Isolation and identification of active components from Grifola frondosa and its anti-EV71 virus effect

BACKGROUND

It is reported that anti-enterovirus 71 (EV71) drugs have some side effects on human health. Notably, fungi plays a crucial role in promoting human health and anti-virus. Grifola frondosa is a type of large medicinal and edible fungi, rich in active substances. The present study aimed to investigate the anti-EV71 effect of G. frondosa and the potential active substances.

RESULTS

In the present study, the water extract of G. frondosa was subjected to ethanol precipitation to obtain the water-extracted supernatant of G. frondosa (GFWS) and water-extracted precipitation of G. frondosa. Their inhibitory effects on EV71 virus were studied based on a cell model. The results showed that GFWS had stronger security and anti-EV71 effects. In addition, the chemical constituents of GFWS were identified by ultra-high performance liquid chromatography-tandem mass spectrometry, which were selected for further separation and purification. Three compounds, N-butylaniline, succinic acid and l-tryptophan, were isolated from GFWS by NMR spectroscopy. It is noteworthy that N-butylaniline and l-tryptophan were isolated and identified from the G. frondosa fruiting bodies for the first time. Our study found that l-tryptophan has anti-EV71 virus activity, which reduced EV71-induced apoptosis and significantly inhibited the replication process after virus adsorption. Furthermore, it could also bind to capsid protein VP1 to prevent the virus from attaching to the cells.

CONCLUSION

l-tryptophan was an inhibitor of the EV71 virus, which could be used in infant nutrition and possibly provide a new drug to treat hand, foot and mouth disease. © 2024 Society of Chemical Industry.

Grifola frondosa polysaccharides: A review on structure/activity, biosynthesis and engineering strategies

Polysaccharides are the main polymers in edible fungi Grifola frondosa, playing a crucial role in the physiology and representing the healthy benefits for humans. Recent efforts have well elucidated the fine structures and biological functions of G. frondosa polysaccharides. The recently-rapid developments and increasing availability in fungal genomes also accelerated the better understanding of key genes and pathways involved in biosynthesis of G. frondosa polysaccharides. Herein, we provide a brief overview of G. frondosa polysaccharides and their activities, and comprehensively outline the complex process, genes and proteins corresponding to G. frondosa polysaccharide biosynthesis. The regulation strategies including strain improvement, process optimization and genetic engineering were also summarized for maximum production of G. frondosa polysaccharides. Some remaining unanswered questions in describing the fine synthesis machinery were also pointed out to open up new avenues for answering the structure-activity relationship and improving polysaccharide biosynthesis in G. frondosa. The review hopefully presents a reasonable full picture of activities, biosynthesis, and production regulation of polysaccharide in G. frondosa.

Structural characterization and immunomodulatory effect of a starch-like Grifola frondosa polysaccharides on cyclophosphamide-induced immunosuppression in mice

In this study, a pure Grifola frondosa polysaccharide (GFP-1) was extracted and purified from Grifola frondosa. By HPLC, GC-MS, FT-IR, and NMR analysis, GFP-1 was determined to be a starch-like polysaccharide with an average molecular weight of 3370 kDa. It included three monosaccharides, i.e., glucose, galactose, and mannose. The backbone of GFP-1 consisted of →4)-α-Glcp-(1→ and →4,6)-α-Glcp-(1 → . The side branches were composed of →6)-α-Galp-(1→, α-Glcp-(1→, and a small amount of α-Manp-(1 → . By using a cyclophosphamide (CTX)-induced immunosuppressed mice model, we evaluated the immunomodulatory activity of GFP-1. The results showed that GFP-1 increased the thymic and spleen indices, promoted the level of IgG and IgA in serum, and activated the mitogen-activated protein kinase (MAPK) pathway in CTX-induced mice. Also, GFP-1 significantly promoted the mRNA expression of intestinal barrier factors and protected intestinal structural integrity in immunosuppressed mice. In conclusion, the data presented here suggested that GFP-1 might be a potential immune-enhancing supplement.

Gastrointestinal metabolism characteristics and mechanism of a polysaccharide from Grifola frondosa

Grifola frondosa polysaccharide (GFP) is mainly composed of α-1,4 glycosidic bonds and possesses multiple pharmacological activities. However, the absence of pharmacokinetic studies has limited its further development and utilization. Herein, GFP was labeled with 5-DTAF (FGFP) and cyanine 5.5 amine (GFP-Cy5.5) to investigate its gastrointestinal metabolism characteristics and mechanism. Significant distributions of the polysaccharide in the liver and kidneys were observed by near infrared imaging. To investigate the specific distribution form of the polysaccharide, in vitro digestion models were constructed and revealed that FGFP was degraded in saliva and rat small intestine extract. The metabolites were detected in the stomach and small intestine, followed by further degradation in the distal intestine in the in vivo experiment. Subsequent investigations showed that α-amylase was involved in the gastrointestinal degradation of GFP, and its metabolite finally entered the kidneys, where it was excreted directly with urine.

Anti-α-glucosidase, Anti-proliferative and Anti-enterovirus 71 Activity of Secondary Metabolites Identified from Grifola Frondosa

Grifola frondosa, an edible and medicinal resource, is widely used as functional foods worldwide. To explore bioactive compounds against α-glucosidase, human tumor cells and enterovirus 71 (EV71), eight compounds were isolated from G. frondosa by chromatographic column. Among the isolated compounds, heptadecanoic acid, uridine and adenosine exhibited potent inhibition activity against α-glucosidase, ergosterols and ergosterol-5,8-peroxide showed anti-proliferative activity on tumor cells, while ergosterol and methyl linoleate displayed inhibition against the replication of EV71. Also, to our knowledge, this is the first study to report that fatty acids isolated from G. frondosa show potent inhibition against α-glucosidase and EV71. Further molecular docking results revealed that the active compounds in G. frondosa form hydrogen bonding, hydrophobic interactive and π-stacking with the active sites on the surface of α-glucosidase, CASP3 and VP1 proteins, thus promoting the active compounds to combine with the target protein to form a stable complex, thus playing an antagonistic role. Our results could provide a new active compound and mode of action for G. frondosa to treat diabetes, cancer and EV71-infected patients.

Purification and characterization of Se-enriched Grifola frondosa glycoprotein, and evaluating its amelioration effect on As3+ -induced immune toxicity

BACKGROUND

Selenium (Se)-enriched glycoproteins have been a research highlight for the role of both Se and glycoproteins in immunoregulation. Arsenic (As) is a toxicant that is potentially toxic to the immune function and consequently to human health. Several reports suggested that Se could reduce the toxicity of heavy metals. Moreover, more and more nutrients in food had been applied to relieve As-induced toxicity. Hence glycoproteins were isolated and purified from Se-enriched Grifola frondosa, and their preliminary characteristics as well as amelioration effect and mechanism on As³⁺ -induced immune toxicity were evaluated.

RESULTS

Four factions, namely Se-GPr11 (electrophoresis analysis exhibited one band: 14.32 kDa), Se-GPr22 (two bands: 20.57 and 31.12 kDa), Se-GPr33 (three bands: 15.08, 20.57 and 32.78 kDa) and Se-GPr44 (three bands: 16.73, 32.78 and 42.46 kDa), were obtained from Se-enriched G. frondosa via DEAE-52 and Sephacryl S-400 column. In addition, Se-GPr11 and Se-GPr44 are ideal proteins that contain high amounts of almost all essential amino acids. Thereafter, the RAW264.7 macrophage model was adopted to estimate the effect of Se-GPr11 and Se-GPr44 on As³⁺ -induced immune toxicity. The results showed that the pre-intervention method was the best consequent and the potential mechanisms were, first, by improving the oxidative stress state (enhancing the activity of superoxide dismutase and glutathione peroxidase, decreasing the levels of reactive oxygen species and malondialdehyde); secondly, through nuclear factor-κB and mitogen-activated protein kinase-mediated upregulation cytokines (interleukin-2 and interferon-γ) secretion induced by As³⁺ .

CONCLUSION

The results suggested Se-enriched G. frondosa may be a feasible supplement to improve health level of the As³⁺ pollution population. © 2021 Society of Chemical Industry.

