Alpha-Synuclein, cyclooxygenase-2 and prostaglandins-EP2 receptors as neuroinflammatory biomarkers of autism spectrum disorders: Use of combined ROC curves to increase their diagnostic values

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interaction and restricted and repetitive behaviors. Neuroinflammation and abnormal lipid mediators have been identified in multiple investigations as an acknowledged etiological mechanism of ASD that can be targeted for therapeutic intervention.

METHODS

In this study, multiple regression and combined receiver operating characteristic (ROC) curve analyses were used to determine the relationship between the neuroinflammatory marker α-synuclein and lipid mediator markers related to inflammation induction, such as cyclooxygenase-2 and prostaglandin-EP2 receptors, in the etiology of ASD. Additionally, the study aimed to determine the linear combination that maximizes the partial area under ROC curves for a set of markers. Forty children with ASD and 40 age- and sex-matched controls were enrolled in the study. Using ELISA, the levels of α-synuclein, cyclo-oxygenase-2, and prostaglandin-EP2 receptors were measured in the plasma of both groups. Statistical analyses using ROC curves and multiple and logistic regression models were performed.

RESULTS

A remarkable increase in the area under the curve was observed using combined ROC curve analyses. Moreover, higher specificity and sensitivity of the combined markers were reported.

CONCLUSIONS

The present study indicates that measurement of the predictive value of selected biomarkers related to neuroinflammation and lipid metabolism in children with ASD using a ROC curve analysis should lead to a better understanding of the etiological mechanism of ASD and its link with metabolism. This information may facilitate early diagnosis and intervention.

Effect of Papaya Leaves (<i>Carica papaya</i> L.) Extract on Immune Response (TLR-7, TLR-9) and Inflammation (COX-2) in Rats Induces DMBA (7,12-Dimethylbenz[a]antrasen)

BACKGROUND AND OBJECTIVE

TLR is known to regulate the immune system in cancer. TLR-7 and TLR-9 can enhance the antitumor immune system in many types of solid tumors. Cyclooxygenase-2 (COX-2) is a biomarker of inflammation. This study aimed to investigate the effect of papaya leaves extract on immune response (TLR 7, TLR 9) and inflammation (COX-2) in rats induced DMBA.

MATERIALS AND METHODS

This experimental study used Sprague dawley female rats of age more less 50 days. Rats were divided into 4 groups: Negative Control (NC), Positive Control (PC), Cancer Drug Doxorubicin (DOXO) and Papaya Leaves Extract (PLE). The study was conducted for 13 weeks. DMBA induction performed for 5 weeks with administration of 2 times per week.

RESULTS

the expression of TLR-7 of PLE and DOXO was higher than PC groups significantly different (p<0.05). The expression of TLR-9 of PLE was higher than NC, PC and DOXO groups but not significantly different (p>0.05) while the expression of COX-2 of PLE and DOXO groups was lower than NC and PC groups but not significantly different (p>0.05).

CONCLUSION

It can be concluded that papaya leaves extract can improve the immune system and reduce inflammation. It shows that papaya leaves extract has potent as anti-cancer.

Physiologically relevant aspirin concentrations trigger immunostimulatory cytokine production by human leukocytes

Acetylsalicylic acid is a globally used non-steroidal anti-inflammatory drug (NSAID) with diverse pharmacological properties, although its mechanism of immune regulation during inflammation (especially at in vivo relevant doses) remains largely speculative. Given the increase in clinical perspective of Acetylsalicylic acid in various diseases and cancer prevention, this study aimed to investigate the immunomodulatory role of physiological Acetylsalicylic acid concentrations (0.005, 0.02 and 0.2 mg/ml) in a human whole blood of infection-induced inflammation. We describe a simple, highly reliable whole blood assay using an array of toll-like receptor (TLR) ligands 1–9 in order to systematically explore the immunomodulatory activity of Acetylsalicylic acid plasma concentrations in physiologically relevant conditions. Release of inflammatory cytokines and production of prostaglandin E₂ (PGE₂) were determined directly in plasma supernatant. Experiments demonstrate for the first time that plasma concentrations of Acetylsalicylic acid significantly increased TLR ligand-triggered IL-1β, IL-10, and IL-6 production in a dose-dependent manner. In contrast, indomethacin did not exhibit this capacity, whereas cyclooxygenase (COX)-2 selective NSAID, celecoxib, induced a similar pattern like Acetylsalicylic acid, suggesting a possible relevance of COX-2. Accordingly, we found that exogenous addition of COX downstream product, PGE₂, attenuates the TLR ligand-mediated cytokine secretion by augmenting production of anti-inflammatory cytokines and inhibiting release of pro-inflammatory cytokines. Low PGE₂ levels were at least involved in the enhanced IL-1β production by Acetylsalicylic acid.

Emodin protects knee joint cartilage in rats through anti-matrix degradation pathway: An in vitro and in vivo study

AIMS

Osteoarthritis (OA) is a common joint disease and the main cause of disability. We sought to determine the effective concentration of emodin on chondrocytes and to identify the dosage of emodin that induces a comparable therapeutic effect with the COX-2 inhibitor drug, celecoxib that is currently used to treat OA.

MATERIAL AND METHODS

In vitro experiments induced inflammation of chondrocytes by IL-1β, and an osteoarthritis model was established in vivo by cutting rat anterior cruciate ligament. Western Blot, Real-time PCR, HE staining, Safranin O-green staining and immunohistochemistry were performed to detect MMP-3, MMP-13, ADAMTS-4, iNOS and COL2A1 on the chondrocytes or the tibial plateau. The cytokine activity and content in serum of six groups of rats were measured by kit.

RESULTS

It was found that the surface layer of the cartilage was thicker and smoother after the administration of emodin. Tissue expression of MMP-3, MMP-13, ADAMTS-4 and iNOS were significantly (p < 0.05) decreased in chondrocytes and cartilage treated with different doses of emodin, and the content of COL2A1 was reversed. Emodin also significantly decreased the blood levels of COX-2 and PGE2. The effective emodin in vitro was 5 μmol/L, whereas emodin at 80 mg/kg was equivalent to celecoxib in vivo.

CONCLUSION

Emodin reduces the expression of cartilage matrix degradation biomarkers, thereby reducing the degradation of cartilage matrix and protecting the knee joint cartilage. Emodin at 5 μmol/L shows the best concentration to treat chondrocytes, and the protective effect of emodin at 80 mg/kg is comparable to that of celecoxib.

The Arachidonic Acid Metabolism Mechanism Based on UPLC-MS/MS Metabolomics in Recurrent Spontaneous Abortion Rats

Recurrent spontaneous abortion (RSA) remains a critical and challenging problem in reproduction. To discover novel biomarkers for RSA, ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) metabolomics approach was applied to detect RSA serum metabolic profiles and explore its possible pathogenesis and mechanism. The abortion rat model was established, and a metabolomics analysis was performed to evaluate the differentially expressed metabolites between the control and model groups. Immunohistochemistry (IHC), qRT-PCR, and Western blot further examined the expression of Arachidonic acid metabolism-related genes in uterus tissues. To identify arachidonic acid metabolism-related changes in RSA, ELISA's potential mechanisms were further confirmed in serum. Ninety-one metabolites were significantly different between the two groups, as indicated by a VIP ≥1, fold change ≥1. The metabolic pathways involving arachidonic acid metabolism pathway (P = 0.00044) are related to RSA. Verification by experimental showed that compared with the control rats, the expression of the COX-1, COX-2, PTGFR, and TBXA2R genes associated with the arachidonic acid metabolism pathway has significantly increased the uterus and serum of RSA rats (P < 0.05). Regulation of the arachidonic acid metabolism pathway might serve as a promising therapeutic strategy for relieving RSA women's symptoms.

Tuling Wendan Decoction combined with flunarizine in the treatment of migraine patients and the effect of intervention on serum cyclooxygenase-2, endothelin-1 and nitric oxide

This experiment aimed to explore the curative effect of Tuling Wendan Decoction combined with flunarizine on migraine patients and the intervention effect on serum cyclooxygenase-2 (COX-2), endothelin-1 (ET-1), nitric oxide(NO) levels. For this purpose, from January 2019 to January 2020, 96 patients with migraine in our hospital were selected as the research object. Using a simple randomization method, patients who meet the criteria were assigned 1:1, and each patient was assigned a random number, of which the number 1 to 48 were the observation group, and the number 49 to 96 were the control group. The control group was treated with flunarizine, and the observation group was treated with Tuling Wendan Decoction combined with flunarizine. Comparing the efficacy, incidence of adverse reactions, the incidence of headache, cerebral blood flow rate [basal artery (BA), vertebral artery (VA), middle cerebral artery (MCA)], vascular endothelial function (serum COX-2, ET-1, NO levels), neurological function [5-hydroxytryptamine (5-HT), brain-derived neurotrophic factor (BDNF), calcitonin gene-related peptide (CGRP)] before treatment, 4 weeks and 8 weeks after treatment between the two groups. The results for efficacy showed that after 8 weeks of treatment, the total effective rate of the observation group (93.75%) was higher than that of the control group (77.08%, P&lt;0.05). In regards to the situation of headache attack, the number of headache attacks, duration, pain degree and accompanying symptom scores of the observation group after 4 weeks and 8 weeks of treatment were lower than those of the control group (P&lt;0.05). Results of cerebral blood flow velocity showed that the blood flow velocity of BA, VA, MCA in the observation group was lower than that in the control group after 4 and 8 weeks of treatment (P&lt;0.05). Vascular endothelial function results indicated that the serum COX-2 and ET-1 levels of the observation group were lower than those of the control group after 4 weeks and 8 weeks of treatment, and the serum NO levels were higher than that of the control group (P&lt;0.05). The serum BDNF and CGRP levels of the observation group were lower than those of the control group after 4 weeks and 8 weeks of treatment, and the serum 5-HT levels were higher than the control group (P&lt;0.05). The incidence of adverse reactions between the two groups was not statistically significant (P&gt;0.05). It was concluded that Tuling Wendan Decoction combined with flunarizine is the first treatment for migraine, with definite curative effect and can effectively improve the onset of headache, reduce the speed of cerebral blood flow, regulate vascular endothelial function and nerve function, and ensure safety.

