Effect of vitamin E and vitamin C combination on experimental influenza virus infection.

Successful antioxidant treatment of the so-called "free radical diseases" has been reported in the literature. In this study we examined the preventive effect of vitamin E and vitamin C, alone and in combination, on the damage caused by influenza virus infection (IVI). Male mice (ICR), infected with influenza virus A/2/68/(H3N2) (1.5 of LD(50)), were administered single once-daily doses of vitamin E (60 mg/kg b.w.) and vitamin C (80 mg/kg b.w.) intraperitoneally (3 days before virus inoculation). On the 5th and 7th day, respectively, after virus inoculation, animals were decapitated. Monooxygenase enzyme activity (ethylmorphine N-demethylase, amidopyrin N-demethylase, analgin N-demethylase, aniline hydroxylase, cytochrome P-450 content and NADPH-cytochrome C reductase [CCR]) was determined in liver 9000 x g supernatant. Primary and secondary products of lipid peroxidation (LPO; conjugated dienes [CD] and TBA-reactive substances) were measured in blood plasma, lung and liver 9000 x g supernatant. Vitamin E effectively restored LPO-levels increased by IVI. The effect of vitamin C was similar, but slighter. The combination (vitamin E + C) had greater effect on LPO levels than their separate administration. P-450-dependent monooxygenase activity was significantly restored and more pronounced cytochrome P-450 content and NADPH-CCR activity was noted. The preventive effect of vitamin E was stronger than the effect of vitamin C, but the combination (vitamin E + C) had the strongest effect. The superior protective effect of the combination is probably due to vitamin C's repairing effect on vitamin E's tocopheroxyl radical.

[Study of radicals formed in the interaction of organic hydroperoxides with ferric ions using the spin trap method]. / Issledovanie radikalov, obrazuiushchikhsia pri vzaimodeistvii organicheskikh gidroperekisei s ionami zheleza, metodom spinovykh lovushek.

The mechanism of free radical generation in the reaction of ferrous ion with t-butyl and linolenic acid hydroperoxide was investigated by spin trapping method. The t-butoxyl, methyl, linolenic acid alkoxyl and alkyl radical spin adducts EPR spectra were observed and identified.

[Initiation of nonenzymatic lipid peroxidation in a Fe2+-ascorbate-linolenate system]. / Initsiirovanie nefermentativnogo perekisnogo okisleniialipidov v sisteme Fe2+-askorbat-linolenat.

Using spin trapping method there were discovered and identified the radicals of linolenic acid formed when initiating its peroxidation by the system Fe2+-ascorbate. Mechanism of formation of linolenic acid radicals and their role in initiation of peroxidation were studied. A scheme of reactions of peroxidation initiation in the system Fe2+-ascorbate. linolenic acid is proposed.

[Role of lipid peroxidation in the pathogenesis of arrhythmias and the anti-arrhythmogenic action of antioxidants]. / Rol' perekisnogo okisleniia lipidov v patogeneze aritmii i antiaritmogennoe deistvie antioksidantov.

In the initial phase of its action on the contracting myocardium the inductor of lipid peroxidation (LPO) H2O2 displays marked positive ino- and chronotropic as well as relaxant effects which are, therefore, close to catecholamine effects. Since catecholamines activate LPO it suggests that such activation may be involved in the mechanism of their physiologic action. The prolongation of H2O2 action inevitably leads to the development of bradycardia and bradyarrhythmic arrhythmia which may ultimately end in cardiac arrest. The atrial resistance to H2O2 in animals exposed to stress is considerably diminished: in response to this inductor of LPO such animals develop more pronounced bradyarrythmic arrhythmia and cardiac arrest without the stage of the initially positive inotropic effect. The preincubation of the contracting atrium by HP-6, a LPO inhibitor of the hydroxypyridine class, checks the development of bradyarrhythmic arrhythmia and in many cases prevents cardiac arrest. Taken as a whole these data suggest that LPO activation may play an important role in the pathogenesis of cardiac rhythm disorders which may serve as substantiation for the use of antioxidants in the treatment and prevention of arrhythmias.

[Participation of lipid radicals and active oxygen forms in the peroxidation of microsomal membrane lipids induced by organic hydroperoxides]. / Uchastie perekisnykh radikalov i aktivnykh form kisloroda v perekisnom okislenii lipidov mikrosomal'nykh membran, indutsiruemom organicheskimi gidroperekisiami.

