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https://www.readbyqxmd.com/read/28194454/in-vitro-genotoxicity-of-carcinogenic-asarone-isomers
#1
S Haupenthal, K Berg, M Gründken, S Vallicotti, M Hemgesberg, K Sak, D Schrenk, M Esselen
The present study focused on genotoxic properties of the carcinogenic phenylpropanoids α-asarone and β-asarone, which are found in several herbs and spices, such as Acorus calamus or Acorus gramineus. Cytotoxic and genotoxic effects were determined in human liver carinoma HepG2 cells, in hamster lung fibroblast V79 cells and in human cytochrome P450 1A2 and human sulfotransferase 1C2 transfected V79 cells (tV79). The Alamar blue assay was used to measure cytotoxicity of both isomers prior to the identification of DNA damaging properties by single cell gel electrophoresis (comet assay)...
February 14, 2017: Food & Function
https://www.readbyqxmd.com/read/28192119/leflunomide-induces-nad-p-h-quinone-dehydrogenase-1-enzyme-via-the-aryl-hydrocarbon-receptor-in-neonatal-mice
#2
Amrit Kumar Shrestha, Ananddeep Patel, Renuka T Menon, Weiwu Jiang, Lihua Wang, Bhagavatula Moorthy, Binoy Shivanna
Aryl hydrocarbon receptor (AhR) has been increasingly recognized to play a crucial role in normal physiological homeostasis. Additionally, disrupted AhR signaling leads to several pathological states in the lung and liver. AhR activation transcriptionally induces detoxifying enzymes such as cytochrome P450 (CYP) 1A and NAD(P)H quinone dehydrogenase 1 (NQO1). The toxicity profiles of the classical AhR ligands such as 3-methylcholanthrene and dioxins limit their use as a therapeutic agent in humans. Hence, there is a need to identify nontoxic AhR ligands to develop AhR as a clinically relevant druggable target...
February 10, 2017: Biochemical and Biophysical Research Communications
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
#3
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/28111763/cytochrome-p450-reaction-phenotyping-and-inhibition-and-induction-studies-of-pinostrobin-in-human-liver-microsomes-and-hepatocytes
#4
Shengnan Tan, Zhimin Dong, Jiashuo Zhang, Thomas Efferth, Yujie Fu, Xin Hua
Pinostrobin (PI, 5-hydroxy-7-methoxyflavanone) is a natural flavonoid known for its rich pharmacological activities. The objective of this study was to identify the human liver cytochrome P450 (CYP450) isoenzymes involved in the metabolism of PI. A single hydoxylated metabolite was obtained from PI after an incubation with pooled human liver microsomes (HLMs). The relative contributions of different CYP450s were evaluated using CYP450-selective inhibitors in HLMs and recombinant human CYP450 enzymes, and the results revealed the major involvement of CYP1A2, CYP2C9 and CYP2E1 in PI metabolism...
November 7, 2016: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28086769/effect-of-ginseng-extract-on-the-tgf-%C3%AE-1-signaling-pathway-in-ccl4-induced-liver-fibrosis-in-rats
#5
Mohamed M Hafez, Sherifa S Hamed, Manal F El-Khadragy, Zeinab K Hassan, Salim S Al Rejaie, Mohamed M Sayed-Ahmed, Naif O Al-Harbi, Khalid A Al-Hosaini, Mohamed M Al-Harbi, Ali R Alhoshani, Othman A Al-Shabanah, Shakir Dekhal Alsharari
BACKGROUND: Liver diseases are major global health problems. Ginseng extract has antioxidant, immune-modulatory and anti-inflammatory activities. This study investigated the effect of ginseng extract on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. METHODS: Male Wistar rats were divided into four groups: control group, ginseng group, CCl4 group and CCl4 + ginseng group. Liver injury was induced by the intraperitoneal (I.P) injection of 3 ml/kg CCl4 (30% in olive oil) weekly for 8 weeks...