The Inhibitory Effect of Extra Virgin Olive Oil and Its Active Compound Oleocanthal on Prostaglandin-Induced Uterine Hypercontraction and Pain-Ex Vivo and In Vivo Study

Primary dysmenorrhea is a common occurrence in adolescent women and is a type of chronic inflammation. Dysmenorrhea is due to an increase in oxidative stress, which increases cyclooxygenase-2 (COX-2) expression, increases the concentration of prostaglandin F2α (PGF2α), and increases the calcium concentration in uterine smooth muscle, causing excessive uterine contractions and pain. The polyphenolic compound oleocanthal (OC) in extra virgin olive oil (EVOO) has been shown to have an anti-inflammatory and antioxidant effect. This study aimed to investigate the inhibitory effect of extra virgin olive oil and its active ingredient oleocanthal (OC) on prostaglandin-induced uterine hyper-contraction, its antioxidant ability, and related mechanisms. We used force-displacement transducers to calculate uterine contraction in an ex vivo study. To analyze the analgesic effect, in an in vivo study, we used an acetic acid/oxytocin-induced mice writhing model and determined uterus contraction-related signaling protein expression. The active compound OC inhibited calcium/PGF2α-induced uterine hyper-contraction. In the acetic acid and oxytocin-induced mice writhing model, the intervention of the EVOO acetonitrile layer extraction inhibited pain by inhibiting oxidative stress and the phosphorylation of the protein kinase C (PKC)/extracellular signal-regulated kinases (ERK)/ myosin light chain (MLC) signaling pathway. These findings supported the idea that EVOO and its active ingredient, OC, can effectively decrease oxidative stress and PGF2α-induced uterine hyper-contraction, representing a further treatment for dysmenorrhea.

What about COVID-19 and arachidonic acid pathway?

Background and objective

COVID-19 is a highly contagious viral disease. In this study, we tried to define and discuss all the findings on the potential association between arachidonic acid (AA) pathway and COVID-19 pathophysiology.

Methods

A literature search across PubMed, Scopus, Embase, and Cochrane database was conducted. A total of 25 studies were identified.

Results

The data elucidated that COX-2 and prostaglandins (PGs), particularly PGE₂, have pro-inflammatory action in COVID-19 pathophysiology. Arachidonic acid can act as endogenous antiviral compound. A deficiency in AA can make humans more susceptible to COVID-19. Targeting these pro-inflammatory mediators may help in decreasing the mortality and morbidity rate in COVID-19 patients.

Conclusions

PGE₂ levels and other PGs levels should be measured in patients with COVID-19. Lowering the PGE₂ levels through inhibition of human microsomal prostaglandin E synthase-1 (mPGES-1) can enhance the host immune response against COVID-19. In addition, the hybrid compounds, such as COX-2 inhibitors/TP antagonists, can be an innovative treatment to control the overall balance between AA mediators in patients with COVID-19.

High sPLA2-IIA level is associated with eicosanoid metabolism in patients with bacterial sepsis syndrome

The aim of this study was to determine the association between secretory phospholipase A2 group IIA (sPLA2-IIA) and eicosanoid pathway metabolites in patients with bacterial sepsis syndrome (BSS). Levels of sPLA2-IIA, eicosanoids prostaglandin (PG)E2, PGD synthase were quantified in the sera from patients confirmed to have bacterial sepsis (BS; N = 45), bacterial severe sepsis/septic shock (BSS/SS; N = 35) and healthy subjects (N = 45). Cyclooxygenase (COX)-1 and COX-2 activities were analyzed from cell lysate. Serum levels of sPLA2-IIA, PGE2, and PGDS increased significantly in patients with BS and BSS/SS compared to healthy subjects (p<0.05). COX-2 activity was significantly increased in patients with BS compared to healthy subjects (p<0.05), but not COX-1 activity. Binary logistic regression analysis showed that sPLA2-IIA and PGE2 were independent factors predicting BSS severity. In conclusion, high level of sPLA2-IIA is associated with eicosanoid metabolism in patients with BSS.

Maternal vitamin D deficiency increases the thromboxane/prostacyclin ratio through alterations in the one-carbon cycle in Wistar rats

This study aims to test the hypothesis that vitamin D deficiency can influence long-chain polyunsaturated fatty acid metabolism through alterations in the one-carbon cycle. Wistar rats (n = 8 per group) were given either a control (1,000 IU D3/kg diet) or a vitamin D deficient (VDD) (0 IU D3/kg diet) diet from pre-pregnancy to delivery. On day 20 of gestation, pregnant female rats were delivered by C-section to collect placenta and blood. VDD group demonstrated high serum parathyroid hormone, low serum phosphate, low plasma folate, higher plasma homocysteine, and higher plasma malondialdehyde levels (P < 0.05 for all) as compared to control. Lower protein levels of placental cystathionine-β-synthase enzyme (P < 0.05) were observed in the VDD group as compared to control. VDD group demonstrated higher placental mRNA levels of the enzymes phospholipase A₂ and cyclooxygenase-2 (P < 0.05 for both) as compared to control. Protein levels of the enzymes phospholipase A₂ and cyclooxygenase-2 were lower (P < 0.05 for both) in the VDD group as compared to the control group. The ratio of thromboxane B₂ and 6-keto prostaglandin F_1α in serum was higher (P < 0.05) in the VDD group as compared to control; although the serum levels of 6-keto prostaglandin F_1α and thromboxane B₂ were similar in both the groups. Our findings suggest that increased oxidative stress due to maternal vitamin D deficiency results in the imbalance between the vasoconstrictor (thromboxane B₂ ) and vasodilator (6-keto prostaglandin F_1α ) eicosanoids, which may lead to endothelial dysfunction and poor pregnancy outcome. © 2019 BioFactors, 45 (4):548-555, 2019.

Ribes orientale: A novel therapeutic approach targeting rheumatoid arthritis with reference to pro-inflammatory cytokines, inflammatory enzymes and anti-inflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

The roots of Ribes orientale (Family Grossulariaceae) have long been used as a folk remedy to treat rheumatism and joints pain in Northern Areas of Pakistan.

AIM OF THE STUDY

The purpose of study was to observe the preventive efficacy of roots of Ribes orientale (RO) aqueous ethanolic extract (30:70) and its aqueous and n-butanol fractions in treating rheumatoid arthritis and to determine its possible mechanism of action.

MATERIAL AND METHODS

Arthritis was evaluated in vitro using heat induced bovine serum albumin and egg albumin denaturation and membrane stabilizing assays at 50-6400 μg/ml concentration of extract/fractions whereas, in vivo arthritis was evaluated at 50, 100, 200 mg/kg doses of extract/fractions in formaldehyde model by measuring rat paw volume/diameter. Moreover, highest effective dose (200 mg/kg) of extract/fractions was evaluated in Freünd complete adjuvant (FCA) model. Arthritis was induced in Sprague Dawley rats by immunization with 0.1 ml FCA in left footpad. RO extract/fractions at 200 mg/kg were orally administered from day 0, 30 min prior to adjuvant injection and sustained for 28 days. Paw volume/diameter, arthritic score, body weight, and hematological (WBC, RBC, ESR, Hb and Platelet count) and biochemical (AST, ALT, ALP, urea, creatinine, CRP and RF) parameters were observed. The mRNA expression levels of COX-2, IL-1β, IL-6, NF-kB, TNF-α, IL-4 and IL-10 were measured by real time reverse transcription polymerase chain reaction (RT-PCR) whereas, PGE2 and TNF-α levels in serum samples were measured by Enzyme linked immunosorbent assay (ELISA). Furthermore, radiographs of hind paws and histological changes in ankle joint were analyzed in adjuvant injected rats. The anti-oxidant activity of plant extract and fractions was evaluated using DPPH and reducing power assays. In addition, phytochemistry, total phenolic and flavonoid contents, and HPLC analysis of most active fraction (aqueous fraction) were performed.

RESULTS

Results showed that RO extract and fractions (notably aqueous fraction) significantly reduced protein denaturation and protected erythrocyte membrane in concentration dependent manner. Similarly, extract/fractions induced dose-dependent decrease in paw volume/diameter in the formaldehyde model. Plant extract and fractions significantly suppressed paw swelling and arthritic score, prevented cachexia and remarkably ameliorated hematological and biochemical changes. Furthermore, RO extract/fractions downregulated gene expression levels of PGE2, COX-2, IL-1β, IL-6, NF-kB and TNF-α whereas, upregulated those of IL-4 and IL-10, compared with FCA control rats. The radiographic and histopathologic improvement in joint architecture was also observed in RO treated rats. Piroxicam, used as reference drug, also significantly suppressed arthritis. Additionally, plant exhibited notable anti-oxidant activity and phytochemical analysis revealed the presence of flavonoids and polyphenols.

CONCLUSION

Results indicated that suppression of pro-inflammatory enzymes/cytokines, inhibition of protein denaturation, lysosomal membrane stabilizing abilities, and redox/free radical scavenging properties of RO extract and fractions support anti-arthritic and immunomodulatory property of Ribes orientale that might be due to its polyphenolic and flavonoid constituents. This suggests that Ribes orientale roots may be used as a therapeutic agent for treating human arthritis.

