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Sample records for active metabolites formed

  1. Formed and preformed metabolites: facts and comparisons.

    PubMed

    Pang, K Sandy; Morris, Marilyn E; Sun, Huadong

    2008-10-01

    The administration of metabolites arising from new drug entities is often employed in drug discovery to investigate their associated toxicity. It is expected that administration of metabolites can predict the exposure of metabolites originating from the administration of precursor drug. Whether exact and meaningful information can be obtained from this has been a topic of debate. This communication summarizes observations and theoretical relationships based on physiological modelling for the liver, kidney and intestine, three major eliminating organs/tissues. Theoretical solutions based on physiological modelling of organs were solved, and the results suggest that deviations are expected. Here, examples of metabolite kinetics observed mostly in perfused organs that did not match predictions are provided. For the liver, discrepancies in fate between formed and preformed metabolites may be explained by the heterogeneity of enzymes, the presence of membrane barriers and whether transporters are involved. For the kidney, differences have been attributed to glomerular filtration of the preformed but not the formed metabolite. For the intestine, the complexity of segregated flows to the enterocyte and serosal layers and differences in metabolism due to the route of administration are addressed. Administration of the metabolite may or may not directly reflect the toxicity associated with drug use. However, kinetic data on the preformed metabolite will be extremely useful to develop a sound model for modelling and simulations; in-vitro evidence on metabolite handling at the target organ is also paramount. Subsequent modelling and simulation of metabolite data arising from a combined model based on both drug and preformed metabolite data are needed to improve predictions on the behaviours of formed metabolites. PMID:18812018

  2. Metabolites and DNA adduct formation from flavoenzyme-activated porfiromycin.

    PubMed

    Pan, S S; Iracki, T

    1988-08-01

    Porfiromycin was reductively metabolized by NADPH cytochrome P-450 reductase and xanthine oxidase under anaerobic conditions. The production of metabolites varied with the pH and the contents of the reaction buffer. In Tris buffer, two major metabolites were produced at pH 7.5 and above, whereas one major metabolite was produced at pH 6.5. The three major metabolites were separated and isolated by HPLC. Identification by californium-252 plasma desorption mass spectrometry showed that the two major metabolites from pH 7.5 were (trans) and (cis)-forms of 7-amino-1-hydroxyl-2-methylaminomitosene and the major metabolite from pH 6.5 was 7-amino-2-methylaminomitosene. All three major metabolites showed substitutions at the C-1 position. DNA was alkylated readily by enzyme-activated porfiromycin. Digestion of porfiromycin-alkylated DNA by DNase, snake venom phosphodiesterase, and alkaline phosphatase resulted in an insoluble nuclease-resistant fraction and a soluble fraction. The nuclease-resistant fraction reflected a high content of cross-linked adducts. Upon HPLC analysis, the solubilized fraction contained two monofunctionally linked porfiromycin adducts and a possibly cross-linked dinucleotide. The major adduct was isolated by HPLC and identified by NMR, as N2-(2'-deoxyguanosyl)-7-amino-2-methylaminomitosene. The N2 position of deoxyguanosine appeared as the major monofunctional alkylating site for DNA alkylation by porfiromycin. Thus, mitomycin C and porfiromycin (which differs from mitomycin C only by the addition of a methyl group to the aziridine nitrogen) share the same enzymatic activating mechanism that leads to the formation of the same types of metabolites and the same specificity of DNA alkylation. PMID:3412325

  3. Isolation and identification of metabolites of porfiromycin formed in the presence of a rat liver preparation.

    PubMed

    Lang, W; Mao, J; Wang, Q; Niu, C; Doyle, T W; Almassian, B

    2000-02-01

    The isolation and identification of the major metabolites of porfiromycin formed in the presence of a rat liver preparation under aerobic conditions were performed with high-performance liquid chromatography and electrospray ionization mass spectrometry. Porfiromycin was extensively metabolized by the rat liver preparation in an aqueous 0.1 M potassium phosphate buffer (pH 7.4) containing an NADPH generating system at 37 degrees C. A total of eight metabolites was identified as mitosene analogs. Of these, three primary metabolites are 2-methylamino-7-aminomitosene, 1,2-cis and 1,2-trans-1-hydroxy-2-methylamino-7-aminomitosene, which are consistent with those previously observed in hypoxia using purified rat liver NADPH-cytochrome c reductase. Interestingly, 2-methylamino-7-aminomitosene is a reactive metabolite, which undergoes further activation at the C-10 position by the loss of carbamic acid and then links with the 7-amino group of the primary metabolites to yield two dimeric adducts. In addition, three phosphate adducts, 10-decarbamoyl-2-methylamino-7-aminomitosene-10-phosphate, 1,2-cis and 1,2-trans-2-methylamino-7-aminomitosene-1-phosphate, were also identified in the incubation system. The configurations of the diastereoisomeric metabolites were determined with (1)HNMR and phosphatase digestion. On the basis of the metabolite profile, we propose in vitro metabolic pathways for porfiromycin. The findings provide direct evidence for understanding the reactive nature and hepatic metabolism of the drug currently in phase III clinical trials. PMID:10688748

  4. Synthesis of the alkylated active metabolite of tipidogrel.

    PubMed

    Zhi, Shuang; Xia, Guangping; Liu, Ying; Tao, Zunwei; Chen, Ligong; Liu, Dengke

    2015-04-15

    Tipidogrel (3), an effective anti-platelet drug candidate working by irreversibly inhibiting P2Y12 receptor, holds great promise in overcoming clopidogrel resistance and increasing bioavailability. As a prodrug like other thienopyridines, it metabolizes through thiophene ring opening to form active metabolites 3a and 3b, nevertheless they are easily to form disulfide bond. Derivatization of 3a and 3b via alkylation with MPBr can prevent disulfide conjugation and ensure reliable pharmacokinetic results. Thus, in order to support its pre-clinical studies on efficiencies in the formation of tipidogrel active metabolites, 13a and 13b were synthesized via seven steps of chemosynthesis and incubation with MPBr in rat plasma in vitro. The resulting crude productions were purified by semi-preparative HPLC to give Z configuration 13a and E configuration 13b. In LC-MS/MS spectra, they showed identical fragmentation pattern and retention time with M-13a and M-13b, the MPBr-derivatives of active metabolites of tipidogrel in rats. Thus, 13a and 13b were the anticipated alkylated active metabolite of tipidogrel. In addition, in the nucleophilic substitution of thioacetate with compound 11, besides the anticipated compounds 12a and 12b, their isomers compounds 12c and 12d were detected, whose structures were confirmed and the corresponding mechanism was presented. PMID:25801935

  5. Biologically Active Metabolites Synthesized by Microalgae

    PubMed Central

    de Morais, Michele Greque; Vaz, Bruna da Silva; de Morais, Etiele Greque; Costa, Jorge Alberto Vieira

    2015-01-01

    Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences. PMID:26339647

  6. Antimycobacterial activity of lichen metabolites in vitro.

    PubMed

    Ingólfsdóttir, K; Chung, G A; Skúlason, V G; Gissurarson, S R; Vilhelmsdóttir, M

    1998-04-01

    Several compounds, whose structures represent the most common chemical classes of lichen metabolites, were screened for in vitro activity against Mycobacterium aurum, a non-pathogenic organism with a similar sensitivity profile to M. tuberculosis. Of the compounds tested, usnic acid from Cladonia arbuscula exhibited the highest activity with an MIC value of 32 microg/ml. Atranorin and lobaric acid, both isolated from Stereocaulon alpinum, salazinic acid from Parmelia saxatilis and protolichesterinic acid from Cetraria islandica all showed MIC values >/=125 microg/ml. PMID:9795033

  7. Natural Forms of Vitamin E and 13′-Carboxychromanol, a Long-Chain Vitamin E Metabolite, Inhibit Leukotriene Generation from Stimulated Neutrophils by Blocking Calcium Influx and Suppressing 5-Lipoxygenase Activity, Respectively

    PubMed Central

    Jiang, Ziying; Yin, Xinmin; Jiang, Qing

    2014-01-01

    Leukotrienes generated by 5-lipoxygenase (5-LOX)–catalyzed reaction are key regulators of inflammation. In ionophore-stimulated (A23187; 1–2.5 μM) human blood neutrophils or differentiated HL-60 cells, vitamin E forms differentially inhibited leukotriene B4 (LTB4) with an IC50 of 5–20 μM for γ-tocopherol, δ-tocopherol (δT), and γ-tocotrienol, but a much higher IC50 for α-tocopherol. 13′-Carboxychromanol, a long-chain metabolite of δT, suppressed neutrophil- and HL-60 cell-generated LTB4 with an IC50 of 4–7 μM and potently inhibited human recombinant 5-LOX activity with an IC50 of 0.5–1 μM. In contrast, vitamin E forms had no effect on human 5-LOX activity but impaired ionophore-induced intracellular calcium increase and calcium influx as well as the subsequent signaling including ERK1/2 phosphorylation and 5-LOX translocation from cytosol to the nucleus, a key event for 5-LOX activation. Further investigation showed that δT suppressed cytosolic Ca2+ increase and/or LTB4 formation triggered by ionophores, sphingosine 1-phosphate, and lysophosphatidic acid but not by fMLP or thapsigargin, whereas 13′-carboxychromanol decreased cellular production of LTB4 regardless of different stimuli, consistent with its strong inhibition of the 5-LOX activity. These observations suggest that δT does not likely affect fMLP receptor-mediated signaling or store depletion-induced calcium entry. Instead, we found that δT prevented ionophore-caused cytoplasmic membrane disruption, which may account for its blocking of calcium influx. These activities by vitamin E forms and long-chain carboxychromanol provide potential molecular bases for the differential anti-inflammatory effects of vitamin E forms in vivo. PMID:21169551

  8. Metabolite

    MedlinePlus

    A metabolite is any substance produced during metabolism (digestion or other bodily chemical processes). The term metabolite may also refer to the product that remains after a drug is broken down (metabolized) by the body.

  9. Antidotes for poisoning by alcohols that form toxic metabolites.

    PubMed

    McMartin, Kenneth; Jacobsen, Dag; Hovda, Knut Erik

    2016-03-01

    The alcohols, methanol, ethylene glycol and diethylene glycol, have many features in common, the most important of which is the fact that the compounds themselves are relatively non-toxic but are metabolized, initially by alcohol dehydrogenase, to various toxic intermediates. These compounds are readily available worldwide in commercial products as well as in homemade alcoholic beverages, both of which lead to most of the poisoning cases, from either unintentional or intentional ingestion. Although relatively infrequent in overall occurrence, poisonings by metabolically-toxic alcohols do unfortunately occur in outbreaks and can result in severe morbidity and mortality. These poisonings have traditionally been treated with ethanol since it competes for the active site of alcohol dehydrogenase and decreases the formation of toxic metabolites. Although ethanol can be effective in these poisonings, there are substantial practical problems with its use and so fomepizole, a potent competitive inhibitor of alcohol dehydrogenase, was developed for a hopefully better treatment for metabolically-toxic alcohol poisonings. Fomepizole has few side effects and is easy to use in practice and it may obviate the need for haemodialysis in some, but not all, patients. Hence, fomepizole has largely replaced ethanol as the toxic alcohol antidote in many countries. Nevertheless, ethanol remains an important alternative because access to fomepizole can be limited, the cost may appear excessive, or the physician may prefer ethanol due to experience. PMID:26551875

  10. ANALYSIS OF ARACHIDONIC ACID METABOLITE AND PLATELET ACTIVATING FACTOR PRODUCTION

    EPA Science Inventory

    Metabolites of arachidonic acid ("eicosanoids") and platelet activating factor are important bioactive lipids that may be involved in the pathobiological alterations in animals induced by pollutant exposure. nalysis of these substances in biological tissue and fluids is important...

  11. DHEA metabolites activate estrogen receptors alpha and beta

    PubMed Central

    Michael Miller, Kristy K.; Al-Rayyan, Numan; Ivanova, Margarita M.; Mattingly, Kathleen A.; Ripp, Sharon L.; Klinge, Carolyn M.; Prough, Russell A.

    2012-01-01

    Dehydroepiandrosterone (DHEA) levels were reported to associate with increased breast cancer risk in postmenopausal women, but some carcinogen-induced rat mammary tumor studies question this claim. The purpose of this study was to determine how DHEA and its metabolites affect estrogen receptors α or β (ERα or ERβ) -regulated gene transcription and cell proliferation. In transiently transfected HEK-293 cells, androstenediol, DHEA, and DHEA-S activated ERα. In ERβ transfected HepG2 cells, androstenedione, DHEA, androstenediol, and 7-oxo DHEA stimulated reporter activity. ER antagonists ICI 182,780 (fulvestrant) and 4-hydroxytamoxifen, general P450 inhibitor miconazole, and aromatase inhibitor exemestane inhibited activation by DHEA or metabolites in transfected cells. ERβ-selective antagonist R,R-THC (R,R-cis-diethyl tetrahydrochrysene) inhibited DHEA and DHEA metabolite transcriptional activity in ERβ-transfected cells. Expression of endogenous estrogen-regulated genes: pS2, progesterone receptor, cathepsin D1, and nuclear respiratory factor-1 was increased by DHEA and its metabolites in an ER-subtype, gene, and cell-specific manner. DHEA metabolites, but not DHEA, competed with 17β-estradiol for ERα and ERβ binding and stimulated MCF-7 cell proliferation, demonstrating that DHEA metabolites interact directly with ERα and ERβ in vitro, modulating estrogen target genes in vivo. PMID:23123738

  12. Identification of metabolites of the anabolic steroid methandienone formed by bovine hepatocytes in vitro.

    PubMed

    Hooijerink, D; Schilt, R; Hoogenboom, R; Huveneers-Oorsprong, M

    1998-12-01

    Monolayer cultures of bovine hepatocytes were used to investigate the biotransformation of methandienone in vitro. After incubation of bovine hepatocytes with methandienone, samples were taken at different times. The samples were treated with deconjugation enzymes and extracted with diethyl ether. The metabolites formed were converted to their trimethylsilylether derivatives. By using gas chromatography-mass spectrometry with electron impact and chemical ionisation, several metabolites were identified. After 24 h of incubation with bovine hepatocytes, 83% of the parent compound was converted to its metabolites. The major metabolite found was 6-beta-hydroxymethandienone with a yield of 24%. This compound was identified after comparison with an authentic sample of 6 beta-hydroxymethandienone, which was synthesized chemically. PMID:10435315

  13. Secondary Metabolites from Three Florida Sponges with Antidepressant Activity

    PubMed Central

    Kochanowska, Anna J.; Rao, Karumanchi V.; Childress, Suzanne; El-Alfy, Abir; Matsumoto, Rae R.; Kelly, Michelle; Stewart, Gina S.; Sufka, Kenneth J.; Hamann, Mark T.

    2016-01-01

    Brominated indole alkaloids are a common class of metabolites reported from sponges of the order Verongida. Herein we report the isolation, structure determination, and activity of metabolites from three Florida sponges, namely, Verongula rigida (order Verongida, family Aplysinidae), Smenospongia aurea, and S. cerebriformis (order Dictyoceratida, family Thorectidae). All three species were investigated chemically, revealing similarities in secondary metabolites. Brominated compounds, as well as sesquiterpene quinones and hydroquinones, were identified from both V. rigida and S. aurea despite their apparent taxonomic differences at the ordinal level. Similar metabolites found in these distinct sponge species of two different genera provide evidence for a microbial origin of the metabolites. Isolated compounds were evaluated in the Porsolt forced swim test (FST) and the chick anxiety–depression continuum model. Among the isolated compounds, 5,6-dibromo-N,N-dimethyltryptamine (1) exhibited significant antidepressant-like action in the rodent FST model, while 5-bromo-N,N-dimethyltryptamine (2) caused significant reduction of locomotor activity indicative of a potential sedative action. The current study provides ample evidence that marine natural products with the diversity of brominated marine alkaloids will provide potential leads for antidepressant and anxiolytic drugs. PMID:18217716

  14. Molecular complexes of cocaine, its active metabolites and some other stimulants with thiamine.

    PubMed

    Misra, A L; Vadlamani, N L

    1976-10-01

    Cocaine, its pharmacologically active metabolites, norcocaine benzoylnorecgonine, benzoylecgonine and other central nervous system stimulants e.g. dextrococaine, nicotine, caffeine and p-hydroxy norephedrine formed molecular complexes with thiamine. The possible implications of such an interaction are discussed. PMID:10608

  15. Metabolism of a highly selective gelatinase inhibitor generates active metabolite.

    PubMed

    Lee, Mijoon; Villegas-Estrada, Adriel; Celenza, Giuseppe; Boggess, Bill; Toth, Marta; Kreitinger, Gloria; Forbes, Christopher; Fridman, Rafael; Mobashery, Shahriar; Chang, Mayland

    2007-11-01

    (4-Phenoxyphenylsulfonyl)methylthiirane (inhibitor 1) is a highly selective inhibitor of gelatinases (matrix metalloproteinases 2 and 9), which is showing considerable promise in animal models for cancer and stroke. Despite demonstrated potent, selective, and effective inhibition of gelatinases both in vitro and in vivo, the compound is rapidly metabolized, implying that the likely activity in vivo is due to a metabolite rather than the compound itself. To this end, metabolism of inhibitor 1 was investigated in in vitro systems. Four metabolites were identified by LC/MS-MS and the structures of three of them were further validated by comparison with authentic synthetic samples. One metabolite, 4-(4-thiiranylmethanesulfonylphenoxy)phenol (compound 21), was generated by hydroxylation of the terminal phenyl group of 1. This compound was investigated in kinetics of inhibition of several matrix metalloproteinases. This metabolite was a more potent slow-binding inhibitor of gelatinases (matrix metalloproteinase-2 and matrix metalloproteinase-9) than the parent compound 1, but it also served as a slow-binding inhibitor of matrix metalloproteinase-14, the upstream activator of matrix metalloproteinase-2. PMID:17927722

  16. In Vivo-Formed versus Preformed Metabolite Kinetics of trans-Resveratrol-3-sulfate and trans-Resveratrol-3-glucuronide

    PubMed Central

    Sharan, Satish; Iwuchukwu, Otito F.; Canney, Daniel J.; Zimmerman, Cheryl L.

    2012-01-01

    Metabolites in safety testing have gained a lot of attention recently. Regulatory agencies have suggested that the kinetics of preformed and in vivo-formed metabolites are comparable. This subject has been a topic of debate. We have compared the kinetics of in vivo-formed with preformed metabolites. trans-3,5,4′-Trihydroxystilbene [trans-resveratrol (RES)] and its two major metabolites, resveratrol-3-sulfate (R3S) and resveratrol-3-glucuronide (R3G) were used as model substrates. The pharmacokinetics (PK) of R3S and R3G were characterized under two situations. First, the pharmacokinetics of R3S and R3G were characterized (in vivo-formed metabolite) after administration of RES. Then, synthetic R3S and R3G were administered (preformed metabolite) and their pharmacokinetics were characterized. PK models were developed to describe the data. A three-compartment model for RES, a two-compartment model for R3S (preformed), and an enterohepatic cycling model for R3G (preformed) was found to describe the data well. These three models were further combined to build a comprehensive PK model, which was used to perform simulations to predict in vivo-formed metabolite kinetics. Comparisons were made between in vivo-formed and preformed metabolite kinetics. Marked differences were observed in the kinetics of preformed and in vivo-formed metabolites. PMID:22807110

  17. Isoflavone metabolism in domestic cats (Felis catus): comparison of plasma metabolites detected after ingestion of two different dietary forms of genistein and daidzein.

    PubMed

    Whitehouse-Tedd, K M; Cave, N J; Ugarte, C E; Waldron, L A; Prasain, J K; Arabshahi, A; Barnes, S; Hendriks, W H; Thomas, D G

    2013-03-01

    Some felid diets contain isoflavones but the metabolic capacity of cats toward isoflavones is relatively unknown, despite the understanding that isoflavones have divergent biological potential according to their metabolite end products. The objective of this study was to determine the plasma metabolites detectable in domestic cats after exposure to 2 different dietary forms of isoflavones, either as a soy extract tablet (n = 6) or as part of a dietary matrix (n = 4). Serial blood samples were collected after isoflavone exposure to identify the plasma metabolites of each cat. Genistein was detected in its unconjugated form or as a monosulfate. Daidzein was detected as both a mono- and disulfate as well as in its unconjugated form. Other daidzein metabolites detected included equol mono- and disulfate, dihydrodaidzein, and O-desmethylangolensin. No β-glucuronide metabolites of either isoflavone were detected. Equol was produced in markedly fewer cats after ingestion of a soy extract tablet as a single oral bolus compared with cats consuming an isoflavone-containing diet. The detectable metabolites of the isoflavones, genistein and daidzein, in domestic cat plasma after dietary ingestion has been described in the present study for the first time. The metabolic capacity for isoflavones by domestic cats appears to be efficient, with only minimal proportions of the ingested amount detected in their unconjugated forms. This has implications for the potential of isoflavones to exert physiological activity in the domestic cat when consumed at concentrations representative of typical dietary intake. PMID:23307849

  18. Investigations of fungal secondary metabolites with potential anticancer activity.

    PubMed

    Balde, ElHadj Saidou; Andolfi, Anna; Bruyère, Céline; Cimmino, Alessio; Lamoral-Theys, Delphine; Vurro, Maurizio; Damme, Marc Van; Altomare, Claudio; Mathieu, Véronique; Kiss, Robert; Evidente, Antonio

    2010-05-28

    Fourteen metabolites, isolated from phytopathogenic and toxigenic fungi, were evaluated for their in vitro antigrowth activity for six distinct cancer cell lines, using the MTT colorimetric assay. Bislongiquinolide (1) and dihydrotrichodimerol (5), which belong to the bisorbicillinoid structural class, displayed significant growth inhibitory activity against the six cancer cell lines studied, while the remaining compounds displayed weak or no activity. The data show that 1 and 5 have similar growth inhibitory activities with respect to those cancer cell lines that display certain levels of resistance to pro-apoptotic stimuli or those that are sensitive to apoptosis. Quantitative videomicroscopy analysis revealed that 1 and 5 exert their antiproliferative effect through cytostatic and not cytotoxic activity. The preliminary results from the current study have stimulated further structure-activity investigations with respect to the growth inhibitory activity of compounds belonging to the bisorbicillinoid group. PMID:20415482

  19. Activity of Praziquantel Enantiomers and Main Metabolites against Schistosoma mansoni

    PubMed Central

    Meister, Isabel; Ingram-Sieber, Katrin; Cowan, Noemi; Todd, Matthew; Robertson, Murray N.; Meli, Claudia; Patra, Malay; Gasser, Gilles

    2014-01-01

    A racemic mixture of R and S enantiomers of praziquantel (PZQ) is currently the treatment of choice for schistosomiasis. Though the S enantiomer and the metabolites are presumed to contribute only a little to the activity of the drug, in-depth side-by-side studies are lacking. The aim of this study was to investigate the in vitro activities of PZQ and its main metabolites, namely, R- and S-cis- and R- and S-trans-4′-hydroxypraziquantel, against adult worms and newly transformed schistosomula (NTS). Additionally, we explored the in vivo activity and hepatic shift (i.e., the migration of the worms to the liver) produced by each PZQ enantiomer in mice. Fifty percent inhibitory concentrations of R-PZQ, S-PZQ, and R-trans- and R-cis-4′-hydroxypraziquantel of 0.02, 5.85, 4.08, and 2.42 μg/ml, respectively, for adult S. mansoni were determined in vitro. S-trans- and S-cis-4′-hydroxypraziquantel were not active at 100 μg/ml. These results are consistent with microcalorimetry data and studies with NTS. In vivo, single 400-mg/kg oral doses of R-PZQ and S-PZQ achieved worm burden reductions of 100 and 19%, respectively. Moreover, worms treated in vivo with S-PZQ displayed an only transient hepatic shift and returned to the mesenteric veins within 24 h. Our data confirm that R-PZQ is the main effector molecule, while S-PZQ and the metabolites do not play a significant role in the antischistosomal properties of PZQ. PMID:24982093

  20. Hsp90 Activity Modulation by Plant Secondary Metabolites.

    PubMed

    Dal Piaz, Fabrizio; Terracciano, Stefania; De Tommasi, Nunziatina; Braca, Alessandra

    2015-09-01

    Hsp90 is an evolutionarily conserved adenosine triphosphate-dependent molecular chaperone and is one of the most abundant proteins in the cells (1-3 %). Hsp90 is induced when a cell undergoes various types of environmental stresses such as heat, cold, or oxygen deprivation. It is involved in the turnover, trafficking, and activity of client proteins, including apoptotic factors, protein kinases, transcription factors, signaling proteins, and a number of oncoproteins. Most of the Hsp90 client proteins are involved in cell growth, differentiation, and survival, and include kinases, nuclear hormone receptors, transcription factors, and other proteins associated with almost all the hallmarks of cancer. Consistent with these diverse activities, genetic and biochemical studies have demonstrated the implication of Hsp90 in a range of diseases, including cancer, making this chaperone an interesting target for drug research.During the last few decades, plant secondary metabolites have been studied as a major source for lead compounds in drug discovery. Recently, several plant-derived small molecules have been discovered exhibiting inhibitory activity towards Hsp90, such as epigallocatechin gallate, gedunin, lentiginosine, celastrol, and deguelin. In this work, an overview of plant secondary metabolites interfering with Hsp90 activities is provided. PMID:26227505

  1. Antioxidant activity of nimesulide and its main metabolites.

    PubMed

    Facino, R M; Carini, M; Aldini, G

    1993-01-01

    The antioxidant activity of nimesulide and its main metabolites, 4'-hydroxynimesulide (M1) and 2-(4'-hydroxyphenoxy)-4-N-acetylamino-methansulfonanilide (M2), was investigated using 2 in vitro models: NADPH-supported lipid peroxidation in rat liver microsomes (marker MDA formation) and xanthine/xanthine oxidase, iron-promoted depolymerisation of hyaluronic acid, determined by gel permeation chromatographic analysis (marker molecular weight distribution). In the lipid peroxidation model, all the compounds inhibited MDA formation in a concentration-dependent manner, although with different potencies; the maximum scavenging effect was observed for M1 [50% inhibitory concentration (IC50) = 30 mumol/L; M2 IC50 = 0.5 mmol/L; nimesulide = 0.8 mmol/L]. Nimesulide was more active than its metabolites in preventing OH-induced depolymerisation of hyaluronic acid, with a 50% effective concentration of approximately 230 mumol/L, which was fairly comparable to that of tenoxicam. This protective effect was due to the OH.-entrapping capacity of the drug, which, in the Fenton-driven model, is easily converted, via OH. attack, to M1 and putatively to 2-hydroxy-4-nitro-methansulfonanilide. PMID:7506157

  2. Selenium metabolite levels in human urine after dosing selenium in different chemical forms

    SciTech Connect

    Hasunuma, Ryoichi; Tsuda, Morizo; Ogawa, Tadao; Kawanishi, Yasuhiro

    1993-11-01

    It has been well known that selenium in marine fish such as tuna and swordfish protects the toxicity of methylmercury in vivo. The protective potency might depend on the chemical forms of selenium in the meat of marine fish sebastes and sperm whale. Little has been revealed, however, on the chemical forms of selenium in the meat of these animals or the selenium metabolites in urine, because the amount of the element is very scarce. Urine is the major excretory route for selenium. The chemical forms of urinary selenium may reflect the metabolism of the element. We have developed methodology for analysis of selenium-containing components in human urine. Using this method, we have observed the time courses of excretory levels of urinary selenium components after a single dose of selenium as selenious acid, selenomethionine, trimethylselenonium ion or tuna meat. 14 refs., 6 figs., 1 tab.

  3. Mutagenic activity of austocystins - secondary metabolites of Aspergillus ustus

    SciTech Connect

    Kfir, R.; Johannsen, E.; Vleggaar, R.

    1986-11-01

    Mycotoxins constitute a group of toxic secondary fungal metabolites. Fungi that produce these toxins frequently contaminate food and feed, creating a potential threat to human and animal health. Biological activities of mycotoxins include, amongst others: toxicity, mutagenicity and carcinogenicity, which can be expressed with or without metabolic activation. Austocystins are similar in structure to aflatoxin B/sup 1/ and are probably synthesized in a similar manner. The Ames Salmonella test, a widely accepted method employed for the detection of mutagenic activity of various chemical compounds was used for testing the mutagenic activity of different mycotoxins. As aflatoxin B/sup 1/ was found by the Ames test to be highly mutagenic, the same test was applied for the study of possible mutagenicity of the austocystins. The mutagenic activity of these compounds was studied with and without metabolic activation using two tester strains of S. typhimurium, one capable of detecting frame shift mutation (strain TA98) and the other capable of detecting base pair substitution (strain TA100).

  4. Depsides: Lichen Metabolites Active against Hepatitis C Virus

    PubMed Central

    Vu, Thi Huyen; Le Lamer, Anne-Cécile; Lalli, Claudia; Boustie, Joël; Samson, Michel

    2015-01-01

    A thorough phytochemical study of Stereocaulon evolutum was conducted, for the isolation of structurally related atranorin derivatives. Indeed, pilot experiments suggested that atranorin (1), the main metabolite of this lichen, would interfere with the lifecycle of hepatitis C virus (HCV). Eight compounds, including one reported for the first time (2), were isolated and characterized. Two analogs (5, 6) were also synthesized, to enlarge the panel of atranorin-related structures. Most of these compounds were active against HCV, with a half-maximal inhibitory concentration of about 10 to 70 µM, with depsides more potent than monoaromatic phenols. The most effective inhibitors (1, 5 and 6) were then added at different steps of the HCV lifecycle. Interestingly, atranorin (1), bearing an aldehyde function at C-3, inhibited only viral entry, whereas the synthetic compounds 5 and 6, bearing a hydroxymethyl and a methyl function, respectively, at C-3 interfered with viral replication. PMID:25793970

  5. Biologically Active Metabolites Produced by the Basidiomycete Quambalaria cyanescens

    PubMed Central

    Stodůlková, Eva; Císařová, Ivana; Kolařík, Miroslav; Chudíčková, Milada; Novák, Petr; Man, Petr; Kuzma, Marek; Pavlů, Barbora; Černý, Jan; Flieger, Miroslav

    2015-01-01

    Four strains of the fungus Quambalaria cyanescens (Basidiomycota: Microstromatales), were used for the determination of secondary metabolites production and their antimicrobial and biological activities. A new naphthoquinone named quambalarine A, (S)-(+)-3-(5-ethyl-tetrahydrofuran-2-yliden)-5,7,8-trihydroxy-2-oxo-1,4-naphthoquinone (1), together with two known naphthoquinones, 3-hexanoyl-2,5,7,8-tetrahydroxy-1,4-naphthoquinone (named here as quambalarine B, 2) and mompain, 2,5,7,8-tetrahydroxy-1,4-naphthoquinone (3) were isolated. Their structures were determined by single-crystal X-ray diffraction crystallography, NMR and MS spectrometry. Quambalarine A (1) had a broad antifungal and antibacterial activity and is able inhibit growth of human pathogenic fungus Aspergillus fumigatus and fungi co-occurring with Q. cyanescens in bark beetle galleries including insect pathogenic species Beauveria bassiana. Quambalarine B (2) was active against several fungi and mompain mainly against bacteria. The biological activity against human-derived cell lines was selective towards mitochondria (2 and 3); after long-term incubation with 2, mitochondria were undetectable using a mitochondrial probe. A similar effect on mitochondria was observed also for environmental competitors of Q. cyanescens from the genus Geosmithia. PMID:25723150

  6. EFFECTS OF METHOPRENE, ITS METABOLITES, AND BREAKDOWN PRODUCTS ON RETINOID-ACTIVATED PATHWAYS IN TRANSFECTED CELL LINES

    EPA Science Inventory

    Methoprene is a terpene-based insecticide designed to act as an agonist of insect juvenile hormone, which is essential for the transition from larval to adult forms in some metamorphic insects. Recent evidence suggests that a methoprene metabolite, methoprene acid, activates a ve...

  7. Phenotypic and metabolic investigation of a CSF-1R kinase receptor inhibitor (BLZ945) and its pharmacologically active metabolite.

    PubMed

    Krauser, Joel A; Jin, Yi; Walles, Markus; Pfaar, Ulrike; Sutton, James; Wiesmann, Marion; Graf, Daniel; Pflimlin-Fritschy, Veronique; Wolf, Thierry; Camenisch, Gian; Swart, Piet

    2015-02-01

    1. 4-[2((1R,2R)-2-Hydroxycyclohexylamino)-benzothiazol-6-yloxyl]-pyridine-2-carboxylic acid methylamide (BLZ945) is a small molecule inhibitor of CSF-1R kinase activity within osteoclasts designed to prevent skeletal related events in metastatic disease. Key metabolites were enzymatically and structurally characterized to understand the metabolic fate of BLZ945 and pharmacological implications. The relative intrinsic clearances for metabolites were derived from in vitro studies using human hepatocytes, microsomes and phenotyped with recombinant P450 enzymes. 2. Formation of a pharmacologically active metabolite (M9) was observed in human hepatocytes. The M9 metabolite is a structural isomer (diastereomer) of BLZ945 and is about 4-fold less potent. This isomer was enzymatically formed via P450 oxidation of the BLZ945 hydroxyl group, followed by aldo-keto reduction to the alcohol (M9). 3. Two reaction phenotyping approaches based on fractional clearances were applied to BLZ945 using hepatocytes and liver microsomes. The fraction metabolized (fm) or contribution ratio was determined for each metabolic reaction type (oxidation, glucuronidation or isomerization) as well as for each metabolite. The results quantitatively illustrate contribution ratios of the involved enzymes and pathways, e.g. the isomerization to metabolite M9 accounted for 24% intrinsic clearance in human hepatocytes. In summary, contribution ratios for the Phase I and Phase II pathways can be determined in hepatocytes. PMID:25180976

  8. Pharmacologically active drug metabolites: therapeutic and toxic activities, plasma and urine data in man, accumulation in renal failure.

    PubMed

    Drayer, D E

    1976-01-01

    Drugs that are administered to man may be biotransformed to yield metabolites that are pharmacologically active. The therapeutic and toxic activities of drug metabolites and the species in which this activity was demonstrated are compiled for the metabolites of 58 drugs. The metabolite to parent drug ratio in the plasma of non-uraemic man and the percentage urinary excretion of the metabolite in non-uraemic man are also tabulated. Those active metabolites with significant pharmacological activity and high plasma levels, both relative to that of the parent drug, will probably contribute substantially to the pharmacological effect ascribed to the parent drug. Active metabolites may accumulate in patients with end stage renal disease if renal excretion is a major elimination pathway for the metabolite. This is true even if the active metabolite is a minor metabolite of the parent drug, as long as the minor metabolite is not further biotransformed and is mainly excreted in the urine. Minor metabolite accumulation may also occur if it is further biotransformed by a pathway inhibited in uraemia. Some clinical examples of the accumulation of active drug metabolites in patients with renal failure are: (a) The abolition of premature ventricular contractions and prevention of paroxysmal atrial tachycardia in some cardiac patients with poor renal function treated with procainamide are associated with high levels of N-acetylprocainamide. (b) The severe irritability and twitching seen in a uraemic patient treated with pethidine (meperidine) are associated with high levels of norpethidine. (c) The severe muscle weakness and tenderness seen in patients with renal failure receiving clofibrate are associated with excessive accumulation of the free acid metabolite of clofibrate. (d) Patients with severe renal insufficiency taking allopurinol appear to experience a higher incidence of side reactions, possibly due to the accumulation of oxipurinol. (e) Accumulation of free and

  9. Toxic Dopamine Metabolite DOPAL Forms an Unexpected Dicatechol Pyrrole Adduct with Lysines of α-Synuclein.

    PubMed

    Werner-Allen, Jon W; DuMond, Jenna F; Levine, Rodney L; Bax, Ad

    2016-06-20

    Parkinson's disease has long been known to involve the loss of dopaminergic neurons in the substantia nigra and the coincidental appearance of Lewy bodies containing oligomerized forms of α-synuclein. The "catecholaldehyde hypothesis" posits a causal link between these two central pathologies mediated by 3,4-dihydroxyphenylacetaldehyde (DOPAL), the most toxic dopamine metabolite. Here we determine the structure of the dominant product in reactions between DOPAL and α-synuclein, a dicatechol pyrrole lysine adduct. This novel modification results from the addition of two DOPAL molecules to the Lys sidechain amine through their aldehyde moieties and the formation of a new carbon-carbon bond between their alkyl chains to generate a pyrrole ring. The product is detectable at low concentrations of DOPAL and its discovery should provide a valuable chemical basis for future studies of DOPAL-induced crosslinking of α-synuclein. PMID:27158766

  10. Integrating phylogeny, geographic niche partitioning and secondary metabolite synthesis in bloom-forming Planktothrix.

    PubMed

    Kurmayer, Rainer; Blom, Judith F; Deng, Li; Pernthaler, Jakob

    2015-04-01

    Toxic freshwater cyanobacteria form harmful algal blooms that can cause acute toxicity to humans and livestock. Globally distributed, bloom-forming cyanobacteria Planktothrix either retain or lose the mcy gene cluster (encoding the synthesis of the secondary metabolite hepatotoxin microcystin or MC), resulting in a variable spatial/temporal distribution of (non)toxic genotypes. Despite their importance to human well-being, such genotype diversity is not being mapped at scales relevant to nature. We aimed to reveal the factors influencing the dispersal of those genotypes by analyzing 138 strains (from Europe, Russia, North America and East Africa) for their (i) mcy gene cluster composition, (ii) phylogeny and adaptation to their habitat and (iii) ribosomally and nonribosomally synthesized oligopeptide products. Although all the strains from different species contained at least remnants of the mcy gene cluster, various phylogenetic lineages evolved and adapted to rather specific ecological niches (for example, through pigmentation and gas vesicle protein size). No evidence for an increased abundance of specific peptides in the absence of MC was found. MC and peptide distribution rather depended on phylogeny, ecophysiological adaptation and geographic distance. Together, these findings provide evidence that MC and peptide production are primarily related to speciation processes, while within a phylogenetic lineage the probability that strains differ in peptide composition increases with geographic distance. PMID:25325384

  11. Flavonoid metabolite 3-(3-hydroxyphenyl)propionic acid formed by human microflora decreases arterial blood pressure in rats.

    PubMed

    Najmanová, Iveta; Pourová, Jana; Vopršalová, Marie; Pilařová, Veronika; Semecký, Vladimír; Nováková, Lucie; Mladěnka, Přemysl

    2016-05-01

    There are reports of positive effects of quercetin on cardiovascular pathologies, however, mainly due to its low biovailability, the mechanism remains elusive. Here, we report that one metabolite formed by human microflora (3-(3-hydroxyphenyl)propionic acid)relaxed isolated rat aorta and decreased arterial blood pressure in rats. PMID:26790841

  12. COMPARISON OF CHOLINESTERASE ACTIVITY, RESIDUE LEVELS, AND URINARY METABOLITE EXCRETION OF RATS EXPOSED TO ORGANOPHOSPHORUS PESTICIDES

    EPA Science Inventory

    Blood cholinesterase activity, urinary levels of phenolic and organophosphorus metabolites, and residues of intact compounds in blood and fat were determined following exposure of rats to organophosphorus pesticides. The eight pesticides studied included representative halogenate...

  13. Widespread occurrence of neuro-active pharmaceuticals and metabolites in 24 Minnesota rivers and wastewaters.

    PubMed

    Writer, Jeffrey H; Ferrer, Imma; Barber, Larry B; Thurman, E Michael

    2013-09-01

    Concentrations of 17 neuro-active pharmaceuticals and their major metabolites (bupropion, hydroxy-bupropion, erythro-hydrobupropion, threo-hydrobupropion, carbamazepine, 10,11,-dihydro-10,11,-dihydroxycarbamazepine, 10-hydroxy-carbamazepine, citalopram, N-desmethyl-citalopram, fluoxetine, norfluoxetine, gabapentin, lamotrigine, 2-N-glucuronide-lamotrigine, oxcarbazepine, venlafaxine and O-desmethyl-venlafaxine), were measured in treated wastewater and receiving surface waters from 24 locations across Minnesota, USA. The analysis of upstream and downstream sampling sites indicated that the wastewater treatment plants were the major source of the neuro-active pharmaceuticals and associated metabolites in surface waters of Minnesota. Concentrations of parent compound and the associated metabolite varied substantially between treatment plants (concentrations±standard deviation of the parent compound relative to its major metabolite) as illustrated by the following examples; bupropion and hydrobupropion 700±1000 ng L(-1), 2100±1700 ng L(-1), carbamazepine and 10-hydroxy-carbamazepine 480±380 ng L(-1), 360±400 ng L(-1), venlafaxine and O-desmethyl-venlafaxine 1400±1300 ng L(-1), 1800±2300 ng L(-1). Metabolites of the neuro-active compounds were commonly found at higher or comparable concentrations to the parent compounds in wastewater effluent and the receiving surface water. Neuro-active pharmaceuticals and associated metabolites were detected only sporadically in samples upstream from the effluent outfall. Metabolite to parent ratios were used to evaluate transformation, and we determined that ratios in wastewater were much lower than those reported in urine, indicating that the metabolites are relatively more labile than the parent compounds in the treatment plants and in receiving waters. The widespread occurrence of neuro-active pharmaceuticals and metabolites in Minnesota effluents and surface waters indicate that this is likely a global environmental issue

  14. Analysis of benzo[a]pyrene metabolites formed by rat hepatic microsomes using high pressure liquid chromatography: optimization of the method

    PubMed Central

    Moserová, Michaela; Kotrbová, Věra; Aimová, Dagmar; Šulc, Miroslav; Frei, Eva; Stiborová, Marie

    2009-01-01

    A simple and sensitive method was developed to separate the carcinogenic polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (BaP), and six of its oxidation metabolites generated by rat hepatic microsomes enriched with cytochrome P450 (CYP) 1A1, by high pressure liquid chromatography (HPLC). The HPLC method, using an acetonitrile/water gradient as mobile phase and UV detection, provided appropriate separation and detection of both mono- and di-hydroxylated metabolites of BaP as well as BaP diones formed by rat hepatic microsomes and the parental BaP. In this enzymatic system, 3-hydroxy BaP, 9-hydroxy BaP, BaP-4,5-dihydrodiol, BaP-7,8-dihydrodiol, BaP-9,10-dihydrodiol and BaP-dione were generated. Among them the mono-hydroxylated BaP metabolite, 3-hydroxy BaP followed by di-hydroxylated BaP products, BaP-7,8-dihydrodiol and BaP-9,10-dihydrodiol, predominated, while BaP-dione was a minor metabolite. This HPLC method will be useful for further defining the roles of the CYP1A1 enzyme with both in vitro and in vivo models in understanding its real role in activation and detoxification of BaP. PMID:21217860

  15. Structural Characterization of a Therapeutic Anti-Methamphetamine Antibody Fragment: Oligomerization and Binding of Active Metabolites

    PubMed Central

    Gokulan, Kuppan; Varughese, Kottayil I.

    2013-01-01

    Vaccines and monoclonal antibodies (mAb) for treatment of (+)-methamphetamine (METH) abuse are in late stage preclinical and early clinical trial phases, respectively. These immunotherapies work as pharmacokinetic antagonists, sequestering METH and its metabolites away from sites of action in the brain and reduce the rewarding and toxic effects of the drug. A key aspect of these immunotherapy strategies is the understanding of the subtle molecular interactions important for generating antibodies with high affinity and specificity for METH. We previously determined crystal structures of a high affinity anti-METH therapeutic single chain antibody fragment (scFv6H4, KD = 10 nM) in complex with METH and the (+) stereoisomer of 3,4-methylenedioxymethamphetamine (MDMA, or “ecstasy”). Here we report the crystal structure of scFv6H4 in homo-trimeric unbound (apo) form (2.60Å), as well as monomeric forms in complex with two active metabolites; (+)-amphetamine (AMP, 2.38Å) and (+)-4-hydroxy methamphetamine (p-OH-METH, 2.33Å). The apo structure forms a trimer in the crystal lattice and it results in the formation of an intermolecular composite beta-sheet with a three-fold symmetry. We were also able to structurally characterize the coordination of the His-tags with Ni2+. Two of the histidine residues of each C-terminal His-tag interact with Ni2+ in an octahedral geometry. In the apo state the CDR loops of scFv6H4 form an open conformation of the binding pocket. Upon ligand binding, the CDR loops adopt a closed formation, encasing the drug almost completely. The structural information reported here elucidates key molecular interactions important in anti-methamphetamine abuse immunotherapy. PMID:24349338

  16. Ardipusilloside-I Metabolites from Human Intestinal Bacteria and Their Antitumor Activity.

    PubMed

    Cao, Wei-Yu; Wang, Ya-Nan; Wang, Peng-Yuan; Lei, Wan; Feng, Bin; Wang, Xiao-Juan

    2015-01-01

    Ardipusilloside-I (ADS-I) is a triterpenoid saponin extracted from Ardisia pusilla DC, and has been demonstrated to have potent antitumor activity. However, ADS-I metabolism in humans has not been investigated. In this study, we studied the biotransformation of ADS-I in human intestinal bacteria, and examined the in vitro antitumor activity of the major metabolites. Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to detect ADS-I biotransformation products, and their chemical structures were identified by high performance liquid chromatography-nuclear magnetic resonance (HPLC-NMR). The antitumor activity of the major metabolites was determined by the MTT assay. Here, we show that main reaction seen in the metabolism of ADS-I in human intestinal bacteria was deglycosylation, which produced a total of four metabolites. The structures of the two major metabolites M1 and M2 were confirmed by using NMR. MTT assay showed that ADS-I metabolites M1 and M2 have the same levels of inhibitory activities as ADS-I in cultured SMMC-7721 cells and MCF-7 cells. In conclusion, this study demonstrates deglycosylation as a primary pathway of ADS-I metabolism in human intestinal bacteria, and suggests that the pharmacological activity of ADS-I may be mediated, at least in part, by its metabolites. PMID:26610438

  17. Antiproliferative and hepatoprotective activity of metabolites from Corynebacterium xerosis against Ehrlich Ascites Carcinoma cells

    PubMed Central

    Islam, Farhadul; Ghosh, Soby; Khanam, Jahan Ara

    2014-01-01

    Objective To find out the effective anticancer drugs from bacterial products, petroleum ether extract of Corynebacterium xerosis. Methods Antiproliferative activity of the metabolite has been measured by monitoring the parameters like tumor weight measurement, tumor cell growth inhibition in mice and survival time of tumor bearing mice, etc. Hepatoprotective effect of the metabolites was determined by observing biochemical, hematological parameters. Results It has been found that the petroleum ether extract bacterial metabolite significantly decrease cell growth (78.58%; P<0.01), tumor weight (36.04 %; P<0.01) and increase the life span of tumor bearing mice (69.23%; P<0.01) at dose 100 mg/kg (i.p.) in comparison to those of untreated Ehrlich ascites carcinoma (EAC) bearing mice. The metabolite also alters the depleted hematological parameters like red blood cell, white blood cell, hemoglobin (Hb%), etc. towards normal in tumor bearing mice. Metabolite show no adverse effect on liver functions regarding blood glucose, serum alkaline phosphatases, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase activity and serum billirubin, etc. in normal mice. Histopathological observation of these mice organ does not show any toxic effect on cellular structure. But in the case of EAC bearing untreated mice these hematological and biochemical parameters deteriorate extremely with time whereas petroleum ether extract bacterial metabolite receiving EAC bearing mice nullified the toxicity induced by EAC cells. Conclusion Study results reveal that metabolite possesses significant antiproliferative and hepatoprotective effect against EAC cells. PMID:25183099

  18. Benzene's metabolites alter c-MYB activity via reactive oxygen species in HD3 cells

    SciTech Connect

    Wan, Joanne; Winn, Louise M. . E-mail: winnl@queensu.ca

    2007-07-15

    Benzene is a known leukemogen that is metabolized to form reactive intermediates and reactive oxygen species (ROS). The c-Myb oncoprotein is a transcription factor that has a critical role in hematopoiesis. c-Myb transcript and protein have been overexpressed in a number of leukemias and cancers. Given c-Myb's role in hematopoiesis and leukemias, it is hypothesized that benzene interferes with the c-Myb signaling pathway and that this involves ROS. To investigate our hypothesis, we evaluated whether benzene, 1,4-benzoquinone, hydroquinone, phenol, and catechol generated ROS in chicken erythroblast HD3 cells, as measured by 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (DCFDA) and dihydrorhodamine-123 (DHR-123), and whether the addition of 100 U/ml of the antioxidating enzyme superoxide dismutase (SOD) could prevent ROS generation. Reduced to oxidized glutathione ratios (GSH:GSSG) were also assessed as well as hydroquinone and benzoquinone's effects on c-Myb protein levels and activation of a transiently transfected reporter construct. Finally we attempted to abrogate benzene metabolite mediated increases in c-Myb activity with the use of SOD. We found that benzoquinone, hydroquinone, and catechol increased DCFDA fluorescence, increased DHR-123 fluorescence, decreased GSH:GSSG ratios, and increased reporter construct expression after 24 h of exposure. SOD was able to prevent DCFDA fluorescence and c-Myb activity caused by benzoquinone and hydroquinone only. These results are consistent with other studies, which suggest metabolite differences in benzene-mediated toxicity. More importantly, this study supports the hypothesis that benzene may mediate its toxicity through ROS-mediated alterations in the c-Myb signaling pathway.

  19. Reactive metabolites and agranulocytosis.

    PubMed

    Uetrecht, J P

    1996-01-01

    Central to most hypotheses of the mechanism of idiosyncratic drug-induced blood dyscrasias is the involvement of reactive metabolites. In view of the reactive nature of the majority of such metabolites, it is likely that they are formed by, or in close proximity to the blood cells affected. The major oxidative system of neutrophils generates hypochlorous acid. We have demonstrated that the drugs associated with the highest incidence of agranulocytosis are oxidized to reactive metabolites by hypochlorous acid and/or activated neutrophils. There are many mechanisms by which such reactive metabolites could induce agranulocytosis. In the case of aminopyrine-induced agranulocytosis, most cases appear to involve drug-dependent anti-neutrophil antibodies, and these are likely to be induced by cell membrane antigens modified by the reactive metabolite of aminopyrine. The target of agranulocytosis associated with many other drugs is usually neutrophil precursors and may involve cytotoxicity or a cell-mediated immune reaction induced by a reactive metabolite. In the case of aplastic anaemia, there is evidence in some cases for involvement of cytotoxic T cells, which could either be induced by metabolites generated by neutrophils, or more likely, by reactive metabolites generated by stem cells. PMID:8987247

  20. Effects of 3-O-methyldopa, L-3,4-dihydroxyphenylalanine metabolite, on locomotor activity and dopamine turnover in rats.

    PubMed

    Onzawa, Yoritaka; Kimura, Yasuhiro; Uzuhashi, Kengo; Shirasuna, Megumi; Hirosawa, Tasuku; Taogoshi, Takanori; Kihira, Kenji

    2012-01-01

    It has been well known that 3-O-methyldopa (3-OMD) is a metabolite of L-3,4-dihydroxyphenylalanine (L-DOPA) formed by catechol O-methyltransferase (COMT), and 3-OMD blood level often reaches higher than physiological level in Parkinson's disease (PD) patients receiving long term L-DOPA therapy. However, the physiological role of 3-OMD has not been well understood. Therefore, in order to clarify the effects of 3-OMD on physiological function, we examined the behavioral alteration in rats based on locomotor activity, and measured dopamine (DA) and its metabolites levels in rats at the same time after 3-OMD subchronic administration. The study results showed that repeated administrations of 3-OMD increased its blood and the striatum tissue levels in those rats, and decreased locomotor activity in a dose dependent manner. Although 3-OMD subchronic administration showed no significant change in DA level in the striatum, DA metabolite levels, such as 3,4-dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT), and homovanillic acid (HVA) were significantly decreased. After 3-OMD washout period (7 d), locomotor activity and DA turnover in those rats returned to normal levels. Furthermore, locomotor activity and DA turnover decreased by 3-OMD administration were recovered to normal level by acute L-DOPA administration. These results suggested that 3-OMD affect to locomotor activity via DA neuron system. In conclusion, 3-OMD itself may have a disadvantage in PD patients receiving L-DOPA therapy. PMID:22863920

  1. Not flavone-8-acetic acid (FAA) but its murine metabolite 6-OH-FAA exhibits remarkable antivascular activities in vitro.

    PubMed

    Pham, Minh Hien; Dauzonne, Daniel; Chabot, Guy G

    2016-06-01

    Flavone-8-acetic acid (FAA) has been proved to be a potent vascular-disrupting agent in mice. Unfortunately, FAA did not produce any anticancer activity in clinical trials. Previously, we had reported that FAA is metabolized by mouse microsomes into six metabolites, whereas it was poorly metabolized by human microsomes, with fewer metabolites formed in lesser amounts. Especially, 6-OH-FAA was not formed by human microsomes. In this work, two major available metabolites, 4'-OH-FAA and 6-OH-FAA, were tested and compared with the parent compound FAA for their potential antivascular activities in vitro. The ability of the products to induce morphological changes, disrupt preformed capillaries of EA.hy926 endothelial cells and inhibit tubulin polymerization in vitro was assessed. The action mechanism was determined using the RhoA and Rac1 inhibitors. At 25 µg/ml, 6-OH-FAA induced morphological changes and membrane blebbing, whereas 300 µg/ml of FAA and 4'-OH-FAA slightly changed the morphology without inducing membrane blebbing. At 300 µg/ml, 6-OH-FAA produced morphological changes that were 2.1-6.9-fold greater than that produced by FAA and 4'-OH-FAA, an effect that was consistent with its much greater inhibitory effect on tubulin polymerization compared with FAA and 4'-OH-FAA. 6-OH-FAA significantly disrupted the EA.hy926 cell capillaries. 6-OH-FAA activities were prevented in EA.hy926 cells pretreated with RhoA, but not Rac1, inhibitor. In this short communication we report for the first time that, in vitro, 6-OH-FAA, a mouse-specific FAA metabolite, exhibits significantly stronger antivascular activities compared with FAA and 4'-OH-FAA, which are mediated through the RhoA kinase pathway. PMID:26901071

  2. Diversity of Secondary Metabolites from Marine Bacillus Species: Chemistry and Biological Activity

    PubMed Central

    Mondol, Muhammad Abdul Mojid; Shin, Hee Jae; Islam, Mohammad Tofazzal

    2013-01-01

    Marine Bacillus species produce versatile secondary metabolites including lipopeptides, polypeptides, macrolactones, fatty acids, polyketides, and isocoumarins. These structurally diverse compounds exhibit a wide range of biological activities, such as antimicrobial, anticancer, and antialgal activities. Some marine Bacillus strains can detoxify heavy metals through reduction processes and have the ability to produce carotenoids. The present article reviews the chemistry and biological activities of secondary metabolites from marine isolates. Side by side, the potential for application of these novel natural products from marine Bacillus strains as drugs, pesticides, carotenoids, and tools for the bioremediation of heavy metal toxicity are also discussed. PMID:23941823

  3. Diversity of secondary metabolites from marine Bacillus species: chemistry and biological activity.

    PubMed

    Mondol, Muhammad Abdul Mojid; Shin, Hee Jae; Islam, Mohammad Tofazzal

    2013-08-01

    Marine Bacillus species produce versatile secondary metabolites including lipopeptides, polypeptides, macrolactones, fatty acids, polyketides, and isocoumarins. These structurally diverse compounds exhibit a wide range of biological activities, such as antimicrobial, anticancer, and antialgal activities. Some marine Bacillus strains can detoxify heavy metals through reduction processes and have the ability to produce carotenoids. The present article reviews the chemistry and biological activities of secondary metabolites from marine isolates. Side by side, the potential for application of these novel natural products from marine Bacillus strains as drugs, pesticides, carotenoids, and tools for the bioremediation of heavy metal toxicity are also discussed. PMID:23941823

  4. Evaluation of Bacillus cereus and Bacillus pumilus metabolites for anthelmintic activity

    PubMed Central

    Kumar, M. L. Vijaya; Thippeswamy, B.; Kuppust, I. L.; Naveenkumar, K. J.; Shivakumar, C. K.

    2015-01-01

    Objective: To assess the anthelmintic acivity of Bacillus cereus and Bacillus pumilus metabolites. Materials and Methods: The successive solvent extractions with petroleum ether, ethyl acetate and methanol. The solvent extracts were tested for anthelmintic activity against Pheretima posthuma at 20 mg/ml concentration. The time of paralysis and time of death of the worms was determined for all the extracts. Albendazole was taken as a standard reference and sterile water as a control. Results: All the sample extracts showed significant anthelmintic activity in paralyzing the worms comparable with that of the standard drug. The time of death exhibited by BP metabolites was close to the time exhibited by standard. Conclusion: The study indicates both bacteria Bacillus cereus and Bacillus pumilus have anthelmintic activity indicating potential metabolites in them. PMID:25598639

  5. Curcumin Pharmacokinetic and Pharmacodynamic Evidences in Streptozotocin-Diabetic Rats Support the Antidiabetic Activity to Be via Metabolite(s)

    PubMed Central

    Gutierres, Vânia Ortega; Campos, Michel Leandro; Arcaro, Carlos Alberto; Assis, Renata Pires; Baldan-Cimatti, Helen Mariana; Peccinini, Rosângela Gonçalves; Paula-Gomes, Silvia; Kettelhut, Isis Carmo; Baviera, Amanda Martins; Brunetti, Iguatemy Lourenço

    2015-01-01

    This study measures the curcumin concentration in rat plasma by liquid chromatography and investigates the changes in the glucose tolerance and insulin sensitivity of streptozotocin-diabetic rats treated with curcumin-enriched yoghurt. The analytical method for curcumin detection was linear from 10 to 500 ng/mL. The Cmax⁡ and the time to reach Cmax⁡ (tmax⁡) of curcumin in plasma were 3.14 ± 0.9 μg/mL and 5 minutes (10 mg/kg, i.v.) and 0.06 ± 0.01 μg/mL and 14 minutes (500 mg/kg, p.o.). The elimination half-time was 8.64 ± 2.31 (i.v.) and 32.70 ± 12.92 (p.o.) minutes. The oral bioavailability was about 0.47%. Changes in the glucose tolerance and insulin sensitivity were investigated in four groups: normal and diabetic rats treated with yoghurt (NYOG and DYOG, resp.) and treated with 90 mg/kg/day curcumin incorporated in yoghurt (NC90 and DC90, resp.). After 15 days of treatment, the glucose tolerance and the insulin sensitivity were significantly improved in DC90 rats in comparison with DYOG, which can be associated with an increase in the AKT phosphorylation levels and GLUT4 translocation in skeletal muscles. These findings can explain, at least in part, the benefits of curcumin-enriched yoghurt to diabetes and substantiate evidences for the curcumin metabolite(s) as being responsible for the antidiabetic activity. PMID:26064170

  6. Widespread occurrence of neuro-active pharmaceuticals and metabolites in 24 Minnesota rivers and wastewaters

    USGS Publications Warehouse

    Writer, Jeffrey; Ferrer, Imma; Barber, Larry B.; Thurman, E. Michael

    2013-01-01

    Concentrations of 17 neuro-active pharmaceuticals and their major metabolites (bupropion, hydroxy-bupropion, erythro-hydrobupropion, threo-hydrobupropion, carbamazepine, 10,11,-dihydro-10,11,-dihydroxycarbamazepine, 10-hydroxy-carbamazepine, citalopram, N-desmethyl-citalopram, fluoxetine, norfluoxetine, gabapentin, lamotrigine, 2-N-glucuronide-lamotrigine, oxcarbazepine, venlafaxine and O-desmethyl-venlafaxine), were measured in treated wastewater and receiving surface waters from 24 locations across Minnesota, USA. The analysis of upstream and downstream sampling sites indicated that the wastewater treatment plants were the major source of the neuro-active pharmaceuticals and associated metabolites in surface waters of Minnesota. Concentrations of parent compound and the associated metabolite varied substantially between treatment plants (concentrations ± standard deviation of the parent compound relative to its major metabolite) as illustrated by the following examples; bupropion and hydrobupropion 700 ± 1000 ng L−1, 2100 ± 1700 ng L−1, carbamazepine and 10-hydroxy-carbamazepine 480 ± 380 ng L−1, 360 ± 400 ng L−1, venlafaxine and O-desmethyl-venlafaxine 1400 ± 1300 ng L−1, 1800 ± 2300 ng L−1. Metabolites of the neuro-active compounds were commonly found at higher or comparable concentrations to the parent compounds in wastewater effluent and the receiving surface water. Neuro-active pharmaceuticals and associated metabolites were detected only sporadically in samples upstream from the effluent outfall. Metabolite to parent ratios were used to evaluate transformation, and we determined that ratios in wastewater were much lower than those reported in urine, indicating that the metabolites are relatively more labile than the parent compounds in the treatment plants and in receiving waters. The widespread occurrence of neuro-active pharmaceuticals and metabolites in Minnesota effluents and surface waters indicate that

  7. Spectrofluorimetric determination of 3-methylflavone-8-carboxylic acid, the main active metabolite of flavoxate hydrochloride in human urine

    NASA Astrophysics Data System (ADS)

    Zaazaa, Hala E.; Mohamed, Afaf O.; Hawwam, Maha A.; Abdelkawy, Mohamed

    2015-01-01

    A simple, sensitive and selective spectrofluorimetric method has been developed for the determination of 3-methylflavone-8-carboxylic acid as the main active metabolite of flavoxate hydrochloride in human urine. The proposed method was based on the measurement of the native fluorescence of the metabolite in methanol at an emission wavelength 390 nm, upon excitation at 338 nm. Moreover, the urinary excretion pattern has been calculated using the proposed method. Taking the advantage that 3-methylflavone-8-carboxylic acid is also the alkaline degradate, the proposed method was applied to in vitro determination of flavoxate hydrochloride in tablets dosage form via the measurement of its corresponding degradate. The method was validated in accordance with the ICH requirements and statistically compared to the official method with no significant difference in performance.

  8. Investigation of fixed wavelength fluorescence results for biliary metabolites of polycyclic aromatic hydrocarbons formed in Atlantic cod (Gadus morhua).

    PubMed

    Pampanin, Daniela M; Kemppainen, Eeva K; Skogland, Karianne; Jørgensen, Kåre B; Sydnes, Magne O

    2016-02-01

    Fixed wavelength fluorescence (FF) and synchronous fluorescence scanning (SFS) of fish bile are commonly used methods to analyze for exposure to polycyclic aromatic hydrocarbons (PAHs) from petrogenic and pyrogenic sources. A range of conjugated oxidation products from petrogenic PAHs are normally accumulated in the bile. Therefore their detection is important. In the present study, phenanthrene and naphthalene metabolites, formed in vivo in Atlantic cod (Gadus morhua), were used to study the response of these compounds in both FF and SFS analyses. The selected synthetic metabolites were (-)-(1R,2R)-1,2-dihydrophenanthrene-1,2-diol and (-)-(1R,2R)-1,2-dihydronaphthalene-1,2-diol. The study findings showed that the recommended excitation and emission wavelengths for FF analysis do not comprise the maximum emission wavelengths for these metabolites, providing an incorrect estimation of the PAH exposure. A method developed in our laboratory for the synthesis of (-)-(1R,2R)-1,2-dihydrophenanthrene-1,2-diol is also described. PMID:26492423

  9. Anti-Oxidative Activity of Mytiloxanthin, a Metabolite of Fucoxanthin in Shellfish and Tunicates

    PubMed Central

    Maoka, Takashi; Nishino, Azusa; Yasui, Hiroyuki; Yamano, Yumiko; Wada, Akimori

    2016-01-01

    Anti-oxidative activities of mytiloxanthin, a metabolite of fucoxanthin in shellfish and tunicates, were investigated. Mytiloxanthin showed almost the same activities for quenching singlet oxygen and the inhibition of lipid peroxidation as those of astaxanthin, which is a well-known singlet oxygen quencher. Furthermore, mytiloxanthin showed excellent scavenging activity for hydroxyl radicals and this activity was markedly higher than that of astaxanthin. PMID:27187417

  10. Anti-Oxidative Activity of Mytiloxanthin, a Metabolite of Fucoxanthin in Shellfish and Tunicates.

    PubMed

    Maoka, Takashi; Nishino, Azusa; Yasui, Hiroyuki; Yamano, Yumiko; Wada, Akimori

    2016-01-01

    Anti-oxidative activities of mytiloxanthin, a metabolite of fucoxanthin in shellfish and tunicates, were investigated. Mytiloxanthin showed almost the same activities for quenching singlet oxygen and the inhibition of lipid peroxidation as those of astaxanthin, which is a well-known singlet oxygen quencher. Furthermore, mytiloxanthin showed excellent scavenging activity for hydroxyl radicals and this activity was markedly higher than that of astaxanthin. PMID:27187417

  11. Antifeedant Activity of Ginkgo biloba Secondary Metabolites against Hyphantria cunea Larvae: Mechanisms and Applications.

    PubMed

    Pan, Long; Ren, Lili; Chen, Fang; Feng, Yuqian; Luo, Youqing

    2016-01-01

    Ginkgo biloba is a typical relic plant that rarely suffers from pest hazards. This study analyzed the pattern of G. biloba pest hazards in Beijing; tested the antifeedant activity of G. biloba extracts, including ginkgo flavonoids, ginkgolide, and bilobalide, against Hyphantria cunea larvae; determined the activities of glutathione transferase (GSTs), acetylcholinesterase (AChE), carboxylesterase (CarE) and mixed-functional oxidase (MFO), in larvae after feeding on these G. biloba secondary metabolites; and screened for effective botanical antifeedants in the field. In this study, no indicators of insect infestation were found for any of the examined leaves of G. biloba; all tested secondary metabolites showed significant antifeedant activity and affected the activity of the four larval detoxifying enzymes. Ginkgolide had the highest antifeedant activity and the most significant effect on the detoxifying enzymes (P<0.05). Spraying leaves with G. biloba extracts or ginkgolide both significantly repelled H. cunea larvae in the field (P<0.05), although the former is more economical and practical. This study investigated the antifeedant activity of G. biloba secondary metabolites against H. cunea larvae, and the results provide new insights into the mechanism of G. biloba pest resistance. This study also developed new applications of G. biloba secondary metabolites for effective pest control. PMID:27214257

  12. Antifeedant Activity of Ginkgo biloba Secondary Metabolites against Hyphantria cunea Larvae: Mechanisms and Applications

    PubMed Central

    Ren, Lili; Chen, Fang; Feng, Yuqian

    2016-01-01

    Ginkgo biloba is a typical relic plant that rarely suffers from pest hazards. This study analyzed the pattern of G. biloba pest hazards in Beijing; tested the antifeedant activity of G. biloba extracts, including ginkgo flavonoids, ginkgolide, and bilobalide, against Hyphantria cunea larvae; determined the activities of glutathione transferase (GSTs), acetylcholinesterase (AChE), carboxylesterase (CarE) and mixed-functional oxidase (MFO), in larvae after feeding on these G. biloba secondary metabolites; and screened for effective botanical antifeedants in the field. In this study, no indicators of insect infestation were found for any of the examined leaves of G. biloba; all tested secondary metabolites showed significant antifeedant activity and affected the activity of the four larval detoxifying enzymes. Ginkgolide had the highest antifeedant activity and the most significant effect on the detoxifying enzymes (P<0.05). Spraying leaves with G. biloba extracts or ginkgolide both significantly repelled H. cunea larvae in the field (P<0.05), although the former is more economical and practical. This study investigated the antifeedant activity of G. biloba secondary metabolites against H. cunea larvae, and the results provide new insights into the mechanism of G. biloba pest resistance. This study also developed new applications of G. biloba secondary metabolites for effective pest control. PMID:27214257

  13. Estrogenic activities of diuron metabolites in female Nile tilapia (Oreochromis niloticus).

    PubMed

    Pereira, Thiago Scremin Boscolo; Boscolo, Camila Nomura Pereira; Felício, Andreia Arantes; Batlouni, Sergio Ricardo; Schlenk, Daniel; de Almeida, Eduardo Alves

    2016-03-01

    Some endocrine disrupting chemicals (EDCs) can alter the estrogenic activities of the organism by directly interacting with estrogen receptors (ER) or indirectly through the hypothalamus-pituitary-gonadal axis. Recent studies in male Nile tilapia (Oreochromis niloticus) indicated that diuron may have anti-androgenic activity augmented by biotransformation. In this study, the effects of diuron and three of its metabolites were evaluated in female tilapia. Sexually mature female fish were exposed for 25 days to diuron, as well as to its metabolites 3,4-dichloroaniline (DCA), 3,4-dichlorophenylurea (DCPU) and 3,4-dichlorophenyl-N-methylurea (DCPMU), at concentrations of 100 ng/L. Diuron metabolites caused increases in E2 plasma levels, gonadosomatic indices and in the percentage of final vitellogenic oocytes. Moreover, diuron and its metabolites caused a decrease in germinative cells. Significant differences in plasma concentrations of the estrogen precursor and gonadal regulator17α-hydroxyprogesterone (17α-OHP) were not observed. These results show that diuron metabolites had estrogenic effects potentially mediated through enhanced estradiol biosynthesis and accelerated the ovarian development of O. niloticus females. PMID:26741556

  14. Phytol metabolites are circulating dietary factors that activate the nuclear receptor RXR.

    PubMed Central

    Kitareewan, S; Burka, L T; Tomer, K B; Parker, C E; Deterding, L J; Stevens, R D; Forman, B M; Mais, D E; Heyman, R A; McMorris, T; Weinberger, C

    1996-01-01

    RXR is a nuclear receptor that plays a central role in cell signaling by pairing with a host of other receptors. Previously, 9-cis-retinoic acid (9cRA) was defined as a potent RXR activator. Here we describe a unique RXR effector identified from organic extracts of bovine serum by following RXR-dependent transcriptional activity. Structural analyses of material in active fractions pointed to the saturated diterpenoid phytanic acid, which induced RXR-dependent transcription at concentrations between 4 and 64 microM. Although 200 times more potent than phytanic acid, 9cRA was undetectable in equivalent amounts of extract and cannot be present at a concentration that could account for the activity. Phytanic acid, another phytol metabolite, was synthesized and stimulated RXR with a potency and efficacy similar to phytanic acid. These metabolites specifically displaced [3H]-9cRA from RXR with Ki values of 4 microM, indicating that their transcriptional effects are mediated by direct receptor interactions. Phytol metabolites are compelling candidates for physiological effectors, because their RXR binding affinities and activation potencies match their micromolar circulating concentrations. Given their exclusive dietary origin, these chlorophyll metabolites may represent essential nutrients that coordinate cellular metabolism through RXR-dependent signaling pathways. PMID:8856661

  15. Microbial communication leading to the activation of silent fungal secondary metabolite gene clusters

    PubMed Central

    Netzker, Tina; Fischer, Juliane; Weber, Jakob; Mattern, Derek J.; König, Claudia C.; Valiante, Vito; Schroeckh, Volker; Brakhage, Axel A.

    2015-01-01

    Microorganisms form diverse multispecies communities in various ecosystems. The high abundance of fungal and bacterial species in these consortia results in specific communication between the microorganisms. A key role in this communication is played by secondary metabolites (SMs), which are also called natural products. Recently, it was shown that interspecies “talk” between microorganisms represents a physiological trigger to activate silent gene clusters leading to the formation of novel SMs by the involved species. This review focuses on mixed microbial cultivation, mainly between bacteria and fungi, with a special emphasis on the induced formation of fungal SMs in co-cultures. In addition, the role of chromatin remodeling in the induction is examined, and methodical perspectives for the analysis of natural products are presented. As an example for an intermicrobial interaction elucidated at the molecular level, we discuss the specific interaction between the filamentous fungi Aspergillus nidulans and Aspergillus fumigatus with the soil bacterium Streptomyces rapamycinicus, which provides an excellent model system to enlighten molecular concepts behind regulatory mechanisms and will pave the way to a novel avenue of drug discovery through targeted activation of silent SM gene clusters through co-cultivations of microorganisms. PMID:25941517

  16. Rapidly Probing Antibacterial Activity of Graphene Oxide by Mass Spectrometry-based Metabolite Fingerprinting

    PubMed Central

    Zhang, Ning; Hou, Jian; Chen, Suming; Xiong, Caiqiao; Liu, Huihui; Jin, Yulong; Wang, Jianing; He, Qing; Zhao, Rui; Nie, Zongxiu

    2016-01-01

    Application of nanomaterials as anti-bacteria agents has aroused great attention. To investigate the antibacterial activity and antibacterial mechanism of nanomaterials from a molecular perspective is important for efficient developing of nanomaterial antibiotics. In the current work, a new mass spectrometry-based method was established to investigate the bacterial cytotoxicity of graphene oxide (GO) by the metabolite fingerprinting of microbes. The mass spectra of extracted metabolites from two strains DH5α and ATCC25922 were obtained before and after the incubation with nanomaterials respectively. Then principal component analysis (PCA) of these spectra was performed to reveal the relationship between the metabolism disorder of microbes and bactericidal activity of GO. A parameter “D” obtained from PCA scores was proposed that is capable to quantitatively evaluate the antibacterial activity of GO in concentration and time-dependent experiments. Further annotation of the fingerprinting spectra shows the variabilities of important metabolites such as phosphatidylethanolamine, phosphatidylglycerol and glutathione. This metabolic perturbation of E. coli indicates cell membrane destruction and oxidative stress mechanisms for anti-bacteria activity of graphene oxide. It is anticipated that this mass spectrometry-based metabolite fingerprinting method will be applicable to other antibacterial nanomaterials and provide more clues as to their antibacterial mechanism at molecular level. PMID:27306507

  17. Influence of age and caloric restriction on liver glycolytic enzyme activities and metabolite concentrations in mice.

    PubMed

    Hagopian, Kevork; Ramsey, Jon J; Weindruch, Richard

    2003-03-01

    The influence of caloric restriction (CR) from 2 months of age on the activities of liver glycolytic enzymes and metabolite levels was studied in young and old mice. Livers were sampled 48 h after the last scheduled feeding time. Old mice on CR showed significant decreases in the activities of all the enzymes studied, except for aldolase, triosephosphate isomerase and phosphoglycerate mutase, which were unchanged. The metabolites glucose, glucose-6-phosphate, fructose-6-phosphate, pyruvate and lactate were lower while fructose-1,6-bisphosphate, glyceraldehyde-3-phosphate, dihydroxyacetone phosphate, 3-phosphoglycerate and phosphoenolpyruvate were increased in old CR. Young mice on CR also showed reduced enzyme activities, except for aldolase, triosephosphate isomerase and enolase which were unchanged when compared with young controls. The metabolites glucose, glucose-6-phosphate, fructose-6-phosphate and pyruvate were decreased when compared with young controls, while phosphoenolpyruvate was increased. Ketone bodies increased (65%) in old, but not young, CR mice while fructose-2,6-bisphosphate decreased in both young (22%) and old CR (28%) mice. The results indicate that decreased hepatic glucose levels in CR mice are associated with decreased enzyme activities but not a uniform decrease in metabolite levels. Increased ketone body levels indicate increased utilization of non-carbohydrate fuels while decreased fructose-2,6-bisphosphate level suggests its importance in the control of glycolysis in CR. PMID:12581789

  18. Oral administration of active vitamin D metabolites to low birthweight infants.

    PubMed Central

    Kovar, I Z; Mayne, P D; James, J J; Barnes, I C

    1986-01-01

    The active vitamin D metabolites 1 alpha, 25-dihydroxycholecalciferol (Rocaltrol) and the analogue 1 alpha-hydroxycholecalciferol (One-Alpha) are adequately absorbed after oral administration in the preterm infant. The absorption pattern is similar to that seen in adults. PMID:3755581

  19. Rapidly Probing Antibacterial Activity of Graphene Oxide by Mass Spectrometry-based Metabolite Fingerprinting.

    PubMed

    Zhang, Ning; Hou, Jian; Chen, Suming; Xiong, Caiqiao; Liu, Huihui; Jin, Yulong; Wang, Jianing; He, Qing; Zhao, Rui; Nie, Zongxiu

    2016-01-01

    Application of nanomaterials as anti-bacteria agents has aroused great attention. To investigate the antibacterial activity and antibacterial mechanism of nanomaterials from a molecular perspective is important for efficient developing of nanomaterial antibiotics. In the current work, a new mass spectrometry-based method was established to investigate the bacterial cytotoxicity of graphene oxide (GO) by the metabolite fingerprinting of microbes. The mass spectra of extracted metabolites from two strains DH5α and ATCC25922 were obtained before and after the incubation with nanomaterials respectively. Then principal component analysis (PCA) of these spectra was performed to reveal the relationship between the metabolism disorder of microbes and bactericidal activity of GO. A parameter "D" obtained from PCA scores was proposed that is capable to quantitatively evaluate the antibacterial activity of GO in concentration and time-dependent experiments. Further annotation of the fingerprinting spectra shows the variabilities of important metabolites such as phosphatidylethanolamine, phosphatidylglycerol and glutathione. This metabolic perturbation of E. coli indicates cell membrane destruction and oxidative stress mechanisms for anti-bacteria activity of graphene oxide. It is anticipated that this mass spectrometry-based metabolite fingerprinting method will be applicable to other antibacterial nanomaterials and provide more clues as to their antibacterial mechanism at molecular level. PMID:27306507

  20. CHARACTERIZATION ADN BIOLOGICAL ACTIVITY OF SECONDARY METABOLITES FROM ARMILLARIA TABESCENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ethyl acetate extracts from liquid cultures of Armillaria tabescens showed good antimicrobial activity against Candida albicans, Cryptococcus neoformans, Escherichia coli and Mycobacterium intracellulare. Chemical analyses of extract constituents led to the isolation and identification of two new co...

