Activity Of Antioxidant System Research Articles

Silicon-induced alterations in the expression of aquaporins and antioxidant system activity in well-watered and drought-stressed oilseed rape

Progressing climate change necessitates the search for solutions of plant protection against the effects of water deficit. One of these solutions could be silicon supplementation. The aim of the study was to verify the hypothesis that silicon changes aquaporin expression and antioxidant system activity in a direction which may alleviate the effects of drought stress in oilseed rape. The accumulation of BnPIP1, BnPIP2-1-7 and BnTIP1;1 aquaporins and the expression of their genes, the level of catalase, superoxide dismutase activities and hydrogen peroxide content as well as total non-enzymatic antioxidant activity were analyzed in leaf tissue from control and silicon-treated oilseed rape plants growing under well-watered and drought conditions. Silicon was applied in two forms – pure silicon and a silicon complex. It was shown that under drought conditions, both pure silicon and the silicon complex (with Fe) significantly increased the accumulation of aquaporins and improved the activity of enzymatic and non-enzymatic components of the antioxidant system, while under well-watered conditions, these effects were observed only in the case of the silicon complex. The presented study proves that silicon supplementation in oilseed rape improves the regulation of water management and contributes to the protection against oxidative stress caused by drought.

Traffic noise induces oxidative stress and phytohormone imbalance in two urban plant species

Traffic noise pollution is one of the major environmental concerns in crowded cities worldwide. The objective of the present study was to investigate the effects of traffic noise on growth, hormonal balance, oxidative damage, and activity of antioxidant systems in two urban plant species, Tagetes patula and Salvia splendens. Each of the plant species were equally divided into 2 groups (control and traffic noise treatment) and each group was grown under identical controlled conditions in two separate growth chambers for two months. Traffic noise was recorded during peak traffic hours in a highly congested area of the city. Frequency analysis of traffic noise was conducted on the samples during the recording process. Plants in the traffic noise treatment group were exposed to 16 h of road traffic noise each day for a total of 15 days, while the control group was kept under complete silence. Traffic noise exposure led to significant decrease in growth indices of both plant species. The content of H2O2 and malondialdehyde (MDA) significantly increased upon traffic noise treatment in both species, followed by an increase in DPPH (2,2-diphenyl-1-picrylhydrazyl) anti-oxidant activity and the activity of antioxidant enzymes including catalase, peroxidase, and ascorbate peroxidase. Road traffic noise significantly reduced the content of phytohormones including zeatin, salicylic acid, indole-3-acetic acid, and gibberellic acid. On the other hand, the content of stress-related hormones including abscisic acid and jasmonic acid significantly increased in response to road traffic noise in both species. Based on our results, daily traffic noise can negatively affect growth and physiology of plants by inducing of oxidative damage and interfering with hormonal balance.

Anticarcinogenic activity of methanol extract of Melastoma malabathricum leaves is attributed to the presence of phenolics compounds and the activation of endogenous antioxidant system

Melastoma malabathricum (M. malabathricum) extracts have been reported to exert various pharmacological activities including antioxidants, anti-inflammatory and antiproliferative activities. The objective of the present study was to determine the anticarcinogenic activity of its methanol extract (MEMM) against the azoxymethane (AOM)-induced early colon carcinogenesis in rats. Rats were randomly assigned to five groups (n=6) namely normal control, negative control, and treatment (50, 250 or 500 mg/kg of MEMM) groups. Colon tissues were harvested for histopathological analysis and endogenous antioxidant system determination. MEMM was also subjected to HPLC analysis. Findings showed that MEMM significantly (p<0.05) reversed the AOM-induced carcinogenicity by: i) reducing the formation of aberrant crypt foci (ACF) in colon tissues, and; ii) enhancing the endogenous antioxidant activity (catalase, superoxide dismutase and glutathione peroxidase). Moreover, various phenolics has been identified in MEMM. In conclusion, MEMM exerts the in vivo anticarcinogenic activity via the activation of endogenous antioxidant system and synergistic action of phenolics.

