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cytochrome p450 3A4

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https://www.readbyqxmd.com/read/28221037/computational-investigation-of-ligand-binding-to-the-peripheral-site-in-cyp3a4-conformational-dynamics-and-inhibitor-discovery
#1
Hanwen Du, Junhao Li, Yingchun Cai, Hongxiao Zhang, Guixia Liu, Yun Tang, Weihua Li
Human cytochrome P450 3A4 (CYP3A4) is a major drug-metabolizing enzyme responsible for the metabolism of ~50% of clinically used drugs and is often involved in drug-drug interactions. It exhibits atypical binding and kinetic behavior towards many ligands. Binding of ligands to CYP3A4 is a complex process. Recent studies from both crystallography and biochemistry suggested the existence of a peripheral ligand-binding site at the enzyme surface. However, the stability of ligand bound at this peripheral site and the possibility of discovering new CYP3A4 ligands based on this site remain unclear...
February 21, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28214069/-pharmacokinetic-drug-interaction-between-miconazole-mucoadhesive-tablet-and-tacrolimus-about-3%C3%A2-case-reports-in-transplant-patients
#2
Marion Lepelley, Sophie Logerot, Xavier Fonrose, Céline Villier
Loramyc(®) is a mucoadhesive tablet of miconazole, indicated for the treatment of oropharyngeal candidiasis in immunocompromised patients. Miconazole, as others azole antifungals, is known for its potent inhibitory properties of cytochromes P450 enzymes and P-glycoprotein (P-gp). Inhibition of cytochromes P450 enzymes and P-gp can produce pharmacokinetic drug interaction. Immunosuppressive agents, such as calcineurin inhibitors (tacrolimus, cyclosporine) are substrates of cytochromes P450 3A4 and P-gp. Nevertheless, the impact of systemic absorption of miconazole mucoadhesive tablet has not been investigated by the laboratory before regulatory approval...
January 12, 2017: Thérapie
https://www.readbyqxmd.com/read/28196829/marmoset-cytochrome-p450-3a4-expressed-in-liver-and-small-intestine-tissues-efficiently-metabolizes-midazolam-alprazolam-nifedipine-and-testosterone
#3
Shotaro Uehara, Yasuhiro Uno, Kazuyuki Nakanishi, Sakura Ishii, Takashi Inoue, Erika Sasaki, Hiroshi Yamazaki
Common marmosets (Callithrix jacchus), small New World primates, are increasingly attracting attention as potentially useful animal models for drug development. However, characterization of cytochrome P450 (P450) 3A enzymes involved in the metabolism of a wide variety of drugs has remained in marmosets. In this study, sequence homology, tissue distribution, and enzymatic property of marmoset P450 3A4 orthologue, 3A5 orthologue, and 3A90 were investigated. Marmoset P450 3A forms exhibited high amino acid sequence identities (88-90%) to the human and cynomolgus monkey P450 3A orthologues and evolutionary closeness to human and cynomolgus monkey P450 3A orthologues, compared with other P450 3A enzymes...
February 14, 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/28194109/delayed-chemotherapy-induced-nausea-and-vomiting-pathogenesis-incidence-and-current-management
#4
REVIEW
Bernardo L Rapoport
Even when chemotherapy-induced nausea and vomiting (CINV) can be effectively controlled in the acute phase, it may still occur in the delayed phase. Identifying at-risk patients is complex and requires consideration of clinical, personal, demographic, and behavioral factors. Delayed CINV has a significant detrimental effect on patients' daily life and is responsible for significant healthcare resource utilization. Patients who do not experience acute CINV are not necessarily exempt from delayed CINV, and healthcare professionals have been shown to underestimate the incidence of delayed CINV...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28183147/synthesis-of-1%C3%AE-hydroxydeoxycholic-acid-in-h-2-and-unlabeled-forms
#5
Martin A Hayes, Ieuan Roberts, Gunnar Grönberg, Kexin Lv, Baorui Lin, Jonas Bergare, Charles S Elmore
1β-hydroxydeoxycholic acid in unlabeled and stable isotope labeled forms was required for use as a biomarker for Cytochrome P450 3A4/5. A lengthy synthesis was undertaken to deliver the unlabeled compound and in the process, to develop a route to the deuterium labeled compound. The synthesis of the unlabeled compound was completed, but in very low yield. Concurrent with the synthetic approach, a biosynthetic route was pursued and this approach proved to be much more rapid and afforded the compound in both unlabeled and deuterium labeled forms in a one-step oxidation from deoxycholic acid and [D4 ]deoxycholic acid respectively...
