|
|
New aspects of pregnane X receptor function and regulation
Hyršová, Lucie ; Trejtnar, František (advisor) ; Skálová, Lenka (referee) ; Vondráček, Jan (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Lucie Hyršová, MSc. First Supervisor: doc. PharmDr. František Trejtnar, CSc. Consultant: prof. PharmDr. Petr Pávek, PhD. Title of Dissertation Thesis: New aspects of pregnane X receptor function and regulation The pregnane X receptor belongs to the superfamily of nuclear receptors; it is a ligand dependent transcription factor regulating expression of its target genes. During last two decades, PXR was extensively studied as a xenosensor, i.e. the receptor, which is able to bind xenobiotics including many drugs and to regulate their metabolism by induction of the most important metabolizing enzymes of both phase I. and phase II. Induction, i.e. transcriptional stimulation of expression of the most important cytochrome P450 enzymes, by PXR ligands was described in details at many levels. Within this dissertation thesis, I am dealing with aspects of regulation via PXR, which extend the common understanding of PXR as a receptor whose exclusive function is to up-regulate drug metabolizing enzymes mediated by its agonists. Within the first, project I studied regulation of OCT1 transporter in hepatic cell models, I shown that PXR did not induce, but it rather suppressed the expression of this...
|
|
|
Synthesis of epitestosterone and 4-hydroxyestrone glucuronides using recombinant human UDP-glucuronosyltransferases.
Kašparová, Michaela ; Skálová, Lenka (advisor) ; Matoušková, Petra (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Michaela Kašparová Supervisors: Prof. RNDr. Lenka Skálová, Ph.D., Erkka Järvinen, M.Sc. (Pharm.) Title of diploma thesis: Synthesis of epitestosterone and 4-hydroxyestrone glucuronides using recombinant human UDP-glucuronosyltransferases Steroid hormones constitute an important part of the human endocrine system and are involved in a variety of physiological and pathological processes. Phase I and phase II biotransformation reactions convert these lipophilic, biologically active compounds to inactive, water-soluble metabolites that are readily excretable into bile or urine. One of the most common phase II biotransformation reactions is conjugation with glucuronic acid that is enabled by the catalytic activity of UDP-glucuronosyltransferases (UGTs). This study is focused on development and optimization of an enzymatic method for producing conjugates of glucuronic acid and two naturally occurring steroid hormones, epitestosterone and 4-hydroxyestrone. Recombinant human UGT2B7 was employed as a catalyst for the production of epitestosterone 17-glucuronide and 4-hydroxyestrone 4- glucuronide while synthesis of 4-hydroxyestrone 3-glucuronide was accomplished by UGT1A10 isoform. The synthesis reactions...
|
|
|
The effect of flubendazole and mebendazole on epithelial-mesenchymal transition.
Hochmalová, Martina ; Skálová, Lenka (advisor) ; Ambrož, Martin (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Martina Hochmalová Supervisor: prof. RNDr. Lenka Skálová, Ph.D. Consultant: RNDr. Věra Králová, Ph.D. Title of diploma thesis: The effect of flubendazole and mebendazole on the epithelial- mesenchymal transition. Epithelial-mesenchymal transition (EMT) is a process in which a non-motile epithelial cell switches to motile mesenchymal phenotype. This phenomenon is typical for multiple biological processes including cancer metastases. It could be induced by transforming growth factor-β (TGF-β) which is produced by cancer cells and which regulates its key transcription factors including SNAIL, ZEB and TWIST. EMT involves a series of defined events mediated by microtubules, including changes in cell shape and migration into the surrounding tissue. Based on these findings we suppose that the inhibition of tubulin polymerization could prevent the EMT process therefore cell migration and also cancer metastases. In our experiments, the effect of anthelminitic drugs flubendazole (FLU) and mebendazole (MBZ) on TGF-β-induced EMT in dysplastic oral keratinocytes was tested in vitro. Expression of molecules involved in EMT process was examined on microRNA and mRNA level using RT-PCR. The protein level of EMT...
