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Electrophoretic determination of oxidized and reduced form of glutathion in plant material
Durychová, Eva ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
This work is based on a previously published method for the determination of twenty proteinogenic amino acids by capillary electrophoresis with contactless conductivity detection and deals with possibility of its use for the determination of oxidized (GSSG) and reduced (GSH) forms of glutathione with amino acids. The theoretical part firstly deals with brief introduction of the properties and importance of glutathione and its protection against autooxidation, especially by alkylation with N-ethylmaleimide (NEM), which binds to GSH to form its alkylated form (GSH-NEM). Then, a brief summary of the available methods for determination of glutathione is given, with a focus on the already developed capillary zone electrophoresis methods. Finally, it briefly presents the electrophoretic method for the determination of twenty proteinogenic amino acids on which this work is based. In the experimental part, the integration of the determination of both forms of glutathione into the method for the determination of proteinogenic amino acids is presented. First, a simplified, less time consuming method was tested in shorter 50.0 cm capillary without hydroxyethylcellulose, where both forms of glutathione were separated at baseline within 10 minutes. Relative standard deviations of peak areas (GSH 2.1%; GSSG...
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Studium vlivu požití kávy na antioxidační stav organismu
Prucková, Zdeňka
The theoretical part deals with the characterization of coffee, its production, chemical composition of grain and coffee swallowed impact on the health of an organism. It also deals with antioxidants, their division and their effects on the human body. There is described glutathione, one of the most important antioxidant in the blood. The practical part is engaged in an experiment consisting of the capillary blood collection and subsequent determination of thiol groups Ellman method, determine the total content of reduced glutathione by high performance liquid chromatography with electrochemical detection and determination of total protein content in blood by the Bradford method,. All results are shown in graphs. Contents of glutathion and thiol groups with regular consumption of coffee increased, protein content did not change. In the last part of the experiment, sensoric analysis of the test sample of instant coffee was carried out. Coffee was rated as average, because the overall impression was rated an average of 52.7 points.
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Význam glutathionu v hormonální regulaci odpovědi na stres u Arabidopsis thaliana
Šlapáková, Martina
Tripeptide glutathione plays a key role in combating stresses such as heavy metal or xenobi-otic exposure. Recent studies have shown that glutathione content is negatively modulated by cytokinin. Thus, glutathione may be intimately involved in enhanced stress tolerance displayed in cytokinin-deficient plants. To probe the physiological relevance of the crosstalk between cytokinin and glutathione, a response to a glutahione-depleting xenobiotic 1-chloro-2,4-dinitrobenzene (CDNB) was analysed in the model plant Arabidopsis thaliana. Here we show that CDNB causes decrease of cytokinin status. We found that transgenic plants with reduced endogenous cytokinin levels showed a CDNB-tolerant phenotype. Cy-tokinin depletion provoked the accumulation glutathione. Glutathione-deficiency abolishes CDNB tolerance of cytokinin-deficient plants supporting an essencial role of glutathione for CDNB sequestration. Our findings indicate that cytokinin is an important regulatory factor in plant adaptation to CDNB stress.
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Alternativy k SO2
Měřínská, Iva
The bachelor thesis describes the issue of sulfur dioxide and substances proposed for its replacement. The theoretical part defines the basic problem areas - the usage of sulfur dioxide in wine-making, forms of sulfur dioxide in wine, methods of application, impacts on human health and methods to reduce sulfur dioxide in wine. The practical part is focusing on the experiment which was executed excluding the usage of sulfur dioxide during the vinification. The resulting wines are monitored from the analytical and sensory point of view. The measured results are adequately evaluated at the end of the thesis.
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Vliv zdroje selenu na antioxidační potenciál laboratorních potkanů
Buriánková, Markéta
Buriánková M.: Influence of the selenium source on the antioxidant potential of laboratory rats. Diploma thesis, MENDELU, Brno, 90 p. The aim of this thesis was to experimentally determine influence of various forms (nanoselenium, nanoselenium modified by glucose) and levels of selenium (0 mg, 0,02 mg and 0,02 mg of selenium/organism/day + 0,1 mg of glucose/organism/day) on antioxidant potential of model animals - rats. It was used 18 laboratory rat males of outbreeding base Wistar albino, which were separated to three groups. In groups with application of nanoselenium itself the beneficial effect to the final concentration of selenium in plasma and intestines was confirmed (P < 0,05) in contrast to check (without supplementation). In groups treated by nanoselenium modified by glucose had significantly (P < 0,05) beneficial effect on blood with increase by 78,1 % and on liver by 111,3 % in comparison with check. Applied nanoselenium in both groups increased final concentration of selenium in tissues. The supplementation of nanoselenium in other groups of rats did not significantly influenced final concentration of selenium in tissues. Antioxidant activity of tissues significantly (P < 0,05) increased in plasma of group, where the nanoselenium modified by glucose were applied, namely by 83,6 % in comparison with check. It was evaluated by antioxidant methods FR (P < 0,05) and FRAP, where most of the results were without statistical significance (P > 0,05). Both forms of nanoselenium had influence on level of reduced (GSH) and oxidized (GSSG) glutathione. In blood the significant (P < 0,05) increase of GSH level has occurred. In erythrocytes were significantly (P < 0,05) higher both groups with nanoselenium, where higher effect on level of GSH had group with nanoselenium modified by glucose, thereby the oxidation stress of organism was reduced. In liver the significant (P < 0,05) decrease of GSH in group with nanoselenium itself has occurred and in both groups the values of GSSG have significantly (P < 0,05) decreased. The results clearly show that levels of nanoselenium and nanoselenium modified by glucose increased concentration of this element in tissues of animal organism, increased antioxidant activity in plasma and also increased level of GSH in blood and erythrocytes.
