Induction of cyclo-oxygenase and nitric oxide synthase in inflammation

TNF-α/IL-1β-licensed hADSCs alleviate cholestatic liver injury and fibrosis in mice via COX-2/PGE2 pathway

BACKGROUND

Adipose tissue-derived stem cell (ADSC) transplantation has been shown to be effective for the management of severe liver disorders. Preactivation of ADSCs enhanced their therapeutic efficacy. However, these effects have not yet been examined in relation to cholestatic liver injury.

METHODS

In the present study, a cholestatic liver injury model was established by bile duct ligation (BDL) in male C57BL/6 mice. Human ADSCs (hADSCs) with or without tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) pretreatment were administrated into the mice via tail vein injections. The efficacy of hADSCs on BDL-induced liver injury was assessed by histological staining, real-time quantitative PCR (RT-qPCR), Western blot, and enzyme-linked immune sorbent assay (ELISA). In vitro, the effects of hADSC conditioned medium on the activation of hepatic stellate cells (HSCs) were investigated. Small interfering RNA (siRNA) was used to knock down cyclooxygenase-2 (COX-2) in hADSCs.

RESULTS

TNF-α/IL-1β preconditioning could downregulate immunogenic gene expression and enhance the engraftment efficiency of hADSCs. Compared to control hADSCs (C-hADSCs), TNF-α/IL-1β-pretreated hADSCs (P-hADSCs) significantly alleviated BDL-induced liver injury, as demonstrated by reduced hepatic cell death, attenuated infiltration of Ly6G + neutrophils, and decreased expression of pro-inflammatory cytokines TNF-α, IL-1β, C-X-C motif chemokine ligand 1 (CXCL1), and C-X-C motif chemokine ligand 2 (CXCL2). Moreover, P-hADSCs significantly delayed the development of BDL-induced liver fibrosis. In vitro, conditioned medium from P-hADSCs significantly inhibited HSC activation compared to that from C-hADSCs. Mechanistically, TNF-α/IL-1β upregulated COX-2 expression and increased prostaglandin E2 (PGE2) secretion. The blockage of COX-2 by siRNA transfection reversed the benefits of P-hADSCs for PGE2 production, HSC activation, and liver fibrosis progression.

CONCLUSION

In conclusion, our results suggest that TNF-α/IL-1β pretreatment enhances the efficacy of hADSCs in mice with cholestatic liver injury, partially through the COX-2/PGE2 pathway.

Blood Coral Polysaccharide Helps Prevent D-Gal/LPS-Induced Acute Liver Failure in Mice

Objective

The liver protection of blood coral polysaccharide (BCP) was investigated.

Materials and Methods

We evaluated the effect of BCP on liver pathology, liver function, oxidation and inflammation-related indicators of D-Gal/LPS-induced acute liver failure (ALF) mice in vivo.

Results

Liver index and liver pathology observation in mice showed that BCP could inhibit liver tissue swelling and hemorrhage, hepatocyte damage, and inflammatory infiltration in ALF. Serum liver function results showed that BCP effectively inhibits the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), total bilirubin (TBil), alkaline phosphatase (AKP), myeloperoxidase (MPO). High dose-blood coral polysaccharide (H-BCP) was better than silymarin. Serum antioxidant and immune results showed that BCP increased the levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GSH-Px), and inhibited the levels of malondialdehyde (MDA) and nitric oxide (NO). Also, BCP increased immunoglobulins G (IgG) and A (IgA) levels, thereby enhancing humoral immunity. Liver anti-inflammatory ELISA results showed that BCP reduced the levels of interleukin (IL)-6, IL-1β, IL-17, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, and enhanced the level of anti-inflammatory factor IL-10. H-BCP was the most effective treatment. Real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) of liver tissues confirmed that BCP increases the relative expression levels of antioxidant and anti-inflammatory-related cuprozinc superoxide dismutase (Cu/Zn-SOD, SOD1), manganese superoxide dismutase (Mn-SOD, SOD2), CAT, GSH, GSH-Px, and IL-10. In contrast, it inhibits inflammation-related genes IL-6, IL-1β, IL-17, TNF-α, IFN-γ, inducible nitric oxide synthase (iNOS, NOS2), and cyclooxygenase (COX)-2. In addition, BCP also inhibits the nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and enhance B-cell inhibitor-α (IκB-α) gene relative expression in the liver, which may be related to NF-κB pathway inhibition.

Conclusion

BCP prevents D-Gal/LPS-induced ALF in mice, and its effect is concentration dependent.

Anti-Inflammatory Effect of Adipose-Derived Stromal Vascular Fraction on Osteoarthritic Temporomandibular Joint Synoviocytes

BACKGROUND

Osteoarthritis (OA) in the temporomandibular joint (TMJ) in the TMJ (TMJ-OA) is difficult to treat, and new alternative treatments are needed. Recently, adipose-derived stem cells (ASCs) have been introduced as a promising cell source because of their anti-inflammatory effects. However, the cost and availability of these cells limited broader applications of stem cell therapy. Thus, Thus, stromal vascular fraction (SVF) containing sufficient amount of ASCs at low cost can be an alternative. In this study, we aimed to demonstrate the use of uncultured, optimally isolated SVF for the treatment of TMJ-OA.

METHODS

First, we optimized the method of isolation to harvest high-quality SVFs with a large yield of ASCs. Then, we analyzed the quantity of ASCs in the SVF and performed characterization of stem cell homology. Subsequently, to evaluate the anti-inflammatory effect of high-quality SVF, an in vitro study was performed to assess the expression patterns of inflammatory cytokines including prostaglandin E₂ (PGE₂), IL-6, and CXCL8/IL-8, COX2, TNF, IFN, CCL2/MCP-1 and CCL5/RANTES in co-culture with synoviocytes derived from the synovial fluid in the TMJ-OA patients.

RESULTS

The SVF containing approximately 32% ASCs was isolated via the our optimized isolation method. The SVF significantly down-regulated certain inflammatory cytokines such as PGE2, CXCL8/IL-8 in TMJ-OA tissue-derived synoviocytes.

CONCLUSION

Although further study is needed, our study suggests that transplantation of adipose tissue-derived SVF cells might be a feasible and a novel therapeutic option for TMJ-OA in the future.

Human Peritoneal Mesothelial Cells Produce Nitric Oxide: Induction by Cytokines

Objective

To investigate the induction of nitric oxide synthase type II (iNOS) in human peritoneal mesothelial cells (HPMC) using cytokines and bacterial lipopolysaccharide (LPS).

Design

Confluent monolayers of HPMC were exposed to cytokines [tumor necrosis factor alpha (TNFα), interleukin-1 beta (IL-1β), interferon gamma (IFNγ)] or LPS, individually or in various double and triple combinations, for 24 – 72 hours. Concentrations of nitrate and nitrite in the media were quantified using the Griess reaction and used as indirect indices of nitric oxide (NO) production. The expression of iNOS was assessed using reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot.

Results

Neither single cytokines nor LPS was able to induce iNOS mRNA or NO production. Both double combinations of TNFα+ IFNγ and IL-1β + IFNγ were able to induce iNOS mRNA expression, but only TNFα + IFNγ induced significant NO production. The triple combination of TNFα + IFNγ + IL-1β induced even more NO production than TNFα + IFNγ. There was no constitutive NO synthase type III (eNOS) expression in HPMC.

Conclusions

Certain combinations of cytokines could stimulate cultured HPMC to produce NO, and HPMC might be a source of intraperitoneal NO production during peritonitis.

