Mono- and digalactosyldiacylglycerols: potent nitric oxide inhibitors from the marine microalga Nannochloropsis granulata

Chemical investigation of a marine microalga, Nannochloropsis granulata, led to the isolation of four digalactosyldiacylglycerols namely, (2S)-1-O-eicosapentaenoyl-2-O-palmitoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (1), (2S)-1-O-eicosapentaenoyl-2-O-palmitoleoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (2), (2S)-1-O-eicosapentaenoyl-2-O-myristoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (3), and (2S)-1,2-bis-O-eicosapentaenoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (4), together with their monogalactosyl analogs (5–8). Among the isolated galactolipids 2 and 3 were new natural products. Complete stereochemistry of 1, 4, 5, 7, and 8 was determined for the first time by both spectroscopic techniques and classical degradation methods. Both mono- and digalactosyldiacylglycerols isolated from N. granulata possessed strong nitric oxide (NO) inhibitory activity against lipopolysaccharide-induced NO production in RAW264.7 macrophage cells through downregulation of inducible nitric oxide synthase expression indicating the possible use as anti-inflammatory agents.     

New diacylglyceryltrimethylhomoserines from the marine microalga Nannochloropsis granulata and their nitric oxide inhibitory activity

Chemical investigation of polar lipids from the marine eustigmatophyte microalga Nannochloropsis granulata led to the isolation of six betaine lipid diacylglyceryltrimethylhomoserine (DGTS), namely, (2S)-1,2-bis-O-eicosapentaenoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (1), (2S)-1-O-eicosapentaenoyl-2-O-arachidonoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (2), (2S)-1-O-eicosapentaenoyl-2-O-myristoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (3), (2S)-1-O-eicosapentaenoyl-2-O-palmitoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (4), (2S)-1-O-eicosapentaenoyl-2-O-palmitoleoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (5), and (2S)-1-O-eicosapentaenoyl-2-O-linoleoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (6). Structures of the isolated DGTSs were elucidated based on both spectroscopic technique and degradation methods. This is the first report of isolation of 1 in pure state, and 2–6 are all new compounds. The isolated betaine lipids showed dose-dependent nitric oxide (NO) inhibitory activity against lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells. Further study suggested that these betaine lipids (1–6) inhibit NO production in RAW264.7 macrophage cells through downregulation of inducible nitric oxide synthase expression, indicating the possible use as an anti-inflammatory agent. This is the first report of DGTS with anti-inflammatory activity.     

Isolation and antioxidant activity evaluation of two new phthalate derivatives from seahorse, Hippocampus Kuda Bleeler

Seahorse (Hippocampus Kuda Bleeler) has been used as traditional medicine for thousands of years, in Eastern Asia. In this study of the methanol extract of fresh Hippocampus Kuda, the new compounds 2-ethyldecyl 2-ethylundecyl phthalate (1), 2, 12-diethyl-11-methylhexadecyl 2-ethyl-11-methylhexadecylphthalate (2), along with a known Bis(2-ethylheptyl) phthalate (3) were isolated. They were tested for their antioxidant activities, including lipid peroxidation inhibitory activity, DPPH radical scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, alkyl radical scavenging, and cellular radicals; these can be detected using a fluorescence probe, 2??,7??-dichlorofluorescin diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS on mouse macrophages, RAW264.7 cell. Compound (2) exhibited the highest antioxidant activity and inhibitory intracellular ROS than another compounds (1, 3). Furthermore, MTT assay showed no cytotoxicity on mouse macrophages cell (RAW264.7) and human fetal lung fibroblast cell line (MRC-5). This antioxidant property depends on concentration and increasing with increased amount of the compound.     

