Effect of nitro-conjugated linoleic acid on the inflammatory response of murine macrophages activated with lipopolysaccharide derived from Prevotella intermedia.

Nitro-conjugated linoleic acid (NO2-CLA) has been observed to manifest salutary signaling responses, including anti-inflammatory and antioxidant properties. Here, the authors have explored the influence and underlying mechanisms of NO2-CLA on the proinflammatory reaction of murine macrophages that were challenged with lipopolysaccharide (LPS) derived from Prevotella intermedia, a putative periodontopathic bacterium. Treatment of LPS-activated RAW264.7 cells with NO2-CLA notably dampened the secretion of iNOS-derived NO, IL-1ß and IL-6 as well as their gene expressions and significantly enhanced the markers for M2 macrophage polarization. NO2-CLA promoted the HO-1 expression in cells challenged with LPS, and tin protoporphyrin IX, an HO-1 inhibitor, significantly reversed the NO2-CLA-mediated attenuation of NO secretion, but not IL-1ß or IL-6. We found that cells treated with NO2-CLA significantly increased mRNA expression of PPAR-γ compared to control cells, and NO2-CLA significantly reverted the decrease in PPAR-γ mRNA caused by LPS. Nonetheless, antagonists to PPAR-γ were unable to reverse the NO2-CLA-mediated suppression of inflammatory mediators. In addition, NO2-CLA did not alter the p38 and JNK activation elicited by LPS. Both NF-κB reporter activity and IκB-α degradation caused by LPS were notably diminished by NO2-CLA. NO2-CLA was observed to interrupt the nuclear translocation and DNA binding of p50 subunits caused by LPS with no obvious alterations in p65 subunits. Further, NO2-CLA attenuated the phosphorylation of STAT1/3 elicited in response to LPS. We propose that NO2-CLA could be considered as a possible strategy for the therapy of periodontal disease, although additional researches are certainly required to confirm this.

Real-world safety and effectiveness of inhaled nitric oxide therapy for pulmonary hypertension during the perioperative period of cardiac surgery: a post-marketing study of 2817 patients in Japan.

OBJECTIVE: To evaluate the real-world safety and effectiveness of inhaled nitric oxide (INOflo® for Inhalation 800 ppm) for perioperative pulmonary hypertension associated with cardiac surgery in Japan. METHODS: This was a prospective, non-interventional, all-case, post-marketing study of pediatric and adult patients who received perioperative INOflo with cardiac surgery from November 2015-December 2020. Safety and effectiveness were monitored from INOflo initiation to 48 h after treatment completion or withdrawal. Safety outcomes included adverse drug reactions, blood methemoglobin concentrations, and inspired nitrogen dioxide concentrations over time. Effectiveness outcomes included changes in central venous pressure among pediatrics, mean pulmonary arterial pressure among adults, and the partial pressure of arterial oxygen/fraction of inspired oxygen ratio (PaO2/FiO2) in both populations. RESULTS: The safety analysis population included 2,817 Japanese patients registered from 253 clinical sites (pediatrics, n = 1375; adults, n = 1442). INOflo was generally well tolerated; 15 and 20 adverse drug reactions were reported in 14 pediatrics (1.0%) and 18 adults (1.2%), respectively. No clinically significant elevations in blood methemoglobin and inspired nitrogen dioxide concentrations were observed. INOflo treatment was associated with significant reductions in both central venous pressure among pediatrics and mean pulmonary arterial pressure among adults, and significant improvements in PaO2/FiO2 among pediatrics and adults with PaO2/FiO2 ≤ 200 at baseline. CONCLUSIONS: Perioperative INOflo treatment was a safe and effective strategy to improve hemodynamics and oxygenation in patients with pulmonary hypertension during cardiac surgery. These data support the use of INOflo for this indication in Japanese clinical practice.

Effects of Acute Beetroot Juice and Sodium Nitrate on Selected Blood Metabolites and Response to Transient Ischemia: A Crossover Randomized Clinical Trial.

