Effects Of Sodium Nitroprusside Research Articles

In Vitro Propagation of Alyssum Species with Different Metal Accumulation Strategies.

The Alyssum genus, with its many metal-adapted species, is a good candidate for research on phytoremediation and metal tolerance mechanisms. These goals can be supported by elaborating on an in vitro multiplication protocol. Our study aimed to determine the aseptic conditions for the growth and effective propagation of Alyssum murale, A. alyssoides, and A. montanum, each exhibiting different adaptation strategies to nickel ions. Firstly, hydrogen peroxide (H2O2) or sodium nitroprusside (SNP) were investigated in the biological Lepidium test to find their optimal concentrations that could improve the germination attributes of tested Alyssum species. The concentration of 0.5 mM H2O2 or SNP was selected for research on Alyssum seeds, which were the initial material to start in vitro cultivation. Regardless of the species, H2O2 harmed germination percentage; however, its application accelerated radicle emergence, especially in metal-sensitive genotypes, while in both metal-tolerant ones, the germination time of H2O2-treated seeds was similar to that of treated with SNP. These findings provide a novel insight into the effect of H2O2 or SNP on seeds, contributing to a better understanding of their role in the germination of different genotypes. Among tested media compositions, the synchronous plant regeneration of all species was achieved on MS medium supplemented with 0.5 mg/L 2iP and 0.1 mg/L IAA, making an essential advancement in the in vitro protocols for metallophytes.

Effects of SNP, MgSO4, and MgO-NPs foliar application on Spinacia oleracea L. growth and physio-biochemical responses under cadmium stress

The effects of foliar application of sodium nitroprusside (SNP), magnesium sulfate (MgSO4) and magnesium oxide nanoparticles (MgO-NPs) on the growth, physiology, and gas exchange parameters of two varieties of spinach (Spinacia oleracea L.) under cadmium (Cd) stress were examined. The experiment was arranged in a completely randomized design with 72 pots. Two varieties of S. oleracea (Desi Palak & Lahori Palak) were used. Two concentrations of Cd (0 µM and 150 µM) in the form of cadmium chloride (CdCl2) were used. Two levels of SNP (0 ppm and 100 ppm) and two levels for each form of Mg i.e. MgSO4 and MgO-NPs (0 and 200 ppm) were foliar sprayed on plants in control and Cd stress. Both varieties behaved similarly under Cd stress and caused reductions in growth, physiology, gas exchange, water content parameters and inorganic ion uptake. However, the biochemical parameters like relative membrane permeability (RMP), malondialdehyde (MDA), and hydrogen peroxide (H2O2) contents were increased. However, all foliar spray treatments increased growth, physiological and gas exchange parameters, water content and inorganic ion uptake. However, this reduced the MDA, RMP, and H2O2 contents. Desi Palak showed the more positive results under foliar application of MgO-NPs. However, Lahori palak showed more positive results under the SNP + MgO-NP treatment. It is concluded that foliar application of SNP, MgSO4 and MgO-NPs could be an innovative approach to alleviated the heavy metals (Cd) toxicity in crop plants.

Effects of sodium nitroprusside foliar application on the growth characteristics and nutrient elements in some grapevine cultivars and rootstocks under salt stress conditions

Grape is a staple crop in many parts of Iran which has shown moderate sensitivity to salinity stress. Water and soil salinity is one of the major environmental stresses that strongly affect the production of agricultural products, including grapes. To overcome the harmful effects of salinity, different methods and materials are used, one of which is the use of nitric oxide. In order to explore the impact of nitric oxide on the mitigation of the negative effects of salinity stress on four grape cultivars and rootstocks (‘Bidaneh Sefid’ (Sultana) and ‘Yaghouti’ cultivars, and 140Ru and 1103 P rootstocks), a pot experiment was performed in a factorial based on a randomized complete block design with three replications. Plants were subjected to three sodium chloride (NaCl) levels of 0 (control), 25, and 50 mM and three levels of sodium nitroprusside (SNP) of 0 (control), 0.5, and 1 mM. Results indicated that increasing SNP concentration caused an increase in growth indices such as leaf area, shoot and root length, fresh and dry weights of leaves, shoots, and roots, and leaf relative water content (RWC). Furthermore, salinity decreased the concentrations of potassium (K+), calcium (Ca2+), magnesium (Mg2+), and iron (Fe2+) in leaves, while increased the amount of sodium (Na+) and chlorine (Clˉ) as well as the electrolyte leakage (EL). In addition, SNP at 0.5 and 1 mM could increase the growth efficiency and RWC as well as the elements such as K+ and Mg2+ while decreased the absorption of Na+ and Clˉ as well as the EL in plants under salinity. According to the obtained results, SNP at both concentrations (0.5 and 1 mM) had a pronounced effect on reducing the negative effect of salinity in the evaluated grape rootstocks and cultivars. In general, the positive effects of SNP on ‘Yaghouti’ and ‘Bidaneh Sefid’ cultivars were higher than those on 140Ru and 1103 P rootstocks.

