Evidence of In Vivo Peroxynitrite Formation in Patients With Colorectal Carcinoma, Higher Plasma Nitrate/Nitrite Levels, and Lower Protection Against Oxygen Free Radicals

2000 ◽  
Vol 30 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Erika Szaleczky ◽  
László Prónai ◽  
Hiroe Nakazawa ◽  
Zsolt Tulassay
Keyword(s):  
Free Radicals ◽  
Colorectal Carcinoma ◽  
Oxygen Free Radicals ◽  
Plasma Nitrate

Ethane production as a measure of lipid peroxidation after renal ischemia

1986 ◽  
Vol 251 (5) ◽  
pp. F839-F843 ◽  
Author(s):  
M. S. Paller ◽  
R. P. Hebbel
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Superoxide Radical ◽  
Oxygen Free Radicals ◽  
Tissue Injury ◽  
Renal Ischemia ◽  
Radical Scavenger ◽  
Base Line ◽  
Ethane Production

After renal ischemia, oxygen free radicals are formed and produce tissue injury, in large part, through peroxidation of polyunsaturated fatty acids. We used an in vivo method to monitor lipid peroxidation after renal ischemia, the measurement of ethane in expired gas, to determine the time course of lipid peroxidation and the effect of several agents to limit lipid peroxidation after renal ischemia. In anesthetized rats there was no significant increase in ethane production during 60 min of renal ischemia. During the first 10 min of renal reperfusion, there was a prompt increase in ethane production from 2.9 +/- 1.3 to 6.3 +/- 1.9 pmol/min (P less than 0.05). Ethane production was significantly increased during the first 50 min of reperfusion and then rapidly tapered to base-line levels. Preischemic administration of allopurinol to prevent superoxide radical generation or the superoxide radical scavenger superoxide dismutase prevented the increase in ethane production during postischemic reperfusion. These studies confirm that there is increase lipid peroxidation following renal ischemia that can be prevented by agents which limit the formation or accumulation of oxygen free radicals. This in vivo method for measuring lipid peroxidation could also be employed to study the effects of ischemia on lipid peroxidation in other organs, as well as to monitor lipid peroxidation in other forms of injury.

scholarly journals Pharmacological Effects of Salvianolic Acid B Against Oxidative Damage

2020 ◽  
Vol 11 ◽  
Author(s):  
Zhun Xiao ◽  
Wei Liu ◽  
Yong-ping Mu ◽  
Hua Zhang ◽  
Xiao-ning Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Free Radicals ◽  
Clinical Application ◽  
Oxygen Free Radicals ◽  
Salvianolic Acid B ◽  
Related Factor ◽  
Pharmacological Effects ◽  
Hydrogen Atoms ◽  
Salvianolic Acid

Salvianolic acid B (Sal B) is one of the main active ingredients of Salvia miltiorrhiza, with strong antioxidant effects. Recent findings have shown that Sal B has anti-inflammatory, anti-apoptotic, anti-fibrotic effects and can promote stem cell proliferation and differentiation, and has a beneficial effect on cardiovascular and cerebrovascular diseases, aging, and liver fibrosis. Reactive oxygen species (ROS) include oxygen free radicals and oxygen-containing non-free radicals. ROS can regulate cell proliferation, survival, death and differentiation to regulate inflammation, and immunity, while Sal B can scavenge oxygen free radicals by providing hydrogen atoms and reduce the production of oxygen free radicals and oxygen-containing non-radicals by regulating the expression of antioxidant enzymes. The many pharmacological effects of Sal B may be closely related to its elimination and inhibition of ROS generation, and Nuclear factor E2-related factor 2/Kelch-like ECH-related protein 1 may be the core link in its regulation of the expression of antioxidant enzyme to exert its antioxidant effect. What is confusing and interesting is that Sal B exhibits the opposite mechanisms in tumors. To clarify the specific target of Sal B and the correlation between its regulation of oxidative stress and energy metabolism homeostasis will help to further understand its role in different pathological conditions, and provide a scientific basis for its further clinical application and new drug development. Although Sal B has broad prospects in clinical application due to its extensive pharmacological effects, the low bioavailability is a serious obstacle to further improving its efficacy in vivo and promoting clinical application. Therefore, how to improve the availability of Sal B in vivo requires the joint efforts of many interdisciplinary subjects.

Effect of Hyperbaric Oxygen Treatment on Nitric Oxide and Oxygen Free Radicals in Rat Brain

2000 ◽  
Vol 83 (4) ◽  
pp. 2022-2029 ◽  
Author(s):  
Ikram M. Elayan ◽  
Milton J. Axley ◽  
Paruchuri V. Prasad ◽  
Stephen T. Ahlers ◽  
Charles R. Auker
Keyword(s):  
Nitric Oxide ◽  
Free Radicals ◽  
Rat Brain ◽  
Hyperbaric Oxygen ◽  
High Pressures ◽  
Oxygen Free Radicals ◽  
In Vivo Microdialysis ◽  
Sprague Dawley ◽  
Fourfold Increase

Oxygen (O2) at high pressures acts as a neurotoxic agent leading to convulsions. The mechanism of this neurotoxicity is not known; however, oxygen free radicals and nitric oxide (NO) have been suggested as contributors. This study was designed to follow the formation of oxygen free radicals and NO in the rat brain under hyperbaric oxygen (HBO) conditions using in vivo microdialysis. Male Sprague-Dawley rats were exposed to 100% O2 at a pressure of 3 atm absolute for 2 h. The formation of 2,3-dihydroxybenzoic acid (2,3-DHBA) as a result of perfusing sodium salicylate was followed as an indicator for the formation of hydroxyl radicals. 2,3-DHBA levels in hippocampal and striatal dialysates of animals exposed to HBO conditions were not significantly different from controls. However, rats treated under the same conditions showed a six- and fourfold increase in nitrite/nitrate, break down products of NO decomposition, in hippocampal and striatal dialysates, respectively. This increase was completely blocked by the nitric oxide synthase (NOS) inhibitor l-nitroarginine methyl ester (l-NAME). Using neuronal NOS, we determined the NOS O2 K m to be 158 ± 28 (SD) mmHg, a value which suggests that production of NO by NOS would increase approximately four- to fivefold under hyperbaric O2 conditions, closely matching the measured increase in vivo. The increase in NO levels may be partially responsible for some of the detrimental effects of HBO conditions.