Impaired lipid metabolism markers to assess the risk of neuroinflammation in autism spectrum disorder

Autism spectrum disorder (ASD) is a multifactorial disorder caused by an interaction between environmental risk factors and a genetic background. It is characterized by impairment in communication, social interaction, repetitive behavior, and sensory processing. The etiology of ASD is still not fully understood, and the role of neuroinflammation in autism behaviors needs to be further investigated. The aim of the present study was to test the possible association between prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-1 (mPGES-1), prostaglandin PGE2 EP2 receptors and nuclear kappa B (NF-κB) and the severity of cognitive disorders, social impairment, and sensory dysfunction. PGE2, COX-2, mPGES-1, PGE2-EP2 receptors and NF-κB as biochemical parameters related to neuroinflammation were determined in the plasma of 47 Saudi male patients with ASD, categorized as mild to moderate and severe as indicated by the Childhood Autism Rating Scale (CARS) or the Social Responsiveness Scale (SRS) or the Short Sensory Profile (SSP) and compared to 46 neurotypical controls. The data indicated that ASD patients have remarkably higher levels of the measured parameters compared to neurotypical controls, except for EP2 receptors that showed an opposite trend. While the measured parameter did not correlate with the severity of social and cognitive dysfunction, PGE2, COX-2, and mPGES-1 were remarkably associated with the dysfunction in sensory processing. NF-κB was significantly increased in relation to age. Based on the discussed data, the positive correlation between PGE2, COX-2, and mPGES-1 confirm the role of PGE2 pathway and neuroinflammation in the etiology of ASD, and the possibility of using PGE2, COX-2 and mPGES-1 as biomarkers of autism severity. NF-κB as inflammatory inducer showed an elevated level in plasma of ASD individuals. Receiver operating characteristic analysis together with predictiveness diagrams proved that the measured parameters could be used as predictive biomarkers of biochemical correlates to ASD.

Increased Levels of Txa₂ Induced by Dengue Virus Infection in IgM Positive Individuals Is Related to the Mild Symptoms of Dengue

The inflammatory process plays a major role in the prognosis of dengue. In this context, the eicosanoids may have considerable influence on the regulation of the Dengue virus-induced inflammatory process. To quantify the molecules involved in the cyclooxygenase and lipoxygenase pathways during Dengue virus infection, plasma levels of thromboxane A2, prostaglandin E2 and leukotriene B4; mRNA levels of thromboxane A2 synthase, prostaglandin E2 synthase, leukotriene A4 hydrolase, cyclooxygenase-2 and 5-lipoxygenase; and the levels of lipid bodies in peripheral blood leukocytes collected from IgM-positive and IgM-negative volunteers with mild dengue, and non-infected volunteers, were evaluated. Dengue virus infection increases the levels of thromboxane A2 in IgM-positive individuals as well as the amount of lipid bodies in monocytes in IgM-negative individuals. We suggest that increased levels of thromboxane A2 in IgM-positive individuals plays a protective role against the development of severe symptoms of dengue, such as vascular leakage.

Effects of Supervised Structured Aerobic Exercise Training Program on Interleukin-6, Nitric Oxide Synthase-1, and Cyclooxygenase-2 in Type 2 Diabetes Mellitus

OBJECTIVE

To determine the effects of supervised structured aerobic exercise training (SSAET) program on interleukin-6 (IL-6), nitric oxide synthase 1 (NOS-1), and cyclooxygenase-2 (COX-2) in type 2 diabetes mellitus (T2DM).

STUDY DESIGN

Randomized controlled trial.

PLACE AND DURATION OF STUDY

Riphah Rehabilitation and Research Centre, Railways General Hospital, Rawalpindi, from January 2015 to June 2016.

METHODOLOGY

Patients of either gender of minimum one year history of T2DM ranging from 40-70 years of age were included. Those with chronic systemic diseases, history of regular exercise, smoking, and those on dietary plan were excluded. Atotal of 195 patients were screened; 120 were selected and 102 agreed to participate in the study. They were randomly placed into experimental and control groups. SSAETprogram, routine medication, and dietary plan were applied in experimental group; whereas, control group was managed with routine medication and dietary plan for 25 weeks. IL-6, NOS-1, and COX-2 were assessed at baseline and 25 weeks.

RESULTS

SSAET program, routine medication and dietary plan showed significantly improved IL-6 (pre-mean=0.25 ±0.11ng/ml, post-mean=0.19 ±0.04 ng/ml), NOS-1 (pre-median=4.65 ng/ml, IQ range=1.04 ng/ml), (post-median=2.72 ng/ml, IQ range=1.60 ng/ml), and COX-2 (pre-mean=18.72 ±4.42 ng/ml, post-mean=15.18 ±2.63 ng/ml) in experimental group, as compared with control group managed by routine medication and dietary plan, where deterioration was noted in IL-6 (pre-mean=0.23 ±0.08 ng/ml, post-mean=0.27 ±0.08 ng/ml) and COX-2 (pre-mean=18.49 ±4.56 ng/ml, postmean=19.10 ±4.76 ng/ml), while NOS-1 slight improvement (pre-mean=4.99 ng/ml, IQ range=2.67 ng/ml), (postmean=4.56 ng/ml, IQ range=3.85 ng/ml). Statistically at the baseline the p-values were not significant (p>0.05) in both experimental and control groups for IL-6, COX-2 and NOS-1; while after 25 weeks of intervention, the experimental group showed significant improvement (p<0.05) in comparison with the control group.

CONCLUSION

SSAET program, routine medication, and dietary plan had positive effect on IL-6, NOS-1, and COX-2 in T2DM patients.

Human apolipoprotein A-I exerts a prophylactic effect on high-fat diet-induced atherosclerosis via inflammation inhibition in a rabbit model

Apolipoprotein A-I (apoA-I) is the major functional protein fraction of high-density lipoprotein. The prophylactic effect and mechanism of human apoA-I on atherosclerosis (AS) were investigated in a high-fat diet-induced AS rabbit model. The rabbits were injected with apoA-I once a week while fed high-fat diet for 20 weeks. Our results showed that apoA-I could raise the serum level of high-density lipoprotein-cholesterol and reduce those of lipid total cholesterol, triglyceride, and low-density lipoprotein-cholesterol in AS rabbits. Decreased aortic plaque area and aortic injury degree were also observed by Oil Red O staining and HE staining in apoA-I-treated high-fat diet-induced AS rabbits. Further study elucidated that apoA-I could down-regulate the expression of some inflammatory mediators including intercellular adhesion molecule type 1, vascular adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1, tumor necrosis factor-α, interleukin-6 (IL-6), and C-reactive protein in serum and aorta of AS rabbits. In addition, real-time quantitative RT-PCR analyses showed that the apoA-I infusions decreased the mRNA levels of two pro-inflammatory molecules, i.e. nuclear factor kappa B (NF-κB) and cyclooxygenase-2 (COX-2), in aorta of AS rabbits, which was associated with a concomitant reduction in endothelial VCAM-1 and IL-6 mRNA transcription. Together, our results support the atheroprotective and prophylactic role of apoA-I in vivo, and this activity may be correlated with its anti-inflammatory effect.

[Analgesic effects of ionotropic glutamate receptor antagonists MK-801 and NBQX on collagen-induced arthritis rats]

OBJECTIVE

The ionotropic glutamate receptorantagonists include two types: MK-801, antagonist of N-methyl-D-asparticacid (NMDA) receptor, and NBQX, antagonist of non-NMDA receptor.The above-mentioned ionotropic antagonists can block the glutamate and its corresponding receptor binding to produce analgesic effect. The objective of this research was to study two antagonists in analgesic effect on rat behavior,as well as to investigate the down-regulation and up-regulation of cyclooxygenase-2 (COX-2) and Janus-activated kinase (Jak3) in collagen-induced arthritis (CIA) rat serum and tissue fluid after the application of these antagonists, that is, the effect on molecular biology.

METHODS

This study used the ionotropic glutamate receptors as the target and established CIA rat model. Vivo studies were used to observe changes in behavior and molecular biology of the CIA rat.Behavioral assessment includedmechanical allodynia and joint swelling in the CIA rat,where themechanical allodynia was measured using the paw-withdrawal threshold (PWT) with VonFrey filaments according to the "Up-Down" method,and the drainage volume was used to assess joint swelling. Then the blood samples taken from the heart of the rat and the tissue homogenate were collected to detect the down-regulation and up-regulation of COX-2 and Jak3 in the serum and tissue fluid after the antagonists wereused.

RESULTS

Using MK-801, NBQX alone or using the combination of these two antagonists,these three methods all could alleviate pain(P<0.01).The analgesic effect lasted more than 24 h.Both antagonists reached the peak of analgesia at the end of 4 hours post-injection. NBQX had stronger analgesic effect than MK-801 (P<0.05).Whether alone or combined use of these two antagonists,could not change the CIA rats' swelling of the joint (P>0.05). MK-801 could decrease the expression of COX-2 (P<0.01).At the same time, NBQX did not have this effect (P>0.05). Using MK-801, NBQX alone or combination of these two antagonists could not affect the increased expression of Jak3 caused by the CIA (P>0.05).

CONCLUSION

MK-801 and NBQX could both alleviate pain, NBQX was much better than MK-801. Neither MK-801 nor NBQX had the effect on the swelling of the joint. NMDA receptor and COX-2 inflammatory pathways had certain interactions. For Jak3, it could not be found to have cross-function with ionotropic glutamate signaling pathways by this experiment.

[Neoadiuvant teleradiotherapy decreases cancer tissue and serum concentration of prostaglandin E2 and cyclooxygenase-2 expression in patients with rectal cancer]

The carcinogenesis of colorectal cancer involves many factors, which modify the functioning of cells and can include prostaglandins. Resection of tumours and/or radiotherapy provide potentially curative therapy for cancer of the rectum.