BACKGROUND: Modification of the nitrate (NO3)-nitrite (NO2)-nitric oxide (NO) pathway can be induced by oral intake of inorganic NO3 (NIT) or NO3-rich products, such as beetroot juice (BRJ). OBJECTIVES: The primary aim of this study was to evaluate the plasma changes in betaine, choline, trimethylamine (TMA), trimethylamine N-oxide (TMAO), and NO3/NO2 (NOx) concentrations over 4 h after single oral ingestion of NIT or BRJ. The flow-mediated skin fluorescence (FMSF) method was applied to measure the changes in nicotinamide adenine dinucleotide reduced form (NADH) in response to transient ischemia and reperfusion. We hypothesized that various sources of NO3 may differently affect endothelial and mitochondrial functions in healthy human subjects. METHODS: In a randomized crossover trial, 8 healthy young adults ingested 800 mg NO3 from either NIT or BRJ on 2 separate days with ≥3 d apart. Venous blood samples were collected every hour, and FMSF determination was applied bihourly. RESULTS: Plasma betaine and choline concentrations peaked at 1 h after BRJ ingestion, and remained significantly higher than baseline values at all time points (P < 0.001 and P < 0.001, compared to preingestion values). Over time, BRJ was more effective in increasing NOx compared with NIT (fixed-trial effect P < 0.001). Baseline fluorescence decreased after both NIT and BRJ consumption (fixed-time effect P = 0.005). Transient ischemia and reperfusion response increased because of NO3 consumption (fixed-time effect P = 0.003), with no differences between trials (P = 0.451; P = 0.912; P = 0.819 at 0, 2, and 4 h, respectively). CONCLUSIONS: Acute ingestion of BRJ elevated plasma betaine and choline, but not TMA and TMAO. Moreover, plasma NOx levels were higher in the BRJ trial than in the NIT trial. Various sources of NO3 positively affected endothelial and mitochondrial functions. This trial was registered at clinicaltrials.gov as NCT05004935.

Protective Effect of NO2-OA on Oxidative Stress, Gliosis, and Pro-Angiogenic Response in Müller Glial Cells.

Inflammation and oxidative and nitrosative stress are involved in the pathogenesis of proliferative retinopathies (PR). In PR, a loss of balance between pro-angiogenic and anti-angiogenic factors favors the secretion of vascular endothelial growth factor (VEGF). This vascular change results in alterations in the blood-retinal barrier, with extravasation of plasma proteins such as α2-macroglobulin (α2M) and gliosis in Müller glial cells (MGCs, such as MIO-M1). It is well known that MGCs play important roles in healthy and sick retinas, including in PR. Nitro-fatty acids are electrophilic lipid mediators with anti-inflammatory and cytoprotective properties. Our aim was to investigate whether nitro-oleic acid (NO2-OA) is beneficial against oxidative stress, gliosis, and the pro-angiogenic response in MGCs. Pure synthetic NO2-OA increased HO-1 expression in a time- and concentration-dependent manner, which was abrogated by the Nrf2 inhibitor trigonelline. In response to phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharide (LPS), NO2-OA prevented the ROS increase and reduced the gliosis induced by α2M. Finally, when hypoxic MGCs were incubated with NO2-OA, the increase in VEGF mRNA expression was not affected, but under hypoxia and inflammation (IL-1ß), NO2-OA significantly reduced VEGF mRNA levels. Furthermore, NO2-OA inhibited endothelial cell (BAEC) tubulogenesis. Our results highlight NO2-OA's protective effect on oxidative damage, gliosis; and the exacerbated pro-angiogenic response in MGCs.

Nitrooleic acid inhibits macrophage activation induced by lipopolysaccharide from Prevotella intermedia.

