Effects of different extraction temperatures on the physicochemical properties of bioactive polysaccharides from Grifola frondosa.

This study examined the effects of different extraction temperatures (70°C, 100°C and 121°C) on the physicochemical properties of water soluble polysaccharides (WSP; GF70, GF100 and GF121, respectively) from Grifola frondosa (GF) fruiting bodies, and evaluating their effects on nitric oxide (NO) production in lipopolysaccharide-stimulated RAW264.7 macrophages. Results showed that GF121 had the highest yield. GF70, GF100 and GF121 contained a similar monosaccharide composition and the predominant monosaccharide was glucose. These polysaccharides contained two major macromolecular populations; the high molecular weight population showed a clear trend of reduced molecular weight with increasing extraction temperature. GF121 contained the highest amount of (1→3, 1→6)-ß-d-glucans, while the degree of branching in all samples was similar. GF WSP possessed NO inhibitory activity, and the strongest was GF121. This study concludes that WSP are good sources of food ingredients, and high temperature extraction could improve the quantity and quality of GF WSP.

Comparative characterization of physicochemical properties and bioactivities of polysaccharides from selected medicinal mushrooms.

Mushroom polysaccharides have been known to possess various pharmacological activities. However, information on their chemical and biological differences between mushrooms remains limited. In this study, we aimed to examine the differences in physicochemical characteristics of polysaccharides prepared from Antrodia cinnamomea (AC-P), Coriolus versicolor (CV-P), Grifola frondosa (GF-P), Ganoderma lucidum (GL-P), and Phellinus linteus (PL-P), followed by evaluating their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Results showed that under similar conditions of preparation, the monosaccharide composition of polysaccharides varied between different mushrooms, and glucose was the predominant monosaccharide, followed by galactose and mannose. AC-P and GF-P contained the highest amount of (1,3;1,6)-ß-D-glucans. The degree of branching of (1,3;1,6)-ß-D-glucans in all polysaccharides ranged from 0.21 to 0.26, with the exception of GF-P (0.38). The molecular weights of different polysaccharides showed diverse distributions; AC-P, CV-P, and GF-P contained two major macromolecular populations (< 30 and >200 kDa) and possessed triple-helix conformation, whereas GL-P (10.2 kDa) and PL-P (15.5 kDa) only had a low molecular weight population without triple-helix structure. These polysaccharides showed different inhibitory potency on NO production in LPS-stimulated RAW264.7 cells.

Effects of Grifola frondosa non-polar bioactive components on high-fat diet fed and streptozotocin-induced hyperglycemic mice.

CONTEXT: Consumption of medicinal mushrooms for disease prevention and maintaining health has a very long history in Asia. Grifola frondosa (Fr) S.F. Gray (GF) (Meripilaceae) is a medicinal fungus popularly used for enhancing immune systems, lowering blood glucose, and improving spleen, stomach, and nerve functions. OBJECTIVE: This study examines the hypoglycemic effects of GF in vitro and in vivo, and analyzes the chemical profiles of its bioactive components. MATERIALS AND METHODS: In vitro hypoglycemic effects of GF was evaluated enzymatically using α-amylase and α-glucosidase inhibition assays, whereas in vivo study was conducted on high-fat diet fed and streptozotocin (HFD + STZ)-induced hyperglycemic mice. GC-MS was used to determine the chemical profiles of bioactive components. RESULTS: The non-polar fraction of GF exhibited a stronger anti-α-glucosidase activity (IC50: 0.0332 mg/ml) than acarbose, but its anti-α-amylase activity (IC50: 0.671 mg/ml) was weaker. Oral administration of GF at 600 mg/kg (GF600) significantly lowered the blood glucose, HbA1c, average blood glucose, and serum total cholesterol levels in hyperglycemic mice. Although GF was found to contain mainly oleic acid and linoleic acid, their levels in the fungus were low, suggesting that the effects of GF on HFD + STZ-induced hyperglycemic mice could be due to factors other than these fatty acids. CONCLUSION: These results conclude that GF possesses anti-α-glucosidase activity, and hypoglycemic effect in HFD + STZ-induced hyperglycemic mice.

Inhibitory potential of Grifola frondosa bioactive fractions on α-amylase and α-glucosidase for management of hyperglycemia.

