102 research outputs found
Fast and reliable HPLC method for determination of cefuroxime in human serum : application to optimization of dosing regimen in patients with lower respiratory tract infection
A rapid and inexpensive high-performance liquid chromatography method with UV detection for determination of cefuroxime (CFU) in small human serum samples was developed and validated. In this method, serum samples were spiked with an internal standard and proteins were precipitated by 0.4 M perchloric acid. Separation was carried out on an RP-18 column with a mobile phase composed of 20 mM potassium dihydrogen phosphate buffer and methanol (85 : 15; v/v), pH 4.5. In order to assess the usefulness of newly developed method in CFU dosage design, CFU concentrations in serum from 6 patients with lower respiratory tract infections ranging in age from 43 to 91 years were determined. The antibiotic was administered intravenously at a dose of 1500 mg every 8 hours for 10-14 days. Pharmacokinetic analysis and simulations were performed using Phoenix WinNonlin. Dosage optimization was based on pharmacokinetic pharmacodynamic (PK/PD) indices. The lower limit of quantification of the assay was 0.25 μg/mL and the calibration curve was linear at the concentration range from 0.25 to 300 μg/mL. The method was characterized by an excellent precision (≤ 6.4%) and accuracy (≤ 9.0%). Recoveries ranged from 92% to 96%. CFU in serum samples was stable when stored at -30OC for at least 10 days, at room temperature (+22OC) for up to 6 h, and during three freezeñthaw cycles, when stored at -30OC and thawed to room temperature. Pharmacokinetic analysis showed significant differences in pharmacokinetic parameters of CFU in the studied patients: volume of distribution was from 8.9 to 20.6 L, terminal elimination half-life from 1.3 to 5.3 h, and total body clearance from 31 to 232 mL/min. In the elderly patients studied dosage optimization was required. These results suggest that our simple and rapid HPLC method may be useful to monitor serum CFU concentrations in patients on standard dosages and to support determination of CFU dosage regimens based on the PK/PD indices
Effect of sildenafil on the activity of some antidepressant drugs and electroconvulsive shock treatment in the forced swim test in mice
Sildenafil, a potent and selective inhibitor of phosphodiesterase type 5, is used clinically to treat erectile dysfunction and pulmonary arterial hypertension. It is often taken by patients suffering from depression and receiving antidepressant drug treatment. However, its influence on the efficacy of antidepressant treatment was not sufficiently studied. Therefore, the aim of the present study was to investigate the influence of sildenafil on the anti-immobility action of several antidepressant drugs (i.e., sertraline, fluvoxamine, citalopram, maprotiline, trazodone, and agomelatine) as well as on antidepressant-like effect of electroconvulsive stimulations in the forced swim test in mice. The obtained results showed that acute sildenafil treatment enhanced the antidepressant-like activity of all of the studied drugs. The observed effects were not due to the increase in locomotor activity. The interactions between sildenafil and sertraline, maprotiline, and trazodone were pharmacodynamic in nature, as sildenafil did not affect concentrations of these drugs neither in serum nor in brain tissue. Increased concentrations of fluvoxamine, citalopram, and agomelatine in brain tissue evoked by sildenafil co-administration suggest that pharmacokinetic interactions between sildenafil and these drugs are very likely. Sildenafil injected acutely did not alter the antidepressant-like efficacy of electroconvulsive stimulations in mice, as assessed in the forced swim test. Interestingly, repeated (14 days) administration of sildenafil decreased the anti-immobility action of the electroconvulsive stimulations. In conclusion, the present study shows that sildenafil may alter the effectiveness of antidepressant treatment. Further studies are warranted to better characterize the influence of sildenafil on the activity of antidepressant drugs and electroconvulsive therapy
Effect of pterostilbene, a natural analog of resveratrol, on the activity of some antiepileptic drugs in the acute seizure tests in mice
Antidepressant-like activity of sildenafil following acute and subchronic treatment in the forced swim test in mice : effects of restraint stress and monoamine depletion