Five new galactolipids from the freshwater microalga Porphyridium aerugineum and their nitric oxide inhibitory activity

Chemical investigation of the freshwater rhodophyte microalga Porphyridium aerugineum led to the isolation of five new galactolipids, namely, (2S)-1-O-eicosapentaenoyl-2-O-arachidonoyl-3-O-β-d-galactopyranosylglycerol (1), (2S)-1-O-eicosapentaenoyl-2-O-linoleoyl-3-O-β-d-galactopyranosylglycerol (2), (2S)-1-O-arachidoyl-2-O-palmitoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (6), (2S)-1-O-eicosapentaenoyl-2-O-arachidoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (7), and (2S)-1-O-eicosapentaenoyl-2-O-linoleoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (8) together with five known galactolipids. The stereo-structures of all new galactolipids were elucidated by spectroscopic analyses and both enzymatic and chemical degradation methods. This is the first report of galactolipids from P. aerugineum. The newly isolated galactolipids showed strong and dose-dependent nitric oxide (NO) inhibitory activity against lipopolysaccharide-induced NO production in RAW264.7 macrophage cells. Both galactolipids 1 and 2 possessed stronger NO inhibitory activity than N ^G-methyl-l-arginine acetate salt, a well-known NO inhibitor used as a positive control. Further study suggested that these galactolipids inhibit NO production through downregulation of inducible nitric oxide synthase expression.     

Two dimeric lignans with an unusual α,β-unsaturated ketone motif from Zanthoxylum podocarpum and their inhibitory effects on nitric oxide production

Two new dimeric lignans, zanthpodocarpins A (1) and B (2), and five known lignans, eudesmin (3), (1R,2R,5R,6S)-2-(3,4-dimethoxyphenyl)-6-(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (4), dimethoxysamin (5), rel-(1R,5R,6S)-6-(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclo[3.3.0]octan-2-one (6), and magnone A (7), were isolated from the barks of Zanthoxylum podocarpum. Their structures were identified by using spectroscopic methods. Compounds 1 and 2 are rare dilignans bearing an unusual α,β-unsaturated ketone group from a natural source. Bioassay showed that compounds 1 and 2 could inhibit nitric oxide (NO) production in LPS stimulated RAW 264.7 cells with IC₅₀ values of 5.31 μM and 12.15 μM, respectively.     

Lipids isolated from the cultivated red alga Chondrus crispus inhibit nitric oxide production

A MeOH extract of cultivated Chondrus crispus showed dose-dependent nitric oxide (NO) inhibition of lipopolysaccharide-induced NO production in macrophage RAW264.7 cells. NO inhibition-guided fractionation of the extract led to identification of eicosapentaenoic acid (EPA, 1), arachidonic acid (AA, 2), lutein (3), and eight galactolipids as active components. Based on spectral analysis, the isolated galactolipids were identified as (2S)-1,2-bis-O-eicosapentaenoyl-3-O-β-d-galactopyranosylglycerol (4), (2S)-1-O-eicosapentaenoyl-2-O-arachidonoyl-3-O-β-d-galactopyranosylglycerol (5), (2S)-1-O-(6Z,9Z,12Z,15Z-octadecatetranoyl)-2-O-palmitoyl-3-O-β-d-galactopyranosylglycerol (6), (2S)-1-O-eicosapentaenoyl-2-O-palmitoyl-3-O-β-d-galactopyranosylglycerol (7), (2S)-1,2-bis-O-arachidonoyl-3-O-β-d-galactopyranosylglycerol (8), (2S)-1-O-arachidonoyl-2-O-palmitoyl-3-O-β-d-galactopyranosylglycerol (9), (2S)-1-O-eicosapentaenoyl-2-O-palmitoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (10), and (2S)-1-O-arachidonoyl-2-O-palmitoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (11). All the isolated compounds showed significant NO inhibitory activity. This is the first report of the isolation and identification of individual galactolipids from C. crispus. Moreover, (2S)-1,2-bis-O-arachidonoyl ?3-O-β-d-galactopyranosylglycerol (8) is a novel compound.     

