Nitro Oxide Research Articles

Heat- and shock-induced pyrolysis of crystalline and amorphous TNT revealed by ReaxFF-lg simulations

The decomposition mechanisms of crystalline and amorphous TNT were studied through ReaxFF-lg simulations under the heat-loaded and shock-loaded. Their differences were elucidated from the initial decay reactions, activation energy, products and the clusters. Results showed that the heat-induced pyrolysis of two systems differed slight, but the shock-induced pyrolysis differed large. The decomposition reactions of amorphous and crystalline models are similar, but the nitro oxidation of TNT is only found in amorphous. Dimerization and intermolecular H-transfer were found at the constant temperature and MSST simulations, and intermolecular O-transfer were only found at the constant temperature simulations. For MSST simulation, products in crystalline formed later than in amorphous, and the number of clusters in crystalline is much larger than in amorphous, which indicating crystalline TNT would be induced early through shock wave. These findings could help to increase the understanding for the thermolysis behavior and safety of crystalline and amorphous energetic materials.

Virtual screening reveals fluorescent probes for detecting Pan-Zinc center activity in serum MMPs: A potential biomarker for early tumor screening

Early tumor screening is pivotal for enhancing tumor treatment efficacy and patient survival rates, yet identifying reliable biomarkers for early detection remains a challenge. Previous studies have explored different isoforms of matrix metalloproteinases (MMPs) in serum for their predictive value in tumor, but their results have been inconsistent. Herein, we introduce a novel fluorescent probe, C9 (N-oxide-8-hydroxyquinoline-5-sulfonic acid), designed to specifically label the pan zinc center activity of MMPs (PZCA-MMPs), which in a sense represents the overall MMPs activity in serum. The rational design of fluorescent probe C9 is based on its ability to bind the zinc ions in the structure of MMPs, facilitated by the oxides on hydroxyl (–OH) and nitro oxide (N→O) groups present in C9, as supported by theoretical calculations such as Gaussian and Schrödinger. Experimental validation confirmed its efficacy for detecting PZCA-MMPs in vitro and for fluorescence imaging of MMPs’ zinc ions in cellular contexts, validated through absolute integrated fluorescence intensity measurements at 510 nm. We also demonstrated through in vitro fluorescent analysis that neither metal ions nor abundant serum proteins such as albumin (BSA) and other metalloproteins interfere with the signal response of C9. Notably, in comparative analysis of serum samples from healthy controls and breast tumor patients, PZCA-MMPs showed a highly discriminatory area under the ROC curve (AUC) of 0.9377, surpassing established tumor biomarkers such as CA125, CA15-3, CA19-9, and CA72-4. In particular, for tumor patients, PZCA-MMPs can effectively distinguish between metastatic and non-metastatic patients (*P<0.05). Therefore, this provides a potential alternative biomarker for tumor screening. Future studies aim to further elucidate the clinical utility of PZCA-MMPs using a broader spectrum of clinical samples.

Cx40 Levels Regulate Hypoxia-Induced Changes in the Migration, Proliferation, and Formation of Gap Junction Plaques in an Extravillous Trophoblast Cell Model.

Extravillous trophoblasts (EVTs) form stratified columns at the placenta-uterus interface. In the closest part to fetal structures, EVTs have a proliferative phenotype, whereas in the closest part to maternal structures, they present a migratory phenotype. During the placentation process, Connexin 40 (Cx40) participates in both the proliferation and migration of EVTs, which occurs under hypoxia. However, a possible interaction between hypoxia and Cx40 has not yet been established. We developed two cellular models, one with "low Cx40" (Jeg-3), which reflected the expression of this protein found in migratory EVTs, and one with "high Cx40" (Jeg-3/hCx40), which reflected the expression of this protein in proliferative cells. We analyzed the migration and proliferation of these cells under normoxic and hypoxic conditions for 24 h. Jeg-3 cells under hypoxia increased their migratory capacity over their proliferative capacity. However, in Jeg-3/hCx40, the opposite effect was induced. On the other hand, hypoxia promoted gap junction (GJ) plaque formation between neighboring Jeg-3 cells. Similarly, the activation of a nitro oxide (NO)/cGMP/PKG-dependent pathway induced an increase in GJ-plaque formation in Jeg-3 cells. The expression patterns of Cx40 play a crucial role in shaping the responses of EVTs to hypoxia, thereby influencing their migratory or proliferative phenotype. Simultaneously, hypoxia triggers an increase in Cx40 gap junction (GJ) plaque formation through a pathway dependent on NO.

