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Sample records for antioxidant defense mechanisms

  1. Antioxidative defense

    Directory of Open Access Journals (Sweden)

    Stevanović Jelka

    2011-01-01

    Full Text Available Free radicals occur constantly during metabolism and take part in numerous physiological processes, such as: intra-cellular and inter-cellular signalization, gene expression, removal of damaged or senescent cells, and control of the tone of blood vessels. However, there is an increased quantity of free radicals in situations of so-called oxidative stress, when they cause serious damage to cellular membranes (peroxidation of their lipids, damage of membrane proteins, and similar, to interior cellular protein molecules, as well as DNA molecules and carbohydrates. This is precisely why the organism has developed numerous mechanisms for removing free radicals and/or preventing their production. Some of these are enzyme-related and include superoxide-dismutase, catalase, glutathione-peroxidase, and others. Other, non-enzyme mechanisms, imply antioxidative activities of vitamins E and C, provitamin A, coenzyme Q, reduced glutation, and others. Since free radicals can leave the cell that has produced them and become dispersed throughout the body, in addition to antioxidative defense that functions within cellular structures, antioxidant extra-cellular defense has also been developed. This is comprised by: transferrin, lactoferrin, haptoglobin, hemopexin, ceruloplasmin, albumins, extra-cellular isoform SOD, extracellular glutathione-peroxidase, glucose, bilirubin, urates, and many other molecules.

  2. Endurance Training and Glutathione-Dependent Antioxidant Defense Mechanism in Heart of the Diabetic Rats

    OpenAIRE

    Mustafa Atalay; Osmo Hanninen; Mustafa Gul

    2003-01-01

    Regular physical exercise beneficially influences cardiac antioxidant defenses in normal rats. The aim of this study was to test whether endurance training can strengthen glutathione-dependent antioxidant defense mechanism and decrease lipid peroxidation in heart of the streptozotocin-induced diabetic rats. Redox status of glutathione in blood of diabetic rats in response to training and acute exercise was also examined. Eight weeks of treadmill training increased the endurance in streptozoto...

  3. Reactive Oxygen Species, Lipid Peroxidation and Antioxidative Defense Mechanism

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    Hossam S. EL-BELTAGI

    2013-05-01

    Full Text Available Lipid peroxidation can be defined as the oxidative deterioration of lipids containing any number of carbon-carbon double bonds. Lipid peroxidation is a well-established mechanism of cellular injury in both plants and animals, and is used as an indicator of oxidative stress in cells and tissues. Lipid peroxides are unstable and decompose to form a complex series of compounds including reactive carbonyl compounds. The oxidation of linoleates and cholesterol is discussed in some detail. Analytical methods for studying lipid peroxidation were mentioned. Various kinds of antioxidants with different functions inhibit lipid peroxidation and the deleterious effects caused by the lipid peroxidation products.

  4. ENDURANCE TRAINING AND GLUTATHIONE-DEPENDENT ANTIOXIDANT DEFENSE MECHANISM IN HEART OF THE DIABETIC RATS

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    Mustafa Atalay

    2003-06-01

    Full Text Available Regular physical exercise beneficially influences cardiac antioxidant defenses in normal rats. The aim of this study was to test whether endurance training can strengthen glutathione-dependent antioxidant defense mechanism and decrease lipid peroxidation in heart of the streptozotocin-induced diabetic rats. Redox status of glutathione in blood of diabetic rats in response to training and acute exercise was also examined. Eight weeks of treadmill training increased the endurance in streptozotocin-induced diabetic rats. It did not affect glutathione level in heart tissue at rest and also after exercise. On the other hand, endurance training decreased glutathione peroxidase activity in heart, while glutathione reductase and glutathione S-transferase activities were not affected either by acute exhaustive exercise or endurance training. Reduced and oxidized glutathione levels in blood were not affected by either training or acute exercise. Conjugated dienes levels in heart tissue were increased by acute exhaustive exercise and also 8 weeks treadmill training. Longer duration of exhaustion in trained group may have contributed to the increased conjugated dienes levels in heart after acute exercise. Our results suggest that endurance type exercise may make heart more susceptible to oxidative stress. Therefore it may be wise to combine aerobic exercise with insulin treatment to prevent its adverse effects on antioxidant defense in heart in patients with diabetes mellitus

  5. Preventive role of lens antioxidant defense mechanism against riboflavin-mediated sunlight damaging of lens crystallins.

    Science.gov (United States)

    Anbaraki, Afrooz; Khoshaman, Kazem; Ghasemi, Younes; Yousefi, Reza

    2016-10-01

    The main components of sunlight reaching the eye lens are UVA and visible light exerting their photo-damaging effects indirectly by the aid of endogenous photosensitizer molecules such as riboflavin (RF). In this study, lens proteins solutions were incubated with RF and exposed to the sunlight. Then, gel mobility shift analysis and different spectroscopic assessments were applied to examine the structural damaging effects of solar radiation on these proteins. Exposure of lens proteins to direct sunlight, in the presence of RF, leads to marked structural crosslinking, oligomerization and proteolytic instability. These structural damages were also accompanied with reduction in the emission fluorescence of Trp and Tyr and appearance of a new absorption peak between 300 and 400nm which can be related to formation of new chromophores. Also, photo-oxidation of lens crystallins increases their oligomeric size distribution as examined by dynamic light scattering analysis. The above mentioned structural insults, as potential sources of sunlight-induced senile cataract and blindness, were significantly attenuated in the presence of ascorbic acid and glutathione which are two important components of lens antioxidant defense system. Therefore, the powerful antioxidant defense mechanism of eye lens is an important barrier against molecular photo-damaging effects of solar radiations during the life span. PMID:27316765

  6. Lead tolerance mechanism in Conyza canadensis: subcellular distribution, ultrastructure, antioxidative defense system, and phytochelatins.

    Science.gov (United States)

    Li, Ying; Zhou, Chuifan; Huang, Meiying; Luo, Jiewen; Hou, Xiaolong; Wu, Pengfei; Ma, Xiangqing

    2016-03-01

    We used hydroponic experiments to examine the effects of different concentrations of lead (Pb) on the performance of the Pb-tolerable plant Conyza canadensis. In these experiments, most of the Pb was accumulated in the roots; there was very little Pb accumulated in stems and leaves. C. canadensis is able to take up significant amounts of Pb whilst greatly restricting its transportation to specific parts of the aboveground biomass. High Pb concentrations inhibited plant growth, increased membrane permeability, elevated antioxidant enzyme activity in roots, and caused a significant increase in root H2O2 and malondialdehyde content. Analysis of Pb content at the subcellular level showed that most Pb was associated with the cell wall fraction, followed by the nucleus-rich fraction, and with a minority present in the mitochondrial and soluble fractions. Furthermore, transmission electron microscopy and energy dispersive X-ray analysis of root cells revealed that the cell wall and intercellular space in C. canadensis roots are the main locations of Pb accumulation. Additionally, high Pb concentrations adversely affected the cellular structure of C. canadensis roots. The increased enzyme activity suggests that the antioxidant system may play an important role in eliminating or alleviating Pb toxicity in C. canadensis roots. However, the levels of non-protein sulfhydryl compounds, glutathione, and phytochelatin did not significantly change in either the roots or leaves under Pb-contaminated treatments. Our results provide strong evidence that cell walls restrict Pb uptake into the root and act as an important barrier protecting root cells, while demonstrating that antioxidant enzyme levels are correlated with Pb exposure. These findings demonstrate the roles played by these detoxification mechanisms in supporting Pb tolerance in C. canadensis. PMID:26733305

  7. SOME ASPECTS OF ANTIOXIDANT DEFENSE MECHANISMS IN WOOD SPECIES EXPOSED TO ANTHROPIC POLLUTION IN SUCEAVA COUNTY

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    Marius Viorel Oniciuc

    2013-02-01

    Full Text Available Increased production of reactive oxygen species in plant tissues caused by unfavorableenvironmental conditions is early response to different stresses and may provide cells with resistance against theirformation. The subject of this paper is determination of catalase and peroxidase levels, components of the antioxidantdefense mechanism, in various types of woody plants in order to study the effect of pollution by sulphur and copperexploitation in mining areas on the antioxidant enzymes activity in the leaf material taken from different Gymnospermspecies as Picea abies L.Karst., Larix decidua Mill. and Angyosperms like Salix ssp alba L., Populus tremula, Betulaverrucosa Ehrh. şi Fagus sylvatica L. For this purpose, the measurement of catalase activity was performed using theSinha method (Artenie Vl. et al., 2008, the determination of peroxidase level was carried out on the basis of ortho-dianisidine method (Cojocaru D.C., 2009 and the determination of soluble proteins on Bradford method (Cojocaru etal.,2009. The results obtained lead to the conclusion that both catalase and peroxidase are effective biomarkers ofpollution with sulfur, copper ores and barite but especially the acclimatization of species studied in conditions of chronicexposure.

  8. CADMIUM AND NICKEL COMBINED EFFECT ON ASCORBATE-DEPENDENT MECHANISM OF ANTIOXIDATIVE DEFENSE SYSTEM OF PEA

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    Artiushenko Tetiana A.

    2014-04-01

    Full Text Available The dynamics of changes in the content of different forms of ascorbic acid and ascorbate peroxidase activity in pea vegetative organs as components of antioxidant protection for the cadmium and nickel combined effect is investigated. It was established, that in assimilation tissues of pea the seedlings amount of ascorbic acid reduced form was more higher compared to the roots by 9 times. Using of toxicants in high concentration in the first hour of exposure, probably resulted a significant activation of the ascorbic acid synthesis in pea roots, as indicated by the increase in its quantity by 44%. In the early stages of ontogeny with increasing duration of cadmium and nickel compounds stress action to 7 hours in pea roots showed a trend towards increase in ascorbic acid at 23-68% in all the variants of the experiments. The aforementioned was accompanied by significant increase of the level of dehydroascorbate acid and product of ascorbate irreversible oxidation – 2,3-diketogulonic acid. By contrast in the leaves under the toxicants influence at low concentrations is not the case of ascorbate amount changes. However we registered the increasing of dehydroascorbate acid amount by almost 20% compared to control, which may indicate the induction of the antioxidant synthesis. In other cases, there was a tendency to decrease in the ascorbic acid content. The study content of ascorbic acid various metabolites in the pea roots to 12 hours stressful action of cadmium and nickel compounds showed violations in pro-/antioxidant balance. This was confirmed by a decrease content of reduced ascorbate regards control level. After a 12-hour of stress the ascorbate amount decreased, whereas dehydroascorbate and 2,3-diketogulonic acids continued to increase. Existing experimental data allows conclude that the 12 hour exposure of pea plants in a medium with a low concentration of the cadmium and nickel compounds the ascorbic acid content in the leaves increased

  9. Understanding Defense Mechanisms.

    Science.gov (United States)

    Cramer, Phebe

    2015-12-01

    Understanding defense mechanisms is an important part of psychotherapy. In this article, we trace the history of the concept of defense, from its origin with Freud to current views. The issue of defense as an unconscious mechanism is examined. The question of whether defenses are pathological, as well as their relation to pathology, is discussed. The effect of psychotherapy on the use of defenses, and their relation to a therapeutic alliance is explored. A series of empirical research studies that demonstrate the functioning of defense mechanisms and that support the theory is presented. Research also shows that as part of normal development, different defenses emerge at different developmental periods, and that gender differences in defense use occur. PMID:26583439

  10. Defense Mechanisms: A Bibliography.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    This bibliography includes studies of defense mechanisms, in general, and studies of multiple mechanisms. Defense mechanisms, briefly and simply defined, are the unconscious ego defendants against unpleasure, threat, or anxiety. Sigmund Freud deserves the clinical credit for studying many mechanisms and introducing them in professional literature.…

  11. Ornithine and Homocitrulline Impair Mitochondrial Function, Decrease Antioxidant Defenses and Induce Cell Death in Menadione-Stressed Rat Cortical Astrocytes: Potential Mechanisms of Neurological Dysfunction in HHH Syndrome.

    Science.gov (United States)

    Zanatta, Ângela; Rodrigues, Marília Danyelle Nunes; Amaral, Alexandre Umpierrez; Souza, Débora Guerini; Quincozes-Santos, André; Wajner, Moacir

    2016-09-01

    Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is caused by deficiency of ornithine translocase leading to predominant tissue accumulation and high urinary excretion of ornithine (Orn), homocitrulline (Hcit) and ammonia. Although affected patients commonly present neurological dysfunction manifested by cognitive deficit, spastic paraplegia, pyramidal and extrapyramidal signs, stroke-like episodes, hypotonia and ataxia, its pathogenesis is still poorly known. Although astrocytes are necessary for neuronal protection. Therefore, in the present study we investigated the effects of Orn and Hcit on cell viability (propidium iodide incorporation), mitochondrial function (thiazolyl blue tetrazolium bromide-MTT-reduction and mitochondrial membrane potential-ΔΨm), antioxidant defenses (GSH) and pro-inflammatory response (NFkB, IL-1β, IL-6 and TNF-α) in unstimulated and menadione-stressed cortical astrocytes that were previously shown to be susceptible to damage by neurotoxins. We first observed that Orn decreased MTT reduction, whereas both amino acids decreased GSH levels, without altering cell viability and the pro-inflammatory factors in unstimulated astrocytes. Furthermore, Orn and Hcit decreased cell viability and ΔΨm in menadione-treated astrocytes. The present data indicate that the major compounds accumulating in HHH syndrome impair mitochondrial function and reduce cell viability and the antioxidant defenses in cultured astrocytes especially when stressed by menadione. It is presumed that these mechanisms may be involved in the neuropathology of this disease. PMID:27161368

  12. Zinc cystein as an enhancer to natural antioxidant defense mechanism (s) in whole body gamma irradiated rats

    International Nuclear Information System (INIS)

    Malonaldehyde (MDA), reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity in liver and blood, were measured in whole body gamma irradiated rats with a dose of 6.5 Gy before and after administration of zinc cystein. Zinc cystein (Zn/cyst) was administrated intraperitoneally at a concentration of 30 mg/kg, b.w. 30 min pre-irradiation and measurements were done at 24 and 72 hr after irradiation. These results were compared with non-irradiated. These results were compared with non-irradiated, non Zn/cyst treated group (control group). After irradiation, the activity of SOD and the level of GSH in both liver and blood were decreased, while in Zn/cyst protected groups this decrease was less but did not reach to that of control group level till the end of the experimental period. On the other hand, MDA markedly increased after irradiation. Nevertheless, and in protected group with Z0/cyst reveled less increase. It can be concluded that pre-treatment with Zn/cyst protects rats against sublethal effect of radiation, by improving the natural antioxidant mechanism (s)

  13. Defense Mechanisms in Group Counseling.

    Science.gov (United States)

    Clark, Arthur J.

    1992-01-01

    Presents considerations and strategies for conceptualizing, recognizing, and modifying defense mechanisms through the group counseling process. Provides awareness of defense mechanisms in planning for and implementation of group counseling, describes interaction patterns for identifying defenses among group participants, and clarifies modification…

  14. Response of Antioxidant Substances and Enzymes Activities as a Defense Mechanism Against Root-Knot Nematode Infection

    OpenAIRE

    Hossam Saad EL-BELTAGI; Ahmed A FARAHAT; Alsayed A. ALSAYED; Nomer M. MAHFOUD

    2012-01-01

    The organic amendments, composts (1, 2, 3), neem and poultry as well as inorganic fertilizers (NPK compound and commercial, Athree®) and the nematicide nemacur 10 G applied singly were effective in reducing M. incognita number of galls, nematode reproductionand fecundity. The effectiveness seemed to be material origin dependent. Neem, compost 1, 3 (5 g/pot) gave the best results. Yet, achievedresults were less than those of nemacur 10% G. The antioxidant substances content and enzymes activit...

  15. Antioxidant defense system in hibernating mammals

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    Antonova Ekaterina Petrovna

    2015-06-01

    Full Text Available Hibernation is one of the most striking examples of mammals’ phenotypic flexibility, allowing them to survive at low temperatures and in the conditions of insufficient food and water. During the torpor there is a decrease in both body temperature and metabolic rate that is accompanied by slowing respiration, significant drop of oxygen consumption as well as by the reduction of cerebral blood circulation and heart rate. In spite of a number of physiological adaptations to hibernation, the arousal from torpor is accompanied by the oxidative stress caused by the enormous rise of oxygen consumption. In these conditions, the antioxidant defense system which provides harmless transfer from torpor to arousal and vice versa, i.e., without any tissues’ oxidative damage, becomes especially important. Up to date, it is not fully elucidated how the antioxidant system acts during the periods of hibernation, but it deserves careful attention. In the review the information about the use of different strategies of antioxidant protection during hibernation in small mammals was collected

  16. Teaching Psychological Defense Mechanisms: "The Defense Mechanisms Game."

    Science.gov (United States)

    Waugh, Charles G.

    1980-01-01

    Presents the rules for an educational game in which students reinforce psychology lecture material by creating and dramatizing defense mechanisms such as reaction formation, displacement, and fantasy. Provides definitions and examples of the various defense mechanisms that can be portrayed. (JP)

  17. Response of Antioxidant Substances and Enzymes Activities as a Defense Mechanism Against Root-Knot Nematode Infection

    Directory of Open Access Journals (Sweden)

    Hossam Saad EL-BELTAGI

    2012-05-01

    Full Text Available The organic amendments, composts (1, 2, 3, neem and poultry as well as inorganic fertilizers (NPK compound and commercial, Athree® and the nematicide nemacur 10 G applied singly were effective in reducing M. incognita number of galls, nematode reproductionand fecundity. The effectiveness seemed to be material origin dependent. Neem, compost 1, 3 (5 g/pot gave the best results. Yet, achievedresults were less than those of nemacur 10% G. The antioxidant substances content and enzymes activities due to nematode infectionand application of organic and inorganic fertilizers pointed to significant increase of lipid peroxidation and hydrogen peroxide as aresult of nematode infection and nemacur treatment. While all organic and inorganic fertilizers reduced such materials with significantdifferences among treatments. Likewise, nematode infection resulted in slight but significant increase in glutathione and ascorbic acidin tomato shoots and roots. All treatments increased antioxidant substances comparing to healthy and infected plants. Glutathione-Stransferaseactivity highly increased in infected roots but the lowest activities were achieved by organic fertilizers. Nematode infectionand nemacur treatment increased slightly phenylalaine ammonia lyase activity but enormous increase was observed in shoots and rootsof treated plants with organic fertilizers followed by NPK treatments.

  18. Control Processes and Defense Mechanisms

    OpenAIRE

    HOROWITZ, MARDI; Cooper, Steven; FRIDHANDLER, BRAM; Perry, J. Christopher; Bond, Michael; VAILLANT, GEORGE

    1992-01-01

    Defense-mechanism theory and control-process theory are related psychodynamic approaches to explaining and classifying how people ward off emotional upsets. Although both theories explain defensive maneuvers in the same motivational terms, each defines categories different1y. Classic categories define defense mechanisms at a relatively macroscopic level, whereas control-process theory aims at relatively microgenetic analysis of how cognitive maneuvers—involving what is th...

  19. Assertion and Defense Mechanism Preference.

    Science.gov (United States)

    Massong, Stefan R.; And Others

    1982-01-01

    Investigated whether assertive and nonassertive individuals differ in defense mechanisms they most typically rely on when confronted with interpersonal stress and conflict. Results indicated assertive males and females both endorsed the most adaptive defense mechanism cluster, whereas nonassertive males and females endorsed more primitive defense…

  20. Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen

    Energy Technology Data Exchange (ETDEWEB)

    Phung, Thu-Ha; Jung, Sunyo, E-mail: sjung@knu.ac.kr

    2015-04-03

    This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, F{sub v}/F{sub m}, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H{sub 2}O{sub 2} production and greater increases in H{sub 2}O{sub 2}-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redox state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage. - Highlights: • We employ two different types of photodynamic stress, white and brown necrosis. • We examine molecular mechanisms of antioxidative and detoxification systems. • ALA and OF develop differential actions of antioxidant and detoxification systems. • Coordinated mechanism of antioxidants and detoxification works against toxic ROS. • Detoxification system plays critical roles in protection against photodynamic stress.

  1. Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen

    International Nuclear Information System (INIS)

    This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, Fv/Fm, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H2O2 production and greater increases in H2O2-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redox state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage. - Highlights: • We employ two different types of photodynamic stress, white and brown necrosis. • We examine molecular mechanisms of antioxidative and detoxification systems. • ALA and OF develop differential actions of antioxidant and detoxification systems. • Coordinated mechanism of antioxidants and detoxification works against toxic ROS. • Detoxification system plays critical roles in protection against photodynamic stress

  2. Pineal Proteins Upregulate Specific Antioxidant Defense Systems in the Brain

    OpenAIRE

    Vijay K. Bharti; Srivastava, R. S.

    2009-01-01

    The neuroendocrine functions of the pineal affect a wide variety of glandular and nervous system processes. Beside melatonin (MEL), the pineal gland secretes and expresses certain proteins essential for various physiological functions. It has been suggested that the pineal gland may also have an antioxidant role due to secretory product other than MEL. Therefore, the present study was designed to study the effect of buffalo (Bubalus bubalis) pineal proteins (PP) on the antioxidant defense sys...

  3. A Hierarchal System of Defense Mechanisms.

    Science.gov (United States)

    Lee, Gerald

    1979-01-01

    Constructs a hierarchy of defense mechanisms through the addition of the concepts of secondary and tertiary defenses to the already existing psychoanalytic defenses and increases the explanatory power of the concept of defense. Research generated from this theoretical model is presented. (Author/BEF)

  4. Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen.

    Science.gov (United States)

    Phung, Thu-Ha; Jung, Sunyo

    2015-04-01

    This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, Fv/Fm, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H2O2 production and greater increases in H2O2-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redox state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage. PMID:25735982

  5. Markers of Antioxidant Defense in Patients with Type 2 Diabetes

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    K. Gawlik

    2016-01-01

    Full Text Available Aims. Diabetes is considered a state of increased oxidative stress. This study evaluates blood concentrations of selected markers of antioxidant defense in patients with type 2 diabetes. Methods. The study included 80 type 2 diabetes patients and 79 apparently healthy controls. Measured markers included ferric reducing ability of plasma (FRAP, reduced glutathione (GSH, glutathione peroxidase (GPx, glutathione reductase (GR, γ-glutamyltransferase (GGT and uric acid serum, and plasma and/or hemolysate levels. Results. FRAP, uric acid, CRP, and GGT levels were significantly higher in patients with diabetes. Plasma and hemolysate GR was significantly higher whereas GPx activity was significantly lower in patients with diabetes. There were no significant differences in antioxidant defense markers between patients with and without chronic diabetes complications. Fasting serum glucose correlated with plasma GPx, plasma and hemolysate GR, FRAP, and serum GGT, and HbA1c correlated with serum GGT. Only FRAP and serum uric acid were significantly higher in obese (BMI>30 kg/m2 patients with diabetes than in nonobese patients. Conclusions. Some components of antioxidant defense such as GR, uric acid, and GGT are increased in patients with type 2 diabetes. However, the whole system cannot compensate for an enhanced production of ROS as reflected by the trend toward decreased erythrocytes GSH.

  6. Pineal Proteins Upregulate Specific Antioxidant Defense Systems in the Brain

    Directory of Open Access Journals (Sweden)

    Vijay K. Bharti

    2009-01-01

    Full Text Available The neuroendocrine functions of the pineal affect a wide variety of glandular and nervous system processes. Beside melatonin (MEL, the pineal gland secretes and expresses certain proteins essential for various physiological functions. It has been suggested that the pineal gland may also have an antioxidant role due to secretory product other than MEL. Therefore, the present study was designed to study the effect of buffalo (Bubalus bubalis pineal proteins (PP on the antioxidant defense system in the brain of female rats. The twenty-four rats were taken in present study and were divided into four groups: control (0 day, control (28 day, vehicle control and buffalo PP. The PP was injected 100 µg/kg BW intraperitoneal (i.p. daily for 28 days. The activities of superoxide dismutase (SOD, glutathione peroxidase (GPx, catalase (CAT, glutathione reductase (GR and reduced glutathione (GSH concentration and the levels of lipid peroxidation (LPO in the brain tissue were measured to assess the antioxidant systems. These enzymes protect from adverse effects of free radicals and help in amelioration of oxidative stress. Buffalo pineal proteins administration did not cause any effect on brain LPO, whereas GPx, GR and GSH were significantly (p < 0.05 decreased. However, SOD and CAT activities were increased to significant levels than the control in PP treated rats. Our study herein suggested that buffalo (Bubalus bubalis pineal proteins upregulates specific antioxidant defense systems and can be useful in control of various oxidative stress-induced neuronal diseases.

  7. Mechanisms of plant defense against insect herbivores

    OpenAIRE

    War, Abdul Rashid; Paulraj, Michael Gabriel; Ahmad, Tariq; BUHROO, Abdul Ahad; Hussain, Barkat; Ignacimuthu, Savarimuthu; Sharma, Hari Chand

    2012-01-01

    Plants respond to herbivory through various morphological, biochemicals, and molecular mechanisms to counter/offset the effects of herbivore attack. The biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic, and are mediated both by direct and indirect defenses. The defensive compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. In addition, plants also release volatile organic c...

  8. The Defense Mechanisms of Coronary Patients.

    Science.gov (United States)

    Peglar, Marian; Borgen, Fred H.

    1984-01-01

    Tested 73 male inpatients with coronary heart disease on the Defense Mechanisms Inventory, State-Trait Anxiety Inventory, and a perception of health measure. Subjects were followed for five years. Principalization was discovered to be the most successful and projection the least successful defense. (JAC)

  9. Protecting the Self: Defense Mechanisms in Action

    Science.gov (United States)

    Cramer, Phebe

    2006-01-01

    Integrating theory, research, and practical applications, this book provides a comprehensive examination of defense mechanisms and their role in both normal development and psychopathology. The author describes how children and adults mobilize specific kinds of defenses to maintain their psychological equilibrium and preserve self-esteem,…

  10. Whole body exposure to low-dose γ-radiation enhances the antioxidant defense system

    International Nuclear Information System (INIS)

    It is believed that the extent of cellular damage by low- radiation dose is proportional to the effects observed at high radiation dose as per the Linear-No-Threshold (LNT) hypothesis. However, this notion may not be true at low-dose radiation exposure in the living system. Recent evidence suggest that the living organisms do not respond to ionizing radiations in a linear manner in the low dose range 0.01-0.5Gy and rather restore the homeostasis both in vivo and in vitro by normal physiological mechanisms such as cellular and DNA repair processes, immune reactions, antioxidant defense, adaptive responses, activation of immune functions, stimulation of growth etc. In this study, we have attempted to find the critical radiation dose range and the post irradiation period during which the antioxidant defense systems in the lungs, liver and kidneys remain stimulated in these organs after whole body exposure of the animals to low-dose radiation

  11. The mtDNA NARP mutation activates the actin-Nrf2 signaling of antioxidant defenses

    International Nuclear Information System (INIS)

    An efficient handling of superoxides by antioxidant defenses is a crucial issue for cells with respiratory chain deficient mitochondria. We used human cultured skin fibroblasts to delineate the mechanism controlling the expression of antioxidant defenses in the case of a severe ATPase deficiency resulting from an 8993T>G mutation in the mitochondrial ATPase6 gene. We observed the nuclear translocation of the transcription factor Nrf2 associated with thinning of the actin stress fibers. The mobilization of the Nrf2 signaling pathway could be mimicked by a chemical blockade of the ATPase with a specific inhibitor, oligomycin. Interestingly enough, Nrf2 nuclear translocation was not observed in the case of a severe cytochrome oxidase deficiency, indicating that studying the status of this signaling pathway could throw some light on the importance of the oxidative insult associated with different respiratory chain defects

  12. Antioxidant defenses predict long-term survival in a passerine bird.

    Directory of Open Access Journals (Sweden)

    Nicola Saino

    Full Text Available BACKGROUND: Normal and pathological processes entail the production of oxidative substances that can damage biological molecules and harm physiological functions. Organisms have evolved complex mechanisms of antioxidant defense, and any imbalance between oxidative challenge and antioxidant protection can depress fitness components and accelerate senescence. While the role of oxidative stress in pathogenesis and aging has been studied intensively in humans and model animal species under laboratory conditions, there is a dearth of knowledge on its role in shaping life-histories of animals under natural selection regimes. Yet, given the pervasive nature and likely fitness consequences of oxidative damage, it can be expected that the need to secure efficient antioxidant protection is powerful in molding the evolutionary ecology of animals. Here, we test whether overall antioxidant defense varies with age and predicts long-term survival, using a wild population of a migratory passerine bird, the barn swallow (Hirundo rustica, as a model. METHODOLOGY/PRINCIPAL FINDINGS: Plasma antioxidant capacity (AOC of breeding individuals was measured using standard protocols and annual survival was monitored over five years (2006-2010 on a large sample of selection episodes. AOC did not covary with age in longitudinal analyses after discounting the effect of selection. AOC positively predicted annual survival independently of sex. Individuals were highly consistent in their relative levels of AOC, implying the existence of additive genetic variance and/or environmental (including early maternal components consistently acting through their lives. CONCLUSIONS: Using longitudinal data we showed that high levels of antioxidant protection positively predict long-term survival in a wild animal population. Present results are therefore novel in disclosing a role for antioxidant protection in determining survival under natural conditions, strongly demanding for more

  13. The antioxidant defense system of Varroa destructor mites facilitates the infestation of Apis mellifera

    Directory of Open Access Journals (Sweden)

    Dmochowska-Ślęzak Kamila

    2016-06-01

    Full Text Available Varroa destructor is a parasitic mite of the Western honey bee. The activity of five antioxidant enzymes of V. destructor were analysed. Glutathione content and total antioxidant status was also evaluated. Our results suggest that antioxidant enzymes constitute the main line of defense against ROS in V. destructor, whereas low-molecular-weight antioxidants play a limited role in the antioxidant system of mites.

  14. Deciphering Staphylococcus sciuri SAT-17 Mediated Anti-oxidative Defense Mechanisms and Growth Modulations in Salt Stressed Maize (Zea mays L.).

    Science.gov (United States)

    Akram, Muhammad S; Shahid, Muhammad; Tariq, Mohsin; Azeem, Muhammad; Javed, Muhammad T; Saleem, Seemab; Riaz, Saba

    2016-01-01

    Soil salinity severely affects plant nutrient use efficiency and is a worldwide constraint for sustainable crop production. Plant growth-promoting rhizobacteria, with inherent salinity tolerance, are able to enhance plant growth and productivity by inducing modulations in various metabolic pathways. In the present study, we reported the isolation and characterization of a salt-tolerant rhizobacterium from Kallar grass [Leptochloa fusca (L.) Kunth]. Sequencing of the 16S rRNA gene revealed its lineage to Staphylococcus sciuri and it was named as SAT-17. The strain exhibited substantial potential of phosphate solubilization as well as indole-3-acetic acid production (up to 2 M NaCl) and 1-aminocyclopropane-1-carboxylic acid deaminase activity (up to 1.5 M NaCl). Inoculation of a rifampicin-resistant derivative of the SAT-17 with maize, in the absence of salt stress, induced a significant increase in plant biomass together with decreased reactive oxygen species and increased activity of cellular antioxidant enzymes. The derivative strain also significantly accumulated nutrients in roots and shoots, and enhanced chlorophyll and protein contents in comparison with non-inoculated plants. Similar positive effects were observed in the presence of salt stress, although the effect was more prominent at 75 mM in comparison to higher NaCl level (150 mM). The strain survived in the rhizosphere up to 30 days at an optimal population density (ca. 1 × 10(6) CFU mL(-1)). It was concluded that S. sciuri strain SAT-17 alleviated maize plants from salt-induced cellular oxidative damage and enhanced growth. Further field experiments should be conducted, considering SAT-17 as a potential bio-fertilizer, to draw parallels between PGPR inoculation, elemental mobility patterns, crop growth and productivity in salt-stressed semi-arid and arid regions. PMID:27375588

  15. Inorganic Arsenic Induces NRF2-Regulated Antioxidant Defenses in Both Cerebral Cortex and Hippocampus in Vivo.

    Science.gov (United States)

    Zhang, Yang; Duan, Xiaoxu; Li, Jinlong; Zhao, Shuo; Li, Wei; Zhao, Lu; Li, Wei; Nie, Huifang; Sun, Guifang; Li, Bing

    2016-08-01

    Inorganic arsenic is reported to induce the reactive oxygen species-mediated oxidative stress, which is supposed to be one of the main mechanisms of arsenic-related neurological diseases. Nuclear factor erythroid 2-related factor 2 (NRF2), a master regulator of antioxidant defense systems, up-regulates the expression of target genes to fight against oxidative damages caused by harmful substances, including metals. In the present study, mice were used as a model to investigate the oxidative stress levels and the expressions of NRF2-regulated antioxidant substances in both cerebral cortex and hippocampus with 5, 10 and 20 mg/kg NaAsO2 exposure intra-gastrically. Our results showed that acute NaAsO2 treatment resulted in decreased total anti-oxidative capacity (T-AOC) and increased maleic dialdehyde production in the nervous system. We also detected rapidly elevation of NRF2 protein levels by enhancement of Nrf2 transcription, especially at 20 mg/kg NaAsO2 exposure group. In the meantime, mRNA and protein levels of Nrf2 encoding antioxidant enzymes heme oxygenase-1 (HO-1), NAD(P)H: quinine oxidoreductase 1 (NQO1) and glutathione S-transferase (GST) were consistently elevated time- and dose-dependently both in the cerebral cortex and hippocampus. Taken together, the presence study demonstrated the activation of NRF2 pathway, an early antioxidant defensive response, in both cerebral cortex and hippocampus upon inorganic arsenic (iAs) exposure in vivo. A better knowledge on the roles of NRF2 pathway in maintaining cellular redox homeostasis would be helpful for the strategies on improvement of neurotoxicity related to this metalloid. PMID:27165637

  16. EFFECTS OF PROLONGED EXERCISE ON OXIDATIVE STRESS AND ANTIOXIDANT DEFENSE IN ENDURANCE HORSE

    Directory of Open Access Journals (Sweden)

    Susanna Kinnunen

    2005-12-01

    Full Text Available Increased oxidative stress during prolonged endurance exercise may end up with muscle damage, fatigue and decreased physical performance. We have recently shown that acute exercise at moderate intensity induced lipid peroxidation, protein oxidation and oxygen radical absorbance capacity (ORAC in trained trotters. The aim of this study was to measure the changes in oxidative stress and antioxidant defense following an 80-km ride in the blood of endurance horses. Blood samples were collected before and immediately after the ride. Unlike to our previous studies performed on trotters, in endurance horses there were no measurable changes in antioxidants or oxidative stress marker lipid hydroperoxides (LPO after prolonged exercise. ORAC, vitamin E and lipid hydroperoxide (LPO concentration or glutathione related enzyme activities were not altered due to the 80-km ride. However, the base line levels of oxidative stress marker were higher in endurance horses compared to trotters. A positive correlation between the pre-ride LPO concentration and erythrocyte glutathione peroxidase (GPx activity after the ride was observed, which may indicate a protective response of glutathione peroxidase against exercise-induced oxidative stress. Our results suggest that endurance horses have higher oxidative stress levels compared to trotters and a single 80-km ride probably did not suffice to induce oxidative stress and to activate antioxidant defense mechanisms.

  17. Defense mechanisms of the respiratory membrane.

    Science.gov (United States)

    Green, G M; Jakab, G J; Low, R B; Davis, G S

    1977-03-01

    The success or failure of pulmonary defense mechanisms largely determines the appearance of clinical lung disease. The lung is protected by interlucking systems of nonspecific and specific defenses. Inhaled substrances can be isolated by mechanical barriers or can be physically removed from the lung either by transport up the bronchial mucociliary escalator or by transport through interstitial and lymphatic channels leading to lymph nodes. Substances can be locally detoxified within the lung by interaction with secretory proteins, such as antibodies, or by neutralization and dissolution within phagocytic cells. The pulmonary alveolar macrophage is the central figure in the protection of the respiratory membrane, operating in all 3 of the nonspecific modes of defense and augmented by specific immunologic mechanisms as well. Alterations in macrophage function and physiology may be crucial in determining the effectiveness of pulmonary defense. Recent advances in the cell biology of the alveolar macrophage have led to a greater understanding of its complex funcition. The multiple origins of macrophages from local and circulating cell pools and the variability in their fate and lifespan reflect the multi-faceted role of this cell type. The importance of the interactions between macrophages, orther lung cells, and other defense mechanisms has become increasingly clear. As well as functioning as resident defender of the alveolus, the macrophage is an important effector of the pulmonary immune response and plays a key role in the pathogenesis of a wide variety of inflammatory, destructive, and fibrotic lung diseases. Humoral and cell-mediated immune responses amplify and direct lung defenses against infection and may also participate in protection against other agents. Immunoglobulin A and G, microbial neutralizing and opsonizing anti-bodies, and macrophage-stimulating T lymphocytes are the major immunospecific forms of lung defense. Infectious agents, cigarette smoke, air

  18. The Identification and Modification of Defense Mechanisms in Counseling.

    Science.gov (United States)

    Clark, Arthur J.

    1991-01-01

    Suggests considerations and strategies for identifying and modifying a client's defense mechanisms in counseling. Provides definitions of individual defenses and indicators for identifying the mechanisms. Literature review focuses on counseling implications of defenses. Process of defense mechanism modification is illustrated through case example.…

  19. DEFENSE MECHANISMS FOR COMPUTER-BASED INFORMATION SYSTEMS

    OpenAIRE

    Majid Alshammari; Christian Bach

    2013-01-01

    Nowadays, corporations and a government agencies relay on computer-based information system to manage their information, this information may be classified, so it will be dangerous if it is disclosed by unauthorized persons. Therefore, there is urgent need for defense. In this research, defense has been categorized into four mechanisms technical defense, operation defense, management defense, and physical defense based on the logic of computer and network security. Also, each mechanism has be...

  20. Defense Mechanisms: Discussions and Bibliographies; General or Multiple, and Specific.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    This publication considers some Freudian ego mechanisms. The first discussion and bibliography concerns defense mechanisms, in general or in multiple; after which, the discussions and bibliographies concern specific defense mechanisms: denial; displacement, substitution, sublimation; fixation; identification, introjection, incorporation,…

  1. Oxidative stress: molecular perception and transduction of signals triggering antioxidant gene defenses

    Directory of Open Access Journals (Sweden)

    J.G. Scandalios

    2005-07-01

    Full Text Available Molecular oxygen (O2 is the premier biological electron acceptor that serves vital roles in fundamental cellular functions. However, with the beneficial properties of O2 comes the inadvertent formation of reactive oxygen species (ROS such as superoxide (O2·-, hydrogen peroxide, and hydroxyl radical (OH·. If unabated, ROS pose a serious threat to or cause the death of aerobic cells. To minimize the damaging effects of ROS, aerobic organisms evolved non-enzymatic and enzymatic antioxidant defenses. The latter include catalases, peroxidases, superoxide dismutases, and glutathione S-transferases (GST. Cellular ROS-sensing mechanisms are not well understood, but a number of transcription factors that regulate the expression of antioxidant genes are well characterized in prokaryotes and in yeast. In higher eukaryotes, oxidative stress responses are more complex and modulated by several regulators. In mammalian systems, two classes of transcription factors, nuclear factor kB and activator protein-1, are involved in the oxidative stress response. Antioxidant-specific gene induction, involved in xenobiotic metabolism, is mediated by the "antioxidant responsive element" (ARE commonly found in the promoter region of such genes. ARE is present in mammalian GST, metallothioneine-I and MnSod genes, but has not been found in plant Gst genes. However, ARE is present in the promoter region of the three maize catalase (Cat genes. In plants, ROS have been implicated in the damaging effects of various environmental stress conditions. Many plant defense genes are activated in response to these conditions, including the three maize Cat and some of the superoxide dismutase (Sod genes.

  2. Borderline psychopathology and the defense mechanism test

    OpenAIRE

    Sundbom, Elisabet

    1992-01-01

    The main purpose of the present studies has been to develop the Defense Mechanism Test (DM1) for clinical assessment of severe psychopathology with the focus on the concept of Borderline Personality Organization (BPO) according to Kemberg. By relating the DMT and the Structural Interview to each other, the concurrent validity of the concept of Personality Organization (PO) for psychiatric inpatients has been investigated. Two different assessment approaches have been used for this purpose. On...

  3. Involvement of Polyamine Oxidase in Abscisic Acid induced Cytosolic Antioxidant Defense in Leaves of Maize

    Institute of Scientific and Technical Information of China (English)

    Beibei Xue; Aying Zhang; Mingyi Jiang

    2009-01-01

    Using pharmacological and biochemical approaches, the role of maize polyamine oxidase (MPAO) in abscisic acid (ABA)induced antioxidant defense in leaves of maize (Zea mays L.) plants was investigated. Exogenous ABA treatment enhanced the expression of the MPAO gene and the activities of apoplastic MPAO. Pretreatment with two different inhibitors for apoplastic MPAO partly reduced hydrogen peroxide (H2O2) accumulation induced by ABA and blocked the ABA-induced expression of the antioxidant genes superoxide dismutase 4 and cytosolic ascorbate peroxidase and the activities of the cytosolic antioxidant enzymes. Treatment with spermidine, the optimum substrate of MPAO, also induced the expression and the activities of the antioxidant enzymes, and the upregulation of the antioxidant enzymes was prevented by two inhibitors of MPAO and two scavengers of H2O2. These results suggest that MPAO contributes to ABA-induced cytosolic antioxidant defense through H2O2, a Spd catabolic product.

  4. Rock mechanics contributions from defense programs

    International Nuclear Information System (INIS)

    An attempt is made at illustrating the many contributions to rock mechanics from US defense programs, over the past 30-plus years. Large advances have been achieved in the technology-base area covering instrumentation, material properties, physical modeling, constitutive relations and numerical simulations. In the applications field, much progress has been made in understanding and being able to predict rock mass behavior related to underground explosions, cratering, projectile penetration, and defense nuclear waste storage. All these activities stand on their own merit as benefits to national security. But their impact is even broader, because they have found widespread applications in the non-defense sector; to name a few: the prediction of the response of underground structures to major earthquakes, the physics of the earth's interior at great depths, instrumentation for monitoring mine blasting, thermo-mechanical instrumentation useful for civilian nuclear waste repositories, dynamic properties of earthquake faults, and transient large-strain numerical modeling of geological processes, such as diapirism. There is not pretense that this summary is exhaustive. It is meant to highlight success stories representative of DOE and DOD geotechnical activities, and to point to remaining challenges

  5. Rock mechanics contributions from defense programs

    Energy Technology Data Exchange (ETDEWEB)

    Heuze, F.E.

    1992-02-01

    An attempt is made at illustrating the many contributions to rock mechanics from US defense programs, over the past 30-plus years. Large advances have been achieved in the technology-base area covering instrumentation, material properties, physical modeling, constitutive relations and numerical simulations. In the applications field, much progress has been made in understanding and being able to predict rock mass behavior related to underground explosions, cratering, projectile penetration, and defense nuclear waste storage. All these activities stand on their own merit as benefits to national security. But their impact is even broader, because they have found widespread applications in the non-defense sector; to name a few: the prediction of the response of underground structures to major earthquakes, the physics of the earth`s interior at great depths, instrumentation for monitoring mine blasting, thermo-mechanical instrumentation useful for civilian nuclear waste repositories, dynamic properties of earthquake faults, and transient large-strain numerical modeling of geological processes, such as diapirism. There is not pretense that this summary is exhaustive. It is meant to highlight success stories representative of DOE and DOD geotechnical activities, and to point to remaining challenges.

  6. Prevalence and Mechanisms of Dynamic Chemical Defenses in Tropical Sponges

    OpenAIRE

    Rohde, Sven; Nietzer, Samuel; Schupp, Peter J

    2015-01-01

    Sponges and other sessile invertebrates are lacking behavioural escape or defense mechanisms and rely therefore on morphological or chemical defenses. Studies from terrestrial systems and marine algae demonstrated facultative defenses like induction and activation to be common, suggesting that sessile marine organisms also evolved mechanisms to increase the efficiency of their chemical defense. However, inducible defenses in sponges have not been investigated so far and studies on activated d...

  7. Defense Mechanism and Optimism in Korean College Students

    OpenAIRE

    Eun-Joo Hong; Hyo-Eun Kim; Jin-Kyung Kim

    2014-01-01

    The objective of this study was to illustrate the relationship between optimism and defense mechanism in Korean college students. 332 student participants from “A” University in Korea completed questionnaires from the Ewah defense mechanism and optimism measurement tool. This study analyzed the culled data and revealed general patterns of optimism and defense mechanism, as well as patterns based on gender. In addition, the study analyzed differences in defense mechanism...

  8. Narcissism and defense mechanisms in women

    Directory of Open Access Journals (Sweden)

    Sabina Bele

    2014-06-01

    Full Text Available The purpose of this research was to examine how the level of covert and overt narcissism is connected to the frequency of the use of defense mechanisms such as denial, repression, regression, projection, compensation, projection, intellectualization, reaction formation, displacement, dissociation, and somatoform dissociation. We can distinguish healthy narcissism, an appropriate self-evaluation, from pathological narcissism, unrealistic self-evalutaion hiding sense of one's own unworthiness with self-idealization and grandiose thinking. When combined with low/no empathy and exploiting of others, one is diagnosed with narcissistic personality disorder. In this research we focused on narcissism as a personality trait, keeping in mind that we can differentiate between more covert or overt form of narcissism. We also focused on defense mechanisms protecting an individual from stimuli that are either endangering self-esteem or produce anxiety. Although their use is often unconscious, recent findings support the thesis that an individual can observe and report them. Our sample comprised 203 women. We used Narcissistic Personality Inventory, The Hypersensitive Narcissism Scale, The Life Style Index, The Dissociative Experience Scale, and Somatoform Dissociation Questionnaire. Results indicated that women with higher levels of covert narcissism as a personality trait use defense mechanisms, especially regression on earlier developmental stage, compensation deficits on other areas, projection unwanted or unacceptable aspects, reaction formation, and dissociation (absorption, depersonalization and derealization more often than women with higher levels of overt narcissism. The later use more compensation as a way of dealing with loss, intellectualization as a rational response instead of emotional one, and regression.

  9. Mechanisms of Defense: Nepenthe Theory and Psychiatric Symptomatology

    Science.gov (United States)

    Azibo, Daudi Ajani ya

    2007-01-01

    Results of exploratory research on defense mechanisms and psychiatric symptomatology are reported about Black students enrolled in classes on the campus of one Historically Black College and University. Theoretical influences are twofold: ego mechanisms of defense conceptualized hierarchically and a culture-specific view of defense mechanism…

  10. Defense mechanisms of normal and tumor cells

    International Nuclear Information System (INIS)

    This paper reviews the protective systems of normal and tumor cells against chemical and radiation injury. The glutathione redox cycle is an important cell defense system that can be compromised by various chemical modifiers. Acute cell injury can involve the glutathione pools of both the cytosol and the mitochondria. Intracellular calcium may have a role in cell death following acute cell injury but extracellular calcium does not seem to initiate the events leading to cell death. Changes in the glutathione redox status affects the distribution of intracellular calcium and the protein thiol-disulfide redox status. Formation of glutathione protein-mixed disulfides is discussed in terms of a possible protective mechanism against oxidative injury. 46 references

  11. Predator Defense Mechanisms in Shallow Water Sea Cucumbers (Holothuroidea)

    OpenAIRE

    Castillo, Jessica A.

    2006-01-01

    The various predator defense mechanisms possessed by shallow water sea cucumbers were surveyed in twelve different species and morphs. While many defense mechanisms such as the presence of Cuverian tubules, toxic secretions, and unpalatability have been identified in holothurians, I hypothesized that the possession of these traits as well as the degree to which they are utilized varies from species to species. The observed defense mechanisms were compared against a previously-derived phylogen...

  12. Brain stem and thalamus antioxidative defense in experimental sepsis

    OpenAIRE

    Ninković Milica; Maličević Ž.; Stojanović Dragica; Vasiljević Ivana; Jovanović Marina; Đukić Mirjana

    2008-01-01

    Although brain complications in sepsis are not rare, early pathophysiologic events had not been made clear yet. We have considered antioxidative components-glutathione peroxidase (GSHPx) activity and reduced glutathione (GSH) concentration in two brain integrative centers, i.e the brain stem (BS) and thalamus. Sepsis was induced in adult male Wistar rats (200-250 g) by cecal ligation and perforation (CLP) with inoculation of Escherichia coli suspension (ATCC 25922) (n=40). The control group w...

  13. Ginsan activated the antioxidant defense systems in irradiated mice

    International Nuclear Information System (INIS)

    Ginsan, a polysaccharide extracted from Panax ginseng, has hematopoietic activity and is also known as a good biological-response modifier. In this investigation, we studied the effects of ginsan on the γ-radiation induced alterations of some antioxidant systems in spleen of Balb/c mice. There are many data that irradiation induces Reactive Oxygen Species (ROS), which plays an important causative role in radiation damage of cell. The level of ROS in cells is regulated by enzymatic and nonenzymatic antioxidant systems. The most powerful ones among them are superoxide dismutases (SODs) catalyzing the dismutation of superoxide anion radical o2 to H2O2, catalase deactivating h-2O2 and reduced glutathion (GSH) detoxifying H2O2 and other ROS> At the 5th day after sublethal whole body irradiation, splenocytes of irradiated mice expressed only marginally increased levels of Mn-SOD, however, Cu/Zn-SOD, catalase, thioredoxine reductase (TR) and thioredoxine (TRX) mRNA (135% increase compared to control), however, the combination of irradiation with ginsan increased the SODs and GPX production more effectively. In addition to the above results, we obtained the similar data of protein expression. The enzyme activities of SOD, catalase, and GPX of ginsan-treated and irradiated mice were significantly enhanced by 140, 115, 126% respectively, compared with those of irradiated mice. Based on these results, we propose that the induction of antioxidant enzymes of ginsan is at least in part due to its capacity to protect against radiation

  14. Protective Effects of Zinc Against Acute Arsenic Toxicity by Regulating Antioxidant Defense System and Cumulative Metallothionein Expression.

    Science.gov (United States)

    Ganger, Renuka; Garla, Roobee; Mohanty, Biraja Prasad; Bansal, Mohinder Pal; Garg, Mohan Lal

    2016-02-01

    Arsenic (As), a toxic metalloid, is one of the major global concerns. The toxicity resulting from As exposure is linked to the generation of reactive oxygen intermediates during their redox cycling and metabolic activation processes that cause lipid peroxidation (LPO). Zinc (Zn), a redox-inactive metal, helps to maintain cellular functions because of its prominent role in antioxidant network through multiple mechanisms. The present study, therefore, explores the effectiveness of administered Zn to combat against acute As toxicity by analysis of antioxidant defense status, alkaline phosphatase (ALP) activity, histological profile, MT expression, and elemental status in rat liver. To achieve this goal, four experimental groups, one control and three receiving different metal supplementations, were chosen (group 1, control; group 2, Zn supplemented; group 3, As substituted; group 4, Zn + As supplemented). The levels of reduced glutathione (GSH) and activities of glutathione reductase (GR) and ALP were lowered, whereas LPO levels and activity of superoxide dismutase (SOD) were elevated with no significant change in catalase (CAT) activity. Histopathological changes were also observed in the As substituted group in comparison to the control. Particle-induced X-ray emission (PIXE) analysis showed decrease in Fe and S concentration in rat liver after As intoxication, whereas As was below detection limit, i.e., <1 ppm. Zn administration almost restored the antioxidants, ALP activity, histopathological changes, and elemental status. A cumulative increase in MT expression was found with the combined treatment of Zn and As. Also, Zn alone caused no significant change in the antioxidant defense system. It can be concluded that restoration of antioxidant activity and increased MT expression are the two independent protective mechanisms of Zn to reduce acute As toxicity. PMID:26113309

  15. Differential stimulation of antioxidant defense in various organs of mice after whole body exposure to low-dose gamma radiation

    International Nuclear Information System (INIS)

    It has been generally considered that any dose of ionizing radiation is detrimental to the living organisms, however low the radiation dose may be. The much relied upon 'Linear-No-Threshold' (LNT) hypothesis dose not have any convincing experimental evidence regarding the damaging effects at very low-doses and low-dose rates. Generally, the deleterious biological effects have been inferred theoretically by extrapolating the known effects of high radiation dose to low-dose range. Recently, it has been reported that the living organisms do not respond to ionizing radiations in a linear manner in the low-dose range 0.01-0.50 Gy and rather restore the homeostasis both in-vivo and in-vitro by normal physiological mechanisms such as, cellular and DNA repair processes, immune reactions, antioxidant defense, adaptive responses, activation of immune functions; stimulation of growth etc. In this study, we have attempted to find: (i) the critical radiation dose range and the post irradiation period during which the antioxidant defense systems in the lungs, liver and kidneys remain stimulated; and (ii) to evaluate the degree to which these defense mechanisms remain stimulated in these organs after whole body exposure of the animal to low-dose radiation

  16. Molecular mechanisms of epithelial host defense in the airways

    OpenAIRE

    Vos, Joost Bastiaan

    2007-01-01

    Airway epithelial cells are indispensable for the host defense system in the lungs. Various strategies by which epithelial cells protect the lungs against inhaled pathogens have been described. In spite of that, the molecular mechanisms by which epithelial cells initiate and control the host defense response have not been explored systematically. In this thesis, the molecular mechanisms underlying the initiation and regulation of the early epithelial host defense response in the airways were ...

  17. Ego Defenses and Reaction to Stress: A Validation Study of the Defense Mechanisms Inventory

    Science.gov (United States)

    Gleser, Goldine C.; Sacks, Marilyn

    1973-01-01

    This study investigated the relationship between scores on the Defense Mechanisms Inventory and reaction to an experimental conflict situation in which Ss (85 undergraduate college students) were led to believe that their performance was deficient on a new test of scholastic ability. The pattern of defenses predicted residual posttest estimates of…

  18. Thyroid status and antioxidant defense in pregnant women living at territories contaminated with radionuclides in Belarus

    International Nuclear Information System (INIS)

    Thyroid function, lipid peroxidation (LPO) products content and antioxidant defense in pregnant women living at territories contaminated with radionuclides in Belarus are studied. The levels of malonic dialdehyde, vitamins A, C and E, reduced glutathion, and activity of enzymatic antioxidants were measured in the blood of 60 women living in Minsk and 90 pregnant women living at territories contaminated with radionuclides. The functions of the thyroid was assessed from the blood levels of tri-iodothyronine, thyroxin, thyroidbinding globulin, and T4/TSH ratio. It is shown that the content of LPO products is increased higher and the levels of antioxidant vitamins and reduced glutathion decreased lower in the residents of contaminated territories. Changes in the activity of antioxidant enzymes in pregnant women depend on the function of the thyroid

  19. Adversity Quotient and Defense Mechanism of Secondary School Students

    Science.gov (United States)

    Nikam, Vibhawari B.; Uplane, Megha M.

    2013-01-01

    The present study was conducted to explore the relationship between Adversity Quotient (AQ) and Defense Mechanism (DM) of secondary school students. The aim of the study was to ascertain relationship between Adversity Quotient and Defense mechanism i. e. Turning against object (TAO), Projection (PRO), Turning against self (TAS), Principalisation…

  20. Influence of fasting on muscle composition and antioxidant defenses of market-size Sparus macrocephalus *

    OpenAIRE

    Zhang, Xiao-dong; Wu, Tian-xing; Cai, Li-sheng; Zhu, Yong-fei

    2007-01-01

    The study was conducted to investigate fasting effects on flesh composition and antioxidant defenses of market-size Sparus macrocephalus. Two hundred fish (main initial weight 580 g) were divided into two groups (control and fasted) and reared in 6 cages. After two weeks of adaptation, group I fasted for 28 d; group II was fed normally as a control. In 3, 7, 14, 21 and 28 d, 6 fish per group were sampled for proximate flesh composition, liver antioxidant enzyme activities and malondialdehyde ...

  1. Polyphenol oxidase as a biochemical seed defense mechanism

    OpenAIRE

    Fuerst, E. Patrick; Okubara, Patricia A.; Anderson, James V.; Morris, Craig F.

    2014-01-01

    Seed dormancy and resistance to decay are fundamental survival strategies, which allow a population of seeds to germinate over long periods of time. Seeds have physical, chemical, and biological defense mechanisms that protect their food reserves from decay-inducing organisms and herbivores. Here, we hypothesize that seeds also possess enzyme-based biochemical defenses, based on induction of the plant defense enzyme, polyphenol oxidase (PPO), when wild oat (Avena fatua L.) caryopses and seeds...

  2. Effects of aerial exposure on antioxidant defenses in the brown mussel Perna perna

    Directory of Open Access Journals (Sweden)

    Eduardo Alves de Almeida

    2006-03-01

    Full Text Available Investigations were carried out to evaluate the antioxidant defenses in digestive gland of mussels Perna perna held in air for 4 hours, exposed to air for 4 hours followed by submersion in water for 30 minutes, and constantly submerged for 4.5 hours. No differences were observed in CAT and GPx activities and in the levels of total GSH. Mussels exposed to air had significantly higher SOD activity, possibly related to a preparative mechanism of defense against oxidative stress during reoxygenation.Mexilhões são periodicamente submetidos a condições de hipóxia seguido de normóxia, como resultado das oscilações nos níveis de maré. Tais condições podem causar um aumento na produção de espécies reativas de oxigenio (EROs nos tecidos, devido a um aumento no fluxo de oxigênio e de equivalentes redutores. Para proteger as células contra as EROs, os organismos possuem enzimas antioxidantes tais como a superóxido dismutase (SOD, catalase (CAT e glutationa peroxidase (GPx, assim como o tripeptídeo glutationa (GSH. Neste trabalho, estas defesas antioxidantes foram avaliadas em glândulas digestivas de mexilhões Perna perna expostos ao ar por 4 horas seguido de re-submersão em água do mar por 30 minutos e constantemente submersos por 4,5 horas. Nenhuma diferença foi observada nas atividades da CAT e GPx, assim como nos níveis de GSH total. Mexilhões expostos ao ar tiveram atividade da SOD significativamente maior, possivelmente relacionado a um mecanismo de defesa preparativo contra o estresse oxidativo durante a reoxigenação.

  3. Dosakaya Juice Assuages Development of Sucrose Induced Impaired Glucose Tolerance and Imbalance in Antioxidant Defense

    OpenAIRE

    Kumar, Dommati Anand; Pisupati S.R Sweeya; Shukla, Srishti; Anusha, Sanga Venkata; Akshara, Dasari; Madhusudana, Kuncha; Tiwari, Ashok Kumar

    2015-01-01

    Objective: The objective was to explore the effect of Dosakaya (DK) (Cucumis melo var. chito) juice on sucrose induced dysglycemia and disturbances in antioxidant defense in rats. Materials and Methods: Rats were preconditioned with DK juice before administration of sucrose beverage continuously for 1-month. Blood glucose tolerance test and glutathione (GSH) homeostasis pathways in kidney were analyzed in different group of animals at the end of the study. Results: DK juice diffused (P < 0.00...

  4. The Cryptococcus neoformans Catalase Gene Family and Its Role in Antioxidant Defense

    OpenAIRE

    Giles, Steven S.; Jason E. Stajich; Nichols, Connie; Gerrald, Quincy D.; Alspaugh, J. Andrew; Dietrich, Fred; Perfect, John R.

    2006-01-01

    In the present study, we sought to elucidate the contribution of the Cryptococcus neoformans catalase gene family to antioxidant defense. We employed bioinformatics techniques to identify four members of the C. neoformans catalase gene family and created mutants lacking single or multiple catalase genes. Based on a phylogenetic analysis, CAT1 and CAT3 encode putative spore-specific catalases, CAT2 encodes a putative peroxisomal catalase, and CAT4 encodes a putative cytosolic catalase. Only Ca...

  5. The Composite Measure of the Defense Mechanism Inventory.

    Science.gov (United States)

    Juni, Samuel

    1982-01-01

    Reanalysis of previously published data suggests the Defense Mechanism Inventory can yield a composite measure of reaction to frustration by contrasting linearly the defenses Turning-against-object and Projection against those of Principalization and Reversal-of-affect. Factor-analytic and correlational data support the exclusion of…

  6. Antioxidant Defenses in Plants with Attention to Prunus and Citrus spp.

    Directory of Open Access Journals (Sweden)

    Milvia Luisa Racchi

    2013-11-01

    Full Text Available This short review briefly introduces the formation of reactive oxygen species (ROS as by-products of oxidation/reduction (redox reactions, and the ways in which the antioxidant defense machinery is involved directly or indirectly in ROS scavenging. Major antioxidants, both enzymatic and non enzymatic, that protect higher plant cells from oxidative stress damage are described. Biochemical and molecular features of the antioxidant enzymes superoxide dismutase (SOD, catalase (CAT, and ascorbate peroxidase (APX are discussed because they play crucial roles in scavenging ROS in the different cell compartments and in response to stress conditions. Among the non enzymatic defenses, particular attention is paid to ascorbic acid, glutathione, flavonoids, carotenoids, and tocopherols. The operation of ROS scavenging systems during the seasonal cycle and specific developmental events, such as fruit ripening and senescence, are discussed in relation to the intense ROS formation during these processes that impact fruit quality. Particular attention is paid to Prunus and Citrus species because of the nutritional and antioxidant properties contained in these commonly consumed fruits.

  7. Iron-ascorbate-mediated lipid peroxidation causes epigenetic changes in the antioxidant defense in intestinal epithelial cells: impact on inflammation.

    Directory of Open Access Journals (Sweden)

    Sabrina Yara

    Full Text Available INTRODUCTION: The gastrointestinal tract is frequently exposed to noxious stimuli that may cause oxidative stress, inflammation and injury. Intraluminal pro-oxidants from ingested nutrients especially iron salts and ascorbic acid frequently consumed together, can lead to catalytic formation of oxygen-derived free radicals that ultimately overwhelm the cellular antioxidant defense and lead to cell damage. HYPOTHESIS: Since the mechanisms remain sketchy, efforts have been exerted to evaluate the role of epigenetics in modulating components of endogenous enzymatic antioxidants in the intestine. To this end, Caco-2/15 cells were exposed to the iron-ascorbate oxygen radical-generating system. RESULTS: Fe/Asc induced a significant increase in lipid peroxidation as reflected by the elevated formation of malondialdehyde along with the alteration of antioxidant defense as evidenced by raised superoxide dismutase 2 (SOD2 and diminished glutathione peroxidase (GPx activities and genes. Consequently, there was an up-regulation of inflammatory processes illustrated by the activation of NF-κB transcription factor, the higher production of interleukin-6 and cycloxygenase-2 as well as the decrease of IκB. Assessment of promoter's methylation revealed decreased levels for SOD2 and increased degree for GPx2. On the other hand, pre-incubation of Caco-2/15 cells with 5-Aza-2'-deoxycytidine, a demethylating agent, or Trolox antioxidant normalized the activities of SOD2 and GPx, reduced lipid peroxidation and prevented inflammation. CONCLUSION: Redox and inflammatory modifications in response to Fe/Asc -mediated lipid peroxidation may implicate epigenetic methylation.

  8. Biomarkers of oxidative stress and of antioxidative defense: Relationship to intervention with antioxidant-rich foods

    DEFF Research Database (Denmark)

    Dragsted, Lars Ove; Young, Jette Feveile; Loft, Steffen;

    2001-01-01

    The antioxidant actions of single food items or extracts rich in flavonoids (e.g., apple and black currant juice, grape skin extract, tea extract and parsley) were evaluated in short-term human trials [Denmark; date not given]. An overall weak trend toward decreased lipid oxidation with increased...

  9. An Active Defense Mechanism for TCP SYN flooding attacks

    CERN Document Server

    Kumarasamy, Saravanan

    2012-01-01

    Distributed denial-of-service attacks on public servers have recently become a serious problem. To assure that network services will not be interrupted and more effective defense mechanisms to protect against malicious traffic, especially SYN floods. One problem in detecting SYN flood traffic is that server nodes or firewalls cannot distinguish the SYN packets of normal TCP connections from those of a SYN flood attack. Another problem is single-point defenses (e.g. firewalls) lack the scalability needed to handle an increase in the attack traffic. We have designed a new defense mechanism to detect the SYN flood attacks. First, we introduce a mechanism for detecting SYN flood traffic more accurately by taking into consideration the time variation of arrival traffic. We investigate the statistics regarding the arrival rates of both normal TCP SYN packets and SYN flood attack packets. We then describe a new detection mechanism based on these statistics. Through the trace driven approach defense nodes which recei...

  10. Immune defense mechanisms in the Caenorhabditis elegans intestinal epithelium

    OpenAIRE

    Pukkila-Worley, Read; Ausubel, Frederick M.

    2012-01-01

    Intestinal epithelial cells provide an essential line of defense for Caenorhabditis elegans against ingested pathogens. Because nematodes consume microorganisms as their food source, there has presumably been selection pressure to evolve and maintain immune defense mechanisms within the intestinal epithelium. Here we review recent advances that further define the immune signaling network within these cells and suggest mechanisms used by the nematode to monitor for infection. In reviewing stud...

  11. Defense mechanisms development in children, adolescents, and late adolescents.

    Science.gov (United States)

    Porcerelli, J H; Thomas, S; Hibbard, S; Cogan, R

    1998-12-01

    To replicate and extend Cramer's (1987) original cross-sectional study concerning the development of defense mechanisms, the Thematic Apperception Test responses of 148 students in Grades 2, 5, 8, 11, and college freshmen were collected and scored for denial, projection, and identification using Cramer's Defense Mechanisms Manual (1991). Our results supported the notion that the relative use of denial and projection decreases and identification increases as a function of grade level. The findings provide additional support for the psychoanalytic view (Freud, 1966) of an ontogenetic developmental line of defense. PMID:9933944

  12. Polyphenol Oxidase as a Biochemical Seed Defense Mechanism

    Directory of Open Access Journals (Sweden)

    E. Patrick Fuerst

    2014-12-01

    Full Text Available Seed dormancy and resistance to decay are fundamental survival strategies, which allow a population of seeds to germinate over long periods of time. Seeds have physical, chemical, and biological defense mechanisms that protect their food reserves from decay-inducing organisms and herbivores. Here, we hypothesize that seeds also possess enzyme-based biochemical defenses, based on induction of the plant defense enzyme, polyphenol oxidase (PPO, when wild oat (Avena fatua L. caryopses and seeds were challenged with seed-decaying Fusarium fungi. These studies suggest that dormant seeds are capable of mounting a defense response to pathogens. The pathogen-induced PPO activity from wild oat was attributed to a soluble isoform of the enzyme that appeared to result, at least in part, from proteolytic activation of a latent PPO isoform. PPO activity was also induced in wild oat hulls (lemma and palea, non-living tissues that cover and protect the caryopsis. These results are consistent with the hypothesis that seeds possess inducible enzyme-based biochemical defenses arrayed on the exterior of seeds and these defenses represent a fundamental mechanism of seed survival and longevity in the soil. Enzyme-based biochemical defenses may have broader implications since they may apply to other defense enzymes as well as to a diversity of plant species and ecosystems.

  13. Broad specificity AhpC-like peroxiredoxin and its thioredoxin reductant in the sparse antioxidant defense system of Treponema pallidum

    Science.gov (United States)

    Parsonage, Derek; Desrosiers, Daniel C.; Hazlett, Karsten R. O.; Sun, Yongcheng; Nelson, Kimberly J.; Cox, David L.; Radolf, Justin D.; Poole, Leslie B.

    2010-01-01

    Little is known about the mechanisms by which Treponema pallidum (Tp), the causative agent of syphilis, copes with oxidative stress as it establishes persistent infection within its obligate human host. The Tp genomic sequence indicates that the bacterium’s antioxidant defenses do not include glutathione and are limited to just a few proteins, with only one, TP0509, offering direct defense against peroxides. Although this Tp peroxiredoxin (Prx) closely resembles AhpC-like Prxs, Tp lacks AhpF, the typical reductant for such enzymes. Functionally, TpAhpC resembles largely eukaryotic, nonAhpC typical 2-Cys Prx proteins in using thioredoxin (Trx, TP0919) as an efficient electron donor and exhibiting broad specificity toward hydroperoxide substrates. Unlike many of the eukaryotic Prxs, however, TpAhpC is relatively resistant to inactivation during turnover with hydroperoxide substrates. As is often observed in typical 2-Cys Prxs, TpAhpC undergoes redox-sensitive oligomer formation. Quantitative immunoblotting revealed that TpTrx and TpAhpC are present at very high levels (over 100 and 300 μM, respectively) in treponemes infecting rabbit testes; their redox potentials, at -242 ± 1 and -192 ± 2 mV, respectively, are consistent with the role of TpTrx as the cellular reductant of TpAhpC. Transcriptional analysis of select antioxidant genes confirmed the presence of high mRNA levels for ahpC and trx which diminish greatly when spirochetes replicate under in vitro growth conditions. Thus, T. pallidum has evolved an extraordinarily robust, broad-spectrum AhpC as its sole mechanism for peroxide defense to combat this significant threat to treponemal growth and survival during infection. PMID:20304799

  14. Neonatal SSRI exposure improves mitochondrial function and antioxidant defense in rat heart.

    Science.gov (United States)

    Braz, Glauber Ruda F; Freitas, Cristiane M; Nascimento, Luciana; Pedroza, Anderson A; da Silva, Aline Isabel; Lagranha, Claudia

    2016-04-01

    Protein restriction during prenatal, postnatal, or in both periods has a close relationship with subsequent development of cardiovascular disease in adulthood. Elevated brain levels of serotonin and its metabolites have been found in malnourished states. The aim in the present study was to investigate whether treatment with fluoxetine (Fx), a selective serotonin reuptake inhibitor, mimics the detrimental effect of low-protein diet during the perinatal period on the male rat heart. Our hypothesis is that increased circulating serotonin as a result of pharmacologic treatment with Fx leads to cardiac dysfunction similar to that observed in protein-restricted rats. Male Wistar rat pups received daily subcutaneous injection of Fx or vehicle from postnatal day 1 to postnatal day 21. Male rats were euthanized at 60 days of age and the following parameters were evaluated in the cardiac tissue: mitochondrial respiratory capacity, respiratory control ratio, reactive oxygen species (ROS) production, mitochondrial membrane potential, and biomarkers of oxidative stress and antioxidant defense. We found that Fx treatment increased mitochondrial respiratory capacity (123%) and membrane potential (212%) and decreased ROS production (55%). In addition we observed an increase in the antioxidant capacity (elevation in catalase activity (5-fold) and glutathione peroxidase (4.6-fold)). Taken together, our results suggest that Fx treatment in the developmental period positively affects the mitochondrial bioenergetics and antioxidant defense in the cardiac tissue. PMID:26939042

  15. Modulatory influence of Phyllanthus niruri on oxidative stress, antioxidant defense and chemically induced skin tumors.

