Catalase: A Potential Pharmacologic Target for Hydrogen Peroxide in the Treatment of COVID-19.

Background: Acute respiratory distress syndrome in the elderly with COVID-19 complicated by airway obstruction with sputum and mucus, and cases of asphyxia with blood, serous fluid, pus, or meconium in newborns and people of different ages can sometimes cause hypoxemia and death from hypoxic damage to brain cells, because the medical standard does not include intrapulmonary injections of oxygen-producing solutions. The physical-chemical repurposing of hydrogen peroxide from an antiseptic to an oxygen-producing antihypoxant offers hope for the development of new drugs.

Methods: This manuscript is a meta-analysis performed according to PRISMA guidelines.

Effect of Cytochrome C on the Conductance of Asolectin Membranes and the Occurrence of Through Pores at Different pHs.

The study of the electrical parameters of asolectin bilayer lipid membranes in the presence of cytochrome c (cyt c) at various concentrations showed that an increase in the concentration of cyt c leads to an increase in the membrane conductance and the appearance of through pores. The studied membranes did not contain cardiolipin, which is commonly used in studying the effect of cyt c on membrane permeability. In the presence of cyt c, discrete current fluctuations were recorded.

Hypothetical mechanism of light action on nitric oxide physiological effects.

Nitric oxide is a universal cellular mediator. It is involved in many physiological processes, including those induced by light. The disability for complete analysis of the nitric oxide metabolites in tissues prevents the exact understanding of the role of NO in a particular process.

Effects of Laser Radiation on Mitochondria and Mitochondrial Proteins Subjected to Nitric Oxide.

The biological roles of heme and nonheme nitrosyl complexes in physiological and pathophysiological conditions as metabolic key players are considered in this study. Two main physiological functions of protein nitrosyl complexes are discussed-(1) a depot and potential source of free nitric oxide (NO) and (2) a controller of crucial metabolic processes. The first function is realized through the photolysis of nitrosyl complexes (of hemoglobin, cytochrome , or mitochondrial iron-sulfur proteins).

Nitrite and nitroso compounds can serve as specific catalase inhibitors.

Objective: We present evidence that nitrite and nitrosothiols, nitrosoamines and non-heme dinitrosyl iron complexes can reversibly inhibit catalase with equal effectiveness.

Methods: Catalase activity was evaluated by the permanganatometric and calorimetric assays.

Results: This inhibition is not the result of chemical transformations of these compounds to a single inhibitor, as well as it is not the result of NO release from these substances (as NO traps have no effect on the extent of inhibition).

Peroxidative permeabilization of liposomes induced by cytochrome c/cardiolipin complex.

Interaction of cytochrome c with mitochondrial cardiolipin converting this electron transfer protein into peroxidase is accepted to play an essential role in apoptosis. Cytochrome c/cardiolipin peroxidase activity was found here to cause leakage of carboxyfluorescein, sulforhodamine B and 3-kDa (but not 10-kDa) fluorescent dextran from liposomes. A marked decrease in the amplitude of the autocorrelation function was detected with a fluorescence correlation spectroscopy setup upon incubation of dye-loaded cardiolipin-containing liposomes with cytochrome c and H2O2, thereby showing release of fluorescent markers from liposomes.

Are the mitochondrial respiratory complexes blocked by NO the targets for the laser and LED therapy?

Effects of laser (442 and 532 nm) and light-emitting diode (LED) (650 nm) radiation on mitochondrial respiration and mitochondrial electron transport rate (complexes II-III and IV) in the presence of nitric oxide (NO) were investigated. It was found that nitric oxide (300 nM-10 μM) suppresses mitochondrial respiration. Laser irradiation of mitochondria (442 nm, 3 J cm(-2)) partly restored mitochondrial respiration (approximately by 70 %).

Effects of low-level laser therapy on mitochondrial respiration and nitrosyl complex content.

Among the photochemical reactions responsible for therapeutic effects of low-power laser radiation, the photolysis of nitrosyl iron complexes of iron-containing proteins is of primary importance. The purpose of the present study was to compare the effects of blue laser radiation on the respiration rate and photolysis of nitrosyl complexes of iron-sulfur clusters (NO-FeS) in mitochondria, subjected to NO as well as the possibility of NO transfer from NO-FeS to hemoglobin. It was shown that mitochondrial respiration in State 3 (V3) and State 4 (V4), according to Chance, dramatically decreased in the presence of 3 mM NO, but laser radiation (λ = 442 nm, 30 J/cm(2)) restored the respiration rates virtually to the initial level.

Unusual peroxidase activity of polynitroxylated pegylated hemoglobin: Elimination of H(2)O(2) coupled with intramolecular oxidation of nitroxides.

Polynitroxylated hemoglobin (Hb(AcTPO)(12)) has been developed as a hemoglobin-based oxygen carrier. While Hb(AcTPO)(12) has been shown to exert beneficial effects in a number of models of oxidative injury, its peroxidase activity has not been characterized thus far. In the blood stream, Hb(AcTPO)(12) undergoes reduction by ascorbate to its hydroxylamine form Hb(AcTPOH)(12).

Evaluation of cytochrome c affinity to anionic phospholipids by means of surface plasmon resonance.

