Nitrite Release Research Articles

Sequestration and release of nitrite and nitrate in alkali-activated slag: A route toward smart corrosion control

Intercalating the corrosion inhibitive ions in hydrotalcite is a promising approach to improve the long-term efficiency of inhibitors in corrosion protection of steel in reinforced concrete. In this work, the potential of autogenously generating nitrite- and nitrate-intercalated hydrotalcite in alkali-activated slag (AAS) is investigated. The results show that the added nitrite and nitrate ions are preferably uptaken in the interlayer structure of hydrotalcite in AAS, and the sequestered nitrite and nitrate are released upon chloride exposure in seawater and NaCl solution. The incorporation of nitrite and nitrate has little detrimental effects on the chloride binding capacity of AAS but slightly enhances the chloride ingress due to the pore coarsening effect. Similar to ordinary Portland cement (OPC), AAS is more permeable to the chloride in seawater than NaCl solution. However, unlike the release of bound chloride contributed by ettringite formation in seawater-exposed OPC, the enhanced chloride ingress in seawater-exposed AAS is primarily attributed to the aggravated pH reduction at the exposure front due to brucite formation. This study contributes to the design of alkali-activated binders with a smart inhibitor releasing ability for mitigating corrosion of steel in concrete.

Resveratrol and Curcumin Attenuate Ex Vivo Sugar-Induced Cartilage Glycation, Stiffening, Senescence, and Degeneration.

Advanced glycation end-product (AGE) accumulation is implicated in osteoarthritis (OA) pathogenesis in aging and diabetic populations. Here, we develop a representative nonenzymatic glycation-induced OA cartilage explant culture model and investigate the effectiveness of resveratrol, curcumin, and eugenol in inhibiting AGEs and the structural and biological hallmarks of cartilage degeneration. Bovine cartilage explants were treated with AGE-bovine serum albumin, threose, and ribose to determine the optimal conditions that induce physiological levels of AGEs while maintaining chondrocyte viability. AGE crosslinks, tissue stiffness, cell viability, metabolism and senescence, nitrite release and loss of glycosaminoglycans were assessed. Explants were cotreated with resveratrol, curcumin, or eugenol to evaluate their anti-AGE properties. Blind docking analysis was conducted to estimate binding energies of drugs with collagen II. Treatment with 100 mM ribose significantly increased AGE crosslink formation and tissue stiffness, resulting in reduced chondrocyte metabolism and enhanced senescence. Blind docking analysis revealed stronger binding energies of both resveratrol and curcumin than ribose, with glycation sites along a human collagen II fragment, indicating their increased likelihood of competitively inhibiting ribose activity. Resveratrol and curcumin, but not eugenol, successfully inhibited AGE crosslink formation and its associated downstream biological response. We establish a cartilage explant model of OA that recapitulates several aspects of aged human cartilage. We find that resveratrol and curcumin are effective anti-AGE therapeutics with the potential to decelerate age-related and diabetes-induced OA. This in vitro nonenzymatic glycation-induced model provides a tool for screening OA drugs, to simultaneously evaluate AGE-induced biological and mechanical changes.

Degradation of high energetic material hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by a microbial consortium using response surface methodological approach

Soil and water get polluted with hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) during its manufacturing, storage and use for civil and military purposes. RDX has toxic effects on living and non-living environment and is a recalcitrant compound. Therefore, the remediation of this compound is necessary. Microbial degradation of RDX can be a suitable and sustainable option to reduce its deleterious impact on the environment. Therefore, the optimization for degradation of energetic munition compound RDX employing the consortium of native bacterial species, isolated from an actual contaminated site, was performed. The experiment was planned with three independent variables (initial RDX concentration, inoculum size of microbes, and duration of the experiment) and three dependent variables (percentage removal of RDX, optical density, and nitrite release). Both independent and dependent variables were analyzed by the response surface methodology (RSM) using the Box–Behnken design. The statistical analysis using analysis of variance (ANOVA) depicted a high regression coefficient, R2 = 0.9881 with the statistically significant p-value fitted into a quadratic regression model for percentage removal of RDX. Results showed an initial RDX concentration of 40 mg/L, inoculation size 6 mL and a time duration of 12 days was optimal for the reduction of RDX up to 80.4%.

