Effect of copper excess on superoxide dismutase,catalase, and peroxidase activities in sunflower seedlings (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.)

The changes in lipid peroxidation, antioxidative and lignifying enzyme activities were studied in leaves and stems of Cu-stressed sunflower seedlings. In both organs, membrane lipid peroxidation was enhanced by copper treatment. Additionally, catalase (EC 1.11.1.6) and superoxide dismutase (EC 1.15.1.1) activities were modulated: The activity of superoxide dismutase was enhanced in both plant organs. Differently, catalase activity was not affected in leaves but significantly reduced in stems. Peroxidase (EC 1.11.1.7) activities were also changed. Guaiacol peroxidase activity was increased in leaves and stems. In the same way, electrophoretic analysis of the anionic isoperoxidases involved in lignification (syringaldazine peroxidase) revealed qualitative and quantitative changes on the isoenzyme patterns. These modifications were accompanied by the increase of the NADH-oxidase activity in ionically cell wall bound fraction. It appeared that the growth delay caused by copper excess could be related to the activation of lignifying peroxidases.     

Fungal pathogen-induced changes in the antioxidant systems of leaf peroxisomes from infected tomato plants

Peroxisomes, being one of the main organelles where reactive oxygen species (ROS) are both generated and detoxified, have been suggested to be instrumental in redox-mediated plant cell defence against oxidative stress. We studied the involvement of tomato (Lycopersicon esculentum Mill.) leaf peroxisomes in defence response to oxidative stress generated upon Botrytis cinerea Pers. infection. The peroxisomal antioxidant potential expressed as superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6) and glutathione peroxidase (GSH-Px, EC 1.11.1.19) as well as the ascorbate-glutathione (AA-GSH) cycle activities was monitored. The initial infection-induced increase in SOD, CAT and GSH-Px indicating antioxidant defence activation was followed by a progressive inhibition concomitant with disease symptom development. Likewise, the activities of AA-GSH cycle enzymes: ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1) and glutathione reductase (GR, EC 1.6.4.2) as well as ascorbate and glutathione concentrations and redox ratios were significantly decreased. However, the rate and timing of these events differed. Our results indicate that B. cinerea triggers significant changes in the peroxisomal antioxidant system leading to a collapse of the protective mechanism at advanced stage of infection. These changes appear to be partly the effect of pathogen-promoted leaf senescence.     

Desiccation-induced Changes in Antioxidant Enzymes,Fatty Acids,and Amino Acids in the Cyanobacterium <Emphasis Type="Italic">Tolypothrix scytonemoides</Emphasis>

Tolypothrix scytonemoides subjected to desiccation exhibited increased antioxidant enzyme activities when compared to fresh cells. The activities of catalase (EC 1.11.1.6) and superoxide dismutase (EC 1.15.1.1) were enhanced in desiccated cells by 42.8% and 8.1%, respectively. The isoforms of catalase and superoxide dismutase were detected by activity staining of crude samples separated on native gels. The isoforms of superoxide dismutase were identified based on their sensitivity to hydrogen peroxide and cyanide. The changes in fatty acids and amino acids in fresh and desiccated cells were also investigated and it was found that the quantity of certain fatty acids and amino acids was greater in desiccated cells. Palmitic acid, palmitoleic acid, heptadecanoic acid, linoleic acid, and myristic acid were more in desiccated cells when compared to fresh cells. Desiccated cells synthesized myristoleic acid, eicosenoic acid and behenic acid, acids which were not synthesized by the fresh cells, whereas tricosanoic acid was synthesized by the fresh cells and not by desiccated cells. The levels of lysine, serine, glycine, proline and cysteine were also comparatively greater in the desiccated cells.     