  1. Mixture toxicity of the antiviral drug Tamiflu((R)) (oseltamivir ethylester) and its active metabolite oseltamivir acid.

    PubMed

    Escher, Beate I; Bramaz, Nadine; Lienert, Judit; Neuwoehner, Judith; Straub, Jürg Oliver

    2010-02-18

    Tamiflu (oseltamivir ethylester) is an antiviral agent for the treatment of influenza A and B. The pro-drug Tamiflu is converted in the human body to the pharmacologically active metabolite, oseltamivir acid, with a yield of 75%. Oseltamivir acid is indirectly photodegradable and slowly biodegradable in sewage works and sediment/water systems. A previous environmental risk assessment has concluded that there is no bioaccumulation potential of either of the compounds. However, little was known about the ecotoxicity of the metabolite. Ester hydrolysis typically reduces the hydrophobicity and thus the toxicity of a compound. In this case, a zwitterionic, but overall neutral species is formed from the charged parent compound. If the speciation and predicted partitioning into biological membranes is considered, the metabolite may have a relevant contribution to the overall toxicity. These theoretical considerations triggered a study to investigate the toxicity of oseltamivir acid (OA), alone and in binary mixtures with its parent compound oseltamivir ethylester (OE). OE and OA were found to be baseline toxicants in the bioluminescence inhibition test with Vibrio fischeri. Their mixture effect lay between predictions for concentration addition and independent action for the mixture ratio excreted in urine and nine additional mixture ratios of OE and OA. In contrast, OE was an order of magnitude more toxic than OA towards algae, with a more pronounced effect when the direct inhibition of photosystem II was used as toxicity endpoint opposed to the 24h growth rate endpoint. The binary mixtures in this assay yielded experimental mixture effects that agreed with predictions for independent action. This is consistent with the finding that OE exhibits slightly enhanced toxicity, while OA acts as baseline toxicant. Therefore, with respect to mixture classification, the two compounds can be considered as acting according to different modes of toxic action, although there are

  2. Effect of aposymbiotic conditions on colony growth and secondary metabolite production in the lichen-forming fungus Ramalina dilacerata.

    PubMed

    Timsina, Brinda A; Sorensen, John L; Weihrauch, Dirk; Piercey-Normore, Michele D

    2013-01-01

    The production of secondary metabolites by aposymbiotic lichen-forming fungi in culture is thought to be influenced by environmental conditions. The effects of the environment may be studied by culturing fungi under defined growing parameters to provide a better understanding of the role of the large number of polyketide synthase (PKS) gene paralogs detected in the genomes of many fungi. The objectives of this study were to examine the effects of culture conditions (media composition and pH level) on the colony growth, the numbers of secondary products, and the expression of two PKS genes by the lichen-forming fungus Ramalina dilacerata. Four types of growth media at four different pH levels were prepared to culture spore isolates of R. dilacerata. Colony diameter and texture were recorded. The number of secondary compounds were determined by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Expression of two PKS genes (non-reducing (NR) and 6-MSAS-type PKS) were compared with expression of an internal control mitochondrial small subunit gene (mtSSU). The results showed that media containing yeast extracts produced the largest colony diameters and the fewest number of secondary metabolites. Colony growth rates also varied with different media conditions, and a significant negative relationship occurred between colony diameter and number of secondary metabolites. Expression of the NR PKS gene was significantly higher at pH 6.5 on the glucose malt agar than any other media, and expression of the 6-MSAS-type (partially-reducing) PKS gene was significantly higher at pH 8.5 on (malt agar) malt agar than on the other types of agar. Gene expression was correlated with the pH level and media conditions that induced the production of the larger number of secondary substances. This is the first study to examine secondary metabolite production in R. dilacerata by comparing the number of polyketides detected with quantitative polymerase chain

  3. Secondary Metabolites Produced by an Endophytic Fungus Pestalotiopsis sydowiana and Their 20S Proteasome Inhibitory Activities.

    PubMed

    Xia, Xuekui; Kim, Soonok; Liu, Changheng; Shim, Sang Hee

    2016-01-01

    Fungal endophytes have attracted attention due to their functional diversity. Secondary metabolites produced by Pestalotiopsis sydowiana from a halophyte, Phragmites communis Trinus, were investigated. Eleven compounds, including four penicillide derivatives (1-4) and seven α-pyrone analogues (5-10) were isolated from cultures of P. sydowiana. The compounds were identified based on spectroscopic data. The inhibitory activities against the 20S proteasome were evaluated. Compounds 1-3, 5, and 9-10 showed modest proteasome inhibition activities, while compound 8 showed strong activity with an IC50 of 1.2 ± 0.3 μM. This is the first study on the secondary metabolites produced by P. sydowiana and their proteasome inhibitory activities. The endophytic fungus P. sydowiana might be a good resource for proteasome inhibitors. PMID:27447600

  4. Colon cancer chemopreventive effects of baicalein, an active enteric microbiome metabolite from baicalin

    PubMed Central

    WANG, CHONG-ZHI; ZHANG, CHUN-FENG; CHEN, LINA; ANDERSON, SAMANTHA; LU, FANG; YUAN, CHUN-SU

    2015-01-01

    Baicalin is a major constituent of Scutellaria baicalensis, which is a commonly used herbal medicine in many Asian countries. After oral ingestion, intestinal micro-biota metabolism may change parent compound's structure and its biological activities. However, whether baicalin can be metabolized by enteric microbiota and the related anti-cancer activity is not clear. In this study, using human enteric microbiome incubation and HPLC analysis, we observed that baicalin can be quickly converted to baicalein. We compared the antiproliferative effects of baicalin and baicalein using a panel of human cancer cell lines, including three human colorectal cancer (CRC) cell lines. In vitro antiproliferative effects on CRC cells were verified using an in vivo xenograft nude mouse model. Baicalin showed limited antiproliferative effects on some of these cancer cell lines. Baicalein, however, showed significant antiproliferative effects in all the tested cancer cell lines, especially on HCT-116 human colorectal cancer cells. In vivo antitumor results supported our in vitro data. We demonstrated that baicalein exerts potent S phase cell cycle arrest and pro-apoptotic effects in HCT-116 cells. Baicalein induced the activation of caspase 3 and 9. The in silico modeling suggested that baicalein forms hydrogen bonds with residues Ser251 and Asp253 at the active site of caspase 3, while interactions with residues Leu227 and Asp228 in caspase 9 through its hydroxyl groups. Data from this study suggested that baicalein is a potent anticancer metabolite derived from S. baicalensis. Enteric microbiota play a key role in the colon cancer chemoprevention of S. baicalensis. PMID:26398706

  5. Unexpected hormonal activity of a catechol equine estrogen metabolite reveals reversible glutathione conjugation

    PubMed Central

    Peng, Kuan-Wei; Chang, Minsun; Wang, Yue-Ting; Wang, Zhican; Qin, Zhihui; Bolton, Judy L.; Thatcher, Gregory R. J.

    2010-01-01

    4-Hydroxyequilenin (4-OHEN) is a major phase I metabolite of the equine estrogens present in widely prescribed hormone replacement formulations. 4-OHEN is autoxidized to an electrophilic o-quinone that has been shown to redox cycle, generating ROS, and to covalently modify proteins and DNA and thus potentially to act as a chemical carcinogen. To establish the ability of 4-OHEN to act as a hormonal carcinogen at the estrogen receptor (ER), estrogen responsive gene expression and proliferation were studied in ER(+) breast cancer cells. Recruitment by 4-OHEN of ER to estrogen responsive elements (ERE) of DNA in MCF-7 cells was also studied and observed. 4-OHEN was a potent estrogen, with additional weak activity associated with binding to the arylhydrocarbon receptor (AhR). The potency of 4-OHEN towards classical ERα mediated activity was unexpected given the reported rapid autoxidation and trapping of the resultant quinone by GSH. Addition of thiols to cell cultures did not attenuate the estrogenic activity of 4-OHEN and pre-formed thiol conjugates added to cell incubations only marginally reduced ERE-luciferase induction. On reaction of the 4OHEN-GSH conjugate with NADPH, 4-OHEN was observed to be regenerated at a rate dependent upon NADPH concentration, indicating that intracellular non-enzymatic and enzymatic regeneration of 4-OHEN accounts for the observed estrogenic activity of 4-OHEN. 4-OHEN is therefore capable of inducing chemical and hormonal pathways that may contribute to estrogen-dependent carcinogenesis, and trapping by cellular thiols does not provide a mechanism of termination of these pathways. PMID:20540524

  6. Antifouling Activity of Lipidic Metabolites Derived from Padina tetrastromatica.

    PubMed

    Suresh, Murugan; Iyapparaj, Palanisamy; Anantharaman, Perumal

    2016-07-01

    An attempt has been made to identify the potential seaweed for antifouling property due to the growing need for environmentally safe antifouling systems. The antibacterial, antimicroalgal, and antimussel foot adherence potentials of methanol, dichloromethane, and hexane extracts of the chosen seaweeds such as Padina tetrastromatica, Caulerpa taxifolia, and Amphiroa fragilissima have been compared against copper sulfate. Among the extracts, the maximum antibacterial activities were exhibited by the methanol extract of P. tetrastromatica. The minimum inhibitory concentration (MIC) of the methanolic extract of P. tetrastromatica was found to be 10 and 1 μg/ml against test biofilm bacteria and diatoms, respectively. The antimussel foot adherence assay indicated that the extract had inhibited the foot adherence of the green mussels Perna viridis with the effective concentration (EC50) of 25.51 ± 0.03 μg/ml, and lethal concentration for 50 % mortality (LC50) was recorded at 280.22 ± 0.12 μg/ml. Based on the prolific results, the crude methanolic extract of P. tetrastromatica was subjected to purification using silica gel column and thin-layer chromatography (TLC). Then, the active compounds of the bioassay-guided fraction (F13) were identified using gas chromatography coupled with mass spectroscopy (GC-MS), and it was observed that fatty acids were the major components, which may be responsible for the antifouling properties. PMID:26956575

  7. Antitumor Activity of Hierridin B, a Cyanobacterial Secondary Metabolite Found in both Filamentous and Unicellular Marine Strains

    PubMed Central

    Ramos, Vitor; Pereira, Alban R.; Fernandes, Virgínia C.; Domingues, Valentina F.; Gerwick, William H.; Vasconcelos, Vitor M.; Martins, Rosário

    2013-01-01

    Cyanobacteria are widely recognized as a valuable source of bioactive metabolites. The majority of such compounds have been isolated from so-called complex cyanobacteria, such as filamentous or colonial forms, which usually display a larger number of biosynthetic gene clusters in their genomes, when compared to free-living unicellular forms. Nevertheless, picocyanobacteria are also known to have potential to produce bioactive natural products. Here, we report the isolation of hierridin B from the marine picocyanobacterium Cyanobium sp. LEGE 06113. This compound had previously been isolated from the filamentous epiphytic cyanobacterium Phormidium ectocarpi SAG 60.90, and had been shown to possess antiplasmodial activity. A phylogenetic analysis of the 16S rRNA gene from both strains confirmed that these cyanobacteria derive from different evolutionary lineages. We further investigated the biological activity of hierridin B, and tested its cytotoxicity towards a panel of human cancer cell lines; it showed selective cytotoxicity towards HT-29 colon adenocarcinoma cells. PMID:23922738

  8. Global metabolite analysis of the land snail Theba pisana hemolymph during active and aestivated states.

    PubMed

    Bose, U; Centurion, E; Hodson, M P; Shaw, P N; Storey, K B; Cummins, S F

    2016-09-01

    The state of metabolic dormancy has fascinated people for hundreds of years, leading to research exploring the identity of natural molecular components that may induce and maintain this state. Many animals lower their metabolism in response to high temperatures and/or arid conditions, a phenomenon called aestivation. The biological significance for this is clear; by strongly suppressing metabolic rate to low levels, animals minimize their exposure to stressful conditions. Understanding blood or hemolymph metabolite changes that occur between active and aestivated animals can provide valuable insights relating to those molecular components that regulate hypometabolism in animals, and how they afford adaptation to their different environmental conditions. In this study, we have investigated the hemolymph metabolite composition from the land snail Theba pisana, a remarkably resilient mollusc that displays an annual aestivation period. Using LC-MS-based metabolomics analysis, we have identified those hemolymph metabolites that show significant changes in relative abundance between active and aestivated states. We show that certain metabolites, including some phospholipids [e.g. LysoPC(14:0)], and amino acids such as l-arginine and l-tyrosine, are present at high levels within aestivated snails. Further investigation of our T. pisana RNA-sequencing data elucidated the entire repertoire of phospholipid-synthesis genes in the snail digestive gland, as a precursor towards future comparative investigation between the genetic components of aestivating and non-aestivating species. In summary, we have identified a large number of metabolites that are elevated in the hemolymph of aestivating snails, supporting their role in protecting against heat or desiccation. PMID:27318654

  9. Culture condition-dependent metabolite profiling of Aspergillus fumigatus with antifungal activity.

    PubMed

    Kang, Daejung; Son, Gun Hee; Park, Hye Min; Kim, Jiyoung; Choi, Jung Nam; Kim, Hyang Yeon; Lee, Sarah; Hong, Seung-Beom; Lee, Choong Hwan

    2013-03-01

    Three sections of Aspergillus (five species, 21 strains) were classified according to culture medium-dependent and time-dependent secondary metabolite profile-based chemotaxonomy. Secondary metabolites were analysed by liquid chromatography-electrospray ionisation tandem mass spectrometry (LC-ESI-MS-MS) and multivariate statistical methods. From the Aspergillus sections that were cultured on malt extract agar (MEA) and Czapek yeast extract agar (CYA) for 7, 12, and 16 d, Aspergillus sections Fumigati (A. fumigatus), Nigri (A. niger), and Flavi (A. flavus, A. oryzae, and A. sojae) clustered separately on the basis of the results of the secondary metabolite analyses at 16 d regardless of culture medium. Based on orthogonal projection to latent structures discriminant analysis by partial least squares discriminant analysis (PLS-DA), we identified the secondary metabolites that helped differentiate sections between A. fumigatus and Aspergillus section Flavi to be gliotoxin G, fumigatin oxide, fumigatin, pseurotin A or D, fumiquinazoline D, fumagillin, helvolic acid, 1,2-dihydrohelvolic acid, and 5,8-dihydroxy-9,12-octadecadienoic acid (5,8-diHODE). Among these compounds, fumagillin, helvolic acid, and 1,2-dihydrohelvolic acid of A. fumigatus showed antifungal activities against Malassezia furfur, which is lipophilic yeast that causes epidermal skin disorders. PMID:23537878

  10. Channel-Forming Activities in the Glycosomal Fraction from the Bloodstream Form of Trypanosoma brucei

    PubMed Central

    Miinalainen, Ilkka J.; Hiltunen, J. Kalervo; Michels, Paul A. M.; Antonenkov, Vasily D.

    2012-01-01

    Background Glycosomes are a specialized form of peroxisomes (microbodies) present in unicellular eukaryotes that belong to the Kinetoplastea order, such as Trypanosoma and Leishmania species, parasitic protists causing severe diseases of livestock and humans in subtropical and tropical countries. The organelles harbour most enzymes of the glycolytic pathway that is responsible for substrate-level ATP production in the cell. Glycolysis is essential for bloodstream-form Trypanosoma brucei and enzymes comprising this pathway have been validated as drug targets. Glycosomes are surrounded by a single membrane. How glycolytic metabolites are transported across the glycosomal membrane is unclear. Methods/Principal Findings We hypothesized that glycosomal membrane, similarly to membranes of yeast and mammalian peroxisomes, contains channel-forming proteins involved in the selective transfer of metabolites. To verify this prediction, we isolated a glycosomal fraction from bloodstream-form T.brucei and reconstituted solubilized membrane proteins into planar lipid bilayers. The electrophysiological characteristics of the channels were studied using multiple channel recording and single channel analysis. Three main channel-forming activities were detected with current amplitudes 70–80 pA, 20–25 pA, and 8–11 pA, respectively (holding potential +10 mV and 3.0 M KCl as an electrolyte). All channels were in fully open state in a range of voltages ±150 mV and showed no sub-conductance transitions. The channel with current amplitude 20–25 pA is anion-selective (PK+/PCl−∼0.31), while the other two types of channels are slightly selective for cations (PK+/PCl− ratios ∼1.15 and ∼1.27 for the high- and low-conductance channels, respectively). The anion-selective channel showed an intrinsic current rectification that may suggest a functional asymmetry of the channel's pore. Conclusions/Significance These results indicate that the membrane of glycosomes apparently

  11. Reproductive activity in the peninsular pronghorn determined from excreted gonadal steroid metabolites.

    PubMed

    Kersey, David C; Holland, Jeff; Eng, Curtis

    2015-01-01

    Fecal hormone monitoring was employed to better define annual patterns of reproductive steroid metabolites from a breeding pair of peninsular pronghorn (Antilocapra americana peninsularis) maintained at the Los Angeles Zoo. Notably in the female, increased excretion of estrogen metabolites occurred during the breeding season (Jun-Aug), and a biphasic pattern in progestagen activity was measured during gestation. Of additional interest, a preterm increase in estrogen that continued for an additional 64 days post partum. Male androgen activity correlated with the female estrogen patterns, with a single successful copulation occurring during the breeding season; interestingly however, the male exhibited no reproductive behaviors during the female's preterm/post partum estrogen increase. These data are the first reproductive steroid profiles for the peninsular pronghorn and provide valuable insight that will aid efforts that link the species' reproductive physiology with conservation management. PMID:25652944

  12. Secondary metabolites of plants from the genus chloranthus: chemistry and biological activities.

    PubMed

    Wang, An-Ran; Song, Hong-Chuan; An, Hong-Mei; Huang, Qian; Luo, Xie; Dong, Jin-Yan

    2015-04-01

    Chloranthus, a genus of the family Chloranthaceae, which is mainly distributed in eastern and southern Asia, has been used in Chinese folk medicine due to its antitumor, antifungal, and anti-inflammatory activities. This review compiles the research on isolation, structure elucidation, structural diversity, and bioactivities of Chloranthus secondary metabolites reported between 2007 and 2013. The metabolites listed encompass 82 sesquiterpenoids, 50 dimeric sesquiterpenoids, 15 diterpenoids, one coumarin, and five other compounds. Among them, dimeric sesquiterpenoids, the characteristic components of plants from the genus Chloranthus, have attracted considerable attention due to their complex structures and significant biological features, e.g., antitumor, antibacterial, antifungal, anti-inflammatory, and hepatoprotective activities, and potent and selective inhibition of the delayed rectifier (IK) K(+) current and tyrosinase. PMID:25879494

  13. Aryl Hydrocarbon Receptor Activity of Tryptophan Metabolites in Young Adult Mouse Colonocytes.

    PubMed

    Cheng, Yating; Jin, Un-Ho; Allred, Clint D; Jayaraman, Arul; Chapkin, Robert S; Safe, Stephen

    2015-10-01

    The tryptophan microbiota metabolites indole-3-acetate, indole-3-aldehyde, indole, and tryptamine are aryl hydrocarbon receptor (AhR) ligands, and in this study we investigated their AhR agonist and antagonist activities in nontransformed young adult mouse colonocyte (YAMC) cells. Using Cyp1a1 mRNA as an Ah-responsive end point, we observed that the tryptophan metabolites were weak AhR agonists and partial antagonists in YAMC cells, and the pattern of activity was different from that previously observed in CaCo2 colon cancer cells. However, expansion of the end points to other Ah-responsive genes including the Cyp1b1, the AhR repressor (Ahrr), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible poly(ADP-ribose) polymerase (TiParp) revealed a highly complex pattern of AhR agonist/antagonist activities that were both ligand- and gene-dependent. For example, the magnitude of induction of Cyp1b1 mRNA was similar for TCDD, tryptamine, and indole-3-acetate, whereas lower induction was observed for indole and indole-3-aldehyde was inactive. These results suggest that the tryptophan metabolites identified in microbiota are selective AhR modulators. PMID:25873348

  14. Oxidation of propylthiouracil to reactive metabolites by activated neutrophils. Implications for agranulocytosis.

    PubMed

    Waldhauser, L; Uetrecht, J

    1991-01-01

    Propylthiouracil (PTU) is associated with idiosyncratic agranulocytosis that may be due to reactive metabolites generated from oxidative metabolism by neutrophils. Therefore, the metabolism of PTU was investigated in activated neutrophils. Three oxidized metabolites were observed on HPLC: PTU-disulfide, propyluracil-2-sulfinate, and propyluracil-2-sulfonate (PTU-SO3-). No metabolism was detected in cells that had not been activated. Metabolism was inhibited by sodium azide and by catalase. The same products were produced by myeloperoxidase (MPO) in an MPO/H2O2/Cl- system. PTU inhibited its own metabolism; however, complete conversion to PTU-SO3- could be achieved with optimal PTU concentrations. MPO/H2O2 without Cl- produced only slight metabolism. The PTU-sulfenyl chloride is a postulated intermediate. In the absence of chloride, oxidation might proceed through propyluracil-2-sulfenic acid. The sulfenyl chloride and PTU-SO3- are both chemically reactive with sulfhydryl compounds such as N-acetylcysteine. Such reactive metabolites, generated by activated neutrophils, may be involved in hypersensitivity reactions associated with PTU, such as agranulocytosis. PMID:1676636

  15. Fungal transformation and T-cell proliferation inhibitory activity of melengestrol acetate and its metabolite.

    PubMed

    Baydoun, Elias; Bano, Saira; Atia-tul-Wahab; Jabeen, Almas; Yousuf, Sammer; Mesaik, Ahmed; Smith, Colin; Choudhary, M Iqbal

    2014-08-01

    Biotransformation of melengestrol acetate (MGA, 17α-acetoxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione) (1) was investigated for the first time by using fungal cultures. Incubation of compound 1 with Cunninghamella blakesleeana yielded a new major metabolite, 17α-acetoxy-11β-hydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2). The metabolite 2 was purified by using HPLC, followed by characterization through (1)H- and (13)C-NMR and other spectroscopic techniques. Single crystal X-ray diffraction analysis was used to deduce the three dimensional structures of melengestrol acetate (1) and metabolite 2 for the first time. T-cell proliferation assay was employed to evaluate the immunosuppressant effect of compounds 1 and 2 with IC50=0.5±0.07 and 0.6±0.08μg/mL, respectively. The results indicated that these compounds possess sixfold potent T-cell proliferation inhibitory activity as compared to the standard prednisolone (IC50<3.1μg/mL). Both compounds were found to be non-toxic in a 3T3 (mouse fibroblast) cell-based cytotoxicity assay. This discovery of potent anti-inflammatory activity of compounds 1 and 2 can lead the way to develop new immunosuppressant compounds for clinical application. PMID:24793568

  16. Marine Invertebrate Metabolites with Anticancer Activities: Solutions to the "Supply Problem".

    PubMed

    Gomes, Nelson G M; Dasari, Ramesh; Chandra, Sunena; Kiss, Robert; Kornienko, Alexander

    2016-05-01

    Marine invertebrates provide a rich source of metabolites with anticancer activities and several marine-derived agents have been approved for the treatment of cancer. However, the limited supply of promising anticancer metabolites from their natural sources is a major hurdle to their preclinical and clinical development. Thus, the lack of a sustainable large-scale supply has been an important challenge facing chemists and biologists involved in marine-based drug discovery. In the current review we describe the main strategies aimed to overcome the supply problem. These include: marine invertebrate aquaculture, invertebrate and symbiont cell culture, culture-independent strategies, total chemical synthesis, semi-synthesis, and a number of hybrid strategies. We provide examples illustrating the application of these strategies for the supply of marine invertebrate-derived anticancer agents. Finally, we encourage the scientific community to develop scalable methods to obtain selected metabolites, which in the authors' opinion should be pursued due to their most promising anticancer activities. PMID:27213412

  17. Marine Invertebrate Metabolites with Anticancer Activities: Solutions to the “Supply Problem”

    PubMed Central

    Gomes, Nelson G. M.; Dasari, Ramesh; Chandra, Sunena; Kiss, Robert; Kornienko, Alexander

    2016-01-01

    Marine invertebrates provide a rich source of metabolites with anticancer activities and several marine-derived agents have been approved for the treatment of cancer. However, the limited supply of promising anticancer metabolites from their natural sources is a major hurdle to their preclinical and clinical development. Thus, the lack of a sustainable large-scale supply has been an important challenge facing chemists and biologists involved in marine-based drug discovery. In the current review we describe the main strategies aimed to overcome the supply problem. These include: marine invertebrate aquaculture, invertebrate and symbiont cell culture, culture-independent strategies, total chemical synthesis, semi-synthesis, and a number of hybrid strategies. We provide examples illustrating the application of these strategies for the supply of marine invertebrate-derived anticancer agents. Finally, we encourage the scientific community to develop scalable methods to obtain selected metabolites, which in the authors’ opinion should be pursued due to their most promising anticancer activities. PMID:27213412

  18. Biologically active polyketide metabolites from an undetermined fungicolous hyphomycete resembling Cladosporium.

    PubMed

    Höller, Ulrich; Gloer, James B; Wicklow, Donald T

    2002-06-01

    Eight new polyketide-derived metabolites [cladoacetals A and B (1 and 2), 3-(2-formyl-3-hydroxyphenyl)propionic acid (3), 3-deoxyisoochracinic acid (4), isoochracinol (5), 7-hydroxy-3-(2,3-dihydroxybutyl)-1(3H)-isobenzofuranone (6), (+)-cyclosordariolone (10), and altersolanol J (11)] and six known metabolites [two isomeric 1-(1,3-dihydro-4-hydroxy-1-isobenzofuranyl)butan-2,3-diols (7a/b), 7-hydroxy-1(3H)-isobenzofuranone (8), isoochracinic acid (9), altersolanol A (12), and macrosporin (13)] have been isolated from solid-substrate fermentation cultures of an undetermined fungicolous isolate (NRRL 29097) that resembles Cladosporium sp. All structures were assigned primarily by analysis of 1D and/or 2D NMR data. Five of the compounds showed antibacterial activity. PMID:12088431

  19. Microbial transformation of (+)-nootkatone and the antiproliferative activity of its metabolites.

    PubMed

    Gliszczyńska, Anna; Łysek, Agnieszka; Janeczko, Tomasz; Świtalska, Marta; Wietrzyk, Joanna; Wawrzeńczyk, Czesław

    2011-04-01

    Six metabolites were obtained as a result of microbial transformation of (+)-nootkatone (1) by the fungal strains: Botrytis, Didymosphaeria, Aspergillus, Chaetomium and Fusarium. Their structure were established as (+)-(4R,5S,7R,9R)-9α-hydroxynootkatone (2), (+)-(4R,5S,7R)-13-hydroxynootkatone (3) and (+)-(4R,5S,7R,9R,11S)-11,12-epoxy-9α-hydroxynootkatone (4), (+)-(4R,5S,7R,11S)-11,12-epoksynootkatone (5), (+)-(4R,5S,7R)-11,12-dihydroxynootkatone (6) and (+)-(4R,5S,7R)-7,11,12-trihydroxynootkatone (7) on the basis of their spectral data. Two products: (4) and (7) were not previously reported in the literature. The antiproliferative activity of (+)-nootkatone (1) and isolated metabolites (2-7) of its biotransformation has been evaluated. PMID:21377882

  20. Evaluation of the pharmacological activity of the major mexiletine metabolites on skeletal muscle sodium currents

    PubMed Central

    De Bellis, M; De Luca, A; Rana, F; Cavalluzzi, M M; Catalano, A; Lentini, G; Franchini, C; Tortorella, V; Conte Camerino, D

    2006-01-01

    Background and purpose: Mexiletine (Mex), an orally effective antiarrhythmic agent used to treat ventricular arrhythmias, has also been found to be effective for myotonia and neuropathic pain. It is extensively metabolized in humans but little information exists about the pharmacodynamic properties of its metabolites. Experimental approach: To determine their contribution to the clinical activity of Mex, p-hydroxy-mexiletine (PHM), hydroxy-methyl-mexiletine (HMM), N-hydroxy-mexiletine (NHM) (phase I reaction products) and N-carbonyloxy β-D-glucuronide (NMG) (phase II reaction product) were tested on sodium currents (INa) of frog skeletal muscle fibres. Sodium currents were elicited with depolarizing pulses from different holding potentials (HP=−140, −100, −70 mV) and stimulation frequencies (0.25, 0.5, 1, 2, 5, 10 Hz) using the vaseline-gap voltage-clamp method. Key results: All the hydroxylated derivatives blocked the sodium channel in a voltage- and use-dependent manner. The PHM, HMM and NHM metabolites were up to 10-fold less effective than the parent compound. However, HMM showed a greater use-dependent behaviour (10 Hz), compared to Mex and the other metabolites. Similar to Mex, these products behaved as inactivating channel blockers. Conjugation with glucuronic acid (NMG) resulted in almost complete abolition of the pharmacological activity of the parent compound. Conclusions and Implications: Thus, although less potent, the phase I metabolites tested demonstrated similar pharmacological behaviour to Mex and might contribute to its clinical profile. PMID:16921388

  1. Antimicrobial activity of secondary metabolites from Streptomyces sp. K15, an endophyte in Houttuynia cordata Thunb.

    PubMed

    Chen, Huabao; Yang, Chunping; Ke, Tao; Zhou, Miaomiao; Li, Zhaojun; Zhang, Min; Gong, Guoshu; Hou, Taiping

    2015-01-01

    We isolated Streptomyces sp. K15 from the root tissue of Houttuynia cordata Thunb and found that some of its secondary metabolites exhibited significant antimicrobial activity against Botrytis cinerea. Moreover, we separated, purified and identified the major active ingredient to be 2-pyrrol formic acid by using silica gel column chromatography, high-performance liquid chromatography and NMR analysis of the spectral data. 2-Pyrrol formic acid critically inhibited the growth of some phytopathogenic bacteria. Therefore, it has potential value in agricultural applications. PMID:25675117

  2. Triterpenoid resinous metabolites from the genus Boswellia: pharmacological activities and potential species-identifying properties

    PubMed Central

    2013-01-01

    The resinous metabolites commonly known as frankincense or olibanum are produced by trees of the genus Boswellia and have attracted increasing popularity in Western countries in the last decade for their various pharmacological activities. This review described the pharmacological specific details mainly on anti-inflammatory, anti-carcinogenic, anti-bacterial and apoptosis-regulating activities of individual triterpenoid together with the relevant mechanism. In addition, species-characterizing triterpenic markers with the methods for their detection, bioavailability, safety and other significant properties were reviewed for further research. PMID:24028654

  3. Activation of the aryl hydrocarbon receptor by carcinogenic aromatic amines and modulatory effects of their N-acetylated metabolites.

    PubMed

    Juricek, Ludmila; Bui, Linh-Chi; Busi, Florent; Pierre, Stéphane; Guyot, Erwan; Lamouri, Aazdine; Dupret, Jean-Marie; Barouki, Robert; Coumoul, Xavier; Rodrigues-Lima, Fernando

    2015-12-01

    Aromatic amines (AAs) are an important class of chemicals which account for 12 % of known carcinogens. The biological effects of AAs depend mainly on their biotransformation into reactive metabolites or into N-acetylated metabolites which are generally considered as less toxic. Although the activation of the aryl hydrocarbon receptor (AhR) pathway by certain carcinogenic AAs has been reported, the effects of their N-acetylated metabolites on the AhR have not been addressed. Here, we investigated whether carcinogenic AAs and their N-acetylated metabolites may activate/modulate the AhR pathway in the absence and/or the presence of a bona fide AhR ligand (benzo[a]pyrene/B(a)P]. In agreement with previous studies, we found that certain AAs activated the AhR in human liver and lung cells as assessed by an increase in cytochrome P450 1A1 (CYP1A1) expression and activity. Altogether, we report for the first time that these properties can be modulated by the N-acetylation status of the AA. Whereas 2-naphthylamine significantly activated the AhR and induced CYP1A1 expression, its N-acetylated metabolite was less efficient. In contrast, the N-acetylated metabolite of 2-aminofluorene was able to significantly activate AhR, whereas the parent AA, 2-aminofluorene, did not. In the presence of B(a)P, activation of AhR or antagonist effects were observed depending on the AA or its N-acetylated metabolite. Activation and/or modulation of the AhR pathway by AAs and their N-acetylated metabolites may represent a novel mechanism contributing to the toxicological effects of AAs. More broadly, our data suggest biological interactions between AAs and other classes of xenobiotics through the AhR pathway. PMID:25224404

  4. Identification of metabolites from an active fraction of Cajanus cajan seeds by high resolution mass spectrometry.

    PubMed

    Tekale, Satishkumar S; Jaiwal, Bhimrao V; Padul, Manohar V

    2016-11-15

    Antioxidants are important food additives which prolong food storage due to their protective effects against oxidative degradation of foods by free radicals. However, the synthetic antioxidants show toxic properties. Alternative economical and eco-friendly approach is screening of plant extract for natural antioxidants. Plant phenolics are potent antioxidants. Hence, in present study Cajanus cajan seeds were analyzed for antioxidant activity, Iron chelating activity and total phenolic content. The antioxidant activity using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay showed 71.3% inhibition and 65.8% Iron chelating activity. Total 37 compounds including some short peptides and five major abundant compounds were identified in active fraction of C. cajan seeds. This study concludes that C. cajan seeds are good source of antioxidants and Iron chelating activity. Metabolites found in C. cajan seeds which remove reactive oxygen species (ROS), may help to alleviate oxidative stress associated dreaded health problem like cancer and cardiovascular diseases. PMID:27283694

  5. Active superconducting devices formed of thin films

    DOEpatents

    Martens, Jon S.; Beyer, James B.; Nordman, James E.; Hohenwarter, Gert K. G.

    1991-05-28

    Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions. The devices can be utilized for a variety of electrical components, including switching circuits, amplifiers, oscillators and modulators, and are well suited to microwave frequency applications.

  6. Select steroid hormone glucuronide metabolites can cause toll-like receptor 4 activation and enhanced pain.

    PubMed

    Lewis, Susannah S; Hutchinson, Mark R; Frick, Morin M; Zhang, Yingning; Maier, Steven F; Sammakia, Tarek; Rice, Kenner C; Watkins, Linda R

    2015-02-01

    We have recently shown that several classes of glucuronide metabolites, including the morphine metabolite morphine-3-glucuronide and the ethanol metabolite ethyl glucuronide, cause toll like receptor 4 (TLR4)-dependent signaling in vitro and enhanced pain in vivo. Steroid hormones, including estrogens and corticosterone, are also metabolized through glucuronidation. Here we demonstrate that in silico docking predicts that corticosterone, corticosterone-21-glucuronide, estradiol, estradiol-3-glucuronide and estradiol-17-glucuronide all dock with the MD-2 component of the TLR4 receptor complex. In addition to each docking with MD-2, the docking of each was altered by pre-docking with (+)-naloxone, a TLR4 signaling inhibitor. As agonist versus antagonist activity cannot be determined from these in silico interactions, an in vitro study was undertaken to clarify which of these compounds can act in an agonist fashion. Studies using a cell line transfected with TLR4, necessary co-signaling molecules, and a reporter gene revealed that only estradiol-3-glucuronide and estradiol-17-glucuronide increased reporter gene product, indicative of TLR4 agonism. Finally, in in vivo studies, each of the 5 drugs was injected intrathecally at equimolar doses. In keeping with the in vitro results, only estradiol-3-glucuronide and estradiol-17-glucuronide caused enhanced pain. For both compounds, pain enhancement was blocked by the TLR4 antagonist lipopolysaccharide from Rhodobacter sphaeroides, evidence for the involvement in TLR4 in the resultant pain enhancement. These findings have implications for several chronic pain conditions, including migraine and temporomandibular joint disorder, in which pain episodes are more likely in cycling females when estradiol is decreasing and estradiol metabolites are at their highest. PMID:25218902

  7. Select steroid hormone glucuronide metabolites can cause Toll-like receptor 4 activation and enhanced pain

    PubMed Central

    Lewis, Susannah S.; Hutchinson, Mark R.; Frick, Morin M.; Zhang, Yingning; Maier, Steven F.; Sammakia, Tarek; Rice, Kenner C.; Watkins, Linda R.

    2014-01-01

    We have recently shown that several classes of glucuronide metabolites, including the morphine metabolite morphine-3-glucuronide and the ethanol metabolite ethyl glucuronide, cause toll like receptor 4 (TLR4)-dependent signalling in vitro and enhanced pain in vivo. Steroid hormones, including estrogens and corticosterone, are also metabolized through glucuronidation. Here we demonstrate that in silico docking predicts that corticosterone, corticosterone-21-glucuronide, estradiol, estradiol-3-glucuronide and estradiol-17-glucuronide all dock with the MD-2 component of the TLR4 receptor complex. In addition to each docking with MD-2, the docking of each was altered by pre-docking with (+)-naloxone, a TLR4 signaling inhibitor. As agonist versus antagonist activity cannot be determined from these in silico interactions, an in vitro study was undertaken to clarify which of these compounds can act in an agonist fashion. Studies using a cell line transfected with TLR4, necessary co-signaling molecules, and a reporter gene revealed that only estradiol-3-glucuronide and estradiol-17-glucuronide increased reporter gene product, indicative of TLR4 agonism. Finally, in in vivo studies, each of the 5 drugs was injected intrathecally at equimolar doses. In keeping with the in vitro results, only estradiol-3-glucuronide and estradiol-17-glucuronide caused enhanced pain. For both compounds, pain enhancement was blocked by the TLR4 antagonist lipopolysaccharide from Rhodobacter sphaeroides, evidence for the involvement in TLR4 in the resultant pain enhancement. These findings have implications for several chronic pain conditions, including migraine and tempromandibular joint disorder, in which pain episodes are more likely in cycling females when estradiol is decreasing and estradiol metabolites are at their highest. PMID:25218902

  8. Biotransformation of dianabol with the filamentous fungi and β-glucuronidase inhibitory activity of resulting metabolites.

    PubMed

    Khan, Naik T; Zafar, Salman; Noreen, Shagufta; Al Majid, Abdullah M; Al Othman, Zeid A; Al-Resayes, Saud Ibrahim; Atta-ur-Rahman; Choudhary, M Iqbal

    2014-07-01

    Biotransformation of the anabolic steroid dianabol (1) by suspended-cell cultures of the filamentous fungi Cunninghamella elegans and Macrophomina phaseolina was studied. Incubation of 1 with C. elegans yielded five hydroxylated metabolites 2-6, while M. phaseolina transformed compound 1 into polar metabolites 7-11. These metabolites were identified as 6β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (2), 15α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (3), 11α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (4), 6β,12β,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (5), 6β,15α,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (6), 17β-hydroxy-17α-methylandrost-1,4-dien-3,6-dione (7), 7β,17β,-dihydroxy-17α-methylandrost-1,4-dien-3-one (8), 15β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (9), 17β-hydroxy-17α-methylandrost-1,4-dien-3,11-dione (10), and 11β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (11). Metabolite 3 was also transformed chemically into diketone 12 and oximes 13, and 14. Compounds 6 and 12-14 were identified as new derivatives of dianabol (1). The structures of all transformed products were deduced on the basis of spectral analyses. Compounds 1-14 were evaluated for β-glucuronidase enzyme inhibitory activity. Compounds 7, 13, and 14 showed a strong inhibition of β-glucuronidase enzyme, with IC50 values between 49.0 and 84.9 μM. PMID:24755238

  9. Regulation of human tonsillar T-cell proliferation by the active metabolite of vitamin D3.

    PubMed Central

    Nunn, J D; Katz, D R; Barker, S; Fraher, L J; Hewison, M; Hendy, G N; O'Riordan, J L

    1986-01-01

    We have examined the effects of 1,25(OH)2D3 on T-cell populations isolated by buoyant density and E rosetting from human tonsils. Cell proliferation was assessed by measuring the incorporation of 125iododeoxyuridine; interleukin-2 (IL-2) production was measured using an IL-2-dependent cell line, and the number of 1,25(OH)2D3 receptors was measured by whole-cell nuclear association assay. At a concentration of 10(-7) M, 1,25(OH)2D3 inhibited mitogen-induced T-cell proliferation in all E+ T-cell populations. This effect was more pronounced in the cells from the intermediate and high density layers and was reflected both in cell proliferative responses and in relative IL-2 synthesis. By adding the 1,25(OH)2D3 during the course of the mitogen assay, we demonstrated that activation of the T cell precedes the 1,25(OH)2D3-mediated inhibition. Cells that had been preincubated with mitogen in the presence of the 1,25(OH)2D3 were refractory to further stimulation by mitogens. Receptors for 1,25(OH)2D3 could not be detected in unstimulated T cells. However, activation led to the expression of high-affinity receptors for 1,25(OH)2D3. Co-incubation of the cells with mitogen and 1,25(OH)2D3 increased the number of receptors compared with mitogen alone. The effects provide further evidence for the hypothesis that 1,25(OH)2D3 is an important potential modulator of the immune system through its action on T cells. Taking our observations in conjunction with the known capacity of monocytes to hydroxylate the precursor metabolite (and thus synthesize the active form of cholecalciferol), the results support the suggestion that 1,25(OH)2D3 plays a role as a local mediator of mononuclear phagocyte-T cell interaction in human lymphomedullary tissues. PMID:3026959

  10. Low water activity induces the production of bioactive metabolites in halophilic and halotolerant fungi.

    PubMed

    Sepcic, Kristina; Zalar, Polona; Gunde-Cimerman, Nina

    2011-01-01

    The aim of the present study was to investigate indigenous fungal communities isolated from extreme environments (hypersaline waters of solar salterns and subglacial ice), for the production of metabolic compounds with selected biological activities: hemolysis, antibacterial, and acetylcholinesterase inhibition. In their natural habitats, the selected fungi are exposed to environmental extremes, and therefore the production of bioactive metabolites was tested under both standard growth conditions for mesophilic microorganisms, and at high NaCl and sugar concentrations and low growth temperatures. The results indicate that selected halotolerant and halophilic species synthesize specific bioactive metabolites under conditions that represent stress for non-adapted species. Furthermore, adaptation at the level of the chemical nature of the solute lowering the water activity of the medium was observed. Increased salt concentrations resulted in higher hemolytic activity, particularly within species dominating the salterns. The appearance of antibacterial potential under stress conditions was seen in the similar pattern of fungal species as for hemolysis. The active extracts exclusively affected the growth of the Gram-positive bacterium tested, Bacillus subtilis. None of the extracts tested showed inhibition of acetylcholinesterase activity. PMID:21339946

  11. Low Water Activity Induces the Production of Bioactive Metabolites in Halophilic and Halotolerant Fungi

    PubMed Central

    Sepcic, Kristina; Zalar, Polona; Gunde-Cimerman, Nina

    2011-01-01

    The aim of the present study was to investigate indigenous fungal communities isolated from extreme environments (hypersaline waters of solar salterns and subglacial ice), for the production of metabolic compounds with selected biological activities: hemolysis, antibacterial, and acetylcholinesterase inhibition. In their natural habitats, the selected fungi are exposed to environmental extremes, and therefore the production of bioactive metabolites was tested under both standard growth conditions for mesophilic microorganisms, and at high NaCl and sugar concentrations and low growth temperatures. The results indicate that selected halotolerant and halophilic species synthesize specific bioactive metabolites under conditions that represent stress for non-adapted species. Furthermore, adaptation at the level of the chemical nature of the solute lowering the water activity of the medium was observed. Increased salt concentrations resulted in higher hemolytic activity, particularly within species dominating the salterns. The appearance of antibacterial potential under stress conditions was seen in the similar pattern of fungal species as for hemolysis. The active extracts exclusively affected the growth of the Gram-positive bacterium tested, Bacillus subtilis. None of the extracts tested showed inhibition of acetylcholinesterase activity. PMID:21339946

  12. Activation and Products of the Cryptic Secondary Metabolite Biosynthetic Gene Clusters by Rifampin Resistance (rpoB) Mutations in Actinomycetes

    PubMed Central

    Tanaka, Yukinori; Kasahara, Ken; Hirose, Yutaka; Murakami, Kiriko; Kugimiya, Rie

    2013-01-01

    A subset of rifampin resistance (rpoB) mutations result in the overproduction of antibiotics in various actinomycetes, including Streptomyces, Saccharopolyspora, and Amycolatopsis, with H437Y and H437R rpoB mutations effective most frequently. Moreover, the rpoB mutations markedly activate (up to 70-fold at the transcriptional level) the cryptic/silent secondary metabolite biosynthetic gene clusters of these actinomycetes, which are not activated under general stressful conditions, with the exception of treatment with rare earth elements. Analysis of the metabolite profile demonstrated that the rpoB mutants produced many metabolites, which were not detected in the wild-type strains. This approach utilizing rifampin resistance mutations is characterized by its feasibility and potential scalability to high-throughput studies and would be useful to activate and to enhance the yields of metabolites for discovery and biochemical characterization. PMID:23603745

  13. Endophytic Streptomyces in the traditional medicinal plant Arnica montana L.: secondary metabolites and biological activity.

    PubMed

    Wardecki, Tina; Brötz, Elke; De Ford, Christian; von Loewenich, Friederike D; Rebets, Yuriy; Tokovenko, Bogdan; Luzhetskyy, Andriy; Merfort, Irmgard

    2015-08-01

    Arnica montana L. is a medical plant of the Asteraceae family and grows preferably on nutrient poor soils in mountainous environments. Such surroundings are known to make plants dependent on symbiosis with other organisms. Up to now only arbuscular mycorrhizal fungi were found to act as endophytic symbiosis partners for A. montana. Here we identified five Streptomyces strains, microorganisms also known to occur as endophytes in plants and to produce a huge variety of active secondary metabolites, as inhabitants of A. montana. The secondary metabolite spectrum of these strains does not contain sesquiterpene lactones, but consists of the glutarimide antibiotics cycloheximide and actiphenol as well as the diketopiperazines cyclo-prolyl-valyl, cyclo-prolyl-isoleucyl, cyclo-prolyl-leucyl and cyclo-prolyl-phenylalanyl. Notably, genome analysis of one strain was performed and indicated a huge genome size with a high number of natural products gene clusters among which genes for cycloheximide production were detected. Only weak activity against the Gram-positive bacterium Staphylococcus aureus was revealed, but the extracts showed a marked cytotoxic activity as well as an antifungal activity against Candida parapsilosis and Fusarium verticillioides. Altogether, our results provide evidence that A. montana and its endophytic Streptomyces benefit from each other by completing their protection against competitors and pathogens and by exchanging plant growth promoting signals with nutrients. PMID:26036671

  14. [The pharmacokinetics of the dipeptide analog of piracetam with nootropic activity GVS-111 and of its basic metabolites].

    PubMed

    Boĭko, S S; Zherdev, V P; Dvorianinov, A A; Gudasheva, T A; Ostrovskaia, R U; Voronina, T A; Rozantsev, G G; Seredenin, S B

    1997-01-01

    The pharmacokinetics of a new nootropic dipeptide analog of piracetam-N-phenylacetyl-L-prolylglycine (GWS-111) and its main metabolites were studied in rats by means of high performance liquid chromatography and gas-liquid chromatography. The compound under study showed a greater resistance to an enzymatic effect than natural neuropeptides. In addition to an unchanged compound three of its metabolites were found in the blood plasma of the rats. One of them, cyclo-Pro-Gly was an active metabolite of GWS-111. PMID:9206571

  15. Green Tea Catechin Metabolites Exert Immunoregulatory Effects on CD4(+) T Cell and Natural Killer Cell Activities.

    PubMed

    Kim, Yoon Hee; Won, Yeong-Seon; Yang, Xue; Kumazoe, Motofumi; Yamashita, Shuya; Hara, Aya; Takagaki, Akiko; Goto, Keiichi; Nanjo, Fumio; Tachibana, Hirofumi

    2016-05-11

    Tea catechins, such as (-)-epigallocatechin-3-O-gallate (EGCG), have been shown to effectively enhance immune activity and prevent cancer, although the underlying mechanism is unclear. Green tea catechins are instead converted to catechin metabolites in the intestine. Here, we show that these green tea catechin metabolites enhance CD4(+) T cell activity as well as natural killer (NK) cell activity. Our data suggest that the absence of a 4'-hydroxyl on this phenyl group (B ring) is important for the effect on immune activity. In particular, 5-(3',5'-dihydroxyphenyl)-γ-valerolactone (EGC-M5), a major metabolite of EGCG, not only increased the activity of CD4(+) T cells but also enhanced the cytotoxic activity of NK cells in vivo. These data suggest that EGC-M5 might show immunostimulatory activity. PMID:27112424

  16. Potent Antidiabetic Activity and Metabolite Profiling of Melicope Lunu-ankenda Leaves.

    PubMed

    Al-Zuaidy, Mizher Hezam; Hamid, Azizah Abdul; Ismail, Amin; Mohamed, Suhaila; Abdul Razis, Ahmad Faizal; Mumtaz, Muhammad Waseem; Salleh, Syafiq Zikri

    2016-05-01

    Diabetes mellitus is normally characterized by chronic hyperglycemia associated with disturbances in the fat, carbohydrate, and protein metabolism. There is an increasing trend of using natural products instead of synthetic agents as alternative therapy for disorders due to their fewer side effects. In this study, antidiabetic and antioxidant activities of different Melicope lunu-ankenda (ML) ethanolic extracts were evaluated using inhibition of α-glucosidase and 2,2-diphenyl-l-picrylhydrazyl (DPPH) radicals scavenging activity, respectively; whereas, proton nuclear magnetic resonance ((1) H NMR) and ultra-high performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) techniques were used for metabolite profiling of ML leaf extracts at different concentrations of ethanol and water. Sixty percent of ethanolic ML extract showed highest inhibitory effect against α-glucosidase enzyme (IC50 of 37 μg/mL) and DPPH scavenging activity (IC50 of 48 μg/mL). Antidiabetic effect of ML extracts was also evaluated in vivo and it was found that the high doses (400 mg/Kg BW) of ML extract exhibited high suppression in fasting blood glucose level by 62.75%. The metabolites responsible for variation among ML samples with variable ethanolic levels have been evaluated successfully using (1) H-NMR-based metabolomics. The principal component analysis (PCA) and partial least squares(PLS) analysis scores depicted clear and distinct separations into 4 clusters representing the 4 ethanolic concentrations by PC1 and PC2, with an eigenvalue of 69.9%. Various (1) H-NMR chemical shifts related to the metabolites responsible for sample difference were also ascribed. The main bioactive compounds identified attributing toward the separation included: isorhamnetin, skimmianine, scopoletin, and melicarpinone. Hence, ML may be used as promising medicinal plant for the development of new functional foods, new generation antidiabetic drugs, as a single entity phytomedicine or in

  17. Kynurenine pathway metabolites are associated with hippocampal activity during autobiographical memory recall in patients with depression.

    PubMed

    Young, Kymberly D; Drevets, Wayne C; Dantzer, Robert; Teague, T Kent; Bodurka, Jerzy; Savitz, Jonathan

    2016-08-01

    Inflammation-related changes in the concentrations of inflammatory mediators such as c-reactive protein (CRP), interleukin 1β (IL-1), and IL-6 as well as kynurenine metabolites are associated with major depressive disorder (MDD) and affect depressive behavior, cognition, and hippocampal plasticity in animal models. We previously reported that the ratios of kynurenic acid (KynA) to the neurotoxic metabolites, 3-hydroxykynurenine (3HK) and quinolinic acid (QA), were positively correlated with hippocampal volume in depression. The hippocampus is critical for autobiographical memory (AM) recall which is impaired in MDD. Here we tested whether the ratios, KynA/3HK and KynA/QA were associated with AM recall performance as well as hippocampal activity during AM recall. Thirty-five unmedicated depressed participants and 25 healthy controls (HCs) underwent fMRI scanning while recalling emotionally-valenced AMs and provided serum samples for the quantification of kynurenine metabolites, CRP, and cytokines (IL-1 receptor antagonist - IL-1RA; IL-6, tumor necrosis factor alpha - TNF, interferon gamma -IFN-γ, IL-10). KynA/3HK and KynA/QA were lower in the MDD group relative to the HCs. The concentrations of the CRP and the cytokines did not differ significantly between the HCs and the MDD group. Depressed individuals recalled fewer specific AMs and displayed increased left hippocampal activity during the recall of positive and negative memories. KynA/3HK was inversely associated with left hippocampal activity during specific AM recall in the MDD group. Further, KynA/QA was positively correlated with percent negative specific memories recalled in the MDD group and showed a non-significant trend toward a positive correlation with percent positive specific memories recalled in HCs. In contrast, neither CRP nor the cytokines were significantly associated with AM recall or activity of the hippocampus during AM recall. Conceivably, an imbalance in levels of KynA versus QA

  18. Estrogenic and androgenic activities of TBBA and TBMEPH, metabolites of novel brominated flame retardants, and selected bisphenols, using the XenoScreen XL YES/YAS assay.

    PubMed

    Fic, Anja; Žegura, Bojana; Gramec, Darja; Mašič, Lucija Peterlin

    2014-10-01

    The present study investigated and compared the estrogenic and androgenic activities of the three different classes of environmental pollutants and their metabolites using the XenoScreen XL YES/YAS assay, which has advantages compared with the original YES/YAS protocol. Contrary to the parent brominated flame retardants TBB and TBPH, which demonstrated no or very weak (anti)estrogenic or (anti)androgenic activities, their metabolites, TBBA and TBMEPH, exhibited anti-estrogenic (IC50 for TBBA=31.75 μM and IC50 for TBMEPH=0.265 μM) and anti-androgenic (IC50 for TBBA=73.95 μM and IC50 for TBMEPH=2.92 μM) activities. These results reveal that metabolism can enhance the anti-estrogenic and anti-androgenic effects of these two novel brominated flame retardants. Based on the activities of BPAF, BPF, BPA and MBP, we can conclude that the XenoScreen XL YES/YAS assay gives comparable results to the (anti)estrogenic or (anti)androgenic assays that are reported in the literature. For BPA, it was confirmed previously that the metabolite formed after an ipso-reaction (hydroxycumyl alcohol) exhibited higher estrogenic activity compared with the parent BPA, but this was not confirmed for BPAF and BPF ipso-metabolites, which were not active in the XenoScreen YES/YAS assay. Among the substituted BPA analogues, bis-GMA exhibited weak anti-estrogenic activity, BADGE demonstrated weak anti-estrogenic and anti-androgenic activities (IC50=13.73 μM), and the hydrolysed product BADGE·2H2O demonstrated no (anti)estrogenic or (anti)androgenic activities. PMID:25048928

  19. Baicalin, a metabolite of baicalein with antiviral activity against dengue virus

    PubMed Central

    Moghaddam, Ehsan; Teoh, Boon-Teong; Sam, Sing-Sin; Lani, Rafidah; Hassandarvish, Pouya; Chik, Zamri; Yueh, Andrew; Abubakar, Sazaly; Zandi, Keivan

    2014-01-01

    Baicalin, a flavonoid derived from Scutellaria baicalensis, is the main metabolite of baicalein released following administration in different animal models and human. We previously reported the antiviral activity of baicalein against dengue virus (DENV). Here, we examined the anti-DENV properties of baicalin in vitro, and described the inhibitory potentials of baicalin at different steps of DENV-2 (NGC strain) replication. Our in vitro antiviral experiments showed that baicalin inhibited virus replication at IC50 = 13.5 ± 0.08 μg/ml with SI = 21.5 following virus internalization by Vero cells. Baicalin exhibited virucidal activity against DENV-2 extracellular particles at IC50 = 8.74 ± 0.08 μg/ml and showed anti-adsorption effect with IC50 = 18.07 ± 0.2 μg/ml. Our findings showed that baicalin as the main metabolite of baicalein exerting in vitro anti-DENV activity. Further investigations on baicalein and baicalin to deduce its antiviral therapeutic effects are warranted. PMID:24965553

  20. Antifungal, Phytotoxic, and Cytotoxic Activities of Metabolites from Epichloë bromicola, a Fungus Obtained from Elymus tangutorum Grass.

    PubMed

    Song, Qiu-Yan; Nan, Zhi-Biao; Gao, Kun; Song, Hui; Tian, Pei; Zhang, Xing-Xu; Li, Chun-Jie; Xu, Wen-Bo; Li, Xiu-Zhang

    2015-10-14

    The development of high-quality herbage is an important aspect of animal husbandry. Inoculating beneficial fungi onto inferior grass is a feasible strategy for producing new varieties of high-quality herbage. Epichloë bromicola is a candidate fungus that is isolated from Elymus tangutorum. A total of 17 metabolites, 1-17, were obtained from E. bromicola, and their biological activities were assayed. Metabolite 1 exhibited antifungal activities against Alternaria alternata, Fusarium avenaceum, Bipolaris sorokiniana, and Curvularia lunata. EC50 values ranged from 0.7 to 5.3 μM, which were better than the positive control, chlorothalonil. Metabolite 8 displayed obvious phytotoxic effects toward Lolium perenne and Poa crymophila seedlings, and it was as active as glyphosate. None of these isolated metabolites displayed cytotoxicity against Madin-Darby bovine kidney cells. The IC50 values were greater than 100 μM, and the metabolites increased the growth of the cells at a concentration of 12.5 μM. The bioassay indicated that E. bromicola may be a beneficial fungus for producing new varieties of herbage with various resistances. Additionally, metabolite 7, 3-(2'-(4″-hydroxyphenyl)acetoxy)-2S-methylpropanoic acid, is a new natural product, and its stereochemistry was determined by means of optical rotation computation and chemical reactions. PMID:26395226

  1. Understanding the interactions between metabolites isolated from Achyrocline satureioides in relation to its antibacterial activity.

    PubMed

    Joray, Mariana Belén; Palacios, Sara María; Carpinella, María Cecilia

    2013-02-15

    As part of our ongoing research on the antibacterial activity of Achyrocline satureioides, this study seeks to better understand the interactions between the metabolites isolated from this plant. For this purpose, the combined effect of 23-methyl-6-O-desmethylauricepyrone (1), quercetin (2) and 3-O-methylquercetin (3), obtained through bioguided fractionation from A. satureioides ethanol extract, was evaluated against Staphylococcus aureus and Escherichia coli. In first place, the antibacterial effect of the combination of flavonols 2 and 3 was assessed, as these showed individual effectiveness lower than or equal to that of the fraction from which they were obtained. When the flavonols were applied together at concentrations below their minimum inhibitory concentration (MIC) values, a synergistic effect (FICI<0.30) against S. aureus was observed. In addition, compounds 2 and 3 in combination reduced 1000 times the MIC of compound 1, showing a clear synergistic interaction (FICI<0.15) in treatments against the Gram (+) bacterium. The most active combination against E. coli showed an additive interaction (FICI<0.62) between the three assayed compounds 1-3. These results indicated the existence of concerted action between these metabolites, evidence of the importance of the synergistic interactions between the components of plant-derived extracts for the control of pathogenic bacteria. PMID:23207251

  2. Urinary metabolites of isorhynchophylline in rats and their neuroprotective activities in the HT22 cell assay

    PubMed Central

    Chen, Fangfang; Qi, Wen; Sun, Jiahong; Simpkins, James W.; Yuan, Dan

    2015-01-01

    Isorhynchophylline is one of the major alkaloids from the Uncaria hook possessing the effects of lowered blood pressure, vasodilatation and protection against ischemia-induced neuronal damage. However, the metabolic pathway of isorhynchophylline has not been fully reported yet. In this paper, the metabolism of isorhynchophylline was investigated in rats. Five metabolites were isolated by using solvent extraction and repeated chromatographic methods, and identified by spectroscopic methods including UV, MS, NMR and CD experiments. Three new compounds were identified as 5-oxoisorhynchophyllic acid-22-O-β-D-glucuronide (M1), 17-O-demethyl-16,17-dihydro isorhynchophylline (M2) and 5-oxoisorhynchophyllic acid (M4) together with two known compounds isorhynchophylline (M0) and rhynchophylline (M3). Possible metabolic pathways of isorhynchophylline are proposed. Furthermore, the activity assay for all the metabolites showed that isorhynchophylline (M0) exhibited potent neuroprotective effects against glutamate-induced HT22 cell death. However, little or weak neuroprotective activities were observed for M1–M4. Our present study is important to further understand its metabolic fate and disposition in humans. PMID:24910000

  3. In vitro metabolism of pyripyropene A and ACAT inhibitory activity of its metabolites.

    PubMed

    Matsuda, Daisuke; Ohshiro, Taichi; Ohtawa, Masaki; Yamazaki, Hiroyuki; Nagamitsu, Tohru; Tomoda, Hiroshi

    2015-01-01

    Pyripyropene A (PPPA, 1) of fungal origin, a selective inhibitor of acyl-CoA:cholesterol acyltransferase 2 (ACAT2), proved orally active in atherogenic mouse models. The in vitro metabolites of 1 in liver microsomes and plasma of human, rabbit, rat and mouse were analyzed by ultra fast liquid chromatography and liquid chromatography/tandem mass spectrometry. In the liver microsomes from all species, successive hydrolysis occurred at the 1-O-acetyl residue, then at the 11-O-acetyl residue of 1, while the 7-O-acetyl residue was resistant to hydrolysis. Furthermore, dehydrogenation of the newly generated 11-alcoholic hydroxyl residue occurred in human and mouse-liver microsomes, while oxidation of the pyridine ring occurred in human and rabbit liver microsomes. On the other hand, hydrolysis of the 7-O-acetyl residue proceeded only in the mouse plasma. These data indicated that the in vitro metabolic profiles of 1 have subtle differences among animal species. All of the PPPA metabolites observed in liver microsomes and plasma markedly decreased ACAT2 inhibitory activity. These findings will help us to synthesize new PPPA derivatives more effective in in vivo study than 1. PMID:25005817

  4. Urinary metabolites of isorhynchophylline in rats and their neuroprotective activities in the HT22 cell assay.

    PubMed

    Chen, Fangfang; Qi, Wen; Sun, Jiahong; Simpkins, James W; Yuan, Dan

    2014-09-01

    Isorhynchophylline is one of the major alkaloids from the Uncaria hook possessing the effects of lowered blood pressure, vasodilatation and protection against ischemia-induced neuronal damage. However, the metabolic pathway of isorhynchophylline has not been fully reported yet. In this paper, the metabolism of isorhynchophylline was investigated in rats. Five metabolites were isolated by using solvent extraction and repeated chromatographic methods, and identified by spectroscopic methods including UV, MS, NMR and CD experiments. Three new compounds were identified as 5-oxoisorhynchophyllic acid-22-O-β-D-glucuronide (M1), 17-O-demethyl-16,17-dihydro isorhynchophylline (M2) and 5-oxoisorhynchophyllic acid (M4) together with two known compounds isorhynchophylline (M0) and rhynchophylline (M3). Possible metabolic pathways of isorhynchophylline are proposed. Furthermore, the activity assay for all the metabolites showed that isorhynchophylline (M0) exhibited potent neuroprotective effects against glutamate-induced HT22 cell death. However, little or weak neuroprotective activities were observed for M1-M4. Our present study is important to further understand its metabolic fate and disposition in humans. PMID:24910000

  5. The vitamin D3 metabolite-type activity of Solanum malacoxylon.

    PubMed

    Basudde, C D; Humphreys, D J

    1976-01-01

    1. Administration of an aqueous extract of the dried leaves of Solanum malacoxylon (DLSM) to rats causes a rapid hyperphosphataemia and a decrease in plasma alkaline phosphatase activity; the two effects are typical of 1,25(OH)2D3, the hormonally active metabolite of vitamin D3. 2. DLSM, like both vitamin D3 and parathyroid hormone, increases plasma calcium and citrate levels in rats. The effect of DLSM in influencing plasma citrate, and the role of this important metabolite in mineral metabolism is discussed. 3. A decrease of plasma magnesium levels occurs in rats following treatment with DLSM. This decrease, which is associated with a renal loss of this cation, is remarkably similar to that produced by hypervitaminosis D3. 4. Prolonged administration of DLSM to vitamin D deficient rats causes a polyuria, hypercalciuria, hyperphosphaturia, hypermagnesuria, an increase in urinary total hydroxyproline, an increase in plasma total hexosamines, and a corresponding decrease in the bone total hexosamines. These effects, some of which can also be produced by hyperparathyroidism, or following the administration of parathyroid extract (PTE), large doses of vitamin D3, or 1,25(OH)2D3, suggest that DLSM, like the latter compounds, is capable of causing bone mineral mobilization, and the dissolution of bone organic matrix. PMID:212224

  6. Cytochrome P450-dependent eicosapentaenoic acid metabolites are novel BK channel activators.

    PubMed

    Lauterbach, Birgit; Barbosa-Sicard, Eduardo; Wang, Mong-Heng; Honeck, Horst; Kärgel, Eva; Theuer, Jürgen; Schwartzman, Michal L; Haller, Hermann; Luft, Friedrich C; Gollasch, Maik; Schunck, Wolf-Hagen

    2002-02-01

    P450-dependent arachidonic acid (AA) metabolites regulate arterial tone by modulating calcium-activated (BK) potassium channels in vascular smooth muscle cells (VSMC). Because eicosapentaenoic acid (EPA) has been reported to improve vascular function, we tested the hypothesis that P450-dependent epoxygenation of EPA produces alternative vasoactive compounds. We synthesized the 5 regioisomeric epoxyeicosattrienoic acids (EETeTr) and examined them for effects on K(+) currents in rat cerebral artery VSMCs with the patch-clamp technique. 11(R),12(S)-epoxyeicosatrienoic acid (50 nmol/L) was used for comparison and stimulated K(+) currents 6-fold at +60 mV. However, 17(R),18(S)-EETeTr elicited a more than 14-fold increase. 17(S),18(R)-EET and the remaining four regioisomers were inactive. The effect of 17(R),18(S)-EETeTr was blocked by tetraethylammonium but not by 4-aminopyridine. VSMCs expressed P450s 4A1 and 4A3. Recombinant P450 4A1 hydroxylated EPA at C-19 and C-20 and epoxygenated the 17,18-double bond, yielding the R, S- and S, R-enantiomers in a ratio of 64:36. We conclude that 17(R),18(S)-EETeTr represents a novel, potent activator of BK potassium channels. Furthermore, this metabolite can be directly produced in VSMCs. We suggest that 17(R),18(S)-EETeTr may function as an important hyperpolarizing factor, particularly with EPA-rich diets. PMID:11882617

  7. Antimicrobial and Cytotoxic Activity of Extracts of Ferula heuffelii Griseb. ex Heuff. and Its Metabolites.

    PubMed

    Pavlović, Ivan; Petrović, Silvana; Milenković, Marina; Stanojković, Tatjana; Nikolić, Dejan; Krunić, Aleksej; Niketić, Marjan

    2015-10-01

    The antimicrobial and cytotoxic activities of isolates (CHCl3 and MeOH extracts and selected metabolites) obtained from the underground parts of the Balkan endemic plant Ferula heuffelii Griseb. ex Heuff. were assessed. The CHCl3 and MeOH extracts exhibited moderate antimicrobial activity, being more pronounced against Gram-positive than Gram-negative bacteria, especially against Staphylococcus aureus (MIC=12.5 μg/ml for both extracts) and Micrococcus luteus (MIC=50 and 12.5 μg/ml, resp.). Among the tested metabolites, (6E)-1-(2,4-dihydroxyphenyl)-3,7,11-trimethyl-3-vinyldodeca-6,10-dien-1-one (2) and (2S*,3R*)-2-[(3E)-4,8-dimethylnona-3,7-dien-1-yl]-2,3-dihydro-7-hydroxy-2,3-dimethylfuro[3,2-c]coumarin (4) demonstrated the best antimicrobial activity. Compounds 2 and 4 both strongly inhibited the growth of M. luteus (MIC=11.2 and 5.2 μM, resp.) and Staphylococcus epidermidis (MIC=22.5 and 10.5 μM, resp.) and compound 2 additionally also the growth of Bacillus subtilis (MIC=11.2 μM). The cytotoxic activity of the isolates was tested against three human cancer cell lines, viz., cervical adenocarcinoma (HeLa), chronic myelogenous leukemia (K562), and breast cancer (MCF-7) cells. The CHCl3 extract exhibited strong cytotoxic activity against all cell lines (IC50 <11.0 μg/ml). All compounds strongly inhibited the growth of the K562 and HeLa cell lines. Compound 4 exhibited also a strong activity against the MCF-7 cell line, comparable to that of cisplatin (IC50 =22.32±1.32 vs. 18.67±0.75μM). PMID:26460563

  8. Metabolic activation of tris(2,3-dibromopropyl)phosphate to reactive intermediates. II. Covalent binding, reactive metabolite formation, and differential metabolite-specific DNA damage in vivo.

    PubMed

    Pearson, P G; Omichinski, J G; Holme, J A; McClanahan, R H; Brunborg, G; Søderlund, E J; Dybing, E; Nelson, S D

    1993-02-01

    Analogs of tris(2,3-dibromopropyl)phosphate (Tris-BP) either labeled at specific positions with carbon-14 and phosphorus-32 or dual-labeled with both deuterium and tritium were administered to male Wistar rats at a nephrotoxic dose of 360 mumol/kg. The covalent binding of Tris-BP metabolites to hepatic, renal, and testicular proteins was determined after 9 and 24 hr, and plasma concentrations of bis(2,3-dibromopropyl)-phosphate (Bis-BP) formed metabolically from Tris-BP were measured at intervals throughout the initial 9-hr postdosing period. The covalent binding of 14C-Tris-BP metabolites in the kidney (2495 +/- 404 pmol/mg protein) was greater than that in the liver (476 +/- 123 pmol/mg protein) or testes (94 +/- 11 pmol/mg protein); the extent of renal covalent protein binding of Tris-BP metabolites was decreased by 82 and 84% when deuterium was substituted at carbon-2 and carbon-3, respectively. Substitution of Tris-BP with deuterium at carbon-2 or carbon-3 also decreased the mean area under the curve for Bis-BP plasma concentration by 48 and 57%, respectively. The mechanism of Tris-BP-induced renal and hepatic DNA damage was evaluated in Wistar rats by an automated alkaline elution procedure after the administration of analogs of Tris-BP or Bis-BP labeled at specific positions with deuterium. Renal DNA damage was decreased when Tris-BP was substituted with deuterium at either carbon-2 or carbon-3; the magnitude of the change correlated with both a decrease in the area under the Bis-BP plasma curve and a decrease in renal covalent binding of Tris-BP metabolites for each of the deuterated analogs. In marked contrast, analogs of Bis-BP labeled with deuterium at carbon-2 or carbon-3 did not show a decrease in the severity of renal DNA damage compared to unlabeled Bis-BP. On the basis of these observations a metabolic scheme for hepatic P-450-mediated oxidation at either carbon-2 or carbon-3 of Tris-BP affording Bis-BP by two alternate pathways that are susceptible

  9. Citrus fruits as a treasure trove of active natural metabolites that potentially provide benefits for human health.

    PubMed

    Lv, Xinmiao; Zhao, Siyu; Ning, Zhangchi; Zeng, Honglian; Shu, Yisong; Tao, Ou; Xiao, Cheng; Lu, Cheng; Liu, Yuanyan

    2015-01-01

    Citrus fruits, which are cultivated worldwide, have been recognized as some of the most high-consumption fruits in terms of energy, nutrients and health supplements. What is more, a number of these fruits have been used as traditional medicinal herbs to cure diseases in several Asian countries. Numerous studies have focused on Citrus secondary metabolites as well as bioactivities and have been intended to develop new chemotherapeutic or complementary medicine in recent decades. Citrus-derived secondary metabolites, including flavonoids, alkaloids, limonoids, coumarins, carotenoids, phenolic acids and essential oils, are of vital importance to human health due to their active properties. These characteristics include anti-oxidative, anti-inflammatory, anti-cancer, as well as cardiovascular protective effects, neuroprotective effects, etc. This review summarizes the global distribution and taxonomy, numerous secondary metabolites and bioactivities of Citrus fruits to provide a reference for further study. Flavonoids as characteristic bioactive metabolites in Citrus fruits are mainly introduced. PMID:26705419

  10. Antimicrobial and antiprotozoal activities of secondary metabolites from the fungus Eurotium repens

    PubMed Central

    Gao, Jiangtao; Radwan, Mohamed M.; León, Francisco; Wang, Xiaoning; Jacob, Melissa R.; Tekwani, Babu L.; Khan, Shabana I.; Lupien, Shari; Hill, Robert A.; Dugan, Frank M.; Cutler, Horace G.

    2011-01-01

    In this study, we examined in vitro antibacterial, antifungal, antimalarial, and antileishmanial activities of secondary metabolites (1–8) isolated from the fungus Eurotium repens. All compounds showed mild to moderate antibacterial or antifungal or both activities except 7. The activity of compound 6 was the best of the group tested. The in vitro antimalarial evaluation of these compounds revealed that compounds 1–3, 5, and 6 showed antimalarial activities against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum with IC50 values in the range of 1.1–3.0 μg/ml without showing any cytotoxicity to the mammalian cells. Compound 5 displayed the highest antimalarial activity. Antileishmanial activity against Leishmania donovani promastigotes was observed for compounds 1–6 with IC50 values ranging from 6.2 to 23 μg/ml. Antileishmanial activity of compounds 5 and 6 (IC50 values of 7.5 and 6.2 μg/ml, respectively) was more potent than 1–4 (IC50 values ranging from 19–23 μg/ml). Compounds 7 and 8 did not show any antiprotozoal effect. Preliminary structure and activity relationship studies indicated that antibacterial, antifungal, antimalarial, and antileishmanial activities associated with phenol derivates (1–6) seem to be dependent on the number of double bonds in the side chain, which would be important for lead optimization in the future. PMID:23024574

  11. Oxidative DNA damage by an N-hydroxy metabolite of the mutagenic compound formed from norharman and aniline.

    PubMed

    Ohnishi, S; Murata, M; Oikawa, S; Totsuka, Y; Takamura, T; Wakabayashi, K; Kawanishi, S

    2001-07-25

    Norharman (9H-pyrido[3,4-b]indole), which is a heterocyclic amine included in cigarette smoke or cooked foodstuffs, is not mutagenic itself. However, norharman reacts with non-mutagenic aniline to form mutagenic aminophenylnorharman (APNH), of which DNA adducts formation and hepatocarcinogenic potential are pointed out. We investigated whether N-OH-APNH, an N-hydroxy metabolite of APNH, can cause oxidative DNA damage or not, using 32P-labeled DNA fragments. N-OH-APNH caused Cu(II)-mediated DNA damage. When an endogenous reductant, beta-nicotinamide adenine dinucleotide (NADH) was added, the DNA damage was greatly enhanced. Catalase and a Cu(I)-specific chelator inhibited DNA damage, suggesting the involvement of H(2)O(2) and Cu(I). Typical -*OH scavenger did not inhibit DNA damage. These results suggest that the main reactive species are probably copper-hydroperoxo complexes with DNA. We also measured 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation by N-OH-APNH in the presence of Cu(II), using an electrochemical detector coupled to a high-pressure liquid chromatograph. Addition of NADH greatly enhanced 8-oxodG formation. UV-VIS spectra and mass spectra suggested that N-OH-APNH was autoxidized to nitrosophenylnorharman (NO-PNH). We speculated that NO-PNH was reduced by NADH. Cu(II) facilitated the redox cycle. In the presence of NADH and Cu(II), very low concentrations of N-OH-APNH could induce DNA damage via redox reactions. We conclude that oxidative DNA damage, in addition to DNA adduct formation, may play an important role in the expression of genotoxicity of APNH. PMID:11423346

  12. Mutagenic activity and metabolites in the urine of workers exposed to trinitrotoluene (TNT).

    PubMed

    Ahlborg, G; Einistö, P; Sorsa, M

    1988-05-01

    Urine samples taken after work and after a free weekend from 50 workers employed in various activities in a chemical plant manufacturing explosives were analysed. On the basis of hygienic surveys, the subjects were divided into three categories of exposure to trinitrotoluene (TNT). The urine analyses consisted of gas chromatographic identification of TNT and its two metabolites, 4-ADNT and 2-ADNT, and a determination of the mutagenic activity. Two frame shift detector strains of Salmonella typhimurium were used, TA 98 and TA 98 NR, the latter being deficient in endogenous nitroreductase activity. On the basis of previous results on TNT mutagenicity, no exogeneous metabolic system was used to test the urine concentrates. Both tester strains showed that the mean urinary mutagenic activity was higher in the after work samples than in post weekend samples from the same subjects, showing that bacterial nitroreductase activity was not significantly responsible for the mutagenicity, although the response was higher with strain TA 98 than with TA 98 NR. The interindividual variation in urine mutagenicity was high, however, and the difference between the two sampling times was statistically significant (p less than 0.05) only for the high exposed group (workers in trotyl foundry and sieve house). Correlation between urinary mutagenicity and concentration of TNT in urine was poor; correlation was significant only with the urinary concentration of 4-ADNT. The correlation between urinary TNT and both metabolites was good (p less than 0.001). These results suggest that analysis of 4-ADNT in urine would be a sufficient biological measure for controlling exposure to TNT. PMID:3378017

  13. Biotransformation of Bisphenol AF to Its Major Glucuronide Metabolite Reduces Estrogenic Activity

    PubMed Central

    Yin, Jie; Zhang, Jing; Feng, Yixing; Shao, Bing

    2013-01-01

    Bisphenol AF (BPAF), an endocrine disrupting chemical, can induce estrogenic activity through binding to estrogen receptor (ER). However, the metabolism of BPAF in vivo and the estrogenic activity of its metabolites remain unknown. In the present study, we identified four metabolites including BPAF diglucuronide, BPAF glucuronide (BPAF-G), BPAF glucuronide dehydrated and BPAF sulfate in the urine of Sprague-Dawley (SD) rats. BPAF-G was further characterized by nuclear magnetic resonance (NMR). After treatment with a single dose of BPAF, BPAF was metabolized rapidly to BPAF-G, as detected in the plasma of SD rats. Biotransformation of BPAF to BPAF-G was confirmed with human liver microsomes (HLM), and Vmax of glucuronidation for HLM was 11.6 nmol/min/mg. We also found that BPAF glucuronidation could be mediated through several human recombinant UDP-glucuronosyltransferases (UGTs) including UGT1A1, UGT1A3, UGT1A8, UGT1A9, UGT2B4, UGT2B7, UGT2B15 and UGT2B17, among which UGT2B7 showed the highest efficiency of glucuronidation. To explain the biological function of BPAF biotransformation, the estrogenic activities of BPAF and BPAF-G were evaluated in ER-positive breast cancer T47D and MCF7 cells. BPAF significantly stimulates ER-regulated gene expression and cell proliferation at the dose of 100 nM and 1 μM in breast cancer cells. However, BPAF-G did not show any induction of estrogenic activity at the same dosages, implying that formation of BPAF-G is a potential host defense mechanism against BPAF. Based on our study, biotransformation of BPAF to BPAF-G can eliminate BPAF-induced estrogenic activity, which is therefore considered as reducing the potential threat to human beings. PMID:24349450

  14. Biotransformation of bisphenol AF to its major glucuronide metabolite reduces estrogenic activity.

    PubMed

    Li, Ming; Yang, Yunjia; Yang, Yi; Yin, Jie; Zhang, Jing; Feng, Yixing; Shao, Bing

    2013-01-01

    Bisphenol AF (BPAF), an endocrine disrupting chemical, can induce estrogenic activity through binding to estrogen receptor (ER). However, the metabolism of BPAF in vivo and the estrogenic activity of its metabolites remain unknown. In the present study, we identified four metabolites including BPAF diglucuronide, BPAF glucuronide (BPAF-G), BPAF glucuronide dehydrated and BPAF sulfate in the urine of Sprague-Dawley (SD) rats. BPAF-G was further characterized by nuclear magnetic resonance (NMR). After treatment with a single dose of BPAF, BPAF was metabolized rapidly to BPAF-G, as detected in the plasma of SD rats. Biotransformation of BPAF to BPAF-G was confirmed with human liver microsomes (HLM), and Vmax of glucuronidation for HLM was 11.6 nmol/min/mg. We also found that BPAF glucuronidation could be mediated through several human recombinant UDP-glucuronosyltransferases (UGTs) including UGT1A1, UGT1A3, UGT1A8, UGT1A9, UGT2B4, UGT2B7, UGT2B15 and UGT2B17, among which UGT2B7 showed the highest efficiency of glucuronidation. To explain the biological function of BPAF biotransformation, the estrogenic activities of BPAF and BPAF-G were evaluated in ER-positive breast cancer T47D and MCF7 cells. BPAF significantly stimulates ER-regulated gene expression and cell proliferation at the dose of 100 nM and 1 μM in breast cancer cells. However, BPAF-G did not show any induction of estrogenic activity at the same dosages, implying that formation of BPAF-G is a potential host defense mechanism against BPAF. Based on our study, biotransformation of BPAF to BPAF-G can eliminate BPAF-induced estrogenic activity, which is therefore considered as reducing the potential threat to human beings. PMID:24349450

  15. Isophosphoramide mustard, a metabolite of ifosfamide with activity against murine tumours comparable to cyclophosphamide.