AIM

The aim of the study was to asses the effects of neoadiuvant teleradiotherapy on PGE2 concentrations in the serum and in the resected bowel tissue as well as on COX-2 gene expression in patients with rectal cancer.

MATERIALS AND METHODS

Group I (n=20) included patients with resectable tumour (T1-2,No) treated exclusively by surgery, and group II (n=20) - patients with resectable tumours (T3) and nonresectable ones (T4). All the patients out of group II were put to the surgery after the previous teleradiotherapy applied to them. PGE2 concentrations were examined using the RIA method, while COX-2 mRNA expression was analyzed with the use of the PCR method.

RESULTS

PGE2 serum concentrations in the group I prior to the resection did not differ from PGE2 concentrations in the group II prior to the resection (p=0,9488). However, radiation had caused reduction of PGE2 serum concentration prior to the resection in patients from the group II in comparison with the group I (p=0,0115). PGE2 serum concentrations after resection in the group I did not differ significantly from PGE2 concentrations in group II after resection (p=0,4511) (two-factor analysis of variation with interaction, p=0,3117). Radiotherapy did not change significantly PGE2 concentrations in the tumour and margin (two-factor analysis of variations with interaction, p=0,3137). The comparison between the number of patients who showed higher COX-2 mRNA expression in tumour than in the margin in the group I and II, did not reveal differences (p=0,6614).

CONCLUSIONS

Neoadiuvant teleradiotherapy decreased PGE2 concentration in the serum, thus showed similar effect as tumour resection.

Alleviation of cyclophosphamide-induced immunosuppression in Wistar rats by onion lectin (Allium cepa agglutinin)

ETHNOPHARMACOLOGICAL RELEVANCE

In various traditional medicines, onion has been classified as an immune-boosting food. Recent studies have claimed this property due to the presence of bioactive organosulfur compounds, prebiotic fructo-oligosaccharides and an immunomodulatory protein, lectin (Allium cepa agglutinin; ACA) (Prasanna and Venkatesh, 2015. Characterization of onion lectin (Allium cepa agglutinin) as an immunomodulatory protein inducing Th1-type immune response in vitro. Int. Immunopharmacol. vol. 26, pp. 304-313).

AIM OF THE STUDY

The aim of this study was to evaluate the immunoprotective properties of ACA in normal and cyclophosphamide (CP; 100μg/kg)-induced immunosuppressed Wistar rats.

MATERIALS AND METHODS

Wistar rats were administrated different doses of ACA (1, 10, and 100μg) to respective groups in normal as well as immunosuppressed animals. The effect of ACA on the status of immune organs was assessed by examining the splenic and thymic indices, and histopathological changes. The biomarkers for humoral immunity (serum IgG and IgA levels) and serum pro-inflammatory markers (COX-2, TNF-α and IL-10) were measured by ELISA.

RESULTS

ACA showed immunoprotective properties by significantly promoting the restoration of lymphoid cell count by ~6 fold vs. model control (immunosuppressed animals) and promotes the immune response significantly (~1.5-fold) in CP-induced immunosuppressed animals compared to model control; production of pro-inflammatory molecules (COX-2 and nitric oxide) and expression levels of immune regulatory molecule (TNF-α) were elevated in a dose-dependent manner.

CONCLUSIONS

The observed in vivo results suggest that ACA has the potential to be used as a nutritional therapeutic to boost the immune status of immunosuppressed subjects brought about by CP administration.

Licoricidin, an Active Compound in the Hexane/Ethanol Extract of Glycyrrhiza uralensis, Inhibits Lung Metastasis of 4T1 Murine Mammary Carcinoma Cells

Licorice extracts containing glycyrrhizin exhibit anti-carcinogenic properties. Because glycyrrhizin induces severe hypokalemia and hypertension, we prepared a hexane/ethanol extract of Glycyrrhizauralensis (HEGU) that lacks glycyrrhizin, and showed that HEGU induces apoptosis and G1 cell cycle arrest and inhibits migration of DU145 human prostate cancer cells. Our previous in vitro studies identified two active components in HEGU: isoangustone A, which induces apoptosis and G1 cycle arrest, and licoricidin, which inhibits metastasis. This study examined whether HEGU and licoricidin inhibit metastasis using the 4T1 mammary cancer model. Both HEGU and licoricidin treatment reduced pulmonary metastasis and the expression of CD45, CD31, HIF-1α, iNOS, COX-2, and VEGF-A in tumor tissues. Additionally, a decrease in protein expression of VEGF-R2, VEGF-C, VEGF-R3, and LYVE-1 was noted in tumor tissues of licoricidin-treated mice. Furthermore, the blood concentrations of MMP-9, ICAM-1, VCAM-1, and VEGF-A were decreased in HEGU-treated mice. In vitro 4T1 cell culture results showed that both HEGU and licoricidin inhibited cell migration, MMP-9 secretion, and VCAM expression. The present study demonstrates that the licoricidin in HEGU inhibits lung metastasis of 4T1 mammary carcinoma cells, which may be mediated via inhibition of cancer cell migration, tumor angiogenesis, and lymphangiogenesis.

[Changes of six serum biomarkers of rabbits with experimental osteoarthritis]

OBJECTIVE

To investigate the value and significance of six serum biomarkers to the early diagnosis of osteoarthritis by means of quantitative detection of interleukin-1 beta (IL-1β), matrix metalloproteinase 13 (MMP-13), IL-6, C-terminal telopeptide of collagen type II (CTX2), cyclooxygenase 2 (COX2) and prostaglandin E2 (PGE2) levels with time going on.

METHODS

40 New Zealand white rabbits were divided into experimental group (n=20) and control group (n=20). Injection of collagenase into articular cavity was performed in the experimental group for modeling. No treatment was done in the control group. Pathological observation, X-ray examination and HE staining of knee joints were conducted to verify the establishment of modeling. IL-1, MMP-13, IL-6, CTX2, COX2 and PGE2 levels were detected every two weeks after modeling in the experimental group, and these biomarkers were also detected in the control group at the same time points.

RESULTS

Levels of the six serum biomarkers in the experimental group were significantly higher than those in the control group at each time point after modeling and were the most distinguishing at the 4th week.

CONCLUSION

Combined detection of IL-1β, IL-6, CTX2, COX2 and PGE2 in serum is helpful for early diagnosis of osteoarthritis.

Anti-inflammatory activity studies on the stems and roots of Jasminum lanceolarium Roxb

Jasminum lanceolarium Roxb is an important traditional Chinese medicine. Its stems and roots have been used for the treatment of rheumatism and fever while the leaves are used as an anti-inflammatory agent to relieve pain. In order to support its traditional Chinese medicinal uses, five animal models were designed and the anti-inflammatory and analgesic properties of the 70% EtOH-H2O extracts of J. lanceolarium (EJL) were investigated. Meanwhile, biochemical parameters such as cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) in blood serum of rats exposed to acute (carrageenan) inflammation model were evaluated. At doses of 400 mg/kg, EJL exhibited higher anti-inflammation effect than that of indomethacin and better analgesic activity than that of aspirin (P<0.001). Furthermore, eleven isolated compounds including six lignanoids (1, 2, 6, 7, 8, and 11) and five iridoids (3, 4, 5, 9, and 10) were isolated from the active extracts and showed significant anti-inflammatory activities with the IC50 values of 1.76-5.22 mg/mL, respectively, when testing their inhibitory effects on phospholipase A2 in vitro. The results demonstrated that the possible anti-inflammatory mechanisms might be attributed to inhibit the hydrolysis of membrane phospholipids, production on both COX-2 and 5-LOX, and then finally inhibit the release of prostaglandins (PGs), which suggested that EJL had a non-selective inhibitory effect on the release or actions of these mediators, and might be a dual LOX-COX inhibitor for the treatment of inflammation from the natural resource. The studies on the animals and the inflammatory mediators, along with the bioactive compounds presumed that the existences of iridoids and lignanoids could be response for their bioactivities of the whole plants.

Relationship between epidermal growth factor receptor (EGFR) mutation and serum cyclooxygenase-2 Level, and the synergistic effect of celecoxib and gefitinib on EGFR expression in non-small cell lung cancer cells

Epidermal growth factor receptor (EGFR) mutations occur mostly in patients with lung adenocarcinoma; such patients are also more likely to express cyclooxygenase-2 (COX-2), indicating a possible relationship between EGFR mutation and COX-2. The COX-2 and EGFR pathways mutually enhance their procarcinogenic effects in different tumor types. Therefore, simultaneous EGFR and COX-2 inhibition may be a promising therapeutic approach for patients with lung adenocarcinoma. We obtained tissue and serum samples from patients with non-small cell lung cancer (NSCLC) to detect the relationship between EGFR mutation and serum COX-2 level. Subsequently, gefitinib was combined with celecoxib to investigate the efficacy of inhibition in vitro in two NSCLC cell lines: HCC827 (del E746-A750) and A549 (wild-type EGFR). The cells were treated with gefitinib or celecoxib alone or with gefitinib plus celecoxib. Cell proliferation and apoptosis were assessed and correlated with expression of COX-2 and phosphorylated (p)-EGFR. The EGFR mutation rate of the high-COX-2 patients was significantly higher than that in the low-COX-2 patients. Multivariate analysis showed that high COX-2 levels were independently associated with EGFR mutation. Celecoxib and gefitinib inhibited cell growth in both cell lines. At sufficiently high concentrations, celecoxib plus gefitinib significantly mutually enhanced their anti-proliferative and apoptotic effects in both cell lines. At low concentrations, the combination had no additional effects on A549 cells. There was increased down regulation of COX-2 and p-EGFR when both cell lines were treated with high-concentration celecoxib plus gefitinib compared to either agent alone. This study demonstrates that high serum COX-2 levels may indicate EGFR mutations and that the efficacy of combined celecoxib and gefitinib is significantly greater in NSCLC cells with EGFR mutations; at high concentrations, the combination is efficacious in wild-type NSCLC cells.

