Low Molecular Weight Antioxidants Research Articles

Anatomical and hormonal factors determining the development of haploid and zygotic embryos of oat (Avena sativa L.)

A critical step in the production of doubled haploids is a conversion of the haploid embryos into plants. Our study aimed to recognize the reasons for the low germination rate of Avena sativa haploid embryos obtained by distant crossing with maize. Oat cultivars of ‘Krezus’ and ‘Akt’ were investigated regarding embryo anatomy, the endogenous phytohormone profiles, and antioxidant capacity. The zygotic embryos of oat were used as a reference. It was found that twenty-one days old haploid embryos were smaller and had a less advanced structure than zygotic ones. Morphology and anatomy modifications of haploid embryos were accompanied by extremely low levels of endogenous auxins. Higher levels of cytokinins, as well as tenfold higher cytokinin to auxin ratio in haploid than in zygotic embryos, may suggest an earlier stage of development of these former. Individual gibberellins reached higher values in ‘Akt’ haploid embryos than in the respective zygotic ones, while the differences in both types of ‘Krezus’ embryos were not noticed. Additionally to the hormonal regulation of haploid embryogenesis, the poor germination of oat haploid embryos can be a result of the overproduction of reactive oxygen species, and therefore higher levels of low molecular weight antioxidants and stress hormones.

Participation of low molecular weight antioxidants selenium and caffeic acid in the regulation of respiration in Solanum Tuberosum in hypothermic conditions

To study the effect of low molecular weight antioxidants on the respiration process, the content of auxins and abscisic acid, 15-day-old potato (Solanum tuberosum) tubers grown under laboratory conditions were sprayed with 5.8 μM sodium selenite solution or 0.1 mM caffeic acid solution. Control runners were treated with water. Hypothermia (-2 °C) simulating freezing was created for 2 hours. 21-day-old runners were analyzed. Under optimal temperature conditions, the studied antioxidants stimulated the respiration process, while selenite had a greater effect. Caffeic acid increased the maintenance respiration rate. Selenite and caffeic acid increased the auxin content in the runners. Selenite reduced the amount of abscisic acid, resulting in an increase in the indoleacetic acid/abscisic acid ratio. Under hypothermic conditions, caffeic acid significantly reduced the increase in respiration, and in the option with selenite, an insignificant stabilization of this process was noted with a greater decrease in indoleacetic acid/abscisic acid ration as compared with optimal conditions.

Do low molecular weight antioxidants contribute to the Protection against oxidative damage? The interrelation between oxidative stress and low molecular weight antioxidants based on data from the MARK-AGE study

A redox steady state is important in maintaining vital cellular functions and is therefore homeostatically controlled by a number of antioxidative agents, the most important of which are enzymes. Oxidative Stress (OS) is associated with (or/and caused by) excessive production of damaging reactive oxygen and/or nitrogen species (ROS, RNS), which play a role in many pathologies. Because OS is a risk factor for many diseases, much effort (and money) is devoted to early diagnosis and treatment of OS. The desired benefit of the “identify (OS) and treat (by low molecular weight antioxidants, LMWA)” approach is to enable selective treatment of patients under OS. The present work aims at gaining understanding of the benefit of the antioxidants based on interrelationship between the concentration of different OS biomarkers and LMWA. Both the concentrations of a variety of biomarkers and of LMWA were previously determined and some analyses have been published by the MARK-AGE team. For the sake of simplicity, we assume that the concentration of an OS biomarker is a linear function of the concentration of a LMWA (if the association is due to causal relationship). A negative slope of this dependence (and sign of the correlation coefficient) can be intuitively expected for an antioxidant, a positive slope indicates that the LMWA is pro-oxidative, whereas extrapolation of the OS biomarker to [LMWA] = 0 is an approximation of the concentration of the OS biomarker in the absence of the LMWA. Using this strategy, we studied the effects of 12 LMWA (including tocopherols, carotenoids and ascorbic acid) on the OS status, as observed with 8 biomarkers of oxidative damage (including malondialdehyde, protein carbonyls, 3-nitrotyrosine). The results of this communication show that in a cross-sectional study the LMWA contribute little to the redox state and that different “antioxidants” are very different, so that single LMWA treatment of OS is not scientifically justified assuming our simple model. In view of the difficulty of quantitating the OS and the very different effects of various LMWA, the use of the “identify and treat” approach is questionable.

