Science.gov

Sample records for antioxidant defence system

  1. Antioxidant defence systems in the protozoan pathogen Giardia intestinalis.

    PubMed

    Mastronicola, Daniela; Falabella, Micol; Forte, Elena; Testa, Fabrizio; Sarti, Paolo; Giuffrè, Alessandro

    2016-01-01

    The microaerophilic protist Giardia intestinalis is the causative agent of giardiasis, one of the most common intestinal infectious diseases worldwide. The pathogen lacks not only respiratory terminal oxidases (being amitochondriate), but also several conventional antioxidant enzymes, including catalase, superoxide dismutase and glutathione peroxidase. In spite of this, since living attached to the mucosa of the proximal small intestine, the parasite should rely on an efficient antioxidant system to survive the oxidative and nitrosative stress conditions found in this tract of the human gut. Here, we review current knowledge on the antioxidant defence systems in G. intestinalis, focusing on the progress made over the last decade in the field. The relevance of this research and future perspectives are discussed. PMID:26672398

  2. Responses of foliar antioxidative and photoprotective defence systems of trees to drought: a meta-analysis.

    PubMed

    Wujeska, Agnieszka; Bossinger, Gerd; Tausz, Michael

    2013-10-01

    Current climate change predictions hint to more frequent extreme weather events, including extended droughts, making better understanding of the impacts of water stress on trees even more important. At the individual plant level, stomatal closure as a result of water deficit leads to reduced CO2 availability in the leaf, which can lead to photo-oxidative stress. Photorespiration and the Mehler reaction can maintain electron transport rates under low internal CO2, but result in production of reactive oxygen species (ROS). If electron consumption is decreased, upstream photochemical processes can be affected and light energy is absorbed in excess of photochemical requirements. Trees evolved to cope with excess energy and elevated concentration of ROS by activating photoprotective and antioxidative defence systems. The meta-analysis we present here assessed responses of these defence systems reported in 50 studies. We found responses to vary depending on stress intensity, foliage type and habitat, and on whether experiments were done in the field or in controlled environments. In general, drought increased concentrations of antioxidants and photoprotective pigments. However, severe stress caused degradation of antioxidant concentrations and oxidation of antioxidant pools. Evergreen trees seemed to preferentially reinforce membrane-bound protection systems zeaxanthin and tocopherol, whereas deciduous species showed greater responses in water-soluble antioxidants ascorbic acid and glutathione. Trees and shrubs from arid versus humid habitats vary in their antioxidative and photoprotective defence responses. In field experiments, drought had greater effects on some defence compounds than under controlled conditions. PMID:24178981

  3. Evolution of cubic membranes as antioxidant defence system.

    PubMed

    Deng, Yuru; Almsherqi, Zakaria A

    2015-08-01

    Possibly the best-characterized cubic membrane transition has been observed in the mitochondrial inner membranes of free-living giant amoeba (Chaos carolinense). In this ancient organism, the cells are able to survive in extreme environments such as lack of food, thermal and osmolarity fluctuations and high levels of reactive oxygen species. Their mitochondrial inner membranes undergo rapid changes in three-dimensional organization upon food depletion, providing a valuable model to study this subcellular adaptation. Our data show that cubic membrane is enriched with unique ether phospholipids, plasmalogens carrying very long-chain polyunsaturated fatty acids. Here, we propose that these phospholipids may not only facilitate cubic membrane formation but may also provide a protective shelter to RNA. The potential interaction of cubic membrane with RNA may reduce the amount of RNA oxidation and promote more efficient protein translation. Thus, recognizing the role of cubic membranes in RNA antioxidant systems might help us to understand the adaptive mechanisms that have evolved over time in eukaryotes. PMID:26464785

  4. Evolution of cubic membranes as antioxidant defence system

    PubMed Central

    Deng, Yuru; Almsherqi, Zakaria A.

    2015-01-01

    Possibly the best-characterized cubic membrane transition has been observed in the mitochondrial inner membranes of free-living giant amoeba (Chaos carolinense). In this ancient organism, the cells are able to survive in extreme environments such as lack of food, thermal and osmolarity fluctuations and high levels of reactive oxygen species. Their mitochondrial inner membranes undergo rapid changes in three-dimensional organization upon food depletion, providing a valuable model to study this subcellular adaptation. Our data show that cubic membrane is enriched with unique ether phospholipids, plasmalogens carrying very long-chain polyunsaturated fatty acids. Here, we propose that these phospholipids may not only facilitate cubic membrane formation but may also provide a protective shelter to RNA. The potential interaction of cubic membrane with RNA may reduce the amount of RNA oxidation and promote more efficient protein translation. Thus, recognizing the role of cubic membranes in RNA antioxidant systems might help us to understand the adaptive mechanisms that have evolved over time in eukaryotes. PMID:26464785

  5. Interactive effects of early and later nutritional conditions on the adult antioxidant defence system in zebra finches.

    PubMed

    Noguera, José C; Monaghan, Pat; Metcalfe, Neil B

    2015-07-01

    In vertebrates, antioxidant defences comprise a mixture of endogenously produced components and exogenously obtained antioxidants that are derived mostly from the diet. It has been suggested that early-life micronutritional conditions might influence the way in which the antioxidant defence system operates, which could enable individuals to adjust the activity of the endogenous and exogenous components in line with their expected intake of dietary antioxidants if the future environment resembles the past. We investigated this possibility by experimentally manipulating the micronutrient content of the diet during different periods of postnatal development in the zebra finch (Taeniopygia guttata). Birds that had a low micronutrient diet during the growth phase initially had a lower total antioxidant capacity (TAC) than those reared under a high micronutrient diet, but then showed a compensatory response, so that by the end of the growth phase, the TAC of the two groups was the same. Interestingly, we found an interactive effect of micronutrient intake early and late in development: only those birds that continued with the same dietary treatment (low or high) throughout development showed a significant increase in their TAC during the period of sexual maturation. A similar effect was also found in the level of enzymatic antioxidant defences (glutathione peroxidase; GPx). No significant effects were found in the level of oxidative damage in lipids [malondialdehyde (MDA) levels]. These findings demonstrate the importance of early and late developmental conditions in shaping multiple aspects of the antioxidant system. Furthermore, they suggest that young birds may adjust their antioxidant defences to enable them to 'thrive' on diets rich or poor in micronutrients later in life. PMID:25987737

  6. Effect of 28-homobrassinolide on antioxidant defence system in Raphanus sativus L. under chromium toxicity.

    PubMed

    Sharma, Indu; Pati, Pratap Kumar; Bhardwaj, Renu

    2011-06-01

    Heavy metals have emerged as major environmental contaminants due to rapid industrialization and urbanization. The genotoxic, mutagenic and carcinogenic effects of heavy metal like chromium (Cr) on man, animals and plants have been documented. In plants, accumulation of heavy metals beyond critical levels generates oxidative stress. This stress is generally overcome by antioxidant defence system and stress shielding phytohormones. Thus, the present study has been focused to analyze the effect of one of imperative group of plant hormones, i.e., brassinosteroids (BRs) which have been reported for its protective properties for wide array of environmental stresses. Raphanus sativus L. (Pusa Chetaki) seeds pre-treated with different concentrations of 28-homobrassinolide (28-HBL) were raised under various concentrations of Cr(VI). It was observed that 28-HBL treatment considerably reduced the impact of Cr-stress on seedlings which was evinced upon analysis of morphological and biochemical parameters of 7-days old radish seedlings. The toxic effects of Cr in terms of reduced growth, lowered contents of chlorophyll (Chl), protein, proline; increased malondialdehyde (MDA) content and elevated metal uptake were ameliorated by applications of 28-HBL. Also, the activities of all the antioxidant enzymes except guaiacol peroxidase (POD), increased significantly when subjected to Cr stress in combination with 28-HBL. Overall, seed pre-soaking treatment of 28-HBL at 10(-7) M was most effective in ameliorating Cr stress. The present work emphasizes the protective role of 28-HBL on regulation of antioxidant enzymes and its possible link in amelioration of stress in plants. PMID:21448625

  7. Hypothyroidism alters antioxidant defence system in rat brainstem during postnatal development and adulthood.

    PubMed

    Jena, Srikanta; Bhanja, Shravani

    2014-08-01

    The present investigation was carried out to evaluate alterations in oxidative stress parameter [lipid peroxidation (LPx)] and antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] in rat brainstem in response to neonatal hypothyroidism during development (from birth to 7, 15 and 30 days old) and adulthood (90 days old). Hypothyroidism in rats was induced by feeding the lactating mothers (from the day of parturition till weaning, 25 days old) or directly to the pups with 0.05 % [6-n-propyl 2-thiouracil (PTU)] in drinking water. Increased level of LPx was observed in brainstem of 7 days old hypothyroid rats, accompanied by augmented activities of SOD and GPx. In 15 and 30 days old hypothyroid rat brainstem, a significant decline in LPx was observed. Significantly increased activities of CAT and GPx were observed in 15 and 30 days PTU-treated rats. Decreased level of LPx was observed in brainstem of rats treated with PTU from birth to 30 days followed by withdrawal up to 90 days of age (transient hypothyroidism) as compared to control and persistent treatment of PTU up to 90 days of age. Activities of CAT and GPx were decreased in persistent hypothyroid rats of 90 days old with respect to control and transient hypothyroid rats. On the other hand, SOD activity was decreased in both persistent and transient hypothyroid rats with respect to control rats. These results suggest that the PTU-induced neonatal hypothyroidism modulates the antioxidant defence system during postnatal development and adulthood in brainstem of rats. PMID:24595920

  8. Comparison of enzymatic antioxidant defence systems in different metabolic types of yeasts.

    PubMed

    Koleva, Dafinka I; Petrova, Ventsislava Y; Kujumdzieva, Anna V

    2008-11-01

    The enzymatic defence system in the 2 yeasts Kluyveromyces marxianus and Rhodotorula glutinis, differing in their mode of oxygen uptake and energy generation, was characterized and compared with the well-studied facultatively fermentative Crabtree-positive Saccharomyces cerevisiae strain. Twofold higher superoxide dismutase (SOD) and catalase activities were detected in K. marxianus and R. glutinis when cells were cultured on glucose. Further increases of 10%-15% in SOD activity and 30%-50% in catalase were measured in all studied yeasts strains after transfer to media containing ethanol. An evaluation of the ratio of Cu/Zn SOD / Mn SOD was performed as a measure of the oxidative metabolism. A 20% decrease was observed when the respiratory source of energy was ethanol, with the lowest ratio being observed for the oxidative type of K. marxianus yeasts. Electrophoretic analysis revealed that all tested strains possess active Cu/Zn and Mn SODs. A reverse electrophoretic mobility pattern of K. marxianus and R. glutinis SOD enzymes was observed in comparison with the same couple in S. cerevisiae. The investigation of electrophoretic profile of catalase enzymes showed that alongside their different taxonomic status and fermentative capacity, all tested strains possess 2 separate catalases. The role of antioxidant enzymes in preventing oxidant-induced cytotoxicity (treatment with hydrogen peroxide, paraquat, and menadione) was shown. PMID:18997852

  9. Single-nucleotide polymorphisms within the antioxidant defence system and associations with aggressive prostate cancer

    PubMed Central

    Abe, Miyako; Xie, Wanling; Regan, Meredith M.; King, Irena B.; Stampfer, Meir J.; Kantoff, Philip W.; Oh, William K.; Chan, June M.

    2010-01-01

    Objective To study the effects of oxidative stress on prostate cancer development as the exact biological mechanisms behind the relationship remain uncertain. We previously reported a statistically significant interaction between circulating selenium levels, variants in the superoxide dismutase 2 gene (SOD2; rs4880), and risk of developing prostate cancer and presenting with aggressive prostate cancer. Patients and methods We genotyped men with localized/regional prostate cancer for 26 loci across eight genes that are central to cellular antioxidant defence: glutathione peroxidase (GPX1, GPX4), peroxisome proliferator-activated receptor γ coactivator (PPARGC1A, PPARGC1B), SOD1, SOD2, and SOD3, and ‘X-ray repair complementing defective repair in Chinese hamster cell 1’ (XRCC1). Among 489 men, we examined the relationships between genotypes, circulating selenium levels, and risk of presenting with aggressive prostate cancer at diagnosis, as defined by stage, grade and prostate-specific antigen (PSA) level (213 aggressive cases). Results Two variants in SOD2 were significantly associated with the risk of aggressive prostate cancer (rs17884057, odds ratio 0.83, 95% confidence interval 0.70–0.99; and rs4816407, 1.27, 1.02–1.57); men with A alleles at rs2842958 in SOD2 had lower plasma selenium levels (median 116 vs 121.8 μg/L, P = 0.03); and the association between plasma selenium levels and risk of aggressive prostate cancer was modified by SOD1 (rs10432782) and SOD2 (rs2758330). Conclusion While this study was cross-sectional and these associations might be due to chance, further research is warranted on the potential important role of antioxidant defence in prostate cancer. PMID:20477822

  10. Brassinosteroids alleviate high-temperature injury in Ficus concinna seedlings via maintaining higher antioxidant defence and glyoxalase systems

    PubMed Central

    Jin, Song Heng; Li, Xue Qin; Wang, G. Geoff; Zhu, Xiang Tao

    2015-01-01

    Although brassinosteroids (BRs) play crucial roles in plant development and stress tolerance, the mechanisms by which they have these effects are poorly understood. Here, we investigated the possible mechanism of exogenously applied BRs on reactive oxygen species (ROS), antioxidant defence and methylglyoxal (MG) detoxification systems in Ficus concinna seedlings grown under high-temperature (HT) stress for 48 h. Our results showed that the activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPX) and glyoxalase II (Gly II) were increased under two levels of HT stress. Compared with control the activities of catalase (CAT) and dehydroascorbate reductase (DHAR) were not changed due to HT stress. The activities of glutathione reductase (GR), monodehydroascorbate reductase (MDHAR) and glyoxalase I (Gly I) were increased only at moderate HT stress. Despite these protective mechanisms, HT stress induced oxidative stress in F. concinna seedlings, as indicated by the increased levels of ROS, malondialdehyde (MDA) and MG, and the reductions in chlorophyll levels and relative water content. The contents of reduced glutathione (GSH) and ascorbate (AsA) were not changed under moderate HT stress. Spraying with 24-epibrassinolide (EBR) alone had little influence on the non-enzymatic antioxidants and the activities of antioxidant enzymes. However, EBR pretreatment under HT stress resulted in an increase in GSH and AsA content, maintenance of high redox state of GSH and AsA, and enhanced ROS and MG detoxification by further elevating the activities of SOD, GST, GPX, APX, MDHAR, GR, DHAR, Gly I and Gly II, as evident by lower level of ROS, MDA and MG. It may be concluded that EBR could alleviate the HT-induced oxidative stress by increasing the enzymatic and non-enzymatic antioxidant defence, and glyoxalase systems in F. concinna seedlings. PMID:25609563

  11. Effect of temperature acclimation on the liver antioxidant defence system of the Antarctic nototheniids Notothenia coriiceps and Notothenia rossii.

    PubMed

    Machado, Cintia; Zaleski, Tania; Rodrigues, Edson; Carvalho, Cleoni Dos Santos; Cadena, Silvia Maria Suter Correia; Gozzi, Gustavo Jabor; Krebsbach, Priscila; Rios, Flávia Sant'Anna; Donatti, Lucélia

    2014-01-01

    The aim of this study was to determine whether endemic Antarctic nototheniid fish are able to adjust their liver antioxidant defence system in response to the temperature increase. The activity of the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) enzymes as well as the content of non-enzymatic oxidative stress markers such as reduced glutathione (GSH), lipid peroxidation (LPO) and protein carbonyl (PC) were measured in the liver of two Antarctic fish species, Notothenia rossii and Notothenia coriiceps after 1, 3 and 6days of exposure to temperatures of 0°C and 8°C. The GST activity showed a downregulation in N. rossii after 6days of exposure to the increased temperature. The activity profiles of GST and GR in N. rossii and of GPx in N. coriiceps also changed as a consequence of heating to 8°C. The GSH content increased by heating to 8°C after 3days in N. coriiceps and after 6days in N. rossii. The content of malondialdehyde (MDA), a LPO marker, showed a negative modulation by the heating to 8°C in N. rossii after 3days of exposure to temperatures. Present results show that heating to 8°C influenced the levels and profiles of the antioxidant enzymes and defences over time in the nototheniid fish N. rossii and N. coriiceps. PMID:24607634

  12. Glutathione-induced drought stress tolerance in mung bean: coordinated roles of the antioxidant defence and methylglyoxal detoxification systems

    PubMed Central

    Nahar, Kamrun; Hasanuzzaman, Mirza; Alam, Md. Mahabub; Fujita, Masayuki

    2015-01-01

    Drought is considered one of the most acute environmental stresses presently affecting agriculture. We studied the role of exogenous glutathione (GSH) in conferring drought stress tolerance in mung bean (Vigna radiata L. cv. Binamoog-1) seedlings by examining the antioxidant defence and methylglyoxal (MG) detoxification systems and physiological features. Six-day-old seedlings were exposed to drought stress (−0.7 MPa), induced by polyethylene glycol alone and in combination with GSH (1 mM) for 24 and 48 h. Drought stress decreased seedling dry weight and leaf area; resulted in oxidative stress as evidenced by histochemical detection of hydrogen peroxide (H2O2) and O2⋅− in the leaves; increased lipid peroxidation (malondialdehyde), reactive oxygen species like H2O2 content and O2⋅− generation rate and lipoxygenase activity; and increased the MG level. Drought decreased leaf succulence, leaf chlorophyll and relative water content (RWC); increased proline (Pro); decreased ascorbate (AsA); increased endogenous GSH and glutathione disulfide (GSSG) content; decreased the GSH/GSSG ratio; increased ascorbate peroxidase and glutathione S-transferase activities; and decreased the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and catalase. The activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) increased due to drought stress. In contrast to drought stress alone, exogenous GSH enhanced most of the components of the antioxidant and glyoxalase systems in drought-affected mung bean seedlings at 24 h, but GSH did not significantly affect AsA, Pro, RWC, leaf succulence and the activities of Gly I and DHAR after 48 h of stress. Thus, exogenous GSH supplementation with drought significantly enhanced the antioxidant components and successively reduced oxidative damage, and GSH up-regulated the glyoxalase system and reduced MG toxicity, which played a significant role in improving the physiological features and drought

  13. Crucial Roles of Systemic and Tissue Lipid Peroxidation Levels and Anti-Oxidant Defences Following Contrast Agent Application

    PubMed Central

    Sitar, Gungor; Kucuk, Mehmet; Erinc Sitar, Mustafa; Yasar, Ozgur; Aydin, Seval; Yanar, Karolin; Cakatay, Ufuk; Buyukpınarbasili, Nur

    2016-01-01

    Background One of the most important side effects of contrast pharmaceutical agents, which are used very common in routine radiology practice, is contrast induced nephropathy. Even ischemia, oxidative stress and osmolality related cytotoxic effects are considered, the molecular mechanisms underlying this pathology have not been identified completely yet. Objectives The aim of the current study was to reveal the role of oxidative stress and antioxidant enzymatic defence mechanisms in the aetiopathogenesis of contrast-induced nephropathy. We also studied possible alleviating effects of N-acetylcysteine (NAC), a potent antioxidant, to obtain extra information regarding the molecular mechanisms underlying this pathology. Materials and Methods This is an clinical-experimental study, This study was conducted of Istanbul/Turkey between September 15, 2012 and April 15, 2013. Three groups of male rats were randomly set up as a control group (C), a 100 mg/kg intraperitoneal NAC + 7 mL/kg contrast agent group (N + CIN) and a 7 mL/kg intraperitoneal contrast agent group (CIN). They were placed in individual metabolic cages 48 hours after agent administration to obtain 24-hour urine samples. Renal function tests (albumin, urea, creatinine, total protein) were conducted, oxidative stress parameters (Cu, Zn superoxide dismutase activity - Cu, Zn-SOD; advanced oxidation protein products - AOPP; protein carbonyls - PCO; total thiol groups - T-SH; and lipid hydroperoxides -LHP) were measured and tissues were analysed histopathologically. Results Compared with the control group, groups CIN and N + CIN had significantly higher urea and LHP levels (P < 0.05 and P < 0.001, respectively) and significantly lower Cu, Zn-SOD activity and creatinine clearance (P < 0.05). There was no statistically significant difference between the groups in PCO or AOPP levels despite differences in descriptive statistics. Conclusions Contrast-agent-induced nephropathic changes are more closely related to

  14. Markers of antioxidant defence system and lipid peroxidation in peripheral blood of female patients with chronic idiopathic urticaria.

    PubMed

    Kasperska-Zajac, Alicja; Brzoza, Zenon; Polaniak, Renata; Rogala, Barbara; Birkner, Ewa

    2007-03-01

    Oxidative stress is an important event in lesional skin of patients with chronic idiopathic urticaria (CIU). In the present study, we assessed blood oxidant/antioxidant status of patients suffering from CIU with positive response to autologous serum skin test (ASST) and with negative ASST, to improve our understanding of biological processes and the part of oxidative stress in this disease. Activities of manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (Cu/ZnSOD), glutathione peroxidase (GSH-PX), and catalase (CAT) as indices of enzymatic antioxidant capacity, as well as malondialdehyde (MDA) level as a maker of lipid peroxidation were measured in plasma and erythrocytes from 14 CIU female patients showing positive ASST, 31 CIU female patients with negative ASST and in 19 sex- and age-matched healthy subjects. The antioxidant enzyme activity in plasma and in erythrocytes did not differ significantly among the three groups. Also, the plasma and erythrocytes MDA levels were similar in the three groups. Based on our results, it seems that systemic activity of the enzymatic antioxidants (CuZn/SOD, MnSOD, GSH-Px, and CAT) as well as level of lipid peroxidation determined by MDA may not be increased in the course of immune-inflammatory processes associated with CIU. We also suggest that the systemic oxidant/antioxidant status of CIU patients, showing positive response to ASST, may not be different from that of CIU patients with negative ASST. PMID:17171548

  15. Antioxidant defence systems and generation of reactive oxygen species in osteosarcoma cells with defective mitochondria: effect of selenium.

    PubMed

    Wojewoda, Marta; Duszyński, Jerzy; Szczepanowska, Joanna

    2010-01-01

    Mitochondrial diseases originate from mutations in mitochondrial or nuclear genes encoding for mitochondrial proteome. Neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) syndrome is associated with the T8993G transversion in ATP6 gene which results in substitution at the very conservative site in the subunit 6 of mitochondrial ATP synthase. Defects in the mitochondrial respiratory chain and the ATPase are considered to be accompanied by changes in the generation of reactive oxygen species (ROS). This study aimed to elucidate effects of selenium on ROS and antioxidant system of NARP cybrid cells with 98% of T8993G mutation load. We found that selenium decreased ROS generation and increased the level and activity of antioxidant enzymes such as glutathione peroxidase (GPx) and thioredoxin reductase (TrxR). Therefore, we propose selenium to be a promising therapeutic agent not only in the case of NARP syndrome but also other diseases associated with mitochondrial dysfunctions and oxidative stress. PMID:20138159

  16. Abnormal antioxidant defence in some tissues of congenitally obese mice.

    PubMed Central

    Capel, I D; Dorrell, H M

    1984-01-01

    The concentration of lipoperoxides (estimated as thiobarbituric acid-reactive material) and some components of the antioxidant defence system have been compared in various tissues of lean and congenitally obese mice. NADPH-stimulated lipoperoxide generation in vitro was significantly higher in microsomes (microsomal fractions) prepared from obese hepatic tissue than lean. Plasma, liver and brain lipoperoxide concentration was significantly higher in obese mice. In blood derived from obese mice the concentration of non-enzymic antioxidants including caeruloplasmin and vitamin A was higher, but hepatic retinol concentration was lower in these animals. In all the tissues assayed the glutathione peroxidase activity against H2O2 was less than its activity against cumene hydroperoxide. Assayed with either substrate, glutathione peroxidase activity was significantly higher in the brain and blood of obese mice than their lean counterparts. Conversely, liver glutathione peroxidase was decreased in obese animals, representing 43% of the activity of the lean-mouse liver enzyme against H2O2 and 81% of the cumene hydroperoxide-reducing activity. The liver of obese mice had significantly less, and the kidneys more, oxidized glutathione than the corresponding tissues of lean mice. Further investigations on hepatic tissue indicated that glutathione reductase activity was lower in the obese animals, but there was no significant difference between glucose-6-phosphate dehydrogenase activity in obese and lean mice. PMID:6721863

  17. Temporal variation in the antioxidant defence system and lipid peroxidation in the gills and mantle of hydrothermal vent mussel Bathymodiolus azoricus

    NASA Astrophysics Data System (ADS)

    Company, Rui; Serafim, Angela; Cosson, Richard; Fiala-Médioni, Aline; Dixon, David; João Bebianno, Maria

    2006-07-01

    Hydrothermal vent mussels are exposed continually to toxic compounds, including high metal concentrations and other substances like dissolved sulphide, methane and natural radioactivity. Fluctuations in these parameters appear to be common because of the characteristic instability of the hydrothermal environment. Temporal variation in the antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidases (Total GPx), selenium dependent glutathione peroxidases (Se-GPx)), metallothioneins and lipid peroxidation (LPO) in the gills and mantle of the mussel Bathymodiolus azoricus from Menez-Gwen hydrothermal vent site was evaluated and related to the accumulated metal concentrations (Ag, Cu, Cd, Fe, Mn and Zn) in the tissues. Maximum antioxidant enzyme activities in the gills were detected in the beginning of summer, followed by a gradual decrease throughout the following months. One year after, the levels of antioxidant enzyme activities were similar to those reported one year before. LPO in this tissue exhibited a similar temporal variation trend. A different pattern of temporal variation in antioxidant enzyme activities was observed in the mantle, with a gradual increase from summer to the end of autumn (November). LPO in the mantle exhibited an almost reverse trend of temporal variation to that of antioxidant enzyme activities in this tissue. Antioxidant defences in the gills of B. azoricus were significantly enhanced with increasing concentrations of Ag, Cu and Mn, while negative relationships between antioxidant enzymes and Cd, Cu, Mn and Zn concentrations in the mantle were observed, suggesting different pathways of reactive oxygen species (ROS) production and that these tissues responded differently to the metal accumulation. However, temporal variation in biomarkers of defence and damage were in general similar to coastal bivalve species and can be associated with temporal variations of the physiological status due to reproduction

  18. Comparative analyses of genotoxicity, oxidative stress and antioxidative defence system under exposure of methyl parathion and hexaconazole in barley (Hordeum vulgare L.).

    PubMed

    Dubey, Pragyan; Mishra, Amit Kumar; Singh, Ashok Kumar

    2015-12-01

    The present study aims to evaluate the comparative effects of methyl parathion and hexaconazole on genotoxicity, oxidative stress, antioxidative defence system and photosynthetic pigments in barley (Hordeum vulgare L. variety karan-16). The seeds were exposed with three different concentrations, i.e. 0.05, 0.1 and 0.5 % for 6 h after three pre-soaking durations 7, 17 and 27 h which represents G1, S and G2 phases of the cell cycle, respectively. Ethyl methane sulphonate, a well-known mutagenic agent and double distilled water, was used as positive and negative controls, respectively. The results indicate significant decrease in mitotic index with increasing concentrations of pesticides, and the extent was higher in methyl parathion. Chromosomal aberrations were found more frequent in methyl parathion than hexaconazole as compared to their respective controls. Treatment with the pesticides induced oxidative stress which was evident with higher contents of H2O2 and lipid peroxidation, and the increase was more prominent in methyl parathion. Contents of total phenolics were increased; however, soluble protein content showed a reverse trend. Among the enzymatic antioxidants, activities of superoxide dismutase and peroxidase were significantly up-regulated, and more increase was noticed in hexaconazole. Increments in total chlorophyll and carotenoid contents were observed up to 0.1 % but decreased at higher concentration (0.5 %), and the reductions were more prominent in methyl parathion than hexaconazole as compared to their respective controls. Methyl parathion treatment caused more damage in the plant cells of barley as compared to hexaconazole, which may be closely related to higher genotoxicity and oxidative stress. PMID:26286802

  19. Apigenin Attenuates β-Receptor-Stimulated Myocardial Injury Via Safeguarding Cardiac Functions and Escalation of Antioxidant Defence System.

    PubMed

    Buwa, Chhabildas C; Mahajan, Umesh B; Patil, Chandragouda R; Goyal, Sameer N

    2016-07-01

    Apigenin (AP) is a flavone in dietary flavonoids reported as strong antioxidant and elite modulator of PPARγ. The current study evaluated the consequence of AP in isoproterenol (ISO)-induced oxidative stress and myocardial infarction during β-adrenergic receptor stimulus in rats by persistent hemodynamic, biochemical and histopathological changes. Rats received AP (25, 50 and 75 mg/kg/day) or vehicle i.p. for 14 days and ISO (100 mg/kg, s.c.) on 13th and 14th days for initiation of cardiotoxicity. ISO-treated rats showed evidence of significant dwindle in systolic and diastolic arterial pressures, maximal positive rate of developed left ventricular pressure. In totting up, a noteworthy diminution in activities of creatine kinase-MB isoenzyme, reduced glutathione, superoxide dismutase, catalase and level along with rise in malondialdehyde content were observed. The shielding function of AP on isoproterenol-induced myocardial damage was observed by attenuating all the endogenous parameters and the membrane-bound enzymes. It was confirmed by histopathological examinations. The effect of AP at the doses of 50 and 75 mg/kg showed added apparent than at the dose of 25 mg/kg. Current study thus provides confirmation for protective effects of AP on myocardium in experimentally induced myocardial infarction. PMID:26186996

  20. An Overview of Seasonal Changes in Oxidative Stress and Antioxidant Defence Parameters in Some Invertebrate and Vertebrate Species

    PubMed Central

    Chainy, Gagan Bihari Nityananda; Paital, Biswaranjan; Dandapat, Jagneswar

    2016-01-01

    Antioxidant defence system, a highly conserved biochemical mechanism, protects organisms from harmful effects of reactive oxygen species (ROS), a by-product of metabolism. Both invertebrates and vertebrates are unable to modify environmental physical factors such as photoperiod, temperature, salinity, humidity, oxygen content, and food availability as per their requirement. Therefore, they have evolved mechanisms to modulate their metabolic pathways to cope their physiology with changing environmental challenges for survival. Antioxidant defences are one of such biochemical mechanisms. At low concentration, ROS regulates several physiological processes, whereas at higher concentration they are toxic to organisms because they impair cellular functions by oxidizing biomolecules. Seasonal changes in antioxidant defences make species able to maintain their correct ROS titre to take various physiological functions such as hibernation, aestivation, migration, and reproduction against changing environmental physical parameters. In this paper, we have compiled information available in the literature on seasonal variation in antioxidant defence system in various species of invertebrates and vertebrates. The primary objective was to understand the relationship between varied biological phenomena seen in different animal species and conserved antioxidant defence system with respect to seasons. PMID:27127682

  1. An Overview of Seasonal Changes in Oxidative Stress and Antioxidant Defence Parameters in Some Invertebrate and Vertebrate Species.

    PubMed

    Chainy, Gagan Bihari Nityananda; Paital, Biswaranjan; Dandapat, Jagneswar

    2016-01-01

    Antioxidant defence system, a highly conserved biochemical mechanism, protects organisms from harmful effects of reactive oxygen species (ROS), a by-product of metabolism. Both invertebrates and vertebrates are unable to modify environmental physical factors such as photoperiod, temperature, salinity, humidity, oxygen content, and food availability as per their requirement. Therefore, they have evolved mechanisms to modulate their metabolic pathways to cope their physiology with changing environmental challenges for survival. Antioxidant defences are one of such biochemical mechanisms. At low concentration, ROS regulates several physiological processes, whereas at higher concentration they are toxic to organisms because they impair cellular functions by oxidizing biomolecules. Seasonal changes in antioxidant defences make species able to maintain their correct ROS titre to take various physiological functions such as hibernation, aestivation, migration, and reproduction against changing environmental physical parameters. In this paper, we have compiled information available in the literature on seasonal variation in antioxidant defence system in various species of invertebrates and vertebrates. The primary objective was to understand the relationship between varied biological phenomena seen in different animal species and conserved antioxidant defence system with respect to seasons. PMID:27127682

  2. Glyphosate-based herbicide exposure causes antioxidant defence responses in the fruit fly Drosophila melanogaster.

    PubMed

    de Aguiar, Lais Mattos; Figueira, Fernanda Hernandes; Gottschalk, Marco Silva; da Rosa, Carlos Eduardo

    2016-01-01

    Glyphosate is a non-selective and post-emergent herbicide that affects plant growth. Animal exposure to this herbicide can lead to adverse effects, such as endocrine disruption, oxidative stress and behavioural disorders. Drosophilids have been utilized previously as an effective tool in toxicological tests. In the present study, the effects of a glyphosate-based herbicide (Roundup [Original]) were investigated regarding oxidative stress, the antioxidant defence system and acetylcholinesterase (AChE) activity in Drosophila melanogaster. Flies (of both genders) that were 1 to 3days old were exposed to different glyphosate concentrations (0.0mg/L=control, 1.0mg/L, 2.0mg/L, 5.0mg/L and 10.0mg/L) in the diet for 24h and 96h. After the exposure periods, reactive oxygen species (ROS) levels, antioxidant capacity against peroxyl radicals (ACAP) and lipid peroxidation (LPO) levels were quantified. In addition, the mRNA expression of antioxidant genes (i.e., keap1, sod, sod2, cat, irc, gclc, gclm, gss, trxt, trxr-1 and trxr-2) was evaluated via RT-PCR. Additionally, AChE activity was evaluated only after the 96h exposure period. The results indicated that Roundup exposure leads to a reduction in ROS levels in flies exposed for 96h. ACAP levels and gene expression of the antioxidant defence system exhibited an increase from 24h, while LPO did not show any significant alterations in both exposure periods. AChE activity was not affected following Roundup exposure. Our data suggest that Roundup exposure causes an early activation of the antioxidant defence system in D. melanogaster, and this can prevent subsequent damage caused by ROS. PMID:26980113

  3. Salinity stress constrains photosynthesis in Fraxinus ornus more when growing in partial shading than in full sunlight: consequences for the antioxidant defence system

    PubMed Central

    Fini, Alessio; Guidi, Lucia; Giordano, Cristiana; Baratto, Maria Camilla; Ferrini, Francesco; Brunetti, Cecilia; Calamai, Luca; Tattini, Massimiliano

    2014-01-01

    plants growing under partial shading more severely than that of plants growing under full sun during summer. The results suggest co-ordination within the antioxidant defence network aimed at detoxifying salt-induced generation of reactive oxygen species. PMID:25006177

  4. Nitric oxide, antioxidants and prooxidants in plant defence responses

    PubMed Central

    Groß, Felicitas; Durner, Jörg; Gaupels, Frank

    2013-01-01

    In plant cells the free radical nitric oxide (NO) interacts both with anti- as well as prooxidants. This review provides a short survey of the central roles of ascorbate and glutathione—the latter alone or in conjunction with S-nitrosoglutathione reductase—in controlling NO bioavailability. Other major topics include the regulation of antioxidant enzymes by NO and the interplay between NO and reactive oxygen species (ROS). Under stress conditions NO regulates antioxidant enzymes at the level of activity and gene expression, which can cause either enhancement or reduction of the cellular redox status. For instance chronic NO production during salt stress induced the antioxidant system thereby increasing salt tolerance in various plants. In contrast, rapid NO accumulation in response to strong stress stimuli was occasionally linked to inhibition of antioxidant enzymes and a subsequent rise in hydrogen peroxide levels. Moreover, during incompatible Arabidopsis thaliana-Pseudomonas syringae interactions ROS burst and cell death progression were shown to be terminated by S-nitrosylation-triggered inhibition of NADPH oxidases, further highlighting the multiple roles of NO during redox-signaling. In chemical reactions between NO and ROS reactive nitrogen species (RNS) arise with characteristics different from their precursors. Recently, peroxynitrite formed by the reaction of NO with superoxide has attracted much attention. We will describe putative functions of this molecule and other NO derivatives in plant cells. Non-symbiotic hemoglobins (nsHb) were proposed to act in NO degradation. Additionally, like other oxidases nsHb is also capable of catalyzing protein nitration through a nitrite- and hydrogen peroxide-dependent process. The physiological significance of the described findings under abiotic and biotic stress conditions will be discussed with a special emphasis on pathogen-induced programmed cell death (PCD). PMID:24198820

  5. Effects of glyphosate on juvenile rainbow trout (Oncorhynchus mykiss): transcriptional and enzymatic analyses of antioxidant defence system, histopathological liver damage and swimming performance.

    PubMed

    Topal, Ahmet; Atamanalp, Muhammed; Uçar, Arzu; Oruç, Ertan; Kocaman, Esat Mahmut; Sulukan, Ekrem; Akdemir, Fatih; Beydemir, Şükrü; Kılınç, Namık; Erdoğan, Orhan; Ceyhun, Saltuk Buğrahan

    2015-01-01

    This study aims to determine the effect of glyphosate on the transcriptional and enzymatic activity of antioxidant metabolism enzymes of juvenile rainbow trout with short term (6, 12, 24, 48 and 96 h) and long term (21 days) exposures followed by a recovery treatment. This study also aims to determine the effects of glyphosate exposure on liver tissue damage and swimming performance due to short term (2.5, 5 and 10 mg/L) and long term (2.5 and 5 mg/L) exposures. Following pesticide administration, ten fish, each as a sample, were caught at 6th, 12th, 24th, 48th and 96th -h for the short term, and at 21st day for the long term exposure study. GPx activity was found to be significantly induced 12 h after the exposure to 2.5 mg/L of glyphosate as compared with the control group. A similar degree of induction was also observed for CAT activity but not for SOD. For long term exposure, except for the GPx activity after exposure to 5 mg/L of glyphosate, the activities of all other enzymes remained on a par with the control group. It was also observed that the levels of gene expression of these enzymes were not comparable with each other. It is assumed that these differences might result from the effect of glyphosate before translation and the possible reasons for this scenario are also discussed. The results of swimming performance are found to be consistent with responses of the antioxidant system, and they are attributed to the energy metabolism. The data are also supported with liver histopathology analysis. PMID:25450935

  6. Rapid evolution of antioxidant defence in a natural population of Daphnia magna.

    PubMed

    Oexle, S; Jansen, M; Pauwels, K; Sommaruga, R; De Meester, L; Stoks, R

    2016-07-01

    Natural populations can cope with rapid changes in stressors by relying on sets of physiological defence mechanisms. Little is known onto what extent these physiological responses reflect plasticity and/or genetic adaptation, evolve in the same direction and result in an increased defence ability. Using resurrection ecology, we studied how a natural Daphnia magna population adjusted its antioxidant defence to ultraviolet radiation (UVR) during a period with increasing incident UVR reaching the water surface. We demonstrate a rapid evolution of the induction patterns of key antioxidant enzymes under UVR exposure in the laboratory. Notably, evolutionary changes strongly differed among enzymes and mainly involved the evolution of UV-induced plasticity. Whereas D. magna evolved a strong plastic up-regulation of glutathione peroxidase under UVR, it evolved a lower plastic up-regulation of glutathione S-transferase and superoxide dismutase and a plastic down-regulation of catalase. The differentially evolved antioxidant strategies were collectively equally effective in dealing with oxidative stress because they resulted in the same high levels of oxidative damage (to lipids, proteins and DNA) and lowered fitness (intrinsic growth rate) under UVR exposure. The lack of better protection against UVR may suggest that the UVR exposure did not increase between both periods. Predator-induced evolution to migrate to lower depths that occurred during the same period may have contributed to the evolved defence strategy. Our results highlight the need for a multiple trait approach when focusing on the evolution of defence mechanisms. PMID:27018861

  7. Neuronal development is promoted by weakened intrinsic antioxidant defences due to epigenetic repression of Nrf2

    PubMed Central

    Bell, Karen F.S.; Al-Mubarak, Bashayer; Martel, Marc-André; McKay, Sean; Wheelan, Nicola; Hasel, Philip; Márkus, Nóra M.; Baxter, Paul; Deighton, Ruth F.; Serio, Andrea; Bilican, Bilada; Chowdhry, Sudhir; Meakin, Paul J.; Ashford, Michael L.J.; Wyllie, David J.A.; Scannevin, Robert H.; Chandran, Siddharthan; Hayes, John D.; Hardingham, Giles E.

    2015-01-01

    Forebrain neurons have weak intrinsic antioxidant defences compared with astrocytes, but the molecular basis and purpose of this is poorly understood. We show that early in mouse cortical neuronal development in vitro and in vivo, expression of the master-regulator of antioxidant genes, transcription factor NF-E2-related-factor-2 (Nrf2), is repressed by epigenetic inactivation of its promoter. Consequently, in contrast to astrocytes or young neurons, maturing neurons possess negligible Nrf2-dependent antioxidant defences, and exhibit no transcriptional responses to Nrf2 activators, or to ablation of Nrf2's inhibitor Keap1. Neuronal Nrf2 inactivation seems to be required for proper development: in maturing neurons, ectopic Nrf2 expression inhibits neurite outgrowth and aborization, and electrophysiological maturation, including synaptogenesis. These defects arise because Nrf2 activity buffers neuronal redox status, inhibiting maturation processes dependent on redox-sensitive JNK and Wnt pathways. Thus, developmental epigenetic Nrf2 repression weakens neuronal antioxidant defences but is necessary to create an environment that supports neuronal development. PMID:25967870

  8. Are diverse signalling pathways integrated in the regulation of arabidopsis antioxidant defence gene expression in response to excess excitation energy?

    PubMed Central

    Mullineaux, P; Ball, L; Escobar, C; Karpinska, B; Creissen, G; Karpinski, S

    2000-01-01

    When low-light-grown Arabidopsis rosettes are partially exposed to excess light (EL), the unexposed leaves become acclimated to excess excitation energy (EEE) and consequent photo-oxidative stress. This phenomenon, termed systemic acquired acclimation (SAA), is associated with redox changes in the proximity of photosystem II, changes in foliar H2O2 content and induction of antioxidant defences. The induction of extra-plastidial antioxidant systems is important in the protection of the chloroplast under EL conditions. A larger range of transcripts encoding different antioxidant defence enzymes may be induced in the systemically acclimated leaves and these include those encoded by the glutathione peroxidase (GPX2) and glutathione-S-transferase (GST) genes, which are also highly induced in the hypersensitive response and associated systemic acquired resistance (SAR) in incompatible plant-pathogen interactions. Furthermore, the expression of the SAR-inducible pathogenesis-related protein gene, PR2, is enhanced in SAA leaves. Wounded leaf tissue also shows enhanced systemic induction of a cytosolic ascorbate peroxidase gene (APX2) under EL conditions. These and other considerations, suggest H2O2 and other reactive oxygen species (ROS) could be the common factor in signalling pathways for diverse environmental stresses. These effects may be mediated by changes in the level and redox state of the cellular glutathione pool. Mutants with constitutive expression of a normally EL-inducible APX2 gene have much reduced levels of foliar glutathione. The expression of APX1 and APX3, encoding cytosolic and peroxisome-associated isoforms, respectively, are also under phytochrome-A-mediated control. The expression of these genes is tightly linked to the greening of plastids in etiolated seedlings. These data suggest that part of the developmental processes that bring about the acclimation of leaves to high light includes the configuration of antioxidant defences. Therefore, the

  9. Early antioxidative defence responses in the aquatic worms (Limnodrilus sp.) in Porsuk Creek in Eskisehir (Turkey).

    PubMed

    Oztetik, Elif; Cicek, Arzu; Arslan, Naime

    2013-07-01

    Certain oligochaeta specimens have been universally applied as bioindicators to reflect the organic and inorganic pollution in rivers and play a major role in the decomposition of pollutants. The aim of this study was to investigate the water quality in Porsuk Creek in Eskisehir (Turkey) through the specimens from two different species that belong to Limnodrilus genus, using their biomonitoring compatibilities for the accumulated trace element concentrations and to describe the applicability of antioxidative systems as biomarkers of pollution in Tubificinae. Therefore, some parameters that serve as biomarkers for antioxidative defence, total protein, glutathione (GSH) contents and glutathione S-transferase (GST) activities, were determined in Limnodrilus hoffmeisteri and Limnodrilus udekemianus. The study was completed with the chemical analysis of the trace elements from these specimens and also from the water samples. As a conclusion, the observed elevation in GSH levels and GST activities reflect the contribution of oxidative stress in toxicity mechanisms due to the accumulation of trace elements, and the study also suggests a general induction of detoxification metabolisms in the presence of several pollutants in benthic sediment-dwelling worms. According to the average value, the trace element levels for two species are as follows: Fe > Al > Zn > Mn > Pb > Cu > Ni > B > Cd = Cr = Hg. As Porsuk Creek is used for many purposes, such as irrigation, drinking water and fish production, discharges of all types of wastes should be under stringent control to avoid the unwanted health effects to its habitants and to humans. PMID:22514119

  10. Endoplasmic reticulum stress triggers ROS signalling, changes the redox state, and regulates the antioxidant defence of Arabidopsis thaliana

    PubMed Central

    Turkan, Ismail

    2014-01-01

    Inefficient chaperone activity in endoplasmic reticulum (ER) causes accumulation of unfolded proteins and is called ER stress, which triggers the unfolded protein response. For proper oxidative protein folding, reactive oxygen species (ROS) such as H2O2 are produced in the ER. Although the role of ROS during abiotic stresses such as salinity is well documented, the role of ER-related ROS production and its signalling is not yet known. Moreover, how H2O2 production, redox regulation, and antioxidant defence are affected in salt-treated plants when ER protein-folding machinery is impaired needs to be elucidated. For this aim, changes in NADPH-oxidase-dependent ROS signalling and H2O2 content at sequential time intervals and after 48h of ER stress, induced by tunicamycin (Tm), salinity, and their combination were determined in Arabidopsis thaliana. The main root growth was inhibited by ER stress, while low levels of Tm caused an increase in lateral root density. Salt stress and Tm induced the expression of ER-stress-related genes (bZIP17, bZIP28, bZIP60, TIN1, BiP1, BiP3) and ERO1. Tm induced expression of RBOHD and RBOHF, which led to an early increase in H2O2 and triggered ROS signalling. This study is the first report that ER stress induces the antioxidant system and the Asada–Halliwell pathway of A. thaliana in a similar way to salinity. ER stress caused oxidative damage, as evident by increased H2O2 accumulation, lipid peroxidation, and protein oxidation. As a result, this study shows that ER stress triggers ROS signalling, changes the redox state, and regulates the antioxidant defence of A. thaliana. PMID:24558072

  11. Anti-Oxidative Defences Are Modulated Differentially in Three Freshwater Teleosts in Response to Ammonia-Induced Oxidative Stress

    PubMed Central

    Giblen, Terri; Zinta, Gaurav; De Rop, Michelle; Asard, Han; Blust, Ronny; De Boeck, Gudrun

    2014-01-01

    Oxidative stress and the antioxidant response induced by high environmental ammonia (HEA) were investigated in the liver and gills of three freshwater teleosts differing in their sensitivities to ammonia. The highly ammonia-sensitive salmonid Oncorhynchus mykiss (rainbow trout), the less ammonia sensitive cyprinid Cyprinus carpio (common carp) and the highly ammonia-resistant cyprinid Carassius auratus (goldfish) were exposed to 1 mM ammonia (as NH4HCO3) for 0 h (control), 3 h, 12 h, 24 h, 48 h, 84 h and 180 h. Results show that HEA exposure increased ammonia accumulation significantly in the liver of all the three fish species from 24 h–48 h onwards which was associated with an increment in oxidative stress, evidenced by elevation of xanthine oxidase activity and levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA). Unlike in trout, H2O2 and MDA accumulation in carp and goldfish liver was restored to control levels (84 h–180 h); which was accompanied by a concomitant increase in superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase activity and reduced ascorbate content. Many of these defence parameters remained unaffected in trout liver, while components of the glutathione redox cycle (reduced glutathione, glutathione peroxidase and glutathione reductase) enhanced to a greater extent. The present findings suggest that trout rely mainly on glutathione dependent defensive mechanism while carp utilize SOD, CAT and ascorbate as anti-oxidative sentinels. Hepatic cells of goldfish appear to utilize each of these protective systems, and showed more effective anti-oxidative compensatory responses towards HEA than carp, while trout were least effective. The present work also indicates that HEA exposure resulted in a relatively mild oxidative stress in the gills of all three species. This probably explains the almost complete lack of anti-oxidative responses in branchial tissue. This research suggests that oxidative stress, as well as the antioxidant

  12. Landscape settings as part of earth wall systems for defence

    NASA Astrophysics Data System (ADS)

    van den Ancker, Hanneke; Jungerius, Pieter Dirk

    2013-04-01

    Remnants of earth wall systems from different periods are preserved in many European countries. They were built for different functions, such as defence, demarcating ownership or keeping wild animals or cattle in or out a terrain, and often changed function over time. Earth walls date from a past in which man had limited access to man- and horsepower. In the case of defence systems, our ancestors made use of the landscape settings to improve the strength. The poster gives an overview of landscape settings used for this purpose, from prehistoric up to medieval age, for building round and linear earth wall defence systems. Round earth walls systems are found on: • High viewpoints along a river, often in combination with marshland at its feet, • Almost completely cut-off meanders of antecedent rivers. This natural setting offered an ideal defence. It allowed an almost 360 degree view and exposed the enemy for a long time when passing the river, while the steep slopes and narrow entrance made the hill fort difficult to access, • Islands in lakes, • Bordering a lake at one side, • Confluences of rivers, • Hills near the sea and a natural harbour with possibilities for defence, • High flat hill tops of medium size with steep sides. Of each situation examples are presented. Linear earth wall defence systems For linear defence earth walls no overview of landscape settings can be given, for lack of sufficient data. The Celtic, 10 m steep Beech Bottom Dyke earth wall system from around 20 A.D. connects two steeply incised river valleys. For building the Hadrian Wall (UK) the Romans made use of earth walls paralleling the steepest cuesta of the Cheviot hills. The Viking Danewerk (Ger), was built on push moraines and used the coastal marsh lands at their feet for defence. And the defence of the earth wall around the Velder (NL, probably 13th century) made use of the many small streams crossing this marshy coversand landscape, by diverting them into a canal

  13. Glycine metabolism and anti-oxidative defence mechanisms in Pseudomonas fluorescens.

    PubMed

    Alhasawi, Azhar; Castonguay, Zachary; Appanna, Nishma D; Auger, Christopher; Appanna, Vasu D

    2015-02-01

    The role of metabolism in anti-oxidative defence is only now beginning to emerge. Here, we show that the nutritionally-versatile microbe, Pseudomonas fluorescens, reconfigures its metabolism in an effort to generate NADPH, ATP and glyoxylate in order to fend off oxidative stress. Glyoxylate was produced predominantly via the enhanced activities of glycine dehydrogenase-NADP(+) (GDH), glycine transaminase (GTA) and isocitrate lyase (ICL) in a medium exposed to hydrogen peroxide (H₂O₂). This ketoacid was utilized to produce ATP by substrate-level phosphorylation and to neutralize reactive oxygen species with the concomitant formation of formate. The latter was also a source of NADPH, a process mediated by formate dehydrogenase-NADP(+) (FDH). The increased activities of phosphoenolpyruvate carboxylase (PEPC) and pyruvate orthophosphate dikinase (PPDK) worked in tandem to synthesize ATP in the H₂O₂-challenged cells that had markedly diminished capacity for oxidative phosphorylation. These metabolic networks provide an effective means of combating ROS and reveal therapeutic targets against microbes resistant to oxidative stress. PMID:25644949

  14. Complement in disease: a defence system turning offensive.

    PubMed

    Ricklin, Daniel; Reis, Edimara S; Lambris, John D

    2016-07-01

    Although the complement system is primarily perceived as a host defence system, a more versatile, yet potentially more harmful side of this innate immune pathway as an inflammatory mediator also exists. The activities that define the ability of the complement system to control microbial threats and eliminate cellular debris - such as sensing molecular danger patterns, generating immediate effectors, and extensively coordinating with other defence pathways - can quickly turn complement from a defence system to an aggressor that drives immune and inflammatory diseases. These host-offensive actions become more pronounced with age and are exacerbated by a variety of genetic factors and autoimmune responses. Complement can also be activated inappropriately, for example in response to biomaterials or transplants. A wealth of research over the past two decades has led to an increasingly finely tuned understanding of complement activation, identified tipping points between physiological and pathological behaviour, and revealed avenues for therapeutic intervention. This Review summarizes our current view of the key activating, regulatory, and effector mechanisms of the complement system, highlighting important crosstalk connections, and, with an emphasis on kidney disease and transplantation, discusses the involvement of complement in clinical conditions and promising therapeutic approaches. PMID:27211870

  15. Effect of probiotic Pediococcus acidilactici on antioxidant defences and oxidative stress of Litopenaeus stylirostris under Vibrio nigripulchritudo challenge.

    PubMed

    Castex, Mathieu; Lemaire, Pierrette; Wabete, Nelly; Chim, Liet

    2010-04-01

    Antioxidant defences and induced oxidative stress tissue damage of the blue shrimp Litopenaeus stylirostris, under challenge with Vibrio nigripulchritudo, were investigated for a 72-h period. For this purpose, L. stylirostris were first infected by immersion with pathogenic V. nigripulchritudo strain SFn1 and then antioxidant defences: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (Gpx), Total antioxidant status (TAS), glutathiones and induced tissue damage (MDA and carbonyl proteins) were determined in the digestive gland at 0, 12, 24, 48 and 72 h post-infection (h.p.i.). In the meantime, TAS was also measured in the blood. Infection level of the shrimps during the challenge was followed by determining V. nigripulchritudo prevalence and load in the haemolymph of the shrimps. Changes in all these parameters during the 72-h.p.i. period were recorded for control shrimps and shrimps previously fed for one month with probiotic Pediococcus acidilactici MA18/5M at 10(7) CFU g(-1) of feed. Our results showed that immersion with V. nigripulchritudo led to maximal infection level in the haemolymph at 24 h.p.i. preceding the mortality peak recorded at 48 h.p.i. Significant decreases in the antioxidant defences were detected from 24 h.p.i. and beyond that time infection leaded to increases in oxidative stress level and tissue damage. Compared to control group, shrimps fed the probiotic diet showed lower infection (20% instead of 45% at 24 h.p.i. in the control group) and mortality (25% instead of 41.7% in the control group) levels. Moreover, infected shrimp fed the probiotic compared to uninfected control shrimps exhibited very similar antioxidant status and oxidative stress level. Compared to the infected control group, shrimps fed the probiotic sustained higher antioxidant defences and lower oxidative stress level. This study shows that bacterial infection leads to oxidative stress in L. stylirostris and highlighted a beneficial effect of P

  16. The protein quality control system manages plant defence compound synthesis.

    PubMed

    Pollier, Jacob; Moses, Tessa; González-Guzmán, Miguel; De Geyter, Nathan; Lippens, Saskia; Vanden Bossche, Robin; Marhavý, Peter; Kremer, Anna; Morreel, Kris; Guérin, Christopher J; Tava, Aldo; Oleszek, Wieslaw; Thevelein, Johan M; Campos, Narciso; Goormachtig, Sofie; Goossens, Alain

    2013-12-01

    Jasmonates are ubiquitous oxylipin-derived phytohormones that are essential in the regulation of many development, growth and defence processes. Across the plant kingdom, jasmonates act as elicitors of the production of bioactive secondary metabolites that serve in defence against attackers. Knowledge of the conserved jasmonate perception and early signalling machineries is increasing, but the downstream mechanisms that regulate defence metabolism remain largely unknown. Here we show that, in the legume Medicago truncatula, jasmonate recruits the endoplasmic-reticulum-associated degradation (ERAD) quality control system to manage the production of triterpene saponins, widespread bioactive compounds that share a biogenic origin with sterols. An ERAD-type RING membrane-anchor E3 ubiquitin ligase is co-expressed with saponin synthesis enzymes to control the activity of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), the rate-limiting enzyme in the supply of the ubiquitous terpene precursor isopentenyl diphosphate. Thus, unrestrained bioactive saponin accumulation is prevented and plant development and integrity secured. This control apparatus is equivalent to the ERAD system that regulates sterol synthesis in yeasts and mammals but that uses distinct E3 ubiquitin ligases, of the HMGR degradation 1 (HRD1) type, to direct destruction of HMGR. Hence, the general principles for the management of sterol and triterpene saponin biosynthesis are conserved across eukaryotes but can be controlled by divergent regulatory cues. PMID:24213631

  17. Influence of cow or goat milk consumption on antioxidant defence and lipid peroxidation during chronic iron repletion.

    PubMed

    Díaz-Castro, Javier; Pérez-Sánchez, Luis J; Ramírez López-Frías, Mercedes; López-Aliaga, Inmaculada; Nestares, Teresa; Alférez, María J M; Ojeda, M Luisa; Campos, Margarita S

    2012-07-14

    Despite Fe deficiency and overload having been widely studied, no studies are available about the influence of milk consumption on antioxidant defence and lipid peroxidation during the course of these highly prevalent cases. The objective of the present study was to assess the influence of cow or goat milk-based diets, either with normal or Fe-overload, on antioxidant defence and lipid peroxidation in the liver, brain and erythrocytes of control and anaemic rats after chronic Fe repletion. Weanling male rats were randomly divided into two groups: a control group receiving a normal-Fe diet (45 mg/kg) and an anaemic group receiving a low-Fe diet (5 mg/kg) for 40 d. Control and anaemic rats were fed goat or cow milk-based diets, either with normal Fe or Fe-overload (450 mg/kg), for 30 or 50 d. Fe-deficiency anaemia did not have any effect on antioxidant enzymes or lipid peroxidation in the organs studied. During chronic Fe repletion, superoxide dismutase (SOD) activity was higher in the group of animals fed the cow milk diet compared with the group consuming goat milk. The slight modification of catalase and glutathione peroxidise activities in animals fed the cow milk-based diet reveals that these enzymes are unable to neutralise and scavenge the high generation of free radicals produced. The animals fed the cow milk diet showed higher rates of lipid peroxidation compared with those receiving the goat milk diet, which directly correlated with the increase in SOD activity. It was concluded that goat milk has positive effects on antioxidant defence, even in a situation of Fe overload, limiting lipid peroxidation. PMID:22018161

  18. Improved antioxidative defence protects insulin-producing cells against homocysteine toxicity.

    PubMed

    Scullion, Siobhan M; Hahn, Claudine; Tyka, Karolina; Flatt, Peter R; McClenaghan, Neville H; Lenzen, Sigurd; Gurgul-Convey, Ewa

    2016-08-25

    Homocysteine (HC) is considered to play an important role in the development of metabolic syndrome complications. Insulin-producing cells are prone to HC toxicity and this has been linked to oxidative stress. However, the exact mechanisms remain unknown. Therefore it was the aim of this study to determine the nature of reactive oxygen species responsible for HC toxicity. Chronic exposure of RINm5F and INS1E insulin-producing cells to HC decreased cell viability and glucose-induced insulin secretion in a concentration-dependent manner and led to a significant induction of hydrogen peroxide generation in the cytosolic, but not the mitochondrial compartment of the cell. Cytosolic overexpression of catalase, a hydrogen peroxide detoxifying enzyme, provided a significant protection against viability loss and hydrogen peroxide generation, while mitochondrial overexpression of catalase did not protect against HC toxicity. Overexpression of CuZnSOD, a cytosolic superoxide dismutating enzyme, also protected against HC toxicity. However, the best protection was achieved in the case of a combined overexpression of CuZnSOD and catalase. Incubation of cells in combination with alloxan resulted in a significant increase of HC toxicity and an increase of hydrogen peroxide generation. Overexpression of CuZnSOD or catalase protected against the toxicity of HC plus alloxan, with a superior protection achieved again by combined overexpression. The results indicate that HC induces oxidative stress in insulin-producing cells by stimulation of superoxide radical and hydrogen peroxide generation in the cytoplasm. The low antioxidative defence status makes the insulin-producing cells very vulnerable to HC toxicity. PMID:27317948

  19. Defence R&D Canada's autonomous intelligent systems program

    NASA Astrophysics Data System (ADS)

    Digney, Bruce L.; Hubbard, Paul; Gagnon, Eric; Lauzon, Marc; Rabbath, Camille; Beckman, Blake; Collier, Jack A.; Penzes, Steven G.; Broten, Gregory S.; Monckton, Simon P.; Trentini, Michael; Kim, Bumsoo; Farell, Philip; Hopkin, Dave

    2004-09-01

    The Defence Research and Development Canada's (DRDC has been given strategic direction to pursue research to increase the independence and effectiveness of military vehicles and systems. This has led to the creation of the Autonomous Intelligent Systems (AIS) prgram and is notionally divide into air, land and marine vehicle systems as well as command, control and decision support systems. This paper presents an overarching description of AIS research issues, challenges and directions as well as a nominal path that vehicle intelligence will take. The AIS program requires a very close coordination between research and implementation on real vehicles. This paper briefly discusses the symbiotic relationship between intelligence algorithms and implementation mechanisms. Also presented are representative work from two vehicle specific research program programs. Work from the Autonomous Air Systems program discusses the development of effective cooperate control for multiple air vehicle. The Autonomous Land Systems program discusses its developments in platform and ground vehicle intelligence.

  20. Modelling an infrared Man Portable Air Defence System

    NASA Astrophysics Data System (ADS)

    Birchenall, Richard P.; Richardson, Mark A.; Brian, Butters; Roy, Walmsley

    2010-09-01

    The global proliferation of shoulder launched IR Man Portable Air Defence Systems (ManPADS) has resulted in the existence of a serious threat to both civilian and military aircraft from terrorist attack. Some of the older generations of ManPADS can be defeated with modern countermeasures but even the most sophisticated protection still has vulnerabilities to the latest family of ManPADS. This paper describes the work undertaken by the authors to model a second generation ManPAD, based on the Russian SA-14, and assess the vulnerabilities of aircraft both with and without flare countermeasures from these systems. The conclusions are the results of over 11,000 simulated firings against targets of varying aspects, velocities and altitudes.

  1. The thioredoxin antioxidant system.

    PubMed

    Lu, Jun; Holmgren, Arne

    2014-01-01

    The thioredoxin (Trx) system, which is composed of NADPH, thioredoxin reductase (TrxR), and thioredoxin, is a key antioxidant system in defense against oxidative stress through its disulfide reductase activity regulating protein dithiol/disulfide balance. The Trx system provides the electrons to thiol-dependent peroxidases (peroxiredoxins) to remove reactive oxygen and nitrogen species with a fast reaction rate. Trx antioxidant functions are also shown by involvement in DNA and protein repair by reducing ribonucleotide reductase, methionine sulfoxide reductases, and regulating the activity of many redox-sensitive transcription factors. Moreover, Trx systems play critical roles in the immune response, virus infection, and cell death via interaction with thioredoxin-interacting protein. In mammalian cells, the cytosolic and mitochondrial Trx systems, in which TrxRs are high molecular weight selenoenzymes, together with the glutathione-glutaredoxin (Grx) system (NADPH, glutathione reductase, GSH, and Grx) control the cellular redox environment. Recently mammalian thioredoxin and glutathione systems have been found to be able to provide the electrons crossly and to serve as a backup system for each other. In contrast, bacteria TrxRs are low molecular weight enzymes with a structure and reaction mechanism distinct from mammalian TrxR. Many bacterial species possess specific thiol-dependent antioxidant systems, and the significance of the Trx system in the defense against oxidative stress is different. Particularly, the absence of a GSH-Grx system in some pathogenic bacteria such as Helicobacter pylori, Mycobacterium tuberculosis, and Staphylococcus aureus makes the bacterial Trx system essential for survival under oxidative stress. This provides an opportunity to kill these bacteria by targeting the TrxR-Trx system. PMID:23899494

  2. Folic acid supplemented goat milk has beneficial effects on hepatic physiology, haematological status and antioxidant defence during chronic Fe repletion.

    PubMed

    Alférez, María J M; Rivas, Emilio; Díaz-Castro, Javier; Hijano, Silvia; Nestares, Teresa; Moreno, Miguel; Campos, Margarita S; Serrano-Reina, Jose A; López-Aliaga, Inmaculada

    2015-02-01

    The aim of the current study was to asses the effect of goat or cow milk-based diets, either normal or Fe-overloaded and folic acid supplement on some aspects of hepatic physiology, enzymatic antioxidant defence and lipid peroxidation in liver, brain and erythrocyte of control and anaemic rats after chronic Fe repletion. 160 male Wistar rats were placed on 40 d in two groups, a control group receiving normal-Fe diet and the Fe-deficient group receiving low Fe diet. Lately, the rats were fed with goat and cow milk-based diets during 30 d, with normal-Fe content or Fe-overload and either with normal folic or folic acid supplemented. Fe-overload increased plasma alanine transaminase and aspartate transaminase levels when cow milk was supplied. Dietary folate supplementation reduced plasma transaminases levels in animals fed goat milk with chronic Fe overload. A remarkable increase in the superoxide dismutase activity was observed in the animals fed cow milk. Dietary folate supplement lead to a decrease on the activity of this enzyme in all the tissues studied with both milk-based diets. A concomitant increment in catalase was also observed. The increase in lipid peroxidation products levels in rats fed cow milk with Fe-overload, suggest an imbalance in the functioning of the enzymatic antioxidant defence. In conclusion, dietary folate-supplemented goat milk reduces both plasma transaminases levels, suggesting a hepatoprotective effect and has beneficial effects in situation of Fe-overload, improving the antioxidant enzymes activities and reducing lipid peroxidation. PMID:25394837

  3. Role of intracellular labile iron, ferritin, and antioxidant defence in resistance of chronically adapted Jurkat T cells to hydrogen peroxide

    PubMed Central

    Al-Qenaei, Abdullah; Yiakouvaki, Anthie; Reelfs, Olivier; Santambrogio, Paolo; Levi, Sonia; Hall, Nick D.; Tyrrell, Rex M.; Pourzand, Charareh

    2014-01-01

    To examine the role of intracellular labile iron pool (LIP), ferritin (Ft), and antioxidant defence in cellular resistance to oxidative stress on chronic adaptation, a new H2O2-resistant Jurkat T cell line “HJ16” was developed by gradual adaptation of parental “J16” cells to high concentrations of H2O2. Compared to J16 cells, HJ16 cells exhibited much higher resistance to H2O2-induced oxidative damage and necrotic cell death (up to 3 mM) and had enhanced antioxidant defence in the form of significantly higher intracellular glutathione and mitochondrial ferritin (FtMt) levels as well as higher glutathione-peroxidase (GPx) activity. In contrast, the level of the Ft H-subunit (FtH) in the H2O2-adapted cell line was found to be 7-fold lower than in the parental J16 cell line. While H2O2 concentrations higher than 0.1 mM fully depleted the glutathione content of J16 cells, in HJ16 cells the same treatments decreased the cellular glutathione content to only half of the original value. In HJ16 cells, H2O2 concentrations higher than 0.1 mM increased the level of FtMt up to 4-fold of their control values but had no effect on the FtMt levels in J16 cells. Furthermore, while the basal cytosolic level of LIP was similar in both cell lines, H2O2 treatment substantially increased the cytosolic LIP levels in J16 but not in HJ16 cells. H2O2 treatment also substantially decreased the FtH levels in J16 cells (up to 70% of the control value). In contrast in HJ16 cells, FtH levels were not affected by H2O2 treatment. These results indicate that chronic adaptation of J16 cells to high concentrations of H2O2 has provoked a series of novel and specific cellular adaptive responses that contribute to higher resistance of HJ16 cells to oxidative damage and cell death. These include increased cellular antioxidant defence in the form of higher glutathione and FtMt levels, higher GPx activity, and lower FtH levels. Further adaptive responses include the significantly reduced

  4. Pea aphid infestation induces changes in flavonoids, antioxidative defence, soluble sugars and sugar transporter expression in leaves of pea seedlings.

    PubMed

    Morkunas, Iwona; Woźniak, Agnieszka; Formela, Magda; Mai, Van Chung; Marczak, Łukasz; Narożna, Dorota; Borowiak-Sobkowiak, Beata; Kühn, Christina; Grimm, Bernhard

    2016-07-01

    The perception of aphid infestation induces highly coordinated and sequential defensive reactions in plants at the cellular and molecular levels. The aim of the study was to explore kinetics of induced antioxidative defence responses in leaf cells of Pisum sativum L.cv. Cysterski upon infestation of the pea aphid Acyrthosiphon pisum at varying population sizes, including accumulation of flavonoids, changes of carbon metabolism, and expression of nuclear genes involved in sugar transport. Within the first 96 h, after A. pisum infestation, flavonoid accumulation and increased peroxidase activity were observed in leaves. The level of pisatin increased after 48 h of infestation and reached a maximum at 96 h. At this time point, a higher concentration of flavonols was observed in the infested tissue than in the control. Additionally, strong post-infestation accumulation of chalcone synthase (CHS) and isoflavone synthase (IFS) transcription products was also found. The levels of sucrose and fructose in 24-h leaves infested by 10, 20, and 30 aphids were significantly lower than in the control. Moreover, in leaves infested by 30 aphids, the reduced sucrose level observed up to 48 h was accompanied by a considerable increase in the expression level of the PsSUT1 gene encoding the sucrose transporter. In conclusion, A. pisum infestation on pea leads to stimulation of metabolic pathways associated with defence. PMID:26239447

  5. Concerted action of reduced glutathione and superoxide dismutase in preventing redox cycling of dihydroxypyrimidines, and their role in antioxidant defence.

    PubMed

    Winterbourn, C C; Munday, R

    1990-01-01

    Dialuric Acid, the reduced form of the beta-cell toxin alloxan, and the related fava bean derivatives divicine and isouramil, autoxidize rapidly in neutral solution by a radical mechanism. GSH promotes redox cycling of each compound, with concomitant GSH oxidation and H2O2 production. With superoxide dismutase present, there is a lag period in which little oxidation occurs, followed by rapid oxidation. GSH extends this lag and decreases the subsequent rate of oxidation, so that with superoxide dismutase and a sufficient excess of GSH, coupled oxidation of GSH and each pyrimidine is almost completely suppressed. This mechanism may be a means whereby GSH in combination with superoxide dismutase protects against the cytotoxic effects of these reactive pyrimidines. Superoxide dismutase may also protect cells against oxidative stress in other situations where GSH acts as a radical scavenger, and we propose that the concerted action of GSH and superoxide dismutase constitutes an important antioxidant defence. PMID:2354807

  6. Beneficial effects of the ethanol extract from the dry matter of a culture broth of Inonotus obliquus in submerged culture on the antioxidant defence system and regeneration of pancreatic beta-cells in experimental diabetes in mice.

    PubMed

    Xu, Hong-Yu; Sun, Jun-En; Lu, Zhen-Ming; Zhang, Xiao-Mei; Dou, Wen-Fang; Xu, Zheng-Hong

    2010-04-01

    The antihyperglycaemic and antilipidperoxidative effects of the ethanol extract from the dry matter of a culture broth (DMCB) of Inonotus obliquus were investigated in alloxan-induced diabetic mice and the possible mechanism of action was also discussed. In alloxan-induced diabetic mice, treatment with the ethanol extract from DMCB of I. obliquus (30 and 60 mg kg(-1) body weight (b.w.) for 21 days) showed a significant decrease in blood glucose level: the percentage reductions on the 7th day were 11.54 and 11.15%, respectively. However, feeding of this drug for three weeks produced reduction of 22.51 and 24.32%. Furthermore, the ethanol extract from the DMCB of I. obliquus treatment significantly decreased serum contents of free fatty acids, total cholesterol, triglycerides and low-density lipoprotein-cholesterol, whereas it effectively increased high-density lipoprotein-cholesterol, insulin levels and hepatic glycogen contents in livers of diabetic mice. Besides this, the ethanol extracts from the DMCB treatment significantly increased catalase, superoxide dismutase and glutathione peroxidase activities, except for decreasing the maleic dialdehyde level in diabetic mice. Histological morphology examination showed that the ethanol extract from the DMCB of I. obliquus restored the damage of pancreatic tissues in mice with diabetes mellitus. The results showed that the ethanol extract from the DMCB of I. obliquus possesses significant antihyperglycaemic, antilipidperoxidative and antioxidant effects in alloxan-induced diabetic mice. PMID:20397104

  7. Individual and interactive effects of elevated carbon dioxide and ozone on tropical wheat (Triticum aestivum L.) cultivars with special emphasis on ROS generation and activation of antioxidant defence system.

    PubMed

    Mishra, Amit Kumar; Rai, Richa; Agrawal, S B

    2013-04-01

    The effects of elevated CO2 and O3, singly and in combination were investigated on various physiological, biochemical and yield parameters of two locally grown wheat (Triticum aestivum L.) cultivars (HUW-37 and K-9107) in open top chambers (OTCs). Elevated CO2 stimulated photosynthetic rate (Ps) and Fv/Fm ratio and reduced the stomatal conductance (gs). Reactive oxygen species, lipid peroxidation, anti-oxidative enzymes, ascorbic acid and total phenolics were higher, whereas Ps, gs, Fv/Fm, protein and photosynthetic pigments were reduced in elevated O3 exposure, as compared to their controls. Under elevated CO2 + O3, elevated levels of CO2 modified the plant performance against O3 in both the cultivars. Elevated CO2 caused significant increase in economic yield. Exposure to elevated O3 caused significant reduction in yield and the effect was cultivar-specific. The study concluded that elevated CO2 ameliorated the negative impact of elevated O3 and cultivar HUW-37 was more sensitive to elevated O3 than K-9107. PMID:23720888

  8. In vitro antioxidant and antigenotoxic potentials of myricetin-3-o-galactoside and myricetin-3-o-rhamnoside from Myrtus communis: modulation of expression of genes involved in cell defence system using cDNA microarray.

    PubMed

    Hayder, Nawel; Bouhlel, Ines; Skandrani, Ines; Kadri, Malika; Steiman, Régine; Guiraud, Pascale; Mariotte, Anne-Marie; Ghedira, Kamel; Dijoux-Franca, Marie-Geneviève; Chekir-Ghedira, Leila

    2008-04-01

    Antioxidant activity of myricetin-3-o-galactoside and myricetin-3-o-rhamnoside, isolated from the leaves of Myrtus communis, was determined by the ability of each compound to inhibit xanthine oxidase activity, lipid peroxidation and to scavenge the free radical 1,1-diphenyl-2-picrylhydrazyl. Antimutagenic activity was assessed using the SOS chromotest and the Comet assay. The IC50 values of lipid peroxidation by myricetin-3-o-galactoside and myricetin-3-o-rhamnoside are respectively 160 microg/ml and 220 microg/ml. At a concentration of 100 microg/ml, the two compounds showed the most potent inhibitory effect of xanthine oxidase activity by respectively, 57% and 59%. Myricetin-3-o-rhamnoside was a very potent radical scavenger with an IC50 value of 1.4 microg/ml. Moreover, these two compounds induced an inhibitory activity against nifuroxazide, aflatoxine B1 and H2O2 induced mutagenicity. The protective effect exhibited by these molecules was also determined by analysis of gene expression as response to an oxidative stress using a cDNA micro-array. Myricetin-3-o-galactoside and myricetin-3-o-rhamnoside modulated the expression patterns of cellular genes involved in oxidative stress, respectively (GPX1, TXN, AOE372, SEPW1, SHC1) and (TXNRD1, TXN, SOD1 AOE372, SEPW1), in DNA damaging repair, respectively (XPC, LIG4, RPA3, PCNA, DDIT3, POLD1, XRCC5, MPG) and (TDG, PCNA, LIG4, XRCC5, DDIT3, MSH2, ERCC5, RPA3, POLD1), and in apoptosis (PARP). PMID:18222061

  9. Thermal Imaging And Its Application In Defence Systems

    NASA Astrophysics Data System (ADS)

    Akula, Aparna; Ghosh, Ripul; Sardana, H. K.

    2011-10-01

    Thermal imaging is a boon to the armed forces namely army, navy and airforce because of its day night working capability and ability to perform well in all weather conditions. Thermal detectors capture the infrared radiation emitted by all objects above absolute zero temperature. The temperature variations of the captured scene are represented as a thermogram. With the advent of infrared detector technology, the bulky cooled thermal detectors having moving parts and demanding cryogenic temperatures have transformed into small and less expensive uncooled microbolometers having no moving parts, thereby making systems more rugged requiring less maintenance. Thermal imaging due to its various advantages has a large number of applications in military and defence. It is popularly used by the army and navy for border surveillance and law enforcement. It is also used in ship collision avoidance and guidance systems. In the aviation industry it has greatly mitigated the risks of flying in low light and night conditions. They are widely used in military aviation to identify, locate and target the enemy forces. Recently, they are also being incorporated in civil aviation for health monitoring of aircrafts.

