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https://www.readbyqxmd.com/read/28636871/pregnane-glycosides-from-cynanchum-menarandrense
#1
Michail Tsoukalas, Arianna Psichas, Frank Reimann, Fiona M Gribble, Annelise Lobstein, Aurélie Urbain
Five new pregnane-type steroidal glycosides, named menarandrosides A-E (1-2, 5-7) were isolated from the aerial parts of Cynanchum menarandrense, together with three known compounds, carumbelloside I (3), carumbelloside II (4), and pregnenolone-3-O-gentiobioside (8). Their structures were determined on the basis of spectroscopic analyses including NMR and mass spectrometry, reporting C-21 steroids glycosylated only by one or two glucose moieties. Compounds were then investigated for their potential to stimulate glucagon-like peptide-1 (GLP-1) secretion in intestinal cells; although none of the pure compounds had any influence, the fraction enriched in pregnanes exhibited a significant activity, suggesting a possible synergistic effect...
June 18, 2017: Steroids
https://www.readbyqxmd.com/read/28624525/regulation-of-hepatic-abcb4-and-cyp3a65-gene-expression-and-multidrug-multixenobiotic-resistance-mdr-mxr-functional-activity-in-the-model-teleost-danio-rerio-zebrafish
#2
Jeremy S Jackson, Christopher J Kennedy
Multidrug/multixenobiotic resistance (MDR/MXR) confers resistance to a diverse range of potentially toxic pharmaceuticals and environmental contaminants through a cellular response that involves the coordinated induction and activity of the ATP-binding cassette (ABC) transporter P-glycoprotein (P-gp) and the Phase I metabolizing enzyme cytochrome P450 3A (CYP3A). In mammals, ligand-mediated pregnane X receptor (PXR) transcriptional activity regulates the induction of P-gp and CYP3A; however, this mechanism has not been well-characterized in fish...
June 14, 2017: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
https://www.readbyqxmd.com/read/28599754/the-effects-of-sex-protein-receptors-and-sex-steroid-hormone-gene-polymorphisms-on-breast-cancer-risk
#3
REVIEW
Somayeh Jahandoost, Pourandokht Farhanghian, Sakineh Abbasi
Breast cancer is a common disease and a major cause of death among women throughout the world. Various genes are believed to be involved in the initiation and progression of the disease. Some polymorphisms of these genes increase susceptibility to breast cancer in particular ethnicities. This study used electronic literature search to review the effects of different sex steroid hormone gene polymorphisms on breast cancer risk. Our findings indicated that some polymorphisms in estrogen receptor alpha (ER-α), ER-β, progesterone receptor (PGR), pregnane X receptor (PXR), and cytochrome P450 enzymes (CYPs) affected breast cancer susceptibility, especially in African American women...
July 2017: Journal of the National Medical Association
https://www.readbyqxmd.com/read/28571685/activation-of-the-aryl-hydrocarbon-receptor-decreases-rifampicin-induced-cyp3a4-expression-in-primary-human-hepatocytes-and-heparg
#4
Martin Krøyer Rasmussen, Martine Daujat-Chavanieu, Sabine Gerbal-Chaloin
The role of the cross-talk between nuclear receptors in the regulation of Cytochrome P450 expression in the liver is well-documented. Most studies have focused on the cross-talk between the pregnane X receptor (PXR) and other receptors, such as the constitutive androstane receptor. However, cross-talk between PXRs and aryl hydrocarbon receptors (AhRs) has also been suggested, but reports regarding this cross-talk are conflicting. In the present study, we treated HepaRG and primary human hepatocytes (PHHs) with both a strong (TCDD) and weak (3-methylindole; 3MI) AhR activator to investigate their impact on PXR-regulated expression of CYP3A4...
May 29, 2017: Toxicology Letters
https://www.readbyqxmd.com/read/28561586/anti-inflammatory-12-20-epoxypregnane-and-11-12-seco-pregnane-glycosides-from-the-stems-of-hoya-kerrii
#5
Chonticha Seeka, Samran Prabpai, Palangpon Kongsaeree, Supinya Tewtrakul, Thitima Lhinhatrakool, Somyote Sutthivaiyakit
Five 12,20-epoxypregnane glycosides (1-3, 5, and 6) and two 11,12-seco-pregnane glycosides (4 and 7) with spirodilactone motifs, as well as spirodilactone cleavage products 8 and 9, were isolated from the stems of Hoya kerrii. The relative configurations of the three related skeletons were supported by ROESY experiments and X-ray crystallographic analyses. The isolates were evaluated for their anti-inflammatory activity based on the inhibition of NO production in RAW264.7 cells, and some showed IC50 values ranging from 12...
