Increase In Myeloperoxidase Activity Research Articles

ACTION OF HYDROGEN SULFIDE DONORS ON NITROSO-OXIDATIVE PROCESSES IN SMALL INTESTINE OF RATS WITH METHOTREXATE-INDUCED ENTEROPATHY

Introduction. Medication-induced enteropathy plays an important part among factors leading to the development of small intestinal injury. There are some evidences indicating a potential preventive action of hydrogen sulfide (H2S) donors against drug-induced enteropathies based on that fact that the use of the most of enterotoxic medications including anti-tumor drugs leads to the suppression of this gaseous mediator production. 
 The aim of the study – to compare the action of H2S donors in small intestine of rats on parameters of NO-synthase system and oxidative stress under condition of methotrexate-induced enteropathy. 
 Research Methods. The experimental procedures were carried out on rats which on the background of methotrexate-induced enteropathy received H2S donors NaHS (1 and 10 mg/kg) and L-cysteine. Following biochemical parameters were measured in small intestinal mucosa: activity of NO-synthases, myeloperoxidase, superoxide dismutase and catalase; concentrations of NOx (nitrite/nitrate) and malonic dialdehyde. H2S concentration was determined in blood serum.
 Results and Discussion. Administration of methotrexate didn’t cause any visible changes of small intestine surface, however led to serious biochemical changes. NO concentration increased as a result of iNOS activation (more than fivefold (p≤0.01). Simultaneously concentration of H2S decreased in blood serum. Administration of H2.S donors practically returned these parameters to their normal value. Methotrexate-induced enteropathy caused the increase of myeloperoxidase activity by 66 %, p≤0.01, indicating of inflammatory process formation and activation of lipid peroxidation. Administration of NaHS didn’t cause any serious changes in myeloperoxidase activity, however increased SOD activity and practically retuned it to its norm.
 Conclusions. Nirtoso-oxidative stress plays the key role in enteropathy formation resulted in methotrexate administration. H2S donors modulate parameters of NO-synthase system and activity of SOD.

Anti-inflammatory action of an alkaloid, fraction and extract from Alchornea glandulosa in mice

Ethnopharmacological relevanceAlchornea glandulosa (Euphorbiaceae) has traditionally been used in medicine for treating immune-mediated inflammatory diseases. Aim of studyThis work aimed to evaluate the anti-inflammatory effects of a methanolic extract of leaves from A. glandulosa (MEAG), as well as the ethyl acetate fraction (EAFAG) and isolated compound guanidine alkaloid N-1, N-2, N-3-triisopentenylguanidine (AG-1), in experimental in vivo models of inflammation in mice. We also investigated this extract's phenols, flavonoids and flavonol compounds. Materials and methodsMEAG (extracted by maceration with methanol), EAFAG (fraction resulting from the partition of the methanolic extract with ethyl acetate) and AG-1 (alkaloid isolated by chromatographic methods) were analysed. MEAG and EAFAG were analysed by HPLC/DAD. The effects of MEAG (30, 100 and 300 mg/kg), EAFAG (30, 100 and 300 mg/kg) and AG-1 (5 and 30 mg/kg) were studied in the following experimental mouse models: paw oedema and myeloperoxidase (MPO) activity, croton-oil-induced ear oedema, leukocyte migration in a pleurisy model induced by carrageenan and zymosan induction of joint inflammation. ResultsMEAG and EAFAG were analysed by LC/DAD, and phenolic acids (gallic acid and caffeic acid) and flavonoids (myricetin-3-O-α-rhamnopyranoside and quercetin) were detected. MEAG, EAFAG and AG-1 were used in the carrageenan-induced paw oedema model and showed maximum inhibitions of 60.10% (MEAG, 2 h, 300 mg/kg) and 66.21% (EAFAG, 2 h, 300 mg/kg). AG-1 at 5 mg/kg showed significant inhibition, ranging from 60.92% to 63.13%, at all evaluated times, and the 30 mg/kg dose showed inhibition of 42.12% (1 h) and 40.36% (2 h). MEAG (37%, 46.1% and 68.11%) and EAFAG (31%, 42.21% and 48.93%), at doses of 30, 100 and 300 mg/kg, respectively, significantly reduced the increase in MPO activity, and AG-1 (5 and 30 mg/kg) showed inhibition of 64.62% and 65.12%, respectively. In the pleurisy model, MEAG (300 mg/kg), EAFAG (300 mg/kg) and AG-1 (30 mg/kg) significantly reduced the migration of total leukocytes with maximal inhibition of 80.90%, 83.17% and 89.39%, respectively. In the croton oil model, pretreatment with MEAG (0.1, 0.3 and 1 mg/ear) increased the diameter of the right ear (30.32%, 48.87% and 53.09%, respectively). Finally, MEAG (100 and 300 mg/kg; 33.11% and 56.03%) and EAFAG (100 and 300 mg/kg; 36.89% and 50.53%) reduced zymosan-induced oedema formation. ConclusionsTo the best of our knowledge, these results are the first to demonstrate that A. glandulosa exhibits oral and topical anti-inflammatory activity. This study detected alkaloid and phenol/polyphenolic compounds in A. glandulosa, which may help to explain the ethnobotanical use of this plant in traditional medicine in Brazil to treat immune-mediated inflammatory diseases.

