Structural elucidation and immunostimulatory activity of polysaccharide isolated by subcritical water extraction from Cordyceps militaris

Optimization of Fermentation Conditions of Cordyceps militaris and In Silico Analysis of Antifungal Property of Cordycepin Against Plant Pathogens

Cordyceps militaris, a medicinal fungus, has gained considerable attention owing to its potential health benefits, notably the production of bioactive compounds such as cordycepin. Cordycepin possesses significant antifungal, antibacterial, and antiviral properties. The present study focused on optimizing the fermentation conditions for C. militaris to boost the production of mycelia and cordycepin, alongside investigating its antifungal properties using in silico and in vitro approaches. The optimal conditions, yielding the highest cordycepin and mycelial biomass, were a temperature of 20°C and a pH range of 4-6, with glucose and sucrose as carbon sources and yeast extract and casein hydrolysate as nitrogen sources. Under these conditions, cordycepin production peaked at low pH (600-1000 mg/L) and with carbon and maltose (400-500 mg/L). The low temperature favored cordycepin production (400 mg/L), whereas casein hydrolysate as a nitrogen source boosted cordycepin yield (600 mg/L). The docking analysis indicated that cordycepin had the highest binding affinity for the tubulin beta chain 2 (-10.4 kcal/mol) compared to the fungicide tebuconazole (-7.9 kcal/mol for both targets). The in silico results were corroborated by in vitro studies, where the mycelial extract of C. militaris inhibited approximately 75% of fungal growth at a concentration of 6000 ppm. These findings suggest that optimizing fermentation conditions significantly enhances cordycepin production, and cordycepin shows antifungal solid activity, making it a promising agent for biocontrol in agriculture.

Effect of Flammulina velutipes polysaccharide on mitochondrial apoptosis in lung adenocarcinoma A549 cells

FVP is a polysaccharide extracted from Flammulina velutipes with immunomodulatory, anti-tumor, and anti-oxidation activities. In this study, we obtained the crude polysaccharide FVP-C from the water extract of Flammulina velutipes, and its main component FVP-S1 was obtained after further purification. Upon structural identification, we found that FVP-C is a neutral polysaccharide, and FVP-S1 was an acidic golden mushroom polysaccharide, consisting of glucuronic acid, xylose, and glucose. Lung adenocarcinoma (A549) was treated with FVP-S1 and FVP-C, respectively, and we found that FVP-S1 and FVP-C inhibited the proliferation and migration ability of tumor cells, as well as changed the morphology of the tumor cells and caused chromosome sheteropythosis, among which FVP-S1 had the best inhibition effect. The results of flow cytometry experiments and mitochondrial membrane potential, RT-qPCR, and Western blot showed that FVP-S1 and FVP-C were able to decrease the mitochondrial membrane potential, increase the expression level of apoptotic proteins Casepase-3 and Casepase-9 proteins, and at the same time, increase the ratio of Bax and Bcl-2, which promoted apoptosis of tumor cells. In conclusion, these data indicated that FVP-S1 and FVP-C were able to induce apoptosis in A549 cells through the mitochondrial pathway, which played an important role in inhibiting tumor cells.

Structural Elucidation and Anti-Tumor Activity of a Polysaccharide (CP2-S) from Cordyceps militaris Fruit Bodies

A polysaccharide (CP2-S), consisting of glucose with a weight average molecular weight of 5.9 × 106, was purified from the fruit bodies of Cordyceps militaris. In this work, the corresponding structure and anti-tumor activity in vivo were investigated. Methylation and NMR analysis revealed that CP2-S was composed of a →4)-α-D-Glcp-(1→ backbone with partial substitution occurring at O-6 by T-linked α-D-Glcp in every ten residues, which has not been reported in previous reports. In vivo anti-tumor experiments showed that CP2-S could inhibit the growth of Lewis lung carcinoma in mice. Tumor inhibition rates were 17.8%, 24.5%, and 29.5% at dosages of 12.5, 50, and 100 mg/kg/d, respectively. Compared with the cisplatin group, mice treated with CP2-S exhibited a significant increase in spleen index (increased 22.7-42.4%) and thymus index (increased 47.7-36.8%). Additionally, serum levels of IgM and IgG in tumor-bearing mice increased by approximately 6.11~10.75-folds and 1.31~1.38-folds, respectively. These findings prove that CP2-S significantly inhibited the growth of Lewis lung carcinoma through immune-enhancing activity in mice.