Coisolation of glutathione peroxidase, catalase and superoxide dismutase from human erythrocytes

Glutathione peroxidase (GSH-Px; glutathione: hydrogen peroxide oxidoreductase; EC 1.11.1.9), catalase (H2O2: H2O2 oxidoreductase; EC 1.11.1.6) and superoxide dismutase (superoxide: superoxide oxidoreductase; EC 1.15.1.1) were coisolated from human erythrocyte lysate by chromatography on DEAE-cellulose. Glutathione peroxidase was separated from superoxide dismutase and catalase by thiol-disulfide exchange chromatography and then purified to approximately 90% homogeneity by gel permeation chromatography and dye-ligand affinity chromatography. Catalase and superoxide dismutase were separated from each other and purified further by gel permeation chromatography. Catalase was then purified to approximately 90% homogeneity by ammonium sulfate precipitation and superoxide dismutase was purified to apparent homogeneity by hydrophobic interaction chromatography. The results for glutathione peroxidase represent an improvement of approximately 10-fold in yield and 3-fold in specific activity compared with the established method for the purification of this enzyme. The yields for superoxide dismutase and catalase were high (45 mg and 232 mg, respectively, from 820 ml of washed packed cells), and the specific activities of both enzymes were comparable to values found in the literature.     

Effects of brassinosteroids on barley root growth,antioxidant system and cell division

Homobrassinolide (HBR), which is one of the most biologically active forms of Brassinosteroids (BRs), was used to examine the potential effects of hormone on root germination, antioxidant system enzymes and cell division of barley (Hordeum vulgare L.). Seeds were germinated between filter papers in 0.1, 0.5 and 1.0 μM HBR-supplemented distilled water for 48 h at dark with their controls. HBR application increased especially the primary root growth significantly with increasing concentrations when compared with the control materials and reached two fold increase in 1.0 μM HBR treated material. Treated and untreated control group roots were fixed in 1:3 aceto-alcohol and aceto-orcein preparations were made. Roots treated with HBR showed more mitotic activity, mitotic abnormalities and significant enlargements at the root tips when compared with control material. HBR application decreased total soluble protein content, superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6) and peroxidase (EC 1.11.1.11) activities significantly at 1.0 μM HBR concentration. Data presented here is one of the first detailed analyses of HBR effect on barley root development.     

Superoxide dismutase,catalase, and glutathione peroxidase in the swim bladder of the physoclistous fish,Opsanus tau L

Summary The antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase were measured in the rete mirabile and gas gland epithelium area of the swim bladder of the toadfish Opsanus tau. When the concentration of enzyme in the swim bladder was compared with the concentration in other organs (kidney, heart, gills) of the same fish, the swim bladder was found to have the highest concentration of superoxide dismutase but relatively low levels of glutathione peroxidase and catalase.Cytochemical assay for the peroxidatic activity of catalase confirmed that virtually no catalase is present in epithelial cells of the gas gland. A similar assay for peroxidase revealed a cyanide-sensitive peroxidase in the multilamellar bodies of these cells. Most of the catalase and peroxidase in the rete mirabile appears to be confined to the granules of neutrophils and the cytoplasm of erythrocytes. Enzyme activity in the neutrophils is not inhibited by 10^-1 M KCN. Cyanide does appear to inhibit the peroxidase activity in erythrocytes but has little effect on catalase in these cells.Supported by grant No. HL23338 from the National Institutes of Health     

Manganese superoxide dismutase from a higher plant

A manganese-containing superoxide dismutase (EC 1.15.1.1) was purified to homogeneity from a higher plant for the first time. The enzyme was isolated fromPisum sativum leaf extracts by thermal fractionation, ammonium sulfate salting out, ion-exchange and gel-filtration column chromatography, and preparative polyacrylamide gel electrophoresis. Pure manganese superoxide dismutase had a specific activity of about 3,000 U mg^-1 and was purified 215-fold, with a yield of 1.2 mg enzyme per kg whole leaf. The manganese superoxide dismutase had a molecular weight of 94,000 and contained one g-atom of Mn per mol of enzyme. No iron and copper were detected. Activity reconstitution experiments with the pure enzyme ruled out the possibility of a manganese loss during the purification procedure. The stability of manganese superoxide dismutase at-20°C, 4°C, 25°C, 50°C, and 60°C was studied, and the enzyme was found more labile at high temperatures than bacterial manganese superoxide dismutases and iron superoxide dismutases from an algal and bacterial origin.Abbreviations NBT nitro blue tetrazolium - SOD superoxide dismutase (EC 1.15.1.1)     

Superoxide dismutase and catalase in Azotobacter vinelandii grown in continuous culture at different dissolved oxygen concentrations