Monitoring of cyclooxygenase-2 levels can predict EGFR mutations and the efficacy of EGFR-TKI in patients with lung adenocarcinoma

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation detection has become a routine molecular test with significant implications for prognosis and therapeutic options of EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, acquiring sufficient amounts of tissue for analyzing EGFR mutations is not often feasible, and not all the patients with sensitive EGFR mutations have benefit from EGFR-TKI treatment.

METHOD

EGFR mutations were detected by amplification refractory mutation system (ARMS) in 44 patients of newly diagnosed lung adenocarcinoma, and patients with EGFR-positive mutations received EGFR-TKI treatment. The serum cyclooxygenase-2 (COX-2) levels were tested before EGFR-TKI treatment and on the 30th days after EGFR-TKI treatment.

RESULTS

Twenty-nine cases were detected EGFR mutations. EGFR mutation rate of serum COX-2 high-level group was significantly higher than low-level group (92.9% vs. 53.3%, P=0.025). Multivariate analysis showed that serum COX-2 level was independently associated with EGFR mutation (P=0.033, OR=12.385, 95%CI, 1.231-124.567). Analysis of the correlation between clinical characteristics and the response of EGFR-TKI showed that the serum COX-2 high-level group had a better efficacy than low-level group (P=0.000), and multivariate logistic regression analysis showed that the serum COX-2 level was the independently influencing factor (P=0.004). Kaplan-Meier analysis showed that patients of COX-2 high-level group have longer progression-free survival (PFS, P=0.013), and the Cox regression analysis showed that the same result (P=0.003; OR=0.980, 95% CI, 0.967-0.993).

CONCLUSION

The serum COX-2 level seems to be closely associated with EGFR mutations in patients with Lung adenocarcinoma. The serum COX-2 level could help us to predict the responses of EGFR-TKI and the PFS in patients harboring EGFR mutation.

Relationship between expression of COX-2, TNF-α, IL-6 and autoimmune-type recurrent miscarriage

OBJECTIVE

To investigate the roles of COX-2, TNF-α, IL-6 in the pathogenesis of autoimmune-type recurrent spontaneous abortion (RSA).

METHODS

RT-PCR was used to detect the mRNA of COX-2, TNF-α, IL-6 in the trophoblast cells of murine RSA and normal pregnant models. The COX-2, TNF-α, IL-6 protein expressions were determined by using immunohistochemisry staining method. The COX-2, TNF-α, IL-6 protein expressions were determined by ELISA.

RESULTS

The embryo loss rates in experiment group was significantly higher than that in normal pregnancy control group, the expression of COX-2, TNF-α, IL-6 in the trophoblast cells of murine RSA and normal pregnant models. The expression of COX-2 in autoimmune-type recurrent spontaneous abortion was significantly lesser than in normal pregnant models. The expression of TNF-α, IL-6 in autoimmune-type recurrent spontaneous abortion was significantly higher than in normal pregnant models. There was a positively correlation between TNF-α and IL-6. There was no relationship between COX-2, TNF-α and IL-6.

CONCLUSIONS

The abnormal expression of COX-2, TNF-α and IL-6 may result in RSA.

Therapeutic effects of standardized Vitex negundo seeds extract on complete Freund's adjuvant induced arthritis in rats

The seeds of Vitex negundo L. (Verbenaceae) have been commonly used as a folk remedy for the treatment of rheumatism and joint inflammation in Traditional Chinese Medicine. This study aimed to evaluate the anti-arthritic activity of the extract of V. negundo seeds (EVNS) using Freund's complete adjuvant (CFA) induced arthritis (AA) in rat model. As a result, EVNS, with abundant phenylnaphthalene-type lignans, significantly inhibited the paw edema, decreased the arthritis score and spleen index, and reversed the weight loss of CFA-injected rats. Histopathological studies showed a marked decrease of synovial inflammatory infiltration and synovial lining hyperplasia in the joints of EVNS-treated animals. The remarkable decrement of serum inflammatory factors (TNF-α, IL-1β and IL-6) were observed in EVNS-treated rats, whereas, IL-10, an anti-inflammatory cytokine, was found to be significantly increased by EVNS. The expressions of COX-2 and 5-LOX in PBMC were also inhibited by administration of EVNS. Our results demonstrated that V. negundo seeds possessed potential therapeutic effect on adjuvant induced arthritis in rats by decreasing the levels of TNF-α, IL-1β and IL-6 and increasing that of IL-10 in serum as well as down-regulating the levels of COX-2 and 5-LOX, and therefore may be an effective cure for the treatment of human rheumatoid arthritis.

Decreased cyclooxygenase-2 gene expression and lactoferrin release in blood neutrophils of heifers during the calving period

Immunosuppression during the calving period in dairy cows is associated with an increased risk of diseases. Correct neutrophil function is a key mechanism of innate immunity that is used to protect the host from pathogenic microorganisms. The aim of this study was to evaluate the function of blood neutrophils obtained from heifers between 30 days preparturition and 30 days postparturition. We assessed the phagocytosis of fluorescent bioparticles using flow cytometry, chemotaxis induced by chemoattractants using the transwell plate assay, lactoferrin release using ELISA and cyclooxygenase-2 (COX-2) gene expression using real time-PCR. Our results showed an increased ability of phagocytosis of bioparticles and chemotaxis induced by the chemotactic agent platelet activating factor (PAF), between day 15 preparturition until day 30 postparturition, and at calving, respectively. COX-2 gene expression induced by PAF was increased only in neutrophils obtained at days 30 pre- and post-parturition (p<0.001). Neutrophil lactoferrin release was reduced between day 15 preparturition and day 30 postparturition compared with that at day 30 preparturition. Furthermore, lactoferrin plasma levels were increased at calving. In conclusion, we provided evidence that neutrophils from heifers around calving time exhibit impairment of particular defensive functions, such as COX-2 mRNA expression and lactoferrin, suggesting that these mechanisms may contribute to immunosuppression in cows around calving.

Changes chemopreventive markers in colorectal cancer development after inulin supplementation

BACKGROUND

Natural dietary compounds such as prebiotics modulate microbial composition and could prevent the colon cancer development as potential chemopreventive agent.

OBJECTIVES

Effect of prebiotic-inulin on biochemical, microbial and chemopreventive markers were examined in Sprague-Dawley rats during experimental chemically dimethylhydrazine induced colon cancer development.

METHODS

Rats were divided to 3 groups: control group (CG), group with dimethylhydrazine (DMH) and group with DMH and prebiotic (DMH+PRE). The efficacy of the prebiotic inulin (PRE) on the activities of β-glucuronidase, short chain fatty acids (SCFAs), counts of coliforms and lactobacilli, immunoreactivity of cyclooxygenase-2 (COX-2), transcription nuclear factor kappa beta (NFκB) and inducible nitric oxide synthase (iNOS) in colon tissue were examined.

RESULTS

Inulin significantly decreased coliforms counts (p<0.01), increased lactobacilli counts (p<0.001), and decreased activity of β-glucuronidase (p<0.01) in fresh caecal digesta. Butyric and propionic acids concentrations were increased after inulin supplementation in comparison to DMH group. Application of inulin decreased immunoreactivity and numbers of COX-2, NFκB and iNOS positive cells in colon tissue in comparison to DMH group.

CONCLUSION

Inulin suppressed expression observed markers, which play an important role in carcinogenesis and in the inflammatory process, which predisposes to the use of inulin in the prevention or treatment of inflammatory bowel disease (Tab. 1, Fig. 2, Ref. 17).

Anti-inflammatory and analgesic activity of total flavone of Cunninghamia lanceolata

The present study was undertaken to investigate the anti-inflammatory and analgesic activity of total flavone of branches and leaves of Cunninghamia lanceolata (TFC) to provide a scientific basis for its clinical use and resource development. TFC was evaluated for anti-inflammatory and analgesic activity in mice or rats using chemical and thermal models of nociception, including acetic acid-induced writhing test, hot plate latency test, formalin test and carrageenan induced paw oedema test. Results showed that TFC given orally can significantly attenuate acetic acid-induced writhing in mice in a dose-dependent manner. In the hot plate latency test, TFC showed common activity in prolonging duration time only at the highest dose (400 mg/kg). Each dose of TFC could not significantly inhibit the first phase but was active in the later phase of formalin-induced pain, whereas morphine showed notable activity in the two phases. In the carrageenan-induced paw oedema model, TFC could significantly and dose-dependently reduce the carrageenan-induced paw edema at the third and fifth hour, and decrease the content of PEG₂ in paw edema tissue and that of COX-2 in blood serum. It may be concluded that TFC showed both anti-inflammatory and analgesic effects, showing that it can be of importance in drug development, especially in the field of pain and inflammation.

Association of serum levels of polychlorinated biphenyls with IL-8 mRNA expression in blood samples from asthmatic and non-asthmatic Japanese children

BACKGROUND

One of the suggested health outcomes of PCB exposure is childhood asthma.

OBJECTIVES

This study was conducted to find health relevant biomarkers providing the molecular epidemiological evidence for the positive relationship between exposure to PCBs and childhood asthma.

METHODS

Blood samples from fifteen asthmatic children as well as an equal number of non-asthmatic children (average 2 year old) were collected, and were analyzed for PCBs and their select marker expression by using qRT-PCR.

RESULTS

Among biomarkers examined IL-8 expression was significantly correlated to serum levels of PCB #163+164 (P=0.022), #170 (P=0.046), #177 (P=0.022), #178 (P=0.022) and #180+193 (P=0.046) in a dose-dependent manner, which was found only among asthmatic children. In contrast, COX-2 correlations to individual congener levels were recognized only among control subjects, not among asthmatic subjects.

