Activity Of Antioxidant Defense System Research Articles

Nitric oxide is involved in nano-titanium dioxide-induced activation of antioxidant defense system and accumulation of osmolytes under water-deficit stress in Vicia faba L.

Nano-titanium dioxide (nTiO2) 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 nTiO2-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 (H2O2) and superoxide (O2-) 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 15mgL-1 nTiO2 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 H2O2 and O2- content, leakage of electrolytes, and lipid peroxidation. Application of nTiO2, 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 nTiO2-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.

In Vivo Metabolic Response upon Exposure to Gold Nanorod Core/Silver Shell Nanostructures: Modulation of Inflammation and Upregulation of Dopamine.

With the increasing applications of silver nanoparticles (Ag NPs), the concerns of widespread human exposure as well as subsequent health risks have been continuously growing. The acute and chronic toxicities of Ag NPs in cellular tests and animal tests have been widely investigated. Accumulating evidence shows that Ag NPs can induce inflammation, yet the overall mechanism is incomplete. Herein, using gold nanorod core/silver shell nanostructures (Au@Ag NRs) as a model system, we studied the influence on mice liver and lungs from the viewpoint of metabolism. In agreement with previous studies, Au@Ag NRs’ intravenous exposure caused inflammatory reaction, accompanying with metabolic alterations, including energy metabolism, membrane/choline metabolism, redox metabolism, and purine metabolism, the disturbances of which contribute to inflammation. At the same time, dopamine metabolism in liver was also changed. This is the first time to observe the production of dopamine in non-neural tissue after treatment with Ag NPs. As the upregulation of dopamine resists inflammation, it indicates the activation of antioxidant defense systems against oxidative stress induced by Au@Ag NRs. In the end, our findings deepened the understanding of molecular mechanisms of Ag NPs-induced inflammation and provide assistance in the rational design of their biomedical applications.

Ozone therapy can be considered as an integrative therapy in oncology? [abstract

BACKGROUND: Our group in Policlinic Umberto I - University Hospital of Sapienza Rome - has decided to further investigate if Ozone therapy can be of support in oncology.
 In literature it has been reported that ozone applications in oncology or in cancer cells is associated with: high efficiency in preventing chemotherapy complications (nausea, vomiting, opportunistic infections, asthenia) as well as confining or restricting the expansion of tumours.(1-5)
 
 PURPOSE: The aim of our study in to evaluate and eventually confirm the validity of ozone treatments in order to consider such procedures as a possible and concrete support therapy for oncology patients undertaking chemotherapy. A statistical significance and clinical evaluation of our work would finally give a scientifically validation, still missing, to officially consider ozone therapy as one of the many possible integrative therapy in oncology.
 
 DESIGN: It is a pilot study designed and approved by the Ethical Committee of the University of Rome, La Sapienza (March 2017) to evaluate quality of life and reduction of side effects of adjuvant chemotherapy in 20 breast cancer patients.
 
 METHODS: The selected patients will be treated with systemic ozone treatment: Ozonated autohemotherapy will be performed according to the following method: 200 ml venous blood will be exposed an equal amount of O2 /O3 (200 ml) The ozone concentration will be gradually increased as follows: 20-30-40 mcrg/mL with a specific schedule until each patient will receive 15 applications overall. The sessions will be scheduled according to a specific timetable during the administration of adjuvant chemotherapy by means of Epirubicin and Cyclophsphamide (EC) every 3 weeks for 4 cycles followed by Paclitaxel for 12 consecutive weeks.
 
 Ozone therapy will not be applied on days of chemotherapy in order to avoid interaction between chemotherapeutics and ozonides. Biochemical blood analysis and stress oxidative blood test will be used as parameters for activity of antioxidant defence system. Quality of life will be evaluated with Fact G Test.
 
 It is the first study to have been evaluated and approved by an official university ethical committee and we will be glad to publish our result as soon as possible. On this behalf it would be great if any other centre could be interested in cooperating with us so to transform this pilot study into a multicentre study with larger numbers and therefore, with a greater impact on the international community.
 
