Airong Song

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-1β, 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-1β, 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 β-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 β-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 (CCl4)-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% CCl4 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 CCl4-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 CCl4-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.