An alkali-extracted neutral heteropolysaccharide from Phellinus nigricans used as an immunopotentiator in immunosuppressed mice by activating macrophages.

A neutral heteropolysaccharide (PNANb) was isolated with alkali (0.1 M NaOH) from mycelia of Phellinus nigricans, and the structure, immunostimulating activity and some of the underlying molecular mechanisms of action of PNANb were explored in the current study. PNANb (14.95 kDa) predominantly consisted of Gal, Glc, and Man with minor Fuc. GC-MS and NMR analyses indicated that the backbone of PNANb was mainly composed of 6-α-Galp, 2,6-α-Galp with minor 3,6-ß-Glcp, which was substituted with complex side chains at C-2 of 2,6-α-Galp and C-3 of 3,6-ß-Glcp. Notably, PNANb (50 or 100 mg/kg) possessed immunoprotective effects in cyclophosphamide (Cy)-induced immunosuppressed C57BL/6 mice, which was supported by evidence including the enhancement of spleen and thymus indices, levels of serum immunoglobulins (IgG, IgM) and cytokines (IFN-γ, IL-2, IL-4, IL-10), and macrophage activity. However, the immunostimulation effects of PNANb were decreased when macrophages were depleted, underscoring the essential role of macrophages in the beneficial effects of PNANb in Cy-induced immunosuppressed mice. Further investigations in vitro indicated that PNANb activated macrophages through MAPK/NF-κB signaling pathways mediated by Toll-like receptor 4. Therefore, PNANb can serve as a prospective immunopotentiator in immunosuppression.

Oral exosome-like nanovesicles from Phellinus linteus suppress metastatic hepatocellular carcinoma by reactive oxygen species generation and microbiota rebalancing.

The biomedical application of nanotechnology in cancer treatment has demonstrated significant potential for improving treatment efficiencies and ameliorating adverse effects. However, the medical translation of nanotechnology-based nanomedicines faces challenges including hazardous environmental effects, difficulties in large-scale production, and possible excessive costs. In the present study, we extracted and purified natural exosome-like nanoparticles (ELNs) from Phellinus linteus. These nanoparticles (denoted as P-ELNs) had an average particle size of 154.1 nm, displayed a negative zeta potential of -31.3 mV, and maintained stability in the gastrointestinal tract. Furthermore, P-ELNs were found to contain a diverse array of functional components, including lipids and pharmacologically active small-molecule constituents. In vitro investigations suggested that they exhibited high internalization efficiency in liver tumor cells (Hepa 1-6) and exerted significant anti-proliferative, anti-migratory, and anti-invasive effects against Hepa 1-6 cells. Strikingly, the therapeutic outcomes of oral P-ELNs were confirmed in an animal model of metastatic hepatocellular carcinoma by amplifying reactive oxygen species (ROS) and rebalancing the gut microbiome. These findings demonstrate the potential of P-ELNs as a promising oral therapeutic platform for liver cancer treatment.

Research Progress of Bioactive Components in Sanghuangporus spp.

The species in Sanghuangporus are a group of edible mushrooms with a long history of oral use in East Asia as a health-improvement method. They should be classified under the genus Sanghuangporus rather than mistakenly in Phellinus or Inonotus. The major components in this genus consist of polysaccharides, polyphenols, triterpenoids, and flavonoids, all of which exist in the fruiting bodies and mycelia. For extraction, studies have shown methods using hot water, ethanol, DES solvent, and alkaline, followed by purification methods including traditional anion column, Sevag solution, macroporous resin, and magnetic polymers. Proven by modern medical technology, these components possess promising anti-inflammatory, antioxidative, antitumor, and immunoregulation effects; additionally, they have health-improving effects including pulmonary protection, hypoglycemic properties, sleep improvement, gout mitigation, antiaging, neuroprotection, and muscle-strengthening abilities. Several toxicity studies have revealed their safety and recommend a dose of 1 g/kg for mice. As a newly emerged concept, functional food can provide not only life-sustaining nutrients but also some health-improving effects. In conclusion, we substantiate Sanghuang as a functional food by comprehensively presenting information on extraction and purification methods, component medical and structural properties, and nontoxicity, hoping to benefit the development of Sanghuang species as a group of functional food.