Grifola frondosa may play an anti-obesity role by affecting intestinal microbiota to increase the production of short-chain fatty acids

BACKGROUND

Grifola frondosa (G. frondosa) is a fungus with good economic exploitation prospects of food and medicine homologation. This study aims to investigate the effects of G. frondosa powder suspension (GFPS) on the intestinal contents microbiota and the indexes related to oxidative stress and energy metabolism in mice, to provide new ideas for developing G. frondosa weight loss products.

METHODS

Twenty Kunming mice were randomly divided into control (CC), low-dose GFPS (CL), medium-dose GFPS (CM), and high-dose GFPS (CH) groups. The mice in CL, CM, and CH groups were intragastrically administered with 1.425 g/(kg·d), 2.85 g/(kg·d), and 5.735 g/(kg·d) GFPS, respectively. The mice in CC group were given the same dose of sterile water. After 8 weeks, liver and muscle related oxidative stress and energy metabolism indicators were detected, and the intestinal content microbiota of the mice was detected by 16S rRNA high-throughput sequencing.

RESULTS

After eight weeks of GFPS intervention, all mice lost weight. Compared with the CC group, lactate dehydrogenase (LDH) and malondialdehyde (MDA) contents in CL, CM, and CH groups were increased, while Succinate dehydrogenase (SDH) and Superoxide Dismutase (SOD) contents in the liver were decreased. The change trends of LDH and SDH in muscle were consistent with those in the liver. Among the above indexes, the change in CH is the most significant. The Chao1, ACE, Shannon, and Simpson index in CL, CM, and CH groups were increased. In the taxonomic composition, after the intervention with GFPS, the short-chain fatty acid (SCFA)-producing bacteria such as unclassified Muribaculaceae, Alloprevotella, and unclassified Lachnospiraceae increased. In linear discriminant analysis effect size (LEfSe) analysis, the characteristic bacteria in CC, CL, CM, and CH groups showed significant differences. In addition, some characteristic bacteria significantly correlated with related energy metabolism indicators.

CONCLUSION

The preventive effect of G. frondosa on obesity is related to changing the structure of intestinal content microbiota and promoting the growth of SCFAs. While excessive intake of G. frondosa may not be conducive to the antioxidant capacity and energy metabolism.

Antitumor activities of Grifola frondosa (Maitake) polysaccharide: A meta-analysis based on preclinical evidence and quality assessment

ETHNOPHARMACOLOGICAL RELEVANCE

The antitumor effects of Grifola frondosa/maitake polysaccharide (GFP) have been reported in many preclinical studies, especially in vivo experiments. The present meta-analysis aimed to provide an in vivo evidence and theoretical basis for future clinical trials by assessing the efficacy and underlying mechanisms of GFP in tumor treatment.

MATERIALS AND METHODS

English and Chinese databases were examined to include animal experiments to study the antitumor activity of GFP. Literature screening, data extraction, and meta-analysis were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In addition, the Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias (RoB) tool was used to assess the risk of bias of the included animal studies.

RESULTS

Potentially relevant studies (442) were identified, and finally 24 eligible studies (all in English) were included. The meta-analysis revealed that GFP has significant effects in inhibiting tumor growth (high dose: mean difference (MD) = -1.34, 95% confidence interval (CI) = [-1.73, -0.95]; low dose: MD = -5.68, 95% CI = [-7.27, -4.09]), improving tumor remission rate (odds ratio = 25.59, 95% CI = [9.08, 72.11]), and enhancing immune function in both cellular (CD4⁺ T cell percentage: MD = 3.03, 95% CI = [1.16, 4.90]; CD8⁺ T cell percentage: MD = 1.10, 95% CI = [-0.29, 2.49]) and humoral immunity (MD and [95% CI] of interleukin (IL)-2, IL-12 and tumor necrosis factor-α were 7.86 [6.29, 9.44], 35.95 [5.18, 66.72], and 10.03 [8.71, 11.36], respectively), and the differences between the two groups of the above indicators were statistically significant (all P < 0.01) except CD8⁺ T cell percentage. Additionally, the quality of the included studies was not high, and the risk of bias mainly concentrated on selection, detection, and reporting biases.

CONCLUSION

GFP is a potential candidate for tumor treatment and clinical trials.

TRIAL REGISTRATION

The review protocol for this study was registered with the PROSPERO database before beginning the review process (CRD42018108897).

The role of Rho1 gene in the cell wall integrity and polysaccharides biosynthesis of the edible mushroom Grifola frondosa

Grifola frondosa polysaccharides, especially β-glucans, showed the significant antitumor, hypoglycemic, and immune-stimulating activities. In the present study, a predominant regulatory subunit gfRho1p of β-1,3-glucan synthase in G. frondosa was identified with a molecular weight of 20.79 kDa and coded by a putative 648-bp small GTPase gene gfRho1. By constructing mutants of RNA interference and over-expression gfRho1, the roles of gfRho1 in the growth, cell wall integrity and polysaccharide biosynthesis were well investigated. The results revealed that defects of gfRho1 slowed mycelial growth rate by 22% to 33%, reduced mycelial polysaccharide and exo-polysaccharide yields by 4% to 7%, increased sensitivity to cell wall stress, and down-regulated gene transcriptions related to PKC-MAPK signaling pathway in cell wall integrity. Over-expression of gfRho1 improved mycelial growth rate and polysaccharide production of G. frondosa. Our study supports that gfRho1 is an essential regulator for polysaccharide biosynthesis, cell growth, cell wall integrity and stress response in G. frondosa.

Anti-diabetic effects of Grifola frondosa bioactive compound and its related molecular signaling pathways in palmitate-induced C2C12 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Grifola frondosa (GF), a high value medicinal mushroom, is popularly consumed as traditional medicines and health foods in China and Japan. It is a herbal medicine traditionally used for treating inflammation, cancer and diabetes.

AIM OF THE STUDY

This study aimed to examine the anti-diabetic effects of a GF bioactive compound ergosterol peroxide (EPO), and its mechanism(s) of action in palmitate (PA)-induced C2C12 cells.

MATERIALS AND METHODS

EPO was isolated and purified from GF fruiting bodies, and used to test for anti-diabetic activity in PA-induced murine C2C12 skeletal muscle cells through measuring glucose uptake, intracellular ROS production, and expressions of MAPKs, IRS-1, PI3K, Akt and GLUT-4 proteins.

RESULTS

EPO significantly up-regulated glucose absorption and increased cell growth. At 5 μM, EPO significantly enhanced glucose uptake and decreased ROS formation, as well as up-regulated the expression of IRS-1, p-IRS-1, PI3K, Akt, p-Akt, and GLUT-4 proteins in PA-induced cells, while their p-JNK and p-p38 expression were down-regulated. GLUT-4 siRNA treatment effectively down-regulated the EPO-induced absorption of glucose and inhibited the expression of GLUT-4.

CONCLUSION

These results suggest that the anti-diabetic effect of GF was from its bioactive compound EPO through the inhibition of ROS production, up-regulation of glucose absorption, and modulation of PI3K/Akt, MAPKs and GLUT-4 signaling transduction pathways.

Antitumor, Anti-Inflammatory and Antiallergic Effects of Agaricus blazei Mushroom Extract and the Related Medicinal Basidiomycetes Mushrooms, Hericium erinaceus and Grifola frondosa: A Review of Preclinical and Clinical Studies

Since the 1980s, medicinal effects have been documented in scientific studies with the related Basidiomycota mushrooms Agaricus blazei Murill (AbM), Hericium erinaceus (HE) and Grifola frondosa (GF) from Brazilian and Eastern traditional medicine. Special focus has been on their antitumor effects, but the mushrooms' anti-inflammatory and antiallergic properties have also been investigated. The antitumor mechanisms were either direct tumor attack, e.g., apoptosis and metastatic suppression, or indirect defense, e.g., inhibited tumor neovascularization and T helper cell (Th) 1 immune response. The anti-inflammatory mechanisms were a reduction in proinflammatory cytokines, oxidative stress and changed gut microbiota, and the antiallergic mechanism was amelioration of a skewed Th1/Th2 balance. Since a predominant Th2 milieu is also found in cancer, which quite often is caused by a local chronic inflammation, the three conditions-tumor, inflammation and allergy-seem to be linked. Further mechanisms for HE were increased nerve and beneficial gut microbiota growth, and oxidative stress regulation. The medicinal mushrooms AbM, HE and GF appear to be safe, and can, in fact, increase longevity in animal models, possibly due to reduced tumorigenesis and oxidation. This article reviews preclinical and clinical findings with these mushrooms and the mechanisms behind them.

