Activity Of Antioxidant System Enzymes Research Articles

Reactive Oxygen Species as Potential Drivers of the Seed Aging Process.

Seeds are an important life cycle stage because they guarantee plant survival in unfavorable environmental conditions and the transfer of genetic information from parents to offspring. However, similar to every organ, seeds undergo aging processes that limit their viability and ultimately cause the loss of their basic property, i.e., the ability to germinate. Seed aging is a vital economic and scientific issue that is related to seed resistance to an array of factors, both internal (genetic, structural, and physiological) and external (mainly storage conditions: temperature and humidity). Reactive oxygen species (ROS) are believed to initiate seed aging via the degradation of cell membrane phospholipids and the structural and functional deterioration of proteins and genetic material. Researchers investigating seed aging claim that the effective protection of genetic resources requires an understanding of the reasons for senescence of seeds with variable sensitivity to drying and long-term storage. Genomic integrity considerably affects seed viability and vigor. The deterioration of nucleic acids inhibits transcription and translation and exacerbates reductions in the activity of antioxidant system enzymes. All of these factors significantly limit seed viability.

EFFECT OF ACUTE INTOXICATION WITH AFLATOXIN B1 ON THE ANTIOXIDANT SYSTEM IN RED BLOOD CELLS AND LUNG CELLS OF WHITE RATS

Contamination of agricultural products with mycotoxins is a widespread phenomenon that is manifested in many countries. Among mycotoxins, which significantly affect human and animal health, aflatoxins produced by Aspergillus micromycetic fungi (mainly A. flavus) are of serious concern because of their high toxicity and carcinogenicity. The aim of our study was to investigate the effect of aflatoxin B1 (AFB1) on intracellular metabolism in laboratory animals. The dynamics of the lipid peroxidation (LPO) and activities of antioxidant system enzymes (superoxide dismutase, glutathione peroxidase, and glutathione reductase) in lung cells and erythrocytes of white rats were analyzed within 14 days after administration of AFB1 (dose 1/10 LD50). The results of the study have shown the activation of the LPO processes and a decrease in the activity of enzymes of the antioxidant system in the cells of rats of the experimental groups. In general, the obtained results suggest the development of oxidative stress in the lungs cells and erythrocytes of animals under the influence of aflatoxin B1.

The effects of CuO nanoparticles on wheat seeds and seedlings and Alternaria solani fungi: in vitro study

The paper analyses the influence of copper oxide nanoparticles (CuO NPs) dispersions (0.01…1 g/L) on seed germination capacity, development and biochemical status of wheat seedlings. Also the paper presents the results of the in vitro study of effect produced by CuO NPs (0.001…0.1 g/L) on Alternaria solani fungi. The most pronounced combined positive effect on the studied parameters has been observed at 0.01 g/L concentration of copper oxide nanoparticles. Improvement of germination capacity by 14.5 per cent and a twofold increase in the root and stem length compared to the control group have been recorded at this concentration. At higher NPs content in the dispersion stimulation was combined with toxic effects (decrease of root length). A slight impact of NPs on the activity of antioxidant system enzymes has been registered at concentrations of 0.01 g/L and 1 g/L. CuO NPs at 0.001…0.1 g/L concentrations inhibited Alternaria solani mycelium development and spore germination by 34-50 per cent, but the ionic solution of CuCl2·6H2O displayed higher efficacy. The obtained results can be used for development of new micronutrient fertilizers and crop protection agents based on copper nanoparticles.

