Search results for "P3a"
showing 10 items of 98 documents
The Influence of Single-Dose and Short-Term Administration of Quercetin on the Pharmacokinetics of Midazolam in Humans.
2015
Quercetin is a plant flavonol that is available from both daily diet and nutraceuticals. To investigate the effect of acute and short-term intake of high-dose quercetin on CYP3A-mediated metabolism, 10 healthy volunteers received 7.5 mg oral midazolam without, with a single dose of 1500 mg quercetin and after 1-week supplementation with 1500 mg quercetin daily. A substudy was performed in three subjects to explore the impact of repeated quercetin intake on intravenously administered midazolam. Coadministration with a single dose of quercetin did not significantly alter the pharmacokinetics of midazolam and its 1'-hydroxymetabolite, but following short-term quercetin intake, there was a tren…
CYP3 phylogenomics: evidence for positive selection of CYP3A4 and CYP3A7.
2008
CYP3A metabolizes 50% of currently prescribed drugs and is frequently involved in clinically relevant drug interactions. The understanding of roles and regulations of the individual CYP3A genes in pharmacology and physiology is incomplete.Using genomic sequences from 16 species we investigated the evolution of CYP3 genomic loci over a period of 450 million years.CYP3A genes in amniota evolved from two ancestral CYP3A genes. Upon the emergence of eutherian mammals, one of them was lost, whereas, the other acquired a novel genomic environment owing to translocation. In primates, CYP3A underwent rapid evolutionary changes involving multiple gene duplications, deletions, pseudogenizations, and …
The role of red yeast rice (RYR) supplementation in plasma cholesterol control: A review and expert opinion.
2019
1. Preamble : Hypercholesterolemia is a major risk factor for atherosclerotic cardiovascular disease (ASCVD) [1]. Increased levels of low density lipoprotein cholesterol (LDL-C) are associated with an increased risk of coronary heart disease (CHD) and many clinical trials have shown that reducing LDL-C levels significantly reduced the CHD and CVD risk [[2], [3], [4], [5]]. Thus LDL-C-lowering is the main approach for the management of cardiovascular disease. Current guidelines suggest LDL-C levels targets based on the individual CV risk; such targets can be achieved by several means, which include both lifestyle changes and pharmacological approaches [6], with statins being the cornerstone …
Sex-dependent genetic markers of CYP3A4 expression and activity in human liver microsomes
2007
Objective: To find genetic markers of the individual cytochrome P450 (CYP)3A expression. Methods: A large collection of liver samples phenotyped for CYP3A expression and activity was genotyped for CYP3A variants. Data were analyzed for associations between CYP3A phenotypes and genotypes, and for evidence of recent selection. Results: We report associations between the hepatic CYP3A4 protein expression level, as well as its enzymatic activity, measured as verapamil N-dealkylation, and genetic polymorphisms from two regions within the CYP3A gene cluster. One region is defined by several variants, mostly located within CYP3A7, the other by a single nucleotide polymorphism in intron 7 of CYP3A…
CYP2D6 increases toxicity of the designer drug 4-methylthioamphetamine (4-MTA)
2006
4-Methylthioamphetamine (4-MTA) belongs to a group of new amphetamine derivatives that is usually sold as "ecstasy" or "flatliners" on the illicit drug market. Large interindividual differences in 4-MTA mediated toxicity have been reported in humans. Therefore, we tested whether CYP2D6 or its variant alleles as well as CYP3A4 influence the susceptibility to 4-MTA. For this purpose, we used the colony formation assay with Chinese hamster lung fibroblast V79 cells expressing human wild-type CYP2D6 (CYP2D6*1), the low activity alleles CYP2D6*2, CYP2D6*9, as well as human CYP3A4. The obtained results showed that the expression of wild type CYP2D6*1 clearly enhanced the susceptibility to the cyt…