Diphenyl diselenide abrogates brain oxidative injury and neurobehavioural deficits associated with pesticide chlorpyrifos exposure in rats

Exposure to pesticide chlorpyrifos (CPF) is associated with neurodevelopmental toxicity both in humans and animals. Diphenyl diselenide (DPDS) is a simple synthetic organoselenium well reported to possess antioxidant, anti-inflammatory and neuroprotective effects. However, there is paucity of information on the beneficial effects of DPDS on CPF-mediated brain injury and neurobehavioural deficits. The present study investigated the neuroprotective mechanism of DPDS in rats sub-chronically treated with CPF alone at 5 mg/kg body weight or orally co-treated with DPDS at 2.5 and 5 mg/kg body weight for 35 consecutive days. Endpoint analyses using video-tracking software in a novel environment revealed that co-treatment with DPDS significantly (p < 0.05) protected against CPF-mediated locomotor and motor deficits precisely the decrease in maximum speed, total distance travelled, body rotation, absolute turn angle, forelimb grip strength as well as the increase in negative geotaxis and incidence of fecal pellets. The enhancement in the neurobehavioral activities of rats co-treated with DPDS was verified by track plot analyses. Besides, DPDS assuaged CPF-induced decrease in acetylcholinesterase and antioxidant enzymes activities and the increase in myeloperoxidase activity and lipid peroxidation level in the mid-brain, cerebral cortex and cerebellum of the rats. Histologically, DPDS co-treatment abrogated CPF-mediated neuronal degeneration in the cerebral cortex, dentate gyrus and cornu ammonis3 in the treated rats. In conclusion, the neuroprotective mechanisms of DPDS is related to the prevention of oxidative stress, enhancement of redox status and acetylcholinesterase activity in brain regions of the rats. DPDS may be a promising chemotherapeutic agent against brain injury resulting from CPF exposure.

The exogenous administration of CB2 specific agonist, GW405833, inhibits inflammation by reducing cytokine production and oxidative stress.

The present study aimed to investigate the role of cannabinoid 2 (CB2) receptors in a rat model of acute inflammation. Therefore, the potential of anti-inflammatory effects of CB2 receptor agonist (GW405833), CB2 receptor antagonist (AM630), and diclofenac, were investigated in carrageenan induced paw oedema in rats: as were assessed by measuring paw oedema; myeloperoxidase (MPO) activity in paw tissue; malondialdehyde (MDA) concentration; glutathione (GSH) level in paw tissue for oxidant/antioxidant balance; cytokine (interleukin-1β, IL-1β; tumour necrosis factor-α, TNF-α) levels in serum; histopathology of paw tissue for inflammatory cell accumulations. The results showed that GW405833 or diclofenac significantly reduced carrageenan-induced paw oedema. GW405833 also inhibited the increase of MPO activity, the recruitment of total leukocytes and neutrophils, and MDA concentration during carrageenan-induced acute inflammation, along with reversed nearly to the normal levels the increased of TNF-α, and IL-1β in serum. AM630 did not affect inflammation alone however clearly reversed the effects of agonist when co-administered. The mechanism of GW405833's suppression of inflammation is supported by these results, which are achieved by the inhibition of neutrophil migration, which regulates the reduction of oxidative stress, TNF-α and IL-1β levels. Finally, the activation of CB2 receptor, by selective agonist, has a major role in peripheral inflammation, and in the near future, targeting the peripheral cannabinoid system as a promising alternative to treat inflammation diseases may be considered a novel pharmacologic approach.

Taurine Ameliorates Thyroid Hypofunction and Renal Injury in L-NAME-Induced Hypertensive Rats.