    Science.gov (United States)

    Sharma, Priyanka; Parmar, Jyoti; Verma, Preeti; Goyal, Pradeep Kumar

    2011-01-01

    The present study evaluates the modulatory potential of Phyllanthus niruri on chemically induced skin carcinogenesis, and its influence on oxidative stress and the antioxidant defense system. Oral administration of P. niruri extract (PNE), during peri- (Gr. III), post- (Gr. IV), or peri- and post- (Gr. V) initiational stages of 7,12-dimethylbenz(a) anthracene (DMBA)-croton oil–induced papillomagenesis considerably reduced tumor burden to 4.20, 4.00, and 3.33(positive control value 6.20); cumulative number of papillomas to 21, 16, and 10, respectively, (positive control value 62); and incidence of mice bearing papillomas to 50, 40, and 30%, respectively (positive control value 100%), but significantly increased the average latent period to 10.14, 10.62, and 11.60, and inhibition of tumor multiplicity to 66, 74,and 83%, respectively. Enzyme analysis of skin and liver showed a significant (p ≤ 0.05, ≤ 0.01, ≤ 0.001) elevation in antioxidant parameters such as superoxide dismutase, catalase, glutathione, and vitamin C in PNE-treated groups (Gr. III–V) when compared with the carcinogen-treated control (Gr. II). The elevated level of lipid peroxidation in the carcinogen-treated positive control group was significantly (p ≤ 0.05, ≤ 0.01, ≤ 0.001) inhibited by PNE administration. These results indicate that P. niruri extract has potentiality to reduce skin papillomas by enhancing antioxidant defense system. PMID:21609315

  16. Role of Nrf2 antioxidant defense in mitigating cadmium-induced oxidative stress in the olfactory system of zebrafish

    International Nuclear Information System (INIS)

    Exposure to trace metals can disrupt olfactory function in fish leading to a loss of behaviors critical to survival. Cadmium (Cd) is an olfactory toxicant that elicits cellular oxidative stress as a mechanism of toxicity while also inducing protective cellular antioxidant genes via activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, the molecular mechanisms of Cd-induced olfactory injury have not been characterized. In the present study, we investigated the role of the Nrf2-mediated antioxidant defense pathway in protecting against Cd-induced olfactory injury in zebrafish. A dose-dependent induction of Nrf2-regulated antioxidant genes associated with cellular responses to oxidative stress was observed in the olfactory system of adult zebrafish following 24 h Cd exposure. Zebrafish larvae exposed to Cd for 3 h showed increased glutathione S-transferase pi (gst pi), glutamate–cysteine ligase catalytic subunit (gclc), heme oxygenase 1 (hmox1) and peroxiredoxin 1 (prdx1) mRNA levels indicative of Nrf2 activation, and which were blocked by morpholino-mediated Nrf2 knockdown. The inhibition of antioxidant gene induction in Cd-exposed Nrf2 morphants was associated with disruption of olfactory driven behaviors, increased cell death and loss of olfactory sensory neurons (OSNs). Nrf2 morphants also exhibited a downregulation of OSN-specific genes after Cd exposure. Pre-incubation of embryos with sulforaphane (SFN) partially protected against Cd-induced olfactory tissue damage. Collectively, our results indicate that oxidative stress is an important mechanism of Cd-mediated injury in the zebrafish olfactory system. Moreover, the Nrf2 pathway plays a protective role against cellular oxidative damage and is important in maintaining zebrafish olfactory function. -- Highlights: ► Oxidative stress is an important mechanism of Cd-mediated olfactory injury. ► Cd induces antioxidant gene expression in the zebrafish olfactory system. ► The

  17. Role of Nrf2 antioxidant defense in mitigating cadmium-induced oxidative stress in the olfactory system of zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lu; Gallagher, Evan P., E-mail: evang3@uw.edu

    2013-01-15

    Exposure to trace metals can disrupt olfactory function in fish leading to a loss of behaviors critical to survival. Cadmium (Cd) is an olfactory toxicant that elicits cellular oxidative stress as a mechanism of toxicity while also inducing protective cellular antioxidant genes via activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, the molecular mechanisms of Cd-induced olfactory injury have not been characterized. In the present study, we investigated the role of the Nrf2-mediated antioxidant defense pathway in protecting against Cd-induced olfactory injury in zebrafish. A dose-dependent induction of Nrf2-regulated antioxidant genes associated with cellular responses to oxidative stress was observed in the olfactory system of adult zebrafish following 24 h Cd exposure. Zebrafish larvae exposed to Cd for 3 h showed increased glutathione S-transferase pi (gst pi), glutamate–cysteine ligase catalytic subunit (gclc), heme oxygenase 1 (hmox1) and peroxiredoxin 1 (prdx1) mRNA levels indicative of Nrf2 activation, and which were blocked by morpholino-mediated Nrf2 knockdown. The inhibition of antioxidant gene induction in Cd-exposed Nrf2 morphants was associated with disruption of olfactory driven behaviors, increased cell death and loss of olfactory sensory neurons (OSNs). Nrf2 morphants also exhibited a downregulation of OSN-specific genes after Cd exposure. Pre-incubation of embryos with sulforaphane (SFN) partially protected against Cd-induced olfactory tissue damage. Collectively, our results indicate that oxidative stress is an important mechanism of Cd-mediated injury in the zebrafish olfactory system. Moreover, the Nrf2 pathway plays a protective role against cellular oxidative damage and is important in maintaining zebrafish olfactory function. -- Highlights: ► Oxidative stress is an important mechanism of Cd-mediated olfactory injury. ► Cd induces antioxidant gene expression in the zebrafish olfactory system. ► The

  18. Consequences of Social Isolation in Rats on Their Antioxidant Defense System and Erythrocyte Deformability

    Directory of Open Access Journals (Sweden)

    Sami Aydoğan

    2009-02-01

    Full Text Available Purpose: In this study, our purpose was to investigate effect of oxidative stress composing in isolated rats on erythrocyte deformability and antioxidant system, considering importance of mechanical, and biochemical properties of erythrocytes in efficiency of blood circulationMaterial and Methods: Fourty Sprague-Dawley rats were divided into two groups according to their ages; where one of them consisted of 2 months old rats and the other 12 months old rats. Then, randomly selected ten rats in each group were isolated separately in a cage and hold 12/12 hour light-dark cycle lasting 21 days. Blood samples were collected at the end of the 21st day, and superoxide dismutase (SOD, catalase (CAT activities and malondialdehyde (MDA levels were measured spectrophotometrically. Changes in plasma nitric oxide level were determined by Griess method depending on total nitrite-nitrate. In addition, relative filtration rate (RFR, relative filtration time (RFT and relative resistance (Rrel of the erythrocytes were calculated as the indexes of erythrocyte deformability.Results: The SOD and CAT levels were found significantly lower in both of young and adult isolated rats when compared to the young and adult control groups. The nitric oxide levels were also found significantly lower in the young and adult isolated rats when compared to their control groups. The peroxidation of the lipids were also decreased by social isolation, in the erythrocyte membrane of both young and adult isolated rats compared to the controls. The indexes of erythrocyte deformability, RFR was found significantly higher, whereas the RFT was significantly lower in young and adult isolated rats compared to the young and adult controls. However, the Rrel of the erythrocytes were not altered dramatically.Conclusion: As a consequence, our data reveals that the social isolation causes a lack of plasma nitric oxide levels in the socially isolated rats and probably due to this decrease in one

  19. On the Defense Mechanisms in Mrs.Dalloway

    Institute of Scientific and Technical Information of China (English)

    韩瑞芳

    2008-01-01

    This article explores respecfivdy Mrs.Dalloway's and Septimus Smith's defense mechanisms in Mrs.Dalloway.Either Mrs.Dalloway or Septimus Smith mainly resortss unconsciously to defenses like repression and isolation discharged by fantasies or images they create and memories.Their causes of repression and isolation are analyzed in this article as the traumatic female development in Clarissa's cage and the scathing war experience in Smith's case.Besides this article especinlly elaborates on Septimus'death and Clarissa's life,which can be seen as defenses owing to the contamination of drives and ddenses in Freudian theory.

  20. Uranium induced ROS and its antioxidant defense molecules, genotoxicity assessment in iridescent shark (Pangasius sutchi)

    International Nuclear Information System (INIS)

    The potential adverse effects of uranium (U) contamination in the aquatic environment to living organisms have been debated during the recent years. In order to understand the effect and mode of action (MoA) of U in vivo, the iridescent shark (Pangasius sutchi) were exposed to ¼ and ½ LC50 waterborne uranyl nitrate in a static system till 21 days. The accumulation of U concentrations in the muscle, brain, gill and liver were analyzed by ICP-MS.The results clearly showed higher accumulation of U in the gills, and the accumulation were in the order of magnitude as gills > liver> Brain> tissue. Dose dependent effects of uranium on hepatic antioxidant defenses like super oxide dismutase, catalase and lipid peroxidase were observed and the ideal concentration-response relationships were observed at the highest U concentration. The DNA fragmentation analysis by comet assay and cell viability by flow cytometric analysis was performed at different time intervals. The whole blood analysis revealed aneuploidy-like patterns in the DNA histograms some fish, as well as hyper diploid shoulders of the G0/G1 peak. A significant differences in DNA damage occurred in fishes exposed protractedly and acutely to uranium compared to control. The higher the U concentration greater the effect observed suggested a close relationship between accumulation and effect. A possible ROS mediated U cytotoxic mechanism has been proposed. Studies on the uranium toxicity regulating genes can possibly be used as a tool to evaluate U toxicity which will be more sensitive than the enzymatic activities. However a multiple biomarker approach can be recommended as the perturbed pathways and the mode of action of this pollutant are not completely understood. (author)

  1. Effects of inhaled acids on respiratory tract defense mechanisms.

    OpenAIRE

    Schlesinger, R B

    1985-01-01

    The respiratory tract is endowed with an interlocking array of nonspecific and specific defense mechanisms which protect it from the effects of inhaled microbes and toxicants, and reduce the risk of absorption of materials into the bloodstream, with subsequent systemic translocation. Ambient acids may compromise these defenses, perhaps providing a link between exposure and development of chronic and acute pulmonary disease. This paper reviews the effects of inhaled acids upon the nonspecific ...

  2. Do defense mechanisms vary according to the psychiatric disorder?

    OpenAIRE

    Blaya Carolina; Dornelles Marina; Blaya Rodrigo; Kipper Letícia; Heldt Elizeth; Isolan Luciano; Bond Michael; Manfro Gisele Gus

    2006-01-01

    OBJECTIVE: The aim of this study was to evaluate the defense mechanisms used by depressive and anxious patients without comorbidities compared to those used by controls and to determine whether these patterns differ between diagnoses. METHOD: The sample was composed of 167 psychiatric patients and 36 controls that were evaluated using the Defense Style Questionnaire 40. All subjects were evaluated through a clinical interview, and each evaluation was confirmed through the application of the M...

  3. Intelligence, Coping and Psychological Defense Mechanisms for the Unemployed

    OpenAIRE

    Plaude, Alla

    2012-01-01

    The aim of the dissertation is to clarify whether analytical and emotional intelligence, coping and psychological defense mechanisms are different for the unemployed and the employed and what are interconnections between these variables. For achievement of the objective of the Doctorate Paper, for the first time in Latvia two questionnaires are adapted: Defense Style Questionnaire and Life Style Index, and in addition such tests as Woodcock-Johnson Tests of Cognitive Abilities International E...

  4. Effect of 3-bromopyruvic acid on human erythrocyte antioxidant defense system.

    Science.gov (United States)

    Sadowska-Bartosz, Izabela; Bartosz, Grzegorz

    2013-12-01

    3-Bromopyruvate (3-BP) is a promising compound for anticancer therapy, its main mode of action being the inhibition of glycolytic enzymes, but this compound also induces oxidative stress. This study aimed at characterisation of the effect of 3-BP on the antioxidant defense system of erythrocytes. Suspensions of erythrocytes in PBS containing 5 mM glucose were treated with different concentration of 3-BP at 37°C for 1 h. Activities of antioxidant enzymes were estimated by standard colorimetric methods. The antioxidant capacity of erythrocytes was estimated using the 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS(•+)) decolorisation assay and ferricyanide reduction. The content of reduced and oxidized glutathione was estimated fluorimetrically with o-phtalaldehyde. 3-BP did not affect the integrity of the erythrocyte membrane (lack of changes in the osmotic fragility). However, it induced oxidative stress in erythrocytes, as evidenced by the decrease in the content of acid-soluble thiols and reduced glutathione (GSH). Superoxide dismutase (SOD) and glutathione S-transferase (GST) activities were significantly decreased. 3-BP also decreased the transmembrane reduction of ferricyanide. Thus induction of oxidative stress in erythrocytes by 3-BP is due to depletion of glutathione and inhibition of antioxidant enzymes. PMID:23881849

  5. Gasoline effects on biotransformation and antioxidant defenses of the freshwater fish Prochilodus lineatus.

    Science.gov (United States)

    Simonato, Juliana D; Fernandes, Marisa Narciso; Martinez, Cláudia B R

    2011-08-01

    Biochemical biomarkers in the Neotropical freshwater fish Prochilodus lineatus were evaluated following acute exposures to the water-soluble fraction of gasoline (WSFG). Fish were exposed to the WSFG diluted to 5% in water (WSFG group) or only to water (Control group) for 6, 24 and 96 h and the gills and liver were removed for the biochemical analyses. Fish exposed to WSFG for 24 and 96 h showed significant increase in the activity of 7-ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST) both in liver and gills, pointing toward phase I and phase II biotransformation of the compounds present in the WSFG. The results also indicated the activation of antioxidant defenses in both the liver and gills after fish exposure to WSFG. The liver showed activation of catalase (CAT) and glutathione peroxidase (GPx) after 96 h exposure. An increase in hepatic content of reduced glutathione (GSH) together with decreased glutathione reductase (GR) activity was observed after 24 and 96 h of exposure to WSFG. In the gills, only catalase (CAT) activity augmented after 6 and 24 h of exposure and GSH content increased after 24 h of WSFG exposure. However, in both the organs, activation of the antioxidant defenses was not enough to prevent oxidative damage since they showed lipid peroxidation (LPO) at one of the experimental times: the liver after 6 h and the gills only after 96 h of exposure to WSFG. This may indicate better adaptation of the liver to longer exposures, starting from 24 h. As the gills are the first organ to be exposed to xenobiotics, the antioxidant defenses were triggered immediately upon exposure to WSFG and were able to prevent the occurrence of LPO during the initial times. PMID:21560013

  6. Brassinosteroids Denigrate the Seasonal Stress through Antioxidant Defense System in Seedlings of Brassica juncea L.

    OpenAIRE

    Sandeep Kumar; Geetika Sirhindi; Renu Bhardwaj; Manish Kumar

    2014-01-01

    The present work has been undertaken to study the effect of exogenously application of 24-epiBL and 28-homoBL on soluble protein, proline contents and antioxidant defense system of Brassica juncea L. RLM 619 under the influence of seasonal stress. It was observed that 24-epiBL and 28-homoBL treatment enhance the soluble protein, dry weight and shoot length of B. juncea seedlings under seasonal stress. If seeds treated with the different concentrations (10-6, 10-8 and 10-10 M) of 24-epiBL and ...

  7. BRASSINOSTEROIDS DENIGRATE THE SEASONAL STRESS THROUGH ANTIOXIDANT DEFENSE SYSTEM IN SEEDLINGS OF BRASSICA JUNCEA L

    OpenAIRE

    Kumar, Sandeep; Sirhindi, Geetika; Bhardwaj, Renu; Kumar, Manish

    2014-01-01

    The present work has been undertaken to study the effect of exogenously application of 24-epiBL and 28-homoBL on soluble protein, proline contents and antioxidant defense system of Brassica juncea L. RLM 619 under the influence of seasonal stress. It was observed that 24-epiBL and 28-homoBL treatment enhance the soluble protein, dry weight and shoot length of B. juncea seedlings under seasonal stress. If seeds treated with the different concentrations (10 -6, 10 -8 and 10 -10 M) of 24-epiBL a...

  8. Mechanisms of defense waste glass dissolution

    International Nuclear Information System (INIS)

    The mechanisms that control the release of components of nuclear waste glasses into aqueous environments and the rates of such release depend to a large extent on the contact time between the glass and a particular volume of water. At short contact times the release of leach products does not significantly affect the reactivity of the water toward the glass, while at long contact times, such as those expected in repository environments, saturation of the aqueous medium and the formation of new solid phases are very important. The development of a methodology based on the analysis of flow test data to identify controlling leach mechanisms under slow-flow as well as rapid-flow conditions is described. Not only are the leach mechanisms and leach rates strongly dependent on contact time, but the effects of glass composition, leachant composition, and temperature on the leaching process are as well. Accordingly, test data and models obtained for long contact times are most useful for developing predictions of glass durability under repository conditions, while the applicability of short-term test data is limited

  9. Responses of antioxidant defense system of Lespedeza davurica to enhanced UV-B radiation

    International Nuclear Information System (INIS)

    The objective of this study was to investigate the effects of different UV-B radiation intensity (CK, T1, T2) on antioxidant defense system and other related indicators of Lespedeza davurica (Laxm.) Schindl. Malonaldehyde (MDA), ascorbic acid (AsA) and carotenoid (Car) contents, as well as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities of leaves from Lespedeza davurica under different UV-B radiation intensity were investigated. Samples were collected once every three days. The UV-B treatment was continued 15 days. Result indicated that SOD and POD activities decreased, APX and POD activities increased with UV-B radiation enhanced during the whole treatment time. SOD, POD and CAT activities decreased with UV-B radiation intensity increasing. APX activity increased during the first 9-day treatment with radiation intensity increasing then decreased with radiation intensity increasing. UV-B radiation increased AsA content, decreased Car content. Both AsA and Car contents decreased with radiation intensity increasing when compared with control. O2- and MDA increased with radiation intensity increasing. All other tested indicators increased except SOD and POD activity as well as AsA content decreased after UV-B radiation treatment. Comprehensive evaluation of subordinate function showed that UV-B radiation reduced the antioxidant capacity of Lespedeza davurica, and the antioxidant capacity decreased with UV-B radiation intensity increasing. (author)

  10. Involvement of Protein Phosphorylation in Water Stress-induced Antioxidant Defense in Maize Leaves

    Institute of Scientific and Technical Information of China (English)

    Shu-cheng Xu; Hai-dong Ding; Feng-xia Su; A-ying Zhang; Ming-yi Jiang

    2009-01-01

    Using pharmacological and biochemical approaches, the role of protein phosphorylation and the interrelationship between water stress-enhanced kinase activity, antioxidant enzyme activity, hydrogen peroxide (H2O2) accumulation and endogenous abscisic acid in maize (Zea mays L.) leaves were investigated. Water-stress upregulated the activities of total protein phosphorylation and Ca2+ -dependent protein kinase, and the upregulation was blocked in abscisic acid-deficient vp5 mutant. Furthermore, pretreatments with a nicotinamide adenine dinucleotide phosphate oxidase inhibitor and a scavenger of H2O2 significantly reduced the increased activities of total protein kinase and Ca2+-dependent protein kinase in maize leaves exposed to water stress. Pretreatments with different protein kinase inhibitors also reduced the water stress-induced H2O2 production and the water stress-enhanced activities of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase. The data suggest that protein phosphorylation and H2O2 generation are required for water stress-induced antioxidant defense in maize leaves and that crosstalk between protein phosphorylation and H2O2 generation may occur.

  11. Influence of fasting on muscle composition and antioxidant defenses of market-size Sparus macrocephalus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The study was conducted to investigate fasting effects on flesh composition and antioxidant defenses of market-size Sparus macrocephalus. Two hundred fish (main initial weight 580 g) were divided into two groups (control and fasted) and reared in 6 cages. After two weeks of adaptation, group Ⅰ fasted for 28 d; group Ⅱ was fed normally as a control. In 3, 7, 14, 21 and 28 d,6 fish per group were sampled for proximate flesh composition, liver antioxidant enzyme activities and malondialdehyde flesh content analyses. In fasted fish, the reduction of lipid content in muscle occurred after day 3, and, compared to controls, the content of protein decreased from day 14, the activities of liver antioxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) increased from day 3, and flesh malondialdehyde levels increased from day 21. Flesh fat reduction shows that fasting may be used as a technique to reduce flesh lipid content in Sparus macrocephalus. However, considering flesh protein loss and the subsequent oxidative stress, the fasting technique should be used with precautions.

  12. Colors and Some Morphological Traits as Defensive Mechanisms in Anurans

    Directory of Open Access Journals (Sweden)

    Luís Felipe Toledo

    2009-01-01

    Full Text Available Anurans may be brightly colored or completely cryptic. Generally, in the former situation, we are dealing with aposematism, and the latter is an example of camouflage. However, these are only simple views of what such colorations really mean and which defensive strategy is implied. For instance, a brightly colored frog may be part of a mimicry ring, which could be either Batesian, Müllerian, or Browerian. These are only examples of the diversity of color-usage systems as defensive strategies. Unfortunately, reports on the use of colors as defensive mechanisms are widespread in the available literature, and the possible functions are rarely mentioned. Therefore, we reviewed the literature and added new data to this subject. Then, we the use of colors (as defensive mechanism into categories. Mimicry was divided into the subcategories camouflage, homotypy, and nondeceitful homotypy, and these groups were also subcategorized. Dissuasive coloration was divided into behavioral display of colors, polymorphism, and polyphenism. Aposematism was treated apart, but aposematic colorations may be present in other defensive strategies. Finally, we propose functions and forms of evolution for some color systems in post-metamorphic anurans and hope that this review can be the basis for future research, even on other animal groups.

  13. System defense mechanisms in nuclear power generation control computers

    International Nuclear Information System (INIS)

    Dual-redundant computers are used to control and monitor the production of power from Ontario Hydro's nuclear power reactors. Each computer must have the capability of monitoring its own performance and detecting faults. Upon fault detection, each computer must initiate corrective responses to ensure the integrity of critical control functions. This paper reviews those features the authors have termed system defense mechanisms

  14. EFFECTS OF METALS ON PULMONARY DEFENSE MECHANISMS AGAINST INFECTIOUS DISEASE

    Science.gov (United States)

    The respiratory system under normal conditions has the ability to maintain sterility of the deep lung even when large numbers of microbes are deposited under laboratory conditions. A number of mechanisms have been shown to be responsible for this defense of the lung, namely, mech...

  15. The Venturia Apple Pathosystem: Pathogenicity Mechanisms and Plant Defense Responses

    OpenAIRE

    Gopaljee Jha; Karnika Thakur; Priyanka Thakur

    2009-01-01

    Venturia inaequalis is the causal agent of apple scab, a devastating disease of apple. We outline several unique features of this pathogen which are useful for molecular genetics studies intended to understand plant-pathogen interactions. The pathogenicity mechanisms of the pathogen and overview of apple defense responses, monogenic and polygenic resistance, and their utilization in scab resistance breeding programs are also reviewed.

  16. Grooming Behavior as a Mechanism of Insect Disease Defense

    OpenAIRE

    Forschler, Brian T.; Marianna Zhukovskaya; Aya Yanagawa

    2013-01-01

    Grooming is a well-recognized, multipurpose, behavior in arthropods and vertebrates. In this paper, we review the literature to highlight the physical function, neurophysiological mechanisms, and role that grooming plays in insect defense against pathogenic infection. The intricate relationships between the physical, neurological and immunological mechanisms of grooming are discussed to illustrate the importance of this behavior when examining the ecology of insect-pathogen interactions.

  17. Alterations of pulmonary defense mechanisms by protein depletion diet.

    OpenAIRE

    Jakab, G J; Warr, G A; Astry, C L

    1981-01-01

    Pulmonary defense mechanisms were quantitated in mice that were fed a protein-free diet (PFD) for periods of 2 and 3 weeks. Despite the severe weight loss and emaciation induced by the diet, the bactericidal mechanisms in their lungs were preserved against aerogenic challenges with staphylococcus aureus, Proteus mirabilis, and Listeria monocytogenes. Phagocytic assays of alveolar macrophages that were retrieved by pulmonary lavage from PFD-fed animals showed a decrease in Fc receptor-mediated...

  18. The circadian clock regulates rhythmic activation of the NRF2/glutathione-mediated antioxidant defense pathway to modulate pulmonary fibrosis

    Science.gov (United States)

    Pekovic-Vaughan, Vanja; Gibbs, Julie; Yoshitane, Hikari; Yang, Nan; Pathiranage, Dharshika; Guo, Baoqiang; Sagami, Aya; Taguchi, Keiko; Bechtold, David; Loudon, Andrew; Yamamoto, Masayuki; Chan, Jefferson; van der Horst, Gijsbertus T.J.; Fukada, Yoshitaka; Meng, Qing-Jun

    2014-01-01

    The disruption of the NRF2 (nuclear factor erythroid-derived 2-like 2)/glutathione-mediated antioxidant defense pathway is a critical step in the pathogenesis of several chronic pulmonary diseases and cancer. While the mechanism of NRF2 activation upon oxidative stress has been widely investigated, little is known about the endogenous signals that regulate the NRF2 pathway in lung physiology and pathology. Here we show that an E-box-mediated circadian rhythm of NRF2 protein is essential in regulating the rhythmic expression of antioxidant genes involved in glutathione redox homeostasis in the mouse lung. Using an in vivo bleomycin-induced lung fibrosis model, we reveal a clock “gated” pulmonary response to oxidative injury, with a more severe fibrotic effect when bleomycin was applied at a circadian nadir in NRF2 levels. Timed administration of sulforaphane, an NRF2 activator, significantly blocked this phenotype. Moreover, in the lungs of the arrhythmic ClockΔ19 mice, the levels of NRF2 and the reduced glutathione are constitutively low, associated with increased protein oxidative damage and a spontaneous fibrotic-like pulmonary phenotype. Our findings reveal a pivotal role for the circadian control of the NRF2/glutathione pathway in combating oxidative/fibrotic lung damage, which might prompt new chronotherapeutic strategies for the treatment of human lung diseases, including idiopathic pulmonary fibrosis. PMID:24637114

  19. Endogenous antioxidant defense induction by melon superoxide dismutase reduces cardiac hypertrophy in spontaneously hypertensive rats.

    Science.gov (United States)

    Carillon, Julie; Rugale, Caroline; Rouanet, Jean-Max; Cristol, Jean-Paul; Lacan, Dominique; Jover, Bernard

    2014-08-01

    We assessed the influence of SODB, a melon superoxide dismutase (SOD), on left ventricular (LV) hypertrophy in SHR. SODB (4 or 40U SOD) was given orally for 4 or 28 days to SHR. For each treatment period, LV weight index (LVWI) and cardiomyocytes size were measured. SOD, glutathione peroxidase (GPx) and catalase expressions, and LV production and presence of superoxide anion were determined. Pro-inflammatory markers were also measured. SODB reduced LVWI and cardiomyocytes size after 4 or 28 days. Cardiac SOD and GPx increased by 30-40% with SODB. The presence but not production of superoxide anion was significantly reduced by SODB. No effect of SODB was detected on inflammatory status in any group. The beneficial effect of SODB on cardiac hypertrophy seems to be related to the stimulation of endogenous antioxidant defense, suggesting that SODB may be of interest as a dietary supplementation during conventional antihypertensive therapy. PMID:24601674

  20. Antioxidative defense enzymes in placenta protect placenta and fetus in inherited thrombophilia from hydrogen peroxide

    OpenAIRE

    Jelena Bogdanovic Pristov; Ivan Spasojevic; Željko Mikovic; Vesna Mandic; Nikola Cerovic; Mihajlo Spasic

    2009-01-01

    Our aim was to investigate the activities of antioxidative defense enzymes in the placenta, fetal blood and amnion fluid in inherited thrombophilia. Thrombophilia was associated with nearly threefold increase of activity (p < 0.001) of the placental catalase (81.1 ± 20.6 U/mg of proteins in controls and 270.0 ± 69.9 U/mg in thrombophilic subjects), glutathione (GSH) peroxidase (C: 20.2 ± 10.1 U/mg; T: 60.0 ± 15.5 U/mg), and GSH reductase (C: 28.9 ± 5.6 U/mg; T: 72.7 ± 23.0 U/mg). The placenta...

  1. Methyl jasmonate regulates antioxidant defense and suppresses arsenic uptake in Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Muhammad A Farooq

    2016-04-01

    Full Text Available Methyl jasmonate (MJ is an important plant growth regulator, involved in plant defense against abiotic stresses, however its possible function in response to metal stress is poorly understood. In the present study, the effect of MJ on physiological and biochemical changes of the plants exposed to arsenic (As stress were investigated in two Brassica napus L. cultivars (ZS 758 – a black seed type, and Zheda 622 – a yellow seed type. The As treatment at 200 µM was more phytotoxic, however its combined application with MJ resulted in significant increase in leaf chlorophyll fluorescence, biomass production and reduced malondialdehyde content compared with As stressed plants. The application of MJ minimized the oxidative stress, as revealed via a lower level of reactive oxygen species (ROS synthesis (H2O2 and OH- in leaves and the maintenance of high redox states of glutathione and ascorbate. Enhanced enzymatic activities and gene expression of important antioxidants (SOD, APX, CAT, POD, secondary metabolites (PAL, PPO, CAD and induction of lypoxygenase gene suggest that MJ plays an effective role in the regulation of multiple transcriptional pathways which were involved in oxidative stress responses. The content of As was higher in yellow seeded plants (cv. Zheda 622 as compared to black seeded plants (ZS 758. The application of MJ significantly reduced the As content in leaves and roots of both cultivars. Findings of the present study reveal that MJ improves ROS scavenging through enhanced antioxidant defense system, secondary metabolite and reduced As contents in both the cultivars.

  2. Brassinosteroids Denigrate the Seasonal Stress through Antioxidant Defense System in Seedlings of Brassica juncea L.

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2014-05-01

    Full Text Available The present work has been undertaken to study the effect of exogenously application of 24-epiBL and 28-homoBL on soluble protein, proline contents and antioxidant defense system of Brassica juncea L. RLM 619 under the influence of seasonal stress. It was observed that 24-epiBL and 28-homoBL treatment enhance the soluble protein, dry weight and shoot length of B. juncea seedlings under seasonal stress. If seeds treated with the different concentrations (10-6, 10-8 and 10-10 M of 24-epiBL and 28-homoBL revealed batter growth, protein and proline contents as compare to untreated seedlings. Similarly the activities of antioxidant enzymes SOD, CAT, APOX, DHAR, PPO and Auxinases were enhanced by the application of different concentration of both brassinosteroids, whereas MDA content was decrease with both brassinosteroids treatments. Then we have concluded that both brassinolides have the seasonal stress ameliorative properties in B. juncea seedlings grown under the influence of seasonal stress. This study culminates to the role of brassinolides as an anti-stress property for protection of plant from various types of stresses.

  3. Imbalanced free radicals and antioxidant defense systems in schizophrenia: A comparative study

    Institute of Scientific and Technical Information of China (English)

    LI Hui-chun; CHEN Qiao-zhen; MA Ying; ZHOU Jun-fu

    2006-01-01

    Objective: To examine changes of blood oxidative-antiovidative level in schizophrenic patients and its relationship with clinical symptoms. Methods: Forty-six Chinese patients met DSM-Ⅳ (Diagnostic and Statistical Manual of Mental Disorders-Ⅳ) criteria for schizophrenia and fifty age- and sex-matched healthy controls were enrolled in the present study. Baseline psychiatric symptom severity was assessed with brief psychiatric rating scale, positive and negative syndrome scale on the blood draw day. Fresh blood samples were collected to measure levels of nitric oxide and lipid peroxide in plasma as well as activities of superoxide dismutase, catalase and glutathione peroxidase in red blood cells by spectrophotometric assays simultaneously. Results:Comparison of the biochemical parameters indicated that the level of nitric oxide and lipid peroxide increased in patient group,which represented a positive correlation with positive scale scores; while the activities of three critical enzymes decreased and showed a negative linear correlation. Conclusion: This study showed that there are dysregulation of free radical metabolism and poor activities of the antioxidant defense systems in schizophrenic patients. Excess free radicals formation may play a critical role in the etiology of schizophrenia. Using antioxidants might be an effective therapeutic approach to partially alleviate or prevent the symptoms of schizophrenia.

  4. The role of earthworm defense mechanisms in ecotoxicity studies

    Directory of Open Access Journals (Sweden)

    R Roubalová

    2015-08-01

    Full Text Available Earthworms are important soil organisms that affect the soil structure by influencing organic and inorganic matter breakdown. Earthworms are in permanent contact with soil particles via their permeable skin and digestive tract and are thus strongly affected by pollutants present in the soil. Earthworms often live in very hostile environments with an abundant microflora and therefore have developed very potent defense mechanisms. These mechanisms have been described to be influenced by various types of organic and inorganic pollutants and also by the nanoparticles that reach the soil system. Reduced abilities of earthworms to protect themselves against pathogenic microorganisms result in lower reproduction rates and increased mortality. In this review, a summary of the up-to-date data describing the effects of contaminants on the natural defense barriers and immune system of earthworms is presented.

  5. Wireless Security Threats, Vulnerabilities and Their Defense Mechanisms

    Directory of Open Access Journals (Sweden)

    Ankur Bawiskar

    2013-01-01

    Full Text Available In today’s world means of communications has changed rapidly and the main focus is on wireless communications. Communication in wireless mode has many threats. This paper discusses a brief overview of various threats to wireless networks at various layers and also presents a survey of the defense mechanisms. The main aim is to discuss attacks on MANET and their defense mechanisms. Communication in wireless mode is more challenging as compared to wired mode because of dynamically changing network topology. Wireless networks are mostly used in military applications and commercial applications. This paper also discusses internal threats and external threats. It also gives an overview of routing protocols being used in wireless networks and various attacks that take place against these routing protocols and their counter measures.

  6. The Venturia Apple Pathosystem: Pathogenicity Mechanisms and Plant Defense Responses

    Directory of Open Access Journals (Sweden)

    Gopaljee Jha

    2009-01-01

    Full Text Available Venturia inaequalis is the causal agent of apple scab, a devastating disease of apple. We outline several unique features of this pathogen which are useful for molecular genetics studies intended to understand plant-pathogen interactions. The pathogenicity mechanisms of the pathogen and overview of apple defense responses, monogenic and polygenic resistance, and their utilization in scab resistance breeding programs are also reviewed.

  7. Plant innate immunity: An updated insight into defense mechanism

    Indian Academy of Sciences (India)

    Mehanathan Muthamilarasan; Manoj Prasad

    2013-06-01

    Plants are invaded by an array of pathogens of which only a few succeed in causing disease. The attack by others is countered by a sophisticated immune system possessed by the plants. The plant immune system is broadly divided into two, viz. microbial-associated molecular-patterns-triggered immunity (MTI) and effector-triggered immunity (ETI). MTI confers basal resistance, while ETI confers durable resistance, often resulting in hypersensitive response. Plants also possess systemic acquired resistance (SAR), which provides long-term defense against a broad-spectrum of pathogens. Salicylic-acid-mediated systemic acquired immunity provokes the defense response throughout the plant system during pathogen infection at a particular site. Trans-generational immune priming allows the plant to heritably shield their progeny towards pathogens previously encountered. Plants circumvent the viral infection through RNA interference phenomena by utilizing small RNAs. This review summarizes the molecular mechanisms of plant immune system, and the latest breakthroughs reported in plant defense. We discuss the plant–pathogen interactions and integrated defense responses in the context of presenting an integral understanding in plant molecular immunity.

  8. Response of enzymatic and non-enzymatic antioxidant defense systems of Polygonum hydropiper to Mn stress

    Institute of Scientific and Technical Information of China (English)

    杨贤均; 邓冬梅; 刘可慧; 于方明

    2016-01-01

    The response of enzyme and non-enzymatic antioxidants of Mn hyperaccumuator,Polygonum hydropiper (P. hydropiper), to Mn stress was studied using hydroponics culture experiments to explore the mechanism of Mn tolerance in this species. Results showed that both chlorophyll and carotenoid contents significantly (p<0.05) decreased with increasing Mn treatment levels (0, 0.5, 1, 2, 4, and 8 mg/L) in hydroponics. The concentrations of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in the root and shoot ofP. hydropiper were accumulated under Mn stress. Meanwhile, the anti-oxidative functions of several important enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) in plants were stimulated by Mn spike in leaves and roots, especially at low Mn stress; while sulfhydryl group (—SH) and glutathion (GSH) were likely involved in Mn detoxification ofP. hydropiper under high Mn stress.

  9. A Systematic Review of Oxidative Stress and Safety of Antioxidants in Diabetes: Focus on Islets and Their Defense

    Directory of Open Access Journals (Sweden)

    Udayakumar Karunakaran

    2013-04-01

    Full Text Available A growing body of evidence suggests that hyperglycemia-induced oxidative stress plays an important role in diabetic complications, especially β-cell dysfunction and failure. Under physiological conditions, reactive oxygen species serve as second messengers that facilitate signal transduction and gene expression in pancreatic β-cells. However, under pathological conditions, an imbalance in redox homeostasis leads to aberrant tissue damage and β-cell death due to a lack of antioxidant defense systems. Taking into account the vulnerability of islets to oxidative damage, induction of endogenous antioxidant enzymes or exogenous antioxidant administration has been proposed as a way to protect β-cells against diabetic insults. Here, we consider recent insights into how the redox response becomes deregulated under diabetic conditions, as well as the therapeutic benefits of antioxidants, which may provide clues for developing strategies aimed at the treatment or prevention of diabetes associated with β-cell failure.

  10. Review of the Book “Defense Mechanisms. Coping Strategies. Self-Regulation”

    Directory of Open Access Journals (Sweden)

    Stoil Mavrodiev

    2012-10-01

    Full Text Available This book deals with coping strategies and defense mechanisms as two kinds of self-regulation of human behaviour. The defense mechanisms are described with some examples of fiction books.

  11. [Peculiarities of antioxidant defense system in erythroid cells and tissues of pigs under action of chromium chloride].

    Science.gov (United States)

    Iskra, R Ia; Vlizlo, V V

    2013-01-01

    The influence of CrCI3 in the amount of 400 mg Cr/kg of feed on antioxidant defense in populations of erythrocytes, erythroid bone marrow cells and tissues of pigs was studied. The increasing of the antioxidant defense of swine organism, as evidenced by the increase in superoxide dismutase and glutathione peroxidase activity in the fractions of "young" erythrocytes, was shown. Superoxide dismutase activity decreases, while glutathione and catalase activity increases in the erythroid cells of the bone marrow after of CrCl3 action. Oxidative processes are intensified in the liver of pigs of the experimental group, in contrast to other tissues, leading to the increase of content of TBARS-products, growth of superoxide dismutase activity and reduction of glutathione peroxidase activity. At the same time, the action of CrCl3 in other tissues activates antioxidant system, including the kidneys, lungs and myocardium, increases superoxide dismutase activity, and catalase activity in the spleen and kidneys. A decrease of content of TBARS-products and reduction of superoxide dismutase activity, as well as the increase of katalase activity and reduction of glutathione content were discovered in the skeletal muscles of pigs of the experimental group. As a result of research it is suggested to add CrCl3 to the diet of pigs to enhance antioxidant defense during their intensive growth. PMID:23940874

  12. The strawberry plant defense mechanism: a molecular review.

    Science.gov (United States)

    Amil-Ruiz, Francisco; Blanco-Portales, Rosario; Muñoz-Blanco, Juan; Caballero, José L

    2011-11-01

    Strawberry, a small fruit crop of great importance throughout the world, has been considered a model plant system for Rosaceae, and is susceptible to a large variety of phytopathogenic organisms. Most components and mechanisms of the strawberry defense network remain poorly understood. However, from current knowledge, it seems clear that the ability of a strawberry plant to respond efficiently to pathogens relies first on the physiological status of injured tissue (pre-formed mechanisms of defense) and secondly on the general ability to recognize and identify the invaders by surface plant receptors, followed by a broad range of induced mechanisms, which include cell wall reinforcement, production of reactive oxygen species, phytoalexin generation and pathogenesis-related protein accumulation. Dissection of these physiological responses at a molecular level will provide valuable information to improve future breeding strategies for new strawberry varieties and to engineer strawberry plants for durable and broad-spectrum disease resistance. In turn, this will lead to a reduction in use of chemicals and in environmental risks. Advances in the understanding of the molecular interplay between plant (mainly those considered model systems) and various classes of microbial pathogens have been made in the last two decades. However, major progress in the genetics and molecular biology of strawberry is still needed to uncover fully the way in which this elaborate plant innate immune system works. These fundamental insights will provide a conceptual framework for rational human intervention through new strawberry research approaches. In this review, we will provide a comprehensive overview and discuss recent advances in molecular research on strawberry defense mechanisms against pathogens. PMID:21984602

  13. Effect of phosphogypsum on growth, physiology, and the antioxidative defense system in sunflower seedlings.

    Science.gov (United States)

    Elloumi, Nada; Zouari, Mohamed; Chaari, Leila; Abdallah, Ferjani Ben; Woodward, Steve; Kallel, Monem

    2015-10-01

    Phosphogypsum (PG) is the solid waste product of phosphate fertilizer production and is characterized by high concentrations of salts, heavy metals, and certain natural radionuclides. The work reported in this paper examined the influence of PG amendment on soil physicochemical proprieties, along with its potential impact on several physiological traits of sunflower seedlings grown under controlled conditions. Sunflower seedlings were grown on agricultural soil substrates amended with PG at rates of 0, 2.5, and 5 %. The pH of the soil decreased but electrical conductivity and organic matter, calcium, phosphorus, sodium, and heavy metal contents increased in proportion to PG concentration. In contrast, no variations were observed in magnesium content and small increases were recorded in potassium content. The effects of PG on sunflower growth, leaf chlorophyll content, nutritional status, osmotic regulator content, heavy metal accumulation, and antioxidative enzymes were investigated. Concentrations of trace elements in sunflower seedlings grown in PG-amended soil were considerably lower than ranges considered phytotoxic for vascular plants. The 5 % PG dose inhibited shoot extension and accumulation of biomass and caused a decline in total protein content. However, chlorophyll, lipid peroxidation, proline and sugar contents, and activities of antioxidant enzymes such as superoxide dismutase and catalase increased. Collectively, these results strongly support the hypothesis that enzymatic antioxidation capacity is an important mechanism in tolerance of PG salinity in sunflower seedlings. PMID:25994270

  14. Cadmium tolerance and antioxidative defenses in hairy roots of the cadmium hyperaccumulator, Thlaspi caerulescens.

    Science.gov (United States)

    Boominathan, Rengasamy; Doran, Pauline M

    2003-07-20

    Plant species capable of hyperaccumulating heavy metals are of considerable interest for phytoremediation and phytomining. This work aims to identify the role of antioxidative metabolism in heavy metal tolerance in the Cd hyperaccumulator, Thlaspi caerulescens. Hairy roots of T. caerulescens and the non-hyperaccumulator, Nicotiana tabacum (tobacco), were used to test the effects of high Cd environments. In the absence of Cd, endogenous activities of catalase were two to three orders of magnitude higher in T. caerulescens than in N. tabacum. T. caerulescens roots also contained significantly higher endogenous superoxide dismutase activity and glutathione concentrations. Exposure to 20 ppm (178 microM) Cd prevented growth of N. tabacum roots and increased hydrogen peroxide (H(2)O(2)) levels by a factor of five relative to cultures without Cd. In contrast, growth was maintained in T. caerulescens, and H(2)O(2) concentrations were controlled to low, nontoxic levels in association with a strong catalase induction response. Treatment of roots with the glutathione synthesis inhibitor, buthionine sulfoximine (BSO), exacerbated H(2)O(2) accumulation in Cd-treated N. tabacum, but had a relatively minor effect on H(2)O(2) levels and did not reduce Cd tolerance in T. caerulescens. Lipid peroxidation was increased by Cd treatment in both the hyperaccumulator and non-hyperaccumulator roots. This work demonstrates that metal-induced oxidative stress occurs in hyperaccumulator tissues even though growth is unaffected by the presence of heavy metals. It also suggests that superior antioxidative defenses, particularly catalase activity, may play an important role in the hyperaccumulator phenotype of T. caerulescens. PMID:12768621

  15. Effects of Roundup Transorb on fish: hematology, antioxidant defenses and acetylcholinesterase activity.

    Science.gov (United States)

    Modesto, Kathya A; Martinez, Cláudia B R

    2010-10-01

    Roundup Transorb(RDT) is a glyphosate-based herbicide containing a mixture of surfactants. The objective of this work was to evaluate the effects of this herbicide on the Neotropical fish Prochilodus lineatus. Juvenile fish were acutely exposed (6, 24 and 96 h) to 1 mg L(-1) of RDT (RDT 1), 5 mg L(-1) of RDT (RDT 5) or only water (control) and blood samples for hematological analysis, liver for antioxidants analysis, and brain and muscle for acetylcholinesterase (AChE) determination, were collected. RDT effects were more evident in fish exposed to the higher concentration of the herbicide. Hematologic alterations appeared only after 96 h exposure, when fish showed an increase in the hematocrit and in the number of both red and white blood cells. After 6h exposure fish showed a transient reduction in superoxide dismutase and catalase activity. RDT also inhibited glutathione-S-transferase, after 6 and 24h of exposure. The reduction in these enzymes is probably related to the occurrence of lipid peroxidation (LPO) in fish exposed to the herbicide for 6h. LPO returned to control levels after 24 and 96 h exposure to RDT, when fish showed an increased activity of glutathione peroxidase. The content of reduced glutathione also increased after 96 h exposure. Thus, after 24 and 96 h the antioxidant defenses were apparently enough to combat ROS, preventing the occurrence of oxidative damage. The exposure to RDT for 96 h led to an inhibition of AChE in brain and muscle at rates which may not be considered a life-threatening situation. PMID:20684975

  16. Nitric Oxide Reduces Hydrogen Peroxide Accumulation Involved in Water Stress-induced Subcellular Anti-oxidant Defense in Maize Plants

    Institute of Scientific and Technical Information of China (English)

    Jianrong Sang; Mingyi Jiang; Fan Lin; Shucheng Xu; Aying Zhang; Mingpu Tan

    2008-01-01

    Nitric oxide (NO) Is a bioactive molecule involved in many biological events, and has been reported as pro-oxidant as well as anti-oxidant in plants. In the present study, the sources of NO production under water stress, the role of NO in water stress-induced hydrogen peroxide (H2O2) accumulation and subcellular activities of anti-oxidant enzymes in leaves of maize (Zea mays L.) plants were investigated. Water stress Induced defense increases in the generation of NO In maize mesphyll cells and the activity of nitric oxide synthase (NOS) in the cytosolic and microsomal fractions of maize leaves. Water stress-induced defense increases in the production of NO were blocked by pretreatments with Inhibitors of NOS and nitrate reductase (NR), suggesting that NO is produced from NOS and NR in leaves of maize plants exposed to water stress. Water stress also induced increases in the activities of the chloroplastic and cytosolic anti-oxidant enzymes superoxide dismutase (SOD), ascorbate peroxidass (APX), and glutathione reductase (GR), and the increases in the activities of anti-oxidant enzymes were reduced by pretreatments with inhibitors of NOS and NR. Exogenous NO increases the activities of water stress-induced subcellular anti-oxidant enzymes, which decreases accumulation of H2O2. Our results suggest that NOS and NR are involved in water strese-induced NO production and NOS is the major source of NO. The potential ability of NO to scavenge H2O2 is, at least in part, due to the induction of a subcellular anti-oxidant defense.

  17. Purple potato (Solanum tuberosum L.) anthocyanins attenuate alcohol-induced hepatic injury by enhancing antioxidant defense.

    Science.gov (United States)

    Jiang, Zhihui; Chen, Chen; Wang, Jian; Xie, Wenyan; Wang, Meng; Li, Xinsheng; Zhang, Xiaoying

    2016-01-01

    Alcoholic liver disease (ALD) is a serious and challenging health issue. In the past decade, natural components possessing hepatoprotective properties have gained more attention for ALD intervention. In this study, the phytochemical components of anthocyanins from purple potato were assessed using UPLC-MS/MS, and the hepatoprotective effects of purple potato anthocyanins (PPAs) were investigated in the ALD mouse model. Serum and liver biochemical parameters were determined, along with histopathological changes in liver tissue. In addition, the major contributors to alcohol-induced oxidative stress were assessed. The results indicated that the levels of aspartate transaminase and alanine transaminase were lower in the serum of the PPA-treated group than the alcohol-treated group. PPAs significantly inhibited the reduction of total cholesterol and triglycerides. Higher levels of superoxide dismutase and reduced glutathione enzymes as well as a reduction in the formation of malondialdehyde occurred in mice fed with PPAs. In addition, PPAs protected against increased alcohol-induced levels and activity of cytochrome P450 2E1 (CYP2E1), which demonstrates the effects of PPAs against alcohol-induced oxidative stress and liver injury. This study suggests that PPAs could be an effective therapeutic agent in alcohol-induced liver injuries by inhibiting CYP2E1 expression and thereby strengthening antioxidant defenses. PMID:26481011

  18. Antioxidative Defense Enzymes in Placenta Protect Placenta and Fetus in Inherited Thrombophilia from Hydrogen Peroxide

    Directory of Open Access Journals (Sweden)

    Jelena Bogdanovic Pristov

    2009-01-01

    Full Text Available Our aim was to investigate the activities of antioxidative defense enzymes in the placenta, fetal blood and amnion fluid in inherited thrombophilia. Thrombophilia was associated with nearly threefold increase of activity (p < 0.001 of the placental catalase (81.1 ± 20.6 U/mg of proteins in controls and 270.0 ± 69.9 U/mg in thrombophilic subjects, glutathione (GSH peroxidase (C: 20.2 ± 10.1 U/mg; T: 60.0 ± 15.5 U/mg, and GSH reductase (C: 28.9 ± 5.6 U/mg; T: 72.7 ± 23.0 U/mg. The placental activities of superoxide dismutating enzymes—MnSOD and CuZnSOD, did not differ in controls and thrombophilia. Likewise, the activities of catalase and SOD in the fetal blood, and the level of ascorbyl radical which represents a marker of oxidative status of amniotic fluid, were similar in controls and thrombophilic subjects. From this we concluded that in thrombophilia, placental tissue is exposed to H2O2-mediated oxidative stress, which could be initiated by pro-thrombic conditions in maternal blood. Increased activity of placental H2O2-removing enzymes protects fetus and mother during pregnancy, but may increase the risk of postpartum thrombosis.

  19. Defense Mechanisms in Adolescence as Predictors of Adult Personality Disorders.

    Science.gov (United States)

    Strandholm, Thea; Kiviruusu, Olli; Karlsson, Linnea; Miettunen, Jouko; Marttunen, Mauri

    2016-05-01

    Our study examines whether defense styles and separate defenses in depressed adolescent outpatients predict adult personality disorders (PDs). We obtained data from consecutive adolescent outpatients who participated in the Adolescent Depression Study at baseline and at the 8-year follow-up (N = 140). Defense styles were divided into mature, neurotic, image-distorting, and immature and a secondary set of analyses were made with separate defenses as predictors of a PD diagnosis. Neurotic, image-distorting, and immature defense styles in adolescence were associated with adulthood PDs. Neurotic defense style associated with cluster B diagnosis and image-distorting defense style associated with cluster A diagnosis. Separate defenses of displacement, isolation, and reaction formation were independent predictors of adult PD diagnosis even after adjusting for PD diagnosis in adolescence. Defense styles and separate defenses predict later PDs and could be used in the focusing of treatment interventions for adolescents. PMID:26894315

  20. Heat-shock response and antioxidant defense during air exposure in Patagonian shallow-water limpets from different climatic habitats

    OpenAIRE

    Pöhlmann, Kevin; Koenigstein, Stefan; Alter, Katharina; Abele, Doris; Held, Christoph

    2011-01-01

    Climate warming involves not only a rise of air temperature means, but also more frequent heat waves in many regions on earth, and is predicted to intensify physiological stress especially in extremely changeable habitats like the intertidal. We investigated the heat-shock response (HSR) and enzymatic antioxidant defense levels of Patagonian shallow-water limpets, adapted to distinct tidal exposure conditions in the sub- and intertidal. Limpets were sampled in the temperate Northern Patagonia...

  1. Defense High-Level Waste Leaching Mechanisms Program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mendel, J.E. (compiler)

    1984-08-01

    The Defense High-Level Waste Leaching Mechanisms Program brought six major US laboratories together for three years of cooperative research. The participants reached a consensus that solubility of the leached glass species, particularly solubility in the altered surface layer, is the dominant factor controlling the leaching behavior of defense waste glass in a system in which the flow of leachant is constrained, as it will be in a deep geologic repository. Also, once the surface of waste glass is contacted by ground water, the kinetics of establishing solubility control are relatively rapid. The concentrations of leached species reach saturation, or steady-state concentrations, within a few months to a year at 70 to 90/sup 0/C. Thus, reaction kinetics, which were the main subject of earlier leaching mechanisms studies, are now shown to assume much less importance. The dominance of solubility means that the leach rate is, in fact, directly proportional to ground water flow rate. Doubling the flow rate doubles the effective leach rate. This relationship is expected to obtain in most, if not all, repository situations.

  2. Defense High-Level Waste Leaching Mechanisms Program. Final report

    International Nuclear Information System (INIS)

    The Defense High-Level Waste Leaching Mechanisms Program brought six major US laboratories together for three years of cooperative research. The participants reached a consensus that solubility of the leached glass species, particularly solubility in the altered surface layer, is the dominant factor controlling the leaching behavior of defense waste glass in a system in which the flow of leachant is constrained, as it will be in a deep geologic repository. Also, once the surface of waste glass is contacted by ground water, the kinetics of establishing solubility control are relatively rapid. The concentrations of leached species reach saturation, or steady-state concentrations, within a few months to a year at 70 to 900C. Thus, reaction kinetics, which were the main subject of earlier leaching mechanisms studies, are now shown to assume much less importance. The dominance of solubility means that the leach rate is, in fact, directly proportional to ground water flow rate. Doubling the flow rate doubles the effective leach rate. This relationship is expected to obtain in most, if not all, repository situations

  3. Photochemistry and photobiology of actinic erythema: defensive and reparative cutaneous mechanisms

    Directory of Open Access Journals (Sweden)

    A.C. Tedesco

    1997-05-01

    Full Text Available Sunlight is part of our everyday life and most people accept it as beneficial to our health. With the advance of our knowledge in cutaneous photochemistry, photobiology and photomedicine over the past four decades, the terrestrial solar radiation has become a concern of dermatologists and is considered to be a major damaging environmental factor for our skin. Most photobiological effects (e.g., sunburn, suntanning, local and systemic immunosuppression, photoaging or dermatoheliosis, skin cancer and precancer, etc. are attributed to ultraviolet radiation (UVR and more particularly to UVB radiation (290-320 nm. UVA radiation (320-400 nm also plays an important role in the induction of erythema by the photosensitized generation of reactive oxygen species (singlet oxygen (1O2, superoxide (O2.- and hydroxyl radicals (.OH that damage DNA and cellular membranes, and promote carcinogenesis and the changes associated with photoaging. Therefore, research efforts have been directed at a better photochemical and photobiological understanding of the so-called sunburn reaction, actinic or solar erythema. To survive the insults of actinic damage, the skin appears to have different intrinsic defensive mechanisms, among which antioxidants (enzymatic and non-enzymatic systems play a pivotal role. In this paper, we will review the basic aspects of the action of UVR on the skin: a photochemical reactions resulting from photon absorption by endogenous chromophores; b the lipid peroxidation phenomenon, and c intrinsic defensive cutaneous mechanisms (antioxidant systems. The last section will cover the inflammatory response including mediator release after cutaneous UVR exposure and adhesion molecule expression

  4. Protective effects of L-arginine on pulmonary oxidative stress and antioxidant defenses during exhaustive exercise in rats

    Institute of Scientific and Technical Information of China (English)

    Wan-teng LIN; Suh-ching YANG; Kung-tung CHEN; Chi-chang HUANG; Ning-yuean LEE

    2005-01-01

    Aim: To assess the effects of L-arginine (L-Arg) supplementation on pulmonary oxidative stress and antioxidant defenses in rats after exhaustive exercise. Methods:Rats were randomly divided into four groups: sedentary control (SC), sedentary control with L-Arg treatment (SC+Arg), exhaustive exercise with control diet (E)and exhaustive exercise with L-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2% L-Arg diet. Rats in groups E and E+Arg underwent an exhaustive running test on a motorized treadmill. Pulmonary oxidative stress indices [xanthine oxidase (XO), myeloperoxidase (MPO), and malondialdehyde (MDA)] and antioxidant defense systems [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione (GSH)] were investigated in this study. Results: L-Arg supplementation significantly reduced exercise-induced elevations of XO and MPO activities in lung. LArg reversed the exercise-induced increase in SOD and GR activities, but increased CAT and GPX activities. L-Arg administration also significantly increased the GSH levels in plasma. Conclusion: L-Arg supplementation can prevent elevations of XO and MPO activities in the lung and favorably influence pulmonary antioxidant defense systems after exhaustive exercise.

  5. Diet supplementation with a specific melon concentrate improves oviduct antioxidant defenses and egg characteristics in laying hens.

    Science.gov (United States)

    Carillon, J; Barbé, F; Barial, S; Saby, M; Sacy, A; Rouanet, J-M

    2016-08-01

    The objectives of this study were to investigate the effects of a specific melon concentrate on oviduct antioxidant defenses and egg characteristics of laying hens.Lohmann Brown hens were assigned to 2 treatment groups (n = 16 in each). One group was supplemented with the melon concentrate (26 mg/kg of feed) during 6 wk. The other group was composed of untreated hens, which served as control. Eggs were collected, weighed (yolk, albumen, shell), and analyzed (Haugh unit and albumen pH relevant for egg freshness) at the end of the supplementation period. Antioxidant status was evaluated in the oviduct measuring antioxidant enzymes by western blotting.This study demonstrated that the melon concentrate could ameliorate egg weight, and particularly yolk contribution to egg weight and egg shell weight. An increase in endogenous antioxidant defenses in the oviduct after this melon concentrate supplementation could explain the better egg characteristics. The improvement of egg quality, due to melon concentrate, may have important economic implications for future breeding programs, particularly if these effects generalize from hens to other poultry species, or even other livestock animal species. PMID:27143774

  6. Paradoxical Roles of Antioxidant Enzymes: Basic Mechanisms and Health Implications.

    Science.gov (United States)

    Lei, Xin Gen; Zhu, Jian-Hong; Cheng, Wen-Hsing; Bao, Yongping; Ho, Ye-Shih; Reddi, Amit R; Holmgren, Arne; Arnér, Elias S J

    2016-01-01

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate "paradoxical" outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of "antioxidant" nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that "paradoxical" roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways. PMID:26681794

  7. Oxidative Stress Is Associated with an Increased Antioxidant Defense in Elderly Subjects: A Multilevel Approach

    Science.gov (United States)

    Flores-Mateo, Gemma; Elosua, Roberto; Rodriguez-Blanco, Teresa; Basora-Gallisà, Josep; Bulló, Mònica; Salas-Salvadó, Jordi; Martínez-González, Miguel Ángel; Estruch, Ramon; Corella, Dolores; Fitó, Montserrat; Fiol, Miquel; Arós, Fernando; Gómez-Gracia, Enrique; Subirana, Isaac; Lapetra, José; Ruiz-Gutiérrez, Valentina; Sáez, Guillermo T.; Covas, Maria-Isabel

    2014-01-01

    Background Studies of associations between plasma GSH-Px activity and cardiovascular risk factors have been done in humans, and contradictory results have been reported. The aim of our study was to assess the association between the scavenger antioxidant enzyme glutathione peroxidase (GSH-Px) activity in plasma and the presence of novel and classical cardiovascular risk factors in elderly patients. Methods We performed a cross-sectional study with baseline data from a subsample of the PREDIMED (PREvención con DIeta MEDiterránea) study in Spain. Participants were 1,060 asymptomatic subjects at high risk for cardiovascular disease (CVD), aged 55 to 80, selected from 8 primary health care centers (PHCCs). We assessed classical CVD risk factors, plasma oxidized low-density lipoproteins (ox-LDL), and glutathione peroxidase (GSH-Px) using multilevel statistical procedures. Results Mean GSH-Px value was 612 U/L (SE: 12 U/L), with variation between PHCCs ranging from 549 to 674 U/L (Variance = 1013.5; P<0.001). Between-participants variability within a PHCC accounted for 89% of the total variation. Both glucose and oxidized LDL were positively associated with GSH-Px activity after adjustment for possible confounder variables (P = 0.03 and P = 0.01, respectively). Conclusion In a population at high cardiovascular risk, a positive linear association was observed between plasma GSH-Px activity and both glucose and ox-LDL levels. The high GSH-Px activity observed when an oxidative stress situation occurred, such as hyperglycemia and lipid oxidative damage, could be interpreted as a healthy defensive response against oxidative injury in our cardiovascular risk population. PMID:25269026

  8. Zinc Induced Enzymatic Defense Mechanisms in Rhizoctonia Root Rot Infected Clusterbean Seedlings

    Directory of Open Access Journals (Sweden)

    Neha Wadhwa

    2014-01-01

    Full Text Available This investigation was planned to determine the effect of different concentrations of zinc (Zn on biochemical constituents of clusterbean, which play an important role in disease resistance mechanisms. Clusterbean seedlings were grown with 0, 10, or 20 mg Zn kg−1 soil treatments in earthen pots filled with 700 g inoculated soil. Soil was inoculated by pretreatment with 250 mg (wet weight of Rhizoctonia inoculums per pot. A similar set was maintained in uninoculated soil. Root rot incidence decreased to 41 and 27 per cent with 10 and 20 mg Zn kg−1 soil treatments, respectively, as compared to 68 percent at control. Antioxidative enzyme activity (polyphenol oxidase, peroxidase, phenylalanine ammonia lyase, and tyrosine ammonia lyase increased in inoculated seedlings and was increased further by 20 mg Zn kg−1 soil treatment. Antioxidative enzymes play an important role against fungal invasion, as peroxidase is involved in the formation of barrier via lignifications at the site of pathogen penetration. PAL and TAL play a key role in phenylpropanoid metabolism and could perform defense-related functions. Zn acts as a cofactor for these enzymes, so it can be concluded that Zn may be used as a soil-nutritive agent to increase resistance in plants against fungal diseases.

  9. Censorship as an ideological defense mechanism in Democracy and Totalitarianism

    Directory of Open Access Journals (Sweden)

    Daniel Ionică

    2015-12-01

    Full Text Available Censorship is one of the most important defense mechanisms of a State’s ideology or political system. By controlling the information sources, auditors are able to ensure the optimal functioning of the system they defend. Depending on the type of society it originates from, censorship may take various forms, from a minimal role in some cases to a leading role in others. Some forms of censorship existed and still exist regardless of the ideological nature of the regime we are putting into question. This is especially the case for oppressive regimes where censorship and propaganda are vital tools in maintaining political power and legitimacy. While in democratic societies State-based censorship is much rarer, similar measures are more discrete, diverse and may come from other institutions such as social, religious, economic or cultural establishments.

  10. Abscisic acid activates a Ca2+-calmodulin-stimulated protein kinase involved in antioxidant defense in maize leaves

    Institute of Scientific and Technical Information of China (English)

    Shucheng Xu

    2010-01-01

     The role of a calcium-dependent and calmodulin(CaM)stimulated protein kinase in abscisic acid(ABA)-induced antioxidant defense was determined in leaves of maize (Zea mays).In-gel kinase assays showed that treatments with ABA or H2O2 induced the activation of a 49-kDa protein kinase and a 52-kDa protein kinase significantly.Furthermore,we showed that the 52-kDa protein kinase has the characteristics of CaM-stimulating activity and is sensitive to calcium-CaM-dependent protein kinase Ⅱ (CaMK Ⅱ)inhibitor KN-93 or CaM antagonist W-7.Treatments with ABA or H2O2 not only induced the acti vation of the 52-kDa protein kinase,but also enhanced the total activities of the antioxidant enzymes,including catalase,ascorbate peroxidase,glutathione reductase,and superoxide dismutase.Such enhancements were blocked by pretreatment with a CaMK inhibitor and a reactive oxygen species(ROS)inhibitor or scavenger.Pretreatment with the CaMK inhibitor also substantially arrested the ABA-induced H2O2 production.Kinase activity enhancements induced by ABA were attenuated by pretreatment with an ROS inhibitor or scavenger.These results suggest that the 52-kDa CaMK is involved in ABA-induced antioxidant defense and that cross-talk between CaMK and H2O2 plays a pivotal role in ABA signaling.We infer that CaMK acts both upstream and downstream of H2O2,but mainly acts between ABA and H2O2 in ABA-induced antioxidant-defensive signaling.

  11. Ethanol Extract of Ganoderma lucidum Augments Cellular Anti-oxidant Defense through Activation of Nrf2/HO-1

    Directory of Open Access Journals (Sweden)

    Yoo-hwan Lee

    2016-03-01

    Full Text Available Objectives: The mushroom Ganoderma lucidum has been widely used as a traditional herbal medicine for many years. Although several studies have focused on the anti-oxidative activity of this mushroom, the molecular mechanisms underlying its activity have not yet been clearly established. The present study investigated the cytoprotective effect of ethanol extract of Ganoderma lucidum (EGL against oxidative stress (hydrogen peroxide, H2O2 and elucidated the underlying mechanisms in a C2C12 myoblast cell line. Methods: Oxidative stress markers were determined by using the comet assay to measure reactive oxygen species (ROS generation and deoxyribonucleic acid (DNA damage. Cell viability and Western blotting analyses were employed to evaluate the cellular response to EGL and H2O2 in C2C12 cells. Transfection with nuclear factor erythroid 2-related factor 2 (Nrf2-specific small interfering ribonucleic acid (siRNA was conducted to understand the relationship between Nrf2 expression and H2O2-induced growth inhibition. Results: The results showed that EGL effectively inhibited H2O2-induced growth and the generation of ROS. EGL markedly suppressed H2O2-induced comet-like DNA formation and phosphorylation of histone H2AX at serine 139 (p-γH2AX, a widely used marker of DNA damage, suggesting that EGL prevented H2O2-induced DNA damage. Furthermore, the EGL treatment effectively induced the expression of Nrf2, as well as heme oxygenase-1 (HO-1, with parallel phosphorylation and nuclear translocation of Nrf2 in the C2C12 myoblasts. However, zinc protoporphyrin IX, a HO-1 inhibitor, significantly abolished the protective effects of EGL against H2O2-induced accumulation of ROS and reduced cell growth. Notably, transient transfection with Nrf2-specific siRNA attenuated the cytoprotective effects and HO-1 induction by EGL, indicating that EGL induced the expression of HO-1 in an Nrf2-dependent manner. Conclusion: Collectively, these results demonstrate that EGL

  12. For the Pseudoacceptance or Theoretical Bases of one Undescribed Defense Mechanism

    OpenAIRE

    Svetoslav Borisov Karabelyov

    2013-01-01

    Many researchers emphasize that what we know about the defense mechanisms is actually a result of collected clinical data. For somedefense mechanisms like the classical projection, there is not any empirical data proving their existence. There are numerous psychologicalschools, each with its own view of the nature, of the types, of the characteristics and of the effects of the defense mechanisms. There is nota single theory of defense mechanisms. This paper lays the theoretical bases of the p...

  13. Application of radiobiological techniques in studying antioxidant mechanisms: evaluation of their radioprotective, antioxidative and antiviral activities

    International Nuclear Information System (INIS)

    In the medical field, the oxidation phenomenon is the source of several pathologies (diabetes, cystic fibrosis, cancers,...). The natural oxidants are used as food preserving and skin ageing moderators. Several plant extracts with antioxidant activity were studied, this important antioxidant activity is probably due to their richness of compounds: polyphenols, phenolic acids, tocopherols, carotenoids, flavonoids,... Many techniques for evaluation and reactional mechanism study of the antioxidative activity are used. After selection, extraction, fractionation, activity screening, chemical analyses of molecules contained in the best active extracts, biological properties research of isolated redox pharmacophore, we have : - determined the structure of active products by spectroscopy and chromatography; - studied the antioxidative properties by EPR and spin trapping of the obtained extracts and molecules. The results of this first part of our work consists in evaluating the antioxidative degree of a great number of natural active principles, extracted from moroccan plants and pur obtained products. The second part consists in studying the action mechanisms using the LDL labelling (F. M.)

  14. Antioxidant defense system and family environment in adolescents with family history of psychosis

    OpenAIRE

    Gonzalez-Pinto Ana; Martinez-Cengotitabengoa Monica; Arango Celso; Baeza Immaculada; Otero-Cuesta Soraya; Graell-Berna Montserrat; Soutullo César; Leza Juan; Micó Juan

    2012-01-01

    Abstract Background Our objective was to determine antioxidant defence activity in healthy controls (HC) and healthy unaffected second-degree relatives of patients with early onset psychosis (HC-FHP), and to assess its relationship with familiar environment measured using the Family Environment Scale (FES). Methods We included 82 HC and 14 HC-FHP aged between 9 and 17 years. Total antioxidant status, lipid peroxidation, antioxidant enzyme activities and glutathione levels were determined in b...

  15. Differences in the Diunral and Nocturnal Defense Mechanisms of Octopus Bocki (Adams, 1941)

    OpenAIRE

    Valencia, Natalie

    2006-01-01

    Octopuses are known for the advanced behaviors and elaborate displays used in predator avoidance. Although studies have provided anecdotal evidence on the defense mechanisms of these animals, whether these behaviors vary under light and dark conditions is unknown. This study investigated the diurnal and nocturnal predator defense mechanism s of Octopus bocki (Adams, 1941) in Moorea, French Polynesia. Seven behaviors were identified as primary defense mechanisms for protection from fish predat...

  16. Antioxidants of edible mushrooms

    NARCIS (Netherlands)

    Kozarski, Maja; Klaus, Anita; Jakovljevic, Dragica; Todorovic, Nina; Vunduk, Jovana; Petrović, Predrag; Niksic, Miomir; Vrvic, Miroslav M.; Griensven, Van Leo

    2015-01-01

    Oxidative stress caused by an imbalanced metabolism and an excess of reactive oxygen species (ROS) lead to a range of health disorders in humans. Our endogenous antioxidant defense mechanisms and our dietary intake of antioxidants potentially regulate our oxidative homeostasis. Numerous synthetic

  17. Change in Coping and Defense Mechanisms across Adulthood: Longitudinal Findings in a European American Sample

    Science.gov (United States)

    Diehl, Manfred; Chui, Helena; Hay, Elizabeth L.; Lumley, Mark A.; Grühn, Daniel; Labouvie-Vief, Gisela

    2014-01-01

    This study examined longitudinal changes in coping and defense mechanisms in an age- and gender-stratified sample of 392 European American adults. Nonlinear age-related changes were found for the coping mechanisms of sublimation and suppression and the defense mechanisms of intellectualization, doubt, displacement, and regression. The change…

  18. The Comparison of Personality Traits and Defense Mechanisms in Addicts Subjects and Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Hosin Ghamari

    2010-11-01

    Full Text Available Objective: This study was carried out to compare the personality traits and defense mechanisms in Addicts group and healthy subjects. Method: In This descriptive study by cluster method in access, 100 addicted and 100 nonaddicted people were selected. Used questionnaires to assess defense mechanisms are (DSQ40 and NEO. the data were analyzed with using MANOVA. Result: Data analysis revealed a significant difference between addicted subjects and healthy subjects are used in terms of defense styles and terms of NEO. The data analysis revealed that neuroticism and immature and neurotic defense mechanism is more in addict subjects mature defense mechanism and extravertion, oppeness to exprience, agreeableness and conciosiness is more in healthy subjects. Conclution: According to this results it can be concluded that personality traits and defense mechanisms is one of the main ingridient in accession or tensification symptoms of addiction.

  19. Disruption of non-enzymatic antioxidant defense systems in the brain of rats with water-immersion restraint stress

    OpenAIRE

    Ohta, Yoshiji; Yashiro, Koji; Ohashi, Koji; Imai, Yoichiro

    2012-01-01

    We examined whether non-enzymatic antioxidant defense systems are disrupted in the brain of rats with water-immersion restraint stress. When rats were exposed to water-immersion restraint stress for 1.5, 3 or 6 h, the brain had decreased ascorbic acid and reduced glutathione contents and increased lipid peroxide and nitric oxide metabolites contents at 3 h and showed further changes in these components with a reduction of vitamin E content at 6 h. Increased serum levels of stress markers were...

  20. Ego defense mechanisms in Pakistani medical students: a cross sectional analysis

    Directory of Open Access Journals (Sweden)

    Khalid Roha

    2010-01-01

    Full Text Available Abstract Background Ego defense mechanisms (or factors, defined by Freud as unconscious resources used by the ego to reduce conflict between the id and superego, are a reflection of how an individual deals with conflict and stress. This study assesses the prevalence of various ego defense mechanisms employed by medical students of Karachi, which is a group with higher stress levels than the general population. Methods A questionnaire based cross-sectional study was conducted on 682 students from five major medical colleges of Karachi over 4 weeks in November 2006. Ego defense mechanisms were assessed using the Defense Style Questionnaire (DSQ-40 individually and as grouped under Mature, Immature, and Neurotic factors. Results Lower mean scores of Immature defense mechanisms (4.78 were identified than those for Neurotic (5.62 and Mature (5.60 mechanisms among medical students of Karachi. Immature mechanisms were more commonly employed by males whereas females employed more Neurotic mechanisms than males. Neurotic and Immature defenses were significantly more prevalent in first and second year students. Mature mechanisms were significantly higher in students enrolled in Government colleges than Private institutions (p Conclusions Immature defense mechanisms were less commonly employed than Neurotic and Mature mechanisms among medical students of Karachi. The greater employment of Neurotic defenses may reflect greater stress levels than the general population. Employment of these mechanisms was associated with female gender, enrollment in a private medical college, and students enrolled in the first 2 years of medical school.

  1. Herbivore defense responses and associated herbivore defense mechanism as revealed by comparing a resistant wild soybean with a susceptible cultivar

    Directory of Open Access Journals (Sweden)

    Xiaoyi Wang

    2015-12-01

    Full Text Available Plants have evolved sophisticated defense mechanisms against herbivores to help them adapt to the environment. Understanding the defense mechanisms in plants can help us control insects in a more effective manner. In this study, we found that compared with Tianlong 2 (a cultivated soybean with insect susceptibility, ED059 (a wild soybean line with insect resistance contains sharper pubescence tips, as well as lower transcript levels of wound-induced protein kinase (WIPK and salicylic acid-induced protein kinase (SIPK, which are important mitogen-activated protein kinases involved in early defense response to herbivores. The observed lower transcript levels of WIPK and SIPK induced higher levels of jasmonic acid (JA, JA biosynthesis enzymes (AOC3 and some secondary metabolites in ED059. Functional analysis of the KTI1 gene via Agrobacterium-mediated transformation in Arabidopsis thaliana indicated that it plays an important role in herbivore defense in ED059. We further investigated the molecular response of third-instar Helicoverpa armigera (Hübner larvae to Tianlong 2 and ED059. We found apoptotic cells only in the midguts of larvae that fed on ED059. Compared with larvae reared on the susceptible cultivar Tianlong 2, transcript levels of catalase (CAT and glutathione S-transferase (GST were up-regulated, whereas those of CAR, CHSB, and TRY were down-regulated in larvae that fed on the highly resistant variety ED059. We propose that these differences underlie the different herbivore defense responses of ED059 and Tianlong 2.

