Morusin induces apoptosis and suppresses NF-kappaB activity in human colorectal cancer HT-29 cells

Morusin is a pure compound isolated from root bark of Morusaustralis (Moraceae). In this study, we demonstrated that morusin significantly inhibited the growth and clonogenicity of human colorectal cancer HT-29 cells. Apoptosis induced by morusin was characterized by accumulation of cells at the sub-G(1) phase, fragmentation of DNA, and condensation of chromatin. Morusin also inhibited the phosphorylation of IKK-alpha, IKK-beta and IkappaB-alpha, increased expression of IkappaB-alpha, and suppressed nuclear translocation of NF-kappaB and its DNA binding activity. Dephosphorylation of NF-kappaB upstream regulators PI3K, Akt and PDK1 was also displayed. In addition, activation of caspase-8, change of mitochondrial membrane potential, release of cytochrome c and Smac/DIABLO, and activation of caspase-9 and -3 were observed at the early time point. Downregulation in the expression of Ku70 and XIAP was exhibited afterward. Caspase-8 or wide-ranging caspase inhibitor suppressed morusin-induced apoptosis. Therefore, the antitumor mechanism of morusin in HT-29 cells may be via activation of caspases and inhibition of NF-kappaB.

Inhibitory effects of quercetin derivatives on phosphodiesterase isozymes and high-affinity [(3) H]-rolipram binding in guinea pig tissues

Rolipram has high (PDE4(H)) and low (PDE4(L)) affinities for phosphodiesterase (PDE)-4, respectively. In general, it is believed that inhibitions by PDE4(H) and PDE4(L) are respectively associated with an adverse response and with anti-inflammatory and bronchodilating effects. This has provided a rational basis for designing new compounds with high PDE4(H)/PDE4(L) ratios. In the present study, we attempted to determine the PDE4(H)/PDE4(L) ratios of quercetin (1), qercetin-3-O-methylether (3-MQ, 2), quercetin-3,7,4'-O-trimethylether (ayanin, 3), quercetin-3,7,3',4'-O- tetramethylether (QTME, 4), quercetin-3,5,7,3',4'-O-petamethylether (QPME, 5), quercetin-3,5,7,3',4'-O-pentaacetate (QPA, 6), and quercetin-3-O-methyl-5,7,3',4'-O-tetraacetate (QMTA, 7). The activities of PDE1 approximately 5, which were partially separated from homogenates of guinea pig lungs and hearts, were measured by a two-step procedure using adenosine 3',5'-cyclic monophosphate (cAMP) with [(3) H]-cAMP or guanosine 3',5'-cyclic monophosphate (cGMP) with [(3) H]-cGMP as substrates. The IC(50) values of all of these compounds except quercetin (1), 3-MQ (2), and QMTA (7) on PDE1 approximately 5 inhibition were determined. The anti-inflammatory effects of PDE4 inhibitors were reported to be associated with inhibition of PDE4 catalytic activity. Therefore, these IC(50) values for PDE4 inhibition were taken as the PDE4(L) values. The effective concentration (EC(50)), at which one half of the [(3) H]-rolipram bound to high-affinity rolipram binding sites (HARBSs) of brain cell membranes was replaced, was defined as the PDE4(H) value. In the present results, the PDE4(H)/PDE4(L) ratios of quercetin (1), ayanin (3), and QPME (5) were >30, >19, and 11, respectively (Table 1), which are higher than or equal to that of AWD12-281, the selective PDE4 inhibitor with the greatest potential currently undergoing clinical trials for treating asthma and chronic obstructive pulmonary disease.