Effects of Sodium Nitroprusside on Lipopolysaccharide-Induced Inflammation and Disruption of Blood–Brain Barrier

In various neurodegenerative conditions, inflammation plays a significant role in disrupting the blood–brain barrier (BBB), contributing to disease progression. Nitric oxide (NO) emerges as a central regulator of vascular function, with a dual role in inflammation, acting as both a pro- and anti-inflammatory molecule. This study investigates the effects of the NO donor sodium nitroprusside (SNP) in protecting the BBB from lipopolysaccharide (LPS)-induced inflammation, using bEnd.3 endothelial cells as a model system. Additionally, Raw 264.7 macrophages were employed to assess the effects of LPS and SNP on their adhesion to a bEnd.3 cell monolayer. Our results show that LPS treatment induces oxidative stress, activates the JAK2/STAT3 pathway, and increases pro-inflammatory markers. SNP administration effectively mitigates ROS production and IL-6 expression, suggesting a potential anti-inflammatory role. However, SNP did not significantly alter the adhesion of Raw 264.7 cells to bEnd.3 cells induced by LPS, probably because it did not have any effect on ICAM-1 expression, although it reduced VCAM expression. Moreover, SNP did not prevent BBB disruption. This research provides new insights into the role of NO in BBB disruption induced by inflammation.

The effect of sodium nitroprusside on the vegetative development of Aronia melanocarpa [Michx.] Elliot under in vitro conditions

Aronia is a berry fruit that has a significant amount of antioxidants. Both sexual and vegetative methods of propagation are available for aronia. Genetic diversity is present in the process of seed propagation. Therefore, clonal propagation techniques such as cuttings, basal shoots, and tissue culture are preferred. Plant tissue culture is a process that offers a high multiplication rate and the ability to produce clean plant material. This study aimed to stimulate the growth of plantlets by introducing several growth-promoting agents into the culture media. Specifically, the effects of a nitric oxide donor SNP (sodium nitroprusside) on the vegetative development of the plants were examined under in vitro conditions. Four distinct concentrations of SNP (0, 100, 200, and 300 µM) were administered to promote vegetative development. The survival rate (%), rooting rate (%), root number (per plantlet), root length (cm), leaf number (per plantlet), shoot length (cm), plant fresh weight (g), and plant dry weight (g) of the plantlets were estimated on the 60th day of growth in the nutrient medium under in vitro conditions. The survival rate was 100% for the applications of SNP at concentrations of 100 µM and 200 µM. The 0 µM treatment had the highest root number, the 100 µM treatment had the longest root, and the 200 µM treatment had the highest values for shoot length. The 0 µM treatment provided the highest values for plant fresh weight, while the 0 and 100 µM applications resulted in the highest plant dry weight values. The study suggested that an increased concentration of SNP causes a toxic effect.

Transcriptomic and physiological analysis of the response of Spirodela polyrrhiza to sodium nitroprusside

BackgroundSpirodela polyrrhiza is a simple floating aquatic plant with great potential in synthetic biology. Sodium nitroprusside (SNP) stimulates plant development and increases the biomass and flavonoid content in some plants. However, the molecular mechanism of SNP action is still unclear.ResultsTo determine the effect of SNP on growth and metabolic flux in S. polyrrhiza, the plants were treated with different concentrations of SNP. Our results showed an inhibition of growth, an increase in starch, soluble protein, and flavonoid contents, and enhanced antioxidant enzyme activity in plants after 0.025 mM SNP treatment. Differentially expressed transcripts were analysed in S. polyrrhiza after 0.025 mM SNP treatment. A total of 2776 differentially expressed genes (1425 upregulated and 1351 downregulated) were identified. The expression of some genes related to flavonoid biosynthesis and NO biosynthesis was upregulated, while the expression of some photosynthesis-related genes was downregulated. Moreover, SNP stress also significantly influenced the expression of transcription factors (TFs), such as ERF, BHLH, NAC, and WRKY TFs.ConclusionsTaken together, these findings provide novel insights into the mechanisms of underlying the SNP stress response in S. polyrrhiza and show that the metabolic flux of fixed CO2 is redirected into the starch synthesis and flavonoid biosynthesis pathways after SNP treatment.