The hypothesis of the present study was that nitro-fatty acids (NO2-FAs) would suppress inflammation associated with periodontal disease. To test this hypothesis, we investigated the influence of nitrooleic acid, a prototypical NO2-FA, on the inflammatory response of murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen associated the etiology of different types of periodontal diseases. LPS was prepared from P. intermedia cells by using phenol-water protocol. Culture supernatants were assayed for nitric oxide (NO), interleukin-1ß (IL-1ß), and IL-6. Real-time polymerase chain reaction and immunoblotting analyses were performed to quantify messenger RNA and protein expression, respectively. The secreted embryonic alkaline phosphatase reporter assay was performed to measure NF-κB activation. The transcription factor assay kit was used to measure DNA-binding of NF-κB subunits. Findings obtained from the present study revealed that nitrooleic acid suppresses the generation and messenger RNA expression of inducible NO synthase-derived NO, IL-1ß, and IL-6 in RAW264.7 cells activated with P. intermedia LPS and promotes macrophage polarization toward anti-inflammatory M2 phenotype. We also found that nitrooleic acid exerts its effect via heme oxygenase-1 induction and suppression of NF-κB signaling. The inhibition of NO and proinflammatory cytokine production by nitrooleic acid was independent from PPAR-γ, JNK, p38, and STAT1/3. Nitrooleic acid may represent a novel class of agent as a host modulator which has therapeutic benefit in periodontal disease, though more work is needed to confirm this.

Effect of methomyl on water quality, growth performance and antioxidant system in liver of GIFT (Oreochromis niloticus) in the presence of peppermint (Mentha haplocalyx Briq.) as a floating bed.

This study was conducted to investigate the effect of methomyl (MET) on water quality, growth and antioxidant system of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) in the presence of peppermint as a floating bed. The concentration of NH3-N, NO2--N, NO3--N and TP in T3 (with 200 g wet peppermint) was significantly lower (P < 0.05) than that in T2 (100 g), T1 (50 g) and control, and the nutrient removal rates were 61.90%, 31.59%, 59.86% and 45.92% in 20 days, respectively. Juveniles GIFT (5.1 ± 0.2 g) were exposed to sub-lethal concentrations of 0.2, 2.0, 20 and 200 µg/L of MET for 45 days. After 6 weeks of a feeding trial, percentage weight gain (PWG), specific growth rate (SGR) and feed conversion ratio (FCR) were significantly decreased in 0.2, 2.0, 20 µg/L MET groups respectively and increased in the 200 µg/L MET group. Compared with the control, no significant changes in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) were detected in the 0.2 µg/L group. The significant increase in activities of SOD, CAT and GPx was accompanied by a diminution in reduced glutathione (GSH) levels resulting with tilapia exposed to 2.0, 20, or 200 µg/L for 45 days. The highest rates observed in SOD, CAT, GPx were 157.63%, 164.05% and 167.46% of the control respectively, and the lowest inhibition rate in GSH was 66.42% of the control. Peppermint as a floating bed can alleviate the adverse effects of MET, such as growth retardation and oxidative stress.

The effect of nitrogen-doped titanium dioxide-modified stainless steel brackets on Streptococcus mutans.

OBJECTIVES: To evaluate the effect of nitrogen (N)-doped titanium dioxide (TiO2) coated stainless steel brackets activated with natural visible light and dental operating lights on Streptococcus mutans concentration in the plaque of orthodontic patients at 30 and 60 days. MATERIALS AND METHODS: A total of 30 patients were recruited for this split-mouth study; 60 upper lateral incisor brackets constituted the study sample. A total of 30 brackets (15 right and 15 left) were coated with N-doped TiO2 using the (radio frequency) magnetron sputtering method. Plaque samples were collected at 30 days and 60 days after appliance placement. S mutans concentration was evaluated using real-time polymerase chain reaction. RESULTS: At both time intervals, the concentration of S mutans in the control group was greater than that in the study group (P = .005). In both the study and the control groups, the S mutans concentrations significantly increased from 30 to 60 days (P = .005). CONCLUSIONS: N-doped TiO2, on exposure to natural visible light and dental operating light, was effective in reducing the plaque concentration of S mutans in orthodontic patients. The efficacy was better at 30 days than at 60 days after placing the orthodontic appliances.