Sodium Butyrate Exerts Neuroprotective Effects in Spinal Cord Injury

Sodium butyrate (SB) is a dietary microbial fermentation product and serves as an important neuromodulator in the central nervous system. Recent experimental evidence has suggested potential therapeutic applications for butyrate, including its utility in treating metabolic and inflammatory diseases. The aim of the present study was to evaluate the potential beneficial effects of SB in a mouse model of spinal cord injury (SCI) and its possible mechanism of action. SCI was induced by extradural compression for 1 min of the spinal cord at the T6-7 level using an aneurysm clip, and SB (10-30-100 mg/kg) was administered by oral gavage 1 and 6 h after SCI. For locomotor activity, study mice were treated with SB once daily for 10 days. Morphological examination was performed by light microscopy through hematoxylin-eosin (H&E) staining. In addition, NF-κB, IκB-α, COX-2, and iNOS expressions were assayed by western blot analysis and IL-1β and TNF-α levels by immunohistochemistry analysis. The results showed that SB treatment significantly ameliorated histopathology changes and improved recovery of motor function changes in spinal cord injury in a dose-dependent manner. Moreover, we demonstrated that SB modulated the NF-κB pathway showing a significant reduction in cytokine expression. Thus, this study showed that SB exerts neuroprotective effects anti-inflammatory properties following spinal cord injury suggesting that SB may serve as a potential candidate for future treatment of spinal cord injury.

The Peptidylarginine Deiminase Inhibitor Cl-Amidine Suppresses Inducible Nitric Oxide Synthase Expression in Dendritic Cells

The conversion of peptidylarginine into peptidylcitrulline by calcium-dependent peptidylarginine deiminases (PADs) has been implicated in the pathogenesis of a number of diseases, identifying PADs as therapeutic targets for various diseases. The PAD inhibitor Cl-amidine ameliorates the disease course, severity, and clinical manifestation in multiple disease models, and it also modulates dendritic cell (DC) functions such as cytokine production, antigen presentation, and T cell proliferation. The beneficial effects of Cl-amidine make it an attractive compound for PAD-targeting therapeutic strategies in inflammatory diseases. Here, we found that Cl-amidine inhibited nitric oxide (NO) generation in a time- and dose-dependent manner in maturing DCs activated by lipopolysaccharide (LPS). This suppression of NO generation was independent of changes in NO synthase (NOS) enzyme activity levels but was instead dependent on changes in inducible NO synthase (iNOS) transcription and expression levels. Several upstream signaling pathways for iNOS expression, including the mitogen-activated protein kinase, nuclear factor-κB p65 (NF-κB p65), and hypoxia-inducible factor 1 pathways, were not affected by Cl-amidine. By contrast, the LPS-induced signal transducer and the activator of transcription (STAT) phosphorylation and activator protein-1 (AP-1) transcriptional activities (c-Fos, JunD, and phosphorylated c-Jun) were decreased in Cl-amidine-treated DCs. Inhibition of Janus kinase/STAT signaling dramatically suppressed iNOS expression and NO production, whereas AP-1 inhibition had no effect. These results indicate that Cl-amidine-inhibited STAT activation may suppress iNOS expression. Additionally, we found mildly reduced cyclooxygenase-2 expression and prostaglandin E2 production in Cl-amidine-treated DCs. Our findings indicate that Cl-amidine acts as a novel suppressor of iNOS expression, suggesting that Cl-amidine has the potential to ameliorate the effects of excessive iNOS/NO-linked immune responses.

Modifying effect of intravenous laser therapy on the protein expression of arginase and epidermal growth factor receptor in type 2 diabetic patients

The epidermal growth factor receptor (EGFR) signaling pathway may be involved in cell activation and may influence the neuronal microenvironment, microglia activation, and production of proinflammatory cytokines. Arginase and nitric oxide synthase (NOS) both use L-arginine as a common substrate. Decreasing the arginase expression may increase L-arginine consumption by NOS and increase nitric oxide (NO) synthesis. Intravenous laser blood irradiation (ILBI) is an effective systemic treatment for different pathologies including diabetes mellitus. Previous studies have shown that low-level laser therapy can have an effect on the release of certain cytokines and growth factors. The aim of this study was to evaluate the effects of ILBI on the expression of arginase and epidermal growth factor receptor in type 2 diabetic patients. We used 630 nm red laser light, 1.5 mW, continuous mode, intravenously for 30 min in 13 type 2 diabetic patients and compared their blood samples using the flow cytometry technique, before and after ILBI. The difference between the percentage of cells before and after therapy was analyzed using repeated-measures ANOVA, and the relationship between EGFR and arginase expression in blood and tissue was evaluated by calculating the Pearson correlation coefficient. We found a significant decrease in the expression of both arginase- and EGFR-positive cells after laser therapy (P < 0.01). In conclusion, laser therapy may have a beneficial effect for diabetic patients via decreasing arginase expression and activation of the NOS/NO pathway which increases NO production and vasodilation, and decreasing EGFR expression which may reduce neuroinflammation and its secondary damages.

Adipose-derived mesenchymal stem cells exert antiinflammatory effects on chondrocytes and synoviocytes from osteoarthritis patients through prostaglandin E2

OBJECTIVE

To examine the effect of different sources of good manufacturing practice clinical grade adipose-derived mesenchymal stem cells (AD-MSCs) on inflammatory factors in osteoarthritic (OA) chondrocytes and synoviocytes.

METHODS

AD-MSCs from infrapatellar Hoffa fat, subcutaneous (SC) hip fat, and SC abdominal fat were cocultured in Transwells with chondrocytes or synoviocytes. Inflammatory factors (interleukin-1β [IL-1β], tumor necrosis factor α, IL-6, CXCL1/growth-related oncogene α, CXCL8/IL-8, CCL2/monocyte chemotactic protein 1, CCL3/macrophage inflammatory protein 1α, and CCL5/RANTES) were evaluated by quantitative reverse transcription-polymerase chain reaction or multiplex bead-based immunoassay. The role of different immunomodulators was analyzed.

RESULTS

All the inflammatory factors analyzed were down-modulated at the messenger RNA or protein level independently by all 3 AD-MSC sources or by allogeneic AD-MSCs used in coculture with chondrocytes or synoviocytes. Inflammatory factor down-modulation was observed only when AD-MSCs were cocultured with chondrocytes or synoviocytes that produced high levels of inflammatory factors, but no effect was observed in cells that produced low levels of those factors, thus highlighting a dependence of the AD-MSC effect on existing inflammation. The immunomodulators IL-10, IL-1 receptor antagonist, fibroblast growth factor 2, indoleamine 2,3-dioxygenase 1, and galectin 1 were not involved in AD-MSC effects, whereas the cyclooxygenase 2 (COX-2)/prostaglandin E2 (PGE2 ) pathway exerted a role in the mechanism of antiinflammatory AD-MSC action.

CONCLUSION

The antiinflammatory effects of AD-MSCs are probably not dependent on AD-MSC adipose tissue sources and donors but rather on the inflammatory status of OA chondrocytes and synoviocytes. AD-MSCs seem to be able to sense and respond to the local environment. Even though a combination of different molecules may be involved in AD-MSC effects, the COX-2/PGE2 pathway may play a role, suggesting that AD-MSCs may be useful for therapies in osteoarticular diseases.