Lactones from the pericarps of Litsea japonica and their anti-inflammatory activities

Five new lactones, litsenolide F₁ (1), lisealactone H₁ (10), lisealactone H₂ (11), akolactone D (13), and akolactone E (14), along with thirteen known compounds were isolated from the pericarps of Litsea japonica (Thunb.) Jussieu. Their chemical structures were elucidated by extensive spectroscopic analyses, including 1D and 2D NMR, HRMS, and chemical methods. The isolated compounds were evaluated for their inhibitory effects on NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Among them, 2-alkylidene-3-hydroxy-4-methylbutanolide derivatives (compounds 1–9) exhibited the most potent activity, with IC₅₀ values in the range of 2.9–12.8?μM. In additon, compounds 1, 3, 4, and 6 showed inhibition of iNOS and COX-2 expression in concentration-dependent manner. Compound 3 suppresses mRNA expression of iNOS, COX-2, IL-6, and TNF-α in LPS-stimulated RAW264.7 cells. Based on these evidence, the isolated lactones from L. japonica could be promissing candidates for the development of new anti-inflammatory agents.     

Tanzawaic acid derivatives from a marine isolate of Penicillium sp. (SF-6013) with anti-inflammatory and PTP1B inhibitory activities

Chemical investigation of a marine-derived fungus Penicillium sp. SF-6013 resulted in the discovery of a new tanzawaic acid derivative, 2E,4Z-tanzawaic acid D (1), together with four known analogues, tanzawaic acids A (2) and D (3), a salt form of tanzawaic acid E (4), and tanzawaic acid B (5). Their structures were mainly determined by analysis of NMR and MS data, along with chemical methods. Preliminary screening for anti-inflammatory effects in lipopolysaccharide (LPS)-activated microglial BV-2 cells showed that compounds 1, 2, and 5 inhibited the production of nitric oxide (NO) with IC₅₀ values of 37.8, 7.1, and 42.5 μM, respectively. Compound 2 also inhibited NO production in LPS-stimulated RAW264.7 murine macrophages with an IC₅₀ value of 27.0 μM. Moreover, these inhibitory effects correlated with the suppressive effect of compound 2 on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW264.7 and BV2 cells. In addition, compounds 2 and 5 significantly inhibited the activity of protein tyrosine phosphatase 1B (PTP1B) with the same IC₅₀ value (8.2 μM).     

Inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells by lignans isolated from Euonymus alatus leaves and twigs

The 80% methanolic extract of Euonymus alatus leaves and twigs afforded three new lignans, (−)-threo-4,9,4′,9′-tetrahydroxy-3,7,3′,5′-tetramethoxy-8-O-8′-neolignan (1), (−)-threo-4,9,4′,9′-tetrahydroxy-3,5,7,3′-tetramethoxy-8-O-8′-neolignan (2), (7R,8R,7′R)-(+)-lyoniresinol (3), together with seventeen known lignans (4-20). The structures of 1-20 were elucidated by extensive 1D and 2D spectroscopic methods including ¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMQC, HMBC and NOESY. All the isolated compounds except for dilignans (19 and 20) significantly inhibited nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells.     

Two novel hydroperoxylated products of 20(S)-protopanaxadiol produced by Mucor racemosus and their cytotoxic activities against human prostate cancer cells

Microbial transformation of 20(S)-protopanaxadiol (1) by Mucor racemosus AS 3.205 yielded two novel hydroperoxylated metabolites and three known hydroxylated metabolites. The structures of the metabolites were identified as 26-hydroxyl-20(S)-protopanaxadiol (2), 23,24-en-25-hydroxyl-20(S)-protopanaxadiol (3), 25,26-en-24(R)-hydroperoxyl-20(S)-protopanaxadiol (4), 23,24-en-25-hydroperoxyl-20(S)-protopanaxadiol (5), and 25-hydroxyl-20(S)-protopanaxadiol (6). 4 and 5 are new compounds. Metabolites 2, 4, and 5 showed the more potent inhibitory effects against DU-145 and PC-3 cell lines than the substrate.     

Pyrrolidinone diterpenoid from Isodon excisus and inhibition of nitric oxide production in lipopolysaccharide-induced macrophage RAW264.7 cells

A new pyrrolidinone diterpenoid, excisusin F (1), was isolated from the aerial parts of Isodon excisus (Lamiaceae), together with four known compounds, and their structures were determined mainly by NMR (1D and 2D) and mass spectrometry. Excisusin F (1) and inflexarabdonin E (3) showed potent inhibitory effects of LPS-induced nitric oxide production in RAW264.7 cells with the IC₅₀ value of 10.4 and 3.8 μM, respectively.     

