Plant defenses against oxidative stress

Many reactive oxygen species such as ozone, singlet oxygen, hydroxyl radical, and organic oxyradicals have been implicated in damage to plant organs and biopolymers such as chloroplasts, cell membranes, proteins, and DNA. The principal defenses against these reactive molecules and free radicals in plants include detoxifying enzymes (catalase, superoxide dismutase, etc.) and also lower molecular weight secondary products with antioxidant activity. These latter compounds include a great variety of phenolic compounds, carotenoids, nitrogenous, and sulfur-containing materials. Some of the more important mechanisms of action of the secondary compounds will be discussed, with emphasis on the use of structural and kinetic data to identify the most effective antioxidants against peroxy radical-induced damage, which is perhaps the most important of the oxidative stresses present in the usual environment of plants. © 1995 Wiley-Liss, Inc.     

Regulation of human neutrophil oxidative burst by pro- and anti-inflammatory cytokines

Human polymorphonuclear neutrophils play a key role in host defenses against invading microorganisms. In response to a variety of stimuli, neutrophils release large quantities of superoxide anion (O2.-) in a phenomenon known as the respiratory burst. O2.- is the precursor of potent oxidants, which are essential for bacterial killing and also potentiate inflammatory reactions. Regulation of this production is therefore critical to kill pathogens without inducing tissue injury. Neutrophil production of O2.- is dependent on the respiratory burst oxidase, or NADPH oxidase, a multicomponent enzyme system that catalyzes NADPH-dependent reduction of oxygen to O2.-. NADPH oxidase is activated and regulated by various neutrophil stimuli at infectious or inflammatory sites. Proinflammatory cytokines such as GM-CSF, TNF and IL-8 modulate NADPH oxidase activity through a priming phenomenon. These cytokines induce a very weak oxidative response by PMN but strongly enhance neutrophil release of reactive oxygen species on exposure to a secondary applied stimulus such as bacterial N-formyl peptides. Priming phenomena are involved in normal innate immune defense and in some inflammatory diseases. The mechanisms underlying the priming process are poorly understood, although some studies have suggested that priming with various agonists is regulated at the receptor and post-receptor levels. Resolution of inflammation involves desensitization phenomena and cytokines are involved in this process by various mechanisms. A better understanding of phenomena involved in the regulation of NADPH oxidase could help to develop novel therapeutic agents for inflammatory diseases involving abnormal neutrophil superoxide production.     

Antioxidant enzyme inhibitors enhance singlet oxygen-induced cell death in HL-60 cells

Singlet oxygen is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules and it also promotes deleterious processes such as cell death. The protective role of antioxidant enzymes against singlet oxygen-induced oxidative damage in HL-60 cells was investigated in control and cells pre-treated with diethyldithiocarbamic acid, aminotriazole and oxlalomalate, specific inhibitors of superoxide dismutase, catalase and NADP⁺-dependent isocitrate dehydrogenase, respectively. Upon exposure to rose bengal (20 μM)/light (15 min), which generates singlet oxygen, to HL-60 cells, the viability was lower and the lipid peroxidation and oxidative DNA damage were higher in inhibitor-treated cells as compared to control cells. We also observed the significant increase in the endogenous production of reactive oxygen species as well as the significant decrease in the intracellular GSH level in inhibitor-treated HL-60 cells exposed to singlet oxygen. Upon exposure to rose bengal (3 μM)/light (15 min), which induced apoptotic cell death, a clear inverse relationship was observed between the control and inhibitor-treated HL-60 cells in their susceptibility to apoptosis. These results suggest that antioxidant enzymes play an important role in cellular defense against singlet oxygen-induced cell death including necrosis and apoptosis.     

Oxidative stress, tissue remodeling and regression during amphibian metamorphosis

Anuran metamorphosis is characterized by rapid and drastic changes in the body form and function under the influence of thyroid hormones. We evaluated the involvement of reactive oxygen species and antioxidant defenses during intestinal remodeling and tail regression of tadpoles of Xenopus laevis. Oxidative stress resulting from depletion in catalase and reduced glutathione, and simultaneous increase in lipid peroxidation during intestinal remodeling as well as tail regression are probably responsible for cell death and differentiation in these organs. Gene expression data for superoxide dismutase and catalase supports this contention. A dramatic increase in another antioxidant, ascorbic acid content of both these organs during metamorphic climax indicates its multifactor role such as collagen synthesis in intestine and controlled tail regression. These findings suggest that the cellular environment in the intestine and tail becomes progressively more oxidizing during its remodeling and regression respectively.     

