Low Molecular Antioxidants Research Articles

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.

How to Improve the Antioxidant Defense in Asphyxiated Newborns-Lessons from Animal Models.

Oxygen free radicals have been implicated in brain damage after neonatal asphyxia. In the early phase of asphyxia/reoxygenation, changes in antioxidant enzyme activity play a pivotal role in switching on and off the cascade of events that can kill the neurons. Hypoxia/ischemia (H/I) forces the brain to activate endogenous mechanisms (e.g., antioxidant enzymes) to compensate for the lost or broken neural circuits. It is important to evaluate therapies to enhance the self-protective capacity of the brain. In animal models, decreased body temperature during neonatal asphyxia has been shown to increase cerebral antioxidant capacity. However, in preterm or severely asphyxiated newborns this therapy, rather than beneficial seems to be harmful. Thus, seeking new therapeutic approaches to prevent anoxia-induced complications is crucial. Pharmacotherapy with deferoxamine (DFO) is commonly recognized as a beneficial regimen for H/I insult. DFO, via iron chelation, reduces oxidative stress. It also assures an optimal antioxidant protection minimizing depletion of the antioxidant enzymes as well as low molecular antioxidants. In the present review, some aspects of recently acquired insight into the therapeutic effects of hypothermia and DFO in promoting neuronal survival after H/I are discussed.

Subcellular compartmentalization of the plant antioxidant system: an integrated overview.

The antioxidant system (AOS) maintains the optimal concentration of reactive oxygen species (ROS) in a cell and protects it against oxidative stress. In plants, the AOS consists of seven main classes of antioxidant enzymes, low-molecular antioxidants (e.g., ascorbate, glutathione, and their oxidized forms) and thioredoxin/glutaredoxin systems which can serve as reducing agents for antioxidant enzymes. The number of genes encoding AOS enzymes varies between classes, and same class enzymes encoded by different gene copies may have different subcellular localizations, functional loads and modes of evolution. These facts hereafter reinforce the complex nature of AOS regulation and functioning. Further studies can describe new trends in the behavior and functioning of systems components, and provide new fundamental knowledge about systems regulation. The system is revealed to have a lot of interactions and interplay pathways between its components at the subcellular level (antioxidants, enzymes, ROS level, and hormonal and transcriptional regulation). These facts should be taken into account in further studies during the AOS modeling by describing the main pathways of generating and utilizing ROS, as well as the associated signaling processes and regulation of the system on cellular and organelle levels, which is a complicated and ambitious task. Another objective for studying the phenomenon of the AOS is related to the influence of cell dynamics and circadian rhythms on it. Therefore, the AOS requires an integrated and multi-level approach to study. We focused this review on the existing scientific background and experimental data used for the systems biology research of the plant AOS.

Studies on the development of vegetable-based powdered beverages – Effect of the composition and dispersing temperature on potential bioaccessibility of main low-molecular antioxidants and antioxidant properties

This study evaluates the nutritional value, pro-health components, and antioxidant capacity of new functional powdered beverages based on lyophilized lentil sprouts, carrot, and pumpkin. The effect of functional additives and temperature of rehydration was also evaluated. The highest amounts of phenolics, regardless of the rehydration temperature, were determined for the beverages enriched with broccoli sprouts - 14.4 mg GAE/100 mL and 13.1 mg GAE/100 mL for 20 °C and 80 °C, respectively. Most importantly, the phenolics were well bioaccessible in vitro. The antiradical abilities were significantly improved by replacement of lentil sprout powder with functional additives. Compared to the initial drink prepared at 20 °C, the highest increase by c. a. 58, 33, and 34% was observed after enrichment with beetroot, beetroot and broccoli sprouts, as well as beetroot, broccoli sprouts, and parsley leaves, respectively. The highest reducing potential was determined for the beverages enriched with powdered beetroots - 17 mg TE/100 mL. A clear negative effect of high temperature of rehydration on antiradical properties was observed; however, an opposite trend was found for reducing abilities. The quality of functional beverages can be tailored by both addition of functional ingredients and the temperature of rehydration.

