPep. In conclusion, Se-SPep could effectively enhance the immune capacity of immunosuppressive mice. These findings confirm Se-SPep is an effective immunomodulator with potential application in functional foods or dietary supplements.

Classification, structure and mechanism of antiviral polysaccharides derived from edible and medicinal fungus

The deficiency of chemical-synthesized antiviral drugs when applied in clinical therapy, such as drug resistance, and the lack of effective antiviral drugs to treat some newly emerging virus infections, such as COVID-19, promote the demand of novelty and safety anti-virus drug candidate from natural functional ingredient. Numerous studies have shown that some polysaccharides sourcing from edible and medicinal fungus (EMFs) exert direct or indirect anti-viral capacities. However, the internal connection of fungus type, polysaccharides structural characteristics, action mechanism was still unclear. Herein, our review focus on the two aspects, on the one hand, we discussed the type of anti-viral EMFs and the structural characteristics of polysaccharides to clarify the structure-activity relationship, on the other hand, the directly or indirectly antiviral mechanism of EMFs polysaccharides, including virus function suppression, immune-modulatory activity, anti-inflammatory activity, regulation of population balance of gut microbiota have been concluded to provide a comprehensive theory basis for better clinical utilization of EMFs polysaccharides as anti-viral agents.

Promising anticancer activity of polysaccharides and other macromolecules derived from oyster mushroom (Pleurotus sp.): An updated review

Cancer dominates among many causes of mortality worldwide. Traditional chemotherapeutic agents are powerful anti-cancer agents employed for treatment of this deadly disease. However, they are always associated with toxic side effects and immunosuppression making person more vulnerable to tumor relapse and fatalities. A promising alternative could be identification, isolation and transfer of naturally occurring bioactive macromolecules to the tumorigenic population. Oyster mushroom, a major source of nutraceuticals, belonging to class basidiomycetes of kingdom Mycota is known to have immense therapeutic properties. It is a reservoir of macromolecules like β-glucan, α-glucan, resveratrol, concanavalin A, cibacron blue affinity protein, p-hydroxybenzoic acid, ergosterol, linoleic acid etc. that are responsible for mediating anti-tumor, immunomodulatory, antioxidant, and anti-diabetic roles. Various studies have shown that extracts derived from oyster mushroom is rich in polysaccharides like β-glucan and other macro molecules which have an anti-proliferative effect against cancer cell lines, without harming the normal cells. This review presents a brief highlight of the work covering the overall significance of oyster mushroom in different types of cancer treatment. It also explores the immunomodulatory effects of polysaccharides, proteoglycans and polypeptides derived from oyster mushroom that boosts the immune system to overcome the limitation of traditional cancer therapies.

Structural Characterization of an Alkali-Soluble Polysaccharide from Angelica sinensis and Its Antitumor Activity in Vivo

A novel alkali-soluble polysaccharide (AASP) was isolated from Angelica sinensis (Oliv.) Diels under aqueous alkali treatment, and its structural characterization and antitumor activity in Vivo were evaluated in present study. Results of HPGPC and IC revealed that AASP was a neutral polysaccharide containing Ara, Gal and Glc in the mole ratio of 1.00 : 2.26 : 24.43, with the average molecular weight of 4.7 kDa. Periodate oxidation, Smith degradation, methylation, FT-IR, and NMR analyses further demonstrated that a preliminary structure of AASP was proposed as follows: (1→3)-linked arabinose, (1→6)-linked galactose, and (1→), (1→4), (1→6), (1→3,6)-linked glucose with α- and β-configuration. In Vivo antitumor assays, AASP exhibited prominent antitumor effects on H22 hepatoma cells with an inhibitory ratio of 48.57 % and effectively protected thymuses and spleens of tumor-bearing mice. Besides, AASP displayed a proliferation stimulating activity of immunocytes (splenocytes, peritoneal macrophages and natural killer cells), and an auxo-action for cytokines release (TNF-α, IL-2 and IFN-γ), leading to the apoptosis of H22 solid tumors cells via G0/G1 phase arrested. The above data demonstrated that AASP holds great application potential to be a safe and effective antitumor supplement in the future.