Asparagine and nitric oxide jointly enhance antioxidant capacity and nitrogen metabolism to improve drought resistance in cotton: Evidence from long‐term field trials

AbstractAsparagine (Asn) and nitric oxide (NO) can enhance plant tolerance to abiotic stress, but their interaction is not well understood. Cotton is a vital resource for the textile industry, but its yield is reduced by drought stress, which could threaten its global supply in a warming and stressful world. Improving cotton's drought tolerance is crucial for supporting the textile industry. Two simultaneous field experiments were conducted to study the effect of Asn and sodium nitroprusside (SNP), a NO donor, on cotton's drought tolerance. Two irrigation treatments were applied: control (C: 100% A pan) and drought stress (50% A pan). The plants were also sprayed with two plant stimulants before imposing drought stress: Mock control, 20 mM Asn, and 0.2 mM SNP, either alone or together. Drought stress impaired plant growth, photosynthesis, yield, nitrogen metabolism, and antioxidant defense, while increasing oxidative stress and free amino acid levels. However, Asn and SNP treatments alleviated these negative effects and improved antioxidant enzyme activity, plant growth, yield, and nitrogen content. The Asn + SNP treatment also increased irrigation water productivity under water‐limited conditions, suggesting its potential for enhancing water use efficiency in cotton production. The combined treatment was more effective than the single treatments, indicating a synergistic effect of Asn and SNP in enhancing drought tolerance in cotton. These results imply that Asn and SNP could be useful tools for sustaining cotton production under drought conditions by boosting nitrogen metabolism and antioxidant defense, thereby contributing to the global supply of cotton and supporting the textile industry.

Synthesis and secretion of Nerve Growth Factor is regulated by Nitric Oxide in bladder cells in vitro under a hyperglycemic environment

Urine samples of female patients with overactive bladder (OAB) are characterized by low levels of nerve growth factor (NGF) and elevated concentrations of nitric oxide (NO) compared to healthy controls. We therefore examined how NO might regulate NGF synthesis using rat bladder smooth muscle (SMCs) and urothelial (UROs) cells in culture. In UROs, incubation in hyperglycemic conditions to mimic insulin insensitivity present in the OAB cohort increased secretion of NO and concomitantly decreased NGF, except when the NO synthase inhibitor, l-NAME (1 mM) was present. Sodium nitroprusside (SNP) (300 μM, 24 h), a NO generator, decreased NGF levels and decreased cyclic GMP (cGMP) content, a process validated by the cGMP synthase inhibitor ODQ (100 μM). Alternatively, SNP increased mRNA of both NGF and matrix metalloproteinase-9 (MMP-9). MMP-9 knockout of UROs by Crispr-Cas9 potently decreased the effect of SNP on NGF, implying a dependent role of NO on MMP-9. On the other hand, matrix metalloproteinase-7 (MMP-7) activity was increased by SNP, which taken together with increase in NGF mRNA, suggests a compensatory mechanism. In SMCs, hyperglycemic conditions had the same effect on extracellular content of NO and NGF than in UROs. SNP also decreased NGF secretion but increased cGMP content. Stable permeable analogs of cGMP 8-(4-Chlorophenylthio)-cGMP (1 mM) and N2,2′-O-Dibutyryl-cGMP (3 mM) inhibited NGF release. NGF and MMP-9 mRNA expression was unchanged by SNP. Deletion of MMP-9 in SMCs by Crispr-Cas9 did not alter the effect of SNP. Finally, SNP decreased MMP-7 activity, diminishing the conversion of proNGF to NGF. These results demonstrate that enhanced NO secretion triggered by high glucose decreases NGF secretion through pathways unique for each cell type that involve cGMP and proteases MMP-7 and MMP-9. These results might help to explain our observations from the urine from patients with OAB associated with metabolic syndrome.

Desipramine induces eryptosis in human erythrocytes, an effect blunted by nitric oxide donor sodium nitroprusside and N-acetyl-L-cysteine but enhanced by Calcium depletion

