Polysaccharide Isolated from Zizyphus jujuba ( Hóng Zǎo) Inhibits Interleukin-2 Production in Jurkat T Cells.

Zizyphus jujuba ( Hóng Zǎo), a traditional Chinese herb widely used in many Asian countries, has been shown to possess vital biological activities such as anti-cancer activity. The objective of this study was to evaluate the immunomodulatory effect of deproteinated polysaccharide (DP) isolated from Z. jujuba. The DP isolated from Z. jujuba consisted of two polysaccharide fractions and their molecular weights (MWs) were found to be 143,108 and 67,633 Da, respectively. The DP could significantly decrease interleukin (IL)-2 production in phytohemagglutinin (PHA)-activated Jurkat T cells in a dose-dependent manner after 48 h of incubation, with the inhibition being 47.5%, 61.2%, and 81.7% for DP concentrations of 0.75, 1.75, and 2.5 mg/ml, respectively. Thus, our study showed that DP isolated from Z. jujuba may possess anti-inflammatory activity as it could significantly reduce IL-2 production in activated Jurkat T cells.

4-Hydroxy-17-methylincisterol from Agaricus blazei Decreased Cytokine Production and Cell Proliferation in Human Peripheral Blood Mononuclear Cells via Inhibition of NF-AT and NF-κB Activation.

Agaricus blazei Murill is an edible and medicinal mushroom. In the previous study, we have proved that extracts of A. blazei inhibit human peripheral blood mononuclear cell (PBMC) proliferation activated with phytohemagglutinin (PHA). Currently, we purified 4-hydroxy-17-methylincisterol (4-HM; C21H33O3) from A. blazei investigated its regulatory effects on cytokine productions and cell proliferation of PBMC induced by PHA. The results indicated that 4-HM suppressed, in activated PBMC, the production and mRNA expression of interleukin-2 (IL-2), IL-4, tumor necrosis factor- α , and interferon- γ in a concentration-dependent manner. This inhibition was not related to cell viability. While 4-HM did not affect ERK phosphorylation and its downstream c-fos gene expression in PBMC induced by PHA, it decreased both NF-AT and NF- κ B activation. The upstream signaling of NF-AT and NF- κ B, intracellular calcium concentrations ([Ca(2+)]i), and protein kinase C theta (PKC θ ) activation in PHA-treated PBMC were reduced by 4-HM. The data demonstrated that the suppressant effects of 4-HM on cell proliferation in PBMC activated by PHA appeared to be mediated, at least in part, through inhibition of Ca(2+) mobilization and PKC θ activation, NF-AT and NF- κ B activation, and cytokine transcripts and productions of PBMC. We suggested that A. blazei contained a potential immunomodulator 4-HM.

HTDP-2, a new synthetic compound, inhibits glutamate release through reduction of voltage-dependent Ca²âº influx in rat cerebral cortex nerve terminals.

AIM: The present study was aimed at investigating the effect of trans-6-(4-chlorobutyl)-5-hydroxy-4-(phenylthio)-1-tosyl-5,6-dihydropyridine-2(1H)-one (HTDP-2), a novel synthetic compound, on the release of endogenous glutamate in rat cerebrocortical nerve terminals (synaptosomes) and exploring the possible mechanism. METHODS: The release of glutamate was evoked by the K⁺ channel blocker 4-aminopyridine (4-AP) and measured by an on-line enzyme-coupled fluorimetric assay. We also used a membrane potential-sensitive dye to assay nerve terminal excitability and depolarization, and a Ca²âº indicator, Fura-2-acetoxymethyl ester, to monitor cytosolic Ca²âº concentrations ([Ca²âº](c)). RESULTS: HTDP-2 inhibited the release of glutamate evoked by 4-AP in a concentration-dependent manner. Inhibition of glutamate release by HTDP-2 was prevented by the chelating intraterminal Ca²âº ions, and by the vesicular transporter inhibitor bafilomycin A1, but was insensitive to the glutamate transporter inhibitor DL-threo-ß-benzyloxyaspartate. HTDP-2 did not alter the resting synaptosomal membrane potential or 4-AP-mediated depolarization whereas it decreased the 4-AP-induced increase in [Ca²âº](c). Furthermore, the inhibitory effect of HTDP-2 on the evoked glutamate release was abolished by the N-, and P/Q-type Ca²âº channel blocker ω-conotoxin MVIIC, but not by the ryanodine receptor blocker dantrolene, or the mitochondrial Na⁺/Ca²âº exchanger blocker CGP37157. CONCLUSION: Based on these results, we suggest that, in rat cerebrocortical nerve terminals, HTDP-2 decreases voltage-dependent Ca²âº channel activity and, in so doing, inhibits the evoked glutamate release.