 Our aim is to give cancer patients a better life quality in general and especially help them overcome all the side effects during the chemotherapy. This could open a new scenario in the alternative complementary treatments in oncology.

Exposure to Lead (Pb) Induced Changes in the Metabolite Content, Antioxidant Activity and Growth of Jatropha curcas (L.)

Lead (Pb) is a rapidly increasing heavy metal due to different human activities. It is highly toxic to plants, and its toxicity can impair various morphological, physiological and biochemical functions in plants. In the present study, an experiment was designed to investigate the response mechanisms to counteract Pb in the seedlings of Jatropha curcas. For this purpose, Pb accumulation, metabolite contents, antioxidant activity and accumulation of antioxidants such as phenolics and flavonoids were evaluated. The transcription levels of two genes, metallothioneins (JcMT2a) and phenylalanine ammonia-lyase (JcPAL), involved in the metal detoxification mechanism were also analyzed. The seedlings of J. curcas were hydroponically treated with different doses of Pb (0, 0.5, 5, 10, 20 and 40 mg/L). With increasing Pb dose in the nutrient solution, its accumulation was in the following pattern: roots> stems> leaves. The seedlings showed higher tolerance index (TI) in the highest Pb concentration. The dry weights of roots, stems and leaves, and the total content of proteins were significantly decreased with increasing Pb concentration. However, the photosynthetic pigments, total phenolic and flavonoid compounds were increased in response to elevated Pb concentrations. This was associated with increasing of total antioxidant capacity and radical scavenging activity. Relative transcription of JcMT2a and JcPAL showed distinct pattern in roots and leaves. Integral mechanism for Pb stress tolerance was likely accomplished by activation of antioxidant defense system which was evidenced by up regulation of JcPAL. Our study provides biochemical and genetic basis of Pb-induced defense mechanisms for metal detoxification in J. curcas.

Nitric oxide improved salt stress tolerance by osmolyte accumulation and activation of antioxidant defense system in seedling of B. juncea (L.) Czern

The present manuscript elucidates the cytoprotective role of nitric oxide and its relation with ROS and antioxidants in minimizing the effect of salinity in B. juncea (Indian mustard) which is an important salt tolerant crop of arid and semi arid region. NO alleviates the adverse effect of salt on growth, biomass, relative water content and photosynthesis. At 50 mM NaCl concentration, rapid accumulation of NO was observed that is 2.02 folds higher in roots respectively while in leaves and roots insignificant changes were observed. At higher concentration of salt stress (70–100 mM NaCl), considerable rise in H2O2 content and membrane damage were documented which restrained by the application of 100 µM SNP. NO mitigates the salt stress by regulating the activities of nitrate reductase and other antioxidants. Reduction in NO content was observed in independent treatment of NaCl and SNP in comparison to combined treatment of SNP + NaCl (100 µM SNP + 50 mM NaCl). The different antioxidant enzymes show disparate behaviour with signalling molecule NO. The activity of catalase, guaiacol peroxidase and nitrate reductase were upregulated whereas ascorbate peroxidase was downregulated with NO. The elevated activities of antioxidant and NO accumulation might be responsible for detoxifying the detrimental effect of salinity in B. juncea. The current investigation emphasizes on the potential role of NO in salt stress tolerance by regulating antioxidative defense metabolism, cellular homeostasis and detoxification mechanism in seedlings of B. juncea.