A (1→6)-Branched (1→4)-β-d-Glucan from Grifola frondosa Inhibits Lipopolysaccharide-Induced Cytokine Production in RAW264.7 Macrophages by Binding to TLR2 Rather than Dectin-1 or CR3 Receptors

Mushroom polysaccharides including β-glucans possess various health-promoting properties and are known to be the major bioactive constituents of Grifola frondosa (GF), which is a popular edible and medicinal mushroom. Dectin-1, a pattern-recognition receptor, is responsible for recognizing β-glucans. In this study, parental RAW264.7 macrophages and Dectin-1-expressing RAW264.7 macrophages were used to investigate the anti-inflammatory activity and receptor involvement of the water-soluble polysaccharides from GF. Results indicated that the high molecular weight fraction of GF (GF70-F1; 1260 kDa) inhibited TNF-α and IL-6 production as well as NF-κB activation in lipopolysaccharide-induced macrophages. Chemical and enzymatic linkage analyses indicated that GF70-F1 mainly contained the known (1→3),(1→6)-β-d-glucan and a polysaccharide not previously isolated from GF, a nondigestible glucan with a β-(1→4)-linked backbone and β-(1→6)-linked branches. The ability of GF70-F1 to inhibit cytokine production was not affected by the expression level of Dectin-1 in cells, and a similar inhibitory activity was observed after removing the (1→3),(1→6)-β-d-glucan from GF70-F1. Blockade of Toll-like receptor 2 (TLR2) but not Dectin-1 or complement receptor 3 (CR3) attenuated the inhibitory activity of GF70-F1. The nondigestible (1→6)-branched (1→4)-β-d-glucan in GF70-F1 may contribute to the anti-inflammatory activity via interacting with TLR2 rather than Dectin-1 or CR3 receptors.

Peptidyl-Lys metalloendopeptidase (Lys-N) purified from dry fruit of Grifola frondosa demonstrates "mirror"digestion property with lysyl endopeptidase (Lys-C)

RATIONALE

Lys-N, also known as lysine-specific metalloendopeptidase, functions as the "sister" enzyme of lysyl endopeptidase (Lys-C) in proteomic research. Its digestion specificity at the N-terminal lysine residue makes it a very useful tool in proteomics analysis, especially in mass spectrometry (MS)-based de novo sequencing of proteins.

METHODS

Here we present a complete production process of highly purified Lys-N from dry fruit of Grifola frondosa (maitake mushroom). The purification process includes one step of microfiltration plus one step of UF/DF (ultrafiltration used in tandem with a diafiltration method) recovery and four steps of chromatographic purification.

RESULTS

The overall yield of the process was approximately 6.7 mg Lys-N protein/kg dry fruit of G. frondosa. The assay data demonstrated that the purified Lys-N exhibited high enzymatic activity and specificity.

CONCLUSIONS

The novel production process provides for the first time the extraction of Lys-N from dry fruit of G. frondosa. The process is also stable and scalable, and provides an economic way of producing the enzyme in large quantities for MS-based proteomics and other biological studies.

A β-glucan from Grifola frondosa effectively delivers therapeutic oligonucleotide into cells via dectin-1 receptor and attenuates TNFα gene expression

Grifola frondosa is an edible and medicinal mushroom with great nutritional values and bioactivities. In the present study, a soluble homogeneous β-glucan, GFPS, with high molecular mass of 5.42 × 10⁶ Da was purified from the fruit bodies of Grifola frondosa using 5% cold NaOH. The structure of GFPS was determined with FT-IR, NMR, and monosaccharide composition analysis, and was identified to be a β-D-(1-3)-linked glucan backbone with a single β-D-(1-6)-linked glucopyranosyl residue branched at C-6 on every third residue. Our results indicated that GFPS had a triple helical structure and could form complex with polydeoxyadenylic acid (poly[A]). Further studies demonstrated that GFPS could interact with poly[A] moiety of a designed antisense oligonucleotide (ASO) targeting the primary transcript of proinflammatory cytokine TNFα (TNFα-A60). This GFPS-based complex could incorporate TNFα-A60 into the macrophage cells via dectin-1 receptor and attenuate lipopolysaccharide-induced secretion of TNFα. Our results suggested that GFPS could be applied to deliver therapeutic oligonucleotides for the treatment of diseases such as inflammation and cancers.

Synergistic immuno-modulatory activity in human macrophages of a medicinal mushroom formulation consisting of Reishi, Shiitake and Maitake

A key characteristic of mushroom polysaccharides that elicit an immunomodulatory response is that they are rich in β-glucans and low in α-glucans. In this study we analysed nine commercially available preparations from three mushroom species, Reishi (Ganoderma lucidum), Shiitake (Lentinula edodes) and Maitake (Grifola frondosa), for β- and α-glucan content. Based on β- and α-glucan content we selected three extracts to combine into a formula and evaluated the ability of the individual extracts and formula to impact on the expression of cytokines IL-1α, IL-6, IL-10 and TNF-α in human macrophages with and without LPS stimulation. The majority of mushroom extracts and the formula were found to be highly potent immuno-stimulators possessing EC50 values lower than 100 μg/mL. Interestingly the mushroom formula had lower EC50 values in TNF-α expression from LPS stimulated macrophages compared to the individual extracts, suggesting a potential synergistic effect of the mushroom formula. A response additivity graph and curve-shift analysis illustrated that indeed the mushroom formula exhibited an immuno-stimulatory synergistic effect on the expression of the majority of cytokines evaluated in both LPS stimulated and non-stimulated human macrophages, with IL-10 having an antagonistic response. This study represents the first report of a synergistic immuno-modulatory response in human macrophages elicited from a mushroom formula rationally derived from β- and α-glucan content.

Anti-inflammatory and Proapoptotic Properties of the Natural Compound o-Orsellinaldehyde

Metabolic syndrome is a cluster of medical conditions that increases the risk of developing cardiovascular disease and type 2 diabetes. Numerous studies have shown that inflammation is directly involved in the onset of metabolic syndrome and related pathologies. In this study, in silico techniques were applied to a natural products database containing molecules isolated from mushrooms from the Catalan forests to predict molecules that can act as human nuclear-factor κβ kinase 2 (IKK-2) inhibitors. IKK-2 is the main component responsible for activating the nuclear-factor κβ transcription factor (NF-κβ). One of these predicted molecules was o-orsellinaldehyde, a molecule present in the mushroom Grifola frondosa. This study shows that o-orsellinaldehyde presents anti-inflammatory and pro-apoptotic properties by acting as IKK-2 inhibitor. Additionally, we suggest that the anti-inflammatory and pro-apoptotic properties of Grifola frondosa mushroom could partially be explained by the presence of o-orsellinaldehyde on its composition.

Se-enriched G. frondosa polysaccharide protects against immunosuppression in cyclophosphamide-induced mice via MAPKs signal transduction pathway

To assess the immunomodulatory and antioxidant activities of a Se-polysaccharide from Se-enriched G. frondosa (Se-GFP-22), immunosuppressed mice models were generated by cyclophosphamide (CTX) administration and then treated with Se-GFP-22. Results showed that Se-GFP-22 could increase thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes, DTH reaction, serum hemolysin formation and immunoglobulin (Ig G, Ig A and Ig M) levels in CTX-treated mice. Se-GFP-22 significantly enhanced the antioxidant activity in CTX-treated mice, as shown by the evaluation of GSH-Px, SOD and CAT activities, as well as MDA levels in serum, liver and kidney. Se-GFP-22 strongly stimulated inflammatory cytokines (IL-2 and IFN-γ) and NO productions by up-regulating mRNA expressions of IL-2, IFN-γ and iNOS. Se-GFP-22 possessed the immunomodulatory activity by up-regulating various transcription factors (JNK, ERK, and p38) in MAPKs signaling pathways. This study suggested that Se-GFP-22 may provide an alternative strategy in lessening chemotherapy-induced immunosuppression.

Grifola frondosa polysaccharide: a review of antitumor and other biological activity studies in China

Grifola frondosa, a species of Basidiomycotina, is an edible medicinal mushroom with a large fruiting body characterized by overlapping caps. The β-glucan is the major biologically active component in G. frondosa polysaccharide (GFP) or D-fraction, which has been studied extensively for nearly 30 years. GFP was approved as an adjunctive therapeutic drug in China for treating cancers in 2010. In this article, based on the search results of Chinese VIP, CNKI, and Wanfang databases, 105 independent animal studies were summarized. The chemical structure, the antitumor, immunomodulatory, anti-diabetic, anti-hyperlipidemia, and antiviral activities and molecular mechanisms of GFP are reviewed and discussed.