Comparative Transcriptome Analysis of Candidate Genes Associated with Mycelia Growth from a He-Ne Laser with Pulsed Light Mutant of Phellinus igniarius (Agaricomycetes).

A mutant Phellinus igniarius JQ9 with higher mycelial production was screened out by He-Ne laser with pulsed light irradiation, the mechanism underlying the higher mycelial production is still unknown. This study aims to obtain a comprehensive transcriptome assembly during the Ph. igniarius liquid fermentation and characterize the key genes associated with the mycelial growth and metabolism in Ph. igniarius JQ9. Our transcriptome data of Ph. iniarius JQ9 and the wild strain were obtained with the Illumina platform comparative transcriptome sequencing technology. The results showed that among all the 346 differentially expressed genes (DEGs), 245 were upregulated and 101 were downregulated. Candidate genes encoding endoglucanase, beta-glucosidase, cellulose 1,4-beta-cellobiosidase, glycoside hydrolase family 61 protein, were proposed to participate in the carbohydrate utilization from KEGG enrichment of the starch and sucrose metabolism pathways were upregulated in Ph. igniarius JQ9. In addition, three candidate genes encoding the laccase and another two candidate genes related with the cell growth were higher expressed in Ph. igniarius JQ9 than in the wild type of strain (CK). Analysis of these data revealed that increased these related carbohydrate metabolism candidate genes underlying one crucial way may cause the higher mycelia production.

Protoilludane-Type and Related Nor-Sesquiterpenes from Phellinus hartigii and Their Anti-Hypertrophic Activities in Rat Cardiomyocytes.

Three nor-sesquiterpenes, phellinharts A-C (1-3), isolated from Phellinus hartigii, exhibited unprecedented protoilludane and cerapicane-type structures. The structures of compounds 1-3 were elucidated via spectroscopic analysis, quantum chemical calculations, and X-ray diffraction. Potential biogenic pathways involving demethylation, ring cleavage, and rearrangement were proposed. Compounds 1-3 displayed potent anti-hypertrophic activities with low cytotoxicity (CC50 > 50 µM) in rat cardiomyocytes, underscoring their therapeutic potential.

Effect of the Combination of Clostridium butyricum and Mycelium of Phellinus igniarius on Intestinal Microbiota and Serum Metabolites in DSS-Induced Colitis.

Clostridium butyricum (CB) and Phellinus igniarius (PI) have anti-inflammatory, immune regulation, anti-tumor, and other functions. This study aimed to explore the therapeutic effect of CB and mycelium of PI (MPI) alone and in combination on colitis mice induced by dextran sodium sulfate (DSS). Mice were randomly assigned to five groups: (1) control (CTRL), (2) DSS, (3) CB, (4) MPI, and (5) CB + MPI (CON). The weight of the mice was recorded daily during the experiment, and the length of the colon was measured on the last day of the experiment. The colons were collected for hematoxylin and eosin staining, colon contents were collected for intestinal flora analysis, and serum was collected for metabolite analysis. The results showed that compared with the DSS group, CB, MPI, and CON treatments inhibited the weight loss and colon length shortening caused by DSS, significantly increased the concentrations of interleukin (IL)-4, IL-10, and superoxide dismutase, and significantly decreased the concentrations of IL-6, tumor necrosis factor-α, and myeloperoxidase. Gene sequence analysis of 16S rRNA showed that CB, MPI, and CON treatments changed the composition and structure of intestinal microorganisms. Metabolome results showed that CB, MPI, and CON treatments changed serum metabolites in DSS-treated mice, including dodecenoylcarnitine, L-urobilinogen, and citric acid. In conclusion, CB, MPI, and CON treatments alleviated DSS-induced colitis in mice by regulating intestinal flora and metabolites, with the CON group having the best effect.

A dihydromyricetin-loaded phellinus igniarius polysaccharide/l-arginine modified chitosan-based hydrogel for promoting wound recovery in diabetic mice via JNK and TGF-ß/Smad signaling pathway.

