Two new quinoline alkaloid with neuroprotective activities from Xylaria longipes.

Two new quinoline alkaloids with an α, ß-unsaturated amide side chain, xylarinines A and B (1 and 2), were isolated from the ethyl acetate extracts of Xylaria longipes solid fermentation. The structures of these were primarily determined though NMR and HRESIMS data analysis. The absolute configuration of compound 1 was assigned using experimental and calculated ECD data. The neuroprotective effects of compounds 1 and 2 against glutamate-induced damage in PC12 cells were evaluated in vitro bioassay. The results demonstrated that both compounds significantly improved cell viability, inhibited apoptosis, decreased malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) and glutathione (GSH) levels, and reduced intracellular reactive oxygen species (ROS) accumulation. These findings suggested that these mechanisms contribute to the neuroprotective effects of the compounds.

A pair of new chromone enantiomers from Xylaria nigripes.

A pair of new chromone derivative enantiomers, (+)-xylarichromone A (1a) and (-)-xylarichromone A (1b), were isolated from the solid fermentation of Xylaria nigripes. The planar structure of 1 was determined by extensive NMR spectroscopic data, and its absolute configuration was assigned by comparison the ECD spectra with the known chromone derivatives. Compound 1 was the first chromone derivative reported from this medicinal fungus. The neuroprotective effects of 1 against oxygen and glucose deprivation (OGD) induced pheochromocytoma-12 cells (PC12) injury was investigated.

Neuroprotective methylsuccinic acid and enoic acid derivatives from the fungus Xylaria longipes.

Three undescribed methylsuccinic acid derivatives, xylaril acids A-C, and two undescribed enoic acid derivatives, xylaril acids D-E, were isolated from the fungus Xylaria longipes. The structures of the undescribed compounds were deduced by spectroscopic means, including HRESIMS and 1D/2D NMR spectroscopy, as well as ECD calculations. The absolute configuration of xylaril acids A was further determined by single-crystal X-ray diffraction experiments. All the isolated compounds displayed neuroprotective activities against oxygen-glucose deprivation/reperfusion injury in PC12 cells by enhancing cell viability and inhibiting cell apoptosis.

Two New Compounds from the Fungus Xylaria nigripes.

In the process of discovering more neural-system-related bioactive compounds from Xylaria nigripes, xylariamino acid A (1), a new amino acid derivative, and a new isovaleric acid phenethyl ester (2) were isolated and identified. Their structures and absolute configurations were determined by analyses of IR, HRESIMS, NMR spectroscopic data, and gauge-independent atomic orbital (GIAO) NMR calculation, as well as electronic circular dichroism (ECD) calculation. The isolated compounds were evaluated for their neuroprotective effects against damage to PC12 cells by oxygen and glucose deprivation (OGD). Compounds 1 and 2 can increase the viability of OGD-induced PC12 cells at all tested concentrations. Moreover, compound 2 (1 µmol L-1) can significantly reduce the percentage of apoptotic cells.

Four new resorcinol derivatives with neuroprotective activities from Xylaria nigripes.

Four new resorcinol derivatives, namely (-)/(+)-xylarinig A (1), as well as xylarinigs B (2) and C (3), were isolated from the ethyl acetate extracts of the solid fermentation of Xylaria nigripes. Their structures were established by comprehensive spectroscopic analysis combined with electronic circular dichroism (ECD) calculations. Compound 1 is an optical mixture, and was resoluted into optical pure enatiomers (+)-1 and (-)-1 by chiral HPLC. The neuroprotective effects of 1-3 against the damage of PC12 cells induced by oxygen and glucose deprivation (OGD) were evaluated.

Synergistic anti-inflammatory effects of different polysaccharide components from Xylaria nigripes.

