Showing papers on "Catalase published in 2018"
TL;DR: It is clearly evident that CAT, ascorbate-glutathione cycle and SOD played a significant activity in ROS detoxification of tolerant A. tricolor variety.
Abstract: The study was performed to explore physiological, non-enzymatic and enzymatic detoxification pathways of reactive oxygen species (ROS) in tolerance of Amaranthus tricolor under drought stress. The tolerant genotype VA13 exhibited lower reduction in growth, photosynthetic pigments, relative water content (RWC) and negligible increment in electrolyte leakage (EL), lower increment in proline, guaiacol peroxidase (GPOX) activity compared to sensitive genotype VA15. This genotype also had higher catalase (CAT), superoxide dismutase (SOD), remarkable and dramatic increment in ascorbate-glutathione content, ascorbate-glutathione redox and ascorbate-glutathione cycle enzymes activity compared to sensitive genotype VA15. The negligible increment of ascorbate-glutathione content, ascorbate-glutathione redox and ascorbate-glutathione cycle enzymes activities and dramatic increment in malondialdehyde (MDA), hydrogen peroxide (H2O2) and EL were observed in the sensitive genotype VA15. SOD contributed superoxide radical dismutation and CAT contributed H2O2 detoxification in both sensitive and tolerant varieties, however, these had a great contribution in the tolerant variety. Conversely, proline and GPOX accumulation were higher in the sensitive variety compared to the tolerant variety. Increase in ascorbate-glutathione cycle enzymes activities, CAT, ascorbate-glutathione content, SOD, and ascorbate-glutathione redox clearly evident that CAT, ascorbate-glutathione cycle and SOD played a significant activity in ROS detoxification of tolerant A. tricolor variety.
205 citations
TL;DR: Assessment of environmentally relevant concentrations of Se toxicity in Mozambique tilapia, Oreochromis mossambicus showed that Se accumulation was observed in the gill, liver and brain tissues of fish exposed to different concentrations and accumulation varied upon different tissues.
167 citations
TL;DR: This spectrophotometric method is appropriate for analyzing bacteria, red blood cells and liver and kidney tissue homogenates and was established for biological samples and depends on the rapid formation of a stable and colored carbonato-cobaltate (III) complex.
Abstract: The details of a precise, accurate, and sensitive spectrophotometric method for measuring catalase activity are presented here. The assay was established for biological samples and depends on the rapid formation of a stable and colored carbonato-cobaltate (III) complex. Samples exhibiting catalase activity are incubated with hydrogen peroxide solution for 2 min prior to rapid mixing of the incubation enzymatic reaction mixture with cobalt-bicarbonate reagent, which assesses non-reacting hydrogen peroxide. Catalase activity is always directly proportional to the rate of dissociation of hydrogen peroxide. Hydrogen peroxide acts to oxidize cobalt (II) to cobalt (III) in the presence of bicarbonate ions; this process ends with the production of a carbonato-cobaltate (III) complex ([Co (CO3)3]Co). The formed end product has two maximum absorbance peaks: 440 nm and 640 nm. The 440-nm peak has been utilized for assessing catalase activity. The catalase activity results of the current method for erythrocyte lysate homogenates were computationally identical to those of the dichromate method (r = 0.9950). The coefficient of variation was calculated to determine the imprecision of the current assay. The within-run and between-run results were 2.96 and 3.83%, respectively. This method is appropriate for analyzing bacteria, red blood cells and liver and kidney tissue homogenates.
161 citations
TL;DR: The findings indicate that the delay of pericarp browning and senescence by melatonin in harvested litchi fruit could be attributed to the maintenance of redox homeostasis by the improvement of the antioxidant capacity and modulation of the repair of oxidatively damaged proteins.
