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Marjolein Drent, Petal Wijnen, Aalt Bast
PURPOSE OF REVIEW: Fibrosing interstitial pneumonias are associated with various stages of fibrosis. The cause of this group of syndromes remains largely unknown. For most of these diseases, a genetic basis, environmental factors and certain triggers have been suggested as possible risk factors. Various studies have found an association between genetic polymorphisms, or the presence of certain variant alleles, and the occurrence and/or progression of interstitial pneumonias of unknown origin...
March 13, 2018: Current Opinion in Pulmonary Medicine
Amy L Patton, Kathryn A Seely, Azure L Yarbrough, William Fantegrossi, Laura P James, Keith R McCain, Ryoichi Fujiwara, Paul L Prather, Jeffery H Moran, Anna Radominska-Pandya
Synthetic cannabinoids (SCBs), synonymous with 'K2', 'Spice' or 'synthetic marijuana', are psychoactive drugs of abuse that frequently result in clinical effects and toxicity more severe than those classically associated with Δ9 -tetrahydrocannabinol such as extreme agitation, hallucinations, supraventricular tachycardia, syncope, and seizures. JWH-018 is one of the earliest compounds identified in various SCB products, and our laboratory previously demonstrated that JWH-018 undergoes extensive metabolism by cytochromes P450 (P450), binds to, and activates cannabinoid receptors (CBRs)...
March 6, 2018: Biochemical and Biophysical Research Communications
Alfonso T Garcia-Sosa
Leishmaniasis, malaria, and fungal diseases are burdens on individuals and populations and can present severe complications. Easily accessible chemical treatments for these diseases are increasingly sought-after. Targeting the parasite N-myristoyl transferase while avoiding the human enzyme and other anti-targets may allow the prospect of compounds with pan-activity against these diseases, which would simplify treatments and costs. Developing chemical libraries, both virtual and physical, that have been filtered and flagged early on in the drug discovery process (before virtual screening) could reduce attrition rates of compounds being developed and failing late in development stages due to problems of side-effects or toxicity...
March 8, 2018: Current Computer-aided Drug Design
Boon Hooi Tan, Nafees Ahemad, Yan Pan, Uma Devi Palanisamy, Iekhsan Othman, Beow Chin Yiap, Chin Eng Ong
Many dietary supplements are promoted to patients with osteoarthritis (OA) including the three naturally derived compounds, glucosamine, chondroitin and diacerein. Despite their wide spread use, research on interaction of these antiarthritic compounds with human hepatic cytochrome P450 (CYP) enzymes is limited. This study aimed to examine the modulatory effects of these compounds on CYP2C9, a major CYP isoform, using in vitro biochemical assay and in silico models. Utilizing valsartan hydroxylase assay as probe, all forms of glucosamine and chondroitin exhibited IC50 values beyond 1000 μM, indicating very weak potential in inhibiting CYP2C9...
February 27, 2018: Biopharmaceutics & Drug Disposition
Satoshi Koyama, Hiroshi Arakawa, Manabu Itoh, Norio Masuda, Kentaro Yano, Hajime Kojima, Takuo Ogihara
The NanoCulture Plate (NCP) is a novel microstructural plate designed as a base for the three-dimensional culture of cells/tissues. Here, we examined whether or not the metabolic capability of human primary hepatocytes is well maintained during culture on NCPs. The hepatocytes formed aggregates after seeding and their ATP content was well maintained during culture for 21 days. Expression of CYP1A2, 2B6, 2C9, 2C19, 2D6, 2E1 and 3A4 mRNAs was detected throughout the 21-day culture period. Addition of CYP substrate drugs (midazolam, diclofenac, lamotrigine and acetaminophen) resulted in the formation of multiple metabolites with a corresponding decrease in the amounts of the unchanged compounds...