Differential Induction Pattern Towards Classically Activated Macrophages in Response to an Immunomodulatory Extract from Pleurotus ostreatus Mycelium

Pleurotus ostreatus mushroom preparations have been investigated because of their ability to modulate the immune function. However, there is still no consensus regarding the activation and polarizing effect on macrophages by Pleurotus-derived bioproducts. This study examined the immune-activating effect of a mycelium-derived P. ostreatus aqueous extract (HW-Pm) on macrophage functions, by means of the determination of nitric oxide (NO) production, the mRNA expression of inducible nitric oxide synthase (iNOS), Arginase-1 and FIZZ and the cytokine levels. The phagocytic activity and the activation of NF-κB in U937 reporter cells were also investigated. No cytotoxicity was observed in macrophages treated with HW-Pm (IC₅₀ > 1024 μg/mL) by the resazurin test. HW-Pm induced high levels of NO production and iNOS expression in macrophages. In contrast, HW-Pm did not induce Arginase-1 and FIZZ mRNA expressions. The mushroom extract increased TNF-α and IL-6 production and the phagocytic function in murine macrophages. It also stimulated the activation of the NF-κB promoter. The P. ostreatus mycelium extract has a potential application as a natural immune-enhancing agent, by targeting macrophage activation towards the classically activated subset and stimulating macrophage-mediated innate immune responses.

A water-soluble selenium-enriched polysaccharide produced by Pleurotus ostreatus: Purification, characterization, antioxidant and antitumor activities in vitro

The development and application of new selenium-enriched polysaccharides has become a critical topic in recent years. In this study, a natural selenium-enriched polysaccharide fraction (Se-POP-21) produced by Pleurotus ostreatus was purified, characterized, and investigated the antioxidant and antitumor activities in vitro. The Se-POP-21 was mainly composed of mannose, glucose, galactose and arabinose, with a molar ratio of 18.01:2.40:26.15:7.34, of which molecular weight was 15,888 Da and the selenium content was 5.31 μg/g. Spectral analysis demonstrated that Se-POP-21 represented a non-triple helix pyranopolysaccharide and selenium occurred in the form of C-O-Se and SeO. Molecular size and morphology studies showed that Se-POP-21 exhibited a spherical shape with a particle size distribution between 100 and 200 nm, even though Se-POP-21 aggregates were also found with a size between 500 and 600 nm. In addition, Se-POP-21 showed strong scavenging capacity to DPPH and hydroxyl radical. More, cell experiments showed that Se-POP-21 could reduce viability of A549, SKOV3, HepG2 and MCF-7 cells, induce apoptosis and inhibit metastasis of A549 cells. A potential mechanism was that Se-POP-21 inhibited the epithelial-to-mesenchymal transition of cancer cells. Se-POP-21 featured no significant effect on normal cells. Se-POP-21 showed great potential to develop into a natural antioxidant or low-toxic antitumor drug.

A review on valorization of oyster mushroom and waste generated in the mushroom cultivation industry

A review of valorization of oyster mushroom species and waste generated in the mushroom cultivation is presented, with a focus on the cultivation and valorization techniques, conditions, current research status and particularly the hazard mitigation and value-added recovery of the waste mushroom substrate (WMS) - an abundant waste in mushroom cultivation industry. Based on the studies reviewed, the production rate of the present mushroom industry is inadequate to meet market demands. There is a need for the development of new mushroom cultivation methods that can guarantee an increase in mushroom productivity and quality (nutritional and medicinal properties). This review shows that the cylindrical baglog cultivation method is more advantageous compared with the wood tray cultivation method to improve the mushroom yield and cost efficiency. Approximately 5 kg of potentially hazardous WMS (spreading diseases in mushroom farm) is generated for production of 1 kg of mushroom. This encourages various valorization of WMS for use in agricultural and energy conversion applications, mainly as biocompost, plant growing media, and bioenergy. The use of WMS as biofertilizer has shown desirable performance compared to conventional chemical fertilizer, whilst the use of WMS as energy feedstock could produce cleaner bioenergy sources compared to conventional fuels.