Nanoparticle-Mediated Radiation-Triggered Release Of Nitrate, Precursor Of Reactive Nitrogen Species, Improves Local Tumor Control

The efficacy of gold nanoparticles (AuNP) as dose-enhancing agents are adversely affected by low tumor uptake, low membrane penetration, and the locality of the AuNP dose enhancement away from relevant targets. To address these limitations, we propose a novel AuNP system for radiation-triggered release of nitrate, a precursor of reactive nitrogen species, and investigate the AuNP efficacy in-vivo. AuNPs were functionalized through PEGylation for increased in vivo circulation time, addition of cell-penetrating peptides (CPP) ([email protected]) for increased membrane penetration, and addition of nitroimidazole (nIm) ([email protected]) to transform local dose enhancement in nitrite release and subsequent generation of reactive nitrogen species that contribute to cell death. NU/NU mice with subcutaneous tumors of the radioresistant breast tumor model 4T1 were injected with either [email protected] or [email protected] via intra-peritoneal injection. Uptake in tumor and normal tissue uptake was assessed at 6 and 24 h after injection. Another cohort of mice was injected and irradiated to a dose of 18 Gy 24h after injection and followed for 2 weeks post irradiation to evaluate tumor response. The mean physical and hydrodynamic size of the nanoparticle systems was 5 and 15 nm, respectively. The addition of nIm on the surface of the nanoparticles did not significantly affect size distribution. A nIm loading of 1 wt% was determined. The tumor accumulation (percent of injected dose per gram (%ID/g)) of [email protected] was significantly lower than the [email protected] accumulation (0.2%ID/g vs 1.2%ID/g). The reverse was seen for normal tissue where [email protected] showed higher accumulation in liver and spleen compared to [email protected] Concerning tumor response, no differential effect was found in un-irradiated mice injected with either saline or [email protected] alone. Furthermore, the combination of [email protected] and radiation had no differential effect from radiation alone. A significant delay in tumor regrowth was observed in the irradiated [email protected] group compared to irradiated controls. The successful synthesis of AuNP functionalized with CPP and nIm showed a significantly increased therapeutic response compared to the same nanoparticle system without nIm. This was observed despite an order of magnitude lower accumulation in tumor tissue. With improved biokinetics, this nanoparticle system would be a promising novel sensitizer of radioresistant and hypoxic tumors.

The abnormal expression of kisspeptin regulates pro-inflammatory cytokines, cell viability and apoptosis of macrophages in hyperandrogenism induced by testosterone

Background Increasing evidences have proposed that kisspeptins may be involved in polycystic ovary syndrome (PCOS) including hyperandrogenism. This work aimed to investigate the effect of kisspeptin in hyperandrogenism induced by testosterone. Methods The most suitable concentration of testosterone to induce hyperandrogenism was determined by detecting the mRNA changes of kisspeptin and macrophages pro-inflammatory cytokines. The role of kisspeptin in hyperandrogenism was investigated by RT-PCR of kisspeptin and pro-inflammatory cytokines, by CCK-8 of cell viability, by Annexin V-FITC/PI staining followed by flow cytometry of apoptosis, by ELISA of pro-inflammatory cytokines and by Western blot of kisspeptin and antiapoptotic Bcl-2 and proapoptotic Bax. Results We found that testosterone elevated kisspeptin, pro-inflammatory cytokines expressions and nitrite release in excessive androgen stimulated macrophages and further inhibited the macrophages cell viability and increased apoptosis. Kisspeptin knockdown reversed the tendency caused by testosterone and decreased apoptosis in macrophages treated with testosterone. Moreover, mRNA and protein expression levels of Bcl-2 and Bax were assessed. We showed a reduction in Bcl-2 mRNA and protein expression levels and an overexpression of Bax mRNA and protein expression levels. Kiss1 silencing reversed Bcl-2 and Bax expressions. Conclusion Kisspeptin inactivation confers resistance in hyperandrogenism by inhibiting pro-inflammatory cytokines expressions and apoptosis. Our results may help to comprehend the role of kisspeptin in the mechanisms of hyperandrogenism.

