6-keto PGF1 Research Articles

Electroacupuncture Treatment for Primary Dysmenorrhea: A Review of Randomized Controlled Trials

To evaluate the effectiveness of electroacupuncture treatment for primary dysmenorrhea (PD), a literature review of a randomized controlled trials (RCTs) was performed where electroacupuncture was used as a treatment intervention in patients diagnosed with PD. Relevant clinical studies (N = 226) were retrieved from multiple databases according to the study inclusion/exclusion criteria, and interventions and outcomes were analyzed. As a result of the review, there were 6 RCTs which met the criteria. In all 4 studies that measured pain indicators (visual analog scales), electroacupuncture showed significantly positive changes. In addition, positive changes were observed in most indicators (MMDQ, PGF2a, PGE2, 6-keto PGF1, TXB2, clinical efficacy score, uterine arterial blood flow parameters, and blood viscosity). 2 studies showed that electroacupuncture had a stronger therapeutic effect than NSAIDs. No major side effects were reported. Electroacupuncture may be an effective and safe treatment for PD however, further RCTs are required.

Carnosol and Carnosic Acids fromSalvia officinalisInhibit Microsomal Prostaglandin E2Synthase-1

Prostaglandin E(2) (PGE(2)), the most relevant eicosanoid promoting inflammation and tumorigenesis, is formed by cyclooxygenases (COXs) and PGE(2) synthases from free arachidonic acid. Preparations of the leaves of Salvia officinalis are commonly used in folk medicine as an effective antiseptic and anti-inflammatory remedy and possess anticancer activity. Here, we demonstrate that a standard ethyl acetate extract of S. officinalis efficiently suppresses the formation of PGE(2) in a cell-free assay by direct interference with microsomal PGE(2) synthase (mPGES)-1. Bioactivity-guided fractionation of the extract yielded closely related fractions that potently suppressed mPGES-1 with IC(50) values between 1.9 and 3.5 μg/ml. Component analysis of these fractions revealed the diterpenes carnosol and carnosic acid as potential bioactive principles inhibiting mPGES-1 activity with IC(50) values of 5.0 μM. Using a human whole-blood assay as a robust cell-based model, carnosic acid, but not carnosol, blocked PGE(2) generation upon stimulation with lipopolysaccharide (IC(50) = 9.3 μM). Carnosic acid neither inhibited the concomitant biosynthesis of other prostanoids [6-keto PGF(1α), 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid, and thromboxane B(2)] in human whole blood nor affected the activities of COX-1/2 in a cell-free assay. Together, S. officinalis extracts and its ingredients carnosol and carnosic acid inhibit PGE(2) formation by selectively targeting mPGES-1. We conclude that the inhibitory effect of carnosic acid on PGE(2) formation, observed in the physiologically relevant whole-blood model, may critically contribute to the anti-inflammatory and anticarcinogenic properties of S. officinalis.

Roflumilast inhibits the release of chemokines and TNF‐α from human lung macrophages stimulated with lipopolysaccharide

Lung macrophages are critically involved in respiratory diseases. This study assessed the effects of the PDE4 inhibitor roflumilast and its active metabolite, roflumilast N-oxide on the release of a range of chemokines (CCL2, 3, 4, CXCL1, 8, 10) and of TNF-α, from human lung macrophages, stimulated with bacterial lipopolysaccharide LPS. Lung macrophages isolated from resected human lungs were incubated with roflumilast, roflumilast N-oxide, PGE(2), the COX inhibitor indomethacin, the COX-2 inhibitor NS-398 or vehicle and stimulated with LPS (24 h). Chemokines, TNF-α, PGE(2) and 6-keto PGF(1α) were measured in culture supernatants by immunoassay. COX-2 mRNA expression was assessed with RT-qPCR. PDE activities were determined in macrophage homogenates. Expression of PDE4 in lung macrophages was increased after incubation with LPS. Roflumilast and roflumilast N-oxide concentration-dependently reduced the LPS-stimulated release of CCL2, CCL3, CCL4, CXCL10 and TNF-α from human lung macrophages, whereas that of CXCL1 or CXCL8 was not altered. This reduction by the PDE4 inhibitors was further accentuated by exogenous PGE(2) (10 nM) but abolished in the presence of indomethacin or NS-398. Conversely, addition of PGE(2) (10 nM), in the presence of indomethacin restored inhibition by roflumilast. LPS also increased PGE(2) and 6-keto PGF(1α) release from lung macrophages which was associated with an up-regulation of COX-2 mRNA. Roflumilast and roflumilast N-oxide reduced LPS-induced release of CCL2, 3, 4, CXCL10 and TNF-α in human lung macrophages.