Effects of Defatting Pretreatment on Polysaccharide Extraction from Rambutan Seeds Using Subcritical Water: Optimization Using the Desirability Approach

Rambutan seeds are by-products generated from fruit-processing factories; the leftover seeds are buried in landfills, generating methane emissions. This work aimed to extract polysaccharides (POLS) from rambutan seeds by using subcritical water extraction (SWE). The effects of defatting pretreatment and operating parameters in SWE were investigated using a Box-Behnken design. The results show that defatting pretreatment significantly enriched the POLS yield, while it had no significant effect on the total sugar content. Using the desirability approach, the suitable feedstock for SWE was defatted rambutan seeds. The maximum desirability of 0.86 was found at a temperature range of 145-150 °C, an extraction time of 15 min, and a liquid-solid ratio of 10:1. The POLS yield and total sugar content were in the range of 52.33-55.63 g/100 g feedstock and 83.37-87.45 g/100 g POLS, respectively. The extracted POLS had an equivalent molecular weight of 413.70 kDa that could be used as an extender in plant-based products. In conclusion, the defatting pretreatment of rambutan seeds not only improved the POLS yield obtained via SWE but also generated additional lipids that could be utilized as an unconventional source of specialty fat.

Dietary Black Soldier Fly (Hermetia illucens)-Dipterose-BSF-Enhanced Zebrafish Innate Immunity Gene Expression and Resistance to Edwardsiella tarda Infection

Dietary management using immunostimulants to protect fish health and prevent bacterial infection is widely practiced. Many insect species possess various bioactive substances that can improve animal health. We previously identified several bioactive polysaccharides derived from insects, including dipterose-BSF from black soldier fly (Hermetia illucens) larvae; this can stimulate innate immunity in mammalian macrophage RAW264.7 cells. However, the effect of dietary dipterose-BSF on the immune system of teleosts remains unclear. Here, we analyzed the immune status of zebrafish (Danio rerio) after 14 days of dietary inclusion of dipterose-BSF (0.01, 0.1, and 1 µg/g), followed by an immersion challenge using Edwardsiella tarda. To identify changes in the transcriptional profile induced by dipterose-BSF, we performed RNA-sequencing analyses of the liver and intestine. Differentially expressed genes were investigated, with both organs showing several upregulated genes, dominated by nuclear factor and tumor necrosis factor family genes. Gene Ontology analysis revealed several terms were significantly higher in the experimental group compared with the control group. Challenge tests suggested that dietary dipterose-BSF had some positive effects on disease resistance in fish, but these effects were not pronounced.

A review on polysaccharide biosynthesis in Cordyceps militaris

Cordyceps militaris (C. militaris) is an edible parasitic fungus with medicinal properties. Its bioactive polysaccharides are structurally diverse and exhibit various metabolic and biological activities, including antitumor, hypoglycemic, antioxidant, hypolipidemic, anti-inflammatory, immunostimulatory, and anti-atherosclerotic effects. These properties make C. militaris-derived polysaccharides a promising candidate for future development. Recent advancements in microbial fermentation technology have enabled successful laboratory cultivation and extraction of these polysaccharides. These polysaccharides are structurally diverse and exhibit various biological activities, such as immunostimulatory, antioxidant, antitumor, hypolipidemic, and anti-atherosclerotic effects. This review aims to summarize the structure and production mechanisms of polysaccharides from C. militaris, covering extraction methods, key genes and pathways involved in biosynthesis, and fermentation factors that influence yield and activity. Furthermore, the future potential and challenges of utilizing polysaccharides in the development of health foods and pharmaceuticals are addressed. This review serves as a valuable reference in the fields of food and medicine, and provides a theoretical foundation for the study of polysaccharides.

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.

Physicochemical characterization, rheological properties, and hypolipidemic and antioxidant activities of compound polysaccharides in Chinese herbal medicines by fractional precipitation

This study aimed to investigate the effects of different compound polysaccharides (CPs) extracted from Folium nelumbinis, Fructus crataegi, Fagopyrum tataricum, Lycium barbarum, Semen cassiae, and Poria cocos (w/w, 2:4:2:1:1.5:1) by gradient ethanol precipitation on the physicochemical properties and biological activities. Three CPs (CP50, CP70, and CP80) were obtained and comprised rhamnose, arabinose, xylose, mannose, glucose, and galactose in different proportions. The CPs contained different amounts of total sugar, uronic acid, and proteins. These also exhibited different physical properties, including particle size, molecular weight, microstructure, and apparent viscosity. Scavenging abilities of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 1,1'-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals of CP80 were more potent compared to those of the other two CPs. Furthermore, CP80 significantly increased serum levels of high-density lipoprotein cholesterol (HDL-C) and lipoprotein lipase (LPL), and hepatic lipase (HL) activity in the liver, while decreasing the serum levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C), along with LPS activity. Therefore, CP80 may serve as a natural novel lipid regulator in the field of medicinal and functional food.