There is a growing global interest in hypertension due to its associated complications including renal dysfunction in patients. The thyroid system reportedly regulates renal function in both animal and human. The present study investigated the therapeutic efficacy of taurine on renal and thyroid dysfunctions in hypertensive rats. Hypertension was induced by oral administration of nitric oxide synthase inhibitor, N-nitro L-arginine-methyl-ester (L-NAME), at 40 mg/kg body weight to the male Wistar rats for 14 consecutive days. The hypertensive rats were subsequently treated with either taurine (100 and 200 mg/kg) or reference drug atenolol (10 mg/kg) for another 14 consecutive days. Hypertensive rats showed renal damage evidenced by elevated plasma creatinine and urea levels when compared with normotensive control rats. Furthermore, L-NAME-induced hypertensive rats showed decreased circulatory concentrations of thyroid stimulating hormone, thyroxine, triiodothyronine and the ratio of triiodothyronine to thyroxine. The marked decrease in the renal antioxidant enzyme activities and nitric oxide level was accompanied by significant increase in myeloperoxidase activity and biomarkers of oxidative stress in hypertensive rats. Histological examination of kidneys from hypertensive rats revealed congestion of blood vessels, hemorrhagic lesion and disorganized glomerular structure. However, treatment with taurine or atenolol significantly reversed the suppression of thyroid function, ameliorated renal oxidative stress and histopathological lesions in L-NAME-induced hypertensive rats. Taurine may be a useful chemotherapeutic supplement in enhancing renal and thyroid functions in hypertensive patients.

Abstract 3139: Innate immune cells expressing myeloperoxidase directly inhibit tumor NF-κB transcriptional activation during tumor initiation

Abstract Neutrophils are considered the primary defenders of the innate immune system. However, in the context of cancer, the role of neutrophils is complex where they can be host protecting or pro-tumorigenic. For example, myeloperoxidase (MPO), the major protein in neutrophils, produces reactive oxygen species (ROS); ROS can lead to tumor regression from cell cytotoxicity or cause DNA-damage resulting in genetic mutations triggering tumor initiation/progression. Using the melanoma cell lines, B16F10, stably expressing a NF-κB-driven Firefly luciferase (FLuc) reporter or an IκBα-FLuc fusion reporter gene, co-culture studies in vitro with bone marrow-isolated-neutrophils from C57BL/6 animals demonstrated inhibition of NF-κB transcriptional activation in a MPO activity-dependent manner. Using bioluminescence imaging with luminol, neutrophils pre-stimulated with 50uM phorbol myristate acetate (PMA) demonstrated an increase in MPO activity by 20.3 ± 2.4 fold over unstimulated neutrophils. When B16F10 reporter cells were co-cultured with PMA pre-stimulated neutrophils, we observed inhibition of IκBα degradation by 33.0% ± 11.9%, resulting in a decrease in NF-κB transcriptional activation compared to co-culture studies with unstimulated neutrophils. The role of neutrophils during B16F10 tumor initiation and growth was compared in C57BL/6 and syngeneic MPO-null mice. Utilizing intravital imaging with skinfold window chamber animal models and imaging reporters, we evaluated in real-time, the recruitment of MPO-expressing cells and tumor NF-κB activation in vivo. Mean NF-κB transcriptional activation within the tumor compartment in MPO-null mice was 42.2% ± 1.6% greater compared to wild type animals. Tumor growth and survival curves demonstrated that B16F10 tumors grew slower in wild-type animals (mean survival of 26.8 days) compared to MPO-null animals (mean survival time of 23.4 days). Using an MPO inhibitor, 4-aminobenzoic acid hydrazide (4-ABAH), we pharmacologically mimicked the MPO-null phenotype in C57BL/6 animals (40mg/kg intraperitoneal injection twice daily). B16F10 tumors grew slower in C57BL/6 animals treated with 4-ABAH (mean survival of 23.8 days) compared to wild type animals. Taken together, these data demonstrated that MPO-expressing cells contribute to host protection during tumor initiation in a NF-κB-dependent manner. Citation Format: Tracy W. Liu, Seth T. Gammon, David Piwnica-Worms. Innate immune cells expressing myeloperoxidase directly inhibit tumor NF-κB transcriptional activation during tumor initiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3139.

Dynamic Proteome Alteration and Functional Modulation of Human Saliva Induced by Dietary Chemosensory Stimuli.

