Cyclooxygenase Enzyme Activity Research Articles

Assessment of cell death in the liver of Labeo rohita on exposure to an emerging contaminant aspirin: an immunofluorescent, flow cytometric and biochemical investigation.

Aspirin is one of the most frequently detected non-steroidal anti-inflammatory drugs in aquatic environments. Despite its prevalence, toxicity possessed by aspirin to non-target organisms like fish is poorly explored. In the present study, cell death induced by different concentrations of aspirin (1, 10, and 100µg/L) has been investigated in the liver of fish, Labeo rohita exposed for 28days. A significant increase (p < 0.05) in the density of caspase-3 positive cells in a dose and duration-dependent manner assessed through immunofluorescent staining indicates caspase-dependent pathway of cell death which may be either through intrinsic or extrinsic pathway. The flow cytometric analysis, in addition, revealed a significant (p < 0.05) decline in the live cells and an increase in apoptotic cells in the liver of fish exposed to aspirin. Cell death due to apoptosis is further indicated by a significant increase (p < 0.05) in the Kupffer cells and tumor necrosis factor-α. The decrease in the activity of cyclooxygenase (COX) enzyme significantly (p < 0.05) in all three exposure concentrations of aspirin suggests COX-dependent pathway of cell death. The present study provides in-depth insights into aspirin-induced cell death in the liver of fish at environmentally realistic concentrations.

Screening bioactive compounds from Fangji Huangqi decoction for treating rheumatoid arthritis via COX-2 magnetic ligand fishing combined with in vivo validation

Ethnopharmacological relevanceFangji Huangqi Decoction (FHD) is a classical Chinese compound formula for treating rheumatoid arthritis (RA) with satisfactory effects. FHD is reputed for its ability to tonify qi with strengthening exterior, and dispel wind while removing dampness, but its mechanisms and bioactive compounds for treating RA remain unclear. Aim of the studyThe aim of this study was to explore the key target and bioactive compounds that were responsible for FHD-mediated improvements in RA. Materials and methodsUsing network pharmacology, we discovered that cyclooxygenase-2 (COX-2) was the key target of FHD against RA. We utilized a ligand fishing technique with COX-2 immobilized magnetic beads to recognize the bioactive components that act on COX-2. Then we carried out an in vitro assay of COX-2 enzyme inhibition and in vivo assay of carrageenan-induced inflammation and collagen-induced arthritis (CIA) to validate the bioactive effects of these captured ingredients. In the CIA assay, micro-CT, hematoxylin‒eosin staining and safranin-O/fast green staining were employed to assess the influence of the captured ligand on bone damage, pathological injury and cartilage destruction, respectively. Immunohistochemistry (IHC) and enzyme-linked immunosorbent assays (ELISAs) were used to detect the expression of COX-2 target in the ankle joint. interleukin-6 (IL-6) levels in the serum were also detected by ELISA. Molecular docking was used to reveal the binding mechanism of the COX-2 protein and the captured ligand. ResultsEleven ligands, including tetrandrine, fangchinoline, cyclanoline, licochalcone B, ononin, calycosin and liquiritin, were specifically bound to the COX-2 protein, as determined by ultrahigh-performance liquid chromatography–mass spectrometry (UPLC–MS), seven of which were present at high levels. One ligand, tetrandrine, not only had a great inhibitory effect on COX-2 enzyme activity but also significantly reduced carrageenan-induced inflammation. In the CIA assay, middle- and high-dose tetrandrine (25 and 50 mg/kg) had effects comparable to those of FHD and celecoxib on ameliorating RA symptoms in CIA mice via the COX-2 target. Furthermore, compared with the low-dose tetrandrine group (12.5 mg/kg), the FHD group exhibited significantly lower arthritis index scores and serum IL-6 expression, although the content of tetrandrine in FHD extract solution was approximately 0.1% of that in the low-dose tetrandrine group. ConclusionsHence, we inferred that tetrandrine was the main bioactive component responsible for the effects of FHD against RA by suppressing the expression of the COX-2 protein and inhibiting the enzyme catalytic activity of COX-2. The reason for these effects may be that tetrandrine can interact with the residue Tyr385 of COX-2, the enzymatic catalytic site of COX-2 to transform arachidonic acid (AA) to prostaglandin E2 (PGE2), and thereby reduce the production of prostaglandins and inflammatory metabolites. Moreover, in addition to tetrandrine, FHD contains other compounds that could supplement the activity of tetrandrine when FHD was used to treat RA, which is manifested the “multi-component” characteristic of how Traditional Chinese Medicine formulas treat diseases.