ABSTRACT Background: Desipramine a representative of tricyclic antidepressants (TCAs) promotes recovery of depressed patients by inhibition of reuptake of neurotransmitters serotonin (SER) and norepinephrine (NE) in the presynaptic membrane by directly blocking their respective transporters SERT and NET. Aims: To study the effect of desipramine on programmed erythrocyte death (eryptosis) and explore the underlying mechanisms. Methods: Phosphatidylserine (PS) exposure on the cell surface as marker of cell death was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry. Hemolysis was determined photometrically, and intracellular glutathione [GSH]i from high performance liquid chromatography. Results: Desipramine dose-dependently significantly enhanced the percentage of annexin-V-binding cells and didn´t impact glutathione (GSH) synthesis. Desipramine-induced eryptosis was significantly reversed by pre-treatment of erythrocytes with either nitric oxide (NO) donor sodium nitroprusside (SNP) or N-acetyl-L-cysteine (NAC). The highest inhibitory effect was obtained by using both inhibitors together. Calcium (Ca2+) depletion aggravated desipramine-induced eryptosis. Changing the order of treatment, i.e. desipramine first followed by inhibitors, could not influence the inhibitory effect of SNP or NAC. Conclusion: Antidepressants-caused intoxication can be treated by SNP and NAC, respectively. B) Patients with chronic hypocalcemia should not be treated with tricyclic anti-depressants or their dose should be noticeably reduced.

Mitigation of heat stress in wheat (Triticum aestivum L.) via regulation of physiological attributes using sodium nitroprusside and gibberellic acid

Heat stress poses a threat to plants in arid and semiarid regions, leading to soil salinization and plant mortality. Researchers are exploring remedies to alleviate these effects, including using gibberellic acid (GA3) to regulate plant enzymes and antioxidants. Additionally, sodium nitroprusside (SNP) is gaining attention, but its combined effect with GA3 requires further research. To address this gap, we investigated the effects of GA3 and SNP on plants under heat stress conditions. For that, wheat plants were cultivated under 40 °C for 6 h per day (15 days). Sodium nitroprusside (donor of NO and SNP) and gibberellic acid (GA3), respectively, with 100 µM and 5 µg/ml concentrations, were applied as foliar sprays at 10 days after sowing (DAS). Results showed that SNP + GA3 treatment had the highest plant height (4.48% increase), plant fresh weight (29.7%), plant dry weight (87%), photosynthetic rate (39.76%) and stomatal conductance (38.10%), and Rubisco (54.2%) compared to the control. Our findings indicate a significant increase in NO, H2O2, TBARS, SOD, POD, APX, proline, GR, and GB that greatly scavenged reactive oxygen species (ROS) for decreasing the adverse effect of stress. Such findings confirmed the efficacy of the combined treatment of SNP + GA3 under high-temperature stress compared to the solitary application of GA3, SNP, and control. In conclusion, using SNP + GA3 is a better strategy for mitigating heat stress in wheat than individual applications. Further research is recommended to validate the effectiveness of SNP + GA3 in other cereal crops.Graphical

P284 POTENTIAL PROARRHYTHMIC SIDE EFFECT OF HIGH DOSE AND PROLONGED SODIUM NITROPRUSSIDE INFUSION THROUGH CALCIUM ION REDUCTION

Abstract Patient presentation. A fifty y/o male patient with a history of congenital aortic stenosis surgically corrected previously and with chronic heart failure due to severe left ventricular dysfunction presented to our emergency department complaining dyspnea. Due to acute decompensated heart failure with ongoing cardiogenic shock, he was admitted to our intensive cardiology unit. Initial work up. The blood exams showed a normal renal and liver function, normal total and free calcium, 9.4 mg/dL and 1.16 mmol/L respectively, lactates were mildly increased. The chest x–ray showed pulmonary congestion. At the echocardiography we found severe biventricular dysfunction, moderate mitral regurgitation, severe pulmonary hypertension. Since the patient was unstable, adrenaline, high–dose sodium nitroprusside (SNP), and intra–aortic balloon pump were started. The right heart catheterization revealed combined pulmonary hypertension reversible with SNP and, therefore, the patient was inserted in the heart transplant list. Diagnosis and Management. One of the side effects of SNP is the thiocyanate toxicity. A high dose of SNP was necessary for this patient (2.2 mcg/kg/min). Thus, thiocyanate levels increased up to 10 mg/100 mL (NV<3). Importantly, the patient was asymptomatic despite these levels. However, the free calcium ion progressively decreased up to 0.94 mmol/L, despite normal total calcium and calcium supplementation iv and orally. Since arrhythmic burden markedly increased, we started lidocaine which was not effective. Follow–up. Since we suspected a possible causative role of thiocyanate, which might bond the double positive charged free calcium ion with its two negatively charged sulfur atoms, explaining the normal total calcium level and the low calcium ion, we carefully reduced SNP dose within days. This allowed us to reduce thiocyanate to 6 mg/100 mL, without compromising patient hemodynamics. Concomitantly, the free calcium ion tended to normalize, lowering the arrhythmic burden. Conclusions We describe for the first time a proarrhythmic side effect of prolonged SNP infusion, likely related to thiocyanate accumulation and free calcium ion binding, which, despite aggressive calcium supplementation, was normalized only after SNP down titration.

