Delphinidin attenuates neoplastic transformation in JB6 Cl41 mouse epidermal cells by blocking Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling

Recent studies suggest that anthocyanidins play a pivotal role in the chemopreventive effects of fruits and vegetables. However, the underlying molecular mechanisms and cellular targets remain unknown. Neoplastic transformation of cells and inflammation are considered to be major events contributing to carcinogenesis. Here, we report that delphinidin, a major dietary anthocyanidin, inhibits tumor promoter-induced transformation and cyclooxygenase-2 (COX-2) expression in JB6 promotion-sensitive mouse skin epidermal (JB6 P+) cells by directly targeting Raf and mitogen-activated protein kinase kinase (MEK). Delphinidin inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic transformation and COX-2 expression at both the protein and transcriptional levels. The activation of activator protein-1 and nuclear factor-kappaB induced by TPA was dose dependently inhibited by delphinidin treatment. Delphinidin strongly suppressed Raf1 and MEK1 kinase activities and subsequently attenuated TPA-induced phosphorylation of MEK, extracellular signal-regulated kinase (ERK), p90RSK, and MSK. Although delphinidin suppressed ERK and c-Jun NH(2)-terminal kinase activities, it was more effective at inhibiting Raf1 or MEK1 activities. Pull-down and competition assays revealed that delphinidin binds with Raf1 or MEK1 noncompetitively with ATP. Delphinidin also dose dependently suppressed JB6 P+ cell transformation induced by epidermal growth factor and H-Ras, both of which are involved in the activation of Raf/MEK/ERK signaling. Together, these findings suggested that the targeted inhibition of Raf1 and MEK activities and COX-2 expression by delphinidin contribute to the chemopreventive potential of fruits and vegetables.

Prostaglandin E2 (PGE2) and thromboxane A2 (TXA2) synthesis is regulated by conjugated linoleic acids (CLA) in human macrophages

Conjugated linoleic acid (CLAs) are positional and geometric isomers of linoleic acid with have a potential anti-atherosclerotic and anti-inflammation properties. Metabolites of arachidonic acid--prostaglandins and thromboxans--are endogenous mediators of inflammation. Prostaglandin E(2) and thromboxan A(2) which are a products of two izoformes of cyclooxygenases (COX-1 and COX-2) in macrophages, play an important role in this process. COX-1 is a constitutive enzyme, whereas the COX-2 is inducible and its amount in the cell rapidly increases during inflammation (e.g. via NF kappaB pathway). The aim of the study was to test the effect of CLAs on cyclooxygenases (COX-1 and COX-2) activity, their mRNA expression and protein content in macrophages. Additionally the active form of the kappaB (NF kappaB) transcription factor was measured. For the experiments monocytes from monocytic cell line (THP-1) and from human venous blood were used. Monocytes were differentiated to macrophages and cultured with 30 muM CLAs or linoleic acid for 48 h. The COX-1 and COX-2 products - PGE(2) and TXB(2), were measured by ELISA method. The enzymes (COX-s) activity were estimated by spectroscopic method. mRNA expression and protein analysis were analysed by real-time PCR and Western blot technique. In macrophages cultured with CLAs reduction of TXB(2) and PGE(2) concentration was observed. Significant change in COX-2 expression in cells cultured with trans-10, cis-12 CLA (in macrophages obtained from peripheral blood) was observed. COX-1 inhibition was resulting from competition of CLA and linoleic acid with arachidonic acid.

In vitro pharmacological evaluation of three Barleria species

ETHNOPHARMACOLOGICAL RELEVANCE

Various parts of Barleria prionitis L. (Acanthaceae) are used in traditional medicine to treat infection-related ailments. A comparison of their activities and knowledge of their mechanisms of action are important for drug development and conservation.

AIMS OF THE STUDY

This study investigated the antibacterial effects and underlying mechanisms of action of the anti-inflammatory activities of different parts of three Barleria species of South African origin.

MATERIALS AND METHODS

Crude extracts of different parts of three Barleria species were investigated in vitro for their biological activity. Antibacterial activity was evaluated using the micro-dilution assay against two Gram-positive and two Gram-negative bacteria. Anti-inflammatory activity was evaluated using the cyclooxygenase COX-1 and COX-2 assays.

RESULTS

All the extracts showed broad-spectrum antibacterial activity with minimum inhibitory concentrations ranging from 0.059 to 6.25mg/ml. Twelve out of 21 crude extracts evaluated showed good activity (>70%) in the COX-1 assay while 10 extracts showed good activity in the COX-2 assay. All the petroleum ether extracts (except B. prionitis stem) exhibited good inhibition of prostaglandin synthesis in COX-1.

CONCLUSION

The results demonstrated the therapeutic potential of these plants as antibacterial and anti-inflammatory agents. Their anti-inflammatory properties are mediated by the inhibition of the cyclooxygenase enzymes.