ALTERATIONS OF ANTIOXIDANT ENZYMES DURING ALLOXAN-INDUCED DIABETES (EXPERIMENTAL STUDY)

Our study aimed to assess the activity of the blood antioxidant system in the animal model of alloxan-induced diabetes in rats.Diabetes in rats was induced diabetes by a single intraperitoneally injection of freshly prepared 12% aqueous alloxan solution ( 200 mg/kg). The glucose level was measured after 1, 2, 3, 10, 15, and 30 days from alloxan administration. The study included only those rats with blood glucose levels above 250 mg/dl on the 2nd day after alloxan administration.We investigated the activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase (Cat) in the blood serum.The results of the studies show that the activity of enzymatic antioxidant systems in rats' blood sharply increased during the first 3 days after injection of alloxan. That may be due to the compensatory reaction of the body in response to alloxan-induced oxidative stress. Afterwards, the activity of SOD and Cat decreased, which may be due to the utilization of antioxidant proteins in the detoxification process of ROSs, their glycation and decreased level of the protein synthesis in the body at the intensive hyperglycemia and oxidative stress conditions.

Resistance to H2O2-induced oxidative stress in human cells of different phenotypes

Application of genetically encoded biosensors of redox-active compounds promotes the elaboration of new methods for investigation of intracellular redox activities. Previously, we have developed a method to measure quantitatively the intracellular concentration of hydrogen peroxide (H2O2) in living cells using genetically encoded biosensor HyPer. In the present study, we refined the method and applied it for comparing the antioxidant system potency in human cells of different phenotypes by measuring the gradient between the extracellular and cytoplasmic H2O2 concentrations under conditions of H2O2-induced external oxidative stress. The measurements were performed using cancer cell lines (K-562 and HeLa), as well as normal human cells – all expressing HyPer in the cell cytoplasm. As normal cells, we used three isogenic lines of different phenotypes – mesenchymal stem/stromal cells (MSCs), induced pluripotent stem cells (iPSCs) derived from MSCs by reprogramming, and differentiated iPSC progenies with the phenotype resembling precursory MSCs. When exposing cells to exogenous H2O2, we showed that at low oxidative loads (<50 μM of H2O2) the gradient depended on extracellular H2O2 concentration. At high loads (>50 μM of H2O2), which caused the exhaustion of thioredoxin activity in the cell cytoplasm, the gradient stabilized, pointing out that it is the functional status of the thioredoxin-depended enzymatic system that drives the dependence of the H2O2 gradient on the oxidative load in human cells. At high H2O2 concentrations, the cytoplasmic H2O2 level in cancer cells was found to be several hundred times lower than the extracellular one. At the same time, in normal cells, extracellular-to-intracellular gradient amounted to thousands of times. Upon reprogramming, the potency of cellular antioxidant defense increased. In contrast, differentiation of iPSCs did not result in the changes in antioxidant system activity in the cell cytoplasm, assuming that intensification of the H2O2-detoxification processes is inherent to a period of early human development.

Evaluation of Dose-Dependent Obesity and Diabetes-Related Complications of Water Chestnut (Fruit of Trapa japonica) Extracts in Type II Obese Diabetic Mice Induced by 45% Kcal High-Fat Diet.

Background and Objectives: The currently used pharmacological agents for metabolic disorders such as type II diabetes have several limitations and adverse effects; thus, there is a need for alternative therapeutic drugs and health functional foods. Materials and Methods: This study investigated the pharmacological effects of water chestnut (fruit of Trapa japonica) extracts (WC: 50–200 mg/kg) for type II diabetes using a 45% Kcal high-fat diet (HFD)-fed type II obese diabetic mice model for a period of 84 days, and the effects were compared to those of metformin (250 mg/kg). Results: Increases in body weight, serum biochemical indices such as triglycerides, low-density lipoprotein, and blood urea nitrogen, increases in antioxidant defense system enzymes such as catalase, superoxide dismutase, and glutathione, and mRNA expressions (such as AMPKα1 and AMPKα2) in the liver tissue and mRNA expressions (such as AMPKα2 mRNA, leptin, and C/EBPα) in the adipose tissue were observed in the HFD control group. The WC (50 mg/kg)-administered group showed no significant improvements in diabetic complications. However, HFD-induced obesity and diabetes-related complications such as hyperlipidemia, diabetic nephropathy, nonalcoholic fatty liver disease (NAFLD), oxidative stress, activity of antioxidant defense systems, and gene expressions were significantly and dose-dependently inhibited and/or normalized by oral administration of WC (100 mg/kg and 200 mg/kg), particularly at a dose of 100 mg/kg. Conclusions: The results of this study suggest that WC at an appropriate dose could be used to develop an effective therapeutic drug or functional food for type II diabetes and various associated complications, including NAFLD.