January 13, 2017: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/28078726/dissecting-the-cytochrome-p450-1a2-and-3a4-mediated-metabolism-of-aflatoxin-b1-in-ligand-and-protein-contributions
#6
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
#7
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/28056947/triptolide-induces-hepatotoxicity-via-inhibition-of-cyp450s-in-rat-liver-microsomes
#8
Yan Lu, Tong Xie, Yajie Zhang, Fuqiong Zhou, Jie Ruan, Weina Zhu, Huaxu Zhu, Zhe Feng, Xueping Zhou
BACKGROUND: Triptolide (TP), an active constituent of Tripterygium wilfordii, possesses numerous pharmacological activities. However, its effects on cytochrome P450 enzymes (CYP450s) in rats remain unexplored. METHODS: In this study, the effects of triptolide on the six main CYP450 isoforms (1A2, 2C9, 2C19, 2D6, 2E1, and 3A) were investigated both in vivo and in vitro. We monitored the body weight, survival proportions, liver index, changes in pathology, and biochemical index upon TP administration, in vivo...
January 5, 2017: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/28000546/ortho-methylarylamines-as-time-dependent-inhibitors-of-cytochrome-p450-1a1-enzyme
#9
Jayalakshmi Sridhar, Jiawang Liu, Rajesh Komati, Richard Schroeder, Quan Jiang, Phan Tram, Kevin Riley, Maryam Foroozesh
Members of the cytochrome P450 1A family metabolize many procarcinogens such as polycyclic aromatic hydrocarbons and heterocyclic amines. Inactivation of these enzymes is prerequisite for cancer prevention and treatment in certain cases. Mechanism-based inhibition (time and co-factor dependent) is an effective method for the inactivation of these enzymes. Our recent study on emodin analogs revealed an anthraquinone with ortho-methylarylamine moiety that exhibited time-dependent inhibition of P450 enzymes 1A1 and 1A2...
December 20, 2016: Drug Metabolism Letters
https://www.readbyqxmd.com/read/27994733/identification-synthesis-and-biological-evaluation-of-the-major-human-metabolite-of-nlrp3-inflammasome-inhibitor-mcc950
#10
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
https://www.readbyqxmd.com/read/27989148/chemical-reactivity-of-emodin-and-its-oxidative-metabolites-to-thiols
#11
Boyang Qin, Yang Xu, Jiaming Chen, Wenlin Huang, Ying Peng, Jiang Zheng
Polygonum multiflorum is an herbal medicine widely employed in China. Hepatotoxicity of the herbal medicine has been well documented, but the mechanisms of the toxicity remain unknown. Emodin (EM) is a major constituent of the herb and has been reported to be hepatotoxic. The main purpose of this study was to define the metabolic pathways of EM in order to characterize the potential reactive intermediates. EM was incubated with rat liver microsomes or human liver microsomes, followed by LC-MS/MS analysis to investigate the in vitro and in vivo metabolism of EM...
December 19, 2016: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/27982683/the-in-vivo-effects-of-adenine-induced-chronic-kidney-disease-on-some-renal-and-hepatic-function-and-cyp450-metabolizing-enzymes
#12
M Al Za'abi, A Shalaby, P Manoj, B H Ali
Adenine-induced model of chronic kidney disease (CKD) is a widely used model especially in studies testing novel nephroprotective agents. We investigated the effects of adenine-induced CKD in rats on the activities of some xenobiotic metabolizing enzymes in liver and kidneys, and on some in vivo indicators of drug metabolism (viz pentobarbitone sleeping time, and plasma concentration of theophylline 90 min post administration). CKD was induced by orally feeding adenine (0.25% w/w) for 35 days. Adenine induced all the characteristics of CKD, which was confirmed by biochemical and histological findings...