Melatonin treatment following stroke induction modulates L-arginine metabolism

The efficacy of melatonin treatment in experimental stroke has been established. Some of the neuroprotective properties have been attributed to its anti-oxidant and anti-inflammatory effects. Nitric oxide synthases (NOS) and cyclooxygenases (COX) are considered to have a significant role in the inflammatory milieu occurring in acute stroke. While previous reports have shown that pretreatment with melatonin in a stroke model can modulate NOS isoforms, the effect of post-treatment with melatonin on l-arginine metabolism has not been investigated. This study initially examined the effect of melatonin (1 nm-1 mm) on l-arginine metabolism pathways in human fibrosarcoma fibroblasts (HT-1080) fibroblasts. Evidence of neuroprotection with melatonin was evaluated in rats subjected to middle cerebral artery occlusion (MCAO). Animals were treated with three daily doses of 5 mg/kg i.p., starting 1 hr after the onset of ischemia. Constitutive NOS activity but not expression was significantly increased by in vitro exposure (72 hr) to melatonin. In addition, melatonin treatment increased arginase activity by increasing arginase II expression. In vivo studies showed that melatonin treatment after MCAO significantly inhibited inducible NOS activity and attenuated expression of the inducible isoform, resulting in decreased total NOS activity and tissue nitrite levels. COX activity was significantly reduced with melatonin treatment. The neuroprotective anti-inflammatory effects of melatonin were consistent with the substantial reduction in infarct volume throughout the cortex and striatum and recovery of mitochondrial enzyme activities. The evidence presented here suggests that modulation of l-arginine metabolism by melatonin make it a valuable neuroprotective therapy for stroke.

Involvement of inducible nitric oxide synthase and cyclooxygenase-2 in the anti-inflammatory effects of a red orange extract in human chondrocytes

In the present study, a complex of compounds (red orange complex, ROC), obtained from three red orange varieties (Citrus sinensis varieties: Moro, Tarocco and Sanguinello), containing cyanidin glycosides, hydroxycinnamic acids, flavanone glycosides and ascorbic acid, was screened to discover new lead compounds in the suppression of the production of key molecules released during inflammatory events in interleukin-1beta (IL-beta) stimulated human primary chondrocytes. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX)-2 and intercellular adhesion molecule-1 (ICAM-1), and the release of nitric oxide, prostaglandin (PG)E(2) and interleukin-8 (IL-8) were determined. Indomethacin was used as an anti-inflammatory drug reference. ROC acts as a potent inhibitor of iNOS and COX-2 gene expression while also suppressing the production of PGE(2) and nitrite in human chondrocytes. In addition, ROC induces a significant decrease in ICAM expression and IL-8 release. These findings suggest that ROC exerts anti-inflammatory effects probably through the suppression of COX-2 and iNOS expression.

Suppression of ongoing experimental arthritis by a chinese herbal formula (huo-luo-xiao-ling dan) involves changes in antigen-induced immunological and biochemical mediators of inflammation

Rheumatoid arthritis (RA) is one of the major autoimmune diseases of global prevalence. The use of the anti-inflammatory drugs for the treatment of RA is associated with severe adverse reactions and toxicity. This limitation has necessitated the search for novel therapeutic products. We report here a traditional Chinese medicine-based herbal formula, Huo luo xiao ling dan (HLXL), which has potent antiarthritic activity as validated in the rat adjuvant-induced arthritis (AA) model. HLXL (2.3 g/Kg) was fed to Lewis (RT.1(1)) rats daily by gavage beginning at the onset of arthritis and then continued through the observation period. HLXL inhibited the severity of ongoing AA. This suppression of arthritis was associated with significant alterations in the T cell proliferative and cytokine responses as well as the antibody response against the disease-related antigen, mycobacterial heat-shock protein 65 (Bhsp65). There was a reduction in the level of the proinflammatory cytokines IL-17 and IL-1β but enhancement of the anti-inflammatory cytokine IL-10 level. In addition, there was inhibition of both the anti-Bhsp65 antibody response and the serum level of nitric oxide. Thus, HLXL is a promising CAM modality for further testing in RA patients.

Chronic infection during placental malaria is associated with up-regulation of cycloxygenase-2

BACKGROUND

Placental malaria (PM) is associated with poor foetal development, but the pathophysiological processes involved are poorly understood. Cyclooxygenase (COX) and lipoxygenase (LOX) which convert fatty acids to prostaglandins and leukotrienes, play important roles in pregnancy and foetal development. COX-2, currently targeted by specific drugs, plays a dual role as it associates with both pre-eclampsia pathology and recovery during infection. The role of COX during PM was questioned by quantifying at delivery COX-1, COX-2, 15-LOX, and IL-10 expression in two groups of malaria infected and uninfected placenta.

METHODS

Placental biopsies were collected at delivery for mRNA isolation and quantification, using real time PCR.

RESULTS

COX-2 and IL-10 mRNAs increased mainly during chronic infections (nine- and five-times, respectively), whereas COX-1 transcripts remained constant. COX-2 over-expression was associated with a higher birth weight of the baby, but with a lower rate of haemoglobin of the mother. It was associated with a macrophage infiltration of the placenta and with a low haemozoin infiltration. In the opposite way, placental infection was associated with lower expression of 15-LOX mRNA. A high degree of haemozoin deposition correlates with low birth weight and decreased expression of COX-2.

CONCLUSION

These data provide evidence that COX-2 and IL-10 are highly induced during chronic infection of the placenta, but were not associated with preterm delivery or low birth weight. The data support the involvement of COX-2 in the recovery phase of the placental infection.

Thalidomide inhibits inflammatory and angiogenic activation of human intestinal microvascular endothelial cells (HIMEC)

The glutamic acid derivative thalidomide is a transcriptional inhibitor of TNF-alpha but is also known to affect human blood vessels, which may underlie its teratogenicity. Thalidomide has been used in the treatment of refractory Crohn's disease (CD), but the therapeutic mechanism is not defined. We examined the effect of thalidomide on primary cultures of human intestinal microvascular endothelial cells (HIMEC), the relevant endothelial cell population in inflammatory bowel disease (IBD), to determine its effect on endothelial activation, leukocyte interaction, and VEGF-induced angiogenesis. HIMEC cultures were pretreated with thalidomide before activation with either TNF-alpha/LPS or VEGF. A low-shear-stress flow adhesion assay with either U-937 or whole blood was used to assess HIMEC activation following TNF-alpha/LPS, and a Wright's stain identified adherent leukocytes. Expression of cell adhesion molecules (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) was assessed using radioimmunoassay. Effects of thalidomide on NF-kappaB activation, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) expression in TNF-alpha/LPS-activated HIMEC were determined by RT-PCR and Western blotting. Thalidomide blocked adhesion of both U-937 and whole blood leukocytes by 50% in HIMEC, inhibiting binding of all classes of leukocytes. Thalidomide also blocked NF-kappaB and cell adhesion molecule expression in HIMEC. In marked contrast, thalidomide did not affect either iNOS or COX-2 expression, two key molecules that play a role in the downregulation of HIMEC activation. VEGF-induced HIMEC transmigration, growth, proliferation, tube formation, and Akt phosphorylation were significantly inhibited by thalidomide. In summary, thalidomide exerted a potent effect on HIMEC growth and activation, suggesting that it may also function via an endothelial mechanism in the treatment of CD.