Subcritical Water Enhanced with Deep Eutectic Solvent for Extracting Polysaccharides from Lentinus edodes and Their Antioxidant Activities

In the present study, subcritical water extraction (SWE) assisted with deep eutectic solvent (DES) is used to extract Lentinus edodes polysaccharides (LEP). In addition, the antioxidant activity of the polysaccharide samples was also investigated. Based on a single factor test and response surface test, the optimal extraction factors were a liquid–solid solvent of 40:1 mL/g, extraction temperature of 147.23 °C, water content of 39.76% and extraction time of 17.58 min. Under these extraction conditions, the yield of LEP was 6.26 ± 0.08%. Compared with the SWE and hot water extraction (HWE), it improved by 19.24% and 17.01%, respectively. In addition, the results of monosaccharide composition, molecular weight, FT-IR, UV and SEM confirmed that the extracts had the features of polysaccharides. Interestingly, the polysaccharides obtained with the SWE assisted with the DES procedure showed a higher DPPH scavenging activity, hydroxyl radical scavenging activity and hydrogen peroxide scavenging activity, which indicated that the polysaccharides with this method had a stronger antioxidant activity. These findings demonstrated that the SWE-assisted DES is a strong method to obtain polysaccharides from Lentinus edodes for food, biopharmaceutical and other industrial production.

Structural Elucidation and Activities of Cordyceps militaris-Derived Polysaccharides: A Review

Cordyceps militaris is a parasitic edible fungus and has been used as tonics for centuries. Polysaccharides are a major water-soluble component of C. militaris. Recently, C. militaris-derived polysaccharides have been given much attention due to their various actions including antioxidant, anti-inflammatory, anti-tumor, anti-hyperlipidemic, anti-diabetic, anti-atherosclerotic, and immunomodulatory effects. These bioactivities are determined by the various structural characteristics of polysaccharides including monosaccharide composition, molecular weight, and glycosidic linkage. The widespread use of advanced analytical analysis tools has greatly improved the elucidation of the structural characteristics of C. militaris-derived polysaccharides. However, the methods for polysaccharide structural characterization and the latest findings related to C. militaris-derived polysaccharides, especially the potential structure-activity relationship, have not been well-summarized in recent reviews of the literature. This review will discuss the methods used in the elucidation of the structure of polysaccharides and structural characteristics as well as the signaling pathways modulated by C. militaris-derived polysaccharides. This article provides information useful for the development of C. militaris-derived polysaccharides as well as for investigating other medicinal polysaccharides.

Advancement of biorefinery-derived platform chemicals from macroalgae: a perspective for bioethanol and lactic acid

The extensive growth of energy and plastic demand has raised concerns over the depletion of fossil fuels. Moreover, the environmental conundrums worldwide integrated with global warming and improper plastic waste management have led to the development of sustainable and environmentally friendly biofuel (bioethanol) and biopolymer (lactic acid, LA) derived from biomass for fossil fuels replacement and biodegradable plastic production, respectively. However, the high production cost of bioethanol and LA had limited its industrial-scale production. This paper has comprehensively reviewed the potential and development of third-generation feedstock for bioethanol and LA production, including significant technological barriers to be overcome for potential commercialization purposes. Then, an insight into the state-of-the-art hydrolysis and fermentation technologies using macroalgae as feedstock is also deliberated in detail. Lastly, the sustainability aspect and perspective of macroalgae biomass are evaluated economically and environmentally using a developed cascading system associated with techno-economic analysis and life cycle assessment, which represent the highlights of this review paper. Furthermore, this review provides a conceivable picture of macroalgae-based bioethanol and lactic acid biorefinery and future research directions that can be served as an important guideline for scientists, policymakers, and industrial players.

Graphical abstract

Cordyceps militaris as a Bio Functional Food Source: Pharmacological Potential, Anti-Inflammatory Actions and Related Molecular Mechanisms

Cordyceps militaris (C. militaris) is a medicinal mushroom possessing a variety of biofunctionalities. It has several biologically important components such as polysaccharides and others. The diverse pharmacological potential of C. militaris has generated interest in reviewing the current scientific literature, with a particular focus on prevention and associated molecular mechanisms in inflammatory diseases. Due to rising global demand, research on C. militaris has continued to increase in recent years. C. militaris has shown the potential for inhibiting inflammation-related events, both in in vivo and in vitro experiments. Inflammation is a multifaceted biological process that contributes to the development and severity of diseases, including cancer, colitis, and allergies. These functions make C. militaris a suitable functional food for inhibiting inflammatory responses such as the regulation of proinflammatory cytokines. Therefore, on the basis of existing information, the current study provides insights towards the understanding of anti-inflammatory activity-related mechanisms. This article presents a foundation for clinical use, and analyzes the roadmap for future studies concerning the medical use of C. militaris and its constituents in the next generation of anti-inflammatory drugs.