The peroxidative radicals arizing after destruction of exogenous hydroperoxides catalyzed by cytochrome P-450, carried out important functions in induction of lipid peroxidation, dependent on organic hydroperoxides. Only a slight inhibitory effect of singlet oxygen and anion radicals of superoxide on organic hydroperoxide dependent process of lipid peroxidation suggested that these active forms of oxygen participated apparently in lipid peroxidation. The traps of hydroxyl radicals (.OH) did not affect the lipid peroxidation induced by organic hydroperoxides. A mechanism is discussed for generation and function of peroxidative radicals as well as of active oxygen forms in lipid peroxidation, induced by organic hydroperoxides in liver microsomal membranes.

[Peroxidation of lipids in mitochondrial membranes, induced by enzymatic deamination of biogenic amines]. / Perekisnoe okislenie lipidov v mitokhondrial'nykh membranakh, indutsiruemoe fermentativnym dezaminirovaniem biogennykh aminov.

In presence of ferrous cations and ascorbate lipid peroxidation in mitochondrial membranes has been induced by incubation of fragments of the membrane devoid of catalase activity with amines which are substrates of monoamine oxidases of the B type (2-phenyl ethylamine, benzylamine) or transformed monoamine oxidases of type A (cadaverine). In the samples containing both cadaverine and benzylamine the highest stimulation of lipid peroxidation was noted. To the contrary, a substrate of the monoamine oxidases of the type A (serotonin) caused under the same conditions an antioxidative effect. The following conditions are obligatory to induce lipid peroxidation in mitochondria by incubation with amines: I. absence of catalase activity in the biomembranes; 2. presence of physiological concentrations of Fe2+. Physiological concentrations of ascorbate or alterations of pH in the samples caused additional stimulation of the lipid peroxidation.

Oxidative stress in patients with beta-thalassemia major.

The aim of this work is to study the level of oxidative stress in blood of beta-thalassemia major patients with transfusional iron overload and chelation therapy as a central pathological process. Beta-thalassemia major results in an increase in the concentration of lipid peroxidation products in blood plasma of more than 100% and in the intensity of chemiluminescence - about 20% in comparison to healthy controls. The activity of the antioxidant enzyme superoxide dismutase in the blood of beta-thalassemia major patients is decreased by more than 30% and the total antioxidant activity is diminished by about 70% compared to controls. Experimental data confirm the progression of oxidative stress in patients with beta-thalassemia major: activation of free radical processes and lipid peroxidation, decreased antioxidant capacity. Strong oxidative damage and essential alternations define these parameters as sensitive markers of oxidative stress in patients with beta-thalassemia major. The combination of effective iron-chelatory agents with natural or synthetic antioxidants can be extremely helpful in clinical practice in the regulation of the antioxidant status of patients with beta-thalassemia major.

Chemiluminescent in vitro estimation of the inhibitory constants of antioxidants ascorbic and uric acids in Fenton's reaction in urine.

The goal of this research was to measure in vitro the inhibitory constants of the antioxidants ascorbic and uric acid in urine, with lucigenin enhanced chemiluminescence (CL) in Fenton's system. Maximum CL emission is registered in urine containing H2O2 (5.10(-4) M), Fe2+ (5.10(-5) M), EDTA (5.10(-5) M), and chemical enhancer lucigenin (10(-4) M) at pH 5.5 and 36 degrees C. Ascorbic acid exhibits up to 4-fold stronger antioxidant effect than uric acid. The constants of antioxidant inhibition in urine were measured at concentrations 10(-3) and 10(-4) M: for ascorbic acid, 5.92 +/- 0.04 and 24.05 +/- 1.82 micromol.sec(-1); for uric acid, 1.60 +/- 0.02 and 21.45 +/- 0.97 micromol.sec(-1), respectively. Three phases of CL kinetics of urine are well observed: spontaneous CL (0-10 sec), fast flash of CL (10-50 sec), and latent period (50-300 sec). The antioxidant efficiency of ascorbic and uric acids in the final stage of catabolic processes in the body is discussed.

[Mechanisms of the effects of Ca2+ ions on lipid peroxidation]. / Mekhanizmy deistviia ionov Ca2+ na protsess perekisnogo okisleniia lipidov.

