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Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands, primarily due to insufficient water resources and inadequate irrigation facilities. Consequently, combined salinity-drought stress poses a major threat to rice production. In this study, two salinity levels (NS, non-salinity; HS, high salinity) along with three drought treatments (CC, control condition; DJ, drought stress imposed at jointing; DH, drought stress imposed at heading) were performed to investigate their combined influences on leaf photosynthetic characteristics, biomass accumulation, and rice yield formation. Salinity, drought, and their combination led to a shortened growth period from heading to maturity, resulting in a reduced overall growth duration. Grain yield was reduced under both salinity and drought stress, with a more substantial reduction under the combined salinity-drought stress. The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing. Additionally, the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity, as well as in shoot biomass and nonstructural carbohydrate (NSC) content in the stem at heading and maturity. However, it increased the harvest index and NSC remobilization reserve. Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates, transpiration rates, and stomatal conductance. These reductions were more pronounced under the combined stress. Salinity, drought, and especially their combination, decreased the activities of ascorbate peroxidase, catalase, and superoxide dismutase, while increasing the contents of malondialdehyde, hydrogen peroxide, and superoxide radical. Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress. The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities, inhibited leaf photosynthetic functions, accelerated leaf senescence, and subsequently lowered assimilate accumulation and grain yield. [ABSTRACT FROM AUTHOR]

Microplastics (MPs), which are widely dispersed in terrestrial environments, threaten crop growth and human food security. However, plant accumulation and phytotoxicity related to the size effects of MPs remain insufficiently explored. This study investigated the accumulation and toxicity of two sizes of MPs on Capsicum annuum Linn. (C. annuum) through fluorescence tracing and antioxidant defense system assessment. The results revealed that the size of MPs significantly impacts their accumulation characteristics in C. annuum roots, leading to variations in toxic mechanisms, including oxidative stress and damage. Smaller MPs and higher exposure concentrations result in more pronounced growth inhibition. C. annuum roots have a critical size threshold for the absorption of MPs of approximately 1.2 μm. MPs that enter the root tissue exhibit an aggregated form, with smaller-sized MPs displaying a greater degree of aggregation. MP exposure induces oxidative stress in root tissues, with high concentrations of smaller MPs causing lipid peroxidation. Analysis of the IBR values revealed that C. annuum roots utilize ascorbic acid (ASA) to prevent oxidative damage caused by larger MPs. Conversely, smaller MPs primarily induce superoxide dismutase (SOD) and glutathione (GSH). These results emphasize the significant impact of MP size on plant antioxidant defense response mechanisms, laying the foundation for further investigating the implications for human health. [Display omitted] • Microplastics (MPs) can reduce the height and fresh weight of Capsicum annuum Linn. (C. annuum). • The critical size of MPs entering the roots of C. annuum is approximately 1.2 μm. • In C. annuum roots, smaller MPs are more prone to aggregation. • Small and large MPs induce distinct oxidative stress response mechanisms. [ABSTRACT FROM AUTHOR]

Contamination of agricultural soils with heavy metals (HMs) has posed major threat to the environment as well as human health. The aim of this study was to appraise the efficiency of key-antioxidant enzymes in enhancing plants' tolerance to HMs (heavy metals) like copper (Cu) and Cadmium (Cd), under the action of methyl jasmonate (Me-JA) in Cajanus cajan L. Seeds of C. cajan treated with Me-JA (0, 1 nM) were discretely subjected to noxious concentrations of Cu and Cd (0, 1, 5 mM) and raised for 12 days under controlled conditions in plant growth chamber for biochemical analysis. In contrast to Cd, Cu triggered oxidative stress more significantly (44.54% in 5 mM Cu increase in MDA as compared to control) and prominently thereby affecting plants' physiological and biochemical attributes. By activating the antioxidant machinery, Me-JA pre-treatment reduced HMs-induced oxidative stress, increased proline production, glutathione (41.95% under 5 mM Cu when treated with 1 nM Me-JA treatment) and ascorbic acid content by 160.4 % under aforemtioned treatments thus improving the redox status. Thus, in light of this our results put forward a firm basis of the positive role that Me-JA might play in the mitigation of oxidative stress caused due to HMs stress by stimulating antioxidant defense system leading to overall improvement of growth of C. cajan seedlings. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to investigate the effect of cerebral palsy and dental caries on dental plaque index, salivary parameters and oxidative stress in children and adolescents. Methods: Seventy children and adolescents aged 2–20 years were divided into four groups: neurotypical controls-inactive caries (NCIC; n = 19); neurotypical controls-active caries (NCAC; n = 16); cerebral palsy-inactive caries (CPIC; n = 19); and cerebral palsy-active caries (CPAC; n = 16). The visible dental plaque index was determined after drying the tooth surfaces and without any mechanical or chemical disclosing methods. Salivary pH and buffer capacity were measured 1 hour after collection using a digital pH meter. Saliva was used to evaluate oxidative status based on the levels of reactive species, lipid peroxidation and non-enzymatic antioxidants (reduced glutathione and vitamin C). Results: The CPIC and CPAC groups had lower salivary pH and a higher visible dental plaque index. CP was also associated with an increase in salivary levels of markers of oxidative stress and the modulation of salivary levels of non-enzymatic antioxidants. Conclusion: Cerebral palsy exerts an influence on the salivary profile, oral health and oxidative stress. The individuals with CP had more acidic saliva and a higher dental plaque index, which were positively correlated with caries activity. CP was associated with high salivary levels of reactive species and lipid peroxidation, demonstrating an imbalance in salivary redox that was particularly associated with caries activity. These factors facilitate the development of oral diseases in individuals with cerebral palsy. [ABSTRACT FROM AUTHOR]