Abstract: Melatonin acts as a crucial signaling and antioxidant molecule with multiple physiological functions in organisms. To explore effects of exogenous melatonin on postharvest browning and its possible mechanisms in litchi fruit, 'Ziniangxi' litchi fruits were treated with an aqueous solution of melatonin at 0.4 mM and then stored at 25 °C for 8 days. The results revealed that melatonin strongly suppressed pericarp browning and delayed discoloration during storage. Melatonin treatment reduced relative membrane-leakage rate and inhibited the generation of superoxide radicals (O2-·), hydrogen peroxide (H2O2), and malondialdehyde (MDA). Melatonin treatment markedly promoted the accumulation of endogenous melatonin; delayed loss of total phenolics, flavonoids, and anthocyanins; and enhanced the activities of antioxidant enzymes, including superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), and glutathione reductase (GR, EC 1.6.4.2). By contrast, the activities of browning-related enzymes including polyphenoloxidase (PPO, EC 1.10.3.1) and peroxidase (POD, EC 1.11.1.7) were reduced. In addition, melatonin treatment up-regulated the expression of four genes encoding enzymes for repair of oxidized proteins, including LcMsrA1, LcMsrA2, LcMsrB1, and LcMsB2. These findings indicate that the delay of pericarp browning and senescence by melatonin in harvested litchi fruit could be attributed to the maintenance of redox homeostasis by the improvement of the antioxidant capacity and modulation of the repair of oxidatively damaged proteins.
147 citations
TL;DR: Melatonin delayed aging of kiwifruit leaves by activating the antioxidant capacity and enhancing flavonoid biosynthesis and can provide clear proof that melatonin plays a key roles in delaying leaf senescence.
Abstract: Melatonin, a multiple signal molecule, plays important roles in delaying senescence during the development of plants. Because few species have been studied for the effect of exogenous melatonin on anti-aging, the plausible mechanism of melatonin of anti-aging effects on other plant species has remained largely unknown. In the present study, the effects of exogenous melatonin on leaf senescence in kiwifruit were examined during natural aging after melatonin (200 μM) or water (Control) pretreatment. The decreased membrane damage and lower hydrogen peroxide (H2O2) content due to the enhanced scavenging activity of antioxidant enzymes peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) demonstrated that melatonin effectively delayed the aging of kiwifruit leaves. Likewise, owing to up-regulated expression of chlorophyll a/b-binding protein (CAB) gene in the sampled leaves pretreated with melatonin, chlorophyll degradation decreased. Therefore, osmoregulatory substances in sampled leaves accumulated (e.g., soluble sugar and soluble protein) and seedling cell environment stability was maintained. Simultaneously, melatonin decreased H2O2 concentration owing to increased glutathione (GSH) and ascorbate (AsA) content, and the expression levels of glutathione reductase (GR), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR) were up-regulated by melatonin application, indicating that the increase of GSH and AsA was attributed to the expression of these genes. In addition, a large amount of flavonoids accumulated in seedlings pretreated with melatonin, and transcript levels of eight genes involved in flavonoid synthesis, including phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxymate (C4H), chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), flavonol synthase (FNS), leucoanthocyanin reductase (LAR), anthocyanin reductase (ANR), flavonoid 3-O-glucosyltransferase (UFGT) were enhanced in response to melatonin application. These results indicated that melatonin delayed aging of kiwifruit leaves by activating the antioxidant capacity and enhancing flavonoid biosynthesis. All of these results can provide clear proof that melatonin plays a key roles in delaying leaf senescence.
127 citations
TL;DR: The use and application of catalase is reviewed as an indicator of hydrocarbon degradation in soil, as a provider of oxygen in aerobic bioremediation process and in the removal of H2O2 from bleaching industry effluent and also its potential use in the food industry.
Abstract: The enzyme catalase is known to catalyse the breakdown of hydrogen peroxide into oxygen and water. Hydrogen peroxide metabolism is mainly regulated by this enzyme. Catalase is a common enzyme found in nearly all living organisms. It has one of the highest turnovers of all enzymes as it has the capacity to decompose more than one million molecules of hydrogen peroxide, per molecule of enzyme. Catalase has been used as an important enzyme in many biotechnological areas including bioremediation. This paper gives a review of its use and application in the field of bioremediation as an indicator of hydrocarbon degradation in soil (an important aspect in bioremediation of crude oil pollution), as a provider of oxygen in aerobic bioremediation process and in the removal of H2O2 from bleaching industry effluent and also its potential use in the food industry.
126 citations
TL;DR: This study revealed a crucial protective role of melatonin in the regulation of cadmium resistance in wheat and suggested that melatonin played a key role in maintaining the hydrogen peroxide homeostasis, via regulation of the antioxidant systems.
