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EN
The aim of the study was to analyse the effect of aflatoxin B₁ (AFB1) on total antioxidant status (TAS). The studies were conducted on Wistar male rats weighing 190-200 g. The animals were given for 7 d varied doses of AFB1, from 0.5 mg/kg b.w. to 2 mg/kg b.w. TAS and concentration of uric acid were determined in blood serum. The administration of AFB1 caused a decrease in TAS value, the most significant in the rats, which received the highest dose. AFB₁ disturbed the second line of defence against free radicals, which was proved by an increase in the second line defence antioxidant, i.e. uric acid.
EN
The hitherto studies on the effect of cadmium on plants have shown that it causes intensification of two types of unfavorable processes in plants: inactivation of macromolecules and cellular structures and induction of oxidative stress. In response, the plant organism activates processes restoring its homeostasis, i.e. those which remove reversible and irreversible changes. In removing the former a particular role is played by the antioxidative system containing enzymatic and nonenzymatic antioxidants, and removing the active forms of oxygen. The strategy of stress tolerance plays an important role in the plant resistance to cadmium and other toxic metals.
EN
The research has been performed on roots of Vitis vinifera, cv. Himrod, obtained from seedlings grown under chill stress conditions (+10oC in the day and +7oC at night), under optimum conditions (+25oC in the day and +18oC at night) and from seedling which underwent a recover period after the chill stress treatment. The purpose of the study has been to determine quantitative and qualitative changes in phenolic compounds as well as to demonstrate changes in antiradical properties of extracts from grapevine roots, which appeared as a result of chill stress and during recovery under the optimum conditions following the stress. Phenolic compounds from grapevine roots were extracted using 80% acetone. The total content of phenolics was determined by colorimetry. The content of tannins was tested by precipitation with bovine serum albumin. The reducing power as well as DPPH• free radical and ABTS+• cation radical scavenging activity of the extracts were also tested. In order to identify phenolic compounds present in the extracts the RP-HPLC technique was employed. The tested material was found to contain tannins and three identified phenolic acids: ferulic, caffeic and p-coumaric ones. The latter occurred in the highest concentrations (from 4.46 to 6.28 µg/g fresh matter). Ferulic acid appeared in smaller amounts (from 1.68 to 2.65 µg/g fresh matter), followed by caffeic acid (from 0.87 to 1.55 µg/g fresh matter). Significantly less total phenolic compounds occurred in roots of seedlings subjected to chill stress. However, the total content of these compounds increased significantly in roots of plants which underwent recovery after chill stress. Concentration of tannins was determined by two methods. The content of condensed tannins was depressed in roots as a result of low temperature stress, whereas the content of condensed and hydrolysing tannins (determined via the BSA method) rose under chill stress conditions. A significant increase in tannins in root extracts (determined with both methods) was found during the recovery process after the stress. The three identified phenolic acids appeared in grapevine roots as ester-bound compounds. It has been demonstrated that the content of phenolic acids significantly fell as a result of low temperatures, but increased during recovery after chill stress. The weakest ability to scavenge DPPH• and ABTS+• free radicals as well as the reducing power were shown by the extract obtained from grapevine roots from the seedlings subjected to chill stress. Both free radical scavenging activity and reducing power were observed to increase considerably during recovery after stress. This seems to prove that during the recovery process following chill stress the synthesis of antioxidative compounds in grapevine roots is much more intensive.
EN
This paper reviews plant ascorbate peroxidases (APX), an important part of the antioxidative system, maintaining the balance and uninterrupted functioning of the plant cell. The main role of APXs is to control the hydrogen peroxide concentration in cells. In reaction the enzymes use ascorbate as an electron donor. The active site is highly conserved by every member of the APX family. APXs belong to class I of the superfamily of bacterial, fungal and plant peroxidases. All the isoforms differ from each other in molecular weight, optimal pH, stability, substrate specificity, localization and level of response to specific stress conditions. It is suggested, however, that the responsible genes originated from one common gene by multiple duplication events followed by natural selection.