Investigation of Cadmium-Induced Genotoxicity and Oxidative Stress Response in Indian Major Carp,Labeo rohita

We investigated genotoxicity and oxidative stress in the gills of Labeo rohita exposed to 33.6, 67.1, and 100.6 mg L^–1of cadmium chloride at 96 h. Genotoxicity was assessed using single cell gel electrophoresis whereas oxidative stress was monitored through lipid peroxidation induction and antioxidant response parameters, namely reduced glutathione (GSH), glutathione peroxidase, glutathione-S-transferase, superoxide dismutase, and catalase (CAT) activities. Significant (p < .05) effect of both concentration and time of exposure was observed on the extent of DNA damage in treated fish. Similarly, malondialdehyde content, level of GSH, and activities of antioxidant enzymes were significantly elevated in treated groups, except CAT. The increased DNA damage and lipid peroxidation (LPO) content along with fluctuation in antioxidant defense system in fish indicated the interaction of cadmium (Cd) with DNA repair processes and production of reactive oxygen species. Thus, Cd is liable for induction of LPO, alteration of antioxidant defenses, and DNA damage in gills of L. rohita.     

Antioxidant enzyme inhibitors enhance singlet oxygen-induced cell death in HL-60 cells

Singlet oxygen is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules and it also promotes deleterious processes such as cell death. The protective role of antioxidant enzymes against singlet oxygen-induced oxidative damage in HL-60 cells was investigated in control and cells pre-treated with diethyldithiocarbamic acid, aminotriazole and oxlalomalate, specific inhibitors of superoxide dismutase, catalase and NADP⁺-dependent isocitrate dehydrogenase, respectively. Upon exposure to rose bengal (20 μM)/light (15 min), which generates singlet oxygen, to HL-60 cells, the viability was lower and the lipid peroxidation and oxidative DNA damage were higher in inhibitor-treated cells as compared to control cells. We also observed the significant increase in the endogenous production of reactive oxygen species as well as the significant decrease in the intracellular GSH level in inhibitor-treated HL-60 cells exposed to singlet oxygen. Upon exposure to rose bengal (3 μM)/light (15 min), which induced apoptotic cell death, a clear inverse relationship was observed between the control and inhibitor-treated HL-60 cells in their susceptibility to apoptosis. These results suggest that antioxidant enzymes play an important role in cellular defense against singlet oxygen-induced cell death including necrosis and apoptosis.     

Natural antioxidants attenuate mycolactone toxicity to RAW 264.7 macrophages

Mycobacterium ulcerans produces a macrolide exotoxin, mycolactone which suppresses immune cells activity, is toxic to most cells and the key virulence factor in the pathogenesis of Buruli ulcer disease. Mycolactone is reported to mediate the production of reactive oxygen species in keratinocytes; cells that play critical role in wound healing. Increased levels of reactive oxygen species have been shown to disrupt the well-ordered process of wound repair; hence, the function of wound-healing cells such as macrophages, keratinocytes, and fibroblast could be impaired in the presence of the reactive oxygen species mediator, mycolactone. To ensure regeneration of tissues in chronic ulcers, with proper and timely healing of the wounds, natural antioxidants that can combat the effects of induced reactive oxygen species in wound-healing cells ought to be investigated. Reactive oxygen species activity was determined in mycolactone-treated RAW 264.7 macrophages and the scavenging ability of the antioxidants (ascorbic acid, gallic acid, and green tea kombucha) against mycolactone-induced reactive oxygen species (superoxide anions) was assessed using fluorescein probe (DCF-DA) and nitroblue tetrazolium dye. Cytotoxicity of the antioxidants, mycolactone, and the protective effect of the antioxidants on the cells upon treatment with mycolactone were determined using the Alamar blue assay. The expression levels of endogenous antioxidant enzyme genes (superoxide dismutase, catalase, and glutathione peroxidase) in response to mycolactone-mediated reactive oxygen species were determined using RT-qPCR. Mycolactone induced the production of reactive oxygen species in RAW 264.7 macrophages, and the resulting superoxide anions were scavenged by some of the antioxidants. The selected endogenous antioxidant enzyme genes in the macrophages were upregulated in the presence of the antioxidants and mycolactone. The exogenously supplied ascorbic acid and green tea kombucha offered moderate protection to the macrophages against the toxicity of mycolactone. We conclude that the results provide insights into alternate and adjunct therapeutic approaches in Buruli ulcer treatment, which could significantly attenuate the toxicity of the pathogenic factor; mycolactone.     

