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Study of inhibition activity of new antitumor drugs against chosen isoforms of cytochromes P450
Kroulíková, Pavla ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Mgr. Pavla Kroulíková Supervisor: RNDr. Jakub Hofman, Ph.D. Title of Thesis: Study of inhibitory activity of new anticancer drugs toward selected isoforms of cytochromes P450 Cytochromes P450 are important biotransformation enzymes that affect pharmacokinetic behavior of many clinically used drugs and are the cause of many major drug interactions. They may have a role in overcoming multidrug resistance of cancer cells because many cytostatic drugs are deactivated by them. Aim of this thesis was in vitro study of inhibition of selected isoforms (CYP3A4, CYP3A5, CYP1A2, CYP2C8, CYP2D6, CYP2C9, CYP2C19 and CYP2B6) by substances from the group of tyrosine kinase inhibitors - alectinib, brivanib, osimertinib and selumetinib. We used commercially available Vividâ CYP Screening kits for the study. In these kits, human cytochromes P450 are recombinantly inserted into insect microsomes. The advantage of this method is that during the experiment no other reaction catalyzed by a different enzyme occurs simultaneously. The principle of this method is conversion of fluorogenic substrate into fluorescent product by CYP450. We determined the inhibition by measuring fluorescence in the 15th minute from start...
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The impact of positive inotropic and antiarrhythmic drugs on cardiovascular system
Kočková, Radka ; Linhart, Aleš (advisor) ; Janoušek, Jan (referee) ; Štengl, Milan (referee)
Heart rate changes mediate the embryotoxic effect of antiarrhythmic drugs in the chick embryo A significant increase in cardiovascular medication use during pregnancy has occurred in recent years but only limited evidence on its safety profile is available. We hypothesized that drug-induced bradycardia is the leading mechanism of developmental toxicity. We tested metoprolol, carvedilol, or ivabradine for embryotoxicity and their acute effect on chick embryonic model. We used video microscopy and ultrasound biomicroscopy. Significant dose-dependent mortality was achieved in embryos injected with carvedilol and ivabradine. In ED4 embryos, metoprolol, carvedilol and ivabradine reduced the heart rate by 33%, 27%, and 55%, respectively, compared to controls (6%). In ED8 embryos this effect was more pronounced with a heart rate reduction by 71%, 54%, 53%, respectively (controls 36%). Cardiac output decreased in all tested groups but only proved significant in the metoprolol group in ED8 embryos. The number of -adrenergic receptors showed a downward tendency during embryonic development but a negative chronotropic effect of tested drugs was increasingly pronounced with embryonic maturity. This effect was associated with reduced cardiac output in chick embryos, probably leading to premature death....
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Study of inhibition activity of new antitumor drugs against chosen isoforms of cytochromes P450
Kroulíková, Pavla ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Mgr. Pavla Kroulíková Supervisor: RNDr. Jakub Hofman, Ph.D. Title of Thesis: Study of inhibitory activity of new anticancer drugs toward selected isoforms of cytochromes P450 Cytochromes P450 are important biotransformation enzymes that affect pharmacokinetic behavior of many clinically used drugs and are the cause of many major drug interactions. They may have a role in overcoming multidrug resistance of cancer cells because many cytostatic drugs are deactivated by them. Aim of this thesis was in vitro study of inhibition of selected isoforms (CYP3A4, CYP3A5, CYP1A2, CYP2C8, CYP2D6, CYP2C9, CYP2C19 and CYP2B6) by substances from the group of tyrosine kinase inhibitors - alectinib, brivanib, osimertinib and selumetinib. We used commercially available Vividâ CYP Screening kits for the study. In these kits, human cytochromes P450 are recombinantly inserted into insect microsomes. The advantage of this method is that during the experiment no other reaction catalyzed by a different enzyme occurs simultaneously. The principle of this method is conversion of fluorogenic substrate into fluorescent product by CYP450. We determined the inhibition by measuring fluorescence in the 15th minute from start...
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The impact of positive inotropic and antiarrhythmic drugs on cardiovascular system
Kočková, Radka ; Linhart, Aleš (advisor) ; Janoušek, Jan (referee) ; Štengl, Milan (referee)
Heart rate changes mediate the embryotoxic effect of antiarrhythmic drugs in the chick embryo A significant increase in cardiovascular medication use during pregnancy has occurred in recent years but only limited evidence on its safety profile is available. We hypothesized that drug-induced bradycardia is the leading mechanism of developmental toxicity. We tested metoprolol, carvedilol, or ivabradine for embryotoxicity and their acute effect on chick embryonic model. We used video microscopy and ultrasound biomicroscopy. Significant dose-dependent mortality was achieved in embryos injected with carvedilol and ivabradine. In ED4 embryos, metoprolol, carvedilol and ivabradine reduced the heart rate by 33%, 27%, and 55%, respectively, compared to controls (6%). In ED8 embryos this effect was more pronounced with a heart rate reduction by 71%, 54%, 53%, respectively (controls 36%). Cardiac output decreased in all tested groups but only proved significant in the metoprolol group in ED8 embryos. The number of -adrenergic receptors showed a downward tendency during embryonic development but a negative chronotropic effect of tested drugs was increasingly pronounced with embryonic maturity. This effect was associated with reduced cardiac output in chick embryos, probably leading to premature death....
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