    PubMed Central

    Struck, R. F.; Dykes, D. J.; Corbett, T. H.; Suling, W. J.; Trader, M. W.

    1983-01-01

    Isophosphoramide mustard was synthesized and was found to demonstrate activity essentially comparable to cyclophosphamide and ifosfamide against L1210 and P388 leukaemia. Lewis lung carcinoma, mammary adenocarcinoma 16/C, ovarian sarcoma M5076, and colon tumour 6A, in mice and Yoshida ascitic sarcoma in rats. At doses less than, or equivalent to, the LD10, isophosphoramide mustard retained high activity against cyclophosphamide-resistant L1210 and P388 leukaemias, but was less active against intracerebrally-implanted P388 leukaemia while cyclophosphamide produced a 4 log10 tumour cell reduction. It was also less active (one log10 lower cell kill) than cyclophosphamide against the B16 melonoma. Metabolism studies on ifosfamide in mice identified isophosphoramide mustard in blood. In addition, unchanged drug, carboxyifosfamide, 4-ketoifosfamide, dechloroethyl cyclophosphamide, dechloroethylifosfamide, and alcoifosfamide were identified. The latter 4 metabolites were also identified in urine from an ifosfamide-treated dog. In a simulated in vitro pharmacokinetic experiment against L1210 leukaemia in which drugs were incubated at various concentrations for various times, both 4-hydroxycyclophosphamide and isophosphoramide mustard exhibited significant cytoxicity at concentration times time values of 100-1000 micrograms X min ml-1, while acrolein was significantly cytotoxic at 10 micrograms X min ml-1. Treatment of mice with drug followed by L1210 cells demonstrated a shorter duration of effective levels of cytotoxic activity for isophosphoramide mustard and phosphoramide mustard in comparison with cyclophosphamide and ifosfamide. Isophosphoramide mustard and 2-chloroethylamine, a potential hydrolysis product of isophosphoramide mustard and carboxyifosfamide, were less mutagenic in the standard Ames test than the 2 corresponding metabolites of cyclophosphamide [phosphoramide mustard and bis(2-chloroethyl)amine]. PMID:6821629

  16. Plasma cathepsin D isoforms and their active metabolites increase after myocardial infarction and contribute to plasma renin activity.

    PubMed

    Naseem, R Haris; Hedegard, Wade; Henry, Timothy D; Lessard, Jennifer; Sutter, Kathryn; Katz, Stephen A

    2005-03-01

    Plasma renin activity (PRA) is often found to increase after myocardial infarction (MI). Elevated PRA may contribute to increased myocardial angiotensin II that is responsible for maladaptive remodeling of the myocardium after MI. We hypothesized that MI would also result in cardiac release of cathepsin D, a ubiquitous lysosomal enzyme with high renin sequence homology. Cathepsin D release from damaged myocardial tissue could contribute to angiotensin formation by acting as an enzymatic alternate to renin. We assessed circulating renin and cathepsin D from both control and MI patient plasma (7-20 hours after MI) using shallow gradient focusing that allowed for independent measurement of both enzymes. Cathepsin D was increased significantly in the plasma after MI (P < 0.001). Furthermore, circulating active cathepsin D metabolites were also significantly elevated after MI (P < 0.04), and contained the majority of cathepsin D activity in plasma. Spiking control plasma with cathepsin D resulted in a variable but significant (P = 0.005) increase in PRA using a clinical assay. We conclude that 7-20 hours after MI, plasma cathepsin D is significantly elevated and most of the active enzymatic activity is circulating as plasma metabolites. Circulating cathepsin D can falsely increase clinical PRA determinations, and may also provide an alternative angiotensin formation pathway after MI. PMID:15739123

  17. Symphonia globulifera, a widespread source of complex metabolites with potent biological activities.

    PubMed

    Fromentin, Yann; Cottet, Kevin; Kritsanida, Marina; Michel, Sylvie; Gaboriaud-Kolar, Nicolas; Lallemand, Marie-Christine

    2015-01-01

    Symphonia globulifera has been widely used in traditional medicine and has therefore been subjected to several phytochemical studies in the American and African continents. Interestingly, some disparities have been observed concerning its metabolic profile. Several phytochemical studies of S. globulifera have led to the identification of more than 40 compounds, including several polycyclic polyprenylated acylphloroglucinols. Biological evaluations have pointed out the promising biological activities of these secondary metabolites, mostly as antiparasitic or antimicrobial, confirming the traditional use of this plant. The purpose of this review is to describe the natural occurrence, botanical aspects, ethnomedicinal use, structure, and biogenesis, as well as biological activities of compounds isolated from this species according to their provenance. PMID:25590372

  18. Bioactive Metabolites from Chaetomium aureum: Structure Elucidation and Inhibition of the Hsp90 Machine Chaperoning Activity

    PubMed Central

    Kabbaj, Fatima Zahra; Lu, Su; Faouzi, My El Abbés; Meddah, Bouchra; Proksch, Peter; Cherrah, Yahya; Altenbach, Hans-Josef; Aly, Amal H.; Chadli, Ahmed; Debbab, Abdessamad

    2014-01-01

    Chemical investigation of the EtOAc extract of the fungus Chaetomium aureum, an endophyte of the Moroccan medicinal plant Thymelaea lythroides, afforded one new resorcinol derivative named chaetorcinol, together with five known metabolites. The structures of the isolated compounds were determined on the basis of one- and two-dimensional NMR spectroscopy and high-resolution mass spectrometry as well as by comparison with the literature. All compounds were tested for their activity towards the Hsp90 chaperoning machine in vitro using the progesterone receptor (PR) and rabbit reticulocyte lysate (RRL). Among the isolated compounds, only sclerotiorin efficiently inhibited the Hsp90 machine chaperoning activity. However, sclerotiorin showed no cytotoxic effect on breast cancer Hs578T, MDA-MB-231 and prostate cancer LNCaP cell lines. Interestingly, deacetylation of sclerotiorin increased its cytotoxicity toward the tested cell lines over a period of 48h. PMID:25482429

  19. Prototype Systems Containing Human Cytochrome P450 for High-Throughput Real-Time Detection of DNA Damage by Compounds That Form DNA-Reactive Metabolites.

    PubMed

    Brito Palma, Bernardo; Fisher, Charles W; Rueff, José; Kranendonk, Michel

    2016-05-16

    The formation of reactive metabolites through biotransformation is the suspected cause of many adverse drug reactions. Testing for the propensity of a drug to form reactive metabolites has increasingly become an integral part of lead-optimization strategy in drug discovery. DNA reactivity is one undesirable facet of a drug or its metabolites and can lead to increased risk of cancer and reproductive toxicity. Many drugs are metabolized by cytochromes P450 in the liver and other tissues, and these reactions can generate hard electrophiles. These hard electrophilic reactive metabolites may react with DNA and may be detected in standard in vitro genotoxicity assays; however, the majority of these assays fall short due to the use of animal-derived organ extracts that inadequately represent human metabolism. The current study describes the development of bacterial systems that efficiently detect DNA-damaging electrophilic reactive metabolites generated by human P450 biotransformation. These assays use a GFP reporter system that detects DNA damage through induction of the SOS response and a GFP reporter to control for cytotoxicity. Two human CYP1A2-competent prototypes presented here have appropriate characteristics for the detection of DNA-damaging reactive metabolites in a high-throughput manner. The advantages of this approach include a short assay time (120-180 min) with real-time measurement, sensitivity to small amounts of compound, and adaptability to a microplate format. These systems are suitable for high-throughput assays and can serve as prototypes for the development of future enhanced versions. PMID:27031942

  20. In-stream attenuation of neuro-active pharmaceuticals and their metabolites

    USGS Publications Warehouse

    Writer, Jeffrey; Antweiler, Ronald C.; Ferrar, Imma; Ryan, Joseph N.; Thurman, Michael

    2013-01-01

    In-stream attenuation was determined for 14 neuro-active pharmaceuticals and associated metabolites. Lagrangian sampling, which follows a parcel of water as it moves downstream, was used to link hydrological and chemical transformation processes. Wastewater loading of neuro-active compounds varied considerably over a span of several hours, and thus a sampling regime was used to verify that the Lagrangian parcel was being sampled and a mechanism was developed to correct measured concentrations if it was not. In-stream attenuation over the 5.4-km evaluated reach could be modeled as pseudo-first-order decay for 11 of the 14 evaluated neuro-active pharmaceutical compounds, illustrating the capacity of streams to reduce conveyance of neuro-active compounds downstream. Fluoxetine and N-desmethyl citalopram were the most rapidly attenuated compounds (t1/2 = 3.6 ± 0.3 h, 4.0 ± 0.2 h, respectively). Lamotrigine, 10,11,-dihydro-10,11,-dihydroxy-carbamazepine, and carbamazepine were the most persistent (t1/2 = 12 ± 2.0 h, 12 ± 2.6 h, 21 ± 4.5 h, respectively). Parent compounds (e.g., buproprion, carbamazepine, lamotrigine) generally were more persistent relative to their metabolites. Several compounds (citalopram, venlafaxine, O-desmethyl-venlafaxine) were not attenuated. It was postulated that the primary mechanism of removal for these compounds was interaction with bed sediments and stream biofilms, based on measured concentrations in stream biofilms and a column experiment using stream sediments.

  1. In-stream attenuation of neuro-active pharmaceuticals and their metabolites.

    PubMed

    Writer, Jeffrey H; Antweiler, Ronald C; Ferrer, Imma; Ryan, Joseph N; Thurman, E Michael

    2013-09-01

    In-stream attenuation was determined for 14 neuro-active pharmaceuticals and associated metabolites. Lagrangian sampling, which follows a parcel of water as it moves downstream, was used to link hydrological and chemical transformation processes. Wastewater loading of neuro-active compounds varied considerably over a span of several hours, and thus a sampling regime was used to verify that the Lagrangian parcel was being sampled and a mechanism was developed to correct measured concentrations if it was not. In-stream attenuation over the 5.4-km evaluated reach could be modeled as pseudo-first-order decay for 11 of the 14 evaluated neuro-active pharmaceutical compounds, illustrating the capacity of streams to reduce conveyance of neuro-active compounds downstream. Fluoxetine and N-desmethyl citalopram were the most rapidly attenuated compounds (t1/2 = 3.6 ± 0.3 h, 4.0 ± 0.2 h, respectively). Lamotrigine, 10,11,-dihydro-10,11,-dihydroxy-carbamazepine, and carbamazepine were the most persistent (t1/2 = 12 ± 2.0 h, 12 ± 2.6 h, 21 ± 4.5 h, respectively). Parent compounds (e.g., buproprion, carbamazepine, lamotrigine) generally were more persistent relative to their metabolites. Several compounds (citalopram, venlafaxine, O-desmethyl-venlafaxine) were not attenuated. It was postulated that the primary mechanism of removal for these compounds was interaction with bed sediments and stream biofilms, based on measured concentrations in stream biofilms and a column experiment using stream sediments. PMID:23952127

  2. Continuing hunt for endophytic actinomycetes as a source of novel biologically active metabolites.

    PubMed

    Masand, Meeta; Jose, Polpass Arul; Menghani, Ekta; Jebakumar, Solomon Robinson David

    2015-12-01

    Drug-resistant pathogens and persistent agrochemicals mount the detrimental threats against human health and welfare. Exploitation of beneficial microorganisms and their metabolic inventions is most promising way to tackle these two problems. Since the successive discoveries of penicillin and streptomycin in 1940s, numerous biologically active metabolites have been discovered from different microorganisms, especially actinomycetes. In recent years, actinomycetes that inhabit unexplored environments have received significant attention due to their broad diversity and distinctive metabolic potential with medical, agricultural and industrial importance. In this scenario, endophytic actinomycetes that inhabit living tissues of plants are emerging as a potential source of novel bioactive compounds for the discovery of drug leads. Also, endophytic actinomycetes are considered as bio-inoculants to improve crop performance through organic farming practices. Further efforts on exploring the endophytic actinomycetes associated with the plants warrant the likelihood of discovering new taxa and their metabolites with novel chemical structures and biotechnological importance. This mini-review highlights the recent achievements in isolation of endophytic actinomycetes and an assortment of bioactive compounds. PMID:26410426

  3. Atrazine and its main metabolites alter the locomotor activity of larval zebrafish (Danio rerio).

    PubMed

    Liu, Zhenzhen; Wang, Yueyi; Zhu, Zhihong; Yang, Enlu; Feng, Xiayan; Fu, Zhengwei; Jin, Yuanxiang

    2016-04-01

    Atrazine (ATZ) and its main chlorometabolites, i.e., diaminochlorotriazine (DACT), deisopropylatrazine (DIP), and deethylatrazine (DE), have been widely detected in aquatic systems near agricultural fields. However, their possible effects on aquatic animals are still not fully understood. In this study, it was observed that several developmental endpoints such as the heart beat, hatchability, and morphological abnormalities were influenced by ATZ and its metabolites in different developmental stages. In addition, after 5 days of exposure to 30, 100, 300 μg L(-1) ATZ and its main chlorometabolites, the swimming behaviors of larval zebrafish were significantly disturbed, and the acetylcholinesterase (AChE) activities were consistently inhibited. Our results also demonstrate that ATZ and its main chlorometabolites are neuroendocrine disruptors that impact the expression of neurotoxicity-related genes such as Ache, Gap43, Gfap, Syn2a, Shha, Mbp, Elavl3, Nestin and Ngn1 in early developmental stages of zebrafish. According to our results, it is possible that not only ATZ but also its metabolites (DACT, DIP and DE) have the same or even more toxic effects on different endpoints of the early developmental stages of zebrafish. PMID:26803580

  4. Current results on biological activities of lichen secondary metabolites: a review.

    PubMed

    Molnár, Katalin; Farkas, Edit

    2010-01-01

    Lichens are symbiotic organisms of fungi and algae or cyanobacteria. Lichen-forming fungi synthesize a great variety of secondary metabolites, many of which are unique. Developments in analytical techniques and experimental methods have resulted in the identification of about 1050 lichen substances (including those found in cultures). In addition to their role in lichen chemotaxonomy and systematics, lichen secondary compounds have several possible biological roles, including photoprotection against intense radiation, as well as allelochemical, antiviral, antitumor, antibacterial, antiherbivore, and antioxidant action. These compounds are also important factors in metal homeostasis and pollution tolerance of lichen thalli. Although our knowledge of the contribution of these extracellular products to the success of the lichen symbiosis has increased significantly in the last decades, their biotic and abiotic roles have not been entirely explored. PMID:20469633

  5. Anthocyanins and their gut metabolites reduce the adhesion of monocyte to TNFα-activated endothelial cells at physiologically relevant concentrations.

    PubMed

    Krga, Irena; Monfoulet, Laurent-Emmanuel; Konic-Ristic, Aleksandra; Mercier, Sylvie; Glibetic, Maria; Morand, Christine; Milenkovic, Dragan

    2016-06-01

    An increasing number of evidence suggests a protective role of dietary anthocyanins against cardiovascular diseases. Anthocyanins' extensive metabolism indicates that their metabolites could be responsible for the protective effects associated with consumption of anthocyanin-rich foods. The aim of this work was to investigate the effect of plasma anthocyanins and their metabolites on the adhesion of monocytes to TNFα-activated endothelial cells and on the expression of genes encoding cell adhesion molecules. Human umbilical vein endothelial cells (HUVECs) were exposed to circulating anthocyanins: cyanidin-3-arabinoside, cyanidin-3-galactoside, cyanidin-3-glucoside, delphinidin-3-glucoside, peonidin-3-glucoside, anthocyanin degradation product: 4-hydroxybenzaldehyde, or to their gut metabolites: protocatechuic, vanillic, ferulic and hippuric acid, at physiologically-relevant concentrations (0.1-2 μM) and time of exposure. Both anthocyanins and gut metabolites decreased the adhesion of monocytes to HUVECs, with a magnitude ranging from 18.1% to 47%. The mixture of anthocyanins and that of gut metabolites also reduced monocyte adhesion. However, no significant effect on the expression of genes encoding E-selectin, ICAM1 and VCAM1 was observed, suggesting that other molecular targets are involved in the observed effect. In conclusion, this study showed the potency of anthocyanins and their gut metabolites to modulate the adhesion of monocytes to endothelial cells, the initial step in atherosclerosis development, under physiologically-relevant conditions. PMID:26873533

  6. Linking diet, physical activity, cardiorespiratory fitness and obesity to serum metabolite networks: findings from a population-based study

    PubMed Central

    Floegel, A; Wientzek, A; Bachlechner, U; Jacobs, S; Drogan, D; Prehn, C; Adamski, J; Krumsiek, J; Schulze, M B; Pischon, T; Boeing, H

    2014-01-01

    Objective: It is not yet resolved how lifestyle factors and intermediate phenotypes interrelate with metabolic pathways. We aimed to investigate the associations between diet, physical activity, cardiorespiratory fitness and obesity with serum metabolite networks in a population-based study. Methods: The present study included 2380 participants of a randomly drawn subcohort of the European Prospective Investigation into Cancer and Nutrition-Potsdam. Targeted metabolomics was used to measure 127 serum metabolites. Additional data were available including anthropometric measurements, dietary assessment including intake of whole-grain bread, coffee and cake and cookies by food frequency questionnaire, and objectively measured physical activity energy expenditure and cardiorespiratory fitness in a subsample of 100 participants. In a data-driven approach, Gaussian graphical modeling was used to draw metabolite networks and depict relevant associations between exposures and serum metabolites. In addition, the relationship of different exposure metabolite networks was estimated. Results: In the serum metabolite network, the different metabolite classes could be separated. There was a big group of phospholipids and acylcarnitines, a group of amino acids and C6-sugar. Amino acids were particularly positively associated with cardiorespiratory fitness and physical activity. C6-sugar and acylcarnitines were positively associated with obesity and inversely with intake of whole-grain bread. Phospholipids showed opposite associations with obesity and coffee intake. Metabolite networks of coffee intake and obesity were strongly inversely correlated (body mass index (BMI): r=−0.57 and waist circumference: r=−0.59). A strong positive correlation was observed between metabolite networks of BMI and waist circumference (r=0.99), as well as the metabolite networks of cake and cookie intake with cardiorespiratory fitness and intake of whole-grain bread (r=0.52 and r=0

  7. The antitumor activity study of ginsenosides and metabolites in lung cancer cell

    PubMed Central

    Xu, Feng-Yuan; Shang, Wen-Qing; Yu, Jia-Jun; Sun, Qian; Li, Ming-Qing; Sun, Jian-Song

    2016-01-01

    Ginseng and its components exert various biological effects, including antioxidant, anti-carcinogenic, anti-mutagenic, and antitumor activity. Ginsenosides are the main biological components of ginseng. Protopanaxadiol (PPD) and protopanaxatriol (PPT) are two metabolites of ginsenosides. However, the difference between these compounds in anti-lung cancer is unclear. The present study aimed to evaluate the antitumor activity of PPD, PPT, Ginsenosides-Rg3 (G-Rg3) and Ginsenosides-Rh2 (G-Rh2) in lung cancer cell. After treatment with cisplatin, PPD, PPT, G-Rg3 or G-Rh2, the viability, apoptosis level and invasiveness of lung cell lines (A549 cell, a lung adenocarcinoma cell line and SK-MES-1 cell, a lung squamous cell line) in vitro were analyzed by Cell Counting Kit-8 (CCK8), Annexin V/PI apoptosis and Matrigel invasion assays, respectively. Here we found that all these compounds led to significant decreases of viability and invasiveness and an obvious increase of apoptosis of A549 and SK-MES-1 cells. Among these, the viability of SK-MES-1 cell treated with PPT was decreased to 66.8%, and this effect was closest to Cisplatin. G-Rg3 had the highest stimulatory effect on apoptosis, and PTT had the highest inhibitory effect on cell invasiveness in A549 and SK-MES-1 cells. These results indicate that both ginsenosides and two metabolites have antitumor activity on lung cancer cell in vitro. However, PPT is more powerful for inhibiting the viability and invasiveness of lung cancer cell, especially lung squamous cell. G-Rg3 has the best pro-apoptosis effects. This study provides a scientific basis for potential therapeutic strategies targeted to lung cancer by further structure modification. PMID:27186294

  8. Induction of CYP26A1 by Metabolites of Retinoic Acid: Evidence That CYP26A1 Is an Important Enzyme in the Elimination of Active Retinoids

    PubMed Central

    Topletz, Ariel R.; Tripathy, Sasmita; Foti, Robert S.; Shimshoni, Jakob A.; Nelson, Wendel L.

    2015-01-01

    All-trans-retinoic acid (atRA), the active metabolite of vitamin A, induces gene transcription via binding to nuclear retinoic acid receptors (RARs). The primary hydroxylated metabolites formed from atRA by CYP26A1, and the subsequent metabolite 4-oxo-atRA, bind to RARs and potentially have biologic activity. Hence, CYP26A1, the main atRA hydroxylase, may function either to deplete bioactive retinoids or to form active metabolites. This study aimed to determine the role of CYP26A1 in modulating RAR activation via formation and elimination of active retinoids. After treatment of HepG2 cells with atRA, (4S)-OH-atRA, (4R)-OH-atRA, 4-oxo-atRA, and 18-OH-atRA, mRNAs of CYP26A1 and RARβ were increased 300- to 3000-fold, with 4-oxo-atRA and atRA being the most potent inducers. However, >60% of the 4-OH-atRA enantiomers were converted to 4-oxo-atRA in the first 12 hours of treatment, suggesting that the activity of the 4-OH-atRA was due to 4-oxo-atRA. In human hepatocytes, atRA, 4-OH-atRA, and 4-oxo-atRA induced CYP26A1 and 4-oxo-atRA formation was observed from 4-OH-atRA. In HepG2 cells, 4-oxo-atRA formation was observed even in the absence of CYP26A1 activity and this formation was not inhibited by ketoconazole. In human liver microsomes, 4-oxo-atRA formation was supported by NAD+, suggesting that 4-oxo-atRA formation is mediated by a microsomal alcohol dehydrogenase. Although 4-oxo-atRA was not formed by CYP26A1, it was depleted by CYP26A1 (Km = 63 nM and intrinsic clearance = 90 μl/min per pmol). Similarly, CYP26A1 depleted 18-OH-atRA and the 4-OH-atRA enantiomers. These data support the role of CYP26A1 to clear bioactive retinoids, and suggest that the enzyme forming active 4-oxo-atRA may be important in modulating retinoid action. PMID:25492813

  9. The leukotriene B4 paradox: neutrophils can, but will not, respond to ligand-receptor interactions by forming leukotriene B4 or its omega-metabolites.

    PubMed Central

    Haines, K A; Giedd, K N; Rich, A M; Korchak, H M; Weissmann, G

    1987-01-01

    Leukotriene B4 (5S,12R-dihydroxy-6,14-cis,8,10-trans-eicosatetraenoic acid, LTB4) is released from neutrophils exposed to calcium ionophores. To determine whether LTB4 might be produced by ligand-receptor interactions at the plasmalemma, we treated human neutrophils with serum-treated zymosan (STZ), heat-aggregated IgG and fMet-Leu-Phe (fMLP), agonists at the C3b, Fc and fMLP receptors respectively. STZ (10 mg/ml) provoked the formation of barely detectable amounts of LTB4 (0.74 ng/10(7) cells); no omega-oxidized metabolites of LTB4 were found. Adding 10 microM-arachidonate did not significantly increase production of LTB4 or its metabolites. Addition of 50 microM-arachidonate (an amount which activates protein kinase C) before STZ caused a 40-fold increase in the quantity of LTB4 and its omega-oxidation products. Neither phorbol myristate acetate (PMA, 200 ng/ml) nor linoleic acid (50 microM), also activators of protein kinase C, augmented generation of LTB4 by cells stimulated with STZ. Neither fMLP (10(-6) M) nor aggregated IgG (0.3 mg/ml) induced LTB4 formation (less than 0.01 ng/10(7) cells). Moreover, cells exposed to STZ, fMLP, or IgG did not form all-trans-LTB4 or 5-hydroxyeicosatetraenoic acid; their failure to make LTB4 was therefore due to inactivity of neutrophil 5-lipoxygenase. However, adding 50 microM-arachidonate to neutrophil suspensions before fMLP or IgG triggered LTB4 production, the majority of which was metabolized to its omega-oxidized products (fMLP, 20.2 ng/10(7) cells; IgG, 17.1 ng/10(7) cells). The data show that neutrophils exposed to agonists at defined cell-surface receptors produce significant quantities of LTB4 only when treated with non-physiological concentrations of arachidonate. PMID:3032161

  10. Cysteamine, the natural metabolite of pantetheinase, shows specific activity against Plasmodium.

    PubMed

    Min-Oo, Gundula; Ayi, Kodjo; Bongfen, Silayuv E; Tam, Mifong; Radovanovic, Irena; Gauthier, Susan; Santiago, Helton; Rothfuchs, Antonio Gigliotti; Roffê, Ester; Sher, Alan; Mullick, Alaka; Fortin, Anny; Stevenson, Mary M; Kain, Kevin C; Gros, Philippe

    2010-08-01

    In mice, loss of pantetheinase activity causes susceptibility to infection with Plasmodium chabaudi AS. Treatment of mice with the pantetheinase metabolite cysteamine reduces blood-stage replication of P. chabaudi and significantly increases survival. Similarly, a short exposure of Plasmodium to cysteamine ex vivo is sufficient to suppress parasite infectivity in vivo. This effect of cysteamine is specific and not observed with a related thiol (dimercaptosuccinic acid) or with the pantethine precursor of cysteamine. Also, cysteamine does not protect against infection with the parasite Trypanosoma cruzi or the fungal pathogen Candida albicans, suggesting cysteamine acts directly against the parasite and does not modulate host inflammatory response. Cysteamine exposure also blocks replication of P. falciparum in vitro; moreover, these treated parasites show higher levels of intact hemoglobin. This study highlights the in vivo action of cysteamine against Plasmodium and provides further evidence for the involvement of pantetheinase in host response to this infection. PMID:20219464

  11. Cysteamine, the natural metabolite of pantetheinase, shows specific activity against Plasmodium

    PubMed Central

    Min-Oo, Gundula; Ayi, Kodjo; Bongfen, Silayuv E.; Tam, Mifong; Radovanovic, Irena; Gauthier, Susan; Santiago, Helton; Rothfuchs, Antonio Gigliotti; Roffê, Ester; Sher, Alan; Mullick, Alaka; Fortin, Anny; Stevenson, Mary M.; Kain, Kevin C.; Gros, Philippe

    2016-01-01

    In mice, loss of pantetheinase activity causes susceptibility to infection with Plasmodium chabaudi AS. Treatment of mice with the pantetheinase metabolite cysteamine reduces blood-stage replication of P. chabaudi and significantly increases survival. Similarly, a short exposure of Plasmodium to cysteamine ex vivo is sufficient to suppress parasite infectivity in vivo. This effect of cysteamine is specific and not observed with a related thiol (dimercaptosuccinic acid) or with the pantethine precursor of cysteamine. Also, cysteamine does not protect against infection with the parasite Trypanosoma cruzi or the fungal pathogen Candida albicans, suggesting cysteamine acts directly against the parasite and does not modulate host inflammatory response. Cysteamine exposure also blocks replication of P. falciparum in vitro; moreover, these treated parasites show higher levels of intact hemoglobin. This study highlights the in vivo action of cysteamine against Plasmodium and provides further evidence for the involvement of pantetheinase in host response to this infection. PMID:20219464

  12. Chemical diversity of biologically active metabolites in the sclerotia of Inonotus obliquus and submerged culture strategies for up-regulating their production.

    PubMed

    Zheng, Weifa; Miao, Kangjie; Liu, Yubing; Zhao, Yanxia; Zhang, Meimei; Pan, Shenyuan; Dai, Yucheng

    2010-07-01

    Inonotus obliquus (Fr.) Pilat is a white rot fungus belonging to the family Hymenochaetaceae in the Basidiomycota. In nature, this fungus rarely forms a fruiting body but usually an irregular shape of sclerotial conk called 'Chaga'. Characteristically, I. obliquus produces massive melanins released to the surface of Chaga. As early as in the sixteenth century, Chaga was used as an effective folk medicine in Russia and Northern Europe to treat several human malicious tumors and other diseases in the absence of any unacceptable toxic side effects. Chemical investigations show that I. obliquus produces a diverse range of secondary metabolites including phenolic compounds, melanins, and lanostane-type triterpenoids. Among these are the active components for antioxidant, antitumoral, and antiviral activities and for improving human immunity against infection of pathogenic microbes. Geographically, however, this fungus is restricted to very cold habitats and grows very slowly, suggesting that Chaga is not a reliable source of these bioactive compounds. Attempts for culturing this fungus axenically all resulted in a reduced production of bioactive metabolites. This review examines the current progress in the discovery of chemical diversity of Chaga and their biological activities and the strategies to modulate the expression of desired pathways to diversify and up-regulate the production of bioactive metabolites by the fungus grown in submerged cultures for possible drug discovery. PMID:20532760

  13. Evaluation of in vitro antiprotozoal activity of Ajuga laxmannii and its secondary metabolites.

    PubMed

    Atay, Irem; Kirmizibekmez, Hasan; Kaiser, Marcel; Akaydin, Galip; Yesilada, Erdem; Tasdemir, Deniz

    2016-09-01

    Context Some Ajuga L. (Lamiaceae) species are traditionally used for the treatment of malaria, as well as fever, which is a common symptom of many parasitic diseases. Objective In the continuation of our studies on the identification of antiprotozoal secondary metabolites of Turkish Lamiaceae species, we have investigated the aerial parts of Ajuga laxmannii. Materials and methods The aerial parts of A. laxmannii were extracted with MeOH. The H2O subextract was subjected to polyamide, C18-MPLC and SiO2 CCs to yield eight metabolites. The structures of the isolates were elucidated by NMR spectroscopy and MS analyses. The extract, subextracts as well as the isolates were tested for their in vitro antiprotozoal activities against Plasmodium falciparum, Trypanasoma brucei rhodesiense, T. cruzi and Leishmania donovani at concentrations of 90-0.123 μg/mL. Results Two iridoid glycosides harpagide (1) and 8-O-acetylharpagide (2), three o-coumaric acid derivatives cis-melilotoside (3), trans-melilotoside (4) and dihydromelilotoside (5), two phenylethanoid glycosides verbascoside (6) and galactosylmartynoside (7) and a flavone-C-glycoside, isoorientin (8) were isolated. Many compounds showed moderate to good antiparasitic activity, with isoorientin (8) displaying the most significant antimalarial potential (an IC50 value of 9.7 μg/mL). Discussion and conclusion This is the first report on the antiprotozoal evaluation of A. laxmannii extracts and isolates. Furthermore, isoorientin and dihydromelilotoside are being reported for the first time from the genus Ajuga. PMID:26734766

  14. Metabolite fingerprinting of pennycress (Thlaspi arvense L.) embryos to assess active pathways during oil synthesis

    PubMed Central

    Tsogtbaatar, Enkhtuul; Cocuron, Jean-Christophe; Sonera, Marcos Corchado; Alonso, Ana Paula

    2015-01-01

    Pennycress (Thlaspi arvense L.), a plant naturalized to North America, accumulates high levels of erucic acid in its seeds, which makes it a promising biodiesel and industrial crop. The main carbon sinks in pennycress embryos were found to be proteins, fatty acids, and cell wall, which respectively represented 38.5, 33.2, and 27.0% of the biomass at 21 days after pollination. Erucic acid reached a maximum of 36% of the total fatty acids. Together these results indicate that total oil and erucic acid contents could be increased to boost the economic competitiveness of this crop. Understanding the biochemical basis of oil synthesis in pennycress embryos is therefore timely and relevant to guide future breeding and/or metabolic engineering efforts. For this purpose, a combination of metabolomics approaches was conducted to assess the active biochemical pathways during oil synthesis. First, gas chromatography–mass spectrometry (GC-MS) profiling of intracellular metabolites highlighted three main families of compounds: organic acids, amino acids, and sugars/sugar alcohols. Secondly, these intermediates were quantified in developing pennycress embryos by liquid chromatography–tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring mode. Finally, partitional clustering analysis grouped the intracellular metabolites that shared a similar pattern of accumulation over time into eight clusters. This study underlined that: (i) sucrose might be stored rather than cleaved into hexoses; (ii) glucose and glutamine would be the main sources of carbon and nitrogen, respectively; and (iii) glycolysis, the oxidative pentose phosphate pathway, the tricarboxylic acid cycle, and the Calvin cycle were active in developing pennycress embryos. PMID:25711705

  15. Metabolite fingerprinting of pennycress (Thlaspi arvense L.) embryos to assess active pathways during oil synthesis.

    PubMed

    Tsogtbaatar, Enkhtuul; Cocuron, Jean-Christophe; Sonera, Marcos Corchado; Alonso, Ana Paula

    2015-07-01

    Pennycress (Thlaspi arvense L.), a plant naturalized to North America, accumulates high levels of erucic acid in its seeds, which makes it a promising biodiesel and industrial crop. The main carbon sinks in pennycress embryos were found to be proteins, fatty acids, and cell wall, which respectively represented 38.5, 33.2, and 27.0% of the biomass at 21 days after pollination. Erucic acid reached a maximum of 36% of the total fatty acids. Together these results indicate that total oil and erucic acid contents could be increased to boost the economic competitiveness of this crop. Understanding the biochemical basis of oil synthesis in pennycress embryos is therefore timely and relevant to guide future breeding and/or metabolic engineering efforts. For this purpose, a combination of metabolomics approaches was conducted to assess the active biochemical pathways during oil synthesis. First, gas chromatography-mass spectrometry (GC-MS) profiling of intracellular metabolites highlighted three main families of compounds: organic acids, amino acids, and sugars/sugar alcohols. Secondly, these intermediates were quantified in developing pennycress embryos by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring mode. Finally, partitional clustering analysis grouped the intracellular metabolites that shared a similar pattern of accumulation over time into eight clusters. This study underlined that: (i) sucrose might be stored rather than cleaved into hexoses; (ii) glucose and glutamine would be the main sources of carbon and nitrogen, respectively; and (iii) glycolysis, the oxidative pentose phosphate pathway, the tricarboxylic acid cycle, and the Calvin cycle were active in developing pennycress embryos. PMID:25711705

  16. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR

    PubMed Central

    Fedorova, Elena V.; Krylova, Julia V.

    2016-01-01

    The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L.) Sm., and two species of submergent macrophyte groups, Ceratophyllum demersum L. and Potamogeton obtusifolius (Mert. et Koch), for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological significance and a certain universalism in their use by various species of water plants for the implementation of ecological and biochemical functions. This report underlines the role of identified compounds not only as important components in regulation of biochemical and metabolic pathways and processes in aquatic ecological systems, but also as potential pharmacological agents in the fight against different diseases. PMID:27200207

  17. Antiproliferative, Antibacterial and Antifungal Activity of the Lichen Xanthoria parietina and Its Secondary Metabolite Parietin

    PubMed Central

    Basile, Adriana; Rigano, Daniela; Loppi, Stefano; Di Santi, Annalisa; Nebbioso, Angela; Sorbo, Sergio; Conte, Barbara; Paoli, Luca; De Ruberto, Francesca; Molinari, Anna Maria; Altucci, Lucia; Bontempo, Paola

    2015-01-01

    Lichens are valuable natural resources used for centuries throughout the world as medicine, food, fodder, perfume, spices and dyes, as well as for other miscellaneous purposes. This study investigates the antiproliferative, antibacterial and antifungal activity of the acetone extract of the lichen Xanthoria parietina (Linnaeus) Theodor Fries and its major secondary metabolite, parietin. The extract and parietin were tested for antimicrobial activity against nine American Type Culture Collection standard and clinically isolated bacterial strains, and three fungal strains. Both showed strong antibacterial activity against all bacterial strains and matched clinical isolates, particularly against Staphylococcus aureus from standard and clinical sources. Among the fungi tested, Rhizoctonia solani was the most sensitive. The antiproliferative effects of the extract and parietin were also investigated in human breast cancer cells. The extract inhibited proliferation and induced apoptosis, both effects being accompanied by modulation of expression of cell cycle regulating genes such as p16, p27, cyclin D1 and cyclin A. It also mediated apoptosis by activating extrinsic and intrinsic cell death pathways, modulating Tumor Necrosis Factor-related apoptosis-inducing ligand (TRAIL) and B-cell lymphoma 2 (Bcl-2), and inducing Bcl-2-associated agonist of cell death (BAD) phosphorylation. Our results indicate that Xanthoria parietina is a major potential source of antimicrobial and anticancer substances. PMID:25860944

  18. Antiproliferative, antibacterial and antifungal activity of the lichen Xanthoria parietina and its secondary metabolite parietin.

    PubMed

    Basile, Adriana; Rigano, Daniela; Loppi, Stefano; Di Santi, Annalisa; Nebbioso, Angela; Sorbo, Sergio; Conte, Barbara; Paoli, Luca; De Ruberto, Francesca; Molinari, Anna Maria; Altucci, Lucia; Bontempo, Paola

    2015-01-01

    Lichens are valuable natural resources used for centuries throughout the world as medicine, food, fodder, perfume, spices and dyes, as well as for other miscellaneous purposes. This study investigates the antiproliferative, antibacterial and antifungal activity of the acetone extract of the lichen Xanthoria parietina (Linnaeus) Theodor Fries and its major secondary metabolite, parietin. The extract and parietin were tested for antimicrobial activity against nine American Type Culture Collection standard and clinically isolated bacterial strains, and three fungal strains. Both showed strong antibacterial activity against all bacterial strains and matched clinical isolates, particularly against Staphylococcus aureus from standard and clinical sources. Among the fungi tested, Rhizoctonia solani was the most sensitive. The antiproliferative effects of the extract and parietin were also investigated in human breast cancer cells. The extract inhibited proliferation and induced apoptosis, both effects being accompanied by modulation of expression of cell cycle regulating genes such as p16, p27, cyclin D1 and cyclin A. It also mediated apoptosis by activating extrinsic and intrinsic cell death pathways, modulating Tumor Necrosis Factor-related apoptosis-inducing ligand (TRAIL) and B-cell lymphoma 2 (Bcl-2), and inducing Bcl-2-associated agonist of cell death (BAD) phosphorylation. Our results indicate that Xanthoria parietina is a major potential source of antimicrobial and anticancer substances. PMID:25860944

  19. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR.

    PubMed

    Kurashov, Evgeny A; Fedorova, Elena V; Krylova, Julia V; Mitrukova, Galina G

    2016-01-01

    The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L.) Sm., and two species of submergent macrophyte groups, Ceratophyllum demersum L. and Potamogeton obtusifolius (Mert. et Koch), for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological significance and a certain universalism in their use by various species of water plants for the implementation of ecological and biochemical functions. This report underlines the role of identified compounds not only as important components in regulation of biochemical and metabolic pathways and processes in aquatic ecological systems, but also as potential pharmacological agents in the fight against different diseases. PMID:27200207

  20. Multiple active forms of thrombin. IV. Relative activities of meizothrombins

    SciTech Connect

    Doyle, M.F.; Mann, K.G. )

    1990-06-25

    The prothrombin activation intermediates meizothrombin and meizothrombin(desF1) (meizothrombin that has been autoproteolyzed to remove fragment 1) have been obtained in a relatively pure, active form with minimal autolysis, making them suitable for enzymatic characterization. When compared at equimolar concentrations, alpha-thrombin, fragment 1.2+ alpha-thrombin, meizothrombin(desF1), and meizothrombin have approximately 100, 100, 10, and 1% activity, respectively, toward the macromolecular substrates factor V, fibrinogen, and platelets. The difference in activity of these four enzymes cannot be attributed to alterations in the catalytic triad, as all four enzymes have nearly identical catalytic efficiency toward the chromogenic substrate S2238. Further, the ability of meizothrombin and meizothrombin(desF1) to activate protein C was 75% of the activity exhibited by alpha-thrombin or fragment 1.2+ alpha-thrombin. All four enzymes bind to thrombomodulin, as judged by the enhanced rate of protein C activation upon preincubation of the enzymes with thrombomodulin. The extent of rate enhancement varied, with meizothrombin/thrombomodulin exhibiting only 50% of the alpha-thrombin/thrombomodulin rate. This difference in rate is not due to a decreased affinity of the meizothrombin for thrombomodulin since the apparent dissociation constants for the alpha-thrombin-thrombomodulin complex and the meizothrombin-thrombomodulin complex are virtually identical. The difference in the observed rate is due in part to the higher Km for protein C exhibited by the meizothrombin-thrombomodulin complex. Incubation of the thrombomodulin-enzyme complex with phospholipid vesicles caused an increase in the protein C activation rates. The kinetic constants for protein C activation in the presence of phospholipid are virtually identical for these enzyme-thrombomodulin complexes.

  1. A Practical Strategy to Discover New Antitumor Compounds by Activating Silent Metabolite Production in Fungi by Diethyl Sulphate Mutagenesis

    PubMed Central

    Fang, Shi-Ming; Wu, Chang-Jing; Li, Chang-Wei; Cui, Cheng-Bin

    2014-01-01

    Many fungal biosynthetic pathways are silent in standard culture conditions, and activation of the silent pathways may enable access to new metabolites with antitumor activities. The aim of the present study was to develop a practical strategy for microbial chemists to access silent metabolites in fungi. We demonstrated this strategy using a marine-derived fungus Penicillium purpurogenum G59 and a modified diethyl sulphate mutagenesis procedure. Using this strategy, we discovered four new antitumor compounds named penicimutanolone (1), penicimutanin A (2), penicimutanin B (3), and penicimutatin (4). Structures of the new compounds were elucidated by spectroscopic methods, especially extensive 2D NMR analysis. Antitumor activities were assayed by the MTT method using human cancer cell lines. Bioassays and HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses were used to estimate the activated secondary metabolite production. Compounds 2 and 3 had novel structures, and 1 was a new compound belonging to a class of very rare natural products from which only four members are so far known. Compounds 1–3 inhibited several human cancer cell lines with IC50 values lower than 20 μM, and 4 inhibited the cell lines to some extent. These results demonstrated the effectiveness of this strategy to discover new compounds by activating silent fungal metabolic pathways. These discoveries provide rationale for the increased use of chemical mutagenesis strategies in silent fungal metabolite studies. PMID:24681631

  2. Integrated semi-physiological pharmacokinetic model for both sunitinib and its active metabolite SU12662

    PubMed Central

    Yu, Huixin; Steeghs, Neeltje; Kloth, Jacqueline S L; de Wit, Djoeke; van Hasselt, J G Coen; van Erp, Nielka P; Beijnen, Jos H; Schellens, Jan H M; Mathijssen, Ron H J; Huitema, Alwin D R

    2015-01-01

    Aims Previously published pharmacokinetic (PK) models for sunitinib and its active metabolite SU12662 were based on a limited dataset or lacked important elements such as correlations between sunitinib and its metabolite. The current study aimed to develop an improved PK model that circumvented these limitations and to prove the utility of the PK model in treatment optimization in clinical practice. Methods One thousand two hundred and five plasma samples from 70 cancer patients were collected from three PK studies with sunitinib and SU12662. A semi-physiological PK model for sunitinib and SU12662 was developed incorporating pre-systemic metabolism using non-linear mixed effects modelling (nonmem). Allometric scaling based on body weight was applied. The final model was used for simulation of the PK of different treatment regimens. Results Sunitinib and SU12662 PK were best described by a one and two compartment model, respectively. Introduction of pre-systemic formation of SU12662 strongly improved model fit, compared with solely systemic metabolism. The clearance of sunitinib and SU12662 was estimated at 35.7 (relative standard error (RSE) 5.7%) l h−1 and 17.1 (RSE 7.4%) l h−1, respectively for 70 kg patients. Correlation coefficients were estimated between inter-individual variability of both clearances, both volumes of distribution and between clearance and volume of distribution of SU12662 as 0.53, 0.48 and 0.45, respectively. Simulation of the PK model predicted correctly the ratio of patients who did not reach proposed PK targets for efficacy. Conclusions A semi-physiological PK model for sunitinib and SU12662 in cancer patients was presented including pre-systemic metabolism. The model was superior to previous PK models in many aspects. PMID:25393890

  3. Metabolism of 20(S)-Ginsenoside Rg₂ by Rat Liver Microsomes: Bioactivation to SIRT1-Activating Metabolites.

    PubMed

    Ma, Li-Yuan; Zhou, Qi-Le; Yang, Xin-Bao; Wang, Hong-Ping; Yang, Xiu-Wei

    2016-01-01

    20(S)-Ginsenoside Rg₂ (1) has recently become a hot research topic due to its potent bioactivities and abundance in natural sources such as the roots, rhizomes and stems-leaves of Panax ginseng. However, due to the lack of studies on systematic metabolic profiles, the prospects for new drug development of 1 are still difficult to predict, which has become a huge obstacle for its safe clinical use. To solve this problem, investigation of the metabolic profiles of 1 in rat liver microsomes was first carried out. To identify metabolites, a strategy of combined analyses based on prepared metabolites by column chromatography and ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS) was performed. As a result, four metabolites M1-M4, including a rare new compound named ginsenotransmetin A (M1), were isolated and the structures were confirmed by spectroscopic analyses. A series of metabolites of 1, MA-MG, were also tentatively identified by UPLC-Q-TOF/MS in rat liver microsomal incubate of 1. Partial metabolic pathways were proposed. Among them, 1 and its metabolites M1, M3 and M4 were discovered for the first time to be activators of SIRT1. The SIRT1 activating effects of the metabolite M1 was comparable to those of 1, while the most interesting SIRT1 activatory effects of M3 and M4 were higher than that of 1 and comparable with that of resveratrol, a positive SIRT1 activator. These results indicate that microsome-dependent metabolism may represent a bioactivation pathway for 1. This study is the first to report the metabolic profiles of 1 in vitro, and the results provide an experimental foundation to better understand the in vivo metabolic fate of 1. PMID:27294899

  4. Dietary Epicatechin Is Available to Breastfed Infants through Human Breast Milk in the Form of Host and Microbial Metabolites.

    PubMed

    Khymenets, Olha; Rabassa, Montserrat; Rodríguez-Palmero, María; Rivero-Urgell, Montserrat; Urpi-Sarda, Mireia; Tulipani, Sara; Brandi, Pilar; Campoy, Cristina; Santos-Buelga, Celestino; Andres-Lacueva, Cristina

    2016-07-01

    Polyphenols play an important role in human health. To address their accessibility to a breastfed infant, we planned to evaluate whether breast milk (BM) (colostrum, transitional, and mature) epicatechin metabolites could be related to the dietary habits of mothers. The polyphenol consumption of breastfeeding mothers was estimated using a food frequency questionnaire and 24 h recalls. Solid-phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) was applied for direct epicatechin metabolite analysis. Their bioavailability in BM as a result of dietary ingestion was confirmed in a preliminary experiment with a single dose of dark chocolate. Several host and microbial phase II metabolites of epicatechin were detected in BM among free-living lactating mothers. Interestingly, a modest correlation between dihydroxyvalerolactone sulfate and the intake of cocoa products was observed. Although a very low percentage of dietary polyphenols is excreted in BM, they are definitely in the diet of breastfed infants. Therefore, evaluation of their role in infant health could be further promoted. PMID:27285570

  5. Cytotoxic, Antiangiogenic and Antitelomerase Activity of Glucosyl- and Acyl- Resveratrol Prodrugs and Resveratrol Sulfate Metabolites.

    PubMed

    Falomir, Eva; Lucas, Ricardo; Peñalver, Pablo; Martí-Centelles, Rosa; Dupont, Alexia; Zafra-Gómez, Alberto; Carda, Miguel; Morales, Juan C

    2016-07-15

    Resveratrol (RES) is a natural polyphenol with relevant and varied biological activity. However, its low bioavailability and rapid metabolism to its glucuronate and sulfate conjugates has opened a debate on the mechanisms underlying its bioactivity. RES prodrugs are being developed to overcome these problems. We have synthesized a series of RES prodrugs and RES sulfate metabolites (RES-S) and evaluated their biological activities. RES glucosylated prodrugs (RES-Glc) were more cytotoxic in HT-29 and MCF-7 cells than RES itself whereas RES-S showed similar or higher cytotoxicity than RES. VEGF production was decreased by RES-Glc, and RES-disulfate (RES-diS) diminished it even more than RES. Finally, RES-Glc and RES-diS inhibited hTERT gene expression to a higher extent than RES. In conclusion, resveratrol prodrugs are promising candidates as anticancer drugs. In addition, RES-S showed distinct biological activity, thus indicating they are not simply RES reservoirs. PMID:27147200

  6. Antifungal activity of metabolites of the endophytic fungus Trichoderma brevicompactum from garlic

    PubMed Central

    Shentu, Xuping; Zhan, Xiaohuan; Ma, Zheng; Yu, Xiaoping; Zhang, Chuanxi

    2014-01-01

    The endophytic fungus strain 0248, isolated from garlic, was identified as Trichoderma brevicompactum based on morphological characteristics and the nucleotide sequences of ITS1-5.8S- ITS2 and tef1. The bioactive compound T2 was isolated from the culture extracts of this fungus by bioactivity-guided fractionation and identified as 4β-acetoxy-12,13- epoxy-Δ9-trichothecene (trichodermin) by spectral analysis and mass spectrometry. Trichodermin has a marked inhibitory activity on Rhizoctonia solani, with an EC50 of 0.25 μgmL−1. Strong inhibition by trichodermin was also found for Botrytis cinerea, with an EC50 of 2.02 μgmL−1. However, a relatively poor inhibitory effect was observed for trichodermin against Colletotrichum lindemuthianum (EC50 = 25.60 μgmL−1). Compared with the positive control Carbendazim, trichodermin showed a strong antifungal activity on the above phytopathogens. There is little known about endophytes from garlic. This paper studied in detail the identification of endophytic T. brevicompactum from garlic and the characterization of its active metabolite trichodermin. PMID:24948941

  7. Effect of Competition on the Production and Activity of Secondary Metabolites in Aspergillus species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Secondary metabolites are of intense interest to humans due to their pharmaceutical and/or toxic properties. Aspergillus species secrete these metabolites by themselves and in the presence of other fungal species. Here, we have performed co-cultivation competition assays among different Aspergillu...

  8. Increased active metabolite formation explains the greater platelet inhibition with prasugrel compared to high-dose clopidogrel.

    PubMed

    Payne, Christopher D; Li, Ying Grace; Small, David S; Ernest, C Steven; Farid, Nagy A; Jakubowski, Joseph A; Brandt, John T; Salazar, Daniel E; Winters, Kenneth J

    2007-11-01

    Prasugrel pharmacodynamics and pharmacokinetics after a 60-mg loading dose (LD) and daily 10-mg maintenance doses (MD) were compared in a 3-way crossover study to clopidogrel 600-mg/75-mg and 300-mg/75-mg LD/MD in 41 healthy, aspirin-free subjects. Each LD was followed by 7 days of daily MD and a 14-day washout period. Inhibition of platelet aggregation (IPA) was assessed by turbidometric aggregometry (20 and 5 microM ADP). Prasugrel 60-mg achieved higher mean IPA (54%) 30 minutes post-LD than clopidogrel 300-mg (3%) or 600-mg (6%) (P < 0.001) and greater IPA by 1 hour (82%) and 2 hours (91%) than the 6-hour IPA for clopidogrel 300-mg (51%) or 600-mg (69%) (P < 0.01). During MD, IPA for prasugrel 10-mg (78%) exceeded that of clopidogrel (300-mg/75-mg, 56%; 600-mg/75-mg, 52%; P < 0.001). Active metabolite area under the concentration-time curve (AUC0-tlast) after prasugrel 60-mg (594 ng.hr/mL) was 2.2 times that after clopidogrel 600-mg. Prasugrel active metabolite AUC0-tlast was consistent with dose-proportionality from 10-mg to 60-mg, while clopidogrel active metabolite AUC0-tlast exhibited saturable absorption and/or metabolism. In conclusion, greater exposure to prasugrel's active metabolite results in faster onset, higher levels, and less variability of platelet inhibition compared with high-dose clopidogrel in healthy subjects. PMID:18030066

  9. Endoxifen, the active metabolite of tamoxifen, inhibits cloned hERG potassium channels.

    PubMed

    Chae, Yun Ju; Lee, Keon Jin; Lee, Hong Joon; Sung, Ki-Wug; Choi, Jin-Sung; Lee, Eun Hui; Hahn, Sang June

    2015-04-01

    The effects of tamoxifen, and its active metabolite endoxifen (4-hydroxy-N-desmethyl-tamoxifen), on hERG currents stably expressed in HEK cells were investigated using the whole-cell patch-clamp technique and an immunoblot assay. Tamoxifen and endoxifen inhibited hERG tail currents at -50mV in a concentration-dependent manner with IC50 values of 1.2 and 1.6μM, respectively. The steady-state activation curve of the hERG currents was shifted to the hyperpolarizing direction in the presence of endoxifen. The voltage-dependent inhibition of hERG currents by endoxifen increased steeply in the voltage range of channel activation. The inhibition by endoxifen displayed a shallow voltage dependence (δ=0.18) in the full activation voltage range. A fast application of endoxifen induced a reversible block of hERG tail currents during repolarization in a concentration-dependent manner, which suggested an interaction with the open state of the channel. Endoxifen also decreased the hERG current elicited by a 5s depolarizing pulse to +60mV to inactivate the hERG currents, suggesting an interaction with the activated (open and/or inactivated) states of the channels. Tamoxifen and endoxifen inhibited the hERG channel protein trafficking to the plasma membrane in a concentration-dependent manner with endoxifen being more potent than tamoxifen. These results indicated that tamoxifen and endoxifen inhibited the hERG current by direct channel blockage and by the disruption of channel trafficking to the plasma membrane in a concentration-dependent manner. A therapeutic concentration of endoxifen inhibited the hERG current by preferentially interacting with the activated (open and/or inactivated) states of the channel. PMID:25680947

  10. Lack of metabolic activation and predominant formation of an excreted metabolite of nontoxic platynecine-type pyrrolizidine alkaloids.

    PubMed

    Ruan, Jianqing; Liao, Cangsong; Ye, Yang; Lin, Ge

    2014-01-21

    Pyrrolizidine alkaloid (PA) poisoning is well-known because of the intake of PA-containing plant-derived natural products and PA-contaminated foodstuffs. Based on different structures of the necine bases, PAs are classified into three types: retronecine, otonecine, and platynecine type. The former two type PAs possessing an unsaturated necine base with a 1,2-double bond are hepatotoxic due to the P450-mediated metabolic activation to generate reactive pyrrolic ester, which interacts with cellular macromolecules leading to toxicity. With a saturated necine base, platynecine-type PAs are reported to be nontoxic and their nontoxicity was hypothesized to be due to the absence of metabolic activation; however, the metabolic pathway responsible for their nontoxic nature is largely unknown. In the present study, to prove the absence of metabolic activation in nontoxic platynecine-type PAs, hepatic metabolism of platyphylline (PLA), a representative platynecine-type PA, was investigated and directly compared with the representatives of two toxic types of PAs in parallel. By determining the pyrrolic ester-derived glutathione conjugate, our results confirmed that the major metabolic pathway of PLA did not lead to formation of the reactive pyrrolic ester. More interestingly, having a metabolic rate similar to that of toxic PAs, PLA also underwent oxidative metabolisms mediated by P450s, especially P450 3A4, the same enzyme that catalyzes metabolic activation of two toxic types of PAs. However, the predominant oxidative dehydrogenation pathway of PLA formed a novel metabolite, dehydroplatyphylline carboxylic acid, which was water-soluble, readily excreted, and could not interact with cellular macromolecules. In conclusion, our study confirmed that the saturated necine bases determine the absence of metabolic activation and thus govern the metabolic pathway responsible for the nontoxic nature of platynecine-type PAs. PMID:24308637

  11. Anticancer Activities of Protopanaxadiol- and Protopanaxatriol-Type Ginsenosides and Their Metabolites

    PubMed Central

    Chen, Xiao-Jia; Zhang, Xiao-Jing; Shui, Yan-Mei; Wan, Jian-Bo

    2016-01-01

    Recently, most anticancer drugs are derived from natural resources such as marine, microbial, and botanical sources, but the low success rates of chemotherapies and the development of multidrug resistance emphasize the importance of discovering new compounds that are both safe and effective against cancer. Ginseng types, including Asian ginseng, American ginseng, and notoginseng, have been used traditionally to treat various diseases, due to their immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Accumulating reports have shown that ginsenosides, the major active component of ginseng, were helpful for tumor treatment. 20(S)-Protopanaxadiol (PDS) and 20(S)-protopanaxatriol saponins (PTS) are two characteristic types of triterpenoid saponins in ginsenosides. PTS holds capacity to interfere with crucial metabolism, while PDS could affect cell cycle distribution and prodeath signaling. This review aims at providing an overview of PTS and PDS, as well as their metabolites, regarding their different anticancer effects with the proposal that these compounds might be potent additions to the current chemotherapeutic strategy against cancer. PMID:27446225

  12. Anticancer Activities of Protopanaxadiol- and Protopanaxatriol-Type Ginsenosides and Their Metabolites.

    PubMed

    Chen, Xiao-Jia; Zhang, Xiao-Jing; Shui, Yan-Mei; Wan, Jian-Bo; Gao, Jian-Li

    2016-01-01

    Recently, most anticancer drugs are derived from natural resources such as marine, microbial, and botanical sources, but the low success rates of chemotherapies and the development of multidrug resistance emphasize the importance of discovering new compounds that are both safe and effective against cancer. Ginseng types, including Asian ginseng, American ginseng, and notoginseng, have been used traditionally to treat various diseases, due to their immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Accumulating reports have shown that ginsenosides, the major active component of ginseng, were helpful for tumor treatment. 20(S)-Protopanaxadiol (PDS) and 20(S)-protopanaxatriol saponins (PTS) are two characteristic types of triterpenoid saponins in ginsenosides. PTS holds capacity to interfere with crucial metabolism, while PDS could affect cell cycle distribution and prodeath signaling. This review aims at providing an overview of PTS and PDS, as well as their metabolites, regarding their different anticancer effects with the proposal that these compounds might be potent additions to the current chemotherapeutic strategy against cancer. PMID:27446225

  13. Functional imaging of focal brain activation in conscious rats: impact of [(14)C]glucose metabolite spreading and release.

    PubMed

    Cruz, Nancy F; Ball, Kelly K; Dienel, Gerald A

    2007-11-15

    Labeled glucose and its analogs are widely used in imaging and metabolic studies of brain function, astrocyte-neuron interactions, and neurotransmission. Metabolite shuttling among astrocytes and neurons is essential for cell-cell transfer of neurotransmitter precursors and supply and elimination of energy metabolites, but dispersion and release of labeled compounds from activated tissue would reduce signal registration in metabolic labeling studies, causing underestimation of focal functional activation. Processes and pathways involved in metabolite trafficking and release were therefore assessed in the auditory pathway of conscious rats. Unilateral monotonic stimulation increased glucose utilization (CMR(glc)) in tonotopic bands in the activated inferior colliculus by 35-85% compared with contralateral tissue when assayed with [(14)C]deoxyglucose (DG), whereas only 20-30% increases were registered with [1- or 6-(14)C]glucose. Tonotopic bands were not evident with [1-(14)C]glucose unless assayed during halothane anesthesia or pretreatment with probenecid but were detectable with [6-(14)C]glucose. Extracellular lactate levels transiently doubled during acoustic stimulation, so metabolite spreading was assessed by microinfusion of [(14)C]tracers into the inferior colliculus. The volume of tissue labeled by [1-(14)C]glucose exceeded that by [(14)C]DG by 3.2- and 1.4-fold during rest and acoustic activation, respectively. During activation, the tissue volume labeled by U-(14)C-labeled glutamine and lactate rose, whereas that by glucose fell 50% and that by DG was unchanged. Dispersion of [1-(14)C]glucose and its metabolites during rest was also reduced 50% by preinfusion of gap junction blockers. To summarize, during brain activation focal CMR(glc) is underestimated with labeled glucose because of decarboxylation reactions, spreading within tissue and via the astrocyte syncytium, and release from activated tissue. These findings help explain the fall in CMR(O2)/CMR

  14. 3D-QSAR Studies on a Series of Dihydroorotate Dehydrogenase Inhibitors: Analogues of the Active Metabolite of Leflunomide

    PubMed Central

    Li, Shun-Lai; He, Mao-Yu; Du, Hong-Guang

    2011-01-01

    The active metabolite of the novel immunosuppressive agent leflunomide has been shown to inhibit the enzyme dihydroorotate dehydrogenase (DHODH). This enzyme catalyzes the fourth step in de novo pyrimidine biosynthesis. Self-organizing molecular field analysis (SOMFA), a simple three-dimensional quantitative structure-activity relationship (3D-QSAR) method is used to study the correlation between the molecular properties and the biological activities of a series of analogues of the active metabolite. The statistical results, cross-validated rCV2 (0.664) and non cross-validated r2 (0.687), show a good predictive ability. The final SOMFA model provides a better understanding of DHODH inhibitor-enzyme interactions, and may be useful for further modification and improvement of inhibitors of this important enzyme. PMID:21686163

  15. Synthesis of new optically active propargylic fluorides and application to the enantioselective synthesis of monofluorinated analogues of fatty acid metabolites.

    PubMed

    Prakesch, M; Grée, D; Grée, R

    2001-05-01

    A new approach to obtain optically active unsaturated or polyunsaturated systems with a single fluorine atom in an allylic or propargylic position is reported. Central to this strategy is the high regio- and stereocontrol observed during the fluorination of propargylic alcohols allowing a short and efficient synthesis of 1. Further, simple functional group transformations gave the enals 2 and 3. These three key intermediates were used for the preparation of optically active monofluorinated analogues of fatty acid metabolites. PMID:11325281

  16. A fish-feeding laboratory bioassay to assess the antipredatory activity of secondary metabolites from the tissues of marine organisms.

    PubMed

    Marty, Micah J; Pawlik, Joseph R

    2015-01-01

    Marine chemical ecology is a young discipline, having emerged from the collaboration of natural products chemists and marine ecologists in the 1980s with the goal of examining the ecological functions of secondary metabolites from the tissues of marine organisms. The result has been a progression of protocols that have increasingly refined the ecological relevance of the experimental approach. Here we present the most up-to-date version of a fish-feeding laboratory bioassay that enables investigators to assess the antipredatory activity of secondary metabolites from the tissues of marine organisms. Organic metabolites of all polarities are exhaustively extracted from the tissue of the target organism and reconstituted at natural concentrations in a nutritionally appropriate food matrix. Experimental food pellets are presented to a generalist predator in laboratory feeding assays to assess the antipredatory activity of the extract. The procedure described herein uses the bluehead, Thalassoma bifasciatum, to test the palatability of Caribbean marine invertebrates; however, the design may be readily adapted to other systems. Results obtained using this laboratory assay are an important prelude to field experiments that rely on the feeding responses of a full complement of potential predators. Additionally, this bioassay can be used to direct the isolation of feeding-deterrent metabolites through bioassay-guided fractionation. This feeding bioassay has advanced our understanding of the factors that control the distribution and abundance of marine invertebrates on Caribbean coral reefs and may inform investigations in diverse fields of inquiry, including pharmacology, biotechnology, and evolutionary ecology. PMID:25650625

  17. 76 FR 42129 - Agency Information Collection Activities: Case Submission Form, Case Assistance Form

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ... FY2010. We are requesting a two year approval for the form anticipating Government Paperwork Elimination... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Agency Information Collection Activities: Case Submission Form, Case Assistance Form (Form...

  18. The ex vivo antiplatelet activation potential of fruit phenolic metabolite hippuric acid.

    PubMed

    Santhakumar, Abishek Bommannan; Stanley, Roger; Singh, Indu

    2015-08-01

    Polyphenol-rich fruit and vegetable intake has been associated with reduction in platelet hyperactivity, a significant contributor to thrombus formation. This study was undertaken to investigate the possible role of hippuric acid, a predominant metabolite of plant cyclic polyols, phenolic acids and polyphenols, in reduction of platelet activation-related thrombogenesis. Fasting blood samples were collected from 13 healthy subjects to analyse the effect of varying concentrations of hippuric acid (100 μM, 200 μM, 500 μM, 1 mM and 2 mM) on activation-dependant platelet surface-marker expression. Procaspase activating compound-1 (PAC-1) and P-selectin/CD62P monoclonal antibodies were used to evaluate platelet activation-related conformational changes and α-granule release respectively using flow cytometry. Platelets were stimulated ex vivo via the P2Y1/P2Y12- adenosine diphosphate (ADP) pathway of platelet activation. Hippuric acid at a concentration of 1 mM and 2 mM significantly reduced P-selectin/CD62P expression (p = 0.03 and p < 0.001 respectively) induced by ADP. Hippuric acid at 2 mM concentration also inhibited PAC-1 activation-dependant antibody expression (p = 0.03). High ex vivo concentrations of hippuric acid can therefore significantly reduce P-selectin and PAC-1 expression thus reducing platelet activation and clotting potential. However, although up to 11 mM of hippuric acid can be excreted in the urine per day following consumption of fruit, hippuric acid is actively excreted with a recorded Cmax for hippuric acid in human plasma at 250-300 μM. This is lower than the blood concentration of 1-2 mM shown to be bioactive in this research. The contribution of hippuric acid to the protective effects of fruit and vegetable intake against vascular disorders by the pathways measured is therefore low but could be synergistic with lowered doses of antiplatelet drugs and help reduce risk of thrombosis in current antiplatelet drug sensitive populations. PMID

  19. Cytochrome P450-mediated activation of the fragrance compound geraniol forms potent contact allergens

    SciTech Connect

    Hagvall, Lina; Baron, Jens Malte; Boerje, Anna; Weidolf, Lars; Merk, Hans; Karlberg, Ann-Therese

    2008-12-01

    Contact sensitization is caused by low molecular weight compounds which penetrate the skin and bind to protein. In many cases, these compounds are activated to reactive species, either by autoxidation on exposure to air or by metabolic activation in the skin. Geraniol, a widely used fragrance chemical, is considered to be a weak allergen, although its chemical structure does not indicate it to be a contact sensitizer. We have shown that geraniol autoxidizes and forms allergenic oxidation products. In the literature, it is suggested but not shown that geraniol could be metabolically activated to geranial. Previously, a skin-like CYP cocktail consisting of cutaneous CYP isoenzymes, was developed as a model system to study cutaneous metabolism. In the present study, we used this system to investigate CYP-mediated activation of geraniol. In incubations with the skin-like CYP cocktail, geranial, neral, 2,3-epoxygeraniol, 6,7-epoxygeraniol and 6,7-epoxygeranial were identified. Geranial was the main metabolite formed followed by 6,7-epoxygeraniol. The allergenic activities of the identified metabolites were determined in the murine local lymph node assay (LLNA). Geranial, neral and 6,7-epoxygeraniol were shown to be moderate sensitizers, and 6,7-epoxygeranial a strong sensitizer. Of the isoenzymes studied, CYP2B6, CYP1A1 and CYP3A5 showed high activities. It is likely that CYP1A1 and CYP3A5 are mainly responsible for the metabolic activation of geraniol in the skin, as they are expressed constitutively at significantly higher levels than CYP2B6. Thus, geraniol is activated through both autoxidation and metabolism. The allergens geranial and neral are formed via both oxidation mechanisms, thereby playing a large role in the sensitization to geraniol.

  20. Molecular structure of antihypertensive drug perindopril, its active metabolite perindoprilat and impurity F

    NASA Astrophysics Data System (ADS)

    Remko, M.; Bojarska, J.; Ježko, P.; Maniukiewicz, W.; Olczak, A.

    2013-03-01

    The molecular structure of the antihypertensive drug perindopril (2S,3aS,7aS)-1-[(2S)-2-[[(2S)-1-ethoxy-1-oxopentan-2-yl]amino]propanoyl]-2,3,3a,4,5,6,7,7a-octahydroindole-2 carboxylic acid), its active metabolite perindoprilat ((2S,3aS,7aS)-1-[(2S)-2-[[(2S)-1-carboxybutyl]amino]propanoyl]-2,3,3a,4,5,6,7,7a-octahydroindole-2-carboxylic acid), and impurity F (ethyl (2S)-2-((3S,5aS,9aS,10aS)-3-methyl-1,4-dioxodecahydropyrazino[1,2-a]indol-2(1H)-yl) pentanoate) has been investigated using B3LYP/6-31g(d) and B3LYP/6-311+g(d,p) model chemistry. It has been found that solid state conformations of perindoprilat occur close to, but not actually at minima on the computed gas-phase potential energy surfaces. Both, neutral and zwitterionic structures of perindopril and perindoprilat have been investigated. Relative stability of individual ionized species of this drug has been determined. Water has a remarkable effect on the geometry of the perindopril species studied.

  1. Imaging of Endogenous Metabolites of Plant Leaves by Mass Spectrometry Based on Laser Activated Electron Tunneling

    PubMed Central

    Huang, Lulu; Tang, Xuemei; Zhang, Wenyang; Jiang, Ruowei; Chen, Disong; Zhang, Juan; Zhong, Hongying

    2016-01-01

    A new mass spectrometric imaging approach based on laser activated electron tunneling (LAET) was described and applied to analysis of endogenous metabolites of plant leaves. LAET is an electron-directed soft ionization technique. Compressed thin films of semiconductor nanoparticles of bismuth cobalt zinc oxide were placed on the sample plate for proof-of-principle demonstration because they can not only absorb ultraviolet laser but also have high electron mobility. Upon laser irradiation, electrons are excited from valence bands to conduction bands. With appropriate kinetic energies, photoexcited electrons can tunnel away from the barrier and eventually be captured by charge deficient atoms present in neutral molecules. Resultant unpaired electron subsequently initiates specific chemical bond cleavage and generates ions that can be detected in negative ion mode of the mass spectrometer. LAET avoids the co-crystallization process of routinely used organic matrix materials with analyzes in MALDI (matrix assisted-laser desorption ionization) analysis. Thus uneven distribution of crystals with different sizes and shapes as well as background peaks in the low mass range resulting from matrix molecules is eliminated. Advantages of LAET imaging technique include not only improved spatial resolution but also photoelectron capture dissociation which produces predictable fragment ions. PMID:27053227

  2. Imaging of Endogenous Metabolites of Plant Leaves by Mass Spectrometry Based on Laser Activated Electron Tunneling

    NASA Astrophysics Data System (ADS)

    Huang, Lulu; Tang, Xuemei; Zhang, Wenyang; Jiang, Ruowei; Chen, Disong; Zhang, Juan; Zhong, Hongying

    2016-04-01

    A new mass spectrometric imaging approach based on laser activated electron tunneling (LAET) was described and applied to analysis of endogenous metabolites of plant leaves. LAET is an electron-directed soft ionization technique. Compressed thin films of semiconductor nanoparticles of bismuth cobalt zinc oxide were placed on the sample plate for proof-of-principle demonstration because they can not only absorb ultraviolet laser but also have high electron mobility. Upon laser irradiation, electrons are excited from valence bands to conduction bands. With appropriate kinetic energies, photoexcited electrons can tunnel away from the barrier and eventually be captured by charge deficient atoms present in neutral molecules. Resultant unpaired electron subsequently initiates specific chemical bond cleavage and generates ions that can be detected in negative ion mode of the mass spectrometer. LAET avoids the co-crystallization process of routinely used organic matrix materials with analyzes in MALDI (matrix assisted-laser desorption ionization) analysis. Thus uneven distribution of crystals with different sizes and shapes as well as background peaks in the low mass range resulting from matrix molecules is eliminated. Advantages of LAET imaging technique include not only improved spatial resolution but also photoelectron capture dissociation which produces predictable fragment ions.

  3. Imaging of Endogenous Metabolites of Plant Leaves by Mass Spectrometry Based on Laser Activated Electron Tunneling.

    PubMed

    Huang, Lulu; Tang, Xuemei; Zhang, Wenyang; Jiang, Ruowei; Chen, Disong; Zhang, Juan; Zhong, Hongying

    2016-01-01

    A new mass spectrometric imaging approach based on laser activated electron tunneling (LAET) was described and applied to analysis of endogenous metabolites of plant leaves. LAET is an electron-directed soft ionization technique. Compressed thin films of semiconductor nanoparticles of bismuth cobalt zinc oxide were placed on the sample plate for proof-of-principle demonstration because they can not only absorb ultraviolet laser but also have high electron mobility. Upon laser irradiation, electrons are excited from valence bands to conduction bands. With appropriate kinetic energies, photoexcited electrons can tunnel away from the barrier and eventually be captured by charge deficient atoms present in neutral molecules. Resultant unpaired electron subsequently initiates specific chemical bond cleavage and generates ions that can be detected in negative ion mode of the mass spectrometer. LAET avoids the co-crystallization process of routinely used organic matrix materials with analyzes in MALDI (matrix assisted-laser desorption ionization) analysis. Thus uneven distribution of crystals with different sizes and shapes as well as background peaks in the low mass range resulting from matrix molecules is eliminated. Advantages of LAET imaging technique include not only improved spatial resolution but also photoelectron capture dissociation which produces predictable fragment ions. PMID:27053227

  4. Exploring the chemodiversity and biological activities of the secondary metabolites from the marine fungus Neosartorya pseudofischeri.

