High Levels Of Nitric Oxide Research Articles

Preventive effect of inulin on (DSS)-induced experimental colitis

Event Abstract Back to Event Preventive effect of inulin on (DSS)-induced experimental colitis Ryma Toumi1, Imene Soufli1, Hayet Rafa1 and Chafia B. Touil-Boukoffa1* 1 University of Sciences and Technology Houari Boumediene, Algeria Introduction: The inflammatory bowel diseases (IBDs), represented mainly by ulcerative colitis and Crohn disease refer to chronic and relapsing disorders that affect the gastrointestinal tract. Studies on animal models of colitis have indicated that these diseases result from a lack of tolerance to resident intestinal bacteria in genetically susceptible hosts (1,2). It seems that in IBD the mucus barrier is broken and penetrated by bacteria and inflammatory cells. The production of high levels of the nitric oxide (NO) by the inflammatory cells plays a part in tissue injury (3,4); In the current study, we investigate the potential preventive effects of inulin on dextran sulphate sodium (DSS)-induced experimental colitis in Swiss albino mice. Methods: The colitis was induced in mice via administration of 2.5% DSS in drinking water for 7 days (5). During this period the Swiss albino mice were given 1% (w/v) inulin in their drinking water ad libitum for 7 days. The production of NO was evaluated in the supernatants of peritoneal macrophages (pMϕ) cultures. The mucus production by the goblet cells in the colon was determined. Crypt damage and inflammation in the distal colon were also evaluated. Results: A significant shortening of colon length was observed and high levels of NO in pMϕ cultures were observed in DSS group compared to control. Oral administration of inulin decreased the severity of DSS-induced colitis. NO production in pMϕ supernatants was lower in inulin group and correlated with a reduction of colonic lesions. Goblet cells with Alcian blue-positive cells were visible reflecting mucus production. Conclusion: The prebiotic inulin improved DSS-induced colitis symptoms by down NO production down regulation and induction of mucus secretion suggesting an anti-inflammatory effects and a beneficial role in preventing colitis. Prebiotics seem to be promising for development of preventive strategies approach for IBD using dietary supplementation.

Measurement of Exhaled Nitric Oxide Using End Tidal Value during Normal Breathing

Increased nitric oxide (NO) production in the expired air has been associated with a number of disease conditions and may reflect the severity of inflammation in the lungs. Measurement of exhaled NO concentration has been proposed as a novel clinical tool for assessing airway inflammation and response to drug therapy. In spite of international guidelines aimed at standardizing the measurement of exhaled NO, clinicians remain skeptical due to the necessity of a significant degree of subject collaboration required by the procedure to obtain meaningful measurements. We hypothesized that exhaled NO concentration may be best measured by using end tidal NO concentration during a breath by breath monitoring. We tested laboratory staff and monitored their NO concentration online using a fast response chemiluminescence NO analyzer during normal breathing at rest for 5 minutes. First we confirmed that the NO analyzer was adequately fast to record fully the swings during normal breathing. We then compared the average end tidal NO value (NOet) from 6 to 10 breaths, to the NO value obtained from the plateau from a single slow vital capacity maneuver as recommended by the ATS guidelines (NOplat). End of exhalation was identified using end tidal carbon dioxide measurement. NOet while breathing room air was 24.3 ± 4.2 (SE) ppb and was not significantly different compared to 22.4 ± 2.8 (SE) ppb using NOplat. Additionally breathing high level of NO of up to 88 ppb did not affect either NOet or NOplat significantly suggesting that both measurements are independent of inhaled NO concentration. NO value at end of exhalation was very reproducible from breath to breath and did not require any special effort on the part of the subject. We recommend using NOet measurement instead of the NOplat value that is highly dependent on the exhalation rate and cooperation of the subject. NOet is much easier to record in children, elderly and patients with respiratory disease. The main requirement for measuring NOet is to have a fast response NO analyzer to record the full swings in NO concentration during normal breathing and to have a way of identifying end exhalation.