Chemical constituents from Lobelia chinensis and their anti-virus and anti-inflammatory bioactivities.

In total, forty six compounds, including the novel compound lobechine (1), were characterized from the methanol extracts of Lobelia chinensis. The chemical structures of known metabolites were identified by comparing their spectroscopic and physical data with compounds reported in the literature. The structure of lobechine (1) was comprehensively established with the aid of 1D and 2D NMR spectroscopic analyses. In addition, selected isolates were screened for their inhibition of HSV-1 replication, superoxide anion generation, and elastase release. Among the tested compounds, scoparone (10) exhibited significant inhibition of superoxide anion generation with IC(50) of 6.14 ± 1.97 µM and lobechine (1) exhibited moderate inhibition of elastase release with IC(50) of 25.01 ± 6.95 µM, respectively.

Arctigenin from Arctium lappa inhibits interleukin-2 and interferon gene expression in primary human T lymphocytes.

BACKGROUND: Arctium lappa (Niubang), a Chinese herbal medicine, is used to treat tissue inflammation. This study investigates the effects of arctigenin (AC), isolated from A. lappa, on anti-CD3/CD28 Ab-stimulated cell proliferation and cytokine gene expression in primary human T lymphocytes. METHODS: Cell proliferation was determined with enzyme immunoassays and the tritiated thymidine uptake method. Cytokine production and gene expression were analyzed with reverse transcription-polymerase chain reaction. RESULTS: AC inhibited primary human T lymphocytes proliferation activated by anti-CD3/CD28 Ab. Cell viability test indicated that the inhibitory effects of AC on primary human T lymphocyte proliferation were not due to direct cytotoxicity. AC suppressed interleukin-2 (IL-2) and interferon-γ (IFN-γ) production in a concentration-dependent manner. Furthermore, AC decreased the IL-2 and IFN-γ gene expression in primary human T lymphocytes induced by anti-CD3/CD28 Ab. Reporter gene analyses revealed that AC decreased NF-AT-mediated reporter gene expression. CONCLUSION: AC inhibited T lymphocyte proliferation and decreased the gene expression of IL-2, IFN-γ and NF-AT.

(S)-armepavine from Chinese medicine improves experimental autoimmune crescentic glomerulonephritis.

OBJECTIVE: Intra-renal T cells and macrophages play a key pathogenic role in the development and progression of glomerular crescents. We aimed to establish (S)-armepavine [(S)-ARM], a major bioactive compound of a Chinese medicinal plant, Nelumbo nucifera, as a potential therapeutic agent in the treatment of autoimmune crescentic glomerulonephritis (ACGN). METHODS: A mouse ACGN model associated with T-cell dysregulation, was used to evaluate the therapeutic effects of (S)-ARM on the rapidly progressive glomerular disorder. RESULTS: The results showed that (S)-ARM administered in the established phase of ACGN is capable of dramatically decreasing glomerular crescents in the kidney and improving proteinuria and renal dysfunction. These effects were associated with greatly inhibited infiltration of T cells/macrophages and suppressed nuclear factor (NF)-κB activation in the kidney, lowered serum levels of autoantibodies and both serum and intra-renal levels of pro-inflammatory cytokines, suppressed T/B-cell activation and T-cell proliferation of the spleen, reduced glomerular immune deposits and apoptosis in both the spleen and kidney in (S)-ARM-treated ACGN mice, compared with the vehicle-treated (disease control) group of ACGN mice. CONCLUSION: We demonstrated therapeutic effects of (S)-ARM on ACGN as a result of: (i) early systemic negative modulation of T/B cells; (ii) intra-renal regulation of combined NF-κB activation and mononuclear leucocytic infiltration, thereby preventing glomerular crescent formation; and (iii) protection from apoptosis in both the spleen and kidney.

Nortriterpene lactones from the fruits of Schisandra arisanensis.