Complex Compound with Transitional Metal of Akway Bark (Drimys piperita Hook F.) as Low Molecular Weight Scavenging Antioxidant: A Computational Study

Akway (Drimys piperita Hook f.) was known as an endogenous plant of Indonesia. This plant was investigated as free radical scavenger based on paramagnetic properties. This study aimed to identify the bioactive compound and the role of Fe metals ions to enhance the free radical scavenger capacity as Low molecular weight antioxidant (LWMA) of akway. This study was designed by ultra-performance liquid chromatography (UPLC) coupled with ultra-high-resolution time of flight-mass spectrometry detector (TOF-MS), docking (Pyrex and Discovery Studio 2016 Client) and pharmacokinetic properties prediction (SwissADME). UPLC-TOF-MS analysis showed that herbal akway bark has five molecular formula (C4H3N10O21-, C14H19N4O91-, C4H7N6O51-, C15H28NO31+, and C23H32NO71+). The docking was illustrated the complex binding akway formula with Fe and its role as a metal donor and metal acceptor. It also confirmed on pharmacokinetics properties prediction which molecular compounds of akway have aqueous solubility. It meant the herbal akway bark complexed to Fe could be a low molecular weight antioxidant and it could be escalated free radical scavenger capacity

Self-Assembling Antioxidants for Ischemia-Reperfusion Injuries.

Significance: Ischemia-reperfusion (IR) injury is a major component of severe damage in vascular occlusion during stroke, myocardial infarction, surgery, and organ transplantation, and is exacerbated by the excessive generation of reactive oxygen species (ROS), which occurs particularly during reperfusion. With the aging of the population, IR injury is becoming a serious problem in various organs, such as the kidney, brain, and heart, as well as in the mesenteric capillaries. Recent Advances: To prevent reperfusion injuries, natural and synthetic low-molecular-weight (LMW) antioxidants have been well studied. Critical Issues: However, these LMW antioxidants have various problems, including adverse effects due to excessive cellular uptake and their rapid clearance by the kidney, and cannot fully exert their potent antioxidant capacity in vivo. Future Directions: To overcome these problems, we designed and developed redox polymers with antioxidants covalently conjugated with them. These polymers self-assemble into nanoparticles in aqueous media, referred to as redox nanoparticles (RNPs). RNPs suppress their uptake into normal cells, accumulate at inflammation sites, and effectively scavenge ROS in damaged tissues. We had developed two types of RNPs: RNPN, which disintegrates in response to acidic pH; and RNPO, which does not collapse, regardless of the environmental pH. Utilizing the pH-sensitive and -insensitive characteristics of RNPN and RNPO, respectively, RNPs were found to exhibit remarkable therapeutic effects on various oxidative stress disorders, including IR injuries. Thus, RNPs are promising nanomedicines for use as next-generation antioxidants. This review summarizes the therapeutic impacts of RNPs in the treatment of kidney, cerebral, myocardial, and intestinal IR injuries. Antioxid. Redox Signal. 36, 70-80.

Impact of Ascorbate-Glutathione Cycle Components on the Effectiveness of Embryogenesis Induction in Isolated Microspore Cultures of Barley and Triticale.