February 9, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
https://www.readbyqxmd.com/read/28139373/development-of-caco-2-cells-co-expressing-cyp3a4-and-nadph-cytochrome-p450-reductase-using-a-human-artificial-chromosome-for-the-prediction-of-intestinal-extraction-ratio-of-cyp3a4-substrates
#6
Toru Takenaka, Kanako Kazuki, Naomoto Harada, Jiro Kuze, Masato Chiba, Takahiro Iwao, Tamihide Matsunaga, Satoshi Abe, Mitsuo Oshimura, Yasuhiro Kazuki
The Caco-2 cells co-expressing cytochrome P450 (CYP) 3A4 and NADPH-cytochrome P450 reductase (CPR) were developed using a human artificial chromosome (HAC) vector. The CYP3A4 and CPR genes were cloned into the HAC vector in CHO cells using the Cre-loxP system, and the microcell-mediated chromosome transfer technique was used to transfer the CYP3A4-CPR-HAC vector to Caco-2 cells. After seeding onto semipermeable culture inserts, the CYP3A4-CPR-HAC/Caco-2 cells were found to form tight monolayers, similar to the parental cells, as demonstrated by the high transepithelial electrical resistance (TEER) value and comparable permeability of non-CYP3A4 substrates between parent and CYP3A4-CPR-HAC/Caco-2 cell monolayers...
August 26, 2016: Drug Metabolism and Pharmacokinetics
https://www.readbyqxmd.com/read/28129335/reduction-of-aflatoxin-b1-toxicity-by-lactobacillus-plantarum-c88-a-potential-probiotic-strain-isolated-from-chinese-traditional-fermented-food-tofu
#7
Li Huang, Cuicui Duan, Yujuan Zhao, Lei Gao, Chunhua Niu, Jingbo Xu, Shengyu Li
In this study, we investigated the potential of Lactobacillus plantarum isolated from Chinese traditional fermented foods to reduce the toxicity of aflatoxin B1 (AFB1), and its subsequent detoxification mechanism. Among all the investigated L. plantarum strains, L. plantarum C88 showed the strongest AFB1 binding capacity in vitro, and was orally administered to mice with liver oxidative damage induced by AFB1. In the therapy groups, the mice that received L. plantarum C88, especially heat-killed L. plantarum C88, after a single dose of AFB1 exposure, showed an increase in unabsorbed AFB1 in the feces...
2017: PloS One
https://www.readbyqxmd.com/read/28105513/pharmacokinetics-of-ginkgolides-a-b-and-k-after-single-and-multiple-intravenous-infusions-and-their-interactions-with-midazolam-in-healthy-chinese-male-subjects
#8
Feng Shao, Hongwen Zhang, Lijun Xie, Juan Chen, Sufeng Zhou, Jinsong Zhang, Jinru Lv, Weiwen Hao, Yunsu Ma, Yun Liu, Ning Ou, Wei Xiao
PURPOSE: Ginkgo terpene lactones meglumine injection (GMI) is a novel preparation of traditional Chinese medicine that contains ginkgolides A, B and K (GA, GB, GK, respectively) as its primary components. In this study we evaluated the safety, tolerability and pharmacokinetics of these three ginkgolides after single and multiple intravenous infusions of GMI. We also investigated the effect of GMI on cytochrome P450 3A4 (CYP3A4) in healthy Chinese volunteers. METHODS: In this open-label, placebo-controlled study 15 subjects were randomly assigned to receive GMI or matched placebo (4:1 ratio)...
January 20, 2017: European Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28105103/inhibition-of-p-glycoprotein-multidrug-resistance-associated-protein-2-and-cytochrome-p450-3a4-improves-the-oral-absorption-of-octreotide-in-rats-with-portal-hypertension
#9
Xiao-Yu Sun, Zhi-Jun Duan, Zhen Liu, Shun-Xiong Tang, Yang Li, Shou-Cheng He, Qiu-Ming Wang, Qing-Yong Chang
The aim of the present study was to increase the intestinal transport of octreotide (OCT) by targeting the first-pass impact to identify a potential method for decreasing portal vein pressure (PVP) using oral OCT. Thus, the bioavailability of intestinally absorbed OCT was evaluated in normal rats and rats with portal hypertension (PH) that had been administered P-glycoprotein/multidrug resistance-associated protein 2/cytochrome P450 3A4 (P-gp/MRP2/CYP3A4) inhibitors. The mRNA and protein expression levels of P-gp, MRP2 and CYP3A4 were evaluated in normal and PH rats with or without OCT and the inhibitors using RT-PCR, western blot and immunohistochemical analyses...