Quantification of intracellular and extracellular prostanoids stimulated by A23187 by liquid chromatography/electrospray ionization tandem mass spectrometry

Prostanoids are bioactive substances that contribute to various biological and pathological processes. To evaluate both extracellular and intracellular levels of prostanoids at the same time, we developed methods for quantification of extracellular and intracellular levels of prostanoids, including prostaglandin E 2 (PGE 2), PGD 2, PGF 2α, 6-keto PGF 1α, and TXB 2, in cultured cells using liquid chromatography/tandem mass spectrometry (LC/MS/MS), and we validated the LC/MS/MS methods. A solid-phase extraction cartridge was used for extraction of prostanoids. The prostanoids were separated by a C 18 column with an isocratic flow of acetonitrile/water/acetic acid (40:60:0.1, v/v/v). Calibration curves of extracellular measurement for the prostanoids were linear in the range from 0.1 to 100 ng/mL ( r 2 > 0.999), and those of intracellular measurement were linear in the range from 0.05 to 50 ng ( r 2 > 0.999). Validation assessment showed that both methods of extracellular and intracellular measurements were highly reliable with good accuracy and precision. We also applied the methods to human airway epithelial Calu-3 cells and human lung adenocarcinoma epithelial A549 cells.

Comparison of UHPLC and HPLC Methods for The Assay of Prostanoids: “Are The Methods Equivalent in Terms of Accuracy and Precision?”

As new methods are developed to increase efficiency and higher analytical performance, it is necessary to evaluate their quality in comparison to standard methods. To understand how the analytical performance changes between methods, it is common to compare the validation parameters; sensitivity, linearity, accuracy and precision. Here, we compare an UHPLC-UV method to the HPLC-UV method (reference method) for the simultaneous determination of seven prostanoids. Though the basic chromatography theory is the same for HPLC and UHPLC, the instrumentation has been modified to accommodate higher pressures, lower flow rates and smaller sample size. The differences in analytical instrumentation and procedures can give rise to method inequivalencies. Our approach evaluates the UHPLC and HPLC methods and poses the question: are the methods equivalent? To answer this question a statistical comparison of the analytical performance and method parameters is necessary. Statistical comparisons were performed using the t-test, F-test, regression analyses (ordinary linear regression and Deming regression) and Bland-Altman analyses. Statistical comparison of the results, suggested that the precision (amount of variability) is different (p < 0.05) for the HPLC and UHPLC methods. Whereas, the accuracy (method bias and the means) is similar (p > 0.05) for 8-isoprostane, 11-dehydro TXB₂, PGE₂ PGF(2α), PGD₂ and 15-deoxy Δ¹²,¹⁴ PGJ₂. Ordinary linear regression shows that the methods are well correlated for all compounds. The Deming regression, which assumes error in both the methods, suggests the existence of a proportional and constant bias for 11-dehydro TXB₂ and only proportional bias for 8-isoprostane, PGF(2α), PGD₂ and 15-deoxy Δ(12,14) PGJ₂ between the two methods. According to Deming regression, the two methods are statistically similar for 6-keto PGF(1α) and PGE₂. The Bland-Altman analyses indicate the two methods are commutable.