Study of the effects of oral zinc supplementation on peroxynitrite levels, arginase activity and NO synthase activity in seminal plasma of Iraqi asthenospermic patients

BackgroundLow concentrations of nitric oxide (NO) are necessary for the biology and physiology of spermatozoa, but high levels of NO are toxic and have negative effects on sperm functions. Although several studies have considered the relationship between infertility and semen NO concentrations, no study on the effects of asthenospermia treatments such as oral zinc supplementation on concentrations of NO, which are important in fertility, has been reported. Studies have shown that oral zinc supplementation develops sperm count, motility and the physical characteristics of sperm in animals and in some groups of infertile men. The present study was conducted to study the effect of zinc supplementation on the quantitative and qualitative characteristics of semen, along with enzymes of the NO pathway in the seminal plasma of asthenospermic patients.MethodsSemen samples were obtained from 60 fertile and 60 asthenozoospermic infertile men of matched age. The subfertile group was treated with zinc sulfate; each participant took two capsules (220 mg per capsule) per day for 3 months. Semen samples were obtained (before and after zinc sulfate supplementation). After liquefaction of the seminal fluid at room temperature, routine semen analyses were performed. The stable metabolites of NO (nitrite) in seminal plasma were measured by nitrophenol assay. Arginase activity and NO synthase activity were measured spectrophotometrically.ResultsPeroxynitrite levels, arginase activity, NO synthase activity and various sperm parameters were compared among fertile controls and infertile patients (before and after treatment with zinc sulfate). Peroxynitrite levels and NO synthase activity were significantly higher in the infertile patients compared to the fertile group. Conversely, arginase activity was significantly higher in the fertile group than the infertile patients. Peroxynitrite levels, arginase activity and NO synthase activity of the infertile patient were restored to normal values after treatment with zinc sulfate. Volume of semen, progressive sperm motility percentage and total normal sperm count were increased after zinc supplementation.ConclusionsTreatment of asthenospermic patients with zinc supplementation leads to restored peroxynitrite levels, arginase activity and NO synthase activity to normal values and gives a statistically significant improvement of semen parameters compared with controls.Trial registrationClinicalTrials.gov identifier: NCT01684059

Effect of Coenzyme Q10 Supplementation on Markers of Oxidative Stress in Streptozotocin Induced Diabetic Rats

Suppressive effect of Ginkgo biloba extract (EGb 761) on topsin induced ovarian toxicity and oxidative stress in albino ratsSaber A. Sakr,Hoda A. Mahran, Asmaa M. Abdel-Maksoud

High altitude adaption: advance in genetics

The indigenous populations of high altitude,physiologically with lower concentration of hemoglobin and higher level of nitric oxide,can be well-adapted to hypoxia and cold environment.Recent studies have revealed that these adaptive highland population possessed genetic bases,which involved a number of genes,such as EPAS1,EGLN1,CBARA1,VAV3,PPARA,and eNOS,associating with hypoxia-inducible pathway,production of red blood cells and vasodilator substances,etc.These findings provided new insights and strategies from genetics to uncover the unique natural environment selection,to understand the mechanisms of plateau diseases,finally to better prevent and treat them.

Gonadal steroids negatively modulate oxidative stress in CBA/Ca female mice infected with P. berghei ANKA.

We decreased the level of gonadal steroids in female and male mice by gonadectomy. We infected these mice with P. berghei ANKA and observed the subsequent impact on the oxidative stress response. Intact females developed lower levels of parasitaemia and lost weight faster than intact males. Gonadectomised female mice displayed increased levels of parasitaemia, increased body mass, and increased anaemia compared with their male counterparts. In addition, gonadectomised females exhibited lower specific catalase, superoxide dismutase, and glutathione peroxidase activities in their blood and spleen tissues compared with gonadectomised males. To further study the oxidative stress response in P. berghei ANKA-infected gonadectomised mice, nitric oxide levels were assessed in the blood and spleen, and MDA levels were assessed in the spleen. Intact, sham-operated, and gonadectomised female mice exhibited higher levels of nitric oxide in the blood and spleen compared with male mice. MDA levels were higher in all of the female groups. Finally, gonadectomy significantly increased the oxidative stress levels in females but not in males. These data suggest that differential oxidative stress is influenced by oestrogens that may contribute to sexual dimorphism in malaria.

