National Repository of Grey Literature 197 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
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...
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...
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...
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...
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...
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...
Possible changes of endoglin expression in endothelial cells.
Tripská, Katarína ; Nachtigal, Petr (advisor) ; Mladěnka, Přemysl (referee) ; Vohnout, Branislav (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Doctoral Degree Program: Pharmacology and Toxicology Candidate: Mgr. Katarína Tripská Supervisor: prof. PharmDr. Petr Nachtigal, Ph.D. Title of Doctoral Thesis: Possible changes of endoglin expression in endothelial cells Endoglin (Eng) is a co-receptor for ligands of the Transforming Growth Factor β superfamily. Multiple studies have demonstrated that Eng is associated with metabolic syndrome-related pathological conditions, such as hypercholesterolemia, hyperglycemia, hypertension, or obesity. However, the exact role of Eng in these pathologies is still unknown. Therefore, the main purpose of this thesis was to elucidate and summarize the role of membrane and soluble Eng in the selected pathologies associated with metabolic syndrome. We demonstrated that soluble Eng (sEng) levels, together with plasma lipids and markers of inflammation, were reduced after every lipoprotein apheresis in patients with familial hypercholesterolemia. This result, in combination with knowledge acquired by the review article, indicates that increased sEng levels are associated with cardiometabolic disorders. Regarding the role of membrane Eng, we showed that blockage of Eng expression by TRC105 results in a decrease...
Possible changes of endoglin expression in endothelial cells.
Tripská, Katarína ; Nachtigal, Petr (advisor) ; Mladěnka, Přemysl (referee) ; Vohnout, Branislav (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Doctoral Degree Program: Pharmacology and Toxicology Candidate: Mgr. Katarína Tripská Supervisor: prof. PharmDr. Petr Nachtigal, Ph.D. Title of Doctoral Thesis: Possible changes of endoglin expression in endothelial cells Endoglin (Eng) is a co-receptor for ligands of the Transforming Growth Factor β superfamily. Multiple studies have demonstrated that Eng is associated with metabolic syndrome-related pathological conditions, such as hypercholesterolemia, hyperglycemia, hypertension, or obesity. However, the exact role of Eng in these pathologies is still unknown. Therefore, the main purpose of this thesis was to elucidate and summarize the role of membrane and soluble Eng in the selected pathologies associated with metabolic syndrome. We demonstrated that soluble Eng (sEng) levels, together with plasma lipids and markers of inflammation, were reduced after every lipoprotein apheresis in patients with familial hypercholesterolemia. This result, in combination with knowledge acquired by the review article, indicates that increased sEng levels are associated with cardiometabolic disorders. Regarding the role of membrane Eng, we showed that blockage of Eng expression by TRC105 results in a decrease...
Search for an efficient cobalt chelator
Nosková, Karolína ; Mladěnka, Přemysl (advisor) ; Smutný, Tomáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Karolína Nosková Supervisor: prof. Přemysl Mladěnka, PharmD., Ph.D. Consultant: Monika Moravcová, MSc. Title of diploma thesis: Search for an efficient cobalt chelator Cobalt, as part of vitamin B12, is an essential trace element for human organism. However, long-term exposure to high doses leads to toxicity. Chronic cobalt intoxication is currently most commonly observed after the implantation of cobalt-containing prostheses, which in some cases do not work properly and cobalt is released from them by mechanical friction or corrosion. That not only leads to a local reaction, but cobalt ions also enter the blood and lymphatic circulation and thus cause a systemic reaction. The intoxication is then manifested by neurological, cardiovascular and endocrine symptoms, which can lead to irreversible changes or even to the death. However, a chelator that would be able to effectively and selectively bind cobalt and thus effectively treat intoxication is not available in clinical practice. The aim of this thesis was a search for an efficient cobalt chelator among known metal chelators. Chelation was measured in vitro by a method based on spectrophotometric detection of unchelated cobalt ions at...
The copper - chelating activity of xanthen-3-ones derivates
Uramová, Daniela ; Mladěnka, Přemysl (advisor) ; Smutná, Lucie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Daniela Uramová, MSc. Supervisor: Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title: The copper - chelating activity of xanthen-3-ones derivates As a biogenic element, copper participates in many metabolic processes in the human body, it is a part of several enzymes, and its presence is therefore essential for life. On the other hand, free atoms of copper increase the formation of free radicals, and hence copper can be toxic to the body. Therefore, current research has being testing several substances that could be able to interact with copper ions and thus affect its dyshomeostasis in the body. Polyphenolic xanthones seem interesting, as they possess in addition to these properties also show other positive effects. The aim of this work was to evaluate the copper-chelating activity of ten closely structurally related synthetic derivates of xanthen-3-ones. The spectrophotometric measurement was carried out in vitro using the hematoxylin and bathocuproine method. 2,6,7-trihydroxy-xanthene-3-one derivates were shown to be able to chelate copper at all tested pH conditions (5.5; 6.8 and 7.5). However, in a more competitive environment, the resulting complexes are unstable. In some cases, it was...

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