This study examined the inhibitory effects of Grifola frondosa (GF), a medicinal mushroom popularly consumed in traditional medicine and health food, on digestive enzymes related to type 2 diabetes; chemical profiles and inhibitory kinetics of its bioactive fractions were also analyzed. Results showed that all GF extracts showed weak anti-α-amylase activity; however, strong anti-α-glucosidase activity was noted on GF n-hexane extract (GF-H). Further fractionation confirmed that compared with acarbose (a commercial α-glucosidase inhibitor), the nonpolar fraction of GF possessed a stronger anti-α-glucosidase activity but a weaker anti-α-amylase activity. These activities were not derived from ergosterol and ergosterol peroxide, two major compounds of this fraction. The inhibitory kinetics of GF-H on α-glucosidase was competitive inhibition. GF-H was as good as acarbose in inhibiting the starch digestion in vitro. Oleic acid and linoleic acid could be the major active constituents that have contributed to the potency of GF in inhibiting α-glucosidase activity.

Antioxidant and antiedema properties of solid-state cultured honey mushroom, Armillaria mellea (higher Basidiomycetes), extracts and their polysaccharide and polyphenol contents.

Culinary-medicinal honey mushroom or Mi-Huan-Ku, Armillaria mellea (AM), is a popular ingredient in the traditional Chinese medicine for treating diseases of geriatric patients. This study aimed to examine the effect of cultured substrates on the mycelial growth of AM and evaluate its antioxidant and antiedema activities as well as its total polysaccharide and polyphenol contents. Results showed that AM grew best on the maize medium and worst on the potato medium. AM ethanol extract (AM-EtOH) showed stronger DPPH radical scavenging activity than AM aqueous extract (AM-H2O). However, they were weak in metal chelation and reducing power. AM-EtOH but not AM-H2O at 200 mg/kg showed antiedema activity in rats. The total ß-glucan content of AM-H2O and AM-EtOH was 21.95% and 3.50%, respectively. AM-EtOH showed higher phenol but lower flavonoid content than AM-H2O. These results indicate that maize is a good source of substrate for mass production of AM mycelia, and its potency of DPPH radical scavenging and antiedema activities was contributed mainly by the phenolic compounds, not the level of polysaccharide content.

Inhibitory effects of medicinal mushrooms on α-amylase and α-glucosidase - enzymes related to hyperglycemia.

In Asia, medicinal mushrooms have been popularly used as folk medicine and functional foods. In this study, our aim was to examine the inhibitory effects of six medicinal mushrooms on key enzymes (α-amylase and α-glucosidase) related to hyperglycemia; chemical profiles of bioactive extracts were also examined. The results showed that the n-hexane extract of Coriolus versicolor had the strongest anti-α-amylase activity, while the n-hexane extract of Grifola frondosa showed the most potent anti-α-glucosidase activity. Compared with acarbose, the anti-α-amylase activity of all mushroom extracts was weaker, however a stronger anti-α-glucosidase activity was noted. GC-MS analysis showed that the magnitude of potency of inhibiting α-glucosidase activity varied with the levels of oleic acid and linoleic acid present in the extracts. These findings were consistent with the IC50 values of these free fatty acids on inhibiting α-glucosidase activity. Taken together, this study suggests that oleic acid and linoleic acid could have contributed to the potent anti-α-glucosidase activity of selected medicinal mushrooms.

Immunomodulatory activities of medicinal mushroom Grifola frondosa extract and its bioactive constituent.

Grifola frondosa (GF), a high value medicinal mushroom in China and Japan, is popularly consumed as traditional medicines and health foods, especially for enhancing immune functions. In this study, our aim was to examine the immunomodulatory activities of GF and its bioactive compound ergosterol peroxide (EPO) in lipopolysaccharide (LPS)-induced human monocytic (THP-1) cells. At low concentrations, EPO but not other extracts showed a full protection against LPS-induced cell toxicity. EPO significantly blocked MyD88 and VCAM-1 expression, and cytokine (IL-1ß, IL-6 and TNF-α) production in LPS-stimulated cells. It also effectively inhibited NF-κB activation, which was further confirmed with siRNA treatment. These results conclude that EPO may play an important role in the immunomodulatory activity of GF through inhibiting the production of pro-inflammatory mediators and activation of NF-κB signaling pathway.