Reduced skin inflammatory response in mice lacking inducible nitric oxide synthase

The skin is the largest organ in the body and one of its main functions is to protect the body from environmental and endogenous noxious conditions, such as injury, infection and inflammation. The inducible nitric oxide synthase (iNOS) has been implicated as a key component in the inflammatory response. In the present study, we assessed the role of iNOS in the skin inflammation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Mice deficient in iNOS had reduced edema and cellular infiltration in the skin following topical TPA application. Moreover, the genetic blockage of iNOS signaling inhibited the TPA-induced ERK and p38 activation resulting in reduced COX-2 upregulation. Finally, immunohistochemical studies revealed that iNOS knockout mice exhibited marked inhibition of AP-1, CREB and NF-kappaB transcriptional factors activation. Together, these results indicate that TPA induces the activation of several iNOS-dependent intracellular signaling pathways that have a key role in the control of inflammatory response in the skin. Therefore, selective iNOS inhibitors may be potentially relevant tools for cutaneous skin disease drug development.

The degradation of glycosaminoglycans by intestinal microflora deteriorates colitis in mice

The biosynthesis and modification of mucopolysaccharides and glycosaminoglycans (GAGs), secreted from gastrointestinal mucosal cells, are increased in colitis and influence the viability of the defense barrier. Therefore, to evaluate the role of GAG-degrading intestinal microflora during the progression of colitis, we investigated the degradation activity of intestinal bacterial GAG, cytotoxicity of GAGs and their metabolites, such as iduronic acid, D: -uronic acid or D: -glucuronic acid and D: -galactosamine or D: -glucosamine, against intestinal cells. We also tested their deteriorative effects against colitis. Colitis was induced using 2,4,6-trinitrobenzene sulfonic acid (TNBS) with and without antibiotics in mice. The TNBS treatment caused colon shortening, increased myeloperoxidase activity, induced IL-1beta, TNF-alpha, and IL-6 expression in the colon, activated NF-kappaB, and potentiated the GAG-degrading activities of intestinal microflora. The antibiotic treatment inhibited colon shortening, decreased myeloperoxidase activity, and reduced proinflammatory cytokine expression, NF-kappaB activation, and GAG degradation, induced by TNBS. Among the GAG metabolites, d-glucosamine and d-galactosamine showed cytotoxicity against intestinal cells, Caco-2 and IEC-18 cells, synergistically deteriorated the cytotoxicity of TNBS as well as the TNBS-induced colitis in mice. Based on these findings, intestinal microflora may degrade GAGs in colitis, their metabolites deteriorate the progress of colitis and antibiotics ameliorate the colitis by the inhibition of GAG-degrading bacterial growth.

Physalis angulata extract exerts anti-inflammatory effects in rats by inhibiting different pathways

Physalis angulata is a popular medicine used in Brazil due to its anti-inflammatory effects, but the pharmacological mechanisms underlying these actions remain to be better understood. In the present work, lyophilized aqueous extract from the roots of Physalis angulata Linneu (AEPa) was used to control the inflammatory response induced by the injection of 1% carrageenan into subcutaneous rat's air pouches. Adenosine deaminase (ADA) activity, nitrite level, and prostaglandin E(2) (PGE(2)) level were used to evaluate the action of inflammatory mediators. Tumor growth factor-beta (TGF-beta) level was used as a bioindicator of immunomodulatory response. Rats were injected with vehicle, indomethacin, or AEPa (0.5 mg/kg, 1 mg/kg, and 5 mg/kg i.p.), 1h before carrageenan administration. AEPa at 0.5 mg/kg had no effect. However, 1mg/kg of AEPa showed significant anti-inflammatory effects, decreasing exudate volume, total number of inflammatory cells, ADA activity, nitrite level, and PGE(2) level in 50%, 41%, 20%, 60%, and 41%, respectively. The anti-inflammatory effects of 5 mg/kg AEPa appeared to be more effective than those of 1 mg/kg AEPa (84%, 80%, 43%, 70%, and 75%, respectively). In addition, TGF-beta level was upregulated to 9700 pg/ml after 5mg/kg AEPa, in comparison with 160 pg/ml in the vehicle-treated group, and 137 pg/ml in the indomethacin-treated group. The results indicate that AEPa exerts powerful anti-inflammatory and immunomodulatory activities, interfering with the cyclooxygenase pathway, lymphocyte proliferation, NO, and TGF-beta production.

Celastrus aculeatus Merr. suppresses the induction and progression of autoimmune arthritis by modulating immune response to heat-shock protein 65

Complementary and alternative medicine products are increasingly being used for the treatment of autoimmune diseases. However, the mechanisms of action of these agents are not fully defined. Using the rat adjuvant arthritis (AA) model of human rheumatoid arthritis, we determined whether the ethanol extract of Celastrus aculeatus Merr. (Celastrus), a Chinese herb, can down-modulate the severity of AA, and also examined the Celastrus-induced changes in immune responses to the disease-related antigen mycobacterial heat-shock protein 65 (Bhsp65). AA was induced in the Lewis (LEW; RT.1^l) rat by immunization subcutaneously with heat-killed M. tuberculosis H37Ra (Mtb). Celastrus was fed to LEW rats by gavage daily, beginning either before Mtb challenge (preventive regimen) or after the onset of AA (therapeutic regimen). An additional group of rats was given methotrexate for comparison. All rats were graded regularly for the signs of arthritis. In parallel, the draining lymph node cells of Celastrus-treated rats were tested for proliferative and cytokine responses, whereas their sera were tested for the inflammatory mediator nitric oxide. Celastrus feeding suppressed both the induction as well as the progression of AA, and the latter effect was comparable to that of methotrexate. Celastrus treatment induced relative deviation of the cytokine response to anti-inflammatory type and enhanced the production of anti-Bhsp65 antibodies, which are known to be protective against AA. Celastrus feeding also reduced the levels of nitric oxide. On the basis of our results, we suggest further systematic exploration of Celastrus as an adjunct therapeutic modality for rheumatoid arthritis.

Lactic acid bacteria inhibit proinflammatory cytokine expression and bacterial glycosaminoglycan degradation activity in dextran sulfate sodium-induced colitic mice

To evaluate the effect of lactic acid bacteria (LAB) in inflammatory bowel diseases (IBD), inhibitory effect of several LAB isolated from intestinal microflora and commercial probiotics against NO production of lipopolysaccharide (LPS)-stimulated RAW264.7 cells was measured and anti-inflammatory effect of NO production-inhibitory LAB, Lactobacillus plantarum HY115 and L. brevis HY7401, in dextran sulfate sodium (DSS)-induced experimental colitic mice was investigated. The oral administration of the LAB to mice inhibited colon shortening and myeloperoxidase productivity in DSS-induced colitic mice. These LABs repressed the mRNA expressions of IL-1beta, TNF-alpha and IFN-gamma, as well as the protein expressions of IL-1beta and IL-6 proteins in the colon. The activation of the transcription factor, NF-kB, induced by DSS, was also inhibited by LAB. The administration of LAB reduced the degradation activities of chondroitin sulfate and hyaluronic acid of intestinal bacteria, induced by DSS, of which could induce the cytotoxic metabolites against intestinal cells. These findings suggest that NO-inhibitory LAB against LPS-stimulated RAW264.7 cells may improve colitis by the regulation of the inflammatory cytokine expression via the activation of transcription factor NF-kB as well as GAGs-degrading intestinal microflora.