Nutraceutical formulation based on a synergic combination of melatonin and palmitoylethanolamide for the management of allergic events.

The management of allergic events is a growing global health issue, especially in industrialized countries. This disease is an immune-mediated process, regulated by the interaction of IgE with an allergen, resulting in mast cell activation, which concerns the release of several immune-inflammatory modulators, i.e., histamine, β-hexosaminidase, COX-2, IL-6, and TNF-α, responsible for the main allergic-reaction associated symptoms. The aim of the present study was the efficacy evaluation of an alternative remedy, an innovative nutraceutical formulation (NF) based on the synergic combination of melatonin (MEL) and palmitoylethanolamide (PEA) for the prevention and treatment of immune disease. At first, the intestinal bioaccessibility of PEA and MEL in NF was assessed at 1.6 and 36%, respectively. Then the MEL and PEA ability to modulate the release of immune-inflammatory modulators in the human mast cell line (HMC-1.2) at their bioaccessible concentration was investigated. Our results underline that NF treatment was able to reduce COX-2 mRNA transcription levels (-30% vs. STIM, p < 0.0001) in stimulated HMC-1.2 and to contract COX-2 enzymatic activity directly (IC50: 152 μg/mL). Additionally, NF showed valuable ability in reducing histamine and β-hexosaminidase release in stimulated HMC-1.2, as well as in decreasing TNF-α and IL-6 mRNA transcription levels and protein production.

Interaction of endocannabinoid system and cyclooxygenase metabolites with fatty acid amide hydrolase and cyclooxygenase enzyme activities on contractile responses in rat vas deferens tissue.

The endocannabinoid system and prostaglandins are important modulators in the genitourinary system. This study aimed to investigate the possible interactions between the endocannabinoid system and the cyclooxygenase (COX) pathway on rat vas deferens. For this purpose, the concentration responses of the endocannabinoid anandamide, prostaglandin F2α analog latanoprost, and prostaglandin E1 analog misoprostol on the electrical field stimulation (EFS)-induced contractile responses were obtained. The concentration responses to anandamide were obtained again in the presence of nonselective COX inhibitor flurbiprofen and prostaglandin analogs, while the concentration responses of latanoprost and misoprostol were obtained in the presence of cannabinoid receptor antagonists and fatty acid amide hydrolase (FAAH) enzyme inhibitor URB597. FAAH, COX-1, and COX-2 enzyme levels in vas deferens tissue samples were also determined. The cumulative addition of anandamide was not different from the vehicle; however, the EFS-induced contractile responses were significantly increased with the incubation of latanoprost or flurbiprofen in the prostatic portion. Flurbiprofen and misoprostol decreased FAAH enzyme levels in both portions of the vas deferens, while latanoprost induced the inhibition in the prostatic portion. The cumulative administration of latanoprost and misoprostol significantly enhanced the contractile responses in the prostatic portion. This effect of latanoprost was significantly antagonized by URB597 and AM251. The enhancing effect of misoprostol was antagonized by anandamide, URB597, AM251, and AM630. Anandamide, AM251, AM630, and URB597 decreased enzyme levels of COX-1 and COX-2 in both portions of the vas deferens. These results demonstrate an intricate crosstalk between endocannabinoids and prostaglandins in modulation of the vas deferens contractility.

Activities of sondhep herbs to cause changes in IL-1β in an osteoarthritis rat model

Background: Osteoarthritis (OA) is a slowly progressive and degenerative joint disease. Symptoms of pain and inflammation are influenced by IL-1β, which increases COX-2 enzyme activity and PGE2 production. Sumenep Sondhep herbs are used by the community for joint pain. Objective: To evaluate the activities of the Sumenep Sondhep herb in reducing the cytokine IL-1β in the OA rats model. Methods: Monosodium iodoacetate (MIA) induction was carried out on animal OA models. Rats were treated with Sondhep extract for 28 days. Knee diameter and hyperalgesia responses were recorded every week until the 7th week. The IL-1β levels were observed on the 21st and 49th days using the ELISA method. Results: There was a significant difference in decreasing the diameter of the rat's knee (p &lt; 0.05), increasing the hyperalgesia test in the rats (p &lt; 0.05), and decreasing IL-1β levels between before and after treatment (p &lt; 0.05). Conclusion: The Sondhep Sumenep herb has activity against osteoarthritis by reducing pro-inflammatory cytokine IL-1β in OA rat models.