Increased local tumor control through nanoparticle-mediated, radiation-triggered release of nitrite, an important precursor for reactive nitrogen species

The efficacy of dose-enhancing gold nanoparticles (AuNPs) is negatively impacted by low tumor uptake, low cell membrane penetration, limited diffusion distance, and short lifetime of radiation-induced secondary particles. To overcome these limitations, we have developed a novel AuNP system capable of radiation-triggered release of nitrite, a precursor of reactive nitrogen species, and report here on the in vivo characterization of this system.AuNPs were functionalized through PEGylation, cell-penetrating peptides (CPP; AuNP@CPP), and nitroimidazole (nIm; AuNP@nIm-CPP). Mice with subcutaneous 4T1 tumors received either AuNP@nIm-CPP or AuNP@CPP intraperitoneally. Tumor and normal tissue uptake were evaluated 24 h post AuNP administration. A separate cohort of mice was injected and irradiated to a single-fraction dose of 18 Gy in a 225 kVp small animal irradiator 24 h post NP administration. The mice were followed for two weeks to evaluate tumor response.The mean physical and hydrodynamic size of both NP systems were 5 and 13 nm, respectively. NP nIm-loading of 1 wt% was determined. Tumor accumulation of AuNP@nIm-CPP was significantly lower than that of AuNP@CPP (0.2% vs 1.2%, respectively). In contrast, AuNP@nIm-CPP showed higher accumulation compared to AuNP@CPP in liver (16.5% vs 6.6%, respectively) and spleen (10.8% vs 3.1%, respectively). With respect to tumor response, no differential response was found between non-irradiated mice receiving either saline or AuNP@nIm-CPP alone. The combination of AuNP@CPP+ radiation showed no differential response from radiation alone. In contrast, a significant delay in tumor regrowth was observed in mice receiving AuNP@nIm-CPP+ radiation compared to radiation alone.AuNP functionalized with both CPP and nIm exhibited an order of magnitude less tumor accumulation compared to the NP system without nIm yet resulted in a significantly higher therapeutic response. Our data suggest that by improving the biokinetics of AuNP@nIm-CPP, this novel NP system could be a promising radiosensitizer for enhanced therapeutic response following radiation therapy.

Photoperiodic manipulation modulates the innate and cell mediated immune functions in the fresh water snake, Natrix piscator

Objectives of the current work were to investigate the role of photoperiod and melatonin in the alteration of immune responses in a reptilian species. Animals were kept on a regimen of short or long days. Blood was obtained and leucocytes were isolated to study various innate immune responses. Lymphocytes were separated from blood by density gradient centrifugation and were used to study proliferation. Respiratory burst activity was measured through nitrobluetetrazolium reduction assay while nitric oxide production by leucocytes was assayed by nitrite assay. Lymphocytes were isolated and used to study proliferation with and without B and T cell mitogens. Photoperiodic manipulation acted differentially on leucocyte counts. Nitrite release was increased while superoxide production was decreased in cultures obtained from the snakes kept on the short day regimen. Significant enhancement of mitogen induced lymphocyte proliferation was observed in cultures from the animals kept in either long or short days compared to cultures from the animals kept in natural ambient day length. Use of in vitro melatonin showed that lymphocytes from the animals, kept in long days, were more reactive. Photoperiod induces changes in immune status which may permit adaptive functional responses in order to maintain seasonal energetic budgets of the animals. Physiological responses (like elevated immune status) are energetically expensive, therefore, animals have evolved a strategy to reduce immune functions at times when energy is invested in reproductive activities. Natrix piscator breeds from September to December and elevated pineal hormone in winter suppresses reproduction while immunity is stimulated.

Acetylcholinesterase inhibitory activity, anti-inflammatory, and neuroprotective potential of Hippeastrum psittacinum (Ker Gawl.) herb (Amaryllidaceae)

