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Mutagenic and Antimutagenic Effect of Environmental Substances
Langová, Martina ; Vodička, Pavel (advisor) ; Sedmíková, Markéta (referee) ; Novotná, Božena (referee)
In the present study were used reference mutagens which effects mutagenic activity in prokaryotic and eukaryotic testing systems. Aflatoxin B1 (AFB1) is one of the most thoroughly studied and the well known mycotoxin with carcinogenic activity. 2-Amino-3-methylimidazol[4,5-f] quinoline (IQ) in isolated form has been used as another reference mutagen. These compounds are indirect acting genotoxins, i.e. need metabolic activation to exert genotoxic effect. As a third reference mutagen in the present study there has been chosen N-nitroso-N-methylurea (MNU) which is direct acting carcinogenic N-nitroso compound. The aim of the study was to investigate antimutagenic effects of ellagic acide (EA), resveratrol (RES), diallyl sulfide (DAS) and phenetyl isothiocyanate (PEITC) on the mutagenicity of the mutagens. The Ames test with Salmonella typhimurium TA98 and TA100 strains was used for the evaluation of antimutagenic effect of EA, RES, DAS and PEITC in vitro.
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Evaluation of antioxidant effect using different analytical methods
Kristinová, Věra ; Mozuraityte, Revilija (referee) ; Rustad, Turid (advisor)
Cílem diplomové práce je zhodnotit antioxidační účinky pěti různých sloučenin s potenciálním využitím jako antioxidanty v potravinách (propylgalát, kávová kyselina, ferulová kyselina, p-kumarová kyselina a L(+)-askorbová kyselina), a to prostřednictvím čtyř běžně používaných testů antioxidační kapacity (FC, FRAP, DPPH, ABTS) a v modelovém systému liposomů za použití volného železa (Fe2+, Fe3+) a hovězího hemoglobinu jako prooxidantů se zvláštním zaměřením na různé koncentrace testovaných sloučenin v systému. K nepřetržitému monitorování oxidace lipidů při pH 5,5 a teplotě 30 °C je použita spotřeba kyslíku. Výsledky této práce mají přispět k lepšímu pochopení základních pro- a antioxidačních mechanismů a faktorů ovlivňující oxidaci buněčných membrán, liposomálních roztoků a emulzí typu olej-ve-vodě stabilizovaných fosfolipidy.
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Study of flavonoids in preparations registered in the Czech Republic.
Relovská, Magdalena ; Spilková, Jiřina (advisor) ; Kašparová, Marie (referee)
The flavonoids are compouns of the plant origin. They have a signifficant importance for the plants. They entice pollinaters, protect the plants against ultraviolet radiation a free radicals. The flavonoids are compound derived from phenylchroman. The basic structure is formed from 2-phenylchroman. If the phenyl is located in the position 3, they are named isoflavans and if it is located in the position 4, they are named neoflavans. The flavonoids were, are and still will studied from the point of their properties and effects and their probable using in the prevention and treatment of some diseases. In the present time they are used for their venopreventative effects. They are the components of food supplements, but also of the registrated drugs that are used in phlebology, respective they are combined with proteolytic enzymes. The results of the many studies show, that flavonoids have many various effects to live organism. They have signifficant antioxidant activity, have antivirotic, antibacterial and antimycotic activity, they act as antiinflammatory agents, have antiallergic effect, could decrease the blood pressure and the cholesterol level, act as inhibitors of many enzymes, have antimutagenic and anticancer effects. We also have information, that they have antidiabetic, antiadipogenic and...
