scholarly journals [11C]Ascorbic and [11C]dehydroascorbic acid, an endogenous redox pair for sensing reactive oxygen species using positron emission tomography

2016 ◽  
Vol 52 (27) ◽  
pp. 4888-4890 ◽  
Author(s):  
V. N. Carroll ◽  
C. Truillet ◽  
B. Shen ◽  
R. R. Flavell ◽  
X. Shao ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Positron Emission Tomography ◽  
Ascorbic Acid ◽  
Reactive Oxygen ◽  
Dehydroascorbic Acid ◽  
Emission Tomography ◽  
Oxygen Species ◽  
Redox Pair ◽  
Positron Emission

We report the radiosynthesis of an endogenous redox pair, [11C]ascorbic acid and [11C]dehydroascorbic acid and their application to ROS sensing.

18F-Labeled dihydromethidine: positron emission tomography radiotracer for imaging of reactive oxygen species in intact brain

2020 ◽  
Vol 18 (13) ◽  
pp. 2387-2391 ◽  
Author(s):  
Hiromichi Egami ◽  
Satoshi Nakagawa ◽  
Yuki Katsura ◽  
Masakatsu Kanazawa ◽  
Shingo Nishiyama ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Positron Emission Tomography ◽  
Benzene Ring ◽  
Reactive Oxygen ◽  
Emission Tomography ◽  
Oxygen Species ◽  
Non Invasive ◽  
Positron Emission ◽  
Intact Brain ◽  
Positron Emission Tomography Radiotracer

Dihydromethidine (DHM) labeled with 18F at the para position of the benzene ring has been developed as a positron emission tomography (PET) radiotracer for non-invasive imaging of reactive oxygen species (ROS).

scholarly journals The oxidation of dehydroascorbic acid and 2,3-diketogulonate by distinct reactive oxygen species

2018 ◽  
Vol 475 (21) ◽  
pp. 3451-3470 ◽  
Author(s):  
Rebecca A. Dewhirst ◽  
Stephen C. Fry
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Hydroxyl Radicals ◽  
Reactive Oxygen ◽  
Dehydroascorbic Acid ◽  
Oxidation Products ◽  
Oxygen Species ◽  
H2o2 Treatment ◽  
Fold Excess

l-Ascorbate, dehydro-l-ascorbic acid (DHA), and 2,3-diketo-l-gulonate (DKG) can all quench reactive oxygen species (ROS) in plants and animals. The vitamin C oxidation products thereby formed are investigated here. DHA and DKG were incubated aerobically at pH 4.7 with peroxide (H2O2), ‘superoxide’ (a ∼50 : 50 mixture of and ), hydroxyl radicals (•OH, formed in Fenton mixtures), and illuminated riboflavin (generating singlet oxygen, 1O2). Products were monitored electrophoretically. DHA quenched H2O2 far more effectively than superoxide, but the main products in both cases were 4-O-oxalyl-l-threonate (4-OxT) and smaller amounts of 3-OxT and OxA + threonate. H2O2, but not superoxide, also yielded cyclic-OxT. Dilute Fenton mixture almost completely oxidised a 50-fold excess of DHA, indicating that it generated oxidant(s) greatly exceeding the theoretical •OH yield; it yielded oxalate, threonate, and OxT. 1O2 had no effect on DHA. DKG was oxidatively decarboxylated by H2O2, Fenton mixture, and 1O2, forming a newly characterised product, 2-oxo-l-threo-pentonate (OTP; ‘2-keto-l-xylonate’). Superoxide yielded negligible OTP. Prolonged H2O2 treatment oxidatively decarboxylated OTP to threonate. Oxidation of DKG by H2O2, Fenton mixture, or 1O2 also gave traces of 4-OxT but no detectable 3-OxT or cyclic-OxT. In conclusion, DHA and DKG yield different oxidation products when attacked by different ROS. DHA is more readily oxidised by H2O2 and superoxide; DKG more readily by 1O2. The diverse products are potential signals, enabling organisms to respond appropriately to diverse stresses. Also, the reaction-product ‘fingerprints’ are analytically useful, indicating which ROS are acting in vivo.

Extremely enhanced contaminant decomposition catalyzed by hemin via the coupling of persistent free radicals and ascorbic acid

2015 ◽  
Vol 51 (89) ◽  
pp. 16139-16142 ◽  
Author(s):  
Yuyuan Yao ◽  
Bin Jiang ◽  
Yajun Mao ◽  
Juan Chen ◽  
Zhenfu Huang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Free Radicals ◽  
Reactive Oxygen ◽  
Environmental Pollutant ◽  
Ros Generation ◽  
Oxygen Species ◽  
Positive Role ◽  
Rate Enhancement

A positive role of PFRs in enhancing reactive oxygen species (ROS) generation for an extreme rate enhancement in environmental pollutant decomposition is reported.