Immunomodulatory properties of Xylaria nigripes in peritoneal macrophage cells of Balb/c mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Wu Ling Shen, a folklore name for Xylaria nigripes (XN), is a high value medicinal fungus used in traditional Chinese medicine. AIM OF STUDY: The present study aimed to examine the immunomodulatory properties of aqueous (XN-H) and ethanol (XN-E) XN extracts in lipopolysaccharide (LPS)-induced peritoneal macrophage cells of Balb/c mice. MATERIALS AND METHODS: After treating the macrophage cells with LPS (1 µg/ml) and different XN extracts, the immunomodulatory properties were determined by the responses of inflammatory mediators, namely nitrite oxide (NO), prostaglandin E2 (PGE(2)) and cytokine (IL-1ß, IL-6, TNF-α and IFN-γ) production, iNOS, COX-2 and IκB-α expression, and NF-κB activation. RESULTS: Results showed that treatment of macrophages with 5-30 µg/ml of XN-H or XN-E plus 1 µg/ml LPS exhibited no cytotoxic effect on cell viability. At these concentrations, although both XN-H and XN-E showed a dose-dependent inhibitory effect on NO, PGE(2), IL-1ß, IL-6, TNF-α and IFN-γ production in LPS-stimulated macrophages, a greater potency was noted in the XN-H treated group. RT-PCR assay also showed that XN-H possessed a greater inhibition than XN-E on iNOS and COX-2 RNA expression. Furthermore, XN-H also showed a significant stronger suppression than XN-E on the LPS-induced IκB-α phosphorylation and NF-κB activation. XN-E showed a higher total flavonoid and phenol contents but a lower ß-glucan content than XN-H. CONCLUSION: Taken together, these results conclude that XN-H possesses a stronger anti-inflammatory activity than XN-E, and its mechanism of action could be mediated by inhibiting iNOS and COX-2 expression via the NF-κB signaling pathway, and these activities could be contributed by the ß-glucan content.

Protective effects of Wu-Ling-Shen (Xylaria nigripes) on carbon tetrachloride-induced hepatotoxicity in mice.

Wu-Ling-Shen, a lesser study medicinal fungus (Xylaria nigripes), is popular for treating insomnia and trauma in the traditional Chinese medicine. In this study, our aim was to examine the protective effects of X. nigripes extract on carbon tetrachloride (CCl(4))-induced acute hepatotoxicity in mice, and its content of polyphenolic constituents. The X. nigripes aqueous extract (XN-T) at 500 and 1000 mg/kg was given intragastrically to mice for 9 consecutive days, followed by receiving subcutaneously 2 mL/kg of 40% CCl(4) in olive oil to induce hepatotoxicity. Blood and liver tissues were collected for biochemical and histological analyses. Analysis of polyphenolic compounds was performed by RP-HPLC. Results showed that XN-T at 500 and 1000 mg/kg significantly prevented the elevation of serum glutamate oxalate transaminase (sGOT), serum glutamate pyruvate transaminase (sGPT), and liver thiobarbituric acid reactive substances (TBARS) levels, and caused an increase in the liver superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) concentrations, as well as serum total antioxidant activity in the CCl(4)-induced hepatotoxicated mice. It was as good as silymarin (100 mg/kg) in normalization of oxidative stress parameters. Furthermore, liver histological observation also showed an obvious amelioration in the liver conditions in XN-T-treated animals. XN-T was found to contain a higher level of epicatechin, catechin, and p-coumaric acid. These results conclude that XN exerts effective protection against CCl(4)-induced liver injury in mice, and its mechanism of action could be through the effects of antioxidants on reducing the oxidative stress.

Antioxidant and antiradical activities of Wu Ling Shen in a cell free system.

The present study aimed to investigate the antioxidant and antiradical activities of Wu Ling Shen, a popular medicinal fungus (Xylaria nigripes) used in traditional Chinese medicine preparations. Two different X. nigripes materials, the cultivated X. nigripes mycelia (XN) and a commercial X. nigripes product (XNP), were used to prepare the aqueous (XN-H vs. XNP-H) and ethanol (XN-E vs. XNP-E) extracts for this study. Polyphenol and total polysaccharide contents of these extracts were also examined. Results showed that extracts of XN possessed stronger antioxidant and antiradical activities than XNP in all tested model systems. However, all extracts exhibited a weak activity in metal chelation and reducing power. Total antioxidant activity of XN extracts (IC50 6.20 microg/ml for XN-H and 5.41 microg/ml for XN-E), but not XNP extracts (IC50 128.13 microg/ml for XNP-H and 96.16 microg/ml for XNP-E), was more potent than Trolox (IC50 19.64 microg/ml) and vitamin C (IC50 26.39 microg/ml). XN-E (IC50 5.12 microg/ml) and XNP-E (IC50 8.89 microg/ml) possessed a relatively similar potency as that of positive controls (IC50 6.94 microg/ml for Trolox and 4.25 microg/ml for vitamin C) in the superoxide radical scavenging activity. Although the DPPH radical scavenging of XN extracts was weaker than that of Trolox and vitamin C, it was about eight times more potent than that of XNP extracts. In ABTS assay, both XN and XNP extracts exhibited a moderate ABTS radical scavenging activity. Among the different extracts, XN-E showed the highest total flavonoid (32.69 mg/g) and phenol (59.75 mg/g) contents, while XNP-H (7.50% w/w) had the highest level in total polysaccharide content. These results conclude that XN-E possesses the most potent antioxidant and antiradical activities, and that these activities could be derived from its high polyphenol content, but not the level of polysaccharides.