Mechanisms underlying Ca2+ effects on lipid peroxidation (LPO) induced in liposomes (from egg yolk lecithin) and UFsomes (from linolenic acid, methyl linolenate) with the aid of O2- -system (Fe2+ + ascorbate) were studied. It was shown that stimulation of lipid peroxidation by low Ca2+ concentrations (10(-6)-10(-5) M) was due to its ability to release Fe2+-ions bound to negatively charged (phosphate, carboxylic) lipid groups (of licethin, linolenic acid), thus increasing the concentration of catalytically active Fe2+. The inhibitory effect of high Ca2+ concentrations was caused by its interaction with superoxide anion-radicals and was not observed in LPO-systems, independent of O2- generation (e. g. Fe2+ + cumol hydroperoxide).

Activation of lipid peroxidation: a mechanism triggering the autoimmune response.

Emotional-pain stress leads to accumulation of lipid peroxidation products in rat brain tissues and to an increase in the number of antibrain antibodies against water-soluble and membrane-bound antigens in rat blood. An injection of the free radical scavenger, 4-methyl-2.6-di-tert-butylphenol to experimental animals eliminates the accumulation of lipid peroxidation products "in vivo" and completely prevents the appearance of antibrain antibodies. The activation of lipid peroxidation under stress may be regarded as a possible cause of the brain-specific antibodies release into the blood flow.

Mechanisms of disassembly of a mixed function oxygenase system in liver endoplasmic reticulum: I. The role of peroxidation of membrane phospholipids.

It was demonstrated that endogenous lipid peroxidation (LPO) is an effective mechanism of disassembly of endoplasmic reticulum membranes and cytochrome P-450 (P-448) in the liver. The rate of cytochrome P-450 (P-448) degradation in vivo can be regulated by free radical scavengers. The constitutive forms of cytochrome P-450 (P-448) are less sensitive to LPO induced in vivo or in vitro than the inducible ones.

Mechanisms of disassembly of a mixed function oxygenase system in liver endoplasmic reticulum: II. The interrelation between lipid peroxidation and proteolytic degradation of cytochrome P-450.

The degradation of cytochrome P-450 as a result of proteolytic action of trypsin is a biphasic process. Lipid peroxidation (LPO) increases the rate of the fast phase of cytochrome P-450 degradation and its accessibility to protease. The efficiency of this process depends on the mode of LPO induction and decreases in the following order: NADPH----NADH----ascorbate-dependent LPO. The induction of the monooxygenase system increases the efficiency of proteolysis. LPO and proteolysis seem to be mutually enhancing processes which provide for a high efficiency of cytochrome P-450 degradation. LPO can be regarded as a triggering mechanism which makes various forms of cytochrome P-450 accessible to endogenous proteases.

Formation of inhibitors of lipid peroxidation during oxidative metabolism of hydrophobic xenobiotics catalyzed by mixed function oxygenases.

It was shown that benz (alpha) pyrene inhibits the NADPH-dependent lipid peroxidation (LPO) in rat liver microsomes in vitro. The degree of LPO inhibition is correlated with the accumulation of hydroxylated derivatives of benz (alpha) pyrene in the presence of NADPH. Benz (alpha) pyrene protects cytochrome P-450 against conversion into its inactive form, P-420, induced by LPO. Another inhibitor of the NADPH-dependent LPO in rat liver microsomes is chlorpromazine. Inhibition of LPO is due to the antioxidant effect of hydroxylated derivatives of chlorpromazine formed in the course of its metabolism by NADPH-dependent microsomal oxygenase. NADPH-dependent formation of hydroxylated metabolites of chlorpromazine, possessing antioxidant properties, was also estimated in brain cortex microsomes from rats and men. It is shown that chlorpromazine when preliminarily injected to rats, protects against LPO activation in brain tissue in vivo induced by exposure of the animals to hyperbaric oxygenation.

[Role of lipid peroxidation in damage to serotonin receptors and development of epileptiform seizures during hyperoxia]. / Rol' perekisnogo okisleniia lipidov v povrezhdenii retseptorov serotonina i vozniknovenii épileptoformnykh sudorog pri giperoksii.

Hyperoxia brought about substantial accumulation of primary and end products of lipid peroxidation (LPO) and a significant lowering of alpha-tocopherol content in rat brain tissues. Preinjection of animals with synthetic and natural antioxidants (4-methyl-2,6-ditretbutylphenol and alpha-tocopherol) prevented LPO activation and decreased the frequency of epileptiform seizures induced by hyperoxia. Administration of a mixture of unsaturated fatty acids led to an opposite effect. The changes in the properties of serotonin receptors were found to be dependent on the hyperoxia-induced LPO. These changes were marked by the reduced specific binding of serotonin with neuronal membranes of the rat brain cortex. The data obtained allowed the conclusion about the key role played by LPO activation in toxic action of hyperbaric activation on the brain.