February 22, 2018: Biopharmaceutics & Drug Disposition
Taha Ahmad, Monica A Valentovic, Gary O Rankin
Methadone is a synthetic, long-acting opioid with a single chiral center forming two enantiomers, (R)-methadone and (S)-methadone, each having specific pharmacological actions. Concentrations of (R)- and (S)-methadone above therapeutic levels have the ability to cause serious, life-threatening, and fatal side effects. This toxicity can be due in part to the pharmacogenetics of an individual, which influences the pharmacokinetic and pharmacodynamic properties of the drug. Methadone is primarily metabolized in the liver by cytochrome P450 (CYP) enzymes, predominately by CYP2B6, followed by CYP3A4, 2C19, 2D6, and to a lesser extent, CYP2C18, 3A7, 2C8, 2C9, 3A5, and 1A2...
February 16, 2018: Biochemical Pharmacology
Yi-An Bi, Jian Lin, Sumathy Mathialagan, Laurie Tylaska, Ernesto Callegari, A David Rodrigues, Manthena V S Varma
Inter-individual variability in warfarin dose requirement demands personalized medicine approaches to balance its therapeutic benefits (anticoagulation) and bleeding risk. Cytochrome P450 2C9 (CYP2C9) genotype-guided warfarin dosing is recommended in the clinic, given the more potent S-warfarin is primarily metabolized by CYP2C9. However, only about 20-30% of inter-patient variability in S-warfarin clearance is associated with CYP2C9 genotype. We evaluated the role of hepatic uptake in the clearance of R- and S-warfarin...
February 12, 2018: Molecular Pharmaceutics
Agata Hanna Bryk, Ewa Wypasek, Krzysztof Plens, Magdalena Awsiuk, Anetta Undas
INTRODUCTION: Single nucleotide polymorphisms (SNP) in genes encoding proteins involved in metabolism and action of vitamin K antagonists (VKA) affect anticoagulation stability. We investigated how those polymorphisms influence bleeding rates in patients following venous thromboembolism (VTE). MATERIALS AND METHODS: In 324 patients following unprovoked VTE, 143 (44%) on warfarin and 181 (56%) on acenocoumarol, we recorded bleedings within the preceding 24 months...
February 9, 2018: Vascular Pharmacology
Yanhong Sun, Shuqi Wang, Jianbo Ji, Guangxi Zhai, Jie Xing
Naphthoquine (NQ) is one of important partner drugs of Artemisinin-based combination therapy (ACT), which is recommended for the treatment of uncomplicated Plasmodium falciparum. NQ shows a high cure rate after a single oral administration. It is absorbed quickly (Tmax 2-4 h) and has a long elimination half-life (255 h). However, the metabolism of NQ has not been clarified. In this work, the metabolite profiling of NQ was studied in six liver microsomal incubates (human, cynomolgus monkey, beagle dog, mini pig, rat and CD1 mouse), seven recombinant CYP enzymes (1A2, 2B6, 2C8, 2C9, 2C19, 2D6 and 3A4) and rat (plasma, urine, bile and feces ) using liquid chromatography tandem high-resolution LTQ-Orbitrap mass spectrometry (HRMSn ) in conjunction with online H/D exchange...
February 12, 2018: Biomedical Chromatography: BMC
Jiří Vrba, Barbora Papoušková, Lenka Roubalová, Martina Zatloukalová, David Biedermann, Vladimír Křen, Kateřina Valentová, Jitka Ulrichová, Jan Vacek
This study examined the in vitro biotransformation of eight structurally related flavonolignans, namely silybin, 2,3-dehydrosilybin, silychristin, 2,3-dehydrosilychristin, silydianin, 2,3-dehydrosilydianin, isosilybin A and isosilybin B. The metabolic transformations were performed using primary cultures of human hepatocytes and recombinant human cytochromes P450 (CYPs 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4). The metabolites produced were analyzed by ultra-performance liquid chromatography coupled with tandem mass spectrometry...
