Neuropeptide W facilitates chronic gastric ulcer healing by the regulation of cyclooxygenase and NF-κB signaling pathways.

AIMS: Putative beneficial effects of neuropeptide W (NPW) in the early phase of gastric ulcer healing process and the involvement of cyclooxygenase (COX) enzymes were investigated in an acetic acid-induced gastric ulcer model. MAIN METHODS: In anesthetized male Sprague-Dawley rats, acetic acid was applied surgically on the serosa and then a COX-inhibitor (COX-2-selective NS-398, COX-1-selective ketorolac, or non-selective indomethacin; 2 mg/kg/day, 3 mg/kg/day or 5 mg/kg/day; respectively) or saline was injected intraperitoneally. One h after ulcer induction, omeprazole (20 mg/kg/day), NPW (0.1 µg/kg/day) or saline was intraperitoneally administered. Injections of NPW, COX-inhibitors, omeprazole or saline were continued for the following 2 days until rats were decapitated at the end of the third day. KEY FINDINGS: NPW treatment depressed gastric prostaglandin (PG) I2 level, but not PGE2 level. Similar to omeprazole, NPW treatment significantly reduced gastric and serum tumor necrosis factor-alpha and interleukin-1 beta levels and depressed the upregulation of nuclear factor kappa B (NF-κB) and COX-2 expressions due to ulcer. In parallel with the histopathological findings, treatment with NPW suppressed ulcer-induced increases in myeloperoxidase activity and malondialdehyde level and replenished glutathione level. However, the inhibitory effect of NPW on myeloperoxidase activity and NPW-induced increase in glutathione were not observed in the presence of COX-1 inhibitor ketorolac or the non-selective COX-inhibitor indomethacin. SIGNIFICANCE: In conclusion, NPW facilitated the healing of gastric injury in rats via the inhibition of pro-inflammatory cytokine production, oxidative stress and neutrophil infiltration as well as the downregulation of COX-2 protein and NF-κB gene expressions.

M2 Macrophage Membrane-Mediated Biomimetic-Nanoparticle Carrying COX-siRNA Targeted Delivery for Prevention of Tendon Adhesions by Inhibiting Inflammation.

Tendon adhesion is the most common outcome of tendon or tendon-to-bone healing after injury. Our group developed a hydrogel-nanoparticle sustained-release system previously to inhibit cyclooxygenases (COXs) expression and consequently prevent tendon adhesion and achieved satisfactory results. However, effective treatment of multiple tendon adhesions is always a challenge in research on the prevention of tendon adhesion. In the present study, an M2M@PLGA/COX-siRNA delivery system is successfully constructed using the cell membranes of M2 macrophages and poly (lactic-co-glycolic acid) (PLGA) nanoparticles. Targeting properties and therapeutic effects are observed in mice or rat models of flexor digitorum longus (FDL) tendon injury combined with rotator cuff injury. The results showed that the M2M@PLGA/COX-siRNA delivery system has low toxicity and remarkable targeting properties to the injured areas. Treatment with the M2M@PLGA/COX-siRNA delivery system reduced the inflammatory reaction and significantly improved tendon adhesion in both the FDL tendon and rotator cuff tissues. These findings indicate that the M2M@PLGA delivery system can provide an effective biological strategy for preventing multiple tendon adhesions.

Synthesis, biological evaluation and molecular docking study of some new 4-aminosalicylic acid derivatives as anti-inflammatory and antimycobacterial agents.

In this study, new derivatives of the antitubercular and anti-inflammatory drug, 4-aminosaliclic acids (4-ASA) were synthesized, characterized, and evaluated for these activities. In vivo and in viro evaluation of anti-inflammatory activity revealed that compounds 10, 19 and 20 are the most active with potent cyclooxygenase-2 (COX-2) and 5-lipooxgenase (5-LOX) inhibition and without causing gasric lesions. The minimum inhibitory concentrations (MIC) of the newly synthesized compound were, also, measured against Mycobacterium tuberculosis H37RV. Among the tested compounds 17, 19 and 20 exhibited significant activities against the growth of M. tuberculosis. 20 is the most potent with (MIC 1.04 µM) 2.5 folds more potent than the parent drug 4-ASA. 20 displayed low cytotoxicity against normal cell providing a high therapeutic index. Important structure features were analyzed by docking and structure-activity relationship analysis to give better insights into the structural determinants for predicting the anti-inflammatory and anti-TB activities. Our results indicated that compounds 19 and 20 are potential lead compounds for the discovery of dual anti-inflammatory and anti-TB drug candidates.