[Accumulation of gaseous products of lipid peroxidation in the expired air of human subjects during hyperbaric oxygenation]. / Nakoplenie gazoobraznykh produktov perekisnogo okisleniia lipidov v vydykhaemom vozdukhe u liudei pri giperbaricheskoi oksigenatsii.

Hyperbaric oxygenation (1 atm. of pure oxygen, 60 min. exposure) resulted in a sharp increase of the endogenous lipoperoxidation level in humans which was evaluated by the pentane content in the exhaled air. That activation of endogenous lipid peroxidation was a short-term process: 2-3-fold increase of pentane content 10 min after exposure to hyperbaric oxygenation and levelling off to control values in 1 hour. It is recommended to use determination of endogenous lipid peroxidation by the pentane content in the exhaled air in order to find optimal regimens of hyperbaric oxygenation.

[Test-systems for biomonitoring based on membrane-bound enzyme complexes. III. An assessment of the genotoxic action of industrial effluents in the Ames test-system with metabolic activation by microsomal monooxygenases]. / Test-sistemy dlia biomonitoringa na osnove membranno-sviazannykh fermentnykh kompleksov. III. Otsenka genotokischeskogo deistviia promyshlennykh stokov v test-sisteme Eimsa s metabolicheskoi aktivatsiei mikrosomal'nymi monooksigenazami.

Using the Ames mutation test system II samples of the Baikal pulp and paper effluents selected at different dates have been investigated. In 9 cases the effluent samples possessed no mutagenic activity; some samples revealed frame shift mutations, i.e. a medium mutagenic effect. In the presence of a metabolic activation system from the livers of phenobarbital-induced rats the mutagenic activity was considerably reduced.

[Calcium and lipid peroxidation in the heart mitochondrial and microsomal membranes]. / Kal'tsii i perekisnoe okislenie lipidov v membranakh mitokhondrii i mikrosom serdtsa.

Effect of the lipid peroxidation (LP) on the Ca2+-transport and the effect of different Ca2+-concentrations on the LP activation were studied in microsomes and mitochondria of the heart. A slight accumulation of LP-products in the microsomal fraction results in a complete inhibition of the membrane calcium-transport activity. Preliminary administration of antioxidants (4-methyl 2,6-ditretbutylphenol and alpha-tocopherol) prevents both the accumulation of LP-products and damage of the Ca2+-transport system. Calcium at 10(-6) M to 5 X 10(-5) M concentrations stimulates LP and while being increased to 2 X 10(-3) M it inhibits LP. The data obtained evidence an interrelation between alterations of the Ca2+-concentrations and LP activation in cardiomyocytes.

Lipid peroxidation in mitochondrial membranes induced by enzymatic deamination of biogenic amines.

In the presence of Fe2+ and ascorbate lipid peroxidation in mitochondrial membranes is induced by incubation of membrane fragments devoid of catalase activity with amines which are the substrates of monoamine oxidases of the type B (2-phenylethylamine, benzylamine) or transformed monoamine oxidases of the type A (cadaverine). The highest stimulation of lipid peroxidation is observed in the samples containing both cadaverine and benzylamine. On the contrary, the substrate of the monoamine oxidases of the type A, serotonin, causes an antioxidative effect under these conditions. The necessary prerequisites for lipid peroxidation induction in mitochondria during their incubation with amines are i) the absence of catalase activity in the biomembranes and, ii) the presence of physiological concentrations of Fe2+. Physiological concentrations of ascorbate or pH shifts cause additional stimulation of lipid peroxidation.

[NADPH2 and organic hydroperoxide-dependent oxidation of adrenaline to adrenochromes in liver and brain microsomes]. / Zavisimoe ot NADFH2 i organicheskikh gidroperekisei okislenie adrenalina v adrenokhrom v mikrosomakh pecheni i mozga.

It was shown that oxidation of adrenaline to adrenochrome in microsomal membranes of the brain and liver in the presence of NADP . H2 or NAD . H2 is mainly accounted for by the formation of a superoxide anion radical. The formation of adrenochrome from adrenalin was found to depend on organic hydroperoxides (natural and synthetic). The organic hydroperoxide-dependent oxidation of adrenochrome involves singlet oxygen. In microsomal fractions of the liver the organic peroxide-dependent oxidation of adrenalin was catalyzed by cytochrome P-450.