Taurine chloramine produced from taurine under inflammation provides anti-inflammatory and cytoprotective effects

Taurine is one of the most abundant non-essential amino acid in mammals and has many physiological functions in the nervous, cardiovascular, renal, endocrine, and immune systems. Upon inflammation, taurine undergoes halogenation in phagocytes and is converted to taurine chloramine (TauCl) and taurine bromamine. In the activated neutrophils, TauCl is produced by reaction with hypochlorite (HOCl) generated by the halide-dependent myeloperoxidase system. TauCl is released from activated neutrophils following their apoptosis and inhibits the production of inflammatory mediators such as, superoxide anion, nitric oxide, tumor necrosis factor-α, interleukins, and prostaglandins in inflammatory cells at inflammatory tissues. Furthermore, TauCl increases the expressions of antioxidant proteins, such as heme oxygenase 1, peroxiredoxin, thioredoxin, glutathione peroxidase, and catalase in macrophages. Thus, a central role of TauCl produced by activated neutrophils is to trigger the resolution of inflammation and protect macrophages and surrounding tissues from being damaged by cytotoxic reactive oxygen metabolites overproduced during inflammation. This is achieved by attenuating further production of proinflammatory cytokines and reactive oxygen metabolites and also by increasing the levels of antioxidant proteins that are able to scavenge and diminish the production of cytotoxic oxygen metabolites. These findings suggest that TauCl released from activated neutrophils may be involved in the recovery processes of cells affected by inflammatory oxidative stresses and thus TauCl could be used as a potential physiological agent to control pathogenic symptoms of chronic inflammatory diseases.     

Emerging potential of thioredoxin and thioredoxin interacting proteins in various disease conditions

Reactive oxygen species (ROS) are known to be mediators of intracellular signaling pathways. However the excessive production of ROS may be detrimental to the cell as a result of the increased oxidative stress and loss of cell function. Hence, well tuned, balanced and responsive antioxidant systems are vital for proper regulation of the redox status of the cell. The cells are normally able to defend themselves against the oxidative stress induced damage through the use of several antioxidant systems. Even though the free radical scavenging enzymes such as superoxide dismutase (SOD) and catalase can handle huge amounts of reactive oxygen species, should these systems fail some reactive molecules will evade the detoxification process and damage potential targets. In such a scenario, cells recruit certain small molecules and proteins as 'rescue specialists' in case the 'bodyguards' fail to protect potential targets from oxidative damage. The thioredoxin (Trx) system thus plays a vital role in the maintenance of a reduced intracellular redox state which is essential for the proper functioning of each individual cell. Trx alterations have been implicated in many diseases such as cataract formation, ischemic heart diseases, cancers, AIDS, complications of diabetes, hypertension etc. The interactions of Trx with many different proteins and different metabolic and signaling pathways as well as the significant species differences make it an attractive target for therapeutic intervention in many fields of medical science. In this review, we present, the critical roles that thioredoxins play in limiting oxidant stress through either its direct effect as an antioxidant or through its interactions with other key signaling proteins (thioredoxin interacting proteins) and its implications in various disease models.     

Augmentation of antioxidant enzymes in vascular endothelium

The endothelium is a key site of injury from reactive oxygen species that can potentially be protected by the antioxidant enzymes superoxide dismutase and catalase. Large proteins, such as superoxide dismutase and catalase, do not readily penetrate cell membranes, which limits their efficacy in protecting cells from cellular reactions involving both intracellularly and extracellularly generated reactive oxygen species. Two methods are described that promote enzyme delivery to cultured endothelial cells and confer increased resistance to oxidative stress. The first method is to entrap the antioxidant enzymes within liposomes, which then become incorporated by endothelial cells and can increase enzyme specific activities by as much as 44-fold within 2 h. The second method involves covalent conjugation of polyethylene glycol (PEG) to superoxide dismutase and catalase, a technique that increases circulatory half-life and reduces protein immunogenicity. Conjugation of PEG to superoxide dismutase and catalase increased cellular-specific activities of these enzymes in cultured endothelial cells (but at a slower rate than for liposome entrapped enzymes) and rendered these cells more resistant to oxidative stress. Both liposome-mediated delivery and PEG conjugation offer an additional benefit over native superoxide dismutase and catalase because they can increase cellular antioxidant activities in a manner that can provide protection from both intracellular and extracellular superoxide and hydrogen peroxide.     

