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Superoxide anion

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https://www.readbyqxmd.com/read/28930314/concerted-double-proton-transfer-electron-transfer-between-catechol-and-superoxide-radical-anion
#1
Jorge Quintero-Saumeth, David A Rincón, Markus Doerr, Martha C Daza
We have carried out a computational study on the reactivity of catechol (1,2-dihydroxybenzene) towards superoxide radical anion (O2˙(-)) in water, N,N-dimethylformamide (DMF), pentyl ethanoate (PEA) and vacuum using density functional theory and the coupled cluster method. Five reaction mechanisms were studied: (i) sequential proton transfer followed by hydrogen atom transfer (PT-HT), (ii) sequential hydrogen atom transfer followed by proton transfer (HT-PT), (iii) single electron transfer (SET), (iv) radical adduct formation (RAF) and (v) concerted double proton-transfer electron-transfer (denoted as global reaction, GR)...
September 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28928969/morphine-pre-and-post-conditioning-exacerbates-apoptosis-in-rat-hippocampus-cells-in-a-model-of-homocysteine-induced-oxidative-stress
#2
Ahmad Karkhah, Ramin Ataee, Amin Ataie
Recent investigations indicated that morphine has protective effects in different ischemia/reperfusion models and may protect against neuronal cell death, while other evidence showed that morphine induces apoptosis in neurons. Therefore, the current study was conducted to investigate pre- and post-conditioning effects of morphine on hippocampal cell apoptosis in a rat model of homocysteine (Hcy)-induced oxidative stress. In the present study, 0.5 µmol/µl Hcy was injected into bilateral intrahipocampal in the rat brain and morphine at a therapeutic dose of 10 mg/kg was injected intraperitoneally 5 days before and after Hcy injection in rats...
October 2017: Biomedical Reports
https://www.readbyqxmd.com/read/28920713/estradiol-decreases-blood-pressure-in-association-with-redox-regulation-in-preeclampsia
#3
Goran M Babic, Snezana D Markovic, Mirjana Varjacic, Natasa Z Djordjevic, Tamara Nikolic, Isidora Stojic, Vladimir Jakovljevic
In this study, we tested a hypothesis that a short-term estradiol therapy may reduce blood pressure in preeclampsia by modulating plasma oxidative stress. The intramuscular injections of 10 mg 17-beta-estradiol were prescribed to preeclamptic pregnant women during the 3-day therapy before a labor induction. The analyses of mean arterial pressure (MAP), serum estradiol concentrations, plasma superoxide anion (O2.), hydrogen peroxide (H2O2), nitrites (NO2(-)), and peroxynitrite (ONOO(-)) were conducted before and during the therapy...
September 18, 2017: Clinical and Experimental Hypertension: CHE
https://www.readbyqxmd.com/read/28917144/silicon-improves-seed-germination-and-alleviates-drought-stress-in-lentil-crops-by-regulating-osmolytes-hydrolytic-enzymes-and-antioxidant-defense-system
#4
Sajitha Biju, Sigfredo Fuentes, Dorin Gupta
Silicon (Si) has been widely reported to have beneficial effect on mitigating drought stress in plants. However, the effect of Si on seed germination under drought conditions is still poorly understood. This research was carried out to ascertain the role of Si to abate polyethylene glycol-6000 mediated drought stress on seed germination and seedling growth of lentil. Results showed that drought stress significantly decreased the seed germination traits and increased the concentration of osmolytes (proline, glycine betaine and soluble sugars), reactive oxygen species (hydrogen peroxide and superoxide anion) and lipid peroxides in lentil seedlings...
September 5, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28916474/nox4-regulates-the-enos-uncoupling-process-in-aging-endothelial-cells
#5
Hwa-Young Lee, Hyung-Ryong Kim, Han-Jung Chae
ROS and its associated signaling contribute to vascular aging-associated endothelial disturbance. Since the non-effective endothelial nitric oxide synthase (eNOS) coupling status is related to vascular aging-related phenotypes, eNOS coupled/uncoupled system signaling was studied in human umbilical vein endothelial cells (HUVEC). Nitric oxide (NO) and eNOS Ser1177 were significantly decreased, whereas O2(-) (superoxide anion radical) increased with passage number. In aging cells, NADPH oxidase 4 (Nox4), one of the main superoxide generating enzymes, and its associated protein disulfide isomerase (PDI) chaperone were highly activated, and the resultant ER redox imbalance leads to disturbance of protein folding capability, namely endoplasmic reticulum (ER) stress, ultimately inducing dissociation between HSP90 and IRE-1α or PERK, decreasing HSP90 stability and dissociating the binding of eNOS from the HSP90 and leading to eNOS uncoupling...