Sodium Nitroprusside Inhibits Detrusor Muscle Contraction through G-protein Mediated Inhibition of Intracellular Ca2+ Release

Background: Nitric oxide (NO) physiology is very complex in detrusor smooth muscle (DSM). While NO relaxes detrusor in some species, in contrary, it produces contraction in other. NO donor sodium nitroprusside (SNP) was found to inhibit CCh-induced contraction in goat DSM in earlier studies, but it is not known how SNP produces inhibitory action on goat DSM. Therefore, the aim of this in vitro study was to investigate the mechanism of inhibitory action of SNP pertaining to involvement of G- protein and other second messenger on goat DSM. Methods: Goat detrusor muscle strips collected from local abattoir were mounted in a thermostatically controlled (37o±0.5oC) organ bath (20 ml capacity) containing physiological solution. Following 1 hr of equilibration, carbachol (CCh) (10-5 M) induced sub-maximal contraction was elicited both in the absence and presence of SNP (10-5 M). Involvement of NO and guanylyl cyclase was assessed using nitric oxide synthase inhibitor L-NAME (10-5 M) and guanylyl cyclase inhibitor ODQ (10-5 M). Experiments were also carried out in the presence of G-protein activator aluminium fluoride (AlF) (10-5 M), protein kinase C (PKC) activator phorbol-12-myristate (PMA) (10-5 M), nifedipine, low Ca2+ PSS, theophylline and Zero Ca2+ PSS. Result: Inhibitory effect of SNP (10-5 M) on CCh-induced contraction on goat DSM was reversed by nitric oxide synthase inhibitor L-name (10-5 M) and guanylyl cyclase inhibitor ODQ (10-5 M). Prior incubation of the tissues with AlF and PMA also reversed the SNP mediated inhibition. On the other hand, nifedipine and low Ca2+ PSS; and theophylline and zero Ca2+ PSS potentiated the SNP-mediated inhibition. Thus, the present study shows that SNP elicited inhibitory effect on goat DSM is both NO-dependent and cGMP-dependent. In addition, the result shows that SNP inhibits G-protein coupled PKC leading to inhibition of both Ca2+ entry and intracellular Ca2+ release with a resultant decrease in intracellular Ca2+.

854 SODIUM NITROPRUSSIDE IN ACUTE HEART FAILURE: EFFECTS ON LV AFTERLOAD AND VENTRICULO-ARTERIAL COUPLING

Abstract Background Acute heart failure (AHF) with left ventricle (LV) dysfunction is characterized by a condition of afterload mismatch without preload reserve. LV ejection fraction (LVEF) and stroke volume (SV) become thus dependent on the afterload. Owing to its arteriolar vasodilator properties, sodium nitroprusside (SNP) may reduce LV afterload and result particularly beneficial in this setting, improving LV ejection and ventriculo-arterial coupling (VAC). Hypothesis We aimed to assess the effect of SNP on LV afterload (arterial elastance, Ea), LV contractility (end-systolic elastance, Ees) and VAC (Ea/Ees ratio) in AHF patients. Methods Patients with AHF receiving SNP were prospectively enrolled and underwent Ea and Ees estimation with a single-beat echocardiographic method, before and after SNP infusion. The method was described by Chen et al (J Am Coll Cardiol, 2001) and Kelly et al (Circulation, 1992). Echocardiography was analyzed by a physician blinded to the images timing. Results A total of 36 AHF patients [69% male, age 70 (68, 76) years] received SNP infusion and were enrolled. Patients were admitted for acute coronary syndrome (47%) and for worsening heart failure (53%). SNP median dose was low: 0.30 (0.21-0.57) mcg/kg/min. SNP led to a trend to SBP reduction [140 (131-150) vs 158 (140-168) mmHg; p=0.002]. Heart rate did not change: 84 (75, 92) vs 83 (72, 94) bpm; p=0.800. Afterload (Ea) was reduced following SNP infusion: 2.2 (1.9, 2.7) vs 2.8 (2.4, 3.4) mmHg/mL; p<0.001. LV contractility (Ees) was unchanged: 1.3 (0.8, 2.2) vs 1.5 (0.9, 3.4) mmHg/mL; p=0.13. End-diastolic volume did not change: 148 (110, 205) vs 146 (108, 213) mL; p=0.880. These effects led to an increased SV: 56 (47, 67) vs 50 (38, 56) mL; p<0.001; p<0.001 and, subsequently to an increased EF [40 (30, 50) vs 30 (20, 40)%; p<0.001]. The VAC did not significantly change after SNP infusion: 1.5 (0.9-2.8) vs 1.6 (0.9-2.7); p=0.64. Conclusion In this report on consecutive AHF, low-dose SNP did not significantly affect VAC but led to a significant reduction in LV afterload and to a significant increase in SV and LVEF.