Evaluation of the in vitro anti-inflammatory and anti-Helicobacter pylori activities of chitosan-based biomaterials modified with copper oxide nanoparticles

For chemical modification, p-aminobenzoic acid was incorporated into chitosan Schiff base (ACsSB) and chitosan (ACs). Two ACs-based CuO nanoparticles composites; ACs/CuONPs-1 % and ACs/CuONPs-5 %, were also synthesized. Their structures were emphasized utilizing several analytical techniques; elemental analysis, FTIR, 1H NMR, XRD, SEM, EDX and TEM. Compared with standard cyclooxygenase (COX) inhibitor, Celecoxib, the prepared biomaterials showed in vitro selective inhibitory effectiveness against COX-2 enzyme that could be sorted, according to their MIC values that produce 50 % inhibition of COX-2 enzyme activity, as follows: Celecoxib (0.28 μg/mL) > ACs/CuONPs-5 % (4.1 μg/mL) > ACs/CuONPs-1 % (14.8 μg/mL) > ACs (38.5 μg/mL) > ACsSB (58.9 μg/mL) > chitosan (>125 μg/mL). Further, ACs/CuONPs-5 % has more in vitro inhibition efficiency towards Helicobacter pylori (H. pylori) than the other prepared biomaterials. Interestingly, the MIC value of 100 % growth inhibition of H. pylori for ACs/CuONP-5 % is equal to that of drug Clarithromycin (1.95 μg/mL). Thus, ACs/CuONPs-5 % has a promising potential as anti-H. pylori and selective anti-inflammatory agent. ACs/CuONPs-5 % is safe on the human gastric normal cells (GES-1). Therefore, amalgamation of both p-aminobenzoic acid and CuONPs into chitosan extremely promoted its anti-inflammatory and anti-H. pylori activity. This is a promising approach to achieve methods successful to compete the conventional antibiotics.

High molecular weight hyaluronic acid drastically reduces chemotherapy-induced mucositis and apoptotic cell death

Oral and intestinal mucositis (OIM) are debilitating inflammatory diseases initiated by oxidative stress, resulting in epithelial cell death and are frequently observed in cancer patients undergoing chemo-radiotherapy. There are currently few preventative strategies for this debilitating condition. Therefore, the development of a safe and effective mucositis mitigating strategy is an unmet medical need. Hyaluronic acid (HA) preparations have been tentatively used in oral mucositis. However, the protective effects of HA in chemotherapy-induced mucositis and their underlying mechanisms remain to be fully elucidated. This study aimed to assess these mechanisms using multiple formulations of enriched HA (Mucosamin®), cross-linked (xl-), and non-crosslinked high molecular weight HA (H-MW-HA) in an oxidative stress-induced model of human oral mucosal injury in vitro and an in vivo murine model of 5-flurouracil (5-FU)-induced oral/intestinal mucositis. All tested HA formulations protected against oxidative stress-induced damage in vitro without inducing cytotoxicity, with H-MW-HA also significantly reducing ROS production. Daily supplementation with H-MW-HA in vivo drastically reduced the severity of 5-FU-induced OIM, prevented apoptotic damage and reduced COX-2 enzyme activity in both the oral and intestinal epithelium. In 5-FU-injected mice, HA supplementation also significantly reduced serum levels of IL-6 and the chemokine CXCL1/KC, while the serum antioxidant activity of superoxide dismutase was elevated. Our data suggest that H-MW-HA attenuates 5-FU-induced OIM, at least partly, by impeding apoptosis, inhibiting of oxidative stress and suppressing inflammatory cytokines. This study supports the development of H-MW-HA preparations for preventing OIM in patients receiving chemotherapy.

Systemic Review of Clot Retraction Modulators.