  10. The Protective Role of Antioxidants in the Defence against ROS/RNS-Mediated Environmental Pollution

    PubMed Central

    Poljšak, Borut; Fink, Rok

    2014-01-01

    Overproduction of reactive oxygen and nitrogen species can result from exposure to environmental pollutants, such as ionising and nonionising radiation, ultraviolet radiation, elevated concentrations of ozone, nitrogen oxides, sulphur dioxide, cigarette smoke, asbestos, particulate matter, pesticides, dioxins and furans, polycyclic aromatic hydrocarbons, and many other compounds present in the environment. It appears that increased oxidative/nitrosative stress is often neglected mechanism by which environmental pollutants affect human health. Oxidation of and oxidative damage to cellular components and biomolecules have been suggested to be involved in the aetiology of several chronic diseases, including cancer, cardiovascular disease, cataracts, age-related macular degeneration, and aging. Several studies have demonstrated that the human body can alleviate oxidative stress using exogenous antioxidants. However, not all dietary antioxidant supplements display protective effects, for example, β-carotene for lung cancer prevention in smokers or tocopherols for photooxidative stress. In this review, we explore the increases in oxidative stress caused by exposure to environmental pollutants and the protective effects of antioxidants. PMID:25140198

  11. Response of antioxidant defences to Zn stress in three duckweed species.

    PubMed

    Uruç Parlak, Kadiriye; Demirezen Yilmaz, Dilek

    2012-11-01

    In the plants, Lemna gibba, Lemna minor and Spirodela polyrrhiza L., the effect of different concentrations of zinc (0.01, 0.05, 0.1, 0.5 and 1.5mgL(-1) Zn) applied for four day was assessed by measuring changes in the chlorophyll, protein, malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and guiacolperoxidase (GPX) activity of the plants. According to results, Zn contents in plants increased with increasing Zn supply levels. The level of photosynthetic pigments and soluble proteins reduced only upon exposure to high Zn concentrations. At the same time, the level of malondialdehyde (MDA) increased with increasing Zn concentration. These results suggested an alleviation of stress that was possibly the result of antioxidants such as catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) as well as guaiacol peroxidise (GPOX), which increased linearly with increasing Zn levels. Cellular antioxidant levels showed an increase suggesting a defensive mechanism to preserve against oxidative stress given rise to by Zn. Besides, the proline amount in L. gibba, L. minor and S. polyrrhiza increased with increasing zinc levels. These conclusions proposed that L. gibba, L. minor and S. polyrrhiza are supplied with an efficient antioxidant mechanism against Zn-induced oxidative stress which saves the plant's photosynthetic machinery from damage. It is concluded that higher zinc levels cause oxidative stress in L. gibba, L. minor and S. polyrrhiza cells and may reason membrane damage through production of ROS and interferes with chlorophyll metabolism. PMID:23009815

  12. Antioxidant defences and haemocyte internalization in Limnoperna fortunei exposed to TiO2 nanoparticles.

    PubMed

    Girardello, Francine; Leite, Camila Custódio; Branco, Catia Santos; Roesch-Ely, Mariana; Fernandes, Andreia Neves; Salvador, Mirian; Henriques, João Antonio Pêgas

    2016-07-01

    TiO2 nanoparticles (TiO2-NP) have been incorporated into a large range of materials for different applications in the last decades and are very likely to appear in wastewater and effluents, eventually reaching the aquatic environment. Therefore, the assessment of the biological impact of TiO2-NP on aquatic ecosystem is of a major concern. The mussels represent a target group for TiO2-NP toxicity, as they are filter feeders and are capable of bioaccumulating toxic compounds. Furthermore, the exotic organism Limnoperna fortunei, golden mussel, is a freshwater bivalve that has been used in biomonitoring environmental conditions. In this work, the TiO2-NP's ability to interact with haemocytes of golden mussel was assessed by transmission electron microscopy. The enzymatic and non-enzymatic antioxidant defenses were evaluated by superoxide dismutase (Sod) and catalase (Cat) activities and protein sulfhydryl content, which were measured after the golden mussel was exposed to TiO2-NP (1, 5, 10 and 50μgmL(-1)). Results demonstrate that TiO2-NP was internalized by cells, causing alterations in haemocytes membrane. Antioxidant activity of Sod and Cat decreased after 2h TiO2-NP exposure. After 4h exposure, the enzymatic antioxidant activity was restored. Notably, the protein sulfhydryl content decreased after 2h to all the TiO2-NP concentrations and no alterations were observed after 4h of TiO2-NP exposure. These results demonstrate the potential of golden mussel as sentinel organism to TiO2-NP exposure. PMID:27152940

  13. Glutamate ameliorates copper-induced oxidative injury by regulating antioxidant defences in fish intestine.

    PubMed

    Jiang, Jun; Wu, Xiao-Yun; Zhou, Xiao-Qiu; Feng, Lin; Liu, Yang; Jiang, Wei-Dan; Wu, Pei; Zhao, Ye

    2016-07-01

    The objective of this study was to determine the protective effect of glutamate (Glu) in Cu-induced oxidative injury in fish intestine in vivo and enterocytes in vitro. The results indicated that exposure to 6 mg/l Cu for 72 h induced the production of reactive oxygen species, thereby increasing protein oxidation and lipid peroxidation in enterocytes of grass carp in vitro. Cells exposed to Cu alone resulted in a significant increase in lactate dehydrogenase release, which is accompanied by depletions of antioxidants, including total superoxide dismutase (T-SOD), glutathione S-transferase (GST), glutathione reductase (GR), anti-superoxide anion (ASA), anti-hydroxy radical (AHR) activities and GSH content. Pre-treatment with Glu remarkably prevented the toxic effects of Cu on the T-SOD, GST, GR, AHR, and ASA activities and GSH content in enterocytes. However, Cu induced an adaptive increase in the activities of catalase and glutathione peroxidase (GPx). Glu supplementation further increased GPx activity in enterocytes. Interestingly, the experiment in vivo showed that Glu pre-supplementation significantly elevated SOD, GPx, GST, GR, ASA and AHR activities, as well as GSH content. Further results showed that pre-treatment with Glu could alleviate Cu-induced oxidative injury by elevating antioxidant enzyme activities through regulating the expression of NF-E2-related nuclear factor 2 (Nrf2) mRNA. Together, these results indicated that Glu could attenuate Cu-induced cellular oxidative damage in fish intestine, likely mediated through Nrf2 signalling pathways regulating mRNA expressions of antioxidant enzyme genes and synthesis of GSH. PMID:27184647

  14. Enzymatic antioxidant system in vascular inflammation and coronary artery disease

    PubMed Central

    Lubrano, Valter; Balzan, Silvana

    2015-01-01

    In biological systems there is a balance between the production and neutralization of reactive oxygen species (ROS). This balance is maintained by the presence of natural antioxidants and antioxidant enzymes such as superoxide dismutase (SOD), catalase and glutathione peroxidase. The enhancement of lipid peroxidation or the decrease of antioxidant protection present in metabolic diseases or bad lifestyle can induce endothelial dysfunction and atherosclerosis. Clinical studies have shown that oxidative stress can increase ROS reducing the formation of antioxidant defences, especially in subjects with coronary artery disease (CAD). Some observation indicated that in the early stages of the disease there is a homeostatic up-regulation of the antioxidant enzyme system in response to increased free radicals to prevent vascular damage. As soon as free radicals get to chronically elevated levels, this compensation ceases. Therefore, SOD and the other enzymes may represent a good therapeutic target against ROS, but they are not useful markers for the diagnosis of CAD. In conclusion antioxidant enzymes are reduced in presence of metabolic disease and CAD. However the existence of genes that promote their enzymatic activity could contribute to create new drugs for the treatment of damage caused by metabolic diseases or lifestyle that increases the plasma ROS levels. PMID:26618108

  15. Effect of isoorientin on intracellular antioxidant defence mechanisms in hepatoma and liver cell lines.

    PubMed

    Yuan, Li; Wang, Jing; Wu, Wanqiang; Liu, Qian; Liu, Xuebo

    2016-07-01

    Isoorientin (ISO) is considered one of the most important flavonoid-like compounds responsible for health benefits, including the prevention of liver damage as well as antioxidant, anti-inflammatory, and anti-nociceptive activities. Our previous study showed that ISO inhibited the proliferation of hepatoma cells through increasing intracellular ROS levels. Interestingly, ISO protects rat liver cells against hydrogen peroxide-induced oxidation stress by decreasing intracellular ROS levels. Why are there different effects of ISO on ROS in different physiological and pathophysiological circumstances? The present study investigated the effect of ISO on mitochondrial respiratory chain complexes and phase II detoxifying enzyme activities in human hepatoblastoma cancer cells (HepG2), buffalo rat liver cells (BRL-3A) and human liver cancer cells (HL-7702). The results showed that intracellular ROS levels and the protein expression of the respiratory chain complexes was significantly (p<0.01) higher in the HepG2 cells than in the BRL-3A and HL-7702 cells. Additionally, ISO notably (p<0.01) increased ROS levels in the HepG2 cells, while no significance was found in the BRL-3A and HL-7702 cells. Furthermore, in the HepG2 cells, the protein expression of the respiratory chain complexes and the phase II detoxifying enzyme activities and GSH content were decreased by ISO (p<0.01), while ISO, in a certain range, enhanced the expression of the protein complexes and the phase II detoxifying enzyme activities and GSH content in BRL-3A and HL-7702 cells. All of these results demonstrated, for the first time, that ISO possesses a notable hepatoprotective effect, which might be mediated through the respiratory chain complexes and phase II detoxifying enzyme activities. PMID:27261613

  16. Methionine-enriched diet decreases hippocampal antioxidant defences and impairs spontaneous behaviour and long-term potentiation in rats.

    PubMed

    Viggiano, Alessandro; Viggiano, Emanuela; Monda, Marcellino; Ingrosso, Diego; Perna, Alessandra F; De Luca, Bruno

    2012-08-30

    Diets high in methionine lead to elevation of plasma homocysteine levels which are possibly linked to neurodegenerative diseases and oxidative stress. In the present study, we investigated the effects of methionine-enriched diet on antioxidant defences, on rat spontaneous behaviour and on the ability to sustain long-term potentiation in the dentate gyrus (DG). Sprague-Dawley rats were fed either a standard laboratory diet or a methionine enriched-diet (1% or 5% methionine in drinking water) for 8 weeks. After the 8 weeks, the animals were tested for spontaneous motor activity and habituation in an open field maze, for anxiety-like behaviour in an elevated plus maze and for the ability to sustain long-term potentiation (LTP) induced in the dentate gyrus under urethane anaesthesia. The brains were then removed and histochemically stained for superoxide dismutase (SOD) activity. Rats fed on 5% methionine significantly reduced total distance travelled during the open field test and exhibited no habituation with respect to the other two groups. Rats fed on 5% methionine also showed a significant increase of the anxiety level. Moreover, in this group, the ability to induce LTP in DG was impaired. SOD activity was significantly increased in the cerebral cortex of the rats fed on 1% and 5% methionine with respect to the control group. In conclusion, 5% methionine in drinking water led to evident impairment of locomotor skills and of synaptic plasticity. SOD activity in the cortex was increased in both the groups fed on 1% and 5% methionine, thus suggesting that metabolic adjustments, triggered by the methionine-enriched diet, are likely mediated by reactive oxygen species. PMID:22781143

  17. AlGaInN laser diode technology and systems for defence and security applications

    NASA Astrophysics Data System (ADS)

    Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lucja; Boćkowski, Mike; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Watson, Scott; Kelly, Antony E.

    2015-05-01

    The latest developments in AlGaInN laser diode technology are reviewed for defence and security applications such as underwater communications. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., ~380nm, to the visible ~530nm, by tuning the indium content of the laser GaInN quantum well. Thus AlGaInN laser diode technology is a key enabler for the development of new disruptive system level applications in displays, telecom, defence and other industries.

  18. A single blueberry (Vaccinium corymbosum) portion does not affect markers of antioxidant defence and oxidative stress in healthy volunteers following cigarette smoking.

    PubMed

    Del Bo', Cristian; Porrini, Marisa; Campolo, Jonica; Parolini, Marina; Lanti, Claudia; Klimis-Zacas, Dorothy; Riso, Patrizia

    2016-03-01

    We previously reported that a portion of blueberries reversed endothelial dysfunction induced by acute cigarette smoking. Since smoking-induced endothelial dysfunction is associated with a condition of oxidative stress, we evaluated whether the observed effect was mediated by modulation of markers of oxidative stress and antioxidant defence. Fourteen out of 16 male healthy smokers previously enrolled, participated in a three-armed randomized controlled study with the following experimental conditions: smoking treatment (one cigarette); blueberry treatment (300g of blueberries) + smoking (one cigarette); control treatment (300ml of water with sugar) + smoking (one cigarette). The cigarette was smoked 100min after blueberry/control/water consumption. Each treatment was separated by 1 week of washout period. Plasma vitamin (C, B12 and folate) and aminothiol concentrations, endogenous [formamidopyrimidine-DNA glycosylase (FPG)-sensitive sites] and oxidatively induced DNA damage (resistance to H2O2-induced DNA damage) in peripheral blood mononuclear cells (PBMCs) were measured at baseline and 20, 60, 90, 120min and 24h after smoking. On the whole, analysis of variance did not show a significant effect of treatment on the modulation of markers of oxidative stress and antioxidant defence but revealed an effect of time for plasma concentrations of vitamin C (P = 0.003), B12 (P < 0.001), folate (P < 0.001), total cysteine (P = 0.007) and cysteine-glycine (P = 0.010) that increased following the three treatments after smoking. No significant effect of treatment was observed for the levels of FPG-sensitive sites (P > 0.05) and H2O2-induced DNA damage (P > 0.05) in PBMCs. In conclusion, the consumption of a single blueberry portion failed to modulate markers of oxidative stress and antioxidant defence investigated in our experimental conditions. Further studies are necessary to elucidate this finding and help clarifying the mechanisms of protection of blueberries against

  19. The Learning Management System at the Defence University: Awareness and Application

    ERIC Educational Resources Information Center

    Juhary, Jowati

    2013-01-01

    This brief paper examines the issues of awareness and application of a Learning Management System (LMS) used at the National Defence University of Malaysia (NDUM), Kuala Lumpur Malaysia. The paper argues that due to the discouraging responses from academics at the university on using the LMS, proactive measures must be taken immediately in order…

  20. Antioxidant measurements.

    PubMed

    Somogyi, Anikó; Rosta, Klára; Pusztai, Péter; Tulassay, Zsolt; Nagy, Géza

    2007-04-01

    Chemical reactions, including oxidation and reduction of molecules, occur in every cell. These reactions can lead to the production of free radicals. Free radicals react with organic substrates such as lipids, proteins, and DNA. Through oxidation free radicals cause damage to these molecules, disturbing their normal function, and may therefore contribute to a variety of diseases. The anti-oxidation system, which consists of enzymatic antioxidants and non-enzymatic antioxidants, defends against oxidative stress. The aim of this review is to summarize general aspects of methods to measure the antioxidant defence system all in one (total antioxidant capacity) and discuss a number of methods which are currently used for detection of antioxidant properties. PMID:17395989

  1. Major bacterial lineages are essentially devoid of CRISPR-Cas viral defence systems.

    PubMed

    Burstein, David; Sun, Christine L; Brown, Christopher T; Sharon, Itai; Anantharaman, Karthik; Probst, Alexander J; Thomas, Brian C; Banfield, Jillian F

    2016-01-01

    Current understanding of microorganism-virus interactions, which shape the evolution and functioning of Earth's ecosystems, is based primarily on cultivated organisms. Here we investigate thousands of viral and microbial genomes recovered using a cultivation-independent approach to study the frequency, variety and taxonomic distribution of viral defence mechanisms. CRISPR-Cas systems that confer microorganisms with immunity to viruses are present in only 10% of 1,724 sampled microorganisms, compared with previous reports of 40% occurrence in bacteria and 81% in archaea. We attribute this large difference to the lack of CRISPR-Cas systems across major bacterial lineages that have no cultivated representatives. We correlate absence of CRISPR-Cas with lack of nucleotide biosynthesis capacity and a symbiotic lifestyle. Restriction systems are well represented in these lineages and might provide both non-specific viral defence and access to nucleotides. PMID:26837824

  2. Major bacterial lineages are essentially devoid of CRISPR-Cas viral defence systems

    PubMed Central

    Burstein, David; Sun, Christine L.; Brown, Christopher T.; Sharon, Itai; Anantharaman, Karthik; Probst, Alexander J.; Thomas, Brian C.; Banfield, Jillian F.

    2016-01-01

    Current understanding of microorganism–virus interactions, which shape the evolution and functioning of Earth's ecosystems, is based primarily on cultivated organisms. Here we investigate thousands of viral and microbial genomes recovered using a cultivation-independent approach to study the frequency, variety and taxonomic distribution of viral defence mechanisms. CRISPR-Cas systems that confer microorganisms with immunity to viruses are present in only 10% of 1,724 sampled microorganisms, compared with previous reports of 40% occurrence in bacteria and 81% in archaea. We attribute this large difference to the lack of CRISPR-Cas systems across major bacterial lineages that have no cultivated representatives. We correlate absence of CRISPR-Cas with lack of nucleotide biosynthesis capacity and a symbiotic lifestyle. Restriction systems are well represented in these lineages and might provide both non-specific viral defence and access to nucleotides. PMID:26837824

  3. Major bacterial lineages are essentially devoid of CRISPR-Cas viral defence systems

    DOE PAGESBeta

    Burstein, David; Sun, Christine L.; Brown, Christopher T.; Sharon, Itai; Anantharaman, Karthik; Probst, Alexander J.; Thomas, Brian C.; Banfield, Jillian F.

    2016-02-03

    Here, current understanding of microorganism–virus interactions, which shape the evolution and functioning of Earth’s ecosystems, is based primarily on cultivated organisms. Here we investigate thousands of viral and microbial genomes recovered using a cultivation independent approach to study the frequency, variety and taxonomic distribution of viral defence mechanisms. CRISPR-Cas systems that confer microorganisms with immunity to viruses are present in only 10% of 1,724 sampled microorganisms, compared with previous reports of 40% occurrence in bacteria and 81% in archaea. We attribute this large difference to the lack of CRISPR-Cas systems across major bacterial lineages that have no cultivated representatives. Wemore » correlate absence of CRISPR-Cas with lack of nucleotide biosynthesis capacity and a symbiotic lifestyle. Restriction systems are well represented in these lineages and might provide both non-specific viral defence and access to nucleotides.« less

  4. MIMIVIRE is a defence system in mimivirus that confers resistance to virophage.

    PubMed

    Levasseur, Anthony; Bekliz, Meriem; Chabrière, Eric; Pontarotti, Pierre; La Scola, Bernard; Raoult, Didier

    2016-03-10

    Since their discovery, giant viruses have revealed several unique features that challenge the conventional definition of a virus, such as their large and complex genomes, their infection by virophages and their presence of transferable short element transpovirons. Here we investigate the sensitivity of mimivirus to virophage infection in a collection of 59 viral strains and demonstrate lineage specificity in the resistance of mimivirus to Zamilon, a unique virophage that can infect lineages B and C of mimivirus but not lineage A. We hypothesized that mimiviruses harbour a defence mechanism resembling the clustered regularly interspaced short palindromic repeat (CRISPR)-Cas system that is widely present in bacteria and archaea. We performed de novo sequencing of 45 new mimivirus strains and searched for sequences specific to Zamilon in a total of 60 mimivirus genomes. We found that lineage A strains are resistant to Zamilon and contain the insertion of a repeated Zamilon sequence within an operon, here named the 'mimivirus virophage resistance element' (MIMIVIRE). Further analyses of the surrounding sequences showed that this locus is reminiscent of a defence mechanism related to the CRISPR-Cas system. Silencing the repeated sequence and the MIMIVIRE genes restores mimivirus susceptibility to Zamilon. The MIMIVIRE proteins possess the typical functions (nuclease and helicase) involved in the degradation of foreign nucleic acids. The viral defence system, MIMIVIRE, represents a nucleic-acid-based immunity against virophage infection. PMID:26934229

  5. Defence strategies adopted by the medicinal plant Coleus forskohlii against supplemental ultraviolet-B radiation: Augmentation of secondary metabolites and antioxidants.

    PubMed

    Takshak, Swabha; Agrawal, S B

    2015-12-01

    Supplementary ultraviolet-B (ambient+3.6  kJ m(-2) day(-1)) induced changes on morphological, physiological, and biochemical characteristics (specifically the defence strategies: UV-B protective compounds and antioxidants) of Coleus forskohlii were investigated under field conditions at 30, 60, and 90 days after transplantation. Levels of secondary metabolites increased under s-UV-B stress; flavonoids and phenolics (primary UV-B screening agents) were recorded to be higher in leaves which are directly exposed to s-UV-B. This was also verified by enhanced activities of phenylpropanoid pathway enzymes: phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), 4-coumarate-CoA ligase (4CL), chalcone-flavanone isomerase (CHI), and dihydroflavonol reductase (DFR). Antioxidants, both enzymatic (ascorbate peroxidase, catalase, glutathione reductase, peroxidase, polyphenol oxidase, and superoxide dismutase) and non-enzymatic (ascorbic acid and α-tocopherol) also increased in the treated organs of the test plant, higher contents being recorded in roots except for ascorbic acid. On the contrary, protein and chlorophyll content (directly implicated in regulating plant growth and development) declined under s-UV-B. These alterations in plant biochemistry led the plant to compromise on its photosynthate allocation towards growth and biomass production as evidenced by a reduction in its height and biomass. The study concludes that s-UV-B is a potent stimulating factor in increasing the concentrations of defense compounds and antioxidants in C. forskohlii to optimize its performance under stress. PMID:26461242

  6. Effect of nutritional antioxidant supplementation on systemic and pulmonary antioxidant status, airway inflammation and lung function in heaves-affected horses.

    PubMed

    Kirschvink, N; Fiévez, L; Bougnet, V; Art, T; Degand, G; Smith, N; Marlin, D; Roberts, C; Harris, P; Lekeux, P

    2002-11-01

    An oxidant/antioxidant imbalance in favour of oxidants has been identified as playing a decisive role in the pathogenesis of chronic inflammatory airway diseases. Nutritional antioxidant supplementation might reduce oxidative damage by enhancement of the antioxidant defence, thereby modulating inflammatory processes. In a placebo-controlled, blind study, it was tested whether a dietary antioxidant supplement administered for 4 weeks would improve lung function and reduce airway inflammation in heaves-affected horses. Eight horses in clinical remission of heaves were investigated at rest and after a standardised exercise test before and after treatment with an antioxidant supplement (consisting of a mixture of natural antioxidants including vitamins E and C and selenium from a variety of sources) or placebo (oatfeed pellets without additive). Pulmonary function and exercise tolerance were monitored; systemic and pulmonary lining fluid uric acid, glutathione and 8-epi-PGF(2alpha) were analysed, and bronchoalveolar lavage (BAL) cytology and inflammatory scoring of the airways were performed. The antioxidant treatment significantly improved exercise tolerance and significantly reduced endoscopic inflammatory score. Plasma uric acid concentrations were significantly reduced, suggesting downregulation of the xanthine-dehydrogenase and xanthine-oxydase pathway. Haemolysate glutathione showed a nonsignificant trend to increase, while plasma 8-epi-PGF(2alpha) remained unchanged. Pulmonary markers and BAL cytology were not significantly affected by antioxidant supplementation. The present study suggests that the antioxidant supplement tested modulated oxidant/antioxidant balance and airway inflammation of heaves-affected horses. PMID:12455842

  7. Effect of vitamin C supplements on antioxidant defence and stress proteins in human lymphocytes and skeletal muscle

    PubMed Central

    Khassaf, M; McArdle, A; Esanu, C; Vasilaki, A; McArdle, F; Griffiths, R D; Brodie, D A; Jackson, M J

    2003-01-01

    Oxidative stress induces adaptations in the expression of protective enzymes and heat shock proteins (HSPs) in a variety of tissues. We have examined the possibility that supplementation of subjects with the nutritional antioxidant, vitamin C, influences the ability of lymphocytes to express protective enzymes and HSPs following exposure to an exogenous oxidant and the response of skeletal muscle to the physiological oxidative stress that occurs during exercise in vivo. Our hypothesis was that an elevation of tissue vitamin C content would reduce oxidant-induced expression of protective enzymes and HSP content. Lymphocytes from non-supplemented subjects responded to hydrogen peroxide with increased activity of superoxide dismutase (SOD) and catalase, and HSP60 and HSP70 content over 48 h. Vitamin C supplementation at a dose of 500 mg day−1 for 8 weeks was found to increase the serum vitamin C concentration by ∼50 %. Lymphocytes from vitamin C-supplemented subjects had increased baseline SOD and catalase activities and an elevated HSP60 content. The SOD and catalase activities and the HSP60 and HSP70 content of lymphocytes from supplemented subjects did not increase significantly in response to hydrogen peroxide. In non-supplemented subjects, a single period of cycle ergometry was found to significantly increase the HSP70 content of the vastus lateralis. Following vitamin C supplementation, the HSP70 content of the muscle was increased at baseline with no further increase following exercise. We conclude that, in vitamin C-supplemented subjects, adaptive responses to oxidants are attenuated, but that this may reflect an increased baseline expression of potential protective systems against oxidative stress (SOD, catalase and HSPs). PMID:12692182

  8. Antioxidant defence-related genetic variants are not associated with higher risk of secondary thyroid cancer after treatment of malignancy in childhood or adolescence

    PubMed Central

    Vodusek, Ana Lina; Goricar, Katja; Gazic, Barbara; Dolzan, Vita

    2016-01-01

    Background Thyroid cancer is one of the most common secondary cancers after treatment of malignancy in childhood or adolescence. Thyroid gland is very sensitive to the carcinogenic effect of ionizing radiation, especially in children. Imbalance between pro- and anti-oxidant factors may play a role in thyroid carcinogenesis. Our study aimed to assess the relationship between genetic variability of antioxidant defence-related genes and the risk of secondary thyroid cancer after treatment of malignancy in childhood or adolescence. Patients and methods In a retrospective study, we compared patients with childhood or adolescence primary malignancy between 1960 and 2006 that developed a secondary thyroid cancer (cases) with patients (controls), with the same primary malignancy but did not develop any secondary cancer. They were matched for age, gender, primary diagnosis and treatment (especially radiotherapy) of primary malignancy. They were all genotyped for SOD2 p.Ala16Val, CAT c.-262C>T, GPX1 p.Pro200Leu, GSTP1 p.Ile105Val, GSTP1 p.Ala114Val and GSTM1 and GSTT1 deletions. The influence of polymorphisms on occurrence of secondary cancer was examined by McNemar test and Cox proportional hazards model. Results Between 1960 and 2006 a total of 2641 patients were diagnosed with primary malignancy before the age of 21 years in Slovenia. Among them 155 developed a secondary cancer, 28 of which were secondary thyroid cancers. No significant differences in the genotype frequency distribution were observed between cases and controls. Additionally we observed no significant influence of investigated polymorphisms on time to the development of secondary thyroid cancer. Conclusions We observed no association of polymorphisms in antioxidant genes with the risk for secondary thyroid cancer after treatment of malignancy in childhood or adolescence. However, thyroid cancer is one of the most common secondary cancers in patients treated for malignancy in childhood or adolescence and

  9. AlGaInN laser diode technology and systems for defence and security applications

    NASA Astrophysics Data System (ADS)

    Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lujca; Boćkowski, Mike; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Watson, Scott; Kelly, Antony E.

    2015-10-01

    AlGaInN laser diodes is an emerging technology for defence and security applications such as underwater communications and sensing, atomic clocks and quantum information. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., ~380nm, to the visible ~530nm, by tuning the indium content of the laser GaInN quantum well. Thus AlGaInN laser diode technology is a key enabler for the development of new disruptive system level applications in displays, telecom, defence and other industries. Ridge waveguide laser diodes are fabricated to achieve single mode operation with optical powers up to 100mW with the 400-440nm wavelength range with high reliability. Visible free-space and underwater communication at frequencies up to 2.5GHz is reported using a directly modulated 422nm GaN laser diode. Low defectivity and highly uniform GaN substrates allow arrays and bars to be fabricated. High power operation operation of AlGaInN laser bars with up to 20 emitters have been demonstrated at optical powers up to 4W in a CS package with common contact configuration. An alternative package configuration for AlGaInN laser arrays allows for each individual laser to be individually addressable allowing complex free-space or optical fibre system integration with a very small form-factor.

  10. Effects of Inulin Supplementation in Low- or High-Fat Diets on Reproductive Performance of Sows and Antioxidant Defence Capacity in Sows and Offspring.

    PubMed

    Wang, Y S; Zhou, P; Liu, H; Li, S; Zhao, Y; Deng, K; Cao, D D; Che, L Q; Fang, Z F; Xu, S Y; Lin, Y; Feng, B; Li, J; Wu, D

    2016-08-01

    This experiment was conducted to investigate the effects of inulin supplementation in low- or high-fat diets on both the reproductive performance of sow and the antioxidant defence capacity in sows and offspring. Sixty Landrace × Yorkshire sows were randomly allocated to four treatments with low-fat diet (L), low-fat diet containing 1.5% inulin (LI), high-fat diet (H) and high-fat diet containing 1.5% inulin (HI). Inulin-rich diets lowered the within-litter birth weight coefficient of variation (CV, p = 0.05) of piglets, increased the proportion of piglets weighing 1.0-1.5 kg at farrowing (p < 0.01), reduced the loss of body weight (BW) and backfat thickness (BF) during lactation (p < 0.05) and decreased the duration of farrowing as well as improved sow constipation (p < 0.05). Sows fed fat-rich diets gained more BW during gestation (p < 0.01), farrowed a greater number of total (+1.65 pigs, p < 0.05) and alive (+1.52 pigs p < 0.05) piglets and had a heavier (+2.06 kg, p < 0.05) litter weight at birth as well as a decreased weaning-to-oestrous interval (WEI, p < 0.01) compared with sows fed low-fat diets. However, it is worth noting that the H diet significantly decreased the serum activities of superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) and increased the serum malondialdehyde (MDA) levels in sows and piglets (p < 0.05). In contrast, HI diet enhanced the activities of T-SOD and GSH-Px and decreased the serum MDA concentrations (p < 0.05) in sows and piglets. In summary, the fat-rich diets fed to sows during gestation had beneficial effects on reproductive performance, but aggravated the oxidative stress in sow and piglets. Inulin-rich diets fed to sow during gestation had beneficial effects on within-litter uniformity of piglet birthweight and enhanced the antioxidant defence capacity of sows and piglets. PMID:27174736

  11. Arabidopsis AZI1 family proteins mediate signal mobilization for systemic defence priming.

    PubMed

    Cecchini, Nicolás M; Steffes, Kevin; Schläppi, Michael R; Gifford, Andrew N; Greenberg, Jean T

    2015-01-01

    Priming is a major mechanism behind the immunological 'memory' observed during two key plant systemic defences: systemic acquired resistance (SAR) and induced systemic resistance (ISR). Lipid-derived azelaic acid (AZA) is a mobile priming signal. Here, we show that the lipid transfer protein (LTP)-like AZI1 and its closest paralog EARLI1 are necessary for SAR, ISR and the systemic movement and uptake of AZA in Arabidopsis. Imaging and fractionation studies indicate that AZI1 and EARLI1 localize to expected places for lipid exchange/movement to occur. These are the ER/plasmodesmata, chloroplast outer envelopes and membrane contact sites between them. Furthermore, these LTP-like proteins form complexes and act at the site of SAR establishment. The plastid targeting of AZI1 and AZI1 paralogs occurs through a mechanism that may enable/facilitate their roles in signal mobilization. PMID:26203923

  12. Developments in aspects of ecological phytochemistry: the role of cis-jasmone in inducible defence systems in plants.

    PubMed

    Pickett, John A; Birkett, Michael A; Bruce, Toby J A; Chamberlain, Keith; Gordon-Weeks, Ruth; Matthes, Michaela C; Napier, Johnathan A; Smart, Lesley E; Woodcock, Christine M

    2007-01-01

    The challenges and opportunities for protecting agricultural production of food and other materials will be met through exploiting the induction of defence pathways in plants to control pests, diseases and weeds. These approaches will involve processes that can be activated by application of natural products, patented in terms of this use, to "switch on" defence pathways. Already, a number of secondary metabolite defence compounds are known for which the pathways are conveniently clustered genomically, e.g. the benzoxazinoids (hydroxamic acids) and the avenacins. For the former, it is shown that the small molecular weight lipophilic activator cis-jasmone can induce production of these compounds and certain genes within the pathway. Numerous groups around the world work on inducible defence systems. The science is rapidly expanding and involves studying the interacting components of defence pathways and the switching mechanisms activated by small molecular weight lipophilic compounds. Examples are described of how plant breeding can exploit these systems and how heterologous gene expression will eventually give rise to a new range of GM crops for food and energy, without the need for external application of synthetic pesticides. PMID:18023830

  13. The organophosphate insecticide Coumaphos induces oxidative stress and increases antioxidant and detoxification defences in the green macroalgae Ulva pertusa.

    PubMed

    Schweikert, Katja; Burritt, David J

    2012-10-15

    It is well established that many pesticides used in the farming and horticultural industries are harmful to not only the target species they were developed for, but also other organisms. Organophosphates were introduced as a replacement for the organochlorines and are generally considered non-toxic to plants and algae. This study investigated the impact of Coumaphos, a commonly used organophosphate, on the estuarine macrophyte Ulva pertusa. In a seven-day experiment U. pertusa cultures were exposed to four environmentally relevant concentrations of Coumaphos (0.01 mg/L, 0.05 mg/L, 0.1mg/L, 0.5 mg/L), well below the aqueous solubility maximum of the insecticide. The impact of Coumaphos was determined at a cellular level by assessing oxidative damage in the form of protein carbonyl and lipid hydroperoxide levels. Furthermore, non-enzymatic antioxidant levels and changes in the levels of enzymatic antioxidants and the enzyme GST were measured. Concentrations of Coumaphos above 0.01 mg/L caused rapid increases in the levels of protein carbonyls and lipid hydroperoxides peaking after 2-3 days of exposure, followed by a rapid decline in both markers of oxidative stress. Glutathione levels and the activities SOD, CAT, GR, APOX and GST all increased in response to the higher concentrations of Coumaphos tested and remained elevated for the duration of the experiment. These results demonstrate that environmentally relevant levels of the insecticide Coumaphos can cause oxidative damage and increase the antioxidant scavenging capacity, and GST activity in U. pertusa. This could potentially alter resource allocation within this alga, impacting algal growth and development, with possible indirect ecological consequences. PMID:22728208

  14. [Characteristics of amaranth oil effect on the antioxidant system of the liver and blood in mice with malignant lymphoma growth].

    PubMed

    Ielisieieva, O P; Kamins'kyĭ, D V; Cherkas, A P; Ambarova, L I; Vyshemyrs'ka, L D; Dzhura, O R; Semen, Kh O; Makhotina, O O

    2006-01-01

    The dynamics of functioning of the lipid peroxidation <--> antioxidant activity system was studied during the tumor growth in the blood, liver and NK/Ly cells in mice fed with amaranth oil (100 microL/100 g, once a day, 10 days before inoculation and during tumor growth for 14 days). Different effects on antioxidant activity were demonstrated. Activity of the antioxidant enzymes in hepatocytes of mice fed with amaranth oil was aimed at maintenance of antioxidant defence in tumor growth. This effect was achieved owing to the marked increase in superoxide dismutase, preserved catalase and decreased glutathione peroxidase activities with simultaneous increase in hydroperoxides levels and decrease of thiobarbituric acid-reactive subspecies. Changes observed in NK/Ly lymphoma cells were directed to providing a higher prooxidant activity than in the liver cells. Modification of antioxidant activity induced by amaranth oil can maintain oxygen homeostasis, morphofunctional state and inhibit tumor cells proliferation. PMID:17147274

  15. Vampires, Pasteur and reactive oxygen species. Is the switch from aerobic to anaerobic metabolism a preventive antioxidant defence in blood-feeding parasites?

    PubMed

    Oliveira, Pedro L; Oliveira, Marcus F

    2002-08-14

    Several species of parasites show a reduction of their respiratory activity along their developmental cycles after they start to feed on vertebrate blood, relying on anaerobic degradation of carbohydrates to achieve their energy requirements. Usually, these parasites choose not to breathe despite of living in an environment of high oxygen availability such as vertebrate blood. Absence of the 'Pasteur effect' in most of these parasites has been well documented. Interestingly, together with the switch from aerobic to anaerobic metabolism in these parasites, there is clear evidence pointing to an increase in their antioxidant defences. As the respiratory chain in mitochondria is a major site of production of reactive oxygen species (ROS), we propose here that the arrest of respiration constitutes an adaptation to avoid the toxic effects of ROS. This situation would be especially critical for blood-feeding parasites because ROS produced in mitochondria would interact with pro-oxidant products of blood digestion, such as haem and/or iron, and increase the oxidative damage to the parasite's cells. PMID:12163151

  16. Functional proteomics of neurokinin B in the placenta indicates a novel role in regulating cytotrophoblast antioxidant defences.

    PubMed

    Sawicki, Grzegorz; Dakour, Jamal; Morrish, Donald W

    2003-10-01

    Neurokinin B (NKB) has recently been demonstrated to be secreted from the placenta in abnormally high amounts in preeclampsia (PE) and to cause hypertension in rats, suggesting it may be a mediator of some pathophysiological features of PE. It is also known that NKB receptors exist in the placenta. To determine the effect of high levels of NKB on the placenta, we have performed proteomics on five separate preparations of cultured purified human term cytotrophoblast cells. The results showed a statistically significant decrease in 20 proteins, of which five were unknown proteins. Proteins important in antioxidant defenses that decreased were thioredoxin, cyclophilin A, cytokeratin 1, and peroxiredoxin 5. Two proteins that inhibit intravascular anticoagulation, cytokeratin 1 and annexin 11 were also decreased. Pathways involving pro-inflammatory cytokine activation of NF-kappa B are opposed by Raf kinase inhibitor protein, which was also decreased. Cofilin 1, a protein involved in defense against bacteria, was also decreased. Among other proteins that were suppressed by NKB were proteasome proteins, desmoplakin, and calgizzarin. Western blots confirmed the decrease in cytokeratin 1 and cyclophilin A protein after NKB exposure. In PE, there is reduced antioxidant activity and increased intravascular coagulation. The findings that high levels of NKB, similar to those observed in PE, can impair these two classes of activity support the hypothesis that high NKB levels may contribute to the pathogenesis of PE. PMID:14625867

  17. Role of antioxidant enzymatic defences against oxidative stress H(2)O(2) and the acquisition of oxidative tolerance in Candida albicans.

    PubMed

    González-Párraga, Pilar; Hernández, José A; Argüelles, Juan Carlos

    2003-10-30

    In Candida albicans, trehalose plays an essential role as a protector of cell integrity against oxidative challenge. A double homozygous mutant, tps1/tps1, deficient in trehalose synthesis, displayed severe cell mortality when exposed to high H(2)O(2) concentrations, compared with its congenic parental (CAI-4) strain (Alvarez-Peral et al., 2002). We have examined the putative role of a set of well-known antioxidant enzymes as components of the defence mechanism against oxidative challenges. When exposed to mild non-lethal oxidative treatment (0.5 mM H(2)O(2)), a significant induction of catalase, glutathione reductase (GR), and Cu,Zn-superoxide dismutase (SOD) was recorded in tps1/tps1 exponential cultures. However, in CAI-4 cells, subjected to the same conditions, there was only a clear activation of catalase, Mn-SOD and Cu,Zn-SOD activities. The degree of activation was always much more pronounced in the trehalose-deficient mutant than in its wild-type counterpart, except for Mn-SOD activity. After exposure to severe oxidative stress (50 mM H(2)O(2)) only GR and catalase activities increased in tps1/tps1 cultures, whereas in CAI-4 cells GR but not catalase was induced. In both cell strains, 50 mM H(2)O(2) caused inhibition of the Mn- and Cu,Zn-SOD isozymes, this inhibition being more pronounced in tps1/tps1 cells. C. albicans is able to acquire adaptive oxidative tolerance by pretreatment with a low non-stressing concentration of H(2)O(2) before exposure to a drastic oxidative challenge. When these antioxidant activities were measured during the adaptive response, a greater degree of enzymatic antioxidant induction was consistently observed in the tps1/tps1 mutant with respect to the CAI-4 strain. Together with a higher intrinsic sensitivity of tps1/tps1 cells, we suggest that this unexpected increase might be explained in terms of a compensatory mechanism to overcome the lack of endogenous trehalose upon drastic oxidative exposure, although this induction was

  18. TORC1 Inhibition by Rapamycin Promotes Antioxidant Defences in a Drosophila Model of Friedreich’s Ataxia

    PubMed Central

    Calap-Quintana, Pablo; Soriano, Sirena; Llorens, José Vicente; Al-Ramahi, Ismael; Botas, Juan; Moltó, María Dolores; Martínez-Sebastián, María José

    2015-01-01

    Friedreich’s ataxia (FRDA), the most common inherited ataxia in the Caucasian population, is a multisystemic disease caused by a significant decrease in the frataxin level. To identify genes capable of modifying the severity of the symptoms of frataxin depletion, we performed a candidate genetic screen in a Drosophila RNAi-based model of FRDA. We found that genetic reduction in TOR Complex 1 (TORC1) signalling improves the impaired motor performance phenotype of FRDA model flies. Pharmacologic inhibition of TORC1 signalling by rapamycin also restored this phenotype and increased the lifespan and ATP levels. Furthermore, rapamycin reduced the altered levels of malondialdehyde + 4-hydroxyalkenals and total glutathione of the model flies. The rapamycin-mediated protection against oxidative stress is due in part to an increase in the transcription of antioxidant genes mediated by cap-n-collar (Drosophila ortholog of Nrf2). Our results suggest that autophagy is indeed necessary for the protective effect of rapamycin in hyperoxia. Rapamycin increased the survival and aconitase activity of model flies subjected to high oxidative insult, and this improvement was abolished by the autophagy inhibitor 3-methyladenine. These results point to the TORC1 pathway as a new potential therapeutic target for FRDA and as a guide to finding new promising molecules for disease treatment. PMID:26158631

  19. The transcriptional coregulator PGC-1β controls mitochondrial function and anti-oxidant defence in skeletal muscles.

    PubMed

    Gali Ramamoorthy, Thanuja; Laverny, Gilles; Schlagowski, Anna-Isabel; Zoll, Joffrey; Messaddeq, Nadia; Bornert, Jean-Marc; Panza, Salvatore; Ferry, Arnaud; Geny, Bernard; Metzger, Daniel

    2015-01-01

    The transcriptional coregulators PGC-1α and PGC-1β modulate the expression of numerous partially overlapping genes involved in mitochondrial biogenesis and energetic metabolism. The physiological role of PGC-1β is poorly understood in skeletal muscle, a tissue of high mitochondrial content to produce ATP levels required for sustained contractions. Here we determine the physiological role of PGC-1β in skeletal muscle using mice, in which PGC-1β is selectively ablated in skeletal myofibres at adulthood (PGC-1β((i)skm-/-) mice). We show that myofibre myosin heavy chain composition and mitochondrial number, muscle strength and glucose homeostasis are unaffected in PGC-1β((i)skm-/-) mice. However, decreased expression of genes controlling mitochondrial protein import, translational machinery and energy metabolism in PGC-1β((i)skm-/-) muscles leads to mitochondrial structural and functional abnormalities, impaired muscle oxidative capacity and reduced exercise performance. Moreover, enhanced free-radical leak and reduced expression of the mitochondrial anti-oxidant enzyme Sod2 increase muscle oxidative stress. PGC-1β is therefore instrumental for skeletal muscles to cope with high energetic demands. PMID:26674215

  20. The transcriptional coregulator PGC-1β controls mitochondrial function and anti-oxidant defence in skeletal muscles

    PubMed Central

    Gali Ramamoorthy, Thanuja; Laverny, Gilles; Schlagowski, Anna-Isabel; Zoll, Joffrey; Messaddeq, Nadia; Bornert, Jean-Marc; Panza, Salvatore; Ferry, Arnaud; Geny, Bernard; Metzger, Daniel

    2015-01-01

    The transcriptional coregulators PGC-1α and PGC-1β modulate the expression of numerous partially overlapping genes involved in mitochondrial biogenesis and energetic metabolism. The physiological role of PGC-1β is poorly understood in skeletal muscle, a tissue of high mitochondrial content to produce ATP levels required for sustained contractions. Here we determine the physiological role of PGC-1β in skeletal muscle using mice, in which PGC-1β is selectively ablated in skeletal myofibres at adulthood (PGC-1β(i)skm−/− mice). We show that myofibre myosin heavy chain composition and mitochondrial number, muscle strength and glucose homeostasis are unaffected in PGC-1β(i)skm−/− mice. However, decreased expression of genes controlling mitochondrial protein import, translational machinery and energy metabolism in PGC-1β(i)skm−/− muscles leads to mitochondrial structural and functional abnormalities, impaired muscle oxidative capacity and reduced exercise performance. Moreover, enhanced free-radical leak and reduced expression of the mitochondrial anti-oxidant enzyme Sod2 increase muscle oxidative stress. PGC-1β is therefore instrumental for skeletal muscles to cope with high energetic demands. PMID:26674215

  1. Integrating resource defence theory with a neural nonapeptide pathway to explain territory-based mating systems

    PubMed Central

    2015-01-01

    The ultimate-level factors that drive the evolution of mating systems have been well studied, but an evolutionarily conserved neural mechanism involved in shaping behaviour and social organization across species has remained elusive. Here, we review studies that have investigated the role of neural arginine vasopressin (AVP), vasotocin (AVT), and their receptor V1a in mediating variation in territorial behaviour. First, we discuss how aggression and territoriality are a function of population density in an inverted-U relationship according to resource defence theory, and how territoriality influences some mating systems. Next, we find that neural AVP, AVT, and V1a expression, especially in one particular neural circuit involving the lateral septum of the forebrain, are associated with territorial behaviour in males of diverse species, most likely due to their role in enhancing social cognition. Then we review studies that examined multiple species and find that neural AVP, AVT, and V1a expression is associated with territory size in mammals and fishes. Because territoriality plays an important role in shaping mating systems in many species, we present the idea that neural AVP, AVT, and V1a expression that is selected to mediate territory size may also influence the evolution of different mating systems. Future research that interprets proximate-level neuro-molecular mechanisms in the context of ultimate-level ecological theory may provide deep insight into the brain-behaviour relationships that underlie the diversity of social organization and mating systems seen across the animal kingdom. PMID:26813803

  2. Integrating resource defence theory with a neural nonapeptide pathway to explain territory-based mating systems.

    PubMed

    Oldfield, Ronald G; Harris, Rayna M; Hofmann, Hans A

    2015-01-01

    The ultimate-level factors that drive the evolution of mating systems have been well studied, but an evolutionarily conserved neural mechanism involved in shaping behaviour and social organization across species has remained elusive. Here, we review studies that have investigated the role of neural arginine vasopressin (AVP), vasotocin (AVT), and their receptor V1a in mediating variation in territorial behaviour. First, we discuss how aggression and territoriality are a function of population density in an inverted-U relationship according to resource defence theory, and how territoriality influences some mating systems. Next, we find that neural AVP, AVT, and V1a expression, especially in one particular neural circuit involving the lateral septum of the forebrain, are associated with territorial behaviour in males of diverse species, most likely due to their role in enhancing social cognition. Then we review studies that examined multiple species and find that neural AVP, AVT, and V1a expression is associated with territory size in mammals and fishes. Because territoriality plays an important role in shaping mating systems in many species, we present the idea that neural AVP, AVT, and V1a expression that is selected to mediate territory size may also influence the evolution of different mating systems. Future research that interprets proximate-level neuro-molecular mechanisms in the context of ultimate-level ecological theory may provide deep insight into the brain-behaviour relationships that underlie the diversity of social organization and mating systems seen across the animal kingdom. PMID:26813803

  3. Stress, antioxidant defence and mucosal immune responses of the large yellow croaker Pseudosciaena crocea challenged with Cryptocaryon irritans.

    PubMed

    Yin, Fei; Gong, Hui; Ke, Qiaozhen; Li, Anxing

    2015-11-01

    To clarify the effects of a Cryptocaryon irritans infection on the stress, antioxidant and mucosal immune response of the large yellow croaker Pseudosciaena crocea, this study utilized C. irritans at dose of 12,000 (group I); 24,000 (group II); and 36,000 (group III) theronts/fish to infect large yellow croaker weighing 100 ± 10 g. The food intake, survival and relative infection intensity (RII); levels of reactive oxygen species (ROS), malondialdehyde (MDA) and vitamin C (VC), activities of super oxide dismutase (SOD) and catalase (CAT) in liver; variation patterns of lysozyme (LZM), alkaline phosphatase (AKP), complement component 3 (C3) and immunoglobulin M (IgM) levels in the body surface mucus at different time points after infection were compared. These results showed that with the increase of the infection dose and the passage of time, the food intake and survival of the fish gradually decreased. The final survival of the control group (0 theronts/fish), group I, group II, and group III was 100, 100, 96.67 ± 5.77, and 48.33 ± 7.64. Group I, II, and III stopped feeding respectively on the third, third and second days after infection. RII increased significantly with increased infection dose. The RII of the control group, group I, group II, and group III was 0, 0.73 ± 0.06, 1.30 ± 0.26, and 1.84 ± 0.02. With the infection dose increased, ROS contents showed an overall upward trend; MDA contents of the group I, group II and group III did not show significant changes at any timepoint compared with the control group; Activities of SOD and CAT and the overall VC levels in the liver of P. crocea dropped; LZM activity showed an overall upward trend; AKP activity increased first then dropped at each timepoint with its highest level appearing at group II; Complement C3 and IgM levels in body surface mucus were significantly increased. In conclusion, P. crocea has a strong ability to resist oxidative stress caused by the infection of C. irritans. The body surface

  4. Characteristics of Antioxidant Systems of Yellow Fraction of Red Deer's (Cervus elaphus L.) Semen During the Rutting Period.

    PubMed

    Koziorowska-Gilun, M; Szurnicka, M; Dziekonska, A; Kordan, W; Giżejewski, Z; Filipowicz, K

    2016-04-01

    The objective of this study was to make the preliminary characterization of the antioxidant defence systems of the yellow fraction (YF) of red deer's (Cervus elaphus L.) semen during the rutting period. The semen was collected using artificial vagina (AV). The studies included spectrophotometric determination of antioxidant enzymes activities such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). We also analysed the contents of low-molecular antioxidants such as L-glutathione (GSH + GSSG), L-ascorbate (ASC) and total antioxidant status (TAS). Additionally, the samples were subjected to PAGE and stained for SOD and GPx activities. It was demonstrated that the yellow fraction exhibited activities of SOD and GPx, with the highest activities in September and October. CAT activity was not detected. Staining for the SOD and GPx activities confirmed three protein bands with SOD activity and one protein band with GPx activity. The content of GSH + GSSG was similar in trials dating from October to December contrary to the content of ASC which was high in samples from September and October. The stable rate of TAS was observed during the whole rutting period. The results of this study showed that the YF of red deer semen is equipped with basic battery of antioxidant enzymes comprising SOD and GPx, with the supporting role of GSH + GSSG and ASC. Moreover, the samples obtained at the peak of the rutting period occurring from September to October had the highest enzymatic activity in comparison with remaining months of the rutting period, which contributed to the high quality of the semen by preventing it from the formation of oxidative stress during the short period of intense sexual activity of male red deer. The better understanding of the mechanisms of antioxidant defence systems in the YF of deer's semen may contribute to the potential use of this fraction in technology of wild ruminant semen preservation. PMID:26854018

  5. Changes in the alternative electron sinks and antioxidant defence in chloroplasts of the extreme halophyte Eutrema parvulum (Thellungiella parvula) under salinity

    PubMed Central

    Uzilday, Baris; Ozgur, Rengin; Sekmen, A. Hediye; Yildiztugay, Evren; Turkan, Ismail

    2015-01-01

    Background and Aims Eutrema parvulum (synonym, Thellungiella parvula) is an extreme halophyte that thrives in high salt concentrations (100–150 mm) and is closely related to Arabidopsis thaliana. The main aim of this study was to determine how E. parvulum uses reactive oxygen species (ROS) production, antioxidant systems and redox regulation of the electron transport system in chloroplasts to tolerate salinity. Methods Plants of E. parvulum were grown for 30 d and then treated with either 50, 200 or 300 mm NaCl. Physiological parameters including growth and water relationships were measured. Activities of antioxidant enzymes were determined in whole leaves and chloroplasts. In addition, expressions of chloroplastic redox components such as ferrodoxin thioredoxin reductases (FTR), NADPH thioredoxin reductases (NTRC), thioredoxins (TRXs) and peroxiredoxins (PRXs), as well as genes encoding enzymes of the water–water cycle and proline biosynthesis were measured. Key Results Salt treatment affected water relationships negatively and the accumulation of proline was increased by salinity. E. parvulum was able to tolerate 300 mm NaCl over long periods, as evidenced by H2O2 content and lipid peroxidation. While Ca2+ and K+ concentrations were decreased by salinity, Na+ and Cl– concentrations increased. Efficient induction of activities and expressions of water–water cycle enzymes might prevent accumulation of excess ROS in chloroplasts and therefore protect the photosynthetic machinery in E. parvulum. The redox homeostasis in chloroplasts might be achieved by efficient induction of expressions of redox regulatory enzymes such as FTR, NTRC, TRXs and PRXs under salinity. Conclusions E. parvulum was able to adapt to osmotic stress by an efficient osmotic adjustment mechanism involving proline and was able to regulate its ion homeostasis. In addition, efficient induction of water–water cycle enzymes and other redox regulatory components such as TRXs and PRXs in

  6. Cellular mechanisms of redox cell signalling: role of cysteine modification in controlling antioxidant defences in response to electrophilic lipid oxidation products.

    PubMed Central

    Levonen, Anna-Liisa; Landar, Aimee; Ramachandran, Anup; Ceaser, Erin K; Dickinson, Dale A; Zanoni, Giuseppe; Morrow, Jason D; Darley-Usmar, Victor M

    2004-01-01

    The molecular mechanisms through which oxidized lipids and their electrophilic decomposition products mediate redox cell signalling is not well understood and may involve direct modification of signal-transduction proteins or the secondary production of reactive oxygen or nitrogen species in the cell. Critical in the adaptation of cells to oxidative stress, including exposure to subtoxic concentrations of oxidized lipids, is the transcriptional regulation of antioxidant enzymes, many of which are controlled by antioxidant-responsive elements (AREs), also known as electrophile-responsive elements. The central regulator of the ARE response is the transcription factor Nrf2 (NF-E2-related factor 2), which on stimulation dissociates from its cytoplasmic inhibitor Keap1, translocates to the nucleus and transactivates ARE-dependent genes. We hypothesized that electrophilic lipids are capable of activating ARE through thiol modification of Keap1 and we have tested this concept in an intact cell system using induction of glutathione synthesis by the cyclopentenone prostaglandin, 15-deoxy-Delta12,14-prostaglandin J2. On exposure to 15-deoxy-Delta12,14-prostaglandin J2, the dissociation of Nrf2 from Keap1 occurred and this was dependent on the modification of thiols in Keap1. This mechanism appears to encompass other electrophilic lipids, since 15-A(2t)-isoprostane and the lipid aldehyde 4-hydroxynonenal were also shown to modify Keap1 and activate ARE. We propose that activation of ARE through this mechanism will have a major impact on inflammatory situations such as atherosclerosis, in which both enzymic as well as non-enzymic formation of electrophilic lipid oxidation products are increased. PMID:14616092

  7. Systemic resistance and lipoxygenase-related defence response induced in tomato by Pseudomonas putida strain BTP1

    PubMed Central

    Akram, Adam; Ongena, Marc; Duby, Francéline; Dommes, Jacques; Thonart, Philippe

    2008-01-01

    Background Previous studies showed the ability of Pseudomonas putida strain BTP1 to promote induced systemic resistance (ISR) in different host plants. Since ISR is long-lasting and not conducive for development of resistance of the targeted pathogen, this phenomenon can take part of disease control strategies. However, in spite of the numerous examples of ISR induced by PGPR in plants, only a few biochemical studies have associated the protective effect with specific host metabolic changes. Results In this study, we showed the protective effect of this bacterium in tomato against Botrytis cinerea. Following treatment by P. putida BTP1, analyses of acid-hydrolyzed leaf extracts showed an accumulation of antifungal material after pathogen infection. The fungitoxic compounds thus mainly accumulate as conjugates from which active aglycones may be liberated through the activity of hydrolytic enzymes. These results suggest that strain BTP1 can elicit systemic phytoalexin accumulation in tomato as one defence mechanism. On another hand, we have shown that key enzymes of the lipoxygenase pathway are stimulated in plants treated with the bacteria as compared with control plants. Interestingly, this stimulation is observed only after pathogen challenge in agreement with the priming concept almost invariably associated with the ISR phenomenon. Conclusion Through the demonstration of phytoalexin accumulation and LOX pathway stimulation in tomato, this work provides new insights into the diversity of defence mechanisms that are inducible by non-pathogenic bacteria in the context of ISR. PMID:19000301

  8. Enhancement of Cellular Antioxidant-Defence Preserves Diastolic Dysfunction via Regulation of Both Diastolic Zn2+ and Ca2+ and Prevention of RyR2-Leak in Hyperglycemic Cardiomyocytes

    PubMed Central

    Tuncay, Erkan; Okatan, Esma N.; Toy, Aysegul; Turan, Belma

    2014-01-01

    We examined whether cellular antioxidant-defence enhancement preserves diastolic dysfunction via regulation of both diastolic intracellular free Zn2+ and Ca2+ levels ([Zn2+]i and [Ca2+]i) levels N-acetyl cysteine (NAC) treatment (4 weeks) of diabetic rats preserved altered cellular redox state and also prevented diabetes-induced tissue damage and diastolic dysfunction with marked normalizations in the resting [Zn2+]i and [Ca2+]i. The kinetic parameters of transient changes in Zn2+ and Ca2+ under electrical stimulation and the spatiotemporal properties of Zn2+ and Ca2+ sparks in resting cells are found to be normal in the treated diabetic group. Biochemical analysis demonstrated that the NAC treatment also antagonized hyperphosphorylation of cardiac ryanodine receptors (RyR2) and significantly restored depleted protein levels of both RyR2 and calstabin2. Incubation of cardiomyocytes with 10 µM ZnCl2 exerted hyperphosphorylation in RyR2 as well as higher phosphorphorylations in both PKA and CaMKII in a concentration-dependent manner, similar to hyperglycemia. Our present data also showed that a subcellular oxidative stress marker, NF-κB, can be activated if the cells are exposed directly to Zn2+. We thus for the first time report that an enhancement of antioxidant defence in diabetics via directly targeting heart seems to prevent diastolic dysfunction due to modulation of RyR2 macromolecular-complex thereby leading to normalized [Ca2+]i and [Zn2+]i in cardiomyocytes. PMID:24693334

  9. Antioxidants

    MedlinePlus

    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 ...

  10. Climate change and adaptational impacts in coastal systems: the case of sea defences.

    PubMed

    Firth, Louise B; Mieszkowska, Nova; Thompson, Richard C; Hawkins, Stephen J

    2013-09-01

    We briefly review how coastal ecosystems are responding to and being impacted by climate change, one of the greatest challenges facing society today. In adapting to rising and stormier seas associated with climate change, coastal defence structures are proliferating and becoming dominant coastal features, particularly in urbanised areas. Whilst the primary function of these structures is to protect coastal property and infrastructure, they inevitably have a significant secondary impact on the local environment and ecosystems. In this review we outline some of the negative and positive effects of these structures on physical processes, impacts on marine species, and the novel engineering approaches that have been employed to improve the ecological value of these structures in recent years. Finally we outline guidelines for an environmentally sensitive approach to design of such structures in the marine environment. PMID:23900344

  11. Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study.

    PubMed

    Sadowska-Krępa, E; Kłapcińska, B; Podgórski, T; Szade, B; Tyl, K; Hadzik, A

    2015-06-01

    The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years) taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood samples were taken before and immediately after the test and after 1 h of recovery. Blood antioxidant status was evaluated based on activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], glutathione reductase [GR]), concentrations of non-enzymatic antioxidants (reduced glutathione [GSH], uric acid), total plasma polyphenols, ferric reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and activities of creatine kinase (CK) and lactate dehydrogenase (LDH) as muscle damage markers. In order to evaluate potential health benefits of the acai berry, the post-treatment changes in lipid profile parameters (triglycerides, cholesterol and its fractions) were analysed. Six weeks' consumption of acai berry-based juice blend had no effect on sprint performance, but it led to a marked increase in the total antioxidant capacity of plasma, attenuation of the exercise-induced muscle damage, and a substantial improvement of serum lipid profile. These findings strongly support the view of the health benefits of supplementation with the acai berry-based juice blend, mainly attributed to its high total polyphenol content and the related high in vivo antioxidant and hypocholesterolaemic activities of this supplement. PMID:26060341

  12. Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study

    PubMed Central

    Kłapcińska, B; Podgórski, T; Szade, B; Tyl, K; Hadzik, A

    2015-01-01

    The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years) taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood samples were taken before and immediately after the test and after 1 h of recovery. Blood antioxidant status was evaluated based on activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], glutathione reductase [GR]), concentrations of non-enzymatic antioxidants (reduced glutathione [GSH], uric acid), total plasma polyphenols, ferric reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and activities of creatine kinase (CK) and lactate dehydrogenase (LDH) as muscle damage markers. In order to evaluate potential health benefits of the acai berry, the post-treatment changes in lipid profile parameters (triglycerides, cholesterol and its fractions) were analysed. Six weeks’ consumption of acai berry-based juice blend had no effect on sprint performance, but it led to a marked increase in the total antioxidant capacity of plasma, attenuation of the exercise-induced muscle damage, and a substantial improvement of serum lipid profile. These findings strongly support the view of the health benefits of supplementation with the acai berry-based juice blend, mainly attributed to its high total polyphenol content and the related high in vivo antioxidant and hypocholesterolaemic activities of this supplement. PMID:26060341

  13. A novel rice C2H2-type zinc finger protein, ZFP36, is a key player involved in abscisic acid-induced antioxidant defence and oxidative stress tolerance in rice

    PubMed Central

    Zhang, Hong; Liu, Yanpei; Wen, Feng; Yao, Dongmei; Wang, Lu; Guo, Jin; Ni, Lan; Zhang, Aying; Tan, Mingpu; Jiang, Mingyi

    2014-01-01

    C2H2-type zinc finger proteins (ZFPs) have been shown to play important roles in the responses of plants to oxidative and abiotic stresses, and different members of this family might have different roles during stresses. Here a novel abscisic acid (ABA)- and hydrogen peroxide (H2O2)-responsive C2H2-type ZFP gene, ZFP36, is identified in rice. The analyses of ZFP36-overexpressing and silenced transgenic rice plants showed that ZFP36 is involved in ABA-induced up-regulation of the expression and the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). Overexpression of ZFP36 in rice plants was found to elevate the activities of antioxidant enzymes and to enhance the tolerance of rice plants to water stress and oxidative stress. In contrast, an RNA interference (RNAi) mutant of ZFP36 had lower activities of antioxidant enzymes and was more sensitive to water stress and oxidative stress. ABA-induced H2O2 production and ABA-activated mitogen-activated protein kinases (MAPKs) were shown to regulate the expression of ZFP36 in ABA signalling. On the other hand, ZFP36 also regulated the expression of NADPH oxidase genes, the production of H2O2, and the expression of OsMPK genes in ABA signalling. These results indicate that ZFP36 is required for ABA-induced antioxidant defence, for the tolerance of rice plants to water stress and oxidative stress, and for the regulation of the cross-talk between NADPH oxidase, H2O2, and MAPK in ABA signalling. PMID:25071223

  14. Analysis of defence systems and a conjugative IncP-1 plasmid in the marine polyaromatic hydrocarbons-degrading bacterium Cycloclasticus sp. 78-ME.

    PubMed

    Yakimov, Michail M; Crisafi, Francesca; Messina, Enzo; Smedile, Francesco; Lopatina, Anna; Denaro, Renata; Pieper, Dietmar H; Golyshin, Peter N; Giuliano, Laura

    2016-08-01

    Marine prokaryotes have evolved a broad repertoire of defence systems to protect their genomes from lateral gene transfer including innate or acquired immune systems and infection-induced programmed cell suicide and dormancy. Here we report on the analysis of multiple defence systems present in the genome of the strain Cycloclasticus sp. 78-ME isolated from petroleum deposits of the tanker 'Amoco Milford Haven'. Cycloclasticus are ubiquitous bacteria globally important in polyaromatic hydrocarbons degradation in marine environments. Two 'defence islands' were identified in 78-ME genome: the first harbouring CRISPR-Cas with toxin-antitoxin system, while the second was composed by an array of genes for toxin-antitoxin and restriction-modification proteins. Among all identified spacers of CRISPR-Cas system only seven spacers match sequences of phages and plasmids. Furthermore, a conjugative plasmid p7ME01, which belongs to a new IncP-1θ ancestral archetype without any accessory mobile elements was found in 78-ME. Our results provide the context to the co-occurrence of diverse defence mechanisms in the genome of Cycloclasticus sp. 78-ME, which protect the genome of this highly specialized PAH-degrader. This study contributes to the further understanding of complex networks established in petroleum-based microbial communities. PMID:27345842

  15. Impacts of low doses of pesticide mixtures on liver cell defence systems.

    PubMed

    Rouimi, Patrick; Zucchini-Pascal, Nathalie; Dupont, Gwendoline; Razpotnik, Andrej; Fouché, Edwin; De Sousa, Georges; Rahmani, Roger

    2012-08-01

    Low amounts of residual pesticides are present in the environment, often as mixtures of chemicals which contaminate drinking water and food, being a source of chronic exposure for humans and a growing matter of concern in public health policy. Despite of the needs and growing investigation, little is known about the impact of low doses and mixtures of these chemicals on human health. The purpose of this study was to enlighten if modifications of liver cell metabolic- and/or defence-related capacities could occur under such exposures. In vitro perturbations of several metabolic, stress and survival pathways in human and mice cultured hepatocytes and liver cells were evaluated under exposure to low doses of single molecules or equimolecular combinations of the three pesticides, atrazine, chlorpyrifos and endosulfan. Mainly phases I and II enzymes of detoxification were found modulated, together with apoptotic process deregulation. Hence, CYP3A4 and CYP3A11 were upregulated in primary cultured human and mouse hepatocytes, respectively. These inductions were correlated to an anti-apoptotic process (increased Bcl-xL/Bax ratio, inhibition of the PARP protein cleavage). Such disturbances in pathways involved in cell protection may possibly account for initiation of pathologies or decrease in drugs efficiency in humans exposed to multiple environmental contaminants. PMID:22515965

  16. Antioxidant systems in supporting environmental and programmed adaptations to low temperatures.

    PubMed

    Blagojević, Dusko P

    2007-01-01

    Hetero and endothermic adaptive responses arising as a result of natural responses to environmental cues include antioxidant systems that support adaptations to environmental low temperatures in the broadest sense. These temperatures induce phase changes in energy production and consequently changes in the concentration of reactive oxygen species (ROS). The latter may lead to oxidative stress and the impairment of cellular homeostasis and antioxidant defence systems (ADS) scavenge the ROS so generated. In endotherms the ADS responds to oxidative pressure during acute cold stress conditions, this response is tissue specific and does not extend to prevent other oxidative damage. The early acute phase of cold exposure is accompanied by a significant depletion in redox equivalents. Under such conditions it is questionable if ADS has the capacity to neutralize elevated levels of ROS since there is also an increased energy demand and enhanced ATP consumption. Prolonged exposure to cold leads to ADS adaptation. Hibernators and freeze-tolerant species elevate their ADS before hibernation or freezing in order to prepare for and cope with re-awakening. The involvement of ROS and the role of the ADS in organisms subjected to low temperatures are features intercalated into physiological mechanisms of homestasis. The exact mechanisms for ADS regulation have not been fully defined and are the subject of many ongoing intriguing scientific investigations. PMID:17898903

  17. Effect of Terminalia arjuna on antioxidant defense system in cancer.

    PubMed

    Verma, Nibha; Vinayak, Manjula

    2009-01-01

    Constant production of reactive oxygen species (ROS) during aerobic metabolism is balanced by antioxidant defense system of an organism. Although low level of ROS is important for various physiological functions, its accumulation has been implicated in the pathogenesis of age-related diseases such as cancer and coronary heart disease and neurodegenerative disorders such as Alzheimer's disease. It is generally assumed that frequent consumption of phytochemicals derived from vegetables, fruits, tea and herbs may contribute to shift the balance towards an adequate antioxidant status. The present study is aimed to investigate the effect of aqueous extract of medicinal plant Terminalia arjuna on antioxidant defense system in lymphoma bearing AKR mice. Antioxidant action of T. arjuna is monitored by the activities of catalase, superoxide dismutase and glutathione S transferase which constitute major antioxidant defense system by scavenging ROS. These enzyme activities are low in lymphoma bearing mice indicating impaired antioxidant defense system. Oral administration of different doses of aqueous extract of T. arjuna causes significant elevation in the activities of catalase, superoxide dismutase and glutathione S transferase. T. arjuna is found to down regulate anaerobic metabolism by inhibiting the activity of lactate dehydrogenase in lymphoma bearing mice, which was elevated in untreated cancerous mice. The results indicate the antioxidant action of aqueous extract of T. arjuna, which may play a role in the anti carcinogenic activity by reducing the oxidative stress along with inhibition of anaerobic metabolism. PMID:18537039

  18. Simulated weightlessness down-regulated antioxidant defense system in rats

    NASA Astrophysics Data System (ADS)

    Li, Qi; Qu, Lina; Li, Yingxian; Bi, Lei; Huang, Zengming; Wang, Bo

    A variety of experiments suggest that space flight is associated with an increase in oxidative stress in organism The aim of the present study is to investigate whether or not simulated weightlessness by tail-suspension can affect the antioxidant defense system in rats and the possible protection effects of Chinese medicine named Liu Wei Di Huang Wan LWDHW Blood plasma of rats was taken after 21 days - tail-suspension for the assessment of the change of antioxidant defense system The total antioxidant capacity T-AOC was significantly decreased and the content of malondialdehyde MDA was increased after simulated weightlessness Activities of antioxidant enzymes such as superoxide dismutase and catalase were lower than those in the controlled groups However the activity of glutathione peroxidase was increased in comparison with the controlled groups Adequate dosage of LWDHW could inhibit the production of MAD and improve T-AOC in tail-suspension rats These results suggested that tail-suspension might break the oxidative antioxidative balance and down-regulate antioxidant defense system and Chinese medicine LWDHW was shown to protect rats from oxidative damage during simulated weightlessness Key words Simulated weightlessness Tail-suspension Antioxidant defense system Rats

  19. The arbuscular mycorrhizal symbiosis promotes the systemic induction of regulatory defence-related genes in rice leaves and confers resistance to pathogen infection.

    PubMed

    Campos-Soriano, Lidia; García-Martínez, José; San Segundo, Blanca

    2012-08-01

    Arbuscular mycorrhizal (AM) symbioses are mutualistic associations between soil fungi and most vascular plants. Their association benefits the host plant by improving nutrition, mainly phosphorus nutrition, and by providing increased capability to cope with adverse conditions. In this study, we investigated the transcriptional changes triggered in rice leaves as a result of AM symbiosis, focusing on the relevance of the plant defence response. We showed that root colonization by the AM fungus Glomus intraradices is accompanied by the systemic induction of genes that play a regulatory role in the host defence response, such as OsNPR1, OsAP2, OsEREBP and OsJAmyb. Genes involved in signal transduction processes (OsDUF26 and OsMPK6) and genes that function in calcium-mediated signalling processes (OsCBP, OsCaM and OsCML4) are also up-regulated in leaves of mycorrhizal rice plants in the absence of pathogen infection. In addition, the mycorrhizal rice plants exhibit a stronger induction of defence marker genes [i.e. pathogenesis-related (PR) genes] in their leaves in response to infection by the blast fungus Magnaporthe oryzae. Evidence indicates that mycorrhizal rice plants show enhanced resistance to the rice blast fungus. Overall, these results suggest that the protective effect of the AM symbiosis in rice plants relies on both the systemic activation of defence regulatory genes in the absence of pathogen challenge and the priming for stronger expression of defence effector genes during pathogen infection. The possible mechanisms involved in the mycorrhiza-induced resistance to M. oryzae infection are discussed. PMID:22212404

  20. Pseudomonas spp.-induced systemic resistance to Botrytis cinerea is associated with induction and priming of defence responses in grapevine.

    PubMed

    Verhagen, Bas W M; Trotel-Aziz, Patricia; Couderchet, Michel; Höfte, Monica; Aziz, Aziz

    2010-01-01

    Non-pathogenic rhizobacteria Pseudomonas spp. can reduce disease in plant tissues through induction of a defence state known as induced systemic resistance (ISR). This resistance is based on multiple bacterial determinants, but nothing is known about the mechanisms underlying rhizobacteria-induced resistance in grapevine. In this study, the ability of Pseudomonas fluorescens CHA0 and Pseudomonas aeruginosa 7NSK2 to induce resistance in grapevine against Botrytis cinerea is demonstrated. Both strains also triggered an oxidative burst and phytoalexin (i.e. resveratrol and viniferin) accumulation in grape cells and primed leaves for accelerated phytoalexin production upon challenge with B. cinerea. Treatment of cell cultures with crude cell extracts of bacteria strongly enhanced oxidative burst, but resulted in comparable amounts of phytoalexins and resistance to B. cinerea to those induced by living bacteria. This suggests the production of bacterial compounds serving as inducers of disease resistance. Using other strains with different characteristics, it is shown that P. fluorescens WCS417 (Pch-deficient), P. putida WCS358 (Pch- and SA-deficient) and P. fluorescens Q2-87 (a DAPG producer) were all capable of inducing resistance to an extent similar to that induced by CHA0. However, in response to WCS417 (Pch-negative) the amount of H2O2 induced is less than for the CHA0. WCS417 induced low phytoalexin levels in cells and lost the capacity to prime for phytoalexins in the leaves. This suggests that, depending on the strain, SA, pyochelin, and DAPG are potentially effective in inducing or priming defence responses. The 7NSK2 mutants, KMPCH (Pch- and Pvd-negative) and KMPCH-567 (Pch-, Pvd-, and SA-negative) induced only partial resistance to B. cinerea. However, the amount of H2O2 triggered by KMPCH and KMPCH-567 was similar to that induced by 7NSK2. Both mutants also led to a low level of phytoalexins in grapevine cells, while KMPCH slightly primed grapevine leaves

  1. A systems biology perspective on Nrf2-mediated antioxidant response

    SciTech Connect

    Zhang Qiang; Pi Jingbo; Woods, Courtney G.; Andersen, Melvin E.

    2010-04-01

    Cells in vivo are constantly exposed to reactive oxygen species (ROS) generated endogenously and exogenously. To defend against the deleterious consequences of ROS, cells contain multiple antioxidant enzymes expressed in various cellular compartments to scavenge these toxic species. Under oxidative stresses, these antioxidant enzymes are upregulated to restore redox homeostasis. Such an adaptive response results from the activation of a redox-sensitive gene regulatory network mediated by nuclear factor E2-related factor 2. To more completely understand how the redox control system is designed by nature to meet homeostatic goals, we have examined the network from a systems perspective using engineering approaches. As with man-made control devices, the redox control system can be decomposed into distinct functional modules, including transducer, controller, actuator, and plant. Cells achieve specific performance objectives by utilizing nested feedback loops, feedforward control, and ultrasensitive signaling motifs, etc. Given that endogenously generated ROS are also used as signaling molecules, our analysis suggests a novel mode of action to explain oxidative stress-induced pathological conditions and diseases. Specifically, by adaptively upregulating antioxidant enzymes, oxidative stress may inadvertently attenuate ROS signals that mediate physiological processes, resulting in aberrations of cellular functions and adverse consequences. Lastly, by simultaneously considering the two competing cellular tasks-adaptive antioxidant defense and ROS signaling-we re-examine the premise that dietary antioxidant supplements is generally beneficial to human health. Our analysis highlights some possible adverse effects of these widely consumed antioxidants.

  2. Antioxidants

    MedlinePlus

    ... carotene Lutein Lycopene Selenium Vitamin A Vitamin C Vitamin E Vegetables and fruits are rich sources of antioxidants. There is good ... eating a diet with lots of vegetables and fruits is healthy and lowers risks ... smokers. High doses of vitamin E may increase risks of prostate cancer and ...

  3. Plasticity of the β-Trefoil Protein Fold in the Recognition and Control of Invertebrate Predators and Parasites by a Fungal Defence System

    PubMed Central

    Butschi, Alex; Wälti, Martin A.; Egloff, Pascal; Stutz, Katrin; Yan, Shi; Wilson, Iain B. H.; Hengartner, Michael O.; Aebi, Markus; Allain, Frédéric H.-T.; Künzler, Markus

    2012-01-01

    Discrimination between self and non-self is a prerequisite for any defence mechanism; in innate defence, this discrimination is often mediated by lectins recognizing non-self carbohydrate structures and so relies on an arsenal of host lectins with different specificities towards target organism carbohydrate structures. Recently, cytoplasmic lectins isolated from fungal fruiting bodies have been shown to play a role in the defence of multicellular fungi against predators and parasites. Here, we present a novel fruiting body lectin, CCL2, from the ink cap mushroom Coprinopsis cinerea. We demonstrate the toxicity of the lectin towards Caenorhabditis elegans and Drosophila melanogaster and present its NMR solution structure in complex with the trisaccharide, GlcNAcβ1,4[Fucα1,3]GlcNAc, to which it binds with high specificity and affinity in vitro. The structure reveals that the monomeric CCL2 adopts a β-trefoil fold and recognizes the trisaccharide by a single, topologically novel carbohydrate-binding site. Site-directed mutagenesis of CCL2 and identification of C. elegans mutants resistant to this lectin show that its nematotoxicity is mediated by binding to α1,3-fucosylated N-glycan core structures of nematode glycoproteins; feeding with fluorescently labeled CCL2 demonstrates that these target glycoproteins localize to the C. elegans intestine. Since the identified glycoepitope is characteristic for invertebrates but absent from fungi, our data show that the defence function of fruiting body lectins is based on the specific recognition of non-self carbohydrate structures. The trisaccharide specifically recognized by CCL2 is a key carbohydrate determinant of pollen and insect venom allergens implying this particular glycoepitope is targeted by both fungal defence and mammalian immune systems. In summary, our results demonstrate how the plasticity of a common protein fold can contribute to the recognition and control of antagonists by an innate defence mechanism

  4. Effects of oxidised dietary fish oil and high-dose vitamin E supplementation on growth performance, feed utilisation and antioxidant defence enzyme activities of juvenile large yellow croaker (Larmichthys crocea).