Synthesis of aurones and their inhibitory effects on nitric oxide and PGE2 productions in LPS-induced RAW 264.7 cells

Sulfuretin is one of major constituents of Rhus verniciflua that exerts anti-inflammatory activities. Some of aurones were synthesized as sulfuretin derivatives and evaluated for their abilities to inhibit NO and PGE₂ production in LPS-induced RAW 264.7 cells in order to reveal the relationship. Of the aurones synthesized in the present study, 2h and 2i, which possess C-6 hydroxyl group in A-ring and methoxy substituents in B-ring, more potently inhibited NO and PGE₂ production and were less cytotoxic than sulfuretin.     

Endogenous nitric oxide generation in protoplast chloroplasts

Key message

NO generation is studied in the protoplast chloroplasts. NO, ONOO ^? and ROS (O ₂ ^? and H ₂ O ₂ ) are generated in chloroplasts. Nitric oxide synthase-like protein appears to be involved in NO generation.

Abstract

Nitric oxide stimulates chlorophyll biosynthesis and chloroplast differentiation. The present study was conducted to better understand the process of NO generation in the leaf chloroplasts and protoplasts. NO, peroxynitrite and superoxide anion were investigated in the protoplasts and isolated chloroplasts using specific dyes, confocal laser scanning and light microscopy. The level of NO was highest after protoplast isolation and subsequently decreased during culture. Suppression of NO signal in the presence of PTIO, suggests that diaminofluorescein-2 diacetate (DAF-2DA) detected NO. Detection of peroxynitrite, a reaction product of NO and superoxide anion, further suggests NO generation. Moreover, generation of NO and peroxynitrite in the chloroplasts of wild-type Arabidopsis and their absence or weak signals in the leaf-derived protoplasts of Atnoa1 mutants confirmed the reactivity of DAF-2DA and aminophenyl fluorescein to NO and peroxynitrite, respectively. Isolated chloroplasts also showed signal of NO. Suppression of NO signal in the presence of 100 μM nitric oxide synthase inhibitors [l-NNA, Nω-nitro-l-arginine and PBIT, S,S′-1,3-phenylene-bis(1,2-ethanediyl)-bis-isothiourea] revealed that nitric oxide synthase-like system is involved in NO synthesis. Suppression of NO signal in the protoplasts isolated in the presence of cycloheximide suggests de novo synthesis of NO generating protein during the process of protoplast isolation. Furthermore, the lack of inhibition of NO production by sodium tungstate (250 μM) and inhibition by l-NNA, and PBIT suggest involvement NOS-like protein, but not nitrate reductase, in NO generation in the leaf chloroplasts and protoplasts.     

Protonation,alkylation, addition and redox reactions of 16, 17 and 18 valence electron [Mo(L)(NO)('S4')] complexes [L = SPh,PMe3, NO; 'S4'2– = 1,2-Bis-(2-mercaptophenylthio)ethane(2-)]