New Insights Into the Biosynthesis of Typical Bioactive Components in the Traditional Chinese Medicinal Fungus Cordyceps militaris

Cordyceps militaris, a traditional medicinal ingredient with a long history of application in China, is regarded as a high-value fungus due to its production of various bioactive ingredients with a wide range of pharmacological effects in clinical treatment. Several typical bioactive ingredients, such as cordycepin, D-mannitol, cordyceps polysaccharides, and N⁶-(2-hydroxyethyl)-adenosine (HEA), have received increasing attention due to their antitumor, antioxidant, antidiabetic, radioprotective, antiviral and immunomodulatory activities. Here, we systematically sorted out the latest research progress on the chemical characteristics, biosynthetic gene clusters and pathways of these four typical bioactive ingredients. This summary will lay a foundation for obtaining low-cost and high-quality bioactive ingredients in large amounts using microbial cell factories in the future.

Isolation and immune activity of a new acidic Cordyceps militaris exopolysaccharide

A new type of acidic exopolysaccharide (AESP-II) was extracted and separated from the fermentation broth of Cordyceps militaris (C. militaris), which was further purified to elucidate its structural characteristics and immunological activity. AESP-II was confirmed to be an acidic pyranose with a molecular weight of 61.52 kDa, which consisted of mannose, glucuronic acid, rhamnose, galactose acid, N-acetyl-galactosamine, glucose, galactose and arabinose with a molar ratio of 1.07: 5.38: 1: 3.14: 2.23: 15: 6.09: and 4.04. Animal experiment results verified that AESP-II can significantly promote the proliferation of spleen T and B lymphocytes in mice with immune injury caused by cyclophosphamide (CTX). In particular, the promotion of B lymphocytes presented a dose-effect relationship. In addition, the levels of the cytokines IL-2, IL-4, and IFN-γ, which are mainly secreted by T lymphocytes, and immunoglobulin IgG, IgM and IgA, which are mainly secreted by B lymphocytes, were increased after AESP-II treatment. The above results suggest that fluid immunity is involved in the immunomodulatory function of AESP-II. Simultaneously, AESP-II was detected significantly to promote the phosphorylation expression of p38 kinase (p38), extracellular regulated protein kinases (ERK) and c-Jun N-terminal kinase (JNK) by Western blot, further suggesting that the activation of the MAPK signaling pathway mediates the immunoregulatory function of AESP-II.

Molecular Cloning, Expression and Macrophage Activation of an Immunoregulatory Protein from Cordyceps militaris

Protein components of C. militaris have been reported to possess various biological activities. In our previous research, a Cordyceps militaris-derived immunoregulatory protein (CMIP) was naturally isolated and showed the activity of inhibiting the metastasis of breast cancer cells. This study aimed to obtain recombinant CMIP (rCMIP) using recombinant expression and elucidate its ability to activate macrophages. Recombinant CMIP showed one band at approximately 15 kDa or 30 kDa, or two bands at 15 kDa and 30 kDa, under different denaturation conditions of electrophoresis. The cell binding assay showed that rCMIP selectively binds to the surface of macrophages. After adhesion, it did not induce the apoptosis of RAW 264.7 cells, but promoted their proliferation. Moreover, rCMIP significantly induced the expression of M1 macrophage polarization-related molecules. The mean fluorescence intensity (MFI) of CD 86 was enhanced by 2.1-fold and 3.2-fold under 0.64 μM and 1.6 μM of rCMIP treatment, respectively. Cytokines typically expressed in M1 macrophages, such as TNF-α, iNOS, IL-6, CCL 4, CCL 5 and CXCL 10, were also considerably induced by rCMIP, while the expression of cytokines in typical M2 macrophages, like Arg-1, CCL17 and CCL22, were not changed or slightly decreased. Under rCMIP treatment, the release of NO was also appreciably induced. In the present study, we reported cloning, expression and functional characterization of rCMIP, which was naturally isolated from the fruiting body of C. militaris in our previous study. The data imply that rCMIP possesses immunomodulatory activity in macrophages.