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Vliv taurinu na biochemické ukazatele v orgánech laboratorních potkanů
Mrázková, Martina
The aim of this dissertation was to valorize the effect of various levels of taurine on the antioxidant status in rats body, monitor serum taurine and individual aminoacids in selectedorgans. This dissertation valorize the influence of taurine in the rats liver and brain after its application into feed mixtures. The effect of taurine was monitored on the ratio of GSH / GSSG,concentration of metallothionein and taurine. To this experiment were used 48 Wistar male rats, which were divided into eight groups (n = 6). During four weeks feed mixtures were given to these rats enriched with taurin eat a dose of 0, 1000, 1500, 2000 2500, 3000, 3500 and 4000 mg / kg / diet. Animals accepted diet and drinking water ad libitum. Average consumption of feed mixtures were 35 grams per day. Application taurine in creased concentration of taurine in the organism, which has an positive effect on antioxidant mechanisms of the organism. In deed we can not confirm that the addition of taurine in to the diet increases the concentrations of metallothionein and glutathione in the organism. In the brain was found increasing ratio of GSH / GSSG and reduced concentration of metallothionein. The other way around in the liver was reduction ratio of GSH / GSSG and increasing concentration of metallothionein.
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Role cytokininů v regulaci odpovědi na nedostatek síry u Arabidopsis thaliana
Štuříková, Helena
Sulfur deficiency stress induces a number of adaptive responses which must be coordinated. Phytohormone cytokinin has been previously shown to regulate sulfur aquisition and utilizati-on, however, the cytokinin-regulation of sulfur nutrition remains elusive. In this diploma the-sis, it was reported that cytokinin induces a sulfur-deficiency-like gene expression which is accompanied by a decrease in pool of the key sulfur-containing compound glutathione. Further, it was found that the sulfur deficiency responses involve altered cytokinin status to coordinate developmental and/or metabolic adaptations. Arabidopsis plants deficient in cytokinin signaling showed disrupted root elongation in response to sulfur starvation and, unexpectedly, the root elongation in response to sulfur starvation was further stimulated by a low cytokinin concentration. Further, the role of cytokinin in sulfur nutrition was indicated in cytokinin signaling-deficient plants which accumulated more glutathione under normal nu-tritive conditions in comparison to wild-type, and vice versa, the decrease of glutathione pool was exaggerated during sulfur starvation. Altogether, results of this diploma thesis suggest that cytokinins participate in nutritional sulfur homeostasis control.
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Biotransformation aspects on novel carbocyclic nucleoside analogs.
Rozumová, Nela ; Mertlíková Kaiserová, Helena (advisor) ; Rumlová, Michaela (referee)
Carbocyclic nucleoside analogs with norbornane moiety that have been synthesized at IOCB AS CR, represent new potential chemotherapeutic agents with significant activity against Coxsackieviruses. The main objective of this work was to study the metabolism and mechanism of action of the original analog carbocyclic nucleoside MS 254, which is characterized by its antiviral and cytostatic effects. The attention was partially paid also to the two structurally related substances (MS 255, MS 320). In this work, we determined cytotoxicity of these compounds in cell culture and the effect of MS 254 on the amount of total and oxidized glutathione, activity of glutathione-S-transferase (GST), glutathione reductase (GR) and the effect on cellular oxidative stress. The kinetics of the conjugation of MS 254 by human GST was also studied. It was found that of the three substances tested MS 255 was the most cytotoxic and MS 254 was the least cytotoxic compound. It was further found that MS 254 does not cause significant oxidative stress and that it increases the activity of GST and GR in a dose-dependent manner. Michaelis-Menten constant of the conjugation of MS 254 with the glutathione (main metabolic pathway) was determined in the milimolar range, indicating a relatively low affinity of MS 254 for GST.
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Význam glutathionu pro kvalitu hroznů a vína
Kandourova, Alexandra
Glutathione is an important constituent of grape, must, and wine. Special emphasis is given to its occurrence in grapes, must, and wine; its role as an antioxidant in wine. The effect of glutathione on aroma compounds is also outlined. There are information on the positive effects of the use of glutathione-enriched preparations in wine industry. It is evaluated its effectiveness in combination with ascorbic acid against oxidative color formation.
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Význam glutathiónu pre kvalitu hrozna a vína
Kacina, Michal
Glutathione plays important role as an antioxidant during the oxidation of white grape musts. Up to certain level, it inhibits the browning of musts and exerts a protective effect on various aroma compounds during wine ageing. Glutathione is a precursor of some aromatic volatile thiols. Glutathione content in grape ber-ries may vary according to cultivar, vintage and soil nutrients. Its concentration in the must is influenced by oxygen exposure, tyrosinase activity, grape skin maceration during the prefermentation period and pressing conditions. Its concentrations in wine are fluctuating during alcoholic fermentation. Application of glutathione together with sulfur dioxide shows synergic effect on wine stability permitting the use of lower sulfur dioxide doses. The judicious management of glutathione levels during the winemaking trial can higher the final wine quality and the length of its storage period.
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