Delivery exogenous nitric oxide via cardiopulmonary bypass in pediatric cardiac surgery reduces the duration of postoperative mechanical ventilation-A meta-analysis of randomized controlled trials

ObjectivesCardiopulmonary bypass (CPB) is a major part of cardiac surgery that provokes systemic inflammatory reactions, myocardial ischemia, and ischemia and reperfusion damage. The aim of this study is to summarize the available evidence and evaluate whether exogenous nitric oxide administered via CPB circuits can improve recovery after cardiac surgery in children. MethodA comprehensive search of the PubMed Medline, Ovid, Cochrane Library and Embase databases was conducted in September 2022. Only randomized controlled trials that compared nitro oxide with placebo or standard care were included. ResultsThis pooled analysis included 5 RCTs containing 1642 patients. There were significant differences in the duration of postoperative mechanical ventilation between the nitric oxide group and the control group (mean difference −5.645 h; 95% CL = −9.978, −1.313; P = 0.01). Meta-analysis of the length of ICU stay and hospital stay showed no significant differences. ConclusionDelivering nitric oxide via CPB in pediatric cardiac surgery has an effect on reducing the duration of mechanical ventilation. Considering the small effect size, we should be cautious and think comprehensively in clinical practice.

Structural-phase transformations during nitro oxidation of steels and surface properties

Structural and phase changes in the surface diffusion layer during gas nitriding of steel were studied, with the formation of a crystallographic structure of the nitride layer for subsequent oxidation in water vapor. The conditions for forming carbides and nitrocarbides with simultaneous diffusion of nitrogen and decarburization of the steel matrix are determined depending on the nitrogen potential of the saturating medium. The structural-phase states of the surface diffusion layer with a stepwise change in the nitrogen potential during nitriding at the first stage and followed by oxidation at the second stage, the formation of a surface oxide layer, as well as the conditions for participation in mutual diffusion processes of carbon in the nitride layer, decarburized from the steel matrix with the formation compositions of modified nitride phases. The nitride-oxide layer’s corrosion properties and gradient properties in various structural-phase states of nitride phase compositions have been studied.

Cell-Free Supernatant from Lactobacillus and Streptococcus Strains Modulate Mucus Production via Nf-κB/CREB Pathway in Diesel Particle Matter-Stimulated NCI-H292 Airway Epithelial Cells.

Airway epithelial cells are a major site of airway inflammation and may play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Diesel particulate matter (DPM) is associated with mucus hypersecretion and airway inflammation and has been reported to overexpress airway mucin in the NCI-H292 airway epithelial cells. Therefore, regulation of mucin hypersecretion is essential for developing novel anti-inflammatory agents. This study aimed to investigate the effects of cell-free supernatant (CFS) from Lactobacillus and Streptococcus on nitro oxide (NO) production in RAW264.7 and proteins associated with mucus production in NCI-H292 cells. We observed that NO production was reduced by CFS from Lactobacillus and Streptococcus in RAW 264.7, and MUC4, MUC5AC, and MUC5B gene expression was increased by phosphorylation of nuclear factor kappa B (NF-κB) p65 and cAMP response element-binding protein (CREB) in DPM-stimulated NCI-H292 cells. However, CFS from L. paracasei MG4272, MG4577, L. gasseri MG4247, and S. thermophilus MG5140 inhibited mRNA expression related to mucus production by downregulating the CREB/NfκB signaling pathway. These results suggest that CFS from L. paracasei MG4272, MG4577, L. gasseri MG4247, and S. thermophilus MG5140 can contribute as a strategic candidate to the prevention of airway inflammatory diseases caused by DPM.