Structure and immunomodulatory activity of a water-soluble α-glucan from Hirsutella sinensis mycelia

Hirsutella sinensis, the anamorph of Ophiocordyceps sinensis (syn. Cordyceps sinensis), is a great substitute for precious and rare wild Cordyceps sinensis to effectively treat a variety of lung and kidney diseases. In this study, an α-glucan (named as HSWP-2a) was obtained by hot water extraction, DEAE-cellulose separation, and Sepharose CL-6B purification from H. sinensis mycelia. Different from known α-glucans, HSWP-2a is an α-(1 → 4)-D-glucan that branched at O-6, O-3, or O-2 with a terminal 1-linked α-D-Glcp as side chain, with an average molecular weight of 870.70 kDa. Immunological tests showed that HSWP-2a could remarkably enhance the phagocytosis of macrophages and increase the production of NO, IL-1β, IL-6, and TNF-α, via activating the p38, JNK, and NF-κB signaling pathways. Moreover, HSWP-2a could significantly promote splenic lymphocyte proliferation. Taken together, HSWP-2a may be potentially utilized as a natural immunomodulatory agent.

Integrated bioinformatics analysis of the anti-atherosclerotic mechanisms of the polysaccharide CM1 from Cordyceps militaris

Cordyceps militaris is a well-known traditional Chinese medicine. Studies have demonstrated that the polysaccharides of C. militaris have various bioactivities. However, their mechanisms of action remain unclear. We previously purified a water-soluble polysaccharide CM1 from C. militaris and found that it has a cholesterol efflux improving capacity. This study further investigates the effect of CM1 in anti-atherosclerosis and its underlying mechanism in apolipoprotein E-deficient mice. Our data indicated that CM1 significantly decreased the total cholesterol and triglyceride in the plasma of mice, and decreased lipid deposition and formation of atherosclerotic plaque in a dose-dependent manner. Integrated bioinformatics analysis revealed that CM1 interacted with multiple signaling pathways, including those involved in lipid metabolism, inflammatory response, oxidoreductase activity and fluid shear stress, to exert its anti-atherosclerotic effect. Molecular technology analysis showed that CM1 enhanced the expression of proteins involved in lipid metabolism, reduced the expression of intercellular adhesion molecule-1 and tumor necrosis factor-α in the aorta, and decreased the content of oxidative products by enhancing the activities of antioxidant enzymes. Microarray analysis and biochemical data indicated that CM1 can improve lipid metabolism, reduce inflammation and oxidative stress. Taken together, CM1 could be used for the treatment of hyperlipidemia and atherosclerotic cardiovascular diseases.

Cordyceps militaris: An Overview of Its Chemical Constituents in Relation to Biological Activity

Cordyceps spp. mushrooms have a long tradition of use as a natural raw material in Asian ethnomedicine because of their adaptogenic, tonic effects and their ability to reduce fatigue and stimulate the immune system in humans. This review aims to present the chemical composition and medicinal properties of Cordyceps militaris fruiting bodies and mycelium, as well as mycelium from in vitro cultures. The analytical results of the composition of C. militaris grown in culture media show the bioactive components such as cordycepin, polysaccharides, γ-aminobutyric acid (GABA), ergothioneine and others described in the review. To summarize, based on the presence of several bioactive compounds that contribute to biological activity, C. militaris mushrooms definitely deserve to be considered as functional foods and also have great potential for medicinal use. Recent scientific reports indicate the potential of cordycepin in antiviral activity, particularly against COVID-19.

