|
|
Interaction of 7,8-dihydroxyflavone with physiological metals
Streďanská, Aneta ; Mladěnka, Přemysl (advisor) ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Aneta Streďanská Supervisor: prof. Přemysl Mladěnka, Pharm.D., PhD. Consultant: Zuzana Lomozová, Pharm.D., PhD. Title of thesis: Interactions of 7,8-dihydroxyflavone with physiological metals 7,8-dihydroxyflavone belongs to the phenolic substances collectively referred to as flavonoids. Flavonoids are bioactive components abundantly distributed in the daily diet with the ability to modulate health and disease through miscellaneous mechanisms including their antioxidant activity. However, they can also exhibit prooxidative effects under certain conditions. Due to this fact, which is related to individual factors, i.e. presence of various substitutions on the flavonoid come, it is therefore essential to understand the redox behavior based on the relationship between structure and effect and to understand their physiological, pharmacological and thus also potential toxic properties. The interaction with physiological metals is determined by the structure of the molecule through the dihydroxy moiety in positions 7 and 8. These mentioned metals are essential for many biochemical processes in biological systems. Their homeostasis is strictly regulated in the human body and disruption of this...
|
|
|
The impact of small phenolic metabolites of flavonoids (propionic acids) on the iron-catalysed Fenton reaction
Spiller, Sára ; Lomozová, Zuzana (advisor) ; Karlíčková, Jana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacognosis and Pharmaceutical Botany Candidate: Sára Spiller Supervisor: PharmDr. Zuzana Lomozová, Ph.D. Title of diploma thesis: The impact of small phenolic metabolites of flavonoids (propionic acids) on the iron-catalysed Fenton reaction Keywords: iron, flavonoid, Fenton reaction, antioxidant, pro-oxidant Iron is an essential element, necessary for the proper functioning of the human body. It is involved in many cellular processes where it acts as a cofactor. It is physiologically very important, especially for its ability to readily accept and deliver electrons. Its amount in the body is strictly regulated because in excess of the free metal, harmful radical reactions and the development of oxidative stress could result. Oxidative stress is responsible for many pathological processes. Flavonoids are natural polyphenolic substances that are found in many plants. Their consumption is associated with beneficial effects on human health, including antioxidant, anti-inflammatory, and cardioprotective properties. Despite their beneficial effects, they may, under certain circumstances, possess pro-oxidant effects related to their redox properties. During the metabolism of flavonoids, the gut microbiome degrades them to simple...
|
|
|
Vliv přídavku quercetinu na výskyt kokcidií u králíků
Dvořáčková, Nikola
This thesis investigated the effect of the flavonoid quercetin on the coccidiosis oocyst counts in rabbits. At the same time, it also investigated the impact on weight, daily gains, feed conversation ratio, daily and total consumption, and biochemical blood parameters. The experiment lasted a total of 116 days. Two groups of six piece weaned rabbits each of the Japanese rabbit breed were created. The age of the rabbits was 35–149 days in the experimental group and 31–145 days in the control group. The average weight of rabbits at the beginning of the experiment was 267 g, and at the end, it was 2288 g. A special feed mixture containing 1.9% quercetin was prepa-red for the experimental group. The mixture was added in the amounts of 1, 2, and 4 g per day, depending on their equal weight. The addition of 0.01 – 0.04 g/rabbit/day of the flavonoid quercetin did not have a negative effect on the health status, performance parameters, and biochemical para-meters of the blood. The experimental group had a lower average number of oocysts (EPG) than the control group (quercetin = 328, control = 640). There was a statisti-cally significant effect of quercetin on the number of coccidia oocysts (P < 0.05), pro-bably through its antioxidant effect, supporting immune reactions, and thereby main-taining a healthy intestinal environment. Quercetin can be a potential substance for the prevention of coccidiosis.
|
|
|
Study of the mechanisms of action of phenolic compounds on vascular smooth muscle
Alves Dias, Patrícia Alexandra ; Mladěnka, Přemysl (advisor) ; Kyselovič, Ján (referee) ; Štengl, Milan (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Training Workplace Department of Pharmacology and Toxicology Doctoral Degree Program Pharmacology and Toxicology Candidate Patrícia Alexandra Alves Dias, M.Sc. Supervisor prof. Přemysl Mladěnka, Pharm.D., Ph.D. Advisor assoc. prof. Jana Pourová, Pharm.D., Ph.D. Title of Doctoral Thesis Study of the mechanisms of action of phenolic compounds on the vascular smooth muscle Cardiovascular diseases including hypertension, coronary artery disease, peripheral artery disease, and cerebrovascular disease remain the leading cause of death worldwide. In addition, discouraging estimations have suggested a future increase in the number of cardiovascular patients. Thus, novel treatment modalities are clearly needed to prevent or reverse these epidemic trends. Phenolic compounds contain one or more hydroxyl groups bound to a benzene ring. This class of chemicals includes: a) natural compounds (e.g., dietary polyphenols and small phenolic metabolites) referred to as nutraceuticals due to their claimed health-promoting effects and b) synthetic compounds (e.g., bisphenols) which, on the contrary, have been suggested to negatively affect human health. Even if there are claims that polyphenol-rich diet is associated with cardioprotective effects, important...