The Dose-Response Association between Nitrogen Dioxide Exposure and Serum Interleukin-6 Concentrations.

Systemic inflammation is an integral part of chronic obstructive pulmonary disease (COPD), and air pollution is associated with cardiorespiratory mortality, yet the interrelationships are not fully defined. We examined associations between nitrogen dioxide (NO2) exposure (as a marker of traffic-related air pollution) and pro-inflammatory cytokines, and investigated effect modification and mediation by post-bronchodilator airflow obstruction (post-BD-AO) and cardiovascular risk. Data from middle-aged participants in the Tasmanian Longitudinal Health Study (TAHS, n = 1389) were analyzed by multivariable logistic regression, using serum interleukin (IL)-6, IL-8 and tumor necrosis factor-α (TNF-α) as the outcome. Mean annual NO2 exposure was estimated at residential addresses using a validated satellite-based land-use regression model. Post-BD-AO was defined by post-BD forced expiratory ratio (FEV1/FVC) < lower limit of normal, and cardiovascular risk by a history of either cerebrovascular or ischaemic heart disease. We found a positive association with increasing serum IL-6 concentration (geometric mean 1.20 (95% CI: 1.1 to 1.3, p = 0.001) per quartile increase in NO2). This was predominantly a direct relationship, with little evidence for either effect modification or mediation via post-BD-AO, or for the small subgroup who reported cardiovascular events. However, there was some evidence consistent with serum IL-6 being on the causal pathway between NO2 and cardiovascular risk. These findings raise the possibility that the interplay between air pollution and systemic inflammation may differ between post-BD airflow obstruction and cardiovascular diseases.

In situ analysis of protein S-glutathionylation in lung tissue using glutaredoxin-1-catalyzed cysteine derivatization.

Protein S-glutathionylation (PSSG) is a posttranslational modification that involves the conjugation of the small antioxidant molecule glutathione to cysteine residues and is emerging as a critical mechanism of redox-based signaling. PSSG levels increase under conditions of oxidative stress and are controlled by glutaredoxins (Grx) that, under physiological conditions, preferentially deglutathionylate cysteines and restore sulfhydryls. Both the occurrence and distribution of PSSG in tissues is unknown because of the labile nature of this oxidative event and the lack of specific reagents. The goal of this study was to establish and validate a protocol that enables detection of PSSG in situ, using the property of Grx to deglutathionylate cysteines. Using Grx1-catalyzed cysteine derivatization, we evaluated PSSG content in mice subjected to various models of lung injury and fibrosis. In control mice, PSSG was detectable primarily in the airway epithelium and alveolar macrophages. Exposure of mice to NO(2) resulted in enhanced PSSG levels in parenchymal regions, while exposure to O(2) resulted in minor detectable changes. Finally, bleomycin exposure resulted in marked increases in PSSG reactivity both in the bronchial epithelium as well as in parenchymal regions. Taken together, these findings demonstrate that Grx1-based cysteine derivatization is a powerful technique to specifically detect patterns of PSSG expression in lungs, and will enable investigations into regional changes in PSSG content in a variety of diseases.

Molecular characterization of atmospheric NO2-responsive germin-like proteins in azalea leaves.