This study investigated the antioxidant defense system involved in the tolerance of soybean (Glycine max) to aluminum (Al) stress. Physiological assays showed that the amount of superoxide free radicals (O2−), hydrogen peroxide (H2O2), and malondialdehyde (MDA) were significantly lower in an Al-resistant soybean cultivar (cv. PI416937) than in an Al-sensitive soybean cultivar (cv. Huachun18). Comparative analysis of microarray data from both genotypes following Al-stress treatment revealed that the expression of a series of antioxidant enzymes genes was induced in the Al-resistant cultivar. The quantitative real time-PCR (qRT-PCR) assay showed that the transcript levels of genes encoding antioxidant enzymes, including GmCAT1, GmPOD1, GmGST1, GmAPX, GmGSH1, and GmSOD, were higher in the Al-resistant cultivar than in the Al-sensitive cultivar in Al-stress conditions. Furthermore, GmCAT1-overexpressing Arabidopsis plants had improved tolerance to Al-stress and lower O2−, H2O2, and MDA contents than wild-type plants. Therefore, providing evidence that the antioxidant defense system is essential for Al tolerance in soybean. Al: aluminum; O2−: superoxide free radicals; ROS: reactive oxygen species; H2O2: hydrogen peroxide; MDA: malondialdehyde; qRT-PCR: quantitative reverse transcription polymerase chain reaction; GO: gene ontology; WT: wild type; MS medium: Murashige and Skoog medium Antioxidant defense system play essential roles in soybean Al tolerance. The results are of great significance in understanding the molecular mechanism of Al stress responses in soybean. [ABSTRACT FROM AUTHOR]

Cadmium tellurium quantum dots (CdTe QDs) as one of the most widely used QDs have been reported the toxicity and biosafety in recent years, little work has been done to reduce their toxicity however. Based on the mechanisms of toxicity of CdTe QDs on liver target organs such as oxidative stress and apoptosis previously reported by other researchers, we investigated the mechanism of action of trace element selenium (Se) to mitigate the hepatotoxicity of CdTe QDs. The experimental results showed that Se-Met at 40–140 μg L−1 could enhance the function of intracellular antioxidant defense system and the molecular structure of related antioxidant enzymes by reduce the production of ROS by 45%, protecting the activity of antioxidants and up-regulating the expression of selenoproteins with antioxidant functions, Gpx1 increase 225% and Gpx4 upregulated 47%. In addition, Se-Met could alleviate CdTe QDs-induced apoptosis by regulating two apoptosis-inducing factors, as intracellular caspase 3/9 expression levels were reduced by 70% and 87%, decreased Ca2+ concentration, and increased mitochondrial membrane potential measurements. Overall, this study indicates that Se-Met has a significant protective effect on the hepatotoxicity of CdTe QDs. Se-Met can be applied to the preparation of CdTe QDs to inhibit its toxicity and break the application limitation. [Display omitted] ● Combining cellular and molecular levels to study the role and regulation mechanism of Se-Met in adverse effects induced by CdTe QDs. ● Se-Met maintains redox balance and mitochondrial function by protecting the structural changes of SOD/CAT and enhancing the antioxidant function of selenoproteins, reduces the level of apoptosis induced by CdTe QDs, and attenuates the toxicity of CdTe QDs on hepatocytes. [ABSTRACT FROM AUTHOR]

The present study deals with impact of varied doses of arsenite (As III ; 50, 100 and 150 µM) and arsenate (As V ; 50, 100 and 150 mM) on growth, photosynthetic pigments, photochemistry of photosystem II, oxidative biomarkers, (O 2 • ¯, H 2 O 2 and MDA equivalents contents) and activity of antioxidant enzymes in diazotrophic cyanobacterium Nostoc muscorum after 48 and 96 h of the treatments. The reduction in growth, pigment contents (Chl a , Phy and Car) and PS II photochemistry was found to increase with enhanced accumulation of test metal in cells, and the damaging effect on photosynthetic pigments showed the order (Phy > chl a > Car). The negative effect on PS II photochemistry was due to significant decrease in the value of JIP kinetics ϕP 0 , F V /F 0 , ϕE 0 ,Ψ 0 and PI ABS except F 0 /F V and significant rise in values of energy flux parameters such as ABS/RC, TR 0 /RC, ET 0 /RC and DI 0 /RC. Both the species of arsenic caused significant rise in oxidative biomarkers as evident by in vitro and in vivo analysis of (O 2 • ¯, H 2 O 2 and MDA equivalents contents) despite of appreciable rise in the activity antioxidative enzymes such as SOD, POD, CAT and GST. The study concludes that in among both forms of arsenic, arsenite effect was more dominant on growth, photosynthetic pigments; oxidative stress biomarkers as evident by weak induction of anti-oxidative defense system to overcome the stress as compared to arsenate. [ABSTRACT FROM AUTHOR]

During its life cycle, plant has to cope with a number of abiotic stresses including cadmium stress. Cadmium (Cd) is highly toxic to plant and greatly influences its growth and entire metabolism. Antioxidants have to enable plant to beat such stresses. Therefore, effects of ascorbate (AsA), proline (Pro) and glutathione (GSH) applied, as seed soaking solutions, singly or in a sequence on cucumber transplant growth, physio-biochemical attributes and antioxidant defense system activity were investigated under 2 mM Cd stress. Adding Cd to transplants in irrigation water reduced photosynthetic efficiency, and nutrient (K + and Ca 2+ ) contents, while increased the activity of defense systems (non-enzymatic and enzymatic antioxidants) and Cd 2+ contents in roots and leaves. Exogenous AsA, Pro and GSH applied singly or in a sequence improved transplant growth (e.g., shoot length, leaf area, shoot fresh weight and shoot dry weight), photosynthetic efficiency (i.e., SPAD chlorophyll, Fv/Fm and PI), transplant health (i.e., increased leaf MSI and RWC, and decreased root and leaf Cd 2+ contents), antioxidant defense systems activity (enzymatic; superoxide dismutase, catalase, glutathione reductase and ascorbate peroxidase, and non-enzymatic; Pro, AsA and GSH antioxidants) and nutrient (K + and Ca 2+ ) contents. These positive results were obtained under irrigation with or without Cd, AsA. Sequenced AsA-Pro-GSH was the best treatment of which this study recommends to use, followed by GSH treatment, for growing cucumber transplants under Cd stress. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is known to have detrimental effects on plant growth and human health. Recent studies showed that silicon nanoparticles (SNPs) can decrease Cd toxicity in plants. Therefore, a study was conducted using 50 μM Cd and 1.50 mM SNPs to investigate Cd uptake, subcellular distribution, proline (Pro) metabolism, and the antioxidant defense system in rapeseed seedlings. In this study, results indicated that Cd stress negatively affected rapeseed growth, and high Cd contents accumulated in both shoots and roots. However, SNPs significantly decreased Cd contents in shoots and roots. Moreover, substantial increases were found in root fresh weight by 40.6% and dry weight by 46.6%, as well as shoot fresh weight by 60.1% and dry weight by 113.7% with the addition of SNPs. Furthermore, the addition of SNPs alleviated oxidative injury by maintaining the ascorbate-glutathione (AsA-GSH) cycle and increased Pro biosynthesis which could be due to high activities of Δ1-pyrroline-5-carboxylate synthase (P5CS) and reductase (P5CR) and decreased proline dehydrogenase (ProDH) activity. Furthermore, the addition of SNPs accumulated Cd in the soluble fraction (42%) and cell wall (45%). Results indicate that SNPs effectively reduce Cd toxicity in rapeseed seedlings which may be effective in promoting both rapeseed productivity and human health preservation. [Display omitted] • The influence of nano-silicon on Cd-stressed rapeseed seedlings was investigated • Silicon nanoparticle alleviated Cd-induced phytotoxicity by regulation of proline contents • Silicon nanoparticle regulated the activities of enzymes that are involved in the AsA-GSH • Silicon nanoparticle helped to fix Cd on the cell wall of rapeseed [ABSTRACT FROM AUTHOR]