Through a process termed clot retraction, platelets cause thrombi to shrink and become more stable. After platelets are activated via inside-out signaling, glycoprotein αIIbβIII binds to fibrinogen and initiates a cascade of intracellular signaling that ends in actin remodeling, which causes the platelet to change its shape. Clot retraction is also important for wound healing. Although the detailed molecular biology of clot retraction is only partially understood, various substances and physiological conditions modulate clot retraction. In this review, we describe some of the current literature pertaining to clot retraction modulators. In addition, we discuss compounds from Cudrania trucuspidata, Arctium lappa, and Panax ginseng that diminish clot retraction and have numerous other health benefits. Caffeic acid and diindolylmethane, both common in plants and vegetables, likewise reduce clot retraction, as do all-trans retinoic acid (a vitamin A derivative), two MAP4K inhibitors, and the chemotherapeutic drug Dasatinib. Conversely, the endogenous anticoagulant Protein S (PS) and the matricellular protein secreted modular calcium-binding protein 1 (SMOC1) both enhance clot retraction. Most studies aiming to identify mechanisms of clot retraction modulators have focused on the increased phosphorylation of vasodilator-stimulated phosphoprotein and inositol 1,4,5-triphosphate receptor I and the decreased phosphorylation of various phospholipases (e.g., phospholipase A2 (PLA2) and phosphatidylinositol-specific phospholipase Cγ2 (PLCγ2), c-Jun N-terminal kinase, and (PI3Ks). One study focused on the decreased phosphorylation of Sarcoma Family Kinases (SFK), and others have focused on increased cAMP levels and the downregulation of inflammatory markers such as thromboxanes, including thromboxane A2 (TXA2) and thromboxane B2 (TXB2); prostaglandin A2 (PGE2); reactive oxygen species (ROS); and cyclooxygenase (COX) enzyme activity. Additionally, pregnancy, fibrinolysis, and the autoimmune condition systemic lupus erythematosus all seem to affect, or at least have some relation with, clot retraction. All the clot retraction modulators need in-depth study to explain these effects.

Glycolipid-enriched fraction of Osmanthus fragrans inhibits LPS-induced expression of inflammatory genes, COX-2, E-selectin, and Interleukin-8.

Osmanthus fragrans Lour. is a small ornamental tree native to the Southeastern parts of China. It is mainly cultivated because of its characteristic fragrance, and used in the food and perfume industry. Besides, its flowers are used in traditional Chinese medicine to treat a variety of diseases including those related to inflammation. The aim of the study was to investigate in more detail the anti-inflammatory properties of O. fragrans flowers, and to characterize their active principles and mechanisms of action. O. fragrans flowers were successively extracted with n-hexane, dichloromethane and methanol. The extracts were further fractionated by chromatographic separation. COX-2 mRNA expression in PMA-differentiated, LPS-stimulated THP-1cells was used as lead assay for activity-guided fractionation. The most potent fraction was chemically analyzed by LC-HRMS. The pharmacological activity was also evaluated in other inflammation-related in-vitro models, such as analysis of IL-8 secretion and E-selectin expression in HUVECtert cells and selective inhibition of COX-isoenzymes. n-Hexane and dichloromethane extracts of O. fragrans flowers significantly inhibited COX-2 (PTGS2) mRNA expression. Additionally, both extracts inhibited COX-2 enzyme activity, whereas COX-1 enzyme activity was affected to a significantly lower extent. Fractionation of the extracts led to a highly active, glycolipid-containing fraction. In total, 10 glycolipids were tentatively annotated by LC-HRMS. This fraction also inhibited LPS-induced COX-2 mRNA expression, IL-8 secretion and E-selectin expression. The effects were limited to LPS-induced inflammation and not observed when inflammatory genes were induced by TNF-α, IL-1β or FSL-1. Since all these inducers of inflammation act via different receptors, it is likely that the fraction interferes with the binding of LPS to the TLR4-receptor, which mediates pro-inflammatory effects of LPS. Taken together, the results demonstrate the anti-inflammatory potential of O. fragrans flower extracts in general, and of the glycolipid-enriched fraction in particular. The effects of glycolipid-enriched fraction are potentially mediated via the inhibition of the TLR4 receptor complex.

Endocannabinoid turnover in GtoPdb v.2023.1

The principle endocannabinoids are 2-acylglycerol esters, such as 2-arachidonoylglycerol (2-AG), and N-acylethanolamines, such as anandamide (N-arachidonoylethanolamine, AEA). The glycerol esters and ethanolamides are synthesised and hydrolysed by parallel, independent pathways. Mechanisms for release and re-uptake of endocannabinoids are unclear, although potent and selective inhibitors of facilitated diffusion of endocannabinoids across cell membranes have been developed [29]. FABP5 (Q01469) has been suggested to act as a canonical intracellular endocannabinoid transporter in vivo [17]. For the generation of 2-arachidonoylglycerol, the key enzyme involved is diacylglycerol lipase (DAGL), whilst several routes for anandamide synthesis have been described, the best characterized of which involves N-acylphosphatidylethanolamine-phospholipase D (NAPE-PLD, [75]). A transacylation enzyme which forms N-acylphosphatidylethanolamines has been identified as a cytosolic enzyme, PLA2G4E (Q3MJ16) [66]. In vitro experiments indicate that the endocannabinoids are also substrates for oxidative metabolism via cyclooxygenase, lipoxygenase and cytochrome P450 enzyme activities [5, 24, 77].