Atmospheric nitrogen dioxide (NO(2)) is an environmental oxidant that is removed through direct uptake by foliage, but plant responses to this highly reactive gas are not well understood at the molecular level. From NO(2)-exposed leaves of a woody azalea (Rhododendron mucronatum), we cloned two cDNAs (RmGLP1 and RmGLP2) for germin-like proteins (GLPs), a group of ubiquitous plant proteins that have been implicated in various plant physiological and developmental processes. Quantitative analysis of mRNA expression, together with immunoblotting data, showed that foliar exposure to NO(2) caused a robust induction of these GLP-encoding genes. When produced in tobacco cell culture, recombinant RmGLP2 was secreted into the apoplast, where it exhibited superoxide dismutase activity. RmGLP1 and RmGLP2 represent the first examples of plant genes that are responsive to airborne NO(2). These enzymes might have a potential role in extracellular defense mechanisms through attenuation of interactions between reactive nitrogen and oxygen species.

Nitrogen dioxide at an ambient level improves the capability of kenaf (Hibiscus cannabinus) to decontaminate cadmium.

As reported previously, atmospheric nitrogen dioxide (NO2) at an ambient level increased plant size and the contents of cell constituents. We investigated this effect of atmospheric NO2 on decontamination of cadmium (Cd) by kenaf (Hibiscus cannabinus). Seventeen-day-old seedlings of kenaf were grown in air either with NO2 or without NO2. (Plants were exposed to 100 +/- 50 ppb NO2 for 10 d under irrigation of 0.1% Hyponex supplemented with 20 microM CdCl2.) Plants were then harvested and the biomass of stems, leaves, and roots, as well as the content of Cd in the organs, was determined. The stem and root biomass per plant were 1.25-1.27-fold greater in +NO2 plants than in -NO2 plants. The Cd content per stem was more than 30% greater in +NO2 plants than in -NO2 plants.

Is general anesthesia a risk for myocardium? Effect of anesthesia on myocardial function as assessed by cardiac troponin-i in two different groups (isofluran+N2O inhalation and propofol+fentanyl iv anesthesia).

BACKGROUND AND OBJECTIVES: Peroperative myocardial infarction (MI) is the most common cause of morbidity and mortality. What is the role of general anesthesia in this process? Is general anesthesia a risk for myocardial infarction? The present study was designed to determine whether the measurement of serum levels of cardiac troponin I (cTnI), a highly sensitive and specific marker for cardiac injury, would help establish the diagnosis of myocardial infarction in two different types of anesthesia. METHOD: Elective abdominal hysterectomy was planned with the permission of the ethic committee in 40 patients who were 20-45 years range, in ASA-I group, and have a Goldman Cardiac Risk Index-0. The patients were divided into two groups. Isoflurane + N2O was administrated to first group, and Propofol + Fentanyl to second group. cTnI levels were determined before anesthesia, after induction before surgery and 9 hours after the second period respectively. RESULTS: There was no significant difference between the groups by the means of demographic properties, hemodynamic parameters and cTnI levels, and the cTnI levels were determined under the basal levels in all samples. CONCLUSION: General anesthesia is not a risk for myocardial infarction to state eliminating risk factors and protection hemodynamia cardiac.

Nitrogen dioxide induces apoptosis and proliferation but not emphysema in rat lungs.

BACKGROUND: Apoptosis of alveolar septal cells has been linked to emphysema formation. Nitrogen dioxide, a component of cigarette smoke, has been shown to induce alveolar epithelial cell apoptosis in vitro. It is hypothesised that exposure of rats to nitrogen dioxide may result in increased alveolar septal cell apoptosis in vivo with ensuing emphysema-that is, airspace enlargement and loss of alveolar walls. METHODS: Fischer 344 rats were exposed to 10 ppm nitrogen dioxide for 3, 7, 21 days or 21 days followed by 28 days at room air. Age-matched control rats were exposed to room air for 3, 21 or 49 days. Lungs fixed at 20 cm fluid column, embedded in paraffin wax, glycol methacrylate and araldite, were analysed by design-based stereology. Alveolar septal cell apoptosis (transferase dUTP nick end labelling assay, active caspase 3) and proliferation (Ki-67), airspace enlargement, total alveolar surface area, and absolute alveolar septal volume as well as the ultrastructural composition of the alveolar wall were quantified. RESULTS: Nitrogen dioxide resulted in an eightfold increase in alveolar septal cell apoptosis at day 3 and a 14-fold increase in proliferation compared with age-matched controls. Airspace enlargement, indicated by a 20% increase in mean airspace chord length, was evident by day 7 but was not associated with loss of alveolar walls. By contrast, nitrogen dioxide resulted in an increase in the total surface area and absolute volume of alveolar walls comprising all compartments. The ratio of collagen to elastin, however, was reduced at day 21. Lungs exposed to nitrogen dioxide for 21 days exhibited quantitative structural characteristics as seen in control lungs on day 49. CONCLUSIONS: Nitrogen dioxide exposure of rats results in increased alveolar septal cell turnover leading to accelerated lung growth, which is associated with an imbalance in the relative composition of the extracellular matrix, but fails to induce emphysema.