Griflola frondosa (GF) produces significant antidepressant effects involving AMPA receptor activation in mice

CONTEXT

Griflola frondosa (Fr) S.F. Gray (Meripilaceae) (GF) is a medical mushroom, and its regulation of the immune system is of interest for the treatment of mood disorders. α-Amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors are the central mediator for the treatment of depression.

OBJECTIVE

This study examines the antidepressant effects of GF and the role of AMPA in these antidepressant effects.

MATERIALS AND METHODS

The CD-1 mice were fed with GF- or Pleurotus ostreatus [(Jacq.: Fr) Kumm (Pleurotaceae)] (PO)-containing food for 1 day or 5 days. The antidepressant effects was determined in the tail suspension test (TST), forced swim test (FST), and open field test (OFT). The involvement of AMPA receptors was determined by the application of the AMPA-specific blocker GYKI 52466.

RESULTS

Treatments with 20%, 33% or 50% of GF-containing food significantly decreased the immobility time (63.6, 56.9, and 52.0% in TST; and 50.8, 43.2, and 38.2% in FST) after 1 day and (62.3, 51.8, and 52.8% in TST; and 49.5, 45.1, and 40.3% in FST) after 5 days. GF-containing food did not cause hyperactive effects in the OFT. The antidepressant effects of the 33% of GF-containing food (down-to 51.3% in 1-day TST and 46.8% in 5-day FST) were significantly stronger than that of the 33% of PO-containing food (down-to 85.5% in 1-day TST and 82.0% in 5-day FST). AMPA-specific blocker GYKI 52466 was able to block the antidepressant effects of the GF-containing food.

CONCLUSION

GF demonstrated the potential as a safe medical food supplement for the patient with depression.

Antitumor activity of orally administered maitake α-glucan by stimulating antitumor immune response in murine tumor

Maitake α-glucan, YM-2A, isolated from Grifola frondosa, has been characterized as a highly α-1,6-branched α-1,4 glucan. YM-2A has been shown to possess an anti-virus effect in mice; however, it does not directly inhibit growth of the virus in vitro, indicating that the anti-virus effect of YM-2A might be associated with modulation of the host immune system. In this study, we found that oral administration of YM-2A could inhibit tumor growth and improve survival rate in two distinct mouse models of colon-26 carcinoma and B16 melanoma. Orally administered YM-2A enhanced antitumor immune response by increasing INF-γ-expressing CD4⁺ and CD8⁺ cells in the spleen and INF-γ-expressing CD8⁺ cells in tumor-draining lymph nodes. In vitro study showed that YM-2A directly activated splenic CD11b⁺ myeloid cells, peritoneal macrophages and bone marrow-derived dendritic cells, but did not affect splenic CD11b^- lymphocytes or colon-26 tumor cells. YM-2A is more slowly digested by pancreatic α-amylase than are amylopectin and rabbit liver glycogen, and orally administered YM-2A enhanced the expression of MHC class II and CD86 on dendritic cells and the expression of MHC class II on macrophages in Peyer’s patches. Furthermore, in vitro stimulation of YM-2A increased the expression of pro-inflammatory cytokines in Peyer’s patch CD11c⁺ cells. These results suggest that orally administered YM-2A can activate dendritic cells and macrophages in Peyer’s patches, inducing systemic antitumor T-cell response. Thus, YM-2A might be a candidate for an oral therapeutic agent in cancer immunotherapy.

[Experimental study on intervention effect of Grifola frondosa on nonalcoholic steatohepatitis]

To study the preventive effect of Grifola frondosa on nonalcoholic steatohepatitis (NASH). The rat model of NASH was established by feeding high-fat diets for 12 weeks and intervened with 0.5 g · kg(-1) · d(-1) and 1.0 g · kg(-1) · d(-1) of C. frondosa powder suspensions. The degrees of hepatocyte fatty degeneration and inflammation were observed under the optical microscope with routine HE staining. The NAFLD activity scores (NAS) were calculated. Serum ALT, AST and hepatic TG and CHOL were tested by the biochemical method. The hepatic MDA was examined by thiobarbituric acid method. The hepatic SOD was tested by the xanthine oxidase test. The hepatic GSH-PX activity was determined by the dithio-nitrobenzoic acid method. Hepatic TNF-α and IL-6 were detected by the enzyme-linked immunosorbent assay (ELISA). The NASH model group induced by high-fat diets showed higher hepatic NAS, ser- um ALT, AST, CHOL and hepatic TG, CHOL, MDA, TNF-α, IL-6 (P < 0.01 or P < 0.05) and lower serum TG and hepatic SOD, GSH-PX (P < 0.01, P < 0.05) than the normal control group. After being intervened with different doses of G. frondosa, the NASH group revealed significantly lower hepatic NAS, serum ALT and hepatic TG, CHOL, MDA, TNF-α and IL-6 (P < 0.05) and higher hepatic SOD, GSH-PX (P < 0.05) than the model group. G. frondosa may prevent the further development of NASH by improving the disorder of lipid metabolism in rats with NASH induced by high-fat diets, relieving the level of oxidative stress and reducing the generation of inflammatory cytokines.

Maitake mushroom extract in myelodysplastic syndromes (MDS): a phase II study

Background

Myelodysplastic syndromes (MDS) are characterized by ineffective erythropoiesis with dysplastic bone marrow leading to peripheral cytopenia, risk of infection, and progression to acute myelogenous leukemia. Maitake mushroom beta-glucan, a dietary supplement, stimulates hematopoietic progenitor cell differentiation, granulocyte colony-stimulating factor production, and recovery of peripheral blood leukocytes after bone marrow injury. This phase II trial examined the effects of Maitake on innate immune function in MDS.

Methods

Myelodysplastic syndromes patients with International Prognostic Scoring System Low- and Intermediate-1-risk disease received oral Maitake extract at 3 mg/kg twice daily for 12 weeks. Primary endpoints included neutrophil count and function tested as endogenous or stimulated neutrophil production of reactive oxygen species (ROS) by flow cytometry compared with age-matched healthy controls (HC). ROS activators were Escherichiacoli, phorbol ester, and the bacterial peptide N-formylmethionyl-leucyl-phenylalanine (fMLP). Complete blood counts, chemistry panels, iron studies, and monocyte function were evaluated.

Results

Of 21 patients enrolled, 18 completed the study and were evaluable. Maitake increased endogenous (basal) neutrophil (p = 0.005) and monocyte function (p = 0.021). Pre-treatment monocyte response to E. coli was reduced in MDS patients compared with HC (p = 0.002) and increased (p = 0.0004) after treatment. fMLP-stimulated ROS production response also increased (p = 0.03). Asymptomatic eosinophilia occurred in 4 patients (p = 0.014). Other changes in albumin, hemoglobin, and total protein were not clinically relevant.

Conclusions

Maitake was well tolerated. Enhanced in vitro neutrophil and monocyte function following treatment demonstrate that Maitake has beneficial immunomodulatory potential in MDS. Further study is warranted.

