National Repository of Grey Literature 80 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Determination of the stoichiometry of the copper complexes with dehydrosilybine A
Klimková, Kateřina ; Mladěnka, Přemysl (advisor) ; Hrdina, Radomír (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Kateřina Klimková Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm. D., Ph.D. Consultant: Assoc. Prof. Kateřina Valentová, Ph.D. Title of Thesis: Determination of the stoichiometry of the copper complexes with dehydrosilybin A Silymarin, the standardized extract of the milk thistle (Silybum marianum), is a widely used approved over-the-counter drug that is recommended for a number of liver diseases. Silymarin contains as one of its components 2,3-dehydrosilybinA, which has an appropriate metal binding site in its structure. In general, flavonolignans, due to their structure, can interact with transition metals in the gastrointestinal tract by forming complexes. This property can be useful for the protection against excessive amounts of metals in the body. The aim of this in vitro study was to analyse the interaction of 2,3-dehydrosilybin A with copper, which plays a crucial role in the organism as a cofactor of many enzymes. Although being an essential element, it can, however, be toxic at elevated levels. Stoichiometry, as one of the most important characteristics of the complex, was determined by UV-Vis spectrophotometry in four (patho)physiological pH conditions (4.5; 5.5; 6.8; 7.5)...
Interference of reducing agents with the hematoxylin assay for determination of cupric chelation
Zsáková, Emily ; Mladěnka, Přemysl (advisor) ; Vorčáková, Katarína (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Emily Zsáková Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of diploma thesis: Interference of reducing agents with the hematoxylin assay for determination of cupric chelation Copper is an essential trace element of living organisms. Disorders of its homeostasis affect various pathological conditions. In excessive amounts, it is toxic due to its ability to form free radicals. Vitamin C, trolox (a water soluble form of vitamin E), glutathione and hydroxylamine possess reducing properties that protect our body from oxidative tissue damage. Oxidized glutathione (GSSG) was also tested for comparison. The object of study was to test the chelating ability of these substances. A simple and fast spectrophotometric method was used. The combination of reducing properties of copper and chelating agents could lead to an improvement in chelation therapy either in heavy metal poisoning, treatment of Wilson's disease, or other diseases. We found that all substances were chelators/copper-chelating agents in vitro in a slightly competitive environment, using hematoxylin as an indicator. However, by using the bathocuproine assays to verify chelating properties, none of the substances...
Effect of cholinesterase inhibitors on monoaminergic system and energic metabolism
Kalinová, Tereza ; Mladěnka, Přemysl (advisor) ; Štěpánková, Šárka (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Tereza Kalinová Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Mentor: Assoc. Prof. Jana Hroudová, Pharm.D., Ph.D. Title of diploma thesis: Effect of cholinesterase inhibitors on monoaminergic system and energy metabolism Cholinesterase (ChE) inhibitors play an essential role in the treatment of Alzheimer's disease (AD). They effect positively cognitive, functional and behavior symptoms of AD. Up to date, donepezil, rivastigmine and galantamine represent the only ChE inhibitors approved for AD treatment. The first ChE inhibitor was tacrine, which was withdrawn from market due to its toxicity and adverse effects. Recently, novel tacrine and 7-methoxytacrine (7-MEOTA) derivatives were synthetized and extensively investigated to find less toxic compounds affecting pathological mechanisms associated with development of AD. There is less known about effects of these drugs on mitochondrial functions and cellular energy metabolism. The aim of this project is to examine in vitro effects of ChE inhibitors on energy metabolism and cellular respiration, specifically on mitochondrial electron transport chain complexes and an enzyme of the citric acid cycle - citrate synthase. Inhibitory effects...