Anti-inflammatory activity of flavonoids from Cayaponia tayuya roots

ETHNOPHARMACOLOGICAL RELEVANCE

Taiuiá or tayuya (Cayaponia tayuya, Cucurbitaceae) is a climbing, lignified plant with a large swollen root that has traditionally been used as an anti-inflammatory and anti-rheumatic agent in the folk medicine of Brazil, Peru, and Colombia.

THE AIM OF THE STUDY

We have assayed the pharmacological properties of a flavonoid fraction obtained from the butanol extract of Cayaponia tayuya roots using two models of topical mouse ear oedema, paying special attention to its influence on the induction on pro-inflammatory enzymes and peptidic mediators.

MATERIAL AND METHODS

The in vivo experiments involved both the acute oedema induced by a single application of TPA and the subchronic inflammation brought on by repeated applications of TPA. The effects on the induction of pro-inflammatory enzymes and peptidic mediators in RAW 264.7 macrophages were analyzed with the aid of Western blot analysis.

RESULTS

The extract was identified as a mixture of flavonoids in which vicenin-2, spinosin, isovitexin, and a mixture of swertisin and isoswertisin were found. In acute TPA-induced oedema in mouse ears, the flavonoid-enriched fraction (at a dose of 0.5mg/ear) inhibited the oedema by 66% (4.2+/-0.6 mg vs. 12.3+/-1.4 mg, P<0.01) while in the subchronic model, the inhibition reached 37% at a dose of 0.5mg/ear x 7 applications (7.5+/-0.6 mg vs. 11.9+/-1.3mg, P<0.05). When assayed in vitro, the flavonoid showed no toxicity at 33.45 microg/mL on RAW 264.7 macrophages. Although the nitric oxide production in these cells was moderately reduced (42%) at 33.45 microg/mL, the flavonoid-enriched fraction had no effect on TNF-alpha production. In addition, at 22.30 microg/mL, the test sample inhibited both iNOS and COX-2 expression by 98% and 49%, respectively.

CONCLUSION

These results indicate that the anti-inflammatory activity of flavonoids from tayuya roots most likely stems from their inhibition of the induction of the enzymes COX-2 and iNOS.

Korean red ginseng extract induces apoptosis and decreases telomerase activity in human leukemia cells

AIM OF THIS STUDY

Korean red ginseng (KRG, Panax ginseng C.A. Meyer Radix rubra) has been used to treat various diseases including cancer. However, the molecular mechanisms responsible for KRG extract induced apoptosis and telomerase inhibition remain unclear.

MATERIALS AND METHODS

The hot water extract from KRG was used to evaluate the mechanism of induction of apoptosis in U937 human leukemia cells and its effects on cyclooxgenase-2 (COX-2) and telomerase activity.

RESULTS

KRG extract treatment to U937 cells resulted in growth inhibition and induction of apoptosis in a concentration-dependent manner as measured by hemacytometer counts, MTT assay, fluorescence microscopy, agarose gel electrophoresis and flow cytometry analysis. The increase in apoptosis was associated with the down-regulation of antiapoptotic Bcl-2, Bcl-X(L), and IAPs family members, and the activation of caspase-3. KRG extract treatment also decreased the expression levels of COX-2 and inducible nitric oxide synthase. Furthermore, KRG extract treatment progressively down-regulated the expression of human telomerase reverse transcriptase, a main determinant of the telomerase enzymatic activity, with inhibiting the expression of c-Myc in a concentration-dependent manner.

CONCLUSIONS

These results provide important new insights into the possible molecular mechanisms of the anticancer activity of KRG extract.

Inhibition of COX-2 and activation of peroxisome proliferator-activated receptor gamma synergistically inhibits proliferation and induces apoptosis of human pancreatic carcinoma cells

Although inhibition of cyclooxygenase-2 (COX-2) or activation of peroxisome proliferators-activated receptor gamma (PPAR-gamma) leads to growth inhibition in malignancies, the synergistic anti-tumor effects of combination of COX-2 inhibitor (NS-398) and PPAR-gamma agonist (rosiglitazone) on the human pancreatic cancer cells remains unknown. Here, we evaluated the effects of NS-398 and/or rosiglitazone on the cell proliferation and apoptosis in a pancreatic cancer cell line, SW1990. NS-398 and rosiglitazone decreased cell proliferation in a dose- and time-dependent manner. Proliferating cell nuclear antigen (PCNA) labeling index significantly decreased in the cells treated with either NS-398 or rosiglitazone. Both NS-398 and rosiglitazone alone induced apoptotic cell death of SW1990. The combination of NS-398 and rosiglitazone exerted synergistic effects on proliferation inhibition, and apoptosis induction in SW1990 cells, with down-regulation of Bcl-2 and up-regulation of Bax expression. Our results indicate that simultaneous targeting of COX-2 and PPAR-gamma inhibits pancreatic cancer development more effectively than targeting each molecule alone.