S-phase arrest by reactive nitrogen species is bypassed by okadaic acid, an inhibitor of protein phosphatases PP1/PP2A.

In mammalian cells DNA damage activates a checkpoint that halts progression through S phase. To determine the ability of nitrating agents to induce S-phase arrest, mouse C10 cells synchronized in S phase were treated with nitrogen dioxide (NO(2)) or SIN-1, a generator of reactive nitrogen species (RNS). SIN-1 or NO(2) induced S-phase arrest in a dose- and time-dependent manner. As for the positive controls adozelesin and cisplatin, arrest was accompanied by phosphorylation of ATM kinase; dephosphorylation of pRB; decreases in RF-C, cyclin D1, Cdc25A, and Cdc6; and increases in p21. Comet assays indicated that RNS induce minimal DNA damage. Moreover, in a cell-free replication system, nuclei from cells treated with RNS were able to support control levels of DNA synthesis when incubated in cytosolic extracts from untreated cells, whereas nuclei from cells treated with cisplatin were not. Induction of phosphatase activity may represent one mechanism of RNS-induced arrest, for the PP1/PP2A phosphatase inhibitor okadaic acid inhibited dephosphorylation of pRB; prevented decreases in the levels of RF-C, cyclin D1, Cdc6, and Cdc25A; and bypassed arrest by SIN-1 or NO(2), but not cisplatin or adozelesin. Our studies suggest that RNS may induce S-phase arrest through mechanisms that differ from those elicited by classical DNA-damaging agents.

3-nitrotyrosine attenuates respiratory syncytial virus infection in human bronchial epithelial cell line.

3-nitrotyrosine (NO2Tyr), an L-tyrosine derivative during nitrative stress, can substitute the COOH-terminal tyrosine of alpha-tubulin, posttranslationally altering microtubular functions. Because infection of the cells by respiratory syncytial virus (RSV) may require intact microtubules, we tested the hypothesis that NO2Tyr would inhibit RSV infection and intracellular signaling via nitrotyrosination of alpha-tubulin. A human bronchial epithelial cell line (BEAS-2B) was incubated with RSV with or without NO2Tyr. The release of chemokines and viral particles and activation of interferon regulatory factor-3 (IRF-3) were measured. Incubation with NO2Tyr increased nitrotyrosinated alpha-tubulin, and NO2Tyr colocalized with microtubules. RSV-infected cells released viral particles, RANTES, and IL-8 in a time- and dose-dependent manner, and intracellular RSV proteins coprecipitated with alpha-tubulin. NO2Tyr attenuated the RSV-induced release of RANTES, IL-8, and viral particles by 50-90% and decreased alpha-tubulin-associated RSV proteins. 3-chlorotyrosine, another L-tyrosine derivative, had no effects. NO2Tyr also inhibited the RSV-induced shift of the unphosphorylated form I of IRF-3 to the phosphorylated form II. Pre-exposure of the cells to NO(2) (0.15 ppm, 4 h), which produced diffuse protein tyrosine nitration, did not affect RSV-induced release of RANTES, IL-8, or viral particles. NO2Tyr did not affect the potential of viral spreading to the neighboring cells since the RSV titers were not decreased when the uninfected cells were cocultured with the preinfected cells in NO2Tyr-containing medium. These results indicate that NO2Tyr, by replacing the COOH-terminal tyrosine of alpha-tubulin, attenuated RSV infection, and the inhibition appeared to occur at the early stages of RSV infection.