The functional role of Cys3-Cys4 loop in hydrophobin HGFI

Hydrophobins are a large group of low-molecular weight proteins. These proteins are highly surface-active and can form amphipathic membranes by self-assembling at hydrophobic-hydrophilic interfaces. Based on physical properties and hydropathy profiles, hydrophobins are divided into two classes. Upon the analysis of amino acid sequences and higher structures, some models suggest that the Cys3-Cys4 loop regions in class I and II hydrophobins can exhibit remarkable difference in their alignment and conformation, and have a critical role in the rodlets structure formation. To examine the requirement for the Cys3-Cys4 loop in class I hydrophobins, we used protein fusion technology to obtain a mutant protein HGFI-AR by replacing the amino acids between Cys3 and Cys4 of the class I hydrophobin HGFI from Grifola frondosa with those ones between Cys3 and Cys4 of the class II hydrophobin HFBI from Trichoderma reesei. The gene of the mutant protein HGFI-AR was successfully expressed in Pichia pastoris. Water contact angle (WCA) and X-ray photoelectron spectroscopy (XPS) measurements demonstrated that the purified HGFI-AR could form amphipathic membranes by self-assembling at mica and hydrophobic polystyrene surfaces. This property enabled them to alter the surface wettabilities of polystyrene and mica and change the elemental composition of siliconized glass. In comparison to recombinant class I hydrophobin HGFI (rHGFI), the membranes formed on hydrophobic surfaces by HGFI-AR were not robust enough to resist 1 % hot SDS washing. Atomic force microscopy (AFM) measurements indicated that unlike rHGFI, no rodlet structure was observed on the mutant protein HGFI-AR coated mica surface. In addition, when compared to rHGFI, no secondary structural change was detected by Circular Dichroism (CD) spectroscopy after HGFI-AR self-assembled at the water-air interface. HGFI-AR could not either be deemed responsible for the fluorescence intensity increase of Thioflavin T (THT) and the Congo Red (CR) absorption spectra shift (after the THT(CR)/HGFI-AR mixed aqueous solution was drastically vortexed). Remarkably, replacement of the Cys3-Cys4 loop could impair the rodlet formation of the class I hydrophobin HGFI. So, it could be speculated that the Cys3-Cys4 loop plays an important role in conformation and functionality, when the class I hydrophobin HGFI self-assembles at hydrophobic-hydrophilic interfaces.

[Antiviral properties of basidiomycetes metabolites]

The data on the antiviral action of the Ganoderma lucidum, Lentinus edodes, Grifola frondosa, Agaricus brasiliensis and other basidiomycetes metabolites are summurized. The metabolites of these species of basidiomycetes exhibit a direct antiviral effect on herpes simplex virus types I and II, human immunodeficiency virus (HIV), hepatitis B virus, vesicular stomatitis virus, influenza virus, Epstein-Barr virus, and others. Moreover, metabolites of basidiomycetes increased antiviral immunity.

Inducement of cytokine release by GFPBW2, a novel polysaccharide from fruit bodies of Grifola frondosa , through dectin-1 in macrophages

Polysaccharides, especially β-glucans isolated from various species of mushrooms, are considered as biological response modifiers (BRMs) to be widely used in the treatment of cancer, especially due to their immunostimulatory activity. We herein characterized the structure of a novel water-soluble homogeneous polysaccharide (GFPBW2) from the fruit bodies of mushroom Grifola frondosa and investigated its immunomodulatory activity in vitro. GFPBW2 was purified from the alkali-extracted fractions by stepwise elution with a molecular weight of 26.2 kDa. On the basis of infrared and NMR spectroscopy, methylation and monosaccharide composition analysis, partial acid hydrolysis, and Smith degradation, its structure was elucidated to possess a backbone consisting of β-d-1,3- and β-d-1,4-linked glucopyranosyl residues, with branches attached to O-6 of β-d-1,3-linked glucopyranosyl residues. Functionally, it is an effective inducer of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) secretion in murine resident peritoneal macrophages. Using quartz crystal microbalance (QCM) analysis, we found that GFPBW2 could bind dendritic cell-associated C-type lectin-1 (Dectin-1) with an affinity constant (Kd) value of 1.08 × 10 (-7) M, while it could activate Syk and enhance TNF-α production in RAW264.7 cells overexpressing wild type but not mutant Dectin-1. Furthermore, Syk, NF-κB signaling, and cytokine release in resident peritoneal macrophages induced by GFPBW2 could be significantly inhibited by a specific Dectin-1 blocking reagent, Laminarin. These data suggested that GFPBW2 might be a potential ligand of Dectin-1, and the potential of GFPBW2 to activate macrophage through triggering cytokine secretion might be attributed, at least in part, to the involvement of Dectin-1.

Characterization of a novel maitake (Grifola frondosa) protein that activates natural killer and dendritic cells and enhances antitumor immunity in mice

Grifola frondosa, also known as maitake, is a culinary mushroom with immune-enhancing and antitumor effects. Numerous studies have investigated the activity of maitake polysaccharide extracts, but studies of maitake proteins are scarce. In this study, we purified and characterized a new G. frondosa protein, GFP, from maitake fruiting bodies. GFP is a nonglucan heterodimeric 83 kDa protein that consists of two 41 kDa subunits. GFP induced interferon-γ secretion by murine splenocytes and natural killer cells and activated the maturation of bone marrow-derived dendritic cells (BMDCs) via a TLR4-dependent mechanism. GFP-treated BMDCs promoted a Th1 response and exhibited significant antitumor activity when transferred into tumor-bearing mice. In conclusion, we are the first to reveal the critical role of GFP in modulating the immune response and to link the immune-enhancing effects of maitake to its antitumor activities.

Enhancement of in vitro and in vivo anticancer activities of polysaccharide peptide from Grifola frondosa by chemical modifications

CONTEXT

Grifola frondosa (Polyporaceae), maitake, is a widely consumed edible mushroom in some Asian countries. The fruit bodies and mycelia of maitake have shown different bioactive compounds with anticancer and other therapeutic properties.

OBJECTIVE

This study evaluated three chemically modified maitake polysaccharide-peptides' (MPSP) adjuvant effect (in vivo) and anticancer activity (in vitro growth inhibitory effect) compared with crude MPSP from G. frondosa.

MATERIALS AND METHODS

We investigated the possibility of enhancing the adjuvant effect and anticancer effect of crude MPSP by using simple chemical modification methods to convert crude MPSP to phosphorylated, acetylated or esterified MPSPs. The adjuvant effect and growth inhibitory effect were evaluated by C6 cell inoculated rat model with cyclophosphamide (CPA) treatment and in vitro cell viability assay, respectively.

RESULTS

All four tested MPSPs showed significant adjuvant effect to CPA treatment on rats inoculated with C6 cancer cells. In addition, an obvious growth inhibitory effect was observed in C6 cancer cells but not in normal brain cells treated with various forms of MPSPs. Only phosphorylation could significantly (p < 0.05) improve the adjuvant effect (in vivo) and growth inhibitory effect. A same rank order (phosphorylated MPSP > esterified MPSP ≥ acetylated MPSP ≥ crude MPSP) of efficacy was observed in both the in vivo and in vitro assays.

DISCUSSION AND CONCLUSION

This study showed chemical phosphorylation could markedly enhance both adjuvant effects and growth inhibitory effects. This study demonstrated the feasibility of enhancing the efficacy of MPSP by using a simple chemical modification method, and this provides a foundation for future study in this area.

A polysaccharide extracted from Grifola frondosa enhances the anti-tumor activity of bone marrow-derived dendritic cell-based immunotherapy against murine colon cancer

We previously isolated the novel heteropolysaccharide maitake Z-fraction (MZF) from the maitake mushroom (Grifola frondosa), and demonstrated that MZF significantly inhibited tumor growth by inducing cell-mediated immunity. In this study, we demonstrated that MZF upregulated the expression of CD80, CD86, CD83, and MHC II on bone marrow-derived dendritic cells (DCs) and significantly increased interleukin-12 (IL-12) and tumor necrosis factor-alpha production by DCs in a dose-dependent manner. MZF-treated DCs significantly stimulated both allogeneic and antigen-specific syngenic T cell responses and enhanced antigen-specific interferon-gamma (IFN-gamma) production by syngenic CD4(+) T cells; however, MZF-treated DCs did not affect IL-4 production. Furthermore, the enhancement of IFN-gamma production in CD4(+) T cells, which was induced by MZF-treated DCs, was completely inhibited by the addition of an anti-IL-12 antibody. These results indicate that MZF induced DC maturation and antigen-specific Th1 response by enhancing DC-produced IL-12. We also demonstrated that DCs pulsed with colon-26 tumor lysate in the presence of MZF induced both therapeutic and preventive effects on colon-26 tumor development in BALB/c mice. These results suggest that MZF could be a potential effective adjuvant to enhance immunotherapy using DC-based vaccination.