Nondigestible polysaccharides are essential nutrients, which are also important bioactive constituents of mushrooms. This study aimed to investigate the physicochemical properties and anti-inflammatory effects of different polysaccharide components of Xylaria nigripes in lipopolysaccharides (LPS)-induced RAW264.7 macrophages. Results showed that X. nigripes nondigestible polysaccharide (XN) possessed a molecular weight of 910.7 kDa and mainly composed of glucose; it effectively suppressed NO, TNF-α, and IL-6 production. Based on molecular weight, two bioactive polysaccharide components (F1 and F2) were isolated from XN. F1 was a glucan with high molecular weight (885.2 kDa), whereas F2 was a low molecular weight heteropolysaccharide (24.5 kDa) composing of glucose, mannose, and galactose. F1 showed stronger inhibitory effects on NO, TNF-α, and IL-6 production than F2, however, its inhibitory effects were weaker than XN. Further analysis demonstrated that the combined treatment of F1 and F2 exhibited anti-inflammatory activity as good as XN, and they possessed synergistic effects on inhibiting pro-inflammatory mediator production. PRACTICAL APPLICATIONS: Polysaccharides are essential nutrients, and are major bioactive constituents of mushrooms. This study isolated two bioactive polysaccharide components from Xylaria nigripes, namely F1 and F2. F1 was a high molecular weight glucan, whereas F2 was a low molecular weight heteropolysaccharide. F1 showed stronger anti-inflammatory activity than F2, but was weaker than their combined treatment (F1 + F2). Different polysaccharide components were shown to possess synergistic anti-inflammatory effects, suggesting their importance in the formulation of polysaccharide-based products.

Xylarinaps A-E, five pairs of naphthalenone derivatives with neuroprotective activities from Xylaria nigripes.

Five pairs of undescribed naphthalenone derivative enantiomers, xylarinaps A-E, including one pair of indole naphthalenones and four pairs of naphthalene-naphthalenone dimers, were isolated from the ethyl acetate extracts of the solid fermentation of Xylaria nigripes, which has been used as a traditional Chinese medicinal fungus for the treatment of insomnia, trauma, and depression. The structures of these enantiomers were elucidated based on comprehensive spectroscopic analysis, including NMR and HRESIMS. Their absolute configurations were assigned by the experimental and calculated ECD data. The neuroprotective effects of all the compounds against damage to PC12 cells by oxygen and glucose deprivation (OGD) were evaluated by an in vitro bioassay. The results revealed that xylarinaps A, B, D, and E significantly enhanced cell viability, decreased the levels of malondialdehyde (MDA), increased the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as further markedly inhibiting apoptosis, which indicated that these results could be the mode of action of their neuroprotective effect.

Differences in water soluble non-digestible polysaccharides and anti-inflammatory activities of fruiting bodies from two cultivated Xylaria nigripes strains.

Polysaccharides including ß-glucans are important bioactive components of mushroom. Xylaria nigripes is a popular medicinal fungus that has been used for treating trauma, insomnia and mental illness. This study examined the physicochemical characteristics and anti-inflammatory activities of water soluble non-digestible polysaccharides (TXNP and CXNP) from fruiting bodies of two cultivated X. nigripes strains (TXN and CXN). Results showed that both TXNP and CXNP possessed relatively similar FT-IR spectra. TXNP had a triple helix conformation and molecular weight of 853.8 kDa, whereas the molecular weight of CXNP was 14.7 kDa. The monosaccharide composition of TXNP was predominantly glucose, whereas CXNP contained xylose, mannose and glucose. Although both TXNP and CXNP dose-dependently suppressed the production of NO, IL-1ß, TNF-α and PGE2, as well as the expression of iNOS, COX-2 and NF-κB in the lipopolysaccharide-induced RAW264.7 macrophages, the potency of TXNP was stronger. This study reveals that under similar conditions of cultivation and extraction procedures, the different physicochemical characteristics of polysaccharides from TXN and CXN may have contributed to the differences in their anti-inflammatory potency.

Protective effect of medicinal fungus Xylaria nigripes mycelia extracts against hydrogen peroxide-induced apoptosis in PC12 cells.

Xylaria nigripes ( XN) is a medicinal fungus that was used traditionally as a diuretic, nerve tonic, and for treating insomnia and trauma. In this study, we elucidated possible mechanisms of neuroprotective effects of XN mycelia extracts. XN mycelia were produced by fermentation. Hot water extract and 70% ethanol extract of XN mycelia were evaluated on hydrogen peroxide (H2O2)-induced apoptosis in PC12, a rat pheochromocytoma cell line. Both XN extracts effectively protected PC12 cells against H2O2-induced cell damage by inhibiting release of lactate dehydrogenase, decreasing DNA damage, restoring mitochondrial membrane potential, and arresting abnormal apoptosis through upregulation of Bcl-2 and downregulation of Bax and caspase 3. Compared to water extract, ethanol extract showed not only greater neuroprotective effects but also a higher antioxidant activity by scavenging DPPH radicals, inhibiting lipid peroxidation, and reducing power. High phenolic content and antioxidant activity may provide the neuroprotective properties of XN ethanol extract.