Long-term NSAID treatment directly decreases COX-2 and mPGES-1 production in the articular cartilage of patients with osteoarthritis

OBJECTIVE

To simultaneously study the effect of a selective cyclooxygenase-2 (COX-2) inhibitor and that of a classic non-steroidal anti-inflammatory drug (NSAID) on the expression of pro-inflammatory genes in the cartilage of patients with severe knee osteoarthritis (OA) and in cultured human OA chondrocytes.

METHODS

A 3-month clinical trial was carried out on 30 patients with severe knee OA scheduled for knee replacement surgery. Patients were randomized into two groups: patients treated with celecoxib (CBX) and patients treated with aceclofenac (ACF). OA patients who did not want to be treated served as the control group. After surgery, cartilage was processed for molecular biology studies. We also employed cultured chondrocytes from different OA patients to examine NSAID effects on pro-inflammatory gene expression in cells stimulated with interleukin (IL)-1beta.

RESULTS

Both CBX and ACF inhibited COX-2, microsomal prostaglandin E synthase-1 (mPGES-1) and inducible nitric oxide synthase (iNOS) synthesis in the articular cartilage of OA patients. In cultured chondrocytes, both NSAID decreased COX-2 and mPGES-1 synthesis and prostaglandin E2 (PGE2) release induced by IL-1beta, while no effect was observed on nitric oxide or iNOS synthesis. In OA patients, only CBX decreased tumor necrosis factor alpha and IL-1beta expression in the cartilage, while both NSAID diminished IL-1beta induced cytokine synthesis in cultured OA chondrocytes.

CONCLUSIONS

Both NSAID diminished PGE2 release and induced a decrease in COX-2 and mPGES-1 synthesis in the cartilage from OA patients and in OA chondrocytes. These data suggest that prolonged therapy with PGE2 blocking agents decreases PGE2 production not only by direct inhibition of COX-2 activity, but also by down-regulating COX-2 and mPGES-1 synthesis in the cartilage. However, CBX and ACF seem to have a different anti-inflammatory profile in controlling pro-inflammatory gene expression in the cartilage.

Aspisol inhibits tumor growth and induces apoptosis in breast cancer

Nonsteroidal anti-inflammatory drugs inhibit cell proliferation and induce apoptosis in various cancer cell lines, which is considered to be an important mechanism for their anti-tumor activity and cancer prevention. However, the molecular mechanisms through which these compounds induce apoptosis are not well understood.

AIM

to determine the effects of nonselective cyclooxygenase-2 (COX-2) inhibitor, aspisol on breast cancer cells in vitro and in vivo.

METHODS

The cytotoxic activity of aspisol was evaluated by MTT assay. The apoptosis index of cells was measured by flow cytometry. Immunohistochemical staining was used to detect expressions of COX-2 and caspase-3 in MDA-MB-231 cells. The expression of bcl-2 and bax was analyzed by Western blot analysis. The content of prostaglandin E2 (PGE2) in MDA-MB-231 cells was estimated by ELISA. In vivo apoptosis of the tumor cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).

RESULTS

Our results showed that aspisol reduced viability of MDA-MB-231 cells in time- and dose- dependent fashions and induced apoptosis by increase of caspase-3 and bax expressions while decrease of COX-2 and bcl-2 expression in vitro. In addition, exposure to aspisol decreased the basal release of PGE2. In vivo, aspisol also inhibited the proliferation of breast cancer cells and induced their apoptosis.

CONCLUSIONS

Our in vitro and in vivo data indicated that the antitumor effects of aspisol on breast cancer cells was probably mediated by the induction of apoptosis, and it could be linked to the downregulation of the COX-2 or bcl-2 expression and up-regulation of caspase-3 or bax expression.

Anti-inflammatory, anti-angiogenic and anti-nociceptive activities of Saururus chinensis extract

ETHNOPHARMACOLGICAL RELEVANCE: The aerial parts of Saururus chinensis Baill. are used for the treatment of edema and inflammatory diseases in the Oriental folk medicine.

AIM OF THE STUDY

This study aimed to elucidate anti-inflammatory and related activities of the ethanol extract (SC) of the dried aerial parts of Saururus chinensis Baill.

MATERIALS AND METHODS

Anti-angiogenic and anti-nociceptive activities of SC were analyzed using the chick chorioallantoic membrane (CAM) assay and acetic acid-induced writhing response, respectively. Anti-inflammatory activity of SC was evaluated using acetic acid-induced vascular permeability, carrageenan-induced air pouch formation and analyses of nitrite content and induced nitric oxide synthase (iNOS) level in the macrophage cells.

