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Sample records for antioxidant defense mechanisms

  1. Antioxidative defense mechanisms in the aging brain

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    Jovanović Zorica

    2014-01-01

    Full Text Available Aging is an extremely complex, multifactorial process that is characterized by a gradual and continuous loss of physiological functions and responses, particularly marked in the brain. A common hallmark in aging and age-related diseases is an increase in oxidative stress and the failure of antioxidant defense systems. Current knowledge indicates that the level of glutathione progressively declines during aging. Because nerve cells are the longest-living cells that exhibit a high consumption rate of oxygen throughout an individual’s lifetime, the brain may be especially vulnerable to oxidative damage and this vulnerability increases during aging. In addition, the brain contains high concentrations of polyunsaturated fatty acids and transition metals and low antioxidative defense mechanisms. Although aging is an inevitable event, a growing volume of data confirms that antioxidant supplementation in combination with symptomatic drug treatments reduces oxidative stress and improves cognitive function in aging and age-related diseases. The present review discusses the neuroprotective effects of antioxidants in the aging brain.

  2. Antioxidative defense

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    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.

  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. Synergistic defensive mechanism of phytochelatins and antioxidative enzymes in Brassica chinensis L. against Cd stress

    Institute of Scientific and Technical Information of China (English)

    CHEN LiQin; GUO YiFei; YANG LiMin; WANG QiuQuan

    2008-01-01

    Brassica chinensis L. was chosen and exposed to different concentrations of Cd exposure to evaluate its Cd-accumulating capacity and its potential cellular defensive mechanisms. Cd accumulation in the shoots and roots of B. chinensis was up to 1348.3±461.8 and 3761.0±795.0 mg per killogram of dry weight, respectively, under 200 μmol/L of Cd exposure. Increasing Cd accumulation in the plant was accompanied by rapid accumulation of phytochelatins (PCs), and the sequestration of Cd by PCs pro-vided a primary cellular mechanism for Cd detoxification and tolerance of B. chinensis. Furthermore, malondialdehyde formation, hydrogen peroxide content and antioxidative enzyme activities such as superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase were observed in the shoots of Cd-stressed B. chinensis. Increasing enzyme activities in response to concentrations of 5 to 50 μmol/L Cd showed an efficient defense against oxidative stress, suggesting that the antioxidative system was a secondary defensive mechanism. These resulted in reduced free Cd damage and en-hanced Cd accumulation and tolerance. Glutathione plays a pivotal role in these two detoxification pathways. In general, these results suggested that PCs and the antioxidative system are synergistic in combatting Cd-induced oxidative stress and that they play important roles in Cd detoxification of B. chinensis, and also give a deep understanding of the natural defensive mechanisms in plants under heavy metal stress.

  5. 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

  6. Attenuation of cellular antioxidant defense mechanisms in kidney of rats intoxicated with carbofuran.

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    Kaur, Bhupindervir; Khera, Alka; Sandhir, Rajat

    2012-10-01

    Carbofuran, an anticholinestrase carbamate, is commonly used as an insecticide. Its toxic effect on kidney is less established. The present study was designed to investigate the effect of carbofuran on kidneys and to understand the mechanism involved in its nephrotoxicity. Male Wistar rats were divided into two groups of eight animals each; control animals received sunflower oil (vehicle) and carbofuran exposed animals were treated with carbofuran (1 mg/kg body weight) orally for 28 days. At the end of the treatment, significant increase was observed in urea and creatinine levels in serum along with the inhibition of acetylcholinesterase, suggesting nephrotoxicity. The antioxidant defense system of animals treated with carbofuran was altered in terms of increased lipid peroxidation, reduced glutathione, and total thiols and decreased activity of antioxidant enzymes (superoxide dismutase and catalase). The results indicate that carbofuran is nephrotoxic and increased oxidative stress appears to be involved in its nephrotoxic effects.

  7. Triiodothyronine and melatonin influence antioxidant defense mechanism in a teleost Anabas testudineus (Bloch): in vitro study.

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    Sreejith, P; Beyo, R S; Divya, L; Vijayasree, A S; Manju, M; Oommen, O V

    2007-06-01

    The effect of the hormones triiodothyronine (T3) and melatonin on antioxidant defense system was studied in 6-propyl thiouracil (6-PTU)-treated or photoperiod-exposed teleost Anabas testudineus. 6-PTU (2 microg/g) treatment or photoperiod exposure (24 h) increased malondialdehyde (MDA) and conjugated dienes (CD) concentrations, indicating increased lipid peroxidation (LPO) in the experimental conditions. T3 or melatonin (10(-6) M) treatment for 15 min in vitro in PTU-treated fish reversed the activity of superoxide dismutase (SOD), catalase and glutathione content. T3-treated group showed no change in glutathione peroxidase (GPx) activity, whereas melatonin treatment decreased its activity. T3 inhibited glutathione reductase (GR) activity. Photoperiod exposure (physiological pinealotomy) induced a stressful situation in this teleost, as evidenced by LPO products and antioxidant enzyme activities. Melatonin and T3 treatment for 15 min in vitro also reversed the effect of photoperiod on peroxidation products and the SOD and catalase activities. GR activity decreased in photoperiod-exposed group and melatonin and T3 treatment reversed the activities. The antioxidant enzymes responded to the stress situation after 6-PTU treatment and photoperiod exposure by altering their activities. The study suggested an independent effect of T3 and melatonin on antioxidant defence mechanism in different physiological situations in fish.

  8. Free radicals, antioxidant defense systems, and schizophrenia.

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    Wu, Jing Qin; Kosten, Thomas R; Zhang, Xiang Yang

    2013-10-01

    The etiopathogenic mechanisms of schizophrenia are to date unknown, although several hypotheses have been suggested. Accumulating evidence suggests that excessive free radical production or oxidative stress may be involved in the pathophysiology of schizophrenia as evidenced by increased production of reactive oxygen or decreased antioxidant protection in schizophrenic patients. This review aims to summarize the basic molecular mechanisms of free radical metabolism, the impaired antioxidant defense system and membrane pathology in schizophrenia, their interrelationships with the characteristic clinical symptoms and the implications for antipsychotic treatments. In schizophrenia, there is accumulating evidence of altered antioxidant enzyme activities and increased levels of lipid peroxidation, as well as altered levels of plasma antioxidants. Moreover, free radical-mediated abnormalities may contribute to specific aspects of schizophrenic symptomatology and complications of its treatment with antipsychotic drugs, as well as the development of tardive dyskinesia (TD). Finally, the potential therapeutic strategies implicated by the accumulating data on oxidative stress mechanisms for the treatment of schizophrenia are discussed.

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

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    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.

  10. Molecular and structural antioxidant defenses against oxidative stress in animals.

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    Pamplona, Reinald; Costantini, David

    2011-10-01

    In this review, it is our aim 1) to describe the high diversity in molecular and structural antioxidant defenses against oxidative stress in animals, 2) to extend the traditional concept of antioxidant to other structural and functional factors affecting the "whole" organism, 3) to incorporate, when supportable by evidence, mechanisms into models of life-history trade-offs and maternal/epigenetic inheritance, 4) to highlight the importance of studying the biochemical integration of redox systems, and 5) to discuss the link between maximum life span and antioxidant defenses. The traditional concept of antioxidant defenses emphasizes the importance of the chemical nature of molecules with antioxidant properties. Research in the past 20 years shows that animals have also evolved a high diversity in structural defenses that should be incorporated in research on antioxidant responses to reactive species. Although there is a high diversity in antioxidant defenses, many of them are evolutionary conserved across animal taxa. In particular, enzymatic defenses and heat shock response mediated by proteins show a low degree of variation. Importantly, activation of an antioxidant response may be also energetically and nutrient demanding. So knowledge of antioxidant mechanisms could allow us to identify and to quantify any underlying costs, which can help explain life-history trade-offs. Moreover, the study of inheritance mechanisms of antioxidant mechanisms has clear potential to evaluate the contribution of epigenetic mechanisms to stress response phenotype variation.

  11. Defense Mechanisms: A Bibliography.

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    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.…

  12. Evaluation of hydroxyapatite-bioglass and hydroxyapatite-ethyl vinyl acetate composite extracts on antioxidant defense mechanism and genotoxicity: an in vitro study.

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    Arun, M; Silja, P K; Mohanan, P V

    2011-09-01

    Hydroxyapatite-bioglass (HA BG) and hydroxyapatite-ethyl vinyl acetate (HA EVA) are two composite materials that have been developed for bone substitution. Their activity on antioxidant defense mechanism and genotoxicity has not been investigated before. To further confirm its biocompatibility, the present study was undertaken to investigate the effect of HA BG and HA EVA on mice liver antioxidant mechanism along with chromosomal aberrations in human lymphocytes. Physiological saline extract of HA BG and HA EVA showed no adverse effect on liver antioxidant mechanism compared to the cyclophosphamide (CP)-induced toxicity on mice liver homogenate. The results were judged from the in vitro studies made on reduced glutathione, glutathione reductase and lipid peroxidation. These results were well supported by CP- and mytomycin C (MC)-induced genotoxicity studies on human lymphocytes in the presence and absence of a metabolic activator (S9). Hence, it was suggested that these tests could be considered for preliminary toxicological screening of materials intended for clinical applications ahead of in vivo animal model evaluation.

  13. 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.

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    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.

  14. Oxidative Stress and Antioxidant Defense

    OpenAIRE

    2012-01-01

    Abstract Reactive oxygen species (ROS) are produced by living organisms as a result of normal cellular metabolism and environmental factors, such as air pollutants or cigarette smoke. ROS are highly reactive molecules and can damage cell structures such as carbohydrates, nucleic acids, lipids, and proteins and alter their functions. The shift in the balance between oxidants and antioxidants in favor of oxidants is termed “oxidative stress.” Regulation of reducing and oxidizing (redox) state i...

  15. Protective effect of butyrate against ethanol-induced gastric ulcers in mice by promoting the anti-inflammatory, anti-oxidant and mucosal defense mechanisms.

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    Liu, Jiaming; Wang, Fangyan; Luo, Haihua; Liu, Aihua; Li, Kangxin; Li, Cui; Jiang, Yong

    2016-01-01

    Gastric ulcers (GUs) are a common type of peptic ulcer. Alcohol overdose is one of the main causes of GU, which is difficult to prevent. Although the protective effect of butyrate on inflammation-related diseases is well understood, its effect on GUs has not been reported. We investigated the protective effects of butyrate against ethanol-induced lesions to the gastric mucosa in mice and the underlying mechanisms. BALB/c mice were orally pretreated with butyrate for 30min prior to the establishment of the GU model by challenge with absolute ethanol. Ethanol administration produced apparent mucosal injuries with morphological and histological damage, whereas butyrate pretreatment reduced the gastric mucosal injuries in a dose-dependent manner. Butyrate pretreatment also significantly ameliorated contents of malondialdehyde (MDA) and carbonyl proteins, and decreased levels of IL-1β, TNF-α and IL-6. The Western blot results consistently demonstrated that butyrate pretreatment attenuated the phosphorylation of NF-κB p65, p38 MAPK and ERKs in the gastric tissues. Additionally, gastric wall mucus (GWM), a parameter reflecting mucosal defense, was clearly increased by butyrate pretreatment. Butyrate pretreatment protects the gastric mucosa against ethanol-induced lesions by strengthening the mucosal defense and anti-oxidant and anti-inflammatory activities. As a necessary substance for the body, butyrate may be applied to the prevention and treatment of GUs.

  16. Antioxidant Defenses in the Brains of Bats during Hibernation.

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    Yin, Qiuyuan; Ge, Hanxiao; Liao, Chen-Chong; Liu, Di; Zhang, Shuyi; Pan, Yi-Hsuan

    2016-01-01

    Hibernation is a strategy used by some mammals to survive a cold winter. Small hibernating mammals, such as squirrels and hamsters, use species- and tissue-specific antioxidant defenses to cope with oxidative insults during hibernation. Little is known about antioxidant responses and their regulatory mechanisms in hibernating bats. We found that the total level of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the brain of each of the two distantly related hibernating bats M. ricketti and R. ferrumequinum at arousal was lower than that at torpid or active state. We also found that the levels of malondialdehyde (product of lipid peroxidation) of the two hibernating species of bats were significantly lower than those of non-hibernating bats R. leschenaultia and C. sphinx. This observation suggests that bats maintain a basal level of ROS/RNS that does no harm to the brain during hibernation. Results of Western blotting showed that hibernating bats expressed higher amounts of antioxidant proteins than non-hibernating bats and that M. ricketti bats upregulated the expression of some enzymes to overcome oxidative stresses, such as superoxide dismutase, glutathione reductase, and catalase. In contrast, R. ferrumequinum bats maintained a relatively high level of superoxide dismutase 2, glutathione reductase, and thioredoxin-2 throughout the three different states of hibernation cycles. The levels of glutathione (GSH) were higher in M. ricketti bats than in R. ferrumequinum bats and were significantly elevated in R. ferrumequinum bats after torpor. These data suggest that M. ricketti bats use mainly antioxidant enzymes and R. ferrumequinum bats rely on both enzymes and low molecular weight antioxidants (e.g., glutathione) to avoid oxidative stresses during arousal. Furthermore, Nrf2 and FOXOs play major roles in the regulation of antioxidant defenses in the brains of bats during hibernation. Our study revealed strategies used by bats against oxidative

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

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    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.

  18. 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.

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

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    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.

  20. Antioxidant defenses and metabolic depression. The hypothesis of preparation for oxidative stress in land snails.

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    Hermes-Lima, M; Storey, J M; Storey, K B

    1998-07-01

    The roles of enzymatic antioxidant defenses in the natural tolerance of environmental stresses that impose changes in oxygen availability and oxygen consumption on animals is discussed with a particular focus on the biochemistry of estivation and metabolic depression in pulmonate land snails. Despite reduced oxygen consumption and PO2 during estivation, which should also mean reduced production of oxyradicals, the activities of antioxidant enzymes, such as superoxide dismutase and catalase, increased in 30 day-estivating snails. This appears to be an adaptation that allows the snails to deal with oxidative stress that takes place during arousal when PO2 and oxygen consumption rise rapidly. Indeed, oxidative stress was indicated by increased levels of lipid peroxidation damage products accumulating in hepatopancreas within minutes after arousal was initiated. The various metabolic sites responsible for free radical generation during arousal are still unknown but it seems unlikely that the enzyme xanthine oxidase plays any substantial role in this despite being implicated in oxidative stress in mammalian models of ischemia/reperfusion. We propose that the activation of antioxidant defenses in the organs of Otala lactea during estivation is a preparative mechanism against oxidative stress during arousal. Increased activities of antioxidant enzymes have also observed under other stress situations in which the actual production of oxyradicals should decrease. For example, antioxidant defenses are enhanced during anoxia exposure in garter snakes Thamnophis sirtalis parietalis (10 h at 5 degrees C) and leopard frogs Rana pipiens (30 h at 5 degrees C) and during freezing exposure (an ischemic condition due to plasma freezing) in T. sirtalis parietalis and wood frogs Rana sylvatica. It seems that enhancement of antioxidant enzymes during either anoxia or freezing is used as a preparatory mechanism to deal with a physiological oxidative stress that occurs rapidly within the

  1. Concepts of oxidative stress and antioxidant defense in Crohn's disease.

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    Alzoghaibi, Mohammed A

    2013-10-21

    Oxygen free radical and lipid peroxides (oxidative stress) are highly reactive and represent very damaging compounds. Oxidative stress could be a major contributing factor to the tissue injury and fibrosis that characterize Crohn's disease. An imbalance between increased reactive oxygen species levels and decreased antioxidant defenses occurs in Crohn's patients. Decreased blood levels of vitamins C and E and decreased intestinal mucosal levels of CuZn superoxide dismutase, glutathione, vitamin A, C, E, and β-carotene have been reported for Crohn's patients. Increased levels of proinflammatory cytokines, such as interleukin-1 and -8 and tumor necrosis factor, have been detected in inflammatory bowel disease. Oxidative stress significantly increased the production of neutrophils, chemokines, and interleukin-8. These effects were inhibited by antioxidant vitamins and arachidonic acid metabolite inhibitors in human intestinal smooth muscle cells isolated from the bowels of Crohn's disease patients. The main pathological feature of Crohn's disease is an infiltration of polymorphonuclear neutrophils and mononuclear cells into the affected part of the intestine. Activated neutrophils produce noxious substances that cause inflammation and tissue injury. Due to the physiological and biochemical actions of reactive oxygen species and lipid peroxides, many of the clinical and pathophysiological features of Crohn's disease might be explained by an imbalance of increased reactive oxygen species and a net decrease of antioxidant molecules. This review describes the general concepts of free radical, lipid peroxide and antioxidant activities and eventually illustrates their interferences in the development of Crohn's strictures.

  2. Effect of zinc and polyphenols supplementation on antioxidative defense mechanisms and the frequency of microsatellite instability in chemically-induced mammary carcinogenesis in the rat.

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    Bobrowska-Korczak, Barbara; Skrajnowska, Dorota; Tokarz, Andrzej; Bialek, Slawomir; Jezierska, Ewelina

    2015-01-01

    The aim of the present study was to assess the effect of dietary supplementation (with zinc or zinc and polyphenolic compounds - resveratrol or genistein) on antioxidant enzymes (glutathione peroxidase - GPx, catalase - CAT and superoxide dismutase - SOD) and the frequency of microsatellite instability (MSI) in a widely used model of mammary carcinogenesis induced in the rat by treatment with 7,12-dimethyl-1,2-benz[a]anthracene (DMBA). The impact of selected compounds on the intensity of DMBA-induced carcinogenesis was also assessed. Sixty four Sprague-Dawley female rats were divided into study groups which, apart from the standard diet and DMBA, were treated with zinc, zinc and resveratrol or zinc and genistein via gavage for a period ranging from 40 days to 20 weeks of age. On the basis of the obtained results it can be said that synergistic reaction between Zn(II) and genistein causes a delay in cancer development as compared with the animals treated with DMBA but with no food supplementation. Supplementation with Zn(II) and polyphenolic compounds resulted in the occurrence of microsatellite instabilities in tumors. LOH (loss of heterozygosity) was found in tumor samples at microsatellite D1Mgh6 and D3Mgh9. DMBA treatment increased significantly the glutathione peroxidase activity whereas it had no effect on the SOD and CAT activities, as compared with control rats. Diet supplementation has an effect on the activity of selected antioxidant enzymes. Diet supplementation has an effect on the occurrence of microsatellite instabilities as well as on the intensity of the neoplastic process. The intensity of occurrence of microsatellite instabilities does not depend on the activity of selected antioxidant enzymes.

  3. Daily variations of the antioxidant defense system of the lithodid crab Lithodes santolla.

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    Schvezov, Natasha; Lovrich, Gustavo A; Tapella, Federico; Romero, M Carolina

    2013-04-01

    Several physiological processes can induce daily variations in aerobic metabolism. Lithodes santolla is a decapod crustacean of special concern since it is a sub-Antarctic species of commercial interest. The aim of this work was to study in L. santolla the daily variations in levels of enzymatic and non-enzymatic antioxidants, lipid peroxidation and protein oxidation, and haemolymphatic pH. Males of L. santolla of commercial size were randomly dissected every 4 h during a period of 24 h. Enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase and glutathione peroxidase were determined in samples of gills, muscle, hepatopancreas and haemolymph. Ascorbic acid, total glutathione, lipid peroxidation and protein oxidation were also determined in all tissues. Gills showed the highest enzymatic activity and hepatopancreas the highest concentration of non-enzymatic antioxidants. Maximum antioxidant activity was during the dark phase in gills and during the photophase in the haemolymph. Muscle showed significant daily variations, with peaks during the photophase and scotophase. Overall, an antioxidant protective mechanism is present in all tissues, where SOD and CAT represent the first line of defense. The defense mechanism in L. santolla seems to be more active during the dark phase, with slight differences among the analyzed tissues, indicating a higher metabolic rate.

  4. Antioxidant enzymatic defenses and oxidative damage in Dentex dentex fed on different dietary macronutrient levels.

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    Pérez-Jiménez, Amalia; Hidalgo, M Carmen; Morales, Amalia E; Arizcun, Marta; Abellán, Emilia; Cardenete, Gabriel

    2009-11-01

    A wide range of antioxidant mechanisms are present in fish maintaining an adequate "oxidative balance". When this balance tilts in favor of the oxidant agents "oxidative stress" arises with detrimental effects in molecules of great biological importance. Little has been reported about the influence of different dietary energy sources on antioxidant defenses in fish. The influence of different dietary macronutrient combinations on the key antioxidant enzyme activity, the oxidative damage to lipids and proteins and the possible modifications in the SOD isoenzymatic pattern were evaluated in liver, white muscle, heart and erythrocytes of common dentex (Dentex dentex). Four experimental diets with different protein:lipid:carbohydrate ratios (43/16/28; 43/24/4; 38/19/28 and 38/24/13) were formulated. In general, neither different dietary macronutrient levels nor the interaction among them induces substantial modifications in enzymatic antioxidant defense mechanisms. Two constitutive SOD isoforms, CuZn-SOD I and Mn-SOD, were detected in the tissues analyzed in all experimental groups, independently of diet formulation, but, a third SOD isoenzyme, CuZn-SOD II seems to be induced in white muscle by higher dietary protein levels. Densitometric analyses of western blotting membranes revealed higher CuZn-SOD expression in the heart of dentex fed on lower dietary protein levels, although these differences did not correlate with the SOD activity. Finally, a direct relation exists between the lipid or protein intake level and occurrence of oxidative damage in different tissue components.

  5. 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,…

  6. 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.

  7. 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.

  8. Potential Contribution of Antioxidant Mechanism in the Defensive Effect of Lycopene Against Partial Sciatic Nerve Ligation Induced Behavioral, Biochemical and Histopathological Modification in Wistar Rats.

    Science.gov (United States)

    Goel, R; Tyagi, N

    2016-12-01

    Neuropathic pain is a severe and unbearable condition which arises due to activation of peripheral nociceptors after tissue damage, neuropathic pain is caused from anomalous physiology of central or peripheral nervous system and it may not be related to the ongoing tissue damage or inflammation. Involvement of oxidative damage has been reported in the pathophysiology of neuropathic pain. The purpose of this study was to examine the effect of lycopene to quench the free radicals produced as a result of the increased oxidative stress in neuropathic pain. Neuropathic pain was induced in wistar rats by partial sciatic nerve ligation. The effect was evaluated by assessing various behavioral parameters (thermal hyperalgesia, cold hyperalgesia), biochemical parameters (lipid peroxidation, reduced glutathione, superoxide dismutase and catalase) as well as histopathological parameters in sciatic nerve. During the experiment group of 8 rats each was administered drugs once daily intraperitonealy (I.P.) and naïve groups, sham group and sciatic nerve ligated group were treated with vehicle for the duration of 14 days. Partial sciatic nerve ligation (PSNL) significantly caused thermal hyperalgesia, cold hyperalgesia and oxidative damage compared to normal and sham groups. Daily administration of lycopene (25 mg/kg, 50 mg/kg) and gabapentin (100 mg/kg) considerably reversed hyperalgesia, cold hyperalgesia and attenuated oxidative stress when compared to control group. There was significant histological improvement in the in the architecture of myelinated and unmyelinated fibers. The results indicated that free radical generation mechanism might be involved in PSNL induced behavior, biochemical and histopathological changes in wistar rats.

  9. Trichoderma harzianum enhances antioxidant defense of tomato seedlings and resistance to water deficit.

    Science.gov (United States)

    Mastouri, Fatemeh; Björkman, Thomas; Harman, Gary E

    2012-09-01

    Some plant-symbiotic strains of the genus Trichoderma colonize roots and induce profound changes in plant gene expression that lead to enhanced growth, especially under biotic and abiotic stresses. In this study, we tested the hypothesis that one of the protective mechanisms enhanced by T. harzianum T22 colonization is the antioxidant defense mechanism. Having established that strain T22 modulates the expression of the genes encoding antioxidant enzymes, the status of antioxidant defense of tomato seedlings in response to colonization by T22 and water deficit was investigated. Total ascorbate or glutathione levels were not affected by either stimuli, but under water deficit, antioxidant pools became more oxidized (lower ratios of reduced to oxidized forms), whereas colonized plants maintained redox state as high as or higher than unstressed and untreated plants. The enhanced redox state of colonized plants could be explained by their higher activity of ascorbate and glutathione-recycling enzymes, higher activity of superoxide dismutase, catalase, and ascorbate peroxidase, in both root and shoot throughout the experiment. Similar enzymes were induced in uncolonized plants in response to water-deficit stress but to a lower extent when compared with colonized plants. This orchestrated enhancement in activity of reactive oxygen species (ROS)-scavenging pathways in colonized plants in response to stress supports the hypothesis that enhanced resistance of colonized plants to water deficit is at least partly due to higher capacity to scavenge ROS and recycle oxidized ascorbate and glutathione, a mechanism that is expected to enhance tolerance to abiotic and biotic stresses.

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

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    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.

  11. Oxidative and antioxidative defense system in testicular torsion/detorsion

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    F A Elshaari

    2011-01-01

    Full Text Available Aim: The present study was aimed to assess the early effects of ischemia/reperfusion injury on the oxidants and anti-oxidant defense status in rat testicular tissue by measuring MDA, glucose-6-phosphte dehydrogenase activity and reduced glutathione levels in a designated time frame sequel to reperfusion. Animals were divided randomly into six groups (12 animals per group in the following order: Group I: Sham-operated control group (Cso without the application of the torsion. Group 2: Torsion-induced ischemia group (T30 m: Ischemia was induced through the torsion of spermatic cord for a period of 30 min. Group 3: One hour reperfusion group after detorsion (T30 mR1 h. Group 4: Twenty-four hour reperfusion group after detorsion (T30 mR24 h. Group 5: Forty-eight hours reperfusion group after detorsion (T30mR48h. Group 6: One week reperfusion group after detorsion (T30mR1wk. Results and Discussion: The oxidant-antioxidant system of the testicular tissue is altered during torsion as well as detorsion which results in the altered activities involved in the key enzyme of hexose monophosphate shunt pathway, glucose 6 phosphate dehydrogenase activity along with a reduction of glutathione (G.SH content. The increase in G6PDH activity during torsion and followed by an increase in detorsion indicates the tissue′s response to counter the oxidant stress caused by reduced blood supply. Continued exposure to such oxidant stressed physiological state of a tissue may lead to decreased capacity of the tissue to perform its physiological function such as testicular steroidogenesis and spermiogenesis shown in the present study.

  12. Melanogenesis and antioxidant defense system in normal human melanocytes cultured in the presence of chlorpromazine.

    Science.gov (United States)

    Otreba, Michał; Wrześniok, Dorota; Beberok, Artur; Rok, Jakub; Buszman, Ewa

    2015-02-01

    Chlorpromazine is used in the treatment of schizophrenia and psychotic disorders and belongs to phenothiazine class of neuroleptic drugs. It shows severe side effects such as extrapyramidal symptoms as well as ocular and skin disorders, but the mechanism is still not fully established. The aim of this study was to examine the effect of chlorpromazine on cell viability, melanogenesis and antioxidant defense system in normal human melanocytes. It has been demonstrated that chlorpromazine induces concentration dependent loss in cell viability. The value of EC(50) was calculated to be 2.53 μM. Chlorpromazine in lower concentrations (0.0001, 0.001 and 0.01 μM) increased the melanin and microphthalmia-associated transcription factor (MITF) content and tyrosinase activity, while changes of antioxidant enzymes activity were not observed. It suggests that long-term chlorpromazine therapy, even with low drug doses, may lead to hyperpigmentation disorders in skin and/or eye. The use of the analyzed drug in higher concentrations (0.1 and 1.0 μM) caused significant alterations of antioxidant enzymes activity in normal melanocytes, what may explain a potential role of chlorpromazine in the depletion of cellular antioxidant status leading to other adverse effects associated with the high-dose and/or long-term therapy.

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

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    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.

  14. 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.

  15. [Indices of lipid peroxidation and antioxidant defense system and prostanoid level in patients with uterine cancer].

    Science.gov (United States)

    Antipova, S V

    2000-10-01

    The state of peroxydal oxidation of lipids, system of antioxidant defense and content of prostanoids in patients with cancer of the corpus uteri were investigated. Syndrome of endogenous intoxication with lowering of antioxidant potential and dysbalance of cyclic nucleotides and prostaglandines was established. The severity of above-cited disorders increased significantly after operation and during conduction of radiotherapy. This demanded administration of antioxidant and detoxicational therapy in complex of preoperative preparation.

  16. Heavy Metal Stress and Some Mechanisms of Plant Defense Response

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    Abolghassem Emamverdian

    2015-01-01

    Full Text Available Unprecedented bioaccumulation and biomagnification of heavy metals (HMs in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS. This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs or metallothioneins (MTs metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants.

  17. A Comparative In Silico Study of the Antioxidant Defense Gene Repertoire of Distinct Lifestyle Trypanosomatid Species

    Science.gov (United States)

    Beltrame-Botelho, Ingrid Thaís; Talavera-López, Carlos; Andersson, Björn; Grisard, Edmundo Carlos; Stoco, Patricia Hermes

    2016-01-01

    Kinetoplastids are an ancestral group of protists that contains free-living species and parasites with distinct mechanisms in response to stress. Here, we compared genes involved in antioxidant defense (AD), proposing an evolution model among trypanosomatids. All genes were identified in Bodo saltans, suggesting that AD mechanisms have evolved prior to adaptation for parasitic lifestyles. While most of the monoxenous and dixenous parasites revealed minor differences from B. saltans, the endosymbiont-bearing species have an increased number of genes. The absence of these genes was mainly observed in the extracellular parasites of the genera Phytomonas and Trypanosoma. In trypanosomes, a distinction was observed between stercorarian and salivarian parasites, except for Trypanosoma rangeli. Our analyses indicate that the variability of AD among trypanosomatids at the genomic level is not solely due to the geographical isolation, being mainly related to specific adaptations of their distinct biological cycles within insect vectors and to a parasitism of a wide range of hosts. PMID:27840574

  18. Responses of antioxidant defenses to Cu and Zn stress in two aquatic fungi.

    Science.gov (United States)

    Azevedo, Maria-Manuel; Carvalho, Agostinho; Pascoal, Cláudia; Rodrigues, Fernando; Cássio, Fernanda

    2007-05-15

    Aquatic hyphomycetes are fungi that play a key role in plant litter decomposition in streams. Even though these fungi occur in metal-polluted streams, the mechanisms underlying their tolerance to metals are poorly documented. We addressed the effects of Zn and Cu in Varicosporium elodeae and Heliscus submersus by examining metal adsorption to cell walls, plasma membrane integrity and production of reactive oxygen species at metal concentrations inhibiting biomass production in 50% or 80%. The activity of the enzymes catalase, superoxide dismutase and glucose-6-phosphate dehydrogenase was measured to elucidate their role in coping with oxidative stress induced by metals at short- (14 h) and long- (8 days) term exposure. Results show that V. elodeae was more susceptible to the toxic effects induced by Cu and Zn than H. submersus, as indicated by more extensive inhibition of biomass production. Both metals, particularly Cu, induced oxidative stress in the two fungal species, as shown by the noticeable recovery of biomass production in the presence of an antioxidant agent. In both fungi, Cu induced a more severe disruption of plasma membrane integrity than Zn. Our studies on antioxidant defenses showed that catalase had a greater role alleviating stress induced by Zn and Cu than superoxide dismutase. Chronic metal stress also stimulated the production of NADPH, via the pentose phosphate pathway by increasing the activity of glucose-6-phosphate dehydrogenase. Our results suggest that the tolerance of aquatic hyphomycetes to Cu and Zn is associated with the ability of these fungi to initiate an efficient antioxidant defense system.

  19. INFLUENCE OF CHRONIC EXERCISE ON RED CELL ANTIOXIDANT DEFENSE, PLASMA MALONDIALDEHYDE AND TOTAL ANTIOXIDANT CAPACITY IN HYPERCHOLESTEROLEMIC RABBITS

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    Mohsen Alipour

    2006-12-01

    Full Text Available Despite the knowledge on the antiatherogenic effects of exercise, the mechanism by which exercise reduces atherogenic risk remains unknown. In this study, we investigated the hypothesis that chronic exercise-induced oxidative stress may increase plasma total antioxidant capacity and antioxidant defense in the red cells. For 8 weeks, 60 male Dutch rabbits were fed rabbit chow with or without the addition of 2% cholesterol. The animals were further divided into rest and exercise groups (n = 15 for each group. Animals in exercise groups ran on a rodent treadmill at 15 m/min for 10 to 60 minutes gradually for 5 days per week for a total of 8 weeks. At the end of experiments, blood samples were collected and glutathione peroxidase (GPX, superoxide dismutase (SOD, and catalase (CAT activities were determined in red blood cells. Total antioxidant capacity (TAC, malondialdehyde (MDA and total thiol (T-SH levels were measured in plasma. Thoracic aorta and carotid arteries were isolated for histological examination to evaluate atherosclerosis. Eight weeks of chronic exercise reduced atherogenic diet-induced atherosclerotic lesions in all the arteries studied, along with positive changes in cholesterol profile, especially increase of serum HDL-C level. Plasma MDA, TAC and T-SH concentrations were enhanced by exercise in both control and hypercholesterolemic diet groups. Erythrocyte catalase activity was significantly increased by chronic exercise (p < 0.05, whereas total SOD activity rose with exercise only in the control group. Surprisingly, GPX activity was significantly reduced (P < 0.05 in response to exercise in the control group and also in the high cholesterol diet group. Exercise is a useful tool for the prevention and regression of atherosclerosis which is evident by our findings of the enhancement of plasma TAC and positive change in serum cholesterol profile. However, the effect of exercise on red cell antioxidant activities is limited in the

  20. 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.

  1. Modulation of antioxidant defense by Alpinia galanga and Curcuma aromatica extracts correlates with their inhibition of UVA-induced melanogenesis.

    Science.gov (United States)

    Panich, Uraiwan; Kongtaphan, Kamolratana; Onkoksoong, Tassanee; Jaemsak, Kannika; Phadungrakwittaya, Rattana; Thaworn, Athiwat; Akarasereenont, Pravit; Wongkajornsilp, Adisak

    2010-04-01

    Ultraviolet A (UVA) irradiation is suggested to contribute to melanogenesis through promoting cellular oxidative stress and impairing antioxidant defenses. An overproduction of melanin can be associated with melanoma skin cancer and hyperpigmentation. Therefore, developing effective antimelanogenic agents is of importance. Alpinia galanga (AG) and Curcuma aromatica (CA) are traditional medicinal plants widely used for skin problems. Hence, this study investigated the antimelanogenic effects of AG and CA extracts (3.8-30 microg/ml) by assessing tyrosinase activity, tyrosinase mRNA levels, and melanin content in human melanoma cells (G361) exposed to UVA. The roles in protecting against melanogenesis were examined by evaluating their inhibitory effects on UVA-induced cellular oxidative stress and modulation of antioxidant defenses including antioxidant enzymes, catalase (CAT) and glutathione peroxidase (GPx), and intracellular glutathione (GSH). In addition, possible active compounds accountable for biological activities of the extracts were identified by thin layer chromatography (TLC)-densitometric analysis. Our study demonstrated that UVA (8 J/cm(2)) induced both tyrosinase activity and mRNA levels and UVA (16 J/cm(2))-mediated melanin production were suppressed by the AG or CA extracts at noncytotoxic concentrations. Both extracts were able to protect against UVA-induced cellular oxidant formation and depletion of CAT and GPx activities and GSH content in a dose-dependent manner. Moreover, TLC-densitometric analysis detected the presence of eugenol and curcuminoids in AG and CA, respectively. This is the first report representing promising findings on AG and CA extract-derived antityrosinase properties correlated with their antioxidant potential. Inhibiting cellular oxidative stress and improving antioxidant defenses might be the mechanisms by which the extracts yield the protective effects on UVA-dependent melanogenesis.

  2. Coordinated Actions of Glyoxalase and Antioxidant Defense Systems in Conferring Abiotic Stress Tolerance in Plants

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    Mirza Hasanuzzaman

    2017-01-01

    Full Text Available Being sessile organisms, plants are frequently exposed to various environmental stresses that cause several physiological disorders and even death. Oxidative stress is one of the common consequences of abiotic stress in plants, which is caused by excess generation of reactive oxygen species (ROS. Sometimes ROS production exceeds the capacity of antioxidant defense systems, which leads to oxidative stress. In line with ROS, plants also produce a high amount of methylglyoxal (MG, which is an α-oxoaldehyde compound, highly reactive, cytotoxic, and produced via different enzymatic and non-enzymatic reactions. This MG can impair cells or cell components and can even destroy DNA or cause mutation. Under stress conditions, MG concentration in plants can be increased 2- to 6-fold compared with normal conditions depending on the plant species. However, plants have a system developed to detoxify this MG consisting of two major enzymes: glyoxalase I (Gly I and glyoxalase II (Gly II, and hence known as the glyoxalase system. Recently, a novel glyoxalase enzyme, named glyoxalase III (Gly III, has been detected in plants, providing a shorter pathway for MG detoxification, which is also a signpost in the research of abiotic stress tolerance. Glutathione (GSH acts as a co-factor for this system. Therefore, this system not only detoxifies MG but also plays a role in maintaining GSH homeostasis and subsequent ROS detoxification. Upregulation of both Gly I and Gly II as well as their overexpression in plant species showed enhanced tolerance to various abiotic stresses including salinity, drought, metal toxicity, and extreme temperature. In the past few decades, a considerable amount of reports have indicated that both antioxidant defense and glyoxalase systems have strong interactions in conferring abiotic stress tolerance in plants through the detoxification of ROS and MG. In this review, we will focus on the mechanisms of these interactions and the coordinated

  3. Coordinated Actions of Glyoxalase and Antioxidant Defense Systems in Conferring Abiotic Stress Tolerance in Plants

    Science.gov (United States)

    Hasanuzzaman, Mirza; Nahar, Kamrun; Hossain, Md. Shahadat; Mahmud, Jubayer Al; Rahman, Anisur; Inafuku, Masashi; Oku, Hirosuke; Fujita, Masayuki

    2017-01-01

    Being sessile organisms, plants are frequently exposed to various environmental stresses that cause several physiological disorders and even death. Oxidative stress is one of the common consequences of abiotic stress in plants, which is caused by excess generation of reactive oxygen species (ROS). Sometimes ROS production exceeds the capacity of antioxidant defense systems, which leads to oxidative stress. In line with ROS, plants also produce a high amount of methylglyoxal (MG), which is an α-oxoaldehyde compound, highly reactive, cytotoxic, and produced via different enzymatic and non-enzymatic reactions. This MG can impair cells or cell components and can even destroy DNA or cause mutation. Under stress conditions, MG concentration in plants can be increased 2- to 6-fold compared with normal conditions depending on the plant species. However, plants have a system developed to detoxify this MG consisting of two major enzymes: glyoxalase I (Gly I) and glyoxalase II (Gly II), and hence known as the glyoxalase system. Recently, a novel glyoxalase enzyme, named glyoxalase III (Gly III), has been detected in plants, providing a shorter pathway for MG detoxification, which is also a signpost in the research of abiotic stress tolerance. Glutathione (GSH) acts as a co-factor for this system. Therefore, this system not only detoxifies MG but also plays a role in maintaining GSH homeostasis and subsequent ROS detoxification. Upregulation of both Gly I and Gly II as well as their overexpression in plant species showed enhanced tolerance to various abiotic stresses including salinity, drought, metal toxicity, and extreme temperature. In the past few decades, a considerable amount of reports have indicated that both antioxidant defense and glyoxalase systems have strong interactions in conferring abiotic stress tolerance in plants through the detoxification of ROS and MG. In this review, we will focus on the mechanisms of these interactions and the coordinated action of

  4. Long-term consumption of aspartame and brain antioxidant defense status.

    Science.gov (United States)

    Abhilash, M; Sauganth Paul, M V; Varghese, Mathews V; Nair, R Harikumaran

    2013-04-01

    The present study investigated the effect of long-term intake of aspartame, a widely used artificial sweetener, on antioxidant defense status in the rat brain. Male Wistar rats weighing 150-175 g were randomly divided into three groups as follows: The first group was given aspartame at a dose of 500 mg/kg body weight (b.w.); the second group was given aspartame at dose of 1,000 mg/kg b.w., respectively, in a total volume of 3 mL of water; and the control rats received 3 mL of distilled water. Oral intubations were done in the morning, daily for 180 days. The concentration of reduced glutathione (GSH) and the activity of glutathione reductase (GR) were significantly reduced in the brain of rats that had received the dose of 1,000 mg/kg b.w. of aspartame, whereas only a significant reduction in GSH concentration was observed in the 500-mg/kg b.w. aspartame-treated group. Histopathological examination revealed mild vascular congestion in the 1,000 mg/kg b.w. group of aspartame-treated rats. The results of this experiment indicate that long-term consumption of aspartame leads to an imbalance in the antioxidant/pro-oxidant status in the brain, mainly through the mechanism involving the glutathione-dependent system.

  5. Validity of Self-Report Measures of Defense Mechanisms

    Science.gov (United States)

    Mehlman; Slane

    1994-06-01

    The Life Style Index (LSI), the Defense Style Questionnaire (DSQ), the Defense Mechanisms Inventory (DMI), and the FIRO Coping Operations Preferences Enquiry (FIRO) were administered to 187 undergraduates in order to determine convergent and discriminant validity of self-report measures of defense mechanisms. A correlational analysis of the four scales resulted in low correlations among subscales measuring similar defense mechanisms. A factor analysis produced factors based on particular scales rather than identical or similar constructs. Results suggest that self-report measures may not be an effective method for assessing various ego defense strategies.

  6. Antioxidant Defense by Thioredoxin Can Occur Independently of Canonical Thiol-Disulfide Oxidoreductase Enzymatic Activity

    Directory of Open Access Journals (Sweden)

    Miryoung Song

    2016-03-01

    Full Text Available The thiol-disulfide oxidoreductase CXXC catalytic domain of thioredoxin contributes to antioxidant defense in phylogenetically diverse organisms. We find that although the oxidoreductase activity of thioredoxin-1 protects Salmonella enterica serovar Typhimurium from hydrogen peroxide in vitro, it does not appear to contribute to Salmonella’s antioxidant defenses in vivo. Nonetheless, thioredoxin-1 defends Salmonella from oxidative stress resulting from NADPH phagocyte oxidase macrophage expression during the innate immune response in mice. Thioredoxin-1 binds to the flexible linker, which connects the receiver and effector domains of SsrB, thereby keeping this response regulator in the soluble fraction. Thioredoxin-1, independently of thiol-disulfide exchange, activates intracellular SPI2 gene transcription required for Salmonella resistance to both reactive species generated by NADPH phagocyte oxidase and oxygen-independent lysosomal host defenses. These findings suggest that the horizontally acquired virulence determinant SsrB is regulated post-translationally by ancestrally present thioredoxin.

  7. Ginsan activated the antioxidant defense systems in irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jie Young; Son, Soo Jung; Ahn, Ji Yeon; Shim, Ji Young; Han, Young Soo; Jung, In Sung; Yun, Yeon Sook [KIRMS Daegu (Korea, Republic of)

    2003-07-01

    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 {gamma}-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 o{sub 2} to H{sub 2}O{sub 2}, catalase deactivating h-2O{sub 2} and reduced glutathion (GSH) detoxifying H{sub 2}O{sub 2} and other ROS> At the 5{sub th} 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.

  8. Involvement of an antioxidant defense system in the adaptive response to cadmium in maize seedlings (Zea mays L.).

    Science.gov (United States)

    Xu, Xianghua; Liu, Cuiying; Zhao, Xiaoyan; Li, Renying; Deng, Wenjing

    2014-11-01

    Chemical and biological analyses were used to investigate the growth response and antioxidant defense mechanism of maize seedlings (Zea mays L.) grown in soils with 0-100 mg kg(-1) Cd. Results showed that maize seedlings have strong abilities to accumulate and tolerate high concentrations of Cd. For soil with 50 mg kg(-1) Cd, the Cd contents in roots and shoots of maize seedlings are as large as 295.6 and 153.0 mg kg(-1) DW, respectively, without visible symptoms of toxicity. Lower soil Cd concentrations lead to a decrease in reduced glutathione (GSH) content in leaves of maize seedlings, whereas higher soil Cd concentrations resulted in an increase in the activities of superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase. Maize seedlings have strong capacities to adapt to low concentrations of Cd by consuming GSH and to develop an antioxidative enzyme system to defend against high-Cd stress.

  9. Antioxidant mechanisms in radiation injury and radioprotection

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, J.F.; Kumar, K.S.

    1988-01-01

    Oxygen is a very important factor in determining radiosensitivity because it enhances the damage to cellular components caused by ionizing radiation, although mechanisms involved in UV irradiation damage may overlap ionizing radiation effects. This paper emphasizes chemical protection against damage by ionizing radiation and predominantly against the effects of photons (and gamma radiation). It is possible that free radicals and their products induced by ionizing radiation can interact with reactive oxygen species formed during normal processes, such as superoxide and hydrogen peroxide produced by phagocytic cells or during enzymatic processes (xanthine oxidase activity; enzymes involved in eicosanoid metabolism). Metals such as iron can promote free radical damage, whereas some bound metals have radioprotectant potential, e.g., metallothionein and ceruloplasmin. There is increasing evidence that maintenance of the proper oxidation-reduction state of cells by the interconversion of the peptide sulfhydryl glutathione (GSH), and its disulfide form (GSSG) is a factor in the modulation of cellular radiosensitivity. Other protein and nonprotein sulfhydryls may also play a role both as targets of radiation damage and as protectors. Other physiological antioxidants (vitamin E) and antioxidant enzymes are interrelated in their function of controlling oxidative processes. This review concentrates on the role of oxygen, glutathione, and antioxidant enzymes in radiosensitivity and how exogenous chemicals interact with these endogenous factors.

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

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    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.

  11. Antioxidant activity and mechanisms of action of natural compounds isolated from lichens: a systematic review.

    Science.gov (United States)

    White, Pollyanna A S; Oliveira, Rita C M; Oliveira, Aldeidia P; Serafini, Mairim R; Araújo, Adriano A S; Gelain, Daniel P; Moreira, Jose C F; Almeida, Jackson R G S; Quintans, Jullyana S S; Quintans-Junior, Lucindo J; Santos, Marcio R V

    2014-09-12

    Chronic diseases such as cancer, diabetes, neurodegenerative and cardiovascular diseases are characterized by an enhanced state of oxidative stress, which may result from the overproduction of reactive species and/or a decrease in antioxidant defenses. The search for new chemical entities with antioxidant profile is still thus an emerging field on ongoing interest. Due to the lack of reviews concerning the antioxidant activity of lichen-derived natural compounds, we performed a review of the antioxidant potential and mechanisms of action of natural compounds isolated from lichens. The search terms "lichens", "antioxidants" and "antioxidant response elements" were used to retrieve articles in LILACS, PubMed and Web of Science published until February 2014. From a total of 319 articles surveyed, 32 met the established inclusion and exclusion criteria. It was observed that the most common isolated compound studied was usnic acid, cited in 14 out of the 32 articles. The most often described antioxidant assays for the study of in vitro antioxidant activity were mainly DPPH, LPO and SOD. The most suggested mechanisms of action were scavenging of reactive species, enzymatic activation and inhibition of iNOS. Thus, compounds isolated from lichens are possible candidates for the management of oxidative stress, and may be useful in the treatment of chronic diseases.

  12. Antioxidant Property of Jobelyn as the Possible Mechanism Underlying

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    Solomon Umukoro

    2013-01-01

    Full Text Available   Introduction: Amnesia or loss of memory is the cardinal hallmark of Alzheimer’s disease (AD, a progressive neurodegenerative disorder associated with ageing process. Although, AD had been discovered over a century ago, drugs which could cure or halt the progression of the disease are yet to see the light of the day. However, there has been a growing interest in the use of phytomedicines with multipronged mechanisms of action that could target various aspects of the pathologies of AD. Jobelyn (JB is a potent antioxidant African polyherbal formulation with active components that have been acclaimed to show neuroprotection. T his investigation was carried out to evaluate whether JB has anti-amnesic and antioxidant activities.   Methods: The alteration of alternation behavior in the Y-maze paradigm was utilized as the test for memory function in mice. The effect of JB on a cetylcholinesterase (AChE activity, malondialdehyde (MDA level and the concentrations of glutathione (GSH in the frontal cortex and hippocampus were assessed in rats as means of providing insight into the mechanism underlying its anti-amnesic activity. The animals were given JB (1, 2.5 or 5mg/kg, i.p. daily for 7 days before the biochemical assays or test for memory functions were carried out.   Results: JB was found to produce a significant increase in the level of alternation behavior compared with the control, suggesting anti-amnesic activity. Also, JB reversed the memory impairment induced by scopolamine, which further indicates anti-amnesic property. Furthermore, JB demonstrated a significant inhibition of MDA formation in the frontal cortex and hippocampus of rats, indicating antioxidant property. In addition, it increased the defense armory of the brain tissues, as it significantly increased the concentrations of GSH in the frontal cortex and hippocampus of rats. However, JB did not demonstrate any inhibitory effect against AChE activity in the frontal cortex and

  13. Defense mechanisms in schizotypal, borderline, antisocial, and narcissistic personality disorders.

    Science.gov (United States)

    Perry, J Christopher; Presniak, Michelle D; Olson, Trevor R

    2013-01-01

    Numerous authors have theorized that defense mechanisms play a role in personality disorders. We reviewed theoretical writings and empirical studies about defenses in schizotypal, borderline, antisocial, and narcissistic personality disorders, developing hypotheses about these differential relationships. We then examined these hypotheses using dynamic interview data rated for defenses in a study of participants (n = 107) diagnosed with these four personality disorder types. Overall, the prevalence of immature defenses was substantial, and all four disorders fit within the broad borderline personality organization construct. Defenses predicted the most variance in borderline and the least variance in schizotypal personality disorder, suggesting that dynamic factors played the largest role in borderline and the least in schizotypal personality. Central to borderline personality were strong associations with major image-distorting defenses, primarily splitting of self and other's images, and the hysterical level defenses, dissociation and repression. Narcissistic and antisocial personality disorders shared minor image-distorting defenses, such as omnipotence or devaluation, while narcissistic also used splitting of self-images and antisocial used disavowal defenses like denial. Overall, differential relationships between specific defenses and personality disorder types were largely consistent with the literature, and consistent with the importance that the treatment literature ascribes to working with defenses.

