Genotype and allele frequency of CYP2C19*17 in a healthy Iranian population

Background: Cytochrome P450 2C19 (CYP2C19) is important in metabolism of wide range of drugs. CYP2C19*17 is a novel variant allele which increases gene transcription and therefore results in ultra-rapid metabolizer phenotype (URM). Distribution of this variant allele has not been well studied worldwide. The aim of present study was to investigate allele and genotype frequencies of CYP2C19*17 in a healthy Iranian population and compare them with other ethnic groups. Methods: One hundred eighty healthy unrelated Iranian volunteer took part in this study and were genotyped for CYP2C19 *2, *3, *17 (-3402) by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and CYP2C19*17 (-806) by a nested-PCR assays. The distribution of CYP2C19*17 polymorphism in Iranian population was then compared with other ethnic groups. Results: The CYP2C19*17 allele frequency was 21.6 in Iranian population. Among studied subjects 5.5 were homozygous for CYP2C19*17 and phenotyped as ultra-rapid metabolizers; 28.8 were genotyped as CYP2C19*1*17 (extensive metabolizers) and 3.3 as CYP2C19*2*17 (intermediate metabolizers). Conclusion: The CYP2C19*17 genetic distribution in Iranian population is similar to Middle East or European countries. The high frequency of CYP2C19*17 in Iranian population highlights the importance of this new variant allele in metabolism of CYP2C19 substrates. Thus, future association studies are required to reveal clinical consequence of this genetic polymorphism in carrier individuals

DETECTION AND QUANTIFICATION OF CIMICOXIB, A NOVEL COX-2 INHIBITOR, IN CANINE PLASMA BY HPLC WITH SPECTROFLUORIMETRIC DETECTION: DEVELOPMENT AND VALIDATION OF A NEW METHODOLOGY

Cimicoxib (CX) is a selective COX-2 inhibitor recently launched on the veterinary market. No analytical method to detect CX in biological samples has been published to date. The chromatographic separation was performed with a Kinetex C18 analytical column (100 x 4.6 mm, 2.6 μm particle size) at 25° C. The mobile phase consisted of acetonitrile:buffer (10 mM AcONH4, pH 4.5) (35:65 v/v) at a flow rate of 1 mL/min. Excitation and emission wavelengths were 268 and 430 nm, respectively. The extraction used 500 μL of plasma added to 100 μL of IS (5 μg/mL) and 100 μL of 10% CF3COOH, extracted with 600 μL of C2H2:Et2O (3:7, v/v). The organic phase was evaporated and reconstituted with 200 μL of mobile phase. The CX recovery ranged from 74.5% to 82.6%. The limit of quantification was 25 ng mL−1. The chromatographic runs were specific with no interfering peaks at the retention times of the analytes, as confirmed by HPLC–mass spectrometry experiments. The other validation parameters were in agreement with the international guidelines. The method was successfully tested on two dogs treated at two dose rates. It facilitated tracking of the plasma concentration for 24 h and calculation of the main pharmacokinetic parameters. In conclusion, this method (extraction, separation and applied techniques) is simple, effective and specific. This is the first time that a method for the quantification of CX in plasma has been reported. This technique may have applications for further pharmacokinetic studies

PHARMACOKINETICS OF MIRTAZAPINE AND ITS MAIN METABOLITES AFTER SINGLE ORAL ADMINISTRATION IN FASTING/FED HORSES

Mirtazapine (MRZ) is a human antidepressant drug that is metabolized, predominantly by the cytochrome P450 enzyme system, to 8-OH mirtazapine (8-OH MRZ) and dimetilmirtazapine (DMR) metabolites. In veterinary medicine, this drug is currently administered to cats and dogs with anorexia, although it could also have applications as an antidepressant, antiemetic, and analgesic agent in these species. The aim of this study was to assess the pharmacokinetics of MRZ and its metabolites DMR and 8-OH MRZ in horses. Six healthy female horses were administered MRZ (2 mg/kg) in fasting and fed states according to a balanced crossover study design. Plasma MRZ and metabolite concentrations were evaluated by high-performance liquid chromatography fluorescence detection method. Pharmacokinetic profiles of MRZ and DMR were similar (detected from 0.5 up to 34 and 48 hours, respectively), with an MRZ AUC0-N/DMR AUC0-N ratio range varying between 1.1 and 1.7. Surprisingly, 8-OH MRZ was undetected. Most of the pharmacokinetic parameters were not altered by food, with the exception of the time required to reach maximum concentration; this showed a statistical increase in subjects in the fasting state as compared with the fed state. However, because MRZ is an active substance intended for long-term administration, the slight increase of the time required to reach maximum concentration is not considered to be of any clinical consequence. In conclusion, the pharmacokinetic parameters demonstrated in this study suggest that MRZ is suitable for oral administration in the horse. However, further investigations are required to evaluate both its safety and effectiveness in this animal species