Occurrence and possible roles of polysaccharides in fungi and their influence on the development of new technologies

The article summarizes the roles of polysaccharides in the biology of fungi and their relationship in the development of new technologies. The comparative approach between the evolution of fungi and the chemistry of glycobiology elucidated relevant aspects about the role of polysaccharides in fungi. Also, based on the knowledge of fungal glycobiology, it was possible to address the development of new technologies, such as the production of new anti-tumor drugs, vaccines, biomaterials, and applications in the field of robotics. We conclude that polysaccharides activate pathways of apoptosis, secretion of pro-inflammatory substances, and macrophage, inducing anticancer activity. Also, the activation of the immune system, which opens the way for the production of vaccines. The development of biomaterials and parts for robotics is a promising and little-explored field. Finally, the article is multidisciplinary, with a different and integrated approach to the role of nature in the sustainable development of new technologies.

Structural characterization of phosphorylated Pleurotus ostreatus polysaccharide and its hepatoprotective effect on carbon tetrachloride-induced liver injury in mice

This study aimed to explore the basic structural features of phosphorylated Pleurotus ostreatus polysaccharide (PPOP) and study the protective effect of PPOP on liver injury induced by carbon tetrachloride in male Kunming mice. The phosphorylated polysaccharide was prepared from the natural polysaccharide extracted from Pleurotus ostreatus (POP). The structures of PPOP and POP were characterized by FT-IR, ESEM spectroscopy, and Congo red test. Chemical composition analysis revealed that PPOP was mainly composed of rhamnose, galacturonic acid, and xylose in a molar ratio of 0.10: 1.98: 1.00. Structural analysis indicated that PPOP had multi-strand structure and the absorption peaks of PO and P-O-C. Furthermore, animal experiments showed that the hepatoprotective effect of PPOP against liver injury was reflected by decreasing the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total cholesterol, trilaurin, and low-density lipoprotein cholesterol in the serum, increasing the content of high-density lipoprotein cholesterol and albumin in blood, reducing the content of malondialdehyde and promoting the activity of antioxidant enzymes in liver. PPOP exhibited stronger hepatoprotective effect and antioxidant activity in vivo than POP. The final results indicated that PPOP could be used in the treatment of chemical-induced hepatotoxicity based on the above biological research.

Nephroprotective effect of Pleurotus ostreatus extract against cadmium chloride toxicity in rats

Cadmium, present in the environment, accumulates in different organs of animals and humans, and has deleterious effects on the kidney. In this study, we investigated the protective effects of the methanolic extract of Pleurotus ostreatus in comparison with silymarin on renal function in cadmium-intoxicated rats for five days. Rats intraperitoneally injected with cadmium chloride (1 mg/kg). These rats were treated with either P. ostreatus extract (200 mg/kg) or silymarin to investigate the protective effects of the extract. Cadmium treatment induced significant histopathological impairments and increased cadmium levels, DNA fragmentation, and renal oxidative stress. However, treatment with P. ostreatus extract or silymarin improved the pathology, reduced the level of cadmium in renal tissue, and restored DNA fragmentation. In addition, a significant reduction in lipid peroxidation and reactive oxygen species levels, and a significant increase in the levels of glutathione and catalase activity were observed. Thus, protective effects of P. ostreatus extract to its components. Chromatographic analysis of the P. ostreatus confirmed the presence of five phenolics (gallic acid, chlorogenic acid, catechin, propyl gallate, and cinnamic acid) that exhibit strong antioxidant properties as free radical scavengers. Therefore, our findings demonstrate that treatment with P. ostreatus extract protects against cadmium-induced nephrotoxicity in female rats.

Inhibitory Effect of Hydroxysafflor Yellow B on the Proliferation of Human Breast Cancer MCF-7 Cells

BACKGROUND

A recent patent has been issued for hydroxysafflor yellow A (HSYA) as a drug to prevent blood circulation disorders. Hydroxysafflor yellow B (HSYB), an isomer of HSYA with antioxidative effects, has been isolated from the florets of Carthamus tinctorius. The effects of HSYB on the proliferation of cancer cells and its mechanism of action have not been investigated.

OBJECTIVE

The aims of this study were to investigate the anti-cancer effects and the molecular mechanism of HSYB for breast cancer MCF-7 cells.