    PubMed

    Liang, Wan-Ling; Le, Xiu; Li, Hou-Jin; Yang, Xiang-Ling; Chen, Jun-Xiong; Xu, Jun; Liu, Huan-Liang; Wang, Lai-You; Wang, Kun-Teng; Hu, Kun-Chao; Yang, De-Po; Lan, Wen-Jian

    2014-11-01

    The production of fungal metabolites can be remarkably influenced by various cultivation parameters. To explore the biosynthetic potentials of the marine fungus, Neosartorya pseudofischeri, which was isolated from the inner tissue of starfish Acanthaster planci, glycerol-peptone-yeast extract (GlyPY) and glucose-peptone-yeast extract (GluPY) media were used to culture this fungus. When cultured in GlyPY medium, this fungus produced two novel diketopiperazines, neosartins A and B (1 and 2), together with six biogenetically-related known diketopiperazines,1,2,3,4-tetrahydro-2, 3-dimethyl-1,4-dioxopyrazino[1,2-a]indole (3), 1,2,3,4-tetrahydro-2-methyl-3-methylen e-1,4-dioxopyrazino[1,2-a]indole (4), 1,2,3,4-tetrahydro-2-methyl-1,3,4-trioxopyrazino[1,2-a] indole (5), 6-acetylbis(methylthio)gliotoxin (10), bisdethiobis(methylthio)gliotoxin (11), didehydrobisdethiobis(methylthio)gliotoxin (12) and N-methyl-1H-indole-2-carboxamide (6). However, a novel tetracyclic-fused alkaloid, neosartin C (14), a meroterpenoid, pyripyropene A (15), gliotoxin (7) and five known gliotoxin analogues, acetylgliotoxin (8), reduced gliotoxin (9), 6-acetylbis(methylthio)gliotoxin (10), bisdethiobis(methylthio) gliotoxin (11) and bis-N-norgliovictin (13), were obtained when grown in glucose-containing medium (GluPY medium). This is the first report of compounds 3, 4, 6, 9, 10 and 12 as naturally occurring. Their structures were determined mainly by MS, 1D and 2D NMR data. The possible biosynthetic pathways of gliotoxin-related analogues and neosartin C were proposed. The antibacterial activity of compounds 2-14 and the cytotoxic activity of compounds 4, 5 and 7-13 were evaluated. Their structure-activity relationships are also preliminarily discussed. PMID:25421322

  5. Exploring the Chemodiversity and Biological Activities of the Secondary Metabolites from the Marine Fungus Neosartorya pseudofischeri

    PubMed Central

    Liang, Wan-Ling; Le, Xiu; Li, Hou-Jin; Yang, Xiang-Ling; Chen, Jun-Xiong; Xu, Jun; Liu, Huan-Liang; Wang, Lai-You; Wang, Kun-Teng; Hu, Kun-Chao; Yang, De-Po; Lan, Wen-Jian

    2014-01-01

    The production of fungal metabolites can be remarkably influenced by various cultivation parameters. To explore the biosynthetic potentials of the marine fungus, Neosartorya pseudofischeri, which was isolated from the inner tissue of starfish Acanthaster planci, glycerol-peptone-yeast extract (GlyPY) and glucose-peptone-yeast extract (GluPY) media were used to culture this fungus. When cultured in GlyPY medium, this fungus produced two novel diketopiperazines, neosartins A and B (1 and 2), together with six biogenetically-related known diketopiperazines,1,2,3,4-tetrahydro-2,3-dimethyl-1,4-dioxopyrazino[1,2-a]indole (3), 1,2,3,4-tetrahydro-2-methyl-3-methylene-1,4-dioxopyrazino[1,2-a]indole (4), 1,2,3,4-tetrahydro-2-methyl-1,3,4-trioxopyrazino[1,2-a] indole (5), 6-acetylbis(methylthio)gliotoxin (10), bisdethiobis(methylthio)gliotoxin (11), didehydrobisdethiobis(methylthio)gliotoxin (12) and N-methyl-1H-indole-2-carboxamide (6). However, a novel tetracyclic-fused alkaloid, neosartin C (14), a meroterpenoid, pyripyropene A (15), gliotoxin (7) and five known gliotoxin analogues, acetylgliotoxin (8), reduced gliotoxin (9), 6-acetylbis(methylthio)gliotoxin (10), bisdethiobis(methylthio) gliotoxin (11) and bis-N-norgliovictin (13), were obtained when grown in glucose-containing medium (GluPY medium). This is the first report of compounds 3, 4, 6, 9, 10 and 12 as naturally occurring. Their structures were determined mainly by MS, 1D and 2D NMR data. The possible biosynthetic pathways of gliotoxin-related analogues and neosartin C were proposed. The antibacterial activity of compounds 2–14 and the cytotoxic activity of compounds 4, 5 and 7–13 were evaluated. Their structure-activity relationships are also preliminarily discussed. PMID:25421322

  6. Aspirin's Active Metabolite Salicylic Acid Targets High Mobility Group Box 1 to Modulate Inflammatory Responses.

    PubMed

    Choi, Hyong Woo; Tian, Miaoying; Song, Fei; Venereau, Emilie; Preti, Alessandro; Park, Sang-Wook; Hamilton, Keith; Swapna, G V T; Manohar, Murli; Moreau, Magali; Agresti, Alessandra; Gorzanelli, Andrea; De Marchis, Francesco; Wang, Huang; Antonyak, Marc; Micikas, Robert J; Gentile, Daniel R; Cerione, Richard A; Schroeder, Frank C; Montelione, Gaetano T; Bianchi, Marco E; Klessig, Daniel F

    2015-01-01

    Salicylic acid (SA) and its derivatives have been used for millennia to reduce pain, fever and inflammation. In addition, prophylactic use of acetylsalicylic acid, commonly known as aspirin, reduces the risk of heart attack, stroke and certain cancers. Because aspirin is rapidly de-acetylated by esterases in human plasma, much of aspirin's bioactivity can be attributed to its primary metabolite, SA. Here we demonstrate that human high mobility group box 1 (HMGB1) is a novel SA-binding protein. SA-binding sites on HMGB1 were identified in the HMG-box domains by nuclear magnetic resonance (NMR) spectroscopic studies and confirmed by mutational analysis. Extracellular HMGB1 is a damage-associated molecular pattern molecule (DAMP), with multiple redox states. SA suppresses both the chemoattractant activity of fully reduced HMGB1 and the increased expression of proinflammatory cytokine genes and cyclooxygenase 2 (COX-2) induced by disulfide HMGB1. Natural and synthetic SA derivatives with greater potency for inhibition of HMGB1 were identified, providing proof-of-concept that new molecules with high efficacy against sterile inflammation are attainable. An HMGB1 protein mutated in one of the SA-binding sites identified by NMR chemical shift perturbation studies retained chemoattractant activity, but lost binding of and inhibition by SA and its derivatives, thereby firmly establishing that SA binding to HMGB1 directly suppresses its proinflammatory activities. Identification of HMGB1 as a pharmacological target of SA/aspirin provides new insights into the mechanisms of action of one of the world's longest and most used natural and synthetic drugs. It may also provide an explanation for the protective effects of low-dose aspirin usage. PMID:26101955

  7. Cytotoxicity and characterization of an active metabolite of benzamide riboside, a novel inhibitor of IMP dehydrogenase.

    PubMed

    Gharehbaghi, K; Paull, K D; Kelley, J A; Barchi, J J; Marquez, V E; Cooney, D A; Monks, A; Scudiero, D; Krohn, K; Jayaram, H N

    1994-03-15

    Benzamide riboside exhibits significant cytotoxicity against a variety of human tumor cells in culture. On the basis of metabolic studies, the primary target of this drug's action appears to be IMP dehydrogenase (IMPDH). Incubation of human myelogenous leukemia K562 cells with an IC50 concentration of benzamide riboside resulted in an expansion of IMP pools (5.9-fold), with a parallel reduction in the concentration of GMP (90%), GDP (63%), GTP (55%) and dGTP (40%). On kinetic grounds, it was deduced that benzamide riboside (whose Ki versus IMPDH is 6.4 mM, while that of its 5'-monophosphate is 3.9 mM) or its 5'-monophosphate were unlikely to be responsible for inhibition of this target enzyme, IMPDH, since only micromolar concentrations of benzamide riboside were needed to exert potent inhibition of tumor-cell growth. Studies on the metabolism of this C-nucleoside have revealed the presence of a new peak eluting in the nucleoside diphosphate area on HPLC. Treatment of this peak with venom phosphodiesterase degraded it and concurrently nullified its inhibitory activity versus IMPDH; alkaline phosphatase, on the other hand, totally failed to digest the anabolite. These results suggest that the metabolite in question is the phosphodiester, benzamide adenine dinucleotide (BAD). Evidence that the inhibitor was an analog of NAD, wherein the nicotinamide moiety has been replaced by benzamide, was provided by both NMR and mass spectrometric analysis and confirmed by enzymatic synthesis. Further insight into the nature of the active principle was obtained from kinetic studies, which established that BAD competitively inhibited NAD utilization by partially purified IMPDH from K562 cells with a Ki of 0.118 microM. In concert, these studies establish that benzamide riboside exhibits potent antiproliferative activity by inhibiting IMPDH through BAD. PMID:7907081

  8. Neural network with formed dynamics of activity

    SciTech Connect

    Dunin-Barkovskii, V.L.; Osovets, N.B.

    1995-03-01

    The problem of developing a neural network with a given pattern of the state sequence is considered. A neural network structure and an algorithm, of forming its bond matrix which lead to an approximate but robust solution of the problem are proposed and discussed. Limiting characteristics of the serviceability of the proposed structure are studied. Various methods of visualizing dynamic processes in a neural network are compared. Possible applications of the results obtained for interpretation of neurophysiological data and in neuroinformatics systems are discussed.

  9. Electrochemiluminescent Arrays for Cytochrome P450-Activated Genotoxicity Screening. DNA Damage from Benzo[a]pyrene Metabolites

    PubMed Central

    Hvastkovs, Eli G.; So, Minjeong; Krishnan, Sadagopan; Bajrami, Besnik; Tarun, Maricar; Jansson, Ingela; Schenkman, John B.; Rusling, James F.

    2007-01-01

    Arrays suitable for genotoxicity screening are reported that generate metabolites from cytochrome P450 enzymes (CYPs) in thin-film spots. Array spots containing DNA, various human cyt P450s, and electrochemiluminescence (ECL) generating metallopolymer [Ru(bpy)2PVP10]2+ were exposed to H2O2 to activate the enzymes. ECL from all spots was visualized simultaneously using a CCD camera. Using benzo[a]pyrene as a test substrate, enzyme activity for producing DNA damage in the arrays was found in the order CYP1B1 > CYP1A2 > CYP1A1 > CYP2E1 > myoglobin, the same as the order of their metabolic activity. Thus, these arrays estimate the relative propensity of different enzymes to produce genotoxic metabolites. This is the first demonstration of ECL arrays for high-throughput in vitro genotoxicity screening. PMID:17261025

  10. 3,4-DEHYDRODEBRISOQUINE, A NOVEL DEBRISOQUINE METABOLITE FORMED FROM 4-HYDROXYDEBRISOQUINE THAT IMPACTS THE CYP2D6 METABOLIC RATIO

    PubMed Central

    Zhen, Yueying; Slanař, Ondřej; Krausz, Kristopher W.; Chen, Chi; Slavík, Josef; McPhail, Kerry L.; Zabriskie, T. Mark; Perlík, František; Gonzalez, Frank J.; Idle, Jeffrey R.

    2006-01-01

    Considerable unexplained inter-subject variability in the debrisoquine metabolic ratio (urinary debrisoquine/4-hydroxydebrisoquine) exists within individual CYP2D6 genotypes. We speculated that debrisoquine was converted to as yet undisclosed metabolites. Thirteen healthy young volunteers, nine CYP2D6*1 homozygotes (EMs) and four CYP2D6*4 homozygotes (PMs) took 12.8 mg debrisoquine hemisulfate by mouth and collected 0–8 and 8–24 h urines, which were analyzed by GCMS before and after treatment with β-glucuronidase. Authentic 3,4-dehydrodebrisoquine was synthesized and characterized by GCMS, LC-MS/MS and 1H NMR. 3,4-Dehydrodebrisoquine is a novel metabolite of debrisoquine excreted variably in 0–24 h urine, both in EMs (3.1–27.6% dose) and PMs (0–2.1% dose). This metabolite is produced from 4-hydroxydebrisoquine in vitro by human and rat liver microsomes. A single CYP2D6*1 homozygote was administered 10.2 mg 4-hydroxydebrisoquine orally and also excreted 3,4-dehydrodebrisoquine. EMs excreted 6-hydroxydebrisoquine (0–4.8%), 8-hydroxydebrisoquine (0–1.3%) but these phenolic metabolites were not detected in PM urine. Debrisoquine and 4-hydroxydebrisoquine glucuronides were excreted in a highly genotype-dependent manner. A non-cytochrome P450 microsomal activity participates in the further metabolism of 4-hydroxydebrisoquine, which we speculate may also lead to the formation of 1- and 3-hydroxydebrisoquine and their ring-opened products. In conclusion, this study suggests that the traditional metabolic ratio is not a true measure of the debrisoquine 4-hydroxylation capacity of an individual and thus may, in part, explain the wide intragenotype variation in metabolic ratio. PMID:16782768

  11. 75 FR 26782 - Agency Information Collection Activities: Form I-864, Form I-864A, Form I-864EZ, and Form I-864W...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form I-864, Form I- 864A, Form I-864EZ, and Form I-864W; Extension of an Existing Information Collection; Comment Request ACTION: 60-Day Notice of Information Collection Under Review; Form I- 864, Affidavit of...

  12. [Secondary metabolites, lethality and antimicrobial activity of extracts from three corals and three marine mollusks from Sucre, Venezuela].

    PubMed

    Ordaz, Gabriel; D'Armas, Haydelba; Yáñez, Dayanis; Hernández, Juan; Camacho, Angel

    2010-06-01

    The study of biochemical activity of extracts obtained from marine organisms is gaining interest as some have proved to have efficient health or industrial applications. To evaluate lethality and antimicrobial activities, some chemical tests were performed on crude extracts of the octocorals Eunicea sp., Muricea sp. and Pseudopterogorgia acerosa and the mollusks Pteria colymbus, Phyllonotus pomum and Chicoreus brevifrons, collected in Venezuelan waters. The presence of secondary metabolites like alkaloids, unsaturated sterols and pentacyclic triterpenes in all invertebrates, was evidenced. Additionally, sesquiterpenlactones, saponins, tannins, cyanogenic and cardiotonic glycosides were also detected in some octocoral extracts, suggesting that biosynthesis of these metabolites is typical in this group. From the lethality bioassays, all extracts resulted lethal to Artemia salina (LC50<1000 microg/ml) with an increased of lethal activity with exposition time. P. pomum extract showed the highest lethality rate (LC50=46.8 microg/ml). Compared to the octocorals, mollusks extracts displayed more activity and a greater action spectrum against different bacterial strains, whereas octocorals also inhibited some fungi strains growth. Staphylococcus aureus was the most susceptible to the antimicrobial power of the extracts (66.7%), whereas Pseudomonas aeruginosa, Candida albicans and Aspergillus niger were not affected. The antibiosis shown by marine organisms extracts indicates that some of their biosynthesized metabolites are physiologically active, and may have possible cytotoxic potential or as a source of antibiotic components. PMID:20527468

  13. Direction of estradiol metabolism as a control of its hormonal action--uterotrophic activity of estradiol metabolites.

    PubMed

    Martucci, C; Fishman, J

    1977-12-01

    The uterotrophic activities of the catechol metabolites of estradiol 2-hydroxyestrone, 2-methoxyestrone and 2-hydroxyestradiol were measured under conditions of continuous administration of sc implanted paraffin pellets. The activity of these estrogens was compared to that of estradiol-17beta and its other principal metabolites estrone, estriol and 15alpha-hydroxyestriol (estetrol). The major catechol estrogens, 2-hydroxyestrone and 2-methoxyestrone, and the pregnancy metabolite, 15alpha-hydroxyestriol, exhibited no uterotrophic activity. The minor catecholestrogen, 2-hydroxyestradiol, showed some activity whose character was different from that exhibited by implants of estradiol, estrone and estriol all of which were equipotent uterotrophic agents. Implants of 2-hydroxyestrone in the presence of estradiol or estriol pellets did not diminish the response to the latter indicating that the 2-hydroxyestrone is not antiestrogenic under these conditions. It is concluded that the direction of estradiol metabolism can have a profound influence on the expression of peripheral hormonal activity with hydroxylation at C-2 terminating and hydroxylation at C-16 extending it. PMID:590186

  14. Silk microgels formed by proteolytic enzyme activity.

    PubMed

    Samal, Sangram K; Dash, Mamoni; Chiellini, Federica; Kaplan, David L; Chiellini, Emo

    2013-09-01

    The proteolytic enzyme α-chymotrypsin selectively cleaves the amorphous regions of silk fibroin protein (SFP) and allows the crystalline regions to self-assemble into silk microgels (SMGs) at physiological temperature. These microgels consist of lamellar crystals in the micrometer scale, in contrast to the nanometer-scaled crystals in native silkworm fibers. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zeta potential results demonstrated that α-chymotrypsin utilized only the non-amorphous domains or segments of the heavy chain of SFP to form negatively charged SMGs. The SMGs were characterized in terms of size, charge, structure, morphology, crystallinity, swelling kinetics, water content and thermal properties. The results suggest that the present technique of preparing SMGs by α-chymotrypsin is simple and efficient, and that the prepared SMGs have useful features for studies related to biomaterial and pharmaceutical needs. This process is also an easy way to obtain the amorphous peptide chains for further study. PMID:23756227

  15. CSF biomarkers of monocyte activation and chemotaxis correlate with magnetic resonance spectroscopy metabolites during chronic HIV disease.

    PubMed

    Anderson, Albert M; Fennema-Notestine, Christine; Umlauf, Anya; Taylor, Michael J; Clifford, David B; Marra, Christina M; Collier, Ann C; Gelman, Benjamin B; McArthur, Justin C; McCutchan, J Allen; Simpson, David M; Morgello, Susan; Grant, Igor; Letendre, Scott L

    2015-10-01

    Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) persist despite combination antiretroviral therapy (cART), supporting the need to better understand HIV neuropathogenesis. Magnetic resonance spectroscopy (MRS) of the brain has demonstrated abnormalities in HIV-infected individuals despite cART. We examined the associations between MRS metabolites and selected cerebrospinal fluid (CSF) biomarkers reflecting monocyte/macrophage activation and chemotaxis. A multicenter cross-sectional study involving five sites in the USA was conducted. The following CSF biomarkers were measured: soluble CD14 (sCD14), monocyte chemotactic protein-1 (MCP-1), interferon inducible protein 10 (IP-10), and stromal cell-derived growth factor 1 alpha (SDF-1α). The following MRS metabolites were measured from basal ganglia (BG), frontal white matter (FWM), and frontal gray matter (FGM): N-acetylaspartate (NAA), myo-inositol (MI), choline (Cho), and creatine (Cr). CSF biomarkers were compared to absolute MRS metabolites as well as metabolite/Cr ratios using linear regression. Eighty-three HIV-infected individuals were included, 78 % on cART and 37 % with HAND. The most robust positive correlations were between MCP-1 and Cho in BG (R (2) 0.179, p < 0.001) as well as MCP-1 and MI in FWM (R (2) 0.137, p = 0.002). Higher Cr levels in FWM were associated with MCP-1 (R (2) 0. 075, p = 0.01) and IP-10 (R (2) 0.106, p = 0.003). Comparing biomarkers to MRS metabolite/Cr ratios impacted some relationships, e.g., higher sCD14 levels were associated with lower Cho/Cr ratios in FGM (R (2) 0.224, p < 0.001), although higher MCP-1 levels remained associated with Cho/Cr in BG. These findings provide evidence that monocyte activation and chemotaxis continue to contribute to HIV-associated brain abnormalities in cART-treated individuals. PMID:26069183

  16. Activation of Dormant Secondary Metabolite Production by Introducing Neomycin Resistance into the Deep-Sea Fungus, Aspergillus versicolor ZBY-3

    PubMed Central

    Dong, Yuan; Cui, Cheng-Bin; Li, Chang-Wei; Hua, Wei; Wu, Chang-Jing; Zhu, Tian-Jiao; Gu, Qian-Qun

    2014-01-01

    A new ultrasound-mediated approach has been developed to introduce neomycin-resistance to activate silent pathways for secondary metabolite production in a bio-inactive, deep-sea fungus, Aspergillus versicolor ZBY-3. Upon treatment of the ZBY-3 spores with a high concentration of neomycin by proper ultrasound irradiation, a total of 30 mutants were obtained by single colony isolation. The acquired resistance of the mutants to neomycin was confirmed by a resistance test. In contrast to the ZBY-3 strain, the EtOAc extracts of 22 of the 30 mutants inhibited the human cancer K562 cells, indicating that these mutants acquired a capability to produce antitumor metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses of the EtOAc extracts of seven bioactive mutants and the ZBY-3 strain indicated that diverse secondary metabolites have been newly produced in the mutant extracts in contrast to the ZBY-3 extract. The followed isolation and characterization demonstrated that six metabolites, cyclo(d-Pro-d-Phe) (1), cyclo(d-Tyr-d-Pro) (2), phenethyl 5-oxo-l-prolinate (3), cyclo(l-Ile-l-Pro) (4), cyclo(l-Leu-l-Pro) (5) and 3β,5α,9α-trihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (6), were newly produced by the mutant u2n2h3-3 compared to the parent ZBY-3 strain. Compound 3 was a new compound; 2 was isolated from a natural source for the first time, and all of these compounds were also not yet found in the metabolites of other A. versicolor strains. Compounds 1–6 inhibited the K562 cells, with inhibition rates of 54.6% (1), 72.9% (2), 23.5% (3), 29.6% (4), 30.9% (5) and 51.1% (6) at 100 μg/mL, and inhibited also other human cancer HL-60, BGC-823 and HeLa cells, to some extent. The present study demonstrated the effectiveness of the ultrasound-mediated approach to activate silent metabolite production in fungi by introducing acquired resistance to aminoglycosides and its potential for discovering new compounds from silent

  17. Phenobarbital increases DNA adduct and metabolites formed by ochratoxin A: role of CYP 2C9 and microsomal glutathione-S-transferase.

    PubMed

    El Adlouni, C; Pinelli, E; Azémar, B; Zaoui, D; Beaune, P; Pfohl-Leszkowicz, A

    2000-01-01

    Ochratoxin A (OTA), a mycotoxin that induces nephrotoxicity and urinary tract tumors, is genotoxic and can be metabolized not only by different cytochromes P450 (CYP) but also by peroxidases involved in the arachidonic cascade, although the exact nature of the metabolites involved in the genotoxic process is still unknown. In order to establish the relation between OTA genotoxicity and the formation of metabolites, we chose three experimental models: kidney microsomes from rabbit, human bronchial epithelial cells, and microsomes from yeast that specifically express the human cytochrome P450 2C9 or 2B6 genes. OTA-DNA adducts were analyzed by (32)P postlabeling and the OTA derivatives formed were isolated by HPLC after incubation of OTA in the presence of: (1) kidney microsomes from rabbit pretreated or not with phenobarbital (PB); (2) human pulmonary epithelial cells simultaneously pretreated (or not) with PB alone or in the presence of ethacrynic acid (EA); (3) microsomes expressing CYP 2B6 and 2C9. PB pretreatment significantly increased DNA adducts formed after OTA treatment, both in the presence of kidney microsomes and bronchial epithelial cells, and induced the formation of new adducts. Ethacrynic acid, which inhibits microsomal glutathione-S-transferase, reduced DNA adduct level. DNA adducts were detected when OTA were incubated with microsomes expressing human CYP 2C9 but not with those expressing CYP 2B6. Several metabolites detected by HPLC were increased after PB treatment. Some of them could be related to DNA-adduct formation. In conclusion, OTA biotransformation, enhanced by PB pretreatment, increased DNA-adduct formation through pathways involving microsomal glutathion-S-transferase and CYP 2C9. PMID:10712746

  18. Species and gender differences in the formation of an active metabolite of a substituted 2,4-thiazolidinedione insulin sensitizer.

    PubMed

    Beconi, M; Mao, A; Creighton, M; Hop, C E C A; Chiu, S H L; Eydelloth, R; Franklin, R; Tang, F; Yu, N; Vincent, S

    2003-07-01

    1. The metabolism of a substituted 2,4-thiazolidinedione (P1) with dual PPARalpha/gamma activity was evaluated in male and female rats, dogs and monkeys. A para-hydroxylated metabolite (M1) with potent PPARgamma-selective agonist, was a major circulating drug-related component in female rats, dogs and monkeys, but not in male rats (M1-to-P1 exposure ratio of <1, 3-5, 5 and 5-11 in male rat, monkey, female rat, and dog, respectively). 2. M1 (%) formed in vitro (5, 53, 57-65, 67 and 67% in male rat, monkey, female rat, dog, and human liver microsomes, respectively), rank ordered with M1 (%) formed in vivo (24-45, 53-57, 78, 75-85%, for male rat, monkey, female rat and dog, respectively, after oral administration of P1). 3. The plasma clearance of M1 was higher in male rats (32 ml min(-1) kg(-1) compared with 6, 7 and 2 ml min(-1) kg(-1) in female rat, male monkey and male dogs, respectively). 4. The low amounts of M1 observed in male rats, with the appearance of products of the cleavage of the propyl group between the phenyl groups was probably due to the presence of the sex-specific CYP2C11, which cleaves P1 at the propyl bridge. None of the CYPs present in female rats cleaved P1 at this site and M1 was only produced by CYP2C6. In humans, only CYP2C8 and the polymorphic CYP2C19 produced M1. PMID:12893525

  19. Pre-systemic elimination of tilidine: localization and consequences for the formation of the active metabolite nortilidine.

    PubMed

    Eichbaum, Christine; Mathes, Kristin; Burhenne, Jürgen; Markert, Christoph; Blank, Antje; Mikus, Gerd

    2015-02-01

    The therapeutic activity of tilidine, an opioid analgesic, is mainly related to its active metabolite nortilidine. Nortilidine formation mainly occurs during the high intestinal first-pass metabolism of tilidine by N-demethylation. Elimination of the active nortilidine to the inactive bisnortilidine is also mediated by N-demethylation and is supposed to take place in the liver, probably at a smaller rate. The aim of this study was the investigation of the pre-systemic elimination of tilidine using grapefruit juice (GFJ) as an intestinal CYP3A4 inhibitor and efavirenz (EFV) as a CYP3A4 activator. A randomized, open, placebo-controlled, cross-over study was conducted in 12 healthy volunteers using 100 mg tilidine solution p.o., regular strength GFJ 250 mL (3 times at 12-hr intervals) and EFV 400 mg (12 hr before tilidine administration). Tilidine, nortilidine and bisnortilidine in plasma and urine were quantified by a validated LC/MS/MS analysis. GFJ did not change any pharmacokinetic parameter of tilidine and its metabolites, which suggests that intestinal CYP3A4 does not contribute to the first-pass metabolism of tilidine. No effect of EFV on the pharmacokinetics of the active nortilidine was observed except a significant reduction of the terminal elimination half-life by 15%. Overall elimination (renal and metabolic clearances) was unaffected by every treatment. CYP3A4 does not seem to play a major role in tilidine first-pass and overall metabolism. Other unknown metabolites and their enzymes responsible for their formation have to be investigated as they account for the majority of renally excreted metabolites. PMID:25223231

  20. 76 FR 61725 - Agency Information Collection Activities: Case Submission Form, Case Assistance Form; (Form DHS...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-05

    ... Federal Register on July 18, 2011 at 76 FR 42129, for a 60-day public comment period. No comments were... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND...-7001), Online Ombudsman Form DHS-7001 AGENCY: Office of the Citizenship and Immigration...

  1. Metabolite identification of seven active components of Huan-Nao-Yi-Cong-Fang in rat plasma using high-performance liquid chromatography combined with hybrid ion trap/time-of-flight mass spectrometry.

    PubMed

    Wang, Minchao; Lu, Yanzhen; Liu, Jiangang; Li, Hao; Wei, Yun

    2016-02-01

    Huan-Nao-Yi-Cong-Fang (HNYCF) is a potential prescription in treating Alzheimer's disease. Seven constituents [ferulic acid (FA), 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside (THSG), berberine hydrochloride (BHCl), emodin, ginsenoside Rg1 (Rg1), ginsenoside Re (Re) and ginsenoside Rb1 (Rb1)] have been used as quality chemical markers of HNYCF owing to their biological significance and high contents in crude plant materials. This study explored the metabolites of the seven bioactive components in rat plasma to give useful data for further study of the action mechanism of HNYCF. LC/MS-IT-TOF was used to simultaneously characterize the metabolites of the seven components. Using the combination of MetID Solution 1.0 software and accurate mass measurements, the metabolites of HNYCF were reliably characterized. Their structures were elucidated based on the accurate MS(2) spectra and comparisons of their changes in accurate molecular masses and fragment ions with those of parent compounds. A total of five parent active compounds (BHCl, emodin, Rg1, Rb1 and Re) and 10 metabolites were found from the rat plasma 2 h after oral administration of HNYCF dosage, of which two metabolites of emodin were observed for the first time. The proposed metabolic pathways of the bioactive components in the rat plasma are helpful for further studies on the pharmacokinetics and real active compound forms of this drug. PMID:26138785

  2. Population pharmacokinetic modeling of oxcarbazepine active metabolite in Chinese patients with epilepsy.

    PubMed

    Yu, Yunli; Zhang, Quanying; Xu, Wenjun; Lv, Chengzhe; Hao, Gang

    2016-08-01

    The aim of the study was to develop a population pharmacokinetic (PPK) model of oxcarbazepine and optimize the treatment of oxcarbazepine in Chinese patients with epilepsy. A total of 108 oxcarbazepine therapeutic drug monitoring samples from 78 patients with epilepsy were collected in this study. The pharmacologically active metabolite 10,11-dihydro-10-hydrocarbamazepine (MHD) was used as the analytical target for monitoring therapy of oxcarbazepine. Patients' clinical data were retrospectively collected. The PPK model for MHD was developed using Phoenix NLME 1.2 with a non-linear mixed-effect model. MHD pharmacokinetics obeys a one-compartment model with first-order absorption and elimination. The effect of age, gender, red blood cell count, red blood cell specific volume, hemoglobin (HGB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and serum creatine were analyzed. Bootstrap and data splitting were used simultaneously to validate the final PPK models. The mean values of volume of distribution and clearance of MHD in the patients were 14.2 L and 2.38 L h(-1), respectively. BUN and HGB influenced the MHD volume of distribution according to the following equation: V = tvV × (BUN/4.76)(-0.007) × (HGB/140)(-0.001) × e (ηV) . The MHD clearance was dependent on ALT and gender as follows: CL = tvCL × (ALT/30)(0.181) × (gender) × 1.083 × e (ηCL). The final PPK model was demonstrated to be suitable and effective and it can be used to evaluate the pharmacokinetic parameters of MHD in Chinese patients with epilepsy and to choose an optimal dosage regimen of oxcarbazepine on the basis of these parameters. PMID:25700977

  3. Antinociceptive activity of extracts and secondary metabolites from wild growing and micropropagated plants of Renealmia alpinia

    PubMed Central

    Gómez-Betancur, Isabel; Cortés, Natalie; Benjumea, Dora; Osorio, Edison; León, Francisco; Cutler, Stephen J.

    2015-01-01

    Ethnopharmacological relevance Renealmia alpinia is native to the American continent and can be found from Mexico to Brazil, and in the Caribbean islands. It is known as “matandrea” in Colombia, and it has been commonly used in traditional medicine to treat painful diseases and ailments. Based on its traditional uses, it is of interest to evaluate the pharmacologic effects of this plant and its secondary metabolites. Materials and methods Methanol and aqueous extracts of wild and micropropagated R. alpinia (leaves) were obtained and chemically compared by High Performance Thin Layer Chromatography (HPTLC). The antinociceptive activity of these extracts was examined using an in vivo assay (Siegmund test). Additionally, the dichloromethane extract of R. alpinia was fractionated and pure compounds were isolated by chromatographic methods. The structure elucidation of isolated compounds was performed by NMR experiments and spectroscopic techniques and comparison with the literature data. Purified compounds were evaluated for their in vitro binding affinity for opioids and cannabinoids receptors. Results The dichloromethane extract of the plant’s aerial part afforded sinostrobin (1), naringenin 7,4′-dimethyl ether (2), 2′,6′-dihydroxy-4′-methoxychalcone (3), 4-methoxy-6-(2-phenylethenyl)-2H-pyran-2-one (4), naringenin 7-methyl ether (5) and 3,5-heptanediol, 1,7-diphenyl (6), which were isolated using chromatographic methods. Their chemical structures were established by physical and spectroscopic techniques. The antinociceptive effects observed in mice by extracts of wild and micropropagated plants were similar. The compounds isolated from R. alpinia do not show affinity to opioid or cannabinoid receptors. Conclusion Aqueous and methanol extracts of R. alpinia provide antinociceptive and analgesic effects in an in vivo model. These results contribute additional insight as to why this plant is traditionally used for pain management. Also, this is the first

  4. Tissue accumulation kinetics of ciclesonide-active metabolite and budesonide in mice.

    PubMed

    Mårs, Ulla; d'Argy, Roland; Hallbeck, Karin; Miller-Larsson, Anna; Edsbäcker, Staffan

    2013-06-01

    Inhaled corticosteroids (ICS) are mainstay treatment of asthma and chronic obstructive pulmonary disease. However, highly lipophilic ICS accumulate in systemic tissues, which may lead to adverse systemic effects. The accumulation of a new, highly lipophilic ICS, ciclesonide and its active metabolite (des-CIC) has not yet been reported. Here, we have compared tissue accumulation of des-CIC and an ICS of a moderate lipophilicity, budesonide (BUD), after 14 days of once-daily treatment in mice. Single, three or 14 daily doses of [(3) H]-des-CIC or [(3) H]-BUD were administered subcutaneously to male CD1 albino mice, which were killed at 4 hr, 24 hr or 5 days after the last dose. Distribution of tissue concentration of radioactivity was studied by quantitative whole-body autoradiography. Pattern of radioactivity distribution across most tissues was similar for both corticosteroids after a single as well as after repeated dosing. However, tissue concentration of radioactivity differed between des-CIC and BUD. After a single dose, concentrations of radioactivity for both corticosteroids were low for most tissues but increased over 14 days of daily dosing. The tissue radioactivity of des-CIC at 24 hr and 5 days after the 14th dose was 2-3 times higher than that of BUD in majority of tissues. Tissue accumulation, assessed as concentration of tissue radioactivity 5 days after the 14th versus 3rd dose, showed an average ratio of 5.2 for des-CIC and 2.7 for BUD (p < 0.0001). In conclusion, des-CIC accumulated significantly more than BUD. Systemic accumulation may lead to increased risk of adverse systemic side effects during long-term therapy. PMID:23256845

  5. Pharmacokinetics, safety and tolerability of triflusal and its main active metabolite HTB in healthy Chinese subjects.

    PubMed

    Wang, M; Zhang, Q; Huang, M; Zong, S; Hua, W; Zhou, W

    2014-05-01

    Triflusal presents comparable antiplatelet activity to aspirin while presenting a more favourable safety profile, and is used in the treatment of thrombosis. The study aimed to evaluate the pharmacokinetics and safety of triflusal and its major metabolite 2-(hydroxyl)-4-(trifluoromethyl)- benzoic acid (HTB) in healthy Chinese subjects.30 healthy subjects were recruited in this randomized, single-center, and open-label, parallel, single ascending doses (300, 600, 900 mg) and multiple doses (600 mg, once daily for 7 days) study. Plasma samples were analyzed with a validated liquid chromatography tandem mass spectrometry (LC/MS/MS) method. Safety was assessed by adverse events, ECG, laboratory testing, and vital signs.Triflusal was safe and well tolerated. After single-dose administration, triflusal was rapidly absorbed with a mean Tmax of 0.55-0.92 h and a mean t1/2 kel of 0.35-0.65 h, HTB was absorbed with a mean Tmax of 2.35-3.03 h and a mean t1/2 kel of 52.5-65.57 h. Cmax and AUC for triflusal and HTB were approximately dose proportional over the 300-900 mg dose range. In the steady state, the accumulation index (R) indicated that the exposure of triflusal increased slightly with repeated dosing, and the exposure of HTB increased obviously. 3 adverse events certainly related to the investigational drugs occurred in the multiple-dose phase.Following oral dosing under fasting condition, triflusal is promptly absorbed and rapidly depleted from the systemic circulation. HTB is quickly generated from triflusal and slowly eliminated. Triflusal accumulates slightly in the body. HTB plasma concentration builds up progressively toward steady-state. PMID:24105106

  6. Antioxidative activity of bound-form phenolics in potato peel.

    PubMed

    Nara, Kazuhiro; Miyoshi, Takayuki; Honma, Tamaki; Koga, Hidenori

    2006-06-01

    Free and bound-form phenolics were isolated from potato (cv. Toyoshiro) flesh and peel. The free and bound-form phenolics in the peel showed high DPPH radical scavenging activity, while those in the flesh showed low activity. The total amount of chlorogenic acid and caffeic acid in the free-form phenolics from the peel was highly correlated with the DPPH radical scavenging activity. Ferulic acid was identified as the active radical scavenging compound in the bound-form phenolics from the peel. The potato peel may therefore offer an effective source of an antioxidative. PMID:16794331

  7. Trace Amine-Associated Receptor 1 (TAAR1) is Activated by Amiodarone Metabolites

    PubMed Central

    Snead, Aaron N.; Miyakawa, Motonori; Tan, Edwin S.; Scanlan, Thomas S.

    2012-01-01

    Amiodarone (Cordarone, Wyeth-Ayerst Pharmaceuticals) is a clinically available drug used to treat a wide variety of cardiac arrhythmias. We report here the synthesis and characterization of a panel of potential amiodarone metabolites that have significant structural similarity to thyroid hormone and its metabolites the iodothyronamines. Several of these amiodarone derivatives act as specific agonists of the G protein-coupled receptor (GPCR) trace amine-associated receptor 1 (TAAR1). This result demonstrates a novel molecular target for amiodarone derivatives with potential clinical significance. PMID:18752950

  8. [Detection of fungal metabolites showing toxic activity through Artemia salina bioassay].

    PubMed

    González, Ana María; Presa, Maximiliano; Latorre, María Gabriela; Lurá, María Cristina

    2007-03-01

    The aim of this study was to detect toxic metabolites from fungi contaminating food and medicinal herbs by applying the toxicity assay to Artemia salina. According to toxicity percentages, the extracts were classified as nontoxic (NT), slightly toxic (ST), toxic (T) and highly toxic (HT). Those classified as T and HT were assayed for mycotoxins. Only 6 out of 71 strains were found to be T (8.5%) for A. salina. Penicillium brevicompactum Dierckx, isolated from sausages, was found to be HT, mainly due to the presence of ochratoxin A and two other unidentified metabolites. PMID:17592895

  9. 76 FR 41279 - Agency Information Collection Activities; Form I-864, Form I-864A, Form I-864EZ, and Form I-864W...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ... was previously published in the Federal Register on May 4, 2011, at 76 FR 25364, allowing for a 60-day... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities; Form I-864, Form I- 864A, Form I-864EZ, and Form I-864W; Extension of an Existing Information Collection;...

  10. 75 FR 51093 - Agency Information Collection Activities: Form I-864, Form I-864A, Form I-864EZ, and Form I-864W...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... on May 12, 2010, at 75 FR 26782, allowing for a 60-day public comment period. USCIS received 2... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form I-864, Form I- 864A, Form I-864EZ, and Form I-864W; Extension of a Currently Approved Information...

  11. Non-targeted Metabolite Profiling and Scavenging Activity Unveil the Nutraceutical Potential of Psyllium (Plantago ovata Forsk).

    PubMed

    Patel, Manish K; Mishra, Avinash; Jha, Bhavanath

    2016-01-01

    Non-targeted metabolomics implies that psyllium (Plantago ovata) is a rich source of natural antioxidants, PUFAs (ω-3 and ω-6 fatty acids) and essential and sulfur-rich amino acids, as recommended by the FAO for human health. Psyllium contains phenolics and flavonoids that possess reducing capacity and reactive oxygen species (ROS) scavenging activities. In leaves, seeds, and husks, about 76, 78, 58% polyunsaturated, 21, 15, 20% saturated, and 3, 7, 22% monounsaturated fatty acids were found, respectively. A range of FAs (C12 to C24) was detected in psyllium and among different plant parts, a high content of the nutritive indicators ω-3 alpha-linolenic acid CPS (57%) and ω-6 linoleic acid CPS (18%) was detected in leaves. Similarly, total content of phenolics and the essential amino acid valine were also detected utmost in leaves followed by sulfur-rich amino acids and flavonoids. In total, 36 different metabolites were identified in psyllium, out of which 26 (13 each) metabolites were detected in leaves and seeds, whereas the remaining 10 were found in the husk. Most of the metabolites are natural antioxidants, phenolics, flavonoids, or alkaloids and can be used as nutrient supplements. Moreover, these metabolites have been reported to have several pharmaceutical applications, including anti-cancer activity. Natural plant ROS scavengers, saponins, were also detected. Based on metabolomic data, the probable presence of a flavonoid biosynthesis pathway was inferred, which provides useful insight for metabolic engineering in the future. Non-targeted metabolomics, antioxidants and scavenging activities reveal the nutraceutical potential of the plant and also suggest that psyllium leaves can be used as a green salad as a dietary supplement to daily food. PMID:27092153

  12. Non-targeted Metabolite Profiling and Scavenging Activity Unveil the Nutraceutical Potential of Psyllium (Plantago ovata Forsk)

    PubMed Central

    Patel, Manish K.; Mishra, Avinash; Jha, Bhavanath

    2016-01-01

    Non-targeted metabolomics implies that psyllium (Plantago ovata) is a rich source of natural antioxidants, PUFAs (ω-3 and ω-6 fatty acids) and essential and sulfur-rich amino acids, as recommended by the FAO for human health. Psyllium contains phenolics and flavonoids that possess reducing capacity and reactive oxygen species (ROS) scavenging activities. In leaves, seeds, and husks, about 76, 78, 58% polyunsaturated, 21, 15, 20% saturated, and 3, 7, 22% monounsaturated fatty acids were found, respectively. A range of FAs (C12 to C24) was detected in psyllium and among different plant parts, a high content of the nutritive indicators ω-3 alpha-linolenic acid (57%) and ω-6 linoleic acid (18%) was detected in leaves. Similarly, total content of phenolics and the essential amino acid valine were also detected utmost in leaves followed by sulfur-rich amino acids and flavonoids. In total, 36 different metabolites were identified in psyllium, out of which 26 (13 each) metabolites were detected in leaves and seeds, whereas the remaining 10 were found in the husk. Most of the metabolites are natural antioxidants, phenolics, flavonoids, or alkaloids and can be used as nutrient supplements. Moreover, these metabolites have been reported to have several pharmaceutical applications, including anti-cancer activity. Natural plant ROS scavengers, saponins, were also detected. Based on metabolomic data, the probable presence of a flavonoid biosynthesis pathway was inferred, which provides useful insight for metabolic engineering in the future. Non-targeted metabolomics, antioxidants and scavenging activities reveal the nutraceutical potential of the plant and also suggest that psyllium leaves can be used as a green salad as a dietary supplement to daily food. PMID:27092153

  13. Cellular Metabolic Activity and the Oxygen and Hydrogen Stable Isotope Composition of Intracellular Water and Metabolites

    NASA Astrophysics Data System (ADS)

    Kreuzer-Martin, H. W.; Hegg, E. L.

    2008-12-01

    biomass of Bacillus subtilis, a Gram-positive bacterium, showed the same pattern. Rapidly-dividing cells derived fewer of their O and H atoms from environmental water than did more slowly-growing cells and spores. To test whether a eukaryotic cell, surrounded by only a membrane, would also maintain an isotopic gradient and a detectable percentage of metabolic water, we applied our approach to cultured rat fibroblasts. Preliminary results showed that approximately 50% of the O and H atoms in exponentially growing cells were derived from metabolic activity. In quiescent cells, metabolic activity generated approximately 25% of the O and H atoms in intracellular water. Thus far, the data we have obtained is consistent with the following model: (1) Intracellular water is composed of water that diffuses in from the extracellular environment and water that is created as a result of metabolic activity. (2) The relative amounts of environmental and metabolic water inside a cell are a function of the cell's metabolic activity. (3) The oxygen and hydrogen isotope ratios of cellular metabolites are a function of those of intracellular water, and therefore reflect the metabolic activity of the cell at the time of biosynthesis.

  14. Integrated circuit-based electrochemical sensor for spatially resolved detection of redox-active metabolites in biofilms

    PubMed Central

    Bellin, Daniel L.; Sakhtah, Hassan; Rosenstein, Jacob K.; Levine, Peter M.; Thimot, Jordan; Emmett, Kevin; Dietrich, Lars E. P.; Shepard, Kenneth L.

    2014-01-01

    Despite advances in monitoring spatiotemporal expression patterns of genes and proteins with fluorescent probes, direct detection of metabolites and small molecules remains challenging. A technique for spatially resolved detection of small molecules would benefit the study of redox-active metabolites produced by microbial biofilms, which can drastically affect colony development. Here we present an integrated circuit-based electrochemical sensing platform featuring an array of working electrodes and parallel potentiostat channels. “Images” over a 3.25 × 0.9 mm area can be captured with a diffusion-limited spatial resolution of 750 μm. We demonstrate that square wave voltammetry can be used to detect, identify, and quantify (for concentrations as low as 2.6 μM) four distinct redox-active metabolites called phenazines. We characterize phenazine production in both wild-type and mutant Pseudomonas aeruginosa PA14 colony biofilms, and find correlations with fluorescent reporter imaging of phenazine biosynthetic gene expression. PMID:24510163

  15. Metabolites from Aspergillus fumigatus, an endophytic fungus associated with Melia azedarach, and their antifungal, antifeedant, and toxic activities.

    PubMed

    Li, Xiao-Jun; Zhang, Qiang; Zhang, An-Ling; Gao, Jin-Ming

    2012-04-01

    Thirty-nine fungal metabolites 1-39, including two new alkaloids, 12β-hydroxy-13α-methoxyverruculogen TR-2 (6) and 3-hydroxyfumiquinazoline A (16), were isolated from the fermentation broth of Aspergillus fumigatus LN-4, an endophytic fungus isolated from the stem bark of Melia azedarach. Their structures were elucidated on the basis of detailed spectroscopic analysis (mass spectrometry and one- and two-dimensional NMR experiments) and by comparison of their NMR data with those reported in the literature. These isolated compounds were evaluated for in vitro antifungal activities against some phytopathogenic fungi, toxicity against brine shrimps, and antifeedant activities against armyworm larvae (Mythimna separata Walker). Among them, sixteen compounds showed potent antifungal activities against phytopathogenic fungi (Botrytis cinerea, Alternaria solani, Alternaria alternata, Colletotrichum gloeosporioides, Fusarium solani, Fusarium oxysporum f. sp. niveum, Fusarium oxysporum f. sp. vasinfectum, and Gibberella saubinettii), and four of them, 12β-hydroxy-13α-methoxyverruculogen TR-2 (6), fumitremorgin B (7), verruculogen (8), and helvolic acid (39), exhibited antifungal activities with MIC values of 6.25-50 μg/mL, which were comparable to the two positive controls carbendazim and hymexazol. In addition, of eighteen that exerted moderate lethality toward brine shrimps, compounds 7 and 8 both showed significant toxicities with median lethal concentration (LC(50)) values of 13.6 and 15.8 μg/mL, respectively. Furthermore, among nine metabolites that were found to possess antifeedant activity against armyworm larvae, compounds 7 and 8 gave the best activity with antifeedant indexes (AFI) of 50.0% and 55.0%, respectively. Structure-activity relationships of the metabolites were also discussed. PMID:22409377

  16. Formation and anti-tumor activity of uncommon in vitro and in vivo metabolites of CPI-613, a novel anti-tumor compound that selectively alters tumor energy metabolism.

    PubMed

    Lee, King C; Shorr, Robert; Rodriguez, Robert; Maturo, Claudia; Boteju, Lakmal W; Sheldon, Adrian

    2011-08-01

    CPI-613 is a novel anti-tumor compound with a mechanism-of-action which appears distinct from the current classes of anti-cancer agents used in the clinic. CPI-613 demonstrates both in vitro and in vivo anti-tumor activity. In vitro metabolic studies using liver S9 were performed which demonstrated that CPI-613 undergoes both phase 1 (oxidation) and phase 2 (glucuronidation) transformations. Its metabolic half-life varied between species and ranged from 8 minutes (Hanford minipig) to 47 minutes (CD-1 mouse). We performed metabolite mass assessments using selected in vitro incubation samples and demonstrated that +16 amu oxidation with and without +176 amu glucuronidation products were generated by human and animal liver S9. LC/MS/MS fragmentation patterns showed that an uncommon sulfoxide metabolite was formed and the O-glucuronidation occurred at the terminal carboxyl moiety. We observed that the +192 amu sulfoxide/glucuronide was generated only in human liver S9 and not by any of the other species tested. Synthetic metabolites were prepared and compared with the enzymatically-generated metabolites. Both the chromatographic retention times and the LC/MS/MS fragmentation patterns were similar, demonstrating that the synthetic metabolites were virtually identical to the S9-generated products. CYP450 reaction phenotyping and inhibition data both suggested that multiple CYP isozymes (2C8 and 3A4, along with minor contributions by 2C9 and 2C19) were involved in CPI-613 metabolism and sulfoxide formation. Plasma samples from human subjects dosed with CPI-613 also contained the sulfoxide ± glucuronide metabolites. These results show that the in vitro- and in vivo-generated phase 1 and phase 2 metabolites were in good agreement. PMID:21722089

  17. Relation between clopidogrel active metabolite levels and different platelet aggregation methods in patients receiving clopidogrel and aspirin.

    PubMed

    Liang, Yan; Johnston, Marilyn; Hirsh, Jack; Pare, Guillaume; Li, Chunjian; Mehta, Shamir; Teo, Koon K; Sloane, Debi; Yi, Qilong; Zhu, Jun; Eikelboom, John W

    2012-11-01

    Clopidogrel is a prodrug that undergoes bioconversion via cytochrome P450 system to form an active metabolite (AM) that binds to the platelet ADP receptor. The antiplatelet effect of clopidogrel is commonly assessed by measuring the aggregatory response to 5 μM ADP by light transmission aggregation (LTA) or multiple electrode aggregometry (MEA) or by the vasodilator-stimulated phosphoprotein platelet reactivity index (VASP-PRI). To determine which of these three tests of platelet ADP receptor pathway inhibition most closely correlates with clopidogrel AM levels. We analyzed blood samples from 82 patients with coronary artery disease who were randomized to receive double-dose or standard dose clopidogrel for 2 weeks. We measured peak clopidogrel AM levels, platelet aggregation in response to ADP and VASP-PRI on days 1, and repeated all the measures on days 7 and 14. Linear regression analysis was used to examine the correlation between clopidogrel AM and LTA, MEA and VASP-PRI. Bland-Altman plots were used to explore the agreement between tests of the antiplatelet effects of clopidogrel. Clopidogrel AM on day 1 correlated most closely with VASP-PRI (r = -0.5767) and demonstrated weaker correlations with LTA (r = -0.4656) and MEA (r = -0.3384) (all p < 0.01). Intra-class correlation (ICC) between VASP-PRI and LTA was 0.6446; VASP-PRI and MEA was 0.4720; and LTA and MEA was 0.4693. Similar results were obtained on days 7 and 14. Commonly used pharmacodynamic measures of clopidogrel response are only moderately correlated with clopidogrel AM levels and may not be suitable to measure the adequacy of clopidogrel therapy. PMID:22797934

  18. Solving the Jigsaw Puzzle of Wound-Healing Potato Cultivars: Metabolite Profiling and Antioxidant Activity of Polar Extracts

    PubMed Central

    2015-01-01

    Potato (Solanum tuberosum L.) is a worldwide food staple, but substantial waste accompanies the cultivation of this crop due to wounding of the outer skin and subsequent unfavorable healing conditions. Motivated by both economic and nutritional considerations, this metabolite profiling study aims to improve understanding of closing layer and wound periderm formation and guide the development of new methods to ensure faster and more complete healing after skin breakage. The polar metabolites of wound-healing tissues from four potato cultivars with differing patterns of tuber skin russeting (Norkotah Russet, Atlantic, Chipeta, and Yukon Gold) were analyzed at three and seven days after wounding, during suberized closing layer formation and nascent wound periderm development, respectively. The polar extracts were assessed using LC-MS and NMR spectroscopic methods, including multivariate analysis and tentative identification of 22 of the 24 biomarkers that discriminate among the cultivars at a given wound-healing time point or between developmental stages. Differences among the metabolites that could be identified from NMR- and MS-derived biomarkers highlight the strengths and limitations of each method, also demonstrating the complementarity of these approaches in terms of assembling a complete molecular picture of the tissue extracts. Both methods revealed that differences among the cultivar metabolite profiles diminish as healing proceeds during the period following wounding. The biomarkers included polyphenolic amines, flavonoid glycosides, phenolic acids and glycoalkaloids. Because wound healing is associated with oxidative stress, the free radical scavenging activities of the extracts from different cultivars were measured at each wounding time point, revealing significantly higher scavenging activity of the Yukon Gold periderm especially after 7 days of wounding. PMID:24998264

  19. Pu-238 fuel form activities, January 1-31, 1983

    SciTech Connect

    Not Available

    1983-03-01

    This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  20. Pu-238 fuel form activities, January 1-31, 1981

    SciTech Connect

    Not Available

    1981-02-01

    This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  1. Pu-238 fuel form activities, January 1-31, 1982

    SciTech Connect

    Not Available

    1982-03-01

    This monthly report for /sup 238/Pu fuel form activities has two main sections: SRP-PuFF facility and SRL fuel form activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  2. Active Oxygen Metabolites and Thromboxane in Phorbol Myristate Acetate Toxicity to the Isolated, Perfused Rat Lung.

    NASA Astrophysics Data System (ADS)

    Carpenter, Laurie Jean

    When administered intravenously or intratracheally to rats, rabbits and sheep, phorbol myristate acetate (PMA) produces changes in lung morphology and function are similar to those seen in humans with the adult respiratory distress syndrome (ARDS). Therefore, it is thought that information about the mechanism of ARDS development can be gained from experiments using PMA-treated animals. Currently, the mechanisms by which PMA causes pneumotoxicity are unknown. Results from other studies in rabbits and in isolated, perfused rabbit lungs suggest that PMA-induced lung injury is mediated by active oxygen species from neutrophils (PMN), whereas studies in sheep and rats suggest that PMN are not required for the toxic response. The role of PMN, active oxygen metabolites and thromboxane (TxA_2) in PMA-induced injury to isolated, perfused rat lungs (IPLs) was examined in this thesis. To determine whether PMN were required for PMA to produce toxicity to the IPL, lungs were perfused for 30 min with buffer containing various concentrations of PMA (in the presence or absence of PMN). When concentrations >=q57 ng/ml were added to medium devoid of added PMN, perfusion pressure and lung weight increased. When a concentration of PMA (14-28 ng/ml) that did not by itself cause lungs to accumulate fluid was added to the perfusion medium containing PMN (1 x 10 ^8), perfusion pressure increased, and lungs accumulated fluid. These results indicate that high concentrations of PMA produce lung injury which is independent of PMN, whereas injury induced by lower concentrations is PMN-dependent. To examine whether active oxygen species were involved in mediating lung injury induced by PMA and PMN, lungs were coperfused with the oxygen radical scavengers SOD and/or catalase. Coperfusion with either or both of these enzymes totally protected lungs against injury caused by PMN and PMA. These results suggest that active oxygen species (the hydroxyl radical in particular), mediate lung injury in

  3. Fungal metabolite ophiobolin A as a promising anti-glioma agent: In vivo evaluation, structure-activity relationship and unique pyrrolylation of primary amines.

    PubMed

    Dasari, Ramesh; Masi, Marco; Lisy, Romana; Ferdérin, Marlène; English, Lance R; Cimmino, Alessio; Mathieu, Véronique; Brenner, Andrew J; Kuhn, John G; Whitten, Steven T; Evidente, Antonio; Kiss, Robert; Kornienko, Alexander

    2015-10-15

    Glioblastoma, the most common form of malignant primary brain tumor, is characterized by resistance to apoptosis, which is largely responsible for the low effectiveness of the classical chemotherapeutic approaches based on apoptosis induction in cancer cells. Previously, a fungal secondary metabolite ophiobolin A was found to have significant activity against apoptosis-resistant glioblastoma cells through the induction of a non-apoptotic cell death, thus, offering an innovative strategy to combat this type of cancer. The current work describes the results of a preliminary evaluation of ophiobolin A in an in vivo glioblastoma model and its chemical derivatization to establish first synthetically generated structure-activity relationship. The synthetic work has also led to the discovery of a unique reaction of ophiobolin A with primary amines suggesting the possibility of pyrrolylation of lysine residues on its intracellular target protein(s). PMID:26341136

  4. Tissue distribution study of columbianadin and its active metabolite columbianetin in rats.

    PubMed

    Zhang, You-Bo; Yang, Xiu-Wei

    2016-02-01

    Columbianadin, one of the main bioactive constituents of the roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan, has been found to possess obvious pharmacological effects in previous studies. In this study, a valid and sensitive reverse-phase high-performance liquid chromatography (RP-HPLC) method was established and validated for the determination of columbianadin (CBN) and its active metabolite columbianetin (CBT) in rat tissue samples. Sample separation was performed on an RP-HPLC column using a mobile phase of MeOH-H2 O (75:25, v/v) at a flow rate of 1.0 mL/min. The UV absorbance of the samples was measured at the wavelength 325 nm. The calibration curves for CBN were linear over the ranges of 0.5-20 µg/g for brain, testes and muscle, 1.0-10.0 µg/g for stomach and intestine, and 0.2-20.0 µg/g for heart, liver, spleen, lung and kidney. The calibration curves for CBT were linear over the ranges of 0.5-25 µg/g for stomach and intestine, and 0.1-10.0 µg/g for heart, liver, spleen, lung and kidney. The analysis method was successfully applied to a tissue distribution study of CBN and CBT after intravenous administration of CBN to rats. The results of this study indicated that CBN could be detected in all of the selected tissues after i.v. administration. CBN was distributed to rat tissues rapidly and could be metabolized to CBT in most detected tissues. Of the detected tissues, heart had the highest uptake of CBN, which suggested that heart might be one of the main target tissues of CBN. Concentrations of CBT were obviously higher in the digestive system than in other assayed tissues. The information provided by this research is very useful for gaining knowledge of the capacities of CBN and CBT to access different tissues. PMID:26115176

  5. Peroxisome Proliferator-Activated Receptor Activation is Associated with Altered Plasma One-Carbon Metabolites and B-Vitamin Status in Rats

    PubMed Central

    Lysne, Vegard; Strand, Elin; Svingen, Gard F. T.; Bjørndal, Bodil; Pedersen, Eva R.; Midttun, Øivind; Olsen, Thomas; Ueland, Per M.; Berge, Rolf K.; Nygård, Ottar

    2016-01-01

    Plasma concentrations of metabolites along the choline oxidation pathway have been linked to increased risk of major lifestyle diseases, and peroxisome proliferator-activated receptors (PPARs) have been suggested to be involved in the regulation of key enzymes along this pathway. In this study, we investigated the effect of PPAR activation on circulating and urinary one-carbon metabolites as well as markers of B-vitamin status. Male Wistar rats (n = 20) received for 50 weeks either a high-fat control diet or a high-fat diet with tetradecylthioacetic acid (TTA), a modified fatty acid and pan-PPAR agonist with high affinity towards PPARα. Hepatic gene expression of PPARα, PPARβ/δ and the enzymes involved in the choline oxidation pathway were analyzed and concentrations of metabolites were analyzed in plasma and urine. TTA treatment altered most biomarkers, and the largest effect sizes were observed for plasma concentrations of dimethylglycine, nicotinamide, methylnicotinamide, methylmalonic acid and pyridoxal, which were all higher in the TTA group (all p < 0.01). Hepatic Pparα mRNA was increased after TTA treatment, but genes of the choline oxidation pathway were not affected. Long-term TTA treatment was associated with pronounced alterations on the plasma and urinary concentrations of metabolites related to one-carbon metabolism and B-vitamin status in rats. PMID:26742069

  6. Peroxisome Proliferator-Activated Receptor Activation is Associated with Altered Plasma One-Carbon Metabolites and B-Vitamin Status in Rats.

    PubMed

    Lysne, Vegard; Strand, Elin; Svingen, Gard F T; Bjørndal, Bodil; Pedersen, Eva R; Midttun, Øivind; Olsen, Thomas; Ueland, Per M; Berge, Rolf K; Nygård, Ottar

    2016-01-01

    Plasma concentrations of metabolites along the choline oxidation pathway have been linked to increased risk of major lifestyle diseases, and peroxisome proliferator-activated receptors (PPARs) have been suggested to be involved in the regulation of key enzymes along this pathway. In this study, we investigated the effect of PPAR activation on circulating and urinary one-carbon metabolites as well as markers of B-vitamin status. Male Wistar rats (n = 20) received for 50 weeks either a high-fat control diet or a high-fat diet with tetradecylthioacetic acid (TTA), a modified fatty acid and pan-PPAR agonist with high affinity towards PPARα. Hepatic gene expression of PPARα, PPARβ/δ and the enzymes involved in the choline oxidation pathway were analyzed and concentrations of metabolites were analyzed in plasma and urine. TTA treatment altered most biomarkers, and the largest effect sizes were observed for plasma concentrations of dimethylglycine, nicotinamide, methylnicotinamide, methylmalonic acid and pyridoxal, which were all higher in the TTA group (all p < 0.01). Hepatic Pparα mRNA was increased after TTA treatment, but genes of the choline oxidation pathway were not affected. Long-term TTA treatment was associated with pronounced alterations on the plasma and urinary concentrations of metabolites related to one-carbon metabolism and B-vitamin status in rats. PMID:26742069

  7. Characterisation of metabolites of the putative cancer chemopreventive agent quercetin and their effect on cyclo-oxygenase activity

    PubMed Central

    Jones, D J L; Lamb, J H; Verschoyle, R D; Howells, L M; Butterworth, M; Lim, C K; Ferry, D; Farmer, P B; Gescher, A J

    2004-01-01

    Quercetin (3,5,7,3′,4′-pentahydroxyflavone) is a flavone with putative ability to prevent cancer and cardiovascular diseases. Its metabolism was evaluated in rats and human. Rats received quercetin via the intravenous (i.v.) route and metabolites were isolated from the plasma, urine and bile. Analysis was by high-performance liquid chromatography and confirmation of species identity was achieved by mass spectrometry. Quercetin and isorhamnetin, the 3′-O-methyl analogue, were found in both the plasma and urine. In addition, several polar peaks were characterised as sulphated and glucuronidated conjugates of quercetin and isorhamnetin. Extension of the metabolism studies to a cancer patient who had received quercetin as an i.v. bolus showed that (Quercetin removed) isorhamnetin and quercetin 3′-O-sulphate were major plasma metabolites. As a catechol, quercetin can potentially be converted to a quinone and subsequently conjugated with glutathione (GSH). Oxidation of quercetin with mushroom tyrosinase in the presence of GSH furnished GSH conjugates of quercetin, two mono- and one bis-substituted conjugates. However, these species were not found in biomatrices in rats treated with quercetin. As cyclo-oxygenase-2 (COX-2) expression is mechanistically linked to carcinogenesis, we examined whether quercetin and its metabolites can inhibit COX-2 in a human colorectal cancer cell line (HCA-7). Isorhamnetin and its 4′-isomer tamarixetin were potent inhibitors, reflected in a 90% decrease in prostaglandin E-2 (PGE-2) levels, a marker of COX-2 activity. Quercetin was less effective, with a 50% decline. Quercetin 3- and 7-O-sulphate had no effect on PGE-2. The results indicate that quercetin may exert its pharmacological effects, at least in part, via its metabolites. PMID:15292928

  8. Mass Spectrometric Characterization of Human Serum Albumin Adducts Formed with N-Oxidized Metabolites of 2-Amino-1-methyl-phenylimidazo[4,5-b]pyridine in Human Plasma and Hepatocytes

    PubMed Central

    Wang, Yi; Peng, Lijuan; Bellamri, Medjda; Langoueët, Sophie; Turesky, Robert J.

    2015-01-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic heterocyclic aromatic amine formed in cooked meats, is metabolically activated to electrophilic intermediates that form covalent adducts with DNA and protein. We previously identified an adduct of PhIP formed at the Cys34 residue of human serum albumin following reaction of albumin with the genotoxic metabolite 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (HONH-PhIP). The major adducted peptide recovered from a tryptic/chymotryptic digest was identified as the missed-cleavage peptide LQQC*[SO2PhIP]PFEDHVK, a [Cysteine-S-yl-PhIP]-S-dioxide linked adduct. In this investigation, we have characterized the albumin adduction products of N-sulfooxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-sulfooxy-PhIP), which is thought to be a major genotoxic metabolite of PhIP formed in vivo. Targeted and data-dependent scanning methods showed that N-sulfooxy-PhIP adducted to the Cys34 of albumin in human plasma to form LQQC*[SO2PhIP]PFEDHVK at levels that were 8 to 10-fold greater than the adduct levels formed with N-(acetyloxy)-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-acetoxy-PhIP) or HONH-PhIP. We also discovered that N-sulfooxy-PhIP forms an adduct at the sole tryptophan (Trp214) residue of albumin in the sequence AW*[PhIP]AVAR. However, stable adducts of PhIP with albumin were not detected in human hepatocytes. Instead, PhIP and 2-amino-1-methyl-6-(5-hydroxy)-phenylimidazo[4,5-b]pyridine (5-HO-PhIP), a solvolysis product of the proposed nitrenium ion of PhIP, were recovered during the proteolysis, suggesting a labile sulfenamide linkage had formed between an N-oxidized intermediate of PhIP and Cys34 of albumin. A stable adduct was formed at the Tyr411 residue of albumin in hepatocytes, and identified as a deaminated product of PhIP, Y*[desaminoPhIP]TK, where the 4-HO-tyrosine group bound to the C-2 imidazole atom of PhIP. PMID:25815793

  9. Mass Spectrometric Characterization of Human Serum Albumin Adducts Formed with N-Oxidized Metabolites of 2-Amino-1-methylphenylimidazo[4,5-b]pyridine in Human Plasma and Hepatocytes.

    PubMed

    Wang, Yi; Peng, Lijuan; Bellamri, Medjda; Langouët, Sophie; Turesky, Robert J

    2015-05-18

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic heterocyclic aromatic amine formed in cooked meats, is metabolically activated to electrophilic intermediates that form covalent adducts with DNA and protein. We previously identified an adduct of PhIP formed at the Cys(34) residue of human serum albumin following reaction of albumin with the genotoxic metabolite 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (HONH-PhIP). The major adducted peptide recovered from a tryptic/chymotryptic digest was identified as the missed-cleavage peptide LQQC*([SO2PhIP])PFEDHVK, a [cysteine-S-yl-PhIP]-S-dioxide linked adduct. In this investigation, we have characterized the albumin adduction products of N-sulfooxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-sulfooxy-PhIP), which is thought to be a major genotoxic metabolite of PhIP formed in vivo. Targeted and data-dependent scanning methods showed that N-sulfooxy-PhIP adducted to the Cys(34) of albumin in human plasma to form LQQC*([SO2PhIP])PFEDHVK at levels that were 8-10-fold greater than the adduct levels formed with N-(acetyloxy)-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-acetoxy-PhIP) or HONH-PhIP. We also discovered that N-sulfooxy-PhIP forms an adduct at the sole tryptophan (Trp(214)) residue of albumin in the sequence AW*([PhIP])AVAR. However, stable adducts of PhIP with albumin were not detected in human hepatocytes. Instead, PhIP and 2-amino-1-methyl-6-(5-hydroxy)phenylimidazo[4,5-b]pyridine (5-HO-PhIP), a solvolysis product of the proposed nitrenium ion of PhIP, were recovered during the proteolysis, suggesting a labile sulfenamide linkage had formed between an N-oxidized intermediate of PhIP and Cys(34) of albumin. A stable adduct was formed at the Tyr(411) residue of albumin in hepatocytes and identified as a deaminated product of PhIP, Y(*[desaminoPhIP])TK, where the 4-HO-tyrosine group bound to the C-2 imidazole atom of PhIP. PMID:25815793

  10. Reduced photoinhibition under low irradiance enhanced Kacip Fatimah (Labisia pumila Benth) secondary metabolites, phenyl alanine lyase and antioxidant activity.

    PubMed

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E

    2012-01-01

    A randomized complete block design experiment was designed to characterize the relationship between production of total flavonoids and phenolics, anthocyanin, photosynthesis, maximum efficiency of photosystem II (Fv/Fm), electron transfer rate (Fm/Fo), phenyl alanine lyase activity (PAL) and antioxidant (DPPH) in Labisia pumila var. alata, under four levels of irradiance (225, 500, 625 and 900 μmol/m(2)/s) for 16 weeks. As irradiance levels increased from 225 to 900 μmol/m(2)/s, the production of plant secondary metabolites (total flavonoids, phenolics and antocyanin) was found to decrease steadily. Production of total flavonoids and phenolics reached their peaks under 225 followed by 500, 625 and 900 μmol/m(2)/s irradiances. Significant positive correlation of production of total phenolics, flavonoids and antocyanin content with Fv/Fm, Fm/Fo and photosynthesis indicated up-regulation of carbon-based secondary metabolites (CBSM) under reduced photoinhibition on the under low light levels condition. At the lowest irradiance levels, Labisia pumila extracts also exhibited a significantly higher antioxidant activity (DPPH) than under high irradiance. The improved antioxidative activity under low light levels might be due to high availability of total flavonoids, phenolics and anthocyanin content in the plant extract. It was also found that an increase in the production of CBSM was due to high PAL activity under low light, probably signifying more availability of phenylalanine (Phe) under this condition. PMID:22754297

  11. Reduced Photoinhibition under Low Irradiance Enhanced Kacip Fatimah (Labisia pumila Benth) Secondary Metabolites, Phenyl Alanine Lyase and Antioxidant Activity

    PubMed Central

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z.E.

    2012-01-01

    A randomized complete block design experiment was designed to characterize the relationship between production of total flavonoids and phenolics, anthocyanin, photosynthesis, maximum efficiency of photosystem II (Fv/Fm), electron transfer rate (Fm/Fo), phenyl alanine lyase activity (PAL) and antioxidant (DPPH) in Labisia pumila var. alata, under four levels of irradiance (225, 500, 625 and 900 μmol/m2/s) for 16 weeks. As irradiance levels increased from 225 to 900 μmol/m2/s, the production of plant secondary metabolites (total flavonoids, phenolics and antocyanin) was found to decrease steadily. Production of total flavonoids and phenolics reached their peaks under 225 followed by 500, 625 and 900 μmol/m2/s irradiances. Significant positive correlation of production of total phenolics, flavonoids and antocyanin content with Fv/Fm, Fm/Fo and photosynthesis indicated up-regulation of carbon-based secondary metabolites (CBSM) under reduced photoinhibition on the under low light levels condition. At the lowest irradiance levels, Labisia pumila extracts also exhibited a significantly higher antioxidant activity (DPPH) than under high irradiance. The improved antioxidative activity under low light levels might be due to high availability of total flavonoids, phenolics and anthocyanin content in the plant extract. It was also found that an increase in the production of CBSM was due to high PAL activity under low light, probably signifying more availability of phenylalanine (Phe) under this condition. PMID:22754297

  12. Anti-onchocerca Metabolites from Cyperus articulatus: Isolation, In Vitro Activity and In Silico 'Drug-Likeness'.

    PubMed

    Metuge, Jonathan Alunge; Babiaka, Smith B; Mbah, James A; Ntie-Kang, Fidele; Ayimele, Godfred A; Cho-Ngwa, Fidelis

    2014-08-01

    The aims of this investigation were to isolate active ingredients from the roots/rhizomes of Cyperus articulatus used as herbal medicine in Cameroon for the treatment of human onchocerciasis and to assess the efficacy of the metabolites on the Onchocerca worm. The antifilarial activity was evaluated in vitro on microfilariae (Mfs) and adult worms of the bovine derived Onchocerca ochengi, a close relative of Onchocerca volvulus. Cytotoxicity was assessed in vitro on monkey kidney epithelial cells. The structures of the active compounds were determined using spectroscopic methods and their drug-likeness evaluated using Lipinski parameters. Two secondary metabolites, AMJ1 [containing mustakone (1) as the major component] and linoleic acid or (9Z,12Z)-octadeca-9,12-dienoic acid (2) were isolated. Both compounds were found to kill both the microfilariae and adult worms of O. ochengi in a dose dependent manner. The IC50s for AMJ1 were 15.7 µg/mL for Mfs, 17.4 µg/mL for adult males and 21.9 µg/mL for adult female worms while for linoleic acid the values were, 15.7 µg/mL for Mfs, 31.0 µg/mL for adult males and 44.2 µg/mL for adult females. The present report provides the first ever evidence of the anti-Onchocerca efficacy of AMJ1 and linoleic acid. Thus, these secondary metabolites may provide a lead for design and development of new antifilarial agents. PMID:25089243

  13. Effectiveness of clopidogrel dose escalation to normalize active metabolite exposure and antiplatelet effects in CYP2C19 poor metabolizers.

    PubMed

    Horenstein, Richard B; Madabushi, Rajnikanth; Zineh, Issam; Yerges-Armstrong, Laura M; Peer, Cody J; Schuck, Robert N; Figg, William Douglas; Shuldiner, Alan R; Pacanowski, Michael A

    2014-08-01

    Carriers of two copies of the loss-of-function CYP2C19*2 variant convert less clopidogrel into its active metabolite, resulting in diminished antiplatelet responses and higher cardiovascular event rates. To evaluate whether increasing the daily clopidogrel dose in poor metabolizers (PM) overcomes the effect of the CYP2C19 * 2 variant, we enrolled 18 healthy participants in a genotype-stratified, multi-dose, three-period, fixed-sequence crossover study. Six participants with the *1/*1 extensive (EM), *1/*2 intermediate (IM), and *2/*2 poor metabolizer genotypes each received 75 mg, 150 mg, and 300 mg each for 8 days. In each period, maximal platelet aggregation 4 hours post-dose (MPA4) and active metabolite area under the curve (AUC) differed among genotype groups (P < .05 for all). At day 8, PMs needed 300 mg daily and IMs needed 150 mg daily to attain a similar MPA4 as EMs on the 75 mg dose (32.6%, 33.2%, 31.3%, respectively). Similarly, PMs needed 300 mg daily to achieve active metabolite concentrations that were similar to EMs on 75 mg (AUC 37.7 and 33.5 ng h/mL, respectively). These results suggest that quadrupling the usual clopidogrel dose might be necessary to overcome the effect of poor CYP2C19 metabolism. PMID:24710841

  14. Multiple modes of inhibition of human cytochrome P450 2J2 by dronedarone, amiodarone and their active metabolites.

    PubMed

    Karkhanis, Aneesh; Lam, Hui Yuan; Venkatesan, Gopalakrishnan; Koh, Siew Kwan; Chai, Christina Li Lin; Zhou, Lei; Hong, Yanjun; Kojodjojo, Pipin; Chan, Eric Chun Yong

    2016-05-01

    Dronedarone, a multiple ion channel blocker is prescribed for the treatment of paroxysmal and persistent atrial fibrillation. While dronedarone does not precipitate toxicities like its predecessor amiodarone, its clinical use has been associated with idiosyncratic hepatic and cardiac adverse effects and drug-drug interactions (DDIs). As dronedarone is a potent mechanism-based inactivator of CYP3A4 and CYP3A5, a question arose if it exerts a similar inhibitory effect on CYP2J2, a prominent cardiac CYP450 enzyme. In this study, we demonstrated that CYP2J2 is reversibly inhibited by dronedarone (Ki=0.034μM), amiodarone (Ki=4.8μM) and their respective pharmacologically active metabolites namely N-desbutyldronedarone (NDBD) (Ki=0.55μM) and N-desethylamiodarone (NDEA) (Ki=7.4μM). Moreover, time-, concentration- and NADPH-dependent irreversible inactivation of CYP2J2 was investigated where inactivation kinetic parameters (KI, kinact) and partition ratio (r) of dronedarone (0.05μM, 0.034min(-1), 3.3), amiodarone (0.21μM, 0.015min(-1), 20.7) and NDBD (0.48μM, 0.024min(-1), 21.7) were observed except for NDEA. The absence of the characteristic Soret peak, lack of recovery of CYP2J2 activity upon dialysis, and biotransformation of dronedarone and NDBD to quinone-oxime reactive metabolites further confirmed the irreversible inactivation of CYP2J2 by dronedarone and NDBD is via the covalent adduction of CYP2J2. Our novel findings illuminate the possible mechanisms of DDIs and cardiac adverse effects due to both reversible inhibition and irreversible inactivation of CYP2J2 by dronedarone, amiodarone and their active metabolites. PMID:26972388

  15. In vivo anti-inflammatory activity of some naturally occurring O- and N-prenyl secondary metabolites.

    PubMed

    Epifano, Francesco; Genovese, Salvatore; Fiorito, Serena; della Loggia, Roberto; Tubaro, Aurelia; Sosa, Silvio

    2014-01-01

    A series of O- and N-prenyl secondary metabolites of insect, fungal, and plant origin have been evaluated for their topical anti-inflammatory activity using the Croton oil ear test in mice as a model of acute inflammation. Some of the tested compounds revealed an effect (ID50 = 0.31 divided by 0.56 micromol/cm2) comparable with that of the reference non-steroidal anti-inflammatory drug indomethacin (ID50 = 0.23 micromol/cm2). PMID:24660470

  16. Prostaglandin endoperoxide synthetase and the activation of benzo(a)pyrene to reactive metabolites in vivo in guinea pigs

    SciTech Connect

    Garattini, E.; Coccia, P.; Romano, M.; Jiritano, L.; Noseda, A.; Salmona, M.