Renal Farnesoid X Receptor improves high fructose-induced salt-sensitive hypertension in mice by inhibiting DNM3 to promote nitro oxide production.

Farnesoid X Receptor (FXR) is highly expressed in renal tubules, activation of which attenuates renal injury by suppressing inflammation and fibrosis. However, whether renal FXR contributes to the regulation of blood pressure (BP) is poorly understood. This study aimed to investigate the anti-hypertensive effect of renal FXR on high-fructose-induced salt-sensitive hypertension and underlying mechanism. Hypertension was induced in male C57BL/6 mice by 20% fructose in drinking water with 4% sodium chloride in diet (HFS) for 8 weeks. The effects of FXR on NO production were estimated in vitro and in vivo . Compared with control, HFS intake elevated BP, enhanced renal injury and reduced renal NO levels as well as FXR expression in the kidney of mice. In the mouse renal collecting duct cells mIMCD-K2, FXR agonists promoted NO production by enhancing the expression of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS), whereas this effect was diminished by fxr knockdown. We further found that Dynamin 3 (DNM3), a binding protein with nNOS in the renal medulla, was inhibited by FXR and its deficiency elevated NO production in mIMCD-K2 cells. In HFS-fed mice, renal fxr overexpression significantly attenuated hypertension and renal fibrosis, regulated the expression of DNM3/nNOS/iNOS, and increased renal NO levels. Our results demonstrated that renal FXR prevents HFS-induced hypertension by inhibiting DNM3 to promote NO production. These findings provide insights into the role and potential mechanism of renal FXR for the treatment of hypertension.

Design, synthesis, in vitro and in silico bioactivity profiles of new urea/thiourea derivatives of 2-pyridyl piperazine as potent antioxidant and antimicrobial agents: chemo-bio-computational approach

Synthesis of a series of new urea and thiourea derivatives of 2-pyridyl piperazine was accomplished by reacting various isocyanates and isothiocyanates in the presence of triethylamine (TEA) at 50 °C. All the title compounds were obtained in high yields and their structures were characterized by IR, 1H, 13C NMR, Mass spectral, and Elemental analysis. The synthesized compounds were screened for in vitro and in silico antioxidant and antimicrobial activities. All the title compounds exhibited potent antioxidant and antimicrobial activities. Out of all, 2c and 2f against DPPH, H2O2 and Nitro oxide have exhibited significant activity and the levels of activity were higher than the reference compounds, ascorbic acid and BHT. Whereas 2a, 2c, 2f and 2j have shown prominent activity in terms of zone of inhibition against all the microbial strains tested than the standards such as levofloxacin and nystatin. In addition in silico studies also conveyed the same that is 2a, 2c, 2f and 2j have displayed the highest binding energies against peroxiredoxins and DNA gyrase protein than the standards akin to the rest of the compounds. In overall, 2c and 2f have exhibited most promising antioxidant and antimicrobial activity than the rest of the title compounds in vitro and in silico. Hence, 2c and 2f will stand as a lead and promising antioxidant and antimicrobial drug candidates in future. Communicated by Ramaswamy H. Sarma

The effect of S/N ratio on NO and N2O accumulation during sulfide autotrophic denitrification

Nitro oxide (NO) and Nitrous oxide (N2O) are inevitable intermediates of sulfide autotrophic denitrification (SAD) process, and have huge environmental hazard. This study investigated the produce mechanism and accumulation characteristic of NO and N2O in SAD process under different S/N ratios. The results showed that the lower S/N ratio, the higher NO accumulation. Which was due to the strong reducing effect of S2- and the electronic competition between nitrogen reductase. And under S/N ratio = 2, N2O level reached its peak, which was caused by electronic competition. When the S/N ratio = 1, although the electronic competition was more intense, the total amount of electrons was less, thus the N2O produced is lower than that produced when S/N=2. Microbial community analysis showed that Thiobacillus sp. (62.44%) was the predominant genus, and conducted the suldide-oxiding autotrophic denitrification process.