Enhanced antioxidant defence plays an essential role in plant survival under stress conditions. However, excessive antioxidant activity sometimes suppresses the signal necessary for the initiation of the desired biological reactions. One such example is microspore embryogenesis (ME)—a process of embryo-like structure formation triggered by stress in immature male gametophytes. The study focused on the role of reactive oxygen species and antioxidant defence in triticale (×Triticosecale Wittm.) and barley (Hordeum vulgare L.) microspore reprogramming. ME was induced through various stress treatments of tillers and its effectiveness was analysed in terms of ascorbate and glutathione contents, total activity of low molecular weight antioxidants and activities of glutathione–ascorbate cycle enzymes. The most effective treatment for both species was a combination of low temperature and exogenous application of 0.3 M mannitol, with or without 0.3 mM reduced glutathione. The applied treatments induced genotype-specific defence responses. In triticale, both ascorbate and glutathione were associated with ME induction, though the role of glutathione did not seem to be related to its function as a reducing agent. In barley, effective ME was accompanied by an accumulation of ascorbate and high activity of enzymes regulating its redox status, without direct relation to glutathione content.

The effect of hypothermia on the state of the prooxidant-antioxidant system of plants

Aim of the research: to identify changes in the value of indicators of the state of the prooxidant-antioxidant system (PAS) in the tissues of edible parts of agricultural plants under the influence of temperature changes. Methodology: Quantitative determination of indicators of the state of PAS was performed on tissue samples of edible parts of the following plants: Solánum lycopérsicum L., Сucumis sativus L., Capsicum annuum L., Solanum melongena L., Solanum tuberosum L., Allium sativum L., Allium cepa L., Daucus carota L., Beta vulgaris L., Cucurbita pepo var. Giraumontia L. The concentration of superoxide anion radical (•O2-), TBA-active products, superoxide dismutase (SOD) activity, catalase, the concentration of ascorbic acid (AA), glutathione (GSH) were determined. The results of the research show that hypothermia activates both parts of the PAS, however, cooling is accompanied by more powerful both low molecular weight and enzymatic antioxidant (AO) protection. The research of AO can be divided according to the degree of reduction of the protective value in hypothermia in the following series: SOD, catalase, GSH, AA. The most resistant in terms of changes in PAS to hypothermia is Solanum tuberosum L., Allium sativum L., Beta vulgaris L.; the least resistant is Capsicum annuum L., and Solánum lycopérsicum L. The generative organs of plants are less resistant to hypothermia than the vegetative ones. Practical consequences. As a result of the conducted biochemical analysis, it is established which method of storage of plant products is more effective in terms of preservation of AO activity: cooling or freezing.

Newly Developed Self-Assembling Antioxidants as Potential Therapeutics for the Cancers.

Elevated reactive oxygen species (ROS) have been implicated as significant for cancer survival by functioning as oncogene activators and secondary messengers. Hence, the attenuation of ROS-signaling pathways in cancer by antioxidants seems a suitable therapeutic regime for targeting cancers. Low molecular weight (LMW) antioxidants such as 2,2,6,6-tetramethylpyperidine-1-oxyl (TEMPO), although they are catalytically effective in vitro, exerts off-target effects in vivo due to their size, thus, limiting their clinical use. Here, we discuss the superior impacts of our TEMPO radical-conjugated self-assembling antioxidant nanoparticle (RNP) compared to the LMW counterpart in terms of pharmacokinetics, therapeutic effect, and adverse effects in various cancer models.

Changes in Lipid Peroxidation Indexes of the Republic of Sakha (Yakutia) Population Depending on Residence Location

The levels of TBA-active products and antioxidant defense indicators, such as low molecular weight antioxidants (LMWAO from now onward), Vitamin C, catalase, and uric acid, were higher in the new population if compared to indigenous people. When comparing the biochemical parameters by district type, the authors found that in the inhabitants of industrial districts (both new and indigenous), the prooxidant-antioxidant balance (PAB from now onward) was shifted towards higher peroxidation. The increase in antioxidants in the original population was due to higher levels of LMWAO. In the indigenous population it was caused by higher catalase activity. The new population had overstressed adaptive mechanisms, confirmed by higher levels of TBA-active products, Interleukins IL18 and IL6, and AST/ALT ratio. The indigenous residents of arctic districts had significantly lower TBA-active elements, LMWAO, catalase activity, but a higher ascorbic acid level (an endogenous antioxidant) compared to the indigenous population of industrial and agricultural districts. The decrease in lipid peroxidation and the increase in ascorbic acid in the population of Arctic districts may be explained by reduced anthropogenic stress and protein-lipid type nutrition, distinct from the population of other districts.