EN
Various studies of the components of the antioxidant protection system of microalgae D. armatus under the influence of osmotic stress and active forms of oxygen will allow to develop methods for controlling carotenogenesis in a given culture and to obtain carotenoid enriched feed for zooplankton. These studies made it possible to evaluate the activity of catalase, peroxidase enzymes in cells that are cultured under the induction of carotenogenesis by free radical oxidation promoters and osmotic stress on the background of physiological changes. It is established that under these conditions, there is an increase in volumes and aggregation of vegetative cells. At the same time, the amount of biomass remains at the level of the first day of inductors application. Against the background of a decrease in growth activity, a decrease in the number of metabolically active cells in cytochrome oxidase was observed. It is also shown that, when iron sulfate is introduced with hydrogen peroxide and sodium chloride against the background of enhanced carotenogenesis, antioxidant systems are activated by increasing the activity of catalase and peroxidase. Under such conditions, it is possible to achieve increased production of carotenoids in Desmodesmus armatus culture.
EN
The paper attempted to assess the activity of antioxidative system in cells of spinach plant, ‘Matador’ c.v., growing in the soil contaminated with Ni. Plant material for analyses was obtained from two pot experiments conducted in 2010 and 2011 in the vegetation hall of the Experimental Station of the University of Agriculture in Krakow. Ni content in the plant aboveground parts was assessed by ICP-ES method, contents of reduced glutathione form by colorimetry and ascorbic acid by titrimetric method. Nickel content in spinach aboveground parts ranged from 2.00 to 204.5 mg kg–1 d.m. and increased with growing substratum pollution with this element and usually with plant age. The plants contained from 31 to 238 g GSH g–1 f.m. In the first three objects with 0o, Io and IIo degree of substratum pollution according to IUNG classification, this antioxidant contents were higher in comparison with its amount in plants from the control and objects with lower degree of pollution. In the object with the highest nickel dose application, GSH content in plants decreased significantly in comparison with plants from the other objects, while the plants on this object died shortly after germination. Ascorbic acid content in spinach in the both years of experiments ranged from 24.13 to 73.09 mg 100 g–1 f.m. and increased in plants from the successive objects with growing substratum contamination with nickel. In the first phase of growth spinach plants contained generally much more of GSH and AsA, which indicated much better efficiency of the antioxidative system at the initial period of growth.
PL
W pracy podjęto próbę oceny aktywności systemu antyoksydacyjnego komórek roślin szpinaku odmiany ‘Matador’ rosnących w glebie zanieczyszczonej Ni. Materiał roślinny do analiz pozyskano w dwóch doświadczeniach wazonowych prowadzonych w latach 2010 i 2011 w hali wegetacyjnej stacji doświadczanej 996 Monika Arasimowicz et al Uniwersytetu Rolniczego w Krakowie. W częściach nadziemnych roślin oznaczono zawartość Ni metodą ICP-ES, zredukowanej formy glutationu metodą kolorymetryczną oraz kwasu askorbinowego metodą miareczkową. Zawartość niklu w częściach nadziemnych szpinaku wynosiła od 2,00 do 204,5 mg kg–1 s.m. i zwiększała się wraz ze stopniem zanieczyszczenia podłoża tym pierwiastkiem oraz na ogół wraz z wiekiem roślin. Rośliny zawierały od 31 do 238 g GSH g–1 ś.m. W roślinach z pierwszych trzech obiektów o zanieczyszczeniu podłoża odpowiadającym 0o, Io, IIo , według klasyfikacji IUNG, zawartość tego antyoksydantu była większa w porównaniu z zawartością GSH w roślinach z obiektu kontrolnego i obiektów o niższym stopniu zanieczyszczenia. W obiekcie z największym zastosowanym dodatkiem niklu zawartość GSH w roślinach zmniejszyła się istotnie w porównaniu z roślinami z pozostałych obiektów, a rośliny z tego obiektu obumarły niedługo po wschodach. Zawartość kwasu askorbinowego w szpinaku w obydwu latach doświadczeń mieściła się w przedziale od 24,13 do 73,09 mg 100 g–1 ś.m. i zwiększała się w roślinach z kolejnych obiektów o coraz większym zanieczyszczeniu podłoża niklem. Rośliny szpinaku w pierwszej fazie wzrostu zawierały na ogół znacznie więcej GSH i AsA, co wskazuje na znacznie wyższą sprawność systemu antyoksydacyjnego roślin w początkowym okresie wzrostu.
EN
This review deals with selected recently used analytical methods for determining the antioxidant activity of compounds being investigated as well as total antioxidant capacity of the biological samples.
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