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https://www.readbyqxmd.com/read/28893642/enzyme-inducing-effects-of-berberine-on-cytochrome-p450-1a2-in-vitro-and-in-vivo
#1
Bo Jiang, Liyuan Meng, Feng Zhang, Xiaoling Jin, Guiliang Zhang
AIMS: Berberine (BER) is an important anti-bacterial drug from Chinese herbal medicine and a novel drug candidate for preclinical development in recent years. Here we provide evidence that the effects of berberine on cytochrome P450 (CYP) 1A2 in vitro and in vivo. MAIN METHODS: Real-time polymerase chain reaction and western blotting analysis were employed to evaluate the CYP1A2 mRNA levels and protein expression. The enzyme activity was assessed by the metabolic rate of phenacetin to acetaminophen by LC-MS/MS method...
September 8, 2017: Life Sciences
https://www.readbyqxmd.com/read/28879062/a-modeling-approach-to-evaluate-the-balance-between-bioactivation-and-detoxification-of-meiqx-in-human-hepatocytes
#2
Victorien Delannée, Sophie Langouët, Nathalie Théret, Anne Siegel
BACKGROUND: Heterocyclic aromatic amines (HAA) are environmental and food contaminants that are potentially carcinogenic for humans. 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) is one of the most abundant HAA formed in cooked meat. MeIQx is metabolized by cytochrome P450 1A2 in the human liver into detoxificated and bioactivated products. Once bioactivated, MeIQx metabolites can lead to DNA adduct formation responsible for further genome instability. METHODS: Using a computational approach, we developed a numerical model for MeIQx metabolism in the liver that predicts the MeIQx biotransformation into detoxification or bioactivation pathways according to the concentration of MeIQx...
2017: PeerJ
https://www.readbyqxmd.com/read/28841541/use-of-the-liver-maximum-function-capacity-test-limax-for-the-management-of-liver-resection-in-cirrhosis-a-case-of-hypopharyngeal-cancer-liver-metastasis
#3
S Cammann, F Oldhafer, K I Ringe, W Ramackers, K Timrott, M Kleine, J Klempnauer, F Lehner, H Bektas, F W R Vondran
INTRODUCTION: The presence of liver cirrhosis goes along with a higher chance for the need of liver resection. As established laboratory parameters often underestimate the degree of cirrhosis this is associated with an increased risk for postoperative liver failure due to the preoperatively impaired liver function. Known liver function tests are unlikely to be performed in daily use because of high cost or expenditure of time. Liver maximum function capacity test (LiMAx) provides a novel tool for measurement of liver function and references for the safety of liver resection...
August 10, 2017: International Journal of Surgery Case Reports
https://www.readbyqxmd.com/read/28834279/the-cytochrome-p450-enzyme-responsible-for-the-production-of-z-norendoxifen-in-vitro
#4
Dabei Tang, Zhong Chu, Jessica Bo Li Lu, Jinzhong Liu, Qingyuan Zhang
BACKGROUND: Norendoxifen, an active metabolite of tamoxifen, is a potent aromatase inhibitor. Little information is available regarding production of norendoxifen in vitro. Here, we conducted a series of kinetic and inhibition studies in human liver microsomes (HLMs) and expressed P450s to study the metabolic disposition of norendoxifen. METHODS: To validate that norendoxifen was the metabolite of endoxifen, metabolites in HLMs incubates of endoxifen were measured using a HPLC/MS/MS method...
August 17, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28832650/fructose-diet-alleviates-acetaminophen-induced-hepatotoxicity-in-mice
#5
Sungjoon Cho, Ashutosh Tripathi, George Chlipala, Stefan Green, Hyunwoo Lee, Eugene B Chang, Hyunyoung Jeong
Acetaminophen (APAP) is a commonly used analgesic and antipyretic that can cause hepatotoxicity due to production of toxic metabolites via cytochrome P450 (Cyp) 1a2 and Cyp2e1. Previous studies have shown conflicting effects of fructose (the major component in Western diet) on the susceptibility to APAP-induced hepatotoxicity. To evaluate the role of fructose-supplemented diet in modulating the extent of APAP-induced liver injury, male C57BL/6J mice were given 30% (w/v) fructose in water (or regular water) for 8 weeks, followed by oral administration of APAP...
