Involvement of nitric oxide in ultraviolet B-induced activation of phenylalanine ammoniumlyase and stimulation of flavonoid biosynthesis in Ginkgo biloba leaves

2009 ◽  
Vol 57 (1) ◽  
pp. 56 ◽  
Author(s):  
Gangping Hao ◽  
Xihua Du ◽  
Renjiu Shi ◽  
Jianmei Wang ◽  
Lei Feng
Keyword(s):  
Nitric Oxide ◽  
Secondary Metabolite ◽  
Ginkgo Biloba ◽  
Plant Defence ◽  
Ultraviolet B ◽  
No Production ◽  
Signal Molecule ◽  
Pal Activity ◽  
Subsequent Activation ◽  
Flavonoid Accumulation

Previous studies have shown that ultraviolet B (UV-B) irradiation can stimulate biosynthesis of secondary metabolites. Several other studies have demonstrated that nitric oxide (NO) is an important signal molecule that plays a key role in plant defence responses to UV-B irradiation. However, the signalling mechanism of NO involvement in UV-B-induced secondary-metabolite synthesis is unclear. The purpose of the present study is to investigate the role of NO in the accumulation UV-B-induced secondary metabolite in the leaves of Ginkgo biloba. Our results showed that UV-B irradiation induced multiple biological responses in the leaves of G. biloba, including increases in both NO production and nitric oxide synthase (NOS) activity, and subsequent activation of phenylalanine ammoniumlyase (PAL) and synthesis of flavonoids. Application of NO via the donor sodium nitroprusside (SNP) enhanced UV-B-induced PAL activity and increased accumulation of flavonoids in G. biloba leaves. Both the NOS inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) and the NO scavenger 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (c-PTIO) reduced the production of NO. Moreover, UV-B-induced increase in PAL activity and flavonoid accumulation were suppressed by L-NAME and c-PTIO. These findings suggest a causal relationship between NO release and both PAL activity and flavonoid accumulation under UV-B irradiation. In addition, the results also indicate that NO, produced via NOS-like activity in ginkgo leaves subjected to UV-B irradiation, might act as an essential signal molecule for triggering the activation of PAL and synthesis of flavonoids.

scholarly journals The light and dark sides of nitric oxide: multifaceted roles of nitric oxide in plant responses to light

2020 ◽  
Author(s):  
Patrícia Juliana Lopes-Oliveira ◽  
Halley Caixeta Oliveira ◽  
Zsuzsanna Kolbert ◽  
Luciano Freschi
Keyword(s):  
Nitric Oxide ◽  
Stress Responses ◽  
Light Stress ◽  
Control Plant ◽  
Ultraviolet B ◽  
Signaling Cascades ◽  
Carbon Gain ◽  
Plant Responses ◽  
No Production ◽  
Action Mechanisms

Abstract Light drives photosynthesis and informs plants about their surroundings. Regarded as a multifunctional signaling molecule in plants, nitric oxide (NO) has been repeatedly demonstrated to interact with light signaling cascades to control plant growth, development and metabolism. During early plant development, light-triggered NO accumulation counteracts negative regulators of photomorphogenesis and modulates the abundance of, and sensitivity to, plant hormones to promote seed germination and de-etiolation. In photosynthetically active tissues, NO is generated at distinct rates under light or dark conditions and acts at multiple target sites within chloroplasts to regulate photosynthetic reactions. Moreover, changes in NO concentrations in response to light stress promote plant defenses against oxidative stress under high light or ultraviolet-B radiation. Here we review the literature on the interaction of NO with the complicated light and hormonal signaling cascades controlling plant photomorphogenesis and light stress responses, focusing on the recently identified molecular partners and action mechanisms of NO in these events. We also discuss the versatile role of NO in regulating both photosynthesis and light-dependent stomatal movements, two key determinants of plant carbon gain. The regulation of nitrate reductase (NR) by light is highlighted as vital to adjust NO production in plants living under natural light conditions.

