Species identity of Phellinus linteus (sanghuang) extensively used as a medicinal mushroom in Korea

In vitro and in vivo inhibitory effects of the Sanghuang mushroom extracts against Candida albicans

Aim: To explore the antifungal potential of Sanghuang mushroom, a traditional Chinese medicine. Materials & methods: The antifungal properties and the potential mechanism of Sanghuang mushroom extracts against Candida albicans were studied in vitro and in vivo. Results: Sanghuang mushroom extracts inhibited the biofilm formation, increased the cell membrane permeability and promoted cell apoptosis of C. albicans in vitro. In a murine model of vulvovaginal candidiasis, Sanghuang mushroom extracts reduced the vaginal fungal load, improved inflammatory cell infiltration and downregulated the expression of TNF-α, IL-1β and IL-6. Untargeted metabolomic analysis suggested the presence of ten antifungal components in Sanghuang mushroom extracts. Conclusion: Sanghuang mushroom extracts showed promise as antifungal agent against candidiasis, with potential therapeutic implications.

Comparative genomic analysis of Sanghuangporus sanghuang with other Hymenochaetaceae species

Sanghuangporus sanghuang is a medicinal macrofungus with antioxidant and antitumor activities, and it is enriched with secondary metabolites such as polysaccharides, terpenes, polyphenols, and styrylpyrone compounds. To explore the putative core genes and gene clusters involved in sanghuang biosynthesis, we sequenced and assembled a 40.5-Mb genome of S. sanghuang (SH1 strain). Using antiSMASH, local BLAST, and NCBI comparison, 12 terpene synthases (TPSs), 1 non-ribosomal peptide synthase, and five polyketide synthases (PKSs) were identified in SH1. Combining the transcriptome analysis with liquid chromatography mass spectrometry-ion trap-time of flight analysis, we determined that ShPKS1, one phenylalanine aminolyase (ShPAL), and one P450 monooxygenase (ShC4H1) were associated with hispidin biosynthesis. Structural domain comparison indicated that ShPKS2 and ShPKS3 are involved in the biosynthesis of orsellinic acid and 2-hydroxy-6-methylbenzoic acid, respectively. Furthermore, comparative genomic analysis of SH1 with 14 other fungi from the Hymenochaetaceae family showed variation in the number of TPSs among different genomes, with Coniferiporia weirii exhibiting only 9 TPSs and Inonotus obliquus having 20. The number of TPSs also differed among the genomes of three strains of S. sanghuang, namely Kangneng (16), MS2 (9), and SH1 (12). The type and number of PKSs also varied among species and even strains, ranging from two PKSs in Pyrrhoderma noxium to five PKSs in S. sanghuang SH1. Among the three strains of S. sanghuang, both the structural domains and the number of PKSs in strains MS2 and SH1 were consistent, whereas strain Kangneng exhibited only four PKSs and lacked the PKS with the structural domain KS-AT-DH-KR-ACP. Additionally, Sanghuangporus species exhibited more similar PKSs to Inonotus, with higher gene similarity around five PKSs, while showing differences from those of other fungi in the same family, including Phellinus lamaoensis. This result supports the independent taxonomic significance of the genus Sanghuangporus to some extent.

The mechanism of polysaccharide synthesis of Sanghuangporus sanghuang based on multi-omic analyses and feedback inhibition

S. sanghuang polysaccharide has various biological roles in promoting human health, however, the underlying mechanism of polysaccharide synthesis in S. sanghuang remain elusive. In the present study, the molecular structure of novel polysaccharide in the mutant S. sanghuang strain A130 with high yield of polysaccharide was characterized. The critical genes/proteins and pathways involved in polysaccharide synthesis were investigated via comparative transcriptomic, proteomic, and integrative analysis between wildtype strain SH-1 and A130. An integrated analysis of transcriptomic and proteomic results was also performed to locate potential regulators in the production of polysaccharides. The genes of cellobiohydrolase1 (CBH1) and MutS Homolog 6 (MSH6) related to glycolysis/gluconeogenesis were differentially expressed between A130 and SH-1, suggesting the potential involvement of these genes in regulating the production of polysaccharide. Proteomic analysis revealed that the abundance of Tyrosinase (TYR) and Trehalase (TREH) were substantially different between A130 and SH-1. The potential involvement of TYR in polysaccharide production was confirmed by transcriptomic-proteomic integrated analysis. The biological role of TYR and TREH in polysaccharide production was further verified by feedback inhibition of kojic acid and validamycin A, respectively. Overall, our study provides critical insights for the polysaccharide synthesis and high yield of polysaccharide through genes/pathways regulating in S. sanghuang.