|
|
|
Effect of parasite on activity of biotransformation and antioxidant enzymes in host intestine
Mládková, Zuzana ; Szotáková, Barbora (advisor) ; Skálová, Lenka (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Zuzana Mládková Supervisor: prof. Ing. Barbora Szotáková, Ph.D. Title of diploma thesis: Effect of parasite on activity of biotransformation and antioxidant enzymes in host intestine Hymenolepis diminuta, known as a rat tapeworm, is commonly used in science as a model of Cestoda for studying physiology, biochemistry and drug metabolism in tapeworms. Recently, Hymenolepis diminuta has been studied for helminth-based therapy for a potential treatment of inflammatory bowel disease. The aim of this study was to determine how H. diminuta influences the activity of detoxification enzymes of the host intestine. At first 6 male rats (Wistar breed) were infected by cysticercoids of Hymenolepis diminuta previously isolated from the beetles Tenebrio molitor (intermediate host). At the same time the physiological saline solution was administered to the control group of 6 male rats. All rats were housed for 2 months in animal quarters with 12 h light/dark cycle. Thereafter, the tapeworms were removed from their intestines. Intestinal mucosa containing metabolic active enzymes was isolated. Subsequently, the subcelullar fractions were prepared and used for in vitro experiment. The activity of enzymes was...
|
|
|
Metabolomic analysis of bile acids in various biological samples.
Hadravská, Pavlína ; Skálová, Lenka (advisor) ; Raisová Stuchlíková, Lucie (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences University of Eastern Finland in Kuopio, School of Pharmacy Department of Pharmaceutical Chemistry Candidate: Pavlína Hadravská Supervisor: prof. RNDr. Lenka Skálová, Ph.D. Consultant: prof. Seppo Auriola Title of Diploma thesis: Metabolomic analysis of bile acids in various biological samples This thesis aimed to establish a suitable qualitative and quantitative analysis of selected bile acids in mouse liver, human plasma and especially in human hair. Nine selected bile acids were analyzed (cholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, lithocholic acid, taurocholic acid, taurodeoxycholic acid, glycocholic acid and glycochenodeoxycholic acid). An identification and a quantification of the bile acids have been performed by UHPLC with two types of hybrid mass spectrometers (Quadrupole connected to Time of Flight and Quadrupole connected to Orbitrap). We tried to develop a method that allows a detection of both unconjugated bile acids and their glycine- and taurine-conjugates in biological samples. To develop and optimize this method, mouse liver and human plasma were used. Afterwards, the method was used to detect bile acids in human hair, because the bile acids could serve as...
|
|
|
The effect of flavonoids on selected biotransformation enzymes
Procházková, Eliška ; Szotáková, Barbora (advisor) ; Skálová, Lenka (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Eliška Procházková Supervisor: Prof. Ing. Barbora Szotáková, Ph.D. Title of diploma thesis: The effect of flavonoids on selected biotransformation enzymes In recent years, catechins which belong to flavonoids have been studied polyphenolic constituents of green tea. Especially their beneficial effects on the human health are mostly studied. The popularity of dietary supplements with high levels of flavonoids is growing and thus they can affect a wide range of biotransformation enzymes and also the metabolism of many drugs. The aim of this diploma thesis was to find out how the selected catechins - catechin (C), epicatechin (EC), epicatechin 3-gallate (ECG), epigallocatechin (EGC), epigallocatechin 3-gallate (EGCG) and the green tea extract - polyphenon 60 (P) influence the viability of the Caco-2 cells and the activity and expression of the selected biotransformation enzymes in these cells - cytochromes P450 (CYP) isoforms 1A1, 1A2, and 3A, aldehyde reductase (AKR1A1), aldo-keto reductase 1C (AKR1C), carbonyl reductase 1 (CBR1), UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT) and glutathione S-transferase (GST). The viability tests (NRU test and MTT test) proved that catechins (EGC,...
|
|
|
The effect of flubendazole on the efficacy of paclitaxel in brest cancer cells
Vítovcová, Barbora ; Skálová, Lenka (advisor) ; Ambrož, Martin (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Barbora Vítovcová Supervisor: prof. RNDr. Lenka Skálová, Ph.D. Title of diploma thesis: The effect of flubendazole on the efficacy of paclitaxel in breast cancer cells Flubendazole (FLU) is a common anthelmintic drug for veterinary and human use. Its molecular mechanism of action is based on binding to β-tubulin subunit of microtubules. FLU was previously identified to have antitumor activity. The aim of this study was to evaluate the effect of FLU on antiproliferative efficacy of paclitaxel (PTX) in breast cancer cells. For this study, three breast cancer cell lines were used - non-metastatic line MCF-7 and two metastatic cell lines, MDA-MB-231 and BT-474. The effects of FLU, PTX and FLU + PTX combination on viability of the cells (determined using WST-1 analysis) and on the expression of molecules involved in cell adhesion, migration and proliferation on mRNA (RT-PCR analysis) and protein levels (western blotting) were studied and compared. The activity of caspases after PTX and FLU treatment was evaluated using luminescence measurement. FLU has significant antiproliferative effect in all tested cell lines. MCF-7 and MDA-MB-231 have been shown as the most sensitive to PTX and FLU treatment....
|
|
|
Metabolomic analysis of bile acids in various biological samples.
