Read by QxMD icon Read

Drug Metabolism Letters

Fadzilah Adibah Abd Majid, Nur Syukriah Ab Rahman, Effendy Abd Wahid, Ain Nabihah Zainudin, Siti Nurazwa Zainol, Hassan Fahmi Ismail, Tet Soon Wong, K Vijaya Bhargava, Nirbhay Kumar Tiwari, Sanjeev Giri
Drug interaction of SynacinnTM polyherbal with known diabetic drugs is unknown. SynacinnTM contains standardized extracts of five herbal against gallic acid, curcumin, rosmarinic acid, catechin and andrographolide. SynacinnTM and its five standard markers were analysed for its possible interaction with CYP450 enzymes assay. This study was conducted using liquid chromatography-tandem mass spectroscopy (LC-MS/MS) using probe substrates using human liver microsomes against CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4(Midazolam) and CYP3A4 (Testosteron)...
March 13, 2018: Drug Metabolism Letters
Natalia Vladimirovna Mesonzhnik, Natalia Moskaleva, Ksenia Shestakova, Ksenia Kurynina, Pavel Baranov, Natalia Gretskaya, Igor Serkov, Igor Lyubimov, Vladimir Bezuglov, Svetlana Appolonova
OBJECTIVE: Nitroproston is a novel prostaglandin-based compound modified by NO-donating groups with potential application in obstructive respiratory diseases such as asthma and obstructive bronchitis. Nitroproston have been extensively studied using various pharmacological models. Its biological stability is still uncertain. The main aim of the present study was to evaluate Nitroproston stability in vitro, as well as to identify and characterize its major biodegradation products. METHODS: The principal biodegradation products of Nitroproston were identified in vitro using liquid chromatography/ion trap - time-of-flight mass-spectrometry...
March 9, 2018: Drug Metabolism Letters
Akira Ogasawara, Nozomu Kato, Nao Torimoto, Fumika Aohara, Rikiya Ohashi, Yasuhiro Yamada, Hideki Taniguchi
BACKGROUND: The HepaRG cells have key drug metabolism functionalities comparable to those of primary human hepatocytes. Many studies have reported that this cell line can be used as a reliable in vitro model for human drug metabolism studies, including the assessment of cytochrome P450 (CYP) induction. OBJECTIVES: The objective of this study is to determine whether CYP mRNA level measurement is superior to the CYP enzyme activity measurement as a convenient high-throughput method for evaluating CYP induction potential using HepaRG cells...
January 18, 2018: Drug Metabolism Letters
Jean Simmermacher, Michael Sinz
BACKGROUND: The nuclear hormone receptor, farnesoid X receptor (FXR) regulates the transcription of genes associated with bile acid metabolism and disposition. OBJECTIVE: This study investigates possible changes in the expression of target genes responsible for amino acid conjugation, i.e., bile acid-CoA synthetase (BACS) and bile acid-CoA: amino acid N-acetyltransferase (BAT). These genes have been shown to be inducible by FXR agonists in rat models, however, to date no studies have been conducted in a human hepatocyte model...
December 27, 2017: Drug Metabolism Letters
Zhengyin Yan, Susan Wong, Jane Kelly, Hoa Le, Ning Liu, Mika Kosaka, Suzanne Tey, Peter Vuong, Albert Li
A recent advancement in isolation and cryopreservation has resulted in commercially available primary human enterocytes that express various drug metabolizing enzymes (DMEs) and transporters. The main objective of this study was to further evaluate the utility of pooled cryopreserved enterocytes, specifically MetMax™ cryopreserved human enterocytes (In Vitro ADMET Laboratories), as an in vitro model for assessing intestinal clearance in comparison to hepatocytes. It was found that, for CYP3A4 substrates such as midazolam, amprenavir and loperamide, in vitro metabolic clearance is generally lower in enterocytes compared to that of hepatocytes, which is consistent with the relative abundance of the enzyme between the intestine and liver...
December 12, 2017: Drug Metabolism Letters
Cyprian Ogbonna Onyeji, Sharon I Igbinoba, Gbola Olayiwola
There has been an increase in the use of herbal products to complement conventional drugs in the treatment of various diseases especially in developing countries. This may be attributable to the relatively cost-effectiveness and ease of accessibility of these products as well as the perception of their safety profiles. However, there are numerous literature reports on herbs altering the pharmacokinetics and pharmacodynamics of other co-administered drugs thereby modulating the therapeutic outcomes. The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health...
November 20, 2017: Drug Metabolism Letters
Suresh K Balani
No abstract text is available yet for this article.