PprI和RecX蛋白对耐辐射奇球菌抗氧化作用的影响

利用基因突变、化学发光法和酶活性分析研究了耐辐射奇球菌中与辐射抗性密切相关的基因pprI(Dr0167)和recX(Dr1310)突变对菌体活性氧清除作用的影响,分析了其对抗氧化酶活性的调控功能。实验结果表明,缺失pprI的突变株对活性氧自由基氧化异常敏感,过氧化氢酶和超氧化物歧化酶活性显著降低。与之相反,RecX对菌体活性氧清除作用表现为一种“负”的影响,即缺失recX的突变株对活性氧自由基的清除能力反而增强了,过氧化氢酶和超氧化物歧化酶的酶活性明显增加。表明这两个基因与抗氧化系统的调控有关。为进一步研究该菌的抗氧化机制提供了一些思路。     

Inhibition of antioxidants and hyperthermia enhance bleomycin-induced cytotoxicity and lipid peroxidation in Chinese hamster ovary cells.

Regional hyperthermia has potential for human cancer treatment, particularly in combination with systemic chemotherapy or radiotherapy. Heat enhances the cytotoxic effect of certain anticancer agents such as bleomycin, but the mechanisms involved in cell killing are currently unknown. Bleomycin generates reactive oxygen species. It is likely that hyperthermia itself also increases oxidative stress in cells. We evaluate whether oxidative stress has a role in the mechanism of cell death caused by bleomycin and heat in Chinese hamster ovary cells. Heat (41 to 44 degrees C) increased cytotoxicity of bleomycin, evaluated by clonogenic cell survival. Decreased levels of cellular antioxidants should create an imbalance between prooxidant and antioxidant systems, thus enhancing cytotoxic responses to heat and to oxidant-generating drugs. We determine the involvement of four major cellular antioxidant defenses, superoxide dismutase (SOD), the glutathione redox cycle (GSH cycle), catalase, and glutathione S-transferase (GST), in cellular sensitivity to bleomycin, alone or combined with hyperthermia. These cellular defenses were inhibited by diethyldithiocarbamate, l-buthionine sulfoximine, aminotriazole, and ethacrynic acid, respectively. We show that levels of antioxidants (SOD, GSH cycle, and GST) affect cellular cytotoxic responses to bleomycin, at normal and elevated temperatures (41 to 44 degrees C), suggesting the involvement of oxidative stress. Bleomycin and iron caused oxidative damage to membrane lipids in intact cells, at 37 and 43 degrees C. Lipid peroxidation was evaluated by fluorescence detection of thiobarbituric acid-reactive products. There was an increase in damage to membrane lipids when the antioxidant defenses, SOD and catalase, were inhibited. The differing effects of antioxidant inhibitors on bleomycin-induced cytotoxicity and membrane lipid damage suggest that different mechanisms are involved in these two processes. However, free radicals appear to be involved in both cases. The marked sensitization of cells by diethyldithiocarbamate, to both bleomycin-induced cytotoxicity and lipid peroxidation, suggests that superoxide could be involved in both of these processes.     

Reactive oxygen species and airway inflammation

Reactive oxygen species may be generated by several inflammatory cells which participate in airway inflammation and their production may be increased in asthma. Oxygen metabolites may contribute to the epithelial damage which is characteristic of asthmatic airways and may activate cells such as mast cells in the airway mucosa. Reactive oxygen species may cause bronchoconstriction, mucus secretion, have effects on airway vasculature, and may increase airway responsiveness. The role of reactive oxygen species in airway disease has been largely neglected, but appears to be an important area for future study. It is also possible that antioxidant defenses may be defective in asthma. If reactive oxygen species participate in the inflammatory response in airway disease, then radical scavengers or antioxidants could play a useful role in therapy.     