Azilsartan ameliorates ox-LDL-induced endothelial dysfunction via promoting the expression of KLF2.

Background: Oxidized LDL(Ox-LDL) mediated endothelial dysfunction is involved in the pathogenesis of various cardiovascular diseases, including atherosclerosis. Azilsartan is a potent agent for the treatment of hypertension as the antagonist of the angiotensin II receptor. This study will investigate whether Azilsartan possesses a beneficial effect against endothelial cell dysfunction induced by ox-LDL and explore the underlying preliminary mechanism.Methods: Ox-LDL was applied to construct an in vitro endothelial dysfunction model in human umbilical vascular endothelial cells (HUVECs). The expression of lectin-type oxidized LDL receptor 1 (LOX-1), endothelial nitric oxide synthase (eNOS), tight junction protein occludin, and transcriptional factor Krüppel-like factor 2 (KLF2) was detected using qRT-PCR and Western blot. ELISA and qRT-PCR were utilized to evaluate the production of chemokine monocyte chemotactic protein 1 (MCP-1) and chemokine (C-X-C motif) Ligand 1 Protein (CXCL1) in treated HUVECs. The generation of nitro oxide (NO) was determined using DAF-FM DA staining assay. KLF2 was silenced by transfecting the cells with specific Small interfering RNA (siRNA). FITC-dextran permeation assay was used to check the endothelial monolayer permeability of treated HUVECs.Results: Firstly, the elevated expressions of LOX-1, MCP-1, and CXCL-1 induced by stimulation with ox-LDL were significantly suppressed by Azilsartan. The downregulated eNOS and reduced production of NO induced by ox-LDL were reversed by the introduction of Azilsartan. Secondly, enlarged endothelial monolayer permeability and decreased expression of occludin stimulated with ox-LDL were greatly reversed by treatment with Azilsartan but were abolished by silencing the expression of KLF2. Lastly, the inhibited expression of KLF2 induced by ox-LDL was significantly elevated by the introduction of Azilsartan.Conclusion: Azilsartan might ameliorate ox-LDL-induced endothelial damage via elevating the expression of KLF2.

A novel fluorescence sensor for relay recognition of zinc ions and nitric oxide through fluorescence ‘off–on–off’ functionality

The fluorescent ‘off–on–off’ probe for relay recognition of Zn2+ and nitro oxide (NO) was constructed with the detection limit of 10−8 mol L−1.

Bile acids aggravate nonalcoholic steatohepatitis and cardiovascular disease in SHRSP5/Dmcr rat model

Background and aimsNonalcoholic steatohepatitis (NASH) is linked to an increased risk of cardiovascular disease, regardless of the risk factors in metabolic syndrome. However, the intermediary factors between NASH and cardiovascular disease are still unknown. A previous study revealed that serum and hepatic bile acid (BA) levels are increased in some NASH patients. We aimed to examine whether NASH and cardiovascular disease were aggravated by BA using an animal model. Method and resultsFrom 10 to 18 weeks of age, SHRSP5/Dmcr rats divided into 3 groups were fed 3 types of high-fat and high-cholesterol (HFC) diets which were changed in the cholic acid (CA) concentration (0%, 2%, or 4%). The nitro oxide synthase inhibition (L-NAME) was administered intraperitoneally from 16 to 18 weeks of age. The 4% CA groups showed the worst LV dysfunction and myocardial fibrosis, and demonstrated severe hepatic fibrosis and lipid depositions. In addition, a large amount of lipid accumulation was observed in the aortas of the 4% CA group, and NFκB and VCAM-1 gene expression levels were increased. These findings were not seen in the 0% CA group. ConclusionIn the SHRSP5/Dmcr rat model, NASH and cardiovascular disease were aggravated with increasing BAs concentrations in an HFC diet.

