scholarly journals Selenium-Catalyzed Reduction of Hydroperoxides in Chemistry and Biology

Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1560
Author(s):  
Laura Orian ◽  
Leopold Flohé
Keyword(s):  
Metabolic Regulation ◽  
Redox Regulation ◽  
Antioxidant Defense ◽  
Catalytic Efficiency ◽  
Antioxidant Defense System ◽  
Nucleophilic Attack ◽  
Glutathione Peroxidases ◽  
H2o2 Reduction ◽  
Thioredoxin Reductases ◽  
Peroxide Bond

Among the chalcogens, selenium is the key element for catalyzed H2O2 reduction. In organic synthesis, catalytic amounts of organo mono- and di-selenides are largely used in different classes of oxidations, in which H2O2 alone is poorly efficient. Biological hydroperoxide metabolism is dominated by peroxidases and thioredoxin reductases, which balance hydroperoxide challenge and contribute to redox regulation. When their selenocysteine is replaced by cysteine, the cellular antioxidant defense system is impaired. Finally, classes of organoselenides have been synthesized with the aim of mimicking the biological strategy of glutathione peroxidases, but their therapeutic application has so far been limited. Moreover, their therapeutic use may be doubted, because H2O2 is not only toxic but also serves as an important messenger. Therefore, over-optimization of H2O2 reduction may lead to unexpected disturbances of metabolic regulation. Common to all these systems is the nucleophilic attack of selenium to one oxygen of the peroxide bond promoting its disruption. In this contribution, we revisit selected examples from chemistry and biology, and, by using results from accurate quantum mechanical modelling, we provide an accurate unified picture of selenium’s capacity of reducing hydroperoxides. There is clear evidence that the selenoenzymes remain superior in terms of catalytic efficiency.

scholarly journals Looking Back at the Early Times of Redox Biology

2020 ◽  
Author(s):  
Leopold Flohe
Keyword(s):  
Hydrogen Peroxide ◽  
Metabolic Regulation ◽  
Redox Regulation ◽  
Biological Systems ◽  
Lipid Hydroperoxide ◽  
Nitrogen Monoxide ◽  
Redox Biology ◽  
Glutathione Peroxidases ◽  
And Function ◽  
Heme Peroxidases

The beginnings of redox biology are recalled with special emphasis on formation, metabolism and function of reactive oxygen and nitrogen species in mammalian systems. The review covers the early history of heme peroxidases and the metabolism of hydrogen peroxide, the discovery of selenium as integral part of glutathione peroxidases, which expanded the scope of the field to other hydroperoxides including lipid hydroperoxide, the discovery of superoxide dismutases and superoxide radicals in biological systems and their role in host defense, tissue damage, metabolic regulation and signaling, the identification of the endothelial-derived relaxing factor as the nitrogen monoxide radical and its physiological and pathological implications. The article highlights the perception of hydrogen peroxide and other hydroperoxides as signaling molecules, which marks the beginning of the flourishing fields of redox regulation and redox signaling. Final comments describe the development of the redox language. In the 18th and 19th century, it was highly individualized and hard to translate into modern terminology. In the 20th century, the redox language co-developed with the chemical terminology and became clearer. More recently, the introduction and inflationary use of poorly defined terms has unfortunately impaired the understanding of redox events in biological systems.

scholarly journals Looking Back at the Early Stages of Redox Biology

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1254
Author(s):  
Leopold Flohé
Keyword(s):  
Hydrogen Peroxide ◽  
Metabolic Regulation ◽  
Redox Regulation ◽  
Biological Systems ◽  
Nitrogen Monoxide ◽  
Lipid Hydroperoxides ◽  
Redox Biology ◽  
Glutathione Peroxidases ◽  
And Function ◽  
Heme Peroxidases

The beginnings of redox biology are recalled with special emphasis on formation, metabolism and function of reactive oxygen and nitrogen species in mammalian systems. The review covers the early history of heme peroxidases and the metabolism of hydrogen peroxide, the discovery of selenium as integral part of glutathione peroxidases, which expanded the scope of the field to other hydroperoxides including lipid hydroperoxides, the discovery of superoxide dismutases and superoxide radicals in biological systems and their role in host defense, tissue damage, metabolic regulation and signaling, the identification of the endothelial-derived relaxing factor as the nitrogen monoxide radical (more commonly named nitric oxide) and its physiological and pathological implications. The article highlights the perception of hydrogen peroxide and other hydroperoxides as signaling molecules, which marks the beginning of the flourishing fields of redox regulation and redox signaling. Final comments describe the development of the redox language. In the 18th and 19th century, it was highly individualized and hard to translate into modern terminology. In the 20th century, the redox language co-developed with the chemical terminology and became clearer. More recently, the introduction and inflationary use of poorly defined terms has unfortunately impaired the understanding of redox events in biological systems.

