Yun-Fei Ko

Ganoderma lucidum reduces obesity in mice by modulating the composition of the gut microbiota

Obesity is associated with low-grade chronic inflammation and intestinal dysbiosis. Ganoderma lucidum is a medicinal mushroom used in traditional Chinese medicine with putative anti-diabetic effects. Here, we show that a water extract of Ganoderma lucidum mycelium (WEGL) reduces body weight, inflammation and insulin resistance in mice fed a high-fat diet (HFD). Our data indicate that WEGL not only reverses HFD-induced gut dysbiosis—as indicated by the decreased Firmicutes-to-Bacteroidetes ratios and endotoxin-bearing Proteobacteria levels—but also maintains intestinal barrier integrity and reduces metabolic endotoxemia. The anti-obesity and microbiota-modulating effects are transmissible via horizontal faeces transfer from WEGL-treated mice to HFD-fed mice. We further show that high molecular weight polysaccharides (>300 kDa) isolated from the WEGL extract produce similar anti-obesity and microbiota-modulating effects. Our results indicate that G. lucidum and its high molecular weight polysaccharides may be used as prebiotic agents to prevent gut dysbiosis and obesity-related metabolic disorders in obese individuals.

Anti-obesogenic and antidiabetic effects of plants and mushrooms

Obesity is reaching global epidemic proportions as a result of factors such as high-calorie diets and lack of physical exercise. Obesity is now considered to be a medical condition, which not only contributes to the risk of developing type 2 diabetes mellitus, cardiovascular disease and cancer, but also negatively affects longevity and quality of life. To combat this epidemic, anti-obesogenic approaches are required that are safe, widely available and inexpensive. Several plants and mushrooms that are consumed in traditional Chinese medicine or as nutraceuticals contain antioxidants, fibre and other phytochemicals, and have anti-obesogenic and antidiabetic effects through the modulation of diverse cellular and physiological pathways. These effects include appetite reduction, modulation of lipid absorption and metabolism, enhancement of insulin sensitivity, thermogenesis and changes in the gut microbiota. In this Review, we describe the molecular mechanisms that underlie the anti-obesogenic and antidiabetic effects of these plants and mushrooms, and propose that combining these food items with existing anti-obesogenic approaches might help to reduce obesity and its complications.

The Anti-Tumorigenic Mushroom Agaricus blazei Murill Enhances IL-1β Production and Activates the NLRP3 Inflammasome in Human Macrophages

Agaricus blazei Murill (AbM) has been reported to possess immune activity against tumors and infections through stimulation of mononuclear phagocytes. Recently, AbM extract was shown to induce the production of the pro-inflammatory cytokine, interleukin-1β (IL-1β), in human monocytes. IL-1β is a key pro-inflammatory cytokine produced by activated macrophages and monocytes and its secretion is strictly controlled by the inflammasome. The purpose of this study is to investigate the effect of AbM water extracts on the regulation of IL-1β production and activation of the NLRP3 inflammasome in human THP-1 macrophages. The NLRP3 inflammasome consists of an NLRP3 receptor, an adaptor protein called ASC, and the inflammatory protease, caspase-1. Typically, stimulation of immune cells with microbial products results in production of pro-IL-1β, but a second stress-related signal activates the inflammasome and caspase-1, leading to processing and secretion of IL-1β. Our results show that AbM enhances transcription of IL-1β and triggers NLRP3 inflammasome-mediated IL-1β secretion in human THP-1 macrophages. AbM-mediated IL-1β secretion was markedly reduced in macrophages deficient in NLRP3 and ASC, demonstrating that the NLRP3 inflammasome is essential for AbM-induced IL-1β secretion. In addition, caspase-1 was activated and involved in proteolytic cleavage and secretion of IL-1β in AbM-treated macrophages. AbM-mediated IL-1β secretion also decreased in cells treated with cathepsin B inhibitor, suggesting that AbM can induce the release of cathepsin B. Furthermore, our data show that AbM-induced inflammasome activation requires the release of ATP, binding of extracellular ATP to the purinergic receptor P2X7, the generation of reactive oxygen species, and efflux of potassium. Taken together, these findings reveal that AbM activates the NLRP3 inflammasome via multiple mechanisms, resulting in the secretion of IL-1β.

cis-Resveratrol produces anti-inflammatory effects by inhibiting canonical and non-canonical inflammasomes in macrophages