  14. Activity of antioxidative defense enzymes in the blood of patients with liver echinococcosis

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    Lilić Aleksandar

    2007-01-01

    Full Text Available Background/Aim. Chronic echinococcocal disease is the parasite human disease caused by the penetration of larval (asexual stages of the canine tapeworm (Echinococcus granulosus in the liver of humans. After the penetration of the parasite, the host organism react by activating complement- depending immune response. The aim of this study was to elucidate the influence of larval form of Echinococcus granulosus in the liver on the activity of antioxidative defense enzymes in the blood of patients before and after the surgical intervention. Methods. We investigated the activity of antioxidative defense enzymes: copper/zinc containing superoxide dismutase (CuZn SOD, catalase (CAT, glutathione peroxidase (GSH-Px, glutathione reductase (GR and glutathione-S-transferase (GST in the blood of patients before and after the surgical intervention in respect to the controls, clinically healthy persons. Results. Our results showed that the activity of the GSH-Px was significantly decreased in the plasma of the patients with echinocococal disease before the surgery in respect to the controls. The activity of GST was significantly higher in the blood of the patients after the surgery in comparison to the controls. Conclusion. Chronic liver echinoccocal disease caused significant changes of some antioxidative defense enzymes, first of all Se-dependent enzyme GSH-Px, which could be a suitabile biomarker in the biochemical evaluation of the disease. This work represents a first comprehensive study of the activity of antioxidative defense enzymes in cronic liver echinococcocosis in the patients before and after the surgical intervention in respect to the clinically healthy persons.

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

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    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.

  16. 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...... polyphenol intake was observed. There was an increased oxidative stress response toward plasma proteins from food items rich in polyphenols and vitamin C and a decreased response when fruits and vegetables were omitted using a controlled diet. There also was a similar trend toward increased antioxidant...

  17. Nicotine impact on melanogenesis and antioxidant defense system in HEMn-DP melanocytes.

    Science.gov (United States)

    Delijewski, Marcin; Wrześniok, Dorota; Otręba, Michał; Beberok, Artur; Rok, Jakub; Buszman, Ewa

    2014-10-01

    Nicotine is a compound of tobacco plants and is responsible for addictive properties of tobacco which is used by about one billion of smokers all over the world. Recently, nicotine has drawn even more attention due to its presumed neuroprotective and antioxidant features as far as common use in various forms of smoking cessation therapies. It is suggested that nicotine may be accumulated in human tissues containing melanin. This may in turn influence biochemical processes in human cells producing melanin. The aim of this study was to examine the impact of nicotine on melanogenesis and antioxidant defense system in cultured normal human melanocytes (HEMn-DP). Nicotine induced concentration-dependent loss in melanocytes viability. The value of EC50 was determined to be 2.52 mM. Nicotine modulated melanin biosynthesis in normal human melanocytes. Significant changes in hydrogen peroxide content and cellular antioxidant enzymes: SOD, CAT, and GPx activities were stated in melanocytes exposed to nicotine, which indicates alterations of antioxidant defense system. The results obtained in vitro may explain a potential influence of nicotine on biochemical processes in melanocytes in vivo during long-term exposition to nicotine.

  18. Ferulic acid chronic treatment exerts antidepressant-like effect: role of antioxidant defense system.

    Science.gov (United States)

    Lenzi, Juliana; Rodrigues, Andre Felipe; Rós, Adriana de Sousa; de Castro, Amanda Blanski; de Castro, Bianca Blanski; de Lima, Daniela Delwing; Magro, Débora Delwing Dal; Zeni, Ana Lúcia Bertarello

    2015-12-01

    Oxidative stress has been claimed a place in pathophysiology of depression; however, the details of the neurobiology of this condition remains incompletely understood. Recently, treatments employing antioxidants have been thoroughly researched. Ferulic acid (FA) is a phenolic compound with antioxidant and antidepressant-like effects. Herein, we investigated the involvement of the antioxidant activity of chronic oral FA treatment in its antidepressant-like effect using the tail suspension test (TST) and the forced swimming test (FST) in mice. The modulation of antioxidant system in blood, hippocampus and cerebral cortex was assessed after stress induction through TST and FST. Our results show that FA at the dose of 1 mg/kg has antidepressant-like effect without affecting locomotor activity. The stress induced by despair tests was able to decrease significantly the activities of superoxide dismutase (SOD) in the blood, catalase (CAT) in the blood and cerebral cortex and glutathione peroxidase (GSH-Px) in the cerebral cortex. Thiobarbituric acid-reactive substances (TBA-RS) levels were increased significantly in the cerebral cortex. Furthermore, the results show that FA was capable to increase SOD, CAT and GSH-Px activities and decrease TBA-RS levels in the blood, hippocampus and cerebral cortex. These findings demonstrated that FA treatment in low doses is capable to exert antidepressant-like effect with the involvement of the antioxidant defense system modulation.

  19. 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

  20. Polyphenol Oxidase as a Biochemical Seed Defense Mechanism

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    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.

  1. TO ASSESS THE MAGNITUDE OF OXIDATIVE STRESS AND ANTIOXIDANT DEFENSE IN PREECLAMPSIA

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    Richa Pramod Priyamvada

    2016-07-01

    Full Text Available Preeclampsia is a multifactorial disease. Recent studies show that free radical induced endothelial injury may be a factor in pathogenesis of preeclampsia and that a biochemical imbalance occurs with an increase of oxidative stress, lipoperoxidation and deficient antioxidants. AIMS AND OBJECTIVES To evaluate parameters of oxidative stress and antioxidant defense in preeclampsia and thereby find any aetiological correlation. MATERIALS AND METHODS Study was carried on pregnant and non-pregnant women placed in four groups. This study was done to assess Malondialdehyde (MDA, as marker of oxidative stress and Total Antioxidant Capacity (TAC measured by Ferric Reducing Ability of Plasma (FRAP in normal pregnancy and preeclampsia and comparing with non-pregnant females. RESULTS Study shows rise in MDA level highest in severe preeclampsia (192.8 followed by mild preeclampsia (151.8 than in normal pregnancy (105.9, and non-pregnant (95.8 showing significant increase in levels of MDA (p<0.0001 in preeclamptic patients. TAC measured by FRAP significantly highest in severe preeclampsia (1725.6 followed by mild preeclampsia (1507 than in normal pregnancy (1203.3 and although there was increase in TAC in normal pregnant compared to non-pregnant (1173.7, increase was statistically insignificant. CONCLUSION Preeclampsia shows markedly increased oxidative stress as evidenced by significantly increased levels of malondialdehyde. There was strong correlation between total antioxidant capacity with severity of preeclampsia.

  2. Biotransformation and nitroglycerin-induced effects on antioxidative defense system in rat erythrocytes and reticulocytes.

    Science.gov (United States)

    Marković, Snežana D; Dorđević, Nataša Z; Curčić, Milena G; Stajn, Andraš S; Spasić, Mihajlo B

    2014-01-01

    The effects of nitroglycerin (glyceryl trinitrate - GTN) are mediated by liberated nitric oxide (NO) and formed reactive nitrogen species, which induces oxidative stress during biotransformation in red blood cells (RBCs). The aim of this study was to evaluate effects of GTN on antioxidative defense system (AOS) in rat erythrocytes (without) and reticulocytes (with functional mitochondria). Rat erythrocyte and reticulocyte-rich RBC suspensions were aerobically incubated (2 h, 37°C) without (control) or in the presence of different concentrations of GTN (0.1-1.5 mM). After incubation, concentrations of non-enzymatic components of AOS, activities of antioxidative enzymes and oxidative pentose phosphate (OPP) pathway activity were followed in RBC suspensions. In rat reticulocytes, GTN decreased the activity of mitochondrial MnSOD and increased the activity of CuZnSOD. In rat RBCs, GTN induced increase of Vit E concentration (at high doses), but decreased glutathione content and activities of all glutathione-dependent antioxidative enzymes; the OPP pathway activity significantly increased. GTN biotransformation and induction of oxidative stress were followed by general disbalance of antioxidative capacities in both kinds of RBCs. We suggest that oxidative stress, MnSOD inhibition and depletion of glutathione pool in response to GTN treatment lead to decreased bioavailability of NO after GTN biotransformation in rat reticulocytes.

  3. Relationships between coping strategies and defense mechanisms in sport performance.

    Science.gov (United States)

    Nicolas, Michel; Jebrane, Ahmed

    2008-12-01

    In an exploratory study, the relationships between two major concepts in psychological adjustment, coping strategies, and defense mechanisms were investigated. Sport competition is an example of a real-world context in which people's responses to stressful situations can be investigated. The extent to which participants reported different uses of coping strategies and defense mechanisms was assessed in terms of performance. 26 elite kayakers were classified into one of two groups, depending on the discrepancy between their standard performance and their performance in competition. Correlations were found among the coping strategies of seeking social support, positive reappraisal/planful problem solving, and mature defenses and between the coping strategy of distancing/avoidance and immature defenses. The results of multivariate and univariate analyses confirmed a significantly different use of coping strategies and defense mechanisms between the two performance groups. In light of these findings, certain recommendations in terms of methodology and application are warranted. Coping strategies and defense mechanisms should be studied to improve adjustment to sport performance.

  4. Anorexia of infection as a mechanism of host defense.

    Science.gov (United States)

    Murray, M J; Murray, A B

    1979-03-01

    The role of anorexia of infection as a mechanism of host defense was studied by force-feeding infected mice to a normal energy intake. Their mortality and survival times were then compared with those of infected mice feeding ad libitum. Mortality was increased and survival time shortened in force fed animals. Our observations suggest that anorexia, by reducing energy intake, has a significant role in the early defense of the host.

  5. Effects of diazinon on antioxidant defense system and lipid peroxidation in the liver of Cyprinus carpio (L.).

    Science.gov (United States)

    Oruc, Elif

    2011-11-01

    Diazinon is a widely used organophosphorus pesticide in agriculture and environmental health, hence its adverse effects on nontarget animals, especially on fish is to be determined. The present study therefore aimed at detecting the biochemical changes caused by diazinon. To accomplish this aim, we studied the effects of sublethal concentrations (0.0036, 0.018, and 0.036 ppb) of diazinon on acetylcholine esterase activity, antioxidant enzyme activities, and lipid peroxidation in the liver of Cyprinus carpio on days 5, 15, and 30 after the exposure. The results revealed that the antioxidant enzyme activities such as superoxide dismutase, glutathione peroxidase, and catalase were induced by diazinon exposure. In addition, the highest catalytic activity of glutathione S-transferase (GST) was obtained with 1-chloro-2, 4-dinitrobenzene (CDNB). GST activity toward 1,2-dichloro-4-nitrobenzene (DCNB) was also observed in the liver, yet it was relatively low as opposed to the other substrates tested. On the other hand, hepatic malondialdehyde level did not show any significant alteration except after the exposure on day 15. The exposure of low concentrations of diazinon to C. carpio can induce oxidative stress in liver; yet restoring susceptibility and adapting to oxidative stress are likely to occur when low level of oxidative stress is administered. Furthermore, no significant change was observed in hepatic lipid peroxidation after diazinon treatment indicating that liver tissue resisted to oxidative stress by enhancing their antioxidant mechanisms. The level of lipid peroxidation was assumed to be associated with the concentrations of diazinon and experimentation periods. The induction of glutathione S-transferase and antioxidant enzyme activities were also assumed to have resulted from the defense against the toxicity of diazinon.

  6. Defense mechanisms in patients with fibromyalgia and major depressive disorder

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    Tormod Landmark

    2008-12-01

    Full Text Available Background and objectives: Fibromyalgia (FM and depression has been suggested to share a common underlying etiology. Few studies have investigated the role of emotional regulation processes in FM compared to depressive disorders.The purpose of the current study was to explore the use of defense mechanisms in FM patients with and without comorbid lifetime depressive disorder (LDD, and to compare their use of defenses to healthy control subjects and patients with Major Depressive Disorder (MDD. Methods: A total of 91 participants were included (17 with FM and LDD, 25 with FM but not LDD, 24 with MDD, and 25 healthy controls. Depressive disorders were identified by using the Structured Clinical Interview for DSM Axis I disorders (SCID-I. All diagnosis of FM were confirmed to meet the American College of Rheumatology's criteria for FM. The Life Style Index (LSI was used to measure defense mechanisms. Results and Conclusions: Group comparisons indicated that MDD patients and FM patients with LDD made significantly more use of defenses than healthy controls, whereas FM patients without LDD made significantly less use of defenses than both MDD patients and FM patients with LDD, but did not differ from healthy controls. Follow up analyses indicated significant main effects for the defense mechanisms of regression, compensation and displacement. This study suggests that FM and depression do not share common risk factors in terms of restricted affects or avoidance of conflicted feelings.

  7. Metallothionein-mediated antioxidant defense system and its response to exercise training are impaired in human type 2 diabetes

    DEFF Research Database (Denmark)

    Scheede-Bergdahl, Celena; Penkowa, Milena; Hidalgo, Juan

    2005-01-01

    the MT-I+II-mediated antioxidant capacity and its response to exercise training in the skeletal muscle of patients with type 2 diabetes, biopsies and blood samples were taken from 13 matched subjects (type 2 diabetes n = 8, control subjects n = 5) both before and after 8 weeks of exercise training......-I+II in muscle and plasma, as well as the deficient MT-I+II response to exercise, indicate that this antioxidant defense is impaired. This study presents a novel candidate in the pathogenesis of complications related to oxidative stress in type 2 diabetes.......Oxidative stress is implicated in diabetes complications, during which endogenous antioxidant defenses have important pathophysiological consequences. To date, the significance of endogenous antioxidants such as metallothioneins I and II (MT-I+II) in type 2 diabetes remains unclear. To examine...

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

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    Blaya Carolina

    2006-01-01

    Full Text Available 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 Mini International Neuropsychiatric Interview, a structured psychiatric interview. We used ANOVA and discriminant analysis to assess differences between groups. RESULTS: Neurotic defense mechanisms discriminated controls from all patients except those with social anxiety. Immature defense mechanisms differentiated controls from all patients, as well as distinguished depressive patients from panic disorder and obsessive disorder patients. The discriminant analysis indicated that depressive patients are characterized by projection, panic disorder patients by sublimation and obsessive-compulsive patients by acting out. CONCLUSIONS: Depressive and anxious patients differ from other individuals in their use of defense mechanisms, and each diagnosis has a particular pattern. These findings could lead to the development of specific psychotherapeutic interventions.

  9. Compartmentalization of oxidative stress and antioxidant defense in the larval gut of Spodoptera littoralis.

    Science.gov (United States)

    Krishnan, Natraj; Sehnal, Frantisek

    2006-09-01

    Allelochemicals play important roles in the plant defense against herbivorous insects. They act as feeding deterrents, interfere with digestion and nutrient absorption, and cause production of potentially dangerous oxidative radicals. This study demonstrates that the distributions of oxidative radicals and of the antioxidant enzymes that eliminate them are compartmentalized in the digestive tract of Spodoptera littoralis larvae. Feeding on diets supplemented with the tannic acid (TA), alpha-solanine, and demissidine, respectively, did not affect the rate of food passage through the digestive tract of larvae but 1.25, 2.5, and 5% TA evoked a strong oxidative response. The amount of the superoxide anion in the foregut tissue and content increased up to 70-fold and the titer of total peroxides in the foregut content about 3-fold. This oxidative stress was associated with enhanced carbonyl content in the foregut tissue proteins, indicative of certain tissue deterioration. Extensive foregut damage was probably prevented by elevated activity of the glutathione S-transferase peroxidase. A complex antioxidant response was elicited in the midgut. The activities of superoxide dismutase and catalase increased significantly in the midgut tissue and content, and the activity of ascorbate peroxidase rose in the midgut tissue. The enzymes apparently eliminated oxidative radicals passing to midgut from the foregut with the food bolus and thereby prevented carbonylation of the midgut proteins. We postulate that the generation of oxidative radicals in the foregut and the induction of antioxidant defense in the midgut are controlled processes and that their compartmentalization is an important functional feature of the digestive tract. The glycoalkaloid alpha-solanine and the aglycone demissidine applied at 0.05 and 0.1% concentrations had no effect on any of the examined parameters.

  10. Modulation of antioxidant defense and immune response in zebra fish (Danio rerio) using dietary sodium propionate.

    Science.gov (United States)

    Safari, Roghieh; Hoseinifar, Seyed Hossein; Kavandi, Morteza

    2016-12-01

    The present study explores the effect of dietary sodium propionate on mucosal immune response and expression of antioxidant enzyme genes in zebra fish (Danio rerio). Six hundred healthy zebra fish (0.42 ± 0.06 g) supplied, randomly stocked in 12 aquariums and fed on basal diets supplemented with different levels of sodium propionate [0 (control), 5, 10 and 20 g kg(-1)] for 8 weeks. At the end of the feeding trial, mucosal immune parameters (TNF-α, IL-1β, Lyz), antioxidant enzyme (SOD, CAT) as well as heat shock protein 70 (HSP70) gene expression were measured. The results revealed feeding on sodium propionate significantly up-regulated inflammatory response genes (TNF-α, IL-1β, Lyz) in a dose-dependent manner (P fish fed the basal diet and deceased with elevation of sodium propionate levels in the diet. These results showed beneficial effects of dietary sodium propionate on mucosal immune response as well as the antioxidant defense of zebra fish.

  11. Inhibiting Glutathione Metabolism in Lung Lining Fluid as a Strategy to Augment Antioxidant Defense.

    Science.gov (United States)

    Joyce-Brady, Martin; Hiratake, Jun

    2011-07-01

    Glutathione is abundant in the lining fluid that bathes the gas exchange surface of the lung. On the one hand glutathione in this extracellular pool functions in antioxidant defense to protect cells and proteins in the alveolar space from oxidant injury; on the other hand, it functions as a source of cysteine to maintain cellular glutathione and protein synthesis. These seemingly opposing functions are regulated through metabolism by gamma-glutamyl transferase (GGT, EC 2.3.2.2). Even under normal physiologic conditions, lung lining fluid (LLF) contains a concentrated pool of GGT activity exceeding that of whole lung by about 7-fold and indicating increased turnover of glutathione at the epithelial surface of the lung. With oxidant stress LLF GGT activity is amplified even further as glutathione turnover is accelerated to meet the increased demands of cells for cysteine. Mouse models of GGT deficiency confirmed this biological role of LLF GGT activity and revealed the robust expansiveness and antioxidant capacity of the LLF glutathione pool in the absence of metabolism. Acivicin, an irreversible inhibitor of GGT, can be utilized to augment LLF fluid glutathione content in normal mice and novel GGT inhibitors have now been defined that provide advantages over acivicin. Inhibiting LLF GGT activity is a novel strategy to selectively augment the extracellular LLF glutathione pool. The enhanced antioxidant capacity can maintain lung epithelial cell integrity and barrier function under oxidant stress.

  12. 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.

  13. Antioxidant defense parameters as predictive biomarkers for fermentative capacity of active dried wine yeast.

    Science.gov (United States)

    Gamero-Sandemetrio, Esther; Gómez-Pastor, Rocío; Matallana, Emilia

    2014-08-01

    The production of active dried yeast (ADY) is a common practice in industry for the maintenance of yeast starters and as a means of long term storage. The process, however, causes multiple cell injuries, with oxidative damage being one of the most important stresses. Consequentially, dehydration tolerance is a highly appreciated property in yeast for ADY production. In this study we analyzed the cellular redox environment in three Saccharomyces cerevisiae wine strains, which show markedly different fermentative capacities after dehydration. To measure/quantify the effect of dehydration on the S. cerevisiae strains, we used: (i) fluorescent probes; (ii) antioxidant enzyme activities; (ii) intracellular damage; (iii) antioxidant metabolites; and (iv) gene expression, to select a minimal set of biochemical parameters capable of predicting desiccation tolerance in wine yeasts. Our results show that naturally enhanced antioxidant defenses prevent oxidative damage after wine yeast biomass dehydration and improve fermentative capacity. Based on these results we chose four easily assayable parameters/biomarkers for the selection of industrial yeast strains of interest for ADY production: trehalose and glutathione levels, and glutathione reductase and catalase enzymatic activities. Yeast strains selected in accordance with this process display high levels of trehalose, low levels of oxidized glutathione, a high induction of glutathione reductase activity, as well as a high basal level and sufficient induction of catalase activity, which are properties inherent in superior ADY strains.

  14. 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.

  15. Intracerebroventricular administration of N-acetylaspartic acid impairs antioxidant defenses and promotes protein oxidation in cerebral cortex of rats.

    Science.gov (United States)

    Pederzolli, Carolina Didonet; Rockenbach, Francieli Juliana; Zanin, Fernanda Rech; Henn, Nicoli Taiana; Romagna, Eline Coan; Sgaravatti, Angela M; Wyse, Angela T S; Wannmacher, Clóvis M D; Wajner, Moacir; de Mattos Dutra, Angela; Dutra-Filho, Carlos S

    2009-06-01

    N-acetylaspartic acid (NAA) is the biochemical hallmark of Canavan Disease, an inherited metabolic disease caused by deficiency of aspartoacylase activity. NAA is an immediate precursor for the enzyme-mediated biosynthesis of N-acetylaspartylglutamic acid (NAAG), whose concentration is also increased in urine and cerebrospinal fluid of patients affected by CD. This neurodegenerative disorder is clinically characterized by severe mental retardation, hypotonia and macrocephaly, and generalized tonic and clonic type seizures. Considering that the mechanisms of brain damage in this disease remain not fully understood, in the present study we investigated whether intracerebroventricular administration of NAA or NAAG elicits oxidative stress in cerebral cortex of 30-day-old rats. NAA significantly reduced total radical-trapping antioxidant potential, catalase and glucose 6-phosphate dehydrogenase activities, whereas protein carbonyl content and superoxide dismutase activity were significantly enhanced. Lipid peroxidation indices and glutathione peroxidase activity were not affected by NAA. In contrast, NAAG did not alter any of the oxidative stress parameters tested. Our results indicate that intracerebroventricular administration of NAA impairs antioxidant defenses and induces oxidative damage to proteins, which could be involved in the neurotoxicity of NAA accumulation in CD patients.

  16. Response of antioxidant defense system in copepodCalanus sinicus Brodsky exposed to CO2-acidified seawater

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dajuan; GUO Donghui; WANG Guizhong; LI Shaojing

    2016-01-01

    Marine zooplankton responds sensitively to elevated seawater CO2 concentration. However, the underlying physiological mechanisms have not been studied well. We therefore investigated the effects of elevated CO2 concentration (0.08%, 0.20%, 0.50% and 1.00%) on antioxidant defense components, as well as two detoxification enzymes ofCalanus sinicus (copepod). The results showed that glutathione peroxidase (GPx) activity exposed to CO2-acidified seawater was significantly stimulated while other antioxidant components, including glutathione-S-transferase (GST) activity, superoxide dismutase (SOD) activity decreased significantly with reduced glutathione (GSH) level and GSH/oxidized glutathione (GSSG) value. CO2-acidified seawater exhibited stimulatory effects on adenosine triphosphatase (ATPase) activity and acetylcholinesterase (AchE) activity was inhibited. Moreover, the results of principal component analysis indicated that 75.93% of the overall variance was explained by the first two principal components. The elevated CO2 concentration may affect the metabolism and survivals of copepods through impacts these enzymes activities. Further studies are needed to focus on the synergistic effects of elevated CO2 concentration and other environmental factors on copepods.

  17. Adaptation Mechanisms in the Evolution of Moss Defenses to Microbes

    Science.gov (United States)

    Ponce de León, Inés; Montesano, Marcos

    2017-01-01

    Bryophytes, including mosses, liverworts and hornworts are early land plants that have evolved key adaptation mechanisms to cope with abiotic stresses and microorganisms. Microbial symbioses facilitated plant colonization of land by enhancing nutrient uptake leading to improved plant growth and fitness. In addition, early land plants acquired novel defense mechanisms to protect plant tissues from pre-existing microbial pathogens. Due to its evolutionary stage linking unicellular green algae to vascular plants, the non-vascular moss Physcomitrella patens is an interesting organism to explore the adaptation mechanisms developed in the evolution of plant defenses to microbes. Cellular and biochemical approaches, gene expression profiles, and functional analysis of genes by targeted gene disruption have revealed that several defense mechanisms against microbial pathogens are conserved between mosses and flowering plants. P. patens perceives pathogen associated molecular patterns by plasma membrane receptor(s) and transduces the signal through a MAP kinase (MAPK) cascade leading to the activation of cell wall associated defenses and expression of genes that encode proteins with different roles in plant resistance. After pathogen assault, P. patens also activates the production of ROS, induces a HR-like reaction and increases levels of some hormones. Furthermore, alternative metabolic pathways are present in P. patens leading to the production of a distinct metabolic scenario than flowering plants that could contribute to defense. P. patens has acquired genes by horizontal transfer from prokaryotes and fungi, and some of them could represent adaptive benefits for resistance to biotic stress. In this review, the current knowledge related to the evolution of plant defense responses against pathogens will be discussed, focusing on the latest advances made in the model plant P. patens. PMID:28360923

  18. Adaptation Mechanisms in the Evolution of Moss Defenses to Microbes.

    Science.gov (United States)

    Ponce de León, Inés; Montesano, Marcos

    2017-01-01

    Bryophytes, including mosses, liverworts and hornworts are early land plants that have evolved key adaptation mechanisms to cope with abiotic stresses and microorganisms. Microbial symbioses facilitated plant colonization of land by enhancing nutrient uptake leading to improved plant growth and fitness. In addition, early land plants acquired novel defense mechanisms to protect plant tissues from pre-existing microbial pathogens. Due to its evolutionary stage linking unicellular green algae to vascular plants, the non-vascular moss Physcomitrella patens is an interesting organism to explore the adaptation mechanisms developed in the evolution of plant defenses to microbes. Cellular and biochemical approaches, gene expression profiles, and functional analysis of genes by targeted gene disruption have revealed that several defense mechanisms against microbial pathogens are conserved between mosses and flowering plants. P. patens perceives pathogen associated molecular patterns by plasma membrane receptor(s) and transduces the signal through a MAP kinase (MAPK) cascade leading to the activation of cell wall associated defenses and expression of genes that encode proteins with different roles in plant resistance. After pathogen assault, P. patens also activates the production of ROS, induces a HR-like reaction and increases levels of some hormones. Furthermore, alternative metabolic pathways are present in P. patens leading to the production of a distinct metabolic scenario than flowering plants that could contribute to defense. P. patens has acquired genes by horizontal transfer from prokaryotes and fungi, and some of them could represent adaptive benefits for resistance to biotic stress. In this review, the current knowledge related to the evolution of plant defense responses against pathogens will be discussed, focusing on the latest advances made in the model plant P. patens.

  19. 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.

  20. Mechanism and Defense on Malicious Code

    Institute of Scientific and Technical Information of China (English)

    WEN Wei-ping; QING Si-han

    2005-01-01

    With the explosive growth of network applications,the threat of the malicious code against network security becomes increasingly serious. In this paper we explore the mechanism of the malicious code by giving an attack model of the malicious code, and discuss the critical techniques of implementation and prevention against the malicious code. The remaining problems and emerging trends in this area are also addressed in the paper.

  1. Antioxidant defense in Plasmodium falciparum – data mining of the transcriptome

    Directory of Open Access Journals (Sweden)

    Ginsburg Hagai

    2004-07-01

    Full Text Available Abstract The intraerythrocytic malaria parasite is under constant oxidative stress originating both from endogenous and exogenous processes. The parasite is endowed with a complete network of enzymes and proteins that protect it from those threats, but also uses redox activities to regulate enzyme activities. In the present analysis, the transcription of the genes coding for the antioxidant defense elements are viewed in the time-frame of the intraerythrocytic cycle. Time-dependent transcription data were taken from the transcriptome of the human malaria parasite Plasmodium falciparum. Whereas for several processes the transcription of the many participating genes is coordinated, in the present case there are some outstanding deviations where gene products that utilize glutathione or thioredoxin are transcribed before the genes coding for elements that control the levels of those substrates are transcribed. Such insights may hint to novel, non-classical pathways that necessitate further investigations.

  2. The pentose phosphate pathway: an antioxidant defense and a crossroad in tumor cell fate.

    Science.gov (United States)

    Riganti, Chiara; Gazzano, Elena; Polimeni, Manuela; Aldieri, Elisabetta; Ghigo, Dario

    2012-08-01

    The pentose phosphate pathway, one of the main antioxidant cellular defense systems, has been related for a long time almost exclusively to its role as a provider of reducing power and ribose phosphate to the cell. In addition to this "traditional" correlation, in the past years multiple roles have emerged for this metabolic cascade, involving the cell cycle, apoptosis, differentiation, motility, angiogenesis, and the response to anti-tumor therapy. These findings make the pentose phosphate pathway a very interesting target in tumor cells. This review summarizes the latest discoveries relating the activity of the pentose phosphate pathway to various aspects of tumor metabolism, such as cell proliferation and death, tissue invasion, angiogenesis, and resistance to therapy, and discusses the possibility that drugs modulating the pathway could be used as potential tools in tumor therapy.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Effects of magnetic field on the antioxidant defense system of recirculation-cultured Chlorella vulgaris.

    Science.gov (United States)

    Wang, Hai-Ying; Zeng, Xiao-Bo; Guo, Si-Yuan; Li, Zong-Tao

    2008-01-01

    Little is known about the influence of magnetic fields (MF) on growth of microalgae such as Chlorella vulgaris, which has been consumed as health food for various nutritional and pharmacological effects. This preliminary study investigated whether static MF can modulate the antioxidant system in C. vulgaris by exposing the cells to static MF generated by dual yoke electromagnets with magnetic flux density of 10-50 mT for 12 h. After exposure to 10-35 mT for 12 h, the activity of superoxide dismutases and peroxidase increased significantly compared to control cells. However, a remarkable increase of catalase activity occurred at 45 and 50 mT. The lipid peroxidation of algae cells determined by production of thiobarbituric acid-reactive substances was much increased when exposed to 35, 45, and 50 mT of MF. The scavenging ability of 2,2-diphenyl-1-picrylhydrazyl radical was decreased markedly while there was no variation of total carotenoids content in C. vulgaris cells. Assay of specific growth rate in 72 h cultivation after MF exposure was also conducted. In groups after exposure to 10-35 mT of MF, specific growth rate was significantly increased. These results suggest that 10-35 mT of static MF exposure could promote the growth of C. vulgaris and regulate its antioxidant defense system to protect cells efficiently, which could possibly enhance the growth of C. vulgaris in industrialized cultivation by MF.

  9. The relationship between yield and the antioxidant defense system in tomatoes grown under heat stress.

    Science.gov (United States)

    Rainwater, D T; Gossett, D R; Millhollon, E P; Hanna, H Y; Banks, S W; Lucas, M C

    1996-11-01

    Four putative heat-tolerant tomato (Lycopersicum esculentum) cultivars (Tamasabro, Heat Wave, LHT-24, and Solar Set) and one putative heat-sensitive tomato cultivar (Floradade) were grown in the field under non-stress (average daily temperature of 26 degrees C) and heat-stress (average daily temperature of 34 degrees C) conditions. At anthesis, approximately five weeks after being transplanted to the field, leaf samples were collected for antioxidant analyses. Yield was determined by harvesting ripe fruit seven weeks after the collection of leaf samples. Heat stress resulted in a 79.1% decrease in yield for the heat-sensitive Floradade, while the fruit yield in the heat-tolerant cultivars Heat Wave, LHT-24, Solar Set, and Tamasabro was reduced 51.5%, 22.1%, 43.8%, and 34.8% respectively. When grown under heat stress, antioxidant activities were also greater in the heat-tolerant cultivars. Superoxide dismutase (SOD) activity increased up to 9-fold in the heat-tolerant cultivars but decreased 83.1% in the heat-sensitive Floradade. Catalase, peroxidase, and ascorbate peroxidase activity increased significantly in all cultivars. Only Heat Wave showed a significant increase in glutathione reductase in response to heat stress but all heat-tolerant cultivars exhibited significantly lower oxidized ascorbate/reduced ascorbate ratios, greater reduced glutathione/oxidized glutathione rations, and greater alpha-tocopherol concentrations compared to the heat-sensitive cultivar Floridade. These data indicate that the more heat-tolerant cultivars had an enhanced capacity for scavenging active oxygen species and a more active ascorbate-glutathione cycle and suggest a strong correlation between the ability to up-regulate the antioxidant defense system and the ability of tomatoes to produce greater yields when grown under heat stress.

  10. [Effect of ecopathogenic environmental factors on the system of antioxidant defense in different parts of the rat brain].

    Science.gov (United States)

    Severynovs'ka, O V; Hryhorova, M O; Zaĭchenko, O Iu; Rybal'chenko, V K

    2006-01-01

    Influence ofecopathogenic environmental (radiation-chemical) factors on activities of superoxiddismutase, catalase and total antioxidative activity (TAA) has been investigated in morphologically and functionally different parts of rat brain. It has been found that reaction of cells in brain cortex, subcortical structures and cerebellum to these factors in all cases is revealed through the antioxidant enzyme activities decrease in all studied brain structures but in various degrees. In brain cortex, which is characterized by higher metabolic level, functional complexity and specialization, the higher level of antioxidation defense is marked both in normal state and under the action of negative factors, that allows to maintain the prooxidation-antioxidation balance. Subcortical structures were more sensitive to the heavy metal impact. Compared to the action of single factors at chronic combined influence of radiation and heavy metals on the separate antioxidative enzymes a summation effect can be observed and at aforesaid joint impact on multi-component system of antioxidation defense a partial mutual evening-out of effects of radiation and chemical agents can be marked.

  11. Adaptive midlife defense mechanisms and late-life health.

    Science.gov (United States)

    Malone, Johanna C; Cohen, Shiri; Liu, Sabrina R; Vaillant, George E; Waldinger, Robert J

    2013-07-01

    A growing body of research suggests that personality characteristics relate to physical health; however, this relation ship has primarily been tested in cross-sectional studies that have not followed the participants into old age. The present study utilizes data from a 70-year longitudinal study to prospectively examine the relationship between the adaptive defense mechanisms in midlife and objectively assessed physical health in late life. In addition to examining the direct effect, we test whether social support mediates this relation ship. The sample consisted of 90 men who were followed for over seven decades beginning in late adolescence. Health ratings from medical records were made at three time points (ages 70, 75, and 80). Defense mechanisms were coded from narratives by trained independent raters (Vaillant, Bond, & Vaillant, 1986). Independent raters assessed social supports between ages 50 and 70. More adaptive defenses in midlife were associated with better physical health at all three time points in late life. These relationships were partially mediated by social support. Findings are consistent with the theory that defense maturity is important for building social relationships, which in turn contribute to better late-life physical health. Psychological interventions aimed at improving these domains may be beneficial for physical health.

  12. Antioxidant Properties and Cardioprotective Mechanism of Malaysian Propolis in Rats

    Science.gov (United States)

    Ahmed, Romana; Hossen, Md. Sakib; Ahmmed, Istiyak; Rumpa, Nur-E-Noushin; Sulaiman, Siti Amrah

    2017-01-01

    Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats (n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.

  13. 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.

  14. 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.

  15. 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.

  16. The Dual Role of Nrf2 in Nonalcoholic Fatty Liver Disease: Regulation of Antioxidant Defenses and Hepatic Lipid Metabolism

    Directory of Open Access Journals (Sweden)

    Sílvia S. Chambel

    2015-01-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is a progressive liver disease with ever-growing incidence in the industrialized world. It starts with the simple accumulation of lipids in the hepatocyte and can progress to the more severe nonalcoholic steatohepatitis (NASH, which is associated with inflammation, fibrosis, and cirrhosis. There is increasing awareness that reactive oxygen species and electrophiles are implicated in the pathogenesis of NASH. Transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2 is a positive regulator of the expression of a battery of genes involved in the protection against oxidative/electrophilic stress. In rodents, Nrf2 is also known to participate in hepatic fatty acid metabolism, as a negative regulator of genes that promote hepatosteatosis. We review relevant evidence in the literature that these two mechanisms may contribute to the protective role of Nrf2 in the development of hepatic steatosis and in the progression to steatohepatitis, particularly in young animals. We propose that age may be a key to explain contradictory findings in the literature. In summary, Nrf2 mediates the crosstalk between lipid metabolism and antioxidant defense mechanisms in experimental models of NAFLD, and the nutritional or pharmacological induction of Nrf2 represents a promising potential new strategy for its prevention and treatment.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. A temporal analysis of the relationships between social stress, humoral immune response and glutathione-related antioxidant defenses.

    Science.gov (United States)

    Gonçalves, Luciane; Dafre, Alcir Luiz; Carobrez, Sonia Gonçalves; Gasparotto, Odival Cezar

    2008-10-10

    The exposure to different kinds of stress impacts on the reactive oxygen species production with potential risk to the integrity of the tissues. Psychological or biological stress is responsible for a significant increase in the oxidative stress markers and also for activation of the antioxidant defense system. In this study, we analyzed the relationships between social stress, humoral immune response and glutathione-related antioxidant defenses. Groups of male Swiss mice were subjected to different lengths of social stress exposure (social confrontation) which varied from 1 up to 13 days. As a biological stressor, 10(9) sheep red blood cells (SRBC)/mL were injected by intraperitoneal route. As controls, animals not subjected to social stress and/or injected with vehicle solution were used. The serum samples and the cerebral cortex were collected at 4 h, 3, 5, 7, 9, 11, and 13 days after the end of social confrontation. The results indicated that the antioxidant enzymes activities were affected by psychological as well as by biological stressor. These alterations were dependent on the timing of stress exposure which resulted in a positive or in a negative correlation between the antibody titres to SRBC and antioxidant enzymes. We also discuss the possible role of SRBC injection in the modulation of the effects of psychosocial stress on antioxidant metabolism.

  2. OsHK3 is a crucial regulator of abscisic acid signaling involved in antioxidant defense in rice

    Institute of Scientific and Technical Information of China (English)

    Feng Wen; Tingting Qin; Yao Wang; Wen Dong; Aying Zhang; Mingpu Tan; Mingyi Jiang

    2015-01-01

    In this study, the role of the rice (Oryza sativa L.) histidine kinase OsHK3 in abscisic acid (ABA)‐induced antioxi-dant defense was investigated. Treatments with ABA, H2O2, and polyethylene glycol (PEG) induced the expression of OsHK3 in rice leaves, and H2O2 is required for ABA‐induced increase in the expression of OsHK3 under water stress. Subcel ular localization analysis showed that OsHK3 is located in the cytoplasm and the plasma membrane. The transient expres-sion analysis and the transient RNA interference test in rice protoplasts showed that OsHK3 is required for ABA‐induced upregulation in the expression of antioxidant enzymes genes and the activities of antioxidant enzymes. Further analysis showed that OsHK3 functions upstream of the calcium/calmodulin‐dependent protein kinase OsDMI3 and the mito-gen‐activated protein kinase OsMPK1 to regulate the activities of antioxidant enzymes in ABA signaling. Moreover, OsHK3 was also shown to regulate the expression of nicotinamide adenine dinucleotide phosphate oxidase genes, OsrbohB and OsrbohE, and the production of H2O2 in ABA signaling. Our data indicate that OsHK3 play an important role in the regulation of ABA‐induced antioxidant defense and in the feedback regula-tion of H2O2 production in ABA signaling.

  3. 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

  4. Cerebral Epiphyseal Proteins and Melatonin Modulate the Hepatic and Renal Antioxidant Defense of Rats

    Directory of Open Access Journals (Sweden)

    Vijay K. Bharti

    2011-01-01

    Full Text Available The cerebral epiphysis (pineal gland secrets melatonin and number of other proteins and peptides. It was thus hypothesized that antioxidant properties of epiphyseal proteins and melatonin could potentially benefit from exogenous therapies. In view of the therapeutic potential of these proteins, the present experiment was conducted to investigate the effect of buffalo epiphyseal proteins (BEP, at 100 μg/kg BW, i.p. and melatonin (MEL, at 10 mg/kg BW, i.p on changes in hepatic and renal antioxidant enzymes of adult female Wistar rats. Buffalo epiphyseal proteins significantly (P<.05 increased hepatic lipid peroxidation (LPO, superoxide dismutase (SOD, glutathione reductase (GR, glutathione peroxidase (GPx, reduced glutathione (GSH, and renal LPO, catalase (CAT, GR, GSH, GPx levels as compared to control animals. Similarly, MEL treatment significantly (P<.05 up-regulated hepatic SOD and GPx activity, whereas CAT, GR, GPx, and GSH levels in renal tissues were increased while SOD and LPO remained unaffected. Buffalo epiphyseal protein treatment produced greater effects on hepatic GPx and renal CAT and GSH levels than did MEL. These findings support the conclusion that buffalo epiphyseal proteins and melatonin activate a number of antioxidant mechanisms in hepatic and renal tissues.

  5. 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.

  6. Lycium chinensis Mill attenuates glutamate induced oxidative toxicity in PC12 cells by increasing antioxidant defense enzymes and down regulating ROS and Ca(2+) generation.

    Science.gov (United States)

    Olatunji, Opeyemi J; Chen, Hongxia; Zhou, Yifeng

    2016-03-11

    Lycium chinensis Mill is a famous traditional Chinese medicine which displays several medicinal activities including antioxidant and neuroprotective activities. However, the mechanism of action towards the neuroprotective action has not been fully elucidated. This work was aimed at investigating the neuroprotective effects of L. chinensis Mill against glutamate-induced oxidative neurotoxicity in PC12 cells. Oxidative cell death was induced with 5mM glutamate in PC12 cells. Cell viability, LDH release, intracellular Ca(2+) concentration, reactive oxygen species (ROS) accumulation, GSH-Px, CAT and SOD antioxidant enzyme levels were measured. Our results indicated that pretreatment of PC12 cells with L. chinensis Mill extracts markedly attenuated the loss of cell viability, the release of lactate dehydrogenase (LDH), Ca(2+) overload, ROS generation, and cell apoptosis induced by glutamate toxicity. Furthermore, L. chinensis Mill extracts also significantly increased the levels of innate antioxidant enzymes GSH-Px, SOD and CAT in glutamate-induced PC12 cells. Conclusively, our results provided substantial evidence that L. chinensis Mill protected PC12 cells against glutamate-induced cell death by attenuating ROS generation, Ca(2+) influx, and increased the antioxidant defense capacity of PC12 cells against oxidative stress damages, suggesting the possible potential of extracts from the plant as sources of bioactive molecules in the treatment of neurodegenerative disorders.

  7. Alleviation of alcoholic liver injury by betaine involves an enhancement of antioxidant defense via regulation of sulfur amino acid metabolism.

    Science.gov (United States)

    Jung, Young Suk; Kim, Sun Ju; Kwon, Do Young; Ahn, Chul Won; Kim, Young Soon; Choi, Dal Woong; Kim, Young Chul

    2013-12-01

    Previous studies suggested that the hepatoprotective activity of betaine is associated with its effects on sulfur amino acid metabolism. We examined the mechanism by which betaine prevents the progression of alcoholic liver injury and its therapeutic potential. Rats received a liquid ethanol diet for 6 wk. Ethanol consumption elevated serum triglyceride and TNFα levels, alanine aminotransferase and aspartate aminotransferase activities, and lipid accumulation in liver. The oxyradical scavenging capacity of liver was reduced, and expression of CD14, TNFα, COX-2, and iNOS mRNAs was induced markedly. These ethanol-induced changes were all inhibited effectively by betaine supplementation. Hepatic S-adenosylmethionine, cysteine, and glutathione levels, reduced in the ethanol-fed rats, were increased by betaine supplementation. Methionine adenosyltransferase and cystathionine γ-lyase were induced, but cysteine dioxygenase was down-regulated, which appeared to account for the increment in cysteine availability for glutathione synthesis in the rats supplemented with betaine. Betaine supplementation for the final 2 wk of ethanol intake resulted in a similar degree of hepatoprotection, revealing its potential therapeutic value in alcoholic liver. It is concluded that the protective effects of betaine against alcoholic liver injury may be attributed to the fortification of antioxidant defense via improvement of impaired sulfur amino acid metabolism.

  8. ABA Affects Brassinosteroid-Induced Antioxidant Defense via ZmMAP65-1a in Maize Plants.

    Science.gov (United States)

    Zhu, Yuan; Liu, Weijuan; Sheng, Yu; Zhang, Juan; Chiu, Tsanyu; Yan, Jingwei; Jiang, Mingyi; Tan, Mingpu; Zhang, Aying

    2015-07-01

    Brassinosteroids (BRs) and ABA co-ordinately regulate water deficit tolerance in maize leaves. ZmMAP65-1a, a maize microtubule-associated protein (MAP) which plays an essential role in BR-induced antioxidant defense, has been characterized previously. However, the interactions among BR, ABA and ZmMAP65-1a in water deficit tolerance remain unexplored. In this study, we demonstrated that ABA was required for BR-induced antioxidant defense via ZmMAP65-1a by using biochemical blocking and ABA biosynthetic mutants. The expression of ZmMAP65-1a in maize leaves and mesophyll protoplasts could be increased under polyethylene glycol- (PEG) stimulated water deficit and ABA treatments. Furthermore, the importance of ABA in the early pathway of BR-induced water deficit tolerance was demonstrated by limiting ABA availability. Blocking ABA biosynthesis biochemically or by a null mutation inhibited the downstream gene expression of ZmMAP65-1a and the activity of ZmMAPK5 in the pathway. It also affected the activities of BR-induced antioxidant defense-related enzymes, namely ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD) and NADPH oxidase. In addition, combining results from transiently overexpressed or silenced ZmMAP65-1a in mesophyll protoplasts, we discovered that ZmMAP65-1a mediated the ABA-induced gene expression and activities of APX and SOD. Surprisingly, silencing of ZmMAP65-1a in mesophyll protoplasts did not alter the gene expression of ZmCCaMK and vice versa in response to ABA. Taken together, our data indicate that water deficit-induced ABA is a key mediator in BR-induced antioxidant defense via ZmMAP65-1a in maize.

  9. Brassinosteroids make plant life easier under abiotic stresses mainly by modulating major components of antioxidant defense system

    Directory of Open Access Journals (Sweden)

    Bojjam V. Vardhini

    2015-01-01

    Full Text Available Various abiotic stress factors significantly contribute to major worldwide-losses in crop productivity by mainly impacting plant’s stress tolerance/adaptive capacity. The latter is largely governed by the efficiency of antioxidant defense system for the metabolism of elevated reactive oxygen species (ROS, caused by different abiotic stresses. Plant antioxidant defense system includes both enzymatic (such as superoxide dismutase, SOD, E.C. 1.15.1.1; catalase, CAT, E.C. 1.11.1.6; glutathione reductase, GR, E.C. 1.6.4.2; peroxidase, POD, E.C. 1.11.1.7; ascorbate peroxidase, APX, E.C. 1.11.1.11; guaiacol peroxidase, GPX, E.C. 1.11.1.7 and non-enzymatic (such as ascorbic acid, AsA; glutathione, GSH; tocopherols; phenolics, proline etc. components. Research reports on the status of various abiotic stresses and their impact on plant growth, development and productivity are extensive. However, least information is available on sustainable strategies for the mitigation of abiotic stress-mediated major consequences in plants. Brassinosteroids (BRs are a novel group of phytohormones with significant growth promoting nature. BRs are considered as growth regulators with pleiotropic effects, as they influence diverse physiological processes like growth, germination of seeds, rhizogenesis, senescence etc. and also confer abiotic stress resistance in plants. In the light of recent reports this paper: (a overviews major abiotic stresses and plant antioxidant defense system, (b introduces BRs and highlights their significance in general plant growth and development, and (c appraises recent literature available on BRs mediated modulation of various components of antioxidant defense system in plants under major abiotic stresses including metals/metalloids, drought, salinity, and temperature regimes. The outcome can be significant in devising future research in the current direction.

  10. 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.

  11. Effect of vitamin E and C supplements on antioxidant defense system in cardiovascular disease patients in Zahedan, southeast Iran.

    Science.gov (United States)

    Karajibani, Mansour; Hashemi, Mohammad; Montazerifar, Farzaneh; Dikshit, Madhurima

    2010-01-01

    Oxidative stress plays an important role in the pathogenesis of cardiovascular disease (CVD). Growing evidence suggest that antioxidant vitamins might reduce the risk of disease outcomes by their ability to scavenge free radicals. The aim of the present study was to evaluate the supplementation of vitamins E and C on oxidant and antioxidant status in CVD patients. We conducted a case-control study with vitamin E (400 IU/d) and vitamin C (500 mg/d) supplementation in 40 CVD patients for 2 mo. Antioxidant (enzymatic and non-enzymatic) and oxidant status were analyzed pre and post supplementation. In the initial stage the activity of both enzymatic and non-enzymatic antioxidants were lower, while the malondialdehyde (MDA) level was elevated (pvitamin E (83.7%), C (145.3%), total antioxidant capacity (TAC) (62.8%) and a significant decrease in MDA (40%) value were observed (pvitamins E and C reduced lipid peroxidation and strengthened the antioxidant defense system. Hence, there will be beneficial effects on the heart by reducing oxidative stress in CVD patients.