We attempted to evaluate the affinity of the anionic phospholipids to cytochrome c by means of surface plasmon resonance (SPR) technique and to correlate it with the cytochrome c active site alterations and peroxidase activity. Our experiments showed a strong interdependence between the phospholipid fatty acid saturation degree, the active site structure alterations and peroxidase activity of the cytochrome c phospholipid complex. Cytochrome c peroxidase activity and Trp59 fluorescence increase in the sequence of phosphatidyl choline (PC)-->phosphatidylserine (PS)-->cardiolipin (CL)-->phosphatidic acid (PA).

Illumination with blue light reactivates respiratory activity of mitochondria inhibited by nitric oxide, but not by glycerol trinitrate.

Nitric oxide (NO) is known to inhibit mitochondrial respiration reversibly. This study aimed at clarifying whether low level illumination at specific wavelengths recovers mitochondrial respiration inhibited by NO and glycerol-trinitrate (GTN), a clinically used NO mimetic. NO fully inhibited respiration of liver mitochondria at concentrations occurring under septic shock.

Blue laser light increases perfusion of a skin flap via release of nitric oxide from hemoglobin.

It has recently been shown that nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to low-level blue laser irradiation, suggesting that laser irradiation can facilitate the release of biologically active nitric oxide (NO), which can affect tissue perfusion. The aim of this study was to evaluate the therapeutic value of blue laser irradiation for local tissue perfusion after surgical intervention. Blood was withdrawn from a rat, exposed to NO and infused back to the same rat or used for in vitro experiments.

Peroxidase activity and structural transitions of cytochrome c bound to cardiolipin-containing membranes.

During apoptosis, cytochrome c (cyt c) is released from intermembrane space of mitochondria into the cytosol where it triggers the caspase-dependent machinery. We discovered that cyt c plays another critical role in early apoptosis as a cardiolipin (CL)-specific oxygenase to produce CL hydroperoxides required for release of pro-apoptotic factors [Kagan, V. E.

Nitric oxide inhibits peroxidase activity of cytochrome c.cardiolipin complex and blocks cardiolipin oxidation.

The increased production of NO during the early stages of apoptosis indicates its potential involvement in the regulation of programmed cell death through yet to be identified mechanisms. Recently, an important role for catalytically competent peroxidase form of pentacoordinate cytochrome c (cyt c) in a complex with a mitochondria-specific phospholipid, cardiolipin (CL), has been demonstrated during execution of the apoptotic program. Because the cyt c.

Cytochrome c acts as a cardiolipin oxygenase required for release of proapoptotic factors.

Programmed death (apoptosis) is turned on in damaged or unwanted cells to secure their clean and safe self-elimination. The initial apoptotic events are coordinated in mitochondria, whereby several proapoptotic factors, including cytochrome c, are released into the cytosol to trigger caspase cascades. The release mechanisms include interactions of B-cell/lymphoma 2 family proteins with a mitochondria-specific phospholipid, cardiolipin, to cause permeabilization of the outer mitochondrial membrane.

Carnivorous pitcher plant uses free radicals in the digestion of prey.

A study of the involvement of free oxygen radicals in trapping and digestion of insects by carnivorous plants was the main goal of the present investigation. We showed that the generation of oxygen free radicals by pitcher fluid of Nepenthes is the first step of the digestion process, as seen by EPR spin trapping assay and gel-electrophoresis. The EPR spectrum of N.

Arachidonic acid-induced carbon-centered radicals and phospholipid peroxidation in cyclo-oxygenase-2-transfected PC12 cells.

Cyclo-oxygenase-2 (COX-2) is believed to induce neuronal oxidative stress via production of radicals. While oxygen radicals are not directly involved in COX-2-catalytic cycle, superoxide anion radicals have been repeatedly reported to play a critical role in COX-2-associated oxidative stress. To resolve the controversy, we characterized production of free radicals in PC12 cells in which COX-2 expression was manipulated either genetically or by direct protein transfection and compared them with those generated by a recombinant COX-2 in a cell-free system.

Increased S-nitrosothiols and S-nitrosoalbumin in cerebrospinal fluid after severe traumatic brain injury in infants and children: indirect association with intracranial pressure.

Nitric oxide (NO) is implicated in both secondary damage and recovery after traumatic brain injury (TBI). Transfer of NO groups to cysteine sulfhydryls on proteins produces S-nitrosothiols (RSNO). S-nitrosothiols may be neuroprotective after TBI by nitrosylation of N-methyl-D-aspartate receptor and caspases.

Formation of lysophospholipids from unsaturated phosphatidylcholines under the influence of hypochlorous acid.

The formation of lysophosphatidylcholines from unsaturated phosphatidylcholines upon treatment with hypochlorous acid was evaluated by means of MALDI-TOF mass spectrometry and 31P NMR spectroscopy. With an increasing number of double bonds in a fatty acid residue, the yield of lysophosphatidylcholines with a saturated fatty acid residue increased considerably in comparison to the total amount of higher molecular weight products like chlorohydrins and glycols. High amounts of lysophosphatidylcholines were formed from phospholipids containing arachidonic or docosahexaenoic acid residues.

Toward mechanism-based antioxidant interventions: lessons from natural antioxidants.

It is generally accepted that one of the major and important contributions to skin aging, skin disorders, and skin diseases results from reactive oxygen species. More than other tissues, the skin is exposed to numerous environmental chemical and physical agents, such as ultraviolet light, causing oxidative stress. Accelerated cutaneous UV-induced aging, photo aging, is only one of the harmful effects of continual oxygen radical production in the skin.