Subcritical Water Extraction of Natural Products

Subcritical water refers to high-temperature and high-pressure water. A unique and useful characteristic of subcritical water is that its polarity can be dramatically decreased with increasing temperature. Therefore, subcritical water can behave similar to methanol or ethanol. This makes subcritical water a green extraction fluid used for a variety of organic species. This review focuses on the subcritical water extraction (SBWE) of natural products. The extracted materials include medicinal and seasoning herbs, vegetables, fruits, food by-products, algae, shrubs, tea leaves, grains, and seeds. A wide range of natural products such as alkaloids, carbohydrates, essential oil, flavonoids, glycosides, lignans, organic acids, polyphenolics, quinones, steroids, and terpenes have been extracted using subcritical water. Various SBWE systems and their advantages and drawbacks have also been discussed in this review. In addition, we have reviewed co-solvents including ethanol, methanol, salts, and ionic liquids used to assist SBWE. Other extraction techniques such as microwave and sonication combined with SBWE are also covered in this review. It is very clear that temperature has the most significant effect on SBWE efficiency, and thus, it can be optimized. The optimal temperature ranges from 130 to 240 °C for extracting the natural products mentioned above. This review can help readers learn more about the SBWE technology, especially for readers with an interest in the field of green extraction of natural products. The major advantage of SBWE of natural products is that water is nontoxic, and therefore, it is more suitable for the extraction of herbs, vegetables, and fruits. Another advantage is that no liquid waste disposal is required after SBWE. Compared with organic solvents, subcritical water not only has advantages in ecology, economy, and safety, but also its density, ion product, and dielectric constant can be adjusted by temperature. These tunable properties allow subcritical water to carry out class selective extractions such as extracting polar compounds at lower temperatures and less polar ingredients at higher temperatures. SBWE can mimic the traditional herbal decoction for preparing herbal medication and with higher extraction efficiency. Since SBWE employs high-temperature and high-pressure, great caution is needed for safe operation. Another challenge for application of SBWE is potential organic degradation under high temperature conditions. We highly recommend conducting analyte stability checks when carrying out SBWE. For analytes with poor SBWE efficiency, a small number of organic modifiers such as ethanol, surfactants, or ionic liquids may be added.

Microwave Assisted Extraction and Pressurized Liquid Extraction of Sulfated Polysaccharides from Fucus virsoides and Cystoseira barbata

Sulfated polysaccharide fucoidan isolated from brown algae shows a wide range of biological activities that are significantly dependent on its chemical composition, which is closely related to the applied technique and extraction parameters. Therefore, the objective of this study was to evaluate the influence of microwave assisted extraction (MAE) and pressurized liquid extraction (PLE) parameters (solvent, temperature, time, and number of cycles) on the Fucus virsoides and Cystoseira barbata polysaccharide yield (%PS) and chemical composition (total sugar, fucose, and sulfate group). The optimal MAE parameters that resulted in the highest polysaccharide extraction from F. virsoides and C. barbata were 0.1 M H₂SO₄ for 10 min at 80 °C, while the optimal PLE parameters were 0.1 M H₂SO₄, for two cycles of 15 min at 140 °C. Furthermore, the %PS, chemical structure, molecular properties, and antioxidant activity of the F. virsoides and C. barbata polysaccharide extracts obtained with MAE, PLE, and conventional extraction (CE) performed under previously determinate optimal conditions were compared. PLE resulted in a significantly higher %PS from F. virsoides, while for C. barbata, a similar yield was achieved with CE and PLE, as well as CE and MAE, for both algae. Furthermore, the polysaccharides obtained using PLE had the highest polydispersity index, fucose, and sulfate group content, and the lowest uronic acid content; however their antioxidant activity was lower.

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.

Purification, characterization and anti-atherosclerotic effects of the polysaccharides from the fruiting body of Cordyceps militaris

Hyperlipidemia is one major cause of atherosclerosis, which is a basic pathological change of cardiovascular diseases. Polysaccharide is a water-soluble component with lipid-lowering effects. In this study, alkaline-extracted polysaccharides were obtained from the fruiting body of C. militaris. Polysaccharides were purified via anion exchange and size exclusion chromatography. Their structural characteristics were investigated via chemical and spectroscopic methods. CM3I was mainly composed of →4)α-D-Glcp(1 → glycosyls and differed from starch due to the presence of →4,6)β-D-Glcp(1 → glycosyls. CM3II was characterized by its backbone, which was composed of →4)-β-D-Manp(1 → 6)-α-D-Manp(1 → 6)-β-D-Manp(1 → linked glycosyls, and especially the presence of O-methyl. Moreover, CM3II exhibited powerful anti-atherosclerotic effects via lowering plasma lipid levels in apolipoprotein E-deficient mice. The underlying mechanisms were attributed to its promoting effect on LXRα and inhibitory effect on SREBP-2. Collectively, CM3I and CM3II are different from the previously reported polysaccharides from C. militaris, and CM3II has a potential application in hypolipidemia and anti-atherosclerosis.