Reactive nitrogen species-induced cell death requires Fas-dependent activation of c-Jun N-terminal kinase.

Nitrogen dioxide is a highly toxic reactive nitrogen species (RNS) recently discovered as an inflammatory oxidant with great potential to damage tissues. We demonstrate here that cell death by RNS was caused by c-Jun N-terminal kinase (JNK). Activation of JNK by RNS was density dependent and caused mitochondrial depolarization and nuclear condensation. JNK activation by RNS was abolished in cells lacking functional Fas or following expression of a truncated version of Fas lacking the intracellular death domain. In contrast, RNS induced JNK potently in cells expressing a truncated version of tumor necrosis factor receptor 1 or cells lacking tumor necrosis factor receptor 1 (TNF-R1), illustrating a dependence of Fas but not TNF-R1 in RNS-induced signaling to JNK. Furthermore, Fas was oxidized, redistributed, and colocalized with Fas-associated death domain (FADD) in RNS-exposed cells, illustrating that RNS directly targeted Fas. JNK activation and cell death by RNS occurred in a Fas ligand- and caspase-independent manner. While the activation of JNK by RNS or FasL required FADD, the cysteine-rich domain 1 containing preligand assembly domain required for FasL signaling was not involved in JNK activation by RNS. These findings illustrate that RNS cause cell death in a Fas- and JNK-dependent manner and that this occurs through a pathway distinct from FasL. Thus, avenues aimed at preventing the interaction of RNS with Fas may attenuate tissue damage characteristic of chronic inflammatory diseases that are accompanied by high levels of RNS.

Effects of a novel gaseous antioxidative system containing a rosemary extract on the oxidation induced by nitrogen dioxide and ultraviolet radiation.

Rosemary is commonly used as a spice and a flavoring agent in food processing. Although the antioxidative properties of its extracts have been investigated, there have been few reports on the volatile components of rosemary. We designed a novel antioxidative system which can generate the volatile constituents in the gaseous phase from a rosemary extract and evaluated the gaseous antioxidative activities against both lipid peroxidation and cell death induced by nitrogen dioxide and ultraviolet radiation. The antioxidative effects of the major volatile components on the oxidation of linoleic acid induced by azo compounds were also investigated in a solution. The volatile components in the novel antioxidative system suppressed the Jurkat cell death induced by nitrogen dioxide and the intracellular formation of reactive oxygen species in fibroblast cells induced by ultraviolet radiation. 1,8-Cineole among the volatile components exerted an antioxidative effect against the oxidation of linoleic acid in a solution induced by azo compounds and ultraviolet radiation. These data suggest that the volatile constituents of a rosemary extract had antioxidative properties and that gaseous exposure antioxidant is a promising method for promoting health.

Repeated daily exposure to 2 ppm nitrogen dioxide upregulates the expression of IL-5, IL-10, IL-13, and ICAM-1 in the bronchial epithelium of healthy human airways.

BACKGROUND: Repeated daily exposure of healthy human subjects to NO2 induces an acute airway inflammatory response characterised by neutrophil influx in the bronchial mucosa AIMS: To assess the expression of NF-kappaB, cytokines, and ICAM-1 in the bronchial epithelium. METHODS: Twelve healthy, young non-smoking volunteers were exposed to 2 ppm of NO2/filtered air (four hours/day) for four successive days on separate occasions. Fibreoptic bronchoscopy was performed one hour after air and final NO2 exposures. Bronchial biopsy specimens were immunostained for NF-kappaB, TNF-alpha, eotaxin, Gro-alpha, GM-CSF, IL-5, -6, -8, -10, -13, and ICAM-1 and their expression was quantified using computerised image analysis. RESULTS: Expression of IL-5, IL-10, IL-13, and ICAM-1 increased following NO2 exposure. CONCLUSION: Upregulation of the Th2 cytokines suggests that repeated exposure to NO2 has the potential to exert a "pro-allergic" effect on the bronchial epithelium. Upregulation of ICAM-1 highlights an underlying mechanism for leucocyte influx, and could also explain the predisposition to respiratory tract viral infections following NO2 exposure since ICAM-1 is a major receptor for rhino and respiratory syncytial viruses.

