The Involvement of Serotonin in the Hypoglycemic Effects Produced by Administration of the Aqueous Extract of Xylaria nigripes with Steroid-Induced Insulin-Resistant Rats.

Xylaria nigripes (XN) is a medicinal fungus with a high-economic value. The aim of this study was to explore the hypoglycemic effects and mechanisms of the XN aqueous extract in steroid-induced insulin-resistant (SIIR) rats. Significant hypoglycemic effects were observed 60 min after administration of XN aqueous extract. In normal Wistar, hypoglycemic effects were 21% (the plasma glucose level decreased from 128.6 ± 12.5 to 100.9 ± 10.7 mg/dL). In SIIR, hypoglycemic effects were 26% (the plasma glucose level decreased from 177.6 ± 12.5 to 133.3 ± 29.7 mg/dL) rats refer to their baseline. The signaling proteins for insulin-receptor substrate-1 and glucose transporter-4 increased 0.51-fold and 1.12-fold, respectively, as determined by Western blotting; the increase in the proteins was 13% and 9%, respectively, as determined by immunohistochemistry. The serotonin antagonist, α-p-chlorophenylalanine, effectively blocked the hypoglycemic effects and increased the signaling protein levels. After XN administration, none of the animals showed significant changes in plasma-free fatty acids in 60 min. In summary, the XN extract may have hypoglycemic effects in normal Wistar and SIIR rats that may have a serotonin-related hypoglycemic effect and enhance insulin sensitivity in the SIIR rats.

The Anti-Inflammatory Effects and Mechanism of the Submerged Culture of Ophiocordyceps sinensis and Its Possible Active Compounds.

The pharmacological effects of the fruiting body of Ophiocordyceps sinensis (O. sinensis) such as antioxidant, anti-virus, and immunomodulatory activities have already been described, whereas the anti-inflammatory effects and active components of the submerged culture of O. sinesis (SCOS) still need to be further verified. This study aimed to investigate the active compounds in the fermented liquid (FLOS), hot water (WEOS), and 50-95% (EEOS-50, EEOS-95) ethanol extracts of SCOS and their anti-inflammatory effects and potential mechanisms in lipopolysaccharide (LPS)-stimulated microglial BV2 cells. The results demonstrated that all of the SCOS extracts could inhibit NO production in BV2 cells. EEOS-95 exhibited the strongest inhibitory effects (71% inhibitory ability at 500 µg/mL), and its ergosterol, γ-aminobutyric acid (GABA), total phenolic, and total flavonoid contents were significantly higher than those of the other extracts (18.60, 18.60, 2.28, and 2.14 mg/g, p < 0.05, respectively). EEOS-95 also has a strong inhibitory ability against IL-6, IL-1ß, and TNF-α with an IC50 of 617, 277, and 507 µg/mL, respectively, which is higher than that of 1 mM melatonin. The anti-inflammatory mechanism of EEOS-95 seems to be associated with the up-regulation of PPAR-γ/Nrf-2/HO-1 antioxidant-related expression and the down-regulation of NF-κB/COX-2/iNOS pro-inflammatory expression signaling. In summary, we demonstrated that EEOS-95 exhibits neuroinflammation-mediated neurodegenerative disorder activities in LPS-induced inflammation in brain microglial cells.

Enhancing Cordycepin in Functional Porridge through Rice Varietal Fermentation with Cordyceps militaris (Ascomycetes) and Utilizing Non-Targeted Metabolomics for Process Enhancement.

Cordyceps militaris, a medicinal fungus rich in cordycepin, shows promise in treating diseases such as cancer, respiratory issues, and COVID-19. This study examines the impact of different Taiwanese rice varieties on its solid-state fermentation, focusing on optimizing cordycepin production. The results indicated that the cordycepin yield was indeed affected by the type of rice used. In terms of the fruiting bodies, germ rice resulted in the highest yield (13.1 ± 0.36 mg/g), followed by brown rice (11.9 ± 0.26 mg/g). In the rice culture medium (RCM), brown rice led to the highest yield (4.77 ± 0.06 mg/g). Using gas chromatography-mass spectrometry and untargeted metabolomics, the study identifies four key volatile components linked to cordycepin, providing insights into developing functional rice porridge products. These findings are significant for advancing cordycepin mass production and offering dietary options for older individuals.

Aqueous extracts of Cordyceps militaris (Ascomycetes) lower the levels of plasma glucose by activating the cholinergic nerve in streptozotocin-induced diabetic rats.