RESULTS

SC dose-dependently displayed a strong inhibition in the CAM angiogenesis. SC showed significant anti-nociceptive activity in the writhing model. The anti-inflammatory activity of SC was also assessed in the two in vivo models, such as vascular permeability and air pouch models in mice. SC suppressed production of nitric oxide and induction of iNOS and cyclooxygenase-2 in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages.

CONCLUSION

The aerial parts of Saururus chinensis possess potent anti-angiogenic and anti-nociceptive activities in addition to anti-inflammatory activity, which partly supports its therapeutic efficacy.

Anti-inflammatory effects of glycyrol isolated from Glycyrrhiza uralensis in LPS-stimulated RAW264.7 macrophages

The anti-inflammatory effects of glycyrol, a benzofuran coumarin isolated from Glycyrrhizae Radix, were studied. Glycyrol of 5, 25 and 50 microM dose-dependently inhibited nitric oxide (NO) production by down-regulating inducible nitric oxide synthase (iNOS), and alleviated cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW264.7 macrophages, in both the mRNA and the protein. Furthermore, glycyrol dose-dependently decreased the mRNA of the pro-inflammatory cytokines IL-1beta and IL-6. LPS-induced NF-kappaB activation was prevented in RAW264.7 macrophages by inhibition of I-kappaBalpha phosphorylation. In addition, administration of glycyrol (30 and 100 mg/kg, i.p) reduced the thickness of carrageenan-induced mouse-paw edema swelling. Taken together, our results indicate that glycyrol is an important anti-inflammatory constituent of Glycyrrhizae Radix, and that its anti-inflammatory effect is attributed to the inhibition I-kappaBalpha phosphorylation.

Tanshinone IIA suppresses inflammatory bone loss by inhibiting the synthesis of prostaglandin E2 in osteoblasts

Tanshinone IIA isolated from Danshen is widely used in Oriental medicine. However, the action of tanshinone IIA in inflammatory bone-resorptive diseases remains unknown. Here we examined the effect of tanshinone IIA in inflammation-mediated osteoclastic bone resorption. Tanshinone IIA inhibited osteoclast differentiation in cocultures of bone marrow cells and calvarial osteoblasts. Tanshinone IIA regulated the expression of receptor activator of NF-kappaB ligand and osteoprotegerin in osteoblasts treated with lipopolysaccharide (LPS). Also, tanshinone IIA inhibited prostaglandin E(2) (PGE(2)) synthesis by inhibiting Cyclooxygenase-2 (COX-2) expression induced by LPS. Furthermore, tanshinone IIA greatly suppressed bone loss in the mouse models of bone loss. Our findings suggest that tanshinone IIA inhibits osteoclast formation by inhibiting COX-2/PGE(2) signaling and by suppressing bone erosion in vivo. These results suggest that tanshinone IIA may be of therapeutic value as an anti-bone-resorptive drug in the treatment of bone-related disease.

Bradykinin stimulates prostaglandin E2 production and cyclooxygenase activity in equine nonglandular and glandular gastric mucosa in vitro

REASONS FOR PERFORMING STUDY

There are few data available regarding regulation of prostaglandin (PG) generation by equine gastric mucosae and the role of the cyclooxygenase (COX) isoforms in their production.

OBJECTIVES

To: 1) characterise and quantify PGE2 output in vitro; 2) examine the sensitivity of PGE2 production to exogenous bradykinin (BK) exposure; 3) determine the contribution of the COX-1 and COX-2 pathways to basal and BK-stimulated PGE2 production; and 4) measure if BK influences electrogenic ion transport in equine gastric mucosae in vitro.

METHODS

Full thickness gastric sheets were obtained from horses at post mortem, stripped of muscle layers and mounted in Ussing chambers. Tissues were exposed to bradykinin (BK, 0.1 micromol/l) either alone, or following pretreatment with a selective COX-2 inhibitor (NS-398, 1 micromol/l) or a nonselective COX inhibitor (piroxicam, 1 micromol/l), or were untreated.

RESULTS

BK administration increased PGE2 output from the basolateral but not the apical faces of both tissue types. Piroxicam, but not NS-398, reduced basolateral PGE2 release below control levels in both tissue types. Both piroxicam and NS-398 pretreatment inhibited BK-stimulated PGE2 release. In separate experiments, BK was without effect upon electrophysiological parameters of tissues mounted in Ussing chambers.

CONCLUSIONS

PGE2 is produced by the nonglandular and glandular equine gastric mucosae in vitro. Significantly more PGE2 is released basolaterally than apically. BK stimulated the production of PGE2 from the basolateral side of both tissue types. These findings suggest that COX-1 is a significant pathway for basal PGE2 production from the basolateral faces of both nonglandular and glandular equine gastric mucosae in vitro.

