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Are currently used chelators of heavy metals also chelators of calcium and magnesium?
Skoupilová, Karolína ; Mladěnka, Přemysl (advisor) ; Šuťák, Róbert (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Karolína Skoupilová Supervisor: prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of diploma thesis: Are currently used chelators of heavy metals also chelators of calcium and magnesium? Calcium and magnesium are important elements for the human body. Calcium plays an important role in blood clotting and intracellular signalling, thus participating in muscle contraction and platelet aggregation, among other processes. Magnesium is a cofactor for many enzymes. A significant deficiency of both ions can manifest as disorders of heart rhythm and increased neuromuscular excitability. The aim of this study was to determine the chelating activity of currently used heavy metal chelators and to determine the stability of the indicator. First, the ideal pH for the experiment was determined. In the next step, the chelation rate of 21 known metal chelators was measured using an in vitro spectrophotometric method. Finally, the chelation of the most active calcium chelators was verified on platelet aggregation in a human blood sample. At the same time, the long-term stability of the indicator o- cresolphthalein complexone (CC) was determined. In the first step, pH 7.5 was chosen, which was the only one...
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The impact of benzoic acids, metabolites of flavonoids, on the iron-catalysed Fenton reaction
Klenovičová, Alexandra ; Mladěnka, Přemysl (advisor) ; Karlíčková, Jana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Alexandra Klenovičová Supervisor: Prof. Přemysl Mladěnka, PharmDr., Ph.D. Consultant: Zuzana Lomozová, Ph.D. Title of diploma thesis: The impact of benzoic acids, metabolites of flavonoids, on the iron-catalysed Fenton reaction Oxidative stress is a condition in which there is an increased production of free radicals that exceeds endogenous antioxidant activity and leads to damage of biomolecules. A number of human diseases are associated with oxidative stress. However the use of antioxidants has failed in clinical trials, but it is possible that the fact that antioxidants may preferentially exhibit prooxidant activity under elevated antioxidant concentrations in various pathophysiological conditions. Various in vitro and epidemiological studies have confirmed the presence of antioxidant and prooxidant properties in flavonoids. However, on the basis of their pharmacokinetics, it is evident that after their oral intake, significant metabolism in the colon takes place, where small phenolic substances are formed in interaction with the intestinal microflora. There is a possibility that the antioxidant and harmful prooxidant properties that have been attributed to flavonoids are in fact a...
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The influence of LDL-apheresis on aggregation of blood platelets, blood coagulation, and the effect of standard drugs.
Černotová, Veronika ; Mladěnka, Přemysl (advisor) ; Čečková, Martina (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Veronika Černotová Supervisor: prof. Přemysl Mladěnka, PharmD., Ph.D. Consultant: Lukáš Konečný, MSc. Title of diploma thesis: The influence of LDL-apheresis on aggregation of blood platelets, blood coagulation and the effect of standard drugs LDL-apheresis is a method that removes LDL-cholesterol (LDL-C) from the blood. It is used to treat familial hypercholesterolemia (FH), a genetic disorder causing high LDL-C levels and an early development of cardiovascular diseases. Blood platelets and coagulation system play an important role in these diseases and their activity is also affected by lipids. The aim of this thesis was to analyze possible differences in platelet aggregation and blood coagulation in patients suffering from FH. Two methods of treatment in this group were compared - lipid apheresis and PCSK9Ab (proprotein convertase subtilisin/kexin type 9 monoclonal antibodies). The observed parameters were also compared with age-matched healthy volunteers. Our cohort consisted of 15 patients and 15 healthy donors. Six patients were treated with lipid apheresis and also PCSK9Ab, six subjects only with PCSK9Ab. Platelet aggregation was measured with an impedance aggregometer using 7 different...