Sanghuangporus sanghuang extract extended the lifespan and healthspan of Caenorhabditis elegans via DAF-16/SIR-2.1

Sanghuangporus Sanghuang is a fungus species. As a traditional Chinese medicine, it is known for antitumor, antioxidant and anti-inflammatory properties. However, the antiaging effect of S. Sanghuang has not been deeply studied. In this study, the effects of S. Sanghuang extract (SSE) supernatants on the changes of nematode indicators were investigated. The results showed that different concentrations of SSE prolonged the lifespans of nematodes and substantially increased these by 26.41%. In addition, accumulations of lipofuscin were also visibly reduced. The treatment using SSE also played a role in increasing stress resistance, decreasing ROS accumulations and obesity, and enhancing the physique. RT-PCR analysis showed that the SSE treatment upregulated the transcription of daf-16, sir-2.1, daf-2, sod-3 and hsp-16.2, increased the expression of these genes in the insulin/IGF-1 signalling pathway and prolonged the lifespans of nematodes. This study reveals the new role of S. Sanghuang in promoting longevity and inhibiting stress and provides a theoretical basis for the application of S. Sanghuang in anti-ageing treatments.

Hispolon alleviates oxidative damage by stimulating the Nrf2 signaling pathway in PC12 cells

Natural products derived from the daily diet are garnering increasing attention for neurodegenerative disease (ND) treatment. Hispolon (His), a small molecule from Phellinus linteus, has been reported to have various pharmacological activities. Here, we evaluated its protective effect on a neuron-like rat pheochromocytoma cell line (PC12). Results showed that His could restore cell death induced by oxidative damage. Nuclear factor-erythroid 2 (NF-E2)-related factor 2 (Nrf2) plays a significant role in maintaining cellular redox homeostasis. After treatment with His, some Nrf2-governed antioxidant genes were upregulated in a dose-dependent manner. However, the protective effect of His on PC12 cells was easily terminated by Nrf2 knockdown, demonstrating that Nrf2 is a critical component in this cytoprotective process. Taken together, our study showed that His was not only an effective activator of Nrf2 but also a promising candidate for ND treatment.

Pilot Study: Nutritional and Preclinical Safety Investigation of Fermented Hispidin-Enriched Sanghuangporus sanghuang Mycelia: A Promising Functional Food Material to Improve Sleep

