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In vitro and ex vivo study of drug-drug interactions of antivirals on intestinal membrane transporters
Halodová, Veronika ; Červený, Lukáš (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Veronika Halodová Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: In vitro and ex vivo study of drug-drug interactions of antivirals on intestinal membrane transporters Tenofovir (TFV) is the first-line agent in the treatment of hepatitis B virus (HBV) infection for patients aged over 12 years and one of the first-line choices for the combination antiretroviral therapy (cART) of infections caused by human immunodeficiency virus (HIV). Two commercially available prodrugs have been developed for oral administration of TFV, tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide fumarate (TAF). These prodrugs increase TFV membrane permeability and oral bioavailability. One of the factors that can affect the bioavailability of orally administrated drugs is active transport mediated by efflux transporters, mainly by P-glycoprotein (ABCB1, P-gp) and Breast cancer resistance protein (ABCG2, BCRP). It has been already proved that TDF and TAF are substrates of both of these transporters. The goal of this diploma thesis was to use in vitro and ex vivo models of intestinal barrier to assess the impact of the efflux transporters on TDF and TAF transport in the intestine and on their...
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In vitro study of drug-drug interactions of HIV protease inhibitor darunavir on efflux ABC transporters
Bezděková, Dominika ; Červený, Lukáš (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Dominika Bezděková Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: IN VITRO STUDY OF DRUG-DRUG INTERACTIONS OF HIV PROTEASE INHIBITOR DARUNAVIR ON EFFLUX ABC TRANSPORTERS Abstract: Darunavir is a drug used in the therapy of HIV belonging to the group of protease inhibitors. These protease inhibitors are used as a part of the combination antiretroviral therapy. For the increase of bioavailability, darunavir is always used in combination with ritonavir or cobicistat. As the CYP3A4 and ABCB1 (P-glycoprotein) transporter substrate, darunavir is a drug with a high potential to drug interactions. Considering the amount of adverse effects that can be caused by darunavir, it is necessary to know these drug interactions for the safety of therapy. Inhibition of the intestinal ABCB1 by the co-administrated drugs could also lead to the increased bioavailability of darunavir and to reduction of frequency of administration leading to a cheaper therapy. This thesis studies the drug-drug interactions of darunavir with in vitro methods using two cell lines - MDCKII and Caco-2 cells. The results from the transport of darunavir across the MDCKII cell monolayer indicates that darunavir is a ABCB1...
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The study of possible use of sertraline against gastrointestinal nematodes
Vodvárková, Nikola ; Skálová, Lenka (advisor) ; Vokřál, Ivan (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Nikola Vodvárková Supervisor: prof. RNDr. Lenka Skálová, Ph.D. Title of diploma thesis: The study of possible use of sertraline against gastrointestinal nematodes Haemonchus contortus is a widespread parasitic nematode infecting the gastrointestinal tract of many small ruminants that causes enormous damage to animal production every year. It is responsible for a disease in its host called Haemonchosis the main characteristic of which is anaemia caused by severe blood loss. This is responsible for the reduced productivity of the animal, and in some cases results in the death of the host. A relatively limited range of anthelmintic drugs is used for the treatment of Haemonchosis with new substances rarely being added to the list of treatments. Due to the massive use of the same anthelmintic drugs and the parasites adaptability, extensive resistance is pervasive with current treatments being no longer effective. For this reason it has become necessary to look for new effective drugs that have a different mechanism of action (MOA). One possibility is to test the anthelmintic efficacy of common drugs from other therapeutic groups. In this work, the potential anthelmintic effect, metabolism and toxicity...
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Comparison of novel amphiphilic anionic phthalocyanine photosensitizers with their hydrophilic analogues
Hasoňová, Kateřina ; Macháček, Miloslav (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Kateřina Hasoňová Supervisor: RNDr. Miloslav Macháček, Ph.D. Title of diploma thesis: Comparison of new amphiphilic anionic photosensitizers based on phthalocyanines with their hydrophilic analogues. Currently, one of the most common causes of death in our population is cancer. There are a number of treatment modalities how to treat tumours, but none of them is ideal, and a large number of people are still dying of cancer. For this reason, intensive research and studies are ongoing, focusing on cancer treatment options. In recent years, photodynamic therapy has been increasingly used to treat both cancerous and non-malignant diseases. It is a modern method that has minimal side effects, is highly selective and minimally invasive. Its principle is a photochemical reaction, which proceeds when a combination of three basic components occurs - light, oxygen and photosensitizer. Separately, these components are nontoxic, but when the photosensitizer is exposed to oxygen, toxic reactive oxygen species are produced, whose subsequently cause destruction of the tumour tissue. A photosensitizer is a compound that is able to absorb radiation of a certain wavelength and then convert it into energy, which...
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Metabolism of monepantel in parazites and their hosts
Valát, Martin ; Skálová, Lenka (advisor) ; Vokřál, Ivan (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Martin Valát Supervisor: prof. RNDr. Lenka Skálová, Ph.D. Title of diploma thesis: Metabolism of monepantel in parazites and their hosts Monepantel (MOP) belongs to a new class of anthelmintic drugs - amino-acetonitrile derivatives. They differ from the commonly used broad-spectrum drugs (makrocyclic lactones, benzimidazoles and imidazothiazoles) in chemical structure and mechanism of action. Because of frequent use of these classes the resistance in many pathogenic parasites was developed. The aim of this study was identification and comparison of phase I and II metabolites of MOP biotransformation in parasites (Haemonchus contortus - sensitive strain ISE and multi-resistant strain WR) and in their hosts - sheep (Ovis aries) through in vivo and ex vivo study. Ultra-high performance liquid chromatography with tandem mass spectrometry technique (UHPLC-MS/MS) was used for identification of MOP metabolites. In sheep, 13 metabolites of phase I and II biotransformation of MOP were detected in in vivo study, 7 of them have not been described previously. In parazites ex vivo, only 4 metabolites of phase I MOP biotransformation were found. Following biotransformation reactions of MOP were...