Phloroglucinols with prooxidant activity from Garcinia subelliptica

A new phloroglucinol, garcinielliptone HF ( 1), possessing an unprecedented skeleton, and the tautomeric pair of garcinielliptone FC ( 2/ 2a) were isolated from the heartwood and pericarp of Garcinia subelliptica, respectively. Their structures, including relative configurations, were elucidated by means of spectroscopic methods. The ability of compounds 1 and 2/ 2a to induce DNA-cleavage activity was examined using supercoiled plasmid pBR322 DNA. In the presence of Cu(II), compounds 1 and 2/ 2a caused significant breakage of pBR322 DNA. The involvement of H2O2 and O2 (*-), and H2O2, O2 (*-), and OH (*) in 1- and 2/ 2a-mediated scission, respectively, was established by inhibition or no protection of DNA breakage by various oxygen radical scavengers. Thus, in the presence Cu(II), 1 and 2/ 2a may show a prooxidant effect on DNA and induce cell death.

Flavonoids with DNA strand-scission activity from Rhus javanica var. roxburghiana

The flavonoids isolated from the stems of Rhus javanica var. roxburghiana, taxifolin (1), fisetin (2), fustin (3), 3,7,4'-trihydroxyflavanone (4) and 3,7,4'-trihydroxyflavone (5) caused breakage of supercoiled plasmid pBR322 DNA in the presence of Cu(II). Cu(I) was shown to be an essential intermediate by using the Cu(I)-specific sequestering reagent neocuproine. The Cu(II)-mediated DNA scissions induced by 1, 2, 3 and 5 were inhibited by the addition of catalase and exhibited DNA strand break by the addition of KI and superoxide dimutase (SOD), while in the Cu(II)-mediated DNA scissions induced by 4 was inhibited by the addition of KI, SOD, and catalase. It is concluded that 1, 2, 3, and 5 can induce H2O2 and superoxide anion, while 4 can induce OH* and H2O2 and subsequent oxidative damage of DNA in the presence of Cu(II).

DNA strand-scission by phloroglucinols and lignans from heartwood of Garcinia subelliptica Merr. and Justicia plants

Five 2,4,6-prenylated phloroglucinols, garcinielliptones HA (1), HB (2), HC (3), HD (4) and HE (5), were isolated from the heartwood of Garcinia subelliptica Merr. Their structures, including relative configurations, were elucidated by means of spectroscopic data analysis. The ability of phloroglucinols, 1-5 and lignans, tuberculatin (8), justicidin A (9), procumbenoside A (10) and ciliatosides A (11) and B (12), isolated from Justicia ciliata and Justicia procumbens, to induce DNA-cleavage activity was examined using pBR322, a supercoiled, covalently closed circular DNA, and it was analyzed by agarose gel electrophoresis. In the presence of Cu (II), compounds 3, 8, 10 and 11 caused significant breakage of supercoiled plasmid pBR322. The products were relaxed circles with no detectable linear forms. In the Cu(II)-mediated DNA damage of 3 and selective compound 8, Cu(I) was shown not to be an essential intermediate by using the Cu(I)-specific sequestering reagent neocuproine.

Antiinflammatory triterpenoids and steroids from Ganoderma lucidum and G. tsugae

The antiinflammatory properties of triterpenoids and steroids from both Ganoderma lucidum and Ganoderma tsugae were studied. Twelve compounds, including ergosta-7,22-dien-3beta-ol (1), ergosta-7,22-dien-3beta-yl palmitate (2), ergosta-7,22-dien-3-one (3), ergosta-7,22-dien-2beta,3alpha,9alpha-triol (4), 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (5), ganoderal A (6), ganoderal B (7), ganoderic aldehyde A (8), tsugaric acid A (9), 3-oxo-5alpha-lanosta-8,24-dien-21-oic acid (10), 3alpha-acetoxy-5alpha-lanosta-8,24-dien-21-oic acid ester beta-d-glucoside (11), and tsugaric acid B (12), were assessed in vitro by determining their inhibitory effects on the chemical mediators released from mast cells, neutrophils, and macrophages. Compound 10 showed a significant inhibitory effect on the release of beta-glucuronidase from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB) whereas compound 9 significantly inhibited superoxide anion formation in fMLP/CB-stimulated rat neutrophils. Compound 10 also exhibited a potent inhibitory effect on NO production in lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma)-stimulated N9 microglial cells. Moreover, compound 9 was also able to protect human keratinocytes against damage induced by ultraviolet B (UV B) light, which indicated 9 could protect keratinocytes from photodamage.