CONCLUSION

Serum concentrations of PCB#163+164, #170, #177, #178 and #180+193 correlate significantly with IL-8 mRNA expressions among asthmatic children.

[Expressions of CD4+ CD25(high) regulatory T cells, TGF-beta 1 and COX-2 in the peripheral blood of prostate cancer patients]

OBJECTIVE

To investigate the expressions of CD4+ CD25(high) regulatory T cells, TGF-beta 1 and COX-2 in the peripheral blood of prostate cancer (PCa) patients, and analyze the role of CD4+ CD25(high) regulatory T cells in the pathogenesis of PCa and their relationship with TGF-beta 1 and COX-2.

METHODS

We used flow cytometry to calculate the percentage of CD4+ CD25(high) regulatory T cells in the CD4+ T cells in the peripheral blood mononuclear cells (PBMC) from 30 PCa patients (11 localized and 19 non-localized cases) and 20 healthy volunteer controls, determined the expressions of TGF-beta 1 and COX-2 in the serum by ELISA, and analyzed their correlation with the CD4+ CD25(high) regulatory T cells in the PCa patients as well as the differences between the localized and non- localized cases.

RESULTS

CD4+ CD25(high) regulatory T cells accounted for (18.32 +/- 7.49) % in the CD4+ T cells in PBMCs from the PCa patients, significantly higher than (7.77 +/- 1.86) % from the controls (P < 0.05), but with no statistically significant difference between pre- and post-treatment in the PCa patients (P > 0.05). The expressions of TGF-beta 1 and COX-2 in the peripheral blood were (215.97 +/- 55.16) ng/ml and (6.88 +/- 5.14) ng/ml in the PCa patients, in comparison with (149.75 +/- 47.11) ng/ml (P < 0.05) and (6.88 +/- 5.14) ng/ml (P > 0.05) in the controls. Multiple linear regression analysis showed no significant correlation between the expression of CD4+ CD25(high) regulatory T cells in PBMCs and those of TGF-beta 1 and COX-2 in the peripheral blood of the PCa patients. There were no significant differences between the localized and non-localized PCa groups in the expressions of CD4+ CD25(high) regulatory T cells, TGF-beta 1 and COX-2 (P > 0.05).

CONCLUSION

CD4+ CD25(high) regulatory T cells in in PBMCs are involved in the pathogenesis of PCa. The proliferation of CD4+ CD25(high) regulatory T cells is not significantly correlated to the expressions of TGF-beta 1 and COX-2 in the peripheral blood, but maybe to the tumor itself and the local tumor microenvironment.

Spherical harmonics coefficients for ligand-based virtual screening of cyclooxygenase inhibitors

BACKGROUND

Molecular descriptors are essential for many applications in computational chemistry, such as ligand-based similarity searching. Spherical harmonics have previously been suggested as comprehensive descriptors of molecular structure and properties. We investigate a spherical harmonics descriptor for shape-based virtual screening.

METHODOLOGY/PRINCIPAL FINDINGS

We introduce and validate a partially rotation-invariant three-dimensional molecular shape descriptor based on the norm of spherical harmonics expansion coefficients. Using this molecular representation, we parameterize molecular surfaces, i.e., isosurfaces of spatial molecular property distributions. We validate the shape descriptor in a comprehensive retrospective virtual screening experiment. In a prospective study, we virtually screen a large compound library for cyclooxygenase inhibitors, using a self-organizing map as a pre-filter and the shape descriptor for candidate prioritization.

CONCLUSIONS/SIGNIFICANCE

12 compounds were tested in vitro for direct enzyme inhibition and in a whole blood assay. Active compounds containing a triazole scaffold were identified as direct cyclooxygenase-1 inhibitors. This outcome corroborates the usefulness of spherical harmonics for representation of molecular shape in virtual screening of large compound collections. The combination of pharmacophore and shape-based filtering of screening candidates proved to be a straightforward approach to finding novel bioactive chemotypes with minimal experimental effort.

[Synthesis and anti-inflammatory activities of methylhesperetin-7-alkyl ether analogues]

To investigate the relationship between the structures of methylhesperetin-7-alkyl ether analogues and their anti-inflammatory activities, nine new compounds, methyl-hesperetin (2), methylhesperetin-7-ethyl ether (3), 7-n-butyl ether (4), 7-n-hexyl ether (5), 7-n-octyl ether (6), 7-n-decyl ether (7), 7-n-dodecyl ether (8), 7-n-tetradecyl ether (9) and 7-n-hexadecyl ether (10), were synthesized with the lead compound of methylhesperidin (1). Their structures were confirmed by UV, 1H NMR, MS and HR-MS spectral data. The in vivo antiinflammatory activities of these compounds were tested on mouse paw edema induced by Freund's complete adjuvant (FCA) and mouse capillary permeability induced by acetic acid with po dose of 300 mg x kg(-1) x d(-1). The result indicated that the anti-inflammatory activities of the synthetic compounds increased firstly and then decreased with the elongating of the length of alkyl chain. After 25-day oral administration of compounds 6, 7 and 8, the inhibitory rates on mouse paw edema of adjuvant arthritis (AA) were 31.9%, 38.5%, 39.1%, respectively. They showed the concentrations of COX-2 in serum of AA mice respectively were 79.3, 75.4, 73.9 ng x L(-1) and the concentrations of PGE2 were in correspondence with 275.4, 258.9, 242.6 ng x L(-1). The inhibitory rates of compounds 6 and 7 on mouse capillary permeability induced by acetic acid were, respectively, 42.4% and 41.5% after 5-day oral administration. Compared with the lead compound of methylhesperidin, the anti-inflammatory activities of compounds 6, 7 and 8 were increased and showed an effective inhibition on the symptom of adjuvant arthritis and capillary permeability in mice.

[Relationship between cyclooxysenase 2 and serious hepatitis]

AIM

To study the cytokines regulated downstream effecter cyclooxygenase (COX-2's) function in the progression of serious hepatitis.

METHODS

Samples from 75 patients with hepatitis B virus (HBV)-associated serious liver disease with well-characterised clincal profiles and 30 HBV-infected patients were assessed by ELISA.

RESULTS

Compared with the general HBV-infected patients, serum TXB2 and 6-keto-PG1α level were uniformly elevated in all serious hepatitis patients (acute serious hepatitis patients vs general HBV-infected patients (P < 0.001); sub-acute serious hepatitis patients vs general HBV-infected patients (P < 0.01); chronic serious hepatitis patients vs general HBV-infected patients (P < 0.001). But there were no significant difference of these cytokines levels among the different types of serious hepatitis patients (P > 0.05).

CONCLUSION

In conclusion, product of COX-2 metabolism TXB2 and 6-keto-PGF1α were associated with the clinical progression of serious hepatitis; especially TXB2/6-keto-PGF1α ratio is an effective biological marker for prognosis and diagnosis for serious hepatitis.

The influence of Sam-Chil-Geun (Panax notoginseng) on the serum lipid levels and inflammations of rats with hyperlipidemia induced by poloxamer-407

PURPOSE

Atherosclerosis is characterized by the progressive deposition of lipids and inflammatory process. We attempted to develop a chemically-induced hyperlipidemic mice model, using poloxamer-407 and evaluated the lipid lowering and anti-inflammatory effect of P. notoginseng compared with that of atorvastatin, an antihyperlipidemic drug.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into 5 groups: control group without any intervention (normal), poloxamer 500 mg/kg i.p. (P), poloxamer plus atorvastatin 1.34 mg/kg p.o. (P + ST), poloxamer plus P. notogin-seng 40 mg/kg p.o. (P + NG40), and poloxamer plus P. notoginseng 100 mg/kg p.o. (P + NG100). After 3 weeks, we measured serum total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride, interleukin (IL)-1, tumor necrosis factor (TNF)-alpha levels, and reports of cyclo-oxygenase (COX)-2 and intercellular adhesion molecule (ICAM) appearances in each group.

RESULTS

After 3 weeks, serum cholesterol levels significantly decreased in P + ST and P + NG40 groups. Significant decrease of LDL level was only noted in the P + ST group. P + ST, P + NG40, and P + NG100 also had decreased serum triglyceride levels; however, P + ST and P + NG40 showed no statistical difference of the triglyceride lowering effect. The results of IL-1 and TNF-alpha and the appearance of COX-2 and ICAM were statistically not different in each group.

CONCLUSION

P. notoginseng 40 mg/kg showed significantly lowering effects on serum total cholesterol and triglyceride levels. We suggest a well-designed study showing the effects of regulating blood lipids with combined administration of P. notoginseng and statin-drug.

Celecoxib combined with atorvastatin prevents progression of atherosclerosis

BACKGROUND

Increased expression of cyclooxygenase (COX-2) contributes to atherosclerosis. Recent studies suggest that COX-2 inhibitors prevent early plaque development but their effects on established lesions are less clear, while the statins promote plaque stability. The purpose of this study is to investigate whether administering a combination of a COX-2 inhibitor with a statin drug alters plaque progression in apo E-/- mice.

MATERIALS AND METHODS

Apo E-/- mice were fed a Western diet from 6 to 26 wk of age. At 26 wk, the Western diets supplemented with atorvastatin, celecoxib, or atorvastatin plus celecoxib were given for an additional 12 wk.

RESULTS

When the mice were 38 wk of age, the total area occupied by the atherosclerotic lesion was 53% less in the mice fed the combination of atorvastatin + celecoxib P ≤ 0.05) than that of the apo E-/- mice fed the Western diet alone, atorvastatin alone, or celecoxib alone. The decreased extent of atherosclerosis observed in the apo E-/- mice fed the combination of drugs was associated with reduced levels of prostaglandin (PG) E(2,) decreased protein expression of metalloproteinase (MMP)-9, macrophage chemotactic protein (MCP-1), and COX 2, and decreased staining for MMP-9, F4-80 (a marker for macrophages), and vascular cell adhesion molecule (VCAM).

