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Xiao-Yu Li

Publications and source records attributed to Xiao-Yu Li.

28 records · Page 2Linked to original sources
PubMed2003

Diterpenoid and phenolic glycosides from the roots of Rhododendron molle.

Two new grayanane diterpenoid glucosides, rhodomosides A (1), B (2) and two new phenolic glycosides 3, 4 together with a known glucosyringic acid (5) were isolated from the roots of Rhododendron molle G. Don (Ericaceae). Their structures were elucidated on the basis of spectral analysis. Compounds 3, 4 and 5 were found to inhibit the proliferation of murine B lymphocytes in vitro, while compound 3 also showed stimulatory activity on the proliferation of murine T lymphocytes in vitro.

Animals↗
PubMed2003

Analysis of triptolide-regulated gene expression in Jurkat cells by complementary DNA microarray.

AIM: To investigate the global gene expression profile changes in Jurkat cells after triptolide treatment in order to find the possible triptolide targets. METHODS: Jurkat cells were treated with or without triptolide 10 microg/L for 2 h. Total RNA were isolated and used as templates for reverse transcriptional labeling of fluorescent cDNA probes. High density DNA microarray chips with a set of 13,872 human genes/Ests were used to generate the expression profile of triptolide-treated or untreated control Jurkat cells by hybridizing with fluorescent labeled probes. Array image was acquired and analyzed with array analyzing software GeneSpring. RESULTS: Triptolide significantly suppressed expression of 117 genes in Jurkat cells. Among these 117 genes, 30 % were Ests or genes without known functions, 13 % were transcription factors, 9 % were signal transduction pathway regulators, and 9 % were DNA binding proteins. Notably, the expression of mitogen-activated protein kinase kinase kinase kinase 5 (MAP kinase 5) and phosphoinositide-3-kinase (PI-3 kinase) was inhibited more than 100-fold. Moreover, the expression of genes involved in lipid transportation and metabolism was down-regulated by triptolide. CONCLUSION: High-density microarray provided an effective approach to identify drug targeting molecules. It is suggested that the widely known immune suppressive and antitumor effects of triptolide were mediated at least in part by suppression of MAP kinase and PI-3 kinase gene expression.

Antineoplastic Agents, Phytogenic↗
PubMed2002

Structural features of immunologically active polysaccharides from Ganoderma lucidum.

Three polysaccharides, two heteroglycans (PL-1 and PL-4) and one glucan (PL-3), were solubilized from the fruit bodies of Ganoderma lucidum and isolated by anion-exchange and gel-filtration chromatography. Their structural features were elucidated by glycosyl residue and glycosyl linkage composition analyses, partial acid hydrolysis, acetolysis, periodate oxidation, 1D and 2D NMR spectroscopy, and ESI-MS experiments. The data obtained indicated that PL-1 had a backbone consisting of 1,4-linked alpha-D-glucopyranosyl residues and 1,6-linked beta-D-galactopyranosyl residues with branches at O-6 of glucose residues and O-2 of galactose residues, composed of terminal glucose, 1,6-linked glucosyl residues and terminal rhamnose. PL-3 was a highly branched glucan composed of 1,3-linked beta-D-glucopyranosyl residues substituted at O-6 with 1,6-linked glucosyl residues. PL-4 was comprised of 1,3-, 1,4-, 1,6-linked beta-D-glucopyranosyl residues and 1,6-linked beta-D-mannopyranosyl residues. These polysaccharides enhanced the proliferation of T- and B-lymphocytes in vitro to varying contents and PL-1 exhibited an immune-stimulating activity in mice.

Adjuvants, Immunologic↗
PubMed2002

Alkaloids from Menispermum dauricum.

The alkaloids, dechloroacutumidine and 1-epidechloroacutumine, together with three known alkaloids, acutumidine, acutumine, and dechloroacutumine, were isolated from the rhizomes of Menispermum dauricum and their structures established by spectral and chemical methods. The cytotoxicity of each compound against the growth of human cell lines was studied, and acutumine selectively inhibited T-cell growth.

Alkaloids↗
PubMed2002

Ginkgolide A, B, and huperzine A inhibit nitric oxide-induced neurotoxicity.

Nitric oxide (NO) is believed to play important roles in neuronal degeneration. In this study, the effects of NO on cell growth and apoptosis have been examined in human neuroblastoma cell line SK-N-SH. Sodium nitroprusside (SNP), a NO donor, was found to significantly inhibit cell growth and to induce apoptosis. The inhibitory and apoptotic activities of SNP followed a dose- and time-dependent manner. Ginkgolide A, B (GA, B), and huperzine A (Hup A), the three compounds isolated from Chinese herbs, blocked the inhibition of cell growth and apoptosis induced by SNP. The results suggest that inhibition of NO-induced neurotoxicity may be one mechanism of the above three therapeutic agents in neurodegenerative diseases.

Alkaloids↗
PubMed2002

Structural characterization and biological activities of SC4, an acidic polysaccharide from Salvia chinensis.