Ethyl pyruvate has an anti-inflammatory effect by inhibiting ROS-dependent STAT signaling in activated microglia

Ethyl pyruvate (EP) has been demonstrated to have an anti-inflammatory function. However, the molecular mechanisms underlying the anti-inflammatory action of EP are largely unknown. We here show that EP exerts its anti-inflammatory effect by inhibiting ROS-dependent STAT signaling through its antioxidant activity, like vitamin C or N-acetyl-L-cysteine. The inhibition of STAT1 and STAT3 by EP prevented their translocation to the nucleus and consequently inhibited expression of iNOS and COX-2 by inhibiting STAT1- and STAT3-mediated transcriptional activity, followed by changes in chromatin conformation via deacetylation of histones H3 and H4 in both gene promoters. EP also suppressed transcripts of other STAT-responsive inflammatory genes such as IL-1beta, IL-6, TNF-alpha, and MCP-1. We further found that the mechanism of inhibition of STAT1 and STAT3 by EP is due to inhibition of JAK2 through Rac1 inactivation and SOCS1 induction. These findings offer new therapeutic possibilities for EP based on a better understanding of the mechanism underlying the action of EP.

The role of reactive oxygen species in arsenite and monomethylarsonous acid-induced signal transduction in human bladder cells: acute studies

Arsenicals are known to induce ROS, which can lead to DNA damage, oxidative stress, and carcinogenesis. A human urothelial cell line, UROtsa, was used to study the effects of arsenicals on the human bladder. Arsenite [As(III)] and monomethylarsonous acid [MMA(III)] induce oxidative stress in UROtsa cells after exposure to concentrations as low as 1 microM and 50 nM, respectively. Previous research has implicated ROS as signaling molecules in the MAPK signaling pathway. As(III) and MMA(III) have been shown to increase phosphorylation of key proteins in the MAPK signaling cascade downstream of ErbB2. Both Src phosphorylation (p-Src) and cyclooxygenase-2 (COX-2) are induced after exposure to 50 nM MMA(III) and 1 microM As(III). These data suggest that ROS production is a plausible mechanism for the signaling alterations seen in UROtsa cells after acute arsenical exposure. To determine importance of ROS in the MAPK cascade and its downstream induction of p-Src and COX-2, specific ROS antioxidants (both enzymatic and non-enzymatic) were used concomitantly with arsenicals. COX-2 protein and mRNA was shown to be much more influenced by altering the levels of ROS in cells, particularly after MMA(III) treatment. The antioxidant enzyme superoxide dismutase (SOD) effectively blocked both As(III)-and MMA(III)- associated COX-2 induction. The generation of ROS and subsequent altered signaling did lead to changes in protein levels of SOD, which were detected after treatment with either 1 microM As(III) or 50 nM MMA(III). These data suggest that the generation of ROS by arsenicals may be a mechanism leading to the altered cellular signaling seen after low-level arsenical exposure.

Endocannabinoid 2-arachidonoylglycerol protects neurons by limiting COX-2 elevation

Endocannabinoids are involved in synaptic signaling and neuronal protection; however, our understanding of the mechanisms by which endocannabinoids protect neurons from harmful insults remains elusive. 2-Arachidonoylglycerol (2-AG), the most abundant endogenous cannabinoid and a full agonist for cannabinoid receptors (CB1 and CB2), is a substrate for cyclooxygenase-2 (COX-2) and can be metabolized by COX-2. Here we show, however, that 2-AG is also capable of suppressing elevation of hippocampal COX-2 expression in response to proinflammatory and excitotoxic stimuli. 2-AG prevents neurodegeneration from toxic assaults that elevate COX-2 expression and inhibits the COX-2 elevation-enhanced excitatory glutamatergic synaptic transmission. The action of 2-AG on suppression of COX-2 appeared to be mediated via the pertussis toxin-sensitive G protein-coupled CB1 receptor and MAPK/NF-kappaB signaling pathways. Our results reveal that 2-AG functions as an endogenous COX-2 inhibitor protecting neurons from harmful insults by preventing excessive expression of COX-2, which provides a mechanistic basis for opening up new therapeutic approaches for protecting neurons from inflammation- and excitotoxicity-induced neurodegeneration.

Isolation and characterization of phenolic compounds from the leaves of Salix matsudana

A bioassay-guided in vitro screen has revealed that a 70% methanol extract of the leaves of Salix matsudana shows considerable inhibitory activity against cyclooxygenases (COX-1 and COX-2). A subsequent phytochemical study led to the isolation of a new flavonoid, matsudone A (1), together with five known flavonoids--luteolin (2), isoquercitrin (3), 7-methoxyflavone (4), luteolin 7-O-glucoside (5), 4',7-dihydroxyflavone (6)--and two phenolic glycosides, leonuriside A (7) and piceoside (8). Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies, high resolution ESI mass spectroscopic analyses and comparisons with literature data. The isolated compounds 1-8 were tested for their inhibitory activities against COX-1 and COX-2. Compounds 1, 5 and 6 were found to have potent inhibitory effect on COX-2 and compounds 3-5 exhibited moderate inhibition against COX-1.