Prokaryotic expression, purification, and polyclonal antibody production of a hydrophobin from Grifola frondosa

Hydrophobins are small fungal proteins that self-assemble spontaneously at hydrophilic-hydrophobic interfaces and change the polar nature of the surfaces to which they attach. A new hydrophobin gene hgfI was identified recently from the edible mushroom Grifola frondosa. In this paper, the cloning, expression, purification, and polyclonal antibody preparation of the HGFI were described. The hgfI gene was cloned into pET-28a expression plasmid at the EcoRI and NdeI restriction sites and then transformed into Escherichia coli BL21 strain. SDSPAGE analysis showed that recombinant HGFI protein was satisfactorily expressed by optimizing the concentration and induction time of IPTG. The expressed recombinant HGFI protein was purified by electroelution because its inclusion body was insoluble in traditional processing method. After a desalting procedure with Sephadex G-25, the recombinant HGFI protein was used to immunize adult rabbits following standard protocol. ELISA and western blot analysis indicated that the produced antiserum could detect both HGFI protein expressed in the prokaryotic (E. coli) and in the eukaryotic cells (G. frondosa). Furthermore, the antiserum was used to determine the localization of HGFI protein in G. frondosa cells using an immunofluorescence technique. The results demonstrated that HGFI protein was localized in the cell wall, especially at the budding position of hypha. The polyclonal antibody against HGFI will facilitate further production and functional study of HGFI protein.

Anti-diabetic effect of an α-glucan from fruit body of maitake (Grifola frondosa) on KK-Ay mice

We have evaluated the anti-diabetic effect of a α-glucan (MT-α-glucan) from the fruit body of maitake mushrooms (Grifola frondosa) on KK-Ay mice (a kind of genetical type 2 diabetes animal model). The effects of MT-α-glucan (450 or 150 mg kg−1) on diabetic mice were investigated by observing the changes in body weight, the level of fasting plasma glucose, glycosylated serum protein (GSP), hepatic glycogen, serum insulin, triglycerides, cholesterol, free fatty acid, liver superoxide dismutase (SOD), glutathione peroxidase (GSHpx), reduced glutathione (GSH) and malondialdehyde (MDA). Moreover, the binding capacity of insulin receptors on liver crude plasma membranes was assayed and histopathological changes in the pancreas were observed. Treatment with MT-α-glucan significantly decreased the body weight, level of fasting plasma glucose, GSP, serum insulin, triglycerides, cholesterol, free fatty acid and MDA content in livers. Treatment with MT-α-glucan significantly increased the content of hepatic glycogen, GSH and the activity of SOD and GSHpx. Moreover, the insulin binding capacity to liver crude plasma membranes increased and histopatho-logical changes in the pancreas were ameliorated in the treatment group. These data suggest that MT-α-glucan has an anti-diabetic effect on KK-Ay mice, which might be related to its effect on insulin receptors (i.e., increasing insulin sensitivity and ameliorating insulin resistance of peripheral target tissues).

[Higher fungi in traditional and modern medicine]

The medicinal use of mushrooms, so-called higher fungi, has a very long tradition in the Asian countries, whereas their use in the Western hemisphere has been slightly increasing only since the last decades. The paper gives an overview about the most important medicinal mushrooms and summarizes the actual knowledge about chemistry and pharmacology of Lentinula edo-des (Shiitake, Golden Oak Mushroom), Ganoderma lucidum (Reishi, Ling Zhi), Agaricus brasiliensis (Royal sun agaricus), Grifola frondosa (Maitake, Hen-of-the-Woods) and Hericium erinaceus (Yamabushitake, Lion's Man, Monkey's Head).

Activity and toxicity of Cr(III)-enriched Grifola frondosa in insulin-resistant mice

This study was designed to evaluate the effect of administration of chromium-enriched Grifola frondosa (CEGF) in insulin-resistant sucrose-fed mice. Mice were randomly assigned to be unsupplemented (S group) or to receive oral CEGF at a dose of 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 mg/kg per day chromium. A control group (C) did not consume sucrose and was not supplemented. Sucrose-fed mice had an elevated serum insulin concentration compared with controls and this was significantly lower in sucrose-fed mice that received CEGF (4.0 and 5.0 mg/kg per day chromium), which did not differ from controls. Impaired glucose tolerance in sucrose-fed mice, evidenced by the poor glucose disposal rate following an intraperitoneal glucose tolerance test, was significantly improved in mice receiving CEGF. CEGF is essentially nontoxic at the dose of 4.0 and 5.0 mg/kg per day. These results indicate that CEGF may have potential beneficial effects in insulin-resistant prediabetic conditions.

Characterization and antitumor effect of a novel polysaccharide from Grifola frondosa

A novel polysaccharide, MZF, with a molecular mass of 23 kDa was isolated from Grifola frondosa . Results from methylation and (1)H NMR led to the conclusion that MZF is a heteropolysaccharide consisting of -->6)-alpha-D-Galp-(1--> (36.2%), -->3)-alpha-L-Fucp-(1--> (14.5%), -->6)-alpha-D-Manp-(1--> (9.4%), -->3)-beta-D-Glcp-(1--> (10.1%), alpha-D-Manp-(1--> (23.2%), and -->3,6)-beta-D-Glcp-(1--> (6.5%). Although MZF did not affect the proliferation of colon-26 cells in vitro, it significantly inhibited tumor growth in BALB/cA mice inoculated with colon-26 cancer cells. Moreover, MZF significantly induced the proliferation of splenocytes and peritoneal macrophages. The mRNA expression of IL-12p40, IL-2 and IFN-gamma were increased significantly in MZF-treated spleen. Furthermore, MZF augmented the percentage of IFN-gamma-producing cells in both splenic CD4(+) and CD8(+) T cells and tumor infiltrating CD4(+) and CD8(+) T cells and enhanced the cytotoxic activity of NK cells and CTLs. These results indicate that MZF is a novel effective immunomodulator that has antitumor activity associated with induced cell-mediated immunity.

Hypoglycemic activity of Grifola frondosa rich in vanadium

The hypoglycemic activity of fermented mushroom of Grifola frondosa rich in vanadium (GFRV) was studied in this paper. Alloxan- and adrenalin-induced hyperglycemic mice were used in the study. The blood glucose and the HbA1c of the mice were analyzed respectively. After the mice were administered (ig) with GFRV, the blood glucose and the HbA1c of alloxan-induced hyperglycemic mice decreased (p < 0.05, p < 0.01) and ascension of blood glucose induced by adrenalin was inhibited (p < 0.01). Also, the bodyweight of the alloxan-induced hyperglycemic mice was increased gradually. In the fermented mushroom of G. frondosa, vanadium at lower doses in combination with G. frondosa induced significant decreases of the blood glucose and HbA1c levels in hyperglycemic mice.

A comparison of hypoglycemic activity of three species of basidiomycetes rich in vanadium

The hypoglycemic activity of fermented mushroom of three fungi of basidiomycetes rich in vanadium was studied in this paper. Alloxan- and adrenalin-induced hyperglycemic mice were used in the study. The blood glucose and the sugar tolerance were determined. After the mice were administered (ig) with Coprinus comatus rich in vanadium, the blood glucose of alloxan-induced hyperglycemic mice decreased (p < 0.05), ascension of blood glucose induced by adrenalin was inhibited (p < 0.01) and the sugar tolerance of the normal mice was improved. However, the same result did not occur in Ganoderma lucidum and Grifola frondosa group. Compared with Ganoderma rich in vanadium and Grifola frondosa rich in vanadium, the hypoglycemic effects of Coprinus comatus rich in vanadium on hyperglycemic animals are significant; it may be used as a hypoglycemic food or medicine for hyperglycemic people.

Maitake beta-glucan enhances umbilical cord blood stem cell transplantation in the NOD/SCID mouse

Beta glucans are cell wall constituents of yeast, fungi and bacteria, as well as mushrooms and barley. Glucans are not expressed on mammalian cells and are recognized as pathogen-associated molecular patterns (PAMPS) by pattern recognition receptors (PRR). Beta glucans have potential activity as biological response modifiers for hematopoiesis and enhancement of bone marrow recovery after injury. We have reported that Maitake beta glucan (MBG) enhanced mouse bone marrow (BMC) and human umbilical cord blood (CB) cell granulocyte-monocyte colony forming unit (GM-CFU) activity in vitro and protected GM-CFU forming stem cells from doxorubicin (DOX) toxicity. The objective of this study was to determine the effects of MBG on expansion of phenotypically distinct subpopulations of progenitor and stem cells in CB from full-term infants cultured ex vivo and on homing and engraftment in vivo in the nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse. MBG promoted a greater expansion of CD34+CD33+CD38- human committed hematopoietic progenitor (HPC) cells compared to the conventional stem cell culture medium (P = 0.002 by ANOVA). CD34+CXCR4+CD38- early, uncommitted human hematopoietic stem cell (HSC) numbers showed a trend towards increase in response to MBG. The fate of CD34+ enriched CB cells after injection into the sublethally irradiated NOS/SCID mouse was evaluated after retrieval of xenografted human CB from marrow and spleen by flow cytometric analysis. Oral administration of MBG to recipient NOS/SCID mice led to enhanced homing at 3 days and engraftment at 6 days in mouse bone marrow (P = 0.002 and P = 0.0005, respectively) compared to control mice. More CD34+ human CB cells were also retrieved from mouse spleen in MBG treated mice at 6 days after transplantation. The studies suggest that MBG promotes hematopoiesis through effects on CD34+ progenitor cell expansion ex vivo and when given to the transplant recipient could enhance CD34+ precursor cell homing and support engraftment.