A Novel Optimization of Water-Soluble Compound Polysaccharides from Chinese Herbal Medicines by Quantitative Theory and Study on Its Characterization and Antioxidant Activities

The present study optimized the extraction characterization and antioxidant activities of water-soluble compound polysaccharides (CPs) from hawthorn, lotus leaf, Fagopyrum tataricum, semen cassiae, Lycium barbarum, and Poria cocos Chinese herbal medicines that have mass ratios of 4 : 2 : 2 : 1.5 : 1 : 1. The CPs yield equation was predicted using quantitative theory, to which a maximum CPs yield of 7.18±0.24 % under the following optimal extraction conditions: a water-to-raw material ratio of 30 mL/g, an extraction temperature of 65 °C, an extraction time of 45 min, and extraction mode ultrasonic-assistant extraction. CPs were consisted of Ara, Gal, Glc, Xyl, Man, GalA and GlcA in a molar ratio of 3.1 : 2.6 : 50.6 : 1.7 : 20.4 : 17.2 : 4.2. The HPGPC profiles and FT-IR spectra implied that CPs were heterogeneous acidic polysaccharides and possessed the β-d-pyranose configuration. Congo red test, CD spectrum and SEM revealed that CPs with three helix conformation showed a flocculent, granulous or sheet-like appearance. Furthermore, the relationships between antioxidant activity and concentration of CPs displayed significant positive correlation, and the scavenging abilities for DPPH, hydroxyl radical, ABTS, superoxide-anion radical and reducing power of CPs were 93.56±2.51 %, 84.03±1.69 %, 83.29±1.93 %, 37.49±1.93 % and 0.467±0.006 at a concentration of 4.0 mg/mL. Therefore, CPs could be applied as a potential natural antioxidant in pharmaceutical or functional food fields.

Trends in the Immunomodulatory Effects of Cordyceps militaris: Total Extracts, Polysaccharides and Cordycepin

Cordyceps militaris (C. militaris) is a fungus with a long history of widespread use in folk medicine, and its biological and medicinal functions are well studied. A crucial pharmacological effect of C. militaris is immunomodulation. In this review, we catalog the immunomodulatory effects of different extracts of C. militaris, namely total extracts, polysaccharides and cordycepin. Total extracts obtained using water or 50% ethyl alcohol and polysaccharides from C. militaris were discovered to tend to promote type 1 immunity, whereas total extracts obtained using 70-80% ethyl alcohol and cordycepin from C. militaris were more likely to promote type 2 immunity. This article is the first to classify the immunomodulatory effects of different extracts of C. militaris. In addition, we discovered a relationship between different segments or extracts and differing types of immunity. This review can provide the readers a comprehensive understanding on the immunomodulatory effects of the precious folk medicine and guidance on its use for both health people and those with an immunodeficiency.

Extracellular polysaccharide biosynthesis in Cordyceps

Cordyceps is a parasitic edible fungus with a variety of metabolically active ingredients. The main active ingredient, extracellular polysaccharide (EPS), shows favourable application prospects in prevention and treatment of certain diseases. EPS extracted from different parts of various Cordyceps species can be used in health foods or medicinal preparations because of the structural diversity and multiple bioactivities. In terms of the complexity of composition and structure, researchers have speculated on the anabolic pathways of EPSs and the genes involved in the synthesis process. Studies to increase the yield of polysaccharides are limited because the synthesis pathways and anabolic regulation mechanisms of Cordyceps exopolysaccharide remain unknown. This review summarises the current researches in the yield of Cordyceps polysaccharides. A mechanism for the biosynthesis of Cordyceps polysaccharides was proposed by referring to the polysaccharide synthesis in other species. Furthermore, we also discuss the future perspective and ongoing challenges of EPS in uses of health foods and pharmaceutics.

Extraction, structural characterization, and immunobiological activity of ABP Ia polysaccharide from Agaricus bisporus

The extraction, purification, immunobiological activities, and structure of Agaricus bisporus polysaccharides (ABP) were investigated. Especially we purified and identified the polysaccharides with the highest in vitro immunobiological activity. The extraction conditions of ABP were optimized using single factor and orthogonal experiment. ABP Ia was screened after double purification with DEAE-52 and Sephadex G-200 and showed the best immunoregulatory activity. UV spectra analysis and high-performance gel permeation chromatography results indicated that the ABP Ia fraction did not contain any proteins or nucleotides and was a homogeneous polysaccharide with a relative molecular weight of 784 kDa. Gas chromatography mass spectroscopy results showed that ABP Ia was a heteropolysaccharide consisting of ribose, rhamnose, arabinose, xylose, mannose, glucose, and galactose at a molar ratio of 2.08:4.61:2.45:22.25:36.45:89.22:1.55. FT-IR and periodic acid oxidation analysis indicated that ABP Ia was an α-pyran polysaccharide composed of 1 → 2 and 1 → 4 glycosidic bonds, as well as a possible 1 → 3 glycosidic bond. Furthermore, atomic force microscopy revealed that ABP Ia polysaccharide chains twisted to form a rod-like architecture and, at a 5% concentration, aggregated into a tight structure similar to the shape of a stone forest. These findings identify ABP Ia as a potential functional food ingredient or pharmaceutical for immunoregulation.