Effects of Acupuncture at Sanyinjiao (SP6) on Prostaglandin Levels in Primary Dysmenorrhea Patients

To explore the physiologic mechanism of immediate analgesic effect of acupuncture in primary dysmenorrhea patients. Forty primary dysmenorrhea patients were randomized into the Sanyinjiao (SP6) acupuncture group, Xuanzhong (GB39) control group, nonacupoint control group, or no acupuncture group. Patients in the 3 acupuncture groups were treated with electroacupuncture at assigned points lasting 30 minutes, whereas patients in no acupuncture group did not receive any acupuncture intervention. Before and after acupuncture, visual analogue scale (VAS) scores were recorded and blood samples were taken for the measurement of the plasma levels of 4 principal prostaglandins (PGE(2), PGF(2a), TXB(2), and 6-keto PGF(1a)). The VAS scores for pain intensity significant decreased in patients who received acupuncture compared with those had no acupuncture intervention. However, there were no significant differences among patients in the 3 acupuncture groups after acupuncture. In addition, no statistically significant differences were observed in the plasma PGE(2), PGF(2a), TXB(2), or 6-keto PGF(1a) levels and the ratios of PGF(2a)/PGE(2), and TXB(2)/6-keto PGF(1a) after acupuncture at SP6. The immediate analgesic effect of SP6 might not be mediated by changes in the prostaglandin levels.

A targeted lipidomics approach to the study of eicosanoid release in synovial joints

IntroductionArticular tissues are capable of producing a range of eicosanoid mediators, each of which has individual biological effects and may be affected by anti-inflammatory treatment. We set out to develop and evaluate a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) approach for the simultaneous analysis of multiple eicosanoid lipid mediators in equine synovial fluid (SF), and to illustrate its use for investigation of the in vivo effects of non-steroidal anti-inflammatory drug (NSAID) treatment.MethodsSynovial fluid samples were obtained from normal joints of 6 adult horses at baseline (0 hr) and at 8, 24 and 168 hours after experimental induction of transient acute synovitis, with horses treated once daily with oral NSAID (meloxicam, 0.6 mg/kg) or placebo. Following solid-phase extraction, SF lipid mediator quantitation was based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis, and results were compared between disease states using linear discriminant analysis (LDA) and analysis of variance (ANOVA) with multiple comparisons corrections.ResultsOf a total of 23 mediators targeted, 14 could be reliably identified and quantified in SF samples based on detection of characteristic fragment ions at retention times similar to those of commercial standards. LDA analysis of baseline, 8, 24 and 168 hour synovial fluid samples revealed a separation of these groups into discrete clusters, reflecting dynamic changes in eicosanoid release over the course of synovitis. Prostaglandin (PG) E2 was significantly lower in NSAID vs. placebo treated samples at all time points; PGE1, 11-hydroxyeicosatetraenoic acid (11-HETE) and 13,14-dihydro-15keto PGF2α were reduced at 8 and 24 hours by NSAID treatment; while 15-HETE, 6-keto PGF1α, PGF2α, 13,14-dihydro-15keto PGE2 and thromboxane B2 (TXB2) were reduced at the 8 hour time point only. An interesting pattern was seen for Leukotriene B4 (LTB4), NSAID treatment causing an initial increase at 8 hours, but a significant reduction by 168 hours.ConclusionsThe described method allows a comprehensive analysis of synovial fluid eicosanoid profiles. Eicosanoid release in inflamed joints as well as differences between NSAID treated and placebo treated individuals are not limited to PGE2 or to the early inflammatory phase.

Lipopolysaccharide (LPS) induction of nitric oxide synthase-2 and cyclooxygenase-2 is impaired in fructose overloaded rats