Saliva flow measurements and SDS-PAGE separation of human whole saliva freshly collected after oral stimulation with citric acid (sour), aspartame (sweet), iso-α-acids (bitter), mono sodium l-glutamate (umami), NaCl (salty), 6-gingerol (pungent), hydroxy-α-sanshool (tingling), and hydroxy-β-sanshool (numbing), followed by tryptic digestion, nano-HPLC-MS/MS, and label-free protein quantitation demonstrated a stimulus- and time-dependent influence of the dietary chemosensates on salivation and the salivary proteome composition. Gene ontology enrichment analysis showed evidence for stimulus-induced alterations of the saliva proteome to boot an efficient molecular defense network of the oral cavity, e.g., 6-gingerol increased salivary lactoperoxidase activity, catalyzing the oxidation of thiocyanate to produce the antimicrobial and antifungal hypothiocyanate, from 0.37 ± 0.02 to 0.91 ± 0.05 mU/mL 45 s after stimulation. In comparison, oral citric acid stimulation induced an increase of myeloperoxidase activity, catalyzing the chloride oxidation to generate antimicrobial hypochloride in saliva, from 0.24 ± 0.04 to 0.70 ± 0.1 mU/mL as well as an increase of salivary levels of lysozyme, exhibiting antimicrobial activity on Gram-positive bacteria, from 6.0-10 to 100-150 μg/mL. Finally, microbial growth experiments clearly demonstrated for the first time that the increase of the salivary lysozyme abundance upon oral citric acid stimulation translates into an enhanced biological function, that is an almost complete growth inhibition of the two lysozyme-sensitive Gram-positive bacteria tested.

Inhibitive Effects of Quercetin on Myeloperoxidase-Dependent Hypochlorous Acid Formation and Vascular Endothelial Injury

Myeloperoxidase (MPO) from activated neutrophils plays important roles in multiple human inflammatory diseases by catalyzing the formation of powerful oxidant hypochlorous acid (HOCl). As a major flavonoid in the human diet, quercetin has been suggested to act as antioxidant and anti-inflammatory agent in vitro and in vivo. In this study, we showed that quercetin inhibited MPO-mediated HOCl formation (75.0 ± 6.2% for 10 μM quercetin versus 100 ± 5.2% for control group, P < 0.01) and cytotoxicity to endothelial cells in vitro, while this flavonoid was nontoxic to endothelial cell cultures ( P > 0.05, all cases). Moreover, quercetin inhibited HOCl generation by stimulated neutrophils (a rich source of MPO) and protected endothelial cells from neutrophils-induced injury. Furthermore, quercetin could inhibit HOCl-induced endothelial dysfunction such as loss of cell viability, and decrease of nitric oxide formation in endothelial cells ( P < 0.05, all cases). Consistent with these in vitro data, quercetin attenuated lipopolysaccharide-induced endothelial dysfunction and increase of MPO activity in mouse aortas, while this flavonoid could protect against HOCl-mediated endothelial dysfunction in isolated aortas ( P < 0.05). Therefore, it was proposed that quercetin attenuated endothelial injury in inflammatory vasculature via inhibition of vascular-bound MPO-mediated HOCl formation or scavenging of HOCl. These data indicate that quercetin is a nontoxic inhibitor of MPO activity and MPO/neutrophils-induced cytotoxicity in endothelial cells and may be useful for targeting MPO-dependent vascular disease and inflammation.

Sex influences in behavior and brain inflammatory and oxidative alterations in mice submitted to lipopolysaccharide-induced inflammatory model of depression

Peripheral inflammation induced by lipopolysaccharide (LPS) causes a behavioral syndrome with translational relevance for depression. This mental disorder is twice more frequent among women. Despite this, the majority of experimental studies investigating the neurobiological effects of inflammatory models of depression have been performed in males. Here, we sought to determine sex influences in behavioral and oxidative changes in brain regions implicated in the pathophysiology of mood disorders (hypothalamus, hippocampus and prefrontal cortex - PFC) in adult mice 24 h post LPS challenge. Myeloperoxidase (MPO) activity and interleukin (IL)-1β levels were measured as parameters of active inflammation, while reduced glutathione (GSH) and lipid peroxidation as parameters of oxidative imbalance. We observed that male mice presented behavioral despair, while females anxiety-like alterations. Both sexes were vulnerable to LPS-induced anhedonia. Both sexes presented increased MPO activity in the PFC, while male only in the hippocampus. IL-1β increased in the PFC and hypothalamus of animals of both sexes, while in the hippocampus a relative increase of this cytokine in males compared to females was detected. GSH levels were decreased in all brain areas investigated in animals of both sexes, while increased lipid peroxidation was observed in the hypothalamus of females and in the hippocampus of males after LPS exposure. Therefore, the present study gives additional evidence of sex influence in LPS-induced behavioral alterations and, for the first time, in the oxidative changes in brain areas relevant for mood regulation.

Early signs of colonic inflammation, intestinal dysfunction, and olfactory impairments in the rotenone-induced mouse model of Parkinson's disease.

