Cytochromes P450 are major metabolic enzymes involved in the biotransformation of xenobiotics. The majority of xenobiotics are metabolized in the liver, in which the highest levels of cytochromes ...P450 are expressed. Flavonoids are natural compounds to which humans are exposed through everyday diet. In the previous study, selected flavonoid aglycones showed inhibition of CYP3A4 enzyme. Thus, the objective of this study was to determine if these flavonoids inhibit metabolic activity of CYP1A2, CYP2A6, CYP2C8, and CYP2D6 enzymes. For this purpose, the
-deethylation reaction of phenacetin was used for monitoring CYP1A2 enzyme activity, coumarin 7-hydroxylation for CYP2A6 enzyme activity, 6-α-hydroxylation of paclitaxel for CYP2C8 enzyme activity, and dextromethorphan
-demethylation for CYP2D6 enzyme activity. The generated metabolites were monitored by high-performance liquid chromatography coupled with diode array detection. Hesperetin, pinocembrin, chrysin, isorhamnetin, and morin inhibited CYP1A2 activity; apigenin, tangeretin, galangin, and isorhamnetin inhibited CYP2A6 activity; and chrysin, chrysin-dimethylether, and galangin inhibited CYP2C8. None of the analyzed flavonoids showed inhibition of CYP2D6. The flavonoids in this study were mainly reversible inhibitors of CYP1A2 and CYP2A6, while the inhibition of CYP2C8 was of mixed type (reversible and irreversible). The most prominent reversible inhibitor of CYP1A2 was chrysin, and this was confirmed by the docking study.
Acacetin, apigenin, chrysin, and pinocembrin are flavonoid aglycones found in foods such as parsley, honey, celery, and chamomile tea. Flavonoids can act as substrates and inhibitors of the CYP3A4 ...enzyme, a heme containing enzyme responsible for the metabolism of one third of drugs on the market. The aim of this study was to investigate the inhibitory effect of selected flavonoids on the CYP3A4 enzyme, the kinetics of inhibition, the possible covalent binding of the inhibitor to the enzyme, and whether flavonoids can act as pseudo-irreversible inhibitors. For the determination of inhibition kinetics, nifedipine oxidation was used as a marker reaction. A hemochromopyridine test was used to assess the possible covalent binding to the heme, and incubation with dialysis was used in order to assess the reversibility of the inhibition. All the tested flavonoids inhibited the CYP3A4 enzyme activity. Chrysin was the most potent inhibitor: IC50 = 2.5 ± 0.6 µM, Ki = 2.4 ± 1.0 µM, kinact = 0.07 ± 0.01 min−1, kinact/Ki = 0.03 min−1 µM−1. Chrysin caused the highest reduction of heme (94.5 ± 0.5% residual concentration). None of the tested flavonoids showed pseudo-irreversible inhibition. Although the inactivation of the CYP3A4 enzyme is caused by interaction with heme, inhibitor-heme adducts could not be trapped. These results indicate that flavonoids have the potential to inhibit the CYP3A4 enzyme and interact with other drugs and medications. However, possible food–drug interactions have to be assessed clinically.
Flavonoids, a diverse group of polyphenolic compounds found abundantly in fruits, vegetables, and beverages like tea and wine, offer a plethora of health benefits. However, they have a potential ...interaction with drug metabolism, particularly through the inhibition of the cytochrome P450 3A4 enzyme, the most versatile and abundant enzyme in the liver. CYP3A4 is responsible for metabolizing approximately 50% of clinically prescribed drugs across diverse therapeutic classes, so these interactions have raised concerns about potential adverse effects. This review delves into the scientific evidence surrounding flavonoid-mediated CYP3A4 inhibition, exploring the inhibitory potential of investigated flavonoids and future implications. Kusehnol I, chrysin, leachianone A, and sophoraflavone G showed the largest inhibitory potentials and lowest
values. While the clinical significance of flavonoid-mediated CYP3A4 inhibition in dietary contexts is generally considered low due to moderate intake and complex interactions, it poses a potential concern for individuals consuming high doses of flavonoid supplements or concurrently taking medications metabolized by CYP3A4. This can lead to increased drug exposure, potentially triggering adverse reactions or reduced efficacy.
