Agmatine ameliorates acetic acid-induced colitis in rats: involvement of nitrergic system.

Aim: The aim of the present study is to investigate the anti-inflammatory effect of agmatine through the inhibition of iNOS enzyme in acetic acid-induced rat colitis. Methods: Acute colitis was induced by administration of 2 mL of diluted acetic acid (4%) solution rectally. Two hours after colitis induction, animals were treated with normal saline, dexamethasone (2 mg/kg), agmatine (2, 5, 10 mg/kg), L-NAME (30 mg/kg), Aminoguanidine (20 mg/kg), agmatine (2 mg/kg) with L-NAME (30 mg/kg) and agmatine (2 mg/kg) with aminoguanidine (20 mg/kg) intraperitoneally and continued for 3 consecutive days. Assessment of macroscopic and microscopic damage was performed. MPO activity was evaluated by biochemical method. Furthermore, the tissue level of TNF-α was determined by ELISA and the expression level of iNOS protein was detected by immunohistochemistry (IHC). Results: Dexamethasone (2 mg/kg) and agmatine (5, 10 mg/kg) and subeffective doses of agmatine (2 mg/kg) with aminoguanidine (20 mg/kg) improved macroscopic and microscopic damage compared to acetic acid group (p < .001). In addition, these drugs reduced the activity of MPO (p < .001) and the level of TNF-α (p < .001) in colon tissue compared to acetic acid group. Furthermore, they decreased acetic acid-induced expression of iNOS protein in colon tissue (p < .01, p < .001). Conclusion: It is suggested that the anti-inflammatory activity of agmatine on acetic acid-induced rat colitis may involve the inhibition of iNOS enzyme.

Genetic Deletion or Pharmacological Inhibition of Soluble Epoxide Hydrolase Ameliorates Cardiac Ischemia/Reperfusion Injury by Attenuating NLRP3 Inflammasome Activation.

Activation of the nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome cascade has a role in the pathogenesis of ischemia/reperfusion (IR) injury. There is growing evidence indicating cytochrome p450 (CYP450)-derived metabolites of n-3 and n-6 polyunsaturated fatty acids (PUFAs) possess both adverse and protective effects in the heart. CYP-derived epoxy metabolites are rapidly hydrolyzed by the soluble epoxide hydrolase (sEH). The current study hypothesized that the cardioprotective effects of inhibiting sEH involves limiting activation of the NLRP3 inflammasome. Isolated hearts from young wild-type (WT) and sEH null mice were perfused in the Langendorff mode with either vehicle or the specific sEH inhibitor t-AUCB. Improved post-ischemic functional recovery and better mitochondrial respiration were observed in both sEH null hearts or WT hearts perfused with t-AUCB. Inhibition of sEH markedly attenuated the activation of the NLRP3 inflammasome complex and limited the mitochondrial localization of the fission protein dynamin-related protein-1 (Drp-1) triggered by IR injury. Cardioprotective effects stemming from the inhibition of sEH included preserved activities of both cytosolic thioredoxin (Trx)-1 and mitochondrial Trx-2 antioxidant enzymes. Together, these data demonstrate that inhibiting sEH imparts cardioprotection against IR injury via maintaining post-ischemic mitochondrial function and attenuating a detrimental innate inflammatory response.

Sumatriptan protects against myocardial ischaemia-reperfusion injury by inhibition of inflammation in rat model.

Ischemic heart disease is a leading cause of death on a global scale, placing major socio-economic burdens on health systems worldwide. Myocardial ischaemia and reperfusion (I/R)-induced tissue injury is associated with alteration in activity of inflammatory system and nitric oxide pathway. Sumatriptan, which is mainly used to relieve migraine headache, has recently been shown to exert anti-inflammatory properties. In this study, we aimed to assess the possible cardioprotective effect of sumatriptan in a rat model of I/R injury. Male Wistar rats were subjected to 30-min ligation of left anterior descending coronary artery and 120-min reperfusion. Animals were randomly divided into five groups: (1) Sham (2) I/R (3) I/R treated with sumatriptan (0.3 mg/kg i.p.) 20 min after induction of I/R rats, (4) GR127935 (a selective antagonist of 5-HT1B/D serotonin receptors; 0.3 mg/kg) 20 min after induction of I/R, and (5) GR127935 (0.3 mg/kg) 15 min before administration of sumatriptan. Post-infarct treatment with sumatriptan increased left ventricular function, which was damaged in I/R animal's heart. Sumatriptan (0.3 mg/kg) decreased lipid peroxidation, CK-MB and lactate dehydrogenase levels; tumor necrosis factor concentration; and Nf-Ò¡B' protein production. Treatment with sumatriptan significantly increased the endothelial nitric oxide synthase (eNOS) expression consequences nitric oxide metabolites' level in I/R rats. Also, injection of sumatriptan remarkably decreased myocardial tissue injury assessed by histopathological study. These findings suggest that sumatriptan may attenuate I/R injury via modulating the inflammatory responses and endothelial NOS activity. But therapeutic index of sumatriptan is narrow according to the result of this study.