Hippeastrum psittacinum, Amaryllidaceae, is used in traditional medicine as a purgative, aphrodisiac, and anticough remedy. The ethanol extract (EE) and alkaloid-rich fractions (ARF) from H. psittacinum bulbs were evaluated for their acetylcholinesterase (AChE) inhibition. The EE cytotoxic and anti-inflammatory effects in RAW 264.7 cells, and the neuroprotective and genotoxic activities in SH-SY5Y cells, were also estimated. Fifteen alkaloids were identified in the EE by gas chromatography–mass spectrometry. ARFs were less active for AChE inhibition than EE. The viability of both cell lines was higher than 70% with EE concentrations below 25 μg/mL. The EE decreased nitrite release in RAW cells stimulated with lipopolysaccharide, showing values of 83, 67, and 53% at 6.25, 12.5, and 25 μg/mL, respectively. Furthermore, the EE partially protected SH-SY5Y cells from hydrogen peroxide-mediated deleterious effects by approximately 50% at the same concentrations. The micronucleus assays showed that the extract caused chromosomal missegregation at concentrations above 12.5 μg/mL. The in silico analyses showed that some alkaloids presented properties of permeation of the blood-brain barrier and the intestine. Our findings present new evidence of the potential of H. psittacinum potential as an AChE inhibitor, as well as an anti-inflammatory and neuroprotective agent.

Cardioprotective effects of resveratrol following myocardial ischemia and reperfusion.

Resveratrol (RSV), a plant origin polyphenol, has shown beneficial cardiovascular effects. In this study, isolated hearts from male Wistar rats were studied using the Langendorff technique. Following 30min stabilization, the hearts underwent 30min global ischemia and 120min reperfusion. The perfusion solution in the test group contained RSV (10μM). Hemodynamics of the hearts, the markers of myocardial damage including creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and troponin I were studied during the study. Furthermore, the infarct size and the markers of oxidative stress including catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPX) were assayed in the homogenates of the hearts. The release of nitrite from the hearts and the occurrence of ventricular arrhythmias were also monitored throughout the experiment. Resveratrol caused a significant improvement in the restoration of the mechanical performance of the hearts following myocardial ischemia and reperfusion (MIR). Besides, the infarct size, CK-MB, LDH, and troponin I declined in the test group. Besides, the cardiac release of nitrite increased, and the redox status of the heart was improved as indicated by the levels of CAT, SOD, GPX, and MDA. Finally, the treatment caused significant decreases in the occurrences of single and salvo arrhythmias, ventricular tachycardia, and ventricular fibrillation. The current study suggests strong cardioprotective and antiarrhythmic effects for RSV following MIR.

A novel egg shell-based bio formulation for remediation of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) contaminated soil

Environmental contamination by secondary explosive has been posing threat to human health and the ecosystem. We investigated the potential of a novel bioformulation developed from poultry waste for the bioremediation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) contaminated soils. Eggshells and additives immobilized with an indigenous explosive degrading microbe Janibacter cremeus were utilized for the development of the wettable powder bioformulation. Treatments carried out under unsaturated and saturated soil conditions resulted in 62 and 73 % removal of RDX respectively in 35 days meeting the soil clean up goals. The saturated treatment sets exhibited better microbial growth during the study in terms of live cell count and total enzyme activity. The bacteria, J. cremeus was observed to exhibit significant release of nitrite under both unsaturated as well as saturated conditions. Mass spectrometric studies showed that, both the conditions lead to the formation of nitroso-derivatives of RDX. But under saturated condition, an intermediate, 5-hydroxy-4-nitro-2,4-diazapentanal was observed which is a precursor to 4-nitro-2,4-diazabuatnal ultimately leading to mineralization. An accessible bio resource from poultry waste when used as a carrier for explosive degrading microbe has proven effective for in situ remediation of explosive contaminated soils.

Therapeutic Potential of Dental Pulp Stem Cells and Leukocyte- and Platelet-Rich Fibrin for Osteoarthritis.

Osteoarthritis (OA) is a degenerative and inflammatory joint disorder with cartilage loss. Dental pulp stem cells (DPSCs) can undergo chondrogenic differentiation and secrete growth factors associated with tissue repair and immunomodulation. Leukocyte- and platelet-rich fibrin (L-PRF) emerges in regenerative medicine because of its growth factor content and fibrin matrix. This study evaluates the therapeutic application of DPSCs and L-PRF in OA via immunomodulation and cartilage regeneration. Chondrogenic differentiation of DPSCs, with or without L-PRF exudate (ex) and conditioned medium (CM), and of bone marrow-mesenchymal stem cells was compared. These cells showed differential chondrogenesis. L-PRF was unable to increase cartilage-associated components. Immature murine articular chondrocytes (iMACs) were cultured with L-PRF ex, L-PRF CM, or DPSC CM. L-PRF CM had pro-survival and proliferative effects on unstimulated and cytokine-stimulated iMACs. L-PRF CM stimulated the release of IL-6 and PGE2, and increased MMP-13, TIMP-1 and IL-6 mRNA levels in cytokine-stimulated iMACs. DPSC CM increased the survival and proliferation of unstimulated iMACs. In cytokine-stimulated iMACs, DPSC CM increased TIMP-1 gene expression, whereas it inhibited nitrite release in 3D culture. We showed promising effects of DPSCs in an in vitro OA model, as they undergo chondrogenesis in vitro, stimulate the survival of chondrocytes and have immunomodulatory effects.