Cytochrome P450 3A4 is the most significant enzyme in metabolism of medications. Flavonoids are common secondary plant metabolites found in fruits and vegetables. Some flavonoids can interact with ...other drugs by inhibiting cytochrome P450 enzymes. Thus, the objective of this study was to determine inhibition kinetics of cytochrome P450 3A4 by flavonoids: acacetin, apigenin, chrysin and pinocembrin. For this purpose, testosterone was used as marker substrate, and generation of the 6β-hydroxy metabolite was monitored by high performance liquid chromatography coupled with diode array detector. IC50 values, inhibition constants, and rates of inhibition were determined. IC50 values ranged between 0.6 and 11.4 µM. The strongest inhibitor was chrysin (IC50 0.6 µM, inhibition constant 0.6 µM, inhibition rate constant 0.065 min–1, inhibition efficacy 0.108 min–1 µM–1). Compared to other flavonoids analyzed, chrysin’s inhibitory effect can be attributed to the hydrophobic nonsubstituted B ring, as well as rigidity of the structure. When foods rich in chrysin are consumed, e.g. honey and propolis, chrysin can cause food-drug interactions. Further in vitro studies are needed to determine the reactive intermediate responsible for inactivation of cytochrome P450 3A4 enzyme, as well as in vivo studies to determine possible clinical significance of this inhibition.
To compare individual case safety reports (ICSR) rates and characteristics between Croatia, Serbia, Montenegro, and Bosnia and Herzegovina (B&H).
This retrospective pharmacoepidemiological study used ...the data from ICSR received by the Agency for Medicines and Medical Devices in B&H in 2011-2016. The number, characteristics, and sources of reports, suspected drugs, and patient characteristics were analyzed. The results were compared with the publicly available data from Croatia, Serbia, and Montenegro.
The number of reported adverse drug reactions per one million of inhabitants was lowest in B&H and highest in Croatia. There were significant differences in reporter characteristics, sources of reports, and the percentage of missing data in ICSR, while the Anatomical Therapeutic Chemical product classes, patient's sex, and adverse drug reaction System Organ Classes were similar.
Despite the historical and geographical vicinity of B&H and its neighboring countries, there were significant differences in indicators of pharmacovigilance development.
The aim of this study was to investigate students' knowledge, attitudes and hesitancy regarding COVID-19 vaccination.
A cross-sectional questionnaire-based survey was conducted among a total of 1282 ...medical students and 509 non-medical students at four public universities in Bosnia and Herzegovina: Tuzla, Sarajevo, Banja Luka, and Mostar.
A significantly higher rate of vaccination was observed in the group of medical students as well as a higher level of knowledge about vaccination in general and vaccines against the COVID-19 disease. Students who received the COVID-19 vaccine had a higher level of knowledge about vaccination in general and COVID-19 vaccines in particular compared to the non-vaccinated students in the medical and non-medical groups, respectively. Furthermore, vaccinated students, regardless of the course they are taking, showed generally stronger positive attitudes compared to non-vaccinated students, regarding the safety and effectiveness of the COVID-19 vaccine. Both groups of students believe that the rapid development of the vaccine is contributing to refusal or hesitancy to receive a vaccine against COVID-19. Social media/networks were the main sources of information about the COVID-19 vaccine. We did not find any contribution of social media to the reduced level of COVID-19 vaccine coverage.
Education of students about the benefits of the COVID-19 vaccine will lead to its better acceptance as well as the development of more positive attitudes towards vaccination in general, especially having in mind that students are the future population of parents, who will make decisions about vaccinating their children.
Kalcijev karbonat je kemijski spoj sastavljen od tri elementa; kalcija, ugljika i kisika, a možemo ga opisati kemijskom formulom CaCO3. U prirodnom obliku ga nalazimo u stijenama diljem svijeta, te u ...ljuskama morskih životinja, puževa, jajeta i slično. Čovjek se s kalcijevim karbonatom susreće od prapovijesti, a danas se koristi u različitim granama ljudske djelatnosti, pa tako i medicini i farmaciji.
Kalcijev karbonat danas se koristi kao lijek iz skupine lijekova s djelovanjem na probavni sustav i mijenu tvari. Koristi se u liječenju simptoma hiperaciditeta, žgaravice i nadutosti, kao i kod liječenja hiperfosfatemije u bubrežnih bolesnika. Koristi se i kao dodatak prehrani, pri čemu najviše služi za suplementaciju kalcija, kod osoba koje imaju niske razine kalcija ili se nalaze u rizičnoj skupini. Često se pronalazi i u hrani, gdje se pojavljuje u obliku prehrambenog aditiva, gdje služi kao bojilo, nutrijens, regulator kiselosti. Osim toga, kalcijev karbonat se danas naveliko upotrebljava u farmaceutskoj industriji kao pomoćna tvar, koja omogućava oblikovanje ljekovitih pripravaka.
U ovom radu obradit će se uloga kalcijevog karbonata u očuvanju ljudskog zdravlja i prevenciji bolesti, kroz prikaz njegove uporabe u različitim pripravcima vezanim za zdravlje ljudi.
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