CHANGES OF THE INDICES OF LIPID PEROXIDATION AND ANTIOXIDANT SYSTEM IN LUNGS UNDER CONDITIONS OF EXPERIMENTAL BRONCHIAL ASTHMA WITH CHRONIC PERIODONTITIS AND THEIR CORRECTION BY TIOTRIASOLIN

In this paper, it has been shown that the model process of bronchial asthma (BA) with chronic periodontitis (CP) is accompanied by an increase of lipid peroxidation system indices (LPO) compared with the control group: the content of malonic dialdehyde and conjugated dienes; initial increase with further decrease in the activity of the AOS enzymes: superoxide dismutase, catalase, the content of ceruloplasmin in the lungs of guinea pig males on the 4th, 18 th, 25 th day of the experiment. These changes indicate the development of oxidative stress in the formation of BA with CP and the corrective effect of thiotriazolin.Objective. Determination of some indices of lipid peroxidation (LPO) and antioxidant system (AOS) in the lungs of the guinea pigs in the modeling process of BA with CP on 4th, 18th, 25th day of the experiment and effect of thiotriazoline on them.Material and methods. Experiments were conducted on 50 guinea pigs (males), with body weight 0,25-0,27 kg. Animals were divided into five groups, ten animals in each. Intact guinea pigs constituted the first group. Animals with experimental BA at CP without thiotriazoline correction constituted the second, third, fourth group respectively on the 4th, 18th, 25th day of the experiment before the correction, fifth group included animals with BA at CP on the 25th day of simulation of the disease after correction with thiotriazoline. Experimental BA was reproduced by V. I. Babych method. Chronical periodontitis was reproduced by O. N. Voskresens'kyy method. The level of conjugated dienes was determined by the method of V. B. Havrylov and M. I. Myshkorudna; the level of malondialdehyde was determined by the method of E. N. Korobeynikov: superoxide dismutase level activity was determined by the method of R. Fried; the level activity of katalase was determined by the method of B. Holmes, C. Masters; ceruloplasmin level activity was determined by the method of V. G. Kolb and V. S. Kamyshnikov. Statistical methods of processing the results of the study were processed by the method of variation statistics using Student's criterion.Results and discussions. The results of the studies showed changes in the parameters of the prooxidant-antioxidant system depending on the periods of the formation of BA with CP without correction by thiotriazoline: an increase in the levels of LPO in all of the days of the experiment, the initial increase with a further decrease in the activity of the AOS enzymes; decreasing of levels of LPO indices and increase in activity of AOS enzymes after correction by thiotriazolinom.Conclusions. The obtained results indicate significant changes in the parameters of the prooxidant-antioxidant system in the lungs of experimental animals with BA and CP and the antioxidant effect of thiotriazolin.

The effect of endodontic filling agents on the activity of the regeneration processes of bone tissue in the experiment

Introduction. Highly important is to regenerate the inflammatory destructive processes of bone tissue outside the apical area of the tooth that would optimize reparative bone formation, mineralization of tooth tissues, restoration of periodontal function and stability of tooth to occlusive loads, especially with acquired extensive root apex. Low efficiency of endodontic treatment led to the searching of the new osteotropic drugs of osteoconductive action and biorevitalization to stimulate the repairing and regeneration of tissues outside the apical area and dense obturation of the apex of the tooth root.Aim. of our research was to determine the dynamics of reparative processes in the bone tissue under the influence of drugs and compositions for endodontic treatment based on an analysis of indicators of a mineral metabolism, marker enzymes and an activity of antioxidant system and lipid peroxidation.Material and Methods. An experiment was conducted on 120 white rats. It was created a bone defect, which was filled with studied biomaterials or left with a blood clot. From the experiment the rats were taken out on 14 and 90 day. In homogenates of bone tissue it was examined the activity of lysosomal enzymes — alkaline (ALP) and acid (AP) phosphatases and the content of microelements — calcium and phosphorus. In the blood of rats it was studied the concentration of general protein, lipid peroxidation products — malonic dialdehyde (MDA) and the enzyme activity of antioxidant system — catalase (CAT) and superoxide dismutase (SOD).Results and conclusions. Results of conducted experimental research of the effect of endodontic filling materials on the activity of the regeneration processes of bone tissue show that proposed compositions based on hydroxyapatite and beta-tricalcium phosphate, due to their osteoconductive and biorevitalization qualities, promote more active stimulation of bone tissue regeneration processes compared to generally accepted drugs.