Living organisms are continuously exposed to reactive oxygen species (ROS) during their lifespan. Small amounts of ROS can act as signal transduction molecules. However, excess ROS cause oxidative stress resulting in multiple adverse effects such as protein and lipid oxidation as well as DNA damage. Cells have developed an antioxidant defense system to maintain the balance between ROS production and scavenging, but imbalance often occurs leading to excess ROS. In this review, we summarized cellular redox reactions and their detection as well as cellular based assays that are used to measure and reflect the real case scenario of antioxidant potential of compounds of interest. Multiple cellular assays developed to evaluate the cellular levels of ROS and antioxidant activity were also reviewed. These studies lead to better understanding of redox homeostasis and identification of more natural antioxidant products that benefit human health. [ABSTRACT FROM AUTHOR]

Chitosan (CTS) induces plant tolerance against several abiotic stresses, including salinity and drought exposure. However, the role of CTS in cadmium (Cd)-induced stress amelioration is largely unknown. In the present study, a hydroponic pot experiment was conducted to study the roles of CTS with different molecular weight (Mw) (10 kDa，5 kDa and 1 kDa) in alleviating Cd toxicity in edible rape ( Brassica rapa L .). The results showed that Cd stress significantly decreased plant growth, leaf chlorophyll contents and increased the malondialdehyde (MDA) level in rape leaves. Foliar application of CTS promoted the plant growth and leaf chlorophyll contents, and decreased the malondialdehyde (MDA) level in edible rape leaves under Cd stress. The alleviation effect of CTS on toxicity was depended on its Mw and CTS with Mw of 1 kDa showed the best activity. Spraying 1 kDa CTS onto the leaves of edible rape under Cd-toxicity could decrease shoot Cd 2+ concentration and improve photosynthetic characteristics of edible rape. Moreover, 1 kDa CTS also significantly enhanced non-enzymatic antioxidants (ascorbic acid) and enzyme activities (superoxide dismutase, catalase and guaiacol peroxidase) under Cd stress. Based on these findings, it can be concluded that application of exogenous CTS could be an effective approach to alleviate the harmful effects of Cd stress and could be explored in an agricultural production system. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the in vivo healing and possible protective effects of Ω-3 against acute Tributyltin (TBT) toxicity in different tissues of rats. TBT, a tin-containing organometallic antifouling compound, is known for its adverse effects on aquatic as well as terrestrial organisms. Five groups, with seven rats each, were used in the experiments. The groups were designed as: (I) normal control, (II) vehicle control, (III) TBT (5 mg/kg/day) (IV) Ω-3 (250 mg/kg/day), and (V) TBT+Ω-3 (5 mg/kg/day + 250 mg/kg/day). Liver, kidney, spleen, and gonad tissues were assessed for their superoxide dismutase, glutathione peroxidase (GPx), glutathione reductase, and glutathione Stransferase activity levels, and changes in the glutathione (GSH) and malondialdehyde (MDA) levels, as well as serum biochemical parameters. TBT administration was found to alter the lactate dehydrogenase, total cholesterol, and low-density lipoprotein cholesterol significantly. MDA in the kidney showed a significant increase in the TBT administration compared to the control and vehicle, and a significant decrease in the Ω-3-administered groups. In the liver and spleen, the GPx showed a significantly low level of TBT compared to the control and vehicle, whereas it was significantly increased in the Ω-3 and TBT+ Ω-3 groups compared to the TBT group. As a result, TBT was found to cause an increase in the lipid peroxidation, a deterioration in the lipid profile and biochemical parameters, a decrease in the GSH, and a loss of antioxidant defense enzyme activity, whereas Ω-3 was found to ameliorate some of those hazardous impacts. [ABSTRACT FROM AUTHOR]

The effects of salinity stress on growth parameters and the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), glutathione reductase (GR), and ascorbate peroxidase (APX)) were investigated in Arabidopsis thaliana during Phelipanche ramosa mediated biotic stress. The experiment was conducted using 100 mM NaCl on infected 18-dayold A. thaliana plants in Gamborg B5 medium. P. ramosa infection reduced root length and shoot dry weight (DW) in A. thaliana. After salt stress treatment shoot fresh weight (FW) decreased in A. thaliana plants infected with P. ramosa. Salt stress treatment produced a significant reduction in carotenoid and total chlorophyll content while it did not change the chl a/b ratio of infected plants. POX and APX activities increased during P. ramosa infection in A. thaliana. Additional NaCl treatment decreased the level of lipid peroxidation accompanied by an increment in SOD, POX, GR, CAT and APX activities, while chl a/b ratio and total chl content decreased. These results, presented for the first time, demonstrated induction of the antioxidant defense system against P. ramosa infection by NaCl treatment in A. thaliana. [ABSTRACT FROM AUTHOR]

