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Background: Cells have complex network of antioxidant enzymes that protect cells from induced damages by reactive oxygen species (ROS). Catalase and superoxide dismutase are known for their role as primary protection against oxidative stress. Oxidative damage is an important risk factor in age-related macular degeneration disease (AMD). For the first time in this study the impact of genetic polymorphisms of SOD1 and CAT with AMD has been examined. Hence, the association between genetic polymorphisms of catalase (CAT) C-262T, Cu/Zn superoxide dismutase (SOD1) A251G and risk of exudative AMD has been investigated. Methods: This study was carried out on blood samples collected from 112 exudative AMD patients and 112 healthy individuals. Genotyping of CAT C-262T and SOD1A251G was done by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. Differences in the frequencies were estimated using the χ2 test and risk was estimated with a logistic regression after adjusting for smoking, working place and age status. Results: There was significant difference between CAT CT+TT genotype and AMD disease (P=0.009, OR=0.38, 95%CI=0.18-0.78). Also T-allele has a significant association with risk of AMD and decreases risk of disease (P=0.036, OR=0.59, 95%CI=0.36-0.96), but there was no significant differences between SOD1A251G and variant homozygous and heterozygous frequencies in patients compared to controls (P=0.589, OR=0.77, 95%CI=0.3-1.96). Conclusions: The data presented suggest that the T-allele in CAT genotypes can increase catalase expression and activity, as a result of which generation of reactive oxygen species (ROS) can be decreased. Therefore it is suggested that increased expression of CAT as a result of T-allele in CAT genotypes and existence of T-allele in CAT genotypes is associated with decreased risk of AMD.

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Background: Despite the genetic heterogeneity reported in familial ALS (FALS), SOD1 gene mutations are the most frequent cause of FALS, accounting for around 20% of familial cases (ALS1) and isolated sporadic cases. Mutant forms of SOD1 exhibit toxicity that promotes the death of motor neurons. It is well documented that FALS produces protein aggregates in the motor neurons of FALS patients, which have been found to be associated to mitochondria. Methods: In this study, we cloned the SOD1 gene, using reverse transcriptase-polymerase chain reaction (RT-PCR) method, from both a healthy control and a living 79 -year-old man with diagnosis of sporadic form of ALS who had shown unusual rapid progression of disease. RNA samples were available from lymphocytes of them. pET28a expression system and BL21 chemically competent Escherichia coli strain as host were used for protein expression. Results: DNA Sequencing data showed both heterozygosis C to G transition at nucleotide position 21 leading to a C6W changing at protein level and a deletion at nucleotides position 73 to 169 leading to complete deletion of exon two.

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The aims of this study were to assess the effects of drought stress on peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) activities as well as free proline content and growth parameters of Pistacia khinjuk seedlings under drought stress. Therefore, the one-year seedlings of Pistacia khinjuk subjected to water stress (25%, 50%, 75%, and 100% field capacity) for 8 months in greenhouse condition. Results showed that drought stress decreased height, collar diameter, shoot dry weight and root dry weight of P. khinjuk seedlings. But it had different effects onantioxidant enzyme activities in root and shoot of P. khinjuk seedlings. Drought stress increased CAT activity in shoot and root of seedlings and its activity was higher in 25% field capacity (FC) than other treatments. Also, the POD enzyme activity increased in root and shoot of seedlings subjected to drought stress. The SOD activity was at the lowest level in 100% FC than other treatments. The results also showed that free proline accumulation was lower in well watered seedlings and increased under drought stress.

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Objective: Ischemic preconditioning (IPC) is an endogenous phenomenon that can induce ischemic tolerance (IT) in variety of organs such as brain. In this study, we examined the intermittent and prolonged normobaric hyperoxia (HO) on neurologic deficit scores, infarct volume, and superoxide dismutase activity. Materials and Methods: The rats were divided to four main groups. First two main groups were exposed with HO in prolonged (24 h; PrHO) and intermittent (4 h×6 days; InHO) groups and second two main group acted as controls, and were exposed to 21% oxygen in the same chamber (room air, RA) continuously (24 h; PrRA) and discontinuously (4 h×6 days; InRA). Each group subdivided to three subgroups. After 24 h, first subgroup were subjected to 60 minutes MCAO followed by 24 h of reperfusion. Then, IT induced by InHO and PrHO were measured by neurologic deficit scores and infarct volume. Second and third subgroups were called sham-operated and intact subgroups for assessment of the effect of HO on superoxide dismutase activity. Results: Our findings indicate that InHO and PrHO are involved in the induction of IT. Pretreatment with InHO and PrHO reduced neurologic deficit scores and infarct volume significantly. InHO and PrHO increase superoxide dismutase activity significantly. Conclusion: Although further studies are needed to clarify the mechanisms of ischemic tolerance, InHO and PrHO seem to partly exert their effects via increase superoxide dismutase activity.

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Trichosanthes kirilowii, an important economic plant in China, is sensitive to chilling. To investigate the effect of abscisic acid (ABA) treatment on the chilling tolerance of Trichosanthes kirilowii Maxim, different concentrations of ABA were sprayed on Trichosanthes kirilowii leaves and the resulting catalase (CAT) and superoxide dismutase (SOD) activities and the malondialdehyde (MDA) content in the leaves were determined. The results indicated that at 4 ºC, the CAT and SOD activities increased at first and then decreased with increasing ABA concentration. By contrast, the MDA content decreased at first and then increased. They both had an extreme value when sprayed with 5.0 or 7.5 mg L^-1 ABA. A real-time polymerase chain reaction was performed to investigate the influence of exogenous ABA on the CAT gene expression of Trichosanthes kirilowii leaves. The results indicated that at 4 ºC, the CAT relative gene expression showed a high degree of positive correlation with the enzyme activities of CAT and SOD, and a negative correlation with MDA content. These results led to three conclusions. First, exogenous ABA exhibits significant effect on the chilling tolerance of Trichosanthes kirilowii. Second, exogenous ABA significantly increases the enzyme activities of CAT and SOD under cold environments. Finally, under cold environments and the effect of ABA, the relative gene expression of catalase 2 (CAT2) gene was found to play an important role in the enhancement of the chilling tolerance of Trichosanthes kirilowii leaves.