Radicaux libres et spermatozoïdes humains: physiologie et physiopathologie

The role of reactive oxygen species in the physiopathology of human sperm function has been emphasized in recent years. Their production in semen has been associated with loss of motility, decreased capacity for spermoocyte fusion and loss of fertility. In semen preparations, there are two major sources of reactive oxygen species: leucocytes and spermatozoa themselve. It has been proposed that reactive oxygen species production by human spermatozoa was dependent upon a membrane-bound NADPH oxidase or a mitochondrial diaphorase. Hydrogen peroxide produced by the dismutation of superoxide anion has been recognized as the most toxic oxidizing species for human spermatozoa. Owing to their high content of polyunsaturated fatty acids, it has been proposed that lipid peroxidation of the sperm plasma membrane is largely responsible for defective sperm function. Reactive oxygen species also affect the sperm axoneme as a result of ATP depletion, inhibit mitochondrial functions, and synthesis of DNA, RNA and proteins, produce cytoskeletal modifications and inhibit sperm-oocyte fusion. Human spermatozoa possess enzymatic defence systems such as superoxide dismutase, glutathion peroxidas/reductase and catalase to counteract the toxic effects induced by reactive oxygen species. Correlations have been reported between their effectiveness and the duration of sperm motility. If the excessive production of reactive oxygen species is detrimental for human spermatozoa, they could also participate in the physiological function of the spermatozoa when present at low concentrations. Indeed, reactive oxygen species have been shown to be involved in the activation of several enzymes. Furthermore, sperm capacitation, acrosome reaction and sperm-zona interaction would be enhanced by reactive oxygen species.     

Expression of bovine and mouse endothelial cell antioxidant enzymes following TNF-alpha exposure

Endothelial cells are primary targets for injury by reactive oxygen species. Endothelial catalase, copper-zinc superoxide dismutase (CuZnSOD), and manganous superoxide dismutase (MnSOD) provide potential antioxidant enzymatic defenses against oxidant-induced cellular damage. Previous studies in vivo and in vitro have demonstrated that in certain cell types exposure to oxidants may increase the expression of one or more of these antioxidant enzymes, thus providing greater intracellular potential to withstand oxidant-induced cell stress. To test whether endothelial antioxidant enzyme expression is influenced by similar oxidant-induced stresses in vitro, we have exposed endothelial cells to tumor necrosis factor-alpha (TNF-alpha) and have measured levels of catalase, CuZnSOD and MnSOD mRNA, and protein. Our results demonstrate a selective increase of MnSOD mRNA, with coordinate increases of both MnSOD protein and enzyme activity in endothelial cells treated for 24/h with TNF-alpha. In contrast, levels of catalase and CuZnSOD mRNA and protein remained unchanged in these cells after TNF-alpha treatment. These observations were made in microvessel endothelial cells derived from murine and bovine sources. Our results indicate that TNF-alpha can act specifically to increase enzymatic antioxidant potential in endothelial cells by induction of a particular antioxidant enzyme encoding mRNA species. These data demonstrate the capacity of endothelial cells to mount an antioxidant defense in response to exposure to an inducer of oxidative damage.     

Differences in the reducing power along the rat GI tract: Lower antioxidant capacity of the colon

The ability of the gastrointestinal (GI) tract, as well as other tissues, to cope with reactive oxygen species (ROS) efflux in pathological events is determined partly by epithelial antioxidant levels. These levels are comprized of tissue antioxidant enzymes and low molecular weight antioxidants (LMWA). While glutathione levels and the activity of enzymatic antioxidants along the GI tract have been studied, the contribution of the overall LMWA to the total antioxidant capacity has not yet been determined. In this study the overall antioxidant activity in the mucosa/submucosa and muscularis/serosa of various sections along the small intestine and colon of the rat was evaluated by determining the reducing power, which reflects the total antioxidant activity derived from LMWA, using cyclic voltammetry. The activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase was also measured. The reducing power (total antioxidant activity) was higher in the mucosa/submucosa of the small intestine as compared to the mucosa/submucosa of the colon. Similarly, catalase and SOD activity in the mucosa/submucosa of the small intestine was significantly higher than in the mucosa/submucosa of the colon. Differences were also observed in the reducing power and SOD activity in the muscularis/serosa of the rat small intestine as compared to the colon. The low antioxidant capacity in the colon may facilitate reactive oxygen species (ROS)-mediated injury and lead to inflammatory diseases such as ulcerative colitis, specifically in the colon.     