In our previous research, Cordyceps militaris (CM) had a hypoglycemic effect in normal rats. In this study we wanted to elucidate whether CM also had an effect on diabetic rats. Twelve rats with streptozotocin-induced diabetes were separated randomly into 2 groups. First, aqueous extracts of CM 10 mg/kg (CM group) or saline (control group) was fed to the rats; then the plasma glucose levels were assayed. Second, the signaling proteins IRS-1 and GLUT-4 collected from the muscle were detected. Finally, another 2 groups of rats were injected with atropine 0.1 mg/kg intraperitoneally just before the CM/saline feeding, and the assays mentioned above were repeated. Blood glucose decreased 7.2% in the CM group but only 1.5% in the control group (P < 0.05). The IRS-1 signal was 2.9-fold higher than actin in the CM group but only 0.8-fold higher in the control group (P < 0.005). In GLUT-4 signal, the difference was 1.7- vs. 0.6-fold, respectively, compared with actin (P < 0.05). However, atropine injection made CM-induced hypoglycemia or elevation of IRS-1 and GLUT-4 not significant. In conclusion, CM had a hypoglycemic effect in diabetic rats and atropine blocked it. Therefore, the cholinergic activation also was considered to be involved in the hypoglycemic effect of CM in rats with streptozotocin-induced diabetes.

Effects of yellow brain culinary-medicinal mushroom, Tremella mesenterica Ritz.:Fr. (higher Basidiomycetes), on immune function in normal and type 1 diabetic rats.

Diabetes mellitus (DM) is characterized by systemic low-grade inflammation and altered immunity. The fruiting bodies (FB) of Tremella mesenterica have been demonstrated to have anti-hyperglycemic and immunomodulatory activities. It is unclear whether submerged culture yeast-like cells (CC) of T. mesenterica have the same immune effects as FB. Here, we compared the immune effects of T. mesenterica FB and CC on immunocyte function. Male Wistar rats were intravenously injected with saline (normal rats) or streptozotocin (50 mg/kg, DM rats) and orally treated with placebo, FB, or CC (1 g/kg/day) for 2 weeks. Peripheral blood leukocytes and splenocytes were collected. In normal rats, FB and CC ingestion significantly decreased T-suppressor leukocyte numbers and interferon (IFN)-γ production in leukocytes (p < 0.05). In addition, CC treatment significantly decreased mitogen-stimulated tumor necrosis factor (TNF)-α and interleukin (IL)-6 production in leukocytes as well as the numbers of total and B splenocytes. In DM rats, FB significantly alleviated the diabetes-induced decreases in plasma TNF-α levels, T-helper splenocyte numbers, and IL-6 production in T leukocytes, and CC significantly attenuated the decreases in plasma TNF-α, IFN-γ, and IL-6 levels, as well as the increase in IL-6 production in T splenocytes induced by diabetes. Moreover, CC significantly decreased the numbers of T-helper leukocytes and B splenocytes as well as the production of TNF-α by splenocytes and IL-4 by leukocytes in DM rats. In conclusion, our results suggest that T. mesenterica FB and CC may decrease peripheral cell-mediated immunity in normal rats. However, in diabetic rats, FB may increase peripheral cell-mediated immunity, and CC may decrease pro-inflammatory and Th1 cytokine production.

Polysaccharides of Grifola frondosa ameliorate oxidative stress and hypercholesterolaemia in hamsters fed a high-fat, high-cholesterol diet.

OBJECTIVES: This study was to evaluate the antioxidant and anti-hypercholesterolaemia activities of Grifola frondosa in hamsters fed a high-fat, high-cholesterol (HFHC) diet. METHODS: G. frondosa, including fruiting bodies (FGF), fermented mycelia (MGF) and polysaccharides extracted from fruiting bodies (FPS), fermented mycelia (MIP) and fermented broth (BEP) were received intragastrically. Lipid profile and antioxidant status in the blood and liver of hamsters were assessed. KEY FINDINGS: FGF decreased weight gain, serum triglycerides and cholesterol and increased hepatic mRNA expression of cholesterol-7α-hydroxylase expression. FGF, MGF, FPS and MIP decreased the HFHC diet-increased area under the curve (AUC) of serum cholesterol. FGF and FPS further decreased AUC of serum triglycerides. When evaluating the redox status of erythrocytes, FPS and MIP increased non-protein sulfhydryl (NP-SH) groups, reduced glutathione (GSH) and catalase activity and FPS further increased GSH peroxidase activity. In the liver, MGF increased NP-SH groups and GSH and decreased triglycerides content. FPS, MIP and BEP decreased oxidized GSH and triglycerides content. Moreover, all treatments alleviated HFHC diet-increased LDL oxidation. CONCLUSIONS: Fruiting bodies of G. frondosa may improve hypercholesterolaemia via increased bile acid synthesis. Additionally, fermented biomass and polysaccharides of G. frondosa may have the potential to prevent hepatic lipid accumulation.