The vascular dilatation induced by Hydroxysafflor yellow A (HSYA) on rat mesenteric artery through TRPV4-dependent calcium influx in endothelial cells

Ethnopharmacological relevanceHydroxysafflor yellow A (HSYA) is the principal constituent of the flowers of Carthamus tinctorius L., a traditional Chinese herbal medicine, which has been used for the treatment of cerebrovascular and cardiovascular diseases due to its property of promoting blood circulation and removing blood stasis. It is dominated in the water extract of Carthamus tinctorius L., which has been used in the clinical treatment for cardiovascular diseases. HSYA exerts a variety of pharmacological efficacy upon the vascular system. However, the underlying mechanisms remain unclear. Aim of the studyTo investigate the vascular dilatation effect of HSYA on rat mesenteric artery (MA) and its potential mechanism. Materials and methodsAdult male Wistar rats were applied to the study. Tension studies were conducted to determine the dilatation activity of HSYA against pre-contracted mesenteric arterial (MA) rings by U 46619 and Phenylephrine (PE). The vascular activities were measured with or without incubation with some selective inhibitors, including L-N(ω)-nitro-L-arginine methyl ester (L-NAME, a nitro oxide synthase inhibitor), HC-067047 (a selective TRPV4 antagonist), BaCl2 (a Kir channel blocker), and Indomethacin (Indo, a nonselective cyclooxygenase inhibitor), respectively. Immunocytochemistry, Calcium Imaging, NO Production detection, and Western Blot were also employed to further study the underlying mechanism. ResultsHSYA reversed the constriction of MAs induced by U 46619 in a manner of concentration dependency, and the dilatation capability was reversed by L-NAME. This effect was significantly dependent on the intactness of MA endothelium, accompanying an increment of NO production in mesenteric arterial endothelium cells. The increment of NO production was reversed by inhibiting the PKA. Also, the expression of p-eNOS was activated by HSYA shown in Western Blot assays. The cells imaging revealed a significant increase and drop of the influx of Ca2+ before and after treatment with HC-067047. ConclusionsThese findings suggest that HSYA exerts vessel dilation effect on MAs via a TRPV4-dependent influx of Ca2+ in endothelium cells, PKA-dependent eNOS phosphorylation and NO production mechanism. The present study indicates that HSYA has the potential to be a future candidate for the treatment of hypertension.

Theobromine mitigates IL-1β-induced oxidative stress, inflammatory response, and degradation of type II collagen in human chondrocytes

Osteoarthritis is one of the major causes of disability in elderly adults. Chondrocytes are responsible for the formation and remodeling of articular cartilage in joint tissue. The dysfunction of chondrocytes is a significant factor in the development of osteoarthritis. In the current study, we found that theobromine, a constituent of the cacao plant, possesses a preventive effect against interleukin (IL)-1β-induced chondrocyte dysfunction. Theobromine ameliorates IL-1β-induced production of cellular reactive oxygen species (ROS) and inflammatory mediators including cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). The presence of theobromine suppresses IL-1β-induced inducible nitro oxide synthase (iNOS) expression and cellular nitro oxide (NO) production. Theobromine also suppresses IL-1β-induced production of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1), as well as matrix metalloproteinases (MMP)-3 and MMP-13. Additionally, theobromine mitigates IL-1β-induced type II collagen degradation. Mechanistically, we show that theobromine inhibits IL-1β-induced IκBα activation, nuclear factor-κB (NF-κB) protein p65 accumulation, and transfected NF-κB promoter activity, indicating that theobromine suppresses the NF-κB pathway in chondrocytes. Collectively, our study demonstrates that the natural molecule theobromine has a protective effect to counter cytokine-induced chondrocyte dysfunction, implying its beneficial effect in the prevention of osteoarthritis.

Rice Protein Exerts Anti-Inflammatory Effect in Growing and Adult Rats via Suppressing NF-κB Pathway.