Abstract: Melatonin has emerged as a research highlight regarding its important role in regulating plant growth and the adaptation to the environmental stresses. In this study, we investigated how melatonin prevented the cadmium toxicity to wheat seedlings. The results demonstrated that cadmium induced the expression of melatonin biosynthesis-related genes and cause a significant increase of endogenous melatonin level. Melatonin treatment drastically alleviated the cadmium toxicity, resulting in increased plant height, biomass accumulation, and root growth. Cadmium and senescence treatment significantly increased the endogenous level of hydrogen peroxide, which was strictly counterbalanced by melatonin. Furthermore, melatonin treatment caused a significant increase of GSH (reduced glutathione) content and the GSH/GSSG (oxidized glutathione) ratio. The activities of two key antioxidant enzymes, ascorbate peroxidase (APX) and superoxide dismutase (SOD), but not catalase (CAT) and peroxidase (POD), were specifically improved by melatonin. Additionally, melatonin not only promoted the primary root growth, but also drastically enhanced the capacity of the seedling roots to degrade the exogenous hydrogen peroxide. These results suggested that melatonin played a key role in maintaining the hydrogen peroxide homeostasis, via regulation of the antioxidant systems. Conclusively, this study revealed a crucial protective role of melatonin in the regulation of cadmium resistance in wheat.
112 citations
TL;DR: Overall, exogenous nano-silicon alleviated the salt stress by increase in K+ concentration, antioxidant activities, non-enzymatic compounds and decreasing of Na+, concentration, lipid peroxidation, and reactive oxygen species production.
Abstract: Materials with a particle size less than 100 nm are classified as nano-materials. The physical and chemical properties of nano-materials can vary considerably from those of bulk materials of the same composition. Silicon (Si) still fails to get recognized as an essential nutrient for plant growth and development, however the beneficial effects in terms of growth, biotic and abiotic stress resistance have been indicated in a variety of plant species for their growth. The aim of this study was to investigate the effects of different nano-silicon rates on the growth and antioxidant activities of soybean (Glycine max L. cv. M7) under salt stress. The results showed that salinity decreased shoot and root dry weight, potassium (K+) concentration in the root and leaf; however, increased sodium (Na+) concentration, catalase, peroxidase, ascorbate peroxidase and superoxide dismutase activities, phenolic components, ascorbic acid and α-tocopherol contents, lipid peroxidation, hydrogen peroxide, and oxygen radical’s concentration. Between the treatments, 0.5 and 1 mM of nanosilicon oxide (nano-SiO2) improved shoot and root growth of seedlings. In contrast, a foliar application of SiO2 at 2 mM reduced the soybean growth. Overall, exogenous nano-silicon alleviated the salt stress by increase in K+ concentration, antioxidant activities, non-enzymatic compounds and decreasing of Na+ concentration, lipid peroxidation, and reactive oxygen species production.
112 citations
TL;DR: The increased p53 levels detected in Cu or/and As treated chickens suggest the possibility that the NF-kB/p53 axis might lead to the impairment of immune-apoptosis cross talk in the present model.
111 citations
TL;DR: The results of the present study suggest that exogenous application of NO and ALA could be useful to enhance the drought tolerance of canola plants by up-regulating the oxidative defense system, osmoprotectant accumulation, and minimizing the lipid peroxidation.
Abstract: To minimize the damaging effects of stresses, plant growth regulators (PGRs) are widely used to sustain the plant life under stress-prone environments. So, a study was carried out to evaluate the response of two canola (Brassica napus L.) cultivars, Dunkeld and Cyclone, to foliar-applied two potential PGRs, nitric oxide (NO) and 5-aminolevulinic acid, under water deficit conditions. In this study, the levels of NO and ALA used were 0.02 and 0.895 mM, respectively. Plants of both canola cultivars were subjected to control (100% field capacity) and water deficit (60% field capacity). Drought stress significantly decreased growth, chlorophyll pigments, relative water contents (RWC), and soluble proteins, while it increased relative membrane permeability (RMP), proline, glycinebetaine (GB), malondialdehyde (MDA), total phenolics, and activities of catalase (CAT) and peroxidase (POD) enzymes in both cultivars. Foliar application of PGRs improved growth, chlorophyll a, GB, total phenolics, CAT activity, and total soluble proteins, while it decreased RMP, MDA, and POD activity in both canola cultivars. Other physio-biochemical attributes such as chlorophyll b, RWC, hydrogen peroxide (H2O2) and proline contents as well as superoxide dismutase (SOD) activity remained unaffected due to application of PGRs. So, the results of the present study suggest that exogenous application of NO and ALA could be useful to enhance the drought tolerance of canola plants by up-regulating the oxidative defense system, osmoprotectant accumulation, and minimizing the lipid peroxidation.