Background: Diabetes and hypertension are diseases that often coexist, which increases the risk of chronic organ damages and cardiovascular complications.Purpose: To evaluate the effects of saponarin, isolated from Gypsophila trichotoma Wend, on blood pressure, glycemia, body weight, and liver biochemical parameters related to oxidative stress in diabetic normotensive Wistar Kyoto rats (NTR) and spontaneously hypertensive rats (SHR).Methods: Diabetes was induced by administration of streptozotocin (40 mg/kg, i.p.). The following biochemical parameters: reduced glutathione (GSH), malondialdehyde (MDA), total cytochrome P450, aniline hydroxylase (AH) activity, as well as the activities of antioxidant enzymes such as glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) were measured in the livers of euthanized rats.Results: Saponarin exerted slight antihypertensive activity in non-diabetic SHR, judged by 19% (p<0.05) decrease of the initial blood pressure. However, such effect was not observed in streptozotocin-induced diabetic SHR (SHR-D). Streptozotocin-induced diabetes was evidenced by 78% (p<0.05) and by 171% (p<0.05) increase in blood glucose level in NTR and SHR, respectively. In non-diabetic SHR the initial MDA quantity was by 36% (p<0.05) higher and the initial GSH levels were by 28% (p<0.05) lower in comparison to non-diabetic NTR. Significant decrease in the activities of GPx, GR, and GST was measured in the livers of all diabetic rats. Treatment with saponarin ameliorated the above mentioned liver parameters in both diabetic strains, however its effects were less pronounced in the diabetic SHR group.Conclusion: Taken together our data indicate that diabetes and hypertension in combination are more difficult to be modulated by saponarin. [ABSTRACT FROM AUTHOR]

Pod filling stage considers as a receiver (sink), which reflects plant performance during previous growth stages. In order to study, the influence of drought imposed at different growth stages, and the impact of foliar applied glycine betaine (GB) and proline on the status of osmolytes and antioxidant defense system of pea plant during pod filling stage, a field experiment was conducted in 2012/2013 and 2013/2014 on clay loam soil. Four different irrigation regimes were applied to provide drought at different growth stages: (1) vegetative stage, (2) flowering stage, as short-term drought stress, (3) throughout the stages of vegetative + flowering growth (long-term drought stress), and (4) control (without stress). Foliar applications of GB and proline at 4 mM for each, in addition to distilled water as control, were conducted. Generally, drought applications reduced the growth and yield of pea plant. Long-term drought was more effective to reduce growth and yield than drought at flowering stage. GB increased the yield and its soluble protein concentration more than proline. Proline recorded the maximum increase in non-enzymatic antioxidant defense system under drought. Application of GB or proline enhanced the activity of SOD, APX and catalase in leaves under drought, while in seeds they increased SOD activity under long-term drought stress. APX activity in seeds under drought decreased by GB application. The maximum positive effect was for GB under unstressed condition and drought at vegetative stage, by maximizing APX activity, in addition to enhancing the production and translocation of assimilates from source to sink. [ABSTRACT FROM AUTHOR]

In this study fertilized eggs, and larvae of Chalcalburnus tarichi were exposed to bisphenol A, an endocrine-disrupting chemical, to determine its toxic effects. A semistatic test procedure was followed to investigate the effects of the bisphenol A at concentrations of 0.75, 1.50, 3.00, 6.00, 12.00, 24.00, and 48.00 mg/L. The 96 hours median lethal concentration level for the eggs was determined as 3.96 mg/L. The hatching rates of the control and bisphenol A-treated groups were 80.3%, 12.0%, 3.4%, 1.5%, 0.2%, 0.3%, 0.0%, and 0.0%, respectively. The 96 h median lethal concentration level for the larvae was determined as 3.52 mg/L. The observed deformities in the larvae included slowed heart rate and blood circulation, developmental arrest, regressed swim bladder formation, cardiac edema, lordosis, hemorrhage, organ hypertrophy, delayed yolk sac withdrawal, and regression in the pigmentation. On the other hand, effect of sublethal concentrations of bisphenol A on the antioxidant defense system in the larvae of Chalcalbumus tarichi was investigated until yolk sac withdrawal. The results revealed that the malondialdehyde content and glutathione reductase activity increased at 0.75 and 1.50 mg/L of bisphenol A and returned to the control levels at 3.00 mg/L. The superoxide dismutase activity and glutathione content was significantly reduced. The glutathione peroxidase activity was elevated only at 0.75 mg/L of bisphenol A. The glutathione- S-transferase activities and catalase activities did not alter. It was concluded that bisphenol A was a toxic substance for the fish fertilized eggs and larvae and changes antioxidant defense. [ABSTRACT FROM AUTHOR]

A broad-spectrum fungicide, dichlofluanid is widely used in antifouling paints and agricultural pesticides. In this study, the acute and chronic effects of sublethal concentrations, namely, no observable effect concentration (NOEC) and 50% lethal concentration (LC 50) of dichlofluanid (1/10 NOEC, NOEC, 1/10 LC 50 , and LC 50) were evaluated on the marine mysid, Neomysis awatschensis. Acute toxicity test (96 h) showed higher sensitivity to dichlofluanid in juvenile mysids (LC 50 3.1 μg L−1) than adults (LC 50 24.5 μg L−1), with lower survival rate and reduction in food consumption. Exposure with dichlofluanid considerably induced oxidative imbalance, as NOEC (0.006 μg L−1 for juveniles and 0.074 μg L−1 for adults) and 1/10 LC 50 values increased intracellular concentrations of malondialdehyde and glutathione, and the enzymatic activities of catalase and superoxide dismutase, whereas exposure to LC 50 value decreased the values of oxidative parameters. Enzymatic activity of acetylcholinesterase decreased considerably when exposed to LC 50 value. In the case of chronic effects, exposure to NOEC for 4 weeks markedly decreased the juvenile survival rate, while adults showed tolerance. Multigenerational monitoring in response to NOEC showed a significant growth retardation with an increase in intermolt duration as well as a decrease in the number of newborn mysids from females of the third generation. Consistent exposure to environmentally relevant sublethal concentrations of dichlofluanid would be detrimental to mysid individuals and the survival of the mysid population. [Display omitted] • Dichlofluanid toxicity, for the first time, was evaluated on mysid crustaceans at a multigenerational level. • Dichlofluanid induced oxidative stress with age-specific decrease in survival and food consumption. • Dichlofluanid reduced the antioxidant defense ability and cholinergic response of mysid. • Higher concentrations directly affected mysid growth, molting, and fecundity. • Even sublethal concentrations significantly modulated mysid population when they were exposed consistently. [ABSTRACT FROM AUTHOR]