Sleep disturbances have been the hallmark of the recent coronavirus disease 2019 pandemic. Studies have shown that once sleep is disrupted, it can lead to psychological and physical health issues which can, in turn, disrupt circadian rhythm and induce further sleep disruption. As consumers are trying to establish healthy routines, nutritional and preclinical safety investigation of fermented hispidin-enriched Sanghuangporus sanghuang mycelia (GKSS) as a novel food material for spontaneous sleep in Sprague-Dawley rats is conducted for the first time. Results showed that the nutritional analysis of GKSS including moisture, ash, crude lipid, crude protein, carbohydrate, and energy were found to be 2.4 ± 0.3%, 8.0 ± 2.5%, 1.7 ± 0.3%, 22.9 ± 1.2%, 65.1 ± 3.1%, and 367.1 ± 10.2 kcal/100 g respectively. In the 28-day repeated-dose oral toxicity study, only Sprague-Dawley male rats receiving 5 g/kg showed a slight decrease in feed consumption at week 3, but no associated clinical signs of toxicity or significant weight loss were observed. Although a significant reduction of the platelet count was found in mid- and high-dose GKSS treated male groups, such changes were noted to be within the normal range and were not correlated with relative spleen weight changes. Hence, the no observed adverse effect level (NOAEL) of GKSS was identified to be higher than 5 g/kg in rats. After the safety of GKSS is confirmed, the sleep-promoting effect of GKSS ethanolic extract enriched with hispidin was further assessed. Despite 75 mg/kg of GKSS ethanolic extract does not affect wakefulness, rapid eye movement (REM) sleep and non-REM (NREM) sleep, GKSS ethanolic extract at 150 mg/kg significantly decreased wakefulness and enhanced NREM and REM sleep. Interestingly, such effects seem to be mediated through anti-inflammatory activities via NF-E2-related factor-2 (Nrf2) signaling pathway. Taken together, these findings provide the preliminary evidence to studies support the claims suggesting that GKSS contained useful phytochemical hispidin could be considered as and is safe to use as a functional food agent or nutraceutical for relieving sleep problems mediated by Nrf2 pathway, which the results are useful for future clinical pilot study.

A rapid analysis of antioxidants in Sanghuangporus baumii by online extraction-HPLC-ABTS

In the present study, a simple and efficient approach based on the online extraction-high performance liquid chromatography coupled with ABTS antioxidant assay (OLE-HPLC-ABTS) was established to quickly and directly analyze the antioxidants in S. baumii. Through this system, the HPLC mobile phase via a guard column packed with a S. baumii sample was used for online extraction (OLE). The separation was performed on an Agilent Poroshell EC-C18 column with a gradient elution using 0.1% formic acid (A) and 0.1% formic acid-acetonitrile (B) as mobile phase systems and detected at a wavelength of 254 nm. Then, the separated compounds were reacted with the antioxidant solution (ABTS), and the response was recorded at a wavelength of 400 nm. The developed analytical method was successfully applied to S. baumii samples, and eight antioxidants were identified. The established system integrated the online extraction, separation and online antioxidant detection, which is rapid, efficient, and suitable for the rapid screening of antioxidant compounds from solid sample mixtures.

Addressing widespread misidentifications of traditional medicinal mushrooms in Sanghuangporus (Basidiomycota) through ITS barcoding and designation of reference sequences

"Sanghuang" refers to a group of important traditionally-used medicinal mushrooms belonging to the genus Sanghuangporus. In practice, species of Sanghuangporus referred to in medicinal studies and industry are now differentiated mainly by a BLAST search of GenBank with the ITS barcoding region as a query. However, inappropriately labeled ITS sequences of "Sanghuang" in GenBank restrict accurate species identification and, to some extent, the utilization of these species as medicinal resources. We examined all available 271 ITS sequences related to "Sanghuang" in GenBank including 31 newly submitted sequences from this study. Of these sequences, more than half were mislabeled so we have now corrected the corresponding species names. The mislabeled sequences mainly came from strains utilized by non-taxonomists. Based on the analyses of ITS sequences submitted by taxonomists as well as morphological characters, we separate the newly described Sanghuangporus subbaumii from S. baumii and treat S. toxicodendri as a later synonym of S. quercicola. Fourteen species of Sanghuangporus are accepted, with intraspecific distances up to 1.30% (except in S. vaninii, S. weirianus and S. zonatus) and interspecific distances above 1.30% (except between S. alpinus and S. lonicerinus, and S. baumii and S. subbaumii). To stabilize the concept of these 14 species of Sanghuangporus, their taxonomic information and reliable ITS reference sequences are provided. Moreover, ten potential diagnostic sequences are provided for Hyperbranched Rolling Circle Amplification to rapidly confirm three common commercial species, viz. S. baumii, S. sanghuang, and S. vaninii. Our results provide a practical method for ITS barcoding-based species identification of Sanghuangporus and will promote medicinal studies and commercial development from taxonomically correct material.