Adult intussusception in Asians: clinical presentations, diagnosis, and treatment

BACKGROUND

Adult intussusception is a rare clinical entity. The presentations and optimal management of adult intussusception in Asians have seldom been reported. The purpose of this study was to determine the causes and management of adult intussusception in Taiwan.

METHODS

A retrospective review performed at four medical centers in Taiwan identified 46 patients, at least 18 years old, with a diagnosis of intestinal intussusception from January 1992 to December 2005. Data related to presentations, diagnosis, treatment, and pathology were analyzed.

RESULTS

There were 28 men and 18 women with a mean age of 58 (range 19-83) years. Twenty-five patients were diagnosed with enteric intussusception and 21 patients with colonic intussusception. Disease in 35 (76.1%) patients was caused by a benign lead point. The most common symptom was abdominal pain, which was seen in all patients. Twenty-five patients presented with acute symptoms that they experienced over a period of less than 3 days. The preoperative diagnosis was 89.1% because of the wide use of abdominal computed tomography (CT). The most sensitive diagnostic modality was abdominal CT (88.6%). For all patients, 76% with enteric intussusception and 28.6% with colonic intussusception underwent operative reduction. At the time of writing, 71.7% patients were still alive. Only two patients died of postoperative complications.

CONCLUSIONS

Most patients with adult intussusception in our series were men, and most intussusceptions were benign and of enteric origin. The most sensitive diagnostic modality is abdominal CT scan. Operative reduction is recommended for enteric intussusceptions but not for colonic intussusceptions. The prognosis of adult intussusception after surgery is good except for malignant intussusception.

Potent suppressive effects of 3-O-methylquercetin 5,7,3',4'-O-tetraacetate on ovalbumin-induced airway hyperresponsiveness

We investigated the suppressive effects of 3-O-methylquercetin 5,7,3',4'- O-tetraacetate (QMTA), a more-potent phosphodiesterase (PDE)3/4 inhibitor than quercetin 3-O-methyl ether (3-MQ), which has been reported to have the potential for treating asthma, against ovalbumin (OVA)-induced airway hyperresponsiveness (AHR). The IC50 value of QMTA for PDE3 was significantly less than that for PDE4. According to the Lineweaver-Burk analysis, QMTA (1-10 microM) competitively inhibited PDE3 and PDE4 activities. The Ki values were 0.9+/-0.3 (n=5) and 3.9+/-0.5 (n=5) microM, respectively, which significantly differed from each other, suggesting that QMTA has higher affinity for PDE3 than for PDE4. QMTA (3-10 microM) concentration-dependently relaxed the baseline level, and significantly inhibited cumulative OVA (10-100 microg/mL)-induced contractions in isolated sensitized guinea pig trachealis suggesting that QMTA has bronchodilator and inhibiting effects on mast cell degranulation. After the secondary challenge, the AHR was measured in unrestrained OVA-sensitized mice, with nebulized methacholine (MCh, 6.25-50 mg/mL), by barometric plethysmography using a whole-body plethysmograph. In the present results, QMTA (3-10 micromol/kg, I. P.) dose-dependently attenuated the enhanced pause (Penh) value induced by MCh (25-50 mg/mL). QMTA (3-10 micromol/kg, I. P.) also significantly inhibited total inflammatory cells, macrophages, neutrophils, lymphocytes, and eosinophils in BALF after determination of Penh values. It also significantly suppressed the release of interleukin (IL)-2, IL-4, IL-5, IFN-gamma, and TNF-alpha, with the exception that 3 micromol/kg QMTA did not suppress the releases of IL-5. QMTA even at 1 micromol/kg significantly inhibited eosinophils, IL-2, and TNF-alpha. In conclusion, our results strongly suggest that QMTA has greater potential than 3-MQ for the treatment of asthma.