Superoxide dismutase and catalase activities were studied in Azotobacter vinelandii grown diazotrophically at different ambient oxygen concentrations in continuous culture. Activities were expressed either as specific activity or activity per cell. Specific superoxide dismutase activity increased by a factor of 1.6 with increasing oxygen concentration from about 1% to 90% air saturation of the growth medium whereas specific catalase activity increased only slightly, if at all. Since cell volumes increased in parallel to increases in the oxygen concentration cellular superoxide dismutase activities increased by a factor of 4.3 while cellular catalase activities increased by a factor of 3.3. Under all conditions only the Fe-containing form of superoxide dismutase was detected. The possible function of these enzymes in the protection nitrogenase from oxygen damage is discussed.Abbreviation SOD superoxide dismutase     

Possible involvement of nodule superoxide dismutase and catalase in leghemoglobin protection

Superoxide anion is able to oxidize oxyleghemoglobin prepared from soybean nodules. Furthermore, ferrileghemoglobin is oxidized to leghemoglobin (IV) by hydrogen peroxide and this irreversible reaction leads to a complete inactivation of the hemoprotein. In scavenging O ₂ ^- and H₂O₂, superoxide dismutase (EC 1.15.1.1) and catalase (EC 1.11.1.6) are able to limit these oxidations. The occurrence of these enzymes within soybean nodules and their main characteristics are reported here. A general scheme taking into account their roles in leghemoglobin protection in vivo is proposed.Abbreviations Lb leghemoglobin - SOD superoxide dismutase     

Biosynthesis of superoxide dismutase and catalase inSaccharomyces cerevisiae: effects of oxygen and cytochromec deficiency

Summary Two strains ofSaccharomyces cerevisiae were used to study the synthesis of superoxide dismutase. One strain (cytochromec-deficient) contained 5–10% of the normal amounts of total cytochromec, while the other strain was a wild type. The cytochromec-deficient mutant had lower specific growth rate, growth yield, and oxygen uptake than the wild type. The superoxide dismutase and catalase activities, in both strains, were significantly lower under anaerobic than under aerobic conditions. Furthermore, under aerobic conditions the mutant contained higher levels of superoxide dismutase than the wild type which may be attributed to the higher intracellular flux of superoxide radicals caused by the cytochromec deficiency. The mutant also showed a lower level of catalase which was due to glucose repression.Paper Number 10007 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695, U.S.A. The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of the products named, nor criticism of similar ones not mentioned.     

Prevention of N-nitrosodiethylamine-induced hepatocarcinogenesis by S-allylcysteine

Chemopreventive effect of S-allylcysteine (constituent of garlic) on N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis was evaluated in Wistar rats. Significantly decreased lipid peroxidation products (thiobarbituric acid reactive substances-TBARS and lipid hydroperoxides) with increased level of reduced glutathione, increased activities of glutathione S-transferase, and glutathione peroxidase were observed in liver of NDEA-treated rats when compared with control rats. The activities of superoxide dismutase and catalase were significantly decreased in tumor tissue when compared with control. Administration of S-allylcysteine (SAC) showed the inhibition of tumor incidence, modulated the lipid peroxidation, and increased the reduced glutathione, glutathione-dependent enzymes, superoxide dismutase, and catalase in NDEA-induced carcinogenesis. From our results, we speculate that S-allylcysteine mediates its chemopreventive effects by modulating lipid peroxidation, GST stimulation, and by increasing the antioxidants. Hence SAC prevents cells from loss of oxidative capacity in NDEA-induced hepatocarcinogenesis.     

Differential response of antioxidative enzymes in embryonic axes and cotyledons of germinating lupine seeds

Germination of lupine (Lupinus luteus L.) seeds was accompanied by an increase in concentration of free radicals with g ₁ and g ₂ values of 2.0056 ± 0.0003 and 2.0033 ± 0.0005, respectively. The highest intensity of free radical signal was observed in embryo axes immediately after radicle protruded through the seed coat. Hydrogen peroxide accumulated in embryonic axes and cotyledons during imbibition before the onset of germination in the seed population. The activities of superoxide dismutase (SOD, EC 1.15.1.1) and catalase (CAT, EC 1.11.1.6) rose progressively in embryo axes. In cotyledons SOD activity did not change significantly, while that of CAT increased during germination. The enhancement of Cu, Zn-SODs and Mn-SOD isoforms in embryonic axes was observed. A new isoform of catalase was synthesized, suggesting that it plays a relevant role during germination. SOD and CAT activities were detected in dry seeds. Free radical generation and response of antioxidative enzymes differed between embryo axes and cotyledons during the germination timecourse.     

