Breast cancer (BC) is the most commonly diagnosed tumor, remaining one of the leading causes of morbidity and mortality in females worldwide, with the highest rates in Western countries. Among metastatic BC (MBC), triple-negative breast cancer (TNBC) is characterized by the lack of expression of specific receptors, and differs from other subgroups of BC for its increased growth and fast spreading, with reduced treatment possibilities and a worse outcome. Actually, MBC patients are extremely prone to metastasis and consequent relapses, which affect distant target organs (e.g., brain, lung, bone and liver). Hence, the comprehension of biological mechanisms underlying the BC metastatization process is a key requirement to conceive/set up innovative medicinal strategies, with the goal to achieve long-lasting therapeutic efficacy, reducing adverse effects, and also ameliorating Quality of Life (QoL). Bioactive metabolites isolated from medicinal mushrooms (MMs) used as a supportive treatment, combined with conventional oncology, have recently gained wide interest. In fact, mounting evidence has revealed their peculiar promising immunomodulatory, anti-inflammatory and anticancer activities, even though these effects have to be further clarified. Among the group of most promising MMs are Lentinula edodes, Grifola frondosa, Ganoderma lucidum, Ophiocordyceps sinensis and Agaricus blazei, which are already employed in conventional cancer protocols in Asia and China. Recently, a growing number of studies have focused on the pharmacology and feasibility of MM-derived bioactive compounds as a novel valuable approach to propose an effective adjuvant therapy for MBC patients\' management. In this review, we summarized the current state of knowledge on the abovementioned MM-derived bioactive compounds and their therapeutic potential in clinical settings.

Calcium supplementation has been shown to be efficacious in mitigating the progression of senile osteoporosis (SOP) and reducing the incidence of osteoporotic fractures resulting from prolonged calcium shortage. In this study, Grifola frondosa (GF) peptides-calcium chelate were synthesized through the interaction between peptide from GF and CaCl2. The chelation reaction was shown to involve the participation of the amino and carboxyl groups in the peptide, as revealed by scanning electron microscope, Fourier-transform infrared, and ultraviolet spectrophotometry. Furthermore, a mouse model of (SOP) induced by d-galactose was established (SCXK-2018-0004). Results demonstrated that low dosage of low-molecular weight GF peptides-calcium chelates (LLgps-Ca) could significantly improve serum index and pathological features of bone tissue and reduce bone injury. Further research suggested that LLgps-Ca could ameliorate SOP by modulating the disrupted metabolic pathway, which includes focal adhesion, extracellular matrix receptor interaction, and PI3K-Akt signaling pathway. Using Western blot, the differentially expressed proteins were further confirmed. Thus, calciumchelating peptides from GF could serve as functional calcium agents to alleviate SOP.

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.
CONCLUSIONS: 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.

Myeloid derived suppressor cells (MDSCs) are known to accumulate in cancer patients and tumor-bearing mice, playing a significant role in promoting tumor growth. Depleting MDSCs has emerged as a potential therapeutic strategy for cancer. Here, we demonstrated that a fungal polysaccharide, extracted from Grifola frondosa, can effectively suppress breast tumorigenesis in mice by reducing the accumulation of MDSCs. Treatment with Grifola frondosa polysaccharide (GFI) leads to a substantial decrease in MDSCs in the blood and tumor tissue, and a potent inhibition of tumor growth. GFI treatment significantly reduces the number and proportion of MDSCs in the spleen, although this effect is not observed in the bone marrow. Further analysis reveals that GFI treatment primarily targets PMN-MDSCs, sparing M-MDSCs. Our research also highlights that GFI treatment has the dual effect of restoring and activating CD8+T cells, achieved through the downregulation of TIGIT expression and the upregulation of Granzyme B. Taken together, our findings suggest that GFI treatment effectively eliminates PMN-MDSCs in the spleen, leading to a reduction in MDSC numbers in circulation and tumor tissues, ultimately enhancing the antitumor immune response of CD8+T cells and inhibiting tumor growth. This study introduces a promising therapeutic agent for breast cancer.

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.

OBJECTIVE: Grifola frondosa, commonly referred to as the maitake mushroom, has been studied extensively to explore its potential health benefits. However, its anti-inflammatory effects in skin disorders have not been sufficiently elucidated. This study aimed to elucidate the anti-inflammatory role of the ethanol extract of G. frondosa in atopic dermatitis (AD) using in vivo and in vitro models.
METHODS: We investigated its impact on skin and spleen inflammatory responses in Dermatophagoides farinae extract (DFE)/1-chloro-2,4 dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in a mouse model. Additionally, we determined the immunosuppressive response and mechanism of G. frondosa by inducing atopic-like immune reactions in keratinocytes through tumor necrosis factor (TNF)-α/interferon (IFN)-γ stimulation.
RESULTS: Our study revealed that G. frondosa ameliorates clinical symptoms in an AD-like mouse model. These effects contributed to the suppression of Th1, Th2, Th17, and Th22 immune responses in the skin and spleen, leading to protection against cutaneous inflammation. Furthermore, G. frondosa inhibited the production of antibodies immunoglobulin (Ig)E and IgG2a in the serum of AD mice. Importantly, the inhibitory effect of G. frondosa on inflammatory cytokines in TNF-α/IFN-γ-stimulated AD-like keratinocytes was associated with the suppression of MAPK (Mitogen Activated Protein Kinase) pathway activation.
CONCLUSIONS: Collectively, these findings highlight the potential of G. frondosa as a novel therapeutic agent for AD treatment and prevention.