Hadravská, Pavlína ; Skálová, Lenka (advisor) ; Raisová Stuchlíková, Lucie (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences University of Eastern Finland in Kuopio, School of Pharmacy Department of Pharmaceutical Chemistry Candidate: Pavlína Hadravská Supervisor: prof. RNDr. Lenka Skálová, Ph.D. Consultant: prof. Seppo Auriola Title of Diploma thesis: Metabolomic analysis of bile acids in various biological samples This thesis aimed to establish a suitable qualitative and quantitative analysis of selected bile acids in mouse liver, human plasma and especially in human hair. Nine selected bile acids were analyzed (cholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, lithocholic acid, taurocholic acid, taurodeoxycholic acid, glycocholic acid and glycochenodeoxycholic acid). An identification and a quantification of the bile acids have been performed by UHPLC with two types of hybrid mass spectrometers (Quadrupole connected to Time of Flight and Quadrupole connected to Orbitrap). We tried to develop a method that allows a detection of both unconjugated bile acids and their glycine- and taurine-conjugates in biological samples. To develop and optimize this method, mouse liver and human plasma were used. Afterwards, the method was used to detect bile acids in human hair, because the bile acids could serve as...
|
|
|
Effect of mebendazole on the activity of selected enzymes in tapeworm Hymenolepis diminuta
Lukačiková, Karolína ; Vokřál, Ivan (advisor) ; Skálová, Lenka (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Karolína Lukačiková Supervisor: PharmDr. Ivan Vokřál, Ph.D. Title of diploma thesis: Effect of mebendazole on the activity of selected enzymes in tapeworm Hymenolepis diminuta The resistance of parasitic helminths to anthelmintic drugs is a growing worldwide phenomenon and a concerning issue. Xenobiotic metabolizing enzymes play an important role in drug resistance development as they can lower the concentration of the anthelmintics in the parasite's body and therefore protect the parasite from the anthelmintic effect. The role of drug metabolizing enzymes in drug resistance development has been already described in the group of roundworms and flukes. Limited information is available about this topic in tapeworms. In our study we decided to test the possibility of the anthelmintic mebendazole to affect the activity of these enzymes and possibly to influence the drug resistance development in rat tapeworm (Hymenolepis diminuta). Our first goal was the isolation of adult tapeworms from the definitive host (rat, Rattus norvegicus). We used mealworm beetle (Tenebrio molitor) as an intermediate host. After the successful isolation, adult tapeworms were incubated with the mebendazole (1 and 10µM) in...
|
|
|
Sesquiterpenes in cancer therapy
Ambrož, Martin ; Skálová, Lenka (advisor) ; Hodek, Petr (referee) ; Souček, Pavel (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Mgr. Martin Ambrož Supervisor: Prof. RNDr. Lenka Skálová, Ph.D. Title of Doctoral Thesis: Sesquiterpenes in cancer therapy. Chemotherapy is an important part of treatment of cancer. Currently, the use of several anticancer drugs in combination seem to be more advantageous. This combination therapy prevents drug resistance development and make it possible to lower the doses of single drugs, which prevents the side effects in non-cancerous tissues. Large pool of potential drugs for combination therapy can be found among natural compounds, for example among sesquiterpenes. Our project was designed to evaluate the effect of Myrica rubra essential oil (MEO) and selected sesquiterpenes in combination cancer therapy. We focused on the potential ability of MEO and sesquiterpenes to increase the antiproliferative efficacy of classical cytostatics (doxorubicin, oxaliplatin, 5-fluorouracil). In addition, we also studied the possible interaction of sesquiterpenes with other drugs in combination therapy, which could be caused by sesquiterpene-mediated modulation of drug-metabolizing enzymes. For these purposes, a panel of various cell lines (both cancerous and non-cancerous) and primary culture of hepatocytes...
|
guest ::
RSS feed.