Polysaccharides from Cordyceps miltaris cultured at different pH: Sugar composition and antioxidant activity

In the study, the β-glucan content, the primary structure and the antioxidant capacity of polysaccharides in Cordyceps militaris cultivated with different initial growth pH were evaluated. Meanwhile, the mechanism of β-glucan biosynthesis was investigated by RNA-Seq. Based on the results, C. militaris growing at an initial growth pH of 5-7 (CMsA) was distinguished from C. militaris growing at an initial growth pH of 8-9 (CMsB) and their unigenes showed the comparable expression. The mean of β-glucan content of CMsB group was 32.7% (w/w), 10% higher than that of CMsA. The results of RNA-seq showed 1088 differentially expressed genes between CMsA and CMsB groups. Furthermore, oxidative phosphorylation-related Gene ontology terms were up-regulated in CMsB groups. In addition, the results of structural analysis (FTIR spectrum, monosaccharide composition, periodate oxidation) and bioactivity evaluation speculated that C. militaris polysaccharides possessed higher β-(1 → 6)-glucan content and antioxidant activities in CMsB groups.

Enzymatic hydrolysis pretreatment for enhancing the protein solubility and physicochemical quality of Cordyceps militaris chicken soup

Chicken soup is one of the most popular Chinese-style soups due to its high nutritional value and special flavor. However, the nutrients, mainly soluble protein, in the soup are relatively low. The aim of the present work was to enhance the protein solubility and other physicochemical properties of Cordyceps militaris chicken soup by enzymatic hydrolysis pretreatment. Results indicated that the soluble protein dissolution rate and flavor nucleotides (I+G) of Cordyceps militaris chicken soup had 1.6-fold and 0.5-fold increase, respectively, after enzymatic hydrolysis pretreatment. Not only the contents of total amino acids (TAA) and essential amino acids (EAA) in Cordyceps militaris chicken soup significantly increased, the organoleptic quality was also markedly improved after the enzymatic hydrolysis pretreatment. The present work provides a potential approach, which is enzymatic hydrolysis pretreatment of chicken meat, to enhance the protein solubility and physicochemical quality of Cordyceps militaris chicken soup.

Protective effects of polysaccharides from Cordyceps gunnii mycelia against cyclophosphamide-induced immunosuppression to TLR4/TRAF6/NF-κB signalling in BALB/c mice

Polysaccharides are closely associated with immune regulation. In this study, the aim was to investigate the effect of polysaccharides from Cordyceps gunnii mycelia (PPS) in cyclophosphamide (CTX)-induced immunodeficient mice. Compared with the CTX-induced immunosuppressed mice, the spleen and thymus indexes in mice with orally administered PPS were significantly increased, body weight loss was alleviated, and the natural killer (NK) cytotoxicity and proliferative activities of the lymphocytes were elevated. The recovery of peripheral white blood cells, red blood cells, hemoglobins and platelets was accelerated. Furthermore, the results from ELISA showed that PPS could up-regulate the serum levels of IL-2, IL-12, IFN-γ and IgG, and reduce the level of TGF-β. Histopathological analysis of the spleen revealed the protective effect of PPS against CTX-induced immunosuppression. Western blotting results showed that PPS possessed immunomodulatory activity via TLR4/TRAF6/NF-κB signalling pathways. Finally, the intestinal absorption of PPS was poor, as detected in the Caco-2 transwell system. Taken together, these findings suggest that PPS plays a crucial role in protection against immunosuppression in cyclophosphamide-treated mice and could be a potential candidate for use in immune therapy regimens.

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.

Polysaccharides obtained from mycelia of Cordyceps militaris attenuated doxorubicin-induced cytotoxic effects in chemotherapy

Objectives

Fungus Cordyceps militaris has been used as a herbal tonic in traditional Chinese medicine, which could be surface liquid-cultured for mycelia production. To evaluate the potential of polysaccharides obtained from mycelia of Cordyceps militaris (PS-MCM) for attenuation of side-effects of chemotherapy.

Methods

Doxorubicin was used to induce cytotoxicity in THP-1 monocytes and EL-4 T cells, and the effects of PS-MCM on cell viability and cytokine production were detected on doxorubicin-treated THP-1 and EL-4 cells.

Results

PS-MCM reduced doxorubicin-induced cell death and promoted cell proliferation in THP-1 and EL-4 cells. Moreover, PS-MCM elevated the level of cytokines associated with immune-modulation of THP-1 and EL-4 cells.

Conclusion

These findings indicate that PS-MCM has potential for development as a functional food to counteract side effects of chemotherapy.