December 16, 2016: Physiological Research
https://www.readbyqxmd.com/read/27976871/metabolism-of-the-tobacco-carcinogen-2-amino-9h-pyrido-2-3-b-indole-a%C3%AE-c-in-primary-human-hepatocytes
#13
Medjda Bellamri, Ludovic Le Hegarat, Robert J Turesky, Sophie Langouët
2-Amino-9H-pyrido[2,3-b]indole (AαC) is the most abundant carcinogenic heterocyclic aromatic amine (HAA) formed in mainstream tobacco smoke. AαC is a liver carcinogen in rodents, but its carcinogenic potential in humans is not known. To obtain a better understanding of the genotoxicity of AαC in humans, we have investigated its metabolism and its ability to form DNA adducts in human hepatocytes. Primary human hepatocytes were treated with AαC at doses ranging from 0.1-50 μM, and the metabolites were characterized by ultra-performance LC/ion trap multistage mass spectrometry (UPLC/MS(n))...
December 15, 2016: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/27913846/potent-mutagenicity-of-some-non-planar-tri-and-tetrachlorinated-biphenyls-in-mammalian-cells-human-cyp2e1-being-a-major-activating-enzyme
#14
Yungang Liu, Keqi Hu, Hansi Jia, Guifang Jin, Hansruedi Glatt, Hao Jiang
Polychlorinated biphenyls (PCBs) have been classified as human carcinogens. Mutagenicity of lower chlorinated biphenyls as well as activation of transcription factors by some other congeners may contribute to the carcinogenicity of PCBs. Recently, we reported that human CYP2E1 activates mono- and dichlorobiphenyls to mutagens. However, mutagenicity of other PCBs and the involvement of other CYPs remained unknown. In this study, Chinese hamster V79-derived cell lines genetically engineered for expression of individual human CYP enzymes and a human hepatocyte (L-02) line endogenously expressing various CYPs were used to determine the activities of several tri- and tetrachlorobiphenyls to induce micronuclei and gene mutations...
December 2, 2016: Archives of Toxicology
https://www.readbyqxmd.com/read/27872784/ciprofloxacin-and-clozapine-a-potentially-fatal-but-underappreciated-interaction
#15
Jonathan M Meyer, George Proctor, Michael A Cummings, Laura J Dardashti, Stephen M Stahl
Objective. Clozapine provides a 50%-60% response rate in refractory schizophrenia but has a narrow therapeutic index and is susceptible to pharmacokinetic interactions, particularly with strong inhibitors or inducers of cytochrome P450 (CYP) 1A2. Case Report. We report the case of a 28-year-old nonsmoking female with intellectual disability who was maintained for 3 years on clozapine 100 mg orally twice daily. The patient was treated for presumptive urinary tract infection with ciprofloxacin 500 mg orally twice daily and two days later collapsed and died despite resuscitation efforts...
2016: Case Reports in Psychiatry
https://www.readbyqxmd.com/read/27872699/the-effects-of-fenvalerate-on-hepatic-and-cerebral-xenobiotic-metabolizing-enzymes-in-selenium-and-or-iodine-deficient-rats
#16
Aydan Caglayan, Belma Kocer-Gumusel, Pinar Erkekoglu, Filiz Hincal
OBJECTIVES: Particularly in developing countries, selenium and/or iodine deficiencies are encountered and use of pesticides in agriculture are not well-controlled. Fenvalerate is a pyrethroid insectide used in agriculture and has applications against a wide range of pests. This study was designed to evaluate the effects of fenvalerate on hepatic and cerebral xenobiotic metabolizing enzyme activities in the presence of iodine and/or selenium deficiency on a rat model. MATERIALS AND METHODS: Iodine and/or selenium deficiency was induced by feeding three-week-old Wistar rats with a diet containing <0...