Fractionation of an acetone extract from the fruits of Schisandra arisanensis afforded five new nortriterpene lactones, compounds 1-5, together with four known compounds, schindilactones D and E (6 and 7) and preschisanartanins A and B (8 and 9). Compound 1, a wuweiziartane-type nortriterpenoid, possesses a new type of fused ring system with a gamma-lactone ring between C-15 and C-17. Compounds 2, 6, and 7 may be categorized as schisanartane-type nortriterpenoids and compounds 3-5, 8, and 9 as preschisanartane-type nortriterpenoids. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic data interpretation. The structure and relative configuration of 3 were supported by single-crystal X-ray diffraction analysis. The antiviral activity against HSV-1 and inhibitory effects on superoxide anion generation and elastase release by human neutrophils in response to FMLP/CB of compounds 1-9 were evaluated.

The isolated and combined effects of folic acid and synthetic bioactive compounds against Abeta(25-35)-induced toxicity in human microglial cells.

Folic acid plays an important role in neuronal development. A series of newly synthesized bioactive compounds (NSCs) was reported to exhibit immunoactive and neuroprotective functions. The isolated and combined effects of folic acid and NSCs against beta-amyloid (Abeta)-induced cytotoxicity are poorly understood. These effects were tested using human microglia cells (C13NJ) subjected to Abeta(25-35) challenge. According to an MTT assay, treatment of C13NJ cells with Abeta(25-35) at 10-100 microM for 48 h induced 18%-43% cellular death in a dose-dependent manner (p < 0.05). Abeta(25-35) treatment at 25 microM induced nitrite oxide (NO) release, elevated superoxide production, and reduced the distribution of cells in the S phase. Preincubation of C13NJ with 100 microM folic acid protected against Abeta(25-35)-induced cell death, which coincided with a reduction in NO release by folic acid supplements. NSC47 at a level of 50 microM protected against Abeta(25-35)-induced cell death and reduced Abeta-promoted superoxide production (p < 0.05). Folic acid in combination with NSC47 at their cytoprotective doses did not synergistically ameliorate Abeta(25-35)-associated NO release, superoxide production, or cell cycle arrest. Taken together, folic acid or NSC treatment alone, but not the combined regimen, protected against Abeta(25-35)-induced cell death, which may partially, if not completely, be mediated by free radical-scavenging effects.

Flavanone and diphenylpropane glycosides and glycosidic acyl esters from Viscum articulatum.

Seven new compounds including three flavanone glycosides, visartisides A-C (1-3), three glycoside acyl esters, visartisides D-F (4-6), and one diphenylpropane glycoside, (4'-hydroxy-2',3',6',3''-tetramethoxy-1,3-diphenylpropane)-4''-O-beta-d-glucopyranoside (7), along with four known flavanone glycosides (8-11) were isolated from the leaves and stems of Viscum articulatum. The structure elucidation of 1-7 was based on spectroscopic data analysis. Biological evaluation showed that 1, 2, and 10 exhibited antioxidant activity using a DPPH method and that compounds 1, 3, and 11 were active in a lipopolysaccharide-induced nitric oxide assay.

Oxygenated lignans from the fruits of Schisandra arisanensis.

An acetone extract of the fruits of the Taiwanese medicinal plant Schisandra arisanensis has yielded 11 new oxygenated lignans. Four of these, named arisantetralones A-D (1-4), possess the aryltetralone skeleton, while the other seven, named arisanschinins F-L (5-11), are polyoxygenated C(18)-dibenzocyclooctadiene lignans. Structures were determined on the basis of spectroscopic analyses, especially 2D-NMR techniques. The structure of compound 1 was confirmed by X-ray crystallographic analysis. Immunomodulatory activity of the isolated lignans was tested and evaluated.

Isolation and immunomodulatory effect of homoisoflavones and flavones from Agave sisalana Perrine ex Engelm.

Three known flavones and seven known homoisoflavonoids were isolated from the methanolic extract of the leaves of Agave sisalanaPerrine ex Engelm. Their structures were elucidated on the basis of spectroscopic analysis. The isolated compounds were also evaluated for immunopharmacological activity. PBMC were used as target cells, and cell proliferation was determined by (3)H-thymidine uptake. (+/-)-3,9-Dihydroeucomin (4), dihydrobonducellin (5), and 5,7-dihydroxy-3-(4'-hydroxybenzyl)-4-chromanone (7) showed inhibitory effects on PBMC proliferation activated by PHA with IC(50) values 19.4, 73.8, and 58.8 microM, respectively. All three compounds significantly inhibited the production of IL-2 and IFN-gamma in activated PBMC in a concentration-dependent manner.