PHYSIOLOGICAL AND BIOCHEMICALS CHANGES MODULATED BY SEEDS’ PRIMING OF LENTIL (Lens culinaris L.) UNDER SALT STRESS AT GERMINATION STAGE

Seed priming is one of the potential physiological approaches to enhance seed germination under salt stress. The present study examined the role of two seed priming molecules, salicylic acid (SA) and hydrogen peroxide (H2O2), to enhance the salt tolerance in lentil seeds at germination stage. Salt stress caused significant decrease in germination percentage and primary root elongation. This decrease was associated with significant increase in lipid peroxidation and total lipid (TL) contents in embryonic axis. The catalase (CAT), guaiacol peroxydase (GPOX) and superoxide dismutase (SOD) activities remained unchanged or decreased significantly under the influence of salt stress, in both embryonic axis and cotyledons. Starch mobilization was not affected by salt stress. The two priming treatments effectively alleviated the negative effects of salt stress. SA and H2O2 applications after dose optimization resulted in significant enhancement of germination percentage and primary root elongation. No significant changes in starch, soluble sugars contents and SOD activity were detected following SA and H2O2 treatments. Seed priming treatments triggered the activities of GPOX and CAT and caused the reduction of lipid peroxidation especially in embryonic axis. TL content and especially the fatty acid C18:3 increased after SA applications. The better performance under salt stress of primed lentil seeds was associated with lower lipid peroxidation, and activation of enzymatic antioxidative defense system. Obtained results confirm the potential for using SA and H2O2 to improve germination and plant growth under salt stress conditions.

Biochemical and molecular changes mediated by plasticizer diethyl phthalate in Chironomus circumdatus (bloodworms)

Plasticizers are used as additives in making plastics. Diethyl phthalate (DEP) is one of the majorly used plasticizers in various products. When plastic materials are dumped in an aquatic system, there is an increase in chances of DEP leaching out and getting deposited in water. Thus the current work focuses on studying the effect of DEP on the larval stages of Chironomus circumdatus. In this study it was found that there was an increase in lipid peroxidation levels indicating imposition of oxidative stress on these larvae due to the exposure of DEP. Changes in the levels of carbohydrates and lipids were also seen. To reduce these effects antioxidant defense system may get activated. Thus investigations showed an increase in enzymatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and acetylcholinesterases (AchE) and decrease in the activity of glutathione reductase (GR). Nonenzymatic antioxidant glutathione levels were also increased during the post-recovery exposure period. Thus this indicates that both enzymatic, as well as non-enzymatic antioxidants, play a certain role in reducing the stress mediated by DEP. Up-regulation of gene expression of heat shock protein70 (hsp70) was observed, which is one of the conserved protein produced during stress response in many dipterans. Changes in the level of expression of the ecdysone receptor (EcR) gene were also seen in DEP exposed larvae. Thus the insights give us a preliminary indication that physiological and developmental adaptations may take place in these organisms to persist in the DEP contaminated environment. CapsuleDEP mediated stress imposes changes in the metabolites and thus activation of antioxidant defense system in aquatic midges of Chironomus circumdatus. Changes in the expression of heat shock protein70 and ecdysone receptor was also seen indicating that DEP mediated stress affects at the molecular level also of the organism. These changes may help them to tolerate and live in DEP polluted water.

The ABA receptor-like gene VyPYL9 from drought-resistance wild grapevine confers drought tolerance and ABA hypersensitivity in Arabidopsis

The PYR/PYL/RCAR (hereafter referred to PYLs) proteins, which act as abscisic acid (ABA) receptors, have been reported to play a crucial role in response to drought stress. In this study, we used a drought-resistant accession of the wild Chinese grapevine, Vitis yeshanensis-’Yanshan-1’, as a model to understand the function of PYLs in grape and other fruit crops. We cloned six PYL genes from V. yeshanensis. Phylogenetic analysis showed that the encoded proteins could be classified into three subfamilies. All six grapevine PYL proteins contained conserved amino acids at positions implicated in ‘gate-and-latch’ mechanism of ABA binding and in the interaction with PP2C proteins. Gene expression profiles of VyPYLs in various tissues of ‘Yanshan-1’ plants revealed they were relatively strongly expressed in old leaves compared to young leaves. Analysis of the subcellular localization of the VyPYL proteins showed that they were localized in the cytoplasm and the nucleus. Yeast two-hybrid assays revealed that six VyPYL proteins selectively interacted with three VyPP2C proteins in an ABA-dependent or ABA-independent manner. Expression of one of the genes, VyPYL9, was induced by exogenous ABA and drought conditions. Heterologous expression of VyPYL9 in Arabidopsis enhanced ABA sensitivity during seed germination and primary root growth. Moreover, VyPYL9-expressing Arabidopsis plants showed enhanced drought tolerance, and this was associated with decreased water loss and increased activity of antioxidant defense systems. In addition, we found that ABA promoted leaf senescence in Arabidopsis plants expressing VyPYL9. Taken together, our results suggest that VyPYL9 may be involved in response of grapevine to drought stress via the ABA signaling pathway. VyPYL9-expressing Arabidopsis plants showed enhanced drought tolerance, and this was associated with decreased water loss and increased activity of antioxidant defense systems. In addition, we found that ABA promoted leaf senescence in Arabidopsis plants expressing VyPYL9.