Chemical Composition and Chronic Toxicity of Disc-Cultured Antrodia cinnamomea Fruiting Bodies.

Antrodia cinnamomea (AC) is a popular fungus for use as folk medicine in health maintenance and disease prevention and treatment. Disc culture is a novel technique for producing AC fruiting bodies. This study aimed to investigate the bioactive components and toxicological properties of disc-cultured AC fruiting body powders (ACP) in rats. The HPLC technique was used to quantify the composition of bioactive triterpenoids in ACP. Toxicological properties were evaluated on male and female Sprague-Dawley rats receiving ACP orally at 200, 600, and 1000 mg/kg body weight for 90 days; the control group received only distilled water. The results show that ACP contained seven important AC index compounds, namely antcins A, B, C, K, and H, dehydrosulphurenic acid, and dehydroeburicoic acid. At the tested doses, oral ACP administration for 90 days caused no mortality, adverse effects on general health, body and organ weights, and food intake. Furthermore, no significant variations were observed in hematological and biochemical parameters among either sex of ACP-treated and control animals. An histopathological examination of vital organs showed no significant structural changes in organs, even in high-dose ACP-treated animals. This study indicated that ACP contained the major bioactive triterpenoids of AC fruiting bodies, and its no-observed-adverse-effect level (NOAEL) was 1000 mg/kg/day, about 20 times the recommended daily intake.

Effects of Cordyceps militaris fermentation products on reproductive development in juvenile male mice.

Cordyceps militaris (CM) is a popular medicinal fungus; however, few studies have focused on its impact on the male reproductive system. We evaluated the effects of CM fermentation products on the reproductive development of juvenile male (JM) mice. Mice were divided into four experimental groups, each fed 5% CM products (weight per weight (w/w) in normal diet): extracellular polysaccharides (EPS), fermentation broth (FB), mycelia (MY), and whole fermentation products (FB plus MY, FBMY) for 28 days, while mice in the control group (CT) were fed a normal diet. Basic body parameters, testicular structure, sperm parameters, and sex hormones concentrations were analyzed. Compared to the CT group, mice in the EPS, MY, and FBMY groups showed a significantly increased mean seminiferous tubule area (p < 0.05), mice in the FB and MY groups had significantly higher sperm concentrations (p < 0.05), and mice in the EPS, FB, and FBMY groups showed significantly increased ratios of motile sperm (p < 0.05). Meanwhile, EPS significantly promoted the ability of JM mice to synthesize testosterone (p < 0.05). Furthermore, all CM products significantly increased the food intake of JM mice (p < 0.05) but did not significantly change their water intake and body weight gain (p > 0.05). In conclusion, CM products, especially EPS, exhibit strong androgen-like activities that can promote male reproductive development.

28-day oral safety evaluation of extracellular polysaccharopeptides produced in submerged culture from the turkey tail medicinal mushroom Trametes versicolor (L.:Fr.) Pilát LH-1 in mice.

Turkey tail medicinal mushroom, Trametes versicolor (TV), is a species with a variety of pharmacological activities. Its intracellular polysaccharopeptides are widely commercialized. Recently, we found a novel TV strain LH-1 in Taiwan and demonstrated that the extracellular polysaccharopeptide (ePSP) of LH-1 obtained from submerged culture exhibits significant immunomodulatory activity. In this in vivo study, we further evaluated the safety of orally administered LH-1 ePSP using both male and female ICR mice. The LH-1 ePSP was orally administered to mice at levels of 0 (water), 100 (low dose), 500 (medium dose), or 1000 mg/kg/day (high dose) for 28 days. Clinical observations, growth, food consumption, histopathological examination, and clinical biochemical analyses revealed no adverse effects of LH-1 ePSP in mice. There were no significant differences in the results of target organ weights, hematological analyses, and urinalysis examination among groups. However, male mice that ingested high doses of LH-1 ePSP tended to have decreased lung weights and platelet numbers. In conclusion, the results of the present study suggested that oral administration of LH-1 ePSP for 28 days is accompanied by no obvious signs of toxicity. The lack of toxicity supports the potential use of LH-1 ePSP as a food or dietary supplement.