Ability of copper chelators to interact with iron and zinc
Hanuščinová, Lucia ; Mladěnka, Přemysl (advisor) ; Čonka, Patrik (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lucia Hanuščinová Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmDr., PhD. Title of diploma thesis: Ability of copper chelators to interact with iron and zinc Copper plays in the human organism a role of an element with indispensable significance, whose biological influence and effects depend on its quantity. With elevated concentrations in the human body, copper becomes toxic, resulting in pathological conditions. The most well-known diseases is the Wilson's disease, whose treatment consists of oral administration of chelators, i.e. chemical compounds, which are capable of binding copper ions in various proportions and eliminating them from the organism. Chelation therapy is currently the first choice after confirmation of the diagnosis. Chelation toxicity results from several factors, e.g. inhibition of copper dependent enzymes or low selectivity to metals. And precisely the selectivity of chelators is being discussed in this diploma thesis. An ideal chelator should not interact with any of the other physiological ions, that are necessary for the proper functioning of the organism. Five of the most frequently therapeutically or experimentally used substances /trientine, D-penicillamine,...
Transcriptomic analysis of cutaneous inflammatory biomarkers in a mouse model of small fiber neuropathy
Benčová, Simona ; Mladěnka, Přemysl (advisor) ; Smutný, Tomáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Simona Benčová Supervisors: Dr. Claire Demiot, Dr. Aurore Danigo Assoc. Prof. Přemysl Mladěnka, Ph.D Title of diploma thesis: Transcriptomic analysis of cutaneous inflammatory biomarkers in a mouse model of small fiber neuropathy. Peripheral neuropathy is an expanding public health problem conditioned by various diseases and associated with several adverse effects such as the occurrence of chronic pain or increased risk of pressure ulcers (PUs). The aim of this study is to explore, whether the inflammatory state of the skin is modified during peripheral neuropathy and in the course of the formation of a pressure ulcer. The transcriptomic analysis was performed with two different models of mice: PU model and uninjured model, to determine genes that differ in expression and in particular, those involved in inflammation. Small fiber neuropathy was induced in young mice by intraperitoneal injection of resiniferatoxin (50 µg/kg, i.p.) - transient receptor potential vanilloid 1 (TRPV1) agonist. PUs were induced by applying two magnetic plates on the dorsal skin. Gene expression was obtained based on RNA microarray and the results were subsequently verified by qPCR. The transcriptomic analysis of PU...
Ability of copper chelators to interact with iron and zinc
Hanuščinová, Lucia ; Mladěnka, Přemysl (advisor) ; Čonka, Patrik (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lucia Hanuščinová Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmDr., PhD. Title of diploma thesis: Ability of copper chelators to interact with iron and zinc Copper plays in the human organism a role of an element with indispensable significance, whose biological influence and effects depend on its quantity. With elevated concentrations in the human body, copper becomes toxic, resulting in pathological conditions. The most well-known diseases is the Wilson's disease, whose treatment consists of oral administration of chelators, i.e. chemical compounds, which are capable of binding copper ions in various proportions and eliminating them from the organism. Chelation therapy is currently the first choice after confirmation of the diagnosis. Chelation toxicity results from several factors, e.g. inhibition of copper dependent enzymes or low selectivity to metals. And precisely the selectivity of chelators is being discussed in this diploma thesis. An ideal chelator should not interact with any of the other physiological ions, that are necessary for the proper functioning of the organism. Five of the most frequently therapeutically or experimentally used substances /trientine, D-penicillamine,...
Iron-chelating properties of fruit extracts of various elderberries
Gorová, Barbora ; Mladěnka, Přemysl (advisor) ; Kašparová, Marie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Barbora Gorová Supervisor: Assoc Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of thesis: Iron-chelating properties of fruit extracts of various elderberries Inorganic iron is the major food source of iron in humans. It plays role in many biochemical reactions. Thus, iron metabolism disorders can lead to different diseases associated with lack of iron or iron overload. One of the possible treatment modalities of the latter represents the administration of iron chelators. Elderberry, Sambucus nigra L. (Adoxaceae), has been used in traditional medicine. The fruits of elderberry are a rich source of cyanidin-based anthocyanins as the main component. There are important differences, both in chemical and physical properties between several cultivars of elderberry. Anthocyanins might interact with metals in the gastrointestinal tract by formation of chelates. However, data on metal interactions with anthocyanins are sparse. The main aim of this study was to perform the analysis of interaction of iron with elderberry fruit extracts as a rich and cheap source of anthocyanins with cyanidin as the aglycon. In this in vitro study ten elderberry fruit exctracts were tested for iron chelating activities...