Rutin ameliorates mercuric chloride-induced hepatotoxicity in rats via interfering with oxidative stress, inflammation and apoptosis

ObjectiveMercury is a global environmental pollutant and is responsible for several organ pathophysiology including oxidative stress-induced liver disorders. Therefore, the present study was conducted to evaluate the potential ameliorative effects of rutin on mercury chloride (HgCl2)-induced hepatotoxicity in adult male rats. MethodsHgCl2 was intraperitoneally injected at a dose of 1.23 mg/kg body weight for 7 days alone or in combination with the orally rutin (50 and 100 mg/kg body weight). ResultsRutin treatment significantly improved liver function tests [alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], and increased activities of antioxidant defense system [catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)] and glutathione (GSH) content. The histological alterations and epidermal growth factor receptor (EGFR) expression in the HgCl2-induced liver tissues were decreased by administration of rutin. Furthermore, rutin reversed the changes in levels of apoptosis and inflammation related proteins involving p53, Bcl-2 associated X protein (Bax), B-cell lymphoma-2 (Bcl-2), cytochrome c, nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), B-cell lymphoma-3(Bcl-3) and interleukin-1β (IL-1β), and inhibited p38α mitogen-activated protein kinase (MAPK) and cysteine aspartate specific protease-3 (caspase-3) activations. ConclusionThe data of the present study suggest that rutin effectively suppress HgCl2‐induced hepatotoxicity by ameliorating oxidative stress, inflammation and apoptosis.

Antioxidant and stress modulatory efficacy of essential oil extracted from plantation-grown Santalum album L.

The East Indian sandalwood oil has been widely used as an Ayurvedic medicine and has multiple pharmacological properties. However, antioxidant and antistress potency of East Indian sandalwood oil against oxidative stress-induced damages remain unexplored. Thus, the present study was aimed to investigate the in vitro and in vivo antioxidant and stress-protective properties of essential oil extracted from the heartwood of plantation-grown Santalum album L. (SEO). The SEO was extracted by traditional stream distillation method and the chemical components were determined via gas chromatography-mass spectrometry (GC–MS) analysis. Nineteen chemical compounds were identified by GC–MS, accounting for 96.81% of total oil. The main components were α-santalol (41.77%), β-santalol (18.02%), (Z)-α-trans-bergamotol (8.50%), (Z)-lanceol (6.57%), and epi-β-santalol (5.78%). The in vitro results suggests that SEO possess an excellent antioxidant activity as it was able to inhibits the intracellular reactive oxygen species (ROS) generation, reverse the morphological damages and effectively improves viability of neural cells under oxidative stress conditions. Moreover, SEO markedly increased the antioxidant enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase. Western blotting results further confirmed that SEO protects neural cells against oxidative damages possibly by activating the nuclear factor-erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) antioxidant mechanism. The SEO also exhibited a strong in vivo antioxidant and stress modulatory activity on Caenorhabditis elegans. The SEO not only acts protective against oxidative stress but also prolongs the lifespan of mev-1 mutant C. elegans having shortened lifespan due to the over production of ROS. This data confirmed that SEO exert potent antioxidant and stress modulatory activities possibly by direct scavenging of free radicals and activation of antioxidant defense system, in vitro and in vivo. Together, these findings indicated that SEO has the potency to be utilized as a source of antioxidant for treating several degenerative and disease conditions caused by oxidative stress.