2017: PloS One
https://www.readbyqxmd.com/read/28822783/the-expression-induction-and-pharmacological-activity-of-cyp1a2-are-post-transcriptionally-regulated-by-microrna-hsa-mir-132-5p
#6
Yinting Chen, Linjuan Zeng, Yong Wang, William H Tolleson, Bridgett Knox, Si Chen, Zhen Ren, Lei Guo, Nan Mei, Feng Qian, Kaihong Huang, David Liu, Weida Tong, Dianke Yu, Baitang Ning
Cytochrome P450 1A2 (CYP1A2) is one of the most abundant and important drug metabolizing enzymes in human liver. However, little is known about the post-transcriptional regulation of CYP1A2, especially the mechanisms involving microRNAs (miRNAs). This study applied a systematic approach to investigate the post-transcriptional regulation of CYP1A2 by miRNAs. Candidate miRNAs targeting the 3'-untranslated region (3'-UTR) of CYP1A2 were screened in silico, resulting in the selection of sixty-two potential miRNAs for further analysis...
August 16, 2017: Biochemical Pharmacology
https://www.readbyqxmd.com/read/28803225/carboxylesterase-1a2-encoding-gene-with-increased-transcription-and-potential-rapid-drug-metabolism-in-asian-populations
#7
Henrik Berg Rasmussen, Majbritt Busk Madsen, Yassine Kamal Lyauk, Peter Riis Hansen, Timothy Hughes
The carboxylesterase 1 gene (CES1) encodes a hydrolase implicated in the metabolism of commonly used drugs. CES1A2, a hybrid of CES1 and a CES1-like pseudogene, has a promoter that is weak in most individuals. However, some individuals harbor a promoter haplotype of this gene with two overlapping Sp1 sites that confer significantly increased transcription potentially leading to rapid drug metabolism. This CES1A2 haplotype has previously been reported to be common among Asians. Using polymerase chain reaction followed by sequencing, the present study examined variation in the promoter and 5' untranslated region of CES1A2 in 120 Han Chinese and 120 Japanese people enrolled in the 1000 Genomes Project...
August 14, 2017: Drug Metabolism and Personalized Therapy
https://www.readbyqxmd.com/read/28791666/clinical-pharmacokinetics-and-pharmacodynamics-of-micafungin
#8
REVIEW
Roeland E Wasmann, Eline W Muilwijk, David M Burger, Paul E Verweij, Catherijne A Knibbe, Roger J Brüggemann
Micafungin is a selective inhibitor of the synthesis of fungal 1,3-β-D-glucan, an essential component of the fungal cell wall. It is available as a powder for infusion only and is registered for the treatment of invasive and esophageal candidiasis in addition to prophylaxis of Candida infections in both adults and children. Average exposure after a single intravenous 100 mg dose in healthy adults is 133 mg h/L. Both exposure and maximum plasma concentration show linear dose proportional pharmacokinetics (PK) over a 0...
August 8, 2017: Clinical Pharmacokinetics
https://www.readbyqxmd.com/read/28763317/rocuronium-is-more-hepatotoxic-than-succinylcholine-in-vitro
#9
Martin Sauer, Ines Piel, Cristof Haubner, Georg Richter, Miriam Mann, Gabriele Nöldge-Schomburg, Thomas Mencke
BACKGROUND: The development of liver failure is a major problem in critically ill patients. The hepatotoxicity of many drugs, as one important reason for liver failure, is poorly screened for in human models. Rocuronium and succinylcholine are neuromuscular blocking agents used for tracheal intubation and for rapid-sequence induction. OBJECTIVE: We used an in-vitro test with a permanent cell line and compared rocuronium and succinylcholine for hepatotoxicity. DESIGN: In-vitro study...
September 2017: European Journal of Anaesthesiology
https://www.readbyqxmd.com/read/28762065/lc-high-resolution-ms-ms-for-identification-of-69-metabolites-of-the-new-psychoactive-substance-1-4-ethylphenyl-n-2-methoxyphenyl-methyl-propane-2-amine-4-ea-nbome-in-rat-urine-and-human-liver-s9-incubates-and-comparison-of-its-screening-power-with-further
#10
Achim T Caspar, Folker Westphal, Markus R Meyer, Hans H Maurer
4-EA-NBOMe (N-(2-methoxybenzyl)-4-ethylamphetamine, 1-(4-ethylphenyl-)-N-[(2-methoxyphenyl)methyl]propane-2-amine) is an amphetamine-derived new psychoactive substance (NPS) of the N-methoxybenzyl (NBOMe) group first seized by German custom authorities. In contrast to the phenethylamine NBOMes, studies on the pharmacological, toxicological, or metabolic properties are not yet published. The aims of the presented work were the use of LC-HR-MS/MS for identification of the phase I and II metabolites of 4-EA-NBOMe in rat urine and pooled human S9 fraction (pS9) incubations, to compare metabolite formation in both models, to identify involved monooxygenases, and to elucidate its detectability in standard urine screening approaches (SUSAs) using GC-MS, LC-MS(n), and LC-HR-MS/MS...