METHODS

MTT assays and colony formation assays were used to assess the survival and proliferation of MCF-7 cells, respectively. Hoechst 33258 and flow cytometry were used to measure cell apoptosis and flow cytometry to determine effects on the cell cycle. Western blots were used to measure protein levels.

RESULTS

Treatment with HSYB reduced survival and proliferation of human breast cancer MCF-7 cells in a dose-dependent manner. Furthermore, HSYB arrested the MCF-7 cell cycle at the S phase and downregulated cyclin D1, cyclin E, and CDK2. Compared with a control group, HSYB suppressed the protein levels of p-PI3K, PI3K, AKT, and p-AKT in MCF-7 cells. In addition, HSYB decreased the levels of Bcl- 2, increased the levels of Bax, cleaved caspase-3 and caspase-9, and subsequently induced MCF-7 cell apoptosis.

CONCLUSION

These data demonstrate that HSYB arrests the MCF-7 cell cycle at the S phase and induces cell apoptosis. Patent US20170246228 indicates that HSYB can be potentially used for the prevention and treatment of human breast cancer.

Macrophage activation by edible mushrooms is due to the collaborative interaction of toll-like receptor agonists and dectin-1b activating beta glucans derived from colonizing microorganisms

Research supports the theory that the microbiome of plants and mushrooms produce potent activators of pathogen recognition receptors which are principal contributors to the stimulation of macrophages. We have previously reported that the in vitro macrophage stimulatory activity of water-soluble extracts from 13 different types of edible mushrooms is predominantly due to bacterial components originating from the naturally occurring bacterial communities within these materials. The purpose of the current study was to further investigate the bacterial-dependent activity of the water-soluble extracts and assess whether these 13 types of mushrooms contain water-insoluble beta glucans that activate the dectin-1b signaling pathway. Activity of the water-soluble extracts was predominantly due to Toll-like receptor 2 (TLR2) and TLR4 agonists. For dectin-1b-dependent activity (indicative of water-insoluble beta glucans), culinary mushrooms (Agaricus bisporus varieties) were essentially inactive, whereas most of the medicinal mushrooms (Lentinula edodes, Grifola frondosa, Hypsizygus marmoreus varieties, Flammulina velutipes) exhibited potent activation. A. bisporus samples with no detectable dectin-1b-dependent activity had yeast colony forming units that were 687 times lower than L. edodes exhibiting high activity, indicating that the active insoluble beta glucans are derived from colonizing yeast. In addition, co-stimulation of macrophages with the TLR agonists and insoluble beta glucan was found to result in a synergistic enhancement of in vitro cytokine production. Taken together, these findings indicate that the in vitro macrophage activating potential of edible mushrooms is due to the collaborative interaction of water-soluble TLR agonists (derived from colonizing bacteria) and water-insoluble beta glucans (derived from colonizing yeast).

Polysaccharides of mushroom Pleurotus spp.: New extraction techniques, biological activities and development of new technologies

The biodiversity of mushrooms Pleurotus spp. is impressive due to its complexity and diversity related to the composition of chemical structures such as polysaccharides, glycoproteins and secondary metabolites such as alkaloids, flavonoids and betalains. Recent studies of polysaccharides and their structural elucidation have helped to direct research and development of technologies related to pharmacological action, production of bioactive foods and application of new, more sophisticated extraction tools. The diversity of bioactivities related to these biopolymers, their mechanisms and routes of action are constant focus of researches. The elucidation of bioactivities has helped to formulate new vaccines and targeted drugs. In this context, in terms of polysaccharides and the diversity of mushrooms Pleurotus spp., this review seeks to revisit the genus, making an updated approach on the recent discoveries of polysaccharides, new extraction techniques and bioactivities, emphasising on their mechanisms and routes in order to update the reader on the recent technologies related to these polymers.