Three New Ergot Alkaloids from the Fruiting Bodies of Xylaria nigripes (Kl.) Sacc.

Three new ergot alkaloids, xylanigripones A - C (1 - 3) together with three known compounds, agroclavine (4), 8,9-didehydro-10-hydroxy-6,8-dimethylergolin (5), and (6S)-agroclavine N-oxide (6) were isolated from the fungus Xylaria nigripes (Kl.) Sacc. Their structures were elucidated by comprehensive spectroscopic analyses and high-resolution mass spectrometry as well as by comparison with the literature. The absolute configuration was determined by Density Functional Theory (DFT) calculation methods. In addition, all of the compounds were evaluated for bioactivity via a cytotoxicity assay, an acetylcholinesterase inhibition assay and a cholesterol ester transfer protein inhibition assay.

The anti-depression effect of Xylaria nigripes in patients with epilepsy: A multicenter randomized double-blind study.

PURPOSE: The comorbidity of depression in patients with epilepsy is common and treatment is still controversial. This pilot study was aimed at evaluating the efficacy and safety of Xylaria nigripes for treating depressive symptoms in patients with epilepsy during 12 weeks of treatment. METHODS: A multicenter, double-blind, placebo-controlled, randomized superiority study was performed. A total of 104 patients with epilepsy who fulfilled the study criteria were randomized 1:1 to receive Xylaria nigripes (the Wu Ling group) or placebo (the placebo group) treatment in the 12-week period of study. The participants were visited on weeks 0, 2, 4, 8, and 12 of the treatment course. RESULTS: Eighty-one patients finished all of the visits. The primary efficacy endpoint in this study was the total effective rate for depression, which was significantly greater in the Wu Ling group (51.3%, n=39) than in the placebo group (35.7%, n=42, 0.51-0.36=0.15, 95% CI -0.06 to 0.37, U=2.83, P=0.002) after 12 weeks of treatment. No differences in seizure frequency or changes in severity were found between the Wu Ling and the placebo groups. In addition, the quality of life and seizure worry subscale scores in patients with epilepsy were also improved more notably in the Wu Ling group than in the placebo group (P<0.05). Most of the adverse effects (AEs) in this study were mild and had no differences between the Wu Ling and the placebo groups. CONCLUSION: Xylaria nigripes could alleviate depressive symptoms within 12 weeks treatment and was well tolerated in patients with epilepsy.

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.

Xylaria nigripes mitigates spatial memory impairment induced by rapid eye movement sleep deprivation.

We aimed to investigate the effects of Xylaria nigripes (XN) extracts on the rapid eye movement sleep deprivation (REMSD)-induced memory impairment, and explore related mechanism. Male Sprague Dawley rats were randomly divided into 6 groups: cage control (CC)-NaCl group; tank control (TC)-NaCl group; sleep deprivation (SD)-NaCl group; CC-XN group; TC-XN group and SD-XN group. The rats were administered with intragastric XN and 0.9% of sodium chloride. SD group rats were deprived of REM sleep for 72 h. Morris water maze (MWM) was used to assess the effects of XN on spatial learning and memory. The expression of cAMP-response element binding protein (CREB) and p-CREB were also investigated in all groups. Result showed rats in SD-NaCl group had significantly longer mean escape latencies in finding the platform as compared to the control rats (p<0.05) in MWM test. The SD-NaCl group spent significantly less time in goal quadrant compared with the SD-XN group. REMSD and XN did not alter CREB expression in the hippocampus, while sleep deprivation resulted in reduced phosphorylation of CREB in the hippocampus, which was reversed by XN. XN mitigates spatial memory impairment induced by REMSD in rat. Phosphorylation of CREB in hippocampus might be one of the mechanisms.