  2. Heavy Metals and Human Health: Mechanistic Insight into Toxicity and Counter Defense System of Antioxidants

    Science.gov (United States)

    Jan, Arif Tasleem; Azam, Mudsser; Siddiqui, Kehkashan; Ali, Arif; Choi, Inho; Haq, Qazi Mohd. Rizwanul

    2015-01-01

    Heavy metals, which have widespread environmental distribution and originate from natural and anthropogenic sources, are common environmental pollutants. In recent decades, their contamination has increased dramatically because of continuous discharge in sewage and untreated industrial effluents. Because they are non-degradable, they persist in the environment; accordingly, they have received a great deal of attention owing to their potential health and environmental risks. Although the toxic effects of metals depend on the forms and routes of exposure, interruptions of intracellular homeostasis include damage to lipids, proteins, enzymes and DNA via the production of free radicals. Following exposure to heavy metals, their metabolism and subsequent excretion from the body depends on the presence of antioxidants (glutathione, α-tocopherol, ascorbate, etc.) associated with the quenching of free radicals by suspending the activity of enzymes (catalase, peroxidase, and superoxide dismutase). Therefore, this review was written to provide a deep understanding of the mechanisms involved in eliciting their toxicity in order to highlight the necessity for development of strategies to decrease exposure to these metals, as well as to identify substances that contribute significantly to overcome their hazardous effects within the body of living organisms. PMID:26690422

  3. Specificities of defense mechanisms in bipolar affective disorder: relations with symptoms and therapeutic alliance.

    Science.gov (United States)

    Kramer, Ueli; de Roten, Yves; Perry, J Christopher; Despland, Jean-Nicolas

    2009-09-01

    Defense mechanisms as a central notion of psychoanalysis have inspired various levels of interest in research in psychotherapy and psychopathology. Defense specificities have only recently been investigated systematically with regard to several clinical diagnoses, such as affective and personality disorders. For the present study, 30 inpatients diagnosed with Bipolar Affective Disorder I (BD) were interviewed. An observer-rater method, the Defense Mechanisms Rating Scales (DMRS), applied to session-transcripts, of assessment of defenses was used. A matched, nonclinical control group was introduced. Defense specificities in BD encompass a set of 5 immature defenses, of which omnipotence is linked with symptom level. The level of the therapeutic alliance is predicted by mature defenses. These results are discussed with regard to the psychological vulnerability of BD, and treatment implications for psychodynamic psychotherapy with such challenging patients are evoked. PMID:19752647

  4. Defense mechanisms against radiation induced teratogenic damage in mice

    International Nuclear Information System (INIS)

    Experimental studies with mice have established that fetuses at midgestational stage are highly susceptible to malformation at high, but not low, doses of radiation. When DNA damage is produced by a small amount of radiation, it is efficiently eliminated by DNA repair. However, DNA repair is not perfect. There must be defense mechanisms other than DNA repair. In order to elucidate the essential role of p53 gene in apoptotic tissue repair, we compared the incidence of radiation-induced malformations and deaths (deaths after day 10) in wild-type p53 (+/+) mice and null p53 (-/-) mice. For p53 (+/+) mice, an X-ray dose of 2 Gy given at a high dose-rate (450 mGy/min) to fetuses at 9.5 days of gestation was highly lethal and considerably teratogenic whereas it was only slightly lethal but highly teratogenic for p53 (-/-) fetuses. This reciprocal relationship of radiosensitivity to malformations and deaths supports the notion that fetal tissues have a p53 -dependent idguardianln of the tissue that aborts cells bearing radiation-induced teratogenic DNA damage. When an equal dose of 2 Gy given at a 400-fold lower dose-rate (1.2 mGy/min), this dose became not teratogenic for p53 (+/+) fetuses exhibiting p53 -dependent apoptosis, whereas this dose remained teratogenic for p53 (-/-) fetuses unable to carry out apoptosis. Furthermore, when the dose was divided into two equal dose fractions (1+1 Gy) at high dose rate, separated by 24 hours, the incidences of malformations were equal with control level for p53 (+/+), but higher for p53 (-/-) mice. Hence, complete elimination of teratogenic damage from irradiated tissues requires a concerted cooperation of two mechanisms; proficient DNA repair and p53-dependent apoptotic tissue repair

  5. Colors and Some Morphological Traits as Defensive Mechanisms in Anurans

    OpenAIRE

    Luís Felipe Toledo; Célio F. B. Haddad

    2009-01-01

    Anurans may be brightly colored or completely cryptic. Generally, in the former situation, we are dealing with aposematism, and the latter is an example of camouflage. However, these are only simple views of what such colorations really mean and which defensive strategy is implied. For instance, a brightly colored frog may be part of a mimicry ring, which could be either Batesian, Müllerian, or Browerian. These are only examples of the diversity of color-usage systems as defensive strate...

  6. Variations in antioxidant defense during the development of the solitary bee Osmia bicornis

    OpenAIRE

    Dmochowska-Ślęzak, Kamila; Giejdasz, Karol; Fliszkiewicz, Monika; Żółtowska, Krystyna

    2015-01-01

    An efficient antioxidant system is of particular importance for insects whose high metabolic rates promote increased formation of reactive oxygen species (ROS). The amount of ROS can be additionally increased by environmental factors. This study investigates the ability of red mason bees (Osmia bicornis L.) to inactivate free radicals during insect development. Both male and female bees were studied, from the larval to the active imago stage. The activity of four antioxidant enzymes, superoxi...

  7. Calcium Supplementation Improves Na+/K+ Ratio, Antioxidant Defense and Glyoxalase Systems in Salt-Stressed Rice Seedlings

    Science.gov (United States)

    Rahman, Anisur; Nahar, Kamrun; Hasanuzzaman, Mirza; Fujita, Masayuki

    2016-01-01

    The present study investigates the regulatory role of exogenous calcium (Ca) in developing salt stress tolerance in rice seedlings. Hydroponically grown 13-day-old rice (Oryza sativa L. cv. BRRI dhan47) seedlings were exposed to 200 mM NaCl alone and combined with 2 mM CaCl2 and 2 mM ethylene glycol tetraacetic acid (EGTA, a Ca scavenger) for 3 days. The salt stress caused growth inhibition, chlorosis and water shortage in the rice seedlings. The salt-induced stress disrupted ion homeostasis through Na+ influx and K+ efflux, and decreased other mineral nutrient uptake. Salt stress caused oxidative stress in seedlings through lipid peroxidation, loss of plasma membrane integrity, higher reactive oxygen species (ROS) production and methylglyoxal (MG) formation. The salt-stressed seedlings supplemented with exogenous Ca recovered from water loss, chlorosis and growth inhibition. Calcium supplementation in the salt-stressed rice seedlings improved ion homeostasis by inhibition of Na+ influx and K+ leakage. Exogenous Ca also improved ROS and MG detoxification by improving the antioxidant defense and glyoxalase systems, respectively. On the other hand, applying EGTA along with salt and Ca again negatively affected the seedlings as EGTA negated Ca activity. It confirms that, the positive responses in salt-stressed rice seedlings to exogenous Ca were for Ca mediated improvement of ion homeostasis, antioxidant defense and glyoxalase system.

  8. Oral Rg1 supplementation strengthens antioxidant defense system against exercise-induced oxidative stress in rat skeletal muscles

    Directory of Open Access Journals (Sweden)

    Yu Szu-Hsien

    2012-05-01

    Full Text Available Abstract Background Previous studies reported divergent results on nutraceutical actions and free radical scavenging capability of ginseng extracts. Variations in ginsenoside profile of ginseng due to different soil and cultivating season may contribute to the inconsistency. To circumvent this drawback, we assessed the effect of major ginsenoside-Rg1 (Rg1 on skeletal muscle antioxidant defense system against exhaustive exercise-induced oxidative stress. Methods Forty weight-matched rats were evenly divided into control (N = 20 and Rg1 (N = 20 groups. Rg1 was orally administered at the dose of 0.1 mg/kg bodyweight per day for 10-week. After this long-term Rg1 administration, ten rats from each group performed an exhaustive swimming, and remaining rats considered as non-exercise control. Tibialis anterior (TA muscles were surgically collected immediately after exercise along with non-exercise rats. Results Exhaustive exercise significantly (p Conclusions This study provide compelling evidences that Rg1 supplementation can strengthen antioxidant defense system in skeletal muscle and completely attenuate the membrane lipid peroxidation induced by exhaustive exercise. Our findings suggest that Rg1 can use as a nutraceutical supplement to buffer the exhaustive exercise-induced oxidative stress.

  9. Defense Mechanisms in Females as a Function of Sex-Role Orientation.

    Science.gov (United States)

    Evans, Ronald G.

    1982-01-01

    Studied influence of sex roles on defense mechanisms. Females completed Defense Mechanisms Inventory (DMI) and Bem Sex Role Inventory (BSRI). Low masculinity on the BSRI was associated with high Turning Against Self on the DMI. High masculine subjects indicated greater willingness to attack objects of frustration. (Author)

  10. Influence of Defense Mechanisms on Moral Judgment Development: A Longitudinal Study.

    Science.gov (United States)

    Hart, Daniel; Chmiel, Susan

    1992-01-01

    At age 13, and for the next 20 years, male subjects were periodically interviewed about their moral judgments. Adolescents with mature use of defense mechanisms reasoned at higher stages of moral judgment 10 to 20 years after the initial interview than did those with immature use of defense mechanisms. (BC)

  11. Influence of season and pollution on the antioxidant defenses of the cichlid fish acará (Geophagus brasiliensis

    Directory of Open Access Journals (Sweden)

    D. Wilhelm Filho

    2001-06-01

    Full Text Available The livers of Geophagus brasiliensis collected from both a non-polluted site and a polluted site were analyzed for different antioxidant defenses, O2 consumption, thiobarbituric acid-reactive substance (TBARS levels, and histological damage. Compared to controls (116.6 ± 26.1 nmol g-1, TBARS levels were enhanced at the polluted site (284.2 ± 25.6 nmol g-1, as also was oxygen consumption (86.6 ± 11.3 and 128.5 ± 9.8 µmol O2 min-1 g-1, respectively. With respect to enzymatic antioxidants, increased catalase activities (8.7 ± 1.3 and 29.2 ± 2.4 mmol min-1 g-1, respectively, unchanged superoxide dismutase activities (767.2 ± 113.3 and 563.3 ± 70.2 U g-1, respectively, and diminished glutathione S-transferase activities (29.0 ± 3.2 and 14.9 ± 3.2 µmol min-1 g-1, respectively were detected. Reduced glutathione (1.91 ± 0.17 and 1.37 ± 0.25 mM, respectively, oxidized glutathione (1.50 ± 0.20 and 0.73 ± 0.17 mM, respectively, and total glutathione (3.40 ± 0.26 and 2.07 ± 0.27 mM, respectively concentrations were also below control values at the polluted site. Nevertheless, the observed ethoxyresorufin-O-deethylase activities (1.34 ± 0.11 and 16.7 ± 0.21 pmol min-1 mg-1, respectively showed enhanced values at the polluted site. The main histological damage observed in the hepatocytes from fish collected at the polluted site was characterized by heavy lipid infiltration. Fish collected at the end of spring showed higher O2 consumption, higher superoxide dismutase and glutathione S-transferase activities, and higher total and oxidized glutathione concentrations compared to the beginning of autumn. No seasonal changes were observed in catalase activities, glutathione or TBARS levels. Fish chronically exposed to relatively high pollution levels seem to be unable to set up adequate antioxidant defenses, probably due to severe injury to their hepatocytes. The higher antioxidant defenses found at the end of spring are probably related to the

  12. Effect of nonylphenol on male reproduction: Analysis of rat epididymal biochemical markers and antioxidant defense enzymes

    International Nuclear Information System (INIS)

    The mechanism by which nonylphenol (NP) interferes with male reproduction is not fully elucidated. Therefore, the present study was conducted to evaluate the effect of NP on male reproductive organ's weight, sperm characteristics, and to elucidate the nature and mechanism of action of NP on the epididymis. Adult male Wistar rats were gavaged with NP, dissolved in corn oil, at 0, 100, 200 or 300 mg/kg/day for 30 consecutive days. Control rats were gavaged with vehicle (corn oil) alone. Body weight did not show any significant change while, absolute testes and epididymides weights were significantly decreased. Sperm count in cauda and caput/corpus epididymides, and sperm motility was significantly decreased. Daily sperm production was significantly decreased in a dose-related manner. Sperm transit time in cauda epididymis was significantly decreased by 300 mg/kg, while in the caput/corpus epididymis it was significantly decreased by 200 and 300 mg/kg of NP. Plasma LDH was significantly increased while; plasma testosterone was significantly decreased in a dose-related pattern. In the epididymal sperm, NP decreased acrosome integrity, Δψm and 5′-nucleotidase activity. Hydrogen peroxide (H2O2) production and LPO were significantly increased in a dose-related pattern. The activities of SOD, CAT and GPx were significantly decreased in the epididymal sperm. In conclusion, this study revealed that NP treatment impairs spermatogenesis and has a cytotoxic effect on epididymal sperm. It disrupts the prooxidant and antioxidant balance. This leads oxidative stress in epididymal sperms of rat. Moreover, the reduction in sperm transit time may affect sperm quality and fertility potential. -- Highlights: ► The nature and mechanism of action of NP on rat epididymis were elucidated. ► NP decreased sperm count, motility, daily sperm production and sperm transit time. ► NP decreased sperm acrosome integrity, Δψm and 5′-nucleotidase activity. ► Plasma LDH was

  13. Antioxidant defense system and family environment in adolescents with family history of psychosis

    Directory of Open Access Journals (Sweden)

    Gonzalez-Pinto Ana

    2012-11-01

    Full Text Available Abstract Background Our objective was to determine antioxidant defence activity in healthy controls (HC and healthy unaffected second-degree relatives of patients with early onset psychosis (HC-FHP, and to assess its relationship with familiar environment measured using the Family Environment Scale (FES. Methods We included 82 HC and 14 HC-FHP aged between 9 and 17 years. Total antioxidant status, lipid peroxidation, antioxidant enzyme activities and glutathione levels were determined in blood samples. Results There was a significant decrease in the total antioxidant level in the HC-FHP group compared with the HC group (OR = 2.94; p = 0.009, but no between-group differences in the Global Assessment of Functioning (GAF scale scores. For the FES, the HC-FHP group had significantly higher scores in the cohesion (p = 0.007 and intellectual-cultural dimensions (p=0.025. After adjusting for these two FES dimensions, total antioxidant status remained significantly different between groups (OR = 10.86, p = 0.009. Conclusions Although causal relationships cannot be assumed, we can state that family environment is not playing a role in inducing oxidative stress in these healthy subjects. It could be hypothesized that families with affected relatives protect themselves from psychosis with positive environmental factors such as cohesion and intellectual-cultural activities.

  14. Mechanical defenses of plant extrafloral nectaries against herbivory.

    Science.gov (United States)

    Gish, Moshe; Mescher, Mark C; De Moraes, Consuelo M

    2016-01-01

    Extrafloral nectaries play an important role in plant defense against herbivores by providing nectar rewards that attract ants and other carnivorous insects. However, extrafloral nectaries can themselves be targets of herbivory, in addition to being exploited by nectar-robbing insects that do not provide defensive services. We recently found that the extrafloral nectaries of Vicia faba plants, as well as immediately adjacent tissues, exhibit high concentrations of chemical toxins, apparently as a defense against herbivory. Here we report that the nectary tissues of this plant also exhibit high levels of structural stiffness compared to surrounding tissues, likely due to cell wall lignification and the concentration of calcium oxalate crystals in nectary tissues, which may provide an additional deterrent to herbivore feeding on nectary tissues. PMID:27489584

  15. Defense Mechanisms of Rosaceous Plants against Fire Blight Pathogen Erwinia amylovora

    OpenAIRE

    Vrancken, Kristof; HOLTAPPELS, Michelle; Valcke, Roland; Schoofs, H.; Deckers, T; Bylemans, D.

    2014-01-01

    Plants are host to an important amount of infectious diseases caused by a vast array of fungi, bacteria, viruses and nematodes. In great contrast to the mammalian immune system composed of specialized and mobile defense cells such as lymphocytes, plants have to rely on the ability of each cell to recognize a pathogen and the signals emanating from the infection site to generate several defense mechanisms, either in a preformed or an inducible way. Inducible defense responses are triggered whe...

  16. Activation of Defense Mechanisms against Pathogens in Mosses and Flowering Plants

    OpenAIRE

    Inés Ponce de León; Marcos Montesano

    2013-01-01

    During evolution, plants have developed mechanisms to cope with and adapt to different types of stress, including microbial infection. Once the stress is sensed, signaling pathways are activated, leading to the induced expression of genes with different roles in defense. Mosses (Bryophytes) are non-vascular plants that diverged from flowering plants more than 450 million years ago, allowing comparative studies of the evolution of defense-related genes and defensive metabolites produced after ...

  17. Bio-antioxidants Activity: Their Mechanisms and Measurement Methods

    OpenAIRE

    M.A Sahari; S Berenji Ardestani

    2014-01-01

    Bioactive food components (such as phenolic compounds, carotenoids, anthocyanins, tochopherols, ascorbic acid, flavonoids, minerals, enzymes and pectin) are active ingredients in food or dietary supplements, which proven to have an important role in health, and are safe for human consumption. These compounds exert their antioxidant effects by different mechanisms such as single electron transfer or hydrogen atom transfer, and their efficiencies can be evaluated by several methods such as ferr...

  18. Beta-carotene reduces oxidative stress, improves glutathione metabolism and modifies antioxidant defense systems in lead-exposed workers

    International Nuclear Information System (INIS)

    The aim of this study was to determine whether beta-carotene administration reduces oxidative stress and influences antioxidant, mainly glutathione-related, defense systems in workers chronically exposed to lead. The population consisted of two randomly divided groups of healthy male volunteers exposed to lead. Workers in the first group (reference group) were not administered any antioxidants, while workers in the second group (CAR group) were treated orally with 10 mg of beta-carotene once a day for 12 weeks. Biochemical analysis included measuring markers of lead-exposure and oxidative stress in addition to the levels and activities of selected antioxidants. After treatment, levels of malondialdehyde, lipid hydroperoxides and lipofuscin significantly decreased compared with the reference group. However, the level of glutathione significantly increased compared with the baseline. Treatment with beta-carotene also resulted in significantly decreased glutathione peroxidase activity compared with the reference group, while the activities of other glutathione-related enzymes and of superoxide dismutase were not significantly changed. However, the activities of glucose-6-phosphate dehydrogenase and catalase, as well as the level of alpha-tocopherol, were significantly higher after treatment compared with the baseline. Despite controversy over the antioxidant properties of beta-carotene in vivo, our findings showed reduced oxidative stress after beta-carotene supplementation in chronic lead poisoning. - Highlights: • Beta-carotene reduces oxidative stress in lead-exposed workers. • Beta-carotene elevates glutathione level in lead-exposed workers. • Beta-carotene administration could be beneficial in lead poisoning

  19. Beta-carotene reduces oxidative stress, improves glutathione metabolism and modifies antioxidant defense systems in lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    Kasperczyk, Sławomir, E-mail: kaslav@mp.pl [Dept. of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland); Dobrakowski, Michał [Dept. of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland); Kasperczyk, Janusz [Dept. of Environmental Medicine and Epidemiology, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland); Ostałowska, Alina; Zalejska-Fiolka, Jolanta; Birkner, Ewa [Dept. of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland)

    2014-10-01

    The aim of this study was to determine whether beta-carotene administration reduces oxidative stress and influences antioxidant, mainly glutathione-related, defense systems in workers chronically exposed to lead. The population consisted of two randomly divided groups of healthy male volunteers exposed to lead. Workers in the first group (reference group) were not administered any antioxidants, while workers in the second group (CAR group) were treated orally with 10 mg of beta-carotene once a day for 12 weeks. Biochemical analysis included measuring markers of lead-exposure and oxidative stress in addition to the levels and activities of selected antioxidants. After treatment, levels of malondialdehyde, lipid hydroperoxides and lipofuscin significantly decreased compared with the reference group. However, the level of glutathione significantly increased compared with the baseline. Treatment with beta-carotene also resulted in significantly decreased glutathione peroxidase activity compared with the reference group, while the activities of other glutathione-related enzymes and of superoxide dismutase were not significantly changed. However, the activities of glucose-6-phosphate dehydrogenase and catalase, as well as the level of alpha-tocopherol, were significantly higher after treatment compared with the baseline. Despite controversy over the antioxidant properties of beta-carotene in vivo, our findings showed reduced oxidative stress after beta-carotene supplementation in chronic lead poisoning. - Highlights: • Beta-carotene reduces oxidative stress in lead-exposed workers. • Beta-carotene elevates glutathione level in lead-exposed workers. • Beta-carotene administration could be beneficial in lead poisoning.

  20. Antioxidants of Edible Mushrooms

    Directory of Open Access Journals (Sweden)

    Maja Kozarski

    2015-10-01

    Full Text Available Oxidative stress caused by an imbalanced metabolism and an excess of reactive oxygen species (ROS lead to a range of health disorders in humans. Our endogenous antioxidant defense mechanisms and our dietary intake of antioxidants potentially regulate our oxidative homeostasis. Numerous synthetic antioxidants can effectively improve defense mechanisms, but because of their adverse toxic effects under certain conditions, preference is given to natural compounds. Consequently, the requirements for natural, alternative sources of antioxidant foods identified in edible mushrooms, as well as the mechanistic action involved in their antioxidant properties, have increased rapidly. Chemical composition and antioxidant potential of mushrooms have been intensively studied. Edible mushrooms might be used directly in enhancement of antioxidant defenses through dietary supplementation to reduce the level of oxidative stress. Wild or cultivated, they have been related to significant antioxidant properties due to their bioactive compounds, such as polyphenols, polysaccharides, vitamins, carotenoids and minerals. Antioxidant and health benefits, observed in edible mushrooms, seem an additional reason for their traditional use as a popular delicacy food. This review discusses the consumption of edible mushrooms as a powerful instrument in maintaining health, longevity and life quality.

  1. Change in Coping and Defense Mechanisms across Adulthood: Longitudinal Findings in a European-American Sample

    OpenAIRE

    Diehl, Manfred; Chui, Helena; Hay, Elizabeth L.; Lumley, Mark A.; Grühn, Daniel; Labouvie-Vief, Gisela

    2013-01-01

    This study examined longitudinal changes in coping and defense mechanisms in an age- and gender-stratified sample of 392 European-American adults. Nonlinear age-related changes were found for the coping mechanisms of sublimation and suppression and the defense mechanisms of intellectualization, doubt, displacement, and regression. The change trajectories for sublimation and suppression showed that their use increased from adolescence to late middle age and early old age, and remained mostly s...

  2. Vitaminas y oxidorreductasas antioxidantes: defensa ante el estrés oxidativo Antioxidant vitamins and oxidoreductases: a defense against oxidative stress

    Directory of Open Access Journals (Sweden)

    Daniel Eugenio Benítez Zequeira

    2006-06-01

    Full Text Available Se realizó una revisión que comprende aspectos morfológicos y funcionales de agentes oxidantes y antioxidantes, así como los mecanismos bioquímicos que los involucran en la defensa antioxidante del organismo. Se conoce como estrés oxidativo a los efectos morbosos debidos al desequilibrio entre la acción de agentes oxidantes sobre las células y la respuesta antioxidante de estas. Los agentes oxidantes pueden ser exógenos (fármacos y venenos y endógenos (como las especies reactivas del oxígeno y los peróxidos lipídicos. Por otra parte, la dotación antioxidante del organismo humano también cuenta con miembros externos e internos. Entre los primeros figuran las vitaminas antioxidantes y minerales como el hierro y el selenio, ingresados formando parte de los alimentos o como suplemento nutritivo; internamente, se encuentran hemoenzimas oxidorreductasas y metabolitos intermediarios como el glutatión. Muchos procesos patológicos como entidades nosológicas en sí, se acompañan de estrés oxidativo, expresándose en la peroxidación de biomembranas y la subsiguiente apoptosis, lo cual podría acarrear la muerte celularA review that includes morphological and functional aspects of oxidant and antioxidant agents, as well as the biochemical mechanisms involving them in the antioxidant defense of the body was made. Oxidative stress is known as the morbid effects due to the unbalance between the action of oxidant agents on the cells and the antioxidant response. Oxidant agents can be exogenous (drugs and poisons and endogenous (like the Reactive Oxygen Species and lipid peroxides. On the other hand, the antioxidant complement of the human organism has also both external and internal members. Among the first ones there are antioxidant vitamins and minerals, such as iron and selenium, which have come into the cell as part of food or as a diet supplement. Oxidoreductase hemoenzymes and intermediary metabolites as gluthatione are internally

  3. Heavy metal induced antioxidant defense system of green microalgae and its effective role in phycoremediation of tannery effluent.

    Science.gov (United States)

    Ajayan, K V; Selvaraju, M

    2012-11-15

    Investigation of tannery effluent toxicology in green microalgae is of great importance from ecological point of view, because heavy metal has become a major contaminant in recent years. The present study determined the effect of various concentrations (0, 10, 25, 50, 75 and 100%) of heavy metals containing tannery effluent on cell growth and antioxidant defense system of two green microalgae. Treatment with effluent induced accumulation of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). Lower tannery effluent concentrations increased algal growth, whereas higher concentration suppressed the growth and photosynthetic content. Both strains of the microalgae had proven effective in removing heavy metals from aqueous solutions with the highest removal efficiency being near 100% and it can be used for phycoremediation of wastewater in large scale. PMID:24261120

  4. Nitric Oxide Mediates 5-Aminolevulinic Acid-Induced Antioxidant Defense in Leaves of Elymus nutans Griseb. Exposed to Chilling Stress.

    Directory of Open Access Journals (Sweden)

    Juanjuan Fu

    Full Text Available Nitric oxide (NO and 5-aminolevulinic acid (ALA are both extremely important signalling molecules employed by plants to control many aspects of physiology. In the present study, the role of NO in ALA-induced antioxidant defense in leaves of two sources of Elymus nutans Griseb. (Damxung, DX and Zhengdao, ZD was investigated. Chilling stress enhanced electrolyte leakage, accumulation of malondialdehyde (MDA, hydrogen peroxide (H2O2 and superoxide radical in two E. nutans, which were substantially alleviated by exogenous ALA and NO application. Pretreatment with NO scavenger PTIO or NOS inhibitor L-NNA alone and in combination with ALA induced enhancements in electrolyte leakage and the accumulation of MDA, H2O2 and superoxide radical in leaves of DX and ZD exposed to chilling stress, indicating that the inhibition of NO biosynthesis reduced the chilling resistance of E. nutans and the ALA-enhanced chilling resistance. Further analyses showed that ALA and NO enhanced antioxidant defense and activated plasma membrane (PM H+-ATPase and decreased the accumulation of ROS induced by chilling stress. A pronounced increase in nitric oxide synthase (NOS activity and NO release by exogenous ALA treatment was found in chilling-resistant DX plants exposed to chilling stress, while only a little increase was observed in chilling-sensitive ZD. Furthermore, inhibition of NO accumulation by PTIO or L-NNA blocked the protective effect of exogenous ALA, while both exogenous NO treatment and inhibition of endogenous NO accumulation did not induce ALA production. These results suggested that NO might be a downstream signal mediating ALA-induced chilling resistance in E. nutans.

  5. Effect of chromium (VI) exposure on antioxidant defense status and trace element homeostasis in acute experiment in rat.

    Science.gov (United States)

    Kotyzová, Dana; Hodková, Anna; Bludovská, Monika; Eybl, Vladislav

    2015-11-01

    Occupational exposure to hexavalent chromium (Cr(VI)) compounds is of concern in many Cr-related industries and their surrounding environment. Cr(VI) is a proven toxin and carcinogen. The Cr(VI) compounds are easily absorbed, can diffuse across cell membranes, and have strong oxidative potential. Despite intensive studies of Cr(VI) pro-oxidative effects, limited data exist on the influence of Cr(VI) on selenoenzymes thioredoxin reductase (TrxR) and glutathione peroxidase (GPx)-important components of antioxidant defense system. This study investigates the effect of Cr(VI) exposure on antioxidant defense status, with focus on these selenoenzymes, and on trace element homeostasis in an acute experiment in rat. Male Wistar rats (130-140g) were assigned to two groups of 8 animals: I. control; and II. Cr(VI) treated. The animals in Cr(VI) group were administered a single dose of K2Cr2O7 (20 mg /kg, intraperitoneally (ip)). The control group received saline solution. After 24 h, the animals were sacrificed and the liver and kidneys were examined for lipid peroxidation (LP; thiobarbituric acid reactive substances (TBARS) concentration), the level of reduced glutathione (GSH) and the activities of GPx-1, TrxR-1, and glutathione reductase (GR). Samples of tissues were also used to estimate Cr accumulation and alterations in zinc, copper, and iron levels. The acute Cr(VI) exposure caused an increase in both hepatic and renal LP (by 70%, p effect of Cr(VI) was found on TrxR-1 activity in both the liver and the kidneys. The ability of Cr(VI) to cause TrxR inhibition could contribute to its cytotoxic effects. Further investigation of oxidative responses in different in vivo models may enable the development of strategies to protect against Cr(VI) oxidative damage. PMID:23625905

  6. Possible role of glutamine synthetase in the NO signaling response in root nodules by contributing to the antioxidant defenses

    Directory of Open Access Journals (Sweden)

    Liliana Santos Silva

    2013-09-01

    Full Text Available Nitric oxide (NO is emerging as an important regulatory player in the Rhizobium-legume symbiosis. The occurrence of NO during several steps of the symbiotic interaction suggests an important, but yet unknown, signaling role of this molecule for root nodule formation and functioning. The identification of the molecular targets of NO is key for the assembly of the signal transduction cascade that will ultimately help to unravel NO function. We have recently shown that the key nitrogen assimilatory enzyme Glutamine Synthetase (GS is a molecular target of NO in root nodules of Medicago truncatula, being post-translationally regulated by tyrosine nitration in relation to nitrogen fixation. In functional nodules of M. truncatula NO formation has been located in the bacteroid containing cells of the fixation zone, where the ammonium generated by bacterial nitrogenase is released to the plant cytosol and assimilated into the organic pools by plant GS. We propose that the NO-mediated GS post-translational inactivation is connected to nitrogenase inhibition induced by NO and is related to metabolite channeling to boost the nodule antioxidant defenses. Glutamate, a substrate for GS activity is also the precursor for the synthesis of glutathione (GSH, which is highly abundant in root nodules of several plant species and known to play a major role in the antioxidant defense participating in the ascorbate/GSH cycle. Existing evidence suggests that upon NO-mediated GS inhibition, glutamate could be channeled for the synthesis of GSH. According to this hypothesis, GS would be involved in the NO-signaling responses in root nodules and the NO-signaling events would meet the nodule metabolic pathways to provide an adaptive response to the inhibition of symbiotic nitrogen fixation by reactive nitrogen species (RNS.

  7. 24-epibrassinolide induced antioxidative defense system of Brassica juncea L. under Zn metal stress

    OpenAIRE

    Arora, Priya; Bhardwaj, Renu; Kumar Kanwar, Mukesh

    2010-01-01

    The present study deals with the effects of 24-epibrassinolide on growth, lipid peroxidation, antioxidative enzyme activities, non-enzymatic antioxidants and protein content in 30 days old leaves of Brassica juncea (var. PBR 91) under zinc metal stress in field conditions. Surface sterilized seeds of B. juncea were given pre-soaking treatments of 24-EBL (10−10, 10−8 and 10−6 M) for 8 h. Different concentrations of zinc metal in the form of ZnSO4.7H2O (0, 0.5, 1.0, 1.5 and 2.0 mM) were added i...

  8. A Comprehensive Review on Nickel (II And Chromium VI Toxicities - Possible Antioxidant (Allium Sativum Linn Defenses

    Directory of Open Access Journals (Sweden)

    Kusal K.Das

    2009-12-01

    Full Text Available The toxicity associated with nickel (II and chromium (VI is mainly due to generation of reactive oxygen species (ROS with subsequent oxidative deterioration of biological macromolecules. Both nickel and chromium can generate free radicals (FR directly from molecular oxygen in a two step process to produce superoxide anion and in continued process, produce highly toxic hydroxyl radical. The pro-oxidative effects are compounded by fact that they also inhibit antioxidant enzymes and deplete intracellular glutathione. Garlic (Allium sativum has played an important dietary and medicinal role throughout the history of mankind. Garlic has the potential to enhance the endogenous antioxidant status in nickel as well as hexavalent chromium induced lipid peroxidation in normal and diabetic rats.

  9. Effects of grape pomace on the antioxidant defense system in diet-induced hypercholesterolemic rabbits

    OpenAIRE

    Choi, Chang-Sook; Chung, Hae-Kyung; CHOI, Mi-Kyung; Kang, Myung-Hwa

    2010-01-01

    The effects of grape seeds extract and grape peels extract prepared from grape pomace on the activity of antioxidant enzymes, degree of lipid peroxidation in serum and liver tissue were investigated in rabbits fed on high cholesterol diet. New Zealand white rabbits were divided as follows ; 1) NOR (normal group); 2) CHOL (cholesterol group); 3) GSH (cholesterol + grape seed extract group); 4) GPE (cholesterol + grape peel extract); 5) GSP (cholesterol + grape seed powder); 6) GPP (cholesterol...

  10. A Comprehensive Review on Nickel (II) And Chromium VI Toxicities - Possible Antioxidant (Allium Sativum Linn) Defenses

    OpenAIRE

    Kusal K. Das

    2009-01-01

    The toxicity associated with nickel (II) and chromium (VI) is mainly due to generation of reactive oxygen species (ROS) with subsequent oxidative deterioration of biological macromolecules. Both nickel and chromium can generate free radicals (FR) directly from molecular oxygen in a two step process to produce superoxide anion and in continued process, produce highly toxic hydroxyl radical. The pro-oxidative effects are compounded by fact that they also inhibit antioxidant enzymes and deplete ...

  11. The effect of intestinal ischemia duration on changes in plasma antioxidant defense status in the rats

    Czech Academy of Sciences Publication Activity Database

    Čížová, Hana; Lojek, Antonín; Kubala, Lukáš; Číž, Milan

    2004-01-01

    Roč. 53, č. 5 (2004), s. 523-531. ISSN 0862-8408 R&D Projects: GA ČR GA524/99/D022; GA ČR GA524/01/1219 Institutional research plan: CEZ:AV0Z5004920 Keywords : antioxidants * small intestine * ischemia-reperfusion Subject RIV: BO - Biophysics Impact factor: 1.140, year: 2004

  12. Impact of aerobic and anaerobic exercise training on oxidative stress and antioxidant defense in athletes

    Science.gov (United States)

    Park, Song-Young; Kwak, Yi-Sub

    2016-01-01

    Exercise mediates an excessive free radical production leading to oxidative stress (OS). The body has natural antioxidant systems that help decrease OS, and these systems may be enhanced with exercise training. However, only a few studies have investigated the differences in resting OS and antioxidant capacity (AOC) between aerobically trained athletes (ET), anaerobically trained athletes (RT), and untrained individuals (UT). Therefore, this study sought to investigate the resting and postexercise OS and AOC in ET, RT, and UT. Sixty healthy young males (26.6±0.8 yr) participated in this study. Subjects were divided into three groups, ET, RT, and UT by distinct training background. Resting plasma malondialdehyde (MDA) and protein carbonyls (PC) were not significantly different in ET, RT, and UT. However, MDA and PC were significantly increased following a graded exercise test (GXT) in UT but not in ET and RT. Resting total antioxidant capacity (TAC) levels and TAC were not different in ET, RT, and UT. Interestingly, TAC levels significantly decreased after the GXT in all groups. Additionally, UT showed lower post-exercise TAC levels compared to ET and RT. These results showed that ET, RT, and UT have similar OS and AOC at rest. However, both ET and RT have greater AOC against exercise mediated OS compared to UT. These findings may explain, at least in part, why both aerobic and anaerobic types of exercise training improve redox balance. However, it appears there is no specific exercise type effect in terms of redox balance.

  13. Impact of aerobic and anaerobic exercise training on oxidative stress and antioxidant defense in athletes.

    Science.gov (United States)

    Park, Song-Young; Kwak, Yi-Sub

    2016-04-01

    Exercise mediates an excessive free radical production leading to oxidative stress (OS). The body has natural antioxidant systems that help decrease OS, and these systems may be enhanced with exercise training. However, only a few studies have investigated the differences in resting OS and antioxidant capacity (AOC) between aerobically trained athletes (ET), anaerobically trained athletes (RT), and untrained individuals (UT). Therefore, this study sought to investigate the resting and postexercise OS and AOC in ET, RT, and UT. Sixty healthy young males (26.6±0.8 yr) participated in this study. Subjects were divided into three groups, ET, RT, and UT by distinct training background. Resting plasma malondialdehyde (MDA) and protein carbonyls (PC) were not significantly different in ET, RT, and UT. However, MDA and PC were significantly increased following a graded exercise test (GXT) in UT but not in ET and RT. Resting total antioxidant capacity (TAC) levels and TAC were not different in ET, RT, and UT. Interestingly, TAC levels significantly decreased after the GXT in all groups. Additionally, UT showed lower post-exercise TAC levels compared to ET and RT. These results showed that ET, RT, and UT have similar OS and AOC at rest. However, both ET and RT have greater AOC against exercise mediated OS compared to UT. These findings may explain, at least in part, why both aerobic and anaerobic types of exercise training improve redox balance. However, it appears there is no specific exercise type effect in terms of redox balance. PMID:27162773

  14. DIRECT EVALUATION OF OXIDATIVE STRESS AND ANTIOXIDANT DEFENSE PARAMETERS IN EXPERIMENT WITH THE AXIAL PUMP

    Directory of Open Access Journals (Sweden)

    N. V. Kuncevich

    2011-12-01

    Full Text Available It is established that increased parameters of oxidative stress result from an imbalance between reactive oxygen molecules and endogenous antioxidants. Oxidative stress parameters may be considered to be biomarkers of heart failure. The aim of our study was to asses oxidative stress and antioxidant system parameters in experi- mental model with the axial pump. Our study included 7 calves (the mean age 120.33 days, the mean weight 99.17 kg. We used «FORM Plus CR3000» analyzer (Callegary, Italy and heparinized venous blood samples for the evaluation of the oxidative status (FORT test and the total antioxidant capacity (FORD test. In healthy animals oxidative system parameters differ from those in humans (FORT – 0.42 ± 0.11 versus 1.74 ± 0.32 mmol/l H2O2; FORD/FORT – 3.92 ± 1.30 versus 1.33 ± 0.27, p < 0.05 what should be taken into consideration when interpreting the results of clinical and experimental studies. In three calves with experimental assisted circulation maximal oxidative stress values were observed on 1–3 days after the axial pump connection with the subsequent normalization of these parameters. Direct evaluation of oxidative stress parameters may be used as monitoring tool for estimation of assisted circulation adequacy in experiment (animal model. 

  15. Anti-hepatotoxic and anti-oxidant defense potential of Tridax procumbens

    Directory of Open Access Journals (Sweden)

    Hemalatha Reddipalli

    2008-01-01

    Full Text Available Tridax procumbens is a widely occurring medicinal herb used by ethnomedical practitioners. With increased use of chemicals and alcohol besides growing incidence of viruses and autoimmune diseases, the incidence of liver injury is growing for which conventional drugs used for treatment are often inadequate. Various models are adopted in pharmological studies for inducing hepatitis/ liver injury similar to those observed in human viral hepatitis, diabetes and oxidative stress. D-galactosamine with lipopolysacchride (LPS, carbontetrachloride (CCl 4 and paracetamol intoxication, diabetes induced with alloxan are widely used on rodents for this purpose. In vitro studies on Tridax procumbens (TP revealed the anti-oxidant potential of the herb with chloroform fraction of the ethanolic extract showing maximum activity. It is also reported to possess anti-oxidant minerals such as iron, magnesium, copper and zinc. In vivo studies on rodents on the anti-oxidant potential of TP induced through LPS, CCl 4, alloxan and paracetamol intoxication induced hepatitis confirmed the results from in vitro studies as a potential anti-hepatotoxic herb.

  16. The 6-a-day study: effects of fruit and vegetables on markers of oxidative stress and antioxidative defense in healthy nonsmokers

    DEFF Research Database (Denmark)

    Dragsted, Lars Ove; Pedersen, A.; Hermetter, A.;

    2004-01-01

    and vegetables/d; the placebo group received a placebo pill, and the supplement group received a vitamin pill designed to contain vitamins and minerals corresponding to those in 600 g fruit and vegetables. Biomarkers of oxidative damage to protein and lipids and of antioxidant nutrients and defense enzymes were...

  17. Changes in Antioxidant Defense System Using Different Lipid Emulsions in Parenteral Nutrition in Children after Hematopoietic Stem Cell Transplantation

    Directory of Open Access Journals (Sweden)

    María Auxiliadora Baena-Gómez

    2015-08-01

    Full Text Available Background: Traditionally, lipids used in parenteral nutrition (PN are based on ω-6 fatty acid-rich vegetable oils, such as soybean oil, with potential adverse effects involving oxidative stress. Methods: We evaluated the antioxidant defense system in children, after hematopoietic stem cell transplantation (HSCT, who were randomized to use a lipid emulsion with fish oil or soybean oil. Blood samples at baseline, at 10 days, and at the end of the PN were taken to analyze plasma retinol, α-tocopherol, β-carotene, coenzyme Q9 and coenzyme Q10 levels, and catalase (CAT, glutathione reductase (GR, glutathione peroxidase (GPOX, and superoxide dismutase (SOD levels in lysed erythrocytes. Results: An increase in plasma α-tocopherol levels in the group of patients receiving the fish oil-containing emulsion (FO compared with the group receiving the soybean emulsion was observed at day 10 of PN. Concurrently, plasma α-tocopherol increased in the FO group and β-carotene decreased in both groups at day 10 compared with baseline levels, being more significant in the group receiving the FO emulsion. Conclusion: FO-containing emulsions in PN could improve the antioxidant profile by increasing levels of α-tocopherol in children after HSCT who are at higher risk of suffering oxidative stress and metabolic disorders.

  18. Effects of cadmium on ultrastructure and antioxidative defense system in hyperaccumulator and non-hyperaccumulator ecotypes of Sedum alfredii Hance.

    Science.gov (United States)

    Jin, Xiaofen; Yang, Xiaoe; Islam, Ejazul; Liu, Dan; Mahmood, Qaisar

    2008-08-15

    Plant growth, ultrastructural and antioxidant adaptations and glutathione biosynthesis in Cd-hyperaccumulating ecotype Sedum alfredii Hance (HE) countering high Cd environment were investigated and compared with its non Cd-hyperaccumulating ecotype (NHE). Cadmium exposure resulted in significant ultrastructural changes in root meristem and leaf mesophyll cells of S. alfredii, but damage was more pronounced in NHE even when Cd concentrations were one-tenth of those applied to HE. Cadmium stress damaged chloroplasts causing imbalanced lamellae formation coupled with early leaf senescence. Histochemical results revealed that glutathione (GSH) biosynthesis inhibition led to overproduction of hydrogen peroxide (H(2)O(2)) and superoxide radical (O(2)(*-)) in HE but not in NHE. Differences were noted in both HE and NHE for catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and glutathione reductase (GR) activities under various Cd stress levels. No relationship was found between antioxidative defense capacity including activities of superoxide dismutase (SOD), CAT, GPX, APX and GR as well as ascorbic acid (AsA) contents and Cd tolerance in the two ecotypes of S. alfredii. The GSH biosynthesis induction in root and shoot exposed to elevated Cd conditions may be involved in Cd tolerance and hyperaccumulation in HE of S. alfredii H. PMID:18242844

  19. Effects of cadmium on ultrastructure and antioxidative defense system in hyperaccumulator and non-hyperaccumulator ecotypes of Sedum alfredii Hance

    Energy Technology Data Exchange (ETDEWEB)

    Jin Xiaofen [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China); Yang Xiaoe [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China)], E-mail: xyang@zju.edu.cn; Islam, Ejazul [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China); Nuclear Institute of Agriculture, Tandojam 48800, Hyderabad (Pakistan); Liu Dan [School of Tourism and Health, Zhejiang Forestry College, 311300 Lin' an (China); Mahmood, Qaisar [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China)

    2008-08-15

    Plant growth, ultrastructural and antioxidant adaptations and glutathione biosynthesis in Cd-hyperaccumulating ecotype Sedum alfredii Hance (HE) countering high Cd environment were investigated and compared with its non Cd-hyperaccumulating ecotype (NHE). Cadmium exposure resulted in significant ultrastructural changes in root meristem and leaf mesophyll cells of S. alfredii, but damage was more pronounced in NHE even when Cd concentrations were one-tenth of those applied to HE. Cadmium stress damaged chloroplasts causing imbalanced lamellae formation coupled with early leaf senescence. Histochemical results revealed that glutathione (GSH) biosynthesis inhibition led to overproduction of hydrogen peroxide (H{sub 2}O{sub 2}) and superoxide radical (O{sub 2}{center_dot}{sup -}) in HE but not in NHE. Differences were noted in both HE and NHE for catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and glutathione reductase (GR) activities under various Cd stress levels. No relationship was found between antioxidative defense capacity including activities of superoxide dismutase (SOD), CAT, GPX, APX and GR as well as ascorbic acid (AsA) contents and Cd tolerance in the two ecotypes of S. alfredii. The GSH biosynthesis induction in root and shoot exposed to elevated Cd conditions may be involved in Cd tolerance and hyperaccumulation in HE of S. alfredii H.

  20. Methyl jasmonate effectively enhanced some defense enzymes activity and Total Antioxidant content in harvested "Sabrosa" strawberry fruit.

    Science.gov (United States)

    Asghari, Mohammadreza; Hasanlooe, Ali Rashid

    2016-05-01

    The use of chemicals in postharvest technology of horticultural crops is highly restricted and it is necessary to introduce safe food preserving methods. Strawberry is very susceptible to postharvest losses and more than 50% of harvested fruit is lost in Iran. Effect of postharvest treatment with methyl jasmonate (at 0, 8, and 16 μmol L(-1)) on some quality attributes of Sabrosa strawberry fruit during storage at 1 ± 0.5°C with 90-95% RH for 14 days followed by 24 h at 20°C was studied. Methyl jasmonate, at both concentrations, decreased weight loss and retained marketability of fruits. Catalase activity of treated fruits was decreased during the first days, but showed a substantial increase during the second week. Methyl jasmonate, in a concentration-dependent manner, enhanced peroxidase activity. Fruit total antioxidant capacity was enhanced by methyl jasmonate treatment. The results indicated that methyl jasmonate plays a key role in establishing resistance against stresses, enhancing fruit defense systems, antioxidant capacity, and storage life leading to decreased postharvest losses. This phytochemical has a good potential to be used in postharvest technology of Sabrosa strawberry fruit and enhance the fruit postharvest life. PMID:27247768

  1. Effects of cadmium on ultrastructure and antioxidative defense system in hyperaccumulator and non-hyperaccumulator ecotypes of Sedum alfredii Hance

    International Nuclear Information System (INIS)

    Plant growth, ultrastructural and antioxidant adaptations and glutathione biosynthesis in Cd-hyperaccumulating ecotype Sedum alfredii Hance (HE) countering high Cd environment were investigated and compared with its non Cd-hyperaccumulating ecotype (NHE). Cadmium exposure resulted in significant ultrastructural changes in root meristem and leaf mesophyll cells of S. alfredii, but damage was more pronounced in NHE even when Cd concentrations were one-tenth of those applied to HE. Cadmium stress damaged chloroplasts causing imbalanced lamellae formation coupled with early leaf senescence. Histochemical results revealed that glutathione (GSH) biosynthesis inhibition led to overproduction of hydrogen peroxide (H2O2) and superoxide radical (O2·-) in HE but not in NHE. Differences were noted in both HE and NHE for catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and glutathione reductase (GR) activities under various Cd stress levels. No relationship was found between antioxidative defense capacity including activities of superoxide dismutase (SOD), CAT, GPX, APX and GR as well as ascorbic acid (AsA) contents and Cd tolerance in the two ecotypes of S. alfredii. The GSH biosynthesis induction in root and shoot exposed to elevated Cd conditions may be involved in Cd tolerance and hyperaccumulation in HE of S. alfredii H

  2. Heat-induced regulation of antioxidant defense system and nutrient accumulation in hexaploid bread wheat (triticum aestivum l.)

    International Nuclear Information System (INIS)

    Ten cultivars (five registered S-24, Inqlab-91, Saher-2006, Fsd-2008, and Lasani, and five candidate cultivars P.B-18, M.P-65, S.H-20, AARI-10, and G.A-20) of spring wheat (Triticum aestivum L.) were examined for high temperature stress tolerance. Plants were grown in soil filled pots in the Botanical Garden of the Department of Botany University of Agriculture Faisalabad, Pakistan. Three different temperature regimes (30, 40 and 50 degree C) were applied at two different growth stages (tillering and boot) for three temperature durations 30, 60 and 90 min in a growth chamber. The leaf and root samples were collected after two weeks of temperature treatment and then analyzed for enzymatic and non-enzymatic antioxidants as well as inorganic nutrients (N, P, K+, Ca2+). At the end, data obtained were statistically analyzed to distinguish heat tolerant from non-tolerant wheat cultivars. After appraisal of growth, antioxidant defense system and uptake of nutrients it was found that cvs. S-24, Inqlab-91, Saher-2006, Fsd-2008, Lasani and G.A-20 exhibited better thermo-tolerance capabilities than the other wheat cultivars (P.B-18, M.P-65, S.H-20, AARI-10). Among the thermo-tolerant wheat cultivars, G.A-20 and Lasani were superior in maintaining shoot fresh weights and shoot length, high antioxidant activities and better nutrient uptake at both tillering and boot stages. The response of all cultivars to heat stress applied at the tillering stage or boot stage was almost the same. (author)

  3. DMPD: The interferon regulatory factor family in host defense: mechanism of action. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17502370 The interferon regulatory factor family in host defense: mechanism of acti....html) (.csml) Show The interferon regulatory factor family in host defense: mechanism of action. PubmedID 1...7502370 Title The interferon regulatory factor family in host defense: mechanism

  4. The Child's Demystification of Psychological Defense Mechanisms: A Structural and Developmental Analysis.

    Science.gov (United States)

    Chandler, Michael J.; And Others

    1978-01-01

    Explored the relationships between the cognitive developmental level of preoperational, concrete operational, and formal operational children (N=10) and their success in interpreting and explaining each of eight commonly described mechanisms of psychological defense. (JMB)

  5. Stress and ego-defense mechanisms in medical staff at oncology and physical medicine departments

    OpenAIRE

    Sandra Kocijan Lovko; Rudolf Gregurek; Dalibor Karlovic

    2007-01-01

    Background and Objectives: Work on the oncology department has proved to be very stressful, so the medical staff indirectly copes with it by trying to escape it through the ego-defense mechanisms. On the other hand, working on the physical medicine department does not seem to be so stressful. The objective of this study was to determine the main ego- defense mechanisms at oncology and physical medicine department and to explain the differences between their frequencies. The other part was to ...

  6. What Makes Her Tick? : Katniss Everdeen's Use of Defense Mechanisms in The Hunger Games

    OpenAIRE

    Ramberg, Malin

    2012-01-01

    This essay deals with the character Katniss Everdeen in the novel The Hunger Games by SuzanneCollins. The essay shows that Katniss' behavior and actions in the novel can be explained byshowing her use of defense mechanisms, and that from a psychoanalytical perspective, she iscompletely logical in the way she acts. The defense mechanisms Katniss uses are withdrawal,reaction formation, altruistic surrender, intellectualization, and suppression. The behavior Katnissillustrates due to her use of ...

  7. Ego defense mechanisms in Pakistani medical students: a cross sectional analysis

    OpenAIRE

    Khalid Roha; Khwaja Nadia M; Khalid Salman; Khan Anum B; Khan Tuba R; Majeed Hina; Parekh Maria A; Khan Mohammad A; Rizqui Ibrahim M; Jehan Imtiaz

    2010-01-01

    Abstract Background Ego defense mechanisms (or factors), defined by Freud as unconscious resources used by the ego to reduce conflict between the id and superego, are a reflection of how an individual deals with conflict and stress. This study assesses the prevalence of various ego defense mechanisms employed by medical students of Karachi, which is a group with higher stress levels than the general population. Methods A questionnaire based cross-sectional study was conducted on 682 students ...

  8. Activation of chemical biological defense mechanisms and remission of vital oxidative injury by low dose radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamaoka, K. [Okayama University Medical School, Okayama (Japan); Nomura, T. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Kojima, S. [Science University of Tokyo, Chiba (Japan)

    2000-05-01

    Excessive active oxygen produced in vivo by various causes is toxic. Accumulation of oxidation injuries due to excessive active causes cell and tissue injuries, inducing various pathologic conditions such as aging and carcinogenesis. On the other hand, there are chemical defense mechanisms in the body that eliminate active oxygen or repair damaged molecules, defending against resultant injury. It is interesting reports that appropriate oxidation stress activate the chemical biological defense mechanisms. In this study, to elucidate these phenomena and its mechanism by low dose radiation, we studied on the below subjects. Activation of chemical biological defense mechanisms by low dose radiation: (1) The effects radiation on lipid peroxide (LPO) levels in the organs, membrane fluidity and the superoxide dismutase (SOD) activity were examined in rats and rabbits. Rats were irradiated with low dose X-ray over their entire bodies, and rabbits inhaled vaporized radon spring water, which primarily emitted {alpha}-ray. The following results were obtained. Unlike high dose X-ray, low dose X-ray and radon inhalation both reduced LPO levels and made the state of the SH-group on membrane-bound proteins closer to that of juvenile animals, although the sensitivity to radioactivity varied depending on the age of the animals and among different organs and tissues. The SOD activity was elevated, suggesting that low dose X-ray and radon both activate the host defensive function. Those changes were particularly marked in the organs related to immune functions of the animals which received low dose X-ray, while they were particularly marked in the brain after radon inhalation. It was also found that those changes continued for longer periods after low dose X-irradiation. (2) Since SOD is an enzyme that mediates the dismutation of O{sub 2}- to H{sub 2}O{sub 2}, the question as to whether the resultant H{sub 2}O{sub 2} is further detoxicated into H{sub 2}O and O{sub 2} or not must

  9. Activation of chemical biological defense mechanisms and remission of vital oxidative injury by low dose radiation

    International Nuclear Information System (INIS)

    Excessive active oxygen produced in vivo by various causes is toxic. Accumulation of oxidation injuries due to excessive active causes cell and tissue injuries, inducing various pathologic conditions such as aging and carcinogenesis. On the other hand, there are chemical defense mechanisms in the body that eliminate active oxygen or repair damaged molecules, defending against resultant injury. It is interesting reports that appropriate oxidation stress activate the chemical biological defense mechanisms. In this study, to elucidate these phenomena and its mechanism by low dose radiation, we studied on the below subjects. Activation of chemical biological defense mechanisms by low dose radiation: (1) The effects radiation on lipid peroxide (LPO) levels in the organs, membrane fluidity and the superoxide dismutase (SOD) activity were examined in rats and rabbits. Rats were irradiated with low dose X-ray over their entire bodies, and rabbits inhaled vaporized radon spring water, which primarily emitted α-ray. The following results were obtained. Unlike high dose X-ray, low dose X-ray and radon inhalation both reduced LPO levels and made the state of the SH-group on membrane-bound proteins closer to that of juvenile animals, although the sensitivity to radioactivity varied depending on the age of the animals and among different organs and tissues. The SOD activity was elevated, suggesting that low dose X-ray and radon both activate the host defensive function. Those changes were particularly marked in the organs related to immune functions of the animals which received low dose X-ray, while they were particularly marked in the brain after radon inhalation. It was also found that those changes continued for longer periods after low dose X-irradiation. (2) Since SOD is an enzyme that mediates the dismutation of O2- to H2O2, the question as to whether the resultant H2O2 is further detoxicated into H2O and O2 or not must still be evaluated. Hence, we studied the effect of

  10. Hypoxia tolerance and antioxidant defense system of juvenile jumbo squids in oxygen minimum zones

    Science.gov (United States)

    Trübenbach, Katja; Teixeira, Tatiana; Diniz, Mário; Rosa, Rui

    2013-10-01

    Jumbo squid (Dosidicus gigas) is a large oceanic squid endemic off the Eastern Tropical Pacific that undertakes diel vertical migrations into mesopelagic oxygen minimum zones. One of the expected physiological effects of such migration is the generation of reactive oxygen species (ROS) at the surface, promoted by the transition between hypoxia and reoxygenation states. The aim of this study was to investigate the energy expenditure rates and the antioxidant stress strategies of juvenile D. gigas under normoxia and hypoxia, namely by quantifying oxygen consumption rates, antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], heat shock protein expression (Hsp70/Hsc70), and lipid peroxidation [malondialdehyde (MDA) levels]. A high significant decrease (68%) in squid's metabolic rates was observed during hypoxia (pGST activity and MDA concentrations did not change significantly from normoxia to hypoxia (p>0.05), with the latter indicating no enhancement of lipid peroxidation (i.e. cellular damage) at the warmer and normoxic surface waters. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how this species is quickly responding to the impacts of environmental stressors coupled with global climate change.

  11. Phosphorous and sulfur nutrition modulate antioxidant defenses in Myracrodruom urundeuva plants exposed to arsenic.

    Science.gov (United States)

    Gomes, M P; Soares, A M; Garcia, Q S

    2014-07-15

    We investigated if plant nutrition and antioxidant system activation are correlated features of arsenic (As)-tolerance in Myracrodruom urundeuva. Plants were grown for 120 days in substrates with 0, 10, 50 and 100mg Askg(-1) and its As-tolerance was demonstrated. As-concentrations greater than 10mgkg(-1) decreased plant growth and photosynthesis but did not induce plant death. Plants coupled alterations in stomatal conductance and transpiration to avoid As-deleterious effects to the photosynthetic apparatus. As-toxicity in M. urundeuva was due to lipid peroxidation induced by hydrogen peroxide accumulation. Ascorbate peroxidase (APX) and gluthatione peroxidase (GPX) had central roles in hydrogen peroxide (H2O2) scavenging in leaves, and their activities were linked to changes in redox potentials (ascorbate and glutathione pools). APX and GPX inactivation/degeneration led to H2O2 accumulation and related lipid peroxidation. Increased phosphorus (P) and sulfur (S) concentrations in leaves were related to increased APX and GPX activities by stimulating increases in glutathione biosynthesis. We concluded that P and S nutrition were directly linked to As-tolerance in M. urundeuva plants by increasing antioxidant system activities. PMID:24866559

  12. Chromium-induced modulation in the antioxidant defense system during phenological growth stages of Indian mustard.

    Science.gov (United States)

    Diwan, Hema; Ahmad, Altaf; Iqbal, Muhammad

    2010-02-01

    Chromium-induced modulation in the enzymes and metabolites of antioxidants was investigated at various phenological stages of Indian mustard (Brassica juncea (L.) Czern. & Coss. cv Pusa Jai Kisan)], grown with various levels of chromium (Cr) in pots under natural environmental conditions. Chromium accumulation in the root, stem and leaves increased with the advancement in the age of the plants. Growth of Indian mustard was not affected significantly by the supply of Cr up to the levels of 400 mg kg(-1) soil. Activities of superoxide dismutase (SOD), ascorbate peroxide (APX), catalase (CAT), and glutathione reductase (GR) increased in the leaves of Cr-treated plants, when compared with control. High activities of antioxidant enzymes supported by high Cr concentrations in roots and aerial parts (except seeds) established the Indian mustard as a potential hyperaccumulator anda hypertolerant species to Cr stress. For this study, an edible crop was chosen intentionally so as to tap maximum benefit by remediating the contaminated site on one hand and getting uncontaminated seeds to raise the next generation, on the other. PMID:20734612

  13. Assessment of Defense Styles and Mechanisms in Iranian Patients Suffering from Obsessive Compulsive or Panic Disorders versus Normal Controls using Persian Version of Defense Style Questionnaire-40

    OpenAIRE

    Masoud Janbozorgi; Ali Reza Zahiroddin; Ruhollah Shabanpour; Padideh Ghaeli

    2012-01-01

    Objective: The aim of this study was to compare defense styles and mechanisms in adult patients suffering from obsessive-compulsive disorder (OCD), and panic disorder (PD) with normal subjects in Iran . Methods: Defensive patterns of 22 patients with OCD, 28 patients with PD and those of 116 normal individuals (as a control group) were assessed using the Farsi version of Defense Style Questionnaire-40 (DSQ-40). The content validity of this questionnaire was done prior to the initiation of the...

  14. Antioxidants

    Science.gov (United States)

    ... prevent or delay some types of cell damage. Antioxidants are found in many foods, including fruits and vegetables. They are also available ... t clear whether this is because of the antioxidants, something else in the foods, or other factors. High-dose supplements of antioxidants ...

  15. Differences in associations between markers of antioxidative defense and asthma are sex specific

    DEFF Research Database (Denmark)

    Malling, Tine Halsen; Sigsgaard, Torben; Andersen, Helle R;

    2010-01-01

    inflammatory lung diseases such as asthma. Sex-specific differences have been noted for asthma, which in postpubertal subjects is predominantly found in females. These sex-specific differences may be associated with differences on the molecular level as well. OBJECTIVE: The aim of this cross-sectional study...... as either current asthma symptoms with bronchial hyperresponsiveness (BHR) or a continuous asthma score based on 8 questions. RESULTS: A total of 1191 mostly white women and men (mean [SD] age, 34.0 [7.1] and 35.1 [7.1] years, respectively) were enrolled in the study. Current asthma symptoms were...... subjects (161 women, 134 men). Women had higher enzyme activities of most antioxidant enzymes (GPX, P = 0.006; GR, P < 0.001; and G6PD, P = 0.009) than did men. Although the serum selenium concentration was inversely associated with asthma in both sexes, there was a female preponderance, with 3.5% lower...

  16. Amelioration of Heat Stress Induced Disturbances of Antioxidant Defense System in Chicken by Brahma Rasayana

    Directory of Open Access Journals (Sweden)

    V. Ramnath

    2008-01-01

    Full Text Available Since the range of comfort zone or thermo neutral zone of domestic chickens is narrow, they become easily susceptible to heat and cold environmental stress. We evaluated Brahma Rasayana (BR supplementation on concentrations of certain oxidative stress markers associated with heat stress. A total of 48 egg type male chickens of local strain were divided into six groups (n = 8 for the study. Three groups were fed with BR orally at the rate of 2 g/kg bw daily for 10 days prior to and during the period of experiment. Two of the four groups that were exposed to heat stress (HST i.e. to a temperature of 40 ± 1°C and relative humidity of 80 ± 5% in an environmental chamber for 4 h daily for 5 or 10 days, received BR orally. The other two groups remained as BR treated and untreated non-heat stressed (NHST controls. There was a significant (P < 0.05 increase in the activities of antioxidant enzymes in blood such as catalase (CAT and superoxide dismutase (SOD, as well as liver CAT, glutathione peroxidase (GPX and glutathione reductase (GR in NHST-BR treated and HST-BR treated (both 5 and 10 days chickens when compared with untreated controls. A great deal of significant (P < 0.05 variations were seen in serum and liver reduced glutathione (GSH concentration in NHST-BR treated and HST-BR treated (both 5 and 10 days chickens. Serum and liver lipid peroxidation levels were found to be significantly (P < 0.05 higher in HST-untreated (both 5 and 10 days chickens when compared with other groups. Thus BR supplementation during HST brings about enhanced action of enzymatic and non-enzymatic antioxidants, which nullified the undesired side effects of free radicals that are generated during HST.

  17. Pistacia Atlantica Extract Enhances Exercise-Mediated Improvement of Antioxidant Defense in Vistar Rats

    Directory of Open Access Journals (Sweden)

    Parvin Farzanegi

    2014-07-01

    Full Text Available Exercise training causes increased oxidative stress. Pistacia Atlantica Extract (Mastic is known to have a protective effect against oxidative stress and inflammation. We examined the effects of exercise training with and without Pistacia Atlantica extract administration on antioxidant markers in vistar rats. Twenty-eight Vistar female rats (six to eight weeks old, 150-200 g weight allocated into training (n = 14 and control (n = 14 groups and further divided into saline + control (n = 7, saline + training (n = 7, mastic +control (n = 7, and mastic + raining (n = 7. The training groups were given exercise on a treadmill at 25 m/min (0% grade for 60 min/day, 5 days/week for eight weeks. Mastic groups were administered at a dose 100 mg/kg (7.5 μL/g of body weight, orally. Seventy-two hours after the last training session, the rats were sacrificed and their liver tissues were excised for tissue oxidative stress markers which were detected by ELISA method. Mastic, Exercise, and Exercise+ Mastic attenuated MDA compared to control (p<0.01. Exercise + Mastic showed a stronger suppressive effect than Mastic and exercise. Mastic and Exercise significantly the increase in SOD compared with control (p<0.05. Exercise + Mastic showed further additive effects on increasing SOD (p<0.001. These results suggest that Mastic supplementation and exercise alone induced positive adaptations in modulating oxidant and antioxidant levels without causing the reduced/oxidized glutathione ratio (GSH/GSSG in liver of vistar rats, but the combined intervention is more effective than either intervention alone.

  18. Contribution of Patient Defense Mechanisms and Therapist Interventions to the Development of Early Therapeutic Alliance in a Brief Psychodynamic Investigation

    OpenAIRE

    Despland, Jean-Nicolas; de Roten, Yves; Despars, Josée; Stigler, Michael; Perry, J. Christopher

    2001-01-01

    This preliminary study examined how patients' defense mechanisms and psychotherapists' techniques influence early alliance formation. The authors assessed the relationships among defense mechanisms, therapist interventions, and the development of alliance in a sample of 12 patients undergoing Brief Psychodynamic Investigation (4 sessions). Alliance development occurred rapidly and was clearly established by the third session. Neither defensive functioning nor supportive or exploratory interve...

  19. How does our brain constitute defense mechanisms? First-person neuroscience and psychoanalysis.

    Science.gov (United States)

    Northoff, Georg; Bermpohl, Felix; Schoeneich, Frank; Boeker, Heinz

    2007-01-01

    Current progress in the cognitive and affective neurosciences is constantly influencing the development of psychoanalytic theory and practice. However, despite the emerging dialogue between neuroscience and psychoanalysis, the neuronal processes underlying psychoanalytic constructs such as defense mechanisms remain unclear. One of the main problems in investigating the psychodynamic-neuronal relationship consists in systematically linking the individual contents of first-person subjective experience to third-person observation of neuronal states. We therefore introduced an appropriate methodological strategy, 'first-person neuroscience', which aims at developing methods for systematically linking first- and third-person data. The utility of first-person neuroscience can be demonstrated by the example of the defense mechanism of sensorimotor regression as paradigmatically observed in catatonia. Combined psychodynamic and imaging studies suggest that sensorimotor regression might be associated with dysfunction in the neural network including the orbitofrontal, the medial prefrontal and the premotor cortices. In general sensorimotor regression and other defense mechanisms are psychoanalytic constructs that are hypothesized to be complex emotional-cognitive constellations. In this paper we suggest that specific functional mechanisms which integrate neuronal activity across several brain regions (i.e. neuronal integration) are the physiological substrates of defense mechanisms. We conclude that first-person neuroscience could be an appropriate methodological strategy for opening the door to a better understanding of the neuronal processes of defense mechanisms and their modulation in psychoanalytic psychotherapy. PMID:17426413

  20. Studies on defense mechanism against xenobiotics in rats, using gold as a model

    International Nuclear Information System (INIS)

    For self-protection, a living organism has a special mechanism to prevent xenobiotics from being absorbed through the gastrointestinal tract. This led to the present study on the defense mechanism of the gastrointestinal tract where foods are digested and absorbed. The results obtained from this study showed that 1) starvation caused an insufficiency of the defense mechanism against xenobiotics in jejunal absorptive cells and Kupffer cells, 2) after refeeding diets, a reparative process occurred at the damaged cell sites, resulting in recovery of the defense mechanism against xenobiotics, and 3) a 5% fat diet seemed to be the best fat level for recovery of the defense mechanism against xenobiotics. In the nutritional point of view, the 5% fat diet is equivalent to 0.11 in fat energy ratio (fat energy/total energy of the diet). These data suggest that a diet with a much lower fat energy (equivalent to 0.11) can give a good effect on recovery of the defense mechanism against xenobiotics in the gastrointestinal tract and the liver. (author)

  1. Combined herbicide and saline stress differentially modulates hormonal regulation and antioxidant defense system in Oryza sativa cultivars.

    Science.gov (United States)

    Islam, Faisal; Ali, Basharat; Wang, Jian; Farooq, Muhammad A; Gill, Rafaqat A; Ali, Shafaqat; Wang, Danying; Zhou, Weijun

    2016-10-01

    Plants are simultaneously exposed to a combination of biotic and abiotic stresses in field conditions. Crops respond to the combined stress in a unique way which cannot be understood by extrapolating the results of individual stress. In the present study, effects of individual and combined stress of herbicide (2,4-dichlorophenoxyacetic acid) and salinity (NaCl) on two Oryza sativa cultivars (ZJ 88 and XS 134) were investigated. Both herbicide and saline stress affected the plant growth differentially and produced oxidative stress in rice cultivars. Interestingly, the combination of herbicide and salinity showed a significant protection to both rice cultivars by reducing ROS (H2O2, O2(-)) and lipid peroxidation through modulation of enzymatic (SOD, POD, CAT and APX) and non-enzymatic (TSP, sugars, phenolic and proline) antioxidants. In addition, active regulation of transcript levels of genes encoding Na(+) and K(+) (OsHKT1;5, OsLti6a,b, OsHKT2;1, OsSOS1, OsCNGC1, OsNHX1 and OsAKT1) transporter proteins reduced sodium and enhanced potassium accumulation under combined stress, resulted a better growth and ionic homeostasis in both rice cultivars. The production of ABA and IAA was significantly higher in cultivar XS 134 compared to cultivar ZJ 88 under control conditions. However, combined herbicide and saline stress enhanced the accumulation of phytohormones (IAA and ABA) and transcription of ethylene in cultivar ZJ 88, which might be one of the factors responsible for poor salt tolerance in sensitive cultivar. These findings indicated that herbicide application under saline stress confers tolerance to salinity in rice cultivars, likely by reducing oxidative damage, modulating mineral absorption, upgradation of antioxidant defense and by dynamic regulation of key genes involved in Na(+) and K(+) homeostasis in plants. PMID:27258572

  2. In Defense of a Heuristic Interpretation of Quantum Mechanics

    Science.gov (United States)

    Healy, Eamonn F.

    2010-01-01

    Although the presentation of quantum mechanics found in traditional textbooks is intellectually well founded, it suffers from a number of deficiencies. Specifically introducing quantum mechanics as a solution to the arcane dilemma, the ultraviolet catastrophe, does little to impress a nonscientific audience of the tremendous paradigmatic shift…

  3. Study of Defensive Methods and Mechanisms in Developmental, Emotional (Internalization), and Disruptive Behavior (Externalization) Disorders

    OpenAIRE

    2014-01-01

    We need to find a way for adaptation with inherent unpleasantness of being human condition and conflicts that it caused, as we did not fail. Methods that we used for adaptation are named defense. This research have performed with the aim of study and compare defensive mechanisms and methods of Developmental, Emotional (Internalization), and Disruptive behavior (Externalization) disorders. Method, sample of this research included 390 family that are by available sampling method are selected. T...

  4. Effects of triploidy induction on antioxidant defense status in rainbow trout (Oncorhynchus mykiss) during early development.

    Science.gov (United States)

    Taghipoor, Kaveh; Keyvanshokooh, Saeed; Salati, Amir Parviz; Pasha-Zanoosi, Hossein; Babaheydari, Samad Bahrami

    2016-08-01

    The objective of the present study was to examine the antioxidant status of rainbow trout (Oncorhynchus mykiss) during the early stages of development (fertilized egg, eyed egg, alevin and fry) as an effect of triploidy induction. Eggs and milt were taken from eight females and six males. After insemination, the eggs were incubated at 10°C for 10min. Half of the fertilized eggs were then subjected to heat-shock for 10min submerged in a 28°C water bath to induce triploidy. The remainder were incubated normally and used as diploid controls. Three batches of eggs were randomly selected from each group (control and heat-shocked) and were incubated at 10-11°C under the same environmental conditions in hatchery troughs until the fry stage. Triplicate samples of fertilized eggs from each experimental group were randomly selected 1.5h post-fertilization and at the eyed egg stage of development (18 days post-fertilization, dpf). At 27 dpf, triplicate samples of alevins were chosen from each group. Based on ploidy determination experiment performed on both groups, nine diploid and nine triploid fry (76 dpf) were also selected. The triploidy induction success rate was 87.1%. Vitamin C was in lesser concentrations in fertilized eggs and eyed eggs of the heat-shock treatment group as compared with eggs of the diploid group. Alevins of the heat-shock treatment group had a lower superoxide dismutase (SOD) activity than alevins of the diploid group. Glutathione peroxidase (GPx) level was greater in fertilized eggs and alevins of the heat-shock treatment group as compared to diploids. Catalse (CAT) activity was greater in fertilized eggs, alevins and fry of the heat-shock treatment group than those of the diploid group. Malondialdehyde (MDA), as an index of lipid peroxidation, was in greater concentration in fertilized eggs of the group that was heat-shocked, but it was lesser in alevins and fry of the group in which the eggs were heat-shocked as compared to diploid counterparts

  5. The Effect of a 12-Week Moderate Intensity Interval Training Program on the Antioxidant Defense Capability and Lipid Profile in Men Smoking Cigarettes or Hookah: A Cohort Study

    OpenAIRE

    Abdessalem Koubaa; Moez Triki; Hajer Trabelsi; Hamza Baati; Zouhair Sahnoun; Ahmed Hakim

    2015-01-01

    Aim. To examine the impact of interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah unable or unwilling to quit smoking. Methods. Thirty-five participants performed an interval training (2 : 1 work : rest ratio) 3 times a week for 12 weeks at an intensity of 70% of VO2max. All subjects were subjected to a biochemical test session before and after the training program. Results. The increase of total antioxidant status (TAS), gluta...