Sildenafil is a highly effective oral agent for the treatment of erectile dysfunction of multiple etiologies. Although in clinical practice sildenafil is often used in depressed patients, its influence on the pathophysiology of depression remains unclear. The aim of the present study was to evaluate the antidepressant-like activity following acute and subchronic treatment with sildenafil in naïve mice as well as in mice with reserpine- and restraint stress-induced depressive-like behavior. Since corticosterone is released in response to acute stress, we also aimed to assess the influence of sildenafil on serum corticosterone level in non-stressed and stressed animals. The antidepressant activity of sildenafil was assessed in the forced swim test. Corticosterone serum level was determined by using ELISA method, while brain and serum sildenafil level via HPLC method. Sildenafil administered acutely exerted an antidepressant-like effect. Subchronic (14 days) administration of sildenafil resulted only in a weak antidepressant-like effect when evaluated 24 h after the last dose. Acute but not subchronic sildenafil administration reversed the reserpine- and stress-induced immobility in the forced swim test. The lack of effects of sildenafil after subchronic treatment could have been related to its complete elimination from the brain within 24 h from the last injection. Interestingly, acute administration of sildenafil produced a marked increase in serum corticosterone level in both non-stressed and stressed animals. Sildenafil exerts differential effects in the forced swim test after acute and subchronic administration. Further studies on the antidepressant activity of sildenafil are required
Anti-inflammatory and antioxidant activity of 8-methoxy-1,3-dimethyl-2,6-dioxo-purin-7-yl derivatives with terminal carboxylic, ester or amide moieties in animal models
The previous studies in a series of 8-methoxy-1,3-dimethyl-2,6-dioxo-purin-7-yl derivatives revealed their analgesic properties. We extended the study with these compounds in aim to assess their impact on inflammatory process. For this purpose we used: the zymosan-induced peritonitis and the carrageenan induced edema model. Furthermore, the antioxidant activity of the investigated compounds by the FRAP assay was determined. For the most active derivatives from evaluated series their influence on plasma TNF-α level was also tested in vivo. All investigated purine-2,6-dione derivatives 1-11 decreased neutrophils count and inhibited intensity of early vascular permeability. Furthermore, all evaluated compounds reduced the volume of edema caused by subcutaneous injection of carrageenan. Derivatives 1 (with ester moiety), 3 and 4 (with carboxylic group) showed the highest activity in the zymosan-induced peritonitis. In addition, a significant inhibition of plasma TNF-α level in rats with endotoxemia was observed following intraperitoneal administration of these compounds. In turn, compounds 6 and 8-11 containing amide moiety showed the greatest anti-inflammatory (antiedematous) effect in the carrageenan-induced paw edema model. All compounds did not show significant antioxidant properties. The present studies revealed that the presented purine-2,6-dione derivatives exhibit a significant anti-inflammatory activity and this effect may result from their ability to lower TNF-α level
Effect of tadalafil on seizure threshold and activity of antiepileptic drugs in three acute seizure tests in mice
Pharmacokinetic study of tianeptine and its active metabolite MC5 in rats following different routes of administration using a novel liquid chromatography tandem mass spectrometry analytical method
Polimorfizm genu oksydoreduktazy cytochromu P450 a farmakokinetyka pantoprazolu u zdrowych ochotników
Genetycznie uwarunkowana aktywność enzymów metabolizujących
leki może mieć znaczenie dla bezpieczeństwa i skuteczności
leczenia. We wcześniejszych badaniach wykazano,
że na aktywność enzymatyczną CYP2C19 może wpływać nie
tylko polimorfizm genu kodującego ten cytochrom, lecz także
zawartość reduktazy cytochromu P450 (POR) w mikrosomach
ludzkich hepatocytów. Ludzki gen POR wykazuje dużą zmienność,
a allel POR*28 jest związany ze zwiększoną aktywnością
reduktazy, co w konsekwencji może prowadzić do zwiększonej
aktywności układu CYP P450, w tym enzymu CYP2C19.
Celem badania było określenie związku pomiędzy polimorfizmem
genu POR a parametrami farmakokinetycznymi pantoprazolu,
substratu CYP2C19 w grupie zdrowych ochotników.
W analizie uwzględniono także warianty genu CYP2C19. U 30 osób, u których wykonano badanie
pod kątem występowania jednonukleotydowych
polimorfizmów:
rs4244285 (681G>A, CYP2C19*2), rs12248560 (-806C>T, CYP2C19*17)
oraz rs1057868 (31696C>T, POR*28). Stężenia pantoprazolu w osoczu
zmierzono metodą wysokosprawnej chromatografii cieczowej
w ciągu 8 godz. od przyjęcia pojedynczej doustnej dawki
leku (40 mg). Nie stwierdzono istotnych różnic w stężeniu pantoprazolu
pomiędzy osobami o różnych genotypach POR (*1/*1,
*1/*28 i *28/*28). Analiza wieloczynnikowa wykazała, że genotyp
CYP2C19 istotnie wpływał na wartość wszystkich analizowanych
parametrów farmakokinetycznych (p < 0.05), podczas
gdy genotyp POR nie był istotnie związany z żadnym z nich. Wyniki badania wskazują, że polimorfizm genu POR
nie wpływa istotnie na farmakokinetykę pantoprazolu.It has recently been demonstrated that CYP2C19
activity may be influenced not only by CYP2C19 polymorphism,
but also cytochrome P450 oxidoreductase (POR) protein abundance
in human liver microsomes. The human POR gene is highly
polymorphic and a common POR*28 allele is associated with
increased POR activity, which may result in increased CYP P450
activity (including CYP2C19).