Inhibition of lipoxygenases and cyclooxygenase-2 enzymes by extracts isolated from Bacopa monniera (L.) Wettst

AIM OF THE STUDY

Bacopa monniera Linn is described in the Ayurvedic Materia Medica, as a therapeutically useful herb for the treatment of inflammation. In the current study, we investigated the anti-inflammatory activity of methanolic extract of Bacopa monniera (BME). For some experiments EtOAc and bacoside fractions were prepared from BME. The effect of these extracts in modulating key mediators of inflammation was evaluated.

MATERIALS AND METHODS

Carrageenan-induced rat paw edema, rat mononuclear cells and human whole blood assay were employed as in vivo and in vitro models.

RESULTS

In carrageenan-induced rat paw edema, BME brought about 82% edema inhibition at a dose of 100mg/kg i.p. when compared to indomethacin (INDO) (3mg/kg) that showed 70% edema inhibition. BME also significantly inhibited 5-lipoxygenase (5-LOX), 15-LOX and cyclooxygenase-2 (COX-2) activities in rat monocytes in vivo. Among the fractions tested in vitro, EtOAc fraction possessed significant 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with IC(50) value of 30 microg/ml compared to butylated hydroxyl toluene (IC(50) = 13 microg/ml). This fraction also exerted significant hydroxyl radical scavenging activity with IC(50) value of 25 microg/ml in comparison with quercetin (IC(50) = 5 microg/ml). Inhibitory effects of EtOAc and bacoside fractions on LOX and COX activities in Ca-A23187 stimulated rat mononuclear cells were also assessed. 5-LOX IC(50) values were 25 microg/ml for EtOAc, 68 microg/ml for bacosides and 2 microg/ml for nordihydroguaiaretic acid (NDGA) where as COX-2 IC(50) values were 1.32 microg/ml for EtOAc, 1.19 microg/ml for bacoside fraction and 0.23 microg/ml for indomethacin. EtOAc and bacoside fractions also brought about significant decrease in TNF-alpha release ex vivo.

CONCLUSION

Bacopa monniera possesses anti-inflammatory activity through inhibition of COX and LOX and downregulation of TNF-alpha.

Cyclooxygenase-2-derived endogenous prostacyclin reduces apoptosis and enhances embryo viability in mouse

The role of prostaglandins (PGs) in apoptosis in preimplantation mice embryo development is reported in this study. It is known that apoptosis plays a very important role in normal mice embryo development. Very few reports are available on this subject. Embryos (6-8 cells) were cultured in the presence of a selective cyclooxygenase (COX)1 inhibitor (SC560), a selective COX2 inhibitor (NS398) and a selective prostacyclin synthase (PGIS) inhibitor (U51605) in a 48-h culture. In another experiment, culture media were supplemented with prostaglandin E2 (PGE2) and prostaglandin I2 (PGI2 or prostacyclin) analogues. The apoptosis was evaluated by detection of active caspase-3. It was strongly detected in the presence of selective COX-2 and PGIS inhibitors, which can be decreased by a PGI2 analogue. In our embryo transfer experiment, the implantation rate decreased with exposure to either the COX2 or the PGIS inhibitor which is increased further after PGI2 supplementation. The level of PGI2 is also higher at the 8-16-cell stage, compaction and blastocyst stage than PGE2. All these results indicate that COX2-derived PGI2 plays an important role in preimplantation embryo development and acts as an antiapopetic factor in in vitro culture.

Anti-inflammatory activity of phylligenin, a lignan from the fruits of Forsythia koreana, and its cellular mechanism of action

AIM OF THE STUDY

The fruits of Forsythia koreana have long been used in Chinese medicine to treat inflammatory disorders. However, the pharmacological data is not sufficient to clearly establish a scientific rationale for the anti-inflammatory medicinal use of this plant material, and the search for its active principles has been limited so far.

MATERIALS AND METHODS

Phylligenin (lignan) was isolated from the fruits of Forsythia koreana and its anti-inflammatory activity was examined.

RESULTS AND CONCLUSION

Phylligenin (1-100 microM) and the methanol extract of Forsythia koreana fruits inhibited cyclooxygenase-2 (COX-2)-mediated prostaglandin E(2) and inducible nitric oxide synthase (iNOS)-mediated nitric oxide (NO) synthesis from lipopolysaccharide-treated RAW 264.7 cells. In the mechanism study, phylligenin inhibited iNOS expression and nuclear factor-kappaB (NF-kappaB) activation but had no effect on COX-2 expression. Moreover, phylligenin significantly inhibited mouse carrageenan-induced paw edema by intraperitoneal administration (22.1-34.7% inhibition at 12.5-100 mg/kg). These pharmacological properties indicate that phylligenin possesses significant anti-inflammatory activity in vitro and in vivo, and may provide the scientific rationale for anti-inflammatory use of the fruits of Forsythia koreana.