July 31, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28696416/cytochrome-p450-interactions-are-common-and-consequential-in-massachusetts-hospital-discharges
#11
T H McCoy, V M Castro, A Cagan, L Snapper, A Roberson, R H Perlis
Despite the recognition that drug-drug interactions contribute substantially to preventable health-care costs, the prevalence of such interactions related to the cytochrome P450 system in clinical practice remains poorly characterized. This study drew retrospective hospital discharge cohorts from a large health claims data set and a large health system data set. For every hospital discharge, frequency of co-occurrence of substrates and inducers or inhibitors at cytochrome P450 2D6, 2C19, 3A4 and 1A2 were determined...
July 11, 2017: Pharmacogenomics Journal
https://www.readbyqxmd.com/read/28694304/correction-to-molecular-cloning-tissue-distribution-and-functional-characterization-of-marmoset-cytochrome-p450-1a1-1a2-and-1b1
#12
(no author information available yet)
No abstract text is available yet for this article.
August 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/28678150/metabolism-of-the-marine-phycotoxin-ptx-2-and-its-effects-on-hepatic-xenobiotic-metabolism-activation-of-nuclear-receptors-and-modulation-of-the-phase-i-cytochrome-p450
#13
Jimmy Alarcan, Estelle Dubreil, Antoine Huguet, Dominique Hurtaud-Pessel, Stefanie Hessel-Pras, Alfonso Lampen, Valérie Fessard, Ludovic Le Hegarat
PTX-2 is a marine biotoxin frequently found in shellfish that can lead to food intoxication in humans. Information regarding PTX-2 metabolism is scarce, and little is known of its effect on xenobiotic-metabolizing enzymes (XME) or its molecular pathways. The aim of this study was consequently to examine PTX-2 Phase I metabolism using rat and human liver S9 fractions, and also to assess the capability of PTX-2: (i) to modulate the gene expression of a panel of Phase I (CYP450) and II (UGT, SULT, NAT, and GST) enzymes, as well as the Phase III or 0 (ABC and SLCO) transporters in the human hepatic HepaRG cell line using qPCR; (ii) to induce specific CYP450 in HepaRG cells measured by immunolabeling detection and the measurement of the cells' activities; and (iii) to activate nuclear receptors and induce CYP promoter activities in HEK-T and HepG2 transfected cell lines using transactivation and reporter gene assay, respectively...
July 5, 2017: Toxins
https://www.readbyqxmd.com/read/28668050/ionization-of-pyridine-interplay-of-orbital-relaxation-and-electron-correlation
#14
A B Trofimov, D M P Holland, I Powis, R C Menzies, A W Potts, L Karlsson, E V Gromov, I L Badsyuk, J Schirmer
The valence shell ionization spectrum of pyridine was studied using the third-order algebraic-diagrammatic construction approximation scheme for the one-particle Green's function and the outer-valence Green's function method. The results were used to interpret angle resolved photoelectron spectra recorded with synchrotron radiation in the photon energy range of 17-120 eV. The lowest four states of the pyridine radical cation, namely, (2)A2(1a2(-1)), (2)A1(7a1(-1)), (2)B1(2b1(-1)), and (2)B2(5b2(-1)), were studied in detail using various high-level electronic structure calculation methods...
June 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28653752/the-potential-of-epimedium-koreanum-nakai-for-herb-drug-interaction
#15
Qingxiang Zhong, Ziqi Shi, Li Zhang, Rongling Zhong, Zhi Xia, Jing Wang, Hao Wu, Yutong Jiang, E Sun, Yingjie Wei, Liang Feng, Zhenhai Zhang, Dan Liu, Jie Song, Xiaobin Jia
OBJECTIVES: This study aims to investigate potential herb-drug interactions (HDI) of Epimedium koreanum Nakai. METHODS: Human liver microsomes (HLMs) were used to determine the enzyme kinetics of the major human cytochrome P450s (CYPs). Inducible potential of E. koreanum on CYP1A2, 2B6, 2C19 and 3A4 activities of human primary hepatocytes was also examined. KEY FINDINGS: Ethanol extract of E. koreanum showed direct inhibitory potency for CYP1A2 (IC50  = 121...