Antioxidant Status in Paranoid Schizophrenia and Alzheimer’s Disease

Objective. To study measures of the plasma antioxidant profile in patients with paranoid schizophrenia and Alzheimer’s disease (AD). Materials and methods. The study included 33 patients with paranoid schizophrenia and 18 patients with AD. Groups of patients with treatment-resistant schizophrenia and responding positively to treatment were identified. Measures of the antioxidant profile were determined by chemiluminometry and spectrofluorimetry. Results and discussion. Systemic oxidative stress due to lack of plasma low molecular weight antioxidants was not seen in AD though “thiol” protein oxidative stress was detected, providing indirect evidence of insufficiency of the glutathione system. Systemic oxidative stress was also not typical of patients with treatment-resistant paranoid schizophrenia while “thiol” oxidative stress was marked. Patients with paranoid schizophrenia and responding to therapy showed the opposite picture – systemic oxidative stress was more intense and “thiol” oxidative stress was less so. Of the neuroleptics studied, haloperidol, zuclopenthixol, risperidone, and ziprasidone had no antioxidant properties, while pericyazine, clozapine, and especially chlorpromazine had marked antioxidant properties, though they were unlikely have effects on plasma antioxidant potential. These results led to the conclusion that the glutathione component of the antioxidant system is most impaired in treatment-resistant paranoid schizophrenia and AD, while systemic antioxidant stress is minor. Oxidative impairments were less pronounced in successfully treated paranoid schizophrenia.

Reactive Oxygen Species and Their Involvement in Red Blood Cell Damage in Chronic Kidney Disease.

Reactive oxygen species (ROS) released in cells are signaling molecules but can also modify signaling proteins. Red blood cells perform a major role in maintaining the balance of the redox in the blood. The main cytosolic protein of RBC is hemoglobin (Hb), which accounts for 95-97%. Most other proteins are involved in protecting the blood cell from oxidative stress. Hemoglobin is a major factor in initiating oxidative stress within the erythrocyte. RBCs can also be damaged by exogenous oxidants. Hb autoxidation leads to the generation of a superoxide radical, of which the catalyzed or spontaneous dismutation produces hydrogen peroxide. Both oxidants induce hemichrome formation, heme degradation, and release of free iron which is a catalyst for free radical reactions. To maintain the redox balance, appropriate antioxidants are present in the cytosol, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and peroxiredoxin 2 (PRDX2), as well as low molecular weight antioxidants: glutathione, ascorbic acid, lipoic acid, α-tocopherol, β-carotene, and others. Redox imbalance leads to oxidative stress and may be associated with overproduction of ROS and/or insufficient capacity of the antioxidant system. Oxidative stress performs a key role in CKD as evidenced by the high level of markers associated with oxidative damage to proteins, lipids, and DNA in vivo. In addition to the overproduction of ROS, a reduced antioxidant capacity is observed, associated with a decrease in the activity of SOD, GPx, PRDX2, and low molecular weight antioxidants. In addition, hemodialysis is accompanied by oxidative stress in which low-biocompatibility dialysis membranes activate phagocytic cells, especially neutrophils and monocytes, leading to a respiratory burst. This review shows the production of ROS under normal conditions and CKD and its impact on disease progression. Oxidative damage to red blood cells (RBCs) in CKD and their contribution to cardiovascular disease are also discussed.