Ecological and Geochemical Conditions for the Accumulation of Antioxidants in the Leaves of Lathyrus maritimus (L.) Bigel.

The article explores how location affected the dynamics of accumulation of ascorbic acid (AC) and oxidized forms of AC—dehydroascorbic acid (DAA) and diketogulonic acid (DKGA) in beach pea during ontogenetic development. Our analysis focuses on research of the ecological and geochemical conditions growing of the plant on the Curonian Spit. The level of hydrogen peroxide and the activity of enzymes that break it down were analyzed. Antioxidant activity and the total concentration of phenolics were evaluated in the leaves of beach pea on the leeward and windward sides of the foredune. It was established that the level of AC, DAA, and DKGA was higher in the plants growing on the windward side of the foredune. A higher concentration of peroxy compounds, which stimulate the biosynthesis of antioxidant enzymes (catalase, ascorbate peroxidase), polyphenols, and other low molecular antioxidants (AOA) was observed in the leaves of these plants. The plants on the windward side enter phenological stages one or two weeks later than their counterparts on the leeward side of the foredune do. There was a generally negative correlation between the temperature of the soil and the accumulation of ascorbate system acids in the leaves of the studied plants (r = −0.46/(−0.68), p < 0.05). The accumulation of low molecular antioxidants and enzymes in beach pea suggests their adaptation to the adverse conditions of the windward side of the foredune.

Reactive oxygen species (ROS) as pleiotropic physiological signalling agents.

'Reactive oxygen species' (ROS) is an umbrella term for an array of derivatives of molecular oxygen that occur as a normal attribute of aerobic life. Elevated formation of the different ROS leads to molecular damage, denoted as 'oxidative distress'. Here we focus on ROS at physiological levels and their central role in redox signalling via different post-translational modifications, denoted as 'oxidative eustress'. Two species, hydrogen peroxide (H2O2) and the superoxide anion radical (O2·-), are key redox signalling agents generated under the control of growth factors and cytokines by more than 40 enzymes, prominently including NADPH oxidases and the mitochondrial electron transport chain. At the low physiological levels in the nanomolar range, H2O2 is the major agent signalling through specific protein targets, which engage in metabolic regulation and stress responses to support cellular adaptation to a changing environment and stress. In addition, several other reactive species are involved in redox signalling, for instance nitric oxide, hydrogen sulfide and oxidized lipids. Recent methodological advances permit the assessment of molecular interactions of specific ROS molecules with specific targets in redox signalling pathways. Accordingly, major advances have occurred in understanding the role of these oxidants in physiology and disease, including the nervous, cardiovascular and immune systems, skeletal muscle and metabolic regulation as well as ageing and cancer. In the past, unspecific elimination of ROS by use of low molecular mass antioxidant compounds was not successful in counteracting disease initiation and progression in clinical trials. However, controlling specific ROS-mediated signalling pathways by selective targeting offers a perspective for a future of more refined redox medicine. This includes enzymatic defence systems such as those controlled by the stress-response transcription factors NRF2 and nuclear factor-κB, the role of trace elements such as selenium, the use of redox drugs and the modulation of environmental factors collectively known as the exposome (for example, nutrition, lifestyle and irradiation).