The factors that trigger the pathophysiology of Parkinson's disease (PD) are unknown. However, it is suggested that environmental factors, such as exposure to pesticides, play an important role, in addition to genetic predisposition and aging. Early signs of PD can appear in the gastrointestinal (GI) tract and in the olfactory system, preceding the onset of motor impairments by many years. The present study assessed the effects of oral rotenone administration (30 mg/kg) in inducing GI and olfactory dysfunctions associated with PD in mice. Here we show that rotenone transiently increased myeloperoxidase activity within 24 h of administration. Leucocyte infiltration in the colon, associated with histological damage and disrupted GI motility, were observed following treatment with rotenone for 7 days. Moreover, 7 days of treatment with rotenone disrupted olfactory discrimination in mice without affecting social recognition ability. The presence of specific deficits in olfactory function occurred with a concomitant decrease in tyrosine hydroxylase-positive neurons and an increase in serotonin (5-hydroxytryptamine) turnover in the olfactory bulb. These findings suggest that in Swiss mice, exposure to rotenone induces GI and olfactory dysfunction involving immunological and neurotransmitter alterations, similar to early signs of PD. This provides further evidence for the involvement of the gut-brain axis in PD.

Levels of Nitric Oxide Metabolites and Myeloperoxidase in Subjects with Type 2 Diabetes Mellitus on Metformin Therapy .

Endothelial dysfunction is involved in the pathogenesis of insulin resistance, diabetes mellitus type 2, diabetic complications and preceded clinical manifestation of cardiovascular complications. Increased myeloperoxidase activity has been linked to a number of pathologies with compelling evidence in initiation and progression of inflammatory events. The aim of this study was to compare concentrations of metabolite nitric oxide and myeloperoxidase in the plasma of diabetes mellitus type 2 patients on metformin therapy, without clinical signs of cardiovascular disease and healthy subjects, as well as evaluation of concentrations of analytes in association with glycemic control. Forty four study subjects with diabetes mellitus type 2 and thirty healthy subjects were included in this study. The concentration of myeloperoxidase was determined by enzyme-linked immunosorbent assay, the concentration of nitrate and nitrite with high performance liquid chromatography method. Student's t test, Mann-Whitney U test, Chi-square test and Fisher's exact test were used for statistical analysis. The mean concentration of myeloperoxidase was significantly higher in the diabetic group compared to the control group (16.2±4.9 vs. 3.7±1.8; P<0.001).The nitrite concentration was comparable in both groups while the concentration of nitrate was significantly higher in the diabetic group (41.2 [42.9] vs 31.9 [23]; P=0.017). In this study, plasma myeloperoxidase (Spearman's rho=0.421; P=0.004) and nitrate concentration was significantly positively associated with the HbA1c levels while nitrate concentration (Spearman's rho=- 0.308; P=0.047) were was significantly positively negatively associated with the HbA1c levels. Concertation of MPO and nitric oxide were significantly increased in a T2DM subject even when on metformin therapy. However, increased concentration of NO strongly correlates with lower levels of HbA1c showing a postive effect of a gylcemic control on endothelial dysfuction. Increased concentrations of NO3- in T2DM subject compared to control, indicates the variety of NO pathways that should be taken into consideration win relation to endothelial function.

Antioxidant and anti-inflammatory effect of plumieride in dextran sulfate sodium-induced colitis in mice

This study aimed to investigate the potential effect of plumieride, an iridoid glycoside isolated from Alamanda cathartica L. flowers, against dextran sulfate sodium (DSS)-induced colitis in mice. Colitis was induced in female swiss mice by adding DSS 3% to the drinking water. The animals were treated with vehicle (water), 5-aminosalicylic acid (100 mg/kg) or plumieride (10, 30 and 100 mg/kg) once a day, during 7 days. The body weight progression and the disease activity index was evaluated daily. On the eighth day, colons were collected for the measurement of the size, histological, histochemical, biochemical and inflammatory analysis. The cytotoxicity of plumieride on intestinal epithelial cell (IEC-6 cell line) was also evaluated. Plumieride, at dose of 100 mg/kg, significantly attenuated the mice weight loss, showed lower score in the disease activity index, diminished the colon shortening, improved the histological damage and avoided mucosa intestinal mucus depletion when compared with vehicle-treated only group. Moreover, plumieride was able to reduce the amount of colonic lipid hydroperoxides, while augmented reduced glutathione levels and superoxide dismutase activity. Although DSS intake stimulated an increase in myeloperoxidase activity and in tumor necrosis factor content on the colon tissue of the vehicle-treated group, the colons obtained from mice treated with plumieride did not present any of these changes. Taking together, the results of the present study disclose that plumieride exhibited a significant efficacy in attenuating the parameters of experimental ulcerative colitis, which may be mediated by an antioxidant and anti-inflammatory effect.