Efficacy of orally administered Lobelia chinensis extracts on herpes simplex virus type 1 infection in BALB/c mice.

By a plaque reduction assay, methanolic extracts from Lobelia chinensis (LC) significantly blocked herpes simplex virus type 1 (HSV-1) replication in HeLa cells without apparent cytotoxicity. The 50% inhibitory concentration (IC(50)) of LC on HSV-1 replication is 139.2 microg/ml. To elucidate LC anti-HSV-1 activity in vivo, BALB/c mice were injected subcutaneously with HSV-1 (2.5 x 10(6)PFU/50 microl), treated orally thrice a day with acyclovir (60 mg/kg/dose) or LC (20 and 50 mg/kg/dose) for 7 days, and inspected daily for signs of disease. Data from the scoring system indicated that animals infected with HSV-1, developed progressive zoster lesions starting 2 days postinfection (p.i.) and appeared the most serious syndromes at 4-5 days p.i. In marked contrast to the results with control mice, treatment with acyclovir or 50 mg/kg/dose LC resulted in a sustained protective effect. The HSV-1 titers and DNA levels in ground skin samples were significantly reduced by LC. No toxic effect of LC on liver and kidney functions was apparent. These results indicated that LC was a potent inhibitor of the in vitro and in vivo replication of HSV-1.

(S)-armepavine inhibits human peripheral blood mononuclear cell activation by regulating Itk and PLCgamma activation in a PI-3K-dependent manner.

Chinese herbs are useful edible and medicinal plants for their immune modulatory functions. We have proven that (S)-armepavine (C19H23O3N; MW313) from Nelumbo nucifera inhibits the proliferation of human PBMCs activated with PHA and improves autoimmune diseases in MRL/MpJ-lpr/lpr mice. In the present study, the pharmacological activities of (S)-armepavine were evaluated in PHA-activated PBMCs. The results showed that (S)-armepavine suppressed PHA-induced PBMC proliferation and genes expression of IL-2 and IFN-gamma without direct cytotoxicity. Inhibition of NF-AT and NF-kappaB activation suggested phospholipase Cgamma (PLCgamma)-mediated Ca2+ mobilization and protein kinase C activation were blocked by (S)-armepavine. Phosphorylation of PLCgamma is regulated by lymphocyte-specific kinase (Lck), ZAP-70, and IL-2-inducible T cell kinase (Itk). We found (S)-armepavine inhibited PHA-induced phosphorylation of Itk and PLCgamma efficiently but did not influence Lck or ZAP-70 phosphorylation. In addition, ZAP-70-mediated pathways, such as the association of linker for activation of T cells with PLCgamma and activation of ERK, were also intact in the presence of (S)-armepavine. Finally, reduction of phosphoinositide 3,4,5-trisphosphate formation and Akt phosphorylation suggested that (S)-armepavine inhibited Itk, and PLCgamma phosphorylation might be a result of the influence of PI-3K activation. Addition of exogenous IL-2 or PMA/A23187 rescued PBMC proliferation in the presence of (S)-armepavine. Therefore, we concluded that (S)-armepavine inhibited PHA-induced cell proliferation and cytokine production in a major way by blocking membrane-proximal effectors such as Itk and PLCgamma in a PI-3K-dependent manner.

Immunoactive polysaccharide-rich fractions from Panax notoginseng.

Panax notoginseng is a commonly used medicinal plant in south-western China. In a previous study, a sequential solubilisation of P. notoginseng high-molecular-weight (HMW) polymers using phenol-acetic acid-water, hot water, weak and strong alkali was performed to determine the structure of the component polysaccharides and proteins. The effects of these extracted HMW fractions on the human complement system, polymorphonuclear neutrophils (PMN) and peripheral blood mononuclear cells (PBMC) are reported here. Fr (1MKOH), which was extracted with 1 M KOH, showed the strongest complement-fixing activity and priming of reactive oxygen species (ROS) production by PMNs, as well as a mitogenic effect. Fr (1MKOH) was further fractionated by anion-exchange chromatography followed by gel-permeation chromatography. 1MD3-G2, the fraction most strongly bound to the DEAE anion-exchange column with a molecular weight of 1140 kDa, showed the highest complement-fixing activity. It is composed of acidic polysaccharides [including glucuronoarabinoxylan (GAX), homogalacturonan (HGA), rhamnogalacturonan I (RG I)], neutral polysaccharides (4-galactan and arabinan), and some protein.