A Novel Hypothetical Approach to Explain the Mechanisms of Pathogenicity of Rheumatic Arthritis

The autoimmune disorder rheumatoid arthritis (RA) is a relapsing and chronic inflammatory disease that affects the synovial cells, cartilage, bone, and muscle. It is characterised by the accumulation of huge numbers of polymorphonuclear neutrophils (PMNs) and macrophages in the synovia. Auto-antibodies are deposited in the joint via the activity of highly cationic histones released from neutrophil extracellular traps (NETs) in a phenomenon termed NETosis. The cationic histones function as opsonic agents that bind to negatively charged domains in autoantibodies and complement compounds via strong electrostatic forces, facilitating their deposition and endocytosis by synovial cells. However, eventually the main cause of tissue damage is the plethora of toxic pro-inflammatory substances released by activated neutrophils recruited by cytokines. Tissue damage in RA can also be accompanied by infections which, upon bacteriolysis, release cell-wall components that are toxic to tissues. Some amelioration of the damaged cells and tissues in RA may be achieved by the use of highly anionic heparins, which can neutralize cationic histone activity, provided that these polyanions are co-administrated with anti-inflammatory drugs such as steroids, colchicine, or methotrexate, low molecular weight antioxidants, proteinase inhibitors, and phospholipase A2 inhibitors.

Protective effects of quercetin-loaded microcapsules on the enteric nervous system of diabetic rats.

Quercetin-loaded microcapsules (QLM) promote controlled release and higher bioavailability of quercetin, an antioxidant and neuroprotective agent. We evaluated the antioxidant effect of QLM on enteric innervation and in the oxidative status of the ileum of diabetic rats. Wistar adult rats (Rattus norvegicus) were used in six groups containing normoglycemic (N), diabetic (D) and either normoglycemic or diabetic groups treated with QLM at a dose of 10mg/kg (NQ10 and DQ10, respectively) or 100mg/kg (NQ100 and DQ100, respectively). DQ10 e DQ100 did not prevent overall neuronal loss in the total and cholinergic populations. Nitrergic population showed differences regarding the treatments: DQ10 preserved neurons in the nitrergic population whilst DQ100 increased nitrergic loss. Evaluation of the redox status showed pro-oxidant effects in NQ100 by t-butyl-induced chemiluminescence analysis. We observed a reduction in the carbonylic content and an increase of low molecular weight antioxidants for DQ10 e DQ100. Therefore, QLM treatment at a dose of 10mg/kg acted positively on nitrergic neurons reducing oxidative damage induced by diabetes.

Стан ензиматичної та неензиматичної ланок антиоксидантного захисту печінки щурів-пухлиноносіїв за дії лазерного опромінення

The activity of antioxidant enzymes — superoxidedismutase (SOD), catalase and glutathionetransferase, and also the level of low molecular weight antioxidants — vitamin E and ascorbic acid in the liver subcellular fractions of rat with transplanted of Guerin’s carcinoma it was investigated. It is shown that in the liver of tumor-bearing rats in the logarithmic phase of oncogenesis increases the activity of the components of the enzymatic link of the antioxidant system (AOS) and the content of vitamin E with a simultaneous decrease of ascorbic acid. The AOS depletionis expressed by a decrease of antioxidant enzymes activity and a decrease the level of low molecular weight antioxidants in the stationary phase of oncogenesis in the liver cells of tumor-bearing rats. It was found that laser irradiation of rats in the area of tumor growth reduces its effect on liver AOS, which is manifested by increased activity of SOD, catalase and vitamin E content in the stationary phase of Guerin’s carcinoma growth in the body.

Influence of exogenous jasmonic acid on the functioning of a defense system of potato seedlings (<i>Solanum tuberosum</i> L.) grown on artificial ion exchange substrate and infected with potato virus X

The content of reactive oxygen species, the activities of ascorbate-glutathione cycle enzymes, the content of low molecular weight antioxidants: ascorbate and glutathione, the activity of phenolic peroxidase, the content of water-soluble phenols and the expression level of the hypersensitive response marker gene (HSR) and PR protein genes (Chit, Glu and TLP) in potato seedlings grown on an ion-exchange substrate in the presence of jasmonic acid at a concentration of 10 -8 and 10 -6 M and infected with potato virus X were studied. Accumulation of reactive oxygen species, an increase in the content of reduced ascorbate and an intensive consumption of reduced glutathione upon action of jasmonic acid, as well as a sharp increase in the expression of HSR, Chit, Glu, and TLP genes in the leaves of potato seedlings grown on a substrate with the addition of 10 -6 M jasmonic acid before infection were shown. In control plants, the expression of the HSR and TLP genes increased only after infection with potato virus X.