BACKGROUND: Grifola frondosa is a Basidiomycete fungus belonging to the family of Grifolaceae and the order of Polyporales. β-Glucans are the main polymers in G. frondosa, playing a crucial role in the physiology and representing the healthy benefits for humans. The membrane-integrated β-1, 3-glucan synthase (GLS) is responsible for glucan synthesis, cell wall assembly, differentiation and growth of the edible fungi. However, the structural/catalytic characteristics and mechanisms of β-1, 3-glucan synthases in G. frondosa are still unknown due to their extremely complex structures with multi-transmembranes and large molecular masses.
RESULTS: Herein, a β-1, 3-glucan synthase (GFGLS2) was purified and identified from the cultured mycelia with a specific activity of 60.01 pmol min-1 μg-1 for the first time. The GFGLS2 showed a strict specificity to UDP-glucose with a Vmax value of 1.29 ± 0.04 µM min-1 at pH 7.0 and synthesized β-1, 3-glucan with a maximum degree of polymerization (DP) of 62. Sequence Similarity Network (SSN) analysis revealed that GFGLS2 has a close relationship with others in Ganoderma sinense, Trametes coccinea, Polyporus brumalis, and Trametes pubescens. With the assistance of 3D structure modelling by AlphaFold 2, molecular docking and molecular dynamics simulations, the central hydrophilic domain (Class III) in GFGLS2 was the main active sites through binding the substrate UDP-glucose to 11 amino acid residues via hydrogen bonds, π-stacking and salt bridges.
CONCLUSIONS: The biochemical, 3D structural characterization and potential catalytic mechanism of a membrane-bound β-1, 3-glucan synthase GFGLS2 from cultured mycelia of G. frondosa were well investigated and would provide a reasonable full picture of β-1, 3-glucan synthesis in fungi.

Grifola frondosa is a valuable edible fungus with high nutritional and medicinal values. The mating systems of fungi not only offer practical strategies for breeding, but also have far-reaching effects on genetic variability. Grifola frondosa has been considered as a sexual species with a tetrapolar mating system based on little experimental data. In the present study, one group of test crosses and six groups of three-round mating experiments from two parental strains were conducted to determine the mating system in G. frondosa. A chi-squared test of the results of the test-cross mating experiments indicated that they satisfied Mendelian segregation, while a series of three-round mating experiments showed that Mendelian segregation was not satisfied, implying a segregation distortion phenomenon in G. frondosa. A genomic map of the G. frondosa strain, y59, grown from an LMCZ basidiospore, with 40.54 Mb and 12 chromosomes, was generated using genome, transcriptome and Hi-C sequencing technology. Based on the genomic annotation of G. frondosa, the mating-type loci A and B were located on chromosomes 1 and 11, respectively. The mating-type locus A coded for the β-fg protein, HD1, HD2 and MIP, in that order. The mating-type locus B consisted of six pheromone receptors (PRs) and five pheromone precursors (PPs) in a crossed order. Moreover, both HD and PR loci may have only one sublocus that determines the mating type in G. frondosa. The nonsynonymous SNP and indel mutations between the A1B1 and A2B2 mating-type strains and the reference genome of y59 only occurred on genes HD2 and PR1/2, preliminarily confirming that the mating type of the y59 strain was A1B2 and not A1B1. Based on the genetic evidence and the more reliable molecular evidence, the results reveal that the mating system of G. frondosa is tetrapolar. This study has important implications for the genetics and hybrid breeding of G. 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.

Introduction: Polysaccharides, key components present in Grifola frondosa, can be divided into those derived from fruiting bodies, mycelium, and fermentation broth based on their source. The structure of G. frondosa fruiting body-derived polysaccharides has been fully characterized. However, the structure of G. frondosa mycelium-derived polysaccharides remains to be elucidated. Methods: In this study, we obtained mycelia from G. frondosa by liquid fermentation and extracted them with water and alkaline solution. Then, the mycelia were isolated and purified to obtain homogeneity and systematically characterized by methylation and FT infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Results and discussion: Structural analysis showed that two neutral fractions (WGFP-N-a and AGFP-N-a1) have a common backbone composed of α-1,6-D-Me-Galp and α-1,6-D-Galp that were substituted at O-2 by 1,2-Manp, α-1,3-L-Fucp, and α-T-D-Manp and thus are identified as fucomannogalactans. WGFP-A-a, AGFP-A-b, and AGFP-A-c are β-1,6-glucans with different molecular weights and are branched with β-1,3-D-Glcp and T-D-Glcp at the O-3 of Glc. Our results provide important structural information about G. frondosa mycelium-derived polysaccharides and provide the basis for their further development and application.