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

BACKGROUND: 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. METHODS: Sprague-Dawley rats in the acute colitis groups received NPW (0.5, 1 or 5 µg/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 5 days and the rats were decapitated at the 24th hour of the last injections and colon tissues were collected for assessments. RESULTS: NPW pretreatment given for 5 days 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. CONCLUSIONS: 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.

Aspirin sensitivity of PIK3CA-mutated Colorectal Cancer: potential mechanisms revisited.

PIK3CA mutations are amongst the most prevalent somatic mutations in cancer and are associated with resistance to first-line treatment along with low survival rates in a variety of malignancies. There is evidence that patients carrying PIK3CA mutations may benefit from treatment with acetylsalicylic acid, commonly known as aspirin, particularly in the setting of colorectal cancer. In this regard, it has been clarified that Class IA Phosphatidylinositol 3-kinases (PI3K), whose catalytic subunit p110α is encoded by the PIK3CA gene, are involved in signal transduction that regulates cell cycle, cell growth, and metabolism and, if disturbed, induces carcinogenic effects. Although PI3K is associated with pro-inflammatory cyclooxygenase-2 (COX-2) expression and signaling, and COX-2 is among the best-studied targets of aspirin, the mechanisms behind this clinically relevant phenomenon are still unclear. Indeed, there is further evidence that the protective, anti-carcinogenic effect of aspirin in this setting may be mediated in a COX-independent manner. However, until now the understanding of aspirin's prostaglandin-independent mode of action is poor. This review will provide an overview of the current literature on this topic and aims to analyze possible mechanisms and targets behind the aspirin sensitivity of PIK3CA-mutated cancers.

Synthesis and In Vitro Biological Evaluation of p-Carborane-Based Di-tert-butylphenol Analogs.

Targeting inflammatory mediators and related signaling pathways may offer a rational strategy for the treatment of cancer. The incorporation of metabolically stable, sterically demanding, and hydrophobic carboranes in dual cycloxygenase-2 (COX-2)/5-lipoxygenase (5-LO) inhibitors that are key enzymes in the biosynthesis of eicosanoids is a promising approach. The di-tert-butylphenol derivatives R-830, S-2474, KME-4, and E-5110 represent potent dual COX-2/5-LO inhibitors. The incorporation of p-carborane and further substitution of the p-position resulted in four carborane-based di-tert-butylphenol analogs that showed no or weak COX inhibition but high 5-LO inhibitory activities in vitro. Cell viability studies on five human cancer cell lines revealed that the p-carborane analogs R-830-Cb, S-2474-Cb, KME-4-Cb, and E-5110-Cb exhibited lower anticancer activity compared to the related di-tert-butylphenols. Interestingly, R-830-Cb did not affect the viability of primary cells and suppressed HCT116 cell proliferation more potently than its carbon-based R-830 counterpart. Considering all the advantages of boron cluster incorporation for enhancement of drug biostability, selectivity, and availability of drugs, R-830-Cb can be tested in further mechanistic and in vivo studies.

Triterpenoids of Three Apple Cultivars-Biosynthesis, Antioxidative and Anti-Inflammatory Properties, and Fate during Processing.