Effect of ethanol in vivo on enzymes which detoxify oxygen free radicals

1989 ◽  
Vol 7 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Nicholas J. Schisler ◽  
Shiva M. Singh
Keyword(s):  
Free Radicals ◽  
Oxygen Free Radicals

scholarly journals Formation of peroxides in amino acids and proteins exposed to oxygen free radicals

1993 ◽  
Vol 289 (3) ◽  
pp. 743-749 ◽  
Author(s):  
S Gebicki ◽  
J M Gebicki
Keyword(s):  
Amino Acids ◽  
Free Radicals ◽  
Oxygen Free Radicals ◽  
Radiation Energy ◽  
Protonated Form ◽  
Isoleucine Leucine ◽  
Protein Peroxidation ◽  
Dilute Aqueous Solutions ◽  
Kinetics Of

Dilute aqueous solutions of BSA or lysozyme gave positive tests for peroxides after exposure to reactive oxygen species. The reactive species were generated by gamma-irradiation, reduction of H2O2 with Fe2+ ions or thermal decomposition of an azo compound. Peroxides were assayed by an iodometric method. Identification of the new groups as hydroperoxides was confirmed by their ability to oxidize a range of compounds and by the kinetics of their reaction with iodide. The hydroperoxide groups were bound to the proteins and their yields (G values) corresponded to 1.2 -OOH groups per 100 eV of radiation energy absorbed for BSA, and 0.8 for lysozyme. The oxygen free radicals effective in protein peroxidation were the hydroxyl and organic peroxyl, but not superoxide or its protonated form. The efficiency of BSA peroxidation initiated by the hydroxyl radicals was 40%. Protein peroxides decayed spontaneously with a half-life of about 1.5 days at 20 degrees C. Exposure of the common amino acids to hydroxyl free radicals showed that six of them (glutamate, isoleucine, leucine, lysine, proline and valine) were peroxidized with similar efficiency to the proteins, whereas the rest were inert or much less susceptible. These results suggest that some proteins may be peroxidized by a variety of agents in vivo and that their subsequent reactions with protective agents, such as ascorbate or glutathione, may decrease the antioxidant potential of cells and tissues.

Auto-oxidation of 5,6,7 ,8-tetrahydroneopterin

Pteridines ◽  
1998 ◽  
Vol 9 (1) ◽  
pp. 26-28
Author(s):  
Toshiyuki Arai ◽  
Hiroko Mori ◽  
Hisanari Ishii ◽  
Toshinori Suzuki ◽  
Shuji Kojima ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Free Radicals ◽  
High Performance ◽  
Oxygen Free Radicals ◽  
Phosphate Buffer Solution ◽  
Reversed Phase ◽  
Buffer Solution ◽  
First Time

Summary Auto-oxidation of 5,6,7,8-tetrahydroneopterin (NPH4 ) in phosphate buffer solution (PBS) was examined using reversed-phase high-performance liquid chromatography. In the chromatograms obtained every 30 min after NPH4 was dissolved in PBS, the peak of NPH4 gradually decreased and almost disappeared 90 min after the dissolution. In contrast, another peak of an unidentified substance (one of dihydroneopterins), appeared from the first time, gradually increased and became most dominant among various peaks 60 min after. The peak of 7,8-dihydroneopterin (7,8-NPH2) appeared 30 min after and gradually increased, but its height was less than that of the above-mentioned peak from first to last. These results indicate that NPH4 is readily oxidized by dissolved oxygen in PBS to produce 7,8-NPH2 and other dihydroneopterins before the reaction with oxygen free radicals and that the substances which actually serve as antioxidants in vivo are these dihydroneopterins.

Highly Potent rhenium(I) Tricarbonyl Complexes with Dual Anticancer and Anti-Angiogenic Activity Against Colorectal Carcinoma

2020 ◽  
Author(s):  
Joachim Delasoie ◽  
Aleksandar Pavic ◽  
Noémie Voutier ◽  
Sandra Vojnovic ◽  
Aurélien Crochet ◽  
...  
Keyword(s):  
Colorectal Carcinoma ◽  
Anticancer Drugs ◽  
Xenograft Model ◽  
Therapeutic Window ◽  
Low Doses ◽  
Sunitinib Malate ◽  
Angiogenic Activity ◽  
Antimetastatic Activity ◽  
Clinical Drugs

Synthesized and characterized a series of rhenium(I) trycarbonyl-based complexes with increased lipophilicity. Two of these novel compounds were discovered to possess remarkable anticancer, anti-angiogenic and antimetastatic activity <i>in vivo</i> (zebrafish-human CRC xenograft model), being effective at very low doses (1-3 µM). At doses as high as 250 µM the complexes did not provoke toxicity issues encountered in clinical anticancer drugs (cardio-, hepato-, and myelotoxicity). The two compounds exceed the antiproliferative and anti-angiogenic potency of clinical drugs cisplatin and sunitinib-malate, and display a large therapeutic window.

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