Role of melatonin in autism spectrum disorders in a male murine transgenic model: Study in the prefrontal cortex.

Autism spectrum disorders (ASDs) are a group of clinically heterogeneous neurodevelopmental disorders sharing common features related to impaired social and communication abilities in addition to stereotyped behaviors. ASD patients present encephalic morphological, physiological, and biomolecular alterations with low levels of melatonin due to alterations in its pathways. Therefore, even if ASDs have traditionally been framed as behavioral disorders, several lines of evidence are accumulating that ASDs are characterized by certain anatomical and physiological abnormalities, including oxidative stress and inflammation in peripheral biomarkers, but likewise present in human brain tissue also characterized by alterations in synaptic remodeling and neuromodulation. Melatonin has also protective and antioxidant properties, so we can therefore hypothesize that alterations in melatonin's pathways may be one of the causes of the symptomatology of autism. The aim of the present study was to analyze the beneficial effect induced by melatonin administration and its possible mechanism of action in a transgenic mouse model of autism, immediately after weaning. The male mice were daily treated per os with melatonin (10mg/Kg/day) or vehicle for 8weeks starting from the sixth week of life. The antioxidant modulation, the GABAergic/glutamatergic impairment, and the synaptic remodeling in the prefrontal cortex have been evaluated. Social and repetitive behaviors were also evaluated. The behavioral results showed no statistical evidences, instead the immunohistochemical results indicated the ability of melatonin to promote the activity of antioxidant system, the GABAergic/glutamatergic equilibrium, and the synaptic remodeling. The results show that melatonin may be a possible adjuvant therapeutic strategy in ASDs.

Thioredoxin Reductase 1 Modulates Pigmentation and Photobiology of Murine Melanocytes in vivo

Pigment-producing melanocytes overcome frequent oxidative stress in their physiological role of protecting the skin against the deleterious effects of solar UV irradiation. This is accomplished by the activity of several endogenous antioxidant systems, including the thioredoxin antioxidant system, in which thioredoxin reductase 1 (TR1) plays an important part. To determine whether TR1 contributes to the redox regulation of melanocyte homeostasis, we have generated a selective melanocytic Txnrd1-knockout mouse model (Txnrd1mel‒/‒), which exhibits a depigmentation phenotype consisting of variable amelanotic ventral spotting and reduced pigmentation on the extremities (tail tip, ears, and paws). The antioxidant role of TR1 was further probed in the presence of acute neonatal UVB irradiation, which stimulates melanocyte activation and introduces a spike in oxidative stress in the skin microenvironment. Interestingly, we observed a significant reduction in overall melanocyte count and proliferation in the absence of TR1. Furthermore, melanocytes exhibited an elevated level of UV-induced DNA damage in the form of 8-oxo-2'-deoxyguanosine after acute UVB treatment. We also saw an engagement of compensatory antioxidant mechanisms through increased nuclear localization of transcription factor NRF2. Altogether, these data indicate that melanocytic TR1 positively regulates melanocyte homeostasis and pigmentation during development and protects against UVB-induced DNA damage and oxidative stress.