Nitric oxide synthase-like dependent NO production enhances heme oxygenase up-regulation in ultraviolet-B-irradiated soybean plants

2010 ◽  
Vol 71 (14-15) ◽  
pp. 1700-1707 ◽  
Author(s):  
Diego M. Santa-Cruz ◽  
Natalia A. Pacienza ◽  
Ariel H. Polizio ◽  
Karina B. Balestrasse ◽  
Maria L. Tomaro ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Heme Oxygenase ◽  
Ultraviolet B ◽  
No Production ◽  
Soybean Plants ◽  
Oxide Synthase

Nitric oxide regulation of mitochondrial oxygen consumption I: cellular physiology

2006 ◽  
Vol 291 (6) ◽  
pp. C1225-C1231 ◽  
Author(s):  
Cecilia Giulivi ◽  
Kazunobu Kato ◽  
Christopher Eric Cooper
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Oxygen Consumption ◽  
Subcellular Localization ◽  
Calcium Signaling ◽  
Intracellular Calcium ◽  
Reactive Oxygen ◽  
No Production ◽  
Oxygen Species ◽  
Signal Molecule

Mitochondrial biochemistry is complex, expanding from oxygen consumption, oxidative phosphorylation, lipid catabolism, heme biosynthesis, to apoptosis, calcium homeostasis, and production of reactive oxygen species, including nitric oxide (NO). The latter molecule is produced by a mitochondrial NO synthase (mtNOS). The rates of consumption and production determine the steady-state concentration of NO at subcellular levels, leading to regulation of mitochondrial events. Temporospatial processes tightly regulate production of NO in mitochondria to maximize target effects and minimize deleterious reactions. Temporal regulatory mechanisms of mtNOS include activation by calcium signaling and transcriptional/translational regulations. Calcium-activated mtNOS inhibits mitochondrial respiration, resulting in a decrease of the oxygen consumption. This negative regulation antagonizes the effects of calcium on calcium-dependent dehydrogenases in the citric acid cycle, preventing the formation of anoxic foci. Temporal regulation of NO production by intracellular calcium signaling is a complex process, considering the heterogeneous intracellular calcium response and distribution. NO production in mitochondria is spatially regulated by mechanisms that determine subcellular localization of mtNOS, likely acylation and protein-protein interactions, in addition to transcriptional regulation as neuronal NOS. Because NO rapidly decays in mitochondria, subcellular localization of mtNOS is crucial for NO to function as a signal molecule. These temporospatial processes are biologically important to allow NO to act as an effective signal molecule to regulate mitochondrial events such as oxygen consumption and reactive oxygen species production.

The Signaling Pathways in Nitric Oxide Production by Neutrophils Exposed to N-nitrosodimethylamine

2018 ◽  
Vol 16 (2) ◽  
pp. 194-199
Author(s):  
Wioletta Ratajczak-Wrona ◽  
Ewa Jablonska
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Polymorphonuclear Neutrophils ◽  
Microbial Pathogens ◽  
Human Neutrophils ◽  
No Production ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Background: Polymorphonuclear neutrophils (PMNs) play a crucial role in the innate immune system’s response to microbial pathogens through the release of reactive nitrogen species, including Nitric Oxide (NO). </P><P> Methods: In neutrophils, NO is produced by the inducible Nitric Oxide Synthase (iNOS), which is regulated by various signaling pathways and transcription factors. N-nitrosodimethylamine (NDMA), a potential human carcinogen, affects immune cells. NDMA plays a major part in the growing incidence of cancers. Thanks to the increasing knowledge on the toxicological role of NDMA, the environmental factors that condition the exposure to this compound, especially its precursors- nitrates arouse wide concern. Results: In this article, we present a detailed summary of the molecular mechanisms of NDMA’s effect on the iNOS-dependent NO production in human neutrophils. Conclusion: This research contributes to a more complete understanding of the mechanisms that explain the changes that occur during nonspecific cellular responses to NDMA toxicity.

scholarly journals Comparing the protective effects of resveratrol, curcumin and sulforaphane against LPS/IFN-γ-mediated inflammation in doxorubicin-treated macrophages