  6. Efficacy of a Low Dose of Estrogen on Antioxidant Defenses and Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Cristina Campos

    2014-01-01

    Full Text Available This study tested whether a low dose (40% less than the pharmacological dose of 17-β estradiol would be as effective as the pharmacological dose to improve cardiovascular parameters and decrease cardiac oxidative stress. Female Wistar rats (n=9/group were divided in three groups: (1 ovariectomized (Ovx, (2 ovariectomized animals treated for 21 days with low dose (LE; 0.2 mg, and (3 high dose (HE; 0.5 mg 17-β estradiol subcutaneously. Hemodynamic assessment and spectral analysis for evaluation of autonomic nervous system regulation were performed. Myocardial superoxide dismutase (SOD and catalase (CAT activities, redox ratio (GSH/GSSG, total radical-trapping antioxidant potential (TRAP, hydrogen peroxide, and superoxide anion concentrations were measured. HE and LE groups exhibited an improvement in hemodynamic function and heart rate variability. These changes were associated with an increase in the TRAP, GSH/GSSG, SOD, and CAT. A decrease in hydrogen peroxide and superoxide anion was also observed in the treated estrogen groups as compared to the Ovx group. Our results indicate that a low dose of estrogen is just as effective as a high dose into promoting cardiovascular function and reducing oxidative stress, thereby supporting the approach of using low dose of estrogen in clinical settings to minimize the risks associated with estrogen therapy.

  7. Prooxidative effects of aspartame on antioxidant defense status in erythrocytes of rats.

    Science.gov (United States)

    Prokic, Marko D; Paunovic, Milica G; Matic, Milos M; Djordjevic, Natasa Z; Ognjanovic, Branka I; Stajn, Andras S; Saicic, Zorica S

    2014-12-01

    Since aspartame (L-aspartyl-L-phenylalanine methyl ester, ASP) is one of the most widely used artificial sweeteners, the aim of the present study was to investigate its effects on serum glucose and lipid levels as well as its effects on oxidative/antioxidative status in erythrocytes of rats. The experiment included two groups of animals: the control group was administered with water only, while the experimental group was orally administered with ASP (40 mg/kg b.w.) daily, for a period of six weeks. When compared with the control group, the group administrated with ASP indicated higher values of serum glucose, cholesterol and triglycerides. Significantly increased concentrations of superoxide anion (O2 .-), hydrogen peroxide (H2O2), peroxynitrite (?N??-) and lipid peroxides (LPO) were recorded in the erythrocytes of ASP treated group in comparison to the control group. In the course of chronic ASP administration, the following was observed: the concentration of reduced glutathione (GSH) and the activity of catalase (CAT) increased. Thus, these findings suggest that long-term consumption of ASP leads to hyperglycemia and hyperlipidemia, as well as to oxidative stress in erythrocytes. PMID:25431414

  8. Prooxidative effects of aspartame on antioxidant defense status in erythrocytes of rats

    Indian Academy of Sciences (India)

    Marko D Prokić; Milica G Paunović; Miloš M Matić; Nataša Z Djordjević; Branka I Ognjanović; Andraš Š Štajn; Zorica S Saičić

    2014-12-01

    Since aspartame (L-aspartyl-L-phenylalanine methyl ester, ASP) is one of the most widely used artificial sweeteners, the aim of the present study was to investigate its effects on serum glucose and lipid levels as well as its effects on oxidative/antioxidative status in erythrocytes of rats. The experiment included two groups of animals: the control group was administered with water only, while the experimental group was orally administered with ASP (40 mg/kg b.w.) daily, for a period of six weeks. When compared with the control group, the group administrated with ASP indicated higher values of serum glucose, cholesterol and triglycerides. Significantly increased concentrations of superoxide anion (O2•−), hydrogen peroxide (H2O2), peroxynitrite (ОNОО−) and lipid peroxides (LPO) were recorded in the erythrocytes of ASP treated group in comparison to the control group. In the course of chronic ASP administration, the following was observed: the concentration of reduced glutathione (GSH) and the activity of catalase (CAT) increased. Thus, these findings suggest that long-term consumption of ASP leads to hyperglycemia and hyperlipidemia, as well as to oxidative stress in erythrocytes.

  9. Electrochemical Study of Antioxidant Regeneration Mechanisms – Application in Dermocosmetics

    OpenAIRE

    Barus, Carole; Wetz-Torond, Fabienne; Brunel, Yves; Gros, Pierre

    2012-01-01

    Oxidative stress is associated to the massive generation of reactive oxygen species inducing fast oxidative reactions in chain. To overcome this problem, reasonable supplementations of antioxidants are widely practiced, mostly based on empirical protocols. An electrochemical process is proposed to choose the best molecules association inducing the greatest antioxidant capacity, by coupling homogeneous or heterogeneous catalytic reactions involving antioxidants with an electrochemical step. Cy...

  10. Influence of Different Doses of Levofloxacin on Antioxidant Defense Systems and Markers of Renal and Hepatic Dysfunctions in Rats

    Directory of Open Access Journals (Sweden)

    Ebenezer Tunde Olayinka

    2015-01-01

    Full Text Available Levofloxacin (LFX is a broad spectrum fluoroquinolone antibiotic used in the treatment of infections such as pneumonia, chronic bronchitis, and sinusitis. The present study assessed the likely toxic effect of LFX on hepatic and renal tissues in rats. Twenty male Wistar rats were randomly divided into four treatment groups: A: control, B: 5 mg/kg bw LFX (half therapeutic dose, C: 10 mg/kg bw LFX (therapeutic dose, and D: 20 mg/kg bw LFX (double therapeutic dose. After seven days of administration, result indicated significant (P<0.05 increase in plasma ALT, AST, and ALP activities in the treated groups compared to control. Also, there was a significant increase in plasma creatinine, urea, and total bilirubin in the treated groups relative to control. Plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides also increased significantly in the treated groups relative to control. Also, hepatic MDA level increased significantly in all the treated groups. However, hepatic SOD, catalase, and GST activities were significantly reduced in the LFX-treated animals. Moreover, GSH and ascorbic acid levels were significantly decreased in the LFX-treated groups relative to control. In conclusion, three doses of levofloxacin depleted antioxidant defense system and induced oxidative stress and hepatic and renal dysfunctions in rats.

  11. Repeated exposures to roadside particulate matter extracts suppresses pulmonary defense mechanisms, resulting in lipid and protein oxidative damage.

    Science.gov (United States)

    Pardo, Michal; Porat, Ziv; Rudich, Assaf; Schauer, James J; Rudich, Yinon

    2016-03-01

    Exposure to particulate matter (PM) pollution in cities and urban canyons can be harmful to the exposed population. However, the underlying mechanisms that lead to health effects are not yet elucidated. It is postulated that exposure to repeated, small, environmentally relevant concentrations can affect lung homeostasis. This study examines the impact of repeated exposures to urban PM on mouse lungs with focus on inflammatory and oxidative stress parameters. Aqueous extracts from collected urban PM were administered to mice by 5 repeated intra-tracheal instillations (IT). Multiple exposures, led to an increase in cytokine levels in both bronchoalveolar lavage fluid and in the blood serum, indicating a systemic reaction. Lung mRNA levels of antioxidant/phase II detoxifying enzymes decreased by exposure to the PM extract, but not when metals were removed by chelation. Finally, disruption of lung tissue oxidant-inflammatory/defense balance was evidenced by increased levels of lipid and protein oxidation. Unlike response to a single IT exposure to the same dose and source of extract, multiple exposures result in lung oxidative damage and a systemic inflammatory reaction. These could be attributed to compromised capacity to activate the protective Nrf2 tissue defense system. It is suggested that water-soluble metals present in urban PM, potentially from break and tire wear, may constitute major drivers of the pulmonary and systemic responses to multiple exposure to urban PM. PMID:26735168

  12. The Comparison of Defense Mechanism Styles and Personality Characteristics in Addicts and Healthy Individuals

    Directory of Open Access Journals (Sweden)

    Mohsen Ahmadi

    2012-11-01

    Full Text Available Aim: The purpose of this study was to comprise of psychological defense mechanism styles and personality characteristics in addicts and healthy individuals. Method: In this causal-comparative study, 70 addicts person (with an average age of 37.29±9.81and the age range 23 to 58 years were selected via accessible sampling method of clinics and Hamadan’s addicted self-representing center during the Autumn of 2011, The number of 70 relatives of these people that demographic variables were matched as possible with the comparison group were selected. Both groups were asked to respond to the defense mechanism style and Eysenk personality Questionnaires. Results: The result of this study showed that the scores mean of addicts were higher than healthy people on immature defense mechanism style, neourotism, and neurotic and extraversion personality characteristics and lower than in mature defense style variables. Conclusion: Based on the result of this study there was a significant difference between addict individuals and healthy people in defense mechanism and personality characteristics.

  13. Nrf2/antioxidant defense pathway is involved in the neuroprotective effects of Sirt1 against focal cerebral ischemia in rats after hyperbaric oxygen preconditioning.

    Science.gov (United States)

    Xue, Fen; Huang, Jin-Wen; Ding, Pei-Yan; Zang, Hong-Gang; Kou, Zhi-Jian; Li, Ting; Fan, Juan; Peng, Zheng-Wu; Yan, Wen-Jun

    2016-08-01

    Sirtuin 1 (Sirt1) is a class III histone deacetylase involved in neuroprotection induced by hyperbaric oxygen preconditioning (HBO-PC) in animal models of ischemia. However, the underlying mechanisms remain to be illustrated. In the present study, rats exposed to middle cerebral artery occlusion (MCAO) were used to establish an ischemic stroke model. The infarct volume ratio, neurobehavioral score, and expressions of Sirt1, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and superoxide dismutase 1 (SOD1) were evaluated at 7 days after reperfusion, and the level of malondialdehyde (MDA) was used to assess oxidative stress. HBO-PC increased the expression of Sirt1 and reduced infarct volume ratio and neurobehavioral deficit in MCAO rats. Meanwhile, HBO-PC also increased expression of Nrf2, HO-1, and SOD1 and decreased MDA content. Furthermore, either Sirt1 or Nrf2 knockdown by short interfering RNA (siRNA) inhibited the expression of Nrf2, HO-1, and SOD1 and eliminated the neuroprotective effects of HBO-PC. Taken together, the results suggest that the Nrf2/antioxidant defense pathway is involved in the long lasting neuroprotective effects of Sirt1 induced by HBO-PC against transient focal cerebral ischemia. PMID:27131779

  14. Changes in Antioxidant Defense Capability and Lipid Profile after 12-Week Low- Intensity Continuous Training in Both Cigarette and Hookah Smokers: A Follow-Up Study

    OpenAIRE

    Koubaa, Abdessalem; Triki, Moez; Trabelsi, Hajer; Masmoudi, Liwa; Sahnoun, Zouhair; Hakim, Ahmed

    2015-01-01

    To examine the impact of low-intensity continuous training program on antioxidant defense capability and lipid profile in male cigarette or hookah smokers. Forty-three male adults participated in a 12-week continuous training program at an intensity of 40% of VO2max. All subjects were subjected to anthropometric, physical and biochemical tests before and after the training program. The increase of Glutathione reductase (GR) and Superoxide dismutase (SOD) is significant only for cigarette smok...

  15. Hydrogen-Rich Water Intake Accelerates Oral Palatal Wound Healing via Activation of the Nrf2/Antioxidant Defense Pathways in a Rat Model

    OpenAIRE

    Naofumi Tamaki; Rita Cristina Orihuela-Campos; Makoto Fukui; Hiro-O Ito

    2016-01-01

    The wound healing process attempts to restore the integrity and function of the injured tissue. Additionally, proinflammatory cytokines, growth factors, and oxidative stress play important roles in wound healing. The aim of this study was to determine whether hydrogen-rich water intake induces the activation of the Nrf2/antioxidant defense pathway in rat palatal tissue, thereby reducing systemic oxidative stress and proinflammatory cytokine levels and promoting healing-associated genes. A cir...

  16. Leach mechanisms of borosilicate glass Defense Waste Forms - effects of composition

    International Nuclear Information System (INIS)

    The study described below concerns the mechanisms which control the leaching of two Defense Wasteforms, viz. SRL TDS-131 glass and MCC Defense Waste Reference Glass. It is shown that both the leach mechanisms and the structure of the leached surface are strongly dependent not only on the composition of the leachant and the contact time between the leachant and the glass but also on the exact composition of the glass. The relatively minor differences in composition between the two glasses investigated here were observed to give rise to large differences in leach behavior, in particular upon prolonged contact with water, rather than to limited changes in leach rate alone

  17. Improvement of phytoextraction and antioxidative defense in Solanum nigrum L. under cadmium stress by application of cadmium-resistant strain and citric acid

    International Nuclear Information System (INIS)

    Remediation of plant-microorganism-chelates synergy has been proposed as an effective remediation method for enhancing the removal efficiency of heavy metal. Manipulation of the antioxidative system increases plant tolerance, thereby potentially enhancing the uptake capacity to heavy metal. In this study, we investigated the possibility of improving the phytoextraction of Cd and the antioxidative defense of Solanum nigrum L. by application of a new isolated strain (Paecilomyces lilacinus NH1) (PLNH1) and citric acid (CA). The results showed that application of CA or PLNH1 significantly promoted S. nigrum's growth under Cd stress, but the synergistic effect of CA and PLNH1 on S. nigrum's growth was more obvious. The coexistence of CA and PLNH1 could enhance about 30% of Cd accumulation in different organs of S. nigrum compared to the treatment without the addition of CA and PLNH1, whereas single CA or PLNH1 added treatment only enhanced about 10-15% of Cd accumulation in different organs of S. nigrum. The antioxidative defense in S. nigrum under Cd stress was significantly improved as result of application of CA and PLNH1. The responses of antioxidative enzymes to Cd stress significantly decreased following application of CA and PLNH1, and the oxidative stress experienced by the plant due to Cd in the soil was significantly alleviated.

  18. Improvement of phytoextraction and antioxidative defense in Solanum nigrum L. under cadmium stress by application of cadmium-resistant strain and citric acid

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yang, E-mail: gaoyang0898@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai, 200240 (China); Key Laboratory of Soil and Water Conservation and Desertification Control, College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083 (China); Miao Chiyuan [Department of Environmental Engineering, Peking University, Beijing, 100871 (China); Mao Liang [School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai, 200240 (China); School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240 (China); Zhou Pei [School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240 (China); Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240 (China); Jin Zhiguo; Shi Wanjun [School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240 (China)

    2010-09-15

    Remediation of plant-microorganism-chelates synergy has been proposed as an effective remediation method for enhancing the removal efficiency of heavy metal. Manipulation of the antioxidative system increases plant tolerance, thereby potentially enhancing the uptake capacity to heavy metal. In this study, we investigated the possibility of improving the phytoextraction of Cd and the antioxidative defense of Solanum nigrum L. by application of a new isolated strain (Paecilomyces lilacinus NH1) (PLNH1) and citric acid (CA). The results showed that application of CA or PLNH1 significantly promoted S. nigrum's growth under Cd stress, but the synergistic effect of CA and PLNH1 on S. nigrum's growth was more obvious. The coexistence of CA and PLNH1 could enhance about 30% of Cd accumulation in different organs of S. nigrum compared to the treatment without the addition of CA and PLNH1, whereas single CA or PLNH1 added treatment only enhanced about 10-15% of Cd accumulation in different organs of S. nigrum. The antioxidative defense in S. nigrum under Cd stress was significantly improved as result of application of CA and PLNH1. The responses of antioxidative enzymes to Cd stress significantly decreased following application of CA and PLNH1, and the oxidative stress experienced by the plant due to Cd in the soil was significantly alleviated.

  19. A quorum-sensing-induced bacteriophage defense mechanism

    DEFF Research Database (Denmark)

    Høyland-Kroghsbo, Nina Molin; Mærkedahl, Rasmus Baadsgaard; Svenningsen, Sine

    2013-01-01

    . Specifically, E. coli reduces the numbers of ¿ receptors on the cell surface in response to N-acyl-l-homoserine lactone (AHL) quorum-sensing signals, causing a 2-fold reduction in the phage adsorption rate. The modest reduction in phage adsorption rate leads to a dramatic increase in the frequency of...... sensing plays an important role in determining the susceptibility of E. coli to infection by bacteriophages ¿ and ¿. On the basis of our findings in the classical Escherichia coli-¿ model system, we suggest that quorum sensing may serve as a general strategy to protect bacteria specifically under...... uninfected survivor cells after a potent attack by virulent phages. Notably, this mechanism may apply to a broader range of phages, as AHLs also reduce the risk of ¿ phage infection through a different receptor. IMPORTANCE To enable the successful manipulation of bacterial populations, a comprehensive...

  20. 6-Benzylaminopurine inhibits growth of Monilinia fructicola and induces defense-related mechanism in peach fruit.

    Science.gov (United States)

    Zhang, Yangyang; Zeng, Lizhen; Yang, Jiali; Zheng, Xiaodong; Yu, Ting

    2015-11-15

    This study demonstrated the inhibitory effect of 6-benzylaminopurine (BAP), the first generation synthetic cytokinin, on the invasion of Monilinia fructicola in peach fruit and the possible mechanism involved for the first time. Our results suggested that BAP treatment had a 63% lower disease incidence and approximately 10 times lower lesion diameter compared to the control throughout the incubation period. In vitro BAP showed a direct inhibitory effect on M. fructicola spore germination. BAP could prevent fruit texture deterioration and protect the cell membrane from oxidative stress, while no adverse effects were observed on fruit quality maintenance. Analysis of defense-related enzymes activities indicated that the use of BAP induced higher specific polyphenol oxidase and peroxidase activities which triggered stronger host defensive responses. Thus, our results verified the proposed mechanism of BAP in controlling M. fructicola by direct inhibitory effect, delay peach senescence and activation of defensive enzymes. PMID:25977018

  1. Modulation of exogenous glutathione in antioxidant defense system against Cd stress in the two barley genotypes differing in Cd tolerance.

    Science.gov (United States)

    Chen, Fei; Wang, Fang; Wu, Feibo; Mao, Weihua; Zhang, Guoping; Zhou, Meixue

    2010-08-01

    Soil cadmium (Cd) contamination has posed a serious problem for safe food production and become a potential agricultural and environmental hazard worldwide. Greenhouse hydroponic experiments were conducted to investigate the modulation of exogenous GSH (reduced glutathione) in antioxidant defense system against the Cd-induced toxicity in plants exposed to 5 muM Cd using two barley genotypes differing in Cd tolerance. Addition of 20 mg L(-1) GSH in 5 muM Cd culture medium significantly alleviated Cd-induced growth inhibition, especially for the sensitive genotype Dong 17 and dramatically depressed O(2)(-), H(2)O(2) and malondialdehyde (MDA) accumulation. GSH mediated intracellular GSH content to keep the level over the control especially in the case of Cd-induced GSH reduction. External GSH counteracted Cd-induced alterations of certain antioxidant enzymes, e.g. brought root dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and glutathione peroxidase (GPX) activities of the both genotypes down towards the control level, but elevated the depressed ascorbate peroxidase (APX) and catalase (CAT) activities in Dong 17 after 10-15 d treatment. The examination of APX and superoxide dismutase (SOD) isoenzymes revealed GSH significantly increased MnSOD, sAPX and tAPX activities in the both genotypes, and strongly stimulated Cd-induced decrease in cAPX in the sensitive genotype. Furthermore, External GSH up-regulated root cAPX and leaf cAPX, CAT1, and CAT2 expression at transcript level in Dong 17 to achieve stimulation. These data, especially from the results of depressed O(2)(-), H(2)O(2) and MDA accumulation and elevated Cd-induced decrease in GSH content and APX (strongly stimulated cAPX, sAPX and tAPX) and CAT activities by GSH addition in the sensitive genotype, suggest that elevated intracellular GSH and stimulated APX (especially cAPX, sAPX and tAPX iosenzymes) and CAT activities, when concerning ROS scavenging systems, play an important role

  2. The role of tumor suppressor p53 in the antioxidant defense and metabolism

    OpenAIRE

    Budanov, Andrei V.

    2014-01-01

    Tumor suppressor p53 is inactivated in most cancers and the critical role of p53 in the suppression of carcinogenesis has been confirmed in many mouse models. The protein product of the tumor suppressor p53 gene works as a transcriptional regulator, activating expression of numerous genes involved in cell death, cell cycle arrest, senescence, DNA-repair and many other processes. In spite of the multiple efforts to characterize the functions of p53, the mechanisms of tumor suppression by p53 a...

  3. Cytotoxic effects of zearalenone and its metabolites and antioxidant cell defense in CHO-K1 cells.

    Science.gov (United States)

    Tatay, Elena; Font, Guillermina; Ruiz, Maria-Jose

    2016-10-01

    Zearalenone (ZEA) and its metabolites (α-zearalenol; α-ZOL, β-zearalenol; β-ZOL) are secondary metabolites of Fusarium fungi that produce cell injury. The present study explores mycotoxin-induced cell damage and cellular protection mechanisms in CHO-K1 cells. Cytotoxicity has been determined by reactive oxygen species (ROS) production and DNA damage. ROS production was determined using the fluorescein assay and DNA strand breakage by comet assay. Intracellular protection systems were glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD). The results demonstrated that all mycotoxins increased the ROS levels up to 5.3-fold the control levels in CHO-K1 cells. Zearalenone metabolites, but not ZEA, increased DNA damage 43% (α-ZOL) and 28% (β-ZOL) compared to control cells. The GSH levels decreased from 18% to 36%. The GPx and SOD activities respectively increased from 26% to 62% and from 23% to 69% in CHO-K1 cells, whereas CAT activity decreased from 14% to 52%. In addition, intracellular ROS production was induced by ZEA and its metabolites. The endogenous antioxidant system components GSH, GPx and SOD were activated against ZEA and its metabolites. These antioxidant system components thus could contribute to decrease cell injury by ZEA and its metabolites. PMID:27465603

  4. Butyrate attenuates lipopolysaccharide-induced inflammation in intestinal cells and Crohn's mucosa through modulation of antioxidant defense machinery.

    Science.gov (United States)

    Russo, Ilaria; Luciani, Alessandro; De Cicco, Paola; Troncone, Edoardo; Ciacci, Carolina

    2012-01-01

    Oxidative stress plays an important role in the pathogenesis of inflammatory bowel disease (IBD), including Crohn's disease (CrD). High levels of Reactive Oxygen Species (ROS) induce the activation of the redox-sensitive nuclear transcription factor kappa-B (NF-κB), which in turn triggers the inflammatory mediators. Butyrate decreases pro-inflammatory cytokine expression by the lamina propria mononuclear cells in CrD patients via inhibition of NF-κB activation, but how it reduces inflammation is still unclear. We suggest that butyrate controls ROS mediated NF-κB activation and thus mucosal inflammation in intestinal epithelial cells and in CrD colonic mucosa by triggering intracellular antioxidant defense systems. Intestinal epithelial Caco-2 cells and colonic mucosa from 14 patients with CrD and 12 controls were challenged with or without lipopolysaccaride from Escherichia coli (EC-LPS) in presence or absence of butyrate for 4 and 24 h. The effects of butyrate on oxidative stress, p42/44 MAP kinase phosphorylation, p65-NF-κB activation and mucosal inflammation were investigated by real time PCR, western blot and confocal microscopy. Our results suggest that EC-LPS challenge induces a decrease in Gluthation-S-Transferase-alpha (GSTA1/A2) mRNA levels, protein expression and catalytic activity; enhanced levels of ROS induced by EC-LPS challenge mediates p65-NF-κB activation and inflammatory response in Caco-2 cells and in CrD colonic mucosa. Furthermore butyrate treatment was seen to restore GSTA1/A2 mRNA levels, protein expression and catalytic activity and to control NF-κB activation, COX-2, ICAM-1 and the release of pro-inflammatory cytokine. In conclusion, butyrate rescues the redox machinery and controls the intracellular ROS balance thus switching off EC-LPS induced inflammatory response in intestinal epithelial cells and in CrD colonic mucosa. PMID:22412931

  5. Role of garlic oil and selenium as stimulators to some antioxidant defense system in irradiated male rats

    International Nuclear Information System (INIS)

    The increased level of lipid peroxide product; malondialdehyde (MDA) in various tissues of irradiated animals, may play a crucial role in damaging effects of exposure to ionizing radiation mediated by reactive free radicals generation. The protective efficiency of oral administration of garlic oil (500 mg/kg b.wt) three times weekly together with a single intraperitoneal injection of selenium (0.5 mg/kg b.wt) weekly for two weeks was examined on some antioxidant defense system as well as ultrastructural study in rats subjected to fractionated doses of gamma radiation up to a dose level of 6 Gy (1.5 Gy day after day). Exposure to gamma radiation induced a significant elevation in the level of malondialdehyde in plasma and liver and non-significant change was observed in superoxide dismutase activity (SOD). Also a significant increase was occurred in hepatic glutathione (GSH) content and glutathione peroxidase (GSHPx) activity. The pretreatment of irradiated rats with garlic oil and selenium caused a significant decrease in elevated level of MDA and a significant increase in the activity of SOD, GSHPx and GSH contents in both blood and liver. Concerning the ultrastructure studies, liver of irradiated rats showed abnormal shape of nucleus and nucleus membrane, swollen mitochondria with ruptured cristae, rupture of endoplasmic reticulum and vaculated cytoplasm, while intestine of irradiated rats exhibited deformed, shortened and abnormal structure of microvilli, accumulation of nuclear chromatin and dilatation of terminal web layer. In group of rats treated with garlic oil and selenium before exposure to gamma radiation, noticeable amelioration in ultrastructure changes of liver and intestine induced by irradiation was observed indicating a beneficial radioprotective role of both garlic oil and selenium

  6. Brief Report: The Defense Mechanisms of Homophobic Adolescent Males--A Descriptive Discriminant Analysis

    Science.gov (United States)

    Lewis, Andrew J.; White, Jennifer

    2009-01-01

    The study examined the role of defense mechanisms in homophobic attitudes of older male adolescents aged 17-18 years. A cross-sectional survey collected data from final year high school students (N = 86) attending an all male school in a regional centre in Victoria, Australia. The school was identified by teachers as having a problematic culture…

  7. Effects of Sex, Social Desirability, and Birth Order on the Defense Mechanisms Inventory.

    Science.gov (United States)

    Dudley, Gary E.

    1978-01-01

    Investigated effects of sex difference, social desirability instructions, and birth order of respondents on defense mechanisms inventory (DMI). Sex difference was found in projection only. Social desirability effects were found in turning-against-others, projection, principalization, and reversal. Thus, an interpretive caution is in order…

  8. Projective Identification as a Defense Mechanism in Group Counseling and Therapy.

    Science.gov (United States)

    Clark, Arthur J.

    1997-01-01

    Examines theoretical aspects of projective identification and suggests procedures for processing projective identification in group counseling and therapy. Discusses projective identification and related defense mechanisms, systems and boundaries, and scapegoating. Some of the stages in processing projective identification include the relationship…

  9. DNA DAMAGE REPAIR AND CELL CYCLE CONTROL: A NATURAL BIO-DEFENSE MECHANISM

    Science.gov (United States)

    DNA DAMAGE REPAIR AND CELL CYCLE CONTROL: A natural bio-defense mechanismAnuradha Mudipalli.Maintenance of genetic information, including the correct sequence of nucleotides in DNA, is essential for replication, gene expression, and protein synthesis. DNA lesions onto...

  10. Learning to Recognize Ego Defense Mechanisms: Results of a Structured Teaching Experience for Psychiatric Residents

    Science.gov (United States)

    Beresford, Thomas P.

    2005-01-01

    Objective: Ego defense mechanism (EDM) recognition can offer a powerful and practical tool in clinical psychiatry. However, recognition skill learning can be difficult to assess and may account for the lack of formal EDM recognition training in residency courses. Method: This study hypothesized that mean test scores would increase significantly…

  11. Effects of molybdenum on water utilization, antioxidative defense system and osmotic-adjustment ability in winter wheat (Triticum aestivum) under drought stress.

    Science.gov (United States)

    Wu, Songwei; Hu, Chengxiao; Tan, Qiling; Nie, Zhaojun; Sun, Xuecheng

    2014-10-01

    Molybdenum (Mo), as an essential trace element in plants, plays an essential role in abiotic stress tolerance of plants. To obtain a better understanding of drought tolerance enhanced by Mo, a hydroponic trial was conducted to investigate the effects of Mo on water utilization, antioxidant enzymes, non-enzymatic antioxidants, and osmotic-adjustment products in the Mo-efficient '97003' and Mo-inefficient '97014' under PEG simulated drought stress. Our results indicate that Mo application significantly enhanced Pn, chlorophyll, dry matter, grain yield, biomass, RWC and WUE and decreased Tr, Gs and water loss of wheat under drought stress, suggesting that Mo application improved the water utilization capacity in wheat. The activities of antioxidant enzymes such as superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and the contents of non-enzymatic antioxidants content such as ascorbic acid, reduced glutathione, carotenoid were significantly increased and malonaldehyde contents were decreased by Mo application under PEG simulated drought stress, suggesting that Mo application enhanced the ability of scavenging active oxygen species. The osmotic-adjustment products such as soluble protein, proline and soluble sugar were also increased by Mo application under PEG simulated drought stress, indicating that Mo improved the osmotic adjustment ability in wheat. It is hypothesized that Mo application might improve the drought tolerance of wheat by enhancing water utilization capability and the abilities of antioxidative defense and osmotic adjustment. Similarities and differences between the Mo-efficient and Mo-inefficient cultivars wheat in response to Mo under drought stress are discussed. PMID:25221925

  12. Psychogenic non-epileptic seizures: so-called psychiatric comorbidity and underlying defense mechanisms

    Directory of Open Access Journals (Sweden)

    Beghi M

    2015-09-01

    Full Text Available Massimiliano Beghi,1,2 Paola Beffa Negrini,1 Cecilia Perin,1,3 Federica Peroni,1,3 Adriana Magaudda,4 Cesare Cerri,1,3 Cesare Maria Cornaggia1,3 1Department of Surgery and Translational Medicine, University of Milano-Bicocca, 2Department of Mental Health, “Guido Salvini” Hospital, Garbagnate Milanese, Milan, Italy; 3Rehabilitation Medicine, Istituti Clinici Zucchi, Carate Brianza, Monza and Brianza, Italy; 4Epilepsy Center, Department of Neuroscience, University of Messina, Messina, Italy Abstract: In Diagnostic and Statistical Manual of Mental Disorders, fifth edition, psychogenic non-epileptic seizures (PNES do not have a unique classification as they can be found within different categories: conversion, dissociative, and somatization disorders. The ICD-10, instead, considers PNES within dissociative disorders, merging the dissociative disorders and conversion disorders, although the underlying defense mechanisms are different. The literature data show that PNES are associated with cluster B (mainly borderline personality disorders and/or to people with depressive or anxiety disorders. Defense mechanisms in patients with PNES with a prevalence of anxious/depressive symptoms are of “neurotic” type; their goal is to lead to a “split”, either vertical (dissociation or horizontal (repression. The majority of patients with this type of PNES have alexithymia traits, meaning that they had difficulties in feeling or perceiving emotions. In subjects where PNES are associated with a borderline personality, in which the symbolic function is lost, the defense mechanisms are of a more archaic nature (denial. PNES with different underlying defense mechanisms have different prognoses (despite similar severity of PNES and need usually a different treatment (pharmacological or psychological. Thus, it appears superfluous to talk about psychiatric comorbidity, since PNES are a different symptomatic expression of specific psychiatric disorders

  13. Gregarious pupation act as a defensive mechanism against cannibalism and intraguild predation.

    Science.gov (United States)

    Roberge, Claudia; Fréchette, Bruno; Labrie, Geneviève; Dumont, François; Lucas, Eric

    2016-08-01

    Coccinellid pupae use an array of defensive strategies against their natural enemies. This study aims to assess the efficiency of gregarious pupation as a defensive mechanism against intraguild predators and cannibals in coccinellid. The study was designed specifically (i) to determine the natural occurrence of gregarious pupation in the field for different coccinellid species, and (ii) to evaluate the adaptive value of gregarious pupation as a defensive mechanism against 2 types of predators (i.e., cannibals and intraguild predators). In the field, gregarious pupation consisted of a group of 2-5 pupae. The proportion of gregarious pupation observed varied according to species, the highest rate being observed with Harmonia axyridis Pallas (Coccinellidae; 14.17%). Gregarious pupation had no impact on the probability that intraguild predators and cannibals locate pupae. Intraguild predation occurred more often in site with gregarious pupation, while cannibalism occurred as often in site with gregarious pupation as in site with isolated pupa. However, for a specific pupa, the mortality rate was higher for isolated pupae than for pupae located in a gregarious pupation site both in the presence of intraguild predators and in the presence of cannibals. The spatial location of pupae within the group had no impact on mortality rate. Since it reduces the risk of predation, it is proposed that gregarious pupation act as a defensive mechanism for H. axyridis pupae. PMID:25684624

  14. Confronting actual influence of radiation on human bodies and biological defense mechanism

    International Nuclear Information System (INIS)

    After the accident at Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, social, economical, psychological pressures on local residents and fears of radiation among the general public have not been resolved. Based on the assumption that the negligence of specialists to clearly explain the influence of radiation on human bodies to the general public is the factor for above mentioned pressures and fears, the influence of radiation from a realistic view was discussed. The topics covered are: (1) understanding the meaning of radiation regulation, (2) radiation and threshold values, (3) actual influence of low-dose radiation, (4) chemical and biological defense in defense mechanism against radiation, (5) problems raised by Fukushima Daiichi nuclear accident. Furthermore, the article explains the principles and the applications of biological defense function activation, and suggested that self-help efforts to fight against stress are from now on. (S.K.)

  15. Hydrogen-Rich Water Intake Accelerates Oral Palatal Wound Healing via Activation of the Nrf2/Antioxidant Defense Pathways in a Rat Model.

    Science.gov (United States)

    Tamaki, Naofumi; Orihuela-Campos, Rita Cristina; Fukui, Makoto; Ito, Hiro-O

    2016-01-01

    The wound healing process attempts to restore the integrity and function of the injured tissue. Additionally, proinflammatory cytokines, growth factors, and oxidative stress play important roles in wound healing. The aim of this study was to determine whether hydrogen-rich water intake induces the activation of the Nrf2/antioxidant defense pathway in rat palatal tissue, thereby reducing systemic oxidative stress and proinflammatory cytokine levels and promoting healing-associated genes. A circular excisional wound was created in the oral palatal region, and the wound healing process was observed. The rats were divided into two experimental groups in which either hydrogen-rich water or distilled water was consumed. In the drinking hydrogen-rich water, the palatal wound healing process was accelerated compared to that in the control group. As molecular hydrogen upregulated the Nrf2 pathway, systemic oxidative stresses were decreased by the activation of antioxidant activity. Furthermore, hydrogen-rich water intake reduced proinflammatory cytokine levels and promoted the expression of healing-associated factors in rat palatal tissue. In conclusion, hydrogen-rich water intake exhibited multiple beneficial effects through activation of the Nrf2/antioxidant defense pathway. The results of this study support the hypothesis that oral administration of hydrogen-rich water benefits the wound healing process by decreasing oxidative stress and inflammatory responses. PMID:26798423

  16. Calcium Mitigates Arsenic Toxicity in Rice Seedlings by Reducing Arsenic Uptake and Modulating the Antioxidant Defense and Glyoxalase Systems and Stress Markers

    Directory of Open Access Journals (Sweden)

    Anisur Rahman

    2015-01-01

    Full Text Available The effect of exogenous calcium (Ca on hydroponically grown rice seedlings was studied under arsenic (As stress by investigating the antioxidant and glyoxalase systems. Fourteen-day-old rice (Oryza sativa L. cv. BRRI dhan29 seedlings were exposed to 0.5 and 1 mM Na2HAsO4 alone and in combination with 10 mM CaCl2 (Ca for 5 days. Both levels of As caused growth inhibition, chlorosis, reduced leaf RWC, and increased As accumulation in the rice seedlings. Both doses of As in growth medium induced oxidative stress through overproduction of reactive oxygen species (ROS by disrupting the antioxidant defense and glyoxalase systems. Exogenous application of Ca along with both levels of As significantly decreased As accumulation and restored plant growth and water loss. Calcium supplementation in the As-exposed rice seedlings reduced ROS production, increased ascorbate (AsA content, and increased the activities of monodehydroascorbate reductase (MDHAR, dehydroascorbate reductase (DHAR, catalase (CAT, glutathione peroxidase (GPX, superoxide dismutase (SOD, and the glyoxalase I (Gly I and glyoxalase II (Gly II enzymes compared with seedlings exposed to As only. These results suggest that Ca supplementation improves rice seedlings tolerance to As-induced oxidative stress by reducing As uptake, enhancing their antioxidant defense and glyoxalase systems, and also improving growth and physiological condition.

  17. Assessment of Defense Styles and Mechanisms in Iranian Patients Suffering from Obsessive Compulsive or Panic Disorders Versus Normal Controls Using Persian Version of Defense Style Questionnaire-40

    Directory of Open Access Journals (Sweden)

    Masoud Janbozorgi

    2012-04-01

    Full Text Available Objective: The aim of this study was to compare defense styles and mechanisms in adult patients suffering from obsessive-compulsive disorder (OCD, and panic disorder (PD with normal subjects in Iran . Methods: Defensive patterns of 22 patients with OCD, 28 patients with PD and those of 116 normal individuals (as a control group were assessed using the Farsi version of Defense Style Questionnaire-40 (DSQ-40. The content validity of this questionnaire was done prior to the initiation of the present study. Results: Both groups of patients with OCD or PD used more immature and less mature styles compared to the control group. No significant difference was observed in the use of neurotic style between the two groups . Conclusion: It is suggested that immature defenses may have an important role in the pathogenesis of OCD and PD.

  18. Antioxidant Activity and Mechanism of Protocatechuic Acid in vitro

    OpenAIRE

    Shuzhi Chen; Xiaozhen Wang; Xican Li; Dongfeng Chen

    2011-01-01

    Background: Protocatechuic acid (PCA) is a natural phenolic acid widely distributed in plantsand is considered as an active component of some traditional Chinese herbal medicines such as Cibotium barometz (L.) J.Sm, Stenoloma chusanum (L.) Ching, Ilex chinensis Sims. PCA was reported to possess various pharmacological effects which may be closely correlated with its antioxidant activities. However, the antioxidant of PCA has not been investigatedsystematically yet. Methods: In the study,...

  19. Antioxidant ability and mechanism of rhizoma Atractylodes macrocephala.

    Science.gov (United States)

    Li, Xican; Lin, Jian; Han, Weijuan; Mai, Wenqiong; Wang, Li; Li, Qiang; Lin, Miaofang; Bai, Mingsong; Zhang, Lishan; Chen, Dongfeng

    2012-01-01

    Rhizoma Atractylodes macrocephala (AM) has been used in Traditional Chinese Medicine (TCM) for about 2,000 years. In the study, we firstly determined the antioxidant levels of five AM extracts by •OH-scavenging, •O2−-scavenging, Fe2+-chelating, Cu2+-chelating, DPPH·-scavenging, and ABTS+·-scavenging assays. After measurement of the chemical contents in five AM extracts, we quantitatively analyzed the correlations between antioxidant levels and chemical contents. It was observed that total phenolics and total flavonoids had significant positive correlations with antioxidant levels (R = 0.685 and 0.479, respectively). In contrast, total sugars and total saponins presented lower correlations with antioxidant levels (R=−0.272 and 0.244, respectively). It means that antioxidant activity of AM should be attributed to total phenolics (including phenolic acids and flavonoids), and not total sugars and total saponins. Further analysis indicated that phenolic acids exhibited higher R values with radical-scavenging assays (R=0.32–1.00), while flavonoids showed higher R values with metal-chelating assays (R=0.86 and 0.90). In conclusion, AM exerts its antioxidant effect through metal-chelating, and radical-scavenging which is via donating hydrogen atom and donating electron. Its metal-chelating may result from flavonoids, while its radical-scavenging can be attributed to phenolic acids, especially caffeic acid, ferulic acid, and protocatechuic acid. PMID:23149564

  20. The 6-a-day study: effects of fruit and vegetables on markers of oxidative stress and antioxidative defense in healthy nonsmokers

    DEFF Research Database (Denmark)

    Dragsted, Lars Ove; Pedersen, A.; Hermetter, A.; Basu, S.; Hansen, Max; Ravn-Haren, Gitte; Kall, M.; Breinholt, V.; Castenmiller, J. J. M.; Stagsted, J.; Jakobsen, Jette; Skibsted, L.; Rasmussen, Salka E.; Loft, S.; Sandstrom, B.

    2004-01-01

    and vegetables/d; the placebo group received a placebo pill, and the supplement group received a vitamin pill designed to contain vitamins and minerals corresponding to those in 600 g fruit and vegetables. Biomarkers of oxidative damage to protein and lipids and of antioxidant nutrients and defense......Background: Fruit and vegetables contain both nutritive and nonnutritive factors that might contribute to redox (antioxidant and prooxidant) actions. Objective: We investigated the relative influence of nutritive and nonnutritive factors in fruit and vegetables on oxidative damage and enzymatic...... enzymes were determined before and during intervention. Results: Plasma lipid oxidation lag times increased during intervention in the Fruveg and supplement groups, and the increase was significantly higher in the former. Plasma protein carbonyl formation at lysine residues also increased in both of these...

  1. OsDMI3 Is a Novel Component of Abscisic Acid Signaling in the Induction of Antioxidant Defense in Leaves of Rice

    Institute of Scientific and Technical Information of China (English)

    Ben Shi; Lan Ni; Aying Zhang; Jianmei Cao; Hong Zhang; Tingting Qin; Mingpu Tan; Jianhua Zhang; Mingyi Jiang

    2012-01-01

    Ca2+ and calmodulin (CaM) have been shown to play an important role in abscisic acid (ABA)-induced antioxidant defense.However,it is unknown whether Ca2+/CaM-dependent protein kinase (CCaMK) is involved in the process.In the present study,the role of rice CCaMK,OsDMI3,in ABA-induced antioxidant defense was investigated in leaves of rice (Oryza sativa) plants.Treatments with ABA,H2O2,and polyethylene glycol (PEG) induced the expression of OsDMI3 and the activity of OsDMI3,and H2O2 is required for the ABA-induced increases in the expression and the activity of OsDMI3 under water stress.Subcellular localization analysis showed that OsDMI3 is located in the nucleus,the cytoplasm,and the plasma membrane.The analysis of the transient expression of OsDMI3 in rice protoplasts and the RNA interference (RNAi) silencing of OsDMI3 in rice protoplasts showed that OsDMI3 is required for ABA-induced increases in the expression and the activities of superoxide dismutase (SOD) and catalase (CAT).Further,the oxidative damage induced by higher concentrations of PEG and H2O2 was aggravated in the mutant of OsDMI3.Moreover,the analysis of the RNAi silencing of OsDMI3 in protoplasts and the mutant of OsDMI3 showed that higher levels of H2O2 accumulation require OsDMI3 activation in ABA signaling,but the initial H2O2 production induced by ABA is not dependent on the activation of OsDMI3 in leaves of rice plants.Our data reveal that OsDMI3 is an important component in ABA-induced antioxidant defense in rice.

  2. Evaluation of Salivary Level of Paraoxonase and Total Antioxidant Capacity in Type II Diabetic Subjects

    OpenAIRE

    Sh. Radi; H.R. Abdolsamadi; Ranjbar, A.; N. Rafieian; Sh. Borzoei; Gh. Roshanaei; M. Jazyeri; F. Montazeran

    2015-01-01

    Introduction & Objective: Salivary antioxidants play important roles in the defensive mechanism of saliva against free radicals. Due to Prevalence of diabetes and numerous factors associated in its pathogenesis, understanding the defensive mechanism of salivary antioxidant against free radicals can provide helpful strategies in diagnosis and evaluation of diabetes. The aim of this study was evaluation of the paraoxonase (PON1) levels and total antioxidant capacity (TAC) of saliva in diabetic ...

  3. Role of vitamin B6 status on antioxidant defenses, glutathione, and related enzyme activities in mice with homocysteine-induced oxidative stress

    OpenAIRE

    Huang, Yi-Chia; Hsu, Cheng-Chin; Cheng, Chien-Hsiang; Hsu, Chin-Lin; Lee, Wan-Ju; Huang, Shih-Chien

    2015-01-01

    Background: Vitamin B6 may directly or indirectly play a role in oxidative stress and the antioxidant defense system.Objective: The purpose of this study was to examine the associations of vitamin B6 status with cysteine, glutathione, and its related enzyme activities in mice with homocysteine-induced oxidative stress.Design: Four-week-old male BALB/c mice were weighed and divided into one of four dietary treatment groups fed either a normal diet (as a control group and a homocysteine group),...

  4. Enhancement the Thermal Stability and the Mechanical Properties of Acrylonitrile-Butadiene Copolymer by Grafting Antioxidant

    Directory of Open Access Journals (Sweden)

    Abdulaziz Ibrahim Al-Ghonamy

    2010-01-01

    Full Text Available Monomeric antioxidants are widely used as effective antioxidants to protect polymers against thermal oxidation. Low molecular weight antioxidants are easily lost from polymer through migration, evaporation, and extraction. Physical loss of antioxidants is considered to be major concern in the environmental issues and safety regulation as well as long life time of polymers. The grafting copolymerization of natural rubber and o-aminophenol was carried out by using two-roll mill machine. The prepared natural rubber-graft-o-Aminophenol, NR-graft-o-AP, was analysed by using Infrared and 1H-NMR Spectroscopy techniques. The thermal stability, mechanical properties, and ultrasonic attenuation coefficient were evaluated for NBR vulcanizates containing the commercial antioxidant, N-phenyl-β-naphthylamine (PBN, the prepared grafted antioxidant, NR-graft-o-AP, and the control vulcanizate. Results of the thermal stability showed that the prepared NR-graft-o-AP can protect NBR vulcanizate against thermal treatment much better than the commercial antioxidant, PBN, and control mix, respectively. The prepared grafted antioxidant improves the mechanical properties of NBR vulcanizate.

  5. Turning excitation into inhibition: Glu-GABA exchange as an endogenous defensive mechanism in epilepsy

    OpenAIRE

    Laszlo Heja; Miklos Palkovits

    2009-01-01

    The balance between excitation and inhibition is of crucial importance for the proper functioning of the nervous system. Many neurological disorders, like epilepsy or ischemia are characterized by a disruption of this balance, usually by the abnormal intensification of excitatory signals. Here we demonstrate that the intense excitation leads to the emergence of a previously unrecognized endogenous defense mechanism by which the extracellular excitatory glutamate (Glu) is exchanged for the inh...

  6. Investigating aggressive styles and defense mechanisms in bipolar patients and in their parents

    OpenAIRE

    Nicola Luigi Bragazzi; Franca Pezzoni; Giovanni Del Puente

    2014-01-01

    Bipolar disorder (BD) is a very common mental health disorder, whose etiology concerning aggressive styles and defense mechanisms is still poorly known despite the efforts dedicated to develop psychological and biological theories. After obtaining written signed informed consent, this study will recruit inpatients with a clinical diagnosis of BD, based on Structured Clinical Interview and the Diagnostic and Statistical Manual of Mental Disorders criteria, and their parents. The Bus-Perry Aggr...

  7. The Study of Irrational Beliefs, Defense Mechanisms and Marital Satisfaction in Fertile and Infertile women

    OpenAIRE

    Shahrzad Katiraei; Naeime Bazmi; Mahtab Haghighat; Fatemeh Ramezanzadeh; Hadi Bahrami

    2010-01-01

    Objective: This study aimed to compare irrational beliefs, defense mechanisms and marital satisfaction in fertile and infertile women. Materials and methods: This study was a causal comparative survey performed on 30 fertile and 30 infertile women chosen by available and simple random sampling out of the whole clients referred to Vali-e-Asr Reproductive Health Research Center from February 2009 to September 2009. The instruments of measurement included 3 questionnaires: Jones i...

  8. Defense Mechanisms in Alcohol Dependent Patients with Oral and Oropharinegal Cancer

    OpenAIRE

    Petrić, Daniela; Frančišković, Tanja; Juretić, Mirna; Šuković, Zoran; Graovac, Mirjana; Rački, Sanjin; Ružić, Tatjana; Britvić, Dolores

    2011-01-01

    The effects of psychological factors in alcoholics with malignant tumor of the oral cavity and oropharynx are scarcely explored. The aim of the research was to examine early family relations and investigate differences in the use of defense mechanisms in alcohol dependent patients suffering from malignant tumor of the oral cavity and oropharynx compared to alcohol dependent persons without malignant tumors and healthy controls. The research included 51 alcohol dependent patients t...

  9. Molecular mechanism of recombinant liver fatty acid binding protein's antioxidant activity

    OpenAIRE

    Yan, Jing; Gong, Yuewen; She, Yi-Min; Wang, Guqi; Roberts, Michael S; Burczynski, Frank J.

    2009-01-01

    Hepatocytes expressing liver fatty acid binding protein (L-FABP) are known to be more resistant to oxidative stress than those devoid of this protein. The mechanism for the observed antioxidant activity is not known. We examined the antioxidant mechanism of a recombinant rat L-FABP in the presence of a hydrophilic (AAPH) or lipophilic (AMVN) free radical generator. Recombinant L-FABP amino acid sequence and its amino acid oxidative products following oxidation were identified by MALDI quadrup...

  10. Korean red ginseng extract rejuvenates testicular ineffectiveness and sperm maturation process in aged rats by regulating redox proteins and oxidative defense mechanisms.

    Science.gov (United States)

    Kopalli, Spandana Rajendra; Hwang, Seock-Yeon; Won, Yu-Jin; Kim, Sung-Won; Cha, Kyu-Min; Han, Chang-Kyun; Hong, Jae-Yup; Kim, Si-Kwan

    2015-09-01

    Distortion of intracellular oxidant and antioxidant balances appears to be a common feature that underlies in age-related male sexual impairment. Therefore regulating oxidative defense mechanisms might be an ideal approach in improving male sexual dysfunctions. In the present study, the effect of Korean red ginseng aqueous extract (KRG) on age-induced testicular dysfunction in rats was investigated. KRG (200mg/kg) mixed with regular pellet diet was administered orally for six months and the morphological, spermatogenic and antioxidant enzyme status in testis of aged rats (18months) were evaluated. Data indicated a significant change in morphology and decrease in spermatogenesis-related parameters in aged rats (AC) compared with young rats (YC). Sperm number, germ cell count, Sertoli cell count and Sertoli cell index were significantly (p<0.05) restored in KRG-treated aged rat groups (G-AC). Further the increased lipid peroxidation as measured by malondialdehyde (p<0.05), and altered enzymatic (superoxide dismutase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and catalase) and non-enzymatic (reduced glutathione, ascorbic acid and α-tocopherol) antioxidants (p<0.05) were attenuated by KRG treatment in aged rats to near normal levels as in YC groups. Furthermore, proteomic analysis demonstrated differential expression of selected proteins such as phosphatidylinositol transfer protein, fatty acid binding protein-9, triosephosphate isomerase-1 and aldehyde (aldose) reductase-1in aged rats was significantly (p<0.05) protected by KRG treatment. In conclusion, long-term administration of KRG restored aging-induced testicular ineffectiveness in rats by modulating redox proteins and oxidative defense mechanisms. PMID:25980653

  11. Effects of anthracene on filtration rates, antioxidant defense system, and redox proteomics in the Mediterranean clam Ruditapes decussatus (Mollusca: Bivalvia).

    Science.gov (United States)

    Sellami, Badreddine; Khazri, Abdelhafidh; Louati, Héla; Dellali, Mohamed; Driss, Mouhamed Ridha; Aïssa, Patricia; Mahmoudi, Ezzeddine; Hamouda, Beyrem; Coelho, Ana Varela; Sheehan, David

    2015-07-01

    This study aimed at analyzing the impact of a toxic polyaromatic hydrocarbon (PAH), anthracene (ANT), on Ruditapes decussatus collected from a Tunisian coastal lagoon (Bizerte Lagoon). Filtration rates, several antioxidant enzymes--superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione transferase (GST)--as well as indices of protein oxidation status were determined in various tissues of this bivalve. Specimens were exposed to 100 μg/L of ANT for 2 days. ANT levels were evaluated using HPLC and were detected in the gill and digestive gland at different amounts. ANT exposure altered the behavior of bivalves by changing the siphon movement and decreasing filtration rate significantly. The enzymatic results indicated that ANT exposure affected the oxidative stress status of the gills of R. decussatus. In addition, modification of proteins was detected in the gills using redox proteomics after ANT treatment. Three protein spots were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF-MS). These proteins can be roughly related to muscle contraction function. In contrast, no significant modification of enzymatic and protein responses was detected in the digestive gland after ANT treatment. These data demonstrate that combined behavioral and biochemical analyses are a powerful tool to provide valuable insights into possible mechanisms of toxicity of anthracene in R. decussatus. Additionally, the results highlight the potential of the gill as a valuable candidate for investigating PAH toxicity. PMID:25779113

  12. Gestational diabetes mellitus impairs Nrf2-mediated adaptive antioxidant defenses and redox signaling in fetal endothelial cells in utero.

    Science.gov (United States)

    Cheng, Xinghua; Chapple, Sarah J; Patel, Bijal; Puszyk, William; Sugden, David; Yin, Xiaoke; Mayr, Manuel; Siow, Richard C M; Mann, Giovanni E

    2013-12-01

    In utero exposure to gestational diabetes mellitus (GDM) is associated with an increased risk of type 2 diabetes and cardiovascular disease in later life, yet the underlying mechanisms remain to be elucidated. We examined the effects of GDM on the proteome, redox status, and nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant gene expression in human fetal endothelial cells. Proteomic analysis revealed that proteins involved in redox homeostasis were significantly altered in GDM and associated with increased mitochondrial superoxide generation, protein oxidation, DNA damage, and diminished glutathione (GSH) synthesis. In GDM cells, the lipid peroxidation product 4-hydroxynonenal (HNE) failed to induce nuclear Nrf2 accumulation and mRNA and/or protein expression of Nrf2 and its target genes NAD(P)H:quinone oxidoreductase 1 (NQO1), Bach1, cystine/glutamate transporter, and glutamate cysteine ligase. Although methylation of CpG islands in Nrf2 or NQO1 promoters was unaltered by GDM, decreased DJ-1 and increased phosphorylated glycogen synthase kinase 3β levels may account for impaired Nrf2 signaling. HNE-induced increases in GSH and NQO1 levels were abrogated by Nrf2 small interfering RNA in normal cells, and overexpression of Nrf2 in GDM cells partially restored NQO1 induction. Dysregulation of Nrf2 in fetal endothelium may contribute to the increased risk of type 2 diabetes and cardiovascular disease in offspring. PMID:23974919

  13. White Racial Identity Attitudes and the Ego Defense Mechanisms Used by White Counselor Trainees in Racially Provocative Counseling Situations.

    Science.gov (United States)

    Utsey, Shawn O.; Gernat, Carol A.

    2002-01-01

    Examines the relationship between racial identity attitudes and the use of ego defense mechanisms by White counselor trainees during cross-racial counseling and supervision dyads. Results indicated that White counselor trainees at less mature statuses of racial identity attitudes relied on more primitive ego defenses to manage the anxiety…

  14. Activation of insect anti-oxidative mechanism by mammalian glucagon

    Czech Academy of Sciences Publication Activity Database

    Alquicer, Glenda; Kodrík, Dalibor; Krishnan, N.; Večeřa, Josef; Socha, Radomír

    2009-01-01

    Roč. 152, č. 3 (2009), s. 226-233. ISSN 1096-4959 R&D Projects: GA ČR GA522/07/0788 Institutional research plan: CEZ:AV0Z50070508 Keywords : adipokinetic hormone * antioxidant capacity * glucagon Subject RIV: ED - Physiology Impact factor: 1.607, year: 2009

  15. Investigating aggressive styles and defense mechanisms in bipolar patients and in their parents

    Directory of Open Access Journals (Sweden)

    Nicola Luigi Bragazzi

    2014-10-01

    Full Text Available Bipolar disorder (BD is a very common mental health disorder, whose etiology concerning aggressive styles and defense mechanisms is still poorly known despite the efforts dedicated to develop psychological and biological theories. After obtaining written signed informed consent, this study will recruit inpatients with a clinical diagnosis of BD, based on Structured Clinical Interview and the Diagnostic and Statistical Manual of Mental Disorders criteria, and their parents. The Bus-Perry Aggression Questionnaire, the Defense Style Questionnaire 40, the Symptom check list SCL-90-R, developed by DeRogatis will be administered to the participants, together with a semi-structured questionnaire concerning demographic data (age, gender, employment, education and only for the patients clinical information (onset year of the disorder, presence of co-morbidities, alcohol and drug use, suicide tendencies, kind of treatment. All the questionnaires are in the Italian validated version. The successful completion of this study will shed light on the relationship between aggressive styles and defensive mechanisms in bipolar inpatients and in their parents, helping the clinicians to develop ad hoc psychological interventions.

  16. Lipid Peroxidative Damage on Cisplatin Exposure and Alterations in Antioxidant Defense System in Rat Kidneys: A Possible Protective Effect of Selenium

    Directory of Open Access Journals (Sweden)

    Branka I. Ognjanović

    2012-02-01

    Full Text Available Cisplatin (Cis-diamminedichloroplatinum II, CP is an important chemotherapeutic agent, useful in the treatment of several cancers, but with several side effects such as nephrotoxicity. The present study investigated the possible protective effect of selenium (Se against CP-induced oxidative stress in the rat kidneys. Male Wistar albino rats were injected with a single dose of cisplatin (7 mg CP/kg b.m., i.p. and selenium (6 mg Se/kg b.m, as Na2SeO3, i.p., alone or in combination. The obtained results showed that CP increased lipid peroxidation (LPO and decreased reduced glutathione (GSH concentrations, suggesting the CP-induced oxidative stress, while Se treatment reversed this change to control values. Acute intoxication of rats with CP was followed by statistically significant decreased activity of antioxidant defense enzymes: superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GSH-Px, glutathione reductase (GR and glutathione-S-transferase (GST. Treatment with Se reversed CP-induced alterations of antioxidant defense enzyme activities and significantly prevented the CP-induced kidney damage.

  17. The Effect of a 12-Week Moderate Intensity Interval Training Program on the Antioxidant Defense Capability and Lipid Profile in Men Smoking Cigarettes or Hookah: A Cohort Study

    Directory of Open Access Journals (Sweden)

    Abdessalem Koubaa

    2015-01-01

    Full Text Available Aim. To examine the impact of interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah unable or unwilling to quit smoking. Methods. Thirty-five participants performed an interval training (2 : 1 work : rest ratio 3 times a week for 12 weeks at an intensity of 70% of VO2max. All subjects were subjected to a biochemical test session before and after the training program. Results. The increase of total antioxidant status (TAS, glutathione peroxidase (GPx, and α-tocopherol, is significant only for cigarette smokers (CS and hookah smokers (HS groups. The decrease of malondialdehyde (MDA and the increase of glutathione reductase (GR are more pronounced in smokers groups compared to those of nonsmokers (NS. Superoxide dismutase (SOD increases in NS, CS, and HS groups by 10.1%, 19.5%, and 13.3%, respectively (P<0.001. Likewise, a significant improvement of high-density lipoprotein cholesterol (HDL-C and TC/HDL-C ratio was observed in CS and HS groups (P<0.05. Conclusion. Although the interval training program does not have a significant effect on blood lipid levels, it seems to be very beneficial in the defense and prevention programs of oxidative stress.

  18. Waterborne gemfibrozil challenges the hepatic antioxidant defense system and down-regulates peroxisome proliferator-activated receptor beta (PPARβ) mRNA levels in male goldfish (Carassius auratus)

    International Nuclear Information System (INIS)

    The lipid regulator gemfibrozil (GEM) is one of many human pharmaceuticals found in the aquatic environment. We previously demonstrated that GEM bioconcentrates in blood and reduces plasma testosterone levels in goldfish (Carassius auratus). In this study, we address the potential of an environmentally relevant waterborne concentration of GEM (1.5 μg/l) to induce oxidative stress in goldfish liver and whether this may be linked to GEM acting as a peroxisome proliferator (PP). We also investigate the autoregulation of the peroxisome proliferator-activated receptors (PPARs) as a potential index of exposure. The three PPAR subtypes (α, β, and γ) were amplified from goldfish liver cDNA. Goldfish exposed to a concentration higher (1500 μg/l) than environmentally relevant for 14 and 28 days significantly reduce hepatic PPARβ mRNA levels (p < 0.001). Levels of CYP1A1 mRNA were unchanged. GEM exposure significantly induced the antioxidant defense enzymes catalase (p < 0.001), glutathione peroxidase (p < 0.001) and glutathione-S-transferase (p = 0.006) but not acyl-CoA oxidase or glutathione reductase. As GEM exposure failed to increase levels of thiobarbituric reactive substances (TBARS), we conclude that a sub-chronic exposure to GEM upregulates the antioxidant defense status of the goldfish as an adaptive response to this human pharmaceutical

  19. Molecular Dynamics Simulation and Statistics Analysis Reveals the Defense Response Mechanism in Plants

    Science.gov (United States)

    Liu, Zhichao; Zhao, Yunjie; Zeng, Chen; Computational Biophysics Lab Team

    As the main protein of the bacterial flagella, flagellin plays an important role in perception and defense response. The newly discovered locus, FLS2, is ubiquitously expressed. FLS2 encodes a putative receptor kinase and shares many homologies with some plant resistance genes and even with some components of immune system of mammals and insects. In Arabidopsis, FLS2 perception is achieved by the recognition of epitope flg22, which induces FLS2 heteromerization with BAK1 and finally the plant immunity. Here we use both analytical methods such as Direct Coupling Analysis (DCA) and Molecular Dynamics (MD) Simulations to get a better understanding of the defense mechanism of FLS2. This may facilitate a redesign of flg22 or de-novo design for desired specificity and potency to extend the immune properties of FLS2 to other important crops and vegetables.

  20. Role of antioxidant defense system and biochemical adaptation on stress tolerance of high mountain and steppe plants

    Science.gov (United States)

    Öncel, Işıl; Yurdakulol, Ender; Keleş, Yüksel; Kurt, Latif; Yıldız, Atilla

    2004-12-01

    Eleven species were collected from Northwest Anatolian mountains (1500-2000 m) and 18 species were collected from the Central Anatolian steppes (850-1000 m) in June 1998 and 1999. In all the species investigated, the water and dry matter percentages and solute contents were measured. The chlorophyll, β-carotene, ascorbate and α-tocopherol contents and catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR) enzyme activities of the plants were also determined. The steppe plants had lower water content compared with alpine plants. The chlorophyll contents of the plants investigated did not change with altitude. However, the carotenoid/chlorophyll ratio of alpine plants was found to be significantly higher. The antioxidant/chlorophyll ratio of the trees and shrubs was higher than that of herbaceous plants. Carotenoid concentrations and SOD activity were higher in alpine plants than in steppe plants. Proline and soluble protein concentrations were significantly higher in alpine plants than in steppe plants. There was a significant difference between the plants as regards to antioxidant capacity at the family level. Though there was a high antioxidant capacity in alpine Poaceae, Lamiaceae species from steppe had very low concentrations of antioxidants. In conclusion, it was shown that although antioxidant protection was important in alpine plants, there were significant differences among the plant species. In addition to antioxidant protection, the higher soluble protein and proline contents have a very important role in the stress resistance of the alpine plants.

  1. Effect of Vitamin E and Selenium Supplement on Paraoxonase-1 Activity, Oxidized Low Density Lipoprotein and Antioxidant Defense in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mohammad-Reza Rashidi

    2011-08-01

    Full Text Available Introduction: The aim of the present study was to assess the effects of vitamin E and selenium supplementation on serum paraoxonase (PON1 activity, lipid peroxidation and antioxidant defense in streptozotocin-induced diabetic rats. Methods: Thirty two female Sprague Dawley rats were divided into 3 groups: the control group (n=8 received a standard diet; streptozotocin (STZ-induced diabetic rats (n=12, received corn oil and physiological solution; and vitamin E and selenium supplemented diabetic rats (n=12 were treated with oral administration of vitamin E (300 mg/kg and sodium selenite (0.5 mg/kg once a day for 4 weeks. Results: Significantly lower total antioxidant status (TAS, PON1and erythrocyte SOD activities and a higher fasting plasma glucose level were observed in the diabetic rats compared to the control. A significant increase in SOD and GPX activities in vitamin E and selenium supplemented diabetic group was observed after 5 weeks of the experiment. Compared to the normal rats, malondialdehyde (MDA and oxidized LDL (Ox-LDL levels were higher in the diabetic animals; however, these values reduced significantly following vitamin E and selenium supplementation. Conclusion: Vitamin E and selenium supplementation in diabetic rats has hypolipidemic, hypoglycemic and antioxidative effects and may slow down the progression of diabetic complications through its protective effect on PON1 activity and lipoproteins oxidation.

  2. Noise-induced hearing loss (NIHL) as a target of oxidative stress-mediated damage: cochlear and cortical responses after an increase in antioxidant defense.

    Science.gov (United States)

    Fetoni, Anna Rita; De Bartolo, Paola; Eramo, Sara Letizia Maria; Rolesi, Rolando; Paciello, Fabiola; Bergamini, Christian; Fato, Romana; Paludetti, Gaetano; Petrosini, Laura; Troiani, Diana

    2013-02-27

    This study addresses the relationship between cochlear oxidative damage and auditory cortical injury in a rat model of repeated noise exposure. To test the effect of increased antioxidant defenses, a water-soluble coenzyme Q10 analog (Qter) was used. We analyzed auditory function, cochlear oxidative stress, morphological alterations in auditory cortices and cochlear structures, and levels of coenzymes Q9 and Q10 (CoQ9 and CoQ10, respectively) as indicators of endogenous antioxidant capability. We report three main results. First, hearing loss and damage in hair cells and spiral ganglion was determined by noise-induced oxidative stress. Second, the acoustic trauma altered dendritic morphology and decreased spine number of II-III and V-VI layer pyramidal neurons of auditory cortices. Third, the systemic administration of the water-soluble CoQ10 analog reduced oxidative-induced cochlear damage, hearing loss, and cortical dendritic injury. Furthermore, cochlear levels of CoQ9 and CoQ10 content increased. These findings indicate that antioxidant treatment restores auditory cortical neuronal morphology and hearing function by reducing the noise-induced redox imbalance in the cochlea and the deafferentation effects upstream the acoustic pathway. PMID:23447610

  3. Defense mechanisms of Solanum tuberosum L. in response to attack by plant-pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    VERA A D POIATTI

    2009-01-01

    Full Text Available The natural resistance of plants to disease is based not only on preformed mechanisms, but also on induced mechanisms. The defense mechanisms present in resistant plants may also be found in susceptible ones. This study attempted to analyze the metabolic alterations in plants of the potato Solanum tuberosum L. cv. Agata that were inoculated with the incompatible plant-pathogenic bacteria X. axonopodis and R. solanacearum, and the compatible bacterium E. carotovora. Levels of total phenolic compounds, including the flavonoid group, and the activities of polyphenol oxidase (PPO and peroxidase (POX were evaluated. Bacteria compatibility was evaluated by means of infiltration of tubers. The defense response was evaluated in the leaves of the potato plants. Leaves were inoculated depending on their number and location on the stem. Multiple-leaf inoculation was carried out on basal, intermediate, and apical leaves, and single inoculations on intermediate leaves. Leaves inoculated with X. axonopodis and with R. solanacearum showed hypersensitive responses within 24 hours post-inoculation, whereas leaves inoculated with E. carotovora showed disease symptoms. Therefore, the R. solanacearum isolate used in the experiments did not exhibit virulence to this potato cultivar. Regardless of the bacterial treatments, the basal leaves showed higher PPO and POX activities and lower levels of total phenolic compounds and flavonoids, compared to the apical leaves. However, basal and intermediate leaves inoculated with R. solanacearum and X. axonopodis showed increases in total phenolic compounds and flavonoid levels. In general, multiple-leaf inoculation showed the highest levels of total phenolics and flavonoids, whereas the single inoculations resulted in the highest increase in PPO activity. The POX activity showed no significant difference between single- and multiple-leaf inoculations. Plants inoculated with E. carotovora showed no significant increase in

  4. A Discrete Event Simulator for Extensive Defense Mechanism for Denial of Service Attacks Analysis

    Directory of Open Access Journals (Sweden)

    Maryam Tanha

    2012-01-01

    Full Text Available Problem statement: Seeking for defense mechanisms against low rate Denial of Service (DoS attacks as a new generation of DoS attacks has received special attention during recent years. As a decisive factor, evaluating the performance of the offered mitigation techniques based on different metrics for determining the viability and ability of these countermeasures requires more research. Approach: The development of a new generalized discrete event simulator has been deliberated in detail. The research conducted places high emphasis on the benefits of creating a customized discrete event simulator for the analysis of security and in particular the DoS attacks. The simulator possesses a niche in terms of the small scale, low execution time, portability and ease of use. The attributes and mechanism of the developed simulator is complemented with the proposed framework. Results: The simulator has been extensively evaluated and has proven to provide an ideal tool for the analysis and exploration of DoS attacks. In-depth analysis is enabled by this simulator for creating multitudes of defense mechanisms against HTTP low rate DoS attacks. The acquired results from the simulation tool have been compared against a simulator from the same domain. Subsequently, it enables the validation of developed simulator utilizing selected performance metrics including mean in-system time, average delay and average buffer size. Conclusion: The proposed simulator serves as an efficient and scalable performance analysis tool for the analysis of HTTP low rate DoS attack defense mechanism. Future work can encompass the development of discrete event simulators for analysis of other security issues such as Intrusion Detection Systems.

  5. Antioxidant mechanism of bilirubin: both HAT and SET are possible

    International Nuclear Information System (INIS)

    Bilirubin (BR) plays two extreme roles in physiology, one hand it is a toxic metabolite while at micromolar concentration it acts as antioxidant. It has been observed that hydroxyl, glutathiyl and Linoleic peroxyl radicals abstract hydrogen atom from bilirubin, whereas N3, Br2, CCl3OO, NO2 radicals react via single electron transfer action. Our study demonstrates that oxidation of bilirubin occurs via both hydrogen atom transfer and single electron transfer depending on the nature of the radical. (author)

  6. The analysis of the defense mechanism against indigenous bacterial translocation in X-irradiated mice

    International Nuclear Information System (INIS)

    The defense mechanism against indigenous bacterial translocation was studied using a model of endogenous infection in X-irradiated mice. All mice irradiated with 9 Gy died from day 8 to day 15 after irradiation. The death of mice was observed in parallel with the appearance of bacteria from day 7 in various organs, and the causative agent was identified to be Escherichia coli, an indigenous bacterium translocating from the intestine. Decrease in the number of blood leukocytes, peritoneal cells and lymphocytes in Peyer's patches or mesenteric lymph nodes was observed as early as 1 day after irradiation with 6 or 9 Gy. The mitogenic response of lymphocytes from various lymphoid tissues was severely affected as well. The impairment of these parameters for host defense reached the peak 3 days after irradiation and there was no recovery. However, in vivo bacterial activity of Kupffer cells in mice irradiated with 9 Gy was maintained in a normal level for a longer period. It was suggested that Kupffer cells play an important role in the defense against indigenous bacteria translocating from the intenstine in mice. (author)

  7. Modulation of pulmonary defense mechanisms by acute exposures to nitrogen dioxide

    International Nuclear Information System (INIS)

    The effect of acute exposures to NO2 on the antibacterial defenses of the murine lung was assessed following inhalation challenges with Staphylococcus aureus, Proteus mirabilis, and Pasteurella pneumotropica. With S. aureus pulmonary antibacterial defenses were suppressed at NO2 levels of 4.0 ppm and greater. Exposure to 10.0 ppm enhanced the intrapulmonary killing of P. mirabilis which correlated with an increase in the phagocytic cell populations lavaged from the lungs; at 20.0 ppm bactericidal activity against P. mirabilis was impaired. Pulmonary antibacterial defenses against P. pneumotropica were impaired at 10.0 ppm which correlated with a decrease in the retrieved phagocytic lung cell population. Reversing the order of treatment (ie., NO2 exposure prior to bacterial challenge) raised the threshold concentration for NO2-induced impairment of intrapulmonary bacterial killing. With S. aureus the effect was not observed at 5.0 ppm but at 10.0 ppm and with P. mirabilis not at 20.0 ppm but at 30.0 ppm intrapulmonary killing was enhanced. Exposures up to 20.0 ppm of NO2 did not effect the physical translocation mechanisms of the lung as quantitated by declines in pulmonary radiotracer activity following aerogenic challenge with 32P-labeled staphylococci

  8. A Psychoanalytical Reading of Emily Brontë's Wuthering Heights : An Analysis of the Defense Mechanisms of Some Characters

    OpenAIRE

    Abdul Kareem, Ala'a

    2011-01-01

    This essay presents a portrayal of Heathcliff, Catherine and Isabella from a psychoanalytical perspective with regard to four defense mechanisms; namely, repression, denial, sublimation and projection in order to see how these defense mechanisms have affected the characters’ decisions and behaviour, and led them to their destinations in life. It will include three major sections: repression in characters, denial in characters, and sublimation and projection in characters. These terms will be ...