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Changes of internal organs after percutaneous exposure to sulfur mustard
Šulová, Veronika ; Červený, Lukáš (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Veronika Šulová Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. External supervisor: pplk. doc. MUDr. Jaroslav Pejchal, Ph.D. et Ph.D. Title of diploma thesis: Changes of internal organs after percutaneous exposure to sulfur mustard Sulfur mustard is a chemical warfare agent belonging to the group of blistering agents. The theoretical section of the thesis is mainly focused on the description of acute toxic effects, the mechanism of action, and deals with the current possibilities of poisoning therapy. The experimental section is focused on monitoring the effect of sulfur mustard poisoning in the liver, lung, and kidney of female C57BL/6J mice after the percutaneous administration. This work aimed to evaluate markers of oxidative stress and histopathological changes of the selected organs at 3, 5, and 7 days after the poisoning. Ferric reducing antioxidant power (FRAP) and thiobarbituric acid reactive substances (TBARS) methods were used to determine markers of oxidative stress. Histopathological changes were evaluated microscopically using the hematoxylin-eosin staining method. The airness of the lung parenchyma was also assessed by computer image analysis. First, the LD50 of sulfur mustard was...
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In vitro cultivation of tapeworm Hymenolepis diminuta - 2
Jandura, Dominik ; Vokřál, Ivan (advisor) ; Raisová Stuchlíková, Lucie (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Dominik Jandura Supervisor: PharmDr. Ivan Vokřál, Ph.D. Title of diploma thesis: In vitro cultivation of tapeworm Hymenolepis diminuta - 2 Aim of this diploma thesis was to obtain cycticercoids of the rat tapeworm (Hymenolepis diminuta), excyst them and find out the conditions for the maximal in vitro incubation period. As the intermediate host mealworm beetle (Tenebrio molitor) infected by the rat feces containing tapeworm eggs was used. Excystment was done using L-cystein and sodium tauroglycocholate. Excysted larvae were cultured in vitro (37 řC, 5 % CO2) in RPMI 1640 medium enriched with other substances chosen according previously published methods. Mainly sheep, mouse or rat liver extracts eventually in combination with yeast extract and sheep bile were used. The effect of tested substances on the cultivation was evaluated by measuring of the tapeworm's growth. The best effect on the grow of the tapeworms was observed using medium containing serum, yeast extract and sheep liver extract where tapeworms achieved length of 1561 µm after 16 days of incubation. The further growth was limited by appearance of pathologic formations.
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In vitro and ex vivo study of drug-drug interactions of antiretrovirals on intestinal ATP-binding drug transporters
Jahodová, Michaela ; Červený, Lukáš (advisor) ; Vokřál, Ivan (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Bc. Michaela Jahodová Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: In vitro and ex vivo study of drug-drug interactions of antiretrovirals on intestinal ATP-binding drug transporters The absorption of orally administered drugs takes place especially in the intestine, where it can affect by the activity of drug's ABC transporters located on the apical membrane of the intestinal epithelium. Study of drug interactions in intestinal ABC transporters is essential to ensure effective and safe pharmacotherapy. Testing of bi- directional transport on Caco-2 cells is generally the preferred method for in vitro evaluation of substrates and inhibitors of ABC transporters. Drawbacks of the Caco-2 model increase the need and necessity to introduce new models. A great potential is the involvement of ex vivo methodologies in the human or rat intestine. The aim of the work was to introduce an in vitro methodology using the Caco-2 cell monolayer and the ex vivo methodology of precision-cut rat intestinal slices. By the bi-directional transport method, we analyzed drug interactions of the model substrate P-gp and BCRP Rhodamine 123 (RHD123) and clinically-used tenofovir...
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Study of drug-drug interactions of antiviral drugs on intestinal transporters
Záboj, Zdeněk ; Červený, Lukáš (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Zdeněk Záboj Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Study of drugs interactions of antiviral drugs with intestinal transporters Sofosbuvir is an antiviral agent widely used in the treatment of chronic hepatitis C. This orally administered prodrug is a designed substrate of ATP-binding (ABC) efflux transporters, P- glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2). ABCB1 and ABCG2 are important determinants of intestinal absorption and are the site of significant pharmacokinetic drug interactions, leading to changes in drug exposure. Pharmacokinetic drug interactions may be undesirable (increasing the toxicity of the treatment) or desirable (allowing dose reduction). Because sofosbuvir is often administered in combination regimens with other anti(retro)virotics, the aim of this thesis was to study the ability to enhance intestinal absorption of sofosbuvir. To study the pharmacokinetic drug interactions on ABCB1 and ABCG2, a widely established in vitro bi-directional transport method through a polarized monolayer formed by the Caco-2 cell line derived from colorectal cancer has been used. We analyzed the drug interactions of sofosbuvir on these efflux...
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