Aims Fructose (F) overload in rats induces metabolic dysfunctions that resemble the human metabolic syndrome. In this paper, we aimed to investigate the response of F overload rats to lipopolysaccharide (LPS) challenge in terms of nitric oxide (NO) production and prostanoids (PR) release. Main methods NO blood steady-state concentration was monitored through the detection of nitrosyl–hemoglobin complexes (NO–Hb) by electronic spin resonance. Production of 6-keto PGF 1α, PGE 2, PGF 2α and TXB 2 was measured in aorta and mesenteric beds by HPLC. Western blot analysis was used to examine the changes in the expression levels of NOS-2 and COX-2 in aorta. Key findings Our results showed that increases in NO circulating steady-state concentration and PR production by aorta and mesenteric beds 6 h after LPS administration were significantly attenuated in F overload rats with respect to control animals. Oxidative stress parameters were equally affected in the presence or absence of the F treatment. Aorta protein levels of NOS-2 and COX-2, two enzymes inducible by LPS, were significantly lower in F overload rats with respect to control rats at the end of the treatment (−39% and −61% for NOS-2 and COX-2 respectively). Significance These results suggest that the metabolic alterations established by 15 weeks of F overload should affect the response to LPS challenge due to an attenuation in the induction of NOS-2 and COX-2. This effect would be one of the components contributing to abnormalities in the course of the inflammatory response in other conditions associated to insulin resistance, such as diabetes.

Inhibition of microsomal prostaglandin E2 synthase‐1 as a molecular basis for the anti‐inflammatory actions of boswellic acids from frankincense

Frankincense, the gum resin derived from Boswellia species, showed anti-inflammatory efficacy in animal models and in pilot clinical studies. Boswellic acids (BAs) are assumed to be responsible for these effects but their anti-inflammatory efficacy in vivo and their molecular modes of action are incompletely understood. A protein fishing approach using immobilized BA and surface plasmon resonance (SPR) spectroscopy were used to reveal microsomal prostaglandin E(2) synthase-1 (mPGES1) as a BA-interacting protein. Cell-free and cell-based assays were applied to confirm the functional interference of BAs with mPGES1. Carrageenan-induced mouse paw oedema and rat pleurisy models were utilized to demonstrate the efficacy of defined BAs in vivo. Human mPGES1 from A549 cells or in vitro-translated human enzyme selectively bound to BA affinity matrices and SPR spectroscopy confirmed these interactions. BAs reversibly suppressed the transformation of prostaglandin (PG)H(2) to PGE(2) mediated by mPGES1 (IC(50) = 3-10 µM). Also, in intact A549 cells, BAs selectively inhibited PGE(2) generation and, in human whole blood, β-BA reduced lipopolysaccharide-induced PGE(2) biosynthesis without affecting formation of the COX-derived metabolites 6-keto PGF(1α) and thromboxane B(2) . Intraperitoneal or oral administration of β-BA (1 mg·kg(-1) ) suppressed rat pleurisy, accompanied by impaired levels of PGE(2) and β-BA (1 mg·kg(-1) , given i.p.) also reduced mouse paw oedema, both induced by carrageenan. Suppression of PGE(2) formation by BAs via interference with mPGES1 contribute to the anti-inflammatory effectiveness of BAs and of frankincense, and may constitute a biochemical basis for their anti-inflammatory properties.

Arzanol, a prenylated heterodimeric phloroglucinyl pyrone, inhibits eicosanoid biosynthesis and exhibits anti-inflammatory efficacy in vivo

Based on its capacity to inhibit in vitro HIV-1 replication in T cells and the release of pro-inflammatory cytokines in monocytes, the prenylated heterodimeric phloroglucinyl α-pyrone arzanol was identified as the major anti-inflammatory and anti-viral constituent from Helichrysum italicum. We have now investigated the activity of arzanol on the biosynthesis of pro-inflammatory eicosanoids, evaluating its anti-inflammatory efficacy in vitro and in vivo. Arzanol inhibited 5-lipoxygenase (EC 7.13.11.34) activity and related leukotriene formation in neutrophils, as well as the activity of cyclooxygenase (COX)-1 (EC 1.14.99.1) and the formation of COX-2-derived prostaglandin (PG)E 2 in vitro (IC 50 = 2.3–9 μM). Detailed studies revealed that arzanol primarily inhibits microsomal PGE 2 synthase (mPGES)-1 (EC 5.3.99.3, IC 50 = 0.4 μM) rather than COX-2. In fact, arzanol could block COX-2/mPGES-1-mediated PGE 2 biosynthesis in lipopolysaccharide-stimulated human monocytes and human whole blood, but not the concomitant COX-2-derived biosynthesis of thromboxane B 2 or of 6-keto PGF 1α, and the expression of COX-2 or mPGES-1 protein was not affected. Arzanol potently suppressed the inflammatory response of the carrageenan-induced pleurisy in rats (3.6 mg/kg, i.p.), with significantly reduced levels of PGE 2 in the pleural exudates. Taken together, our data show that arzanol potently inhibits the biosynthesis of pro-inflammatory lipid mediators like PGE 2 in vitro and in vivo, providing a mechanistic rationale for the anti-inflammatory activity of H. italicum, and a rationale for further pre-clinical evaluation of this novel anti-inflammatory lead.