Summary: Objective: In this study we investigated the effect of peritoneal dialysis (PD) on some antioxidant markers and lipid peroxidation. Methods: The levels of malondialdehyde (MDA), erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), vitamins A, E, and C, and total antioxidant capacity (TAC) were determined in 23 chronic ambulatory PD patients and 34 healthy controls. Results: The results showed MDA level in patients were not significantly different from those in controls. Erythrocyte SOD and GPX activities and vitamin C level were significantly decreased in the chronic ambulatory PD group (p < 0.0001), while the levels of TAC (p < 0.01), uric acid, and vitamins A (p < 0.0001) and E (p > 0.05) were enhanced with respect to the control group. Conclusions: The findings suggest that despite slightly increased MDA level, patients on PD are exposed to oxidative stress, as evidenced by the decreased levels of SOD, GPx, and vitamin C. Depletion of these antioxidants may contribute to accelerated atherogenesis in these patients. [Copyright &y& Elsevier]

Abstract: Changes in activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and non-enzymatic antioxidant reduced glutathione (GSH) content and levels of Lipid peroxidation (LPO) in gill, liver, brain and intestine of juvenile carp (Cyprinus carpio) were evaluated after exposure to different concentrations (0.5, 5.0 and 50.0mg/L) of waterborne nano-ZnO for 1, 3, 7, 10 and 14 day. The results showed that the variation trendency of antioxidant defense systems and LPO levels would be more significant with increasing concentration and exposure time. 50.0mg/L nano-ZnO caused significant decrease of several enzymes activities and GSH content and increase of LPO level. As a result, these biomarkers were all appropriate for monitoring oxidative stress status of fish after exposure to nano-ZnO. Gill, liver and brain might be more sensitive response organs, being intestine the least altered organ. Further ecotoxicological evaluation should be made concerning the risk of nano-ZnO on aquatic environment. [Copyright &y& Elsevier]

A pot experiment was carried out to investigate the effect of exogenous salicylic acid (SA) on the growth, photosynthesis, oxidative stress and responses of chloroplastic antioxidant defense system of maize (Zea mays L.) plants grown in a nickel (Ni)-contaminated soil. The results indicate that exogenous SA significantly decreased the reduction in dry weight, chlorophyll and ¿-carotene contents, and net photosynthetic rate of the Ni-stressed maize, demonstrating an alleviating effect of SA on Ni toxicity of plants. Superoxide anion generation rate, H2O2 and malondialdehyde (MDA) contents, and lipoxygenase (LOX, EC 1.13.11.12) activity significantly increased in the chloroplasts of maize exposed to Ni stress, revealing an oxidative damage occurred in maize chloroplasts, whereas, the values of these parameters were markedly lowered in the SA-treated plants under Ni stress. Application of SA significantly enhanced the activities of superoxide dismutase (SOD, EC 1.15.1.1), 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), and the poll of reduced ascorbate and glutathione in chloroplasts of the Ni-stressed maize. Accordingly, the fact that SA up-regulates the capacity of antioxidant defense system in chloroplasts, thus reducing the oxidative damage, is involved in the SA-induced alleviation of Ni toxicity in maize. [Copyright &y& Elsevier]

In this study, the effects of dichlorvos (DIC) at sublethal concentration on malondialdehyde (MDA) content and antioxidant defense system (ADS) such as reduced glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), and glutathione-S-transferase (GST) in various tissues of rats exposed to 0.0225 and 0.0450 millimole (mmol) DIC in drinking water were administered orally to rats ad libitum for 28 days continuously. MDA significantly increased in all the tissues except in the lungs of rats treated with both dosages of DIC. With regard to the ADS, GR significantly decreased in the erythrocytes whereas it did not change in the other tissues with two dosages of DIC. SOD activity significantly increased in the all tissues treated with both dosages of DIC. GST activity significantly increased in all the tissues except in the erythrocytes, spleen, and lungs treated with 0.0225mmol. Meanwhile, GSH depletion in the liver and heart of rats treated with 0.0225mmol and all the tissues except in the brain and kidney of rats treated with 0.0450mmol of DIC were found to be significant. The observations presented led us to conclude that the administrations of DIC promote MDA content and fluctuate in the ADS in rats during the exposure. [Copyright &y& Elsevier]