Anti-Inflammatory Activities of Arnica montana Planta Tota versus Flower Extracts: Analytical, In Vitro and In Vivo Mouse Paw Oedema Model Studies

Arnica montana is well known for its anti-inflammatory properties. While the anti-inflammatory activity of Arnica flowers (Arnicae flos) has been extensively studied, that of the whole plant (Arnicae planta tota) is less characterized. We compared the ability of Arnicae planta tota and Arnicae flos extracts to inhibit the pro-inflammatory NF-κB-eicosanoid pathway, using several in vitro and in vivo assays. We showed that Arnicae planta tota inhibited NF-κB reporter activation, with an IC50 of 15.4 μg/mL (vs. 52.5 μg/mL for Arnicae flos). Arnicae planta tota also inhibited LPS-induced expression of ALOX5 and PTGS2 genes in human differentiated macrophages. ALOX5 and PTGS2 encode the 5-lipoxygenase (5-LO) and cyclooxygenase-2 (COX-2) enzymes that initialize the conversion of arachidonic acid into leukotrienes and prostaglandins, respectively. Arnicae planta tota inhibited 5-LO and COX-2 enzymatic activity in vitro and in human primary peripheral blood cells, with lower IC50 compared to Arnicae flos. Finally, Arnicae planta tota applied topically reduced carrageenan-induced mouse paw oedema more efficiently than Arnicae flos. Altogether, Arnicae planta tota displayed a superior anti-inflammatory activity compared to Arnicae flos, suggesting that Arnicae-planta-tota-containing products might be more effective in alleviating the manifestations of acute inflammation than those based on Arnicae flos alone.

Supramolecular, Nanostructured Assembly of Antioxidant and Antibacterial Peptides Conjugated to Naproxen and Indomethacin for the Selective Inhibition of COX-2, Biofilm, and Inflammation in Chronic Wounds.

Chronic wounds are a major healthcare challenge around the world. The presence of bacterial biofilms, accumulation of reactive oxygen species (ROS), and persistent inflammation have been identified as rate-limiting steps in chronic wound healing. Anti-inflammatory drugs, like naproxen (Npx) and indomethacin (Ind), show poor selectivity for the COX-2 enzyme, which plays a key role in producing inflammatory responses. To address these challenges, we have developed conjugates of Npx and Ind with peptides possessing antibacterial, antibiofilm, and antioxidant properties along with enhanced selectivity for the COX-2 enzyme. We have synthesized and characterized peptide conjugates Npx-YYk, Npx-YYr, Ind-YYk, and Ind-YYr, which were self-assembled into supramolecular gels. As envisaged, the conjugates and gels showed high proteolytic stability and selectivity toward the COX-2 enzyme and potent antibacterial activities (>95% within 12 h) against Gram-positive bacteria Staphylococcus aureus, implicated in wound-related infections, eradication of biofilm (∼80%), and radical scavenging (>90%) properties. Cell culture studies with mouse fibroblast cells (L929) and macrophage-like cells (RAW 264.7) showed that gels were cell proliferative in nature (120% viability), which resulted in faster and more efficient scratch healing. Treatment with gels led to a significant decrease in proinflammatory cytokine (TNF-α and IL-6) expressions and an increase in anti-inflammatory gene (IL-10) expression. The gels developed in this work show great promise as a topical agent for chronic wounds or as a coating for medical devices to prevent medical-device-associated infections.

Cuminaldehyde Effects in a MIA-Induced Experimental Model Osteoarthritis in Rat Knees.