CONCLUSION

This study indicates that using statins with a COX-2 inhibitor reduced the extent of atherosclerosis and inflammatory/cell adhesion molecule levels in the apo E-/- mouse model.

Endogenous gonadal hormones regulate females' behavioral responses to formalin through prostaglandin E2 release

INTRODUCTION

This study aimed to determine if endogenous gonadal hormones affect the intracellular mechanisms in the spinal cord that control inflammatory pain responses.

METHODS

We analyzed behavioral responses to, and changes in, serum levels of prostaglandin E2, estradiol, progesterone, and corticosterone after administration of 5% formalin in intact and ovariectomized (OVX) female rats.

RESULTS

OVX females displayed significantly more flinching than did intact females during Phase I, and after formalin administration their corticosterone levels were significantly lower. No differences were seen across COX-1 and COX-2 protein expression in the spinal cord of either naive or formalin-treated rats. However, subsequent to formalin a main effect of gonadectomy was seen in prostaglandin E2 levels; OVX animals had significantly lower prostaglandin E2 levels than intact animals.

CONCLUSIONS

These results indicate that in female rats nociceptive responses to formalin are regulated through the levels of prostaglandin E2, an important mediator in inflammation, whereas protein levels of COX-1 and COX-2 play a more limited role.

Different methods for testing potential cyclooxygenase-1 and cyclooxygenase-2 inhibitors

The need for the development of selective agents, which only inhibit the mainly "harmful" cyclooxygenase-2 (COX-2) while leaving physiological COX-1 mostly unaffected, still remains, especially after the recent issues related to cardiovascular toxicity caused by some COX-2 selective agents. Thus there is still a demand for sensitive and rapid methods to assay for COX-2 selective agents. Among several in vitro testing systems the whole blood assay (WBA) is a well-known method to examine non-steroidal anti-inflammatory drugs (NSAIDs) in view of their potency to inhibit COX activity. This assay has some major advantages over enzyme-based or isolated cell assays. Emergence of artifacts due to cell separation steps is kept to a minimum and substances, even in disproportional high concentrations, can be examined outside the body in a physiological environment resembling most closely the in vivo conditions in living humans, i.e., 37 degrees C, homeostasis, presence of all blood compounds and cell-cell interactions remain intact. While COX-1 human whole blood assays are performed within less than 2 h, for established COX-2 assays one still has to allow for an overnight incubation step before gaining the desired plasma. The aim of the assay described in this chapter is to characterize an optimized human whole blood assay (hWBA). We present a simple, fast and reliable method to examine the capacity of NSAIDs at inhibiting COX-2 activity that can be applied for rapid and routine screening purposes.

Improved antioxidant and anti-inflammatory potential in mice consuming sour cherry juice (Prunus Cerasus cv. Maraska)

The present investigation tested the in vivo antioxidant efficacy (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase; Gpx), lipid peroxidation (LPO) and anti-inflammatory properties (cyclooxygenase-2; COX-2) of sour cherry juices obtained from an autochthonous cultivar (Prunus cerasus cv. Maraska) that is grown in coastal parts of Croatia. Antioxidant potential was tested in mouse tissue (blood, liver, and brain), LPO (liver, brain) and anti-inflammatory properties in glycogen elicited macrophages. Additionally, the concentration of cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-glucoside, pelargonidin-3-rutinoside and total anthocyanins present in Prunus cerasus cv. Maraska cherry juice was determined. Mice were randomly divided into a control group (fed with commercial food pellets) and 2 experimental groups (fed with commercial food pellets with 10% or 50% of cherry juice added). Among the anthocyanins, the cyanidin-3-glucoside was present in the highest concentration. These results show antioxidant action of cherry juice through increased SOD (liver, blood) and Gpx (liver) activity and decreased LPO concentration. The study highlights cherry juice as a potent COX-2 inhibitor and antioxidant in the liver and blood of mice, but not in the brain. Thus, according to our study, Prunus cerasus cv. Maraska cherry juice might potentially be used as an antioxidant and anti-inflammatory product with beneficial health-promoting properties.

Analgesic and anti-inflammatory activities of ethanol root extract of Mahonia oiwakensis in mice

AIMS OF THE STUDY

This study investigated the anti-inflammatory and analgesic activities, and protoberberine alkaloid contents of ethanol extract of MO roots (MOR(EtOH)).

MATERIALS AND METHODS

The analgesic activity of MOR(EtOH) was determined using acetic acid-induced writhing response and formalin test. The anti-inflammatory activity of MOR(EtOH) was determined using the lambda-carrageenan-induced paw oedema model. The protoberberine alkaloid contents of MOR(EtOH) were identified by high-performance liquid chromatography (HPLC).

RESULTS

MOR(EtOH) (100 and 500 mg/kg) decreased the acetic acid-induced writhing responses and licking times of the second phase in the formalin test. Moreover, carrageenan-induced paw oedema was significantly reduced in a dose-dependent manner by administering MOR(EtOH) (100 and 500 mg/kg) at 3, 4, and 5h after the carrageenan injection. The serum levels of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) of MOR(EtOH)-treated mice were significantly reduced compared with those in the serum of animals administered carrageenan. Notably, MOR(EtOH) attenuated the expression of cyclo-oxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) and neutrophil infiltration in paw tissues injected with carrageenan. The anti-inflammatory mechanisms of MOR(EtOH) appear to be related to the inhibition of neutrophil infiltration, iNOS and COX-2 protein expression, NO release, and the decreasing TNF-alpha level in serum. The analytical results showed that the contents of berberine, palmatine and jatrorrhizine were 191.45 mg/g extract, 100.15 mg/g extract and 66.45 mg/g extract, respectively.

CONCLUSION

These experimental results suggest that MOR(EtOH) produced both analgesic and anti-inflammatory effects in mice and may be a candidate for the development of pharmacological agents used in the treatment of inflammatory disorders.

Possible role of cyclooxygenase-2 in developing chronic subdural hematoma

Inflammatory cytokines are reportedly involved in the pathogenesis of chronic subdural hematomas (CSH), and the angiogenesis of hematomas has particularly been in focus. Cyclooxygenase-2 (COX-2) is an essential enzyme for the synthesis of prostaglandin E2 (PGE2). The COX-2-PGE2 pathway has been shown to influence angiogenic factors such as vascular endothelial growth factor (VEGF). We investigated the association of COX-2 expression in the dura mater and outer membrane with the pathogenesis of CSH, and suggested a treatment strategy on the basis of this association. Hematoma fluid and serum samples obtained from 37 patients, and samples of the dura mater and outer CSH membrane obtained from 13 patients during the operation were examined in this study. The concentrations of PGE2 in relation to COX-2 in the hematoma fluid were significantly higher than those in the serum. Immunohistochemical analyses revealed COX-2-positive cells in the outer membrane of CSHs. There was a linear and significant relationship between PGE2 concentration in hematoma fluid and the interval from trauma to initial surgery. COX-2 may play a crucial role during the development of CSHs. Our study might lead to the development of anti-COX-2 treatment options that aim to minimize repeat surgery and choose medical therapy by reducing CSH morbidity and recurrence rate in patients with CSH.

C-reactive protein and malignancy: clinico-pathological association and therapeutic implication

C-reactive protein (CRP) is a widely used systemic biomarker for diagnosing acute and chronic inflammation. During the past decade, serum CRP has been re-emphasized by extending its clinical use to the prediction or diagnosis of cardiovascular diseases and other conditions, particularly malignancies. Serum CRP has also been found to be elevated in patients with many malignancies, implying a close linkage between inflammation and malignancy. Prospective studies have shown a higher risk of developing cancer in those with elevated serum CRP. CRP is produced by hepatocytes in response to inflammatory cytokines, particularly, interleukin-6 from the tumor microenvironment. Preoperative CRP levels are parallel to the progression or pathological stages of malignancies, including gastric cancer in patients in our series. Elevated CRP is a determinant predictor of lower survival rates in patients with several cancers, including esophageal, colorectal, hepatocellular, pancreatic, urinary bladder, renal,ovarian and cervical cancer, after surgical resection. The measurement of serum CRP is simple, cheap, and available in daily practice. It can serve as an additional prognostic predictor for survival and post-treatment monitoring in cancer patients. In the future, CRP-lowering agents might offer a promising benefit in the prevention and therapy of many different types of cancer.

Soymilk supplementation does not alter plasma markers of inflammation and oxidative stress in postmenopausal women

Aging is associated with increasing levels of systemic inflammation and oxidative stress, both of which contribute to the progression of cardiovascular disease. Attenuation of such processes via dietary intervention has significant public health implications. Soyfoods, as a source of high-quality protein and isoflavones, may improve such indices, although such effects in healthy aging women are not well delineated. The purpose of this study was to test the hypothesis that 4 weeks of daily soymilk consumption would improve systemic markers of inflammation and oxidative stress in postmenopausal women when compared with a dairy control. In September 2009, a single-blind, randomized, controlled trial was conducted on 31 postmenopausal women at Baylor University, Waco, Tex. Subjects were randomly assigned to consume 3 servings of vanilla soy (n = 16) or reduced fat dairy (n = 15) milk per day for 4 weeks. Plasma markers of inflammation (tumor necrosis factor alpha [TNF-alpha], interleukin [IL]-1beta, IL-6) and oxidative stress (superoxide dismutase [SOD], glutathione peroxidase [GPx], cyclooxygenase-2 [COX-2]) were obtained before and after supplementation. No significant differences were observed for any of the plasma inflammatory (TNF-alpha, P = .08; IL-1beta, P = .14; IL-6, P = .26) or oxidative stress (SOD, P = .68; GPx, P = .58; COX-2, P = .99) variables by dietary treatment group. Despite good dietary compliance, our study failed to show a significant effect of soymilk consumption on markers of inflammation and oxidative stress in this postmenopausal female population. Potential reasons for this nonsignificant finding are discussed, and future research directions are presented.