  9. Troubles with self-consciousness. Jervis on introspection and defense mechanisms.

    Science.gov (United States)

    Marraffa, Massimo

    2012-01-01

    Building on Sigmund Freud, Ernesto de Martino and cognitive sciences, Giovanni Jervis has outlined a view of introspective consciousness as primarily an activity of narrative re-appropriation of the outputs of the unconscious cognitive processing, emphasizing that such an activity is ruled by the primary need to construct an identity that is valid as much as possible. Thus Jervis has originally pursued an integration between the anti-introspectionist tradition in cognitive sciences and the psychodynamic investigation on defense mechanisms. This paper outlines Jervis' attempt to integrate these two traditions, and shows that it fits very well with recent developments of the theory-theory approach to self-knowledge. PMID:25807693

  10. Effect of dietary n-3 polyunsaturated fatty acids on antioxidant defense and sperm quality in rainbow trout (Oncorhynchus mykiss) under regular stripping conditions.

    Science.gov (United States)

    Köprücü, Kenan; Yonar, Muhammet Enis; Özcan, Sinan

    2015-12-01

    This study examined the effect of dietary n-3 polyunsaturated fatty acids (PUFA) on malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and reduced glutathione (GSH) levels; semen and liver fatty acid compositions; and spermatological values (semen volume and pH, sperm density, percentage and duration of sperm motility) in rainbow trout (Oncorhynchus mykiss) under regular stripping conditions. For this purpose, one control and two experimental diets were prepared as isonitrogenous and isocaloric. The control diet did not contain n-3 PUFA. However, the D1 and D2 diets were supplemented with n-3 PUFA concentrated anchovy oil at a 1% and 2% level, respectively. The n-3 PUFA content in the semen and liver, semen volume, initial sperm motility, duration of 50% sperm motility, total duration of sperm motility and sperm density values of the control fish fed the n-3 PUFA-deficient diet were decreased and were accompanied by a reduction of the antioxidant defense (SOD, CAT, GSH-Px and GSH) and an elevation of MDA in the blood, gonad, liver and kidney at all of the sampling periods (P0.01). However, supplementation with n-3 PUFA protected the fish from these adverse effects. The modulations were clearly observed in the fish fed the D2 diet because they were under lower oxidative stress, as indicated by MDA. The increased enzyme activity corresponds with the physiological mechanisms combating the elevation of free radicals under oxidative stress. The highest n-3 PUFA levels in the semen and liver and spermatological values were obtained from the fish fed the D2 diet at all of the sampling periods. On the other hand, the effects of the sampling stage on the spermatological values of the fish fed the D1 and D2 diets were not significant (P>0.01). However, the effects of the sampling stage in the fish fed the control diet on these values (with the exception of semen pH) were significant (Preproduction. PMID:26530952

  11. Food-grade argan oil supplementation in molasses enhances fermentative performance and antioxidant defenses of active dry wine yeast.

    Science.gov (United States)

    Gamero-Sandemetrio, Esther; Torrellas, Max; Rábena, María Teresa; Gómez-Pastor, Rocío; Aranda, Agustín; Matallana, Emilia

    2015-12-01

    The tolerance of the yeast Saccharomyces cerevisiae to desiccation is important for the use of this microorganism in the wine industry, since active dry yeast (ADY) is routinely used as starter for must fermentations. Both biomass propagation and dehydration cause cellular oxidative stress, therefore negatively affecting yeast performance. Protective treatments against oxidative damage, such as natural antioxidants, may have important biotechnological implications. In this study we analysed the antioxidant capacity of pure chemical compounds (quercetin, ascorbic acid, caffeic acid, oleic acid, and glutathione) added to molasses during biomass propagation, and we determine several oxidative damage/response parameters (lipid peroxidation, protein carbonylation, protective metabolites and enzymatic activities) to assess their molecular effects. Supplementation with ascorbic, caffeic or oleic acids diminished the oxidative damage associated to ADY production. Based on these results, we tested supplementation of molasses with argan oil, a natural food-grade ingredient rich in these three antioxidants, and we showed that it improved both biomass yield and fermentative performance of ADY. Therefore, we propose the use of natural, food-grade antioxidant ingredients, such as argan oil, in industrial processes involving high cellular oxidative stress, such as the biotechnological production of the dry starter. PMID:26621111

  12. Melatonin, a potent agent in antioxidative defense: Actions as a natural food constituent, gastrointestinal factor, drug and prodrug

    Directory of Open Access Journals (Sweden)

    Pandi-Perumal SR

    2005-09-01

    Full Text Available Abstract Melatonin, originally discovered as a hormone of the pineal gland, is also produced in other organs and represents, additionally, a normal food constituent found in yeast and plant material, which can influence the level in the circulation. Compared to the pineal, the gastrointestinal tract contains several hundred times more melatonin, which can be released into the blood in response to food intake and stimuli by nutrients, especially tryptophan. Apart from its use as a commercial food additive, supraphysiological doses have been applied in medical trials and pure preparations are well tolerated by patients. Owing to its amphiphilicity, melatonin can enter any body fluid, cell or cell compartment. Its properties as an antioxidant agent are based on several, highly diverse effects. Apart from direct radical scavenging, it plays a role in upregulation of antioxidant and downregulation of prooxidant enzymes, and damage by free radicals can be reduced by its antiexcitatory actions, and presumably by contributions to appropriate internal circadian phasing, and by its improvement of mitochondrial metabolism, in terms of avoiding electron leakage and enhancing complex I and complex IV activities. Melatonin was shown to potentiate effects of other antioxidants, such as ascorbate and Trolox. Under physiological conditions, direct radical scavenging may only contribute to a minor extent to overall radical detoxification, although melatonin can eliminate several of them in scavenger cascades and potentiates the efficacy of antioxidant vitamins. Melatonin oxidation seems rather important for the production of other biologically active metabolites such as N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK and N1-acetyl-5-methoxykynuramine (AMK, which have been shown to also dispose of protective properties. Thus, melatonin may be regarded as a prodrug, too. AMK interacts with reactive oxygen and nitrogen species, conveys protection to mitochondria

  13. Role of Trichoderma harzianum in mitigating NaCl stress in Indian mustard (Brassica juncea L) through antioxidative defense system

    OpenAIRE

    Ahmad, Parvaiz; Hashem, Abeer; Abd-Allah, Elsayed Fathi; Alqarawi, A. A.; John, Riffat; Egamberdieva, Dilfuza; Gucel, Salih

    2015-01-01

    Salinity stress affected crop production of more than 20% of irrigated land globally. In the present study the effect of different concentrations of NaCl (0, 100, and 200 mM) on growth, physio-biochemical attributes, antioxidant enzymes, oil content, etc. in Brassica juncea and the protective role of Trichoderma harzianum (TH) was investigated. Salinity stress deteriorates growth, physio-biochemical attributes, that ultimately leads to decreased biomass yield in mustard seedlings. Higher conc...

  14. Cytokinin oxidase/dehydrogenase overexpression modifies antioxidant defense against heat, drought and their combination in Nicotiana tabacum plants

    Czech Academy of Sciences Publication Activity Database

    Lubovská, Zuzana; Dobrá, Jana; Štorchová, Helena; Wilhelmová, Naděžda; Vaňková, Radomíra

    2014-01-01

    Roč. 171, č. 17 (2014), s. 1625-1633. ISSN 0176-1617 R&D Projects: GA ČR GA206/09/2062; GA MŠk LD14120 Institutional support: RVO:61389030 Keywords : Antioxidant enzymes * Cytokinin * Drought Subject RIV: ED - Physiology Impact factor: 2.557, year: 2014 http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Alerting&SrcApp=Alerting&DestApp=MEDLINE&DestLinkType=FullRecord&UT=25171514

  15. Food-grade argan oil supplementation in molasses enhances fermentative performance and antioxidant defenses of active dry wine yeast

    OpenAIRE

    Gamero-Sandemetrio, Esther; Torrellas, Max; Rábena, María Teresa; Gómez-Pastor, Rocío; Aranda, Agustín; Matallana, Emilia

    2015-01-01

    The tolerance of the yeast Saccharomyces cerevisiae to desiccation is important for the use of this microorganism in the wine industry, since active dry yeast (ADY) is routinely used as starter for must fermentations. Both biomass propagation and dehydration cause cellular oxidative stress, therefore negatively affecting yeast performance. Protective treatments against oxidative damage, such as natural antioxidants, may have important biotechnological implications. In this study we analysed t...

  16. Increased Tolerance of Citrus (Citrus tangerina Seedlings to Soil Water Deficit after Mycorrhizal Inoculation: Changes in Antioxidant Enzyme Defense System

    Directory of Open Access Journals (Sweden)

    Qiu-Dan NI

    2013-12-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF can enhance tolerance of plants to soil water deficit, whereas morphological observations of reactive oxygen species and antioxidant enzyme system are poorly studied. The present study thereby evaluated temporal variations of the antioxidant enzyme system in citrus (Citrus tangerina seedlings colonized by Glomus etunicatum and G. mosseae over a 12-day period of soil drying. Root colonization by G. etunicatum and G. mosseae decreased with soil drying days from 32.0 to 1.0% and 50.1 to 4.5% in 0-day to 12-day, respectively. Compared to the non-AM controls, the AMF colonized plants had significantly lower tissue (both leaves and roots hydrogen peroxide (H2O2 and superoxide anion radical (O2•– concentrations during soil water deficit, whereas 1.03–1.92, 1.25–1.84 and 1.18–1.69 times higher enzyme activity in superoxide dismutase, peroxidase (POD and catalase. In situ leaf H2O2 and root POD location also showed that AM seedlings had less leaf H2O2 but higher root POD accumulation. Furthermore, significantly higher root infection and antioxidant enzymatic activities in plants colonized with G. mosseae expressed than with G. etunicatum during the soil drying. These results demonstrated that the AMs could confer greater tolerance of citrus seedlings to soil water deficit through an enhancement in their antioxidant enzyme defence system whilst an decrease level in H2O2 and O2•–.

  17. Polyamines Confer Salt Tolerance in Mung Bean (Vigna radiata L.) by Reducing Sodium Uptake, Improving Nutrient Homeostasis, Antioxidant Defense, and Methylglyoxal Detoxification Systems

    Science.gov (United States)

    Nahar, Kamrun; Hasanuzzaman, Mirza; Rahman, Anisur; Alam, Md. Mahabub; Mahmud, Jubayer-Al; Suzuki, Toshisada; Fujita, Masayuki

    2016-01-01

    The physiological roles of PAs (putrescine, spermidine, and spermine) were investigated for their ability to confer salt tolerance (200 mM NaCl, 48 h) in mung bean seedlings (Vigna radiata L. cv. BARI Mung-2). Salt stress resulted in Na toxicity, decreased K, Ca, Mg, and Zn contents in roots and shoots, and disrupted antioxidant defense system which caused oxidative damage as indicated by increased lipid peroxidation, H2O2 content, O2•- generation rate, and lipoxygenase activity. Salinity-induced methylglyoxal (MG) toxicity was also clearly evident. Salinity decreased leaf chlorophyll (chl) and relative water content (RWC). Supplementation of salt affected seedlings with exogenous PAs enhanced the contents of glutathione and ascorbate, increased activities of antioxidant enzymes (dehydroascorbate reductase, glutathione reductase, catalase, and glutathione peroxidase) and glyoxalase enzyme (glyoxalase II), which reduced salt-induced oxidative stress and MG toxicity, respectively. Exogenous PAs reduced cellular Na content and maintained nutrient homeostasis and modulated endogenous PAs levels in salt affected mung bean seedlings. The overall salt tolerance was reflected through improved tissue water and chl content, and better seedling growth. PMID:27516763

  18. Comparison of gamma- and beta radiation stress responses on anti-oxidative defense system and DNA modifications in Lemna minor

    International Nuclear Information System (INIS)

    in a dosimetric model derived from ERICA tool. This enabled a reliable comparison of dose-dependent endpoints between gamma- and beta radiation. Dose rates varied from 15 and 1500 mGy/hr, and 19 from 19000 μGy/hr for gamma- and beta radiation respectively. The classic growth related endpoints, like biomass and frond area, were measured and compared with biochemical and molecular endpoints. Therefore, DNA modifications were analyzed to evaluate biological DNA damage and ROS accumulation in plants together with activities of anti-oxidative enzymes to evaluate oxidative stress response. A dose-response curve with 60 percent growth inhibition was determined for gamma radiation and morphological growth effects in root system were observed for beta radiation. Preliminary results showed similar responses in peroxidase activities between both radiation types. These results and ongoing investigations will help to unravel the differences and similarities in response mechanisms for various radiation types in plant systems. As multiple levels in biological organisation of the organism were considered, and also different dose rates taken into account, this approach allows a better understanding the toxic mode of action of radiation stress in higher plants. This research was supported by the European Commission Contract Fission-2010-3.5.1-269672 to Strategy for Allied Radioecology (www.star-radioecology.org) and a project of the Fund for Scientific Research (FWO-Vlaanderen, G.A040.11N) (authors)

  19. Comparison of gamma- and beta radiation stress responses on anti-oxidative defense system and DNA modifications in Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Van Hoeck, Arne [SCK.CEN, Boeretang 200 2400 Mol (Belgium); University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Horemans, Nele; Van Hees, May; Nauts, Robin; Vandenhove, Hildegarde [SCK.CEN, Boeretang 200 2400 Mol (Belgium); Knapen, Dries; Blust, Ronny [University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium)

    2014-07-01

    frond have been implemented in a dosimetric model derived from ERICA tool. This enabled a reliable comparison of dose-dependent endpoints between gamma- and beta radiation. Dose rates varied from 15 and 1500 mGy/hr, and 19 from 19000 μGy/hr for gamma- and beta radiation respectively. The classic growth related endpoints, like biomass and frond area, were measured and compared with biochemical and molecular endpoints. Therefore, DNA modifications were analyzed to evaluate biological DNA damage and ROS accumulation in plants together with activities of anti-oxidative enzymes to evaluate oxidative stress response. A dose-response curve with 60 percent growth inhibition was determined for gamma radiation and morphological growth effects in root system were observed for beta radiation. Preliminary results showed similar responses in peroxidase activities between both radiation types. These results and ongoing investigations will help to unravel the differences and similarities in response mechanisms for various radiation types in plant systems. As multiple levels in biological organisation of the organism were considered, and also different dose rates taken into account, this approach allows a better understanding the toxic mode of action of radiation stress in higher plants. This research was supported by the European Commission Contract Fission-2010-3.5.1-269672 to Strategy for Allied Radioecology (www.star-radioecology.org) and a project of the Fund for Scientific Research (FWO-Vlaanderen, G.A040.11N) (authors)

  20. Mechanisms of the antioxidant activity of a high molecular weight fraction of whey.

    Science.gov (United States)

    Tong, L M; Sasaki, S; McClements, D J; Decker, E A

    2000-05-01

    The antioxidant mechanisms of whey proteins in a Tween 20-stabilized salmon oil-in-water emulsion were investigated. The antioxidant activity of the high molecular weight (HMW) fraction of whey from pasteurized milk was found to increase with concentration, as determined by its ability to inhibit TBARS and lipid peroxide formation. The ability of sulfhydryl-blocked whey to inhibit TBARS formation was reduced 60% compared to the HMW fraction alone at 7 days of storage. HMW fraction was able to scavenge peroxyl radicals, with scavenging decreasing approximately 20% when sulfhydryls were blocked. HMW fraction was able to chelate iron away from the surface of negatively charged BSA-stabilized emulsion droplets, indicating that the whey proteins were able to chelate iron. A better understanding of the mechanisms by which whey proteins inhibit lipid oxidation could increase the use of whey proteins as food antioxidants. PMID:10820045

  1. Effects of mechanical damage and herbivore wounding on H2O2 metabolism and antioxidant enzyme activities in hybrid poplar leaves

    Institute of Scientific and Technical Information of China (English)

    AN Yu; SHEN Ying-bai; ZHANG Zhi-xiang

    2009-01-01

    The changes of hydrogen peroxide (H2O2) metabolism and antioxidant enzyme activities in a hybrid poplar (Populus simonii ×P. pyramidalis ‘Opera 8277') in response to mechanical damage (MD) and herbivore wounding (HW) were investigated to determine whether H2O2 could function as the secondary messenger in the signaling of systemic resistance. Results show that H2O2 was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves. The activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were also enhanced. However, the H2O2 accumulation and antioxidant enzyme activities were inhibited in MD leaves through the pretreatment with DPI (which is a specific inhibitor of NADPH oxidase). The results of this study suggest that H2O2 could be systemically induced by MD and HW treatments, and H2O2 metabolism was closely related to the change in SOD, APX and CAT activities. A high level of antioxidant enzymes could decrease membrane lipid peroxidation levels and effectively induce plant defense responses.

  2. Preventive effects of Salvia officinalis L. against learning and memory deficit induced by diabetes in rats: Possible hypoglycaemic and antioxidant mechanisms.

    Science.gov (United States)

    Hasanein, Parisa; Felehgari, Zhila; Emamjomeh, Abbasali

    2016-05-27

    Learning and memory impairment occurs in diabetes. Salvia officinalis L. (SO) has been used in Iranian traditional medicine as a remedy against diabetes. We hypothesized that chronic administration of SO (400, 600 and 800mg/kg, p.o.) and its principal constituent, rosmarinic acid, would affect on passive avoidance learning (PAL) and memory in streptozocin-induced diabetic and non-diabetic rats. We also explored hypoglycemic and antioxidant activities of SO as the possible mechanisms. Treatments were begun at the onset of hyperglycemia. PAL was assessed 30days later. Retention test was done 24h after training. At the end, animals were weighed and blood samples were drawn for further analyzing of glucose and oxidant/antioxidant markers. Diabetes induced deficits in acquisition and retrieval processes. SO (600 and 800mg/kg) and rosmarinic acid reversed learning and memory deficits induced by diabetes and improved cognition of healthy rats. While the dose of 400mg/kg had no effect, the higher doses and rosmarinic acid inhibited hyperglycemia and lipid peroxidation as well as enhanced the activity of antioxidant enzymes superoxide dismutase and catalase. SO prevented diabetes-induced acquisition and memory deficits through inhibiting hyperglycemia, lipid peroxidation as well as enhancing antioxidant defense systems. Therefore, SO and its principal constituent rosmarinic acid represent a potential therapeutic option against diabetic memory impairment which deserves consideration and further examination. PMID:27113201

  3. Monuments of memory: defensive mechanisms of the collective psyche and their manifestation in the memorialization process.

    Science.gov (United States)

    Kalinowska, Malgorzata

    2012-09-01

    The paper searches for insight in the area of collective memory as a part of collective consciousness, a phenomenon understood as a stabilizing factor for a society's self-image and identity. Collective memories are seen as originating from shared communications transmitting and creating the meaning of the past in the form of narrative, symbols and signs. As such, they contain the individual, embodied and lived side of our relations to the past. As well as the identity-building and meaning-making functions of collective memories, their defensive function is discussed with a focus on commemorative practices taking place in a transitional space between psychic and social life. Fears of a lack of collective identity and coherence have contributed to the way Polish commemorative practices have been shaped. This is considered in relation to the Smolensk catastrophe in 2010, viewed in the context of the Jungian concept of the collective psyche and the psychoanalytical understanding of defensive group mechanisms against trauma, especially those relating to loss and mourning. It leads to a consideration of how historical experiences and the experience of history can be accessed, as well as their meaning for individual and group development. PMID:22954041

  4. Effective but costly, evolved mechanisms of defense against a virulent opportunistic pathogen in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Yixin H Ye

    2009-04-01

    Full Text Available Drosophila harbor substantial genetic variation for antibacterial defense, and investment in immunity is thought to involve a costly trade-off with life history traits, including development, life span, and reproduction. To understand the way in which insects invest in fighting bacterial infection, we selected for survival following systemic infection with the opportunistic pathogen Pseudomonas aeruginosa in wild-caught Drosophila melanogaster over 10 generations. We then examined genome-wide changes in expression in the selected flies relative to unselected controls, both of which had been infected with the pathogen. This powerful combination of techniques allowed us to specifically identify the genetic basis of the evolved immune response. In response to selection, population-level survivorship to infection increased from 15% to 70%. The evolved capacity for defense was costly, however, as evidenced by reduced longevity and larval viability and a rapid loss of the trait once selection pressure was removed. Counter to expectation, we observed more rapid developmental rates in the selected flies. Selection-associated changes in expression of genes with dual involvement in developmental and immune pathways suggest pleiotropy as a possible mechanism for the positive correlation. We also found that both the Toll and the Imd pathways work synergistically to limit infectivity and that cellular immunity plays a more critical role in overcoming P. aeruginosa infection than previously reported. This work reveals novel pathways by which Drosophila can survive infection with a virulent pathogen that may be rare in wild populations, however, due to their cost.

  5. Using the Defensive Style Questionnaire to evaluate the impact of sex reassignment surgery on defensive mechanisms in transsexual patients Aplicação do Defensive Style Questionnaire para avaliar o impacto da cirurgia de redesignação sexual nos mecanismos de defesa de pacientes transexuais

    OpenAIRE

    Maria Inês Lobato; Walter José Koff; Tiago Crestana; Camila Chaves; Jaqueline Salvador; Analídia Rodolpho Petry; Esalba Silveira; Alexandre Annes Henriques; Fábio Cervo; Eduardo Siam Böhme; Raffael Massuda

    2009-01-01

    Objective: To evaluate the impact of sex reassignment surgery on the defense mechanisms of 32 transsexual patients at two different points in time using the Defensive Style Questionnaire. Method: The Defensive Style Questionnaire was applied to 32 patients upon their admission to the Gender Identity Disorder Program, and 12 months after they had undergone sex reassignment surgery. Results: There were changes in two defense mechanisms: anticipation and idealization. However, no significant dif...

  6. Curcuma purpurascens BI. rhizome accelerates rat excisional wound healing: involvement of Hsp70/Bax proteins, antioxidant defense, and angiogenesis activity

    Directory of Open Access Journals (Sweden)

    Rouhollahi E

    2015-10-01

    Full Text Available Elham Rouhollahi,1 Soheil Zorofchian Moghadamtousi,2 Fatemeh Hajiaghaalipour,3 Maryam Zahedifard,2 Faezeh Tayeby,2 Khalijah Awang,4 Mahmood Ameen Abdulla,3 Zahurin Mohamed1 1Pharmacogenomics Laboratory, Department of Pharmacology, Faculty of Medicine, 2Institute of Biological Sciences, Faculty of Science, 3Department of Biomedical Science, Faculty of Medicine, 4Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia Purpose: Curcuma purpurascens BI. is a member of Zingiberaceae family. The purpose of this study is to investigate the wound healing properties of hexane extract of C. purpurascens rhizome (HECP against excisional wound healing in rats.Materials and methods: Twenty four rats were randomly divided into 4 groups: A negative control (blank placebo, acacia gum, B low dose of HECP, C high dose of HECP, and D positive control, with 6 rats in each group. Full-thickness incisions (approximately 2.00 cm were made on the neck area of each rat. Groups 1–4 were treated two-times a day for 20 days with blank placebo, HECP (100 mg/kg, HECP (200 mg/kg, and intrasite gel as a positive control, respectively. After 20 days, hematoxylin and eosin and Masson’s trichrome stainings were employed to investigate the histopathological alterations. Protein expressions of Bax and Hsp70 were examined in the wound tissues using immunohistochemistry analysis. In addition, levels of enzymatic antioxidants and malondialdehyde representing lipid peroxidation were measured in wound tissue homogenates.Results: Macroscopic evaluation of wounds showed conspicuous elevation in wound contraction after topical administration of HECP at both doses. Moreover, histopathological analysis revealed noteworthy reduction in the scar width correlated with the enhanced collagen content and fibroblast cells, accompanied by a reduction of inflammatory cells in the granulation tissues. At the molecular level, HECP facilitates wound-healing process

  7. Analysis and utilization of plant antioxidative mechanism by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Haeng Soon; Kwak, Sang Soo; Kwon, Hye Gyung [Korea Research Institute of Bioscience and Biotechnology, Taejon (Korea)

    1999-03-01

    The gamma radiation-induced changes of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in callus cultures of cassava (Manihot esculenta) and sweet potato (Ipomoea batatas) were investigated. Both cell lines irradiated with 50 and 70 Gy on 7 days after subculture inhibited significantly the cell growth by 50% and 80% at 14 days after treatment (DAT), respectively. In 70 Gy irradiated with cassava calli SOD and POD specific activities increased by 4 and 2.5 folds at 14 DAT, respectively, whereas CAT activity was not affected. When sweet potato calli were irradiated 10 Gy POD activity showed the highest at 14 DAT, whereas the CAT activity was not affected. In the transgenic tobacco plants that overexpress swpal encoding anionic POD cDNA or swpnl encoding neutral POD cDNA, POD and SOD activities were not significantly increased after {gamma}-radiation treatment, but swpal-plants showed a higher activity than that of swpnl-or non-transgenic plants. Plant growth was severely inhibited showing a well correlation with the dose of radiation. Specially, {gamma}-radiation affected growth of shoot apical meristem. (author). 32 refs., 7 figs.

  8. Stress defense mechanisms of NADPH-dependent thioredoxin reductases (NTRs) in plants.

    Science.gov (United States)

    Cha, Joon-Yung; Barman, Dhirendra Nath; Kim, Min Gab; Kim, Woe-Yeon

    2015-01-01

    Plants establish highly and systemically organized stress defense mechanisms against unfavorable living conditions. To interpret these environmental stimuli, plants possess communication tools, referred as secondary messengers, such as Ca(2+) signature and reactive oxygen species (ROS) wave. Maintenance of ROS is an important event for whole lifespan of plants, however, in special cases, toxic ROS molecules are largely accumulated under excess stresses and diverse enzymes played as ROS scavengers. Arabidopsis and rice contain 3 NADPH-dependent thioredoxin reductases (NTRs) which transfer reducing power to Thioredoxin/Peroxiredoxin (Trx/Prx) system for scavenging ROS. However, due to functional redundancy between cytosolic and mitochondrial NTRs (NTRA and NTRB, respectively), their functional involvements under stress conditions have not been well characterized. Recently, we reported that cytosolic NTRA confers the stress tolerance against oxidative and drought stresses via regulation of ROS amounts using NTRA-overexpressing plants. With these findings, mitochondrial NTRB needs to be further elucidated. PMID:26039478

  9. Dietary açai modulates ROS production by neutrophils and gene expression of liver antioxidant enzymes in rats

    OpenAIRE

    Guerra, Joyce Ferreira da Costa; Magalhães, Cíntia Lopes de Brito; Costa, Daniela Caldeira; Silva, Marcelo Eustáquio; Pedrosa, Maria Lúcia

    2011-01-01

    Açai (Euterpe oleracea Mart.) has recently emerged as a promising source of natural antioxidants. Because increased oxidative stress and impaired antioxidant defense mechanisms are important factors in the development of diabetic complications and many health claims have been reported for açai, the present study was undertaken to evaluate the possible protective effects of açai on the production of reactive oxygen species by neutrophils and on the liver antioxidant defense system in control a...

  10. Responses of antioxidant defense system to polyfluorinated dibenzo-p-dioxins (PFDDs) exposure in liver of freshwater fish Carassius auratus.

    Science.gov (United States)

    Li, Chenguang; Qin, Li; Qu, Ruijuan; Sun, Ping; Wang, Zunyao

    2016-04-01

    In this study, we evaluated the toxicity of ten polyfluorinated dibenzo-p-dioxins (PFDDs) congeners to freshwater fish Carassius auratus, by determining the antioxidative responses and lipid peroxidation in the liver after the fish were injected with two different concentrations (10 and 100 µmol/kg) of individual PFDDs for 3 and 14 days. The results showed that oxidative stress was obviously induced in some PFDDs-treated groups, as implied by the significantly inhibited antioxidants levels (superoxide dismutase, catalase, reduced glutathione, and glutathione S-transferase) and elevated malondialdehyde content. In addition, the oxidative stress inducing ability was variable for different PFDDs congeners, which was related with the substitution number and position of fluorine atom. Based on the calculated integrated biomarker response (IBR) values, the toxicity was ranked as 2,3,7,8-FDD>Octa-FDD>1,2,3,4,7-FDD>1,3,6,8-FDD>1,2,3,4,6,7-FDD>1,2,6,7-FDD>1,2,7-FDD>DD>2,7-FDD>2-FDD. This study can enhance the general understanding of the PFDDs induced oxidative stress in aquatic organisms. PMID:26761781

  11. Defense mechanisms in congenital and acquired facial disfigurement: a clinical-empirical study.

    Science.gov (United States)

    van den Elzen, Marijke E P; Versnel, Sarah L; Perry, J Christopher; Mathijssen, Irene M J; Duivenvoorden, Hugo J

    2012-04-01

    It is of clinical interest to investigate the degree to which patients with facial disfigurement use defense styles. Therefore, 59 adults born with rare facial clefts, 59 patients with facial deformities acquired at an adult age, and a reference group of 141 adults without facial disfigurements completed standardized questionnaires. There was a significant difference between the group with and the group without disfigurements on immature defense styles, with the disfigured group using the immature style more frequently. There was a trend for the nondisfigured group to use more mature defense styles. No difference between congenital and acquired groups was seen on individual types of defense style. Self-esteem had the strength to differentiate mature and immature defense styles within our disfigured groups. The association of low self-esteem and the utilization of immature defense styles suggests that professional help may tailor treatment on discussing immature defense style and problems triggering or maintaining this style. PMID:22456586

  12. In vivo NMR metabolic profiling of Fabrea salina reveals sequential defense mechanisms against ultraviolet radiation.

    Science.gov (United States)

    Marangoni, Roberto; Paris, Debora; Melck, Dominique; Fulgentini, Lorenzo; Colombetti, Giuliano; Motta, Andrea

    2011-01-01

    Fabrea salina is a hypersaline ciliate that is known to be among the strongest ultraviolet (UV)-resistant microorganisms; however, the molecular mechanisms of this resistance are almost unknown. By means of in vivo NMR spectroscopy, we determined the metabolic profile of living F. salina cells exposed to visible light and to polychromatic UV-B + UV-A + Vis radiation for several different exposure times. We used unsupervised pattern-recognition analysis to compare these profiles and discovered some metabolites whose concentration changed specifically upon UV exposure and in a dose-dependent manner. This variation was interpreted in terms of a two-phase cell reaction involving at least two different pathways: an early response consisting of degradation processes, followed by a late response activating osmoprotection mechanisms. The first step alters the concentration of formate, acetate, and saturated fatty-acid metabolites, whereas the osmoprotection modifies the activity of betaine moieties and other functionally related metabolites. In the latter pathway, alanine, proline, and sugars suggest a possible incipient protein synthesis as defense and/or degeneration mechanisms. We conclude that NMR spectroscopy on in vivo cells is an optimal approach for investigating the effect of UV-induced stress on the whole metabolome of F. salina because it minimizes the invasiveness of the measurement. PMID:21190674

  13. Psychological defense mechanisms in patients with syphilis at different stages of the disease

    Directory of Open Access Journals (Sweden)

    Filonova A.V.

    2015-09-01

    Full Text Available Purpose: the study of psychological defense mechanisms in patients with syphilis at different stages of the disease. Material and methods. We used questionnaire Plutchik-Kellerman-Comte "life style Index". The study involved 257 people (118 women (46% and 139 men (54% aged 18 to 67 years (mean age — 23,5±8,9years. Results. In patients with primary syphilis primary mecha-protection scheme is "denying"; secondary syphilis of skin and mucus-purity membranes— "replacement"; syphilis latent early — "projection"; in patients with late syphilis — intellectualization. Thus, in patients with late forms of syphilis is dominated by more Mature mechanisms of protection (projection, rationalization. Patients with early forms use more primitive mechanisms (denial, substitution. Conclusion. The obtained data may be useful in the choice of methods of psychotherapy, the formation of patients more realistic (ADAP-tive installations for the treatment, restoration of family and other social relations, the prevention of distress and improving the quality of life of patients.

  14. Mechanism study of organic antioxidant and inorganic salt on suppressing coal oxidation

    Institute of Scientific and Technical Information of China (English)

    YU Shui-jun; YU Ming-gao; JIA Hai-lin; ZUO Qiu-ling

    2007-01-01

    The advantages and disadvantages of Organic antioxidant and inorganic salt on suppressing coal oxidation were analyzed on the basis of the theory that coal oxidation mechanisms can be attributed to the free radical chain-type reaction mechanism.The inhibition curves on suppressing coal oxidation of the different type and different concentration of Organic antioxidant and inorganic salt were given through experimental study and data processing.Then some conclusions can be gained from the experimental study combining with theoretical analysis.First the inhibition mechanism of the organic antioxidant and inorganic salt is different.The former is that the chemical action is the dominant position.It can be called as the chain termination theory because the free radical is captured during coal oxidation.And the later is that the physical effect is the dominant position.It can be called as the decreasing-temperature theory because the liquid membrane which was formed by the inorganic salt can make coal body be the state of wetness and prevent oxygen from coal surface.Second the inhibition effect of the organic antioxidant is higher than the inorganic salt in the later period.But it is lower in the early period.

  15. Disruption of Nrf2, a key inducer of antioxidant defenses, attenuates ApoE-mediated atherosclerosis in mice.

    Directory of Open Access Journals (Sweden)

    Thomas E Sussan

    Full Text Available BACKGROUND: Oxidative stress and inflammation are two critical factors that drive the formation of plaques in atherosclerosis. Nrf2 is a redox-sensitive transcription factor that upregulates a battery of antioxidative genes and cytoprotective enzymes that constitute the cellular response to oxidative stress. Our previous studies have shown that disruption of Nrf2 in mice (Nrf2(-/- causes increased susceptibility to pulmonary emphysema, asthma and sepsis due to increased oxidative stress and inflammation. Here we have tested the hypothesis that disruption of Nrf2 in mice causes increased atherosclerosis. PRINCIPAL FINDINGS: To investigate the role of Nrf2 in the development of atherosclerosis, we crossed Nrf2(-/- mice with apoliporotein E-deficient (ApoE(-/- mice. ApoE(-/- and ApoE(-/-Nrf2(-/- mice were fed an atherogenic diet for 20 weeks, and plaque area was assessed in the aortas. Surprisingly, ApoE(-/-Nrf2(-/- mice exhibited significantly smaller plaque area than ApoE(-/- controls (11.5% vs 29.5%. This decrease in plaque area observed in ApoE(-/-Nrf2(-/- mice was associated with a significant decrease in uptake of modified low density lipoproteins (AcLDL by isolated macrophages from ApoE(-/-Nrf2(-/- mice. Furthermore, atherosclerotic plaques and isolated macrophages from ApoE(-/-Nrf2(-/- mice exhibited decreased expression of the scavenger receptor CD36. CONCLUSIONS: Nrf2 is pro-atherogenic in mice, despite its antioxidative function. The net pro-atherogenic effect of Nrf2 may be mediated via positive regulation of CD36. Our data demonstrates that the potential effects of Nrf2-targeted therapies on cardiovascular disease need to be investigated.

  16. Defense mechanisms of sargassacean species against the epiphytic red alga Neosiphonia harveyi.

    Science.gov (United States)

    Nakajima, Noboru; Ohki, Kaori; Kamiya, Mitsunobu

    2015-08-01

    Flora diversity and abundance of epiphytes are specific to their basiphyte species and may relate to variations in the defensive abilities of basiphytes. Thus, investigating the interactions between epiphytes and basiphytes is useful for a better understanding of the biological impact of epiphytism and the survival strategies of basiphytes. We examined the epiphyte density on five sargassacean species at six locations between two study sites, which showed that the epiphytic red alga Neosiphonia harveyi was remarkably less abundant on Sargassum siliquastrum at all locations. To assess its defense mechanism against N. harveyi, we performed bioassays of phlorotannins, which are considered effective in deterring fouling, by culturing sargassacean blades with N. harveyi carpospores and observed the process by which sargassacean blades remove epiphytes. When the carpospores were incubated with various concentrations of dissolved phlorotannins, settlement and germination were inhibited only at the highest concentrations (>0.1 g · L(-1) ), and this effect did not significantly differ among the five sargassacean species. When the carpospores were combined with blades from the five species, many of the spores attached and germinated on every blade. Because N. harveyi penetrated rhizoids into basiphyte tissues, cuticle peeling observed in all five sargassacean species could not remove this epiphyte after germination. However, in S. siliquastrum, the blade tissues around the germlings became swollen and disintegrative, and were removed together with the germlings. The spores normally grew on the dead blades, suggesting that the tissue degradation of S. siliquastrum is triggered by the infection of N. harveyi. PMID:26986791

  17. Future Climate CO2 Levels Mitigate Stress Impact on Plants: Increased Defense or Decreased Challenge?

    OpenAIRE

    AbdElgawad, Hamada; Zinta, Gaurav; Beemster, Gerrit T.S.; Janssens, Ivan A; Asard, Han

    2016-01-01

    Elevated atmospheric CO2 can stimulate plant growth by providing additional C (fertilization effect), and is observed to mitigate abiotic stress impact. Although, the mechanisms underlying the stress mitigating effect are not yet clear, increased antioxidant defenses, have been held primarily responsible (antioxidant hypothesis). A systematic literature analysis, including “all” papers [Web of Science (WoS)-cited], addressing elevated CO2 effects on abiotic stress responses and antioxidants (...

  18. Mechanism of melanosomes action in antioxidant reactions following optic irradiation

    Science.gov (United States)

    Lapina, Victoria A.; Dontsov, Alexander E.; Sakina, Natalia L.; Ostrovsky, Michail A.

    1996-05-01

    Hyphema is often associated with traumatic eye injuries. Its blood is subjected to considerable changes in aqueous humor and causes toxic effect on eye tissues. The metabolism disturbances in eye tissues unfavorably affecting their cell structures play a significant role in the development of pathologic conditions in cases of intraocular hemorrhages. This is to be attributed to the correlation of lipid peroxidation (LP) processes and antioxidant system (AOS) activity of both the cellular membrane and its environment necessary for maintaining cell homeostasis as a whole. The aim of the present work is an experimental study of LP processes of aqueous humor (AH) in total traumatic hyphema (TTH) after magnet-laser stimulation different doses (3 and 6 minutes). TTH and aqueous humor collection were made on the eyes on rabbit (Schinchilla) according to Krasnov A.M. under the local anaesthesia (dicaine 0.25%). The study of biochemical aqueous indices was carried out on healthy eyes and after development of hyphema on day 1, 3, 5, 7, 10, 14, 30, and 45. The animals were divided into three groups: in the first group the biochemical indices were defined in the aqueous humor in TTH; in the second and the third groups the similar investigation was carried out after magnet- laser radiation with 3 and 6 minutes exposition. The malonic dialdehyde (MDA) was defined according to Ishihara, Shiff's bases -- and their concentration was determined on the total amount of lipids (reagent kit of 'Lachema'). He-Ne laser (with power density of 0.05 mVt) was used, streaming impulsed magnet field voltage being 10 mTl. The magnet head of a magnet radiator was fixed 0.5 cm from the eye; laser beam being sent to the central hole of the magnet head. The duration of exposure was 3 minutes in the second group and 6 minutes in the third group, daily for 10 days. Significant increase of LP product concentration level with two clear ascending peaks was seen on the third and tenth days in the first

  19. Microbial Signature-Triggered Plant Defense Responses and Early Signaling Mechanisms

    Science.gov (United States)

    Wu, Shujing; Shan, Libo; He, Ping

    2014-01-01

    It has long been observed that microbial elicitors can trigger various cellular responses in plants. Microbial elicitors have recently been referred to as pathogen or microbe-associated molecular patterns (PAMPs or MAMPs) and remarkable progress has been made on research of their corresponding receptors, signaling mechanisms and critical involvement in disease resistance. Plants also generate endogenous signals due to the damage or wounds caused by microbes. These signals were originally called endogenous elicitors and subsequently renamed damage-associated molecular patterns (DAMPs) that serve as warning signals for infections. The cellular responses induced by PAMPs and DAMPs include medium alkalinization, ion fluxes across the membrane, reactive oxygen species (ROS) and ethylene production. They collectively contribute to plant pattern-triggered immunity (PTI) and play an important role in plant basal defense against a broad spectrum of microbial infections. In this review, we provide an update on multiple PTI responses and early signaling mechanisms and discuss its potential applications to improve crop disease resistance. PMID:25438792

  20. A host defense mechanism involving CFTR-mediated bicarbonate secretion in bacterial prostatitis.

    Directory of Open Access Journals (Sweden)

    Chen Xie

    Full Text Available BACKGROUND: Prostatitis is associated with a characteristic increase in prostatic fluid pH; however, the underlying mechanism and its physiological significance have not been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: In this study a primary culture of rat prostatic epithelial cells and a rat prostatitis model were used. Here we reported the involvement of CFTR, a cAMP-activated anion channel conducting both Cl(- and HCO(3(-, in mediating prostate HCO(3(- secretion and its possible role in bacterial killing. Upon Escherichia coli (E. coli-LPS challenge, the expression of CFTR and carbonic anhydrase II (CA II, along with several pro-inflammatory cytokines was up-regulated in the primary culture of rat prostate epithelial cells. Inhibiting CFTR function in vitro or in vivo resulted in reduced bacterial killing by prostate epithelial cells or the prostate. High HCO(3(- content (>50 mM, rather than alkaline pH, was found to be responsible for bacterial killing. The direct action of HCO(3(- on bacterial killing was confirmed by its ability to increase cAMP production and suppress bacterial initiation factors in E. coli. The relevance of the CFTR-mediated HCO(3(- secretion in humans was demonstrated by the upregulated expression of CFTR and CAII in human prostatitis tissues. CONCLUSIONS/SIGNIFICANCE: The CFTR and its mediated HCO(3(- secretion may be up-regulated in prostatitis as a host defense mechanism.

  1. Metal accumulation and antioxidant defenses in the freshwater fish Carassius auratus in response to single and combined exposure to cadmium and hydroxylated multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Highlights: • Cd and OH-MWCNTs have a synergistic effect on Carassius auratus. • OH-MWCNTs significantly increased Cd accumulation in liver after 12 d exposure. • Co-exposure to Cd and OH-MWCNTs evoked severe hepatic oxidative stress. - Abstract: The effects of cadmium, hydroxylated multi-walled carbon nanotubes, and their mixture on metal accumulation and antioxidant defenses were studied using the goldfish Carassius auratus as the test organism. The fish were exposed to 0.1 mg/L Cd, 0.5 mg/L OH-MWCNTs, or 0.1 mg/L Cd + 0.5 mg/L OH-MWCNTs for 3 and 12 days. Then, the Cd concentration was determined in the gill, liver and muscle. Moreover, hepatic antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), glutathione level and malondialdehyde content were also measured. A continuous accumulation of Cd was observed throughout the experimental period. Cd accumulation in tissues occurred in the following order: gill > liver > muscle at 3 days and liver > gill > muscle at 12 days. The concentrations of Cd in the livers of fish exposed to the combination of Cd + OH-MWCNTs were significantly higher than those in fish exposed to either single chemical after 12 d of exposure. Meanwhile, the mixture evoked severe oxidative stress in the exposed fish, as indicated by significant inhibition of SOD, CAT and GPx activity, a remarkable decrease in GSH level, and simultaneous elevation of MDA content. These results suggested that the effect of the combined factors on metal accumulation and oxidative stress biomarkers was more obvious than that of single factors at longer exposure durations

  2. Effect of fraxetin on antioxidant defense and stress proteins in human neuroblastoma cell model of rotenone neurotoxicity. Comparative study with myricetin and N-acetylcysteine

    International Nuclear Information System (INIS)

    Mitochondrial complex I inhibitor rotenone induces apoptosis through enhancing mitochondrial reactive oxygen species production. Recently, it has been shown that fraxetin (coumarin) and myricetin (flavonoid) have significant neuroprotective effects against apoptosis induced by rotenone, increase the total glutathione levels in vitro, and inhibit lipid peroxidation. Thus, these considerations prompted us to investigate the way in which fraxetin and myricetin affect the endogenous antioxidant defense system, such as Mn and CuZn superoxide dismutase (MnSOD, CuZnSOD), catalase, glutathione reductase (GR), and glutathione peroxidase (GPx) on rotenone neurotoxicity in neuroblastoma cells. N-acetylcysteine (NAC), a potent antioxidant, was employed as a comparative agent. Also, the expression and protein levels of HSP70 by Northern and Western blot analysis were assayed in SH-SY5Y cells. After incubation for 16 h, rotenone significantly increased the expression and activity of MnSOD, GPx, and catalase. When cells were preincubated with fraxetin, there was a decrease in the protein levels and activity of both MnSOD and catalase, in comparison with the rotenone treatment. The myricetin effect was less pronounced. Activity and expression of GPx were increased by rotenone and pre-treatment with fraxetin did not modify significantly these levels. The significant enhancement in HSP70 expression at mRNA and protein levels induced by fraxetin was observed by pre-treatment of cells 0.5 h before rotenone insult. These data suggest that major features of rotenone-induced neurotoxicity are partially mediated by free radical formation and oxidative stress, and that fraxetin partially protects against rotenone toxicity affecting the main protection system of the cells against oxidative injury

  3. Metal accumulation and antioxidant defenses in the freshwater fish Carassius auratus in response to single and combined exposure to cadmium and hydroxylated multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Ruijuan; Wang, Xinghao; Wang, Zunyao, E-mail: wangzun315cn@163.com; Wei, Zhongbo; Wang, Liansheng

    2014-06-30

    Highlights: • Cd and OH-MWCNTs have a synergistic effect on Carassius auratus. • OH-MWCNTs significantly increased Cd accumulation in liver after 12 d exposure. • Co-exposure to Cd and OH-MWCNTs evoked severe hepatic oxidative stress. - Abstract: The effects of cadmium, hydroxylated multi-walled carbon nanotubes, and their mixture on metal accumulation and antioxidant defenses were studied using the goldfish Carassius auratus as the test organism. The fish were exposed to 0.1 mg/L Cd, 0.5 mg/L OH-MWCNTs, or 0.1 mg/L Cd + 0.5 mg/L OH-MWCNTs for 3 and 12 days. Then, the Cd concentration was determined in the gill, liver and muscle. Moreover, hepatic antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), glutathione level and malondialdehyde content were also measured. A continuous accumulation of Cd was observed throughout the experimental period. Cd accumulation in tissues occurred in the following order: gill > liver > muscle at 3 days and liver > gill > muscle at 12 days. The concentrations of Cd in the livers of fish exposed to the combination of Cd + OH-MWCNTs were significantly higher than those in fish exposed to either single chemical after 12 d of exposure. Meanwhile, the mixture evoked severe oxidative stress in the exposed fish, as indicated by significant inhibition of SOD, CAT and GPx activity, a remarkable decrease in GSH level, and simultaneous elevation of MDA content. These results suggested that the effect of the combined factors on metal accumulation and oxidative stress biomarkers was more obvious than that of single factors at longer exposure durations.

  4. Silicon-enhanced resistance to cadmium toxicity in Brassica chinensis L. is attributed to Si-suppressed cadmium uptake and transport and Si-enhanced antioxidant defense capacity

    Energy Technology Data Exchange (ETDEWEB)

    Song Alin [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Zhaojun [Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Zhang Jie [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Xue Gaofeng; Fan Fenliang [Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Liang Yongchao, E-mail: ycliang@caas.ac.cn [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Key Laboratory of Oasis Eco-Agriculture, College of Agriculture, Shihezi University, Shihezi 832003 (China)

    2009-12-15

    A series of hydroponics experiments were performed to investigate roles of silicon (Si) in enhancing cadmium (Cd) tolerance in two pakchoi (Brassica chinensis L.) cultivars: i.e. cv. Shanghaiqing, a Cd-sensitive cultivar, and cv. Hangyoudong, a Cd-tolerant cultivar. Plants were grown under 0.5 and 5 mg Cd L{sup -1} Cd stress without or with 1.5 mM Si. Plant growth of the Cd-tolerant cultivar was stimulated at the lower Cd level, but was decreased at the higher Cd level when plants were treated with Cd for one week. However, Plant growth was severely inhibited at both Cd levels as stress duration lasted for up to three weeks. Plant growth of the Cd-sensitive cultivar was severely inhibited at both Cd levels irrespective of Cd stress duration. Addition of Si increased shoot and root biomass of both cultivars at both Cd levels and decreased Cd uptake and root-to-shoot transport. Superoxide dismutase, catalase and ascorbate peroxidase activities decreased, but malondialdehyde and H{sub 2}O{sub 2} concentrations increased at the higher Cd level, which were counteracted by Si added. Ascorbic acid, glutathione and non-protein thiols concentrations increased at the higher Cd level, which were further intensified by addition of Si. The effects of Si and Cd on the antioxidant enzyme activity were further verified by isoenzyme analysis. Silicon was more effective in enhancing Cd tolerance in the Cd-tolerant cultivar than in the Cd-sensitive cultivar. It can be concluded that Si-enhanced Cd tolerance in B. chinensis is attributed mainly to Si-suppressed Cd uptake and root-to-shoot Cd transport and Si-enhanced antioxidant defense activity.

  5. Silicon-enhanced resistance to cadmium toxicity in Brassica chinensis L. is attributed to Si-suppressed cadmium uptake and transport and Si-enhanced antioxidant defense capacity

    International Nuclear Information System (INIS)

    A series of hydroponics experiments were performed to investigate roles of silicon (Si) in enhancing cadmium (Cd) tolerance in two pakchoi (Brassica chinensis L.) cultivars: i.e. cv. Shanghaiqing, a Cd-sensitive cultivar, and cv. Hangyoudong, a Cd-tolerant cultivar. Plants were grown under 0.5 and 5 mg Cd L-1 Cd stress without or with 1.5 mM Si. Plant growth of the Cd-tolerant cultivar was stimulated at the lower Cd level, but was decreased at the higher Cd level when plants were treated with Cd for one week. However, Plant growth was severely inhibited at both Cd levels as stress duration lasted for up to three weeks. Plant growth of the Cd-sensitive cultivar was severely inhibited at both Cd levels irrespective of Cd stress duration. Addition of Si increased shoot and root biomass of both cultivars at both Cd levels and decreased Cd uptake and root-to-shoot transport. Superoxide dismutase, catalase and ascorbate peroxidase activities decreased, but malondialdehyde and H2O2 concentrations increased at the higher Cd level, which were counteracted by Si added. Ascorbic acid, glutathione and non-protein thiols concentrations increased at the higher Cd level, which were further intensified by addition of Si. The effects of Si and Cd on the antioxidant enzyme activity were further verified by isoenzyme analysis. Silicon was more effective in enhancing Cd tolerance in the Cd-tolerant cultivar than in the Cd-sensitive cultivar. It can be concluded that Si-enhanced Cd tolerance in B. chinensis is attributed mainly to Si-suppressed Cd uptake and root-to-shoot Cd transport and Si-enhanced antioxidant defense activity.

  6. Quantum Chemical Study on the Antioxidation Mechanism of Piceatannol and Isorhapontigenin toward Hydroxyl and Hydroperoxyl Radicals.

    Directory of Open Access Journals (Sweden)

    Yang Lu

    Full Text Available A systematic study of the antioxidation mechanisms behind hydroxyl (•OH and hydroperoxyl (•OOH radical scavenging activity of piceatannol (PIC and isorhapontigenin (ISO was carried out using density functional theory (DFT method. Two reaction mechanisms, abstraction (ABS and radical adduct formation (RAF, were discussed. A total of 24 reaction pathways of scavenging •OH and •OOH with PIC and ISO were investigated in the gas phase and solution. The thermodynamic and kinetic properties of all pathways were calculated. Based on these results, we evaluated the antioxidant activity of every active site of PIC and ISO and compared the abilities of PIC and ISO to scavenge radicals. According to our results, PIC and ISO may act as effective •OH and •OOH scavengers in organism. A4-hydroxyl group is a very important active site for PIC and ISO to scavenge radicals. The introducing of -OH or -OCH3 group to the ortho-position of A4-hydroxyl group would increase its antioxidant activity. Meanwhile, the conformational effect was researched, the results suggest that the presence and pattern of intramolecular hydrogen bond (IHB are considerable in determining the antioxidant activity of PIC and ISO.

  7. The oxidation mechanism of the antioxidant quercetin in nonaqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Sokolova, Romana, E-mail: romana.sokolova@jh-inst.cas.cz [J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, 18223 Prague (Czech Republic); Degano, Ilaria [Department of Chemistry and Industrial Chemistry, University of Pisa, Via Risorgimento 35, 56100 Pisa (Italy); Ramesova, Sarka; Bulickova, Jana; Hromadova, Magdalena; Gal, Miroslav; Fiedler, Jan [J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, 18223 Prague (Czech Republic); Valasek, Michal [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, 16610 Prague 6 (Czech Republic)

    2011-08-30

    The knowledge of the degradation pathways of natural dyes used in medieval textiles is necessary for the restoration of their original color. Quercetin, one of such colorants, reportedly yields the wide spectrum of oxidation products in different types of media. This study deals with electrochemical oxidation mechanism of quercetin in nonaqueous solution, which has not been yet attempted. The final oxidation product at the first oxidation wave was identified by HPLC-DAD and GC-MS techniques as 2-(3',4'-dihydroxybenzoyl)-2,4,6-trihydroxybenzofuran-3(2H)-one. The apparent two-electron process at the potential of the first oxidation wave yields current-voltage shapes with one-electron characteristics. The in situ spectroelectrochemistry measurements proved the oxidation mechanism leading through a short-lived anion radical. Two possibilities of the oxidation mechanism are discussed: two one-electron transfers, which do not have identical but similar redox potentials, or the presence of a disproportionation chemical reaction following the first one electron transfer. The quinone formed in either case is stable only on the time scale of a fast spectroelectrochemistry and undergoes fast hydroxylation reaction, where 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxybenzofuran-3-one is formed. This compound is oxidized at the potential of the second oxidation wave of quercetin.

  8. Implication of Fructans in Health: Immunomodulatory and Antioxidant Mechanisms

    Directory of Open Access Journals (Sweden)

    Elena Franco-Robles

    2015-01-01

    Full Text Available Previous studies have shown that fructans, a soluble dietary fiber, are beneficial to human health and offer a promising approach for the treatment of some diseases. Fructans are nonreducing carbohydrates composed of fructosyl units and terminated by a single glucose molecule. These carbohydrates may be straight or branched with varying degrees of polymerization. Additionally, fructans are resistant to hydrolysis by human digestive enzymes but can be fermented by the colonic microbiota to produce short chain fatty acids (SCFAs, metabolic by-products that possess immunomodulatory activity. The indirect role of fructans in stimulating probiotic growth is one of the mechanisms through which fructans exert their prebiotic activity and improve health or ameliorate disease. However, a more direct mechanism for fructan activity has recently been suggested; fructans may interact with immune cells in the intestinal lumen to modulate immune responses in the body. Fructans are currently being studied for their potential as “ROS scavengers” that benefit intestinal epithelial cells by improving their redox environment. In this review, we discuss recent advances in our understanding of fructans interaction with the intestinal immune system, the gut microbiota, and other components of the intestinal lumen to provide an overview of the mechanisms underlying the effects of fructans on health and disease.

  9. The oxidation mechanism of the antioxidant quercetin in nonaqueous media

    International Nuclear Information System (INIS)

    The knowledge of the degradation pathways of natural dyes used in medieval textiles is necessary for the restoration of their original color. Quercetin, one of such colorants, reportedly yields the wide spectrum of oxidation products in different types of media. This study deals with electrochemical oxidation mechanism of quercetin in nonaqueous solution, which has not been yet attempted. The final oxidation product at the first oxidation wave was identified by HPLC-DAD and GC-MS techniques as 2-(3',4'-dihydroxybenzoyl)-2,4,6-trihydroxybenzofuran-3(2H)-one. The apparent two-electron process at the potential of the first oxidation wave yields current-voltage shapes with one-electron characteristics. The in situ spectroelectrochemistry measurements proved the oxidation mechanism leading through a short-lived anion radical. Two possibilities of the oxidation mechanism are discussed: two one-electron transfers, which do not have identical but similar redox potentials, or the presence of a disproportionation chemical reaction following the first one electron transfer. The quinone formed in either case is stable only on the time scale of a fast spectroelectrochemistry and undergoes fast hydroxylation reaction, where 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxybenzofuran-3-one is formed. This compound is oxidized at the potential of the second oxidation wave of quercetin.

  10. Possible Mechanism of Murraya koenigii and Cinnamomum tamala With Reference to Antioxidants Activity

    Directory of Open Access Journals (Sweden)

    James Smerq

    2011-07-01

    Full Text Available Antioxidants are one of the most important nutraceutical compounds that have emerged from the recent decades of research in food science. The advances in this field have allowed a better understanding of the free radical damage of cellular constituents, such as lipids, proteins and DNA. Antioxidants and radical scavengers have a crucial role in the treatment or prevention of several diseases such as type 2 diabetes, atherosclerosis, cancer, cardiovascular disorders and neurodegenerative disorders. Restrictions on the use of synthetic antioxidants are being imposed because of their toxic properties. The present study is the continuation of a program aimed at investigation on antioxidant activity of extracts from medicinal plants and to identify alternative natural and safe sources of food antioxidant especially from plant origin. In this report the anti-peroxidative effect of alcoholic extract of Murraya koenigii and Cinnamomum tamala have been studied in rat liver homogenate where ferrous sulphate has been used as inducer to induce lipid per oxidation. On the basis of results, it could be concluded that TBARS production in normal condition group is very slow and it is very high in FeSO4 treated groups. Results further revealed that at lower doses, the rate of formation of TBARS is slow but grows as the level of dose is increased. Significant and moderate results were found from 0.40 mM to 0.80 mM of ferrous sulphate. The mechanisms underlying the beneficial effects may be related to the antioxidant effects of the polyphenols resulting in decreased free radical production.

  11. Evolution and development of gastropod larval shell morphology: experimental evidence for mechanical defense and repair.

    Science.gov (United States)

    Hickman, C S

    2001-01-01

    The structural diversity of gastropod veliger larvae offers an instructive counterpoint to the view of larval forms as conservative archetypes. Larval structure, function, and development are fine-tuned for survival in the plankton. Accordingly, the study of larval adaptation provides an important perspective for evolutionary-developmental biology as an integrated science. Patterns of breakage and repair in the field, as well as patterns of breakage in arranged encounters with zooplankton under laboratory conditions, are two powerful sources of data on the adaptive significance of morphological and microsculptural features of the gastropod larval shell. Shells of the planktonic veliger larvae of the caenogastropod Nassarius paupertus [GOULD] preserve multiple repaired breaks, attributed to unsuccessful zooplankton predators. In culture, larvae isolated from concentrated zooplankton samples rapidly repaired broken apertural margins and restored the "ideal" apertural form, in which an elaborate projection or "beak" covers the head of the swimming veliger. When individuals with repaired apertures were reintroduced to a concentrated mixture of potential zooplankton predators, the repaired margins were rapidly chipped and broken back. The projecting beak of the larval shell is the first line of mechanical defense, covering the larval head and mouth and potentially the most vulnerable part of the shell to breakage. Patterns of mechanical failure show that spiral ridges do reinforce the beak and retard breakage. The capacity for rapid shell repair and regeneration, and the evolution of features that resist or retard mechanical damage, may play a more prominent role than previously thought in enhancing the ability of larvae to survive in the plankton. PMID:11256430

  12. A Survey on Attacks and Defense Metrics of Routing Mechanism in Mobile Ad hoc Networks

    Directory of Open Access Journals (Sweden)

    K.P.Manikandan

    2011-03-01

    Full Text Available A Mobile Ad hoc Network (MANET is a dynamic wireless network that can be formed infrastructure less connections in which each node can act as a router. The nodes in MANET themselves are responsible for dynamically discovering other nodes to communicate. Although the ongoing trend is to adopt ad hoc networks for commercial uses due to their certain unique properties, the main challenge is the vulnerability to security attacks. In the presence of malicious nodes, one of the main challenges in MANET is to design the robust security solution that can protect MANET from various routing attacks. Different mechanisms have been proposed using various cryptographic techniques to countermeasure the routing attacks against MANET. As a result, attacks with malicious intent have been and will be devised to exploit these vulnerabilities and to cripple the MANET operations. Attack prevention measures, such as authentication and encryption, can be used as the first line of defense for reducing the possibilities of attacks. However, these mechanisms are not suitable for MANET resource constraints, i.e., limited bandwidth and battery power, because they introduce heavy traffic load to exchange and verifying keys. In this paper, we identify the existent security threats an ad hoc network faces, the security services required to be achieved and the countermeasures for attacks in routing protocols. To accomplish our goal, we have done literature survey in gathering information related to various types of attacks and solutions. Finally, we have identified the challenges and proposed solutions to overcome them. In our survey, we focus on the findings and related works from which to provide secure protocols for MANETs. However, in short, we can say that the complete security solution requires the prevention, detection and reaction mechanisms applied in MANET.

  13. Post-ejection nest-desertion of common cuckoo hosts : a second defense mechanism or avoiding reduced reproductive success?

    NARCIS (Netherlands)

    Moskat, Csaba; Rosendaal, Erik C.; Boers, Myra; Zoelei, Aniko; Ban, Miklos; Komdeur, Jan; Soler, M.

    2011-01-01

    Hosts of the common cuckoo (Cuculus canorus), an avian brood parasite, develop antiparasite defense mechanisms to increase their reproductive success. Ejection of the parasite egg and desertion of the parasitized nest are the most typical adaptations in response to brood parasitism, but nest deserti

  14. Impacts of Different Water Pollution Sources on Antioxidant Defense Ability in Three Aquatic Macrophytes in Assiut Province, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed A.A. Gadallah

    2014-08-01

    Full Text Available The present study was undertaken to evaluate the impacts of surface water pollution with wastes coming from sewage effluents (Site 2, agricultural runoff (Site 4 and oils and detergents factory (Site 3 on the stability of leaf membrane (measured as injury %, hydrogen peroxide (H2O2, ascorbic acid (Asc A, lipid peroxidation, chlorophyll (Chl content, soluble sugars (SS, soluble proteins (SP and total free amino acids (TAA of Cyperus alopeucroides, Persicaria salicifolia and Echinochloa stagnina. Concentration of H2O2, MDA and TAA were higher in the three plants collected from polluted sites as compared with those of plants grown in control Nile site (Site1. The opposite was true for Asc A, SS and SP where their concentrations reduced significantly in response to water pollution. Leaf membrane was more damaged (high injury % in plants exposed to wastes from different sources than in plants growing at control site. The results of this study indicated that water pollution reduced the oxidative defense abilities in the three plants through reduction of Asc A activities, enhancement of H2O2 production and increasing MDA accumulation. In addition it impaired the metabolic activity through lowering the SS and SP contents and enhancement of TAA accumulation and increase membrane injury. The over production of hydrogen peroxide by the studied aquatic plants under water pollution could be used as an oxygen source needed to oxidize the more resistant organic and inorganic pollutants and used for pollution control and municipal and industrial wastewater treatment.

  15. Toxic effects of crude-oil-contaminated soil in aquatic environment on Carassius auratus and their hepatic antioxidant defense system

    Institute of Scientific and Technical Information of China (English)

    WANG Yuanyuan; ZHOU Qixing; PENG Shengwei; MA Lena Q; NIU Xiaowei

    2009-01-01

    Under the indoor simulant conditions, toxic effects of crude-oil-contaminated soil which was put into aquatic environment on the young fishes Carassius auratus and their hepatic antioxidant system after a 20-d exposure were investigated. Results showed that the relationship between the mortality of C. auratus and the exposed doses could be divided to 3 phases: fishes exposed to the low dose groups (0.5--5.0 g/L) were dead due to the ingestion of crude-oil-contaminated soils in aquatic environment; at the medium dose groups (5.0--25.0 g/L) fishes were dead due to the penetration of toxic substances; at the high dose groups (25.0--50.0 g/L) fishes were dead due to environmental stress. The highest mortality and death speed were found in the 1.0 g/L dose group, and the death speed was sharply increased in the 50.0 g/L dose group in the late phase of the exposure. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) and the content of malaondialdehyde (MDA) in the hepatic tissues of C. auratus were induced significantly. The activity of SOD was first increased and then decreased, and was significantly inhibited in the 50.0 g/L dose group. The activity of CAT was highly induced, and restored to a little more than the control level when the exposed doses exceeded 10.0 g/L. The activity of GST was the most sensitive, it was significantly induced in all dose groups, and the highest elevation was up to 6 times in the 0.5 g/L dose group compared with the control. The MDA content was significantly elevated in the 50.0 g/L dose group, and the changes of the MDA content were opposite with the changes of the GST activity.

  16. Changes in Antioxidant Defense Capability and Lipid Profile after 12-Week Low- Intensity Continuous Training in Both Cigarette and Hookah Smokers: A Follow-Up Study.

    Directory of Open Access Journals (Sweden)

    Abdessalem Koubaa

    Full Text Available To examine the impact of low-intensity continuous training program on antioxidant defense capability and lipid profile in male cigarette or hookah smokers. Forty-three male adults participated in a 12-week continuous training program at an intensity of 40% of VO2max. All subjects were subjected to anthropometric, physical and biochemical tests before and after the training program. The increase of Glutathione reductase (GR and Superoxide dismutase (SOD is significant only for cigarette smokers (CS and hookah smokers (HS groups. The Malondialdehyde (MDA decrease and α-tocopherol increase are significant only for HS group. GPx was increased in NS, CS and HS by 2.6% (p< 0.01, 2% (p< 0.05 and 1.7% (p< 0.05 respectively. Likewise, significant improvements of high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C and TC/HDL-C ratio were observed in three groups. En contrast no significant changes were recorded in triglycerides (TG. Also, significant reduction of total cholesterol (TC for CS group (p< 0.01 and HS groups (p< 0.05. This continuous training program appears to have an important role in lipid levels improving and oxidative stress attenuation.

  17. Resistance to the Beneficial Metabolic Effects and Hepatic Antioxidant Defense Actions of Fibroblast Growth Factor 21 Treatment in Growth Hormone-Overexpressing Transgenic Mice

    Directory of Open Access Journals (Sweden)

    Ravneet K. Boparai

    2015-01-01

    Full Text Available Fibroblast growth factor 21 (FGF21 modulates a diverse range of biological functions, including glucose and lipid metabolism, adaptive starvation response, and energy homeostasis, but with limited mechanistic insight. FGF21 treatment has been shown to inhibit hepatic growth hormone (GH intracellular signaling. To evaluate GH axis involvement in FGF21 actions, transgenic mice overexpressing bovine GH were used. Expectedly, in response to FGF21 treatment control littermates showed metabolic improvements whereas GH transgenic mice resisted most of the beneficial effects of FGF21, except an attenuation of the innate hyperinsulinemia. Since FGF21 is believed to exert its effects mostly at the transcriptional level, we analyzed and observed significant upregulation in expression of various genes involved in carbohydrate and lipid metabolism, energy homeostasis, and antioxidant defense in FGF21-treated controls, but not in GH transgenics. The resistance of GH transgenic mice to FGF21-induced changes underlines the necessity of normal GH signaling for the beneficial effects of FGF21.

  18. A Defensive Mechanism Cross Layer Architecture for Manets to Identify and Correct Misbehaviour in Routing

    Directory of Open Access Journals (Sweden)

    G.S. Mamatha

    2012-02-01

    Full Text Available The emerging mobile technology has brought revolutionized changes in the computer era. One such technology of networking is Mobile Ad hoc Networks (MANETS, where the mobility and infrastructure less of the nodes takes predominant roles. These features make MANETS more vulnerable to attacks. As the research continues several aspects can be explored in this area. At the very first it can be the problem of how to make the cross layer detection of attacks more efficient and work well. Since every layer in the network deals with different type of attacks, a possible viewpoint to those attack scenarios can be presented so that it can be extended in the later part. It becomes necessary to figure out the security solution architecture if there are different detection results generated by different layers. Secondly, there should be a measure of the network metrics to show increased performance. The paper presents such a defensive mechanism cross layered architecture which strives to identify and correct misbehaviour in MANETS especially with respect to routing layer. The evaluation of the proposed solution is also givenwith results obtained to show the performance of the network.

  19. In Vitro Protective Effect and Antioxidant Mechanism of Resveratrol Induced by Dapsone Hydroxylamine in Human Cells.

    Directory of Open Access Journals (Sweden)

    Rosyana V Albuquerque

    Full Text Available Dapsone (DDS hydroxylamine metabolites cause oxidative stress- linked adverse effects in patients, such as methemoglobin formation and DNA damage. This study evaluated the ameliorating effect of the antioxidant resveratrol (RSV on DDS hydroxylamine (DDS-NHOH mediated toxicity in vitro using human erythrocytes and lymphocytes. The antioxidant mechanism was also studied using in-silico methods. In addition, RSV provided intracellular protection by inhibiting DNA damage in human lymphocytes induced by DDS-NHOH. However, whilst pretreatment with RSV (10-1000 μM significantly attenuated DDS-NHOH-induced methemoglobinemia, but it was not only significantly less effective than methylene blue (MET, but also post-treatment with RSV did not reverse methemoglobin formation, contrarily to that observed with MET. DDS-NHOH inhibited catalase (CAT activity and reactive oxygen species (ROS generation, but did not alter superoxide dismutase (SOD activity in erythrocytes. Pretreatment with RSV did not alter these antioxidant enzymes activities in erythrocytes treated with DDS-NHOH. Theoretical calculations using density functional theory methods showed that DDS-NHOH has a pro-oxidant effect, whereas RSV and MET have antioxidant effect on ROS. The effect on methemoglobinemia reversion for MET was significantly higher than that of RSV. These data suggest that the pretreatment with resveratrol may decrease heme-iron oxidation and DNA damage through reduction of ROS generated in cells during DDS therapy.

  20. Epiphytes modulate Posidonia oceanica photosynthetic production, energetic balance, antioxidant mechanisms and oxidative damage

    Directory of Open Access Journals (Sweden)

    Monya Mendes Costa

    2015-12-01

    Full Text Available Epiphytes impose physical barriers to light penetration into seagrass leaves causing shading, which may decrease the production of oxygen reactive species (ROS, but also constitute a physical aggression that may trigger the production of ROS, leading to oxidative damage. Here we investigate the effects of epiphytes on Posidonia oceanica under both interactive perspectives, light attenuation and oxidative stress. Specifically the role of epiphytes in net photosynthesis, chlorophyll a and b, photoprotection (Violaxanthin+Anteraxanthin+Zeaxanthin cycle, soluble sugar and starch contents, enzymatic (ascorbate peroxidase (APX and dehydroascorbate reductase (DHAR and global (trolox equivalent antioxidant capacity (TEAC and oxygen radical antioxidant capacity (ORAC antioxidant responses, phenolics and oxidative damage (malondialdehyde are tested. Leaves with epiphytes showed higher chlorophyll b and lower content in VAZ cycle carotenoids. Epiphyte shading was the probable reason for the lower VAZ de-epoxidation-ratio of leaves with epiphytes. In spite of being shaded, leaves with epiphytes showed higher antioxidant levels, indicating that epiphytes trigger the production of ROS. Both ORAC and TEAC and also APX and DHAR activities were higher in leaves with epiphytes, indicating that this response was related with its presence. Malondialdehyde concentrations also suggest oxidative damage caused by epiphytes. We conclude that the epiphyte load causes oxidative stress in P. oceanica and the mechanisms to scavenge ROS were not completely effective to avoid cell damage.

  1. Study of oxidative stress, homocysteine, copper & zinc in nephrotic syndrome: therapy with antioxidants, minerals and B-complex vitamins

    OpenAIRE

    Jyoti Dwivedi; Purnima Dey Sarkar

    2009-01-01

    Oxidative damage has been proposed as one of the possible mechanism involved in the nephrotic syndrome. Strengthening the defense system by antioxidants may provide protection against oxidative damage. Therefore, this study was carried out to investigate oxidant and antioxidant status with copper, zinc and homocysteine in nephrotic syndrome patients and the effect of antioxidants, minerals and B-complex vitamins on oxidant and antioxidant status. The blood samples were analyzed for quantitati...

  2. The Role of Big Five Personality Factors and Defense Mechanisms in Predicting Quality of Life in Sexually Dysfunctional Female Patients

    OpenAIRE

    Salary, S; Roshan, R.; M. moghaddathin

    2015-01-01

    Sexual dysfunction can lead to behavioral problems and reduction in a person's quality of life. In 50 % of patients with personality disorders, there is also sexual dysfunction. Psychoanalysis approach attributes the cause of sexual dysfunction to a kind of fundamental anxiety as well as the use of immature mechanisms in these patients. The purpose of this study was to investigate the role of big five personality traits and defensive mechanisms in predicting these patients' quality of life. S...