The wound of diabetes has long-term excessive inflammation leading to wound fibrosis and scar formation. In the process of diabetic wound healing, good wound dressing is required for intervention. In this study, we designed a dihydromyricetin-loaded hydrogel (PCD) based on phellinus igniarius polysaccharide and l-arginine modified chitosan as an alternative material to promote diabetes wound healing. PCD had a uniform porous structure, good thermal stability, excellent mechanical properties, high water absorption, excellent antioxidant and anti-inflammatory activities and good biocompatibility and biodegradability. In addition, in the full-thickness skin trauma model of diabetes, PCD significantly inhibited the JNK signaling pathway to reduce inflammatory response, and significantly down-regulated the expression of TGF-ß1, Smad2, Smad3 and Smad4 to directly inhibit the TGF-ß/Smad signaling pathway to accelerate wound healing and slow down scar formation in diabetes mice. Therefore, PCD has a broad application prospect in promoting diabetes wound healing.

Phellinus igniarius polysaccharides induced mitochondrial apoptosis of hepatic carcinoma by enhancing reactive oxygen species-mediated AKT/p53 signalling pathways.

Phellinus igniarius (PI) has various kinds of biological activities, such as antitumour activities, and polysaccharides are one of its main components. In this study, polysaccharides from PI (PIP) were prepared, purified, analysed for their structure and investigated for their antitumour activity and mechanism in vitro. PIP consists of 12138 kDa of carbohydrates containing 90.5 ± 1.6% neutral carbohydrates. PIP consists of glucose, galactose, mannose, xylose, D-fructose, L-guluronic acid, glucosamine hydrochloride, rhamnose, arabinose and D-mannoturonic acid. PIP can significantly inhibit HepG2 cell proliferation, induce cell apoptosis and also inhibited migration and invasion in a concentration-dependent manner. PIP increased reactive oxygen species (ROS), increased the expression of p53, and induced cytochrome c release into the cytoplasm to activate caspase-3. PIP is a promising potential candidate for the therapeutic treatment of hepatic carcinoma via the ROS-mediated mitochondrial apoptosis pathway.

Inhibitory Effect of Styrylpyrone Extract of Phellinus linteus on Hepatic Steatosis in HepG2 Cells.

The prevalence of nonalcoholic fatty liver disease (NAFLD) is estimated to be approximately about 25.24% of the population worldwide. NAFLD is a complex syndrome and is characterized by a simple benign hepatocyte steatosis to more severe steatohepatitis in the liver pathology. Phellinus linteus (PL) is traditionally used as a hepatoprotective supplement. Styrylpyrone-enriched extract (SPEE) obtained from the PL mycelia has been shown to have potential inhibition effects on high-fat- and high-fructose-diet-induced NAFLD. In the continuous study, we aimed to explore the inhibitory effects of SPEE on free fatty acid mixture O/P [oleic acid (OA): palmitic acid (PA); 2:1, molar ratio]-induced lipid accumulation in HepG2 cells. Results showed that SPEE presented the highest free radical scavenging ability on DPPH and ABTS, and reducing power on ferric ions, better than that of partitions obtained from n-hexane, n-butanol and distilled water. In free-fatty-acid-induced lipid accumulation in HepG2 cells, SPEE showed an inhibition effect on O/P-induced lipid accumulation of 27% at a dosage of 500 µg/mL. As compared to the O/P induction group, the antioxidant activities of superoxide dismutase, glutathione peroxidase and catalase were enhanced by 73%, 67% and 35%, respectively, in the SPEE group. In addition, the inflammatory factors (TNF-α, IL-6 and IL-1ß) were significantly down-regulated by the SPEE treatment. The expressions of anti-adipogenic genes involved in hepatic lipid metabolism of 5' adenosine monophosphate (AMP)-activated protein kinase (AMPK), sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) were enhanced in the SPEE supplemented HepG2 cells. In the protein expression study, p-AMPK, SIRT1 and PGC1-α were significantly increased to 121, 72 and 62%, respectively, after the treatment of SPEE. Conclusively, the styrylpyrone-enriched extract SPEE can ameliorate lipid accumulation and decrease inflammation and oxidative stress through the activation of SIRT1/AMPK/PGC1-α pathways.