Maitake mushroom (Grifola frondosa): systematic review by the natural standard research collaboration

The objective of this study was to evaluate the scientific evidence on maitake, including expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing. This review serves as a clinical support tool. Electronic searches were conducted in 10 databases, 20 additional journals (not indexed in common databases), and bibliographies from 50 selected secondary references. No restrictions were placed on the language or quality of the publications. All literature collected pertained to efficacy in humans, dosing, precautions, adverse effects, use in pregnancy and lactation, interactions, alteration of laboratory assays, and mechanisms of action. Standardized inclusion and exclusion criteria were used for selection. Grades were assigned using an evidence-based grading rationale. There was a lack of systematic study on the safety and effectiveness of maitake in humans. However, based on popular use and supportive scientific data, three indications are discussed in this review: cancer, diabetes, and immunostimulation. Despite the lack of scientific evidence, maitake mushroom remains a popular agent in commercial products. Future randomized controlled trials are warranted.

Isolation, identification and function of a novel anti-HSV-1 protein from Grifola frondosa

A novel antiviral protein was purified from an extract of Grifola frondosa fruiting bodies using a procedure that included 40% ammonium sulfate precipitation and DEAE-cellulose ion exchange chromatography, and designated GFAHP. This protein inhibited herpes simplex virus type 1 (HSV-1) replication in vitro with an IC(50) value of 4.1 microg/ml and a therapeutic index >29.3. Higher concentrations of GFAHP (125 and 500 microg/ml) also significantly reduced the severity of HSV-1 induced blepharitis, neovascularization, and stromal keratitis in a murine model. Topical administration of GFAHP to the mouse cornea resulted in a significant decrease in virus production (mean virus yields: 3.4log10PFU in the treated group and 4.19log10PFU in the control group). We proved that GFAHP directly inactivates HSV-1 while simultaneously inhibiting HSV-1 penetration into Vero cells. Gel electrophoresis showed that GFAHP had a molecular weight of 29.5 kDa. GFAHP was tryptic digested and analyzed from the PMF of matrix assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and nanoelectrospray ionization tandem mass spectrometry. The N-terminal sequence of GFAHP consisted of an 11 amino acid peptide, NH(2)-REQDNAPCGLN-COOH that did not match any known amino acid sequences, indicating that GFAHP is likely to be a novel antivirus protein. To our knowledge, this is the first report that characterizes an anti-HSV protein from G. frondosa.

Chemical characteristics and immuno-modulating activities of exo-biopolymers produced by Grifola frondosa during submerged fermentation process

The immuno-modulating activities and chemical characteristics of exo-biopolymer (EX-GF) produced by a submerged mycelial culture of Grifola frondosa were studied. The EX-GF was fractionated into EX-GF-Fr.I, II, and III by Sephadex G-100 gel chromatography. Anti-complementary activity of EX-GF-Fr.III was highest (71.1%) among them, and its activation system occurred through both classical and alternative pathways, where the classical pathway found to be major one. Lysosomal enzyme activity and nitric oxide production ability of macrophage were also found to be mediated by EX-GF-Fr.III. The molecular weight of the EX-GF-Fr.I, II, and III was estimated to be about 163, 40, and 2.8 kDa, respectively. Total sugar and protein contents of the three fractions were 80.3, 61.9 and 89.3%, and 17.3, 35.2, and 10.7%, respectively. The sugar and amino acid compositions of the EX-GF-Fr.I, II, and III were also analyzed in detail.

[Isolation and characterization of lectin from the surface of Grifola frondosa (FR.) S.F. Gray mycelium]

For the first time, from the surface of the dikaryotic mycelium of the xylotrophic basidiomycete Grifola frondosa 0917 a lectin has been isolated with a molecular mass of 68 +/- 1 kDa, consisting of two subunits of 33-34 kDa each. The lectin is a hydrophilic glycoprotein with the protein : glycan ratio of 3 : 1. It exhibits high affinity to native rabbit erythrocytes and to human erythrocytes of the 0 blood group, but not to trypsin-treated ones. The hemagglutination (HA) caused by lectin was not blocked by any of the 25 tested mono-, di-, and amino sugars; it was also not blocked by some of glyco derivatives. Only 13.9 microg/ml of the homogeneous preparation of a polysaccharide, a linear D-rhamnan with the structure of the repetitive component --> 2)-beta-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> blocked hemagglutination completely. The analysis of the amino acid composition of the lectin showed the greatest percentage of amino acids with positively charged R groups, arginine, lysine, and histidine, as well as the complete absence of sulfur-containing amino acids, cysteine, and methionine. D-glucose and D-glucosamine were detected in the carbohydrate part.

[Behaviors of beta-glucan from Grifola frondosa in high performance gel permeation chromatography]

The high performance gel permeation chromatographic (HPGPC) behaviors of four beta-1, 3/1, 6-glucans (GF1, GF2, GF3, GF4) with different protein contents and one alpha-1, 4/1, 6-glucan (P100) from Grifola frondosa were examined with different concentrations of NaCl solution and pH values. The experimental results showed that the relative molecular mass (M(r)) of the beta-glucans sharply dropped as the NaCl concentration was less than 0.025 mol/L and then tended to be stable as the NaCl concentration was raised from 0.1 to 0.2 mol/L, the M(r) increased quickly from pH 3 to 6, and then maintained stable from pH 6 to 9, but slightly increased as the pH value was higher than 9. However, the M(r) of the alpha-1, 4/1, 6-glucan was slightly affected by either different concentrations of NaCl or different pH values. The beta-glucan existed in a super-helix structure in aqueous solution, which could be influenced by the NaCl concentration and pH value. These factors led to the different molecular aggregation states, and the increase or decrease of the M(r) of beta-glucans, displaying a variety of HPGPC behaviors.

Induction of apoptosis in SGC-7901 cells by polysaccharide-peptide GFPS1b from the cultured mycelia of Grifola frondosa GF9801

The biological function of GFPPS1b, a novel polysaccharide-peptide isolated from cultured mycelia of Grifola frondosa GF9801, was well investigated. GFPS1b has anti-tumor activity and can significantly inhibit the proliferation of SGC-7901 cells, whereas slightly influences the growth of human normal liver cell line L-02. When treated with GFPS1b, SGC-7901 cells showed typical apoptotic morphological features such as the loss of villus and appearance of apoptotic bodies on the cell surface, volume reduction, and chromatin condensation, by scanning electron microscopy (SEM) and fluorescent microscopy (Hoechst 33342). The results of flow cytometry analysis and annexin V-PI assay showed that the SGC-7901 cell cycle was arrested in the G(2)/M phase, the subdiploid peak of DNA characteristic of apoptotic was also observed, and the apoptosis ratio was about 15.08%. DNA isolated from SGC-7901 cells cultured with GFPS1b showed a typical DNA 'ladders' of apoptosis in agarose gel electrophoresis. Further investigation results showed that the apoptotic machinery of SGC-7901 induced by GFPS1b was associated with drop in mitochondrial trans-membrane potential, upregulation of Bax, downregulation of Bcl-2, and activation of caspase-3. Our finding suggests that GFPS1b could suppress SGC-7901 cell growth and reduce cell survival via arresting cell cycle and inducing apoptosis of tumor cells.