Resveratrol, a natural phenolic compound found in red grapes and wine, exists as cis and trans isomers. Recent studies have shown that trans-resveratrol possesses anti-inflammatory, anti-oxidant, anti-carcinogenic, anti-tumor and immunomodulatory properties. However, it remains unclear whether cis-resveratrol may exhibit similar activities. The objective of the present study was to examine the effects of cis- and trans-resveratrol on the production of pro-inflammatory cytokines and mediators in human macrophages. We examined the possibility that cis- and trans-resveratrol may affect cytokine secretion by modulating inflammasomes, intracellular multi-protein complexes, the assembly of which leads to caspase-1 activation and secretion of active IL-1β by macrophages. Our results show that pre-treatment of macrophages with cis-resveratrol not only reduces pro-IL-1β production and IL-1β secretion, but also suppresses ATP-induced transcription and activation of caspase-1 and caspase-4. Notably, cis-resveratrol inhibits the expression of the purinergic receptor, P2X7R, and the endoplasmic reticulum stress marker, Glc-regulated protein 78, but also reduces reactive oxygen species production. Moreover, cis-resveratrol attenuates cyclooxygenase-2 expression and prostaglandin E2 production. cis-Resveratrol also decreases the phosphorylation of p38 MAPK and expression of the c-Jun protein. These results indicate that cis-resveratrol produces anti-inflammatory effects by inhibiting both the canonical and non-canonical inflammasomes, and associated pathways in human macrophages.

Hirsutella sinensis mycelium suppresses interleukin-1β and interleukin-18 secretion by inhibiting both canonical and non-canonical inflammasomes

Cordyceps sinensis is a medicinal mushroom used for centuries in Asian countries as a health supplement and tonic. Hirsutella sinensis—the anamorphic, mycelial form of C. sinensis—possesses similar properties, and is increasingly used as a health supplement. Recently, C. sinensis extracts were shown to inhibit the production of the pro-inflammatory cytokine IL-1β in lipopolysaccharide-treated macrophages. However, the molecular mechanism underlying this process has remained unclear. In addition, whether H. sinensis mycelium (HSM) extracts also inhibit the production of IL-1β has not been investigated. In the present study, the HSM extract suppresses IL-1β and IL-18 secretion, and ATP-induced activation of caspase-1. Notably, we observed that HSM not only reduced expression of the inflammasome component NLRP1 and the P2X7R but also reduced the activation of caspase-4, and ATP-induced ROS production. These findings reveal that the HSM extract has anti-inflammatory properties attributed to its ability to inhibit both canonical and non-canonical inflammasomes.

Ganoderma lucidum stimulates NK cell cytotoxicity by inducing NKG2D/NCR activation and secretion of perforin and granulysin

Ganoderma lucidum (G. lucidum) is a medicinal mushroom long used in Asia as a folk remedy to promote health and longevity. Recent studies indicate that G. lucidum activates NK cells, but the molecular mechanism underlying this effect has not been studied so far. To address this question, we prepared a water extract of G. lucidum and examined its effect on NK cells. We observed that G. lucidum treatment increases NK cell cytotoxicity by stimulating secretion of perforin and granulysin. The mechanism of activation involves an increased expression of NKG2D and natural cytotoxicity receptors (NCRs), as well as increased phosphorylation of intracellular MAPKs. Our results indicate that G. lucidum induces NK cell cytotoxicity against various cancer cell lines by activating NKG2D/NCR receptors and MAPK signaling pathways, which together culminate in exocytosis of perforin and granulysin. These observations provide a cellular and molecular mechanism to account for the reported anticancer effects of G. lucidum extracts in humans.

The medicinal fungus Antrodia cinnamomea suppresses inflammation by inhibiting the NLRP3 inflammasome.