Characterization and anti-tumor bioactivity of astragalus polysaccharides by immunomodulation

Astragalus polysaccharide (APS) has attracted growing interests in the field of anti-cancer by direct killing effect and improving immune function. In this study, the structure and composition of APS was determined, following the evaluation of in vitro and in vivo anti-tumor activity of APS targeted macrophages and host immune system based on immunoregulated strategy. The results indicated that APS had no direct cytotoxicity against 4T1 cells, but APS mediated macrophages could significantly inhibit the growth of 4T1 cells by the induction of cell cycle arrest (G2 phase) and cell apoptosis. APS mediated macrophages promoted the apoptosis of 4T1 cells mainly through the mitochondrial apoptosis pathway. The in vivo findings demonstrated that APS could markedly improve the thymus index and spleen index, and restore the structure of the damaged thymus and spleen tissue. APS could significantly enhance the proliferation of spleen lymphocytes and increase phagocytosis of peritoneal macrophages in mice. Furthermore, APS was capable of up-regulating the expression of IL-2, TNF-α and IFN-γ in peripheral blood. APS combined with 5-FU could improve the anti-tumor effect accompanied by the immunosuppressive alleviation of 5-FU on immune system, which may be suitable as an immune adjuvant for chemotherapy.

Immunomodulatory, antioxidant and intestinal morphology-regulating activities of alfalfa polysaccharides in mice

The effects of alfalfa polysaccharides (APS) on immunomodulatory and antioxidant functions, as well as intestinal morphology were investigated in vivo in this study. Sixty-four mice were randomly divided into four groups and administered 0, 200, 400 or 800 mg/kg/d body weight APS via gavage for 28 days. The blood parameters and metabolites, viscera indices, antioxidant enzyme activities and intestinal morphology were measured. The results showed that the oral administration of APS improved the immune functions of mice, significantly enhanced the white blood cells and lymphocyte counts, and led to improvements in spleen and thymus indices. APS exhibited significant antioxidant activity by enhancing total antioxidant capacity, superoxide dismutase and glutathione peroxidase activities in heart, kidney and liver, and decreasing the malondialdehyde levels of heart and liver. Moreover, administration of APS potently enhanced the small intestinal villous height and the villus-to-crypt ratio, and decreased the crypt depth of duodenum in mice. Therefore, we can conclude that APS possesses pronounced immunomodulatory activities, and plays an important role in the prevention of oxidative stresses and in the improvement of intestinal morphology in the immunological system in vivo. APS thus shows potential for the development as an effective natural immunomodulatory and antioxidant agent.

The impacts of natural polysaccharides on intestinal microbiota and immune responses – a review

This paper presents a comprehensive review of the impacts of natural polysaccharides on gut microbiota and immune responses as well as their interactions.

Alcohol-soluble polysaccharide from Astragalus membranaceus: Preparation, characteristics and antitumor activity

The alcohol-soluble polysaccharide (ASP) was extracted from Astragalus membranaceus, and their preliminary structural characteristics and in vivo antitumor activity were investigated in this study. The contents of total sugar, protein and uronic acid in ASP was 92.04%, 0.51% and 1.42%, respectively. FTIR and IC results indicated that ASP (about 2.1 × 10³ Da) was a neutral polysaccharide composed of arabinose, galactose, glucose and mannose (molar ratio: 1.00:0.98:3.01:1.52) with pyranose ring and α-type glycosidic linkages. Besides, ASP could significantly inhibit the growth of H22 heptoma cells in vivo via improving the levels of serum cytokines (TNF-α, IL-2 and IFN-γ) and activities of immune cells (macrophages, lymphocytes and NK cells), thereby inducing tumor cell apoptosis and attenuating their accessional damages. These results suggested that ASP may serve as a novel potential antitumor agent in the future.

Extraction of a Novel Cold-Water-Soluble Polysaccharide from Astragalus membranaceus and Its Antitumor and Immunological Activities