ВОЗРАСТНЫЕ И ПОЛОВЫЕ ОСОБЕННОСТИ АНТИОКСИДАНТНОЙ СИСТЕМЫ КРОВИ КРОЛИКОВ

Despite the multifactorial oxidant-antioxidant interactions in the body, it is necessary to determine the antioxidant status as the total balance of free radical generation processes and the activity of the enzymatic and nonenzymatic defense lines of the body. In this regard, an important diagnostic problem is the selection of adequate indicators that reflect both components. Obviously, these indicators should be stable and multiple. However, there is another problem associated with the selection of integrated indicators that simplify the information assessment of the antioxidant status of the body. The aim of this research work was to study the intensity of lipid peroxidation and changes in the antioxidant system in intact rabbits of different age groups and sex in postnatal ontogenesis. The studies were carried out on 30 (15 males and 15 females) rabbits in bioclinics. Blood was taken from animals aged 60, 120 and 180 days. The content of diene conjugates and Malon dialdehyde, as well as low-molecular antioxidants – tocopherol and retinol – were determined in blood plasma. The activity of antioxidant enzymes – glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase was evaluated in hemolysates. Thus, the activity of SOD, CAT, GP, GR and the concentration of DC and MDA in some cases significantly decreased in all studied groups of animals by the end of the experiment. The content of cholesterol, triglycerides and glucose shows the sexual differences between male and female rabbits in the lipid and energy spectrum of blood plasma. At the age of 180 days, the increase in cholesterol, triglycerides and glucose in males amounted to 13.1%, 37.4% (at P ≤ 0.001) and 14.1%. Accordingly, for females: 17.2%, 37.8% (at P ≤ 0.001) and 15.8%. At the age of 120 and 180 days there was an unreliable decrease in all indicators in animals as compared with the values obtained in the 60-day age. The content of tocopherol in males in 120 and 180 days increased by 17.9 (at P ≤ 0.001) and 21.2% (at P ≤ 0.001), retinol – by 45.5% (at P ≤ 0.01) and 63.6% (at P ≤ 0.01) as contrasted to to the initial (60 days) values. Similarly, females showed a significant increase in the concentration of tocopherol by 20.7% (at P ≤ 0.001) and 23.3% (at P ≤ 0.001), retinol – by 30.8% (at P ≤ 0.05) in 180 days. Thus, the influence of age and sex on the indicators of peroxide and lipid metabolism, the content of fat-soluble vitamins A and E in blood plasma, the activity of the main enzymes of antioxidant protection of animals has been shown. According to the content of cholesterol and triglycerides, sexual differences between male and female rabbits in the lipid spectrum of blood plasma have been established. This, in turn, helped determine the specific weight of individual factors of the AOS-POL system in the ontogenesis of rabbits.

Antioxidant status in patients with paranoid schizophrenia and Alzheimer disease

To study the antioxidant profile of blood plasma in patients with paranoid schizophrenia and Alzheimer disease (AD). Thirty-three patients with paranoid schizophrenia and 18 patients with AD were included in the study. Patients with schizophrenia were stratified into two subgroups by response to therapy. The indicators of the antioxidant profile were determined using methods based on chemiluminometry and spectrofluorimetry. Systemic oxidative stress due to insufficiency of low molecular weight plasma antioxidants is not determined neither in AD nor in treatment resistant schizophrenia. At the same time, a «thiol» oxidative stress, which indirectly indicates a deficiency of the glutathione system, is present in both groups. In patients with paranoid schizophrenia responsive to treatment, systemic oxidative stress is more pronounced and «thiol» oxidative stress is less significant. Among the antipsychotics studied, haloperidol, zuclopenthixol, risperidone and ziprasidone do not exhibit antioxidant properties, but periciazine, clozapine and especially chlorpromazine exhibit strong antioxidant properties, but they unlikely affect the antioxidant potential of blood plasma. The glutathione part of the antioxidant system is mostly affected, but systemic oxidative stress is not significant in patients with treatment resistant paranoid schizophrenia and AD. Oxidative disorders are more pronounced in treatment responsive paranoid schizophrenia.

The Use of Oxidative Stress Parameters of Bivalve Mollusks Dreissena polymorpha (Pallas, 1771) as Biomarkers for Ecotoxicological Assessment of Environment