    PubMed

    Wang, Jun; Xu, Houguo; Zuo, Rantao; Mai, Kangsen; Xu, Wei; Ai, Qinghui

    2016-05-01

    This study was conducted to elucidate the effects of oxidised dietary lipids and high-dose vitamin E (VE) on growth performance and immune responses of large yellow croaker. Juvenile fish (initial average body weight of 7·82 (sem 0·68) g) were fed diets containing either fresh fish oil (fresh diet, peroxide value (POV)=1·72 mEq/kg) or fish oil oxidised to varying degrees (oxidised diets, POV=28·29-104·21 mEq/kg), with or without supplementary 600 mg VE/kg diet, for 10 weeks in floating cages. Growth was significantly lower and feed intake (g/100 g body weight per d) was higher in fish fed the oxidised diet. Supplementation with VE increased the growth of fish fed the oxidised diets, but significantly decreased the growth of fish fed the fresh diet. Hepatosomatic index increased with increasing dietary POV and decreased with VE supplementation. Hepatic catalase activity, superoxide dismutase (SOD) activity and malondialdehyde content were significantly higher in fish fed the oxidised diets, and these values decreased significantly following VE supplementation. However, hepatic SOD activity was enhanced by VE supplementation in fish fed the fresh diet. Air-exposure mortality was significantly increased by dietary POV, and this effect was inhibited by VE supplementation. These results suggest that dietary oxidised fish oil could stimulate the activities of antioxidant defence enzymes in stressed large yellow croaker. High-dose VE supplementation can alleviate oxidative stress of large yellow croaker fed oxidised fish oil, but can exert deleterious effects on fish in the absence of oxidative stress. PMID:26948923

  5. The role of glycans in immune evasion: the human fetoembryonic defence system hypothesis revisited

    PubMed Central

    Clark, Gary F.

    2014-01-01

    Emerging data suggest that mechanisms to evade the human immune system may be shared by the conceptus, tumour cells, persistent pathogens and viruses. It is therefore timely to revisit the human fetoembryonic defense system (Hu-FEDS) hypothesis that was proposed in two papers in the 1990s. The initial paper suggested that glycoconjugates expressed in the human reproductive system inhibited immune responses directed against gametes and the developing human by employing their carbohydrate sequences as functional groups. These glycoconjugates were proposed to block specific binding interactions and interact with lectins linked to signal transduction pathways that modulated immune cell functions. The second article suggested that aggressive tumour cells and persistent pathogens (HIV, H. pylori, schistosomes) either mimicked or acquired the same carbohydrate functional groups employed in this system to evade immune responses. This subterfuge enabled these pathogens and tumour cells to couple their survival to the human reproductive imperative. The Hu-FEDS model has been repeatedly tested since its inception. Data relevant to this model have also been obtained in other studies. Herein, the Hu-FEDS hypothesis is revisited in the context of these more recent findings. Far more supportive evidence for this model now exists than when it was first proposed, and many of the original predictions have been validated. This type of subterfuge by pathogens and tumour cells likely applies to all sexually reproducing metazoans that must protect their gametes from immune responses. Intervention in these pathological states will likely remain problematic until this system of immune evasion is fully understood and appreciated. PMID:24043694

  6. Systemic RNA delivery to dendritic cells exploits antiviral defence for cancer immunotherapy.

    PubMed

    Kranz, Lena M; Diken, Mustafa; Haas, Heinrich; Kreiter, Sebastian; Loquai, Carmen; Reuter, Kerstin C; Meng, Martin; Fritz, Daniel; Vascotto, Fulvia; Hefesha, Hossam; Grunwitz, Christian; Vormehr, Mathias; Hüsemann, Yves; Selmi, Abderraouf; Kuhn, Andreas N; Buck, Janina; Derhovanessian, Evelyna; Rae, Richard; Attig, Sebastian; Diekmann, Jan; Jabulowsky, Robert A; Heesch, Sandra; Hassel, Jessica; Langguth, Peter; Grabbe, Stephan; Huber, Christoph; Türeci, Özlem; Sahin, Ugur

    2016-06-16

    Lymphoid organs, in which antigen presenting cells (APCs) are in close proximity to T cells, are the ideal microenvironment for efficient priming and amplification of T-cell responses. However, the systemic delivery of vaccine antigens into dendritic cells (DCs) is hampered by various technical challenges. Here we show that DCs can be targeted precisely and effectively in vivo using intravenously administered RNA-lipoplexes (RNA-LPX) based on well-known lipid carriers by optimally adjusting net charge, without the need for functionalization of particles with molecular ligands. The LPX protects RNA from extracellular ribonucleases and mediates its efficient uptake and expression of the encoded antigen by DC populations and macrophages in various lymphoid compartments. RNA-LPX triggers interferon-α (IFNα) release by plasmacytoid DCs and macrophages. Consequently, DC maturation in situ and inflammatory immune mechanisms reminiscent of those in the early systemic phase of viral infection are activated. We show that RNA-LPX encoding viral or mutant neo-antigens or endogenous self-antigens induce strong effector and memory T-cell responses, and mediate potent IFNα-dependent rejection of progressive tumours. A phase I dose-escalation trial testing RNA-LPX that encode shared tumour antigens is ongoing. In the first three melanoma patients treated at a low-dose level, IFNα and strong antigen-specific T-cell responses were induced, supporting the identified mode of action and potency. As any polypeptide-based antigen can be encoded as RNA, RNA-LPX represent a universally applicable vaccine class for systemic DC targeting and synchronized induction of both highly potent adaptive as well as type-I-IFN-mediated innate immune mechanisms for cancer immunotherapy. PMID:27281205

  7. Systemic RNA delivery to dendritic cells exploits antiviral defence for cancer immunotherapy

    NASA Astrophysics Data System (ADS)

    Kranz, Lena M.; Diken, Mustafa; Haas, Heinrich; Kreiter, Sebastian; Loquai, Carmen; Reuter, Kerstin C.; Meng, Martin; Fritz, Daniel; Vascotto, Fulvia; Hefesha, Hossam; Grunwitz, Christian; Vormehr, Mathias; Hüsemann, Yves; Selmi, Abderraouf; Kuhn, Andreas N.; Buck, Janina; Derhovanessian, Evelyna; Rae, Richard; Attig, Sebastian; Diekmann, Jan; Jabulowsky, Robert A.; Heesch, Sandra; Hassel, Jessica; Langguth, Peter; Grabbe, Stephan; Huber, Christoph; Türeci, Özlem; Sahin, Ugur

    2016-06-01

    Lymphoid organs, in which antigen presenting cells (APCs) are in close proximity to T cells, are the ideal microenvironment for efficient priming and amplification of T-cell responses. However, the systemic delivery of vaccine antigens into dendritic cells (DCs) is hampered by various technical challenges. Here we show that DCs can be targeted precisely and effectively in vivo using intravenously administered RNA-lipoplexes (RNA-LPX) based on well-known lipid carriers by optimally adjusting net charge, without the need for functionalization of particles with molecular ligands. The LPX protects RNA from extracellular ribonucleases and mediates its efficient uptake and expression of the encoded antigen by DC populations and macrophages in various lymphoid compartments. RNA-LPX triggers interferon-α (IFNα) release by plasmacytoid DCs and macrophages. Consequently, DC maturation in situ and inflammatory immune mechanisms reminiscent of those in the early systemic phase of viral infection are activated. We show that RNA-LPX encoding viral or mutant neo-antigens or endogenous self-antigens induce strong effector and memory T-cell responses, and mediate potent IFNα-dependent rejection of progressive tumours. A phase I dose-escalation trial testing RNA-LPX that encode shared tumour antigens is ongoing. In the first three melanoma patients treated at a low-dose level, IFNα and strong antigen-specific T-cell responses were induced, supporting the identified mode of action and potency. As any polypeptide-based antigen can be encoded as RNA, RNA-LPX represent a universally applicable vaccine class for systemic DC targeting and synchronized induction of both highly potent adaptive as well as type-I-IFN-mediated innate immune mechanisms for cancer immunotherapy.

  8. Ontogenesis of the secretory immune system and innate defence factors in human parotid glands.

    PubMed Central

    Thrane, P S; Rognum, T O; Brandtzaeg, P

    1991-01-01

    Immunoglobulin-producing cells and epithelial expression of secretory component (SC), amylase, lysozyme (Ly) and lactoferrin (Lf) were studied by immunohistochemistry to obtain information about the development of mucosal immunity. Tissue specimens were obtained from 20 fetal and 40 postnatal parotid glands. (1) Fetal specimens. Occasional IgM- and IgA- but no IgD-, IgG- or IgE- producing cells were seen (ratios, IgM:IgA:IgD:IgG:IgE approximately 4:1:0:0:0). The IgAl subclass dominated (median 90%, range 50-95%) and these cells were mostly J-chain-positive (median 97%, range 94-98%). Only few IgA2-producing cells were seen (median 10%, range 5-50%) and they were also mostly J-chain-positive (median 99%, range 98-100%). Amylase, Ly and Lf were most prominent in early fetal life, while only small amounts of SC were present. (2) Postnatal specimens. Secretory component increased markedly along with a growing number of IgA- and IgD-producing cells (IgA:IgM:IgD:IgG:IgE approximately 4:2:1:1:0). The IgAl subclass remained predominant (median 65%, range 50-90%) although the proportion of IgA2-positive cells tended to be raised (median 35%, range 10-50%). Most IgAl (median 97%, range 67-100%) and IgA2 (median 94%, range 75-100%) cells were J-chain-positive. These features probably reflected local activation of the immune system in response to environmental factors. The amount of amylase, Ly and Lf decreased shortly after delivery, perhaps because the cellular stores were emptied by postnatal increase in secretory activity. Images Fig. 4 PMID:1934601

  9. Involvement of the antioxidant system in differential sensitivity of Carcinus maenas to fenitrothion exposure.

    PubMed

    Rodrigues, A P; Gravato, C; Guimarães, L

    2013-10-01

    Carcinus maenas is an invertebrate with worldwide distribution and high ability to adapt to different environments, which is frequently used in environmental monitoring. Despite this, it is not clear how historical exposure to moderate contamination may influence sensitivity to further chemical stress in this important decapod species. This study investigated differential responses to organophosphate fenitrothion of C. maenas from a moderately contaminated estuary and a low impacted one, using in vitro and in vivo biomarker assays. To clarify potential differences in sensitivity, a biochemical characterisation of muscle cholinesterases was first performed. The results indicated acetylcholinesterase (AChE) as the main form present in C. maenas muscle. Exposure assays revealed that crabs from the moderately contaminated site were less sensitive to fenitrothion showing lower AChE inhibition than those from the low impacted site. Other biomarker changes detected in these animals were: increased anaerobic metabolism (muscle lactate dehydrogenase), enhanced phase II biotransformation (glutathione S-transferases in the digestive gland) and antioxidant defences (i.e., activities of glutathione reductase, glutathione peroxidase and catalase, and levels of total glutathiones in the digestive gland). Altogether, the results pointed out a role for the glutathione redox system towards tolerance to fenitrothion exposure. PMID:24056931

  10. Antioxidant Compounds from Vegetable Matrices: Biosynthesis, Occurrence, and Extraction Systems.

    PubMed

    Baiano, Antonietta; Del Nobile, Matteo Alessandro

    2016-09-01

    Natural antioxidants such as vitamin C, tocopherols and tocotrienols, carotenoids, and phenolic compounds are largely distributed in plant products. Most of them are not synthesized by human and need to be introduced with diet according to the Recommended Daily Intake (RDI). This work was aimed to give a comprehensive overview on the occurrence of these antioxidants in plants, in particular in plant foods, on the mechanisms of biosynthesis, and on conventional (liquid-liquid or solid-liquid extraction, Soxhlet) and innovative (enzymatic-assisted, pressurized fluid, supercritical fluid, ultrasound-assisted, microwave-assisted, pulsed electric field) extraction systems. PMID:25751787

  11. Pineal proteins upregulate specific antioxidant defense systems in the brain.

    PubMed

    Bharti, Vijay K; Srivastava, R S

    2009-01-01

    The neuroendocrine functions of the pineal affect a wide variety of glandular and nervous system processes. Beside melatonin (MEL), the pineal gland secretes and expresses certain proteins essential for various physiological functions. It has been suggested that the pineal gland may also have an antioxidant role due to secretory product other than MEL. Therefore, the present study was designed to study the effect of buffalo (Bubalus bubalis) pineal proteins (PP) on the antioxidant defense 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. PMID:20357930

  12. Systemic reduction of rice blast by inhibitors of antioxidant enzymes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systemic acquired disease resistance (SAR) of plants may result from an oxidative burst in their tissues caused by both increased production of ROS and decreased antioxidant activity, in particular, enzymatic. Here we tested whether the exogenous inhibitors of superoxide dismutase (SOD) and catalase...

  13. Impact of the dual defence system of Plantago lanceolata (Plantaginaceae) on performance, nutrient utilisation and feeding choice behaviour of Amata mogadorensis larvae (Lepidoptera, Erebidae).

    PubMed

    Pankoke, Helga; Gehring, René; Müller, Caroline

    2015-11-01

    Iridoid glycosides are plant defence compounds with potentially detrimental effects on non-adapted herbivores. Some plant species possess β-glucosidases that hydrolyse iridoid glycosides and thereby release protein-denaturing aglycones. To test the hypothesis that iridoid glycosides and plant β-glucosidases form a dual defence system, we used Plantago lanceolata and a polyphagous caterpillar species. To analyse the impact of leaf-age dependent differences in iridoid glycoside concentrations and β-glucosidase activities on insect performance, old or young leaves were freeze-dried and incorporated into artificial diets or were provided freshly to the larvae. We determined larval consumption rates and the amounts of assimilated nitrogen. Furthermore, we quantified β-glucosidase activities in artificial diets and fresh leaves and the amount of iridoid glycosides that larvae feeding on fresh leaves ingested and excreted. Compared to fresh leaves, caterpillars grew faster on artificial diets, on which larval weight gain correlated positively to the absorbed amount of nitrogen. When feeding fresh young leaves, larvae even lost weight and excreted only minute proportions of the ingested iridoid glycosides intact with the faeces, indicating that the hydrolysis of these compounds might have interfered with nitrogen assimilation and impaired larval growth. To disentangle physiological effects from deterrent effects of iridoid glycosides, we performed dual choice feeding assays. Young leaves, their methanolic extracts and pure catalpol reduced larval feeding in comparison to the respective controls, while aucubin had no effect on larval consumption. We conclude that the dual defence system of P. lanceolata consisting of iridoid glycosides and β-glucosidases interferes with the nutrient utilisation via the hydrolysis of iridoid glycosides and also mediates larval feeding behaviour in a concentration- and substance-specific manner. PMID:26306994

  14. Vitamin A supplementation modifies the antioxidant system in rats

    PubMed Central

    Cha, Jung-Hwa; Yu, Qi-Ming

    2016-01-01

    BACKGROUND/OBJECTIVES It has been shown that vitamin A supplementation has different effects on skeletal health and the antioxidant system. Deficiency or excess of this vitamin can lead to health problems. Vitamin A can work as either an antioxidant or prooxidant depending on its concentration. The present study was conducted to investigate the effects of different doses of vitamin A supplementation on the antioxidant system in rats. MATERIALS/METHODS Forty Spargue-Dawley male rats were divided into four groups according to the dose of vitamin A received: 0 (A0), 4,000 (A1), 8,000 (A2), and 20,000 (A3) IU retinyl palmitate/kg diet. After a feeding period of 4 wks, lipid peroxide levels, glutathione concentration, antioxidant enzyme activities, and vitamins A and E concentrations were measured. Histopathological changes were observed in rat liver tissue using an optical microscope and transmission electron microscope. RESULTS Lipid peroxide levels in plasma were significantly decreased in the A1 and A2 groups compared to the A0 rats. Erythrocyte catalase and hepatic superoxide dismutase activities of the A2 group were significantly higher than those of the A0 group. Hepatic glutathione peroxidase activity was significantly lower in the A3 group compared to the other groups. Total glutathione concentrations were significantly higher in the A1 and A2 groups than in the A0 group. Histological examination of liver tissue showed that excessive supplementation of vitamin A might lead to lipid droplet accumulation and nuclear membrane deformation. CONCLUSIONS These results indicate that appropriate supplementation of vitamin A might have a beneficial effect on the antioxidant system in rats. PMID:26865913

  15. Antioxidant relevance to human health.

    PubMed

    Wahlqvist, Mark L

    2013-01-01

    Human ecology requires both oxygen and water with the generation from food of an immediate energy source, ATP, by oxidative phosphorylation. A continuing balance between oxidation and antioxidation is necessary for longer less-disabled lives, taking account of oxidative stresses and the critical roles of oxidants in defence against infection, tissue repair and signalling. Antioxidant capacity is derived both exogenously (from food, beverage and sunlight) and endogenously (from enzymatic and non-enzymatic pathways). A number of oxidant food factors service antioxidant metallo-enzymes. The capacity operates extra- or intracellularly. Uric acid is the major antioxidant in primate blood. Uric acid synthesis is increased by dietary fructose from fruit, sugary foods and drinks. This indirect antioxidant effect of fruit is separate from that attributable to its flavonoids. Alcohol also increases serum uric acid. Urate excess and retention is associated with disease. The high prevalence of hyperuricaemia in NE Asia presents a major public health dilemma in regard to putative benefits and risks. Foods with high antioxidant activity include berries, nuts and legumes, tomatoes and sweet potato leaves. Each of the antioxidants in these foods is pleiotropic being inter-alia anti-inflammatory, anti-angiogenic or anti-neoplastic. Moreover, food matrices and patterns contribute to the safety of antioxidant consumption. There is no evidence to date that isolated antioxidants as food supplements improve health outcomes or survival; and some that indicate unacceptable risk. Their use as biomarkers of food cannot justify their isolated use. Nevertheless, a spectrum of dietary pluripotential antioxidants for tissues, metabolic and immune systems is advantageous. PMID:23635359

  16. A newly discovered oxidant defence system and its involvement in the development of Aurelia aurita (Scyphozoa, Cnidaria): reactive oxygen species and elemental iodine control medusa formation.

    PubMed

    Berking, Stefan; Czech, Nicole; Gerharz, Melanie; Herrmann, Klaus; Hoffmann, Uwe; Raifer, Hartmann; Sekul, Guy; Siefker, Barbara; Sommerei, Andrea; Vedder, Fritz

    2005-01-01

    In Aurelia aurita, applied iodine induces medusa formation (strobilation). This process also occurs when the temperature is lowered. This was found to increase oxidative stress resulting in an increased production of iodine from iodide. One polyp produces several medusae (initially termed ephyrae) starting at the polyp's oral end. The spreading of strobilation down the body column is controlled by a feedback loop: ephyra anlagen decrease the tyrosine content in adjacent polyp tissue by producing melanin from tyrosine. Endogenous tyrosine is able to remove iodine by forming iodiferous tyrosine compounds. The reduced level of tyrosine causes the ephyra-polyp-border to move towards the basal end of the former polyp. We argue that an oxidant defence system may exist which makes use of iodide and tyrosine. Like other marine invertebrates, polyps of Aurelia contain iodide ions. Inevitably produced peroxides oxidise iodide into iodine. The danger to be harmed by iodine is strongly decreased by endogenous tyrosine which reacts with iodine to form iodiferous tyrosine compounds including thyroxin. Both substances together, iodide and tyrosine, form an efficient oxidant defence system which shields the tissue against damage by reactive oxygen species. In the course of evolution (from a species at the basis of the animal kingdom like Aurelia to a highly evolved species like man) the waste product thyroxin (indicating a high metabolic rate) has developed into a hormone which controls the metabolic rate. PMID:16281174

  17. Capability engineering: transforming defence acquisition in Canada

    NASA Astrophysics Data System (ADS)

    Pagotto, Jack; Walker, Robert S.

    2004-07-01

    Capability engineering, a new methodology with the potential to transform defence planning and acquisition, is described. The impact of capability engineering on existing defence business processes and organizations is being explored in Canada during the course of a four-year Technology Demonstration Project called Collaborative Capability Definition, Engineering and Management (CapDEM). Having completed the first of three experimentation spirals within this project, a high-level capability engineering process model has been defined. The process begins by mapping strategic defence guidance onto defence capabilities, using architectural models that articulate the people, process and materiel requirements of each capability when viewed as a system-of-systems. For a selected capability, metrics are rigorously applied to these models to assess their ability to deliver the military capability outcomes required by a set of predefined tasks and force planning scenarios. By programming the modification of these tasks and planning scenarios over time according to evolving capability objectives, quantifiable capability gaps are identified, that in turn drive the process towards options to close these gaps. The implementation plan for these options constitutes a capability evolution roadmap to support defence-investment decisions. Capability engineering is viewed as an essential enabler to meeting the objective of improved capability management, subsuming the functions of capability generation, sustainment and employment.

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

    PubMed Central

    2012-01-01

    Background Our objective was to determine antioxidant defence activity in healthy controls (HC) and healthy unaffected second-degree relatives of patients with early onset psychosis (HC-FHP), and to assess its relationship with familiar environment measured using the Family Environment Scale (FES). Methods We included 82 HC and 14 HC-FHP aged between 9 and 17 years. Total antioxidant status, lipid peroxidation, antioxidant enzyme activities and glutathione levels were determined in blood samples. Results There was a significant decrease in the total antioxidant level in the HC-FHP group compared with the HC group (OR = 2.94; p = 0.009), but no between-group differences in the Global Assessment of Functioning (GAF) scale scores. For the FES, the HC-FHP group had significantly higher scores in the cohesion (p = 0.007) and intellectual-cultural dimensions (p=0.025). After adjusting for these two FES dimensions, total antioxidant status remained significantly different between groups (OR = 10.86, p = 0.009). Conclusions Although causal relationships cannot be assumed, we can state that family environment is not playing a role in inducing oxidative stress in these healthy subjects. It could be hypothesized that families with affected relatives protect themselves from psychosis with positive environmental factors such as cohesion and intellectual-cultural activities. PMID:23158023

  19. Salicylic acid restrains nickel toxicity, improves antioxidant defence system and enhances the production of anticancer alkaloids in Catharanthus roseus (L.).

    PubMed

    Idrees, Mohd; Naeem, M; Aftab, Tariq; Khan, M Masroor A; Moinuddin

    2013-05-15

    Salicylic acid (SA) has been reported to ameliorate various stresses in plants. In order to explore the role of SA under nickel (Ni) stress, thirty-days old plants of periwinkle (Catharanthus roseus L.) were supplied with eight treatments comprising basal application of Ni (0, 50, 100 and 150 mg kg(-1)) and foliar application of SA (0 and 10(-5)M) under net house conditions. Ni application significantly reduced the growth attributes including plant height, leaf-area index and fresh and dry weights of shoot and root. Increasing Ni concentration led to a gradual decrease in photosynthetic parameters and activities of nitrate reductase and carbonic anhydrase. The plants, undergoing Ni stress, exhibited a significant increase in the activity of superoxide dismutase, catalase and peroxidase together with an increase in electrolyte leakage and proline content. Total alkaloid content was also declined in Ni-treated plants. Foliar application of SA (10(-5)M) reduced the deleterious effects of Ni on plant growth, accelerating the restoration of growth processes. SA also improved the total alkaloid content under normal as well as adverse conditions. Foliar spray of SA significantly improved the content of anticancer alkaloids vincristine (by 22.2%) and vinblastine (by 50.0%) in plants treated with 150 mg kg(-1) of Ni. PMID:23597961

  20. Characterization of antioxidant system parameters in four freshwater fish species.

    PubMed

    Atli, Gülüzar; Canli, Esin G; Eroglu, Ali; Canli, Mustafa

    2016-04-01

    The potential use of antioxidant system parameters has gained considerable interest due to their pivotal role of detoxification mechanisms in environmental studies and culture fish point of view. Fish with different ecological needs may have different antioxidant capacity and response to environmental contaminants. Thus, the optimal working conditions and specific enzyme activities (Vmax and Km) of antioxidant system parameters (Superoxide dismutase, SOD; Catalase, CAT; Glutathione peroxidase, GPX; Glutathione reductase, GR and Glutathione S-transferase, GST) and glutathione (GSH) were determined in four commonly cultured freshwater fish species (tilapia; Oreochromis niloticus, carp; Cyprinus carpio, trout; Onchorhynchus mykiss and catfish; Clarias garipienus). Data showed that optimal concentrations of different buffers, pH and specific chemicals for each enzyme and GSH were similar in most cases for all fish species, except a few differences. The highest Vmax and Km values were found in carp for GPX and GST, though these values were the highest in tilapia, catfish and trout for CAT, SOD and GR, respectively. As a conclusion, optimization assays of these parameters in different bioindicator organisms based on their physiological and ecological differences may be useful for the aquatic ecosystem biomonitoring studies and also present fundamental data for utilization in aquaculture. PMID:26707186

  1. Local and systemic mycorrhiza-induced protection against the ectoparasitic nematode Xiphinema index involves priming of defence gene responses in grapevine

    PubMed Central

    Hao, Zhipeng; Fayolle, Léon; van Tuinen, Diederik; Chatagnier, Odile; Gianinazzi, Silvio; Gianinazzi-Pearson, Vivienne

    2012-01-01

    The ectoparasitic dagger nematode (Xiphinema index), vector of Grapevine fanleaf virus (GFLV), provokes gall formation and can cause severe damage to the root system of grapevines. Mycorrhiza formation by Glomus (syn. Rhizophagus) intraradices BEG141 reduced both gall formation on roots of the grapevine rootstock SO4 (Vitis berlandieri×V. riparia) and nematode number in the surrounding soil. Suppressive effects increased with time and were greater when the nematode was post-inoculated rather than co-inoculated with the arbuscular mycorrhizal (AM) fungus. Using a split-root system, decreased X. index development was shown in mycorrhizal and non-mycorrhizal parts of mycorrhizal root systems, indicating that both local and systemic induced bioprotection mechanisms were active against the ectoparasitic nematode. Expression analyses of ESTs (expressed sequence tags) generated in an SSH (subtractive suppressive hybridization) library, representing plant genes up-regulated during mycorrhiza-induced control of X. index, and of described grapevine defence genes showed activation of chitinase 1b, pathogenesis-related 10, glutathione S-transferase, stilbene synthase 1, 5-enolpyruvyl shikimate-3-phosphate synthase, and a heat shock proein 70-interacting protein in association with the observed local and/or systemic induced bioprotection against the nematode. Overall, the data suggest priming of grapevine defence responses by the AM fungus and transmission of a plant-mediated signal to non-mycorrhizal tissues. Grapevine gene responses during AM-induced local and systemic bioprotection against X. index point to biological processes that are related either to direct effects on the nematode or to protection against nematode-imposed stress to maintain root tissue integrity. PMID:22407649

  2. Activation of antioxidant response element (ARE)-dependent genes by roasted coffee extracts.

    PubMed

    Yazheng, Liu; Kitts, David D

    2012-09-01

    Coffee beans contain numerous bioactive components that exhibit antioxidant capacity when assessed using both chemical, cell free, and biological, cell-based model systems. However, the mechanisms underlying the antioxidant effects of coffee in biological systems are not totally understood and in some cases vary considerably from results obtained with simpler in vitro chemical assays. In the present study, the physicochemical characteristics and antioxidant activity of roasted and non-roasted coffee extracts were investigated in both cell free (ORAC(FL)) and cell-based systems. A profile of antioxidant gene expression in cultured human colon adenocarcinoma Caco-2 cells treated with both roasted and non-roasted coffee extracts, respectively, was investigated using Real-Time polymerase chain reaction (PCR) array technology. Results demonstrated that the mechanisms of the antioxidant activity associated with coffee constituents assessed by the ORAC(FL) assay were different to those observed using an intracellular oxidation assay with Caco-2 cells. Moreover, roasted coffee (both light and dark roasted) extracts produced both increased- and decreased-expressions of numerous genes that are involved in the management of oxidative stress via the antioxidant defence system. The selective and specific positive induction of antioxidant response element (ARE)-dependent genes, including gastrointestinal glutathione peroxidase (GPX2), sulfiredoxin (SRXN1), thioredoxin reductase 1 (TXNRD1), peroxiredoxin 1 (PRDX1), peroxiredoxin 4 (PDRX4) and peroxiredoxin 6 (PDRX6) were identified with the activation of the endogenous antioxidant defence system in Caco-2 cells. PMID:22699814

  3. Antioxidant Activity of Flaxseed Extracts in Lipid Systems.

    PubMed

    Slavova-Kazakova, Adriana; Karamać, Magdalena; Kancheva, Vessela; Amarowicz, Ryszard

    2015-01-01

    The aim of this work was to compare the antioxidant activity of the extract of flaxseed and its alkaline hydrolysate in two model systems: lipid autoxidation of triacylglycerols of sunflower oil (TGSO)-in a homogeneous lipid media and during β-carotene-linoleate emulsion system. In addition, pure lignans were tested. The material was defatted with hexane and then phenolic compounds were extracted using dioxane-ethanol (50:50, v/v) mixture. Carbohydrates were removed from the crude extract using an Amberlite XAD-16 column chromatography. The content of total phenolic compounds in the crude extract and after alkaline hydrolysis was determined using a Folin-Ciocalteu's phenol reagent. Individual phenolic compounds were determined by nordihydroguaiaretic acid (RP-HPLC) method in gradient system. The alkaline hydrolysis increased the content of total phenolics in the extract approximately by 10%. In the extracts of flaxseed, phenolic compounds were present in the form of macromolecular complex. In the alkaline hydrolysate, secoisolariciresinol diglucoside (SDG) was found as the main phenolic compound. Small amounts of p-coumaric and ferulic acids were also determined. SDG and both extracts were not able to inhibit effectively lipid autoxidation. The kinetics of TGSO autoxidation at 80 °C in absence and in presence of the extract before hydrolysis (EBH) and after hydrolysis (EAH) was monitored and compared with known standard antioxidants. Ferulic acid (FA) and butylated hydroxyl toluene (BHT) showed much higher antioxidant efficiency and reactivity than that of both extracts. Secoisolariciresinol (SECO) showed a higher activity in both model systems than SDG. However, the activity of SECO was much lower than that of nordihydroquaiaretic acid (NDGA). PMID:26703558

  4. Oilseed rape seeds with ablated defence cells of the glucosinolate–myrosinase system. Production and characteristics of double haploid MINELESS plants of Brassica napus L.

    PubMed Central

    Ahuja, Ishita; Borgen, Birgit Hafeld; Hansen, Magnor; Honne, Bjørn Ivar; Müller, Caroline; Rohloff, Jens; Rossiter, John Trevor; Bones, Atle Magnar

    2011-01-01

    Oilseed rape and other crop plants of the family Brassicaceae contain a unique defence system known as the glucosinolate–myrosinase system or the ‘mustard oil bomb’. The ‘mustard oil bomb’ which includes myrosinase and glucosinolates is triggered by abiotic and biotic stress, resulting in the formation of toxic products such as nitriles and isothiocyanates. Myrosinase is present in specialist cells known as ‘myrosin cells’ and can also be known as toxic mines. The myrosin cell idioblasts of Brassica napus were genetically reprogrammed to undergo controlled cell death (ablation) during seed development. These myrosin cell-free plants have been named MINELESS as they lack toxic mines. This has led to the production of oilseed rape with a significant reduction both in myrosinase levels and in the hydrolysis of glucosinolates. Even though the myrosinase activity in MINELESS was very low compared with the wild type, variation was observed. This variability was overcome by producing homozygous seeds. A microspore culture technique involving non-fertile haploid MINELESS plants was developed and these plants were treated with colchicine to produce double haploid MINELESS plants with full fertility. Double haploid MINELESS plants had significantly reduced myrosinase levels and glucosinolate hydrolysis products. Wild-type and MINELESS plants exhibited significant differences in growth parameters such as plant height, leaf traits, matter accumulation, and yield parameters. The growth and developmental pattern of MINELESS plants was relatively slow compared with the wild type. The characteristics of the pure double haploid MINELESS plant are described and its importance for future biochemical, agricultural, dietary, functional genomics, and plant defence studies is discussed. PMID:21778185

  5. Allergic host defences.

    PubMed

    Palm, Noah W; Rosenstein, Rachel K; Medzhitov, Ruslan

    2012-04-26

    Allergies are generally thought to be a detrimental outcome of a mistargeted immune response that evolved to provide immunity to macroparasites. Here we present arguments to suggest that allergic immunity has an important role in host defence against noxious environmental substances, including venoms, haematophagous fluids, environmental xenobiotics and irritants. We argue that appropriately targeted allergic reactions are beneficial, although they can become detrimental when excessive. Furthermore, we suggest that allergic hypersensitivity evolved to elicit anticipatory responses and to promote avoidance of suboptimal environments. PMID:22538607

  6. Oxidative Damage and Antioxidative Therapy in Systemic Sclerosis

    PubMed Central

    Grygiel-Górniak, Bogna

    2014-01-01

    Systemic sclerosis (SSc) is an autoimmune connective tissue disorder of unknown etiology. This disease is characterized by a large variety of clinical patterns, which include the fibrosis of skin and visceral organs causing a variety of clinical manifestations. Genetic and environmental factors participate in the etiology of this disease; however, recently many studies underline the oxidative background influencing the course and complications of this disease. Reactive oxygen species (ROS) synthesized in SSc can mediate extra- and intracellular oxidative processes affecting endothelial cells and fibroblasts. The estimation of prooxidative markers in the pathogenesis of SSc can enable the identification of useful markers for disease activity and, thus, may help in planning appropriate therapy focusing on the fibrotic or vascular pattern. Recently, many attempts have been made to find antioxidative molecules (nutritional and pharmacological) reducing the prooxidant state in a variety of cells—mainly in endothelium and proliferating fibroblasts. This paper presents both the background of oxidative stress processes in systemic sclerosis mediated by different mechanisms and the evidence suggesting which of the dietary and pharmacological antioxidants can be used as therapeutic targets for this disease. PMID:25313270

  7. The response of antioxidant systems in Nostoc sphaeroides against UV-B radiation and the protective effects of exogenous antioxidants

    NASA Astrophysics Data System (ADS)

    Wang, Gaohong; Hu, Chunxiang; Li, Dunhai; Zhang, Delu; Li, Xiaoyan; Chen, Kun; Liu, Yongding

    UV radiation is one of many harmful factors found in space that are detrimental to organisms on earth in space exploration. In the present work, we examined the role of antioxidant system in Nostoc sphaeroides Kütz (Cyanobacterium) and the effects of exogenously applied antioxidant molecules on its photosynthetic rate under UV-B radiation. It was found that UV-B radiation promoted the activity of antioxidant system to protect photosystem II (PSII) and exogenously applied antioxidant: sodium nitroprusside (SNP) and N-acetylcysteine (NAC) had an obvious protection on PSII activity under UV-B radiation. The activity of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), peroxidase (POD, EC 1.11.1.7) and content of MDA (malondialdehyde) and ASC (ascorbate) were improved by 0.5 mM and 1 mM SNP, but 0.1 mM SNP decreased the activity of antioxidant system. Addition of exogenous NAC decreased the activity of SOD, POD, CAT and the content MDA and ASC. In contrast, exogenously applied NAC increased GSH content. The results suggest that exogenous SNP and NAC may protect algae by different mechanisms: SNP may play double roles as both sources of reactive free radicals as well as ROS scavengers in mediating the protective role of PSII on algae under UV-B radiation. On the other hand, NAC functions as an antioxidant or precursor of glutathione, which could protect PSII directly from UV-B radiation.

  8. Biomimetic nanomaterials: Development of protein coated nanoceria as a potential antioxidative nano-agent for the effective scavenging of reactive oxygen species in vitro and in zebrafish model.

    PubMed

    Bhushan, Bharat; Nandhagopal, Soundharapandiyan; Rajesh Kannan, Rajaretinam; Gopinath, P

    2016-10-01

    Reactive oxygen species (ROS) induced oxidative stress is one of the major factors responsible for initiation of several intracellular toxic events that leads to cell death. Antioxidant enzymes defence system of the body is responsible for maintaining the oxidative balance and cellular homeostasis. Several diseases are promoted by the excessive oxidative stress caused by the impaired antioxidant defence system that leads to oxidant/antioxidant imbalance in the body. In order to restore or precise the aberrant antioxidant system, a large number of catalytic nanoparticles has been screened so far. Exceptional antioxidative activity of nanoceria made it as a potential antioxidative nano-agent for the effective scavenging of toxic ROS. In this work albumin coated nanoceria (ANC) was synthesized and further characterised by various physicochemical techniques. The antioxidant and superoxide dismutase (SOD) assay confirm that the albumin coating do not alter the antioxidant potential of ANC. The biocompatibility and protective efficacy of ANC against oxidative stress was investigated both in vitro and in vivo in human lung epithelial (L-132) cells and zebrafish embryos, respectively. The inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM) and field emission scanning electron microscope (FE-SEM) analysis corroborates the uptake of ANC by the cells. Furthermore, the semi-quantitative gene expression studies confirmed that the ANC successfully defend the cells against oxidative stress by preserving the antioxidant system of the cells. Thus, the current work open up a new avenue for the development of improved antioxidant nano-drug therapies. PMID:27388966

  9. Systemic oxidant/antioxidant balance in human abdominal aortic aneurysm.

    PubMed

    Menteşe, Umit; Turan, Ibrahim; Usta, Sefer; Demir, Selim; Koral, Özgür; Öztaş Menteşe, Seda; Çavuşoğlu, Ismail Gökhan; Karahan, Süleyman Caner; Alver, Ahmet; Doğan, Orhan Veli; Aykan, Ahmet Çağrı

    2016-05-01

    The aim of this study was to evaluate the oxidant-antioxidant balance in patients with abdominal aortic aneurysms (AAA). Forty-two consecutive patients with AAA and 46 control subjects were included. Total oxidant status (TOS) and total antioxidant status (TAS) levels were measured and the oxidative stress index (OSI) value determined. Serum TOS and OSI values in patients with AAA were higher than those in the controls (p<0.001, p<0.001, respectively). There was a positive correlation between abdominal aortic diameters, serum TOS levels (r=0.592, p<0.001) and OSI values (r=0.598, p<0.001). A cut-off value of 17.68 µmol H2O2equivalent/L for TOS was associated with 86% sensitivity and 83% specificity and a cut-off value of 1.77 for OSI was associated with 86% sensitivity and 81% specificity for predicting AAA. Systemic oxidative imbalance develops in patients with AAA, particularly as a result of an increase in TOS. PMID:26228275

  10. Host defence mediates interspecific competition in ectoparasites.

    PubMed

    Bush, Sarah E; Malenke, Jael R

    2008-05-01

    1. Interspecific competition influences which, how many and where species coexist in biological communities. Interactions between species in different trophic levels can mediate interspecific competition; e.g. predators are known to reduce competition between prey species by suppressing their population sizes. A parallel phenomenon may take place in host-parasite systems, with host defence mediating competition between parasite species. 2. We experimentally investigated the impact of host defence (preening) on competitive interactions between two species of feather-feeding lice: 'wing' lice Columbicola columbae and 'body' lice Campanulotes compar. Both species are host-specific parasites that co-occur on rock pigeons Columba livia. 3. We show that wing lice and body lice compete and that host defence mediates the magnitude of this competitive interaction. 4. Competition is asymmetrical; wing louse populations are negatively impacted by body lice, but not vice versa. This competitive asymmetry is consistent with the fact that body lice predominate in microhabitats on the host's body that offer the most food and the most space. 5. Our results indicate that host-defence-mediated competition can influence the structure of parasite communities and may play a part in the evolution of parasite diversity. PMID:18194262

  11. Response of the physiological parameters of mango fruit (transpiration, water relations and antioxidant system) to its light and temperature environment.

    PubMed

    Léchaudel, Mathieu; Lopez-Lauri, Félicie; Vidal, Véronique; Sallanon, Huguette; Joas, Jacques

    2013-04-15

    Depending on the position of the fruit in the tree, mango fruit may be exposed to high temperature and intense light conditions that may lead to metabolic and physiological disorders and affect yield and quality. The present study aimed to determine how mango fruit adapted its functioning in terms of fruit water relations, epicarp characteristics and the antioxidant defence system in peel, to environmental conditions. The effect of contrasted temperature and light conditions was evaluated under natural solar radiation and temperature by comparing well-exposed and shaded fruit at three stages of fruit development. The sun-exposed and shaded peels of the two sides of the well-exposed fruit were also compared. Depending on fruit position within the canopy and on the side of a well-exposed fruit, the temperature gradient over a day affected fruit characteristics such as transpiration, as revealed by the water potential gradient as a function of the treatments, and led to a significant decrease in water conductance for well-exposed fruits compared to fruits within the canopy. Changes in cuticle thickness according to fruit position were consistent with those of fruit water conductance. Osmotic potential was also affected by climatic environment and harvest stage. Environmental conditions that induced water stress and greater light exposure, like on the sunny side of well-exposed fruit, increased the hydrogen peroxide, malondialdehyde and total and reduced ascorbate contents, as well as SOD, APX and MDHAR activities, regardless of the maturity stage. The lowest values were measured in the peel of the shaded fruit, that of the shaded side of well-exposed fruit being intermediate. Mango fruits exposed to water-stress-induced conditions during growth adapt their functioning by reducing their transpiration. Moreover, oxidative stress was limited as a consequence of the increase in antioxidant content and enzyme activities. This adaptive response of mango fruit to its

  12. Antioxidant activity of whey protein hydrolysates in milk beverage system.

    PubMed

    Mann, Bimlesh; Kumari, Anuradha; Kumar, Rajesh; Sharma, Rajan; Prajapati, Kishore; Mahboob, Shaik; Athira, S

    2015-06-01

    The aim of the present study was to evaluate the antioxidant activity of flavoured milk enriched with antioxidative whey protein hydrolysates (WPHs) by radical scavenging method. Whey protein concentrate (WPC) was hydrolyzed by using three commercial proteases; flavouzyme, alcalase and corolase PP and these WPHs were analyzed for degree of hydrolysis and antioxidant activity. The antioxidant activities of these WPHs were evaluated using ABTS method. Trolox equivalent antioxidant activity of all the hydrolysates i.e. flavourzyme (0.81 ± 0.04), alcalase (1.16 ± 0.05) and corolase (1.42 ± 0.12) was higher than the WPC (0.19 ± 0.01). Among these, whey protein hydrolysates prepared using corolase showed maximum antioxidant activity. Total 15 β-lactoglobulin, 1 α-lactoalbumin, and 6 β-casein derived peptide fragments were identified in the WPHs by LC-MS/MS. Due to their size and characteristic amino acid composition, all the identified peptides may contribute for the antioxidant activity. The strawberry and chocolate flavoured milk was supplemented with WPC and WPHs and 2 % addition has shown increase in antioxidant activity upto 42 %. The result suggests that WPH could be used as natural biofunctional ingredients in enhancing antioxidant properties of food products. PMID:26028704

  13. Effect of acetaminophen exposure in Oncorhynchus mykiss gills and liver: detoxification mechanisms, oxidative defence system and peroxidative damage.

    PubMed

    Ramos, A S; Correia, A T; Antunes, S C; Gonçalves, F; Nunes, B

    2014-05-01

    The increasing presence of pharmaceutical drugs in nature is cause of concern due to the occurrence of oxidative stress in non-target species. Acetaminophen is widely used in human medicine as an analgesic and antipyretic drug, and it is one of the most sold non-prescription drugs. The present study aimed to assess the toxic effects of acetaminophen (APAP) in Oncorhynchus mykiss following acute and chronic exposures in realistic levels. In order to evaluate the APAP effects in the rainbow trout, gills and liver were analyzed with biochemical biomarkers, such as catalase (CAT), total and selenium-dependent glutathione peroxidase (GPx), glutathione reductase (GRed) and glutathione-S-transferases (GSTs) activity and also lipid peroxidation levels (TBARS). The results obtained in all tests indicate that a significant response of oxidative stress was established, along with the increase of APAP concentrations. The establishment of an oxidative stress scenario occurred with the involvement of all tested biomarkers, sustaining a generalized set of pro-oxidative effects elicited by APAP. Additionally, the occurrence of oxidative damage strongly suggests the impairment of the antioxidant defense mechanism of O. mykiss. It is important to note that the occurrence of oxidative deleterious effects and peroxidative damages occurred for concentrations similar to those already reported for several freshwater ecosystems. The importance of these assumptions is further discussed under the scope of ecological relevance of the assessment of effects caused by pharmaceuticals in non-target organisms. PMID:24816177

  14. Hyperoside Induces Endogenous Antioxidant System to Alleviate Oxidative Stress

    PubMed Central

    Park, Ji Young; Han, Xia; Piao, Mei Jing; Oh, Min Chang; Fernando, Pattage Madushan Dilhara Jayatissa; Kang, Kyoung Ah; Ryu, Yea Seong; Jung, Uhee; Kim, In Gyu; Hyun, Jin Won

    2016-01-01

    Background: Hyperoside, a flavonoid which is mainly found in Hypericum perforatum L., has many biological effects. One of the most important effects is to prevent the oxidative stress induced by reactive oxygen species. However, the molecular mechanisms underlying its effect are not fully understood. Oxidative stress is implicated in the occurrence of various physical diseases. A wide array of enzymatic antioxidant defense systems include NADH: quinone oxidoreductase 1, superoxide dismutase, and heme oxygenase-1 (HO-1). In the present study, the protective effects of hyperoside against hydrogen peroxide-induced oxidative stress in human lens epithelial cells, HLE-B3, were investigated in terms of HO-1 induction. Methods: The protein and mRNA expressions of HO-1 were examined by Western blotting and reverse transcriptase-PCR assays, respectively. To evaluate the ability of hyperoside to activate nuclear factor erythroid 2-related factor 2 (Nrf2), Western blotting and electrophoretic mobility shift assay were performed with nuclear extracts prepared from HLE-B3 cells treated with hyperoside. The activation of extracellular signal-regulated kinase (ERK), the upstream kinase of Nrf2 signaling, was monitored by Western blot analysis. The protective effect of hyperoside in HLE-B3 cells against hydrogen peroxide was performed by MTT assay. Results: Hyperoside increased both the mRNA and protein expression of HO-1 in a time- and dose-dependent manner. In addition, hyperoside elevated the level of of Nrf2 and its antioxidant response element-binding activity, which was modulated by upstream of ERK. Moreover, it activated ERK and restored cell viability which was decreased by hydrogen peroxide. Conclusions: Hyperoside is an effective compound to protect cells against oxidative stress via HO-1 induction. PMID:27051648

  15. Effect of cultural system and essential oil treatment on antioxidant capacity in raspberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of cultural system and essential oil treatment on antioxidant enzyme activities, antioxidant capacities and flavonoid contents in raspberries were evaluated. Raspberries were hand-harvested from organic and conventional farms in Maryland, USA, and were treated with essential oils includi...

  16. Antioxidant properties of a new antioxidative peptide from algae protein waste hydrolysate in different oxidation systems.

    PubMed

    Sheih, I-Chuan; Wu, Tung-Kung; Fang, Tony J

    2009-07-01

    Microalgae have been a popular edible food, but there are no known reports on the antioxidative peptides derived from microalgae. The algae protein waste, which is normally discarded as animal feed, is a by-product during production of algae essence from microalgae, Chlorella vulgaris. Algae protein waste was hydrolyzed using pepsin, and a potent antioxidative peptide of VECYGPNRPQF was separated and isolated. The peptide could efficiently quench a variety of free radicals, including hydroxyl radical, superoxide radical, peroxyl radical, DPPH radical and ABTS radicals, and performed more efficiently than that observed for BHT, Trolox and peptides from marine protein sources in most cases. The purified peptide also has significant protective effects on DNA and prevents cellular damage caused by hydroxyl radicals. In addition, the peptide has gastrointestinal enzyme-resistance and no cytotoxicity observed in human lung fibroblasts cell lines (WI-38) in vitro. These results demonstrate that inexpensive algae protein waste could be a new alternative to produce antioxidative peptides. PMID:19299123

  17. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    PubMed Central

    Bozic, Iva; Savic, Danijela; Stevanovic, Ivana; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate) possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes—catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and ·O−2 production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells. PMID:26388737

  18. Sex differences in the cellular defence system against free radicals from oxygen or drug metabolites in rat.

    PubMed

    Julicher, R H; Sterrenberg, L; Haenen, G R; Bast, A; Noordhoek, J

    1984-12-01

    In this study, it was investigated whether sex-related differences in the protective mechanisms against oxygen radicals and free radical metabolites from drugs were present in rat liver, heart, and kidney. To that end, superoxide dismutase, catalase, the factors of the glutathione system and vitamin E were measured. In addition, NADPH-dependent cytochrome c-reductase activity was established, as this enzyme is involved in the formation of free radicals in the presence of many xenobiotics. The total capacity of the cellular systems that detoxify reactive oxygen species or free radical-drug metabolites seems to be higher in female liver as compared to male. No differences were found for heart and kidney tissue. It is hypothesized that female rats probably are less vulnerable for those drugs whose hepatotoxic action is induced by excessive formation of free radical species. PMID:6442559

  19. [Study of Antioxidant and Membranotropic Activities of Quinazoline Alkaloid Tryptanthrin Using Different Model Systems].

    PubMed

    Popov, A M; Osipov, A N; Korepanova, E A; Krivoshapko, O N; Shtoda, Yu P; Klimovich, A A

    2015-01-01

    A comparative study of antioxidant (radical-interceptor) properties of tryptanthrin (quinazoline alkaloid shows a high anti-inflammatory activity and it is found in many types of different families of higher plants and microorganisms, including the human microbiome) in the systems of 2,2'-azo-bis(2-methylpropionamidin)dihydrochloride-luminol and hemoglobin-hydrogen peroxide-luminol has been conducted and the influence on the permeability of planar bilayer lipid membranes is evaluated. Trolox was used as a reference antioxidant, and ascorbic acid and dihydroquercetin were taken as standards. Tryptanthrin exhibits very weak antioxidant activity, being markedly inferior to the reference standard and antioxidants while testing antioxidant activity in both studied systems. By the efficacy of antioxidative action the substrates in the systems studied can be arranged in the following order: dihydroquercetin > trolox > ascorbic acid > tryptanthrin. Antioxidant potential of tryptanthrin is approximately 1000 and 3000 times lower than that of trolox and bioflavonoid dihydroquercetine, respectively. Tryptanthrin causes no significant changes in the permeability of planar bilayer membranes in a dose range of 0.5 to. 10 μg/ml. Our data show that tryptanthrin displays no significant radical-interceptor and membranotropic activities. It can be assumed that the observed high anti-inflammatory activity of tryptanthrin is not related to the neutralizing effect against reactive oxygen species and the influence on the permeability of cell membranes. The anticipated mechanisms of biological activity of tryptanthrin are discussed. PMID:26394469

  20. Antioxidants, Oxidative Damage and Oxygen Deprivation Stress: a Review

    PubMed Central

    BLOKHINA, OLGA; VIROLAINEN, EIJA; FAGERSTEDT, KURT V.

    2003-01-01

    antioxidant status have been obtained. Experiments on overexpression of antioxidant production do not always result in the enhancement of the antioxidative defence, and hence increased antioxidative capacity does not always correlate positively with the degree of protection. Here we present a consideration of factors which possibly affect the effectiveness of antioxidant protection under oxygen deprivation as well as under other environmental stresses. Such aspects as compartmentalization of ROS formation and antioxidant localization, synthesis and transport of antioxidants, the ability to induce the antioxidant defense and cooperation (and/or compensation) between different antioxidant systems are the determinants of the competence of the antioxidant system. PMID:12509339

  1. Changes in the mitochondrial antioxidant systems in neurodegenerative diseases and acute brain disorders.

    PubMed

    Ruszkiewicz, Joanna; Albrecht, Jan

    2015-09-01

    Oxidative and nitrosative stress (ONS) contributes to the pathogenesis of most brain maladies, and the magnitude of ONS is related to the ability of cellular antioxidants to neutralize the accumulating reactive oxygen and nitrogen species (ROS/RNS). While the major ROS/RNS scavengers and regenerators of bio-oxidized molecules, superoxide dysmutases (SODs), glutathione (GSH), thioredoxin (Trx) and peroxiredoxin (Prx), are distributed in all cellular compartments. This review specifically focuses on the role of the systems operating in mitochondria. There is a growing consensus that the mitochondrial SOD isoform - SOD2 and GSH are critical for the cellular antioxidant defense. Variable changes of the expression or activities of one or more of the mitochondrial antioxidant systems have been documented in the brains derived from human patients and/or in animal models of neurodegenerative diseases (Alzheimer's disease, Parkinson's disease), cerebral ischemia, toxic brain cell damage associated with overexposure to mercury or excitotoxins, or hepatic encephalopathy. In many cases, ambiguity of the responses of the different antioxidant systems in one and the same disease needs to be more conclusively evaluated before the balance of the changes is viewed as beneficial or detrimental. Modulation of the mitochondrial antioxidant systems may in the future become a target of antioxidant therapy. PMID:25576182

  2. OXIDATION OF PHENOLIC ANTIOXIDANTS IN A RIVER SYSTEM

    EPA Science Inventory

    The phenolic antioxidants are important commercial organic chemicals. Their environmental fate is of significance because of their abundance and usage patterns. This paper reports on the fates of 2,6-di-tert-butylphenol and the methyl and octadecyl esters of 3-(3,5-di-tert-butyl-...

  3. Significance of melatonin in antioxidative defense system: reactions and products.

    PubMed

    Tan, D X; Manchester, L C; Reiter, R J; Qi, W B; Karbownik, M; Calvo, J R

    2000-01-01

    Melatonin is a potent endogenous free radical scavenger, actions that are independent of its many receptor-mediated effects. In the last several years, hundreds of publications have confirmed that melatonin is a broad-spectrum antioxidant. Melatonin has been reported to scavenge hydrogen peroxide (H(2)O(2)), hydroxyl radical (HO(.)), nitric oxide (NO(.)), peroxynitrite anion (ONOO(-)), hypochlorous acid (HOCl), singlet oxygen ((1)O(2)), superoxide anion (O(2)(-).) and peroxyl radical (LOO(.)), although the validity of its ability to scavenge O(2)(-). and LOO(.) is debatable. Regardless of the radicals scavenged, melatonin prevents oxidative damage at the level of cells, tissues, organs and organisms. The antioxidative mechanisms of melatonin seem different from classical antioxidants such as vitamin C, vitamin E and glutathione. As electron donors, classical antioxidants undergo redox cycling; thus, they have the potential to promote oxidation as well as prevent it. Melatonin, as an electron-rich molecule, may interact with free radicals via an additive reaction to form several stable end-products which are excreted in the urine. Melatonin does not undergo redox cycling and, thus, does not promote oxidation as shown under a variety of experimental conditions. From this point of view, melatonin can be considered a suicidal or terminal antioxidant which distinguishes it from the opportunistic antioxidants. Interestingly, the ability of melatonin to scavenge free radicals is not in a ratio of mole to mole. Indeed, one melatonin molecule scavenges two HO. Also, its secondary and tertiary metabolites, for example, N(1)-acetyl-N(2)-formyl-5-methoxykynuramine, N-acetyl-5-methoxykynuramine and 6-hydroxymelatonin, which are believed to be generated when melatonin interacts with free radicals, are also regarded as effective free radical scavengers. The continuous free radical scavenging potential of the original molecule (melatonin) and its metabolites may be defined as a

  4. In Defence of the Lecture

    ERIC Educational Resources Information Center

    Webster, R. Scott

    2015-01-01

    In response to the lecture format coming under "attack" and being replaced by online materials and smaller tutorials, this paper attempts to offer not only a defence but also to assert that the potential value of the lecture is difficult to replicate through other learning formats. Some of the criticisms against lectures will be…

  5. Polyphenol Stilbenes: Molecular Mechanisms of Defence against Oxidative Stress and Aging-Related Diseases

    PubMed Central

    Reinisalo, Mika; Kårlund, Anna; Koskela, Ali; Kaarniranta, Kai; Karjalainen, Reijo O.

    2015-01-01

    Numerous studies have highlighted the key roles of oxidative stress and inflammation in aging-related diseases such as obesity, type 2 diabetes, age-related macular degeneration (AMD), and Alzheimer's disease (AD). In aging cells, the natural antioxidant capacity decreases and the overall efficiency of reparative systems against cell damage becomes impaired. There is convincing data that stilbene compounds, a diverse group of natural defence phenolics, abundant in grapes, berries, and conifer bark waste, may confer a protective effect against aging-related diseases. This review highlights recent data helping to clarify the molecular mechanisms involved in the stilbene-mediated protection against oxidative stress. The impact of stilbenes on the nuclear factor-erythroid-2-related factor-2 (Nrf2) mediated cellular defence against oxidative stress as well as the potential roles of SQSTM1/p62 protein in Nrf2/Keap1 signaling and autophagy will be summarized. The therapeutic potential of stilbene compounds against the most common aging-related diseases is discussed. PMID:26180583

  6. Polyphenol Stilbenes: Molecular Mechanisms of Defence against Oxidative Stress and Aging-Related Diseases.

    PubMed

    Reinisalo, Mika; Kårlund, Anna; Koskela, Ali; Kaarniranta, Kai; Karjalainen, Reijo O

    2015-01-01

    Numerous studies have highlighted the key roles of oxidative stress and inflammation in aging-related diseases such as obesity, type 2 diabetes, age-related macular degeneration (AMD), and Alzheimer's disease (AD). In aging cells, the natural antioxidant capacity decreases and the overall efficiency of reparative systems against cell damage becomes impaired. There is convincing data that stilbene compounds, a diverse group of natural defence phenolics, abundant in grapes, berries, and conifer bark waste, may confer a protective effect against aging-related diseases. This review highlights recent data helping to clarify the molecular mechanisms involved in the stilbene-mediated protection against oxidative stress. The impact of stilbenes on the nuclear factor-erythroid-2-related factor-2 (Nrf2) mediated cellular defence against oxidative stress as well as the potential roles of SQSTM1/p62 protein in Nrf2/Keap1 signaling and autophagy will be summarized. The therapeutic potential of stilbene compounds against the most common aging-related diseases is discussed. PMID:26180583

  7. Antioxidant system responses in two co-occurring green-tide algae under stress conditions

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Zhao, Xinyu; Tang, Xuexi

    2016-01-01

    Green tides have occurred every year from 2007 to 2014 in the Yellow Sea. Ulva prolifera (Müller) J. Agardh has been identified as the bloom-forming alga, co-occurring with U. intestinalis. We observed distinct strategies for both algal species during green tides. U. prolifera exhibited a high abundance initially and then decreased dramatically, while U. intestinalis persisted throughout. The antioxidant system responses of these two macroalgae were compared in the late phase of a green tide (in-situ) and after laboratory acclimation. Lipid peroxidation and antioxidant system responses differed significantly between the two. Malondialdehyde and hydrogen peroxide contents increased significantly in-situ in U. prolifera, but not in U. intestinalis. In U. prolifera, we observed a significant decrease in total antioxidant ability (T-AOC), antioxidant enzymes (SOD and Apx), and non-enzyme antioxidants (GSH and AsA) in-situ. U. intestinalis showed the same pattern of T-AOC and SOD, but its Gpx, Apx, and GSH responses did not differ significantly. The results suggest that U. prolifera was more susceptible than U. intestinalis to the harsh environmental changes during the late phase of a Yellow Sea green tide. The boom and bust strategy exhibited by U. prolifera and the persistence of U. intestinalis can be explained by differences in enzyme activity and antioxidant systems.

  8. Iron homeostasis in host defence and inflammation

    PubMed Central

    Ganz, Tomas; Nemeth, Elizabeta

    2016-01-01

    Iron is an essential trace element for multicellular organisms and nearly all microorganisms. Although iron is abundant in the environment, common forms of iron are minimally soluble and therefore poorly accessible to biological organisms. Microorganisms entering a mammalian host face multiple mechanisms that further restrict their ability to obtain iron and thereby limit their pathogenicity. Iron levels also modulate host defence, as iron content in macrophages regulates their cytokine production. Here, we review recent advances that highlight the role of systemic and cellular iron-regulating mechanisms in protecting hosts from infection, emphasizing aspects that are applicable to human health and disease. PMID:26160612

  9. Antioxidative Properties of Stearoyl Ascorbate in a Food Matrix System.

    PubMed

    Wiboonsirikul, Jintana; Watanabe, Yoshiyuki; Omori, Ayako; Khuwijitjaru, Pramote; Adachi, Shuji

    2016-06-01

    Stearoyl ascorbate or 6-O-stearoyl l-ascorbate is a lipophilic derivative of l-ascorbic acid and is commercially used in foods as a fat-soluble antioxidant and surfactant to overcome the disadvantages of using l-ascorbic acid. The objective of this research is to evaluate the antioxidative ability of stearoyl ascorbate, in the presence of wheat starch or gluten as a matrix, by measuring the unoxidized methyl linoleate available in the mixture of them after oxidation under accelerated conditions compared to that when using ascorbic acid. We observed that stearoyl ascorbate and ascorbic acid exhibited mutually adjacent antioxidative ability against oxidation of the methyl linoleate at a molar ratio of 0.0001 in presence of either wheat starch or gluten. In addition, the oxidation process in the mixture containing either stearoyl ascorbate or ascorbic acid was significantly slower than that in the mixture without stearoyl ascorbate or ascorbic acid. Moreover, by altering the initiation and propagation periods of the oxidation process, the mixture containing the stearoyl ascorbate and gluten as the matrix exhibited conspicuously slower oxidation than the mixture containing either the wheat starch or stearoyl ascorbate alone. However, increase in the ratio of stearoyl ascorbate to methyl linoleate to 0.001 or higher resulted in adverse effects due to acceleration of the oxidation process. PMID:27181253

  10. Oxygen stress: impact on innate immune system, antioxidant defence system and expression of HIF-1α and ATPase 6 genes in Catla catla.

    PubMed

    Singh, Samar Pal; Sharma, JaiGopal; Ahmad, Tauqueer; Chakrabarti, Rina

    2016-04-01

    Catla catla catla (2.28 ± 0.1 g) were exposed to six different levels of dissolved oxygen: 1 (DO-1), 3 (DO-3), 5 (DO-5), 7 (DO-7), 9 (DO-9) and 11 (DO-11) mg/L. DO-5 served as control. In DO-1 and DO-3, the number of red blood cells (RBC), lysozyme, respiratory burst activity and nitric oxide synthase were significantly (p < 0.05) lower compared to the control one. In DO-7 and DO-9, RBC and lysozyme were significantly (p < 0.05) higher compared to the control one. Thiobarbituric acid reactive substances was significantly (p < 0.05) higher in catla exposed at low (1 and 3 mg/L) and high (9 and 11 mg/L) dissolved oxygen compared to others. In muscles and hepatopancreas, reduced glutathione was significantly (p < 0.05) higher in DO-5 and DO-7 and in gills of DO-5 compared to others after 1 h. In muscles, glutathione S-transferase (GST) was significantly (p < 0.05) lower in DO-5 and DO-7 compared to others. In hepatopancreas, GST and glutathione peroxidise (GPx) were significantly (p < 0.05) higher in DO-1 and DO-3 compared to others. In gills, GPx was higher in DO-9 and DO-11 after 48 h. In brain, hypoxia-inducible factor (HIF)-1α mRNA level was induced in DO-1 and DO-3 compared to others after 1 h of exposure. In gills and hepatopancreas, HIF-1α mRNA level was significantly (p < 0.05) higher in DO-1 compared to others after 1 h. The ATPase 6 mRNA level was significantly (p < 0.05) higher in brain and hepatopancreas of DO-1 after 1 h and in gills and hepatopancreas of DO-3 and DO-9, respectively, after 48 h compared to others. PMID:26588934

  11. The Forum for Defence of the Brazilian Unified Health System (Sistema Único de Saúde) and its role in building community participation in the fight against the privatization of health.

    PubMed

    de Lara, Lutiane; Guareschi, Neuza Maria de Fátima

    2016-03-01

    Based on a Foucauldian framework, this article discusses the involvement of the Forum for Defence of the Sistema Único de Saúde in the fight against health care privatization. Community participation is a locus of experience that produces subjects implicated in the production of public health care. The locus of experience in this instance derives from the rejection of private elements that historically have been part of Brazilian public policies. It is an experience that produces workers and service users as agents able to defend the public system and endowed with instituting power. PMID:26987838

  12. Effects of the antioxidant Pycnogenol on cellular redox systems in U1285 human lung carcinoma cells.

    PubMed

    Gandin, Valentina; Nyström, Christina; Rundlöf, Anna-Klara; Jönsson-Videsäter, Kerstin; Schönlau, Frank; Hörkkö, Jarmo; Björnstedt, Mikael; Fernandes, Aristi P

    2009-01-01

    Pycnogenol, which is extracted from the bark of French maritime pine, has been shown to have antioxidant and free radical scavenging activities. Thioredoxin reductase (TrxR), glutathione peroxidase (GPx) and glutathione reductase (GR) are three central redox enzymes that are active in endogenous defence against oxidative stress in the cell. Treatment of cells with Pycnogenol decreased the activity of both TrxR and GPx in cells by more than 50%, but GR was not affected. As previously reported, both enzymes were induced after treatment with hydrogen peroxide and selenite. The presence of Pycnogenol efficiently decreased selenite-mediated reactive oxygen species (ROS) production. Addition of Pycnogenol after selenite treatment reduced the mRNA expression and activity of TrxR to basal levels. In contrast, the GPx activity was completely unaffected. The discrepancy between TrxR and GPx regulation may indicate that transcription of TrxR is induced primarily by oxidative stress. As TrxR is induced in various pathological conditions, including tumours and inflammatory conditions, decreased activity mediated by a non-toxic agent such as Pycnogenol may be of great value. PMID:19077163

  13. Human erythrocytes as a system for evaluating the antioxidant capacity of vegetable extracts.

    PubMed

    Arbos, Kettelin A; Claro, Ligia M; Borges, Lucielly; Santos, Cid A M; Weffort-Santos, Almeriane M

    2008-07-01

    Free radicals are fairly unstable and highly reactive substances, able of causing oxidation and sometimes-irreversible damage to cells, compromising their function. The Brassicaceae family has many important species for the regular human diet as they provide several antioxidant constituents. In this study, the antioxidant potential of the hydroethanolic extracts prepared from the edible parts of kale, broccoli, and radish was investigated in vitro using human erythrocytes under oxidative stress imposed by phenylhydrazine as an experimental model, in which the methemoglobin levels were measured. When the results were compared with the antioxidant capacity shown by the traditional 2,2-diphenyl-2-picrylhydrazyl hydrate free radical and phosphomolybdenum complex methods, the extracts tested showed significant and correspondent antioxidant activity. Broccoli extract presented the highest antioxidant activity, followed closely by the kale, whereas the radish extract occupied the lowest position. The results derived from the human erythrocyte system have shown it as an alternative method for evaluating the antioxidant properties of vegetable extracts. PMID:19083446

  14. [Study of antioxidant and membrane activity of rosmarinic acid using different model systems].

    PubMed

    Popov, A M; Osipov, A N; Korepanova, E A; Krivoshapko, O N; Artiukov, A A

    2013-01-01

    Rosmarinic acid is found in many species of different families of higher plants and its chemical structure is phenol propanoid with various biological activity. In this paper, we conducted a comparative study of antioxidant (radical-scavenging) properties of rosmarinic acid in systems of 2,2'-azo-bis(2-methylpropionamidin)dihydrochloride-luminol and hemoglobin-hydrogen peroxide-lu- minol, determined its protective potential in preventing peroxidation of linoleic acid, and evaluated the effect on the permeability of planar bilayer lipid membranes. Linoleic acid peroxidation was assessed by iron-thiocyanate method. In these studies, trolox was used as a reference antioxidant, and ascorbic acid, and dihydroquercetin were taken as standards. Rosmarinic acid is significantly superior to trolox, ascorbic acid and dihydroquercetin in the tests for antioxidant activity in the systems studied, as well as in inhibition of linoleic acid peroxidation. According to their activity the investigated substances can be arranged in the following order: rosmarinic acid > dihydroquercetin trolox > ascorbic acid. Rosmarinic acid does not cause significant changes in the permeability of planar bilayer membranes in a dose range of 0.5 to 10 mkg/mL. Antioxidant activity of rosmarinic acid is due to the neutralization of reactive oxygen species and/or luminol radicals generated in model systems. The observed features of the antioxidant and membrane activity of rosmarinic acid, which may underlie the previously mentioned pharmacological effects are discussed. PMID:25481945

  15. [Study of antioxidant and membrane activity of rosmarinic acid using different model systems].

    PubMed

    2013-01-01

    Rosmarinic acid is found in many species of different families of higher plants and its chemical structure is phenol propanoid with various biological activity. In this paper, we conducted a comparative study of antioxidant (radical-scavenging) properties of rosmarinic acid in systems of 2,2'-azo-bis(2-methylpropionamidin)dihydrochloride-luminol and hemoglobin-hydrogen peroxide-lu- minol, determined its protective potential in preventing peroxidation of linoleic acid, and evaluated the effect on the permeability of planar bilayer lipid membranes. Linoleic acid peroxidation was assessed by iron-thiocyanate method. In these studies, trolox was used as a reference antioxidant, and ascorbic acid, and dihydroquercetin were taken as standards. Rosmarinic acid is significantly superior to trolox, ascorbic acid and dihydroquercetin in the tests for antioxidant activity in the systems studied, as well as in inhibition of linoleic acid peroxidation. According to their activity the investigated substances can be arranged in the following order: rosmarinic acid > dihydroquercetin trolox > ascorbic acid. Rosmarinic acid does not cause significant changes in the permeability of planar bilayer membranes in a dose range of 0.5 to 10 mkg/mL. Antioxidant activity of rosmarinic acid is due to the neutralization of reactive oxygen species and/or luminol radicals generated in model systems. The observed features of the antioxidant and membrane activity of rosmarinic acid, which may underlie the previously mentioned pharmacological effects are discussed. PMID:25508797

  16. Nitric oxide mediates isoflavone accumulation and the antioxidant system enhancement in soybean sprouts.

    PubMed

    Jiao, Caifeng; Yang, Runqiang; Zhou, Yulin; Gu, Zhenxin

    2016-08-01

    In this study, we investigated the relationships between endogenous NO signal transduction pathways, the antioxidant system and isoflavone accumulation induced by UV-B radiation in soybean sprouts. Results showed that UV-B-triggered NO generation induced isoflavone accumulation by up-regulating the activity and gene expression of key enzymes (phenylalanine ammonia lyase, PAL; chalcone isomerase, CHI; chalcone synthase, CHS; isoflavone synthase, IFS) that participate in isoflavone biosynthesis and enhanced the antioxidant system by regulating levels of antioxidants (glutathione reductase, GR; glutathione S-transferase, GST; ascorbate peroxidase, APX; glutathione GSH; ascorbic acid, ASC), antioxidant enzyme activities (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT) and their gene expression. These effects were inhibited by the addition of a specific NO-scavenger, carboxy-PTIO (cPTIO). The inhibition was reversed through application of the exogenous NO donor, SNP. Overall, NO is an essential signaling molecule, mediating UV-B-induced isoflavone accumulation and the antioxidant system enhancement in soybean sprouts. PMID:26988515

  17. Impact of the age of Biomphalaria alexandrina snails on Schistosoma mansoni transmission: modulation of the genetic outcome and the internal defence system of the snail

    PubMed Central

    Abou-El-Naga, Iman Fathy; Sadaka, Hayam Abd El-Monem; Amer, Eglal Ibrahim; Diab, Iman Hassan; Khedr, Safaa Ibrahim Abd El-Halim

    2015-01-01

    Of the approximately 34 identified Biomphalaria species,Biomphalaria alexandrina represents the intermediate host of Schistosoma mansoni in Egypt. Using parasitological and SOD1 enzyme assay, this study aimed to elucidate the impact of the age of B. alexandrina snails on their genetic variability and internal defence against S. mansoni infection. Susceptible and resistant snails were reared individually for self-reproduction; four subgroups of their progeny were used in experiment. The young susceptible subgroup showed the highest infection rate, the shortest pre-patent period, the highest total cercarial production, the highest mortality rate and the lowest SOD1 activity. Among the young and adult susceptible subgroups, 8% and 26% were found to be resistant, indicating the inheritance of resistance alleles from parents. The adult resistant subgroup, however, contained only resistant snails and showed the highest enzyme activity. The complex interaction between snail age, genetic background and internal defence resulted in great variability in compatibility patterns, with the highest significant difference between young susceptible and adult resistant snails. The results demonstrate that resistance alleles function to a greater degree in adults, with higher SOD1 activity and provide potential implications for Biomphalaria control. The identification of the most susceptible snail age enables determination of the best timing for applying molluscicides. Moreover, adult resistant snails could be beneficial in biological snail control. PMID:26061235

  18. Self-Assembly of Multi-nanozymes to Mimic an Intracellular Antioxidant Defense System.

    PubMed

    Huang, Yanyan; Liu, Zhen; Liu, Chaoqun; Ju, Enguo; Zhang, Yan; Ren, Jinsong; Qu, Xiaogang

    2016-06-01

    In this work, for the first time, we constructed a novel multi-nanozymes cooperative platform to mimic intracellular antioxidant enzyme-based defense system. V2 O5 nanowire served as a glutathione peroxidase (GPx) mimic while MnO2 nanoparticle was used to mimic superoxide dismutase (SOD) and catalase (CAT). Dopamine was used as a linker to achieve the assembling of the nanomaterials. The obtained V2 O5 @pDA@MnO2 nanocomposite could serve as one multi-nanozyme model to mimic intracellular antioxidant enzyme-based defense procedure in which, for example SOD, CAT, and GPx co-participate. In addition, through assembling with dopamine, the hybrid nanocomposites provided synergistic antioxidative effect. Importantly, both in vitro and in vivo experiments demonstrated that our biocompatible system exhibited excellent intracellular reactive oxygen species (ROS) removal ability to protect cell components against oxidative stress, showing its potential application in inflammation therapy. PMID:27098681

  19. Effect of two monoterpene phenols on antioxidant defense system in Candida albicans.

    PubMed

    Khan, Amber; Ahmad, Aijaz; Ahmad Khan, Luqman; Padoa, Carolyn J; van Vuuren, Sandy; Manzoor, Nikhat

    2015-03-01

    Thymol and carvacrol from the class of monoterpene phenols are one of the most potent plant essential oil components possessing antimicrobial effects. Known for their wide bioactive spectrum, these positional isomers of isopropyl cresol deplete ergosterol content, compromise membrane permeability, block efflux pumps and restore antifungal susceptibility to fluconazole in resistant Candida strains. Exposure to these natural compounds induces a cascade of stress responses, which are important to comprehend their microbicidal mechanisms. This study evaluates the antioxidant defense response to lower concentrations of thymol and carvacrol in Candida albicans. The antioxidant defense responses in C. albicans are important for developmental mechanisms pertaining to resistance against the immune system, infection establishment and drug resistance. In this view, primary and secondary antioxidant defense enzymes, and oxidative stress markers including glutathione and lipid peroxidation were determined in C. albicans cells exposed to lower concentrations of thymol and carvacrol. These compounds were found to induce oxidative stress and compromised the antioxidant defense system in C. albicans at lower concentrations. This study helps in understanding the 'in cell' antifungal mechanisms of natural monoterpene phenols originating from oxidative stress. Thymol and carvacrol induced membrane deterioration reported earlier, is further explained as a result of a toxic radical cascade mediated by lipid peroxidation. Findings reinforce the observed toxic oxidizing effects of these compounds as a consequence of direct damage to antioxidant components and not to their genetic manipulations. PMID:25681060

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

    PubMed

    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. PMID:26340979

  1. Thymoquinone ameliorates lead-induced suppression of the antioxidant system in rat kidneys

    PubMed Central

    Mabrouk, Aymen; Cheikh, Hassen Ben

    2016-01-01

    Objective Alteration of the antioxidant status in the kidneys may be related to lead (Pb) intoxication. The present study aimed to investigate the possible beneficial effect of thymoquinone (TQ), the major active ingredient of the volatile oil of Nigella sativa seeds, on Pb-induced renal antioxidant defense system impairment. Methods A total of thirty two healthy adult male Wistar rats were randomly divided into four equal groups as follows: a control group, which received no treatment; a Pb group, which was exposed to 2,000 ppm of Pb acetate in drinking water; a Pb-TQ group, which was cotreated with Pb plus TQ (5 mg/kg/day, per os); and a TQ group receiving only TQ. All treatments were applied for five weeks. Results TQ alone did not induce any significant changes in the antioxidant defense system. By contrast, Pb exposure significantly decreased reduced glutathione level and superoxide dismutase, glutathione peroxidase, catalase, and glutathione reductase activities in the renal tissue. Interestingly, supplementation with TQ significantly improved the affected antioxidant parameters. Conclusion Our data are the first to provide evidence on the protective effect of TQ against Pb-induced renal antioxidant capacity impairment and suggest that this component might be a clinically promising alternative in Pb nephrotoxicity. PMID:27052350

  2. Lipoamide Acts as an Indirect Antioxidant by Simultaneously Stimulating Mitochondrial Biogenesis and Phase II Antioxidant Enzyme Systems in ARPE-19 Cells.