Changes in the Left Ventricular Eicosanoid Profile in Human Dilated Cardiomyopathy.

Objective: Metabolites derived from N-3 and N-6 polyunsaturated fatty acids (PUFAs) have both beneficial and detrimental effects on the heart. However, contribution of these lipid mediators to dilated cardiomyopathy (DCM)-associated mitochondrial dysfunction remains unknown. This study aimed to characterize DCM-specific alterations in the PUFA metabolome in conjunction with cardiac mitochondrial quality in human explanted heart tissues. Methods: Left ventricular tissues obtained from non-failing control (NFC) or DCM explanted hearts, were assessed for N-3 and N-6 PUFA metabolite levels using LC-MS/MS. mRNA and protein expression of CYP2J2, CYP2C8 and epoxide hydrolase enzymes involved in N-3 and N-6 PUFA metabolism were quantified. Cardiac mitochondrial quality was assessed by transmission electron microscopy, measurement of respiratory chain complex activities and oxygen consumption (respiratory control ratio, RCR) during ADP-stimulated ATP production. Results: Formation of cardioprotective CYP-derived lipid mediators, epoxy fatty acids (EpFAs), and their corresponding diols were enhanced in DCM hearts. These findings were corroborated by increased expression of CYP2J2 and CYP2C8 enzymes, as well as microsomal and soluble epoxide hydrolase enzymes, suggesting enhanced metabolic flux and EpFA substrate turnover. DCM hearts demonstrated marked damage to mitochondrial ultrastructure and attenuated mitochondrial function. Incubation of fresh DCM cardiac fibers with the protective EpFA, 19,20-EDP, significantly improved mitochondrial function. Conclusions: The current study demonstrates that increased expressions of CYP-epoxygenase enzymes and epoxide hydrolases in the DCM heart correspond with enhanced PUFA-derived EpFA turnover. This is accompanied by severe mitochondrial functional impairment which can be rescued by the administration of exogenous EpFAs.

Mitochondrial Dysfunction and Inflammaging in Heart Failure: Novel Roles of CYP-Derived Epoxylipids.

Age-associated changes leading to a decline in cardiac structure and function contribute to the increased susceptibility and incidence of cardiovascular diseases (CVD) in elderly individuals. Indeed, age is considered a risk factor for heart failure and serves as an important predictor for poor prognosis in elderly individuals. Effects stemming from chronic, low-grade inflammation, inflammaging, are considered important determinants in cardiac health; however, our understanding of the mechanisms involved remains unresolved. A steady decline in mitochondrial function is recognized as an important biological consequence found in the aging heart which contributes to the development of heart failure. Dysfunctional mitochondria contribute to increased cellular stress and an innate immune response by activating the NLRP-3 inflammasomes, which have a role in inflammaging and age-related CVD pathogenesis. Emerging evidence suggests a protective role for CYP450 epoxygenase metabolites of N-3 and N-6 polyunsaturated fatty acids (PUFA), epoxylipids, which modulate various aspects of the immune system and protect mitochondria. In this article, we provide insight into the potential roles N-3 and N-6 PUFA have modulating mitochondria, inflammaging and heart failure.

Age and Sex Differences in Hearts of Soluble Epoxide Hydrolase Null Mice.

Biological aging is an inevitable part of life that has intrigued individuals for millennia. The progressive decline in biological systems impacts cardiac function and increases vulnerability to stress contributing to morbidity and mortality in aged individuals. Yet, our understanding of the molecular, biochemical and physiological mechanisms of aging as well as sex differences is limited. There is growing evidence indicating CYP450 epoxygenase-mediated metabolites of n-3 and n-6 polyunsaturated fatty acids (PUFAs) are active lipid mediators regulating cardiac homeostasis. These epoxy metabolites are rapidly hydrolyzed and inactivated by the soluble epoxide hydrolase (sEH). The current study characterized cardiac function in young and aged sEH null mice compared to the corresponding wild-type (WT) mice. All aged mice had significantly increased cardiac hypertrophy, except in aged female sEH null mice. Cardiac function as assessed by echocardiography demonstrated a marked decline in aged WT mice, notably significant decreases in ejection fraction and fractional shortening in both sexes. Interestingly, aged female sEH null mice had preserved systolic function, while aged male sEH null mice had preserved diastolic function compared to aged WT mice. Assessment of cardiac mitochondria demonstrated an increased expression of acetyl Mn-SOD levels that correlated with decreased Sirt-3 activity in aged WT males and females. Conversely, aged sEH null mice had preserved Sirt-3 activity and better mitochondrial ultrastructure compared to WT mice. Consistent with these changes, the activity level of SOD significantly decreased in WT animals but was preserved in aged sEH null animals. Markers of oxidative stress demonstrated age-related increase in protein carbonyl levels in WT and sEH null male mice. Together, these data highlight novel cardiac phenotypes from sEH null mice demonstrating a sexual dimorphic pattern of aging in the heart.