Determination of the stoichiometry of the coopper complexes with 7,8-dihydroxycoumarins
Mocová, Klára ; Mladěnka, Přemysl (advisor) ; Maixnerová, Jana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Klára Mocová, MSc. Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of Thesis: Determination of the stoichiometry of the copper complexes with 7,8-dihydroxycoumarins Copper is an important element, which is necessary for right functioning of the organism because of its presence in wide range of enzymes. However, increased level of this element can cause various health complications. Coumarins are natural or synthetic substances, which contain 1,2-benzopyrone in their chemical structure. These compounds are known, among others, by their antioxidant activity, which includes the ability to chelate metals and hence form complexes with them. The stoichiometry of the complex is one of the important characteristics of metal complexes. The aim of this in vitro study was to assess the stoichiometry of 7,8- dihydroxycoumarins complexes with copper. We have been dealing with chelating activity of 7,8-dihydroxy-4-methylcoumarin and 7,8-dihydroxycoumarin with Cu+ and Cu2+ ions. Direct UV-Vis spectrophotometry was used to measure the complex formation at four physiologically or pathophysiologically relevant pH conditions (4,5; 5,5; 6,8 a 7,5). Both tested coumarins chelated Cu2+ ions in...
Flavonoids and natural coumarins interactions with conventional medicine
Sigmundová, Tereza ; Tůmová, Lenka (advisor) ; Mladěnka, Přemysl (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Supervisor: doc. PharmDr. Lenka Tůmová, CSc. Student: Tereza Sigmundová Title of Thesis: Flavonoids and natural coumarins interactions with conventional medicine Keywords: medicinal plant, flavonoids, coumarins, interactions The aim of this diploma thesis is to give an overview of the interactions between conventional drugs and simultaneous use of flavonoids, coumarins or medicinal plants containing flavonoids and coumarins. Cited literature includes articles published since 2000 till 2018, that were collected mostly using online databases (Web of Science, Science Direct, PubMed, Google Scholar). Flavonoids can affect the metabolism of drugs through interaction with CYP450 enzymes, P-glycoprotein, ABC or SLC transporters. This type of interaction is particularly important for drugs with narrow therapeutic index such as cyclosporin, digoxin or warfarin. Furanocoumarins contained for example in grapefruit juice cause irreversible inhibition of CYP3A4 enzyme and affect the pharmacokinetics of many drugs. The major drug classes that have been reported to present pharmacodynamic interactions with flavonoids or natural coumarins are anticoagulants, cytostatics and central nervous system agents. The thesis also describes...
Assessment of the complex stoichiometry of the active dexrazoxane metabolite ADR-925 with iron and copper by the standard Job's method
Szotáková, Tereza ; Mladěnka, Přemysl (advisor) ; Jirkovský, Eduard (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Tereza Morávková Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of Thesis: Assessment of the complex stoichiometry of the active dexrazoxane metabolite ADR-925 with iron and copper by the standard Job'smethod Iron and copper are important trace elements which participate on many physiological processes in humans. Their kinetics in the organism is tightly regulated since both lack or excess of these elements are associated with pathological states. Free ions of iron and copper can catalyse reactive oxygen species (ROS) production and hence cause damage to proteins and DNA. Imbalance in these metals is linked with diabetes, cardiotoxicity, cirrhosis of the liver and neurodegenerative diseases as Alzheimer's disease or Parkinson's disease. Dexrazoxane is a drug with documented protecting effect against cardiotoxicity of anthracyclines. A former theory associated its protective effects against these cytotoxic drugs with the iron-chelating properties of its active metabolite ADR-925. The goal of this diploma thesis was to explore if ADR-925 is able to chelate Fe2+ , Fe3+ , Cu+ a Cu2+ ions at physiologically and pathophysiologically relevant pH values (4,5; 5,5; 6,8 and 7,5) and...

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