September 12, 2017: Free Radical Biology & Medicine
https://www.readbyqxmd.com/read/28912106/vascular-activation-of-k-channels-and-na-k-atpase-activity-of-estrogen-deficient-female-rats
#6
Rogério Faustino Ribeiro, Jonaina Fiorim, Vinicius Bermond Marques, Karoline de Sousa Ronconi, Tatiani Botelho, Marcella D Grando, Lusiane M Bendhack, Dalton Valentim Vassallo, Ivanita Stefanon
The goal of the present study was to evaluate vascular potassium channels and Na(+)-K(+)-ATPase activity in estrogen deficient female rats. Female rats that underwent ovariectomy were assigned to receive daily treatment with placebo (OVX) or estrogen replacement (OVX+E2, 1mg/kg, once a week, i.m.). Aortic rings were used to examine the involvement of K(+) channels and Na(+)-K(+)-ATPase in vascular reactivity. Acetylcholine (ACh)-induced relaxation was analyzed in the presence of L-NAME (100μM) and K(+) channels blockers: tetraethylammonium (TEA, 5mM), 4-aminopyridine (4-AP, 5mM), iberiotoxin (IbTX, 30nM), apamin (0...
September 11, 2017: Vascular Pharmacology
https://www.readbyqxmd.com/read/28911634/extraction-and-quantification-of-polyphenols-from-kinnow-citrus-reticulate-l-peel-using-ultrasound-and-maceration-techniques
#7
Muhammad N Safdar, Tusneem Kausar, Saqib Jabbar, Amer Mumtaz, Karam Ahad, Ambreen A Saddozai
An investigation was carried out to extract polyphenols from the peel of kinnow (Citrus reticulate L.) by maceration and ultrasound-assisted extraction (UAE) techniques. The antioxidant potential of these polyphenols was evaluated using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide radical scavenging assays; and their antimicrobial activity was assessed against bacterial strains Staphyloccoccus aureus, Bacillus cereus, and Salmonella typhimurium. The highest extraction yield was obtained through the solvent ethanol at 80% concentration level, whereas UAE was a more efficient technique and yielded comparatively higher polyphenol contents than maceration...
July 2017: Journal of Food and Drug Analysis
https://www.readbyqxmd.com/read/28901421/uric-acid-induces-the-expression-of-tnf%C3%A2-%C3%AE-via-the-ros%C3%A2-mapk%C3%A2-nf%C3%A2-%C3%AE%C2%BAb-signaling-pathway-in-rat-vascular-smooth-muscle-cells
#8
Lirong Tang, Yu'e Xu, Ying Wei, Xu He
Hyperuricemia and artery atherosclerosis are closely associated and, as a classic inflammatory biomarker, tumor necrosis factor‑α (TNF‑α) has a direct role in atherogenesis. In the present study, it was demonstrated that uric acid was capable of inducing the generation of TNF‑α in vascular smooth muscle cells (VSMCs). The expression levels of proteins were detected using enzyme‑linked immunosorbent assays and western blot analysis. The expression levels of mRNAs were determined using reverse transcription‑quantitative polymerase chain reaction analysis, and superoxide anion levels were detected using a fluorescence microscope...
August 31, 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28901374/ferulic-acid-exerts-neuroprotective-effects-against-cerebral-ischemia-reperfusion-induced-injury-via-antioxidant-and-anti-apoptotic-mechanisms-in%C3%A2-vitro-and-in%C3%A2-vivo
#9
Zhongkun Ren, Rongping Zhang, Yuanyuan Li, Yu Li, Zhiyong Yang, Hui Yang
Ferulic acid (FA) is a derivative of cinnamic acid. It is used in the treatment of heart head blood-vessel disease and exerts protective effects against hypoxia/ischemia-induced cell injury in the brain. This study investigated the potential neuroprotective effects of FA against ischemia/reperfusion (I/R)-induced brain injury in vivo and in vitro through hematoxylin and eosin (H&E) and Nissl staining assays, flow cytometry, Hoechst 33258 staining, quantitative PCR, western blot analysis and fluorescence microscopic analysis...
September 7, 2017: International Journal of Molecular Medicine
https://www.readbyqxmd.com/read/28900851/tributyltin-chloride-disrupts-aortic-vascular-reactivity-and-increases-reactive-oxygen-species-production-in-female-rats
#10
Carolina Falcão Ximenes, Samya Mere Lima Rodrigues, Priscila Lang Podratz, Eduardo Merlo, Julia Fernandez Puñal de Araújo, Lívia Carla Melo Rodrigues, Juliana Barbosa Coitinho, Dalton Valentim Vassallo, Jones Bernardes Graceli, Ivanita Stefanon
Organotin compounds, such as tributyltin (TBT), are environment contaminants that induce bioaccumulation and have potential toxic effects on marine species and mammals. TBT have been banned by the International Maritime Organization in 2003. However, the assessment of butyltin and metal contents in marine sediments has demonstrated high residual levels of TBT in some cases exceeding 7000 ng Sn g(-1). The acceptable daily intake (ADI) level for TBT established by the World Health Organization is 0.5 μg/kg bw/day is based on genotoxicity, reproduction, teratogenicity, immunotoxicity, and mainly neurotoxicity...