Improvement of sperm production in subfertile boars by Cordyceps militaris supplement.

Cordyceps species have been traditionally used for the enhancement of sexual function, however, there is few direct evidence to prove this. We investigated the spermatogenic effect of Cordyceps militaris (CM) by supplementation with CM mycelium to subfertile boars. Seventeen Duroc and 12 Landrace boars (29 to 40 months old) were selected to feed with regular diet (control groups, n = 8 and 6, respectively) or diet supplemented with CM mycelium (treatment groups, n = 9 and 6, respectively) for 2 months. Semen was collected once a week. The quality of fertile sperm (normally greater than 62% of motility and 70% of normal morphology) and the quantity (semen volume, and total sperm number) were compared in these boars. The result showed that sperm production was enhanced significantly at the end of first month (p < 0.05), peaked at the second month (p < 0.01) of supplementation with CM and was maintained for 2 weeks after stopping the treatment (p < 0.01). Plasma cordycepin concentration was detected in boars supplemented with CM but not in the controls. More importantly, the percentages of motile sperm cells and sperm morphology were also improved significantly in most of treated boars during the second month of supplementation (p < 0.01) and 2 weeks after the treatment (p < 0.05) as compared to their initial values. These results indicate that supplementation with CM mycelium improves sperm quality and quantity in subfertile boars and may partly support the role of Cordyceps in sexual enhancement.

Armillariella mellea shows anti-inflammatory activity by inhibiting the expression of NO, iNOS, COX-2 and cytokines in THP-1 cells.

Armillariella mellea (AM), also known as Mi-Huan-Ku, a popular medicinal fungus used in the traditional Chinese medicine for treating headache, neurasthenia and insomnia. In the present study, our aim was to determine the effects of aqueous (AAM) and ethanol (EAM) extracts of A. mellea on lipopolysaccharide (LPS)-induced inflammatory response by measuring the inducible nitric oxide synthase (iNOS), cyclooxygenase-1 and -2 (COX-1 and COX-2) protein expression, cytokines (TNF-alpha, IL-4 and IL-8) formation, nitric oxide (NO) release and prostaglandin (PGE(2)) production in human monocytic (THP-1) cells. At concentration of 100 microg/ml, EAM, but not AAM, effectively protected against LPS-induced cell death in THP-1 cells. At concentrations of 10 approximately 100 microg/ml, EAM showed a potent anti-inflammatory activity as demonstrated by a dose-dependent inhibition of LPS (1 microg/ml)-induced release of NO and PGE(2), and significantly decreased the transcription of proinflammatory cytokines. EAM at 100 mug/ml significantly blocked the LPS induction of iNOS and COX-2 expression, but not COX-1. Therefore, the protective effect of EAM against LPS-induced inflammatory mediators release could explain, at least in part, its effectiveness in alleviating certain inflammatory related diseases.

Neuroprotective diterpenes from the fruiting body of Antrodia camphorata.

Three new compounds, 19-hydroxylabda-8(17)-en-16,15-olide (1), 3beta,19-dihydroxylabda-8(17),11E-dien-16,15-olide (2), and 13-epi-3beta,19-dihydroxylabda-8(17),11E-dien-16,15-olide (3), together with four known compounds, 19-hydroxylabda-8(17),13-dien-16,15-olide (4), 14-deoxy-11,12-didehydroandrographolide (5), 14-deoxyandrographolide, and pinusolidic acid, were isolated from the fruiting bodies of Antrodia camphorata. The structures of compounds 1-3 were elucidated by the analysis of their spectroscopic data. The in vitro neuroprotective activity of all compounds was evaluated, and compounds 1-5 protected neurons from Abeta damage by 39.2, 35.0, 36.7, 30.6, and 27.0%, respectively, at concentrations between 5 and 20 microM.