POSSIBILITIES OF ANTIOXIDANT PROTECTION IN PATIENTS WITH SUPERIOR HYPERPLASIA OF THE PEDESTAL GLAND AND ACCOMPANYING CHRONIC POSTATITIS

2020 ◽  
pp. 8-11
Author(s):  
Павел Георгиевич Осипов ◽  
Андрей Александрович Береш ◽  
Юрий Сергеевич Ханин ◽  
Олеся Игоревна Некрылова
Keyword(s):  
Lipid Peroxidation ◽  
Chronic Prostatitis ◽  
Antioxidant Defense ◽  
Prostate Gland ◽  
Antioxidant Defense System ◽  
Complex Treatment ◽  
Traditional Treatment ◽  
Important Place ◽  
Antioxidant Defense Systems ◽  
Benign Hyperplasia

Несмотря на достигнутые успехи в диагностике и лечении, на сегодняшний день проблема хронического простатита у пациентов с доброкачественной гиперплазией простаты продолжает оставаться актуальной. Тем временем, выздоровление или же стойкая ремиссия хронического простатита наступает только у 30-35% больных, которые получают традиционное лечение. В патогенезе хронического простатита важное место занимают мембранопатологические процессы, которые обусловлены активацией перекисного окисления липидов и нарушением состояния антиоксидантной системы защиты. У больных с хроническим простатитом и доброкачественной гиперплазией простаты наблюдается существенное усиление процессов липопероксидации на фоне сниженной функциональной способности антиоксидантных систем защиты организма. Поэтому равновесие в оксидантно-антиоксидантной системе является важным звеном в поддержании гомеостаза и, в частности, при патологии предстательной железы, предопределяет включение в комплексное лечение средств антиоксидантного действия. Перспективным можно считать применение препаратов с высоким содержанием биофлавоноидов и антиоксидантных витаминов. Включение в комплексное лечение таких пациентов препарата Кверцетина приводит к сокращению сроков нормализации клинико-лабораторных проявлений заболевания благодаря восстановлению равновесия между перекисным окислением липидов и состоянием антиоксидантной системы защиты Despite the successes achieved in the diagnosis and treatment, to date, the problem of chronic progression in patients with benign hyperplasia of the growth continues to remain relevant. Meanwhile, recovery or persistent remission of chronic prostatitis occurs only in 30-35% of patients who receive traditional treatment. In the pathogenesis of chronic prostatitis, membrane-pathological processes take an important place, which are caused by the activation of lipid peroxidation and impaired state of the antioxidant defense system. In patients with chronic prostate and benign hyperplasia, a significant increase in lipoperoxidation processes is observed against the background of a reduced functional ability of antioxidant defense systems. Therefore, the equilibrium in the oxidant-antioxidant system is an important link in the maintenance of homeostasis and, in particular, with the pathology of the prostate gland, allows the inclusion of antioxidant drugs in the complex treatment. The use of drugs with a high content of bioflavonoids and antioxidant vitamins can be considered promising. The inclusion of such patients in the complex treatment of the drug Quercetin leads to a reduction in the normalization period of the clinical and laboratory manifestations of the disease due to the restoration of the equilibrium between the peroxidation of the lipid peroxidation system and the state of lipid peroxidation

Indicators of the antioxidant system in the long-term period after acute mercury nitrate poisoning in the experiment

2020 ◽  
pp. 36-41
Author(s):  
E. G. Batotsyrenova ◽  
O. A. Vakunenkova ◽  
E. A. Zolotoverkhaya ◽  
V. A. Kashuro ◽  
T. A. Kostrova ◽  
...  
Keyword(s):  
Antioxidant System ◽  
Antioxidant Defense ◽  
Reduced Glutathione ◽  
Antioxidant Defense System ◽  
Mercury Content ◽  
The State ◽  
Cytotoxic Effects ◽  
Entire Study ◽  
Mercury Nitrate

The article presents experimental data on the state of the antioxidant system in red blood cells of white outbred rats 1 and 3 months after acute mercury nitrate poisoning with a semilethal dose. It has been established that this form of intoxication is accompanied by pronounced changes in the state of the antioxidant defense system in erythrocytes of poisoned animals (a decrease in the concentration of reduced glutathione, a decrease in the activity of superoxide dismutase and glutathione peroxidase, and an increase in the concentration of lipid peroxidation products).It has been shown that the mercury content in the blood of experimental animals remains elevated during the entire study period.The results obtained indicate the importance of impaired functioning of the antioxidant system in the implementation of long-term consequences of acute mercury poisoning. The reasons for the occurrence of these biochemical shifts and their role in the development of the long-term cytotoxic effects of mercury nitrate are discussed.

STUDY OF THE COMBINED INFLUENCE OF SODIUM THIOPENTAL AND DELTA SLEEP-INDUCING PEPTIDE ON ANTIOXIDANT DEFENSE SYSTEM IN RATS

2016 ◽  
pp. 49-52
Author(s):  
A. V. Shvetsov ◽  
E. G. Batotsyrenova ◽  
N. A. Dyuzhikova ◽  
V. A. Kashuro ◽  
N. V. Lapina ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Antioxidant Defense ◽  
Antioxidant Defense System ◽  
Time Interval ◽  
Sodium Thiopental ◽  
Antioxidant Defense Enzymes ◽  
Delta Sleep ◽  
Thiopental Coma ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Delta Sleep Inducing Peptide

A biochemical investigation was performed into activity of rat antioxidant defense enzymes at different time interval after administration of sodium thiopental and delta-sleep-inducing peptide (DSIP). It was shown that thiopental coma was accompanied by a decreased level of superoxide dismutase ( 6 and 24 h after exposure) and increased level of caspase-3 ( 6 h after exposure) in the rat blood plasma. A pharmacological correction with DSIP induced a decrease of the level of superoxide dismutase ( 6 and 24 h after exposure), glutathione peroxidase and glucose 6-phosphate dehydrogenase (after 6h).

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