PP29 ANTILACTOFERRIN ANTIBODIES IN PEDIATRIC PATIENTS: PRIMARY SCLEROSING CHOLANGITIS OR ULCERATIVE COLITIS?

PP30 – Table 1 Glucose Insulin HOMA Cholesterol Triglyceride TNF-α 6-keto PG (mg/dl) (μUI/ml) (mg/dl) (mg/dl) (pg/ml) (pg/ml) Group A (76 pts) 89.3±6.6 14.6±7.7 3.2±1.7 161±29 105.4±60 10.1±5.4 185.1±24.1 (44 pts) Group B (80 pts) 88.0±8.5 11.0±5.8 2.4±1.3 162±32 85.4±50 14±7.5 492.6±91.8 (26 pts) p NS 0.001 0.002 NS 0.025 NS 0.002 and cirrhosis) usually occur in middle and late age, atherosclerotic process in the vascular wall and liver damage might begin very early in obese children. Aim of the study: was to investigate, in children attending our outpatient clinic for obesity, 1) any early vascular structural change and the presence of fatty liver; 2) any possible metabolic risk factor. Patients and methods: the study population consisted of 156 children (71 girls), whose BMI z-score was 4.5±1.4 and their mean age was 8.2±2.7 years. They all underwent ultrasonography to measure the intima-media thickness (IMT) of carotids and to study the morphology of the liver. Their serum glucose, insulin, HOMA index, lipids, TNF-α were measured as well. For those who gave their consent (70 pts), 6-keto PGF 1α was also evaluated. Results: according to IMT measurement, patients were divided in Group A (0.6-0.7 mm) with a BMI z-score of 4.6±1.4* and Group B (0.4-0.5 mm) with a BMI z-score of 4.1±0.9* (*p= 0.2). Their data are reported in Table 1. Liver steatosis was present in 23/76 pts of Group A (30.2%) and in 11/80 pts of Group B (13.7%) Conclusions: Increased carotid IMT was documented in 76/156 children (48.7%) and fatty liver in 34/156 (21.8%). Fasting insulin levels, HOMA index, triglyceride levels and 6-Keto-PGF1α were significantly different between Group A and Group B. These data might suggest that higher insulin resistance and triglyceride levels, together with low levels of 6-keto PGF 1α could be considered risk factors for early vascular damage and hepatic steatosis in obese children.

Acyl chain-dependent effect of lysophosphatidylcholine on endothelial prostacyclin production

Previously we identified palmitoyl-lysophosphatidylcholine (16:0 LPC), linoleoyl-LPC (18:2 LPC), arachidonoyl-LPC (20:4 LPC), and oleoyl-LPC (18:1 LPC) as the most prominent LPC species generated by the action of endothelial lipase (EL) on high-density lipoprotein. In the present study, the impact of those LPC on prostacyclin (PGI(2)) production was examined in vitro in primary human aortic endothelial cells (HAEC) and in vivo in mice. Although 18:2 LPC was inactive, 16:0, 18:1, and 20:4 LPC induced PGI(2) production in HAEC by 1.4-, 3-, and 8.3-fold, respectively. LPC-elicited 6-keto PGF1α formation depended on both cyclooxygenase (COX)-1 and COX-2 and on the activity of cytosolic phospholipase type IVA (cPLA2). The LPC-induced, cPLA2-dependent (14)C-arachidonic acid (AA) release was increased 4.5-fold with 16:0, 2-fold with 18:1, and 2.7-fold with 20:4 LPC, respectively, and related to the ability of LPC to increase cytosolic Ca(2+) concentration. In vivo, LPC increased 6-keto PGF(1α) concentration in mouse plasma with a similar order of potency as found in HAEC. Our results indicate that the tested LPC species are capable of eliciting production of PGI(2), whereby the efficacy and the relative contribution of underlying mechanisms are strongly related to acyl-chain length and degree of saturation.