Hypoglycemic Effect of Electroacupuncture Combined with Antrodia cinnamomea in Dexamethasone-Induced Insulin-Resistant Rats.

Objective: Antrodia cinnamomea (AC), a medicinal mushroom indigenous to Taiwan, exerts various pharmacologic activities. This study compared and evaluated the hypoglycemic effect of treatment with electroacupuncture (EA) combined with AC in steroid-induced insulin-resistant (SIIR) rats. Materials and Methods: Rats were divided into saline, EA, AC, AC+EA, and rosiglitazone (TZD) groups. Plasma-glucose levels were measured in serial blood samples and compared before and after treatment in each group. The levels of signaling proteins-glucose transporter 4, (GLUT4), phosphoinositide 3-kinase (PI3-K), and 5' adenosine monophosphate-activated protein kinase (AMPK)-were analyzed by Western blotting to explore their mechanisms of action. Results: The AC+EA group had reduced plasma-glucose levels at 30 and 60 minutes in SIIR rats, compared to normal rats, and this was better than the EA, AC, and TZD groups at 60 minutes. Furthermore, the signaling protein (GLUT4, PI3-K, and AMPK) levels were increased significantly. Conclusions: These findings showed improved hypoglycemic activity and insulin resistance after EA combined with AC treatment. Therefore, the combined therapy might be a more-effective method than the individual therapies that elevates the expression of the signal proteins, as observed in this study.

Extracellular Polysaccharopeptides from Fermented Turkey Tail Medicinal Mushroom, Trametes versicolor (Agaricomycetes), Mitigate Oxidative Stress, Hyperglycemia, and Hyperlipidemia in Rats with Type 2 Diabetes Mellitus.

The antihyperglycemic activity of extracellular polysaccharopeptides (ePSP) obtained from Trametes versicolor (TV) strain LH-1 has been reported to increase cellular glucose uptake in HepG2 cells in an insulin-independent manner. Evidence indicates that oxidative stress plays a pivotal role in the development of diabetic complications. We aimed to use an in vivo model to investigate the effects of TV-ePSP on oxidative stress and glucose homeostasis in type 2 diabetes mellitus (T2DM). Male Wistar rats fed with a high fat diet followed by a streptozotocin injection to induce T2DM were orally administered water or 0.1, 0.5, or 1.0 g/kg of TV-ePSP per day. After a 4-week administration of TV-ePSP, T2DM rats had attenuated elevations in blood glucose levels, areas under the curve in oral glucose tolerance tests, insulin resistance indices, and serum fructosamine and triglyceride in a dose-dependent manner (P < 0.05, one-way ANOVA). In addition, TV-ePSP significantly alleviated oxidative stress in T2DM rats, as shown by the decreased lipid peroxidation and the increased activity of superoxide dismutase in the plasma, and by the elevated glutathione levels in the plasma and erythrocytes. The antihyperglycemia and antihypertriglyceridemia activities of TV-ePSP may be associated with the improved oxidative stress, suggesting the beneficial effects of TV-ePSP in preventing the development of diabetic complications in T2DM patients.

Fruiting Bodies of Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes) Alleviate Diabetes-Associated Oxidative Stress.

Hyperglycemia-induced complications, the major causes of death in diabetes, are closely related to the elevated oxidative stress. Our previous study indicated that fruiting bodies of Ophiocordyceps sinensis attenuated polydipsia and hyperglycemia in diabetic rats. In this study, we further investigated whether the protective effects of O. sinensis on diabetes are associated with improved oxidative status in the circulation and target organs, the liver and kidneys. Male Wistar rats were fed with a semipurified diet supplemented with fruiting bodies (FB group, 1 g/day), carcass (CC group, 1 g/day), fruiting bodies and carcass (CF group, each 0.5 g/day), or placebo (DM and R groups) for 4 weeks (day 1 to 29). On day 15, animals were injected with nicotinamide (200 mg/kg) and streptozotocin (65 mg/kg) to induce diabetes. After the induction of diabetes, fasting blood glucose (FBG) was increased and the diabetes-increased FBG (day 15 to 26) was alleviated by the supplementation of fruiting bodies (p < 0.05, one-way ANOVA). In addition, the contents of vitamins A and C in the liver were significantly higher in the FB group, and the contents of glutathione in the liver and vitamin A and C in the kidneys were significantly higher in the FB, CC, and CF groups than in the DM group. The diabetes-increased glutathione peroxidase activity in the liver was decreased in the CF group. These results suggest that O. sinensis, especially fruiting bodies, may have antihyperglycemic activity associated with the alleviated oxidative stress in the liver and kidneys.

