Hepatoprotective Principles and Other Chemical Constituents from the Mycelium of Phellinus linteus

Phellinus linteus polysaccharides: A review on their preparation, structure-activity relationships, and drug delivery systems

Phellinus linteus polysaccharides exhibit antitumor, immunomodulatory, anti-inflammatory, and antioxidant properties, mitigate insulin resistance, and enhance the diversity and abundance of gut microbiota. However, the bioactivities of P. linteus polysaccharides vary owing to the complex structure, thereby, limiting their application. Various processing strategies have been employed to modify them for improving the functional properties and yield. Herein, we compare the primary modes of extraction and purification employed to improve the yield and purity, review the structure-activity relationships, and discuss the application of P. linteus polysaccharides using nano-carriers for the encapsulation and delivery of various drugs to improve bioactivity. The limitations and future perspectives are also discussed. Exploring the bioactivity, structure-activity relationship, processing methods, and delivery routes of P. linteus polysaccharides will facilitate the development of functional foods and dietary supplements rich in P. linteus polysaccharides.

Characterisation of indole alkaloids and phenolic acids from wild mushroom Tropicoporus linteus and its chemical profiles compared with other Sanghuang mushrooms

Two new indole alkaloids, 1-methylindole-7-methoxy-3-carboxaldehyde (2) and 7-methoxyindole-3-carboxaldehyde (4), together with 7-methoxyindole-3-carboxylic acid methyl ester (1) and 1-methylindole-3-carbaldehyde (3) were isolated from the fruiting bodies of wild Sanghuang mushroom Tropicoporus linteus (TL663). TLC, 1H-NMR and LC-MS chemical profiles of this mushroom compared with other three genera of wild Sanghuang mushroom extracts were investigated. The TLC, 1H-NMR and LC-MS profiles of TL663 and Sanghuangporus sanghuang (SS664) were similar and significantly different from other mushrooms. These two samples indicated the same TLC chromatograms by showing prominent bands of 1 - 4 when observed under UV 254 nm and having sharp aldehyde proton signals of 3-carboxaldehyde indole type in 1H-NMR spectra. From LC-MS analyses, peaks of isolated compounds 1 - 4 and indole-3-carboxaldehyde (5) in TL663 extract and peaks of protocatechuic acid (6), caffeic aldehyde (7), caffeic acid (8) and 3,4-dihydroxybenzalacetone (9) phenolic acids in TL663 fraction were identified.

Evaluation of lung protection of Sanghuangporus sanghuang through TLR4/NF-κB/MAPK, keap1/Nrf2/HO-1, CaMKK/AMPK/Sirt1, and TGF-β/SMAD3 signaling pathways mediating apoptosis and autophagy

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial pneumonia characterized by chronic and progressive fibrosis with an unknown etiology. Previous pharmacological studies have shown that Sanghuangporus sanghuang possesses various beneficial properties including immunomodulatory, hepatoprotective, antitumor, antidiabetic, anti-inflammatory, and neuroprotective effects. This study used a bleomycin (BLM)-induced IPF mouse model to illustrate the possible benefits of SS in ameliorating IPF. BLM was administered on day 1 to establish a pulmonary fibrosis mouse model, and SS was administered through oral gavage for 21 d. Hematoxylin and eosin (H&E) and Masson's trichrome staining results showed that SS significantly reduced tissue damage and decreased fibrosis expression. We observed that SS treatment resulted in a substantial lowering in the level of pro-inflammatory cytokines like TGF-β, TNF-α, IL-1β, and IL-6 as well as MPO. In addition, we observed a notable increase in glutathione (GSH) levels. Western blot analysis of SS showed that it reduces inflammatory factors (TWEAK, iNOS, and COX-2), MAPK (JNK, p-ERK, and p-38), fibrosis-related molecules (TGF-β, SMAD3, fibronectin, collagen, α-SMA, MMP2, and MMP9), apoptosis (p53, p21, and Bax), and autophagy (Beclin-1, LC3A/B-I/II, and p62), and notably increases caspase 3, Bcl-2, and antioxidant (Catalase, GPx3, and SOD-1) levels. SS alleviates IPF by regulating the TLR4/NF-κB/MAPK, Keap1/Nrf2/HO-1, CaMKK/AMPK/Sirt1, and TGF-β/SMAD3 pathways. These results suggest that SS has a pharmacological activity that protects the lungs and has the potential to improve pulmonary fibrosis.