    1984-11-01

    The role of prostaglandin endoperoxide synthetase in the in vivo activation of benzo(a)pyrene to reactive metabolites capable of interacting irreversibly with cellular macromolecules was studied in guinea pig liver, lung, kidney, spleen, small intestine, colon, and brain. DNA and protein covalent binding experiments were made after systemic administration of acetylsalicylic acid (200 mg/kg) followed by radiolabeled benzo(a)pyrene (4 microgram/kg). Results are compared with a control situation in which the prostaglandin endoperoxide synthetase inhibitor (acetylsalicylic acid) was not administered. No decrease in the level of DNA or protein benzo(a)pyrene-derived covalent binding was observed in any of the tissues studied.

  17. Transthyretin Binding Heterogeneity and Anti-amyloidogenic Activity of Natural Polyphenols and Their Metabolites.

    PubMed

    Florio, Paola; Folli, Claudia; Cianci, Michele; Del Rio, Daniele; Zanotti, Giuseppe; Berni, Rodolfo

    2015-12-11

    Transthyretin (TTR) is an amyloidogenic protein, the amyloidogenic potential of which is enhanced by a number of specific point mutations. The ability to inhibit TTR fibrillogenesis is known for several classes of compounds, including natural polyphenols, which protect the native state of TTR by specifically interacting with its thyroxine binding sites. Comparative analyses of the interaction and of the ability to protect the TTR native state for polyphenols, both stilbenoids and flavonoids, and some of their main metabolites have been carried out. A main finding of this investigation was the highly preferential binding of resveratrol and thyroxine, both characterized by negative binding cooperativity, to distinct sites in TTR, consistent with the data of x-ray analysis of TTR in complex with both ligands. Although revealing the ability of the two thyroxine binding sites of TTR to discriminate between different ligands, this feature has allowed us to evaluate the interactions of polyphenols with both resveratrol and thyroxine preferential binding sites, by using resveratrol and radiolabeled T4 as probes. Among flavonoids, genistein and apigenin were able to effectively displace resveratrol from its preferential binding site, whereas genistein also showed the ability to interact, albeit weakly, with the preferential thyroxine binding site. Several glucuronidated polyphenol metabolites did not exhibit significant competition for resveratrol and thyroxine preferential binding sites and lacked the ability to stabilize TTR. However, resveratrol-3-O-sulfate was able to significantly protect the protein native state. A rationale for the in vitro properties found for polyphenol metabolites was provided by x-ray analysis of their complexes with TTR. PMID:26468275

  18. Plant Polyphenols and Oxidative Metabolites of the Herbal Alkenylbenzene Methyleugenol Suppress Histone Deacetylase Activity in Human Colon Carcinoma Cells

    PubMed Central

    Groh, Isabel Anna Maria; Chen, Chen; Lüske, Claudia; Cartus, Alexander Thomas; Esselen, Melanie

    2013-01-01

    Evidence has been provided that diet and environmental factors directly influence epigenetic mechanisms associated with cancer development in humans. The inhibition of histone deacetylase (HDAC) activity and the disruption of the HDAC complex have been recognized as a potent strategy for cancer therapy and chemoprevention. In the present study, we investigated whether selected plant constituents affect HDAC activity or HDAC1 protein status in the human colon carcinoma cell line HT29. The polyphenols (−)-epigallocatechin-3-gallate (EGCG) and genistein (GEN) as well as two oxidative methyleugenol (ME) metabolites were shown to inhibit HDAC activity in intact HT29 cells. Concomitantly, a significant decrease of the HDAC1 protein level was observed after incubation with EGCG and GEN, whereas the investigated ME metabolites did not affect HDAC1 protein status. In conclusion, dietary compounds were found to possess promising HDAC-inhibitory properties, contributing to epigenetic alterations in colon tumor cells, which should be taken into account in further risk/benefit assessments of polyphenols and alkenylbenzenes. PMID:23476753

  19. Magnolia Extract, Magnolol, and Metabolites: Activation of Cannabinoid CB2 Receptors and Blockade of the Related GPR55

    PubMed Central

    2012-01-01

    The bark of Magnolia officinalis is used in Asian traditional medicine for the treatment of anxiety, sleeping disorders, and allergic diseases. We found that the extract and its main bioactive constituents, magnolol and honokiol, can activate cannabinoid (CB) receptors. In cAMP accumulation studies, magnolol behaved as a partial agonist (EC50 = 3.28 μM) with selectivity for the CB2 subtype, while honokiol was less potent showing full agonistic activity at CB1 and antagonistic properties at CB2. We subsequently synthesized the major metabolites of magnolol and found that tetrahydromagnolol (7) was 19-fold more potent than magnolol (EC50 CB2 = 0.170 μM) exhibiting high selectivity versus CB1. Additionally, 7 behaved as an antagonist at GPR55, a CB-related orphan receptor (KB = 13.3 μM, β-arrestin translocation assay). Magnolol and its metabolites may contribute to the biological activities of Magnolia extract via the observed mechanisms of action. Furthermore, the biphenylic compound magnolol provides a simple novel lead structure for the development of agonists for CB receptors and antagonists for the related GPR55. PMID:24900561

  20. Plant polyphenols and oxidative metabolites of the herbal alkenylbenzene methyleugenol suppress histone deacetylase activity in human colon carcinoma cells.

    PubMed

    Groh, Isabel Anna Maria; Chen, Chen; Lüske, Claudia; Cartus, Alexander Thomas; Esselen, Melanie

    2013-01-01

    Evidence has been provided that diet and environmental factors directly influence epigenetic mechanisms associated with cancer development in humans. The inhibition of histone deacetylase (HDAC) activity and the disruption of the HDAC complex have been recognized as a potent strategy for cancer therapy and chemoprevention. In the present study, we investigated whether selected plant constituents affect HDAC activity or HDAC1 protein status in the human colon carcinoma cell line HT29. The polyphenols (-)-epigallocatechin-3-gallate (EGCG) and genistein (GEN) as well as two oxidative methyleugenol (ME) metabolites were shown to inhibit HDAC activity in intact HT29 cells. Concomitantly, a significant decrease of the HDAC1 protein level was observed after incubation with EGCG and GEN, whereas the investigated ME metabolites did not affect HDAC1 protein status. In conclusion, dietary compounds were found to possess promising HDAC-inhibitory properties, contributing to epigenetic alterations in colon tumor cells, which should be taken into account in further risk/benefit assessments of polyphenols and alkenylbenzenes. PMID:23476753

  1. Top-down Targeted Metabolomics Reveals a Sulfur-Containing Metabolite with Inhibitory Activity against Angiotensin-Converting Enzyme in Asparagus officinalis.

    PubMed

    Nakabayashi, Ryo; Yang, Zhigang; Nishizawa, Tomoko; Mori, Tetsuya; Saito, Kazuki

    2015-05-22

    The discovery of bioactive natural compounds containing sulfur, which is crucial for inhibitory activity against angiotensin-converting enzyme (ACE), is a challenging task in metabolomics. Herein, a new S-containing metabolite, asparaptine (1), was discovered in the spears of Asparagus officinalis by targeted metabolomics using mass spectrometry for S-containing metabolites. The contribution ratio (2.2%) to the IC50 value in the crude extract showed that asparaptine (1) is a new ACE inhibitor. PMID:25922884

  2. Excretion of tectoridin metabolites in rat urine and bile orally administrated at different dosages and their inhibitory activity against aldose reductase.

    PubMed

    Qu, Jialin; Wu, Zhizhen; Gao, Jie; Wen, Hao; Wang, Tao; Yuan, Dan

    2014-12-01

    This study investigated the urinary and biliary excretion of tectoridin, a major active isoflavonoid found in the flowers of Pueraria thomsonii Benth. and the rhizomes of Belamcanda chinensis (L.) DC. Using UHPLC/Q-TOFMS, seven glucuronides and/or sulfated metabolites and four Phase I metabolites were simultaneously quantified in rat urine after oral administration of tectoridin at 100 and 200 mg/kg. Over a 72-h period, 14.2% and 14.7% of the tectoridin were excreted as eleven metabolites in urine, among which, two major metabolites tectorigenin-7-O-β-D-glucuronide (Te-7G) and tectorigenin accounted for 5.5-5.5% and 4.3-4.4%. Furthermore, the cumulative excretion of four glucuronides and sulfated metabolites in bile accounted for 7.3% and 3.9% of the dose within 60 h, among which, Te-7G and tectorigenin-7-O-glucuronide-4'-O-sulfate (Te-7G-4'S) accounted for 2.3-3.0% and 1.4-3.9%, respectively. The results indicate that the urine was the primary elimination route, and glucuronidation after deglycosylation at C-7 position was the major metabolic pathway of tectoridin in vivo. Moreover, the inhibitory activities of tectoridin and its five metabolites on rat lens aldose reductase were confirmed (IC₅₀: 1.4-15.5 μM), whereas irisolidone-7-O-glucuronide (Ir-7G) and irisolidone showed little activity. PMID:25256063

  3. Activity and characterization of secondary metabolites produced by a new microorganism for control of plant diseases.

    PubMed

    Ko, Wen-Hsiung; Tsou, Yi-Jung; Lin, Mei-Ju; Chern, Lih-Ling

    2010-09-30

    Microorganisms capable of utilizing vegetable tissues for growth in soils were isolated and their vegetable broth cultures were individually sprayed directly on leaves to test their ability to control Phytophthora blight of bell pepper caused by Phytophthora capsici. Liquid culture of Streptomyces strain TKA-5, a previously undescribed species obtained in this study, displayed several desirable disease control characteristics in nature, including high potency, long lasting and ability to control also black leaf spot of spoon cabbage caused by Alternaria brassicicolca. The extract was fungicidal to P. capsici but fungistatic to A. brassicicola. It was stable at high temperature and high pH. However, after exposure to pH 2 for 24h, the extract was no longer inhibitory to P. capsici although it was still strongly inhibitory to A. brassicicola. After treatment with cation or anion exchange resins, the extract lost its inhibitory effect against P. capsici but not A. brassicicola. The results suggest that the extract contained two different kinds of inhibitory metabolites, one against P. capsici with both positive and negative charges on its molecule and another against A. brassicicola with no charges on its molecule. The inhibitory metabolites were soluble in ethanol or methanol but not in water, ether or chloroform. They were dialyzable in the membrane tubing with molecular weight cut-off of 10,000, 1000 or 500 but not 100, indicating that the inhibitors have a molecular weight between 500 and 100. Results also showed that both inhibitors are not proteins. PMID:20580869

  4. Metabolite Damage and Metabolite Damage Control in Plants.

    PubMed

    Hanson, Andrew D; Henry, Christopher S; Fiehn, Oliver; de Crécy-Lagard, Valérie

    2016-04-29

    It is increasingly clear that (a) many metabolites undergo spontaneous or enzyme-catalyzed side reactions in vivo, (b) the damaged metabolites formed by these reactions can be harmful, and (c) organisms have biochemical systems that limit the buildup of damaged metabolites. These damage-control systems either return a damaged molecule to its pristine state (metabolite repair) or convert harmful molecules to harmless ones (damage preemption). Because all organisms share a core set of metabolites that suffer the same chemical and enzymatic damage reactions, certain damage-control systems are widely conserved across the kingdoms of life. Relatively few damage reactions and damage-control systems are well known. Uncovering new damage reactions and identifying the corresponding damaged metabolites, damage-control genes, and enzymes demands a coordinated mix of chemistry, metabolomics, cheminformatics, biochemistry, and comparative genomics. This review illustrates the above points using examples from plants, which are at least as prone to metabolite damage as other organisms. PMID:26667673

  5. Form-Focused Discovery Activities in English Classes

    ERIC Educational Resources Information Center

    Ogeyik, Muhlise Cosgun

    2011-01-01

    Form-focused discovery activities allow language learners to grasp various aspects of a target language by contributing implicit knowledge by using discovered explicit knowledge. Moreover, such activities can assist learners to perceive and discover the features of their language input. In foreign language teaching environments, they can be used…

  6. Activated carbon fibers and engineered forms from renewable resources

    DOEpatents

    Baker, Frederick S

    2013-02-19

    A method of producing activated carbon fibers (ACFs) includes the steps of providing a natural carbonaceous precursor fiber material, blending the carbonaceous precursor material with a chemical activation agent to form chemical agent-impregnated precursor fibers, spinning the chemical agent-impregnated precursor material into fibers, and thermally treating the chemical agent-impregnated precursor fibers. The carbonaceous precursor material is both carbonized and activated to form ACFs in a single step. The method produces ACFs exclusive of a step to isolate an intermediate carbon fiber.

  7. Activated carbon fibers and engineered forms from renewable resources

    DOEpatents

    Baker, Frederick S.

    2010-06-01

    A method of producing activated carbon fibers (ACFs) includes the steps of providing a natural carbonaceous precursor fiber material, blending the carbonaceous precursor material with a chemical activation agent to form chemical agent-impregnated precursor fibers, spinning the chemical agent-impregnated precursor material into fibers, and thermally treating the chemical agent-impregnated precursor fibers. The carbonaceous precursor material is both carbonized and activated to form ACFs in a single step. The method produces ACFs exclusive of a step to isolate an intermediate carbon fiber.

  8. Activation of the Silent Secondary Metabolite Production by Introducing Neomycin-Resistance in a Marine-Derived Penicillium purpurogenum G59

    PubMed Central

    Wu, Chang-Jing; Yi, Le; Cui, Cheng-Bin; Li, Chang-Wei; Wang, Nan; Han, Xiao

    2015-01-01

    Introduction of neomycin-resistance into a marine-derived, wild-type Penicillium purpurogenum G59 resulted in activation of silent biosynthetic pathways for the secondary metabolite production. Upon treatment of G59 spores with neomycin and dimethyl sulfoxide (DMSO), a total of 56 mutants were obtained by single colony isolation. The acquired resistance of mutants to neomycin was testified by the resistance test. In contrast to the G59 strain, the EtOAc extracts of 28 mutants inhibited the human cancer K562 cells, indicating that the 28 mutants have acquired the capability to produce bioactive metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses further indicated that diverse secondary metabolites have been newly produced in the bioactive mutant extracts. Followed isolation and characterization demonstrated that five bioactive secondary metabolites, curvularin (1), citrinin (2), penicitrinone A (3), erythro-23-O-methylneocyclocitrinol (4) and 22E-7α-methoxy-5α,6α-epoxyergosta-8(14),22-dien-3β-ol (5), were newly produced by a mutant, 4-30, compared to the G59 strain. All 1–5 were also not yet found in the secondary metabolites of other wild type P. purpurogenum strains. Compounds 1–5 inhibited human cancer K562, HL-60, HeLa and BGC-823 cells to varying extents. Both present bioassays and chemical investigations demonstrated that the introduction of neomycin-resistance into the marine-derived fungal G59 strain could activate silent secondary metabolite production. The present work not only extended the previous DMSO-mediated method for introducing drug-resistance in fungi both in DMSO concentrations and antibiotics, but also additionally exemplified effectiveness of this method for activating silent fungal secondary metabolites. This method could be applied to other fungal isolates to elicit their metabolic potentials to investigate secondary metabolites from silent biosynthetic pathways. PMID:25913704

  9. Isolation and Identification of Twelve Metabolites of Isocorynoxeine in Rat Urine and their Neuroprotective Activities in HT22 Cell Assay

    PubMed Central

    Qi, Wen; Chen, Fangfang; Sun, Jiahong; Simpkins, James W.; Yuan, Dan

    2015-01-01

    Isocorynoxeine, one of the major alkaloids from Uncaria Hook, shows the effects of lowering blood pressure, vasodilatation, and protection against ischemia-induced neuronal damage. In this paper, the metabolism of isocorynoxeine was investigated in rats. Twelve metabolites and the parent drug were isolated by using solvent extraction and repeated chromatographic methods, and determined by spectroscopic methods including UV, MS, NMR, and CD experiments. Seven new compounds were identified as 11-hydroxyisocorynoxeine, 5-oxoisocorynoxeinic acid-22-O-β-D-glucuronide, 10-hydroxyisocorynoxeine, 17-O-demethyl-16,17-dihydro-5-oxoisocorynoxeine, 5-oxoisocorynoxeinic acid, 21-hydroxy-5-oxoisocorynoxeine, and oxireno[18,19]-5-oxoisocorynoxeine, together with six known compounds identified as isocorynoxeine, 18,19-dehydrocorynoxinic acid, 18,19-dehydrocorynoxinic acid B, corynoxeine, isocorynoxeine-N-oxide, and corynoxeine-N-oxide. Possible metabolic pathways of isocorynoxeine are proposed. Furthermore, the activity assay for the parent drug and some of its metabolites showed that isocorynoxeine exhibited a significant neuroprotective effect against glutamate-induced HT22 cell death at the maximum concentration. However, little or weak neuroprotective activities were observed for M-3, M-6, M-7, and M-10. Our present study is important to further understand their metabolic fate and disposition in humans. PMID:25519834

  10. Isolation and identification of twelve metabolites of isocorynoxeine in rat urine and their neuroprotective activities in HT22 cell assay.

    PubMed

    Qi, Wen; Chen, Fangfang; Sun, Jiahong; Simpkins, James W; Yuan, Dan

    2015-01-01

    Isocorynoxeine, one of the major alkaloids from Uncaria Hook, shows the effects of lowering blood pressure, vasodilatation, and protection against ischemia-induced neuronal damage. In this paper, the metabolism of isocorynoxeine was investigated in rats. Twelve metabolites and the parent drug were isolated by using solvent extraction and repeated chromatographic methods, and determined by spectroscopic methods including UV, MS, NMR, and CD experiments. Seven new compounds were identified as 11-hydroxyisocorynoxeine, 5-oxoisocorynoxeinic acid-22-O-β-D-glucuronide, 10-hydroxyisocorynoxeine, 17-O-demethyl-16,17-dihydro-5-oxoisocorynoxeine, 5-oxoisocorynoxeinic acid, 21-hydroxy-5-oxoisocorynoxeine, and oxireno[18, 19]-5-oxoisocorynoxeine, together with six known compounds identified as isocorynoxeine, 18,19-dehydrocorynoxinic acid, 18,19-dehydrocorynoxinic acid B, corynoxeine, isocorynoxeine-N-oxide, and corynoxeine-N-oxide. Possible metabolic pathways of isocorynoxeine are proposed. Furthermore, the activity assay for the parent drug and some of its metabolites showed that isocorynoxeine exhibited a significant neuroprotective effect against glutamate-induced HT22 cell death at the maximum concentration. However, little or weak neuroprotective activities were observed for M-3, M-6, M-7, and M-10. Our present study is important to further understand their metabolic fate and disposition in humans. PMID:25519834

  11. Anti-phytopathogenic activity of sporothriolide, a metabolite from endophyte Nodulisporium sp. A21 in Ginkgo biloba.

    PubMed

    Cao, Ling-Ling; Zhang, Ying-Ying; Liu, Ying-Jie; Yang, Ting-Ting; Zhang, Jin-Long; Zhang, Zheng-Guang; Shen, Li; Liu, Jun-Yan; Ye, Yong-Hao

    2016-05-01

    Phytopathogenic fungi such as Rhizoctonia solani and Sclerotinia sclerotiorum caused multiple plant diseases resulting in severe loss of crop production. Increasing documents endorsed that endophytes are a striking resource pool for numerous metabolites with various bioactivities such as anti-fungal. Here we reported the characterization and anti-phytopathogenic activity of sporothriolide, a metabolite produced by Nodulisporium sp. A21-an endophytic fungus in the leaves of Ginkgo biloba. Among the total twenty-five endophytic fungi isolated from the healthy leaves of G. biloba, the fermentation broth (FB) of the strain A21 was found potently inhibitory activity against R. solani and S. sclerotiorum using mycelia growth inhibition method. A21 was then identified as Nodulisporium sp., the asexual stage of Hypoxylon sp., by microscopic examination and ITS rDNA sequence data comparison. Under the bioassay-guided fractionation, sporothriolide was isolated from the petroleum ether extract of the FB of A21, whose structure was established by integrated interpretation of HR-ESI-MS and (1)H- and (13)C-NMR. Furthermore, the crystal structure of sporothriolide was first reported. In addition, sporothriolide was validated to be potently antifungal against R. solani, S. sclerotiorum and inhibit conidium germination of Magnaporthe oryzae in vitro and in vivo, indicating that it could be used as a lead compound for new fungicide development. PMID:27017876

  12. Mass spectrometry-based metabolite profiling and antioxidant activity of Aloe vera ( Aloe barbadensis Miller) in different growth stages.

    PubMed

    Lee, Sarah; Do, Seon-Gil; Kim, Sun Yeou; Kim, Jinwan; Jin, Yoojeong; Lee, Choong Hwan

    2012-11-14

    Metabolite profiling of four different-sized Aloe vera plants was performed using gas chromatography-ion trap-mass spectrometry (GC-IT-MS) and ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) with multivariate analysis. Amino acids, sugars, and organic acids related to growth and development were identified by sizes. In particular, the relative contents of glucose, fructose, alanine, valine, and aspartic acid increased gradually as the size of the aloe increased. Anthraquinone derivatives such as 7-hydroxy-8-O-methylaloin, 7-hydroxyaloin A, and 6'-malonylnataloins A and B increased gradually, whereas chromone derivatives decreased continuously as the size of the aloe increased. The A30 aloe (size = 20-30 cm) with relatively high contents of aloins A and B, was suggested to have antioxidant components showing the highest antioxidant activity among the four different sizes of aloe. These data suggested that MS-based metabolomic approaches can illuminate metabolite changes associated with growth and development and can explain their change of antioxidant activity. PMID:23050594

  13. Mechanistic toxicodynamic model for receptor-mediated toxicity of diazoxon, the active metabolite of diazinon, in Daphnia magna.

    PubMed

    Kretschmann, Andreas; Ashauer, Roman; Hitzfeld, Kristina; Spaak, Piet; Hollender, Juliane; Escher, Beate I

    2011-06-01

    The organothiophosphate diazinon inhibits the target site acetylcholinesterase only after activation to its metabolite diazoxon. Commonly, the toxicity of xenobiotics toward aquatic organisms is expressed as a function of the external concentration and the resulting effect on the individual level after fixed exposure times. This approach does not account for the time dependency of internal processes such as uptake, metabolism, and interaction of the toxicant with the target site. Here, we develop a mechanistic toxicodynamic model for Daphnia magna and diazoxon, which accounts for the inhibition of the internal target site acetylcholinesterase and its link to the observable effect, immobilization, and mortality. The model was parametrized by experiments performed in vitro with the active metabolite diazoxon on enzyme extracts and in vivo with the parent compound diazinon. The mechanism of acetylcholinesterase inhibition was shown to occur irreversibly in two steps via formation of a reversible enzyme-inhibitor complex. The corresponding kinetic parameters revealed a very high sensitivity of acetylcholinesterase from D. magna toward diazoxon, which corresponds well with the high toxicity of diazinon toward this species. Recovery of enzyme activity but no recovery from immobilization was observed after in vivo exposure to diazinon. The toxicodynamic model combining all in vitro and in vivo parameters was successfully applied to describe the time course of immobilization in dependence of acetylcholinesterase activity during exposure to diazinon. The threshold value for enzyme activity below which immobilization set in amounted to 40% of the control activity. Furthermore, the model enabled the prediction of the time-dependent diazoxon concentration directly present at the target site. PMID:21539304

  14. IDO1 Metabolites Activate β-catenin Signaling to Promote Cancer Cell Proliferation and Colon Tumorigenesis in Mice

    PubMed Central

    Thaker, Ameet I.; Rao, M Suprada; Bishnupuri, Kumar S.; Kerr, Thomas A; Foster, Lynne; Marinshaw, Jeffrey M.; Newberry, Rodney D.; Stenson, William F.; Ciorba, Matthew A

    2013-01-01

    BACKGROUND & AIMS Indoleamine 2,3 dioxygenase-1 (IDO1) catabolizes tryptophan along the kynurenine pathway. Though IDO1 is expressed in inflamed and neoplastic epithelial cells of the colon, its role in colon tumorigenesis is not well understood. We used genetic and pharmacologic approaches to manipulate IDO1 activity in mice with colitis-associated cancer and human colon cancer cell lines. METHODS C57Bl6 wild type (control), IDO1−/−, Rag1−/−, Rag1/IDO1 double knockout mice were exposed to azoxymethane and dextran sodium sulfate (DSS) to induce colitis and tumorigenesis. Colitis severity was assessed by measurements of disease activity, cytokine levels and histologic analysis. In vitro experiments were conducted using HCT116 and HT29 human colon cancer cells. 1-methyl tryptophan and small interfering RNA were used to inhibit IDO1. Kynurenine pathway metabolites were used to simulate IDO1 activity. RESULTS C57Bl6 mice given pharmacologic inhibitors of IDO1 and IDO1−/− mice had lower tumor burdens and reduced proliferation in the neoplastic epithelium following administration of DSS and azoxymethane than control mice. These reductions were also observed in Rag1/IDO1 double knockout mice compared to Rag1−/− mice (which lack mature adaptive immunity). In human colon cancer cells, blockade of IDO1 activity reduced nuclear and activated β-catenin, transcription of its target genes (cyclin D1 and Axin2), and ultimately proliferation. Exogenous administration of IDO1 pathway metabolites kynurenine and quinolinic acid led to activation of β-catenin and proliferation of human colon cancer cells, and increased tumor growth in mice. CONCLUSIONS IDO1, which catabolizes tryptophan, promotes colitis-associated tumorigenesis in mice, independent of its ability to limit T-cell mediated immune surveillance. The epithelial cell-autonomous survival advantage provided by IDO1 to colon epithelial cells indicate its potential as a therapeutic target. PMID:23669411

  15. 20(S)-protopanaxadiol, an active ginseng metabolite, exhibits strong antidepressant-like effects in animal tests.

    PubMed

    Xu, Changjiang; Teng, Jijun; Chen, Weidong; Ge, Qiang; Yang, Zhiqi; Yu, Chunying; Yang, Zirong; Jia, William

    2010-12-01

    Ginseng has been used for mood adjustment in traditional Chinese medicine for thousands of years. Our previous study has shown that, total ginsenosides, the major pharmacologically functional ingredients of ginseng, possess antidepressant activity. In the present study, we hypothesized that an intestinal metabolite of ginseng, 20(S)-protopanaxadiol (code name S111), as a post metabolism compound (PMC) of ingested ginsenosides, may be responsible for the antidepressant activity of ginseng. To test this hypothesis, antidepressant-like activity of orally given S111 was measured in animal tests including tail suspension test, forced swimming test and rat olfactory bulbectomy depression model. In all those tests, S111 demonstrated antidepressant-like activity as potent as fluoxetine. S111 treated bulbectomy animals had higher levels of monoamine neurotransmitters in the brain and in vitro reuptake assay showed that S111 had a mild inhibitory effect. Furthermore, S111 but not fluoxetine significantly reduced brain oxidative stress and down-regulated serum corticosterone concentration in bulbectomy animals. No disturbance to central nervous system (CNS) normal functions were found in S111 treated animals. These results suggest that the ginseng active metabolite S111 is a potential antidepressant. Since the monoamine reuptake activity of this compound is rather weak, it remains to be investigated whether its antidepressant-like effect is by mechanisms that are different from current antidepressants. Furthermore, this study has demonstrated that post metabolism compounds (PMCs) of herb medicines such as S111 may be a novel source for drug discovery from medicinal herbs. PMID:20647027

  16. Inactivation of glyceraldehyde-3-phosphate dehydrogenase by a reactive metabolite of acetaminophen and mass spectral characterization of an arylated active site peptide.

    PubMed

    Dietze, E C; Schäfer, A; Omichinski, J G; Nelson, S D

    1997-10-01

    Acetaminophen (4'-hydroxyacetanilide, APAP) is a widely used analgesic and antipyretic drug that can cause hepatic necrosis under some circumstances via cytochrome P450-mediated oxidation to a reactive metabolite, N-acetyl-p-benzoquinone imine (NAPQI). Although the mechanism of hepatocellular injury caused by APAP is not fully understood, it is known that NAPQI forms covalent adducts with several hepatocellular proteins. Reported here is the identification of one of these proteins as glyceraldehyde-3-phosphate dehydrogenase [GAPDH, D-glyceraldehyde-3-phosphate: NAD+ oxidoreductase (phosphorylating), EC 1.2.1.12]. Two hours after the administration of hepatotoxic doses of [14C]APAP to mice, at a time prior to overt cell damage, hepatocellular GAPDH activity was significantly decreased concurrent with the formation of a 14C-labeled GAPDH adduct. A nonhepatotoxic regioisomer of APAP, 3'-hydroxyacetanilide (AMAP), was found to decrease GAPDH activity to a lesser extent than APAP, and radiolabel from [14C]AMAP bound to a lesser extent to GAPDH at a time when its overall binding to hepatocellular proteins was almost equivalent to that of APAP. In order to determine the nature of the covalent adduct between GAPDH and APAP, its major reactive and toxic metabolite, NAPQI, was incubated with purified porcine muscle GAPDH. Microsequencing analysis and fast atom bombardment mass spectrometry (FAB-MS) with collision-induced dissociation (CID) were used to characterize one of the adducts as APAP bound to the cysteinyl sulfhydryl group of Cys-149 in the active site peptide of GAPDH. PMID:9348431

  17. Allocation of secondary metabolites, photosynthetic capacity, and antioxidant activity of Kacip Fatimah (Labisia pumila Benth) in response to CO2 and light intensity.

    PubMed

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E; Karimi, Ehsan; Ghasemzadeh, Ali

    2014-01-01

    A split plot 3 by 4 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites, soluble sugar, phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity, leaf gas exchange, chlorophyll content, antioxidant activity (DPPH), and lipid peroxidation under three levels of CO2 (400, 800, and 1200 μ mol/mol) and four levels of light intensity (225, 500, 625, and 900 μ mol/m(2)/s) over 15 weeks in Labisia pumila. The production of plant secondary metabolites, sugar, chlorophyll content, antioxidant activity, and malondialdehyde content was influenced by the interactions between CO2 and irradiance. The highest accumulation of secondary metabolites, sugar, maliondialdehyde, and DPPH activity was observed under CO2 at 1200 μ mol/mol + light intensity at 225 μ mol/m(2)/s. Meanwhile, at 400 μ mol/mol CO2 + 900 μ mol/m(2)/s light intensity the production of chlorophyll and maliondialdehyde content was the highest. As CO2 levels increased from 400 to 1200 μ mol/mol the photosynthesis, stomatal conductance, f v /f m (maximum efficiency of photosystem II), and PAL activity were enhanced. The production of secondary metabolites displayed a significant negative relationship with maliondialdehyde indicating lowered oxidative stress under high CO2 and low irradiance improved the production of plant secondary metabolites that simultaneously enhanced the antioxidant activity (DPPH), thus improving the medicinal value of Labisia pumila under this condition. PMID:24683336

  18. Allocation of Secondary Metabolites, Photosynthetic Capacity, and Antioxidant Activity of Kacip Fatimah (Labisia pumila Benth) in Response to CO2 and Light Intensity

    PubMed Central

    Jaafar, Hawa Z. E.; Karimi, Ehsan; Ghasemzadeh, Ali

    2014-01-01

    A split plot 3 by 4 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites, soluble sugar, phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity, leaf gas exchange, chlorophyll content, antioxidant activity (DPPH), and lipid peroxidation under three levels of CO2 (400, 800, and 1200 μmol/mol) and four levels of light intensity (225, 500, 625, and 900 μmol/m2/s) over 15 weeks in Labisia pumila. The production of plant secondary metabolites, sugar, chlorophyll content, antioxidant activity, and malondialdehyde content was influenced by the interactions between CO2 and irradiance. The highest accumulation of secondary metabolites, sugar, maliondialdehyde, and DPPH activity was observed under CO2 at 1200 μmol/mol + light intensity at 225 μmol/m2/s. Meanwhile, at 400 μmol/mol CO2 + 900 μmol/m2/s light intensity the production of chlorophyll and maliondialdehyde content was the highest. As CO2 levels increased from 400 to 1200 μmol/mol the photosynthesis, stomatal conductance, fv/fm (maximum efficiency of photosystem II), and PAL activity were enhanced. The production of secondary metabolites displayed a significant negative relationship with maliondialdehyde indicating lowered oxidative stress under high CO2 and low irradiance improved the production of plant secondary metabolites that simultaneously enhanced the antioxidant activity (DPPH), thus improving the medicinal value of Labisia pumila under this condition. PMID:24683336

  19. The Oxidized Linoleic Acid Metabolite-Cytochrome P450 System is Active in Biopsies from Patients with Inflammatory Dental Pain

    PubMed Central

    Ruparel, Shivani; Hargreaves, Kenneth M.; Eskander, Michael; Rowan, Spencer; de Almeida, Jose F.A.; Roman, Linda; Henry, Michael A.

    2013-01-01

    Endogenous TRPV1 agonists such as oxidized linoleic acid metabolites (OLAMs) and the enzymes releasing them [e.g., cytochrome P450 (CYP)], are up-regulated following inflammation in the rat. However, it is not known if such agonists are elevated in human inflammatory pain conditions. Since TRPV1 is expressed in human dental pulp nociceptors, we hypothesized that OLAM-CYP machinery is active in this tissue type and is increased under painful inflammatory conditions such as irreversible pulpitis (IP). The aim of this study was to compare CYP expression and linoleic acid (LA) metabolism in normal versus inflamed human dental pulp. Our data showed that exogenous LA metabolism was significantly increased in IP tissues compared to normal tissues and that pretreatment with a CYP inhibitor, ketoconazole, significantly inhibited LA metabolism. Additionally, extracts obtained from LA-treated inflamed tissues, evoked significant inward currents in TG neurons, and were blocked by pretreatment with the TRPV1 antagonist, IRTX. Moreover, extracts obtained from ketoconazole-pretreated inflamed tissues significantly reduced inward currents in TG neurons. These data suggest that LA metabolites produced in human inflamed tissues act as TRPV1 agonists and that the metabolite production can be targeted by CYP inhibition. In addition, immunohistochemical analysis of two CYP isoforms, CYP2J and CYP3A1, were shown to be predominately expressed in immune cells infiltrating the inflamed dental pulp, emphasizing the paracrine role of CYP enzymes in OLAM regulation. Collectively, our data indicates that the machinery responsible for OLAM production is up-regulated during inflammation and can be targeted to develop potential analgesics for inflammatory-induced dental pain. PMID:23867730

  20. Protopanaxadiol, an Active Ginseng Metabolite, Significantly Enhances the Effects of Fluorouracil on Colon Cancer

    PubMed Central

    Wang, Chong-Zhi; Zhang, Zhiyu; Wan, Jin-Yi; Zhang, Chun-Feng; Anderson, Samantha; He, Xin; Yu, Chunhao; He, Tong-Chuan; Qi, Lian-Wen; Yuan, Chun-Su

    2015-01-01

    In this study, we evaluated the effects of protopanaxadiol (PPD), a gut microbiome induced ginseng metabolite, in increasing the anticancer effects of a chemotherapeutic agent fluorouracil (5-FU) on colorectal cancer. An in vitro HCT-116 colorectal cancer cell proliferation test was conducted to observe the effects of PPD, 5-FU and their co-administration and the related mechanisms of action. Then, an in vivo xenografted athymic mouse model was used to confirm the in vitro data. Our results showed that the human gut microbiome converted ginsenoside compound K to PPD as a metabolite. PPD and 5-FU significantly inhibited HCT-116 cell proliferation in a concentration-dependent manner (both p < 0.01), and the effects of 5-FU were very significantly enhanced by combined treatment with PPD (p < 0.01). Cell cycle evaluation demonstrated that 5-FU markedly induced the cancer cell S phase arrest, while PPD increased arrest in G1 phase. Compared to the control, 5-FU and PPD increased apoptosis, and their co-administration significantly increased the number of apoptotic cells (p < 0.01). Using bioluminescence imaging, in vivo data revealed that 5-FU significantly reduced the tumor growth up to Day 20 (p < 0.05). PPD and 5-FU co-administration very significantly reduced the tumor size in a dose-related manner (p < 0.01 compared to the 5-FU alone). The quantification of the tumor size and weight changes for 43 days supported the in vivo imaging data. Our results demonstrated that the co-administration of PPD and 5-FU significantly inhibited the tumor growth, indicating that PPD significantly enhanced the anticancer action of 5-FU, a commonly used chemotherapeutic agent. PPD may have a clinical value in 5-FU’s cancer therapeutics. PMID:25625815

  1. Colonic metabolites of berry polyphenols: the missing link to biological activity?

    PubMed

    Williamson, Gary; Clifford, Michael N

    2010-10-01

    The absorption of dietary phenols, polyphenols and tannins (PPT) is an essential step for biological activity and effects on health. Although a proportion of these dietary bioactive compounds are absorbed intact, depending on their chemical structure and the nature of any attached moiety (e.g. sugar, organic acid), substantial amounts of lower molecular weight catabolites are absorbed after biotransformation by the colon microflora. The main products in the colon are (a) benzoic acids (C6-C1), especially benzoic acid and protocatechuic acid; (b) phenylacetic acids (C6-C2), especially phenylacetic acid per se; (c) phenylpropionic acids (C6-C3), where the latter are almost entirely in the dihydro form, notably dihydrocaffeic acid, dihydroferulic acid, phenylpropionic acid and 3-(3'-hydroxyphenyl)-propionic acid. As a result of this biotransformation, some of these compounds can each reach mm concentrations in faecal water. Many of these catabolites are efficiently absorbed in the colon, appear in the blood and are ultimately excreted in the urine. In the case of certain polyphenols, such as anthocyanins, these catabolites are major products in vivo; protocatechuic acid is reported to represent a substantial amount of the ingested dose of cyanidin-3-O-glucoside. The major catabolites of berries, and especially blackcurrants, are predicted based on compositional data for polyphenols from berries and other sources. Since microbial catabolites may be present at many sites of the body in higher concentration than the parent compound, it is proposed that at least a part of the biological activities ascribed to berry polyphenols and other PPT are due to their colonic catabolites. PMID:20955650

  2. Effects of Secondary Plant Metabolites on Microbial Populations: Changes in Community Structure and Metabolic Activity in Contaminated Environments.

    PubMed

    Musilova, Lucie; Ridl, Jakub; Polivkova, Marketa; Macek, Tomas; Uhlik, Ondrej

    2016-01-01

    Secondary plant metabolites (SPMEs) play an important role in plant survival in the environment and serve to establish ecological relationships between plants and other organisms. Communication between plants and microorganisms via SPMEs contained in root exudates or derived from litter decomposition is an example of this phenomenon. In this review, the general aspects of rhizodeposition together with the significance of terpenes and phenolic compounds are discussed in detail. We focus specifically on the effect of SPMEs on microbial community structure and metabolic activity in environments contaminated by polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Furthermore, a section is devoted to a complex effect of plants and/or their metabolites contained in litter on bioremediation of contaminated sites. New insights are introduced from a study evaluating the effects of SPMEs derived during decomposition of grapefruit peel, lemon peel, and pears on bacterial communities and their ability to degrade PCBs in a long-term contaminated soil. The presented review supports the "secondary compound hypothesis" and demonstrates the potential of SPMEs for increasing the effectiveness of bioremediation processes. PMID:27483244

  3. Light-induced biochemical variations in secondary metabolite production and antioxidant activity in callus cultures of Stevia rebaudiana (Bert).

    PubMed

    Ahmad, Naveed; Rab, Abdur; Ahmad, Nisar

    2016-01-01

    Stevia rebaudiana (S. rebaudiana) is a very important species with worldwide medicinal and commercial uses. Light is one of the major elicitors that fluctuate morphogenic potential and biochemical responses. In the present study, we investigated the effect of various spectral lights on biomass accumulation and secondary metabolite production in callus cultures of S. rebaudiana. Leaf explants were placed on Murashige and Skoog (MS) medium and exposed to various spectral lights. 6-Benzyle adenine (BA) and 2, 4-dichlorophenoxy acetic acid (2, 4-D; 2.0 mgl(-1)) were used for callus induction. The control light (16/8h) produced optimum callogenic response (92.73%) than other colored lights. Compared to other colored lights, control grown cultures displayed maximum biomass accumulation (5.78 gl(-1)) during a prolonged log phase at the 18th day of growth kinetics. Cultures grown under blue light enhanced total phenolic content (TPC; 102.32 μg/g DW), total flavonoid content (TFC; 22.07 μg/g DW) and total antioxidant capacity (TAC; 11.63 μg/g DW). On the contrary, green and red lights improved reducing power assay (RPA; 0.71Fe(II)g(-1) DW) and DPPH-radical scavenging activity (DRSA; 80%). Herein, we concluded that the utilization of colored lights is a promising strategy for enhanced production of antioxidant secondary metabolites in callus cultures of S. rebaudiana. PMID:26688290

  4. Effects of Secondary Plant Metabolites on Microbial Populations: Changes in Community Structure and Metabolic Activity in Contaminated Environments

    PubMed Central

    Musilova, Lucie; Ridl, Jakub; Polivkova, Marketa; Macek, Tomas; Uhlik, Ondrej

    2016-01-01

    Secondary plant metabolites (SPMEs) play an important role in plant survival in the environment and serve to establish ecological relationships between plants and other organisms. Communication between plants and microorganisms via SPMEs contained in root exudates or derived from litter decomposition is an example of this phenomenon. In this review, the general aspects of rhizodeposition together with the significance of terpenes and phenolic compounds are discussed in detail. We focus specifically on the effect of SPMEs on microbial community structure and metabolic activity in environments contaminated by polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Furthermore, a section is devoted to a complex effect of plants and/or their metabolites contained in litter on bioremediation of contaminated sites. New insights are introduced from a study evaluating the effects of SPMEs derived during decomposition of grapefruit peel, lemon peel, and pears on bacterial communities and their ability to degrade PCBs in a long-term contaminated soil. The presented review supports the “secondary compound hypothesis” and demonstrates the potential of SPMEs for increasing the effectiveness of bioremediation processes. PMID:27483244

  5. Degradation of sec-hexylbenzene and its metabolites by a biofilm-forming yeast Trichosporon asahii B1 isolated from oil-contaminated sediments in Quangninh coastal zone, Vietnam.

    PubMed

    Nhi-Cong, Le Thi; Mai, Cung Thi Ngoc; Minh, Nghiem Ngoc; Ha, Hoang Phuong; Lien, Do Thi; Tuan, Do Van; Quyen, Dong Van; Ike, Michihiko; Uyen, Do Thi To

    2016-01-01

    This article reports on the ability of yeast Trichosporon asahii B1 biofilm-associated cells, compared with that of planktonic cells, to transform sec-hexylbenzene and its metabolites. This B1 strain was isolated from a petroleum-polluted sediment collected in the QuangNinh coastal zones in Vietnam, and it can transform the branched aromatic hydrocarbons into a type of forming biofilm (pellicle) more efficiency than that the planktonic forms can. In the biofilm cultivation, seven metabolites, including acetophenone, benzoic acid, 2,3-dihydroxybenzoic acid, β-methylcinnamic acid, 2-phenylpropionic acid, 3-phenylbutyric acid, and 5-phenylhexanoic acid were extracted by ethyl acetate and analyzed by HPLC and GC-MS. In contrast, in the planktonic cultivation, only three of these intermediates were found. An individual metabolite was independently used as an initial substrate to prove its degradation by biofilm and planktonic types. The degradation of these products indicated that their inoculation with B1 biofilms was indeed higher than that observed in their inoculation with B1 planktonic cells. This is the first report on the degradation of sec-hexylbenzene and its metabolites by a biofilm-forming Trichosporon asahii strain. These results enhance our understanding of the degradation of branched-side-chain alkylbenzenes by T. asahii B1 biofilms and give a new insight into the potential role of biofilms formed by such species in the bioremediation of other recalcitrant aromatic compounds. PMID:26654204

  6. Observation of an Unusual Electronically Distorted Semiquinone Radical of PCB Metabolites in the Active Site of Prostaglandin H Synthase-2

    PubMed Central

    Wangpradit, Orarat; Moman, Edelmiro; Nolan, Kevin B.; Buettner, Garry R.; Robertson, Larry W.; Luthe, Gregor

    2013-01-01

    The activation of the metabolites of airborne polychlorinated biphenyls (PCBs) into highly reactive radicals is of fundamental importance. We found that human recombinant prostaglandin H synthase-2 (hPGHS-2) biotransforms dihydroxy-PCBs, such as 4-chlorobiphenyl-2′,5′-hydroquinone (4-CB-2′,5′H2Q), into semiquinone radicals via one-electron oxidation. Using electron paramagnetic resonance (EPR) spectroscopy, we observed the formation of the symmetric quartet spectrum (1:3:3:1 by area) of 4-chlorobiphenyl-2′,5′-semiquinone radical (4-CB-2′,5′-SQ•−) from 4-CB-2′,5′H2Q. This spectrum changed to an asymmetric spectrum with time: the change can be explained as the overlap of two different semiquinone radical species. Hindered rotation of the 4-CB-2′,5′-SQ•− appears not to be a major factor for the change in lineshape because increasing the viscosity of the medium with glycerol produced no significant change in lineshape. Introduction of a fluorine, which increases the steric hindrance for rotation of the dihydroxy-PCB studied, also produced no significant changes. An in silico molecular docking model of 4-CB-2′,5′H2Q in the peroxidase site of hPGHS-2 together with ab initio quantum mechanical studies indicate that the close proximity of a negatively charged carboxylic acid in the peroxidase active site may be responsible for the observed perturbation in the spectrum. This study provides new insights into the formation of semiquinones from PCB metabolites and underscores the potential role of PGHS-2 in the metabolic activation of PCBs. PMID:20843536

  7. Pore-forming activity of clostridial binary toxins.

    PubMed

    Knapp, O; Benz, R; Popoff, M R

    2016-03-01

    Clostridial binary toxins (Clostridium perfringens Iota toxin, Clostridium difficile transferase, Clostridium spiroforme toxin, Clostridium botulinum C2 toxin) as Bacillus binary toxins, including Bacillus anthracis toxins consist of two independent proteins, one being the binding component which mediates the internalization into cell of the intracellularly active component. Clostridial binary toxins induce actin cytoskeleton disorganization through mono-ADP-ribosylation of globular actin and are responsible for enteric diseases. Clostridial and Bacillus binary toxins share structurally and functionally related binding components which recognize specific cell receptors, oligomerize, form pores in endocytic vesicle membrane, and mediate the transport of the enzymatic component into the cytosol. Binding components retain the global structure of pore-forming toxins (PFTs) from the cholesterol-dependent cytotoxin family such as perfringolysin. However, their pore-forming activity notably that of clostridial binding components is more related to that of heptameric PFT family including aerolysin and C. perfringens epsilon toxin. This review focuses upon pore-forming activity of clostridial binary toxins compared to other related PFTs. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale. PMID:26278641

  8. Effects of the microbial secondary metabolite benzothiazole on the nutritional physiology and enzyme activities of Bradysia odoriphaga (Diptera: Sciaridae).

    PubMed

    Zhao, Yunhe; Xu, Chunmei; Wang, Qiuhong; Wei, Yan; Liu, Feng; Xu, Shuangyu; Zhang, Zhengqun; Mu, Wei

    2016-05-01

    Bradysia odoriphaga (Diptera: Sciaridae) is the major pest that damages Chinese chive production. As a volatile compound derived from microbial secondary metabolites, benzothiazole has been determined to possess fumigant activity against B. odoriphaga. However, the mechanism of action of benzothiazole is not well understood. In the present study, fourth-instar larvae of B. odoriphaga were exposed to LC10 and LC30 of benzothiazole. Sublethal concentrations (LC10 and LC30) of benzothiazole significantly reduced the food consumption of the larvae on the second day after treatment (2 DAT). However, there were no significant changes in pupal weight among the different treatments. We also measured the protein, lipid, carbohydrate, and trehalose contents and the digestive enzyme activities of the larvae, and the results suggest that benzothiazole reduced the nutrient accumulation and decreased the digestive enzyme activities of B. odoriphaga. In addition, the activity of glutathione S-transferase was significantly decreased at 6h after treatment with benzothiazole, whereas general esterase activities were significantly increased at 6 and 24h after treatment. The results of this study indicate that benzothiazole interferes in the normal food consumption and digestion process by decreasing the activities of digestive enzymes. These results provide valuable information for understanding the toxicity of benzothiazole and for exploring volatile compound for the control of this pest. PMID:27017881

  9. Histopathology, enzyme activities, and PAH metabolites in English sole collected near coastal pulp mills

    SciTech Connect

    Brand, D.G.

    1995-12-31

    The bottom-feeding flatfish, English sole (Pleuronectes vetulus), is widely distributed along the B.C. Pacific coast and fulfills a majority of the requirements as a sentinel species for environmental effects monitoring programs. Studies involving the use of histopathological, biochemical, and chemical tools with English sole collected near the vicinity of B.C. pulp mills are currently being conducted. Analysis, to date, has revealed idiopathic liver lesions to be strongly dependent on location of capture with a prevalence of 30% preneoplastic and neoplastic lesions found in fish collected near pulp mills. All fish residing near pulp mills show hepatocellular hemosiderosis, an iron storage disorder. The mixed-function oxidizing enzyme, EROD, was found to be induced in fish collected near pulp mills. However, the levels of conjugating enzymes, GST and UDP-GT, were found to be unchanged when compared with reference fish. PAH metabolites, measured as FACs in bile, are also present in English sole collected from the mill sites and the conjugated derivatives are presently being identified by HPLC/ES-MS techniques, The relationships between these observations will be discussed.

  10. mu Opioid receptor-mediated G-protein activation by heroin metabolites: evidence for greater efficacy of 6-monoacetylmorphine compared with morphine.

    PubMed

    Selley, D E; Cao, C C; Sexton, T; Schwegel, J A; Martin, T J; Childers, S R

    2001-08-15

    The efficacy of heroin metabolites for the stimulation of mu opioid receptor-mediated G-protein activation was investigated using agonist-stimulated [(35)S]guanosine-5'-O-(gamma-thio)-triphosphate binding. In rat thalamic membranes, heroin and its primary metabolite, 6-monoacetylmorphine (6-MAM), were more efficacious than morphine or morphine-6-beta D-glucuronide. This increased efficacy was not due to increased action of heroin and 6-MAM at delta receptors, as determined by competitive antagonism by naloxone, lack of antagonism by naltrindole, and competitive partial antagonism with morphine. In agreement with this interpretation, the same relative efficacy profile of heroin and its metabolites was observed at the cloned human mu opioid receptor expressed in C6 glioma cells. Moreover, these efficacy differences were GDP-dependent in a manner consistent with accepted mechanisms of receptor-mediated G-protein activation. The activity of heroin was attributed to in vitro deacetylation to 6-MAM, as confirmed by HPLC analysis. These results indicate that the heroin metabolite 6-MAM possesses higher efficacy than other heroin metabolites at mu opioid receptors, which may contribute to the higher efficacy of heroin compared with morphine in certain behavioral paradigms in vivo. PMID:11448454

  11. Role of activation in alveolar macrophage-mediated suppression of the plaque-forming cell response.

    PubMed Central

    Mbawuike, I N; Herscowitz, H B

    1988-01-01

    Alveolar macrophages (AM) are highly suppressive of the in vitro plaque-forming cell (PFC) response of spleen cells obtained from mice primed with sheep erythrocytes. Comparison of macrophage populations obtained from disparate anatomical sites revealed that although in both cases there was a cell-concentration-dependent suppression of the PFC response, resident AM or AM activated as a result of intravenous injection of Mycobacterium bovis BCG were equally suppressive at the doses examined. Although there was a similar dose-dependent suppression with peritoneal macrophages, BCG-activated cells were more suppressive of the PFC response than were resident cells. In contrast, splenic macrophages at comparable concentrations were not at all suppressive. Resident AM exhibited significantly lower levels of 5'-nucleotidase activity than did resident peritoneal macrophages. Macrophage-mediated suppression of the in vitro PFC response could not be attributed to the release of toxic oxygen metabolites (H2O2, O2- ,and .OH) or prostaglandins, since the addition of catalase, superoxide dismutase, 2-mercaptoethanol, or indomethacin did not completely reverse suppression. These results suggest that the lung microenvironment may maintain AM in an activated state which contributes to their potential immunoregulatory functions. PMID:2830191

  12. Thuringiensin: A Thermostable Secondary Metabolite from Bacillus thuringiensis with Insecticidal Activity against a Wide Range of Insects

    PubMed Central

    Liu, Xiaoyan; Ruan, Lifang; Peng, Donghai; Li, Lin; Sun, Ming; Yu, Ziniu

    2014-01-01

    Thuringiensin (Thu), also known as β-exotoxin, is a thermostable secondary metabolite secreted by Bacillus thuringiensis. It has insecticidal activity against a wide range of insects, including species belonging to the orders Diptera, Coleoptera, Lepidoptera, Hymenoptera, Orthoptera, and Isoptera, and several nematode species. The chemical formula of Thu is C22H32O19N5P, and it is composed of adenosine, glucose, phosphoric acid, and gluconic diacid. In contrast to the more frequently studied insecticidal crystal protein, Thu is not a protein but a small molecule oligosaccharide. In this review, a detailed and updated description of the characteristics, structure, insecticidal mechanism, separation and purification technology, and genetic determinants of Thu is provided. PMID:25068925

  13. Evaluation of the pharmacokinetics of oral amitriptyline and its active metabolite nortriptyline in fed and fasted Greyhound dogs.

    PubMed

    Norkus, C; Rankin, D; KuKanich, B

    2015-12-01

    This study reports the pharmacokinetics of oral amitriptyline and its active metabolite nortriptyline in Greyhound dogs. Five healthy Greyhound dogs were enrolled in a randomized crossover design. A single oral dose of amitriptyline hydrochloride (actual mean dose 8.1 per kg) was administered to fasted or fed dogs. Blood samples were collected at predetermined times from 0 to 24 h after administration, and plasma drug concentrations were measured by liquid chromatography with mass spectrometry. Noncompartmental pharmacokinetic analyses were performed. Two dogs in the fasted group vomited following amitriptyline administration and were excluded from analysis. The range of amitriptyline CMAX for the remaining fasted dogs (n = 3) was 22.8-64.5 ng/mL compared to 30.6-127 ng/mL for the fed dogs (n = 5). The range of the amitriptyline AUCINF for the three fasted dogs was 167-720 h·ng/mL compared to 287-1146 h·ng/mL for fed dogs. The relative bioavailability of amitriptyline in fasted dogs compared to fed dogs was 69-91% (n = 3). The exposure of the active metabolite nortriptyline was correlated to amitriptyline exposure (R(2)  = 0.84). Due to pharmacokinetic variability and the small number of dogs completing this study, further studies are needed assessing the impact of feeding on oral amitriptyline pharmacokinetics. Amitriptyline may be more likely to cause vomiting in fasted dogs. PMID:25989225

  14. In Vitro Transformation of Chlorinated Parabens by the Liver S9 Fraction: Kinetics, Metabolite Identification, and Aryl Hydrocarbon Receptor Agonist Activity.

    PubMed

    Terasaki, Masanori; Wada, Takeshi; Nagashima, Satoshi; Makino, Masakazu; Yasukawa, Hiro

    2016-01-01

    We investigated the kinetics of in vitro transformation of a dichlorinated propyl paraben (2-propyl 3,5-dichloro-4-hydroxybenzoate; Cl2PP) by the rat liver S9 fraction and assessed the aryl hydrocarbon receptor (AhR) agonist activity of the metabolite products identified in HPLC and GC/MS analysis and by metabolite syntheses. The results indicated that the chlorination of Cl2PP reduced its degradation rate by approximately 40-fold. Two hydroxylated metabolite products showed AhR agonist activity of up to 39% of that of the parent Cl2PP when assessed in a yeast (YCM3) reporter gene assay. The determination of the metabolic properties of paraben bioaccumulation presented here provides further information on the value of risk assessments of chlorinated parabens as a means to ensure human health and environmental safety. PMID:27250800

  15. The combination of glutamate receptor antagonist MK-801 with tamoxifen and its active metabolites potentiates their antiproliferative activity in mouse melanoma K1735-M2 cells

    SciTech Connect

    Ribeiro, Mariana P.C.; Nunes-Correia, Isabel; Santos, Armanda E.; Custódio, José B.A.

    2014-02-15

    Recent reports suggest that N-methyl-D-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. In contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination. - Highlights: • MK-801 and memantine decrease melanoma cell proliferation. • The combination of MK-801 with antiestrogens inhibits melanoma cell proliferation. • These combinations greatly enhance the effects of the compounds individually. • MK-801 combined with tamoxifen active metabolites induces cell cycle arrest in G1. • The combination of MK-801 and antiestrogens is an innovative strategy for melanoma.

  16. In silico Identification of Ergosterol as a Novel Fungal Metabolite Enhancing RuBisCO Activity in Lycopersicum esculentum.

    PubMed

    Mitra, Joyeeta; Narad, Priyanka; Sengupta, Abhishek; Sharma, P D; Paul, P K

    2016-09-01

    RuBisCO (EC 4.1.1.39), a key enzyme found in stroma of chloroplast, is important for fixing atmospheric CO2 in plants. Alterations in the activity of RuBisCO could influence photosynthetic yield. Therefore, to understand the activity of the protein, knowledge about its structure is pertinent. Though the structure of Nicotiana RuBisCO has been modeled, the structure of tomato RuBisCO is still unknown. RuBisCO extracted from chloroplasts of tomato leaves was subjected to MALDI-TOF-TOF followed by Mascot Search. The protein sequence based on gene identification numbers was subjected to in silico model construction, characterization and docking studies. The primary structure analysis revealed that protein was stable, neutral, hydrophilic and has an acidic pI. The result though indicates a 90 % homology with other members of Solanaceae but differs from the structure of Arabidopsis RuBisCO. Different ligands were docked to assess the activity of RuBisCO against these metabolite components. Out of the number of modulators tested, ergosterol had the maximum affinity (E = -248.08) with RuBisCO. Ergosterol is a major cell wall component of fungi and has not been reported to be naturally found in plants. It is a known immune elicitor in plants. The current study throws light on its role in affecting RuBisCO activity in plants, thereby bringing changes in the photosynthetic rate. PMID:26253718

  17. Diabetes Mellitus Reduces Activity of Human UDP-Glucuronosyltransferase 2B7 in Liver and Kidney Leading to Decreased Formation of Mycophenolic Acid Acyl-Glucuronide Metabolite

    PubMed Central

    Dostalek, Miroslav; Court, Michael H.; Hazarika, Suwagmani

    2011-01-01

    Mycophenolic acid (MPA) is an immunosuppressive agent commonly used after organ transplantation. Altered concentrations of MPA metabolites have been reported in diabetic kidney transplant recipients, although the reason for this difference is unknown. We aimed to compare MPA biotransformation and UDP-glucuronosyltransferase (UGT) expression and activity between liver (n = 16) and kidney (n = 8) from diabetic and nondiabetic donors. Glucuronidation of MPA, as well as the expression and probe substrate activity of UGTs primarily responsible for MPA phenol glucuronide (MPAG) formation (UGT1A1 and UGT1A9), and MPA acyl glucuronide (AcMPAG) formation (UGT2B7), was characterized. We have found that both diabetic and nondiabetic human liver microsomes and kidney microsomes formed MPAG with similar efficiency; however, AcMPAG formation was significantly lower in diabetic samples. This finding is supported by markedly lower glucuronidation of the UGT2B7 probe zidovudine, UGT2B7 protein, and UGT2B7 mRNA in diabetic tissues. UGT genetic polymorphism did not explain this difference because UGT2B7*2 or *1c genotype were not associated with altered microsomal UGT2B7 protein levels or AcMPAG formation. Furthermore, mRNA expression and probe activities for UGT1A1 or UGT1A9, both forming MPAG but not AcMPAG, were comparable between diabetic and nondiabetic tissues, suggesting the effect may be specific to UGT2B7-mediated AcMPAG formation. These findings suggest that diabetes mellitus is associated with significantly reduced UGT2B7 mRNA expression, protein level, and enzymatic activity of human liver and kidney, explaining in part the relatively low circulating concentrations of AcMPAG in diabetic patients. PMID:21123165

  18. Five of 12 forms of vaccinia virus-expressed human hepatic cytochrome P450 metabolically activate aflatoxin B sub 1

    SciTech Connect

    Aoyama, Toshifumi; Yamano, Shigeru; Gelboin, H.V.; Gonzalez, F.J. ); Guzelian, P.S. )

    1990-06-01

    Twelve forms of human hepatic cytochrome P450 were expressed in hepatoma cells by means of recombinant vaccinia viruses. The expressed P450s were analyzed for their abilities to activate the potent hepatocarcinogen aflatoxin B{sub 1} to metabolites having mutagenic or DNA-binding properties. Five forms, P450s IA2, IIA3, IIB7, IIIA3, and IIIA4, activated aflatoxin B{sub 1} to mutagenic metabolites as assessed by the production of His revertants of Salmonella typhimurium in the Ames test. The same P450s catalyzed conversion of aflatoxin B{sub 1} to DNA-bound derivatives as judged by an in situ assay in which the radiolabeled carcinogen was incubated with cells expressing the individual P450 forms. Seven other human P450s, IIC8, IIC9, IID6, IIE1, IIF1, and IIIA5, and IVB1, did not significantly activate aflatoxin B{sub 1} as measured by both the Ames test and the DNA-binding assay. Moreover, polyclonal anti-rat liver P450 antibodies that crossreact with individual human P450s IA2, IIA3, IIIA3, and IIIA4 each inhibited aflatoxin B{sub 1} activation catalyzed by human liver S-9 extracts. Inhibition ranged from as low as 10% with antibody against IIA3 to as high as 65% with antibody against IIIA3 and IIIA4. These results establish that metabolic activation of aflatoxin B{sub 1} in human liver involves the contribution of multiple forms of P450.

  19. The active metabolite of prasugrel inhibits ADP-stimulated thrombo-inflammatory markers of platelet activation: Influence of other blood cells, calcium, and aspirin.

    PubMed

    Frelinger, Andrew L; Jakubowski, Joseph A; Li, Youfu; Barnard, Marc R; Fox, Marsha L; Linden, Matthew D; Sugidachi, Atsuhiro; Winters, Kenneth J; Furman, Mark I; Michelson, Alan D

    2007-07-01

    The novel thienopyridine prodrug prasugrel, a platelet P2Y(12) ADP receptor antagonist, requires in vivo metabolism for activity. Although pharmacological data have been collected on the effects of prasugrel on platelet aggregation, there are few data on the direct effects of the prasugrel's active metabolite, R-138727, on other aspects of platelet function. Here we examined the effects of R-138727 on thrombo-inflammatory markers of platelet activation, and the possible modulatory effects of other blood cells, calcium, and aspirin. Blood (PPACK or citrate anticoagulated) from healthy donors pre- and post-aspirin was incubated with R-138727 and the response to ADP assessed in whole blood or platelet-rich plasma (PRP) by aggregometry and flow cytometric analysis of leukocyte-platelet aggregates, platelet surface P-selectin, and GPIIb-IIIa activation. Low-micromolar concentrations of R-138727 resulted in a rapid and consistent inhibition of these ADP-stimulated thrombo-inflammatory markers. These rapid kinetics required physiological calcium levels, but were largely unaffected by aspirin. Lower IC(50) values in whole blood relative to PRP suggested that other blood cells affect ADP-induced platelet activation and hence the net inhibition by R-138727. R-138727 did not inhibit P2Y(12)-mediated ADP-induced shape change, even at concentrations that completely inhibited platelet aggregation, confirming the specificity of R-138727 for P2Y(12). In conclusion, R-138727, the active metabolite of prasugrel, results in rapid, potent, consistent, and selective inhibition of P2Y(12)-mediated up-regulation of thrombo-inflammatory markers of platelet activation. This inhibition is enhanced in the presence other blood cells and calcium, but not aspirin. PMID:17598013

  20. PreQ0 base, an unusual metabolite with anti-cancer activity from Streptomyces qinglanensis 172205.

    PubMed

    Xu, Dongbo; Ma, Min; Liu, Yongfeng; Zhou, Ting; Wang, Kexin; Deng, Zixin; Hong, Kui

    2015-01-01

    PreQ0 base (7-cyano-7-deazaguanine, compound 1) is the biosynthetic precursor of queuosine-tRNA and important synthetic intermediate for bioactive compounds. It was obtained for the first time as a new natural product from a mangrove actinomycete Streptomyces qinglanensis 172205, during the course of searching for anti-cancer compounds from marine microbes. PreQ0 base showed anti-HeLa (IC50 = 62.0 μg/ml) and anti-HepG2 (IC50 = 80.6 μg/ml) activities, higher cytotoxicity than the positive control, fluorouracil. Furthermore, it exhibited weak α -glucosidase inhibitory activity, but no obvious antimicrobial and Aβ1-42 fibrillation inhibitory activities. In silico analysis of the genome of the strain 172205 revealed a putative biosynthetic gene cluster directing the biosynthesis of PreQ0 base. The gene cluster only contained three Open Reading Frames (ORFs), queC, queD and queE. The absence of the key gene queF encoding 7-cyano-7-deazaguanine reductase catalyzing PreQ0 base to PreQ1 base suggested that the strain only has the capacity of accumulation of PreQ0 base as a metabolite, consistent with our observation in chemical identification. PMID:25353335

  1. Activation of p53 with Ilimaquinone and Ethylsmenoquinone, Marine Sponge Metabolites, Induces Apoptosis and Autophagy in Colon Cancer Cells

    PubMed Central

    Lee, Hyun-Young; Chung, Kyu Jin; Hwang, In Hyun; Gwak, Jungsuk; Park, Seoyoung; Ju, Bong Gun; Yun, Eunju; Kim, Dong-Eun; Chung, Young-Hwa; Na, MinKyun; Song, Gyu-Yong; Oh, Sangtaek

    2015-01-01

    The tumor suppressor, p53, plays an essential role in the cellular response to stress through regulating the expression of genes involved in cell cycle arrest, apoptosis and autophagy. Here, we used a cell-based reporter system for the detection of p53 response transcription to identify the marine sponge metabolites, ilimaquinone and ethylsmenoquinone, as activators of the p53 pathway. We demonstrated that ilimaquinone and ethylsmenoquinone efficiently stabilize the p53 protein through promotion of p53 phosphorylation at Ser15 in both HCT116 and RKO colon cancer cells. Moreover, both compounds upregulate the expression of p21WAF1/CIP1, a p53-dependent gene, and suppress proliferation of colon cancer cells. In addition, ilimaquinone and ethylsmenoquinone induced G2/M cell cycle arrest and increased caspase-3 cleavage and the population of cells that positively stained with Annexin V-FITC, both of which are typical biochemical markers of apoptosis. Furthermore, autophagy was elicited by both compounds, as indicated by microtubule-associated protein 1 light chain 3 (LC3) puncta formations and LC3-II turnover in HCT116 cells. Our findings suggest that ilimaquinone and ethylsmenoquinone exert their anti-cancer activity by activation of the p53 pathway and may have significant potential as chemo-preventive and therapeutic agents for human colon cancer. PMID:25603347

  2. Activated and unactivated forms of human erythrocyte aldose reductase.

    PubMed Central

    Srivastava, S K; Hair, G A; Das, B

    1985-01-01

    Aldose reductase (alditol:NADP+ 1-oxidoreductase, EC 1.1.1.21) has been partially purified from human erythrocytes by DEAE-cellulose (DE-52) column chromatography. This enzyme is activated severalfold upon incubation with 10 microM each glucose 6-phosphate, NADPH, and glucose. The activation of the enzyme was confirmed by following the oxidation of NADPH as well as the formation of sorbitol with glucose as substrate. The activated form of aldose reductase exhibited monophasic kinetics with both glyceraldehyde and glucose (Km of glucose = 0.68 mM and Km of glyceraldehyde = 0.096 mM), whereas the native (unactivated) enzyme exhibited biphasic kinetics (Km of glucose = 9.0 and 0.9 mM and Km of glyceraldehyde = 1.1 and 0.14 mM). The unactivated enzyme was strongly inhibited by aldose reductase inhibitors such as sorbinil, alrestatin, and quercetrin, and by phosphorylated intermediates such as ADP, glycerate 3-phosphate, glycerate 1,3-bisphosphate, and glycerate 2,3-trisphosphate. The activated form of the enzyme was less susceptible to inhibition by aldose reductase inhibitors and phosphorylated intermediates. PMID:3933003

  3. Microbial transformation of ginsenoside-Rg₁ by Absidia coerulea and the reversal activity of the metabolites towards multi-drug resistant tumor cells.

    PubMed

    Liu, Xin; Qiao, Lirui; Xie, Dan; Zhang, Yi; Zou, Jianhua; Chen, Xiaoguang; Dai, Jungui

    2011-12-01

    Biotransformation of ginsenoside-Rg₁ (1) by the fungus Absidia coerulea AS 3.2462 yielded five metabolites (2-6). On the basis of spectroscopic data analyses, the metabolites were identified as ginsenoside-F₁ (2), 6α,12β-dihydroxydammar-3-one-20(S)-O-β-D-glucopyranoside (3), 3-oxo-20(S)-protopanaxatriol (4), 3-oxo-7β-hydroxy-20(S)-protopanaxatriol (5), and 3-oxo-7β,15α-dihydroxy-20(S)-protopanaxatriol (6), respectively. Among them, 5 and 6 are new compounds. These results indicated that Absidia coerulea AS 3.2462 could catalyze the specific C-3 dehydrogenation of derivatives of ginsenoside-Rg₁, as well as hydroxylation at the 7β and 15α positions. Metabolites 2, 4 and 5 exhibited moderate reversal activity towards A549/taxol MDR tumor cells in vitro. PMID:21946057

  4. Effects of licochalcon A on the pharmacokinetics of losartan and its active metabolite, EXP-3174, in rats.

    PubMed

    Choi, J S; Choi, J S; Choi, D H

    2013-11-01

    Losartan and licochalcon A interact with cytochrome P-450 (CYP) enzymes and P-glycoprotein (P-gp), and the increase in the use of health supplements may result in licochalcon A being taken concomitantly with losartan to treat or prevent cardiovascular diseases as a combination therapy. The effect of licochalcon A, a natural flavonoid, on the pharmacokinetics of losartan and its active metabolite, EXP-3174, was investigated in rats. Pharmacokinetic parameters of losartan and EXP-3174 were determined after oral administration of losartan (9 mg/kg) to rats in the presence or absence of licochalcon A (0.5, 2.5 and 10 mg/kg). The effect of licochalcon A on P-glycoprotein (P-gp) as well as CYP3A4 and 2C9 activities was also evaluated. Licochalcon A inhibited CYP3A4 and CYP2C9 enzyme activities with 50% inhibition concentrations (IC50) of 2.0 and 0.1 microM, respectively. In addition, licochalcon A significantly enhanced the cellular accumulation of rhodamine-123 in a concentration-dependent manner in MCF-7/ADR cells overexpressing P-gp. The pharmacokinetic parameters of losartan were significantly altered by licochalcon A. Licochalcon A (2.5 mg/kg or 10 mg/kg) increased AUC0-infinity of losartan by 33.4-63.2% and Cmax of losartan by 34.0-62.8%. The total body clearance (CL/F) was significantly decreased (2.5 mg/kg, p < 0.05; 10 mg/kg, p < 0.01) by licochalcon A. Consequently, the absolute bioavailability of losartan in the presence of licochalcon A increased significantly (2.5 mg/kg, p < 0.05; 10 mg/kg, p < 0.01) compared to that in the control group. The relative bioavailability (R.B.) of losartan was 1.15- to 1.63-fold greater than that of the control group. However, there was no significant change in Tmax and t1/2 of losartan in the presence of licochalcon A. Licochalcon A (10 mg/kg) increased the AUC0-infinity of EXP-3174 but this was not significant. Furthermore, concurrent use of licochalcon A (10 mg/kg) significantly decreased the metabolite-parent AUC ratio (M

  5. The combination of glutamate receptor antagonist MK-801 with tamoxifen and its active metabolites potentiates their antiproliferative activity in mouse melanoma K1735-M2 cells.

    PubMed

    Ribeiro, Mariana P C; Nunes-Correia, Isabel; Santos, Armanda E; Custódio, José B A

    2014-02-15

    Recent reports suggest that N-methyl-d-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. In contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination. PMID:24240127

  6. Antioxidant activity and metabolite profile of quercetion in vitamin E depleted rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary antioxidants interact in a dynamic fashion, including recycling and sparing one another, to decrease oxidative stress. Limited information is available regarding the interrelationships in vivo between quercetin and vitamin E. We investigated the antioxidant activity and metabolism of querc...

  7. Structure-dependent activities of polybrominated diphenyl ethers and hydroxylated metabolites on zebrafish retinoic acid receptor.

    PubMed

    Zhao, Jing; Zhu, Xiangwei; Xu, Ting; Yin, Daqiang

    2015-02-01

    Polybrominated diphenyl ethers (PBDEs), a group of potential endocrine-disrupting chemicals (EDCs) have been shown to disrupt retinoid homeostasis in different species in both laboratory and field studies. However, the molecular mechanisms of interactions with the retinoic acid receptor (RAR) are not fully understood. Zebrafish have proven useful for investigating mechanisms of chemical toxicity. In the present study, a reporter gene assay was used to investigate the activities of 11 PBDEs and six OH-PBDEs with different degrees of bromination on zebrafish RAR. All tested OH-PBDEs induced RAR transcriptional activity; however, of the 11 PBDEs examined, only BDE28 and BDE154 affected the RAR transcriptional activity. Homology modeling and molecular docking were employed to simulate the interactions of PBDEs/OH-PBDEs with zebrafish RARs and to identify binding affinities to analyze the specialization of the interaction between RARs and PBDEs/OH-PBDEs. The results showed that although these compounds could bind with RARs, the effects of PBDEs/OH-PBDEs on RAR transcriptional activity did not depend on their RAR-binding abilities. The present study is the first attempt to demonstrate that OH-PBDEs could induce RAR transcriptional activity by binding directly with RAR; these effects are possibly related to the structure of the compounds, especially their hydroxylation and bromination. Most of the PBDEs could not directly interact with the RAR. PMID:25077655

  8. Prostaglandin D2 metabolites as a biomarker of in vivo mast cell activation in systemic mastocytosis and rheumatoid arthritis.

    PubMed

    Cho, Catherine; Nguyen, Anna; Bryant, Katherine J; O'Neill, Sean G; McNeil, H Patrick

    2016-03-01

    Mast cells (MCs) participate in diseases such as systemic mastocytosis (SM) and allergic conditions. Less well understood is the role of MCs in non-allergic inflammatory disorders like rheumatoid arthritis (RA). Studying definitive roles for MCs in human diseases has been hampered by the lack of a well-accepted biomarker for monitoring in vivo MC activation. This study aimed to investigate the utility of urinary tetranor PGDM (T-PGDM) as a biomarker of in vivo MC activation in patients with SM, and apply this biomarker to assess MC involvement in relation to RA disease activity. A prospective, cross-sectional cohort study was conducted to measure a major urinary metabolite of prostaglandin D2, T-PGDM. Urine samples were collected from patients with RA (n = 60), SM (n = 17) and healthy normal controls (n = 16) and T-PGDM excretion was determined by enzyme immunoassay as nanograms per milligram of urinary creatinine (ng/mg Cr). Mean urinary T-PGDM excretion was significantly higher (p < 0.01) in patients with SM compared to controls (37.2 vs. 11.5 ng/mg Cr) with 65% of SM patients showing elevated levels. One third of patients with RA had elevated T-PGDM excretion, and the mean level in the RA group (20.0 ng/mg Cr) was significantly higher than controls (p < 0.01). Medications inhibiting cyclooxygenase reduced T-PGDM excretion. Urinary T-PGDM excretion appears promising as a biomarker of in vivo MC activity and elevated levels in 33% of patients with RA provides evidence of MC activation in this disease. PMID:27042302

  9. 2-Methoxyestradiol, an endogenous 17β-estradiol metabolite, inhibits microglial proliferation and activation via an estrogen receptor-independent mechanism.