Lagrangian tracking measurements revealed the temporal dynamics of nitrogen and phosphorus spiralling in a large Japanese river

The in-stream processing of nutrients plays an important role in the fluvial nutrient transport from lands to the ocean, but few empirical studies have addressed the temporal dynamics of net nutrient removal rates in large river systems. The present study applied the recently developed Lagrangian approach to the sixth-order Fuji River to identify the seasonal dynamics of in-stream uptake rates for inorganic nitrogen and phosphorus by tracking a specific water parcel along the river course. The Lagrangian measurements revealed temporal variability of nutrient uptake metrics, but the overall pattern showed a net positive uptake of ammonium (NH4) and a net release of nitrite (NO2) and nitrate (NO3) from the riverbed from May through December. The net uptake rates of phosphate (PO4) showed both positive and negative values depending on the sampling periods. Environmental correlates of the net areal uptake rates (Unet) suggested that biological transformation processes such as assimilation for organic matter synthesis and utilization for energy in oxidation–reduction reactions, as well as abiotic sorption processes, influenced the nutrient removal in the Fuji River. The present study highlights that physical factors (temperature and light), reaction substrates and epilithic organisms may responsible for nutrient dynamics in large river ecosystems.

Study of in vitro biological activity of thiazoles on Leishmania (Leishmania) infantum

ObjectivesIn the prospection of possible agents against neglected diseases, thiazole compounds are presented as promising candidates and are known to have activity against trypanosomatid parasites. Thus, this work aimed to evaluate the effects of thiazole compounds on Leishmania infantum, the aetiological agent of visceral leishmaniasis. MethodsThiazole compounds (five thiazoacetylpyridines [TAPs-01, -04, -05, -06, -09) and five thiazopyridines [TPs-01, -04, -05, -06, -09]) were tested regarding their leishmanicidal activity on both promastigote and amastigote forms of L. infantum. Cytotoxicity was tested using peritoneal macrophages of BALB/c mice. Ultrastructural analyses were performed to identify possible intracellular targets of the most effective compound on promastigote forms. To observe routes that can clarify the possible mechanism of action of the compounds on the intracellular amastigote forms, the nitrite dosage was performed. ResultsAll compounds inhibited the growth of promastigote and presented low cytotoxicity, being more selective to the parasite than to mammalian cells. All compounds tested were able to decrease macrophage infection. There was a significant decrease in the survival rate of the amastigote when compared with the untreated cells, with TAP-04 presenting the best index. TAP-04 induced ultrastructural changes that are related to cell death by apoptosis. None of the macrophage groups infected with L. infantum and subsequently treated showed increased nitrite release. ConclusionsThe low toxicity to mammalian cells and the leishmanicidal activity observed demonstrate that the synthesis of drugs based in thiosemicarbazone nucleus, thiazole and pyridine derivatives are promising for the treatment of visceral leishmaniasis.

Overfeeding During Lactation in Rats is Associated with Cardiovascular Insulin Resistance in the Short-Term.

Childhood obesity is associated with metabolic and cardiovascular comorbidities. The development of these alterations may have its origin in early life stages such as the lactation period through metabolic programming. Insulin resistance is a common complication in obese patients and may be responsible for the cardiovascular alterations associated with this condition. This study analyzed the development of cardiovascular insulin resistance in a rat model of childhood overweight induced by overfeeding during the lactation period. On birth day, litters were divided into twelve (L12) or three pups per mother (L3). Overfed rats showed a lower increase in myocardial contractility in response to insulin perfusion and a reduced insulin-induced vasodilation, suggesting a state of cardiovascular insulin resistance. Vascular insulin resistance was due to decreased activation of phosphoinositide 3-kinase (PI3K)/Akt pathway, whereas cardiac insulin resistance was associated with mitogen-activated protein kinase (MAPK) hyperactivity. Early overfeeding was also associated with a proinflammatory and pro-oxidant state; endothelial dysfunction; decreased release of nitrites and nitrates; and decreased gene expression of insulin receptor (IR), glucose transporter-4 (GLUT-4), and endothelial nitric oxide synthase (eNOS) in response to insulin. In conclusion, overweight induced by lactational overnutrition in rat pups is associated with cardiovascular insulin resistance that could be related to the cardiovascular alterations associated with this condition.