Polysaccharides from Phellinus linteus: A systematic review of their extractions, purifications, structures and functions

Phellinus linteus (P. linteus) is a famous Chinese medicine and has a long history in China. In recent years, P. linteus polysaccharides (PLPs) have attracted extensive attention because of their biological activities such as anti-bacteria, anti-aging, anti-oxidation, anti-inflammation, anti-tumor, hepatoprotective effect and hypoglycemic effect. In this review, we systemically summarized the advances in extractions, purifications and structural characterizations of PLPs, and also analyzed their biological functions and molecular mechanisms. Meanwhile, the structure-activity relationships of PLPs are closely related to their anti-oxidation and anti-tumor activities. So far, the applications of PLPs are still very limited, further exploring structure-activity relationships, biological functions and their mechanisms of PLPs will promote to develop functional foods.

Immunostimulatory Effect of Postbiotics Prepared from Phellinus linteus Mycelial Submerged Culture via Activation of Spleen and Peyer's Patch in C3H/HeN Mice

Medicinal mushrooms are an important natural resource promoting health benefits. Herein, Phellinus linteus mycelia were prepared under submerged cultivation, the mycelium-containing culture broth was extracted as a whole to obtain the postbiotic materials (PLME), and its effect on the immune system was evaluated in normal C3H/HeN mice. Oral administration of PLME for 4 weeks was well tolerated and safe. In the PLME-administered groups, in addition to the production of immunostimulatory cytokines, such as interferon gamma (IFN-γ), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6), the mitogenic activity was significantly increased. PLME administration also significantly increased the levels of serum immunoglobulin G (IgG) and IgA in the small intestinal fluid and Peyer's patches and enhanced Peyer's patch-mediated bone marrow cell proliferation activity and cytokine production (IL-2, IL-6, and IFN-γ). Histomorphometric analyses showed an increase in immune cells in the spleen and small intestinal tissues of mice administered PLME, supporting the rationale for its immune system activation. PLME mainly contained neutral sugar (969.1 mg/g), comprising primarily of glucose as a monosaccharide unit. The β-glucan content was 88.5 mg/g. Data suggest that PLME effectively promote immune function by stimulating the systemic immune system through the spleen and intestinal immune tissues. PLME can thus be developed as a functional ingredient to enhance immune functions.

Study on the potential of Sanghuangporus sanghuang and its components as COVID-19 spike protein receptor binding domain inhibitors

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has led to the most severe global pandemic, which began in Wuhan, China. Angiotensin-converting enzyme 2 (ACE2) combines with the spike protein of SARS-CoV-2, allowing the virus to cross the membrane and enter the cell. SARS-CoV-2 is modified by the transmembrane protease serine 2 (TMPRSS2) to facilitate access to cells. Accordingly, ACE2 and TMPRSS2 are targets of vital importance for the avoidance of SARS-CoV-2 infection. Sanghuangporus sanghuang (SS) is a traditional Chinese medicine that has been demonstrated to have antitumor, antioxidant, anti-inflammatory, antidiabetic, hepatoprotective, neuroprotective and immunomodulatory properties. In this paper, we demonstrated that SS decreased ACE2 and TMPRSS2 expression in cell lines and a mouse model without cytotoxicity or organ damage. Liver and kidney sections were confirmed to have reduced expression of ACE2 and TMPRSS2 by immunohistochemistry (IHC) assessment. Then, hispidin, DBA, PAC, PAD and CA, phenolic compounds of SS, were also tested and verified to reduce the expression of ACE2 and TMPRSS2. In summary, the results indicate that SS and its phenolic compounds have latent capacity for preventing SARS-CoV-2 infection in the future.