In the quest for complexes modelling functional characteristics of metal sulfur oxidoreductases, a series of molybdenum nitrosyl complexes with sulfur-dominated coordination sphere was synthesized. Treatment of the 16, 17 and 18 valence electron (VE) complexes [Mo(L)(NO)('S₄')] (1–3) [L?=?SPh (1), PMe₃ (2), NO (3), 'S₄'^2–?=?1,2-bis-(2-mercaptophenylthio) ethane(2-)] with the Brönsted acid HBF₄ resulted in formation of different types of products. 1 and 3 were reversibly protonated at one thiolate atom of the 'S₄'^2– ligand;2, however, yielded the phosphonium salt [HPMe₃]BF₄ and the dinuclear [Mo(NO)('S₄')]₂. Alkylation of 1, 2 and 3 by Me₃OBF₄ or Et₃OBF₄ uniformly resulted in high yields of [Mo(L)(NO)(R-'S₄')]BF₄ complexes [L?=?SPh: R?=?Me (5), Et (6); L?=?PMe₃: R?=?Me (7); L?=?NO: R?=?Me (8), Et (9)] in which one thiolate atom of the 'S₄'^2– ligand had become alkylated; the NMR spectra of 5, 6, 8 and 9 indicated that only one out of four theoretically possible diastereoisomers had formed. 5 and 6 were characterized also by single-crystal X-ray structure analyses. A comparison of ν(NO) bands and redox potentials (cyclic voltammetry) of parent complexes and alkylated derivatives showed that alkylation leads to a decrease in electron density at the molybdenum center and to a positive shift in redox potentials. The 16 VE complex 1 could be reduced, also chemically, to give the corresponding 17 VE anion [1]^–, and inserted elemental sulfur into the Mo-SPh bond, forming the 18 VE phenylperthio complex [Mo(η²–SSPh)(NO)('S₄')] (11) which, upon reaction with PPh₃, gave SPPh₃ and regenerated the parent complex 1. These results are discussed with regard to the sequence of proton and electron transfer steps occurring in substrate conversions catalyzed by metal sulfur oxidoreductases.     

A new ursane-type triterpenoid glycoside from Centella asiatica leaves modulates the production of nitric oxide and secretion of TNF-α in activated RAW 264.7 cells

One new ursane-type triterpenoid glycoside, asiaticoside G (1), five triterpenoids, asiaticoside (2), asiaticoside F (3), asiatic acid (4), quadranoside IV (5), and 2α,3β,6β-trihydroxyolean-12-en-28-oic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester (6), and four flavonoids, kaempferol (7), quercetin (8), astragalin (9), and isoquercetin (10) were isolated from the leaves of Centella asiatica. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance (NMR) spectroscopy. The structure of new compound 1 was determined to be 2α,3β,23,30-tetrahydroxyurs-12-en-28-oic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester. The anti-inflammatory activities of the isolated compounds were investigated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Asiaticoside G (1) potently inhibited the production of nitric oxide and tumor necrosis factor-α with inhibition rates of 77.3% and 69.0%, respectively, at the concentration of 100 μM.     

Microbial transformation of 20(S)-protopanaxatriol by Absidia corymbifera and their cytotoxic activities against two human prostate cancer cell lines

Seven hydroxylates of 20(S)-protopanaxatriol (1) transformed by Absidia corymbifera AS 3.3387 were isolated and identified by spectral methods including 2D-NMR. Among them, 7β-hydroxyl-20(S)-protopanaxatriol (2), 7α-hydroxyl-20(S)-protopanaxatriol (3), and 7β, 15α-dihydroxyl-20(S)-protopanaxatriol (7) are new compounds. The metabolites 2, 6, 7, and 8 showed the more potent inhibitory effects against DU-145 and PC-3 cell lines than the substrate.     

Secondary metabolites produced by an endophytic fungus Cordyceps ninchukispora from the seeds of Beilschmiedia erythrophloia Hayata

Four new amide derivatives, designated as cordycepiamides A–D (1–4), together with 14 known compounds (5–18), were isolated from the EtOAc-soluble fraction of the 95% EtOH extract of long-grain rice fermented with the endophytic fungus C. ninchukispora BCRC 31900, derived from the seeds of medicinal plant Beilschmiedia erythrophloia Hayata. Their structures were elucidated by means of spectroscopic and mass-spectrometric analyses, particularly 1D and 2D NMR spectroscopy as well as HRESIMS. All known isolates except 11, were isolated for the first time from this species. The antiinflammatory activities of selected isolated 10 compounds (1, 2, 4–6, 9–12, and 14) were evaluated as inhibitory activities against lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 cell lines. Compound 3→4 was shown to have modest anti-inflammatory effects through inhibition of NO production in LPS-stimulated RAW264.7 cells.     