September 13, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28898862/degradation-and-intermediates-of-diclofenac-as-instructive-example-for-decomposition-of-recalcitrant-pharmaceuticals-by-hydroxyl-radicals-generated-with-pulsed-corona-plasma-in-water
#11
Robert Banaschik, Helena Jablonowski, Patrick J Bednarski, Juergen F Kolb
Seven recalcitrant pharmaceutical residues (diclofenac, 17α-ethinylestradiol, carbamazepine, ibuprofen, trimethoprim, diazepam, diatrizoate) were decomposed by pulsed corona plasma generated directly in water. The detailed degradation pathway was investigated for diclofenac and 21 intermediates could be identified in the degradation cascade. Hydroxyl radicals have been found primarily responsible for decomposition steps. By spin trap enhanced electron paramagnetic resonance spectroscopy (EPR), OH-adducts and superoxide anion radical adducts were detected and could be distinguished applying BMPO as a spin trap...
August 25, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28889360/enhanced-effect-of-hah-on-citric-acid-chelated-fe-ii-catalyzed-percarbonate-for-trichloroethene-degradation
#12
Xiaori Fu, Mark L Brusseau, Xueke Zang, Shuguang Lu, Xiang Zhang, Usman Farooq, Zhaofu Qiu, Qian Sui
This work demonstrates the impact of hydroxylamine hydrochloride (HAH) addition on enhancing the degradation of trichloroethene (TCE) by the citric acid (CA)-chelated Fe(II)-catalyzed percarbonate (SPC) system. The results of a series of batch-reactor experiments show that TCE removal with HAH addition was increased from approximately 57 to 79% for a CA concentration of 0.1 mM and from 89 to 99.6% for a 0.5 mM concentration. Free-radical probe tests elucidated the existence of hydroxyl radical (HO(•)) and superoxide anion radical (O2(•-)) in both CA/Fe(II)/SPC and HAH/CA/Fe(II)/SPC systems...
September 9, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28887419/oxidative-stressors-modify-the-response-of-streptococcus-mutans-to-its-competence-signal-peptides
#13
Matthew De Furio, Sang Joon Ahn, Robert A Burne, Stephen J Hagen
The dental caries pathogen Streptococcus mutans is continually exposed to several types of stress in the oral biofilm environment. Oxidative stress generated by reactive oxygen species has a major impact on the establishment, persistence and virulence of S. mutans. Here, we combined fluorescent reporter-promoter fusions with single-cell imaging to study the effects of reactive oxygen species on activation of genetic competence in S. mutans Exposure to paraquat, which generates superoxide anion, produced a qualitatively different effect on activation of expression of the gene for the master competence regulator, ComX, than did treatment with hydrogen peroxide (H2O2), which can yield hydroxyl radical...
September 8, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28881573/histopathological-findings-of-renal-tissue-induced-by-oxidative-stress-due-to-different-concentrations-of-fluoride
#14
Qin Luo, Hengmin Cui, Huidan Deng, Ping Kuang, Huan Liu, Yujiao Lu, Jing Fang, Zhicai Zuo, Junliang Deng, Yinglun Li, Xun Wang, Ling Zhao
It has been reported that excessive intake of fluoride can induce renal lesions. However, its pathogenesis is still less understood. Therefore, this study was conducted to investigate oxidative damage and the relationships between the oxidative damage and renal lesions in fluoride-treated mice by using the methods of histopathology, biochemistry, flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR). A total of 240 ICR mice were randomly divided into four equal groups (sodium fluoride was given orally at the dose of 0, 12, 24 and 48 mg/kg body weight for 42 days, respectively)...
August 1, 2017: Oncotarget
https://www.readbyqxmd.com/read/28881317/modulation-of-antioxidative-defense-expression-and-osmolyte-content-by-co-application-of-24-epibrassinolide-and-salicylic-acid-in-pb-exposed-indian-mustard-plants
#15
Sukhmeen Kaur Kohli, Neha Handa, Shagun Bali, Saroj Arora, Anket Sharma, Ravdeep Kaur, Renu Bhardwaj
The study focuses on potential of combined pre-soaking treatment of 24-Epibrassinolide (EBL) and Salicylic acid (SA) in alleviating Pb phytotoxicity in Brassica juncea L. plants. The seeds after treatment with combination of both the hormones were sown in mixture of soil, sand and manure (3:1:1) and were exposed to Pb concentrations (0.25mM, 0.50mM and 0.75mM). After 30 days of growth, the plants were harvested and processed, for quantification of various metabolites. It was found that pre-sowing of seeds in combination of EBL and SA, mitigated the adverse effects of metal stress by modulating antioxidative defense response and enhanced osmolyte contents...