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.

Styrylpyrones from Phellinus linteus Mycelia Alleviate Non-Alcoholic Fatty Liver by Modulating Lipid and Glucose Metabolic Homeostasis in High-Fat and High-Fructose Diet-Fed Mice

Phellinus linteus (PL), an edible and medicinal mushroom containing a diversity of styrylpyrone-type polyphenols, has been shown to have a broad spectrum of bioactivities. In this study, the submerged liquid culture in a 1600-L working volume of fermentor was used for the large-scale production of PL mycelia. Whether PL mycelia extract is effective against nonalcoholic fatty liver disease (NAFLD) is still unclear. In the high fat/high fructose diet (HFD)-induced NAFLD C57BL/6 mice study, the dietary supplementation of ethyl acetate fraction from PL mycelia (PL-EA) for four weeks significantly attenuated an increase in body weight, hepatic lipid accumulation and fasting glucose levels. Mechanistically, PL-EA markedly upregulated the pgc-1α, sirt1 genes and adiponectin, downregulated gck and srebp-1c; upregulated proteins PPARγ, pAMPK, and PGC-1α, and downregulated SREBP-1 and NF-κB in the liver of HFD-fed mice. Furthermore, the major purified compounds of hispidin and hypholomine B in PL-EA significantly reduced the level of oleic and palmitic acids (O/P)-induced lipid accumulation through the inhibition of up-regulated lipogenesis and the energy-metabolism related genes, ampk and pgc-1α, in the HepG2 cells. Consequently, these findings suggest that the application of PL-EA is deserving of further investigation for treating NAFLD.

Sesquiterpenes and polyphenols with glucose-uptake stimulatory and antioxidant activities from the medicinal mushroom Sanghuangporus sanghuang

A chemical investigation on the fermentation products of Sanghuangporus sanghuang led to the isolation and identification of fourteen secondary metabolites (1-14) including eight sesquiterpenoids (1-8) and six polyphenols (9-14). Compounds 1-3 were sesquiterpenes with new structures which were elucidated based on NMR spectroscopy, high resolution mass spectrometry (HRMS) and electronic circular dichroism (ECD) data. All the isolates were tested for their stimulation effects on glucose uptake in insulin-resistant HepG2 cells, and cellular antioxidant activity. Compounds 9-12 were subjected to molecular docking experiment to primarily evaluate their anti-coronavirus (SARS-CoV-2) activity. As a result, compounds 9-12 were found to increase the glucose uptake of insulin-resistant HepG2 cells by 18.1%, 62.7%, 33.7% and 21.4% at the dose of 50 μmol·L^-1, respectively. Compounds 9-12 also showed good cellular antioxidant activities with CAA₅₀ values of 12.23, 23.11, 5.31 and 16.04 μmol·L^-1, respectively. Molecular docking between COVID-19 M^pro and compounds 9-12 indicated potential SARS-CoV-2 inhibitory activity of these four compounds. This work provides new insights for the potential role of the medicinal mushroom S. sanghuang as drugs and functional foods.

Biological activities of two polypore macrofungi (Basidiomycota) and characterization of their compounds using HPLC-DAD and LC-ESI-MS/MS