The polysaccharides of Astragalus membranaceus have received extensive study and attention, but there have been few reports on the extraction of these polysaccharides using cold water (4 °C). In this study, we fractionated a novel cold-water-soluble polysaccharide (cAMPs-1A) from Astragalus membranaceus with a 92.00% carbohydrate content using a DEAE-cellulose 52 anion exchange column and a Sephadex G-100 column. Our UV, Fourier-transform infrared spectroscopy (FTIR), high-performance gel permeation chromatography, and ion chromatography analysis results indicated the monosaccharide composition of cAMPs-1A with 1.23 × 10⁴ Da molecular weight to be fucose, arabinose, galactose, glucose, and xylose, with molar ratios of 0.01:0.06:0.20:1.00:0.06, respectively. The UV spectroscopy detected no protein and nucleic acid in cAMPs-1A. We used FTIR analysis to characterize the α-d-pyranoid configuration in cAMPs-1A. In addition, we performed animal experiments in vivo to evaluate the antitumor and immunomodulatory effects of cAMPs-1A. The results suggested that cAMPs-1A oral administration could significantly inhibit tumor growth with the inhibitory rate of 20.53%, 36.50% and 44.49%, respectively, at the dosage of 75,150, and 300 mg/kg. Moreover, cAMPs-1A treatment could also effectively protect the immune organs, promote macrophage pinocytosis, and improve the percentages of lymphocyte subsets in the peripheral blood of tumor-bearing mice. These findings demonstrate that the polysaccharide cAMPs-1A has an underlying application as natural antitumor agents.

A Preclinical Evaluation of the Antitumor Activities of Edible and Medicinal Mushrooms: A Molecular Insight

Cancer is the leading cause of morbidity and mortality around the globe. For certain types of cancer, chemotherapy drugs have been extensively used for treatment. However, severe side effects and the development of resistance are the drawbacks of these agents. Therefore, development of new agents with no or minimal side effects is of utmost importance. In this regard, natural compounds are well recognized as drugs in several human ailments, including cancer. One class of fungi, “mushrooms,” contains numerous compounds that exhibit interesting biological activities, including antitumor activity. Many researchers, including our own group, are focusing on the anticancer potential of different mushrooms and the underlying molecular mechanism behind their action. The aim of this review is to discuss PI3K/AKT, Wnt-CTNNB1, and NF-κB signaling pathways, the occurrence of genetic alterations in them, the association of these aberrations with different human cancers and how different nodes of these pathways are targeted by various substances of mushroom origin. We have given evidence to propose the therapeutic attributes and possible mode of molecular actions of various mushroom-originated compounds. However, anticancer effects were typically demonstrated in in vitro and in vivo models and very limited number of studies have been conducted in the human population. It is our belief that this review will help the research community in designing concrete preclinical and clinical studies to test the anticancer potential of mushroom-originated compounds on different cancers harboring particular genetic alteration(s).

Purification, antitumor and immunomodulatory activity of polysaccharides from soybean residue fermented with Morchella esculenta

Crude polysaccharides (MPS) from soybean residue fermented with Morchella esculenta were extracted and purified by DEAE Sephadex A-50 chromatography and Sephadex G-100 size-exclusion chromatography in sequence. Three main fractions MP-1, MP-3 and MP-4 were obtained during the purification steps. The recovery rates based on MPS used were 26.2%, 29.1% and 18.7% for MP-1, MP-3 and MP-4 respectively. The monosaccharide composition, ultraviolet spectrum, infrared spectrum and NMR of the three fractions were analyzed. Furthermore, the influence of polysaccharides fractions upon activation of macrophage cells (RAW 264.7), antitumor activities of the human hepatocellular cell line (HepG-2) and human cervical carcinoma cells (Hela) in vitro were evaluated. The results indicated that the proliferation of MP-3 on RAW 264.7 was 313.57% at 25μg/mL, which is high while MP-1 had a higher growth inhibition effect on HepG-2 cells of 68.01% at concentration of 50μg/mL. The fractions of MP-1, MP-3 and MP-4 induced apoptosis in HepG-2 cells and Hela cells by arresting cell cycle progression at the G0/G1 phase. These findings suggest that the purified polysaccharides fractions may be a potent candidate for human hepatocellular and cervical carcinoma treatment and prevention in functional foods and pharmacological fields.