The role of nitric oxide in inflammatory reactions

Nitric oxide (NO) was initially described as a physiological mediator of endothelial cell relaxation, an important role in hypotension. NO is an intercellular messenger that has been recognized as one of the most versatile players in the immune system. Cells of the innate immune system--macrophages, neutrophils and natural killer cells--use pattern recognition receptors to recognize the molecular patterns associated with pathogens. Activated macrophages then inhibit pathogen replication by releasing a variety of effector molecules, including NO. In addition to macrophages, a large number of other immune-system cells produce and respond to NO. Thus, NO is important as a toxic defense molecule against infectious organisms. It also regulates the functional activity, growth and death of many immune and inflammatory cell types including macrophages, T lymphocytes, antigen-presenting cells, mast cells, neutrophils and natural killer cells. However, the role of NO in nonspecific and specific immunity in vivo and in immunologically mediated diseases and inflammation is poorly understood. This Minireview will discuss the role of NO in immune response and inflammation, and its mechanisms of action in these processes.

Bovine herpesvirus 4 is tropic for bovine endometrial cells and modulates endocrine function

Bovine postpartum uterine disease, metritis, affects about 40% of animals and is widely considered to have a bacterial aetiology. Although the gamma-herpesvirus bovine herpesvirus 4 (BoHV-4) has been isolated from several outbreaks of metritis or abortion, the role of viruses in endometrial pathology and the mechanisms of viral infection of uterine cells are often ignored. The objectives of the present study were to explore the interaction, tropism and outcomes of BoHV-4 challenge of endometrial stromal and epithelial cells. Endometrial stromal and epithelial cells were purified and infected with a recombinant BoHV-4 carrying an enhanced green fluorescent protein (EGFP) expression cassette to monitor the establishment of infection. BoHV-4 efficiently infected both stromal and epithelial cells, causing a strong non-apoptotic cytopathic effect, associated with robust viral replication. The crucial step for the BoHV-4 endometriotropism appeared to be after viral entry as there was enhanced transactivation of the BoHV-4 immediate early 2 gene promoter following transient transfection into the endometrial cells. Infection with BoHV-4 increased cyclooxygenase 2 protein expression and prostaglandin estradiol secretion in endometrial stromal cells, but not epithelial cells. Bovine macrophages are persistently infected with BoHV-4, and co-culture with endometrial stromal cells reactivated BoHV-4 replication in the persistently infected macrophages, suggesting a symbiotic relationship between the cells and virus. In conclusion, the present study provides evidence of cellular and molecular mechanisms, supporting the concept that BoHV-4 is a pathogen associated with uterine disease.

Nitric oxide synthase and cyclooxygenase interactions in cartilage and meniscus: relationships to joint physiology, arthritis, and tissue repair

Rheumatoid arthritis and osteoarthritis are painful and debilitating diseases with complex pathophysiology. There is growing evidence that pro-inflammatory cytokines (e.g., interleukin-1 and tumor necrosis factor alpha) and mediators (e.g., prostaglandins, leukotrienes, and nitric oxide) play critical roles in the development and perpetuation of tissue inflammation and damage in joint tissues such as articular cartilage and meniscus. While earlier studies have generally focused on cells of the synovium (especially macrophages), there is increasing evidence that chondrocytes and meniscal cells actively contribute to inflammatory processes. In particular, it is now apparent that mechanical forces engendered by joint loading are transduced to biological signals at the cellular level and that these signals modulate gene expression and biochemical processes. Here we give an overview of the interplay of cytokines and mechanical stress in the production of cyclooxygenases and prostaglandins; lipoxygenases and leukotrienes; and nitric oxide synthases and nitric oxide in arthritis, with particular focus on the interactions of these pathways in articular cartilage and meniscus.

Preventive and therapeutic anti-inflammatory effects of systemic and topical thalidomide on endotoxin-induced uveitis in rats

The present study examined the outcomes of systemic or topical treatment with thalidomide, a compound that possesses anti-inflammatory, immunomodulatory and anti-angiogenic properties, in rats subjected to endotoxin-induced uveitis (EIU). The effects of thalidomide were evaluated on endotoxin-induced leucocyte and protein infiltration and also on the production of interleukin (IL)-1beta and tumour necrosis factor (TNF)-alpha in rat aqueous humour (AqH). Moreover, the actions of thalidomide were assessed on the cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) protein expression in retinal tissue. EIU was produced by a hindpaw injection of lipopolysaccharide (LPS), in male Wistar rats. Thalidomide (5, 25 and 50 mg/kg) was administered orally 1 h before LPS injection. In another set of experiments, to evaluate the therapeutic efficacy, 5% thalidomide was applied topically to both eyes at 6, 12 and 18 h after LPS administration. The oral pre-treatment with thalidomide decreased, in a dose-dependent manner, the number of inflammatory cells, the protein concentration, and the levels of IL-1beta and TNF-alpha in the AqH. Similar results were found in the AqH of rats that received a topical application of thalidomide. Furthermore, oral (50 mg/kg) and local (5%) thalidomide treatment also reduced expression of the pro-inflammatory proteins COX-2 and iNOS in the posterior segment of the eye. Thalidomide exhibited marked preventive and curative ocular effects in EIU in rats, a property that might be associated with its ability to inhibit the production of inflammatory cytokines and the expression of COX-2 and iNOS. This assembly of data provides additional molecular and functional insights into beneficial effects of thalidomide as an agent for the management of ocular inflammation.

Immolina, a high-molecular-weight polysaccharide fraction of Spirulina, enhances chemokine expression in human monocytic THP-1 cells

INTRODUCTION

Spirulina (Spirulina platensis) is a dietary supplement valued for its immune-enhancing properties. We previously reported that the immunostimulatory effect of spirulina can be traced to a high-molecular- weight polysaccharide fraction. This fraction, labeled Immolina, activates nuclear factor kappa-B in human monocytic THP-1 cells and increases expression of proinflammatory cytokines.

OBJECTIVE

To characterize further the immunostimulatory effects of Immolina on THP-1 cells, we evaluated its effect on genes encoding the chemokines interleukin (IL)-8, MCP-1, MIP-1alpha, MIP-1beta, IP-10, the cytokines tumor necrosis factor (TNF)-alpha, IL-1beta, and the enzyme cyclo-oxygenase-2 (COX-2).

METHODS

THP-1 cells were exposed to concentrations of Immolina ranging from 1 ng/mL to 100 microg/mL and changes in gene expression were assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). For comparison, THP-1 cells were activated with 1 ng/mL of TNF-alpha, 10 ng/mL of IL-1beta, or 10 ng/mL of lipopolysaccharide using the same assay conditions. To assess the response of THP-1 cells to Immolina at the protein level, we probed culture supernatants using a cytokine array immunoblot assay.

RESULTS

RT-PCR analysis revealed that Immolina dose-dependently increased the expression of all 5 chemokines tested as well as the expression of TNF-alpha, IL-1beta, and COX-2. The cytokine array immunoblot assay revealed an increase in the chemokines IL-8 and MIP-1beta. Thymidine uptake experiments verified that Immolina did not affect the viability and growth rate of THP-1 cells.

CONCLUSIONS

The results of the experiments demonstrate that Immolina activates THP-1 cells in a manner that is consistent with the recruitment of diverse populations of leukocytes in response to inflammatory and infectious signals.