November 17, 2017: Drug Metabolism Letters
Sho Yoshitake, Melissa McKay-Daily, Masaki Tanaka, Zeqi Huang
BACKGROUND: Within the sulfotransferase (SULT) superfamily of metabolic enzymes, SULT1A1 and 1A3/4 isoforms are of particular interest, due to their abilities to catalyze the sulfation of phenolic endobiotics and xenobiotics. Although the difference in their substrate specificity is well documented, an isoform-specific quantification method is still not available. OBJECTIVE: To detect and quantify SULT1A1 and 1A3/4 in S9 fractions and cell lines using targeted mass spectrometry-based proteomics...
November 17, 2017: Drug Metabolism Letters
Ryan H Takahashi, Cyrus Khojasteh, Matthew Wright, Cornelis E C A Hop, Shuguang Ma
BACKGROUND: The regulatory guidances on metabolites in safety testing (MIST) by US Food and Drug Administration (FDA) and International Conference on Harmonisation (ICH) describe the necessity to assess exposures of major circulating metabolites in humans at steady state relative to exposures achieved in nonclinical safety studies prior to the initiation of large scale clinical trials. This comparison can be accomplished by measuring metabolite concentrations in animals and humans with validated bioanalytical methods...
November 17, 2017: Drug Metabolism Letters
Masatoshi Masuda, Tsutomu Fujiwara, Masayuki Matsunaga, Takehisa Matsumaru
BACKGROUND: CYP2D6 is one of the most significant polymorphic genes of drugmetabolizing enzymes due to its association with different metabolic activities and the pharmacokinetics of CYP2D6 substrates. OBJECTIVE: The objective of this study was to explore for a novel haplotype of CYP2D6 in the Japanese population by using a large database of previous clinical studies. METHODS: We analyzed CYP2D6 genotype data from a total of 723 Japanese individuals for 8 loci (100C>T, 1758G>A, 1846G>A, 2573 insertion of C, 2850C>T, 2988G>A, 4125 insertion of 9bp, and 4180G>C) and gene deletion...
November 17, 2017: Drug Metabolism Letters
Valentina M Fokina, Svetlana L Patrikeeva, Cheryl Oncken, Gary D V Hankins, Mahmoud S Ahmed, Tatiana Nanovskaya
BACKGROUND: Bupropion (BUP) has a potential to be an effective pharmacotherapy for smoking cessation during pregnancy. Smoking during pregnancy stimulates placental carbonyl reductases that catalyze the biotransformation of BUP. 4-methylnitrosamino-1-(3-pyridyl)-1-butanone (NNK) is a potent carcinogen of cigarette smoke. Carbonyl reduction of NNK into 4- methylnitrosamino-1-(3-pyridyl)-1-butanol (NNAL) constitutes a major step in NNK detoxification. Thus, placentas of pregnant smokers on BUP therapy can become a site of drug-drug interaction...
November 17, 2017: Drug Metabolism Letters
Ricardo Jorge Dinis-Oliveira
BACKGROUND: Flunitrazepam (FNZ) is a potent hypnotic, sedative, and amnestic drug used to treat insomnia and as a pre-anesthetic agent. The illicit practice in drug-facilitated sexual assault led to important clinical and forensic concerns. OBJECTIVE: In this work the metabolism of FNZ, and pharmacological- and toxicological-related effects, were fully reviewed. METHODS: FNZ and related known metabolizing enzymes and metabolites were searched in books and in PubMed (U...
November 17, 2017: Drug Metabolism Letters
Rebecca Kent, Hyunyoung Jeong
BACKGROUND: Cytochrome P450 (CYP) 2D6 is a major drug-metabolizing enzyme, responsible for eliminating 25% of marketed drugs. We recently identified SHP as a negative regulator of CYP2D6 expression and showed that factors that alter SHP expression influence CYP2D6 expression. Fenofibrate, an agonist of peroxisome proliferator-activated receptor α(PPARα), has been previously reported to upregulate SHP expression in the mouse liver. The objective of this study was to determine whether fenofibrate decreases CYP2D6 expression via upregulating SHP expression...
November 17, 2017: Drug Metabolism Letters
Kaoru Kobayashi, Chihiro Abe, Mika Endo, Yasuhiro Kazuki, Mitsuo Oshimura, Kan Chiba
BACKGROUND: Cytochrome P450 3A4 (CYP3A4) is an important drug-metabolizing enzyme that is expressed in the liver and small intestine of humans. Various factors influence the expression of CYP3A4, but gender difference in CYP3A4 expression remains debatable. OBJECTIVE: To clarify gender difference of hepatic and intestinal CYP3A4 in CYP3A-humanized mice generated by a human artificial chromosome (HAC) vector system. The CYP3A-humanized (CYP3AHAC) mice have essential regulatory regions, including promoters and enhancers, and unknown elements affecting the expression of CYP3A4...