The effects of selenium (Se) on antioxidant defense system in liver and kidneys of rats with cadmium (Cd)-induced toxicity were examined. Cd exposure (15 mg Cd/kg b.m./day as CdCl2 for 4 weeks) resulted in increased lipid peroxidation (LP) in both organs (p<0.005 and p<0.01). Vitamin C (Vit C) was decreased in the liver (p<0.005), whereas vitamin E (Vit E) was increased in the liver and kidneys (p<0.005 and p<0.05) of Cd-exposed animals. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were decreased in both tissues (p<0.05 and p<0.005), whereas catalase (CAT) activity was decreased only in liver (p<0.005). Glutathione S-transferase (GST) increased in both tissues (p<0.005 and p<0.01). Treatment with Se (0.5 mg Se/kg b.m./day as Na2SeO3 for 4 weeks) significantly increased liver and kidneys SOD and GSH-Px activities (p<0.05 to p<0.005), as well as CAT and GST activities only in the liver (p<0.01). In animals exposed to Se, both the concentrations of Vit C (p<0.01) and Vit E (p<0.005) were increased in both tissues. Co-treatment with Se resulted in reversal of oxidative stress with significant decline in analyzed tissues Cd burden. Our results show that Se may ameliorate Cd-induced oxidative stress by decreasing LP and altering antioxidant defense system in rat liver and kidneys and that Se demonstrates the protective effect from cadmium-induced oxidative damage. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to assess the effects of subchronic exposure to cadmium (Cd) on the antioxidant defense system of red blood cells (RBCs) and lipid peroxide concentration in the plasma, as well as the possible protective role of zinc (Zn). For this purpose, 60 male Wistar rats (8 weeks old) were divided into three groups: the first group was exposed to Cd in the form of CdCl2, administered in five doses (each of 0.4mg Cd/kg BW) on days 5, 10, 15, 20 and 25, giving a total dose of 2mg Cd/kg BW, i.p.; the second group was simultaneously exposed to Zn and Cd with the same timeline and the same doses of Cd as the first group but with, in addition, injections of Zn in the form of ZnCl2, administered in doses of 0.8mg Zn/kg BW, giving a total dose of 4mg Zn/kg BW, i.p.; a control group received 0.5mL of physiological saline in an identical manner. It was shown that exposure to Cd induced a significant decrease (p<0.05) in superoxide dismutase (Zn/Cu SOD) and catalase (CAT) activities in RBCs. Increased lipid peroxide concentration, measured by thiobarbituric acid reactive substances (TBARS), was also observed in the plasma of cadmium-exposed rats. Cd had no effect on glutathione peroxidase (GSH-Px) activity. Zn administration had a beneficial effect on the Cd-induced decrease in Zn/Cu SOD activity (p<0.05) but not on CAT activity. Animals receiving Cd and Zn simultaneously had significantly (p<0.05) lower concentrations of lipid peroxides than rats exposed to Cd alone. Our results indicate that Cd causes oxidative stress and that Zn supply in conditions of exposure to Cd can partially protect against Cd-induced oxidative stress. [Copyright &y& Elsevier]

Abstract: Copper bioavailability in the tissues of goldfish and antioxidant defenses in the liver of fish were investigated in vivo following 40 days of exposure to different species of copper solutions at different concentrations. Copper seemed to be more concentrated in the gill than in the liver after Cu2+ and copper-ethylenediaminetetraacetate (Cu–EDTA) exposure. The addition of EDTA markedly affected copper adsorption in the gill but had no significant effects in the liver. We also found that in the fish exposed to the concentration of Cu2+ below the Chinese national fishery water quality standard of 0.01mg/L, superoxide dismutase (SOD) and glutathione S-transferase (GST) activities in liver were stimulated and catalase (CAT) and Se-dependent glutathione peroxidase (Se-GPx) activities were inhibited after 40 days of exposure. Compared to copper exposure, the addition of EDTA did not affect SOD and GST significantly. However, CAT and GPx activity with Cu2+ exposure were significantly different from those with Cu–EDTA exposure. [Copyright &y& Elsevier]

Larval goldfish Carassius auratus were exposed to 0.05 and 0.1 mg/L No. 20 diesel oil, widely used as transportation power in China, for 2, 4, 7, 10, 15, 25, and 40 days, while one control group was designated for each exposure group. Some fish after 25 days of exposure were transferred to diluted water until the 40th day. Hepatic antioxidant defense parameters of fish, including contents of reduced glutathione and glutathione disulfide and activities of superoxide dismutase, catalase, glutathione reductase, selenium-dependent glutathione peroxidase, and glutathione S-transferase, were determined and compared to control values. All the results indicated that the antioxidant responses of the fish to the two concentrations of oil exposure were similar on the whole. The possible defense mechanisms of fish and prospective early biomarkers for the evaluation of an oil-dominant contaminated aquatic ecosystem are discussed. In addition, after fish were removed from oil exposure, the recovery status of these antioxidant indices was explored. [Copyright &y& Elsevier]

Multi-walled carbon nanotubes (MWCNTs) have recently attracted huge attention to their impacts on the environment and plants. Therefore, this experiment was conducted to investigate the responses of lead (Pb) and cadmium (Cd) exposed pot marigold plants to various levels of MWCNT. Calendula officinalis (L.) seedlings were cultivated in Pb and Cd-polluted soils with exposure to 0, 50, 100, 250, 500 and 1000 mg L−1 of MWCNT. The results demonstrated that foliar-applied MWCNT up to 250 mg L−1 not only alleviated Pb and Cd-induced toxicity by reducing oxidative damage and boosting both enzymatic and non-enzymatic antioxidant defense system but also promoted the phytoremediation property of pot marigold plants by enhancing the accumulation of both Pb and Cd from the soil. Interestingly, oxidative damage exacerbation and both Pb and Cd accumulation reduction were noticed in pot marigold seedlings exposed to 500 and 1000 mg L−1 MWCNTs. The findings of this study clearly showed that the use of appropriate concentrations of MWCNTs in increasing the phytoremediation properties of pot marigold was justified, while the use of high concentrations is toxic to the plant and intensifies the toxic effects of heavy metals (HMs) on plant physiology. This study provides a novel method to facilitate the phytoremediation of HMs polluted soils using MWCNT as well as explores the potential risks of these nanoparticles to the plants. • The foliar-application of MWCNT alleviated Pb and Cd-induced toxicity. • MWCNTs reduced oxidative damage and boosted antioxidant defense system. • The lower doses of MWCNTs could be used for increasing phytoremediation properties to Calendula officinalis (L.). [ABSTRACT FROM AUTHOR]