  12. 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.

  13. Effect of magnetic fields on antioxidative defense and fitness-related traits of Baculum extradentatum (insecta, phasmatodea).

    Science.gov (United States)

    Todorović, Dajana; Mirčić, Dejan; Ilijin, Larisa; Mrdaković, Marija; Vlahović, Milena; Prolić, Zlatko; Mataruga, Vesna Perić

    2012-04-01

    This study aimed to determine the effect of magnetic fields on the antioxidative defense and fitness-related traits of Baculum extradentatum. Following exposure to magnetic fields, antioxidative defense (superoxide dismutase (SOD), catalase (CAT) activities, and total glutathione (GSH) content) and fitness-related traits (egg mortality, development dynamics, and mass of nymphs) were monitored in nymphs. The experimental groups were: control (kept out of influence of the magnets), a group exposed to a constant magnetic field (CMF) of 50 mT, and a group exposed to an alternating magnetic field (AMF) of 50 Hz, 6 mT. We found increased SOD and CAT activities in animals exposed to constant and AMFs, whereas GSH activity was not influenced by experimental magnetic fields. No differences were found in egg mortality between control and experimental groups. Significant differences in the time of development between the control and the CMF group were observed, as well as between the CMF and the AMF group. No differences were found in the mass of the nymphs between the three experimental groups. In conclusion, CMF and AMF have the possibility to modulate the antioxidative defense and some of the fitness-related traits in B. extradentatum.

  14. 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.

  15. Oxidative Stress-Related Mechanisms and Antioxidant Therapy in Diabetic Retinopathy

    Directory of Open Access Journals (Sweden)

    Cheng Li

    2017-01-01

    Full Text Available Diabetic retinopathy (DR is one of the most common microvascular complications of diabetes and is the leading cause of blindness in young adults. Oxidative stress has been implicated as a critical cause of DR. Metabolic abnormalities induced by high-glucose levels are involved in the development of DR and appear to be influenced by oxidative stress. The imbalance between reactive oxygen species (ROS production and the antioxidant defense system activates several oxidative stress-related mechanisms that promote the pathogenesis of DR. The damage caused by oxidative stress persists for a considerable time, even after the blood glucose concentration has returned to a normal level. Animal experiments have proved that the use of antioxidants is a beneficial therapeutic strategy for the treatment of DR, but more data are required from clinical trials. The aims of this review are to highlight the improvements to our understanding of the oxidative stress-related mechanisms underlying the development of DR and provide a summary of the main antioxidant therapy strategies used to treat the disease.

  16. Oxidative Stress-Related Mechanisms and Antioxidant Therapy in Diabetic Retinopathy

    Science.gov (United States)

    Miao, Xiao

    2017-01-01

    Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes and is the leading cause of blindness in young adults. Oxidative stress has been implicated as a critical cause of DR. Metabolic abnormalities induced by high-glucose levels are involved in the development of DR and appear to be influenced by oxidative stress. The imbalance between reactive oxygen species (ROS) production and the antioxidant defense system activates several oxidative stress-related mechanisms that promote the pathogenesis of DR. The damage caused by oxidative stress persists for a considerable time, even after the blood glucose concentration has returned to a normal level. Animal experiments have proved that the use of antioxidants is a beneficial therapeutic strategy for the treatment of DR, but more data are required from clinical trials. The aims of this review are to highlight the improvements to our understanding of the oxidative stress-related mechanisms underlying the development of DR and provide a summary of the main antioxidant therapy strategies used to treat the disease.

  17. Paraoxonases-2 and -3 Are Important Defense Enzymes against Pseudomonas aeruginosa Virulence Factors due to Their Anti-Oxidative and Anti-Inflammatory Properties

    Directory of Open Access Journals (Sweden)

    Eva-Maria Schweikert

    2012-01-01

    Full Text Available The pathogen Pseudomonas aeruginosa causes serious damage in immunocompromised patients by secretion of various virulence factors, among them the quorum sensing N-(3-oxododecanoyl-L-homoserine lactone (3OC12 and the redox-active pyocyanin (PCN. Paraoxonase-2 (PON2 may protect against P. aeruginosa infections, as it efficiently inactivates 3OC12 and diminishes PCN-induced oxidative stress. This defense could be circumvented because 3OC12 mediates intracellular Ca2+-rise in host cells, which causes rapid inactivation and degradation of PON2. Importantly, we recently found that the PON2 paralogue PON3 prevents mitochondrial radical formation. Here we investigated its role as additional potential defense mechanism against P. aeruginosa infections. Our studies demonstrate that PON3 diminished PCN-induced oxidative stress. Moreover, it showed clear anti-inflammatory potential by protecting against NF-κB activation and IL-8 release. The latter similarly applied to PON2. Furthermore, we observed a Ca2+-mediated inactivation and degradation of PON3, again in accordance with previous findings for PON2. Our results suggest that the anti-oxidative and anti-inflammatory functions of PON2 and PON3 are an important part of our innate defense system against P. aeruginosa infections. Furthermore, we conclude that P. aeruginosa circumvents PON3 protection by the same pathway as for PON2. This may help identifying underlying mechanisms in order to sustain the protection afforded by these enzymes.

  18. 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.

  19. 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.

  20. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses.

    Science.gov (United States)

    Ni, Zhi-Jing; Hu, Kang-Di; Song, Chang-Bing; Ma, Run-Hui; Li, Zhi-Rong; Zheng, Ji-Lian; Fu, Liu-Hui; Wei, Zhao-Jun; Zhang, Hua

    2016-01-01

    Hydrogen sulfide (H2S) has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2 (∙-)) in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX) and catalase (CAT) and decreased those of lipoxygenase (LOX) in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation.

  1. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses

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    Zhi-Jing Ni

    2016-01-01

    Full Text Available Hydrogen sulfide (H2S has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA, hydrogen peroxide (H2O2, and superoxide anion (O2∙- in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX and catalase (CAT and decreased those of lipoxygenase (LOX in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation.

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

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    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.

  3. Antioxidants of Edible Mushrooms.

    Science.gov (United States)

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

    2015-10-27

    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.

  4. 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.

  5. Ω3 Supplementation and Intermittent Hypobaric Hypoxia Induce Cardioprotection Enhancing Antioxidant Mechanisms in Adult Rats

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    Emilio A. Herrera

    2015-02-01

    Full Text Available Intermittent hypobaric hypoxia (IH is linked with oxidative stress, impairing cardiac function. However, early IH also activate cardio-protective mechanisms. Omega 3 fatty acids (Ω3 induce cardioprotection by reducing infarct size and reinforcing antioxidant defenses. The aim of this work was to determine the combined effects of IH and Ω3 on cardiac function; oxidative balance and inflammatory state. Twenty-eight rats were randomly divided into four groups: normobaric normoxia (N; N + Ω3 (0.3 g·kg−1·day−1; IH; and IH + Ω3. IH was induced by 4 intercalate periods of hypoxia (4 days—normoxia (4 days in a hypobaric chamber during 32 days. At the end of the exposure, hearts were mounted in a Langendorff system and subjected to 30 min of ischemia followed by 120 min of reperfusion. In addition, we determined HIF-1α and ATP levels, as well as oxidative stress by malondialdehyde and nitrotyrosine quantification. Further, the expression of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase was determined. NF-kappaB and myeloperoxidase levels were assessed in the hearts. Relative to N hearts, IH improved left ventricular function (Left ventricular developed pressure: N; 21.8 ± 3.4 vs. IH; 42.8 ± 7.1 mmHg; p < 0.05; reduced oxidative stress (Malondialdehyde: N; 14.4 ± 1.8 vs. IH; 7.3 ± 2.1 μmol/mg prot.; p < 0.05; and increased antioxidant enzymes expression. Supplementation with Ω3 induces similar responses as IH group. Our findings suggest that both, IH and Ω3 in an independent manner, induce functional improvement by antioxidant and anti-inflammatory mechanisms, establishing cardio-protection.

  6. Antioxidant defense response induced by Trichoderma viride against Aspergillus niger Van Tieghem causing collar rot in groundnut (Arachis hypogaea L.).

    Science.gov (United States)

    Gajera, H P; Katakpara, Zinkal A; Patel, S V; Golakiya, B A

    2016-02-01

    The study was conducted to examine the antioxidant enzymes induced by Trichoderma viride JAU60 as initial defense response during invasion of rot pathogen Aspergillus niger Van Tieghem in five groundnut varieties under pot culture. Seed treatment of T. viride JAU60 reduced 51-58% collar rot disease incidence in different groundnut varieties under pathogen infected soil culture. The activities of the antioxidant enzymes, viz., superoxide dismutase (SOD, EC 1.15.1.1), guaiacol peroxidase (GPX, EC 1.11.1.7) and ascorbate peroxidase (APX, EC 1.11.1.11), elevated in response to pathogen infection, in higher rate by tolerant varieties (J-11 and GG-2) compared with susceptible (GAUG-10, GG-13, GG-20) and further induced by T. viride treatment. Trichoderma treatment remarkably increased the 2.3 fold SOD, 5 fold GPX and 2.5 fold APX activities during disease development in tolerant varieties and the same was found about 1.2, 1.5 and 2.0 folds, respectively, in susceptible varieties. Overall, T. viride JAU60 treated seedlings (T3) witnessed higher activities of SOD (1.5 fold), GPX (3.25 fold) and APX (1.25 fold) than pathogen treatment (T2) possibly suggest the induction of antioxidant defense response by Trichoderma bio-controller to combat oxidative burst produced by invading pathogen.

  7. Natural Defense Mechanisms of the Human Brain against Chronic Ischemia

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    A. V. Sergeev

    2015-01-01

    Full Text Available Objective: to study the structural bases of natural defense mechanisms of the human brain against chronic ischemia. Materials and methods. To accomplish this, histological, immunohistochemical (NSE, calbindin, NPY, p38 and morphometric examinations of intraoperative biopsy specimens were performed to determine the reorganization of excitatory and inhibitory neurons in the ischemic penumbra of the temporal cerebral cortex (CC. Morphometric analysis was made using the specially developed algorithms to verify neurons and their elements in the ImageJ 1.46 program. Results. The reduction in the total numerical density of neurons and synapses in chronic ischemia was ascertained to be accompanied by the compensatorily enhanced expression of NSE, calbindin, p38, and NPY in the remaining CC neurons. There were signs of hypertrophy of inhibitory CC interneurons and growth of their processes. In consequence, the impact of inhibitory CC interneurons on excitatory neurons was likely to enhance. Conclusion. In chronic ischemia, the human brain is anticipated to respond to damage to some cells via compensatory excitatory and inhibitory neuronal reorganization directed towards its natural defense against excitatory damage and towards better conditions for compensatory recovery of the structure and function of CC. 

  8. Reactive molecule species and antioxidative mechanisms in normal skin and skin aging.

    Science.gov (United States)

    Wölfle, Ute; Seelinger, Günter; Bauer, Georg; Meinke, Martina C; Lademann, Jürgen; Schempp, Christoph M

    2014-01-01

    Reactive oxygen and nitrogen species (ROS/RNS) which may exist as radicals or nonradicals, as well as reactive sulfur species and reactive carbon species, play a major role in aging processes and in carcinogenesis. These reactive molecule species (RMS), often referred to as 'free radicals' or oxidants, are partly by-products of the physiological metabolism. When RMS concentrations exceed a certain threshold, cell compartments and cells are injured and destroyed. Endogenous physiological mechanisms are able to neutralize RMS to some extent, thereby limiting damage. In the skin, however, pollutants and particularly UV irradiation are able to produce additional oxidants which overload the endogenous protection system and cause early aging, debilitation of immune functions, and skin cancer. The application of antioxidants from various sources in skin care products and food supplements is therefore widespread, with increasingly effective formulations being introduced. The harmful effects of RMS (aside from impaired structure and function of DNA, proteins, and lipids) are: interference with specific regulatory mechanisms and signaling pathways in cell metabolism, resulting in chronic inflammation, weakening of immune functions, and degradation of tissue. Important control mechanisms are: MAP-kinases, the aryl-hydrocarbon receptor (AhR), the antagonistic transcription factors nuclear factor-κB and Nrf2 (nuclear factor erythroid 2-related factor 2), and, especially important, the induction of matrix metalloproteinases which degrade dermal connective tissue. Recent research, however, has revealed that RMS and in particular ROS/RNS are apparently also produced by specific enzyme reactions in an evolutionarily adapted manner. They may fulfill important physiologic functions such as the activation of specific signaling chains in the cell metabolism, defense against infectious pathogens, and regulation of the immune system. Normal physiological conditions are characterized by

  9. Roles of sirtuins in the regulation of antioxidant defense and bioenergetic function of mitochondria under oxidative stress.

    Science.gov (United States)

    Wu, Y-T; Wu, S-B; Wei, Y-H

    2014-09-01

    In addition to serving as the power house of mammalian cells, mitochondria are crucial for the maintenance of cellular homeostasis in response to physiological or environmental changes. Several lines of evidence suggest that posttranslational modification (PTM) of proteins plays a pivotal role in the regulation of the bioenergetic function of mitochondria. Among them, reversible lysine acetylation of mitochondrial proteins has been established as one of the key mechanisms in cellular response to energy demand by modulating the flux of a number of key metabolic pathways. In this article, we focus on the role of Sirt3-mediated deacetylation in: (1) flexibility of energy metabolism, (2) activation of antioxidant defense, and (3) maintenance of cellular redox status in response to dietary challenge and oxidative stress. We suggest that oxidative stress-elicited down-regulation of Sirt3 plays a role in the pathophysiology of diabetes, cardiac hypotrophy, mitochondrial diseases, and age-related diseases. Besides, the physiological role of newly identified lysine acylation mediated by Sirt5 and its biochemical effects on oxidative metabolism are also discussed. Moreover, we have integrated the regulatory function of several protein kinases that are involved in the phosphorylation of mitochondrial enzymes during oxidative stress. Finally, the functional consequence of the synergistic regulation through diverse protein modifications is emphasized on the maintenance of the bioenergetic homeostasis and metabolic adaptation of the animal and human cells. Together, we have provided an updated review of PTM in mitochondrial biology and their implications in aging and human diseases through an intricate regulation of energy metabolism under oxidative stress.

  10. Study of General health, resiliency, and defense mechanisms in patients with migraine headache

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    Alireza Aghayusefi

    2013-06-01

    Full Text Available Background: Migraine is a neurological disease that the etiology, several factors affect its onset or its exacerbation. One of the factors affecting disease is psychological factors such as defense mechanisms, resiliency, and general health. This study assessed the relationship between general health, resiliency, and general defense mechanisms, and also predicts the general health of people with migraine headaches that have a high resiliency and use mature defense mechanisms. Material and Methods: 50 women with migraine headache in the city of Bushehr using defense mechanisms, resiliency, and general health questionnaires were studied. For statistical analysis, Pearson correlation and multiple regression tests were used by SPSS 17 software. Results: The results showed that most of the defense mechanisms of migraine sufferers are Immature and Neuroticism. There is significant negative correlation between the deterioration of general health and resiliency as well as the mature defense mechanism (p=0/003, and also there is a significant positive correlation between this deterioration with neuroticism (p=0/040 and immature defense mechanisms (p=0/041. On the other hand there is significant negative correlation between resiliencies with immature (p=0/009 and neuroticism defense mechanisms (p=0/04, and also with mature defense mechanism has a significant positive correlation (p=0/003. Also, as more people use the mature defense mechanism, their deterioration of general health will be reduced, but this relationship will be stronger with the presence of resiliency. So migraine people use the mature defense mechanisms with high resiliency will have more favorable general health (less deterioration of general health. Conclusion: This study showed that migraine patients use the mature defense mechanisms with high resiliency will have more favorable general health (less deterioration of general health.

  11. Cultivated sea lettuce is a multiorgan protector from oxidative and inflammatory stress by enhancing the endogenous antioxidant defense system.

    Science.gov (United States)

    Ratnayake, Ranjala; Liu, Yanxia; Paul, Valerie J; Luesch, Hendrik

    2013-09-01

    The health-promoting effects of seaweeds have been linked to antioxidant activity that may counteract cancer-causing oxidative stress-induced damage and inflammation. Although antioxidant activity is commonly associated with direct radical scavenging activity, an alternative way to increase the antioxidant status of a cell is to enhance the endogenous (phase II) defense system consisting of cytoprotective antioxidant enzymes, including NAD(P)H:quinone oxidoreductase 1 (NQO1). These enzymes are transcriptionally regulated by the antioxidant response element (ARE) via the transcription factor Nrf2. Extracts derived from cultivated Ulva sp., a green alga regarded as a marine vegetable (sea lettuce), potently activated the Nrf2-ARE pathway in IMR-32 neuroblastoma and LNCaP prostate cancer cells. RNA interference studies showed that Nrf2 and phosphoinositide 3-kinase (PI3K) are essential for the phase II response in IMR-32 cells. Activity-enriched fractions induced Nrf2 nuclear translocation and target gene transcription, and boosted the cellular glutathione level and therefore antioxidant status. A single-dose gavage feeding of Ulva-derived fractions increased Nqo1 transcript levels in various organs. Nqo1 induction spiked in different tissues, depending on the specific chemical composition of each administered fraction. We purified and characterized four ARE inducers in this extract, including loliolide (1), isololiolide (2), a megastigmen (3), and a novel chlorinated unsaturated aldehyde (4). The ARE-active fractions attenuated lipopolysaccharide-induced iNOS and Cox2 gene expression in macrophagic RAW264.7 cells, decreasing nitric oxide (NO) and prostaglandin E2 (PGE2) production, respectively. Nqo1 activity and NO production were abrogated in nrf2(-/-) mouse embryonic fibroblasts, providing a direct link between the induction of phase II response and anti-inflammatory activity.

  12. Effects of Dietary Lycopene Supplementation on Plasma Lipid Profile, Lipid Peroxidation and Antioxidant Defense System in Feedlot Bamei Lamb

    Science.gov (United States)

    Jiang, Hongqin; Wang, Zhenzhen; Ma, Yong; Qu, Yanghua; Lu, Xiaonan; Luo, Hailing

    2015-01-01

    Lycopene, a red non-provitamin A carotenoid, mainly presenting in tomato and tomato byproducts, has the highest antioxidant activity among carotenoids because of its high number of conjugated double bonds. The objective of this study was to investigate the effect of lycopene supplementation in the diet on plasma lipid profile, lipid peroxidation and antioxidant defense system in feedlot lamb. Twenty-eight Bamei male lambs (90 days old) were divided into four groups and fed a basal diet (LP0, 40:60 roughage: concentrate) or the basal diet supplemented with 50, 100, and 200 mg/kg lycopene. After 120 days of feeding, all lambs were slaughtered and sampled. Dietary lycopene supplementation significantly reduced the levels of plasma total cholesterol (p0.05). The levels of TG (p<0.001) and LDL-C (p<0.001) were decreased with the feeding time extension, and both showed a linear trend (p<0.01). Malondialdehyde level in plasma and liver decreased linearly with the increase of lycopene inclusion levels (p<0.01). Dietary lycopene intake linearly increased the plasma antioxidant vitamin E level (p<0.001), total antioxidant capacity (T-AOC, p<0.05), and activities of catalase (CAT, p<0.01), glutathione peroxidase (GSH-Px, p<0.05) and superoxide dismutase (SOD, p<0.05). The plasma T-AOC and activities of GSH-Px and SOD decreased with the extension of the feeding time. In liver, dietary lycopene inclusion showed similar antioxidant effects with respect to activities of CAT (p<0.05, linearly) and SOD (p<0.001, linearly). Therefore, it was concluded that lycopene supplementation improved the antioxidant status of the lamb and optimized the plasma lipid profile, the dosage of 200 mg lycopene/kg feed might be desirable for growing lambs to prevent environment stress and maintain normal physiological metabolism. PMID:26104400

  13. Resveratrol increases antioxidant defenses and decreases proinflammatory cytokines in hippocampal astrocyte cultures from newborn, adult and aged Wistar rats.

    Science.gov (United States)

    Bellaver, Bruna; Souza, Débora Guerini; Souza, Diogo Onofre; Quincozes-Santos, André

    2014-06-01

    Astrocytes are responsible for modulating neurotransmitter systems and synaptic information processing, ionic homeostasis, energy metabolism, maintenance of the blood-brain barrier, and antioxidant and inflammatory responses. Our group recently published a culture model of cortical astrocytes obtained from adult Wistar rats. In this study, we established an in vitro model for hippocampal astrocyte cultures from adult (90 days old) and aged (180 days old) Wistar rats. Resveratrol, a polyphenol found in grapes and red wine, exhibits antioxidant, anti-inflammatory, anti-aging and neuroprotective effects that modulate glial functions. Here, we evaluated the effects of resveratrol on GSH content, GS activity, TNF-α and IL-1β levels in hippocampal astrocytes from newborn, adult and aged Wistar rats. We observed a decrease in antioxidant defenses and an increase in the inflammatory response in hippocampal astrocytes from adult and aged rats compared to classical astrocyte cultures from newborn rats. Resveratrol prevented these effects. These findings reinforce the neuroprotective effects of resveratrol, which are mainly associated with antioxidant and anti-inflammatory activities.

  14. Antioxidant potential of yerba mate (Ilex paraguariensis St. Hil. extracts in Saccharomyces cerevisae deficient in oxidant defense genes

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    A. C. Piovezan-Borges

    Full Text Available Abstract Yerba-mate (Ilex paraguariensis St. Hil is mainly consumed as “chimarrão”, a hot drink highly appreciated in Brazil, Argentina, Paraguay and Uruguay. This study evaluated the antioxidant potential of aqueous extracts of I. paraguariensis precipitated with ethanol. The leaves were processed as for tea product (TM and oxidized (OX. The antioxidant potential was evaluated in cells of Saccharomyces cerevisiae deficient in antioxidant defense genes. Three strains evaluated were: a wild (EG and two mutants (ctt1Δ e ctt1Δsod1Δ. These strains were pre-treated with the yerba-mate extracts (TM e OX and submitted to oxidative stress induced by hydrogen peroxide. None of the extracts produced loss of cell viability. The extracts exerted antioxidant activity, protecting the strains (except sod1∆ctt1∆. The TM extract was more effective than OX. I. paraguariensis extracts showed a potential to be explored in the development of new products.

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

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    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.

  16. Host defense mechanism-based rational design of live vaccine.

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    Yo Han Jang

    Full Text Available Live attenuated vaccine (LAV, mimicking natural infection, provides an excellent protection against microbial infection. The development of LAV, however, still remains highly empirical and the rational design of clinically useful LAV is scarcely available. Apoptosis and caspase activation are general host antiviral responses in virus-infected cells. Utilizing these tightly regulated host defense mechanisms, we present a novel apoptosis-triggered attenuation of viral virulence as a rational design of live attenuated vaccine with desired levels of safety, efficacy, and productivity. Mutant influenza viruses carrying caspase recognition motifs in viral NP and the interferon-antagonist NS1 proteins were highly attenuated both in vitro and in vivo by caspase-mediated cleavage of those proteins in infected cells. Both viral replication and interferon-resistance were substantially reduced, resulting in a marked attenuation of virulence of the virus. Despite pronounced attenuation, the viruses demonstrated high growth phenotype in embryonated eggs at lower temperature, ensuring its productivity. A single dose vaccination with the mutant virus elicited high levels of systemic and mucosal antibody responses and provided complete protection against both homologous and heterologous lethal challenges in mouse model. While providing a practical means to generate seasonal or pandemic influenza live vaccines, the sensitization of viral proteins to pathogen-triggered apoptotic signals presents a potentially universal, mechanism-based rational design of live vaccines against many viral infections.

  17. Host defense mechanism-based rational design of live vaccine.

    Science.gov (United States)

    Jang, Yo Han; Byun, Young Ho; Lee, Kwang-Hee; Park, Eun-Sook; Lee, Yun Ha; Lee, Yoon-Jae; Lee, Jinhee; Kim, Kyun-Hwan; Seong, Baik Lin

    2013-01-01

    Live attenuated vaccine (LAV), mimicking natural infection, provides an excellent protection against microbial infection. The development of LAV, however, still remains highly empirical and the rational design of clinically useful LAV is scarcely available. Apoptosis and caspase activation are general host antiviral responses in virus-infected cells. Utilizing these tightly regulated host defense mechanisms, we present a novel apoptosis-triggered attenuation of viral virulence as a rational design of live attenuated vaccine with desired levels of safety, efficacy, and productivity. Mutant influenza viruses carrying caspase recognition motifs in viral NP and the interferon-antagonist NS1 proteins were highly attenuated both in vitro and in vivo by caspase-mediated cleavage of those proteins in infected cells. Both viral replication and interferon-resistance were substantially reduced, resulting in a marked attenuation of virulence of the virus. Despite pronounced attenuation, the viruses demonstrated high growth phenotype in embryonated eggs at lower temperature, ensuring its productivity. A single dose vaccination with the mutant virus elicited high levels of systemic and mucosal antibody responses and provided complete protection against both homologous and heterologous lethal challenges in mouse model. While providing a practical means to generate seasonal or pandemic influenza live vaccines, the sensitization of viral proteins to pathogen-triggered apoptotic signals presents a potentially universal, mechanism-based rational design of live vaccines against many viral infections.

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

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    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.

  19. Calcium supplementation improves Na+/K+ ratio, antioxidant defense and glyoxalase systems in salt-stressed rice seedlings

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    Anisur eRahman

    2016-05-01

    Full Text Available The present study investigates the regulatory role of exogenous calcium (Ca in developing salt stress tolerance in rice seedlings. Hydroponically grown 13-d-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 three 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-induced stress caused oxidative stress in rice seedlings through lipid peroxidation, loss of plasma membrane integrity, higher reactive oxygen species (ROS production and methylglyoxal (MG formation. The salt-stressed rice 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 rice 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.

  20. 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. PMID:27242816

  1. Antioxidants

    Science.gov (United States)

    Antioxidants are man-made or natural substances that may prevent or delay some types of cell damage. Antioxidants are found in many foods, including fruits and ... are also available as dietary supplements. Examples of antioxidants include Beta-carotene Lutein Lycopene Selenium Vitamin A ...

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

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    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.

  3. The 5'-AMP-Activated Protein Kinase (AMPK Is Involved in the Augmentation of Antioxidant Defenses in Cryopreserved Chicken Sperm.

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    Thi Mong Diep Nguyen

    Full Text Available Semen cryopreservation is a unique tool for the management of animal genetic diversity. However, the freeze-thaw process causes biochemical and physical alterations which make difficult the restoration of sperm energy-dependent functions needed for fertilization. 5'-AMP activated protein kinase (AMPK is a key sensor and regulator of intracellular energy metabolism. Mitochondria functions are known to be severely affected during sperm cryopreservation with deleterious oxidative and peroxidative effects leading to cell integrity and functions damages. The aim of this study was thus to examine the role of AMPK on the peroxidation/antioxidant enzymes defense system in frozen-thawed sperm and its consequences on sperm functions. Chicken semen was diluted in media supplemented with or without AMPK activators (AICAR or Metformin [MET] or inhibitor (Compound C [CC] and then cryopreserved. AMPKα phosphorylation, antioxidant enzymes activities, mitochondrial potential, ATP, citrate, viability, acrosome reaction ability (AR and various motility parameters were negatively affected by the freeze-thaw process while reactive oxygen species (ROS production, lipid peroxidation (LPO and lactate concentration were dramatically increased. AICAR partially restored superoxide dismutase (SOD, Glutathione Peroxidase (GPx and Glutathione Reductase (GR, increased ATP, citrate, and lactate concentration and subsequently decreased the ROS and LPO (malondialdehyde in frozen-thawed semen. Motility parameters were increased (i.e., + 23% for motility, + 34% for rapid sperm as well as AR (+ 100%. MET had similar effects as AICAR except that catalase activity was restored and that ATP and mitochondrial potential were further decreased. CC showed effects opposite to AICAR on SOD, ROS, LPO and AR and motility parameters. Taken together, our results strongly suggest that, upon freeze-thaw process, AMPK stimulated intracellular anti-oxidative defense enzymes through ATP regulation

  4. Effects of diets based on foods from conventional versus organic production on intake and excretion of flavonoids and markers of antioxidative defense in humans

    DEFF Research Database (Denmark)

    Grinder-Pedersen, Lisbeth; Rasmussen, Salka E.; Bügel, Susanne

    2003-01-01

    Different food production methods may result in differences in the content of secondary metabolites such as polyphenolic compounds. The present study compared conventionally (CPD) and organically produced (OPD) diets in a human crossover intervention study (n = 16) with respect to the intake...... both interventions. Most markers of antioxidative defense did not differ between the diets, but intake of OPD resulted in an increased protein oxidation and a decreased total plasma antioxidant capacity compared to baseline (P

  5. Molecular identification of three novel glutaredoxin genes that play important roles in antioxidant defense in Helicoverpa armigera.

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    Zhang, Song-Dou; Shen, Zhong-Jian; Liu, Xiao-Ming; Li, Zhen; Zhang, Qing-Wen; Liu, Xiao-Xia

    2016-08-01

    Glutaredoxins (Grxs), also known as thioltransferases, play key roles in maintaining intracellular redox balance and protecting cells from oxidative damage in plants and mammals. We tested whether Grxs play important roles in antioxidant defense in insects using the moth, Helicoverpa armigera. We obtained the full-length cDNA sequences of three novel Grx genes, named HaGrx, HaGrx3, and HaGrx5. Sequence analysis indicated that HaGrx shared a high amino acid identity (58%-78%) and a CPYC motif of conserved redox activity with homologues from other selected insect species. In contrast, HaGrx3 and HaGrx5 both shared a CGF(S/G) motif, a conserved catalytic domain, with other orthologous genes. Quantitative real-time PCR results revealed that HaGrx, HaGrx3, and HaGrx5 exhibited temporally- and spatially-dependent patterns of expression. The mRNA expression of HaGrx, HaGrx3, and HaGrx5 was induced by various temperature stresses and H2O2 treatments. We further investigated the knockdown of HaGrx, HaGrx3, and HaGrx5 in H. armigera larvae and found that most of the selected antioxidant genes were up regulated. However, Tpx was down regulated, and further interpretation of the complementary functions of these antioxidant genes is still required. We also determined the effect of HaGrx, HaGrx3, and HaGrx5 knockdown on antioxidant enzymatic activity and metabolite content. The enzymatic activities of SOD, CAT, and POD, and the metabolite contents of hydrogen peroxide, ascorbate, protein carbonyl, and total GSH increased after RNAi mediated knockdown of HaGrx, HaGrx3, and HaGrx5. These results supported our hypothesis that HaGrx, HaGrx3, and HaGrx5 play important roles in antioxidant defense of Helicoverpa armigera and provided a theoretical basis for further in-depth study of physiological function in the insect glutaredoxin family genes.

  6. Strain-Related Differences on Response of Liver and Kidney Antioxidant Defense System in Two Rat Strains Following Diazinon Exposure

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    Maryam Salehi

    2016-02-01

    Full Text Available Background Diazinon (DZN is one of the most organophosphates that widely used in agriculture and ectoparasiticide formulations. Its extensive use as an effective pesticide was associated with the environmental deleterious effects on biological systems. Objectives The aim of this study was to investigate the potency of DZN to affect serum biochemical parameters and the antioxidant defense system in the liver and kidney of two rat strains. Materials and Methods In this experimental study, 30 female Wistar and 30 female Norway rats were randomly divided into control and DZN groups. DZN group was divided into four subgroups: 25, 50, 100 and 200 mg/kg of DZN administered groups by i.p. injection. The parameters were evaluated after 24 hours. Results At higher doses of DZN, superoxide dismutase, catalase, glutathione S-transferase and lactate dehydrogenase activities and glutathione (GSH and malondialdehyde levels in liver and kidney of Wistar rats were higher than Norway rats. At these concentrations, DZN increased some serum biochemical indices such as liver enzymes activities and levels of urea, uric acid and creatinine in Wistar rat. Conclusions DZN at higher doses alters the oxidant-antioxidant balance in liver and kidney of both rat strains and induces oxidative stress, which is associated with a depletion of GSH and increased lipid peroxidation. However, Wistar rats are found to be more sensitive to the toxicity of DZN compared to Norway rats. In addition, the effect of DZN on liver antioxidant system was more than kidney.

  7. Effect of tacrolimus on the cauda epididymis in rats: analysis of epididymal biochemical markers or antioxidant defense enzymes.

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    Hisatomi, Akihiko; Sakuma, Shozo; Fujiwara, Michio; Seki, Jiro

    2008-01-14

    The effect of tacrolimus on epididymal biochemical markers was investigated following single daily subcutaneous doses of 1, 2 and 3 mg kg(-1) day(-1) for 2 weeks to male adult rats. The tacrolimus 2 and 3 mg kg(-1) day(-1) groups showed a significant and dose-dependent decrease in sperm count in the cauda epididymis. Among tissue levels of L-carnitine, alpha-glucosidase and acid phosphatase, only L-carnitine level in the cauda epididymis was significantly reduced in the tacrolimus 3 mg kg(-1)day(-1) group. However, no significant difference was seen in the plasma L-carnitine. It was suggested that lowering of L-carnitine in the cauda epididymis was attributable to the adverse effect on epididymal function to transport and/or concentrate L-carnitine. Since L-carnitine has been reported to have antioxidant potential, antioxidant defense enzymes in the cauda epididymis such as superoxide dismutase (SOD), catalase, glutathione peroxidase and glutathione reductase were evaluated. The results showed no significant differences in activities, confirming that the treatment with tacrolimus did not affect the activities of these antioxidant enzymes. In conclusion, this study indicates that tacrolimus induces a decrease in L-carnitine level in the cauda epididymis, which is probably caused by impairment of epididymal function to transport and/or concentrate L-carnitine from bloodstream, and a decrease in sperm count.

  8. Evaluation of erythrocyte antioxidant mechanisms: antioxidant enzymes, lipid peroxidation, and serum trace elements associated with progressive anemia in ovine malignant theileriosis.

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    Nazifi, S; Razavi, S M; Kianiamin, P; Rakhshandehroo, E

    2011-08-01

    Ovine malignant theileriosis is a fatal disease that is characterized by severe progressive anemia. In order to elucidate the underlying mechanisms involved in anemia, this study was designed to assess the antioxidant status and erythrocyte oxidative injuries in Iranian fat-tailed sheep that suffered from malignant theileriosis. The infected animals (infected group), composed of 50 Iranian sheep about 1-2 years old, naturally infected with Theileria sp., were divided into three subgroups according to parasitemia rates (<1%, 1-3%, 3-5%), and ten non-infected animals were also selected as the control group. Blood samples were taken and hematological parameters, the activities of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, erythrocyte osmotic fragility, and serum concentrations of some trace elements (copper, iron, zinc, manganese, and selenium), were measured. As an index of lipid peroxidation, the level of malondialdehyde (MDA) was also determined. According to the results, a significant decrease in red blood cell (RBC) count, packed cell volume, the activities of SOD, GPX, and catalase (P <0.001), and also serum concentrations of Cu, Zn, Mn, and Se (P < 0.05) were evident in the infected sheep. In contrast, significantly increased levels of MDA and erythrocyte osmotic fragility (P < 0.001) as well as serum concentration of iron (P < 0.05) were recorded in the infected animals. The significant decrease in antioxidant enzyme activities and substantial elevated levels of lipid peroxidation and erythrocyte osmotic fragility associated with the increase in parasitemia indicate increased exposure of RBCs to oxidative damage. Also, it appears that disturbed antioxidant defense mechanisms can promote the development of anemia in ovine theileriosis.

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

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    Aly, Hamdy A.A., E-mail: hamdyaali@yahoo.com [Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah (Saudi Arabia); Domènech, Òscar [Department of Physical Chemistry, Faculty of Pharmacy, Barcelona University (Spain); Banjar, Zainy M. [Department of Medical Biology, School of Medicine, King Abdulaziz University, Jeddah (Saudi Arabia)

    2012-06-01

    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 (H{sub 2}O{sub 2}) 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

  10. Defense mechanisms against radiation induced teratogenic damage in mice

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    Kato, F.; Ootsuyama, A.; Nomoto, S.; Norimura, T. [Univ. of Occupational and Environmental Health, Kitakyushu, (Japan)

    2002-07-01

    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.

  11. Tissue-specific defense and thermo-adaptive mechanisms of soybean seedlings under heat stress revealed by proteomic approach.

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    Ahsan, Nagib; Donnart, Tifenn; Nouri, Mohammad-Zaman; Komatsu, Setsuko

    2010-08-06

    A comparative proteomic approach was employed to explore tissue-specific protein expression patterns in soybean seedlings under heat stress. The changes in the protein expression profiles of soybean seedling leaves, stems, and roots were analyzed after exposure to high temperatures. A total of 54, 35, and 61 differentially expressed proteins were identified from heat-treated leaves, stems, and roots, respectively. Differentially expressed heat shock proteins (HSPs) and proteins involved in antioxidant defense were mostly up-regulated, whereas proteins associated with photosynthesis, secondary metabolism, and amino acid and protein biosynthesis were down-regulated in response to heat stress. A group of proteins, specifically low molecular weight HSPs and HSP70, were up-regulated and expressed in a similar manner in all tissues. Proteomic analysis indicated that the responses of HSP70, CPN-60 beta, and ChsHSP were tissue specific, and this observation was validated by immunoblot analysis. The heat-responsive sHSPs were not induced by other stresses such as cold and hydrogen peroxide. Taken together, these results suggest that to cope with heat stress soybean seedlings operate tissue-specific defenses and adaptive mechanisms, whereas a common defense mechanism associated with the induction of several HSPs was employed in all three tissues. In addition, tissue-specific proteins may play a crucial role in defending each type of tissues against thermal stress.

  12. Cannabidiol Post-Treatment Alleviates Rat Epileptic-Related Behaviors and Activates Hippocampal Cell Autophagy Pathway Along with Antioxidant Defense in Chronic Phase of Pilocarpine-Induced Seizure.

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    Hosseinzadeh, Mahshid; Nikseresht, Sara; Khodagholi, Fariba; Naderi, Nima; Maghsoudi, Nader

    2016-04-01

    Abnormal and sometimes severe behavioral and molecular symptoms are usually observed in epileptic humans and animals. To address this issue, we examined the behavioral and molecular aspects of seizure evoked by pilocarpine. Autophagy can promote both cell survival and death, but there are controversial reports about the neuroprotective or neurodegenerative effects of autophagy in seizure. Cannabidiol has anticonvulsant properties in some animal models when used as a pretreatment. In this study, we investigated alteration of seizure scores, autophagy pathway proteins, and antioxidant status in hippocampal cells during the chronic phase of pilocarpine-induced epilepsy after treatment with cannabidiol. Cannabidiol (100 ng, intracerebroventricular injection) delayed the chronic phase of epilepsy. Single administration of cannabidiol during the chronic phase of seizure significantly diminished seizure scores such as mouth clonus, head nodding, monolateral and bilateral forelimb clonus and increased the activity of catalase enzyme and reduced glutathione content. Such a protective effect in the behavioral scores of epileptic rats was also observed after repeated administrations of cannabidiol at the onset of the silent phase. Moreover, the amount of Atg7, conjugation of Atg5/12, Atg12, and LC3II/LC3I ratio increased significantly in epileptic rats treated with repeated injections of cannabidiol. In short, our results suggest that post-treatment of Cannabidiol could enhance the induction of autophagy pathway and antioxidant defense in the chronic phase of epilepsy, which could be considered as the protective mechanisms of cannabidiol in a temporal lobe epilepsy model.

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

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    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.

  14. Activation of antioxidant defenses in whole saliva by psychosocial stress is more manifested in young women than in young men.

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    Viktoriia Tsuber

    Full Text Available Psychosocial stress has been long known to have deleterious effects on health. Nevertheless, an exposure to moderate stressors enhances resilience and promotes health benefits. Male and female organisms differ in many aspects of health and disease. The aim of this study was to investigate antioxidant activity and oxidative damage in saliva in a psychosocial stress paradigm in men and women. Here, we show that an acute stressor of moderate strength augments antioxidant activity and decreases oxidative damage in whole saliva of young people. An examination stress caused a significant increase of catalase activity, accompanied by a decrease of levels of oxidized proteins. Levels of thiobarbituric acid-reacting substances did not increase at stress, indicating that lipid peroxidation was not activated. The stress-induced alterations were more manifested in young women compared to young men. Thus, antioxidant protective mechanisms are more activated by a moderate stressor in young women than in young men.

  15. Enhancement of antioxidant defense system by epigallocatechin-3-gallate during bleomycin induced experimental pulmonary fibrosis.

    Science.gov (United States)

    Sriram, Narayanan; Kalayarasan, Srinivasan; Sudhandiran, Ganapasam

    2008-07-01

    Oxidative stress resulting from an imbalance between radical-generating and radical scavenging systems plays an important role in the pathogenesis of pulmonary fibrosis. Epigallocatechin-3-gallate (EGCG), a polyphenol and a major component of green tea, possess a potent antioxidant property. This study was designed to evaluate the potential antioxidative activity of EGCG in the plasma and lungs during bleomycin induced experimental pulmonary fibrosis. Intratracheal administration of bleomycin (6.5 U/kg body weight) to rats resulted in significant reduction of body weight, enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase) and non-enzymic antioxidants (reduced glutathione, vitamin C, vitamin E and vitamin A). Elevations in lung W/D (wet weight/dry weight) ratio, hydroxyproline content was observed with a synchronized increase in lipid peroxidation markers (thiobarbituric acid reactive substances and hydroperoxides). Intraperitoneal administration of EGCG at a dose of 20 mg/kg body weight significantly improved the body weight, enzymic and non enzymic antioxidants and considerably decreased the W/D ratio, hydroxyproline and lipid peroxidation marker levels. Histological observations also correlated with the biochemical parameters. Thus, this study confirms the beneficial use of EGCG in alleviating the oxidative stress induced during pulmonary fibrosis.

  16. Influence of subacute treatment of some plant growth regulators on serum marker enzymes and erythrocyte and tissue antioxidant defense and lipid peroxidation in rats.

    Science.gov (United States)

    Celik, Ismail; Tuluce, Yasin; Isik, Ismail

    2006-01-01

    This study aims to investigate the effects of the plant growth regulators (PGRs) (2,3,5-triiodobenzoic acid (TIBA), Naphthaleneacetic acid (NAA), and 2,4-dichlorofenoxyacetic acid (2,4-D)) on serum marker enzymes (aspartate aminotransferase (AST), alanin aminotransferase (ALT), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH)), antioxidant defense systems (reduced glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), glutathione-S-transferase (GST), and catalase (CAT)), and lipid peroxidation content (malondialdehyde = MDA) in various tissues of rats. 50 and 100 ppm of PGRs as drinking water were administered orally to rats (Sprague-Dawley albino) ad libitum for 25 days continuously. The PGRs treatment caused different effects on the serum marker enzymes, antioxidant defense systems, and the MDA content in experimented rats compared to controls. Results showed that TIBA caused a significant decrease in serum AST activity with both the dosage whereas serum CPK was significantly increased with 100 ppm dosage of TIBA. Meanwhile, serum AST, CPK, and LDH activities were significantly increased with both dosage of NAA and 2,4-D. The lipid peroxidation end-product MDA significantly increased in the all tissues treated with both dosages of PGRs without any change in the brain and erythrocyte of rats treated with both the dosages of 2,4-D. The GSH depletion in the kidney and brain tissues of rats treated with both dosages of PGRs was found to be significant. Furthermore, the GSH depletion in the erythrocyte of rats treated with both dosages of PGRs except 50 ppm dosage of 2,4-D was significant too. Also, the GSH level in the liver was significantly depleted with 50 ppm of 2,4-D and NAA, whereas the GSH depletion in the same tissue did not significantly change with the treatment. The activity of antioxidant enzymes was also seriously affected by PGRs; SOD significantly decreased in the liver, heart, kidney, and brain of rats treated with

  17. Antioxidant defenses in human blood plasma and extra-cellular fluids.

    Science.gov (United States)

    Stocker, Roland

    2016-04-01

    I had the fortune to be introduced to Helmut Sies during the mid 1980s, while working as a post-doctoral scientist at the University of California, Berkeley. At that time, Helmut was a frequent visitor of the Bruce Ames' laboratory and a leading authority in antioxidants and oxidative stress. His concepts, ideas and willingness to listen and make constructive suggestions have been far-reaching and visionary. Moreover, they have also been highly infectious, so much so that much of my research to this day has been on the same topic. The following is a personal recount on how the field of antioxidants has evolved since those exciting days in Berkeley.

  18. Experimental evidence for protein oxidative damage and altered antioxidant defense in patients with medium-chain acyl-CoA dehydrogenase deficiency

    NARCIS (Netherlands)

    Derks, Terry G J; Touw, Catharina M L; Ribas, Graziela S; Biancini, Giovana B; Vanzin, Camila S; Negretto, Giovanna; Mescka, Caroline P; Reijngoud, Dirk Jan; Smit, G Peter A; Wajner, Moacir; Vargas, Carmen R

    2014-01-01

    The objective of this study was to test whether macromolecule oxidative damage and altered enzymatic antioxidative defenses occur in patients with medium-chain acyl coenzyme A dehydrogenase (MCAD) deficiency. We performed a cross-sectional observational study of in vivo parameters of lipid and prote

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

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    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.

  20. 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

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

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    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.

  2. 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.

  3. 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.

  4. 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.

  5. Endomorphins, endogenous opioid peptides, provide antioxidant defense in the brain against free radical-induced damage.

    Science.gov (United States)

    Lin, Xin; Yang, Ding-Jian; Cai, Wen-Qing; Zhao, Qian-Yu; Gao, Yan-Feng; Chen, Qiang; Wang, Rui

    2003-11-20

    Oxidative stress has been considered to be a major cause of cellular injuries in a variety of chronic health problems, such as carcinogenesis and neurodegenerative disorders. The brain appears to be more susceptible to oxidative damage than other organs. Therefore, the existence of antioxidants may be essential in brain protective systems. The antioxidative and free radical scavenging effects of endomorphin 1 (EM1) and endomorphin 2 (EM2), endogenous opioid peptides in the brain, have been investigated in vitro. The oxidative damage was initiated by a water-soluble initiator 2,2'-azobis(2-amidinopropane hydrocholoride) (AAPH) and hydrogen peroxide (H2O2). The linoleic acid peroxidation, DNA and protein damage were monitored by formation of hydroperoxides, by plasmid pBR 322 DNA nicking assay and single-cell alkaline electrophoresis, and by SDS-polyacrylamide gel electrophoresis. Endomorphins can inhibit lipid peroxidation, DNA strand breakage, and protein fragmentation induced by free radical. Endomorphins also reacted with galvinoxyl radicals in homogeneous solution, and the pseudo-first-order rate constants were determined spectrophotometrically by following the disappearance of galvinoxyl radicals. In all assay systems, EM1 was more potent than EM2 and GSH, a major intracellular water-soluble antioxidant. We propose that endomorphins are one of the protective systems against free radical-induced damage in the brain.

  6. 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.

  7. Hydrogen Peroxide Pretreatment Mitigates Cadmium-Induced Oxidative Stress in Brassica napus L.: An Intrinsic Study on Antioxidant Defense and Glyoxalase Systems

    Science.gov (United States)

    Hasanuzzaman, Mirza; Nahar, Kamrun; Gill, Sarvajeet S.; Alharby, Hesham F.; Razafindrabe, Bam H. N.; Fujita, Masayuki

    2017-01-01

    detoxification. So, the major roles of H2O2 were improvement of antioxidant defense system and glyoxalase system which protected plants from the damage effects of ROS and MG. The mechanism of H2O2 to induce antioxidant defense and glyoxalase system and improving physiology under stress condition is not known clearly which should be elucidated. The signaling roles of H2O2 and its interaction with other signaling molecules, phytohormones or other biomolecules and their roles in stress protection should be explored. PMID:28239385

  8. Baicalein, a Bioflavonoid, Prevents Cisplatin-Induced Acute Kidney Injury by Up-Regulating Antioxidant Defenses and Down-Regulating the MAPKs and NF-κB Pathways.

    Directory of Open Access Journals (Sweden)

    Bidya Dhar Sahu

    Full Text Available Acute renal failure is a serious complication of the anticancer drug cisplatin. The potential role of baicalein, a naturally occurring bioflavonoid on cisplatin-induced renal injury is unknown. Here, we assessed the effect of baicalein against a murine model of cisplatin-induced acute renal failure and investigated the underlying possible mechanisms. Renal function, kidney histology, inflammation, oxidative stress, renal mitochondrial function, proteins involved in apoptosis, nuclear translocation of Nrf2 and effects on intracellular signaling pathways such as MAPKs, and NF-κB were assessed. Pretreatment with baicalein ameliorated the cisplatin-induced renal oxidative stress, apoptosis and inflammation and improved kidney injury and function. Baicalein inhibited the cisplatin-induced expression of iNOS, TNF-α, IL-6 and mononuclear cell infiltration and concealed redox-sensitive transcription factor NF-κB activation via reduced DNA-binding activity, IκBα phosphorylation and p65 nuclear translocation in kidneys. Further studies demonstrated baicalein markedly attenuated cisplatin-induced p38 MAPK, ERK1/2 and JNK phosphorylation in kidneys. Baicalein also restored the renal antioxidants and increased the amount of total and nuclear accumulation of Nrf2 and downstream target protein, HO-1 in kidneys. Moreover, baicalein preserved mitochondrial respiratory enzyme activities and inhibited cisplatin-induced apoptosis by suppressing p53 expression, Bax/Bcl-2 imbalance, cytochrome c release and activation of caspase-9, caspase-3 and PARP. Our findings suggest that baicalein ameliorates cisplatin-induced renal damage through up-regulation of antioxidant defense mechanisms and down regulation of the MAPKs and NF-κB signaling pathways.