January 30, 2018: Journal of Pharmaceutical and Biomedical Analysis
Sang-In Park, Ji-Young Park, Min-Ju Park, Sung-Vin Yim, Bo-Hyung Kim
Ojeok-san is a frequently used herbal medication for the management of osteoarthritic pain. We evaluated the effect of Ojeok-san on the pharmacokinetics of celecoxib at steady state in healthy subjects. An open-label, fixed-sequence, two-period, two-treatment cross-over study was conducted. In period I, the subjects received celecoxib capsule 200 mg once daily for 4 days. In period II, only Ojeok-san (14.47 g/pack, three times daily) was administered for 4 days, followed by co-administration with celecoxib for 4 days...
January 28, 2018: Basic & Clinical Pharmacology & Toxicology
Ryuta Asaumi, Kota Toshimoto, Yoshifusa Tobe, Kenta Hashizume, Ken-Ichi Nunoya, Haruo Imawaka, Wooin Lee, Yuichi Sugiyama
This study aimed to construct a physiologically based pharmacokinetic (PBPK) model of rifampicin that can accurately and quantitatively predict complex drug-drug interactions (DDIs) involving its saturable hepatic uptake and auto-induction. Using in silico and in vitro parameters, and reported clinical pharmacokinetic data, rifampicin PBPK model was built and relevant parameters for saturable hepatic uptake and UDP-glucuronosyltransferase auto-induction were optimized by fitting. The parameters for cytochrome P450 (CYP) 3A and CYP2C9 induction by rifampicin were similarly optimized using clinical DDI data with midazolam and tolbutamide as probe substrates, respectively...
January 25, 2018: CPT: Pharmacometrics & Systems Pharmacology
Nadezhda Pilipenko, Martin Krøyer Rasmussen, Olena Doran, Galia Zamaratskaia
Warfarin is a commonly used anticoagulant drug and is a derivate of coumarin. Cytochrome P450 2C9 (CYP2C9) plays the key role in transformation of coumarin and thus, influences determination of warfarin dosage. A number of factors including dietary compounds such as sesamin, caffeic acid and ferulic acids can regulate the activity of CYP2C9. The present study tested the hypothesis that sesamin, episesamin, caffeic acid and ferulic acid decreases the rate of warfarin 7-hydroxylation via inhibition of hepatic CYP2C9...
January 15, 2018: Food and Chemical Toxicology
Maiko Nomoto, Cynthia A Zamora, Edgar Schuck, Peter Boyd, Min-Kun Chang, Jagadeesh Aluri, Y Amy Siu, W George Lai, Sanae Yasuda, Jim Ferry, Bhaskar Rege
AIMS: Avatrombopag, a thrombopoietin receptor agonist, is a substrate of cytochrome P450 (CYP) 2C9 and CYP3A. We assessed three drug-drug interactions of avatrombopag as a victim with dual or selective CYP2C9/3A inhibitors and inducers. METHODS: This was a 3-part, open-label study. Forty-eight healthy subjects received single 20 mg doses of avatrombopag alone or with one of 3 CYP2C9/3A inhibitors or inducers: fluconazole 400 mg once daily for 16 days, itraconazole 200 mg twice daily on Day 1 and 200 mg once daily on Days 2-16, or rifampin 600 mg once daily for 16 days...
January 16, 2018: British Journal of Clinical Pharmacology
Mohammad Usman Mirza, Nazia Ikram, Nauman Mazhar, Kanzal Iman, Mehwish Riaz, Mohammad A Kamal
Alzheimer disease (AD) is a hot research topic currently across the world, characterized by the formation of β-amyloid plaques and neurofibrillary tangles. Inhibition of acetylcholinesterase (AChE) has gained much importance since the discovery of the involvement of peripheral anionic site (PAS) as an allosteric regulator of AChE. Progression of this neurodegenerative disorder causes a deficit in the cholinergic activity that leads towards cognitive decline. Therapeutic interventions in AD are largely focused upon AChE inhibitors designed essentially to prevent the loss of cholinergic function...