The interrelationship of superoxide dismutase and peroxidatic enzymes in the red cell.

Activities of superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) and catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase, EC 1.11.1.6) were determined during the course of incubation of red cell suspensions with 1,4-naphthoquinone-2-sulfonic acid. In the absence of glucose, incubation with napthoquinone sulfonate resulted in an inhibition of catalase and superoxide dismutase. The catalase inhibitor, 3-amino-1,2,4-triazole enhanced inactivation of catalase in the presence of naphthoquinone sulfonate and this in turn led to augmented inhibition of superoxide dismutase. The presence of glucose in the incubation medium prevented napthoquinone sulfonate-induced enzyme inhibition in the absence of aminotriazole, but had little effect in the presence of aminotriazole. The relevance of these findings to the cellular interrelationship of peroxidatic enzymes and superoxide dismutase is discussed.     

Metabolic responses of Lemna minor to lead ions II. Induction of antioxidant enzymes in roots

Duckweed Lemna minor L. was grown on Wang culture medium supplemented with lead ions for 24 hours. Metal was tested at 1.5, 3 and 6 mg·dm⁻³ concentrations. The response of antioxidant enzymes, such as superoxide dismutase, catalase and peroxidase in lead-treated roots of duckweed was investigated. Lead ions had no effect on the spectrum of catalase and peroxidase isoenzymes while a new isoform of superoxide dismutase appeared on the Pb treated roots. A lead-depended increase in activities of superoxide dismutase and peroxidase was observed, whereas catalase activity was maintained at relatively constant values at lower lead concentrations and then decreased markedly below control level.     

Oxidative variables and antioxidant enzymes activities in the mdx mouse brain

Dystrophin is a protein found at the plasmatic membrane in muscle and postsynaptic membrane of some neurons, where it plays an important role on synaptic transmission and plasticity. Its absence is associated with Duchenne's muscular dystrophy (DMD), in which cognitive impairment is found. Oxidative stress appears to be involved in the physiopathology of DMD and its cognitive dysfunction. In this regard, the present study investigated oxidative parameters (lipid and protein peroxidation) and antioxidant enzymes activities (superoxide dismutase and catalase) in prefrontal cortex, cerebellum, hippocampus, striatum and cortex tissues from male dystrophic mdx and normal C57BL10 mice. We observed (1) reduced lipid peroxidation in striatum and protein peroxidation in cerebellum and prefrontal cortex; (2) increased superoxide dismutase activity in cerebellum, prefrontal cortex, hippocampus and striatum; and (3) reduced catalase activity in striatum. It seems by our results, that the superoxide dismutase antioxidant mechanism is playing a protective role against lipid and protein peroxidation in mdx mouse brain.     

Superoxide radicals and antiradical defence of propionic acid bacteria

Superoxide dismutase activity was demonstrated for 6 strains of 3 propionibacteria species. Rather high level of superoxide dismutase activity found in propionibacteria was in accordance with high level of catalase activity reported for propionibacteria previously. Both these activities were shown to have cytozolic localization. For the first time peroxidase activity was detected in gel-fractionated crude cell extracts of propionibacteria. The ability to produce superoxide radicals in NADH-dependent oxidation system was revealed for three strains of the bacteria. The level of superoxide production by the membrane particles of the propionic acid bacteria correlated with the levels of superoxide dismutase and catalase activities and was the lowest for Propionibacterium shermanii. The ability to perform monovalent oxygen reduction during succinate oxidation was not revealed. The intact cells of P. globosum, P. vannielii, P. shermanii apparently did not excrete superoxide radicals into culture fluid during respiration.     