Ex vivo immunomodulatory effect of all-trans-retinoic acid during Behçet’s disease: a study in Algerian patients

Uveitis, recurrent oral and genital ulcerations associated with skin lesions are the major symptoms of a chronic multisystemic inflammatory disorder known as Behçet’s disease (BD). High prevalence of this dreaded disease has been observed in the Mediterranean basin, including Algeria and along the Silk Road. Although the etiologic agent of this disease remains uncertain, many hypotheses have been advanced in its pathogenesis. Our team has previously reported high levels of nitric oxide (NO) in sera of BD patients, suggesting its deleterious effect during chronic inflammation. In our current study, the aim is to investigate the ex vivo immunomodulatory effect of all-trans-retinoic acid (ATRA) on NO pathway in Algerian BD patients. First, peripheral blood mononuclear cells isolated from active and inactive BD patients and healthy controls were cultured with different concentrations of ATRA. NO production was estimated with the Griess method. To elucidate the underlying mechanisms of ATRA effect on NO production, we analyze inducible nitric oxide synthase expression and nuclear factor-κB (NF-κB) activity by immunofluorescence test. Our results revealed a higher production of NO in active BD compared with the inactive stage and healthy controls. We observed that ATRA inhibits NO production in BD both in active and inactive stages and inhibits NF-κB translocation. In conclusion, we report a relationship between NO production and the disease activity. ATRA down-regulates NO production in BD patients. This immunomodulatory effect seems to be mediated through NF-κB pathway. All these findings suggest that ATRA could be considered as a promising therapy for BD.

Role of Nitric Oxide in the Onset of Facial Nerve Palsy by HSV-1 Infection

Although herpes simplex virus type 1 (HSV-1) is a causative agent of Bell palsy, the precise mechanism of the paralysis remains unknown. It is necessary to investigate the pathogenesis and treatment of Bell palsy due to HSV-1 infection. This study elucidated the role of nitric oxide (NO) in the incidence of facial nerve paralysis caused by HSV-1 in mice and to evaluate the possible role of edaravone, a free radical scavenger, in preventing the paralysis. Sixty-two mice served as animal models of Bell palsy in this laboratory study conducted at an academic institution. Levels of NO in the facial nerve were measured using high-performance liquid chromatography and absorption photometry. The incidence of facial palsy was assessed following administration of edaravone immediately after HSV-1 inoculation and daily for 11 days thereafter. The ratio of NO (inoculated side to control side) and incidence of facial palsy. RESULTS Before the onset of facial palsy, no substantial difference in the NO level was noted between the HSV-1-inoculated side and the control side. When facial palsy occurred, usually at 7 days after inoculation, the NO level was significantly higher on the inoculated side than on the control side. Following recovery from the palsy, the high NO level of the inoculated side decreased. No increase in the NO level was observed in animals without transient facial palsy. When edaravone was administered, the incidence of facial palsy decreased significantly. These findings suggest that NO produced by inducible NO synthase in the facial nerve plays an important role in the onset of facial palsy caused by HSV-1 infection, which is considered a causative virus of Bell palsy. Hato and colleagues elucidate the role of nitric oxide in HSV-1–related facial nerve paralysis in mice and evaluate the role of edaravone, a free radical scavenger, in preventing the paralysis.

Nitric oxide production by endotoxin preparations in TLR4-deficient mice

Sepsis and septic shock result from an exacerbated systemic inflammatory reaction to infection. Their incidence is rising, and they have recently become the main cause of death in intensive care units. Septic shock is defined as sepsis accompanied by life-threatening refractory hypotension, for which excessive nitric oxide (NO), produced by inducible NO synthase iNOS, is thought responsible. LPS, a vital outer membrane component of Gram-negative bacteria, mimics most of the septic effects and is widely used as a model for septic shock. TLR4 is the signal-transducing receptor for LPS, evidenced by the resistance of TLR4-deficient C3H/HeJ and C57BL/10ScNJ mice. As expected, we found that TLR4 deficiency precludes LPS-induced cytokine production, independent of the purity of the LPS preparation. However, various conventional LPS preparations induced NO in TLR4-deficient mice to the same level as in control animals, while ultrapure LPS did not, indicating the presence of NO-producing contaminant(s). Nevertheless, despite identical iNOS induction pattern and systemic NO levels, the contaminant does not cause hypotension, hypothermia, or any other sign of morbidity. Using mice deficient for TLR2, TRL3, TLR4, TRL2x4, TLR9, MyD88 or TRIF, we found that the contaminant signals via TLR2 and MyD88. In conclusion, conventional LPS preparations generally used in endotoxic shock research contain TLR2 agonists that induce iNOS and high levels of systemic NO as such, and synergize with LPS towards the production of pro-inflammatory cytokines, morbidity and mortality. Surprisingly, the excessive iNOS-derived systemic NO production induced by impure LPS in TLR4−/− is not accompanied by hypotension or morbidity.