Antiplatelet Effect and Selective Binding to Cyclooxygenase (COX) by Molecular Docking Analysis of Flavonoids and Lignans

The known flavonoids ginkgetin (1), taiwanhomoflavone A (2), taiwanhomoflavone B (3), and taiwanhomoflavone C (4) and eight known lignans: justicidin B (9), justicidin C (10), justicidin D (11), chinensinaphthol methyl ether (12), procumphthalide A (13), procumbenoside A (15), and ciliatosides A (16) and B (17) were isolated from Cephalotaxus wilsoniana and Justicia species, respectively. The antiplatelet effects of the above constituents on human platelet-rich plasma (PRP) were evaluated. Of the compounds tested on human PRP, compounds 1, 4, 9, and 11 showed inhibition of secondary aggregation induced by adrenaline. Compound 1 had an inhibitory effect on cyclooxygenase-1 (COX-1). Molecular docking studies revealed that 1 and the related compounds apigenin (5), cycloheterophyllin (6), broussoflavone F (7), and quercetin (8) were docked near the gate of active site of COX-1. It indicated that the antiplatelet effect of 1, 4, 9, and 11 is partially owed to suppression of COX-1 activity and reduced thromboxane formation. Flavonoids, 1, 5, 6, 7, and 8 may block the gate of the active site of COX-1 and interfere the conversion of arachidonic acid to prostaglandin (PG) H₂ in the COX-1 active site.

Structure and mechanism of Helicobacter pylori fucosyltransferase. A basis for lipopolysaccharide variation and inhibitor design

Helicobacter pylori alpha1,3-fucosyltransferase (FucT) is involved in catalysis to produce the Lewis x trisaccharide, the major component of the bacteria's lipopolysaccharides, which has been suggested to mimic the surface sugars in gastric epithelium to escape host immune surveillance. We report here three x-ray crystal structures of FucT, including the FucT.GDP-fucose and FucT.GDP complexes. The protein structure is typical of the glycosyltransferase-B family despite little sequence homology. We identified a number of catalytically important residues, including Glu-95, which serves as the general base, and Glu-249, which stabilizes the developing oxonium ion during catalysis. The residues Arg-195, Tyr-246, Glu-249, and Lys-250 serve to interact with the donor substrate, GDP-fucose. Variations in the protein and ligand conformations, as well as a possible FucT dimer, were also observed. We propose a catalytic mechanism and a model of polysaccharide binding not only to explain the observed variations in H. pylori lipopolysaccharides, but also to facilitate the development of potent inhibitors.

Synthetic 2',5'-dimethoxychalcones as G(2)/M arrest-mediated apoptosis-inducing agents and inhibitors of nitric oxide production in rat macrophages

In an effort to develop novel antitumor or chemopreventive agents, a series of 2',5'-dimethoxychalcone derivatives were prepared by Claisen-Schmidt condensation of appropriate acetophenones with suitable aromatic aldehyde. In vitro screening revealed low micromolar activity (IC(50)) against several human cancer lines. Activity in MCF-7 cells correlated with the ability to induce G(2)/M arrest-mediated apoptosis following drug treatment by the most potent agent, 8, an observation further reinforced by fluorescence microscopy. Compounds 3, 8, and 10 showed potent inhibitory effect on NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophage-like cells. The present results demonstrated that 3, 8, and 10 are potential anti-inflammatory and cancer chemopreventive agents.