Effect of various natural products on growth of bladder cancer cells: two promising mushroom extracts

Despite the availability of several therapeutic options, a safer and more effective modality is urgently needed for treatment of bladder cancer. Specific immunotherapy is effective, but severe side effects limit its clinical use and underscore the need for unconventional therapies using less toxic substances. Many natural substances are touted for their medicinal aspects and side effect profiles, and some of these have been well characterized for their biological and medicinal properties. Accordingly, the effects on bladder cancer cells in vitro were investigated. Eight commercially available natural products were tested for possible effects on the growth of human bladder cancer T24 cells. This study demonstrated that two mushroom extracts, GD- and PL-fractions, induced a significant (>90 percent) growth reduction in 72 hours, whereas the remaining six products had no effect. Interestingly, non-toxic concentrations of the GD- or PL-fractions, when combined with a non-toxic concentration of vitamin C, became highly cytotoxic, resulting in >90-percent cell death. Thus, vitamin C appears to act synergistically with these fractions to potentiate their bioactivity (cytotoxicity). No other products tested demonstrated such a synergistic potentiation with vitamin C. The present study indicates that GD- and PL-fractions appear to have the most potent cytotoxic effect on human bladder cancer T24 cells. It is thus plausible that these substances could be used, solely or combined with conventional modalities, for the treatment of superficial bladder cancer.

The immune effects of edible fungus polysaccharides compounds in mice

Most of the current researches on immune function of fungus polysaccharides were based on individual component. Only a few studies were involved in the mixture of proprietary compounds from different species of edible fungi. The main objective of this study was to evaluate mice's immune effects of the mixed polysaccharides (ratio 1: 0.5: 0.5) extracted from Lentinus edodes, Ganoderma lucidium and Grifola frondosa. Kunming mice weighted 20+/-2 g (10 mice/group) was treated for 30 consecutive days with polysaccharides compounds, which were added to basal diet at three concentrations: 0.17, 0.33 and 1.00 g/kg body weight. Then the NK cells' activities, ratio thymus/body and spleen/body, macrophage's activities, hemolysis, and delayed hypersensitivity (DTH) were determined by standard methods. Polysaccharides compounds at the concentrations of 0.33 and 1.00 g/kg body weight significantly increased the thymus and NK cells activities (p< 0.01), as well as the ability of macrophages to phagocyte latex particles and the activity of macrophages (p< 0.05). The hemolytic test and DTH of the tested groups had no remarkable difference compared to that of the control group (p >0.05). The results indicated that the mixed polysaccharides compounds could enhance the cell immune of the mice.

Structural analysis of anti-tumor heteropolysaccharide GFPS1b from the cultured mycelia of Grifola frondosa GF9801

A 21-kDa heteropolysaccharide, coded as GFPS1b, was obtained from the cultured mycelia of Grifola frondosa GF9801 by hot-water extraction, ethanol precipitation, and fractioned by DEAE Sepharose Fast-flow, followed by the purification with Sephadex G-100 column chromatography using an AKTA purifier. It exhibited more potent anti-proliferative activity on MCF-7 cells than other polysaccharide fractions. GFPS1b was an acidic polysaccharide with approximately 16.60% protein and 4.3% uronic acid. Gas chromatography of absolute acid hydrolysate of GFPS1b suggested that it was composed of D-glucose, D-galactose, and L-arabinose with a molar ratio of 4:2:1. Periodate oxidation, Smith degradation, partial acid hydrolyzation, methylation analysis, FT-IR, and (1)H, (13)C NMR spectroscopy analysis revealed that GFPS1b had a backbone consisting of alpha-(1-->4)-linked D-galacopyranosyl and alpha-(1-->3)-linked D-glucopyranosyl residues substituted at O-6 with glycosyl residues composed of alpha-L-arabinose-(1-->4)-alpha-D-glucose (1--> linked residues.

Enhancement of umbilical cord blood cell hematopoiesis by maitake beta-glucan is mediated by granulocyte colony-stimulating factor production

Maitake beta-glucan (MBG) is an extract from the fruit body of the Grifola frondosa mushroom that is being widely used to treat cancer in Asia. We have previously reported that MBG enhances mouse bone marrow cell (BMC) hematopoiesis in vitro and protects BMC from doxorubicin (DOX) toxicity. In the current study, we investigated the ability of MBG to enhance hematopoiesis and to reduce the toxic effects of DOX on fresh human umbilical cord blood (CB) cells. MBG treatment significantly enhanced the colony formation unit (CFU) response of granulocytes-macrophages (CFU-GM response) over the whole dose range of 12.5 to 100 microg/ml (P < 0.05). The addition of MBG to DOX-treated CB cells significantly protected granulocyte-macrophage colony formation from the toxicity of DOX, which otherwise produced strong hematopoietic repression. MBG also partially replaced recombinant human granulocyte colony-stimulating factor (rhG-CSF), as shown by a significant augmentation of the CFU-GM response in the absence of rhG-CSF. We found that MBG induces granulocyte colony-stimulating factor (G-CSF) production in CB CD33+ monocytes, as detected by intracellular cytokine flow cytometric assessment. In contrast, we found that adult peripheral blood monocytes did not produce a significant G-CSF response to MBG, whereas both adult and CB monocytes produced G-CSF in response to lipopolysaccharide. These studies provide the first evidence that MBG induces hematopoietic stem cell proliferation and differentiation of CFU-GM in umbilical CB cells and acts directly to induce G-CSF.

Preparation of a chemically sulfated polysaccharide derived from Grifola frondosa and its potential biological activities

This report describes the preparation, characterization and potential biological activities of a chemically sulfated polysaccharide (S-GAP-P), which was derived from water-insoluble polysaccharide of Grifola frondosa mycelia. S-GAP-P was determined to be a glucan sulfate with the average molecular weight of 28 kDa and the sulfur content of 16.4%. The antitumor and immunomodulating activities of the sulfated derivative were estimated in vitro and in vivo. S-GAP-P inhibited the proliferation of SGC-7901 cells and induced apoptosis, in a dose-dependent manner. And the results from in vivo experiments demonstrated that S-GAP-P significantly inhibited the tumor growth and enhanced the peritoneal macrophages phagocytosis in S180-bearing mice. It is noteworthy that S-GAP-P could accelerate the antitumor activity of CTX and improve the immunocompetence damaged by CTX, suggesting the combination might increase cytotoxic efficacy and decrease toxicity of some chemotherapeutic agents in cancer treatment.

o-Orsellinaldehyde from the submerged culture of the edible mushroom Grifola frondosa exhibits selective cytotoxic effect against Hep 3B cells through apoptosis

The tumoricidal activity of a bioactive metabolite produced by submerged culture in a 2.1-L airlift fermentor of Grifola frondosa NTUS was investigated. After 14 days of cultivation, ethyl acetate extracts from the supernatant of culture broth (EES) were analyzed by cell viability assay. The IC50 of EES for cytotoxicity against human carcinoma cells (Hep 3B, Hep G2, HeLa, CL1-1) and normal human lung fibroblast MRC-5 was 78.4, 52.7, 77.6, 71.0, and 233.3 microg/mL, respectively. EES was further fractionated and a main cytotoxic compound, HE-5-5, was obtained. The IC50 of HE-5-5 based on the cell viability of Hep 3B and MRC-5 cells was 3.6 and 33.1 microg/mL, respectively. Thus, HE-5-5 showed a selective cytotoxic effect against Hep 3B cells and MRC-5. According to the UV, MS, and NMR data, HE-5-5 was identified as o-orsellinaldehyde. A DNA fragmentation assay together with the presence of a significant sub-G1 peak by flow cytometry suggested that o-orsellinaldehyde might mediate its cytotoxicity through apoptosis.

Inhibition of hepatitis B virus by D-fraction from Grifola frondosa: synergistic effect of combination with interferon-alpha in HepG2 2.2.15

In this study, D-fraction extracted from Grifola frondosa (GF-D) and its combination with human interferon alpha-2b (IFN) were investigated for the inhibitory effect on hepatitis B virus (HBV) in HepG2 2.2.15 cells (2.2.15 cells). HBV DNA and viral antigens were analyzed by a quantitative real-time polymerase chain reaction and end-point titration in radioimmunoassays, respectively. The results showed that GF-D or IFN alone could inhibit HBV DNA in 2.2.15 cells with the 50% inhibitory concentration (IC50) of 0.59 mg/ml and 1399 IU/ml, respectively. We further investigated the combination of GF-D and IFN for anti-HBV activity and found that they synergistically inhibited HBV replication in 2.2.15 cells. In combination with 0.45 mg/ml GF-D, the apparent IC50 value for IFN was 154 IU/ml. This 9-fold increase in antiviral activity of IFN suggested that GF-D could synergize with IFN. These results indicate that GF-D, in combination with IFN, might provide a potentially effective therapy against chronic HBV infections.