Pulsed Light Mutagenesis of the Willow Bracket Mushroom, Phellinus igniarius (Agaricomycetes), for Enhanced Production of Flavonoids, Laccase, and Fermentation Biomass.

Phellinus igniarius is a medicinal fungus possessing potent therapeutic activity due to the polysaccharides, polyphenols, flavonoids, and other secondary metabolites they contain. Laccases are crucial enzymes involved in lignin degradation in Ph. igniarius and offer great potential to accomplish several bioprocesses. To generate Ph. igniarius strains with high biomass, flavonoid, and laccase activity, we used pulsed light (PL) technology for mutagenesis of Ph. igniarius protoplasts and screened for mutants with high biomass, flavonoid, and laccase activity. At the irradiation power of 100 J, treated distance 8.5 cm, irradiation frequency was 0.5 s/time, three times treatments, after five generations of selection, three mutants were obtained with higher biomass production. Compared with control, the mycelium biomass and the flavonoid production of the screened mutant strain QB72 were increased 20.87% and 53.51%, respectively. The total amount of the accumulated extracellular laccase of the QB72 in the first 6 and 8 days increased 23.38% and 22.37% respectively, and over the total 16 days it increased 9.62%. In addition, RAPD analysis results indicated that the genetic materials of the mutant QB72 were altered. PL mutagenesis method has great potential for developing strains, especially Phellinus.

Efficacy of Phellinus linteus extract on immunity enhancement: A CONSORT-randomized, double-blind, placebo-controlled pilot trial.

BACKGROUND: Immunity is a major system that defends the human body from the outside. Recently, interest in foods related to immunity has been increasing. METHODS: The purpose of this clinical trial was to determine the safety and efficacy of Phellinus linteus (PL) extract in improving immune function. A total of 30 participants were randomly assigned to 3 groups: the PL1000 group (n = 10) took 1000 mg of PL extract and 1000 mg of dextrin per day; the PL2000 group (n = 10) took 2000 mg of PL extract per day; and the placebo group (n = 10) took 2000 mg of dextrin per day. All participants took 2 capsules twice a day for 8 weeks. We measured their natural killer cell activity and cytokine levels in blood before and after consuming the clinical trial food. Variables were also investigated to evaluate safety, such as adverse reactions, vital signs, and abnormal findings. Student t test or the Mann-Whitney U test, a paired t test or the Wilcoxon signed-rank test, a chi-square test, analysis of variance, and Kruskal-Wallis test were conducted according to the characteristics of the data to compare the differences between each group before and after participants ate the clinical trial food. RESULTS: The natural killer cell activity and interleukin-6 levels of the PL1000 group tended to improve compared to those of the placebo group. Immunoglobulin G1, immunoglobulin G2, and immunoglobulin M levels did not show significant changes, but tended to improve in the PL1000 and PL2000 groups compared to those of the placebo group. Both the Per Protocol and Intention to Treat populations had improved validation parameters. It is safe because no hazards were found in the safety assessment. CONCLUSION: PL extract can help improve immunity. Evidences to conduct the main clinical trial is secured through this pilot study. A future large-scale main trial will be conducted based on this pilot study results.

Recent advances in the bioactive polysaccharides and other key components from Phellinus spp. and their pharmacological effects: A review.

Phellinus spp. is one of the largest genera of Hymenochaetaceae with approximately 220 species, such as P. vaninii, P. buamii, P. linteus, and P. igniarius, these species are considered as precious food supplements and medicinal ingredients in China, Korea, Japan, and other Asian countries for over 2000 years. Phellinus spp. contains abundant bioactive polysaccharides and other key components (e.g., phenolics, terpenes, steroids, etc.). Pharmacological investigations have confirmed that bioactive polysaccharides and other important secondary metabolites from Phellinus spp. possess multiple health-promoting benefits, including antitumor, immunomodulatory, anti-inflammatory, antidiabetic, antioxidant, and antimicrobial effects. However, comprehensive evaluations on the preparation and structural characteristics, bioactivities, and toxicology of these functional components (e.g., polysaccharides, phenolics, terpenes, steroids) from various Phellinus spp. species are very limited, which may restrict the practical application of Phellinus spp. This review summarizes the physicochemical characteristics, pharmacological activities, and possible mechanisms of bioactive components from Phellinus spp. according to published studies from 2017 to 2022. It also surveyed the toxicological assessment for safety and applications of different Phellinus spp. species. This review aims to provide useful references and promising directions for the comprehensive development and utilization of Phellinus spp. in functional foods, pharmaceuticals, and cosmetics.