Antioxidant defense system in leaves of Indian mustard (<Emphasis Type="Italic">Brassica juncea</Emphasis>) and rape (<Emphasis Type="Italic">Brassica napus</Emphasis>) under cadmium stress

Plant species capable of hyper-accumulating heavy metals are of considerable interest for phytoremediation, and differ in their ability to accumulate metals from environment. Using two brassica species (Brassica juncea and Brassica napus), nutrient solution experiments were conducted to study variation in tolerance to cadmium (Cd) toxicity based on (1) lipid peroxidation and (2) changes in antioxidative defense system in leaves of both plants (i.e., superoxide dismutase (SOD EC 1.15.1.1), catalase (CAT EC 1.11.1.6), ascorbate peroxidase (APX EC 1.11.1.11), guaiacol peroxidase (GPX EC 1.11.1.7), glutathione reductase (GR EC 1.6.4.2), levels of phytochelatins (PCs), non-protein thiols (NP-SH), and glutathione. Plants were grown in nutrient solution under controlled environmental conditions, and subjected to increasing concentrations of Cd (0, 10, 25 and 50 μM) for 15 days. Results showed marked differences between both species. Brassica napus under Cd stress exhibited increased level of lipid peroxidation, as was evidenced by the increased malondialdehyde (MDA) content in leaves. However, in Brassica juncea treated plants, MDA content remained unchanged. In Brassica napus, with the exception of GPX, activity levels of some antioxidant enzymes involved in detoxification of reactive oxygen species (ROS), including SOD, CAT, GR, and APX, decreased drastically at high Cd concentrations. By contrast, in leaves of Brassica juncea treated plants, there was either only slight or no change in the activities of the antioxidative enzymes. Analysis of the profile of anionic isoenzymes of GPX revealed qualitative changes occurring during Cd exposure for both species. Moreover, levels of NP-SH and PCs, monitored as metal detoxifying responses, were much increased in leaves of Brassica juncea by increasing Cd supply, but did not change in Brassica napus. These results indicate that Brassica juncea plants possess the greater potential for Cd accumulation and tolerance than Brassica napus.     

Pro-oxidant and antioxidant processes in gas gland and other tissues of cod (Gadus morhua)

Partial reduction of molecular oxygen produces reactive oxyradicals, including the superoxide anion radical (O _- ² ) and hydroxyl radical (·OH). The gas gland functions under hyperoxic and acidic conditions and therefore is likely to be subjected to enhanced oxidative stress. Aspects of pro- and antioxidant processes in gas gland were compared with other tissues likely to be subject to differing degrees of oxyradical production, viz. liver (site of chemically-mediated oxyradical production), gills and skeletal muscle. Antioxidant enzyme activities (superoxide dismutase, catalase, selenium-dependent and total glutathione peroxidase) per g wet weight were highest in liver and lowest in muscle. Catalase and glutathione peroxidase activies per g wet weight were higher in gills than in gas gland, whereas the reverse was seen for superoxide dismutase. Cytosolic superoxide dismutase activities per mg protein were two- and nine-fold higher in gas gland than in liver and gills. The pH characteristics of the antioxidant enzymes were generally similar in all the tissues. Glutathione, vitamin E and unsaturated (peroxidizable) lipid levels were generally highest in liver followed by gas gland. Lipid peroxidation (malonaldehyde equivalents) was evident in all tissues except gas gland. Hydrogen peroxide and O _- ² were involved in the NAD(P)H-dependent ferric/EDTA-mediated formation of ·OH (as measured by 2-keto-4-methiolbutyrate oxidation) by mitochondrial and postmitochondrial fractions of gas gland. Tissue maximal potentials for ·OH production paralled superoxide dismutase but not catalase or glutathione peroxidase activities. Overall, the results confirm the presence of effective antioxidant defences in gas gland and support previous workers' contentions of a central role for superoxide dismutase in this process.Abbreviations EDTA di-sodium ethylenediaminetetra-acetic acid - G-6-P glucose-6-phosphate - GPX total glutathione peroxidase - GSH reduced glutathione - GSSG oxidised glutathione - GST glutathion-S-transferase - HPLC high performance liquid chromatography - KMBA 2-keto-4-methiolbutyric acid - MOPS 3-[N-morpholino] propane-sulphonic acid - PMS postmitochondrial supernatant - Se-GPX selenium-dependent glutathion peroxidase - SOD superoxide dismutase - TCA trichloroacetic acid