    PubMed

    Zhao, Lin; Liu, Zhongbo; Jia, Haiqun; Feng, Zhihui; Liu, Jiankang; Li, Xuesen

    2015-01-01

    In our previous study, we found that pretreatment with lipoamide (LM) more effectively than alpha-lipoic acid (LA) protected retinal pigment epithelial (RPE) cells from the acrolein-induced damage. However, the reasons and mechanisms for the greater effect of LM than LA are unclear. We hypothesize that LM, rather than the more direct antioxidant LA, may act more as an indirect antioxidant. In the present study, we treated ARPE-19 cells with LA and LM and compared their effects on activation of mitochondrial biogenesis and induction of phase II enzyme systems. It is found that LM is more effective than LA on increasing mitochondrial biogenesis and inducing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its translocation to the nucleus, leading to an increase in expression or activity of phase II antioxidant enzymes (NQO-1, GST, GCL, catalase and Cu/Zn SOD). Further study demonstrated that mitochondrial biogenesis and phase II enzyme induction are closely coupled via energy requirements. These results suggest that LM, compared with the direct antioxidant LA, plays its protective effect on oxidative damage more as an indirect antioxidant to simultaneously stimulate mitochondrial biogenesis and induction of phase II antioxidant enzymes. PMID:26030919

  3. Lipoamide Acts as an Indirect Antioxidant by Simultaneously Stimulating Mitochondrial Biogenesis and Phase II Antioxidant Enzyme Systems in ARPE-19 Cells

    PubMed Central

    Zhao, Lin; Liu, Zhongbo; Jia, Haiqun; Feng, Zhihui; Liu, Jiankang; Li, Xuesen

    2015-01-01

    In our previous study, we found that pretreatment with lipoamide (LM) more effectively than alpha-lipoic acid (LA) protected retinal pigment epithelial (RPE) cells from the acrolein-induced damage. However, the reasons and mechanisms for the greater effect of LM than LA are unclear. We hypothesize that LM, rather than the more direct antioxidant LA, may act more as an indirect antioxidant. In the present study, we treated ARPE-19 cells with LA and LM and compared their effects on activation of mitochondrial biogenesis and induction of phase II enzyme systems. It is found that LM is more effective than LA on increasing mitochondrial biogenesis and inducing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its translocation to the nucleus, leading to an increase in expression or activity of phase II antioxidant enzymes (NQO-1, GST, GCL, catalase and Cu/Zn SOD). Further study demonstrated that mitochondrial biogenesis and phase II enzyme induction are closely coupled via energy requirements. These results suggest that LM, compared with the direct antioxidant LA, plays its protective effect on oxidative damage more as an indirect antioxidant to simultaneously stimulate mitochondrial biogenesis and induction of phase II antioxidant enzymes. PMID:26030919

  4. Midkine in host defence

    PubMed Central

    Gela, A; Jovic, S; Nordin, S L; Egesten, A

    2014-01-01

    Midkine (MK) shares several features in common with antibacterial proteins of the innate immune system. These include growth factor properties, heparin-binding regions and effects on immune cells, such as recruitment and activation of neutrophils and macrophages. Indeed, recent research has demonstrated potent bactericidal and fungicidal activities of MK. This protein is constitutively expressed at relevant concentrations at barriers of the body, such as the skin and the large airways, where the body first encounters potential pathogens. The antibacterial properties of MK orthologues are preserved during evolution, as exemplified by miple2 of Drosophila. In addition to retinoic acid, promoters of MK gene expression include factors present at sites of infection, reactive oxygen species, activation of the transcription factor NF-κB and hypoxia. In the light of the development of resistance in pathogenic bacteria to conventional antibiotics, MK is an interesting molecule that could serve as a template in developing novel therapeutic strategies against bacterial and fungal infections, either alone or in combination with conventional antibiotics. Linked Articles This article is part of a themed section on Midkine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-4 PMID:24024937

  5. Review: Free radicals, antioxidants, and the immune system.

    PubMed

    Knight, J A

    2000-04-01

    Oxygen-derived free radicals are important in both natural and acquired immunity. Neutrophil and macrophage phagocytosis stimulates various cellular processes including the "respiratory burst" whereby increased cellular oxygen uptake results in the production of the potent oxidant bactericidal agents, hypochlorous acid and hydroxyl radical. In addition, nitric oxide, a gaseous radical produced by macrophages, reacts with superoxide to form peroxynitrite, also a potent bactericidal agent. Conversely, oxidative stress may be detrimental in acquired immunity by activation of nuclear factor kappa B, which governs gene expression involving various cytokines, chemokines, and cell adhesion molecules, among others. However, antioxidant supplementation essentially reverses several age-associated immune deficiencies, resulting in increased levels of interleukin-2, elevated numbers of total lymphocytes and T-cell subsets, enhanced mitogen responsiveness, increased killer cell activity, augmented antibody response to antigen stimulation, decreased lipid peroxidation, and decreased prostaglandin synthesis. PMID:10807157

  6. Systemic antioxidant properties of L-carnitine in two different models of arterial hypertension.

    PubMed

    Mate, Alfonso; Miguel-Carrasco, José L; Monserrat, María T; Vázquez, Carmen M

    2010-06-01

    In spite of a wide range of drugs being available in the market, treatment of arterial hypertension still remains a challenge, and new therapeutic strategies could be developed in order to improve the rate of success in controlling this disease. Since oxidative stress has gained importance in the last few years as one of the mechanisms involved in the origin and development of hypertension, and considering that L-carnitine (LC) is a useful compound in different pathologies characterized by increased oxidative status, the aim of the present study was to investigate the systemic antioxidant effect of LC and its correlation to blood pressure in two experimental models of hypertension: (1) spontaneously hypertensive rats (SHR) and (2) rats with hypertension induced by N(omega)-nitro-L-arginine methyl ester (L-NAME). Treatment with captopril was also performed in SHR in order to compare the antioxidant and antihypertensive effects of LC and captopril. The antioxidant defense capacity, in terms of antioxidant enzyme activity, glutathione system availability and plasma total antioxidant capacity, was measured in both animal models with or without an oral, chronic treatment with LC. All the antioxidant parameters studied were diminished in SHR and in L-NAME-treated animals, an alteration that was in general reversed after treatments with LC and captopril. In addition, LC produced a significant but not complete reduction of systolic and diastolic blood pressure levels in these two models of hypertension, whereas captopril was able to normalize blood pressure. Both LC and captopril prevented the reduction in nitric oxide (NO) levels observed in hypertensive animals. This suggests a decrease in the systemic oxidative stress and a higher availability of NO induced by LC in a similar way to captopril's effects, which could be relevant in the management of arterial hypertension eventually. PMID:20506010

  7. [Responses of antioxidation system of Cynodon dactylon to recirculated landfill leachate irrigation].

    PubMed

    Wang, Ruyi; He, Pinjing; Shao, Liming; Zhang, Bin; Li, Guojian

    2005-05-01

    With pot experiment, this paper studied the membrane lipid peroxidation and the variations of antioxidation system in Cynodon dactylon under recirculated landfill leachate irrigation. The results showed that when irrigated with low dilution ratio (< 25%) leachate, the chlorophyll a/b ratio increased with increasing dilution ratio, membrane permeability and MDA and H2O2 contents were in adverse, and membrane lipid peroxidation was relatively weak. However, with the increasing leachate dilution ratio (> 25%), there existed an obvious negative fect on Cynodon dactylon, i.e., the chlorophyll a/b ratio decreased, while cell membrane permeability and MDA and H2O2 contents increased, which meant that the membrane lipid peroxidation was accelerated. The contents antioxidants AsA, GSH and Car also showed the similar trend, i.e., they increased with increasing leachate dilution ratio when irrigated with low dilution ratio leachate, but decreased under medium or high dilution ratio leachate irrigation. Among three test anti-oxidative enzymes, SOD and POD activities showed a similar change test antioxidants, and POD activity was more sensitive, while CAT activity was on the contrary. The contents test antioxidants and the activities of SOD and POD were negatively and significantly correlated to MDA content, indicating that they might play an important role in preventing Cynodon dactylon from cell membrane lipid peroxdation. PMID:16110675

  8. Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5

    PubMed Central

    Saenen, Eline; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Biermans, Geert; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-01-01

    To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed. PMID:26042463

  9. Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5.

    PubMed

    Saenen, Eline; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Biermans, Geert; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-01-01

    To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed. PMID:26042463

  10. Tetraploidization of diploid Dioscorea results in activation of the antioxidant defense system and increased heat tolerance.

    PubMed

    Zhang, Xiao-Yi; Hu, Chun-Gen; Yao, Jia-Ling

    2010-01-15

    Polyploidy is reported to show increased tolerance to environmental stress. In this work, tetraploid plants of Dioscorea zingiberensis were obtained by colchicine treatment of shoots propagated in vitro. The highest tetraploid induction rate was achieved by treatment with 0.15% colchicine for 24h. Diploid and tetraploid plants were exposed to normal (28 degrees C) and high temperature (42 degrees C) for 5d during which physiological indices were measured. Compared with diploid plants, relative electrolyte leakage and contents of malondialdehyde, superoxide anions and hydrogen peroxide were lower in tetraploids, while activities of antioxidant enzymes, such as superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and glutathione reductase, were stimulated and antioxidants (ascorbic acid and glutathione) were maintained at high concentrations. These results indicate that tetraploid plants possess a stronger antioxidant defense system and increased heat tolerance. PMID:19692145

  11. Effect of Putrescine Treatment on Chilling Injury, Fatty Acid Composition and Antioxidant System in Kiwifruit.

    PubMed

    Yang, Qingzhen; Wang, Feng; Rao, Jingping

    2016-01-01

    We investigated the effects of different concentrations (0, 1, 2 and 4 mM) of putrescine on chilling injury, fruit quality, ethylene production rate, fatty acid composition and the antioxidant system of cold-stored kiwifruit (Actinidia chinensis Planch. var. chinensis 'Hongyang'). We achieved a significant decrease in ethylene production, maintained fruit quality and alleviated chilling injury during storage via treatment with 2 mM putrescine. Furthermore, putrescine treatment inhibited increases in superoxide anion production rate and H2O2 concentration, while maintaining higher membrane lipid unsaturation as well as increased activities of superoxide dismutase and catalase. In addition, putrescine treatment enhanced the activities of antioxidant enzymes related to the ascorbate-glutathione cycle while causing higher levels of ascorbic acid and reduced glutathione. Our results suggest that induced tolerance against chilling injury via putrescine treatment in cold-stored kiwifruit may be due to enhanced antioxidant activity, increased unsaturation of membrane lipids, and inhibited ethylene production. PMID:27607076

  12. Phragmites australis and Quercus robur leaf extracts affect antioxidative system and photosynthesis of Ceratophyllum demersum.

    PubMed

    Kamara, Sheku; Pflugmacher, Stephan

    2007-06-01

    During senescence, leaves are deposited on aquatic bodies and decay under water releasing chemical substances that might exert physiological stress to aquatic organisms. Leaf litter alone contributes 30% of the total dissolved organic carbon (DOC) in streams. We investigated the impact of leaves extract from Phragmites australis and Quercus robur on the antioxidative system and photosynthetic rate of the aquatic macrophyte Ceratophyllum demersum exposed for 24h. Rate of photosynthetic oxygen release and antioxidant enzyme activity (glutathione S-transferases, glutathione reductases and peroxidases) as well as lipid peroxidation in C. demersum were measured. Significant (P<0.01) elevations of antioxidative enzyme activity in C. demersum which tends to plateau at high DOC concentrations were observed. There was no detectable effect on lipid peroxidation. A significant dose-dependent reduction in photosynthetic oxygen production was measured. PMID:16996134

  13. A method to evaluate the antioxidant system for radicals in erythrocyte membranes

    SciTech Connect

    Fung, L.W.; Zhang, Y. )

    1990-01-01

    The erythrocyte defense system against cellular oxidants is complex and efficient. Free radicals generated in cell membranes, however, are relatively sequestered from the cell's antioxidant mechanisms. When an oxidant challenge exceeds the capacity of the erythrocyte's antioxidant system, membrane damage may occur, causing red cell destruction and hemolytic anemia. In this study, we present a method for monitoring radical reduction in erythrocyte membranes, using fatty acid spin labels with nitroxide radicals on the hydrocarbon chains. About 50 microL of packed (about 5-6 x 10(8)), carbon monoxide (CO)-gassed red blood cells are used. The electron paramagnetic resonance signals of the 5-doxylstearic acid spin labels in the intact cells are obtained as a function of time, at 37 degrees C over a period of 2 h. The pseudo first-order rate constant for reduction of the spin label in normal adult intact cells under our experimental conditions is 4.3 +/- 1.8 x 10(-3)/min. The reproducibility and variability of the measurements are discussed. Since the measurements we describe reflect the extent of radical reductions occurring in cell membranes, we suggest that this method can be used to measure the ability to defend oxidants in membranes of erythrocytes with defective antioxidant systems. This method is particularly useful for measuring the modification of the antioxidant system toward radicals in membranes by drugs, chemicals, or environmental toxins.

  14. Dietary antioxidants: immunity and host defense.

    PubMed

    Puertollano, María A; Puertollano, Elena; de Cienfuegos, Gerardo Álvarez; de Pablo, Manuel A

    2011-01-01

    Natural antioxidants may be defined as molecules that prevent cell damage against free radicals and are critical for maintaining optimum health in both animals and humans. In all living systems, cells require adequate levels of antioxidant defenses in order to avoid the harmful effect of an excessive production of reactive oxygen species (ROS) and to prevent damage to the immune cells. During the inflammatory processes, the activation of phagocytes and/or the action of bacterial products with specific receptors are capable of promoting the assembly of the multicomponent flavoprotein NADPH oxidase, which catalyzes the production of high amounts of the superoxide anion radical (O(2)(-)). Under these particular circumstances, neutrophils and macrophages are recognized to produce superoxide free radicals and H(2)O(2), which are essential for defence against phagocytized or invading microbes. In this state, antioxidants are absolutely necessary to regulate the reactions that release free radicals. Antioxidant nutrients commonly included in the diet such as vitamin E, vitamin C, β-carotene, selenium, copper, iron and zinc improve different immune function exhibiting an important protective role in infections caused by bacteria, viruses or parasites. As a result, dietary antioxidants have been related to modulate the host susceptibility or resistance to infectious pathogens. Overall, numerous studies have suggested that the development of tolerance, and control of inflammation are strongly correlated with specific immune mechanisms that may be altered by an inadequate supply of either macronutrients or micronutrients. Therefore, the present paper will review the effects of dietary antioxidants on immune cell function and the impact on protection against infectious microorganisms. PMID:21506934

  15. Natural genetic variation in the expression regulation of the chloroplast antioxidant system among Arabidopsis thaliana accessions.

    PubMed

    Juszczak, Ilona; Rudnik, Radoslaw; Pietzenuk, Björn; Baier, Margarete

    2012-09-01

    Photosynthesis is the predominant source of reactive oxygen species in light. In order to prevent the negative influence of reactive oxygen species (ROS) on cell functionality, chloroplasts have evolved a highly efficient antioxidant protection system. Here, we present the first study on natural variation in this system. Comparison of temperature and developmental responses in seven accessions of Arabidopsis thaliana from northern habitats showed that the regulation is widely genetically manifested, but hardly correlates with geographic parameters. Transcript, polysomal RNA (pRNA) and protein data showed that the ecotypes use different strategies to adjust the chloroplast antioxidative defense system, either by regulating transcript abundance or initiation of translation. Comparison of mRNA and pRNA levels showed that Col-0 invests more into transcript accumulation, while Van-0, WS and C24 regulates the chloroplast antioxidant protection system more on the level of pRNA. Nevertheless, both strategies of regulation led to the expression of chloroplast antioxidant enzymes at sufficient level to efficiently protect plants from ROS accumulation in Col-0, WS, C24 and Van-0. On the contrary, Cvi-0, Ms-0 and Kas-1 accumulated high amounts of ROS. The expression of copper/zinc superoxide dismutase (Csd2), ascorbate peroxidases and 2-Cys peroxiredoxins was higher in Cvi-0 on the transcriptional level, while Csd2, peroxiredoxin Q, type II peroxiredoxin E and glutathione peroxidase 1 were induced in Ms-0 on the mRNA level. Similar to Kas-1, in which mRNA levels were less than or similar to Col-0 gene, specific support for translation was observed in Ms-0, showing that the ecotypes use different strategies to adjust the antioxidant system. PMID:22339086

  16. Defence electro-optics: European perspective

    NASA Astrophysics Data System (ADS)

    Hartikainen, Jari

    2011-11-01

    In 2009 the United States invested in defence R&T 3,6 times and in defence research and development 6,8 times as much as all member states of the European Defence Agency (EDA) combined while the ratio in the total defence expenditure was 2,6 in the US' favour. The European lack of investments in defence research and development has a negative impact on the competitiveness of European defence industry and on the European non-dependence. In addition, the efficiency of investment is reduced due to duplication of work in different member states. The Lisbon Treaty tasks EDA to support defence technology research, and coordinate and plan joint research activities and the study of technical solutions meeting future operational needs. This paper gives an overview how EDA meets the challenge of improving the efficiency of European defence R&T investment with an emphasis on electro-optics and describes shortly the ways that governmental and industrial partners can participate in the EDA cooperation. Examples of joint R&T projects addressing electro-optics are presented.

  17. Plant defences against herbivore and insect attack

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants deploy a number of defences against attack by insects and other herbivores. Direct defence is conferred by plant products and structures that deter or kill the herbivores. Chemical toxins and deterrents vary widely among plant species, and some typical toxins include alkaloids, terpenoids, st...

  18. Simple Growth Patterns Can Create Complex Trajectories for the Ontogeny of Constitutive Chemical Defences in Seaweeds

    PubMed Central

    Paul, Nicholas A.; Svensson, Carl Johan; de Nys, Rocky; Steinberg, Peter D.

    2014-01-01

    All of the theory and most of the data on the ecology and evolution of chemical defences derive from terrestrial plants, which have considerable capacity for internal movement of resources. In contrast, most macroalgae – seaweeds – have no or very limited capacity for resource translocation, meaning that trade-offs between growth and defence, for example, should be localised rather than systemic. This may change the predictions of chemical defence theories for seaweeds. We developed a model that mimicked the simple growth pattern of the red seaweed Asparagopsis armata which is composed of repeating clusters of somatic cells and cells which contain deterrent secondary chemicals (gland cells). To do this we created a distinct growth curve for the somatic cells and another for the gland cells using empirical data. The somatic growth function was linked to the growth function for defence via differential equations modelling, which effectively generated a trade-off between growth and defence as these neighbouring cells develop. By treating growth and defence as separate functions we were also able to model a trade-off in growth of 2–3% under most circumstances. However, we found contrasting evidence for this trade-off in the empirical relationships between growth and defence, depending on the light level under which the alga was cultured. After developing a model that incorporated both branching and cell division rates, we formally demonstrated that positive correlations between growth and defence are predicted in many circumstances and also that allocation costs, if they exist, will be constrained by the intrinsic growth patterns of the seaweed. Growth patterns could therefore explain contrasting evidence for cost of constitutive chemical defence in many studies, highlighting the need to consider the fundamental biology and ontogeny of organisms when assessing the allocation theories for defence. PMID:24497991

  19. Evolution of hosts paying manifold costs of defence

    PubMed Central

    Cressler, Clayton E.; Graham, Andrea L.; Day, Troy

    2015-01-01

    Hosts are expected to incur several physiological costs in defending against parasites. These include constitutive energetic (or other resource) costs of a defence system, facultative resource costs of deploying defences when parasites strike, and immunopathological costs of collateral damage. Here, we investigate the evolution of host recovery rates, varying the source and magnitude of immune costs. In line with previous work, we find that hosts paying facultative resource costs evolve faster recovery rates than hosts paying constitutive costs. However, recovery rate is more sensitive to changes in facultative costs, potentially explaining why constitutive costs are hard to detect empirically. Moreover, we find that immunopathology costs which increase with recovery rate can erode the benefits of defence, promoting chronicity of infection. Immunopathology can also lead to hosts evolving low recovery rate in response to virulent parasites. Furthermore, when immunopathology reduces fecundity as recovery rate increases (e.g. as for T-cell responses to urogenital chlamydiosis), then recovery and reproductive rates do not covary as predicted in eco-immunology. These results suggest that immunopathological and resource costs have qualitatively different effects on host evolution and that embracing the complexity of immune costs may be essential for explaining variability in immune defence in nature. PMID:25740895

  20. New insights into the antioxidant activity of hydroxycinnamic and hydroxybenzoic systems: spectroscopic, electrochemistry, and cellular studies.

    PubMed

    Mura, F; Silva, T; Castro, C; Borges, F; Zuñiga, M C; Morales, J; Olea-Azar, C

    2014-12-01

    A series hydroxycinnamic and gallic acids and their derivatives were studied with the aim of evaluating their in vitro antioxidant properties both in homogeneous and in cellular systems. It was concluded from the oxygen radical absorbance capacity-fluorescein (ORAC-FL), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and cyclic voltammetry data that some compounds exhibit remarkable antioxidant properties. In general, in homogeneous media (DPPH assay), galloyl-based cinnamic and benzoic systems (compounds 7-11) were the most active, exhibiting the lowest oxidation potentials in both dimethyl sulfoxide (DMSO) and phosphate buffer. Yet, p-coumaric acid and its derivatives (compounds 1-3) disclosed the highest scavenging activity toward peroxyl radicals (ORAC-FL assay). Interesting structure-property- activity relationships between ORAC-FL, or DPPH radical, and redox potentials have been attained, showing that the latter parameter can be a valuable antioxidant measure. It was evidenced that redox potentials are related to the structural features of cinnamic and benzoic systems and that their activities are also dependent on the radical generated in the assay. Electron spin resonance data of the phenoxyl radicals generated both in DMSO and phosphate buffer support the assumption that radical stability is related to the type of phenolic system. Galloyl-based cinnamic and benzoic ester-type systems (compounds 9 and 11) were the most active and effective compounds in cell-based assays (51.13 ± 1.27% and 54.90 ± 3.65%, respectively). In cellular systems, hydroxycinnamic and hydroxybenzoic systems operate based on their intrinsic antioxidant outline and lipophilic properties, so the balance between these two properties is considered of the utmost importance to ensure their performance in the prevention or minimization of the effects due to free radical overproduction. PMID:25236566

  1. The relationship between the antioxidant system, oxidative stress and dialysis-related amyloidosis in hemodialysis patients.

    PubMed

    Celik, Gulperi; Capraz, Irfan; Yontem, Mustafa; Bilge, Murat; Unaldi, Mustafa; Mehmetoglu, Idris

    2013-11-01

    End-stage renal disease (ESRD) is associated with several complications that are partly due to excess amounts of reactive oxygen species and/or decreased antioxidant activity. Dialysis-related amyloidosis (DRA) has also been linked to increased oxidative stress. The aim of this study was to investigate the relationships between the antioxidant system, including superoxide dismutase (SOD), malonyldialdehyde (MDA), various biochemical parameters and shoulder amyloidosis, in hemodialysis patients. We studied 107 non-diabetic chronic dialysis patients. The SOD levels correlated with right and left biceps tendon thickness (r = -0.219, P = 0.048 and r = -0.236, P = 0.031, respectively), MDA (r = -0.429, P = 0.000) and albumin levels (r = -0.319, P = 0.001). MDA levels correlated with right and left biceps thickness (r = 0.291, P = 0.006 and r = 0.337, P = 0.001, respectively) and β2 microglobulin levels (r = 0.455, P = 0.000). We also identified the statistically significant relationships between MDA levels and supraspinatus tendon thickening (greater than 7 mm) and right and left biceps tendon thickness (P = 0.022, P = 0.040 and P = 0.005, respectively). Our data suggest the complex relationship between antioxidants and oxidative stress and further support the roles of oxidative stress and antioxidants in DRA. PMID:24231477

  2. Salicylic acid enhances antioxidant system in Brassica juncea grown under different levels of manganese.

    PubMed

    Parashar, Akshaya; Yusuf, Mohammad; Fariduddin, Qazi; Ahmad, Aqil

    2014-09-01

    The aim was to explore the responses of varied doses of manganese in mustard plants and also to test the proposition that salicylic acid induced up-regulation of antioxidant system which protect photosynthetic apparatus. Seeds were sown in pots and allowed to germinate under natural environmental conditions. At 10 days stage, soils in the pots were enriched with different levels (0, 3, 6, or 9 mM) of Mn for three days and allowed to grow till 30 day stage. At 31st day, foliage of plants was sprayed with 10 μM of salicylic acid (SA) and then allowed to grow till 45 days. Then plants were harvested to assess various growth, leaf gas exchange traits and biochemical parameters. Mn-treated plants had diminished growth, water relations and photosynthetic attributes along with carbonic anhydrase activity whereas; the level of lipid peroxidation, electrolyte leakage, accumulation of H2O2 along with proline accumulation and antioxidant enzymes increased in a concentration dependent manner. Follow-up application of SA to the Mn-stressed plants improved growth, water relations and photosynthetic traits, accelerated the activity of antioxidant enzymes and also the accumulation of proline. SA mediated tolerance to Mn-stressed plants could have due to up-regulation of antioxidant enzymes and proline accumulation. PMID:25036598

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

    PubMed

    Sadowska-Bartosz, Izabela; Bartosz, Grzegorz

    2013-12-01

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

  4. Redox Control of Multidrug Resistance and Its Possible Modulation by Antioxidants

    PubMed Central

    Cort, Aysegul; Ozben, Tomris; Saso, Luciano; De Luca, Chiara

    2016-01-01

    Clinical efficacy of anticancer chemotherapies is dramatically hampered by multidrug resistance (MDR) dependent on inherited traits, acquired defence against toxins, and adaptive mechanisms mounting in tumours. There is overwhelming evidence that molecular events leading to MDR are regulated by redox mechanisms. For example, chemotherapeutics which overrun the first obstacle of redox-regulated cellular uptake channels (MDR1, MDR2, and MDR3) induce a concerted action of phase I/II metabolic enzymes with a temporal redox-regulated axis. This results in rapid metabolic transformation and elimination of a toxin. This metabolic axis is tightly interconnected with the inducible Nrf2-linked pathway, a key switch-on mechanism for upregulation of endogenous antioxidant enzymes and detoxifying systems. As a result, chemotherapeutics and cytotoxic by-products of their metabolism (ROS, hydroperoxides, and aldehydes) are inactivated and MDR occurs. On the other hand, tumour cells are capable of mounting an adaptive antioxidant response against ROS produced by chemotherapeutics and host immune cells. The multiple redox-dependent mechanisms involved in MDR prompted suggesting redox-active drugs (antioxidants and prooxidants) or inhibitors of inducible antioxidant defence as a novel approach to diminish MDR. Pitfalls and progress in this direction are discussed. PMID:26881027

  5. Redox Control of Multidrug Resistance and Its Possible Modulation by Antioxidants.

    PubMed

    Cort, Aysegul; Ozben, Tomris; Saso, Luciano; De Luca, Chiara; Korkina, Liudmila

    2016-01-01

    Clinical efficacy of anticancer chemotherapies is dramatically hampered by multidrug resistance (MDR) dependent on inherited traits, acquired defence against toxins, and adaptive mechanisms mounting in tumours. There is overwhelming evidence that molecular events leading to MDR are regulated by redox mechanisms. For example, chemotherapeutics which overrun the first obstacle of redox-regulated cellular uptake channels (MDR1, MDR2, and MDR3) induce a concerted action of phase I/II metabolic enzymes with a temporal redox-regulated axis. This results in rapid metabolic transformation and elimination of a toxin. This metabolic axis is tightly interconnected with the inducible Nrf2-linked pathway, a key switch-on mechanism for upregulation of endogenous antioxidant enzymes and detoxifying systems. As a result, chemotherapeutics and cytotoxic by-products of their metabolism (ROS, hydroperoxides, and aldehydes) are inactivated and MDR occurs. On the other hand, tumour cells are capable of mounting an adaptive antioxidant response against ROS produced by chemotherapeutics and host immune cells. The multiple redox-dependent mechanisms involved in MDR prompted suggesting redox-active drugs (antioxidants and prooxidants) or inhibitors of inducible antioxidant defence as a novel approach to diminish MDR. Pitfalls and progress in this direction are discussed. PMID:26881027

  6. Seasonal variations of melatonin in ram seminal plasma are correlated to those of testosterone and antioxidant enzymes

    PubMed Central

    2010-01-01

    Background Some breeds of sheep are highly seasonal in terms of reproductive capability, and these changes are regulated by photoperiod and melatonin secretion. These changes affect the reproductive performance of rams, impairing semen quality and modifying hormonal profiles. Also, the antioxidant defence systems seem to be modulated by melatonin secretion, and shows seasonal variations. The aim of this study was to investigate the presence of melatonin and testosterone in ram seminal plasma and their variations between the breeding and non-breeding seasons. In addition, we analyzed the possible correlations between these hormones and the antioxidant enzyme defence system activity. Methods Seminal plasma from nine Rasa Aragonesa rams were collected for one year, and their levels of melatonin, testosterone, superoxide dismutase (SOD), glutathione reductase (GRD), glutathione peroxidase (GPX) and catalase (CAT) were measured. Results All samples presented measurable quantities of hormones and antioxidant enzymes. Both hormones showed monthly variations, with a decrease after the winter solstice and a rise after the summer solstice that reached the maximum levels in October-November, and a marked seasonal variation (P < 0.01) with higher levels in the breeding season. The yearly pattern of GRD and catalase was close to that of melatonin, and GRD showed a significant seasonal variation (P < 0.01) with a higher activity during the breeding season. Linear regression analysis between the studied hormones and antioxidant enzymes showed a significant correlation between melatonin and testosterone, GRD, SOD and catalase. Conclusions These results show the presence of melatonin and testosterone in ram seminal plasma, and that both hormones have seasonal variations, and support the idea that seasonal variations of fertility in the ram involve interplay between melatonin and the antioxidant defence system. PMID:20540737

  7. Metabolomic Assessment of Induced and Activated Chemical Defence in the Invasive Red Alga Gracilaria vermiculophylla

    PubMed Central

    Nylund, Göran M.; Weinberger, Florian; Rempt, Martin; Pohnert, Georg

    2011-01-01

    In comparison with terrestrial plants the mechanistic knowledge of chemical defences is poor for marine macroalgae. This restricts our understanding in the chemically mediated interactions that take place between algae and other organisms. Technical advances such as metabolomics, however, enable new approaches towards the characterisation of the chemically mediated interactions of organisms with their environment. We address defence responses in the red alga Gracilaria vermiculophylla using mass spectrometry based metabolomics in combination with bioassays. Being invasive in the north Atlantic this alga is likely to possess chemical defences according to the prediction that well-defended exotics are most likely to become successful invaders in systems dominated by generalist grazers, such as marine macroalgal communities. We investigated the effect of intense herbivore feeding and simulated herbivory by mechanical wounding of the algae. Both processes led to similar changes in the metabolic profile. Feeding experiments with the generalist isopod grazer Idotea baltica showed that mechanical wounding caused a significant increase in grazer resistance. Structure elucidation of the metabolites of which some were up-regulated more than 100 times in the wounded tissue, revealed known and novel eicosanoids as major components. Among these were prostaglandins, hydroxylated fatty acids and arachidonic acid derived conjugated lactones. Bioassays with pure metabolites showed that these eicosanoids are part of the innate defence system of macroalgae, similarly to animal systems. In accordance with an induced defence mechanism application of extracts from wounded tissue caused a significant increase in grazer resistance and the up-regulation of other pathways than in the activated defence. Thus, this study suggests that G. vermiculophylla chemically deters herbivory by two lines of defence, a rapid wound-activated process followed by a slower inducible defence. By unravelling

  8. CULTURAL SYSTEM AFFECTS FRUIT QUALITY AND ANTIOXIDANT CAPACITY IN STRAWBERRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultural system [hill plasticulture (HC) vs. matted row (MR)] and genotypes interactions affected strawberry fruit quality. In general, fruit soluble content, total sugar, fructose, glucose, ascorbic acid, titratable acid and citric acid content were increased in the HC system. Fruit from HC also ...

  9. Characterization of the antioxidant systems in different complementation groups of Dyskeratosis Congenita.

    PubMed

    Ibañez-Cabellos, Jose Santiago; Seco-Cervera, Marta; Perez-Machado, Giselle; Garcia-Gimenez, Jose Luis; Pallardo, Federico V

    2014-10-01

    The telomerase complex and Telosome regulate, maintenance and repair telomeres. The telomerase complex is formed by complex of protein (TERT, Dyskerin, GAR, NHP2, NOP10) and nucleic acid (TERC) that together work as a reverse transcriptase. The Telosoma comprises a network of protein (TRF2, TRF1, TIN2, RAP1, TPP1 and POT1). Furthermore, dyskeratosis congenita (DC) (ORPHA1775) is a rare disease with similar characteristics to premature aging. DC is a genetically heterogeneous disease caused by mutations in the genes that encoding for different subunits of the telomerase complex and Telosome. It is known that the telomeric DNA is susceptible to oxidative stress, and telomerase activity dependent cellular redox environment. Recently a correlation between telomerase activity and catalase activity was established, and it has suggested a role of antioxidant extranuclear telomerase. However, it is not yet clear whether there is any relationship or connection between molecular telomerase activity and cellular antioxidant defense. In this paper, by using the technology of RNA interference (siRNA) silencing DKC1, NOP10 genes of telomerase complex and TINF2 of Telosoma in HeLa cells, on cellular antioxidant capacity will be presented. It was intended to see if there is a cellular effect related to the production of oxidative stress or alteration of antioxidant systems after silencing these components involved in telomere maintenance. In this paper we have evaluated the levels of DKC1, NOP10, TINF2 levels of antioxidant enzymes (CuZnSOD, MnSOD, Catalase, Gpx1, Grx1 and Trx1) by RT- qPCR and Western blotting. We analyzed the production of reactive oxygen species by fluorimetry and also assessed the activity of the telomerase complex by Sybr Green RT- QTrap. PMID:26461348

  10. 3-Pyridinols and 5-pyrimidinols: Tailor-made for use in synergistic radical-trapping co-antioxidant systems

    PubMed Central

    Bartolomei, Daniele; Amorati, Riccardo; Haidasz, Evan; Hanthorn, Jason J; Nara, Susheel J; Brinkhorst, Johan

    2013-01-01

    Summary The incorporation of nitrogen atoms into the aromatic ring of phenolic compounds has enabled the development of some of the most potent radical-trapping antioxidants ever reported. These compounds, 3-pyridinols and 5-pyrimidinols, have stronger O–H bonds than equivalently substituted phenols, but possess similar reactivities toward autoxidation chain-carrying peroxyl radicals. These attributes suggest that 3-pyridinols and 5-pyrimidinols will be particularly effectiveco-antioxidants when used in combination with more common, but less reactive, phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol (BHT), which we demonstrate herein. The antioxidants function in a synergistic manner to inhibit autoxidation; taking advantage of the higher reactivity of the 3-pyridinols/5-pyrimidinols to trap peroxyl radicals and using the less reactive phenols to regenerate them from their corresponding aryloxyl radicals. The present investigations were carried out in chlorobenzene and acetonitrile in order to provide some insight into the medium dependence of the synergism and the results, considered with some from our earlier work, prompt a revision of the H-bonding basicity value of acetonitrile to β2 H of 0.39. Overall, the thermodynamic and kinetic data presented here enable the design of co-antioxidant systems comprising lower loadings of the more expensive 3-pyridinol/5-pyrimidinol antioxidants and higher loadings of the less expensive phenolic antioxidants, but which are equally efficacious as the 3-pyridinol/5-pyrimidinol antioxidants alone at higher loadings. PMID:24367442

  11. [Use of adaptogens for antioxidant system correction in complex treatment of mandibular fractures].

    PubMed

    Ushnitsky, I D; Terenteva, Z V; Kerschengolts, B M; Vinocurov, M M; Voronov, I V; Egorova, L I

    2015-01-01

    Antioxidatic protection has been studied in 84 patients with mandibular fractures between the ages of 21 and 40; the patients were divided into two groups. Activation of lipid peroxidation in both groups was revealed. The increase of antioxidant's activity system in 37.18% in the main study group that along with traditional treatment received Epsorin was determined. No complications in the main group during the post-surgery period were recorded. PMID:26271700

  12. Effect of Cytotoxic Compounds on Activity of Antioxidant Enzyme System in MCF-7 and H1299 Cells.

    PubMed

    Mumyatova, V A; Balakina, A A; Filatova, N V; Sen', V D; Korepin, A G; Terentev, A A

    2016-05-01

    We studied the function of the antioxidant system in tumor cell lines MCF-7 and H1299 that differ by the state of tumor suppressor gene p53. Exposure to different classes of cytotoxic compounds induced several types of antioxidant system responses that depend on the type of cell line. The effects of platinum(II) and platinum(IV) complexes on activity of antioxidant enzymes vary, which can be explained by differences in their accumulation and biotransformation in tumor cells. Triazole and oxazolidinone derivatives had little effect on activity of superoxide dismutase and catalase in H1299 cells, but increased superoxide dismutase activity in MCF-7 cells. PMID:27265137

  13. COMBINED EFFECTS OF CO2 AND O3 ON ANTIOXIDATIVE AND PHOTOPROTECTIVE DEFENSE SYSTEMS IN NEEDLES OF PONDEROSA PINE

    EPA Science Inventory

    To determine interactive effects of important environmental stresses on biochemical defense mechanisms of tree seedlings, we studied responses to elevated O3 and elevated atmospheric CO2 on antioxidative and photoprotective systems in needles of ponderosa pine (Pinus ponderosa Do...

  14. Antioxidant systems and lipid peroxidation in Bathymodiolus azoricus from Mid-Atlantic Ridge hydrothermal vent fields.

    PubMed

    Bebianno, M J; Company, R; Serafim, A; Camus, L; Cosson, R P; Fiala-Médoni, A

    2005-11-30

    Enzymatic defenses involved in protection from oxygen radical damage were determined in gills and mantle of Bathymodiolus azoricus collected from three contrasting Mid-Atlantic Ridge (MAR) hydrothermal vent fields (Menez-Gwen, Lucky Strike and Rainbow). The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and Se-dependent), and levels of total oxyradical scavenging capacity (TOSC), metallothioneins (MT) and lipid peroxidation (LPO) were determined in B. azoricus tissues and the impact of metal concentrations on these antioxidant systems and lipid peroxidation assessed. SOD, CAT, TOSC, MTs and LPO levels were higher in B. azoricus gills while glutathione peroxidases (total and Se-dependent) were higher in the mantle, and with the exception of CAT, were of the same order of magnitude as in other molluscs. TOSC levels from Menez-Gwen indicate that the vent environment at this site is less stressful and the formation of ROS in mussels is effectively counteracted by the antioxidant defense system. TOSC depletion indicates an elevated ROS production in molluscs at the other two vent sites. Cytosolic SOD, GPx and LPO were more relevant at Lucky Strike (Bairro Alto) where levels of essential (Cu and Zn) and toxic metals (Cd and Ag) were highest in the organisms. CAT activity and LPO were predominant at the Rainbow vent site, where an excess of Fe in mussel tissues and in vent fluids (the highest of all three vent sites) may have contributed to increased LPO. Therefore, three distinct pathways for antioxidant enzyme systems and LPO based on environmental metal speciation of MAR vent fields are proposed for Bathymodiolus gills. At Menez-Gwen, TOSC towards peroxyl and hydroxyl radicals and peroxynitrite are predominant, while at Lucky Strike cytosolic SOD activity and GPx are the main antioxidant mechanisms. Finally at Rainbow, catalase and lipid peroxidation are dominant, suggesting that resistance of mussels to metal toxicity at

  15. Predator-induced defences in Daphnia longicephala: location of kairomone receptors and timeline of sensitive phases to trait formation

    PubMed Central

    Weiss, Linda C.; Leimann, Julian; Tollrian, Ralph

    2015-01-01

    ABSTRACT The freshwater crustacean Daphnia adapts to changing predation risks by forming inducible defences. These are only formed when they are advantageous, saving associated costs when the defence is superfluous. However, in order to be effective, the time lag between the onset of predation and the defence formation has to be short. Daphnia longicephala develop huge protective crests upon exposure to chemical cues (kairomones) from its predator the heteropteran backswimmer Notonecta glauca. To analyse time lags, we determined kairomone-sensitive stages and the developmental time frames of inducible defences. Moreover, we looked at additive effects that could result from the summation of prolonged kairomone exposure. Kairomones are perceived by chemoreceptors and integrated by the nervous system, which alters the developmental program leading to defence formation. The underlying neuronal and developmental pathways are not thoroughly described and surprisingly, the location of the kairomone receptors is undetermined. We show that D. longicephala start to sense predator cues at the onset of the second juvenile instar, defences develop with a time lag of one instar and prolonged kairomone exposure does not impact the magnitude of the defence. By establishing a method to reversibly impair chemosensors, we show the first antennae as the location of kairomone-detecting chemoreceptors. This study provides fundamental information on kairomone perception, kairomone-sensitive stages, developmental time frames and lag times of inducible defences in D. longicephala that will greatly contribute to the further understanding of the neuronal and developmental mechanisms of predator-induced defences in Daphnia. PMID:26400980

  16. Effect of cold adaptation on activities of relevant enzymes and antioxidant system in rats

    PubMed Central

    Xing, Ji-Qing; Zhou, Yang; Chen, Jian-Feng; Li, Shang-Bin; Fang, Wei; Yang, Jun

    2014-01-01

    Exercise in cold environments can cause significant metabolic regulation and antioxidant behavior. For discussing enzymatic responses towards cold adaptation, we investigated enzyme activities of adenylate cyclase (AC) and phosphodiesterase (PDE) in liver, skeletal muscle, and brown adipose tissue (BAT), as well as Na+·K+ ATPase and Na+/K+ ratio in blood. Malondialdehyde (MDA) and superoxide dismutase (SOD) activity in blood were also studied to address the effect of cold adaptation on oxidative damage and antioxidant system. Experimental results indicated that enzyme activities in liver, skeletal muscle and BAT maintained relatively constant for the control group. For the cold adaptation group, enzyme activities in liver and skeletal muscle were in high levels at the beginning, and then gradually decreased to similar values with the control group. However, enzyme activities in BAT performed an increasing trend and significantly higher than the control at the end. In addition, decreased oxidative damage and activated antioxidant system was observed along with the cold adaptation process. PMID:25550936

  17. Sexual misbehaviour in the Australian Defence Force.

    PubMed

    Williams, Angela; Ranson, David

    2013-12-01

    It is clear from recent media reporting that serious issues have come to light regarding sexual misbehaviour matters within the Australian Defence Force. Subsequent reviews have indicated that these behaviours appear to have been more widespread than the initial media reports suggested and a number of reviews have been undertaken to better understand the problem and address the concerns of victims, Defence command, government and the community. If these problems are not addressed, there is a risk that recruitment to the Defence Forces may become problematic. The strong command structures within the Defence Forces can both exacerbate these misbehaviours through entrenching secrecy and at the same time have the capacity to provide a powerful leadership message that can change attitudes and reduce such misbehaviours. PMID:24597372

  18. The mechanical defence advantage of small seeds.

    PubMed

    Fricke, Evan C; Wright, S Joseph

    2016-08-01

    Seed size and toughness affect seed predators, and size-dependent investment in mechanical defence could affect relationships between seed size and predation. We tested how seed toughness and mechanical defence traits (tissue density and protective tissue content) are related to seed size among tropical forest species. Absolute toughness increased with seed size. However, smaller seeds had higher specific toughness both within and among species, with the smallest seeds requiring over 2000 times more energy per gram to break than the largest seeds. Investment in mechanical defence traits varied widely but independently of the toughness-mass allometry. Instead, a physical scaling relationship confers a toughness advantage on small seeds independent of selection on defence traits and without a direct cost. This scaling relationship may contribute to seed size diversity by decreasing fitness differences among large and small seeds. Allometric scaling of toughness reconciles predictions and conflicting empirical relationships between seed size and predation. PMID:27324185

  19. Purification and antioxidant properties of bigeye tuna (Thunnus obesus) dark muscle peptide on free radical-mediated oxidative systems.

    PubMed

    Je, Jae-Young; Qian, Zhong-Ji; Lee, Sang-Hoon; Byun, Hee-Guk; Kim, Se-Kwon

    2008-12-01

    To produce bioactive peptides from by-products of fish processing, bigeye tuna dark muscle was hydrolyzed using various enzymes (alcalase, alpha-chymotrypsin, neutrase, papain, pepsin, and trypsin), and the hydrolysates were evaluated for antioxidant activity. Considering the results of degree of hydrolysis and antioxidant activities, peptic hydrolysate was used for further studies to identify a potent antioxidant peptide. Antioxidant peptide was purified using consecutive chromatographic methods and was identified as being H-Leu-Asn-Leu-Pro-Thr-Ala-Val-Tyr-Met-Val-Thr-OH (MW 1,222 Da) by quantitative time-of-flight electrospray ionization mass spectrometry. Purified antioxidant peptide from bigeye tuna dark muscle (APTDM) was investigated for its antioxidant activities using both free radical scavenging effects and polyunsaturated fatty acid (PUFA) peroxidation inhibitory activity. The results showed that APTDM effectively quenched with low 50% inhibitory concentration values compared to vitamin C as a positive control against four different free radicals: 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, superoxide, and alkyl radical. APTDM also inhibited PUFA peroxidation in a linoleic acid emulsion system, and the activity was similar to that of alpha-tocopherol. We further investigated its antioxidant activities on cellular systems, and the results showed that APTDM significantly scavenged cellular radicals and enhanced the viability of tert-butyl hydroperoxide-induced cytotoxicity. These results indicate that APTDM or a peptide fraction containing APTDM would be a beneficial ingredient for functional food and/or pharmaceuticals. PMID:19053853

  20. Coordinated defence and the liver.

    PubMed

    Elias, Elwyn; Mills, Charles O

    2007-04-01

    The liver is strategically placed to protect the body against a vast array of potentially harmful compounds. The steps involved include phase I metabolism which makes molecules more reactive and phase II reactions which generally enhance solubility in bile or urine. Recent discoveries have shown how regulation of these reactions is also closely allied to expression of membrane transporters which excrete the products of biotransformation into bile and prevent their reabsorption via the intestine. The coordinated activity of these various functions is orchestrated by orphan nuclear receptors which, in response to an encounter with a potential toxin, are able to induce expression of the genes involved in its biotransformation and excretion. Lithocholic acid (LCA) is routinely produced in our intestine by bacterial deconjugation of chenodeoxycholic acid a major bile acid in humans. In human liver the presence of LCA is sensed by the pregnane X receptor (PXR) which has the potential to switch on all the genes required for safe metabolism and elimination of LCA from the body. These include cytochrome P450 3A which hydroxylates LCA to more soluble forms and sulfotransferase (SULT2A1) which by sulphation of LCA makes it more readily solublein bile and enhances its faecal excretion. Similarly, PXR exposure to LCA produces up-regulated expression of the membrane transporters MDR1 and MRP2 which excrete metabolites of LCA. Evidence is accumulating in support of the hypothesis that deficiencies in these defence mechanisms underlie susceptibility to primary sclerosing cholangitis and ulcerative colitis. PMID:17491508

  1. Host defences against Giardia lamblia.

    PubMed

    Lopez-Romero, G; Quintero, J; Astiazarán-García, H; Velazquez, C

    2015-08-01

    Giardia spp. is a protozoan parasite that inhabits the upper small intestine of mammals and other species and is the aetiological agent of giardiasis. It has been demonstrated that nitric oxide, mast cells and dendritic cells are the first line of defence against Giardia. IL-6 and IL-17 play an important role during infection. Several cytokines possess overlapping functions in regulating innate and adaptive immune responses. IgA and CD4(+) T cells are fundamental to the process of Giardia clearance. It has been suggested that CD4(+) T cells play a double role during the anti-Giardia immune response. First, they activate and stimulate the differentiation of B cells to generate Giardia-specific antibodies. Second, they act through a B-cell-independent mechanism that is probably mediated by Th17 cells. Several Giardia proteins that stimulate humoral and cellular immune responses have been described. Variant surface proteins, α-1 giardin, and cyst wall protein 2 can induce host protective responses to future Giardia challenges. The characterization and evaluation of the protective potential of the immunogenic proteins that are associated with Giardia will offer new insights into host-parasite interactions and may aid in the development of an effective vaccine against the parasite. PMID:26072999

  2. Physiological Antioxidative Network of the Bilirubin System in Aging and Age-Related Diseases

    PubMed Central

    Kim, Sung Young; Park, Sang Chul

    2012-01-01

    Oxidative stress is detrimental to life process and is particularly responsible for aging and age-related diseases. Thus, most organisms are well equipped with a spectrum of biological defense mechanisms against oxidative stress. The major efficient antioxidative mechanism is the glutathione system, operating a redox cycling mechanism for glutathione utilization, which consists of glutathione and its peroxidase and reductase. However, this system is mainly effective for hydrophilic oxidants, while lipophilic oxidants require another scavenging system. Since many age-related pathological conditions are related to lipid peroxidation, especially in association with the aging process, the physiological role of the scavenging system for lipophilic oxidants should be considered. In this regard, the biliverdin to bilirubin conversion pathway, via biliverdin reductase (BVR), is suggested to be another major protective mechanism that scavenges lipophilic oxidants because of the lipophilic nature of bilirubin. The efficiency of this bilirubin system might be potentiated by operation of the intertwined bicyclic systems of the suggested redox metabolic cycle of biliverdin and bilirubin and the interactive control cycle of BVR and heme oxygenase. In order to combat oxidative stress, both antioxidative systems against hydrophilic and lipophilic oxidants are required to work cooperatively. In this regard, the roles of the bilirubin system in aging and age-related diseases are reassessed in this review, and their interacting networks are evaluated. PMID:22457648

  3. Effects of water-soluble natural antioxidants on photosensitized oxidation of conjugated linoleic acid in an oil-in-water emulsion system.

    PubMed

    Liu, T-T; Yang, T-S

    2008-05-01

    The effect of photosensitized oxidation of conjugated linoleic acid in an oil-in-water (o/w) emulsion system was studied. Water-soluble natural antioxidants, including apple polyphenols from apple extract, green tea extract, 4-hydroxy-2(or 5)-ethyl-5(or2)-methyl-3(2H)-furanone(HEMF), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), and ascorbic acid, were tested for antioxidant activity in this system. The green tea extract showed the highest antioxidant activity followed by ascorbic acid. Apple polyphenols did not give significant antioxidant activity. HEMF and HDMF exhibited a prooxidant effect. The antioxidant activity of tea catechins was also investigated. Of them, EGCG and ECG exhibited antioxidant activity at 50 ppm, but the antioxidant activity between them was not significantly different (P < 0.05). Comparatively, EC, EGC, and GCG showed no significant antioxidative effect at 50 ppm. When the concentration increased to 100 ppm, the antioxidant activity of ECG and EGCG significantly increased compared with that at 50 ppm, and EGCG had higher antioxidant activity than ECG. GCG also showed significant antioxidant activity at 100 ppm. EGCG exhibited the highest antioxidant activity among the tea catechins in the emulsion system at 100 ppm. PMID:18460119

  4. Carotenoids, total polyphenols and antioxidant activity of grapes (Vitis vinifera) cultivated in organic and conventional systems

    PubMed Central

    2012-01-01

    Background Organic agriculture involve plants which are cultivated without using synthetic pesticides, herbicides or fertilizers and promotes biodiversity, biological cycles and improve the product quality. The carotenoids, total polyphenols and the antioxidant activity from skins of some wine and table grapes cultivated in organic and conventional agriculture were studied. Results The main carotenoids identified using high performance liquid chromatography were lutein and ß-carotene. Muscat Ottonel variety has the highest ß-carotene concentration 504.9 μg/kg for organic and 593.2 μg/kg for conventional grapes. For the organic farming, the total polyphenols content were in the range of 163.23 – 1341.37 mg GAE/kg fresh weight (FW) and 148.47 – 1231.38 mg GAE/kg FW for the conventional grapes. The highest ORAC values were obtained for blue-black variety Napoca in both farming system (43.5 ± 0.95 μmol TE/g organic; 40.4 ± 0.5 μmol TE/g conventional) and lowest for Aromat de Iaşi (16.8 ± 0.6 μmol TE/g organic; 14.7 ± 1.6 μmol TE/g conventional). Napoca variety showed also the highest antioxidant activity measured by DPPH method in both cultivated system. Conclusion Nine grape varieties cultivated in organic and conventional systems were compared regarding the carotenoids, total polyphenols and antioxidant activity. The white grape varieties have a higher carotenoids content compared with the blue-black cultivars while the blue-black varieties contain higher TPC and exhibit higher antioxidant activity (except for Muscat Hamburg-ORAC). Vitis vinifera grape skins originating from wine or table grape varieties can be used as a potential source of natural antioxidants. PMID:22762349

  5. Environmental contamination of chrysotile asbestos and its toxic effects on antioxidative system of Lemna gibba.

    PubMed

    Trivedi, A K; Ahmad, I; Musthapa, M S; Ansari, F A

    2007-04-01

    Asbestos was monitored in various plant samples around an asbestos cement factory. Asbestos residue was found on the surface of all plant samples monitored. Based on asbestos concentration found in different plant samples during monitoring and on the property of asbestos to cause reactive oxygen species-mediated oxidative stress in animal models, laboratory experiments were conducted to assess the toxicity of chrysotile asbestos on an aquatic macrophyte, duckweed (Lemna gibba.). L. gibba plants were exposed to four concentrations (0.5, 1.0, 2.0, and 5.0 microg/mL) of chrysotile asbestos under laboratory conditions, and alterations in the glutathione and ascorbate antioxidative system were estimated at postexposure days 7, 14, 21, and 28 in order to assess changes in their level as suitable biomarkers of chrysotile contamination. Chrysotile exposure caused a decrease in total and reduced glutathione and an enhancement in the oxidized glutathione as well as the reduced/oxidized glutathione ratio. An increase in ascorbate pool size, and reduced as well as oxidized ascorbate was found to be accompanied by a decrease in the ratio of reduced/oxidized ascorbate. Alteration in the glutathione and ascorbate level might be considered as a biomarker of exposure to an unsafe environment because these are essential compounds of the general antioxidative strategy to overcome oxidative stress due to environmental constraints. Because an increase in the oxidation rate of antioxidants weakens cellular defenses and indicates a precarious state, they could constitute indicators of toxicity. PMID:17354032

  6. Salt-induced modulation in growth, photosynthesis and antioxidant system in two varieties of Brassica juncea.

    PubMed

    Wani, Arif Shafi; Ahmad, Aqil; Hayat, Shamsul; Fariduddin, Qazi

    2013-04-01

    The present study was carried out to examine salt-induced modulation in growth, photosynthetic characteristics and antioxidant system in two cultivars of Brassica juncea Czern and Coss varieties (Varuna and RH-30). The surface sterilized seeds of these varieties were sown in the soil amended with different levels (2.8, 4.2 or 5.6 dsm(-1)) of sodium chloride under a simple randomized block design. The salt treatment significantly decreased growth, net photosynthetic rate and its related attributes, chlorophyll fluorescence, SPAD value of chlorophyll, leaf carbonic anhydrase activity and leaf water potential, whereas electrolyte leakage, proline content, and activity of catalase, peroxidase and superoxide dismutase enzymes increased in both the varieties at 30 d stage of growth. The variety Varuna was found more resistant than RH-30 to the salt stress and possessed higher values for growth, photosynthetic attributes and antioxidant enzymes. Out of the graded concentrations (2.8, 4.2 or 5.6 dsm(-1)) of sodium chloride, 2.8 sm(-1) was least toxic and 5.6 dsm(-1) was most harmful. The variation in the responses of these two varieties to salt stress is attributed to their differential photosynthetic traits, SPAD chlorophyll value and antioxidant capacity, which can be used as potential markers for screening mustard plants for salt tolerance. PMID:23961235

  7. Effects of Hg(II) exposure on MAPK phosphorylation and antioxidant system in D. melanogaster.

    PubMed

    Paula, M T; Zemolin, A P; Vargas, A P; Golombieski, R M; Loreto, E L S; Saidelles, A P; Picoloto, R S; Flores, E M M; Pereira, A B; Rocha, J B T; Merritt, T J S; Franco, J L; Posser, T

    2014-06-01

    The heavy metal mercury is a known toxin, but while the mechanisms involved in mercury toxicity have been well demonstrated in vertebrates, little is known about toxicological effects of this metal in invertebrates. Here, we present the results of our study investigating the effects associated with exposure of fruit fly Drosophila melanogaster to inorganic mercury (HgCl2 ). We quantify survival and locomotor performance as well as a variety of biochemical parameters including antioxidant status, MAPK phosphorylation and gene expression following mercury treatment. Our results demonstrate that exposure to Hg(II) through diet induced mortality and affected locomotor performance as evaluated by negative geotaxis, in D. melanogaster. We also saw a significant impact on the antioxidant system including an inhibition of acetylcholinesterase (Ache), glutathione S-transferase (GST) and superoxide dismutase (SOD) activities. We found no significant alteration in the levels of mRNA of antioxidant enzymes or NRF-2 transcriptional factor, but did detect a significant up regulation of the HSP83 gene. Mercury exposure also induced the phosphorylation of JNK and ERK, without altering p38(MAPK) and the concentration of these kinases. In parallel, Hg(II) induced PARP cleavage in a 89 kDa fragment, suggesting the triggering of apoptotic cell death in response to the treatment. Taken together, this data clarifies and extends our understanding of the molecular mechanisms mediating Hg(II) toxicity in an invertebrate model. PMID:22700419

  8. Salt-induced modulation in growth, photosynthesis and antioxidant system in two varieties of Brassica juncea

    PubMed Central

    Wani, Arif Shafi; Ahmad, Aqil; Hayat, Shamsul; Fariduddin, Qazi

    2013-01-01

    The present study was carried out to examine salt-induced modulation in growth, photosynthetic characteristics and antioxidant system in two cultivars of Brassica juncea Czern and Coss varieties (Varuna and RH-30). The surface sterilized seeds of these varieties were sown in the soil amended with different levels (2.8, 4.2 or 5.6 dsm−1) of sodium chloride under a simple randomized block design. The salt treatment significantly decreased growth, net photosynthetic rate and its related attributes, chlorophyll fluorescence, SPAD value of chlorophyll, leaf carbonic anhydrase activity and leaf water potential, whereas electrolyte leakage, proline content, and activity of catalase, peroxidase and superoxide dismutase enzymes increased in both the varieties at 30 d stage of growth. The variety Varuna was found more resistant than RH-30 to the salt stress and possessed higher values for growth, photosynthetic attributes and antioxidant enzymes. Out of the graded concentrations (2.8, 4.2 or 5.6 dsm−1) of sodium chloride, 2.8 sm−1 was least toxic and 5.6 dsm−1 was most harmful. The variation in the responses of these two varieties to salt stress is attributed to their differential photosynthetic traits, SPAD chlorophyll value and antioxidant capacity, which can be used as potential markers for screening mustard plants for salt tolerance. PMID:23961235

  9. Influence of prebiotics and antioxidants in bread on the immune system, antioxidative status and antioxidative capacity in male smokers and non-smokers.

    PubMed

    Seidel, Christiane; Boehm, Volker; Vogelsang, Heinz; Wagner, Andreas; Persin, Christoph; Glei, Michael; Pool-Zobel, Beatrice L; Jahreis, Gerhard

    2007-02-01

    Interest in functional foods is increasing. The aim of the present study was to investigate breads supplemented with functional components. One was bread supplemented with inulin, linseed and soya fibre (prebiotic bread). The other was a prebiotic antioxidant bread (pre-aox-bread), which additionally contained green tea powder, herbs and tomato paste. The effects of these two breads on immunological and antioxidative parameters were compared with control bread (placebo). Twenty smokers and eighteen non-smokers were enrolled in the randomised parallel study, which consisted of a control period and an intervention period, each lasting for 5 weeks. Daily intake of bread and nutrients did not differ between the intervention and the control period. Most of the twenty-three investigated immunological parameters measured in peripheral blood were unaffected. However, the percentage of CD19 increased after intervention with prebiotic bread, whereas intercellular adhesion molecule-1 (ICAM-1) and CD3+NK+ (P < 0.05) decreased in both intervention arms. The ferric reducing ability of plasma (FRAP) was increased after consumption of the pre-aox-bread for non-smokers (1256 v. 1147 micromol/l; P = 0.019) and remained unchanged for smokers consuming the pre-aox-bread. All analysed carotenoids (P antioxidative potentials for this type of functional food. PMID:17298705

  10. Design of two electrode system for detection of antioxidant capacity with photoelectrochemical platform.

    PubMed

    Han, Dongxue; Ma, Weiguang; Wang, Lingnan; Ni, Shuang; Zhang, Nan; Wang, Wei; Dong, Xiandui; Niu, Li

    2016-01-15

    Recently, a flow photoelectrochemical cell has been first developed and applied to assay global antioxidant capacity in our group. Yet, shortcomings of liquid reference electrode such as sample contaminations from the leaking of the reference solution, mechanically fragile, temperature and light sensitivity, etc. are significant restrictions for integration and miniaturization of photoelectrochemical sensing instruments, which have greatly limited their practical applications. Bearing these problems, in this work a novel two electrode flow photoelectron-chemical system (two-EPCS) has been developed for detection of antioxidant capacity. It is noteworthy that the electrochemical modulation-free mode (detection at the potential of 0.0V) is performed, which has greatly simplified the analysis process and will result in significant simplifications of the instrument integrations. During the sample analysis, both standard antioxidants and commercial beverages were detected. Results evaluated from the two-EPCS are well agreed with those of the traditional three-EPCS at low potentials. By unloading of the reference electrode, it is of great convenience to design a novel photoelectrochemical microfluidic chip based on the two-EPCS, which has also been successfully applied for antioxidant capacity assay. It is satisfactory that comparable detection concentration range and sensitivity were accomplished by applying the microfluidic chip technique. Moreover, the two-EPCS is verified to be a universal platform which does not depend on selected optoelectronic materials but pervasive for general photocatalysts. Such a two-EPCS should be considered as a feasible alternative to the three-EPCS, which will become a promising candidate for industrial and commercial photoelectrochemical sensing instrument integrations in the future. PMID:26363494

  11. Analysis of apoplastic and symplastic antioxidant system in shallot leaves: impacts of weak static electric and magnetic field.

    PubMed

    Cakmak, Turgay; Cakmak, Zeynep E; Dumlupinar, Rahmi; Tekinay, Turgay

    2012-07-15

    Impacts of electric and magnetic fields (EFs and MFs) on a biological organism vary depending on their application style, time, and intensities. High intensity MF and EF have destructive effects on plants. However, at low intensities, these phenomena are of special interest because of the complexity of plant responses. This study reports the effects of continuous, low-intensity static MF (7 mT) and EF (20 kV/m) on growth and antioxidant status of shallot (Allium ascalonicum L.) leaves, and evaluates whether shifts in antioxidant status of apoplastic and symplastic area help plants to adapt a new environment. Growth was induced by MF but EF applied emerged as a stress factor. Despite a lack of visible symptoms of injury, lipid peroxidation and H₂O₂ levels increased in EF applied leaves. Certain symplastic antioxidant enzyme activities and non-enzymatic antioxidant levels increased in response to MF and EF applications. Antioxidant enzymes in the leaf apoplast, by contrast, were found to show different regulation responses to EF and MF. Our results suggest that apoplastic constituents may work as potentially important redox regulators sensing and signaling environmental changes. Static continuous MF and EF at low intensities have distinct impacts on growth and the antioxidant system in plant leaves, and weak MF is involved in antioxidant-mediated reactions in the apoplast, resulting in overcoming a possible redox imbalance. PMID:22647960

  12. A Comparative Analysis of Sonic Defences in Bombycoidea Caterpillars.

    PubMed

    Bura, Veronica L; Kawahara, Akito Y; Yack, Jayne E

    2016-01-01

    Caterpillars have long been used as models for studying animal defence. Their impressive armour, including flamboyant warning colours, poisonous spines, irritating sprays, and mimicry of plant parts, snakes and bird droppings, has been extensively documented. But research has mainly focused on visual and chemical displays. Here we show that some caterpillars also exhibit sonic displays. During simulated attacks, 45% of 38 genera and 33% of 61 species of silk and hawkmoth caterpillars (Bombycoidea) produced sounds. Sonic caterpillars are found in many distantly-related groups of Bombycoidea, and have evolved four distinct sound types- clicks, chirps, whistles and vocalizations. We propose that different sounds convey different messages, with some designed to warn of a chemical defence and others, to startle predators. This research underscores the importance of exploring acoustic communication in juvenile insects, and provides a model system to explore how different signals have evolved to frighten, warn or even trick predators. PMID:27510510

  13. A Comparative Analysis of Sonic Defences in Bombycoidea Caterpillars

    PubMed Central

    Bura, Veronica L.; Kawahara, Akito Y.; Yack, Jayne E.

    2016-01-01

    Caterpillars have long been used as models for studying animal defence. Their impressive armour, including flamboyant warning colours, poisonous spines, irritating sprays, and mimicry of plant parts, snakes and bird droppings, has been extensively documented. But research has mainly focused on visual and chemical displays. Here we show that some caterpillars also exhibit sonic displays. During simulated attacks, 45% of 38 genera and 33% of 61 species of silk and hawkmoth caterpillars (Bombycoidea) produced sounds. Sonic caterpillars are found in many distantly-related groups of Bombycoidea, and have evolved four distinct sound types- clicks, chirps, whistles and vocalizations. We propose that different sounds convey different messages, with some designed to warn of a chemical defence and others, to startle predators. This research underscores the importance of exploring acoustic communication in juvenile insects, and provides a model system to explore how different signals have evolved to frighten, warn or even trick predators. PMID:27510510

  14. The Morality and Economics of Safety in Defence Procurement

    NASA Astrophysics Data System (ADS)

    Clement, Tim

    Ministry of Defence policy is to conform as closely as possible to UK health and safety legislation in all its operations. We consider the implications of the law and the guidance provided by the Health and Safety Executive for the arguments we need to make for the safety of defence procurements, and extract four general principles to help in answering the questions that arise when considering the safety of systems with complex behaviour. One of these principles is analysed further to identify how case law and the guidance interpret the requirement for risks to be reduced so far as is reasonably practicable. We then apply the principles to answer some questions that have arisen in our work as Independent Safety Auditors, including the limits to the tolerability of risk to armed forces personnel and civilians in wartime, and the acceptability of the transfer of risk from one group to another when controls on risk are introduced.

  15. Antioxidant activity of spice extracts in a liposome system and in cooked pork patties and the possible mode of action.

    PubMed

    Kong, Baohua; Zhang, Huiyun; Xiong, Youling L

    2010-08-01

    Three experiments were conducted to assess the antioxidant efficacy of spice extracts in cooked meat. In experiment 1, antioxidant activity of 13 common spice extracts was screened in a liposome system. Six of the extracts (clove, rosemary, cassia bark, liquorice, nutmeg, and round cardamom), identified to have the greatest total phenolic contents, were strongly inhibitory of TBARS formation. In experiment 2, 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric-reducing power, and metal chelation of these six spice extracts were evaluated. Clove exhibited the greatest reducing power, and all had strong DPPH scavenging activity. In experiment 3, clove, rosemary, and cassia bark extracts were further tested for in situ antioxidant efficacy. Cooked pork patties containing these spice extracts had markedly reduced TBARS formation and off-flavour scores but a more stable red colour, during storage. The results demonstrated strong potential of spice extracts as natural antioxidants in cooked pork products. PMID:20430533

  16. Combined Effects of Lanthanum (III) and Acid Rain on Antioxidant Enzyme System in Soybean Roots

    PubMed Central

    Zhang, Xuanbo; Du, Yuping; Wang, Lihong; Zhou, Qing; Huang, Xiaohua; Sun, Zhaoguo

    2015-01-01

    Rare earth element pollution (REEs) and acid rain (AR) pollution simultaneously occur in many regions, which resulted in a new environmental issue, the combined pollution of REEs and AR. The effects of the combined pollution on the antioxidant enzyme system of plant roots have not been reported. Here, the combined effects of lanthanum ion (La3+), one type of REE, and AR on the antioxidant enzyme system of soybean roots were investigated. In the combined treatment of La3+ (0.08 mM) and AR, the cell membrane permeability and the peroxidation of cell membrane lipid of soybean roots increased, and the superoxide dismutase, catalase, peroxidase and reduced ascorbic acid served as scavengers of reactive oxygen species. In other combined treatments of La3+ (0.40 mM, 1.20 mM) and AR, the membrane permeability, malonyldialdehyde content, superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content increased, while the catalase activity decreased. The increased superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content were inadequate to scavenge the excess hydrogen peroxide and superoxide, leading to the damage of the cell membrane, which was aggravated with the increase in the concentration of La3+ and the level of AR. The deleterious effects of the combined treatment of La3+ and AR were stronger than those of the single treatment of La3+ or AR. Moreover, the activity of antioxidant enzyme system in the combined treatment group was affected directly and indirectly by mineral element content in soybean plants. PMID:26230263

  17. Combined Effects of Lanthanum (III) and Acid Rain on Antioxidant Enzyme System in Soybean Roots.

    PubMed

    Zhang, Xuanbo; Du, Yuping; Wang, Lihong; Zhou, Qing; Huang, Xiaohua; Sun, Zhaoguo

    2015-01-01

    Rare earth element pollution (REEs) and acid rain (AR) pollution simultaneously occur in many regions, which resulted in a new environmental issue, the combined pollution of REEs and AR. The effects of the combined pollution on the antioxidant enzyme system of plant roots have not been reported. Here, the combined effects of lanthanum ion (La3+), one type of REE, and AR on the antioxidant enzyme system of soybean roots were investigated. In the combined treatment of La3+ (0.08 mM) and AR, the cell membrane permeability and the peroxidation of cell membrane lipid of soybean roots increased, and the superoxide dismutase, catalase, peroxidase and reduced ascorbic acid served as scavengers of reactive oxygen species. In other combined treatments of La3+ (0.40 mM, 1.20 mM) and AR, the membrane permeability, malonyldialdehyde content, superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content increased, while the catalase activity decreased. The increased superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content were inadequate to scavenge the excess hydrogen peroxide and superoxide, leading to the damage of the cell membrane, which was aggravated with the increase in the concentration of La3+ and the level of AR. The deleterious effects of the combined treatment of La3+ and AR were stronger than those of the single treatment of La3+ or AR. Moreover, the activity of antioxidant enzyme system in the combined treatment group was affected directly and indirectly by mineral element content in soybean plants. PMID:26230263

  18. [Alterations of prooxidant-antioxidant system of rat liver at ethanol and tetracycline action].

    PubMed

    Nedoshytko, Kh Iu

    2013-01-01

    The state of antioxidant system and fatty acid composition of lipids in the liver tissues of rats of different sex at the ethanol and tetracycline action and at the influence of biologically active additives (BAA) "Alpha + Omega" at a dose of 0.5 mg/kg b.w. per os was investigated. It was found that the contet of lipid peroxidation products in the liver was increased at the action of 40% ethanol at a dose of 7 ml/kg b.w. per os and tetracycline--500 mg/kg and more profound at their joint using. However, the content of diene conjugates was stronger increased in the liver of females at the action of ethanol, while in the liver of males at the action of tetracycline (P < 0.05). It was shown that the application of the investigated compounds led to the reduction of an antioxidant defense system activity of males and females liver, as evidenced by the decrease of superoxide dismutase activity by 46 and 43% and reduction of glutathione content by 39 and 38% (P < 0.05). The activity of alanineaminotransferase, aspartateaminotransferase and alkalinephosphatase was increased in the liver of males and females under the influence of ethanol and tetracycline and more profound at their joint usage (P < 0.05). It was established that ethanol and tetracycline unidirectionally changed fatty acid composition of total lipids of rat liver, but at the ethanol action the changes were more expressed in females while at the tetracycline action in males. The application during 14 days of BAA "Alpha + Omega" to male and female rats with an acute tetracycline damage at subacute ethanol action led to partial normalization of prooxidant-antioxidant system and the relative content of total lipids fatty acids of the liver of both sexes animals. PMID:24479333

  19. Antioxidative and proteolytic systems protect mitochondria from oxidative damage in S-deficient Arabidopsis thaliana.

    PubMed

    Ostaszewska-Bugajska, Monika; Rychter, Anna M; Juszczuk, Izabela M

    2015-08-15

    We examined the functioning of the antioxidative defense system in Arabidopsis thaliana under sulphur (S) deficiency with an emphasis on the role of mitochondria. In tissue extracts and in isolated mitochondria from S-deficient plants, the concentration of non-protein thiols declined but protein thiols did not change. Superoxide anion and hydrogen peroxide were accumulated in leaf blades and the generation of superoxide anion by isolated mitochondria was higher. Lower abundance of reduced (GSH) plus oxidized (GSSG) glutathione in the leaf and root tissues, and leaf mitochondria from S-deficient plants was accompanied by a decrease in the level of GSH and the changes in the GSH/GSSG ratios. In the chloroplasts, the total level of glutathione decreased. Lower levels of reduced (AsA) and oxidized (DHA) ascorbate were reflected in much higher ratios of AsA/DHA. Sulphur deficiency led to an increase in the activity of cytosolic, mitochondrial and chloroplastic antioxidative enzymes, peroxidases, catalases and superoxide dismutases. The protein carbonyl level was higher in the leaves of S-deficient plants and in the chloroplasts, while in the roots, leaf and root mitochondria it remained unchanged. Protease activity in leaf extracts of S-deficient plants was higher, but in root extracts it did not differ. The proteolytic system reflected subcellular specificity. In leaf and root mitochondria the protease activity was higher, whereas in the chloroplasts it did not change. We propose that the preferential incorporation of S to protein thiols and activation of antioxidative and proteolytic systems are likely important for the survival of S-deficient plants and that the mitochondria maintain redox homeostasis. PMID:26339750

  20. Stimulatory and possible antioxidant effects of High Density Green Photons (HDGP) on cellular systems

    PubMed Central

    Paslaru, L; Nastase, A; Stefan, L; Florea, R; Sorop, A; Ionescu, E; Popescu, I; Comorasan, S

    2014-01-01

    The interactions between the electromagnetic field and the biological systems were extensively investigated, with remarkable results and advanced technologies. Nevertheless, the visible domain of the spectrum has been rather neglected, since the classic physics did not allow electronic transitions induced by visible light. Recently, the interaction of light with the matter has generated a new scientific domain known in Physics as optical manipulation, with the new concepts of optical matter and optical force. This article presents the results of our work concerning in vitro effects of High Density Green Photons (HDGP) irradiation on cell cultures: stimulation of cell proliferation and migration and a possible antioxidant action. PMID:25713633

  1. Do strigolactones contribute to plant defence?

    PubMed

    Torres-Vera, Rocío; García, Juan M; Pozo, María J; López-Ráez, Juan A

    2014-02-01

    Strigolactones are multifunctional molecules involved in several processes outside and within the plant. As signalling molecules in the rhizosphere, they favour the establishment of arbuscular mycorrhizal symbiosis, but they also act as host detection cues for root parasitic plants. As phytohormones, they are involved in the regulation of plant architecture, adventitious rooting, secondary growth and reproductive development, and novel roles are emerging continuously. In the present study, the possible involvement of strigolactones in plant defence responses was investigated. For this purpose, the resistance/susceptibility of the strigolactone-deficient tomato mutant Slccd8 against the foliar fungal pathogens Botrytis cinerea and Alternaria alternata was assessed. Slccd8 was more susceptible to both pathogens, pointing to a new role for strigolactones in plant defence. A reduction in the content of the defence-related hormones jasmonic acid, salicylic acid and abscisic acid was detected by high-performance liquid chromatography coupled to tandem mass spectrometry in the Slccd8 mutant, suggesting that hormone homeostasis is altered in the mutant. Moreover, the expression level of the jasmonate-dependent gene PinII, involved in the resistance of tomato to B. cinerea, was lower than in the corresponding wild-type. We propose here that strigolactones play a role in the regulation of plant defences through their interaction with other defence-related hormones, especially with the jasmonic acid signalling pathway. PMID:24112811

  2. Signalling Network Construction for Modelling Plant Defence Response

    PubMed Central

    Miljkovic, Dragana; Stare, Tjaša; Mozetič, Igor; Podpečan, Vid; Petek, Marko; Witek, Kamil; Dermastia, Marina; Lavrač, Nada; Gruden, Kristina

    2012-01-01

    Plant defence signalling response against various pathogens, including viruses, is a complex phenomenon. In resistant interaction a plant cell perceives the pathogen signal, transduces it within the cell and performs a reprogramming of the cell metabolism leading to the pathogen replication arrest. This work focuses on signalling pathways crucial for the plant defence response, i.e., the salicylic acid, jasmonic acid and ethylene signal transduction pathways, in the Arabidopsis thaliana model plant. The initial signalling network topology was constructed manually by defining the representation formalism, encoding the information from public databases and literature, and composing a pathway diagram. The manually constructed network structure consists of 175 components and 387 reactions. In order to complement the network topology with possibly missing relations, a new approach to automated information extraction from biological literature was developed. This approach, named Bio3graph, allows for automated extraction of biological relations from the literature, resulting in a set of (component1, reaction, component2) triplets and composing a graph structure which can be visualised, compared to the manually constructed topology and examined by the experts. Using a plant defence response vocabulary of components and reaction types, Bio3graph was applied to a set of 9,586 relevant full text articles, resulting in 137 newly detected reactions between the components. Finally, the manually constructed topology and the new reactions were merged to form a network structure consisting of 175 components and 524 reactions. The resulting pathway diagram of plant defence signalling represents a valuable source for further computational modelling and interpretation of omics data. The developed Bio3graph approach, implemented as an executable language processing and graph visualisation workflow, is publically available at http://ropot.ijs.si/bio3graph/and can be utilised for

  3. Systemic DNA Damage Accumulation Under in Vivo Tumor Growth can be Inhibited by the Antioxidant Tempol

    PubMed Central

    Georgakilas, Alexandros G.; Redon, Christophe E.; Ferguson, Nicholas F.; Kryston, Thomas B.; Parekh, Palak; Dickey, Jennifer S.; Nakamura, Asako J.; Mitchell, James B.; Bonner, William M.; Martin, Olga A.