Yatein from Chamaecyparis obtusa suppresses herpes simplex virus type 1 replication in HeLa cells by interruption the immediate-early gene expression.

Inhibitory effects of methanolic extracts from nine Chinese herbs on herpes simplex virus type 1 (HSV-1) replication were studied. By a bioassay-guided fractionation procedure, yatein (C(22)H(23)O(7); M.W.399) was isolated from Chamaecyparis obtusa; yatein significantly suppressed HSV-1 multiplication in HeLa cells without apparent cytotoxicity. To further localize the point in the HSV-1 replication cycle where arrest occurred, a set of key regulatory events leading to the viral multiplication was examined, including viral immediate-early (alpha) and late (gamma) gene expression and DNA replication. Results indicated that levels of glycoprotein B (gB) and gC mRNA expression in HeLa cells were impeded by yatein. Data from polymerase chain reaction showed that replication of HSV-1 DNA in HeLa cells was arrested by yatein. Furthermore, yatein decreased ICP0 and ICP4 gene expression in HeLa cells. Results of an electrophoretic mobility shift assay demonstrated that yatein interrupted the formation of alpha-trans-induction factor/C1/Oct-1/GARAT multiprotein complex. The mechanisms of antiviral action of yatein seem to be mediated, by inhibiting HSV-1 alpha gene expression, including expression of the ICP0 and ICP4 genes, and by arresting HSV-1 DNA synthesis and structural protein expression in HeLa cells. These results suggest that yatein is an antiviral agent against HSV-1 replication.

Inhibition of (S)-armepavine from Nelumbo nucifera on autoimmune disease of MRL/MpJ-lpr/lpr mice.

T cell immune responses play important roles in the pathogenesis of systemic lupus erythematosus (SLE). (S)-Armepavine (C19H23O3N; MW313) from Nelumbo nucifera suppresses T cells proliferation. To study its potential benefit on SLE, we examined effects of (S)-armepavine on MRL/MpJ-lpr/lpr mice, which have similar disease features to human SLE. MRL/MpJ-lpr/lpr mice were treated orally with (S)-armepavine for 6 weeks and their SLE characteristics were evaluated. The results revealed that (S)-armepavine prevented lymphadenopathy and elongated life span of MRL/MpJ-lpr/lpr mice. It seemed to be mediated by inhibition of splenocytes proliferation, suppression of interleukin-2 (IL-2), interleukin-4, interleukin-10, and interferon-gamma (IFN-gamma) gene expressions, reduction of glomerular hypercellularity and immune complexes deposition, and decrease of urinary protein and anti-double stranded DNA autoantibody production. Furthermore, the data demonstrated (S)-armepavine impaired IL-2 and IFN-gamma transcripts in human peripheral blood mononuclear cells. We suggest that (S)-armepavine may be an immunomodulator for the management of autoimmune diseases like SLE.

Herpes simplex virus type 1 propagation in HeLa cells interrupted by Nelumbo nucifera.

Inhibitory effects of ethanolic extracts from 10 Chinese herbs on herpes simplex virus type 1 (HSV-1) replication were investigated. By a bioassay-guided fractionation procedure, NN-B-5 was identified from seeds of N. nucifera. NN-B-5 significantly blocked HSV-1 multiplication in HeLa cells without apparent cytotoxicity. To elucidate the point in HSV-1 replication where arrest occurred, a set of key regulatory events leading to the viral multiplication was examined, including HSV-1 DNA synthesis and viral immediate early gene expressions. Data from polymerase chain reaction and Southern blotting showed that there were impairments of HSV-1 DNA replication in HeLa cells treated with NN-B-5. Results indicated that the production and mRNA transcription of infected cell protein (ICP) 0 and ICP4 were decreased in NN-B-5 treated HeLa cells. Results of an electrophoretic mobility shift assay demonstrated that NN-B-5 interrupted the formation of alpha-trans-induction factor/C1/Oct-1/GARAT multiprotein/DNA complexes. The mechanisms of antiviral action of NN-B-5 seem to be mediated, at least in part, through inhibition of immediate early transcripts, such as ICP0 and ICP4 mRNA and then blocking of all downstream viral products accumulation and progeny HSV-1 production.

