Antibacterial effect of Phellinus linteus against methicillin-resistant Staphylococcus aureus

Comparison of antioxidant and antimicrobial activities of submerged culture mycelium and basidioma extracts of Tropicoporus linteus

This research aimed to assess the biological characteristics of both submerged culture mycelium and artificial basidioma of Tropicoporus linteus NTH-PL4. The extraction yield from the basidioma surpassed that of the mycelium. The use of hot water extract resulted in the highest total carbohydrate content, predominantly found in the basidioma. Conversely, the 75% methanol extract exhibited higher levels of total phenolics and total flavonoids, predominantly in the mycelium. Tests on antioxidant capacity indicated that 75% methanol yielded the best results among the tested solvents, with the basidioma extract displaying superior DPPH scavenging, ferrous ion chelation, and reduction power compared to the mycelium extract. Moreover, ethyl acetate emerged as an effective solvent, yielding a stronger extract from the basidioma. Compound analysis revealed higher concentrations of gallic acid, salicylic acid, caffeic acid, and ellagic acid in the mycelium for the solvents used, while hispidin and beta-glucan exhibited an opposite trend.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01612-1.

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.

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.

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.

Traditional uses, fermentation, phytochemistry and pharmacology of Phellinus linteus: A review

Medicinal mushroom Phellinus linteus ("Sanghuang" in Chinese, ) is a famous fungus which is widely used in China, Korea, and other Asian countries. As a traditional Chinese medicine with a 2000-year long history, medicinal applications of Phellinus linteus mainly include treating hemorrhage, hemostasis and diseases related to female menstruation according to Chinese clinical empirical practice. A number of studies reported Phellinus linteus possessed good therapeutic effects on various ailments including tumor, diabetes, inflammation, obesity, etc. The present paper comprehensively reviewed the traditional uses, fermentation, constituent and pharmacology of Phellinus linteus based on scientific literature as well as critical analysis of the research. This review aimed to provide latest information and new foundations and directions for further investigations on Phellinus linteus. All available information about Phellinus linteus was supplied by library database and electronic search (CNKI, Google Scholar, ScienceDirect, Web of Science, PubMed, etc.). Some local and ancient books as well as brilliant scholars were also important information resources. Improvement of fermentation techniques promoted the production of Phellinus linteus. Studies of constituents showed the main chemical composition of Phellinus linteus included polysaccharides, flavones, triterpenes, aromatic acids, amino acids, etc. and polysaccharides were found to account for the largest proportion. Pharmacological researches revealed Phellinus linteus possessed a variety of biological activities including anti-cancer, immuno-regulation, anti-diabetes, anti-oxidation and anti-inflammation. Based on these summarized information, this review was presented to provide helpful references and beneficial directions for future studies of Phellinus linteus.

Phellinus igniarius: A Pharmacologically Active Polypore Mushroom

Mushrooms have been widely used in traditional medicine for the treatment of various diseases. Today, their therapeutic value is scientifically studied and appreciated. Research indicates that polypores - a large group of fungi of the phylum Basdiomycota - exhibit antiviral, antimicrobial, anticancer, anti-allergic, anti-atherogenic, hypoglycemic, hepatoprotective and anti-inflammatory activities. Phellinus igniarius, a polypore mushroom, is one of the most used in traditional Asian medicine. Its potent anticancer activity has been repeatedly reported. In the past two decades, numerous pharmacologically active metabolites have been isolated and identified from P. igniarius. Among the large number of compounds, the most active group are polysaccharides. They modulate immune responses and inhibit tumor growth.

Synergistic Anti-bacterial Effects of Phellinus baumii Ethyl Acetate Extracts and β-Lactam Antimicrobial Agents Against Methicillin-Resistant Staphylococcus aureus

BACKGROUND

The development of new drugs or alternative therapies effective against methicillin-resistant Staphylococcus aureus (MRSA) is of great importance, and various natural anti-MRSA products are good candidates for combination therapies. We evaluated the antibacterial activities of a Phellinus baumii ethyl acetate extract (PBEAE) and its synergistic effects with β-lactams against MRSA.

METHODS

The broth microdilution method was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the PBEAE. The PBEAE synergistic effects were determined by evaluating the MICs of anti-staphylococcal antibiotic mixtures, with or without PBEAE. Anti-MRSA synergistic bactericidal effects of the PBEAE and β-lactams were assessed by time-killing assay. An ELISA was used to determine the effect of the PBEAE on penicillin binding protein (PBP)2a production.

RESULTS

The MICs and MBCs of PBEAE against MRSA were 256-512 and 1,024-2,048 μg/mL, respectively. The PBEAE significantly reduced MICs of all β-lactams tested, including oxacillin, cefazolin, cefepime, and penicillin. However, the PBEAE had little or no effect on the activity of non-β-lactams. Time-killing assays showed that the synergistic effects of two β-lactams (oxacillin and cefazolin) with the PBEAE were bactericidal in nature (Δlog10 colony forming unit/mL at 24 hr: 2.34-2.87 and 2.10-3.04, respectively). The PBEAE induced a dose-dependent decrease in PBP2a production by MRSA, suggesting that the inhibition of PBP2a production was a major synergistic mechanism between the β-lactams and the PBEAE.