Monoglycerides from the brown alga Sargassum sagamianum: Isolation, synthesis, and biological activity

Polyunsaturated fatty acid-derived monoglycerides were characterized from the marine brown alga Sargassum sagamianum, collected from Jeju Island, Korea. A new compound of this structural class was isolated and determined to be 1-octadecatetraenoyl glycerol, by combined spectroscopic methods. Based on the structures and bioactivity of these compounds, a series of monoglycerides were synthesized using glycerol and various fatty acids. Several compounds exhibited moderate to significant inhibition of phospholipase A(2) and cyclooxygenase-2.

Intraprostatic botulinum toxin a injection inhibits cyclooxygenase-2 expression and suppresses prostatic pain on capsaicin induced prostatitis model in rat

PURPOSE

Cyclooxygenase-2 is a key enzyme in the conversion of arachidonic acid to prostaglandins, which are important mediators of inflammation and pain. We investigated the effect of intraprostatic botulinum toxin A administration on pain reaction and cyclooxygenase-2 expression in a capsaicin induced prostatitis model in rats.

MATERIALS AND METHODS

Adult male Sprague-Dawley rats were injected with vehicle or capsaicin (10 mM, 0.1 cc) into the prostate. The nociceptive effects of capsaicin were evaluated for 30 minutes using a behavior approach. The prostate and L6 spinal cord were then removed for histology and cyclooxygenase-2 expression using Western blotting or immunostaining. A second set of animals was injected with botulinum toxin A (5 to 20 U) into the prostate 1 week before intraprostatic injection of capsaicin.

RESULTS

Capsaicin induced increased pain behavior and inflammatory reaction. Botulinum toxin A 1 week before treatment dose dependently decreased inflammatory cell accumulation, cyclooxygenase-2 expression and prostatic pain. Botulinum toxin A (20 U) significantly decreased inflammatory cell accumulation, and cyclooxygenase-2 expression in the prostate, ventral horn and dorsal horn of the L6 spinal cord (93.5%, 89.4%, 90.5% and 77.5%, respectively). It decreased pain behavior for eye and locomotion scores (59.5% and 40.0%, respectively).

CONCLUSIONS

Intraprostatic capsaicin injection activates cyclooxygenase-2 expression in the prostate, and spinal sensory and motor neurons, and it induces prostatic pain. Botulinum toxin A pretreatment could inhibit capsaicin induced cyclooxygenase-2 expression from the peripheral organ to the L6 spinal cord and inhibit prostatic pain and inflammation. This finding suggests a potential clinical benefit of botulinum toxin A for the treatment of nonbacterial prostatitis.

Effect of chondroitin sulphate in a rabbit model of atherosclerosis aggravated by chronic arthritis

BACKGROUND AND PURPOSE

Among the agents employed to manage osteoarthritis, chondroitin sulphate (CS) is a natural glycosaminoglycan with an anti-inflammatory effect on joint cells. CS might also influence the inflammatory component of atherosclerosis. Our aim was to examine the effect of CS administration on vascular injury and on markers of systemic inflammation in a rabbit model of atherosclerosis aggravated by systemic inflammation provoked by chronic antigen-induced arthritis.

EXPERIMENTAL APPROACH

Atherosclerosis was induced in rabbits by maintaining them on a hyperlipidaemic diet after producing an endothelial lesion in the femoral arteries. Simultaneously, chronic arthritis was induced in these animals by repeated intraarticular injections of ovalbumin in previously immunized rabbits. A group of these rabbits were treated prophylactically with CS (100 mg kg(-1)day(-1)) and when the animals were killed, serum and peripheral blood mononuclear cells (PBMC) were isolated. Furthermore, femoral arteries and thoracic aorta were used for gene expression studies and histological examination.

KEY RESULTS

CS administration reduced the concentration of the proinflammatory molecules C-reactive protein and IL-6 in serum. Likewise, CS inhibited the expression of CCL2/monocyte chemoattractant protein (MCP)-1 and cyclooxygenase (COX)-2 in PBMC, and reduced the nuclear translocation of nuclear factor-kappaB. In the femoral lesion, CS also diminished the expression of CCL2 and COX-2, as well as the ratio of the intima/media thickness. Moreover, CS decreased the percentage of rabbits with atherosclerosis and chronic arthritis that developed vascular lesions in the aorta.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that CS treatment may to some extent impede the progression of atherosclerosis.