PP30 LOW LEVELS OF 6-KETO PGF 1α AND INCREASED CAROTID INTIMA–MEDIA THICKNESS IN OBESE CHILDREN WITH INSULIN RESISTANCE

PP30 – Table 1 Glucose Insulin HOMA Cholesterol Triglyceride TNF-α 6-keto PG (mg/dl) (μUI/ml) (mg/dl) (mg/dl) (pg/ml) (pg/ml) Group A (76 pts) 89.3±6.6 14.6±7.7 3.2±1.7 161±29 105.4±60 10.1±5.4 185.1±24.1 (44 pts) Group B (80 pts) 88.0±8.5 11.0±5.8 2.4±1.3 162±32 85.4±50 14±7.5 492.6±91.8 (26 pts) p NS 0.001 0.002 NS 0.025 NS 0.002 and cirrhosis) usually occur in middle and late age, atherosclerotic process in the vascular wall and liver damage might begin very early in obese children. Aim of the study: was to investigate, in children attending our outpatient clinic for obesity, 1) any early vascular structural change and the presence of fatty liver; 2) any possible metabolic risk factor. Patients and methods: the study population consisted of 156 children (71 girls), whose BMI z-score was 4.5±1.4 and their mean age was 8.2±2.7 years. They all underwent ultrasonography to measure the intima-media thickness (IMT) of carotids and to study the morphology of the liver. Their serum glucose, insulin, HOMA index, lipids, TNF-α were measured as well. For those who gave their consent (70 pts), 6-keto PGF 1α was also evaluated. Results: according to IMT measurement, patients were divided in Group A (0.6-0.7 mm) with a BMI z-score of 4.6±1.4* and Group B (0.4-0.5 mm) with a BMI z-score of 4.1±0.9* (*p= 0.2). Their data are reported in Table 1. Liver steatosis was present in 23/76 pts of Group A (30.2%) and in 11/80 pts of Group B (13.7%) Conclusions: Increased carotid IMT was documented in 76/156 children (48.7%) and fatty liver in 34/156 (21.8%). Fasting insulin levels, HOMA index, triglyceride levels and 6-Keto-PGF1α were significantly different between Group A and Group B. These data might suggest that higher insulin resistance and triglyceride levels, together with low levels of 6-keto PGF 1α could be considered risk factors for early vascular damage and hepatic steatosis in obese children.

Development and Characterization of New Inhibitors of the Human and Mouse Hematopoietic Prostaglandin D2 Synthases

The hematopoietic prostaglandin D(2) synthase has a proinflammatory effect in a range of diseases, including allergic asthma, where its product prostaglandin D(2) (PGD(2)) has a role in regulating many of the hallmark disease characteristics. Here we describe the development and characterization of a novel series of hematopoietic prostaglandin D(2) synthase inhibitors with potency similar to that of known inhibitors. Compounds N-benzhydryl-5-(3-hydroxyphenyl)thiophene-2-carboxamide (compound 8) and N-(1-amino-1-oxo-3-phenylpropan-2-yl)-6-(thiophen-2-yl)nicotinamide (compound 34) demonstrated low micromolar potency in the inhibition of the purified enzyme, while only 34 reduced Toll-like receptor (TLR) inducible PGD(2) production in both mouse primary bone marrow-derived macrophages and the human megakaryocytic cell line MEG-01S. Importantly, 34 demonstrated a greater selectivity for inhibition of PGD(2) synthesis versus other eicosanoids that lie downstream of PGH(2) (PGE(2) and markers of prostacyclin (6-keto PGF(1alpha)) and thromboxane (TXB(2))) when compared to the known inhibitors HQL-79 (compound 1) and 2-phenyl-5-(1H-pyrazol-3-yl)thiazole (compound 2). Compound 34 therefore represents a selective hematopoietic prostaglandin D(2) synthase inhibitor.