The anti-arrhythmic effects of pomegranate (Punica granatum) are mainly mediated by nitric oxide

BACKGROUND: Pomegranate juice (PJ) contains strong antioxidant polyphenols, and cardiovascular beneficial effects have been reported for the fruit. OBJECTIVE: Using a Langendorff’s model, we hypothesized that PJ has antiarrhythmic effects on isolated rat hearts. METHODS: The hearts in the control group (n = 10) were perfused with Krebs solution. The test groups (n = 10, each) were further perfused with PJ, L-NAME (L), or both (PJL). Following 30 min stabilization, all hearts experienced 30 min global ischemia and 120 min reperfusion. The hearts were monitored for the occurrence of single and salvo arrhythmias, ventricular tachycardia (VT), and ventricular fibrillation (VF). The cardiac release of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and nitrite were measured. In addition, the markers of oxidative stress including superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and malondialdehyde (MDA) were assayed in the homogenates of the hearts. RESULTS: The PJ group showed a significant reduction in the occurrence of arrhythmias, an improvement in redox markers, and a rise in nitrite release, compared to the control. Simultaneous treatment with L-NAME significantly reduced, but not fully abolished, these effects. CONCLUSIONS: The current study suggests strong anti-arrhythmic effects for PJ, which are mainly mediated by nitric oxide.

Enhanced Anti-Inflammatory Effect of Polyherbal Formulation (MKA) Comprising of Three Selected Plants in Lipopolysaccharide (LPS) -Induced Raw 264.7 Macrophage Cell Line

Antiinflammatory potential of Polyherbal formulation comprising of three selected plants Mimusops elengi L., Kedrostis foetidissima (Jacq.) Cogn. and Artemisia vulgaris L. MKA were studied in Lipopolysaccharide induced RAW 264.7 macrophage cell line. Initially, the MTT cell viability assay was performed to assess the safety level of MKA for anti-inflammatory studies. The MKA was studied for its anti-inflammatory property in selected four different concentrations (25µg/ml, 50 µg/ml, 75 µg/ml and 100 µg/ml). It was observed that increase in MKA concentration decreased the nitrite release from Lipopolysaccharide induced macrophage cells. Microscopic analysis also revealed that MKA restored the normal cell morphology by reducing the cell damage caused by Lipopolysaccharide. The intracellular reactive oxygen species was detected by 2’-7’-Dichlorodihydrofluorescein diacetate labelling and flow cytometry. It was found that, MKA decreased the intracellular Reactive oxygen species level in Lipopolysaccharide stimulated macrophages in a dose-dependent manner, which proved its enhanced anti-inflammatory effect.

Curdlan (Alcaligenes faecalis) (1→3)-β-d-Glucan Oligosaccharides Drive M1 Phenotype Polarization in Murine Bone Marrow-Derived Macrophages via Activation of MAPKs and NF-κB Pathways.