The aim of the current study was to evaluate the association
between POR and CYP2C19 polymorphisms and CYP2C19 substrate
pharmacokinetics, i.e. pantoprazole, in Polish Caucasian
healthy volunteers. The study enrolled 30 subjects, genotyped
for rs4244285 (681G>A, CYP2C19*2), rs12248560 (-806C>T,
CYP2C19*17) and rs1057868 (31696C>T, POR*28). Pantoprazole
concentration in plasma was determined by validated highperformance
liquid-chromatography method 1 h, 2 h, 3 h, 4 h, 6 h
and 8 h after a single oral 40 mg dose of the drug. No significant differences in the drug concentrations
between POR*1/*1, POR*1/*28 and POR*28/*28 carriers were
observed. Multivariate analysis revealed that the CYP2C19 genotype
significantly influenced all the investigated pharmacokinetic
parameters (p < 0.05), while the POR genotype was not
associated with any of the parameters. The results of the current study suggest that POR
polymorphism does not significantly influence pantoprazole
pharmacokinetics
Pan-Phosphodiesterase Inhibitors Attenuate TGF-β-Induced Pro-Fibrotic Phenotype in Alveolar Epithelial Type II Cells by Downregulating Smad-2 Phosphorylation
Airway remodeling is a pathological process that accompanies many chronic lung diseases. One of the important players in this process are epithelial cells, which under the influence of pro-inflammatory and pro-fibrotic factors present in the airway niche, actively participate in the remodeling process by increasing extracellular matrix secretion, acquiring migration properties, and overproducing pro-fibrotic transducers. Here, we investigated the effect of three new 8-arylalkylamino- and 8-alkoxy-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl-N-(5-(tert-butyl)-2-hydroxyphenyl)butanamides (1, 2, and 3), representing prominent pan-phosphodiesterase (pan-PDE) inhibitors on transforming growth factor type β (TGF-β)-induced alveolar epithelial type II cells (A549 cell line) of a pro-fibrotic phenotype. Our results demonstrate for the first time the strong activity of pan-PDE inhibitors in the prevention of TGF-β-induced mesenchymal markers’ expression and A549 cells’ migration. We also showed an increased p-CREB and decreased p-Smad-2 phosphorylation in TGF-β-induced A549 cells treated with 1, 2, and 3 derivatives, thereby confirming a pan-PDE inhibitor mesenchymal phenotype reducing effect in alveolar epithelial type II cells via suppression of the canonical Smad signaling pathway. Our observations confirmed that PDE inhibitors, and especially those active against various isoforms involved in the airway remodeling, constitute an interesting group of compounds modulating the pro-fibrotic response of epithelial cells
Traxoprodil, a selective antagonist of the NR2B subunit of the NMDA receptor, potentiates the antidepressant-like effects of certain antidepressant drugs in the forced swim test in mice
One of the newest substances, whose antidepressant activity was shown is traxoprodil, which is a selective antagonist of the NR2B subunit of the NMDA receptor. The main goal of the present study was to evaluate the effect of traxoprodil on animals’ behavior using the forced swim test (FST), as well as the effect of traxoprodil (10 mg/kg) on the activity of antidepressants, such as imipramine (15 mg/kg), fluoxetine (5 mg/kg), escitalopram (2 mg/kg) and reboxetine (2.5 mg/kg). Serotonergic lesion and experiment using the selective agonists of serotonin receptors 5-HT(1A) and 5-HT(2) was conducted to evaluate the role of the serotonergic system in the antidepressant action of traxoprodil. Brain concentrations of tested agents were determined using HPLC. The results showed that traxoprodil at a dose of 20 and 40 mg/kg exhibited antidepressant activity in the FST and it was not related to changes in animals’ locomotor activity. Co-administration of traxoprodil with imipramine, fluoxetine or escitalopram, each in subtherapeutic doses, significantly affected the animals’ behavior in the FST and, what is important, these changes were not due to the severity of locomotor activity. The observed effect of traxoprodil is only partially associated with serotonergic system and is independent of the effect on the 5-HT(1A) and 5-HT(2) serotonin receptors. The results of an attempt to assess the nature of the interaction between traxoprodil and the tested drugs show that in the case of joint administration of traxoprodil and fluoxetine, imipramine or escitalopram, there were interactions in the pharmacokinetic phase
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