Acetylsalicylic acid-like analgesic effects of Trametes versicolor in Wistar rats.

The aim of the present study was to investigate the analgesic effects and mechanism of action of Trametes versicolor (Tv) mycelium powder. Wistar rats were randomly divided into the following three or four groups: i) Saline group, fed saline; ii) Tv 500 group, fed 500 mg/kg Tv; iii) ASA 50 group, fed 50 mg/kg acetylsalicylic acid (ASA); and iv) ASA 100 group, fed 100 mg/kg ASA. Chemical formalin tests and thermal hot plate tests were used to investigate the analgesic effects of each group. ELISAs were performed to detect cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) plasma levels, and high-performance liquid chromatography (HPLC) was used for quality control the active component, oleanolic acid (OA) in Tv that had the analgesic effect. The OA content in aqueous Tv extract was found to be 11.92 % by HPLC assays. The licking frequencies in the early phase and late phase of the formalin test were significantly lower in the Tv 500 and ASA 100 groups than the saline group. The licking time in the late phase were also significantly lower in the Tv 500 and ASA 100 groups than the saline group. The plasma levels of COX-2 and PGE2 were decreased significantly in the Tv 500 and ASA 100 groups compared with that of the saline group at 60 min in the formalin test. In addition, oral feeding with 500 mg/kg Tv may effectively reduce physical pain triggered by hot plates in Wistar rats. Taken together, the acetylsalicylic acid-like analgesic effects of Tv in Wistar rats may be associated with the reduction of the plasma COX-2 and PGE2 levels.

Electroacupuncture combined with acarbose improves insulin sensitivity via peroxisome proliferator-activated receptor γ activation and produces a stronger glucose-lowering effect than acarbose alone in a rat model of steroid-induced insulin resistance.

BACKGROUND: Previous studies have reported that electroacupuncture (EA) induces a glucose-lowering effect by improving insulin resistance (IR) and reduces plasma free fatty acid (FFA) levels in rats with steroid-induced insulin resistance (SIIR). In addition, EA can activate cholinergic nerves and stimulate endogenous opioid peptides to lower plasma glucose in streptozotocin-induced hyperglycemic rats. The aim of this study was to investigate the glucose-lowering effects of 15 Hz EA at bilateral ST36 in combination with acarbose (ACA). We hypothesized that EA combined with ACA would produce a stronger glucose-lowering effect than ACA alone. METHODS: In this study, normal Wistar rats and SIIR rats were randomly divided into two groups: ACA and ACA + EA. To explore the potential mechanisms underlying the glucose-lowering effect, plasma FFA/insulin and insulin transduction signal pathway proteins were assayed. RESULTS: Combined ACA + EA treatment had a greater glucose-lowering effect than ACA alone in normal Wistar rats (-45% ± 3% vs -19% ± 3%, p < 0.001) and SIIR model rats (-43% ± 2% vs -16% ± 6%, p < 0.001). A significant reduction in plasma FFA levels, improvement in homeostatic model assessment of IR (HOMA-IR) index (-48.9% ± 4.0%, p < 0.001) and insulin sensitivity index (102% ± 16.9%, p < 0.001), and significant increases in insulin receptor substrate 1, glucose transporter 4, and peroxisome proliferator-activated receptor γ protein expressions in skeletal muscle, were also observed in the ACA + EA group of SIIR rats. CONCLUSION: Combined EA and ACA therapy had a greater glucose-lowering effect than ACA monotherapy; this combined therapy could be more effective at improving IR in SIIR rats, which may be related to a reduction in plasma FFA levels and an elevation of insulin signaling proteins. Whether this combined therapy has an effect in type 2 diabetes mellitus (T2DM) patients still needs to be explored.

Polyethylene Glycol6000/carbon Nanodots as Fluorescent Bioimaging Agents.