|
|
|
Effects of isoflavonoids and their metabolites on vascular smooth muscles in vitro and in vivo
Migkos, Thomas ; Mladěnka, Přemysl (advisor) ; Studenik, Christian (referee) ; Trejtnar, František (referee)
Charles University Faculty of Pharmacy in Hradec Kralove Department of Pharmacology & Toxicology Candidate: Thomas Migkos, M.Sc. Supervisor: Prof. Přemysl Mladěnka, Pharm.D, Ph.D. Consultant: Assoc. Prof. Jana Pourová, Pharm.D, Ph.D. Title of dissertation thesis: Effects of isoflavonoids and their metabolites on vascular smooth muscles in vitro and in vivo The dietary intake of flavonoids seems to be inversely related to cardiovascular mortality, in particular on coronary artery disease. The consumption of isoflavonoids, one class of flavonoids, has been increasing in the general population, especially due to the use of food supplements and a variety of isoflavonoid-rich foods. Although their bioavailability is low, they undergo extensive gastrointestinal metabolism by human bacteria, leading to smaller metabolites with a much higher degree of bioavailability. However, detailed studies on the impact of individual pure isoflavonoids on vascular system were mostly missing and much less was known for the effect of their colonic metabolites in this field. In the present study sixteen isoflavonoids, four metabolites and the racemic mixture of one of them were initially screened ex vivo for their vasorelaxant properties on rat aortas. The most potent of them, biochanin A, glycitein, O-desmethylangolensin...
|
|
|
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...
|
|
|
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...
|
|
|
The influence of benzoic acids (metabolites of flavonoids) on the copper-triggered Fenton reaction and hemolysis
Harčárová, Patrícia ; Lomozová, Zuzana (advisor) ; Karlíčková, Jana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacognosis and Pharmaceutical Botany Student: Patrícia Harčárová Supervisor: Zuzana Lomozová, MSc., Ph.D. Title of diploma thesis: Effect of benzoic acids (flavonoid metabolites) on copper catalyzed Fenton reaction and hemolysis Keywords: flavonoids, benzoic acids, copper, Fenton reaction, hemolysis Copper is a biogenic trace element that is present in several enzymes and proteins in the human body. The ability of copper to change its oxidation state is essential for its biological functions and enables enzymatic redox reactions in the organism. Homeostasis of copper is strictly regulated in the human body as its disruption can lead to the toxic effects of copper. Flavonoids are secondary plant metabolites that are a common part of our diet and their consumption has positive effects on our bodies. However, under certain conditions, they can also have a pro-oxidative effect, which is related to their ability to reduce transition metal ions. Flavonoids are massively metabolized in the human body before reaching systemic circulation into small phenolic substances including benzoic acids. Seven benzoic acid derivatives were tested as part of this thesis. Their influence on the production of hydroxyl radicals arising during the...
|
|
|
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...
|
|
|
Alkaloid and flavonoid content in Fontinalis antipyretica Hedw.
Ptáčníková, Lucie ; Martin, Jan (advisor) ; Tůmová, Lenka (referee)
Lucie Ptáčníková, The volume of alkaloids and flavonoids in Fontinalis antipyretica, Thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, thesis tutor: PharmDr. Jan Martin, PhD., Hradec Králové, 2012, 55 pages. Thesis called "Content of alkaloids and flavonoids in Fontinalis anitpyretica" establishes alkaloids and flavonoids and identifies one substance of these alkaloids in the above-mentioned water moss. The main purpose of this thesis was to obtain samples of Fontinalis antipyretica from selected locations in the Czech Republic (Ledce, Rychnovek, Kunvald). Next purpose was to determine alkaloids and flavonoids of collected material, isolated one substance of alkaloid character and verify identity of selected alkaloid. The content of alkaloids and flavonoids was determined by using the high-performance liquid chromatography (HPLC). The results show that β - carboline alkaloid harmin was determined by consensus UV spectrum and retention time with standard. Consequently flavonoids called myricetin and hyperosid was determined. Identity of β - carboline alkaloid harmin was verified by using NMR analysis. Keywords: alkaloids - harmalol - harmin - Fontinalis antipyretica - flavonoids
|
guest ::