SR-A Regulates the Inflammatory Activation of Astrocytes

Scavenger receptor Class A (SR-A) participates in the regulation of inflammatory processes against pathogens and in inflammatory stimulation. We have recently demonstrated the presence of SR-A in astrocytes, but its participation in their inflammatory response is unknown. Astrocytes regulate neuroinflammation through the regulation of microglial cell activation and the production of cytokines, neurotrophic factors, and reactive species. Using astrocytes from SR-A(-/-) mice in culture, we assessed the participation of SR-A in their inflammatory activation, evaluating the activation of IκB/NF-κB and MAPK signaling pathways and the production of nitric oxide (NO) and IL-1β in response to SR-A ligands. In SR-A(-/-) astrocytes, lipopolysaccharide (LPS) induced higher levels of NO and reduced levels of IL-1β compared to SR-A(+/+) cells. In addition, SR-A(-/-) astrocytes had a reduced basal and LPS-stimulated JNK phosphorylation, and a delayed activation on IκB/NF-κB signaling pathway in response to LPS. Moreover, inhibition of the ERK pathway reduced NO production by SR-A(-/-) cells, suggesting that this signaling pathway modulated LPS-induced NO production, an effect that depended on the presence of SR-A. Our results suggest that SR-A participates in the modulation of signaling pathways involved in the production of soluble molecules implicated in the neuroinflammatory response.

TXNIP Deficiency Exacerbates Endotoxic Shock via the Induction of Excessive Nitric Oxide Synthesis

Thioredoxin-interacting protein (TXNIP) has multiple functions, including tumor suppression and involvement in cell proliferation and apoptosis. However, its role in the inflammatory process remains unclear. In this report, we demonstrate that Txnip−/− mice are significantly more susceptible to lipopolysaccharide (LPS)-induced endotoxic shock. In response to LPS, Txnip−/− macrophages produced significantly higher levels of nitric oxide (NO) and inducible nitric oxide synthase (iNOS), and an iNOS inhibitor rescued Txnip−/− mice from endotoxic shock-induced death, demonstrating that NO is a major factor in TXNIP-mediated endotoxic shock. This susceptibility phenotype of Txnip−/− mice occurred despite reduced IL-1β secretion due to increased S-nitrosylation of NLRP3 compared to wild-type controls. Taken together, these data demonstrate that TXNIP is a novel molecule that links NO synthesis and NLRP3 inflammasome activation during endotoxic shock.

Co-administration of iron sulphate and nitroglycerin promoted oxidative stress and mild tissue damage in Wistar rats

There is no clear-cut understanding yet of the effect of a sustained production of nitric oxide (NO) either through endogenous or exogenous source on the iron (Fe) metabolism in living cells. Albeit, there are evidences linking decreased NO production to increased iron levels. A high level of free iron in living cells, predispose such systems to oxidative damage through the promotion of free hydroxyl radical generation. On the other hand, a continuous and sustained high level of NO could contribute to cellular damage arising from the debilitating effect of peroxynitrite, a very reactive free radical formed between free NO and superoxide anion. This study investigated the biochemical influence of individual or co-administration of two drugs; nitroglycerin (NGC) and ferrous sulphate (FeSO4) in rats. Data revealed elevated levels of alanine transaminase, aspartate transaminase, and alkaline phosphatase as well as high malondialdehyde concentrations. Consequently, the levels of superoxide dismutase and catalase were raised. The histopathological presentations show the presence of gradual and subtle cellular damage. We present evidence that individual or co-administration of FeSO4 or NGC promoted the generation of free radical species which might have caused the tissue damage observed.