Activation of phosphoinositide 3-kinase and Src family kinase is required for respiratory burst in rat neutrophils stimulated with artocarpol A

Artocarpol A (ART), a natural product isolated from Artocarpus rigida, stimulated superoxide anion (O2*-) generation, which was inhibited by 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY 294002), a phosphoinositide 3-kinase (PI3K) inhibitor, in rat neutrophils. ART stimulated phosphorylation of protein kinase B (PKB/Akt) on both T308 and S473 residues, and LY 294002 inhibited these effects. Rat neutrophils expressed both class IA PI3K subunits (p85, p110alpha, p110beta, and p110delta) and a class IB PI3K subunit (p110gamma) as assessed by a combination of Western blotting and reverse transcription-polymerase chain reaction (RT-PCR) approaches. Stimulation of neutrophils with ART evoked phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P3) formation, which reached a maximal level at 2 min and was attenuated by LY 294002, as evidenced by immunofluorescence microscopy and by flow cytometry. Detectable membrane-association of class IA PI3Ks, class IB PI3K and Ras was seen as early as 1.5, 0.5 and 1.5 min, respectively, after stimulation with ART. The kinetics of ART-induced Ras activation paralleled the kinetics of class IA PI3Ks recruitment to membrane caused by ART, and the p85 and p110gamma immunoprecipitates contain Ras. ART stimulated Src family kinase activation, which was detectable within 1.5 min of incubation with ART. Both Src kinase activity and PtdIns(3,4,5)P3 formation in ART-stimulated neutrophils were inhibited by 4-amino-1-tert-butyl-3-(1'-naphthyl)pyrazolo[3,4-d]pyrimidine (PP1 analog). PP1 analog also attenuated the ART-stimulated O2*- generation in rat neutrophils. These results indicate that the stimulation of respiratory burst by ART in neutrophils implicates PI3K signaling.

Caspase-8 acts as a key upstream executor of mitochondria during justicidin A-induced apoptosis in human hepatoma cells

Justicia procumbens is a traditional Taiwanese herbal remedy used to treat fever, pain, and cancer. Justicidin A, isolated from Justicia procumbens, has been reported to suppress in vitro growth of several tumor cell lines as well as hepatoma cells. In this study, justicidin A activated caspase-8 to increase tBid, disrupted mitochondrial membrane potential (Delta psi(m)), and caused the release of cytochrome c and Smac/DIABLO in Hep 3B and Hep G2 cells. Justicidin A also reduced Bcl-x(L) and increased Bax and Bak in mitochondria. Caspase-8 inhibitor (Z-IETD) attenuated the justicidin A-induced disruption of Delta psi(m). Growth of Hep 3B implanted in NOD-SCID mice was suppressed significantly by oral justicidin A (20 mg/kg/day). These results indicate that justicidin A-induced apoptosis in these cells proceeds via caspase-8 and is followed by mitochondrial disruption.

Antiplatelet prenylflavonoids from Artocarpus communis

Four flavonoids, dihydroartomunoxanthone (1), artomunoisoxanthone (2), cyclocomunomethonol (3) and artomunoflavanone (4), together with three known compounds, artochamins B (5), D and artocommunol CC (6) were isolated from the cortex of the roots of Artocarpus communis. The structures of 1-4 were determined by spectroscopic methods. The antiplatelet effects of the flavonoids, 1-3, 5 and 6 on human platelet-rich plasma (PRP) were evaluated. Of the compounds tested in human PRP, compounds 1, 5 and 6 showed significant inhibition of secondary aggregation induced by adrenaline. It is concluded that the antiplatelet effect of 1, 5 and 6 is mainly owing to an inhibitory effect on thromboxane formation.

New Terpenoids from Amentotaxus formosana

[structure: see text] Amentoditaxone (1), possessing an unprecedented diterpenoid skeleton, along with two new terpenoids, amentotaxin WC (2) and amentotaxone (3), were established by extensive analysis of spectroscopic data.