Dose concentration and spatial memory and brain mitochondrial function association after 3,4-methylenedioxymethamphetamine (MDMA) administration in rats

MDMA-induced impairments of memory performance have been reported in different human and animal studies. However, the correlation between spatial memory impairment, brain mitochondrial function, and concentrations of MDMA and its metabolites has not yet been investigated despite it being needed for comparison with human studies. Therefore, the aim of this study was to investigate the dose concentration and spatial memory as well as brain mitochondrial function association after MDMA administration in rats. We assessed the effects of MDMA 0.5, 2.5, 5, 10 and 15 mg/kg; intraperitoneally (I.P) on spatial memory of male Wistar rats in the Morris water maze test (MWM) and brain mitochondrial function (i.e., reactive oxygen species, mitochondrial membrane potential, swelling and outer membrane damage, cytochrome c release, and ADP/ATP ratio). Concentrations of MDMA and its metabolite, MDA, were determined in plasma, cerebrospinal fluid (CSF) and brain which was obtained immediately after probe test of MWM (i.e., 4 h after last training trial). The results of this study indicate nonlinear kinetics of MDMA after I.P adminstration. Also, an insignificant correlation was observed between MDMA doses and the MDA/MDMA ratio in plasma, CSF, and brain. Moreover, the results showed that MDMA, but not MDA, accumulated in brain tissue by increasing the administered doses. Beside, MDMA-induced impairments of spatial memory and brain mitochondrial function were significantly correlated with the concentrations of both MDMA and MDA in plasma, CSF, and brain. Therefore, it can be suggested that MDMA and its metabolite, MDA, affect spatial memory and brain mitochondrial function. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature

Bucladesine Attenuates Spatial Learning and Hippocampal Mitochondrial Impairments Induced by 3, 4-Methylenedioxymethamphetamine (MDMA)

Neurotoxic effects of systemic administration of 3, 4- methylenedioxymethamphetamine (MDMA) has been attributed to MDMA and its metabolites. However, the role of the parent compound in MDMA-induced mitochondrial and memory impairment has not yet been investigated. Moreover, it is not yet studied that analogs of 3�, 5�-cyclic adenosine monophosphate (cAMP) could decrease these neurotoxic effects of MDMA. We wished to investigate the effects of the central administration of MDMA on spatial memory and mitochondrial function as well as the effects of bucladesine, a membrane-permeable analog of cAMP, on these effects of MDMA. We assessed the effects of pre-training bilateral intrahippocampal infusion of MDMA (0.01, 0.1, 0.5, and 1 μg/side), bucladesine (10 and 100 μM) or combination of them on spatial memory, and different parameters of hippocampal mitochondrial function including the level of reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), mitochondrial swelling, mitochondrial outer membrane damage, the amount of cytochrome c release as well as hippocampal ADP/ATP ratio. The results showed that MDMA caused spatial memory impairments as well as mitochondrial dysfunction as evidenced by the marked increase in hippocampal ADP/ATP ratio, ROS level, the collapse of MMP, mitochondrial swelling, and mitochondrial outer membrane damage leading to cytochrome c release from the mitochondria. The current study also found that bucladesine markedly reduced the destructive effects of MDMA. These results provide evidence of the role of the parent compound (MDMA) in MDMA-induced memory impairments through mitochondrial dysfunction. This study highlights the role of cAMP/PKA signaling in MDMA-induced memory and mitochondrial defects. © 2020, Springer Science+Business Media, LLC, part of Springer Nature