Proteomic changes in mango fruit peel associated with chilling injury tolerance induced by quarantine hot water treatment

The aim of this study was to identify proteins associated with the chilling injury (CI) tolerance induced by hot water treatment (HWT) in ‘Keitt’ mango fruit. A comparative proteomic analysis was performed between fruit with HWT (46.1 °C, 90 min) and non-treated (Control) after cold storage (0 and 20 d at 5 °C) and ripening (7 d at 21 °C); the expression of genes encoding some selected proteins was analyzed by real-time PCR. Twenty-six proteins were differentially expressed after HWT, 36 after 20 days of cold storage and 33 after ripening. Polypeptides with higher accumulation in HWT fruit included eleven heat shock proteins (HSPs), eight enzymes of the energetic metabolism (ACO1, ACO2, GAPDH-1, GAPDH-2, ADH, SDH, ADK, and ACAA) and seven of the secondary metabolism (PAL, CHS, CHI, PDS, HPPD, IsoCH, and PPO), four antioxidant enzymes (CAT, POD, Prx, and APX,), four proteins involved in hormone metabolism (P-gp2, ARF, ERF, and GA3ox1), two pathogenesis-related proteins (β-Glu and 2 s alb), four enzymes of cell wall metabolism (EGase, β-Gal, Rab11 and αMan), and three proteins involved in chloroplast metabolism (RuBisCo, PDX1, and rpl2). Non-treated fruit showed higher accumulation of polyphenol oxidase and alcohol dehydrogenase, suggesting a higher oxidation of phenols and lower efficiency in energy production. The CI tolerance induced by the quarantine HWT in mango fruit appears to be associated with the prevention of protein denaturation, the maintenance of the membrane functionality and energy efficiency, the activation of antioxidant and defense systems, the preservation of cell wall metabolism, and the synthesis of secondary metabolites.

Effect of 5-Azacitidine Treatment on Redox Status and Inflammatory Condition in MDS Patients.

This study focused on the impact of the treatment with the hypomethylating agent 5-azacitidine on the redox status and inflammation in 24 MDS patients. Clinical and genetic features of MDS patients were recorded, and peripheral blood samples were used to determine the activity of the endogenous antioxidant defense system (superoxide dismutase, SOD; catalase, CAT; glutathion peroxidase, GPx; and reductase, GRd, activities), markers of oxidative damage (lipid peroxidation, LPO, and advanced oxidation protein products, AOPP). Moreover, pro-inflammatory cytokines and plasma nitrite plus nitrate levels as markers of inflammation, as well as CoQ10 plasma levels, were also measured. Globally, MDS patients showed less redox status in terms of a reduction in the GSSG/GSH ratio and in the LPO levels, as well as increased CAT activity compared with healthy subjects, with no changes in SOD, GPx, and GRd activities, or AOPP levels. When analyzing the evolution from early to advanced stages of the disease, we found that the GPx activity, GSSG/GSH ratio, LPO, and AOPP increased, with a reduction in CAT. GPx changes were related to the presence of risk factors such as high-risk IPSS-R or mutational score. Moreover, there was an increase in IL-2, IL-6, IL-8, and TNF-α plasma levels, with a further increase of IL-2 and IL-10 from early to advanced stages of the disease. However, we did not observe any association between inflammation and oxidative stress. Finally, 5-azacitidine treatment generated oxidative stress in MDS patients, without affecting inflammation levels, suggesting that oxidative status and inflammation are two independent processes.

Treatment efficacy of Thunbergia laurifolia, Curcuma longa, Garcinia mangostana, and Andrographis paniculata extracts in Staphylococcus aureus-induced rabbit dermatitis model.