Mechanisms of suppression of nitric oxide production by 3-O-methylquercetin in RAW 264.7 cells

Rhamnus nakaharai Hayata (Rhamnaceae) is used as a folk medicine in Taiwan for treating constipation, inflammation, tumors, and asthma. 3-O-Methylquercetin (3-MQ), a main constituent of the plant, has been reported to have potential for use in the treatment of asthma. The mechanisms of anti-inflammation of 3-MQ are still unclear. Nitric oxide (NO) production induced by lipopolysaccharide (LPS) through iNOS expression in RAW 264.7 cells, a mouse macrophage cell line, may reflect the degree of inflammation and may provide a measure for assessing the effect of drugs on the inflammatory process. Therefore, we were interested in investigating the mechanisms of suppression of NO production by 3-MQ in RAW 264.7 cells. 3-MQ (1-10 microM) concentration-dependently inhibited LPS (100 ng/mL)-induced NO production in RAW 264.7 cells. The IC(50) value was calculated to be 4.23 microM. 3-MQ (1-10 microM) significantly and concentration-dependently inhibited LPS (100 ng/mL)-induced iNOS protein and mRNA expressions in cells. The IC(50) values were calculated to be 4.36 and 6.53 microM, respectively. There was no significant difference among these three IC(50) values of 3-MQ. In conclusion, 3-MQ may exert its anti-inflammatory effect through the inhibition of iNOS DNA transcription.

Inhibition of lipopolysaccharide-stimulated NO production by crotafuran B in RAW 264.7 macrophages involves the blockade of NF-κB activation through the increase in IκBα synthesis

Crotafuran B, a natural pterocarpanoid isolated from Crotalaria pallida, inhibited the lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production (IC50 16.4+/-0.7 microM) and inducible nitric oxide synthase (iNOS) protein and mRNA expression (IC50 11.5+/-0.6 microM and 11.8+/-2.2 microM, respectively), but not via its cytotoxicity or the inhibition of iNOS enzyme activity, in RAW 264.7 macrophages. Crotafuran B also reduced the iNOS promoter activity (IC50 13.4+/-0.1 microM) in piNOS-LUC-transfected cells. Crotafuran B treatment inhibited the p65 nuclear translocation and the nuclear factor-kappaB (NF-kappaB) DNA binding activity in LPS-activated macrophages. Crotafuran B also reduced the NF-kappaB transcriptional activity in pNF-kappaB-LUC-transfected cells. Crotafuran B had no effect on the LPS-induced phosphorylation of inhibitory kappaBalpha (IkappaBalpha), but enhanced the cellular level of IkappaBalpha that rebounded to the basal levels and increased the IkappaBalpha mRNA expression. These results indicate that the crotafuran B inhibition of NO production involves a decrease in the iNOS gene expression via the inhibition of NF-kappaB activation through the increase in IkappaBalpha synthesis.

Cytotoxic prenylflavonoids from Artocarpus elasticus

Five new prenylated flavonoids, artelastoheterol (1), artelasticinol (2), cycloartelastoxanthone (3), artelastoxanthone (4), and cycloartelastoxanthendiol (5), along with five known compounds, were isolated from the root bark of Artocarpus elasticus. The structures of 1-5 were elucidated by spectroscopic methods and through comparison with data reported in the literature. The previously known compound artonol A (6) exhibited cytotoxic activity against the A549 human cancer cell line, with an ED50 value of 1.1 microg/mL.

Immunohistochemical and molecular assessment of human herpesvirus type 8 in gastrointestinal tumours

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract, histologically identified as highly cellular spindle or epithelioid cell tumours, and often positive for CD34 (60-70%). Kaposi's sarcomas (KSs) are similar to GISTs: they are most often found in the gastrointestinal tract (although cutaneous lesions do occur), they are also composed of spindle or epithelioid cells (although erythrocytes are also seen), and the tumour cells are nearly all positive for CD34. Human herpesvirus type 8 (HHV-8) DNA has been found consistently in all types of KS, in particular in CD34 positive KS tumour cells. However, the association between HHV-8 and GIST has not been investigated.

AIMS

To assess the presence of HHV-8 in GISTs.