109 citations
TL;DR: Exogenous SNP-mediated modulation of endogenous NO enhanced rice tolerance to Ni-stress by restricting Ni accumulation, maintaining photosynthetic performance and reducing oxidative damage through improved antioxidant system, thereby suggesting NO as an effective stress regulator in mitigating Ni-toxicity in economically important rice, and perhaps in other crop plants.
TL;DR: It is revealed that low temperature and air exposure caused significant oxidative and antioxidant responses, but did not lead to irreversible damages in this waterless system.
TL;DR: The ability of tomato plants to tolerate salt stress when supplemented with EBL and Ca was attributed to modifications to enzymatic and non-enzymatic antioxidants, osmolytes and metabolites.
Abstract: The present study tested the efficacy of 24-epibrassinolide (EBL) and calcium (Ca) for mediating salinity tolerance in tomato Salinity stress affected the morphological parameters of tomato as well as leaf relative water content (LRWC), photosynthetic and accessory pigments, leaf gas exchange parameters, chlorophyll fluorescence and the uptake of essential macronutrients The salt (NaCl) treatment induced oxidative stress in the form of increased Na+ ion concentration by 146%, electrolyte leakage (EL) by 6111%, lipid peroxidation (MDA) 167% and hydrogen peroxide (H2O2) content by 175% Salt stress also enhanced antioxidant enzyme activities including those in the ascorbate–glutathione cycle Plants treated with EBL or Ca after salt exposure mitigated the ill effects of salt stress, including oxidative stress, by reducing the uptake of Na+ ions by 52% The combined dose of EBL + Ca reversed the salt-induced changes through an elevated pool of enzymes in the ascorbate–glutathione cycle, other antioxidants (superoxide dismutase, catalase), and osmoprotectants (proline, glycine betaine) Exogenously applied EBL and Ca help to optimize mineral nutrient status and enable tomato plants to tolerate salt toxicity The ability of tomato plants to tolerate salt stress when supplemented with EBL and Ca was attributed to modifications to enzymatic and non-enzymatic antioxidants, osmolytes and metabolites
TL;DR: The results suggest that Cu2+ causes oxidative stress to the maize leaves which then activates defense antioxidant enzymes via MAPK pathway, and the signaling pathway is Cu2—H2O2—ZmMPK3—antioxidant enzymes.
Abstract: Copper (Cu) is a necessary trace element participated in many physiological processes in plants. But excessive Cu2+ is toxic, which can activate intracellular signals that lead to cellular damage. The mitogen-activated protein kinase (MAPK) cascade is at the center of cell signal transduction and has been reported to be involved in stress-related signaling pathways. ZmMPK3, a kind of MAPKs in maize cells, can be activated by diverse abiotic stresses. In the present study, we investigated the effects of Cu2+ on hydrogen peroxide (H2O2) level, ZmMPK3 activity as well as the activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and ascorbic acid peroxidase (APX) using maize leaf as an experimental model. The results demonstrated that acute Cu2+ exposure for 24 hours led to rapid increases of H2O2 level and the increase in ZmMPK3 activity as well as the total activities of antioxidant enzymes SOD, CAT and APX. H2O2 scavenger, dimethylthiourea (DMTU), effectively inhibited the Cu2+-increased H2O2 level and the activity of ZmMPK3 as well as the activities of the antioxidant enzymes SOD, CAT and APX. Pre-treatment with the MAPK inhibitor, PD98059, significantly blocked the Cu2+-increased activities of ZmMPK3, CAT, APX and SOD, but didn't affect the accumulation of H2O2. Our results suggest that Cu2+ causes oxidative stress to the maize leaves which then activates defense antioxidant enzymes via MAPK pathway. Thus, the signaling pathway is Cu2+-H2O2-ZmMPK3-antioxidant enzymes.
TL;DR: Observations confirmed that ROS-mediated oxidative stress participates in the activation of the apoptotic cascade reaction involving Ca2+ and Bcl-2 family proteins, and suggested that ROS plays a significant role in meat tenderization through the mitochondrial apoptotic pathway.
TL;DR: It is suggested that the application of pesticides above the recommended dose can provoke the state of oxidative stress and can cause oxidative damages in non-target host plants.