    2014-01-01

    Aims Recently we found that mice bearing subcutaneous non-metastatic tumors exhibited elevated levels of two types of complex DNA damage, i.e., double-strand breaks and oxidatively-induced clustered DNA lesions in various tissues throughout the body, both adjacent to and distant from the tumor site. This DNA damage was dependent on CCL2, a cytokine involved in the recruitment and activation of macrophages, suggesting that this systemic DNA damage was mediated via tumor-induced chronic inflammatory responses involving cytokines, activation of macrophages, and consequent free radical production. If free radicals are involved, then a diet containing an antioxidant may decrease the distant DNA damage. Results Here we repeated our standard protocol in cohorts of two syngeneic tumor-bearing C57BL/6NCr mice that were on a Tempol-supplemented diet. We show that double-strand break and oxidatively-induced clustered DNA lesion levels were considerably decreased, about 2-3 fold, in the majority of tissues studied from the tumor-bearing mice fed the antioxidant Tempol compared to the control tumor-bearing mice. Similar results were also observed in nude mice suggesting that the Tempol effects are independent of functioning adaptive immunity. Conclusions This is the first in vivo study demonstrating the effect of a dietary antioxidant on abscopal DNA damage in tissues distant from a localized source of genotoxic stress. These findings may be important for understanding the mechanisms of genomic instability and carcinogenesis caused by chronic stress-induced systemic DNA damage and for developing preventative strategies. PMID:25069035

  4. Photosynthesis and antioxidant defense system of Gynura Bicolor DC grown at different elevated CO2 levels

    NASA Astrophysics Data System (ADS)

    Wang, Minjuan; Liu, Hong; Fu, Yuming

    Atmospheric carbon dioxide concentration [CO _{2}] will increase in the future and will affect global climate and ecosystem productivity. However, this is not clearly an area that requires further study on the most appropriate [CO _{2}] selection for plant growth and quality in a closed, controlled environment. The aim of this study was to determine the variation of photosynthetic characteristics and antioxidant status under five CO _{2} concentration (400, 800, 1200, 2000 and 3000 umol mol (-1) ) on the leaf of Gynura bicolor DC. Here the results show that net photosynthetic rate(Pn), Chl content, edible biomass(EB), leaf blade width(LBW), root weight(RW), fructose(Fru) and sucrose(Suc) of Gynura bicolor DC increased under elevated [CO _{2}] of 800 umol mol (-1) , 1200 umol mol (-1) and 2000 umol mol (-1) . On the contrary, photosynthesis and biomass production declined significantly at 3000 umol mol (-1) CO _{2}, While Lipid peroxidation (LPO), malondialdehyde (MDA) and hydrogen peroxide (H _{2}O _{2}) achieved the highest levels. Furthermore, the contents of glutathione (GSH), vitamin C (VC), and vitamin E (VE), and total antioxidant capacity (T-AOC), the activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) reached the highest level at 2000 umol mol ({-1) }CO _{2}. Results imply that a significant increase in growth and antioxidant defense system of Gynura bicolor DC occurred under 800-2000 umol mol (-1) of CO _{2} concentration provided a theoretical basis for the application for plants selection in Bioregeneration Life Support System (BLSS) and a closed controlled environment.

  5. Differential Responses of the Antioxidant System of Ametryn and Clomazone Tolerant Bacteria

    PubMed Central

    Peters, Leila Priscila; Carvalho, Giselle; Martins, Paula Fabiane; Dourado, Manuella Nóbrega; Vilhena, Milca Bartz; Pileggi, Marcos; Azevedo, Ricardo Antunes

    2014-01-01

    The herbicides ametryn and clomazone are widely used in sugarcane cultivation, and following microbial degradation are considered as soil and water contaminants. The exposure of microorganisms to pesticides can result in oxidative damage due to an increase in the production of reactive oxygen species (ROS). This study investigated the response of the antioxidant systems of two bacterial strains tolerant to the herbicides ametryn and clomazone. Bacteria were isolated from soil with a long history of ametryn and clomazone application. Comparative analyses based on 16S rRNA gene sequences revealed that strain CC07 is phylogenetically related to Pseudomonas aeruginosa and strain 4C07 to P. fulva. The two bacterial strains were grown for 14 h in the presence of separate and combined herbicides. Lipid peroxidation, reduced glutathione content (GSH) and antioxidant enzymes activities were evaluated. The overall results indicated that strain 4C07 formed an efficient mechanism to maintain the cellular redox balance by producing reactive oxygen species (ROS) and subsequently scavenging ROS in the presence of the herbicides. The growth of bacterium strain 4C07 was inhibited in the presence of clomazone alone, or in combination with ametryn, but increased glutathione reductase (GR) and glutathione S-transferase (GST) activities, and a higher GSH concentration were detected. Meanwhile, reduced superoxide dismutase (SOD), catalase (CAT) and GST activities and a lower concentration of GSH were detected in the bacterium strain CC07, which was able to achieve better growth in the presence of the herbicides. The results suggest that the two bacterial strains tolerate the ametryn and clomazone herbicides with distinctly different responses of the antioxidant systems. PMID:25380132

  6. Differential responses of the antioxidant system of ametryn and clomazone tolerant bacteria.

    PubMed

    Peters, Leila Priscila; Carvalho, Giselle; Martins, Paula Fabiane; Dourado, Manuella Nóbrega; Vilhena, Milca Bartz; Pileggi, Marcos; Azevedo, Ricardo Antunes

    2014-01-01

    The herbicides ametryn and clomazone are widely used in sugarcane cultivation, and following microbial degradation are considered as soil and water contaminants. The exposure of microorganisms to pesticides can result in oxidative damage due to an increase in the production of reactive oxygen species (ROS). This study investigated the response of the antioxidant systems of two bacterial strains tolerant to the herbicides ametryn and clomazone. Bacteria were isolated from soil with a long history of ametryn and clomazone application. Comparative analyses based on 16S rRNA gene sequences revealed that strain CC07 is phylogenetically related to Pseudomonas aeruginosa and strain 4C07 to P. fulva. The two bacterial strains were grown for 14 h in the presence of separate and combined herbicides. Lipid peroxidation, reduced glutathione content (GSH) and antioxidant enzymes activities were evaluated. The overall results indicated that strain 4C07 formed an efficient mechanism to maintain the cellular redox balance by producing reactive oxygen species (ROS) and subsequently scavenging ROS in the presence of the herbicides. The growth of bacterium strain 4C07 was inhibited in the presence of clomazone alone, or in combination with ametryn, but increased glutathione reductase (GR) and glutathione S-transferase (GST) activities, and a higher GSH concentration were detected. Meanwhile, reduced superoxide dismutase (SOD), catalase (CAT) and GST activities and a lower concentration of GSH were detected in the bacterium strain CC07, which was able to achieve better growth in the presence of the herbicides. The results suggest that the two bacterial strains tolerate the ametryn and clomazone herbicides with distinctly different responses of the antioxidant systems. PMID:25380132

  7. Imbalance of the antioxidative system by plumbagin and Plumbago indica L. extract induces hepatotoxicity in mice

    PubMed Central

    Sukkasem, Nadta; Chatuphonprasert, Waranya; Tatiya-aphiradee, Nitima; Jarukamjorn, Kanokwan

    2016-01-01

    Background/Aim: Plumbago indica (PI) L. and its active constituent, plumbagin, has been traditionally claimed for several pharmacological activities; however, there is little information regarding their toxicity. The present study aims to examine the effects of plumbagin and PI extract (PI) on hepatic histomorphology and antioxidative system in mice. Materials and Methods: Adult male intelligent character recognition mice were intragastrically administered plumbagin (1, 5, and 15 mg/kg/day) or PI (20, 200, and 1,000 mg/kg/day) consecutively for 14 days. Hepatic histomorphology was examined. Plasma alanine transaminase (ALT) and aspartate transaminase (AST) levels, hepatic lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, and the ratio of reduced to oxidized glutathione (GSH/GSSG) were determined. Results: Plumbagin and PI concentration-dependently induced hepatic injury based on histopathological changes via imbalance of antioxidative system. Plumbagin and PI significantly increased plasma ALT and AST levels, hepatic lipid peroxidation, and GPx activity but significantly decreased hepatic SOD and CAT activities. The GSH/GSSG ratio was significantly reduced by plumbagin. Conclusion: Plumbagin and PI caused hepatotoxic effects in the mice by unbalancing of the redox defense system. Therefore, plumbagin and PI-containing supplements should be used cautiously, especially when consumed in high quantities or for long periods. PMID:27104034

  8. Omega-3 fatty acids differentially modulate enzymatic anti-oxidant systems in skeletal muscle cells.

    PubMed

    da Silva, E P; Nachbar, R T; Levada-Pires, A C; Hirabara, S M; Lambertucci, R H

    2016-01-01

    During physical activity, increased reactive oxygen species production occurs, which can lead to cell damage and in a decline of individual's performance and health. The use of omega-3 polyunsaturated fatty acids as a supplement to protect the immune system has been increasing; however, their possible benefit to the anti-oxidant system is not well described. Thus, the aim of this study was to evaluate whether the omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) can be beneficial to the anti-oxidant system in cultured skeletal muscle cells. C2C12 myocytes were differentiated and treated with either eicosapentaenoic acid or docosahexaenoic acid for 24 h. Superoxide content was quantified using the dihydroethidine oxidation method and superoxide dismutase, catalase, and glutathione peroxidase activity, and expression was quantified. We observed that the docosahexaenoic fatty acids caused an increase in superoxide production. Eicosapentaenoic acid induced catalase activity, while docosahexaenoic acid suppressed superoxide dismutase activity. In addition, we found an increased protein expression of the total manganese superoxide dismutase and catalase enzymes when cells were treated with eicosapentaenoic acid. Taken together, these data indicate that the use of eicosapentaenoic acid may present both acute and chronic benefits; however, the treatment with DHA may not be beneficial to muscle cells. PMID:26386577

  9. Porous antioxidant polymer microparticles as therapeutic systems for the airway inflammatory diseases.

    PubMed

    Jeong, Dahee; Kang, Changsun; Jung, Eunkyeong; Yoo, Donghyuck; Wu, Dongmei; Lee, Dongwon

    2016-07-10

    Inhaling steroidal anti-inflammatory drugs is the most common treatment for airway inflammatory diseases such as asthma. However, frequent steroid administration causes adverse side effects. Therefore, the successful clinical translation of numerous steroidal drugs greatly needs pulmonary drug delivery systems which are formulated from biocompatible and non-immunogenic polymers. We have recently developed a new family of biodegradable polymer, vanillyl alcohol-containing copolyoxalate (PVAX) which is able to scavenge hydrogen peroxide and exert potent antioxidant and anti-inflammatory activity. In this work, we report the therapeutic potential of porous PVAX microparticles which encapsulate dexamethasone (DEX) as a therapeutic system for airway inflammatory diseases. PVAX microparticles themselves reduced oxidative stress and suppressed the expression of pro-inflammatory tumor necrosis factor-alpha and inducible nitric oxide synthase in the lung of ovalbumin-challenged asthmatic mice. However, DEX-loaded porous PVAX microparticles showed significantly enhanced therapeutic effects than PVAX microparticles, suggesting the synergistic effects of PVAX with DEX. In addition, PVAX microparticles showed no inflammatory responses to lung tissues. Given their excellent biocompatibility and intrinsic antioxidant and anti-inflammatory activity, PVAX microparticles hold tremendous potential as therapeutic systems for the treatment of airway inflammatory diseases such as asthma. PMID:27151077

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

    PubMed

    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 (p<0.0001). After intervention, a significant increase in superoxide dismutase (SOD) activity (61.7%), glutathione peroxidase (GPx) activity (59.3%), the levels of vitamin E (83.7%), C (145.3%), total antioxidant capacity (TAC) (62.8%) and a significant decrease in MDA (40%) value were observed (p<0.0001). There was a significant negative correlation between MDA and TAC. The results suggest that supplementation with a combination of vitamins 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. PMID:21422713

  11. Improved Antioxidant Capacity of Optimization of a Self-Microemulsifying Drug Delivery System for Resveratrol.

    PubMed

    Chen, Ying; Zhang, Huiyong; Yang, Jing; Sun, Haiyan

    2015-01-01

    The use of nano-encapsulated resveratrol (RSV) in self-micro-emulsified drug delivery systems (SMEDDS) formulations was investigated. Self-emulsifying grading tests were used to establish the optimal ratio of oil, surfactant, and co-surfactant. The optimized system was further investigated for the droplet size and zeta potential at the different medium pH values by a Malvern Zetasizer and transmission electron microscopy (TEM). The antioxidant capacity and cytotoxicity of the formulation were detected by DCFH-DA and a CCK-8 assays. The results showed that the nano-emulsion based on ethyl oleate, Tween-80, and PEG-400 (35:40:25, w/w/w) was the most stable formulation due to the small droplet size (approximately 50 nm) and high zeta potential in a neutral environment. Furthermore, this formulation also exhibited a greater antioxidant capacity with less toxicity than free RSV. Taken together, considering these results and the simple fabrication process, this formulation could be used to deliver nutritional food supplements in a stable, efficient, and safe manner. PMID:26633319

  12. Effect of low copper exposure on the antioxidant system and some immune parameters.

    PubMed

    Kvietkauskaite, Raimonda; Dringeliene, Aldona; Markevicius, Arvydas; Siaurys, Almantus; Acaite, Jezefa

    2004-08-01

    Low-level copper excess was produced in male BALB/c mice by oral supplementation of copper sulfate solution during a 19-w period. The control Group was supplied with pure drinking water and the 2 experimental Groups with CuSO4.5H2O solutions at 120 mg Cu/L or 300 mg Cu/L, respectively. Compared to the control Group, the copper-dosed animals were slightly smaller, the weight of liver was significantly reduced and liver copper content increased. Chronic copper impaired the liver antioxidant defense system by decreasing activities of Cu,Zn-superoxide dismutase and catalase to 14% and 11% respectively. No significant changes were observed in hematological parameters, but flow cytometry revealed altered phenotypic properties of lymphocytes: decreased suppressor (CD8+CD4-), natural killer and its precursor (CD4+CD8+) cell percent, but increased immunoregulatory index (helper (CD4+CD8-)/suppressor (CD8+CD4-) ratio). Prolonged exposure to low copper concentration had been shown a deleterious effect on both antioxidant defense system enzymes and phenotypic properties of immunocompetent cells of mice. PMID:15303382

  13. Role of glutathione metabolism and glutathione-related antioxidant defense systems in hypertension.

    PubMed

    Robaczewska, J; Kedziora-Kornatowska, K; Kozakiewicz, M; Zary-Sikorska, E; Pawluk, H; Pawliszak, W; Kedziora, J

    2016-06-01

    The risk of developing chronic hypertension increases with age. Among others factors, increased oxidative stress is a well-recognized etiological factor for the development of hypertension. The co-occurrence of oxidative stress and hypertension may occur as a consequence of a decrease in antioxidant defense system activity or elevated reactive oxygen species generation. Glutathione is a major intracellular thiol-disulfide redox buffer that serves as a cofactor for many antioxidant enzymes. Glutathione-related parameters are altered in hypertension, suggesting that there is an association between the glutathione-related redox system and hypertension. In this review, we provide mechanistic explanations for how glutathione maintains blood pressure. More specifically, we discuss glutathione's role in combating oxidative stress and maintaining nitric oxide bioavailability via the formation of nitrosothiols and nitrosohemoglobin. Although impaired vasodilator responses are observed in S-nitrosothiol-deficient red blood cells, this potential hypertensive mechanism is currently overlooked in the literature. Here we fill in this gap by discussing the role of glutathione in nitric oxide metabolism and controlling blood pressure. We conclude that disturbances in glutathione metabolism might explain age-dependent increases in blood pressure. PMID:27511994

  14. Impact of reactive oxygen species on antioxidant capacity of male reproductive system.

    PubMed

    Riaz, Muhammad; Mahmood, Zahed; Shahid, Muhammad; Saeed, M Usman Qamar; Tahir, Imtiaz Mahmood; Shah, Sm Ali; Munir, Naveed; El-Ghorab, Ahmed

    2016-09-01

    The present research work was aimed to study the mutual interaction of reactive oxygen species (ROS) and basal cells antioxidant capacity in the male reproductive system and to further establish the association between selected heavy metals and stress markers. Total oxidant status (TOS) and total antioxidant status (TAS) of serum and seminal plasma were determined by automated photometric methods. The concentrations of Selenium (Se), Lead (Pb), and Cadmium (Cd) were determined by using atomic absorption spectrophotometer. The TOS was increased significantly (P <0.05) in seminal plasma as well as in the serum of the infertile group when compared with the fertile group. On the other hand, the TAS of the infertile group was found to be noticeably decreased (P <0.05) when compared with the TAS of the fertile group. Among the heavy metals, a noticeably lower concentration of Se was detected in the infertile group whereas markedly elevated levels of Cd and Pb were observed in the infertile group compared with the fertile group. Among the infertile group a significant inverse correlation (r = -0.521, P <0.05) was observed between Se and TOS and between Cd and Pb (r = -0.407, P <0.05). Contrarily among the infertile group a considerable positive relationship was established between Se and TAS (r = 0.507, P <0.05). It was concluded that the oxidant stress reduces the antioxidant activity in infertile men by elevating the production of ROS. A lower concentration of Se and elevated levels of Pb and Cd explain the individual's exposure to these heavy metals. The study also revealed that the heavy metal toxicity contributes significantly to male infertility. PMID:26684624

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

    PubMed

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

    2016-03-01

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

  16. Response of Daphnia's Antioxidant System to Spatial Heterogeneity in Cyanobacteria Concentrations in a Lowland Reservoir

    PubMed Central

    Wojtal-Frankiewicz, Adrianna; Bernasińska, Joanna; Frankiewicz, Piotr; Gwoździński, Krzysztof; Jurczak, Tomasz

    2014-01-01

    Many species and clones of Daphnia inhabit ecosystems with permanent algal blooms, and they can develop tolerance to cyanobacterial toxins. In the current study, we examined the spatial differences in the response of Daphnia longispina to the toxic Microcystis aeruginosa in a lowland eutrophic dam reservoir between June (before blooms) and September (during blooms). The reservoir showed a distinct spatial pattern in cyanobacteria abundance resulting from the wind direction: the station closest to the dam was characterised by persistently high Microcystis biomass, whereas the upstream stations had a significantly lower biomass of Microcystis. Microcystin concentrations were closely correlated with the cyanobacteria abundance (r = 0.93). The density of daphniids did not differ among the stations. The main objective of this study was to investigate how the distribution of toxic Microcystis blooms affects the antioxidant system of Daphnia. We examined catalase (CAT) activity, the level of the low molecular weight antioxidant glutathione (GSH), glutathione S-transferase (GST) activity and oxidative stress parameters, such as lipid peroxidation (LPO). We found that the higher the abundance (and toxicity) of the cyanobacteria, the lower the values of the antioxidant parameters. The CAT activity and LPO level were always significantly lower at the station with the highest M. aeruginosa biomass, which indicated the low oxidative stress of D. longispina at the site with the potentially high toxic thread. However, the low concentration of GSH and the highest activity of GST indicated the occurrence of detoxification processes at this site. These results demonstrate that daphniids that have coexisted with a high biomass of toxic cyanobacteria have effective mechanisms that protect them against the toxic effects of microcystins. We also conclude that Daphnia's resistance capacity to Microcystis toxins may differ within an ecosystem, depending on the bloom's spatial

  17. In Vivo Antioxidant Assays.

    PubMed

    2016-01-01

    Oxidative stress and antioxidant deficiency have been implicated in the pathophysiology of a wide range of diseases and conditions. Consequently, over recent years many different supplementation trials have been implemented, aimed at improving clinical outcomes by boosting antioxidant levels. These trials included supplementation with individual antioxidants, antioxidant combinations, and antioxidant-rich foods such as fruit and vegetable juices and other plant extracts. To ensure that data from these trials are interpreted correctly, it is essential that suitable biomarkers are used to assess changes in in vivo antioxidant activity resulting from supplementation. Therefore, the measurement of antioxidant systems, such as superoxide dismutase, catalase, glutathione reductase, and status of other molecules in biological fluids with their quantification methods are simplified in this chapter. PMID:26939271

  18. Oxidative DNA damage preventive activity and antioxidant potential of plants used in Unani system of medicine

    PubMed Central

    2010-01-01

    Background There is increasing recognition that many of today's diseases are due to the "oxidative stress" that results from an imbalance between the formation and neutralization of reactive molecules such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), which can be removed with antioxidants. The main objective of the present study was to evaluate the antioxidant activity of plants routinely used in the Unani system of medicine. Several plants were screened for radical scavenging activity, and the ten that showed promising results were selected for further evaluation. Methods Methanol (50%) extracts were prepared from ten Unani plants, namely Cleome icosandra, Rosa damascena, Cyperus scariosus, Gardenia gummifera, Abies pindrow, Valeriana wallichii, Holarrhena antidysenterica, Anacyclus pyrethrum, Asphodelus tenuifolius and Cyperus scariosus, and were used to determine their total phenolic, flavonoid and ascorbic acid contents, in vitro scavenging of DPPH·, ABTS·+, NO, ·OH, O2.- and ONOO-, and capacity to prevent oxidative DNA damage. Cytotoxic activity was also determined against the U937 cell line. Results IC50 values for scavenging DPPH·, ABTS·+, NO, ·OH, O2.- and ONOO- were in the ranges 0.007 ± 0.0001 - 2.006 ± 0.002 mg/ml, 2.54 ± 0.04 - 156.94 ± 5.28 μg/ml, 152.23 ± 3.51 - 286.59 ± 3.89 μg/ml, 18.23 ± 0.03 - 50.13 ± 0.04 μg/ml, 28.85 ± 0.23 - 537.87 ± 93 μg/ml and 0.532 ± 0.015 - 3.39 ± 0.032 mg/ml, respectively. The total phenolic, flavonoid and ascorbic acid contents were in the ranges 62.89 ± 0.43 - 166.13 ± 0.56 mg gallic acid equivalent (GAE)/g extract, 38.89 ± 0.52 - 172.23 ± 0.08 mg quercetin equivalent (QEE)/g extract and 0.14 ± 0.09 - 0.98 ± 0.21 mg AA/g extract. The activities of the different plant extracts against oxidative DNA damage were in the range 0.13-1.60 μg/ml. Of the ten selected plant extracts studied here, seven - C. icosandra, R. damascena, C. scariosus, G. gummifera, A. pindrow, V

  19. "Defence-in-Depth" Strategy in Transport Risk Management

    NASA Astrophysics Data System (ADS)

    Szymanek, Andrzej

    Safety management is a kind of system management, that is management by purposes. Taking "defence-in-depth" strategy, DDS - there can be defined four main aims and four method groups of risk management in transport: 1. minimizing transport accidents risk; 2. minimizing number of undesirable transport events (incidents, conflicts, collisions, accidents). Above purposes relate stages of safety management in transport. At each level of management should be elaborated methods, procedures and technologies of minimizing transport accidents risk. According to DDS any management system of transport safety should have a structure of multilevel chain protections which supervise main transport processes. About those problems in the paper.

  20. Toxic effects of nitenpyram on antioxidant enzyme system and DNA in zebrafish (Danio rerio) livers.

    PubMed

    Yan, Saihong; Wang, Jinhua; Zhu, Lusheng; Chen, Aimei; Wang, Jun

    2015-12-01

    Nitenpyram is one of the most commonly used neonicotinoid pesticide worldwide and was found to be toxic to non-target aquatic organisms. Therefore, the purpose of this study was to investigate the oxidative stress, changes in the detoxifying system and DNA damage in zebrafish induced by nitenpyram. In the present study, zebrafish (Danio rerio) were exposed to four concentrations (0.6, 1.2, 2.5, and 5.0 mg L(-1)) for 28 d and then sampled in triplicate on days 7, 14, 21 and 28. Superoxide dismutase (SOD) and catalase (CAT) activities were dramatically inhibited at most exposure times compared with the control group, except SOD at low concentration (0.6 mg L(-1)) of nitenpyram and CAT on day 21. This difference is due to the excess reactive oxygen species (ROS) produced and increased malondialdehyde (MDA) content in zebrafish livers. The activity of glutathione S-transferase (GST) increased in in the treatment groups at a higher concentration compared with the control group. We found that nitenpyram exposure could affect the antioxidant enzymes and DNA damage in the exposed zebrafish livers. Additionally, the changes in the antioxidant enzyme activities could be an adaptive response protecting against the toxicity induced by nitenpyram. PMID:26202306

  1. Intracellular Oxidant Activity, Antioxidant Enzyme Defense System, and Cell Senescence in Fibroblasts with Trisomy 21

    PubMed Central

    Rodríguez-Sureda, Víctor; Vilches, Ángel; Sánchez, Olga; Audí, Laura; Domínguez, Carmen

    2015-01-01

    Down's syndrome (DS) is characterized by a complex phenotype associated with chronic oxidative stress and mitochondrial dysfunction. Overexpression of genes on chromosome-21 is thought to underlie the pathogenesis of the major phenotypic features of DS, such as premature aging. Using cultured fibroblasts with trisomy 21 (T21F), this study aimed to ascertain whether an imbalance exists in activities, mRNA, and protein expression of the antioxidant enzymes SOD1, SOD2, glutathione-peroxidase, and catalase during the cell replication process in vitro. T21F had high SOD1 expression and activity which led to an interenzymatic imbalance in the antioxidant defense system, accentuated with replicative senescence. Intracellular ROS production and oxidized protein levels were significantly higher in T21F compared with control cells; furthermore, a significant decline in intracellular ATP content was detected in T21F. Cell senescence was found to appear prematurely in DS cells as shown by SA-β-Gal assay and p21 assessment, though not apoptosis, as neither p53 nor the proapoptotic proteins cytochrome c and caspase 9 were altered in T21F. These novel findings would point to a deleterious role of oxidatively modified molecules in early cell senescence of T21F, thereby linking replicative and stress-induced senescence in cultured cells to premature aging in DS. PMID:25852816

  2. Intracellular oxidant activity, antioxidant enzyme defense system, and cell senescence in fibroblasts with trisomy 21.

    PubMed

    Rodríguez-Sureda, Víctor; Vilches, Ángel; Sánchez, Olga; Audí, Laura; Domínguez, Carmen

    2015-01-01

    Down's syndrome (DS) is characterized by a complex phenotype associated with chronic oxidative stress and mitochondrial dysfunction. Overexpression of genes on chromosome-21 is thought to underlie the pathogenesis of the major phenotypic features of DS, such as premature aging. Using cultured fibroblasts with trisomy 21 (T21F), this study aimed to ascertain whether an imbalance exists in activities, mRNA, and protein expression of the antioxidant enzymes SOD1, SOD2, glutathione-peroxidase, and catalase during the cell replication process in vitro. T21F had high SOD1 expression and activity which led to an interenzymatic imbalance in the antioxidant defense system, accentuated with replicative senescence. Intracellular ROS production and oxidized protein levels were significantly higher in T21F compared with control cells; furthermore, a significant decline in intracellular ATP content was detected in T21F. Cell senescence was found to appear prematurely in DS cells as shown by SA-β-Gal assay and p21 assessment, though not apoptosis, as neither p53 nor the proapoptotic proteins cytochrome c and caspase 9 were altered in T21F. These novel findings would point to a deleterious role of oxidatively modified molecules in early cell senescence of T21F, thereby linking replicative and stress-induced senescence in cultured cells to premature aging in DS. PMID:25852816

  3. Alleviation of Antioxidant Defense System by Ozonized Olive Oil in DNBS-Induced Colitis in Rats

    PubMed Central

    Bayoumi, Fatehia A.; Ahmed, Naglaa G.

    2014-01-01

    The aim of the study was to evaluate the potential protective effect of ozonized olive oil (OZO) in 2,4-dinitrobenzene sulphuric acid (DNBS) induced colitis in rats and to elucidate the role of some antioxidant defense system (superoxide dismutase “SOD,” glutathione peroxidase “GSH-Px,” and catalase “CAT”) in these effects. The physicochemical parameters including viscosity, peroxide, and acid values of olive oil and OZO were evaluated. The animals were divided into several groups and the colitis was induced in the rats by intracolonic instillation of DNBS at dose of 15 mg/rat. Olive oil (OO) at dose of 6 mg/kg and OZO at doses of 3 and 6 mg/kg was administered orally for 7 days, starting the day before induction of colitis. Our results showed that macroscopic and microscopic damage scores were significantly reduced in a dose response manner in rats pretreated with OZO only. In contrast, CAT, GSH-Px, and SOD activities were significantly increased in the distal colon of inflamed animals pretreated with OZO with respect to control group dose dependently. Results demonstrate that OZO pretreatment exerts protective effects in DNBS induced colitis in rats and provide evidence that the protective effects of OZO are mediated by stimulation of some antioxidant enzymes. PMID:25276059

  4. Acclimation of Foliar Antioxidant Systems to Growth Irradiance in Three Broad-Leaved Evergreen Species.

    PubMed Central

    Grace, S. C.; Logan, B. A.

    1996-01-01

    The protective role of leaf antioxidant systems in the mechanism of plant acclimation to growth irradiance was studied in Vinca major, Schefflera arboricola, and Mahonia repens, which were grown for several months at 20, 100, and 1200 [mu]mol photons m-2 s-1. As growth irradiance increased, several constituents of the "Mehler-peroxidase" pathway also increased: superoxide dismutase, ascorbate peroxidase, glutathione reductase, ascorbate, and glutathione. This occurred concomitantly with increases in the xanthophyll cycle pool size and in the rate of nonphotochemical energy dissipation under steady-state conditions. There was no evidence for photosystem II overreduction in plants grown at high irradiance, although the reduction state of the stromal NADP pool, estimated from measurements of NADP-malate dehydrogenase activity, was greater than 60% in V. major and S. arboricola. Ascorbate, which removes reactive O2 species generated by O2 photoreduction in the chloroplast and serves as a reductant for the conversion of the xanthophyll cycle pigments to the de-epoxidized forms A plus Z, generally exhibited the most dramatic increases in response to growth irradiance. We conclude from these results that O2 photoreduction occurs at higher rates in leaves acclimated to high irradiance, despite increases in xanthophyll cycle-dependent energy dissipation, and that increases in leaf antioxidants protect against this potential oxidative stress. PMID:12226469

  5. Alleviation of antioxidant defense system by ozonized olive oil in DNBS-induced colitis in rats.

    PubMed

    Abu-Gharbieh, Eman; Bayoumi, Fatehia A; Ahmed, Naglaa G

    2014-01-01

    The aim of the study was to evaluate the potential protective effect of ozonized olive oil (OZO) in 2,4-dinitrobenzene sulphuric acid (DNBS) induced colitis in rats and to elucidate the role of some antioxidant defense system (superoxide dismutase "SOD," glutathione peroxidase "GSH-Px," and catalase "CAT") in these effects. The physicochemical parameters including viscosity, peroxide, and acid values of olive oil and OZO were evaluated. The animals were divided into several groups and the colitis was induced in the rats by intracolonic instillation of DNBS at dose of 15 mg/rat. Olive oil (OO) at dose of 6 mg/kg and OZO at doses of 3 and 6 mg/kg was administered orally for 7 days, starting the day before induction of colitis. Our results showed that macroscopic and microscopic damage scores were significantly reduced in a dose response manner in rats pretreated with OZO only. In contrast, CAT, GSH-Px, and SOD activities were significantly increased in the distal colon of inflamed animals pretreated with OZO with respect to control group dose dependently. Results demonstrate that OZO pretreatment exerts protective effects in DNBS induced colitis in rats and provide evidence that the protective effects of OZO are mediated by stimulation of some antioxidant enzymes. PMID:25276059

  6. Effects of dietary heavy metals on the immune and antioxidant systems of Galleria mellonella larvae.

    PubMed

    Wu, Gongqing; Yi, Yunhong

    2015-01-01

    In this work, we analyzed the effects of chromium (Cr) and lead (Pb) on immune and antioxidant systems of Galleria mellonella. In particular, after exposure to diets containing environmentally relevant concentrations (5, 50 and 100 μg/g) of Cr or Pb for 7 d, alterations in innate immune parameters and the activity of endogenous enzymes were measured in larvae. The results showed that 1) compared with the control, the lowest doses (5 μg/g) of Cr and Pb significantly increased the levels of innate immune parameters (total hemocyte count, THC; phagocytic activity; extent of encapsulation) of the larvae and hemolymph immune enzyme activities (acid phosphatase, ACP; alkaline phosphatase, AKP; phenoloxidase, PO), whereas the highest doses (100 μg/g) of Cr and Pb inhibited them; 2) the activity of antioxidant enzymes (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT) showed significant increases with increasing concentrations of dietary Cr and Pb, and were significantly higher than those of the control; and 3) feeding the larvae with experimental concentrations of either Cr or Pb resulted similar patterns of changes of all the parameters examined. The current study suggested that moderate amounts of Cr and Pb enhance the innate immunity of G. mellonella, but that large amounts led to the inhibition of larval immune function, and also indicated that the experimental concentrations of Cr and Pb used caused strong oxidative stresses in the larvae. PMID:25463648

  7. Modulation of Fibrosis in Systemic Sclerosis by Nitric Oxide and Antioxidants

    PubMed Central

    Dooley, Audrey; Bruckdorfer, K. Richard; Abraham, David J.

    2012-01-01

    Systemic sclerosis (scleroderma: SSc) is a multisystem, connective tissue disease of unknown aetiology characterized by vascular dysfunction, autoimmunity, and enhanced fibroblast activity resulting in fibrosis of the skin, heart, and lungs, and ultimately internal organ failure, and death. One of the most important and early modulators of disease activity is thought to be oxidative stress. Evidence suggests that the free radical nitric oxide (NO), a key mediator of oxidative stress, can profoundly influence the early microvasculopathy, and possibly the ensuing fibrogenic response. Animal models and human studies have also identified dietary antioxidants, such as epigallocatechin-3-gallate (EGCG), to function as a protective system against oxidative stress and fibrosis. Hence, targeting EGCG may prove a possible candidate for therapeutic treatment aimed at reducing both oxidant stress and the fibrotic effects associated with SSc. PMID:22111028

  8. Redox Homeostasis and Cellular Antioxidant Systems: Crucial Players in Cancer Growth and Therapy

    PubMed Central

    Ciucis, Chiara De

    2016-01-01

    Reactive oxygen species (ROS) and their products are components of cell signaling pathways and play important roles in cellular physiology and pathophysiology. Under physiological conditions, cells control ROS levels by the use of scavenging systems such as superoxide dismutases, peroxiredoxins, and glutathione that balance ROS generation and elimination. Under oxidative stress conditions, excessive ROS can damage cellular proteins, lipids, and DNA, leading to cell damage that may contribute to carcinogenesis. Several studies have shown that cancer cells display an adaptive response to oxidative stress by increasing expression of antioxidant enzymes and molecules. As a double-edged sword, ROS influence signaling pathways determining beneficial or detrimental outcomes in cancer therapy. In this review, we address the role of redox homeostasis in cancer growth and therapy and examine the current literature regarding the redox regulatory systems that become upregulated in cancer and their role in promoting tumor progression and resistance to chemotherapy. PMID:27418953

  9. Malaysian Defence and E-Learning

    ERIC Educational Resources Information Center

    Juhary, Jowati binti

    2005-01-01

    This paper begins with an analysis of the changing security scenario in the Asian region, with special focus on Malaysian defence strategies and foreign policies. Beginning in the mid 1990s, the Malaysian government shifted its attention away from the counter insurgency strategies of the early decades of independence to focus on wider questions of…

  10. The Man-in-the-Middle Defence

    NASA Astrophysics Data System (ADS)

    Anderson, Ross

    The man-in-the-middle defence is all about rehabilitating Charlie. For 20 years we’ve worried about this guy in the middle, Charlie, who’s forever intercalating himself into the communications between Alice and Bob, and people have been very judgemental about poor Charlie, saying that Charlie is a wicked person. Well, we’re not entirely convinced.

  11. In Defence of the Classroom Science Demonstration

    ERIC Educational Resources Information Center

    McCrory, Paul

    2013-01-01

    Science demonstrations are often criticised for their passive nature, their gratuitous exploitation and their limited ability to develop scientific knowledge and understanding. This article is intended to present a robust defence of the use of demonstrations in the classroom by identifying some of their unique and powerful benefits--practical,…

  12. Vitamins, stress and growth: the availability of antioxidants in early life influences the expression of cryptic genetic variation.

    PubMed

    Kim, S-Y; Noguera, J C; Tato, A; Velando, A

    2013-06-01

    Environmental inputs during early development can shape the expression of phenotypes, which has long-lasting consequences in physiology and life history of an organism. Here, we study whether experimentally manipulated availability of dietary antioxidants, vitamins C and E, influences the expression of genetic variance for antioxidant defence, endocrine signal and body mass in yellow-legged gull chicks using quantitative genetic models based on full siblings. Our experimental study in a natural population reveals that the expression of genetic variance in total antioxidant capacity in plasma increased in chicks supplemented with vitamins C and E despite the negligible effects on the average phenotype. This suggests that individuals differ in their ability to capture and transport dietary antioxidants or to respond to these extra resources, and importantly, this ability has a genetic basis. Corticosterone level in plasma and body mass were negatively correlated at the phenotypic level. Significant genetic variance of corticosterone level appeared only in control chicks nonsupplemented with vitamins, suggesting that the genetic variation of endocrine system, which transmits environmental cues to adaptively control chick development, appeared in stressful conditions (i.e. poor antioxidant availability). Therefore, environmental inputs may shape evolutionary trajectories of antioxidant capacity and endocrine system by affecting the expression of cryptic genetic variation. PMID:23517061

  13. Innate immune defences in the human endometrium

    PubMed Central

    King, Anne E; Critchley, Hilary OD; Kelly, Rodney W

    2003-01-01

    The human endometrium is an important site of innate immune defence, giving protection against uterine infection. Such protection is critical to successful implantation and pregnancy. Infection is a major cause of preterm birth and can also cause infertility and ectopic pregnancy. Natural anti-microbial peptides are key mediators of the innate immune system. These peptides, between them, have anti-bacterial, anti-fungal and anti-viral activity and are expressed at epithelial surfaces throughout the female genital tract. Two families of natural anti-microbials, the defensins and the whey acidic protein (WAP) motif proteins, appear to be prominent in endometrium. The human endometrial epithelium expresses beta-defensins 1–4 and the WAP motif protein, secretory leukocyte protease inhibitor. Each beta-defensin has a different expression profile in relation to the stage of the menstrual cycle, providing potential protection throughout the cycle. Secretory leukocyte protease inhibitor is expressed during the secretory phase of the cycle and has a range of possible roles including anti-protease and anti-microbial activity as well as having effects on epithelial cell growth. The leukocyte populations in the endometrium are also a source of anti-microbial production. Neutrophils are a particularly rich source of alpha-defensins, lactoferrin, lysozyme and the WAP motif protein, elafin. The presence of neutrophils during menstruation will enhance anti-microbial protection at a time when the epithelial barrier is disrupted. Several other anti-microbials including the natural killer cell product, granulysin, are likely to have a role in endometrium. The sequential production of natural anti-microbial peptides by the endometrium throughout the menstrual cycle and at other sites in the female genital tract will offer protection from many pathogens, including those that are sexually transmitted. PMID:14641912

  14. Antioxidant capacity of polychaetes occurring at a natural CO2 vent system: Results of an in situ reciprocal transplant experiment.

    PubMed

    Ricevuto, E; Benedetti, M; Regoli, F; Spicer, J I; Gambi, M C

    2015-12-01

    Ocean acidification (OA) is occurring at a fast rate, resulting in changes of carbonate chemistry in the oceans and in lowering of the pH. Previous studies have documented significant changes in the antioxidant defenses of marine species in response to OA. Here, selected polychaete species, Platynereis dumerilii, Polyophthalmus pictus and Syllis prolifera, were sampled from a natural CO2 vent system (pH = 7.3) and from a non-venting 'control' site (pH = 8.1), and reciprocally transplanted in these areas for 30 days. Total antioxidant capacity toward different forms of oxyradicals was compared in native and transplanted polychaetes: the aim was to assess whether the environmental conditions at the vent site would act as a prooxidant stressor, and the capability of polychaetes to modulate their antioxidant capacity to counteract a varied oxyradicals formation. None of the investigated species enhanced the antioxidant potential during the experiment. A significant reduction of the capability to neutralize different forms of oxyradicals was observed in P. pictus and, partially, in S. prolifera when transplanted from control to naturally-acidified conditions. On the other hand, populations of P. dumerilii originating from the vent and of S. prolifera from both control and acidified sites, showed higher constitutive antioxidant efficiency toward peroxyl radicals and peroxynitrite, which may allow them to cope with short-term and chronic exposure to higher oxidative pressure without further enhancement of antioxidant defenses. Since low pH - high pCO2 is the greatest environmental difference between the control and the vent sites, we suggest that the pro-oxidant challenge due to such peculiarities may have different biological consequences in different polychaete species. Some appear more susceptible to oxidative effects, while others acquire a long term acclimatization to vent conditions through the enhancement of their basal antioxidant protection. PMID:26392350

  15. Anthocyanins are potent antioxidants in model systems but do not reduce endogenous oxidative DNA damage in human colon cells.

    PubMed

    Pool-Zobel, B L; Bub, A; Schröder, N; Rechkemmer, G

    1999-10-01

    Anthocyanins are common colored plant flavonoids, occurring as glycosides of the respective anthocyanidin-chromophores. Like other flavonoids, anthocyanidins are also expected to have antioxidative and anti-mutagenic properties in vivo, although only few data are available. To gain more knowledge on possible protective mechanisms in mammalian cells, we have compared their extracellular and intracellular antioxidative potential in vitro and in human colon tumor cells. We used Aronia melanocarpa Elliot anthocyanin (AA) concentrates, fractions thereof, concentrates from Elderberry, Macqui, and Tintorera fruits, as well as pure compounds. In vitro, antioxidative properties of the samples were studied with the ferric reducing ability assay (FRA assay). As a measure of intracellular oxidative/antioxidative effects, H2O2-induced strand breaks as well as oxidized DNA bases were determined in human tumor HT29 clone 19A cells using a microgelelectrophoresis assay (comet test). Major results were that isolated compounds (aglycons and glycosides) and complex plant samples are powerful antioxidants in vitro. In fact their activities by far exceeded those of Trolox and vitamin C in the FRA assay. Also, H2O2-induced DNA strand breaks were reduced in cells treated with the complex plant extracts. In contrast, endogenous generation of oxidized DNA bases was not prevented. In summary, the intracellular steady state of oxidized DNA bases is not altered by anthocyanins or anthocyanidins. This finding raises questions with respect to the cancer preventive potential of anthocyanidins within specific tissues, such as the colon. Extracellularly, however, the compounds are potent antioxidants. This points to their potential for providing systemic protection in vivo, e.g., by scavenging oxidants in the blood stream and in the colon. Notably, both aglycons and glycosides have equally strong antioxidant activity. PMID:10654159

  16. Testing the optimal defence hypothesis for two indirect defences: extrafloral nectar and volatile organic compounds

    PubMed Central

    Radhika, Venkatesan; Kost, Christian; Bartram, Stefan; Heil, Martin

    2008-01-01

    Many plants respond to herbivory with an increased production of extrafloral nectar (EFN) and/or volatile organic compounds (VOCs) to attract predatory arthropods as an indirect defensive strategy. In this study, we tested whether these two indirect defences fit the optimal defence hypothesis (ODH), which predicts the within-plant allocation of anti-herbivore defences according to trade-offs between growth and defence. Using jasmonic acid-induced plants of Phaseolus lunatus and Ricinus communis, we tested whether the within-plant distribution pattern of these two indirect defences reflects the fitness value of the respective plant parts. Furthermore, we quantified photosynthetic rates and followed the within-plant transport of assimilates with 13C labelling experiments. EFN secretion and VOC emission were highest in younger leaves. Moreover, the photosynthetic rate increased with leaf age, and pulse-labelling experiments suggested transport of carbon to younger leaves. Our results demonstrate that the ODH can explain the within-plant allocation pattern of both indirect defences studied. PMID:18493790

  17. Light acclimation, retrograde signalling, cell death and immune defences in plants.

    PubMed

    Karpiński, Stanisław; Szechyńska-Hebda, Magdalena; Wituszyńska, Weronika; Burdiak, Paweł

    2013-04-01

    This review confronts the classical view of plant immune defence and light acclimation with recently published data. Earlier findings have linked plant immune defences to nucleotide-binding site leucine-rich repeat (NBS-LRR)-dependent recognition of pathogen effectors and to the role of plasma membrane-localized NADPH-dependent oxidoreductase (AtRbohD), reactive oxygen species (ROS) and salicylic acid (SA). However, recent results suggest that plant immune defence also depends on the absorption of excessive light energy and photorespiration. Rapid changes in light intensity and quality often cause the absorption of energy, which is in excess of that required for photosynthesis. Such excessive light energy is considered to be a factor triggering photoinhibition and disturbance in ROS/hormonal homeostasis, which leads to cell death in foliar tissues. We highlight here the tight crosstalk between ROS- and SA-dependent pathways leading to light acclimation, and defence responses leading to pathogen resistance. We also show that LESION SIMULATING DISEASE 1 (LSD1) regulates and integrates these processes. Moreover, we discuss the role of plastid-nucleus signal transduction, photorespiration, photoelectrochemical signalling and 'light memory' in the regulation of acclimation and immune defence responses. All of these results suggest that plants have evolved a genetic system that simultaneously regulates systemic acquired resistance (SAR), cell death and systemic acquired acclimation (SAA). PMID:23046215

  18. Hepatoprotective and Antioxidant Effects of Saponarin, Isolated from Gypsophila trichotoma Wend. on Paracetamol-Induced Liver Damage in Rats

    PubMed Central

    Vitcheva, Vessela; Kondeva-Burdina, Magdalena; Krasteva, Ilina; Manov, Vassil; Mitcheva, Mitka

    2013-01-01

    The hepatoprotective potential of saponarin, isolated from Gypsophila trichotoma, was evaluated in vitro/in vivo using a hepatotoxicity model of paracetamol-induced liver injury. In freshly isolated rat hepatocytes, paracetamol (100 μmol) led to a significant decrease in cell viability, increased LDH leakage, decreased levels of cellular GSH, and elevated MDA quantity. Saponarin (60–0.006 μg/mL) preincubation, however, significantly ameliorated paracetamol-induced hepatotoxicity in a concentration-dependent manner. The beneficial effect of saponarin was also observed in vivo. Rats were challenged with paracetamol alone (600 mg/kg, i.p.) and after 7-day pretreatment with saponarin (80 mg/kg, oral gavage). Paracetamol toxicity was evidenced by increase in MDA quantity and decrease in cell GSH levels and antioxidant defence system. No changes in phase I enzyme activities of AH and EMND and cytochrome P 450 quantity were detected. Saponarin pretreatment resulted in significant increase in cell antioxidant defence system and GSH levels and decrease in lipid peroxidation. The biochemical changes are in good correlation with the histopathological data. Protective activity of saponarin was similar to the activity of positive control silymarin. On the basis of these results, it can be concluded that saponarin exerts antioxidant and hepatoprotective activity against paracetamol liver injury in vitro/in vivo. PMID:23878818

  19. Effects of salinity and ascorbic acid on growth, water status and antioxidant system in a perennial halophyte

    PubMed Central

    Hameed, Abdul; Gulzar, Salman; Aziz, Irfan; Hussain, Tabassum; Gul, Bilquees; Khan, M. Ajmal

    2015-01-01

    Salinity causes oxidative stress in plants by enhancing production of reactive oxygen species, so that an efficient antioxidant system, of which ascorbic acid (AsA) is a key component, is an essential requirement of tolerance. However, antioxidant responses of plants to salinity vary considerably among species. Limonium stocksii is a sub-tropical halophyte found in the coastal marshes from Gujarat (India) to Karachi (Pakistan) but little information exists on its salt resistance. In order to investigate the role of AsA in tolerance, 2-month-old plants were treated with 0 (control), 300 (moderate) and 600 (high) mM NaCl for 30 days with or without exogenous application of AsA (20 mM) or distilled water. Shoot growth of unsprayed plants at moderate salinity was similar to that of controls while at high salinity growth was inhibited substantially. Sap osmolality, AsA concentrations and activities of AsA-dependant antioxidant enzymes increased with increasing salinity. Water spray resulted in some improvement in growth, indicating that the growth promotion by exogenous treatments could partly be attributed to water. However, exogenous application of AsA on plants grown under saline conditions improved growth and AsA dependent antioxidant enzymes more than the water control treatment. Our data show that AsA-dependent antioxidant enzymes play an important role in salinity tolerance of L. stocksii. PMID:25603966

  20. Effects of salinity and ascorbic acid on growth, water status and antioxidant system in a perennial halophyte.

    PubMed

    Hameed, Abdul; Gulzar, Salman; Aziz, Irfan; Hussain, Tabassum; Gul, Bilquees; Khan, M Ajmal

    2015-01-01

    Salinity causes oxidative stress in plants by enhancing production of reactive oxygen species, so that an efficient antioxidant system, of which ascorbic acid (AsA) is a key component, is an essential requirement of tolerance. However, antioxidant responses of plants to salinity vary considerably among species. Limonium stocksii is a sub-tropical halophyte found in the coastal marshes from Gujarat (India) to Karachi (Pakistan) but little information exists on its salt resistance. In order to investigate the role of AsA in tolerance, 2-month-old plants were treated with 0 (control), 300 (moderate) and 600 (high) mM NaCl for 30 days with or without exogenous application of AsA (20 mM) or distilled water. Shoot growth of unsprayed plants at moderate salinity was similar to that of controls while at high salinity growth was inhibited substantially. Sap osmolality, AsA concentrations and activities of AsA-dependant antioxidant enzymes increased with increasing salinity. Water spray resulted in some improvement in growth, indicating that the growth promotion by exogenous treatments could partly be attributed to water. However, exogenous application of AsA on plants grown under saline conditions improved growth and AsA dependent antioxidant enzymes more than the water control treatment. Our data show that AsA-dependent antioxidant enzymes play an important role in salinity tolerance of L. stocksii. PMID:25603966

  1. Application of Ultrasound in a Closed System: Optimum Condition for Antioxidants Extraction of Blackberry (Rubus fructicosus) Residues.

    PubMed

    Zafra-Rojas, Quinatzin Y; Cruz-Cansino, Nelly S; Quintero-Lira, Aurora; Gómez-Aldapa, Carlos A; Alanís-García, Ernesto; Cervantes-Elizarrarás, Alicia; Güemes-Vera, Norma; Ramírez-Moreno, Esther

    2016-01-01

    Blackberry processing generates up to 20% of residues composed mainly of peel, seeds and pulp that are abundant in flavonoids. The objective of this study was to optimize the ultrasound conditions, in a closed system, for antioxidants extraction, using the response surface methodology. Blackberry (Rubus fructicosus) residues were analyzed for total phenolics, total anthocyanins, and antioxidant activity by ABTS and DPPH. The selected independent variables were ultrasound amplitude (X₁: 80%-90%) and extraction time (X₂: 10-15 min), and results were compared with conventional extraction methods. The optimal conditions for antioxidants extraction were 91% amplitude for 15 min. The results for total phenolic content and anthocyanins and antioxidant activity by ABTS and DPPH were of 1201.23 mg gallic acid equivalent (GAE)/100 g dry weight basis (dw); 379.12 mg/100 g·dw; 6318.98 µmol Trolox equivalent (TE)/100 g·dw and 9617.22 µmol TE/100 g·dw, respectively. Compared to solvent extraction methods (water and ethanol), ultrasound achieved higher extraction of all compounds except for anthocyanins. The results obtained demonstrated that ultrasound is an alternative to improve extraction yield of antioxidants from fruit residues such as blackberry. PMID:27455210

  2. Alpha-lipoic acid protects against indomethacin-induced gastric oxidative toxicity by modulating antioxidant system.

    PubMed

    Kaplan, Kursat Ali; Odabasoglu, Fehmi; Halici, Zekai; Halici, Mesut; Cadirci, Elif; Atalay, Fadime; Aydin, Ozlem; Cakir, Ahmet

    2012-11-01

    Gastroprotective effects of α-lipoic acid (ALA) against oxidative gastric damage induced by indomethacin (IND) have been investigated. All doses (50, 75, 100, 150, 200, and 300 mg/kg body weight) of ALA reduced the ulcer index with 88.2% to 96.1% inhibition ratio. In biochemical analyses of stomach tissues, ALA administration decreased the level of lipid peroxidation (LPO) and activities of myeloperoxidase (MPO) and catalase (CAT) in gastric tissues, which were increased after IND application. ALA also increased the level of glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) that were decreased in gastric damaged stomach tissues. In conclusion, the gastroprotective effect of ALA could be attributed to its ameliorating effect on the antioxidant defense systems. PMID:23057764

  3. Eucalyptus tolerance mechanisms to lanthanum and cerium: subcellular distribution, antioxidant system and thiol pools.

    PubMed

    Shen, Yichang; Zhang, Shirong; Li, Sen; Xu, Xiaoxun; Jia, Yongxia; Gong, Guoshu

    2014-12-01

    Guanglin 9 (Eucalyptus grandis × Eucalyptus urophlla) and Eucalyptus grandis 5 are two eucalyptus species which have been found to grow normally in soils contaminated with lanthanum and cerium, but the tolerance mechanisms are not clear yet. In this study, a pot experiment was conducted to investigate the tolerance mechanisms of the eucalyptus to lanthanum and cerium. Cell walls stored 45.40-63.44% of the metals under lanthanum or cerium stress. Peroxidase and catalase activities enhanced with increasing soil La or Ce concentrations up to 200 mg kg(-1), while there were no obvious changes in glutathione and ascorbate concentrations. Non-protein thiols concentrations increased with increasing treatment levels up to 200 mg kg(-1), and then decreased. Phytochelatins concentrations continued to increase under La or Ce stress. Therefore, the two eucalyptus species are La and Ce tolerant plants, and the tolerance mechanisms include cell wall deposition, antioxidant system response, and thiol compound synthesis. PMID:25303462

  4. Evolution of behavioural and cellular defences against parasitoid wasps in the Drosophila melanogaster subgroup.

    PubMed

    Lynch, Z R; Schlenke, T A; de Roode, J C

    2016-05-01

    It may be intuitive to predict that host immune systems will evolve to counter a broad range of potential challenges through simultaneous investment in multiple defences. However, this would require diversion of resources from other traits, such as growth, survival and fecundity. Therefore, ecological immunology theory predicts that hosts will specialize in only a subset of possible defences. We tested this hypothesis through a comparative study of a cellular immune response and a putative behavioural defence used by eight fruit fly species against two parasitoid wasp species (one generalist and one specialist). Fly larvae can survive infection by melanotically encapsulating wasp eggs, and female flies can potentially reduce infection rates in their offspring by laying fewer eggs when wasps are present. The strengths of both defences varied significantly but were not negatively correlated across our chosen host species; thus, we found no evidence for a trade-off between behavioural and cellular immunity. Instead, cellular defences were significantly weaker against the generalist wasp, whereas behavioural defences were similar in strength against both wasps and positively correlated between wasps. We investigated the adaptive significance of wasp-induced oviposition reduction behaviour by testing whether wasp-exposed parents produce offspring with stronger cellular defences, but we found no support for this hypothesis. We further investigated the sensory basis of this behaviour by testing mutants deficient in either vision or olfaction, both of which failed to reduce their oviposition rates in the presence of wasps, suggesting that both senses are necessary for detecting and responding to wasps. PMID:26859227

  5. An Organ System Approach to Explore the Antioxidative, Anti-Inflammatory, and Cytoprotective Actions of Resveratrol

    PubMed Central

    Malhotra, Ashim; Bath, Sundeep; Elbarbry, Fawzy

    2015-01-01

    Resveratrol is a phenolic phytochemical, with a stilbene backbone, derived from edible plants such as grape and peanut. It is a bioactive molecule with physiological effects on multiple organ systems. Its effects range from the neuroprotective to the nephroprotective, including cardiovascular, neuronal, and antineoplastic responses as a part of its broad spectrum of action. In this review, we examine the effects of resveratrol on the following organ systems: the central nervous system, including neurological pathology such as Parkinson's and Alzheimer's disease; the cardiovascular system, including disorders such as atherosclerosis, ischemia-reperfusion injury, and cardiomyocyte hypertrophy; the kidneys, including primary and secondary nephropathies and nephrolithiasis; multiple forms of cancer; and metabolic syndromes including diabetes. We emphasize commonalities in extracellular matrix protein alterations and intracellular signal transduction system induction following resveratrol treatment. We summarize the known anti-inflammatory, antioxidative, and cytoprotective effects of resveratrol across disparate organ systems. Additionally, we analyze the available literature regarding the pharmacokinetics of resveratrol formulations used in these studies. Finally, we critically examine select clinical trials documenting a lack of effect following resveratrol treatment. PMID:26180596

  6. Rusi/Brassey's defence yearbook 1987 97th edition

    SciTech Connect

    Not Available

    1987-01-01

    This annual review of defence and strategic affairs provides an up-to-date survey of international strategic affairs, contemporary weapons and developments and future trends. For all those involved in defence studies, university and public libraries and the general public. Contents: The Year Ahead; The Middle East; NATO; The Soviet Union and Eastern Europe; UK defence policy; The Issues: What is SDI.; Will SDI help. A military view; SDI-the industrial implications; Conventional defence, a military view; An alternative view; European armaments cooperation; Terrorism; Sri Lanka: the Tamils; Israel 1986; The Iran/Iraq war; Arab view; South Africa; Chronology of conflict; Defence literature; Arms control; Nuclear weapons; Characteristics.

  7. Nano-jewels in biology. Gold and platinum on diamond nanoparticles as antioxidant systems against cellular oxidative stress.

    PubMed

    Martín, Roberto; Menchón, Cristina; Apostolova, Nadezda; Victor, Victor M; Alvaro, Mercedes; Herance, José Raúl; García, Hermenegildo

    2010-11-23

    Diamond nanoparticles (DNPs) obtained by explosive detonation have become commercially available. These commercial DNPs can be treated under Fenton conditions (FeSO(4) and H(2)O(2) at acidic pH) to obtain purer DNP samples with a small average particle size (4 nm) and a large population of surface OH groups (HO-DNPs). These Fenton-treated HO-DNPs have been used as a support of gold and platinum nanoparticles (≤2 nm average size). The resulting materials (Au/HO-DNP and Pt/HO-DNP) exhibit a high antioxidant activity against reactive oxygen species induced in a hepatoma cell line. In addition to presenting good biocompatibility, Au/HO- and Pt/HO-DNP exhibit about a two-fold higher antioxidant activity than glutathione, one of the reference antioxidant systems. The most active material against cellular oxidative stress was Au/HO-DNP. PMID:20939514

  8. Effect of canthaxanthin content of the maternal diet on the antioxidant system of the developing chick.

    PubMed

    Surai, A P; Surai, P F; Steinberg, W; Wakeman, W G; Speake, B K; Sparks, N H C

    2003-09-01

    1. Effects of canthaxanthin supplementation of the maternal diet on the antioxidant system of the developing chick were investigated. 2. Three hundred and twenty female broiler breeder birds were housed in one of 4 controlled environment rooms with 3 replicates for all treatments, with the exception of the control treatment of which there were 4 replicates. All birds received one of 5 diets: control low xanthophyll diet, or the same diet supplemented with 3, 6, 12 or 24 mg/kg canthaxanthin in the form of Carophyll Red. At 30 weeks of age 60 eggs from each of the 5 groups were incubated. At d 16 of the embryo development, at d 1 and d 7 posthatch tissue samples were collected and analysed by HPLC-based methods. 3. Canthaxanthin accumulation in the egg yolk was proportional to dietary content. Furthermore, at 12 to 24 mg/kg canthaxanthin was associated with an increase in gamma-tocopherol concentration in the egg yolk. Canthaxanthin was transferred from the egg yolk to the developing embryo and, as a result, its concentration in the liver of the embryo at 16 and in 1-d-old chicks was increased. Even at d 7 posthatch canthaxanthin concentration in the chicken liver was elevated. 4. Canthaxanthin supplementation of the maternal diet at 12 mg/kg was associated with an increased alpha-tocopherol concentration in the liver of 1-d-old chicks and resulted in decreased tissue susceptibility to lipid peroxidation. 5. Canthaxanthin supplementation at 6 to 24 mg/kg was also associated with a delay in alpha-tocopherol depletion from the liver for 7-d posthatch. As a result of the increased canthaxanthin and vitamin E concentrations in the liver of 7-d-old chicks, tissue susceptibility to lipid peroxidation decreased. 6. The results support an idea that dietary carotenoids can modulate antioxidant systems of the developing chicken. PMID:14584852

  9. TCDD and corticosterone on testicular steroidogenesis and antioxidant system of epididymal sperm in rats.

    PubMed

    Dhanabalan, S; Mathur, P P; Latha, P

    2015-09-01

    2,3,7,8-Tetrachloro dibenzo-p-dioxin (TCDD), an endocrine-disrupting environmental pollutant, has been found to cause male reproductive toxicity. Glucocorticoids have been found to influence the metabolic pathway of TCDD. Stress, which affects the male reproductive function, is marked by an increase in the level and activity of glucocorticoids in the body. The present study was carried out to understand the effect of TCDD on testicular steroidogenesis and sperm antioxidant system under the influence of increased level of corticosterone in the body. Adult male rats were treated with either TCDD (100 ng/kg bw/ day) or corticosterone (3 mg/kg bw/day) or both for 15 days. Treatment with either TCDD or corticosterone was found to suppress the levels of steroidogenic acute regulatory protein and androgen-binding protein and reduce the activities of steroidogenic enzymes in testis while increasing oxidative stress in ventral prostate, seminal vesicles and epididymal sperm. In rats treated with both TCDD and corticosterone, the suppression of testicular steroidogenesis and increase in oxidative stress observed in ventral prostate, seminal vesicles and epididymal sperm were significant as compared to TCDD alone treated rats. The levels of Fas and FasL proteins were also increased in rats subjected to either TCDD or corticosterone treatment. In rats treated with both compounds, the increase observed in testicular levels of Fas and FasL was significant as compared to TCDD alone treated rats. Effect of TCDD on testicular steroidogenesis and antioxidant system of epididymal sperm may get enhanced under increased level of glucocorticoids in the body. PMID:23363575

  10. Analysis of effects of a new environmental pollutant, bisphenol A, on antioxidant systems in soybean roots at different growth stages

    NASA Astrophysics Data System (ADS)

    Zhang, Jiazhi; Li, Xingyi; Zhou, Li; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-03-01

    Bisphenol A (BPA) is an important industrial raw material. Because of its widespread use and increasing release into environment, BPA has become a new environmental pollutant. Previous studies about BPA’s effects in plants focus on a certain growth stage. However, the plant’s response to pollutants varies at different growth stages. Therefore, in this work, BPA’s effects in soybean roots at different growth stages were investigated by determining the reactive oxygen species levels, membrane lipid fatty acid composition, membrane lipid peroxidation, and antioxidant systems. The results showed that low-dose BPA exposure slightly caused membrane lipid peroxidation but didn’t activate antioxidant systems at the seedling stage, and this exposure did not affect above process at other growth stages; high-dose BPA increased reactive oxygen species levels and then caused membrane lipid peroxidation at all growth stages although it activated antioxidant systems, and these effects were weaker with prolonging the growth stages. The recovery degree after withdrawal of BPA exposure was negatively related to BPA dose, but was positively related to growth stage. Taken together, the effects of BPA on antioxidant systems in soybean roots were associated with BPA exposure dose and soybean growth stage.

  11. Analysis of effects of a new environmental pollutant, bisphenol A, on antioxidant systems in soybean roots at different growth stages.

    PubMed

    Zhang, Jiazhi; Li, Xingyi; Zhou, Li; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-01-01

    Bisphenol A (BPA) is an important industrial raw material. Because of its widespread use and increasing release into environment, BPA has become a new environmental pollutant. Previous studies about BPA's effects in plants focus on a certain growth stage. However, the plant's response to pollutants varies at different growth stages. Therefore, in this work, BPA's effects in soybean roots at different growth stages were investigated by determining the reactive oxygen species levels, membrane lipid fatty acid composition, membrane lipid peroxidation, and antioxidant systems. The results showed that low-dose BPA exposure slightly caused membrane lipid peroxidation but didn't activate antioxidant systems at the seedling stage, and this exposure did not affect above process at other growth stages; high-dose BPA increased reactive oxygen species levels and then caused membrane lipid peroxidation at all growth stages although it activated antioxidant systems, and these effects were weaker with prolonging the growth stages. The recovery degree after withdrawal of BPA exposure was negatively related to BPA dose, but was positively related to growth stage. Taken together, the effects of BPA on antioxidant systems in soybean roots were associated with BPA exposure dose and soybean growth stage. PMID:27030053

  12. Analysis of effects of a new environmental pollutant, bisphenol A, on antioxidant systems in soybean roots at different growth stages

    PubMed Central

    Zhang, Jiazhi; Li, Xingyi; Zhou, Li; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-01-01

    Bisphenol A (BPA) is an important industrial raw material. Because of its widespread use and increasing release into environment, BPA has become a new environmental pollutant. Previous studies about BPA’s effects in plants focus on a certain growth stage. However, the plant’s response to pollutants varies at different growth stages. Therefore, in this work, BPA’s effects in soybean roots at different growth stages were investigated by determining the reactive oxygen species levels, membrane lipid fatty acid composition, membrane lipid peroxidation, and antioxidant systems. The results showed that low-dose BPA exposure slightly caused membrane lipid peroxidation but didn’t activate antioxidant systems at the seedling stage, and this exposure did not affect above process at other growth stages; high-dose BPA increased reactive oxygen species levels and then caused membrane lipid peroxidation at all growth stages although it activated antioxidant systems, and these effects were weaker with prolonging the growth stages. The recovery degree after withdrawal of BPA exposure was negatively related to BPA dose, but was positively related to growth stage. Taken together, the effects of BPA on antioxidant systems in soybean roots were associated with BPA exposure dose and soybean growth stage. PMID:27030053

  13. A novel in vitro whole plant system for analysis of polyphenolics and their antioxidant potential in cultivars of Ocimum basilicum.

    PubMed

    Srivastava, Shivani; Cahill, David M; Conlan, Xavier A; Adholeya, Alok

    2014-10-15

    Plants are an important source for medicinal compounds. Chemical screening and selection is critical for identification of compounds of interest. Ocimum basilicum (Basil) is a rich source of polyphenolics and exhibits high diversity, therefore bioprospecting of a suitable cultivar is a necessity. This study reports on the development of a true to type novel "in vitro system" and its comparison with a conventional system for screening and selection of cultivars for high total phenolics, individual polyphenolics, and antioxidant content. We have shown for the first time using online acidic potassium permanganate chemiluminescence that extracts from Ocimum basilicum showed antioxidant potential. The current study identified the cultivar specific composition of polyphenolics and their antioxidant properties. Further, a distinct relationship between plant morphotype and polyphenolic content was also found. Of the 15 cultivars examined, "Holy Green", "Red Rubin", and "Basil Genovese" were identified as high polyphenolic producing cultivars while "Subja" was determined to be a low producer. The "in vitro system" enabled differentiation of the cultivars in their morphology, polyphenolic content, and antioxidant activity and is a cheap and efficient method for bioprospecting studies. PMID:25275827

  14. Influence of chilling and heating stress on oxidative parameters and antioxidant systems in tomato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Tasti-Lee’ and ‘Sanibel’ tomatoes were chilled at 5 °C air for 4 day or heated at 52 °C water for 15 min. Oxidative parameters, antioxidant compounds and antioxidant-related enzymes in the tomatoes were measured immediately after treatment and four days after transfer to 20 °C. For ‘Tasti-Lee’, hea...

  15. Antioxidant potential of aqueous extract of some food grain powder in meat model system.

    PubMed

    Yogesh, K; Jha, S N; Ahmad, Tanbir

    2014-11-01

    In-vitro antioxidant activity of some food grains [sprouted mung bean (Vigna radiata), mung bean, sprouted chana (Cicer arietinum), chana, corn (Zea mays), methi (Trigonella foenum-graecum) and rajma (Phaseolus vulgaris)] powder extracts (FGE) was estimated by DPPH free radical scavenging activity (SA) method. Total phenolics and reducing power were also estimated in these extracts. The antioxidant potential of these extracts was also estimated in a meat model system. Total phenolics in FGE ranged from 66.9 ± 3.4 to 248.6 ± 11.1 mg TAE/gdw respectively which differed significantly (P < 0.01) among various groups. These extracts also showed remarkable DPPH radical scavenging activity (43.9 ± 1.1 % to 69.9 ± 2.9 %). The reducing powerOD700 was observed maximum (P < 0.01) in sprouted mung bean extract as compared to corn powder extract. The correlation between DPPH free radical SA v/s total phenolics was significant (P < 0.01) with R = 0.775. correlation between DPPH free radical SA v/s reducing power and total phenolics v/s reducing power was also significant (P < 0.01) with R value 0.907 and 0.682 respectively. FGE treated raw chicken breast meat showed better (P < 0.01) oxidative stability than control groups. PMID:26396344

  16. [Effects of ozone stress upon winter wheat photosynthesis, lipid peroxidation and antioxidant systems].

    PubMed

    Zheng, You-fei; Hu, Cheng-da; Wu, Rong-jun; Liu, Rui-na; Zhao, Ze; Zhang, Jin-en

    2010-07-01

    Stress effects of surface increased ozone concentration on winter wheat photosynthesis, lipid peroxidation and antioxidant systems in varied growth stages (jointing stage, booting stage, blooming stage and grain filling stage) were studied, the winter wheat was exposed to open top chambers (OTCs) in an open field conditions to three levels ozone concentrations (CK, 100 nmol x mol(-1), 150 nmol x mol(-1)). The results revealed that within 150 nmol x mol(-1) ozone concentration, as the ozone concentration and time increased,total chlorophyll content,chlorophyll a and b contents of winter wheat leaves were general declined,but compared to CK, the total chlorophyll and chlorophyll a content of T1 treatment groups were a little higher at booting and blooming stage; the conductance of stomatal was affected, the activation of unit leaf area decreased, intercellular CO2 concentration and stomatal limitation value showed a fluctuation change tendency. At the same time, a self-protective mechanism of winter wheat were launched. Concrete expression of SOD activity first increased rapidly and then gradually decreased, the activity of POD showed a decrease firstly and then rapidly increased. From the jointing stage to the blooming stage and from the grain filling stage one to grain filling stage two, the activity of CAT rapidly increased first and then comparatively decreased, but the content of MDA kept steadily rising. The carotenoid content increased first and then decreased, heat dissipation of unit leaf area increased. These results indicate that antioxidant enzymes can not completely eliminate excessive reactive oxygen species in vivo of winter wheat, then lead to accumulation of reactive oxygen species, further exacerbate the lipid peroxidation, that result in the increase of membrane permeability, degradation of chlorophyll, reduction of net photosynthetic rate, imposing on the winter wheat leaves senescence process. PMID:20825039

  17. Immune defence under extreme ambient temperature

    PubMed Central

    Seppälä, Otto; Jokela, Jukka

    2011-01-01

    Owing to global climate change, the extreme weather conditions are predicted to become more frequent, which is suggested to have an even greater impact on ecological interactions than the gradual increase in average temperatures. Here, we examined whether exposure to high ambient temperature affects immune function of the great pond snail (Lymnaea stagnalis). We quantified the levels of several immune traits from snails maintained in a non-stressful temperature (15°C) and in an extreme temperature (30°C) that occurs in small ponds during hot summers. We found that snails exposed to high temperature had weaker immune defence, which potentially predisposes them to infections. However, while phenoloxidase and antibacterial activity of snail haemolymph were reduced at high temperature, haemocyte concentration was not affected. This suggests that the effect of high temperature on snail susceptibility to infections may vary across different pathogens because different components of invertebrate immune defence have different roles in resistance. PMID:20610417

  18. Stereoselective Phytotoxicity of HCH Mediated by Photosynthetic and Antioxidant Defense Systems in Arabidopsis thaliana

    PubMed Central

    Zhang, Qiong; Zhou, Cong; Zhang, Quan; Qian, Haifeng; Liu, Weiping; Zhao, Meirong

    2013-01-01

    Background Hexachlorocyclohexane (HCH) has been used for plant protection and sanitation world-widely, and its isomers have been detected in water, soil, and air as well as in vegetation. As a sink for lipophilic pollutants, vegetation is very important for the degradation and fate of organic contamination; however, little was known about their phytotoxicity and mechanisms of toxic effect. In this study, the stereoselective phototoxicity of four isomers (α, β, γ, and δ) of HCHs mediated by independent as well as interconnecting systems of photosynthesis and enzymatic antioxidant defense system in Arabidopsis thaliana were assessed. Principal Findings Our results revealed that all the HCHs not only stimulated the activities of catalase (CAT) and peroxidase (POD), but also inhibited the activity of superoxide dismutase (SOD). In photosynthesis system, the photosynthetic efficiency of PSI and PSII were all down regulated. Meanwhile, results from both systems showed that δ-HCH was the most toxic one, while α-HCH the least in Arabidopsis thaliana. Conclusions For the first time, stereoselective effects of different isomers of HCH in plant were demonstrated. And the results suggest that it requires further research to fully elucidate the environmental toxicity and their mechanisms. PMID:23349669

  19. A thioredoxin reductase and/or thioredoxin system-based mechanism for antioxidant effects of ambroxol.

    PubMed

    Huang, Jin; Xu, Jianying; Tian, Lin; Zhong, Liangwei

    2014-02-01

    Long-term treatment with ambroxol (ABX), a bronchial expectorant, was found to prevent acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The underlying mechanism remains unclear. To address this, we have investigated the effect of ABX on critical antioxidant proteins thioredoxin (Trx) and thioredoxin reductase (TrxR) that are decreased in patients with AECOPD. Trx, TrxR and NADP(H) form Trx system, which is involved in regulating numerous oxidative stress-related events. In human bronchial epithelial cells, treatment with ABX from 0 to 200 μM gradually increased mRNA and protein levels of TrxR/Trx. At these ABX concentrations, TrxR activity was elevated progressively, whereas Trx activity exhibited a dose-dependent biphasic response, increasing at 50 and 75 μM, but decreasing at ABX over 150 μM. Pre-treatment with 75 μM ABX enhanced the capacity of the cells to eliminate reactive oxygen species, which was largely prevented by knockdown of cytosolic Trx (hTrx1). In a purified system, ABX shortened the initial lag phase during the reduction of insulin disulfide by Trx system. Pre-treatment of NADPH-reduced TrxR with ABX caused a dose- and time-dependent increase in thiolate/selenolate species, i.e. the catalytically active form of TrxR. Kinetic analysis demonstrated that the reduction of H2O2 by TrxR or Trx system were enhanced by 100 or 200 μM ABX. When hTrx1 was mixed with ABX in a molar ratio of 1:1 to 1:100 (which could occur in human plasma), changes in intrinsic Trp fluorescence occurred, and the response of reduced hTrx1 was especially remarkable. These data reveal an ABX-sensing mechanism of TrxR/Trx. We therefore conclude that the antioxidant actions of ABX at physiological concentrations are, at least partially, mediated by TrxR and/or Trx system. PMID:24103200

  20. Cultivated Sea Lettuce is a Multiorgan Protector from Oxidative and Inflammatory Stress by Enhancing the Endogenous Antioxidant Defense System

    PubMed Central

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

    2013-01-01

    The health-promoting effects of seaweeds have been linked to antioxidant activity that may counteract cancer-causing oxidative stress-induced damage and inflammation. While 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 demonstrated that Nrf2 and PI3 kinase 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. PMID:24005795

  1. Leaf Colour as a Signal of Chemical Defence to Insect Herbivores in Wild Cabbage (Brassica oleracea)

    PubMed Central

    Wilkins, Lucas; Osorio, Daniel; Hartley, Susan E.