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  Objective: Electro-magnetic radiation (EMR) is emitted from mobile phones. Various researches have shown relationships between mobile phone EMR exposure to cancer and neurologic damages. This study aims to investigate the effects of mobile phone EMR on brain antioxidant enzyme activity and the learning process. Methods: Rat pups and their dames were exposed to EMR for 3 h per day from P2 to P14. After separation of male and female rats on P22, the rats were housed in an air room under normal animal conditions. From P59 to P61, male rats were trained three times per day for a total of 3 days. On P62, their behavior was assessed. The rats were sacrificed by decapitation and the levels of superoxide dismutase and catalase in their brains were assessed. Results: The amount of time to locate the hidden platform and time spent exhibiting freezing behavior increased in exposed group compared to the control group. Superoxide dismutase and catalase activities were reduced in the mobile phone group. Conclusion: Additional studies are necessary to clarify the relationship between mobile phone radiation and brain tissue with regards to antioxidant enzyme activities, learning and memory. Our results suggest that mobile phone radiation may lead to decreased learning that is induced by abnormalities in antioxidant enzyme activities.

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Selenium is an essential element for humans, therefore, adding it to plants is convenient for biofortification. Thus, the aim of this work was to analyze experimentally the ability of sodium selenite to increase the concentration of Se and modify the antioxidant activity in tomato plants. We used plants of the Toro hybrid variety and applied three treatments: 0, 2 and 5 mg L^-1 of selenium as sodium selenite (Na₂SeO₃) using an irrigation system. Three samplings 40, 80, and 120 days after transplantation and a quantification of the accumulation of selenium and macronutrients in leaves, stems, and fruits were carried out. Plant height, stem diameter, firmness, and total solids of fruits and total dry matter were measured. The enzyme activity of catalase, glutathione peroxidase, and superoxide dismutase was quantified. The results indicated positive effects of Se on agronomic variables of the plants and fruit quality; however, fruit production showed no significant differences. Se had no effect on the concentration of the macro and micronutrients. The addition of 5 mg L^-1 of Se resulted in significant increases in the concentration of selenium on a dry basis, reaching 20.4 µg g^-1 in leaves, 52.3 µg g^-1 in stems, and 35.8 µg g^-1 in fruits. The increase in enzyme activity in the fruits was enhanced by the application of 5 mg L^-1 of Se: There was up to 352.7% more catalase activity, 312.2% more glutathione peroxidase activity, and 200.8% more superoxide dismutase activity compared with the control.

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This study investigated the effects of foliar application of normal and nanoparticles of zinc oxide (ZnO) on the growth, proline content, and some antioxidant enzyme activities of sunflower cultivars at different salinity levels. Treatments included five cultivars (Helianthus annuus L. cvs. Alstar, Olsion, Yourflor, Hysun36, and Hysun33), two salinity levels (0 and 100 mM NaCl), and three foliar applications (none-sprayed, ZnO normal and nanoparticles at a rate of 2 g/L). Olsion showed the highest proline content and superoxide dismutase activity (SOD) among the studied cultivars under saline condition. Foliar spray of ZnO improved SOD activity and shoot dry weight of sunflower. Nanoparticles of ZnO had positive effect on biomass production of sunflower plants compared to the normal form. According to the result, Olsion and Hysun33 cultivars were suitable for saline conditions, whereas Hysun36 was appropriate for normal condition.

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Gerbera is one of the significant cut flower crops worldwide suffering from loss of flower quality induced mainly by Calcium (Ca) deficiency. In this research, the influence of Humic Acid (HA) and Ca in nutrient solution was studied on the growth parameters of gerbera. A completely randomized hydroponic experiment was designed by adding HA (0, 100, 500, and 1,000 mg L^-1) and Ca (3.5 and 7 meq L^-1 nutrient solution) to the nutrient solution of gerbera, with three replications. The effects of the treatments were evaluated on the growth, protein content, proline content, transpiration, CO₂ assimilation, photosynthesis, SPAD value, number of harvested flower, and antioxidant activity in gerbera cv. Malibu. Results showed that decreasing Ca level to 3.5 meq L^-1 decreased Superoxide Dismutase (SOD), Peroxidase (POD), and CO₂ assimilation. However, this treatment caused an increase in Malondialdehyde (MDA), protein content, proline content, chlorophyll, and photosynthesis. Transpiration and number of harvested flowers were not affected by Ca concentration significantly. The highest level of HA (1,000 mg L^-1) increased POD and transpiration (30 and 11%, respectively). However, SOD and protein content increased at 500 and 1,000 mg L^-1 HA levels. When HA was accompanied with Ca, SPAD value, transpiration, and CO₂ assimilation were improved, especially at high levels of HA (500 and 1,000 mg L^-1) and higher level of Ca (7 meq L^-1 Ca). The results suggested that HA could increase the number of harvested flowers and improve plant health by enhancing the plant enzymatic antioxidant defense system.