Quantification of urinary PGEm, 6-keto PGF 1α and 2,3-dinor-6-keto PGF 1α by UFLC–MS/MS before and after exercise

Eicosanoids play an important role in the evaluation of pro-inflammatory responses and in the safety and toxicity of novel therapeutic agents. This work describes a high-throughput UFLCMS/MS method for the analysis of three urinary prostanoid biomarkers of pro-inflammatory responses, tetranor PGEm, 6-keto PGF 1α and 2,3-dinor-6-keto PFG 1α. Nine male volunteers of various age and fitness level participated in this study. Six provided pre- and post-exercise samples and three provided intraday samples. Tetranor PGEm and 6-keto PGF 1α increased significantly in patients after exercise ( p < 0.017 and p < 0.029). In individual patient sets, tetranor PGEm levels increased from 1.5- to 6-fold pre- vs. post-exercise, levels of 6-keto PGF 1α increased more dramatically from 2- to 55-fold pre- vs. post-exercise. The prostanoid 2,3-dinor-6-keto PGF 1α remained unchanged post-exercise. Data was normalized to urinary creatinine concentration, which increased approximately 40% post-exercise.

Crocidolite Induces Prostaglandin I2 Release Mediated by Vitronectin Receptor and Cyclooxygenase-2 in Lung Cells

Interstitial lung disease (ILD) produces disruption of alveolar walls with loss of functionality and scar tissue accumulation. Asbestosis is the ILD produced by the inhalation of asbestos fibers. This study attempts to elucidate the role of lung epithelial cells in the generation of asbestos-induced ILD. When exposed to crocidolite LA-4 cells had a decrease in viability and an increase in the release of lactate dehydrogenase (LDH) and 6-keto PGF(1alpha), a PGI(2) metabolite. PGI(2) release was mediated by cyclooxygenase-2 (COX-2) and vitronectin receptor (VNR). When LA-4 cells were treated with VNR inhibitors, either RGD (Arg-Gly-Asp) peptide or VNR blocking antibody, a statistically significant decrease in PGI(2) metabolite production was observed, but crocidolite-induced cytotoxicity was not prevented. These findings propose that crocidolite is coated by an RGD protein and binds VNR-inducing COX-2 expression and PGI(2) release. Moreover, when LA-4 cells were exposed to crocidolite in the presence of reduced serum culture media, PGI(2) production was prevented, and when bronchoalveolar lavage fluid (BALF) was added, PGI(2) production was rescued. Cytotoxicity did not occur, either in reduced serum culture media or when BALF was added. In conclusion, crocidolite requires the presence of an RGD protein coating the fibers to induce inflammation (PGI(2) production) and crocidolite alone cannot induce cytotoxicity in lung cells.

Selective inducible microsomal prostaglandin E 2 synthase-1 (mPGES-1) inhibitors derived from an oxicam template

Here we describe the SAR of a series of potent and selective mPGES-1 inhibitors based on an oxicam template. Compound 13j demonstrated low nanomolar mPGES-1 inhibition in an enzyme assay. In addition, it displayed PGE 2 inhibition in a cell-based assay (0.42 μM) and had over 238-fold selectivity for mPGES-1 over COX-2 and over 200-fold selectivity for mPGES-1 over 6-keto PGF 1α.

The Molecular Pharmacology and In Vivo Activity of 2-(4-Chloro-6-(2,3-dimethylphenylamino)pyrimidin-2-ylthio)octanoic acid (YS121), a Dual Inhibitor of Microsomal Prostaglandin E2 Synthase-1 and 5-Lipoxygenase