Mushroom Inonotus sanghuang alleviates experimental pulmonary fibrosis: Implications for therapy of pulmonary fibrosis

Mushroom Inonotus sanghuang has been characterized as a traditional medicine in China and has pharmacological activities to treat inflammation, gastroenteric dysfunction, and cancer. Recently, we reported the impact of Inonotus sanghuang extract (ISE) from ethyl acetate fraction on bleomycin (BLM)-induced acute lung injury in mice. Here, we aimed to investigate ISE's impact on pulmonary fibrosis using in vivo and in vitro models and the underlying mechanisms. To evaluate pulmonary fibrosis, female C57BL/6 mice fed ISE (0% or 0.6% in diet) for 4 weeks were instilled intratracheally with BLM and then continued the same diet before the end of the experiment. A549 cells were used to evaluate the epithelial-mesenchymal transition (EMT). Feeding ISE improved BLM-treated mice's survival via decreasing lung infiltrating cells and fibrosis, followed by reducing hydroxyproline content, collagen deposition, and mesenchymal markers (α-SMA and vimentin) while increasing epithelial marker E-cadherin. ISE also suppressed the TGF-β expression, Smad2/3 phosphorylation, and EMT-related transcription factor Snail upon BLM instillation. Iin vitro study demonstrated that ISE inhibited TGF-β-induced EMT-like phenotype and cell behaviors, the expression of α-SMA and vimentin, and prevented E-cadherin reduction of A549 cells. Consistent with in vivo study, ISE abrogated p-Smad2/3, and Snail expression. Finally, the influence of ISE on EMT was not due to ISE toxicity. Our findings indicated that ISE effectively attenuated BLM-induced lung fibrosis. These ISE properties were thought to be involved in interfering TGF-β, Smad2/3 phosphorylation, and EMT process, suggesting that the material has the potential health benefits to improve lung fibrosis.

Optimized production and safety evaluation of hispidin-enriched Sanghuangporus sanghuang mycelia

Phellinus linteus, also known as the sanghuang mushroom, is a medicinal mushroom that has been recognized as beneficial to health for more thousands of years. Among its diverse valuable secondary metabolites, the yellow-brown styrylpyrone pigment hispidin has garnered significant attention due to its various pharmacological effects. However, recently after detailed morphological and molecular phylogenetic studies, the correct scientific name of the true sanghuang strains was shown not to be P. linteus but Sanghuangporus sanghuang. As the incorrect binomial name P. linteus has long been misleadingly referred, there is a need to evaluate the safety of S. sanghuang. Moreover, the growing conditions can impact the secondary metabolite profile of the fungi. Hence, this study is the first to optimize hispidin production and to investigate the genotoxic and oral toxic effects of hispidin-enriched S. sanghuang mycelia. In order to induce the biosynthesis of hispidin, 15 different culture media consisting of five carbon sources, five nitrogen sources, and five initial pH conditions were screened. Glucose and yeast extract at an initial pH of 5 were found to be the most suitable carbon and nitrogen sources, respectively, for the optimal growth and production of hispidin. Moreover, the production of hispidin was 3 mg/g in a 20-ton bioreactor under optimal conditions. Furthermore, the ames test, in vitro chromosome aberration test, acute oral toxicity test, and bone marrow micronucleus test were used to detect toxicological properties of 3 mg/g hispidin-enriched S. sanghuang mycelia. In all tests, there was no statistically significant difference between the mycelia and the negative control. Based on the results obtained, the present study demonstrates that 3 mg/g hispidin-enriched S. sanghuang mycelia has a very low order of toxicity, which supports its safety for human consumption.