AIM: To study the chemical characterization and some biological activities of an acidic polysaccharide, named SC4 from Salvia chinensis. METHODS: Chemical and spectral methods were employed to identify the structural characterization of SC4. Effect of SC4 on the proliferation of T- and B-lymphocytes both in vivo and in vitro was measured at various concentrations, and the protective effects of SC4 on PC12 cells against H2O2-induced injury was observed. RESULTS: SC4 was a highly branched polysaccharide with mean molecular weight of 4.5 10(5), composed of Rha, Xyl, Ser, Gal, and GalA in the molar ratio of 1.0 7.0 5.3 1.2 4.2. Methylation analysis and NMR identified the linkages of the residues of SC4. SC4 increased the B-lymphocyte proliferation and spleen weight remarkably while no obvious changes were examined in T-lymphocyte proliferation, thymus weight, and the level of IgG and C3 in blood of mice. Moreover, SC4 enhanced the PC12 cells viability after H2O2 treatment. CONCLUSION: SC4, the acidic polysaccharide with complicated structure, was a B-lymphocyte stimulator and protected PC12 cells at the concentration of 20 mg/L against H2O2-induced injury.

Adjuvants, Immunologic↗
PubMed2002

Effect of astragaloside IV on T, B lymphocyte proliferation and peritoneal macrophage function in mice.

AIM: To investigate the effect of astragaloside IV (ASI) on T, B lymphocyte proliferation, antibody production, and cytokines produced by murine peritoneal macrophages. METHODS: MTT assay was used to determine T, B lymphocyte proliferation and quantitative hemolysin spectrophotometry (QHS) assay was applied to test antibody production; IL-1 production was measured by thymocyte proliferation assay; TNF-alpha production was determined by the cytotoxicity assay against L929 cells. RESULTS: 1) In vivo, ASI 50-200 mg/kg ig for 7 d increased T lymphocyte proliferation and antibody production, and ASI 50-100 mg/kg ig for 7 d increased B lymphocyte proliferation but ASI 200 mg/kg had no effect on B lymphocyte proliferation; 2) In vitro, ASI increased T, B lymphocyte proliferation only at 100 nmol/L; 3) ASI increased IL-1 activity at 1 nmol/L in vitro, but decreased it at 100 and 1000 nmol/L; 4) ASI inhibited TNF-alpha activity with or without LPS-stimulation in vitro. CONCLUSION: ASI increased T, B lymphocyte proliferation and antibody production in vivo and in vitro; but inhibited productions of IL-1 and TNF-alpha from peritoneal macrophages in vitro.

Animals↗
PubMed2002

Low dose of resveratrol enhanced immune response of mice.

AIM: To study the immune modulating effect of low dose of resveratrol. METHODS: Concanavalin A (ConA) and Staphylococcus aureus Cowan (Sac) were used to induce the activation of T lymphocyte and antigen presenting cell and cytokine production. [3H]-Thymidine incorporation was used to evaluate the proliferation of lymphocyte. Cytokine production was detected by ELISA method. Dinitrofluorobenzene (DNFB) was used to induce mice delayed type hypersensitivity (DTH, delayed hypersensitivity) response and ear swelling was used as an evaluating indicator. Changes of lymphocyte subtypes were detected by flow cytometry. RESULTS: Resveratrol (0.75-6 micromol/L) concentration-dependently promoted lymphocyte proliferation and IL-2 production induced by ConA. Sac induced IL-12 and IFN-gamma (interferon type II) production were also concentration-dependently enhanced by resveratrol, while IL-10 production was inhibited. Resveratrol (4 mg/kg, ig) promoted DTH response of mouse, which was suppressed by ethanol (16 %, w/v) consumption. Resveratrol treatment had no significant influence on lymphocyte subtypes in mice, however it could reverse the suppressive effect of ethanol both on macrophage percentage and on macrophage MHC-II molecule expression. CONCLUSION: Low dose resveratrol enhanced cell-mediate immune response. Promoting Th1 cytokine production and influencing on macrophage function might be its mechanisms.

Adjuvants, Immunologic↗
PubMed2002

Effects of resveratrol and ethanol on production of pro-inflammatory factors from endotoxin activated murine macrophages.

AIM: To study the interaction of resveratrol and ethanol on the production of pro-inflammatory factors from activated murine peritoneal macrophages (MPM). METHODS: NO production was measured with Griess assay; IL-1 production was measured through thymocyte co-stimulating assay; IL-6 and TNF-alpha were detected by ELISA method. RESULTS: Resveratrol (6.25, 12.5, 25 micromol/L) and ethanol (0.2 %, 0.8 %) synergistically inhibited the 24 h production of NO from lipopolysaccharide (LPS, 1 mg/L) and IFN-gamma (5 kU/L) stimulated MPM; resveratrol at higher dose (25 micromol/L) also inhibited IL-6 production. Ethanol additively strengthened this effect. Ethanol had no significant influence on 24 h MPM IL-1 production, but it promoted the ability of resveratrol on enhancing the IL-1 release from activated MPM. Low doses of ethanol inhibited 24 h production of TNF-alpha, however, both dose of ethanol enhanced the promoting effect of resveratrol on TNF-alpha production. CONCLUSION: Resveratrol and ethanol can interact to influence the production of macrophage function molecules, which is noteworthy in evaluating the health-care effect of wine consumption.

Animals↗