Ascorbic acid improves mitochondrial function in liver of arsenic-treated rat

2010 ◽  
Vol 26 (5) ◽  
pp. 265-272 ◽  
Author(s):  
Sohini Singh ◽  
Suresh Vir Singh Rana
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Mitochondrial Function ◽  
Caspase 3 ◽  
Succinic Dehydrogenase ◽  
Reactive Oxygen ◽  
Ultrastructural Changes ◽  
Arsenic Toxicity ◽  
Oxygen Species

Arsenic is an ubiquitous and well-documented carcinogenic metalloid. The most common source of arsenic is drinking water. The mechanism of arsenic toxicity in a cell has historically been centered around its inhibitory effects on cellular respiration and mitochondrial injury. Ascorbic acid, a low molecular weight, water-soluble antioxidant, improves the reduced glutathione (GSH) status by recycling oxidized glutathione. Ascorbic acid can improve mitochondrial function by improving the thiol status; thereby preventing reactive oxygen species— mediated damage to liver as well as kidney. Ascorbic acid has been shown to protect membrane and other cellular compartments by regenerating vitamin E. Therefore, ascorbic acid seems to be a suitable protective factor against arsenic toxicity. Present reports describe the effect of ascorbic acid on oxidative phosphorylation, adenosine triphosphatase (ATPase), succinic dehydrogenase, caspase-3 and apoptosis in the liver of rats treated with arsenic trioxide (AsIII). Ultrastructural changes in the mitochondria have also been reported. We show that cotreatments with ascorbic acid and AsIII improve mitochondrial structure and function. We attribute these improvements mainly to antioxidative role of ascorbic acid. Apoptosis was restricted due to caspase-3 inhibition. Ascorbic acid could protect DNA from the attack of reactive oxygen species generated by AsIII. Consequently its events led to improved ADP:O ratio, normalized ATPase activity and restored the activity of succinic dehydrogenase. Overall, results support the protective role of ascorbic acid against As III-induced liver injury.

scholarly journals The Synthesis of Ascorbic Acid in Rice Roots Plays an Important Role in the Salt Tolerance of Rice by Scavenging ROS

2018 ◽  
Vol 19 (11) ◽  
pp. 3347 ◽  
Author(s):  
Yayun Wang ◽  
Hui Zhao ◽  
Hua Qin ◽  
Zixuan Li ◽  
Hai Liu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Rice Roots ◽  
Key Factor ◽  
Rna Interfering

The root plays an important role in the responses of plants to stresses, but the detailed mechanisms of roots in stress responses are still obscure. The GDP-mannose pyrophosphate synthetase (GMPase) OsVTC1-3 is a key factor of ascorbic acid (AsA) synthesis in rice roots. The present study showed that the transcript of OsVTC1-3 was induced by salt stress in roots, but not in leaves. Inhibiting the expression of OsVTC1-3 by RNA interfering (RI) technology significantly impaired the tolerance of rice to salt stress. The roots of OsVTC1-3 RI plants rapidly produced more O2−, and later accumulated amounts of H2O2 under salt stress, indicating the impaired tolerance of OsVTC1-3 RI plants to salt stress due to the decreasing ability of scavenging reactive oxygen species (ROS). Moreover, exogenous AsA restored the salt tolerance of OsVTC1-3 RI plants, indicating that the AsA synthesis in rice roots is an important factor for the response of rice to salt stress. Further studies showed that the salt-induced AsA synthesis was limited in the roots of OsVTC1-3 RI plants. The above results showed that specifically regulating AsA synthesis to scavenge ROS in rice roots was one of important factors in enhancing the tolerance of rice to salt stress.

scholarly journals POSSIBLE PREVENTION OF REACTIVE OXYGEN SPECIES INDUCED HUMAN TRABECULAR MESHWORK CELL DAMAGE BY RESVERATROL AND ASCORBIC ACID.

2019 ◽  
Vol 26 (07) ◽  
pp. 1036-1041
Author(s):  
Muhammad Yaqoob Shahani ◽  
Umbreen Bano ◽  
Shazia Begum Shahani ◽  
Pashmina Shaikh ◽  
Sameena Gul Memon ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Cell Viability ◽  
Trabecular Meshwork ◽  
Cell Metabolism ◽  
Cell Activity ◽  
Reactive Oxygen ◽  
Research Centre ◽  
Oxygen Species ◽  
Trabecular Meshwork Cells

Objectives: To analyze the antioxidant activity of Resveratrol and Ascorbic Acid against hydrogen peroxide (an oxidant) mediated cell injury of human trabecular meshwork cells. Study Design: Experimental study. Setting: Molecular Biology Laboratory at Medical Research Centre, Liaquat University of Medical & Health Sciences, Jamshoro. Period: Six months. Materials and Methods: Human Trabecular Meshwork cells were purchased from ScienCell Research Laboratories, USA. TM cell metabolism, TM cell viability and Reactive oxygen species were detected by standard methods in co- and pre- treated TM cells. Results: A significant reduction in TM cell metabolism was observed approximating 61% at 1.0 mM H2O2 compared to Ascorbate – 99% and Resveratrol 99% (p=0.0001). Resveratrol was more effective than Ascorbate even at 4.0 mM H2O2, the TM cell activity was noted 76%. Compared to H2O2- treated TM cells, resveratrol improved mitochondrial function upto 4.0 mM H2O2 (76%). Compared to co-treatment, the pretreatment shows similar results except at 4.0 mM H2O2. At 4.0 mM H2O2 the pre-treat TM cell metabolic activity was found as 11%, 31% and 47% compared to co-treat as 9%, 31% and 76% in controls, ascorbate and resveratrol groups respectively (p<0.05). Resveratrol shows significant decrease in viability was seen in controls compared to Ascorbate and Resveratrol groups. Cell viability showed statistically significant differences at 2.0 and 4.0 mM H2O2 compared to controls (P=0.0001). For reactive oxygen species (ROS), cells were incubated and with Ascorbate and Resveratrol for 24 hours and TM cells were treated with 0.0mM, 0.5 mM, 1.0 mM, 2.0mM and 4.0mM H2O2. Significant decrease in ROS was noted by Resveratrol compared to Ascorbate. Conclusions: Resveratrol and Ascorbate may prove useful in preventing and delaying the glaucoma, and timely institution of these anti – oxidants may help maintain trabecular meshwork functions and prevent visual loss.

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