  9. Baicalein, a Bioflavonoid, Prevents Cisplatin-Induced Acute Kidney Injury by Up-Regulating Antioxidant Defenses and Down-Regulating the MAPKs and NF-κB Pathways.

    Science.gov (United States)

    Sahu, Bidya Dhar; Mahesh Kumar, Jerald; Sistla, Ramakrishna

    2015-01-01

    Acute renal failure is a serious complication of the anticancer drug cisplatin. The potential role of baicalein, a naturally occurring bioflavonoid on cisplatin-induced renal injury is unknown. Here, we assessed the effect of baicalein against a murine model of cisplatin-induced acute renal failure and investigated the underlying possible mechanisms. Renal function, kidney histology, inflammation, oxidative stress, renal mitochondrial function, proteins involved in apoptosis, nuclear translocation of Nrf2 and effects on intracellular signaling pathways such as MAPKs, and NF-κB were assessed. Pretreatment with baicalein ameliorated the cisplatin-induced renal oxidative stress, apoptosis and inflammation and improved kidney injury and function. Baicalein inhibited the cisplatin-induced expression of iNOS, TNF-α, IL-6 and mononuclear cell infiltration and concealed redox-sensitive transcription factor NF-κB activation via reduced DNA-binding activity, IκBα phosphorylation and p65 nuclear translocation in kidneys. Further studies demonstrated baicalein markedly attenuated cisplatin-induced p38 MAPK, ERK1/2 and JNK phosphorylation in kidneys. Baicalein also restored the renal antioxidants and increased the amount of total and nuclear accumulation of Nrf2 and downstream target protein, HO-1 in kidneys. Moreover, baicalein preserved mitochondrial respiratory enzyme activities and inhibited cisplatin-induced apoptosis by suppressing p53 expression, Bax/Bcl-2 imbalance, cytochrome c release and activation of caspase-9, caspase-3 and PARP. Our findings suggest that baicalein ameliorates cisplatin-induced renal damage through up-regulation of antioxidant defense mechanisms and down regulation of the MAPKs and NF-κB signaling pathways.

  10. Immature psychological defense mechanisms are associated with greater personal importance of junk food, alcohol, and television.

    Science.gov (United States)

    Costa, Rui Miguel; Brody, Stuart

    2013-10-30

    Immature psychological defense mechanisms are psychological processes that play an important role in suppressing emotional awareness and contribute to psychopathology. In addition, unhealthy food, television viewing, and alcohol consumption can be among the means to escape self-awareness. In contrast, engaging in, and responding fully to specifically penile-vaginal intercourse (PVI) is associated with indices of better emotional regulation, including less use of immature defense mechanisms. There was a lack of research on the association of immature defense mechanisms with personal importance of junk food, alcohol, television, PVI, and noncoital sex. In an online survey, 334 primarily Scottish women completed the Defense Style Questionnaire (DSQ-40), and rated the personal importance of junk food, alcohol, television, PVI, and noncoital sex. Immature defense mechanisms correlated with importance of junk food, alcohol, and television. Importance of PVI correlated with mature defenses, and less use of some component immature defenses. Importance of alcohol correlated with importance of junk food, television, and noncoital sex. Importance of junk food was correlated with importance of television and noncoital sex. The findings are discussed in terms of persons with poorer self-regulatory abilities having more interest in junk food, television, and alcohol, and less interest in PVI.

  11. 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

  12. Study of defensive methods and mechanisms in developmental, emotional (internalization), and disruptive behavior (externalization) disorders.

    Science.gov (United States)

    Jamilian, H R; Zamani, N; Darvishi, M; Khansari, M R

    2014-09-18

    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. Tools of research were structured clinical interview of forth cognitive and statistical guide of psychopathic disorders for axis I and the way used for assess defensive mechanisms is defensive method 40 question's questionnaires of Andrews (1993). The data are compared by statistical methods comparison of averages and one way variance analysis and HSD tests and results show that undeveloped defensive mechanisms in by developmental disorder family (25.2 ± 3.7) mean and standard deviation, it is most used mechanism and in disruptive behavior disorder family by (11.2 ± 1.9) mean and standard deviation is used least mechanism and in developed mechanism of emotional disorder family by (7.8 ± 3.1) mean and standard deviation is most used mechanism and in developmental disorder family by (4.3 ± 1.5) mean and standard deviation is least mechanism in neuroticism patient, social phobia affected emotional disorder family (15.6 ± 2.6) and disruptive behavior disorder family have least mean and standard deviation (9.2 ± 1.7) (p< 0.005). Recent research shows significant of study defensive mechanism in psychopathic family of disorder children that affecting on the way of life of persons and interpersonal and intrapersonal relations and method of solving problem in family of them in life, so defensive mechanisms require more attention.

  13. Antioxidant defenses of mycorrhizal fungus infection against SO(2)-induced oxidative stress in Avena nuda seedlings.

    Science.gov (United States)

    Huang, L L; Yang, C; Zhao, Y; Xu, X; Xu, Q; Li, G Z; Cao, J; Herbert, S J; Hao, L

    2008-11-01

    Colonization of arbuscular mycorrhizal fungi Glomus mosseae increased Avena nuda seedling tolerance to SO(2) exposure, as indicated by elevated total plant biomass and ameliorative photosynthetic rate, when compared to the non-mycorrhizal plants. This is associated with an improved antioxidant capacity as shown by enhanced superoxide dismutase and catalase activity, increased ascorbic acid and glutathione content, and reduced malondialdehyde and hydrogen peroxide level in the mycorrhizal plants relative to the non-mycorrhizal plants under SO(2) exposure. The mycorrhizal fungi colonization had no effect on the stomatal conductance. To our knowledge, this is the first finding of this sort.

  14. 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 (p0.05), 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.

  15. Effect of long term intake of aspartame on antioxidant defense status in liver.

    Science.gov (United States)

    Abhilash, M; Paul, M V Sauganth; Varghese, Mathews V; Nair, R Harikumaran

    2011-06-01

    The present study evaluates the effect of long term intake of aspartame, the artificial sweetener, on liver antioxidant system and hepatocellular injury in animal model. Eighteen adult male Wistar rats, weighing 150-175 g, were randomly divided into three groups as follows: first group was given aspartame dissolved in water in a dose of 500 mg/kg b.wt.; the second group was given a dose of 1000 mg/kg b.wt.; and controls were given water freely. Rats that had received aspartame (1000 mg/kg b.wt.) in the drinking water for 180 days showed a significant increase in activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyl transferase (GGT). The concentration of reduced glutathione (GSH) and the activity of glutathione peroxidase (GPx), and glutathione reductase (GR) were significantly reduced in the liver of rats that had received aspartame (1000 mg/kg b.wt.). Glutathione was significantly decreased in both the experimental groups. Histopathological examination revealed leukocyte infiltration in aspartame-treated rats (1000 mg/kg b.wt.). It can be concluded from these observations that long term consumption of aspartame leads to hepatocellular injury and alterations in liver antioxidant status mainly through glutathione dependent system.

  16. Effect of heavy metals on growth response and antioxidant defense protection in Bacillus cereus.

    Science.gov (United States)

    Behera, Madhumita; Dandapat, Jagneshwar; Rath, Chandi Charan

    2014-11-01

    Bacterial cells in aerobic environment generate reactive oxygen species which may lead to oxidative stress, induced by a wide range of environmental factors including heavy metals. In the present context an attempt has been made to determine the toxic impact of cadmium and copper on growth performance, oxidative stress, and relative level of antioxidant protection in Bacillus cereus. Outcome of this study suggests that both the metal ions depleted the growth rate in this organism with respect to time and concentration of the metal ions. CdCl2 exposure induced extracellular glutathione (GSH) production, whereas, its level was declined in response to CuSO4. Superoxide dismutase (SOD) activity and hydrogen peroxide (H2 O2 ) content was elevated under CdCl2 stress but the activity of catalase (CAT) was inhibited. In contrast, incubation of bacteria with CuSO4 exhibited decreased SOD activity with concomitant rise in CAT activity and H2 O2 content. We also observed elevation of intracellular GSH level in this bacteria following supplementation of N-acetyl cysteine (NAC) in the medium. Overall findings of this study indicated differential toxicity of CdCl2 and CuSO4 in inducing oxidative stress, depleting growth rate and the possible involvement of GSH and CAT in adaptive antioxidant response.

  17. Changes in antioxidant defense status in hypercholesterolemic rats treated with Ajuga iva.

    Science.gov (United States)

    Bouderbala, S; Lamri-Senhadji, M; Prost, J; Lacaille-Dubois, M A; Bouchenak, M

    2008-06-01

    The aim of the study was to investigate the effect of aqueous extract of Ajuga iva (Ai) on serum and tissues lipid peroxidation as well as antioxidant enzymes activities in red blood cells (RBC) and tissues, in high hypercholesterolemic rats (HC). Male Wistar rats (n=12) were fed on 1% cholesterol-enriched diet for 15d. After this adaptation phase, hypercholesterolemic rats (total cholesterol=6.5+/-0.6mol/l) were divided into two groups fed the same diet and treated or not with Ai for 15d. Thiobarbituric acid reactive substances (TBARS) concentrations in serum, LDL-HDL(1), HDL(2) and HDL(3) were respectively, 5-, 7.8-, 2.3- and 5-fold lower in Ai treated than untreated hypercholesterolemic groups. TBARS concentrations were 1.4-fold lower in heart and 2.8-fold higher in kidney in Ai-HC treated than untreated HC group. Superoxide dismutase activity was respectively, 1.2- and 1.4-fold higher in RBC and muscle in Ai treated than untreated group. In RBC, Ajuga iva treatment enhanced glutathione peroxidase (GSH-Px) (+9%) and glutathione reductase (GSSH-Red) (+12%) in Ai-HC treated than untreated HC group. GSSH-Red activity was 1.4- and 1.5-fold higher in adipose tissue and heart, respectively and 3.7-fold lower in kidney in Ai treated than untreated group. Liver catalase activity was 1.6-fold higher in Ai treated than untreated group. Adipose tissue and muscle total glutathione content represented in Ai treated group 35% and 36% of the value noted in untreated group. Nitric oxide values of liver, adipose tissue and heart were 3.3-, 2.5- and 3.4-fold higher in Ai-HC than HC group. Ajuga iva treatment enhanced alpha-tocopherol contents (+25%) in Ai treated than untreated group. In conclusion, Ajuga iva treatment is more effective to improve the antioxidant capacity of RBC than that of tissues. Indeed, Ai is able to reduce the oxidative stress in hypercholesterolemic rats by increasing the antioxidant enzymes activity.

  18. Application of Plant-Growth-Promoting Fungi Trichoderma longibrachiatum T6 Enhances Tolerance of Wheat to Salt Stress through Improvement of Antioxidative Defense System and Gene Expression

    Science.gov (United States)

    Zhang, Shuwu; Gan, Yantai; Xu, Bingliang

    2016-01-01

    Soil salinity is a serious problem worldwide that reduces agricultural productivity. Trichoderma longibrachiatum T6 (T6) has been shown to promote wheat growth and induce plant resistance to parasitic nematodes, but whether the plant-growth-promoting fungi T6 can enhance plant tolerance to salt stress is unknown. Here, we determined the effect of plant-growth-promoting fungi T6 on wheat seedlings’ growth and development under salt stress, and investigated the role of T6 in inducing the resistance to NaCl stress at physiological, biochemical, and molecular levels. Wheat seedlings were inoculated with the strain of T6 and then compared with non-inoculated controls. Shoot height, root length, and shoot and root weights were measured on 15 days old wheat seedlings grown either under 150 mM NaCl or in a controlled setting without any NaCl. A number of colonies were re-isolated from the roots of wheat seedlings under salt stress. The relative water content in the leaves and roots, chlorophyll content, and root activity were significantly increased, and the accumulation of proline content in leaves was markedly accelerated with the plant growth parameters, but the content of leaf malondialdehyde under saline condition was significantly decreased. The antioxidant enzymes-superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in wheat seedlings were increased by 29, 39, and 19%, respectively, with the application of the strain of T6 under salt stress; the relative expression of SOD, POD, and CAT genes in these wheat seedlings were significantly up-regulated. Our results indicated that the strain of T6 ameliorated the adverse effects significantly, protecting the seedlings from salt stress during their growth period. The possible mechanisms by which T6 suppresses the negative effect of NaCl stress on wheat seedling growth may be due to the improvement of the antioxidative defense system and gene expression in the stressed wheat plants. PMID:27695475

  19. 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 (pglutathione peroxidase, glutathione S-transferase, glutathione reductase and catalase) and non-enzymatic (reduced glutathione, ascorbic acid and α-tocopherol) antioxidants (ptesticular ineffectiveness in rats by modulating redox proteins and oxidative defense mechanisms.

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

    Science.gov (United States)

    Ponce de León, Inés; Montesano, Marcos

    2013-02-04

    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 microbial infection. The ancestral position among land plants, the sequenced genome and the feasibility of generating targeted knock-out mutants by homologous recombination has made the moss Physcomitrella patens an attractive model to perform functional studies of plant genes involved in stress responses. This paper reviews the current knowledge of inducible defense mechanisms in P. patens and compares them to those activated in flowering plants after pathogen assault, including the reinforcement of the cell wall, ROS production, programmed cell death, activation of defense genes and synthesis of secondary metabolites and defense hormones. The knowledge generated in P. patens together with comparative studies in flowering plants will help to identify key components in plant defense responses and to design novel strategies to enhance resistance to biotic stress.

  1. Dietary Curcumin Increases Antioxidant Defenses in Lung, Ameliorates Radiation-Induced Pulmonary Fibrosis, and Improves Survival in Mice

    Science.gov (United States)

    Lee, James C.; Kinniry, Paul A.; Arguiri, Evguenia; Serota, Matthew; Kanterakis, Stathis; Chatterjee, Shampa; Solomides, Charalambos C.; Javvadi, Prashanthi; Koumenis, Constantinos; Cengel, Keith A.; Christofidou-Solomidou, Melpo

    2010-01-01

    The effectiveness of lung radiotherapy is limited by radiation tolerance of normal tissues and by the intrinsic radiosensitivity of lung cancer cells. The chemopreventive agent curcumin has known antioxidant and tumor cell radiosensitizing properties. Its usefulness in preventing radiation-induced pneumonopathy has not been tested previously. We evaluated dietary curcumin in radiation-induced pneumonopathy and lung tumor regression in a murine model. Mice were given 1%or 5%(w/w) dietary curcumin or control diet prior to irradiation and for the duration of the experiment. Lungs were evaluated at 3 weeks after irradiation for acute lung injury and inflammation by evaluating bronchoalveolar lavage (BAL) fluid content for proteins, neutrophils and at 4 months for pulmonary fibrosis. In a separate series of experiments, an orthotopic model of lung cancer using intravenously injected Lewis lung carcinoma (LLC) cells was used to exclude possible tumor radioprotection by dietary curcumin. In vitro, curcumin boosted antioxidant defenses by increasing heme oxygenase 1 (HO-1) levels in primary lung endothelial and fibroblast cells and blocked radiation-induced generation of reactive oxygen species (ROS). Dietary curcumin significantly increased HO-1 in lungs as early as after 1 week of feeding, coinciding with a steady-state level of curcumin in plasma. Although both 1% and 5% w/w dietary curcumin exerted physiological changes in lung tissues by significantly decreasing LPS-induced TNF-α production in lungs, only 5%dietary curcumin significantly improved survival of mice after irradiation and decreased radiation-induced lung fibrosis. Importantly, dietary curcumin did not protect LLC pulmonary metastases from radiation killing. Thus dietary curcumin ameliorates radiation-induced pulmonary fibrosis and increases mouse survival while not impairing tumor cell killing by radiation. PMID:20426658

  2. Salicylic acid mediates antioxidant defense system and ABA pathway related gene expression in Oryza sativa against quinclorac toxicity.

    Science.gov (United States)

    Wang, Jian; Lv, Mengting; Islam, Faisal; Gill, Rafaqat A; Yang, Chong; Ali, Basharat; Yan, Guijun; Zhou, Weijun

    2016-11-01

    The auxin herbicide quinclorac is widely used for controlling weeds in transplanted and direct-seeded rice fields. However, its phytotoxic responses on rice are still unknown. Therefore, in the present investigation we studied the effects of different concentrations (0, 0.1 and 0.5g/L) of quinclorac herbicide on the physiological and biochemical changes of two rice cultivars (XS 134 and ZJ 88) and further analyzed the ameliorating role of salicylic acid (SA) on quinclorac toxicity in rice plants. The results revealed that exogenous application of SA significantly increased plant biomass and total chlorophyll contents in herbicide stressed plants. The lipid peroxidation and ROS (H2O2, O2(-.), (-)OH) production were significantly increased in roots and leaves of both rice cultivars under quinclorac stress, demonstrating an oxidative burst in rice plants. Whereas, application of SA significantly lowered ROS contents under quinclorac stress. Further, exogenous SA treatment significantly modulated antioxidant enzymes and enhanced GSH concentration in stress plants. Anatomical observations of leaf and root revealed that herbicide affected internal structures, while SA played a vital role in protection from toxic effects. Expression analysis of stress hormone ABA genes (OsABA8oxs, OsNCEDs) revealed that quinclorac application enhanced stress condition in cultivar ZJ 88, while SA treatment downregulated ABA genes more in cultivar XS 134, which correlated with the enhanced tolerance to quinclorac induced oxidative stress in this cultivar. The present study delineated that SA played a critical role under quinclorac stress in both rice cultivars by regulating antioxidant defense system, reducing ROS formation and preventing the degradation of internal cell organelles.

  3. Involvement of Antioxidative Defense System in Rice Seedlings Exposed to Aluminum Toxicity and Phosphorus Deficiency

    Institute of Scientific and Technical Information of China (English)

    GUO Tian-rong; YAO Peng-cheng; ZHANG Zi-dong; WANG Jiang-jia; WANG Mei

    2012-01-01

    Plants growing in acid soils may suffer both phosphorus (P) deficiency and aluminum (AI) toxicity.Hydroponic experiments were undertaken to assess the single and combination effects of AI toxicity and low P stress on seedling growth,chlorophyll and proline contents,antioxidative response and lipid peroxidation of two rice genotypes (Yongyou 8 and Xiushui 132) differing in AI tolerance.AI toxicity and P deficiency both inhibited rice seedling growth.The development of toxic symptoms was characterized by reduced chlorophyll content,increased proline and malondialdehyde contents in both roots and leaves,and increased peroxidase and superoxide dismutase activities in roots,but decreased in leaves.The stress condition induced more severe growth inhibition and oxidative stress in Yongyou 8,and Xiushui 132 showed higher tolerance to both AI toxicity and P deficiency.P deficiency aggravated A(I) toxicity to plant growth and induced more severe lipid peroxidation.

  4. 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.

  5. 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.

  6. 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

    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...... defense. Design: A 25-d intervention study with complete control of dietary intake was performed in 43 healthy male and female nonsmokers who were randomly assigned to 1 of 3 groups. In addition to a basic diet devoid of fruit and vegetables, the fruit and vegetables (Fruveg) group received 600 g fruit...... 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...

  7. [The condition of the system "peroxide oxidation of lipids-antioxidant defense" in mixed saliva of patients with chronic generalized periodontitis].

    Science.gov (United States)

    Butiyugin, I A; Volchegorskiy, I A

    2014-02-01

    The comparative analysis was made concerning conditions of the system "Peroxide oxidation of lipids-antioxidant defenses in mixed saliva of patients with chronic disseminated periodontitis of light (n = 45), mean (n = 36) and severe (n = 18) degrees. The control group consisted of 25 clinically healthy persons with intact periodontium. The study revealed that in comparison with control group, in patients with chronic disseminated periodontitis occurred an increasing of content of heptane-soluble diene conjugates, isopropanol-soluble ketodienes and conjugated trienes, ceruloplasmin and a decreasing of level of alpha-tocopherol, especially under severe degree of disease. The study also established a non-linear U-dependence between indicators of the system "Peroxide oxidation of lipids-antioxidant defenses" in mixed saliva and severity of affection of tissues of periodontium in patients with chronic disseminated dermatosis.

  8. An empirical look at the Defense Mechanism Test (DMT): reliability and construct validity.

    Science.gov (United States)

    Ekehammar, Bo; Zuber, Irena; Konstenius, Marja-Liisa

    2005-07-01

    Although the Defense Mechanism Test (DMT) has been in use for almost half a century, there are still quite contradictory views about whether it is a reliable instrument, and if so, what it really measures. Thus, based on data from 39 female students, we first examined DMT inter-coder reliability by analyzing the agreement among trained judges in their coding of the same DMT protocols. Second, we constructed a "parallel" photographic picture that retained all structural characteristic of the original and analyzed DMT parallel-test reliability. Third, we examined the construct validity of the DMT by (a) employing three self-report defense-mechanism inventories and analyzing the intercorrelations between DMT defense scores and corresponding defenses in these instruments, (b) studying the relationships between DMT responses and scores on trait and state anxiety, and (c) relating DMT-defense scores to measures of self-esteem. The main results showed that the DMT can be coded with high reliability by trained coders, that the parallel-test reliability is unsatisfactory compared to traditional psychometric standards, that there is a certain generalizability in the number of perceptual distortions that people display from one picture to another, and that the construct validation provided meager empirical evidence for the conclusion that the DMT measures what it purports to measure, that is, psychological defense mechanisms.

  9. Alterations of erythrocyte antioxidant mechanisms: antioxidant enzymes, lipid peroxidation and serum trace elements associated with anemia in bovine tropical theileriosis.

    Science.gov (United States)

    Razavi, S M; Nazifi, S; Bateni, M; Rakhshandehroo, E

    2011-08-25

    In order to investigate the alterations of erythrocyte protective antioxidant mechanisms, lipid peroxidation and trace elements associated with anemia in bovine tropical theileriosis, an infected group comprised of 50 crossbred Holstein cattle, about 1-2 years old, naturally infected with Theileria annulata, were divided into 4 subgroups according to their parasitemia rates (5%) and also 10 healthy cattle as control were selected. Blood samples were taken and hematological parameters, the activities of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase and serum concentrations of some antioxidant trace elements (copper, iron, zinc, manganese and selenium) were measured. As an index of lipid peroxidation, the level of Malondialdehyde (MDA) was also determined. The results showed a conspicuous decrease in the activities of SOD, GPX and catalase (P<0.01), and a significant decrease in the serum concentrations of Cu, Zn, Mn and Se in cattle with higher than 1% parasitemia (P<0.05) compared to the control. In addition, remarkable elevations in the MDA level (P<0.01) and serum concentration of iron (P<0.05) were observed in the infected animals. These findings pointed to the occurrence of exacerbating oxidative injuries to erythrocytes during parasitemia. Furthermore, it can be concluded that infection with T. annulata can interfere with protective antioxidant mechanisms of RBCs against oxidative damages, which promote the development of anemia.

  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. Testosterone enhances functional recovery after stroke through promotion of antioxidant defenses, BDNF levels and neurogenesis in male rats.

    Science.gov (United States)

    Fanaei, Hamed; Karimian, Seyed Morteza; Sadeghipour, Hamid Reza; Hassanzade, Gholamreza; Kasaeian, Amir; Attari, Fatemeh; Khayat, Samira; Ramezani, Vahid; Javadimehr, Mani

    2014-04-16

    It is reported that circulating testosterone levels decrease after cerebral ischemia. The aim of this study was to evaluate the effects of testosterone on oxidative stress, brain-derived neurotrophic factor (BDNF) levels, neurogenesis, histological damage and sensorimotor recovery in a castrated male rat model of focal cerebral ischemia. Animals were divided into four groups. For all animals, castrations were conducted 7 days before transient middle cerebral artery occlusion (MCAO) was done and cerebral ischemia was induced. The first group served as sham. Second was MCAO group and received vehicle only, third was MCAO group that was post-treated with testosterone and the fourth was MCAO group post-treated with testosterone and flutamide. Treatment only with testosterone significantly weakened oxidative stress and increased BDNF levels and sensorimotor recovery during a 10 days period. Rats receiving testosterone demonstrated a significant reduction in infarct volume and a significant increase in neurogenesis on 10th day after focal cerebral ischemia. Our results for the first time showed a potential advantageous effect of testosterone after cerebral ischemia in male rats, which was probably mediated by promoting antioxidant defenses, BDNF levels and neurogenesis.

  12. 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.

  13. 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.

  14. Effect of low doses of herbicide paraquat on antioxidant defense in Drosophila.

    Science.gov (United States)

    Krůček, Tomáš; Korandová, Michala; Šerý, Michal; Frydrychová, Radmila Čapková; Krůček, Tomáš; Korandová, Michala; Szakosová, Klára

    2015-04-01

    Despite a high toxicity, paraquat is one of the most widely used herbicides in the world. Our study evaluated the effect of paraquat exposure on antioxidant response and locomotion activity in Drosophila melanogaster. We examined the enzymatic activity of superoxide dismutase (SOD) and catalase, and the transcript levels of both enzymes. Flies were exposed to a wide range of paraquat concentrations (0.25 μM to 25 mM) for 12 h. SOD, at both transcript and enzymatic levels, revealed a biphasic dose-response curve with the peak at 2.5 μM paraquat. A similar dose-response curve was observed at transcript levels of catalase. Males revealed higher susceptibility to paraquat exposure, displaying higher lethality, increased levels of SOD activity, and increased peroxide levels than in females. We found that the exposure of females to 2.5 μM paraquat leads to an increase in locomotion activity. Because susceptibility to paraquat was enhanced by mating, the study supports the hypothesis of elevation of stress sensitivity as a physiological cost of reproduction.

  15. 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.

  16. EROD activity and antioxidant defenses of sea bass (Dicentrarchus labrax) after an in vivo chronic hydrocarbon pollution followed by a post-exposure period.

    Science.gov (United States)

    Danion, Morgane; Le Floch, Stéphane; Lamour, François; Quentel, Claire

    2014-12-01

    Chronic concentrations of polycyclic aromatic hydrocarbons (PAHs) have been commonly detected in international estuaries ecosystems. Reliable indicators still need to be found in order to properly assess the impact of PAHs in fish. After an in vivo chronic exposure to hydrocarbons, the enzymatic activity of 7-ethoxyresorufin O-deethylase (EROD) and the antioxidant defense system were assessed in sea bass, Dicentrarchus labrax. A total of 45 fish were exposed to the water-soluble fraction of Arabian crude oil, similar to a complex pollution by hydrocarbons chronically observed in situ, while 45 other control fish sustained the same experimental conditions in clean seawater. Fish samples were made after a 21-day exposure period and after a 15-day recovery period in clean fresh water. Throughout the experiment, liver EROD activity was significantly higher in contaminated fish than in control fish. In addition, nonenzymatic (total glutathione) and enzymatic (GPx, SOD, and CAT) antioxidant defense parameters measured in liver were not significantly different in fish. Furthermore, in gills, glutathione content had significantly increased while SOD activity had significantly decreased in contaminated fish compared to controls. On the other hand, CAT and GPx activities were not affected. Chronic exposure to PAHs disturbing the first step (SOD) and inhibiting the second step (GPx and CAT) could induce oxidative stress in tissues by the formation of oxygen radicals. After the postexposure period, there was no significant difference between control and contaminated fish in any of the antioxidant defense parameters measured in gills, attesting to the reversibility of the effects.

  17. Redox-dependent induction of antioxidant defenses by phenolic diterpenes confers stress tolerance in normal human skin fibroblasts: Insights on replicative senescence.

    Science.gov (United States)

    Carvalho, Ana C; Gomes, Andreia C; Pereira-Wilson, Cristina; Lima, Cristovao F

    2015-06-01

    Mild stress-induced hormesis represents a promising strategy for targeting the age-related accumulation of molecular damage and, therefore, for preventing diseases and achieving healthy aging. Fruits, vegetables, and spices contain a wide variety of hormetic phytochemicals, which may explain the beneficial health effects associated with the consumption of these dietary components. In the present study, the induction of cellular antioxidant defenses by the phenolic diterpenes carnosic acid (CA) and carnosol (CS) were studied in normal human skin fibroblasts, and insights into the aging process at the cellular level investigated. We observed that CA and CS induced several cytoprotective enzymes and antioxidant defenses in human fibroblasts, whose induction was dependent on the cellular redox state for CS and associated with Nrf2 signaling for both compounds. The stress response elicited by preincubation with CS conferred a cytoprotective action against a following oxidant challenge with tert-butyl hydroperoxide, confirming its hormetic effect. Preincubation of normal fibroblasts with CS also protected against hydrogen peroxide-induced premature senescence. Furthermore, cultivation of middle passage normal human skin fibroblasts in the presence of CS ameliorated the physiological state of cells during replicative senescence. Our results support the view that mild stress-induced antioxidant defenses by CS can confer stress tolerance in normal cells and may have important implications in the promotion of healthy aging.

  18. Brachycorynella asparagi (Mordv.) Induced—Oxidative Stress and Antioxidative Defenses of Asparagus officinalis L.

    Science.gov (United States)

    Borowiak-Sobkowiak, Beata; Woźniak, Agnieszka; Bednarski, Waldemar; Formela, Magda; Samardakiewicz, Sławomir; Morkunas, Iwona

    2016-01-01

    The aim of this study was to investigate whether and to what extent oxidative stress is induced in leaves of one- and two-month-old plants of Asparagus officinalis L. cv. Argenteuil infested by Brachycorynella asparagi (Mordvilko) at a varied population size. The pest B. asparagi has been described as the most damaging species feeding on asparagus. Analyses using electron paramagnetic resonance (EPR) demonstrated generally higher concentrations of semiquinone radicals with g-values of 2.0045 ± 0.0005 and 2.0026 ± 0.0005 in Asparagus officinalis (A. officinalis) leaves after Brachycorynella asparagi (B. asparagi) infestation than in the control. Observations of leaves under a confocal microscope showed a post-infestation enhanced generation of the superoxide anion radical (O2•−) and hydrogen peroxide (H2O2) in comparison to the control. Strong fluctuations in Mn2+ ion levels detected by EPR spectroscopy versus time were detected in leaves infested by aphids, which may indicate the involvement of these ions in the control of O2•− production. An enhanced superoxide dismutase activity is an important element in leaf defense against oxidative stress. Visible symptoms were found in aphid-infested A. officinalis. Damage to leaves of one- and two-month-old A. officinalis plants by the aphid B. asparagi was dependent on the intensity, duration of infestation and plant age. PMID:27775613

  19. Brachycorynella asparagi (Mordv. Induced—Oxidative Stress and Antioxidative Defenses of Asparagus officinalis L.

    Directory of Open Access Journals (Sweden)

    Beata Borowiak-Sobkowiak

    2016-10-01

    Full Text Available The aim of this study was to investigate whether and to what extent oxidative stress is induced in leaves of one- and two-month-old plants of Asparagus officinalis L. cv. Argenteuil infested by Brachycorynella asparagi (Mordvilko at a varied population size. The pest B. asparagi has been described as the most damaging species feeding on asparagus. Analyses using electron paramagnetic resonance (EPR demonstrated generally higher concentrations of semiquinone radicals with g-values of 2.0045 ± 0.0005 and 2.0026 ± 0.0005 in Asparagus officinalis (A. officinalis leaves after Brachycorynella asparagi (B. asparagi infestation than in the control. Observations of leaves under a confocal microscope showed a post-infestation enhanced generation of the superoxide anion radical (O2•− and hydrogen peroxide (H2O2 in comparison to the control. Strong fluctuations in Mn2+ ion levels detected by EPR spectroscopy versus time were detected in leaves infested by aphids, which may indicate the involvement of these ions in the control of O2•− production. An enhanced superoxide dismutase activity is an important element in leaf defense against oxidative stress. Visible symptoms were found in aphid-infested A. officinalis. Damage to leaves of one- and two-month-old A. officinalis plants by the aphid B. asparagi was dependent on the intensity, duration of infestation and plant age.

  20. Shift in aggregation, ROS generation, antioxidative defense, lysozyme and acetylcholinesterase activities in the cells of an Indian freshwater sponge exposed to washing soda (sodium carbonate).

    Science.gov (United States)

    Mukherjee, Soumalya; Ray, Mitali; Ray, Sajal

    2016-09-01

    Washing soda, chemically identified as anhydrous sodium carbonate, is a popular cleaning agent among the rural and urban populations of India which often contaminates the freshwater ponds and lakes, the natural habitat of sponge Eunapius carteri. Present investigation deals with estimation of cellular aggregation, generation of ROS and activities of antioxidant enzymes, lysozyme and acetylcholinesterase in the cells of E. carteri under the environmentally realistic concentrations of washing soda. Prolonged treatment of washing soda inhibited the degree of cellular aggregation. Experimental exposure of 8 and 16mg/l of sodium carbonate for 48h elevated the physiological level of reactive oxygen species (ROS) generation in the agranulocytes, semigranulocytes and granulocytes of E. carteri, whereas, treatment of 192h inhibited the ROS generation in three cellular morphotypes. Activities of superoxide dismutase, catalase and glutathione-S-transferase were recorded to be inhibited under prolonged exposure of washing soda. Washing soda mediated inhibition of ROS generation and depletion in the activities of antioxidant enzymes were indicative to an undesirable shift in cytotoxic status and antioxidative defense in E. carteri. Inhibition in the activity of lysozyme under the treatment of sodium carbonate was suggestive to a severe impairment of the innate immunological efficiency of E. carteri distributed in the washing soda contaminated habitat. Washing soda mediated inhibition in the activity of acetylcholinesterase indicated its neurotoxicity in E. carteri. Washing soda, a reported environmental contaminant, affected adversely the immunophysiological status of E. carteri with reference to cellular aggregation, oxidative stress, antioxidative defense, lysozyme and acetylcholinesterase activity.

  1. 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.

  2. 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...

  3. Serine/threonine protein phosphatases: multi-purpose enzymes in control of defense mechanisms.

    Science.gov (United States)

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

    2011-12-01

    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. 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. Phytohormones play crucial roles not only in the initiation of diverse downstream signaling events in plant defense but also in the activation of effective defenses through an essential process called signaling pathway crosstalk, a mechanism involved in transduction signals between two or more distinct, "linear signal transduction pathways simultaneously activated in the same cell."

  4. ASSOCIATION BETWEEN ENZYMATIC AND NON-ENZYMATIC ANTIOXIDANT DEFENSE WITH ALZHEIMER DISEASE

    Directory of Open Access Journals (Sweden)

    A. Vaisi-Raygani

    2008-04-01

    Full Text Available The etiopathogenesis of dementia in Alzheimer's disease (AD is still unclear. However, long-term oxidative stress is believed to be one of the major contributing factors in progression of neuronal degeneration and decline of cognitive function in AD. In order to assess the presence of oxidative stress in AD, we examined the enzymatic activities of the erythrocyte Cu-Zn superoxide dismutase (Cu-Zn SOD, glutathione peroxidase (GSH-Px, catalase (CAT, and plasma level of total antioxidant status (TAS in AD and control groups (age and sex-matched. The results showed that the Cu-Zn SOD activity was significantly higher and the level of GSH-Px and TAS activities were significantly lower in AD subjects than that in the control group (2111±324 U/grHb, 43.7±11.6 U/grHb, and 1.17 ±0.23 mmol/L compared with 1371±211 U/gHb; t= -2.17, p=0.036, 56.3±9.5 U/gHb; t=3.8, p=0.014, and 1.54±0.2 mmol/L; t=11.18, P<0.001, respectively. While, the erythrocyte CAT activity was lower in AD subjects compared to the control group, the difference was not statistically significant (t=1.3, P=0.15. These findings support the idea that the oxidative stress plays an important role in the pathogenesis underlying AD neurodegeneration. In addition, the enzymatic activity of the erythrocyte Cu-Zn SOD and GSH-Px and the plasma level of TAS can be used as a measure of the oxidative stress and a marker for pathological changes in the brain of patients with AD.

  5. 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.

  6. 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…

  7. 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.

  8. Trichoderma-plant root colonization: escaping early plant defense responses and activation of the antioxidant machinery for saline stress tolerance.

    Science.gov (United States)

    Brotman, Yariv; Landau, Udi; Cuadros-Inostroza, Álvaro; Tohge, Takayuki; Takayuki, Tohge; Fernie, Alisdair R; Chet, Ilan; Viterbo, Ada; Willmitzer, Lothar

    2013-03-01

    Trichoderma spp. are versatile opportunistic plant symbionts which can colonize the apoplast of plant roots. Microarrays analysis of Arabidopsis thaliana roots inoculated with Trichoderma asperelloides T203, coupled with qPCR analysis of 137 stress responsive genes and transcription factors, revealed wide gene transcript reprogramming, proceeded by a transient repression of the plant immune responses supposedly to allow root colonization. Enhancement in the expression of WRKY18 and WRKY40, which stimulate JA-signaling via suppression of JAZ repressors and negatively regulate the expression of the defense genes FMO1, PAD3 and CYP71A13, was detected in Arabidopsis roots upon Trichoderma colonization. Reduced root colonization was observed in the wrky18/wrky40 double mutant line, while partial phenotypic complementation was achieved by over-expressing WRKY40 in the wrky18 wrky40 background. On the other hand increased colonization rate was found in roots of the FMO1 knockout mutant. Trichoderma spp. stimulate plant growth and resistance to a wide range of adverse environmental conditions. Arabidopsis and cucumber (Cucumis sativus L.) plants treated with Trichoderma prior to salt stress imposition show significantly improved seed germination. In addition, Trichoderma treatment affects the expression of several genes related to osmo-protection and general oxidative stress in roots of both plants. The MDAR gene coding for monodehydroascorbate reductase is significantly up-regulated and, accordingly, the pool of reduced ascorbic acid was found to be increased in Trichoderma treated plants. 1-Aminocyclopropane-1-carboxylate (ACC)-deaminase silenced Trichoderma mutants were less effective in providing tolerance to salt stress, suggesting that Trichoderma, similarly to ACC deaminase producing bacteria, can ameliorate plant growth under conditions of abiotic stress, by lowering ameliorating increases in ethylene levels as well as promoting an elevated antioxidative capacity.

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

    OpenAIRE

    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...

  10. Defense mechanisms after brief cognitive-behavior group therapy for panic disorder: one-year follow-up.

    Science.gov (United States)

    Heldt, Elizeth; Blaya, Carolina; Kipper, Leticia; Salum, Giovanni A; Otto, Michael W; Manfro, Gisele G

    2007-06-01

    Changes in defense mechanisms have been shown in long-term psychodynamic treatment. The aim of this study was to examine the changes that occurred after brief cognitive-behavior group therapy in the defense style of panic disorder patients that had failed to respond to pharmacotherapy. Forty-seven patients participated in the study and severity of panic disorder was evaluated by Clinical Global Impression. Defense mechanisms were evaluated by the Defense Style Questionnaire. Patients decreased the use of maladaptive defenses after cognitive-behavior group therapy, and the change in immature defenses was maintained at 1-year follow-up evaluation (p = 0.022). These modifications were associated with reduction of symptoms (F = 0.359; p = 0.047). These findings are consistent with the hypothesis that defense styles are malleable in short-term treatment and are, at least partially, symptom-state dependent.

  11. Glutathione depletion in antioxidant defense of differentiated NT2-LHON cybrids.

    Science.gov (United States)

    Schoeler, S; Winkler-Stuck, K; Szibor, R; Haroon, M F; Gellerich, F N; Chamaon, K; Mawrin, C; Kirches, E

    2007-03-01

    The mechanism of retinal ganglion cell loss in Leber's hereditary optic neuropathy (LHON) is still uncertain, and a role of enhanced superoxide production by the mutant mitochondrial complex I has been hypothesized. In the present study, it was shown that LHON cybrids, carrying the np11778 mutation, became selectively more H(2)O(2) sensitive compared with the parental cell line only following short-term retinoic acid differentiation. They contained a decreased cellular glutathione pool (49%, p< or =0.05), despite 1.5-fold enhanced expression of the regulatory subunit of gamma-glutamylcysteine synthetase (p< or =0.05). This points to a reduction of the capacity to detoxify H(2)O(2) and to changes in thiol redox potential. The activity of the H(2)O(2) degrading enzyme glutathione peroxidase (GPx) and the activities of glutathione reductase (GR) and superoxide dismutase (SOD) were unaffected.

  12. Zinc reduces copper toxicity induced oxidative stress by promoting antioxidant defense in freshly grown aquatic duckweed Spirodela polyrhiza L.

    Science.gov (United States)

    Upadhyay, RishiKesh; Panda, Sanjib Kumar

    2010-03-15

    The mechanism by which Zn promotes Cu toxicity in duckweed Spirodela polyrhiza L. was investigated in order to understand the possible interaction between these two metals. Cu uptake was gradually declined by Zn. The induction of oxidative stress is shown by increased levels of lipid peroxidation, total peroxide, superoxide anion and lipoxygenase activity. Zn interaction reduced the oxidative damage. However, only Zn-treated plants did not show alteration in the above observed parameters. The activities of antioxidant enzymes catalase, ascorbate peroxidase and peroxidase showed a very high increase in activity in Cu+Zn treatment as compared to Cu or Zn alone-treated plants. Thus, this study demonstrates that zinc reversed the effect of copper, combating against Cu induced oxidative damage and improvement of duckweed's growth and toxicity under natural condition.

  13. Response of the antioxidant defense system to tert-butyl hydroperoxide and hydrogen peroxide in a human hepatoma cell line (HepG2).

    Science.gov (United States)

    Alía, Mario; Ramos, Sonia; Mateos, Raquel; Bravo, Laura; Goya, Luis

    2005-01-01

    The aim of this work was to investigate the response of the antioxidant defense system to two oxidative stressors, hydrogen peroxide and tert-butyl hydroperoxide, in HepG2 cells in culture. The parameters evaluated included enzyme activity and gene expression of superoxide dismutase, catalase, glutathione peroxidase, and activity of glutathione reductase. Besides, markers of the cell damage and oxidative stress evoked by the stressors such as cell viability, intracellular reactive oxygen species generation, malondialdehyde levels, and reduced glutathione concentration were evaluated. Both stressors, hydrogen peroxide and tert-butyl hydroperoxide, enhanced cell damage and reactive oxygen species generation at doses above 50 microM. The concentration of reduced glutathione decreased, and levels of malondialdehyde and activity of the antioxidant enzymes consistently increased only when HepG2 cells were treated with tert-butyl hydroperoxide but not when hydrogen peroxide was used. A slight increase in the gene expression of Cu/Zn superoxide dismutase and catalase with 500 microM tert-butyl hydroperoxide and of catalase with 200 microM hydrogen peroxide was observed. The response of the components of the antioxidant defense system evaluated in this study indicates that tert-butyl hydroperoxide evokes a consistent cellular stress in HepG2.

  14. 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.

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

    Science.gov (United States)

    Rahman, Anisur; Mostofa, Mohammad Golam; Alam, Md Mahabub; Nahar, Kamrun; Hasanuzzaman, Mirza; Fujita, Masayuki

    2015-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Naofumi Tamaki

    2016-01-01

    Full Text Available 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.

  17. Exploring uncoupling proteins and antioxidant mechanisms under acute cold exposure in brains of fish.

    Directory of Open Access Journals (Sweden)

    Yung-Che Tseng

    Full Text Available Exposure to fluctuating temperatures accelerates the mitochondrial respiration and increases the formation of mitochondrial reactive oxygen species (ROS in ectothermic vertebrates including fish. To date, little is known on potential oxidative damage and on protective antioxidative defense mechanisms in the brain of fish under cold shock. In this study, the concentration of cellular protein carbonyls in brain was significantly increased by 38% within 1 h after cold exposure (from 28 °C to 18 °C of zebrafish (Danio rerio. In addition, the specific activity of superoxide dismutase (SOD and the mRNA level of catalase (CAT were increased after cold exposure by about 60% (6 h and by 60%-90% (1 and 24 h, respectively, while the specific glutathione content as well as the ratio of glutathione disulfide to glutathione remained constant and at a very low level. In addition, cold exposure increased the protein level of hypoxia-inducible factor (HIF by about 50% and the mRNA level of the glucose transporter zglut3 in brain by 50%-100%. To test for an involvement of uncoupling proteins (UCPs in the cold adaptation of zebrafish, five UCP members were annotated and identified (zucp1-5. With the exception of zucp1, the mRNA levels of the other four zucps were significantly increased after cold exposure. In addition, the mRNA levels of four of the fish homologs (zppar of the peroxisome proliferator-activated receptor (PPAR were increased after cold exposure. These data suggest that PPARs and UCPs are involved in the alterations observed in zebrafish brain after exposure to 18°C. The observed stimulation of the PPAR-UCP axis may help to prevent oxidative damage and to maintain metabolic balance and cellular homeostasis in the brains of ectothermic zebrafish upon cold exposure.

  18. A quorum-sensing-induced bacteriophage defense mechanism

    DEFF Research Database (Denmark)

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

    2013-01-01

    of 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...... 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...

  19. 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

  20. Autophagy is an inflammation-related defensive mechanism against disease.

    Science.gov (United States)

    Joven, Jorge; Guirro, Maria; Mariné-Casadó, Roger; Rodríguez-Gallego, Esther; Menéndez, Javier A

    2014-01-01

    The inflammatory response is an energy-intensive process. Consequently, metabolism is closely associated with immune function. The autophagy machinery plays a role in metabolism by providing energy but may also be used to attack invading pathogens (xenophagy). The autophagy machinery may function to protect against not only the threats of infection but also the threats of the host's own response acting on the central immunological tolerance and the negative regulation of innate and inflammatory signaling. The balance between too little and too much autophagy is critical for the survival of immune cells because autophagy is linked to type 2-cell death programmed necrosis and apoptosis. Changes in inflammatory cells are driven by extracellular signals; however, the mechanisms by which cytokines mediate autophagy regulation and govern immune cell function remain unknown. Certain cytokines increase autophagy, whereas others inhibit autophagy. The relationship between autophagy and inflammation is also important in the pathogenesis of metabolic, non-communicable diseases. Inflammation per se is not the cause of obesity-associated diseases, but it is secondary to both the positive energy balance and the specific cellular responses. In metabolic tissues, the suppression of autophagy increases inflammation with the overexpression of cytokines, resulting in an activation of autophagy. The physiological role of these apparently contradictory findings remains uncertain but exemplifies future challenges in the therapeutic modulation of autophagy in the management of disease.

  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. The C2H2-type Zinc Finger Protein ZFP182 is Involved in Abscisic Acid-Induced Antioxidant Defense in Rice

    Institute of Scientific and Technical Information of China (English)

    Hong Zhang; Lan Ni; Yanpei Liu; Yunfei Wang; Aying Zhang; Mingpu Tan; Mingyi Jiang

    2012-01-01

    C2H2-type zinc finger proteins (ZFPs) are thought to play important roles in modulating the responses of plants to drought,salinity and oxidative stress.However,direct evidence is lacking for the involvement of these ZFPs in abscisic acid (ABA)-induced antioxidant defense in plants.In this study,the role of the rice (Oryza sativa L.sub.japonica cv.Nipponbare) C2H2-type ZFP ZFP182 in ABA-induced antioxidant defense and the relationship between ZFP182 and two rice MAPKs,OsMPK1 and OsMPK5 in ABA signaling were investigated.ABA treatment induced the increases in the expression of ZFP182,OsMPK1 and OsMPK5,and the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in rice leaves.The transient gene expression analysis and the transient RNA interference (RNAi) analysis in protoplasts showed that ZFP182,OsMPK1 and OsMPK5 are involved in ABA-induced up-regulation in the activities of SOD and APX.Besides,OsMPK1 and OsMPK5 were shown to be required for the up-regulation in the expression of ZFP182 in ABA signaling,but ZFP182 did not mediate the ABA-induced up-regulation in the expression of OsMPK1 and OsMPK5.These results indicate that ZFP182 is required for ABA-induced antioxidant defense and the expression of ZFP182 is regulated by rice MAPKs in ABA signaling.

  3. Analysis and utilization of plant antioxidative mechanism by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Haeng-Soon; Kwon, Seock-Yoon; Shin, Seung-Yung [Korea Research Institute of Bioscience and Biotechnology, Taejeon (Korea)

    2001-04-01

    In an attempt to analysis the POD isoenzymes (swpa1, swpa2, swpa3, and swpn1) expression in response to gamma-irradiation in sweet potato. In suspension cells POD isoenzymes was highly expressed at 6 h postirradiation, and the transcript levels increased at 0 and 6 h at 50 Gy in plants. POD isoenzymes expression in response to irradiation appears not to be regulated in a different manner in cultured cells and plants. The gamma radiation-induced changes of proteins in tobacco suspension cells were investigated by SDS-PAGE. In tobacco cultured cells gamma irradiation did not significantly change the protein patterns. This indicates that the gamma irradiation-induced protein was not highly expressed or might be overlap with others. In the tobacco transgenic plants simultaneously expressing SOD and/or APX in chloroplast, the specific activities of SOD and APX of gamma-irradiated plants increased according to the dose of gamma-irradiation. These results indicate that antioxidative genes depends on antioxidative isoenzymes differently respond to gamma irradiation in transgenic tobacco plant lines. 35 refs., 9 figs. (Author)

  4. Isoprenoids and phenylpropanoids are part of the antioxidant defense orchestrated daily by drought-stressed Platanus × acerifolia plants during Mediterranean summers.