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Multi-experimental Characterization of Grape Skins' Extracts
Šťavíková, Lenka ; Brezová, Vlasta (referee) ; Šilhar,, Stanislav (referee) ; Omelková, Jiřina (advisor)
The determination of anthocyanins in red grapes and wines has been of increasing interest in the last years, as they play an important role in colour quality of red wines revealing also many human health beneficial effects. They contribute e.g. to the reduction of coronary heart disease, but exhibit also antimutagenic, anti-inflammatory, anti-carcinogenic and antioxidant properties. In this doctoral thesis, the complex study of grape skin alcoholic and water extracts, prepared from Alibernet and St. Laurent wine grape varieties is presented. Extracts were prepared from three different amounts (0,5; 1,0 and 1,5 g) of lyophilized grape skin powder using the Pressurized fluid extraction (PFE) and the Pressurized Hot Water Extraction (PHWE) at different temperatures ranging from 40 up to 120°C and pressure of 15 MPa. Methanol, ethanol and water were used as a solvents. Total phenolic compound content (TPC) of individual extracts was determined using the Folin-Ciocalteau assay and their tristimulus color values (CIE Lab) were estimated, using the UV-VIS spectrophotometer. The identification and quantification of anthocyanins by high-performance liquid chromatography with diode array detection (HPLC-DAD) was performed. In addition, pH values of all extracts were also measured using the combinated glass electrode. Antioxidant activity of extracts was tested by EPR spectroscopy in Fenton system (H2O2/Fe2+) generating reactive radicals (•OH, O2-•, •CH3) followed by spin trapping technique, using 5,5-dimethylpyrroline-N-oxide (DMPO) as spin trap. In addition, radical scavenging activity of extracts was assessed applying 2,2-diphenyl-1-picrylhydrazyl (•DPPH) free radical and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) cation radical (ABTS•+) assays. All the experimental data were processed with principal component analysis (PCA) and canonical discriminant analysis (CDA) to specify the optimum extraction conditions for extract preparation from the perspective of the potential further application of the extracts as food supplements or food colour enhancers. The results indicated that grape skins of both varieties are a promising source of anthocyanins with prospective application in food industry.
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Modulatory effects of apigenin and luteolin on cytochrome P4501A expression and activity in intestinal cells
Šalovská, Barbora ; Boušová, Iva (referee) ; Skálová, Lenka (advisor)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Title, Name, Surname of candidate: Barbora Šalovská Title, Name, Surname of tutor: Doc. RNDr. Lenka Skálová, Ph.D. Title of diploma thesis: Modulation effects of apigenin and luteolin on activity and expression of cytochrome P4501A2 in intestinal cells Flavonoids are a large group of polyphenolic compounds that occur naturally in plant kingdom. They have been shown to posses a variety of biological activities including anti-inflammatory, anti-oxidant and anti-mutagenic effects and play a prominent role in cancer prevention. The aim of this work was research of the effect of flavones apigenin and luteolin on an activity and expression of subfamily 1A of cytochromes P450 in human colon cancer cell line HCT-8. The CYP1A isozymes enzymatic activity was measured by EROD/MROD activity assay; the quantity of CYP1A's protein was set by Western blotting. We found out that apigenin and luteolin significantly decreased CYP1A activity in HCT-8 cells. During synchronous application of model inductor CYP1A β-naftoflavon (β-NF) with apigenin or luteolin (at the concentrations of 5µM and higher), the induction effect of β-NF on CYP1A was reduced. Apigenin and luteolin significantly decreased the CYP1A activity...
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Vliv antioxidantů na zdraví člověka
Hoferková, Adéla
Lately, antioxidants are getting attention in connection with the nutrition and people's health and are interesting for food and health professionals. They are particularly important for the prevention of starting and against causes from free radicals. If the free radicals accumulates in one's body, it leads to worsening human's health condition. In the form of research, this thesis explain natural and synthetic antioxidants. It mainly deals with the characteristics and effects on human health. The first part describes the free radicals, the possibility of monitoring them and diseases caused by free radicals. In the further part of this work, we can find the distribution of natural antioxidants, where the vitamins are divided, trace elements, carotenoids, phenolic antioxidants, ginkgo biloba etc. Among the synthetic antioxidants are included BHA, BHT, TBHQ, gallates and fumaric acid.