Spermine Pre-Treatment Improves Some Physiochemical Parameters and Sodium Transporter Gene Expression of Pumpkin Seedlings under Salt Stress

It is known that polyamines (PAs) including spermine (Spm) enhance the abiotic stress tolerance of crops. Here, the effects of hydroponic Spm pre-treatment on the amelioration of the adverse effects of salinity were investigated in pumpkin (Cucurbita pepo L.) that is an economically important horticultural crop and sensitive to salinity, especially at the establishment stage. For this purpose, 10-day-old, uniform-sized seedlings were transplanted to plastic containers containing Hoagland nutrient solution. Spm was added at 0.1 and 1 mM to the hydroponic medium for 5 days before stress. The plants were treated with 40 and 80 mM NaCl for inducing salinity stress. Salt stress reduced the plant growth and potassium content in roots, and these detrimental effects were alleviated when plants were pre-treated with Spm. Salinity stress caused a significant increase in sodium and γ-amino butyric acid (GABA) content when compared with controls. Spm pre-treatment ameliorated these salinity stress effects by increasing sodium content of root and leaves GABA content. Expression analysis of two sodium transporter genes, salt overly sensitive1 (SOS1) and Na+/H+ exchanger (NHX1) revealed that their expression was differentially induced in roots of plants treated either with salinity or Spm. These results suggest that Spm via the overexpression of the NHX1 gene substantially increased the tolerance to stress by sequestering excess Na+ into the vacuoles and sustaining a better cellular environment. Moreover, Spm has potential to scavenge directly free radical and to alleviate growth inhibition and promote the activity of antioxidant system enzymes in pumpkin seedlings under salt stress.

Вплив препаратів «Бровермектин-грануляттм» і «Авесстимтм» на рівень продуктів ПОЛ та активність ферментів АОС у гепатопанкреасі однорічок білого амура, уражених моногенеями

The data on the influence of the anti-parasitic drug «Granulated brovermectin» and immunomodulator «Avesstim» on the level of lipid oxidation products (LOPs) and the activity of antioxidant system enzymes (AOS) in hepatopancreas of white currant annuals affected by various ectoparasites are given. The research was carried out at the garden and fish farms of the state enterprise «Rybgosp Galitsky» (now Rybgosp «Burshtynskyy» LLC) of the Rogatyn district of the Ivano-Frankivsk region and the farm enterprise «Dobrotvirskiy rybzavod» in the Kamianko-Buzsky district of the Lviv region, located on the warm waters of the Burshtynskaya cooling water reservoirs and Dobrotvirskaya TPS. For the study, white amur of the same age (with body weight 45–47 g) was selected, infected with Dactylogyrus lamellatus, Gyrodactylus ctenopharyngodonis and both parasites at the same time.It was found that white amur of the same age infected with Dactylogyrus lamellatus, Gyrodactylus ctenopharyngodonis and in mixed infestations, the level of TBK-products in hepatopancreas decreased by 25.7% after the treatment with «Granulated brovermectin»; 29.3 and 32.4%, diene conjugates – by 13.5; 21.7 and 18.9% at P < 0.001 in all cases. At the same time using the drugs «Granulated brovermectin» and «Avesstim», the reduction of the above-mentioned indicators in all cases was also reliable (P < 0.001) and was 68.0; 66.3 and 64.0 and 32.0; 35.4 and 36.2%. Concerning the content of lipid hydroperoxides in hepatopancreas of treated fish, its decrease was probable (P < 0,05) only for the combined application of the studied drugs.After use of the above-mentioned preparations the activity of enzymes of antioxidant protection in hepatopancreas of white amur of the same age increased. However, it should be noted that fish affected by dactylosurids, only the activity of superoxide dismutase (SOD) in the complex use of «Granulated brovermectin» and «Avesstim» increased significantly (P < 0.001). In the case of damage by hydroactylics, the activity of superoxide dismutase in hepatopancreas of fish that was administered only «Granulated brovermectin» probably (P < 0,05) increased by 9,4%, and the use of a complex of drugs – by 28,4% (P < 0,001). After mixed infections, as well as for monoinvasia, in the hepatopancreas of white amur of the same age after the use of drugs, an increase in the activity of all the enzymes studied, however, was only significant increase in the activity of SOD (P < 0,05; 0,001). Thus, the complex application of drugs for monogenous doses of fish had a more significant impact on the biological equilibrium in the system LOPs↔AOS.