ETHNOPHARMACOLOGICAL RELEVANCE Antrodia cinnamomea--a medicinal fungus that is indigenous to Taiwan--has been used as a health tonic by aboriginal tribes and the Asian population. Recent studies indicate that Antrodia cinnamomea extracts exhibit hepato-protective, anti-hypertensive, anti-oxidative, anti-inflammatory, immuno-modulatory, and anti-cancer effects on cultured cells and laboratory animals. This study aims to explore the anti-inflammatory activity of an Antrodia cinnamomea ethanol extract (ACEE) and elucidate its underlying mechanisms of action using lipopolysaccharide (LPS)-primed, ATP-stimulated human THP-1 macrophages. MATERIALS AND METHODS The effects of ACEE on cell viability were studied using the MTT assay. The expressions of genes, proteins, and pro-inflammatory cytokines were measured by quantitative real-time RT-PCR, Western blotting and ELISA, respectively. The ACEE was further investigated for its effects on reactive oxygen species (ROS) production using ROS detection kit. RESULTS Our results showed that ACEE significantly inhibits ATP-induced secretion of interleukin-1β (IL-1β), interleukin-18 (IL-18) and tumor necrosis factor-α (TNF-α) by LPS-primed macrophages. ACEE also suppresses the transcription and activation of caspase-1, which is responsible for the cleavage and activation of IL-1β and IL-18. Of note, ACEE not only reduces expression of the inflammasome component NLRP3 and the purinergic receptor P2X7R but also inhibits ATP-induced ROS production and caspase-1 activation. Furthermore, the anti-inflammatory properties of ACEE correlate with reduced activation of the MAPK and NF-κB pathways. CONCLUSION The results of the present study indicate that Antrodia cinnamomea suppresses the secretion of IL-1β and IL-18 associated with inhibition of the NLRP3 inflammasome in macrophages. These findings suggest that ACEE may have therapeutic potential for the treatment of inflammatory diseases.

Hirsutella sinensis mycelium attenuates bleomycin-induced pulmonary inflammation and fibrosis in vivo

Hirsutella sinensis mycelium (HSM), the anamorph of Cordyceps sinensis, is a traditional Chinese medicine that has been shown to possess various pharmacological properties. We previously reported that this fungus suppresses interleukin-1β and IL-18 secretion by inhibiting both canonical and non-canonical inflammasomes in human macrophages. However, whether HSM may be used to prevent lung fibrosis and the mechanism underlying this activity remain unclear. Our results show that pretreatment with HSM inhibits TGF-β1–induced expression of fibronectin and α-SMA in lung fibroblasts. HSM also restores superoxide dismutase expression in TGF-β1–treated lung fibroblasts and inhibits reactive oxygen species production in lung epithelial cells. Furthermore, HSM pretreatment markedly reduces bleomycin–induced lung injury and fibrosis in mice. Accordingly, HSM reduces inflammatory cell accumulation in bronchoalveolar lavage fluid and proinflammatory cytokines levels in lung tissues. The HSM extract also significantly reduces TGF-β1 in lung tissues, and this effect is accompanied by decreased collagen 3α1 and α-SMA levels. Moreover, HSM reduces expression of the NLRP3 inflammasome and P2X7R in lung tissues, whereas it enhances expression of superoxide dismutase. These findings suggest that HSM may be used for the treatment of pulmonary inflammation and fibrosis.

Corrigendum: Ganoderma lucidum reduces obesity in mice by modulating the composition of the gut microbiota

This corrects the article DOI: 10.1038/ncomms8489.

Isolation, Culture and Characterization of Hirsutella sinensis Mycelium from Caterpillar Fungus Fruiting Body

The caterpillar fungus Ophiocordyceps sinensis (previously called Cordyceps sinensis) has been used for centuries in Asia as a tonic to improve health and longevity. Recent studies show that O. sinensis produces a wide range of biological effects on cells, laboratory animals and humans, including anti-fatigue, anti-infection, anti-inflammatory, antioxidant, and anti-tumor activities. In view of the rarity of O. sinensis fruiting bodies in nature, cultivation of its anamorph mycelium represents a useful alternative for large-scale production. However, O. sinensis fruiting bodies harvested in nature harbor several fungal contaminants, a phenomenon that led to the isolation and characterization of a large number of incorrect mycelium strains. We report here the isolation of a mycelium from a fruiting body of O. sinensis and we identify the isolate as O. sinensis’ anamorph (also called Hirsutella sinensis) based on multi-locus sequence typing of several fungal genes (ITS, nrSSU, nrLSU, RPB1, RPB2, MCM7, β-tubulin, TEF-1α, and ATP6). The main characteristics of the isolated mycelium, including its optimal growth at low temperature (16°C) and its biochemical composition, are similar to that of O. sinensis fruiting bodies, indicating that the mycelium strain characterized here may be used as a substitute for the rare and expensive O. sinensis fruiting bodies found in nature.