Triterpenoids are a group of secondary plant metabolites, with a remarkable pharmacological potential, occurring in the cuticular waxes of the aerial parts of plants. The aim of this study was to analyze triterpenoid variability in the fruits and leaves of three apple cultivars during the growing season and gain new insights into their health-promoting properties and fate during juice and purée production. The identification and quantification of the compounds of interest were conducted using gas chromatography coupled with mass spectrometry. The waxes of both matrices contained similar analytes; however, their quantitative patterns varied: triterpenic acids prevailed in the fruits, while higher contents of steroids and esterified forms were observed in the leaves. The total triterpenoid content per unit area was stable during the growing season; the percentage of esters increased in the later phases of growth. Antioxidative and anti-inflammatory properties were evaluated with a series of in vitro assays. Triterpenoids were found to be the main anti-inflammatory compounds in the apples, while their impact on antioxidant capacity was minor. The apples were processed on a lab scale to obtain juices and purées. The apple purée and cloudy juice contained only some of the triterpenoids present in the raw fruit, while the clear juices were virtually free of those lipophilic compounds.

A New EGFR Inhibitor from Ficus benghalensis Exerted Potential Anti-Inflammatory Activity via Akt/PI3K Pathway Inhibition.

Inflammation is a critical defensive mechanism mainly arising due to the production of prostaglandins via cyclooxygenase enzymes. This study aimed to examine the anti-inflammatory activity of fatty acid glucoside (FAG), which is isolated from Ficus benghalensis against lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The cytotoxic activity of the FAG on RAW 264.7 macrophages was evaluated with an MTT assay. The levels of PGE2 and NO and the activity of iNOS, COX-1, and COX-2 enzymes in LPS-stimulated RAW 264.7 cells were evaluated. The gene expression of IL-6, TNF-α, and PGE2 was investigated by qRT-PCR. The expression of epidermal growth factor receptor (EGFR), Akt, and PI3K proteins was examined using Western blotting analysis. Furthermore, molecular docking of the new FAG against EGFR was investigated. A non-cytotoxic concentration of FAG increased NO release and iNOS activity, inhibited COX-1 and COX-2 activities, and reduced PGE2 levels in LPS-stimulated RAW 264.7 cells. It diminished the expression of TNF-α, IL-6, PGE2, EGFR, Akt, and PI3K. Furthermore, the molecular docking study proposed the potential direct binding of FAG with EGFR with a high affinity. This study showed that FAG is a natural EGFR inhibitor, NO-releasing, and COX-inhibiting anti-inflammatory agent via EGFR/Akt/PI3K pathway inhibition.

The specific deletion of cyclooxygenase-1 in megakaryocytes/platelets reduces intestinal polyposis in ApcMin/+ mice.

Clinical and experimental evidence sustain the role of cyclooxygenase (COX)-1 in intestinal tumorigenesis. However, the cell type expressing the enzyme involved and molecular mechanism(s) have not been clarified yet. We aimed to elucidate the role of platelet COX-1 (the target of low-dose aspirin in humans) in intestinal tumorigenesis of ApcMin/+ mice, considered a clinically relevant model. To realize this objective, we generated an ApcMin/+ mouse with a specific deletion of Ptgs1(COX-1 gene name) in megakaryocytes/platelets (ApcMin/+;pPtgs1-/-mice) characterized by profound inhibition of thromboxane(TX)A2 biosynthesis ex vivo (serum TXB2; by 99%) and in vivo [urinary 2,3-dinor-TXB2(TXM), by 79%]. ApcMin/+ mice with the deletion of platelet COX-1 showed a significantly reduced number (67%) and size (32%) of tumors in the small intestine. The intestinal adenomas of these mice had decreased proliferative index associated with reduced COX-2 expression and systemic prostaglandin(PG)E2 biosynthesis (urinary PGEM) vs. ApcMin/+mice. Extravasated platelets were detected in the intestine of ApcMin/+mice. Thus, we explored their contribution to COX-2 induction in fibroblasts, considered the primary polyp cell type expressing the protein. In the coculture of human platelets and myofibroblasts, platelet-derived TXA2 was involved in the induction of COX-2-dependent PGE2 in myofibroblasts since it was prevented by the selective inhibition of platelet COX-1 by aspirin or by a specific antagonist of TXA2 receptors. In conclusion, our results support the platelet hypothesis of intestinal tumorigenesis and provide experimental evidence that selective inhibition of platelet COX-1 can mitigate early events of intestinal tumorigenesis by restraining COX-2 induction.

PTGES3 is a Putative Prognostic Marker in Breast Cancer.