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Copper metabolism in Acanthamoeba castellanii
Doležalová, Taťána ; Šuťák, Róbert (advisor) ; Mladěnka, Přemysl (referee)
Copper is an essential element that, due to its redox properties, is involved as a cofactor in many enzymes, the most well-known example is the cytochrome c oxidase. At the same time, in higher concentrations, this element shows toxic effects on several levels, it can disrupt iron-sulfur clusters, damage proteins and lead to cell death. This is the reason why this thesis studies copper metabolism in the parasitic amoeba Acanthamoeba castellanii, which causes serious diseases such as acanthamoeba keratitis or granulomatous amoebic encephalitis. Understanding how copper homeostasis is maintained in this organism could lead to targeted disruption of this balance and the exploitation of the toxic effects of copper. In this work, the function of the P-type ATPase homologous to CCC2 from Saccharomyces cerevisiae, responsible for the transfer of copper ions from the cytoplasm to the Golgi apparatus, was characterized by functional complementation. Furthermore, a carrier from the Ctr family has been described that transfers copper ions presumably across the cytoplasmic membrane. The expression of these carriers was monitored in copper excess and deficiency. To get a better picture of how A. castellanii maintains copper homeostasis, the cellular accumulation of copper and the ability of this amoeba to deal...
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Interactions of natural phenolic compounds with biogenic metals
Lomozová, Zuzana ; Mladěnka, Přemysl (advisor) ; Bittner Fialová, Silvia (referee) ; Patočka, Jiří (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Zuzana Lomozová, MSc. Supervisor: Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of Doctoral Thesis: Interactions of natural phenolic compounds with biogenic metals Phenolic compounds are one of the most widely distributed groups of secondary plant metabolites. They are an integral part of the human diet and their consumption is associated with a number of positive effects. They include a wide range of substances, from simple molecules such as phenolic acids to large polymeric compounds such as tannins. Because of their structure, which includes, among others, free hydroxyl groups, they are able to interact with biogenic metals and form metal complexes with them. Under normal conditions, the homeostasis of these transition metals in the body is tightly regulated, but it can be disturbed in pathological conditions such as acute myocardial infarction, when the levels of free iron and copper increase as a result of a significant decrease in pH. Similar metal imbalance is observed as well as in inflammatory and neurodegenerative diseases, tumours, or diabetes mellitus. The aim of this dissertation was to find out how these substances react with biogenic metals using in vitro and ex...
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The influence of metabolites and their parent phenolic compounds on blood platelets
Hrubša, Marcel ; Mladěnka, Přemysl (advisor) ; Moťovská, Zuzana (referee) ; Kollár, Peter (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmacology and Toxicology Candidate: Mgr. Marcel Hrubša Supervisor: Prof. PharmDr. Přemysl Mladěnka, Ph.D. Title of dissertation thesis: The influence of metabolites and their parent phenolic compounds on blood platelets Acute cardiovascular events (ACEs), such as stroke and acute coronary syndromes encompassing acute myocardial infarction, are one of the main causes of cardiovascular mortality in the world. Current pharmacotherapy focuses primarily on secondary prevention of their recurrence, where antiplatelet drugs play a key role. These drugs reduce platelet hyperreactivity, which is present in the majority of cardiovascular and metabolic diseases, and significantly decrease the risk of ACEs. However, the palette of currently available drugs faces many issues, such as resistance, high variability in both pharmacokinetics and pharmacodynamics, serious side effects and the route of administration. This thesis firstly briefly summarizes the current knowledge of platelet physiology along with available antiplatelet drugs and their mechanism of action. Second part of the theoretical introduction is dedicated to polyphenolic compounds, as polyphenol-rich diet is associated with many beneficial effects, particularly...
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Interactions of natural phenolic compounds with biogenic metals
Lomozová, Zuzana ; Mladěnka, Přemysl (advisor) ; Bittner Fialová, Silvia (referee) ; Patočka, Jiří (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Zuzana Lomozová, MSc. Supervisor: Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of Doctoral Thesis: Interactions of natural phenolic compounds with biogenic metals Phenolic compounds are one of the most widely distributed groups of secondary plant metabolites. They are an integral part of the human diet and their consumption is associated with a number of positive effects. They include a wide range of substances, from simple molecules such as phenolic acids to large polymeric compounds such as tannins. Because of their structure, which includes, among others, free hydroxyl groups, they are able to interact with biogenic metals and form metal complexes with them. Under normal conditions, the homeostasis of these transition metals in the body is tightly regulated, but it can be disturbed in pathological conditions such as acute myocardial infarction, when the levels of free iron and copper increase as a result of a significant decrease in pH. Similar metal imbalance is observed as well as in inflammatory and neurodegenerative diseases, tumours, or diabetes mellitus. The aim of this dissertation was to find out how these substances react with biogenic metals using in vitro and ex...