CONCLUSIONS

PBEAE can enhance the efficacy of β-lactams for combined therapy in patients infected with MRSA.

Styrylpyrone-class compounds from medicinal fungi Phellinus and Inonotus spp., and their medicinal importance

Members of the genera Phellinus and Inonotus, including P. linteus, P. igniarius, P. ribis, I. obliquus and I. xeranticus are well-known medicinal fungi (mushrooms) and have been used in treatment of cancer, diabetes, bacterial and viral infections and ulcer. Adverse effects of these medicinal mushrooms have not yet been reported, indicating the safe nature of these mushrooms. Polysaccharides, particularly β-glucan, are considered the compounds responsible for the biological activity of medicinal mushrooms. However, there is only a limited amount of evidence to indicate that polysaccharides are in fact responsible for the biological effects of these medicinal mushrooms. Recently, many research groups have begun identification of active low-MW compounds in medicinal mushrooms, with a focus on the yellow polyphenol pigments, which are composed of a styrylpyrone class of compounds. Interestingly, a representative group of medicinal fungi, including P. linteus, P. igniarius, P. ribis, I. obliquus and I. xeranticus were shown to produce a large and diverse range of styrylpyrone-type polyphenol pigments that exhibited various biological activities, including anti-oxidative, anti-inflammatory, cytotoxic, anti-platelet aggregation, anti-diabetic, anti-dementia and anti-viral effects. Styrylpyrone pigments in mushrooms are thought to have a role similar to that of flavonoids in plants. The unique and unprecedented carbon skeleton of fused styrylpyrone might be an attractive molecular scaffold for pharmacological applications. In this review, the structural diversity, biological effects and biogenesis of styrylpyrone-class polyphenols from medicinal fungi are described.

Hepatoprotective Effects of Polysaccharides Isolated from Phellinus gilvus Against Carbon Tetrachloride-induced Liver Injury in Rats

Phellinus gilvus (PG) is a widely used mushroom for health promotion. We studied the hepatoprotective effect of the polysaccharide aqueous extract of PG (PGP) against carbon tetrachloride (CCl₄)-induced liver injury in rats. Sprague Dawley rats were divided into 5 groups: Normal control, CCl₄ control, PGP 50, 100, and 200 mg/kg + CCl₄. The levels of serum biochemical parameters, liver lipid peroxide and antioxidant enzymes, and histological appearances were evaluated. The CCl₄-induced increments of alanine aminotransferase, asparate aminotransferase, and alkaline phosphatase levels in serum were significantly decreased by PGP-pretreatments. The PGP dose-dependently decreased hepatic malondialdehyde formations in CCl₄-treatment groups. Hepatic antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) were elevated by PGP in CCl₄-treatment groups. Histopathological evaluation of liver showed that the loss of hepatocytes, fatty changes, swelling and extensive necrosis of hepatocytes in centrilobular regions of the CCl₄-treated rats were ameliorated by PGP pretreatment. The PGP has hepatoprotective and antioxidative effects in CCl₄-induced liver injury of rat.

Hispolon induces apoptosis in human gastric cancer cells through a ROS-mediated mitochondrial pathway

Severe side effects and complications such as gastrointestinal and hematological toxicities because of current anticancer drugs are major problems in the clinical management of gastric cancer, which highlights the urgent need for novel effective and less toxic therapeutic approaches. Hispolon, an active polyphenol compound, is known to possess potent antineoplastic and antiviral properties. In this study, we investigated the efficacy of hispolon in human gastric cancer cells and explored the cell death mechanism. Hispolon induced ROS-mediated apoptosis in gastric cancer cells and was more toxic toward gastric cancer cells than toward normal gastric cells, suggesting greater susceptibility of the malignant cells. The mechanism of hispolon-induced apoptosis was that hispolon abrogated the glutathione antioxidant system and caused massive ROS accumulation in gastric cancer cells. Excessive ROS caused oxidative damage to the mitochondrial membranes and impaired the membrane integrity, leading to cytochrome c release, caspase activation, and apoptosis. Furthermore, hispolon potentiated the cytotoxicity of chemotherapeutic agents used in the clinical management of gastric cancer. These results suggest that hispolon could be useful for the treatment of gastric cancer either as a single agent or in combination with other anticancer agents.

Continentalic acid fromAralia continentalis shows activity against methicillin-resistantStaphylococcus aureus

In a continuing search for compounds with antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), a chloroform extract of roots of Aralia continentalis was found to contain continentalic acid (CA, C(20)H(30)O(2)), a diterpenic acid. This compound exhibited potent activity against standard methicillin-susceptible Staphylococcus aureus (MSSA) as well as clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). It was determined that continentalic acid had minimum inhibitory concentrations (MICs) of approximately 8-16 microg/mL against S. aureus, including the MSSA and MRSA standard strains. Therefore, the results obtained in this study suggest that continentalic acid might have potential as an adjunct in the treatment of antibiotic-resistant bacteria.