THE STUDY OF ANTHOCYANINS OF CORN WITH DARK GRAIN

In corn grains, anthocyanins pigments accumulate – belonging to the class of flavanoids, products of the secondary metabolism of plants and which are low molecular weight antioxidants. Numerous epidemiological studies have shown that the use of foods rich in anthocyanins leads to a significant reduction in diabetes, obesity, cardiovascular and oncological diseases. Compared to an equal amount of vegetables and fruits containing anthocyanins, more of them are present in the grain in bound form. Participating in the metabolism in the lower parts of the gastrointestinal tract, they have a beneficial effect on maintaining health. To analyze the total content and determine the composition of anthocyanins in grains of 21 samples of corn from the collection of the National Gene Bank of Azerbaijan, in order to identify promising samples in breeding to increase the content of anthocyanins, we used the method of high-performance liquid chromatography with reverse phase (HPLC) with spectrophotometric and mass spectrometric detection. The grains of the test samples identified mainly cyanidin-3-glucoside and pelargonidin-3-glucoside, as well as the isomeric products of their mono- and diacylation with malonic acid. Pelargonidin-3-glucoside derivatives prevailed in the grain extracts of some of the samples studied. Corn samples were selected as starting material for further breeding work to create local forms of corn with improved nutritional and therapeutic properties.

The Cutaneous Physiological Redox: Essential to Maintain but Difficult to Define.

Skin is a unique tissue, possessing extremely efficient protective and regulative mechanisms, similar only to the gut and lungs. These tissues serve as an interface with the environment and are exposed to stressors from both endogenous and exogenous sources. Interestingly, all these stressors lead downstream to a cellular production of reactive oxygen species (ROS) and other electrophiles, which, in turn could have deleterious outcomes for the living organism. Hence, such tissues should always maintain a “high-alert” condition in order to cope with these various insults. Nevertheless, a moderate production of ROS induced by stressors could actually be beneficial, although it is impossible to predict if and which exposure would lead to which outcome. Consequently, a parameter which would indicate the skin’s readiness to cope with continuously fluctuating conditions is required. It has been proposed that the redox status may serve as a suitable indicator. In this opinion manuscript, we argue that the redox status is a vague parameter that is difficult to characterized and quantify due to its extremely dynamic nature. The common convention that the redox status is composed solely of the balance between oxidants and reductants (ROS and antioxidants) is also thought-provoking. Since this parameter in vivo behaves in a dynamic and complex manner, it better fits the description of a process, rather than an individual parameter. We suggest that the homeostatic modulation of the physiological redox (PR) should be in focus, rather than the redox status parameter itself. It is further suggested that low molecular weight antioxidants (LMWA) are, in fact, rather insignificant concerning the PR maintenance, and that the major contributors to this delicate modulation are regulative, protein-based systems such as the protective phase II antioxidant enzymes. Moreover, we show that skin microbiome and cutaneous advanced lipid peroxidation end-products (ALEs) take part in sustaining the cutaneous PR homoeostasis via activation of the Nrf2–Keap1 protective pathway.