Regulation of enzymatic and non-enzymatic antioxidants in rice seedlings against chromium stress through sodium hydrosulfide and sodium nitroprusside.

Hydrogen sulfide (H2S) and nitric oxide (NO) play a well-organized protective mechanism in coping with oxidative stress induced by toxic metals. However, the comparative effects of H2S and NO on enzymatic and non-enzymatic antioxidants in plants under Cr(III) stress have not been defined. In this study, we mathematically evaluate the importance of sodium hydrosulfide (NaHS) and sodium nitroprusside (SNP) on these two antioxidant systems in rice seedlings under Cr(III) stress. The results displayed that the optimal dose of NaHS and SNP was 100μM and 75μM, respectively, in rice tissues under Cr(III) stress, judging by the reactive oxygen species (ROS) levels in rice tissues. When rice seedlings wereexposed to Cr(III) atconcentrations of3.57, 7.24, 26.52mg Cr/l, Cr-inducedROS accumulationhad a significant (p < 0.05)effecton the lipid peroxidation of cell membrane in rice tissues, and decreasedthe response of SOD, CAT, Pro, GSH, and AsA in rice tissues. Application of exogenous NaHS and SNP effectively (p < 0.05) alleviated the toxic effects of Cr(III) in rice seedlings by activating different antioxidants. A novel physiological response model suggested that the regulatory effect of NaHS and SNP on non-enzymatic antioxidants was stronger than that of enzymatic antioxidants. Moreover, NaHS-mediated response intensity of both enzymatic and non-enzymatic antioxidants was greater than that of SNP, suggesting the importance of utilizing NaHS over SNP as antioxidant regulators during detoxification of Cr(III) in rice seedlings.

Individual and combinatorial effects of SNP and NaHS on morpho-physio-biochemical attributes and phytoextraction of chromium through Cr-stressed spinach (Spinacia oleracea L.).

Chromium (Cr) is a toxic heavy metal that contaminates soil and water resources after its discharge from different industries. A pot experiment was conducted to determine the effects of single and/or combined application of sodium nitroprusside (SNP) (250 μM) and sodium hydrogen sulfide (NaHS) (1 mM) on growth, photosynthetic pigments, gas exchange characteristics, oxidative stress biomarkers, antioxidant machinery (enzymatic and non-enzymatic antioxidants), ion uptake, organic acid exudation, and Cr uptake of spinach (Spinacia oleracea L.) exposed to severe Cr stress [Cr: 0 (no Cr), 150, and 300 μM]. Our results depicted that Cr addition to the soil significantly (P < 0.05) decreased plant growth and biomass, gas exchange attributes, and mineral uptake by S. oleracea when compared to the plants grown without the addition of Cr. However, Cr toxicity boosted the production of reactive oxygen species (ROS) by increasing the content of malondialdehyde (MDA), which is the indication of oxidative stress in S. oleracea, and was also manifested by hydrogen peroxide (H2O2) content and electrolyte leakage to the membrane-bound organelles. The results showed that the activities of various antioxidative enzymes, such as superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and the content of non-enzymatic antioxidants, such as phenolic, flavonoid, ascorbic acid, and anthocyanin, initially increased with an increase in the Cr concentration in the soil. The results also revealed that the levels of soluble sugar, reducing sugar, and non-reducing sugar were decreased in plants grown under elevating Cr levels, but the accumulation of the metal in the roots and shoots of S. oleracea, was found to be increased, and the values of bioaccumulation factor were <1 in all the Cr treatments. The negative impacts of Cr injury were reduced by the application of SNP and NaHS (individually or combined), which increased plant growth and biomass, improved photosynthetic apparatus, antioxidant enzymes, and mineral uptake, as well as diminished the exudation of organic acids and oxidative stress indicators in roots of S. oleracea by decreasing Cr toxicity. Here, we conclude that the application of SNP and NaHS under the exposure to Cr stress significantly improved plant growth and biomass, photosynthetic pigments, and gas exchange characteristics; regulated antioxidant defense system and essential nutrient uptake; and balanced organic acid exudation pattern in S. oleracea.