Phelliribsin B: A New Styrylpyrone Derivative from the Medicinal Fungus Phellinus ribis.

A novel styrylpyrone derivative, named phelliribsin B (1), as well as four biogenetically related known compounds, phellifuropyranone A (2), inoscavin C (3), inoscavin A (4), and inoscavin D (5) were separated and purified from the medicinal fungus Phellinus ribis. The structure of phelliribsin B was determined by spectroscopic analysis, and the absolute configuration was assigned by experimental and calculated ECD data. Additionally, the plausible biosynthetic pathway of 1 was also proposed. Compound 1 showed moderately cytotoxic activity against HepG2 and SKOV-3 tumor cell lines with IC50 values of 32.71 and 57.89 µM, respectively. Based on the results of cytotoxicity against HepG2 tumor cells, the structure-activity relationship of compounds 1-4 with similar skeletons was discussed. The styrylpyrone derivatives with similar skeletons have moderately cytotoxic activity and have the potential to play an important role in the anti-tumor treatment.

Effects of Phellinus linteus extract on immunity improvement: A CONSORT-randomized, double-blinded, placebo-controlled trial.

BACKGROUND: Immunity protects the body from external threats and prevents the development of cancer. Biological response modifiers extracted from natural sources are being actively studied, and the immunostimulatory and anticancer effects of various types of fungi have been reported. However, there are no previous clinical studies on the immune-enhancing effect of Phellinus linteus (PL). Lactate dehydrogenase cytotoxicity assay is a prerequisite in order to get approval for using PL as a raw material in functional supplements and medicines in Korea. However, due to the absence of precedent clinical trials, the use of PL in supplements has been hindered. but there is no precedent clinical trial using it. We conducted a randomized, double-blinded, placebo-controlled trial to confirm the efficacy and safety of PL extract for the improvement of immunity using the lactate dehydrogenase cytotoxicity assay. METHODS: A total of 98 subjects were enrolled and randomly assigned to 2 groups. Subjects in the PL and placebo groups received 1000 mg of PL extract and 1000 mg of dextrin per day, respectively (one capsule, twice every day for 8 weeks). The primary outcome measured was the activity of natural killer cells. Secondary outcomes were the levels of TNF-α, IFN-γ, IL-1ß, IL-2, IL-6, IL-12, IgG1, IgG2, and IgM. Safety was evaluated using laboratory tests. RESULTS: NK cell activity was significantly increased in the PL group compared to the placebo group (P < .05). Despite the absence of significant changes in secondary outcomes, there was a tendency for improvement in the PL group. PL extract-related adverse outcomes, particularly in liver and renal function, were not observed. CONCLUSION: PL extract may improve immunity and is safe to be consumed orally.

Receptor-ligand affinity-based screening and isolation of water-soluble 5-lipoxygenase inhibitors from Phellinus igniarius.

We developed an efficient combination method for extraction, biological activity screening, and preparation of 5-lipoxygenase inhibitors from Phellinus igniarius. 5-Lipoxygenase inhibitors were rapidly screened using ultrafiltration-liquid chromatography based on the receptor-ligand affinity. Parameters such as extraction time, extraction times, and temperature as well as liquid-solid ratio were optimized using response surface methodology to maximize the total yield of the three target compounds. Next, bioactive ingredients were isolated using high-speed countercurrent chromatography and semi-preparative liquid chromatography. Three active ingredients, phellibaumin E, protocatechuic aldehyde, and osmundacetone, were obtained via ultrafiltration-liquid chromatography. Subsequently, the potential anti-dementia effects of the obtained bioactive compounds were verified using molecular docking assays. The above-mentioned target compounds, with purities of 98.82%, 98.89%, and 99.51%, respectively, were separated using a two-phase solvent system consisting of n-hexane-ethyl acetate-ethanol-water (2.5:2:0.75:3, v/v/v/v) coupled with semi-preparative liquid chromatography.