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Chelation of copper ions by thiol containing chelators
Kladivová, Andrea ; Mladěnka, Přemysl (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Andrea Kladivová Consultant: Václav Tvrdý, MSc. Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of diploma thesis: Chelation of copper ions by thiol containing chelators Copper is an essential trace element that is important for many physiological functions. On the other hand, disruption of copper homeostasis associated with its elevated level is dangerous for the organism, because of the formation of free radicals. Copper chelators can represent an effective tool in the treatment of such conditions. Due to the ability of a thiol group to bind metal ions and form a chelate, thiol containing chelators are promising compounds for the reduction of copper levels. Within this diploma thesis, four compounds containing a thiol group were tested for the ability to chelate copper ions. Spectrophotometric measurement was used for this determination. It is a simple, fast but precise method for determination of the chelation properties in vitro. In addition, the ability of these compounds to reduce cupric ions was examined. When using the basic hematoxylin method, all the tested substances proved they can chelate copper. Their efficacy was practically identical except for the...
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The impact of synthetic chelators from the group of 4-acylpyrazole-5-ones on alcohol dehydrogenase
Sobolová, Zuzana ; Mladěnka, Přemysl (advisor) ; Jirkovský, Eduard (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Zuzana Sobolová Supervisor: Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Consultant: Marcel Hrubša, MS.c. Title of diploma thesis: The impact of synthetic chelators from the group of 4-acylpyrazole-5-ones on alcohol dehydrogenase Inhibitors of alcohol dehydrogenase play a key role in the treatment of poisoning caused by methanol, ethanol, ethylene glycol, and their toxic metabolites. Such treatment can therefore be considered as life-saving. In clinical practice, a single substance, fomepizole, is used. This thesis is aimed at investigation of the effect of eleven experimental chelators from the 4- acylpyrazol-5-ones group on equine and yeast alcohol dehydrogenases, and the possible definition of structural features that would be the most suitable for interaction with this enzyme. Due to the ability of these substances to chelate zinc ions, it is believed that they could inhibit an enzyme that has a zinc molecule in the structure. The measurement itself is based on principle of increase in absorbance during the enzymatic reaction, which is caused by the formation of NADH. This measurement is relatively simple, efficient and, due to used kinetic method, also less susceptible to be affected by...
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Interactions of rifampicin derivatives with pregnane X receptor and OATP1B1 transporter
Krajníková, Zdeňka ; Smutný, Tomáš (advisor) ; Mladěnka, Přemysl (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Zdeňka Krajníková Supervisor: PharmDr. Tomáš Smutný, Ph.D. Title of diploma thesis: Interactions of rifampicin derivatives with pregnane X receptor and OATP1B1 transporter Pregnane X receptor (PXR) is a ligand-activated transcription factor, which regulates gene expression in the liver. Among PXR target genes, cytochrome P450 3A4 (CYP3A4) is the most important enzyme responsible for metabolism of clinically used drugs. Rifampicin (RIF) is a prototype PXR ligand. It enters hepatocytes across the basolateral membrane by OATP1B1 transporter. Noteworthy, RIF is a chemically unstable molecule. Additionally, it is also metabolized in the human body. In this diploma thesis, we decided to determine the affinity of RIF derivatives (i.e. rifampicin quinone, rifampicin N-oxide, 25-desacetylrifampicin, and 3-formylrifamycin SV) to PXR and OATP1B1, which has not been explored in details so far. For this, two hybrid and gene reporter assays were employed. As revealed by two hybrid assay, rifampicin quinone, rifampicin N-oxide, and 3- formylrifamycin SV (10 µM) activated PXR at a level comparable with RIF (positive control). Contrary, 25-desacetylrifampicin showed a lower affinity to PXR than that...
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