BACKGROUND: The COX/prostaglandin (COX/PG) pathway plays a role in cancer pathogenesis via the production of prostaglandin E2 (PGE2). In breast cancer, the expression patterns of the COX/PG pathway enzymes involved in PGE2 synthesis are not well defined. MATERIALS AND METHODS: Using the Cancer Genome Atlas data, we analyzed the expression patterns of cyclooxygenases, COX1 (PTGS1) and COX2 (PTGS2), and four downstream enzymes of the COX/prostaglandin pathway - PTGS3 (PTGDS), PTGES1, PTGES2 and PTGES3 - in invasive breast cancer. The Clinical Proteomic Tumor Analysis Consortium database was used to determine the expression of these six genes at the protein level. Existing single-cell RNA sequencing data were used to evaluate the expression of the six COX/PG genes in luminal and basal epithelial cells from normal breast tissues. Cox regression Kaplan-Meier adjusted survival analyses were performed to evaluate the association of COX/PG pathway genes in overall survival using the TCGA data. Finally, we utilized the Tumor Immune Estimation Resource to correlate the expression of these six COX/PG genes with tumor infiltrating immune cell number. RESULTS: COX1, COX2 and PTGES3 were significantly upregulated at the protein level in breast cancer compared to normal tissues (P < 0.005). However, only PTGES3 expression was elevated at both the mRNA and protein level in breast cancer (P < 0.0005). PTGES3 is the most highly expressed enzymes within the COX/PG pathway in both luminal and basal epithelial cells in normal breast tissues. Using Cox Regression Kaplan-Meier survival analysis, PTGES3 expression had a significant inverse prognostic association with breast cancer survival [HR >1.43, P = 0.0057]. Elevated PTGES3 expression within the tumor microenvironment significantly correlated with CD8+ T cell abundance, suggesting a possible immunomodulatory role of PTGES3 in the tumor microenvironment. CONCLUSIONS: PTGES3, a terminal synthetase in the COX/prostaglandin pathway, is a putative prognostic marker in breast cancer.

Inhibition of Both Cyclooxygenase-1 and -2 Promotes Epicutaneous Th2 and Th17 Sensitization and Allergic Airway Inflammation on Subsequent Airway Exposure to Protease Allergen in Mice.

INTRODUCTION: Epicutaneous (e.c.) allergen exposure is an important route of sensitization toward allergic diseases in the atopic march. Allergen sources such as house dust mites contain proteases that involve in the pathogenesis of allergy. Prostanoids produced via pathways downstream of cyclooxygenases (COXs) regulate immune responses. Here, we demonstrate effects of COX inhibition with nonsteroidal anti-inflammatory drugs (NSAIDs) on e.c. sensitization to protease allergen and subsequent airway inflammation in mice. METHODS: Mice were treated with NSAIDs during e.c. sensitization to a model protease allergen, papain, and/or subsequent intranasal challenge with low-dose papain. Serum antibodies, cytokine production in antigen-restimulated skin or bronchial draining lymph node (DLN) cells, and airway inflammation were analyzed. RESULTS: In e.c. sensitization, treatment with a nonspecific COX inhibitor, indomethacin, promoted serum total and papain-specific IgE response and Th2 and Th17 cytokine production in skin DLN cells. After intranasal challenge, treatment with indomethacin promoted allergic airway inflammation and Th2 and Th17 cytokine production in bronchial DLN cells, which depended modestly or largely on COX inhibition during e.c. sensitization or intranasal challenge, respectively. Co-treatment with COX-1-selective and COX-2-selective inhibitors promoted the skin and bronchial DLN cell Th cytokine responses and airway inflammation more efficiently than treatment with either selective inhibitor. CONCLUSION: The results suggest that the overall effects of COX downstream prostanoids are suppressive for development and expansion of not only Th2 but also, unexpectedly, Th17 upon exposure to protease allergens via skin or airways and allergic airway inflammation.

Relation between ABCB1 overexpression and COX2 and ALOX5 genes in human erythroleukemia cell lines.