Effect of a Prolonged Dietary Iron Intake on the Gene Expression and Activity of the Testicular Antioxidant Defense System in Rats.

Despite the fact that iron represents a crucial element for the catalysis of many metabolic reactions, its accumulation in the cell leads to the production of reactive oxygen species (ROS), provoking pathological conditions such as cancer, cardiovascular diseases, diabetes, neurodegenerative diseases, and fertility. Thus, ROS are neutralized by the enzymatic antioxidant system for the purpose of protecting cells against any damage. Iron is a potential risk factor for male fertility. However, the mechanism of action of iron on the testicular antioxidant system at the gene and protein levels is not fully understood. Thus, the purpose of the current research was to ensure a better understanding of how the long-term iron treatment influences both gene expression and enzyme activities of the testicular antioxidant system in rat testis. The data of our study showed that a significant dose-dependent increase occurred in the iron level in rat testis. A reduction occurred in reduced glutathione (GSH) levels, which represent a marker of oxidative stress, along with long-term iron overload. The expression and activity of glucose 6-phosphate dehydrogenase (G6pd), glutathione reductase (Gr), glutathione peroxidase (Gpx), and glutathione S-transferases (Gst) were significantly affected by the presence of iron. The findings of the current research demonstrate that the long-term toxic dietary iron overload influences the gene expression and enzyme activity of the testicular antioxidant defense system, but the actual effect occurs at the protein level. This may modify the sperm function and dysfunction of the male reproductive system.

Antihepatocarcinogenic activity of whey protein concentrate and lactoferrin in diethylnitrosamine-treated male albino mice.

Hepatocellular carcinoma is considered one of the most prevalent and lethal malignancies worldwide. Chemotherapy with cytotoxic agents showed a low response rate with possible toxic effects. Recently, some emphases have been placed on the anticancer properties of bovine whey protein and its components, especially lactoferrin. The present study aimed to evaluate and compare the antihepatocarcinogenic activity of bovine whey protein concentrate (WPC, 300 and 600 mg/kg body weight) and lactoferrin (30 and 60 mg/kg body weight), orally and daily for 14 weeks, in the mice model of diethylnitrosamine (DEN)-induced hepatocarcinogenesis. The results showed that both WPC and lactoferrin (in a dose-dependent manner) alleviated significantly (P < .001) the elevation in serum markers of liver carcinoma and inflammation in the DEN-treated mice. Also, they exhibited a great amelioration in the livers' histological structure of the DEN-treated mice by 37.0% to 66.7%. In addition, they decreased significantly (P < .001) the hepatic DNA fragmentation in the DEN-treated mice by 23.1% to 32.7%. Only, the high doses of WPC and lactoferrin completely modulated the decrease in the activity of liver enzymic antioxidant defense system (catalase, glutathione peroxidase, and superoxide dismutase) and improved significantly (P < .01-.001) the concentration of hepatic reduced glutathione of the DEN-treated mice. Moreover, the high doses of WPC and lactoferrin reduced significantly (P < .05-.001) the elevation in the concentrations of hepatic active caspases 3, 8, and 9 of the DEN-treated mice. In conclusion, both WPC and lactoferrin were effective in inhibiting the hepatocarcinogenic activity of DEN in mice model through their ability to alleviate the hepatic inflammation and apoptosis.