Antioxidant properties of fortified yogurt with medicinal mushrooms from Phellinus species.

In light of the powerful therapeutic features of Phellinus species and due to the absence of toxic compounds, our investigations were aimed at screening of the antioxidant profile of fortified yogurts with hot water extracts from Phellinus torulosus and Phellinus igniarius leveled to 10%, 5%, and 1% final fortification concentrations after acknowledging their superior bioactive content and radical scavenging capacities (59.77% and 56.73% of DPPH inhibition, respectively) versus cold water extracts (29.87% and 33.18% inhibition rates). Fortified samples signified dose-dependent increases in their inhibition rates during the storage period, with significant differences between 10% fortifications on the 7 day of storage in favor of the samples fortified with P. torulosus. Explicitly, P. torulosus showed 16% higher DPPH and 62.5% higher LPO neutralizing activity than yogurt enriched with P. igniarius. However, prolonged refrigeration tended to equalize antioxidant profiles in both fortified yogurts. Total titratable acidity and pH levels of the fortified yogurts as most important parameters for consumer acceptance were unaltered during storage. PRACTICAL APPLICATIONS: It is a common scientific perception that bioactive compounds present in wild medicinal fungi are the main contributors for their in vitro antioxidant efficiency. On account of these attributes, Phellinus species have been exploited in Far East Asia as safe remedies for many disorders thus making them attractive fortifying ingredients; however, according to our knowledge these mushrooms have never been used as natural additives in beverages. Given the current popularity of yogurt consumption as seen from the global market profits, as well as experimental evidences of enhanced potency of extract in comparison with powder due to maximal bioavailability of antioxidants, it is our belief that this study will increase the interest in the manufacture of functional foods with extracts from wild mushrooms.

Chitosan-modified Phellinus igniarius polysaccharide PLGA nanoparticles ameliorated inflammatory bowel disease.

In many clinical studies, prebiotics have been used as adjuvant therapy for inflammatory bowel disease (IBD). Phellinus igniarius polysaccharide (PIP) possesses great anti-inflammatory and prebiotic activities. Herein, we developed an orally deliverable PIP-loaded chitosan-modified PLGA nanomedicine (CS-PIPP) to investigate its anti-inflammatory effect in vitro and in vivo. Dextran sodium sulfate (DSS)-induced colitis model was established to evaluate the preventive effect of CS-PIPP on IBD. This study characterized that CS-PIPP had a size of 288.7 ± 5.49 nm, positive zeta potential, and showed good stability over four weeks. The in-vitro study suggested that CS-PIPP had enhanced phagocytosis by macrophages, which could further significantly inhibit M1-like macrophages phenotype and regulate lipopolysaccharide (LPS)-induced inflammatory cytokines. The in-vivo study revealed that CS-PIPP prominently prevented intestinal inflammatory damage and protected the integrity of the intestinal barrier. Moreover, CS-PIPP increased the contents of short-chain fatty acids (SCFAs) and positively regulated the gut microbiota. Specifically, CS-PIPP reduced enteropathogenic microorganisms while increasing the beneficial microbiota, including Lactobacillus and Akkermansia, which revealed the potential of CS-PIPP as prebiotics. Generally, CS-PIPP promoted the anti-inflammatory effect of PIP, so it could be regarded as a novel and potent nanoformulation to treat IBD.

Structural diversity and bioactivity of polysaccharides from medicinal mushroom Phellinus spp.: A review.