Efficacy of Exogenous Sodium Nitroprusside, Salicylic Acid and Moringa (Moringa oleifera) Leaf Extracts as Biostimulants on Growth and Physiological Attributes of Rubber (Hevea brasiliensis) under Sub-optimal Climatic Conditions

Stress phenomena that coincide, such as drought and heat, have been shown to affect the growth of rubber (Hevea brasiliensis) negatively under sub-optimal climatic conditions in nontraditional drier areas of Sri Lanka. Exogenous sodium nitroprusside (SNP), salicylic acid (SA), and moringa leaf extract (MLE) as bio-stimulants have been shown to improve the growth and physiology of crop plants under sub-optimal climatic conditions. Therefore, the present study aimed at exploring the effect of the above bio-stimulants on the growth and physiology of rubber under sub-optimal climatic conditions. Rubber plants of clone RRIC 121 cultivated in Hingurana, Ampara, Dry Zone (DZ) were spray treated with SNP at 100 and 200 µM, SA at 0.1 and 0.2 µM, and MLE at 5, 10% concentrations at monthly intervals for six months. Physiological parameters viz. chlorophyll content (cc), stomatal conductance (gs), and leaf water potential (Ψ) were recorded before and after three months from the commencement of treatments while growth measurements (girth and height) were recorded at three and ten months of treatments. Significantly higher girth values were recorded in plants treated with SNP, SA, and MLE at all concentrations compared to control and mock treatment after ten months from the commencement of treatments. Significantly higher chlorophyll values were recorded in plants treated with SNP at 100 µM (50.6±1.85), 200 µM (53.4±1.24), SA at 0.1 µM (49.5±1.49), MLE at 5% (50.1±1.98) and 10% (51.1±1.35) concentrations compared to control (41.9±1.15) and mock treatment (44.6±1.32) respectively after ten months from the commencement of treatments. Significantly higher leaf water potential values were recorded in plants treated with SNP, SA, and MLE at all concentrations compared to control and mock treatments after three months of the first treatment. Significantly lower stomatal conductance values were recorded in plants treated with SNP at 200 µM, SA at 0.1 and 0.2 µM, and MLE at 10% concentrations compared to control and mock treatments after three months from the first treatment. Improved growth and physiological attributes of rubber plants could be attributed to the beneficial effect of SNP, SA, and MLE as bio-stimulants. Therefore, exogenous application of the above bio-stimulants may be utilized for growth improvement in Hevea sp. under sub-optimal climatic conditions.&#x0D; Keywords: Bio-stimulants, Growth, Physiological parameters, Rubber, Sub-optimal climatic conditions

WITHDRAWN: Brucine restores sodium nitroprusside-induced chondrocyte dysfunction by suppressing the GSK-3β/β-catenin pathway

The dysfunction of chondrocytes is thought to play a role in the initiation and progression of osteoarthritis (OA). Brucine possesses wide pharmacological activities. But the protective mechanism of the brucine on chondrocytes remains unclear. This study is aimed to determine the therapeutic effects of brucine on the mouse chondrocyte OA model by sodium nitroprusside (SNP). The primary chondrocytes were obtained from the knee articular cartilage of a healthy suckling mouse donor. The cultured chondrocytes were divided into the control group, SNP group, brucine group, brucine-SNP group, brucine-SNP-GSK-3β antagonist group (brucine-SNP- group), and brucine-SNP-GSK-3β agonist group (brucine-SNP-GSK-3β+ group). After 24 h, the chondrocytes from different treated groups were collected to detect chondrocyte proliferation and ultrastructure, regulation factors, apoptosis, oxidative stress, and GSK-3β/β-catenin pathway. Compared to the SNP group, chondrocyte proliferation, and regulation factors were promoted, and chondrocyte apoptosis, oxidative stress, and the GSK-3β/β-catenin pathway were inhibited by brucine. It indicates that the adverse effect of SNP is reversed by the brucine on the chondrocyte. Compared to the brucine-SNP group, the effect of brucine on the chondrocyte proliferation, regulation factothe apoptosis, and oxidative stress were promoted by the GSK-3β antagonist. It indicates that the chondrocyte is protected agairucine through buying the GSK-3β/β-catenin pathway.