Methylprednisolone Stiffens Aortas in Lipopolysaccharide-Induced Chronic Inflammation in Rats

IntroductionGlucocorticoids are commonly used as therapeutic agents in many acute and chronic inflammatory and auto-immune diseases. The current study investigated the effects of methylprednisolone (a synthetic glucocorticoid) on aortic distensibility and vascular resistance in lipopolysaccharide-induced chronic inflammation in male Wistar rats.MethodsChronic inflammation was induced by implanting a subcutaneous slow-release ALZET osmotic pump (1 mg kg−1 day−1 lipopolysaccharide) for either 2 or 4 weeks. Arterial wave transit time (τ) was derived to describe the elastic properties of aortas using the impulse response function of the filtered aortic input impedance spectra.ResultsLong-term lipopolysaccharide challenge enhanced the expression of advanced glycation end products (AGEs) in the aortas. Lipopolysaccharide also upregulated the inducible form of nitric oxide synthase to produce high levels of nitric oxide (NO), which resulted in vasodilation, as evidenced by the fall in total peripheral resistance (Rp). However, lipopolysaccharide challenge did not influence the elastic properties of aortas, as shown by the unaltered τ. The NO-mediated vascular relaxation may counterbalance the AGEs-induced arterial stiffening so that the aortic distensibility remained unaltered. Treating lipopolysaccharide-challenged rats with methylprednisolone prevented peripheral vasodilation because of its ability to increase Rp. However, methylprednisolone produced an increase in aorta stiffness, as manifested by the significant decline in τ. The diminished aortic distensibility by methylprednisolone paralleled a significant reduction in NO plasma levels, in the absence of any significant changes in AGEs content.ConclusionMethylprednisolone stiffens aortas and elastic arteries in lipopolysaccharide-induced chronic inflammation in rats, for NO activity may be dominant as a counteraction of AGEs.

In vivo, in vitro, and in silico studies suggest a conserved immune module that regulates malaria parasite transmission from mammals to mosquitoes

Human malaria can be caused by the parasite Plasmodium falciparum that is transmitted by female Anopheles mosquitoes. “Immunological crosstalk” between the mammalian and anopheline hosts for Plasmodium functions to control parasite numbers. Key to this process is the mammalian cytokine transforming growth factor-β1 (TGF-β1). In mammals, TGF-β1 regulates inducible nitric oxide (NO) synthase (iNOS) both positively and negatively. In some settings, high levels of NO activate latent TGF-β1, which in turn suppresses iNOS expression. In the mosquito, ingested TGF-β1 induces A. stephensi NOS (AsNOS), which limits parasite development and which in turn is suppressed by activation of the mosquito homolog of the mitogen-activated protein kinases MEK and ERK. Computational models linking TGF-β1, AsNOS, and MEK/ERK were developed to provide insights into this complex biology. An initial Boolean model suggested that, as occurs in mammalian cells, MEK/ERK and AsNOS would oscillate upon ingestion of TGF-β1. An ordinary differential equation (ODE) model further supported the hypothesis of TGF-β1-induced multiphasic behavior of MEK/ERK and AsNOS. To achieve this multiphasic behavior, the ODE model was predicated on the presence of constant levels of TGF-β1 in the mosquito midgut. Ingested TGF-β1, however, did not exhibit this behavior. Accordingly, we hypothesized and experimentally verified that ingested TGF-β1 induces the expression of the endogenous mosquito TGF-β superfamily ligand As60A. Computational simulation of these complex, cross-species interactions suggested that TGF-β1 and NO-mediated induction of As60A expression together may act to maintain multiphasic AsNOS expression via MEK/ERK-dependent signaling.We hypothesize that multiphasic behavior as represented in this model allows the mosquito to balance the conflicting demands of parasite killing and metabolic homeostasis in the face of damaging inflammation.