Pharmacogenetic considerations for optimizing tacrolimus dosing in liver and kidney transplant patients
2013
The introduction of tacrolimus in clinical practice has improved patient survival after organ transplant. However, despite the long use of tacrolimus in clinical practice, the best way to use this agent is still a matter of intense debate. The start of the genomic era has generated new research areas, such as pharmacogenetics, which studies the variability of drug response in relation to the genetic factors involved in the processes responsible for the pharmacokinetics and/or the action mechanism of a drug in the body. This variability seems to be correlated with the presence of genetic polymorphisms. Genotyping is an attractive option especially for the initiation of the dosing of tacrolim…
Effect of CYP3A5*3 on kidney transplant recipients treated with tacrolimus: a systematic review and meta-analysis of observational studies
2014
The highly variable pharmacokinetics of tacrolimus can hamper the optimal management of kidney transplant patients. This variability has been attributed to the genetic polymorphism of CYP3A5 6986A>G, but the evidence is not clear. We conducted a meta-analysis of studies evaluating the effect of CYP3A5 polymorphism on kidney transplant recipients with tacrolimus plasma concentration divided by daily dose per body weight (C/D) and clinical outcomes. We searched in MEDLINE and EMBASE. We found evidence suggesting a significantly lower C/D among CYP3A5*1 allele carriers compared with carriers of the CYP3A5*3/*3 genotype at weeks 1 and 2, and months 1, 3, 6 and 12. We demonstrated that the expre…
Characterisation of the structure-function relationship of the Bacillus thuringiensis Vip3A insecticidal proteins
2017
L'agricultura contemporània exigeix cada cop més un ús sostenible d’agroquímics per tal de reduir l'impacte ambiental i el risc per la salut del consumidor. Alguns bacteris entomopatògens produeixen proteïnes insecticides que s'acumulen en cossos d'inclusió o cristalls paraesporales (com ara les proteïnes Cry i Cyt), així com proteïnes insecticides que són secretades al medi de cultiu. Entre les últimes, hi ha les proteïnes Vip, que es divideixen en quatre famílies d'acord amb la seva identitat d'aminoàcids. Les proteïnes Vip1 i Vip2 actuen com toxines binàries i són tòxiques per a alguns coleòpters i hemípters. Per la família de les Vip4, que és l’última família de proteïnes Vip descoberta…
Structure–activity relationships, and drug metabolism and pharmacokinetic properties for indazole piperazine and indazole piperidine inhibitors of RO…
2007
ROCK has been implicated in many diseases ranging from glaucoma to spinal cord injury and is therefore an important target for therapeutic intervention. In this study, we have designed a series of 1-(4-(1H-indazol-5-yl)piperazin-1-yl)-2-hydroxy(or 2-amino) analogs and a series of 1-(4-(1H-indazol-5-yl amino)piperidin-1-yl)-2-hydroxy(or 2-amino) inhibitors of ROCK-II. SR-1459 has IC50 = 13 nM versus ROCK-II while the IC50s for SR-715 and SR-899 are 80 nM and 100 nM, respectively. Many of these inhibitors, especially the 2-amino substituted analogs for both series, are modest/potent CYP3A4 inhibitors as well. However, a few of these inhibitors (SR-715 and SR-899) show strong selectivity for R…
Genetic signature consistent with selection against the CYP3A4*1B allele in non-African populations.
2005
Cytochrome P450 3A enzymes (CYP3A) play a major role in the metabolism of steroid hormones, drugs and other chemicals, including many carcinogens. The individually variable CYP3A expression, which remains mostly unexplained, has been suggested to affect clinical phenotypes. We investigated the CYP3A locus in five ethnic groups. The degree of linkage disequilibrium (LD) differed among ethnic groups, but the most common alleles of the conserved LD regions were remarkably similar. Non-African haplotypes are few; for example, only four haplotypes account for 80% of common European Caucasian alleles. Large LD blocks of high frequencies were suggestive of selection. Accordingly, European Caucasia…