Показатели антиоксидантной системы и окислительного стресса побегов тритикале в условиях хлоридного засоления

Alterations in the activity of antioxidant enzymes (catalase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase), the content of low molecular weight antioxidants (ascorbic acid, glutathione, and proline), as well as indicators of oxidative stress (hydrogen peroxide, superoxide radical, lipid peroxidation –LPO) in the shoots of triticale (Triticosecale) under short-term (0-96 h) sodium chloride stress (120 mM) were studied with statistical methods: principal component analysis (PCA) and cluster analysis. The application of the PCA method did not always lead to definite results that could be unambiguously interpreted from the point of view of modern concepts in the field of plant physiology and biochemistry. At the same time, high values of the correlation coefficients between individual indicators did not at all reflect their biochemical interdependence. The results obtained allow us to conclude that, under conditions of short-term chloride stress in triticale shoots, the more important function of proline is associated, rather, with the maintenance of osmotic pressure inside the cell than with the role of a low-molecular antioxidant. The mutual positive values of the correlation coefficients (with respect to each other) of the activity of catalase, glutathione reductase, LPO, the content of hydrogen peroxide and superoxide indicate the unidirectionality of the detected alterations, which reflect their known biochemical relationship and the need for glutathione reductase to maintain a certain redox-state in plant cells. With cluster analysis it was shown that under conditions of short-term chloride stress in triticale shoots, the studied enzymes (catalase, ascorbate peroxidase, guaiacol peroxidase, and glutathione reductase) play a more significant role in neutralizing of reactive oxygen species, and maintaining the state of membranes, than low molecular weight antioxidants.

Exogenous Polyamines Only Indirectly Induce Stress Tolerance in Wheat Growing in Hydroponic Culture under Polyethylene Glycol-Induced Osmotic Stress.

The aim of the present study was to evaluate the effect of osmotic stress caused by polyethylene glycol (PEG) 6000 in hydroponic culture on wheat seedlings of drought-resistant Chinese Spring (CS) and drought-susceptible SQ1 cultivar, and to examine the alleviative role of exogenous polyamines (PAs) applied to the medium. The assessment was based on physiological (chlorophyll a fluorescence kinetics, chlorophyll and water content) as well as biochemical (content of carbohydrates, phenols, proline, salicylic and abscisic acid, activity of low molecular weight antioxidants) parameters, measured after supplementation with PAs (putrescine, spermidine and spermine) on the 3rd, 5th and 7th day of the treatment. The results indicate that PAs ameliorate the effects of stress, indirectly and conditionally inducing stress tolerance of wheat seedlings. In contrast to the susceptible SQ1, the resistant CS cultivar activated its protective mechanisms, adjusting the degree of their activation to the level of the stress, depending on the genetic resources of the plant. Increased accumulation of antioxidants in the resistant CS in response to stress after the application of PAs confirms the hypothesis that PAs are involved in the signaling pathway determining the antioxidative response and the tolerance of wheat plants to drought stress.

Comparative Study of Protective Action of Exogenous 2-Cys Peroxiredoxins (Prx1 and Prx2) Under Renal Ischemia-Reperfusion Injury.

The pathogenesis of ischemia-reperfusion (I/R) injuries is based on oxidative stress caused by a sharp increase in the concentration of free radicals, reactive oxygen species (ROS) and secondary products of free radical oxidation of biological macromolecules during reperfusion. Application of exogenous antioxidants lowers the level of ROS in the affected tissues, suppresses or adjusts the course of oxidative stress, thereby substantially reducing the severity of I/R injury. We believe that the use of antioxidant enzymes may be the most promising line of effort since they possess higher efficiency than low molecular weight antioxidants. Among antioxidant enzymes, of great interest are peroxiredoxins (Prx1–6) which reduce a wide range of organic and inorganic peroxide substrates. In an animal model of bilateral I/R injury of kidneys (using histological, biochemical, and molecular biological methods) it was shown that intravenous administration of recombinant typical 2-Cys peroxiredoxins (Prx1 and Prx2) effectively reduces the severity of I/R damage, contributing to the normalization of the structural and functional state of the kidneys and an almost 2-fold increase in the survival of experimental animals. The use of recombinant Prx1 or Prx2 can be an efficient approach for the prevention and treatment of renal I/R injury.