Osteoarthritis (OA) is a chronic degenerative disease that has a significant global impact. It is associated with aging and characterized by widespread joint destruction. Cuminaldehyde is a biologically active component of essential oils that has shown promise in the treatment of nociceptive and inflammatory diseases. This study investigated the effects of cuminaldehyde on an experimental model of osteoarthritis induced in rat knees. Cuminaldehyde was found to be as effective as indomethacin in reducing pain in all evaluated tests, including forced walking, functional disability of weight distribution on the legs, and spontaneous pain in animals with osteoarthritis. The knees of animals treated with cuminaldehyde had significantly higher radiographic and histopathological scores than those of animals that did not receive the treatment. Cuminaldehyde also modulated the production of pro-inflammatory cytokines. In vitro assays showed that cuminaldehyde preferentially inhibits COX-2 enzyme activity. In silico studies demonstrated that cuminaldehyde has satisfactory energy affinity parameters with opioid receptors and COX-2. These findings suggest that cuminaldehyde's anti-inflammatory activity is multifactorial, acting through multiple pathways. Its nociceptive activity occurs via central and peripheral mechanisms. Cuminaldehyde modulates the immune response of the inflammatory process and may be considered a leading compound for the development of new anti-inflammatory and analgesic drugs.

Bioactivity of Purple Sweet Potato (Ipomea batatas) as Anti Inflammatory Agent: Review

This Inflammation is a defensive response to tissue damage that occurs locally. NSAID (Non Steroid Anti-Inflammatory Drugs) and AIS (Antiinflammatory Steroids) have been used in Indonesia to treat inflammation but have side effects on the body. Purple sweet potato leaf (Ipomoea batatas) is one of the herbal medicines used by the community to treat inflammation. This research is a literature review by collecting information from Google Scholar, PubMed, Scopus, and Garuda. The results showed that the active anti-inflammatory compounds in purple sweet potato leaves were flavonoids. Flavonoids can work as anti-inflammatory compounds by passing through several pathways such as inhibition of cyclooxygenase (COX) and lipoxygenase enzyme activities, inhibition of neutrophil degranulation, inhibition of histamine increase, and inhibition of leukocyte accumulation. Purple sweet potato (Ipomoea batatas) leaves are scientifically proven to have anti-inflammatory activity as evidenced by the presence of compounds that have anti-inflammatory effects and can be developed into products for inflammation.

Rheum rhaponticum and Rheum rhabarbarum Extracts as Modulators of Endothelial Cell Inflammatory Response.

Inflammation, endothelial dysfunction, and alterations in blood physiology are key factors contributing to atherosclerosis and other cardiovascular disorders. Hence, modulation of endothelial function and reducing its pro-inflammatory and pro-thrombotic activity is considered one of the most important cardioprotective strategies. This study aimed to evaluate the anti-inflammatory potential of rhubarb extracts isolated from petioles and underground organs of Rheum rhabarbarum L. (garden rhubarb) and R. rhaponticum L. (rhapontic rhubarb) as well as two stilbenoids, typically found in these plants, i.e., rhapontigenin (RHPG) and its glycoside, rhaponticin (RHPT). Analysis of the anti-inflammatory effects of the indicated rhubarb-derived substances involved different aspects of the endothelial cells' (HUVECs) response: release of the inflammatory mediators; cyclooxygenase (COX-2) and 5-lipoxygenase (5-LOX) expression as well as the recruitment of leukocytes to the activated HUVECs. The ability of the rhubarb-derived extracts to inhibit COX-2 and 5-LOX activities was examined as well. The study was supplemented with the in silico analysis of major components of the analyzed extracts' interactions with COX-2 and 5-LOX. The obtained results indicated that the examined plant extracts and stilbenes possess anti-inflammatory properties and influence the inflammatory response of endothelial cells. Biochemical and in silico tests revealed significant inhibition of COX-2, with special importance of rhaponticin, as a compound abundant in both plant species. In addition to the reduction in COX-2 gene expression and enzyme activity, a decrease in the cytokine level and leukocyte influx was observed. Biochemical tests and computational analyses indicate that some components of rhubarb extracts may act as COX-2 inhibitors, with marginal inhibitory effect on 5-LOX.