Influence of feed additive “Butaselmevit-Plus” on antioxidant status of rats in conditions of oxidative stress

The purpose of the work was to investigate the effect of the feed supplement “Butaselmevit Plus” on the antioxidant status of the organism in rats under conditions of oxidative stress. The research was carried out on white, sexually-mature, young male rats of the Wistar line, with a body weight of 180–200 g, which was kept on a standard diet of the Institute vivarium of the State Scientific-Research Control Institute of Veterinary Preparations and Feed Supplements. The animals were divided into three groups of 20 animals in each: 1st group (K) intact animals; Group 2 (R1) – rats, affected with tetrachloromethane; Group 3 (R2) – rats, affected with tetrachloromethane and used as a feed additive “Butaselmevit-Plus”. The feed supplement “Butaselmevit-Plus” includes the fruits of thistle spotted, methionine, sodium selenite and vitamins A, E, D3. Significant violation of oxidative-antioxidant balance in animals under oxidative stress conditions, which is characterized, primarily, by activation of processes of radical lipid oxidation with excessive accumulation of both intermediate and final products of lipid peroxidation oxidation and inhibition of antioxidant defense system activity, is established. The development of oxidative stress leads to the inhibition of the activity of the glutathione system of antioxidant protection of the body of rats. This is evidenced by the low activity of glutathione peroxidase and the low level of reduced glutathione in the blood of experimental rats. The feed supplement “Butaselmeib-Plus” contributed to the activation of the system of antioxidant protection of the body of rats for tetrachloromethane poisoning, as evidenced by the increased activity of glutathione peroxidase and the level of reduced glutathione. In addition, in the blood of experimental rats, inhibition of lipid peroxidation and formation of free radicals was observed. It was determined that the level of lipids hydroperoxides on the 20th day of the experiment in blood of rats of experimental group R2 decreased by 35.7%, and the level of TBK-active products – by 21.6% relative to the indices of the first experimental group of rats. Thus, the feed supplement “Butaselmevit-Plus” when fed to rats for the development of oxidative stress inhibited lipid peroxidation, as indicated by the low level of lipids hydroperoxides and TBK-active products in their blood. This may be due to the fact that the feed additive includes two strong antioxidants, such as vitamin E and selenium, which in turn enhance the action of each other. It should also be noted that the antioxidant properties of thistle blisters, which, according to the literature, also possess antioxidant properties. It consists of vitamins B, A, E, K, precursors of vitamin D, carotenoids, macroelements – potassium, calcium, magnesium, ferrum and microelements – Cuprum, Zinc, Manganese, Iodine. The combined action of these biologically important elements exhibits high hepatoprotective and antioxidant activity.

Response of Ornamental Pepper to High-Temperature Stress and Role of Exogenous Salicylic Acid in Mitigating High Temperature

Ornamental pepper (Capsicum annuum L.) is an important economic decorative plant well known for its abundant genetic diversity. However, high-temperature (HT) stress seriously affects its aesthetic and commercial value. In this work, we analyzed the effects of exogenous salicylic acid (SA) on seed germination and seedling growth of ornamental pepper under HT stress. The inherent physiological and biochemical basis of the alleviating effect of salicylic acid was further analyzed. The findings revealed SA with 0.01 mM and 0.1 mM was most effective in enhancing thermotolerance in seeds and seedlings, respectively. SA treatment increased the germination rate and germination potential, and reduced the oxidative damage of seeds under HT stress. For seedlings, spraying SA with 0.1 mM significantly alleviated yellow leaves and dwarfing under HT stress. SA could maintain high root vigor, inhibit water loss, and maintain the integrity of cell structure by regulating osmotic substance content under HT. SA-induced thermotolerance development involved in the activation of antioxidant defense system. SA decreased the production of reactive oxygen species (ROS), increased the activity of protective enzymes, and the content of non-enzymatic ROS scavengers in plants under HT. The changes of chlorophyll fluorescence parameters showed that SA was beneficial to maintain a high level of photosynthetic capacity of ornamental pepper seedlings under HT stress. Moreover, recovery also showed a mitigatory effect on injuries induced by HT stress. Taken together, this study provided evidence for the ability of exogenous SA application to moderate the detrimental effects by HT stress.