Вплив біомаси Phaffia rhodozyma й антиоксидантів на ензими системи глутатіону у тканинах білих щурів за дії афлатоксину В1

Вплив біомаси Phaffia rhodozyma й антиоксидантів на ензими системи глутатіону у тканинах білих щурів за дії афлатоксину В1

Accelerated ageing and subsequent imbibition affect seed viability and the efficiency of antioxidant system in macaw palm seeds

Accelerated ageing is an accurate test indicator of seed vigor and storability that helps to understand the mechanisms of cellular and biochemical deterioration that occur during seed ageing. This study was carried out to elucidate the mechanisms of ageing in macaw palm embryos. Seeds were artificially aged during 4, 8 and 12 days at 45 °C and 100% relative humidity. After ageing, seeds were tested for viability (tetrazolium), electrical conductivity, lipid peroxidation (MDA) and hydrogen peroxide (H2O2) content. Part of the aged seeds was imbibed for 8 days and then determined the hydrogen peroxide content and the activity of antioxidant system enzymes (superoxide dismutase, catalase and glutathione reductase). Ageing reduced the embryo viability from 8 days of treatment and increased malondialdehyde content (MDA) and solute leakage. Hence, membrane permeability correlated with both loss of viability and lipid peroxidation. Imbibition after ageing significantly increased H2O2 content along with superoxide dismutase activity. Catalase activity was significantly higher than control in embryos aged from 8 days and imbibed, and glutathione reductase activity did not change. Our results suggest that macaw palm seed deterioration during accelerated ageing is closely related to lipid peroxidation, and that enzymatic antioxidant system is not completely efficient in reducing reactive oxygen species after imbibition, a critical phase to germination. Moreover, accelerated ageing test can be used as a reliable model to understand the mechanisms involved in palm seeds deterioration.

Biochemical Markers of Metabolic Syndrome in Pregnant Women

The aim of the study was to elucidate the state of lipid metabolism, the processes of lipid peroxidation (LPO) and the state of the antioxidant system (AOS) in pregnant women with metabolic syndrome. A comprehensive examination of pregnant women without pathology was performed, with signs of a metabolic syndrome. Analysis of the data showed that in pregnant women with impaired glucose metabolism, activation of LPO processes takes place against the background of a decrease in the activity of AOS enzymes. Active metabolites of oxygen (AMC) and LPO products lead to a decrease in the NO content of the main vasodilating factor. As a result of these disorders, hypoxia develops, which significantly affects the formation of the fetus. The data obtained make it possible to recommend the determination of the parameters of the POL-AOS system and the NO-forming endothelial function as additional laboratory tests in pregnant women with metabolic syndrome (MS).

ASSESSMENT OF BIOCHEMICAL PARAMETERS IN PREGNANT WOMEN WITH METABOLIC DISORDERS: A COMPARATIVE STUDY

Objective : еvaluation of lipid metabolism, lipid peroxidation (LPO) and antioxidant system (AOS) in pregnant women with various metabolic disorders. Materials and methods . This study was conducted in pregnant women with no known metabolic disorder, in those with the symptoms of metabolic syndrome and in women with gestational diabetes mellitus. Results . We found evidence for activation of LPO in pregnant women with impaired glucose metabolism; the LPO developed on the background of decreased activity of AOS enzymes. As proposed, the active oxygen species and the LPO products caused a reduction in the level of nitric oxide (NO) - a major vasodilating substance. The resulting vasoconstriction might lead to hypoxia with its negative impact on fetus development. Conclusion . Based on the obtained data we recommend using the parameters of LPO-AOS and the markers of endothelial NO-production as additional laboratory tests in pregnant women with gestational diabetes mellitus and metabolic syndrome.