    PubMed

    Schaufelberger, Sara A; Rosselli, Marinella; Barchiesi, Federica; Gillespie, Delbert G; Jackson, Edwin K; Dubey, Raghvendra K

    2016-03-01

    17β-Estradiol (estradiol) inhibits microglia proliferation. 2-Methoxyestradiol (2-ME) is an endogenous metabolite of estradiol with little affinity for estrogen receptors (ERs). We hypothesize that 2-ME inhibits microglial proliferation and activation and contributes to estradiol's inhibitory effects on microglia. We compared the effects of estradiol, 2-hydroxyestradiol [2-OE; estradiol metabolite produced by cytochrome P450 (CYP450)], and 2-ME [formed by catechol-O-methyltransferase (COMT) acting upon 2-OE] on microglial (BV2 cells) DNA synthesis, cell proliferation, activation, and phagocytosis. 2-ME and 2-OE were approximately three- and 10-fold, respectively, more potent than estradiol in inhibiting microglia DNA synthesis. The antimitogenic effects of estradiol were reduced by pharmacological inhibitors of CYP450 and COMT. Inhibition of COMT blocked the conversion of 2-OE to 2-ME and the antimitogenic effects of 2-OE but not 2-ME. Microglia expressed ERβ and GPR30 but not ERα. 2,3-Bis(4-hydroxyphenyl)-propionitrile (ERβ agonist), but not 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (ERα agonist) or G1 (GPR30 agonist), inhibited microglial proliferation. The antiproliferative effects of estradiol, but not 2-OE or 2-ME, were partially reversed by ICI-182,780 (ERα/β antagonist) but not by 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole (ERα antagonist) or G15 (GPR30 antagonist). Lipopolysaccharide increased microglia iNOS and COX-2 expression and phagocytosing activity of microglia; these effects were inhibited by 2-ME. We conclude that in microglia, 2-ME inhibits proliferation, proinflammatory responses, and phagocytosis. 2-ME partially mediates the effects of estradiol via ER-independent mechanisms involving sequential metabolism of estradiol to 2-OE and 2-ME. 2-ME could be of potential therapeutic use in postischemic stroke injuries. Interindividual differences in estradiol metabolism might affect the

  10. Fumigaclavine C, an fungal metabolite, improves experimental colitis in mice via downregulating Th1 cytokine production and matrix metalloproteinase activity.

    PubMed

    Wu, Xue-Feng; Fei, Ming-Jian; Shu, Ren-Geng; Tan, Ren-Xiang; Xu, Qiang

    2005-09-01

    In the present paper, the effect of Fumigaclavine C, a fungal metabolite, on experimental colitis was examined. Fumigaclavine C, when administered intraperitoneally once a day, significantly reduced the weight loss and mortality rate of mice with experimental colitis induced by intrarectally injection of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). This compound also markedly alleviated the macroscopic and microscopic appearances of colitis. Furthermore, Fumigaclavine C, given both in vivo and in vitro, showed a marked inhibition on the expression of several inflammatory cytokines, including IL-1beta, IL-2, IL-12alpha, IFN-gamma, TNF-alpha as well as MMP-9 in sacral lymph node cells, colonic patch lymphocytes and colitis tissues from the TNBS colitis mice. Meanwhile, the compound caused a dose-dependent reduction in IL-2 and IFN-gamma from the lymphocytes at the protein level and MMP-9 activity. These results suggest that Fumigaclavine C may alleviate experimental colitis mainly via down-regulating the production of Th1 cytokines and the activity of matrix metalloproteinase. PMID:16023606

  11. Effects of Metabolites Produced from (-)-Epigallocatechin Gallate by Rat Intestinal Bacteria on Angiotensin I-Converting Enzyme Activity and Blood Pressure in Spontaneously Hypertensive Rats.

    PubMed

    Takagaki, Akiko; Nanjo, Fumio

    2015-09-23

    Inhibitory activity of angiotensin I-converting enzyme (ACE) was examined with (-)-epigallocatechin gallate (EGCG) metabolites produced by intestinal bacteria, together with tea catechins. All of the metabolites showed ACE inhibitory activities and the order of IC50 was hydroxyphenyl valeric acids > 5-(3,4,5-trihydroxyphenyl)-γ-valerolactone (1) > trihydroxyphenyl 4-hydroxyvaleric acid ≫ dihydroxyphenyl 4-hydroxyvaleric acid ≫ 5-(3,5-dihydroxyphenyl)-γ-valerolactone (2). Among the catechins, galloylated catechins exhibited stronger ACE inhibitory activity than nongalloylated catechins. Furthermore, the effects of a single oral intake of metabolites 1 and 2 on systolic blood pressure (SBP) were examined with spontaneously hypertensive rats (SHR). Significant decreases in SBP were observed between 2 h after oral administration of 1 (150 mg/kg in SHR) and the control group (p = 0.002) and between 4 h after administration of 2 (200 mg/kg in SHR) and the control group (p = 0.044). These results suggest that the two metabolites have hypotensive effects in vivo. PMID:26323573

  12. Structure of neprilysin in complex with the active metabolite of sacubitril

    PubMed Central

    Schiering, Nikolaus; D’Arcy, Allan; Villard, Frederic; Ramage, Paul; Logel, Claude; Cumin, Frederic; Ksander, Gary M.; Wiesmann, Christian; Karki, Rajeshri G.; Mogi, Muneto

    2016-01-01

    Sacubitril is an ethyl ester prodrug of LBQ657, the active neprilysin (NEP) inhibitor, and a component of LCZ696 (sacubitril/valsartan). We report herein the three-dimensional structure of LBQ657 in complex with human NEP at 2 Å resolution. The crystal structure unravels the binding mode of the compound occupying the S1, S1’ and S2’ sub-pockets of the active site, consistent with a competitive inhibition mode. An induced fit conformational change upon binding of the P1’-biphenyl moiety of the inhibitor suggests an explanation for its selectivity against structurally homologous zinc metallopeptidases. PMID:27302413

  13. Structure of neprilysin in complex with the active metabolite of sacubitril.

    PubMed

    Schiering, Nikolaus; D'Arcy, Allan; Villard, Frederic; Ramage, Paul; Logel, Claude; Cumin, Frederic; Ksander, Gary M; Wiesmann, Christian; Karki, Rajeshri G; Mogi, Muneto

    2016-01-01

    Sacubitril is an ethyl ester prodrug of LBQ657, the active neprilysin (NEP) inhibitor, and a component of LCZ696 (sacubitril/valsartan). We report herein the three-dimensional structure of LBQ657 in complex with human NEP at 2 Å resolution. The crystal structure unravels the binding mode of the compound occupying the S1, S1' and S2' sub-pockets of the active site, consistent with a competitive inhibition mode. An induced fit conformational change upon binding of the P1'-biphenyl moiety of the inhibitor suggests an explanation for its selectivity against structurally homologous zinc metallopeptidases. PMID:27302413

  14. NUCLEAR ACTIVITY IS MORE PREVALENT IN STAR-FORMING GALAXIES

    SciTech Connect

    Rosario, D. J.; Lutz, D.; Berta, S.; Popesso, P.; Genzel, R.; Saintonge, A.; Tacconi, L.; Wuyts, S. E-mail: lutz@mpe.mpg.de E-mail: popesso@mpe.mpg.de E-mail: amelie@mpe.mpg.de E-mail: swuyts@mpe.mpg.de; and others

    2013-07-01

    We explore the question of whether low and moderate luminosity active galactic nuclei (AGNs) are preferentially found in galaxies that are undergoing a transition from active star formation (SF) to quiescence. This notion has been suggested by studies of the UV-optical colors of AGN hosts, which find them to be common among galaxies in the so-called Green Valley, a region of galaxy color space believed to be composed mostly of galaxies undergoing SF quenching. Combining the deepest current X-ray and Herschel/PACS far-infrared (FIR) observations of the two Chandra Deep Fields with redshifts, stellar masses, and rest-frame photometry derived from the extensive and uniform multi-wavelength data in these fields, we compare the rest-frame U - V color distributions and star formation rate distributions of AGNs and carefully constructed samples of inactive control galaxies. The UV-to-optical colors of AGNs are consistent with equally massive inactive galaxies at redshifts out to z {approx} 2, but we show that such colors are poor tracers of SF. While the FIR distributions of both star-forming AGNs and star-forming inactive galaxies are statistically similar, we show that AGNs are preferentially found in star-forming host galaxies, or, in other words, AGNs are less likely to be found in weakly star-forming or quenched galaxies. We postulate that, among X-ray-selected AGNs of low and moderate accretion luminosities, the supply of cold gas primarily determines the accretion rate distribution of the nuclear black holes.

  15. Cytotoxic activities of ethyl acetate extract and a metabolite from a Monocillium species.

    PubMed

    Khondkar, Proma; Rahman, M Mukhlesur; Islam, Anwarul

    2005-09-01

    The ethyl acetate soluble fraction of a cultural broth of a Monocillium species afforded the isolation of 5-hydroxymethylfurfural. Both the extract and 5-hydroxymethylfurfural showed significant cytotoxic activities in a brine shrimp bioassay and the LC(50) values were found to be 14.96 microg/mL and 23.71 microg/mL, respectively. PMID:16220580

  16. Total synthesis of the cyanobacterial metabolite nostodione A: discovery of its antiparasitic activity against Toxoplasma gondii.

    PubMed

    McNulty, J; Keskar, K; Bordón, C; Yolken, R; Jones-Brando, L

    2014-08-18

    A total synthesis of the cyanobacterial natural product nostodione A is reported involving a convergent, diversity-oriented route. A small assemblage of structural analogues were prepared and their cytotoxicity and anti-invasion activity against the protozoal parasite Toxoplasma gondii is reported for the first time. PMID:24970332

  17. Salicylate, diflunisal and their metabolites inhibit CBP/p300 and exhibit anticancer activity

    PubMed Central

    Shirakawa, Kotaro; Wang, Lan; Man, Na; Maksimoska, Jasna; Sorum, Alexander W; Lim, Hyung W; Lee, Intelly S; Shimazu, Tadahiro; Newman, John C; Schröder, Sebastian; Ott, Melanie; Marmorstein, Ronen; Meier, Jordan; Nimer, Stephen; Verdin, Eric

    2016-01-01

    Salicylate and acetylsalicylic acid are potent and widely used anti-inflammatory drugs. They are thought to exert their therapeutic effects through multiple mechanisms, including the inhibition of cyclo-oxygenases, modulation of NF-κB activity, and direct activation of AMPK. However, the full spectrum of their activities is incompletely understood. Here we show that salicylate specifically inhibits CBP and p300 lysine acetyltransferase activity in vitro by direct competition with acetyl-Coenzyme A at the catalytic site. We used a chemical structure-similarity search to identify another anti-inflammatory drug, diflunisal, that inhibits p300 more potently than salicylate. At concentrations attainable in human plasma after oral administration, both salicylate and diflunisal blocked the acetylation of lysine residues on histone and non-histone proteins in cells. Finally, we found that diflunisal suppressed the growth of p300-dependent leukemia cell lines expressing AML1-ETO fusion protein in vitro and in vivo. These results highlight a novel epigenetic regulatory mechanism of action for salicylate and derivative drugs. DOI: http://dx.doi.org/10.7554/eLife.11156.001 PMID:27244239

  18. Salicylate, diflunisal and their metabolites inhibit CBP/p300 and exhibit anticancer activity.

    PubMed

    Shirakawa, Kotaro; Wang, Lan; Man, Na; Maksimoska, Jasna; Sorum, Alexander W; Lim, Hyung W; Lee, Intelly S; Shimazu, Tadahiro; Newman, John C; Schröder, Sebastian; Ott, Melanie; Marmorstein, Ronen; Meier, Jordan; Nimer, Stephen; Verdin, Eric

    2016-01-01

    Salicylate and acetylsalicylic acid are potent and widely used anti-inflammatory drugs. They are thought to exert their therapeutic effects through multiple mechanisms, including the inhibition of cyclo-oxygenases, modulation of NF-κB activity, and direct activation of AMPK. However, the full spectrum of their activities is incompletely understood. Here we show that salicylate specifically inhibits CBP and p300 lysine acetyltransferase activity in vitro by direct competition with acetyl-Coenzyme A at the catalytic site. We used a chemical structure-similarity search to identify another anti-inflammatory drug, diflunisal, that inhibits p300 more potently than salicylate. At concentrations attainable in human plasma after oral administration, both salicylate and diflunisal blocked the acetylation of lysine residues on histone and non-histone proteins in cells. Finally, we found that diflunisal suppressed the growth of p300-dependent leukemia cell lines expressing AML1-ETO fusion protein in vitro and in vivo. These results highlight a novel epigenetic regulatory mechanism of action for salicylate and derivative drugs. PMID:27244239

  19. In vitro biological activity of secondary metabolites from Seseli rigidum Waldst. et Kit. (Apiaceae).

    PubMed

    Jakovljević, Dragana; Vasić, Sava; Stanković, Milan; Čomić, Ljiljana; Topuzović, Marina

    2015-12-01

    The antioxidant, antimicrobial activity, total phenolic content and flavonoid concentration of Seseli rigidum Waldst. et Kit. were evaluated. Five different extracts of the aboveground plant parts were obtained by extraction with distilled water, methanol, acetone, ethyl acetate and petroleum ether. Total phenols were determined using the Folin-Ciocalteu's reagent, with the highest values obtained in the acetone extract (102.13 mg GAE/g). The concentration of flavonoids, determined by using a spectrophotometric method with aluminum chloride and expressed in terms of rutin equivalent, was also highest in the acetone extracts (291.58 mg RUE/g). The antioxidant activity was determined in vitro using DPPH reagent. The greatest antioxidant activity was expressed in the aqueous extract (46.15 μg/ml). In vitro antimicrobial activities were determined using a microdilution analysis method; minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) were determined. Methanolic extract had the greatest influence on bacilli (MIC at 0.0391 mg/ml), but the best antimicrobial effect had acetone and ethyl acetate extracts considering their broad impact on bacteria. According to our research, S. rigidum can be regarded as promising candidate for natural plant source with high value of biological compounds. PMID:26616372

  20. Antioxidant and anti-acetylcholinesterase activities of extracts and secondary metabolites from Acacia cyanophylla

    PubMed Central

    Ghribia, Lotfi; Ghouilaa, Hatem; Omrib, Amel; Besbesb, Malek; Janneta, Hichem Ben

    2014-01-01

    Objective To investigate the antioxidant potential and anti-acetycholinesterase activity of compounds and extracts from Acacia cyanophylla (A. cyanophylla). Methods Three polyphenolic compounds were isolated from ethyl acetate extract of A. cyanophylla flowers. They have been identified as isosalipurposide 1, quercetin 2 and naringenin 3. Their structures were elucidated by extensive spectroscopic methods including 1D and 2D NMR experiments as well as ES-MS. The prepared extracts and the isolated compounds 1-3 were tested for their antioxidant activity using 1′-1′-diphenylpicrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging assays and reducing power. They have been also investigated for inhibitory effect against acetylcholinesterase using the microplate assay. Results In the DPPH test, the EtOAc extract of flowers exhibited the highest antioxidant effect (67.26 µg/mL). Isosalipurposide 1 showed a significant antiradical power against DPPH (81.9 µg/mL). All extracts showed a dose-dependent acetylcholinesterase inhibition. In terms of the IC50 value, the butanolic extract (16.03 µg/mL) was the most potent sample. Isosalipurposide 1 was found to be active against AChE with an IC50 value of 52.04 µg/mL. Conclusions The results demonstrated the important antioxidant and anti-acetylcholinesterase activity of pure compounds and extracts from A. cyanophylla. PMID:25183120

  1. Non-invasive monitoring of adrenocortical activity in captive African Penguin (Spheniscus demersus) by measuring faecal glucocorticoid metabolites.

    PubMed

    Ozella, L; Anfossi, L; Di Nardo, F; Pessani, D

    2015-12-01

    Measurement of faecal glucocorticoid metabolites (FGMs) has become a useful and widely-accepted method for the non-invasive evaluation of stress in vertebrates. In this study we assessed the adrenocortical activity of five captive African Penguins (Spheniscus demersus) by means of FGM evaluation following a biological stressor, i.e. capture and immobilization. In addition, we detected individual differences in secretion of FGMs during a stage of the normal biological cycle of penguins, namely the breeding period, without any external or induced causes of stress. Our results showed that FGM concentrations peaked 5.5-8h after the induced stress in all birds, and significantly decreased within 30 h. As predictable, the highest peak of FGMs (6591 ng/g) was reached by the youngest penguin, which was at its first experience with the stressor. This peak was 1.8-2.7-fold higher compared to those of the other animals habituated to the stimulus. For the breeding period, our results revealed that the increase in FGMs compared to ordinary levels, and the peaks of FGMs, varied widely depending on the age and mainly on the reproductive state of the animal. The bird which showed the lowest peak (2518 ng/g) was an old male that was not in a reproductive state at the time of the study. Higher FGM increases and peaks were reached by the two birds which were brooding (male: 5552%, 96,631 ng/g; female: 1438%, 22,846 ng/g) and by the youngest bird (1582%, 39,700 ng/g). The impact of the reproductive state on FGM levels was unexpected compared to that produced by the induced stress. The EIA used in this study to measure FGM levels proved to be a reliable tool for assessing individual and biologically-relevant changes in FGM concentrations in African Penguin. Moreover, this method allowed detection of physiological stress during the breeding period, and identification of individual differences in relation to the reproductive status. The increase in FGM levels as a response to capture and

  2. Secondary metabolites from Vietnamese marine invertebrates with activity against Trypanosoma brucei and T. cruzi.

    PubMed

    Thao, Nguyen Phuong; No, Joo Hwan; Luyen, Bui Thi Thuy; Yang, Gyongseon; Byun, Soo Young; Goo, Junghyun; Kim, Kyung Tae; Cuong, Nguyen Xuan; Nam, Nguyen Hoai; Van Minh, Chau; Schmidt, Thomas J; Kang, Jong Seong; Kim, Young Ho

    2014-01-01

    Marine-derived natural products from invertebrates comprise an extremely diverse and promising source of the compounds from a wide variety of structural classes. This study describes the discovery of five marine natural products with activity against Trypanosoma species by natural product library screening using whole cell in vitro assays. We investigated the anti-trypanosomal activity of the extracts from the soft corals and echinoderms living in Vietnamese seas. Of the samples screened, the methanolic extracts of several marine organisms exhibited potent activities against cultures of Trypanosoma brucei and T. cruzi (EC50 < 5.0 μg/mL). Among the compounds isolated from these extracts, laevigatol B (1) from Lobophytum crassum and L. laevigatum, (24S)-ergost-4-ene-3-one (2) from Sinularia dissecta, astropectenol A (3) from Astropecten polyacanthus, and cholest-8-ene-3β,5α,6β,7α-tetraol (4) from Diadema savignyi showed inhibitory activity against T. brucei with EC50 values ranging from 1.57 ± 0.14 to 14.6 ± 1.36 μM, relative to the positive control, pentamidine (EC50 = 0.015 ± 0.003 μM). Laevigatol B (1) and 5α-cholest-8(14)-ene-3β,7α-diol (5) exhibited also significant inhibitory effects on T. cruzi. The cytotoxic activity of the pure compounds on mammalian cells was also assessed and found to be insignificant in all cases. This is the first report on the inhibitory effects of marine organisms collected in Vietnamese seas against Trypanosoma species responsible for neglected tropical diseases. PMID:24962391

  3. 76 FR 25364 - Agency Information Collection Activities: Form I-864, Form I-864A, Form I-864EZ, and From I-864W...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form I-864, Form I- 864A, Form I-864EZ, and From I-864W; Extension of an Existing Information Collection; Comment Request. ACTION: 60-Day Notice of Information Collection Under Review; Form I- 864, Affidavit of...

  4. Secondary metabolites from the unripe pulp of Persea americana and their antimycobacterial activities.

    PubMed

    Lu, Ying-Chen; Chang, Hsun-Shuo; Peng, Chien-Fang; Lin, Chu-Hung; Chen, Ih-Sheng

    2012-12-15

    The fruits of Persea americana (Avocado) are nowadays used as healthy fruits in the world. Bioassay-guided fractionation of the active ethyl acetate soluble fraction has led to the isolation of five new fatty alcohol derivatives, avocadenols A-D (1-4) and avocadoin (5) from the unripe pulp of P. americana, along with 12 known compounds (6-17). These structures were elucidated by spectroscopic analysis. Among the isolates, avocadenol A (1), avocadenol B (2), (2R,4R)-1,2,4-trihydroxynonadecane (6), and (2R,4R)-1,2,4-trihydroxyheptadec-16-ene (7) showed antimycobacterial activity against Mycobacterium tuberculosis H(37)R(V)in vitro, with MIC values of 24.0, 33.8, 24.9, and 35.7 μg/ml, respectively. PMID:22980888

  5. The Effect of the Lunar Cycle on Fecal Cortisol Metabolite Levels and Foraging Ecology of Nocturnally and Diurnally Active Spiny Mice

    PubMed Central

    Dayan, Tamar; Kronfeld-Schor, Noga

    2011-01-01

    We studied stress hormones and foraging of nocturnal Acomys cahirinus and diurnal A. russatus in field populations as well as in two field enclosures populated by both species and two field enclosures with individuals of A. russatus alone. When alone, A. russatus individuals become also nocturnally active. We asked whether nocturnally active A. russatus will respond to moon phase and whether this response will be obtained also in diurnally active individuals. We studied giving-up densities (GUDs) in artificial foraging patches and fecal cortisol metabolite levels. Both species exhibited elevated fecal cortisol metabolite levels and foraged to higher GUDs in full moon nights; thus A. russatus retains physiological response and behavioral patterns that correlate with full moon conditions, as can be expected in nocturnal rodents, in spite of its diurnal activity. The endocrinological and behavioral response of this diurnal species to moon phase reflects its evolutionary heritage. PMID:21829733

  6. Secondary metabolites of Seseli rigidum: Chemical composition plus antioxidant, antimicrobial and cholinesterase inhibition activity.

    PubMed

    Stankov-Jovanović, V P; Ilić, M D; Mitić, V D; Mihajilov-Krstev, T M; Simonović, S R; Nikolić Mandić, S D; Tabet, J C; Cole, R B

    2015-01-01

    Extracts of different polarity obtained from various plant parts (root, leaf, flower and fruit) of Seseli rigidum were studied by different antioxidant assays: DPPH and ABTS radical scavenging activity, by total reducing power method as well as via total content of flavonoids and polyphenols. Essential oils of all plant parts showed weak antioxidant characteristics. The inhibitory concentration range of the tested extracts, against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and fungi Candida albicans and Aspergillus niger was 0.01-1.50 mg/mL and of a microbicidal 0.02-3.00 mg/mL. In the interaction with cholinesterase, all essential oils proved effective as inhibitors. The highest percentage of inhibition versus human and horse cholinesterase was shown by root essential oil (38.20% and 48.30%, respectively) among oils, and root hexane extract (40.56% and 50.65% respectively). Essential oils and volatile components of all plant parts were identified by GC, GC-MS and headspace/GC-MS. Statistical analysis of the ensemble of results showed that the root essential oil composition differed significantly from essential oils of other parts of the plant. Taking into account all of the studied activities, the root hexane extract showed the best overall properties. By means of high performance liquid chromatography coupled to high resolution mass spectrometry, the 30 most abundant constituents were identified in extracts of different polarity. The presence of identified constituents was linked to observed specific biological activities, thus designating compounds potentially responsible for each exhibited activity. PMID:25863020

  7. Complex secondary metabolites from Ludwigia leptocarpa with potent antibacterial and antioxidant activities.

    PubMed

    Mabou, Florence Déclaire; Tamokou, Jean-de-Dieu; Ngnokam, David; Voutquenne-Nazabadioko, Laurence; Kuiate, Jules-Roger; Bag, Prasanta Kumar

    2016-01-01

    Diarrhea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. The aim of the present study was to evaluate the antibacterial and antioxidant activities of extracts and compounds from Ludwigia leptocarpa, a plant traditionally used for its vermifugal, anti-dysenteric, and antimicrobial properties. A methanol extract was prepared by maceration of the dried plant and this was successively extracted with ethyl acetate to obtain an EtOAc extract and with n-butanol to obtain an n-BuOH extract. Column chromatography of the EtOAc and n-BuOH extracts was followed by purification of different fractions, leading to the isolation of 10 known compounds. Structures of isolated compounds were assigned on the basis of spectral analysis and by comparison to structures of compounds described in the literature. Antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and gallic acid equivalent antioxidant capacity (GAEAC) assays. Antibacterial activity was assessed with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) with respect to strains of a Gram-positive bacterium, Staphylococcus aureus (a major cause of community and hospital-associated infection), and Gram-negative multi-drug-resistant bacteria, Vibrio cholerae (a cause of cholera) and Shigella flexneri (a cause of shigellosis). All of the extracts showed different degrees of antioxidant and antibacterial activities. 2β-hydroxyoleanolic acid, (2R,3S,2''S)-3''',4',4''',5,5'',7,7''-heptahydroxy-3,8"-biflavanone, and luteolin-8-C-glucoside displayed the most potent antibacterial and antioxidant properties, and these properties were in some cases equal to or more potent than those of reference drugs. Overall, the present results show that L. leptocarpa has the potential to be a natural source of anti-diarrheal and antioxidant products, so further investigation is warranted. PMID:27431270

  8. The Content of Secondary Metabolites and Antioxidant Activity of Wild Strawberry Fruit (Fragaria vesca L.).

    PubMed

    Dyduch-Siemińska, Magdalena; Najda, Agnieszka; Dyduch, Jan; Gantner, Magdalena; Klimek, Kamila

    2015-01-01

    Chemical analyses carried out in 2011-2013 aimed at evaluating the contents of flavonoids, free phenolic acids, tannins, anthocyanins, and antioxidant activity (%) by means of DPPH radical neutralization ability in fresh and air-dried fruits of three wild strawberry cultivars. Examinations revealed differences in contents of biologically active substances determined in raw versus dried material depending on the cultivar. Mean concentrations of flavonoids and tannins were highest in raw fruits of "Baron von Solemacher" cv., which amounted to 1.244 mg·g(-1) and 6.09%, respectively. Fresh fruits of "Regina" cv. were characterized by the highest average content of phenolic acids and anthocyanins: 4.987 mg·g(-1) and 0.636 mg·100 g(-1). The pattern of mean contents of biologically active substances analyzed in air-dried fruits was similar. Significant differences in abilities to neutralize the DPPH radical to diphenylpicrylhydrazine by extracts made of examined wild strawberry fruits were also indicated. PMID:26539306

  9. Secondary metabolites from endophytic Streptomyces aureofaciens CMUAc130 and their antifungal activity.

    PubMed

    Taechowisan, Thongchai; Lu, Chunhua; Shen, Yuemao; Lumyong, Saisamorn

    2005-05-01

    Streptomyces aureofaciens CMUAc130 was isolated from the root tissue of Zingiber officinale Rosc. (Zingiberaceae). It was an antagonist of Colletotrichum musae and Fusarium oxysporum, the causative agents of anthracnose of banana and wilt of wheat, respectively. Evidence for the in vitro antibiosis of S. aureofaciens CMUAc130 was demonstrated by the zone of fungal-growth inhibition. Microscopic observations showed thickness and bulbous structures at the edges of the inhibited fungal hyphae. The culture filtrate and crude extract from this strain were all inhibitory to tested phytopathogenic fungi. The major active ingredients from the culture filtrate of S. aureofaciens CMUAc130 were purified by silica gel-column chromatography and identified to be (i) 5,7-dimethoxy-4-p-methoxylphenylcoumarin and (ii) 5,7-dimethoxy-4-phenylcoumarin by NMR and mass-spectral data, respectively. Bioassay studies showed that compounds (i) and (ii) had antifungal activities against tested fungi, and their MICs were found to be 120 and 150 microg ml(-1), respectively. This is the first report of compounds (i) and (ii) from micro-organisms as active ingredients for the control of phytopathogenic fungi. PMID:15870476

  10. The Content of Secondary Metabolites and Antioxidant Activity of Wild Strawberry Fruit (Fragaria vesca L.)

    PubMed Central

    Dyduch-Siemińska, Magdalena; Najda, Agnieszka; Dyduch, Jan; Gantner, Magdalena; Klimek, Kamila

    2015-01-01

    Chemical analyses carried out in 2011–2013 aimed at evaluating the contents of flavonoids, free phenolic acids, tannins, anthocyanins, and antioxidant activity (%) by means of DPPH radical neutralization ability in fresh and air-dried fruits of three wild strawberry cultivars. Examinations revealed differences in contents of biologically active substances determined in raw versus dried material depending on the cultivar. Mean concentrations of flavonoids and tannins were highest in raw fruits of “Baron von Solemacher” cv., which amounted to 1.244 mg·g−1 and 6.09%, respectively. Fresh fruits of “Regina” cv. were characterized by the highest average content of phenolic acids and anthocyanins: 4.987 mg·g−1 and 0.636 mg·100 g−1. The pattern of mean contents of biologically active substances analyzed in air-dried fruits was similar. Significant differences in abilities to neutralize the DPPH radical to diphenylpicrylhydrazine by extracts made of examined wild strawberry fruits were also indicated. PMID:26539306

  11. Hesperetin and its sulfate and glucuronide metabolites inhibit TNF-α induced human aortic endothelial cell migration and decrease plasminogen activator inhibitor-1 (PAI-1) levels.

    PubMed

    Giménez-Bastida, Juan Antonio; González-Sarrías, Antonio; Vallejo, Fernando; Espín, Juan Carlos; Tomás-Barberán, Francisco A

    2016-01-01

    Epidemiological, clinical and preclinical studies have reported the protection offered by citrus consumption, mainly orange, against cardiovascular diseases, which is primarily mediated by the antiatherogenic and vasculoprotective effects of the flavanone hesperetin-7-O-rutinoside (hesperidin). However, flavanone aglycones or glycosides are not present in the bloodstream but their derived phase-II metabolites could be the actual bioactive molecules. To date, only a few studies have explored the effects of circulating hesperetin-derived metabolites (glucuronides and sulfates) on endothelial cells. Herein, we describe for the first time the effects of hesperetin 3'-O-glucuronide, hesperetin 7-O-glucuronide, hesperetin 3'-O-sulfate, hesperetin 7-O-sulfate and hesperetin on human aortic endothelial cell (HAEC) migration upon pro-inflammatory stimuli as an essential step to angiogenesis. Hesperetin and its derived metabolites, at physiologically relevant concentrations (1-10 μM), significantly attenuated cell migration in the presence of the pro-inflammatory cytokine TNF-α (50 ng mL(-1)), which was accompanied and perhaps mediated by a significant decrease in the levels of the thrombogenic plasminogen activator inhibitor-1 (PAI-1). However, hesperetin metabolites did not counteract the TNF-α-induced production of pro-inflammatory interleukin-6 (IL-6) and IL-8. We also study here for the first time, the metabolism of hesperetin and its derived metabolites by HAEC with and without a pro-inflammatory stimulus. All these results reinforce the concept according to which circulating phase-II hesperetin metabolites are critical molecules contributing to the cardioprotective effects upon consumption of citrus fruits such as orange. PMID:26456097

  12. Lipid metabolism enzyme 5-LOX and its metabolite LTB4 are capable of activating transcription factor NF-{kappa}B in hepatoma cells

    SciTech Connect

    Zhao, Yu; Wang, Wenhui; Wang, Qi; Zhang, Xiaodong; Ye, Lihong

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer 5-LOX is able to upregulate expression of NF-{kappa}B p65. Black-Right-Pointing-Pointer 5-LOX enhances nuclear translocation of NF-{kappa}B p65 via increasing p-I{kappa}B-{alpha} level. Black-Right-Pointing-Pointer 5-LOX stimulates transcriptional activity of NF-{kappa}B in hepatoma cells. Black-Right-Pointing-Pointer LTB4 activates transcriptional activity of NF-{kappa}B in hepatoma cells. -- Abstract: The issue that lipid metabolism enzyme and its metabolites regulate transcription factors in cancer cell is not fully understood. In this study, we first report that the lipid metabolism enzyme 5-Lipoxygenase (5-LOX) and its metabolite leukotriene B4 (LTB4) are capable of activating nuclear factor-{kappa}B (NF-{kappa}B) in hepatoma cells. We found that the treatment of MK886 (an inhibitor of 5-LOX) or knockdown of 5-LOX was able to downregulate the expression of NF-{kappa}B p65 at the mRNA level and decreased the phosphorylation level of inhibitor {kappa}B{alpha} (I{kappa}B{alpha}) in the cytoplasm of hepatoma HepG2 or H7402 cells, which resulted in the decrease of the level of nuclear NF-{kappa}B p65. These were confirmed by immunofluorescence staining in HepG2 cell. Moreover, the above treatments were able to decrease the transcriptional activity of NF-{kappa}B in the cells. The LTB4, one of metabolites of 5-LOX, is responsible for 5-LOX-activated NF-{kappa}B in a dose-dependent manner. Thus, we conclude that the lipid metabolism enzyme 5-LOX and its metabolite LTB4 are capable of activating transcription factor NF-{kappa}B in hepatoma cells. Our finding provides new insight into the significance of lipid metabolism in activation of transcription factors in cancer.

  13. Profound reduction in the tamoxifen active metabolite endoxifen in a patient on phenytoin for epilepsy compared with a CYP2D6 genotype matched cohort.

    PubMed

    Gryn, Steven E; Teft, Wendy A; Kim, Richard B

    2014-07-01

    Tamoxifen is a prodrug, requiring cytochrome P450 enzyme-mediated metabolism to form the active metabolite endoxifen. We identified a case of drug-drug interaction involving tamoxifen and phenytoin, associated with a markedly lower endoxifen level than predicted. The patient is a 49-year-old woman, genotyped as a cytochrome P450 2D6 (CYP2D6) extensive metabolizer, chronically taking phenytoin for a seizure disorder. The plasma endoxifen level 2 months after starting tamoxifen was 4.72 nmol/l, the lowest level we have seen in our clinic among patients with CYP2D6 extensive metabolizer genotypes (n=195). To our knowledge, this is the first report documenting the extent of induction in terms of both tamoxifen and endoxifen levels during concomitant phenytoin therapy, and this effect would likely result in loss of therapeutic benefit from tamoxifen. Phenytoin should therefore not be used concurrently with tamoxifen for extended periods of time unless a therapeutic drug (endoxifen) monitoring strategy is utilized. PMID:24915025

  14. Mutational Analysis of AREA, a Transcriptional Activator Mediating Nitrogen Metabolite Repression in Aspergillus nidulans and a Member of the “Streetwise” GATA Family of Transcription Factors

    PubMed Central

    Wilson, Richard A.; Arst, Herbert N.

    1998-01-01

    Summary: The transcriptional activator AREA is a member of the GATA family of transcription factors and mediates nitrogen metabolite repression in the fungus Aspergillus nidulans. The nutritional versatility of A. nidulans and its amenability to classical and reverse genetic manipulations make the AREA DNA binding domain (DBD) a useful model for analyzing GATA family DBDs, particularly as structures of two AREA-DNA complexes have been determined. The 109 extant mutant forms of the AREA DBD surveyed here constitute one of the highest totals of eukaryotic transcription factor DBD mutants, are discussed in light of the roles of individual residues, and are compared to corresponding mutant sequence changes in other fungal GATA factor DBDs. Other topics include delineation of the DBD using both homology and mutational truncation, use of frameshift reversion to detect regions of tolerance to mutational change, the finding that duplication of the DBD can apparently enhance AREA function, and use of the AREA system to analyze a vertebrate GATA factor DBD. Some major points to emerge from work on the AREA DBD are (i) tolerance to sequence change (with retention of function) is surprisingly great, (ii) mutational changes in a transcription factor can have widely differing, even opposing, effects on expression of different structural genes so that monitoring expression of one or even several structural genes can be insufficient and possibly misleading, and (iii) a mutational change altering local hydrophobic packing and DNA binding target specificity can markedly influence the behavior of mutational changes elsewhere in the DBD. PMID:9729601

  15. Three New and Eleven Known Unusual C25 Steroids: Activated Production of Silent Metabolites in a Marine-Derived Fungus by Chemical Mutagenesis Strategy using Diethyl Sulphate

    PubMed Central

    Xia, Ming-Wen; Cui, Cheng-Bin; Li, Chang-Wei; Wu, Chang-Jing

    2014-01-01

    Three new (1–3) and 11 known (4–14) C25 steroids with an unusual bicyclo[4.4.1]A/B ring system were isolated by tracing newly produced metabolites in the EtOAc extract of an antitumor mutant AD-1-2 obtained by the diethyl sulphate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. HPLC-PDAD-UV and HPLC-ESI-MS analyses indicated that the G59 strain did not produce these metabolites and the production of 1–14 in the mutant AD-1-2 extract was caused by the activation of silent metabolites in the original G59 strain by DES mutagenesis. The structures of the new compounds, named antineocyclocitrinols A (1) and B (2) and 23-O-methylantineocyclocitrinol (3), including their absolute configurations were determined by various spectroscopic methods, especially the NMR and Mo2-induced CD analyses. Compounds 1–3 provide the first examples of the C25 bicyclo[4.4.1]A/B ring steroids with the Z-configuration of 20,22-double bond. All of 1–14 weakly inhibited several human cancer cell lines to varying extents. These results provided additional examples for the successful application of the chemical mutagenesis strategy using DES to discover new compounds by activating silent metabolites in fungal isolates and supported also the effectiveness and usefulness of this new strategy. PMID:24633254

  16. A facile reproducible radioimmunoassay of the mixed metabolites of prostaglandins E, suitable for measurement of relative differences of phospholipase/prostaglandin synthetase activity in vivo.

    PubMed

    Fretland, D J; Cammarata, P S

    1984-04-01

    A relatively simple, reproducible, radioimmunoassay for the mixed metabolites of prostaglandins E (U-PGE-M) in rat and human urine is described. Results of the assay of treated versus control urine extracts correlate well with differences expected from treatments known to alter in vivo phospholipase/prostaglandin synthetase activity. Cross-reactivity of heterogeneous metabolite antiserum with 5 available endogenous prostaglandins and a single metabolite was determined and showed little or no cross reaction. Sensitivity, within-assay precision, interassay reproducibility, and parallelism were also determined and found acceptable. Excretion rates of U-PGE-M by rats and humans were determined, and statistically significant differences could be shown, although absolute values were smaller than estimated absolute values obtained from mass-spectrometric measurements of single, purified metabolites. Normal human male excretion rates differed significantly from those of females. Injection of prostaglandin E1 caused a significant rise in U-PGE-M excretion in rats whereas aspirin and indomethacin caused it to fall. U-PGE-M excretion rates of spontaneous hypertensive rats were significantly less than rates of normotensive controls. Adrenalectomy resulted in excretion of significantly larger amounts of U-PGE-M than in normal or sham-operated controls. A screen of clinically active pharmacological agents and hormones gave results consistent with previously published reports. PMID:6427792

  17. Active curcumin nanoparticles formed from a volatile microemulsion template.

    PubMed

    Margulis, K; Srinivasan, S; Ware, M J; Summers, H D; Godin, B; Magdassi, S

    2014-01-01

    We report on biological performance of organic nanoparticles formed by a simple method based on rapid solvent removal from a volatile microemulsion. The particular focus of the study was on testing the suitability of the method for substances soluble in partially water-miscible organic solvents as well as on evaluating the therapeutic activity of the resultant nanoparticles. Curcumin was employed as a model for hydrophobic drug, and, as it is soluble in water-miscible organic solvents, it was successfully incorporated into a new cyclopentanone-water microemulsion system. During rapid solvent removal by spray-drying, the nanometric droplets of the microemulsion were converted into nanoparticles containing amorphous curcumin with the average size of 20.2±3.4 nm, having ζ potential of -36.2 ±1.8 mV. These nanoparticles were dispersible in water and retained the high loading of the active substance. The therapeutic activity of the resulting nanoparticles was demonstrated in a pancreatic cancer cell line Panc-1. The effective concentration for reducing the metabolic activity was found to be 11.5 μM for nanoparticles compared with 19.5 μM for free curcumin. PMID:25485110

  18. Characterization of two water-soluble lignin metabolites with antiproliferative activities from Inonotus obliquus.

    PubMed

    Wang, Qingjie; Mu, Haibo; Zhang, Lin; Dong, Dongqi; Zhang, Wuxia; Duan, Jinyou

    2015-03-01

    The chaga mushroom, Inonotus obliquus has long been recognized as a remedy for cancer, gastritis, ulcers, and tuberculosis of the bones since the 16th century. Herein we reported the identification of two homogenous biological macromolecules, designated as IOW-S-1 and IOW-S-2 with anti-tumor activities from the hot-water extract of I. obliquus. Their molecular weights were determined to be 37.9 and 24.5kDa by high performance gel permeation chromatography (HPGPC) respectively. Chemical and spectral analysis indicated that both IOW-S-1 and IOW-S-2 were predominant in lignin, along with ∼20% carbohydrates. Examination of cytotoxicity showed that these two lignin-carbohydrate complexes induced cell death in a concentration dependent manner, while this apoptosis induction was largely cell-cycle independent. Further investigation demonstrated that IOW-S-1 or IOW-S-2 inhibited the activation of the nuclear transcription factor in cancer cells. These findings implied that soluble lignin derivatives were one of bioactive components in I. obliquus, and further provided insights into the understanding of molecular basis for diverse medicinal and nutritional values of this mushroom. PMID:25583019

  19. Natural phenolic metabolites from endophytic Aspergillus sp. IFB-YXS with antimicrobial activity.

    PubMed

    Zhang, Wenjing; Wei, Wei; Shi, Jing; Chen, Chaojun; Zhao, Guoyan; Jiao, Ruihua; Tan, Renxiang

    2015-07-01

    Prompted by the pressing necessity to conquer phytopathogenic infections, the antimicrobial compounds were characterized with bioassay-guided method from the ethanol extract derived from the solid-substrate fermentation of Aspergillus sp. IFB-YXS, an endophytic fungus residing in the apparently healthy leave of Ginkgo biloba L. The aim of this work was to evaluate the antimicrobial activity and mechanism(s) of these bioactive compounds against phytopathogens. Among the compounds, xanthoascin (1) is significantly inhibitory on the growth of the phytopathogenic bacterium Clavibacter michiganense subsp. Sepedonicus with a minimum inhibitory concentration (MIC) value of 0.31μg/ml, which is more potent than streptomycin (MIC 0.62μg/ml), an antimicrobial drug co-assayed herein as a positive reference. Moreover, terphenyl derivatives 3, 5 and 6 are also found to be active against other phytopathogens including Xanthomonas oryzae pv. oryzae Swings, Xanthomonas oryzae pv. oryzicola Swings, Erwinia amylovora and Pseudomonas syringae pv. lachrymans etc. The antibacterial mechanism of xanthoascin (1) was addressed to change the cellular permeability of the phytopathogens, leading to the remarkable leakage of nucleic acids out of the cytomembrane. The work highlights the possibility that xanthoascin (1), an analogue of xanthocillin which is used to be an approved antibiotic, may find its renewed application as a potent antibacterial agrichemical. This study contributes to the development of new antimicrobial drugs, especially against C. michiganense subsp. Sepedonicus. PMID:26004581

  20. The In Vitro Antimicrobial Activities of Metabolites from Lactobacillus Strains on Candida Species Implicated in Candida Vaginitis

    PubMed Central

    Ogunshe, Adenike A O; Omotoso, Mopelola A; Bello, Victoria B

    2011-01-01

    Background: Research from developing countries, such as Nigeria, on Lactobacillus species in the female urogenital tract and their role as a barrier to vaginal infection is limited. Therefore, the aim of this study was to assess the clinical biotherapeutic potential of indigenous Lactobacillus species. Methods: Antimicrobial metabolites production were characterised using simple and easily reproducible qualitative and quantitative methods. The in vitro inhibitory effect of Lactobacillus antimicrobials on vulvovaginal candidiasis–associated Candida species was investigated using modified agar spot and agar well-diffusion methods. Results: The maximum levels of lactic acid, hydrogen peroxide, and diacetyl from 20 vaginal Lactobacillus strains from diseased subjects were 1.46 mg/L, 1.36 mmol/L, and 1.72 mg/L respectively. From the 4 healthy subjects, the maximum level of lactic acid was 1.08 mg/L; hydrogen peroxide, 1.36 mmol/L; and diacetyl, 0.86 mg/L. The maximum productions of these substances occurred between 72 and 120 hours of incubation. The in vitro antagonistic activities of vaginal L. acidophilus, L. fermentum, L. brevis, L. plantarum, L. casei, L. delbrueckii, and L. jensenii from diseased subjects inhibited a maximum of 5.71% of the 35 Candida species tested, while vaginal L. acidophilus and L. plantarum from healthy subjects inhibited between 57.1% and 68.6% of Candida species in vitro. Conclusion: Antimicrobial-producing lactobacilli can be considered as adjunct biotherapeutic candidates for the treatment of vulvovaginal candidiasis. PMID:22589669

  1. Bioaccessible (poly)phenol metabolites from raspberry protect neural cells from oxidative stress and attenuate microglia activation.

    PubMed

    Garcia, Gonçalo; Nanni, Sara; Figueira, Inês; Ivanov, Ines; McDougall, Gordon J; Stewart, Derek; Ferreira, Ricardo B; Pinto, Paula; Silva, Rui F M; Brites, Dora; Santos, Cláudia N

    2017-01-15

    Neuroinflammation is an integral part of the neurodegeneration process inherent to several aging dysfunctions. Within the central nervous system, microglia are the effective immune cells, responsible for neuroinflammatory responses. In this study, raspberries were subjected to in vitro digestion simulation to obtain the components that result from the gastrointestinal (GI) conditions, which would be bioaccessible and available for blood uptake. Both the original raspberry extract and the gastrointestinal bioaccessible (GIB) fraction protected neuronal and microglia cells against H2O2-induced oxidative stress and lipopolysaccharide (LPS)-induced inflammation, at low concentrations. Furthermore, this neuroprotective capacity was independent of intracellular ROS scavenging mechanisms. We show for the first time that raspberry metabolites present in the GIB fraction significantly inhibited microglial pro-inflammatory activation by LPS, through the inhibition of Iba1 expression, TNF-α release and NO production. Altogether, this study reveals that raspberry polyphenols may present a dietary route to the retardation or amelioration of neurodegenerative-related dysfunctions. PMID:27542476

  2. Aspirin’s Active Metabolite Salicylic Acid Targets High Mobility Group Box 1 to Modulate Inflammatory Responses

    PubMed Central

    Choi, Hyong Woo; Tian, Miaoying; Song, Fei; Venereau, Emilie; Preti, Alessandro; Park, Sang-Wook; Hamilton, Keith; Swapna, G V T; Manohar, Murli; Moreau, Magali; Agresti, Alessandra; Gorzanelli, Andrea; De Marchis, Francesco; Wang, Huang; Antonyak, Marc; Micikas, Robert J; Gentile, Daniel R; Cerione, Richard A; Schroeder, Frank C; Montelione, Gaetano T; Bianchi, Marco E; Klessig, Daniel F

    2015-01-01

    Salicylic acid (SA) and its derivatives have been used for millennia to reduce pain, fever and inflammation. In addition, prophylactic use of acetylsalicylic acid, commonly known as aspirin, reduces the risk of heart attack, stroke and certain cancers. Because aspirin is rapidly de-acetylated by esterases in human plasma, much of aspirin’s bioactivity can be attributed to its primary metabolite, SA. Here we demonstrate that human high mobility group box 1 (HMGB1) is a novel SA-binding protein. SA-binding sites on HMGB1 were identified in the HMG-box domains by nuclear magnetic resonance (NMR) spectroscopic studies and confirmed by mutational analysis. Extracellular HMGB1 is a damage-associated molecular pattern molecule (DAMP), with multiple redox states. SA suppresses both the chemoattractant activity of fully reduced HMGB1 and the increased expression of proinflammatory cytokine genes and cyclooxygenase 2 (COX-2) induced by disulfide HMGB1. Natural and synthetic SA derivatives with greater potency for inhibition of HMGB1 were identified, providing proof-of-concept that new molecules with high efficacy against sterile inflammation are attainable. An HMGB1 protein mutated in one of the SA-binding sites identified by NMR chemical shift perturbation studies retained chemoattractant activity, but lost binding of and inhibition by SA and its derivatives, thereby firmly establishing that SA binding to HMGB1 directly suppresses its proinflammatory activities. Identification of HMGB1 as a pharmacological target of SA/aspirin provides new insights into the mechanisms of action of one of the world’s longest and most used natural and synthetic drugs. It may also provide an explanation for the protective effects of low-dose aspirin usage. PMID:26101955

  3. Biodegradation of Triton X-100 and its primary metabolites by a bacterial community isolated from activated sludge.

    PubMed

    Wyrwas, Bogdan; Dymaczewski, Zbysław; Zgoła-Grześkowiak, Agnieszka; Szymański, Andrzej; Frańska, Magdalena; Kruszelnicka, Izabela; Ginter-Kramarczyk, Dobrochna; Cyplik, Paweł; Ławniczak, Łukasz; Chrzanowski, Łukasz

    2013-10-15

    A set of studies was carried using a continuous flow biodegradation unit in order to isolate a microbial community capable of efficient and complete utilization of octylphenol ethoxylates from activated sludge. Increasing concentrations of Triton X-100 (in the range of 1-1000 mg/l) were applied over a time period of 35 days in order to select microorganisms, which exhibit high tolerance towards this surfactant. The fate of the surfactant and its primary degradation products was assessed by HPLC/MS. It was observed that even small doses of the surfactant contributed to the disruption of the activated sludge, due to adsorption of primary Triton X-100 metabolites (octylphenol and short-chained ethoxylates) on the cells, although the long-chain octylphenol ethoxylates were efficiently degraded during the isolation process. The toxicity assessment of octylphenol as well as octylphenol di- and monoethoxylates towards activated sludge allowed for determination of EC50 values (8 and 55 mg/l, respectively). The identification of the residual microorganisms revealed the presence of Acinetobacter junii, Acinetobacter calcoaceticus, Aeromonas hydrophilia, Alcaligenes spp., Pseudomonas fluorescens and Sphingomonas capsulata. The isolated community exhibited a high resistance towards Triton X-100 and was capable of growth even at 10,000 mg/l, with the highest specific growth rate (0.47 h(-1)) observed at 4000 mg/l. Under aerobic conditions both octylphenol and the short-chained ethoxylates were completely degraded while no toxic effect towards the isolated bacterial community was observed. PMID:23770380

  4. Purification of human dihydro-orotate dehydrogenase and its inhibition by A77 1726, the active metabolite of leflunomide.

    PubMed Central

    Bruneau, J M; Yea, C M; Spinella-Jaegle, S; Fudali, C; Woodward, K; Robson, P A; Sautès, C; Westwood, R; Kuo, E A; Williamson, R A; Ruuth, E

    1998-01-01

    Leflunomide is currently in phase-III clinical trials for the treatment of rheumatoid arthritis. In this study, we have focused our efforts on the study of the mechanism of action of the active metabolite of leflunomide, A77 1726, in cells and tissue of human origin. The human high-affinity binding protein for radiolabelled A77 1726 was purified from solubilized U937 membranes by following the binding activity through the purification process and was characterized as the mitochondrial enzyme dihydro-orotate dehydrogenase (DHO-DH). The human and murine enzyme displayed identical pI and molecular mass values on SDS/PAGE (43 kDa), which contrasts notably with previous reports suggesting a molecular mass of 50 kDa for the human enzyme. DHO-DH activity was inhibited by A77 1726 and its analogue HR325 with similar potency in U937 and human spleen membrane preparations. HR325 was found to be anti-proliferative for phytohaemagglutinin-stimulated human peripheral blood mononuclear cells, at the same concentrations that caused accumulation of DHO and depletion of uridine. Supplementation of the cultures with exogenous uridine led to partial abrogation of the anti-proliferative effect. This is in line with our recent demonstration that the anti-proliferative effect in vitro of A77 1726 on lipopolysaccharide-stimulated mouse spleen cells was mediated by DHO-DH inhibition [Williamson, Yea, Robson, Curnock, Gadher, Hambleton, Woodward, Bruneau, Hambleton, Moss et al., (1995) J. Biol. Chem. 270, 22467-22472]. Thus, DHO-DH inhibition by A77 1726 and its analogues is responsible for the anti-proliferative effects in vitro of the compounds on human cells and is likely to be responsible for some of its effects in vivo. PMID:9820804

  5. Using Molecular Networking for Microbial Secondary Metabolite Bioprospecting

    PubMed Central

    Purves, Kevin; Macintyre, Lynsey; Brennan, Debra; Hreggviðsson, Guðmundur Ó.; Kuttner, Eva; Ásgeirsdóttir, Margrét E.; Young, Louise C.; Green, David H.; Edrada-Ebel, Ruangelie; Duncan, Katherine R.

    2016-01-01

    The oceans represent an understudied resource for the isolation of bacteria with the potential to produce novel secondary metabolites. In particular, actinomyces are well known to produce chemically diverse metabolites with a wide range of biological activities. This study characterised spore-forming bacteria from both Scottish and Antarctic sediments to assess the influence of isolation location on secondary metabolite production. Due to the selective isolation method used, all 85 isolates belonged to the phyla Firmicutes and Actinobacteria, with the majority of isolates belonging to the genera Bacillus and Streptomyces. Based on morphology, thirty-eight isolates were chosen for chemical investigation. Molecular networking based on chemical profiles (HR-MS/MS) of fermentation extracts was used to compare complex metabolite extracts. The results revealed 40% and 42% of parent ions were produced by Antarctic and Scottish isolated bacteria, respectively, and only 8% of networked metabolites were shared between these locations, implying a high degree of biogeographic influence upon secondary metabolite production. The resulting molecular network contained over 3500 parent ions with a mass range of m/z 149–2558 illustrating the wealth of metabolites produced. Furthermore, seven fermentation extracts showed bioactivity against epithelial colon adenocarcinoma cells, demonstrating the potential for the discovery of novel bioactive compounds from these understudied locations. PMID:26761036

  6. Targeted metabolite analysis and biological activity of Pieris brassicae fed with Brassica rapa var. rapa.

    PubMed

    Pereira, David M; Noites, Alexandra; Valentão, Patricia; Ferreres, Federico; Pereira, José A; Vale-Silva, Luis; Pinto, Eugénia; Andrade, Paula B

    2009-01-28

    For the first time, an insect-plant system, Pieris brassicae fed with Brassica rapa var. rapa, was tested for its biological capacity, namely, antioxidant (DPPH*, *NO, and O(2)*- radicals) and antimicrobial (bacteria and fungi) activities. Samples from the insect's life cycle (larvae, excrements, exuviae, and butterfly) were always found to be more efficient than the host plant. Also, P. brassicae materials, as well as its host plant, were screened for phenolics and organic acids. The host plant revealed higher amounts of both compounds. Two phenolic acids, ferulic and sinapic, as well as kaempferol 3-Osophoroside, were common to insect (larvae and excrements) and plant materials, with excrements being considerably richer. Detection of sulfated compounds in excrements, absent in host plant, revealed that metabolic processes in this species involved sulfation. Additionally, deacylation and deglycosilation were observed. All matrices presented the same organic acids qualitative profile, with the exception of excrements. PMID:19115952

  7. Isolation, structure, and HIV-1-integrase inhibitory activity of structurally diverse fungal metabolites.

    PubMed

    Singh, Sheo B; Jayasuriya, Hiranthi; Dewey, Raymond; Polishook, Jon D; Dombrowski, Anne W; Zink, Deborah L; Guan, Ziqiang; Collado, Javier; Platas, Gonzalo; Pelaez, Fernando; Felock, Peter J; Hazuda, Daria J

    2003-12-01

    HIV-1 integrase is a critical enzyme for replication of HIV, and its inhibition is one of the most promising new drug strategies for anti-retroviral therapy, with potentially significant advantages over existing therapies. In this report, a series of HIV-1 inhibitors isolated from the organic extract of fermentations from terrestrial fungi is described. These fungal species, belonging to a variety of genera, were collected from throughout the world following the strict guidelines of Rio Convention on Biodiversity. The polyketide- and terpenoid-derived inhibitors are represented by two naphthoquinones, a biphenyl and two triphenyls, a benzophenone, four aromatics with or without catechol units, a linear aliphatic terpenoid, a diterpenoid, and a sesterterpenoid. These compounds inhibited the coupled and strand-transfer reaction of HIV-1 integrase with an IC(50) value of 0.5-120 micro M. The bioassay-directed isolation, structure elucidation, and HIV-1 inhibitory activity of these compounds are described. PMID:14714192

  8. Chemistry of the Nudibranch Aldisa andersoni: Structure and Biological Activity of Phorbazole Metabolites

    PubMed Central

    Nuzzo, Genoveffa; Ciavatta, Maria Letizia; Kiss, Robert; Mathieu, Véronique; Leclercqz, Helene; Manzo, Emiliano; Villani, Guido; Mollo, Ernesto; Lefranc, Florence; D’Souza, Lisette; Gavagnin, Margherita; Cimino, Guido

    2012-01-01

    The first chemical study of the Indo-Pacific dorid nudibranch Aldisa andersoni resulted in the isolation of five chlorinated phenyl-pyrrolyloxazoles belonging to the phorbazole series. Two new molecules, 9-chloro-phorbazole D and N1-methyl-phorbazole A, co-occurring with known phorbazoles A, B and D, have been characterized. Phorbazoles were found to be present mainly in the external part of the mollusc. The structures of the new compounds were determined by interpretation of spectroscopic data, mainly NMR and mass spectrometry and by comparison with the literature data. Evaluation of feeding-deterrence activity as well as in vitro growth inhibitory properties in human cancer cells was also carried out. PMID:23015775

  9. Exposure to benzene metabolites causes oxidative damage in Saccharomyces cerevisiae.

    PubMed

    Raj, Abhishek; Nachiappan, Vasanthi

    2016-06-01

    Hydroquinone (HQ) and benzoquinone (BQ) are known benzene metabolites that form reactive intermediates such as reactive oxygen species (ROS). This study attempts to understand the effect of benzene metabolites (HQ and BQ) on the antioxidant status, cell morphology, ROS levels and lipid alterations in the yeast Saccharomyces cerevisiae. There was a reduction in the growth pattern of wild-type cells exposed to HQ/BQ. Exposure of yeast cells to benzene metabolites increased the activity of the anti-oxidant enzymes catalase, superoxide dismutase and glutathione peroxidase but lead to a decrease in ascorbic acid and reduced glutathione. Increased triglyceride level and decreased phospholipid levels were observed with exposure to HQ and BQ. These results suggest that the enzymatic antioxidants were increased and are involved in the protection against macromolecular damage during oxidative stress; presumptively, these enzymes are essential for scavenging the pro-oxidant effects of benzene metabolites. PMID:27016252

  10. In vitro effects of brominated flame retardants and metabolites on CYP17 catalytic activity: A novel mechanism of action?

    SciTech Connect

    Canton, Rocio F. . E-mail: r.Fernandezcanton@iras.uu.nl; Sanderson, J. Thomas; Nijmeijer, Sandra; Bergman, Ake; Letcher, Robert J.; Berg, Martin van den

    2006-10-15

    Fire incidents have decreased significantly over the last 20 years due, in part, to regulations requiring addition of flame retardants (FRs) to consumer products. Five major classes of brominated flame retardants (BFRs) are hexabromocyclododecane isomers (HBCDs), tetrabromobisphenol-A (TBBPA) and three commercial mixtures of penta-, octa- and deca-polybrominated diphenyl ether (PBDE) congeners, which are used extensively as commercial FR additives. Furthermore, concentrations of PBDEs have been rapidly increasing during the 1999s in human breast milk and a number of endocrine effects have been reported. We used the H295R human adrenocortical carcinoma cell line to assess possible effects of some of these BFRs (PBDEs and several of their hydroxylated (OH) and methoxylated (CH{sub 3}O) metabolites or analogues), TBBPA and brominated phenols (BPs) on the combined 17{alpha}-hydroxylase and 17,20-lyase activities of CYP17. CYP17 enzyme catalyzes an important step in sex steroidogenesis and is responsible for the biosynthesis of dehydroepiandrosterone (DHEA) and androstenedione in the adrenals. In order to study possible interactions with BFRs, a novel enzymatic method was developed. The precursor substrate of CYP17, pregnenolone, was added to control and exposed H295R cells, and enzymatic production of DHEA was measured using a radioimmunoassay. In order to avoid pregnenolone metabolism via different pathways, specific chemical inhibitor compounds were used. None of the parent/precursor BFRs had a significant effect (P < 0.05) on CYP17 activity except for BDE-183, which showed significant inhibition of CYP17 activity at the highest concentration tested (10 {mu}M), with no signs of cytotoxicity as measured by mitochondrial toxicity tests (MTT). A strong inhibition of CYP17 activity was found for 6-OH-2,2',4,4'-tetrabromoDE (6-OH-BDE47) with a concentration-dependent decrease of almost 90% at 10 {mu}M, but with a concurrent decrease in cell viability at the higher

  11. The effect of the inclusion of recycled poultry bedding and the physical form of diet on the performance, ruminal fermentation, and plasma metabolites of fattening lambs.

    PubMed

    Mirmohammadi, D; Rouzbehan, Y; Fazaeli, H

    2015-08-01

    During a 125-d experimental period, 24 Afshari × Kurdish male lambs initially weighing 25.2 ± 1.2 kg were grouped by BW and randomly assigned to treatments under a completely randomized design with a 2 × 2 factorial arrangement of treatments to evaluate the effects of feeding recycled poultry bedding (RPB; 0 and 200 g/kg DM) and the physical form of the diet (mash and block) on nutrient intake and digestibility, ruminal and plasma parameters, microbial N supply, N balance, feeding behavior, and growth performance of the lambs. Two diets with and without RPB in both mash and block form were prepared. Neither the inclusion of RPB nor the physical form of the diet affected the concentration of VFA or the total tract apparent digestibility of nutrients. Dietary RPB inclusion increased DMI ( < 0.01), tended ( = 0.10) to reduce ADG, and decreased G:F ( = 0.05). The physical form of the diet had no effect on DMI but decreased ADG ( = 0.01) and G:F ( = 0.02) in lambs fed on the block diet compared with those fed on the mash diet. Neither the inclusion of RPB nor the physical form of the diets had any effect on microbial N supply (g/d) and N retention. Rate of eating ( = 0.07), time spent eating ( = 0.87) and ruminating ( = 0.28), and total chewing activity ( = 0.65) were not affected by dietary RPB inclusion. Rate of eating decreased ( < 0.01) and time spent eating and total chewing activity increased ( = 0.01 and = 0.02, respectively) in lambs fed on the block diet compared with those fed on the mash diet. Results of the current study showed that inclusion of RPB up to 200 g/kg DM in diets for fattening was possible without any effect on performance and animal health. Processing of feed into the mash form gave higher livestock productivity in comparison to the block form. PMID:26440164

  12. Antifungal Activity Against Plant Pathogens of Metabolites from the Endophytic Fungus Cladosporium cladosporioides

    PubMed Central

    Wang, Xiaoning; Radwan, Mohamed M.; Taráwneh, Amer H.; Gao, Jiangtao; Wedge, David E.; Rosa, Luiz H.; Cutler, Horace G.; Cutler, Stephen J.

    2013-01-01

    Bioassay-guided fractionation of Cladosporium cladosporioides (Fresen.) de Vries extracts led to the isolation of four compounds, including cladosporin, 1, isocladosporin, 2, 5′-hydroxyasperentin, 3, and cladosporin-8-methyl ether, 4. An additional compound 5′,6-diacetyl cladosporin, 5, was synthesized by acetylation of compound 3. Compounds 1-5 were evaluated for antifungal activity against plant pathogens. Phomopsis viticola was the most sensitive fungus to the tested compounds. At 30 μM, compound 1 exhibited 92.7%, 90.1%, 95.4% and 79.9% growth inhibition against Colletotrichum acutatum, Co. fragariae, Co. gloeosporioides and Phomopsis viticola, respectively. Compound 2 showed 50.4%, 60.2% and 83.0% growth inhibition at 30 μM against Co. fragariae, Co. gloeosporioides and P. viticola, respectively. Compounds 3 and 4 were isolated for the first time from Cladosporium cladosporioides. Moreover, the identification of essential structural features of the cladosporin nuclei has also been evaluated. These structures provide new templates for the potential treatment and management of plant diseases. PMID:23651409

  13. Inclusion bodies and purification of proteins in biologically active forms.

    PubMed

    Mukhopadhyay, A

    1997-01-01

    Even though recombinant DNA technology has made possible the production of valuable therapeutic proteins, its accumulation in the host cell as inclusion body poses serious problems in the recovery of functionally active proteins. In the last twenty years, alternative techniques have been evolved to purify biologically active proteins from inclusion bodies. Most of these remain only as inventions and very few are commercially exploited. This review summarizes the developments in isolation, refolding and purification of proteins from inclusion bodies that could be used for vaccine and non-vaccine applications. The second section involves a discussion on inclusion bodies, how they are formed, and their physicochemical properties. In vivo protein folding in Escherichia coli and kinetics of in vitro protein folding are the subjects of the third and fourth sections respectively. The next section covers the recovery of bioactive protein from inclusion bodies: it includes isolation of inclusion body from host cell debris, purification in denatured state alternate refolding techniques, and final purification of active molecules. Since purity and safety are two important issues in therapeutic grade proteins, the following three sections are devoted to immunological and biological characterization of biomolecules, nature, and type of impurities normally encountered, and their detection. Lastly, two case studies are discussed to demonstrate the sequence of process steps involved. PMID:8939059

  14. Determination of some selected secondary metabolites and their invitro antioxidant activity in commercially available Ethiopian tea (Camellia sinensis).

    PubMed

    Bizuayehu, Dereje; Atlabachew, Minaleshewa; Ali, Mirtachew Tihar

    2016-01-01

    Eight brands of tea (Camellia sinensis),which are cultivated and commercially available in Ethiopian market, were analyzed for estimation of their total secondary metabolites (polyphenols, flavonoids and tannins) content and free radical scavenging activity which is expressed on dry weight basis. In this present study, the total polyphenols, tannin and flavonoid contents were studied spectrophotometrically using Folin-Dennis, Folin-Dennis/protein precipitation and aluminium chloride methods respectively. The free radical scavenging activity was determined by using DPPH radical assay. Results of the analysis revealed that the total polyphenol content varied from 21.3 ± 0.24 to 31.6 ± 0.31 mg of gallic acid equivalent/g of dry matter. Total flavonoids content in the tea samples varied from 8.17 ± 0.68 to 23.2 ± 0.68 mg of catechin equivalent/g of dry weight and tannin content varied from 5.64 ± 0.39 7.45 ± 0.27 mg tannic acid equivalent/g of dry weight basis. The free radical scavenging activity among the tea brand samples ranged from 28.8 ± 1.86 to 80.0 ± 0.63 mg ascorbic acid equivalent/g and the half maximal inhibitory concentration (IC50%) values varied from 7.3 ± 1.35 to 64.0 ± 2.81 µg/mL of extract. The correlation between the antioxidant activity with total polyphenol content (R = 0.91325), with flavonoids (R = 0.80658) and with tannin (R = 0.73125) was calculated and maximum correlation value was found between polyphenol content and the free radical scavenging activity of the tea samples. The results in this study also revealed that green tea had the higher polyphenolic content and found to have the most promising antioxidant activity. This study further confirmed that Ethiopia tea is reach in phenolic compounds as compared to some overseas tea cultivars/varieties. PMID:27069832

  15. Activation and silencing of secondary metabolites in Streptomyces albus and Streptomyces lividans after transformation with cosmids containing the thienamycin gene cluster from Streptomyces cattleya.

    PubMed

    Braña, Alfredo F; Rodríguez, Miriam; Pahari, Pallab; Rohr, Jurgen; García, Luis A; Blanco, Gloria

    2014-05-01

    Activation and silencing of antibiotic production was achieved in Streptomyces albus J1074 and Streptomyces lividans TK21 after introduction of genes within the thienamycin cluster from S. cattleya. Dramatic phenotypic and metabolic changes, involving activation of multiple silent secondary metabolites and silencing of others normally produced, were found in recombinant strains harbouring the thienamycin cluster in comparison to the parental strains. In S. albus, ultra-performance liquid chromatography purification and NMR structural elucidation revealed the identity of four structurally related activated compounds: the antibiotics paulomycins A, B and the paulomenols A and B. Four volatile compounds whose biosynthesis was switched off were identified by gas chromatography-mass spectrometry analyses and databases comparison as pyrazines; including tetramethylpyrazine, a compound with important clinical applications to our knowledge never reported to be produced by Streptomyces. In addition, this work revealed the potential of S. albus to produce many others secondary metabolites normally obtained from plants, including compounds of medical relevance as dihydro-β-agarofuran and of interest in perfume industry as β-patchoulene, suggesting that it might be an alternative model for their industrial production. In S. lividans, actinorhodins production was strongly activated in the recombinant strains whereas undecylprodigiosins were significantly reduced. Activation of cryptic metabolites in Streptomyces species might represent an alternative approach for pharmaceutical drug discovery. PMID:24633227

  16. Identification of alcohol-dependent clopidogrel metabolites using conventional liquid chromatography/triple quadrupole mass spectrometry

    PubMed Central

    Hu, Zhe-Yi; Laizure, S. Casey; Herring, Vanessa L.; Parker, Robert B.

    2014-01-01

    RATIONALE Clopidogrel (CLO) is a prodrug used to prevent ischemic events in patients undergoing percutaneous coronary intervention or with myocardial infarction. A previous study found ethyl clopidogrel (ECLO) is formed by transesterification of CLO when incubated with alcohol in human liver microsomes. We hypothesize that ECLO will be subject to further metabolism and developed an assay to identify its metabolites. METHODS A liquid chromatography/triple quadrupole mass spectrometry (LC-MS/MS) method was developed to identify metabolites of ECLO. According to the predicted metabolic pathway of ECLO, precursor–product ion pairs were used to screen the possible metabolites of ECLO in human liver S9 fractions. Subsequently, the detected metabolites were characterized by the results of product ion scan. RESULTS In the presence of alcohol, CLO was tranesterified to ECLO, which was further oxidized to form ethylated 2-oxo-clopidogrel and several ethylated thiol metabolites including the ethylated form of the H4 active metabolite. CONCLUSIONS The ECLO formed by transesterification with alcohol is subject to metabolism by CYP450 enzymes producing ethylated forms of 2-oxo-clopidogrel and the active H4 thiol metabolite. PMID:24760569

  17. Effects of chloro-s-triazine herbicides and metabolites on aromatase activity in various human cell lines and on vitellogenin production in male carp hepatocytes.

    PubMed Central

    Sanderson, J T; Letcher, R J; Heneweer, M; Giesy, J P; van den Berg, M

    2001-01-01

    We investigated a potential mechanism for the estrogenic properties of three chloro-s-triazine herbicides and six metabolites in vitro in several cell systems. We determined effects on human aromatase (CYP19), the enzyme that converts androgens to estrogens, in H295R (adrenocortical carcinoma), JEG-3 (placental choriocarcinoma), and MCF-7 (breast cancer) cells; we determined effects on estrogen receptor-mediated induction of vitellogenin in primary hepatocyte cultures of adult male carp (Cyprinus carpio). In addition to atrazine, simazine, and propazine, two metabolites--atrazine-desethyl and atrazine-desisopropyl--induced aromatase activity in H295R cells concentration-dependently (0.3-30 microM) and with potencies similar to those of the parent triazines. After a 24-hr exposure to 30 microM of the triazines, an apparent maximum induction of about 2- to 2.5-fold was achieved. The induction responses were confirmed by similar increases in CYP19 mRNA levels, determined by reverse-transcriptase polymerase chain reaction. In JEG-3 cells, where basal aromatase expression is about 15-fold greater than in H295R cells, the induction responses were similar but less pronounced; aromatase expression in MCF-7 cells was neither detectable nor inducible under our culture conditions. The fully dealkylated metabolite atrazine-desethyl-desisopropyl and the three hydroxylated metabolites (2-OH-atrazine-desethyl, -desisopropyl, and -desethyl-desisopropyl) did not induce aromatase activity. None of the triazine herbicides nor their metabolites induced vitellogenin production in male carp hepatocytes; nor did they antagonize the induction of vitellogenin by 100 nM (EC(50) 17beta-estradiol. These findings together with other reports indicate that the estrogenic effects associated with the triazine herbicides in vivo are not estrogen receptor-mediated, but may be explained partly by their ability to induce aromatase in vitro. PMID:11675267

  18. Substitution of Wheat for Corn in Beef Cattle Diets: Digestibility, Digestive Enzyme Activities, Serum Metabolite Contents and Ruminal Fermentation.

    PubMed

    Liu, Y F; Zhao, H B; Liu, X M; You, W; Cheng, H J; Wan, F C; Liu, G F; Tan, X W; Song, E L; Zhang, X L

    2016-10-01

    The objective of this study was to evaluate the effect of diets containing different amounts of wheat, as a partial or whole substitute for corn, on digestibility, digestive enzyme activities, serum metabolite contents and ruminal fermentation in beef cattle. Four Limousin×LuXi crossbred cattle with a body weight (400±10 kg), fitted with permanent ruminal, proximal duodenal and terminal ileal cannulas, were used in a 4×4 Latin square design with four treatments: Control (100% corn), 33% wheat (33% substitution for corn), 67% wheat (67% substitution for corn), and 100% wheat (100% substitution for corn) on a dry matter basis. The results showed that replacing corn with increasing amounts of wheat increased the apparent digestibility values of dry matter, organic matter, and crude protein (p<0.05). While the apparent digestibility of acid detergent fiber and neutral detergent fiber were lower with increasing amounts of wheat. Digestive enzyme activities of lipase, protease and amylase in the duodenum were higher with increasing wheat amounts (p<0.05), and showed similar results to those for the enzymes in the ileum except for amylase. Increased substitution of wheat for corn increased the serum alanine aminotransferase concentration (p<0.05). Ruminal pH was not different between those given only corn and those given 33% wheat. Increasing the substitution of wheat for corn increased the molar proportion of acetate and tended to increase the acetate-to-propionate ratio. Cattle fed 100% wheat tended to have the lowest ruminal NH3-N concentration compared with control (p<0.05), whereas no differences were observed among the cattle fed 33% and 67% wheat. These findings indicate that wheat can be effectively used to replace corn in moderate amounts to meet the energy and fiber requirements of beef cattle. PMID:26954111

  19. Cardiac Energy Dependence on Glucose Increases Metabolites Related to Glutathione and Activates Metabolic Genes Controlled by Mechanistic Target of Rapamycin

    PubMed Central

    Schisler, Jonathan C.; Grevengoed, Trisha J.; Pascual, Florencia; Cooper, Daniel E.; Ellis, Jessica M.; Paul, David S.; Willis, Monte S.; Patterson, Cam; Jia, Wei; Coleman, Rosalind A.

    2015-01-01

    Background Long chain acyl‐CoA synthetases (ACSL) catalyze long‐chain fatty acids (FA) conversion to acyl‐CoAs. Temporal ACSL1 inactivation in mouse hearts (Acsl1H−/−) impaired FA oxidation and dramatically increased glucose uptake, glucose oxidation, and mTOR activation, resulting in cardiac hypertrophy. We used unbiased metabolomics and gene expression analyses to elucidate the cardiac cellular response to increased glucose use in a genetic model of inactivated FA oxidation. Methods and Results Metabolomics analysis identified 60 metabolites altered in Acsl1H−/− hearts, including 6 related to glucose metabolism and 11 to cysteine and glutathione pathways. Concurrently, global cardiac transcriptional analysis revealed differential expression of 568 genes in Acsl1H−/− hearts, a subset of which we hypothesized were targets of mTOR; subsequently, we measured the transcriptional response of several genes after chronic mTOR inhibition via rapamycin treatment during the period in which cardiac hypertrophy develops. Hearts from Acsl1H−/− mice increased expression of several Hif1α‐responsive glycolytic genes regulated by mTOR; additionally, expression of Scl7a5, Gsta1/2, Gdf15, and amino acid‐responsive genes, Fgf21, Asns, Trib3, Mthfd2, were strikingly increased by mTOR activation. Conclusions The switch from FA to glucose use causes mTOR‐dependent alterations in cardiac metabolism. We identified cardiac mTOR‐regulated genes not previously identified in other cellular models, suggesting heart‐specific mTOR signaling. Increased glucose use also changed glutathione‐related pathways and compensation by mTOR. The hypertrophy, oxidative stress, and metabolic changes that occur within the heart when glucose supplants FA as a major energy source suggest that substrate switching to glucose is not entirely benign. PMID:25713290

  20. Antibacterial and antioxidant activity of the secondary metabolites from in vitro cultures of the Alice sundew (Drosera aliciae).

    PubMed

    Krolicka, Aleksandra; Szpitter, Anna; Maciag, Monika; Biskup, Edyta; Gilgenast, Ewelina; Wegrzyn, Grazyna; Lojkowska, Ewa

    2009-07-01

    The objective of the present study was to evaluate the antioxidant as well as the antibacterial properties of secondary metabolites obtained from Drosera aliciae (Alice sundew) plants grown in vitro and to examine the mechanism of their antimicrobial action. Bactericidal activity of extracts from D. aliciae, as well as pure ramentaceone (naphthoquinone), which is present in this plant, were examined against human pathogenic strains of micro-organisms that are both resistant and susceptible to antibiotics. A chloroform extract proved to be more effective than a methanol preparation against all of the tested strains, except for Pseudomonas aeruginosa isolates. The lowest minimal-bactericidal-concentration value was in the case of Staphylococcus aureus (25-50 mg fresh weight·ml(-1)). The influence of D. aliciae extracts and ramentaceone on the synthesis of DNA, RNA or proteins in cultures of Enterococcus faecalis was estimated by measurement of the incorporation of the radioactively labelled precursors [3H]thymidine, [3H]uridine or [3H]leucine respectively. The methanol extract of D. aliciae, except for a moderate effect on DNA synthesis, had no influence on RNA and protein synthesis. The chloroform preparation caused about a 75% decrease in [3H]uridine incorporation in comparison with the control after 60 min and a significant diminution in DNA and protein synthesis (44 and 30% respectively). Ramentaceone also decreased DNA and RNA synthesis, but less efficiently than did the chloroform extract, and it caused no changes in [3H]leucine incorporation. The methanol extract from D. aliciae proved to be an effective antioxidant in both the DPPH (2,2-diphenyl-10-picrylhydrazyl free radical) and the FRAP (ferric reducing antioxidant power) assay, with the activities exceeding those of well-known antioxidants, namely the flavonoids. The chloroform extract and ramentaceone showed no antioxidative properties. PMID:18782083

  1. Enhanced active metabolite generation and platelet inhibition with prasugrel compared to clopidogrel regardless of genotype in thienopyridine metabolic pathways.