May 31, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28560400/altered-gene-expression-of-hepatic-cytochrome-p450-in-a-rat-model-of-intermittent-hypoxia-with-emphysema
#6
Hongzhi Yu, Hongxia Shao, Qi Wu, Xin Sun, Li Li, Kuan Li, Xue Li, Yu Li, Qiuyang Zhang, Junping Wu, Huaiyong Chen
Patients with respiratory overlap syndrome (OS), defined as concomitant chronic obstructive pulmonary disease and obstructive sleep apnea syndrome, may exhibit an increased blood concentration of ingested drugs. This poor elimination of drugs is primarily attributed to downregulated gene expression of the drug‑metabolizing cytochrome P450 enzymes (CYPs) in the liver. However, the underlying mechanisms of the decreased expression of CYPs in OS are poorly understood. In order to address this, a rat model of intermittent hypoxia with emphysema was evaluated in the present study, by analyzing liver gene expression using the reverse transcription‑quantitative polymerase chain reaction...
July 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28558634/differential-regulation-of-cyp3a4-and-cyp3a5-and-its-implication-in-drug-discovery
#7
Ogheneochukome Lolodi, Yue-Ming Wang, William C Wright, Taosheng Chen
Cancer cells use several mechanisms to resist the cytotoxic effects of drugs, resulting in tumor progression and invasion. One such mechanism capitalizes on the body's natural defense against xenobiotics. Recent reports indicate that components of the xenobiotic response system are upregulated in some diseases, including many cancers. Such components include the pregnane X receptor and the cytochrome P450 3A4 and 3A5 enzymes. Intense research is ongoing to understand the functional ramifications of aberrant expression of these components in diseased states with the goal of designing novel drugs that can selectively target them...
May 30, 2017: Current Drug Metabolism
https://www.readbyqxmd.com/read/28546421/statins-attenuate-activation-of-the-nlrp3-inflammasome-by-oxidized-ldl-or-tnf-%C3%AE-in-vascular-endothelial-cells-through-a-pxr-dependent-mechanism
#8
Shaolan Wang, Xinya Xie, Ting Lei, Kang Zhang, Baochang Lai, Zihui Zhang, Youfei Guan, Guangmei Mao, Lei Xiao, Nanping Wang
Excessive activation of the NLRP3 inflammasome is implicated in cardiovascular diseases. Statins exert an anti-inflammatory effect independent of their cholesterol lowering effect. This study investigated the potential role of statins in the activation of the NLRP3 inflammasome in endothelial cells (ECs). Western blotting and qRT-PCR showed that oxidized-LDL (oxLDL) or tumor necrosis factor alpha (TNFα) activated the NLRP3 inflammasome in ECs. Simvastatin or mevastatin significantly suppressed the effects of oxLDL or TNFα...
May 25, 2017: Molecular Pharmacology
https://www.readbyqxmd.com/read/28546420/alterations-of-histone-modifications-contribute-to-pregnane-x-receptor-mediated-induction-of-cyp3a4-by-rifampicin
#9
Liang Yan, Yiting Wang, Jingyang Liu, Yali Nie, Xiaobo Zhong, Quancheng Kan, Lirong Zhang
Cytochrome P450 3A4 (CYP3A4) is one of the major drug-metabolizing enzymes in human and is responsible for the metabolism of 60% of the clinically used drugs. Many drugs are able to induce the expression of CYP3A4, which usually causes drug-drug interactions and adverse drug reactions. This study aims to explore the role of histone modifications in rifampicin-induced expression of CYP3A4 in LS174T cells. We found that the induction of CYP3A4 mRNA by rifampicin in LS174T cells was associated with increased levels of histone H3 lysine 4 trimethylation (H3K4me3) and H3 acetylation and a decreased level of histone H3 lysine 27 trimethylation (H3K27me3) in the CYP3A4 promoter...
May 25, 2017: Molecular Pharmacology
https://www.readbyqxmd.com/read/28546081/targeting-nuclear-receptors-for-the-treatment-of-fatty-liver-disease
#10
REVIEW
Naoki Tanaka, Toshifumi Aoyama, Shioko Kimura, Frank J Gonzalez
Ligand-activated nuclear receptors, including peroxisome proliferator-activated receptor alpha (PPARα), pregnane X receptor, and constitutive androstane receptor, were first identified as key regulators of the responses against chemical toxicants. However, numerous studies using mouse disease models and human samples have revealed critical roles for these receptors and others, such as PPARβ/δ, PPARγ, farnesoid X receptor (FXR), and liver X receptor (LXR), in maintaining nutrient/energy homeostasis in part through modulation of the gut-liver-adipose axis...