Members of Hymenochaetaceae fungi are among well-known macromycetes with various medicinal properties. The aim of this study was to investigate the biological activities of Phellinus tuberculosus and Fuscoporia ferruginosa collected in Iran. The antimicrobial, antioxidant, and cytotoxic activities of the two species were examined, and their phenolic and polysaccharide contents were quantified. Compounds were characterized by HPLC-DAD chromatography and LC-ESI-MS/MS spectroscopy. According to our results, the antibacterial and antioxidant effects of P. tuberculosus extracts were stronger than F. ferruginosa. Also, the effect of hydroalcoholic extracts was higher than the aqueous extract. Gram-positive bacteria were more sensitive to all extracts, especially Streptococcus mutans with a MIC of 0.7 mg/mL and MBC of 6.25 mg/mL. HPLC-DAD analyses detected gallic acid, caffeic acid, and syringic acid in both fungi. The LC-ESI-MS/MS confirmed the detected compounds in HPLC-DAD and showed the presence of several phenolic compounds such as phellifuropyranone, phelligridin, and hispidin, besides others. This study showed that F. ferruginosa and P. tuberculosus are potent medicinal fungi with antibacterial and antioxidant properties, with no toxic effect on normal HDF cells, and possess various bioactive compounds including styrylpyrone-type phenols with well-known bioactivities.

Artificial Cultivation Characteristics and Bioactive Effects of Novel Tropicoporus linteus (Syn. Phellinus linteus) Strains HN00K9 and HN6036 in Korea

Phellinus strains were collected from different areas in Korea. Of them, the fast mycelial growing strains were artificially cultivated on the oak logs to produce fruiting body. The varieties, Phellinus linteus ASI26099 (Korea Sanghwang) and P. baumii PBJS (Jangsoo Sanghwang) were grown under the same conditions as controls. Their cultivating characteristics including mycelial colonization, pinhead formation, and fruiting body formation rate were investigated on the logs. Basidiocarps of Phellinus strains HN00K9, HN6036, and ASI26099 were concentrically zonate and shallowly sulcate, and dark chestnut showing typical characteristics of Tropicoporus linteus (synonyum: P. linteus, Inonotus linteus, polyporus linteus), which is distinguishably different to PBJS. HN00K9 showed the highest yield of fruiting body among the mushroom strains. The β-glucan content in fruiting bodies of HN00K9 was 20% higher than those of other strains. Bioactive effects of polysaccharide samples from fruiting bodies of Phellinus strains, HN00K9, HN6036, ASI26099, and PBJS were assessed on cell viability and cytokine (IL-6 and TNF-α) inhibition and finally on anticancer to different human cancer cells.

The phytochemistry and pharmacology of medicinal fungi of the genus Phellinus: a review

Phellinus Quél is one of the largest genera of Hymenochaetaceae, which is comprised of about 220 species. Most Phellinus macro-fungi are perennial lignicolous mushrooms, which are widely distributed on Earth. Some Phellinus fungi are historically recorded as traditional medicines used to treat various diseases in eastern Asian countries, especially China, Japan and Korean. Previous phytochemical studies have revealed that Phellinus fungi produce diverse secondary metabolites, which mainly contain polysaccharides, flavones, coumarins, terpenes, steroids, and styrylpyranones. Pharmacological documents have demonstrated that Phellinus mushrooms and their compounds have a variety of bioactivities, such as anti-tumor, immunomodulation, anti-oxidative and anti-inflammation, anti-diabetes, neuro-protection, and anti-viral effects. This review surveys the literature reporting the isolation, characterization, and bioactivities of secondary metabolites from the fungi of the genus Phellinus, focusing on studies published in the literature up to April 2020. Herein, a total of more than 300 compounds from 13 Phellinus species and their isolation, characterization, chemistry, pharmacological activities, and relevant molecular mechanisms are comprehensively summarized.

Protective Effects of Phellinus linteus Mycelium on the Development of Osteoarthritis after Monosodium Iodoacetate Injection

Objective

The aim of this study was to identify the protective effects of Phellinus linteus mycelium (PLM) and its possible mechanisms in a model of monosodium iodoacetate- (MIA-) induced osteoarthritis (OA).