    2015-01-01

    Leaf colour has been proposed to signal levels of host defence to insect herbivores, but we lack data on herbivory, leaf colour and levels of defence for wild host populations necessary to test this hypothesis. Such a test requires measurements of leaf spectra as they would be sensed by herbivore visual systems, as well as simultaneous measurements of chemical defences and herbivore responses to leaf colour in natural host-herbivore populations. In a large-scale field survey of wild cabbage (Brassica oleracea) populations, we show that variation in leaf colour and brightness, measured according to herbivore spectral sensitivities, predicts both levels of chemical defences (glucosinolates) and abundance of specialist lepidopteran (Pieris rapae) and hemipteran (Brevicoryne brassicae) herbivores. In subsequent experiments, P. rapae larvae achieved faster growth and greater pupal mass when feeding on plants with bluer leaves, which contained lower levels of aliphatic glucosinolates. Glucosinolate-mediated effects on larval performance may thus contribute to the association between P. rapae herbivory and leaf colour observed in the field. However, preference tests found no evidence that adult butterflies selected host plants based on leaf coloration. In the field, B. brassicae abundance varied with leaf brightness but greenhouse experiments were unable to identify any effects of brightness on aphid preference or performance. Our findings suggest that although leaf colour reflects both levels of host defences and herbivore abundance in the field, the ability of herbivores to respond to colour signals may be limited, even in species where performance is correlated with leaf colour. PMID:26353086

  2. Synergistic effects of direct and indirect defences on herbivore egg survival in a wild crucifer

    PubMed Central

    Fatouros, Nina E.; Pineda, Ana; Huigens, Martinus E.; Broekgaarden, Colette; Shimwela, Methew M.; Figueroa Candia, Ilich A.; Verbaarschot, Patrick; Bukovinszky, Tibor

    2014-01-01

    Evolutionary theory of plant defences against herbivores predicts a trade-off between direct (anti-herbivore traits) and indirect defences (attraction of carnivores) when carnivore fitness is reduced. Such a trade-off is expected in plant species that kill herbivore eggs by exhibiting a hypersensitive response (HR)-like necrosis, which should then negatively affect carnivores. We used the black mustard (Brassica nigra) to investigate how this potentially lethal direct trait affects preferences and/or performances of specialist cabbage white butterflies (Pieris spp.), and their natural enemies, tiny egg parasitoid wasps (Trichogramma spp.). Both within and between black mustard populations, we observed variation in the expression of Pieris egg-induced HR. Butterfly eggs on plants with HR-like necrosis suffered lower hatching rates and higher parasitism than eggs that did not induce the trait. In addition, Trichogramma wasps were attracted to volatiles of egg-induced plants that also expressed HR, and this attraction depended on the Trichogramma strain used. Consequently, HR did not have a negative effect on egg parasitoid survival. We conclude that even within a system where plants deploy lethal direct defences, such defences may still act with indirect defences in a synergistic manner to reduce herbivore pressure. PMID:25009068

  3. Synergistic effects of direct and indirect defences on herbivore egg survival in a wild crucifer.

    PubMed

    Fatouros, Nina E; Pineda, Ana; Huigens, Martinus E; Broekgaarden, Colette; Shimwela, Methew M; Figueroa Candia, Ilich A; Verbaarschot, Patrick; Bukovinszky, Tibor

    2014-08-22

    Evolutionary theory of plant defences against herbivores predicts a trade-off between direct (anti-herbivore traits) and indirect defences (attraction of carnivores) when carnivore fitness is reduced. Such a trade-off is expected in plant species that kill herbivore eggs by exhibiting a hypersensitive response (HR)-like necrosis, which should then negatively affect carnivores. We used the black mustard (Brassica nigra) to investigate how this potentially lethal direct trait affects preferences and/or performances of specialist cabbage white butterflies (Pieris spp.), and their natural enemies, tiny egg parasitoid wasps (Trichogramma spp.). Both within and between black mustard populations, we observed variation in the expression of Pieris egg-induced HR. Butterfly eggs on plants with HR-like necrosis suffered lower hatching rates and higher parasitism than eggs that did not induce the trait. In addition, Trichogramma wasps were attracted to volatiles of egg-induced plants that also expressed HR, and this attraction depended on the Trichogramma strain used. Consequently, HR did not have a negative effect on egg parasitoid survival. We conclude that even within a system where plants deploy lethal direct defences, such defences may still act with indirect defences in a synergistic manner to reduce herbivore pressure. PMID:25009068

  4. An inducible morphological defence is a passive by-product of behaviour in a marine snail

    PubMed Central

    Bourdeau, Paul E.

    2010-01-01

    Many organisms have evolved inducible defences in response to spatial and temporal variability in predation risk. These defences are assumed to incur large costs to prey; however, few studies have investigated the mechanisms and costs underlying these adaptive responses. I examined the proximate cause of predator-induced shell thickening in a marine snail (Nucella lamellosa) and tested whether induced thickening leads to an increase in structural strength. Results indicate that although predators (crabs) induce thicker shells, the response is a passive by-product of reduced feeding and somatic growth rather than an active physiological response to predation risk. Physical tests indicate that although the shells of predator-induced snails are significantly stronger, the increase in performance is no different than that of snails with limited access to food. Increased shell strength is attributable to an increase in the energetically inexpensive microstructural layer rather than to material property changes in the shell. This mechanism suggests that predator-induced shell defences may be neither energetically nor developmentally costly. Positive correlations between antipredator behaviour and morphological defences may explain commonly observed associations between growth reduction and defence production in other systems and could have implications for the evolutionary potential of these plastic traits. PMID:19846462

  5. The Man-in-the-Middle Defence

    NASA Astrophysics Data System (ADS)

    Anderson, Ross; Bond, Mike

    Eliminating middlemen from security protocols helps less than one would think. EMV electronic payments, for example, can be made fairer by adding an electronic attorney - a middleman which mediates access to a customer’s card. We compare middlemen in crypto protocols and APIs with those in the real world, and show that a man-in-the-middle defence is helpful in many circumstances. We suggest that the middleman has been unfairly demonised.

  6. The problem of missile defence

    NASA Astrophysics Data System (ADS)

    Webber, Philip

    2014-05-01

    The idea of building a missile system to defend a nation from the horrors of nuclear attack first entered the public consciousness in the 1980s, when US president Ronald Reagan - backed by prominent (and controversial) scientific advisers such as the physicist Edward Teller - promoted the Strategic Defense Initiative as a supposedly impenetrable shield against the Soviet Union's nuclear arsenal.

  7. Reproducing butterflies do not increase intake of antioxidants when they could benefit from them.

    PubMed

    Beaulieu, Michaël; Bischofberger, Ines; Lorenz, Isabel; Scheelen, Lucie; Fischer, Klaus

    2016-02-01

    The significance of dietary antioxidants may be limited by the ability of animals to exploit them. However, past studies have focused on the effects of dietary antioxidants after 'antioxidant forced-feeding', and have overlooked spontaneous antioxidant intake. Here, we found that reproducing female Bicyclus anynana butterflies had higher antioxidant defences and enhanced fecundity when forced to consume antioxidants (polyphenols). Interestingly, these positive effects were not constant across the oviposition period. When given the choice between food resources with and without antioxidants, reproducing butterflies did not target antioxidants when they could have benefited the most from them. Moreover, they did not consume more antioxidants than non-reproducing butterflies. These results emphasize that, despite potential positive effects of dietary antioxidants, the ability of animals to exploit them is likely to restrict their ecological significance. PMID:26911341

  8. Influence of genotype, cultivation system and irrigation regime on antioxidant capacity and selected phenolics of blueberries (Vaccinium corymbosum L.).

    PubMed

    Cardeñosa, Vanessa; Girones-Vilaplana, Amadeo; Muriel, José Luis; Moreno, Diego A; Moreno-Rojas, José M

    2016-07-01

    Demand for and availability of blueberries has increased substantially over recent years, driven in part by their health-promoting properties. Three blueberry varieties ('Rocío', V2, and V3) were grown under two cultivation systems (open-field and plastic tunnels) and subjected to two irrigations regimes (100% and 80% of crop evapotranspiration) in two consecutive years (2011-2012). They were evaluated for their phytochemical composition and antioxidant capacity. Genotype influenced the antioxidant capacity and the content of the three groups of phenolics in the blueberries. The antioxidant activity and total flavonols content increased when the blueberries were grown under open-field conditions. Deficit irrigation conditions led to additional positive effects on their phenolics (delphinidn-3-acetilhexoside content was increased under plastic tunnel with deficit irrigation). In conclusion, the amount of phenolic compounds and the antioxidant capacity of blueberries were not negatively affected by water restriction; Moreover, several changes were recorded due to growing system and genotype. PMID:26920295

  9. Effective activation of antioxidant system by immune-relevant factors reversely correlates with apoptosis of Eisenia andrei coelomocytes.

    PubMed

    Homa, J; Stalmach, M; Wilczek, G; Kolaczkowska, E

    2016-05-01

    Oxidative stress is harmful to the microbes but also to the host, and may result in bystander damage or death. Because of this, respiratory burst triggered in phagocytes by pathogens is counteracted by production of antioxidative factors. The aim of this work was to examine effectiveness of the latter system in earthworms Eisenia andrei by induction of reactive oxygen species, lipofuscin and phenoloxidase by natural (LPS, zymosan, Micrococus luteus) and synthetic (phorbol ester, PMA) stimulants. The compounds impaired numbers, viability (increased apoptosis) and composition of coelomocytes, and triggered the antioxidant activity of catalase and selenium-dependent glutathione peroxidase. The natural pathogenic compounds, unlike PMA, strongly activated antioxidative responses that diminished cell apoptosis. Moreover, repeated exposure to the same or different pathogenic compounds did not induce respiratory burst exhausted phenotype showing that coelomocytes are constantly at bay to withstand numerous infections. The current study reveals importance and efficiency of the oxidative-antioxidative systems in annelids but also confirms its evolutionary conservatism and complexity even in lower taxa of the animal kingdom. PMID:26922789

  10. Evaluation of the total antioxidant capacity by using a multipumping flow system with chemiluminescent detection.

    PubMed

    Meneses, Silvia R P; Marques, Karine L; Pires, Cherrine K; Santos, João L M; Fernandes, Eduarda; Lima, José L F C; Zagatto, Elias A G

    2005-10-01

    An automated flow-based procedure for assessment of total antioxidant capacity was developed. It involved a multipumping flow system, a recent approach to flow analysis, and exploited the ability of selected compounds to inhibit the chemiluminescence reactions of luminol or lucigenin with hydrogen peroxide. The system included several discretely actuated solenoid micropumps as the only active components of the flow manifold. This enabled the reproducible insertion and efficient mixing of very low volumes of sample and reagents as well as the transportation of the sample zone toward a flow-through luminometer, where the chemiluminometric response was monitored. With luminol as the chemiluminogenic reagent, linearity of the analytical curves was noted up to 3.2x10(-4), 1.1x10(-3), and 8.8x10(-8) molL-1 for Trolox, ascorbic acid, and resveratrol, respectively. With lucigenin, linear calibration plots up to 2x10(-5) molL-1 of Trolox and 5.7x10(-5)molL-1 of ascorbic acid were obtained. As favorable analytical figures of merit, the measurement precision (RSD typically between 0.2 and 2.0%, n=10), low operational costs, low reagent consumption, sampling rate (160 and 70 h-1), and versatility should be highlighted. The proposed system can be used in distinct analytical circumstances without requiring physical reconfiguration. PMID:16125130

  11. Microstructured fibres: a positive impact on defence technology?

    NASA Astrophysics Data System (ADS)

    O'Driscoll, E. J.; Watson, M. A.; Delmonte, T.; Petrovich, M. N.; Feng, X.; Flanagan, J. C.; Hayes, J. R.; Richardson, D. J.

    2006-09-01

    In this paper we seek to assess the potential impact of microstructured fibres for security and defence applications. Recent literature has presented results on using microstructured fibre for delivery of high power, high quality radiation and also on the use of microstructured fibre for broadband source generation. Whilst these two applications may appear contradictory to one another the inherent design flexibility of microstructured fibres allows fibres to be fabricated for the specific application requirements, either minimising (for delivery) or maximising (for broadband source generation) the nonlinear effects. In platform based laser applications such as infrared counter measures, remote sensing and laser directed-energy weapons, a suitable delivery fibre providing high power, high quality light delivery would allow a laser to be sited remotely from the sensor/device head. This opens up the possibility of several sensor/device types sharing the same multi-functional laser, thus reducing the complexity and hence the cost of such systems. For applications requiring broadband source characteristics, microstructured fibres can also offer advantages over conventional sources. By exploiting the nonlinear effects it is possible to realise a multifunctional source for applications such as active hyperspectral imaging, countermeasures, and biochemical sensing. These recent results suggest enormous potential for these novel fibre types to influence the next generation of photonic systems for security and defence applications. However, it is important to establish where the fibres can offer the greatest advantages and what research still needs to be done to drive the technology towards real platform solutions.

  12. Development of different comprehensive two dimensional systems for the separation of phenolic antioxidants.

    PubMed

    Cacciola, Francesco; Jandera, Pavel; Blahová, Eva; Mondello, Luigi

    2006-11-01

    Three different comprehensive 2-D HPLC systems for the separation of phenolic antioxidants have been developed on the basis of different selectivities of a PEG-silica column in the first dimension and a packed or monolithic C18 or a ZR-CARBON column, respectively, in the second dimension. Two-dimensional comprehensive liquid chromatography using a serially connected short PEG-silica column and a conventional C18-silica or a ZR-CARBON column in the second dimension was tested to improve the resolution of the earlier eluting compounds in the first dimension. Various types of interface were used to connect the columns in the first and in the second dimension: i) two injection sampling loops of 100 microL in conventional arrangement; ii) a 10-port 2-position valve equipped with two trapping X-Terra columns instead of loops; and iii) two analytical D2 columns in parallel. The mobile phase in the first dimension has a lower elution strength than in the second dimension, allowing band compression of the solutes transferred from the first to the second dimension. This effect was enhanced using trapping columns instead of sampling loops as the interface between the two dimensions, thus allowing a decrease in the time of analysis. These systems were used for the analysis of beer samples. The relative location of the components in the 2-D retention plane varied in relation to their chemical structure in each instrumental set-up and allowed positive peak identification. PMID:17154131

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

    PubMed

    Iskra, R Ia; Vlizlo, V V

    2013-01-01

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

  14. Altered Antioxidant System Stimulates Dielectric Barrier Discharge Plasma-Induced Cell Death for Solid Tumor Cell Treatment

    PubMed Central

    Park, Daehoon; Choi, Eun H.

    2014-01-01

    This study reports the experimental findings and plasma delivery approach developed at the Plasma Bioscience Research Center, Korea for the assessment of antitumor activity of dielectric barrier discharge (DBD) for cancer treatment. Detailed investigation of biological effects occurring after atmospheric pressure non-thermal (APNT) plasma application during in vitro experiments revealed the role of reactive oxygen species (ROS) in modulation of the antioxidant defense system, cellular metabolic activity, and apoptosis induction in cancer cells. To understand basic cellular mechanisms, we investigated the effects of APNT DBD plasma on antioxidant defense against oxidative stress in various malignant cells as well as normal cells. T98G glioblastoma, SNU80 thyroid carcinoma, KB oral carcinoma and a non-malignant HEK293 embryonic human cell lines were treated with APNT DBD plasma and cellular effects due to reactive oxygen species were observed. Plasma significantly decreased the metabolic viability and clonogenicity of T98G, SNU80, KB and HEK293 cell lines. Enhanced ROS in the cells led to death via alteration of total antioxidant activity, and NADP+/NADPH and GSH/GSSG ratios 24 hours (h) post plasma treatment. This effect was confirmed by annexin V-FITC and propidium iodide staining. These consequences suggested that the failure of antioxidant defense machinery, with compromised redox status, might have led to sensitization of the malignant cells. These findings suggest a promising approach for solid tumor therapy by delivering a lethal dose of APNT plasma to tumor cells while sparing normal healthy tissues. PMID:25068311

  15. Purification and in vitro antioxidative effects of giant squid muscle peptides on free radical-mediated oxidative systems.

    PubMed

    Rajapakse, Niranjan; Mendis, Eresha; Byun, Hee-Guk; Kim, Se-Kwon

    2005-09-01

    Low molecular weight peptides obtained from ultrafiltration (UF) of giant squid (Dosidicus gigas) muscle protein were studied for their antioxidative effects in different in vitro oxidative systems. The most potent two peptides, Asn-Ala-Asp-Phe-Gly-Leu-Asn-Gly-Leu-Glu-Gly-Leu-Ala (1307 Da) and Asn-Gly-Leu-Glu-Gly-Leu-Lys (747 Da), exhibited their antioxidant potential to act as chain-breaking antioxidants by inhibiting radical-mediated peroxidation of linoleic acid, and their activities were closer to highly active synthetic antioxidant, butylated hydroxytoluene. Addition of these peptides could enhance the viability of cytotoxic embryonic lung fibroblasts significantly (P<.05) at a low concentration of 50 microg/ml, and it was presumed due to the suppression of radical-induced oxidation of membrane lipids. Electron spin trapping studies revealed that the peptides were potent scavengers of free radicals in the order of carbon-centered (IC(50) 396.04 and 304.67 microM), hydroxyl (IC(50) 497.32 and 428.54 microM) and superoxide radicals (IC(50) 669.34 and 573.83 microM). Even though the exact molecular mechanism for scavenging of free radicals was unclear, unusually high hydrophobic amino acid composition (more than 75%) of giant squid muscle peptides was presumed to be involved in the observed activities. PMID:16115545

  16. Programmable flow system for automation of oxygen radical absorbance capacity assay using pyrogallol red for estimation of antioxidant reactivity.

    PubMed

    Ramos, Inês I; Gregório, Bruno J R; Barreiros, Luísa; Magalhães, Luís M; Tóth, Ildikó V; Reis, Salette; Lima, José L F C; Segundo, Marcela A

    2016-04-01

    An automated oxygen radical absorbance capacity (ORAC) method based on programmable flow injection analysis was developed for the assessment of antioxidant reactivity. The method relies on real time spectrophotometric monitoring (540 nm) of pyrogallol red (PGR) bleaching mediated by peroxyl radicals in the presence of antioxidant compounds within the first minute of reaction, providing information about their initial reactivity against this type of radicals. The ORAC-PGR assay under programmable flow format affords a strict control of reaction conditions namely reagent mixing, temperature and reaction timing, which are critical parameters for in situ generation of peroxyl radical from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). The influence of reagent concentrations and programmable flow conditions on reaction development was studied, with application of 37.5 µM of PGR and 125 mM of AAPH in the flow cell, guaranteeing first order kinetics towards peroxyl radicals and pseudo-zero order towards PGR. Peroxyl-scavenging reactivity of antioxidants, bioactive compounds and phenolic-rich beverages was estimated employing the proposed methodology. Recovery assays using synthetic saliva provided values of 90 ± 5% for reduced glutathione. Detection limit calculated using the standard antioxidant compound Trolox was 8 μM. RSD values were <3.4 and <4.9%, for intra and inter-assay precision, respectively. Compared to previous batch automated ORAC assays, the developed system also accounted for high sampling frequency (29 h(-1)), low operating costs and low generation of waste. PMID:26838448

  17. Synthesis of triphenylphosphonium vitamin E derivatives as mitochondria-targeted antioxidants

    PubMed Central

    Jameson, Victoria J.A.; Cochemé, Helena M.; Logan, Angela; Hanton, Lyall R.; Smith, Robin A.J.; Murphy, Michael P.

    2015-01-01

    A series of mitochondria-targeted antioxidants comprising a lipophilic triphenylphosphonium cation attached to the antioxidant chroman moiety of vitamin E by an alkyl linker have been prepared. The synthesis of a series of mitochondria-targeted vitamin E derivatives with a range of alkyl linkers gave compounds of different hydrophobicities. This work will enable the dependence of antioxidant defence on hydrophobicity to be determined in vivo. PMID:26549895

  18. Investigations of host defence in patients with sickle cell disease.

    PubMed

    Boghossian, S H; Wright, G; Webster, A D; Segal, A W

    1985-03-01

    Parameters of host defence were investigated in 30 patients with sickle cell disease (SCD). A newly devised perfusion system was used to study the kinetics in whole blood of leucocyte adherence, phagocytosis, killing and solubilization of a mixture of Staph. aureus and Str. pneumoniae, and secretion of lactoferrin. A skin window technique was used to examine the accumulation of leucocytes at inflammatory foci and their subsequent rate of movement through a filter. Serum concentrations of C3, C4, total haemolytic complement and immunoglobulins were also measured. The rate of neutrophil migration into filters was slightly reduced in patients with SCD. The proportion of monocytes that emigrated from the skin windows and their rate of migration were markedly diminished. The adhesion of neutrophils and their ability to kill staphylococci were also reduced, particularly in patients of the haemoglobin (Hb) SS and Hb S-beta-thalassaemia genotypes. Neutrophil function was mostly impaired in patients with the greatest frequency of bacterial infection. The rate of clearance of pneumococci was related to the concentration of type specific immunoglobulin G but not M. Serum concentrations of immunoglobulins and complement were normal. We were unable to define a defect of host defence of sufficient magnitude to explain the susceptibility of these patients to severe infection. PMID:3882140

  19. Effects of lutein or lutein in combination with vitamin C on mRNA expression and activity of antioxidant enzymes and status of the antioxidant system in SD rats

    PubMed Central

    Song, Min-Hae; Shin, Eu-Chul; Hwang, Dae-Youn

    2015-01-01

    This study was conducted to investigate the effects of lutein alone or in combination with vitamin C on the antioxidant defense system in rats. A total of 18 eight-week-old male Sprague Dawley (SD) rats were randomly assigned to three groups for 4 weeks: control (CON), lutein (LUT, 50 mg lutein/kg BW) and lutein plus vitamin C (LVC, 50 mg lutein/kg BW+1,000 mg vitamin C/kg BW). No differences in body weight, relative live weight or plasma biochemical profiles were observed among treatment groups. In the hepatic antioxidant defense systems, the mRNA expression of superoxide dismutase (SOD) in the LUT and LVC groups was significantly (P<0.05) higher than that in the CON group, whereas the mRNA level of glutathione peroxidase (GPX), catalase (CAT) and glutathione S-transferase (GST) was not affected by the administration of antioxidants. SOD and GST activities in the LUT and LVC groups were significantly higher (P<0.05) than those in the CON group, whereas GPX, CAT and lipid peroxidation did not differ among groups. In addition, the LVC group showed a significant (P<0.05) increase in plasma and hepatic total antioxidant power (TAP) relative to the CON group. Overall, administration of lutein in combination with vitamin C improved the status of the total antioxidant defense system in SD rats. PMID:26472964

  20. Antioxidants in Central Nervous System Diseases: Preclinical Promise and Translational Challenges

    PubMed Central

    Kamat, Chandrashekhar D.; Gadal, Sunyana; Mhatre, Molina; Williamson, Kelly S.; Pye, Quentin N.; Hensley, Kenneth

    2009-01-01

    Oxidative damage is strongly implicated in the pathogenesis of neurodegenerative diseases including Alzheimer’s disease, amyotrophic lateral sclerosis, Huntington’s disease, Parkinson’s disease and stroke (brain ischemia/reperfusion injury). The availability of transgenic and toxin-inducible models of these conditions has facilitated the preclinical evaluation of putative antioxidant agents ranging from prototypic natural antioxidants such as vitamin E (α-tocopherol) to sophisticated synthetic free radical traps and catalytic oxidants. Literature review shows that antioxidant therapies have enjoyed general success in preclinical studies across disparate animal models, but little benefit in human intervention studies or clinical trials. Recent high-profile failures of vitamin E trials in Parkinson’s disease, and nitrone therapies in stroke, have diminished enthusiasm to pursue antioxidant neuroprotectants in the clinic. The translational disappointment of antioxidants likely arises from a combination of factors including failure to understand the drug candidate’s mechanism of action in relationship to human disease, and failure to conduct preclinical studies using concentration and time parameters relevant to the clinical setting. This review discusses the rationale for using antioxidants in the prophylaxis or mitigation of human neurodiseases, with a critical discussion regarding ways in which future preclinical studies may be adjusted to offer more predictive value in selecting agents for translation into human trials. PMID:18997301

  1. The antioxidant protein Oxr1 influences aspects of mitochondrial morphology.

    PubMed

    Wu, Yixing; Davies, Kay E; Oliver, Peter L

    2016-06-01

    Oxidative stress (OS) and mitochondrial dysfunction are implicated in neurodegenerative disease, suggesting that antioxidant defence systems are critical for cell survival in the central nervous system (CNS). Oxidation resistance 1 (OXR1) can protect against OS in cellular and mouse models of amyotrophic lateral sclerosis (ALS) when over-expressed, whereas deletion of Oxr1 in mice causes neurodegeneration. OXR1 has emerged therefore as an essential antioxidant protein that controls the susceptibility of neurons to OS. It has been suggested that OXR1 is localised to mitochondria, yet the functional significance of this has not been investigated in the context of neuronal cell death. In order to characterise the role of Oxr1 in mitochondria, we investigated its sub-mitochondrial localisation and demonstrate that specific isoforms are associated with the outer mitochondrial membrane, while the full-length Oxr1 protein is predominately cytoplasmic. Interestingly, cytoplamsic over-expression of these mitochondrially-localised isoforms was still able to protect against OS-induced cell death and prevent rotenone-induced mitochondrial morphological changes. To study the consequences of Oxr1 deletion in vivo, we utilised the bella ataxic mouse mutant. We were unable to identify defects in mitochondrial metabolism in primary cerebellar granule cells (GCs) from bella mice, however a reduction in mitochondrial length was observed in mutant GCs compared to those from wild-type. Furthermore, screening a panel of proteins that regulate mitochondrial morphology in bella GCs revealed de-regulation of phospho-Drp1(Ser616), a key mitochondrial fission regulatory factor. Our data provide new insights into the function of Oxr1, revealing that specific isoforms of this novel antioxidant protein are associated with mitochondria and that the modulation of mitochondrial morphology may be an important feature of its protective function. These results have important implications for the

  2. A modified system to evaluate the potency of anti-oxidative compounds in different cell types in vitro.

    PubMed

    Mayer, D; Mühlhöfer, A; Biesalski, H K

    2001-05-29

    Common assays for evaluation of antioxidative capacity of different compounds are usually performed in cell-free systems. By this approach, cell-specific regulatory mechanisms upon distinct stimuli are not taken into account. Therefore, there is a need to measure anti-oxidative capacity in a cellular setting. - We now developed a valid method that provides monitoring of anti-oxidative capacities of compounds in different cell types. Oxidative stress, induced by 100 microM H subset2O subset2 in human microvascular endothelial cells (HMEC-1), was quantified by the generation of oxidized, fluorescent C-DCF from C-H subset2DCF-DA/AM. As DCF-production could be almost completely blocked by diethyldithiocarbamate (DEDTC), which inhibits intracellular Cu/Zn superoxide dismutase (SOD), mainly intracellular production of C-DCF was assumed. Preincubation with alpha-tocopherol resulted in a dose-dependent reduction of both spontaneous and H subset2O subset2-induced C-DCF-production (maximal inhibition by 41.6% at 75 microM). A synergistic effect was observed with co-incubation with vitamin C (maximal inhibition 46.8% at 10 microM vitamin C and 50 microM alpha-tocopherol). In this way compounds with different modes of action and subcellular localization can be evaluated concomitantly in respect of their anti-oxidative capacities. As this method was established on 24- and 48-well plates in other cell lines (Caco-2, HFP-1), too, screening of a large array of antioxidative compounds in different cell lines can be performed. PMID:11410401

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

    PubMed

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

    2016-02-01

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

  4. Preconditioning of heart by repeated stunning. Adaptive modification of antioxidative defense system.

    PubMed

    Das, D K; Prasad, M R; Lu, D; Jones, R M

    1992-11-01

    Previous studies demonstrated that preconditioning of a heart by repeated stunning can reduce the cellular injury to the heart from subsequent acute ischemic insult. To examine the possible biochemical mechanism for such myocardial preservation afforded by preconditioning, swine heart was subjected to four episodes of 5 min. stunning by occluding the left anterior descending coronary artery (LAD), followed by 10 min. of reperfusion after each stunning. Heart was then made regionally ischemic for 60 min. by LAD occlusion, followed by 6 hrs. reperfusion. Control heart was perfused for 60 min., followed by 60 min. ischemia and 6 hrs. reperfusion. The results of our studies indicated the stimulation of a number of antioxidative enzymes, including Mn-superoxide dismutase (Mn-SOD), catalase, glutathione peroxidase, and glutathione reductase, after repeated stunning and reperfusion. In addition, a number of new proteins were expressed after preconditioning the heart, including some oxidative-stress related proteins and 72 kDa heat-shock protein. These results suggest that preconditioning of a heart by repeated stunning may lead to strengthening of the oxidative defense system of the heart, which is likely to play a role in myocardial preservation during subsequent ischemic and reperfusion injury. PMID:1472901

  5. Lung and systemic oxidant and antioxidant activity after graded smoke exposure in the rat.

    PubMed

    Lalonde, C; Picard, L; Campbell, C; Demling, R

    1994-01-01

    We wanted to determine the effect of a graded smoke inhalation on lung and systemic oxidant stress, and its relationship to physiological and histological change. Male Wistar rats were given 12 breaths of 10 ml/kg (n = 8) (group 1) or 20 ml/kg (n = 8) (group 2) tidal volume, using cotton toweling smoke through the trachea using positive pressure. Rats were monitored, then killed at 24 hr. Data were compared to controls (n = 8). Peak group 1 and group 2 carboxyhemoglobins were 22 +/- 6 and 46 +/- 6%, with a mortality prior to 24 hr of 14% and 50%, respectively. Group 1 rats showed only moderate lung dysfunction but with severe airway inflammation and edema, alveolar inflammation and atelectasis, with a decrease in PaO2 from the control of 96 +/- 4 to 72 +/- 5 torr. No increase in lung, liver, or kidney oxidant-induced lipid peroxidation, measured as malondialdehyde lung, liver, or kidney oxidant-induced lipid peroxidation, measured as malondialdehyde (MDA), or decrease in the antioxidant defenses catalase was noted. Group 2 rats demonstrated severe airways edema, alveolar atelectasis, and alveolar edema, and a PaO2 decreasing below 60 torr, corresponding with a 3-fold increase in lung tissue MDA and 35% decrease in catalase. In addition, liver and kidney tissue MDA doubled, and catalase activity decreased by 40%. Increased oxygen consumption was also demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8149511

  6. The relationship of physicochemical properties to the antioxidative activity of free amino acids in Fenton system.

    PubMed

    Milić, Sonja; Bogdanović Pristov, Jelena; Mutavdžić, Dragosav; Savić, Aleksandar; Spasić, Mihajlo; Spasojević, Ivan

    2015-04-01

    Herein we compared antioxidative activities (AA) of 25 free L-amino acids (FAA) against Fenton system-mediated hydroxyl radical (HO(•)) production in aqueous solution, and examined the relation between AA and a set of physicochemical properties. The rank order according to AA was: Trp > norleucine > Phe, Leu > Ile > His >3,4-dihydroxyphenylalanine, Arg > Val > Lys, Tyr, Pro > hydroxyproline > α-aminobutyric acid > Gln, Thr, Ser > Glu, Ala, Gly, Asn, Asp. Sulfur-containing FAA generated different secondary reactive products, which were discriminated by the means of electron paramagnetic resonance spin-trapping spectroscopy. AA showed a general positive correlation with hydrophobicity. However, when taken separately, uncharged FAA exhibited strong positive correlation of AA with hydrophobicity whereas charged FAA showed negative or no significant correlation depending on the scale applied. A general strong negative correlation was found between AA and polarity. Steric parameters and hydration numbers correlated positively with AA of nonpolar side-chain FAA. In addition, a decrease of temperature which promotes hydrophobic hydration resulted in increased AA. This implies that HO(•)-provoked oxidation of FAA is strongly affected by hydrophobic hydration. Our findings are important for the understanding of oxidation processes in natural and waste waters. PMID:25764263

  7. Potassium contributes to zinc stress tolerance in peach (Prunus persica) seedlings by enhancing photosynthesis and the antioxidant defense system.

    PubMed

    Song, Z Z; Duan, C L; Guo, S L; Yang, Y; Feng, Y F; Ma, R J; Yu, M L

    2015-01-01

    Zinc (Zn) is considered to be a major industrial pollutant because excessive amounts can impair plant growth. In this paper, we found that peach 'Yoshihime' seedlings are promising Zn tolerant plants. However, heavy Zn toxicity (2 mM) damaged plant performance by disrupting biochemical processes, including photosynthesis, proline production, and K(+) nutrition. Notably, elevated external K(+) supply (10 mM) alleviated peach seedlings from Zn toxicity, evidenced by enhanced photosynthesis, antioxidant defense systems, and plant K(+) nutritional status. Moreover, the transcript levels of KUP (K(+) uptake) genes involved in K(+) acquisition, transport, and homeostasis were significantly upregulated following supply of sufficient K(+) upon Zn toxicity. In general, K(+) favorably contributes to improvements in internal K(+) homeostasis, via the help of K(+) transporters, further protecting plant photosynthesis and the antioxidative defense system. Our findings further benefit the study of the mechanisms underpinning heavy metal tolerance in woody plants. PMID:26345760

  8. Clostridium difficile colitis: pathogenesis and host defence.

    PubMed

    Abt, Michael C; McKenney, Peter T; Pamer, Eric G

    2016-10-01

    Clostridium difficile is a major cause of intestinal infection and diarrhoea in individuals following antibiotic treatment. Recent studies have begun to elucidate the mechanisms that induce spore formation and germination and have determined the roles of C. difficile toxins in disease pathogenesis. Exciting progress has also been made in defining the role of the microbiome, specific commensal bacterial species and host immunity in defence against infection with C. difficile. This Review will summarize the recent discoveries and developments in our understanding of C. difficile infection and pathogenesis. PMID:27573580

  9. Bacterial strategies to overcome insect defences.

    PubMed

    Vallet-Gely, Isabelle; Lemaitre, Bruno; Boccard, Frédéric

    2008-04-01

    Recent genetic and molecular analyses have revealed how several strategies enable bacteria to persist and overcome insect immune defences. Genetic and genomic tools that can be used with Drosophila melanogaster have enabled the characterization of the pathways that are used by insects to detect bacterial invaders and combat infection. Conservation of bacterial virulence factors and insect immune repertoires indicates that there are common strategies of host invasion and pathogen eradication. Long-term interactions of bacteria with insects might ensure efficient dissemination of pathogens to other hosts, including humans. PMID:18327270

  10. Herbivory: Caterpillar saliva beats plant defences

    NASA Astrophysics Data System (ADS)

    Musser, Richard O.; Hum-Musser, Sue M.; Eichenseer, Herb; Peiffer, Michelle; Ervin, Gary; Murphy, J. Brad; Felton, Gary W.

    2002-04-01

    Blood-feeding arthropods secrete special salivary proteins that suppress the defensive reaction they induce in their hosts. This is in contrast to herbivores, which are thought to be helpless victims of plant defences elicited by their oral secretions. On the basis of the finding that caterpillar regurgitant can reduce the amount of toxic nicotine released by the tobacco plant Nicotiana tabacum, we investigate here whether specific salivary components from the caterpillar Helicoverpa zea might be responsible for this suppression. We find that the enzyme glucose oxidase counteracts the production of nicotine induced by the caterpillar feeding on the plant.

  11. In Defence of Multimodal Re-Signification: A Response to Havard Skaar's "In Defence of Writing"

    ERIC Educational Resources Information Center

    Adami, Elisabetta

    2011-01-01

    Responding to "In defence of writing" by Havard Skaar, published in issue 43.1 of this journal (April 2009), the present article argues that (1) compared with text production "from scratch," producing texts through copy-and-paste requires a different type of--rather than less--semiotic work, and that (2) digitally produced writing may involve the…

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

    SciTech Connect

    Wang, Lu; Gallagher, Evan P.

    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

  13. Comparative genomics tools applied to bioterrorism defence.

    PubMed

    Slezak, Tom; Kuczmarski, Tom; Ott, Linda; Torres, Clinton; Medeiros, Dan; Smith, Jason; Truitt, Brian; Mulakken, Nisha; Lam, Marisa; Vitalis, Elizabeth; Zemla, Adam; Zhou, Carol Ecale; Gardner, Shea

    2003-06-01

    Rapid advances in the genomic sequencing of bacteria and viruses over the past few years have made it possible to consider sequencing the genomes of all pathogens that affect humans and the crops and livestock upon which our lives depend. Recent events make it imperative that full genome sequencing be accomplished as soon as possible for pathogens that could be used as weapons of mass destruction or disruption. This sequence information must be exploited to provide rapid and accurate diagnostics to identify pathogens and distinguish them from harmless near-neighbours and hoaxes. The Chem-Bio Non-Proliferation (CBNP) programme of the US Department of Energy (DOE) began a large-scale effort of pathogen detection in early 2000 when it was announced that the DOE would be providing bio-security at the 2002 Winter Olympic Games in Salt Lake City, Utah. Our team at the Lawrence Livermore National Lab (LLNL) was given the task of developing reliable and validated assays for a number of the most likely bioterrorist agents. The short timeline led us to devise a novel system that utilised whole-genome comparison methods to rapidly focus on parts of the pathogen genomes that had a high probability of being unique. Assays developed with this approach have been validated by the Centers for Disease Control (CDC). They were used at the 2002 Winter Olympics, have entered the public health system, and have been in continual use for non-publicised aspects of homeland defence since autumn 2001. Assays have been developed for all major threat list agents for which adequate genomic sequence is available, as well as for other pathogens requested by various government agencies. Collaborations with comparative genomics algorithm developers have enabled our LLNL team to make major advances in pathogen detection, since many of the existing tools simply did not scale well enough to be of practical use for this application. It is hoped that a discussion of a real-life practical application of

  14. Eriocalyxin B-induced apoptosis in pancreatic adenocarcinoma cells through thiol-containing antioxidant systems and downstream signalling pathways.

    PubMed

    Li, L; Yue, G G L; Pu, J X; Sun, H D; Fung, K P; Leung, P C; Han, Q B; Lau, C B S; Leung, P S

    2014-01-01

    Thiol-containing antioxidant systems play an important role in regulating cellular redox homeostasis. Several anti-cancer agents act by targeting these systems by inducing the production of reactive oxygen species (ROS). Our earlier studies have shown that Eriocalyxin B (EriB), a diterpenoid isolated from Isodon eriocalyx, possesses anti-pancreatic tumour activities in vitro and in vivo. The present study further demonstrated that only thiol-containing antioxidants, N-acetylcysteine (NAC) or dithiothreitol (DTT), inhibited EriB-induced cytotoxicity and apoptosis. EriB suppressed the glutathione and thioredoxin antioxidant systems, thus increasing the intracellular ROS levels and regulating the MAPK, NFκB pathways. Treatment with EriB depleted the intracellular thiol-containing proteins in CAPAN-2 cells. In vivo studies also showed that EriB treatment (2.5 mg/kg) reduced the pancreatic tumour weights significantly in nude mice with increased superoxide levels. Taken together, our results shed important new light on the molecular mechanisms of EriB acting as an apoptogenic agent and its therapeutic potential for pancreatic cancer. PMID:24894173

  15. An Apparent Trade-Off between Direct and Signal-Based Induced Indirect Defence against Herbivores in Willow Trees

    PubMed Central

    Yoneya, Kinuyo; Uefune, Masayoshi; Takabayashi, Junji

    2012-01-01

    Signal-based induced indirect defence refers to herbivore-induced production of plant volatiles that attract carnivorous natural enemies of herbivores. Relationships between direct and indirect defence strategies were studied using tritrophic systems consisting of six sympatric willow species, willow leaf beetles (Plagiodera versicolora), and their natural predators, ladybeetles (Aiolocaria hexaspilota). Relative preferences of ladybeetles for prey-infested willow plant volatiles, indicating levels of signal-based induced indirect defence, were positively correlated with the vulnerability of willow species to leaf beetles, assigned as relative levels of direct defence. This correlation suggested a possible trade-off among the species, in terms of resource limitation between direct defence and signal-based induced indirect defence. However, analyses of volatiles from infested and uninfested plants showed that the specificity of infested volatile blends (an important factor determining the costs of signal-based induced indirect defence) did not affect the attractiveness of infested plant volatiles. Thus, the suggested trade-off in resource limitation was unlikely. Rather, principal coordinates analysis showed that this ‘apparent trade-off’ between direct and signal-based induced indirect defence was partially explained by differential preferences of ladybeetles to infested plant volatiles of the six willow species. We also showed that relative preferences of ladybeetles for prey-infested willow plant volatiles were positively correlated with oviposition preferences of leaf beetles and with the distributions of leaf beetles in the field. These correlations suggest that ladybeetles use the specificity of infested willow plant volatiles to find suitable prey patches. PMID:23251559

  16. The synthetic cationic lipid diC14 activates a sector of the Arabidopsis defence network requiring endogenous signalling components.

    PubMed

    Cambiagno, Damián Alejandro; Lonez, Caroline; Ruysschaert, Jean-Marie; Alvarez, María Elena

    2015-12-01

    Natural and synthetic elicitors have contributed significantly to the study of plant immunity. Pathogen-derived proteins and carbohydrates that bind to immune receptors, allow the fine dissection of certain defence pathways. Lipids of a different nature that act as defence elicitors, have also been studied, but their specific effects have been less well characterized, and their receptors have not been identified. In animal cells, nanoliposomes of the synthetic cationic lipid 3-tetradecylamino-tert-butyl-N-tetradecylpropionamidine (diC14) activate the TLR4-dependent immune cascade. Here, we have investigated whether this lipid induces Arabidopsis defence responses. At the local level, diC14 activated early and late defence gene markers (FRK1, WRKY29, ICS1 and PR1), acting in a dose-dependent manner. This lipid induced the salicylic acid (SA)-dependent, but not jasmonic acid (JA)-dependent, pathway and protected plants against Pseudomonas syringae pv. tomato (Pst), but not Botrytis cinerea. diC14 was not toxic to plant or pathogen, and potentiated pathogen-induced callose deposition. At the systemic level, diC14 induced PR1 expression and conferred resistance against Pst. diC14-induced defence responses required the signalling protein EDS1, but not NDR1. Curiously, the lipid-induced defence gene expression was lower in the fls2/efr/cerk1 triple mutant, but still unchanged in the single mutants. The amidine headgroup and chain length were important for its activity. Given the robustness of the responses triggered by diC14, its specific action on a defence pathway and the requirement for well-known defence components, this synthetic lipid is emerging as a useful tool to investigate the initial events involved in plant innate immunity. PMID:25727690

  17. Alteration of hepatic anti-oxidant systems by 4-nonylphenol, a metabolite of alkylphenol polyethoxylate detergents, in Far Eastern catfish Silurus asotus

    PubMed Central

    Park, Kwan Ha

    2015-01-01

    Objectives This study aimed to estimate the effects of 4-nonylphenol (NP), a ubiquitously present surfactant in aquatic environments, on the anti-oxidant systems of the liver in the Far Eastern catfish Silurus asotus. Methods Changes in biochemical parameters involved in glutathione (GSH)-related and other anti-oxidant systems were analyzed following 4 weeks of 4-NP administration (0.1 and 1.0 mg/kg diet) via a formulated diet to catfish. Results 4-NP exposure induced an elevation in hepatic lipid peroxide levels and an accompanying decrease in reduced state GSH after 2 weeks, suggesting pro-oxidant effects of the chemical in catfish. This oxidative stress was associated with an inhibition of the GSH-utilizing enzyme glutathione peroxidase at the same time point. This inhibition was restored after 4 weeks. The activities of other anti-oxidant enzymes, i.e., glutathione reductase, superoxide dismutase and catalase were increased after 4 weeks. These enzyme increases occurred more strongly at the higher 4-NP concentration (1.0 mg/kg diet). Conclusions 4-NP given to catfish at 0.1 to 1.0 mg/kg diet, concentrations relevant to environmental levels, depletes the endogenous anti-oxidant molecule GSH and temporarily inhibits GSH-related anti-oxidant enzymes. Such declines in anti-oxidant capacity and elevated oxidative stress seem to be compensated eventually by subsequent activation of various anti-oxidant enzyme systems. PMID:26602557

  18. How insects overcome two-component plant chemical defence: plant β-glucosidases as the main target for herbivore adaptation.

    PubMed

    Pentzold, Stefan; Zagrobelny, Mika; Rook, Fred; Bak, Søren

    2014-08-01

    Insect herbivory is often restricted by glucosylated plant chemical defence compounds that are activated by plant β-glucosidases to release toxic aglucones upon plant tissue damage. Such two-component plant defences are widespread in the plant kingdom and examples of these classes of compounds are alkaloid, benzoxazinoid, cyanogenic and iridoid glucosides as well as glucosinolates and salicinoids. Conversely, many insects have evolved a diversity of counteradaptations to overcome this type of constitutive chemical defence. Here we discuss that such counter-adaptations occur at different time points, before and during feeding as well as during digestion, and at several levels such as the insects’ feeding behaviour, physiology and metabolism. Insect adaptations frequently circumvent or counteract the activity of the plant β-glucosidases, bioactivating enzymes that are a key element in the plant’s two-component chemical defence. These adaptations include host plant choice, non-disruptive feeding guilds and various physiological adaptations as well as metabolic enzymatic strategies of the insect’s digestive system. Furthermore, insect adaptations often act in combination, may exist in both generalists and specialists, and can act on different classes of defence compounds. We discuss how generalist and specialist insects appear to differ in their ability to use these different types of adaptations: in generalists, adaptations are often inducible, whereas in specialists they are often constitutive. Future studies are suggested to investigate in detail how insect adaptations act in combination to overcome plant chemical defences and to allow ecologically relevant conclusions. PMID:25165798

  19. Serum Antioxidative Enzymes Levels and Oxidative Stress Products in Age-Related Cataract Patients

    PubMed Central

    Chang, Dong; Zhang, Xuefei; Rong, Shengzhong; Sha, Qian; Liu, Peipei; Han, Tao; Pan, Hongzhi

    2013-01-01

    Purpose. To investigate the activity of antioxidative enzymes and the products of oxidative stress in patients with age-related cataracts and compare the findings with those in healthy control subjects. Method. Sixty patients with age-related cataract and sixty healthy controls of matched age and gender were included in this study. Serum samples were obtained to detect the antioxidative enzymes of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and oxidation degradation products of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), conjugated diene (CD), advanced oxidation protein products (AOPP), protein carbonyl (PC), and 8-hydroxydeoxyguanosine (8-OHdG). Results. Serum SOD, GSH-Px, and CAT activities in cataract group were significantly decreased as compared to the control subjects (P < 0.05). The levels of MDA, 4-HNE, and CD in cataract patients were significantly higher than those in the control subjects (P < 0.05, P < 0.01). Cataract patients had higher levels of 8-OHdG, AOPP, and PC with respect to the comparative group of normal subjects (P < 0.01). And there was no statistical significance in concentration of antioxidative enzymes and oxidative stress products in patients with different subtype cataract. Conclusions. Oxidative stress is an important risk factor in the development of age-related cataract, and augmentation of the antioxidant defence systems may be of benefit to prevent or delay cataractogenesis. PMID:23781296

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

    PubMed

    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. PMID:17650585

  1. Effects of ionizing radiation on the antioxidant system of microscopic fungi with radioadaptive properties found in the Chernobyl exclusion zone.

    PubMed

    Tugay, Tatyana I; Zheltonozhskaya, Marina V; Sadovnikov, Leonid V; Tugay, Andrei V; Farfán, Eduardo B

    2011-10-01

    Some microscopic fungi found in the area of the Chernobyl Exclusion Zone appear to have unique radioadaptive properties associated with their capability to respond positively to the effects of ionizing irradiation. On the one hand, this capability can be used potentially in bio-remediation technologies, and on the other hand, it requires additional, more thorough studies to identify its underlying mechanisms. Practically, no data are currently available on mechanisms for implementation of these radioadaptive properties by microscopic fungi. The objective of the completed study was to evaluate the functioning of the antioxidant system of a microscopic fungus as one of potential mechanisms for implementation of its radioadaptive properties. The study was performed using a model system simulating the soil radioactivity in the 5-km zone around the Chernobyl Nuclear Power Plant, with the ratio of the radioactive isotopes matching the radionuclide content in the fuel component of the Chernobyl fallout. The completed study was the first ever performed to identify a comprehensive response of the major components of the antioxidant system of the microscopic fungi to ionizing radiation, resulting in an induced melanin synthesis and increased activity of the known enzymes of antioxidant protection. Their response to ionizing radiation depended on the presence or absence of radioadaptive properties and phase of the fungal growth. Fungi with radioadaptive properties have a much higher susceptibility for inducing synthesis of melanin and antioxidant enzymes than fungi without radioadaptive properties (hereinafter referred to as the reference species or strains), which illustrates the contribution of these processes to "radiophilia" of the fungi. PMID:21878763

  2. An antioxidant redox system in the nucleus of wheat seed cells suffering oxidative stress.

    PubMed

    Pulido, Pablo; Cazalis, Roland; Cejudo, Francisco Javier

    2009-01-01

    Cereal seed cells contain different mechanisms for protection against the oxidative stress that occurs during maturation and germination. One such mechanism is based on the antioxidant activity of a 1-Cys peroxiredoxin (1-Cys Prx) localized in the nuclei of aleurone and scutellum cells. However, nothing is known about the mechanism of activation of this enzyme. Here, we describe the pattern of localization of NADPH thioredoxin reductase (NTR) in developing and germinating wheat seeds using an immunocytochemical analysis. The presence of NTR in transfer cells, vascular tissue, developing embryo and root meristematic cells, agrees with the localization of thioredoxin h (Trx h), and supports the important function of the NTR/Trx system in cell proliferation and communication. Interestingly, NTR is found in the nuclei of seed cells suffering oxidative stress, thus showing co-localization with Trx h and 1-Cys Prx. To test whether the NTR/Trx system serves as a reductant of the 1-Cys Prx, we cloned a full-length cDNA encoding 1-Cys Prx from wheat, and expressed the recombinant protein in Escherichia coli. Using the purified components, we show NTR-dependent activity of the 1-Cys Prx. Mutants of the 1-Cys Prx allowed us to demonstrate that the peroxidatic residue of the wheat enzyme is Cys46, which is overoxidized in vitro under oxidant conditions. Analysis of extracts from developing and germinating seeds confirmed 1-Cys Prx overoxidation in vivo. Based on these results, we propose that NADPH is the source of the reducing power to regenerate 1-Cys Prx in the nuclei of seed cells suffering oxidative stress, in a process that is catalyzed by NTR. PMID:18786001

  3. Antioxidant defenses in caterpillars: role of the ascorbate-recycling system in the midgut lumen.

    PubMed

    Barbehenn, R V; Bumgarner, S L; Roosen, E F; Martin, M M

    2001-04-01

    This study demonstrates that an ascorbate-recycling system in the midgut lumen can act as an effective antioxidant defense in caterpillars that feed on prooxidant-rich foods. In tannin-sensitive larvae of the forest tent caterpillar, Malacosoma disstria (Lasiocampidae), ingested tannic acid is oxidized in the midgut lumen, generating significant quantities of peroxides, including hydrogen peroxide, which readily diffuses across cell membranes and is a powerful cytotoxin. By contrast, in the tannin-tolerant larvae of the white-marked tussock moth, Orgyia leucostigma (Lymantriidae), tannic acid oxidation and the generation of peroxides are suppressed. The superior defense of O. leucostigma against oxidative stress imposed by the oxidation of ingested polyphenols can be explained by the presence of higher concentrations of ascorbate and glutathione in the midgut lumen. In O. leucostigma at least 50% of the ingested ascorbate present in the anterior midgut is still present in the posterior midgut, whereas in M. disstria, only 10% of the ascorbate is present in the posterior half of the midgut. We propose that the maintenance of higher levels of ascorbate in the midgut lumen of O. leucostigma than in M. disstria is explained by the secretion of glutathione into the midgut lumen by O. leucostigma, thereby forming a complete ascorbate-recycling system. The concentration of glutathione in the midgut lumen of O. leucostigma is 3.5-fold higher than in M. disstria and more than double the concentration in the diet. Our results emphasize the importance of a defensive strategy in herbivorous insects based on the maintenance of conditions in the gut lumen that reduce or eliminate the potential prooxidant behavior of ingested phenols. PMID:11166299

  4. Hydrogen sulfide induces systemic tolerance to salinity and non-ionic osmotic stress in strawberry plants through modification of reactive species biosynthesis and transcriptional regulation of multiple defence pathways.

    PubMed

    Christou, Anastasis; Manganaris, George A; Papadopoulos, Ioannis; Fotopoulos, Vasileios

    2013-04-01

    Hydrogen sulfide (H2S) has been recently found to act as a potent priming agent. This study explored the hypothesis that hydroponic pretreatment of strawberry (Fragaria × ananassa cv. Camarosa) roots with a H2S donor, sodium hydrosulfide (NaHS; 100 μM for 48 h), could induce long-lasting priming effects and tolerance to subsequent exposure to 100mM NaCI or 10% (w/v) PEG-6000 for 7 d. Hydrogen sulfide pretreatment of roots resulted in increased leaf chlorophyll fluorescence, stomatal conductance and leaf relative water content as well as lower lipid peroxidation levels in comparison with plants directly subjected to salt and non-ionic osmotic stress, thus suggesting a systemic mitigating effect of H2S pretreatment to cellular damage derived from abiotic stress factors. In addition, root pretreatment with NaHS resulted in the minimization of oxidative and nitrosative stress in strawberry plants, manifested via lower levels of synthesis of NO and H(2)O(2) in leaves and the maintenance of high ascorbate and glutathione redox states, following subsequent salt and non-ionic osmotic stresses. Quantitative real-time RT-PCR gene expression analysis of key antioxidant (cAPX, CAT, MnSOD, GR), ascorbate and glutathione biosynthesis (GCS, GDH, GS), transcription factor (DREB), and salt overly sensitive (SOS) pathway (SOS2-like, SOS3-like, SOS4) genes suggests that H2S plays a pivotal role in the coordinated regulation of multiple transcriptional pathways. The ameliorative effects of H2S were more pronounced in strawberry plants subjected to both stress conditions immediately after NaHS root pretreatment, rather than in plants subjected to stress conditions 3 d after root pretreatment. Overall, H2S-pretreated plants managed to overcome the deleterious effects of salt and non-ionic osmotic stress by controlling oxidative and nitrosative cellular damage through increased performance of antioxidant mechanisms and the coordinated regulation of the SOS pathway, thus proposing a

  5. Hydrogen sulfide induces systemic tolerance to salinity and non-ionic osmotic stress in strawberry plants through modification of reactive species biosynthesis and transcriptional regulation of multiple defence pathways

    PubMed Central

    Christou, Anastasis; Manganaris, George A.; Papadopoulos, Ioannis; Fotopoulos, Vasileios

    2013-01-01

    Hydrogen sulfide (H2S) has been recently found to act as a potent priming agent. This study explored the hypothesis that hydroponic pretreatment of strawberry (Fragaria × ananassa cv. Camarosa) roots with a H2S donor, sodium hydrosulfide (NaHS; 100 μM for 48h), could induce long-lasting priming effects and tolerance to subsequent exposure to 100mM NaCI or 10% (w/v) PEG-6000 for 7 d. Hydrogen sulfide pretreatment of roots resulted in increased leaf chlorophyll fluorescence, stomatal conductance and leaf relative water content as well as lower lipid peroxidation levels in comparison with plants directly subjected to salt and non-ionic osmotic stress, thus suggesting a systemic mitigating effect of H2S pretreatment to cellular damage derived from abiotic stress factors. In addition, root pretreatment with NaHS resulted in the minimization of oxidative and nitrosative stress in strawberry plants, manifested via lower levels of synthesis of NO and H2O2 in leaves and the maintenance of high ascorbate and glutathione redox states, following subsequent salt and non-ionic osmotic stresses. Quantitative real-time RT-PCR gene expression analysis of key antioxidant (cAPX, CAT, MnSOD, GR), ascorbate and glutathione biosynthesis (GCS, GDH, GS), transcription factor (DREB), and salt overly sensitive (SOS) pathway (SOS2-like, SOS3-like, SOS4) genes suggests that H2S plays a pivotal role in the coordinated regulation of multiple transcriptional pathways. The ameliorative effects of H2S were more pronounced in strawberry plants subjected to both stress conditions immediately after NaHS root pretreatment, rather than in plants subjected to stress conditions 3 d after root pretreatment. Overall, H2S-pretreated plants managed to overcome the deleterious effects of salt and non-ionic osmotic stress by controlling oxidative and nitrosative cellular damage through increased performance of antioxidant mechanisms and the coordinated regulation of the SOS pathway, thus proposing a novel

  6. Science and outreach for planetary defence

    NASA Astrophysics Data System (ADS)

    Stavinschi, M.

    2011-10-01

    The recent IAA Planetary Defence Conference held in Romania, focused on a hot topic: from Threat to Action. It is true that we ought to protect the planet but also educate the population in this direction. Increasing rumours about pseudo-scientific issues, such as the impact with asteroids, comets or debris of spatial missions, the effects of the growing solar activity, the displacement of the terrestrial rotation axis following major earthquakes, let alone spreading news about the end-of-the-world, show how crucial it is to prepare people to understand what is going on in the universe and, in particular, on our planet, and how to deal with inevitable events. Another central question is in order: who should be in charge of this education? Perhaps the journalists, but they lack the necessary preparation to present correct and updated information to the public. Or the scientists, but they are extremely busy and concentrated on their projects aimed at defending the planet and at answering the vast array of questions that their research stirs up. Our goal is to answer the following question: to what extent is it the scientist's responsibility and to what extent the journalist's to educate people for the planetary defence? In addition, we shall suggest how they can effectively co-ordinate efforts to solve the current problems of a society submerged in increasingly sophisticated but decreasingly informed technologies.

  7. Maillard reaction, mitochondria and oxidative stress: potential role of antioxidants.

    PubMed

    Edeas, M; Attaf, D; Mailfert, A-S; Nasu, M; Joubet, R

    2010-06-01

    Glycation and oxidative stress are two important processes known to play a key role in complications of many disease processes. Oxidative stress, either via increasing reactive oxygen species (ROS), or by depleting the antioxidants may modulate the genesis of early glycated proteins in vivo. Maillard Reactions, occur in vivo as well as in vitro and are associated with the chronic complications of diabetes, aging and age-related diseases. Hyperglycaemia causes the autoxidation of glucose, glycation of proteins, and the activation of polyol metabolism. These changes facilitate the generation of reactive oxygen species and decrease the activity of antioxidant enzymes such as Cu,Zn-superoxide dismutase, resulting in a remarkable increase of oxidative stress. A large body of evidence indicates that mitochondria alteration is involved and plays a central role in various oxidative stress-related diseases. The damaged mitochondria produce more ROS (increase oxidative stress) and less ATP (cellular energy) than normal mitochondria. As they are damaged, they cannot burn or use glucose or lipid and cannot provide cell with ATP. Further, glucose, amino acids and lipid will not be correctly used and will accumulate outside the mitochondria; they will undergo more glycation (as observed in diabetes, obesity, HIV infection and lipodystrophia). The objective of this paper is to discuss how to stop the vicious circle established between oxidative stress, Maillard Reaction and mitochondria. The potential application of some antioxidants to reduce glycation phenomenon and to increase the antioxidant defence system by targeting mitochondria will be discussed. Food and pharmaceutical companies share the same challenge, they must act now, urgently and energetically. PMID:20031340

  8. Toxic effects of boron on growth and antioxidant system parameters of maize (Zea mays L.) roots.

    PubMed

    Esim, Nevzat; Tiryaki, Deniz; Karadagoglu, Omer; Atici, Okkes

    2013-10-01

    The aim of this study was to investigate the possible oxidative stress and the antioxidant response, which were caused on maize by boron (B). For this, 11- and 15-day-old maize seedlings were subjected to 2 or 4 mM B in the form of boric acid (H₃BO₃) for 2 and/or 6 days. At the end of the treatment period, root length, hydrogen peroxide (H₂O₂) content, malondialdehyde (MDA) content and the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were measured. The results revealed that root length of plants, activity of antioxidative enzymes such as SOD, POX and CAT and also H₂O₂ contents and MDA levels were seriously affected by excess B. These results suggested that the oxidative stress occurred due to the toxic effect of B. PMID:22491723

  9. Effects of vitamin C and E supplementation on endogenous antioxidant systems and heat shock proteins in response to endurance training.

    PubMed

    Cumming, Kristoffer T; Raastad, Truls; Holden, Geir; Bastani, Nasser E; Schneeberger, Damaris; Paronetto, Maria Paola; Mercatelli, Neri; Ostgaard, Hege N; Ugelstad, Ingrid; Caporossi, Daniela; Blomhoff, Rune; Paulsen, Gøran

    2014-10-01

    Reactive oxygen and nitrogen species are important signal molecules for adaptations to training. Due to the antioxidant properties of vitamin C and E, supplementation has been shown to blunt adaptations to endurance training. In this study, we investigated the effects of vitamin C and E supplementation and endurance training on adaptations in endogenous antioxidants and heat shock proteins (HSP). Thirty seven males and females were randomly assigned to receive Vitamin C and E (C + E; C: 1000 mg, E: 235 mg daily) or placebo (PLA), and underwent endurance training for 11 weeks. After 5 weeks, a subgroup conducted a high intensity interval session to investigate acute stress responses. Muscle and blood samples were obtained to investigate changes in proteins and mRNA related to the antioxidant and HSP system. The acute response to the interval session revealed no effects of C + E supplementation on NFκB activation. However, higher stress responses to exercise in C + E group was indicated by larger translocation of HSPs and a more pronounced gene expression compared to PLA. Eleven weeks of endurance training decreased muscle GPx1, HSP27 and αB-crystallin, while mnSOD, HSP70 and GSH remained unchanged, with no influence of supplementation. Plasma GSH increased in both groups, while uric acid decreased in the C + E group only. Our results showed that C + E did not affect long-term training adaptations in the antioxidant- and HSP systems. However, the greater stress responses to exercise in the C + E group might indicate that long-term adaptations occurs through different mechanisms in the two groups. PMID:25293598

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

    PubMed Central

    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 (p<0.05, linearly), total triglycerides (TG, p<0.05) and low-density lipoprotein cholesterol (LDL-C, p<0.05), as well as atherogenic index (p<0.001), whereas no change was observed in high-density lipoprotein cholesterol (p>0.05). 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

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

    PubMed

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

    2015-07-01

    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 (p<0.05, linearly), total triglycerides (TG, p<0.05) and low-density lipoprotein cholesterol (LDL-C, p<0.05), as well as atherogenic index (p<0.001), whereas no change was observed in high-density lipoprotein cholesterol (p>0.05). 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

  12. Costs of Inducible Defence along a Resource Gradient

    PubMed Central

    Brönmark, Christer; Lakowitz, Thomas; Nilsson, P. Anders; Ahlgren, Johan; Lennartsdotter, Charlotte; Hollander, Johan

    2012-01-01

    In addition to having constitutive defence traits, many organisms also respond to predation by phenotypic plasticity. In order for plasticity to be adaptive, induced defences should incur a benefit to the organism in, for example, decreased risk of predation. However, the production of defence traits may include costs in fitness components such as growth, time to reproduction, or fecundity. To test the hypothesis that the expression of phenotypic plasticity incurs costs, we performed a common garden experiment with a freshwater snail, Radix balthica, a species known to change morphology in the presence of molluscivorous fish. We measured a number of predator-induced morphological and behavioural defence traits in snails that we reared in the presence or absence of chemical cues from fish. Further, we quantified the costs of plasticity in fitness characters related to fecundity and growth. Since plastic responses may be inhibited under limited resource conditions, we reared snails in different densities and thereby levels of competition. Snails exposed to predator cues grew rounder and thicker shells, traits confirmed to be adaptive in environments with fish. Defence traits were consistently expressed independent of density, suggesting strong selection from predatory molluscivorous fish. However, the expression of defence traits resulted in reduced growth rate and fecundity, particularly with limited resources. Our results suggest full defence in predator related traits regardless of resource availability, and costs of defence consequently paid in traits related to fitness. PMID:22291961

  13. Costs of inducible defence along a resource gradient.

    PubMed

    Brönmark, Christer; Lakowitz, Thomas; Nilsson, P Anders; Ahlgren, Johan; Lennartsdotter, Charlotte; Hollander, Johan

    2012-01-01

    In addition to having constitutive defence traits, many organisms also respond to predation by phenotypic plasticity. In order for plasticity to be adaptive, induced defences should incur a benefit to the organism in, for example, decreased risk of predation. However, the production of defence traits may include costs in fitness components such as growth, time to reproduction, or fecundity. To test the hypothesis that the expression of phenotypic plasticity incurs costs, we performed a common garden experiment with a freshwater snail, Radix balthica, a species known to change morphology in the presence of molluscivorous fish. We measured a number of predator-induced morphological and behavioural defence traits in snails that we reared in the presence or absence of chemical cues from fish. Further, we quantified the costs of plasticity in fitness characters related to fecundity and growth. Since plastic responses may be inhibited under limited resource conditions, we reared snails in different densities and thereby levels of competition. Snails exposed to predator cues grew rounder and thicker shells, traits confirmed to be adaptive in environments with fish. Defence traits were consistently expressed independent of density, suggesting strong selection from predatory molluscivorous fish. However, the expression of defence traits resulted in reduced growth rate and fecundity, particularly with limited resources. Our results suggest full defence in predator related traits regardless of resource availability, and costs of defence consequently paid in traits related to fitness. PMID:22291961

  14. Computed Tomography Technology: Development and Applications for Defence

    NASA Astrophysics Data System (ADS)

    Baheti, G. L.; Saxena, Nisheet; Tripathi, D. K.; Songara, K. C.; Meghwal, L. R.; Meena, V. L.

    2008-09-01

    Computed Tomography(CT) has revolutionized the field of Non-Destructive Testing and Evaluation (NDT&E). Tomography for industrial applications warrants design and development of customized solutions catering to specific visualization requirements. Present paper highlights Tomography Technology Solutions implemented at Defence Laboratory, Jodhpur (DLJ). Details on the technological developments carried out and their utilization for various Defence applications has been covered.

  15. [Effects of microcystins on growth and antioxidant system of rice roots].

    PubMed

    Wang, Wei-Min; Deng, Yu; Zou, Hua; Liang, Chan-Juan

    2014-04-01

    The effect of different concentrations (1, 100, 1000 and 3 000 microg x L(-1)) of microcystins (MCs) on growth, absorb activity, antioxidant system and its accumulation in roots of rice seedlings were studied. The results show that MCs accumulation was positively correlated with MCs concentration. After the treatment with 1 microg x L(-1) MCs, the root growth and activity increased. Meanwhile, catalase (CAT) activity was increased to maintain H2O2 at normal levels. After the treatment with 100 microg x L(-1) MCs, the root growth and activity were inhibited whereas CAT had no obvious change. High concentrations (1000 microg x L(-1) and 3000 microg x L(-1)) of MCs not only inhibited root growth and activity, but decreased CAT activity, leading to excessive H2O2 accumulation and membrane peroxidation. After a 7-day recovery, MCs accumulations in roots in all treatment groups were all lower than those measured during the stress period. For the 100 microg x L(-1) MCs treated group, the inhibition on root growth and root activity, and membrane peroxidation were alleviated, better than those measured during the stress period. However, for 1000 microg x L(-1) and 3000 microg x L(-1) MCs treated groups, inhibition on root growth, root activity, and CAT activity were heavier than those during the stress period, and oxidation stress intensified further, indicating that the damage caused by high concentrations (1 000 microg x L(-1) and 3000 microg x L(-1)) of MCs on rice roots was irreversible. PMID:24946604

  16. [Effects of low magnesium on photosynthesis characteristics and antioxidant system in cucumber seedlings under low temperature].

    PubMed

    Zhu, Shuai; Wu, Guo-xiu; Cai, Huan; Liu, Zhang-lei; Liu, Jing; Yang, Rui; Ai, Xi-zhen

    2015-05-01

    The effects of low magnesium (30% Mg) stress on photosynthesis characteristics and antioxidant system in 'Jinyou 3' cucumber ( Cucumis sativa) seedlings under low temperature (day/ night temperature was 12 °C/8 °C) were investigated, with Hoagland nutrient solution treatment as the control. The results showed that the 30% Mg treatment showed a significantly lower Mg content in leaves, compared with the control. However, no marked difference in roots between the 30% Mg treatment and the control was found. Low temperature significantly decreased the chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (g(s)), and carboxylation efficiency (CE), while increased the intercelluar CO2 concentration (Ci). The 30% Mg treatment showed significantly lower chlorophyll content, Pn, g(s) and CE, compared with the control. No marked change was found in Ci between the 30% Mg treatment and the control. Low magnesium stress resulted in a more serious damage in chloroplast membrane under low temperature, and showed lower chloroplasts, grains and lamellas, while more and larger starch grains in cucumber seedlings. Low magnesium stress also led to an increase in MDA content, while a decrease in activities of superoxide dismutase (SOD) , peroxidase (POD) , catalase ( CAT) , ascorbate peroxidase (APX) and glutathione reductase (GR). These data suggested that magnesium deficiency caused by its hindered transportation under low temperature was the main reason for the chlorosis of cucumber leaves. The decrease in Pn was mainly caused by the non-stomatal limitation. Low magnesium stress increased the influence of low temperature on Pn, and the resulting decline in Pn was caused by the stomatal limitation. PMID:26571651

  17. [Effects of chilling stress on antioxidant system and ultrastructure of walnut cultivars].

    PubMed

    Tian, Jing-hua; Wang, Hong-xia; Zhang, Zhi-hua; Gao, Yi

    2015-05-01

    In order to reveal cold hardiness mechanisms and ascertain suitable cold hardiness biochemical indicators of walnut (Juglans regia) , three walnut cultivars ' Hartley' , 'Jinlong 1' and 'Jinlong 2' with strong to weak tolerance of chilling stress, were used to investigate variations of leaf antioxidant enzyme activity and superoxide anion (O2-·) content in one year-old branches under chilling stress at 1 °C in leaf-expansion period. The mesophyll cells ultrastructure of ' Hartley' and 'Jinlong 2' under chilling stress were also observed by transmission electron microscope. The results showed that the superoxide dismutase (SOD) and peroxidase (POD) enzyme activities were the strongest and O2-· content was the lowest in chilling-tolerant cultivar ' Hartley' under chilling stress among the three cultivars. The ultrastructure of the mesophyll cells was stable, and chilling injury symptoms of the leaves were not observed. In chilling-sensitive cultivar 'Jinlong 2' , the SOD, POD and catalase enzyme ( CAT) activities decreased sharply, and the O2-· content was kept at a high level under chilling stress. The ultrastructure of the mesophyll cells was injured obviously at 1 °C∟ for 72 hours. Most of chloroplasts were swollen, and grana lamella became thinner and fewer. A number of chloroplasts envelope and plasma membrane were damaged and became indistinct. At the same time, the edges of some of 'Jinlong 2' young leaves became water-soaked. It was concluded that the ultrastructure stability of mesophyll cells under chilling stress was closely related to walnut cold hardiness. SOD, POD enzyme activities and O2-· content in walnut leaves could be used as biochemical indicators of walnut cold hardiness in leaf-expansion period. There might be a correlation between the damage of cell membrane system and reactive oxygen accumulation under chilling stress. PMID:26571647

  18. The immunology of host defence peptides: beyond antimicrobial activity.

    PubMed

    Hancock, Robert E W; Haney, Evan F; Gill, Erin E

    2016-05-01

    Host defence peptides (HDPs) are short, cationic amphipathic peptides with diverse sequences that are produced by various cells and tissues in all complex life forms. HDPs have important roles in the body's response to infection and inflammation. This Review focuses on human HDPs and explores the diverse immunomodulatory effects of HDPs from a systems biology perspective, which highlights the interconnected nature of the effect (or effects) of HDPs on the host. Studies have demonstrated that HDPs are expressed throughout the body and mediate a broad range of activities, which explains their association with various inflammatory diseases and autoimmune disorders. The diverse actions of HDPs, such as their roles in wound healing and in the maintenance of the microbiota, are also explored, in addition to potential therapeutic applications. PMID:27087664

  19. A saponin-detoxifying enzyme mediates suppression of plant defences

    NASA Astrophysics Data System (ADS)

    Bouarab, K.; Melton, R.; Peart, J.; Baulcombe, D.; Osbourn, A.

    2002-08-01

    Plant disease resistance can be conferred by constitutive features such as structural barriers or preformed antimicrobial secondary metabolites. Additional defence mechanisms are activated in response to pathogen attack and include localized cell death (the hypersensitive response). Pathogens use different strategies to counter constitutive and induced plant defences, including degradation of preformed antimicrobial compounds and the production of molecules that suppress induced plant defences. Here we present evidence for a two-component process in which a fungal pathogen subverts the preformed antimicrobial compounds of its host and uses them to interfere with induced defence responses. Antimicrobial saponins are first hydrolysed by a fungal saponin-detoxifying enzyme. The degradation product of this hydrolysis then suppresses induced defence responses by interfering with fundamental signal transduction processes leading to disease resistance.

  20. Natural antioxidants.

    PubMed

    Berson, Diane S

    2008-07-01

    The constant exposure of the skin to oxidative stress results in damage to cellular DNA and cell membrane lipids and proteins. To combat this problem, the skin contains a number of antioxidants that protect against oxidative injury. However, these cutaneous antioxidants can be depleted by sun exposure and environmental insults, resulting in an overload of oxidation products. Thus, topical antioxidants that replenish the antioxidant capacity of the skin have the potential to prevent oxidative damage. A number of natural antioxidant ingredients also have anti-inflammatory properties, and can be used in the treatment of oxidative damage such as photoaging and perhaps even skin cancer. This article summarizes the active components, pharmacologic properties, and clinical effectiveness of a number of natural antioxidant ingredients including soy, feverfew, mushroom extracts, teas, Coffea arabica (CoffeeBerry), Pinus pinaster (Pycnogenol), and Polypodium leucotomos. Recent clinical trials suggest that these compounds have promising efficacy in the topical treatment of oxidative stress-induced dermatoses. PMID:18681153

  1. Transcriptional Suppression of Renal Antioxidant Enzyme Systems in Guinea Pigs Exposed to Polymerized Cell-Free Hemoglobin

    PubMed Central

    Rentsendorj, Otgonchimeg; Zhang, Xiaoyuan; Williams, Matthew C.; Buehler, Paul W.; D'Agnillo, Felice

    2016-01-01

    Hemoglobin-based oxygen carriers (HBOCs) are being developed as oxygen and plasma volume-expanding therapeutics though their potential to promote oxidative tissue injury has raised safety concerns. Using a guinea pig exchange transfusion model, we examined the effects of polymerized bovine hemoglobin (HbG) on the transcriptional regulation, activity, and expression of the renal antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). HbG infusion downregulated the mRNA levels for genes encoding SOD isoforms 1-3, GPx1, GPx3, GPx4, and CAT. This transcriptional suppression correlated with decreased enzymatic activities for SOD, CAT, and GPx. Immunostaining revealed decreased protein expression of SOD1, CAT, and GPx1 primarily in renal cortical tubules. DNA methylation analyses identified CpG hypermethylation in the gene promoters for SOD1-3, GPx1, GPx3, and GPx4, suggesting an epigenetic-based mechanism underlying the observed gene repression. HbG also induced oxidative stress as evidenced by increased renal lipid peroxidation end-products and 4-HNE immunostaining, which could be the result of the depleted antioxidant defenses and/or serve as a trigger for increased DNA methylation. Together, these findings provide evidence that the renal exposure to HbG suppresses the function of major antioxidant defense systems which may have relevant implications for understanding the safety of hemoglobin-based products. PMID:27471729

  2. Protection by ozone preconditioning is mediated by the antioxidant system in cisplatin-induced nephrotoxicity in rats.

    PubMed Central

    Borrego, Aluet; Zamora, Zullyt B; González, Ricardo; Romay, Cheyla; Menéndez, Silvia; Hernández, Frank; Montero, Teresita; Rojas, Enys

    2004-01-01

    BACKGROUND: Acute renal failure is a dose-limiting factor of cisplatin chemotherapy. Here, we show the protective effect of ozone oxidative preconditioning against cisplatin-induced renal dysfunction in rats. Ozone oxidative preconditioning is a prophylactic approach, which favors the antioxidant-pro-oxidant balance for preservation of the cell redox state by increasing antioxidant endogenous systems in various in vivo and in vitro experimental models. AIMS: To analyze the protective role of ozone oxidative preconditioning against cisplatin-induced nephrotoxicity. METHODS: Male Sprague-Dawley rats were pretreated with 15 intrarectal applications of ozone/oxygen mixture at 0.36, 0.72, 1.1, 1.8 and 2.5 mg/kg before cisplatin intraperitoneal injection (6 mg/kg). Serum and kidneys were extracted and analyzed 5 days after cisplatin treatment for determinations of the renal content of glutathione, thiobarbituric acid-reactive substances, renal concentration and enzymatic activities of catalase, superoxide dismutase and glutathione peroxidase. RESULTS: Ozone pretreatment prevented the increase in serum creatinine levels, the glutathione depletion and the inhibition of superoxide dismutase, catalase and glutathione peroxidase activities induced by cisplatin in the rat kidney. Also, the renal content of thiobarbituric acid-reactive substances was decreased by ozone therapy. These protective effects of ozone were dose dependent. CONCLUSIONS: Intrarectal ozone therapy prevented effectively the renal antioxidant unbalance induced by cisplatin treatment. PMID:15203559

  3. [Studies of the blood antioxidant system and oxygen-transporting properties of human erythrocytes during 105-day isolation].