[Expressions of vascular endothelial growth factor and cyclooxygenase-2 in patients with multiple myeloma and its significance]

This study was aimed to investigate the expressions of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) in patients with multiple myeloma (MM) and its clinical significance. Expression of VEGF was detected by enzyme linked immunosorbent assay (ELISA) and the level of COX-2 was detected by Western blot. The results showed that the serum VEGF level of multiple myeloma patients (365.34 +/- 65.63 pg/ml) was higher than that in the normal persons (122.52 +/- 39.29 pg/ml) (p < 0.05); the serum VEGF level of patients at advanced stage (395.07 +/- 54.90) pg/ml was higher than those at stable stage (300.33 +/- 44.22) pg/ml (p < 0.05). The serum Cox-2 positive rate in the patients (31%) was higher than that in normal persons (0%) (p < 0.01); the serum Cox-2 positive rate in the patients at advanced stage (50%) was higher than those at stable stage (21%) (p < 0.01). It is concluded that VEGF and COX-2 may play an important role in the pathogenesis and development of multiple myeloma, they can be used to evaluate the status of patients with MM.

Synthesis, characterization and preliminary screening of regioisomeric 1-(3-pyridazinyl)-3-arylpyrazole and 1-(3-pyridazinyl)-5-arylpyrazole derivatives towards cyclooxygenase inhibition

In a search for novel compounds with analgesic and anti-inflammatory activity, a series of regioisomeric 1-(3-pyridazinyl)-3-arylpyrazole (5a-f, 6a-f) and 1-(3-pyridazinyl)-5-arylpyrazole (7a-f, 8a-f) derivatives were synthesized. The structure of these regioisomers was confirmed by spectral techniques. The compounds were preliminarily screened at 8 microM concentration for their inhibitory activity against cyclooxygenase enzymes, COX-1 and COX-2, using a human whole blood test. The tested derivatives showed inhibitory activity for both enzymes and are worthy of further investigation for developing better leads.

Blood COX-2 and PGES gene transcription during the peripartum period of dairy cows with normal puerperium or with uterine infection

In the dairy cow, puerperal uterine intra-luminal concentrations of PGE(2) are related to the establishment and severity of uterine infections. Here we evaluated whether the blood concentrations of PGE(2) and the gene transcription profiles of enzymes involved in its synthesis (cyclooxygenase-2 and prostaglandin E synthase) could be used as markers of predisposition and/or presence of puerperal uterine infections. We also studied the relationship between the endocrine status and the leukocyte profiles around parturition and the transcription patterns of the genes. Finally, we have characterized the in vitro gene transcription and expression response to a challenge of LPS. Gene transcription profiles, quantified by real-time PCR, were similar in normal puerperium and metritis/endometritis cows, indicating that they are not suitable markers of predisposition to/presence of puerperal uterine infections. Transcription decreased from 2 weeks before parturition until parturition, when a minimum was attained, and then increased during the first week postpartum. The lowest gene transcription, at parturition, was coincidental with the highest total leukocytes, polymorphonuclear neutrophils and CD14 positive cell numbers. It is suggested that by this mechanism, a large number of PMN can be recruited into the uterus after parturition, avoiding an excessive acute inflammatory response. The lowest gene transcription was also coincidental with the surge in cortisol concentrations, indicating that this hormone plays a main immunomodulatory role around parturition. Gene transcription was significantly greater after stimulation with LPS than in non-stimulated blood. We suggest that this PGE(2) producing cells might arrive to the uterine lumen, contributing to the local PGE(2) concentrations and mediating the inflammatory response.

Nucleobindin co-localizes and associates with cyclooxygenase (COX)-2 in human neutrophils

The inducible cyclooxygenase isoform (COX-2) is associated with inflammation, tumorigenesis, as well as with physiological events. Despite efforts deployed in order to understand the biology of this multi-faceted enzyme, much remains to be understood. Nucleobindin (Nuc), a ubiquitous Ca²⁺-binding protein, possesses a putative COX-binding domain. In this study, we investigated its expression and subcellular localization in human neutrophils, its affinity for COX-2 as well as its possible impact on PGE₂ biosynthesis. Complementary subcellular localization approaches including nitrogen cavitation coupled to Percoll fractionation, immunofluorescence, confocal and electron microscopy collectively placed Nuc, COX-2, and all of the main enzymes involved in prostanoid synthesis, in the Golgi apparatus and endoplasmic reticulum of human neutrophils. Immunoprecipitation experiments indicated a high affinity between Nuc and COX-2. Addition of human recombinant (hr) Nuc to purified hrCOX-2 dose-dependently caused an increase in PGE₂ biosynthesis in response to arachidonic acid. Co-incubation of Nuc with COX-2-expressing neutrophil lysates also increased their capacity to produce PGE₂. Moreover, neutrophil transfection with hrNuc specifically enhanced PGE₂ biosynthesis. Together, these results identify a COX-2-associated protein which may have an impact in prostanoid biosynthesis.

Neuroinflammation in the pathophysiology of Parkinson's disease: evidence from animal models to human in vivo studies with [11C]-PK11195 PET

Increasing evidence suggests that neuroinflammation is an active process in Parkinson's disease (PD) that contributes to ongoing neurodegeneration. PD brains and experimental PD models show elevated cytokine levels and up-regulation of inflammatory-associated factors as cyclo-oxygenase-2 and inducible nitric oxide oxidase. Antiinflammatory treatment reduced neuronal degeneration in experimental models. In this review, we summarize the place of neuroinflammation in the pathophysiology of PD. In vivo PET studies are discussed. These methods provide a means to monitor in vivo potential clinical relevance of antiinflammatory treatment strategies in PD.

Platelet responsiveness to in vitro aspirin is independent of COX-1 and COX-2 protein levels and polymorphisms

Aspirin's inhibitory effect on platelet function has been shown to be highly heterogeneous. However, due to the considerable individual variation in pharmacokinetics after aspirin intake, it has been difficult to investigate the mechanism of aspirin resistance empirically. Our objective was to examine whether platelet responsiveness to in vitro aspirin treatment could be affected by cyclooxygenase (COX)-1/2 protein levels in platelets or single-nucleotide polymorphisms (SNPs), which could possibly change specific activity of enzymes and/or aspirin susceptibility. Collagen/epinephrine closure time (CEPI-CT) of PFA-100 in blood from 178 healthy males was assessed with/without aspirin. Platelet COX-1 protein levels and the sequences of COX-1 gene exons were examined in three groups categorized by CEPI-CT: PR (Poor responders to aspirin), 10 people showing the shortest CEPI-CT under aspirin; GR-High or GR-Low (good responders to aspirin with high or low platelet basal reactivity), 10 people showing CEPI-CT over 300 s under aspirin and having the shortest or longest basal CEPI-CT, respectively. We analyzed the three groups, representing phenotypic extremes, aiming to increase statistical power to investigate the possible relevance of COXs to platelet response to aspirin. Western blot analysis revealed that COX-1 was abundantly expressed in platelets at comparable levels among the three groups, whereas COX-2 was undetectable. The frequencies of nonsynonymous COX-1/2 SNPs were unlikely to explain the difference in aspirin responsiveness considering the observed genotype frequencies and wide individual variation in platelet response. These results suggest that heterogeneity in platelet responsiveness to in vitro aspirin is independent of COX-1/2 protein levels and SNPs.

Effects of selective COX-2 inhibition on prostanoids and platelet physiology in young healthy volunteers

BACKGROUND

Selective inhibitors of cyclooxygenase-2 (COX-2) called coxibs, are effective anti-inflammatory and analgesic drugs. Recently, these drugs were associated with an increased risk for myocardial infarction and atherothrombotic events. The hypothesis of thromboxane-prostacyclin imbalance has been preferred to explain these unwanted effects.

METHODS

We studied the effects of 14 days intake of rofecoxib (25 mg q.d.), celecoxib (200 mg b.i.d.), naproxen (500 mg b.i.d.) and placebo in a randomized, blinded, placebo-controlled study in young healthy volunteers (median age 25-30 years, each group n = 10). We assessed prostanoid metabolite excretion (PGE-M, TXB(2), 6-keto-PGF(1alpha), 11-dehydro-TXB(2), 2,3-dinor-TXB(2), and dinor-6-keto-PGF(1alpha)), the expression of platelet activation markers (CD62P, PAC-1, fibrinogen), platelet-leukocyte formation, the endogenous thrombin potential, platelet cAMP content and plasma thrombomodulin level.

RESULTS

Naproxen suppressed biosynthesis of PGE-M, prostacyclin metabolites and thromboxane metabolites and thrombomodulin levels. In contrast, both coxibs had an inhibitory effect only on PGE-M, 6-keto-PGF(1alpha), and on dinor-6-keto-PGF(1alpha), whereas TXB(2), 2,3-dinor-TXB(2) and 11-dehydro-TXB(2) excretion were unaffected. None of the coxibs exerted significant effects on the expression of platelet activation markers, cAMP generation, platelet-leukocyte formation, or on thrombomodulin plasma levels. Interestingly, platelet TXB(2) release during aggregation was enhanced after coxib treatment following arachidonic acid or collagen stimulation.

CONCLUSION

In young healthy volunteers coxibs inhibit systemic PGE(2) and PGI(2) synthesis. Platelet function and expression of platelet aggregation markers are not affected; however, coxibs can stimulate TXB(2) release from activated platelets. Combined decrease in vasodilatory PGE(2) and PGI(2) together with increased TXA(2) in proaggregatory conditions may contribute to coxib side effects.