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haidy A. Saleh ◽  
Eman Ramdan ◽  
Mohey M. Elmazar ◽  
Hassan M. E. Azzazy ◽  
Anwar Abdelnaser
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Response ◽  
Raw 264.7 Cells ◽  
Inos Mrna ◽  
No Production ◽  
Raw 264.7 ◽  
Mrna Levels ◽  
Protective Effects ◽  
Tnf Α ◽  
Ifn Γ

AbstractDoxorubicin (DOX) chemotherapy is associated with the release of inflammatory cytokines from macrophages. This has been suggested to be, in part, due to DOX-mediated leakage of endotoxins from gut microflora, which activate Toll-like receptor 4 (TLR4) signaling in macrophages, causing severe inflammation. However, the direct function of DOX on macrophages is still unknown. In the present study, we tested the hypothesis that DOX alone is incapable of stimulating inflammatory response in macrophages. Then, we compared the anti-inflammatory effects of curcumin (CUR), resveratrol (RES) and sulforaphane (SFN) against lipopolysaccharide/interferon-gamma (LPS/IFN-γ)-mediated inflammation in the absence or presence of DOX. For this purpose, RAW 264.7 cells were stimulated with LPS/IFN-γ (10 ng/mL/10 U/mL) in the absence or presence of DOX (0.1 µM). Our results showed that DOX alone is incapable of stimulating an inflammatory response in RAW 264.7 macrophages. Furthermore, after 24 h of incubation with LPS/IFN-γ, a significant increase in tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS) mRNA levels was observed. Similarly, nitric oxide (NO) production and TNF-α and IL-6 protein levels were significantly upregulated. Moreover, in LPS/IFN-γ-treated macrophages, the microRNAs (miRNAs) miR-146a, miR-155, and miR-21 were significantly overexpressed. Interestingly, upon testing CUR, RES, and SFN against LPS/IFN-γ-mediated inflammation, only SFN was able to significantly reverse the LPS/IFN-γ-mediated induction of iNOS, TNF-α and IL-6 and attenuate miR-146a and miR-155 levels. In conclusion, SFN, at the transcriptional and posttranscriptional levels, exhibits potent immunomodulatory action against LPS/IFN-γ-stimulated macrophages, which may indicate SFN as a potential treatment for DOX-associated inflammation.

scholarly journals Two New Phomaligols from the Marine-Derived Fungus Aspergillus flocculosus and Their Anti-Neuroinflammatory Activity in BV-2 Microglial Cells

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 65
Author(s):  
Byeoung-Kyu Choi ◽  
Duk-Yeon Cho ◽  
Dong-Kug Choi ◽  
Phan Thi Hoai Trinh ◽  
Hee Jae Shin
Keyword(s):  
Nitric Oxide ◽  
Mass Spectrometry ◽  
Optical Rotation ◽  
Chemical Oxidation ◽  
Culture Broth ◽  
Membered Ring ◽  
Microglial Cells ◽  
No Production ◽  
Nmr Data ◽  
Ic50 Value

Two new phomaligols, deketo-phomaligol A (1) and phomaligol E (2), together with six known compounds (3–8) were isolated from the culture broth of the marine-derived fungus Aspergillus flocculosus. Compound 1 was first isolated as a phomaligol derivative possessing a five-membered ring. The structures and absolute configurations of the new phomaligols were determined by detailed analyses of mass spectrometry (MS), nuclear magnetic resonance (NMR) data, optical rotation values and electronic circular dichroism (ECD). In addition, the absolute configurations of the known compounds 3 and 4 were confirmed by chemical oxidation and comparison of optical rotation values. Isolated compounds at a concentration of 100 μM were screened for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Among the compounds, 4 showed moderate anti-neuroinflammatory effects with an IC50 value of 56.6 μM by suppressing the production of pro-inflammatory mediators in activated microglial cells without cytotoxicity.