Genistein: A Novel Anthocyanin Synthesis Promoter that Directly Regulates Biosynthetic Genes in Red Cabbage in a Light-Dependent Way.

Genistein (GNT), an isoflavone, is used in the clinical treatment of various health disorders. GNT is found in primary food source plants and some medical plants. However, studies on the functions of GNT in plants are rarely reported. In this study, we demonstrated that GNT plays an important role in promoting anthocyanin accumulation in red cabbage. GNT solutions (10, 20, 30, 40, and 50 mg/L) as foliar fertilizers were applied to red cabbage. Consequently, anthocyanin accumulation in red cabbage increased in a light-dependent manner. GNT solution at 30 mg/L exhibited the optimal effect on anthocyanin accumulation, which was twice that of the control. Quantitative real-time PCR analysis indicated that GNT application upregulated the expression of all structural genes, contributing to anthocyanin biosynthesis under light conditions. Under dark conditions, GNT exerted no significant promotive effect on anthocyanin accumulation; only early biosynthetic genes of anthocyanin biosynthesis responded to GNT. The promotive effect of GNT on anthocyanin biosynthesis is directly attributable to the regulation of structural gene expression. Transcription factors exhibited no response to GNT. The levels of anthocyanin in red cabbage positively correlated with the enzyme activities of antioxidant systems. This finding correlation suggested that the promotive effect of GNT on anthocyanin levels was correlated with improved antioxidant activity in the red cabbage.

Clinical experience of evaluation of intoxication level and endogenous antioxidant system dynamics in patients with acute peritonitis

<p>The results of 123 patients with acute peritonitis were analyzed. All patients were operated in toxic and terminal<br />phases. The indicators of intoxication and enzyme activity of antioxidant system were estimated within 6 hours, 1 and<br />3 days after surgery treatment. As result of this investigation was confirmation that one of the factors homeostasis<br />violations in peritonitis is activation of peroxide lipid – diene conjugates, TBA-active products in the blood and reduce<br />the activity of antioxidant system – glutathione peroxidase, catalase, glucose-6-phosphate dehydrogenase and<br />glutathione reductase as main branch of antiradikal and antiperoxidative protection.</p>

Ni accumulation and its effects on physiological and biochemical parameters of Eichhornia crassipes

Ni accumulation and concomitant physiological and biochemical responses were studied in Eichhornia crassipes11Capsule: E. crassipes has the ability to adjust their physiology and biochemical responses under Ni stress. exposed to different concentrations (1, 2, 3 and 4mgl−1 Ni) for 72h. E. crassipes1 rapidly sorbed Ni during the first 24h. Ni concentration in roots was significantly higher than in aerial parts. Continuity of the photosynthetic activity was observed by a significant increase of pigment concentrations during the first 48h, followed by a decrease at 72h. In aerial parts, MDA concentration increased significantly during first 48h at the highest Ni concentration exposure. However, was evidently counteracted by the compensatory protective mechanism of increased antioxidant enzyme activities. In roots, a significant increase in enzyme activities of antioxidant system did not prevent lipid peroxidation observed by an increase in MDA concentration at 72h of exposure. Our results suggest that E. crassipes1 was able to tolerate Ni stress increasing the activity of its antioxidant system at short exposure times and low Ni concentrations studied.