December 2016: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28097004/rifampicin-decreases-exposure-to-sublingual-buprenorphine-in-healthy-subjects
#10
Nora M Hagelberg, Mari Fihlman, Tuija Hemmilä, Janne T Backman, Jouko Laitila, Pertti J Neuvonen, Kari Laine, Klaus T Olkkola, Teijo I Saari
Buprenorphine is mainly metabolized by the cytochrome P450 (CYP) 3A4 enzyme. The aim of this study was to evaluate the role of first-pass metabolism in the interaction of rifampicin and analgesic doses of buprenorphine. A four-session paired cross-over study design was used. Twelve subjects ingested either 600 mg oral rifampicin or placebo once daily in a randomized order for 7 days. In the first part of the study, subjects were given 0.6-mg (placebo phase) or 0.8-mg (rifampicin phase) buprenorphine sublingually on day 7...
December 2016: Pharmacology Research & Perspectives
https://www.readbyqxmd.com/read/28089783/characterization-of-rat-or-human-hepatocytes-cultured-in-microphysiological-systems-mps-to-identify-hepatotoxicity
#11
Shih-Yu Chang, Jenna L Voellinger, Kirk P Van Ness, Brian Chapron, Rachel M Shaffer, Thomas Neumann, Collin C White, Terrance J Kavanagh, Edward J Kelly, David L Eaton
The liver is the main site for drug and xenobiotics metabolism, including inactivation or bioactivation. In order to improve the predictability of drug safety and efficacy in clinical development, and to facilitate the evaluation of the potential human health effects from exposure to environmental contaminants, there is a critical need to accurately model human organ systems such as the liver in vitro. We are developing a microphysiological system (MPS) based on a new commercial microfluidic platform (Nortis, Inc...
January 13, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28089686/simulations-of-cytochrome-p450-3a4-mediated-drug-drug-interactions-by-simple-two-compartment-model-assisted-static-method
#12
Katsumi Iga, Akiko Kiriyama
In order to predict cytochrome P450 3A4 (CYP3A4)-mediated drug-drug interactions (DDIs), a simple two-compartment model assisted, overall inhibition-activity (Ai, overall) method was derived based upon two concepts. One concept was that the increase in blood victim-level and fold increase in the area under the blood victim-level curve (AUCR) produced by DDI are determined entirely by Ai, overall, the hepatic availability of the victim and fraction of urinary excreted unchanged victim, where Ai, overall is determined by the perpetrator-specific CYP isoform inhibition activities (Ai,CYPs, DDI predictor-1) and victim-specific fractional CYP isoform contributions (fm,CYPs, predictor-2)...
January 12, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28078726/dissecting-the-cytochrome-p450-1a2-and-3a4-mediated-metabolism-of-aflatoxin-b1-in-ligand-and-protein-contributions
#13
Lars Olsen, Flemming S Jørgensen, Silvia Bonomo
Aflatoxin B1 (AFB1) is a chemically intriguing compound because it has several potential sites of metabolism (SOMs) while only some of them are observed experimentally. Cytochrome P450 (CYP) 3A4 and 1A2 are the major isoforms involved in its metabolism. Here, we systematically investigate reactivity and accessibility of all possible SOMs in these two CYPs to elucidate AFB1 metabolism. Density functional theory (DFT) calculations were used to determine activation energies for each possible reaction. Aliphatic hydroxylation on position 9A and 3α are energetically favored, whereas position 9 is the preferred site for epoxidation...
January 12, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28073119/in-vitro-inhibition-of-human-cyp450s-1a2-2c9-3a4-5-2d6-and-2e1-by-grandisin
#14
Maísa Daniela Habenschus, Fernanda de Lima Moreira, Norberto Peporine Lopes, Anderson R M de Oliveira
Grandisin, a lignan isolated from many species of plants, such as Virola surinamensis, is a potential drug candidate due to its biological properties, highlighted by its antitumor and trypanocidal activities. In this study, the inhibitory effects of grandisin on the activities of human cytochrome P450 enzymes were investigated by using human liver microsomes. Results showed that grandisin is a competitive inhibitor of CYP2C9 and a competitive and mechanism-based inhibitor of CYP3A4/5. The apparent Ki value for CYP2C9 was 50...
January 10, 2017: Planta Medica
https://www.readbyqxmd.com/read/28069789/hypotension-induced-by-the-concomitant-use-of-a-calcium-channel-blocker-and-clarithromycin
#15
Sayako Takeuchi, Yuki Kotani, Toshihide Tsujimoto
In the elderly, calcium-channel blockers are the first-line treatment for hypertension, and macrolides are commonly prescribed antibiotics. Here we report a 78-year-old man taking nifedipine, diltiazem and carvedilol who presented with persistent hypotension and bradycardia after clarithromycin was prescribed. He was diagnosed with drug-induced hypotension and treated with fluid resuscitation and vasoactive agents. His symptoms gradually improved. He was transferred out of the intensive care unit 3 days after hospitalisation...