Background and Aim:Dermatitis is a soft-tissue infection caused by Staphylococcus aureus. The recurrence of inflammatory skin is linked to clinical manifestations. Anti-inflammatory cytokines, which are essential for tissue damage, are released by bacteria through skin tissues. Oxidative stress causes inflammatory cells to necrotize and reduces their antioxidant profile, resulting in toxic damage to surrounding tissues. Although studies on the antibacterial effects of Thunbergia laurifolia Lindl., Curcuma longa L., Garcinia mangostana L., and Andrographis paniculata (Burm.). Bacterial infection of S. aureus have been conducted, most of these studies have been in vitro and were not related to the rabbit model. In addition, anti-inflammatory and antioxidant studies need to be evaluated. Thus, this study aims to compare the antibacterial, anti-inflammatory, and antioxidant properties of four local herbs with a standard antibiotic in S. aureus-induced rabbit dermatitis model.Materials and Methods:The skin of New Zealand white rabbits were artificially wounded using a sterile blade and then infected with S. aureus. The rabbits were divided into seven groups, each with three rabbits (Total 21 rabbits): The first group was the no infection group (no infection and no treatment with scarification), the second group was the no treatment group (S. aureus infection of the wound but no treatment), and the other five treated groups were T. laurifolia, C. longa, G. mangostana, A. paniculata, and bacitracin cream, all of which involved wound infection and treatments. The treatment lasted for 7 days. The antibacterial, anti-inflammatory, and antioxidant properties after treatment were measured.Results:The efficacy of T. laurifolia, C. longa, G. mangostana, and A. paniculata was similar to that of an antioxidant and free radical scavenging property. The bacterial infection process gradually reduced the activities of antioxidant systems (i.e., enzymatic levels and gene expressions) and total glutathione. However, the activities of the antioxidant system were steadily increased when treated with herbal extracts. During bacterial invasion of the skin, the concentration of thiobarbituric acid reactive molecules, the level of lipid peroxidation, and the expression of anti-inflammatory cytokine genes were increased. All these were decreased when herbal extracts were used to treat the lesion.Conclusion:It can be concluded that T. laurifolia, C. longa, G. mangostana, and A. paniculate extract have antibacterial, anti-inflammatory, and antioxidant properties and are effective antibacterial agents. G. mangostana is the most effective herbal extract for antidermatitis and has the potential to be used as an alternative topical treatment.

EFFECT OF RADIATION ON AGING PROCESSES AND TELOMERE LENGTH.

Telomeres are the ending areas of chromosomes - protective «caps» that ensure the stability of chromosomes. Telomere shortening is one of the most important biological signs of aging and is involved in cellular aging and the «mitotic clock» mechanism. One of the known mechanisms of the impact of radiation on the aging process is damage to telomeres by free radicals. Oxidative stress has a toxic effect on telomere length. The increase in free radicals occurs under the action of both ionizing and nonionizing radiation, although antioxidant mechanisms are often able to neutralize harmful free radicals. Low doses of nonionizing and ionizing radiation even cause the activation of antioxidant systems, however, when the body is exposed to radiation at a high dose or for a long time, or if pathological processes with oxidative stress occur in the body, damage to cells becomes more noticeable, and aging processes accelerate. Maintaining telomere length and a normal rate of aging is important for health. In this review, we want to discuss the role of ionizing and nonionizing radiation in cellular aging, in particular, in the shortening of telomere length.

Effect of sodium and potassium humate in adaptive reaction of Zea mays under radiation stress

The effect of sodium and potassium humate on the activity of antioxidant system and photosynthetic pigment concentration of irradiated seeds was studied. The treatment of maize seed with 0.005% and 0.001% solutions of sodium and potassium humate caused significant reduction in processes initiated by radiation. A positive effect of sodium and potassium humate solutions on the amount of malon dialdehyde, chlorophyll pigments and carotenoids, fluorescent characteristics (the maximum quantum yield of PSII (photosystem II) in seedlings obtained from gamma-irradiated maize seeds was revealed.