Neuroprotective effect of Buddleja officinalis extract on transient middle cerebral artery occlusion in rats

The flower buds of Buddleja officinalis MAXIM (Loganiaceae) are used to treat headache and inflammatory diseases in traditional Korean medicine. In the present study, the neuroprotective effects of the methanolic extract of B. officinalis (BOME) and of its hexane fraction (BOHF) were investigated in a middle cerebral artery occlusion (MCAo, 120 min occlusion, 24 h reperfusion) Sprague-Dawley rat model. BOME or BOHF (100 mg/kg, p.o.) was twice administered 30 min before the onset of MCAo and 2 h after reperfusion. BOME and BOHF treated groups showed infarct volumes reduced by 33.9% and 68.2%, respectively, at 2 h occlusion. In BOHF treated animals, cyclooxygenase-2 and iNOS inductions were inhibited in ischemic hemispheres at both the mRNA and protein levels. Furthermore, in vitro studies showed that BOME and BOHF both inhibited LPS-induced nitric oxide production in BV-2 mouse microglial cells. These results suggest that the anti-inflammatory and the microglial activation inhibitory effects of B. officinalis extract may contribute to its neuroprotective effects in brain ischemia.

The molecular biology of chronic wounds and delayed healing in diabetes

Wound healing is a complicated and integrated process. Although there is some tolerance in terms of redundancy and interrelated control mechanisms, pushing beyond such limits may contribute to delayed wound healing, and in extreme cases lead to chronic wounds/ulcers and thus potentially to lower extremity amputation. Diabetes is associated with such disruption in wound healing. Research in humans and in animal models has identified a large number of changes associated with diabetes at the molecular level in delayed wound healing and to a lesser extent in chronic diabetic ulcers. Better overall understanding of these changes and how they are interrelated would allow for specifically targeted treatment, thus ensuring improved quality of life for patients and providing savings to the high costs that are associated with all aspects of chronic diabetic ulcers. This review examines the work done at the molecular level on chronic diabetic ulcers, as well as considering changes seen in diabetes in general, both in humans and animal models, that may in turn contribute to ulcer formation.

In vitro effects on polydextrose by colonic bacteria and caco-2 cell cyclooxygenase gene expression

A 4-stage colon simulator and a cell culture-based human intestinal epithelial function model were combined to study the effects of a soluble fiber, polydextrose (PDX), on intestinal microbes and mucosal functions relevant to the risk of colon cancer. We observed sustained degradation of PDX throughout the different stages of the model. The fermentation was characterized by gradual degradation of PDX, production of short-chain fatty acids, and no increasing in putrefactive markers. We observed less marked effects in the microbial densities. When we applied colon fermentation metabolites obtained from the simulators with PDX to Caco-2 colon cancer cell line, a significant dose-dependent decreasing effect on cyclooxygenase-2 (COX-2) and an increasing effect on COX-3 expression levels were observed. PDX concentration appeared not to have effect on the expression levels of COX-1. Overexpression of COX-2 and decreased expression of COX-1 have been suggested to be characteristics of colon cancer. The exact physiological role of COX-3, an intron-retaining splice variant of COX-1, is not known, but it is suspected to play a role in transcriptional regulation of COX-1 and COX-2. In vitro modulation of COX expression by colon microbial fermentation products of polydextrose offers an interesting starting point for further studies on possible risk-decreasing effect of PDX on the development of colon cancer.

Inducible nitric oxide synthase binds, S-nitrosylates, and activates cyclooxygenase-2

Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are two major inflammatory mediators. Here we show that iNOS specifically binds to COX-2 and S-nitrosylates it, enhancing COX-2 catalytic activity. Selectively disrupting iNOS-COX-2 binding prevented NO-mediated activation of COX-2. This synergistic molecular interaction between two inflammatory systems may inform the development of anti-inflammatory drugs.

Reduced peripheral PGE2 biosynthesis in Plasmodium falciparum malaria occurs through hemozoin-induced suppression of blood mononuclear cell cyclooxygenase-2 gene expression via an interleukin-10-independent mechanism

Molecular immunologic determinants of disease severity during Plasmodium falciparum malaria are largely undetermined. Our recent investigations showed that peripheral blood mononuclear cell (PBMC) cyclooxygenase-2 (COX-2) gene expression and plasma prostaglandin E(2) (PGE(2)) production are suppressed in children with falciparum malaria relative to healthy, malaria-exposed children with partial immunity. Furthermore, decreased COX-2/PGE(2) levels were significantly associated with increased plasma interleukin-10 (IL-10), an anti-inflammatory cytokine that inhibits the expression of COX-2 gene products. To determine the mechanism(s) responsible for COX-2-derived PGE(2) suppression, PBMCs were cultured from children with falciparum malaria. PGE(2) production was suppressed under baseline and COX-2-promoting conditions (stimulation with lipopolysaccharide [LPS] and interferon [IFN]-gamma) over prolonged periods, suggesting that an in vivo-derived product(s) was responsible for reduced PGE(2) biosynthesis. Ingestion of hemozoin (malarial pigment) by PBMC was investigated as a source of COX-2/PGE(2) suppression in PBMCs from healthy, malaria-naive adults. In addition, synthetically prepared hemozoin, beta-hematin, was used to investigate the effects of the core iron component of hemozoin, ferriprotoporphyrin-IX (FPIX). Physiologic concentrations of hemozoin or b-hematin suppressed LPS- and IFN-gamma-induced COX-2 mRNA in a time- and dose-dependent manner, resulting in decreased COX-2 protein and PGE(2) production. Suppression of COX-2/PGE(2) by hemozoin was not due to decreased cell viability as evidenced by examination of mitochondrial bioactivity. These data illustrate that ingestion of FPIX by blood mononuclear cells is responsible for suppression of COX-2/PGE(2). Although hemozoin induced overproduction of IL-10, neutralizing IL-10 antibodies failed to restore PGE(2) production. Thus, acquisition of hemozoin by blood mononuclear cells is responsible for suppression of PGE(2) in malaria through inhibition of de novo COX-2 transcripts via molecular mechanisms independent of increased IL-10 production.

Curcumin suppresses lipopolysaccharide-induced cyclooxygenase-2 expression by inhibiting activator protein 1 and nuclear factor kappab bindings in BV2 microglial cells

Inflammation is a significant component of chronic neurodegenerative diseases. Cyclooxygenase-2 (COX-2) is expressed in activated microglial cells and appears to be an important source of prostaglandins during inflammatory conditions. To investigate the effect of curcumin on COX-2 gene expression in microglial cells, we treated lipopolysaccharide (LPS)-challenged BV2 microglial cells with various concentrations of curcumin. Curcumin significantly inhibited LPS-mediated induction of COX-2 expression in both mRNA and protein levels in a concentration-dependent manner. COX-2 enzyme activity was also inhibited in accordance with mRNA and protein levels. Furthermore, curcumin markedly inhibited LPS-induced nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1) DNA bindings. These data suggest that curcumin suppresses LPS-induced COX-2 gene expression by inhibiting NF-kappaB and AP-1 DNA bindings in BV2 microglial cells.

The role of antioxidants in models of inflammation: Emphasis on l-arginine and arachidonic acid metabolism

Inflammatory processes are made up of a multitude of complex cascades. Under physiological conditions these processes aid in tissue repair. However, under pathophysiological environments, such as wound healing and hypoxia-ischaemia (HI), inflammatory mediators become imbalanced, resulting in tissue destruction. This review addresses the changes in reactive oxygen species (ROS), L-arginine and arachidonic acid metabolism in wound healing and HI and subsequent treatments with promising anti-oxidants. Even though these models may appear divergent, anti-oxidant treatments are nevertheless still having favourable effects. On the basis of recent findings, it is apparent that protection with anti-oxidants is not solely attributed to scavenging of ROS. In addition, the actions of anti-oxidants must be considered in light of the inflammatory process being assessed. To this end, there does not appear to be any universally applicable single mechanism to explain the actions of anti-oxidants.