Role of P-type ATPase metal transporters and plant immunity induced by jasmonic acid against Lead (Pb) toxicity in tomato

The phytohormone jasmonic acid (JA) plays an imperative role in plants by modulating the activity of their antioxidative defense system under stress conditions. Here, we explored the role of JA-induced alterations in the growth and transcript levels of antioxidative enzymes in tomato seedlings exposed to different Pb concentrations (0.25, 0.50, and 0.75 mM). Pb treatment caused a dose-dependent reduction in their root and shoot lengths. Treatment of 0.75 mM Pb showed an increase in the contents of malondialdehyde (MDA), superoxide anion (O2•−), and hydrogen peroxide (H2O2) as compared to the untreated seedlings. Pb uptake was enhanced with an increase in Pb concentration. The seeds primed with JA showed reduction in Pb uptake and improvement in growth under Pb toxicity. The seedlings treated with both JA (100 nM) and Pb (0.75 mM) showed a decline in the levels of MDA, O2•−, and H2O2 as compared to the seedlings treated with 0.75 mM Pb alone. These results suggested that JA (100 nM) mitigated the oxidative damage by lowering the expression of the RBO and P-type ATPase transporter genes and by modulating antioxidative defense system activity. The biochemical and molecular analyses showed that JA plays a crucial role in plant defense responses against Pb stress.

Trehalose increases the oxidative stress tolerance and biocontrol efficacy of Candida oleophila in the microenvironment of pear wounds

Harvested fruit tissues produce reactive oxygen species (ROS) in response to wounding. ROS production is further elevated when biocontrol yeasts are introduced into the wounds, where they act as a bio-elicitor and this results in an environment in which the biocontrol yeast is subject to oxidative stress. In the present study, the effect of trehalose, a non-reducing disaccharide and a major reserve carbohydrate, on the level of oxidative stress tolerance of the biocontrol yeast Candida oleophila was examined in wounded pear fruits. Results indicated that the level of trehalose in C. oleophila yeast cells increased when they were cultured in a trehalose-containing medium. Exposure to a trehalose-medium and the increase in internal trehalose improved the adaptation of C. oleophila to the oxidative environment present in pear fruit wounds. Trehalose-treated cells exhibited a lower accumulation of ROS and mitochondrial impairment compared to untreated, control cells when they were introduced into wounded pear fruit. The trehalose treatment up-regulated the expression of antioxidant genes, including peroxisomal catalase and thioredoxin reductase, in yeast cells. Trehalose-treated yeast also exhibited a faster growth rate in pear wounds and greater biocontrol efficacy against blue mold (Penicillium expansum) and Alternaria rot (Alternaria alternata) than untreated, control yeast. These results support the premise that trehalose improves the biocontrol efficacy of C. oleophila via the activation of antioxidant defense systems which support a faster rate of growth of the yeast in wounds of pear fruit.

Проґнозування віддалених результатів хірурґічного лікування вузлового ендемічного зобу на тлі автоімунного тиреоїдиту

Aim.&nbsp;Determination of markers for clinical course prediction and choice of surgical intervention in patients with nodular&nbsp;goiter&nbsp;againstthe background of autoimmune thyroiditis&nbsp;by studuing the&nbsp;activity of oxidant, autoimmune and apoptotic processes. Materials and Methods.Ninety-fivepatients with unilateral nodular and&nbsp;multinodulargoiter&nbsp;againstthe background of autoimmune thyroiditis after the operation and in the remote postoperative period were examined.&nbsp;The activity of peroxide oxidation and the state of antioxidant systems, the level of proinflammatory cytokines, the activity of apoptotic processes,&nbsp;the&nbsp;thyroid gland function,&nbsp;levels&nbsp;of thyroid peroxidase antibodies, and structural changes in the gland&nbsp;revealed by&nbsp;ultrasound&nbsp;were examined. Result and Discussion. The study shows that in patients with&nbsp;nodulargoiter&nbsp;againstthe background of autoimmune thyroiditis a significant increase in the index of peroxidation and decrease in the activity of antioxidant defense systems against the suppression of apoptotic processes and the activation of proinflammatory cytokines&nbsp;are seen&nbsp;in the remote period after the surgical treatment. These processes lead to functional failure, hyperplasia and progressive structural pathology&nbsp;of the thyroid gland, &nbsp;leading ultimately&nbsp;to progressive&nbsp;functional thyroid gland failure and inadequate long-term outcome of treatment. Conclusions.&nbsp;The conducted study allowed clarifyingindications and contraindications to the selection of surgical procedures in patients with&nbsp;endemic nodular goiter against&nbsp;the background of autoimmune thyroiditis,&nbsp;considering&nbsp;the parameters of oxidative processes, the level of proinflammatory cytokines, apoptosis and the functional capacity of the thyroid gland.