October 2016: Iranian Journal of Basic Medical Sciences
https://www.readbyqxmd.com/read/27842484/strong-induction-of-cytochrome-p450-1a-3a-but-not-p450-2b-in-cultured-hepatocytes-from-common-marmosets-and-cynomolgus-monkeys-by-typical-human-p450-inducing-agents
#17
Shotaro Uehara, Yasuhiro Uno, Takako Suzuki, Takashi Inoue, Masahiro Utoh, Erika Sasaki, Hiroshi Yamazaki
BACKGROUND: Common marmosets (Callithrix jacchus) and cynomolgus monkeys (Macaca fascicularis) are used as non-human primate models in preclinical studies for drug development. OBJECTIVE: The assessment of P450 induction in hepatocytes from marmosets and cynomolgus monkeys was performed using typical P450 inducers. METHODS: Induction of cytochrome P450 1-4 family enzymes was analyzed in two lots of cultured hepatocytes from common marmosets and cynomolgus monkeys after 24-h treatment with typical human P450 inducing agents by real-time reverse transcription-polymerase chain reaction...
November 14, 2016: Drug Metabolism Letters
https://www.readbyqxmd.com/read/27819189/inhibitory-effects-of-curculigoside-on-human-liver-cytochrome-p450-enzymes
#18
Jixiao Lang, Wei Li, Jingming Zhao, Kaiyou Wang, Dexi Chen
1. Curculigoside possesses numerous pharmacological activities, and however, little data available for the effects of curculigoside on the activity of human liver cytochrome P450 (CYP) enzymes. 2. This study investigates the inhibitory effects of curculigoside on the main human liver CYP isoforms. In this study, the inhibitory effects of curculigoside on the eight human liver CYP isoforms 1A2, 2A6, 2E1, 2D6, 2C9, 2C19, 2C8, and 3A4 were investigated in human liver microsomes. 3. The results indicated that curculigoside could inhibit the activity of CYP1A2, CYP2C8, and CYP3A4, with IC50 values of 15...
November 5, 2016: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
https://www.readbyqxmd.com/read/27799384/severe-asthma-exists-despite-suppressed-tissue-inflammation-findings-of-the-u-biopred-study
#19
Susan J Wilson, Jonathan A Ward, Ana R Sousa, Julie Corfield, Aruna T Bansal, Bertrand De Meulder, Diane Lefaudeux, Charles Auffray, Matthew J Loza, Frederic Baribaud, Neil Fitch, Peter J Sterk, Kian Fan Chung, David Gibeon, Kai Sun, Yi-Ke Guo, Ian Adcock, Ratko Djukanovic, Barbro Dahlen, Pascal Chanez, Dominick Shaw, Norbert Krug, Jens Hohlfeld, Thomas Sandström, Peter H Howarth
The U-BIOPRED study is a multicentre European study aimed at a better understanding of severe asthma. It included three steroid-treated adult asthma groups (severe nonsmokers (SAn group), severe current/ex-smokers (SAs/ex group) and those with mild-moderate disease (MMA group)) and healthy controls (HC group). The aim of this cross-sectional, bronchoscopy substudy was to compare bronchial immunopathology between these groups.In 158 participants, bronchial biopsies and bronchial epithelial brushings were collected for immunopathologic and transcriptomic analysis...
November 2016: European Respiratory Journal: Official Journal of the European Society for Clinical Respiratory Physiology
https://www.readbyqxmd.com/read/27783977/targeting-the-entry-region-of-hsp90-s-atp-binding-pocket-with-a-novel-6-7-dihydrothieno-3-2-c-pyridin-5-4h-yl-amide
#20
Ju Hui Jeong, Yong Jin Oh, Yunmee Lho, Sun You Park, Kwang-Hyeon Liu, Eunyoung Ha, Young Ho Seo
The molecular chaperone Hsp90 plays an important role in cancer cell survival and proliferation by regulating the maturation and stabilization of numerous oncogenic proteins. Due to its potential to simultaneously disable multiple signaling pathways, Hsp90 has emerged as an attractive therapeutic target for cancer treatment. In this study, the design, synthesis, and biological evaluation of a series of Hsp90 inhibitors are described. Among the synthetic compounds, 6,7-dihydrothieno [3,2-c]pyridin-5(4H)-yl amide 19 exhibits a remarkable binding affinity to the N-terminus of Hsp90 in a fluorescence polarization (FP) binding assay (IC50 = 50...
November 29, 2016: European Journal of Medicinal Chemistry
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