Carob extract attenuates brain and lung injury in rats exposed to waterpipe smoke

Waterpipe smoking is one of the most popular methods of tobacco consumption world-wide which induces many health problems. In the present study; we evaluated the toxic effects of waterpipe smoke by using amiodarone as a model for lung toxicity in adult male albino rats. Also, the protective and therapeutic effects of carob aqueous extract on these toxicity which produced by daily exposure to waterpipe smoke for 8 weeks. The amiodarone gavage significantly increased serotonin content in brainstem and cerebral cortex after 8 and 2 weeks respectively and dopamine content at most of time intervals. Moreover, waterpipe smoke exposure induced a significant decrease in dopamine content after 2 weeks in brainstem and in serotonin content after 4, 6 weeks in brainstem and 6, 8 weeks in cerebral cortex. While, increment in dopamine content after 4, 6 weeks in brainstem and 6, 8 weeks in cerebral cortex may be due to increase its synthesis which strengthens the coughing reflex. Amiodarone gavage and waterpipe smoke exposure induced a significant increase in myeloperoxidase activity, hydroxyproline content and nitric oxide level in lung; while, catalase activity was decreased significantly. Consequently, waterpipe smoke exposure for long time caused serious harmful effects on brain and lung nearly like amiodarone. Carob extract pre-and post-treatment has the ability to protect and ameliorate these effects due to its antioxidant and anti-coughing effects. So, further studies are necessary to elucidate the mechanism of action of the effective components in the extract.

Influence of the type of congenital heart defects on epithelial lining fluid composition in infants undergoing cardiac surgery with cardiopulmonary bypass.

BackgroundIn children with congenital heart disease (CHD), altered pulmonary circulation compromises gas exchange. Moreover, pulmonary dysfunction is a complication of cardiac surgery with cardiopulmonary bypass (CPB). No data are available on the effect of different CHDs on lung injury. The aim of this study was to analyze epithelial lining fluid (ELF) surfactant composition in children with CHD.MethodsTracheal aspirates (TAs) from 72 CHD children (age 2.9 (0.4-5.7) months) were obtained before and after CPB. We measured ELF phospholipids, surfactant proteins A and B (SP-A, SP-B), albumin, and myeloperoxidase activity. TAs from 12 infants (age 1.0 (0.9-2.9) months) with normal heart/lung served as controls.ResultsHeart defects were transposition of great arteries (19), tetralogy of Fallot (TOF, 20), atrial/ventricular septal defect (ASD/VSD, 22), and hypoplastic left heart syndrome (11). Increased levels of ELF SP-B were found in all defects, increased myeloperoxidase activity in all except the TOF, and increased levels of ELF albumin and SP-A only in ASD/VSD patients. Postoperatively, ELF findings remained unchanged except for a further increase in myeloperoxidase activity.ConclusionELF composition has distinctive patterns in different CHD. We speculate that a better knowledge of the ELF biochemical changes may help to prevent respiratory complications.

Maternal hypertension and feto-placental growth restriction is reversed by sildenafil: Evidence of independent effects of circulating nitric oxide levels

Sildenafil has shown nitric oxide (NO)-independent pleiotropic effects, however the mechanisms involved are unclear. We investigated the protective effects of sildenafil against hypertension in pregnancy and feto-placental growth restriction induced by NO inhibition, and if sodium nitrite-derived NO formation influences sildenafil effects. We evaluated the plasmatic levels of NO metabolites, cyclic guanosine monophosphate (cGMP), oxidative stress and myeloperoxidase, which are involved in endothelial dysfunction during hypertension in pregnancy. Also, we performed in vitro experiments to examine cell viability and NO synthesis in human umbilical vein endothelial cells (HUVECs) cultures incubated with plasma from healthy or hypertensive pregnant rats treated (or not) with both drugs, either alone or in association. Sildenafil blunted hypertension in pregnancy and protected against feto-placental growth restriction induced by NO inhibition and these effects of sildenafil alone were similar to those presented by its association with sodium nitrite. Protective effects of sildenafil were observed even with low plasmatic NO levels and were not followed by increases in cGMP levels. Also, sildenafil, but not sodium nitrite, blunted the increases in myeloperoxidase activity. Both drugs (isolated or in association) presented antioxidant effects. Plasma from hypertensive pregnant rats treated with sildenafil, but not sodium nitrite alone, increased the viability of HUVECs. NO synthesis in HUVECs cultures was increased with plasma from rats treated with both drugs. We conclude that sildenafil effects are not dependent of circulating NO levels in hypertension and feto-placental growth restriction. These findings may reflect a protection against myeloperoxidase and pro-oxidant activation in hypertension in pregnancy.