The Genome of the Medicinal Macrofungus Sanghuang Provides Insights Into the Synthesis of Diverse Secondary Metabolites

The mushroom, Sanghuang is widely used in Asian countries. This medicinal fungus produces diverse bioactive compounds and possesses a potent ability to degrade the wood of the mulberry tree. However, the genes, pathways, and mechanisms that are involved in the biosynthesis of the active compounds and wood degradation by Sanghuang mushroom are still unknown. Here, we report a 34.5 Mb genome—encoding 11,310 predicted genes—of this mushroom. About 16.88% (1909) of the predicted genes have been successfully classified as EuKaryotic Orthologous Groups, and approximately 27.23% (665) of these genes are involved in metabolism. Additionally, a total of 334 genes encoding CAZymes—and their characteristics—were compared with those of the other fungi. Homologous genes involved in triterpenoid, polysaccharide, and flavonoid biosynthesis were identified, and their expression was examined during four developmental stages, 10 and 20 days old mycelia, 1 year old and 3 years old fruiting bodies. Importantly, the lack of chalcone isomerase 1 in the flavonoid biosynthesis pathway suggested that different mechanisms were used in this mushroom to synthesize flavonoids than those used in plants. In addition, 343 transporters and 4 velvet family proteins, involved in regulation, uptake, and redistribution of secondary metabolites, were identified. Genomic analysis of this fungus provides insights into its diverse secondary metabolites, which would be beneficial for the investigation of the medical applications of these pharmacological compounds in the future.

Phellinus baumii enhances the immune response in cyclophosphamide-induced immunosuppressed mice

Phellinus species is a mushroom used as traditional medicine in Eastern Asia. Research on Phellinus baumii (PB) is relatively limited; however, it has been reported to have antioxidant, DNA damage-protecting, immunostimulating, and antidiabetic activities. In our previous study on anti-inflammatory properties in lipopolysaccharide-stimulated RAW 264.7 cells and the various bioactive components of PB, we propose that PB could exert immune enhancing effects. Therefore, our current study aimed to investigate the immune-enhancing effect on immunosuppressed mice. Different concentrations of PB extract (0, 50, 100, 200, and 400 mg/kg body weight) were given to mice via oral gavage for 6 weeks accompanied by intraperitoneal cyclophosphamide administration to induce immunosuppression. A bone marrow micronucleus test was performed in mice to screen for potential genotoxic compounds. Splenocyte viability and proliferation, splenic and peritoneal natural killer cell activities, and hematological markers were then measured. Cytokines in the spleen and serum, as well as splenic mRNA levels of nuclear factor-κB; interferon-γ; tumor necrosis factor-α; and interleukin (IL)-1β, IL-6, and IL-12, were determined in mice. As a result, PB ameliorated T- and B-lymphocyte proliferation, splenic and peritoneal NK cell activities, bone marrow cells, hematological markers, cytokine levels, and T-lymphocyte numbers. Moreover, serum and spleen cytokine levels and mRNA expression were elevated in the PB groups compared to controls. Our results suggest that the PB extract can be used as a potent immunomodulator under immunosuppressive conditions. Thus, PB may be used as a potent biofunctional and pharmaceutical material to potentially enhance human immunity.

The Antitumor Potential of Extract of the Oak Bracket Medicinal Mushroom Inonotus baumii in SMMC-7721 Tumor Cells

Inonotus baumii, a traditional medicinal mushroom, has been historically used in China and other countries of East Asia for the treatment of various diseases. The aim of this study is to investigate the antitumor activity of the extract of I. baumii (EIB) against hepatocellular carcinoma and the possible mechanism involved. The MTT assay was used to evaluate the proliferative activity of SMMC-7721 cells treated with EIB. Hoechst 33258 and JC-1 staining were used to determine nuclear morphological changes and mitochondrial membrane potential, respectively. Flow cytometry analysis indicated that EIB blocked the cell cycle at the S phase and induced significant apoptosis. EIB increased the protein expression of Bax, cytochrome c, cleaved caspase-3, and decreased Bcl-2 in SMMC-7721. Moreover, EIB induced autophagy, indicated by the increase of autophagy-related protein expression of LC3-II and decrease of p62, and the AMPK/mTOR/ULK1 pathway was involved in the autophagic cell death. In vivo, EIB was found to strongly inhibit the growth of tumors in BALB/c nude mice. Our results indicated that I. baumii might be a potential natural therapeutic agent for liver cancer, as it could induce apoptosis and autophagy in HCC cells.