Oxidative stress in epilepsy

This article contains an analysis of clinical and experimental studies in which oxidative stress is considered as a possible mechanism in the pathogenesis of epilepsy. Oxidative stress occurs as a result of brain damage after epileptic seizures and may later cause epileptogenesis. Patients with epilepsy showed a high level of lipid peroxidation markers, while the activity of antioxidant defense system was low. The level of oxidative stress was shown to be significantly higher in epileptics with associated mental disorders and in patients with refractory epilepsy. Further study of oxidative stress in epilepsy may play the key role in the treatment of this disease.

Influence of cadmium loading on glutathione system of antioxidant protection of the bullocks’bodies

It was presented the results of studies of the cadmium effect loading on the activity of the glutathione system of antioxidant protection in young cattle, namely on the activity of glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, the level of reduced glutathion. It was established that feeding of cadmium chloride to bullocks at a dose of 0.03 and 0.05 mg/kg body weight contributed to a decrease in both the enzyme and non-enzyme link of the glutathione antioxidant defense system. The toxic effect of cadmium contributes to a change in stationary concentrations of radical metabolites. О2˙ˉ, ˙ОН, НО2˙, which, in turn, initiate lipid peroxidation processes. The lowest level of glutathione indexes of the antioxidant defense system in the blood of young cattle was established on the sixteenth and twenty fourth day of the experiment, it was associated with enhanced activation of lipoperoxidation and an imbalance between the activity of the antioxidant system and the intensity of lipid peroxidation. The feeding of cadmium chloride to bullocks at a dose of 0.03 and 0.05 mg/kg of animal weight did not affect the activity of the glutathione antioxidant defense system in their blood. It was established that the greater the amount of cadmium chloride in the feed, the lower the activity of the glutathione system of the antioxidant defense of the body of bulls. Thus, cadmium chloride suppresses the antioxidant protection system, in particular, by reducing the activity of the enzyme link: glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and non-enzyme link: reduced glutathione.

Physiological changes and antioxidant enzymes activity in Biquinho and Malagueta pepper seeds during the maturation process

ABSTRACT Seeds held inside fleshy fruits after harvest can continue metabolically active, the process of maturation is not interrupted, which can promote the increase on germination and vigour. Also, during maturation and fruit after-ripening period, changes in the mechanisms of protection against oxidative damage can occur, including the activity of antioxidant enzymes. The aim of this study was to evaluate the physiological quality and enzymatic activity of antioxidant defense system of Capsicum chinense Jacq. Represented by the Biquinho pepper and Capsicum frutescens L. represented by the Malagueta pepper seeds, collected from fruits at different developmental stages and subjected to post-harvest storage. Fruits harvested at 40, 55 and 70 days after anthesis (DAA) were stored at 25 °C, for 0, 6, 12 and 18 days. Seeds were evaluated for germination and accelerated aging tests. In addition, the activities of superoxide dismutase, catalase and peroxidase were determined. For both species, seed from fruits collected at 70 DAA, presenting red colour, have higher germination and vigour compared to the seeds harvested at 40 and 55 DAA. The harvest of the fruits on this stage is recommended for obtain high quality seeds. The after-ripening of Biquinho pepper seeds harvested at 55 DAA contribute to increase the germination potential of the seed, while for Malagueta seeds this procedure has little benefit. The catalase enzyme has great potential to monitor the physiological quality of Biquinho and Malagueta pepper seeds; low activity of this enzyme in seeds during the fruits after-ripening is related to better physiological quality.