    Science.gov (United States)

    Tattini, Massimiliano; Loreto, Francesco; Fini, Alessio; Guidi, Lucia; Brunetti, Cecilia; Velikova, Violeta; Gori, Antonella; Ferrini, Francesco

    2015-08-01

    The hypothesis was tested that isoprenoids and phenylpropanoids play a prominent role in countering photooxidative stress, following the depletion of antioxidant enzyme activity in plants exposed to severe drought stress under high solar irradiance and high temperatures. Platanus × acerifolia, a high isoprene-emitting species, was drought-stressed during summer (WS) and compared with unstressed controls (WW). Water relations and photosynthetic parameters were measured under mild, moderate, and severe drought stress conditions. Volatile and nonvolatile isoprenoids, antioxidant enzymes, and phenylpropanoids were measured with the same time course, but in four different periods of the day. Drought severely inhibited photosynthesis, whereas it did not markedly affect the photochemical machinery. Isoprene emission and zeaxanthin concentration were higher in WS than in WW leaves, particularly at mild and moderate stresses, and during the hottest hours of the day. The activities of catalase and ascorbate peroxidase steeply declined during the day, while the activity of guaiacol peroxidase and the concentration of quercetin increased during the day, peaking in the hottest hours in both WW and WS plants. Our experiment reveals a sequence of antioxidants that were used daily by plants to orchestrate defense against oxidative stress induced by drought and associated high light and high temperature. Secondary metabolites seem valuable complements of antioxidant enzymes to counter oxidative stress during the hottest daily hours.

  5. General beliefs about the world as defensive mechanisms against death anxiety.

    Science.gov (United States)

    Hui, Victoria Ka-Ying; Bond, Michael Harris; Ng, Timmy Sze Wing

    Death ideation and death anxiety represent the cognitive and affective dimensions of death attitudes, respectively. General beliefs about the world are proposed to be useful defensive mechanisms protecting persons against the death anxiety provoked by death ideation. SEM is employed to test the proposed mediation model, using a sample of 133 Hong Kong Chinese university students. Results showed that death ideation was significantly and inversely linked to belief in social cynicism, reward for application, and fate control. Moreover, higher levels of belief in fate control and lower levels of religiosity predicted greater death anxiety. Only belief in fate control partially mediated the relationship between death ideation and death anxiety. Discussion focused on how social axioms serve as useful defensive mechanisms against death anxiety.

  6. Antioxidant properties of phenolic Schiff bases: structure-activity relationship and mechanism of action.

    Science.gov (United States)

    Anouar, El Hassane; Raweh, Salwa; Bayach, Imene; Taha, Muhammad; Baharudin, Mohd Syukri; Di Meo, Florent; Hasan, Mizaton Hazizul; Adam, Aishah; Ismail, Nor Hadiani; Weber, Jean-Frédéric F; Trouillas, Patrick

    2013-11-01

    Phenolic Schiff bases are known for their diverse biological activities and ability to scavenge free radicals. To elucidate (1) the structure-antioxidant activity relationship of a series of thirty synthetic derivatives of 2-methoxybezohydrazide phenolic Schiff bases and (2) to determine the major mechanism involved in free radical scavenging, we used density functional theory calculations (B3P86/6-31+(d,p)) within polarizable continuum model. The results showed the importance of the bond dissociation enthalpies (BDEs) related to the first and second (BDEd) hydrogen atom transfer (intrinsic parameters) for rationalizing the antioxidant activity. In addition to the number of OH groups, the presence of a bromine substituent plays an interesting role in modulating the antioxidant activity. Theoretical thermodynamic and kinetic studies demonstrated that the free radical scavenging by these Schiff bases mainly proceeds through proton-coupled electron transfer rather than sequential proton loss electron transfer, the latter mechanism being only feasible at relatively high pH.

  7. 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.

  8. 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.

  9. When the Guns Fall Silent: a Leader’s Guide to Understanding Defensive Coping Mechanisms

    Science.gov (United States)

    2011-05-19

    with schizoid personality disorder , failure to adjust to normal life Splitting distrust and/or paranoia to persons of authority, isolation, anti-social...patients with personality disorders may be characterized by their most dominant or most rigid mechanism, each patient uses several defenses.”25 The...with borderline personality disorder .62 In adults, this process can involve profound distortions of reality resulting in paranoid

  10. 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.

  11. Molecular mechanisms of insect adaptation to plant defense:Lessons Iearned from a Bruchid beetle

    Institute of Scientific and Technical Information of China (English)

    Keyan Zhu-Salzman; Ren Sen Zeng

    2008-01-01

    Plants can accumulate,constitutively and/or after induction,a wide variety of defense compounds in their tissues that confer resistance to herbivorous insects.The naturally occurring plant resistance gene pool can serve as an arsenal in pest management via transgenic approaches.As insect-plant interaction research rapidly advances,it has gradually become clear that the effects of plant defense compounds ale determined not only by their toxicity toward target sites,but also by how insects respond to the challenge.Insect digestive tracts age not passive targets of plant defense,but often can adapt to dietary challenge and successfully deal with various plant toxins and anti-metabolites.This adaptive response has posed an obstacle to biotechnology-based pest control approaches,which underscores the importance of understanding insect adaptive mechanisms.Molecular studies on the impact of protease inhibitors on insect digestion have contributed significantly to our understanding of insect adaptation to plant defense.This review will focus on exposing how the insect responds to protease inhibitors by both qualitative and quantitative remod-eling of their digestive proteases using the cowpea bruchid-soybean cysteine protease inhibitor N system.

  12. 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.

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

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    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.

  14. Lipid peroxidative damage on Cisplatin exposure and alterations in antioxidant defense system in rat kidneys: a possible protective effect of selenium.

    Science.gov (United States)

    Ognjanović, Branka I; Djordjević, Nataša Z; Matić, Miloš M; Obradović, Jasmina M; Mladenović, Jelena M; Stajn, Andraš Š; Saičić, Zorica S

    2012-01-01

    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 Na(2)SeO(3), 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.

  15. Comparative proteomic analysis of liver antioxidant mechanisms in Megalobrama amblycephala stimulated with dietary emodin.

    Science.gov (United States)

    Song, Changyou; Liu, Bo; Xie, Jun; Ge, Xianping; Zhao, Zhenxin; Zhang, Yuanyuan; Zhang, Huimin; Ren, Mingchun; Zhou, Qunlan; Miao, Linghong; Xu, Pao; Lin, Yan

    2017-01-13

    Oxidative stress is a toxicological endpoint that correlates with the nutrition status of fish through cellular damage, inflammation, and apoptosis. In order to understand the antioxidant mechanism induced by dietary emodin in Megalobrama amblycephala liver, a comparative proteomic analysis was performed to investigate the proteome alteration under emodin administration. 27 altered protein spots were separated under 30 mg kg(-1) emodin stimulation based on 2-DE, and were all successfully identified using MALDI-TOF/TOF, representing 17 unique proteins. These proteins were functionally classified into antioxidant, metabolism, cytoskeleton, chaperone, signal transduction and cofactor groups. Network interaction and Gene Ontology annotation indicated 10 unique proteins were closely related to antioxidation and directly regulated by each other. Compared with the control group, administration of 30 mg kg(-1) emodin significantly increased the antioxidant-related mRNA expressions of GPx1, GSTm and HSP70, but decreased the mRNA expressions of GAPDH and Sord, which was consistent with the protein expression. Nevertheless, Pgk1 and Aldh8a1 were up- and down-regulated, and ALDOB was down- and up-regulated at the mRNA and protein levels, respectively. These results revealed that the altered proteins enhanced antioxidation via complex regulatory mechanisms, and 30 mg kg(-1) emodin was a suitable immunostimulant for M. amblycephala.

  16. 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.

  17. Salmonella proteomics under oxidative stress reveals coordinated regulation of antioxidant defense with iron metabolism and bacterial virulence.

    Science.gov (United States)

    Fu, Jiaqi; Qi, Linlu; Hu, Mo; Liu, Yanhua; Yu, Kaiwen; Liu, Qian; Liu, Xiaoyun

    2017-02-11

    Salmonella Typhimurium is a bacterial pathogen that can cause widespread gastroenteritis. Salmonella encounters reactive oxygen species both under free-living conditions and within their mammalian host during infection. To study its response to oxidative stress, we performed the first large-scale proteomic profiling of Salmonella upon exposure to H2O2. Among 1600 detected proteins, 83 proteins showed significantly altered abundance. Interestingly, only a subset of known antioxidants was induced, likely due to distinct regulatory mechanisms. In addition, we found elevation of several Salmonella acquired phage products with potential contribution to DNA repair under oxidative stress. Furthermore, we observed robust induction of iron-uptake systems and disruption of these pathways led to bacterial survival defects under H2O2 challenge. Importantly, this work is the first to report that oxidative stress severely repressed the Salmonella type III secretion system (T3SS), reducing its virulence. Biological significance Salmonella, a Gram-negative bacterial pathogen, encounters reactive oxygen species (ROS) both endogenously and exogenously. To better understand its response to oxidative stress, we performed the first large-scale profiling of Salmonella protein expression upon H2O2 treatment. Among 1600 quantified proteins, the abundance of 116 proteins was altered significantly. Notably, iron acquisition systems were induced to promote bacterial survival under oxidative stress. Furthermore, we are the first to report that oxidative stress severely repressed Salmonella type III secretion system and hence reduced its virulence. We believe that these findings will not only help us better understand the molecular mechanisms that Salmonella has evolved to counteract ROS but also the global impact of oxidative stress on bacterial physiology.

  18. Polyamine regulates tolerance to water stress in leaves of white clover associated with antioxidant defense and dehydrin genes via involvement in calcium messenger system and hydrogen peroxide signaling

    Directory of Open Access Journals (Sweden)

    Zhou eLi

    2015-10-01

    Full Text Available Endogenous polyamine (PA may play a critical role in tolerance to water stress in plants acting as a signaling molecule activator. Water stress caused increases in endogenous PA content in leaves, including putrescine (Put, spermidine (Spd, and spermine (Spm. Exogenous application of Spd could induce the instantaneous H2O2 burst and accumulation of cytosolic free Ca2+, and activate NADPH oxidase and CDPK gene expression in cells. To a great extent, PA biosynthetic inhibitor reduced the water stress-induced H2O2 accumulation, free cytosolic Ca2+ release, antioxidant enzyme activities and genes expression leading to aggravate water stress-induced oxidative damage, while these suppressing effects were alleviated by the addition of exogenous Spd, indicating PA was involved in water stress-induced H2O2 and cytosolic free Ca2+ production as well as stress tolerance. Dehydrin genes (Y2SK, Y2K, and SK2 were showed to be highly responsive to exogenous Spd. PA-induced antioxidant defense and dehydrin genes expression could be blocked by the scavenger of H2O2 and the inhibitors of H2O2 generation or Ca2+ channels blockers, a calmodulin antagonist, as well as the inhibitor of CDPK. These findings suggested that PA regulated tolerance to water stress in white clover associated with antioxidant defenses and dehydrins via involvement in the calcium messenger system and H2O2 signaling pathways. PA-induced H2O2 production required Ca2+ release, while PA-induced Ca2+ release was also essential for H2O2 production, suggesting an interaction between PA-induced H2O2 and Ca2+ signaling.

  19. 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.

  20. Water vapor permeability, mechanical properties and antioxidant effect of Mexican oregano-soy based edible films.

    Science.gov (United States)

    Pruneda, E; Peralta-Hernández, J M; Esquivel, K; Lee, S Y; Godínez, L A; Mendoza, S

    2008-08-01

    Water-soluble extracts from Mexican oregano (Lippia graveolens) were incorporated into soy protein isolate (SPI) films. Water vapor permeability, mechanical properties, and antioxidant ability were evaluated. All the extracts were capable of scavenging DPPH radicals in a concentration-dependent fashion; the IC50 values were obtained. Oregano extracts were incorporated into SPI films plasticized with sorbitol, glycerol, and glycerol-sorbitol 1:1. The addition of the extracts resulted in an increase in the water vapor permeability values and provided a dark reddish film appearance. Changes in tensile strength as well as elongation values were observed. The oregano SPI films exhibited antioxidant properties in a concentration-dependent fashion.

  1. 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.

  2. Mechanism of bystander-blaming: defensive attribution, counterfactual thinking, and gender.

    Science.gov (United States)

    Levy, Inna; Ben-David, Sarah

    2015-01-01

    Contemporary victimology recognizes that an understanding of the mechanism of blaming requires a comprehensive approach that includes the victim, the offender, and the bystander. However, most of the existing research on blaming focuses on the victim and the offender, ignoring the issue of bystander-blaming. This study highlights the bystander and investigates bystander-blaming by exploring some theoretical explanations, including counterfactual thinking, defensive attribution, and gender differences. The study included 363 young male and female participants, who read vignettes describing the behavior of the victim and the bystander in a rape scenario and answered questions regarding bystander-blaming. The results show that both counterfactual thinking and defensive attribution play a role in bystander-blaming. This article addresses the theoretical and practical implications of these findings.

  3. Molecular mechanisms and in vitro antioxidant effects of Lactobacillus plantarum MA2.

    Science.gov (United States)

    Tang, Wei; Xing, Zhuqing; Li, Chao; Wang, Jinju; Wang, Yanping

    2017-04-15

    Lactobacillus plantarum MA2 was isolated from Chinese traditional Tibetan kefir grains. The antioxidant activities in vitro of this strain were evaluated extensively. The results showed that L. plantarum MA2 can tolerate hydrogen peroxide up to 2.0mM, and its fermentate (fermented supernatant, intact cell and cell-free extract) had strong reducing capacities, lipid peroxidation inhibition capacities, Fe(2+)-chelating abilities, as well as various free radical scavenging capacities. Additionally, both the fermented supernatant and cell homogenate exhibited glutathione peroxidase activity and superoxide dismutase activity. In order to investigate the antioxidant mechanism of L. plantarum MA2 at the molecular level, eight antioxidant-related genes were identified, and further analyzed. Three groups of genes cat, gshR and npx, were found up-regulated under H2O2 challenge.

  4. 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.

  5. Coumarins as Potential Antioxidant Agents Complemented with Suggested Mechanisms and Approved by Molecular Modeling Studies

    Directory of Open Access Journals (Sweden)

    Yasameen K. Al-Majedy

    2016-01-01

    Full Text Available Syntheses of coumarins, which are a structurally interesting antioxidant activity, was done in this article. The modification of 7-hydroxycoumarin by different reaction steps was done to yield target compounds. Molecular structures were characterized by different spectroscopical techniques (Fourier transformation infrared and nuclear magnetic resonance. Antioxidant activities were performed by using various in vitro spectrophometric assays against 1,1-diphenyl-2-picrylhydrazyl (DPPH radical and hydrogen peroxide (H2O2. All compounds exhibited high efficiency as antioxidants compared to ascorbic acid. The highest efficiency scavenging activity was found for compound 3 (91.0 ± 5.0, followed by compounds 2 and 4 (88.0 ± 2.00; and 87.0 ± 3.00. Ascorbic acid C was used as a standard drug with a percentage inhibition of 91.00 ± 1.5. The mechanism of the synthesized compounds as antioxidants was also studied. Hartree–Fock–based quantum chemical studies have been carried out with the basis set to 3-21G, in order to obtain information about the three-dimensional (3D geometries, electronic structure, molecular modeling, and electronic levels, namely HOMO (highest occupied molecular orbital and LUMO (lowest unoccupied molecular orbital, to understand the antioxidant activity for the synthesized compounds.

  6. [Toxicological evaluation of colloidal nano-sized silver stabilized polyvinylpyrrolidone. III. Enzymological, biochemical markers, state of antioxidant defense system].

    Science.gov (United States)

    Gmoshinsky, I V; Shipelin, V A; Vorozhko, I V; Sentsova, T B; Soto, S Kh; Avren'eva, L I; Guseva, G V; Kravchenko, L V; Khotimchenko, S A; Tutelyan, V A

    2016-01-01

    Nanosized colloidal silver (NCS) with primary nanoparticles (NPs) size in the range of 10-80 nm in aqueous suspension was administered to rats with initial weight 80±10 gfor the first 30 day intragastrically and for lasting 62 days with the diet consumed in doses of 0.1; 1.0 and 10 mg/kg of body weight b.w) per day based on silver (Ag). The control animals received deionized water and carrier of NPs - aqueous solution of stabilizer polyvinylpyrrolidone. Activity (Vmax) was determined in liver of microsomal mixed function monooxygenase isoforms CYP 1A1, 1A2 and 2B1 against their specific substrates, the activity of liver conjugating enzymes (glutathione-S-transferase and UDP-glucuronosyltransferase) in the microsomal fraction and a cytosol, and the overall and non-sedimentable activities of lysosomal hydrolases. In blood plasma there were evaluated malonic dialdehyde, PUFA diene conjugates, in erythrocytes - the activity of antioxidant enzymes. A set of standard biochemical indicators of blood serum was also determined. The studies revealed changes in a number of molecular markers of toxic action. Among them - the increase in the activity of key enzymes I and II stages of detoxification of xenobiotics, indicating its functional overvoltage; reducing the activity of glutathione peroxidase (GP), the total arylsulfatase A and B, β-galactosidase (in the absence of changes in their non-sedimentable activity), levels of uric acid, increased alkaline phosphatase activity. These changes occurred mainly at the dose Ag of 10 mg/kg b.w., except for the GP to which the threshold dose was 1 mg/kg b.w. No significant changes in the studied markers in a dose Ag 0,1 mg/kg b.w. were identified. Possible mechanisms of the toxic action of silver NPs are discussed.

  7. Cryptococcus neoformans is resistant to surfactant protein A mediated host defense mechanisms.

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    Steven S Giles

    Full Text Available Initiation of a protective immune response to infection by the pathogenic fungus Cryptococcus neoformans is mediated in part by host factors that promote interactions between immune cells and C. neoformans yeast. Surfactant protein A (SP-A contributes positively to pulmonary host defenses against a variety of bacteria, viruses, and fungi in part by promoting the recognition and phagocytosis of these pathogens by alveolar macrophages. In the present study we investigated the role of SP-A as a mediator of host defense against the pulmonary pathogen, C. neoformans. Previous studies have shown that SP-A binds to acapsular and minimally encapsulated strains of C. neoformans. Using in vitro binding assays we confirmed that SP-A does not directly bind to a fully encapsulated strain of C. neoformans (H99. However, we observed that when C. neoformans was incubated in bronchoalveolar fluid, SP-A binding was detected, suggesting that another alveolar host factor may enable SP-A binding. Indeed, we discovered that SP-A binds encapsulated C. neoformans via a previously unknown IgG dependent mechanism. The consequence of this interaction was the inhibition of IgG-mediated phagocytosis of C. neoformans by alveolar macrophages. Therefore, to assess the contribution of SP-A to the pulmonary host defenses we compared in vivo infections using SP-A null mice (SP-A-/- and wild-type mice in an intranasal infection model. We found that the immune response assessed by cellular counts, TNFalpha cytokine production, and fungal burden in lungs and bronchoalveolar lavage fluids during early stages of infection were equivalent. Furthermore, the survival outcome of C. neoformans infection was equivalent in SP-A-/- and wild-type mice. Our results suggest that unlike a variety of bacteria, viruses, and other fungi, progression of disease with an inhalational challenge of C. neoformans does not appear to be negatively or positively affected by SP-A mediated mechanisms of

  8. [Defense mechanism to prevent ectopic activation of pancreatic digestive enzymes under physiological conditions and its breakdown in acute pancreatitis].

    Science.gov (United States)

    Kaku, Midori; Otsuko, Makoto

    2004-11-01

    Independent of the etiology, acute pancreatitis is associated with significant morbidity and the potential for mortality. In most patients, acute pancreatitis follows an uncomplicated or mild course. Recent studies in hereditary pancreatitis have clearly revealed that trypsin is the key enzyme at the onset of pancreatitis. However, there are several defense mechanisms to prevent ectopic activation of trypsin under physiological conditions. If the defense mechanisms failed or activation of trypsin occurred over defense ability, trypsin would activate other digestive enzymes and self-digestion of the pancreas would occur.

  9. 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

  10. Of Amoebae and Men: Extracellular DNA Traps as an Ancient Cell-Intrinsic Defense Mechanism

    Science.gov (United States)

    Zhang, Xuezhi; Soldati, Thierry

    2016-01-01

    Since the discovery of the formation of DNA-based extracellular traps (ETs) by neutrophils as an innate immune defense mechanism (1), hundreds of articles describe the involvement of ETs in physiological and pathological human and animal conditions [reviewed in Ref. (2), and the previous Frontiers Research Topic on NETosis: http://www.frontiersin.org/books/NETosis_At_the_Intersection_of_Cell_Biology_Microbiology_and_Immunology/195]. Interestingly, a few reports reveal that ETs can be formed by immune cells of more ancient organisms, as far back as the common ancestor of vertebrates and invertebrates (3). Recently, we reported that the Sentinel cells of the multicellular slug of the social amoeba Dictyostelium discoideum also produce ETs to trap and kill slug-invading bacteria [see Box 1; and Figure 1 Ref. (4)]. This is a strong evidence that DNA-based cell-intrinsic defense mechanisms emerged much earlier than thought, about 1.3 billion years ago. Amazingly, using extrusion of DNA as a weapon to capture and kill uningestable microbes has its rationale. During the emergence of multicellularity, a primitive innate immune system developed in the form of a dedicated set of specialized phagocytic cells. This professionalization of immunity allowed the evolution of sophisticated defense mechanisms including the sacrifice of a small set of cells by a mechanism related to NETosis. This altruistic behavior likely emerged in steps, starting from the release of “dispensable” mitochondrial DNA by D. discoideum Sentinel cells. Grounded in this realization, one can anticipate that in the near future, many more examples of the invention and fine-tuning of ETs by early metazoan ancestors will be identified. Consequently, it can be expected that this more complete picture of the evolution of ETs will impact our views of the involvement and pathologies linked to ETs in human and animals. PMID:27458458

  11. 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.

  12. 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.

  13. 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.

  14. Effect of Tridax procumbens on liver antioxidant defense system during lipopolysaccharide-induced hepatitis in D-galactosamine sensitised rats.

    Science.gov (United States)

    Ravikumar, Vilwanathan; Shivashangari, Kanchi Subramanian; Devaki, Thiruvengadam

    2005-01-01

    The present study was carried out to assess the effect of chloroform insoluble fraction of ethanolic extract of Tridax procumbens (TP) against D-Galactosamine/Lipopolysaccharide (D-GalN/LPS)-induced hepatitis in rats. Induction of rats with D-GalN/LPS (300 mg/kg body weight/30 microg/kg body weight) led to a marked increase in lipid peroxidation as measured by thiobarbituric acid reactive substances (TBARS) in liver. Further there was a decline in the activities of enzymic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione s-transferase and the levels of non-enzymic antioxidants namely reduced glutathione, vitamin C and vitamin E. These biochemical alterations were normalised upon pretreatment with TP extract. Thus, the above results suggest that TP (300 mg/kg body weight orally for 10 days) is very effective in allievating the D-GalN/LPS-induced oxidative stress suggesting its antioxidant property.

  15. 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.

  16. The Study of Personality Traits and Defense Mechanism among Prostitutes, Addicted and Normal Women

    Directory of Open Access Journals (Sweden)

    M Seydi

    2014-11-01

    Full Text Available Objective: This study aimed to compare personality traits and defense mechanism among prostitutes, addicted and normal. Method: The research design was causal comparative research design. By available sampling 42 postulates, 45 addicted and 43 normal women selected. Andler and Parker’s Psychological stress resistance questionnaire and NEO personality questionnaire were administered among selected samples. Results: The results showed significant difference between three groups on openness and agreeableness subscales. That is, female prostitutes had lower scores in comparison of two other groups. Conclusion: The results have applied implications.

  17. Cyanobacterial defense mechanisms against foreign DNA transfer and their impact on genetic engineering.

    Science.gov (United States)

    Stucken, Karina; Koch, Robin; Dagan, Tal

    2013-01-01

    Cyanobacteria display a large diversity of cellular forms ranging from unicellular to complex multicellular filaments or aggregates. Species in the group present a wide range of metabolic characteristics including the fixation of atmospheric nitrogen, resistance to extreme environments, production of hydrogen, secondary metabolites and exopolysaccharides. These characteristics led to the growing interest in cyanobacteria across the fields of ecology, evolution, cell biology and biotechnology. The number of available cyanobacterial genome sequences has increased considerably in recent years, with more than 140 fully sequenced genomes to date. Genetic engineering of cyanobacteria is widely applied to the model unicellular strains Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942. However the establishment of transformation protocols in many other cyanobacterial strains is challenging. One obstacle to the development of these novel model organisms is that many species have doubling times of 48 h or more, much longer than the bacterial models E. coli or B. subtilis. Furthermore, cyanobacterial defense mechanisms against foreign DNA pose a physical and biochemical barrier to DNA insertion in most strains. Here we review the various barriers to DNA uptake in the context of lateral gene transfer among microbes and the various mechanisms for DNA acquisition within the prokaryotic domain. Understanding the cyanobacterial defense mechanisms is expected to assist in the development and establishment of novel transformation protocols that are specifically suitable for this group.

  18. 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.

  19. Antioxidant and Vasodilator Activity of Ugni molinae Turcz. (Murtilla) and Its Modulatory Mechanism in Hypotensive Response

    Science.gov (United States)

    Jofré, Ignacio; Pezoa, Cesar; Scheuermann, Erick; Rosalen, Pedro Luiz; Romero, Fernando

    2016-01-01

    Hypertension is a systemic condition with high morbidity and mortality rates worldwide, which poses an increased risk for cardiovascular diseases. In this study, we demonstrated the antioxidant and vasodilator activity of Ugni molinae Turcz. (Murtilla) fruit, a berry native to Chile and proposed models to explain its modulatory mechanism in hypotensive response. Murtilla fruits were cultivated in a germplasm bank and submitted to chemical and biological analyses. The phenolic compounds gallic acid, Catechin, Quercetin-3-β-D-glucoside, Myricetin, Quercetin, and Kaempferol were identified. Murtilla extract did not generate toxic effects on human endothelial cells and had significant antioxidant activity against ROS production, lipid peroxidation, and superoxide anion production. Furthermore, it showed dose-dependent vasodilator activity in aortic rings in the presence of endothelium, whose hypotensive mechanism is partially mediated by nitric oxide synthase/guanylate cyclase and large-conductance calcium-dependent potassium channels. Murtilla fruits might potentially have beneficial effects on the management of cardiovascular diseases. PMID:27688827

  20. Host Defense Mechanisms against Bark Beetle Attack Differ between Ponderosa and Lodgepole Pines

    OpenAIRE

    West, Daniel R; Elisa J. Bernklau; Louis B. Bjostad; William R. Jacobi

    2016-01-01

    Conifer defenses against bark beetle attack include, but are not limited to, quantitative and qualitative defenses produced prior to attack. Our objective was to assess host defenses of lodgepole pine and ponderosa pine from ecotone stands. These stands provide a transition of host species for mountain pine beetle (Dendroctonus ponderosae; MPB). We asked two questions: (1) do the preformed quantitative host defenses (amount of resin) and (2) the preformed qualitative host defenses (monoterpen...

  1. Protection of cells against oxidative stress by nanomolar levels of hydroxyflavones indicates a new type of intracellular antioxidant mechanism.

    Directory of Open Access Journals (Sweden)

    Emanuele Lombardo

    Full Text Available Natural polyphenol compounds are often good antioxidants, but they also cause damage to cells through more or less specific interactions with proteins. To distinguish antioxidant activity from cytotoxic effects we have tested four structurally related hydroxyflavones (baicalein, mosloflavone, negletein, and 5,6-dihydroxyflavone at very low and physiologically relevant levels, using two different cell lines, L-6 myoblasts and THP-1 monocytes. Measurements using intracellular fluorescent probes and electron paramagnetic resonance spectroscopy in combination with cytotoxicity assays showed strong antioxidant activities for baicalein and 5,6-dihydroxyflavone at picomolar concentrations, while 10 nM partially protected monocytes against the strong oxidative stress induced by 200 µM cumene hydroperoxide. Wide range dose-dependence curves were introduced to characterize and distinguish the mechanism and targets of different flavone antioxidants, and identify cytotoxic effects which only became detectable at micromolar concentrations. Analysis of these dose-dependence curves made it possible to exclude a protein-mediated antioxidant response, as well as a mechanism based on the simple stoichiometric scavenging of radicals. The results demonstrate that these flavones do not act on the same radicals as the flavonol quercetin. Considering the normal concentrations of all the endogenous antioxidants in cells, the addition of picomolar or nanomolar levels of these flavones should not be expected to produce any detectable increase in the total cellular antioxidant capacity. The significant intracellular antioxidant activity observed with 1 pM baicalein means that it must be scavenging radicals that for some reason are not eliminated by the endogenous antioxidants. The strong antioxidant effects found suggest these flavones, as well as quercetin and similar polyphenolic antioxidants, at physiologically relevant concentrations act as redox mediators to enable

  2. Guardian of the Human Genome: Host Defense Mechanisms against LINE-1 Retrotransposition

    Science.gov (United States)

    Ariumi, Yasuo

    2016-01-01

    Long interspersed element type 1 (LINE-1, L1) is a mobile genetic element comprising about 17% of the human genome, encoding a newly identified ORF0 with unknown function, ORF1p with RNA-binding activity and ORF2p with endonuclease and reverse transcriptase activities required for L1 retrotransposition. L1 utilizes an endonuclease (EN) to insert L1 cDNA into target DNA, which induces DNA double-strand breaks (DSBs). The ataxia-telangiectasia mutated (ATM) is activated by DSBs and subsequently the ATM-signaling pathway plays a role in regulating L1 retrotransposition. In addition, the host DNA repair machinery such as non-homologous end-joining (NHEJ) repair pathway is also involved in L1 retrotransposition. On the other hand, L1 is an insertional mutagenic agent, which contributes to genetic change, genomic instability, and tumorigenesis. Indeed, high-throughput sequencing-based approaches identified numerous tumor-specific somatic L1 insertions in variety of cancers, such as colon cancer, breast cancer, and hepatocellular carcinoma (HCC). In fact, L1 retrotransposition seems to be a potential factor to reduce the tumor suppressive property in HCC. Furthermore, recent study demonstrated that a specific viral-human chimeric transcript, HBx-L1, contributes to hepatitis B virus (HBV)-associated HCC. In contrast, host cells have evolved several defense mechanisms protecting cells against retrotransposition including epigenetic regulation through DNA methylation and host defense factors, such as APOBEC3, MOV10, and SAMHD1, which restrict L1 mobility as a guardian of the human genome. In this review, I focus on somatic L1 insertions into the human genome in cancers and host defense mechanisms against deleterious L1 insertions. PMID:27446907

  3. 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.

  4. 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.

  5. Determination of chemopreventive role of Foeniculum vulgare and Salvia officinalis infusion on trichloroacetic acid-induced increased serum marker enzymes lipid peroxidation and antioxidative defense systems in rats.

    Science.gov (United States)

    Celik, Ismail; Isik, Ismail

    2008-01-10

    Today's world is increasingly seeking ways to replace the synthetic drugs with the therapeutic power of natural products. This study was designed to investigate the protective effects of Foeniculum vulgare (FV) and Salvia officinalis (SO) waters infusions against carcinogen chemical trichloroacetic acid (TCA)-exposure in rats. The chemopreventive potential of the plant infusions were evaluated by measuring levels of serum marker enzymes [aspartate aminotransferase (AST), alanin aminotransferase (ALT), creatine phosphokinase (CPK), acid phosphatase (ACP), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH)], antioxidant defense systems [Reduced glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase (CAT)] and lipid peroxidation level (Malondialdehyde = MDA) in various tissues of rats. Female Sprague-Dawley rats, weighing 150-200 g, were randomly allotted into four experimental groups. While the control group (A) received only natural spring water, the treatment B group (0.2% TCA) supplied with the drinking water containing 0.2% TCA, the treatment C (TCA + FV infusion) and D (TCA + SO infusion) groups drank the drinking water containing 0.2% TCA and 2.5% the plant grains and leaves ad libitum for 50 days during experiment. At the end of the 50 days experiment, TCA and the plant's infusions caused different affect on the serum marker enzymes, tissues antioxidant defense systems and lipid peroxidation against TCA-exposed in rats with comparison to those of TCA exposed and control rats. According to the results, both TCA and TCA + plants infusions caused a significant increase in serum AST, ALT and CPK activity. Non-enzymic antioxidant GSH level significantly increased in the brain whereas reduced in the erythrocytes and kidney of TCA + FV and TCA + SO as compared to TCA group and control. While MDA content slightly increased in tissues of TCA group in comparison to those of control, significantly

  6. Polyamines confer salt tolerance in mung bean (Vigna radiata L. by reducing sodium uptake, improving nutrient homeostasis, antioxidant defense and methylglyoxal detoxification systems

    Directory of Open Access Journals (Sweden)

    Kamrun Nahar

    2016-07-01

    Full Text Available 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 in improved tissue water and chl content, and better seedling growth.

  7. Nitrate reductase-mediated early nitric oxide burst alleviates oxidative damage induced by aluminum through enhancement of antioxidant defenses in roots of wheat (Triticum aestivum).

    Science.gov (United States)

    Sun, Chengliang; Lu, Lingli; Liu, Lijuan; Liu, Wenjing; Yu, Yan; Liu, Xiaoxia; Hu, Yan; Jin, Chongwei; Lin, Xianyong

    2014-03-01

    • Nitric oxide (NO) is an important signaling molecule involved in the physiological processes of plants. The role of NO release in the tolerance strategies of roots of wheat (Triticum aestivum) under aluminum (Al) stress was investigated using two genotypes with different Al resistances. • An early NO burst at 3 h was observed in the root tips of the Al-tolerant genotype Jian-864, whereas the Al-sensitive genotype Yang-5 showed no NO accumulation at 3 h but an extremely high NO concentration after 12 h. Stimulating NO production at 3 h in the root tips of Yang-5 with the NO donor relieved Al-induced root inhibition and callose production, as well as oxidative damage and ROS accumulation, while elimination of the early NO burst by NO scavenger aggravated root inhibition in Jian-864. • Synthesis of early NO in roots of Jian-864 was mediated through nitrate reductase (NR) but not through NO synthase. Elevated antioxidant enzyme activities were induced by Al stress in both wheat genotypes and significantly enhanced by NO donor, but suppressed by NO scavenger or NR inhibitor. • These results suggest that an NR-mediated early NO burst plays an important role in Al resistance of wheat through modulating enhanced antioxidant defense to adapt to Al stress.

  8. Antioxidant Defense Enzyme Genes and Asthma Susceptibility: Gender-Specific Effects and Heterogeneity in Gene-Gene Interactions between Pathogenetic Variants of the Disease

    Directory of Open Access Journals (Sweden)

    Alexey V. Polonikov

    2014-01-01

    Full Text Available Oxidative stress resulting from an increased amount of reactive oxygen species and an imbalance between oxidants and antioxidants plays an important role in the pathogenesis of asthma. The present study tested the hypothesis that genetic susceptibility to allergic and nonallergic variants of asthma is determined by complex interactions between genes encoding antioxidant defense enzymes (ADE. We carried out a comprehensive analysis of the associations between adult asthma and 46 single nucleotide polymorphisms of 34 ADE genes and 12 other candidate genes of asthma in Russian population using set association analysis and multifactor dimensionality reduction approaches. We found for the first time epistatic interactions between ADE genes underlying asthma susceptibility and the genetic heterogeneity between allergic and nonallergic variants of the disease. We identified GSR (glutathione reductase and PON2 (paraoxonase 2 as novel candidate genes for asthma susceptibility. We observed gender-specific effects of ADE genes on the risk of asthma. The results of the study demonstrate complexity and diversity of interactions between genes involved in oxidative stress underlying susceptibility to allergic and nonallergic asthma.

  9. Microglia antioxidant systems and redox signaling

    DEFF Research Database (Denmark)

    Vilhardt, F; Haslund-Vinding, J; Jaquet, V;

    2017-01-01

    't stand alone however, and are not always pernicious. We discuss in general terms, and where available in microglia, GSH synthesis and relation to cystine import and glutamate export, and the thioredoxin system as the most important antioxidative defense mechanism, and further, we discuss in the context...

  10. Salicylic acid alleviates cadmium-induced inhibition of growth and photosynthesis through upregulating antioxidant defense system in two melon cultivars (Cucumis melo L.).

    Science.gov (United States)

    Zhang, Yongping; Xu, Shuang; Yang, Shaojun; Chen, Youyuan

    2015-05-01

    Cadmium (Cd) is a widespread toxic heavy metal that usually causes deleterious effects on plant growth and development. Salicylic acid (SA), a naturally existing phenolic compound, is involved in specific responses to various environmental stresses. To explore the role of SA in the tolerance of melon (Cucumis melo L.) to Cd stress, the influence of SA application on the growth and physiological processes was compared in the two melon cultivars Hamilv (Cd-tolerant) and Xiulv (Cd-sensitive) under Cd stress. Under 400-μM Cd treatment, Hamilv showed a higher biomass accumulation, more chlorophyll (Chl), greater photosynthesis, and less oxidative damage compared to Xiulv. Foliar spraying of 0.1 mM SA dramatically alleviated Cd-induced growth inhibition in the two melon genotypes. Simultaneously, SA pretreatment attenuated the decrease in Chl content, photosynthetic capacity, and PSII photochemistry efficiency in Cd-stressed plants. Furthermore, exogenous SA significantly reduced superoxide anion production and lipid peroxidation, followed by increase in the activities of antioxidant enzyme superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase, and content of soluble protein and free proline in both the genotypes under Cd stress. The effect of SA was more conspicuous in Xiulv than Hamilv, reflected in the biomass, photosynthetic pigments, stomatal conductance, water use efficiency, and antioxidant enzymes. These results suggest that exogenous spray of SA can alleviate the adverse effects of Cd on the growth and photosynthesis of both the melon cultivars, mostly through promoting antioxidant defense capacity. It also indicates that SA-included protection against Cd damage is to a greater extent more pronounced in Cd-sensitive genotype than Cd-tolerant genotype.

  11. Diabetic beta-cells can achieve self-protection against oxidative stress through an adaptive up-regulation of their antioxidant defenses.

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    Grégory Lacraz

    Full Text Available BACKGROUND: Oxidative stress (OS, through excessive and/or chronic reactive oxygen species (ROS, is a mediator of diabetes-related damages in various tissues including pancreatic beta-cells. Here, we have evaluated islet OS status and beta-cell response to ROS using the GK/Par rat as a model of type 2 diabetes. METHODOLOGY/PRINCIPAL FINDINGS: Localization of OS markers was performed on whole pancreases. Using islets isolated from 7-day-old or 2.5-month-old male GK/Par and Wistar control rats, 1 gene expression was analyzed by qRT-PCR; 2 insulin secretion rate was measured; 3 ROS accumulation and mitochondrial polarization were assessed by fluorescence methods; 4 antioxidant contents were quantified by HPLC. After diabetes onset, OS markers targeted mostly peri-islet vascular and inflammatory areas, and not islet cells. GK/Par islets revealed in fact protected against OS, because they maintained basal ROS accumulation similar or even lower than Wistar islets. Remarkably, GK/Par insulin secretion also exhibited strong resistance to the toxic effect of exogenous H(2O(2 or endogenous ROS exposure. Such adaptation was associated to both high glutathione content and overexpression (mRNA and/or protein levels of a large set of genes encoding antioxidant proteins as well as UCP2. Finally, we showed that such a phenotype was not innate but spontaneously acquired after diabetes onset, as the result of an adaptive response to the diabetic environment. CONCLUSIONS: The GK/Par model illustrates the effectiveness of adaptive response to OS by beta-cells to achieve self-tolerance. It remains to be determined to what extend such islet antioxidant defenses upregulation might contribute to GK/Par beta-cell secretory dysfunction.

  12. Contrasting Potato Foliage and Tuber Defense Mechanisms against the Late Blight Pathogen Phytophthora infestans.

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    Liangliang Gao

    Full Text Available The late blight pathogen Phytophthora infestans can attack both potato foliage and tubers. When inoculated with P. infestans, foliage of nontransformed 'Russet Burbank' (WT develops late blight disease while that of transgenic 'Russet Burbank' line SP2211 (+RB does not. We compared the foliar transcriptome responses of these two lines to P. infestans inoculation using an RNA-seq approach. A total of 515 million paired end RNA-seq reads were generated, representing the transcription of 29,970 genes. We also compared the differences and similarities of defense mechanisms against P. infestans in potato foliage and tubers. Differentially expressed genes, gene groups and ontology bins were identified to show similarities and differences in foliage and tuber defense mechanisms. Our results suggest that R gene dosage and shared biochemical pathways (such as ethylene and stress bins contribute to RB-mediated incompatible potato-P. infestans interactions in both the foliage and tubers. Certain ontology bins such as cell wall and lipid metabolisms are potentially organ-specific.

  13. Hepatocyte-mediated cytotoxicity and host defense mechanisms in the alcohol-injured liver.

    Science.gov (United States)

    McVicker, Benita L; Thiele, Geoffrey M; Tuma, Dean J; Casey, Carol A

    2014-09-01

    The consumption of alcohol is associated with many health issues including alcoholic liver disease (ALD). The natural history of ALD involves the development of steatosis, inflammation (steatohepatitis), fibrosis and cirrhosis. During the stage of steatohepatitis, the combination of inflammation and cellular damage can progress to a severe condition termed alcoholic hepatitis (AH). Unfortunately, the pathogenesis of AH remains uncharacterized. Some modulations have been identified in host defense and liver immunity mechanisms during AH that highlight the role of intrahepatic lymphocyte accumulation and associated inflammatory cytokine responses. Also, it is hypothesized that alcohol-induced injury to liver cells may significantly contribute to the aberrant lymphocytic distribution that is seen in AH. In particular, the regulation of lymphocytes by hepatocytes may be disrupted in the alcoholic liver resulting in altered immunologic homeostasis and perpetuation of disease. In recent studies, it was demonstrated that the direct killing of activated T lymphocytes by hepatocytes is facilitated by the asialoglycoprotein receptor (ASGPR). The ASGPR is a well-characterized glycoprotein receptor that is exclusively expressed by hepatocytes. This hepatic receptor is known for its role in the clearance of desialylated glycoproteins or cells, yet neither its physiological function nor its role in disease states has been determined. Interestingly, alcohol markedly impairs ASGPR function; however, the effect alcohol has on ASGPR-mediated cytotoxicity of lymphocytes remains to be elucidated. This review discusses the contribution of hepatocytes in immunological regulation and, importantly, how pathological effects of ethanol disrupt hepatocellular-mediated defense mechanisms.

  14. Biomembrane interactions reveal the mechanism of action of surface-immobilized host defense IDR-1010 peptide.

    Science.gov (United States)

    Gao, Guangzheng; Cheng, John T J; Kindrachuk, Jason; Hancock, Robert E W; Straus, Suzana K; Kizhakkedathu, Jayachandran N

    2012-02-24

    Dissecting the mechanism of action of surface-tethered antimicrobial and immunomodulatory peptides is critical to the design of optimized anti-infection coatings on biomedical devices. To address this, we compared the biomembrane interactions of host defense peptide IDR-1010cys (1) in free form, (2) as a soluble polymer conjugate, and (3) with one end tethered to a solid support with model bacterial and mammalian lipid membranes. Our results show that IDR-1010cys in all three distinct forms interacted with bacterial and mammalian lipid vesicles, but the extent of the interactions as monitored by the induction of secondary structure varied. The enhanced interaction of surface-tethered peptides is well correlated with their very good antimicrobial activities. Our results demonstrate that there may be a difference in the mechanism of action of surface-tethered versus free IDR-1010cys.

  15. 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)

  16. The evolution of advanced mechanical defenses and potential technological applications of diatom shells.

    Science.gov (United States)

    Hamm, Christian E

    2005-01-01

    Diatoms are unicellular algae with silicified cell walls, which exhibit a high degree of symmetry and complexity. Their diversity is extraordinarily high; estimates suggest that about 10(5) marine and limnic species may exist. Recently, it was shown that diatom frustules are mechanically resilient, statically sophisticated structures made of a tough glass-like composite. Consequently, to break the frustules, predators have to generate large forces and invest large amounts of energy. In addition, they need feeding tools (e.g., mandibles or gastric mills) which are hard, tough, and resilient enough to resist high stress and wear, which are bound to occur when they feed on biomineralized objects such as diatoms or other biomineralized protists. Indeed, many copepods feeding on diatoms possess, in analogy to the enamelcoated teeth of mammals, amazingly complex, silica-laced mandibles. The highly developed adaptations both to protect and to break diatoms indicate that selection pressure is high to optimize material properties and the geometry of the shells to achieve mechanical strength of the overall structure. This paper discusses the mechanical challenges which force the development of mechanical defenses, and the structural components of the diatom frustules which indicate that evolutionary optimization has led to mechanically sophisticated structures. Understanding the diatom frustule from the nanometer scale up to the whole shell will provide new insights to advanced combinations of nanostructured composite ceramic materials and lightweight architecture for technological applications.

  17. 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.

  18. 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.

  19. 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.

  20. Oxidative stress, mitochondrial abnormalities and antioxidant defense in Ataxia-telangiectasia, Bloom syndrome and Nijmegen breakage syndrome

    Directory of Open Access Journals (Sweden)

    Mateusz Maciejczyk

    2017-04-01

    Full Text Available Rare pleiotropic genetic disorders, Ataxia-telangiectasia (A-T, Bloom syndrome (BS and Nijmegen breakage syndrome (NBS are characterised by immunodeficiency, extreme radiosensitivity, higher cancer susceptibility, premature aging, neurodegeneration and insulin resistance. Some of these functional abnormalities can be explained by aberrant DNA damage response and chromosomal instability. It has been suggested that one possible common denominator of these conditions could be chronic oxidative stress caused by endogenous ROS overproduction and impairment of mitochondrial homeostasis. Recent studies indicate new, alternative sources of oxidative stress in A-T, BS and NBS cells, including NADPH oxidase 4 (NOX4, oxidised low-density lipoprotein (ox-LDL or Poly (ADP-ribose polymerases (PARP. Mitochondrial abnormalities such as changes in the ultrastructure and function of mitochondria, excess mROS production as well as mitochondrial damage have also been reported in A-T, BS and NBS cells. A-T, BS and NBS cells are inextricably linked to high levels of reactive oxygen species (ROS, and thereby, chronic oxidative stress may be a major phenotypic hallmark in these diseases. Due to the presence of mitochondrial disturbances, A-T, BS and NBS may be considered mitochondrial diseases. Excess activity of antioxidant enzymes and an insufficient amount of low molecular weight antioxidants indicate new pharmacological strategies for patients suffering from the aforementioned diseases. However, at the current stage of research we are unable to ascertain if antioxidants and free radical scavengers can improve the condition or prolong the survival time of A-T, BS and NBS patients. Therefore, it is necessary to conduct experimental studies in a human model.

  1. [Metabolism, intensity of lipid peroxidation and the antioxidant defense system in humans during chamber experiments with long-term isolation].

    Science.gov (United States)

    Markin, A A; Stroganova, L B; Vostrikova, L V; Balashov, O I; Nichiporuk, I A

    1997-01-01

    Blood biochemical parameters of lipid, protein, carbohydrate and energy metabolism were measured in a 135-day chamber experiment. Also, dynamics of the intensity of lipid peroxidation and status of the antioxidant defence system were evaluated. Results of the investigation showed that extended chamber isolation led to modifications of several biochemical parameters including hemoglobin, bilirubin, cholesterol and its fractions, elevated transaminase activity which are typical for long-term space mission. However, these were not accompanied by substantive changes in protein, energy and carbohydrate metabolisms, or intensity of free radical processes. Effects of prolonged stay in chamber was successfully counterbalanced by organism.

  2. Grain and bean lysates improve function of endothelial progenitor cells from human peripheral blood: involvement of the endogenous antioxidant defenses.

    Directory of Open Access Journals (Sweden)

    Daniela Lucchesi

    Full Text Available Increased oxidative stress contributes to the functional impairment of endothelial progenitor cells (EPCs, the pivotal players in the servicing of the endothelial cell lining. Several evidences suggest that decreasing oxidative stress by natural compounds with antioxidant properties may improve EPCs bioactivity. Here, we investigated the effects of Lisosan G (LG, a Triticum Sativum grain powder, and Lady Joy (LJ, a bean lysate, on function of EPCs exposed to oxidative stress. Peripheral blood mononuclear cells were isolated and plated on fibronectin-coated culture dishes; adherent cells, identified as early EPCs, were pre-treated with different concentrations of LG and LJ and incubated with hydrogen peroxide (H2O2. Viability, senescence, adhesion, ROS production and antioxidant enzymes gene expression were evaluated. Lysate-mediated Nrf-2 (nuclear factor (erythroid-derived 2-like 2/ARE (antioxidant response element activation, a modulator of oxidative stress, was assessed by immunocytochemistry. Lady Joy 0.35-0.7 mg/ml increases EPCs viability; pre-treatment with either LG 0.7 mg/ml and LJ 0.35-0.7 mg/ml protect EPCs viability against H2O2-induced injury. LG 0.7 and LJ 0.35-0.7 mg/ml improve EPCs adhesion; pre-treatment with either LG 0.35 and 0.7 mg/ml or LJ 0.35, 0.7 and 1.4 mg/ml preserve adhesiveness of EPCs exposed to H2O2. Senescence is attenuated in EPCs incubated with lysates 0.35 mg/ml. After exposure to H2O2, LG pre-treated cells show a lower senescence than untreated EPCs. Lysates significantly decrease H2O2-induced ROS generation. Both lysates increase glutathione peroxidase-1 and superoxide dismutase-2 (SOD-2 expression; upon H2O2 exposure, pre-treatment with LJ allows higher SOD-2 expression. Heme oxigenase-1 increases in EPCs pre-treated with LG even upon H2O2 exposure. Finally, incubation with LG 0.7 mg/ml results in Nrf-2 translocation into the nucleus both at baseline and after the oxidative challenge. Our data suggest a

  3. 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.