Оксидантно-антиоксидантна система крові при експериментальній емфіземі легень

Abstract. Bronchial asthma ( BA) is one of the most common diseases of the human respiratory organs and occupies one of the leading places both in the terms of the prevalence and the severity of manifestations. With a long duration of BA, concomitant smoking, the irreversible bronchial obstruction formation, some patients develop pulmonary emphysema. The pathogenesis of pulmonary emphysema is multifactorial and consists in the mechanisms of oxidative stress, imbalance of the protease/antiprotease system, activation of inflammatory cells and production of inflammatory mediators. Oxidative stress is one of the main processes in the formation of pulmonary emphysema, but its exact mechanisms, which could be targeted by pathogenetic therapy, have not yet been studied. The study of pulmonary emphysema pathogenesis in patients is often complicated due to the influence of a large number of random combinations of the various factors. One way to avoid such influence is experiment. The aim is to study the nature of changes in the oxidant-antioxidant system of the blood in the experimental pulmonary emphysema. Methods. Experimental studies were carried out on 24 mature, outbred white rats weighing 180-200 g, which were kept on a standard vivarium diet. To assess the intensity of lipid peroxidation in the animal blood, the content of its final product, malondialdehyde, was determined. The the antioxidant system activity was assessed by the content of ceruloplasmin and catalase activity in the blood. Results. The results of the conducted studies indicate a significant increase in the level of malondialdehyde in the blood in conditions of experimental pulmonary emphysema by 30 %. At the same time, a decrease in the content of ceruloplasmin in the blood by 20 % and catalase activity by 29 % was revealed. Conclusions. In experimental pulmonary emphysema, enhanced generation of malondialdehyde leads to the development of oxidative stress and intoxication, disruption of the functions of the antioxidant and antiperoxide defense systems of the body, as evidenced by the significant decrease in the level of ceruloplasmin and catalase activity in the blood.

Sitosterol-mediated Antioxidant Regulation to Enhance Heat Tolerance in Creeping Bentgrass

Heat stress symptoms in cool-season plants are characterized by loss of chlorophyll (Chl) and membrane stability, as well as oxidative damage. The objectives of this study were to determine whether foliar application of β-sitosterol, a naturally occurring plant metabolite, may promote heat tolerance by suppressing heat-induced leaf senescence as indicated by the maintenance of healthy turf quality (TQ), and Chl and membrane stability; and to determine its roles in regulating antioxidant metabolism in creeping bentgrass (Agrostis stolonifera). ‘Penncross’ plants were exposed to heat stress (35/30 °C day/night) optimal temperature conditions (nonstressed control, 22/17 °C day/night) for a duration of 28 days in environment-controlled growth chambers. Plants were foliar-treated with β-sitosterol (400 µM) or water only (untreated control) before heat stress, and at 7-day intervals through 28 days of heat stress. Plants treated with β-sitosterol had significantly greater TQ and Chl content, and significantly less electrolyte leakage (EL) than untreated controls at 21 and 28 days of heat stress. Application of β-sitosterol reduced malondialdehyde (MDA) content significantly at 21 and 28 days of heat stress, and promoted the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) from 14 through 28 days of heat stress. β-Sitosterol effectively improved heat tolerance through suppression of leaf senescence in creeping bentgrass exposed to heat stress in association with the alleviation of membrane lipid peroxidation and activation of the enzymatic antioxidant system.

Enzymatic antioxidant defense system and ALA-D enzyme activity in soybean Enlist™ line

Enlist™ technology confers resistance to 2,4-D herbicides, glyphosate, and ammonium glufosinate for soybeans. However, the application of herbicides to plants can generate stress, even in resistant crops. Thus, here we evaluated whether the application of herbicides in transgenic soybean farms, resistant to these herbicides, adversely affects the activity of antioxidant enzymes and porphobilinogen formation by delta-aminolevulinate dehydratase (ALA-D) activity. At seven days after herbicide application, the aerial part of the plants was collected and used to determine the activity of antioxidant enzymes as catalase, ascorbate peroxidase, and guaiacol peroxidase, such as lipid peroxidation levels and the activity of the ALA-D enzyme. At seven days after herbicide application, the aerial part of plants was collect and used to determine the activity of antioxidant enzymes, such as catalase, ascorbate peroxidase and guaiacol peroxidase, as well as the levels of lipid peroxidation and the activity of the ALA-D enzyme. The activity of important antioxidant enzymes involved in the scavenging of reactive oxygen species (ROS) was increased in the soybean cultivar with the Enlist™ technology, while no severe damage to lipids was detected. However, the activity of ALA-D was inhibited, which could potentially impair the formation of porphobilinogen and decrease photosynthetic efficiency. Thus, these results indicate that herbicides can affect the activity of ROS-scavenging enzymes even in transgenic, herbicide-resistant plants.