Abstract: Excessive use of pesticides can adversely affect the growth of non-target host plants in different ways. Pesticide-induced stress can affect non-target plants through elevated levels of reactive oxygen species (ROS) responsible for detrimental effects on cell metabolism, biochemical and other physiological activities. In response to oxidative stress, plant activates antioxidant defense system consisting of both enzymatic and non-enzymatic components. In the present investigation, three commonly used pesticides, emamectin benzoate, alpha-cypermethrin and imidacloprid, were assessed for causing oxidative stress in tomato. The oxidative damage induced by these pesticides at five different concentrations i.e. 1/4X, 1/2X, recommended application dose (X), 2X and 4X in the root and shoot tissues of tomato plant/seedlings were evaluated. Following pesticide exposure for 35 days, cell viability, cell injury, total soluble sugar (TSS) and total soluble proteins (TSP) were measured. Antioxidant activities were estimated by measuring activity levels of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) peroxidase (POD), ascorbate peroxidase (APX) and proline. Hydrogen peroxide (H2O2) levels were analysed as ROS, lipid peroxidation was measured in term of thiobarbituric acid reactive substances (TBARS) as membrane damage caused by ROS was also assessed. Analysis of the data revealed that pesticides application at higher concentrations significantly elevated ROS levels and caused membrane damage by the formation of TBARS, increased cell injury and reduced cell viability both in root and shoot tissues compared with non-treated plants. Moreover, a gradual decrease in the levels of TSS and TSP was observed in plants subjected to increasing doses of pesticides. To cope with pesticide-induced oxidative stress, a significant increase in levels of antioxidants was observed in the plants exposed to higher doses of pesticides. Shoot tissues responded more drastically by producing higher levels of antioxidants as compared to root tissues indicating the direct exposure of shoots to foliar application of pesticides. Taken together, these results strongly suggested that the application of pesticides above the recommended dose can provoke the state of oxidative stress and can cause oxidative damages in non-target host plants.
TL;DR: Analysis of anoxidative responses of P. chrysosporium under the single and combined treatments of AgNPs and Ag+, HAADF-STEM, SEM, and EDX demonstrated that AgNP-induced cytotoxicity could originate from the original AgNps, rather than dissolved Ag+ or the biosynthesized AgN Ps.
TL;DR: P Piperlongumine bound to OXR1 directly and induced its degradation through the ubiquitin‐proteasome system in an SC‐specific manner, providing new insights into the mechanism by which SCs are highly resistant to oxidative stress.
Abstract: The selective depletion of senescent cells (SCs) by small molecules, termed senolytic agents, is a promising therapeutic approach for treating age-related diseases and chemotherapy- and radiotherapy-induced side effects. Piperlongumine (PL) was recently identified as a novel senolytic agent. However, its mechanism of action and molecular targets in SCs was unknown and thus was investigated. Specifically, we used a PL-based chemical probe to pull-down PL-binding proteins from live cells and then mass spectrometry-based proteomic analysis to identify potential molecular targets of PL in SCs. One prominent target was oxidation resistance 1 (OXR1), an important antioxidant protein that regulates the expression of a variety of antioxidant enzymes. We found that OXR1 was upregulated in senescent human WI38 fibroblasts. PL bound to OXR1 directly and induced its degradation through the ubiquitin-proteasome system in an SC-specific manner. The knockdown of OXR1 expression by RNA interference significantly increased the production of reactive oxygen species in SCs in conjunction with the downregulation of antioxidant enzymes such as heme oxygenase 1, glutathione peroxidase 2, and catalase, but these effects were much less significant when OXR1 was knocked down in non-SCs. More importantly, knocking down OXR1 selectively induced apoptosis in SCs and sensitized the cells to oxidative stress caused by hydrogen peroxide. These findings provide new insights into the mechanism by which SCs are highly resistant to oxidative stress and suggest that OXR1 is a novel senolytic target that can be further exploited for the development of new senolytic agents.
TL;DR: Findings provide strong evidence that Cu could induce autophagy by generating excessive ROS in hepatocytes, and Autophagy might attenuate Cu-induced mitochondrial dysfunction by regulating oxidative stress.
TL;DR: The stronger drought-tolerance of Longzhong was attributed to its higher osmotic adjustment capacity, greater ability to orchestrate its enzymatic and non-enzymatic antioxidant systems and thus avoid great oxidative damage in comparison to Gannong No. 3.