  4. Crocus sativus L. (saffron) attenuates isoproterenol-induced myocardial injury via preserving cardiac functions and strengthening antioxidant defense system.

    Science.gov (United States)

    Sachdeva, Jaspreet; Tanwar, Vineeta; Golechha, Mahaveer; Siddiqui, Khalid M; Nag, Tapas C; Ray, Ruma; Kumari, Santosh; Arya, Dharamvir S

    2012-09-01

    Saffron (dried stigmas of Crocus sativus L.), a naturally derived plant product, has long been used as a traditional ancient medicine against various human diseases. The aim of the series of experiments was to systematically determine whether saffron exerts cardioprotection in isoproterenol-induced myocardial damage. Male Wistar rats (150-175 g) were divided into five groups: control, isoproterenol (ISO) and three saffron (200, 400 and 800 mg/kg) treatment groups. Aqueous extract of saffron or vehicle was administered orally to rats for four weeks. On days 28 and 29, the animals in ISO and saffron treatment groups were administered ISO (85 mg/kg, s.c.) at an interval of 24 h. On day 30, after recording hemodynamics and left ventricular functions, animals were sacrificed for biochemical, histopathological and electromicroscopical examinations. Isoproterenol challenged animals showed depressed hemodynamics and left ventricular functions as evident by decreased left ventricular rate of peak positive and negative pressure change and elevated left ventricular end-diastolic pressure. Structural and ultrastructural studies further confirmed the damage which was reconfirmed by increased thiobarbituric acid reactive substances (psaffron at all the doses exerted significant cardioprotective effect by preserving hemodynamics and left ventricular functions, maintaining structural integrity and augmenting antioxidant status. Among the different doses used, saffron at 400mg/kg dose exhibited maximum protective effects which could be due to maintenance of the redox status of the cell reinforcing its role as an antioxidant.

  5. Study of Reputation Based Defense Mechanism in Peer To Peer Live Streaming

    Directory of Open Access Journals (Sweden)

    M. A. Mottalib

    2011-11-01

    Full Text Available Peer-to-peer live video streaming systems are having more popularity as the information technology is advancing fast. Peer-to-peer live video streaming systems are like peer-to-peer file sharing system and they are also vulnerable to content pollution attack as file sharing. In this type of attack, the attacker mixes polluted or unnecessary data into the streaming data and forwards the polluted data to normal peers and hence the perceived video quality is decreased. In this paper, a comparative study is conducted among three defense mechanisms against pollution attack in peer-to-peer live streaming systems: Blacklisting, Simple Decentralized Reputation System and Bayesian Approach to Reputation System. Finally performance analysis and the derived result has been presented.

  6. Comparison of pulmonary defense mechanisms in Rocky Mountain bighorn (Ovis canadensis canadensis) and domestic sheep.

    Science.gov (United States)

    Silflow, R M; Foreyt, W J; Taylor, S M; Laegreid, W W; Liggitt, H D; Leid, R W

    1989-10-01

    Alveolar macrophages were obtained from Rocky Mountain bighorn sheep (Ovis canadensis canadensis) and domestic sheep for the purpose of comparing pulmonary host defense mechanisms in the two species. Specific variables studied included (1) characterization of the cell types present in the lung, (2) alveolar macrophage phagocytic and bactericidal functions, (3) measurement of protein levels in lavage fluid, and (4) measurement of cortisol levels in lavage fluid. While phagocytic cell populations were similar between bighorn and domestic sheep, a significantly higher percentage of lymphocytes were present in bighorns than domestics (20% in bighorn versus 6% in domestic sheep). Significant differences were not observed in the phagocytic or bactericidal functions of macrophages between the two species. Significant differences were not observed in either lavage fluid protein levels or in cortisol levels.

  7. Linear systems analysis of activating processes of complement system as a defense mechanism.

    Science.gov (United States)

    Hirayama, H; Yoshii, K; Ojima, H; Kawai, N; Gotoh, S; Fukuyama, Y

    1996-01-01

    The complement system is an important element of the host defense mechanism, although its kinetics and characteristics as a system are still unclear. We have investigated its temporal changes and system properties from the view point of system engineering. The temporal changes of sequential activating processes of the system were expressed by 26 non-linear differential equations using reported values of rate constants and serum concentration for each component. The intermediate products in the activating processes increased parabolically while the membrane attack component as the final product, increased linearly. The little change in inactive precursors afforded validity for system linearization. Linear systems analysis revealed that the system which was insensitive to the changes in rate constants was unstable. The system became stable when the feed-back input from the final product was set to operate on the first step of the activating processes. Seven uncontrollable variables were insensitive to changes in rate constants or system optimization that minimized the changes in concentrations of components in the complement system. The singular values of the complement system were reduced and the impulse responses of the system were improved when the system was optimized. When stronger minimization was imposed on the changes of concentration of the components in the complement system, the singular values were reduced more, the magnitude of the impulse responses was depressed further and the responses terminated earlier than those when the elements in the weighting matrix of concentration of the components were set to be unity. By this potent minimization, the influences of changes in rate constants on the singular values were diminished. The present theoretical analysis is presented to evaluate the ability of defense mechanism of complement system.

  8. Antioxidant properties of proanthocyanidins of Uncaria tomentosa bark decoction: a mechanism for anti-inflammatory activity.

    Science.gov (United States)

    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 ability and its phenolic composition. We observed that the decoction prepared according to the traditional Peruvian medicine presented a potent radical scavenger activity, as suggested by its high capacity to reduce the free radical diphenylpicrylhydrazyl, and by its reaction with superoxide anion, peroxyl and hydroxyl radicals as well as with the oxidant species, hydrogen peroxide and hypochlorous acid. It also protected membrane lipids against peroxidation induced by the iron/ascorbate system, as evaluated by the formation of thiobarbituric acid-reactive substances (TBARs). The decoction phenolic profile was established by chromatographic analysis (HPLC/DAD and TLC) revealing essentially the presence of proanthocyanidins (oligomeric procyanidins) and phenolic acids, mainly caffeic acid. Thus, our results provide evidence for an antioxidant mechanism underlying the anti-inflammatory activity of cat's claw and support some of the biological effects of proanthocyanidins, more exactly its antioxidant and radical scavenging activities.

  9. 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.

  10. Anti-oxidation mechanism of SiC-B4C-C composites

    Institute of Scientific and Technical Information of China (English)

    LIU Qi-cheng; XU Xie-wen; HUANG Qi-zhong; HUANG Bai-yun

    2005-01-01

    Mixture of green petroleum coke, B4C and SiC together with short carbon fiber were employed as starting materials, the mixture was press-formed without any binder after grinding, dense and homogeneous binderless SiC-B4C-C(carbon/ceramic) composites were then obtained after sintering. Composites thus prepared possess excellent anti-oxidation property, that is, mass loss less than 1% within the temperature range from 900 to 1100℃ for 10h. Anti-oxidation mechanism was also discussed from the viewpoint of thermodynamics, excellent anti-oxidation property of materials thus prepared can be discribed to 1) solid SiO2 formed from SiC, which restrains the filtering of oxygen and simultaneously, its volume expansion brought about by the reaction takes roles both walling up the original pores and making the material more compact; 2) liquid B2O3 from the reaction of B4C not only makes the combination with C, B4C and SiC tighter through forming solid solution, but also effect of reaction SiC(s)+2CO(g)=SiO2(s)+3C(s) is an expansive process, which improves the microstructure of the material.

  11. Phenylpropanoid Glycoside Analogues: Enzymatic Synthesis, Antioxidant Activity and Theoretical Study of Their Free Radical Scavenger Mechanism

    Science.gov (United States)

    López-Munguía, Agustín; Hernández-Romero, Yanet; Pedraza-Chaverri, José; Miranda-Molina, Alfonso; Regla, Ignacio; Martínez, Ana; Castillo, Edmundo

    2011-01-01

    Phenylpropanoid glycosides (PPGs) are natural compounds present in several medicinal plants that have high antioxidant power and diverse biological activities. Because of their low content in plants (less than 5% w/w), several chemical synthetic routes to produce PPGs have been developed, but their synthesis is a time consuming process and the achieved yields are often low. In this study, an alternative and efficient two-step biosynthetic route to obtain natural PPG analogues is reported for the first time. Two galactosides were initially synthesized from vanillyl alcohol and homovanillyl alcohol by a transgalactosylation reaction catalyzed by Kluyveromyces lactis β-galactosidase in saturated lactose solutions with a 30%–35% yield. To synthesize PPGs, the galactoconjugates were esterified with saturated and unsaturated hydroxycinnamic acid derivatives using Candida antarctica Lipase B (CaL-B) as a biocatalyst with 40%–60% yields. The scavenging ability of the phenolic raw materials, intermediates and PPGs was evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) method. It was found that the biosynthesized PPGs had higher scavenging abilities when compared to ascorbic acid, the reference compound, while their antioxidant activities were found similar to that of natural PPGs. Moreover, density functional theory (DFT) calculations were used to determine that the PPGs antioxidant mechanism proceeds through a sequential proton loss single electron transfer (SPLET). The enzymatic process reported in this study is an efficient and versatile route to obtain PPGs from different phenylpropanoid acids, sugars and phenolic alcohols. PMID:21674039

  12. Mitochondrial Targeted Antioxidant in Cerebral Ischemia.

    Science.gov (United States)

    Ahmed, Ejaz; Donovan, Tucker; Yujiao, Lu; Zhang, Quanguang

    There has been much evidence suggesting that reactive oxygen species (ROS) generated in mitochondria during cerebral ischemia play a major role in programming the senescence of organism. Antioxidants dealing with mitochondria slow down the appearance and progression of symptoms in cerebral ischemia and increase the life span of organisms. The mechanisms of mitochondrial targeted antioxidants, such as SKQ1, Coenzyme Q10, MitoQ, and Methylene blue, include increasing adenosine triphosphate (ATP) production, decreasing production of ROS and increasing antioxidant defenses, providing benefits in neuroprotection following cerebral ischemia. A number of studies have shown the neuroprotective role of these mitochondrial targeted antioxidants in cerebral ischemia. Here in this short review we have compiled the literature supporting consequences of mitochondrial dysfunction, and the protective role of mitochondrial targeted antioxidants.

  13. Effect of Zinc Supplementation on Antioxidant Defenses and Oxidative Stress Markers in Patients Undergoing Chemotherapy for Colorectal Cancer: a Placebo-Controlled, Prospective Randomized Trial.

    Science.gov (United States)

    Ribeiro, Sofia Miranda de Figueiredo; Braga, Camila Bitu Moreno; Peria, Fernanda Maris; Domenici, Fernanda Aparecida; Martinez, Edson Zangiacomi; Feres, Omar; da Rocha, José Joaquim Ribeiro; da Cunha, Selma Freire de Carvalho

    2016-01-01

    The study aimed to investigate the effect of oral zinc supplementation on antioxidant defenses and oxidative stress markers during chemotherapy for colorectal cancer. Twenty-four patients who had undergone surgical resection of colorectal cancer participated in this placebo-controlled, prospective randomized study. The supplementation was started in the perioperative period, in which 10 patients received 70 mg of zinc (zinc group, n = 10) and 14 patients received placebo (placebo group, n = 14) for 16 weeks. Approximately 45 days after surgical resection of tumor, all patients received a chemotherapeutic regimen (capecitabine, capecitabine combined with oxaliplatin or 5-fluorouracil). Vitamin C, vitamin E, antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), and lipid peroxidation markers malondialdehyde (MDA) and 8-isoprostane were determined before the first, second, third, and fourth chemotherapy cycles. Compared with the placebo group, the zinc group presented higher SOD values before the first, second, and fourth chemotherapy cycles and lower GPx values before the third cycle. There were no statistical differences between the study groups in vitamin C, vitamin E, MDA, or 8-isoprostane plasma values. Longitudinal analysis revealed decreased vitamin E concentration in the placebo group before the second and fourth cycles as compared with the initial values. Zinc supplementation during chemotherapy cycles increased SOD activity and maintained vitamin E concentrations. Although no effect of zinc supplementation on oxidative stress markers was observed, the increase in SOD activity indicates a production of stable free radicals, which may have a positive effect in cancer treatment.

  14. The protective role of DJ-1 in ultraviolet-induced damage of human skin: DJ-1 levels in the stratum corneum as an indicator of antioxidative defense.

    Science.gov (United States)

    Ishiwatari, Shioji; Takahashi, Minako; Yasuda, Chie; Nakagawa, Maho; Saito, Yoshiro; Noguchi, Noriko; Matsukuma, Shoko

    2015-12-01

    DJ-1 is a multifunctional protein associated with Parkinson's disease and plays a significant role in protecting nerve cells from oxidative stress. DJ-1 is expressed in the skin, although its function there is unknown. In this study, we investigated DJ-1 function in keratinocytes. DJ-1 was induced by H2O2 exposure and UV irradiation in keratinocytes. DJ-1 knockdown with small interfering RNA (siRNA) increased reactive oxygen species (ROS) and lactate dehydrogenase (LDH) release after UVB irradiation, suggesting that DJ-1 reduces ROS and might protect skin cells from UV damage in vitro. To investigate the in vivo role of DJ-1 in the skin, we determined DJ-1 levels in human stratum corneum samples obtained by the tape-stripping method. DJ-1 levels in the stratum corneum (scDJ-1) correlated with total antioxidant capacity. We also examined the effect of scDJ-1 on changes in skin after UVB irradiation. DJ-1 was elevated in SC from the upper arm 1 to 2 weeks after UVB irradiation. One day after UVB irradiation, L* (brightness) and a* (redness) values, indicators of skin color, were altered regardless of scDJ-1 expression. However, these values recovered more quickly in subjects with high scDJ-1 expression than in those with low scDJ-1 expression. These data suggest that DJ-1 in skin plays a significant role in protection against UV radiation and oxidative stress, and that DJ-1 levels in the SC might be an indicator of antioxidative defense against UV-induced damage.

  15. X-box binding protein 1 is essential for the anti-oxidant defense and cell survival in the retinal pigment epithelium.

    Directory of Open Access Journals (Sweden)

    Yimin Zhong

    Full Text Available Damage to the retinal pigment epithelium (RPE is an early event in the pathogenesis of age-related macular degeneration (AMD. X-box binding protein 1 (XBP1 is a key transcription factor that regulates endoplasmic reticulum (ER homeostasis and cell survival. This study aimed to delineate the role of endogenous XBP1 in the RPE. Our results show that in a rat model of light-induced retinal degeneration, XBP1 activation was suppressed in the RPE/choroid complex, accompanied by decreased anti-oxidant genes and increased oxidative stress. Knockdown of XBP1 by siRNA resulted in reduced expression of SOD1, SOD2, catalase, and glutathione synthase and sensitized RPE cells to oxidative damage. Using Cre/LoxP system, we generated a mouse line that lacks XBP1 only in RPE cells. Compared to wildtype littermates, RPE-XBP1 KO mice expressed less SOD1, SOD2, and catalase in the RPE, and had increased oxidative stress. At age 3 months and older, these mice exhibited apoptosis of RPE cells, decreased number of cone photoreceptors, shortened photoreceptor outer segment, reduced ONL thickness, and deficit in retinal function. Electron microscopy showed abnormal ultrastructure, Bruch's membrane thickening, and disrupted basal membrane infolding in XBP1-deficient RPE. These results indicate that XBP1 is an important gene involved in regulation of the anti-oxidant defense in the RPE, and that impaired activation of XBP1 may contribute to RPE dysfunction and cell death during retinal degeneration and AMD.

  16. A teleostan homolog of catalase from black rockfish (Sebastes schlegelii): insights into functional roles in host antioxidant defense and expressional responses to septic conditions.

    Science.gov (United States)

    Elvitigala, Don Anushka Sandaruwan; Priyathilaka, Thanthrige Thiunuwan; Whang, Ilson; Nam, Bo-Hye; Lee, Jehee

    2015-05-01

    Antioxidative defense renders a significant protection against environmental stress in organisms and maintains the correct redox balance in cells, thereby supporting proper immune function. Catalase is an indispensable antioxidant in organisms that detoxifies hydrogen peroxides produced in cellular environments. In this study, we sought to molecularly characterize a homolog of catalase (RfCat), identified from black rockfish (Sebastes schlegelii). RfCat consists of a 1581 bp coding region for a protein of 527 amino acids, with a predicted molecular weight of 60 kD. The protein sequence of RfCat harbored similar domain architecture to known catalases, containing a proximal active site signature and proximal heme ligand signature, and further sharing prominent homology with its teleostan counterparts. As affirmed by multiple sequence alignments, most of the functionally important residues were well conserved in RfCat. Furthermore, our phylogenetic analysis indicates its common vertebrate ancestral origin and a close evolutionary relationship with teleostan catalases. Recombinantly expressed RfCat demonstrated prominent peroxidase activity that varied with different substrate and protein concentrations, and protected against DNA damage. RfCat mRNA was ubiquitously expressed among different tissues examined, as detected by qPCR. In addition, RfCat mRNA expression was modulated in response to pathogenic stress elicited by Streptococcus iniae and poly I:C in blood and spleen tissues. Collectively, our findings indicate that RfCat may play an indispensable role in host response to oxidative stress and maintain a correct redox balance after a pathogen invasion.

  17. 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.

  18. 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.

  19. Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat

    Directory of Open Access Journals (Sweden)

    L.G.A. Chuffa

    2011-03-01

    Full Text Available Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g, were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight-1·day-1 both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05. Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2% and estrous cycle remained extensive (26.7%, arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9% and total antioxidant substances were enhanced within the ovaries (23.9%. Additionally, melatonin increased superoxide dismutase (21.3%, catalase (23.6% and glutathione-reductase (14.8% activities and the reducing power (10.2% GSH/GSSG ratio. We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.

  20. Effect of treadmill exercise and Ferula gummosa on myocardial HSP72, vascular function, and antioxidant defenses in spontaneously hypertensive rats.

    Science.gov (United States)

    Gholitabar, Samira; Roshan, Valiollah Dabidi

    2013-01-01

    This study evaluates the effect of treadmill exercise and Ferula gummosa (FG) on heat shock protein (HSP72), biomarkers related to vascular function, and oxidant/antioxidant system in the heart tissue of spontaneously hypertensive rats treated with N(ω)-nitro-L-arginine-methyl ester (L-NAME). Fifty adult male Wistar rats are randomly classified into five groups: treadmill exercise, FG, combination of treadmill exercise + FG, L-NAME, and saline. Treadmill exercise was performed between 25 and 64 minutes at the speed of 15-22 m per minute for 8 weeks and five sessions a week. The FG will be fed through gavage with 90 mg/kg dosage. Hypertension was induced by l-NAME (10 mg/kg) for 8 weeks and six sessions a week. Administration of L-NAME for 8 weeks caused significant increase in HSP72, angiotensin-converting enzyme (ACE), and protein carbonyl (PC), and significant decrease in glutathione peroxidase (GPx) and nitric oxide (NO) level, when compared with the saline group. In contrast, both treadmill exercise and/or FG protocols, in particular, the combined protocol, led to the improvement in HSP72 and balance in oxidant/antioxidant process and inhibited vascular dysfunction, when compared with the L-NAME group. Moreover, no significant differences were detected in the HSP72 level between rats in the treadmill exercise and FG groups. These results provide a rationale for an inhibitory role and a cardioprotective effect of lifestyle related to the health in the attenuation of hypertension-induced cardiotoxicity.

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

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    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.

  2. Nuclear-localized AtHSPR links abscisic acid-dependent salt tolerance and antioxidant defense in Arabidopsis.

    Science.gov (United States)

    Yang, Tao; Zhang, Liang; Hao, Hongyan; Zhang, Peng; Zhu, Haowei; Cheng, Wei; Wang, Yongli; Wang, Xinyu; Wang, Chongying

    2015-12-01

    Salt stress from soil or irrigation water limits plant growth. A T-DNA insertion mutant in C24, named athspr (Arabidopsis thaliana heat shock protein-related), showed several phenotypes, including reduced organ size and enhanced sensitivity to environmental cues. The athspr mutant is severely impaired under salinity levels at which wild-type (WT) plants grow normally. AtHSPR encodes a nuclear-localized protein with ATPase activity, and its expression was enhanced by high salinity and abscisic acid (ABA). Overexpression (OE) of AtHSPR significantly enhanced tolerance to salt stress by increasing the activities of the antioxidant system and by maintaining K(+) /Na(+) homeostasis. Quantitative RT-PCR analyses showed that OE of AtHSPR increased the expression of ABA/stress-responsive, salt overly sensitive (SOS)-related and antioxidant-related genes. In addition, ABA content was reduced in athspr plants with or without salt stress, and exogenous ABA restored WT-like salt tolerance to athspr plants. athspr exhibited increased leaf stomatal density and stomatal index, slower ABA-induced stomatal closure and reduced drought tolerance relative to the WT. AtHSPR OE enhanced drought tolerance by reducing leaf water loss and stomatal aperture. Transcript profiling in athspr showed a differential salt-stress response for genes involved in accumulation of reactive oxygen species (ROS), ABA signaling, cell death, stress response and photosynthesis. Taken together, our results suggested that AtHSPR is involved in salt tolerance in Arabidopsis through modulation of ROS levels, ABA-dependent stomatal closure, photosynthesis and K(+) /Na(+) homeostasis.

  3. The interaction between nonalcoholic steatosis, anthropometric indicators and disturbance of lipid peroxidation and antioxidant defense in patients with signs of obesity

    Directory of Open Access Journals (Sweden)

    Filippova A.Yu.

    2016-12-01

    Full Text Available Aim - to study charac­teristics of indicators of lipid peroxidation (LPO and antioxidant system (AOS, depending on the body mass index (BMI in patients with non-alcoholic steatosis (NASP in combination with obesity (OB and pathology of the biliary tract (BT. The study involved 100 patients with NASP in combination with OB and BT pathology, who at the time of sonographic and morphological study of liver biopsy presented signs of hepatic steatosis. Among the patients there were 19 men and 81 women. The average age of patients - (53,67 ± 1,11 years. The control group consisted of 20 practically healthy persons (PHP. BMI is determined by the formula Quetelet. Depending on the degree of BMI increase all patients with NASH and obe­sity were divided into three groups: 1 group – with BМI 25-29,9 kg/m2– ex­cessive body mass; 2 group – with BMI 30-34,9 kg/m2– obesity of I degree; 3 group – with BMI 35–39,9 kg/m2– obesity of ІІ degree. Status of LPO system was assessed by the concentration of malondialdehyde in plasma and red blood cells and the content of lipid peroxidation intermediates in the two phases of the lipid extract – isolated double bonds, diene conjugates, oksidien conjugates and the final LPO products – schiff bases. Factors of antioxidant defense activity were assessed by ceruloplasmin (CP, superoxide dismutase (SOD and catalase in erythrocyte hemolysate. All LPO indicators have been activated in the two phases of lipid extract (from p<0,05 to p<0,001 when compared with a group of PHP and p<0,05 as compared to other groups of patients and depended on increasing BMI. Indicators of AOS – SOD and catalase in all NASP groups practically did not differ from PHP parameters and did not depend on the increase of BMI. From the CP side a compensatory increase in its activity in response to the intensification of LPO was revealed. In NASP patients in combination with OB and comorbid disorders of BT the course of the disease

  4. Ulva lactuca polysaccharides prevent Wistar rat breast carcinogenesis through the augmentation of apoptosis, enhancement of antioxidant defense system, and suppression of inflammation

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    Abd-Ellatef GF

    2017-02-01

    cytokines tumor necrosis factor-α and nitric oxide were significantly ameliorated in DMBA-administered rats treated with ulvan polysaccharides as compared to DMBA-administered control. Conclusion: In conclusion, ulvan polysaccharides at the level of initiation and promotion might have potential chemopreventive effects against breast carcinogenesis. These preventive effects may be mediated through the augmentation of apoptosis, suppression of oxidative stress and inflammation, and enhancement of antioxidant defense system. Keywords: breast carcinogenesis, cancer initiation, cancer promotion, Ulva lactuca polysaccharides, DMBA, oxidative stress, apoptosis

  5. Metabolism and antioxidant defense in the larval chironomid Tanytarsus minutipalpus: adjustments to diel variations in the extreme conditions of Lake Magadi

    Science.gov (United States)

    Wood, Chris M.; Bergman, Harold L.; Johannsson, Ora E.; Laurent, Pierre; Chevalier, Claudine; Kisipan, Mosiany L.; Kavembe, Geraldine D.; Papah, Michael B.; Brix, Kevin V.; De Boeck, Gudrun; Maina, John N.; Ojoo, Rodi O.; Bianchini, Adalto

    2017-01-01

    ABSTRACT Insect larvae are reported to be a major component of the simple but highly productive trophic web found in Lake Magadi (Kenya, Africa), which is considered to be one of the most extreme aquatic environments on Earth. Previous studies show that fish must display biochemical and physiological adjustments to thrive under the extreme conditions of the lake. However, information for invertebrates is lacking. In the present study, the occurrence of the larval chironomid Tanytarsus minutipalpus is reported in Lake Magadi for the first time. Additionally, changes in larval metabolism and antioxidant defense correlated with diel variations in the extremely hostile environmental conditions of the lake are described. Wide variations in water temperature (20.2-29.3°C) and dissolved oxygen content (3.2-18.6 mg O2 l−1) were observed at different times of day, without significant change in water pH (10.0±0.03). Temperature and dissolved oxygen were higher at 13:00 h (29.3±0.4°C and 18.6±1.0 mg O2 l−1) and 19:00 h (29.3±0.8°C and 16.2±1.6 mg O2 l−1) and lower at 01:00 h (21.1±0.1°C and 10.7±0.03 mg O2 l−1) and 07:00 h (20.2±0.4°C and 3.2±0.7 mg O2 l−1). Significant and parallel increases in parameters related to metabolism (cholinesterase, glucose, cholesterol, urea, creatinine and hemoglobin) and the antioxidant system (SOD, GPx, GR, GSH and GSSG) were observed in larvae collected at 13:00 h. In contrast, no significant changes were observed in pro-oxidants (ROS and NO), TOSC and oxidative damage parameters (LPO and DNA damage). Therefore, the observed increases in temperature and dissolved O2 content in Lake Magadi were associated with changes in the antioxidant system of T. minutipalpus larvae. Adjustments performed by the chironomid larvae were efficient in maintaining body homeostasis, as well as protecting biomolecules against oxidative damage, so that oxidative stress did not occur. GSH-GSSG and GPx-GR systems appeared to

  6. Metabolism and antioxidant defense in the larval chironomid Tanytarsus minutipalpus: adjustments to diel variations in the extreme conditions of Lake Magadi

    Directory of Open Access Journals (Sweden)

    Lucas F. Bianchini

    2017-01-01

    Full Text Available Insect larvae are reported to be a major component of the simple but highly productive trophic web found in Lake Magadi (Kenya, Africa, which is considered to be one of the most extreme aquatic environments on Earth. Previous studies show that fish must display biochemical and physiological adjustments to thrive under the extreme conditions of the lake. However, information for invertebrates is lacking. In the present study, the occurrence of the larval chironomid Tanytarsus minutipalpus is reported in Lake Magadi for the first time. Additionally, changes in larval metabolism and antioxidant defense correlated with diel variations in the extremely hostile environmental conditions of the lake are described. Wide variations in water temperature (20.2-29.3°C and dissolved oxygen content (3.2-18.6 mg O2 l−1 were observed at different times of day, without significant change in water pH (10.0±0.03. Temperature and dissolved oxygen were higher at 13:00 h (29.3±0.4°C and 18.6±1.0 mg O2 l−1 and 19:00 h (29.3±0.8°C and 16.2±1.6 mg O2 l−1 and lower at 01:00 h (21.1±0.1°C and 10.7±0.03 mg O2 l−1 and 07:00 h (20.2±0.4°C and 3.2±0.7 mg O2 l−1. Significant and parallel increases in parameters related to metabolism (cholinesterase, glucose, cholesterol, urea, creatinine and hemoglobin and the antioxidant system (SOD, GPx, GR, GSH and GSSG were observed in larvae collected at 13:00 h. In contrast, no significant changes were observed in pro-oxidants (ROS and NO, TOSC and oxidative damage parameters (LPO and DNA damage. Therefore, the observed increases in temperature and dissolved O2 content in Lake Magadi were associated with changes in the antioxidant system of T. minutipalpus larvae. Adjustments performed by the chironomid larvae were efficient in maintaining body homeostasis, as well as protecting biomolecules against oxidative damage, so that oxidative stress did not occur. GSH-GSSG and GPx-GR systems appeared to

  7. Chromosome-level genome map provides insights into diverse defense mechanisms in the medicinal fungus Ganoderma sinense.

    Science.gov (United States)

    Zhu, Yingjie; Xu, Jiang; Sun, Chao; Zhou, Shiguo; Xu, Haibin; Nelson, David R; Qian, Jun; Song, Jingyuan; Luo, Hongmei; Xiang, Li; Li, Ying; Xu, Zhichao; Ji, Aijia; Wang, Lizhi; Lu, Shanfa; Hayward, Alice; Sun, Wei; Li, Xiwen; Schwartz, David C; Wang, Yitao; Chen, Shilin

    2015-06-05

    Fungi have evolved powerful genomic and chemical defense systems to protect themselves against genetic destabilization and other organisms. However, the precise molecular basis involved in fungal defense remain largely unknown in Basidiomycetes. Here the complete genome sequence, as well as DNA methylation patterns and small RNA transcriptomes, was analyzed to provide a holistic overview of secondary metabolism and defense processes in the model medicinal fungus, Ganoderma sinense. We reported the 48.96 Mb genome sequence of G. sinense, consisting of 12 chromosomes and encoding 15,688 genes. More than thirty gene clusters involved in the biosynthesis of secondary metabolites, as well as a large array of genes responsible for their transport and regulation were highlighted. In addition, components of genome defense mechanisms, namely repeat-induced point mutation (RIP), DNA methylation and small RNA-mediated gene silencing, were revealed in G. sinense. Systematic bioinformatic investigation of the genome and methylome suggested that RIP and DNA methylation combinatorially maintain G. sinense genome stability by inactivating invasive genetic material and transposable elements. The elucidation of the G. sinense genome and epigenome provides an unparalleled opportunity to advance our understanding of secondary metabolism and fungal defense mechanisms.

  8. Effects of experimentally induced maternal hypothyroidism and hyperthyroidism on the development of rat offspring: II-the developmental pattern of neurons in relation to oxidative stress and antioxidant defense system.

    Science.gov (United States)

    Ahmed, O M; Ahmed, R G; El-Gareib, A W; El-Bakry, A M; Abd El-Tawab, S M

    2012-10-01

    Excessive concentrations of free radicals in the developing brain may lead to neurons maldevelopment and neurons damage and death. Thyroid hormones (THs) states play an important role in affecting the modulation of oxidative stress and antioxidant defense system. Thus, the objective of this study was to clarify the effect of hypothyroidism and hyperthyroidism in rat dams on the neurons development of different brain regions of their offspring at several postnatal weeks in relation to changes in the oxidative stress and antioxidant defense system. The adult female rats were administered methimazole (MMI) in drinking water (0.02% w/v) from gestation day 1 to lactation day 21 to induce hypothyroidism and exogenous thyroxine (T4) in drinking water (0.002% w/v) beside intragastric incubation of 50--200 T4 μg/kg body weight (b. wt.) to induce hyperthyroidism. In normal female rats, the sera total thyroxine (TT4) and total triiodothyronine (TT3) levels were detectably increased at day 10 post-partum than those at day 10 of pregnancy. Free thyroxine (FT4), free triiodothyronine (FT3), thyrotropin (TSH) and growth hormone (GH) concentrations in normal offspring were elevated at first, second and third postnatal weeks in an age-dependent manner. In hypothyroid group, a marked depression was observed in sera of dam TT3 and TT4 as well as offspring FT3, FT4 and GH, while there was a significant increase in TSH level with the age progress. The reverse pattern to latter state was recorded in hyperthyroid group. Concomitantly, in control offspring, the rate of neuron development in both cerebellar and cerebral cortex was increased in its density and complexity with age progress. This development may depend, largely, on THs state. Both maternal hypothyroidism and hyperthyroidism caused severe growth retardation in neurons of these regions of their offspring from the first to third weeks. Additionally, in normal offspring, seven antioxidant enzymes, four non-enzymatic antioxidants

  9. Overexpression of the Maize psbA Gene Enhances Drought Tolerance Through Regulating Antioxidant System, Photosynthetic Capability, and Stress Defense Gene Expression in Tobacco.

    Science.gov (United States)

    Huo, Yongjin; Wang, Meiping; Wei, Yangyang; Xia, Zongliang

    2015-01-01

    The psbA (encoding D1 protein) plays an important role in protecting photosystem II (PSII) from oxidative damage in higher plants. In our previous study, the role of the psbA from maize (Zea mays. L) in response to SO2 stress was characterized. To date, information about the involvement of the psbA gene in drought response is scarce. Here we found that overexpression (OE) of ZmpsbA showed increased D1 protein abundance and enhanced drought stress tolerance in tobacco. The drought-tolerant phenotypes of the OE lines were accompanied by increases of key antioxidant enzymes SOD, CAT, and POD activities, but decreases of hydrogen peroxide, malondialdehyde, and ion leakage. Further investigation showed that the OE plants had much less reductions than the wild-type in the net photosynthesis rate (Pn), stomatal conductance (Gs), and the maximal photochemical efficiency of PSII (Fv/Fm) during drought stress; indicating that OE of ZmpsbA may alleviate photosynthesis inhibition during drought. qRT-PCR analysis revealed that there was significantly increased expression of NtLEA5, NtERD10C, NtAREB, and NtCDPK2 in ZmpsbA-OE lines. Together, our results indicate that ZmpsbA improves drought tolerance in tobacco possibly by alleviating photosynthesis reduction, reducing reactive oxygen species accumulation and membrane damage, and modulating stress defense gene expression. ZmpsbA could be exploited for engineering drought-tolerant plants in molecular breeding of crops.

  10. Overexpression of the Maize psbA Gene Enhances Drought Tolerance Through Regulating Antioxidant System, Photosynthetic Capability, and Stress Defense Gene Expression in Tobacco

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    Yongjin eHuo

    2016-01-01

    Full Text Available The psbA (encoding D1 protein plays an important role in protecting photosystem II (PSII from oxidative damage in higher plants. In our previous study, the role of the psbA from maize (Zea mays. L in response to SO2 stress was characterized. To date, information about the involvement of the psbA gene in drought response is scarce. Here we found that overexpression (OE of ZmpsbA showed increased D1 protein abundance and enhanced drought stress tolerance in tobacco. The drought-tolerant phenotypes of the OE lines were accompanied by increases of key antioxidant enzymes SOD, CAT, and POD activities, but decreases of hydrogen peroxide, malondialdehyde and ion leakage. Further investigation showed that the OE plants had much less reductions than the wild-type in the net photosynthesis rate (Pn, stomatal conductance (Gs, and the maximal photochemical efficiency of PSII (Fv/Fm during drought stress; indicating that overexpression of ZmpsbA may alleviate photosynthesis inhibition during drought. qRT-PCR analysis revealed that there was significantly increased expression of NtLEA5, NtERD10C, NtAREB, and NtCDPK2 in ZmpsbA-OE lines. Together, our results indicate that ZmpsbA improves drought tolerance in tobacco possibly by alleviating photosynthesis reduction, reducing ROS accumulation and membrane damage, and modulating stress defense gene expression. ZmpsbA could be exploited for engineering drought-tolerant plants in molecular breeding of crops.

  11. 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

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

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    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.

  13. Antioxidant and Vasodilator Activity of Ugni molinae Turcz. (Murtilla and Its Modulatory Mechanism in Hypotensive Response

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    Ignacio Jofré

    2016-01-01

    Full Text Available Hypertension is a systemic condition with high morbidity and mortality rates worldwide, which poses an increased risk for cardiovascular diseases. In this study, we demonstrated the antioxidant and vasodilator activity of Ugni molinae Turcz. (Murtilla fruit, a berry native to Chile and proposed models to explain its modulatory mechanism in hypotensive response. Murtilla fruits were cultivated in a germplasm bank and submitted to chemical and biological analyses. The phenolic compounds gallic acid, Catechin, Quercetin-3-β-D-glucoside, Myricetin, Quercetin, and Kaempferol were identified. Murtilla extract did not generate toxic effects on human endothelial cells and had significant antioxidant activity against ROS production, lipid peroxidation, and superoxide anion production. Furthermore, it showed dose-dependent vasodilator activity in aortic rings in the presence of endothelium, whose hypotensive mechanism is partially mediated by nitric oxide synthase/guanylate cyclase and large-conductance calcium-dependent potassium channels. Murtilla fruits might potentially have beneficial effects on the management of cardiovascular diseases.

  14. 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.

  15. Sulfur mediated reduction of arsenic toxicity involves efficient thiol metabolism and the antioxidant defense system in rice.

    Science.gov (United States)

    Dixit, Garima; Singh, Amit Pal; Kumar, Amit; Singh, Pradyumna Kumar; Kumar, Smita; Dwivedi, Sanjay; Trivedi, Prabodh Kumar; Pandey, Vivek; Norton, Gareth John; Dhankher, Om Parkash; Tripathi, Rudra Deo

    2015-11-15

    Arsenic (As) contamination is a global issue, with South Asia and South East Asia being worst affected. Rice is major crop in these regions and can potentially pose serious health risks due to its known As accumulation potential. Sulfur (S) is an essential macronutrient and a vital element to combat As toxicity. The aim of this study was to investigate the role of S with regards to As toxicity in rice under different S regimes. To achieve this aim, plants were stressed with AsIII and AsV under three different S conditions (low sulfur (0.5mM), normal sulfur (3.5mM) and high sulfur (5.0mM)). High S treatment resulted in increased root As accumulation, likely due to As complexation through enhanced synthesis of thiolic ligands, such as non-protein thiols and phytochelatins, which restricted As translocation to the shoots. Enzymes of S assimilatory pathways and downstream thiolic metabolites were up-regulated with increased S supplementation; however, to maintain optimum concentrations of S, transcript levels of sulfate transporters were down-regulated at high S concentration. Oxidative stress generated due to As was counterbalanced in the high S treatment by reducing hydrogen peroxide concentration and enhancing antioxidant enzyme activities. The high S concentration resulted in reduced transcript levels of Lsi2 (a known transporter of As). This reduction in Lsi2 expression level is a probable reason for low shoot As accumulation, which has potential implications in reducing the risk of As in the food chain.

  16. Impact of osmotic stress on seedling growth observations, membrane characteristics and antioxidant defense system of different wheat genotypes

    Directory of Open Access Journals (Sweden)

    Bardees M. Mickky

    2017-03-01

    Full Text Available The objective of the present study was to find out a straightforward technique for screening the tolerance of ten wheat genotypes to two levels of osmotic stress at early seedling stage. Data revealed that polyethylene glycol-induced drought had general negative effect on seedling morphological characters indicated by plumule and radicle length, number of adventitious roots as well as seedling biomass and water content. Water deficit could also suppress membrane integrity by stimulating lipid peroxidation with marked increase in membrane leakage and subsequent decrease in its stability index. For all the addressed germination parameters and seedling membrane features, the impact of severe drought was more pronounced than that of moderate drought. Simultaneously, moderate stress could activate peroxidase, polyphenol oxidase and ascorbic peroxidase of the studied genotypes; but these enzymes were inhibited by severe stress. The activity of catalase, superoxide dismutase and glutathione reductase was conversely retarded by drought whether at moderate or severe level. More interestingly, a novel function “Stress Impact Index; SII” was introduced to rank the estimated morpho-physiological traits (SIItrait as well as the considered genotypes (SIIgenotype according to their sensitivity to stress. Values of SIItrait implied that germination parameters were generally affected by drought more intensively than membrane characteristics and finally came the antioxidant enzymes with the least degree of suppression when applying stress. Based on the magnitudes of SIIgenotype, Sids 13 seemed to be the most drought-tolerant wheat cultivar while Shandawel 1 could be the most sensitive one at their juvenile growth stage.

  17. 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.

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

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    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.

  19. 植物抗病毒分子机制%Molecular Mechanism of Plant Antiviral Defense

    Institute of Scientific and Technical Information of China (English)

    钱礼超; 刘玉乐

    2014-01-01

    在与植物病毒的长期斗争中,植物进化出多种抗病毒机制,其中RNA沉默和R基因介导的病毒抗性是最受人们关注的两种机制.一方面,RNA沉默是植物抵抗病毒侵染的重要手段.植物在病毒侵染过程中可形成病毒来源的双链RNA,经过DCL蛋白的切割、加工形成sRNA,与AGO蛋白结合形成RISC指导病毒RNA的沉默,用于清除病毒.相应地,病毒在与植物的竞争中进化出RNA沉默抑制子,抑制宿主RNA沉默系统以逃避宿主RNA沉默抗病毒反应,增强致病能力.另一方面,植物也进化出R基因介导植物对包括病毒在内的多类病原的抗性.R蛋白直接或间接识别病毒因子,通过一系列的信号转导途径激活植物防御反应,限制病毒的进一步侵染.对植物抗病毒的研究有助于人们对植物抗病分子基础的理解,有重要的科学意义和潜在应用价值.本文综述了植物抗病毒分子机制的重要进展.%During a long coevolutionary arms race between plants and viruses,plants have evolved various antiviral defense mechanisms.Among them,RNA silencing and R gene-mediated virus resistance attract more attention.On the one hand,RNA silencing plays an important role in plant resistance against viruses.During virus infection,virus-derived double stranded RNAs can be formed and processed into small RNAs to target viral RNAs for destruction.Accordingly,viruses have evolved to produce RNA silencing suppressors to overcome host RNA silencing and enhance virus infection.On the other hand,plants have also evolved R gene-mediated resistance to various pathogens including viruses.Research on plant antiviral defense will help understanding of the molecular basis of plant disease resistance,and will have important scientific significance and potential application value.This manuscript reviews the important advances in molecular plant antiviral defense mechanisms.

  20. 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.

  1. 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.

  2. Antioxidants from black and green tea: from dietary modulation of oxidative stress to pharmacological mechanisms.

    Science.gov (United States)

    Peluso, Ilaria; Serafini, Mauro

    2016-10-16

    The consumption of tea (Camellia sinensis) has been correlated with a low incidence of chronic pathologies, such as cardiovascular disease and cancer, in which oxidative stress plays a critical role. Tea catechins and theaflavins are, respectively, the bioactive phytochemicals responsible for the antioxidant activity of green tea (GT) and black tea (BT). In addition to their redox properties, tea catechins and theaflavins could have also pharmacological activities, such as the ability to lower glucose, lipid and uric acid (UA) levels. These activities are mediated by pharmacological mechanisms such as enzymatic inhibition and interaction with transporters. Epigallocatechin gallate is the most active compound at inhibiting the enzymes involved in cholesterol and UA metabolism (hydroxy-3-methyl-glutaryl-CoA reductase and xanthine oxidase respectively) and affecting glucose transporters. The structural features of catechins that significantly contribute to their pharmacological effect are the presence/absence of the galloyl moiety and the number and positions of the hydroxyl groups on the rings. Although the inhibitory effects on α-glucosidase, maltase, amylase and lipase, multidrug resistance 1, organic anion transporters and proton-coupled folate transport occur at higher concentrations than those apparent in the circulation, these effects could be relevant in the gut. In conclusion, despite the urgent need for further research in humans, the regular consumption of moderate quantities of GT and BT can effectively modulate their antioxidant capacity, mainly in people subjected to oxidative stress, and could improve the metabolism of glucose, lipid and UA.

  3. 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.

  4. UVR defense mechanisms in eurytopic and invasive Gracilaria vermiculophylla (Gracilariales, Rhodophyta).

    Science.gov (United States)

    Roleda, Michael Y; Nyberg, Cecilia D; Wulff, Angela

    2012-10-01

    The invasive success of Gracilaria vermiculophylla has been attributed to its wide tolerance range to different abiotic factors, but its response to ultraviolet radiation (UVR) is yet to be investigated. In the laboratory, carpospores and vegetative thalli of an Atlantic population were exposed to different radiation treatments consisting of high PAR (photosynthetically active radiation) only (P), PAR+UV-A (PA) and PAR+UV-A+UV-B (PAB). Photosynthesis of carpospores was photoinhibited under different radiation treatments but photosystem II (PSII) function was restored after 12 h under dim white light. Growth of vegetative thalli was significantly higher under radiation supplemented with UVR. Decrease in chlorophyll a (Chl a) under daily continuous 16-h exposure to 300 µmol photons m(-2) s(-1) of PAR suggests preventive accumulation of excited chlorophyll molecules within the antennae to minimize the generation of dangerous reactive oxygen species. Moreover, an increase in total carotenoids and xanthophyll cycle pigments (i.e. violaxanthin, antheraxanthin and zeaxanthin) further suggests effective photoprotection under UVR. The presence of the ketocarotenoid β-cryptoxanthin also indicates protection against UVR and oxidative stress. The initial concentration of total mycosporine-like amino acids (MAAs) in freshly-released spores increased approximately four times after 8-h laboratory radiation treatments. On the other hand, initial specific MAAs in vegetative thalli changed in composition after 7-day exposure to laboratory radiation conditions without affecting the total concentration. The above responses suggest that G. vermiculophylla have multiple UVR defense mechanisms to cope with the dynamic variation in light quantity and quality encountered in its habitat. Beside being eurytopic, the UVR photoprotective mechanisms likely contribute to the current invasive success of the species in shallow lagoons and estuaries exposed to high solar radiation.

  5. Anti-inflammatory and antioxidant properties of Piper species: a perspective from screening to molecular mechanisms.

    Science.gov (United States)

    Kumar, Sarvesh; Malhotra, Shashwat; Prasad, Ashok K; Van der Eycken, Erik V; Bracke, Marc E; Stetler-Stevenson, William G; Parmar, Virinder S; Ghosh, Balaram

    2015-01-01

    Identifying novel therapeutic agents from natural sources and their possible intervention studies has been one of the major areas in biomedical research in recent years. Piper species are highly important - commercially, economically and medicinally. Our groups have been working for more than two decades on the identification and characterization of novel therapeutic lead molecules from Piper species. We have extensively studied the biological activities of various extracts of Piper longum and Piper galeatum, and identified and characterized novel molecules from these species. Using synthetic chemistry, various functional groups of the lead molecules were modified and structure activity relationship (SAR) studies identified synthetic molecules with better efficacy and lower IC50 values. Moreover, the mechanisms of actions of some of these molecules were studied at the molecular level. The objective of this review is to summarize experimental data published from our laboratories and others on antioxidant and anti-inflammatory potentials of Piper species and their chemical constituents.

  6. 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

    2016-01-01

    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 < .05) elevated. The cerebellar and cerebral catalase (CAT), superoxide dismutase and glutathione-S-transferase (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.

  7. 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

  8. Plant structural complexity and mechanical defenses mediate predator-prey interactions in an odonate-bird system.

    Science.gov (United States)

    Grof-Tisza, Patrick; LoPresti, Eric; Heath, Sacha K; Karban, Richard

    2017-03-01

    Habitat-forming species provide refuges for a variety of associating species; these refuges may mediate interactions between species differently depending on the functional traits of the habitat-forming species. We investigated refuge provisioning by plants with different functional traits for dragonfly and damselfly (Odonata: Anisoptera and Zygoptera) nymphs emerging from water bodies to molt into their adult stage. During this period, nymphs experience high levels of predation by birds. On the shores of a small pond, plants with mechanical defenses (e.g., thorns and prickles) and high structural complexity had higher abundances of odonate exuviae than nearby plants which lacked mechanical defenses and exhibited low structural complexity. To disentangle the relative effects of these two potentially important functional traits on nymph emergence-site preference and survival, we conducted two fully crossed factorial field experiments using artificial plants. Nymphs showed a strong preference for artificial plants with high structural complexity and to a lesser extent, mechanical defenses. Both functional traits increased nymph survival but through different mechanisms. We suggest that future investigations attempt to experimentally separate the elements contributing to structural complexity to elucidate the mechanistic underpinnings of refuge provisioning.

  9. Host Defense Mechanisms against Bark Beetle Attack Differ between Ponderosa and Lodgepole Pines

    Directory of Open Access Journals (Sweden)

    Daniel R. West

    2016-10-01

    Full Text Available Conifer defenses against bark beetle attack include, but are not limited to, quantitative and qualitative defenses produced prior to attack. Our objective was to assess host defenses of lodgepole pine and ponderosa pine from ecotone stands. These stands provide a transition of host species for mountain pine beetle (Dendroctonus ponderosae; MPB. We asked two questions: (1 do the preformed quantitative host defenses (amount of resin and (2 the preformed qualitative host defenses (monoterpene constituents differ between lodgepole and ponderosa pines. We collected oleoresins at three locations in the Southern Rocky Mountains from 56 pairs of the pine species of similar size and growing conditions. The amount of preformed-ponderosa pine oleoresins exuded in 24 h (mg was almost four times that of lodgepole pine. Total qualitative preformed monoterpenes did not differ between the two hosts, though we found differences in all but three monoterpenes. No differences were detected in α-pinene, γ-terpinene, and bornyl acetate. We found greater concentrations of limonene, β-phellandrene, and cymene in lodgepole pines, whereas β-pinene, 3-carene, myrcene, and terpinolene were greater in ponderosa pine. Although we found differences both in quantitative and qualitative preformed oleoresin defenses, the ecological relevance of these differences to bark beetle susceptibility have not been fully tested.

  10. 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.

  11. 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.

  12. Gender differences in defense mechanisms, ways of coping with stress and sense of identity in adolescent suicide attempts.