Aquatic ecosystem health is the main concern to increasing pesticides application to control agricultural pests as it is the ultimate receptor of such materials. This study evaluated the impact of new metal-insecticide, the [Mg(hesp) 2 (phen)], referred as MgHP, on fish using physiological, genetic, biochemical, and morphological biomarkers. The fish, Prochilodus lineatus , was exposed to 0 (control), 1, 10, 100, 1000 μg L−1 MgHP, for 24 and 96 h. MgHP was not lethal but caused genotoxicity, altered hematological variables and, the activity of antioxidant and biotransformation enzymes and histology of liver, depending on concentration and time exposure. Hematocrit and erythrocyte number (RBC) increased without change hemoglobin content resulting in changes in hematimetric indexes after 24 h; after 96 h, only RBC was changed. Erythrocyte nuclear abnormalities and crenate cells increased after 24 h but, not after 96 h. Erythrocytes and hepatocytes indicated instability in DNA integrity however, the absence of micronuclei suggested DNA damage repairment. After 24 h, the antioxidant defense system and the phase II biotransformation enzyme was responsiveness and catalase activity decreased at high MgHP concentrations; the antioxidant response was triggered after 96 h. Hepatocyte hypertrophy, intracellular cytoplasmic substances, cytoplasm degeneration, melanomacrophage and hyperemia increased in fish exposed from 10 μg L−1 to higher MgHP concentrations; the organ alteration index increased as MgHP concentration increased showing dose-dependence. Most of hematological and genotoxic effects occurred after 24 h exposure evidencing potential recover capability of organism by activation of the antioxidant defense system and DNA repairment mechanisms. Nevertheless, the histopathological changes in the liver was maintained over time at high MgHP concentrations, a concentration usually no environmental relevant. In conclusion, this data reinforced the importance of continuing research on MgHP effects in other organisms considering the promising use of such compound to control the leaf-cutter ants and other insects. Image 1 • The flavonoid based metal-insecticide MgHP at high levels affect fish health status. • Erythrocytes and hepatocytes showed DNA instability at 24 and 96 h exposure. • Hematological changes and genotoxicity evidenced potential recover capability. • CAT activity was inhibited after 24 h and stimulated after 96 h. • Liver morphological changes was maintained over time at high MgHP concentrations. [ABSTRACT FROM AUTHOR]

The flavonoid metal-insecticide [Mg(hesp) 2 (phen)], denominated MgHP, has high potential for controlling agricultural pests. If applied in large scale, it may reach aquatic ecosystems and be harmful to the biota. This study evaluated the effects of MgHP in the gills of the Neotropical fish, Prochilodus lineatus by determining the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione s-transferase (GST), and the levels of glutathione (GSH) and lipid peroxidation (LPO) after 24 and 96 h exposure to 0, 1, 10, 100 and 1000 μg L−1. The histopathological changes with emphases to mitochondria-rich cells (MRC) were evaluated as well. After 24 h exposure the enzyme activities and the GSH and LPO levels were unchanged however, after 96 h exposure to high MgHP concentration (1000 μg L−1), the GST activity and GSH levels increased. Oxidative stress measured as LPO levels did not occur after MgHP exposure in both periods. Gill tissue alterations increased after MgHP exposure to 10, 100 and 1000 μg L−1. Cellular atrophy, pillar cells changes, filament epithelium hyperplasia and hypertrophy, lamellar epithelium hyperplasia were the most frequent histopathology. MRC in the filament epithelium decreased after exposure to 24 h and increased after 96 h indicating possible transitory osmo-ionic disruption. P. lineatus exhibited high tolerance to MgHP. The increased GST activity and GSH levels after 96 h exposure suggested possible MgHP accumulation and concentration- and time-dependent response. Histopathology in the gills of exposed fish occurred at high MgHP concentrations. These results suggested that the MgHP into water, at high concentrations, affect the gills by changing GST activity, GSH levels and histology being useful biomarkers for MgHP water contamination. • The metal-insecticide [Mg(hesp) 2 (phen)], the MgHP, induces changes in fish gills. • Glutathione-S-transferase and glutathione increased after exposure (96 h) to MgHP. • Lipid peroxidation unchanged after 24 and 96 h exposure to MgHP. • Mitochondria-rich cells decreased and increased after 24 and 96 h MgHP exposure. • Gill histopathology exhibited time- and dose-dependence response to MgHP exposure. [ABSTRACT FROM AUTHOR]

This paper reports the role of exogenous glycine betaine (25 and 50 mM GB at a rate of 50 mL per plant) in enhancing NaCl-stress tolerance in common bean (Phaseolus vulgaris L.). Irrigating plants by simulated saline water, containing 0, 50 and 100 mM sodium chloride (NaCl), significantly reduced the growth dynamics, photosynthetic pigments (i.e., Chl a, Chl b, and carotenoids), membrane stability index (MSI), relative water content (RWC), and pod yield. While, malondialdehyde (MDA), endogenous proline, and glutathione contents, electrolyte leakage (EL), antioxidant defense system, and Na+ accumulation markedly increased upon exposure to NaCl-stress. However, the application of exogenous GB significantly improved salt tolerance of common bean as it increased the antioxidant defense including both enzymatic (i.e., peroxidase, superoxide dismutase, and catalase) and nonenzymatic (i.e., proline and glutathione) agents. Consequently, MSI, RWC, EL, and photosynthetic pigments have been improved recording significantly higher values than the control. Moreover, the pod yield increased by 29.8 and 59.4% when plants grown under 50 and 100 mM NaCl, respectively, were sprayed with 25 mM GB. Our results show that GB-induced slat tolerance in common bean plants mainly depends on the osmoregulation effect of GB and to a lesser extent on its antioxidant capacity. Foliar application of GB significantly reduced the accumulation of Na+ and at the same time induced K+ uptake maintaining a higher K+/Na+ ratio. Despite some changes in the activities of antioxidant enzymes induced by the application of GB, no consistent contribution in the salt tolerance could be cited in this study. Therefore, we suggest that salt tolerance is largely unrelated to the antioxidant defense ability of GB in common bean. While the potential role of GB in ameliorating salt tolerance is mainly due to the adjustment of ions uptake through limiting Na+ uptake and alternatively increasing K+ accumulation in plant tissues. • NaCl stress adversely affects the growth and development of common bean. • NaCl stress reduces RWC, MSI, photosynthetic pigments, and yield. • NaCl stress increased activity of CAT, POD, and SOD and proline and glutathione content. • Foliar application of glycine betaine induces salt tolerance through osmoregulation and antioxidant defense properties. • Glycine betaine mainly limits Na+ uptake and alternatively increases K+ accumulation. [ABSTRACT FROM AUTHOR]