Abstract: Drought severely limits global plant distribution and agricultural production. Elucidating the physiological and molecular mechanisms governing alfalfa stress responses will contribute to the improvement of drought tolerance in leguminous crops. In this study, the physiological and proteomic responses of two alfalfa (Medicago sativa L.) varieties contrasting in drought tolerance, Longzhong (drought-tolerant) and Gannong No. 3 (drought-sensitive), were comparatively assayed when seedlings were exposed to -1.2 MPa polyethylene glycol (PEG-6000) treatments for 15 days. The results showed that the levels of proline, malondialdehyde (MDA), hydrogen peroxide (H2O2), hydroxyl free radical (OH•) and superoxide anion free radical (O2•-) in both varieties were significantly increased, while the root activity, the superoxide dismutase (SOD) and glutathione reductase (GR) activities, and the ratios of reduced/oxidized ascorbate (AsA/DHA) and reduced/oxidized glutathione (GSH/GSSG) were significantly decreased. The soluble protein and soluble sugar contents, the total antioxidant capability (T-AOC) and the activities of peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) first increased and then decreased with the increase in treatment days. Under osmotic stress, Longzhong exhibited lower levels of MDA, H2O2, OH• and O2•- but higher levels of SOD, CAT, APX, T-AOC and ratios of AsA/DHA and GSH/GSSG compared with Gannong No.3. Using isobaric tags for relative and absolute quantification (iTRAQ), 142 differentially accumulated proteins (DAPs) were identified from two alfalfa varieties, including 52 proteins (34 up-regulated and 18 down-regulated) in Longzhong, 71 proteins (28 up-regulated and 43 down-regulated) in Gannong No. 3, and 19 proteins (13 up-regulated and 6 down-regulated) shared by both varieties. Most of these DAPs were involved in stress and defense, protein metabolism, transmembrane transport, signal transduction, as well as cell wall and cytoskeleton metabolism. In conclusion, the stronger drought-tolerance of Longzhong was attributed to its higher osmotic adjustment capacity, greater ability to orchestrate its enzymatic and non-enzymatic antioxidant systems and thus avoid great oxidative damage in comparison to Gannong No. 3. Moreover, the involvement of other pathways, including carbohydrate metabolism, ROS detoxification, secondary metabolism, protein processing, ion and water transport, signal transduction, and cell wall adjustment, are important mechanisms for conferring drought tolerance in alfalfa.
TL;DR: In this article, the role of epigallocatechin-3-gallate (EGCG) in the plant response to salt stress in tomato was investigated using a series of EGCG concentrations (10, 100, and 1000 µM).
Abstract: Salinity is a global environmental problem, restricting crop production in a vast area of agricultural land. Although epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in tea plants, has a strong antioxidative action in vitro, the role of EGCG in the plant response to salt stress remains unknown. In the present study, using a series of EGCG concentrations (10, 100, and 1000 µM), we showed that EGCG could alleviate salt stress-induced inhibition in seed germination and root growth in tomato. Exogenous EGCG increased not only the seed germination rate, but also the germination energy and germination index under salt stress. The 150 mM NaCl treatment significantly increased lipid peroxidation in roots by excessive accumulation of reactive oxygen species (ROS). In contrast, EGCG treatment, particularly at 100 µM concentration, mitigated NaCl-induced oxidative stress as evidenced by the decreased H2O2 and malondialdehyde content in roots. Analysis of the antioxidant enzyme system reveals that EGCG increased the activity of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase under salt stress. Considering the beneficial effect of EGCG on seed germination, root growth, ROS scavenging, and antioxidant enzyme activity, the 100 µM EGCG treatment appears to be the most effective concentration of those tested under salt stress in tomato. Our results suggest that the EGCG-promoted tomato tolerance to salt stress is associated with the mitigation of oxidative stress through an efficient ROS scavenging mechanism by the action of enhanced antioxidant enzyme activity. Thus, the enhancement of plant tolerance by exogenous EGCG can potentially expand crop cultivation in saline soils.
TL;DR: The results suggested that, by regulating endogenous PAs-mediated H2O2 signaling in roots, Spd could enhance antioxidant enzyme activities and reduce oxidative damage; the main source of H 2O2 was polyamine oxidation, which was associated with improved tolerance and root growth recovery of cucumber under salt stress.
TL;DR: The data showed that resveratrol increased lifespan of D. melanogaster in a dose-dependent manner up to 60 mg/kg diet and restored MPTP-induced inhibition of catalase, glutathione-S-transferase and acetylcholinesterase activities in D.–melanogsaster.
TL;DR: The current knowledge on oxidative stress and antioxidant imbalance in asthma is summarized, possible biomarkers of oxidative stress in asthma are focused on, and current and future treatment strategies using the modulation of oxidative Stress to treat asthma patients are focus on.