    Science.gov (United States)

    Foto-Özdemir, Dilşad; Akdemir, Devrim; Çuhadaroğlu-Çetin, Füsun

    2016-01-01

    The main aim of this study was to investigate the gender differences in defense mechanisms, ways of coping with stress and identity formation in relation to adolescent suicidal behavior. This study involved 64 adolescents between 12-17 years of age, who were admitted to the emergency service with a suicide attempt. They were evaluated with a semi-structured clinical interview (K-SADS), Ways of Coping Inventory (WCI), Defense Mechanisms Inventory (DMI) and Sense of Identity Assessment Form (SIAF). 60.9% (n = 39) of the adolescents were female, and 39.1% (n=25) were male. There were no statistically significant differences between the girls and the boys with respect to the clinical characteristics of the suicide attempt and the rate of psychiatric disorders. Of the 64 adolescents with suicide attempt, 47 (73.4%) had at least one, and 26 (40.6%) had more than one psychiatric disorder according to K-SADS. Disruptive behavior disorders were more frequent in males, whereas depression was more frequent in girls. The data indicated the importance of identity confusion, major depression and ADHD in adolescents with suicide attempt in both genders. 43.6% (n=17) of the girls and 36% (n=9) of the boys obtained scores higher than the cut-off point of SIAF indicating identity confusion. Professional help seeking and NSSI behaviors before the suicide attempt were more common in adolescents with identity confusion. While there were differences between genders with respect to the defense mechanisms used, no significant difference was found in terms of ways of coping. Evaluation of DMI scores revealed that the turning against object subscale score was significantly higher in boys compared to girls. While evaluating the adolescents at risk, their defense mechanisms, way of coping and sense of identity, as well as their psychiatric diagnosis should be assessed in detail in order to identify the suicidal thoughts and prevent possible suicide attempts.

  13. 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.

  14. 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., Sb. With a 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.

  15. Strategy and Mechanisms for Encouraging Reuse in the Acquisition of Strategic Defense Initiative Software.

    Science.gov (United States)

    1990-06-01

    that are narrower in scope than those covered in Reports. IDA Papers are reviewed to ensure that they meet the high standards expected of refereed ...Inc. 133 Defense Hwy Suite 212 Annapolis, MD 21401 0 301-261-8373 SDIO Technical Information Center 1 DRC 1755 Jeff Davis Highway Suite 802 Crystal

  16. 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...

  17. SWATH label-free proteomics analyses revealed the roles of oxidative stress and antioxidant defensing system in sclerotia formation of Polyporus umbellatus

    Science.gov (United States)

    Li, Bing; Tian, Xiaofang; Wang, Chunlan; Zeng, Xu; Xing, Yongmei; Ling, Hong; Yin, Wanqiang; Tian, Lixia; Meng, Zhixia; Zhang, Jihui; Guo, Shunxing

    2017-01-01

    Understanding the initiation and maturing mechanisms is important for rational manipulating sclerotia differentiation and growth from hypha of Polyporus umbellatus. Proteomes in P. umbellatus sclerotia and hyphae at initial, developmental and mature phases were studied. 1391 proteins were identified by nano-liquid chromatograph-mass spectrometry (LC-MS) in Data Dependant Acquisition mode, and 1234 proteins were quantified successfully by Sequential Window Acquisition of all THeoretical fragment ion spectra-MS (SWATH-MS) technology. There were 347 differentially expressed proteins (DEPs) in sclerotia at initial phase compared with those in hypha, and the DEP profiles were dynamically changing with sclerotia growth. Oxidative stress (OS) in sclerotia at initial phase was indicated by the repressed proteins of respiratory chain, tricarboxylic acid cycle and the activation of glycolysis/gluconeogenesis pathways were determined based on DEPs. The impact of glycolysis/gluconeogenesis on sclerotium induction was further verified by glycerol addition assays, in which 5% glycerol significantly increased sclerotial differentiation rate and biomass. It can be speculated that OS played essential roles in triggering sclerotia differentiation from hypha of P. umbellatus, whereas antioxidant activity associated with glycolysis is critical for sclerotia growth. These findings reveal a mechanism for sclerotial differentiation in P. umbellatus, which may also be applicable for other fungi.

  18. SWATH label-free proteomics analyses revealed the roles of oxidative stress and antioxidant defensing system in sclerotia formation of Polyporus umbellatus

    Science.gov (United States)

    Li, Bing; Tian, Xiaofang; Wang, Chunlan; Zeng, Xu; Xing, Yongmei; Ling, Hong; Yin, Wanqiang; Tian, Lixia; Meng, Zhixia; Zhang, Jihui; Guo, Shunxing

    2017-01-01

    Understanding the initiation and maturing mechanisms is important for rational manipulating sclerotia differentiation and growth from hypha of Polyporus umbellatus. Proteomes in P. umbellatus sclerotia and hyphae at initial, developmental and mature phases were studied. 1391 proteins were identified by nano-liquid chromatograph-mass spectrometry (LC-MS) in Data Dependant Acquisition mode, and 1234 proteins were quantified successfully by Sequential Window Acquisition of all THeoretical fragment ion spectra-MS (SWATH-MS) technology. There were 347 differentially expressed proteins (DEPs) in sclerotia at initial phase compared with those in hypha, and the DEP profiles were dynamically changing with sclerotia growth. Oxidative stress (OS) in sclerotia at initial phase was indicated by the repressed proteins of respiratory chain, tricarboxylic acid cycle and the activation of glycolysis/gluconeogenesis pathways were determined based on DEPs. The impact of glycolysis/gluconeogenesis on sclerotium induction was further verified by glycerol addition assays, in which 5% glycerol significantly increased sclerotial differentiation rate and biomass. It can be speculated that OS played essential roles in triggering sclerotia differentiation from hypha of P. umbellatus, whereas antioxidant activity associated with glycolysis is critical for sclerotia growth. These findings reveal a mechanism for sclerotial differentiation in P. umbellatus, which may also be applicable for other fungi. PMID:28134344

  19. Acute Exercise Increases Plasma Total Antioxidant Status and Antioxidant Enzyme Activities in Untrained Men

    Directory of Open Access Journals (Sweden)

    C. Berzosa

    2011-01-01

    Full Text Available Antioxidant defences are essential for cellular redox regulation. Since free-radical production may be enhanced by physical activity, herein, we evaluated the effect of acute exercise on total antioxidant status (TAS and the plasma activities of catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase and its possible relation to oxidative stress resulting from exercise. Healthy untrained male subjects (=34 performed three cycloergometric tests, including maximal and submaximal episodes. Venous blood samples were collected before and immediately after each different exercise. TAS and enzyme activities were assessed by spectrophotometry. An increase of the antioxidant enzyme activities in plasma was detected after both maximal and submaximal exercise periods. Moreover, under our experimental conditions, exercise also led to an augmentation of TAS levels. These findings are consistent with the idea that acute exercise may play a beneficial role because of its ability to increase antioxidant defense mechanisms through a redox sensitive pathway.

  20. 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.

  1. Study of Natural and Accelerated Weathering on Mechanical Properties of Antioxidants Modified Low Density Polyethylene Films for Greenhouse

    Directory of Open Access Journals (Sweden)

    Othman Al Othman

    2014-01-01

    Full Text Available Natural and accelerated weatherings were studied to inspect the effect of antioxidants to protect low-density polyethylene (LDPE films for commercial application as greenhouse covering materials in Saudi Arabia. In this investigation, six different formulations of LDPE film with incorporation of antioxidants were prepared and compared with neat LDPE. The samples were extruded and blown into a film using twin-screw extruder and film blowing machine. The LDPE films were exposed for outdoor weathering in Riyadh during the period of 90 days (mid of June to mid of September while the accelerated tests were performed by Weather-Ometer. The film having 0.2 wt% Alkanox-240 (AN-0.2 stabilizers showed the highest tensile strength among all samples during natural and 100-hour accelerated weathering (10.9 MPa and 21.8 MPa, resp.. The best elongation at break was witnessed in 0.2% Good-rite antioxidants which were 64% in natural weathering; however, 0.5% Good-rite antioxidants showed 232% in accelerated weathering. The film having 0.5 wt% Good-rite 3114 (GR-0.5 antioxidant could withstand 70 days during natural exposure before the tensile strength values were reduced to 2/3rd of the initial. The present study suggested that the addition of antioxidants Good-rite, Anox, and Alkanox can improve the mechanical strength, film’s life, effectiveness, and stability and they are suitable to be incorporated in LDPE for commercial greenhouse films.

  2. 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.

  3. 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.

  4. 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...

  5. OLA1, an Obg-like ATPase, suppresses antioxidant response via nontranscriptional mechanisms

    OpenAIRE

    Zhang, Jiawei; Rubio, Valentina; Lieberman, Michael W.; Shi, Zheng-Zheng

    2009-01-01

    Oxidative stress has been implicated in diverse disease states and aging. To date, induction of cellular responses to combat oxidative stress has been characterized largely at the transcriptional level, with emphasis on Nrf2-mediated activation of antioxidant response elements. In this study, we demonstrate that OLA1, a novel Obg-like ATPase, functions as a negative regulator of the cellular antioxidant response independent of transcriptional processes. Knockdown of OLA1 in human cells elicit...

  6. 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.

  7. Microbial modulation of bacoside A biosynthetic pathway and systemic defense mechanism in Bacopa monnieri under Meloidogyne incognita stress

    Science.gov (United States)

    Gupta, Rupali; Singh, Akanksha; Srivastava, Madhumita; Singh, Vivek; Gupta, M. M.; Pandey, Rakesh

    2017-01-01

    Plant-associated beneficial microbes have been explored to fulfill the imperative function for plant health. However, their impact on the host secondary metabolite production and nematode disease management remains elusive. Our present work has shown that chitinolytic microbes viz., Chitiniphilus sp. MTN22 and Streptomyces sp. MTN14 singly as well as in combination modulated the biosynthetic pathway of bacoside A and systemic defense mechanism against Meloidogyne incognita in Bacopa monnieri. Interestingly, expression of bacoside biosynthetic pathway genes (3-Hydroxy-3-methylglutaryl coenzyme A reductase, mevalonate diphosphate decarboxylase, and squalene synthase) were upregulated in plants treated with the microbial combination in the presence as well as in absence of M. incognita stress. These microbes not only augmented bacoside A production (1.5 fold) but also strengthened host resistance via enhancement in chlorophyll a, defense enzymes and phenolic compounds like gallic acid, syringic acid, ferulic acid and cinnamic acid. Furthermore, elevated lignification and callose deposition in the microbial combination treated plants corroborate well with the above findings. Overall, the results provide novel insights into the underlying mechanisms of priming by beneficial microbes and underscore their capacity to trigger bacoside A production in B. monnieri under biotic stress. PMID:28157221

  8. 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.

  9. 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.

  10. Antimicrobial terpenes from oleoresin of ponderosa pine tree Pinus ponderosa: A defense mechanism against microbial invasion

    Energy Technology Data Exchange (ETDEWEB)

    Himejima, Masaki; Hobson, K.R.; Otsuka, Toshikazu; Wood, D.L.; Kubo, Isao (Univ. of California, Berkeley (United States))

    1992-10-01

    The oleoresin of the ponderosa pine, Pinus ponderosa (Pinaceae) exhibited broad antimicrobial activity. In order to identify the active compounds, the oleoresin was steam distilled to give a distillate and residue. The distillate contained mainly monoterpenes and some sesquiterpenes, while the residue consisted chiefly of four structurally related diterpene acids. An antimicrobial assay with the pure compounds indicated that the monoterpenes were active primarily against fungi, but there was also some activity against gram-positive bacteria. The diterpene acids, in contrast, only exhibited activity against gram-positive bacteria. Although not all of the identified sesquiterpenes could be tested, longifolene showed activity only against gram-positive bacteria. Therefore, it appears that the oleoresin of P. ponderosa functions as a biochemical defense against microbial invasion.

  11. Model Wheat Genotypes as Tools to Uncover Effective Defense Mechanisms Against the Hemibiotrophic Fungus Bipolaris sorokiniana.

    Science.gov (United States)

    Ibeagha, Aloysius Ebelechukwu; Hückelhoven, Ralph; Schäfer, Patrick; Singh, Devendra Pal; Kogel, Karl-Heinz

    2005-05-01

    ABSTRACT We investigated the interaction of several differentially resistant wheatwith the hemibiotrophic phytopathogenic fungus Bipolaris sorokiniana (teleomorph Cochliobolus sativus). Wheat genotypes Yangmai, M 3 (W7976), Shanghai 4, and Chirya 7 showed higher levels of resistancewith cv. Sonalika, used as a susceptible control. In amicroscopic inspection, we found that fungal penetration intoepidermal layer failed mostly through a cell wall-associated defense. In cases where the fungus successfully overcame epidermal, its spread within the mesophyll tissue (necrotrophic phase) wasin the more resistant genotypes. Epidermal cell wall-associated, spreading as well as the extent of electrolyte leakage of infected, correlated well with field resistance. We propose that cellular hostsuch as formation of cell wall appositions as well as the degreeearly mesophyll spreading of fungal hyphae are indicative of thepotential of the respective host genotype and, therefore, could befor the characterization of new spot blotch resistance traits in cereals.

  12. 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.

  13. 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.

  14. Chemical and mechanical defenses vary among maternal lines and leaf ages in Verbascum thapsus L. (Scrophulariaceae and reduce palatability to a generalist insect.

    Directory of Open Access Journals (Sweden)

    Christina Alba

    Full Text Available Intra-specific variation in host-plant quality affects herbivore foraging decisions and, in turn, herbivore foraging decisions mediate plant fitness. In particular, variation in defenses against herbivores, both among and within plants, shapes herbivore behavior. If variation in defenses is genetically based, it can respond to natural selection by herbivores. We quantified intra-specific variation in iridoid glycosides, trichome length, and leaf strength in common mullein (Verbascum thapsus L, Scrophulariaceae among maternal lines within a population and among leaves within plants, and related this variation to feeding preferences of a generalist herbivore, Trichopulsia ni Hübner. We found significant variation in all three defenses among maternal lines, with T. ni preferring plants with lower investment in chemical, but not mechanical, defense. Within plants, old leaves had lower levels of all defenses than young leaves, and were strongly preferred by T. ni. Caterpillars also preferred leaves with trichomes removed to leaves with trichomes intact. Differences among maternal lines indicate that phenotypic variation in defenses likely has a genetic basis. Furthermore, these results reveal that the feeding behaviors of T. ni map onto variation in plant defense in a predictable way. This work highlights the importance of variation in host-plant quality in driving interactions between plants and their herbivores.

  15. 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

  16. Activation of neuronal defense mechanisms in response to pathogenic factors triggering induction of amyloidosis in Alzheimer's disease.

    Science.gov (United States)

    Maltsev, Alexander V; Santockyte, Rasa; Bystryak, Simon; Galzitskaya, Oxana V

    2014-01-01

    We present a new model for etiology of Alzheimer's disease (AD) which postulates early involvement of specialized neuroprotective mechanisms in the pathology of AD. These neuroprotective mechanisms work in concert to regulate metabolic homeostasis in healthy neuronal cells, but contribute to the distinctive cytopathic phenotype of neuronal degeneration in AD. According to this model, two molecular/genetic hallmarks of AD, amyloid-β (Aβ) deposition and tau hyperphosphorylation, are associated with neuronal mechanisms for dissipating thermal energy associated with high levels of protein synthesis in highly temperature-sensitive neuronal cells. Development of effective methods of AD treatment will require a better understanding of how this neuronal defense system is activated in response to cytopathological triggers in sporadic AD. The cause and effect link between synthesis and processing of amyloid-β protein precursor (AβPP) and the AD terminal phenotype of neurofibrillary tangles and neuron loss involve the formation of Aβ peptides that accumulate as oligomers, cannot be controlled by neurons, and are toxic to the surrounding neuronal membranes. We analyze experimental and clinical studies that have investigated the correlation between phosphorylation of some transport proteins and increased synthesis of proteins in neurons. We also review the evidence related to the possibility that protein hyperphosphorylation may be a byproduct of energetic imbalances in AD cells associated with high levels of protein synthesis, and that activation of defense systems, through which energy-rich molecules are eliminated from the site of protein synthesis and are sequestered to the peripheral neuronal areas, may bring about some of the distinctive morphological features of AD.

  17. De novo Transcriptome Analysis Reveals Distinct Defense Mechanisms by Young and Mature Leaves of Hevea brasiliensis (Para Rubber Tree).

    Science.gov (United States)

    Fang, Yongjun; Mei, Hailiang; Zhou, Binhui; Xiao, Xiaohu; Yang, Meng; Huang, Yacheng; Long, Xiangyu; Hu, Songnian; Tang, Chaorong

    2016-09-13

    Along with changes in morphology in the course of maturation, leaves of Hevea brasiliensis become more resistant to leaf diseases, including the South American Leaf Blight (SALB), a devastating fungal disease of this economically important tree species. To understand the underlying mechanisms of this defense, and to identify the candidate genes involved, we sequenced the Hevea leaf transcriptome at four developmental stages (I to IV) by Illumina sequencing. A total of 62.6 million high-quality reads were generated, and assembled into 98,796 unique transcripts. We identified 3,905 differentially expressed genes implicated in leaf development, 67.8% (2,651) of which were during the transition to leaf maturation. The genes involved in cyanogenic metabolism, lignin and anthocyanin biosynthesis were noteworthy for their distinct patterns of expression between developing leaves (stages I to III) and mature leaves (stage IV), and the correlation with the change in resistance to SALB and the Oidium/Colletotrichum leaf fall. The results provide a first profile of the molecular events that relate to the dynamics of leaf morphology and defense strategies during Hevea leaf development. This dataset is beneficial to devising strategies to engineer resistance to leaf diseases as well as other in-depth studies in Hevea tree.

  18. XSS攻击机制及防御技术浅谈%Discussion on XSS attack mechanism and defense technology

    Institute of Scientific and Technical Information of China (English)

    葛强; 李俊; 胡永权

    2016-01-01

    跨站脚本攻击(XSS)是客户端Web安全的主要威胁。因跨站脚本攻击的多样性以及Web安全漏洞的隐蔽性,使得该类型的攻击很难彻底防御。介绍了跨站脚本攻击的基本概念,针对不同环境发生的跨站脚本攻击机制进行了分析,探讨了不同环境下如何防御跨站脚本攻击的具体技术。%Cross site scripting (XSS) attack is a major threat to the security of Web client. Because of the diversity of XSS attacks and Web security vulnerabilities hidden, this type of attack is very difficult to completely defense. This paper introduces the basic concept of XSS attacks, analyzes the XSS attack mechanisms of different environment, and discusses the specific technology to defense the XSS attacks of different environment.

  19. 心理防御机制与临床实践%Defense Mechanism and Clinical Practice(review)

    Institute of Scientific and Technical Information of China (English)

    梁宝勇; 崔光成

    2002-01-01

    @@ 心理防御机制是心理卫生工作者十分熟悉的一个专业术语.这个专业术语在心理学中的应用始于S.Freud.1894年在(the Neuro-Psychoses of Defense)一书中,弗洛伊德提出防御机制同某些神经症和精神病有密切联系的猜想.1936年,他的女儿安娜.弗洛伊德(Anna Freud)出版了(the Ego and the Mechanisms of Defense)一书,进一步扩展和丰富了防御机制的理论,以致防御机制已成为精神分析心理学中的一个核心的概念.时至今天,在心理卫生实践中人们仍须经常涉及它们.

  20. 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.

  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. 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. 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.

  4. Do pathogen-specific defense mechanisms contribute to wound-induced resistance in tomato?

    Science.gov (United States)

    Francia, Doriana; Demaria, Daniele; Calderini, Ornella; Ferraris, Lucia; Valentino, Danila; Arcioni, Sergio; Tamietti, Giacomo; Cardinale, Francesca

    2008-05-01

    A network of shared intermediates/components and/or common molecular outputs in biotic and abiotic stress signaling has long been known, but the possibility of effective influence between differently triggered stresses (co-protection) is less studied. Recent observations show that wounding induces transient protection in tomato (Solanum lycopersicum L.) to four pathogens with a range of lifestyles, locally and systemically. The contribution of ethylene (ET) in basal but also in wound-induced resistance to each pathogen, although dispensable, is demonstrated to be positive (Botrytis cinerea, Phytophthora capsici) or negative (Fusarium oxysporum, Pseudomonas syringae pv. tomato). Furthermore, the expression of several defense markers is influenced locally and/or systemically by wounding and ET, and might be part of that core of conserved molecular responses whereby an abiotic stress such as wounding imparts co-resistance to biotic stress. In this addendum, we speculate on some of the physiological responses to wounding that might contribute to the modulation of resistance in a more pathogen-specific manner.

  5. Molecular mechanism of antioxidant synergism of tocotrienols and carotenoids in palm oil.

    Science.gov (United States)

    Schroeder, Maria T; Becker, Eleonora Miquel; Skibsted, Leif H

    2006-05-03

    During repeated deep-fat frying of potato slices at 163 degrees C in yellow or red palm olein of comparable fatty acid profiles, the oxidative stability (peroxide value and anisidine value) of the palm oleins was similar, and in yellow palm olein, the rate of antioxidant depletion decreased in the order gamma-T3 > alpha-T3 > delta-T3 (T3, tocotrienol). In red palm olein, which had a total tocopherol/tocotrienol content of 1260 vs 940 ppm in yellow palm olein and a corresponding longer induction period in the Rancimat stability test at 120 degrees C, only depletion of gamma-T3 was significant among the phenols during frying and slower as compared to that in yellow palm olein. The carotenes in the red palm olein were depleted linearly with the number of fryings, apparently yielding an overall protection of the phenols. In antioxidant-depleted palm olein and in phospholipid liposomes with added increasing concentrations of phenols, gamma-T3 was found to be a better antioxidant than alpha-T3. alpha-T3 and alpha-T (T, tocopherol) had a similar antioxidant effect in antioxidant-depleted palm olein in the Rancimat stability test, while in the liposomes the ordering as determined by induction period for the formation of conjugated dienes was gamma-T3 > alpha-T3 > alpha-T. The addition of 100-1000 ppm beta-carotene to antioxidant-depleted palm olein or liposomes (lycopene also tested) did not provide any protection against oxidation. In the liposomes, synergistic interactions were observed between beta-carotene or lycopene and alpha-T, alpha-T3, or gamma-T3 for carotene/phenol ratios of 1:10 and 1:2 but not for 1:1. In chloroform, carotenes were regenerated by tocopherols/tocotrienols from carotene radicals generated by laser flash photolysis as shown by transient absorption spectroscopy, suggesting that carotenes rather than phenols are the primary substrate for lipid-derived radicals in red palm olein, in effect depleting carotenes prior to phenols during frying

  6. 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.

  7. Priming for JA-dependent defenses using hexanoic acid is an effective mechanism to protect Arabidopsis against B. cinerea.

    Science.gov (United States)

    Kravchuk, Zhana; Vicedo, Begonya; Flors, Víctor; Camañes, Gemma; González-Bosch, Carmen; García-Agustín, Pilar

    2011-03-01

    Soil drench treatments with hexanoic acid can effectively protect Arabidopsis plants against Botrytis cinerea through a mechanism based on a stronger and faster accumulation of JA-dependent defenses. Plants impaired in ethylene, salicylic acid, abscisic acid or glutathion pathways showed intact protection by hexanoic acid upon B. cinerea infection. Accordingly, no significant changes in the SA marker gene PR-1 in either the SA or ABA hormone balance were observed in the infected and treated plants. In contrast, the JA signaling pathway showed dramatic changes after hexanoic acid treatment, mainly when the pathogen was present. The impaired JA mutants, jin1-2 and jar1, were unable to display hexanoic acid priming against the necrotroph. In addition, hexanoic acid-treated plants infected with B. cinerea showed priming in the expression of the PDF1.2, PR-4 and VSP1 genes implicated in the JA pathways. Moreover, JA and OPDA levels were primed at early stages by hexanoic acid. Treatments also stimulated increased callose accumulation in response to the pathogen. Although callose accumulation has proved an effective IR mechanism against B. cinerea, it is apparently not essential to express hexanoic acid-induced resistance (HxAc-IR) because the mutant pmr4.1 (callose synthesis defective mutant) is protected by treatment. We recently described how hexanoic acid treatments can protect tomato plants against B. cinerea by stimulating ABA-dependent callose deposition and by priming OPDA and JA-Ile production. We clearly demonstrate here that Hx-IR is a dependent plant species, since this acid protects Arabidopsis plants against the same necrotroph by priming JA-dependent defenses without enhancing callose accumulation.

  8. Leaf Age-Dependent Photoprotective and Antioxidative Response Mechanisms to Paraquat-Induced Oxidative Stress in Arabidopsis thaliana

    Science.gov (United States)

    Moustaka, Julietta; Tanou, Georgia; Adamakis, Ioannis-Dimosthenis; Eleftheriou, Eleftherios P.; Moustakas, Michael

    2015-01-01

    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). PMID:26096005

  9. 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.

  10. 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....... 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...... efficiency of antioxidant enzymes of tolerant genotypes could be considered as one of the factors involved in salt tolerance of wheat....

  11. Flagellum-Mediated Biofilm Defense Mechanisms of Pseudomonas aeruginosa against Host-Derived Lactoferrin ▿

    Science.gov (United States)

    Leid, Jeff G.; Kerr, Mathias; Selgado, Candice; Johnson, Chelsa; Moreno, Gabriel; Smith, Alyssa; Shirtliff, Mark E.; O'Toole, George A.; Cope, Emily K.

    2009-01-01

    Chronic infection with the gram-negative organism Pseudomonas aeruginosa is a leading cause of morbidity and mortality in human patients, despite high doses of antibiotics used to treat the various diseases this organism causes. These infections are chronic because P. aeruginosa readily forms biofilms, which are inherently resistant to antibiotics as well as the host's immune system. Our laboratory has been investigating specific mutations in P. aeruginosa that regulate biofilm bacterial susceptibility to the host. To continue our investigation of the role of genetics in bacterial biofilm host resistance, we examined P. aeruginosa biofilms that lack the flgK gene. This mutant lacks flagella, which results in defects in early biofilm development (up to 36 h). For these experiments, the flgK-disrupted strain and the parental strain (PA14) were used in a modified version of the 96-well plate microtiter assay. Biofilms were challenged with freshly isolated human leukocytes for 4 to 6 h and viable bacteria enumerated by CFU. Subsequent to the challenge, both mononuclear cells (monocytes and lymphocytes) and neutrophils, along with tumor necrosis factor alpha (TNF-α), were required for optimal killing of the flgK biofilm bacteria. We identified a cytokine cross talk network between mononuclear cells and neutrophils that was essential to the production of lactoferrin and bacterial killing. Our data suggest that TNF-α is secreted from mononuclear cells, causing neutrophil activation, resulting in the secretion of bactericidal concentrations of lactoferrin. These results extend previous studies of the importance of lactoferrin in the innate immune defense against bacterial biofilms. PMID:19651866

  12. The evolution of defense mechanisms correlate with the explosive diversification of autodigesting Coprinellus mushrooms (Agaricales, Fungi).

    Science.gov (United States)

    Nagy, László G; Házi, Judit; Szappanos, Balázs; Kocsubé, Sándor; Bálint, Balázs; Rákhely, Gábor; Vágvölgyi, Csaba; Papp, Tamás

    2012-07-01

    Bursts of diversification are known to have contributed significantly to the extant morphological and species diversity, but evidence for many of the theoretical predictions about adaptive radiations have remained contentious. Despite their tremendous diversity, patterns of evolutionary diversification and the contribution of explosive episodes in fungi are largely unknown. Here, using the genus Coprinellus (Psathyrellaceae, Agaricales) as a model, we report the first explosive fungal radiation and infer that the onset of the radiation correlates with a change from a multilayered to a much simpler defense structure on the fruiting bodies. We hypothesize that this change constitutes a key innovation, probably relaxing constraints on diversification imposed by nutritional investment into the development of protective tissues of fruiting bodies. Fossil calibration suggests that Coprinellus mushrooms radiated during the Miocene coinciding with global radiation of large grazing mammals following expansion of dry open grasslands. In addition to diversification rate-based methods, we test the hard polytomy hypothesis, by analyzing the resolvability of internal nodes of the backbone of the putative radiation using Reversible-Jump MCMC. We discuss potential applications and pitfalls of this approach as well as how biologically meaningful polytomies can be distinguished from alignment shortcomings. Our data provide insights into the nature of adaptive radiations in general by revealing a deceleration of morphological diversification through time. The dynamics of morphological diversification was approximated by obtaining the temporal distribution of state changes in discrete traits along the trees and comparing it with the tempo of lineage accumulation. We found that the number of state changes correlate with the number of lineages, even in parts of the tree with short internal branches, and peaks around the onset of the explosive radiation followed by a slowdown, most

  13. The antioxidant properties of salicylate derivatives: A possible new mechanism of anti-inflammatory activity.

    Science.gov (United States)

    Borges, Rosivaldo S; Castle, Steven L

    2015-11-01

    The synthesis and antioxidant evaluation by DPPH scavenging of a series of salicylic acid derivatives is described. Gentisic acid and its ester, amide, and amino analogs possess more radical scavenging capacity than salicylic acid and other salicylate derivatives. This property can possibly provide an additional pathway for anti-inflammatory activity through either single electron or hydrogen atom transfer, leading to a new strategy for the design of anti-inflammatory agents.

  14. 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.

  15. Antioxidant activity and mechanism of the abietane-type diterpene ferruginol.

    Science.gov (United States)

    Saijo, H; Kofujita, H; Takahashi, K; Ashitani, T

    2015-01-01

    The antioxidant activity of the abietane-type diterpene ferruginol was evaluated by comparison with that of carnosic acid, ( ± )-α-tocopherol and dibutylhydroxytoluene using 2,2-diphenyl-1-picrylhydrazyl, β-carotene bleaching and linoleic acid assays. Ferruginol had the lowest antioxidant activity of this group using the 2,2-diphenyl-1-picrylhydrazyl and β-carotene methods in polar solvent buffer. However, ferruginol exhibited stronger activity than carnosic acid and α-tocopherol for linoleic acid oxidation under non-solvent conditions. Five peaks corresponding to ferruginol derivatives were detected through GC-MS analysis of the reaction between ferruginol and methyl linoleate. The three reaction products were identified as dehydroferruginol, 7β-hydroxyferruginol and sugiol, and the other two peaks were assumed to be 7α-hydroxyferruginol and the quinone methide derivative of ferruginol. The time course of the reaction suggests that the quinone methide was produced early in the reaction and reacted further to produce dehydroferruginol, 7-hydroxyferruginol and sugiol. Thus, we inferred that quinone methide formation was a key step in the antioxidant reaction of ferruginol.

  16. Dual effects of a mixture of grape pomace (Campbell Early) and Omija fruit ethanol extracts on lipid metabolism and the antioxidant defense system in diet-induced obese mice

    Science.gov (United States)

    Han, Hye Jin; Jung, Un Ju; Kim, Hye-Jin; Moon, Byoung Seok; Cho, Su-Jung; Park, Yong Bok; Lee, Dong Gun

    2015-01-01

    BACKGROUND/OBJECTIVES We investigated the effects of a combination of grape pomace (Vitis labrusca, Campbell Early) and Omija fruit (Schizandra chinensis, Baillon) ethanol extracts on lipid metabolism and antioxidant defense system in diet-induced obese mice. MATERIALS/METHODS Forty male C57BL/6J mice were divided into four groups and fed high-fat diet (control group, CON) or high-fat diet added 0.5% grape pomace extract (GPE), 0.05% Omija fruit extract (OFE) or 0.5% GPE plus 0.05% OFE (GPE+OFE) for 12 weeks. RESULTS In contrast to the GPE- or OFE-supplemented groups, the GPE+OFE group showed significantly lower body weight and white adipose tissue weights than the CON group. Moreover, GPE+OFE supplementation significantly decreased plasma total cholesterol and increased the plasma HDL-cholesterol/total-cholesterol ratio (HTR) compared to the control diet. The hepatic triglyceride level was significantly lower in the GPE+OFE and GPE groups by increasing β-oxidation and decreasing lipogenic enzyme compared to the CON group. Furthermore, GPE+OFE supplementation significantly increased antioxidant enzyme activities with a simultaneous decrease in liver H2O2 content compared to the control diet. CONCLUSIONS Together our results suggest that supplementation with the GPE+OFE mixture may be more effective in improving adiposity, lipid metabolism and oxidative stress in high-fat diet-fed mice than those with GPE and OFE alone. PMID:26060533

  17. 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.

  18. 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.

  19. Leaf Photosynthetic Activity and Antioxidant Defense Associated with Sub1 QTL in Rice Subjected to Submergence and Subsequent Re-aeration

    Institute of Scientific and Technical Information of China (English)

    Debabrata PANDA; Ramani Kumar SARKAR

    2012-01-01

    The influence of submergence on photosynthesis and antioxidant capacities in rice varieties Swarna and Swarna-Sub1 with or without Sub1 QTL were evaluated under control,simulated complete submergence and subsequent re-aeration.The leaf photosynthetic rate and stomatal conductance decreased in the both varieties during the progression of submergence as compared to the control plants,but significant varietal differences were observed after 1 d of submergence.Submergence also altered the PSll activity,as reflected in a decrease in the values of Fo,Fm and Fv/Fm and degradation of chlorophyll,more in Swama than in Swarna-Sub1.During early submergence period,the activities of superoxide dismutase (SOD),ascorbate peroxidase (APX),dehydroascorbate reductase (DHAR),glutathione reductase (GR) against reactive oxygen species were increased in the both varieties.However,with the progress of submergence period (after 7 d),the activities of SOD,catalase (CAT),APX,guaiacol peroxidase (GPX),GR and DHAR declined,more in Swama than in Swarna-Sub1.During re-aeration,Swarna-Sub1 showed significant increase of above antioxidant enzymes but not in Swarna.Swama-Sub1 improves photosynthetic activity,showing higher photosynthetic rate compared to Swarna under submergence and subsequent re-aeration because of less degradation of chlorophyll,higher stomatal conductance,and efficient PSll activity along with better antioxidant protection from oxidative damage.

  20. Antioxidative Defense Responses to lead-induced Oxidative Stress in Glycine max L. CV. Merrill grown in Different pH Gradient

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    Mishra, Pankaj Kishor

    2013-04-01

    Full Text Available Physiological and biochemical changes as well as the activities of anti-oxidative enzymes under lead (Pb2+ phytotoxicity were investigated in 20 days old soybean (Glycine max L. seedlings grown hydroponically in the laboratory under different pH conditions. The rapid uptake of Pb 2+ was observed immediately after the start of treatment. The quantity of accumulation of Pb2+ was much higher in roots than in shoots, its level rising with increasing pH from 3.0 to 8.0 . Not only that, an oxidative stress conditions were observed due to increased level of superoxide anion radical and hydrogen peroxide in shoots and root cells of 20 days old seedlings when treated with Pb(NO32 at a concentration of 0, 500, 1000 and 2000 μM. Spectrometric assays of seedlings showed increased level of activities of antioxidant enzymes like catalase, peroxidase and glutathione reductase. The presence of thiobarbituric acid reacting substances (TBARS indicates the enhanced lipid peroxidation compared to controls. The alteration in the activities of the antioxidant enzymes and the induction of lipid peroxidation reflects the presence of Pb2+, which may cause oxidative stress.

  1. Determination of Carbonyl Group Content in Plasma Proteins as a Useful Marker to Assess Impairment in Antioxidant Defense in Patients with Eales′ Disease

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    Rajesh Mohanraj

    2004-01-01

    Full Text Available Purpose: Formation of protein carbonyl groups is considered an early biomarker for the oxidant/antioxidant barrier impairment in various inflammatory diseases. We evaluated the intensity of free radical reactions in patients with Eales′ disease, an idiopathic inflammatory condition of the retina. Methods: Twenty patients with Eales′ disease in active vasculitis stage, 15 patients with Eales′ disease in healed vasculitis stage and 20 healthy control subjects were recruited for the study. Plasma protein carbonyl groups,plasma glutathione (GSH superoxide dismutase (SOD activity and thiobarbituric acid reactive substances (TBARS were determined in erythrocytes. Results: Plasma protein carbonyl content was elevated by a factor of 3.5 and 1.8 respectively in active and healed vasculitis stages. The increase of carbonyl group content in active and healed stage of patients with Eales′ disease correlated with diminished SOD activity and GSH content. There was also increased accumulation of TBARS in active and healed vasculitis stages of Eales′ disease, and this correlated with diminished SOD activity. Conclusion: Our results showed that protein carbonyl group content increases with severity of Eales′ disease. The increase in carbonyl content correlated with diminished antioxidant status. This confirms an earlier report that free radical mediated tissue damage occurs in Eales′ disease. The determination of protein carbonyl content may be used as a simple biomarker to monitor the efficacy of antioxidant supplementation in controlling retinal vasculitis in patients with Eales′ disease.

  2. Neuroinflammatory contributions to pain after SCI: roles for central glial mechanisms and nociceptor-mediated host defense.

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    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.

  3. Plasma HDL reduces nonesterified fatty acid hydroperoxides originating from oxidized LDL: a mechanism for its antioxidant ability.

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    Kotosai, Mari; Shimada, Sachiko; Kanda, Mai; Matsuda, Namiko; Sekido, Keiko; Shimizu, Yoshibumi; Tokumura, Akira; Nakamura, Toshiyuki; Murota, Kaeko; Kawai, Yoshichika; Terao, Junji

    2013-06-01

    The antioxidant property of plasma high-density lipoprotein (HDL) is thought to be involved in potential anti-atherogenic effects but the exact mechanism is not known. We aimed to reveal the contribution of HDL on the elimination of lipid hydroperoxides (LOOH) derived from oxidized low-density lipoprotein (LDL). Oxidized LDL prepared by copper ion-induced oxidation contained nonesterified fatty acid hydroperoxides (FFA-OOH) and lysophosphatidylcholine (lysoPtdCho), in addition to cholesteryl ester hydroperoxides (CE-OOH) and phosphatidylcholine hydroperoxides (PtdCho-OOH). A platelet-activating factor-acetylhydrolase (PAF-AH) inhibitor suppressed formation of FFA-OOH and lysoPtdCho in oxidized LDL. Among LOOH species, FFA-OOH was preferentially reduced by incubating oxidized LDL with HDL. HDL exhibited selective FFA-OOH reducing ability if it was mixed with a liposomal solution containing FFA-OOH, CE-OOH and PtdCho-OOH. Two-electron reduction of the hydroperoxy group to the hydroxy group was confirmed by the formation of 13-hydroxyoctadecadienoic acid from 13-hydroperoxyoctadecadienoic acid in HPLC analyses. This reducing effect was also found in apolipoprotein A-1 (apoA-1). FFA-OOH released from PtdCho-OOH due to PAF-AH activity in oxidized LDL undergo two-electron reduction by the reducing ability of apoA1 in HDL. This preferential reduction of FFA-OOH may participate in the mechanism of the antioxidant property of HDL.

  4. 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.

  5. Rice bran oil prevents neuroleptic-induced extrapyramidal symptoms in rats: Possible antioxidant mechanisms

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    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.

  6. Chemical analysis,antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

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    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 antioxidant power of a local plant,Daucus gracilis(D.gracilis).Methods:The aerial parts of D.gracilis were subjected to hydro distillation by a Clevenger 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 macrodilution 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 μg/mL by the agar dilution method and57.05 μg/mL and 114.1 μg/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 dosedependent 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.

  7. Herbal antioxidant in clinical practice: A review

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    Shashi Alok

    2014-01-01

    Full Text Available 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.

  8. Nutraceutical Antioxidants as Novel Neuroprotective Agents

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    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.

  9. Herbal antioxidant in clinical practice: a review.

    Science.gov (United States)

    Alok, Shashi; Jain, Sanjay Kumar; Verma, Amita; Kumar, Mayank; Mahor, Alok; Sabharwal, Monika

    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.

  10. Assessment of variation in antioxidative defense system in salt-treated pea (Pisum sativum) cultivars and its putative use as salinity tolerance markers.

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    Noreen, Zahra; Ashraf, Muhammad

    2009-11-01

    The present work describes whether the changes in the activities of antioxidant enzymes and the levels of some non-enzymatic antioxidants could be used as markers of salt tolerance in nine genetically diverse pea (Pisum sativum) cultivars. All cultivars were exposed to four levels of NaCl i.e., 0, 40, 80 and 120mM in sand culture. Plant fresh biomass, total phenolics, total soluble proteins, hydrogen peroxide (H(2)O(2)), malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in leaves while different forms of tocopherols (alpha-, gamma- and Delta-tocopherol) in fresh seed of salt-stressed and non-stressed plants were analyzed. On the basis of percent inhibition in shoot biomass at the highest salt level (120mM) cultivars 2001-35, 2001-55 and Climax were ranked as tolerant (percent inhibition less than 60%), 2001-20, 9800-5 and 9800-10 moderately tolerant (percent inhibition 60-70%), and 2001-40, 9200 and Tere 2 salt sensitive (percent inhibition more than 70%). Salt stress markedly enhanced the activities of SOD and POD, levels of total phenolics and gamma- and Delta-tocopherols, and decreased the total soluble proteins and CAT activity, while the internal levels of H(2)O(2) remained unaffected in all pea cultivars. Although salt-induced oxidative stress occurred in all pea cultivars, the response of salt-tolerant and salt-sensitive cultivars with respect to the generation of enzymatic and non-enzymatic metabolites measured in the present study was not consistent. Of different antioxidant enzymes and metabolites analyzed, only CAT activity was found to be a reliable marker of salt tolerance in the set of pea cultivars examined.

  11. Role of two-sided crosstalk between NO and H2S on improvement of mineral homeostasis and antioxidative defense in Sesamum indicum under lead stress.

    Science.gov (United States)

    Amooaghaie, Rayhaneh; Zangene-Madar, Faezeh; Enteshari, Shekoofeh

    2017-05-01

    H2S and NO are two important gasotransmitters that modulate stress responses in plants. There are the contradictory data on crosstalk between NO and H2S in the studies. Hence, in the present study, the role of interplay between NO and H2S was assessed on the Pb tolerance of Sesamum indicum using pharmacological and biochemical approaches. Results revealed that Pb stress reduced the plant growth and the content of photosynthetic pigments and Fv/Fm ratio, increased the lipid peroxidation and the H2O2 content, elevated the endogenous contents of nitric oxide (NO), H2S and enhanced the activities of antioxidant enzymes (except APX). Additionally, concentrations of most mineral ions (K, P, Mg, Fe, Mn and Zn) in both shoots and roots decreased. Pb accumulation in roots was more than it in shoots. Both sodium hydrosulfide (NaHS as a donor of H2S) and sodium nitroprusside (SNP as an NO donor) improved the plant growth, the chlorophyll and carotenoid contents and PSII efficiency, reduced oxidative damage, increased the activities of antioxidant enzymes and reduced the proline content in Pb-stressed plants. Furthermore, both NaHS and SNP significantly restricted the uptake and translocation of Pb, thereby minimizing antagonistic effects of Pb on essential mineral contents in sesame plants. NaHS increased the NO generation and many NaHS-induced responses were completely reversed by cPTIO, as the specific NO scavenger. Applying SNP also enhanced H2S release levels in roots of Pb-stressed plants and only some NO-driven effects were partially weakened by hypotuarine (HT), as the scavenger of H2S.These findings proposed for the first time that two-sided interplay between H2S and NO might confer an increased tolerance to Pb stress via activating the antioxidant systems, reducing the uptake and translocation of Pb, and harmonizing the balance of mineral nutrient.

  12. 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.

  13. 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

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    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

  14. 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.

  15. Exogenous spermidine improves seed germination of white clover under water stress via involvement in starch metabolism, antioxidant defenses and relevant gene expression.

    Science.gov (United States)

    Li, Zhou; Peng, Yan; Zhang, Xin-Quan; Ma, Xiao; Huang, Lin-Kai; Yan, Yan-Hong

    2014-11-05

    This study was designed to determine the effect of exogenous spermidine (Spd) (30 μM) on white clover seed germination under water stress induced by polyethylene glycol 6000. Use of seed priming with Spd improved seed germination percentage, germination vigor, germination index, root viability and length, and shortened mean germination time under different water stress conditions. Seedling fresh weight and dry weight also increased significantly in Spd-treated seeds compared with control (seeds primed with distilled water). Improved starch metabolism was considered a possible reason for this seed invigoration, since seeds primed with Spd had significantly increased α-amylase/β-amylase activities, reducing sugar, fructose and glucose content and transcript level of β-amylase gene but not transcript level of α-amylase gene. In addition, the physiological effects of exogenous Spd on improving seeds' tolerance to water deficit during germination were reflected by lower lipid peroxidation levels, better cell membrane stability and significant higher seed vigour index in seedlings. Enhanced antioxidant enzyme activities (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase), ascorbate-glutathione cycle (ASC-GSH cycle) and transcript level of genes encoding antioxidant enzymes induced by exogenous Spd may be one of the critical reasons behind acquired drought tolerance through scavenging of reactive oxygen species (ROS) in water-stressed white clover seeds. The results indicate that Spd plays an important function as a stress-protective compound or physiological activator.

  16. Exogenous Spermidine Improves Seed Germination of White Clover under Water Stress via Involvement in Starch Metabolism, Antioxidant Defenses and Relevant Gene Expression

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    Zhou Li

    2014-11-01

    Full Text Available This study was designed to determine the effect of exogenous spermidine (Spd (30 μM on white clover seed germination under water stress induced by polyethylene glycol 6000. Use of seed priming with Spd improved seed germination percentage, germination vigor, germination index, root viability and length, and shortened mean germination time under different water stress conditions. Seedling fresh weight and dry weight also increased significantly in Spd-treated seeds compared with control (seeds primed with distilled water. Improved starch metabolism was considered a possible reason for this seed invigoration, since seeds primed with Spd had significantly increased α-amylase/β-amylase activities, reducing sugar, fructose and glucose content and transcript level of β-amylase gene but not transcript level of α-amylase gene. In addition, the physiological effects of exogenous Spd on improving seeds’ tolerance to water deficit during germination were reflected by lower lipid peroxidation levels, better cell membrane stability and significant higher seed vigour index in seedlings. Enhanced antioxidant enzyme activities (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase, ascorbate-glutathione cycle (ASC-GSH cycle and transcript level of genes encoding antioxidant enzymes induced by exogenous Spd may be one of the critical reasons behind acquired drought tolerance through scavenging of reactive oxygen species (ROS in water-stressed white clover seeds. The results indicate that Spd plays an important function as a stress-protective compound or physiological activator.

  17. IN VITRO ANTIOXIDANT ACTIVITY OF IPOEMA BILOBA

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    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.

  18. High level resistance against rhizomania disease by simultaneously integrating two distinct defense mechanisms.

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    Ourania I Pavli

    Full Text Available With the aim of achieving durable resistance against rhizomania disease of sugar beet, the employment of different sources of resistance to Beet necrotic yellow vein virus was pursued. To this purpose, Nicotiana benthamiana transgenic plants that simultaneously produce dsRNA originating from a conserved region of the BNYVV replicase gene and the HrpZ(Psph protein in a secreted form (SP/HrpZ(Psph were produced. The integration and expression of both transgenes as well as proper production of the harpin protein were verified in all primary transformants and selfed progeny (T1, T2. Transgenic resistance was assessed by BNYVV-challenge inoculation on T2 progeny by scoring disease symptoms and DAS-ELISA at 20 and 30 dpi. Transgenic lines possessing single transformation events for both transgenes as well as wild type plants were included in inoculation experiments. Transgenic plants were highly resistant to virus infection, whereas in some cases immunity was achieved. In all cases, the resistant phenotype of transgenic plants carrying both transgenes was superior in comparison with the ones carrying a single transgene. Collectively, our findings demonstrate, for a first time, that the combination of two entirely different resistance mechanisms provide high level resistance or even immunity against the virus. Such a novel approach is anticipated to prevent a rapid virus adaptation that could potentially lead to the emergence of isolates with resistance breaking properties.

  19. High level resistance against rhizomania disease by simultaneously integrating two distinct defense mechanisms.

    Science.gov (United States)

    Pavli, Ourania I; Tampakaki, Anastasia P; Skaracis, George N

    2012-01-01

    With the aim of achieving durable resistance against rhizomania disease of sugar beet, the employment of different sources of resistance to Beet necrotic yellow vein virus was pursued. To this purpose, Nicotiana benthamiana transgenic plants that simultaneously produce dsRNA originating from a conserved region of the BNYVV replicase gene and the HrpZ(Psph) protein in a secreted form (SP/HrpZ(Psph)) were produced. The integration and expression of both transgenes as well as proper production of the harpin protein were verified in all primary transformants and selfed progeny (T1, T2). Transgenic resistance was assessed by BNYVV-challenge inoculation on T2 progeny by scoring disease symptoms and DAS-ELISA at 20 and 30 dpi. Transgenic lines possessing single transformation events for both transgenes as well as wild type plants were included in inoculation experiments. Transgenic plants were highly resistant to virus infection, whereas in some cases immunity was achieved. In all cases, the resistant phenotype of transgenic plants carrying both transgenes was superior in comparison with the ones carrying a single transgene. Collectively, our findings demonstrate, for a first time, that the combination of two entirely different resistance mechanisms provide high level resistance or even immunity against the virus. Such a novel approach is anticipated to prevent a rapid virus adaptation that could potentially lead to the emergence of isolates with resistance breaking properties.