Lead tolerance of water hyacinth (Eichhornia crassipes Mart. - Pontederiaceae) as defined by anatomical and physiological traits

This study aimed at verifying the lead tolerance of water hyacinth and at looking at consequent anatomical and physiological modifications. Water hyacinth plants were grown on nutrient solutions with five different lead concentrations: 0.00, 0.50, 1.00, 2.00 and 4.00 mg L-1 by 20 days. Photosynthesis, transpiration, stomatal conductance and the Ci/Ca rate were measured at the end of 15 days of experiment. At the end of the experiment, the anatomical modifications in the roots and leaves, and the activity of antioxidant system enzymes, were evaluated. Photosynthetic and Ci/Ca rates were both increased under all lead treatments. Leaf anatomy did not exhibit any evidence of toxicity effects, but showed modifications of the stomata and in the thickness of the palisade and spongy parenchyma in the presence of lead. Likewise, root anatomy did not exhibit any toxicity effects, but the xylem and phloem exhibited favorable modifications as well as increased apoplastic barriers. All antioxidant system enzymes exhibited increased activity in the leaves, and some modifications in roots, in the presence of lead. It is likely, therefore, that water hyacinth tolerance to lead is related to anatomical and physiological modifications such as increased photosynthesis and enhanced anatomical capacity for CO2 assimilation and water conductance.

Effects of pH stress on antioxidant system enzyme activities and gene expression of Fenneropenaeus chinensis

Chinese shrimp,Fenneropenaeus chinensis,is an important mariculture species in China.Recently de-teriorated pond environment due to intensive culture caused increased incidence of stress-induced diseases.It is well known that environmental stress can induce oxidative stress.However,there is little information about the effects of pH changes on antioxidant system of Chinese shrimp.In this study,Chinese shrimps were exposed to water of pH7.0 and 9.0 for 148 h and pH8.2 was set as control.Total antioxidation activity(T-AOC),anti-superoxide anion activity,catalase(CAT) activity and the expression CAT,peroxiredoxin(Prx) gene were analyzed in gill,hepatopancreas,muscle and haemocytes of Chinese shrimp after 0 h,3 h,12 h,24 h,48 h,72 h,96 h,120 h and 148 h exposure.The T-AOC,anti-superoxide anion activity,CAT activity and the gene expression of CAT in different tissues increased within 12-14 h of pH stress.However,they were inhibited in the extending periods of pH stress time.The Prx gene expression in heaptopancreas and muscle gradually increased,but de-creased in gill and haemocytes with pH stress time prolonging.The enzyme activities and gene expression of an-tioxidant system in gills first reached its highest level in pH 9.0 group,faster than other tissues in 9.0 group.And the antioxidant enzyme activities in hepatopancreas in pH 7.0 group changed faster than in other tissues.The re-sults indicate that the antioxidant enzyme activities and gene expression of Chinese shrimp were induced by short-term pH stress which is the response to oxidative stress,while they were inhibited with pH stress time pro-longing.It was shown that long time neutral and alkaline-induced oxidative stress probably caused the antioxidant defense system injury in Chinese shrimp.Gills and hepatopancreas could be the sensitive tissues to high and low pH stress,respectively.

Lipid Peroxidation and Antioxidant System Activity Changes of Rat Blood and Cardiac Muscle Cells Under Chronic Stress

We studied the functionality of the antioxidant system in laboratory rat cardiac muscle cells and blood under psycho-emotional stress. It was found that 40-day isolation and violation of diurnal cycle among the animals were accompanied by the intensification of lipid per oxidation process shown by a rise in the quantity of one of the primary and final products of this process - diene conjugates and thiobarbituric acid active compounds, including malonedialdehydes and marked with a reduced activity of antioxidant system enzymes, such as catalase and superoxide dismutase activity. Based on the results, we pro-posed that psychological stress is one of the factors contributing to the development of various cardiac diseases.