Gastroprotektivne karakteristike krioprezerviranog ekstrakta placente kod kombinovanog delovanja niskih temperatura i inhibicije ciklooksigenaze

Introduction. Non-steroidal anti-inflammatory drugs (NSAIDs) are ranked first among the world's effective anti-inflammatory and analgesic drugs with anticipated side effects. That is why the prevention of development of adverse reactions associated with NSAIDs, in particular, of those related to their ulcerogenicity, remains a serious global problem. Aims. To characterize the mechanisms of gastrocytoprotective activity of cryopreserved placenta in combined action of low temperatures and diclofenac sodium. Material and methods. The study was performed on 42 male rats weighing 200-220 g. Acute diclofenac sodium-induced gastropathy was reproduced by a single injection of the latter in rats at the dose of 50 mg/kg. The content of malonic dialdehyde, catalase activity, prostaglandin synthase activity and the content of nitrogen monoxide metabolites in homogenates of gastric mucosa were determined by spectrophotometric method. Results and discussion. The study showed that prophylactic administration of placental cryoextract in rats with diclofenac sodium-induced gastropathy is associated with increased activity of antioxidant system in gastric mucosa as demonstrated by an elevated catalase activity by 40.0% as compared with control rats. Modulation of antioxidant-prooxidant homeostasis is believed to be one of the principal mechanisms of gastrocytoprotective action in combined action of low temperatures and cryoextract of the placenta. This is shown by a statistically significant (p &lt; 0.05) 2.2-fold increase of antioxidant-prooxidant index in the study group as compared with rats with diclofenac sodium-induced gastropathy. Administration of placental cryoextract was found to increase prostaglandin synthase activity in rats with diclofenac sodium-induced gastropathy by two times as compared with control rats, which would reduce iatrogenic prostaglandin deficiency in gastric mucosa. Also, the combined action of low temperatures and of placenta cryoextract was associated with a statistically significant (p &lt; 0.05) increase in the level of metabolites of nitrogen monoxide (by 70.1%) as compared with rats with diclofenac sodium-induced gastropathy. Conclusions. Modulation of prooxidant-antioxidant homeostasis in gastric mucosa and increase in contents of nitrogen monoxide metabolites and prostaglandin synthase activity are the leading mechanisms of gastroprotective activity of cryopreserved placental extract in diclofenac sodium-induced gastropathy.

Detection of Reactive Oxygen Species in Human Neutrophils Under Various Conditions of Exposure to Galectin.

Reactive oxygen species (ROS) have been extensively studied in biology in the past years. This class of molecules can be derived from endogenous sources (e.g., phagocytic cells as neutrophils, eosinophils, monocytes, macrophages, and organelles as mitochondria and peroxisomes) and participate in physiological and pathological conditions. The beneficial and harmful effects of ROS depend on redox regulation, which establishes the balance between their production and the activity of antioxidant systems to prevent oxidative stress in vivo. Neutrophils are the immune effectors most well depicted with an intense oxidative burst in response to tissue inflammation. Several proteins and members of the galectin family are involved in this fine modulation of ROS production by neutrophils. Interestingly, studies have indicated that Galectin-1 (Gal-1) can up- or downregulate ROS production by neutrophils even when exposed to N-formyl-Met-Leu-Phe (fMLP) or Phorbol Myristate Acetate (PMA), both of which are potent neutrophil stimulants that trigger high levels of ROS production. Similarly, Galectin-3 (Gal-3) induces ROS in neutrophils from a sterile or nonsterile inflammatory environment, possibly creating a negative loop that could control ROS production. Besides, superoxide production is also induced by Galectin-8 (Gal-8) and Galectin-9 (Gal-9) in neutrophils but in a different manner. We describe herein the luminol and lucigenin-dependent chemiluminescence technique by using a luminometer as a method of assessment to measure ROS production by human neutrophils isolated and exposed to purified human recombinant Gal-1. The protocol described herein could be applied for the investigation of the role of other galectins in the modulation of ROS production by neutrophils.