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Cereals - Active Substances, Biological Effects and Selected Applications in Food Industry
Lichnová, Andrea ; Tremlová, Bohuslava (referee) ; Vávrová, Milada (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on the study of the biological effects of active compounds found in cereals, on the development of methods of analysis these effects, on the determination of the content of active substances and characterization of the relationship between composition and biological effects of cereals and cereal products. For the analysis several kinds of raw cereal samples (flakes, flour, germ, bran), flavored extruded cereal products and also samples of paddy and husked rice were chosen. To major types of analysed active compounds belong mainly phenolic compounds in the form of glycosides and aglycones, and also saccharides. Group parameters such as total polyphenols, flavonoids and total and reducing saccharides were determined spectrophotometrically, individual phenolics and saccharides were determined by high performance liquid chromatography (HPLC). TEAC, DPPH and CLAMS methods were used to determine the antioxidant activity. Indirect methods of determination of substances with antioxidant effect were used as well. Results of the total antioxidant activity were compared with values of antimutagenic/genotoxic activity obtained by several microbial test systems. Antimutagenic effect was expressed as a percentage of inhibition of effect of standard mutagen and could be considered as a potential preventive effect of cereals to DNA arising primarily by free radicals effect. The highest values of group and individual phenolics, antioxidant and antimutagenic activity were found in germs, bran, in buckwheat products and in coloured and raw rice. In flavoured cereal products addition of chocolate or fruit positively influences content of active phenolic substances as well as sugars, antixidant and antimutagenic activity. In a representative sample of Czech population, questionnairy study was performed to monitor interest in cereals and consumer preferences. The most of consumers consider cereals with chocolate flavour as less healthy than confirmed results of laboratory analyses. In this study some new food products were developed. Several types of model cereal products containing plant (fruit, vegetables) extracts were proposed. Extracts were added to cereals in freeze-dried and encapsulated form. The highest positive effect exhibited addition of local forrest fruit extract. Within preparation of encapsulated extracts several methods of preparing lipid or saccharides particles were also tested. The encapsulation efficiency of the methods and stability and size of particles were analysed. Optimal type of fortified cereal foods could be suggested based on the acquired results. Selected cereals were used as alternative carbon substrates (processed or raw) for the cultivation of microorganisms to produce enriched biomass usable in the feed industry. We can conclude that cereals in raw as well as processed form belong to universal foods and rich sources of biologically active substances. They can be processed by many ways. They can be used for direct consumption, as a part of new products and also undirectly as a substrate for feedstock.
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Study of antioxidants in dried fruits.
Barošová, Michaela ; Drábková,, Michaela (referee) ; Márová, Ivana (advisor)
Presented diploma work is focused on study of antioxidants in different kinds of dried fruits. Analyses of ascorbate, tocopherols, carotenoids and flavonoids were performed using RP-HPLC with spectrophotometric detection. Analysis of dried fruits showed high level of vitamins and phenolocs mainly in berries. High level of carotenoids was observed in dried apricots and plums. Further, antioxidant activity of dried fruit extracts was tested by ABTS method. High antioxidant activity was found mainly in dried apples, cranberries and blueberries. The biological test with yeast Sascharomyces cerevisiae D7 was used for the analysis of antimutagenic efects of dried fruits. High antimutagenic activity exhibited dried cranberries and blueberries. Most of tested dried fruits with high antimutagenic effect exhibited also high antioxidant activity as well as high content of some antioxidants. No direct correlation was found among these parameters. Last part of this work was focused on study of influence of drying on antioxidant content in two types of apples. Drying at mild controlled conditions exhibited no significant negative effect on active substance content; in some samples their concentration was observed.
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Antioxidative substances in selected fruit and herbal teas
Tomková, Martina ; Buňková, Radka (referee) ; Márová, Ivana (advisor)
This diploma project deals with antioxidant and antimutagenic properties of selected herbal and fruit teas commonly used in Czech population. Influence of different tea packaging (bag teas and loose leaf teas) on bioactive compound content was compared. Further, effect of long-term storage in common household conditions was studied. Antioxidant properties of teas were characterized using some group parameters - total antioxidant activity ("Randox Total Antioxidant Status Kit"), total phenolics and total flavonoids - as well as some individual representatives of low molecular weight antioxidants. Higher antixidant content was found in herbal teas than in fruit teas. Comparing bag teas with loose leaf teas higher antioxidant activity was shown in loose leaf teas. Individual antioxidants were analyzed using HPLC method with spectrophotometric detection and verified by on-line LC/MS. IN all tea samples catechins - catechin, epicatechin, epicatechin gallate and other flavonoids - rutin, morin, quercetin, kaempferol, myricetin and luteolin were determined. In most of teas high level of catechin and rutin was detected. The highest level of flavonoids was determined in herbal poured teas. Ascorbic acid content was also determined by HPLC method. Higher vitamine C level was found in most of fruit teas and in rose hip tea. Antimutagenicity of tea extracts was tested by in vitro test using Saccharomyces cerevisiae D7 yeast. High antimutagenic activity showed mainly nettle tea, tutsan tea and most of fruit teas. During long-term storage (1 year, 20°C, darkness) a significant decrease of all analyzed antioxidant parameters was followed. Higher lost of antioxidants was found in fruit teas when compared with the herbal ones.
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