Phellinus spp., an important medicinal fungus mushroom extensively cultivated and consumed in East Asia for over 2000 years, is traditionally considered a precious food supplement and medicinal ingredient. Published studies showed that the polysaccharides are major bioactive macromolecules from Phellinus spp. (PPs) with multiple health-promoting effects, including immunomodulatory, anti-cancer, anti-inflammatory, hepatoprotective, hypoglycemic, hypolipidemic, antioxidant, and other bioactivities. Although the polysaccharides extracted from the fruiting body, mycelium, and fermentation broth of Phellinus spp. have been extensively studied for the extraction and purification methods, structural characteristics, and pharmacological activities, the knowledge for their structures and bioactivity relationship, toxicologic effects, and pharmacokinetic profile is limited. This review systematically summarizes the recent progress in the isolation and purification, chemical structures, bioactivities, and the underlying mechanisms of PPs. Information from this review provides insights into the further development of polysaccharides from PPs as therapeutic agents and functional foods.

Optimal Liquid Inoculum Conditions and Grain Medium Enhanced Hispidin Production by Species of Genus Phellinus (Agaricomycetes) in Solid-State Fermentation.

This study aimed 1) to screen a high hispidin production strain from 12 strains of genus Phellinus and 2) to evaluate the effects of liquid inoculum conditions and grain medium on this strain's hispidin production levels after solid-state fermentation. The results showed that Ph. linteus 04 led to the highest hispidin production; this strain was then selected to elucidate the optimal liquid inoculum conditions and grain medium for hispidin production. Various liquid inoculum conditions were evaluated, and the highest hispidin yield, specific productivity of hispidin, and total content of hispidin were found to be optimal at 1 week of liquid inoculum culture time, cultured with potato dextrose broth, and using a 10% inoculum rate, with each condition resulting in 0.350, 0.325, and 0.328 mg/g dry weight of mycelium, 0.352, 0.251, and 0.249 µg/mg of specific productivity per week, and 57.90, 60.23, and 61.77 mg/kg dry weight of brown rice medium, respectively. These liquid inoculum conditions were then used to determine the appropriate grain medium for hispidin production. The highest hispidin yield and total content of hispidin were observed in pearl barley (1.107 mg/g dry weight of mycelium and 199.76 mg/kg dry weight of pearl barley), which led to results that were 4.73-fold and 5.35-fold higher than those of the control (brown rice medium). Overall, this study shows that Ph. linteus hispidin production can be enhanced by solid-state fermentation using optimal liquid inoculum conditions and the appropriate grain medium.

Phenolic compounds of Phellinus spp. with antibacterial and antiviral activities.

Phellinus Quél is one of the largest genera of Hymenochaetaceae; it comprises about 220 species widely distributed on Earth. Most Phellinus species are lignicolous mushrooms that accumulate bioactive compounds. This research studied the phenolic composition of Phellinus spp. and their relationship with antibacterial and antiviral capacity. Phenolics were extracted from Phellinus badius, P. fastuosus, and P. grenadensis; their antiviral and antibacterial activities were evaluated against Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica, and Escherichia coli O157: H7; and the bacteriophages MS2 and Φ- × 174. Gallic acid, chlorogenic acid, caffeic acid, epicatechin, ferulic acid, catechin, 1,3-dicaffeoylquinic acid, p-coumaric acid, and rutin were found in different proportions among Phellinus spp. Total phenolic content ranged from 96 to 209 mg GAE/g, and total flavonoids from 10 to 27 QE/g. The minimum inhibitory concentrations of P. badius, P. grenadensis, and P. fastuosus against E. coli O157: H7 were 13, 20, and 27 mg/mL, against S. enterica were 20, 30, and 15 mg/mL, and against L. monocytogenes were 10, 15, and 25 mg/mL, respectively. The phenolic content was better correlated with the antibacterial effect against E. coli O157: H7 and L. monocytogenes (r = 0.8-0.9), but not against S. enterica (r = 0.05). The antiviral activity of the extracts (0.9 mg/mL) was 29 to 41% against MS2 and 27 to 38% for Φ-X174 virus (r = 0.8-0.9). In silico analysis showed binding energy values of - 7.9 and - 4.8 kcal/mol between the identified phenolic compounds and the M and G proteins of each virus. The antibacterial and antiviral properties of Phellinus species were correlated with the phenolic content.