Cyclooxygenase-1 and -2 are required for production of infectious pseudorabies virus

We have recently shown that cyclooxygenase-2 (COX-2) transcription is markedly induced after herpes simplex virus type 1 and pseudorabies virus (PRV) infections of rat embryonic fibroblast (REF) cells (N. Ray and L. W. Enquist, J. Virol. 78:3489-3501, 2004). For this study, we investigated the role of cyclooxygenase induction in the replication and growth of PRV. We demonstrate here a concordant increase in COX-2 mRNA and protein levels after the infection of REF cells. Inhibitors blocking the activity of cyclooxygenases caused a dramatic reduction in PRV growth. Viral growth could be restored if prostaglandin E(2), the final product of COX-2 activity, was added simultaneously with the COX inhibitors. Immediate-early protein IE180, major capsid protein VP5, and glycoprotein expression were slightly reduced in the presence of COX-2 inhibitors, but expression of the early protein EP0 was not affected by COX inhibition. Viral DNA replication was marginally reduced in the presence of a COX-1/2 inhibitor, but there was no defect in viral DNA cleavage. Electron microscopy analysis revealed an increased number of unusual empty capsid structures in the nuclei of cells infected with PRV in the presence of a COX-1/2 inhibitor. These capsid structures shared some characteristics with procapsids but had a novel appearance by negative staining. Our data establish a role for COX-1 and COX-2 in facilitating the efficient growth and replication of PRV in primary cells.

Effects of epicatechin gallate on wound healing and scar formation in a full thickness incisional wound healing model in rats

Catechins are naturally occurring polyphenolic compounds with putative anti-inflammatory, antioxidant and free radical scavenging effects in vitro. However, their potential effects in vivo have not been established. Therefore we have investigated the effects of the catechin epicatechin gallate (ECG), on scar formation in a full thickness incisional model of wound healing in rats. ECG showed a significant improvement in the quality of scar formation both in terms of maturity and orientation of the collagen fibers. An increase in inducible nitric oxide synthase and cyclooxygenase-2 and a decrease in arginase-I activity and protein levels were observed at earlier time points. In addition, an increase in the number of new blood vessels was observed in the ECG-treated group. This correlated with the protein levels of vascular endothelial growth factor, the most potent angiogenic protein known. This study has therefore demonstrated, for the first time, that catechins, namely ECG, can significantly improve the quality of wound healing and scar formation. These effects may in part be due to an acceleration of the angiogenic response and an up-regulation of the enzymes nitric oxide synthase and cyclooxygenase.

ClC-2 chloride secretion mediates prostaglandin-induced recovery of barrier function in ischemia-injured porcine ileum

BACKGROUND & AIMS

Ischemia results in the breakdown of the intestinal barrier, predisposing patients to sepsis and multiple organ failure. Prostaglandins play a critical role in mediating recovery of barrier function in ischemia-injured intestine through a mechanism involving stimulation of Cl - secretion. In the present study, we investigated the contributory role of individual Cl - channels in the recovery of barrier function in ischemia-injured porcine ileum.

METHODS

Ischemia-injured porcine ileal mucosa was mounted in Ussing chambers. Short-circuit current (Isc) and transepithelial resistance (TER) were measured in response to prostaglandin E 2 (PGE 2 ) and pharmacologic inhibitors of epithelial Cl - channels. Immunoassays were used to assess the expression and localization of ion channels.

RESULTS

Application of PGE 2 to ischemia-injured ileal mucosa stimulated increases in Isc, an indicator of Cl - secretion, that was followed by marked increases in TER, an indicator of barrier function recovery. In vitro studies revealed that although PGE 2 induced Cl - secretion via at least 3 distinct secretory pathways, recovery of barrier function was initiated by Cl - secretion via ClC-2 Cl - channels co-expressed with occludin and localized to tight junctions within restituting epithelium. Intravenous administration of furosemide to pigs subjected to 1 hour of ileal ischemia impaired recovery of barrier function, as evidenced by decreased TER and increased mucosal-to-serosal 3 H-mannitol flux after a 2-hour reperfusion/recovery period, confirming an important role for Cl - secretory pathways in vivo.

CONCLUSIONS

ClC-2-mediated intestinal Cl - secretion restores TER in ischemia-injured intestine. These data may provide the basis for targeted pharmacologic therapy for diseases associated with impaired barrier function.

Antiallergic activity of ginsenoside Rh2

The antiallergic activities of ginsenosides, which were isolated from acid-treated ginseng (Panax ginseng, Araliaceae), and their metabolites by human intestinal bacteria were measured. Ginsenoside Rh2, which is a main metabolite, had the most potent inhibitory activity on beta-hexosaminidase release from RBL-2H3 cells and in the passive cutaneous anaphylaxis reaction. The inhibitory activity of ginsenoside Rh2 was more potent than that of disodium cromoglycate, a commercial antiallergic drug. This compound showed membrane stabilizing action upon differential scanning calorimetry and inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharide-stimulated RAW cells. However, this ginsenoside Rh2 did not inhibit the activation of hyaluronidase and did not scavenge active oxygen. These results suggest that ginsenoside Rh2 can exhibit antiallergic activity originating from cell membrane-stabilizing activity and antiinflammatory activity by the inhibition of NO and PGE2 production.

Chronic prostatitis/chronic pelvic pain syndrome in elderly men: toward better understanding and treatment

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is the most common of the prostatitis syndromes. It is characterised by pelvic pain, with or without voiding symptoms. CP/CPPS accounts for 2 million office visits in the US alone. Recent epidemiological studies have shown that CP/CPPS can affect men at any age, including those in their 80s. The aetiology is unknown but proposals include infectious, autoimmune, neurologic and psychiatric causes. Men with CP/CPPS are much more likely to have had a past medical history of cardiovascular, neurologic, psychiatric or infectious disease (particularly sinusitis) as compared with asymptomatic individuals. Although leucocytes are commonly found in the prostatic fluid of these men, they do not correlate with the symptoms. The clinical evaluation now includes a validated, self administered symptom score, the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), which was designed as an outcome measure for treatment trials. This can aid in diagnosis and follow-up of patients' response to therapy. Treatment for CP/CPPS is empiric and limited by a lack of randomised, placebo-controlled clinical trials. Antimicrobials are commonly used to treat the symptoms of CP/CPPS. However, the finding that asymptomatic men have equal or greater numbers of bacteria which localise to the prostatic fluid, compared with men with CP/CPPS, has raised doubts about the contribution of infection to the symptoms. Other commonly used drugs include alpha-adrenoceptor antagonists, anti-inflammatory drugs, tricyclic antidepressants and anticholinergic agents. The adverse effects of these medications are a concern in older men with CP/CPPS. Other therapies available include minimally invasive procedures such as microwave thermotherapy and transurethral needle ablation, and now neuromodulation devices.Although much progress has been made, particularly in the last 7 years, considerable work still remains to be done to determine the aetiology and pathogenesis of CP/CPPS, and to develop mechanism based therapy that is shown to be effective in controlled trials.

Distribution of constitutive (COX-1) and inducible (COX-2) cyclooxygenase in postviral human liver cirrhosis: a possible role for COX-2 in the pathogenesis of liver cirrhosis

AIMS

Prostaglandins produced by the action of cyclooxygenases (COX) are important mediators of systemic vasodilatation and inflammation in liver cirrhosis. The aim of this study was to investigate the distribution of COX-1 and COX-2 in postviral cirrhosis.