January 9, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28058783/characterization-of-phase-i-and-phase-ii-hepatic-metabolism-and-reactive-intermediates-of-larrea-nitida-cav-and-its-lignan-compounds
#16
Hyesoo Jeong, Soolin Kim, Jimin Lee, Jin Young Park, Wenmei Zhou, Xiyuan Liu, So Dam Kim, Yun Seon Song, Chang-Young Jang, Sei-Ryang Oh, Sangho Choi, Minsun Chang
Larrea nitida Cav. (LNC), which belongs to the family Zygophyllaceae, is widely indigenous and used in South America to treat various pathological conditions. It contains the antioxidant and antiinflammatory but toxic nordihydroguaiaretic acid (NDGA) as well as O-methylated metabolite of NDGA (MNDGA) as bioactive compounds. The hepatic metabolism-based toxicological potential of extracts of LNC (LNE), NDGA, and MNDGA has not previously been reported. The present study aimed to characterize the phase I and phase II hepatic metabolism and reactive intermediates of LNE, NDGA, and MNDGA and their effects on the major drug-metabolizing enzymes in vitro and ex vivo...
January 2017: Phytotherapy Research: PTR
https://www.readbyqxmd.com/read/28035588/clinical-pharmacokinetics-and-pharmacodynamics-of-naloxegol-a-peripherally-acting-%C3%A2%C2%B5-opioid-receptor-antagonist
#17
REVIEW
Khanh Bui, Diansong Zhou, Hongmei Xu, Eike Floettmann, Nidal Al-Huniti
Naloxegol is a peripherally acting µ-opioid receptor antagonist approved for use as an orally administered tablet (therapeutic doses of 12.5 and 25 mg) for the treatment of opioid-induced constipation. Over a wide dose range (i.e. single supratherapeutic doses up to 1000 mg in healthy volunteers), the pharmacokinetic properties of naloxegol appear to be time- and dose-independent. Naloxegol is rapidly absorbed, with mean time to maximum plasma concentration of <2 h. Following once-daily administration, steady state is achieved within 2-3 days and minimal accumulation is observed...
December 29, 2016: Clinical Pharmacokinetics
https://www.readbyqxmd.com/read/28031486/structural-basis-for-regiospecific-midazolam-oxidation-by-human-cytochrome-p450-3a4
#18
Irina F Sevrioukova, Thomas L Poulos
Human cytochrome P450 3A4 (CYP3A4) is a major hepatic and intestinal enzyme that oxidizes more than 60% of administered therapeutics. Knowledge of how CYP3A4 adjusts and reshapes the active site to regioselectively oxidize chemically diverse compounds is critical for better understanding structure-function relations in this important enzyme, improving the outcomes for drug metabolism predictions, and developing pharmaceuticals that have a decreased ability to undergo metabolism and cause detrimental drug-drug interactions...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27995413/is-cytochrome-p450-3a4-regulated-by-menstrual-cycle-hormones-in-control-endometrium-and-endometriosis
#19
MULTICENTER STUDY
Carla A Piccinato, Rosa M Neme, Natália Torres, Renata Silvério, Vanessa Bitencourt Pazzini, Júlio C Rosa E Silva, Rui A Ferriani
The estrogen-metabolizing activities of cytochrome P450 (CYP) enzymes have been implicated in endometriosis. However, their regulation in various sources of endometrial tissue under different hormonal conditions has not been clarified. Our objective was to study the hormone regulation of a specific CYP enzyme, namely CYP3A4, in control (n = 15) and endometriosis patients (n = 42). To this end, we evaluated mRNA expression (using real-time PCR) of CYP3A4 in tissue samples classified according to the phase of menstrual cycle at which they were obtained as confirmed by the related circulating hormone levels...
March 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/27994733/identification-synthesis-and-biological-evaluation-of-the-major-human-metabolite-of-nlrp3-inflammasome-inhibitor-mcc950
#20
Manohar Salla, Mark S Butler, Ruby Pelingon, Geraldine Kaeslin, Daniel E Croker, Janet C Reid, Jong Min Baek, Paul V Bernhardt, Elizabeth M J Gillam, Matthew A Cooper, Avril A B Robertson
MCC950 is an orally bioavailable small molecule inhibitor of the NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome that exhibits remarkable activity in multiple models of inflammatory disease. Incubation of MCC950 with human liver microsomes, and subsequent analysis by HPLC-MS/MS, revealed a major metabolite, where hydroxylation of MCC950 had occurred on the 1,2,3,5,6,7-hexahydro-s-indacene moiety. Three possible regioisomers were synthesized, and coelution using HPLC-MS/MS confirmed the structure of the metabolite...
December 8, 2016: ACS Medicinal Chemistry Letters
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