This study aimed to characterize the relationship between the COX2 and ALOX5 genes, as well as their link with the multidrug resistance (MDR) phenotype in sensitive (K562) and MDR (K562-Lucena and FEPS) erythroleukemia cells. For this, the inhibitors of 5-LOX (zileuton) and COX-2 (acetylsalicylic acid-ASA) and cells with the silenced ABCB1 gene were used. The treatment with ASA caused an increase in the gene expression of COX2 and ABCB1 in both MDR cell lines, and a decrease in the expression of ALOX5 in the FEPS cells. Silencing the ABCB1 gene induced a decrease in COX2 expression and an increase in the ALOX5 gene. Treatment with zileuton did not alter the expression of COX2 and ABCB1. Cytometry data showed that there was an increase in ABCB1 protein expression after exposure to ASA. In addition, the increased activity of ABCB1 in the K562-Lucena cell line indicates that ASA may be a substrate for this efflux pump, corroborating the molecular docking that showed that ASA can bind to ABCB1. Regardless of the genetic alteration in COX2 and ABCB1, the direct relationship between these genes and the inverse relationship with ALOX5 remained in the MDR cell lines. We assume that ABCB1 can play a regulatory role in COX2 and ALOX5 during the transformation of the parental cell line K562, explaining the increased gene expression of COX2 and decreased ALOX5 in the MDR cell lines.

Role of cyclooxygenases and prostaglandins in adult brain neurogenesis.

The telencephalon of adult mammals shows constitutive neurogenesis, and disease or traumatic injuries alter the rate of neurogenesis in the adult brain. Understanding the molecular signals that control adult brain neurogenesis is of crucial importance for the development of therapies to promote regeneration in the injured or diseased brain. Here, I reviewed our current knowledge on the role of cyclooxygenases and prostaglandins in controlling adult brain neurogenesis. Current data indicate that cyclooxygenase-2 derived prostaglandin E2 acting through EP receptors promotes neurogenesis in adult neurogenic niches of the telencephalon and that manipulations of this signalling pathway could be used to promote neurogenesis under pathological conditions. In this review article, I also propose new research directions to increase our knowledge on the role of this signalling pathway in neurogenesis.

Tailoring the substitution pattern of Pyrrolidine-2,5-dione for discovery of new structural template for dual COX/LOX inhibition.

Dual inhibition of the enzymatic pathways of cyclooxygenases (COX-1/COX-2) and lipoxygenase (LOX) is a rational approach for developing more efficient and safe anti-inflammatory agents. Herein, dual inhibitors of COX and LOX for the management of inflammation are reported. The structural modifications of starting pyrrolidine-2,5-dione aldehyde derivatives resulted in two structurally diverse families (Family A & B). Synthesized derivatives from both Families displayed preferential COX-2 affinity in submicromolar to nanomolar ranges. Disubstitution pattern of the most active series of compounds having N-(benzyl(4-methoxyphenyl)amino moiety presents a new template that is mimic to the diaryl pattern of traditional COX-2 inhibitors. Compound 78 with IC50 value of 0.051 ± 0.001 µM emerged as the most active compound. Highly potent COX-2/5-LOX inhibitors have also demonstrated appreciable in-vivo anti-inflammatory activity through carrageenan induced paw edema test. Moreover, the involvement of histamine, bradykinin, prostaglandin, and leukotriene mediators to adjust the inflammatory response were also studied. Apart from COX inhibition, sulfonamide is considered an important template for carbonic anhydrase inhibition. Hence, we also evaluated six sulfonamide derivatives for off-target in-vitro bovine carbonic anhydrase-II inhibition. Biological results were finally rationalized by docking simulations. Typically, most active COX-2 inhibitors interact with the amino acid residues responsible for the COX-2 selectivity.

In Vitro Effects of Selective COX and LOX Inhibitors and Their Combinations with Antineoplastic Drugs in the Mouse Melanoma Cell Line B16F10.