METHODS

Paraffin wax embedded tissues of 86 primary GISTs and their recurrent or metastatic tumours were analysed immunohistochemically for the CD34 antigen and HHV-8 latent nuclear antigen 1 (LNA-1) and by means of the nested polymerase chain reaction (PCR) and real time PCR for HHV-8 DNA.

RESULTS

None of the 86 GISTs contained HHV-8 DNA sequences or LNA-1 positive cells.

CONCLUSIONS

These results demonstrate the lack of HHV-8 infection in GIST tumour cells. HHV-8 does not appear to play a role in the pathogenesis of GIST, irrespective of the status of the tumour.

Artocarpol A stimulation of superoxide anion generation in neutrophils involved the activation of PLC, PKC and p38 mitogen-activated PK signaling pathways

1 Artocarpol A (ART), a natural phenolic compound isolated from Artocarpus rigida, stimulated a slow onset and long-lasting superoxide anion generation in rat neutrophils, whereas only slightly activated the NADPH oxidase in a cell-free system. 2 Pretreatment of neutrophils with pertussis toxin (1 microg ml(-1)), 50 microM 2'-amino-3'-methoxyflavone (PD 98059), or 1 microM 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene (U0126) had no effect on ART-stimulated superoxide anion generation. ART (30 microM) did not induce extracellular signal-regulated kinase (ERK) phosphorylation. 3 4-(4-Fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole (SB 203580) markedly attenuated the ART-stimulated superoxide anion generation (IC50 value of 4.3+/-0.3 microM). Moreover, ART induced p38 mitogen-activated PK (MAPK) phosphorylation and activation. 4 The superoxide anion generation in response to ART was also substantially inhibited in a Ca2+-free medium, and by pretreatment with 1 microM 1-[6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl]-1H-pyrrole-2,5-dione (U-73122) and 100 microM 2-aminoethyldiphenyl borate (2-APB). ART (30 microM) stimulated the [Ca2+]i elevation in the presence or absence of external Ca2+, and also increased the D-myo-inositol 1,4,5-trisphosphate formation. 5 2-[1-(3-Dimethylaminopropyl)-1H-indol-3-yl]-3-(1H-indol-3-yl)-maleimide (GF 109203X) greatly inhibited the ART-stimulated superoxide anion generation (IC50 value of 7.8+/-1.0 nM). ART increased the recruitment of PKC-alpha, -betaI, and -betaII to the plasma membrane of neutrophils, and stimulated Ca2+-dependent PKC activation in the cytosol preparation. 6 ART induced the phosphorylation of p47phox, which was attenuated by GF 109203X. Moreover, ART evoked the membrane association of p47(phox), which was inhibited by GF 109203X and SB 203580. 7 These results indicate that the ART stimulation of superoxide anion generation involved the activation of p38 MAPK, PLC/Ca2+, and PKC signaling pathways in rat neutrophils.

Terpenoids with a new skeleton and novel triterpenoids with anti-inflammatory effects from Garcinia subelliptica

Three novel phloroglucinol derivatives, garcinielliptones F (1), H (3), and I (4), and two novel terpenoids, garcinielliptones G (2) and J (5), with a new skeleton have been isolated from the seeds of Garcinia subelliptica. Their structures, including relative configurations, were elucidated by spectroscopic methods and computer-generated molecular modeling. Compound 1 showed potent inhibitory effects on the release of beta-glucuronidase and lysozyme from rat neutrophils that had been stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB). This effect was concentration-dependent with IC(50) values of 26.9+/-2.6 and 20.0+/-1.3 microM, respectively. Compound 1 also showed a potent concentration-dependent inhibitory effect on superoxide anion generation in rat neutrophils stimulated with fMLP/CB, with an IC(50) value of 17.0+/-0.9 microM. Compound 4 showed a potent inhibitory effect on NO production in culture media of N9 cells in response to lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma) in a concentration-dependent manner with an IC(50) value of 7.4+/-0.2 microM.