To elucidate the effect of rice protein (RP) on the depression of inflammation, growing and adult rats were fed with caseins and RP for 2 weeks. Compared with casein, RP reduced hepatic accumulations of reactive oxygen species (ROS) and nitro oxide (NO), and plasma activities of alanine transaminase (ALT) and aspartate transaminase (AST) in growing and adult rats. Intake of RP led to increased mRNA levels, and protein expressions of phosphoinositide 3 kinase (PI3K), protein kinase B (Akt), nuclear factor-κB 1 (NF-αB1), reticuloendotheliosis viral oncogene homolog A (RelA), tumor necrotic factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and monocyte chemoattractant protein-1 (MCP-1) were decreased, whereas hepatic expressions of interleukin-10 (IL-10) and heme oxygenase 1 (HO-1) were increased by RP. The activation of NF-κB was suppressed by RP through upregulation of inhibitory κB α (IκBα), resulting in decreased translocation of nuclear factor-κB 1 (p50) and RelA (p65) to the nucleus in RP groups. The present study demonstrates that RP exerts an anti-inflammatory effect to inhibit ROS-derived inflammation through suppression of the NF-κB pathway in growing and adult rats. Results suggest that the anti-inflammatory capacity of RP is independent of age.

The Impact of Climate Change on Pakistan's Agriculture sector: Evidence from OLS Regression &amp; Co-integration

Abstract: According to Ministry of Finance of Pakistanin the year 2016-17, agriculture sector contributed to GDP 19.8% and employees about 42.3% a labor force in country. Pakistan has been ranked 7th in climate change by theGlobal climate rise index in 2017, this rank indicates a great challenge for the Pakistan in agriculture sector due to further climate change in future.There are few gases such as greenhouse gases, CO2, carbon dioxide, methane and nitro oxide that mainly are responsible for changes to global climate. The climate change leads to change in rainfall, sea level and flow of water due to increase in temperature. There are many variables which may affect output of agriculture sector of Pakistan but in this study author mainly focused temperature and rainfall in terms of climate change. This study is based on secondary data from year 2000 to 2015.The monthly data of temperature and rainfall has been collected from world economic indicator and 12 months’ data was divided for converting these variables into average. Agriculture GDP output collected from Economic Survey of Pakistan’s various annual issues. Agriculture GDP output in terms of percentage, average rainfall mm andaverage temperature in centigradevariables have been used for the conclusion ofmain objective of this study.Data analyzed through various statistical techniques such as unit root test, OLS regression analysis and Johnson co-integration in E-view 7 version.The estimated results revealed that theaverage rainfall mm has negative and significant impact but average temperature has positive and insignificant impact on agriculture GDP output in terms of percentage in short run.

Effect of Addition of Urea and Zeolite on Rice Plants (Oryza sativa L.) for The Nitroxy Emissions on Peatlands

The purpose of this study is to analyze nitro oxide emissions as a result of adding urea and zeolite to rice plants (Oryza sativa L.) on peatlands. The treatments used were 2 factors, namely factor 1 using a dose of urea fertilizer from three levels of treatment N1 : 125 kg/ha; N2 : 250 kg/ha; N3 : 375 kg/ha and factor 2, the dose of zeolite consists of three levels of treatment Z1 : 125 kg/ha; Z2 : 250 kg/ha; Z3 : 375 kg/ha. Each combination was repeated as many as 5 phases (phase 1 = 15 DDP, phase 2 = 35 DDP, phase 3 = 55 DDP, phase 4 = 65 DDP and phase = 90 DDP) so the number of units treatment 3 x 3 x 5 = 45 pots. Data analysis used linear regression test. The results showed the administration of a combination of urea doses and zeolite in rice plantations had not significant effect on nitrous oxide emissions produced at each observation. In this study, the highest nitrous oxide emissions were obtained in phases 1 and 2. From the results of the F test is Ho rejected. With this it is proven that the urea dose partially has not significant effect on nitro oxide emissions. The dose of zeolite (X2) is H0 is rejected, thus showing that zeolite has not significant effect on the availability of nitrous oxide emissions. Keywords: Urea, Zeolite, Nitro oxide emissions peatlands