The constitutive expression or overactivation of cyclooxygenase (COX) and lipoxygenase (LOX) enzymes results in aberrant metabolism of arachidonic acid and poor prognosis in melanoma. Our aim is to compare the in vitro effects of selective COX-1 (acetylsalicylic acid), COX-2 (meloxicam), 5-LOX (MK-886 and AA-861), 12-LOX (baicalein) and 15-LOX (PD-146176) inhibition in terms of proliferation (SRB assay), mitochondrial viability (MTT assay), caspase 3-7 activity (chemiluminescent assay), 2D antimigratory (scratch assay) and synthesis of eicosanoids (EIA) in the B16F10 cell line (single treatments). We also explore their combinatorial pharmacological space with dacarbazine and temozolomide (median effect method). Overall, our results with single treatments show a superior cytotoxic efficacy of selective LOX inhibitors over selective COX inhibitors against B16F10 cells. PD-146176 caused the strongest antiproliferation effect which was accompanied by cell cycle arrest in G1 phase and an >50-fold increase in caspases 3/7 activity. When the selected inhibitors are combined with the antineoplastic drugs, only meloxicam provides clear synergy, with LOX inhibitors mostly antagonizing. These apparent contradictions between single and combination treatments, together with some paradoxical effects observed in the biosynthesis of eicosanoids after FLAP inhibition in short term incubations, warrant further mechanistical in vitro and in vivo scrutiny.

An Investigation into the Interaction between Double Hydroxide-Based Antioxidant Benzophenone Derivatives and Cyclooxygenase 2.

Cyclooxygenases 2 (COX2) is a therapeutic target for many inflammation and oxidative stress associated diseases. A high-throughput technique, biolayer interferometry, was performed to primarily screen the potential COX2 binding activities of twelve newly synthesized double hydroxide-based benzophenone derivatives. Binding confirmation was achieved by molecular docking and multi-spectroscopy studies. Such a combined method provided a comprehensive understanding of binding mechanism and conformational changes. Compounds DB2, SC2 and YB2 showed effective COX2 binding activity and underlined the benefits of three phenolic hydroxyl groups adjacent to each other on the B ring. The twelve tested derivatives were further evaluated for antioxidant activity, wherein compound SC2 showed the highest activity. Its concentration for the 50% of maximal effect (EC50) value was approximately 1000 times greater than that of the positive controls. SC2 treatment effectively improved biochemical indicators caused by oxidative stress. Overall, compound SC2 could serve as a promising candidate for further development of a new potent COX2 inhibitor.

Synthesis, Characterization, Molecular Docking, and Biological Activities of Some Natural and Synthetic Urolithin Analogs.

Urolithins (that is, hydroxy substituted benzo[c]chromen-6-one derivatives) are formed within the gastrointestinal tract following to the exposure to various ellagitannin rich diet, particularly involving pomegranate, nuts, and berries. Regarding the bioavailability deficiency of ellagitannins, the biological activities obtained through the extracts of these dietaries are attributed to the urolithin compounds, since they are bioavailable. Particularly, there are studies indicating the importance of ellagitannin-rich food for protective and alternative treatment of Alzheimer's Disease (AD). From this perspective, within this study, the major urolithins (that is, urolithins A and B), their methyl ether metabolites, as well as some synthetic urolithin analogs have been synthesized and screened for their biological activities in various enzyme inhibition (acetylcholinesterase, butyrylcholinesterase, monoamine oxidase B, cyclooxygenase 1, and cyclooxygenase 2) and antioxidant (DPPH radical scavenging) assay systems. The results pointed out the potential of urolithins to act as inhibitors on these receptors. Docking studies were also performed to investigate the possible interactions.

Lead (Pb) as a Factor Initiating and Potentiating Inflammation in Human THP-1 Macrophages.