September 4, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28881201/double-z-scheme-system-of-silver-bromide-bismuth-tungstate-tungsten-trioxide-ternary-heterojunction-with-enhanced-visible-light-photocatalytic-activity
#16
Mengmeng Zhang, Youyi Zhu, Wenjun Li, Fangzhi Wang, Hongda Li, Xintong Liu, Weiwei Zhang, Chaojun Ren
The ternary heterojunction of silver bromide@bismuth tungstate/tungsten trioxide (AgBr@Bi2WO6/WO3) was designed and synthesised by hydrothermal and deposition-precipitation approaches. The composites were characterised by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy (XPS). The photoabsorption range and bandgaps of the photocatalysts were analysed by ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). Compared with Bi2WO6/WO3 or AgBr alone, the AgBr@Bi2WO6/WO3 composites displayed higher visible-light photocatalytic performance for degrading rhodamine B (RhB)...
August 31, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28873463/effects-of-antimony-on-redox-activities-and-antioxidant-defence-systems-in-sunflower-helianthus-annuus-l-plants
#17
Alfonso Ortega, Inmaculada Garrido, Ilda Casimiro, Francisco Espinosa
The alterations induced by the toxicity of antimony (Sb) in the roots and leaves of sunflower plants were determined. The plants were grown hydroponically with different concentrations of Sb, a heavy metal which reduces biomass production and growth. There was preferential accumulation of Sb in the tissues of the roots, with the concentrations in the leaves being much lower. The accumulation of other mineral elements was also altered, especially that of Fe and Zn. Chlorophyll content declined, as also did the photosynthetic efficiency, but the carotenoid content remained unaltered...
2017: PloS One
https://www.readbyqxmd.com/read/28873228/photodegradation-of-eumelanin-and-pheomelanin-and-its-pathophysiological-implications
#18
Shosuke Ito, Kazumasa Wakamatsu, Tadeusz Sarna
Eumelanin is photoprotective for pigmented tissues while pheomelanin is phototoxic. In this review, we summarize current understanding of how eumelanin and pheomelanin structures are modified by ultraviolet A (UVA) and also by visible light and how reactive oxygen species participate in those processes. Alkaline hydrogen peroxide oxidation was employed to characterize eumelanin and benzothiazole-type pheomelanin, giving pyrrole-2,3,5-tricarboxylic acid (PTCA) and thiazole-2,4,5-tricarboxylic acid (TTCA), respectively...
September 5, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28870504/the-oxidized-phospholipid-povpc-impairs-endothelial-function-and-vasodilation-via-uncoupling-endothelial-nitric-oxide-synthase
#19
Feng-Xia Yan, Hua-Ming Li, Shang-Xuan Li, Shi-Hui He, Wei-Ping Dai, Yan Li, Tian-Tian Wang, Mao-Mao Shi, Hao-Xiang Yuan, Zhe Xu, Jia-Guo Zhou, Da-Sheng Ning, Zhi-Wei Mo, Zhi-Jun Ou, Jing-Song Ou
Endothelial dysfunction is an early stage of atherosclerosis. We recently have shown that 25-hydroxycholesterol found in atherosclerotic lesions could impair endothelial function and vasodilation by uncoupling and inhibiting endothelial nitric oxide synthase (eNOS). 1-Palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), the oxidation product of oxidized low-density lipoprotein, is another proinflammatory lipid and has also been found in atherosclerotic lesions. However, whether POVPC promotes atherosclerosis like 25-hydroxycholesterol remains unclear...
September 1, 2017: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/28869525/persimmon-fruit-powder-may-substitute-indolbi-a-synthetic-growth-regulator-in-soybean-sprout-cultivation
#20
Il-Doo Kim, Sanjeev Kumar Dhungana, Yong-Sung Park, Dong Joon Kim, Dong-Hyun Shin
Soybean sprouts are a major food item in Korea. Various studies have been carried out to enhance their yield and nutritional values. The objective of the present study was to examine the influence of persimmon fruit powder and Indolbi, a synthetic plant growth regulator, on the yield and nutritional value of soybean sprouts. Seeds were soaked in tap water containing 0.5%, 1.0%, 2.5% and 5.0% (w/v) persimmon fruit powder and the samples were named as PT-1, PT-2, PT-3, and PT-4, respectively. The yield increment was almost doubled in PT-3 and PT-4 than in the Indolbi treated sprouts on basis of the control...
September 3, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
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