  3. The Role of Defense Mechanisms, Personality and Demographical Factors on Complicated Grief following Death of a loved one by Cancer

    Directory of Open Access Journals (Sweden)

    Isaac Rahimian-Boogar

    2015-10-01

    Full Text Available Objective: Identification of the risk factors and psychological correlates of prolonged grief disorder is vital for health promotions in relatives of persons who died of cancer. The aim of this research was to investigate the role of defense mechanisms, character dimension of personality and demographic factors on complicated grief following a loss of a family member to cancer .Method: A number of 226 persons who had lost a family member to cancer in a cancer institute at Tehran University of Medical Science were selected through compliance sampling and completed the Inventory of complicated Grief-Revised (ICG-R, the Defense Styles Questionnaire (DSQ, the Character dimension of Temperament and Character Inventory (TCI, and the Demographical questionnaire. Data were analyzed by stepwise multiple regression analysis, using the PASW version 18 .Results: Findings revealed that neurotic defense style had a significant positive predictive role in the complicated grief; and cooperativeness, age of the deceased person, self-transcendence and mature defense style had a significant negative predictive role in complicated grief (p<0.001. R2 was 0.73 for the final model (p<.001.Conclusion: The results revealed that two character dimensions (low cooperativeness and self-transcendence, high neurotic defense style and young age of the deceased person were involved in the psychopathological course of the complicated and prolonged grief. It was concluded that personality characteristics of the grieving persons and demographics of the deceased person should be addressed in designing tailored interventions for complicated grief.

  4. (1)H NMR and GC-MS Based Metabolomics Reveal Defense and Detoxification Mechanism of Cucumber Plant under Nano-Cu Stress.

    Science.gov (United States)

    Zhao, Lijuan; Huang, Yuxiong; Hu, Jerry; Zhou, Hongjun; Adeleye, Adeyemi S; Keller, Arturo A

    2016-02-16

    Because copper nanoparticles are being increasingly used in agriculture as pesticides, it is important to assess their potential implications for agriculture. Concerns have been raised about the bioaccumulation of nano-Cu and their toxicity to crop plants. Here, the response of cucumber plants in hydroponic culture at early development stages to two concentrations of nano-Cu (10 and 20 mg/L) was evaluated by proton nuclear magnetic resonance spectroscopy ((1)H NMR) and gas chromatography-mass spectrometry (GC-MS) based metabolomics. Changes in mineral nutrient metabolism induced by nano-Cu were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that nano-Cu at both concentrations interferes with the uptake of a number of micro- and macro-nutrients, such as Na, P, S, Mo, Zn, and Fe. Metabolomics data revealed that nano-Cu at both levels triggered significant metabolic changes in cucumber leaves and root exudates. The root exudate metabolic changes revealed an active defense mechanism against nano-Cu stress: up-regulation of amino acids to sequester/exclude Cu/nano-Cu; down-regulation of citric acid to reduce the mobilization of Cu ions; ascorbic acid up-regulation to combat reactive oxygen species; and up-regulation of phenolic compounds to improve antioxidant system. Thus, we demonstrate that nontargeted (1)H NMR and GC-MS based metabolomics can successfully identify physiological responses induced by nanoparticles. Root exudates metabolomics revealed important detoxification mechanisms. PMID:26751164

  5. Serine/threonine protein phosphatases: Multi-purpose enzymes in control of defense mechanisms

    OpenAIRE

    Bajsa, Joanna; Pan, Zhiqiang; Duke, Stephen O

    2011-01-01

    Depending on the threat to a plant, different pattern recognition receptors, such as receptor-like kinases, identify the stress and trigger action by appropriate defense response development.1,2 The plant immunity system primary response to these challenges is rapid accumulation of phytohormones, such as ethylene (ET), salicylic acid (SA), and jasmonic acid (JA) and its derivatives. These phytohormones induce further signal transduction and appropriate defenses against biotic threats.3,4 Phyt...

  6. ROS signaling, phytohormone signaling and toxin tolerance: defense mechanisms in Arabidopsis thaliana against Botrytis cinerea

    OpenAIRE

    Cui, Fuqiang

    2014-01-01

    To face the constant challenges from numerous pathogens in the environment, sophisticated defense systems have evolved in plants. Reactive oxygen species (ROS) and phytohormones are important cellular compounds that regulate plant defense systems to overcome biotic stresses from different pathogens. Against biotrophic pathogens, which require living host cells, hypersensitive cell death response (HR), a type of programed cell death mediated by ROS and salicylic acid (SA), is effective for imm...

  7. Transcriptional Profiles of Drought-Related Genes in Modulating Metabolic Processes and Antioxidant Defenses in Lolium multiflorum

    OpenAIRE

    Pan, Ling; Zhang, Xinquan; Wang, Jianping; Ma, Xiao; Zhou, Meiliang; Huang, Linkai; Nie, Gang; Wang, Pengxi; Yang, Zhongfu; Li, Ji

    2016-01-01

    Drought is a major environmental stress that limits growth and development of cool-season annual grasses. Drought transcriptional profiles of resistant and susceptible lines were studied to understand the molecular mechanisms of drought tolerance in annual ryegrass (Lolium multiflorum L.). A total of 4718 genes exhibited significantly differential expression in two L. multiflorum lines. Additionally, up-regulated genes associated with drought response in the resistant lines were compared with...

  8. Phosphoinositide and Inositolpolyphosphate Signalling in Defense Responses of Arabidopsis thaliana Challenged by Mechanical Wounding

    Institute of Scientific and Technical Information of China (English)

    Alina Mosblech; Sabine K(o)nig; Irene Stenzel; Peter Grzeganek; Ivo Feussner; Ingo Heilmann

    2008-01-01

    Various biochemical signals are implicated in Arabidopsis wound signalling,including jasmonic acid (JA),salicylic acid,auxin,and Ca2+.Here,we report on cross-talk of phytohormones with phosphoinositide signals not previously implicated in plant wound responses.Within 30 min of mechanical wounding of Arabidopsis rosette-leaves,the levels of the lipid-derived soluble inositolpolyphosphate,inositol 1,4,5-trisphosphate (InsP3),increased four to five-fold.Concomitantly,the precursor lipids,phosphatidylinositol 4,5-bisphosphate,phosphatidylinositol 4-phosphate and phosphatidylinositol transiently depleted,followed by re-synthesis after 30-60 min of stimulation.Increased InsP3 levels with wounding coincided with JA increases over the first hours of stimulation.In dde2-2-mutant plants deficient in JA biosynthesis,no InsP3 increase was observed upon wounding,indicating that JA was required for InsP3 formation,and InsP3 levels increased in wild-type plants challenged with sorbitol,increasing endogenous JA levels.In InsP 5-ptase plants with attenuated phosphoinositide signalling,the induction of wounding-inducible genes was diminished compared with wildtype plants,suggesting a role for phosphoinositide signalling in mediating plant wound responses.The gene-expression patterns suggest that phosphoinositides contribute to both JA-dependent and JA-independent aspects of wound signalling.Weight gain of Plutella xylostella caterpillars feeding on InsPS-ptase plants was increased compared with that of caterpillars feeding on wild-type plants.The ecophysiological relevance of phosphoinositide signals in plant defense responses to herbivory is discussed in light of recent findings of inositolpolyphosphate involvement in phytohormone-receptor function.

  9. The Ets Transcription Factor GABP Is a Component of the Hippo Pathway Essential for Growth and Antioxidant Defense

    Directory of Open Access Journals (Sweden)

    Hongtan Wu

    2013-05-01

    Full Text Available The transcriptional coactivator Yes-associated protein (YAP plays an important role in organ-size control and tumorigenesis. However, how Yap gene expression is regulated remains unknown. This study shows that the Ets family member GABP binds to the Yap promoter and activates YAP transcription. The depletion of GABP downregulates YAP, resulting in a G1/S cell-cycle block and increased cell death, both of which are substantially rescued by reconstituting YAP. GABP can be inactivated by oxidative mechanisms, and acetaminophen-induced glutathione depletion inhibits GABP transcriptional activity and depletes YAP. In contrast, activating YAP by deleting Mst1/Mst2 strongly protects against acetaminophen-induced liver injury. Similar to its effects on YAP, Hippo signaling inhibits GABP transcriptional activity through several mechanisms. In human liver cancers, enhanced YAP expression is correlated with increased nuclear expression of GABP. Therefore, we conclude that GABP is an activator of Yap gene expression and a potential therapeutic target for cancers driven by YAP.

  10. Role of the reacting free radicals on the antioxidant mechanism of curcumin

    Energy Technology Data Exchange (ETDEWEB)

    Galano, Annia, E-mail: agalano@prodigy.net.mx [Universidad Autonoma Metropolitana-Iztapalapa, Departamento de Quimica, Area de Quimica Analitica, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, C.P. 09340, Mexico D.F. (Mexico); Alvarez-Diduk, Ruslan; Ramirez-Silva, Maria Teresa; Alarcon-Angeles, Georgina; Rojas-Hernandez, Alberto [Universidad Autonoma Metropolitana-Iztapalapa, Departamento de Quimica, Area de Quimica Analitica, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, C.P. 09340, Mexico D.F. (Mexico)

    2009-09-18

    Density functional theory is used to study the antioxidant mechanism of curcumin. Five different mechanisms are considered: single electron transfer (SET), radical adduct formation (RAF), H atom transfer from neutral curcumin (HAT), H atom transfer from deprotonated curcumin (HAT-D), and sequential proton loss electron transfer (SPLET). The influence of the environment is investigated for polar and non-polar surroundings. The apparent contradictions among previous experimental results are explained by the role of the nature of the reacting free radical on the relative importance of the above mentioned mechanism. It is proposed that the curcumin + DPPH reaction actually takes place mainly through the SPLET mechanism, while the reaction with {sup {center_dot}}OCH{sub 3}, and likely with other alkoxyl radicals, is governed by the HAT mechanism. Branching ratios for the {sup {center_dot}}OCH{sub 3} + curcumin reaction are reported for the first time. The calculated overall rate constants for this reaction are 1.16 x 10{sup 10} (benzene) and 5.52 x 10{sup 9} (water) L mol{sup -1} s{sup -1}. The role of phenolic groups on the antioxidant activity of curcumin has been experimentally confirmed.

  11. Role of the reacting free radicals on the antioxidant mechanism of curcumin

    International Nuclear Information System (INIS)

    Density functional theory is used to study the antioxidant mechanism of curcumin. Five different mechanisms are considered: single electron transfer (SET), radical adduct formation (RAF), H atom transfer from neutral curcumin (HAT), H atom transfer from deprotonated curcumin (HAT-D), and sequential proton loss electron transfer (SPLET). The influence of the environment is investigated for polar and non-polar surroundings. The apparent contradictions among previous experimental results are explained by the role of the nature of the reacting free radical on the relative importance of the above mentioned mechanism. It is proposed that the curcumin + DPPH reaction actually takes place mainly through the SPLET mechanism, while the reaction with ·OCH3, and likely with other alkoxyl radicals, is governed by the HAT mechanism. Branching ratios for the ·OCH3 + curcumin reaction are reported for the first time. The calculated overall rate constants for this reaction are 1.16 x 1010 (benzene) and 5.52 x 109 (water) L mol-1 s-1. The role of phenolic groups on the antioxidant activity of curcumin has been experimentally confirmed.

  12. Gallic Acid Ameliorates Cyclophosphamide-Induced Neurotoxicity in Wistar Rats Through Free Radical Scavenging Activity and Improvement in Antioxidant Defense System.

    Science.gov (United States)

    Oyagbemi, Ademola Adetokunbo; Omobowale, Temidayo Olutayo; Saba, Adebowale Bernard; Olowu, Ebunoluwa Racheal; Dada, Racheal Omolola; Akinrinde, Akinleye Stephen

    2016-07-01

    Cyclophosphamide (CPA) is a widely used anticancer chemotherapeutic agent and its toxicity has been associated with its toxic metabolites phosphormide mustard. Therefore, the ameliorative effect of Gallic acid against neurotoxicity was examined in this study. Sixty rats were grouped into 10 rats per group. Group 1 received saline orally. Group 2 received CPA at 100 mg/kg single dose intraperitoneally on day 1. Groups 3 and 4 were treated with Gallic acid (GA) at 60 and 120 mg/kg body weight only for 10 days and also received a single dose of CPA (100 mg/kg) intraperitoneally on day 1, respectively. Rats in groups 5 and 6 received GA at 60 and 120 mg/kg body weight only for 10 days. Groups 3, 4, 5, and 6 received GA orally. The cerebellar and cerebral malondialdehyde (MDA) contents and hydrogen peroxide generation were significantly (p GST) activities were significantly (p < .05) reduced in CPA treated group. The activity of glutathione peroxidase (GPx) was significantly increased in rats that were treatment with CPA. Also, nitrite content was significantly elevated in the brain of rats that received the toxic dose of CPA. All these findings suggest that treatment with GA (60 and 120 mg/kg) ameliorated the neurotoxicity induced by CPA via reduction of oxidative stress and increase in antioxidant defense system. Combining all, chemotherapeutic agents with structure/function similar to GA could be of potential benefit to the pharmaceutical industries as an adjuvant in chemotherapy with little or no side effects. PMID:26716793

  13. Role of vitamin B6 status on antioxidant defenses, glutathione, and related enzyme activities in mice with homocysteine-induced oxidative stress

    Directory of Open Access Journals (Sweden)

    Cheng-Chin Hsu

    2015-04-01

    Full Text Available Background: Vitamin B6 may directly or indirectly play a role in oxidative stress and the antioxidant defense system. Objective: The purpose of this study was to examine the associations of vitamin B6 status with cysteine, glutathione, and its related enzyme activities in mice with homocysteine-induced oxidative stress. Design: Four-week-old male BALB/c mice were weighed and divided into one of four dietary treatment groups fed either a normal diet (as a control group and a homocysteine group, a vitamin B6-deficient diet (as a B6-deficient group, or a B6-supplemented diet (a pyridoxine-HCl-free diet supplemented with 14 mg/kg of pyridoxine-HCl, as a B6 supplement group for 28 days. Homocysteine thiolactone was then added to drinking water in three groups for 21 days to induce oxidative stress. At the end of the study, mice were sacrificed by decapitation and blood and liver samples were obtained. Results: Mice with vitamin B6-deficient diet had the highest homocysteine concentration in plasma and liver among groups. Significantly increased hepatic malondialdehyde levels were observed in the vitamin B6-deficient group. Among homocysteine-treated groups, mice with vitamin B6-deficient diet had the highest plasma glutathione concentration and relatively lower hepatic glutathione concentration. The glutathione peroxidase activities remained relatively stable in plasma and liver whether vitamin B6 was adequate, deficient, or supplemented. Conclusions: Mice with deficient vitamin B6 intakes had an aggravate effect under homocysteine-induced oxidative stress. The vitamin B6-deficient status seems to mediate the oxidative stress in connection with the redistribution of glutathione from liver to plasma, but not further affect glutathione-related enzyme activities in mice with homocysteine-induced oxidative stress.

  14. Proteome and Phosphoproteome Characterization Reveals New Response and Defense Mechanisms of Brachypodium distachyon Leaves under Salt Stress*

    OpenAIRE

    Lv, Dong-Wen; Subburaj, Saminathan; Cao, Min; Yan, Xing; Li, Xiaohui; Appels, Rudi; Sun, Dong-Fa; Ma, Wujun; Yan, Yue-Ming

    2013-01-01

    Salinity is a major abiotic stress affecting plant growth and development. Understanding the molecular mechanisms of salt response and defense in plants will help in efforts to improve the salt tolerance of crops. Brachypodium distachyon is a new model plant for wheat, barley, and several potential biofuel grasses. In the current study, proteome and phosphoproteome changes induced by salt stress were the focus. The Bd21 leaves were initially treated with salt in concentrations ranging from 80...

  15. Theoretical simulations on the antioxidant mechanism of naturally occurring flavonoid: A DFT approach

    Science.gov (United States)

    Praveena, R.; Sadasivam, K.

    2016-05-01

    Synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are found to be toxic, hence non-carcinogenic naturally occurring radical scavengers especially flavonoids have gained considerable importance in the past two decades. In the present investigation, the radical scavenging activity of C-glycosyl flavonoids is evaluated using theoretical approach which could broaden its scope in therapeutic applications. Gas and solvent phase studies of structural and molecular characteristics of C-glycosyl flavonoid, isovitexin is investigated through hydrogen atom transfer mechanism (HAT), Electron transfer-proton transfer (ET-PT) and Sequential proton loss electron transfer (SPLET) by Density functional theory (DFT) using hybrid parameters. The computed values of the adiabatic ionization potential, electron affinity, hardness, softness, electronegativity and electrophilic index indicate that isovitexin possess good radical scavenging activity. The behavior of different -OH groups in polyphenolic compounds is assessed by considering electronic effects of the neighbouring groups and the overall geometry of molecule which in turn helps in analyzing the antioxidant capacity of the polyphenolic molecule. The studies indicate that the H-atom abstraction from 4'-OH site is preferred during the radical scavenging process. From Mulliken spin density analysis and FMOs, B-ring is found to be more delocalized center and capable of electron donation. Comparison of antioxidant activity of vitexin and isovitexin leads to the conclusion that isovitexin acts as a better radical scavenger. This is an evidence for the importance of position of glucose unit in the flavonoid.

  16. Metabolomic analysis reveals mechanism of antioxidant butylated hydroxyanisole on lipid accumulation in Crypthecodinium cohnii.

    Science.gov (United States)

    Sui, Xiao; Niu, Xiangfeng; Shi, Mengliang; Pei, Guangsheng; Li, Jinghan; Chen, Lei; Wang, Jiangxin; Zhang, Weiwen

    2014-12-24

    The heterotrophic dinoflagellate alga Crypthecodinium cohnii is known to accumulate lipids with a high fraction of docosahexaenoic acid (DHA). In this study, we first evaluated two antioxidant compounds, butylated hydroxyanisole (BHA) and propyl gallate (PG), for their effects on lipid accumulation in C. cohnii. The results showed that antioxidant BHA could increase lipid accumulation in C. cohnii by 8.80% at a final concentration of 30 μM, while PG had no obvious effect on lipid accumulation at the tested concentrations. To decipher the molecular mechanism responsible for the increased lipid accumulation by BHA, we employed an integrated GC-MS and LC-MS metabolomic approach to determine the time-series metabolic profiles with or without BHA, and then subjected the metabolomic data to a principal component analysis (PCA) and a weighted gene coexpression network analysis (WGCNA) network analyses to identify the key metabolic modules and metabolites possibly relevant to the increased lipid accumulation. LC-MS analysis showed that several metabolites, including NADPH, could be important for the stimulation role of BHA on lipid accumulation. Meanwhile GC-MS and network analyses allowed identification of eight metabolic modules and nine hub metabolites possibly relevant to the stimulation role of BHA in C. cohnii. The study provided a metabolomics view of the BHA mode of action on lipid accumulation in C. cohnii, and the information could be valuable for a better understanding of antioxidant effects on lipid accumulation in other microalgae as well. PMID:25436856

  17. Growth, photosynthesis, and defense mechanism of antimony (Sb)-contaminated Boehmeria nivea L.

    Science.gov (United States)

    Chai, Li-Yuan; Mubarak, Hussani; Yang, Zhi-Hui; Yong, Wang; Tang, Chong-Jian; Mirza, Nosheen

    2016-04-01

    Ramie (Boehmeria nivea L.) is the oldest cash fiber crop in China and is widely grown in antimony (Sb) mining areas. To evaluate the extent of Sb resistance and tolerance, the growth, tolerance index (TI), Sb content in plant parts and in Hoagland solution, bioaccumulation factor (BF), photosynthesis, and physiological changes in Sb-contaminated B. nivea (20, 40, 80, and 200 mg L(-1) Sb) grown hydroponically were investigated. The Sb tolerance and resistance of ramie were clearly revealed by growth inhibition, a TI between 13 and 99 %, non-significant changes in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (photosystem II (PSII)) and single-photon avalanche diode (SPAD) value, a significant increase in Sb in plant parts, BF >1, and an increase in catalase (CAT) and malondialdehyde (MDA) at 200 mg L(-1) Sb. Under increasing Sb stress, nearly the same non-significant decline in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (PSII), relative quantum yield of photosystem II (φPSII), and photochemical quenching (qP), except for F v /F m at 20 mg L(-1) Sb, were recorded. SPAD values for chlorophyll under Sb stress showed an increasing trend, except for a slight decrease, i.e., continuous increase in MDA, superoxide dismutase (SOD), peroxidase (POD), and CAT activities were suppressed under Sb addition up to 40 mg L(-1) Sb and the addition of Sb enhanced enzyme production at 80 and 200 mg L(-1) Sb. A continuous decrease in SOD, POD, and CAT up to 40 mg L(-1) Sb and enhancements at ≥80 mg L(-1), along with the continuous enhancement of MDA activity and inhibited biomass production, clearly reveal the roles of these enzymes in detoxifying Sb stress and the defense mechanism of ramie at 80 mg L(-1) Sb. Thus, B. nivea constitutes a promising candidate for Sb phytoremediation at mining sites. PMID:26711292

  18. A novel mechanism for NETosis provides antimicrobial defense at the oral mucosa

    DEFF Research Database (Denmark)

    Mohanty, Tirthankar; Sjögren, Jonathan; Kahn, Fredrik;

    2015-01-01

    Neutrophils are essential for host defense at the oral mucosa and neutropenia or functional neutrophil defects lead to disordered oral homeostasis. We found that neutrophils from the oral mucosa harvested from morning saliva had released neutrophil extracellular traps (undergone NETosis) in vivo...

  19. Revised structure of trans-resveratrol: Implications for its proposed antioxidant mechanism.

    Science.gov (United States)

    Zarychta, Bartosz; Gianopoulos, Christopher G; Pinkerton, A Alan

    2016-03-01

    The crystal structure of trans-resveratrol has been redetermined by X-ray diffraction. The newly refined structure demonstrates that the previously reported, dynamically disordered hydrogen-bonding network is rather the superposition of two crystallographically independent molecules of trans-resveratrol. This latter arrangement possesses a well-defined hydrogen-bonding network in a unit cell of double the previously reported volume. While not meant as a criticism of the proposed antioxidant mechanism itself, the present studies clearly show that the X-ray diffraction data should no longer be used for its additional support. PMID:26856924

  20. Mechanical strength degradation of crosslinked polyethylene insulation by radiation and thermal stress. Effect of antioxidant concentration

    International Nuclear Information System (INIS)

    In Japan, the integrity of the cables installed in nuclear power plants is confirmed by the environmental qualification test in accordance with 'Recommended Practice of IEEJ', which is based on IEEE Std. 323 - 1974 and 383 - 1974. The project of 'Assessment of Cable Aging for Nuclear Power Plants' was carried out from FY2002 to FY2008 by Japan Nuclear Energy Safety Organization to establish the highly reliable cable evaluation method, which is based on the studies on the suitable accelerated aging tests, the appropriately assumed environmental condition and the integrity judgment method considering operating condition and aging in actual plants. The test materials for the cable included XLPE, EPR, silicone rubber (SIR), and more. As a result, 'Guide for Cable Environmental Qualification Test for Nuclear Power Plant' was issued in July 2009. In order to clarify the deterioration mechanism under thermal and radiation environment, specimens made of XLPE insulating material for typical cable insulation have been aged in acceleration conditions with elevated temperature and high dose radiation condition. To simulate long term aging, the antioxidant concentration has been changed. The oxidation rate and antioxidant concentration of the specimen have been measured as well as the mechanical breakdown strength of the specimens. We found the clear relationship between the mechanical strength and material property change as a step toward the sophistication of the evaluation method with accelerated aging test. (author)

  1. Environmental exposure to lead induces oxidative stress and modulates the function of the antioxidant defense system and the immune system in the semen of males with normal semen profile

    International Nuclear Information System (INIS)

    We investigated the associations between environmental exposure to lead and a repertoire of cytokines in seminal plasma of males with normal semen profile according to the WHO criteria. Based on the median lead concentration in seminal plasma, 65 samples were divided into two groups: low (LE) and high exposure to lead (HE). Differences in semen volume and the pH, count, motility and morphology of sperm cells were not observed between the examined groups. The total oxidant status value and the level of protein sulfhydryl groups as well as the activities of manganese superoxide dismutase and catalase were significantly higher in the HE group, whereas the total antioxidant capacity value and the activities of glutathione reductase and glutathione-S-transferase were depressed. IL-7, IL-10, IL-12, and TNF-α levels were significantly higher in the HE group compared with the LE group. Environmental exposure to lead is sufficient to induce oxidative stress in seminal plasma and to modulate antioxidant defense system. - Highlights: • Lead induces oxidative stress in seminal plasma in human. • Lead modulates antioxidant defense system in seminal plasma in human. • Lead does not change a Th1/Th2 imbalance in seminal plasma in human

  2. Environmental exposure to lead induces oxidative stress and modulates the function of the antioxidant defense system and the immune system in the semen of males with normal semen profile

    Energy Technology Data Exchange (ETDEWEB)

    Kasperczyk, Aleksandra; Dobrakowski, Michał [Dept. of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, Katowice, Jordana 19, 41-808 Zabrze (Poland); Czuba, Zenon P. [Dept. of Microbiology and Immunology, School of Medicine with the Division of Dentistry, Medical University of Silesia, Katowice, Jordana 19, 41-808 Zabrze (Poland); Horak, Stanisław [I-st Chair and Clin. Dept. of Gynecology, Obstetrics and Gynecological Oncology, School of Medicine with the Division of Dentistry, Medical University of Silesia, Katowice, Batorego 15, 41-902 Bytom (Poland); Kasperczyk, Sławomir, E-mail: kaslav@mp.pl [Dept. of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, Katowice, Jordana 19, 41-808 Zabrze (Poland)

    2015-05-01

    We investigated the associations between environmental exposure to lead and a repertoire of cytokines in seminal plasma of males with normal semen profile according to the WHO criteria. Based on the median lead concentration in seminal plasma, 65 samples were divided into two groups: low (LE) and high exposure to lead (HE). Differences in semen volume and the pH, count, motility and morphology of sperm cells were not observed between the examined groups. The total oxidant status value and the level of protein sulfhydryl groups as well as the activities of manganese superoxide dismutase and catalase were significantly higher in the HE group, whereas the total antioxidant capacity value and the activities of glutathione reductase and glutathione-S-transferase were depressed. IL-7, IL-10, IL-12, and TNF-α levels were significantly higher in the HE group compared with the LE group. Environmental exposure to lead is sufficient to induce oxidative stress in seminal plasma and to modulate antioxidant defense system. - Highlights: • Lead induces oxidative stress in seminal plasma in human. • Lead modulates antioxidant defense system in seminal plasma in human. • Lead does not change a Th1/Th2 imbalance in seminal plasma in human.

  3. Brief Report: Self-Harm Is Associated with Immature Defense Mechanisms but Not Substance Use in a Nonclinical Scottish Adolescent Sample

    Science.gov (United States)

    Brody, Stuart; Carson, Carron Maryjane

    2012-01-01

    It has been unclear whether adolescent deliberate self-harm (DSH) is more associated with substance use or with characterological impairments. Multivariate determination of (N = 114 Scottish adolescents) ever engaging in DSH (Youth Risk Behavior Survey) from alcohol use, other substance use, and immature defense mechanism use (Defense Style…

  4. ‘What is ‘Czech’ in Art in Bohemia? Alfred Woltmann and defensive mechanisms of Czech artistic historiography’

    Directory of Open Access Journals (Sweden)

    Jindrich Vybiral

    2013-06-01

    Full Text Available The art historian Alfred Woltmann (1841-1880 in a lecture delivered 1876 put forth a highly provocative thesis on the predominance of the German element in the art of the Bohemian capital. He created thereby the outlines of a highly problematic situation, the resolution of which for many decades formed one of the central themes of Czech art history. Scholarly conclusions that proved the inferiority of the Slavonic tribe – and could not be simply disproved – consequently formed an insurmountable barrier for the efforts of Czech nationalist scholarship. Psychology makes use of the concept of “frustration” for such cases. Reactions to frustration are most commonly the defensive or ego-defensive mechanisms first mentioned in 1894 by Sigmund Freud and later described more fully by his daughter Anna Freud. The individual manifesting the symptom attempts to “destroy” the barrier or to attack the source of frustration in order to renew his or her psychic balance and repair his or her damaged self-evaluation. The essay aspires to make use of Freud´s systematic analysis to sketch an overview of the unconscious defensive mechanisms to be discerned in Czech artistic historiography following in the wake of Woltmann’s lecture (aggression, escape into fantasy, dismissal, repression, compensation, rationalisation, auto-accusation.

  5. Leaf folding in a sensitive plant: A defensive thorn-exposure mechanism?

    OpenAIRE

    Eisner, Thomas

    1981-01-01

    Quantitative photographic evidence is presented indicating that in the sensitive plant Schrankia microphylla the leaf-folding response that accompanies the sensitive reaction results in a pronounced increase in thorn exposure. It is argued that in sensitive plants that are thorny, including other species of Schrankia, as well as Mimosa pudica, the plant in which the sensitive reaction is traditionally demonstrated, leaf folding may be a defensive adaptation.

  6. Antioxidant Vitamins and Their Use in Psychiatry

    Directory of Open Access Journals (Sweden)

    Betul Mazlum

    2012-12-01

    Full Text Available Oxidative stress can be defined as imbalance between prooxidant molecules produced during body metabolism and members of antioxidant system for favor of former. Oxidative stress, which is included in the pathogenesis of cancer, aging, cardiovascular and neurodegenerative disorders, is also considered for pathogenetic mechanisms underlying psychiatric disorders including schizophrenia, mood disorders, attention deficit hyperactivity disorder. Due to important role of antioxidant vitamins in antioxidant defense mechanisms, vitamin supplementation therapies are considered in addition to conventional treatment choices for psychiatric disorders. This paper will attempt to review the biochemical, molecular and genetic data on biological processes related to vitamins A, C and E. Besides, the circumstances under which the antioxidant vitamin supplementation could be used in psychiatry and the factors that should be taken into consideration during these therapies will be discussed.

  7. The Mechanism of Silicon and Silicon Carbide Making Carbon—containing Materials Antioxidize

    Institute of Scientific and Technical Information of China (English)

    TIANShouxin; SimThiamChee; 等

    1996-01-01

    The paper analyses redox reactions of an-tioxidants Si and SiC ete at different positions in the course of oxidation of carbon-containing materials,It is pointed out that redox reaction of antioxidants in oxidized-zone plays a very important part in antioxidation of carbon-con-taining materials,The reason why SiC can make carbon-containing material antioxide at thermodynamic temperature has been ex-plained,Experiment proves that antioxidants in oxidized zone can make carbon-containing materils antioxidize.

  8. Antioxidant responses of wheat plants under stress

    Directory of Open Access Journals (Sweden)

    Andréia Caverzan

    2016-03-01

    Full Text Available Abstract Currently, food security depends on the increased production of cereals such as wheat (Triticum aestivum L., which is an important source of calories and protein for humans. However, cells of the crop have suffered from the accumulation of reactive oxygen species (ROS, which can cause severe oxidative damage to the plants, due to environmental stresses. ROS are toxic molecules found in various subcellular compartments. The equilibrium between the production and detoxification of ROS is sustained by enzymatic and nonenzymatic antioxidants. In the present review, we offer a brief summary of antioxidant defense and hydrogen peroxide (H2O2 signaling in wheat plants. Wheat plants increase antioxidant defense mechanisms under abiotic stresses, such as drought, cold, heat, salinity and UV-B radiation, to alleviate oxidative damage. Moreover, H2O2 signaling is an important factor contributing to stress tolerance in cereals.

  9. Antioxidant responses of wheat plants under stress.

    Science.gov (United States)

    Caverzan, Andréia; Casassola, Alice; Brammer, Sandra Patussi

    2016-03-01

    Currently, food security depends on the increased production of cereals such as wheat (Triticum aestivum L.), which is an important source of calories and protein for humans. However, cells of the crop have suffered from the accumulation of reactive oxygen species (ROS), which can cause severe oxidative damage to the plants, due to environmental stresses. ROS are toxic molecules found in various subcellular compartments. The equilibrium between the production and detoxification of ROS is sustained by enzymatic and nonenzymatic antioxidants. In the present review, we offer a brief summary of antioxidant defense and hydrogen peroxide (H2O2) signaling in wheat plants. Wheat plants increase antioxidant defense mechanisms under abiotic stresses, such as drought, cold, heat, salinity and UV-B radiation, to alleviate oxidative damage. Moreover, H2O2 signaling is an important factor contributing to stress tolerance in cereals. PMID:27007891

  10. Modulation of pulmonary defense mechanisms by acute exposures to nitrogen dioxide. [Staphylococcus aureus; Proteus mirabilis; Pasteurella pneumotropica

    Energy Technology Data Exchange (ETDEWEB)

    Jakab, G.J.

    1987-02-01

    The effect of acute exposures to NO/sub 2/ on the antibacterial defenses of the murine lung was assessed following inhalation challenges with Staphylococcus aureus, Proteus mirabilis, and Pasteurella pneumotropica. With S. aureus pulmonary antibacterial defenses were suppressed at NO/sub 2/ levels of 4.0 ppm and greater. Exposure to 10.0 ppm enhanced the intrapulmonary killing of P. mirabilis which correlated with an increase in the phagocytic cell populations lavaged from the lungs; at 20.0 ppm bactericidal activity against P. mirabilis was impaired. Pulmonary antibacterial defenses against P. pneumotropica were impaired at 10.0 ppm which correlated with a decrease in the retrieved phagocytic lung cell population. Reversing the order of treatment (ie., NO/sub 2/ exposure prior to bacterial challenge) raised the threshold concentration for NO/sub 2/-induced impairment of intrapulmonary bacterial killing. With S. aureus the effect was not observed at 5.0 ppm but at 10.0 ppm and with P. mirabilis not at 20.0 ppm but at 30.0 ppm intrapulmonary killing was enhanced. Exposures up to 20.0 ppm of NO/sub 2/ did not effect the physical translocation mechanisms of the lung as quantitated by declines in pulmonary radiotracer activity following aerogenic challenge with /sup 32/P-labeled staphylococci.

  11. Caspase-8 activity is part of the BeWo trophoblast cell defense mechanisms against Trypanosoma cruzi infection.

    Science.gov (United States)

    Carrillo, Ileana; Droguett, Daniel; Castillo, Christian; Liempi, Ana; Muñoz, Lorena; Maya, Juan Diego; Galanti, Norbel; Kemmerling, Ulrike

    2016-09-01

    Congenital Chagas disease is caused by the protozoan parasite Trypanosoma cruzi that must cross the placental barrier during transmission. The trophoblast constitutes the first tissue in contact with the maternal-blood circulating parasite. Importantly, the congenital transmission rates are low, suggesting the presence of local placental defense mechanisms. Cellular proliferation and differentiation as well as apoptotic cell death are induced by the parasite and constitute part of the epithelial turnover of the trophoblast, which has been suggested to be part of those placental defenses. On the other hand, caspase-8 is an essential molecule in the modulation of trophoblast turnover by apoptosis and by epithelial differentiation. As an approach to study whether T. cruzi induced trophoblast turnover and infection is mediated by caspase-8, we infected BeWo cells (a trophoblastic cell line) with the parasite and determined in the infected cells the expression and enzymatic activity of caspase-8, DNA synthesis (as proliferation marker), β-human chorionic gonadotropin (β-hCG) (as differentiation marker) and activity of Caspase-3 (as apoptotic death marker). Parasite load in BeWo cells was measured by DNA quantification using qPCR and cell counting. Our results show that T. cruzi induces caspase-8 activity and that its inhibition increases trophoblast cells infection while decreases parasite induced cellular differentiation and apoptotic cell death, but not cellular proliferation. Thus, caspase-8 activity is part of the BeWo trophoblast cell defense mechanisms against T. cruzi infection. Together with our previous results, we suggest that the trophoblast turnover is part of local placental anti-parasite mechanisms. PMID:27328973

  12. Defensive Armor of Potato Tubers: Nonpolar Metabolite Profiling, Antioxidant Assessment, and Solid-State NMR Compositional Analysis of Suberin-Enriched Wound-Healing Tissues

    Science.gov (United States)

    Dastmalchi, Keyvan; Kallash, Linda; Wang, Isabel; Phan, Van C.; Huang, Wenlin; Serra, Olga; Stark, Ruth E.

    2016-01-01

    The cultivation, storage, and distribution of potato tubers are compromised by mechanical damage and suboptimal healing. To investigate wound-healing progress in cultivars with contrasting russeting patterns, metabolite profiles reported previously for polar tissue extracts were complemented by GC/MS measurements for nonpolar extracts and quantitative 13C NMR of interfacial solid suspensions. Potential marker compounds that distinguish cultivar type and wound-healing time point included fatty acids, fatty alcohols, alkanes, glyceryl esters, α,ω-fatty diacids, and hydroxyfatty acids. The abundant long-chain fatty acids in nonpolar extracts and solids from the smooth-skinned Yukon Gold cultivar suggested extensive suberin biopolymer formation; this hypothesis was supported by high proportions of arenes, alkenes, and carbonyl groups in the solid and among the polar markers. The absence of many potential marker classes in nonpolar Atlantic extracts and interfacial solids suggested a limited extent of suberization. Modest scavenging activities of all nonpolar extracts indicate that the majority of antioxidants produced in response to wounding are polar. PMID:26166447

  13. The role of disorders of the prooxidant-antioxidant system in diabetes etiopathology

    Directory of Open Access Journals (Sweden)

    Małgorzata Mrowicka

    2011-08-01

    Full Text Available Chronic hyperglycemia is believed to play a pivotal role in the development of diabetic complications. It was found that hyperglycemia triggered a number of mechanisms that evoke overproduction of reactive oxygen species (ROS. Diabetes mellitus is associated with an increased level of free radicals, disturbances of the enzymatic antioxidant defense system and lower concentration of exogenous antioxidants. In consequence, these abnormalities lead to a redox imbalance called oxidative stress. The aim of the present study is to summarize the role of reactive oxygen species and changes in the antioxidant defense system in the development of diabetic complications.

  14. Exposure of cerium oxide nanoparticles to kidney bean shows disturbance in the plant defense mechanisms

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Kidney bean roots uptake nCeO2 primarily without biotransformation. • Cerium reached the root vascular tissues through gaps in the Casparian strip. • On longer exposure to high concentration, roots demonstrate stress response. • In leaves, guaiacol peroxidase plays a major role in ROS scavenging. - Abstract: Overwhelming use of engineered nanoparticles demands rapid assessment of their environmental impacts. The transport of cerium oxide nanoparticles (nCeO2) in plants and their impact on cellular homeostasis as a function of exposure duration is not well understood. In this study, kidney bean plants were exposed to suspensions of ∼8 ± 1 nm nCeO2 (62.5 to 500 mg/L) for 15 days in hydroponic conditions. Plant parts were analyzed for cerium accumulation after one, seven, and 15 days of nCeO2 exposure. The primary indicators of stress like lipid peroxidation, antioxidant enzyme activities, total soluble protein and chlorophyll contents were studied. Cerium in tissues was localized using scanning electron microscopy and synchrotron μ-XRF mapping, and the chemical forms were identified using μ-XANES. In the root epidermis, cerium was primarily shown to exist as nCeO2, although a small fraction (12%) was biotransformed to Ce(III) compound. Cerium was found to reach the root vascular tissues and translocate to aerial parts with time. Upon prolonged exposure to 500 mg nCeO2/L, the root antioxidant enzyme activities were significantly reduced, simultaneously increasing the root soluble protein by 204%. In addition, leaf's guaiacol peroxidase activity was enhanced with nCeO2 exposure in order to maintain cellular homeostasis

  15. Exposure of cerium oxide nanoparticles to kidney bean shows disturbance in the plant defense mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, Sanghamitra [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN) (United States); Peralta-Videa, Jose R. [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN) (United States); Bandyopadhyay, Susmita [Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN) (United States); Castillo-Michel, Hiram [European Synchrotron Radiation Facility, B.P. 220-38043 Grenoble, Cedex (France); Hernandez-Viezcas, Jose-Angel [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN) (United States); Sahi, Shivendra [Department of Biology, Western Kentucky University, Bowling Green, KY 42101 (United States); Gardea-Torresdey, Jorge L., E-mail: jgardea@utep.edu [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN) (United States)

    2014-08-15

    Graphical abstract: - Highlights: • Kidney bean roots uptake nCeO{sub 2} primarily without biotransformation. • Cerium reached the root vascular tissues through gaps in the Casparian strip. • On longer exposure to high concentration, roots demonstrate stress response. • In leaves, guaiacol peroxidase plays a major role in ROS scavenging. - Abstract: Overwhelming use of engineered nanoparticles demands rapid assessment of their environmental impacts. The transport of cerium oxide nanoparticles (nCeO{sub 2}) in plants and their impact on cellular homeostasis as a function of exposure duration is not well understood. In this study, kidney bean plants were exposed to suspensions of ∼8 ± 1 nm nCeO{sub 2} (62.5 to 500 mg/L) for 15 days in hydroponic conditions. Plant parts were analyzed for cerium accumulation after one, seven, and 15 days of nCeO{sub 2} exposure. The primary indicators of stress like lipid peroxidation, antioxidant enzyme activities, total soluble protein and chlorophyll contents were studied. Cerium in tissues was localized using scanning electron microscopy and synchrotron μ-XRF mapping, and the chemical forms were identified using μ-XANES. In the root epidermis, cerium was primarily shown to exist as nCeO{sub 2}, although a small fraction (12%) was biotransformed to Ce(III) compound. Cerium was found to reach the root vascular tissues and translocate to aerial parts with time. Upon prolonged exposure to 500 mg nCeO{sub 2}/L, the root antioxidant enzyme activities were significantly reduced, simultaneously increasing the root soluble protein by 204%. In addition, leaf's guaiacol peroxidase activity was enhanced with nCeO{sub 2} exposure in order to maintain cellular homeostasis.

  16. Proteome and phosphoproteome characterization reveals new response and defense mechanisms of Brachypodium distachyon leaves under salt stress.

    Science.gov (United States)

    Lv, Dong-Wen; Subburaj, Saminathan; Cao, Min; Yan, Xing; Li, Xiaohui; Appels, Rudi; Sun, Dong-Fa; Ma, Wujun; Yan, Yue-Ming

    2014-02-01

    Salinity is a major abiotic stress affecting plant growth and development. Understanding the molecular mechanisms of salt response and defense in plants will help in efforts to improve the salt tolerance of crops. Brachypodium distachyon is a new model plant for wheat, barley, and several potential biofuel grasses. In the current study, proteome and phosphoproteome changes induced by salt stress were the focus. The Bd21 leaves were initially treated with salt in concentrations ranging from 80 to 320 mm and then underwent a recovery process prior to proteome analysis. A total of 80 differentially expressed protein spots corresponding to 60 unique proteins were identified. The sample treated with a median salt level of 240 mm and the control were selected for phosphopeptide purification using TiO2 microcolumns and LC-MS/MS for phosphoproteome analysis to identify the phosphorylation sites and phosphoproteins. A total of 1509 phosphoproteins and 2839 phosphorylation sites were identified. Among them, 468 phosphoproteins containing 496 phosphorylation sites demonstrated significant changes at the phosphorylation level. Nine phosphorylation motifs were extracted from the 496 phosphorylation sites. Of the 60 unique differentially expressed proteins, 14 were also identified as phosphoproteins. Many proteins and phosphoproteins, as well as potential signal pathways associated with salt response and defense, were found, including three 14-3-3s (GF14A, GF14B, and 14-3-3A) for signal transduction and several ABA signal-associated proteins such as ABF2, TRAB1, and SAPK8. Finally, a schematic salt response and defense mechanism in B. distachyon was proposed. PMID:24335353

  17. Changes in pulmonary antioxidant defence mechanisms during separate and combined treatment with paraquat and ionizing radiation

    International Nuclear Information System (INIS)

    Two-hundred-fifty white male Wistar rats were poisoned with a daily dose of 1/100 LD50 paraquat water solution, five days weekly, over a period of 4 months. Immediately after that the animals were exposed to a single whole-body irradiation with a dose rate of 2 and 4 Gy on a linear accelerator with photon energy 9 MeV and radiation power 2 Gy/min. The biological effects of the isolated and combined two factors on the pulmonary antioxidant defence mechanisms were studied from the 1st up to the 60th post-irradiation days. It was established that paraquat and ionizing radiation inhibited the enzyme activity of superoxide dismutase, catalase and glucose-6-phosphate dehydrogenase and decreased the content of non-protein weight groups in lung homogenate at an early stage. The combined application of both factors had a significant synergic effect

  18. The Transcriptome and Terpene Profile of Eucalyptus grandis Reveals Mechanisms of Defense Against the Insect Pest, Leptocybe invasa.

    Science.gov (United States)

    Oates, Caryn N; Külheim, Carsten; Myburg, Alexander A; Slippers, Bernard; Naidoo, Sanushka

    2015-07-01

    Plants have evolved complex defenses that allow them to protect themselves against pests and pathogens. However, there is relatively little information regarding the Eucalyptus defensome. Leptocybe invasa is one of the most damaging pests in global Eucalyptus forestry, and essentially nothing is known regarding the molecular mechanisms governing the interaction between the pest and host. The aim of the study was to investigate changes in the transcriptional landscape and terpene profile of a resistant and susceptible Eucalyptus genotype in an effort to improve our understanding of this interaction. We used RNA-seqencing to investigate transcriptional changes following L. invasa oviposition. Expression levels were validated using real-time quantitative PCR. Terpene profiles were investigated using gas chromatography coupled to mass spectometry on uninfested and oviposited leaves. We found 698 and 1,115 significantly differentially expressed genes from the resistant and susceptible interactions, respectively. Gene Ontology enrichment and Mapman analyses identified putative defense mechanisms including cell wall reinforcement, protease inhibitors, cell cycle suppression and regulatory hormone signaling pathways. There were significant differences in the mono- and sesquiterpene profiles between genotypes and between control and infested material. A model of the interaction between Eucalyptus and L. invasa was proposed from the transcriptomic and chemical data. PMID:25948810

  19. Mechanical Stress and Antioxidant Protection in the Retina of Hindlimb Suspended Rats

    Science.gov (United States)

    Glass, Aziza; Theriot, Corey A.; Alway, Stephen E.; Zanello, Susana B.

    2012-01-01

    It has been postulated that hindlimb suspension (HS) causes a cephalad fluid shift in quadrupeds similar to that occurring to humans in microgravity. Therefore, HS may provide a suitable animal model in which to recapitulate the ocular changes observed in the human Visual Impairment and Intracranial Pressure (VIIP) syndrome. This work reports preliminary results from a tissue sharing project using 34 week-old Brown Norway rats. Two different experiments compared normal posture controls and HS rats for 2 weeks and rats exposed to HS for 2 weeks but allowed to recover in normal posture for 2 additional weeks. The effects of two nutritional countermeasures, green tea extract (GT) and plant polyphenol resveratrol (Rv), were also evaluated. Green tea contains the antioxidant epigallocatechin gallate (EGCG). qPCR gene expression analysis of selected targets was performed on RNA from isolated retinas, and histologic analysis was done on one fixed eye per rat. The transcription factor early growth response protein 1 (Egr1) was upregulated almost 2-fold in HS retinas relative to controls (P = 0.059), and its expression returned to control levels after 2 weeks of recovery in normal posture (P = 0.023). HS-induced upregulation of Egr1 was attenuated (but not significantly) in retinas from rats fed an antioxidant rich (GT extract) diet. In rats fed the GT-enriched diet, antioxidant enzymes were induced, evidenced by the upregulation of the gene heme oxygenase 1 (Hmox1) (P = 0.042) and the gene superoxide dismutase 2 (Sod2) (P = 0.0001). Egr1 is a stretch-activated transcription factor, and the Egr1 mechanosensitive response to HS may have been caused by a change in the translaminal pressure and/or mechanical deformation of the eye globe. The observed histologic measurements of the various retinal layers in the HS rats were lower in value than those of the control animal (n = 1), however insufficient data were available for statistical analysis. Aquaporin 4, a water

  20. Effects of heat stress on antioxidant defense system, inflammatory injury, and heat shock proteins of Muscovy and Pekin ducks: evidence for differential thermal sensitivities

    OpenAIRE

    Zeng, Tao; Li, Jin-jun; Wang, De-qian; Li, Guo-qin; Wang, Gen-lin; Lu, Li-zhi

    2014-01-01

    Rising temperatures are severely affecting the mortality, laying performance, and meat quality of duck. Our aim was to investigate the effect of acute heat stress on the expression of heat shock proteins (HSPs: HSP90, 70, 60, 40, and 10) and inflammatory factors (nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2)) and antioxidant enzyme activity (superoxide dismutase (SOD), malondialdehybe (MDA), catalase (CAT), total antioxidant capacity (T-AOC)) in livers of ducks and to compare the the...

  1. Responses to falling lll: defense mechanisms used by women with Turner syndrome and variants

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Soares Chvatal

    2009-01-01

    Full Text Available BACKGROUND: Article extracted from the doctoral research entitled "Experiences of the infertility phenomenon by patients suffering from Turner syndrome and variants: a clinical-qualitative study" approved by the University of Campinas. OBJECTIVES: To understand the defenses employed by women suffering from TS and different ways of dealing with the disease. METHOD: Qualitative research with exploratory design, non-experimental. The instrument consisted of a semidirect psychological interview, involving 13 women, undergoing semestral medical follow-up at the Center for Integral Attention to Women's Health (CAISM, and whose sampling was determined by saturation. Data was interpreted using the psychodynamic approach along with an eclectic framework of theoretical references for discussion in the spirit of interdisciplinary approach. RESULTS:These women displayed psychosocial conflicts such as difficulties in interpersonal relationships; feelings of resignation, anger, impotence, devaluation and depression symptoms. Defenses used were: repression, denial, annulment, fantasizing, adaptation and sublimation. DISCUSSION: Women suffering from TS and variants must deal with the disease's organic and psychic implications that cause great suffering and often hinder a saner social insertion. In this case, the study's findings can guide ambulatory psychological support concomitantly to the routine clinical protocol.OBJETIVO:Conhecer as defesas utilizadas por mulheres com síndrome de Turner (ST ou formas variantes para lidar com a doença. MÉTODO: Pesquisa qualitativa com desenho exploratório, não experimental. O instrumento consistiu em entrevista psicológica semidirigida, aplicada em 13 mulheres, cuja amostragem deu-se por saturação, as quais fazem acompanhamento semestral no Centro de Atendimento Integral à Saúde da Mulher. Os dados foram interpretados utilizando-se da abordagem psicodinâmica, aliada a um quadro eclético de referenciais te

  2. Defense mechanisms against herbivory in Picea: sequence evolution and expression regulation of gene family members in the phenylpropanoid pathway

    Directory of Open Access Journals (Sweden)

    Porth Ilga

    2011-12-01

    phenylpropanoid pathway in the evolution of plant defense mechanisms against insect pests and provide substantial potential for the functional characterization of several not yet resolved alternative pathways in plant defenses.

  3. Future Climate CO2 Levels Mitigate Stress Impact on Plants: Increased Defense or Decreased Challenge?

    Science.gov (United States)

    AbdElgawad, Hamada; Zinta, Gaurav; Beemster, Gerrit T S; Janssens, Ivan A; Asard, Han

    2016-01-01

    Elevated atmospheric CO2 can stimulate plant growth by providing additional C (fertilization effect), and is observed to mitigate abiotic stress impact. Although, the mechanisms underlying the stress mitigating effect are not yet clear, increased antioxidant defenses, have been held primarily responsible (antioxidant hypothesis). A systematic literature analysis, including "all" papers [Web of Science (WoS)-cited], addressing elevated CO2 effects on abiotic stress responses and antioxidants (105 papers), confirms the frequent occurrence of the stress mitigation effect. However, it also demonstrates that, in stress conditions, elevated CO2 is reported to increase antioxidants, only in about 22% of the observations (e.g., for polyphenols, peroxidases, superoxide dismutase, monodehydroascorbate reductase). In most observations, under stress and elevated CO2 the levels of key antioxidants and antioxidant enzymes are reported to remain unchanged (50%, e.g., ascorbate peroxidase, catalase, ascorbate), or even decreased (28%, e.g., glutathione peroxidase). Moreover, increases in antioxidants are not specific for a species group, growth facility, or stress type. It seems therefore unlikely that increased antioxidant defense is the major mechanism underlying CO2-mediated stress impact mitigation. Alternative processes, probably decreasing the oxidative challenge by reducing ROS production (e.g., photorespiration), are therefore likely to play important roles in elevated CO2 (relaxation hypothesis). Such parameters are however rarely investigated in connection with abiotic stress relief. Understanding the effect of elevated CO2 on plant growth and stress responses is imperative to understand the impact of climate changes on plant productivity. PMID:27200030

  4. Antioxidative Potentials as a Protective Mechanism in Catharanthus roseus (L.) G.Don. Plants under Salinity Stress

    OpenAIRE

    Jaleel, Cheruth Abdul; Gopi, Ragupathi; MANIVANNAN, Paramasivam; Panneerselvam, Rajaram

    2007-01-01

    Antioxidant responses were analysed in Catharanthus roseus (L.) G.Don. under 0, 50 and 100 mM NaCl in order to investigate the plant´s protective mechanisms against long-term salt-induced oxidative stress. The NaCl treatments were repeated in 4 different stages of growth, i.e. 30, 45, 60 and 75 days after sowing (DAS). The plants were uprooted randomly 90 DAS and the non-enzymatic and enzymatic antioxidant potentials were analysed. High salinity caused a decrease in reduced glutathione (GSH) ...

  5. Boldine protects endothelial function in hyperglycemia-induced oxidative stress through an antioxidant mechanism.

    Science.gov (United States)

    Lau, Yeh Siang; Tian, Xiao Yu; Huang, Yu; Murugan, Dharmani; Achike, Francis I; Mustafa, Mohd Rais

    2013-02-01

    Increased oxidative stress is involved in the pathogenesis and progression of diabetes. Antioxidants are therapeutically beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1,10-dimethoxyaporphine) is a major alkaloid present in the leaves and bark of the boldo tree (Peumus boldus Molina), with known an antioxidant activity. This study examined the protective effects of boldine against high glucose-induced oxidative stress in rat aortic endothelial cells (RAEC) and its mechanisms of vasoprotection related to diabetic endothelial dysfunction. In RAEC exposed to high glucose (30 mM) for 48 h, pre-treatment with boldine reduced the elevated ROS and nitrotyrosine formation, and preserved nitric oxide (NO) production. Pre-incubation with β-NAPDH reduced the acetylcholine-induced endothelium-dependent relaxation; this attenuation was reversed by boldine. Compared with control, endothelium-dependent relaxation in the aortas of streptozotocin (STZ)-treated diabetic rats was significantly improved by both acute (1 μM, 30 min) and chronic (20mg/kg/daily, i.p., 7 days) treatment with boldine. Intracellular superoxide and peroxynitrite formation measured by DHE fluorescence or chemiluminescence assay were higher in sections of aortic rings from diabetic rats compared with control. Chronic boldine treatment normalized ROS over-production in the diabetic group and this correlated with reduction of NAD(P)H oxidase subunits, NOX2 and p47(phox). The present study shows that boldine reversed the increased ROS formation in high glucose-treated endothelial cells and restored endothelial function in STZ-induced diabetes by inhibiting oxidative stress and thus increasing NO bioavailability. PMID:23178655

  6. Clustered regularly interspaced short palindromic repeats (CRISPRs): the hallmark of an ingenious antiviral defense mechanism in prokaryotes

    NARCIS (Netherlands)

    Al-Attar, S.; Westra, E.R.; Oost, van der J.; Brouns, S.J.J.

    2011-01-01

    Many prokaryotes contain the recently discovered defense system against mobile genetic elements. This defense system contains a unique type of repetitive DNA stretches, termed Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs). CRISPRs consist of identical repeated DNA sequences (re

  7. Plant gamma-thionins: novel insights on the mechanism of action of a multi-functional class of defense proteins.

    Science.gov (United States)

    Pelegrini, Patrícia B; Franco, Octávio L

    2005-11-01

    This review focuses on the first plant defense protein class described in literature, with growth inhibition activity toward pathogens. These peptides were named gamma-thionins or defensins, which are small proteins that can be classified into four main subtypes according to their specific functions. Gamma-thionins are small cationic peptides with different and special abilities. They are able to inhibit digestive enzymes or act against bacteria and/or fungi. Current research in this area focuses particularly these two last targets, being the natural crop plant defenses improved through the use of transgenic technology. Here, we will compare primary and tertiary structures of gamma-thionins and also will analyze their similarities to scorpion toxins and insect defensins. This last comparison offers some hypothesis for gamma-thionins mechanisms of action against certain pathogens. This specific area has benefited from the recent determination of many gamma-thionin structures. Furthermore, we also summarize molecular interactions between plant gamma-thionins and fungi receptors, which include membrane proteins and lipids, shedding some light over pathogen resistance. Researches on gamma-thionins targets could help on plant genetic improvement for production of increased resistance toward pathogens. Thus, positive results recently obtained for transgenic plants and future prospects in the area are also approached. Finally, gamma-thionins activity has also been studied for future drug development, capable of inhibit tumor cell growth in human beings. PMID:16084753

  8. Effects of Irrigation Deficit and Application of Some Growth Regulators on Defense Mechanisms of Canola

    Directory of Open Access Journals (Sweden)

    Seyed Ahmad KALANTAR AHMADI

    2015-04-01

    Full Text Available A split-plot experiment arranged in a randomized complete blocks design with three replications was carried out in Safiabad Agricultural Research Center of Dezful in order to investigate the effects of foliar applications of ascorbic acid (AsA, salicylic acid (SA and methanol (Me, under deficit irrigation conditions, in canola; there were 3 levels of irrigation as the main factor (irrigation after 70 mm evaporation from the pan as control, cessation of irrigation at the flowering stage and cessation of irrigation at the appearance of siliques and 10 levels of foliar applications as sub-factor (100, 200 and 300 mg.l-1AsA; 100, 200 and 300 µM SA; 10, 20 and 30% (w/v methanol; and foliar application of distilled water as control. Foliar applications were made during both budding and initiation of flowering stages. Results indicated that antioxidant enzymes showed different responses to deficit irrigation and foliar application treatments. Maximum catalase (CAT and polyphenol oxidase (PPO activities were observed under cessation of irrigation at flowering stage and foliar application of 300 µM SA, while ascorbate peroxidase (APX reached its maximum activity under the same irrigation conditions and foliar application of 300 mg.l-1AsA. SA had more influence to increase in CAT and PPO activity under cessation of irrigation at flowering stage. The relative water content (RWC was also decreased due to the drought stress caused by the cessation of irrigation. Foliar application of SA (100 μM and Me (10% w/v had more influence to maintain RWC compared to ascorbic acid under irrigation cessation at flowering stage.

  9. Agent-Based Modeling and Simulation of Network Infrastructure Cyber-Attacks and Cooperative Defense Mechanisms

    OpenAIRE

    Kotenko, Igor

    2010-01-01

    This paper considered the approach to investigation of distributed cooperative cyberdefence mechanisms against network attacks. The approach is based on the simulation of network cyber-attacks (Distributed Denial of Service, network worms, botnets, etc.) and cyber-protection mechanisms which combines discrete-event simulation, multi-agent approach and packet-level simulation of network protocols. The environment developed is written in C++ and OMNeT++. It allows imitating a wide spectrum of r...

  10. A Systems Biology Approach to the Coordination of Defensive and Offensive Molecular Mechanisms in the Innate and Adaptive Host-Pathogen Interaction Networks.

    Science.gov (United States)

    Wu, Chia-Chou; Chen, Bor-Sen

    2016-01-01

    Infected zebrafish coordinates defensive and offensive molecular mechanisms in response to Candida albicans infections, and invasive C. albicans coordinates corresponding molecular mechanisms to interact with the host. However, knowledge of the ensuing infection-activated signaling networks in both host and pathogen and their interspecific crosstalk during the innate and adaptive phases of the infection processes remains incomplete. In the present study, dynamic network modeling, protein interaction databases, and dual transcriptome data from zebrafish and C. albicans during infection were used to infer infection-activated host-pathogen dynamic interaction networks. The consideration of host-pathogen dynamic interaction systems as innate and adaptive loops and subsequent comparisons of inferred innate and adaptive networks indicated previously unrecognized crosstalk between known pathways and suggested roles of immunological memory in the coordination of host defensive and offensive molecular mechanisms to achieve specific and powerful defense against pathogens. Moreover, pathogens enhance intraspecific crosstalk and abrogate host apoptosis to accommodate enhanced host defense mechanisms during the adaptive phase. Accordingly, links between physiological phenomena and changes in the coordination of defensive and offensive molecular mechanisms highlight the importance of host-pathogen molecular interaction networks, and consequent inferences of the host-pathogen relationship could be translated into biomedical applications. PMID:26881892

  11. Short-term anoxic conditioning hormesis boosts antioxidant defenses, lowers oxidative damage following irradiation and enhances male sexual performance in the Caribbean fruit fly, Anastrepha suspensa

    International Nuclear Information System (INIS)

    Most organisms are repeatedly exposed to oxidative stress from multiple sources throughout their lifetimes, potentially affecting all aspects of organismal performance. Here we test whether exposure to a conditioning bout of anoxia early in adulthood induces a hormetic response that confers resistance to oxidative stress and enhances male sexual performance later in life in the Caribbean fruit fly, Anastrepha suspensa. Anoxic conditioning of adults prior to emergence led to an increase in antioxidant capacity driven by mitochondrial superoxide dismutase and glutathione peroxidase. When exposed to gamma irradiation, a strong oxidative stressor, males that received anoxic conditioning had lower lipid and protein oxidative damage at sexual maturity. Anoxia conditioning led to greater male sexual competitiveness compared with unconditioned males when both were irradiated, although there was no effect of anoxia conditioning on mating competitiveness in unirradiated males. Anoxia also led to higher adult emergence rates and greater flight ability in irradiation-stressed flies while preserving steriity. Thus, hormetic treatments that increased antioxidant enzyme activity also improved male performance after irradiation, suggesting that antioxidant enzymes play an important role in mediating the relationship between oxidative stress and sexual selection. Furthermore, our work has important applied implications for the sterile insect technique (SIT), an environmentally friendly method of insect pest control where males are sterilized by irradiation and deployed in the field to disrupt pest populations via mating. We suggest that hormetic treatments specifically designed to enhance antioxidant activity may produce more sexually competitive sterile males, thus improving the efficacy and economy of SIT programs. (author)

  12. The immune system is limited by oxidative stress: Dietary selenium promotes optimal antioxidative status and greatest immune defense in pacu Piaractus mesopotamicus.

    Science.gov (United States)

    Biller-Takahashi, Jaqueline D; Takahashi, Leonardo S; Mingatto, Fábio E; Urbinati, Elisabeth C

    2015-11-01

    Reactive oxygen species (ROS) are reactive molecules containing oxygen, that form as byproducts of aerobic metabolism, including immune system processes. Too much ROS may cause oxidative stress. In this study, we examined whether it can also limit the production of immune system compounds. To assess the relationship between antioxidant status and immunity we evaluated the effect of dietary supplementation with organic selenium, given at various levels for 10 days, on the antioxidant and immune system of the pacu fish (Piaractus mesopotamicus). Fish fed a diet containing 0.6 mg Se-yeast kg(-1) showed significant improvement in antioxidant status, as well as in hematological and immunological profiles. Specifically, they had the highest counts for catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), red blood cells, and thrombocytes; the highest leukocyte count (particularly for monocytes); and the highest serum lysozyme activity. There was also a positive correlation between GPx and lysozyme in this group of fish. These findings indicate that short-term supplementation with 0.6 mg Se-yeast kg(-1) reestablished the antioxidative status, allowing the production of innate components which can boost immunity without the risk of oxidative stress. This study shows a relationship between oxidative stress and immunity, and, from a practical perspective, shows that improving immunity and health in pacu through the administration of selenium could improve their growth performance. PMID:26370542

  13. The calcification of staphylococcus aureus bacteria by the mineralization by inhibitor exclusion mechanism : a potential defense mechanism against bacterial infections

    OpenAIRE

    Truong, Linh Y.

    2011-01-01

    The emergence of antibiotic resistant bacteria has become a worldwide concern. Our goal was to develop a new strategy to treat antibiotic resistant bacterial infections. We investigated whether bacteria are killed by the Mineralization by Inhibitor Exclusion (MIE) mechanism. This mechanism exploits the size exclusion characteristics of the bacterial cell wall, and therefore has no impact on mammalian cells. Our studies demonstrate that live Staphylococcus aureus are calcified by the MIE mecha...

  14. Media effects on the mechanism of antioxidant action of silybin and 2,3-dehydrosilybin: role of the enol group.

    Science.gov (United States)

    van Wenum, Ewelina; Jurczakowski, Rafal; Litwinienko, Grzegorz

    2013-09-20

    Silybin (SIL) and 2,3-dehydrosilybin (DHS) are constituents of milk thistle extract (silymarin) applied in the treatment of cirrhosis, hepatitis, and alcohol-induced liver disease. The molecular mechanism of their action is usually connected with antioxidant action. However, despite experimental and theoretical evidence for the antioxidant activity of SIL and DHS, the mechanism of their antiradical action still remains unclear. We studied the kinetics of SIL/DHS reactions with 2,2-diphenyl-1-picrylhydrazyl radical in organic solutions of different polarity and with peroxyl radicals in a micellar system mimicking the amphiphilic environment of lipid membranes. Kinetic studies together with determination of acidity and electrochemical measurements allowed us to discuss the structure-activity relationship in detail. In nonpolar solvents the reaction with free radicals proceeds via a one-step hydrogen atom transfer (HAT) mechanism, while significant acceleration of the reaction rates in methanol and water/methanol solutions suggests the dominating contribution of a sequential proton-loss electron-transfer (SPLET) mechanism with participation of the most acidic hydroxyl groups: 7-OH in SIL and 7-OH and 3-OH in DHS. In a heterogeneous water/lipid system, both mechanisms operate; however, the reaction kinetics and the antioxidant efficacy depend on the partition between lipid and water phases. PMID:24006901

  15. Cross talk in defense signaling

    OpenAIRE

    Koornneef, A.; Pieterse, C.M.J.

    2008-01-01

    Plants are equipped with an array of defense mechanisms to protect themselves against attack by herbivorous insects and microbial pathogens. Some of these defense mechanisms are preexisting, whereas others are only activated upon insect or pathogen invasion. Induced defense responses entail fitness costs. Therefore, plants possess elaborate regulatory mechanisms that efficiently coordinate the activation of attackerspecific defenses so that fitness costs are minimized, while optimal resistanc...

  16. Biological defense mechanisms against DNA double-strand break and their possible medical applications

    International Nuclear Information System (INIS)

    Radiation is now widely used for clinical diagnosis and therapeutics. On the other hand, radiation influences various tissues represented by immunological and reproductive systems, and is also recognized as one of the cause of carcinogenesis. Such pleiotropic effects of radiation are mediated through generation of damages on DNA molecule, vitally important genetic macromolecule. Among various types of DNA damages, double-strand break (DSB) is considered most critical and, therefore, responsible for biological effects. DSB is repaired mainly through two pathways: non-homologous end joining (NHEJ) and homologous recombination (HR). Understanding of these mechanisms has been greatly deepened in past 20 years and is now providing a promising approach toward cancer therapy. We have studied the mechanisms of NHEJ, focusing especially on the role of phosphorylation and the assembly of machinery therein, which will be introduced below. (author)

  17. Physiological Defense Mechanism of Ligularia intermedia Against UV-B Radiation on Dongling Mountain

    Institute of Scientific and Technical Information of China (English)

    李鑫; 贾顺姬; 简嘉; 林孟仪; 李骑昂; 黄晓春; 张超; 张荣庆; 张贵友

    2003-01-01

    Ligularia intermedia growing at different altitudes were used to investigate the mechanism of ultraviolet (UV)-resistance on physiological aspects in the field.The tests compared the absorbance of the UV-absorbing compound, the content of chlorophyll a, chlorophyll b, and carotenoids, and the activities of peroxidase (POX) and superoxide dismutase (SOD) in Ligularia intermedia growing at three different altitudes on Dongling Mountain in northern China.There were no significant differences between the plants growing at 1160 m and 1820 m.However, all of these factors increased dramatically at 2190 m.The results indicate that the UV-resistance of the plants mainly depends on the mechanism of filtering the radiation and preventing the reactive oxygen species (ROS) damage produced by UV-B.

  18. In Vivo NMR Metabolic Profiling of Fabrea salina Reveals Sequential Defense Mechanisms against Ultraviolet Radiation

    OpenAIRE

    Marangoni, Roberto; Paris, Debora; Melck, Dominique; Fulgentini, Lorenzo; Colombetti, Giuliano; Motta, Andrea

    2011-01-01

    Fabrea salina is a hypersaline ciliate that is known to be among the strongest ultraviolet (UV)-resistant microorganisms; however, the molecular mechanisms of this resistance are almost unknown. By means of in vivo NMR spectroscopy, we determined the metabolic profile of living F. salina cells exposed to visible light and to polychromatic UV-B + UV-A + Vis radiation for several different exposure times. We used unsupervised pattern-recognition analysis to compare these profiles and discovered...

  19. Defensive Disclosure under Antitrust Enforcement

    OpenAIRE

    Bhaskarabhatla, Ajay; Pennings, Enrico

    2012-01-01

    textabstractWe formulate a simple model of optimal defensive disclosure by a monopolist facing uncertain antitrust enforcement and test its implications using unique data on defensive disclosures and patents by IBM during 1955-1989. Our results indicate that stronger antitrust enforcement leads to more defensive disclosure, that quality inventions are disclosed defensively, and that defensive disclosure served as an alternative but less successful mechanism to patenting at IBM in appropriatin...

  20. Defensive Disclosure under Antitrust Enforcement

    OpenAIRE

    Bhaskarabhatla, Ajay; Pennings, Enrico

    2012-01-01

    We formulate a simple model of optimal defensive disclosure by a dominant firm facing uncertain antitrust enforcement and test its implications using unique data on defensive disclosures and patents by IBM. Our results indicate that stronger antitrust enforcement leads to more defensive disclosure, that quality inventions are also disclosed defensively, and that defensive disclosure served as an alternative, but less successful, mechanism to patenting at IBM in appropriating returns from R&D....

  1. Antioxidant Defense Mechanisms in Pseudomonas aeruginosa: Role of Iron-Cofactored Superoxide Dismutase in Response to UV-C Radiations.

    Science.gov (United States)

    Ghorbal, Salma Kloula Ben; Maalej, Lobna; Chourabi, Kalthoum; Khefacha, Sana; Ouzari, Hadda-Imene; Chatti, Abdelwaheb

    2016-08-01

    The role of SOD gene in response to UV-C radiations was studied in Pseudomonas aeruginosa. Firstly, our results showed that the inactivation of sodM and/or sodB genes decreases the resistance of P. aeruginosa after exposure to UV-C rays. Furthermore, our results showed that SOD activity is dose dependant in all strains. However, significant increase in SOD activity was only shown at UV-C exposure time of 5 min in sodB mutant. At an elevated dose equivalent to 30 min of exposure, significant increase in SOD activity was observed in sodM. Catalase activities showed significant decrease in WT and in sodB mutant after an exposure time of 30 min. CAT enzyme was present at higher levels than SOD, reflecting that alternate enzymes such as POX, is poorly associated with CAT activity, and an increase in POX activity is related to increase in stress tolerance. The overall results showed that sodB gene has an important protective role against UV-C radiations in P. aeruginosa, compared to SodM isoform. PMID:27094998

  2. Effect of 1-methylcyclopropene and modified atmosphere packaging on chilling injury, and antioxidative defensive mechanism of sweet pepper

    Science.gov (United States)

    Sweet peppers (Capsicum annuum L.) are chilling sensitive vegetable, and develop injury when stored at temperatures less than 7 C. This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) (650 ppb) and modified atmosphere packaging (MAP) on chilling injuries of sweet pepper...

  3. Effect of Calendula officinalis Flower Extract on Acute Phase Proteins, Antioxidant Defense Mechanism and Granuloma Formation During Thermal Burns

    OpenAIRE

    Chandran, Preethi K.; Kuttan, Ramadasan

    2008-01-01

    Effect of Calendula officinalis flower extract was investigated against experimentally induced thermal burns in rats. Burn injury was made on the shaven back of the rats under anesthesia and the animals were treated orally with different doses of the flower extract (20 mg, 100 mg and 200 mg/kg body weight). The animals treated with the extract showed significant improvement in healing when compared with the control untreated animals. The indicators of the wound healing such as collagen-hydrox...

  4. Radiolysis study of the radical-like action mechanisms of an antioxidant: Sulfarlem

    International Nuclear Information System (INIS)

    Sulfarlem or p-anisyldithiolthione (ADT) is a sulfured heterocyclic compound which exhibits antioxidant properties. This work presents the quantitative study of the mono-electronic exchange mechanisms involved in this action. This study has been performed by gamma radiolysis and pulse radiolysis. The gamma radiolysis of ADT aerated ethanolic solutions has shown that O2. and RO2. radicals are not reactive towards ADT. In return, ADT is an efficient scavenger of R. radicals; the rate constant of this reaction being k (ADT + R.) = 6.7 x 104 mol-1.l.s-1. The pulse radiolysis experiments allowed the characterization of ADT reduction by the solvated electron (k (esolv- + ADT) = 2.3 x 1010 mol-1.l.s-1), the determination of the absorption spectrum of the reduced species A. (maximum wavelength = 580 nm) and the rate constant of its evolution (k (A. + A.) = 5.7 x 108 mol-1.l.s-1). An analogous study has been performed with ADO, an ADT oxidized derivative, which appeared to be a less efficient free radicals scavenger. (author)

  5. Antioxidant and Protective Mechanisms against Hypoxia and Hypoglycaemia in Cortical Neurons in Vitro

    Directory of Open Access Journals (Sweden)

    José Joaquín Merino

    2014-02-01

    Full Text Available In the present work, we have studied whether cell death could be induced in cortical neurons from rats subjected to different period of O2 deprivation and low glucose (ODLG. This “in vitro” model is designed to emulate the penumbra area under ischemia. In these conditions, cortical neurons displayed loss of mitochondrial respiratory ability however, nor necrosis neither apoptosis occurred despite ROS production. The absence of cellular death could be a consequence of increased antioxidant responses such as superoxide dismutase-1 (SOD1 and GPX3. In addition, the levels of reduced glutathione were augmented and HIF-1/3α overexpressed. After long periods of ODLG (12–24 h cortical neurons showed cellular and mitochondrial membrane alterations and did not recuperate cellular viability during reperfusion. This could mean that therapies directed toward prevention of cellular and mitochondrial membrane imbalance or cell death through mechanisms other than necrosis or apoptosis, like authophagy, may be a way to prevent ODLG damage.