Photoluminescent nanomaterials have immense potential for use in biological systems due to their excellent fluorescent properties and small size. Traditional semiconductor quantum dots are heavy-metal-based and can be highly toxic to living organisms, besides their poor photostability and low biocompatibility. Nano-sized carbon quantum dots and their surface-modified counterparts have shown improved characteristics for imaging purposes. We used 1,3, 6-trinitropyrene (TNP) and polyethylene glycol6000 (PEG6000) in a hydrothermal method to prepare functional polyethylene glycol6000/carbon nanodots (PEG6000/CDs) and analyzed their potential in fluorescent staining of different types of bacteria. Our results demonstrated that PEG6000/CDs stained the cell pole and septa of gram-positive bacteria B. Subtilis and B. thuringiensis but not those of gram-negative bacteria. The optimal concentration of these composite nanodots was approximately 100 ppm and exposure times varied across different bacteria. The PEG6000/CD composite had better photostability and higher resistance to photobleaching than the commercially available FM4-64. They could emit two wavelengths (red and green) when exposed to two different wavelengths. Therefore, they may be applicable as bioimaging molecules. They can also be used for differentiating different types of bacteria owing to their ability to differentially stain gram-positive and gram-negative bacteria.

Induction of apoptosis in human lung carcinoma A549 epithelial cells with an ethanol extract of Tremella mesenterica.

Tremella mesenterica (TM) is a common food and folk medicine widely used in several Asian countries as a tonic for the lungs. In the present study, we compared the effects of extracellular polysaccharides (EPS), intracellular polysaccharides (IPS), and ethanol extract (EE) of Tremella mesenterica on the induction of apoptosis into human lung carcinoma A549 epithelial cells. The EE, but not the EPS or the IPS, almost completely inhibited the growth of A549 cells. The results of Annexin V-FITC/PI staining and flow cytometric analysis indicated that the percentage of Annexin V(+)/PI(-) cells in EE-treated cells increased to 32.8%. The results of further investigation showed a disruption of mitochondrial transmembrane potential (DeltaPsi(m)), the production of reactive oxygen species (ROS), and the activation of caspase-3 protein in EE-treated cells. These findings suggest that EE can decrease cell viability and induce apoptosis in A549 cell lines by activating a mitochondrial pathway.

Effects of Lycium barbarum extract on production and immunomodulatory activity of the extracellular polysaccharopeptides from submerged fermentation culture of Coriolus versicolor.

Polysaccharopeptides (PSPs) from Coriolus versicolor have been used as immunomodulatory and anticancer agents. However, most studies have concentrated on the mycelial PSPs and not those in the fermented broth. On the other hand, Lycium barbarum fruit has been used as a traditional Chinese herbal medicine for two millennia. Its extract contains various nutrients, minerals, and also polysaccharide-protein complexes, which are proven to be bioactive. Herein we report the effects of L. barbarum fruit extract on the mycelial growth and extracellular PSP (ePSP) production of C. versicolor LH1 by using a submerged fermentation process in 20l fermenters. Fermentation production of C. versicolor biomass and its ePSP were augmented in the presence of L. barbarum extract. The ePSP such obtained differs from those obtained with normal culture medium in terms of simple sugar composition and protein content but shows similar overall chemical structures as analyzed by Fourier transformed infrared spectroscopy. Moreover, the ePSP from C. versicolor cultured with supplementary L. barbarum extract exhibits significant immunomodulatory activity as judged by its effects on the production of nitric oxide and several cytokines by murine RAW264.7 macrophages.

Submerged culture mycelium and broth of Grifola frondosa improve glycemic responses in diabetic rats.

Grifola frondosa, an edible fungus with a large fruiting body and overlapping caps, has been demonstrated to be a natural source of health-promoting substances, mainly due to its polysaccharides beta-glucan. By using male Wistar rats injected with saline (normal rats) or nicotinamide plus streptozotocin (diabetic rats), we investigated the effects of an orally ingested placebo (CON and STZ groups), culture mycelium (CGM and SGM groups), broth (CGB and SGB groups), and mycelium plus broth (CGX and SGX groups) of Grifola frondosa on glycemic responses. During the experimental period (from day 0 to day 15), the STZ group had significantly lower body weight compared to the CON group (one-way ANOVA, p<0.05). Moreover, the STZ group had significantly higher blood glucose concentrations at 2 hour-postprandial periods on days 0, 7, and 14 and in an oral glucose tolerance test (OGTT) on day 10, as well as significantly higher serum fructosamine and triglyceride on day 15 compared to the CON group. These diabetes-induced increases were significantly attenuated by administrations of mycelium and/or broth, i.e., the SGM, SGB, and SGX groups. The results of repeated-measures analysis and three-way ANOVA indicated that diabetes mellitus significantly increases, and mycelium administration significantly decreases postprandial blood glucose; diabetes mellitus significantly increases, and mycelium and broth administrations significantly decrease serum triglyceride, fructosamine, and blood glucose concentrations; moreover, in the area under the curve in OGTT, p<0.05. Our results revealed that submerged-culture mycelia and broth of Grifola frondosa have bioactivities for improving glycemic responses.