Disconnect between COX-2 selective inhibition and cardiovascular risk in preclinical models

IntroductionSecondary pharmacology profiling is routinely applied in pharmaceutical drug discovery to investigate the pharmaceutical effects of a drug at molecular targets distinct from (off-target) the intended therapeutic molecular target (on-target). Data from a randomized, placebo-controlled clinical trial, the APPROVe (Adenomatous Polyp Prevention on VIOXX, rofecoxib) trial, raised significant concerns about COX-2 inhibition as a primary or secondary target, shaping the screening and decision-making processes of some pharmaceutical companies. COX-2 is often included in off-target screens due to cardiovascular (CV) safety concerns about secondary interactions with this target. Several potential mechanisms of COX-2-mediated myocardial infarctions have been considered including, effects on platelet stickiness/aggregation, vasal tone and blood pressure, and endothelial cell activation. In the present study, we focused on each of these mechanisms as potential effects of COX-2 inhibitors, to find evidence of mechanism using various in vitro and in vivo preclinical models. MethodsCompounds tested in the study, with a range of COX-2 selectivity, included rofecoxib, celecoxib, etodolac, and meloxicam. Compounds were screened for inhibition of COX-2 vs COX-1 enzymatic activity, ex vivo platelet aggregation (using whole blood from multiple species), ex vivo canine femoral vascular ring model, in vitro human endothelial cell activation (with and without COX-2 induction), and in vivo cardiovascular assessment (anesthetized dog). ResultsThe COX-2 binding assessment generally confirmed the COX-2 selectivity previously reported. COX-2 inhibitors did not have effects on platelet function (spontaneous aggregation or inhibition of aggregation), cardiovascular parameters (mean arterial pressure, heart rate, and left ventricular contractility), or endothelial cell activation. However, rofecoxib uniquely produced an endothelial mediated constriction response in canine femoral arteries. ConclusionOur data suggest that rofecoxib-related cardiovascular events in humans are not predicted by COX-2 potency or selectivity. In addition, the vascular ring model suggested possible adverse cardiovascular effects by COX-2 inhibitors, although these effects were not seen in vivo studies. These results may also suggest that COX-2 inhibition alone is not responsible for rofecoxib-mediated adverse cardiovascular outcomes.

Effect of Oral Intake of Carrot Juice on Cyclooxygenases and Cytokines in Healthy Human Blood Stimulated by Lipopolysaccharide.

In vitro studies and animal studies have shown that chemical compounds contained in carrots, such as falcarinol and falcarindiol, can prevent inflammation. The present study was designed to test whether the oral intake of carrot juice containing falcarinol and falcarindiol affects the activity of cyclooxygenase (COX) enzymes and the secretion of inflammatory cytokines in human blood. Carrot juice (500 mL) was administered orally to healthy volunteers, and blood samples were drawn before and 1 h after juice intake at the time point when peak concentrations of falcarinol and falcariondiol have been shown in the blood. The blood samples were divided, and one sample was allowed to coagulate for 1 h at room temperature before analyzing the synthesis of thromboxane B2 (TBX2) by the COX1 enzyme using an enzyme linked immunosorbent assay (ELISA). The other blood samples were stimulated ex vivo with lipopolysaccharide and incubated at 37 °C for 24 h. The ELISA and cytokine multiplex analysis assessed the levels of COX-2-induced prostaglandin E2 (PGE2) and inflammatory markers interleukin (IL) 1α, IL1β, IL6, IL16, and tumor necrosis factor α (TNFα). Inflammatory cytokines such as IL1α and IL16 were significantly reduced in the LPS stimulated blood samples with higher concentrations of falcarinol and falcariondiol compared to the control samples taken before the intake of carrot juice. The levels of TBX2, PGE2, IL1β, IL6, and TNFα were not affected by the carrot juice intake blood samples not stimulated with LPS. In conclusion, carrot juice rich in the polyacetylens falcarinol and falcarindiol affects blood leukocytes, priming them to better cope with inflammatory conditions, evident by the reduced secretion of the proinflammatory cytokines IL1α and IL16.

Neuropeptide W Exhibits Preventive and Therapeutic Effects on Acetic Acid-Induced Colitis via Modulation of the Cyclooxygenase Enzyme System.