The microsomal prostaglandin E(2) synthase (mPGES)-1 is one of the terminal isoenzymes of prostaglandin (PG) E(2) biosynthesis. Pharmacological inhibitors of mPGES-1 are proposed as an alternative to nonsteroidal anti-inflammatory drugs. We recently presented the design and synthesis of a series of pirinixic acid derivatives that dually inhibit mPGES-1 and 5-lipoxygenase. Here, we investigated the mechanism of mPGES-1 inhibition, the selectivity profile, and the in vivo activity of alpha-(n-hexyl)-substituted pirinixic acid [YS121; 2-(4-chloro-6-(2,3-dimethylphenylamino)pyrimidin-2-ylthio)octanoic acid)] as a lead compound. In cell-free assays, YS121 inhibited human mPGES-1 in a reversible and noncompetitive manner (IC(50) = 3.4 muM), and surface plasmon resonance spectroscopy studies using purified in vitro-translated human mPGES-1 indicate direct, reversible, and specific binding to mPGES-1 (K(D) = 10-14 muM). In lipopolysaccharide-stimulated human whole blood, PGE(2) formation was concentration dependently inhibited (IC(50) = 2 muM), whereas concomitant generation of the cyclooxygenase (COX)-2-derived thromboxane B(2) and 6-keto PGF(1alpha) and the COX-1-derived 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid was not significantly reduced. In carrageenan-induced rat pleurisy, YS121 (1.5 mg/kg i.p.) blocked exudate formation and leukocyte infiltration accompanied by reduced pleural levels of PGE(2) and leukotriene B(4) but also of 6-keto PGF(1alpha). Taken together, these results indicate that YS121 is a promising inhibitor of mPGES-1 with anti-inflammatory efficiency in human whole blood as well as in vivo.

Green tea epigallocatechin-3-gallate inhibits microsomal prostaglandin E 2 synthase-1

Prostaglandin (PG)E 2 is a critical lipid mediator connecting chronic inflammation to cancer. The anti-carcinogenic epigallocatechin-3-gallate (EGCG) from green tea ( Camellia sinensis) suppresses cellular PGE 2 biosynthesis, but the underlying molecular mechanisms are unclear. Here, we investigated the interference of EGCG with enzymes involved in PGE 2 biosynthesis, namely cytosolic phospholipase (cPL)A 2, cyclooxygenase (COX)-1 and -2, and microsomal prostaglandin E 2 synthase-1 (mPGES-1). EGCG failed to significantly inhibit isolated COX-2 and cPLA 2 up to 30 μM and moderately blocked isolated COX-1 (IC 50 > 30 μM). However, EGCG efficiently inhibited the transformation of PGH 2 to PGE 2 catalyzed by mPGES-1 (IC 50 = 1.8 μM). In lipopolysaccharide-stimulated human whole blood, EGCG significantly inhibited PGE 2 generation, whereas the concomitant synthesis of other prostanoids (i.e., 12( S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid and 6-keto PGF 1α) was not suppressed. Conclusively, mPGES-1 is a molecular target of EGCG, and inhibition of mPGES-1 is seemingly the predominant mechanism underlying suppression of cellular PGE 2 biosynthesis by EGCG.

Inhibition of prostaglandin E 2 signaling through the EP 1 receptor does not affect prostacyclin production in human endothelial cells

Accumulating evidence suggests that cyclooxygenase-2 (COX-2) and prostaglandin E 2 (PGE 2) may play an important role in colon carcinogenesis. Thus, blockage of this pathway may be a suitable strategy for colon cancer chemoprevention. Recent clinical studies suggest that COX-2 inhibitors cause adverse cardiovascular effects due to prostacyclin (PGI 2) inhibition. To test our hypothesis that inhibition of PGE 2 signaling through E-prostanoid (EP) receptors may offer a safer cardiovascular profile than COX-2 inhibition, we analyzed expression of 6-keto PGF 1α, a hydrated form of PGI 2 and PGI 2 synthase, which was stimulated with cytokines in human umbilical vein endothelial cells (HUVECs) treated with the EP 1 receptor antagonist ONO-8711 or the COX-2 inhibitor celecoxib. ONO-8711 did not inhibit both 6-keto PGF 1α production and PGIS expression, whereas celecoxib did in HUVECs. ONO-8711 also inhibited cytokine-induced tissue factor expression in HUVECs. These results suggest that ONO-8711 may be a safer chemopreventive agent with respect to cardiovascular events.