METHODS

The immunohistochemical expression of the constitutive (COX-1) and the inducible (COX-2) isoenzymes was investigated in 15 patients with cirrhosis after hepatitis B and C infection; three normal control livers were also analysed.

RESULTS

COX-2 was absent from normal liver but was highly expressed in cirrhosis, mainly in the inflammatory, sinusoidal, vascular endothelial, and biliary epithelial cells. Low amounts of COX-1 were expressed in both normal and cirrhotic livers, exclusively in sinusoidal and vascular endothelial cells, with no differences seen between normal and cirrhotic livers.

CONCLUSIONS

COX-2 is overexpressed in liver cirrhosis, and possibly contributes to prostaglandin overproduction, which may be a major component of the inflammation and hyperdynamic circulation associated with cirrhosis. Because COX-2 is thought to contribute to tumour development, high COX-2 production could be a contributor to hepatocellular carcinoma development in cirrhosis. The finding of COX-2 and not COX-1 upregulation in cirrhosis could provide a possible new role for selective COX-2 inhibitors in reducing inflammation and minimising the occurrence of hepatocellular carcinoma in patients with cirrhosis.

Inflammatory effects of snake venom myotoxic phospholipases A2

Snake venom phospholipases A2 (PLA2) show a remarkable functional diversity. Among their toxic activities, some display the ability to cause rapid necrosis of skeletal muscle fibers, thus being myotoxic PLA2s. Besides myotoxicity, these enzymes evoke conspicuous inflammatory and nociceptive events in experimental models. Local inflammation and pain are important characteristics of snakebite envenomations inflicted by viperid and crotalid species, whose venoms are rich sources of myotoxic PLA2s. Since the discovery that mammalian PLA2 is a key enzyme in the release of arachidonic acid, the substrate for the synthesis of several lipid inflammatory mediators, much interest has been focused on this enzyme in the context of inflammation. The mechanisms involved in the proinflammatory action of secretory PLA2s are being actively investigated, and part of the knowledge on secretory PLA2 effects has been gained by using snake venom PLA2s as tools, due to their high structural homology with human secretory PLA2s. The inflammatory events evoked by PLA2s are primarily associated with enzymatic activity and to the release of arachidonic acid metabolites. However, catalytically inactive Lys49 PLA2s trigger inflammatory and nociceptive responses comparable to those of their catalytically active counterparts, thereby evidencing that these proteins promote inflammation and pain by mechanisms not related to phospholipid hydrolysis nor to mobilization of arachidonic acid. These studies have provided a boost to the research in this field and various approaches have been used to identify the amino acid residues and the specific sites of interaction of myotoxic PLA2s with cell membranes potentially involved in the PLA2-induced inflammatory and nociceptive effects. This work reviews the proinflammatory and nociceptive effects evoked by myotoxic PLA2s and their mechanisms of action.

Inhibitory Effect of Chunghyuldan in Prostaglandin E2 and Nitric Oxide Biosynthesis of Lipopolysaccharide-Induced RAW 264.7 Cells

Chunghyuldan (Daio-Orengedokuto in Japanese) (CHD) has been used as an antihyperlipidemic and antiischemic agent in Korea. To evaluate in vitro the efficacy of Chunghyuldans (CHDs) metabolized with and without human intestinal microflora against brain ischemia, we investigated its anti-inflammatory effect on LPS-induced RAW264.7 cells. Both metabolized CHD (MCHD) and CHD showed antioxidant activities in vitro, and inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) productions in lipopolysaccharide (LPS)-induced RAW264.7 cells. These also inhibited enzyme activities and protein expressions of inducible NO synthase and cyclooxygenase-2 in LPS-induced RAW264.7 cells. MCHD-inhibitory activity against NO and PGE2 productions in LPS-induced RAW264.7 cells was more potent than those of CHD. These results suggest that CHD may show potent anti-inflammatory activity in vivo and can improve brain ischemia.

Generation and characterisation of an equine macrophage cell line (e-CAS cells) derived from equine bone marrow cells

Macrophages play a pivotal role in the pathophysiology of many diseases by mediating the host immune response to infections and intoxications. The species-specific activation of macrophages and the differential response in cytokine production impedes the extrapolation of results between species. Therefore, the aim of this study was to isolate and immortalise macrophages from equine bone marrow (BM) cells in order to study equine-specific signalling pathways. The isolated BM-derived macrophages (referred to as e-CAS cells) showed proliferation kinetics similar to that of standardised cell lines and were maintained in culture for >76 passages. To characterise the cells, a number of typical parameters of macrophages were tested. Morphological evaluation (May-Grünwald Giemsa staining) and non-specific esterase activity indicated the e-CAS cells to be macrophages. The presence of CD14 and their ability to phagocytose Escherichia coli bioparticles further confirmed their identity, as did their ability to produce cytokines, reactive oxygen and nitrogen intermediates in response to LPS. These data show that the established cell line (e-CAS) shows the characteristics of equine macrophages and may, therefore, prove to be a unique in vitro model for studying the cellular biology of equine inflammation.

Induction of redox changes, inducible nitric oxide synthase and cyclooxygenase-2 by chronic cadmium exposure in mouse peritoneal macrophages

Redox changes and the secretion of inflammatory mediators were investigated in resident peritoneal macrophages of mice chronically exposed to cadmium (Cd, 15 ppm for 2 months) through drinking water. Our results showed that in vivo Cd exposure altered the redox balance in mouse peritoneal macrophages, leading to excessive production of reactive oxygen species (ROS) that overwhelmed the antioxidant defenses. It also led to increased lipid peroxidation and arachidonic acid (AA) release, higher nitric oxide and prostaglandin E(2) (PGE(2)) production, and induction of inducible nitric oxide synthase and cyclooxygenase-2 compared with control macrophages. Oxidative stress and inflammation could be important processes operating in the modulation of mouse macrophage physiology induced by chronic Cd exposure.

Expression of nitric oxide synthase isoforms in human liver cirrhosis

Several mediators of systemic vasodilatation in liver cirrhosis have been reported. Among these is nitric oxide (NO), which has been proposed as one of the main mediators. In this study, sera and liver biopsies were analysed from 15 patients with clinically and pathologically diagnosed liver cirrhosis. In addition, sera from seven and liver biopsies from three healthy controls were used. Serum levels of nitrite (the end product of NO) were measured using the Griess reaction and the expression of the inducible nitric oxide synthase (iNOS) and constitutive nitric oxide synthase (ecNOS) proteins was investigated using immunohistochemistry. This study shows that serum nitrite levels (94 +/- 9.8 micro mol/l) in cirrhotic patients were significantly (p < 0.05) increased in comparison with the controls (36.6 +/- 11.03 micro mol/l). iNOS was completely absent from the control group but was highly expressed in the livers from the cirrhotic group. iNOS was seen mainly in the inflammatory cells infiltrating the portal tracts, blood monocyte-like cells, hepatocytes, sinusoidal cells, and endothelial cells. However, expression of ecNOS was only seen in the vascular endothelial cells of both the control and the cirrhotic groups, but was much higher in the latter. It is therefore clear that NO is augmented in cirrhotic patients and it is mainly produced by induction of iNOS. Moreover, NO up-regulation is dependent on the inflammatory stage of liver cirrhosis. ecNOS production could be a normal chronic adaptation mechanism of the endothelium to the chronically increased splanchnic blood flow secondary to portal hypertension. In the near future, the appropriate inhibition of NO activity by using NOS-active agents may provide a novel strategy for the treatment of patients with liver cirrhosis.