  20. Cell wall composition as a maize defense mechanism against corn borers.

    Science.gov (United States)

    Barros-Rios, Jaime; Malvar, Rosa A; Jung, Hans-Joachim G; Santiago, Rogelio

    2011-04-01

    European and Mediterranean corn borers are two of the most economically important insect pests of maize (Zea mays L.) in North America and southern Europe, respectively. Cell wall structure and composition were evaluated in pith and rind tissues of resistant and susceptible inbred lines as possible corn borer resistance traits. Composition of cell wall polysaccharides, lignin concentration and composition, and cell wall bound forms of hydroxycinnamic acids were measured. As expected, most of the cell wall components were found at higher concentrations in the rind than in the pith tissues, with the exception of galactose and total diferulate esters. Pith of resistant inbred lines had significantly higher concentrations of total cell wall material than susceptible inbred lines, indicating that the thickness of cell walls could be the initial barrier against corn borer larvae attack. Higher concentrations of cell wall xylose and 8-O-4-coupled diferulate were found in resistant inbreds. Stem tunneling by corn borers was negatively correlated with concentrations of total diferulates, 8-5-diferulate and p-coumarate esters. Higher total cell wall, xylose, and 8-coupled diferulates concentrations appear to be possible mechanisms of corn borer resistance.

  1. 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

  2. Immune-related transcriptome of Coptotermes formosanus Shiraki workers: the defense mechanism.

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    Full Text Available Formosan subterranean termites, Coptotermes formosanus Shiraki, live socially in microbial-rich habitats. To understand the molecular mechanism by which termites combat pathogenic microbes, a full-length normalized cDNA library and four Suppression Subtractive Hybridization (SSH libraries were constructed from termite workers infected with entomopathogenic fungi (Metarhizium anisopliae and Beauveria bassiana, Gram-positive Bacillus thuringiensis and Gram-negative Escherichia coli, and the libraries were analyzed. From the high quality normalized cDNA library, 439 immune-related sequences were identified. These sequences were categorized as pattern recognition receptors (47 sequences, signal modulators (52 sequences, signal transducers (137 sequences, effectors (39 sequences and others (164 sequences. From the SSH libraries, 27, 17, 22 and 15 immune-related genes were identified from each SSH library treated with M. anisopliae, B. bassiana, B. thuringiensis and E. coli, respectively. When the normalized cDNA library was compared with the SSH libraries, 37 immune-related clusters were found in common; 56 clusters were identified in the SSH libraries, and 259 were identified in the normalized cDNA library. The immune-related gene expression pattern was further investigated using quantitative real time PCR (qPCR. Important immune-related genes were characterized, and their potential functions were discussed based on the integrated analysis of the results. We suggest that normalized cDNA and SSH libraries enable us to discover functional genes transcriptome. The results remarkably expand our knowledge about immune-inducible genes in C. formosanus Shiraki and enable the future development of novel control strategies for the management of Formosan subterranean termites.

  3. Characterization of Hg-phytochelatins complexes in vines (Vitis vinifera cv Malbec) as defense mechanism against metal stress.

    Science.gov (United States)

    Spisso, Adrian A; Cerutti, Soledad; Silva, Fernanda; Pacheco, Pablo H; Martinez, Luis D

    2014-06-01

    An approach to understand vines (Vitis vinifera) defense mechanism against heavy metal stress by isolation and determination of Hg-phytochelatins (PCs) complexes was performed. PCs are important molecules involved in the control of metal concentration in plants. PCs complex toxic metals through -SH groups and stores them inside cells vacuole avoiding any toxic effect of free metals in the cytosol. The Hg-PCs identification was achieved by determination of Hg and S as hetero-tagged atoms. A method involving two-dimensional chromatographic analysis coupled to atomic spectrometry and confirmation by tandem mass spectrometry is proposed. An approach involving size exclusion chromatography coupled to inductively coupled plasma mass spectrometry on roots, stems, and leaves extracts describing Hg distribution according to molecular weight and sulfur associations is proposed for the first time. Medium-low molecular weight Hg-S associations of 29-100 kDa were found, suggesting PCs presence. A second approach employing reversed-phase chromatography coupled to atomic fluorescence spectrometry analysis allowed the determination of Hg-PCs complexes within the mentioned fractions. Chromatograms showed Hg-PC2, Hg-PC3 and Hg-PC4 presence only in roots. Hg-PCs presence in roots was confirmed by ESI-MS/MS analysis.

  4. Mechanical hulling and thermal pre-treatment effects on rapeseed oil antioxidant capacity and related lipophilic and hydrophilic bioactive compounds.

    Science.gov (United States)

    Rękas, Agnieszka; Wroniak, Małgorzata; Siger, Aleksander; Ścibisz, Iwona; Derewiaka, Dorota; Anders, Andrzej

    2017-02-20

    In this study, the effect of rapeseed mechanical hulling and thermal pre-treatment by microwaves (from 2 to 10 min with 2-min intervals, 800 W) and roasting (from 20 to 100 min with 20-min intervals, 165 °C) on the content of phytochemicals in the oil was investigated. Results showed that both pre-treatments applied differentiated the oils in terms of the content of bioactive compounds. In general, oils pressed from hulled and thermally pre-treated seeds contained higher content of tocopherols, PC-8 and phytosterols, while oils pressed from non-hulled and pre-processed seeds had significantly higher concentration of polyphenols. Both microwaving and roasting contributed to an increase of antioxidant capacity of studied oils. The increase of radical scavenging activity of oils was seen mainly in hydrophilic fraction of oil, which was highly positively correlated with the amount of canolol formed during seeds heating.

  5. Linking chloroplast antioxidant defense to carbohydrate availability: the transcript abundance of stromal ascorbate peroxidase is sugar-controlled via ascorbate biosynthesis.

    Science.gov (United States)

    Heiber, Isabelle; Cai, Wenguo; Baier, Margarete

    2014-01-01

    All genes encoding chloroplast antioxidant enzymes are nuclear-encoded and posttranscriptionally targeted to chloroplasts. The transcript levels of most of them decreased upon sucrose feeding like the transcript levels of many genes encoding components of the photosynthetic electron transport chain. However, the transcript abundance of stromal ascorbate peroxidase (s-APX; At4g08390) increased. Due to mild sugar application conditions, the plants kept the phosphorylation status of the ADP+ATP pool and the redox states of the NADPH+NADP+ and the ascorbate pools under control, which excludes them as signals in s-APX regulation. Correlation with ascorbate pool size regulation and comparison of transcript abundance regulation in the starch-biosynthetic mutant adg1, the ascorbate biosynthesis mutant vtc1, and the abscisic acid (ABA) biosynthetic mutant aba2 showed a link between sugar induction of s-APX and ascorbate biosynthesis.

  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

    Science.gov (United States)

    Freitas, Rodrigo Barros; Novaes, Rômulo Dias; Gonçalves, Reggiani Vilela; Mendonça, Bianca Gazolla; Santos, Eliziária Cardoso; Ribeiro, Andréia Queiroz; Lima, Luciana Moreira; Fietto, Luciano Gomes; Peluzio, Maria do Carmo Gouveia

    2016-01-01

    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. PMID:27418954

  7. Salicylic acid alleviates aluminum toxicity in rice seedlings better than magnesium and calcium by reducing aluminum uptake, suppressing oxidative damage and increasing antioxidative defense.

    Science.gov (United States)

    Pandey, Poonam; Srivastava, Rajneesh Kumar; Dubey, R S

    2013-05-01

    Aluminum toxicity is a major constraint to crop production in acid soils. The present study was undertaken to examine the comparative ameliorating effects of salicylic acid, Ca and Mg on Al toxicity in rice (Oryza sativa L.) seedlings grown in hydroponics. Al treatment (0.5 mM AlCl3) caused decrease in plant vigour, loss of root plasma membrane integrity, increased contents of O 2 (∙-) , H2O2, lipid peroxidation, protein carbonyls and decline in the level of protein thiol. Al treatment caused significant changes in activity of antioxidative enzymes in rice seedlings. Exogenously added salicylic acid (60 μM), Ca (1 mM) and Mg (0.25 mM) significantly alleviated Al toxicity effects in the seedlings marked by restoration of growth, suppression of Al uptake, restoration of root plasma membrane integrity and decline in O 2 (∙-) , H2O2, lipid peroxidation and protein carbonyl contents. Salicylic acid, Ca and Mg suppressed Al-induced increase in SOD, GPX and APX activities while it elevated Al-induced decline in CAT activity. By histochemical staining of O 2 (∙-) using NBT and H2O2 using DAB, it was further confirmed that added salicylic acid, Ca or Mg decreased Al-induced accumulation of O 2 (∙-) and H2O2 in the leaf tissues. Results indicate that exogenously added salicylic acid, Ca or Mg alleviates Al toxicity in rice seedlings by suppressing Al uptake, restoring root membrane integrity, reducing ROS level and ROS induced oxidative damage and regulating the level of antioxidative enzyme activities. Further salicylic appears to be superior to Mg and Ca in alleviating Al toxicity effects in rice plants.

  8. 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.

  9. Quercetin protects against heat stroke-induced myocardial injury in male rats: Antioxidative and antiinflammatory mechanisms.

    Science.gov (United States)

    Lin, Xiaojing; Lin, Cheng-Hsien; Zhao, Tingbao; Zuo, Dan; Ye, Zhujun; Liu, Lin; Lin, Mao-Tsun

    2017-03-01

    Heat stroke is characterized by hyperthermia, systemic inflammation, and multiple organ failure including arterial hypotension. This definition can be fulfilled by a rat model of heat stroke used in the present study. Anesthetized animals were exposed to heat exposure (43 °C for 70 min) and then returned to room temperature (26 °C) for recovery. One hour before heat exposure, an intraperitoneal dose of quercetin (30 mg/kg) or vehicle (normal saline 1 ml/kg) was administered to the experimental groups of rats. Additional injection was administered immediately after the onset of heat stroke. Immediately after the onset of heat stroke. Vehicle-treated rats displayed (i) hyperthermia; (ii) suppressed left ventricular function; (iii) decreased contents of cardiac total antioxiant capacity (e.g., superoxide dismutase, glutathione peroxidase, catalase); (iv) increased contents of cardiac oxidative capacity malondialdehyde and thiobarbituric acid reactive substances; (v) increased cardiac levels of pro-inflammatory cytokines tumor necrosis factor-α and interleukin-6; and (vi) decreased cardiac levels of an anti-inflammatory cytokine interleukin 10. Histopathologic and survival observation provided supportive evidence for biochemical analyses. These heat stroke reactions all can be significantly attenuated by quercetin therapy. Our data suggest that quercetin therapy might improve outcomes of heat stroke in rats by attenuating excessive hyperthermia as well as myocardial injury. The protective effects of quercetin could be attributed to anti-lipid peroxidative, anti-oxidant, and anti-inflammatory properties.

  10. Antioxidative mechanism of Lycium barbarum polysaccharides promotes repair and regeneration following cavernous nerve injury

    Institute of Scientific and Technical Information of China (English)

    Zhan-kui Zhao; Hong-lian Yu; Bo Liu; Hui Wang; Qiong Luo; Xie-gang Ding

    2016-01-01

    Polysaccharides extracted from Lycium barbarum exhibit antioxidant properties. We hypothesized that these polysaccharides resist oxida-tive stress-induced neuronal damage following cavernous nerve injury. In this study, rat models were intragastrically administered Lycium barbarum polysaccharides for 2 weeks at 1, 7, and 14 days after cavernous nerve injury. Serum superoxide dismutase and glutathione peroxidase activities signiifcantly increased at 1 and 2 weeks post-injury. Serum malondialdehyde levels decreased at 2 and 4 weeks. At 12 weeks, peak intracavernous pressure, the number of myelinated axons and nicotinamide adenine dinucleotide phosphate-diaphorase-pos-itive nerve ifbers, levels of phospho-endothelial nitric oxide synthase protein and 3-nitrotyrosine were higher in rats administered at 1 day post-injury compared with rats administered at 7 and 14 days post-injury. These ifndings suggest that application of Lycium barbarum polysaccharides following cavernous nerve crush injury effectively promotes nerve regeneration and erectile functional recovery. This neu-roregenerative effect was most effective in rats orally administered Lycium barbarum polysaccharides at 1 day after cavernous nerve crush injury.

  11. Tri-iodo thyronine regulates antioxidant enzyme activities in different cell fractions through a mechanism sensitive to actinomycin D in a teleost, Anabas testudineus (Bloch).

    Science.gov (United States)

    Saumya, S M; Sreejith, P; Vijayasree, A S; Divya, L; Manju, M; Oommen, O V

    2006-08-01

    The present study evaluated the effects of hyperthyroid state on lipid peroxidation and antioxidant enzymes in the crude (CF), post nuclear (PNF) and mitochondrial fractions (MF) of the fish liver. The in vivo injection of T3 (200ng) did not change the lipid peroxidation products, malondialdehyde (MDA) and conjugated dienes (CD), while actinomycin D (10microg), a potent mRNA inhibitor when administered with T3 increased them. The antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) had an increased activity in CF and MF of hyperthyroid group to compete the increased oxidative stress, but actinomycin D partially inhibited the T3-induced activity. SOD and CAT activities in PNF of hyperthyroid group had no change, the glutathione concentration varied depending on the GPx and GR activity. Hyperthyroidism decreased the protein content, while simultaneous administration of actinomycin D inhibited the T3 action of elevating the protein content. The results suggest that the antioxidant defense status in A. testudineus is modulated by thyroid hormone, through an action sensitive to actinomycin D.

  12. Antioxidant activities and molecular mechanisms of the ethanol extracts of Baccharis propolis and Eucalyptus propolis in RAW64.7 cells.

    Science.gov (United States)

    Zhang, Jianglin; Shen, Xiaoge; Wang, Kai; Cao, Xueping; Zhang, Cuiping; Zheng, Huoqing; Hu, Fuliang

    2016-10-01

    Context Numerous studies have reported that propolis possesses strong antioxidant activities. However, their antioxidant molecular mechanisms are unclear. Objective We utilize ethanol extracts of Chinese propolis (EECP) as a reference to compare ethanol extracts of Eucalyptus propolis (EEEP) with ethanol extracts of Baccharis propolis (EEBGP) based on their antioxidant capacities and underlying molecular mechanisms. Materials and methods HPLC and chemical analysis are utilized to evaluate compositions and antioxidant activities. ROS-eliminating effects of EEBGP (20-75 μg/mL), EEEP (1.25-3.75 μg/mL) and EECP (1.25-5 μg/mL) are also determined by flow cytometry analysis. Moreover, we compared antioxidant capacities by determining their effects on expressions of antioxidant genes in RAW264.7 cells with qRT-PCR, western blot and confocal microscopy analysis. Results EEBGP mainly contains chlorogenic acid (8.98 ± 0.86 mg/g), kaempferide (11.18 ± 8.31 mg/g) and artepillin C (107.70 ± 10.86 mg/g), but EEEP contains 10 compositions, whereas EECP contains 17 compositions. Meantime, although EEEP shows DPPH (IC50 19.55 ± 1.28), ABTS (IC50 20.0 ± 0.31) and reducing power (2.70 ± 0.08 mmol TE/g) better than EEBGP's DPPH (IC50 43.85 ± 0.54), ABTS (IC50 38.2 ± 0.33) and reducing power (1.53 ± 0.05 mmol TE/g), EEBGP exerts much higher ROS inhibition rate (40%) than EEEP (under 20%). Moreover, EEBGP strengthen antioxidant system by activating p38/p-p38 and Erk/p-Erk kinase via accelerating nucleus translocation of Nrf2. EEEP and EECP improve antioxidant gene expression only via Erk/p-Erk kinase-Nrf2 signalling pathway. Discussion and conclusion EEBGP and EEEP exert antioxidant activities via different molecular mechanisms, which may depend on chemical compositions.

  13. Monitoring antioxidant defenses and free radical production in space-flight, aviation and railway engine operators, for the prevention and treatment of oxidative stress, immunological impairment, and pre-mature cell aging.

    Science.gov (United States)

    De Luca, C; Deeva, I; Mariani, S; Maiani, G; Stancato, A; Korkina, L

    2009-01-01

    Degenerative diseases, immune impairment, and premature ageing commonly affect professional categories exposed to severe environmental and psychological stress. Among these, cosmonauts routinely experience extreme conditions due to microgravity, space radiation, altered oxygen supply, physical and mental fatigue during training, spaceflight, and post-flight. Long route aviation pilots display elevated oncogenic risk, connected with cosmic radiation overexposure, and high mortality rates for cardiovascular causes. Engine drivers, like pilots, are affected by health consequences of psycho-emotional stress, and burnout syndrome. The free radical (FR)/antioxidant (AO) imbalance is a common feature in all these pathological conditions. To assess the effective relevance of oxidative stress, we analyzed blood and urine reliable markers of FR production and AO defenses in 12 Russian cosmonauts, 55 airline pilots, 63 train engine drivers, and 50 age-matched controls by measuring the following: (a) lipophilic/hydrophilic low-molecular weight AO and AO enzyme activities, (b) nitric oxide, superoxide anion, hydroperoxide production, and (c) urinary catecholamine/serotonine metabolites and lipoperoxidation markers. Cosmonauts showed elevated granulocyte superoxide and nitric oxide production, increased erythrocyte superoxide dismutase activity and glutathione oxidation, and drastically decreased plasma/leucocyte lipophilic AO levels (P monitoring of clinical biochemistry laboratory markers of AO/FR status, to tailor individually specific AO supplementation and diet regimen, and monitor treatment outcomes.

  14. Borderline personality organization in violent offenders: correlations of identity diffusion and primitive defense mechanisms with antisocial features, neuroticism, and interpersonal problems.

    Science.gov (United States)

    Leichsenring, Falk; Kunst, Heike; Hoyer, Jürgen

    2003-01-01

    Although theoretical assumptions and empirical evidence suggest an association between borderline personality disorder (BPD) and antisocial behavior or even antisocial personality disorder (APD), there is no study relating the psychodynamic aspects of BPD to antisocial behavior. In this study, the authors tested the correlation between the structural criteria of borderline personality organization (BPO)--that is, identity diffusion, primitive defense mechanisms, and reality testing--and antisocial features, neuroticism, and interpersonal problems. A sample of imprisoned violent offenders (N = 91) was studied using the Antisocial Personality Questionnaire (APQ), the Borderline Personality Inventory (BPI), the Neo-Five-Factor-Inventory (Neo-FFI), and the Inventory of Interpersonal Problems (IIP). Significant correlations were predicted and found between the BPI scales of identity diffusion, primitive defense mechanisms, impaired reality testing, and fear of closeness and antisocial features, neuroticism, agreeableness, and interpersonal problems. The results are consistent with both object relations theory and attachment theory.

  15. Dysfunctionality of the xylem in Olea europaea L. Plants associated with the infection process by Verticillium dahliae Kleb. Role of phenolic compounds in plant defense mechanism.

    Science.gov (United States)

    Báidez, Ana G; Gómez, Pedro; Del Río, José A; Ortuño, Ana

    2007-05-02

    Xylem ultrastructural modification and the possible participation of phenolic compounds in the natural defense or resistance mechanisms of olive plants infected with Verticillium dahliae Kleb. were studied. Microscopic study showed that the mycelium propagated and passed from one element to another through the pit. The formation of tyloses and aggregates contributed to obstruction of the xylem lumen. In vivo changes in the levels of these phenolic compounds in infected olive plants and their antifungal activity against Verticillium dahliae Kleb., as revealed by in vitro study, strongly suggest that they are involved in natural defense or resistance mechanisms in this plant material, the most active being quercetin and luteolin aglycons, followed by rutin, oleuropein, luteolin-7-glucoside, tyrosol, p-coumaric acid, and catechin. .

  16. Dietary flavanols exert different effects on antioxidant defenses and apoptosis/proliferation in Caco-2 and SW480 colon cancer cells.

    Science.gov (United States)

    Ramos, Sonia; Rodríguez-Ramiro, Ildefonso; Martín, María Angeles; Goya, Luis; Bravo, Laura

    2011-12-01

    Flavanols intake has been associated with reduced risk of cancer. In this study, the anticarcinogenic effects of the flavanols epicatechin (EC), epicatechin-gallate (ECG) and procyanidin B2 (PB2) on Caco-2 and SW480 colon cancer cells were investigated. Catechins showed different cytotoxicity depending on the cell line. ECG displayed strong growth inhibitory effects against SW480 cells, but was ineffective on Caco-2 cells. In contrast, PB2 did not affect Caco-2 cells, whereas promoted cell growth in SW480 cells and EC had no obvious effects on any cell line. Exposure of SW480 cells to ECG led to apoptosis as determined by caspase-3 activity, imbalance among Bcl-2 anti- and pro-apoptotic protein levels, ERK activation and AKT inhibition, whereas PB2 treatment enhanced phospho-AKT and phospho-ERK levels. Incubation of Caco-2 cells with ECG increased glutathione levels without affecting the expression of pro- and anti-apoptotic Bcl-2 proteins, AKT or ERK. The results suggest that the different cytotoxicity of flavanols is caused by their different activity and the degree of differentiation of the colon cancer cell line. Thus, ECG induced apoptosis in SW480 cells and contributed to the cytotoxic effect, whereas ECG enhanced the antioxidant potential in Caco-2 cells. PB2 activated cell proliferation and survival/proliferation pathways in SW480 cells.

  17. Polyamine and nitric oxide crosstalk: Antagonistic effects on cadmium toxicity in mung bean plants through upregulating the metal detoxification, antioxidant defense and methylglyoxal detoxification systems.

    Science.gov (United States)

    Nahar, Kamrun; Hasanuzzaman, Mirza; Alam, Md Mahabub; Rahman, Anisur; Suzuki, Toshisada; Fujita, Masayuki

    2016-04-01

    Cadmium (Cd) contamination is a serious agricultural and environmental hazard. The study investigates cross-protection roles of putrescine (Put, 0.2 mM) and nitric oxide (sodium nitroprusside; SNP, 1 mM) in conferring Cd (CdCl2, 1.5 mM) tolerance in mung bean (Vigna radiata L. cv. BARI Mung-2) seedlings. Cadmium stress increased root and shoot Cd content, reduced growth, destroyed chlorophyll (chl), modulated proline (Pro) and reduced leaf relative water content (RWC), increased oxidative damage [lipid peroxidation, H2O2 content, O2(∙-) generation rate, lipoxygenase (LOX) activity], methylglyoxal (MG) toxicity. Put and/or SNP reduced Cd uptake, increasd phytochelatin (PC) content, reduced oxidative damage enhancing non-enzymatic antioxidants (AsA and GSH) and activities of enzymes [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST), and glutathione peroxidase (GPX)]. Exogenous Put and/or SNP modulated endogenous polyamines, PAs (putrescine, Put; spermidine, Spd; spermine, Spm), and NO; improved glyoxalase system in detoxifying MG and improved physiology and growth where combined application showed better effects which designates possible crosstalk between NO and PAs to confer Cd-toxicity tolerance.

  18. A time course assessment of changes in reactive oxygen species generation and antioxidant defense in hydroponically grown wheat in response to lead ions (Pb2+).

    Science.gov (United States)

    Kaur, Gurpreet; Singh, Harminder Pal; Batish, Daizy Rani; Kohli, Ravinder Kumar

    2012-10-01

    We examined the effect of Pb(2+) (8 and 40 mg l(-1)) on reactive oxygen species generation and alterations in antioxidant enzymes in hydroponically grown wheat at 24, 72, and 120 h after exposure. Pb(2+) toxicity was more pronounced on root growth, and it correlated with the greater Pb accumulation in roots. Pb exposure (40 mg l(-1)) enhanced superoxide anion, H(2)O(2), and MDA content in wheat roots by 1.9- to 2.2-folds, 56-255%, and 41-90%, respectively, over the control. Pb-induced loss of membrane integrity was confirmed by the enhanced electrolyte leakage and in vivo histochemical localization. Activities of scavenging enzymes, superoxide dismutases and catalases, enhanced in Pb-treated wheat roots by 1.4- to 5.7-folds over that in the control. In contrast, the activities of ascorbate and guaiacol peroxidases and glutathione reductases decreased significantly, suggesting their non-involvement in detoxification process. The study concludes that Pb(2+)-induced oxidative damage in wheat roots involve greater H(2)O(2) accumulation and the deactivation of the related scavenging enzymes.

  19. 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.

  20. Crocin prevents haloperidol-induced orofacial dyskinesia: possible an antioxidant mechanism

    Science.gov (United States)

    Kamyar, Marzyeh; Razavi, Bibi Marjan; Hasani, Faezeh Vahdati; Mehri, Soghra; Foroutanfar, Amir; Hosseinzadeh, Hossein

    2016-01-01

    Objective(s): Long-term treatment with antipsychotics causes serious side effects such as tardive dyskinesia that characterized by abnormal movements in the orofacial region. Oxidative stress in the brain specific area is implicated in the pathophysiology of tardive dyskinesia. In this study the protective effect of crocin on haloperidol-induced orofacial dyskinesia was evaluated. Materials and Methods: Haloperidol (1 mg/kg, IP) and crocin (10, 20 and 40 mg/kg, IP) were administrated to rats for 21 days. Behavioral assessments such as orofacial dyskinesia movements, open field test and elevated plus maze (EPM) were evaluated every week. Malondealdehyde (MDA) and glutathione (GSH) levels in the hippocampus, cortex and striatum were also measured. Results: Haloperidol increased vacuous chewing movements (VCMs) and tongue protrusions (TPs) in rats and co-administration of crocin (20 and 40 mg/kg) significantly reduced them. Furthermore, haloperidol decreased the locomotor and exploratory activities (rearing) in the open field test and decreased the percentage of entries into open arms and the percentage of the time spent on open arms in the EPM. Pretreatment with crocin (10 mg/kg) modified haloperidol effects on these behavioral parameters. Haloperidol induced lipid peroxidation in three brain regions, whereas crocin co-administration reduced the MDA and restored the decreased GSH levels. Conclusion: Our finding suggests that oxidative stress has an important role in the development of tardive dyskinesia. Crocin showed protective effect against haloperidol induced tardive dyskinesia and as a potent naturally antioxidant could be a new and useful drug and a possible therapeutic option for the treatment of tardive dyskinesia. PMID:27872703

  1. On the DDoS defense mechanism analysis%关于DDoS防御机制分析

    Institute of Scientific and Technical Information of China (English)

    简校荣

    2013-01-01

      DDoS攻击是当前因特网面临的主要威胁之一。据相关统计显示,DDoS攻击在近年来的数量一直呈上升趋势,人们在实践中充分认识到了DDoS攻击的破坏性,其能够使得整个网络瘫痪好几个小时。随着诸如Trinoo、TFN2K等DDoS攻击工具的广泛传播,计算机网络在面临DDoS攻击方面的风险不断增加。本篇文章就这个对网络造成巨大威胁的DDoS进行了深入的研究,并科学分析了关于DDoS防御机制。%DDoS attack is one of the main threats in the current Internet. According to related statistics, DDoS attacks in recent years, the number has been on the upward trend, people fully understand the practice to devastating DDoS attacks, the paralysis of the entire network can be made several hours. With the widespread DDoS attack tools such as Trinoo, TFN2K, increasing the risk of computer network faced DDoS attacks. This article poses a great threat to the network DDoS-depth research and scientific analysis on DDoS defense mechanisms.

  2. Modulation of Melanogenesis and Antioxidant Status of Melanocytes in Response to Phototoxic Action of Doxycycline.

    Science.gov (United States)

    Rok, Jakub; Buszman, Ewa; Beberok, Artur; Delijewski, Marcin; Otręba, Michał; Wrześniok, Dorota

    2015-11-01

    Doxycycline is a commonly used tetracycline antibiotic showing the broad spectrum of antibacterial action. However, the use of this antibiotic is often connected with the risk of phototoxic reactions that lead to various skin disorders. One of the factors influencing the photosensitivity reactions is the melanin content in melanocytes. In this study, the impact of doxycycline and UVA irradiation on cell viability, melanogenesis and antioxidant defense system in cultured normal human epidermal melanocytes (HEMn-DP) was examined. The exposure of cells to doxycycline and UVA radiation resulted in concentration-dependent loss in melanocytes viability and induced melanin biosynthesis. Significant changes were stated in cellular antioxidant enzymes activity: SOD, CAT and GPx, which indicates alterations of antioxidant defense system. The results obtained in vitro may explain the mechanisms of phototoxic reactions that occur in normal human epidermal melanocytes in vivo after exposure of skin to doxycycline and UVA radiation.

  3. 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.

  4. 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.

  5. 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.

  6. Characterization of a 1-cysteine peroxiredoxin from big-belly seahorse (Hippocampus abdominalis); insights into host antioxidant defense, molecular profiling and its expressional response to septic conditions.

    Science.gov (United States)

    Godahewa, G I; Perera, N C N; Elvitigala, Don Anushka Sandaruwan; Jayasooriya, R G P T; Kim, Gi-Young; Lee, Jehee

    2016-10-01

    1-cysteine peroxiredoxin (Prx6) is an antioxidant enzyme that protects cells by detoxifying multiple peroxide species. This study aimed to describe molecular features, functional assessments and potential immune responses of Prx6 identified from the big-belly seahorse, Hippocampus abdominalis (HaPrx6). The complete ORF (666 bp) of HaPrx6 encodes a polypeptide (24 kDa) of 222 amino acids, and harbors a prominent peroxiredoxin super-family domain, a peroxidatic catalytic center, and a peroxidatic cysteine. The deduced amino acid sequence of HaPrx6 shares a relatively high amino acid sequence similarity and close evolutionary relationship with Oplegnathus fasciatus Prx6. The purified recombinant HaPrx6 protein (rHaPrx6) was shown to protect plasmid DNA in the Metal Catalyzed Oxidation (MCO) assay and, together with 1,4-Dithiothreitol (DTT), protected human leukemia THP-1 cells from extracellular H2O2-mediated cell death. In addition, quantitative real-time PCR revealed that HaPrx6 mRNA was constitutively expressed in 14 different tissues, with the highest expression observed in liver tissue. Inductive transcriptional responses were observed in liver and kidney tissues of fish after treating them with bacterial stimuli, including LPS, Edwardsiella tarda, and Streptococcus iniae. These results suggest that HaPrx6 may play an important role in the immune response of the big-belly seahorse against microbial infection. Collectively, these findings provide structural and functional insights into HaPrx6.

  7. Protective Effect of Flos Lonicerae against Experimental Gastric Ulcers in Rats: Mechanisms of Antioxidant and Anti-Inflammatory Action

    Directory of Open Access Journals (Sweden)

    Jung-Woo Kang

    2014-01-01

    Full Text Available Flos Lonicerae is one of the oldest and most commonly prescribed herbs in Eastern traditional medicine to treat various inflammatory diseases. In the present study, we investigated the effects of ethyl acetate fraction of Flos Lonicerae (GC-7101 on experimental gastric ulcer models and its mechanisms of action in gastric ulcer healing. The pharmacological activity of GC-7101 was investigated in rats on HCl/EtOH, indomethacin, water immersion restraint stress induced acute gastric ulcer, and acetic-acid-induced subchronic gastric ulcer. To determine its gastroprotective mechanisms, gastric wall mucus secretion, mucosal PGE2, mucosal NO content, nuclear translocation of NF-κB, mRNA expression of inflammatory cytokines, lipid peroxidation and glutathione content, and superoxide dismutase and catalase activities were measured. GC-7101 significantly attenuated development of acute gastric ulcer and accelerated the healing of acetic-acid-induced subchronic gastric ulcer. In HCl/EtOH-induced gastric ulcer, GC-7101 markedly enhanced gastric wall mucus content which was accompanied by increased mucosal PGE2 and NO production. Furthermore, treatment of GC-7101 exhibited anti-inflammatory and antioxidant activities as evidenced by decreased myeloperoxidase activity, NF-κB translocation, inflammatory cytokines mRNA expression, and lipid peroxidation and increased glutathione content and superoxide dismutase and catalase activities. These results demonstrated that GC-7101 possesses strong antiulcerogenic effect by modulating oxidative stress and proinflammatory mediators.

  8. Antinociceptive effects of fisetin against diabetic neuropathic pain in mice: Engagement of antioxidant mechanisms and spinal GABAA receptors.

    Science.gov (United States)

    Zhao, Xin; Li, Xin-Lin; Liu, Xin; Wang, Chuang; Zhou, Dong-Sheng; Ma, Qing; Zhou, Wen-Hua; Hu, Zhen-Yu

    2015-12-01

    Peripheral painful neuropathy is one of the most common complications in diabetes and necessitates improved treatment. Fisetin, a naturally occurring flavonoid, has been reported to exert antidepressant-like effect in previous studies. As antidepressant drugs are employed clinically to treat neuropathic pain, this work aimed to investigate whether fisetin possess beneficial effect on diabetic neuropathic pain and explore the mechanism(s). We subjected mice to diabetes by a single intraperitoneal (i.p.) injection of streptozotocin (200mg/kg), and von Frey test or Hargreaves test was used to assess mechanical allodynia or thermal hyperalgesia, respectively. Chronic treatment of diabetic mice with fisetin not only ameliorated the established symptoms of thermal hyperalgesia and mechanical allodynia, but also arrested the development of neuropathic pain when given at low doses. Although chronic fisetin administration did not impact on the symptom of hyperglycemia in diabetic mice, it reduced exacerbated oxidative stress in tissues of spinal cord, dorsal root ganglion (DRG) and sciatic verve. Furthermore, the analgesic actions of fisetin were abolished by repetitive co-treatment with the reactive oxygen species (ROS) donor tert-butyl hydroperoxide (t-BOOH), but potentiated by the ROS scavenger phenyl-N-tert-butylnitrone (PBN). Finally, acute blockade of spinal GABAA receptors by bicuculline totally counteracted such fisetin analgesia. These findings indicate that chronic fisetin treatment can delay or correct neuropathic hyperalgesia and allodynia in mice with type 1 diabetes. Mechanistically, the present fisetin analgesia may be associated with its antioxidant activity, and spinal GABAA receptors are likely rendered as downstream targets.

  9. 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.

  10. Future climate CO2 levels mitigate stress in plants: increased defense or decreased challenge?

    Directory of Open Access Journals (Sweden)

    Hamada eAbdelgawad

    2016-05-01

    Full Text Available AbstractElevated 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.

  11. 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

  12. 镉胁迫对昆虫的毒性效应及昆虫防御机制的研究进展%Toxicity effect of cadmium stress exposure to insects and defense mechanism of insects

    Institute of Scientific and Technical Information of China (English)

    付伟利; 杜移珍; 张敏

    2015-01-01

    Cadmium is one of the important heavy metal pollutants with strong toxicity and wide distribution. It poses a threat to human health and invertebrates,especially to insects. It has been demonstrated that cadmium can infiltrate into insects through respiration ,food intake and so on. It can affect their development,and even induce apoptosis via oxidative damage. Insects can gradually develop defense mechanisms against cadmium with the help of metallothionein,antioxidant enzymes, excretion and heat shock protein. Toxicity effect varies among different species. This paper reviewsed the effect of cadmium on development,cell apoptosis mechanism and defense mechanism in insects.%镉是重要的重金属污染物之一,其毒性大,蓄积性强,易对人类健康造成严重危害,这种危害也涉及到无脊椎动物,尤其是镉胁迫对昆虫的影响已引起人们关注。环境中的镉可通过摄食和呼吸等途径进入昆虫体内,影响昆虫的生长发育,并通过氧化损伤等途径诱导细胞凋亡。昆虫对镉胁迫有一定的防御能力,可在一定程度上依靠金属结合蛋白、抗氧化酶、热休克蛋白的保护作用及排泄行为的解毒作用减少镉对机体的损害。镉的毒性效应可能随昆虫种类不同而不同。本文就镉胁迫对昆虫生长和发育的影响、诱导细胞凋亡的分子机制以及昆虫对镉胁迫的防御机制等研究进展进行回顾综述。

  13. The role of cognitive and affective defense mechanisms in reducing children’s susceptibility to advertising effects

    NARCIS (Netherlands)

    Rozendaal, E.; Buijzen, M.; Valkenburg, P.

    2011-01-01

    The main aim of this study was to develop and test a model of children’s advertising defenses. In this model two paths to reduced advertising susceptibility (i.e., advertised brand attitude) were hypothesized: a cognitive and an affective path. The secondary aim was to compare these paths for two th

  14. Ionizing radiation, antioxidant response and oxidative damage: A meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Einor, D., E-mail: daniel@einor.com [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); Bonisoli-Alquati, A., E-mail: andreabonisoli@gmail.com [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803 (United States); Costantini, D., E-mail: davidcostantini@libero.it [Department of Biology, University of Antwerp, Wilrijk, B-2610, Antwerp (Belgium); Mousseau, T.A., E-mail: mousseau@sc.edu [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); Faculty of Bioscience and Biotechnology, Chubu University, Kasugai (Japan); Møller, A.P., E-mail: anders.moller@u-psud.fr [Laboratoire d' Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, F-91405 Orsay Cedex (France)

    2016-04-01

    One mechanism proposed as a link between exposure to ionizing radiation and detrimental effects on organisms is oxidative damage. To test this hypothesis, we surveyed the scientific literature on the effects of chronic low-dose ionizing radiation (LDIR) on antioxidant responses and oxidative damage. We found 40 publications and 212 effect sizes for antioxidant responses and 288 effect sizes for effects of oxidative damage. We performed a meta-analysis of signed and unsigned effect sizes. We found large unsigned effects for both categories (0.918 for oxidative damage; 0.973 for antioxidant response). Mean signed effect size weighted by sample size was 0.276 for oxidative damage and − 0.350 for antioxidant defenses, with significant heterogeneity among effects for both categories, implying that ionizing radiation caused small to intermediate increases in oxidative damage and small to intermediate decreases in antioxidant defenses. Our estimates are robust, as shown by very high fail-safe numbers. Species, biological matrix (tissue, blood, sperm) and age predicted the magnitude of effects for oxidative damage as well as antioxidant response. Meta-regression models showed that effect sizes for oxidative damage varied among species and age classes, while effect sizes for antioxidant responses varied among species and biological matrices. Our results are consistent with the description of mechanisms underlying pathological effects of chronic exposure to LDIR. Our results also highlight the importance of resistance to oxidative stress as one possible mechanism associated with variation in species responses to LDIR-contaminated areas. - Highlights: • There is interest in variation in metabolic effects of chronic low-dose ionizing radiation • A random effect meta-analysis of effect sizes of radioactive contamination was performed • We found significant effects of radiation on oxidative damage and antioxidant response • We found significant heterogeneity among

  15. Epigallocatechin-3-gallate prevents lipid peroxidation and enhances antioxidant defense system via modulating hepatic nuclear transcription factors in heat-stressed quails.

    Science.gov (United States)

    Sahin, K; Orhan, C; Tuzcu, M; Ali, S; Sahin, N; Hayirli, A

    2010-10-01

    Epigallocatechin-3-gallate (EGCG), a polyphenol derived from green tea, exerts antioxidant effects. Oxidative stress is one of the consequences of heat stress (HS), which also depresses performance in poultry. This experiment was conducted to elucidate the action mode of EGCG in alleviation of oxidative stress in heat-stressed quail (Coturnix coturnix japonica). A total of 180 five-week-old female Japanese quails were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (HS) for 12 wk. Birds in both environments were randomly fed 1 of 3 diets: basal diet and basal diet added with 200 or 400 mg of EGCG/kg of diet. Each of the 2×3 factorially arranged groups was replicated in 10 cages, each containing 3 quails. Performance variables [feed intake (FI) and egg production (EP)], oxidative stress biomarkers [malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)] and hepatic transcription factors [nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)] were analyzed using 2-way ANOVA. Exposure to HS caused reductions in FI by 9.7% and EP by 14.4%, increased hepatic MDA level by 84.8%, and decreased hepatic SOD, CAT, and GSH-Px activities by 25.8, 52.3, and 45.5%, respectively (P<0.0001 for all). The hepatic NF-κB expression was greater (156 vs. 82%) and Nrf2 expression was lower (84 vs. 118%) for quails reared under the HS environment than for those reared under the TN environment (P<0.0001 for both). In response to increasing supplemental EGCG level, there were linear increases in FI from 29.6 to 30.9 g/d and EP from 84.3 to 90.1%/d, linear decreases in hepatic MDA level from 2.82 to 1.72 nmol/g and Nrf2 expression from 77.5 to 123.3%, and linear increases in hepatic SOD (146.4 to 182.2), CAT (36.2 to 47.1), and GSH-Px (13.5 to 18.5) activities (U/mg of protein) and NF-κB expression (149.7 to 87.3%) (P<0.0001 for all). Two

  16. Bone marrow ablation demonstrates that estrogen plays an important role in osteogenesis and bone turnover via an antioxidative mechanism.

    Science.gov (United States)

    Shi, Chunmin; Wu, Jun; Yan, Quanquan; Wang, Rong; Miao, Dengshun

    2015-10-01

    To assess the effect of estrogen deficiency on osteogenesis and bone turnover in vivo, 8-week-old mice were sham-operated or bilaterally ovariectomized (OVX), and after 8 weeks, mechanical bone marrow ablation (BMX) was performed and newly formed bone tissue was analyzed from 6 days to 2 weeks after BMX. Our results demonstrated that OVX mice following BMX displayed 2 reversed phase changes, one phase observed at 6 and 8 days after BMX delayed osteogenesis accompanied by a delay in osteoclastogenesis, and the other phase observed at 12 and 14 days after BMX increased osteoblastic activity and osteoclastic activity. Furthermore, we asked whether impaired osteogenesis caused by estrogen deficiency was associated with increased oxidative stress, and oxidative stress parameters were examined in bone tissue from sham-operated and OVX mice and OVX mice were administrated with antioxidant N-acetyl-l-cysteine (NAC) or vehicle after BMX. Results demonstrated that estrogen deficiency induced oxidative stress in mouse bone tissue with reduced antioxidase levels and activity, whereas NAC administration almost rescued the abnormalities in osteogenesis and bone turnover caused by OVX. Results from this study indicate that estrogen deficiency resulted in primarily impaired osteogenesis and subsequently accelerated bone turnover by increasing oxidative stress and oxidative stress promises to be an effective target in the process of treatment of postmenopausal osteoporosis.

  17. 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.

  18. Antihyperglycemic Potential of Grewia asiatica Fruit Extract against Streptozotocin-Induced Hyperglycemia in Rats: Anti-Inflammatory and Antioxidant Mechanisms.

    Science.gov (United States)

    Khattab, Hala A H; El-Shitany, Nagla A; Abdallah, Inas Z A; Yousef, Fatimah M; Alkreathy, Huda M

    2015-01-01

    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.

  19. The Anti-Oxidant Defense System of the Marine Polar Ciliate Euplotes nobilii: Characterization of the MsrB Gene Family

    Directory of Open Access Journals (Sweden)

    Francesca Ricci

    2017-01-01

    Full Text Available Organisms living in polar waters must cope with an extremely stressful environment dominated by freezing temperatures, high oxygen concentrations and UV radiation. To shed light on the genetic mechanisms on which the polar marine ciliate, Euplotes nobilii, relies to effectively cope with the oxidative stress, attention was focused on methionine sulfoxide reductases which repair proteins with oxidized methionines. A family of four structurally distinct MsrB genes, encoding enzymes specific for the reduction of the methionine-sulfoxide R-forms, were identified from a draft of the E. nobilii transcriptionally active (macronuclear genome. The En-MsrB genes are constitutively expressed to synthesize proteins markedly different in amino acid sequence, number of CXXC motifs for zinc-ion binding, and presence/absence of a cysteine residue specific for the mechanism of enzyme regeneration. The En-MsrB proteins take different localizations in the nucleus, mitochondria, cytosol and endoplasmic reticulum, ensuring a pervasive protection of all the major subcellular compartments from the oxidative damage. These observations have suggested to regard the En-MsrB gene activity as playing a central role in the genetic mechanism that enables E. nobilii and ciliates in general to live in the polar environment.

  20. Captopril and Valsartan May Improve Cogniti ve Function Through Potentiation of the Brain Antioxidant Defense System and Attenuation of Oxidative/Nitrosative Damage in STZ - Induced Dementia in Rat

    Directory of Open Access Journals (Sweden)

    Yasaman Arjmand Abbassi

    2016-12-01

    Full Text Available Purpose: Previous findings have shown the crucial roles of brain renin-angiotensin system (RAS in pathogenesis of Alzheimer’s disease (AD. Since RAS inhibitors may have beneficial effects on dementia and cognitive function in elderly people, the aim of present study was to examine the neuroprotective actions of captopril and valsartan on memory function and neuronal damage in experimental model of AD. Methods: Adult forty male Wistar rats (220-280g were randomly divided into 5 groups; Control, Vehicle, Alzheimer and treatment groups. AD was induced by the injections of streptozotocin (3mg/kg, bilateral intracerebroventricular at days 1&3. Treated rats received orally captopril (50mg/kg/day and valsartan (30mg/kg/day. Memory function and histological assessments were done at termination of experiment. Finally, superoxide dismutase (SOD and catalase (CAT activities as well as malondialdehyde (MDA and NOx contents were determined. Results: There was a significant increase in the mean value of latency in Alzheimer group (66%. Captopril and valsartan considerably decreased this value in both treatment groups (45% and 72%, respectively. In Alzheimer group the activities of brain’s SOD and CAT reduced (40% and 47%, respectively in accompany with an increase in MDA and NOx contents (49% and 50%, respectively. Captopril and valsartan significantly increased the activities of brain’s SOD and CAT concomitant reduction in MDA and NOx contents. Also, histopathological damages noticeably decreased in both treatment groups. Conclusion: Our findings indicate that RAS inhibition by using captopril and valsartan potentiates the antioxidant defense system of brain and reduces oxidative/nitrosative stress in accompany with neuronal damage during AD.

  1. 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.

  2. Quantitative proteomic analysis reveals that antioxidation mechanisms contribute to cold tolerance in plantain (Musa paradisiaca L.; ABB Group) seedlings.

    Science.gov (United States)

    Yang, Qiao-Song; Wu, Jun-Hua; Li, Chun-Yu; Wei, Yue-Rong; Sheng, Ou; Hu, Chun-Hua; Kuang, Rui-Bin; Huang, Yong-Hong; Peng, Xin-Xiang; McCardle, James A; Chen, Wei; Yang, Yong; Rose, Jocelyn K C; Zhang, Sheng; Yi, Gan-Jun

    2012-12-01

    Banana and its close relative, plantain are globally important crops and there is considerable interest in optimizing their cultivation. Plantain has superior cold tolerance compared with 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 °C and subsequently allowed to recover for 24 h at 28 °C. A total of 3477 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, whereas 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 seven differentially expressed, cold-response candidate plantain proteins to validate the proteomics data. Similar analyses of the seven 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 increased 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

  3. Vitamin A: Mechanism of Antioxidant Function%维生素A抗氧化功能的机制

    Institute of Scientific and Technical Information of China (English)

    金鹿; 闫素梅; 史彬林; 郭晓宇

    2015-01-01

    动物机体由于旺盛的新陈代谢会产生大量花生四烯酸( ARA)和一氧化氮( NO) ,进而诱导氧化应激的发生,对细胞产生毒性和损害作用. 维生素A可以有效地调控ARA和NO的生成,在提高机体抗氧化、免疫功能等方面起着重要的作用. 本文主要综述了维生素A对动物ARA和NO生成的调节作用及其相关机理的研究进展,以期对今后深入研究其调节机理、科学补充维生素A及提高机体的抗氧化功能提供理论参考.%Due to vigorous metabolism, animals produce a plenty of arachidonic acid ( ARA) and nitric oxide ( NO) , which leads to the occurrence of oxidative stress, and gives rise to cell toxicity and damage. Vitamin A can effectively regulate ARA and NO production, and plays an important role on improve antioxidant and im-mune function of body. This paper reviewed the regulation of ARA and NO synthesis by vitamin A and its un-derlying mechanisms for the purpose of providing some theoretical and practical evidence for further studies on the regulative mechanisms and vitamin A supplementation technique in the future.

  4. Antioxidant Mechanisms and ROS-Related MicroRNAs in Cancer Stem Cells.

    Science.gov (United States)

    Dando, Ilaria; Cordani, Marco; Dalla Pozza, Elisa; Biondani, Giulia; Donadelli, Massimo; Palmieri, Marta

    2015-01-01

    Increasing evidence indicates that most of the tumors are sustained by a distinct population of cancer stem cells (CSCs), which are responsible for growth, metastasis, invasion, and recurrence. CSCs are typically characterized by self-renewal, the key biological process allowing continuous tumor proliferation, as well as by differentiation potential, which leads to the formation of the bulk of the tumor mass. CSCs have several advantages over the differentiated cancer cell populations, including the resistance to radio- and chemotherapy, and their gene-expression programs have been shown to correlate with poor clinical outcome, further supporting the relevance of stemness properties in cancer. The observation that CSCs possess enhanced mechanisms of protection from reactive oxygen species (ROS) induced stress and a different metabolism from the differentiated part of the tumor has paved the way to develop drugs targeting CSC specific signaling. In this review, we describe the role of ROS and of ROS-related microRNAs in the establishment and maintenance of self-renewal and differentiation capacities of CSCs.

  5. Antioxidant Mechanisms and ROS-Related MicroRNAs in Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Ilaria Dando

    2015-01-01

    Full Text Available Increasing evidence indicates that most of the tumors are sustained by a distinct population of cancer stem cells (CSCs, which are responsible for growth, metastasis, invasion, and recurrence. CSCs are typically characterized by self-renewal, the key biological process allowing continuous tumor proliferation, as well as by differentiation potential, which leads to the formation of the bulk of the tumor mass. CSCs have several advantages over the differentiated cancer cell populations, including the resistance to radio- and chemotherapy, and their gene-expression programs have been shown to correlate with poor clinical outcome, further supporting the relevance of stemness properties in cancer. The observation that CSCs possess enhanced mechanisms of protection from reactive oxygen species (ROS induced stress and a different metabolism from the differentiated part of the tumor has paved the way to develop drugs targeting CSC specific signaling. In this review, we describe the role of ROS and of ROS-related microRNAs in the establishment and maintenance of self-renewal and differentiation capacities of CSCs.

  6. 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.

  7. 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. Antioxidan