β-Glucan from Saccharomyces cerevisiae reduces lipopolysaccharide-induced inflammatory responses in RAW264.7 macrophages

Background

β-Glucans obtained from fungi, such as baker's yeast (Saccharomyces cerevisiae)-derived β-glucan (BBG), potently activate macrophages through nuclear factor κB (NFκB) translocation and activation of its signaling pathways. The mechanisms by which β-glucans activate these signaling pathways differ from that of lipopolysaccharide (LPS). However, the effects of β-glucans on LPS-induced inflammatory responses are poorly understood. Here, we examined the effects of BBG on LPS-induced inflammatory responses in RAW264.7 mouse macrophages.

Methods

We explored the actions of BBG in RAW264.7 macrophages.

Results

BBG inhibited LPS-stimulated nitric oxide (NO) production in RAW264.7 macrophages by 35–70% at concentrations of 120–200 μg/ml. BBG also suppressed mRNA and protein expression of LPS-induced inducible NO synthase (iNOS) and mitogen-activated protein kinase phosphorylation, but not NFκB activation. By contrast, a neutralizing antibody against dectin-1, a β-glucan receptor, did not affect BBG-mediated inhibition of NO production. Meanwhile, BBG suppressed Pam3CSK-induced NO production. Moreover, BBG suppressed LPS-induced production of pro-and anti-inflammatory cytokines, including interleukin (IL)-1α, IL-1ra, and IL-27.

Conclusions

Our results indicate that BBG is a powerful inhibitor of LPS-induced NO production by downregulating iNOS expression. The mechanism involves inactivation of mitogen-activated protein kinase and TLR2 pathway, but is independent of dectin-1.

General significance

BBG might be useful as a novel agent for the chemoprevention of inflammatory diseases.     

Spermine oxidase is a regulator of macrophage host response to Helicobacter pylori: enhancement of antimicrobial nitric oxide generation by depletion of spermine

The gastric pathogen Helicobacter pylori causes peptic ulcer disease and gastric cancer. We have reported that in H. pylori-activated macrophages, nitric oxide (NO) derived from inducible NO synthase (iNOS) can kill the bacterium, iNOS protein expression is dependent on uptake of its substrate l-arginine (l-Arg), the polyamine spermine can inhibit iNOS translation by inhibiting l-Arg uptake, and inhibition of polyamine synthesis enhances NO-mediated bacterial killing. Because spermine oxidase (SMO), which back-converts spermine to spermidine, is induced in macrophages by H. pylori, we determined its role in iNOS-dependent host defense. SMO shRNA knockdown in RAW 264.7 murine macrophages resulted in a marked decrease in H. pylori-stimulated iNOS protein, but not mRNA expression, and a 90 % reduction in NO levels; NO production was also inhibited in primary murine peritoneal macrophages with SMO knockdown. There was an increase in spermine levels after H. pylori stimulation that rapidly decreased, while SMO knockdown caused a greater increase in spermine that was sustained. With SMO knockdown, l-Arg uptake and killing of H. pylori by macrophages was prevented. The overexpression of SMO by transfection of an expression plasmid prevented the H. pylori-stimulated increase in spermine levels, and led to increased l-Arg uptake, iNOS protein expression and NO production, and H. pylori killing. In two human monocytic cell lines, U937 and THP-1, overexpression of SMO caused a significant enhancement of NO production with H. pylori stimulation. By depleting spermine, SMO can abrogate the inhibitory effect of polyamines on innate immune responses to H. pylori by enhancing antimicrobial NO production.     

Anti-inflammatory activity of constituents from Glechoma hederacea var. longituba

Rosmarinic acid, its analogues, and a phenolic compound were obtained from G. hederacea var. longituba. There were two new compounds, methyl isoferuloyl-7-(3,4-dihydroxyphenyl) lactate (1) and benzyl-4′-hydroxy-benzoyl-3′-O-β-d-glucopyranoside (4), and four known compounds (2, 3, 5 and 6). The structures of these compounds were determined on the basis of spectroscopic methods. Each compound was tested by NF-κB luciferase assay and three rosmarinic acid analogues inhibited NF-κB production and the induction of COX-2 and iNOS mRNA in HepG2 cells.