Dopamine prevents nitration of tyrosine hydroxylase by peroxynitrite and nitrogen dioxide: is nitrotyrosine formation an early step in dopamine neuronal damage?

Peroxynitrite and nitrogen dioxide (NO2) are reactive nitrogen species that have been implicated as causal factors in neurodegenerative conditions. Peroxynitrite-induced nitration of tyrosine residues in tyrosine hydroxylase (TH) may even be one of the earliest biochemical events associated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced damage to dopamine neurons. Exposure of TH to peroxynitrite or NO2 results in nitration of tyrosine residues and modification of cysteines in the enzyme as well as inactivation of catalytic activity. Dopamine (DA), its precursor 3,4-dihydroxyphenylalanine, and metabolite 3,4-dihydroxyphenylacetic acid completely block the nitrating effects of peroxynitrite and NO2 on TH but do not relieve the enzyme from inhibition. o-Quinones formed in the reaction of catechols with either peroxynitrite or NO2 react with cysteine residues in TH and inhibit catalytic function. Using direct, real-time evaluation of tyrosine nitration with a green fluorescent protein-TH fusion protein stably expressed in intact cells (also stably expressing the human DA transporter), DA was also found to prevent NO2-induced nitration while leaving TH activity inhibited. These results show that peroxynitrite and NO2 react with DA to form quinones at the expense of tyrosine nitration. Endogenous DA may therefore play an important role in determining how DA neurons are affected by reactive nitrogen species by shifting the balance of their effects away from tyrosine nitration and toward o-quinone formation.

Influence of epithelial lining fluid lipids on NO(2)-induced membrane oxidation and nitration.

Within the pulmonary epithelial lining layer (ELF), antioxidants such as ascorbic acid (AH(2)) and glutathione (GSH) react with inhaled nitrogen dioxide ((*)NO(2)) to produce reactive oxygen species (ROS) that induce cellular oxidation. Because the ELF contains unsaturated fatty acids (UFA), which potentially react with (*)NO(2) and/or the antioxidant-derived ROS, we studied the influence of aqueous phase model UFA [egg phosphatidylcholine (EggPC) liposomes] on exposure-induced oxidation and nitration of membranes. Our lung surface model used gas phase (*)NO(2) exposures of immobilized red cell membranes (RCM) overlaid with defined aqueous phases. Acetyl cholinesterase (AChE) activity, TBARS, and 3-nitrotyrosine (3-NT) were used to assess protein and lipid oxidation and RCM nitration, respectively. During (*)NO(2) exposure, AH(2) and GSH induced AChE loss and TBARS, which were unchanged with buffer only. Exposures of EggPC generated extensive TBARS but not AChE loss; addition of AH(2)/GSH to EggPC resulted in smaller AChE declines and fewer TBARS. 3-NT formation occurred with or without EggPC, low concentration antioxidants, SOD, catalase, or DTPA, but was inhibitable by desferrioxamine or high antioxidant concentrations. The data suggest that reaction/diffusion limitations govern (*)NO(2) distribution, that (*)NO(2) per se directly nitrates tyrosine residues within hydrophobic regions, and that the induction of secondary oxidative processes is dependent on nonlinear relationships among (*)NO(2) flux rates, antioxidant concentrations, and diffusivity of secondary reactive species.