    PubMed

    Braun, Oscar Ö; Angiolillo, Dominick J; Ferreiro, Jose L; Jakubowski, Joseph A; Winters, Kenneth J; Effron, Mark B; Duvvuru, Suman; Costigan, Timothy M; Sundseth, Scott; Walker, Joseph R; Saucedo, Jorge F; Kleiman, Neal S; Varenhorst, Christoph

    2013-12-01

    Clopidogrel response varies according to the presence of genetic polymorphisms. The CYP2C19*2 allele has been associated with impaired response; conflicting results have been reported for CYP2C19*17, ABCB1, and PON1 genotypes. We assessed the impact of CYP2C19, PON1, and ABCB1 polymorphisms on clopidogrel and prasugrel pharmacodynamic (PD) and pharmacokinetic (PK) parameters. Aspirin-treated patients (N=194) with coronary artery disease from two independent, prospective, randomised, multi-centre studies comparing clopidogrel (75 mg) and prasugrel (10 mg) were genotyped and classified by predicted CYP2C19 metaboliser phenotype (ultra metabolisers [UM] = *17 carriers; extensive metabolisers [EM] = *1/1 homozygotes; reduced metabolisers [RM] = *2 carriers). ABCB1 T/T and C/T polymorphisms and PON1 A/A, A/G and G/G polymorphisms were also genotyped. PD parameters were assessed using VerifyNow® P2Y12 and vasodilator stimulated phosphoprotein (VASP) expressed as platelet reactivity index (PRI) after 14 days of maintenance dosing. Clopidogrel and prasugrel active metabolite (AM) exposure was calculated in a cohort of 96 patients. For clopidogrel, genetic variants in CYP2C19, but not ABCB1 or PON1, affected PK and PD. For prasugrel, none of the measured genetic variants affected PK or PD. Compared with clopidogrel, platelet inhibition with prasugrel was greater even in the CYP2C19 UM phenotype. Prasugrel generated more AM and achieved greater platelet inhibition than clopidogrel irrespective of CYP2C19, ABCB1, and PON1 polymorphisms. The lack of effect from genetic variants on prasugrel AM generation or antiplatelet activity is consistent with previous studies in healthy volunteers and is consistent with improved efficacy in acute coronary syndrome patients managed with percutaneous coronary intervention. PMID:24009042

  2. Metabolic activation of tris(2,3-dibromopropyl)phosphate to reactive intermediates. I. Covalent binding and reactive metabolite formation in vitro.

    PubMed

    Pearson, P G; Omichinski, J G; McClanahan, R H; Søderlund, E J; Dybing, E; Nelson, S D

    1993-02-01

    Analogs of tris(2,3-dibromopropyl)phosphate (Tris-BP) either labeled at specific positions with carbon-14, phosphorus-32, or oxygen-18 or dual-labeled with both deuterium and tritium were used as metabolic probes to study the chemical and metabolic events in the bioactivation of Tris-BP to chemically reactive metabolites in liver microsomal preparations. Oxidation at the terminal (C-3) carbon atom of the propyl groups of Tris-BP yielded the direct-acting mutagen 2-bromoacrolein as the major metabolite that binds to DNA. Although this reactive metabolite also appears to bind to microsomal protein, the rate of binding of radiolabeled Tris-BP to protein is 15-20x greater than binding to DNA, and some metabolites that retain the phosphate group are bound. Studies with deuterated analogs of Tris-BP implicate oxidation at C-2 of the propyl group as a major pathway that leads to protein binding which is enhanced by phenobarbital pretreatment of rats. Moreover, investigations with 18O-Tris-BP and H2(18)O show that Bis-BP that is formed from oxidation of Tris-BP incorporates one atom of oxygen from water. Deuterium isotope studies suggest that most of the Bis-BP arises from initial oxidation at C-2. Taken together these studies indicate that P-450 oxidation of Tris-BP at C-2 of the propyl group yields a reactive alpha-bromoketone metabolite of Tris-BP that can either alkylate proteins directly or be hydrolyzed to Bis-BP and an alpha-bromo-alpha'-hydroxyketone that can alkylate microsomal proteins. PMID:8441997

  3. Optically active surfaces formed by ion implantation and thermal treatment

    SciTech Connect

    Gea, L.A.; Boatner, L.A.; Evans, H.M.; Zuhr, R.

    1996-08-01

    Embedded VO{sub 2} precipitates have been formed in single-crystal sapphire by the ion co-implantation of vanadium and oxygen and subsequent thermal annealing. The embedded VO{sub 2} particles have been shown to exhibit an optical switching behavior that is comparable to that of continuous thin films. In this work, the mechanisms of formation of these optically active particles are investigated. It is shown that precipitation of the vanadium dioxide phase is favored when the thermal treatment is performed on an ion-damaged but still crystalline (rather than amorphized) Al{sub 2}O{sub 3} substrate. The best optical switching behavior is observed in this case, and this behavior is apparently correlated with a more-favorable dispersion of VO{sub 2} small particles inside the matrix.

  4. Chemical Fingerprints of Star Forming Regions and Active Galaxies

    NASA Astrophysics Data System (ADS)

    Pérez-Beaupuits, Juan-Pablo

    2010-10-01

    This thesis is devoted to the study of the physical conditions of the interstellar medium (ISM) in active galactic nuclei (AGNs) and Galactic star-forming regions, using mostly single-dish millimeter observations. I first study the excitation conditions of dense gas in a group of Seyfert galaxies using radiative transfer models (Chapter 2). I then study the galaxy NGC 1068, and try to distinguish signatures of the contributions from the AGN and the starburst ring by incorporating observations of high-J transitions of dense gas tracers (Chapter 3). Later, I venture into the mid-infrared spectral region to study different aspects of the AGN and starburst components in the galaxy NGC 4945 (Chapter 4). In Chapter 5 I delve into theoretical aspects of the dynamical evolution of gas in an AGN torus. I use a 3D hydrodynamic simulation with chemical abundances driven by X-rays. The aim is to understand the effects of X-ray irradiation by the AGN on the temperature, formation and destruction of the molecular gas. I finally explore a Galactic star-forming region, the Omega Nebula, with high resolution single dish observations, to study the properties of the warm gas and to constrain chemical models (Chapters 6 and 7).

  5. 75 FR 16492 - Agency Information Collection Activities: Form G-28, and Form G-28I, Revision of an Existing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form G-28, and Form G- 28I, Revision of an Existing Information Collection; Comment Request ACTION: 60-Day Notice of Information Collection under Review: Form G- 28, Notice of Entry of Appearance as Attorney or...

  6. Secondary metabolites from Ganoderma.

    PubMed

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

    2015-06-01

    Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. PMID:25975187

  7. Network Analysis of Enzyme Activities and Metabolite Levels and Their Relationship to Biomass in a Large Panel of Arabidopsis Accessions[C][W][OA

    PubMed Central

    Sulpice, Ronan; Trenkamp, Sandra; Steinfath, Matthias; Usadel, Bjorn; Gibon, Yves; Witucka-Wall, Hanna; Pyl, Eva-Theresa; Tschoep, Hendrik; Steinhauser, Marie Caroline; Guenther, Manuela; Hoehne, Melanie; Rohwer, Johann M.; Altmann, Thomas; Fernie, Alisdair R.; Stitt, Mark

    2010-01-01

    Natural genetic diversity provides a powerful resource to investigate how networks respond to multiple simultaneous changes. In this work, we profile maximum catalytic activities of 37 enzymes from central metabolism and generate a matrix to investigate species-wide connectivity between metabolites, enzymes, and biomass. Most enzyme activities change in a highly coordinated manner, especially those in the Calvin-Benson cycle. Metabolites show coordinated changes in defined sectors of metabolism. Little connectivity was observed between maximum enzyme activities and metabolites, even after applying multivariate analysis methods. Measurements of posttranscriptional regulation will be required to relate these two functional levels. Individual enzyme activities correlate only weakly with biomass. However, when they are used to estimate protein abundances, and the latter are summed and expressed as a fraction of total protein, a significant positive correlation to biomass is observed. The correlation is additive to that obtained between starch and biomass. Thus, biomass is predicted by two independent integrative metabolic biomarkers: preferential investment in photosynthetic machinery and optimization of carbon use. PMID:20699391

  8. Target interaction profiling of midostaurin and its metabolites in neoplastic mast cells predicts distinct effects on activation and growth

    PubMed Central

    Peter, Barbara; Winter, Georg E.; Blatt, Katharina; Bennett, Keiryn L.; Stefanzl, Gabriele; Rix, Uwe; Eisenwort, Gregor; Hadzijusufovic, Emir; Gridling, Manuela; Dutreix, Catherine; Hoermann, Gregor; Schwaab, Juliana; Radia, Deepti; Roesel, Johannes; Manley, Paul W.; Reiter, Andreas; Superti-Furga, Giulio; Valent, Peter

    2016-01-01

    Proteomic-based drug testing is an emerging approach to establish the clinical value and anti-neoplastic potential of multi-kinase inhibitors. The multikinase inhibitor midostaurin (PKC412) is a promising new agent used to treat patients with advanced systemic mastocytosis (SM). We examined the target interaction-profiles and the mast cell (MC)-targeting effects of two pharmacologically relevant midostaurin metabolites, CGP52421 and CGP62221. All three compounds, midostaurin and the two metabolites, suppressed IgE-dependent histamine secretion in basophils and MC with reasonable IC50 values. Midostaurin and CGP62221 also produced growth-inhibition and dephosphorylation of KIT in the MC leukemia cell line HMC-1.2, whereas the second metabolite, CGP52421, that accumulates in vivo, showed no substantial effects. Chemical proteomic profiling and drug-competition experiments revealed that midostaurin interacts with KIT and several additional kinase-targets. The key downstream-regulator FES was recognized by midostaurin and CGP62221, but not by CGP52421 in MC lysates, whereas the IgE-receptor-downstream target SYK was recognized by both metabolites. Together, our data show that the clinically relevant midostaurin metabolite CGP52421 inhibits IgE-dependent histamine release, but is a weak inhibitor of MC proliferation which may have clinical implications and may explain why mediator-related symptoms improve in SM patients even when disease progression occurs. PMID:26349526

  9. Target interaction profiling of midostaurin and its metabolites in neoplastic mast cells predicts distinct effects on activation and growth.

    PubMed

    Peter, B; Winter, G E; Blatt, K; Bennett, K L; Stefanzl, G; Rix, U; Eisenwort, G; Hadzijusufovic, E; Gridling, M; Dutreix, C; Hoermann, G; Schwaab, J; Radia, D; Roesel, J; Manley, P W; Reiter, A; Superti-Furga, G; Valent, P

    2016-02-01

    Proteomic-based drug testing is an emerging approach to establish the clinical value and anti-neoplastic potential of multikinase inhibitors. The multikinase inhibitor midostaurin (PKC412) is a promising new agent used to treat patients with advanced systemic mastocytosis (SM). We examined the target interaction profiles and the mast cell (MC)-targeting effects of two pharmacologically relevant midostaurin metabolites, CGP52421 and CGP62221. All three compounds, midostaurin and the two metabolites, suppressed IgE-dependent histamine secretion in basophils and MC with reasonable IC(50) values. Midostaurin and CGP62221 also produced growth inhibition and dephosphorylation of KIT in the MC leukemia cell line HMC-1.2, whereas the second metabolite, CGP52421, which accumulates in vivo, showed no substantial effects. Chemical proteomic profiling and drug competition experiments revealed that midostaurin interacts with KIT and several additional kinase targets. The key downstream regulator FES was recognized by midostaurin and CGP62221, but not by CGP52421 in MC lysates, whereas the IgE receptor downstream target SYK was recognized by both metabolites. Together, our data show that the clinically relevant midostaurin metabolite CGP52421 inhibits IgE-dependent histamine release, but is a weak inhibitor of MC proliferation, which may have clinical implications and may explain why mediator-related symptoms improve in SM patients even when disease progression occurs. PMID:26349526

  10. Synergistic action of the benzene metabolite hydroquinone on myelopoietic stimulating activity of granulocyte/macrophage colony-stimulating factor in vitro

    NASA Technical Reports Server (NTRS)

    Irons, R. D.; Stillman, W. S.; Colagiovanni, D. B.; Henry, V. A.; Clarkson, T. W. (Principal Investigator)

    1992-01-01

    The effects of in vitro pretreatment with benzene metabolites on colony-forming response of murine bone marrow cells stimulated with recombinant granulocyte/macrophage colony-stimulating factor (rGM-CSF) were examined. Pretreatment with hydroquinone (HQ) at concentrations ranging from picomolar to micromolar for 30 min resulted in a 1.5- to 4.6-fold enhancement in colonies formed in response to rGM-CSF that was due to an increase in granulocyte/macrophage colonies. The synergism equaled or exceeded that reported for the effects of interleukin 1, interleukin 3, or interleukin 6 with GM-CSF. Optimal enhancement was obtained with 1 microM HQ and was largely independent of the concentration of rGM-CSF. Pretreatment with other authentic benzene metabolites, phenol and catechol, and the putative metabolite trans, trans-muconaldehyde did not enhance growth factor response. Coadministration of phenol and HQ did not enhance the maximal rGM-CSF response obtained with HQ alone but shifted the optimal concentration to 100 pM. Synergism between HQ and rGM-CSF was observed with nonadherent bone marrow cells and lineage-depleted bone marrow cells, suggesting an intrinsic effect on recruitment of myeloid progenitor cells not normally responsive to rGM-CSF. Alterations in differentiation in a myeloid progenitor cell population may be of relevance in the pathogenesis of acute myelogenous leukemia secondary to drug or chemical exposure.

  11. Synergistic action of the benzene metabolite hydroquinone on myelopoietic stimulating activity of granulocyte/macrophage colony-stimulating factor in vitro.

    PubMed Central

    Irons, R D; Stillman, W S; Colagiovanni, D B; Henry, V A

    1992-01-01

    The effects of in vitro pretreatment with benzene metabolites on colony-forming response of murine bone marrow cells stimulated with recombinant granulocyte/macrophage colony-stimulating factor (rGM-CSF) were examined. Pretreatment with hydroquinone (HQ) at concentrations ranging from picomolar to micromolar for 30 min resulted in a 1.5- to 4.6-fold enhancement in colonies formed in response to rGM-CSF that was due to an increase in granulocyte/macrophage colonies. The synergism equaled or exceeded that reported for the effects of interleukin 1, interleukin 3, or interleukin 6 with GM-CSF. Optimal enhancement was obtained with 1 microM HQ and was largely independent of the concentration of rGM-CSF. Pretreatment with other authentic benzene metabolites, phenol and catechol, and the putative metabolite trans, trans-muconaldehyde did not enhance growth factor response. Coadministration of phenol and HQ did not enhance the maximal rGM-CSF response obtained with HQ alone but shifted the optimal concentration to 100 pM. Synergism between HQ and rGM-CSF was observed with nonadherent bone marrow cells and lineage-depleted bone marrow cells, suggesting an intrinsic effect on recruitment of myeloid progenitor cells not normally responsive to rGM-CSF. Alterations in differentiation in a myeloid progenitor cell population may be of relevance in the pathogenesis of acute myelogenous leukemia secondary to drug or chemical exposure. PMID:1570288

  12. Volatile Metabolites

    PubMed Central

    Rowan, Daryl D.

    2011-01-01

    Volatile organic compounds (volatiles) comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals) both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites. PMID:24957243

  13. Biochemical Characterization of the Active Anti-Hepatitis C Virus Metabolites of 2,6-Diaminopurine Ribonucleoside Prodrug Compared to Sofosbuvir and BMS-986094.

    PubMed

    Ehteshami, Maryam; Tao, Sijia; Ozturk, Tugba; Zhou, Longhu; Cho, Jong Hyun; Zhang, Hongwang; Amiralaei, Sheida; Shelton, Jadd R; Lu, Xiao; Khalil, Ahmed; Domaoal, Robert A; Stanton, Richard A; Suesserman, Justin E; Lin, Biing; Lee, Sam S; Amblard, Franck; Whitaker, Tony; Coats, Steven J; Schinazi, Raymond F

    2016-08-01

    Ribonucleoside analog inhibitors (rNAI) target the hepatitis C virus (HCV) RNA-dependent RNA polymerase nonstructural protein 5B (NS5B) and cause RNA chain termination. Here, we expand our studies on β-d-2'-C-methyl-2,6-diaminopurine-ribonucleotide (DAPN) phosphoramidate prodrug 1 (PD1) as a novel investigational inhibitor of HCV. DAPN-PD1 is metabolized intracellularly into two distinct bioactive nucleoside triphosphate (TP) analogs. The first metabolite, 2'-C-methyl-GTP, is a well-characterized inhibitor of NS5B polymerase, whereas the second metabolite, 2'-C-methyl-DAPN-TP, behaves as an adenosine base analog. In vitro assays suggest that both metabolites are inhibitors of NS5B-mediated RNA polymerization. Additional factors, such as rNAI-TP incorporation efficiencies, intracellular rNAI-TP levels, and competition with natural ribonucleotides, were examined in order to further characterize the potential role of each nucleotide metabolite in vivo Finally, we found that although both 2'-C-methyl-GTP and 2'-C-methyl-DAPN-TP were weak substrates for human mitochondrial RNA (mtRNA) polymerase (POLRMT) in vitro, DAPN-PD1 did not cause off-target inhibition of mtRNA transcription in Huh-7 cells. In contrast, administration of BMS-986094, which also generates 2'-C-methyl-GTP and previously has been associated with toxicity in humans, caused detectable inhibition of mtRNA transcription. Metabolism of BMS-986094 in Huh-7 cells leads to 87-fold higher levels of intracellular 2'-C-methyl-GTP than DAPN-PD1. Collectively, our data characterize DAPN-PD1 as a novel and potent antiviral agent that combines the delivery of two active metabolites. PMID:27216050

  14. Assessment of adrenocortical activity by non-invasive measurement of faecal cortisol metabolites in dromedary camels (Camelus dromedarius).

    PubMed

    Sid-Ahmed, Omer-Elfaroug; Sanhouri, Ahmed; Elwaseela, Badr-Eldin; Fadllalah, Imad; Mohammed, Galal-Eldin Elazhari; Möstl, Erich

    2013-08-01

    The aim of this study was to determine whether glucocorticoid production could be monitored non-invasively in dromedary camels by measuring faecal cortisol metabolites (FCMs). Five Sudanese dromedaries, two males and three females, were injected with a synthetic adrenocorticotropic hormone (ACTH) analogue. Blood samples were collected pre- and post-ACTH injection. Faeces were sampled after spontaneous defecation for five consecutive days (2 days before and 3 days after ACTH injection). Baseline plasma cortisol values ranged from 0.6 to 10.8 ng/ml in males and from 1.1 to 16.6 ng/ml in females, while peak values after ACTH injection were 10.9-41.9 in males and 10-42.2 ng/ml in females. Peak blood cortisol values were reached between 1.5 and 2.0 h after ACTH injection. The concentration of FCMs increased after ACTH injection in the faeces of both sexes, although steroid levels peaked earlier in males [24 h; (286.7-2,559.7 ng/g faeces)] than in females [36-48 h; (1,182.6-5,169.1 ng/g faeces)], reflecting increases of 3.1-8.3- and 4.3-8-fold above baseline levels. To detect chromatographic patterns of immunoreactive FCMs, faecal samples with high FCM concentrations from both sexes were pooled and subjected to reverse phase high performance liquid chromatography (RP-HPLC). RP-HPLC analysis revealed sex differences in the polarity of FCMs, with females showing more polar FCMs than males. We concluded that stimulation of adrenocortical activity by ACTH injection resulted in a measurable increase in blood cortisol that was reliably paralleled by increases in FCM levels. Thus, measurement of FCMs is a powerful tool for monitoring the adrenocortical responses of dromedaries to stressors in field conditions. PMID:23430659

  15. Effect of bovine ABCG2 Y581S polymorphism on concentrations in milk of enrofloxacin and its active metabolite ciprofloxacin.

    PubMed

    Otero, J A; García-Mateos, D; de la Fuente, A; Prieto, J G; Álvarez, A I; Merino, G

    2016-07-01

    The ATP-binding cassette transporter G2 (ABCG2) is involved in the secretion of several drugs into milk. The bovine Y581S ABCG2 polymorphism increases the secretion into milk of the fluoroquinolone danofloxacin in Holstein cows. Danofloxacin and enrofloxacin are the fluoroquinolones most widely used in veterinary medicine. Both enrofloxacin (ENRO) and its active metabolite ciprofloxacin (CIPRO) reach milk at relatively high concentrations. The aim of this work was to study the effect of the bovine Y581S ABCG2 polymorphism on in vitro transport as well as on concentrations in plasma and in milk of ENRO and CIPRO. Experiments using cells overexpressing bovine ABCG2 showed the effects of ABCG2 on the transport of CIPRO, demonstrating more efficient in vitro transport of this antimicrobial by the S581 variant as compared with the Y581 variant. Animal studies administering 2.5mg/kg of ENRO subcutaneously to Y/Y 581 and Y/S 581 cows revealed that concentrations in plasma of ENRO and CIPRO were significantly lower in Y/S animals. Regardless of the genotype, the antimicrobial profile in milk after the administration of ENRO was predominantly of CIPRO. With respect to the genotype effects on the amounts of drugs present in milk, AUC0-24 values were more than 1.2 times higher in Y/S cows for ENRO and 2.2 times for CIPRO, indicating a greater capacity of Y581S to transfer these drugs into milk. These results emphasize the clinical relevance of this polymorphism as a factor affecting the concentrations in plasma and in milk of drugs of importance in veterinary medicine. PMID:27157572

  16. Microbial transformation of 20(S)-protopanaxadiol by Absidia corymbifera. Cytotoxic activity of the metabolites against human prostate cancer cells.

    PubMed

    Chen, Guangtong; Yang, Min; Nong, Shaojun; Yang, Xue; Ling, Yong; Wang, Donggeng; Wang, Xinyang; Zhang, Wei

    2013-01-01

    Biotransformation of 20(S)-protopanaxadiol (1) by the fungus Absidia corymbifera AS 3.3387 yielded five metabolites (2-6). On the basis of spectroscopic data analyses, the metabolites were identified as 26-hydroxyl-20(S)-protopanaxadiol (2), 23, 24-en-25-hydroxyl-20(S)-protopanaxadiol (3), 25-hydroxyl-20(S)-protopanaxadiol (4), 7β-hydroxyl-20(S)-protopanaxatriol (5), and 7-oxo-20(S)-protopanaxatriol (6), respectively. Among them, 5 and 6 are new compounds. These results indicated that A. corymbifera AS 3.3387 could catalyze the side-chain oxidation-reduction, 7β hydroxylation, and the specific C-7 dehydrogenation of derivatives of 20(S)-protopanaxadiol. The metabolites 2, 5, and 6 showed the more potent inhibitory effects against DU-145 and PC-3 cell lines than the substrate. PMID:23022533

  17. Hesperidin metabolite hesperetin-7-O-glucuronide, but not hesperetin-3'-O-glucuronide, exerts hypotensive, vasodilatory, and anti-inflammatory activities.

    PubMed

    Yamamoto, Masaki; Jokura, Hiroko; Hashizume, Koujiro; Ominami, Hideo; Shibuya, Yusuke; Suzuki, Atsushi; Hase, Tadashi; Shimotoyodome, Akira

    2013-09-01

    Orally ingested hesperidin (HES) is hydrolyzed into hesperetin in the gastrointestinal tract and conjugated during absorption. Hesperetin conjugates are the main circulating metabolites in human and rat plasma. We previously reported that glucosyl hesperidin (GHES), a water-soluble HES derivative, prevents hypertension via improvement of endothelial dysfunction in spontaneously hypertensive rats (SHRs). Although these hesperetin conjugates seem to be responsible for hypotensive and endothelium-dependent vasodilatory activities of dietary GHES, little is known about the mechanisms of action of these conjugated metabolites. Therefore, the aim of the present study was to investigate the effects of hesperetin-7-O-β-d-glucuronide (HPT7G) and hesperetin-3'-O-β-d-glucuronide (HPT3'G), which are the predominant HES metabolites in rat plasma, on blood pressure and endothelial function. Intravenous administration of HPT7G (5 mg kg(-1)) decreased blood pressure in anesthetized SHRs. HPT7G enhanced endothelium-dependent vasodilation in response to acetylcholine, but had no effect on endothelium-independent vasodilation in response to sodium nitroprusside (SNP) in aortas isolated from SHRs. HPT7G decreased hydrogen peroxide-induced intracellular adhesion molecule-1 and monocyte chemoattractant protein-1 mRNA expression in rat aortic endothelial cells. In contrast, HPT3'G had little effect on these parameters. In conclusion, HPT7G exerted hypotensive, vasodilatory and anti-inflammatory activities, similar to hesperetin and these effects are associated, in part, with the activity of GHES and HES to improve hypertension and endothelial dysfunction. PMID:23831969

  18. Acute HCV/HIV Coinfection Is Associated with Cognitive Dysfunction and Cerebral Metabolite Disturbance, but Not Increased Microglial Cell Activation

    PubMed Central

    Garvey, Lucy J.; Pavese, Nicola; Ramlackhansingh, Anil; Thomson, Emma; Allsop, Joanna M.; Politis, Marios; Kulasegaram, Ranjababu; Main, Janice; Brooks, David J.; Taylor-Robinson, Simon D.; Winston, Alan

    2012-01-01

    Background Microglial cell activation and cerebral function impairment are described in both chronic hepatitis C viral (HCV) and Human-Immune-Deficiency viral (HIV) infections. The aim of this study was to investigate the effect of acute HCV infection upon cerebral function and microglial cell activation in HIV-infected individuals. Methods A case-control study was conducted. Subjects with acute HCV and chronic HIV coinfection (aHCV) were compared to matched controls with chronic HIV monoinfection (HIVmono). aHCV was defined as a new positive plasma HCV RNA within 12 months of a negative RNA test. Subjects underwent neuro-cognitive testing (NCT), cerebral proton magnetic resonance spectroscopy (1H-MRS) and positron emission tomography (PET) using a 11C-radiolabeled ligand (PK11195), which is highly specific for translocator protein 18 kDA receptors on activated microglial cells. Differences between cases and controls were assessed using linear regression modelling. Results Twenty-four aHCV cases completed NCT and 1H-MRS, 8 underwent PET. Of 57 HIVmono controls completing NCT, 12 underwent 1H-MRS and 8 PET. Subjects with aHCV demonstrated on NCT, significantly poorer executive function (mean (SD) error rate 26.50(17.87) versus 19.09(8.12), p = 0.001) and on 1H-MRS increased myo-inositol/creatine ratios (mI/Cr, a marker of cerebral inflammation) in the basal ganglia (ratio of 0.71(0.22) versus 0.55(0.23), p = 0.03), compared to subjects with HIVmono. On PET imaging, no difference in 11C-PK11195 binding potential (BP) was observed between study groups (p>0.10 all cerebral locations), however lower BPs were associated with combination antiretroviral therapy (cART) use in the parietal (p = 0.01) and frontal (p = 0.03) cerebral locations. Discussion Poorer cognitive performance and disturbance of cerebral metabolites are observed in subjects with aHC,V compared to subjects with HIVmono. Higher 11C-PK11195 BP was not observed in subjects with aHCV, but was

  19. The relationship of nitrogen and C/N ratio with secondary metabolites levels and antioxidant activities in three varieties of Malaysian kacip Fatimah (Labisia pumila Blume).

    PubMed

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E

    2011-01-01

    Kacip Fatimah (Labisia pumila Blume), one of the most famous and widely used herbs, especially in Southeast Asia, is found to have interesting bioactive compounds and displays health promoting properties. In this study, the antioxidant activities of the methanol extracts of leaves, stems and roots of three varieties of L. pumila (var. alata, pumila and lanceolata) were evaluated in an effort to compare and validate the medicinal potential of this indigenous Malaysian herb species. The antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, as well as the total amount of phenolics and flavonoids were the highest in the leaves, followed by the stems and roots in all the varieties. A similar trend was displayed by the ferric reducing antioxidant potential (FRAP) activity, suggesting that the L. pumila varieties possess high foliar antioxidant properties. At low FRAP activity concentrations, the values of the leaves' inhibition activity in the three varieties were significantly higher than those of the stems and roots, with var. alata exhibiting higher antioxidant activities and total contents of phenolics and flavonoids compared to the varieties pumila and lanceolata. The high production of secondary metabolites and antioxidant activities in var. alata were firmly related to low nitrogen content and high C/N ratio in plant parts. The study also demonstrated a positive correlation between secondary metabolite content and antioxidant activities, and revealed that the consumption of L. pumila could exert several beneficial effects by virtue of its antioxidant activity. PMID:21716173

  20. Biological Activity of 1α-Hydroxycholecalciferol, A Synthetic Analog of the Hormonal Form of Vitamin D3

    PubMed Central

    Haussler, Mark R.; Zerwekh, Joseph E.; Hesse, Robert H.; Rizzardo, E.; Pechet, Maurice M.

    1973-01-01

    1,25-Dihydroxycholecalciferol, the apparent active hormonal form of cholecalciferol (vitamin D2), is formed from cholecalciferol by specific and sequential hydroxylations of the sterol at carbons 25 and 1. Recently, 1α-hydroxycholecalciferol was synthesized and we report on its biological activity in rachitic chicks. 1α-Hydroxycholecalciferol is identical in potency to 1,25-dihydroxycholecalciferol in stimulation of intestinal calcium absorption; either sterol elicits a near maximal effect at a dose of 0.3-0.6 nmol. The time-course of action of 1α-hydroxycholecalciferol also parallels that of the active metabolite 1,25-dihydroxycholecalciferol with a maximal increase in calcium transport occurring 5-10 hr after administration of sterol to vitamin D-deficient chicks. 6.5 nmol of 1α-hydroxycholecalciferol causes a doubling in calcium absorption in only 2-3 hr, which is the most rapid physiologic response yet detected for a vitamin D-sterol. 1α-Hydroxycholecalciferol is active also in enhancing bone calcium resorption and, like 1,25-dihydroxycholecalciferol, is at least 10 times as active as cholecalciferol in mobilizing bone calcium and raising plasma calcium concentration. It is concluded that 1α-hydroxycholecalciferol represents a synthetic analog of 1,25-dihydroxycholecalciferol that can be used both to study the mechanism of action of this hormone and as a therapeutic agent in the treatment of patients with certain metabolic bone diseases. PMID:4365368

  1. Distribution of topical ocular nepafenac and its active metabolite amfenac to the posterior segment of the eye.

    PubMed

    Chastain, James E; Sanders, Mark E; Curtis, Michael A; Chemuturi, Nagendra V; Gadd, Martha E; Kapin, Michael A; Markwardt, Kerry L; Dahlin, David C

    2016-04-01

    Nepafenac ophthalmic suspensions, 0.1% (NEVANAC(®)) and 0.3% (ILEVRO™), are topical nonsteroidal anti-inflammatory drug (NSAID) products approved in the United States, Europe and various other countries to treat pain and inflammation associated with cataract surgery. NEVANAC is also approved in Europe for the reduction in the risk of postoperative macular edema (ME) associated with cataract surgery in diabetic patients. The efficacy against ME suggests that topical administration leads to distribution of nepafenac or its active metabolite amfenac to the posterior segment of the eye. This article evaluates the ocular distribution of nepafenac and amfenac and the extent of local delivery to the posterior segment of the eye, following topical ocular instillation in animal models. Nepafenac ophthalmic suspension was instilled unilaterally in New Zealand White rabbits as either a single dose (0.1%; one drop) or as multiple doses (0.3%, one drop, once-daily for 4 days, or 0.1% one drop, three-times daily for 3 days and one morning dose on day 4). Nepafenac (0.3%) was also instilled unilaterally in cynomolgus monkeys as multiple doses (one drop, three-times daily for 7 days). Nepafenac and amfenac concentrations in harvested ocular tissues were measured using high-performance liquid chromatography/mass spectrometry. Locally-distributed compound concentrations were determined as the difference in levels between dosed and undosed eyes. In single-dosed rabbit eyes, peak concentrations of locally-distributed nepafenac and amfenac showed a trend of sclera > choroid > retina. Nepafenac peak levels in sub-samples posterior to the eye equator and inclusive of the posterior pole (E-PP) were 55.1, 4.03 and 2.72 nM, respectively, at 0.25 or 0.50 h, with corresponding amfenac peak levels of 41.9, 3.10 and 0.705 nM at 1 or 4 h. By comparison, peak levels in sclera, choroid and retina sub-samples in a band between the ora serrata and the equator (OS-E) were 13- to 40-fold

  2. Comparative Error-Free and Error-Prone Translesion Synthesis of N(2)-2'-Deoxyguanosine Adducts Formed by Mitomycin C and Its Metabolite, 2,7-Diaminomitosene, in Human Cells.

    PubMed

    Bose, Arindam; Surugihalli, Chaitra; Pande, Paritosh; Champeil, Elise; Basu, Ashis K

    2016-05-16

    Mitomycin C (MC) is a cytotoxic and mutagenic antitumor agent that alkylates DNA upon reductive activation. 2,7-Diaminomitosene (2,7-DAM) is a major metabolite of MC in tumor cells, which also alkylates DNA. MC forms seven DNA adducts, including monoadducts and inter- and intrastrand cross-links, whereas 2,7-DAM forms two monoadducts. Herein, the biological effects of the dG-N(2) adducts formed by MC and 2,7-DAM have been compared by constructing single-stranded plasmids containing these adducts and replicating them in human embryonic kidney 293T cells. Translesion synthesis (TLS) efficiencies of dG-N(2)-MC and dG-N(2)-2,7-DAM were 38 ± 3 and 27 ± 3%, respectively, compared to that of a control plasmid. This indicates that both adducts block DNA synthesis and that dG-N(2)-2,7-DAM is a stronger replication block than dG-N(2)-MC. TLS of each adducted construct was reduced upon siRNA knockdown of pol η, pol κ, or pol ζ. For both adducts, the most significant reduction occurred with knockdown of pol κ, which suggests that pol κ plays a major role in TLS of these dG-N(2) adducts. Analysis of the progeny showed that both adducts were mutagenic, and the mutation frequencies (MF) of dG-N(2)-MC and dG-N(2)-2,7-DAM were 18 ± 3 and 10 ± 1%, respectively. For both adducts, the major type of mutation was G → T transversions. Knockdown of pol η and pol ζ reduced the MF of dG-N(2)-MC and dG-N(2)-2,7-DAM, whereas knockdown of pol κ increased the MF of these adducts. This suggests that pol κ predominantly carries out error-free TLS, whereas pol η and pol ζ are involved in error-prone TLS. The largest reduction in MF by 78 and 80%, respectively, for dG-N(2)-MC and dG-N(2)-2,7-DAM constructs occurred when pol η, pol ζ, and Rev1 were simultaneously knocked down. This result strongly suggests that, unlike pol κ, these three TLS polymerases cooperatively perform the error-prone TLS of these adducts. PMID:27082015

  3. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause toll-like receptor 4 activation and enhanced pain.

    PubMed

    Lewis, Susannah S; Hutchinson, Mark R; Zhang, Yingning; Hund, Dana K; Maier, Steven F; Rice, Kenner C; Watkins, Linda R

    2013-05-01

    We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex previously characterized as the docking site for morphine-3-glucuronide. Glucuronic acid, ethyl glucuronide and ethanol all caused an increase in TLR4-dependent reporter protein expression in a cell line transfected with TLR4 and associated co-signaling molecules. Glucuronic acid-, ethyl glucuronide-, and ethanol-induced increases in TLR4 signaling were blocked by the TLR4 antagonists LPS-RS and (+)-naloxone. Glucuronic acid and ethyl glucuronide both caused allodynia following intrathecal injection in rats, which was blocked by intrathecal co-administration of the TLR4 antagonist LPS-RS. The finding that ethyl glucuronide can cause TLR4-dependent pain could have implications for human conditions such as hangover headache and alcohol withdrawal hyperalgesia, as well as suggesting that other classes of glucuronide metabolites could have similar effects. PMID:23348028

  4. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause Toll-like receptor 4 activation and enhanced pain

    PubMed Central

    Lewis, Susannah S.; Hutchinson, Mark R.; Zhang, Yingning; Hund, Dana K.; Maier, Steven F.; Rice, Kenner C.; Watkins, Linda R.

    2013-01-01

    We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex previously characterized as the docking site for morphine-3-glucuronide. Glucuronic acid, ethyl glucuronide and ethanol all caused an increase in TLR4-dependent reporter protein expression in a cell line transfected with TLR4 and associated co-signaling molecules. Glucuronic acid-, ethyl glucuronide-, and ethanol-induced increases in TLR4 signaling were blocked by the TLR4 antagonists LPS-RS and (+)-naloxone. Glucuronic acid and ethyl glucuronide both caused allodynia following intrathecal injection in rats, which was blocked by intrathecal co-administration of the TLR4 antagonist LPS-RS. The finding that ethyl glucuronide can cause TLR4-dependent pain could have implications for human conditions such as hangover headache and alcohol withdrawal hyperalgesia, as well as suggesting that other classes of glucuronide metabolites could have similar effects. PMID:23348028

  5. A radioreceptor assay to study the affinity of benzodiazepines and their receptor binding activity in human plasma including their active metabolites.

    PubMed Central

    Dorow, R G; Seidler, J; Schneider, H H

    1982-01-01

    1 A radioreceptor assay has been established to measure the receptor affinities of numerous benzodiazepines in clinical use. 2 The time course of receptor binding activity was studied by this method in the plasma of eight healthy subjects randomly treated with 1 mg lormetazepam (Noctamid, 2 mg flunitrazepam (Rohypnol, and 10 mg diazepam (Valium, and placebo on a cross-over basis. Blood samples were collected up to 154 h after treatment. 3 Receptor affinities of numerous benzodiazepines on vitro show good correlation with therapeutic human doses (r = 0.96) and may be predictive of drug potency in man. 4 Mean peak plasma levels of lormetazepam binding equivalents were 4.8 +/- 1 ng/ml at 2 h after lormetazepam, 7.2 +/- 1.8 ng/ml at 8 h after flunitrazepam, and 17.9 +/- 2.7 ng/ml at 15 h after diazepam. Plasma elimination half-lives of benzodiazepine binding equivalents were 9.3, 23 and 63 h, respectively. 5 Slow elimination of benzodiazepine binding equivalents following flunitrazepam and diazepam may be due to persistent active metabolites. PMID:6121579

  6. Anticancer Effect and Structure-Activity Analysis of Marine Products Isolated from Metabolites of Mangrove Fungi in the South China Sea

    PubMed Central

    Tao, Li-yang; Zhang, Jian-ye; Liang, Yong-ju; Chen, Li-ming; Zhen, Li-sheng; Wang, Fang; Mi, Yan-jun; She, Zhi-gang; To, Kenneth Kin Wah; Lin, Yong-cheng; Fu, Li-wu

    2010-01-01

    Marine-derived fungi provide plenty of structurally unique and biologically active secondary metabolites. We screened 87 marine products from mangrove fungi in the South China Sea for anticancer activity by MTT assay. 14% of the compounds (11/86) exhibited a potent activity against cancer in vitro. Importantly, some compounds such as compounds 78 and 81 appeared to be promising for treating cancer patients with multidrug resistance, which should encourage more efforts to isolate promising candidates for further development as clinically useful chemotherapeutic drugs. Furthermore, DNA intercalation was not involved in their anticancer activities, as determined by DNA binding assay. On the other hand, the structure-activity analysis indicated that the hydroxyl group was important for their cytotoxic activity and that bulky functional groups such as phenyl rings could result in a loss of biological activity, which will direct the further development of marine product-based derivatives. PMID:20479969

  7. A predominate role of CYP1A2 for the metabolism of nabumetone to the active metabolite, 6-methoxy-2-naphthylacetic acid, in human liver microsomes.

    PubMed

    Turpeinen, Miia; Hofmann, Ute; Klein, Kathrin; Mürdter, Thomas; Schwab, Matthias; Zanger, Ulrich M

    2009-05-01

    Nabumetone, a widely used nonsteroidal anti-inflammatory drug, requires biotransformation into 6-methoxy-2-naphthylacetic acid (6-MNA), a close structural analog to naproxen, to achieve its analgesic and anti-inflammatory effects. Despite its wide use, the enzymes involved in metabolism have not been identified. In the present study, several in vitro approaches were used to identify the cytochrome P450 (P450) enzyme(s) responsible for 6-MNA formation. In human liver microsomes (HLMs) 6-MNA formation displayed monophasic Michaelis-Menten kinetics with apparent K(m) and V(max) values (mean +/- S.D.) of 75.1 +/- 15.3 microM and 1304 +/- 226 pmol/min/mg protein, respectively, and formation rate of 6-MNA varied approximately 5.5-fold (179-983 pmol/min/mg protein). 6-MNA activity correlated strongly with both CYP1A2-mediated phenacetin O-deethylation activity and CYP1A2 protein content (r = 0.85 and 0.74, respectively; p < 0.0001 for both). Additional correlations were found with model activities of CYP2C19 and CYP3A4. Of 11 cDNA-expressed recombinant P450s used, recombinant CYP1A2 was the major form catalyzing the 6-MNA formation with an apparent K(m) of 45 microM and V(max) of 8.7 pmol/min/pmol P450. Minor fractions were catalyzed by recombinant P450s CYP1A1, CYP2B6, CYP2C19, CYP2D6, and CYP2E1. Experiments with P450-selective chemical inhibitors and monoclonal anti-P450 antibodies showed that furafylline, a mechanism-based inhibitor CYP1A2, and anti-CYP1A2 antibody markedly inhibited 6-MNA formation, whereas inhibitors for other P450s did not show significant inhibitory effects. Taken together, these studies indicate that the formation of the active metabolite of nabumetone, 6-MNA, is predominantly catalyzed by CYP1A2 in HLMs with only minor contribution of other P450s. PMID:19204080

  8. 76 FR 30738 - Agency Information Collection Activities: Form G-845 and Form G-845 Supplement, Revision of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-26

    ... the Federal Register on February 22, 2011, at 76 FR 9805, allowing for a 60-day public comment period... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form G-845 and Form G- 845 Supplement, Revision of a Currently Approved Information Collection; Comment Request...

  9. Metabolite profiling of enzymatically hydrolyzed and fermented forms of Opuntia ficus-indica and their effect on UVB-induced skin photoaging.

    PubMed

    Cho, Dong-Woon; Kim, Dae-Eung; Lee, Dae-Hee; Jung, Kyung-Hoon; Hurh, Byung-Serk; Kwon, Oh Wook; Kim, Sun Yeou

    2014-01-01

    Fermentation of natural products is emerging as an important processing method and is attracting a lot of attention because it may have the advantage of having a new biological function. In this study, fruits of Opuntia ficus-indica were enzymatically hydrolyzed and then fermented with two species of yeast. We identified novel prominent markers in enzymatically hydrolyzed O. ficus-indica (EO) and fermented O. ficus-indica (FO) samples by using an ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. We also evaluated the effect of EO and FO on photoaging of skin cells exposed to ultraviolet radiation. We identified the major fermented metabolite in the FO as ferulic acid. Our in vitro study indicated that FO significantly enhanced the concentration of pro-collagen type 1 than the EO, by increasing the TGF-β1 production. PMID:24446110

  10. The Essay: Theory and Pedagogy for an Active Form.

    ERIC Educational Resources Information Center

    Heilker, Paul

    Calling for a radical reexamination of the traditional foundation of composition instruction--the thesis/support form, this book argues that the essay, with its informality, conversational tone, meditative mood, and integration of form and content, is better suited to developmental, epistemological, ideological, and feminist rhetorical…

  11. Assessment of estrogenic and anti-androgenic activities of the mycotoxin zearalenone and its metabolites using in vitro receptor-specific bioassays.

    PubMed

    Molina-Molina, José-Manuel; Real, Macarena; Jimenez-Diaz, Inmaculada; Belhassen, Hidaya; Hedhili, Abderazzak; Torné, Pablo; Fernández, Mariana F; Olea, Nicolás

    2014-12-01

    Zearalenone (ZEN) is a well-known mycotoxin present in numerous agricultural products. Humans and animals are therefore at a risk of exposure to zearalenone through consumption of contaminated food. After intake, ZEN is reduced to α- and β-zearalenol (α-ZEL and β-ZEL), zearalanone (ZAN), and α- and β-zearalanol (α-ZAL and β-ZAL). Although their estrogenicity has been well characterized, much less is known about their interaction with other nuclear receptors. This study was undertaken to investigate interactions of ZEN and its five metabolites, with the human androgen receptor (hAR) and estrogen receptor alpha (hERα). Their ability to induce hAR-mediated reporter gene expression was examined in androgen-sensitive PALM cells, whereas the effects on hERα function were assessed in MCF-7 cells using the E-Screen bioassay. We confirm that ZEN and its metabolites are full agonists for hERα and demonstrate that all six compounds tested possess hAR-mediated antagonistic activity in PALM cells, in which ZAN, α-ZAL, and β-ZAL were the most effective hAR antagonists. Overall, the observed estrogenic and anti-androgenic potencies of ZEN and its metabolites suggest that these compounds may interfere with the endocrine system by various modes of action and that further investigation is warranted into their role as endocrine disrupters in animals and humans. PMID:25455890

  12. Marine-derived myxobacteria of the suborder Nannocystineae: An underexplored source of structurally intriguing and biologically active metabolites

    PubMed Central

    Schäberle, Till F

    2016-01-01

    Summary Myxobacteria are famous for their ability to produce most intriguing secondary metabolites. Till recently, only terrestrial myxobacteria were in the focus of research. In this review, however, we discuss marine-derived myxobacteria, which are particularly interesting due to their relatively recent discovery and due to the fact that their very existence was called into question. The to-date-explored members of these halophilic or halotolerant myxobacteria are all grouped into the suborder Nannocystineae. Few of them were chemically investigated revealing around 11 structural types belonging to the polyketide, non-ribosomal peptide, hybrids thereof or terpenoid class of secondary metabolites. A most unusual structural type is represented by salimabromide from Enhygromyxa salina. In silico analyses were carried out on the available genome sequences of four bacterial members of the Nannocystineae, revealing the biosynthetic potential of these bacteria. PMID:27340488

  13. Human serum determination and in vitro anti-inflammatory activity of the vitamin E metabolite α-(13'-hydroxy)-6-hydroxychroman.

    PubMed

    Ciffolilli, Silvia; Wallert, Maria; Bartolini, Desirée; Krauth, Verena; Werz, Oliver; Piroddi, Marta; Sebastiani, Bartolomeo; Torquato, Pierangelo; Lorkowski, Stefan; Birringer, Marc; Galli, Francesco

    2015-12-01

    Cytochrome P450-derived long-chain metabolites are gaining increasing interest as bioactive intermediates of vitamin E. In this study we first report on the HPLC-ECD and GC-MS analysis in human serum of the earliest metabolite of this vitamin, namely α-(13'-hydroxy)-6-hydroxychroman (α-13'-OH). The two chromatographic procedure are sensitive enough (LOQ of 10nM) to measure α-13'-OH after hexane extraction of 1 ml of sample obtained from healthy volunteers supplemented for 1-week with 1000 IU/d (671 mg/d) RRR-α-tocopherol. The observed concentrations ranged between 15 and 50 nM, with minor differences between fasting and 4-hr post-meal state. Baseline (non-supplemented state) levels of 7.2 ± 1.6 nM were observed extracting higher volumes of serum. Biological effects of α-13'-OH investigated for the first time in RAW264.7 murine macrophages involved transcriptional control of inflammatory cytokines, and transcriptional and functional regulation of COX2 and iNOS enzymes in response to lipopolysaccharides. In conclusion, here we present the first quantitative evaluation of serum α-13'-OH also providing early evidence of the anti-inflammatory potential of this metabolite that is worth of further investigation in the area of functional and nutraceutical implications of vitamin E metabolism. PMID:26454076

  14. Extensive sugar modification improves triple helix forming oligonucleotide activity in vitro but reduces activity in vivo.

    PubMed

    Alam, Md Rowshon; Majumdar, Alokes; Thazhathveetil, Arun Kalliat; Liu, Su-Ting; Liu, Ji-Lan; Puri, Nitin; Cuenoud, Bernard; Sasaki, Shigeki; Miller, Paul S; Seidman, Michael M

    2007-09-01

    We are developing triple helix forming oligonucleotides (TFOs) for gene targeting. Previously, we synthesized bioactive TFOs containing 2'-O-methylribose (2'-OMe) and 2'-O-aminoethylribose (2'-AE) residues. Active TFOs contained four contiguous 2'-AE residues and formed triplexes with high thermal stability and rapid association kinetics. In an effort to further improve bioactivity, we synthesized three series of TFOs containing the 2'-AE patch and additional ribose modifications distributed throughout the remainder of the oligonucleotide. These were either additional 2'-AE residues, the conformationally locked BNA/LNA ribose with a 2'-O,4'-C-methylene bridge, or the 2'-O,4'-C-ethylene analogue (ENA). The additionally modified TFOs formed triplexes with greater thermal stability than the reference TFO, and some had improved association kinetics. However, the most active TFOs in the biochemical and biophysical assays were the least active in the bioassay. We measured the thermal stability of triplexes formed by the TFOs in each series on duplex targets containing a change in sequence at a single position. The Tm value of the variant sequence triplexes increased as the number of all additional modifications increased. A simple explanation for the failure of the improved TFOs in the bioassay was that the increased affinity for nonspecific targets lowered the effective nuclear concentration. Enhancement of TFO bioactivity will require chemical modifications that improve interaction with the specific targets while retaining selectivity against mismatched sequences. PMID:17691818

  15. Aspirin metabolites are GPR35 agonists.

    PubMed

    Deng, Huayun; Fang, Ye

    2012-07-01

    Aspirin is widely used as an anti-inflammatory, anti-platelet, anti-pyretic, and cancer-preventive agent; however, the molecular mode of action is unlikely due entirely to the inhibition of cyclooxygenases. Here, we report the agonist activity of several aspirin metabolites at GPR35, a poorly characterized orphan G protein-coupled receptor. 2,3,5-Trihydroxybenzoic acid, an aspirin catabolite, was found to be the most potent GPR35 agonist among aspirin metabolites. Salicyluric acid, the main metabolite of aspirin, was also active. These results suggest that the GPR35 agonist activity of certain aspirin metabolites may contribute to the clinical features of aspirin. PMID:22526472

  16. Tools and ingredients for the biocatalytic synthesis of metabolites.

    PubMed

    Wohlgemuth, Roland

    2009-09-01

    Metabolic networks have been an interesting starting point not only for the design of synthetic routes in a similar sequence of reactions, e.g., in biomimetic syntheses, but also for assembling a number of biocatalytic steps by preparing the required enzymes and auxiliary reagents. Retrosynthetic analysis involving multiple biocatalytic reactions steps therefore needs to consider the practically realized biocatalytic single steps. The opportunities for route selection are enlarged if novel synthetic reactions connecting easily available starting materials and products are found, and/or both biocatalytic and classical reactions of organic chemistry are utilized. Tools and ingredients for biocatalytic synthesis are of special interest for reactions difficult to achieve by classical organic synthesis. Densely and differentially functionalized small molecules do not allow much space for protecting or activating groups. Biocatalytic reactions have therefore performed well for a number of useful metabolites in enantiopure form to achieve full functionality. Although many well-known metabolites from classical biochemistry have only been prepared in racemic form, it is of fundamental interest to have these available in enantiomerically pure form. Biocatalytic reactions with nature's privileged chiral catalysts appear to be a promising synthetic strategy towards these metabolites, especially when sensitive or stable-isotope-labeled metabolites are to be prepared. The main applications for these metabolites are as references materials in metabolomics, as enzyme substrates for the characterization of metabolic enzyme activities and as potential pharmaceuticals in biomedical research. The use of stable-isotope-labeled metabolites can thereby simplify in vivo applications and metabolic flux analyses. PMID:19777483

  17. STYPu fuel form activities, March 1-September 30, 1985

    SciTech Connect

    Not Available

    1986-01-01

    The SRP portion of this report summarizes production STYPuO2 fuel forms for use in radioisotopic thermoelectric generators (RTG's) in the Plutonium Fuel Form (PuFF) Facility at the Savannah River Plant. The PuFF Facility began producing iridium-encapsulated, 62.5-watt STYPuO2 right circular cylinders for GPHS (General Purpose Heat Source) RTG's in June 1980; this program was completed in December 1983. The PuFF Facility has been placed in a production readiness mode of operation pending funding of additional heat source programs.

  18. Functional characterization of the 1,5-benzodiazepine clobazam and its major active metabolite N-desmethylclobazam at human GABA(A) receptors expressed in Xenopus laevis oocytes.

    PubMed

    Hammer, Harriet; Ebert, Bjarke; Jensen, Henrik Sindal; Jensen, Anders A

    2015-01-01

    The 1,5-benzodiazepine clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome in patients 2 years of age or older in the United States, and for treatment of anxiety and various forms of epilepsy elsewhere. Clobazam has been reported to exhibit different in vivo adverse effects and addiction liability profile than the classic 1,4-benzodiazepines. In this study, it was investigated whether the in vitro pharmacological properties of clobazam and its major active metabolite N-desmethylclobazam could explain some of these clinical differences. The functional properties of the two 1,5-benzodiazepines were characterized at the human γ-aminobutyric acid type A receptor (GABA(A)R) subtypes α1β2γ(2S), α2β2γ(2S), α3β2γ(2S), α5β2γ(2S) and α6β2δ expressed in Xenopus laevis oocytes by use of two-electrode voltage-clamp electrophysiology and compared to those exhibited by the 1,4-benzodiazepine clonazepam. All three compounds potentiated GABA EC20-evoked responses through the α(1,2,3,5)β2γ(2S) GABA(A)Rs in a reversible and concentration-dependent manner, with each displaying similar EC50 values at the four subtypes. Furthermore, the degrees of potentiation of the GABA EC20 currents through the four receptors mediated by saturating modulator concentrations did not differ substantially for any of the three benzodiazepines. The three compounds were substantially less potent (200-3900 fold) as positive allosteric modulators at the α6β2δ GABA(A)R than at the α(1,2,3,5)β2γ(2S) receptors. Interestingly, however, clobazam and especially N-desmethylclobazam were highly efficacious potentiators of α6β2δ receptor signaling. Although this activity component is unlikely to contribute to the in vivo effects of clobazam/N-desmethylclobazam, the 1,5-benzodiazepine could constitute an interesting lead for novel modulators targeting this low-affinity binding site in GABAARs. In conclusion, the non-selective modulation

  19. Abscisic acid induced changes in production of primary and secondary metabolites, photosynthetic capacity, antioxidant capability, antioxidant enzymes and lipoxygenase inhibitory activity of Orthosiphon stamineus Benth.

    PubMed

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E

    2013-01-01

    An experiment was conducted to investigate and distinguish the relationships in the production of total phenolics, total flavonoids, soluble sugars, H2O2, O2-, phenylalanine ammonia lyase (PAL) activity, leaf gas exchange, antioxidant activity, antioxidant enzyme activity [ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD) and Lipoxygenase inhibitory activity (LOX)] under four levels of foliar abscisic acid (ABA) application (0, 2, 4, 6 µM) for 15 weeks in Orthosiphon stamineus Benth. It was found that the production of plant secondary metabolites, soluble sugars, antioxidant activity, PAL activity and LOX inhibitory activity was influenced by foliar application of ABA. As the concentration of ABA was increased from 0 to 6 µM the production of total phenolics, flavonoids, sucrose, H2O2, O2-, PAL activity and LOX inhibitory activity was enhanced. It was also observed that the antioxidant capabilities (DPPH and ORAC) were increased. This was followed by increases in production of antioxidant enzymes APX, CAT and SOD. Under high application rates of ABA the net photosynthesis and stomatal conductance was found to be reduced. The production of primary and secondary metabolites displayed a significant positive relationship with H2O2 (total phenolics, r2 = 0.877; total flavonoids, r2 = 0.812; p ≤ 0.05) and O2- (total phenolics, r2 = 0.778; total flavonoids, r2 = 0.912; p ≤ 0.05). This indicated that increased oxidative stress at high application rates of ABA, improved the production of phytochemicals. PMID:23884129

  20. A sensitive radioisotopic method for the measurement of NAD(P)H: Its application to the assay of metabolites and enzymatic activities

    SciTech Connect

    Sener, A.; Malaisse, W.J. )

    1990-05-01

    A radioisotopic method for the assay of NADH or NADPH is presented, which is based on the conversion of 2-(U-{sup 14}C)ketoglutarate to {sup 14}C-labeled glutamate in the reaction catalyzed by glutamate dehydrogenase. The efficiency of the method is close to 75%, its precision (coefficient of variation) close to 5%, and its sensitivity close to 0.1 pmol/sample. This simple and rapid method can be applied to the measurement of several metabolites and enzymatic activities. In the present study, its application to the assay of sorbitol, 3-hydroxybutyrate, glutamate dehydrogenase, 3-hydroxybutyrate dehydrogenase, and glyceraldehyde-3-phosphate dehydrogenase is documented.

  1. A modular modulation method for achieving increases in metabolite production.

    PubMed

    Acerenza, Luis; Monzon, Pablo; Ortega, Fernando

    2015-01-01

    Increasing the production of overproducing strains represents a great challenge. Here, we develop a modular modulation method to determine the key steps for genetic manipulation to increase metabolite production. The method consists of three steps: (i) modularization of the metabolic network into two modules connected by linking metabolites, (ii) change in the activity of the modules using auxiliary rates producing or consuming the linking metabolites in appropriate proportions and (iii) determination of the key modules and steps to increase production. The mathematical formulation of the method in matrix form shows that it may be applied to metabolic networks of any structure and size, with reactions showing any kind of rate laws. The results are valid for any type of conservation relationships in the metabolite concentrations or interactions between modules. The activity of the module may, in principle, be changed by any large factor. The method may be applied recursively or combined with other methods devised to perform fine searches in smaller regions. In practice, it is implemented by integrating to the producer strain heterologous reactions or synthetic pathways producing or consuming the linking metabolites. The new procedure may contribute to develop metabolic engineering into a more systematic practice. PMID:25683235

  2. Protective Action of Anandamide and Its COX-2 Metabolite against l-Homocysteine-Induced NLRP3 Inflammasome Activation and Injury in Podocytes.

    PubMed

    Li, Guangbi; Xia, Min; Abais, Justine M; Boini, Krishna; Li, Pin-Lan; Ritter, Joseph K

    2016-07-01

    Recent studies have demonstrated that l-homocysteine (Hcys)-induced podocyte injury leading to glomerular damage or sclerosis is attributable to the activation of the nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome. Given the demonstrated anti-inflammatory effects of endocannabinoids, the present study was designed to test whether anandamide (AEA) or its metabolites diminish NLRP3 inflammasome activation and prevent podocyte injury and associated glomerular damage during hyperhomocysteinemia (hHcys). AEA (100 μM) inhibited Hcys-induced NLRP3 inflammasome activation in cultured podocytes, as indicated by elevated caspase-1 activity and interleukin-1β levels, and attenuated podocyte dysfunction, as shown by reduced vascular endothelial growth factor production. These effects of AEA were inhibited by the cyclooxygenase-2 (COX-2) inhibitor celecoxib (CEL). In mice in vivo, AEA treatment attenuated glomerular NLRP3 inflammasome activation induced by hHcys accompanying a folate-free diet, on the basis of inhibition of hHcys-induced colocalization of NLRP3 molecules and increased interleukin-1β levels in glomeruli. Correspondingly, AEA prevented hHcys-induced proteinuria, albuminuria, and glomerular damage observed microscopically. Hcys- and AEA-induced effects were absent in NLRP3-knockout mice. These beneficial effects of AEA against hHcys-induced NLRP3 inflammasome activation and glomerular injury were not observed in mice cotreated with CEL. We further demonstrated that prostaglandin E2-ethanolamide (PGE2-EA), a COX-2 product of AEA, at 10 μM had a similar inhibitory effect to that of 100 μM AEA on Hcys-induced NLRP3 inflammasome formation and activation in cultured podocytes. From these results, we conclude that AEA has anti-inflammatory properties, protecting podocytes from Hcys-induced injury by inhibition of NLRP3 inflammasome activation through its COX-2 metabolite, PGE2-EA. PMID:27189966

  3. Cell-specific activation and detoxification of benzene metabolites in mouse and human bone marrow: Identification of target cells and a potential role for modulation of apoptosis in benzene toxicity

    SciTech Connect

    Ross, D.; Siegel, D.; Schattenberg, D.G.

    1996-12-01

    The role of cell-specific metabolism in benzene toxicity was examined in both murine and human bone marrow. Hemopoietic progenitor cells and stromal cells are important control points for regulation of hemopoiesis. We show that the selective toxicity of hydroquinone at the level of the macrophage in murine bone marrow stroma may be explained by a high peroxidase/nicotanimicle adenine dinucleotide phosphate, reduced [NAD(P)H]:quinone oxidoreductase (NQO1) ratio. Peroxidases metabolize hydroquinone to the reactive 1,4-benzoquinone, whereas NQO1 reduces the quinones formed, resulting in detoxification. Peroxidase and NQO1 activity in human stromal cultures vary as a function of time in culture, with peroxidase activity decreasing and NQO1 activity increasing with time. Peroxidase activity and, more specifically, myeloperoxidase, which had previously been considered to be expressed at the promyelocyte level, was detected in murine lineage-negative and human CD34{sup +} progenitor cells. This provides a metabolic mechanism whereby phenolic metabolites of benzene can be bioactivated in progenitor cells, which are considered initial target cells for the development of leukemias. Consequences of a high peroxidase/NQO1 ratio in HL-60 cells were shown to include hydroquinone-induced apoptosis. Hydroquinone can also inhibit proteases known to play a role in induction of apoptosis, suggesting that it may be able to inhibit apoptosis induced by other stimuli. Modulation of apoptosis may lead to aberrant hemopoiesis and neoplastic progression. This enzyme-directed approach has identified target cells of the phenolic metabolites of benzene in bone marrow and provided a metabolic basis for benzene-induced toxicity at the level of the progenitor cell in both murine and human bone marrow. 60 refs., 8 figs.

  4. Fast Retrograde Signaling in Response to High Light Involves Metabolite Export, MITOGEN-ACTIVATED PROTEIN KINASE6, and AP2/ERF Transcription Factors in Arabidopsis[C][W

    PubMed Central

    Vogel, Marc Oliver; Moore, Marten; König, Katharina; Pecher, Pascal; Alsharafa, Khalid; Lee, Justin; Dietz, Karl-Josef

    2014-01-01

    Regulation of the expression of nuclear genes encoding chloroplast proteins allows for metabolic adjustment in response to changing environmental conditions. This regulation is linked to retrograde signals that transmit information on the metabolic state of the chloroplast to the nucleus. Transcripts of several APETALA2/ETHYLENE RESPONSE FACTOR transcription factors (AP2/ERF-TFs) were found to respond within 10 min after transfer of low-light-acclimated Arabidopsis thaliana plants to high light. Initiation of this transcriptional response was completed within 1 min after transfer to high light. The fast responses of four AP2/ERF genes, ERF6, RRTF1, ERF104, and ERF105, were entirely deregulated in triose phosphate/phosphate translocator (tpt) mutants. Similarly, activation of MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) was upregulated after 1 min in the wild type but not in the tpt mutant. Based on this, together with altered transcript regulation in mpk6 and erf6 mutants, a retrograde signal transmission model is proposed starting with metabolite export through the triose phosphate/phosphate translocator with subsequent MPK6 activation leading to initiation of AP2/ERF-TF gene expression and other downstream gene targets. The results show that operational retrograde signaling in response to high light involves a metabolite-linked pathway in addition to previously described redox and hormonal pathways. PMID:24668746

  5. Cyp2D6 catalyzes 5-hydroxylation of 1-(2-pyrimidinyl)-piperazine, an active metabolite of several psychoactive drugs, in human liver microsomes.

    PubMed

    Raghavan, Nirmala; Zhang, Donglu; Zhu, Mingshe; Zeng, Jianing; Christopher, Lisa

    2005-02-01

    1-(2-Pyrimidinyl)-piperazine (1-PP) is an active metabolite of several psychoactive drugs including buspirone. 1-PP is also the major metabolite in the human circulation and in rat brains following oral administration of buspirone. This study was conducted to identify the enzyme responsible for the metabolic conversion of 1-PP to 5-hydroxy-1-(2-pyrimidinyl)-piperazine (HO-1-PP) in human liver microsomes (HLMs). The product HO-1-PP was quantified by a validated liquid chromatography-tandem mass spectrometry method. In the presence of NADPH, 1-PP (100 microM) was incubated separately with human cDNA-expressed cytochrome P450 isozymes (including CYP2D6, 3A4, 1A2, 2A6, 2C9, 2C19, 2E1, and 2B6) at 37 degrees C. CYP2D6 catalyzed the formation of HO-1-PP from 1-PP. This catalytic activity was >95% inhibited by quinidine, a CYP2D6 inhibitor. HO-1-PP formation rates correlated well with the bufuralol 1-hydroxylase (CYP2D6) activities of individual HLMs. The formation of HO-1-PP followed a Michaelis-Menten kinetics with a K(m) of 171 microM and V(max) of 313 pmol/min x mg protein in HLMs. Collectively, these results indicate that polymorphic CYP2D6 is responsible for the conversion of 1-PP to HO-1-PP. PMID:15507542

  6. The distribution and clearance of (2S,6S)-hydroxynorketamine, an active ketamine metabolite, in Wistar rats

    PubMed Central

    Moaddel, Ruin; Sanghvi, Mitesh; Dossou, Katina Sourou Sylvestre; Ramamoorthy, Anuradha; Green, Carol; Bupp, James; Swezey, Robert; O’Loughlin, Kathleen; Wainer, Irving W

    2015-01-01

    The distribution, clearance, and bioavailability of (2S,6S)-hydroxynorketamine has been studied in the Wistar rat. The plasma and brain tissue concentrations over time of (2S,6S)-hydroxynorketamine were determined after intravenous (20 mg/kg) and oral (20 mg/kg) administration of (2S,6S)-hydroxynorketamine (n = 3). After intravenous administration, the pharmacokinetic parameters were estimated using noncompartmental analysis and the half-life of drug elimination during the terminal phase (t1/2) was 8.0 ± 4.0 h and the apparent volume of distribution (Vd) was 7352 ± 736 mL/kg, clearance (Cl) was 704 ± 139 mL/h per kg, and the bioavailability was 46.3%. Significant concentrations of (2S,6S)-hydroxynorketamine were measured in brain tissues at 10 min after intravenous administration, ∼30 μg/mL per g tissue which decreased to 6 μg/mL per g tissue at 60 min. The plasma and brain concentrations of (2S,6S)-hydroxynorketamine were also determined after the intravenous administration of (S)-ketamine, where significant plasma and brain tissue concentrations of (2S,6S)-hydroxynorketamine were observed 10 min after administration. The (S)-ketamine metabolites (S)-norketamine, (S)-dehydronorketamine, (2S,6R)-hydroxynorketamine, (2S,5S)-hydroxynorketamine and (2S,4S)-hydroxynorketamine were also detected in both plasma and brain tissue. The enantioselectivity of the conversion of (S)-ketamine and (R)-ketamine to the respective (2,6)-hydroxynorketamine metabolites was also investigated over the first 60 min after intravenous administration. (S)-Ketamine produced significantly greater plasma and brain tissue concentrations of (2S,6S)-hydroxynorketamine relative to the (2R,6R)-hydroxynorketamine observed after the administration of (R)-ketamine. However, the relative brain tissue: plasma concentrations of the enantiomeric (2,6)-hydroxynorketamine metabolites were not significantly different indicating that the penetration of the metabolite is not

  7. Escape Mutations in NS4B Render Dengue Virus Insensitive to the Antiviral Activity of the Paracetamol Metabolite AM404.

    PubMed

    van Cleef, Koen W R; Overheul, Gijs J; Thomassen, Michael C; Marjakangas, Jenni M; van Rij, Ronald P

    2016-04-01

    Despite the enormous disease burden associated with dengue virus infections, a licensed antiviral drug is lacking. Here, we show that the paracetamol (acetaminophen) metabolite AM404 inhibits dengue virus replication. Moreover, we find that mutations in NS4B that were previously found to confer resistance to the antiviral compounds NITD-618 and SDM25N also render dengue virus insensitive to AM404. Our work provides further support for NS4B as a direct or indirect target for antiviral drug development. PMID:26856827

  8. Mechanically driven activation of polyaniline into its conductive form.

    PubMed

    Baytekin, Bilge; Baytekin, H Tarik; Grzybowski, Bartosz A

    2014-07-01

    Mechanical treatment of polymers produces surface cations and anions which, as demonstrated here for the first time, can drive chemical reactions. In particular, it is shown that such a mechanical treatment transforms nonconductive polyaniline into its conductive form. These results provide a mechanical means of patterning conductive polymers and also coating small polymer objects with conductive polyaniline films preventing accumulation of static electricity. PMID:24824971

  9. A sensitive and rapid ultra HPLC-MS/MS method for the simultaneous detection of clopidogrel and its derivatized active thiol metabolite in human plasma.

    PubMed

    Peer, Cody J; Spencer, Shawn D; VanDenBerg, Dustin A H; Pacanowski, Michael A; Horenstein, Richard B; Figg, William D

    2012-01-01

    A sensitive, selective, and rapid ultra-high performance liquid chromatography-tandem mass spectrometry (uHPLC-MS/MS) was developed for the simultaneous quantification of clopidogrel (Plavix(®)) and its derivatized active metabolite (CAMD) in human plasma. Derivatization of the active metabolite in blood with 2-bromo-3'-methoxy acetophenone (MPB) immediately after collection ensured metabolite stability during sample handling and storage. Following addition of ticlopidine as an internal standard and simple protein precipitation, the analytes were separated on a Waters Acquity UPLC™ sub-2 μm-C(18) column via gradient elution before detection on a triple-quadrupole MS with multiple-reaction-monitoring via electrospray ionization. The method was validated across the clinically relevant concentration range of 0.01-50 ng/mL for parent clopidogrel and 0.1-150 ng/mL (r(2)=0.99) for CAMD, with a fast run time of 1.5 min to support pharmacokinetic studies using 75, 150, or 300 mg oral doses of clopidogrel. The analytical method measured concentrations of clopidogrel and CAMD with accuracy (%DEV) <±12% and precision (%CV) of <±6%. The method was successfully applied to measure the plasma concentrations of clopidogrel and CAMD in three subjects administered single oral doses of 75, 150, and 300 mg clopidogrel. It was further demonstrated that the derivatizing agent (MPB) does not affect clopidogrel levels, thus from one aliquot of blood drawn clinically, this method can simultaneously quantify both clopidogrel and CAMD with sensitivity in the picogram per mL range. PMID:22169056

  10. The toxicity of the N-hydroxy and 6-hydroxy metabolites of 3,4-dichloropropionanilide does not depend on calcium release-activated calcium channel inhibition.

    PubMed

    Lewis, Tricia L; Holásková, Ida; Barnett, John B

    2013-02-01

    Each year ~1 billion kg of herbicides are used worldwide to control the unwanted growth of plants. In the United States, over a quarter of a billion kg of herbicides are used, representing 28% of worldwide use. (Kiely, T., Donaldson, D., and Grube, A. [2004]. Pesticide Industry Sales and Usage. 2000 and 2001 Market Estimates. Available at: http://www.epa.gov/pesticides/pestsales/01pestsales/market_estimates2001.pdf. Accessed October 25, 2012.) Propanil (3,4-dichloropropionanilide [DCPA]) is a commonly used herbicide in the United States, with 2-4 million kg applied annually to 2 million acres of crop land. The immunomodulatory effects of DCPA have been well documented, but limited data are available on the effects of its metabolites. (Salazar, K. D., Ustyugova, I. V., Brundage, K. M., Barnett, J. B., and Schafer, R. [2008]. A review of the immunotoxicity of the pesticide 3,4-dichloropropionanalide. J. Toxicol. Environ. Health B Crit. Rev. 11, 630-645.) In mammals, hepatic enzymes metabolize DCPA, resulting in the production of 3,4-dichloroaniline (DCA). Further biotransformation of DCA leads to the production of 6-hydroxy-3,4-dichloroaniline (6OH-DCA) and N-hydroxy-3,4-dichloroaniline (NOH-DCA). We report, for the first time, the immunotoxic effects of DCPA metabolites on T-cell function. Human Jurkat T cells were exposed to varying concentrations of DCPA or its metabolites and assayed for effects on T-cell function. In addition, fluorine analogs of DCPA and DCA were investigated to determine the relative role of chlorine substituents on T-cell immunotoxicity. Here we report that exposure of Jurkat T cells to DCPA and DCA alters IL-2 secretion, nuclear factor of activated T cells (NFAT) activity, and calcium influx. However, exposure to 6OH-DCA and NOH-DCA reduces IL-2 secretion and NFAT activity but has no effect on calcium flux. When both chlorines in DCPA and DCA were substituted with fluorines all effects were abrogated. Our data indicate that metabolites of

  11. The Toxicity of the N-Hydroxy and 6-Hydroxy Metabolites of 3,4-Dichloropropionanilide Does Not Depend on Calcium Release–Activated Calcium Channel Inhibition

    PubMed Central

    Barnett, John B.

    2013-01-01

    Each year ~1 billion kg of herbicides are used worldwide to control the unwanted growth of plants. In the United States, over a quarter of a billion kg of herbicides are used, representing 28% of worldwide use. (Kiely, T., Donaldson, D., and Grube, A. [2004]. Pesticide Industry Sales and Usage. 2000 and 2001 Market Estimates. Available at: http://www.epa.gov/pesticides/pestsales/01pestsales/market_estimates2001.pdf. Accessed October 25, 2012.) Propanil (3,4-dichloropropionanilide [DCPA]) is a commonly used herbicide in the United States, with 2–4 million kg applied annually to 2 million acres of crop land. The immunomodulatory effects of DCPA have been well documented, but limited data are available on the effects of its metabolites. (Salazar, K. D., Ustyugova, I. V., Brundage, K. M., Barnett, J. B., and Schafer, R. [2008]. A review of the immunotoxicity of the pesticide 3,4-dichloropropionanalide. J. Toxicol. Environ. Health B Crit. Rev. 11, 630–645.) In mammals, hepatic enzymes metabolize DCPA, resulting in the production of 3,4-dichloroaniline (DCA). Further biotransformation of DCA leads to the production of 6-hydroxy-3,4-dichloroaniline (6OH-DCA) and N-hydroxy-3,4-dichloroaniline (NOH-DCA). We report, for the first time, the immunotoxic effects of DCPA metabolites on T-cell function. Human Jurkat T cells were exposed to varying concentrations of DCPA or its metabolites and assayed for effects on T-cell function. In addition, fluorine analogs of DCPA and DCA were investigated to determine the relative role of chlorine substituents on T-cell immunotoxicity. Here we report that exposure of Jurkat T cells to DCPA and DCA alters IL-2 secretion, nuclear factor of activated T cells (NFAT) activity, and calcium influx. However, exposure to 6OH-DCA and NOH-DCA reduces IL-2 secretion and NFAT activity but has no effect on calcium flux. When both chlorines in DCPA and DCA were substituted with fluorines all effects were abrogated. Our data indicate that metabolites

  12. Sex-, Species-, and Tissue-Specific Metabolism of Empagliflozin in Male Mouse Kidney Forms an Unstable Hemiacetal Metabolite (M466/2) That Degrades to 4-Hydroxycrotonaldehyde, a Reactive and Cytotoxic Species.