  6. Neuroinflammatory contributions to pain after SCI: roles for central glial mechanisms and nociceptor-mediated host defense.

    Science.gov (United States)

    Walters, Edgar T

    2014-08-01

    Neuropathic pain after spinal cord injury (SCI) is common, often intractable, and can be severely debilitating. A number of mechanisms have been proposed for this pain, which are discussed briefly, along with methods for revealing SCI pain in animal models, such as the recently applied conditioned place preference test. During the last decade, studies of animal models have shown that both central neuroinflammation and behavioral hypersensitivity (indirect reflex measures of pain) persist chronically after SCI. Interventions that reduce neuroinflammation have been found to ameliorate pain-related behavior, such as treatment with agents that inhibit the activation states of microglia and/or astroglia (including IL-10, minocycline, etanercept, propentofylline, ibudilast, licofelone, SP600125, carbenoxolone). Reversal of pain-related behavior has also been shown with disruption by an inhibitor (CR8) and/or genetic deletion of cell cycle-related proteins, deletion of a truncated receptor (trkB.T1) for brain-derived neurotrophic factor (BDNF), or reduction by antisense knockdown or an inhibitor (AMG9810) of the activity of channels (TRPV1 or Nav1.8) important for electrical activity in primary nociceptors. Nociceptor activity is known to drive central neuroinflammation in peripheral injury models, and nociceptors appear to be an integral component of host defense. Thus, emerging results suggest that spinal and systemic effects of SCI can activate nociceptor-mediated host defense responses that interact via neuroinflammatory signaling with complex central consequences of SCI to drive chronic pain. This broader view of SCI-induced neuroinflammation suggests new targets, and additional complications, for efforts to develop effective treatments for neuropathic SCI pain. PMID:25017887

  7. Modulation of antioxidant enzymes as radioprotector mechanism of oligo elements and lachesis muta in normal tissues

    International Nuclear Information System (INIS)

    The therapeutic use of the ionizing radiations (IR) it has acquired great relevance in the last decades although their effects are not selective and they are also manifested on the normal tissues. In previous works we demonstrate the radioprotector effect that the combination of oligo elements Zinc, Selenium and Manganese associated to the snake poison Lachesis muta (O-LM) it exercises on the small intestine and the bone marrow of irradiated mouse. The objective of this work was to study the molecular mechanisms, and particularly the paper of the anti-oxidant superoxide dismutases enzymes (MnSOD and Cu/ZnSOD), Catalase (CAT), and Glutathione Peroxidase (GPx), in the radioprotector action that exercises the combination O-LM. Four groups of mice were used: A) control; B) treated with O-LM; C) irradiated; D) irradiated and treated with O-LM. The two treated groups were injected daily via s.c. with 0,1 ml of O-LM from 30 days before the irradiation and until to 4 days later. The two irradiated groups received 10 Gy in whole body the day 30. The day 35 all the animals were sacrificed. The histological intestinal cuts of the mucous one were evaluated by tint with hematoxyline-eosin; the presence of apoptotic cells it was determined by the Tunel method (Apoptag kit); the expression of PCNA (nuclear antigen of proliferating cells), MnSOD, CuZnSOD, CAT and GPx, by immunohistochemistry. The results demonstrated that in the lot D it was preserved totally the histology of the intestinal mucous. In the control A it was observed PCNA expression in the crypts, of MnSOD in the hairiness and CuZnSOD, CAT and Gpx in both. The change produced by O-LM (group B) it was the increase of PCNA, of CAT and the appearance of MnSOD in the crypts. On the other hand, the irradiation (C) it produced a marked descent in the GPx, the complete disappearance of PCNA and an increase of the apoptotic cells. The group D showed that O-LM it reverted totally the effect of the RI on the expression of PCNA

  8. Taurine protects methamphetamine-induced developmental angiogenesis defect through antioxidant mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Xue; Hu, Zhengtao; Hu, Chunyan; Bu, Qian; Yan, Guangyan [National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041 (China); Deng, Pengchi [Analytical and Testing Center, Sichuan University, Chengdu 610041 (China); Lv, Lei [National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041 (China); Wu, Dan [College of Basic and Forensic Medicine, Sichuan University, Chengdu 610041 (China); Deng, Yi; Zhao, Jinxuan; Zhu, Ruiming; Li, Yan; Li, Hongyu; Xu, Youzhi; Yang, Hanshuo; Zhao, Yinglan [National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041 (China); Cen, Xiaobo, E-mail: xbcenalan@vip.sina.com [National Chengdu Center for Safety Evaluation of Drugs, State Key Lab of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041 (China)

    2012-05-01

    Investigations have characterized addictive drug-induced developmental cardiovascular malformation in human, non-human primate and rodent. However, the underlying mechanism of malformation caused by drugs during pregnancy is still largely unknown, and preventive and therapeutic measures have been lacking. Using {sup 1}H NMR spectroscopy, we profiled the metabolites from human embryo endothelial cells exposed to methamphetamine (METH) and quantified a total of 226 peaks. We identified 11 metabolites modified robustly and found that taurine markedly increased. We then validated the hypothesis that this dramatic increase in taurine could attribute to its effect in inhibiting METH-induced developmental angiogenesis defect. Taurine supplement showed a more significant potential than other metabolites in protecting against METH-induced injury in endothelial cells. Taurine strongly attenuated METH-induced inhibition of proliferation and migration in endothelial cells. Furthermore, death rate and vessel abnormality of zebrafish embryos treated with METH were greatly reversed by taurine. In addition, taurine supplement caused a rapid decrease in reactive oxygen species generation and strongly attenuated the excitable arise of antioxidase activities in the beginning of METH exposure prophase. Dysregulations of NF-κB, p-ERK as well as Bax, which reflect apoptosis, cell cycle arrest and oxidative stress in vascular endothelium, were blocked by taurine. Our results provide the first evidence that taurine prevents METH-caused developmental angiogenesis defect through antioxidant mechanism. Taurine could serve as a potential therapeutic or preventive intervention of developmental vascular malformation for the pregnant women with drug use. Highlights: ► Metabonomics findings. ► Abnormal development. ► Dysregulations of key proteins.

  9. Taurine protects methamphetamine-induced developmental angiogenesis defect through antioxidant mechanism

    International Nuclear Information System (INIS)

    Investigations have characterized addictive drug-induced developmental cardiovascular malformation in human, non-human primate and rodent. However, the underlying mechanism of malformation caused by drugs during pregnancy is still largely unknown, and preventive and therapeutic measures have been lacking. Using 1H NMR spectroscopy, we profiled the metabolites from human embryo endothelial cells exposed to methamphetamine (METH) and quantified a total of 226 peaks. We identified 11 metabolites modified robustly and found that taurine markedly increased. We then validated the hypothesis that this dramatic increase in taurine could attribute to its effect in inhibiting METH-induced developmental angiogenesis defect. Taurine supplement showed a more significant potential than other metabolites in protecting against METH-induced injury in endothelial cells. Taurine strongly attenuated METH-induced inhibition of proliferation and migration in endothelial cells. Furthermore, death rate and vessel abnormality of zebrafish embryos treated with METH were greatly reversed by taurine. In addition, taurine supplement caused a rapid decrease in reactive oxygen species generation and strongly attenuated the excitable arise of antioxidase activities in the beginning of METH exposure prophase. Dysregulations of NF-κB, p-ERK as well as Bax, which reflect apoptosis, cell cycle arrest and oxidative stress in vascular endothelium, were blocked by taurine. Our results provide the first evidence that taurine prevents METH-caused developmental angiogenesis defect through antioxidant mechanism. Taurine could serve as a potential therapeutic or preventive intervention of developmental vascular malformation for the pregnant women with drug use. Highlights: ► Metabonomics findings. ► Abnormal development. ► Dysregulations of key proteins.

  10. Effects of heat stress on antioxidant defense system, inflammatory injury, and heat shock proteins of Muscovy and Pekin ducks: evidence for differential thermal sensitivities.

    Science.gov (United States)

    Zeng, Tao; Li, Jin-jun; Wang, De-qian; Li, Guo-qin; Wang, Gen-lin; Lu, Li-zhi

    2014-11-01

    Rising temperatures are severely affecting the mortality, laying performance, and meat quality of duck. Our aim was to investigate the effect of acute heat stress on the expression of heat shock proteins (HSPs: HSP90, 70, 60, 40, and 10) and inflammatory factors (nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2)) and antioxidant enzyme activity (superoxide dismutase (SOD), malondialdehybe (MDA), catalase (CAT), total antioxidant capacity (T-AOC)) in livers of ducks and to compare the thermal tolerance of Pekin and Muscovy ducks exposed to acute heat stress. Ducks were exposed to heat at 39 ± 0.5 °C for 1 h and then returned to 20 °C for 1 h followed by a 3-h recovery period. The liver and other tissues were collected from each individual for analysis. The mRNA levels of HSPs (70, 60, and 40) increased in both species, except for HSP10, which was upregulated in Muscovy ducks and had no difference in Pekin ducks after heat stress. Simultaneously, the mRNA level of HSP90 decreased in the stress group in both species. Morphological analysis indicated that heat stress induced tissue injury in both species, and the liver of Pekin ducks was severely damaged. The activities of several antioxidant enzymes increased in Muscovy duck liver, but decreased in Pekin duck. The mRNA levels of inflammatory factors were increased after heat stress in both duck species. These results suggested that heat stress could influence HSPs, inflammatory factors expression, and the activities of antioxidant enzymes. Moreover, the differential response to heat stress indicated that the Muscovy duck has a better thermal tolerance than does the Pekin duck. PMID:24796798

  11. New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate

    Directory of Open Access Journals (Sweden)

    Hae-Suk Kim

    2014-01-01

    Full Text Available Green tea is rich in polyphenol flavonoids including catechins. Epigallocatechin 3-gallate (EGCG is the most abundant and potent green tea catechin. EGCG has been extensively studied for its beneficial health effects as a nutriceutical agent. Based upon its chemical structure, EGCG is often classified as an antioxidant. However, treatment of cells with EGCG results in production of hydrogen peroxide and hydroxyl radicals in the presence of Fe (III. Thus, EGCG functions as a pro-oxidant in some cellular contexts. Recent investigations have revealed many other direct actions of EGCG that are independent from anti-oxidative mechanisms. In this review, we discuss these novel molecular mechanisms of action for EGCG. In particular, EGCG directly interacts with proteins and phospholipids in the plasma membrane and regulates signal transduction pathways, transcription factors, DNA methylation, mitochondrial function, and autophagy to exert many of its beneficial biological actions.

  12. Possible Mechanism of Murraya koenigii and Cinnamomum tamala With Reference to Antioxidants Activity

    OpenAIRE

    James Smerq; Mukta Sharma

    2011-01-01

    Antioxidants are one of the most important nutraceutical compounds that have emerged from the recent decades of research in food science. The advances in this field have allowed a better understanding of the free radical damage of cellular constituents, such as lipids, proteins and DNA. Antioxidants and radical scavengers have a crucial role in the treatment or prevention of several diseases such as type 2 diabetes, atherosclerosis, cancer, cardiovascular disorders and neurodegenerative disor...

  13. Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation

    OpenAIRE

    Ganesh Chandra Jagetia; Golgod Krishnamurthy Rajanikant

    2015-01-01

    Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain b...

  14. Natural and traditional defense mechanisms to reduce climate risks in coastal zones of Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammed Ataur Rahman

    2015-03-01

    Full Text Available Substantially resourceful and densely populated coastal zones of Bangladesh experience numerous extreme events linked to hydro-meteorological processes viz. cyclones, tidal surges, floods, salinity intrusion and erosion etc. These hazards give rise to extensive damage to property and loss of lives every year. Further, anthropogenic activities in the coastal zones are accentuating environmental degradation causing widespread suffering. Cyclones and tornadoes in particular damage infrastructures and crops every year affecting the economy of the country negatively. Some naturally adapted plants as well as landscapes usually reduce the speed of cyclones and tornadoes and thus, protect the coastal zones. However, human activities have destroyed many of the forests and landscapes. Sundarbans and Chokoria Sundarbans mangrove forests of Bangladesh are under a great threat of extinction due to illicit logging and agricultural expansion. At least 34 plant species of tropical forest are on the verge of extinction. Many animals e.g., cats, bears, porcupines, wild boars, pythons and anteaters are in the process of being wiped out from the coastal areas. Among the marine and coastal species, Red crabs, jelly-fish, sharks, and dolphins are also rare but these were the major species prior to 1980s. This study revealed that during the recent decades there has been massive plantations and construction of embankment and polderization but these and other measures have been found to be impractical and ineffective in reducing disasters in coastal areas. There is a need for integration of traditional coping practices and wisdoms with modern approaches. Available knowledge on some of these traditional practices has been documented for establishing a sustainable policy for management of coastal zones of Bangladesh. By combining traditional and scientific management of coastal ecosystem with mangroves and other plants following triple-tier mechanism and habitat, it is

  15. Using the Defensive Style Questionnaire to evaluate the impact of sex reassignment surgery on defensive mechanisms in transsexual patients Aplicação do Defensive Style Questionnaire para avaliar o impacto da cirurgia de redesignação sexual nos mecanismos de defesa de pacientes transexuais

    Directory of Open Access Journals (Sweden)

    Maria Inês Lobato

    2009-12-01

    Full Text Available Objective: To evaluate the impact of sex reassignment surgery on the defense mechanisms of 32 transsexual patients at two different points in time using the Defensive Style Questionnaire. Method: The Defensive Style Questionnaire was applied to 32 patients upon their admission to the Gender Identity Disorder Program, and 12 months after they had undergone sex reassignment surgery. Results: There were changes in two defense mechanisms: anticipation and idealization. However, no significant differences were observed in terms of the mature, neurotic and immature categories. Discussion: One possible explanation for this result is the fact that the procedure does not resolve gender dysphoria, which is a core symptom in such patients. Another aspect is related to the early onset of the gender identity disorder, which determines a more regressive defensive structure in these patients. Conclusion: Sex reassignment surgery did not improve the defensive profile as measured by the Defensive Style Questionnaire.Objetivo: Avaliar o efeito da cirurgia de redesignação sexual nos mecanismos de defesa de 32 pacientes transexuais em dois momentos do estudo usando o Defensive Style Questionnaire. Método: O Defensive Style Questionnaire foi aplicado a 32 pacientes quando ingressaram no Programa de Transtorno de Identidade de Gênero e 12 meses após a cirurgia de redesignação sexual. Resultados: Houve modificações em dois mecanismos de defesa: antecipação e idealização; porém, sem mudanças significativas nos fatores maduro, neurótico e imaturo. Discussão: Uma possibilidade para esse resultado é o fato de a intervenção cirúrgica não resolver a disforia de gênero (principal sintoma desses pacientes. Outro aspecto está relacionado com o fato de o transtorno de identidade de gênero ser instalado precocemente, o que determina uma estrutura defensiva mais regressiva para esses pacientes. Conclusão: A cirurgia de redesignação sexual não foi

  16. 黄柳菇总黄酮对过度训练大鼠抗氧化防御体系的影响%The Pholiota Adiposa Total Flavonoids on Exercise Capacity Andover- trained Rats the Antioxidant Defense System

    Institute of Scientific and Technical Information of China (English)

    杨智英; 吴鹤群

    2012-01-01

    To investigate the Pholiota adiposa total flavonoids on exercise capacity and over- trained rats the antioxidant defense system effects. The results showed that Pholiota adiposa total flavonoids in the intervention group exercise time to exhaustion was significantly longer than over- training exercise group, over- training exercise group decreased exercise capacity, and the tissue MDA content was significantly higher than the Pholiota adiposa total flavonoids in the intervention group ( P 〈 0.05 ) ; SOD, GSH - Px, and NOS activity were significantly lower than the Pholiota adiposa total flavonoids in the intervention group ( P 〈 0.05) . The Pholiota adiposa total flavonoids can significantly extend the time for exhaustive exercise in rats has increased the role of exercise capacity in rats, the Pholiota adiposa total flavonoids can mushroom movement in rat tissue SOD, GSH - Px, NOS activity increased, MDA content decreased, increased antioxidant capacity in rats, thus improving the antioxidant defense system in rat movement.%研究通过建立大鼠过度训练模型,观察黄柳菇总黄酮对过度训练大鼠运动能力及抗氧化防御体系的影响.研究结果表明,黄柳菇总黄酮千预下大鼠运动时间明显长于过度训练组,且各组织中丙二醛(MDA)含量显著低于过度训练组(P〈0.05),而超氧化物岐化酶(SOD)、谷胱甘肽过氧化物酶(GSH—Px)及一氧化氮合酶(NOS)的活性则显著高于过度训练组(P〈0.05).研究认为,黄柳菇总黄酮具有提高大鼠运动能力的作用,其机制可能与黄柳菇总黄酮通过提高大鼠抗氧化能力,改善运动大鼠抗氧化防御体系有关.

  17. Dietary alpha-ketoglutarate increases cold tolerance in Drosophila melanogaster and enhances protein pool and antioxidant defense in sex-specific manner.

    Science.gov (United States)

    Bayliak, Maria M; Lylyk, Maria P; Shmihel, Halyna V; Sorochynska, Oksana M; Manyukh, Oksana V; Pierzynowski, Stefan G; Lushchak, Volodymyr I

    2016-08-01

    Alpha-ketoglutarate (AKG) is an important intermediate in Krebs cycle which bridges the metabolism of amino acids and carbohydrates. Its effects as a dietary supplement on cold tolerance were studied in Drosophila melanogaster Canton S. Two-day-old adult flies fed at larval and adult stages with AKG at moderate concentrations (5-10mM) recovered faster from chill coma (0°C for 15min or 3h) than control ones. The beneficial effect of AKG on chill coma recovery was not found at its higher concentrations, which suggests hormetic like action of this keto acid. Time of 50% observed mortality after 2h recovery from continuous cold exposure (-1°C for 3-31h) (LTi50) was higher for flies reared on 10mM AKG compared with control ones, showing that the diet with AKG enhanced insect cold tolerance. In parallel with enhancement of cold tolerance, dietary AKG improved fly locomotor activity. Metabolic effects of AKG differed partly in males and females. In males fed on AKG, there were no differences in total protein and free amino acid levels, but the total antioxidant capacity, catalase activity and low molecular mass thiol content were higher than in control animals. In females, dietary AKG promoted higher total antioxidant capacity and higher levels of proteins, total amino acids, proline and low molecular mass thiols. The levels of lipid peroxides were lower in both fly sexes reared on AKG as compared with control ones. We conclude that both enhancement of antioxidant system capacity and synthesis of amino acids can be important for AKG-promoted cold tolerance in D. melanogaster. The involvement of AKG in metabolic pathways of Drosophila males and females is discussed. PMID:27503710

  18. Effect of long dose exposure of Podophyllum hexandrum methanol extract on antioxidant defense system and body and organ weight changes of albino rats

    Institute of Scientific and Technical Information of China (English)

    Showkat Ahmad Ganie; Bilal Ahmad Zargar; Akbar Masood; Mohmmad Afzal Zargar

    2012-01-01

    Objective: The present study was undertaken to investigate the effect of long dose administration of methanol rhizome extract of Podophyllum hexandrum and hydrogen peroxide on lipid peroxidation of erythrocytes, antioxidant enzyme status of rat liver, kidney, lung and brain tissue and body weight and organ weight changes of albino rats. Methods: The body and organ weight was monitored with digital scale balance and lipid peroxidation of RBC ghost membrane was monitored by measuring malonaldehyde (MDA). Antioxidant enzymes were assayed by standard procedures. Results: Our study showed that administration of H2O2 (0.1%) in drinking water of the rats for 25 weeks increased the malondialdehyde levels in erythrocytes of all the rats. However, rats receiving Podophyllum hexandrum extract and α- tocopherol had lower MDA levels in a dose dependent manner, which indicates decreased lipid peroxidation in these rats. Our results also showed decrease in the activity of glutathione reductase, glutathione-S-transferase and reduced glutathione levels in different organs of H2O2 treated rats. Rats receiving methanolic extract of Podophyllum hexandrum at the concentration of 5, 10 and 15mg% for 25 weeks increased the activity of glutathione reductase, glutathione-S-transferase and glutathione levels in different organs of the rats indicates the protective effect of the plant in combating oxidative stress undergone by the rats. No significant variation (P< 0.05) in the organ weights between the control and the treated groups was observed after 25 weeks of treatment. Conclusions: In conclusion, this study presents strong evidence of the nontoxic effect of the methanol extract of Podophyllumhexandrum. The findings also demonstrate that Podophyllum hexandrum methanol extract increased the levels of antioxidant enzymes and decreased lipid peroxidation in albino rats and explained the extensive utilization of the plant in traditional medicine.

  19. Age-related learning and memory deficits in rats: role of altered brain neurotransmitters, acetylcholinesterase activity and changes in antioxidant defense system

    OpenAIRE

    Haider, Saida; Saleem, Sadia; Perveen, Tahira; Tabassum, Saiqa; Batool, Zehra; Sadir, Sadia; Liaquat, Laraib; Madiha, Syeda

    2014-01-01

    Oxidative stress from generation of increased reactive oxygen species or free radicals of oxygen has been reported to play an important role in the aging. To investigate the relationship between the oxidative stress and memory decline during aging, we have determined the level of lipid peroxidation, activities of antioxidant enzymes, and activity of acetylcholine esterase (AChE) in brain and plasma as well as biogenic amine levels in brain from Albino–Wistar rats at age of 4 and 24 months. Th...

  20. Cellular responses induced by environmental stress factors in Arctic Seabird chicks : Responses of the antioxidant defense system and autophagic lysosomal processes related to contaminant exposure and food restriction

    OpenAIRE

    Hegseth, Marit Nøst

    2011-01-01

    The papers of this thesis are not available in Munin: 1. Marit Nøst Hegseth, Lionel Camus, Lisa Bjørnsdatter Helgason, Raffaella Bocchetti, Geir Wing Gabrielsen and Francesco Regoli: 'Hepatic antioxidant responses related to levels of PCBs and metals in chicks of three Arctic seabird species', Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology (2011) 154: 28-35. Available at http://dx.doi.org/10.1016/j.cbpc.2011.02.008 2. Marit Nøst Hegseth, Lionel Camus, Stefania Go...

  1. Action mechanism of antioxidation and anticorrosion and molecular design for perfluoropolyether fluid additives (I) --Action mechanism of additive and property of donating-accepting electron

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The combination energy and chemical adsorption energy of N-substituted perfluoropoly- alkyletherphenylamide (PFPEA) additive to perfluoropolyalkylether oxygen radical (RfO.) and to Fe atom have been calculated by quantum chemical methods. Structural characteristics, action mechanism, property of donating-accepting electron and substituent effect for antioxidant and anticorrosive additive are investigated. It is found that HOMO of the additives is a p-molecular orbital with lone pair electron of heteroatom. The HOMO of PFPEA additive reacts with LUMO of Fe atom to result in chemical adsorption. The LUMO of additive can interact with the SOMO of RfO. and accept electron of RfO. to form stable addition product. The additives have the property of donating-accepting electron. The electron-releasing group, particularly, the phenyl group, introduced to N atom of phenylamide can increase the combination energy and chemical adsorption energy, and enhance the antioxidant and anticorrosive efficiency. The research achievements can provide useful information for the designing of new antioxidant and anticorrosive additive. Based on the calculated results, antioxidant and anticorrosive efficiency can be predicted roughly as the following order: compounds III>II>I>IV>V.

  2. Studies on the biological effects of chemical defense mechanisms in vivo activated by low-dose irradiation

    International Nuclear Information System (INIS)

    Active oxygens produced by low-dose irradiation can induce the synthesis of proteins involved in the active oxygen reduction path and can activate the chemical self-defense mechanisms in vivo, which can alleviate the injuries caused by active oxygens themselves. The following findings suggests that it is not only by low-dose irradiation that can induce the responses described above but also by any physical and/or chemical stresses which can produce small amount of active oxygens in vivo. 1. X-irradiation with 0.5 Gy and/or water immersion and restraint induced heat shock protein (HSP)70 in rat stomach cells. HSP70 was also induced in adrenal cells by paraquat administration. 2. The SOD activity in pancreas of rat significantly increased by γ-irradiation with 0.5 Gy. 0.5 Gy irradiation preceeding the alloxan administration significantly suppressed the increase in pancreatic lipid peroxides and in blood glucose levels, degranulation in β cells, and decrease in blood insulin levels, respectively. 3. Inhalation of radon, which is a radioactive gaseous element and emits an α particle when it decays, significantly prevented the decrease in insulin levels and increase in glucose levels in blood of rabbit, respectively. (author). 85 refs

  3. A mechanical plant defense defines the opening of a phenological window for gall induction by Asphondylia aucubae (Cecidomyiidae: Diptera).

    Science.gov (United States)

    Imai, Kensuke; Ohsaki, Naota

    2009-04-01

    Many insect herbivores can only use hosts during a specific phenological stage, i.e., a phenological window. Previous studies have primarily examined the effects of these windows on insect herbivores, but relatively little is known about the mechanisms controlling the phenological windows. In most gall insect systems, phenological windows have been attributed to the short duration of physiologically active plant tissues that induce gall formation (reactive plant tissue). In the fruit gall midge, Asphondylia aucubae Yukawa and Ohsaki, and the host plant (i.e., Aucuba japonica) system, the disappearance of reactive plant tissue closes the phenological window, but its presence does not define the opening of the window. The hard endocarp of the fruit covers most potential oviposition sites just before the midge emergence season, but decreases in proportional cover during the emergence season. We experimentally manipulated the timing of oviposition relative to fruit development. Midges that emerged earliest and attacked fruits during their earliest developmental stages were unable to oviposit because of intact, hard endocarps, whereas their counterparts that emerged later could oviposit more readily through cracks in the endocarp. We noted possible oviposition avoidance behavior and the necessity of more frequent (repeated) ovipositor insertions to intensively stimulate the decreased reactive tissues during the latter half of the emergence season. Overall, our results indicated that the fragmentation of the defensive, hard endocarp of the host plant defines the opening of the phenological window in this plant-herbivore system. PMID:19389289

  4. Impact of proline application on cadmium accumulation, mineral nutrition and enzymatic antioxidant defense system of Olea europaea L. cv Chemlali exposed to cadmium stress.

    Science.gov (United States)

    Zouari, Mohamed; Ben Ahmed, Chedlia; Elloumi, Nada; Bellassoued, Khaled; Delmail, David; Labrousse, Pascal; Ben Abdallah, Ferjani; Ben Rouina, Bechir

    2016-06-01

    Proline plays an important role in plant response to various environmental stresses. However, its involvement in mitigation of heavy metal stress in plants remains elusive. In this study, we examined the effectiveness of exogenous proline (10 and 20mM) in alleviating cadmium induced inhibitory effects in young olive plants (Olea europaea L. cv. Chemlali) exposed to two Cd levels (10 and 30mg CdCl2kg(-1) soil). The Cd treatment induced substantial accumulation of Cd in both root and leaf tissues and a decrease in gas exchange, photosynthetic pigments contents, uptake of essential elements (Ca, Mg and K) and plant biomass. Furthermore, an elevation of antioxidant enzymes activities (superoxide dismutase, catalase, glutathione peroxydase) and proline content in association with relatively high amounts of hydrogen peroxide, thiobarbituric acid reactive substances and electrolyte leakage were observed. Interestingly, the application of exogenous proline alleviated the oxidative damage induced by Cd accumulation. In fact, Cd-stressed olive plants treated with proline showed an increase of antioxidant enzymes activities, photosynthetic activity, nutritional status, plant growth and oil content of olive fruit. Generally, it seems that proline supplementation alleviated the deleterious effects of young olive plants exposed to Cd stress. PMID:26946284

  5. Defense styles of pedophilic offenders.

    Science.gov (United States)

    Drapeau, Martin; Beretta, Véronique; de Roten, Yves; Koerner, Annett; Despland, Jean-Nicolas

    2008-04-01

    This pilot study investigated the defense styles of pedophile sexual offenders. Interviews with 20 pedophiles and 20 controls were scored using the Defense Mechanisms Rating Scales. Results showed that pedophiles had a significantly lower overall defensive functioning score than the controls. Pedophiles used significantly fewer obsessional-level defenses but more major image-distorting and action-level defenses. Results also suggested differences in the prevalence of individual defenses where pedophiles used more dissociation, displacement, denial, autistic fantasy, splitting of object, projective identification, acting out, and passive aggressive behavior but less intellectualization and rationalization. PMID:17875603

  6. Euterpe edulis Extract but Not Oil Enhances Antioxidant Defenses and Protects against Nonalcoholic Fatty Liver Disease Induced by a High-Fat Diet in Rats

    Directory of Open Access Journals (Sweden)

    Rodrigo Barros Freitas

    2016-01-01

    Full Text Available We investigated the effects of E. edulis bioproducts (lyophilized pulp [LEE], defatted lyophilized pulp [LDEE], and oil [EO] on nonalcoholic fatty liver disease (NAFLD induced by a high-fat diet (HFD in rats. All products were chemically analyzed. In vivo, 42 rats were equally randomized into seven groups receiving standard diet, HFD alone or combined with EO, LEE, or LDEE. After NAFLD induction, LEE, LDEE, or EO was added to the animals’ diet for 4 weeks. LEE was rich in polyunsaturated fatty acids. From LEE degreasing, LDEE presented higher levels of anthocyanins and antioxidant capacity in vitro. Dietary intake of LEE and especially LDEE, but not EO, attenuated diet-induced NAFLD, reducing inflammatory infiltrate, steatosis, and lipid peroxidation in liver tissue. Although both E. edulis bioproducts were not hepatotoxic, only LDEE presented sufficient benefits to treat NAFLD in rats, possibly by its low lipid content and high amount of phenols and anthocyanins.

  7. Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation.

    Science.gov (United States)

    Jagetia, Ganesh Chandra; Rajanikant, Golgod Krishnamurthy

    2015-01-01

    Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain better therapeutic gains. Curcumin is an antioxidant and a free radical scavenging dietary supplement, commonly used as a flavoring agent in curries. Therefore, the effect of 100 mg/kg body weight curcumin was studied on the antioxidant status of mice skin exposed to a total dose of 10, 20 and 40 Gy γ-radiation below the rib cage delivered as a single fraction of 2 Gy per day for 5, 10 or 20 days. Skin biopsies from both the curcumin treated or untreated irradiated groups were collected for the biochemical estimations at various post-irradiation times. The irradiation of animals caused a dose dependent decline in the glutathione concentration, glutathione peroxidase, and superoxide dismutase activities and increased the lipid peroxidation in the irradiated skin. Curcumin treatment before irradiation resulted in a significant rise in the glutathione concentration and activities of both the glutathione peroxidase and superoxide dismutase enzymes in mouse skin, whereas lipid peroxidation declined significantly. The present study indicates that curcumin treatment increased the antioxidant status of mouse exposed to different doses of fractionated γ-radiation. PMID:26785336

  8. Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation

    Directory of Open Access Journals (Sweden)

    Ganesh Chandra Jagetia

    2015-01-01

    Full Text Available Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain better therapeutic gains. Curcumin is an antioxidant and a free radical scavenging dietary supplement, commonly used as a flavoring agent in curries. Therefore, the effect of 100 mg/kg body weight curcumin was studied on the antioxidant status of mice skin exposed to a total dose of 10, 20 and 40 Gy γ-radiation below the rib cage delivered as a single fraction of 2 Gy per day for 5, 10 or 20 days. Skin biopsies from both the curcumin treated or untreated irradiated groups were collected for the biochemical estimations at various post-irradiation times. The irradiation of animals caused a dose dependent decline in the glutathione concentration, glutathione peroxidase, and superoxide dismutase activities and increased the lipid peroxidation in the irradiated skin. Curcumin treatment before irradiation resulted in a significant rise in the glutathione concentration and activities of both the glutathione peroxidase and superoxide dismutase enzymes in mouse skin, whereas lipid peroxidation declined significantly. The present study indicates that curcumin treatment increased the antioxidant status of mouse exposed to different doses of fractionated γ-radiation.

  9. Molecular mechanisms of plant response to ionising radiation. Exploration of the glucosinolate role in the anti-oxidative response

    International Nuclear Information System (INIS)

    Terrestrial organisms are exposed to low doses of ionising radiation from natural or anthropogenic sources. The major effects of the radiations are due to DNA deterioration and water radiolysis which generates an oxidative stress by free radical production. Plants constitute good models to study the effects of ionising radiations and the search of antioxidant molecules because of their important secondary metabolism. Thus this thesis, funded by the Brittany region, characterized the physiological and molecular response of the model plant Arabidopsis thaliana to low (10 Gy) and moderate (40 Gy) doses of ionising radiation, and was therefore interested in glucosinolates, characteristic compounds of the Brassicaceae family. The global proteomic and transcriptomic studies carried out on this model revealed (1) a common response for both doses dealing with the activation of DNA repair mechanisms, cell cycle regulation and protection of cellular structures; (2) an adjustment of the energetic metabolism and an activation of secondary compounds biosynthesis (i.e. glucosinolates and flavonoids) after the 10 Gy dose; (3) an induction of enzymatic control of ROS, the regulation of cellular components recycling and of programmed cell death after the 40 Gy dose. The potential anti-oxidative role of glucosinolates was then explored. The in vitro anti-oxidative power of some glucosinolates and their derivative products were demonstrated. Their modulating effects against irradiation-induced damages were then tested in vivo by simple experimental approaches. The importance of the glucosinolate level to give a positive or negative effect was demonstrated. (author)

  10. Chemical analysis, antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

    Institute of Scientific and Technical Information of China (English)

    Meriem El Kolli; Hocine Laouer; Hayet El Kolli; Salah Akkal; Farida Sahli

    2016-01-01

    Objective: To evaluate the essential oils (EO) composition, antimicrobial and antioxi-dant power of a local plant, Daucus gracilis (D. gracilis). Methods: The aerial parts of D. gracilis were subjected to hydro distillation by a Cle-venger apparatus type to obtain the EO which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry, and screened for antimicrobial activity against five bacteria and three fungi by agar diffusion method. The mechanism of action of the EO was determined on the susceptible strains by both of time kill assay and lysis experience. The minimal inhibitory concentrations were determined by agar macro-dilution and micro-dilution methods. Anti-oxidative properties of the EO were also studied by free diphenyl-2-picrylhydrazyl radical scavenging and reducing power techniques. Results: The EO yielded 0.68 (v/w). The chemical analysis presented two dominant constituents which were the elemicin (35.3%) and the geranyl acetate (26.8%). D. gracilis EO inhibited the growth of Bacillus cereus and Proteus mirabilis significantly with minimal inhibitory concentrations of 17.15 mg/mL by the agar dilution method and 57.05 mg/mL and 114.1 mg/mL, respectively by liquid micro-dilution. A remarkable decrease in a survival rate as well as in the absorbance in 260 nm was recorded, which suggested that the cytoplasm membrane was one of the targets of the EO. The EO showed, also, important anti-oxidative effects with an IC50 of 0.002 mg/mL and a dose-dependent reducing power. Conclusions: D. gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane. These activities could be exploited in the food industry for food preservation.

  11. Tert-butylhydroquinone attenuates the ethanol-induced apoptosis of and activates the Nrf2 antioxidant defense pathway in H9c2 cardiomyocytes.

    Science.gov (United States)

    Shi, Xiaojing; Li, Yang; Hu, Jun; Yu, Bo

    2016-07-01

    Tert-butylhydroquinone (tBHQ), an inducer of nuclear factor erythroid 2-related factor 2 (Nrf2), has been demonstrated to attenuate oxidative stress-induced injury and the apoptosis of human neural stem cells and other cell types. However, whether tBHQ is able to exert a protective effect against oxidative stress and the apoptosis of cardiomyocytes has not yet been determined. Thus, the objective of the present study was to determine whether tBHQ protects H9c2 cardiomyocytes against ethanol-induced apoptosis. For this purpose, four sets of experiments were performed under standard culture conditions as follows: i) untreated control cells; ii) cell treatment with 200 mM ethanol; iii) cell treatment with 5 µM tBHQ; and iv) cell pre-treatment with 5 µM tBHQ for 24 h, followed by medium change and co-culture with 200 mM ethanol containing 5 µM tBHQ for a further 24 h. The viability of the cardiomyocytes was evaluated by 3-(4,5-dimethylthiazol‑2-yl)‑2,5-diphenyltetrazolium bromide (MTT) assay. The levels of intracellular reactive oxygen species (ROS) and apoptosis were assessed by flow cytometry. Protein expression was measured by western blot analysis, and Nrf2 nuclear localization was observed by immunofluorescence. Exposure to ethanol led to a decrease in the protein expression of Nrf2 and its downstream antioxidant enzymes, accompanied by an increase in ROS generation and in the apoptosis of H9c2 cells. Pre-treatment with tBHQ significantly prevented the H9c2 cells from undergoing ethanol‑induced apoptosis. tBHQ also increased the expression of B-cell lymphoma-2 (Bcl-2), whereas Bcl-2-associated X protein (Bax) expression was decreased. tBHQ promoted Nrf2 nuclear localization and increased the expression of Nrf2, superoxide dismutase (SOD), catalase (CAT) and heme oxygenase-1 (HO-1), and simultaneously inhibited the ethanol‑induced overproduction of intracellular ROS. Therefore, tBHQ confers protection against the ethanol

  12. The Role of Oxidative Stress and Antioxidants in Diabetic Complications

    Directory of Open Access Journals (Sweden)

    Fatmah A Matough

    2012-02-01

    Full Text Available Diabetes is considered to be one of the most common chronic diseases worldwide. There is a growing scientific and public interest in connecting oxidative stress with a variety of pathological conditions including diabetes mellitus (DM as well as other human diseases. Previous experimental and clinical studies report that oxidative stress plays a major role in the pathogenesis and development of complications of both types of DM. However, the exact mechanism by which oxidative stress could contribute to and accelerate the development of complications in diabetic mellitus is only partly known and remains to be clarified. On the one hand, hyperglycemia induces free radicals; on the other hand, it impairs the endogenous antioxidant defense system in patients with diabetes. Endogenous antioxidant defense mechanisms include both enzymatic and non-enzymatic pathways. Their functions in human cells are to counterbalance toxic reactive oxygen species (ROS. Common antioxidants include the vitamins A, C, and E, glutathione (GSH, and the enzymes superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GPx, and glutathione reductase (GRx. This review describes the importance of endogenous antioxidant defense systems, their relationship to several pathophysiological processes and their possible therapeutic implications in vivo.

  13. β-Radiation Stress Responses on Growth and Antioxidative Defense System in Plants: A Study with Strontium-90 in Lemna minor.

    Science.gov (United States)

    Van Hoeck, Arne; Horemans, Nele; Van Hees, May; Nauts, Robin; Knapen, Dries; Vandenhove, Hildegarde; Blust, Ronny

    2015-01-01

    In the following study, dose dependent effects on growth and oxidative stress induced by β-radiation were examined to gain better insights in the mode of action of β-radiation induced stress in plant species. Radiostrontium (⁹⁰Sr) was used to test for β-radiation induced responses in the freshwater macrophyte Lemna minor. The accumulation pattern of 90Sr was examined for L. minor root and fronds separately over a seven-day time period and was subsequently used in a dynamic dosimetric model to calculate β-radiation dose rates. Exposing L. minor plants for seven days to a ⁹⁰Sr activity concentration of 25 up to 25,000 kBq·L⁻¹ resulted in a dose rate between 0.084 ± 0.004 and 97 ± 8 mGy·h⁻¹. After seven days of exposure, root fresh weight showed a dose dependent decrease starting from a dose rate of 9.4 ± 0.5 mGy·h⁻¹. Based on these data, an EDR10 value of 1.5 ± 0.4 mGy·h⁻¹ was estimated for root fresh weight and 52 ± 17 mGy·h⁻¹ for frond fresh weight. Different antioxidative enzymes and metabolites were further examined to analyze if β-radiation induces oxidative stress in L. minor. PMID:26198226

  14. β-Radiation Stress Responses on Growth and Antioxidative Defense System in Plants: A Study with Strontium-90 in Lemna minor

    Science.gov (United States)

    Van Hoeck, Arne; Horemans, Nele; Van Hees, May; Nauts, Robin; Knapen, Dries; Vandenhove, Hildegarde; Blust, Ronny

    2015-01-01

    In the following study, dose dependent effects on growth and oxidative stress induced by β-radiation were examined to gain better insights in the mode of action of β-radiation induced stress in plant species. Radiostrontium (90Sr) was used to test for β-radiation induced responses in the freshwater macrophyte Lemna minor. The accumulation pattern of 90Sr was examined for L. minor root and fronds separately over a seven-day time period and was subsequently used in a dynamic dosimetric model to calculate β-radiation dose rates. Exposing L. minor plants for seven days to a 90Sr activity concentration of 25 up to 25,000 kBq·L−1 resulted in a dose rate between 0.084 ± 0.004 and 97 ± 8 mGy·h−1. After seven days of exposure, root fresh weight showed a dose dependent decrease starting from a dose rate of 9.4 ± 0.5 mGy·h−1. Based on these data, an EDR10 value of 1.5 ± 0.4 mGy·h−1 was estimated for root fresh weight and 52 ± 17 mGy·h−1 for frond fresh weight. Different antioxidative enzymes and metabolites were further examined to analyze if β-radiation induces oxidative stress in L. minor. PMID:26198226

  15. β-Radiation Stress Responses on Growth and Antioxidative Defense System in Plants: A Study with Strontium-90 in Lemna minor

    Directory of Open Access Journals (Sweden)

    Arne Van Hoeck

    2015-07-01

    Full Text Available In the following study, dose dependent effects on growth and oxidative stress induced by β-radiation were examined to gain better insights in the mode of action of β-radiation induced stress in plant species. Radiostrontium (90Sr was used to test for β-radiation induced responses in the freshwater macrophyte Lemna minor. The accumulation pattern of 90Sr was examined for L. minor root and fronds separately over a seven-day time period and was subsequently used in a dynamic dosimetric model to calculate β-radiation dose rates. Exposing L. minor plants for seven days to a 90Sr activity concentration of 25 up to 25,000 kBq·L−1 resulted in a dose rate between 0.084 ± 0.004 and 97 ± 8 mGy·h−1. After seven days of exposure, root fresh weight showed a dose dependent decrease starting from a dose rate of 9.4 ± 0.5 mGy·h−1. Based on these data, an EDR10 value of 1.5 ± 0.4 mGy·h−1 was estimated for root fresh weight and 52 ± 17 mGy·h−1 for frond fresh weight. Different antioxidative enzymes and metabolites were further examined to analyze if β-radiation induces oxidative stress in L. minor.

  16. Mechanisms of Optimal Defense Patterns in Nicotiana attenuata: Flowering Attenuates Herbivory-elicited Ethylene and Jasmonate Signaling

    Institute of Scientific and Technical Information of China (English)

    Celia Diezel; Silke AIImann; lan T. Baldwin

    2011-01-01

    To defend themselves against herbivore attack,plants produce secondary metabolites,which are variously inducible and constitutively deployed,presumably to optimize their fitness benefits in light of their fitness costs.Three phytohormones,jasmonates (JA) and their active forms,the JA-isoleucine (JA-Ile) and ethylene (ET),are known to play central roles in the elicitation of induced defenses,but little is known about how this mediation changes over ontogeny.The Optimal Defense Theory (ODT) predicts changes in the costs and benefits of the different types of defenses and has been usefully extrapolated to their modes of deployment.Here we studied whether the herbivore-induced accumulation of JA,JA-lle and ET changed over ontogeny in Nicotiana attenuata,a native tobacco in which inducible defenses are particularly well studied.Herbivore-elicited ET production changed dramatically during six developmental stages,from rosette through flowering,decreasing with the elongation of the first corollas during flower development.This decrease was largely recovered within a day after flower removal by decapitation.A similar pattern was found for the herbivore-induced accumulation of JA and JA-IIe.These results are consistent with ODT predictions and suggest that the last steps in floral development control the inducibility of at least three plant hormones,optimizing defense-growth tradeoffs.

  17. Leaf Age-Dependent Photoprotective and Antioxidative Response Mechanisms to Paraquat-Induced Oxidative Stress in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Julietta Moustaka

    2015-06-01

    Full Text Available Exposure of Arabidopsis thaliana young and mature leaves to the herbicide paraquat (Pq resulted in a localized increase of hydrogen peroxide (H2O2 in the leaf veins and the neighboring mesophyll cells, but this increase was not similar in the two leaf types. Increased H2O2 production was concomitant with closed reaction centers (qP. Thirty min after Pq exposure despite the induction of the photoprotective mechanism of non-photochemical quenching (NPQ in mature leaves, H2O2 production was lower in young leaves mainly due to the higher increase activity of ascorbate peroxidase (APX. Later, 60 min after Pq exposure, the total antioxidant capacity of young leaves was not sufficient to scavenge the excess reactive oxygen species (ROS that were formed, and thus, a higher H2O2 accumulation in young leaves occurred. The energy allocation of absorbed light in photosystem II (PSII suggests the existence of a differential photoprotective regulatory mechanism in the two leaf types to the time-course Pq exposure accompanied by differential antioxidant protection mechanisms. It is concluded that tolerance to Pq-induced oxidative stress is related to the redox state of quinone A (QA.

  18. Antioxidant properties of proanthocyanidins of Uncaria tomentosa bark decoction: a mechanism for anti-inflammatory activity

    OpenAIRE

    Gonçalves, Cristina; Dinis, Teresa; Batista, Maria Teresa

    2005-01-01

    Decoctions prepared from the bark of Uncaria tomentosa (cat's claw) are widely used in the traditional Peruvian medicine for the treatment of several diseases, in particular as a potent anti-inflammatory agent. Therefore, the main purpose of this study was to determine if the well-known anti-inflammatory activity of cat's claw decoction was related with its reactivity with the oxidant species generated in the inflammatory process and to establish a relationship between such antioxidant abilit...

  19. Antioxidant mechanisms of iso-6-cassine in suppressing seizures induced by pilocarpine

    Directory of Open Access Journals (Sweden)

    Rivelilson Mendes de Freitas

    2011-06-01

    Full Text Available The aim of this study was to evaluate the in vitro antioxidant effects of 12-[(2R,5R,6R-5-hydroxy-6-methylpiperidin-2-yl]dodecan-2-one (iso-6-cassine; ISO and the anticonvulsant effects of ISO on pilocarpine-induced seizures in rats. Wistar rats were treated with 0.9% saline (i.p., control group, pilocarpine (400 mg/kg, i.p., pilocarpine group, and the association of ISO (1.0 mg/kg, i.p. plus pilocarpine (400 mg/kg, i.p., 30 min after administration of ISO (ISO plus pilocarpine group. After the treatments all groups were observed for 1h. The antioxidant effect of ISO on the pilocarpine model was assessed by determining the activity of glutathione peroxidase (GPx, glutathione-S-transferase (GST and catalase (CAT as well as the levels of reactive species (RS and lipid peroxidation (LP. In vitro, ISO (5 μM reduced RS and LP. ISO (1.0 mg/kg and abolished seizures and death induced by pilocarpine in rats. ISO protected against the increase in the RS and LP levels, GST activity as well as the inhibition of GPx activity caused by pilocarpine. In addition, ISO increased the catalase activity in hippocampus of seized rats. In conclusion, the dta suggest that ISO can present anticonvulsant and antioxidant properties in the pilocarpine model of seizures in rats.

  20. The triterpene glycosides of Holothuria forskali: usefulness and efficiency as a chemical defense mechanism against predatory fish

    OpenAIRE

    Van Dyck, S.; Caulier, G.; Todesco, M.; Gerbaux, P.; Fournier, I.; Wisztorski, M.; Flammang, P

    2011-01-01

    More than 100 triterpene glycosides (saponins) have been characterized in holothuroids in the past several decades. In particular, Holothuria forskali contains 26 saponins in its Cuvierian tubules and 12 in its body wall. This high diversity could be linked to a chemical defense mechanism, the most commonly accepted biological role for these secondary metabolites. We performed an integrated study of the body-wall saponins of H. forskali. The saponins are mainly localized in the epidermis and ...

  1. Natural Antioxidants, Lipid Profile, Lipid Peroxidation, Antioxidant Enzymes of Different Vegetable Oils

    Directory of Open Access Journals (Sweden)

    Eqbal M.A. Dauqan

    2011-08-01

    Full Text Available Antioxidant plays a very important role in the body defense system against Reactive Oxygen Species (ROS. The free radicals also play an important role in combustion, atmospheric chemistry, biochemistry and biotechnology including human physiology. Fats and oils are energy sources that are composed mostly of triacylglycerols. Lipid ptofile are risk indicators of coronary heart disease. Various types of lipoproteins exist, but the two most abundant are Low-density Lipoprotein (LDL and High-density Lipoprotein (HDL. Lipid peroxidation is the introduction of a functional group containing two catenated oxygyen atomsinto unsturated fatty acids in a free radical reaction. Life in oxygen has led to the evolution of biochemical adaptations that exploit the reactivity of Active Oxygen Species (AOS. Antioxidant enzymes are an important protective mechanism ROS. This paper highlight the functions of antioxidants in the blood and selected organs associated with health.

  2. Deltamethrin-induced oxidative stress and biochemical changes in tissues and blood of catfish (Clarias gariepinus: antioxidant defense and role of alpha-tocopherol

    Directory of Open Access Journals (Sweden)

    Amin Kamal A

    2012-04-01

    Full Text Available Abstract Background The pyrethroid class of insecticides, including deltamethrin, is being used as substitutes for organochlorines and organophosphates in pest-control programs because of their low environmental persistence and toxicity. This study was aimed to investigate the impact of commonly used pesticides (deltamethrin on the blood and tissue oxidative stress level in catfish (Clarias gariepinus; in addition to the protective effect of α-tocopherol on deltamethrin induced oxidative stress. Catfish were divided into three groups, 1st control group include 20 fish divided into two tanks each one contain 10 fish, 2nd deltamethrin group, where Fish exposed to deltamethrin in a concentration (0.75 μg/l and 3rd Vitamin E group, Fish exposed to deltamethrin and vitamin E at a dose of 12 μg/l for successive 4 days. Serum, liver, kidney and Gills were collected for biochemical assays. Tissue oxidative stress biomarkers malondialdhyde (MDA and catalase activity in liver, kidney and gills tissues, serum liver enzymes (ALT and AST, serum albumin, total protein, urea and creatinine were analysed. Results Our results showed that 48 h. exposure to 0.75 μg/l deltamethrin significantly (p  Conclusions It could be concluded that deltamethrin is highly toxic to catfish even in very low concentration (0.75 μg/l. Moreover the effect of deltamethrin was pronounced in the liver of catfish in comparison with kidneys and gills. Moreover fish antioxidants and oxidative stress could be used as biomarkers for aquatic pollution, thus helping in the diagnosis of pollution. Adminstration of 12 μg/l α-tocopherol restored the quantified tissue and serum parameters, so supplementation of α-tocopherol consider an effective way to counter the toxicity of deltamethrin in the catfish.

  3. Evaluation of Polyphenol Content and Antioxidant Properties of some Fruit Seeds

    Directory of Open Access Journals (Sweden)

    Liana Claudia Salanţă

    2015-11-01

    Full Text Available A diversity of secondary plant metabolite with an antioxidant character are present in the vegetal extracts, such as: tocopherols, carotenoids, phenolic acids, flavonoids, etc. These compounds intervene in the cellular defense mechanisms against the free radicals and oxidative stress, as they possess anticancer and anti mutation effect. The aim of this work was to study the antioxidant capacity and polyphenol content of methanolic extracts obtained from seeds of fruits: Vitis vinifera, Malus domestica and Citrullus lanatus. Grape seeds have a high content of antioxidants and polyphenols compounds, due to this, it is recommended their used in obtaining functional food with benefit on the human body.

  4. Dl-3-n-butylphthalide-induced upregulation of antioxidant defense is involved in the enhancement of cross talk between CREB and Nrf2 in an Alzheimer's disease mouse model.

    Science.gov (United States)

    Wang, Chun-Yan; Wang, Zhan-You; Xie, Jing-Wei; Wang, Tao; Wang, Xu; Xu, Ye; Cai, Jian-Hui

    2016-02-01

    Synapse impairment in the Alzheimer's disease (AD) brain is an early event leading to cognitive dysfunction. Most oxidative stress localizes to the synapse, and synapse loss is the basis of cognitive decline in AD. Dl-3-n-butylphthalide (Dl-NBP), a small molecule compound has been shown to ameliorate oxidative stress. We evaluated the effects of a 5-month oral delivery with Dl-NBP on oxidative stress and cognitive function in APP/PS1 transgenic mice. Dl-NBP treatment reduced oxidative stress in the APP/PS1 mouse brain and alleviated learning and memory deficits. Dl-NBP supplementation meliorated synaptic plasticity, diminished soluble amyloid beta and amyloid beta oligomer in the APP/PS1 mouse brain. Dl-NBP administration caused an increase of cyclic adenosine monophosphate-response element binding protein (CREB)-binding protein (CBP)-associated Ser133-phosphorylated CREB (p-CREB) protein. Chromatin immunoprecipitation analysis revealed that Dl-NBP increased the recruitment of CBP to the promoters of best-characterized genes downstream of nuclear factor erythroid 2-related factor 2, nicotinamide adenine dinucleotide phosphate (NADPH) quinone oxidoreductase 1, and γ-glutamylcysteine synthetase modifier subunit. We demonstrate that the Dl-NBP-triggered upregulation of antioxidant defenses is involved in the enhancement of cross talk between CREB and nuclear factor erythroid 2-related factor 2 via CBP. Our results suggest that Dl-NBP may be a useful agent for the treatment of AD. PMID:26827641

  5. Auxins in defense strategies

    OpenAIRE

    Čarná, M. (Mária); Repka, V.; Skůpa, P. (Petr); Šturdík, E.

    2014-01-01

    Plant hormones operate in a very complex network where they regulate and control different vital mechanisms. They coordinate growth, development and defense via signaling involving different interactions of molecules. Activation of molecules responsible for regulation of plant immunity is mainly provided by salicylic and jasmonic acid signaling pathways. Similar to the signaling of these defense-associated plant hormones, auxin can also affect resistance to different pathogen groups and disea...

  6. PHENOMENON OF PSYCHOLOGICAL DEFENSE

    OpenAIRE

    Elena T. Sokolova

    2011-01-01

    The author discusses the controversial issues of formation and functioning of psychological defense mechanisms in ontogenesis and in personality disorders as they are represented in classical and contemporary psychoanalysis, in cognitivism and communication theory. The paper emphasizes the role of cognitive organization (style), sign-symbolic mediation, representative system of object relations and attachments in individual typological variability of the level organization of defense mechanis...

  7. Response of Tomato Seedlings Heme Oxygenase-1 to Heat Shock Stress and Its Role in Antioxidative Defense%番茄幼苗血红素加氧酶-1对热激的响应及其抗氧化防护作用

    Institute of Scientific and Technical Information of China (English)

    陈笑玥; 张毅华; 张耀文; 沈文飚

    2015-01-01

    植物受到高温胁迫以后,会通过诱导热激响应(HSR)包括诱导热激蛋白(HSP)和抗氧化酶编码基因的表达来缓解胁迫造成的伤害,但是不清楚其具体的诱导机理。本实验以番茄(Solanum lycopersicum)‘苏红2003’幼苗为材料,研究了血红素加氧酶-1(HO-1, EC 1.14.99.3)对热激的响应及其抗氧化防护作用。结果表明,45℃热激3 h内不但能以时间依赖性的方式诱导番茄幼苗脂质过氧化和抑制茎生长,还能上调HO的活性和HO-1蛋白水平;进一步加入HO-1的活性抑制剂锌原卟啉IX (ZnPPIX)则加剧热激诱导的氧化胁迫;此外, ZnPPIX还能部分阻断热激诱导的HO活性上调,同时热激诱导的两种抗氧化酶——过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性明显受到抑制,编码热激蛋白的SlHSP70和SlHSP20基因表达也被显著削弱或延迟,但SlHSP17.7和SlHSP101的转录本则不受ZnPPIX的影响。以上的研究结果表明,番茄HO-1能够部分参与HSP的诱导和抗氧化防护。%Upon heat shock stress, plants normally induce heat shock response (HSR). For example, the induc-tion of genes encoding heat shock proteins (HSP) and antioxidant enzymes could protect plants against damag-es caused by heat stress. However, the detailed inducible mechanism is still elusive. In this study, the response of tomato heme oxygenase-1 (HO-1, EC 1.14.99.3) to heat shock stress and its role in antioxidative defense were investigated. Our results show that heat shock treatment is not only able to time-dependently induce lipid peroxidation and stem elongation inhibition in tomato (Solanum lycopersicum) seedlings, but also increase HO activity and HO-1 protein level. Furthermore, ZnPPIX, the potent inhibitor of HO-1, could aggravate the heat-induced oxidative damage. Meanwhile, the increased HO activity triggered by heat shock was partly blocked by ZnPPIX. Activities of the two antioxidant enzymes, including catalase (CAT) and

  8. Protein kinase Cδ mediates trimethyltin-induced neurotoxicity in mice in vivo via inhibition of glutathione defense mechanism.

    Science.gov (United States)

    Shin, Eun-Joo; Nam, Yunsung; Tu, Thu-Hien Thi; Lim, Yong Kwang; Wie, Myung-Bok; Kim, Dae-Joong; Jeong, Ji Hoon; Kim, Hyoung-Chun

    2016-04-01

    We investigated whether protein kinase C (PKC) is involved in trimethyltin (TMT)-induced neurotoxicity. TMT treatment (2.8 mg/kg, i.p.) significantly increased PKCδ expression out of PKC isozymes (i.e., α, βI, βII, δ, and ς) in the hippocampus of wild-type (WT) mice. Consistently, treatment with TMT resulted in significant increases in cleaved PKCδ expression. Genetic or pharmacological inhibition (PKCδ knockout or rottlerin) was less susceptible to TMT-induced seizures than WT mice. TMT treatment increased glutathione oxidation, lipid peroxidation, protein oxidation, and levels of reactive oxygen species. These effects were more pronounced in the WT mice than in PKCδ knockout mice. In addition, the ability of TMT to induce nuclear translocation of Nrf2, Nrf2 DNA-binding activity, and upregulation of γ-glutamylcysteine ligase was significantly increased in the PKCδ knockout mice and rottlerin (10 or 20 mg/kg, p.o. × 6)-treated WT mice. Furthermore, neuronal degeneration (as shown by nuclear chromatin clumping and TUNEL staining) in WT mice was most pronounced 2 days after TMT. At the same time, TMT-induced inhibition of phosphoinositol 3-kinase (PI3K)/Akt signaling was evident, thereby decreasing phospho-Bad, expression of Bcl-xL and Bcl-2, and the interaction between phospho-Bad and 14-3-3 protein, and increasing Bax expression and caspase-3 cleavage were observed. Rottlerin or PKCδ knockout significantly protected these changes in anti- and pro-apoptotic factors. Importantly, treatment of the PI3K inhibitor LY294002 (0.8 or 1.6 µg, i.c.v.) 4 h before TMT counteracted protective effects (i.e., Nrf-2-dependent glutathione induction and pro-survival phenomenon) of rottlerin. Therefore, our results suggest that down-regulation of PKCδ and up-regulations of Nrf2-dependent glutathione defense mechanism and PI3K/Akt signaling are critical for attenuating TMT neurotoxicity. PMID:25895139

  9. Chronic exposure to MDMA (ecstasyinduces DNA damage, impairs functional antioxidant cellular defenses, enhances the lipid peroxidation process and alters testes histopathology in male rat

    Directory of Open Access Journals (Sweden)

    Nadia Gamal Zaki, ** Laila Abdel Kawy

    2013-04-01

    decreased testosterone secretion. The results suggested that graded doses of ecstasy elicit depletion of antioxidant defence system and induce oxidative stress in testis of rats. In conclusion: the adverse effect of ecstasy on male reproduction may be due to induction of oxidative stress

  10. Protective effect of supercritical fluid rosemary extract, , on antioxidants of major organs of aged rats

    OpenAIRE

    Posadas, S.J.; Caz, V.; Largo, C. (Cristina); De La Gándara, B.; Matallanas, B.; G. Reglero; Miguel, E.

    2009-01-01

    International audience Rosemary leaves, “”, possess a variety of antioxidant, anti-tumoral and anti-inflammatory bioactivities. We hypothesized that rosemary extract could enhance antioxidant defenses and improve antioxidant status in aged rats.

  11. Oxidative Response and Antioxidative Mechanism in Germinating Soybean Seeds Exposed to Cadmium

    OpenAIRE

    Shiyong Yang; Jianchun Xie; Quanfa Li

    2012-01-01

    Seeds of soybean (Glycine max L.) exposed to 50 mg/L (Cd50), 100 mg/L (Cd100) and 200 mg/L (Cd200) cadmium solution for 24, 48, 72 and 96 h were examined with reference to Cd accumulation, oxidative stress and antioxidative responses. Soybean seeds accumulated Cd in an exposure time-and dosage-dependent manner. FRAP (ferric reducing ability of plasma) concentration, GSH/hGSH content, and GST activity showed a pronounced exposure time-dependent respons...

  12. Chemistry and pharmacological properties of some natural and synthetic antioxidants for heavy metal toxicity.

    Science.gov (United States)

    Flora, S J S; Shrivastava, Rupal; Mittal, Megha

    2013-01-01

    Heavy metals are known to cause oxidative deterioration of bio-molecules by initiating free radical mediated chain reaction resulting in lipid per-oxidation, protein oxidation and oxidation of nucleic acid like DNA and RNA. The development of effective dual functioning antioxidants, possessing both metal-chelating and free radical-scavenging properties should bring into play. Administration of natural and synthetic antioxidants like, quercetin, catechin, taurine, captopril, gallic acid, melatonin, N-acetyl cysteine, α- lipoic acid and others have been recognized in the disease prevention and clinical recovery against heavy metal intoxication. These antioxidants affect biological systems not only through direct quenching of free radicals but also via chelation of toxic metal(s). These antioxidants also, have the capacity to enhance cellular antioxidant defense mechanism by regenerating endogenous antioxidants, such as glutathione and vitamin C and E. They also influence cellular signaling and trigger redox sensitive regulatory pathways. The reactivity of antioxidants in protecting against heavy metal induced oxidative stress depends upon their structural properties, their partitioning abilities between hydrophilic and lipophilic environment and their hydrogen donation antioxidant properties. Herein, we review the structural, biochemical and pharmacological properties of selected antioxidants with particular reference to their ability to (i) chelate heavy metals from its complex (ii) ameliorate free radical (iii) terminate heavy metal induced free radical chain reaction (iv) regenerate endogenous antioxidants and, (v) excretion of metal without its redistribution. PMID:24206124

  13. Methionine residues as endogenous antioxidants in proteins

    OpenAIRE

    Levine, Rodney L.; Mosoni, Laurent; Berlett, Barbara S.; Stadtman, Earl R.

    1996-01-01

    Cysteine and methionine are the two sulfur-containing residues normally found in proteins. Cysteine residues function in the catalytic cycle of many enzymes, and they can form disulfide bonds that contribute to protein structure. In contrast, the specific functions of methionine residues are not known. We propose that methionine residues constitute an important antioxidant defense mechanism. A variety of oxidants react readily with methionine to form methionine sulfoxi...

  14. Nutraceutical Antioxidants as Novel Neuroprotective Agents

    Directory of Open Access Journals (Sweden)

    Daniel A. Linseman

    2010-11-01

    Full Text Available A variety of antioxidant compounds derived from natural products (nutraceuticals have demonstrated neuroprotective activity in either in vitro or in vivo models of neuronal cell death or neurodegeneration, respectively. These natural antioxidants fall into several distinct groups based on their chemical structures: (1 flavonoid polyphenols like epigallocatechin 3-gallate (EGCG from green tea and quercetin from apples; (2 non-flavonoid polyphenols such as curcumin from tumeric and resveratrol from grapes; (3 phenolic acids or phenolic diterpenes such as rosmarinic acid or carnosic acid, respectively, both from rosemary; and (4 organosulfur compounds including the isothiocyanate, L-sulforaphane, from broccoli and the thiosulfonate allicin, from garlic. All of these compounds are generally considered to be antioxidants. They may be classified this way either because they directly scavenge free radicals or they indirectly increase endogenous cellular antioxidant defenses, for example, via activation of the nuclear factor erythroid-derived 2-related factor 2 (Nrf2 transcription factor pathway. Alternative mechanisms of action have also been suggested for the neuroprotective effects of these compounds such as modulation of signal transduction cascades or effects on gene expression. Here, we review the literature pertaining to these various classes of nutraceutical antioxidants and discuss their potential therapeutic value in neurodegenerative diseases.

  15. Rice bran oil prevents neuroleptic-induced extrapyramidal symptoms in rats: Possible antioxidant mechanisms

    Directory of Open Access Journals (Sweden)

    Noreen Samad

    2015-09-01

    Full Text Available Tardive dyskinesia (TD is one of the serious side effects of long-term antipsychotic treatment. Chronic treatment with neuroleptic leads to the development of abnormal oral movements called vacuous chewing movements (VCMs. The oxidative stress hypothesis of TD is one of the possible pathophysiologic models for TD. Preclinical and clinical studies of this hypothesis indicate that neurotoxic free radical production is likely to be a consequence of antipsychotic medication and is related to occurrence of TD. Oxidative stress is implicated in the pathophysiology of TD. Rats chronically treated with haloperidol orally at a dose of 0.2 mg/kg/day for a period of 5 weeks developed VCMs, which increased in a time-dependent manner as the treatment continued for 5 weeks. Motor coordination impairment started after the 1st week and was maximally impaired after 3 weeks and gradually returned to the 1st week value. Motor activity in an open field or home cage (activity box not altered. Administration of rice bran oil (antioxidant by oral tubes at a dose of 0.4 mL/day prevented the induction of haloperidol-elicited VCMs as well impairment of motor coordination. The results are discussed in the context of a protective role of antioxidant of rice bran oil in the prevention of haloperidol-induced extrapyramidal symptoms.

  16. Electrochemical study of the increased antioxidant capacity of flavonoids through complexation with iron(II) ions

    International Nuclear Information System (INIS)

    Highlights: • Metal-Flavonoid complexes exhibit greater antioxidant capacity than the free flavonoid;. • Voltammetric profile is an additional information for determining antioxidant capacity;. • Pyrogallol group is a stronger complex-forming group than the catechol;. • Morin, quercetin and fisetin increased their antioxidant capacity in 15%, 32% and 28%, respectively. - Abstract: Flavonoids are polyphenolic compounds that act as natural antioxidants in the human body through various mechanisms, with an emphasis on suppressing reactive oxygen species (ROS) formation by inhibiting enzymes, the direct capture of ROS, and the regulation/protection of antioxidant defenses. Additionally, flavonoids can coordinate with transition metals to catalyze electron transport and promote free radical capture. Recently, metal ion chelation mechanisms have generated considerable interest, as experimental data show that flavonoids in metal complexes exhibit greater antioxidant activity than free flavonoids. However, few studies have correlated the complexing properties of flavonoids with their antioxidant capacity. Thus, the aim of this study was to use the CRAC (Ceric Reducing Antioxidant Capacity) electrochemical assay to measure the antioxidant capacity of five free flavonoids and Fe2+-flavonoid complexes. In addition, the interactions between the flavonoids and Fe2+ were analyzed based on the oxidation peaks formed in their cyclic voltammograms

  17. Arsenic-Mediated Activation of the Nrf2-Keap1 Antioxidant Pathway

    OpenAIRE

    Lau, Alexandria; Whitman, Samantha A; Jaramillo, Melba C.; Zhang, Donna D.

    2012-01-01

    Arsenic is present in the environment and has become a worldwide health concern due to its toxicity and carcinogenicity. However, the specific mechanism(s) by which arsenic elicits its toxic effects has yet to be fully elucidated. The transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) has been recognized as the master regulator of a cellular defense mechanism against toxic insults. This review highlights studies demonstrating that arsenic activates the Nrf2-Keap1 antioxid...

  18. IN VITRO ANTIOXIDANT ACTIVITY OF IPOEMA BILOBA

    Directory of Open Access Journals (Sweden)

    Priti Tagde

    2012-01-01

    Full Text Available Biomolecules can be oxidized by free radicals. This oxidative damage has an important etiological role in aging and the development of diseases like cancer, atherosclerosis, and other inflammatory disorders. Synthetic antioxidants, like butylated hydroxyanisole, are good free radical scavengers; however, the synthetic antioxidants can be carcinogenic. Therefore, there is an increasing interest in searching for antioxidants of natural origin.   Antioxidants with different chemical properties may recharge each other in an antioxidant network. The total antioxidant content of dietary plants may therefore be a useful tool for testing the 'antioxidant network' hypothesis. Several berries, fruits, nuts, seeds, vegetables, drinks and spices have been found to be high in total antioxidants. Initial studies in animals and humans are supportive as to the beneficial effects of dietary plants rich in total antioxidants. Additionally, antioxidants and other plant compounds may also improve the endogenous antioxidant defense through induction of antioxidant and phase 2 enzymes.1,2 Dietary plants rich in such compounds include broccoli, brussel sprouts, cabbage, kale, cauliflower, carrots, onions, tomatoes, spinach and garlic , antioxidants and other plant compounds may also improve the endogenous antioxidant defense through induction of antioxidant and phase 2 enzymes.

  19. Understanding salt tolerance mechanisms in wheat genotypes by exploring antioxidant enzymes

    DEFF Research Database (Denmark)

    Amjad, M.; Akhtar, J.; Haq, M.A.;

    2014-01-01

    The activities of antioxidant enzymes were analyzed in six wheat genotypes under different concentrations of NaCl (0, 100 and 200 mM). Plants were harvested after either 15 or 30 days of salt stress. The most salt tolerant genotype (SARC-1) maintained lower Na+ and higher relative growth rate (RGR......), shoot fresh weight (SFW), shoot-root ratio, and K+:Na+ ratio, compared to the most salt sensitive genotypes (S-9189 and S-9476). Superoxide dismutase (SOD) and catalase (CAT) increased significantly in SARC-1 and SARC-2 with increasing salt stress, while there was no difference in S-9189 and S- 9476....... Additionally, glutathione reductase (GR) activity was decreased in salt sensitive (S-9189 and S-9476) than salt tolerant (SARC-1) genotypes. Under salt stress conditions a negative relationship between SOD and leaf Na+, and a positive between SOD and shoot fresh weight (SFW), were observed. The higher...

  20. The mechanism of patulin's cytotoxicity and the antioxidant activity of indole tetramic acids

    Energy Technology Data Exchange (ETDEWEB)

    Riley, R.T.; Showker, J.L. (Toxicology and Mycotoxins Research Unit, U.S. Department of Agriculture/Agricultural Research Service, Athens, GA (USA))

    1991-06-01

    In LLC-PK1 cells exposed to patulin (50 microM), lipid peroxidation, abrupt calcium influx, extensive blebbing, and total LDH release appeared to be serially connected events with each representing a step in the loss of structural integrity of the plasma membrane. The aforementioned patulin-induced events were prevented by concurrent incubation with butylated hydroxytoluene, deferoxamine, and cyclopiazonic acid, a fungal metabolite. Patulin also caused depletion of nonprotein sulfhydryls, increased 86Rb+ efflux, dome collapse, and eventually the loss of cell viability. These events were not prevented by antioxidants, results consistent with the hypothesis that they were also serially connected but occurring parallel to those previously mentioned. The earliest events observed in patulin-treated cells were the decrease in nonprotein sulfhydryls and increase in 86Rb+ efflux (5 min) which occurred before statistically significant alterations in protein-bound sulfhydryls. The increased potassium efflux (86Rb+ efflux) occurred via a pathway distinct from BaCl2, quinine, or tetraethylammonium sensitive potassium channels. This is the first published report of the antioxidant activity of indole tetramic acids (cyclopiazonic acid and cyclopiazonic acid imine). The protective effect of tetramic acids in LLC-PK1 cells was restricted to indole tetramic acids, and their prevention of lipid peroxidation did not involve iron chelation. The results of this study demonstrate that cyclopiazonic acid is a potent inhibitor of azide-insensitive, ATP-dependent, a23187-sensitive calcium uptake by the lysate of LLC-PK1 cells. This result is consistent with the hypothesis that the endoplasmic reticulum calcium transport ATPase is a sensitive target for cyclopiazonic acid in LLC-PK1 cells.