January 15, 2018: CNS & Neurological Disorders Drug Targets
Yang Xu, Xu Mao, Boyang Qin, Ying Peng, Jiang Zheng
Rhein (RH), 4,5-dihydroxyanthrauinone-2-carboxylic acid, is found in rhubarb (Dahuang), a traditional herbal medicine. RH has reportedly demonstrated multiple pharmacologic properties. Previous studies have also shown that RH induced hepatotoxicity, but the mechanisms of the adverse effect remain unknown. The major objective of the present study was to study the metabolic pathways of RH in order to identify potential reactive metabolites. One mono-hydroxylation metabolite (M1) was detected in urine and bile of rats given RH...
January 10, 2018: Chemico-biological Interactions
Munirah Ahmad, Shazlan-Noor Suhaimi, Tai-Lin Chu, Norazlin Abdul Aziz, Noor-Kaslina Mohd Kornain, D S Samiulla, Kwok-Wai Lo, Chew-Hee Ng, Alan Soo-Beng Khoo
Copper(II) ternary complex, [Cu(phen)(C-dmg)(H2O)]NO3 was evaluated against a panel of cell lines, tested for in vivo efficacy in nasopharyngeal carcinoma xenograft models as well as for toxicity in NOD scid gamma mice. The Cu(II) complex displayed broad spectrum cytotoxicity against multiple cancer types, including lung, colon, central nervous system, melanoma, ovarian, and prostate cancer cell lines in the NCI-60 panel. The Cu(II) complex did not cause significant induction of cytochrome P450 (CYP) 3A and 1A enzymes but moderately inhibited CYP isoforms 1A2, 2C9, 2C19, 2D6, 2B6, 2C8 and 3A4...
2018: PloS One
Yi-An Bi, Sumathy Mathialagan, Laurie Tylaska, Myra Fu, Julie Keefer, Anna Vildhede, Chester Costales, A David Rodrigues, Manthena Varma
Tolbutamide is primarily metabolized by cytochrome P450 (CYP)2C9, and thus, frequently applied as a clinical probe substrate for CYP2C9 activity. However, there is a marked discrepancy in the in vitro-in vivo extrapolation of its metabolic clearance implying potential for additional clearance mechanisms. The goal of this study was to evaluate the role of hepatic uptake transport in the pharmacokinetics of tolbutamide and identify the molecular mechanism thereof. Transport studies using singly-transfected cells expressing six major hepatic uptake transporters showed that tolbutamide is a substrate to organic anion transporter (OAT)2 alone -- with transporter affinity (Km) of 19...
January 11, 2018: Journal of Pharmacology and Experimental Therapeutics
Ami R Zota, Susanna D Mitro, Joshua F Robinson, Emily G Hamilton, June-Soo Park, Emily Parry, R Thomas Zoeller, Tracey J Woodruff
BACKGROUND: Human fetal exposures to polybrominated diphenyl ethers (PBDEs) and their metabolites (OH-PBDEs) are unique from adults, and in combination with a different metabolic profile, may make fetal development more sensitive to adverse health outcomes from these exposures. However, we lack data to characterize human fetal PBDE exposures and the metabolic factors that can influence these exposures. OBJECTIVE: We examined differences between 2nd trimester maternal and fetal exposures to PBDEs and OH-PBDEs...
January 6, 2018: Environment International
Kensaku Kakimoto, Norie Murayama, Shigeo Takenaka, Haruna Nagayoshi, Young-Ran Lim, Vitchan Kim, Donghak Kim, Hiroshi Yamazaki, Masayuki Komori, F Peter Guengerich, Tsutomu Shimada
1. We previously reported that flavone and flavanone interact spectrally with cytochrome P450 (P450 or CYP) 2A6 and 2A13 and other human P450s and inhibit catalytic activities of these P450 enzymes. In this study, we studied abilities of CYP1A1, 1A2, 1B1, 2A6, 2A13, 2C9, and 3A4 to oxidize flavone and flavanone. 2. Human P450s oxidized flavone to 6- and 5-hydroxylated flavones, seven uncharacterized mono-hydroxylated flavones, and five di-hydroxylated flavones. CYP2A6 was most active in forming 6-hydroxy- and 5-hydroxyflavones and several mono- and di-hydroxylated products...
January 9, 2018: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
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