November 17, 2017: Drug Metabolism Letters
Takeshi Miura, Katsutoshi Nagai, Shingo Kaneshiro, Ayako Taketomi, Toshikatsu Nakabayashi, Hiroki Konishi, Toru Nishinaka, Tomoyuki Terada
BACKGROUND AND OBJECTIVE: Doxorubicin, an anthracycline anti-cancer drug, is effective for breast cancer and childhood lymphoma. Chronic cardiotoxicity has been known as a critical adverse effect of doxorubicin and is attributed to its metabolite doxorubicinol produced by carbonyl reductase 1 (CBR1, SDR21C1). Some flavonoids have been reported to act as inhibitors for CBR1, therefore, commercially available juices containing flavonoids are likely to be applicable as a prophylactic treatment against doxorubicin-induced cardiotoxicity by suppression of doxorubicinol production...
November 17, 2017: Drug Metabolism Letters
Nicholas B Norgard, Scott V Monte
BACKGROUND: Clopidogrel is a key antiplatelet drug that has substantial interpatient variability in pharmacodynamic response. Patients with lesser degrees of platelet inhibition in response to clopidogrel appear to be at increased risk of cardiovascular events. Obesity is an independent risk factor for cardiovascular morbidity and mortality due to atherothrombotic events and represents a group of patients who are in need of optimized antithrombotic therapy. Central to the obesity-related risk of atherothrombosis is a pro-thrombotic state characterized by increased levels of coagulation factors, impaired fibrinolysis and platelet hyper-reactivity, which results from the interaction among the features clustering in obesity: insulin resistance, inflammation, oxidative stress, and endothelial dysfunction...
November 17, 2017: Drug Metabolism Letters
Parmita Chowdhury, Rita Mahantab
BACKGROUND: Frequent non-medicated use of anabolic androgenic steroids (AAS) is an instance of substance abuse which mimics the status of a natural hormone and upon prolonged exposure may lead to adverse drug reactions. These adverse drug reactions proceed in a manner so as to alter the normal metabolism of an enzyme mediated pathway such as the cytochrome P450 (CYP) family of enzymes. OBJECTIVE: The present study was conducted to investigate the impact of overuse of Nandrolone Decanoate (ND), an AAS, upon CYP enzyme activity and a CYP gene, belonging to CYP1 family...
November 14, 2017: Drug Metabolism Letters
Mithat Gunduz, Amanda L Cirello, Peter Klimko, Jennifer L Dumouchel, Upendra A Argikar
BACKGROUND: 4-(piperazin-1-yl)-8-(trifluoromethyl)pyrido[2,3-e][1,2,4]triazolo[4,3-a]pyrazine (1) is small-molecule which demonstrated a sub-nM inhibitory potency toward the histamine H4 receptor (H4R). However, it was found to be mutagenic an in vitro Ames assay. Metabolic bioactivation of 1 could potentially arise from the piperazine moiety by forming reactive intermediates such as glyoxal, aldehyde-imine and/or iminium ion, which could all lead to genotoxicity. The aim was to investigate bioactivation of 1 to determine the potential causes of the genotoxicity and mitigate liabilities in this scaffold...
November 6, 2017: Drug Metabolism Letters
Jonathan Cheong, Jason S Halladay, Jasleen K Sodhi, Emile Plise, Laurent Salphati
BACKGROUND: Non-selective chemical inhibitors of phase I and phase II enzymes are commonly used in in vitro metabolic studies to elucidate the biotransformation pathways of drugs. However, the inhibition of the inhibitors on efflux and uptake transporters is not well investigated, potentially leading to unexpected and ambiguous results in these studies. OBJECTIVE: The commonly used metabolizing enzyme inhibitors, 1-aminobenzotriazole (ABT), SKF-525A, pargyline, allopurinol, menadione, methimazole, piperine and raloxifene, were examined for their potential inhibition of the major hepatic ABC (ATP binding cassette) and SLC (solute carrier) transporters...
October 10, 2017: Drug Metabolism Letters
Jennifer L Dumouchel, Upendra A Argikar, Jaimie Spear, Ann Brown, Christine E Dunne, Valerie M Kramlinger, Amanda L Cirello, Mithat Gunduz
BACKGROUND: Timolol is clinically administered topically (ocular) to reduce intraocular pressure and treat open-angle glaucoma. Ocular administration of timolol in low doses (0.5% w/v in the form of eye drops) has led to challenges for in vivo metabolite identification. An understanding of drug metabolism in the eye is important for clinical ocular therapeutics and potential drug candidates. METHODS: We aimed to investigate the metabolism of timolol in rat ocular and liver S9 fractions, as well as rat ocular tissue and plasma following a 0...
September 11, 2017: Drug Metabolism Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"