Abstract: An imbalance between the production of reactive oxygen species and the capacity of antioxidant defense mechanisms favoring oxidants is called oxidative stress and is implicated in asthmatic inflammation and severity. Major reactive oxygen species that are formed endogenously include hydrogen peroxide, superoxide anion, hydroxyl radical, and hypohalite radical; and the major antioxidants that fight against the endogenous and environmental oxidants are superoxide dismutase, catalase, and glutathione. Despite the well-known presence of oxidative stress in asthma, studies that target oxidative burden using a variety of nutritional, pharmacological, and environmental approaches have generally been disappointing. In this review, we summarize the current knowledge on oxidative stress and antioxidant imbalance in asthma. In addition, we focus on possible biomarkers of oxidative stress in asthma and on current and future treatment strategies using the modulation of oxidative stress to treat asthma patients.
TL;DR: It is demonstrated that MT could induce the expression of MAPKs and TFs and regulate theexpression of downstream stress-responsive genes, thereby increasing the plant’s tolerance, which may provide a new idea for MT modulation in the regulation of plant antioxidant defenses.
Abstract: Melatonin (N-acetyl-5-methoxytryptamine, MT) is a molecule with pleiotropic effects including antioxidant activity, regulated plant growth, development, and reduced environmental stress in plants. However, only a few studies have analyzed the effect of exogenous MT on drought stress in naked oat seedlings. Therefore, in this study, we studied the effects of exogenous MT on the antioxidant capacity of naked oat under drought stress to understand the possible antioxidant mechanism. The results showed that a pretreatment of 100 μM MT reduced the hydrogen peroxide (H2O2) and superoxide anion (O2−•) contents. MT also enhanced superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activities in the leaves of naked oat seedlings under 20% PEG-6000 drought stress. MT upregulated the expression levels of the mitogen-activated protein kinases (MAPKs) Asmap1 and Aspk11, and the transcription factor (TF) genes (except for NAC), WRKY1, DREB2, and MYB increased in drought with MT pretreatment seedlings when compared with seedlings exposed to drought stress alone. These data indicated that the MT-mediated induction of the antioxidant response may require the activation of reactive oxygen species (ROS) and MAPK, followed by triggering a downstream MAPK cascade such as Asmap1 and Aspk11, to regulate the expression of antioxidant-related genes. This study demonstrated that MT could induce the expression of MAPKs and TFs and regulate the expression of downstream stress-responsive genes, thereby increasing the plant’s tolerance. This may provide a new idea for MT modulation in the regulation of plant antioxidant defenses. These results provide a theoretical basis for MT to alleviate drought stress in naked oat.
TL;DR: In this paper, the authors demonstrated that As2O3 exposure induced oxidative stress and inflammatory-mediated nephrotoxicity in a dose-and time-dependent manner, eventually leading to apoptosis through a mitochondria-dependent pathway in chicken kidneys.
Abstract: The kidney is the most crucial site for the excretion of arsenic and its metabolites. In this study, Hy-line chickens exposed to different toxicologically relevant doses of arsenic (0, 7.5, 15 and 30 mg kg-1 diet) presented marked renal injury as evidenced by the increased leakage of blood urea nitrogen (up to 2.6 folds) and creatinine (up to 2.3 folds). Furthermore, increased content of renal arsenic (up to 30 folds) and malondialdehyde restrained anti-hydroxyl radical ability, and the activities of antioxidant enzymes (glutathione peroxidase, catalase) further corroborated extensive renal damage. Meanwhile, as another cellular adaptive survival strategy, inflammation responses were quickly detected upon arsenic exposure as evidenced by elevated nuclear migration of nuclear factor-κB (NF-κB) and inflammation-related phenotypes. It was further noted that arsenic-induced mitochondrial damage was accompanied by accumulation of p53 initiated mitochondrial apoptosis pathway in nephrocyte, eventually elevating the apoptosis rate (up to 9.1 folds) compared to that of the control groups. Noticeably, correlation analysis illustrated that this mitochondrial apoptotic pathway was initiated following oxidative stress and inflammatory response. This study demonstrated that As2O3 exposure induced oxidative stress and inflammatory-mediated nephrotoxicity in a dose- and time-dependent manner, eventually leading to apoptosis through a mitochondria-dependent pathway in chicken kidneys.