Bacterial components are the major contributors to the macrophage stimulating activity exhibited by extracts of common edible mushrooms

Recent studies have indicated that a major contributor to the innate immune enhancing properties of some medicinal plants is derived from the cell wall components of bacteria colonizing these plants. The purpose of the current study was to assess if the bacteria present within edible and medicinal mushrooms substantially contribute to the innate immune stimulating potential of these mushrooms. Whole mushrooms from thirteen types of edible fungi and individual parts from Agaricus bisporus were analyzed for in vitro macrophage activation as well as bacterial lipopolysaccharides (LPS) content, cell load, and community composition. Substantial variation between samples was observed in macrophage activation (over 500-fold), total bacterial load (over 200-fold), and LPS content (over 10 million-fold). Both LPS content (ρ = 0.832, p < 0.0001) and total bacterial load (ρ = 0.701, p < 0.0001) correlated significantly with macrophage activation in the whole mushroom extracts. Extract activity was negated by treatment with NaOH, conditions that inactivate LPS and other bacterial components. Significant correlations between macrophage activation and total bacterial load (ρ = 0.723, p = 0.0001) and LPS content (ρ = 0.951, p < 0.0001) were also observed between different tissues of Agaricus bisporus. Pseudomonas and Flavobacterium were the most prevalent genera identified in the different tissue parts and these taxa were significantly correlated with in vitro macrophage activation (ρ = 0.697, p < 0.0001 and ρ = 0.659, p = 0.0001, respectively). These results indicate that components derived from mushroom associated bacteria contribute substantially to the innate immune enhancing activity exhibited by mushrooms and may result in similar therapeutic actions as reported for ingestion of bacterial preparations such as probiotics.

Immunomodulatory and Antioxidant Effects of Polysaccharides from Gynostemma pentaphyllum Makino in Immunosuppressed Mice

The immunomodulatory and antioxidant activities of crude polysaccharides extracted from Gynostemma pentaphyllum Makino (GPMPP) were investigated. GPMPP was composed of rhamnose, arabinose, xylose, mannose, glucose and galactose in the molar ratio of 1.39:3.76:1.00:1.64:4.98:5.88. In vivo studies showed GPMPP significantly increased the spleen and thymus indices, activated the macrophage phagocytosis and NK cells, and exhibited activity on none or Con A/LPS-stimulated splenocytes in a dose-dependent manner in C57BL/6 mice. Moreover, GPMPP elevated CD4⁺ T lymphocyte counts as well as the CD4⁺/CD8⁺ ratio dose-dependently, and it increased IL-2 level in the sera and spleen of Cy-immunosuppressed mice. Furthermore, GPMPP significantly increased the SOD, GSH-Px, T-AOC, GSH and CAT level, and decreased the MDA level. The results showed that GPMPP might play an important role in prevention of oxidative damage in immunological system. These findings indicate GPMPP has immunomodulatory activity in vivo and seems to be an effective natural immunomodulatory agent.

The structure of mushroom polysaccharides and their beneficial role in health

Mushroom is a kind of fungus that has been popular for its special flavour and renowned biological values. The polysaccharide contained in mushroom is regarded as one of the primary bioactive constituents and is beneficial for health. The structural features and bioactivities of mushroom polysaccharides have been studied extensively. It is believed that the diverse biological bioactivities of polysaccharides are closely related to their structure or conformation properties. In this review, the structural characteristics, conformational features and bioactivities of several mushroom polysaccharides are summarized, and their beneficial mechanisms and the relationships between their structure and bioactivities are also discussed.

β-glucans from Coriolus versicolor protect mice against S. typhimurium challenge by activation of macrophages

The effects of β-glucans from Coriolus versicolor (CVP), which are extracted from a well-known immune stimulator C. versicolor, have been demonstrated extensively in vitro and in vivo. However, until now, the phagocytic activity has not been elucidated. Hence, the objective of the present study was to identify the antibacterial activity of CVP or CVP-treated macrophages by an analysis of cell cytotoxicity, phagocytic activity, intracellular bacterial survival, macrophage activation, production of nitric oxide (NO) and expression of inducible nitric oxide synthase (iNOS) in CVP-treated macrophages using flow cytometry, RT-PCR, a gentamicin protection assay, a Nitric oxide assay and an iNOS enzymatic activity assay. The results indicate that CVP-treated macrophages can phagocytize and kill bacteria, probably due to the production of NO and iNOS. More importantly, CVP-treated macrophages are effective at protecting mice against the challenge of Salmonella typhimurium. The results of this study suggest that the antibacterial effects of CVP are probably caused by the activation of innate immune cells, especially macrophages, because the activated macrophage produces NO, which kills bacteria. These phenomena indicate the possibility of CVP as a potential alternative for antibiotics against resistant bacteria.