An isoxazole-accelerated nitro oxidation type fluorescent detection and imaging for hydrogen sulfide in cells

Hydrogen sulfide (H2S) emerges as an important mediator of human physiology and pathology but remains difficult to study, so it is urgent to find a sensor with high selectivety and rapidly response to detect H2S. The detection mechanism of H2S is various, and the reduction of nitro has developed rapidly in recent years. However, the reported nitro-based H2S probes still have drawback such as slow response. In this work, we introduced isoxazole to strengthen the oxidizability of nitro group, resulted in the response time significantly reduced within 55 s. In addition, this probe could be used to detect and imaging exogenous/endogenous H2S in HepG-2 cells.

Effect of Exogenous Nitro Oxide on Chilling Tolerance, Polyamine, Proline, and γ-Aminobutyric Acid in Bamboo Shoots (Phyllostachys praecox f. prevernalis).

The effects of exogenous nitro oxide (NO) on chilling resistance and the metabolism of polyamine, proline, and γ-aminobutyric acid of bamboo shoots were investigated. Bamboo shoots were dipped in 0.07 mM sodium nitroprusside (SNP) and stored at 1 °C for 56 days. During the storage, the development of chilling injury of SNP treated bamboo shoots was inhibited with decreased accumulation of malonaldehyde and electrical leakage. At the end of storage, the chilling injury incidence of treated bamboo shoots decreased by 37.9% while their malonaldehyde content and electrical leakage were 8.8% and 18.6% lower than that of the control, respectively. Interestingly, the endogenous NO, polyamines, γ-aminobutyric acid, and proline contents of treated bamboo shoot also significantly increased. Consistently, the metabolisms of these nitrogenous compounds were stimulated in treated bamboo shoots, according to their higher (20.2%-49.8%) related enzyme activities, including nitric oxide synthase, arginine decarboxylase, ornithine decarboxylase, glutamate decarboxylase, orn-δ-aminotransferase, and Δ1-pyrroline-5-carboxylate synthetase. The results indicated that the SNP treatment enhanced chilling tolerance of bamboo shoots, which might associate with the activated metabolism of polyamines, γ-aminobutyric acid, and proline. SNP treatment might be an alternative technology to avoid chill injury during cold storage of bamboo shoots.

Vasodilation effect of volatile oil from Allium macrostemon Bunge are mediated by PKA/NO pathway and its constituent dimethyl disulfide in isolated rat pulmonary arterials

The present study aimed to investigate the vasodilation effects of Allium macrostemon Bunge (AMB) on isolated rat pulmonary arterials (PAs) and to assess the underling mechanisms. The volatile oil was extracted by steam distillation from the bulbs of AMB. Then the volatile oil from AMB was studied on isolated rat PA, removal of endothelium, or pretreatment with nitro oxide (NO) synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME), or with protein kinase A (PKA) inhibitor PKI but not cyclooxygenase inhibitor indomethacin significantly blocked the AMB induced relaxation on PE-contracted PA rings. AMB increased the phosphorylation level of NOS in a dose and time-dependent manner, which was through PKA activation. AMB dose-dependently increased the [Ca2+]i through Ca2+ influx in cultured pulmonary artery endothelial cells. A total of 18 components from the volatile oil of AMB were identified. The principle constituents of AMB, Dimethyl Disulfide (DMDS) but not Dimethyltrisulfide displayed dilation effects in PAs. Our results suggest that AMB induces relaxation in rat PAs via an endothelium-dependent mechanism involving Ca2+ entry, PKA dependent NOS phosphorylation and NO signaling. The vasodilator activities of AMB may through its constituent DMDS. The present study indicates therapeutic potentials of AMB on pulmonary hypertension.