Stress and use of herbicides in field crops

When herbicides are combined under natural conditions or applied in stress conditions (drought, for instance), the efficiency of their action may decrease which results in considerable yield losses. The reason thereto is that another herbicide or stressor can trigger the adaptation mechanism in weed plants, and they survive, resulting in weed infestation. In particular, it applies to such herbicides as acetyl-CoA-carboxylase inhibitors or so- called graminicides, which are effective only for grass weeds control. The efficiency of this groups of herbi- cides is heavily dependent on the environment and often decreases when combined with herbicides, efficient against dicotyledon weeds. It turns out that this occurs due to the fact their final phytotoxicity is not determined at the level of the site of action (herbicide target) but depends on the stage of herbicide-induced pathogenesis – processes, occurring due to the interaction between the herbicide and its site of action. The stress response of the weeds may make its contribution into herbicide-induced pathogenesis. Plants are known to respond to the action of various abiotic stressors in the form of non-specific stress response and depending on the intensity and duration of the stressor’s action, a plant either adapts or dies. At present there are sufficient data, demonstrating that programmed cell death (PCD) is involved in the herbicide-induced pathogenesis. Reactive oxygen species (ROS) induce PCD in specific classes of herbicides. The participation of ROS and PCD in herbicide-induced pathogenesis allows for targeted effects on the phytotoxic action of herbicides, for instance, via combined application of herbicides with possible PCD inducers and prooxidants. The confirmation of the role of non- specific response in the development of phytotoxic action of herbicides is found in the phenomena of cross- adaptation (activation of antioxidant defense) and cross-synergism (activation of oxidative stress) under the application of herbicides. Based on our own research and literature data, the importance of cross-adaptation and cross-synergism in applying herbicides in drought conditions and to determine the nature of the interac- tion in herbicide complexes is discussed. In particular, the review discusses the reduction of phytotoxicity of the ACCase herbicides due to the phenomenon of cross-adaptation in drought conditions and in combination with herbicides, which are acetolactate synthase inhibitors. The results of investigations were presented about the reduction of antagonism in the mixtures of herbicides, which are ACCase and ALS inhibitors, because of the use of substances with prooxidant properties, as well as the inhibitor of the antioxidant enzyme superoxide dismutase. On the other hand, we analyzed the possibility of increasing the phytotoxic effect of herbicides, ACCase inhibitors, in combination with herbicides with prooxidant properties – inhibitors of electron transport in Photosystem 2 (FS 2) chloroplasts and protoporphyrinogen oxidase (PROTOX) inhibitors. It became the foundation for the elaboration of efficient herbicide compositions for wheat and onion fields. While combining herbicides, the issue of synergism is becoming relevant due to the problem of the spread of target-site resis- tance, since, to prevent this type of resistance, it is necessary to combine herbicides with different mechanisms of phytotoxicity. The presented data demonstrate that the increased activity of antioxidant defense systems, which is the result of a long process of evolutionary adaptation of weeds to the action of abiotic stressors, is an element of non-target-site-based resistance to herbicides. Possible ways to prevent the negative impact of non-specific stress response on the efficiency of herbicides, as well as the prospects of the chemical method of weeds control are discussed.

Antioxidant, molecular docking and computational investigation of new flavonoids

Flavonoids are a group of polyphenolic compounds diverse in structure, biological and pharmacological functions possessing antioxidant potential. New flavonoids (3a, 3b, 4a, 4b, 5a and 5b) were synthesized by acid catalysed condensation of bromo‑benzaldehydes and 2,5-dihydroxyacetophenone. In vitro antioxidant potential of synthesized compounds was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) cation (ABTS+) radical scavenging, iron chelating, iron reducing and phosphomolybdenum activity. The results revealed that DPPH radical scavenging and ABTS+scavenging activity of compounds 3a and 3b (chalcones) were better than reference compounds i.e., trolox and ascorbic acid. Furthermore, molecular docking was performed to check the affinity of flavonoids with Keap1 for the activation of antioxidant defense system of body and computational study was carried out by DFT approach using B3LYP functional and 6–31G** basis set. All the compounds showed better results compared to the reference compounds and molecular docking studies supported the computational results.