Potential activities and mechanisms of extracellular polysaccharopeptides from fermented Trametes versicolor on regulating glucose homeostasis in insulin-resistant HepG2 cells.

Polysaccharides derived from mushrooms have potential to control blood sugar, reduce insulin resistance and prevent diabetic complications. The intracellular polysaccharopeptides of Trametes versicolor (TV) have been used as immunologic and oncologic adjuvants. The aim of this study was to investigate the potential activities and mechanisms of extracellular polysaccharopeptides (ePSP) obtained from TV strain LH-1 on regulating glucose homeostasis. Human hepatoma HepG2 cells incubated with normal glucose (5.5 mM, NG model), high glucose (33 mM, HG model), or high glucose (33 mM) plus high insulin (10-7 M, HGI model) concentrations were administered with TV LH-1 ePSP (50, 100, and 1000 µg/ml) for 24 hr. Glucose uptake of HepG2 cells, determined by flow cytometry, was significantly decreased in the HG and HGI models with insulin stimulation, suggesting insulin resistance of these cells; however, ePSP reversed this decrease in a dose-dependent manner (one-way ANOVA, p<0.05). In the HG and HGI models, ePSP significantly increased glycogen content, insulin receptor substrate-2 protein and phosphorylated AMP-activated protein kinase (AMPK), as determined by western blot analysis. In addition, ePSP significantly increased glucokinase in the NG and HG models, increased membrane glucose transporter-1 and decreased glycogen synthase kinase-3ß in the HGI model, and increased glucose-6-phosphatase in the NG and HGI models (one-way ANOVA, p<0.05). In summary, TV LH-1 ePSP may elevate cellular glucose uptake to regulate glucose homeostasis via the activation of AMPK and glycogen synthesis in an insulin-independent manner. These results suggest that TV LH-1 ePSP may be a nutraceutical with anti-hyperglycemic activity.

Improving insulin resistance with Antrodia cinnamomea mycelium powder to induce a hypoglycemic effect in dexamethasone­induced insulin­resistant rats.

Insulin resistance is a major factor in type II diabetes development, occurring when insulin levels are normal, but do not have normal interactions with adipose, muscle or liver tissue. The present study aimed to explore the hypoglycemic effect of Antrodia cinnamomea (AC) mycelium powder by evaluating its impact on insulin resistance and plasma free fatty acid (FFA) levels in steroid­induced insulin­resistant (SIIR) rats. Male Wistar rats were administered dexamethasone for 5 days to induce insulin resistance. The SIIR rats were subsequently randomly assigned into three experimental groups (EGs) and a control group (CG), where saline was orally administered. The EGs were orally administered different doses of AC (100, 200 or 500 mg/kg) and an optimal dose for further study was determined. Changes in plasma insulin and glucose levels were calculated to investigate the hypoglycemic effect of AC. To evaluate insulin resistance, the homeostasis model assessment­estimated insulin resistance of the SIIR rats was determined. Changes in plasma FFA levels were detected and levels of insulin signal proteins (IRS­1, GLUT­4 and PI3K) were analyzed by western blot to elucidate AC's mechanism of action. The SIIR rats exhibited significantly decreased plasma glucose levels in the first 30 min, with plasma FFA levels displaying a marked downward trend (P<0.05) when they were administered the optimal dose of AC (200 mg/kg). The decrease in plasma glucose and FFA levels was significantly larger in the EG compared to the CG, and insulin signal protein levels were also significantly increased (P<0.05). The hypoglycemic effect observed may be due to decreased plasma FFA levels and increased expression of intracellular insulin signal proteins. Furthermore, insulin sensitivity was enhanced, indicating that AC acts as an insulin sensitizer in insulin resistant animal models.