The aim of this study was to investigate biomarkers of oxidative stress: сatalase (CAT), glutathione (GR), glutathione S-transferase (GST), low-molecular antioxidant—reduced glutathione (GSH) and lipid peroxide oxidation marker—malondialdehyde (MDA) and to measure heavy metal (НМ) concentrations in Dreissena polymorpha soft tissues at three different sampling sites in the Rybinsk reservoir (one of the largest in Europe) in order to assess exposure to anthropogenic pollution. The reservoir has a considerable source of pollution in its northern part due to a large industrial complex in Cherepovets. Mussels were collected at three sites which differ in the levels of anthropogenic load: more contaminated sites 1 (Cherepovets) and 2 (Koprino). Site 3 (Vesyegonsk) is relatively clean and is used as a control. In soft tissues of mussels from sites 1 and 2 significantly higher concentrations of HM (Pb, V, Cr, Ni, Cu, Mn, Zn, Cd) were detected than in mussels from site 3. Mussels from sites 1 and 2 subjected to long-term contamination from Cherepovets industry showed considerable CAT, MDA and GSH induction compared to mussels from relatively clean site 3. The correlation was found between elevated HM content and increased levels of CAT, MDA and GSH. The obtained data suggest that HM may contribute to the oxidative stress induction in mussel. MDA, CAT and GSH sensitivity in D. polymorpha demonstrated a possible use of these biomarkers in freshwater.

A Switch between Antioxidant and Prooxidant Properties of the Phenolic Compounds Myricetin, Morin, 3',4'-Dihydroxyflavone, Taxifolin and 4-Hydroxy-Coumarin in the Presence of Copper(II) Ions: A Spectroscopic, Absorption Titration and DNA Damage Study.

The beneficial effects of polyphenols, predominantly in the context of oxidative stress-related diseases such as cancer, cardiovascular diseases and neurological conditions including Alzheimer’s and Parkinson’s diseases, have been documented by a number of papers and reviews. The antioxidant/prooxidant properties of phenolic compounds are related mainly to the number and positions of hydroxyl groups and to their redox metal (Cu, Fe) chelating capacity. In this work we studied structurally distinct phenolic molecules such as myricetin, morin, 3′,4′-dihydroxy-flavone, taxifolin and 4-hydroxycoumarin, either alone or as interacting with Cu2+ ions. EPR and UV-Vis spectroscopy confirmed that the effective binding of cupric ions to phenolic compounds requires the presence of the 3-OH and 4-CO groups on the flavonoid C ring and unsaturated C2-C3 bond of the C-ring, which permits through-conjugation with the B-ring. An ABTS assay revealed that radical scavenging activities of phenolic compounds are related to their number of hydroxyl groups, planarity of the molecular skeleton, extent of delocalization and they decrease in the order: myricetin > morin > 3′,4′-dihydroxyflavone ~ 4-hydroxy coumarin > taxifolin. Absorption titrations indicate that copper ions can modulate the DNA binding affinity of flavonoids via the formation of their Cu-chelates. Gel electrophoresis measurements indicated that the protective effect of the phenolic compounds decreases in the order: 3′,4′-dihydroxyflavone > 4-OH coumarin > morin > taxifolin ~ myricetin. This can be explained by the fact that myricetin, taxifolin and morin form stable Cu(II) complexes capable of causing DNA damage via interaction with DNA and ROS formation via the Fenton reaction. Application of ROS scavengers revealed the formation of singlet oxygen, superoxide and hydroxyl radicals and their concerted synergistic effect on the DNA. The overall results suggest that the most pronounced DNA damage has been observed for flavonoids containing higher number of hydroxyl groups (including 3-OH group of the C ring), such as myricetin (six hydroxyl groups), morin and taxifolin (five hydroxyl groups) in the presence of Cu(II) ions. The proposed mechanism of action by which Cu(II) complexes of myricetin, morin and taxifolin interact with DNA predispose these substances to act as potential anticancer agents. The anticancer activity of phenolic compounds can be explained by their moderate prooxidant properties, which can boost ROS formation and kill cancer cells. Alternatively, slight prooxidant properties may activate antioxidant systems, including antioxidant enzymes and low molecular antioxidants such as glutathione and thus act as preventive anticancer agents.