May 23, 2017: Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/28545240/14-15-secopregnane-type-glycosides-with-5%C3%AE-9%C3%AE-peroxy-and-%C3%AE-6-8-14-diene-linkages-from-the-roots-of-cynanchum-stauntonii
#11
An-Jun Deng, Jin-Qian Yu, Zhi-Hong Li, Lin Ma, Zhi-Hui Zhang, Hai-Lin Qin
Three new 14,15-secopregnane-type glycosides, stauntosides UA, UA₁, and UA₂, were isolated from the roots of Cynanchum stauntonii. The three compounds share the first reported and same basic structural features of 3β-hydroxy-14:16,15:20,18:20-triepoxy-5α:9α-peroxy-14,15-secopregnane-6,8(14)-diene named as stauntogenin G as the aglycones. The structures of the new compounds were characterized on the basis of extensive spectroscopic analyses, mainly 1D and 2D NMR and MS methods and chemical analysis. The isolation and identification of the new compounds graced the structural diversity of pregnane-type steroids from C...
May 23, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28534176/functions-of-pregnane-x-receptor-in-self-detoxification
#12
REVIEW
Liuqin He, Xihong Zhou, Niu Huang, Huan Li, Tiejun Li, Kang Yao, Yanan Tian, Chien-An Andy Hu, Yulong Yin
Pregnane X receptor (PXR, NR1I2), a member of the nuclear receptor superfamily, is a crucial regulator of nutrient metabolism and metabolic detoxification such as metabolic syndrome, xenobiotic metabolism, inflammatory responses, glucose, cholesterol and lipid metabolism, and endocrine homeostasis. Notably, much experimental and clinical evidence show that PXR senses xenobiotics and triggers the detoxification response to prevent diseases such as diabetes, obesity, intestinal inflammatory diseases and liver fibrosis...
May 22, 2017: Amino Acids
https://www.readbyqxmd.com/read/28506585/c21-steroidal-pregnane-sapogenins-and-their-derivatives-as-anti-inflammatory-agents
#13
Lie-Jun Huang, Shao-Ru Chen, Chun-Mao Yuan, Wei Gu, Bao-Jian Guo, Yi-Tao Wang, Ying Wang, Xiao-Jiang Hao
During the screening of natural anti-inflammatory agent, we identified some C21-steroidal pregnane sapogenins or the derivatives to inhibit TLR2, TLR3, and TLR4-initiatedinflammatory responses respectively. Treatment with active compounds 10, 2j and 3p failed to impact tumor necrosis factor-α (TNF-α) induced nucleus translocation of NF-κB p65 subunit. However, these compounds regulated distinct canonical or non-canonical NF-κB family members. Ectopic expression of TNF receptor associated factor 6 (TRAF6) abrogated the inhibitory activity of the compounds on production of pro-inflammatory cytokines downstream of TLR4...
July 1, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28501193/immunoaffinity-chromatography-combined-with-tandem-mass-spectrometry-a-new-tool-for-the-selective-capture-and-analysis-of-brassinosteroid-plant-hormones
#14
Jana Oklestkova, Danuše Tarkowská, Luděk Eyer, Tomáš Elbert, Aleš Marek, Zora Smržová, Ondřej Novák, Milan Fránek, Vladimir N Zhabinskii, Miroslav Strnad
Brassinosteroids (BRs) are plant-specific steroid hormones that play essential roles in the regulation of many important physiological processes in plant life. Their extremely low concentrations (~pmoles/g FW) in plant tissue and huge differences in polarity of individual members within the BR family hamper their detection and quantification. To address this problem, an immunoaffinity sorbent with broad specificity and high capacity for different BR metabolites containing a monoclonal antibody (mAb) against a BR spacer (20S)-2α,3α-dihydroxy-7-oxa-7α-homo-5α-pregnane-6-one-20 carboxylic acid (BR4812) was used for the rapid and highly selective isolation of endogenous BRs containing a 2α,3α-diol in ring A from minute plant samples...
August 1, 2017: Talanta
https://www.readbyqxmd.com/read/28496040/induction-of-human-cytochrome-p450-3a-enzymes-in-cultured-placental-cells-by-thalidomide-and-relevance-to-bioactivation-and-toxicity
#15
Norie Murayama, Yasuhiro Kazuki, Daisuke Satoh, Kazuya Arata, Tasuku Harada, Norio Shibata, F Peter Guengerich, Hiroshi Yamazaki
Evidence has been presented for auto-induced human cytochrome P450 3A enzyme involvement in the teratogenicity and clinical outcome of thalidomide due to oxidation to 5-hydroxythalidomide and subsequent metabolic activation in livers. In this study, more relevant human placenta preparations and placental BeWo cells showed low but detectable P450 3A4/5 mRNA expression and drug oxidation activities. Human placental microsomal fractions from three subjects showed detectable midazolam 1´- and 4-hydroxylation and thalidomide 5-hydroxylation activities...