Protective and curative effect of silymarin against chlorpyrifos-induced immunotoxicity in rats

Chlorpyrifos (CPF) is a widely used organophosphorus insecticide throughout the world inagriculture and anti-termites around homes. Silymarin is a naturally occurring substance and hasantioxidant effects. For decades, it has been used clinically in Europe for the treatment ofalcoholic liver disease and as anti-hepatotoxic agent. Therefore, the present study aimed toassess the protective and curative effect of silymarin in attenuating the CPF-inducedimmunotoxicity in rats, by measuring the level of immunoglobulin G (IgG), lymphocyteviability, neutrophil phagocytic function assay, total white blood cells count (WBC) and relativedifferential white blood cells count, as well as nitric oxide (NO) level and catalase activity. Thetreatment with CPF decreased lymphocyte viability, neutrophil phagocytic index, total whiteblood cells count, relative lymphocyte count, IgG concentration and catalase activity. On theother hand, a high level of NO was detected upon animal treatment with CPF. Interestingly,pre- and post-treatment with silymarin to CPF-treated group improved the lymphocyte viability,total white blood cells count, relative lymphocyte count, catalase activity and the NO level. Preandpost-treatment with silymarin recovered phagocytic activity of neutrophils and restored IgGlevel. In conclusion, silymarin has both protective and curative effects against CPF-inducedimmunotoxicity may be through its anti-oxidant effects.

Nitric oxide donating anilinopyrimidines: Synthesis and biological evaluation as EGFR inhibitors

To search for potent nitric oxide (NO) donating epidermal growth factor receptor (EGFR) inhibitors, a series of phenylsulfonylfuroxan-based anilinopyrimidines 10a–h were synthesized and biologically evaluated. Compounds 10f–h exhibited potent inhibitory activity against EGFR L858R/T790M and were as potent as WZ4002 in inhibition of H1975 cells harboring EGFR L858R/T790M. Additionally, 10h produced high levels of NO in H1975 cells but not in normal human cells, and its antiproliferative activity was diminished by hemoglobin, an NO scavenger. Furthermore, 10h inhibited EGFR activation and downstream signaling in H1975 cells. These results suggest that the strong antiproliferative activity of 10h could be attributed to the synergic effects of high levels of NO production and inhibition of EGFR and downstream signaling in the cancer cells.

Characteristics of ozone and its precursors in Northern China: A comparative study of three sites

Regional composite pollution and variation of atmospheric oxidizing ability are significant problems in Beijing and its surrounding areas. In particular, a southwest–northeast prevailing wind makes nonlinear variation of ozone and its precursors complex. In this study, simultaneous measurements of surface ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen oxide (NOx) and carbon monoxide (CO) were carried out from August 2009 to June 2010 to investigate ozone level and precursor concentrations in Northern China. Gucheng (GC), Longtanhu (LTH) and Xinglong (XL) were selected to represent rural area, urban area and background area in North China Plain, respectively. The results showed that there were two peaks for primary pollutants (NOx and CO) at urban and rural areas, and the highest values appeared nearly on rush hours. There was a single peak for O3 and Ox with peak values appearing at afternoon. The primary pollutants at urban and rural areas were higher than those in background region. However, the concentration of secondary pollutant O3 at downwind background areas was much higher than other sites due to transportation. Diurnal variations of pollutants indicated that O3 and Ox had peak values at afternoon, while other primary pollutants showed two peak values nearly on rush hours. Furthermore, high concentrations of O3 and Ox at background site XL also implied a robust atmospheric oxidizing ability. A positive correlation was observed between CO and O3 at XL site, which implied that air masses to the site had a large loading of anthropogenic emission experiencing strong photochemical processing. The correlation between CO and O3 was negative at GC and LTH, which indicated that local emission of precursors had significant influence on the formation of ozone. There was a positive correlation between NOx and Ox at GC and XL, which implied that NOx contributed to the formation of ozone, while a negative correlation meant titration in urban site LTH neutralized the formation of ozone due to high level of NO.

Myeloid-derived suppressor cells ameliorate the pathogenesis of autoimmune arthritis (P1058)