Changes in the content of low-molecular antioxidants and carbohydrates in pinus silvestris, rosa acicularis, ledum palustre in the context of the transition to winter dormancy in Yakutia

The accumulation of low-molecular antioxidants and carbohydrates in three wintering plants of Yakutia in the summer-autumn period (July, August, September) was studied. Determining the content of the sum of low-molecular antioxidants (LMAO), the sum of flavonoids, ascorbic acid, and the sum of carbohydrates was conducted spectrofotometrically in the needles of pinus silvestris L. and annual shoots of ledum palustre L., rosa acicularis Lindl. The research shows that in general a decrease of temperature (a transition from summer months to autumn months) increases the content of LMAO in the three examined plants. The study also shows that an increase of the LMAO amount in the content descends to a greater extent due to the accumulation of ascorbic acid. In the dynamics of accumulation of flavonoids during the studied period, the maximum was noticed in August and followed by a decline in September. In the dynamics of the content of carbohydrates (reducing sugars), as well as the LMAO, was revealed a gradual increase in the period from July to September. The wide fluctuations in the content of the sum of LMAO, ascorbic acid, and flavonoids with decreasing temperature were found in the rosa acicularis Lindl, as well as in the sugars in the needles of pinus silvestris L. Thus, the revealed dynamics of accumulation of LMAO in wintering plants (fraction of flavonoids, ascorbic acid) in the period of preparation for the transition to winter dormancy did not show the presence of an explicit dependence on the accumulation of the main cryoprotectants of plants, i.e. carbohydrates.

Constant darkness conditions modulate the effects of melatonin and luzindole on the antioxidant enzyme activities and levels of retinol and α-tocopherol in rats

This study was conducted to evaluate the effects of both exogenous melatonin and melatonin receptor antagonist luzindole on the activities of antioxidant enzymes (AOE) (superoxide dismutase, SOD; catalase, CAT) and the level of low-molecular antioxidant vitamins (retinol, α-tocopherol) in male Wistar rats kept in normal light conditions (LD 12:12) or constant darkness (DD). In LD, while melatonin had no influence on the studied antioxidants, luzindole caused an increase in retinol and a decrease in α-tocopherol contents in the liver compared to the control. In DD, with no influence on AOE activities, both drugs exerted similar effects on the liver retinol and kidney α-tocopherol contents, increasing them in comparison with control. Exposing the animals to DD induced an increase in kidney SOD activity and in liver retinol content. Moreover, DD-mel rats had higher SOD activity in the liver and kidney and a higher retinol level in the liver compared to LD-mel ones; DD-luz rats had a higher liver retinol content compared to LD-luz ones. Liver retinol level seems to be the most sensitive to influence of DD, melatonin and luzindole; the data are probably connected with the involvement of vitamin A in the regulation of circadian rhythms.

MICROPROPAGATION STUDIES AND ANTIOXIDANT ANALYSIS OF THE ENDANGERED PLANTS OF BULGARIAN YELLOW GENTIAN (Gentiana lutea L.)

In order to develop an efficient micropropagation system, it is essential to establish the appropriate concentration of growth regulators for seed germination, shoot formation and rooting. Nodal segments from in vitro obtained seedlings of Gentiana lutea L. were cultured in vitro in Murashige and Skoog’s medium supplemented with BAP, Thidiazuron and Zeatin (0.5, 1.0 and 2.0 mg L−1). A maximum number of shoots with the highest height was recorded at 2.0 mg L−1 BAP. For further optimization of the process, we used nutrient media containing BAP and Zeatin with a combination of low concentration of Indoleacetic acid. MS medium containing 2.0 mg L−1 Zeatin and 0.2 mg L−1 IAA resulted in maximum numbers of shoots 94.3) with shoot height 2.5 cm. The multiple plants were successfully ex vitro acclimatized with 65% survival. The presence of growth regulators (2.0 mg L−1 Zeatin and 0.2 mg L−1 IAA) in the nutrient media resulted in an effective antioxidant activity in G. Lutea determined by the low molecular antioxidant metabolites such as phenols and flavonoids and activities of antioxidant enzymes – catalase, ascorbate peroxidase, guaiacol peroxidase, and superoxide dismutase. The described protocol allows the establishment of numerous micropropaged plants of rare and endangered G. lutea.