Metalaxyl is a broad-spectrum chiral fungicide that used for the protection of plants, however extensive use of metalaxyl resulted in serious environmental problems. Thus, a study on the detoxification mechanism in algae/cyanobacteria and their ability for phycoremediation is highly recommended. Here, we investigated the physiological and biochemical responses of two cyanobacterial species; Anabaena laxa and Nostoc muscorum to R -metalaxyl toxicity as well as their ability as phycoremediators. Two different levels of R- metalaxyl, at mild (10 mg/L) and high dose (25 mg/L), were applied for one-week. We found that A. laxa absorbed and accumulated more intracellular R- metalaxyl compared to N. muscorum. R- metalaxyl, which triggered a dose-based reduction in cell growth, photosynthetic pigment content, and photosynthetic key enzymes' activities i.e. , phosphoenolpyruvate carboxylase (PEPC) and ribulose‒1,5‒bisphosphate carboxylase/oxygenase (RuBisCo). These decreases were significantly less pronounced in A. laxa. On the other hand, R -metalaxyl significantly induced oxidative damage markers, e.g. , H 2 O 2 levels, lipid peroxidation (MDA), protein oxidation and NADPH oxidase activity. However, these increases were also lower in A. laxa compared to N. muscorum. To alleviate R -metalaxyl toxicity, A. laxa induced the polyphenols, flavonoids, tocopherols and glutathione (GSH) levels as well as peroxidase (POX), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-s-transferase (GST) enzyme activities. On the contrary, the significant induction of antioxidants in N. muscorum was restricted to ascorbate, catalase (CAT) and ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) enzyme activities. Although A. laxa accumulated more R- metalaxyl, it experienced less stress due to subsequent induction of antioxidants. Therefore, A. laxa may be a promising R- metalaxyl phycoremediator. Our results provided basic data for understanding the ecotoxicology of R -metalaxyl contamination in aquatic habitats and the toxicity indices among cyanobacteria. Image 1 • R- metalaxyl-induced toxicity in cyanobacteria was a function of dose and species type. • Although Anabaena laxa accumulated R- metalaxyl, it experienced less stress than Nostoc muscorum. • R- metalaxyl induced photosynthesis inhibition and oxidative damage which were less pronounced in A. laxa. • Our analyses implicated the role of antioxidant defence system in R- metalaxyl stress tolerance in A. laxa. • A. laxa is a promising species for R- metalaxyl phycoremediation. Main finding: R- metalaxyl-induced toxicity in cyanobacteria was a function of dose and species type. Although Anabaena laxa accumulated more R- metalaxyl, it experienced less stress due to its antioxidant defense system. A. laxa may be a promising R- metalaxyl phycoremediator. [ABSTRACT FROM AUTHOR]

Nano-titanium dioxide (nTiO 2) has been reported to improve tolerance of plants against different environmental stresses by modulating various physiological and biochemical processes. Nitric oxide (NO) has been shown to act as an important stress signaling molecule during plant responses to abiotic stresses. The present work was planned to investigate the involvement of endogenous NO in nTiO 2 -induced activation of defense system of fava bean (Vicia faba L.) plants under water-deficit stress (WDS) conditions. Water-suffered plants showed increased concentration of hydrogen peroxide (H 2 O 2) and superoxide (O 2 −) content coupled with increased electrolyte leakage and lipid peroxidation which adversely affected nitrate reductase (NR) activity, chlorophyll content and growth of the plants. However, application of 15 mg L−1 nTiO 2 to stressed plants significantly induced NR activity and synthesis of NO which elevated enzymatic and non-enzymatic defense system of the stressed plants and suppressed the generation of H 2 O 2 and O 2 − content, leakage of electrolytes, and lipid peroxidation. Application of nTiO 2 , in association with NO, also enhanced the accumulation of osmolytes (proline and glycine betaine) that assisted the stressed plants in osmotic adjustment as witnessed by improved hydration level of the plants. Involvement of NO in nTiO 2 -induced activation of defense system was confirmed with NO scavenger cPTIO [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide] which caused recurrence of WDS. Image 1 • Water-deficit stress (WDS) causes severe damage to crops worldwide. • Nano-titanium dioxide (nTiO 2) protects the plants against WDS. • nTiO 2 counters WDS-induced oxidative and osmotic stress. • nTiO 2 induces antioxidant defense system and osmolytes accumulation. • nTiO 2 involves endogenous nitric oxide in the activation of plant's defense system. [ABSTRACT FROM AUTHOR]

Iron in excess can have toxic effects on living organisms. In China, the freshwater crayfish Procambarus clarkii is a source of aquatic food with high-quality protein and has significant commercial value. P. clarkii shows oxidative stress on exposure to heavy metals, and antioxidant enzymes, such as ubiquitination enzymes and proteasomes, play important roles in oxidative stress. To understand the antioxidant defense system of P. clarkii , we analyzed the hepatopancreas transcriptomes of P. clarkii after stimulation with FeCl 3. In total, 5199 differentially expressed genes (DEGs) were identified (2747 upregulated and 2452 downregulated). GO analysis revealed that these DEGs belonged to 16 cellular component, 16 molecular function, and 19 biological process subcategories. A total of 1069 DEGs were classified into 25 categories by using COG. Some antioxidant defense pathways, such as "Ubiquitin mediated proteolysis" and "Glutathione metabolism," were identified using KEGG. In addition, quantitative real time-PCR (qRT-PCR) substantiate d the up-regulation of a random selection of DEGs including antioxidant and immune defense genes. We obtained information for P. clarkii transcriptome databases and new insights into the responses of P. clarkii hepatopancreas to heavy metals. • The hepatopancreas transcriptomes of Procambarus clarkii were constructed using high-throughput sequencing. • The expressions of antioxidant and immune defense genes were induced in response to Fe (III) stress. • Totally 30,438 unigenes was obtained from the transcriptome. • Totally 5199 DGEs were identified including 2747 up- and 2452 down-regulated unigenes. [ABSTRACT FROM AUTHOR]