The novel peptide neuropeptide W (NPW) was originally shown to function in the control of feeding behavior and energy homeostasis. The aim of this study was to elucidate the putative preventive and therapeutic effects of NPW on colitis-associated oxidative injury and the underlying mechanisms for its action. Sprague-Dawley rats in the acute colitis groups received NPW (0.5, 1 or 5µg/kg/day) injections prior to induction of colitis with acetic acid, while the chronic colitis groups were treated after the induction of colitis. In both acute and chronic colitis (CC) groups, treatments were continued for 5days and the rats were decapitated at the 24th hour of the last injections and colon tissues were collected for assessments. NPW pretreatment given for 5days before colitis induction, as well as treating rats with NPW during the 5-day course of CC, abolished colonic lipid peroxidation. NPW treatment prevented colitis-induced reduction in blood flow, diminished neutrophil infiltration, and pro-inflammatory cytokine responses. NPW pretreatment only at the higher dose reduced colonic edema and microscopic score and preserved colonic glutathione stores. Elevations in cyclooxygenase (COX) enzyme activity and COX-1 protein level during the acute phase of colitis as well as reduction in COX-2 were all reversed with NPW pretreatment. In contrast, NPW treatment was effective in reducing the elevated COX-2 concentration during the chronic phase. NPW alleviates acetic acid-induced oxidative colonic injury in rats through the upregulation of colonic blood flow as well as the inhibition of COX-2 protein expression and pro-inflammatory cytokine production.

"GREEN SYNTHESIS OF NANO-SILVER/SODIUM ALGINATE/CARBOXYMETHYL XANTHAN GUM HYDROGEL AND EVALUATION OF ITS ANTI-INFLAMMATORY AND ANTI-Helicobacter pylori ACTIVITY "

A crosslinked sodium alginate (SA)/carboxymethyl xanthan gum (CMXG) hydrogel was prepared by blending an equivalent weight ratio of SA and CMXG, followed by crosslinking using CaCl2. Moreover, two nanocomposites were prepared by in situ dispersion of two different concentrations of silver nanoparticles (AgNPs) into the matrix of the prepared hydrogel. The analysis displayed that the order of COX-2 inhibition by the tested samples was SA ˂ CMXG ˂ crosslinked SA/CMXG hydrogel ˂ SA/CMXG/AgNPs1% ˂ SA/CMXG/AgNPs3% ˂ Celecoxib. AgNP composites exhibited a potent inhibition tendency, and their activity increased with increasing the AgNPs content. The recorded MIC values revealed that the MIC values that cause 50% inhibition (IC50) of COX-2 enzyme activity were 14.2 and 3.6 µg/mL for SA/CMXG/AgNPs1% and SA/CMXG/AgNPs3%, respectively, corresponding to 0.28 µg/mL for the standard drug Celecoxib. Moreover, SA/CMXG/AgNPs composites showed a greater inhibition efficiency of H. pylori than their parent SA/CMXG hydrogel. Their inhibitory efficiency increased with increasing their AgNPs content; SA/CMXG/AgNPs1% and SA/CMXG/AgNPs3% exhibited 100% inhibition against H. pylori growth at MIC of 3.9 and 1.95 µg/mL, respectively. The anti-H. pylori activity of SA/CMXG/AgNPs 3% was higher than that of the standard drug Clarithromycin, especially at the low concentrations ranging from 0.24 to 0.98 µg/mL. These results make SA/CMXG/AgNPs3% a promising anti-H. pylori agent.

Anti-Inflammatory Potential of Brucea javanica Fruit

Objective: Inflammation plays a crucial role in the progression of many diseases, excessive inflammation increases immune cell activation, which can destroy tissues and body health. When inflammation occurs, multiple pro-inflammatory mediators are overproduced, leading to a variety of diseases such as rheumatism, diabetes, and cardiovascular problems. Brucea javanica has been used as traditional medicine as a therapy for anti-tumor, amebic dysentery, diarrhea, malaria, and intestinal inflammation. Therefore, in this study, we explored the effect of ethanol extract Brucea javanica Fruit on anti-inflammation activity in carrageenan-induced rat paw edema and the COX-2 inhibitory effect in vivo.&#x0D; Methods: In vivo anti-inflammatory activity of the ethanolic extracts was evaluated using the carrageenan-induced rat paws edema method at doses of 50, 100, and 200mg/kg and further investigated the effect of Cyclooxygenase-2 inhibitory using ELISA readers.&#x0D; Results: The ethanolic extract of Brucea javanica Fruit exhibited anti-inflammatory activity by oral intake of 50 mg/kg of the ethanolic extract and Brucea javanica inhibited rat paw edema by 50.91% significantly compared to Celecoxib by 58.52%. Moreover, Brucea javanica showed COX-2 inhibition by 16,40% compared to Celecoxib by 20,50%.&#x0D; Conclusions: These findings indicate that Brucae javanica Fruit extracts have promising anti-inflammatory activity directed against COX-2 enzymatic activity.&#x0D; Keywords: Anti-inflammatory, Brucea javanica, Malur, Buah Makasar, Cyclooxygenase.