Modification of soybean and lupine sprouting conditions: influence on yield, ROS generation, and antioxidative systems

Formation of free radicals’ and antioxidants’ biosynthesis during seeds sprouting strongly depends on plant growth conditions, especially while sprouts are fortified in iron. The influence of watering with FeSO4 solution on soybean and lupine sprouting, yield of iron accumulated in plant tissue, as well as free radical (reactive oxygen and nitrogen species) synthesis and antioxidant activity (capacity) were the objective of this study. Optimal iron accumulation and biomass efficiency were obtained for 3 day watering with water, followed by abiotic stress application (Fe2+ ions). For lupine sprouts, maximal radical formation (up to ~ 5.7 a.u.) took place on the fifth day of culturing in these conditions, while, for soybean sprouts, continuous increase in their activity was observed until the seventh day (up to ~ 5.8 a.u.). Total antioxidant activity in lupine sprouts increased definitely, even more than three times during 7 days of lupine growing, but, for soybean, it was almost steady. The same trend was observed in phenolic compounds and flavonoids contents. For soybean sprouts, these antioxidants were almost steady, while, for lupine sprouts in these conditions, the intensive synthesis of these antioxidants was observed. In response to high iron content applied from the fourth day in the cultivation media, lupine sprouts synthesize low molecular antioxidants effectively. For soybean sprouts, another mechanism of defense against oxidative stress should be expected.

Effect of jasmonic acid and yeast extract elicitation on low-molecular antioxidants and antioxidant activity of marjoram (Origanum majorana L.) [pdf

Effect of jasmonic acid and yeast extract elicitation on low-molecular antioxidants and antioxidant activity of marjoram (Origanum majorana L.) [pdf

Effect of jasmonic acid and yeast extract elicitation on low-molecular antioxidants and antioxidant activity of marjoram (Origanum majorana L.).

Elicitation, which is a way of inducing plant secondary metabolism, may be an effective method for improving the quality of plant food. The aim of this study was to determine how the application of jasmonic acid (as an abiotic elicitor) and yeast extract (as a biotic elicitor) influences the production of some bioactive compounds in marjoram and the antioxidant activity of this herb. Elicitation with 0.01 &micro;M and 1 &micro;M jasmonic acid as well as 0.1% and 1% yeast extracts was used for improving the health-benefiting quality of marjoram. The study focused on the effects of eliciting the level of some phytochemicals and the antioxidant activity of marjoram. There were no significant differences in total phenolic content between the elicited and control plants. In turn, the elicitation with 0.1% and 1% yeast extracts caused 1.8- and 2.5-fold increases in the ascorbic acid content in marjoram leaves, respectively. Both biotic and abiotic elicitation resulted in elevation of chlorophyll content, but only the abiotic elicitor (jasmonic acid) caused a significant increase (by over 50%) in the carotenoid content of marjoram leaves. The antiradical activity of marjoram was increased by the abiotic and biotic elicitation, whereas only the abiotic elicitation resulted in improving the reducing power of this herb. In conclusion, biotic and abiotic elicitation could be an effective strategy for improving the level of some phytochemicals, as well as the antioxidant activity of marjoram. A particularly valuable finding obtained in this study is that natural elicitors e.g. yeast extract can be equally effective in elevating the content of some bioactive compounds in herbs e.g. marjoram as an abiotic one.

Insights into the chemical composition and thermo-oxidative stability of novel polyethylene copolymers containing ancillary phenolic antioxidant groups as non-migrating polyolefin stabilizer

The chemical composition and thermal characteristics of a series of novel polyethylene based sterically hindered phenolic antioxidant (PE-SHPA) copolymers were investigated using thermal analysis methods. TGA/DTG curves manifest two distinct degradation events, one at about 250 °C while the second observed at a temperature between 450 and 500 °C under oxygen atmosphere. Oxidation induction time evaluation shows a dramatic increment by increasing the first degradation event weight loss percentage. To find out whether the first degradation event stem from the presence of low molecular weight non-bonding antioxidants or not, PE-SHPA copolymers were extracted. The higher OIT values observed after the extraction confirmed the chemical bonding of SHPA moiety to the polyethylene carrier and the absence of free antioxidant groups in the copolymer. Hence, the weight loss at 250 °C was considered as an antioxidant content index in PE-SHPA to find an appropriate model for the thermal stability of copolymers produced at different conditions.