Species Diversity, Phylogeny, Divergence Time, and Biogeography of the Genus Sanghuangporus (Basidiomycota)

"Sanghuang" is a popular fungus used as a Chinese traditional medicine. In fact, it represents a group of fungi belonging to the genus Sanghuangporus, but little is known about its origin and biogeography. The aim of this study was to characterize the molecular relationships, origin and biogeographical distribution of Sanghuangporus. The multi-locus phylogenetic analyses were used to infer the phylogenetic relationships. In addition, based on Bayesian evolutionary analysis using sequences from the internal transcribed spacer (ITS), nuclear large subunit rDNA (nLSU), translation elongation factor 1-α (EF1-α), and the largest and second largest subunits of RNA polymerase II (RPB1 and RPB2), we used a fungus fossil-based approach to gain insight into the divergence time of species in Sanghuangporus. The molecular phylogeny strongly supports the monophyly of Sanghuangporus (MP = 100%, ML = 100%, and BPP = 1.00), and 13 species are recognized in this genus. The Bayesian uncorrelated lognormal relaxed molecular clock using BEAST and reconstructed ancestral areas indicate that the maximum crown age of Sanghuangporus is approximately 30.85 million years. East Asia is the likely ancestral area (38%). Dispersal and differentiation to other continents then occurred during the late Middle Miocene and Pliocene. The ancestor of Sanghuangporus probably originated in palaeotropical Northeast Asia and covered Northeast Asia and East Africa during the Oligocene-Miocene, hosted by plants that expanded via the "Gomphotherium Landbridge." Six kinds of dispersal routes are proposed, including intercontinental dispersal events of three clades between Northeast Asia and East Africa, between East Asia and North America, and between Northeast Asia and Europe.

Inonotus sanghuang Polyphenols Attenuate Inflammatory Response Via Modulating the Crosstalk Between Macrophages and Adipocytes

Aims: Obesity is characterized as a chronic state of low-grade inflammation with progressive immune cell infiltration into adipose tissue. Adipose tissue macrophages play a critical role in the establishment of chronic inflammatory states and metabolic dysfunctions. Inonotus (I.) sanghuang and its extract polyphenols exhibit anti-carcinogenesis, anti-inflammatory, and anti-oxidant activities. However, the action of I. sanghuang polyphenols in obesity-related inflammation has not been reported. The aim of this study was to explore the anti-inflammatory action of polyphenols from I. sanghuang extract (ISE) in macrophages and the interaction between macrophages and adipocytes.

Materials and Methods: RAW264.7 macrophages were stimulated with LPS or conditioned medium of hypertrophied 3T3-L1 adipocytes or cocultured with differentiated adipocytes in the presence of different doses of ISE. The inflammatory cytokines were evaluated by ELISA, the MAPK, NF-κB, and IL-6/STAT3 signals were determined by immunoblotting, and the migrated function of macrophages was determined by migration assay.

Results: ISE suppressed the inflammatory mediators including NO, TNF-α, IL-6, and MCP-1 induced by either LPS or conditioned medium derived from 3T3-L1 adipocytes. ISE also decreased the production of these inflammatory mediators in cocultures of 3T3-L1 adipocytes and RAW264.7 macrophages. Furthermore, ISE blocked RAW264.7 macrophages migration toward 3T3-L1 adipocytes in cocultures. Finally, this effect of ISE might be mediated via inhibiting ERK, p38, and STAT3 activation.

Conclusions: Our findings indicate the possibility that ISE suppresses the interaction between macrophages and adipocytes, attenuates chronic inflammation in adipose tissue and improves obesity-related insulin resistance and complication, suggesting that ISE might be a valuable medicinal food effective in improving insulin resistance and metabolic syndrome.

Evaluation of antioxidant, anti-inflammatory and anti-proliferative activities of ethanol extracts from different varieties of Sanghuang species

Sanghuangporus sanghuang is a rare fungal species that grows on wild mulberry trees, and its yield is much lower than that of valuable medicinal herbs.