Inhibitory effects of acylated kaempferol glycosides from the leaves of Cinnamomum kotoense on the proliferation of human peripheral blood mononuclear cells.

A new chemical entity, namely kaempferol 3- O-alpha-L-[2-(Z)-p-coumaroyl-4-(E)-p-coumaroyl]rhamnopyranoside (1), and the known kaempferol 3-O-alpha-L-[2,4-di-(E)-p-coumaroyl]rhamnopyranoside (2) have been isolated from the methanolic extract of leaves of Cinnamomum kotoense. Structural elucidation of compounds 1 and 2 were achieved on the basis of spectroscopic analysis. The effects of compounds 1 and 2 on phytohemagglutinin (PHA) stimulated cell proliferation were studied towards human peripheral blood mononuclear cells (PBMC). The results indicated that compounds 1 and 2 suppressed PBMC proliferation induced by PHA with an IC50 value of 5.0 +/- 1.3 and 6.0 +/- 1.5 microM, respectively. Interleukin-2 production in activated PBMC inhibited by compounds 1 and 2 were in a concentration-dependent manner. Therefore, we suggested that compounds 1 and 2 in C. kotoense were likely the growth modulators for PBMC.

Furocoumarin glycosides from the leaves of Ficus ruficaulis Merr. var. antaoensis.

From the methanolic extract of the leaves of Ficus ruficaulis Merr. var. antaoensis, 5-O-beta-D-glucopyranosyl-6-hydroxyangelicin (1), 6-O-beta-D-glucopyranosyl-5-hydroxyangelicin (2), 5,6-O-beta-D-diglucopyranosylangelicin (3), 8-O-beta-D-glucopyranosyl-5-hydroxypsoralen (4), 5-O-beta-D-glucopyranosyl-8-hydroxypsoralen (5), 3,4,5-trihydroxydehydro-alpha-ionol-9-O-beta-D-glucopyranoside (6), rutin (7), and isoquercitrin (8) were isolated. The structures of compounds 1-4 were elucidated by the analysis of their spectroscopic data. Their in vitro antiproliferation activities were also evaluated.

The extracts from Nelumbo Nucifera suppress cell cycle progression, cytokine genes expression, and cell proliferation in human peripheral blood mononuclear cells.

In the hope of identifying agents of therapeutic value in tissue inflammation, we tested ethanolic extracts of six Chinese herbs for their effects on human peripheral blood mononuclear cells (PBMC) proliferation in vitro. The results indicated that the extracts from Nelumbo nucifera Gaertn, used in treatment of tissue inflammation in traditional Chinese medicine, inhibited PBMC proliferation activated with phytohemagglutinin (PHA). By a bioassay-guided fractionation procedure, NN-B-4 identified from N. nucifera ethanolic extracts significantly suppressed activated PBMC proliferation. The inhibitory action of NN-B-4 did not involve direct cytotoxicity. In an attempt to further localize the point in the PBMC proliferation where arrest occurred, a set of key regulatory events leading to the cell proliferation, including cell cycle progression, production and gene expression of interleukin-2 (IL-2), IL-4, IL-10, and interferon-gamma (IFN-gamma) was examined. Cell cycle analysis indicated that NN-B-4 arrested the cell cycle progression of activated PBMC from the G1 transition to the S phase. The cyclin-dependent kinase (cdk) 4 mRNA expression in PBMC stimulated with PHA was reduced by NN-B-4. NN-B-4 suppressed, in activated PBMC, the production and mRNA expression of IL-2, IL-4, IL-10, and IFN-gamma in a dose-dependent fashion. The suppressant effects of NN-B-4 on proliferation of PBMC activated by PHA therefore appear to be mediated, at least in part, through inhibition of early transcripts of PBMC, especially those of important IL-2, IFN-gamma, and cdk4 and arrest of cell cycle progression in the cells.