    PubMed

    Brazhe, N A; Baĭzhumanov, A A; Parshina, E Iu; Iusipovich, A I; Akhalaia, M Ia; Iarlykova, Iu V; Labetskaia, O I; Ivanova, S M; Morukov, B V; Maksimov, G V

    2011-01-01

    Effects of strict 105-d isolation on blood antioxidant status, erythrocyte membrane processes and oxygen-binding properties of hemoglobin were studied in 6 male volunteers (25 to 40 y.o.) in ground-based simulation of a mission to Mars (experiment Mars-105). The parameters were measured using venous blood samples collected during BDC, on days 35, 70 and 105 of the experiment and on days 7 and 14-15 after its completion. Methods of biochemistry (determination of enzyme activity and thin-layer chromatography) and biophysical (laser interference microscopy, Raman spectroscopy) showed changes in relative content of lipid and phospholipid fractions suggesting growth of membrane microviscosity and increase in TBA-AP (active products of lipids peroxidation interacting with thiobarbituric acid). A significant increase in glucose-6-phosphate dehydrogenase and superoxide dismutase activities against reduction of catalase activity points to both reparative processes in erythrocytes and disbalance between the number of evolving active forms of oxygen and antioxidant protection mechanisms in cells. Hemoglobin sensitivity of oxygen and blood level of oxyhemoglobin were found to increase, too. It is presumed that adaptation of organism to stresses experienced during and after the experiment may destroy balance of the antioxidant protection systems which is conducive to oxidation of membrane phospholipids, alteration of their content, increase of membrane microviscosity and eventual failure of the gas-exchange function of erythrocytes. PMID:21675192

  4. Ionic liquid-based aqueous biphasic systems as a versatile tool for the recovery of antioxidant compounds.

    PubMed

    Santos, João H; e Silva, Francisca A; Ventura, Sónia P M; Coutinho, João A P; de Souza, Ranyere L; Soares, Cleide M F; Lima, Álvaro S

    2015-01-01

    The comparative evaluation of distinct types of ionic liquid-based aqueous biphasic systems (IL-ABS) and more conventional polymer/salt-based ABS to the extraction of two antioxidants, eugenol and propyl gallate, is focused. In a first approach, IL-ABS composed of ILs and potassium citrate (C6H5K3O7/C6H8O7) buffer at pH 7 were applied to the extraction of two antioxidants, enabling the assessment of the impact of IL cation core on the extraction. The second approach uses ABS composed of polyethylene glycol (PEG) and potassium phosphate (K2HPO4/KH2PO4) buffer at pH 7 with imidazolium-based ILs as adjuvants. Their application to the extraction of the compounds allowed the investigation of the impact of the presence/absence of IL, the PEG molecular weight, and the alkyl side chain length of the imidazolium cation on the partition. It is possible to maximize the extractive performance of both antioxidants up to 100% using both types of IL-ABS. The IL enhances the performance of ABS technology. The data puts in evidence the pivotal role of the appropriate selection of the ABS components and design to develop a successful extractive process, from both environmental and performance points of view. PMID:25311237

  5. Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity

    PubMed Central

    Shanely, R. Andrew; Nieman, David C.; Perkins-Veazie, Penelope; Henson, Dru A.; Meaney, Mary P.; Knab, Amy M.; Cialdell-Kam, Lynn

    2016-01-01

    Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and act as a countermeasure to exercise-induced inflammation and innate immune changes. Trained cyclists (n = 20, 48 ± 2 years) participated in a randomized, placebo controlled, crossover study. Subjects completed two 75 km cycling time trials after either 2 weeks ingestion of 980 mL/day WM puree or no treatment. Subjects drank either WM puree containing 0.2 gm/kg carbohydrate or a 6% carbohydrate beverage every 15 min during the time trials. Blood samples were taken pre-study and pre-, post-, 1 h post-exercise. WM ingestion versus no treatment for 2-weeks increased plasma l-citrulline and l-arginine concentrations (p < 0.0125). Exercise performance did not differ between WM puree or carbohydrate beverage trials (p > 0.05), however, the rating of perceived exertion was greater during the WM trial (p > 0.05). WM puree versus carbohydrate beverage resulted in a similar pattern of increase in blood glucose, and greater increases in post-exercise plasma antioxidant capacity, l-citrulline, l-arginine, and total nitrate (all p < 0.05), but without differences in systemic markers of inflammation or innate immune function. Daily WM puree consumption fully supported the energy demands of exercise, and increased post-exercise blood levels of WM nutritional components (l-citrulline and l-arginine), antioxidant capacity, and total nitrate, but without an influence on post-exercise inflammation and changes in innate immune function. PMID:27556488

  6. Comparison of taurine and pantoyltaurine as antioxidants in vitro and in the central nervous system of diabetic rats.

    PubMed

    Patel, Sanket N; Pandya, Kashyap; Clark, George J; Parikh, Mitul C; Lau-Cam, Cesar A

    2016-01-01

    This study has comparatively evaluated the antiradical and antilipid peroxidizing actions of taurine (TAU) and its N-pantoyl analog pantoyltaurine (PTAU) in vitro, and has determined the extent to which these findings agree with the in vivo ability of these compounds to prevent changes in plasma glucose and in indices of oxidative stress in the plasma, brain and spinal cord induced by the diabetogen streptozotocin (STZ) in Sprague-Dawley rats. Using free radical-generating and oxidizing systems, PTAU was found more effective than TAU in scavenging DPPH, hydroxyl, peroxyl, and superoxide anion radicals and peroxynitrite, and in preventing lipid peroxidation of a brain homogenate by iron (III)-dopamine and the oxidation of dopamine by iron (III). On the other hand, when administered intraperitoneally (i.p.) at a 1.2mM/kg dose, 75min and 45min before a single i.p., 60mg/kg, dose of (STZ), TAU was about equipotent with PTAU in attenuating STZ-induced increases in glucose, malondialdehyde (MDA) and nitric oxide (NO), and the loss of reduced glutathione (GSH) in plasma collected at 24h post STZ. Moreover, the analysis of concurrently collected brain and spinal cords samples revealed that both TAU and PTAU were able to equally reverse the increases in MDA and NO concentrations and to effectively counteract the decrease in the GSH/GSSG ratio caused by STZ. Likewise, both compounds were very effective in preventing the losses of tissue catalase, glutathione peroxidase and superoxide dismutase activities. A comparison of the results for spinal cord and for brain parts such as the cerebellum, cortex and brain stem suggested the existence of regional differences in antioxidant potency between TAU and PTAU, especially in terms of antioxidant enzymes. In general, differences in antiradical and antioxidant potencies between TAU and PTAU derived from in vitro test are not reliable indicators of the antioxidant potencies these compounds may subsequently manifest in a living

  7. Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity.

    PubMed

    Shanely, R Andrew; Nieman, David C; Perkins-Veazie, Penelope; Henson, Dru A; Meaney, Mary P; Knab, Amy M; Cialdell-Kam, Lynn

    2016-01-01

    Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and act as a countermeasure to exercise-induced inflammation and innate immune changes. Trained cyclists (n = 20, 48 ± 2 years) participated in a randomized, placebo controlled, crossover study. Subjects completed two 75 km cycling time trials after either 2 weeks ingestion of 980 mL/day WM puree or no treatment. Subjects drank either WM puree containing 0.2 gm/kg carbohydrate or a 6% carbohydrate beverage every 15 min during the time trials. Blood samples were taken pre-study and pre-, post-, 1 h post-exercise. WM ingestion versus no treatment for 2-weeks increased plasma l-citrulline and l-arginine concentrations (p < 0.0125). Exercise performance did not differ between WM puree or carbohydrate beverage trials (p > 0.05), however, the rating of perceived exertion was greater during the WM trial (p > 0.05). WM puree versus carbohydrate beverage resulted in a similar pattern of increase in blood glucose, and greater increases in post-exercise plasma antioxidant capacity, l-citrulline, l-arginine, and total nitrate (all p < 0.05), but without differences in systemic markers of inflammation or innate immune function. Daily WM puree consumption fully supported the energy demands of exercise, and increased post-exercise blood levels of WM nutritional components (l-citrulline and l-arginine), antioxidant capacity, and total nitrate, but without an influence on post-exercise inflammation and changes in innate immune function. PMID:27556488

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

    SciTech Connect

    Kasperczyk, Sławomir; Dobrakowski, Michał; Kasperczyk, Janusz; Ostałowska, Alina; Zalejska-Fiolka, Jolanta; Birkner, Ewa

    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.

  9. Sex differences in the blood antioxidant defense system in juvenile rats with various genetic predispositions to hypertension.

    PubMed

    Horvathova, Martina; Zitnanova, Ingrid; Kralovicova, Zuzana; Balis, Peter; Puzserova, Angelika; Muchova, Jana; Kluknavsky, Michal; Durackova, Zdenka; Bernatova, Iveta

    2016-02-01

    This study investigated the contribution of blood oxidative stress (OS) to the development of hypertension, as well as sex differences in the antioxidant defense system (ADS) in genetic models of hypertension. Nine-week-old normotensive Wistar-Kyoto (WKY) rats, borderline hypertensive rats (BHR) and spontaneously hypertensive rats (SHR) of both sexes were used. Systolic blood pressure (SBP) was determined by tail-cuff plethysmography, the trolox equivalent antioxidant capacity (TEAC) and the concentration of lipid peroxides (LP) were determined in plasma. The activity of the antioxidant enzymes Cu/Zn-superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) was determined in erythrocytes. SBP was significantly elevated in BHR and SHR in both sexes. BHR and SHR males had a higher SBP than the respective females. Sex-dependent differences in the ADS were found only in SHR, in which TEAC, SOD and CAT were significantly higher in males than in females. No differences in TEAC, SOD, CAT and GPx were observed between BHR (males and females) and WKY controls. LP levels were similar in all the groups investigated. Significant positive correlations were observed between SBP and both SOD and CAT. TEAC correlated positively with SOD and LP. As no signs of oxidative damage to lipids were found in young BHR and SHR of either sex, OS in the blood does not seem to be causatively related to the development of hypertension in these rats. However, despite activated antioxidant defenses, the positive correlation between plasma TEAC and LP suggests that oxidative damage is progressing slowly and therefore it seems to be a consequence rather than the cause of hypertension. PMID:26510784

  10. Exogenous low-dose hydrogen peroxide enhances drought tolerance of soybean (Glycine max L.) through inducing antioxidant system.

    PubMed

    Guler, Neslihan Saruhan; Pehlivan, Necla

    2016-06-01

    Hydrogen peroxide (H(2)O(2)) functions as a signal molecule in plants under abiotic and biotic stress. In this study, the role of exogenous H(2)O(2) in improving drought tolerance in two soybean cultivars (Glycine max L. Merrill) differing in their tolerance to drought was evaluated. Plants were grown in plastic pots with normal irrigation in a phytotron. Four weeks after radicle emergence, either 1 mM H(2)O(2) or distilled water was sprayed as foliar onto the leaves of each plant, after drought stress was applied. Leaf samples were harvested on the 4(th) and 7(th) days of the drought. Antioxidant-related enzyme activity, such as the superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) content was measured during the drought period. Drought stress decreased leaf water potential, relative water content and photosynthetic pigment content but enhanced lipid peroxidation and endogenous H(2)O(2) concentration. By contrast, exogenous low dose H(2)O(2) improved water status, pigment content and lipid peroxidation under drought stress. Endogenous H(2)O(2) concentration was reduced by exogenous H(2)O(2) as compared to drought treatment alone. H(2)O(2) pre-treatment induced all the antioxidant enzyme activities, to a greater extent than the control leaves, during drought. H(2)O(2) pretreatment further enhanced the activities of antioxidant enzymes in the tolerant cultivar compared to the sensitive cultivar. Results suggested that low dose H(2)O(2) pre-treatment alleviated water loss and H(2)O(2) content and increased drought stress tolerance by inducing the antioxidant system. PMID:27165528

  11. Antioxidants delay clinical signs and systemic effects of ENU induced brain tumors in rats.

    PubMed

    Hervouet, E; Staehlin, O; Pouliquen, D; Debien, E; Cartron, P-F; Menanteau, J; Vallette, F M; Olivier, C

    2013-01-01

    According to our previous study suggesting that antioxidant properties of phytochemicals in the diet decrease glioma aggressiveness, we used a SUVIMAX-like diet ("Supplementation en VItamines et Minéraux AntioXydants") (enriched with alpha-tocopherol, beta carotene, vitamin C, zinc, and sodium selenite), adapted to rats. The present results showed that each of the antioxidants inhibited growth of glioma cells in vitro. When used in combination for in vivo studies, we showed a highly significant delay in the clinical signs of the disease, but not a statistical significant difference in the incidence of glioma in an Ethyl-nitrosourea (ENU)-model. The SUVIMAX-like diet decreased candidate markers of tumoral aggressiveness and gliomagenesis progression. The mRNA expressions of 2 common markers in human glioma: Mn-SOD (Manganese Superoxide Dismutase) and IGFBP5 (insulin growth factor binding protein) were reduced in the tumors of rats fed the antioxidant diet. In addition, the transcripts of two markers linked to brain tumor proliferation, PDGFRb (platelet-derived growth factor receptor beta) and Ki-67, were also significantly decreased. On the whole, our results suggest a protective role for antioxidants to limit aggressiveness and to some extent, progression of gliomas, in a rat model. PMID:23859036

  12. Effect of Compost Socks System on Antioxidant Capacity, Flavonoid Content, and Fruit Quality of Strawberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of cultivation practices on fruit quality, antioxidant capacity, and flavonoid content in strawberries cv. Allstar and Chandler was evaluated. Strawberry fruit used in this study were from plants grown in soils which had prior history of black root rot and red stele and had not been fumig...

  13. Effect of Compost Socks System on Antioxidant Capacity, Flavonoid Content, and Fruit Quality of Strawberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of cultivation practices on fruit quality, antioxidant capacity, and flavonoid content in strawberries var. Allstar and Chandler (Fragaria x ananassa Duch.) was evaluated. Strawberry fruit used in this study were from plants grown in soils which had prior history of black root rot and red...

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

    PubMed

    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. PMID:23376123

  15. Optimized DPPH assay in a detergent-based buffer system for measuring antioxidant activity of proteins

    PubMed Central

    Nicklisch, Sascha C.T.; Waite, J. Herbert

    2014-01-01

    The free radical method using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) is a well established assay for the in vitro determination of antioxidant activity in food and biological extracts. The standard DPPH assay uses methanol or ethanol as solvents, or buffered alcoholic solutions in a ratio of 40%/60% (buffer/alcohol, v/v) to keep the hydrophobic hydrazyl radical and phenolic test compounds soluble while offering sufficient buffering capacity at different pHs tested. Following this protocol, we were unable to keep proteinaceous antioxidants soluble at different pHs to test for their antioxidant activity. Thus, the assay protocol was modified as follows to improve its utility:•Non-ionic detergents were added to keep the DPPH radical soluble and to provide a mild and non-denaturing environment for the antioxidant protein.•Maximal concentration of DPPH was limited to 100 μM to stay within the sensitivity range of the detector at the given wavelength (515 nm) and to increase the dynamic range of the assay.•0.1 M citrate phosphate buffer was introduced to prevent experimental artifacts due to changing buffer compositions at different pHs. PMID:25530949

  16. Oxidative stress and anti-oxidant defense system in Iranian women with polycystic ovary syndrome

    PubMed Central

    Moti, Mahtab; Amini, Leila; Mirhoseini Ardakani, Soheila Sadat; Kamalzadeh, Sara; Masoomikarimi, Masoomeh; jafarisani, Moslem

    2015-01-01

    Background: Polycystic ovary syndrome (PCOS) is a common disorder of infertility which affects more than 100 million women. It is characterized by chronic anovulation, hyper androgenism and obesity. PCOS is also associated with oxidative stress changes. Objective: Here, we aimed to investigate the level of antioxidants and oxidative stress in Iranian women with PCOS as a predictive factor for cardiovascular disease for the first time in Iran. Materials and Methods: In this cross sectional study 30 women with PCOS and 30 healthy women were included. C-reactive protein, serum insulin, advanced oxidation protein products, and level of total antioxidants status were measured from blood samples. Results: The levels of serum insulin, C-reactive protein, advanced oxidation protein productswere significantly increased in women with PCOS compared with healthy women but there was a decrease in level of total antioxidants status in PCOS women. Conclusion: These changes show that oxidative stress contributes to PCOS and the decrease of antioxidants leads to increase of oxidation products contributing to PCOS. PMID:26330853

  17. Role of the Immune System in Hypertension: Modulation by Dietary Antioxidants

    PubMed Central

    Vasdev, Sudesh; Stuckless, Jennifer; Richardson, Vernon

    2011-01-01

    Hypertension is a major health problem worldwide. Individuals with hypertension are at an increased risk for stroke, heart disease, and kidney failure. Although the etiology of essential hypertension has a genetic component, lifestyle factors such as diet play an important role. Insulin resistance is a common feature of hypertension in both humans and animal models affecting glucose and lipid metabolism producing excess aldehydes including methylglyoxal. These aldehydes react with proteins to form conjugates called advanced glycation end products (AGEs). This alters protein structure and function and can affect vascular and immune cells leading to their activation and secretion of inflammatory cytokines. AGEs also act via receptors for advanced glycation end products on these cells altering the function of antioxidant and metabolic enzymes, and ion channels. This results in an increase in cytosolic free calcium, decrease in nitric oxide, endothelial dysfunction, oxidative stress, peripheral vascular resistance, and infiltration of vascular and kidney tissue with inflammatory cells leading to hypertension. Supplementation with dietary antioxidants including vitamins C, E, or B6, thiols such as cysteine and lipoic acid, have been shown to lower blood pressure and plasma inflammatory cytokines in animal models and humans with essential hypertension. A well-balanced diet rich in antioxidants that includes vegetables, fruits, low fat dairy products, low salt, and includes whole grains, poultry, fish and nuts, lowers blood pressure and vascular inflammation. These antioxidants may achieve their antihypertensive and anti-inflammatory/immunomodulatory effects by reducing AGEs and improving insulin resistance and associated alterations. Dietary supplementation with antioxidants may be a beneficial, inexpensive, front-line alterative treatment modality for hypertension. PMID:23204821

  18. Dietary antioxidants and environmental stress.

    PubMed

    Kelly, Frank J

    2004-11-01

    Air is one of our most important natural resources; however, it is also in the front line for receiving environmental pollution. Air quality decreased markedly following the industrial revolution, but it was not until the great London Smog in 1952 that air quality made it onto the political agenda. The introduction of the Clean Air Act in 1956 led to dramatic decreases in black smoke and SO2 concentrations over the next two decades, as domestic and industrial coal-burning activities ceased. However, as these improvements progressed, a new threat to public health was being released into the air in ever-increasing quantities. Rapid motorisation of society from the 1960s onwards has led to the increased release of atmospheric pollutants such as tiny particles (particulate matter of <10 microm in aerodynamic diameter) and oxides of N, and the generation of the secondary pollutant O3. These primary and secondary traffic-related pollutants have all proved to be major risks factors to public health. Recently, oxidative stress has been identified as a unifying feature underlying the toxic actions of these pollutants. Fortunately, the surface of the lung is covered with a thin layer of fluid containing a range of antioxidants that appear to provide the first line of defence against oxidant pollutants. As diet is the only source of antioxidant micronutrients, a plausible link now exists between the sensitivity to air pollution and the quality of the food eaten. However, many questions remain unanswered in relation to inter-individual sensitivity to ambient air pollution, and extent to which this sensitivity is modified by airway antioxidant defences. PMID:15831130

  19. Antioxidants and the Integrity of Ocular Tissues

    PubMed Central

    Cabrera, Marcela P.; Chihuailaf, Ricardo H.

    2011-01-01

    Oxygen-derived free radicals are normally generated in many pathways. These radicals can interact with various cellular components and induce cell injury. When free radicals exceed the antioxidant capacity, cell injury causes diverse pathologic changes in the organs. The imbalance between the generation of free radicals and antioxidant defence is known as oxidative stress. The eye can suffer the effect of oxidative damage due to the etiopathogenesis of some pathological changes related to oxidative stress. This paper reviews the role of oxidative stress in the onset and progression of damage in different eye structures, the involvement of the antioxidant network in protecting and maintaining the homeostasis of this organ, and the potential assessment methodologies used in research and in some cases in clinical practice. PMID:21789267

  20. Antioxidative stress responses in the floating macrophyte Lemna minor L. with cylindrospermopsin exposure.

    PubMed

    Flores-Rojas, Nelida Cecilia; Esterhuizen-Londt, Maranda; Pflugmacher, Stephan

    2015-12-01

    Cylindrospermopsin toxicity and oxidative stress have been examined in aquatic animals, however, only a few studies with aquatic plants have been conducted focusing on the potential for bioaccumulation of cylindrospermopsin. The oxidative stress effects caused by cylindrospermopsin on macrophytes have not yet been specifically studied. The oxidative stress response of Lemna minor L. with exposure to cylindrospermopsin, was therefore tested in this study. The hydrogen peroxide concentration together with the activities of the antioxidant enzymes (catalase, peroxidase, glutathione reductase and glutathione S-transferase) were determined after 24h (hours) of exposure to varying concentrations (0.025, 0.25, 2.5 and 25μg/L) of cylindrospermopsin. Responses with longer exposure periods (48, 96, 168h) were tested only with exposure to 2.5 and 25μg/L cylindrospermopsin. Additionally, the content of the carotenoids was determined as a possible non-enzymatic antioxidant defence mechanism against cylindrospermopsin. The levels of hydrogen peroxide increased after 24h even at the lowest cylindrospermopsin exposure concentrations. Catalase showed the most representative antioxidant response observed after 24h and maintained its activity throughout the experiment. Catalase activity corresponded with the contents of hydrogen peroxide at 2.5 and 25μg/L cylindrospermopsin. The data suggest that glutathione S-transferase, glutathione reductase and the carotenoid content act together with catalase but are more sensitive to higher concentrations of cylindrospermopsin and after a longer exposure period (168h). The results indicate that cylindrospermopsin promotes oxidative stress in L. minor at concentrations of 2.5 and 25μg/L. However, L. minor has sufficient defence mechanisms in place against this cyanobacterial toxin. Even though L. minor exhibits the potential to managing and control cylindrospermopsin contamination in aquatic systems, further studies in tolerance limits to

  1. Antioxidants in Translational Medicine

    PubMed Central

    Schmidt, Harald H.H.W.; Stocker, Roland; Vollbracht, Claudia; Paulsen, Gøran; Riley, Dennis

    2015-01-01

    Abstract Significance: It is generally accepted that reactive oxygen species (ROS) scavenging molecules or antioxidants exert health-promoting effects and thus their consumption as food additives and nutraceuticals has been greatly encouraged. Antioxidants may be beneficial in situations of subclinical deficiency and increased demand or acutely upon high-dose infusion. However, to date, there is little clinical evidence for the long-term benefit of most antioxidants. Alarmingly, recent evidence points even to health risks, in particular for supplements of lipophilic antioxidants. Recent Advances: The biological impact of ROS depends not only on their quantities but also on their chemical nature, (sub)cellular and tissue location, and the rates of their formation and degradation. Moreover, ROS serve important physiological functions; thus, inappropriate removal of ROS may cause paradoxical reductive stress and thereby induce or promote disease. Critical Issues: Any recommendation on antioxidants must be based on solid clinical evidence and patient-relevant outcomes rather than surrogate parameters. Future Directions: Such evidence-based use may include site-directed application, time-limited high dosing, (functional) pharmacological repair of oxidized biomolecules, and triggers of endogenous antioxidant response systems. Ideally, these approaches need guidance by patient stratification through predictive biomarkers and possibly imaging modalities. Antioxid. Redox Signal. 23, 1130–1143. PMID:26154592

  2. The role of oxidative, inflammatory and neuroendocrinological systems during exercise stress in athletes: implications of antioxidant supplementation on physiological adaptation during intensified physical training.

    PubMed

    Slattery, Katie; Bentley, David; Coutts, Aaron J

    2015-04-01

    During periods of intensified physical training, reactive oxygen species (ROS) release may exceed the protective capacity of the antioxidant system and lead to dysregulation within the inflammatory and neuroendocrinological systems. Consequently, the efficacy of exogenous antioxidant supplementation to maintain the oxidative balance in states of exercise stress has been widely investigated. The aim of this review was to (1) collate the findings of prior research on the effect of intensive physical training on oxidant-antioxidant balance; (2) summarise the influence of antioxidant supplementation on the reduction-oxidation signalling pathways involved in physiological adaptation; and (3) provide a synopsis on the interactions between the oxidative, inflammatory and neuroendocrinological response to exercise stimuli. Based on prior research, it is evident that ROS are an underlying aetiology in the adaptive process; however, the impact of antioxidant supplementation on physiological adaptation remains unclear. Equivocal results have been reported on the impact of antioxidant supplementation on exercise-induced gene expression. Further research is required to establish whether the interference of antioxidant supplementation consistently observed in animal-based and in vivo research extends to a practical sports setting. Moreover, the varied results reported within the literature may be due to the hormetic response of oxidative, inflammatory and neuroendocrinological systems to an exercise stimulus. The collective findings suggest that intensified physical training places substantial stress on the body, which can manifest as an adaptive or maladaptive physiological response. Additional research is required to determine the efficacy of antioxidant supplementation to minimise exercise-stress during intensive training and promote an adaptive state. PMID:25398224

  3. Ozone therapy on rats submitted to subtotal nephrectomy: role of antioxidant system.

    PubMed

    Calunga, José Luis; Zamora, Zullyt B; Borrego, Aluet; Río, Sarahí del; Barber, Ernesto; Menéndez, Silvia; Hernández, Frank; Montero, Teresita; Taboada, Dunia

    2005-08-31

    Chronic renal failure (CRF) represents a world health problem. Ozone increases the endogenous antioxidant defense system, preserving the cell redox state. The aim of this study is to evaluate the effect of ozone/oxygen mixture in the renal function, morphology, and biochemical parameters, in an experimental model of CRF (subtotal nephrectomy). Ozone/oxygen mixture was applied daily, by rectal insufflation (0.5 mg/kg) for 15 sessions after the nephrectomy. Renal function was evaluated, as well as different biochemical parameters, at the beginning and at the end of the study (10 weeks). Renal plasmatic flow (RPF), glomerular filtration rate (GFR), the urine excretion index, and the sodium and potassium excretions (as a measurement of tubular function) in the ozone group were similar to those in Sham group. Nevertheless, nephrectomized rats without ozone (positive control group) showed the lowest RPF, GFR, and urine excretion figures, as well as tubular function. Animals treated with ozone showed systolic arterial pressure (SAP) figures lower than those in the positive control group, but higher values compared to Sham group. Serum creatinine values and protein excretion in 24 hours in the ozone group were decreased compared with nephrectomized rats, but were still higher than normal values. Histological study demonstrated that animals treated with ozone showed less number of lesions in comparison with nephrectomized rats. Thiobarbituric acid reactive substances were significantly increased in nephrectomized and ozone-treated nephrectomized rats in comparison with Sham group. In the positive control group, superoxide dismutase (SOD) and catalase (CAT) showed the lowest figures in comparison with the other groups. However, ozone/oxygen mixture induced a significant stimulation in the enzymatic activity of CAT, SOD, and glutathione peroxidase, as well as reduced glutathione in relation with Sham and positive control groups. In this animal model of CRF, ozone rectal

  4. Ozone Therapy on Rats Submitted to Subtotal Nephrectomy: Role of Antioxidant System

    PubMed Central

    Calunga, José Luis; Zamora, Zullyt B.; Borrego, Aluet; del Río, Sarahí; Barber, Ernesto; Menéndez, Silvia; Hernández, Frank; Montero, Teresita; Taboada, Dunia

    2005-01-01

    Chronic renal failure (CRF) represents a world health problem. Ozone increases the endogenous antioxidant defense system, preserving the cell redox state. The aim of this study is to evaluate the effect of ozone/oxygen mixture in the renal function, morphology, and biochemical parameters, in an experimental model of CRF (subtotal nephrectomy). Ozone/oxygen mixture was applied daily, by rectal insufflation (0.5 mg/kg) for 15 sessions after the nephrectomy. Renal function was evaluated, as well as different biochemical parameters, at the beginning and at the end of the study (10 weeks). Renal plasmatic flow (RPF), glomerular filtration rate (GFR), the urine excretion index, and the sodium and potassium excretions (as a measurement of tubular function) in the ozone group were similar to those in Sham group. Nevertheless, nephrectomized rats without ozone (positive control group) showed the lowest RPF, GFR, and urine excretion figures, as well as tubular function. Animals treated with ozone showed systolic arterial pressure (SAP) figures lower than those in the positive control group, but higher values compared to Sham group. Serum creatinine values and protein excretion in 24 hours in the ozone group were decreased compared with nephrectomized rats, but were still higher than normal values. Histological study demonstrated that animals treated with ozone showed less number of lesions in comparison with nephrectomized rats. Thiobarbituric acid reactive substances were significantly increased in nephrectomized and ozone-treated nephrectomized rats in comparison with Sham group. In the positive control group, superoxide dismutase (SOD) and catalase (CAT) showed the lowest figures in comparison with the other groups. However, ozone/oxygen mixture induced a significant stimulation in the enzymatic activity of CAT, SOD, and glutathione peroxidase, as well as reduced glutathione in relation with Sham and positive control groups. In this animal model of CRF, ozone rectal

  5. The stimulatory effect of the octadecaneuropeptide ODN on astroglial antioxidant enzyme systems is mediated through a GPCR

    PubMed Central

    Hamdi, Yosra; Kaddour, Hadhemi; Vaudry, David; Douiri, Salma; Bahdoudi, Seyma; Leprince, Jérôme; Castel, Hélène; Vaudry, Hubert; Amri, Mohamed; Tonon, Marie-Christine; Masmoudi-Kouki, Olfa

    2012-01-01

    Astroglial cells possess an array of cellular defense systems, including superoxide dismutase (SOD) and catalase antioxidant enzymes, to prevent damage caused by oxidative stress on the central nervous system. Astrocytes specifically synthesize and release endozepines, a family of regulatory peptides including the octadecaneuropeptide (ODN). ODN is the ligand of both central-type benzodiazepine receptors (CBR), and an adenylyl cyclase- and phospholipase C-coupled receptor. We have recently shown that ODN is a potent protective agent that prevents hydrogen peroxide (H2O2)-induced inhibition of SOD and catalase activities and stimulation of cell apoptosis in astrocytes. The purpose of the present study was to investigate the type of receptor involved in ODN-induced inhibition of SOD and catalase in cultured rat astrocytes. We found that ODN induced a rapid stimulation of SOD and catalase gene transcription in a concentration-dependent manner. In addition, 0.1 nM ODN blocked H2O2-evoked reduction of both mRNA levels and activities of SOD and catalase. Furthermore, the inhibitory actions of ODN on the deleterious effects of H2O2 on SOD and catalase were abrogated by the metabotropic ODN receptor antagonist cyclo1-8[Dleu5]OP, but not by the CBR antagonist flumazenil. Finally, the protective action of ODN against H2O2-evoked inhibition of endogenous antioxidant systems in astrocytes was protein kinase A (PKA)-dependent, but protein kinase C-independent. Taken together, these data demonstrate for the first time that ODN, acting through its metabotropic receptor coupled to the PKA pathway, prevents oxidative stress-induced alteration of antioxidant enzyme expression and activities. The peptide ODN is thus a potential candidate for the development of specific agonists that would selectively mimic its protective activity. PMID:23181054

  6. Changes in ultrastructure and responses of antioxidant systems of algae (Dunaliella salina) during acclimation to enhanced ultraviolet-B radiation.

    PubMed

    Tian, Jiyuan; Yu, Juan

    2009-12-01

    Because of depletion of the stratospheric ozone layer, levels of solar ultraviolet-B (UV-B) radiation (280-315 nm), which penetrates the water column to an ecologically-significant depth, are increasing. In order to assess changes in ultrastructure and responses of antioxidant systems of algae during acclimation to enhanced ultraviolet-B radiation, Dunaliella salina was treated with higher dose of UV-B radiation (13.2 kJm(-2) d(-1) dose) in this study. As compared to the control panel (8.8 kJm(-2) d(-1)), the treatment D. salina had many changes in ultrastructures: (1) thylakoids became swelled, and some of them penetrated into the pyrenoid; (2) lipid globules accumulated; (3) the amounts of starch grains increased; (4) cristae of mitochondria disintegrated; (5) inclusions in vacuoles reduced; and (6) cisternae of Golgi dictyosomes became loose and swollen. Enhanced UV-B irradiation also induced different responses of the antioxidant systems in D. salina: (1) contents of TBARS (thiobarbituric acid reacting substance) and H(2)O(2) increased significantly (p<0.05); (2) levels of MAAs (mycosporine-like amino acids) increased at the beginning and subsequently decreased, and finally they leveled off at lower values; (3) there were not apparent variations for carotenoid contents, and contents of chlorophyll a presented a trend of initial increase and ultimate decrease; (4) both ascorbate and glutathione contents increased significantly (p<0.05); and (5) for the enzyme activities, POD activities increased remarkably (p<0.05), and SOD activities declined apparently (p<0.05), and CAT activity in D. salina had slight variations (p>0.05). In addition, growth curve displayed that enhanced UV-B radiation prominently inhibited increase of cell concentration when compared with control panel (p<0.05). Our results indicated that enhanced UV-B radiation caused ultrastructural changes of D. salina and induced different responses of antioxidant systems in D. salina. PMID:19818642

  7. Dissecting the integrative antioxidant and redox systems in plant mitochondria. Effect of stress and S-nitrosylation

    PubMed Central

    Lázaro, Juan J.; Jiménez, Ana; Camejo, Daymi; Iglesias-Baena, Iván; Martí, María del Carmen; Lázaro-Payo, Alfonso; Barranco-Medina, Sergio; Sevilla, Francisca

    2013-01-01

    Mitochondrial respiration provides the energy needed to drive metabolic and transport processes in cells. Mitochondria are a significant site of reactive oxygen species (ROS) production in plant cells, and redox-system components obey fine regulation mechanisms that are essential in protecting the mitochondrial integrity. In addition to ROS, there are compelling indications that nitric oxide can be generated in this organelle by both reductive and oxidative pathways. ROS and reactive nitrogen species play a key role in signaling but they can also be deleterious via oxidation of macromolecules. The high production of ROS obligates mitochondria to be provided with a set of ROS scavenging mechanisms. The first line of mitochondrial antioxidants is composed of superoxide dismutase and the enzymes of the ascorbate-glutathione cycle, which are not only able to scavenge ROS but also to repair cell damage and possibly serve as redox sensors. The dithiol-disulfide exchanges form independent signaling nodes and act as antioxidant defense mechanisms as well as sensor proteins modulating redox signaling during development and stress adaptation. The presence of thioredoxin (Trx), peroxiredoxin (Prx) and sulfiredoxin (Srx) in the mitochondria has been recently reported. Cumulative results obtained from studies in salt stress models have demonstrated that these redox proteins play a significant role in the establishment of salt tolerance. The Trx/Prx/Srx system may be subjected to a fine regulated mechanism involving post-translational modifications, among which S-glutathionylation and S-nitrosylation seem to exhibit a critical role that is just beginning to be understood. This review summarizes our current knowledge in antioxidative systems in plant mitochondria, their interrelationships, mechanisms of compensation and some unresolved questions, with special focus on their response to abiotic stress. PMID:24348485

  8. Specificity in Mesograzer-Induced Defences in Seagrasses.

    PubMed

    Martínez-Crego, Begoña; Arteaga, Pedro; Ueber, Alexandra; Engelen, Aschwin H; Santos, Rui; Molis, Markus

    2015-01-01

    Grazing-induced plant defences that reduce palatability to herbivores are widespread in terrestrial plants and seaweeds, but they have not yet been reported in seagrasses. We investigated the ability of two seagrass species to induce defences in response to direct grazing by three associated mesograzers. Specifically, we conducted feeding-assayed induction experiments to examine how mesograzer-specific grazing impact affects seagrass induction of defences within the context of the optimal defence theory. We found that the amphipod Gammarus insensibilis and the isopod Idotea chelipes exerted a low-intensity grazing on older blades of the seagrass Cymodocea nodosa, which reflects a weak grazing impact that may explain the lack of inducible defences. The isopod Synischia hectica exerted the strongest grazing impact on C. nodosa via high-intensity feeding on young blades with a higher fitness value. This isopod grazing induced defences in C. nodosa as indicated by a consistently lower consumption of blades previously grazed for 5, 12 and 16 days. The lower consumption was maintained when offered tissues with no plant structure (agar-reconstituted food), but showing a reduced size of the previous grazing effect. This indicates that structural traits act in combination with chemical traits to reduce seagrass palatability to the isopod. Increase in total phenolics but not in C:N ratio and total nitrogen of grazed C. nodosa suggests chemical defences rather than a modified nutritional quality as primarily induced chemical traits. We detected no induction of defences in Zostera noltei, which showed the ability to replace moderate losses of young biomass to mesograzers via compensatory growth. Our study provides the first experimental evidence of induction of defences against meso-herbivory that reduce further consumption in seagrasses. It also emphasizes the relevance of grazer identity in determining the level of grazing impact triggering resistance and compensatory

  9. Specificity in Mesograzer-Induced Defences in Seagrasses

    PubMed Central

    Martínez-Crego, Begoña; Arteaga, Pedro; Ueber, Alexandra; Engelen, Aschwin H.; Santos, Rui; Molis, Markus

    2015-01-01

    Grazing-induced plant defences that reduce palatability to herbivores are widespread in terrestrial plants and seaweeds, but they have not yet been reported in seagrasses. We investigated the ability of two seagrass species to induce defences in response to direct grazing by three associated mesograzers. Specifically, we conducted feeding-assayed induction experiments to examine how mesograzer-specific grazing impact affects seagrass induction of defences within the context of the optimal defence theory. We found that the amphipod Gammarus insensibilis and the isopod Idotea chelipes exerted a low-intensity grazing on older blades of the seagrass Cymodocea nodosa, which reflects a weak grazing impact that may explain the lack of inducible defences. The isopod Synischia hectica exerted the strongest grazing impact on C. nodosa via high-intensity feeding on young blades with a higher fitness value. This isopod grazing induced defences in C. nodosa as indicated by a consistently lower consumption of blades previously grazed for 5, 12 and 16 days. The lower consumption was maintained when offered tissues with no plant structure (agar-reconstituted food), but showing a reduced size of the previous grazing effect. This indicates that structural traits act in combination with chemical traits to reduce seagrass palatability to the isopod. Increase in total phenolics but not in C:N ratio and total nitrogen of grazed C. nodosa suggests chemical defences rather than a modified nutritional quality as primarily induced chemical traits. We detected no induction of defences in Zostera noltei, which showed the ability to replace moderate losses of young biomass to mesograzers via compensatory growth. Our study provides the first experimental evidence of induction of defences against meso-herbivory that reduce further consumption in seagrasses. It also emphasizes the relevance of grazer identity in determining the level of grazing impact triggering resistance and compensatory

  10. Antioxidant properties of 4-methylcoumarins in in vitro cell-free systems.

    PubMed

    Morabito, Giuseppa; Trombetta, Domenico; Singh Brajendra, K; Prasad Ashok, K; Parmar Virinder, S; Naccari, Clara; Mancari, Ferdinando; Saija, Antonina; Cristani, Mariateresa; Firuzi, Omidreza; Saso, Luciano

    2010-09-01

    4-methylcoumarins that possess two hydroxyl groups ortho to each other in the benzenoid ring have shown to have excellent antioxidant and radical-scavenging properties in different experimental models. Furthermore, they cannot be metabolized by the liver P450 monoxygenases and thus cannot form 3,4-coumarin epoxides, which are believed to be mutagenic. Herein, we present a study on the structure activity relationship of eight synthetic 4-methylcoumarins, carried out by employing a series of different chemical cell-free tests. These compounds were tested by means of three assays involving one redox reaction with the oxidant (DPPH assay, ABTS.+ assay and FRAP). Other assays were employed to evaluate the antioxidant properties of the coumarins under investigation against NO, O2.- and HClO, which are some of the major reactive oxygen and nitrogen species causing damage in the human body. Finally, we have measured the protective capacity of these coumarins against the oxidative damage in a simple biomimetic model of phospholipid membranes. Our results confirm the good antioxidant activity of the 7,8-hydroxy-4-methylcoumarins. In general, their activity is not significantly affected by the introduction of an ethoxycarbonylmethyl or an ethoxycarbonylethyl moiety at the C3 position. A discrete antioxidant activity is retained also by the 7,8-diacetoxy-4-methylcoumarins, although they are less efficient than the corresponding 7,8-dihydroxy compounds. Furthermore, as demonstrated in the brine shrimp toxicity test, none of the tested coumarins significantly affect the larvae viability. Two of the 4-methylcoumarins (7,8-dihydroxy-4-methylcoumarin and 7,8-dihydroxy-3-ethoxycarbonylethyl-4-methylcoumarin), very interestingly, showed strong scavenging activities against the superoxide anion and were also very effective in protecting the lipid bilayer against peroxidation. On the basis of these findings, these 4-methylcoumarins may be considered as potential therapeutic candidates

  11. Physicochemical properties and antioxidant potential of phosvitin-resveratrol complexes in emulsion system.

    PubMed

    Duan, Xiang; Li, Mei; Ma, Huijie; Xu, Xueming; Jin, Zhengyu; Liu, Xuebo

    2016-09-01

    Egg yolk phosvitin is the most highly phosphorylated protein found in the nature. The physicochemical properties of phosvitin-resveratrol complexes and their synergistic antioxidant activities in microemulsions were investigated. The particle diameters of microemulsions containing 0.5%, 1.0% and 2.0% phosvitin were 2.660, 0.501 and 0.414μm, respectively. The emulsifying activity index increased largely from 3.72 to 21.5m(2)/g with increasing phosvitin concentration from 0.5% to 2.0%. Fourier transform infrared spectroscopy and thermal analyses indicated that the microemulsions underwent a conformational change during homogenization. Antioxidant assays showed that phosvitin-resveratrol microemulsions exhibited a higher antioxidant activity than that of phosvitin-resveratrol primary emulsions. The MTT assay indicated that HepG2 cell viability remained higher than 80% at phosvitin concentration below 1.0mg/ml. This suggested that phosvitin, when coupled with polyphenol, can effectively inhibit lipid oxidation in food emulsions, which provided valuable insights into deep processing and application of egg proteins in food industry. PMID:27041304

  12. Antioxidant Systems are Regulated by Nitric Oxide-Mediated Post-translational Modifications (NO-PTMs)

    PubMed Central

    Begara-Morales, Juan C.; Sánchez-Calvo, Beatriz; Chaki, Mounira; Valderrama, Raquel; Mata-Pérez, Capilla; Padilla, María N.; Corpas, Francisco J.; Barroso, Juan B.

    2016-01-01

    Nitric oxide (NO) is a biological messenger that orchestrates a plethora of plant functions, mainly through post-translational modifications (PTMs) such as S-nitrosylation or tyrosine nitration. In plants, hundreds of proteins have been identified as potential targets of these NO-PTMs under physiological and stress conditions indicating the relevance of NO in plant-signaling mechanisms. Among these NO protein targets, there are different antioxidant enzymes involved in the control of reactive oxygen species (ROS), such as H2O2, which is also a signal molecule. This highlights the close relationship between ROS/NO signaling pathways. The major plant antioxidant enzymes, including catalase, superoxide dismutases (SODs) peroxiredoxins (Prx) and all the enzymatic components of the ascorbate-glutathione (Asa-GSH) cycle, have been shown to be modulated to different degrees by NO-PTMs. This mini-review will update the recent knowledge concerning the interaction of NO with these antioxidant enzymes, with a special focus on the components of the Asa-GSH cycle and their physiological relevance. PMID:26909095

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

    PubMed

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

    2015-10-01

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

  14. Influence of droplet size on the antioxidant activity of rosemary extract loaded oil-in-water emulsions in mixed systems.

    PubMed

    Erdmann, Martin E; Zeeb, Benjamin; Salminen, Hanna; Gibis, Monika; Lautenschlaeger, Ralf; Weiss, Jochen

    2015-03-01

    The influence of droplet size on the antioxidant activity of oil-in-water emulsions loaded with rosemary extract in mixed emulsion systems was investigated. Firstly, differently sized hexadecane-in-water model emulsions (10% (w/w) hexadecane, 2% (w/w) Tween 80, pH 5 or 7) containing 4000 ppm rosemary extract in the oil phase or without added antioxidant were prepared using a high shear blender and/or high-pressure homogenizer. Secondly, emulsions were mixed with fish oil-in-water emulsions (10% (w/w) fish oil, 2% (w/w) Tween 80, pH 5 or 7) at a mixing ratio of 1 : 1. Optical microscopy and static light scattering measurements indicated that emulsions were physically stable for 21 days, except for the slight aggregation of emulsions with a mean droplet size d₄₃ of 4500 nm. The droplet size of hexadecane-in-water emulsions containing rosemary extract had no influence on the formation of lipid hydroperoxides at pH 5 and 7. Significantly lower concentrations of propanal were observed for the emulsions loaded with rosemary extract with a mean droplet size d₄₃ of 4500 nm from day 12 to 16 at pH 7. Finally, hexadecane-in-water emulsions containing rosemary extract significantly retarded lipid oxidation of fish oil-in-water emulsions in mixed systems, but no differences in antioxidant efficacy between the differently sized emulsions were observed at pH 5. PMID:25586114

  15. Photosystem II functionality and antioxidant system changes during leaf rolling in post-stress emerging Ctenanthe setosa exposed to drought.

    PubMed

    Terzi, Rabiye; Saruhan, Neslihan; Sağlam, A; Nar, Hatice; Kadioğlu, A

    2009-12-01

    We studied the changes in antioxidant system and chlorophyll fluorescence parameters in post-stress emerging Ctenanthe setosa (Rosc.) Eichler (Marantaceae) plants (PSE plants) having reduced leaf area under drought stress causing leaf rolling and re-watering. PSE plants were compared to primary stressed plants (PS) in previous studies. The parameters were measured at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others is intermediate form). Water potentials and stomatal conductance of leaves were gradually decreased during leaf rolling. Similarly, maximum quantum efficiency of open PS II center and quantum yield of PS II decreased during the rolling period. Non-photochemical quenching of chlorophyll fluorescence decreased at score 2 then increased while photochemical quenching did not change during leaf rolling. Electron transport rate decreased only at score 4 but approximately reached to score 1 level after re-watering. Superoxide dismutase activity was not constant at all leaf rolling scores. Ascorbate peroxidase, catalase and glutathione reductase activities generally tended to increase during leaf rolling. Lipid peroxidation and H 2 O 2 content increased at score 2 but decreased at the later scores. On the other hand, O 2 .- production increased during the rolling period. After re-watering of the plants having score 4 of leaf rolling, antioxidant enzyme activities were lower than those of score 1. Other physiological parameters also tended to reach the value of score 1. The results indicated that PSE plants gained drought tolerance by reducing leaf area effectively induced their antioxidant systems and protected the photosynthesis under drought stress similar to PS plants. PMID:20015833

  16. Antioxidant role of amyloid β protein in cell-free and biological systems: implication for the pathogenesis of Alzheimer disease.

    PubMed

    Sinha, Maitrayee; Bhowmick, Pritha; Banerjee, Anindita; Chakrabarti, Sasanka

    2013-03-01

    In contrast to many studies showing the pro-oxidative nature of amyloid peptide, this work shows that aggregated Aβ42 peptide in varying concentrations (2-20 μM) in cell-free systems inhibits the formation of hydroxyl radicals and H(2)O(2) from a mixture of iron (20 μM FeSO(4)) and ascorbate (2mM) as measured by benzoate hydroxylation assay and coumarin carboxylic acid assay. Aggregated Aβ42 in similar concentrations further prevents protein and lipid oxidation in isolated rat brain mitochondria incubated alone or with FeSO(4) and ascorbate. Moreover, mitochondria exposed to FeSO(4) and ascorbate show enhanced formation of reactive oxygen species and this phenomenon is also abolished by aggregated Aβ42. It is suggested that the antioxidant property of Aβ42 in various systems is mediated by metal chelation and it is nearly as potent as a typical metal chelator, such as diethylenetriaminepentaacetic acid, in preventing oxidative damage. However, aggregated Aβ42 causes mitochondrial functional impairment in the form of membrane depolarization and a loss of phosphorylation capacity without involving reactive oxygen species in the process. Thus, the present results suggest that the amyloid peptide exhibits a protective antioxidant role in biological systems, but also has toxic actions independent of oxidative stress. PMID:23041348

  17. Exploration of the antioxidant system and photosynthetic system of a marine algicidal Bacillus and its effect on four harmful algal bloom species.

    PubMed

    Hou, Shaoling; Shu, Wanjiao; Tan, Shuo; Zhao, Ling; Yin, Pinghe

    2016-01-01

    A novel marine bacterium, strain B1, initially showed 96.4% algicidal activity against Phaeocystis globosa. Under this situation, 3 other harmful algal species (Skeletonema costatum, Heterosigma akashiwo, and Prorocentrum donghaiense) were chosen to study the algicidal effects of strain B1, and the algicidal activities were 91.4%, 90.7%, and 90.6%, respectively. To explore the algicidal mechanism of strain B1 on these 4 harmful algal species, the characteristics of the antioxidant system and photosynthetic system were studied. Sensitivity to strain B1 supernatant, enzyme activity, and gene expression varied with algal species, while the algicidal patterns were similar. Strain B1 supernatant increased malondialdehyde contents; decreased chlorophyll a contents; changed total antioxidant and superoxide dismutase activity; and restrained psbA, psbD, and rbcL genes expression, which eventually resulted in the algal cells death. The algicidal procedure was observed using field emission scanning electron microscopy, which indicated that algal cells were lysed and cellular substances were released. These findings suggested that the antioxidant and photosynthetic system of these 4 algal species was destroyed under strain B1 supernatant stress. This is the first report to explore and compare the mechanism of a marine Bacillus against harmful algal bloom species of covered 4 phyla. PMID:26634608

  18. Prenatal methylmercury exposure hampers glutathione antioxidant system ontogenesis and causes long-lasting oxidative stress in the mouse brain

    SciTech Connect

    Stringari, James; Nunes, Adriana K.C.; Franco, Jeferson L.; Bohrer, Denise; Garcia, Solange C.; Dafre, Alcir L.; Milatovic, Dejan; Souza, Diogo O.; Rocha, Joao B.T.; Aschner, Michael; Farina, Marcelo

    2008-02-15

    During the perinatal period, the central nervous system (CNS) is extremely sensitive to metals, including methylmercury (MeHg). Although the mechanism(s) associated with MeHg-induced developmental neurotoxicity remains obscure, several studies point to the glutathione (GSH) antioxidant system as an important molecular target for this toxicant. To extend our recent findings of MeHg-induced GSH dyshomeostasis, the present study was designed to assess the developmental profile of the GSH antioxidant system in the mouse brain during the early postnatal period after in utero exposure to MeHg. Pregnant mice were exposed to different doses of MeHg (1, 3 and 10 mg/l, diluted in drinking water, ad libitum) during the gestational period. After delivery, pups were killed at different time points - postnatal days (PND) 1, 11 and 21 - and the whole brain was used for determining biochemical parameters related to the antioxidant GSH system, as well as mercury content and the levels of F{sub 2}-isoprostane. In control animals, cerebral GSH levels significantly increased over time during the early postnatal period; gestational exposure to MeHg caused a dose-dependent inhibition of this developmental event. Cerebral glutathione peroxidase (GPx) and glutathione reductase (GR) activities significantly increased over time during the early postnatal period in control animals; gestational MeHg exposure induced a dose-dependent inhibitory effect on both developmental phenomena. These adverse effects of prenatal MeHg exposure were corroborated by marked increases in cerebral F{sub 2}-isoprostanes levels at all time points. Significant negative correlations were found between F{sub 2}-isoprostanes and GSH, as well as between F{sub 2}-isoprostanes and GPx activity, suggesting that MeHg-induced disruption of the GSH system maturation is related to MeHg-induced increased lipid peroxidation in the pup brain. In utero MeHg exposure also caused a dose-dependent increase in the cerebral levels of

  19. Two modalities of manic defences: their function in adolescent breakdown.

    PubMed

    Bronstein, Catalina

    2010-06-01

    The aim of this paper is to explore two different modalities of manic defences and their specific underlying anxieties. I will describe the relation between these defences and the role of the superego and their specific function in adolescent breakdown. While one type of manic defence operates by the ego's identification with a sadistic superego the other one operates via evacuation of a guilt-inducing superego. I will illustrate the proposed ideas with clinical examples from the analysis of two adolescents. This paper stresses the specific differences between these two modalities and the clinical importance of both identifying and addressing the enactment in the transference of the unconscious phantasies and anxieties (paranoid and depressive) that give rise to these two types of defences. PMID:20590929

  20. Change of antioxidant enzymes activity of hazel (Corylus avellana L.) cells by AgNPs.

    PubMed

    Jamshidi, Mitra; Ghanati, Faezeh; Rezaei, Ayatollah; Bemani, Ebrahim

    2016-05-01

    Elicitation effect of silver nano particles (AgNPs) and triggering of defence system by production of hydrogen peroxide (H2O2) as a signaling molecule in the regulation of the activity of stress-related enzymes and production of Taxol was evaluated in suspension- cultured hazel cells (Corylus avellana L.). The cells were treated with different concentrations of AgNPs (0, 2.5, 5, and 10 ppm), in their logarithmic growth phase (d7) and were harvested after 1 week. Treatment of hazel cells with AgNPs decreased the viability of the cells. Also the results showed that while the activity of certain radical scavenging enzymes in particular of catalase and peroxidase increased by 2.5 and 5 ppm AgNPs, the activity of superoxide dismutase decreased in these treatments. The highest activity of ascorbate peroxidase was observed in 10 ppm AgNPs treatments. This treatment also showed the highest contents of H2O2 and phenolic compounds, as well as the highest activity of phenylalanine ammonialyase. According to the results, 5 ppm AgNPs was the best concentration for elicitation of hazel cells to produce efficient amounts of H2O2 in order for stimulation of antioxidant defence system, production of Taxol at the highest capacity of the cells, meanwhile reserving their viability. PMID:25404256

  1. Pulmonary antioxidants

    SciTech Connect

    Massaro, E.J.; Grose, E.C.; Hatch, G.E.; Slade, R.

    1987-05-01

    One of the most vital of the cellular defenses against pollution is an antioxidant armanentarium which consists of oxidant scavenging molecules such as vitamin E, glutathione, vitamin C, and uric acid as well as a number of enzymes (superoxide dismutase, semidehydroascorbate reductase, catalase, GSH synthetase, GSH peroxidase, GSH reductase, and GSH transferase) and appears to function in keeping oxidant forces under control. Pollutants can upset the oxidant/antioxidant balance of cells by inhibiting vital enzymes, by reacting with oxidant scavengers, or by forming free radical intermediates which initiate uncontrolled tissue reactions with molecular oxygen. The book chapter reviews possible interactions between pollutants and the oxidant/antioxidant balance.

  2. Role of stress-related hormones in plant defence during early infection of the cyst nematode Heterodera schachtii in Arabidopsis

    PubMed Central

    Kammerhofer, Nina; Radakovic, Zoran; Regis, Jully M A; Dobrev, Petre; Vankova, Radomira; Grundler, Florian M W; Siddique, Shahid; Hofmann, Julia; Wieczorek, Krzysztof

    2015-01-01

    Heterodera schachtii, a plant-parasitic cyst nematode, invades host roots and induces a specific syncytial feeding structure, from which it withdraws all required nutrients, causing severe yield losses. The system H. schachtii–Arabidopsis is an excellent research model for investigating plant defence mechanisms. Such responses are suppressed in well-established syncytia, whereas they are induced during early parasitism. However, the mechanisms by which the defence responses are modulated and the role of phytohormones are largely unknown. The aim of this study was to elucidate the role of hormone-based defence responses at the onset of nematode infection. First, concentrations of main phytohormones were quantified and the expression of several hormone-related genes was analysed using quantitative real-time (qRT)-PCR or GeneChip. Further, the effects of individual hormones were evaluated via nematode attraction and infection assays using plants with altered endogenous hormone concentrations. Our results suggest a pivotal and positive role for ethylene during nematode attraction, whereas jasmonic acid triggers early defence responses against H. schachtii. Salicylic acid seems to be a negative regulator during later syncytium and female development. We conclude that nematodes are able to impose specific changes in hormone pools, thus modulating hormone-based defence and signal transduction in strict dependence on their parasitism stage. PMID:25825039

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

    PubMed Central

    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

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

    PubMed

    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

  5. Regulation of the antioxidant system in cells of the fission yeast Schizosaccharomyces pombe after combined treatment with patulin and citrinin.

    PubMed

    Papp, Gábor; Máté, Gábor; Mike, Nóra; Gazdag, Zoltán; Pesti, Miklós

    2016-03-01

    The effects of combined treatment with patulin (PAT) and citrinin (CTN) on Schizosaccharomyces pombe cells were investigated in acute toxicity tests. In comparison with the controls the exposure of fission yeast cells (10(7) cells ml(-1)) to PAT + CTN (250 μM each) for 1 h at a survival rate of 66.6% significantly elevated the concentration of total reactive oxygen species (ROS) via increased levels of peroxides without affecting the concentrations of superoxides or the hydroxyl radical. This treatment induced a 3.08-fold increase in the specific concentration of glutathione and elevated specific activities of catalase and glutathione S-transferase, while at the same time the activity of glutathione reductase decreased. The pattern of the ROS was the same as that induced by CTN (Máté et al., 2014), while the presence of PAT in the PAT + CTN combination treatment modified the activities of the antioxidant system (Papp et al., 2012) in comparison with the individual PAT or CTN treatment, suggesting toxin-specific regulation of glutathione and the enzymes of the antioxidant system and the possibility that the transcription factor (pap1 and atf1) -regulated processes might be influenced directly by ROS. PMID:26752674

  6. Between-Population Outbreeding Affects Plant Defence

    PubMed Central

    Leimu, Roosa; Fischer, Markus

    2010-01-01

    Between-population crosses may replenish genetic variation of populations, but may also result in outbreeding depression. Apart from direct effects on plant fitness, these outbreeding effects can also alter plant-herbivore interactions by influencing plant tolerance and resistance to herbivory. We investigated effects of experimental within- and between-population outbreeding on herbivore resistance, tolerance and plant fitness using plants from 13 to 19 Lychnis flos-cuculi populations. We found no evidence for outbreeding depression in resistance reflected by the amount of leaf area consumed. However, herbivore performance was greater when fed on plants from between-population compared to within-population crosses. This can reflect outbreeding depression in resistance and/or outbreeding effects on plant quality for the herbivores. The effects of type of cross on the relationship between herbivore damage and plant fitness varied among populations. This demonstrates how between-population outbreeding effects on tolerance range from outbreeding depression to outbreeding benefits among plant populations. Finally, herbivore damage strengthened the observed outbreeding effects on plant fitness in several populations. These results raise novel considerations on the impact of outbreeding on the joint evolution of resistance and tolerance, and on the evolution of multiple defence strategies. PMID:20838662

  7. Salinity change impairs pipefish immune defence.

    PubMed

    Birrer, Simone C; Reusch, Thorsten B H; Roth, Olivia

    2012-12-01

    Global change is associated with fast and severe alterations of environmental conditions. Superimposed onto existing salinity variations in a semi-enclosed brackish water body such as the Baltic Sea, a decrease in salinity is predicted due to increased precipitation and freshwater inflow. Moreover, we predict that heavy precipitation events will accentuate salinity fluctuations near shore. Here, we investigated how the immune function of the broad-nosed pipefish (Syngnathus typhle), an ecologically important teleost with sex-role reversal, is influenced by experimentally altered salinities (control: 18 PSU, lowered: 6 PSU, increased: 30 PSU) upon infection with bacteria of the genus Vibrio. Salinity changes resulted in increased activity and proliferation of immune cells. However, upon Vibrio infection, individuals at low salinity were unable to mount specific immune response components, both in terms of monocyte and lymphocyte cell proliferation and immune gene expression compared to pipefish kept at ambient salinities. We interpret this as resource allocation trade-off, implying that resources needed for osmoregulation under salinity stress are lacking for subsequent activation of the immune defence upon infection. Our data suggest that composition of small coastal fish communities may change due to elevated environmental stress levels and the incorporated consequences thereof. PMID:22982326

  8. Middle Devonian liverwort herbivory and antiherbivore defence.

    PubMed

    Labandeira, Conrad C; Tremblay, Susan L; Bartowski, Kenneth E; VanAller Hernick, Linda

    2014-04-01

    To test the extent of herbivory in early terrestrial ecosystems, we examined compression-impression specimens of the late Middle Devonian liverwort Metzgeriothallus sharonae, from the Catskill Delta deposit of eastern New York state. Shale fragments of field-collected specimens were processed by applying liquid nitrocellulose on exposed surfaces. After drying, the film coatings were lifted off and mounted on microscope slides for photography. Unprocessed fragments were photographed under cedarwood oil for enhanced contrast. An extensive repertoire of arthropodan-mediated herbivory was documented, representing three functional feeding groups and nine subordinate plant-arthropod damage types (DTs). The herbivory is the earliest occurrence of external foliage-feeding and galling in the terrestrial fossil record. Our evidence indicates that thallus oil body cells, similar to the terpenoid-containing oil bodies of modern liverworts, were probably involved in the chemical defence of M. sharonae against arthropod herbivores. Based on damage patterns of terrestrial plants and an accompanying but sparse body-fossil record, Devonian arthropodan herbivores were significantly smaller compared to those of the later Palaeozoic. These data collectively suggest that a broad spectrum herbivory may have had a more important role in early terrestrial ecosystems than previously thought. PMID:24372344

  9. Simulation, human factors and defence anaesthesia.

    PubMed

    Mercer, S J; Whittle, C; Siggers, B; Frazer, R S

    2010-12-01

    Simulation in healthcare has come a long way since it's beginnings in the 1960s. Not only has the sophistication of simulator design increased, but the educational concepts of simulation have become much clearer. One particularly important area is that of non-technical skills (NTS) which has been developed from similar concepts in the aviation and nuclear industries. NTS models have been developed for anaesthetists and more recently for surgeons too. This has clear value for surgical team working and the recently developed Military Operational Surgical Training (MOST) course uses simulation and NTS to improve such team working. The scope for simulation in Defence medicine and anaesthesia does not stop here. Uses of simulation include pre-deployment training of hospital teams as well as Medical Emergency Response Team (MERT) and Critical Care Air Support Team (CCAST) staff. Future projects include developing Role 1 pre-deployment training. There is enormous scope for development in this important growth area of education and training. PMID:21302658

  10. Lycopene modulates initiation of N-nitrosodiethylamine induced hepatocarcinogenesis: studies on chromosomal abnormalities, membrane fluidity and antioxidant defense system.

    PubMed

    Gupta, Prachi; Bansal, Mohinder Pal; Koul, Ashwani

    2013-11-25

    Oxidative damage due to free radicals generated during nitrosamine metabolism has been suggested as one of the major cause for the initiation of hepatocarcinogenesis. Lycopene, is a well known antioxidant and have promising preventive potentials, however the mechanism of action remain hypothetical and unclear. To investigate the involvement of lycopene extracted from tomatoes (LycT) against oxidative stress induced deleterious effect of N-nitrosodiethylamine (NDEA) on cellular macromolecules, female Balb/c mice were divided in four groups: Control, NDEA (cumulative dose of 200mg NDEA/kg body weight injected intraperitoneally in 8 weeks), LycT (5mg/kg body weight given orally on alternate days, throughout the study) and LycT+NDEA (co-administration of LycT and NDEA). NDEA treatment commenced after 2 weeks of LycT administration. At the end of NDEA exposure i.e., at 10th week, enhanced activities of hepatic phase I enzymes, levels of reactive oxygen species (ROS), lipid peroxidation (LPO) was observed in NDEA group which may have contributed in chromosomal aberrations, enhanced micronucleated cell score, membrane fluidity and serum liver marker enzymes. A significant decrease in enzymatic and non-enzymatic antioxidant system could delineate the mechanism behind such NDEA insults. LycT pre-treatment to NDEA challenged group showed lower chromosomal abnormalities, micronucleated cells score, ROS, LPO levels and liver enzymes. Lycopene aids in normalizing the membrane fluidity and enhancing the activity of antioxidant enzymes and reduced glutathione which could account for the reduced oxidative damage in LycT+NDEA group. It seemed that lycopene supplementation target multiple dys-regulated pathways during initiation of carcinogenesis. Thus, dietary supplementation with lycopene can serve as an alternate measure to intervene the initiation of carcinogenesis. PMID:24144777

  11. Bentazon triggers the promotion of oxidative damage in the Portuguese ricefield cyanobacterium Anabaena cylindrica: response of the antioxidant system.

    PubMed

    Galhano, Victor; Peixoto, Francisco; Gomes-Laranjo, José

    2010-10-01

    Rice fields are frequently exposed to environmental contamination by herbicides and cyanobacteria, as primary producers of these aquatic ecosystems, are adversely affected. Anabaena cylindrica is a cyanobacterium with a significantly widespread occurrence in Portuguese rice fields. This strain was studied throughout 72 h in laboratory conditions for its stress responses to sublethal concentrations (0.75-2 mM) of bentazon, a selective postemergence herbicide recommended for integrated weed management in rice, with special reference to oxidative stress, role of proline and intracellular antioxidant enzymes in herbicide-induced free radicals detoxification. Activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione S-transferase (GST) increased in a time- and herbicide dose-response manner and were higher than those in the control samples after 72 h. A time- and concentration-dependent increase of malondialdehyde (MDA) levels and the enhanced cell membrane leakage following bentazon exposure are indicative of lipid peroxidation, free radicals formation, and oxidative damage, while increased amounts of SOD, CAT, APX, GST, and proline indicated their involvement in free radical scavenging mechanisms. The appreciable decline in the reduced glutathione (GSH) pool after 72 h at higher bentazon concentrations could be explained by the reduction of the NADPH-dependent glutathione reductase (GR) activity. The obtained results suggested that the alterations of antioxidant systems in A. cylindrica might be useful biomarkers of bentazon exposure. As the toxic mechanism of bentazon is a complex phenomenon, this study also adds relevant findings to explain the oxidative stress pathways of bentazon promoting oxidative stress in cyanobacteria. PMID:20549627

  12. Triacontanol Reduces Transplanting Shock in Machine-Transplanted Rice by Improving the Growth and Antioxidant Systems

    PubMed Central

    Li, Xiaochun; Zhong, Qiuyi; Li, Yuxiang; Li, Ganghua; Ding, Yanfeng; Wang, Shaohua; Liu, Zhenghui; Tang, She; Ding, Chengqiang; Chen, Lin

    2016-01-01

    Machine transplantation results in serious transplant shock in seedlings and results in a longer recover stage, which negatively impacts the growth of low-position tillers and the yield of machine-transplanted rice. A barrel experiment was conducted to examine the effect of the foliar application of triacontanol (TRIA) on machine-transplanted rice during the recovery stage. TRIA (0, 1, 5, and 10 μM) was sprayed over leaves 2 days before transplanting. The chlorophyll content, sucrose content, oxidative damage, antioxidant enzyme levels, glutathione (GSH), and ascorbate (ASA) redox states, tiller dynamics and yield components of the plants were investigated. The results show that foliar-applied TRIA significantly alleviates the growth inhibition and oxidative damage caused by transplant shock. Furthermore, the application of TRIA increased the chlorophyll and sucrose contents of the plants. Importantly, TRIA not only significantly improved the activity of catalase (CAT) and guaiacol peroxidase (POD), demonstrating that POD can play an important role in scavenging H2O2 during the recovery stage, but it also enhanced the redox states of ASA and GSH by regulating the activities of enzymes involved in the ASA–GSH cycle, such as ascorbate peroxidase (APX) and glutathione reductase (GR). A dose of 10 μM TRIA was the most efficient in reducing the negative effects of transplant shock, increasing the panicles, grain filling, and grain yield per hill by 17.80, 5.86, and 16.49%, respectively. These results suggest that TRIA acts to reduce transplant shock in association with the regulation of the redox states of ASA and GSH and antioxidant enzymes and serves as an effective antioxidant to maintain photosynthetic capacity and promote the occurrence of low tillers. PMID:27379149

  13. Biomonitoring of air pollution using antioxidative enzyme system in two genera of family Pottiaceae (Bryophyta).

    PubMed

    Bansal, Pooja; Verma, Sonam; Srivastava, Alka

    2016-09-01

    Bryophyte particularly mosses, have been found to serve as reliable indicators of air pollution and can serve as bryometers-biological instruments for measuring air pollution. They are remarkable colonizers, as they have the ability to survive in adverse environments and are also particular in their requirement of environmental conditions, which makes them appropriate ecological indicators. The purpose of this study was to evaluate the activity of antioxidative enzymes in two mosses viz., Hyophila rosea R.S. Williams and Semibarbula orientalis (Web.) Wijk. & Marg. and assess their suitability as biomonitors. Three different locations viz., Lucknow University, Residency (contaminated sites) and Dilkusha Garden (reference site) within Lucknow city with different levels of air pollutants were used for comparison. Our results indicate that air pollution caused marked enhancement in activity of antioxidative enzymes viz., catalase, peroxidase and superoxide dismutase. All the three are capable of scavenging reactive oxygen species. In the genus S. orientalis, catalase, peroxidase and superoxide dismutase activity was minimum at the reference site Dilkusha Garden and was significantly higher at the two contaminated sites for catalase and peroxidase, whereas the difference was non significant for superoxide dismutase. In H. rosea the activity of catalase and peroxidase at the three locations was almost similar, however superoxide dismutase activity showed a significant increase in the two contaminated sites when compared to the reference site, the value being highest for Lucknow University site. It was thus observed that the two genera, from the same location, showed difference in the activity of the antioxidative enzymes. Based on our results, we recommend bryophytes as good monitors of air pollution. PMID:27321879

  14. Triacontanol Reduces Transplanting Shock in Machine-Transplanted Rice by Improving the Growth and Antioxidant Systems.

    PubMed

    Li, Xiaochun; Zhong, Qiuyi; Li, Yuxiang; Li, Ganghua; Ding, Yanfeng; Wang, Shaohua; Liu, Zhenghui; Tang, She; Ding, Chengqiang; Chen, Lin

    2016-01-01

    Machine transplantation results in serious transplant shock in seedlings and results in a longer recover stage, which negatively impacts the growth of low-position tillers and the yield of machine-transplanted rice. A barrel experiment was conducted to examine the effect of the foliar application of triacontanol (TRIA) on machine-transplanted rice during the recovery stage. TRIA (0, 1, 5, and 10 μM) was sprayed over leaves 2 days before transplanting. The chlorophyll content, sucrose content, oxidative damage, antioxidant enzyme levels, glutathione (GSH), and ascorbate (ASA) redox states, tiller dynamics and yield components of the plants were investigated. The results show that foliar-applied TRIA significantly alleviates the growth inhibition and oxidative damage caused by transplant shock. Furthermore, the application of TRIA increased the chlorophyll and sucrose contents of the plants. Importantly, TRIA not only significantly improved the activity of catalase (CAT) and guaiacol peroxidase (POD), demonstrating that POD can play an important role in scavenging H2O2 during the recovery stage, but it also enhanced the redox states of ASA and GSH by regulating the activities of enzymes involved in the ASA-GSH cycle, such as ascorbate peroxidase (APX) and glutathione reductase (GR). A dose of 10 μM TRIA was the most efficient in reducing the negative effects of transplant shock, increasing the panicles, grain filling, and grain yield per hill by 17.80, 5.86, and 16.49%, respectively. These results suggest that TRIA acts to reduce transplant shock in association with the regulation of the redox states of ASA and GSH and antioxidant enzymes and serves as an effective antioxidant to maintain photosynthetic capacity and promote the occurrence of low tillers. PMID:27379149

  15. EDTA enhanced plant growth, antioxidant defense system, and phytoextraction of copper by Brassica napus L.

    PubMed

    Habiba, Ume; Ali, Shafaqat; Farid, Mujahid; Shakoor, Muhammad Bilal; Rizwan, Muhammad; Ibrahim, Muhammad; Abbasi, Ghulam Hasan; Hayat, Tahir; Ali, Basharat

    2015-01-01

    Copper (Cu) is an essential micronutrient for normal plant growth and development, but in excess, it is also toxic to plants. The present study investigated the influence of ethylenediaminetetraacetic acid (EDTA) in enhancing Cu uptake and tolerance as well as the morphological and physiological responses of Brassica napus L. seedlings under Cu stress. Four-week-old seedlings were transferred to hydroponics containing Hoagland's nutrient solution. After 2 weeks of transplanting, three levels (0, 50, and 100 μM) of Cu were applied with or without application of 2.5 mM EDTA and plants were further grown for 8 weeks in culture media. Results showed that Cu alone significantly decreased plant growth, biomass, photosynthetic pigments, and gas exchange characteristics. Cu stress also reduced the activities of antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) along with protein contents. Cu toxicity increased the concentration of reactive oxygen species (ROS) as indicated by the increased production of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in both leaves and roots. The application of EDTA significantly alleviated Cu-induced toxic effects in B. napus, showing remarkable improvement in all these parameters. EDTA amendment increased the activity of antioxidant enzymes by decreasing the concentrations of MDA and H2O2 both in leaves and roots of B. napus. Although, EDTA amendment with Cu significantly increased Cu uptake in roots, stems, and leaves in decreasing order of concentration but increased the growth, photosynthetic parameters, and antioxidant enzymes. These results showed that the application of EDTA can be a useful strategy for phytoextraction of Cu by B. napus from contaminated soils. PMID:25163559

  16. Does the acanthocephalan parasite Polymorphus minutus modify the energy reserves and antitoxic defences of its intermediate host Gammarus roeseli?

    PubMed

    Gismondi, E; Cossu-Leguille, C; Beisel, J-N

    2012-07-01

    In disturbed environments, infected organisms have to face both parasitic and chemical stresses. Although this situation is common, few studies have been devoted to the effects of infection on hosts' energy reserves and antitoxic defence capacities, while parasite survival depends on host survival. In this study, we tested the consequences of an infection by Polymorphus minutus on the energy reserves (protein, lipid and glycogen) and antioxidant defence capacities (reduced glutathione, γ-glutamylcysteine ligase activity) of Gammarus roeseli males and females, in the absence of chemical stress. Moreover, malondialdehyde concentration was used as a toxicity biomarker. The results revealed that in infected G. roeseli, whatever their gender and the sampling month, protein and lipid contents were lower, but glycogen contents were higher. This could be explained by the fact that the parasite diverts part of the host's energy for its own development. Moreover, glutathione concentrations and γ-glutamylcysteine ligase activity were both lower, which could lead to lower antitoxic defence in the host. These results suggest negative effects on individuals in the case of additional stress (e.g. pollutant exposure). In the absence of chemical stress, the lower malondialdehyde level in infected gammarids could imply a probable protective effect of the parasite. PMID:22405348

  17. Some potentialities for using aerospace information in the field of national security and defence

    NASA Astrophysics Data System (ADS)

    Getsov, Petar; Penev, Pavel

    The modern tendencies in using remote sensing techniques and systems for studying the Earth from space are formulated. The potentialities to use dual-destination space monitoring commercial satellites on the territory of the Republic of Bulgaria are outlined. General formulation of the tasks in the field of defence and security resolved through the space segment is given. A structure for a sovereign National Space Information Centre is suggested.