Mechanisms of the internal structure and operation of Panicum aquaticum in response to arsenic

Due to the high toxicity of arsenic, many studies have attempted to improve the techniques for its removal from the environment, using methods such as phytoremediation by tolerant species. To evaluate the tolerance of Panicum aquaticum to contamination by arsenic, both physiological and anatomical evaluations were conducted. The plants were grown in Hoagland and Arnon nutrient solution in a greenhouse for 30 days under six concentrations of arsenic: 0.00, 0.25, 0.50, 1.00, 2.00, and 4.00 mM. Analyses of growth, gas exchange, the anatomy of leaves and roots and of the activity of antioxidant system enzymes were conducted. The relative growth rate, specific leaf area and leaf area ratio were modified in the presence of arsenic. Gas exchange was not affected. The leaf anatomy showed reductions in the epidermal thicknesses on the abaxial face, on the blade and on the chlorenchyma; increases in the set of bulliform cells, in the cuticle thickness and in the area of the sclerenchyma; reductions in the number and distance of vascular bundles; an increase in the stomatal index; an increase in the stomatal functionality only on the adaxial face of the epidermis; and reductions in the number and density of stomata. The roots presented reductions in the thicknesses of the epidermis, endodermis and exodermis and modifications in the Carlquist vulnerability index. Only the catalase activity was affected, showing an increase at the lowest concentrations followed by a decrease at higher concentrations. P. aquaticum proved partially tolerant to arsenic at the lowest concentrations and presented evidence of toxicity at the highest concentrations.

Responses of the flavonoid pathway to UV-B radiation stress and the correlation with the lipid antioxidant characteristics in the desert plant Caryopteris mongolica

Caryopteris mongolica is a dwarf shrub mainly found in grassland and desert areas of north-west China, and which can survive severe environmental stress. This study aimed to assess the responses of the flavonoid pathway to UV-B radiation treatments and its correlation to the lipid peroxide and antioxidant systems in C. mongolica. In UV-B radiation experiments, plants were exposed to UV-B radiation treatments with a intensity of 30J/s for 1, 4 and 24h, respectively. A control group without UV-B radiation treatment was also used. The chlorophyll fluorescence parameters, contents of chlorophyll and carotenoid, levels of lipid peroxidation, activities of antioxidant system enzymes, accumulations of total flavonoids and anthocyanins, and activities of phenylalanine ammonialyase (PAL) and chalcone isomerase (CHI) under different UV-B radiation treatments were investigated. The correlations between products and key enzymes in the flavonoid pathway and the lipid peroxide and antioxidant systems were also analyzed. The results showed that chlorophyll fluorescence parameters decreased within 24h of treatment. The chlorophyll contents decreased within 4h and remained stable after 24h. Carotenoid content significantly increased. The level of MDA, the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and peroxidase (POD) and the contents of total flavonoids and anthocyanidins increased, while catalase (CAT) activity decreased under UV-B stress. The activities of PAL and CHI also increased with the increased content of total flavonoids. The flavonoid products anthocyanidins had a significant positive correlation with MDA level, as well as the activities of antioxidant enzyme SOD. In conclusion, UV-B radiation induced the degradation of photosynthetic pigments and decreased photochemical efficiency of Photosystem II; increased the contents of MDA, total flavonoids and anthocyanidins; and also enhanced activities of antioxidant enzymes (SOD, APX and POD) and key enzymes (PAL and CHI) in the flavonoid pathway in C. mongolica. Thus, we speculate that the flavonoid pathway were involved in the regulation of stress resistance in C. mongolica.

Functional state of rat cardiomyocytes and blood antioxidant system under psycho-emotional stress

We studied the functionality of the antioxidant system in laboratory rat cardiomyocytes and blood under psycho-emotional stress. It was found that 40-day isolation and violation of diurnal cycle among the animals were accompanied by the intensification of lipid peroxidation process and marked with a reduced activity of antioxidant system enzymes, such as catalase and superoxide dismutase activity. The results suggested that psycho-emotional stress was accompanied by oxidative stress, causing a reduction in the intensity of energy metabolism in cardiomyocytes, which was further strengthened by the fact that the activity of the enzymes involved in ATP synthesis in mitochondria was reduced. Based on the results, we proposed that psychological stress is one of the factors contributing to the development of various cardiac diseases.