TL;DR: In this paper, the role of ligand donor sites, endogenous acid/base groups, metal environment and second-sphere effects in the catalytic activity of synthetic mononuclear Mn complexes with SOD and/or CAT activity is discussed.
TL;DR: High arsenate treatment could cause an increasing oxidative stress, which can be scavenged by the antioxidant enzyme, and high phosphate treatments had a positive effect on GR activity, which may be due to regulation of glutathione biosynthesis within the plants.
Abstract: The present study investigated the effects of arsenate and phosphate interaction on growth, lipid peroxidation, arsenic (As) accumulation, phosphorus (P) accumulation, and the activities of some antioxidant enzymes in Isatis cappadocica. Plants were exposed to (50–1200 μmol L−1) arsenate and (5–1600 μmol L−1) phosphate for 28 days in a hydroponic system. At a phosphate concentration of 1600 µM, biomass production and chlorophyll content increased, demonstrating clearly that phosphate was able to provide protection against As toxicity. In case of joint application of 1600 µM phosphate with arsenate, the As accumulation and then lipid peroxidation were decreased when compared to samples treated with arsenate and 5 µM phosphate. The activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione reductase (GR) increased with increasing arsenate supply levels. Addition of P decreased activities of SOD, APX and CAT, while high phosphate treatments had a positive eff...
TL;DR: The results showed that H2O2 induced by exogenous ALA under normal conditions is crucial and may be the initial step for perception and signaling transmission, which then improves the ratio of GSH and AsA.
Abstract: Low temperature is a crucial factor influencing plant growth and development. The chlorophyll precursor, 5-aminolevulinic acid (ALA) is widely used to improve plant cold tolerance. However, the interaction between H2O2 and cellular redox signaling involved in ALA-induced resistance to low temperature stress in plants remains largely unknown. Here, the roles of ALA in perceiving and regulating low temperature-induced oxidative stress in tomato plants, together with the roles of H2O2 and cellular redox states, were characterized. Low concentrations (10–25 mg·L− 1) of ALA enhanced low temperature-induced oxidative stress tolerance of tomato seedlings. The most effective concentration was 25 mg·L− 1, which markedly increased the ratio of reduced glutathione and ascorbate (GSH and AsA), and enhanced the activities of superoxide dismutase, catalase, ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase. Furthermore, gene expression of respiratory burst oxidase homolog1 and H2O2 content were upregulated with ALA treatment under normal conditions. Treatment with exogenous H2O2, GSH, and AsA also induced plant tolerance to oxidative stress at low temperatures, while inhibition of GSH and AsA syntheses significantly decreased H2O2-induced oxidative stress tolerance. Meanwhile, scavenging or inhibition of H2O2 production weakened, but did not eliminate, GSH- or AsA- induced tomato plant tolerance to oxidative stress at low temperatures. Appropriate concentrations of ALA alleviated the low temperature-induced oxidative stress in tomato plants via an antioxidant system. The most effective concentration was 25 mg·L− 1. The results showed that H2O2 induced by exogenous ALA under normal conditions is crucial and may be the initial step for perception and signaling transmission, which then improves the ratio of GSH and AsA. GSH and AsA may then interact with H2O2 signaling, resulting in enhanced antioxidant capacity in tomato plants at low temperatures.
TL;DR: In this paper, the effect of Zn deficiency on red cabbage (Brassica oleracea l. var. capitata f. rubra) was studied under controlled environmental conditions.
Abstract: The effect of Zn deficiency was studied in red cabbage (Brassica oleracea l. var. capitata f. rubra) plants grown in nutrient solution under controlled environmental conditions. Zinc starvation affected the number (61%), surface area (72%) and biomass (62%) of leaves more than root biomass (42%). although chlorophyll fluorescence parameters revealed occurrence of photoinhibition following declined stomatal conductance and reduction of Co2 available at carboxylation sites, photosynthesis apparatus was not damaged seriously under Zn deficiency conditions. Chlorophyll a, chlorophyll a/b ratio, soluble carbohydrates and starch declined but anthocyanins and free phenolics were accumulated under Zn deficiency conditions. activity of ascorbate peroxidase, catalase and peroxidase enhanced under Zn deficiency conditions, whereas activity of superoxide dismutase declined in leaves but not in roots of Zn-deficient plants. Maintenance of superoxide dismutase activity and malondialdehyde content in roots demonstrated that roots were more protected against reactive oxygen species imbalance under Zn deficiency conditions compared with leaves that was correlated well with the lower sensitivity of roots to low Zn supply.