  18. The oxidative stress, antioxidant profile and acid-base status in preterm and term canine neonates.

    PubMed

    Vannucchi, C I; Kishi, D; Regazzi, F M; Silva, L C G; Veiga, G A L; Angrimani, D S R; Lucio, C F; Nichi, M

    2015-04-01

    During the initiation of neonatal pulmonary respiration, there is an exponential increase in reactive oxygen species that must be scavenged by antioxidant defences. However, neonate and preterm newborns are known to possess immature antioxidant mechanisms to neutralize these toxic effects. The purposes of this study were to compare the development of antioxidant system between preterm and term canine neonates and to evaluate the magnitude of acid-base balance during the initial 4 h of life. A prospective study was conducted involving 18 neonatal puppies assigned to Term Group (63 days of gestation; n = 5), Preterm-57 Group (57 days of gestation; n = 8) and Preterm-55 Group (55 days of gestation; n = 5). Neonates were physically examined through Apgar score and venous haemogasometry within 5 min, 2 and 4 h after birth. No difference on amniotic fluid and serum superoxide dismutase (SOD), glutathione peroxidase (GPx) and the marker of oxidative stress (thiobarbituric acid reactive substances; TBARS) was verified. Irrespective of prematurity, all neonates presented low vitality, hypothermia, acidosis, hypoxaemia and hypercapnia at birth. However, term puppies clinically evolved more rapidly than preterm newborns. During the course of the study, premature neonates presented more severe complications, such as prolonged hypoxaemia and even death. In conclusion, premature puppies have no signs of immature enzymatic mechanisms for controlling oxidative stress, although SOD and GPx may participate in achieving acid-base balance. Aside from initial unremarkable symptoms, premature puppies should be carefully followed up, as they are at high risk of succumbing to odds of prematurity. PMID:25611795

  19. Antioxidant effect of propolis against exposure to chromium in Cyprinus carpio.

    PubMed

    Yonar, M Enis; Yonar, Serpil Mişe; Çoban, M Zülfü; Eroğlu, Mücahit

    2014-02-01

    The aim of the present study was to investigate the ameliorative properties of propolis against the toxic effects of chromium (VI) by examining oxidative damage markers such as lipid peroxidation and the antioxidant defence system components in carp (Cyprinus carpio). The fish were exposed to sublethal concentrations of chromium. Propolis was simultaneously administered to chromium-exposed fish. Treatment was continued for 28 days, and at the end of this period, blood and tissue (liver, kidney, spleen, and gill) samples were collected. Levels of malondialdehyde (MDA) and reduced glutathione (GSH) as well as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were determined in blood and tissues for measurement of oxidant-antioxidant status. The levels of MDA, as an index of lipid peroxidation, increased in blood and tissues. Antioxidant enzyme activities in blood and tissues were modified in chromium groups compared to controls. Simultaneous administration of propolis ameliorated these parameters. The present results suggest that administration of propolis might alleviate chromium-induced oxidative stress. PMID:22052654

  20. Antioxidant enzymes expression and activity in liver of stressed wistar rat

    NASA Astrophysics Data System (ADS)

    Djordjević, J.; Nićiforović, A.; Radojčić, M. B.

    2009-09-01

    Altered activities of antioxidant defence system enzymes and the levels of free radicals scavengers have been found to correlate with various physiological or pathological conditions, including stress. The aim of this study was to determine the effects of chronic 21 day isolation stress on antioxidant enzymes (AOEs) expression and activity in Wistar rat liver tissue. The serum corticosterone (CORT) and glucose (GLU) levels were also measured, as one of the most important indicators of stress. Our data revealed that in chronic stress conditions, when both CORT and GLU were low, the AOEs expression was markedly induced. This increase in MnSOD, CuZnSOD, and catalase exhibited similar trend implying efficient detoxification of O_2^{ - .} and H2O2. However, this trend was not followed by the respective enzyme activity. While the total SOD activity was induced by the stress, catalase activity remained unaltered. This discrepancy led us to a conclusion that chronic isolation stress may cause oxidant-antioxidant imbalance in rat liver tissue, favoring H2O2 accumulation.

  1. Antioxidant status and oxidative stress in professional rugby players: evolution throughout a season.

    PubMed

    Finaud, J; Scislowski, V; Lac, G; Durand, D; Vidalin, H; Robert, A; Filaire, E

    2006-02-01

    Physical training is known to increase the antioxidant defence system and reduce exercise-induced oxidative stress. However, intense physical aerobic and anaerobic training and competition such as those imposed on professional rugby players, can induce an increase of oxidative stress which can be implicated with the arrival of overtraining. The aim of this study was to test the effect of training and competition load on oxidative stress, antioxidant status, haematological, and cell damage markers in high-level rugby players during a competitive season. Blood samples were collected four times in one year. Oxidative stress (Rmax), antioxidant (vitamin E, uric acid, TAC, and lag phase), haematological (neutrophils and monocytes) and biochemical (CK and myoglobin) parameters, as well as training and competition load, and competition results were measured. Intense periods of training and competition (T1 and T4) induced a significant higher maximum rate of conjugated dienes oxidation (+67.2% in T1 and +40.6% in T4) compared to those observed at the reference time (T3). Those periods also induced an increase in uric acid (+6.9% and 3.2%), and inflammatory markers such as monocytes (+13.3% and 10.7%). On the other hand, vitamin E (-8.7% in T1) and lag phase (-23.0% and -14.7%) were lower during these periods showing a possible training-induced antioxidant down-regulation. The less intense period of training (T2) was accompanied by lower neutrophils (-8.5%), CK (-53.7%), and myoglobin (-16.2%) values. The results suggest that oxidative stress and antioxidant measurement are significant in the biological follow-up of athletes. PMID:16475052

  2. Selenium homeostasis and antioxidant selenoproteins in brain: implications for disorders in the central nervous system.

    PubMed

    Steinbrenner, Holger; Sies, Helmut

    2013-08-15

    The essential trace element selenium, as selenocysteine, is incorporated into antioxidant selenoproteins such as glutathione peroxidases (GPx), thioredoxin reductases (TrxR) and selenoprotein P (Sepp1). Although comparatively low in selenium content, the brain exhibits high priority for selenium supply and retention under conditions of dietary selenium deficiency. Liver-derived Sepp1 is the major transport protein in plasma to supply the brain with selenium, serving as a "survival factor" for neurons in culture. Sepp1 expression has also been detected within the brain. Presumably, astrocytes secrete Sepp1, which is subsequently taken up by neurons via the apolipoprotein E receptor 2 (ApoER2). Knock-out of Sepp1 or ApoER2 as well as neuron-specific ablation of selenoprotein biosynthesis results in neurological dysfunction in mice. Astrocytes, generally less vulnerable to oxidative stress than neurons, are capable of up-regulating the expression of antioxidant selenoproteins upon brain injury. Occurrence of neurological disorders has been reported occasionally in patients with inadequate nutritional selenium supply or a mutation in the gene encoding selenocysteine synthase, one of the enzymes involved in selenoprotein biosynthesis. In three large trials carried out among elderly persons, a low selenium status was associated with faster decline in cognitive functions and poor performance in tests assessing coordination and motor speed. Future research is required to better understand the role of selenium and selenoproteins in brain diseases including hepatic encephalopathy. PMID:23500141

  3. Direct and indirect effects of kisspeptin on liver oxidant and antioxidant systems in young male rats.

    PubMed

    Aydin, M; Oktar, S; Yonden, Z; Ozturk, O H; Yilmaz, B

    2010-06-01

    Kisspeptin is a recently discovered hypothalamic peptide which plays an important role in the central control of reproductive functions. We have investigated direct and indirect effects of kisspeptin on the liver oxidative stress in young male rats. Twenty-four rats were divided into four groups (n = 6/group). First group served as control and received saline. Kisspeptin-10 was administered to the animals in the second group (20 nmol/rat/day), for a period of 7 days. Rats were given only one dose gosereline (0.9 mg/rat), a GnRH agonist in the third group. The last group received kisspeptin-10 with gosereline. The activities of catalase, superoxide dismutase (SOD), xanthine oxidase (XO), adenosine deaminase (AD) and level of malondialdehyde were studied in liver tissue. Serum samples were separated for total antioxidant capacity (TAC), total oxidant status (TOS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, blood urea nitrogen (BUN), colesterol, high-density lipoprotein (HDL) and triglyceride. Kisspeptin increased the activities of SOD and catalase (p < 0.05). When compared to the control group, the levels of malondialdehyde, TOS and AST were lower, but levels of BUN, cholesterole, HDL and AD were higher in the other three groups (p < 0.05). In conclusion, our findings suggest that kisspeptin may have antioxidant and thus protective effects on the liver tissue. PMID:20517893

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

    PubMed

    Diwan, Hema; Ahmad, Altaf; Iqbal, Muhammad

    2010-02-01

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

  5. Optimal binary solvent extraction system for phenolic antioxidants from mengkudu (Morinda citrifolia) fruit.

    PubMed

    Thoo, Yin Yin; Ho, Swee Kheng; Abas, Faridah; Lai, Oi Ming; Ho, Chun Wai; Tan, Chin Ping

    2013-01-01

    Antioxidants have been widely used in the food industry to enhance product quality by preventing oxidation of susceptible substances. This work was carried out to maximise the recovery of total phenolic content (TPC), total flavonoid content (TFC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity from Morinda citrifolia fruit via modification of the ethanol concentration, extraction time and extraction temperature at minimal processing cost. The optimised conditions yielded values of 881.57 ± 17.74 mg GAE/100 g DW for TPC, 552.53 ± 34.16 mg CE/100 g DW for TFC, 799.20 ± 2.97 µmol TEAC/100 g DW for ABTS and 2,317.01 ± 18.13 µmol TEAC/100 g DW for DPPH were 75% ethanol, 40 min of time and 57 °C. The four responses did not differ significantly (p > 0.05) from predicted values, indicating that models obtained are suitable to the optimisation of extraction conditions for phenolics from M. citrifolia. The relative amounts of flavonoids were 0.784 ± 0.01 mg quercetin/g of extract and 1.021 ± 0.04 mg rutin/g of extract. On the basis of the results obtained, M. citrifolia extract can be used as a valuable bioactive source of natural antioxidants. PMID:23771061

  6. Oxidative stress and antioxidative systems: recipes for successful data collection and interpretation.

    PubMed

    Noctor, Graham; Mhamdi, Amna; Foyer, Christine H

    2016-05-01

    Oxidative stress and reactive oxygen species (ROS) are common to many fundamental responses of plants. Enormous and ever-growing interest has focused on this research area, leading to an extensive literature that documents the tremendous progress made in recent years. As in other areas of plant biology, advances have been greatly facilitated by developments in genomics-dependent technologies and the application of interdisciplinary techniques that generate information at multiple levels. At the same time, advances in understanding ROS are fundamentally reliant on the use of biochemical and cell biology techniques that are specific to the study of oxidative stress. It is therefore timely to revisit these approaches with the aim of providing a guide to convenient methods and assisting interested researchers in avoiding potential pitfalls. Our critical overview of currently popular methodologies includes a detailed discussion of approaches used to generate oxidative stress, measurements of ROS themselves, determination of major antioxidant metabolites, assays of antioxidative enzymes and marker transcripts for oxidative stress. We consider the applicability of metabolomics, proteomics and transcriptomics approaches and discuss markers such as damage to DNA and RNA. Our discussion of current methodologies is firmly anchored to future technological developments within this popular research field. PMID:26864619

  7. Designing of Biodegradable and Biocompatible Release and Delivery Systems of Selected Antioxidants Used in Cosmetology.

    PubMed

    Maksymiak, Magdalena; Debowska, Renata; Bazela, Karolina; Dzwigalowska, Agata; Orchel, Arkadiusz; Jelonek, Katarzyna; Dolegowska, Barbara; Kowalczuk, Marek; Adamus, Grazyna

    2015-11-01

    Conjugates of antioxidants p-anisic (p-AA) and vanillic (VA) acids with nontoxic, biocompatible, and biodegradedable oligo-(R,S)-(3-hydoxybutyrate) carrier were synthesized, and their structural and biological characterization was performed. The molecular structure of the bioconjugates, in which antioxidants are covalently bonded with oligo(3-hydroxybutyrate) (OHB) chains, has been proven by mass spectrometry supported by NMR. The bioconjugate hydrolytic degradation studies allowed gaining thorough insight into the hydrolysis process and confirmed the release of p-AA and VA. In vitro studies demonstrated that all of the conjugates studied were well tolerated by KB and HaCaT cell lines, as they had no marked cytotoxicity, while conjugates with a relatively short OHB carrier are optimal to support keratinocyte function. The preliminary study of the biological activity confirmed the protective effect of VA-OHB conjugates against H2O2-induced lipid peroxidation in human keratinocytes (HaCaT). It was also demonstrated that the selected bioconjugates can penetrate all layers of the skin, which shows their functionality and opens up their potential application in cosmetology. PMID:26444385

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

    PubMed Central

    Baena-Gómez, María Auxiliadora; De La Torre Aguilar, María José; Mesa, María Dolores; Pérez Navero, Juan Luis; Gil-Campos, Mercedes

    2015-01-01

    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. PMID:26343717

  9. Imidocarb dipropionate in the treatment of Anaplasma marginale in cattle: Effects on enzymes of the antioxidant, cholinergic, and adenosinergic systems.

    PubMed

    Doyle, Rovaina L; Fritzen, Alexandro; Bottari, Nathieli B; Alves, Mariana S; da Silva, Aniélen D; Morsch, Vera M; Schetinger, Maria Rosa C; Martins, João R; Santos, Julsan S; Machado, Gustavo; da Silva, Aleksandro S

    2016-08-01

    Anaplasmosis is a worldwide hemolytic disease in cattle caused by a gram-negative obligatory intracellular bacterium, characterized by anemia and jaundice. Among the treatments used for anaplasmosis is a drug called imidocarb dipropionate, also indicated as an immunomodulator agent. However, it causes side effects associated with increased levels of acetylcholine. In view of this, the effects of imidocarb dipropionate on the purinergic system, and antioxidant enzymes in animals naturally infected by Anaplasma marginale were evaluated. Young cattle (n = 22) infected by A. marginale were divided into two groups: the Group A consisted of 11 animals used as controls; and the Group B composed of 11 animals. Imidocarb dipropionate (5 mg/kg) was used subcutaneously to treat both groups (the Group A on day 6 and the Group B on day 0). The treatment reduced acetylcholinesterase (AChE), and adenosine deaminase (ADA) activities, and increased the dismutase superoxide and catalase activities. No changes on lipid peroxidation (TBARS levels) and BChE activities were noticed. These results suggest that imidocarb dipropionate used to treat A. marginale infection in cattle has effect on antioxidant enzymes, and significantly inhibits the enzymatic activities of ADA and AChE. PMID:27301742

  10. High-intensity physical exercise disrupts implicit memory in mice: involvement of the striatal glutathione antioxidant system and intracellular signaling.

    PubMed

    Aguiar, A S; Boemer, G; Rial, D; Cordova, F M; Mancini, G; Walz, R; de Bem, A F; Latini, A; Leal, R B; Pinho, R A; Prediger, R D S

    2010-12-29

    Physical exercise is a widely accepted behavioral strategy to enhance overall health, including mental function. However, there is controversial evidence showing brain mitochondrial dysfunction, oxidative damage and decreased neurotrophin levels after high-intensity exercise, which presumably worsens cognitive performance. Here we investigated learning and memory performance dependent on different brain regions, glutathione antioxidant system, and extracellular signal-regulated protein kinase 1/2 (ERK1/2), serine/threonine protein kinase (AKT), cAMP response element binding (CREB) and dopamine- and cyclic AMP-regulated phosphoprotein (DARPP)-32 signaling in adult Swiss mice submitted to 9 weeks of high-intensity exercise. The exercise did not alter the animals' performance in the reference and working memory versions of the water maze task. On the other hand, we observed a significant impairment in the procedural memory (an implicit memory that depends on basal ganglia) accompanied by a reduced antioxidant capacity and ERK1/2 and CREB signaling in this region. In addition, we found increased striatal DARPP-32-Thr-75 phosphorylation in trained mice. These findings indicate an increased vulnerability of the striatum to high-intensity exercise associated with the disruption of implicit memory in mice and accompanied by alteration of signaling proteins involved in the plasticity of this brain structure. PMID:20888397

  11. [Effects of brassinolide on the antioxidant system and photosynthesis of cucumber seedlings under suboptimal temperature, light and salt environment].

    PubMed

    Wu, Xiu; Lu, Xiao-min

    2015-09-01

    The effects of 24-epibrassinolide (EBR) on antioxidant system and photosynthesis of cucumber seedlings were studied under suboptimal temperature, light and salt environment. Compared with the control, the leaf H2O2 content, lipid peroxidation and cell membrane permeability significantly increased, and the leaf net photosynthetic rate (Pn), stomatal conductance (g(s)), intercellular CO2 concentration (Ci), transpiration rate (Tr) and dry matter accumulation decreased by 39.3%, 40.0%, 21.2%, 47.2% and 35.9% in the suboptimal environment, respectively. Applying EBR could further improve the antioxidant enzyme activity, reduce the H2O2 content and membrane permeability of seedlings, alleviate the drop range of Pn, g(s) and Tr, improve the growth of seedlings and increase the dry matter accumulation by 25.9%. Therefore, EBR treatment could keep higher photosynthetic performance to effectively promote cucumber seedlings growth through adjusting the protective enzyme activity and reducing membrane lipid peroxide level under suboptimal temperature, light and salt environment. PMID:26785558

  12. Seasonal variation in the mixed-function oxygenase system and antioxidant enzymes of the mussel Mytilus galloprovincialis

    SciTech Connect

    Sole, M.; Porte, C.; Albaiges, J. . Dept. of Environmental Chemistry)

    1995-01-01

    Seasonal variations in the mixed-function oxygenase (MFO) system components (cytochrome P450, 418 peak, and NADPH-cytochrome c[P450] reductase) and antioxidant enzymes (catalase, superoxide dismutase [SOD], glutathione peroxidase [GPX], and DT-diaphorase) of the mussel Mytilus galloprovincialis have been evaluated. Its relation with contaminant body burden (PAHs, PCBs, DDTs, and lindane) as well as environmental parameters (water temperature, salinity, oxygen concentrations, and suspended matter) was determined. As a general trend, low MFO and antioxidant enzyme activities were detected in February--March, a peak in late April, and a gradual decrease with a minimum in June. This pattern was similar to tissue concentrations of PAHs, PCBs, DDTs, and lindate normalized to lipid weight. Cytochrome P450 content, however, exhibited a steady decrease from February to June. The observed seasonal variations are presumably related to the metabolic status of the animal, itself dependent on such factors as gonadal ripening, food availability, and the hydrological cycle, which regulates productivity in the area.

  13. Differential responses to salinity of two Atriplex halimus populations in relation to organic solutes and antioxidant systems involving thiol reductases.

    PubMed

    Bouchenak, Fatima; Henri, Patricia; Benrebiha, Fatma-Zohra; Rey, Pascal

    2012-10-15

    Atriplex halimus L. is a xero-halophyte species widespread in the Mediterranean basin. The tolerance to water stress and high salinity of two Atriplex populations from semi-arid (Djelfa) and arid saline (Laghouat) Algerian regions has been investigated in relation with organic solutes and antioxidant systems. Whereas no noticeable difference was observed between the two populations under water stress resulting from withholding watering or PEG treatment, Laghouat plants display significantly higher fresh and dry weights than Djelfa plants when exposed to high salinity. At 300mM NaCl, Laghouat plants exhibit higher concentrations in Na(+), proline and quaternary ammonium compounds, and a higher catalase activity than Djelfa plants. We then analysed the involvement of recently characterized plastidial thiol reductases, peroxiredoxins (Prxs) and methionine sulphoxide reductases (MSRs), key enzymes scavenging organic peroxides and repairing oxidized proteins, respectively. Upon salt treatment (300mM NaCl), we observed higher amounts of PrxQ and over-oxidized 2-Cys Prx in Laghouat than in Djelfa. An increased abundance of plastidial MSRA and a higher total MSR activity were also noticed in Laghouat plants treated with 300mM NaCl compared to Djelfa ones. We propose that mechanisms based on organic solutes and antioxidant enzymes like catalases, peroxiredoxins and MSRs party underlie the better tolerance of the Laghouat population to high salt. PMID:22840322

  14. Cecropin A-induced apoptosis is regulated by ion balance and glutathione antioxidant system in Candida albicans.

    PubMed

    Yun, JiEun; Lee, Dong Gun

    2016-08-01

    Cecropin A, isolated from the giant silk moth Hyalophora cecropia, is a 37-mer peptide that exerts potent antimicrobial effects. We investigated cecropin A-induced apoptosis associated with ion balance and redox state of Candida albicans. The antifungal effect of cecropin A, associated with ion movement was verified by significant increase of cell viability following pretreatment of ion channel blockers. Cecropin A induced undesired ion movement such as calcium accumulation and potassium leakage. Furthermore, the reduction of phosphatidylserine (PS) externalization was detected following pretreatment of ion channel blockers. Based on these results, we confirmed that ion imbalance regulates the apoptotic activity of cecropin A. Moreover, cecropin A decreased NADPH and glutathione levels, which are crucial factors in the intracellular antioxidant defense system. The decreased intracellular antioxidant capacity induced oxidative stress by generating reactive oxygen species (ROS). Moreover, several apoptotic features such as mitochondrial depolarization, caspase activation, and DNA fragmentation were observed in cecropin A-treated cells. In conclusion, disrupted ion balance and intracellular glutathione redox state play a key role in cecropin A-induced apoptosis in C. albicans. © 2016 IUBMB Life, 68(8):652-662, 2016. PMID:27338801

  15. Extremely high boron tolerance in Puccinellia distans (Jacq.) Parl. related to root boron exclusion and a well-regulated antioxidant system.

    PubMed

    Hamurcu, Mehmet; Hakki, Erdogan E; Demiral Sert, Tijen; Özdemir, Canan; Minareci, Ersin; Avsaroglu, Zuhal Z; Gezgin, Sait; Ali Kayis, Seyit; Bell, Richard W

    2016-01-01

    Recent studies indicate an extremely high level of tolerance to boron (B) toxicity in Puccinellia distans (Jacq.) Parl. but the mechanistic basis is not known. Puccinellia distans was exposed to B concentrations of up to 1000 mg B L-1 and root B uptake, growth parameters, B and N contents, H2O2 accumulation and ·OH-scavenging activity were measured. Antioxidant enzyme activities including superoxide dismutase (SOD), ascorbate peroxidase, catalase, peroxidase and glutathione reductase, and lipid peroxidation products were determined. B appears to be actively excluded from roots. Excess B supply caused structural deformations in roots and leaves, H2O2 accumulation and simultaneous up-regulation of the antioxidative system, which prevented lipid peroxidation even at the highest B concentrations. Thus, P. distans has an efficient root B-exclusion capability and, in addition, B tolerance in shoots is achieved by a well-regulated antioxidant defense system. PMID:27356235

  16. Beneficial effects of Murraya koenigii leaves on antioxidant defense system and ultra structural changes of pancreatic beta-cells in experimental diabetes in rats.

    PubMed

    Arulselvan, Palanisamy; Subramanian, Sorimuthu Pillai

    2007-01-30

    Oxidative stress and oxidative damage to tissues are common end points of chronic diseases such as atherosclerosis, diabetes, and rheumatoid arthritis. Oxidative stress in diabetes coexists with a reduction in the antioxidant status, which can further increase the deleterious effects of free radicals. The aim of the present study was to evaluate the possible protective effects of Murraya koenigii leaves extract against beta-cell damage and antioxidant defense systems of plasma and pancreas in streptozotocin induced diabetes in rats. The levels of glucose and glycosylated hemoglobin in blood and insulin, Vitamin C, Vitamin E, ceruloplasmin, reduced glutathione and TBARS were estimated in plasma of control and experimental groups of rats. To assess the changes in the cellular antioxidant defense system such as the level of reduced glutathione and activities of superoxide dismutase, catalase and glutathione peroxidase were assayed in pancreatic tissue homogenate. The levels of glucose, glycosylated hemoglobin, insulin, TBARS, enzymatic and non-enzymatic antioxidants were altered in diabetic rats. These alterations were reverted back to near control levels after the treatment of M. koenigii leaves extract. Transmission electron microscopic studies also revealed the protective nature of M. koenigii leaves on pancreatic beta-cells. These findings suggest that M. koenigii treatment exerts a therapeutic protective nature in diabetes by decreasing oxidative stress and pancreatic beta-cell damage. The antioxidant effect of the M. koenigii extract was compared with glibenclamide, a well-known hypoglycemic drug. PMID:17188670

  17. A serpin mutant links Toll activation to melanization in the host defence of Drosophila

    PubMed Central

    Ligoxygakis, Petros; Pelte, Nadège; Ji, Chuanyi; Leclerc, Vincent; Duvic, Bernard; Belvin, Marcia; Jiang, Haobo; Hoffmann, Jules A.; Reichhart, Jean-Marc

    2002-01-01

    A prominent response during the Drosophila host defence is the induction of proteolytic cascades, some of which lead to localized melanization of pathogen surfaces, while others activate one of the major players in the systemic antimicrobial response, the Toll pathway. Despite the fact that gain-of-function mutations in the Toll receptor gene result in melanization, a clear link between Toll activation and the melanization reaction has not been firmly established. Here, we present evidence for the coordination of hemolymph-borne melanization with activation of the Toll pathway in the Drosophila host defence. The melanization reaction requires Toll pathway activation and depends on the removal of the Drosophila serine protease inhibitor Serpin27A. Flies deficient for this serpin exhibit spontaneous melanization in larvae and adults. Microbial challenge induces its removal from the hemolymph through Toll-dependent transcription of an acute phase immune reaction component. PMID:12456640

  18. Crosstalk between liver antioxidant and the endocannabinoid systems after chronic administration of the FAAH inhibitor, URB597, to hypertensive rats.

    PubMed

    Biernacki, Michał; Łuczaj, Wojciech; Gęgotek, Agnieszka; Toczek, Marek; Bielawska, Katarzyna; Skrzydlewska, Elżbieta

    2016-06-15

    Hypertension is accompanied by perturbations to the endocannabinoid and antioxidant systems. Thus, potential pharmacological treatments for hypertension should be examined as modulators of these two metabolic systems. The aim of this study was to evaluate the effects of chronic administration of the fatty acid amide hydrolase (FAAH) inhibitor [3-(3-carbamoylphenyl)phenyl]N-cyclohexylcarbamate (URB597) on the endocannabinoid system and on the redox balance in the livers of DOCA-salt hypertensive rats. Hypertension caused an increase in the levels of endocannabinoids [anandamide (AEA), 2-arachidonoyl-glycerol (2-AG) and N-arachidonoyl-dopamine (NADA)] and CB1 receptor and the activities of FAAH and monoacylglycerol lipase (MAGL). These effects were accompanied by an increase in the level of reactive oxygen species (ROS), a decrease in antioxidant activity/level, enhanced expression of transcription factor Nrf2 and changes to Nrf2 activators and inhibitors. Moreover, significant increases in lipid, DNA and protein oxidative modifications, which led to enhanced levels of proapoptotic caspases, were also observed. URB597 administration to the hypertensive rats resulted in additional increases in the levels of AEA, NADA and the CB1 receptor, as well as decreases in vitamin E and C levels, glutathione peroxidase and glutathione reductase activities and Nrf2 expression. Thus, after URB597 administration, oxidative modifications of cellular components were increased, while the inflammatory response was reduced. This study revealed that chronic treatment of hypertensive rats with URB597 disrupts the endocannabinoid system, which causes an imbalance in redox status. This imbalance increases the levels of electrophilic lipid peroxidation products, which later participate in metabolic disturbances in liver homeostasis. PMID:27086176

  19. The antioxidative response system in Glycine max (L.) Merr. exposed to Deltamethrin, a synthetic pyrethroid insecticide.

    PubMed

    Bashir, Fozia; Mahmooduzzafar; Siddiqi, T O; Iqbal, Muhammad

    2007-05-01

    Forty-five-day-old plants of Glycine max (soybean) were exposed to several Deltamethrin (synthetic pyrethroid insecticide) concentrations (0.00%, 0.05%, 0.10%, 0.15% and 0.20%) through foliar spray in the field conditions. In the treated plants, as observed at the pre-flowering (10 DAT), flowering (45 DAT) and post-flowering (70 DAT) stages, lipid peroxidation, proline content and total glutathione content increased, whereas the total ascorbate content decreased, as compared with the control. Among the enzymatic antioxidants, activity of superoxide dismutase, ascorbate peroxidase and glutathione reductase increased significantly whereas that of catalase declined markedly in relation to increasing concentration of Deltamethrin applied. The changes observed were dose-dependent, showing a strong correlation with the degree of treatment. PMID:17055627

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

    NASA Astrophysics Data System (ADS)

    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 (p<0.05). This process of metabolic suppression was followed by a significant increase in Hsp70/Hsc70 expression (p<0.05), which may be interpreted as a strategy to prevent post-hypoxic oxidative damage during the squid's night upwards migration to the surface ocean. On the other hand, in normoxia, the higher SOD and CAT activities seemed to be a strategy to cope with the reoxygenation process, and may constitute an integrated stress response at shallower depths. GST activity and MDA concentrations did not change significantly from normoxia to hypoxia (p>0.05), with the latter indicating no enhancement of lipid peroxidation (i.e. cellular damage) at the warmer and normoxic surface waters. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how this species is quickly responding to the impacts of environmental stressors coupled with global climate change.

  1. Gastrointestinal host defence: importance of gut closure in control of macromolecular transport.

    PubMed

    Walker, W A

    An important adaptation of the gastrointestinal tract to the extrauterine environment is its development of a mucosal barrier against the penetration of harmful substances (bacteria, toxins and antigens) present within the intestinal lumen. At birth, the newborn infant must be prepared to deal with bacterial colonization of the gut, with formation of toxic byproducts of bacteria and viruses (enterotoxins and endotoxins) and with the ingestion of antigens (milk proteins). These potentially noxious substances if allowed to penetrate the mucosal epithelial barrier under pathological conditions can cause inflammatory and allergic reactions which may result in gastrointestinal and systemic disease states. To combat the potential danger of invasion across the mucosal barrier the infant must develop an elaborate system of defence mechanisms within the lumen and on the luminal mucosal surface which act to control and maintain the epithelium as an impermeable barrier to uptake of macromolecular antigens. These defences include a unique immunological system adapted to function in the complicated milieu of the intestine as well as other non-immunological processes such as a gastric barrier, intestinal surface secretions, peristaltic movement and natural antibacterial substances (lysozyme, bile salts) which also help to provide maximum protection for the intestinal surface. Unfortunately, during the immediate postpartum period, particularly for premature and small-for-dates infants, this elaborate local defence system is incompletely developed. As a result of the delay in the maturation of the mucosal barrier newborn infants are particularly vulnerable to pathological penetration by harmful intraluminal substances. The consequences of altered defence are susceptibility to infection and the potential for hypersensitivity reactions and for formation of immune complexes. With these reactions comes the potential for developing life-threatening diseases such as necrotizing

  2. Alternative Oxidase Pathway Optimizes Photosynthesis During Osmotic and Temperature Stress by Regulating Cellular ROS, Malate Valve and Antioxidative Systems.

    PubMed

    Dinakar, Challabathula; Vishwakarma, Abhaypratap; Raghavendra, Agepati S; Padmasree, Kollipara

    2016-01-01

    The present study reveals the importance of alternative oxidase (AOX) pathway in optimizing photosynthesis under osmotic and temperature stress conditions in the mesophyll protoplasts of Pisum sativum. The responses of photosynthesis and respiration were monitored at saturating light intensity of 1000 μmoles m(-2) s(-1) at 25°C under a range of sorbitol concentrations from 0.4 to 1.0 M to induce hyper-osmotic stress and by varying the temperature of the thermo-jacketed pre-incubation chamber from 25 to 10°C to impose sub-optimal temperature stress. Compared to controls (0.4 M sorbitol and 25°C), the mesophyll protoplasts showed remarkable decrease in NaHCO3-dependent O2 evolution (indicator of photosynthetic carbon assimilation), under both hyper-osmotic (1.0 M sorbitol) and sub-optimal temperature stress conditions (10°C), while the decrease in rates of respiratory O2 uptake were marginal. The capacity of AOX pathway increased significantly in parallel to increase in intracellular pyruvate and reactive oxygen species (ROS) levels under both hyper-osmotic stress and sub-optimal temperature stress under the background of saturating light. The ratio of redox couple (Malate/OAA) related to malate valve increased in contrast to the ratio of redox couple (GSH/GSSG) related to antioxidative system during hyper-osmotic stress. Further, the ratio of GSH/GSSG decreased in the presence of sub-optimal temperature, while the ratio of Malate/OAA showed no visible changes. Also, the redox ratios of pyridine nucleotides increased under hyper-osmotic (NADH/NAD) and sub-optimal temperature (NADPH/NADP) stresses, respectively. However, upon restriction of AOX pathway by using salicylhydroxamic acid (SHAM), the observed changes in NaHCO3-dependent O2 evolution, cellular ROS, redox ratios of Malate/OAA, NAD(P)H/NAD(P) and GSH/GSSG were further aggravated under stress conditions with concomitant modulations in NADP-MDH and antioxidant enzymes. Taken together, the results indicated

  3. Alternative Oxidase Pathway Optimizes Photosynthesis During Osmotic and Temperature Stress by Regulating Cellular ROS, Malate Valve and Antioxidative Systems

    PubMed Central

    Vishwakarma, Abhaypratap; Raghavendra, Agepati S.; Padmasree, Kollipara

    2016-01-01

    The present study reveals the importance of alternative oxidase (AOX) pathway in optimizing photosynthesis under osmotic and temperature stress conditions in the mesophyll protoplasts of Pisum sativum. The responses of photosynthesis and respiration were monitored at saturating light intensity of 1000 μmoles m–2 s–1 at 25°C under a range of sorbitol concentrations from 0.4 to 1.0 M to induce hyper-osmotic stress and by varying the temperature of the thermo-jacketed pre-incubation chamber from 25 to 10°C to impose sub-optimal temperature stress. Compared to controls (0.4 M sorbitol and 25°C), the mesophyll protoplasts showed remarkable decrease in NaHCO3-dependent O2 evolution (indicator of photosynthetic carbon assimilation), under both hyper-osmotic (1.0 M sorbitol) and sub-optimal temperature stress conditions (10°C), while the decrease in rates of respiratory O2 uptake were marginal. The capacity of AOX pathway increased significantly in parallel to increase in intracellular pyruvate and reactive oxygen species (ROS) levels under both hyper-osmotic stress and sub-optimal temperature stress under the background of saturating light. The ratio of redox couple (Malate/OAA) related to malate valve increased in contrast to the ratio of redox couple (GSH/GSSG) related to antioxidative system during hyper-osmotic stress. Further, the ratio of GSH/GSSG decreased in the presence of sub-optimal temperature, while the ratio of Malate/OAA showed no visible changes. Also, the redox ratios of pyridine nucleotides increased under hyper-osmotic (NADH/NAD) and sub-optimal temperature (NADPH/NADP) stresses, respectively. However, upon restriction of AOX pathway by using salicylhydroxamic acid (SHAM), the observed changes in NaHCO3-dependent O2 evolution, cellular ROS, redox ratios of Malate/OAA, NAD(P)H/NAD(P) and GSH/GSSG were further aggravated under stress conditions with concomitant modulations in NADP-MDH and antioxidant enzymes. Taken together, the results indicated

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

    PubMed

    Ajayan, K V; Selvaraju, M

    2012-11-15

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

  5. Stress in Phycomyces blakesleeanus by glucose starvation and acetate growth: response of the antioxidant system and reserve carbohydrates.

    PubMed

    Rúa, Javier; de Castro, Cristina; de Arriaga, Dolores; García-Armesto, María Rosario; Busto, Félix; del Valle, Pilar

    2014-01-01

    The objective of this study was to analyze the response of Phycomyces blakesleeanus to glucose starvation and acetate growth stress. At the onset of the exponential growth phase, the fungus shows a high tolerance to both stresses, being higher for the glucose starvation. In both stresses we have found higher activities of catalase and glutathione peroxidase, and a decrease of the pools of D-erythroascorbate (D-erythroascorbate+D-erythroascorbate monoglucoside) and glutathione (GSH+GSSG), while the intracellular GSH/GSSG redox balance becomes more reducing. Gallic acid was not detected under both stresses. Glycogen breakdown and the high levels of trehalose seem to be part of the stress response. Both stress, under the conditions of this study, seem to lead to a qualitatively similar response in P. blakesleeanus, with regard to the behavior of antioxidant system, the content of secondary metabolites and the role of the reserve carbohydrates. PMID:24556073

  6. Trained immunity: A smart way to enhance innate immune defence.

    PubMed

    van der Meer, Jos W M; Joosten, Leo A B; Riksen, Niels; Netea, Mihai G

    2015-11-01

    The innate arm of the immune system is generally viewed as primitive and non-specific and - in contrast to the adaptive immune arm - not to possess memory. However in plants and invertebrate animals that lack adaptive immunity, innate immunity will exhibit a prolonged enhanced functional state after adequate priming. A similar enhancement of function of the innate immunity has occasionally been described in vertebrates, including humans. Over the past few years we have studied this phenomenon in greater detail and we have coined the term 'Trained (innate) immunity' (TI). TI can be induced by a variety of stimuli, of which we have studied BCG and β-glucan in greater detail. The non-specific protective effects of BCG that have been observed in vaccination studies in the literature are probably due to TI. Monocytes and macrophages are among the main cells of the innate immune arm that can be trained. We have discovered that both BCG (via NOD2 signalling) and β-glucan (via dectin-1) induce epigenetic reprogramming, in particular stable changes in histone trimethylation at H3K4. These epigenetic changes lead to cellular activation, enhanced cytokine production and a change in the metabolic state of the cell with a shift from oxidative phosphorylation to aerobic glycolysis. TI is not only important for host defence and vaccine responses, but most probably also for diseases like atherosclerosis. Modulation of TI is a promising area for new treatments. PMID:26597205

  7. Defence and Security Research Coexistence, Coherence, and Convergence

    NASA Astrophysics Data System (ADS)

    Breant, Christian; Karock, Ulrich

    Defence and security research have coexisted at the European Union level since the inception of the European Defence Agency (EDA). The agency was established under a Joint Action of the Council of Ministers on 12 July 2004, "to support the Member States and the Council in their effort to improve European defence capabilities in the field of crisis management and to sustain the European Security and Defence Policy as it stands now and develops in the future".1 The political decision to create the EDA was taken at the Thessaloniki European Council on 19 and 20 June 2003. Heads of State or Government tasked the Council bodies to undertake the requisite actions, in the course of 2004, to create an intergovernmental agency in the field of defence capabilities development, research, acquisition and armaments. The EDA has been located in Brussels right from the start. It is an intergovernmental EU agency under the Council's authority within the single institutional framework of the Union. It performs its mission in close cooperation with its participating Member States (pMS) and the European institutional actors.

  8. Involvement of serotoninergic and adrenergic systems on the antidepressant-like effect of E. uniflora L. leaves essential oil and further analysis of its antioxidant activity.

    PubMed

    Victoria, Francine Novack; de Siqueira Brahm, Arthur; Savegnago, Lucielli; Lenardão, Eder João

    2013-06-01

    In this work we evaluated antidepressant-like effect of E. uniflora leaves EO employing the tail suspension test. The involvement of serotonergic and adrenergic systems was appraised. EO was administered by oral route (p.o.) in mice and the doses of 10 and 50mg/kg exhibited antidepressant-like action in the TST. The effect of EO (10mg/kg) was prevented by the pretreatment of mice with ketanserin (5mg/kg, intraperitoneal), prazosin (0.1mg/kg, i.p.) and yohimbine (0.1mg/kg, i.p.). In addition, further analysis of the in vitro antioxidant effect of the EO was made against lipid oxidation. The results revealed that EO has a potent antioxidant activity and therapeutic potential for the development of phytomedicines with antidepressant and antioxidant properties. PMID:23583586

  9. Cyclic lipopeptides from Bacillus subtilis activate distinct patterns of defence responses in grapevine.

    PubMed

    Farace, Giovanni; Fernandez, Olivier; Jacquens, Lucile; Coutte, François; Krier, François; Jacques, Philippe; Clément, Christophe; Barka, Essaid Ait; Jacquard, Cédric; Dorey, Stéphan

    2015-02-01

    Non-self-recognition of microorganisms partly relies on the perception of microbe-associated molecular patterns (MAMPs) and leads to the activation of an innate immune response. Bacillus subtilis produces three main families of cyclic lipopeptides (LPs), namely surfactins, iturins and fengycins. Although LPs are involved in induced systemic resistance (ISR) activation, little is known about defence responses induced by these molecules and their involvement in local resistance to fungi. Here, we showed that purified surfactin, mycosubtilin (iturin family) and plipastatin (fengycin family) are perceived by grapevine plant cells. Although surfactin and mycosubtilin stimulated grapevine innate immune responses, they differentially activated early signalling pathways and defence gene expression. By contrast, plipastatin perception by grapevine cells only resulted in early signalling activation. Gene expression analysis suggested that mycosubtilin activated salicylic acid (SA) and jasmonic acid (JA) signalling pathways, whereas surfactin mainly induced an SA-regulated response. Although mycosubtilin and plipastatin displayed direct antifungal activity, only surfactin and mycosubtilin treatments resulted in a local long-lasting enhanced tolerance to the necrotrophic fungus Botrytis cinerea in grapevine leaves. Moreover, challenge with specific strains overproducing surfactin and mycosubtilin led to a slightly enhanced stimulation of the defence response compared with the LP-non-producing strain of B. subtilis. Altogether, our results provide the first comprehensive view of the involvement of LPs from B. subtilis in grapevine plant defence and local resistance against the necrotrophic pathogen Bo. cinerea. Moreover, this work is the first to highlight the ability of mycosubtilin to trigger an immune response in plants. PMID:25040001

  10. Defence force activities in marine protected areas: environmental management of Shoalwater Bay Training Area, Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Wu, Wen; Wang, Xiaohua; Paull, David; Kesby, Julie

    2010-05-01

    Environmental management of military activities is of growing global concern by defence forces. As one of the largest landholders in Australia, the Australian Defence Force (ADF) is increasingly concerned with sustainable environmental management. This paper focuses on how the ADF is maintaining effective environmental management, especially in environmentally sensitive marine protected areas. It uses Shoalwater Bay Training Area (SWBTA) as a research example to examine environmental management strategies conducted by the ADF. SWBTA is one of the most significant Defence training areas in Australia, with a large number of single, joint and combined military exercises conducted in the area. With its maritime component contained in the Great Barrier Reef Marine Park (GBRMP), the Great Barrier Reef World Heritage Area (GBRWHA), and abutting Queensland’s State Marine Parks, it has high protection values. It is therefore vital for the ADF to adopt environmentally responsible management while they are conducting military activities. As to various tools employed to manage environmental performance, the ISO 14001 Environmental Management System (EMS) is widely used by the ADF. This paper examines military activities and marine environmental management within SWBTA, using the Talisman Saber (TS) exercise series as an example. These are extensive joint exercises conducted by the ADF and the United States defence forces. The paper outlines relevant legislative framework and environmental policies, analyses how the EMS operates in environmental management of military activities, and how military activities comply with these regulations. It discusses the implementation of the ADF EMS, including risk reduction measures, environmental awareness training, consultation and communication with stakeholders. A number of environmental management actions used in the TS exercises are presented to demonstrate the EMS application. Our investigations to this point indicate that the ADF is

  11. Response and adaptation of photosynthesis, respiration, and antioxidant systems to elevated CO2 with environmental stress in plants.

    PubMed

    Xu, Zhenzhu; Jiang, Yanling; Zhou, Guangsheng

    2015-01-01

    It is well known that plant photosynthesis and respiration are two fundamental and crucial physiological processes, while the critical role of the antioxidant system in response to abiotic factors is still a focus point for investigating physiological stress. Although one key metabolic process and its response to climatic change have already been reported and reviewed, an integrative review, including several biological processes at multiple scales, has not been well reported. The current review will present a synthesis focusing on the underlying mechanisms in the responses to elevated CO2 at multiple scales, including molecular, cellular, biochemical, physiological, and individual aspects, particularly, for these biological processes under elevated CO2 with other key abiotic stresses, such as heat, drought, and ozone pollution, as well as nitrogen limitation. The present comprehensive review may add timely and substantial information about the topic in recent studies, while it presents what has been well established in previous reviews. First, an outline of the critical biological processes, and an overview of their roles in environmental regulation, is presented. Second, the research advances with regard to the individual subtopics are reviewed, including the response and adaptation of the photosynthetic capacity, respiration, and antioxidant system to CO2 enrichment alone, and its combination with other climatic change factors. Finally, the potential applications for plant responses at various levels to climate change are discussed. The above issue is currently of crucial concern worldwide, and this review may help in a better understanding of how plants deal with elevated CO2 using other mainstream abiotic factors, including molecular, cellular, biochemical, physiological, and whole individual processes, and the better management of the ecological environment, climate change, and sustainable development. PMID:26442017

  12. Response and adaptation of photosynthesis, respiration, and antioxidant systems to elevated CO2 with environmental stress in plants

    PubMed Central

    Xu, Zhenzhu; Jiang, Yanling; Zhou, Guangsheng

    2015-01-01

    It is well known that plant photosynthesis and respiration are two fundamental and crucial physiological processes, while the critical role of the antioxidant system in response to abiotic factors is still a focus point for investigating physiological stress. Although one key metabolic process and its response to climatic change have already been reported and reviewed, an integrative review, including several biological processes at multiple scales, has not been well reported. The current review will present a synthesis focusing on the underlying mechanisms in the responses to elevated CO2 at multiple scales, including molecular, cellular, biochemical, physiological, and individual aspects, particularly, for these biological processes under elevated CO2 with other key abiotic stresses, such as heat, drought, and ozone pollution, as well as nitrogen limitation. The present comprehensive review may add timely and substantial information about the topic in recent studies, while it presents what has been well established in previous reviews. First, an outline of the critical biological processes, and an overview of their roles in environmental regulation, is presented. Second, the research advances with regard to the individual subtopics are reviewed, including the response and adaptation of the photosynthetic capacity, respiration, and antioxidant system to CO2 enrichment alone, and its combination with other climatic change factors. Finally, the potential applications for plant responses at various levels to climate change are discussed. The above issue is currently of crucial concern worldwide, and this review may help in a better understanding of how plants deal with elevated CO2 using other mainstream abiotic factors, including molecular, cellular, biochemical, physiological, and whole individual processes, and the better management of the ecological environment, climate change, and sustainable development. PMID:26442017

  13. Chemical Diversity and Defence Metabolism: How Plants Cope with Pathogens and Ozone Pollution

    PubMed Central

    Iriti, Marcello; Faoro, Franco

    2009-01-01

    Chemical defences represent a main trait of the plant innate immune system. Besides regulating the relationship between plants and their ecosystems, phytochemicals are involved both in resistance against pathogens and in tolerance towards abiotic stresses, such as atmospheric pollution. Plant defence metabolites arise from the main secondary metabolic routes, the phenylpropanoid, the isoprenoid and the alkaloid pathways. In plants, antibiotic compounds can be both preformed (phytoanticipins) and inducible (phytoalexins), the former including saponins, cyanogenic glycosides and glucosinolates. Chronic exposure to tropospheric ozone (O3) stimulates the carbon fluxes from the primary to the secondary metabolic pathways to a great extent, inducing a shift of the available resources in favour of the synthesis of secondary products. In some cases, the plant defence responses against pathogens and environmental pollutants may overlap, leading to the unspecific synthesis of similar molecules, such as phenylpropanoids. Exposure to ozone can also modify the pattern of biogenic volatile organic compounds (BVOC), emitted from plant in response to herbivore feeding, thus altering the tritrophic interaction among plant, phytophagy and their natural enemies. Finally, the synthesis of ethylene and polyamines can be regulated by ozone at level of S-adenosylmethionine (SAM), the biosynthetic precursor of both classes of hormones, which can, therefore, mutually inhibit their own biosynthesis with consequence on plant phenotype. PMID:20111684

  14. HVEM signalling at mucosal barriers provides host defence against pathogenic bacteria.

    PubMed

    Shui, Jr-Wen; Larange, Alexandre; Kim, Gisen; Vela, Jose Luis; Zahner, Sonja; Cheroutre, Hilde; Kronenberg, Mitchell

    2012-08-01

    The herpes virus entry mediator (HVEM), a member of the tumour-necrosis factor receptor family, has diverse functions, augmenting or inhibiting the immune response. HVEM was recently reported as a colitis risk locus in patients, and in a mouse model of colitis we demonstrated an anti-inflammatory role for HVEM, but its mechanism of action in the mucosal immune system was unknown. Here we report an important role for epithelial HVEM in innate mucosal defence against pathogenic bacteria. HVEM enhances immune responses by NF-κB-inducing kinase-dependent Stat3 activation, which promotes the epithelial expression of genes important for immunity. During intestinal Citrobacter rodentium infection, a mouse model for enteropathogenic Escherichia coli infection, Hvem−/− mice showed decreased Stat3 activation, impaired responses in the colon, higher bacterial burdens and increased mortality. We identified the immunoglobulin superfamily molecule CD160 (refs 7 and 8), expressed predominantly by innate-like intraepithelial lymphocytes, as the ligand engaging epithelial HVEM for host protection. Likewise, in pulmonary Streptococcus pneumoniae infection, HVEM is also required for host defence. Our results pinpoint HVEM as an important orchestrator of mucosal immunity, integrating signals from innate lymphocytes to induce optimal epithelial Stat3 activation, which indicates that targeting HVEM with agonists could improve host defence. PMID:22801499

  15. Environmental performance policy indicators for the public sector: the case of the defence sector.

    PubMed

    Ramos, Tomás B; Alves, Inês; Subtil, Rui; Joanaz de Melo, João

    2007-03-01

    The development of environmental performance policy indicators for public services, and in particular for the defence sector, is an emerging issue. Despite a number of recent initiatives there has been little work done in this area, since the other sectors usually focused on are agriculture, transport, industry, tourism and energy. This type of tool can be an important component for environmental performance evaluation at policy level, when integrated in the general performance assessment system of public missions and activities. The main objective of this research was to develop environmental performance policy indicators for the public sector, specifically applied to the defence sector. Previous research included an assessment of the environmental profile, through the evaluation of how environmental management practices have been adopted in this sector and an assessment of environmental aspects and impacts. This paper builds upon that previous research, developing an indicator framework--SEPI--supported by the selection and construction of environmental performance indicators. Another aim is to discuss how the current environmental indicator framework can be integrated into overall performance management. The Portuguese defence sector is presented and the usefulness of this methodology demonstrated. Feasibility and relevancy criteria are applied to evaluate the set of indicators proposed, allowing indicators to be scored and indicators for the policy level to be obtained. PMID:16580128

  16. A new cyanogenic metabolite in Arabidopsis required for inducible pathogen defence.

    PubMed

    Rajniak, Jakub; Barco, Brenden; Clay, Nicole K; Sattely, Elizabeth S

    2015-09-17

    Thousands of putative biosynthetic genes in Arabidopsis thaliana have no known function, which suggests that there are numerous molecules contributing to plant fitness that have not yet been discovered. Prime among these uncharacterized genes are cytochromes P450 upregulated in response to pathogens. Here we start with a single pathogen-induced P450 (ref. 5), CYP82C2, and use a combination of untargeted metabolomics and coexpression analysis to uncover the complete biosynthetic pathway to 4-hydroxyindole-3-carbonyl nitrile (4-OH-ICN), a previously unknown Arabidopsis metabolite. This metabolite harbours cyanogenic functionality that is unprecedented in plants and exceedingly rare in nature; furthermore, the aryl cyanohydrin intermediate in the 4-OH-ICN pathway reveals a latent capacity for cyanogenic glucoside biosynthesis in Arabidopsis. By expressing 4-OH-ICN biosynthetic enzymes in Saccharomyces cerevisiae and Nicotiana benthamiana, we reconstitute the complete pathway in vitro and in vivo and validate the functions of its enzymes. Arabidopsis 4-OH-ICN pathway mutants show increased susceptibility to the bacterial pathogen Pseudomonas syringae, consistent with a role in inducible pathogen defence. Arabidopsis has been the pre-eminent model system for studying the role of small molecules in plant innate immunity; our results uncover a new branch of indole metabolism distinct from the canonical camalexin pathway, and support a role for this pathway in the Arabidopsis defence response. These results establish a more complete framework for understanding how the model plant Arabidopsis uses small molecules in pathogen defence. PMID:26352477

  17. Action of adenosine receptor antagonists on the cardiovascular response to defence area stimulation in the rat.

    PubMed Central

    St Lambert, J H; Dawid-Milner, M S; Silva-Carvalho, L; Spyer, K M

    1994-01-01

    1. The action of adenosine in the mediation of the cardiovascular changes associated with the defence reaction has been investigated in the rat using two A1 receptor antagonists. 2. Cumulative doses of 1,3 dipropyl-cyclopentylxanthine (DPCPX) (0.3-3 mg kg-1) and ethanol (0.03-0.25 ml) and bolus doses of DPCPX (3 mg kg-1) and 8-sulphophenyltheophylline (8-SPT) (20 mg kg-1) were given into alpha-chloralose, paralysed and artificially ventilated rats. Recordings were made of arterial blood pressure and heart rate. 3. Ethanol, the vehicle for DPCPX, failed to modify the magnitude of the defence response; however, cumulative doses of DPCPX produced a dose-dependent decrease in the HDA (hypothalamic defence area)-evoked increase in arterial blood pressure, accompanied by a similar fall in the magnitude of the evoked heart rate response. 4. The evoked rise in arterial blood pressure was reduced significantly by intravenous injection of DPCPX (3 mg kg-1) but not 8-SPT (20 mg kg-1), a purely peripherally acting adenosine antagonist. 5. These results suggest that adenosine acting at A1 receptors located in the central nervous system, is involved in the HDA-evoked pressor response. Whilst the site of action of the A1 receptors is not known, possible locations are discussed. PMID:7812606

  18. Changes in energy metabolism and antioxidant defense systems during seed germination of the weed species Ipomoea triloba L. and the responses to allelochemicals.

    PubMed

    Pergo, Erica Marusa; Ishii-Iwamoto, Emy Luiza

    2011-05-01

    The relationships between changes in energy metabolism and the antioxidant defense system in the weed species Ipomoea triloba L. during seed germination and early seedling growth were investigated. The effects of some common allelochemicals on these parameters also were studied. Respiratory activity and the activities of alcohol dehydrogenase, superoxide dismutase, catalase, guaicol peroxidase, ascorbate peroxidase, glutathione reductase, and lipoxygenase were measured. Mitochondrial oxidative phosphorylation resumed shortly after the seed imbibition period, as indicated by considerable KCN-sensitive respiratory activity in embryos of I. triloba. The occurrence of superoxide dismutase, catalase, guaicol peroxidase, and lipoxygenase activities in the embryos, along with significant KCN-insensitive respiration, suggest that production of reactive oxygen species (ROS) is initiated as soon as mitochondrial respiration is resumed. All assayed antioxidant enzymes were present in the embryos except ascorbate peroxidase, which appeared only in primary roots. The activities of antioxidant enzymes increased after completion of germination, especially in primary roots. Superoxide dismutase, catalase, and guaicol peroxidase probably were the crucial enzymes involved in the neutralization of ROS, since they had higher levels of activity compared with other enzymes, such as ascorbate peroxidase and glutathione reductase. When seeds were grown in the presence of α-pinene, coumarin, quercetin, and ferulic acid, there was an additional increase in activities of antioxidant enzymes, as well as increases in lipoxygenase activity and KCN-insensitive respiration, suggesting a further increase in ROS generation. The antioxidant defense system of I. triloba was not effective in preventing lipid peroxidation caused by α-pinene. The data indicate that during seed germination and initial growth of I. triloba, a period when antioxidant enzyme activity increases to counteract the harmful

  19. The role of the enzymatic antioxidant system in cylindrospermopsin-induced toxicity in human lymphocytes.

    PubMed

    Poniedziałek, Barbara; Rzymski, Piotr; Karczewski, Jacek

    2015-08-01

    Cylindrospermopsin (CYN) is known to induce cytotoxic effects in eukaryotic cells although the exact mechanism underlying these alterations is not fully explained. Given that CYN was previously found to decrease the proliferation of human lymphocytes through DNA damage and cell cycle arrest followed by an increase in the apoptotic rate, the present study evaluated the possible involvement of reactive oxygen species (ROS) and oxidative stress in these cytopathic responses. The status of enzymatic antioxidants: superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) as well as level of lipid peroxidation (LO) under CYN influence in human lymphocytes were also studied. It was found that CYN exposure (0.01-1.0 μg/ml) induces a concentration-dependent increase in H2O2 content within a time as short as 0.5h, reaching its maximum level after 3 and 6h. The highest H2O2 content was accompanied by a significant decrease of SOD and CAT activity and an elevated level of GPx. Moreover, CYN treatment resulted in a detectable increase in LO. We conclude that ROS and the products of LO play an essential role in CYN-induced toxicity in human lymphocytes. Our study helps to elucidate the sequence of events caused by CYN in eukaryotic cells and explain the background for previously observed cytopathic responses. PMID:25863213

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

    PubMed Central

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

    2015-01-01

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

  1. Effects of mercuric chloride on antioxidant system and DNA integrity of the crab Charybdis japonica

    NASA Astrophysics Data System (ADS)

    Zhang, Hongxia; Pan, Luqing; Miao, Jingjing; Xu, Chaoqun

    2009-12-01

    Mercury (Hg) is one of the commonly encountered heavy metals, which is widespread in inshore sediments of China. In order to investigate the toxicity of Hg on marine invertebrates, we studied the effects of the divalent mercuricion (Hg2+) (at two final concentrations of 0.0025 and 0.0050 mg L-1, prepared with HgCl2) on metallothionein (MT) content, DNA integrity (DNA strand breaks) and catalase (CAT) in the gills and hepatopancreas, antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the hemolymph, gills and hepatopancreas of the portunid crab Charybdis japonica for an experiment period up to 15 d. The results indicated that MT was significantly induced after 3 d, with a positive correlation with Hg2+ dose and time in the hepatopancreas and a negative correlation with Hg2+ dose and time in the gills. While CAT in the hemolymph was not detected, it increased in the hepatopancreas during the entire experiment; SOD and GPx in the three tissues were stimulated after 12 h, both attained peak value and then reduced during the experimental period. Meanwhile, DNA strand breaks were all induced significantly after 12 h. These results suggested the detoxification strategies against Hg2+ in three tissues of C. japonica.

  2. Antioxidant activity of Maillard reaction products (MRPs) in a lipid-rich model system.

    PubMed

    Vhangani, Lusani Norah; Van Wyk, Jessy

    2016-10-01

    Ribose-lysine (RL), ribose-glycine (RG), fructose-lysine (FL) and fructose-glycine (FG) Maillard models (whole mixture (WM) pH 4 and 9) were heated at 60, 80, 121°C for 30, 60, 120min, and dialysed into low (LMW) and high molecular weight (HMW) fractions. Reducing power (RP), DPPH and peroxyl radical scavenging (PRS) evaluated indirect antioxidant activity (AA). Direct AA in a water-in-oil emulsion was evaluated through peroxide value (PV), p-anisidine, TBARs inhibition and oxidative stability (OS). PRS and RP increased significantly with temperature and time from FLWM>HMW. With DPPH, only MRPs at 121°C exhibited higher AA than BHA. MRPs exhibited low PV, p-anisidine and inhibited the formation of TBARs. BHA showed the highest OS, with p-anisidine, PV and inhibition of TBARS similar to that of MRPs. PMID:27132854

  3. Changes in metabolites, antioxidant system, and gene expression in Microcystis aeruginosa under sodium chloride stress.

    PubMed

    Chen, Lei; Mao, Feijian; Kirumba, George Chira; Jiang, Cheng; Manefield, Mike; He, Yiliang

    2015-12-01

    Microcystis (M.) aeruginosa, one of the most common bloom-forming cyanobacteria, occurs worldwide. The Qingcaosha (QCS) Reservoir is undergoing eutrophication and faces the problem of saltwater intrusion. The aim of this study was to investigate the effects of sudden salinity changes on physiological parameters and related gene transcription in M. aeruginosa under controlled laboratory conditions. The results showed that sodium chloride (50, 200 and 500 mg L(-1) NaCl) inhibited the algal growth and decreased pigment concentrations (chlorophyll a, carotenoid and phycocyanin). Sodium chloride increased both the intracellular and extracellular microcystin contents and elevated the mcyD transcript level in M. aeruginosa. It also increased the malondialdehyde (MDA) content and caused cytomembrane damage. This damage caused the release of intracellular toxins into the culture medium. In addition, NaCl decreased the maximum electron transport rate, increased the levels of reactive oxygen species (ROS) and changed the cellular redox status. Consequently, NaCl inhibited the expression of cpcB, psbA and rbcL. Furthermore, NaCl increased the activities of superoxide dismutases (SOD), catalase (CAT), glutathione reductase (GR), and total glutathione peroxidase (GPx). The transcript levels of sod and reduced glutathione (gsh) were also increased after exposure to NaCl. Our results indicate that a sudden increase in salinity increases the production and excretion of microcystin, changes the cellular redox status, enhances the activities of antioxidant enzymes, inhibits photosynthesis, and affects transcript levels of related genes in M. aeruginosa. PMID:26232039

  4. Copper blocks quinolinic acid neurotoxicity in rats: contribution of antioxidant systems.

    PubMed

    Santamaría, Abel; Flores-Escartín, Abigail; Martínez, Juan Carlos; Osorio, Laura; Galván-Arzate, Sonia; Pedraza-Chaverrí, José; Chaverrí, José Pedraza; Maldonado, Perla D; Medina-Campos, Omar N; Jiménez-Capdeville, María E; Manjarrez, Joaquín; Ríos, Camilo

    2003-08-15

    Reactive oxygen species and oxidative stress are involved in quinolinic acid (QUIN)-induced neurotoxicity. QUIN, a N-methyl-D-aspartate receptor (NMDAr) agonist and prooxidant molecule, produces NMDAr overactivation, excitotoxic events, and direct reactive oxygen species formation. Copper is an essential metal exhibiting both modulatory effects on neuronal excitatory activity and antioxidant properties. To investigate whether this metal is able to counteract the neurotoxic and oxidative actions of QUIN, we administered copper (as CuSO(4)) intraperitoneally to rats (2.5, 5.0, 7.5, and 10.0 mg/kg) 30 min before the striatal infusion of 1 microliter of QUIN (240 nmol). A 5.0 mg/kg CuSO(4) dose significantly increased the copper content in the striatum, reduced the neurotoxicity measured both as circling behavior and striatal gamma-aminobutyric acid (GABA) depletion, and blocked the oxidative injury evaluated as striatal lipid peroxidation (LP). In addition, copper reduced the QUIN-induced decreased striatal activity of Cu,Zn-dependent superoxide dismutase, and increased the ferroxidase activity of ceruloplasmin in cerebrospinal fluid from QUIN-treated rats. However, copper also produced significant increases of plasma lactate dehydrogenase activity and mortality at the highest doses employed (7.5 and 10.0 mg/kg). These results show that at low doses, copper exerts a protective effect on in vivo QUIN neurotoxicity. PMID:12899943

  5. The immune system is limited by oxidative stress: Dietary selenium promotes optimal antioxidative status and greatest immune defense in pacu Piaractus mesopotamicus.

    PubMed

    Biller-Takahashi, Jaqueline D; Takahashi, Leonardo S; Mingatto, Fábio E; Urbinati, Elisabeth C

    2015-11-01

    Reactive oxygen species (ROS) are reactive molecules containing oxygen, that form as byproducts of aerobic metabolism, including immune system processes. Too much ROS may cause oxidative stress. In this study, we examined whether it can also limit the production of immune system compounds. To assess the relationship between antioxidant status and immunity we evaluated the effect of dietary supplementation with organic selenium, given at various levels for 10 days, on the antioxidant and immune system of the pacu fish (Piaractus mesopotamicus). Fish fed a diet containing 0.6 mg Se-yeast kg(-1) showed significant improvement in antioxidant status, as well as in hematological and immunological profiles. Specifically, they had the highest counts for catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), red blood cells, and thrombocytes; the highest leukocyte count (particularly for monocytes); and the highest serum lysozyme activity. There was also a positive correlation between GPx and lysozyme in this group of fish. These findings indicate that short-term supplementation with 0.6 mg Se-yeast kg(-1) reestablished the antioxidative status, allowing the production of innate components which can boost immunity without the risk of oxidative stress. This study shows a relationship between oxidative stress and immunity, and, from a practical perspective, shows that improving immunity and health in pacu through the administration of selenium could improve their growth performance. PMID:26370542

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

    PubMed

    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. PMID:27448955

  7. Oxaliplatin activates the Keap1/Nrf2 antioxidant system conferring protection against the cytotoxicity of anticancer drugs.

    PubMed

    Wang, Xiu Jun; Li, Yinyan; Luo, Lin; Wang, Hongyan; Chi, Zhexu; Xin, Ai; Li, Xin; Wu, Jiaguo; Tang, Xiuwen

    2014-05-01

    Oxaliplatin is an important drug in the treatment of advanced metastatic colorectal cancer. NF-E2 p45-related factor 2 (Nrf2) is a key transcription factor that controls genes encoding cytoprotective and detoxifying enzymes through antioxidant-response elements (AREs) in their regulatory regions. Here, we report that oxaliplatin is an activator of the Nrf2 signaling pathway, with upregulation of ARE-driven genes and glutathione elevation. An injection of oxaliplatin into mice enhanced the expression of glutathione transferases and antioxidant enzymes in the small and large intestines of wild-type (WT) mice but not Nrf2(-/-) mice, indicating that oxaliplatin activates Nrf2 in vivo. Oxaliplatin failed to increase Nrf2 accumulation in non-small-cell lung cancer A549 cells, which harbor a dysfunctional somatic mutation of KEAP1. However, forced expression of WT mKeap1 restored the ability of oxaliplatin to activate the transcription factor. Cys(151) in Keap1 was required for the response stimulated by oxaliplatin. In addition, dichloro(1,2-diaminocyclohexane) platinum, a metabolite of oxaliplatin, was found to have the same effect in activating the ARE-gene battery as its parent drug, whereas another metabolite, oxalate, was ineffective. Moreover, two other platinum derivatives, cisplatin and carboplatin, had no effect on the Keap1/Nrf2 system. Furthermore, activation of Nrf2 by oxaliplatin reduced the sensitivity of colon cancer cells to therapeutic drugs. Conversely, knockdown of Nrf2 by Nrf2 siRNA reduced oxaliplatin-induced chemoresistance. Our study showed that oxaliplatin exerts protection against the cytotoxicity of anticancer drugs via Nrf2, indicating an important role of Nrf2 in oxaliplatin-based chemotherapy. PMID:24556415

  8. [The ROS-generating and antioxidant systems in the liver of rats treated with prednisolone and vitamin D3].

    PubMed

    Shymans'kyĭ, I O; Khomenko, A V; Lisakovs'ka, O O; Labudzyns'kyĭ, D O; Apukhovs'ka, L I; Velykyĭ, M M

    2014-01-01

    The mechanisms of glucocorticoid-induced disturbances of liver function is currently not fully clarified. Vitamin D3 was previously shown to play an important role in the regulation of impaired oxidative metabolism and detoxification function of the liver associated with the effects of hepatotoxic compounds. The study was undertaken to define the intensity of oxidative metabolism in the rat liver and survival of hepatocytes after prolonged prednisolone administration and to assess whether vitamin D3 is capable to counter glucocorticoid-induced changes. It has been shown that prednisolone (0.5 mg per animal for 30 days) leads to 1.6-fold increase in the percentage of necrotic cells among isolated hepatocytes as compared with the control. The glucocorticoid-induced impairment of hepatocellular function was accompanied by enhanced generation of reactive oxygen species (ROS), accumulation of TBA-active products and carbonylated proteins but reduced levels of free SH-groups of low molecular weight compounds. It was demonstrated a decrease in the activities of key enzymes of antioxidant system (SOD, catalase, glutathione peroxidase), whereas the activities of pro-oxidant enzymes NAD(P)H-quinone oxidoreductase and semicarbazide-sensitive amine oxidase were shown to be increased. Vitamin D3 (and to greater extent in combination with α-tocopherol) administration (100 IU) on the background of glucocorticoid therapy caused normalizing effects on the level of ROS formation, oxidative modification of biomolecules and activity of antioxidant enzymes resulting in better survival of hepatocytes. These data suggest a potential role of vitamin D3 in the regulation of oxidative metabolism alterations related to hepatotoxic action of glucocorticoids. PMID:25816595

  9. PULMONARY ANTIOXIDANTS

    EPA Science Inventory

    One of the most vital of the cellular defenses against pollution is an 'antioxidant armanentarium' which consists of oxidant scavenging molecules such as vitamin E, glutathione, vitamin C, and uric acid as well as a number of enzymes (superoxide dismutase, semidehydroascorbate re...

  10. Chloroform-induced insanity defence confounds lawyer Lincoln.

    PubMed

    Spiegel, A D; Suskind, P B

    1997-12-01

    During an 1857 trial, the defence claimed that the accused should be absolved of wilful murder because an overdose of chloroform during surgery induced insanity. In a rare appearance as a prosecutor, Abraham Lincoln tried the case for the State of Illinois. Expert medical witnesses testified about the side effects of chloroform and chloroform-induced insanity. Significantly, Lincoln was not knowledgeable about medical jurisprudence and overlooked potential sources of evidence and expert witnesses. Defence lawyers presented an impressive array of physicians to testify about insanity, about chloroform and about the results of an overdosage during anaesthesia. Considering the state of scientific knowledge at the time, the trial was notable. PMID:11619819

  11. Supramolecular amphipathicity for probing antimicrobial propensity of host defence peptides.

    PubMed

    Ravi, Jascindra; Bella, Angelo; Correia, Ana J V; Lamarre, Baptiste; Ryadnov, Maxim G

    2015-06-28

    Host defence peptides (HDPs) are effector components of innate immunity that provide defence against pathogens. These are small-to-medium sized proteins which fold into amphipathic conformations toxic to microbial membranes. Here we explore the concept of supramolecular amphipathicity for probing antimicrobial propensity of HDPs using elementary HDP-like amphiphiles. Such amphiphiles are individually inactive, but when ordered into microscopic micellar assemblies, respond to membrane binding according to the orthogonal type of their primary structure. The study demonstrates that inducible supramolecular amphipathicity can discriminate against bacterial growth and colonisation thereby offering a physico-chemical rationale for tuneable targeting of biological membranes. PMID:25966444

  12. Cytoprotective effect of preparations from various parts of Punica granatum L. fruits in oxidatively injured mammalian cells in comparison with their antioxidant capacity in cell free systems.

    PubMed

    Sestili, Piero; Martinelli, Chiara; Ricci, Donata; Fraternale, Daniele; Bucchini, Anahi; Giamperi, Laura; Curcio, Rosanna; Piccoli, Giovanni; Stocchi, Vilberto

    2007-07-01

    Pomegranate (Punica granatum L.) juice (PJ) is being increasingly proposed as a nutritional supplement to prevent atherosclerosis in humans. This therapeutically valuable potential has been attributed to PJ antioxidant capacity which has been mostly tested by means of cell-free assays: indeed, to the best of our knowledge, no study has focused on the direct antioxidant capacity of PJ in cultured cells. Here, the antioxidant capacity in cell free-systems of preparations from various parts of pomegranate has been compared with their cytoprotective -bona fide antioxidant--activity in cultured human cells (U937 promonocytes and HUVEC endothelial cells) exposed to an array of oxidizing agents. Pomegranate derivatives were PJ, arils only juice (AJ) and aqueous rinds extract (RE). In cell-free assays--1,1-diphenyl-2-picrylhydrazyl (DPPH), chemiluminescence luminol/xanthine/xanthine oxidase and lipoxygenase assays--all the preparations displayed good antioxidant capacity, the relative potency order being RE>PJ>AJ. On the contrary, only RE was capable of preventing the deleterious effects--cytotoxicity, DNA damage and depletion of non-protein sulphydrils (NPSH) pool--caused by treatment of cells with H(2)O(2), tert-butylhydroperoxide (tB-OOH) or oxidized lipoproteins (Ox-LDL) via a mechanism which is likely to involve both direct scavenging of radical species and iron chelation. Surprisingly, AJ and PJ slightly sensitized cells to the cytotoxic effects of the three agents. Then it would appear that AJ, the major and tasty part of PJ, does not contain ellagic acid and punicalagin (i.e. the polyphenols highly represented in RE which are reputed to be responsible for the antioxidant capacity) in amounts sufficient to exert cytoprotection in oxidatively injured, living cells. Based on these results, the development and evaluation of rinds-only based derivatives for antiatherogenic preventive purposes in humans should be encouraged. PMID:17376699

  13. Induced defence responses of contrasting bread wheat genotypes under differential salt stress imposition.

    PubMed

    Singh, Archana; Bhushan, Bharat; Gaikwad, Kishor; Yadav, O P; Kumar, Suresh; Rai, R D

    2015-02-01

    Plants, being sessile in nature, have developed mechanisms to cope with high salt concentrations in the soil. In this study, the effects of NaCl (50-200 mM) on expression of high-affinity potassium transporters (HKTs), antioxidant enzymes and their isozyme profiles were investigated in two contrasting bread wheat (Triticum aestivum L.) genotypes viz., HD2329 (salt-sensitive) and Kharchia65 (salt-tolerant). Kharchia65 can successfully grow in salt affected soils, while HD2329 cannot tolerate salt stress. Differential expression studies of two HKT genes (TaHKT2;1.1 and TaHKT2;3.1) revealed their up-regulated expression (-1.5-fold) in the salt-sensitive HD2329 and down-regulated (-5-fold) inducible expression in the salt-tolerant genotype (Kharchia65). Specific activity of antioxidant enzymes, viz. superoxide dismutase (SOD), peroxidase (POX), ascorbate peroxidase (APX), catalase (CAT) and glutathione reductase (GR) was found to be higher in the salt-tolerant genotype. Isozyme profile of two (POX and GR) antioxidant enzymes showed polymorphism between salt-tolerant and salt-sensitive genotypes. A new gene TaHKT2;3.1 was also identified and its expression profile and role in salt stress tolerance in wheat was also studied. Partial sequences of the TaHKT2;1.1 and TaHKT2;3.1 genes from bread wheat were submitted to the EMBL GenBank database. Our findings indicated that defence responses to salt stress were induced differentially in contrasting bread wheat genotypes which provide evidences for functional correlation between salt stress tolerance and differential biochemical and molecular expression patterns in bread wheat. PMID:26040114

  14. Long Term Effect of Curcumin in Restoration of Tumour Suppressor p53 and Phase-II Antioxidant Enzymes via Activation of Nrf2 Signalling and Modulation of Inflammation in Prevention of Cancer

    PubMed Central

    Das, Laxmidhar; Vinayak, Manjula

    2015-01-01

    Inhibition of carcinogenesis may be a consequence of attenuation of oxidative stress via activation of antioxidant defence system, restoration and stabilization of tumour suppressor proteins along with modulation of inflammatory mediators. Previously we have delineated significant role of curcumin during its long term effect in regulation of glycolytic pathway and angiogenesis, which in turn results in prevention of cancer via modulation of stress activated genes. Present study was designed to investigate long term effect of curcumin in regulation of Nrf2 mediated phase-II antioxidant enzymes, tumour suppressor p53 and inflammation under oxidative tumour microenvironment in liver of T-cell lymphoma bearing mice. Inhibition of Nrf2 signalling observed during lymphoma progression, resulted in down regulation of phase II antioxidant enzymes, p53 as well as activation of inflammatory signals. Curcumin potentiated significant increase in Nrf2 activation. It restored activity of phase-II antioxidant enzymes like GST, GR, NQO1, and tumour suppressor p53 level. In addition, curcumin modulated inflammation via upregulation of TGF-β and reciprocal regulation of iNOS and COX2. The study suggests that during long term effect, curcumin leads to prevention of cancer by inducing phase-II antioxidant enzymes via activation of Nrf2 signalling, restoration of tumour suppressor p53 and modulation of inflammatory mediators like iNOS and COX2 in liver of lymphoma bearing mice. PMID:25860911

  15. Clinical pharmacokinetics of antioxidants and their impact on systemic oxidative stress.

    PubMed

    Schwedhelm, Edzard; Maas, Renke; Troost, Raphael; Böger, Rainer H

    2003-01-01

    Dietary antioxidants play a major role in maintaining the homeostasis of the oxidative balance. They are believed to protect humans from disease and aging. Vitamin C (ascorbic acid), vitamin E (tocopherol), beta-carotene and other micronutrients such as carotenoids, polyphenols and selenium have been evaluated as antioxidant constituents in the human diet. This article addresses data provided from clinical trials, highlighting the clinical pharmacokinetics of vitamin C, vitamin E, beta-carotene, lycopene, lutein, quercetin, rutin, catechins and selenium. The bioavailability of vitamin C is dose-dependent. Saturation of transport occurs with dosages of 200-400 mg/day. Vitamin C is not protein-bound and is eliminated with an elimination half-life (t((1/2))) of 10 hours. In Western populations plasma vitamin C concentrations range from 54-91 micro mol/L. Serum alpha- and gamma-tocopherol range from 21 micro mol/L (North America) to 27 micro mol/L (Europe) and from 3.1 micro mol/L to 1.5 micro mol/L, respectively. alpha-Tocopherol is the most abundant tocopherol in human tissue. The bioavailability of all-rac-alpha-tocopherol is estimated to be 50% of R,R,R-alpha-tocopherol. The hepatic alpha-tocopherol transfer protein (alpha-TTP) together with the tocopherol-associated proteins (TAP) are responsbile for the endogenous accumulation of natural alpha-tocopherol. Elimination of alpha-tocopherol takes several days with a t((1/2)) of 81 and 73 hours for R,R,R-alpha-tocopherol and all-rac-alpha-tocopherol, respectively. The t((1/2)) of tocotrienols is short, ranging from 3.8-4.4 hours for gamma- and alpha-tocotrienol, respectively. gamma-Tocopherol is degraded to 2, 7, 8-trimethyl-2-(beta-carboxyl)-6-hyrdoxychroman by the liver prior to renal elimination. Blood serum carotenoids in Western populations range from 0.28-0.52 micro mol/L for beta-carotene, from 0.2-0.28 for lutein, and from 0.29-0.60 for