Cardioprotective actions of nitroxyl donor Angeli's salt are preserved in the diabetic heart and vasculature in the face of nitric oxide resistance

Background and PurposeThe risk of fatal cardiovascular events is increased in patients with type 2 diabetes mellitus (T2DM). A major contributor to poor prognosis is impaired nitric oxide (NO•) signalling at the level of tissue responsiveness, termed NO• resistance. This study aimed to determine if T2DM promotes NO• resistance in the heart and vasculature and whether tissue responsiveness to nitroxyl (HNO) is affected.Experimental ApproachAt 8 weeks of age, male Sprague–Dawley rats commenced a high‐fat diet. After 2 weeks, the rats received low‐dose streptozotocin (two intraperitoneal injections, 35 mg·kg−1, over two consecutive days) and continued on the same diet. Twelve weeks later, isolated hearts were Langendorff‐perfused to assess responses to the NO• donor diethylamine NONOate (DEA/NO) and the HNO donor Angeli's salt. Isolated mesenteric arteries were utilised to measure vascular responsiveness to the NO• donors sodium nitroprusside (SNP) and DEA/NO, and the HNO donor Angeli's salt.Key ResultsInotropic, lusitropic and coronary vasodilator responses to DEA/NO were impaired in T2DM hearts, whereas responses to Angeli's salt were preserved or enhanced. Vasorelaxation to Angeli's salt was augmented in T2DM mesenteric arteries, which were hyporesponsive to the relaxant effects of SNP and DEA/NO.Conclusion and ImplicationsThis is the first evidence that inotropic and lusitropic responses are preserved, and NO• resistance in the coronary and mesenteric vasculature is circumvented, by the HNO donor Angeli's salt in T2DM. These findings highlight the cardiovascular therapeutic potential of HNO donors, especially in emergencies such as acute ischaemia or heart failure.

Nitric oxide inhibits endothelial cell apoptosis by inhibiting cysteine‐dependent SOD1 monomerization

Endothelial cell apoptosis is an important pathophysiology in many cardiovascular diseases. The gasotransmitter nitric oxide (NO) is known to regulate cell survival and apoptosis. However, the mechanism underlying the effect of NO remains unclear. In this research, by targeting cytosolic copper/zinc superoxide dismutase (SOD1) monomerization, we aimed to explore how NO inhibited endothelial cell apoptosis. We showed that treatment with the NO synthase (NOS) inhibitor nomega‐nitro‐l‐arginine methyl ester hydrochloride (L‐NAME) significantly decreased the endogenous NO content of endothelial cells, facilitated the formation of SOD1 monomers, inhibited dismutase activity, and promoted reactive oxygen species (ROS) accumulation in human umbilical vein endothelial cells (HUVECs); by contrast, supplementation with the NO donor sodium nitroprusside (SNP) upregulated NO content, prevented the formation of SOD1 monomers, enhanced dismutase activity, and reduced ROS accumulation in L‐NAME‐treated HUVECs. Mechanistically, tris(2‐carboxyethyl) phosphine hydrochloride (TCEP), a specific reducer of cysteine thiol, increased SOD1 monomer formation, thus preventing the NO‐induced increase in dismutase activity and the decrease in ROS. Furthermore, SNP inhibited HUVEC apoptosis caused by the decrease in endogenous NO, whereas TCEP abolished this protective effect of SNP. In summary, our data reveal that NO protects endothelial cells against apoptosis by inhibiting cysteine‐dependent SOD1 monomerization to enhance SOD1 activity and inhibit oxidative stress.

Sodium nitroprusside protects HFD induced gut dysfunction via activating AMPK\u03b1/SIRT1 signaling

BackgroundActivation of Adenosine 5′-monophosphate-activated protein kinase/Sirtuin1 (AMPK/SIRT1) exerts an effect in alleviating obesity and gut damage. Sodium nitroprusside (SNP), a nitric oxide (NO) donor, has been reported to activate AMPK. This study was to investigate the effect of SNP on HFD induced gut dysfunction and the mechanism.MethodsSNP was applied on lipopolysaccharide (LPS) stimulated Caco-2 cell monolayers which mimicked intestinal epithelial barrier dysfunction and HFD-fed mice which were complicated by gut dysfunction. Then AMPKα/SIRT1 pathway and gut barrier indicators were investigated.ResultsSNP rescued the loss of tight junction proteins ZO-1 and occludin, the inhibition of AMPKα/SIRT1 in LPS stimulated Caco-2 cell monolayers, and the effects were not shown when AMPKa1 was knocked-down by siRNA. SNP also alleviated HFD induced obesity and gut dysfunction in mice, as indicated by the decreasing of intestinal permeability, the increasing expression of ZO-1 and occludin, the decreasing levels of pro-inflammatory cytokine IL-6, and the repairing of gut microbiota dysbiosis. These effects were complicated by the increased colonic NO content and the activated AMPKα/SIRT1 signaling.ConclusionsThe results may imply that SNP, as a NO donor, alleviates HFD induced gut dysfunction probably by activating the AMPKα/SIRT1 signaling pathway.