  1. Cardiovascular diseases: oxidative damage and antioxidant protection.

    Science.gov (United States)

    Zhang, P-Y; Xu, X; Li, X-C

    2014-10-01

    Atherosclerosis, the hardening of arteries under oxidative stress is related to oxidative changes of low density lipoproteins (LDL). The antioxidants prevent the formation of oxidized LDL during atherogenesis. Perhaps more than one mechanism is involved in the atherosclerosis disease where LDL is oxidized in all the cells of arterial wall during the development of this disease. The oxidation of LDL produces lipid peroxidation products such as isoprostans from arachidonic, eicosapentaenoic and docosahexaenoic acids, oxysterols from cholesterol, hydroxyl fatty acids, lipid peroxides and aldehydes. The lipid peroxidation bioassay can serve as a marker for the risk of cardiovascular. An in vivo test of levels of oxidative lipid damage is an early prediction of development of cardiovascular disease (CVD). Serum paraoxonase (PON) activity is correlated to severity of the coronary artery disease. The antioxidants level in the serum and serum paraoxonase activity provides information for the risk of CVD. The antioxidant enzyme superoxide dismutase is responsible for dismutation of superoxide, a free radical chain initiator. The subcellular changes in the equilibrium in favor of free radicals can cause increase in the oxidative stress which leads to cardiomyopathy, heart attack or cardiac dysfunction. The oxidative damage and defense of heart disease has been reported where dietary antioxidants protect the free radical damage to DNA, proteins and lipids. The ascorbic acid, vitamin C is an effective antioxidant and high vitamin E intake can reduce the risk of coronary heart disease (CHD) by inhibition of atherogenic forms of oxidized LDL. The vitamin A and beta-carotene protect lipid peroxidation and provitamin-A activity. It has been recently suggested that the protection of oxidative damage and related CVD is best served by antioxidants found in the fruits and vegetables. The oxidative damage and antioxidant protection of CVD have been described here. PMID:25392110

  2. Analysis of the Molecular Dialogue Between Gray Mold (Botrytis cinerea) and Grapevine (Vitis vinifera) Reveals a Clear Shift in Defense Mechanisms During Berry Ripening.

    Science.gov (United States)

    Kelloniemi, Jani; Trouvelot, Sophie; Héloir, Marie-Claire; Simon, Adeline; Dalmais, Bérengère; Frettinger, Patrick; Cimerman, Agnès; Fermaud, Marc; Roudet, Jean; Baulande, Sylvain; Bruel, Christophe; Choquer, Mathias; Couvelard, Linhdavanh; Duthieuw, Mathilde; Ferrarini, Alberto; Flors, Victor; Le Pêcheur, Pascal; Loisel, Elise; Morgant, Guillaume; Poussereau, Nathalie; Pradier, Jean-Marc; Rascle, Christine; Trdá, Lucie; Poinssot, Benoit; Viaud, Muriel

    2015-11-01

    Mature grapevine berries at the harvesting stage (MB) are very susceptible to the gray mold fungus Botrytis cinerea, while veraison berries (VB) are not. We conducted simultaneous microscopic and transcriptomic analyses of the pathogen and the host to investigate the infection process developed by B. cinerea on MB versus VB, and the plant defense mechanisms deployed to stop the fungus spreading. On the pathogen side, our genome-wide transcriptomic data revealed that B. cinerea genes upregulated during infection of MB are enriched in functional categories related to necrotrophy, such as degradation of the plant cell wall, proteolysis, membrane transport, reactive oxygen species (ROS) generation, and detoxification. Quantitative-polymerase chain reaction on a set of representative genes related to virulence and microscopic observations further demonstrated that the infection is also initiated on VB but is stopped at the penetration stage. On the plant side, genome-wide transcriptomic analysis and metabolic data revealed a defense pathway switch during berry ripening. In response to B. cinerea inoculation, VB activated a burst of ROS, the salicylate-dependent defense pathway, the synthesis of the resveratrol phytoalexin, and cell-wall strengthening. On the contrary, in infected MB, the jasmonate-dependent pathway was activated, which did not stop the fungal necrotrophic process. PMID:26267356

  3. Selection on defensive traits in a sterile caste - caste evolution: a mechanism to overcome life-history trade-offs?

    Science.gov (United States)

    Roux, Estelle A; Roux, Maurice; Korb, Judith

    2009-01-01

    During development and evolution individuals generally face a trade-off between the development of weapons and gonads. In termites, characterized by reproductive division of labor, a caste evolved-the soldiers-which is completely sterile and which might be released from developmental trade-offs between weapons and testes. These soldiers are exclusively dedicated to defense. First, we investigated whether defensive traits are under selection in sterile termite soldiers using allometric analyses. In soldiers of the genus Cryptotermes phragmotic traits such as a sculptured and foreshortened head evolve rapidly but were also lost twice. Second, we compared the scaling relationships of these weapons with those in solitary insects facing a trade-off between weapons and gonads. Defensive traits consistently had lower slopes than nondefensive traits which supports the existence of stabilizing selection on soldier phragmotic traits in order to plug galleries. Moreover, soldier head widths were colony specific and correlated with the minimum gallery diameter of a colony. This can proximately be explained by soldiers developing from different instars. The scaling relationships of these termite soldiers contrast strikingly with those of weapons of solitary insects, which are generally exaggerated (i.e., overscaling) male traits. These differences may provide important insights into trait evolution. Trade-offs constraining the development of individuals may have been uncoupled in termites by evolving different castes, each specialized for one function. When individuals in social insect are "released" from developmental constraints through the evolution of castes, this certainly contributed to the ecological and evolutionary success of social insects. PMID:19196335

  4. Mejora de defensas antioxidantes mediante ejercicio aeróbico en mujeres con síndrome metabólico Aerobic training improves antioxidant defense system in women with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Manuel Rosety-Rodríguez

    2012-02-01

    Full Text Available En la actualidad se acepta que el daño oxidativo juega un papel esencial en la patogénesis del síndrome metabólico. Estudios recientes proponen al daño oxidativo como diana terapéutica frente al síndrome metabólico. Precisamente nuestro objetivo fue mejorar el estatus total antioxidante (TAS de mujeres con síndrome metabólico mediante ejercicio aeróbico. Participaron voluntariamente 100 mujeres con síndrome metabólico de acuerdo con los criterios del National Cholesterol Educational Program (Adult-Treatment-Panel-III distribuidas aleatoriamente en grupo experimental (n = 60 y control (n = 40. El grupo experimental desarrolló un programa de entrenamiento aeróbico sobre tapiz rodante de intensidad ligera/moderada de 12 semanas (5 sesiones/semana. La determinación del TAS plasmático se realizó mediante espectrofotometría utilizando kits comercializados por Randox Lab. Este protocolo fue aprobado por un Comité de Etica Institucional. Tras completar el programa de entrenamiento se incrementó significativamente el TAS (0.79 ± 0.05 vs.1.01 ± 0.03 mmol/l; p = 0.027. No hubo cambios en grupo control. El ejercicio aeróbico de intensidad ligera/moderada aumenta las defensas antioxidantes en mujeres con síndrome metabólico. Son necesarios futuros estudios longitudinales para conocer su impacto en la evolución clínica.A 12-week training protocol increased antioxidant defense system in young adult women with metabolic syndrome. It is generally accepted that oxidative stress is implicated in the pathogenesis of metabolic syndrome. Furthermore, recent studies have reported that stress may be acting as a therapeutic target in metabolic syndrome. Consequently, this study was designed to explore whether aerobic training may increase plasmatic total antioxidant status in women with metabolic syndrome. A total of 100 young adult women with metabolic syndrome according to the criteria reported by the National Cholesterol Education Program

  5. 18 W/m2 Mockup for Defense High-Level Waste (Rooms A): In situ data report: Volume 1---Mechanical response gages (February 1985--June 1990)

    International Nuclear Information System (INIS)

    Data are presented from the 18 W/m2 Mockup for Defense High-Level Waste, a very large scale in situ test fielded underground at the Waste Isolation Pilot Plant (WIPP). These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. The results in this report give measured data from the mechanical response gages, i.e., room closure gages, extensometers, and stress meters emplaced in the test. Construction of the test began in June 1984; gage data in this report cover the complete test duration, that is, to June 1990

  6. Formaldehyde induces lung inflammation by an oxidant and antioxidant enzymes mediated mechanism in the lung tissue.

    Science.gov (United States)

    Lino-dos-Santos-Franco, Adriana; Correa-Costa, Matheus; Durão, Ana Carolina Cardoso dos Santos; de Oliveira, Ana Paula Ligeiro; Breithaupt-Faloppa, Ana Cristina; Bertoni, Jônatas de Almeida; Oliveira-Filho, Ricardo Martins; Câmara, Niels Olsen Saraiva; Marcourakis, Tânia; Tavares-de-Lima, Wothan

    2011-12-15

    Formaldehyde (FA) is an indoor and outdoor pollutant widely used by many industries, and its exposure is associated with inflammation and oxidative stress in the airways. Our previous studies have demonstrated the role of reactive oxygen species (ROS) in lung inflammation induced by FA inhalation but did not identify source of the ROS. In the present study, we investigate the effects of FA on the activities and gene expression of glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST), superoxide dismutase (SOD) 1 and 2, catalase (CAT), nitric oxide synthase (iNOS and cNOS) and cyclooxygenase (COX) 1 and 2. The hypothesized link between NADPH-oxidase, nitric oxide synthase and cyclooxygenase, the lung inflammation after FA inhalation was also investigated. For experiments, male Wistar rats were submitted to FA inhalation (1%, 90 min daily) for 3 consecutive days. The treatments with apocynin and indomethacin before the FA exposure reduced the number of neutrophils recruited into the lung. Moreover, the treatments with apocynin and indomethacin blunted the effect of FA on the generation of IL-1β, while the treatments with L-NAME and apocynin reduced the generation of IL-6 by lung explants when compared to the untreated group. FA inhalation increased the levels of NO and hydrogen peroxide by BAL cells cultured and the treatments with apocynin and l-NAME reduced these generations. FA inhalation did not modify the activities of GPX, GR, GST and CAT but reduced the activity of SOD when compared to the naïve group. Significant increases in SOD-1 and -2, CAT, iNOS, cNOS and COX-1 expression were observed in the FA group compared to the naïve group. The treatments with apocynin, indomethacin and L-NAME reduced the gene expression of antioxidant and oxidant enzymes. In conclusion, our results indicate that FA causes a disruption of the physiological balance between oxidant and antioxidant enzymes in lung tissue, most likely favoring the

  7. Oxidative stress and antioxidative mechanisms in tomato (solanum lycopersicum l.) plants sprayed with different pesticides

    International Nuclear Information System (INIS)

    A glasshouse experiment was conducted to appraise the influence of exogenously applied pesticides such as abamectin, thiamethoxam, pyriproxyfen and acetamiprid on oxidative defence system and some key physiological attributes in tomato (Solanum lycopersicum L.). Each of these pesticides was applied in three doses (recommended dose, twice and three times higher than the recommended dose). Higher doses of pesticides sprayed to the plants resulted in marked increase in leaf free proline content and electrolyte leakage, but in a decrease in shoot dry matter, chl a, chl b and chl a+b in tomato plants as compared to those plants not sprayed with pesticides. These reductions were greater in tomato plants sprayed with highest doses of thiamethoxam (144 mg L-1), whereas the reverse was true for proline content and electrolyte leakage. The foliar application of pesticides at the highest levels caused enhanced accumulation of malondialdehyde (MDA) in most cases, and these being greater in treatment of foliar application of thiamethoxam at the highest level. The highest doses of pesticides promoted the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) in most cases. The results clearly indicate that application of pesticides at higher doses than recommended doses provoked both oxidative and antioxidative systems in tomato plants. (author)

  8. Oxidative Response and Antioxidative Mechanism in Germinating Soybean Seeds Exposed to Cadmium

    Directory of Open Access Journals (Sweden)

    Shiyong Yang

    2012-08-01

    Full Text Available Seeds of soybean (Glycine max L. exposed to 50 mg/L (Cd50, 100 mg/L (Cd100 and 200 mg/L (Cd200 cadmium solution for 24, 48, 72 and 96 h were examined with reference to Cd accumulation, oxidative stress and antioxidative responses. Soybean seeds accumulated Cd in an exposure time-and dosage-dependent manner. FRAP (ferric reducing ability of plasma concentration, GSH/hGSH content, and GST activity showed a pronounced exposure time-dependent response. Cd100 enhanced FRAP concentration in germinating soybean seeds as compared to Cd50 treatment after 24 h exposure. Cd200 however increased statistically GST activities after 72 and 96 h exposure. Under all Cd dosages, GSH/hGSH concentrations were depressed with increasing exposure time. Reduction of GSH/hGSH content and concomitant increase of GST activity suggested a possible participation of GSH into GSH-Cd conjugates synthesis. MDA content is a potential biomarker for monitoring Cd phytotoxicity because it responds significantly to treatment dosage, exposure time and dosage ´ exposure time interaction. Increase of proline content may be a response to acute heavy metal toxicity in soybean seeds.

  9. Mechanisms of antioxidant activity: The DFT study of hydrogen abstraction from phenol and toluene by the hydroperoxyl radical

    Energy Technology Data Exchange (ETDEWEB)

    Luzhkov, Victor B. [Department of Cell and Molecular Biology, Uppsala University, BMC, Box 596, S-751 24 Uppsala (Sweden)], E-mail: vluz@xray.bmc.uu.se

    2005-07-18

    Results from theoretical study of hydrogen abstraction from phenol and toluene by the hydroperoxyl radical are reported. The free radical reactions considered have rates differing by six orders of magnitudes yet have nearly equal reaction heats. The corresponding potential energy profiles and reaction mechanisms are studied using the DFT B3LYP/6-311+G(2d,2p) method. The calculations correctly predict the large difference in activation energies, {delta}E {sub a}, for the reactions considered, both in gas phase and nonpolar solvent. However, quantitatively the {delta}E {sub a} is overestimated by 11-12 kJ/mol. The difference of the computed bond-dissociation energies can be compared to {delta}E {sub a}. The electron structure analysis of the reaction intermediates shows that the conventional H-atom transfer is described by differing qualitative mechanisms for the considered processes. The phenol-peroxyl reaction has the features of proton-coupled electron transfer, while the toluene-peroxyl reaction is closer to neutral H-atom transfer. The found difference of the reaction mechanisms gives a new perspective for rationalization of the highly differing reactivity of phenolic antioxidants and hydrocarbons towards peroxyl radicals.

  10. ANTIOXIDANT MUSHROOMS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Aggarwal Preeti

    2012-06-01

    Full Text Available The antioxidant properties of wild mushrooms have been extensively studied and many antioxidant compounds such as phenolic compounds, tocopherols, ascorbic acid, and carotenoids identified. The various antioxidant mechanisms of the mushroom species extracts may be attributed to strong hydrogen-donating ability, metal-chelating ability, and their effectiveness as good scavengers of superoxide and free radicals. This indicates the potential of mushrooms as panacea for many diseases and also reveals a novel potential to fight against tumors in man.

  11. Effect of isoorientin on intracellular antioxidant defence mechanisms in hepatoma and liver cell lines.

    Science.gov (United States)

    Yuan, Li; Wang, Jing; Wu, Wanqiang; Liu, Qian; Liu, Xuebo

    2016-07-01

    Isoorientin (ISO) is considered one of the most important flavonoid-like compounds responsible for health benefits, including the prevention of liver damage as well as antioxidant, anti-inflammatory, and anti-nociceptive activities. Our previous study showed that ISO inhibited the proliferation of hepatoma cells through increasing intracellular ROS levels. Interestingly, ISO protects rat liver cells against hydrogen peroxide-induced oxidation stress by decreasing intracellular ROS levels. Why are there different effects of ISO on ROS in different physiological and pathophysiological circumstances? The present study investigated the effect of ISO on mitochondrial respiratory chain complexes and phase II detoxifying enzyme activities in human hepatoblastoma cancer cells (HepG2), buffalo rat liver cells (BRL-3A) and human liver cancer cells (HL-7702). The results showed that intracellular ROS levels and the protein expression of the respiratory chain complexes was significantly (p<0.01) higher in the HepG2 cells than in the BRL-3A and HL-7702 cells. Additionally, ISO notably (p<0.01) increased ROS levels in the HepG2 cells, while no significance was found in the BRL-3A and HL-7702 cells. Furthermore, in the HepG2 cells, the protein expression of the respiratory chain complexes and the phase II detoxifying enzyme activities and GSH content were decreased by ISO (p<0.01), while ISO, in a certain range, enhanced the expression of the protein complexes and the phase II detoxifying enzyme activities and GSH content in BRL-3A and HL-7702 cells. All of these results demonstrated, for the first time, that ISO possesses a notable hepatoprotective effect, which might be mediated through the respiratory chain complexes and phase II detoxifying enzyme activities. PMID:27261613

  12. INTERRELATION OF THE PHYSICAL IMAGE OF "I" AND THE PSYCHOLOGICAL DEFENSE MECHANISM OF DISABLED PERSON WITH THE DEFEAT OF THE MUSCULOSKELETAL SYSTEM

    Directory of Open Access Journals (Sweden)

    A. V. GOLTSOV

    2016-01-01

    Full Text Available The article contains the results of an empirical study based on identifying characteristics of the relationship of psychological defense mechanisms of personality and physical image "I" disabled with damage to the musculoskeletal system. Disability is associated with lesions of the musculoskeletal system and was due to a variety of injuries, according to their psychological effect, is a serious and difficult going through a crisis of identity. The author substantiates the relevance of the study, determines the degree of its scientific elaboration, formulates a hypothesis and tests it in the course of empirical research. The study found that self-pity, self-centeredness determines the attractiveness of anatomical exaggeration and social characteristics of the physical image of "I", as well as resentment, vulnerability, ambition, jealousy, hostility. The desire to overcome the traumatic circumstances, to correct their shortcomings determines an increase in the distortion of the image of the functional characteristics of the physical "I". Rationalization is the mechanism of psychological defense, determines the adequacy of their perception of physicality and desire for self-management of their physical "I".

  13. Antioxidant Defenses in the Ocular Surface

    OpenAIRE

    Chen, Ying; Mehta, Gaurav; Vasiliou, Vasilis

    2009-01-01

    The human eye is subjected constantly to oxidative stress due to daily exposure to sunlight, high metabolic activities, and oxygen tension. Reactive oxygen species generated from environmental insults and pathological conditions render the human eye particularly vulnerable to oxidative damage. The ocular surface composed of the tear film, the cornea, and the aqueous humor forms the first physical and biochemical barrier of the eye and plays a pivotal role in combating free radicals. These ocu...

  14. Rationale for Antioxidant Supplementation in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Morena Marion

    2001-01-01

    Full Text Available Oxidative stress, which results from an imbalance between reactive oxygen species (ROS production and antioxidant defense mechanisms, is now a well recognized pathogenic process in hemodialysis (HD patients that could be involved in dialysis-related pathologies such as accelerated atherosclerosis, amyloidosis and anemia. This review is aimed at evaluating the rationale for preventive intervention against oxidative damage during HD as well as the putative causal factors implicated in this imbalance. The antioxidant system is severely impaired in uremic patients and impairment increases with the degree of renal failure. HD further worsens this condition mainly by losses of hydrophilic unbound small molecular weight substances such as vitamin C, trace elements and enzyme regulatory compounds. Moreover, inflammatory state due to the hemo-incompatibility of the dialysis system plays a critical role in the production of oxidants contributing further to aggravate the pro-oxidant status of uremic patients. Prevention of ROS overproduction can be achieved by improvement of dialysis biocompatibility, a main component of adequate dialysis, and further complimented by antioxidant supplementation. This could be achieved either orally or via the extracorporeal circuit. Antioxidants such as vitamin E could be bound on dialyzer membranes. Alternatively, hemolipodialysis consisting of loading HD patients with vitamin C or E via an ancillary circuit made of vitamin E-rich liposomes may be used.

  15. Glucose utilization and anti-oxidative mechanisms of the aqueous hunteria umbellata seed extract in alloxan-induced diabetic rats.

    Science.gov (United States)

    Adeneye, A A; Adenekan, S O; Adeyemi, O O; Agbaje, E O

    2014-01-01

    In South-west Nigeria, water decoctions of Hunteria umbellata seeds are highly valued by traditional healers in the local management of diabetes mellitus, obesity and hyperlipidemia. Previous studies hypothesized one of the antihyperglycemic mechanisms of the aqueous seed extract of Hunteria umbellata (HU) to be mediated probably via increased peripheral glucose utilization. The present study, therefore, was designed at evaluating the peripheral glucose utilization and anti-oxidative mechanisms of 50 mg/kg, 100 mg/kg and 200 mg/kg of HU in alloxan-induced diabetic rats in Groups IV-VI rats as well as in the control groups (Groups I-III). Experimental type 1 DM was induced in male Wistar rats through intraperitoneal injection of 150 mg/kg of alloxan monohydrate in cold 0.9% normal saline after which the diabetic rats were orally treated with 50-200 mg/kg of HU for 14 days. Effects of HU on the rat body weight, percentage body weight changes and fasting blood glucose (FBG) were determined on days 1 and 15 of the experiment. Also, on day 15 of the experiment, HU effect on serum insulin, liver enzyme markers, proteins, albumin, triglyceride, total cholesterol and lactate dehydrogenase as well as on hepatic tissue oxidative stress markers, liver glycogen and glucose-6-phosphatase were determined after sacrificing the rats under diethyl ether anesthesia. Results showed that oral treatments with 50-200 mg/kg of HU caused significant (pdiabetes, while causing significant (p0.05) alterations in the serum INS levels in the treated rats. Also, repeated oral treatment with HU caused significant (pdiabetes. Similar significant (plactate dehydrogenase as well as on hepatic tissue oxidative stress markers such as superoxidase dismutase (SOD), catalase (CAT), malonialdehyde (MDA) and reduced glutathione (GSH) of HU-treated rats when compared to that of untreated alloxan-induced diabetic rats. In conclusion, results of this study showed HU treatment to significantly ameliorate the

  16. Antihyperglycemic Potential of Grewia asiatica Fruit Extract against Streptozotocin-Induced Hyperglycemia in Rats: Anti-Inflammatory and Antioxidant Mechanisms

    Directory of Open Access Journals (Sweden)

    Hala A. H. Khattab

    2015-01-01

    Full Text Available Diabetes mellitus is regarded as a serious chronic disease that carries a high risk for considerable complications. In folk medicine, the edible Grewia asiatica fruit is used in a number of pathological conditions. This study aimed to investigate the possible curative effect of G. asiatica fruit ethanolic extract against streptozotocin- (STZ- induced hyperglycemia in rats. Furthermore, mechanism of antihyperglycemic action is investigated. Hyperglycemic rats are either treated with 100 or 200 mg/kg/day G. asiatica fruits extract. Serum glucose, liver glycogen, malondialdehyde (MDA, reduced glutathione (GSH, superoxide dismutase (SOD, interleukin- (IL- 1β, and tumor necrosis factor- (TNF- α are measured. G. asiatica fruits extract reduces blood glucose and pancreatic MDA levels. It increases liver glycogen and pancreatic GSH contents and SOD enzyme activity. Furthermore, Grewia asiatica fruits extract decreases serum IL-1β and TNF-α. The treatment also protects against STZ-induced pathological changes in the pancreas. The results of this study indicated that G. asiatica fruit extract exerts antihyperglycemic activity against STZ-induced hyperglycemia. The improvement in the pancreatic β-cells and antioxidant and anti-inflammatory effects of G. asiatica fruit extract may explain the antihyperglycemic effect.

  17. Antimicrobial defense of the earthworm

    Czech Academy of Sciences Publication Activity Database

    Bilej, Martin; De Baetselier, P.; Beschin, A.

    2000-01-01

    Roč. 45, č. 4 (2000), s. 283-300. ISSN 0015-5632 R&D Projects: GA ČR GA310/99/1385; GA ČR GA310/00/1372 Institutional research plan: CEZ:AV0Z5020903 Keywords : cellular defense mechanisms * humoral defense mechanisms Subject RIV: EE - Microbiology, Virology Impact factor: 0.752, year: 2000

  18. 达乌里胡枝子抗氧化防御系统对增强UV-B辐射的动态响应%Responses of Antioxidant Defense System of Lespedeza davurica to Enhanced UV-B Radiation

    Institute of Scientific and Technical Information of China (English)

    郝文芳; 杜润峰; 王龙飞

    2012-01-01

    为探究增强UV-B辐射对达乌里胡枝子(Lespedeza davrica)抗氧化能力的影响,采用盆栽试验研究其在不同UV-B辐射强度(CK=0,T1=1.944 kJ· m-2 ·d-1,T2=3.002 kJ·m-2·d-1)下的抗氧化保护系统相关指标的动态响应,UV-B辐射处理持续15 d,每3d取样一次至结束后第3d再取样一次.结果表明:随着处理时间的延长,增强UV-B辐射使超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性降低,抗坏血酸过氧化物酶(APX)和过氧化物酶(POD)活性升高,且SOD,POD和CAT的活性随着辐射强度的增加而降低,APX活性在开始处理9d内随着辐射强度的增加而增加,此后随着辐射强度的增加而降低;增强UV-B辐射使抗坏血酸(AsA)含量增加,类胡萝卜素(Car)含量降低,且二者的含量均随着辐射强度的增加而降低;增强UV-B辐射使超氧阴离子(Oi-)、丙二醛(MDA)含量升高,O2·-含量和MDA含量均随着辐射强度的增加而增加.UV-B处理结束后,除SOD活性、POD活性、AsA含量呈下降趋势外,其他指标都呈上升趋势.通过隶属函数法综合评价得出:增强UV-B辐射降低了达乌里胡枝子的抗氧化能力,随着UV-B辐射强度的增加,抗氧化能力降低.%The objective of this study was to investigate the effects of different UV-B radiation intensity (CK, T1. T2)on antioxidant defense system and other related indicators of Lespedeza davurica (Laxm. ) Schindl. Malonaldehyde (MDA), ascorbic acid (AsA) and carotenoid (Car) contents, as well as superox-ide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities of leaves from Lespedeza davurica under different UV-B radiation intensity were investigated. Samples were collected once every three days. The UV-B treatment was continued 15 days. Result indicated that SOD and POD activities decreased, APX and POD activities increased with UV-B radiation enhanced during the whole treatment time. SOD, POD and CAT activities decreased with UV

  19. Electro-Mechanical Manipulator for Use in the Remote Equipment Decontamination Cell at the Defense Waste Processing Facility, Savannah River Site - 12454

    International Nuclear Information System (INIS)

    One of the legacies of the cold war is millions of liters of radioactive waste. One of the locations where this waste is stored is at the Savannah River Site (SRS) in South Carolina. A major effort to clean up this waste is on-going at the defense waste processing facility (DWPF) at SRS. A piece of this effort is decontamination of the equipment used in the DWPF to process the waste. The remote equipment decontamination cell (REDC) in the DWPF uses electro-mechanical manipulators (EMM) arms manufactured and supplied by PaR Systems to decontaminate DWPF process equipment. The decontamination fluid creates a highly corrosive environment. After 25 years of operational use the original EMM arms are aging and need replacement. To support continued operation of the DWPF, two direct replacement EMM arms were delivered to the REDC in the summer of 2011. (authors)

  20. Quantitative Proteomic Analysis Reveals that Antioxidation Mechanisms Contribute to Cold Tolerance in Plantain (Musa paradisiaca L.;ABB Group) Seedlings

    Institute of Scientific and Technical Information of China (English)

    Qiaosong Yang; Junhua Wu; Chunyu Li; Yuerong Wei; Ou Sheng; Chunhua Hu; Ruibin Kuang

    2012-01-01

    Banana and its close relative,plantain are globally important crops and there is of considerable interest in optimizing their cultivation.Plantain has superior cold tolerance compared to banana and a thorough understanding of the molecular mechanisms and responses of plantain to cold stress has great potential value for developing cold tolerant banana cultivars.In this study,we used iTRAQ-based comparative proteomic analysis to investigate the temporal responses of plantain to cold stress.Plantain seedlings were exposed for 0,6 and 24 h of cold stress at 8℃ and subsequently allowed to recover for 24 h at 28℃.A total of 3,477 plantain proteins were identified,of which 809 showed differential expression from the three treatments.The majority of differentially expressed proteins were predicted to be involved in oxidation-reduction,including oxylipin biosynthesis,while others were associated with photosynthesis,photorespiration and several primary metabolic processes,such as carbohydrate metabolic process and fatty acid beta-oxidation.Western blot analysis and enzyme activity assays were performed on 7 differentially expressed,cold-response candidate plantain proteins in order to validate the proteomics data.Similar analyses of the 7 candidate proteins were performed in cold-sensitive banana to examine possible functional conservation and to compare the results to equivalent responses between the two species.Consistent results were achieved by Western blot and enzyme activity assays,demonstrating that the quantitative proteomics data collected in this study are reliable.Our results suggest that an increase of antioxidant capacity through adapted ROS scavenging capability,reduced production of ROS and decreased lipid peroxidation contribute to molecular mechanisms for the higher cold tolerance in plantain.To the best of our knowledge,this is the first report of a global investigation on molecular responses of plantain to cold stress by proteomic analysis.

  1. Implications of free radicals and antioxidant levels in carcinoma of the breast: A never-ending battle for survival

    Directory of Open Access Journals (Sweden)

    R J Sinha

    2009-01-01

    Full Text Available Background: Under normal circumstances, there is a steady balance between the production of oxygen derived free radicals and their destruction by the cellular antioxidant system inside the human body. However, any imbalance between the levels of these oxidants and antioxidants might cause DNA damage and may lead to cancer development. The aim of this study was to evaluate the level of antioxidants and free radicals in blood and tissue of cancer patients and compare these levels at different TNM stages to derive the possible role of free radicals and antioxidant enzymes in the etiology of breast cancer. Materials and Methods: This study includes 30 patients suffering from cancer breast and 20 patients as controls who had benign breast diseases. Circulating lipid peroxide (Malonyldialdehyde [MDA] levels and activities of the defensive enzymes (Superoxide Dismutase [SOD] and Catalase [CAT] were estimated in the blood and breast tissue of these patients. Results: Increased levels of free radicals and low levels of antioxidants were observed in malignant tissue. An elevated lipid peroxide concentration was found in the tissue of all the cancer breast patients as evidenced by an increase in the mean MDA level seen with increasing TNM stage of carcinoma breast. Levels of antioxidants SOD and CAT were decreased in cancer patients. Conclusion: The results of our study suggest that free radical activity is enhanced in cancer breast patients while the antioxidant defense mechanism is weakened. This activity is enhanced with the increasing severity of cancer as depicted in different TNM stages of breast cancer.

  2. Metabolism of oxidants and anti-oxidant protective mechanisms in dust exposed human lung cells; Oxidantienmetabolismus und anti-oxidative Schutzmechanismen in staubbelasteten, humanen Lungenzellen

    Energy Technology Data Exchange (ETDEWEB)

    Gillissen, A. [Berufsgenossenschaftliche Kliniken Bergmannsheil - Universitaetsklinik, Medizinische Klinik, Abt. fuer Pneumologie und Allergologie, Bochum (Germany); Jaworska, M. [Berufsgenossenschaftliche Kliniken Bergmannsheil - Universitaetsklinik, Medizinische Klinik, Abt. fuer Pneumologie und Allergologie, Bochum (Germany); Wickenburg, D. [Berufsgenossenschaftliche Kliniken Bergmannsheil - Universitaetsklinik, Medizinische Klinik, Abt. fuer Pneumologie und Allergologie, Bochum (Germany); Schultze-Werninghaus, G. [Berufsgenossenschaftliche Kliniken Bergmannsheil - Universitaetsklinik, Medizinische Klinik, Abt. fuer Pneumologie und Allergologie, Bochum (Germany)

    1994-04-01

    The effect of crocidolite fibers on cultivated human A549-Zells (epithelial like) were tested to induce or inhibit cellular {gamma}-glutamyl-cycle. The cells were exposed with increasing amounts of fibers (0 - 300 {mu}g/cm{sup 2}). Over a 48 h period glutathione has been determined intracellularly as well as extracellularly. Already low fiber concentrations resulted in a notable reduction of intracellular glutathione production. Extracellular glutathione levels augmented with increasing fiber concentrations. Due to increasing cytotoxicity, determined by LDH-release assay, extracellular glutathione increase seems to be related to direct cellular damage rather than to an ability to enhance the antioxidant protection screen on the cellular surface. In this context N-acetylcysteine (NAC) was tested in vitro to augment cellular oxidant capacity. It could be shown that NAC has intrinsic antioxidant capabilities as well as a potent glutathione precursor function. However, further experiments have to be done to determine if NAC can prevent dust related cell death. (orig.) [Deutsch] Es wurde in vitro in einem ersten Versuchsansatz an kultivierten A549-Zellen (eine humane Epithelzellinie) die Wirkung von UICC Krokydolith-Fasern auf den zellulaeren {gamma}-Glutamylzyklus untersucht. Den Zellen wurden steigende Konzentrationen von Krokidolith von 0 - 300 {mu}g/cm{sup 2} aufgelagert. Anschliessend wurden ueber einen Zeitraum von 1 - 48 Stunden sowohl intra- als auch extrazellulaer Glutathion-Bestimmungen durchgefuehrt. Es zeigte sich, dass schon geringe Krokydolith-Konzentrationen gegenueber den unbehandelten Zellen zu einer deutlichen Reduktion der intrazellulaeren Glutathion-Sekretion fuehrten. Die extrazellulaere Glutathion-Messungen zeigten einen Anstieg bei zunehmender Faserkonzentration. Da aber gleichzeitig auch der Zytotoxizitaetsindex (LDH-Release-Assay) deutlich anstieg scheint dieser extrazellulaere Glutathion-Anstieg mehr Ausdruck einer faserinduzierten

  3. [Anna Freud exposes herself to criticism. "The ego and and the mechanisms of defense" under the magnifying glass].

    Science.gov (United States)

    Elrod, N

    1991-12-01

    In the early 1970's members and guests of the Hampstead Clinic, under the guidance of Joseph Sandler, discussed Anna Freud's The Ego and the Mechanisms of Defence, which had been published in 1936, with its author. Elrod presents this discussion in excerpts and emphasizes the undogmatic approach to psychoanalytic theory evident in Anna Freud's and Joseph Sandler's contributions. PMID:1775644

  4. Antioxidant activities of [60]fullerene derivatives from chalcone, flavone and flavanone: A ONIOM approach via H-atom and electron transfer mechanism

    Science.gov (United States)

    Thong, Nguyen Minh; Dao, Duy Quang; Ngo, Thi Chinh; Huyen, Trinh Le; Nam, Pham Cam

    2016-05-01

    Antioxidant properties of C60 flavonoid conjugates were computationally examined via their O-H bond dissociation enthalpies (BDEs) and ionization energies (IEs) using two-layer ONIOM and PM6 methods, respectively. Eight ONIOM((RO)B3LYP/6-311++G(2df,2p):PM6) models were evaluated by computing BDE(O-H)s of a series of polyphenol. Synthetic mechanism of C60 flavonoid conjugates was also explored via the potential energy surfaces of reaction between C60 and malonate flavonoid derivatives (chalcone, flavone and flavanone) at the B3LYP/6-31G(d)//PM6. Antioxidant activities of C60 flavonoid conjugates were discussed via hydrogen atom transfer, single electron transfer mechanisms and the effect of C60 on the BDE(O-H)s and IEs of these compounds.

  5. Atmospheric oxidation and antioxidants

    CERN Document Server

    Meurant, Gerard

    2012-01-01

    Volume I reviews current understanding of autoxidation, largely on the basis of the reactions of oxygen with characterised chemicals. From this flows the modern mechanism of antioxidant actions and their application in stabilisation technology.

  6. Chemical analysis, antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

    Directory of Open Access Journals (Sweden)

    Meriem El Kolli

    2016-01-01

    Conclusions: D. gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane. These activities could be exploited in the food industry for food preservation.

  7. Influence of Various Antioxidants on the Characteristics of Plain Yogurt

    OpenAIRE

    Blake Brignac; Kayanush J. Aryana

    2012-01-01

    Free radical damage has been implicated in ageing and in certain degenerative conditions such as Alzheimer’s disease and other forms of dementia. Ageing is also associated with a progressive decline in the function of the immune system and an increased susceptibility to infection. Antioxidants protect the body from free radical damage. Vitamin E is the major antioxidant vitamin in body tissues and is considered the first line of defense against cell membrane damage. Other antioxidant defenses...

  8. Activation of chemical biological defense mechanisms and alleviation of in vivo oxidation injury by low dose radiation

    International Nuclear Information System (INIS)

    We clarified that adequate oxygen stress induced by low dose radiation activates not only chemical biological protective function, such as induction of the synthesis of superoxide dismutase (SOD), glutathione peroxidase (GPX) and heat shock protein 70 (HSP70), but also the biomembrane function, such as enhanced membrane fluidity and ATPase activity. It is possible that activation of these mechanisms alleviates in vivo oxidation injuries resulting in alleviation of pathologic condition, such as ferric-nitrilotriacetate (Fe3+-NTA) or CCl4-induced liver damage, 1-methyl-4-phenyl 1,2,3,6-tetrahydro-pyridine (MPTP)-induced brain damage and diabetes mellitus. Namely, in contrast to the toxic effects of high dose irradiation, adequate activation of the functions of the living body by low dose radiation or inhalation of an appropriate amount of radon can contribute to suppressing aging and to preventing or reducing active oxygen species related diseases which are thought to involve peroxidation and have been regarded as the diseases for which radon spring water is an effective treatment. In future, clarification in detail of the mechanisms of these phenomena is required to understand the effects of low dose radiation on the functions of the living body, including adaptive response. (author)

  9. The molecular mechanisms of OPA1-mediated optic atrophy in Drosophila model and prospects for antioxidant treatment.

    Directory of Open Access Journals (Sweden)

    Will Yarosh

    2008-01-01

    Full Text Available Mutations in optic atrophy 1 (OPA1, a nuclear gene encoding a mitochondrial protein, is the most common cause for autosomal dominant optic atrophy (DOA. The condition is characterized by gradual loss of vision, color vision defects, and temporal optic pallor. To understand the molecular mechanism by which OPA1 mutations cause optic atrophy and to facilitate the development of an effective therapeutic agent for optic atrophies, we analyzed phenotypes in the developing and adult Drosophila eyes produced by mutant dOpa1 (CG8479, a Drosophila ortholog of human OPA1. Heterozygous mutation of dOpa1 by a P-element or transposon insertions causes no discernable eye phenotype, whereas the homozygous mutation results in embryonic lethality. Using powerful Drosophila genetic techniques, we created eye-specific somatic clones. The somatic homozygous mutation of dOpa1 in the eyes caused rough (mispatterning and glossy (decreased lens and pigment deposition eye phenotypes in adult flies; this phenotype was reversible by precise excision of the inserted P-element. Furthermore, we show the rough eye phenotype is caused by the loss of hexagonal lattice cells in developing eyes, suggesting an increase in lattice cell apoptosis. In adult flies, the dOpa1 mutation caused an increase in reactive oxygen species (ROS production as well as mitochondrial fragmentation associated with loss and damage of the cone and pigment cells. We show that superoxide dismutase 1 (SOD1, Vitamin E, and genetically overexpressed human SOD1 (hSOD1 is able to reverse the glossy eye phenotype of dOPA1 mutant large clones, further suggesting that ROS play an important role in cone and pigment cell death. Our results show dOpa1 mutations cause cell loss by two distinct pathogenic pathways. This study provides novel insights into the pathogenesis of optic atrophy and demonstrates the promise of antioxidants as therapeutic agents for this condition.

  10. Atmospheric pressure photoionization mass spectrometry as a tool for the investigation of the hydrolysis reaction mechanisms of phosphite antioxidants

    Science.gov (United States)

    Papanastasiou, M.; McMahon, A. W.; Allen, N. S.; Johnson, B. W.; Keck-Antoine, K.; Santos, L.; Neumann, M. G.

    2008-08-01

    The hydrolysis reaction mechanism of phosphite antioxidants is investigated by liquid chromatography-mass spectrometry (LC/MS). The phosphites were chosen because they differed in chemical structure and phosphorus content. Dopant assisted-atmospheric pressure photoionization (DA-APPI) is chosen as the ion source for the ionization of the compounds. In our previous work, DA-APPI was shown to offer an attractive alternative to atmospheric pressure chemical ionization (APCI) since it provided background-ion free mass spectra and higher sensitivity [M. Papanastasiou, et al., Polymer Degradation and Stability 91 (11) (2006) 2675-2682]. In positive ion mode, the molecules are generally detected in their protonated form. In negative ion mode, the phosphites are unstable and only fragment ions are observed; these however, are characteristic of each phosphite and may be used for the identification of the analytes in complex mixtures. The analytes under investigation are exposed to accelerated humid ageing conditions and their hydrolytic pathway and stability is investigated. Different substituents around the phosphorus atom are shown to have a significant effect on the stability of the phosphites, with phenol substituents producing very hydrolytically stable structures. Alkanox P24 and PEP-36 follow a similar hydrolytic pathway via the scission of the first and then the second POphenol bonds, eventually leading to the formation of phenol, phosphorous acid and pentaerythritol as end products. HP-10 exhibits a rather different structure and the products detected suggest scission of either the POhydrocarbon or one of the POphenol bonds. A phenomenon similar to that of autocatalysis is observed for all phosphites and is attributed to the formation of dialkyl phosphites as intermediate products.

  11. Plausible mechanism of antioxidant action of Fagonia cretica linn, Rubia cordifolia and Tinospora cordifolia during ischemic reperfusion injury in rat hippocampus

    Directory of Open Access Journals (Sweden)

    A K Rawal

    2008-06-01

    Full Text Available Summary: Reactive oxygen species (ROS and nitrogen species (RNS have been implicated in a wide variety of diseases including cerebral ischemic neuronal damage. We have earlier demonstrated the antioxidant and anti-inflammatory properties of the herbs Rubia cordifolia (RC, Fagonia cretia linn (FC and Tinospora cordifolia (TC in rat hippocampal slices subjected to oxygen glucose deprivation (OGD. In this communication we have hypothesized that the herbs exert their antioxidant action by both, direct scavenging and decreased generation of superoxide, nitric oxide, peroxynitrite and hydroxyl free radicals. Treatment of OGD slices with RC, FC or TC significantly reduced the generation of the aforesaid radicals, nitric oxide synthase activity and increased Cu-Zn superoxide dismutase (Cu-Zn SOD enzyme levels in the cytosol. The herbs markedly inhibited inducible nitric oxide synthase (iNOS gene expression and up-regulated the expression of Cu-Zn SOD gene. Studies with electron paramagnetic resonance (EPR and ion selective electrode for nitric oxide radical have revealed that the herbs could directly scavenge the free radicals. Overall the three herbs modulated free radical generation both at the cytosolic as well as at the nuclear levels.   Industrial relevance: Reactive oxygen species (ROS and nitrogen species (RNS have been implicated in a wide variety of diseases including cerebral ischemic neuronal damage. Currently there is a race for discovering new and more effective and efficient antioxidants and anti-inflammatory molecules. However, most synthetic molecules have undesired side effects and therefore have proved to be deleterious to health in the long run. The present study aims at investigating whether or not RC, TC and FC have antioxidant properties and if they have, what is the mechanism of their action. Such an investigation will lead to the identification, purification and characterization of the antioxidant molecule(s in the said herbs

  12. Advances on Defensive Mechanisms of Dairy Cow Mammary Gland Infection%奶牛乳腺细菌感染防御机制研究进展

    Institute of Scientific and Technical Information of China (English)

    王敬; 雍康; 吴有华; 杨庆稳

    2014-01-01

    乳腺内细菌感染可引起奶牛慢性型、临床型和亚临床型乳房炎。不同临床结果的出现,主要与细菌感染后激活乳腺免疫系统的方式不同有关。清晰地认识乳腺免疫系统激活和调节机制,对制定有效防治方案很有必要。综述了大肠杆菌性乳房炎和金黄色葡萄球菌性乳房炎的乳腺防御机制,并对二者的免疫反应进行了比较,旨在为奶牛乳房炎的临床防治提供参考依据。%Intramammary bacterial infections can be caused by bovine clinical type, chronic and subclinical mastitis. Different clinical results are mainly related with bacterial infection after activating the immune system in different ways of breast. It is necessary to well understand the activation and regulation mechanism of the breast immune system for developing effective prevention programs. This paper reviews breast defensive mechanisms of the Escherichia coli mastitis and Staphylococcus auγreus mastitis and the immune response to the two bacteria.

  13. Antioxidative capacity and enzyme activity in Haematococcus pluvialis cells exposed to superoxide free radicals

    Institute of Scientific and Technical Information of China (English)

    刘建国; 张晓丽; 孙延红; 林伟

    2010-01-01

    The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in three cell types of Haematococcus pluvialis exposed to high concentrations of a superoxide anion radical (O2ˉ).The results show that defensive enzymes and astaxanthin-related mechanisms were both active in H.pluvialis during exposure to reactive oxygen species (ROS) such as Oˉ2.Astaxanthin reacte...

  14. In Vitro Cytoprotective Effects and Antioxidant Capacity of Phenolic Compounds from the Leaves of Swietenia macrophylla

    OpenAIRE

    Sônia Pamplona; Paulo Sá; Dielly Lopes; Edmar Costa; Elizabeth Yamada; Consuelo e Silva; Mara Arruda; Jesus Souza; Milton da Silva

    2015-01-01

    Swietenia macrophylla (mahogany) is a highly valued timber species, whereas the leaves are considered to be waste product. A total of 27 phenolic compounds were identified in aqueous extracts from mahogany leaves by comparing retention times and mass spectra data with those of authentic standards using LC-ESI-MS/MS. Polyphenols play an important role in plants as defense mechanisms against pests and pathogens and have potent antioxidant properties. In terms of health applications, interest ha...

  15. Herbal antioxidant in clinical practice:A review

    Institute of Scientific and Technical Information of China (English)

    Shashi Alok; Sanjay Kumar Jain; Amita Verma; Mayank Kumar; Alok Mahor; Monika Sabharwal

    2014-01-01

    Antioxidant-the word itself is magic. Using the antioxidant concept as a spearhead in proposed mechanisms for staving off so-called"free-radical"reactions, the rush is on to mine claims for the latest and most effective combination of free-radical scavenging compounds. We must acknowledge that such "radicals" have definitively been shown to damage all biochemical components such as DNA/RNA, carbohydrates, unsaturated lipids, proteins, and micronutrients such as carotenoids (alpha and beta carotene, lycopene), vitamins A, B6, B12, and folate. Defense strategies against such aggressive radical species include enzymes, antioxidants that occur naturally in the body (glutathione, uric acid, ubiquinol-10, and others) and radical scavenging nutrients, such as vitamins A, C, and E, and carotenoids. This paper will present a brief discussion of some well-and little-known herbs that may add to the optimization of antioxidant status and therefore offer added preventive values for overall health. It is important to state at the outset that antioxidants vary widely in their free-radical quenching effects and each may be individually attracted to specific cell sites. Further evidence of the specialized nature of the carotenoids is demonstrated by the appearance of two carotenoids in the macula region of the retina where beta-carotene is totally absent.

  16. Study on preventive factors and defense mechanism for death due to γ-ray exposure at sub-lethal dose

    International Nuclear Information System (INIS)

    Aiming to elucidate the recovery mechanism in the human body from radiation exposure, time course changes in the excretion of inorganic metals including Mn, Co, Fe and Zn, and their abundance ratios in various organs were investigated in irradiated mice. The previous study demonstrated that there are considerable differences on metal metabolism among the metals and exposure doses, 4 and 10 Gy. Especially, the subcutaneously injected 59Fe was hardly excreted from the whole body for 7 days, however, its abundance ratio was markedly decreased in the blood with an increase of radiation dose, but increased in the liver. In this study, blood samples were fractionated. One day after exposure (day 1), 59Fe abundance ratio markedly increased in plasma fraction and decreased in blood cell fraction, whereas on day 7, the ratios of both fractions were similar to those of non-radiated mice, indicating substantial progressing of recovery from exposure. Concerning the liver, 59Fe abundance ratios in soluble protein fractions were significantly changed by radiation on day 1, however, became similar to the non-radiated control on day 8. These results suggest that Fe metabolism is closely related to the recovery process from radiation damages. (M.N.)

  17. Induction of multixenobiotic defense mechanisms in resistant Daphnia magna clones as a general cellular response to stress.

    Science.gov (United States)

    Jordão, Rita; Campos, Bruno; Lemos, Marco F L; Soares, Amadeu M V M; Tauler, Romà; Barata, Carlos

    2016-06-01

    Multixenobiotic resistance mechanisms (MXR) were recently identified in Daphnia magna. Previous results characterized gene transcripts of genes encoding and efflux activities of four putative ABCB1 and ABCC transporters that were chemically induced but showed low specificity against model transporter substrates and inhibitors, thus preventing us from distinguishing between activities of different efflux transporter types. In this study we report on the specificity of induction of ABC transporters and of the stress protein hsp70 in clones selected to be genetically resistant to ABCB1 chemical substrates. Clones resistant to mitoxantrone, ivermectin and pentachlorophenol showed distinctive transcriptional responses of transporter protein coding genes and of putative transporter dye activities. Expression of hsp70 proteins also varied across resistant clones. Clones resistant to mitoxantrone and pentachlorophenol showed high constitutive levels of hsp70. Transcriptional levels of the abcb1 gene transporter and of putative dye transporter activity were also induced to a greater extent in the pentachlorophenol resistant clone. Observed higher dye transporter activities in individuals from clones resistant to mitoxantrone and ivermectin were unrelated with transcriptional levels of the studied four abcc and abcb1 transporter genes. These findings suggest that Abcb1 induction in D. magna may be a part of a general cellular stress response. PMID:27039215

  18. Reorganization of Extracellular Matrix in Placentas from Women with Asymptomatic Chagas Disease: Mechanism of Parasite Invasion or Local Placental Defense?

    Directory of Open Access Journals (Sweden)

    Juan Duaso

    2012-01-01

    Full Text Available Chagas disease, produced by the protozoan Trypanosoma cruzi (T. cruzi, is one of the most frequent endemic diseases in Latin America. In spite the fact that in the past few years T. cruzi congenital transmission has become of epidemiological importance, studies about this mechanism of infection are scarce. In order to explore some morphological aspects of this infection in the placenta, we analyzed placentas from T. cruzi-infected mothers by immunohistochemical and histochemical methods. Infection in mothers, newborns, and placentas was confirmed by PCR and by immunofluorescence in the placenta. T. cruzi-infected placentas present destruction of the syncytiotrophoblast and villous stroma, selective disorganization of the basal lamina, and disorganization of collagen I in villous stroma. Our results suggest that the parasite induces reorganization of this tissue component and in this way may regulate both inflammatory and immune responses in the host. Changes in the ECM of placental tissues, together with the immunological status of mother and fetus, and parasite load may determine the probability of congenital transmission of T. cruzi.

  19. Reorganization of Extracellular Matrix in Placentas from Women with Asymptomatic Chagas Disease: Mechanism of Parasite Invasion or Local Placental Defense?

    Science.gov (United States)

    Duaso, Juan; Yanez, Erika; Castillo, Christian; Galanti, Norbel; Cabrera, Gonzalo; Corral, Gabriela; Maya, Juan Diego; Zulantay, Inés; Apt, Werner; Kemmerling, Ulrike

    2012-01-01

    Chagas disease, produced by the protozoan Trypanosoma cruzi (T. cruzi), is one of the most frequent endemic diseases in Latin America. In spite the fact that in the past few years T. cruzi congenital transmission has become of epidemiological importance, studies about this mechanism of infection are scarce. In order to explore some morphological aspects of this infection in the placenta, we analyzed placentas from T. cruzi-infected mothers by immunohistochemical and histochemical methods. Infection in mothers, newborns, and placentas was confirmed by PCR and by immunofluorescence in the placenta. T. cruzi-infected placentas present destruction of the syncytiotrophoblast and villous stroma, selective disorganization of the basal lamina, and disorganization of collagen I in villous stroma. Our results suggest that the parasite induces reorganization of this tissue component and in this way may regulate both inflammatory and immune responses in the host. Changes in the ECM of placental tissues, together with the immunological status of mother and fetus, and parasite load may determine the probability of congenital transmission of T. cruzi. PMID:22007243

  20. Anti-oxidant activity of 6-gingerol as a hydroxyl radical scavenger by hydrogen atom transfer, radical addition and electron transfer mechanisms

    Indian Academy of Sciences (India)

    MANISH K TIWARI; P C MISHRA

    2016-08-01

    Mechanisms of anti-oxidant action of 6-gingerol as a hydroxyl radical scavenger have been investigated using the transition state theory within the framework of density functional theory. Hydrogen abstraction by a hydroxyl radical from the different sites of 6-gingerol and addition of the former to the different sites ofthe latter were studied. Electron transfer from 6-gingerol to a hydroxyl radical was also studied. Solvent effect in aqueous media was treated using the integral equation formalism of the polarizable continuum model (IEFPCM). Reaction rate constants in aqueous media were generally found to be larger than those in gas phase. The tunneling contributions to rate constants were found to be appreciable. Our results show that 6-gingerol is an excellent anti-oxidant and would scavenge hydroxyl radicals efficiently.

  1. Metabolism of oxidants and anti-oxidant protective mechanisms in dust exposed human lung cells; Oxidantienmetabolismus und anti-oxidative Schutzmechanismen in staubelasteten humanen Lungenzellen

    Energy Technology Data Exchange (ETDEWEB)

    Gillissen, A. [Berufsgenossenschaftliche Krankenanstalten Bergmannsheil, Bochum (Germany). Medizinische Klinik und Poliklinik; Jaworska, M. [Berufsgenossenschaftliche Krankenanstalten Bergmannsheil, Bochum (Germany). Medizinische Klinik und Poliklinik; Wickenburg, D. [Berufsgenossenschaftliche Krankenanstalten Bergmannsheil, Bochum (Germany). Medizinische Klinik und Poliklinik; Schultze-Werninghaus, G. [Berufsgenossenschaftliche Krankenanstalten Bergmannsheil, Bochum (Germany). Medizinische Klinik und Poliklinik

    1996-04-01

    The imbalance of the oxidant-antioxidant system in the human lung after fiber and dust exposure is to play a major pathophysiologic role in the development of diseases such as asbestosis and silicosis. We compared the effect of crocidolite and silica (SiO{sub 2}) with rockwool and basaltwool, both man made mineral fibers, (1) on the antioxidant system of bronchial epithelial cells (A549 and BEAS 2 B cell lines), and (2) on the stimulation of oxidant production (e.g. O{sub 2} and H{sub 2}O{sub 2}) of alveolar macrophages ex vivo. The alveolar macrophages were obtained from patients with asbestosis (n=8), patients with silicosis (n=10) and non-exposed volunteers (n=9). In both epithelial cell lines fiber/silica induced cytotoxicity increased dependent on incubation time and fiber/dust concentration. Simultaneously intracellular glutathione content decreased with increasing cytotoxicity. Within the particle groups crocidolite was the be most toxic fiber in all tests. Additional administration of N-acetylcysteine (NAC) - a thiol capable of scavenging oxygen radicals and having cellular glutathione precursor capabilities - reduced this cytotoxic effect significantly (p<0.05). In BEAS 2B cells intracellular glutathione and superoxide dismutase (SOD) levels rose after low fiber/dust concentrations (1 {mu}g/cm{sup 2}) and short incubation time (<5 h). However, at higher concentrations and longer incubation times glutathione and SOD levels decreased. In contrast, even at high concentrations (100 {mu}g/cm{sup 2}) and the longest incubation time (24 h) used, intracellular catalase levels did not decline. The most striking effects were detected after crocidolite, the smallest changes were found after rockwood exposure. In exposed alveolar macrophages rockwool and basaltwood caused less oxidant production than crocidolite and silica. Interestingly, even at highest concentrations (50 {mu}g/cm{sup 2}) rockwool exposure caused no significant change in oxidant release. (orig

  2. Active cyber defense: enhancing national cyber defense

    OpenAIRE

    Wong, Tiong Pern.

    2011-01-01

    With increased dependency on the Internet, cyber attacks are fast becoming an attractive option for state adversaries, in part because of the ease of hiding one's identity. In response, governments around the world are taking measures to improve their national cyber defenses. However, these defenses, which are generally passive in nature, have been insufficient to address the threat. This thesis explores the possibility of employing active cyber defenses to improve cyber defenses at the na...

  3. Priming of antiherbivore defensive responses in plants

    Institute of Scientific and Technical Information of China (English)

    Jinwon Kim; Gary W.Felton

    2013-01-01

    Defense priming is defined as increased readiness of defense induction.A growing body of literature indicates that plants (or intact parts of a plant) are primed in anticipation of impending environmental stresses,both biotic and abiotic,and upon the following stimulus,induce defenses more quickly and strongly.For instance,some plants previously exposed to herbivore-inducible plant volatiles (HIPVs) from neighboring plants under herbivore attack show faster or stronger defense activation and enhanced insect resistance when challenged with secondary insect feeding.Research on priming of antiherbivore defense has been limited to the HIPV-mediated mechanism until recently,but significant advances were made in the past three years,including non-HIPV-mediated defense priming,epigenetic modifications as the molecular mechanism of priming,and others.It is timely to consider the advances in research on defense priming in the plantinsect interactions.

  4. In silico comparative analysis and expression profile of antioxidant proteins in plants.

    Science.gov (United States)

    Sheoran, S; Pandey, B; Sharma, P; Narwal, S; Singh, R; Sharma, I; Chatrath, R

    2013-01-01

    The antioxidant system in plants is a very important defensive mechanism to overcome stress conditions. We examined the expression profile of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) using a bioinformatics approach. We explored secondary structure prediction and made detailed studies of signature pattern of antioxidant proteins in four plant species (Triticum aestivum, Arabidopsis thaliana, Oryza sativa, and Brassica juncea). Fingerprinting analysis was done with ScanProsite, which includes a large collection of biologically meaningful signatures. Multiple sequence alignment of antioxidant proteins of the different plant species revealed a conserved secondary structure region, indicating homology at the sequence and structural levels. The secondary structure prediction showed that these proteins have maximum tendency for α helical structure. The sequence level similarities were also analyzed with a phylogenetic tree using neighbor-joining method. In the antioxidant enzymes SOD, CAT and APX, three major families of signature were predominant and common; these were PKC_PHOSPHO_SITE, CK2_PHOSPHO_SITE and N-myristoylation site, which are functionally related to various plant signaling pathways. This study provides new strategies for screening of biomodulators involved in plant stress metabolism that will be useful for designing degenerate primers or probes specific for antioxidant. These enzymes could be the first line of defence in the cellular antioxidant defence pathway, activated due to exposure to abiotic stresses. PMID:23512671

  5. Antioxidant Stabilisation of Polymers

    Science.gov (United States)

    Shlyapnikov, Yurii A.

    1981-06-01

    Physicochemical aspects of the stabilisation of polymers are discussed. Attention is paid mainly to the aging and stabilisation of polymers under processing conditions. Topics considered are the kinetics and mechanism of the high-temperature oxidation of polymers, critical phenomena in the inhibited oxidation of polymers, the theory of synergism and antagonism among antioxidants, the reasons for differences in efficiency of antioxidants, and certain aspects of the relation between the efficiency of antioxidants and their molecular structure. A list of 132 references is included.

  6. Molecular strategies of plant defense and insect counter-defense

    Institute of Scientific and Technical Information of China (English)

    KEYANZHU-SALZMAN; JIAN-LONGBI; TONG-XIANLIU

    2005-01-01

    The prediction of human population growth worldwide indicates there will be a need to substantially increase food production in order to meet the demand on food supply.This can be achieved in part by the effective management of insect pests. Since plants have co-evolved with herbivorous insects for millions of years, they have developed an array of defense genes to protect themselves against a wide variety of chewing and sucking insects.Using these naturally-occurring genes via genetic engineering represents an environmentally friendly insect pest-control measure. Insects, however, have been actively evolving adaptive mechanisms to evade natural plant defenses. Such evolved adaptability undoubtedly has helped insects during the last century to rapidly overcome a great many humanimposed management practices and agents, including chemical insecticides and genetically engineered plants. Thus, better understanding of the molecular and genetic basis of plant defense and insect counter-defense mechanisms is imperative, not only from a basic science perspective, but also for biotechnology-based pest control practice. In this review, we emphasize the recent advance and understanding of molecular strategies of attack-counterattack and defense-counter-defense between plants and their herbivores.

  7. Antioxidant Mechanism is Involved in the Gastroprotective Effects of Ozonized Sunflower Oil in Ethanol-Induced Ulcers in Rats

    Directory of Open Access Journals (Sweden)

    Zullyt B. Zamora Rodríguez

    2007-01-01

    In summary, our results demonstrate that OSO pretreatment exerts protective effects in ethanol-induced gastric ulcers in rats. Furthermore, these results provide evidence that these protective effects of OSO are mediated at least partially by stimulation of some important antioxidant enzymes such as SOD and GSH-Px, which are scavengers of ROS and therefore prevent gastric injury induced by them.

  8. Effects of vitamin E on mercuric chloride-induced renal interstitial fibrosis in rats and the antioxidative mechanism

    Directory of Open Access Journals (Sweden)

    Yan-yan Tao

    2011-02-01

    Full Text Available Objective: To observe the effects of vitamin E (Vit E on mercuric chloride (HgCl2-induced renal interstitial fibrosis (RIF in rats and discuss its antioxidative mechanism. Methods: A total of 32 Sprague-Dawley rats were randomly assigned to three groups: normal group, model group and Vit E group. RIF was induced by oral administration of HgCl2 at a dose of 8 mg/kg body weight once a day for 9 weeks. Rats in Vit E group were administered with Vit E capsule at 100 mg/kg body weight, and rats in normal and model groups were treated with normal saline. At the end of the 9th week, rats were sacrificed and renal hydroxyproline (Hyp content was assayed with Jamall’s method and collagen deposition was visualized by using hematoxylin and eosin (HE, Masson’s trichrome and periodic acid-silver methenamine (PASM staining. The activities of superoxide dismutase (SOD and glutathione peroxidase (GSH-Px, and contents of glutathione (GSH and malondialdehyde (MDA in kidney tissue were tested with commercial kits. The expressions of nuclear factor-κB (NF-κB, inhibitor-κB (IκB, phospho-IκB (p-IκB and tumor necrosis factor-α (TNF-α were determined by Western blot. The expression of α-smooth muscle actin (α-SMA was assayed by Western blot and immunofluorescent staining.Results: Renal Hyp content, HE, Masson’s trichrome and PASM staining results and α-SMA expression confirmed development of HgCl2-induced RIF in rats. Oxidative stress markers GSH, GSH-Px and MDA confirmed oxidative stress in RIF rats. Compared with model rats, rats in Vit E group had lower kidney Hyp content (P0.05. In Vit E group, the expressions of p-IκB and TNF-α decreased significantly compared with model group (P<0.01. The expression of α-SMA in Vit E group was also decreased significantly compared with model group (P<0.01. Conclusion: Vit E has a protective effect on experimental RIF induced by HgCl2 in rats and it is related to inhibition of lipid peroxidation, which involves

  9. Plasma antioxidants from chocolate

    OpenAIRE

    Serafini, M.; Bugianesi, R.; Maiani, G; Valtuena, S.; De Santis, S.; Crozier, A.

    2003-01-01

    There is some speculation that dietary flavonoids from chocolate, in particular (-)epicatechin, may promote cardiovascular health as a result of direct antioxidant effects or through antithrombotic mechanisms. Here we show that consumption of plain, dark chocolate results in an increase in both the total antioxidant capacity and the (-)epicatechin content of blood plasma, but that these effects are markedly reduced when the chocolate is consumed with milk or if milk is incorporated as milk ch...

  10. The role of nutritional lipids and antioxidants in UV-induced skin cancer.

    Science.gov (United States)

    Black, Homer S

    2015-01-01

    Two dietary tenets of the free radical theory of cancer require refinement. The first was dietary reduction of vulnerable free-radical targets, e.g., polyunsaturated lipids. The second was the addition of one or more antioxidants to the diet. Further, it was reported in 1939 that high levels of dietary fat exacerbated UV-carcinogenesis. Both lines of enquiry (dietary lipid and antioxidant effects on UV-carcinogenesis) were investigated. Both dietary lipids and antioxidants modified carcinogenic expression. Increasing levels of omega-6 polyunsaturated fatty acids (PUFA) exacerbated UV-carcinogenesis. However, omega-3 PUFA dramatically inhibited carcinogenic expression. It is probable that the action of omega-6 and-3 PUFA rests with differential metabolic intermediates, both tumor promoting and immune-modulating, that each PUFA generates through lipoxygenase and cyclooxygenase pathways. Antioxidant supplementation with butylated hydroxytoluene or beta-carotene demonstrated that each exerted its own specific antioxidant mechanism(s). When introduced into the complex milieu of the cell with its own intricate and complex antioxidant defense system, detrimental effects may ensue. These results point to oversimplification of these dietary suggestions to reduce cancer risk and the necessity to refine these dietary recommendations. PMID:25961684

  11. Study of a new alternative antioxidant in soybean plants subjected to abiotic stress

    International Nuclear Information System (INIS)

    We have recently, demonstrated that the induction of heme oxygenase-1 (HO-1) plays a protective role for soybean plants against oxidative stress produced by cadmium and UV-B radiation. At this moment we propose to investigate if the enzyme has the same capacity against another type of abiotic stress, such as drought, for to demonstrate that heme oxygenase acts as an enzyme of plant antioxidant defense system under several different stress situations, as occur in mammalian tissues. To carry out this objective we propose to study, in leaf, root and nodule of soybean plants, the oxidative stress generation; the behavior of classical antioxidant system; the behavior of HO-1 activity and protein and gene expression; the effect of its reaction products and inhibitors on the oxidative stress parameters; the signaling mechanism that produce HO-1 induction and the immunohistochemistry localization of the enzyme in the different plant tissues. The results obtained let us undoubtedly demonstrate the involvement of HO-1 in the antioxidant defense system in plants. This finding will allow the increase in the knowledge of the defense mechanisms in interesting economic plants for our country, such as soybean, and against drought, an abiotic stress considered one of the most important factors limiting plant performance and yield worldwide. (authors)

  12. Phenomenon of Psychological Defense

    Directory of Open Access Journals (Sweden)

    Elena T. Sokolova

    2011-01-01

    Full Text Available The author discusses the controversial issues of formation and functioning of psy¬chological defense mechanisms in ontogenesis and in personality disorders as they are represented in classical and contemporary psychoanalysis, in cognitivism and communication theory. The paper emphasizes the role of cognitive organi¬zation (style, sign-symbolic mediation, representative system of object relations and attachments in individual typological variability of the level organization of ciency of personal and social adaptation, in maturity and mental health of personality

  13. Chemical and mechanical defenses vary among maternal lines and leaf ages in Verbascum thapsus L. (Scrophulariaceae) and reduce palatability to a generalist insect

    Czech Academy of Sciences Publication Activity Database

    Alba, Christina; Bowers, M. D.; Blumenthal, D.; Hufbauer, R. A.

    2014-01-01

    Roč. 9, č. 8 (2014), s. 1-11, e104889. E-ISSN 1932-6203 Institutional support: RVO:67985939 Keywords : iridoid glycoside * plant defense * herbivory Subject RIV: EF - Botanics Impact factor: 3.234, year: 2014

  14. Antioxidant activity of Citrus fruits.

    Science.gov (United States)

    Zou, Zhuo; Xi, Wanpeng; Hu, Yan; Nie, Chao; Zhou, Zhiqin

    2016-04-01

    Citrus is well-known for its nutrition and health-promotion values. This reputation is derived from the studies on the biological functions of phytochemicals in Citrus fruits and their derived products in the past decades. In recent years, the antioxidant activity of Citrus fruits and their roles in the prevention and treatment of various human chronic and degenerative diseases have attracted more and more attention. Citrus fruits are suggested to be a good source of dietary antioxidants. To have a better understanding of the mechanism underlying the antioxidant activity of Citrus fruits, we reviewed a study on the antioxidant activity of the phytochemicals in Citrus fruits, introduced methods for antioxidant activity evaluation, discussed the factors which influence the antioxidant activity of Citrus fruits, and summarized the underlying mechanism of action. Some suggestions for future study were also presented. PMID:26593569

  15. Antioxidative Mechanisms of Sulfite and Protein-Derived Thiols during Early Stages of Metal Induced Oxidative Reactions in Beer.

    Science.gov (United States)

    Lund, Marianne N; Krämer, Anna C; Andersen, Mogens L

    2015-09-23

    The radical-mediated reactions occurring during the early stages of beer storage were studied by following the rate of oxygen consumption, radical formation as detected by electron spin resonance spectroscopy, and concentrations of the antioxidant compounds sulfite and thiols. Addition of either Fe(III) or Fe(II) had similar effects, indicating that a fast redox equilibrium is obtained between the two species in beer. Addition of iron in combination with hydrogen peroxide gave the most pronounced levels of oxidation due to a direct initiation of ethanol oxidation through generation of hydroxyl radicals by the Fenton reaction. The concentration of sulfite decreased more than the thiol concentration, suggesting that thiols play a secondary role as antioxidants by mainly quenching 1-hydroxyethyl radicals that are intermediates in the oxidation of ethanol. Increasing the temperature had a minor effect on the rate of oxygen consumption. PMID:26325117

  16. New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate

    OpenAIRE

    Hae-Suk Kim; Quon, Michael J.; Jeong-a Kim

    2014-01-01

    Green tea is rich in polyphenol flavonoids including catechins. Epigallocatechin 3-gallate (EGCG) is the most abundant and potent green tea catechin. EGCG has been extensively studied for its beneficial health effects as a nutriceutical agent. Based upon its chemical structure, EGCG is often classified as an antioxidant. However, treatment of cells with EGCG results in production of hydrogen peroxide and hydroxyl radicals in the presence of Fe (III). Thus, EGCG functions as a pro-oxidant in s...

  17. Putative mechanism for apoptosis-inducing properties of crude saponin isolated from sea cucumber (Holothuria leucospilota) as an antioxidant compound

    OpenAIRE

    Mozhgan Soltani; Kazem Parivar; Javad Baharara; Mohammad Amin Kerachian; Javad Asili

    2015-01-01

    Objective(s): Marine organisms are known as a potential source of natural products, which contain bioactive substances with therapeutic properties. Sea cucumbers are prominent among marine organisms because of their dietary and therapeutic applications. In addition, they have capacity of synthesizing saponins molecules and other metabolites with therapeutic properties such as antitumor, antimicrobial, anti-inflammatory and antioxidant activities. The aim of this study was to evaluate the anti...

  18. Change in defense mechanisms and coping patterns during the course of 2-year-long psychotherapy and psychoanalysis for recurrent depression: a pilot study of a randomized controlled trial.

    Science.gov (United States)

    Kramer, Ueli; de Roten, Yves; Perry, J Christopher; Despland, Jean-Nicolas

    2013-07-01

    Very little research has been conducted so far to study the potential mechanisms of change in long-term active psychological treatments of recurrent depression. The present pilot randomized controlled trial aimed to determine the feasibility of studying the change process occurring in patients during the course of 2-year-long dynamic psychotherapy, psychoanalysis, and cognitive therapy, as compared with clinical management. In total, eight outpatients presenting with recurrent depression, two patients per treatment arm, were included. All patients were randomly assigned to one of the four treatment conditions. Defense mechanisms and coping patterns were assessed using validated observer-rated methodology based on transcribed, semistructured follow-along independent dynamic interviews. The results indicated that, whereas some patients in the active treatments changed on the symptomatic levels, some others remained unchanged during the course of their 2-year-long treatment. However, with regard to potential mechanisms of change in these patients, changes in defense mechanisms and coping patterns were revealed to be important processes over time in successful therapies and, to a lesser extent, in less successful treatments. No change was found either on outcome or on the process measure for the control condition, that is, clinical management. These results are discussed along with previous data comparing change in defense mechanisms and coping during the course of treatments. PMID:23817160

  19. Red Sea Suberea mollis Sponge Extract Protects against CCl4-Induced Acute Liver Injury in Rats via an Antioxidant Mechanism

    Directory of Open Access Journals (Sweden)

    Aymn T. Abbas

    2014-01-01

    Full Text Available Recent studies have demonstrated that marine sponges and their active constituents exhibited several potential medical applications. This study aimed to evaluate the possible hepatoprotective role as well as the antioxidant effect of the Red Sea Suberea mollis sponge extract (SMSE on carbon tetrachloride- (CCl4- induced acute liver injury in rats. In vitro antioxidant activity of SMSE was evaluated by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH assay. Rats were orally administered three different concentrations (100, 200, and 400 mg/kg of SMSE and silymarin (100 mg/kg along with CCl4 (1 mL/kg, i.p., every 72 hr for 14 days. Plasma aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, and total bilirubin were measured. Hepatic malondialdehyde (MDA, reduced glutathione (GSH, nitric oxide (NO, superoxide dismutase (SOD, glutathione peroxidase (GPx, and catalase (CAT were also measured. Liver specimens were histopathologically examined. SMSE showed strong scavenging activity against free radicals in DPPH assay. SMSE significantly reduced liver enzyme activities. Moreover, SMSE significantly reduced hepatic MDA formation. In addition, SMSE restored GSH, NO, SOD, GPx, and CAT. The histopathological results confirmed these findings. The results of this study suggested a potent protective effect of the SMSE against CCl4-induced hepatic injury. This may be due to its antioxidant and radical scavenging activity.

  20. Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5.

    Science.gov (United States)

    Saenen, Eline; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Biermans, Geert; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-01-01

    To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed. PMID:26042463