Dietary Extra-Virgin Olive Oil Polyphenols Do Not Attenuate Colon Inflammation in Transgenic HLAB-27 Rats but Exert Hypocholesterolemic Effects through the Modulation of HMGCR and PPAR-α Gene Expression in the Liver

Background: Human studies have demonstrated that olive oil phenolic compounds reduce inflammatory markers associated with chronic diseases. Objectives: To explore the anti-inflammatory effects of extra-virgin olive oil polyphenols in an experimental model of inflammatory bowel disease (IBD). Methods: HLA-B27 transgenic rats were fed an AIN-76 diet containing 10% corn oil (CO) or extra-virgin olive oil with high (EVOO) or low phenolic content (ROO) for 3 months. Wild-type rats (WT) were fed the CO diet. Results: CO-fed HLA-B27 animals developed intestinal inflammation characterized by diarrhea, increased myeloperoxidase activity, and mucosal injury. None of these parameters were influenced by EVOO. Gene expression profiling indicated that proinflammatory pathways were upregulated in the colon mucosa of CO-fed HLA-B27 rats compared to WT, and this was further confirmed by RT-PCR for the iNOS, TNFα, and IL1β genes. EVOO significantly reduced TNFα gene expression in the colon mucosa and decreased total cholesterol blood levels compared to CO HLA-B27 rats (89.43 ± 3.66 vs. 111.5 ± 8.10 mg/dL, p < 0.05). This latter effect with EVOO was associated with reduced HMGCR and increased PPAR-α hepatic gene expression, compared to ROO. Conclusion: These data indicate that olive oil polyphenols do not control colon inflammation in HLA-B27 transgenic rats but exert a positive effect on blood lipids by reducing total cholesterol levels. This preliminary result suggests the need to explore the efficacy of EVOO rich in polyphenols as a complementary strategy for managing hypercholesterolemia and to potentially limit statin-associated myotoxicity.

Anti-inflammatory and antiresorptive effects of Calendula officinalis on inflammatory bone loss in rats.

The aim of this work was to evaluate the anti-inflammatory and antiresorptive effects of Calendula officinalis (CLO) on alveolar bone loss (ABL) in rats. Male Wistar rats were subjected to ABL by ligature with nylon thread around the second upper left molar. The contralateral hemimaxillae were used as control. Rats received saline solution (SAL) or CLO (10, 30, or 90mg/kg) 30min before ligature and daily until the 11th day. The maxillae were removed and prepared for macroscopic, radiographic, micro-tomographic, histopathologic, histometric analysis, and immunohistochemical localization of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG). The gingival tissues were used to quantify the myeloperoxidase (MPO) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) concentrations by ELISA. Blood samples were collected for leukogram and to evaluate the bone-specific alkaline phosphatase (BALP) activity and serum levels of aspartate and alanine transaminases (AST/ALT). The bone loss induced by 11 days of ligature induced bone loss, reduced levels of BALP, leukocyte infiltration, increased MPO activity, gingival concentrations of TNF-α and IL-1β, and RANKL while reduced OPG immunoexpressions in the periodontal tissue and leukocytosis. Of the CLO, 90mg/kg reduced bone loss, neutrophilia, the levels of pro-inflammatory mediators, and RANKL expression, while it increased OPG immunopositive cells and BALP serum levels, when compared to SAL. CLO did not affect either kidney or liver function, indicated by serum AST/ALT levels. The present data suggests that CLO reduced inflammatory bone resorption in experimental periodontitis, which may be mediated by its anti-inflammatory properties and its effects on bone metabolism. CLO can be a potential therapeutical adjuvant in the treatment of periodontitis.

Effects of commercially produced almond by-products on chemotherapy-induced mucositis in rats.