2017: Journal of Toxicological Sciences
https://www.readbyqxmd.com/read/28480737/pregnane-steroids-from-the-vietnamese-octocoral-carijoa-riisei
#16
Nam Nguyen Hoai, Huong Nguyen Thi, Hanh Tran Thi Hong, Thanh Nguyen Van, Cuong Nguyen Xuan, Thung Do Cong, Kiem Phan Van, Minh Chau Van
Six pregnane steroids including one new compound namely 15β-hydroxypregna-4,20-dien-3-one (1), were isolated and structurally elucidated from the octocoral Carijoa riisei. The cytotoxic activity against a panel of eight human cancer cell lines of isolated compounds was also evaluated by SRB method. As the results, 18-acetoxypregna-1,4,20-trien-3-one (5) showed significant cytotoxicity against all the tested cell lines with the IC50 values from 22.29 ± 1.47 to 48.73 ± 3.93 μM, whereas 15β-acetoxypregna-1,4,20-trien-3-one (3) and 20R-acetoxypregna-1,4-dien-3-one (6) only exhibited weak effect on KB cell line with IC50 values of 93...
May 7, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28470937/endothelial-cell-derived-matrix-promotes-the-metabolic-functional-maturation-of-hepatocyte-via-integrin-src-signalling
#17
Xinyue Guo, Weihong Li, Minghui Ma, Xin Lu, Haiyan Zhang
The extracellular matrix (ECM) microenvironment is involved in the regulation of hepatocyte phenotype and function. Recently, the cell-derived extracellular matrix has been proposed to represent the bioactive and biocompatible materials of the native ECM. Here, we show that the endothelial cell-derived matrix (EC matrix) promotes the metabolic maturation of human adipose stem cell-derived hepatocyte-like cells (hASC-HLCs) through the activation of the transcription factor forkhead box protein A2 (FOXA2) and the nuclear receptors hepatocyte nuclear factor 4 alpha (HNF4α) and pregnane X receptor (PXR)...
May 4, 2017: Journal of Cellular and Molecular Medicine
https://www.readbyqxmd.com/read/28467654/sterol-regulatory-element-binding-protein-1c-knockout-mice-show-altered-neuroactive-steroid-levels-in-sciatic-nerve
#18
Nico Mitro, Gaia Cermenati, Matteo Audano, Silvia Giatti, Marzia Pesaresi, Silvia Pedretti, Roberto Spezzano, Donatella Caruso, Roberto Cosimo Melcangi
Neuroactive steroid levels are altered in several experimental models of peripheral neuropathy, and on this basis, they have been proposed as protective agents. For the first time, the levels of these molecules were here assessed in sterol regulatory-binding protein-1c (SREBP-1c) knock-out (KO) male mice (i.e., an experimental model of peripheral neuropathy) and compared with observations in wild type animals. The levels of neuroactive steroids have been evaluated by liquid chromatography tandem mass spectrometry in plasma and sciatic nerve at two and ten months of age and these analyses were implemented analyzing the gene expression of crucial steroidogenic enzymes in sciatic nerve...
May 3, 2017: Journal of Neurochemistry
https://www.readbyqxmd.com/read/28456553/an-unusual-spinaceamine-bearing-pregnane-from-a-soft-coral-scleronephthya-sp-inhibits-the-migration-of-tumor-cells
#19
Wei Cheng, Zhen Liu, Yang Yu, Leen van Ofwegen, Peter Proksch, Siwang Yu, Wenhan Lin
An unprecedented spinaceamine-bearing pregnane namely scleronine (1) was isolated from a Chinese soft coral Scleronephthya sp. Its structure was determined on the basis of 1D and 2D NMR spectroscopic analyses in association with the HRESIMS data, while the absolute configurations were deduced by the single-crystal X-ray diffraction analysis. In addition, a dehydrogenated analogue (3) was synthesized through six steps with pregna-1,20-dien-3-one (2) as a precursor. The significantly inhibitory effects of 1 and 3 against the migration of tumor cells A549 and B16 accompanying the down-regulation of key genes (TGFβ, TNFα, IL-1β, and IL-6) were observed...
June 15, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28454188/metabolic-profiling-of-hoodia-chamomile-terminalia-species-and-evaluation-of-commercial-preparations-using-ultrahigh-performance-liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry
#20
Bharathi Avula, Yan-Hong Wang, Giorgis Isaac, Jimmy Yuk, Mark Wrona, Kate Yu, Ikhlas A Khan
Ultrahigh-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (UHPLC-QToF-MS) profiling was used for the identification of marker compounds and generation of metabolic patterns that could be interrogated using chemometric modeling software. UHPLC-QToF-MS was used to generate comprehensive fingerprints of three botanicals (Hoodia, Terminalia, and chamomile), each having different classes of compounds. Detection of a broad range of ions was carried out in full scan mode in both positive and negative modes over the range m/z 100-1700 using high-resolution mass spectrometry...
April 28, 2017: Planta Medica
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