Methods

Intra-articular injection of MIA was injected to 50 μL with 80 mg/mL using a 0.3 mL insulin syringe into the right knee joint. Changes in hindpaw weight-bearing distribution between the right (osteoarthritic) and left (contralateral control) legs were used as an index of joint discomfort. PLM (50, 100, and 200 mg/kg body weight) was orally administered once daily for 14 days from day 7 after MIA treatment. And then, various factors associated with inflammatory response and cartilage degeneration in cartilage tissues detected by western blotting.

Results

PLM treatment showed a concentration-dependent elevation in change in hindpaw weight-bearing distribution (HWBD). PLM200 demonstrated the capacity to significantly increase HWBD, indicating that the change in weight-bearing distribution means the reduction of spontaneous pain. Our results indicate that PLM suppressed the inflammatory factors via NF-κB signaling pathway induced by p38 phosporlyation. Moreover, PLM200 exhibited a significant reduction of ROS produced by the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. PLM100 and PLM200 inhibited the levels of matrix metalloproteinase (MMP)-1, one of proteinase that degrades extracellular matrix (ECM).

Conclusions

Taken together, our results indicated that PLM has a strong chondroprotective effect through the suppression both ROS production and inflammation.

Vasodilatory Effect of Phellinus linteus Extract in Rat Mesenteric Arteries

Phellinus linteus is a well-known medicinal mushroom that is widely used in Asian countries. In several experimental models, Phellinus linteus extracts were reported to have various biological effects, including anti-inflammatory, anti-cancer, hepatoprotective, anti-diabetic, neuroprotective, and anti-angiogenic activity. In the present study, several bioactive compounds, including palmitic acid ethyl ester and linoleic acid, were identified in Phellinus linteus. The intermediate-conductance calcium-activated potassium channel (IK_Ca) plays an important role in the regulation of the vascular smooth muscle cells’ (VSMCs) contraction and relaxation. The activation of the IK_Ca channel causes the hyperpolarization and relaxation of VSMCs. To examine whether Phellinus linteus extract causes vasodilation in the mesenteric arteries of rats, we measured the isometric tension using a wire myograph. After the arteries were pre-contracted with U46619 (a thromboxane analogue, 1 µM), Phellinus linteus extract was administered. The Phellinus linteus extract induced vasodilation in a dose-dependent manner, which was independent of the endothelium. To further investigate the mechanism, we used the non-selective K⁺ channel blocker tetraethylammonium (TEA). TEA significantly abolished Phellinus linteus extract-induced vasodilation. Thus, we tested three different types of K⁺ channel blockers: iberiotoxin (BK_ca channel blocker), apamin (SK_ca channel blocker), and charybdotoxin (IK_ca channel blocker). Charybdotoxin significantly inhibited Phellinus linteus extract-induced relaxation, while there was no effect from apamin and iberiotoxin. Membrane potential was measured using the voltage-sensitive dye bis-(1,3-dibutylbarbituric acid)-trimethine oxonol (DiBAC₄(3)) in the primary isolated vascular smooth muscle cells (VSMCs). We found that the Phellinus linteus extract induced hyperpolarization of VSMCs, which is associated with a reduced phosphorylation level of 20 KDa myosin light chain (MLC₂₀).

A Review: The Bioactivities and Pharmacological Applications of Phellinus linteus

Phellinus linteus is a popular medicinal mushroom that is widely used in China, Korea, Japan, and other Asian countries. P. linteus comprises various bioactive components, such as polysaccharides, triterpenoids, phenylpropanoids, and furans, and has proven to be an effective therapeutic agent in traditional Chinese medicine for the treatment and the prevention of various diseases. A number of studies have reported that P. linteus possesses many biological activities useful for pharmacological applications, including anticancer, anti-inflammatory, immunomodulatory, antioxidative, and antifungal activities, as well as antidiabetic, hepatoprotective, and neuroprotective effects. This review article briefly presents the recent progress made in understanding the bioactive components, biological activities, pharmacological applications, safety, and prospects of P. linteus, and provides helpful references and promising directions for further studies of P. linteus.