AIMTo determine if almond extracts reduce the severity of chemotherapy-induced mucositis as determined through biochemical, histological and behavioural markers.METHODSIntestinal mucositis is a debilitating condition characterized by inflammation and ulceration of the gastrointestinal mucosa experienced by cancer patients undergoing chemotherapy. Certain bioactive plant products have shown promise in accelerating mucosal repair and alleviating clinical symptoms. This study evaluated almond extracts for their potential to reduce the severity of chemotherapy-induced mucositis in Dark Agouti rats. Female Dark Agouti rats were gavaged (days 3-11) with either PBS, almond hull or almond blanched water extract at two doses, and were injected intraperitoneally with 5-fluorouracil (5-FU-150 mg/kg) or saline on day 9 to induce mucositis. Burrowing behavior, histological parameters and myeloperoxidase activity were assessed.RESULTSBodyweight was significantly reduced in rats that received 5-FU compared to saline-treated controls (P < 0.05). Rats administered 5-FU significantly increased jejunal and ileal MPO levels (1048%; P < 0.001 and 409%; P < 0.001), compared to healthy controls. Almond hull extract caused a pro-inflammatory response in rats with mucositis as evidenced by increased myeloperoxidase activity in the jejunum when compared to 5-FU alone (rise 50%, 1088 ± 96 U/g vs 723 ± 135 U/g, P = 0.02). Other extract-related effects on inflammatory activity were minimal. 5-FU significantly increased histological severity score compared to healthy controls confirming the presence of mucositis (median of 9.75 vs 0; P < 0.001). The extracts had no ameliorating effect on histological severity score in the jejunum or ileum. Burrowing behavior was significantly reduced in all chemotherapy-treated groups (P = 0.001). The extracts failed to normalize burrowing activity to baseline levels.CONCLUSIONAlmond extracts at these dosages offer little beneficial effect on mucositis severity. Burrowing provides a novel measure of affective state in studies of chemotherapy-induced mucositis.

Experimental blunt chest trauma-induced myocardial inflammation and alteration of gap-junction protein connexin 43.

ObjectiveSevere blunt chest trauma in humans is associated with high mortality rates. Whereas lung tissue damage and lung inflammation after blunt chest trauma have extensively been investigated, the traumatic and posttraumatic effects on the heart remain poorly understood. Therefore, the purpose of this study was to define cardiac injury patterns in an experimental blunt chest trauma model in rats.MethodsExperimental blunt chest trauma was induced by a blast wave in rats, with subsequent analysis of its effects on the heart. The animals were subjected either to a sham or trauma procedure. Systemic markers for cardiac injury were determined after 24 h and 5 days. Postmortem analysis of heart tissue addressed structural injury and inflammation 24 h and 5 days after trauma.ResultsPlasma levels of extracellular histones were elevated 24 h and 5 days after blunt chest trauma compared to sham-treated animals. In the heart, up-regulation of interleukin-1β 24 h after trauma and increased myeloperoxidase activity 24 h and 5 days after trauma were accompanied by reduced complement C5a receptor-1 expression 24 h after trauma. Histological analysis revealed extravasation of erythrocytes and immunohistochemical analysis alteration of the pattern of the gap-junction protein connexin 43. Furthermore, a slight reduction of α-actinin and desmin expression in cardiac tissue was found after trauma together with a minor increase in sarcoplasmatic/endoplasmatic reticlulum calcium-ATPase (SERCA) expression.ConclusionsThe clinically highly relevant rat model of blast wave-induced blunt chest trauma is associated with cardiac inflammation and structural alterations in cardiac tissue.

ELR+ chemokine-mediated neutrophil recruitment is involved in 2,4,6-trinitrochlorobenzene-induced contact hypersensitivity.

Contact dermatitis is a form of delayed-type hypersensitivity characterized by localized thickening, papules, redness and vesicles of the skin. A model of contact dermatitis involving repeated challenge of a hapten is adapted to assess dermatitis as characterized by skin thickening. Recently, it was reported that neutrophils have crucial roles in contact hypersensitivity. We thus examined the involvement of CXC chemokines bearing the glutamic acid-leucine-arginine (ELR) motif ("ELR+ chemokines") and neutrophils in the ear swelling induced by 2,4,6-trinitrochlorobenzene (TNCB) challenges in the present study. Mice were sensitized by application of TNCB on their abdominal skin. They were then challenged thrice with TNCB to the ear. The CXCR2 antagonist SB225002 (9mg/kg, i.p.) was administered before each TNCB challenge. Gene expressions and protein levels of the ELR+ chemokines CXCL1, 2 and 5 was increased markedly in mouse ear after the final TNCB challenge. In addition, we indicated that gene expression of CXCL1 was enhanced in the epidermis and dermis upon TNCB challenge. Expression of the CXCL2 gene was enhanced in the epidermis, and that of the CXCL5 gene was enhanced in the dermis. The swelling induced by TNCB challenges was significantly attenuated by SB225002. Furthermore, the increases in myeloperoxidase activity, and expression of myeloperoxidase and neutrophil elastase induced by TNCB challenge in mouse ear were inhibited by SB225002. These data suggest that ear swelling resulting from TNCB challenges might be concerned by upregulated ELR+ chemokine-induced neutrophil recruitment.