Abstract Myeloid-derived suppressor cells (MDSCs) are subtypes of monocytes and granulocytes that suppress T cell activity in diseases like cancer and multiple sclerosis. Our previous studies suggested a subset of monocytes may act as MDSCs in autoimmune arthritis. Using the collagen-induced arthritis (CIA) model we identified an increase in the Ly6Chigh subset of monocytes in the periphery of WT mice with CIA compared to naïve mice. This subset was absent from the periphery of CCR2-deficient mice and these mice developed more severe CIA disease. Ly6Chigh monocytes isolated from immunized mice inhibited collagen-activated CD4+T cell proliferation as well as reduced the overall T cell numbers. In the presence of Ly6Chigh monocytes we observed high levels of nitric oxide in the supernatants and an increase in Annexin V positive CD4+T cells. To examine the biological role of these monocytes, we performed a cell-based treatment assay. Compared to control mice, in vivo transfer of Ly6Chigh monocytes to collagen-immunized mice resulted in delayed onset of disease, reduced joint swelling, decreased IL-6, IL-1β, and IFNγ expression in the joints and decreased IL-6 and IL-17 levels in the serum. In summary, Ly6Chigh monocytes function as MDSCs to inhibit CD4+T cell proliferation and survival. In vivo transfer of Ly6Chigh monocytes ameliorated autoimmune arthritis in the CIA model suggesting these cells could potentially be used in cell-based therapies for treatment of rheumatoid arthritis.

P20: Evaluation of generation of nitric oxide by reducing nitrite with antioxidants in drinks

Background Nitrate, contained in vegetables and also secreted as saliva, is known to be reduced to nitrite in the oral cavity. When nitrite is swallowed with antioxidants, nitrite is reduced to nitric oxide (NO) in gastric acidic conditions. In this study, NO generation in acidic conditions by reducing nitrite with antioxidants contained in drinks were evaluated. Methods Sample drinks were added to 50 mL of a citrate buffer solution (pH 2) containing sodium nitrite. Vegetable juice, tomato juice, green tea, coffee and red wine were used due to its healthy and antioxidative effects. Generated NO concentration was measured using an NO sensor (amiNO-700; Innovative Instruments). Nitrate and nitrite concentrations in various drinks were measured by a NOx analyzer (ENO-20; EICOM). Results Addition of each of the drinks to a nitrite-containing buffer solution induced generation of NO. Generated NO concentration varied depending on the kind and volume of drink added and concentration of nitrite added. Generated NO concentration was higher with green tea, coffee and red wine than vegetable juice and tomato juice. Green tea, coffee and red wine are rich in polyphenols of catechin, chlorogenic acid and tannin, respectively. These polyphenols are known for their strong reductive effects and thus may be also effective reducing substances for NO generation. Vegetable juice and tomato juice contains various vitamins, and tomato juice contains much lycopene as antioxidants; however, the reducing effect of these drinks is known to be smaller than that of drinks containing much polyphenols. It should be noted that green tea and red wine contain vitamin C and sulfite, respectively, as additional antioxidants. An additional experiment using vitamin C and sulfite as reducing substances instead of drinks shows that NO generated with green tea and red wine was mostly derived from the natural compounds in drinks. Conclusion Generation of NO by reducing nitrite with drinks containing antioxidants was evaluated in acidic conditions. Green tea, coffee and red wine generate higher levels of NO than vegetable juice and tomato juice. Polyphenols are thus demonstrated to be highly potential reducing substances for generating NO from nitrite in acidic conditions. Disclosure Nothing to disclose.

Simvastatin reduces VEGF and NO levels in acute stages of experimental traumatic brain injury

This study was undertaken to evaluate the effect of simvastatin, a cholesterol-lowering agent, on vascular endothelial growth factors (VEGFs), nitric oxide (NO) levels and neuroprotection, in rats with experimentally induced traumatic brain injury (TBI). Forty Wistar albino rats were categorized into four groups: sham operated (S), trauma (T), trauma + vehicle (T + V) and trauma + simvastatin (T + S). The T, T + V and T + S groups were subjected to TBI. The T + V group was administered vehicle [ethanol:saline (1/2)] and the T + S group was administered 1 mg/kg of simvastatin 3 h after the injury insult. Blood and brain tissue specimens were obtained 24 h after the trauma to measure VEGFs and NO levels and perform histopathological examinations. The histopathological injury scores of brain tissues were significantly higher in the T group, and simvastatin significantly prevented brain injury in the T + S group. In the T group, significant increases of VEGF levels in serum and brain tissues were noted, which were prevented with simvastatin treatment in the T + S group. The markedly high levels of NO in brain tissues of the T group were decreased by simvastatin treatment in the T + S group. It can be concluded that, as evidenced by histopathological findings, simvastatin treatment improves neuropathology in acute stages of TBI.