June 27, 2017: Journal of Pharmacy and Pharmacology
https://www.readbyqxmd.com/read/28648140/oxidation-of-1-chloropyrene-by-human-cyp1-family-and-cyp2a-subfamily-cytochrome-p450-enzymes-catalytic-roles-of-two-cyp1b1-and-five-cyp2a13-allelic-variants
#16
Tsutomu Shimada, Norie Murayama, Kensaku Kakimoto, Shigeo Takenaka, Young-Ran Lim, Sora Yeom, Donghak Kim, Hiroshi Yamazaki, F Peter Guengerich, Masayuki Komori
1. 1-Chloropyrene, one of the major chlorinated polycyclic aromatic hydrocarbon contaminants, was incubated with human cytochrome P450 (P450 or CYP) enzymes including CYP1A1, 1A2, 1B1, 2A6, 2A13, 2B6, 2C9, 2D6, 2E1, 3A4 and 3A5. Catalytic differences in 1-chloropyrene oxidation by polymorphic two CYP1B1 and five CYP2A13 allelic variants were also examined. 2. CYP1A1 oxidized 1-chloropyrene at the 6- and 8-positions more actively than at the 3-position, while both CYP1B1.1 and 1B1.3 preferentially catalyzed 6-hydroxylation...
July 21, 2017: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
https://www.readbyqxmd.com/read/28644845/lipo-pge1-suppresses-collagen-production-in-human-dermal-fibroblasts-via-the-erk-ets-1-signaling-pathway
#17
Yoolhee Yang, Hee Jung Kim, Kyong-Je Woo, Daeho Cho, Sa Ik Bang
Dysregulation of collagen production contributes to various pathological processes, including tissue fibrosis as well as impaired wound healing. Lipo-prostaglandin E1 (Lipo-PGE1), a lipid microsphere-incorporated prostaglandin E1, is used as a vasodilator for the treatment of peripheral vascular diseases. Lipo-PGE1 was recently shown to enhance human dermal fibroblast (HDF) migration and in vivo wound healing. No published study has characterized the role of Lipo-PGE1 in collagen regulation in HDFs. Here, we investigated the cellular signaling mechanism by which Lipo-PGE1 regulates collagen in HDFs...
2017: PloS One
https://www.readbyqxmd.com/read/28614988/in-vitro-inhibitory-effects-of-dihydromyricetin-on-human-liver-cytochrome-p450-enzymes
#18
Lu Liu, Sen Sun, Hongbing Rui, Xiaohua Li
CONTEXT: Dihydromyricetin (DHM) is the most abundant and active flavonoid component isolated from Ampelopsis grossedentata (Hand-Mazz) W.T. Wang (Vitaceae) and it possesses numerous pharmacological activities. However, whether DHM affects the activity of human liver cytochrome P450 (CYP) enzymes remains unclear. MATERIALS AND METHODS: The inhibitory effects of DHM on eight human liver CYP isoforms (i.e., 1A2, 3A4, 2A6, 2E1, 2D6, 2C9, 2C19 and 2C8) were investigated in vitro using human liver microsomes (HLMs)...
December 2017: Pharmaceutical Biology
https://www.readbyqxmd.com/read/28609606/ambient-water-stable-dianionic-electron-donors-intramolecular-noncovalent-conduits-assist-charge-delocalization
#19
Sudhir Kumar Keshri, Sharvan Kumar, Kalyanashis Mandal, Pritam Mukhopadhyay
Electron-rich π-conjugated dianions are known to be ambient unstable and their stabilization in ambient water is yet to be realized. We report the first example of an exceptionally stable naphthalenediimide-based dianion in ambient and hot water, forming one of the most stable redox-active dianion. The half-life (t1/2 ) of dianion (1 a(2-) ) is more than four months in ambient water. The dianionic state was confirmed by X-ray crystallography and by various spectroscopic methods. The noncovalent electronic conduits introduced for the first time in dianions, embrace nO →π*C≡N interactions and aid in delocalizing the dianionic charge as validated from theoretical studies...
June 13, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28603633/in-vitro-metabolism-of-exemestane-by-hepatic-cytochrome-p450s-impact-of-nonsynonymous-polymorphisms-on-formation-of-the-active-metabolite-17%C3%AE-dihydroexemestane
#20
Amity Peterson, Zuping Xia, Gang Chen, Philip Lazarus
Exemestane (EXE) is an endocrine therapy commonly used by postmenopausal women with hormone-responsive breast cancer due to its potency in inhibiting aromatase-catalyzed estrogen synthesis. Preliminary in vitro studies sought to identify phase I EXE metabolites and hepatic cytochrome P450s (CYP450s) that participate in EXE biotransformation. Phase I metabolites were identified by incubating EXE with HEK293-overexpressed CYP450s. CYP450s 1A2, 2C8, 2C9, 2C19, 2D6, 3A4, and 3A5 produce 17β-dihydroexemestane (17β-DHE), an active major metabolite, as well as two inactive metabolites...
June 2017: Pharmacology Research & Perspectives
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