Alpha 1 Microglobulin: A Potentially Paradoxical Anti-Oxidant Agent.

Alpha 1 microglobulin is a low molecular weight heme binding antioxidant protein with interesting, and potentially important, clinical applications. However, much remains to be learned about its in vivo effects. This invited review raises a number of physiologic issues regarding this compound as it pertains to clinical use.

Foliar applications of alpha-tocopherol improves the composition of fresh pods of Vigna radiata subjected to water deficiency

Alpha-tocopherol (α-Toc), so-called vitamin E, is a low molecular weight lipophilic antioxidant that generally protects plants from stress-induced cellular oxidation. It is well known that exogenously applied α-Toc is effective in improving plant growth and developmental processes under adverse environmental conditions. The current study was performed to determine the best concentration of α-Toc [0 (no spray), 100, 200, and 300 mg L-1] that could improve the biological yield and chemical constituents of fresh green pods of mung bean (Vigna radiata) and hence their quality under varying water regimes. Foliar spray of α-Toc significantly improved total soluble proteins, chlorophyll a and b, total soluble sugars, proline, phenolics, total free amino acids, nonreducing sugars, and activities of SOD, POD, and CAT under water stress conditions. However, no prominent change was observed in reducing sugars and biological yield due to externally applied α-Toc in either mung bean cultivar subjected to either water regime. Both mung bean cultivars (Cyclone 7008 and Cyclone 8009) showed similar behavior in chlorophyll a and b, while cv. Cyclone 7008 was superior with respect to the concentrations of total soluble sugars and total free amino acids, whereas Cyclone 8009 was better in activities of CAT, SOD, and POD. Overall, externally applied 200 and 300 mg L-1 α-Toc considerably enhanced the activities of antioxidant enzymes (SOD, POD and CAT), chlorophyll a and b, proline, and total phenolic contents in both mung bean cultivars.

AN EFFECT OF THE ELECTROMAGNETIC TREATMENT ON OXIDATIVE STABILITY AND MICROBIOLOGICAL SAFETY OF MEAT SEMI-PREPARED PRODUCTS

The paper demonstrates that the use of the electromagnetic treatment based on an impact of the electromagnetic field (EMF) of the self-generating (SG) discharge increases the antioxidant activity (AOA) of beef and pork semi-prepared products in pieces. The semi-prepared products were treated using the experimental equipment that consisted of the plasma electromagnetic generator based on the self-generating (SG) discharge for generating strong electromagnetic oscillations. It was found that in the experimental samples subjected to the electromagnetic treatment, an amount of reduced glutathione, which determines the redox characteristics of the intracellular environment, and glutathione peroxidase, which protects an organism against oxidative damage, increased almost two-fold. These results suggest that the excessive development of free radicals was leveled, in particular, due to the regeneration of many cytosolic low weight molecular antioxidants. Moreover, lower level of malon dialdehyde, which characterizes lipid peroxidation, was detected in the treated semi-prepared products from beef and pork (by 10% and 2.5%, respectively,) compared to the control. The results of the study showed that an impact of the SG discharge contributed to a decrease in the microbial growth rate in the chilled semi-prepared products during storage. For example, on the 6th day, the number of mesophilic aerobic and facultative anaerobic microorganisms (QМАFАnМ)did not exceed the established indicator, which correlated with the results of the organoleptic investigations. It was found that the electromagnetic treatment did not have a significant effect on the in vitro digestibility of the semi-prepared products; that is, it did not lead to deterioration of their biological value. The performed research allows us to suggest that the use of the SG discharge is expedient for increasing shelf life of meat semi-prepared products in pieces and developing a new ecologically pure technology for meat product storage..