Effects of L-citrulline supplementation on nitric oxide and antioxidant markers after high-intensity interval exercise in young men: a randomized controlled trial

2021 ◽  
pp. 1-23
Author(s):  
Kosar Valaei ◽  
Javad Mehrabani ◽  
Alexei Wong
Keyword(s):  
Nitric Oxide ◽  
High Intensity ◽  
Controlled Trial ◽  
Young Men ◽  
No Production ◽  
Double Blind ◽  
Interval Exercise ◽  
Damage Indices ◽  
High Intensity Interval ◽  
Antioxidant Markers

Abstract L-citrulline (L-Cit) is a nonessential amino acid that stimulates nitric oxide (NO) production and improves exercise performance by reducing muscle damage indices; however, the direct benefits of L-Cit on antioxidant markers are unclear. The aim of this study was to examine antioxidant responses to high-intensity interval exercise following acute L-Cit supplementation. Nine young men (21 ± 1 years) participated in a double-blind crossover study in which they received 12 g of L-Cit and placebo (PL) an hour prior to high-intensity interval exercise on two occasions, separated by a seven-day washout period. Blood samples were obtained before (PRE), immediately after (IP), 10 (10P), and 30 min after exercise (30P) from the cubital vein using standard procedures. Serum concentrations of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and NO metabolites (NOx) were measured. The exercise protocol significantly elevated SOD (p = 0.01) and GPx (p = 0.048) from PRE to 10P in the L-Cit group with greater changes than the PL group. CAT concentrations increased IP (p = 0.014) and remained elevated at 10P (p = 0.03) and 30P (p = 0.015) in both the L-Cit and PL conditions. NOx concentrations increased IP (p = 0.05) in the L-Cit group with greater changes than PL group in PRE to IP, PRE to 10P, and PRE to 30P (p < 0.05). Our data indicate that L-Cit supplementation (single 12 g dose pre-exercise) induces improvements in antioxidant markers following a session of high-intensity interval exercise in young men.

Cytokine and inflammatory mediators are associated with cytotoxic, anti-inflammatory and apoptotic activity of honeybee venom

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed A. Salama ◽  
Mohamed A. Younis ◽  
Roba M. Talaat
Keyword(s):  
Nitric Oxide ◽  
Cell Lines ◽  
Cancer Cell ◽  
Hela Cells ◽  
No Production ◽  
Hep G2 ◽  
Normal Cells ◽  
Tnf Α ◽  
Ifn Γ ◽  
Mcf 7

AbstractObjectiveThe present study aimed to evaluate cytotoxic, apoptotic, and anti-inflammatory properties of bee venom (BV) as well as changes in cytokine secretion levels and nitric oxide (NO) production using three different cancer cell lines [liver (Hep-G2), breast (MCF-7), and cervical (HPV-18 infected HeLa cells)] and two normal cells (splenocytes and macrophages (MQ).MethodsCytotoxic activity of BV against tumor cell lines and normal splenocytes/MQ was tested by MTT assay. By ELISA (ELISA); Tumor necrosis factor (TNF-α), Interleukine (IL-10) and interferon (IFN-γ) were measured. Caspase three expressions was evaluated using reverse transcription-polymerase chain reaction (RT-PCR). Nitric oxide (NO) was estimated using a colorimetric assay.ResultsBV has a significant cytotoxic effect on all cell lines in a dose- and time-dependent manner; none of them was toxic for normal cells. Treating Hep-G2 cells with BV showed a reduction in IL-10, elevation in TNF-α with no change in IFN-γ level. MCF-7 cells have low IL-10 and TNF-α and high IFN-γ production level. Elevation of IL-10 and IFN-γ coincides with a reduction in TNF-α level was demonstrated in HeLa cells. The expression of Caspase three was dramatically increased with elevation in BV concentration in all tested cancer cell lines. A gradual decrease in NO production by MQ with increasing BV dose was observed.ConclusionTaken together, our results stressed on the importance of BV as a potent anti-tumor agent against various types of cancers (Liver, Breast, and Cervix). Further steps towards the use of BV for pharmacological purposes must be done.

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