Insights into the cardioprotective properties of n-3 PUFAs against ischemic heart disease via modulation of the innate immune system.

Ischemic heart disease (IHD) is a major cause of cardiovascular morbidity and mortality worldwide, which is characterized by an imbalance between cardiac oxygen supply and demand predominantly due to obstruction of coronary arteries. Activation of the innate immune system and the consequent inflammatory response plays a role in the pathogenesis of IHD. Where an excessive inflammatory response may contribute to adverse cardiac remodeling and fibrosis, making inflammation an important therapeutic target for improving outcomes of IHD. While there are many discrepancies in the literature, evidence from both bench and clinical research demonstrate important effects of n-3 polyunsaturated fatty acids (n-3 PUFA), eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA), toward IHD. N-3 PUFAs, and their metabolites, have been demonstrated to modulate various components of the immune system, including regulation of chemokines and cytokines, leukocyte chemotaxis and inflammasome formation. In this article, we provide an overview of the role the innate immune system has in IHD and focus on the immunomodulatory effects of n-3 PUFAs and their biologically active metabolites.

The Possible Role of Nitric Oxide Pathway in Pentylenetetrazole Preconditioning Against Seizure in Mice.

Preconditioning is defined as an induction of adaptive response in organs against lethal stimulation provoked by subsequent mild sublethal stress. Several chemical agents have been demonstrated to cause brain tolerance through preconditioning. The aim of the present study is to test the hypothesis that preconditioning with pentylenetetrazole (PTZ) may have protective effect against seizure induced by i.v. infusion of PTZ. Mice were preconditioned by low-dose administration of PTZ (25 mg/kg) for 5 consecutive days, and the threshold of seizure elicited by i.v. infusion of PTZ was measured. To investigate the possible role of nitric oxide, NOS inhibitor enzymes, including L-NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) (10 mg/kg), aminoguanidine (AG) (50 mg/kg), 7-nitroindazole (7-NI) (15 mg/kg), and L-arginine (L-arg) (60 mg/kg), were administered concomitantly with PTZ in both acute and chronic phases. Determination of seizure threshold revealed significant enhancement after preconditioning with low dose of PTZ. While the protective effect of PTZ preconditioning was enhanced after the administration of L-arg, it was reversed following administration of L-NAME and 7NI, suggesting the involvement of nitric oxide pathway as an underlying mechanism of PTZ-induced preconditioning. Preconditioning with PTZ led to brain tolerance and adaptive response in animal model of PTZ-induced seizure. This effect is in part due to the involvement of nitric oxide pathway.

Initial Results of a Prospective Study and Identification of New Strategies to Increase Traceability of Plasma-derived Medicines.

Plasma medicine is an innovative and emerging field used in a broad range of medical conditions. The present study focused on consumption and documentation pattern of plasma-derived medicines in a teaching hospital. A two-step study was conducted from October to December 2015. During the first phase, the patient records receiving plasma-derived medicines including Coagulation Factor VIII, IX, Prothrombin Complex Concentrate, Factor VIII/Von Wilberand Complex, Anti-Hepatitis B Immunoglobulin, Intravenous Immunoglobulin, Anti-Tetanus Immunoglobulin, and Albumin were checked to assess recording details of these medications at the time of administration. Adverse events reported with the mentioned products were examined from traceability viewpoint. The second step concentrated on practical strategies to improve documentation status of plasma-derived medicines in the hospital. We proposed national guideline as the first strategy and a new barcoding system to track and identify drug information of plasma medicines. Of the expected drug information, only generic name, dosage from, and strength were recorded after administration. Post-marketing safety surveillance of the plasma products was poor similarly. Unavailability of suitable instructions was the main reason for documentation deficiency. A guideline was designed and implemented to inform healthcare professionals about essentials of appropriate documentation for plasma-derived medicines. Updated results of the ongoing phase will be submitted soon. Our survey highlights the importance of documentation as a key component of plasma-derived medicines surveillance within the hospitals.

Deficiency of Soluble Epoxide Hydrolase Protects Cardiac Function Impaired by LPS-Induced Acute Inflammation.