Selective increase of neuronal cyclooxygenase-2 (COX-2) expression in vulnerable brain regions of rats with experimental Wernicke's encephalopathy: effect of nimesulide

Thiamine deficiency (TD) in both humans and experimental animals results in severe mitochondrial dysfunction and leads to selective neuronal cell death in diencephalic and cerebellar structures. We have investigated cyclooxygenase-2 (COX-2) expression in vulnerable (medial thalamus, inferior colliculus) and spared (frontal cortex) regions of rats with thiamine deficiency. Expression of COX-2 mRNA was selectively increased (twofold, p < 0.001) in vulnerable regions at symptomatic stages of encephalopathy (14 days) of TD compared to pair-fed controls or presymptomatic (days 12) rats. Induction of COX-2 expression was accompanied by a significant increase (two- to threefold, p < 0.001) in prostanglandin E2 (PGE2) synthesis in vulnerable regions at symptomatic stages of TD. COX-2 immunolabeling revealed a neuronal localization and COX-2 immunoreactive neurons were significantly increased at symptomatic stages of encephalopathy. Administration of nimesulide, a highly specific COX-2 inhibitor, significantly reduced PGE-2 levels in vulnerable regions but, rather than being neuroprotective, precipitated encephalopathy and exacerbated neuronal cell death due to TD. These findings suggest that newly synthesized prostanoids exert a neuroprotective role in TD.

Ameliorative prospective of alpha-mangostin, a xanthone derivative from Garcinia mangostana against beta-adrenergic cathecolamine-induced myocardial toxicity and anomalous cardiac TNF-alpha and COX-2 expressions in rats

Altered membrane integrity and inflammation play a key role in cardiovascular damage. We investigated the salubrious effect of exogenously administered alpha-mangostin against beta-adrenergic cathecolamine-induced cardiovascular toxicity with special reference to membrane ATPases, lysosomal hydrolases and inflammatory mediators TNF-alpha and Cyclooxygenase-2 (COX-2) expressions in albino rats. Induction of rats with isoproterenol (150mg/kg body wt, i.p.) for 2 days resulted in a significant increase in the activities of serum and cardiac lysosomal hydrolases (beta-d-glucuronidase, beta-d-galactosidase, beta-d-N-acetylglucosaminidase, acid phosphatase and cathepsin-D). A significant increase in cardiac levels of sodium, calcium with a decrease in the level of potassium paralleled by abnormal activities of membrane-bound phosphatases (Na(+)-K(+) ATPase, Ca(2+) ATPase and Mg(2+) ATPase) were observed in the heart of ISO-administered rats. Cardiac TNF-alpha and COX-2 expressions were assessed by Western blotting. Cardiac TNF-alpha and COX-2 expressions were significantly elevated in ISO-intoxicated rats. Pre-co-treatment with alpha-mangostin (200mg/kg body wt.) orally for 8 days significantly attenuated these abnormalities and restored the levels to near normalcy when compared to ISO intoxicated group of rats. In conclusion, alpha-mangostin preserves the myocardial membrane integrity and extenuates anomalous TNF-alpha and COX-2 expressions by mitigating ISO-induced oxidative stress and cellular damage effectively. Restoration of cellular normalcy accredits the cytoprotective role of alpha-mangostin.

Bupivacaine inhibits COX-2 expression, PGE2, and cytokine production in endotoxin-activated macrophages

BACKGROUND

Upregulation of cyclooxygenase-2 (COX-2) and resultant prostaglandin E(2) (PGE(2)) overproduction has been shown to play a crucial role in initiating a systemic inflammatory response during sepsis. Sepsis also induces robust production of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 as well as anti-inflammatory cytokine IL-10. We sought to elucidate the effects of bupivacaine on COX-2 expression and production of PGE(2) and cytokines using an endotoxin-activated murine macrophages model.

METHODS

Confluent murine macrophages (RAW264.7 cells) were treated with lipopolysaccharide (LPS, 100 ng/ml) or LPS plus bupivacaine (1, 10, or 100 microM). Bupivacaine was added immediately after LPS. After reacting for 18 h, cell cultures were harvested for subsequent analysis.

RESULTS

LPS significantly upregulated COX-2 transcription and PGE(2) production in macrophages. LPS also significantly increased the production of TNF-alpha, IL-1beta, IL-6 and IL-10 in macrophages. Bupivacaine significantly inhibited the effects of LPS on COX-2 transcription and PGE(2) production in a dose-dependent manner. In a dose-dependent manner, bupivacaine also significantly inhibited the effects of LPS on the production of TNF-alpha, IL-1beta, and IL-6. However, bupivacaine exerted no significant effects on LPS-induced IL-10 production.

CONCLUSION

Bupivacaine significantly inhibited COX-2 expression, PGE(2) and cytokine production in endotoxin-activated macrophages.