Functional oligosaccharides, particularly curdlan (1→3)-β-d-glucan oligosaccharides (GOS), play important roles in modulating host immune responses. However, the molecular mechanisms underlying the immunostimulatory effects of GOS on macrophage polarization are not clear. In this work, GOS (5–1000 µg/mL) were non-toxic to bone marrow-derived macrophages (BMDMs) with improved pinocytic and bactericidal capacities. Incubation with GOS (100 µg/mL) induced M1 phenotype polarization of BMDMs as evidenced by increased CD11c+/CD86+ (10.1%) and M1 gene expression of inducible nitric oxide synthase, interleukin (IL)-1β, and chemokine C-C-motif ligand 2. Accordingly, the secretion of cytokines IL-1β, IL-6, monocyte chemotactic protein-1, and tumor necrosis factor-α, as well as the nitrite release of BMDMs were increased by GOS (100 µg/mL). Expression of mitogen-activated protein kinases (MAPKs) of phosphorylated (p)-c-Jun amino-terminal kinase, p-extracellular signal regulated kinase, and p-p38 in BMDMs were increased by GOS, as well as the p-Stat1. Moreover, nuclear factor-kappa B (NF-κB) p-p65 expression in BMDMs was promoted by GOS while it suppressed IκBα expression. Receptor blocking with anti-CR3 (CD11b/CD18) and anti-toll-like receptor (TLR) 2 antibodies diminished GOS induced M1 phenotype polarization with reduced mRNA expression of M1 genes, decreased cytokine and nitrite releases, and suppressed signaling pathway activation. Thus, CR3 (CD11b/CD18) and TLR2 mediated activation of MAPKs and NF-κB pathways are responsible for GOS induced polarization of BMDMs.

13C and 15N NMR identification of product compound classes from aqueous and solid phase photodegradation of 2,4,6-trinitrotoluene.

Photolysis is one of the main transformation pathways for 2,4,6-trinitrotoluene (TNT) released into the environment. Upon exposure to sunlight, TNT is known to undergo both oxidation and reduction reactions with release of nitrite, nitrate, and ammonium ions, followed by condensation reactions of the oxidation and reduction products. In this study, compound classes of transformation products from the aqueous and solid phase photodegradation of 2,4,6-trinitrotoluene (TNT) have been identified by liquid and solid state 13C and 15N NMR. Aqueous phase experiments were performed on saturated solutions of T15NT in deionized water, natural pond water (pH = 8.3, DOC = 3.0 mg/L), pH 8.0 buffer solution, and in the presence of Suwannee River Natural Organic Matter (SRNOM; pH = 3.7), using a Pyrex-filtered medium pressure mercury lamp. Natural sunlight irradiations were performed on TNT in the solid phase and dissolved in the pond water. In deionized water, carboxylic acid, aldehyde, aromatic amine, primary amide, azoxy, nitrosophenol, and azo compounds were formed. 15N NMR spectra exhibited major peaks centered at 128 to 138 ppm, which are in the range of phenylhydroxylamine and secondary amide nitrogens. The secondary amides are proposed to represent benzanilides, which would arise from photochemical rearrangement of nitrones formed from the condensation of benzaldehyde and phenylhydroxylamine derivatives of TNT. The same compound classes were formed from sunlight irradiation of TNT in the solid phase. Whereas carboxylic acids, aldehydes, aromatic amines, phenylhydroxylamines, and amides were also formed from irradiation of TNT in pond water and in pH 8 buffer solution, azoxy and azo compound formation was inhibited. Solid state 15N NMR spectra of photolysates from the lamp irradiation of unlabeled 2,6-dinitrotoluene in deionized water also demonstrated the formation of aromatic amine, phenylhydroxylamine/ 2° amide, azoxy, and azo nitrogens.

INCORPORATION OF HYBRID BIOFILTERS IN WATER-SENSITIVE URBAN DESIGN

This paper presents a research study aimed at the development of a hybrid biofilter that can serve for two different applications. This is a unique approach due to the prolonged dry period in Israel covering 7-8 months of the year. The tactic suggested herein is to use the same system for stormwater harvesting/treatment during winter, and for bioremediation of nitrate-contaminated groundwater during summer. Crude cotton and Eucalyptus wood-chips served as alternative carbon sources for denitrification, and both proved to support efficient reduction of nitrate with minimal release of nitrite and organic matter. During the stage of stormwater treatment, two types of biofilter-columns (120 & 70 cm long) were tested, with a minimal saturation zone and no addition of organic carbon. Complete nitrification could be achieved, even under high instantaneous hydraulic loads for both column types. Vegetation on top of the biofilters contributed to improved removal of the nitrate formed, by plant assimilation.

Ginsenoside Rg3 reduces the adhesion, invasion, and intracellular survival of Salmonella enterica serovar Typhimurium

BackgroundInvasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. MethodsThe impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. ResultsSubinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on “trigger” entry mechanism and intracellular survival S. Typhimurium. ConclusionRg3 could be considered as a supplement agent to prevent S. Typhimurium infection.