Lipopolysaccharide (LPS) is a bacterial wall endotoxin producing many pathophysiological conditions including myocardial inflammation leading to cardiotoxicity. Linoleic acid (18:2n6, LA) is an essential n-6 PUFA which is converted to arachidonic acid (20:4n6, AA) by desaturation and elongation via enzyme systems within the body. Biological transformation of PUFA through CYP-mediated hydroxylation, epoxidation, and allylic oxidation produces lipid mediators, which may be subsequently hydrolyzed to corresponding diol metabolites by soluble epoxide hydrolase (sEH). In the current study, we investigate whether inhibition of sEH, which alters the PUFA metabolite profile, can influence LPS induced cardiotoxicity and mitochondrial function. Our data demonstrate that deletion of soluble epoxide hydrolase provides protective effects against LPS-induced cardiotoxicity by maintaining mitochondrial function. There was a marked alteration in the cardiac metabolite profile with notable increases in sEH-derived vicinal diols, 9,10- and 12,13-dihydroxyoctadecenoic acid (DiHOME) in WT hearts following LPS administration, which was absent in sEH null mice. We found that DiHOMEs triggered pronounced mitochondrial structural abnormalities, which also contributed to the development of extensive mitochondrial dysfunction in cardiac cells. Accumulation of DiHOMEs may represent an intermediate mechanism through which LPS-induced acute inflammation triggers deleterious alterations in the myocardium in vivo and cardiac cells in vitro. This study reveals novel research exploring the contribution of DiHOMEs in the progression of adverse inflammatory responses toward cardiac function in vitro and in vivo.

Acetyl-L-Carnitine Attenuates Arsenic-Induced Oxidative Stress and Hippocampal Mitochondrial Dysfunction.

Augmentation of mitochondrial oxidative stress through activating a series of deadly events has implicated as the main culprit of arsenic toxicity and therapeutic approaches based on improving mitochondrial function hold a great promise for attenuating the arsenic-induced toxicity. Acetyl-L-carnitine (ALC) through balancing the coenzyme A (CoA)/acyl-CoA ratio plays an important role in mitochondrial metabolism and thereby can help protect hippocampal neurons from oxidative damage. In the present study, we aimed to explore the effect of arsenic interactions on the mitochondrial function in the hippocampus of rats. Rats were randomly divided into five groups of control (distilled water), sodium arsenite (NaAsO2, 20 mg/kg), and co-treatment of NaAsO2 with various doses of ALC in three groups (100, 200, 300 mg/kg) and were treated orally for 21 consecutive days. Our results point out that arsenic exposure caused oxidative stress in rats' hippocampus, which led to the reactive oxygen species (ROS) generation, mitochondrial swelling, the collapse of the mitochondrial membrane potential, and release of cytochrome c. It also altered Bcl-2/Bax expression ratio and increased caspase-3 and caspase-9 activities. Furthermore, arsenic exposure via activation of NF-κB and microglia increased inflammation. ALC could concentration-dependently counteract the arsenic-induced oxidative stress, modulate the antioxidant defense capacity, and improve mitochondrial functions. In addition, ALC decreased the expression of both death-associated proteins and of inflammatory markers. These findings indicate that ALC improved the arsenic-induced hippocampal mitochondrial dysfunction which underlines the importance of ALC in providing a possible therapeutic strategy for the prevention of arsenic-induced neurodegeneration.

Ellagic acid confers protection against gentamicin-induced oxidative damage, mitochondrial dysfunction and apoptosis-related nephrotoxicity.

OBJECTIVES: The aim of this study was to investigate the possible protective effect of ellagic acid (EA) against gentamicin (GEN)-induced nephrotoxicity using biochemical, molecular and histopathological approaches. METHODS: Rats (n = 24) were divided into four groups: control, GEN (100 mg/kg, i.p.), EA (10 mg/kg, p.o.) and GEN plus EA. The regimes were administered for 10 successive days. 24 h after last treatment, kidney and blood samples were collected. KEY FINDINGS: Ellagic acid treatment significantly reduced plasma creatinine and urea levels, which were initially increased due to GEN administration. Also, EA significantly ameliorated oxidative stress markers including lipid peroxidation, catalase (CAT) and superoxide dismutase (SOD) enzyme activity as well as glutathione (GSH) content in kidney tissue. Activation of caspase-3 and increase in the ratio of Bcl-2/Bax expression observed in GEN-treated group were significantly ameliorated by EA treatment. EA also protected GEN-induced mitochondrial damages as indicated by decreasing the mitochondrial ROS content, preventing of mitochondrial membrane potential (MMP) loss, reducing mitochondrial swelling and decreasing cytochrome c release. In addition, histopathological findings revealed that EA ameliorates GEN-induced kidney injury. CONCLUSIONS: Our findings suggest that EA treatment attenuates GEN-induced nephrotoxicity, which may be ascribed to its antioxidant and anti-apoptotic properties.