N-acetylcysteine protects mice from lethal endotoxemia by regulating the redox state of immune cells

The excessive production of reactive oxygen species (ROS) associated with inflammation leads to oxidative stress, which is involved with the high mortality from several diseases such as endotoxic shock and can be controlled to a certain degree by antioxidants. The immune cells use ROS in order to support their functions and, therefore, need adequate levels of antioxidant defenses in order to avoid the harmful effect of an excessive ROS production. In the present work, the effect of the administration of the antioxidant N-acetylcysteine (NAC) on the redox state of peritoneal macrophages and lymphocytes from mice with lethal endotoxic shock (100 mg/kg i.p. of lipopolysaccharide, LPS), was studied. In both types of immune cells at 0, 2, 4, 12 and 24 h after LPS injection, an increase of ROS, of the proinflammatory cytokine tumor necrosis factor alpha (TNFalpha), the lipid peroxidation (malonaldehyde levels, MDA), inducible nitric oxide synthase (iNOS) expression and the oxidized/reduced glutathione (GSSG/GSH) ratio, as well as a decrease of enzymatic antioxidant defenses, such as superoxide dismutase (SOD) and catalase (CAT) activity, was observed. The injection of NAC (150 mg/kg i.p. at 30 min after LPS injection) decreased the ROS, the TNFalpha the MDA levels, iNOS expression and the GSSG/GSH ratio, and increased the antioxidant defenses in both macrophages and lymphocytes. Moreover, the NAC treatment prevented the activation of nuclear translocation of the nuclear factor kappaB (NF-kappaB), which regulates ROS, inflammatory cytokines and antioxidant levels. Our present results provide evidence that both cell types have a relevant role in the pathogenesis of endotoxic shock, and that NAC, by improving the redox state of these immune cells, could increase mouse survival. Thus, antioxidants could offer an alternative treatment of human endotoxic shock.     

N-acetylcysteine Protects Mice from Lethal Endotoxemia by Regulating the Redox State of Immune Cells

The excessive production of reactive oxygen species (ROS) associated with inflammation leads to oxidative stress, which is involved with the high mortality from several diseases such as endotoxic shock and can be controlled to a certain degree by antioxidants. The immune cells use ROS in order to support their functions and, therefore, need adequate levels of antioxidant defenses in order to avoid the harmful effect of an excessive ROS production. In the present work, the effect of the administration of the antioxidant N-acetylcysteine (NAC) on the redox state of peritoneal macrophages and lymphocytes from mice with lethal endotoxic shock (100 mg/kg i.p. of lipopolysaccharide, LPS), was studied. In both types of immune cells at 0, 2, 4, 12 and 24 h after LPS injection, an increase of ROS, of the proinflammatory cytokine tumor necrosis factor alpha (TNFα), the lipid peroxidation (malonaldehyde levels, MDA), inducible nitric oxide synthase (iNOS) expression and the oxidized/reduced glutathione (GSSG/GSH) ratio, as well as a decrease of enzymatic antioxidant defenses, such as superoxide dismutase (SOD) and catalase (CAT) activity, was observed. The injection of NAC (150 mg/kg i.p. at 30 min after LPS injection) decreased the ROS, the TNFα the MDA levels, iNOS expression and the GSSG/GSH ratio, and increased the antioxidant defenses in both macrophages and lymphocytes. Moreover, the NAC treatment prevented the activation of nuclear translocation of the nuclear factor κB (NF-κB), which regulates ROS, inflammatory cytokines and antioxidant levels. Our present results provide evidence that both cell types have a relevant role in the pathogenesis of endotoxic shock, and that NAC, by improving the redox state of these immune cells, could increase mouse survival. Thus, antioxidants could offer an alternative treatment of human endotoxic shock.     

Zymogram profiling of superoxide dismutase and catalase activities allows Saccharomyces and non-Saccharomyces species differentiation and correlates to their fermentation performance

Aerobic organisms have devised several enzymatic and non-enzymatic antioxidant defenses to deal with reactive oxygen species (ROS) produced by cellular metabolism. To combat such stress, cells induce ROS scavenging enzymes such as catalase, peroxidase, superoxide dismutase (SOD) and glutathione reductase. In the present research, we have used a double staining technique of SOD and catalase enzymes in the same polyacrylamide gel to analyze the different antioxidant enzymatic activities and protein isoforms present in Saccharomyces and non-Saccharomyces yeast species. Moreover, we used a technique to differentially detect Sod1p and Sod2p on gel by immersion in NaCN, which specifically inhibits the Sod1p isoform. We observed unique SOD and catalase zymogram profiles for all the analyzed yeasts and we propose this technique as a new approach for Saccharomyces and non-Saccharomyces yeast strains differentiation. In addition, we observed functional correlations between SOD and catalase enzyme activities, accumulation of essential metabolites, such as glutathione and trehalose, and the fermentative performance of different yeasts strains with industrial relevance.