The aim of this study was to assess the influence of lead (Pb) at low concentrations (imitating Pb levels in human blood in chronic environmental exposure to this metal) on interleukin 1ß (IL-1ß) and interleukin 6 (IL-6) concentrations and the activity and expression of COX-1 and COX-2 in THP-1 macrophages. Macrophages were cultured in vitro in the presence of Pb at concentrations of: 1.25 µg/dL; 2.5 µg/dL; 5 µg/dL; 10 µg/dL. The first two concentrations of Pb were selected on the basis of our earlier study, which showed that Pb concentration in whole blood (PbB) of young women living in the northern regions of Poland and in the cord blood of their newborn children was within this range (a dose imitating environmental exposure). Concentrations of 5 µg/dL and 10 µg/dL correspond to the previously permissible PbB concentrations in children or pregnant women, and adults. Our results indicate that even low concentrations of Pb cause an increase in production of inflammatory interleukins (IL-1ß and IL-6), increases expression of COX-1 and COX-2, and increases thromboxane B2 and prostaglandin E2 concentration in macrophages. This clearly suggests that the development of inflammation is associated not only with COX-2 but also with COX-1, which, until recently, had only been attributed constitutive expression. It can be concluded that environmental Pb concentrations are able to activate the monocytes/macrophages similarly to the manner observed during inflammation.

Oral Intake of EPA:DHA 6:1 by Middle-Aged Rats for One Week Improves Age-Related Endothelial Dysfunction in Both the Femoral Artery and Vein: Role of Cyclooxygenases.

In humans, aging is associated with endothelial dysfunction and an increased risk of venous thromboembolism. Although intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at a ratio of 6:1 by old rats improved the endothelial dysfunction in arteries, the impact on veins remains unclear. Eight-month-old male Wistar rats were either untreated or orally administered corn oil, EPA:DHA 1:1, or EPA:DHA 6:1 (500 mg/kg/d) for seven days. Vascular reactivity was studied by myography. In middle-aged femoral artery rings, acetylcholine caused a partial relaxation at low concentrations and a contractile response at high concentrations, whereas in the old femoral vein only a partial relaxation was observed. The EPA:DHA 6:1 treatment blunted the contractile response to acetylcholine in the middle-aged femoral artery and both EPA:DHA 6:1 and 1:1 increased the relaxation to acetylcholine in the old femoral vein. No such effects were observed with corn oil. Both the non-selective cyclooxygenase inhibitor indomethacin and the COX-1 inhibitor SC-560 increased the relaxation to acetylcholine in the middle-aged femoral artery whereas the COX-2 inhibitor NS-398 increased that in the middle-aged femoral vein. In conclusion, our results indicate that aging is associated with an endothelial dysfunction in the femoral artery and vein, which can be improved by EPA:DHA 6:1 treatment-most likely via a cyclooxygenase-dependent mechanism.

Pre- and Neonatal Exposure to Lead (Pb) Induces Neuroinflammation in the Forebrain Cortex, Hippocampus and Cerebellum of Rat Pups.

Lead (Pb) is a heavy metal with a proven neurotoxic effect. Exposure is particularly dangerous to the developing brain in the pre- and neonatal periods. One postulated mechanism of its neurotoxicity is induction of inflammation. This study analyzed the effect of exposure of rat pups to Pb during periods of brain development on the concentrations of selected cytokines and prostanoids in the forebrain cortex, hippocampus and cerebellum. METHODS: Administration of 0.1% lead acetate (PbAc) in drinking water ad libitum, from the first day of gestation to postnatal day 21, resulted in blood Pb in rat pups reaching levels below the threshold considered safe for humans by the Centers for Disease Control and Prevention (10 µg/dL). Enzyme-linked immunosorbent assay (ELISA) method was used to determine the levels of interleukins IL-1ß, IL-6, transforming growth factor-ß (TGF-ß), prostaglandin E2 (PGE2) and thromboxane B2 (TXB2). Western blot and quantitative real-time PCR were used to determine the expression levels of cyclooxygenases COX-1 and COX-2. Finally, Western blot was used to determine the level of nuclear factor kappa B (NF-κB). RESULTS: In all studied brain structures (forebrain cortex, hippocampus and cerebellum), the administration of Pb caused a significant increase in all studied cytokines and prostanoids (IL-1ß, IL-6, TGF-ß, PGE2 and TXB2). The protein and mRNA expression of COX-1 and COX-2 increased in all studied brain structures, as did NF-κB expression. CONCLUSIONS: Chronic pre- and neonatal exposure to Pb induces neuroinflammation in the forebrain cortex, hippocampus and cerebellum of rat pups.