    PubMed

    Taub, Mitchell E; Ludwig-Schwellinger, Eva; Ishiguro, Naoki; Kishimoto, Wataru; Yu, Hongbin; Wagner, Klaus; Tweedie, Donald

    2015-01-20

    Following oral administration of empagliflozin (1000 mg/kg/day) to male and female CD-1 mice for 2 years, renal tubular injury was identified in male mice. Renal injury was not detected in male mice (≤300 mg/kg/day), in female mice (1000 mg/kg/day), or in male or female Han Wistar rats (700 mg/kg/day). Using transfected HEK293 cells and Xenopus oocytes, empagliflozin was found to be a substrate of various mouse and rat organic anion transporters (oat/Oat) and organic anion transporting polypeptide (oatp/Oatp) transporters: mouse oat3, rat Oat3, mouse oatp1a1, and rat Oatp1a1. However, using isolated kidney slices from male and female mice and rats, no sex-based difference in the extent of uptake of empagliflozin occurred. Metabolism studies using hepatic and renal microsomes from male and female mice, rats, and humans revealed a hemiacetal metabolite of empagliflozin (M466/2), predominantly formed in male mouse kidney microsomes. Formation of M466/2 in male mouse kidney microsomes was 31-fold higher compared to that in female mouse kidney microsomes and was ∼29- and ∼20-fold higher compared to that in male and female mouse liver microsomes, respectively. M466/2 is unstable and degrades to form a phenol metabolite (M380/1) and 4-hydroxycrotonaldehyde (4-OH CTA). Formed 4-OH CTA was trapped by reduced GSH, and the structure of the GSH adduct was confirmed by mass spectrometry. Stoichiometric formation of M380/1 from M466/2 was observed (93-96% at 24 h); however, formation of 4-OH CTA was considerably lower (∼17.5% at 40 h), which is consistent with 4-OH CTA being a highly reactive species. These data represent a highly selective tissue-, species-, and sex-specific lesion in male CD-1 mice associated with a cytotoxic metabolite product, 4-OH CTA. In humans, glucuronidation of empagliflozin is the most prevalent metabolic pathway, and oxidation is a minor pathway. Thus, renal toxicity due to the formation of 4-OH CTA from empagliflozin is not expected in humans

  13. The Androgen Metabolite, 5α-Androstane-3β,17β-Diol (3β-Diol), Activates the Oxytocin Promoter Through an Estrogen Receptor-β Pathway

    PubMed Central

    Hiroi, Ryoko; Lacagnina, Anthony F.; Hinds, Laura R.; Carbone, David G.; Uht, Rosalie M.

    2013-01-01

    Testosterone has been shown to suppress the acute stress-induced activation of the hypothalamic-pituitary-adrenal axis; however, the mechanisms underlying this response remain unclear. The hypothalamic-pituitary-adrenal axis is regulated by a neuroendocrine subpopulation of medial parvocellular neurons in the paraventricular nucleus of the hypothalamus (PVN). These neurons are devoid of androgen receptors (ARs). Therefore, a possibility is that the PVN target neurons respond to a metabolite in the testosterone catabolic pathway via an AR-independent mechanism. The dihydrotestosterone metabolite, 5α-androstane-3β,17β-diol (3β-diol), binds and activates estrogen receptor-β (ER-β), the predominant ER in the PVN. In the PVN, ER-β is coexpressed with oxytocin (OT). Therefore, we tested the hypothesis that 3β-diol regulates OT expression through ER-β activation. Treatment of ovariectomized rats with estradiol benzoate or 3β-diol for 4 days increased OT mRNA selectively in the midcaudal, but not rostral PVN compared with vehicle-treated controls. 3β-Diol treatment also increased OT mRNA in the hypothalamic N38 cell line in vitro. The functional interactions between 3β-diol and ER-β with the human OT promoter were examined using an OT promoter-luciferase reporter construct (OT-luc). In a dose-dependent manner, 3β-diol treatment increased OT-luc activity when cells were cotransfected with ER-β, but not ER-α. The 3β-diol–induced OT-luc activity was reduced by deletion of the promoter region containing the composite hormone response element (cHRE). Point mutations of the cHRE also prevented OT-luc activation by 3β-diol. These results indicate that 3β-diol induces OT promoter activity via ER-β–cHRE interactions. PMID:23515287

  14. Thrombomodulin Binding Selects the Catalytically Active Form of Thrombin.

    PubMed

    Handley, Lindsey D; Treuheit, Nicholas A; Venkatesh, Varun J; Komives, Elizabeth A

    2015-11-01

    Human α-thrombin is a serine protease with dual functions. Thrombin acts as a procoagulant, cleaving fibrinogen to make the fibrin clot, but when bound to thrombomodulin (TM), it acts as an anticoagulant, cleaving protein C. A minimal TM fragment consisting of the fourth, fifth, and most of the sixth EGF-like domain (TM456m) that has been prepared has much improved solubility, thrombin binding capacity, and anticoagulant activity versus those of previous TM456 constructs. In this work, we compare backbone amide exchange of human α-thrombin in three states: apo, D-Phe-Pro-Arg-chloromethylketone (PPACK)-bound, and TM456m-bound. Beyond causing a decreased level of amide exchange at their binding sites, TM and PPACK both cause a decreased level of amide exchange in other regions including the γ-loop and the adjacent N-terminus of the heavy chain. The decreased level of amide exchange in the N-terminus of the heavy chain is consistent with the historic model of activation of serine proteases, which involves insertion of this region into the β-barrel promoting the correct conformation of the catalytic residues. Contrary to crystal structures of thrombin, hydrogen-deuterium exchange mass spectrometry results suggest that the conformation of apo-thrombin does not yet have the N-terminus of the heavy chain properly inserted for optimal catalytic activity, and that binding of TM allosterically promotes the catalytically active conformation. PMID:26468766

  15. Forming a Learning Culture to Promote Fracture Prevention Activities

    ERIC Educational Resources Information Center

    Hjalmarson, Helene V.; Strandmark, Margaretha

    2012-01-01

    Purpose: The purpose of this paper is to explore interprofessional experiences of incorporating fracture prevention activities in clinical practice inspired by an empowerment approach. Design/methodology/approach: Data collection consisted primarily of focus groups interviews, systematized and analyzed by the grounded theory method. The study took…

  16. Changes in the contents of metabolites and enzyme activities in rice plants responding to Rhizoctonia solani Kuhn infection: activation of glycolysis and connection to phenylpropanoid pathway.

    PubMed

    Mutuku, J Musembi; Nose, Akihiro

    2012-06-01

    Rhizoctonia solani Kuhn causes sheath blight disease in rice, and genetic resistance against it is the most desirable characteristic. Current improvement efforts are based on analysis of polygenic quantitative trait loci (QTLs), but interpretation is limited by the lack of information on the changes in metabolic pathways. Our previous studies linked activation of the glycolytic pathway to enhanced generation of lignin in the phenylpropanoid pathway. The current studies investigated the regulation of glycolysis by examining the time course of changes in enzymatic activities and metabolite contents. The results showed that the activities of all glycolytic enzymes as well as fructose-6-phosphate (F-6-P), fructose-1,6-bisphosphate (F-1,6-P(2)), dihydroxyacetone phosphate (DHAP), glyceraldehyde-3-phosphate (GAP), 3-phosphoglycerate (3-PG), phosphoenolpyruvate (PEP) and pyruvate contents increased. These results combined with our previous findings that the expression of phosphoglucomutase (PGM), triosephosphate isomerase (TPI), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), enolase and pyruvate kinase (PK) increased after infection suggested that the additional establishment of glycolysis in the cytosol compartment occurred after infection. Further evidence for this was our recent findings that the increase in expression of the 6-phosphofructokinase (PFK) plastid isozyme Os06g05860 was accompanied by an increase in expression of three cytosolic PFK isozymes, i.e. Os01g09570, Os01g53680 and Os04g39420, as well as pyrophosphate-dependent phosphofrucokinase (PFP) isozymes Os08g25720 (α-subunit) and Os06g13810 (β-subunit) in infected rice plants of the resistant line. The results also showed that the reactions catalysed by PFK/PFP, aldolase, GAPDH + phosphoglycerate kinase (PGK) and PK in leaf sheaths of R. solani-infected rice plants were non-equilibrium reactions in vivo. This study showed that PGM, phosphoglucose isomerase (PGI), TPI and phosphoglycerate mutase (PGmu

  17. Simultaneous Determination and Pharmacokinetic Study of Protocatechuic Aldehyde and Its Major Active Metabolite Protocatechuic Acid in Rat Plasma by Liquid Chromatography-Tandem Mass Spectrometry.

    PubMed

    Wang, Xiangyang; Yan, Kaijing; Ma, Xiaohui; Li, Wei; Chu, Yang; Guo, Jiahua; Li, Shuming; Zhou, Shuiping; Zhu, Yonghong; Liu, Changxiao

    2016-05-01

    A very simple and selective high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS-MS) method was developed for simultaneous determination and pharmacokinetic study of protocatechuic aldehyde (PAL) and its active metabolite protocatechuic acid (PCA). The method involves a simple liquid-liquid extraction with ethyl acetate. The separation was performed on a Hypersil GOLD C18column (2.1 × 150 mm, 3.0 µm; particle, Thermo, USA) with isocratic elution using a mobile phase consisted of methanol and water (containing 0.1% formic acid) at a flow rate of 0.2 mL/min. The detection of target compounds was done by using low-energy collision dissociation tandem mass spectrometry (CID-MS-MS) using the selective reaction monitoring scan mode. The method was linear for all analytes over the investigated range for all correlation coefficients greater than 0.9950. The lower limits of quantification were 2.0 ng/mL for PAL and PCA. The intra- and interday precisions (relative standard deviation, RSD %) were <6.84 and 5.54%, and the accuracy (relative error, RE %) was between -2.85 and 0.74% (n= 6). The developed method was applied to study the pharmacokinetics of PAL and its major active metabolite PCA in rat plasma after oral and intravenous administration of PAL. PMID:26969682

  18. Novel, unifying mechanism for mescaline in the central nervous system: electrochemistry, catechol redox metabolite, receptor, cell signaling and structure activity relationships.

    PubMed

    Kovacic, Peter; Somanathan, Ratnasamy

    2009-01-01

    A unifying mechanism for abused drugs has been proposed previously from the standpoint of electron transfer. Mescaline can be accommodated within the theoretical framework based on redox cycling by the catechol metabolite with its quinone counterpart. Electron transfer may play a role in electrical effects involving the nervous system in the brain. This approach is in accord with structure activity relationships involving mescaline, abused drugs, catecholamines, and etoposide. Inefficient demethylation is in keeping with the various drug properties, such as requirement for high dosage and slow acting. There is a discussion of receptor binding, electrical effects, cell signaling and other modes of action. Mescaline is a nonselective, seretonin receptor agonist. 5-HTP receptors are involved in the stimulus properties. Research addresses the aspect of stereochemical requirements. Receptor binding may involve the proposed quinone metabolite and/or the amino sidechain via protonation. Electroencephalographic studies were performed on the effects of mescaline on men. Spikes are elicited by stimulation of a cortical area. The potentials likely originate in nonsynaptic dendritic membranes. Receptor-mediated signaling pathways were examined which affect mescaline behavior. The hallucinogen belongs to the class of 2AR agonists which regulate pathways in cortical neurons. The research identifies neural and signaling mechanisms responsible for the biological effects. Recently, another hallucinogen, psilocybin, has been included within the unifying mechanistic framework. This mushroom constituent is hydrolyzed to the phenol psilocin, also active, which is subsequently oxidized to an ET o-quinone or iminoquinone. PMID:20716904

  19. Type I interferons and microbial metabolites of tryptophan modulate astrocyte activity and central nervous system inflammation via the aryl hydrocarbon receptor.

    PubMed

    Rothhammer, Veit; Mascanfroni, Ivan D; Bunse, Lukas; Takenaka, Maisa C; Kenison, Jessica E; Mayo, Lior; Chao, Chun-Cheih; Patel, Bonny; Yan, Raymond; Blain, Manon; Alvarez, Jorge I; Kébir, Hania; Anandasabapathy, Niroshana; Izquierdo, Guillermo; Jung, Steffen; Obholzer, Nikolaus; Pochet, Nathalie; Clish, Clary B; Prinz, Marco; Prat, Alexandre; Antel, Jack; Quintana, Francisco J

    2016-06-01

    Astrocytes have important roles in the central nervous system (CNS) during health and disease. Through genome-wide analyses we detected a transcriptional response to type I interferons (IFN-Is) in astrocytes during experimental CNS autoimmunity and also in CNS lesions from patients with multiple sclerosis (MS). IFN-I signaling in astrocytes reduces inflammation and experimental autoimmune encephalomyelitis (EAE) disease scores via the ligand-activated transcription factor aryl hydrocarbon receptor (AHR) and the suppressor of cytokine signaling 2 (SOCS2). The anti-inflammatory effects of nasally administered interferon (IFN)-β are partly mediated by AHR. Dietary tryptophan is metabolized by the gut microbiota into AHR agonists that have an effect on astrocytes to limit CNS inflammation. EAE scores were increased following ampicillin treatment during the recovery phase, and CNS inflammation was reduced in antibiotic-treated mice by supplementation with the tryptophan metabolites indole, indoxyl-3-sulfate, indole-3-propionic acid and indole-3-aldehyde, or the bacterial enzyme tryptophanase. In individuals with MS, the circulating levels of AHR agonists were decreased. These findings suggest that IFN-Is produced in the CNS function in combination with metabolites derived from dietary tryptophan by the gut flora to activate AHR signaling in astrocytes and suppress CNS inflammation. PMID:27158906

  20. Anti-Adhesive Activity of Cranberry Phenolic Compounds and Their Microbial-Derived Metabolites against Uropathogenic Escherichia coli in Bladder Epithelial Cell Cultures

    PubMed Central

    de Llano, Dolores González; Esteban-Fernández, Adelaida; Sánchez-Patán, Fernando; Martín-Álvarez, Pedro J.; Moreno-Arribas, Mª Victoria; Bartolomé, Begoña

    2015-01-01

    Cranberry consumption has shown prophylactic effects against urinary tract infections (UTI), although the mechanisms involved are not completely understood. In this paper, cranberry phenolic compounds and their potential microbial-derived metabolites (such as simple phenols and benzoic, phenylacetic and phenylpropionic acids) were tested for their capacity to inhibit the adherence of uropathogenic Escherichia coli (UPEC) ATCC®53503™ to T24 epithelial bladder cells. Catechol, benzoic acid, vanillic acid, phenylacetic acid and 3,4-dihydroxyphenylacetic acid showed anti-adhesive activity against UPEC in a concentration-dependent manner from 100–500 µM, whereas procyanidin A2, widely reported as an inhibitor of UPEC adherence on uroepithelium, was only statistically significant (p < 0.05) at 500 µM (51.3% inhibition). The results proved for the first time the anti-adhesive activity of some cranberry-derived phenolic metabolites against UPEC in vitro, suggesting that their presence in the urine could reduce bacterial colonization and progression of UTI. PMID:26023719

  1. Evaluating the Effects of Tetrachloro-1,4-benzoquinone, an Active Metabolite of Pentachlorophenol, on the Growth of Human Breast Cancer Cells

    PubMed Central

    Ling, Binbing; Gao, Bosong; Yang, Jian

    2016-01-01

    Tetrachloro-1,4-benzoquinone (TCBQ), an active metabolite of pentachlorophenol (PCP), is genotoxic and potentially carcinogenic. As an electrophilic and oxidative molecule, TCBQ can conjugate with deoxyguanosine in DNA molecules and/or impose oxidative stress in cells. In the current study, we investigated the effects of TCBQ on intracellular ROS production, apoptosis, and cytotoxicity against three different subtypes of human breast cancer cells. Luminal A subtype MCF7 (ER+, PR+, HER2−) cells maintained the highest intracellular ROS level and were subjected to TCBQ-induced ROS reduction, apoptosis, and cytotoxicity. HER2 subtype Sk-Br-3 (ER−, PR−, HER2+) cells possessed the lowest intracellular ROS level. TCBQ promoted ROS production, inhibited apoptosis, and elevated cytotoxicity (due to necrosis) against Sk-Br-3 cells. Triple-negative/basal-like subtype MDA-MB-231 cells were less sensitive towards TCBQ treatment. Therefore, the effect of prolonged exposure to PCP and its active metabolites on cancer growth is highly cancer-cell-type specific. PMID:26981120

  2. Anti-Adhesive Activity of Cranberry Phenolic Compounds and Their Microbial-Derived Metabolites against Uropathogenic Escherichia coli in Bladder Epithelial Cell Cultures.

    PubMed

    de Llano, Dolores González; Esteban-Fernández, Adelaida; Sánchez-Patán, Fernando; Martínlvarez, Pedro J; Moreno-Arribas, Maria Victoria; Bartolomé, Begoña

    2015-01-01

    Cranberry consumption has shown prophylactic effects against urinary tract infections (UTI), although the mechanisms involved are not completely understood. In this paper, cranberry phenolic compounds and their potential microbial-derived metabolites (such as simple phenols and benzoic, phenylacetic and phenylpropionic acids) were tested for their capacity to inhibit the adherence of uropathogenic Escherichia coli (UPEC) ATCC®53503™ to T24 epithelial bladder cells. Catechol, benzoic acid, vanillic acid, phenylacetic acid and 3,4-dihydroxyphenylacetic acid showed anti-adhesive activity against UPEC in a concentration-dependent manner from 100-500 µM, whereas procyanidin A2, widely reported as an inhibitor of UPEC adherence on uroepithelium, was only statistically significant (p < 0.05) at 500 µM (51.3% inhibition). The results proved for the first time the anti-adhesive activity of some cranberry-derived phenolic metabolites against UPEC in vitro, suggesting that their presence in the urine could reduce bacterial colonization and progression of UTI. PMID:26023719

  3. Quantitation of sorafenib and its active metabolite sorafenib N-oxide in human plasma by liquid chromatography-tandem mass spectrometry.

    PubMed

    Li, Lie; Zhao, Ming; Navid, Fariba; Pratz, Keith; Smith, B Doug; Rudek, Michelle A; Baker, Sharyn D

    2010-11-01

    A simple and rapid method with high performance liquid chromatography/tandem mass spectrometry is described for the quantitation of the kinase inhibitor sorafenib and its active metabolite sorafenib N-oxide in human plasma. A protein precipitation extraction procedure was applied to 50 μL of plasma. Chromatographic separation of the two analytes, and the internal standard [(2)H(3)(13)C]-sorafenib, was achieved on a C(18) analytical column and isocratic flow at 0.3 mL/min for 4 min. Mean within-run and between-run precision for all analytes were <6.9% and accuracy was <5.3%. Calibration curves were linear over the concentration range of 50-10,000 ng/mL for sorafenib and 10-2500 ng/mL for sorafenib N-oxide. This method allows a specific, sensitive, and reliable determination of the kinase inhibitor sorafenib and its active metabolite sorafenib N-oxide in human plasma in a single analytical run. PMID:20870468

  4. How Lipid Membranes Affect Pore Forming Toxin Activity.

    PubMed

    Rojko, Nejc; Anderluh, Gregor

    2015-12-15

    Pore forming toxins (PFTs) evolved to permeate the plasma membrane of target cells. This is achieved in a multistep mechanism that usually involves binding of soluble protein monomer to the lipid membrane, oligomerization at the plane of the membrane, and insertion of part of the polypeptide chain across the lipid membrane to form a conductive channel. Introduced pores allow uncontrolled transport of solutes across the membrane, inflicting damage to the target cell. PFTs are usually studied from the perspective of structure-function relationships, often neglecting the important role of the bulk membrane properties on the PFT mechanism of action. In this Account, we discuss how membrane lateral heterogeneity, thickness, and fluidity influence the pore forming process of PFTs. In general, lipid molecules are more accessible for binding in fluid membranes due to steric reasons. When PFT specifically binds ordered domains, it usually recognizes a specific lipid distribution pattern, like sphingomyelin (SM) clusters or SM/cholesterol complexes, and not individual lipid species. Lipid domains were also suggested to act as an additional concentration platform facilitating PFT oligomerization, but this is yet to be shown. The last stage in PFT action is the insertion of the transmembrane segment across the membranes to build the transmembrane pore walls. Conformational changes are a spontaneous process, and sufficient free energy has to be available for efficient membrane penetration. Therefore, fluid bilayers are permeabilized more readily in comparison to highly ordered and thicker liquid ordered lipid phase (Lo). Energetically more costly insertion into the Lo phase can be driven by the hydrophobic mismatch between the thinner liquid disordered phase (Ld) and large protein complexes, which are unable to tilt like single transmembrane segments. In the case of proteolipid pores, membrane properties can directly modulate pore size, stability, and even selectivity. Finally

  5. The fungal metabolite gliotoxin inhibits proteasome proteolytic activity and induces an irreversible pseudocystic transformation and cell death in Tritrichomonas foetus.

    PubMed

    Pereira-Neves, Antonio; Menna-Barreto, Rubem F S; Benchimol, Marlene

    2016-08-01

    Proteasomal proteolysis is required for a wide range of cellular processes, including protein quality control, cell cycle progression, cell death and metabolic adaptation to environment changes or stress responses. Proteasome inhibitors are useful compounds for determining the roles of proteasome in eukaryotic cells. Here, we investigated the effects of gliotoxin, a proteasome inhibitor, on the cell growth, replication, ultrastructure, DNA integrity and proteasomal proteolytic activity of the protist parasite Tritrichomonas foetus. The effect of gliotoxin on the transformation of T. foetus to endoflagellar form (EFF), also known as pseudocyst, was investigated. Gliotoxin inhibited the culture growth, arrested cell cycle, and provoked a trichomonacidal effect in a dose-dependent manner. Parasites treated with gliotoxin displayed features typical of cell death, such as membrane blebbing, concentric membrane whorls containing remnants of organelles, intense cytosolic and nuclear vacuolisation, chromatin condensation, DNA fragmentation, cytoplasmic disintegration and plasma membrane disruption. The proteasomal peptidase activity was inhibited by gliotoxin in a dose-dependent manner. Gliotoxin treatment also induced an irreversible EFF transformation in a dose/time-dependent manner. We compared morphological characteristics between gliotoxin- and cold-induced EFF parasites. Our results suggest that gliotoxin could induce EFF transformation by a mechanism distinct from that provoked by cold temperature. This study further contributes to a better understanding of the role of proteasome system in cell cycle, cell death and EFF transformation in T. foetus. PMID:27106236

  6. Active Curved Polymers Form Vortex Patterns on Membranes

    NASA Astrophysics Data System (ADS)

    Denk, Jonas; Huber, Lorenz; Reithmann, Emanuel; Frey, Erwin

    2016-04-01

    Recent in vitro experiments with FtsZ polymers show self-organization into different dynamic patterns, including structures reminiscent of the bacterial Z ring. We model FtsZ polymers as active particles moving along chiral, circular paths by Brownian dynamics simulations and a Boltzmann approach. Our two conceptually different methods point to a generic phase behavior. At intermediate particle densities, we find self-organization into vortex structures including closed rings. Moreover, we show that the dynamics at the onset of pattern formation is described by a generalized complex Ginzburg-Landau equation.

  7. Active Curved Polymers Form Vortex Patterns on Membranes.

    PubMed

    Denk, Jonas; Huber, Lorenz; Reithmann, Emanuel; Frey, Erwin

    2016-04-29

    Recent in vitro experiments with FtsZ polymers show self-organization into different dynamic patterns, including structures reminiscent of the bacterial Z ring. We model FtsZ polymers as active particles moving along chiral, circular paths by Brownian dynamics simulations and a Boltzmann approach. Our two conceptually different methods point to a generic phase behavior. At intermediate particle densities, we find self-organization into vortex structures including closed rings. Moreover, we show that the dynamics at the onset of pattern formation is described by a generalized complex Ginzburg-Landau equation. PMID:27176542

  8. 75 FR 21013 - Agency Information Collection Activities: Form N-644; Extension of an Existing Information...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form N-644... Collection Under Review; Form N- 644, Application for Posthumous Citizenship; OMB Control No. 1615-0059. The..., USCIS will be evaluating whether to revise the Form N-644. Should USCIS decide to revise Form N-644...

  9. 76 FR 21913 - Agency Information Collection Activities: Form N-644; Extension of an Existing Information...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-19

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form N-644... Collection Under Review: Form N- 644, Application for Posthumous Citizenship; OMB Control No. 1615-0059. The..., USCIS will be evaluating whether to revise the Form N-644. Should USCIS decide to revise Form N-644...

  10. 75 FR 51095 - Agency Information Collection Activities: Form N-336; Extension of an Existing Information...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form N-336... Collection under Review; Form N- 336, Request for Hearing on a Decision in Naturalization Proceedings Under... the Form N-336. Should USCIS decide to revise Form N-336 we will advise the public when we publish...

  11. Heat of Hydration of Low Activity Cementitious Waste Forms

    SciTech Connect

    Nasol, D.

    2015-07-23

    During the curing of secondary waste grout, the hydraulic materials in the dry mix react exothermally with the water in the secondary low-activity waste (LAW). The heat released, called the heat of hydration, can be measured using a TAM Air Isothermal Calorimeter. By holding temperature constant in the instrument, the heat of hydration during the curing process can be determined. This will provide information that can be used in the design of a waste solidification facility. At the Savannah River National Laboratory (SRNL), the heat of hydration and other physical properties are being collected on grout prepared using three simulants of liquid secondary waste generated at the Hanford Site. From this study it was found that both the simulant and dry mix each had an effect on the heat of hydration. It was also concluded that the higher the cement content in the dry materials mix, the greater the heat of hydration during the curing of grout.

  12. The Active Tamoxifen Metabolite Endoxifen (4OHNDtam) Strongly Down-Regulates Cytokeratin 6 (CK6) in MCF-7 Breast Cancer Cells

    PubMed Central

    Dankel, Simon; Fenne, Ingvild S.; Skartveit, Linn; Drangevåg, Andreas; Bozickovic, Olivera; Flågeng, Marianne Hauglid; Søiland, Håvard; Mellgren, Gunnar; Lien, Ernst A.

    2015-01-01

    Introduction Tamoxifen is an anti-estrogen drug used in treatment of Estrogen Receptor (ER) positive breast cancer. Effects and side effects of tamoxifen is the sum of tamoxifen and all its metabolites. 4-Hydroxytamoxifen (4OHtam) and 4-hydroxy-N-demethyltamoxifen (4OHNDtam, endoxifen) both have ER affinity exceeding that of the parent drug tamoxifen. 4OHNDtam is considered the main active metabolite of tamoxifen. Ndesmethyltamoxifen (NDtam) is the major tamoxifen metabolite. It has low affinity to the ER and is not believed to influence tumor growth. However, NDtam might mediate adverse effects of tamoxifen treatment. In this study we investigated the gene regulatory effects of the three metabolites of tamoxifen in MCF-7 breast cancer cells. Material and Methods Using concentrations that mimic the clinical situation we examined effects of 4OHtam, 4OHNDtam and NDtam on global gene expression in 17β-estradiol (E2) treated MCF-7 cells. Transcriptomic responses were assessed by correspondence analysis, differential expression, gene ontology analysis and quantitative real time PCR (Q-rt-PCR). E2 deprivation and knockdown of Steroid Receptor Coactivator-3 (SRC-3)/Amplified in Breast Cancer 1 (AIB1) mRNA in MCF-7 cells were performed to further characterize specific effects on gene expression. Results 4OHNDtam and 4OHtam caused major changes in gene expression compared to treatment with E2 alone, with a stronger effect of 4OHNDtam. NDtam had nearly no effect on the global gene expression profile. Treatment of MCF-7 cells with 4OHNDtam led to a strong down-regulation of the CytoKeratin 6 isoforms (KRT6A, KRT6B and KRT6C). The CytoKeratin 6 mRNAs were also down-regulated in MCF-7 cells after E2 deprivation and after SRC-3/AIB1 knockdown. Conclusion Using concentrations that mimic the clinical situation we report global gene expression changes that were most pronounced with 4OHNDtam and minimal with NDtam. Genes encoding CytoKeratin 6, were highly down-regulated by 4

  13. Deoxyguanosine Forms a Bis-adduct with E,E-Muconaldehyde, an Oxidative Metabolite of Benzene. Implications for the Carcinogenicity of Benzene

    PubMed Central

    Harris, Constance M.; Stec, Donald F.; Christov, Plamen P.; Kozekov, Ivan D.; Rizzo, Carmelo J.; Harris, Thomas M.

    2011-01-01

    Benzene is employed in large quantities in the chemical industry and is a ubiquitous contaminant in the environment. There is strong epidemiological evidence that benzene exposure induces hematopoietic malignancies, especially acute myeloid leukemia, in humans but the chemical mechanisms remain obscure. E,E-Muconaldehyde is one of the products of metabolic oxidation of benzene. This paper explores the proposition that E,E-muconaldehyde is capable of forming Gua-Gua cross-links. If formed in DNA, the replication and repair of such cross-links might introduce structural defects that could be the origin of the carcinogenicity. We have investigated the reaction of E,E-muconaldehyde with dGuo and found the reaction yields two pairs of interconverting diastereomers of a novel heptacyclic bis-adduct having a spiro ring system linking the two Gua residues. The structures of the four diastereomers have been established by NMR spectroscopy and their absolute configurations by comparison of CD spectra with those of model compounds having known configurations. The final two steps in formation of the bis-nucleoside (5-ring → 6-ring → 7-ring) have significant reversibility, which is the basis for the observed epimerization. The 6-ring precursor was trapped from the equilibrating mixture by reduction with NaBH4. The anti relationship of the two Gua residues in the heptacyclic bis-adduct precludes it from being formed in B DNA but the 6-ring precursor could readily be accommodated as an interchain or intrachain cross-link. It should be possible to form similar cross-links of dCyt, dAdo, the ε-amino group of lysine, and N-termini of peptides with the dGuo-muconaldehyde monoadduct. PMID:21972945

  14. Identification of biotransformation products of citalopram formed in activated sludge.

    PubMed

    Beretsou, Vasiliki G; Psoma, Aikaterini K; Gago-Ferrero, Pablo; Aalizadeh, Reza; Fenner, Kathrin; Thomaidis, Nikolaos S

    2016-10-15

    Citalopram (CTR) is a worldwide highly consumed antidepressant which has demonstrated incomplete removal by conventional wastewater treatment. Despite its global ubiquitous presence in different environmental compartments, little is known about its behaviour and transformation processes during wastewater treatment. The present study aims to expand the knowledge on fate and transformation of CTR during the biological treatment process. For this purpose, batch reactors were set up to assess biotic, abiotic and sorption losses of this compound. One of the main objectives of the study was the identification of the formed transformation products (TPs) by applying suspect and non-target strategies based on liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). The complementary use of reversed phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC) for the identification of polar TPs, and the application of in-house developed quantitative structure-retention relationship (QSRR) prediction models, in addition to the comprehensive evaluation of the obtained MS/MS spectra, provided valuable information to support identification. In total, fourteen TPs were detected and thirteen of them were tentatively identified. Four compounds were confirmed (N-desmethylCTR, CTR amide, CTR carboxylic acid and 3-oxo-CTR) through the purchase of the corresponding reference standard. Probable structures based on diagnostic evidence were proposed for the additional nine TPs. Eleven TPs are reported for the first time. A transformation pathway for the biotransformation of CTR was proposed. The presence of the identified TPs was assessed in real wastewater samples through retrospective analysis, resulting in the detection of five compounds. Finally, the potential ecotoxicological risk posed by CTR and its TPs to different trophic levels of aquatic organisms was evaluated by means of risk quotients. PMID:27459150

  15. Complicating factors in safety testing of drug metabolites: Kinetic differences between generated and preformed metabolites

    SciTech Connect

    Prueksaritanont, Thomayant . E-mail: thomayant_prueksaritanont@merck.com; Lin, Jiunn H.; Baillie, Thomas A.

    2006-12-01

    This paper aims to provide a scientifically based perspective on issues surrounding the proposed toxicology testing of synthetic drug metabolites as a means of ensuring adequate nonclinical safety evaluation of drug candidates that generate metabolites considered either to be unique to humans or are present at much higher levels in humans than in preclinical species. We put forward a number of theoretical considerations and present several specific examples where the kinetic behavior of a preformed metabolite given to animals or humans differs from that of the corresponding metabolite generated endogenously from its parent. The potential ramifications of this phenomenon are that the results of toxicity testing of the preformed metabolite may be misleading and fail to characterize the true toxicological contribution of the metabolite when formed from the parent. It is anticipated that such complications would be evident in situations where (a) differences exist in the accumulation of the preformed versus generated metabolites in specific tissues, and (b) the metabolite undergoes sequential metabolism to a downstream product that is toxic, leading to differences in tissue-specific toxicity. Owing to the complex nature of this subject, there is a need to treat drug metabolite issues in safety assessment on a case-by-case basis, in which a knowledge of metabolite kinetics is employed to validate experimental paradigms that entail administration of preformed metabolites to animal models.

  16. Structural requirements for activation of the 5-oxo-6E,8Z, 11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) receptor: identification of a mead acid metabolite with potent agonist activity.

    PubMed

    Patel, Pranav; Cossette, Chantal; Anumolu, Jaganmohan R; Gravel, Sylvie; Lesimple, Alain; Mamer, Orval A; Rokach, Joshua; Powell, William S

    2008-05-01

    The 5-lipoxygenase product 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) is a potent chemoattractant for neutrophils and eosinophils, and its actions are mediated by the oxoeicosanoid (OXE) receptor, a member of the G protein-coupled receptor family. To define the requirements for activation of the OXE receptor, we have synthesized a series of 5-oxo-6E,8Z-dienoic acids with chain lengths between 12 and 20 carbons, as well as a series of 20-carbon 5-oxo fatty acids, either fully saturated or containing between one and five double bonds. The effects of these compounds on neutrophils (calcium mobilization, CD11b expression, and cell migration) and eosinophils (actin polymerization) were compared with those of 5-oxo-ETE. The C12 and C14 analogs were without appreciable activity, whereas the C16 5-oxo-dienoic acid was a weak partial agonist. In contrast, the corresponding C18 analog (5-oxo-18:2) was nearly as potent as 5-oxo-ETE. Among the C20 analogs, the fully saturated compound had virtually no activity, whereas 5-oxo-6E-eicosenoic acid had only weak agonist activity. In contrast, 5-oxo-6E,8Z,11Z-eicosatrienoic acid (5-oxo-20:3) and its 8-trans isomer were approximately equipotent with 5-oxo-ETE in activating granulocytes. Because of the potent effects of 5-oxo-20:3, we investigated its formation from Mead acid (5Z,8Z,11Z-eicosatrienoic acid), which accumulates in dietary essential fatty acid deficiency, by neutrophils. The main Mead acid metabolite identified was 5-hydroxy-6,8,11-eicosatrienoic acid, followed by 5-oxo-20:3 and two 6-trans isomers of leukotriene B(3). We conclude that optimal activation of the OXE receptor is achieved with 5-oxo-ETE, 5-oxo-18:2, and 5-oxo-20:3, and that the latter compound could potentially be formed under conditions of essential fatty acid deficiency. PMID:18292294

  17. In Vivo Pharmacodynamic Evaluation of an FtsZ Inhibitor, TXA-709, and Its Active Metabolite, TXA-707, in a Murine Neutropenic Thigh Infection Model

    PubMed Central

    Lepak, Alexander J.; Parhi, Ajit; Madison, Michaela; Marchillo, Karen; VanHecker, Jamie

    2015-01-01

    Antibiotics with novel mechanisms of action are urgently needed. Processes of cellular division are attractive targets for new drug development. FtsZ, an integral protein involved in cell cytokinesis, is a representative example. In the present study, the pharmacodynamic (PD) activity of an FtsZ inhibitor, TXA-709, and its active metabolite, TXA-707, was evaluated in the neutropenic murine thigh infection model against 5 Staphylococcus aureus isolates, including both methicillin-susceptible and methicillin-resistant isolates. The pharmacokinetics (PK) of the TXA-707 active metabolite were examined after oral administration of the TXA-709 prodrug at 10, 40, and 160 mg/kg of body weight. The half-life ranged from 3.2 to 4.4 h, and the area under the concentration-time curve (AUC) and maximum concentration of drug in serum (Cmax) were relatively linear over the doses studied. All organisms exhibited an MIC of 1 mg/liter. Dose fractionation demonstrated the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) to be the PD index most closely linked to efficacy (R2 = 0.72). Dose-dependent activity was demonstrated against all 5 isolates, and the methicillin-resistance phenotype did not alter the pharmacokinetic/pharmacodynamic (PK/PD) targets. Net stasis was achieved against all isolates and a 1-log10 kill level against 4 isolates. PD targets included total drug 24-h AUC/MIC values of 122 for net stasis and 243 for 1-log10 killing. TXA-709 and TXA-707 are a promising novel antibacterial class and compound for S. aureus infections. These results should prove useful for design of clinical dosing regimen trials. PMID:26259789

  18. Wound healing activity of topical application forms based on ayurveda.

    PubMed

    Datta, Hema Sharma; Mitra, Shankar Kumar; Patwardhan, Bhushan

    2011-01-01

    The traditional Indian medicine-Ayurveda, describes various herbs, fats, oils and minerals with anti-aging as well as wound healing properties. With aging, numerous changes occur in skin, including decrease in tissue cell regeneration, decrease in collagen content, loss of skin elasticity and mechanical strength. We prepared five topical anti-aging formulations using cow ghee, flax seed oil, Phyllanthus emblica fruits, Shorea robusta resin, Yashada bhasma as study materials. For preliminary efficacy evaluation of the anti-aging activity we chose excision and incision wound healing animal models and studied the parameters including wound contraction, collagen content and skin breaking strength which in turn is indicative of the tissue cell regeneration capacity, collagenation capacity and mechanical strength of skin. The group treated with the formulations containing Yashada bhasma along with Shorea robusta resin and flax seed oil showed significantly better wound contraction (P < .01), higher collagen content (P < .05) and better skin breaking strength (P < .01) as compared to control group; thus proposing them to be effective prospective anti-aging formulations. PMID:19252191

  19. Wound Healing Activity of Topical Application Forms Based on Ayurveda

    PubMed Central

    Datta, Hema Sharma; Mitra, Shankar Kumar; Patwardhan, Bhushan

    2011-01-01

    The traditional Indian medicine—Ayurveda, describes various herbs, fats, oils and minerals with anti-aging as well as wound healing properties. With aging, numerous changes occur in skin, including decrease in tissue cell regeneration, decrease in collagen content, loss of skin elasticity and mechanical strength. We prepared five topical anti-aging formulations using cow ghee, flax seed oil, Phyllanthus emblica fruits, Shorea robusta resin, Yashada bhasma as study materials. For preliminary efficacy evaluation of the anti-aging activity we chose excision and incision wound healing animal models and studied the parameters including wound contraction, collagen content and skin breaking strength which in turn is indicative of the tissue cell regeneration capacity, collagenation capacity and mechanical strength of skin. The group treated with the formulations containing Yashada bhasma along with Shorea robusta resin and flax seed oil showed significantly better wound contraction (P < .01), higher collagen content (P < .05) and better skin breaking strength (P < .01) as compared to control group; thus proposing them to be effective prospective anti-aging formulations. PMID:19252191

  20. [L forms of Staphylococcus aureus. Behavior of coagulase, hemolytic and desoxyribonuclease activities and antibiotic sensitivity].

    PubMed

    Loschiavo, F; Giarrizzo, S

    1977-01-01

    L Forms derived from strains of coagulase positive Staphylococcus aureus, have, on the whole, preserved their DNAsic, haemolitic and coagulastic activities. L. forms showed high resistence to antibiotics acting on the bacterial cell-wall. The sensibility to other antibiotics was, roughly, analogous for the L forms as well as for the bacterial strains ones, with the exception of the clortetraciclin and the diidrostreptomicin, ehich proved to be comparatively more active on the L forms. PMID:614141

  1. Analysis of prasugrel active metabolite R-138727 in human plasma: a sensitive, highly selective and fast LC-MS/MS method.

    PubMed

    Kakarla, Sreekanth; Datla, Peda Varma; Kodali, Geetha; Seru, Ganapaty

    2016-05-01

    A cost effective, sensitive, simple, and rapid high-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of the prasugrel metabolite in human plasma. Following solid phase extraction, the analyte (prasugrel active metabolite; R-138727) and internal standard (emtricitabine) were separated using a mobile phase in an isocratic elution mode on a reverse phase C18 column and were analyzed by an LC-MS/MS in the multiple reaction monitoring mode using the respective [M+H](+) ions, m/z 498.3-206.0 for R-138727 and m/z 248.2-130.1 for the internal standard. The assay exhibited a linear dynamic range of 0.2-120ng/mL. The lower limit of quantification was 0.2ng/mL with a relative standard deviation of 5.0%. This LC-MS/MS method was validated with intra-batch and inter-batch precision and accuracy. Results for precision and accuracy are in range of 3.9-9.6% and 95.2-102.2% respectively. This validated method is simple and repeatable to use in bioequivalence/pharmacokinetic studies. PMID:27038402

  2. How PBDEs Are Transformed into Dihydroxylated and Dioxin Metabolites Catalyzed by the Active Center of Cytochrome P450s: A DFT Study.

    PubMed

    Fu, Zhiqiang; Wang, Yong; Chen, Jingwen; Wang, Zhongyu; Wang, Xingbao

    2016-08-01

    Predicting metabolism of chemicals and potential toxicities of relevant metabolites remains a vital and difficult task in risk assessment. Recent findings suggested that polybrominated diphenyl ethers (PBDEs) can be transformed into dihydroxylated and dioxin metabolites catalyzed by cytochrome P450 enzymes (CYPs), whereas the mechanisms pertinent to these transformations remain largely unknown. Here, by means of density functional theory (DFT) calculations, we probed the metabolic pathways of 2,2',4,4'-tetraBDE (BDE-47) using the active center model of CYPs (Compound I). Results show that BDE-47 is first oxidized to monohydroxylated products (HO-BDEs), wherein a keto-enol tautomerism is identified for rearrangement of the cyclohexenone intermediate. Dihydroxylation with HO-BDEs as precursors, has a unique phenolic H-abstraction and hydroxyl rebound pathway that is distinct from that for monohydroxylation, which accounts for the absence of epoxides in in vitro studies. Furthermore, we found only dihydroxylated PBDEs with heterophenyl -OH substituents ortho- and meta- to the ether bond serve as precursors for dioxins, which are evolved from aryl biradical coupling of diketone intermediates that are produced from dehydrogenation of the dihydroxylated PBDEs by Compound I. This study may enlighten the development of computational models that afford mechanism-based prediction of the xenobiotic biotransformation catalyzed by CYPs. PMID:27363260

  3. Relative plasma levels of the cardioprotective drug dexrazoxane and its two active ring-opened metabolites in the rat.

    PubMed

    Hasinoff, B B; Aoyama, R G

    1999-02-01

    A postcolumn derivatization reversed-phase high-pressure liquid chromatography method has been developed to detect and separate the one-ring open intermediates of dexrazoxane (ICRF-187) in blood plasma. Dexrazoxane is clinically used as a doxorubicin cardioprotective agent and may act by preventing iron-based oxygen-free radical damage through the iron-chelating ability of its one-ring open intermediates and its fully rings opened hydrolysis product ADR-925. Little is known of the in vivo metabolism of dexrazoxane to its one-ring open intermediates, which may be two of the active forms of dexrazoxane. The one-ring open intermediates were detected within 5 min of i.v. administration of dexrazoxane to rats, suggesting that dexrazoxane is rapidly metabolized in vivo. The plasma concentrations of the one-ring open intermediates varied from 4 to 9% and 6 to 24% of the dexrazoxane concentrations at 5 and 120 min, respectively. The relatively small changes in the levels of the one-ring open intermediates with time suggest that a dynamic steady state is occurring. The ratio of the concentrations of the two one-ring open intermediates was similar to that previously seen for the in vitro dihydropyrimidine amidohydrolase-catalyzed hydrolysis of dexrazoxane. These results are consistent with the hypothesis that dihydropyrimidine amidohydrolase in the liver and kidney is responsible for the metabolism of dexrazoxane in the rat. PMID:9929514

  4. Structure-activity relationship in the mutagenicity and cytotoxicity of putative metabolites and related analogs of benzene derived from the valence tautomers benzene oxide and oxepin

    SciTech Connect

    Stark, A.A.; Rastetter, W.H.

    1996-12-31

    A series of putative metabolites and related analogs of benzene, derived from the valence tautomers benzene oxide and oxepin, was tested for mutagenicity (reversions to histidine prototrophy and forward mutations to resistance to 8-azaguanine) and for cytotoxicity by the Ames Salmonella mutagenicity test. Benzene was not mutagenic in either assay. The benzene oxide-oxepin system and benzene dihydrodial induced point mutations but not frameshifts. 4,5-sym-Oxepin oxide, which is a putative metabolite of the oxepin valence tautomer; 3,6-diazo-cyclohexane-1,6-3,4-dioxide, a synthetic precursor of sym-oxepin oxide; and transoid-4,11-dioxatricyclo(5.1 0)undeca-1,6-diene, a stable bridgehead diene analog of sym-oxepin oxide, were toxic but not mutagenic in both assays. 4H-Pyran-4-=carboxaldehyde, a stable acid catalyzed rearrangement product of sym-oxepin oxide, was not mutagenic and much less cytotoxic than sym-oxepin oxide. Stable analogs of the valence tautomer benzene oxide, namely syn-indan-3a,7a-oxide and syn-2-hydroxyindan-3a,7a-oxide, were mutagenic and induced point mutations. All compounds were cytotoxic to Salmonella. Firstly, the apparent decay times of these chemicals, especially that of sym-oxepin oxide, were surprisingly longer than expected, as judged by quantitative plate diffusion assays. Secondly, it is concluded that if benzene oxide is further metabolized in its oxepin tautomeric form, toxic but not mutagenic products are formed. Thirdly, the relatively weak mutagenicity of benzene oxide may be mainly due to its instability and corresponding low probability to reach intracellular polynucleotide targets, whereas stable analogs of benzene oxide are relatively more potent mutagens. 48 refs., 4 figs., 3 tabs.

  5. Challenges and solutions in the bioanalysis of BMS-986094 and its metabolites including a highly polar, active nucleoside triphosphate in plasma and tissues using LC-MS/MS.

    PubMed

    Liu, Ang; Lute, John; Gu, Huidong; Wang, Bonnie; Trouba, Kevin J; Arnold, Mark E; Aubry, Anne-Françoise; Wang, Jian

    2015-09-01

    BMS-986094, a nucleotide polymerase inhibitor of the hepatitis C virus, was withdrawn from clinical trials because of a serious safety issue. To investigate a potential association between drug/metabolite exposure and toxicity in evaluations conducted after the termination of the BMS-986094 development program, it was essential to determine the levels of BMS-986094 and its major metabolites INX-08032, INX-08144 and INX-09054 in circulation and the active nucleoside triphosphate INX-09114 in target and non-target tissues. However, there were many challenges in the bioanalysis of these compounds. The chromatography challenge for the extremely polar nucleoside triphosphate was solved by applying mixed-mode chromatography which combined anion exchange and reversed-phase interactions. The LC conditions provided adequate retention and good peak shape of the analyte and showed good robustness. A strategy using simultaneous extraction but separate LC analysis of the prodrug BMS-986094 and its major circulating metabolites was used to overcome a carryover issue of the hydrophobic prodrug while still achieving good chromatography of the polar metabolites. In addition, the nucleotide analytes were not stable in the presence of endogenous enzymes. Low pH and low temperature were required for blood collection and plasma sample processing. However, the use of phosphatase inhibitor and immediate homogenization and extraction were critical for the quantitative analysis of the active triphosphate, INX-09114, in tissue samples. To alleviate the bioanalytical complexity caused by multiple analytes, different matrices, and various species, a fit-for-purpose approach to assay validation was implemented based on the needs of drug safety assessment in non-clinical (GLP or non-GLP) studies. The assay for INX-08032 was fully validated in plasma of toxicology species. The lower limit of quantification was 1.00ng/mL and the linear curve range was 1.00-500.00ng/mL using a weighted (1/x(2

  6. Induction of UDP-glucuronosyltransferase 2B15 gene expression by the major active metabolites of tamoxifen, 4-hydroxytamoxifen and endoxifen, in breast cancer cells.

    PubMed

    Chanawong, Apichaya; Hu, Dong Gui; Meech, Robyn; Mackenzie, Peter I; McKinnon, Ross A

    2015-06-01

    We previously reported upregulation of UGT2B15 by 17β-estradiol in breast cancer MCF7 cells via binding of the estrogen receptor α (ERα) to an estrogen response unit (ERU) in the proximal UGT2B15 promoter. In the present study, we show that this ERα-mediated upregulation was significantly reduced by two ER antagonists (fulvestrant and raloxifene) but was not affected by a third ER antagonist, 4-hydroxytamoxifen (4-OHTAM), a major active tamoxifen (TAM) metabolite. Furthermore, we found that, similar to 17β-estradiol, 4-OHTAM and endoxifen (another major active TAM metabolite) elevated UGT2B15 mRNA levels, and that this stimulation was significantly abrogated by fulvestrant. Further experiments using 4-OHTAM revealed a critical role for ERα in this regulation. Specifically; knockdown of ERα expression by anti-ERα small interfering RNA reduced the 4-OHTAM-mediated induction of UGT2B15 expression; 4-OHTAM activated the wild-type but not the ERU-mutated UGT2B15 promoter; and chromatin immunoprecipitation assays showed increased ERα occupancy at the UGT2B15 ERU in MCF7 cells upon exposure to 4-OHTAM. Together, these data indicate that both 17β-estradiol and the antiestrogen 4-OHTAM upregulate UGT2B15 in MCF7 cells via the same ERα-signaling pathway. This is consistent with previous observations that both 17β-estradiol and TAM upregulate a common set of genes in MCF7 cells via the ER-signaling pathway. As 4-OHTAM is a UGT2B15 substrate, the upregulation of UGT2B15 by 4-OHTAM in target breast cancer cells is likely to enhance local metabolism and inactivation of 4-OHTAM within the tumor. This represents a potential mechanism that may reduce TAM therapeutic efficacy or even contribute to the development of acquired TAM resistance. PMID:25795461

  7. Trapping of a Cross-link Formed by a Major Purine Adduct of a Metabolite of the Carcinogen N-Nitrosomorpholine by Inorganic and Biological Reductants

    PubMed Central

    Koissi, Niangoran; Fishbein, James C.

    2013-01-01

    3-Hydroperoxy-N-nitrosomorpholine in buffered aqueous media in the presence of calf thymus DNA was treated with a phosphine reductant to generate the transient α-hydroxynitrosamine and subsequent diazonium ion that alkylated the DNA, as previously reported. Subsequent addition of hydride donors, for 30 min, followed by acid hydrolysis of the mixture allowed detection and quantification of 6-(2-(2-((9H-purin-6-yl)amino)ethoxy)ethoxy)-9H-purin-2-amine, the reduced cross-link formed from deposition, via the diazonium ion, of a 3-oxa-pentanal fragment on O6-Gua, and condensation with N6-Ade, presumably in the vicinity. Decreasing temperature of the reactions and decreasing pH modestly increased the yields of trapped crosslink. Among three borohydride reductants, NaNCBH3 is superior, being ∼4 times more effective on a molar basis, as opposed to a hydride equivalent basis, than NaBH4 or Na(AcO)3BH. For trapping with NaNCBH3, it is deduced that the reaction likely occurs with the iminium ion that is in protonic equilibrium with its conjugate base imine. In an experiment in which the hydroperoxide was decomposed and NaNCBH3 was introduced after various times, the amount of cross-link was observed to increase, nearly linearly, by about four-fold over one week. These data indicate that there are a minimum of 2 populations of cross-links, one that forms rapidly, in minutes, and another that grows in with time, over days. Reduced nicotinamide co-factors and ascorbate are observed to effect reduction (over 3 days) of the cross-links confirming the possibility that otherwise reversible cross-links might be immortalized under biological conditions. PMID:23587048

  8. The role of leukocyte-generated reactive metabolites in the pathogenesis of idiosyncratic drug reactions.

    PubMed

    Uetrecht, J P

    1992-01-01

    Evidence strongly suggests that many adverse drug reactions, including idiosyncratic drug reactions, involve reactive metabolites. Furthermore, certain functional groups, which are readily oxidized to reactive metabolites, are associated with a high incidence of adverse reactions. Most drugs can probably form reactive metabolites, but a simple comparison of covalent binding in vitro is unlikely to provide an accurate indication of the relative risk of a drug causing an idiosyncratic reaction because it does not provide an indication of how efficiently the metabolite is detoxified in vivo. In addition, the incidence and nature of adverse reactions associated with a given drug is probably determined in large measure by the location of reactive metabolite formation, as well as the chemical reactivity of the reactive metabolite. Such factors will determine which macromolecules the metabolites will bind to, and it is known that covalent binding to some proteins, such as those in the leukocyte membrane, is much more likely to lead to an immune-mediated reaction or other type of toxicity. Some reactive metabolites, such as acyl glucuronides, circulate freely and could lead to adverse reactions in almost any organ; however, most reactive metabolites have a short biological half-life, and although small amounts may escape the organ where they are formed, these metabolites are unlikely to reach sufficient concentrations to cause toxicity in other organs. Many idiosyncratic drug reactions involve leukocytes, especially agranulocytosis and drug-induced lupus. We and others have demonstrated that drugs can be metabolized by activated neutrophils and monocytes to reactive metabolites. The major reaction appears to be reaction with leukocyte-generated hypochlorous acid. Hypochlorous acid is quite reactive, and therefore it is likely that many other drugs will be found that are metabolized by activated leukocytes. Some neutrophil precursors contain myeloperoxidase and the NADPH

  9. Toxicological significance of dihydrodiol metabolites

    SciTech Connect

    Hsia, M.T.

    1982-01-01

    Dihydrodiols are often found as the major organic-extractable metabolites of various olefinic or aromatic xenobiotics in many biological samples. Studies on the chemistry of dihydrodiol metabolites have provided insight into the pharmacokinetic behavior and the mode of action of the parent compound. The toxicology of dihydrodiol is more complex than what can be deduced solely on the basis of diminished bioavailability of the epoxide precursor, and the increased hydrophilicity associated with the dihydrodiol moiety. Dihydrodiols can be intrinsically toxic and may even represent metabolically activated species. Some of the dihydrodiol metabolites may still retain sufficient lipophilic character to serve again as substrates for microsomal oxygenases. Because of the tremendous chemical and biological diversity that existed among the various dihydrodiols, more mechanistic studies are needed to examine the toxicological properties of these compounds. It may be premature to conclude dihydrodiol formation as purely a detoxification route for xenobioties.

  10. A new and fast DLLME-CE method for the enantioselective analysis of zopiclone and its active metabolite after fungal biotransformation.

    PubMed

    de Albuquerque, Nayara Cristina Perez; de Gaitani, Cristiane Masetto; de Oliveira, Anderson Rodrigo Moraes

    2015-05-10

    Zopiclone (ZO) is a chiral drug that undergoes extensive metabolism to N-desmethylzopiclone (N-Des-ZO) and zopiclone-N-oxide (N-Ox-ZO). Pharmacological studies have shown (S)-N-Des-ZO metabolite presents anxiolytic activity and a patent for this metabolite was requested for anxiety treatment and related disorders. In this context, biotransformation employing fungi may be a promising strategy to obtain N-Des-ZO. To perform the biotransformation study in this work, an enantioselective method based on capillary electrophoresis (CE) and dispersive liquid-liquid microextraction (DLLME) was developed. CE analyses were carried out in sodium phosphate buffer (pH 2.5; 50mmolL(-1)) containing 0.5% (w/v) carboxymethyl-β-CD, at a constant voltage of +25kV. DLLME was conducted using 2mL of liquid culture medium pH 9.5. Chloroform (100μL) and methanol (300μL) were employed as extraction and disperser solvent, respectively. After CE and DLLME optimization, the analytical method was fully validated. The method was linear over a concentration range of 90-6000ngmL(-1) for each ZO enantiomer (r>0.999) and 50-1000ngmL(-1) for each N-Des-ZO enantiomer (r>0.998). Absolute recovery of 51 and 82% was achieved for N-Des-ZO and ZO, respectively. The accuracy and precision results agreed with the EMA (European Medicines Agency) guideline, and so did the stability study. Application of the developed method in a biotransformation study was conducted in order to investigate the ability of fungi, belonging to the genus Cunninghamella, in metabolizing ZO chiral drug. Fungi Cunninghamella elegans ATCC 10028B and Cunninghamella echinulata var elegans ATCC 8688A demonstrated to be able to enantioselectively biotransform ZO to its active metabolite, N-Des-ZO. Therefore, the proposed goals of this work, i.e. a fast DLLME-CE method and an outstanding strategy to obtain N-Des-ZO, were successfully attained. PMID:25778930

  11. Isolation of Secondary Metabolites from the Soil-Derived Fungus Clonostachys rosea YRS-06, a Biological Control Agent, and Evaluation of Antibacterial Activity.

    PubMed

    Zhai, Ming-Ming; Qi, Feng-Ming; Li, Jie; Jiang, Chun-Xiao; Hou, Yue; Shi, Yan-Ping; Di, Duo-Long; Zhang, Ji-Wen; Wu, Quan-Xiang

    2016-03-23

    The fungus Clonostachys rosea is widely distributed all over the world. The destructive force of this fungus, as a biological control agent, is very strong to lots of plant pathogenic fungi. As part of the ongoing search for antibiotics from fungi obtained from soil samples, the secondary metabolites of C. rosea YRS-06 were investigated. Through efficient bioassay-guided isolation, three new bisorbicillinoids possessing open-ended cage structures, tetrahydrotrichodimer ether (1) and dihydrotrichodimer ether A and B (2 and 3), and 12 known compounds were obtained. Their structures were determined via extensive NMR, HR-ESI-MS, and CD spectroscopic analyses and X-ray diffraction data. Compounds 1-3 are rare bisorbicillinoids with a γ-pyrone moiety. The biological properties of 1-15 were evaluated against six different Gram-positive and Gram-negative bacteria. Bisorbicillinoids, 2-5, and TMC-151 C and E, 14 and 15, showed potent antibacterial activity. PMID:26974009

  12. The large-leaved Kudingcha (Ilex latifolia Thunb and Ilex kudingcha C.J. Tseng): a traditional Chinese tea with plentiful secondary metabolites and potential biological activities.

    PubMed

    Li, Li; Xu, Li J; Ma, Gui Z; Dong, Yin M; Peng, Yong; Xiao, Pei G

    2013-07-01

    In China, Kudingcha has been used for almost 2,000 years as a tea to quench thirst, remove phlegm, refresh the mind, and improve eyesight. The group of large-leaved Kudingcha is coveted for its potential effects on lipid metabolism, which are attributed to the presence of characteristic ingredients. This contribution reviews studies from the past few decades regarding the plant characteristics, ethnobotanical usages, chemical constituents, and related biological activities of the large-leaved Kudingcha (Ilex latifolia Thunb and Ilex kudingcha C.J. Tseng). Triterpenoids, phenolic acids, flavonoids, and essential oils are the main metabolites in the large-leaved Kudingcha, and these ingredients protect the vascular system, regulate lipid metabolism, and have antioxidant, hypoglycemic, and anti-tumor effects. Moreover, large-leaved Kudingcha shares several properties with the popular green tea and the Yerba maté from South America. PMID:23529541

  13. Participation of covalent modification of Keap1 in the activation of Nrf2 by tert-butylbenzoquinone, an electrophilic metabolite of butylated hydroxyanisole

    SciTech Connect

    Abiko, Yumi; Miura, Takashi; Phuc, Bui Hoang; Shinkai, Yasuhiro; Kumagai, Yoshito

    2011-08-15

    Butylated hydroxyanisole (BHA) is an antioxidant and class-2B carcinogen. It is biotransformed to tert-butylhydroquinone (TBHQ), which readily auto-oxidizes to the electrophilic metabolite tert-butylbenzoquinone (TBQ). BHA and TBHQ activate Nrf2, a transcription factor that is negatively regulated by Keap1 and plays a role in the initial response to chemicals causing oxidative or electrophilic stress, although, the exact mechanism of Nrf2 activation remains unclear. Here, we examined the role of TBQ in Nrf2 activation. Exposure of RAW264.7 cells to TBQ activated Nrf2 and up-regulated its downstream proteins; under these conditions, TBQ produced cellular reactive oxygen species (ROS). However, while pretreatment with catalase conjugated with polyethylene glycol (PEG-CAT) did not affect the TBQ-induced activation of Nrf2, the ROS generation caused by TBQ was entirely abolished by PEG-CAT, suggesting that ROS is not the dominant factor for TBQ-dependent Nrf2 activation. A click chemistry technique indicated that TBQ chemically modifies Keap1. Furthermore, ultrahigh performance liquid chromatography-tandem mass spectrometry analysis with purified Keap1 revealed that TBQ covalently binds to Keap1 through Cys23, Cys151, Cys226, and Cys368. These results suggest that TBQ derived from BHA activates Nrf2 through electrophilic modification of Keap1 rather than ROS formation. - Research Highlights: > tert-Butylbenzoquinone (TBQ) activates Nrf2 in RAW264.7 cells. > ROS is not essential factor for Nrf2 activation caused by TBQ. > TBQ covalently binds to Keap1 through reactive thiols, resulting in Nrf2 activation.

  14. Composition and topology of activity cliff clusters formed by bioactive compounds.

    PubMed

    Stumpfe, Dagmar; Dimova, Dilyana; Bajorath, Jürgen

    2014-02-24

    The assessment of activity cliffs has thus far mostly focused on compound pairs, although the majority of activity cliffs are not formed in isolation but in a coordinated manner involving multiple active compounds and cliffs. However, the composition of coordinated activity cliff configurations and their topologies are unknown. Therefore, we have identified all activity cliff configurations formed by currently available bioactive compounds and analyzed them in network representations where activity cliff configurations occur as clusters. The composition, topology, frequency of occurrence, and target distribution of activity cliff clusters have been determined. A limited number of large cliff clusters with unique topologies were identified that were centers of activity cliff formation. These clusters originated from a small number of target sets. However, most clusters were of small to moderate size. Three basic topologies were sufficient to describe recurrent activity cliff cluster motifs/topologies. For example, frequently occurring clusters with star topology determined the scale-free character of the global activity cliff network and represented a characteristic activity cliff configuration. Large clusters with complex topology were often found to contain different combinations of basic topologies. Our study provides a first view of activity cliff configurations formed by currently available bioactive compounds and of the recurrent topologies of activity cliff clusters. Activity cliff clusters of defined topology can be selected, and from compounds forming the clusters, SAR information can be obtained. The SAR information of activity cliff clusters sharing a/one specific activity and topology can be compared. PMID:24437577

  15. Oxidized Metabolites of 20-Hydroxyecdysone and Their Activity on Skeletal Muscle Cells: Preparation of a Pair of Desmotropes with Opposite Bioactivities.

    PubMed

    Csábi, József; Hsieh, Tusty-Jiuan; Hasanpour, Feria; Martins, Ana; Kele, Zoltán; Gáti, Tamás; Simon, András; Tóth, Gábor; Hunyadi, Attila

    2015-10-23

    Increasing the activation of protein kinase B (Akt) has been suggested as a key signaling step in the nonhormonal anabolic activity of the phytoecdysteroid 20-hydroxyecdysone (20E) in mammals. Base-catalyzed autoxidation of this compound was shown previously to yield interesting B-ring-modified analogues. Herein is reported a thorough study on this reaction, resulting in the preparation and complete NMR spectroscopic assignments of calonysterone (5) and its previously overlooked desmotropic pair (7), along with two new sensitive metabolites of 20E. The two isomers showed considerable stability in solution. Time dependency of the reaction for yield optimization is also presented; by means of analytical HPLC, the two desmotropes can reach a maximum combined yield of >90%. The activity of these compounds on Akt phosphorylation was tested in murine skeletal muscle cells. Compounds 2 and 5 showed more potent activity than 20E in increasing Akt activation, while compound 7 exerted an opposite effect. As such, the present study provides the first direct evidence for a pair of desmotropes exerting significantly different bioactivities. PMID:26465254

  16. The Inotropic Effect of the Active Metabolite of Levosimendan, OR-1896, Is Mediated through Inhibition of PDE3 in Rat Ventricular Myocardium

    PubMed Central

    Ørstavik, Øivind; Manfra, Ornella; Andressen, Kjetil Wessel; Andersen, Geir Øystein; Skomedal, Tor; Osnes, Jan-Bjørn; Levy, Finn Olav; Krobert, Kurt Allen

    2015-01-01

    Aims We recently published that the positive inotropic response (PIR) to levosimendan can be fully accounted for by phosphodiesterase (PDE) inhibition in both failing human heart and normal rat heart. To determine if the PIR of the active metabolite OR-1896, an important mediator of the long-term clinical effects of levosimendan, also results from PDE3 inhibition, we compared the effects of OR-1896, a representative Ca2+ sensitizer EMD57033 (EMD), levosimendan and other PDE inhibitors. Methods Contractile force was measured in rat ventricular strips. PDE assay was conducted on rat ventricular homogenate. cAMP was measured using RII_epac FRET-based sensors. Results OR-1896 evoked a maximum PIR of 33±10% above basal at 1 μM. This response was amplified in the presence of the PDE4 inhibitor rolipram (89±14%) and absent in the presence of the PDE3 inhibitors cilostamide (0.5±5.3%) or milrinone (3.2±4.4%). The PIR was accompanied by a lusitropic response, and both were reversed by muscarinic receptor stimulation with carbachol and absent in the presence of β-AR blockade with timolol. OR-1896 inhibited PDE activity and increased cAMP levels at concentrations giving PIRs. OR-1896 did not sensitize the concentration-response relationship to extracellular Ca2+. Levosimendan, OR-1896 and EMD all increased the sensitivity to β-AR stimulation. The combination of either EMD and levosimendan or EMD and OR-1896 further sensitized the response, indicating at least two different mechanisms responsible for the sensitization. Only EMD sensitized the α1-AR response. Conclusion The observed PIR to OR-1896 in rat ventricular strips is mediated through PDE3 inhibition, enhancing cAMP-mediated effects. These results further reinforce our previous finding that Ca2+ sensitization does not play a significant role in the inotropic (and lusitropic) effect of levosimendan, nor of its main metabolite OR-1896. PMID:25738589

  17. Enhancement of Anti-Inflammatory Activity of Aloe vera Adventitious Root Extracts through the Alteration of Primary and Secondary Metabolites via Salicylic Acid Elicitation

    PubMed Central

    Lee, Yun Sun; Ju, Hyun Kyoung; Kim, Yeon Jeong; Lim, Tae-Gyu; Uddin, Md Romij; Kim, Yeon Bok; Baek, Jin Hong; Kwon, Sung Won; Lee, Ki Won; Seo, Hak Soo; Park, Sang Un; Yang, Tae-Jin

    2013-01-01

    Aloe vera (Asphodeloideae) is a medicinal plant in which useful secondary metabolites are plentiful. Among the representative secondary metabolites of Aloe vera are the anthraquinones including aloe emodin and chrysophanol, which are tricyclic aromatic quinones synthesized via a plant-specific type III polyketide biosynthesis pathway. However, it is not yet clear which cellular responses can induce the pathway, leading to production of tricyclic aromatic quinones. In this study, we examined the effect of endogenous elicitors on the type III polyketide biosynthesis pathway and identified the metabolic changes induced in elicitor-treated Aloe vera adventitious roots. Salicylic acid, methyl jasmonate, and ethephon were used to treat Aloe vera adventitious roots cultured on MS liquid media with 0.3 mg/L IBA for 35 days. Aloe emodin and chrysophanol were remarkably increased by the SA treatment, more than 10–11 and 5–13 fold as compared with untreated control, respectively. Ultra-performance liquid chromatography-electrospray ionization mass spectrometry analysis identified a total of 37 SA-induced compounds, including aloe emodin and chrysophanol, and 3 of the compounds were tentatively identified as tricyclic aromatic quinones. Transcript accumulation analysis of polyketide synthase genes and gas chromatography mass spectrometry showed that these secondary metabolic changes resulted from increased expression of octaketide synthase genes and decreases in malonyl-CoA, which is the precursor for the tricyclic aromatic quinone biosynthesis pathway. In addition, anti-inflammatory activity was enhanced in extracts of SA-treated adventitious roots. Our results suggest that SA has an important role in activation of the plant specific-type III polyketide biosynthetic pathway, and therefore that the efficacy of Aloe vera as medicinal agent can be improved through SA treatment. PMID:24358188

  18. A Semiphysiologically Based Pharmacokinetic Modeling Approach to Predict the Dose-Exposure Relationship of an Antiparasitic Prodrug/Active Metabolite Pair

    PubMed Central

    Yan, Grace Zhixia; Generaux, Claudia N.; Yoon, Miyoung; Goldsmith, Rachel B.; Tidwell, Richard R.; Hall, James E.; Olson, Carol A.; Clewell, Harvey J.; Brouwer, Kim L. R.

    2012-01-01

    Dose selection during antiparasitic drug development in animal models and humans traditionally has relied on correlations between plasma concentrations obtained at or below maximally tolerated doses that are efficacious. The objective of this study was to improve the understanding of the relationship between dose and plasma/tissue exposure of the model antiparasitic agent, pafuramidine, using a semiphysiologically based pharmacokinetic (semi-PBPK) modeling approach. Preclinical and clinical data generated during the development of pafuramidine, a prodrug of the active metabolite, furamidine, were used. A whole-body semi-PBPK model for rats was developed based on a whole-liver PBPK model using rat isolated perfused liver data. A whole-body semi-PBPK model for humans was developed on the basis of the whole-body rat model. Scaling factors were calculated using metabolic and transport clearance data generated from rat and human sandwich-cultured hepatocytes. Both whole-body models described pafuramidine and furamidine disposition in plasma and predicted furamidine tissue (liver and kidney) exposure and excretion profiles (biliary and renal). The whole-body models predicted that the intestine contributes significantly (30–40%) to presystemic furamidine formation in both rats and humans. The predicted terminal elimination half-life of furamidine in plasma was 3- to 4-fold longer than that of pafuramidine in rats (170 versus 47 h) and humans (64 versus 19 h). The dose-plasma/tissue exposure relationship for the prodrug/active metabolite pair was determined using the whole-body models. The human model proposed a dose regimen of pafuramidine (40 mg once daily) based on a predefined efficacy-safety index. A similar approach could be used to guide dose-ranging studies in humans for next-in-class compounds. PMID:21953913

  19. [Secondary Metabolites from Marine Microorganisms. I. Secondary Metabolites from Marine Actinomycetes].

    PubMed

    Orlova, T I; Bulgakova, V G; Polin, A N

    2015-01-01

    Review represents data on new active metabolites isolated from marine actinomycetes published in 2007 to 2014. Marine actinomycetes are an unlimited source of novel secondary metabolites with various biological activities. Among them there are antibiotics, anticancer compounds, inhibitors of biochemical processes. PMID:26863742

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  8. Dance as a Fitness Activity: The Impact of Teaching Style and Dance Form.

    ERIC Educational Resources Information Center

    Fromel, Karel; Vasendova, Jana; Stratton, Gareth; Pangrazi, Robert P.

    2002-01-01

    Analyzed the amount of activity, intensity of activity, and attitudes of participants in Czech high school physical education classes taught using different teaching styles and dance forms. Measurements of heart rate and dance intensity and student surveys indicated that teaching style and dance form significantly impacted the intensity and volume…

  9. Characterizing the Peroxisome Proliferator-Activated Receptor (PPARγ) Ligand Binding Potential of Several Major Flame Retardants, Their Metabolites, and Chemical Mixtures in House Dust

    PubMed Central

    Fang, Mingliang; Webster, Thomas F.; Ferguson, P. Lee

    2014-01-01

    Background: Accumulating evidence has shown that some environmental contaminants can alter adipogenesis and act as obesogens. Many of these contaminants act via the activation of the peroxisome proliferator-activated receptor γ (PPARγ) nuclear receptor. Objectives: Our goal was to determine the PPARγ ligand binding potency of several major flame retardants, including polybrominated diphenyl ethers (PBDEs), halogenated phenols and bisphenols, and their metabolites. Ligand binding activity of indoor dust and its bioactivated extracts were also investigated. Methods: We used a commercially available fluorescence polarization ligand binding assay to investigate the binding potency of flame retardants and dust extracts to human PPARγ ligand-binding domain. Rosiglitazone was used as a positive control. Results: Most of the tested compounds exhibited dose-dependent binding to PPARγ. Mono(2-ethylhexyl) tetrabromophthalate, halogenated bisphenols and phenols, and hydroxylated PBDEs were found to be potent PPARγ ligands. The most potent compound was 3-OH-BDE-47, with an IC50 (concentration required to reduce effect by 50%) of 0.24 μM. The extent of halogenation and the position of the hydroxyl group strongly affected binding. In the dust samples, 21 of the 24 samples tested showed significant binding potency at a concentration of 3 mg dust equivalent (DEQ)/mL. A 3–16% increase in PPARγ binding potency was observed following bioactivation of the dust using rat hepatic S9 fractions. Conclusion: Our results suggest that several flame retardants are potential PPARγ ligands and that metabolism may lead to increased binding affinity. The PPARγ binding activity of house dust extracts at levels comparable to human exposure warrants further studies into agonistic or antagonistic activities and their potential health effects. Citation: Fang M, Webster TF, Ferguson PL, Stapleton HM. 2015. Characterizing the peroxisome proliferator-activated receptor (PPARγ) ligand binding

  10. Metabolite kinetics: formation of acetaminophen from deuterated and nondeuterated phenacetin and acetanilide on acetaminophen sulfation kinetics in the perfused rat liver preparation

    SciTech Connect

    Pang, K.S.; Waller, L.; Horning, M.G.; Chan, K.K.

    1982-07-01

    The role of hepatic intrinsic clearance for metabolite formation from various precursors on subsequent metabolite elimination was was investigated in the once-through perfused rat liver preparation. Two pairs of acetaminophen precursors: (/sup 14/C) phenacetin-d5 and (/sup 3/H) phenacetin-do, (/sup 14/C) acetanilide and (/sup 3/H) phenacetin were delivered by constant flow (10 ml/min/liver) either by normal or retrograde perfusion to the rat liver preparations. The extents of acetaminophen sulfation were compared within the same preparation. The data showed that the higher the hepatocellular activity (intrinsic clearance) for acetaminophen formation, the greater the extent of subsequent acetaminophen sulfation. The findings were explained on the basis of blood transit time and metabolite duration time. Because of blood having only a finite transit time in liver, the longer the drug requires for metabolite formation, the less time will remain for metabolite sulfation and the less will be the degree of subsequent sulfation. Conversely, when the drug forms the primary metabolite rapidly, a longer time will remain for the metabolite to be sulfated in liver to result in a greater degree of metabolite sulfation. Finally, the effects of hepatic intrinsic clearances for metabolite formation and zonal distribution of enzyme systems for metabolite formation and elimination in liver are discussed.

  11. In vitro activity of Rutaceae species against the trypomastigote form of Trypanosoma cruzi.

    PubMed

    Mafezoli, J; Vieira, P C; Fernandes, J B; da Silva, M F; de Albuquerque, S

    2000-11-01

    The activity of crude plant extracts of nine species of Rutaceae against the trypomastigote form of Trypanosoma cruzi was evaluated at 4 mg/ml. Thirty-two crude extracts were tested and eight of them showed significant activity (>80%). The most active extract was obtained from the stems of Pilocarpus spicatus (97.3%). Fractionation of the active crude extracts provided 25 fractions which were tested against the trypomastigote form of T. cruzi at 2 mg/ml. Of these six showed significant activity (>80%). The most active fractions (100%) were obtained from the leaves of Almeidea coerulea (butanol fraction) and Conchocarpus inopinatus (dichloromethane fraction). PMID:11025175

  12. Role of aniline metabolites in aniline-induced hemolytic anemia.

    PubMed

    Harrison, J H; Jollow, D J

    1986-09-01

    Hemolytic anemia after aniline and aniline-related drugs such as dapsone and primaquine is thought to be mediated by active/reactive metabolite(s) formed during the hepatic clearance of the parent compounds. To determine whether any of the known metabolites of aniline contribute to the hemolytic response seen in rats given aniline, rats were infused with isologous 51Cr-labeled erythrocytes 24 hr before administration of aniline or aniline metabolites. The time course of blood radioactivity was followed in individual rats by serial sampling from the orbital sinus and the time required for blood radioactivity to fall by 50% (T50Cr) was used as a measure of in vivo erythrocyte survival. Aniline HCl produced a dose-dependent reduction in the T50Cr. Acetanilide also reduced the T50Cr, but was less potent than aniline. Aminophenols (2-, 3- and 4-) in similar doses did not significantly alter the T50Cr. In contrast, phenylhydroxylamine produced a dose-dependent decrease in the T50Cr with approximately 10 times the potency of aniline. The T50Cr was also decreased in a concentration-dependent manner for labeled erythrocytes incubated in vitro with phenylhydroxylamine, then readministered to rats, indicating a direct toxic effect of phenylhydroxylamine on erythrocytes. In addition, the area under the blood time course curve for phenylhydroxylamine plus nitrosobenzene was equivalent in rats administered equitoxic doses of aniline or phenylhydroxylamine, indicating that sufficient phenylhydroxylamine is formed in vivo during aniline clearance to account for aniline's toxicity. These results suggest that phenylhydroxylamine is the active metabolite that mediates aniline-induced hemolytic anemia. PMID:3746658

  13. Antimicrobial, phytotoxic, nematicidal, cytotoxic, and mutagenic activities of 1-hydroxypyrene, the initial metabolite in pyrene metabolism by the basidiomycete Crinipellis stipitaria

    SciTech Connect

    Lambert, M.; Kremer, S.; Anke, H.

    1995-08-01

    In recent years, there has been an increasing interest in the testing fungi for degradation or detoxification of various polycyclic aromatic hydrocarbons (PAHs) and elucidation of the pathways involved. Investigations on microbial metabolism of pyrene are limited to some bacteria and the fungi Cunninghamella elegans, Phanerochaete chrysosporium, Crinipellis stipitaria and Aspergillus niger. The fungal transformation products of pyrene, 1-hydroxypyrene, 1,6-dihydroxypyrene, 1,8-dihydroxypyrene, 1,6-pyrenequinone, 1,8-pyrenequinone and some glucoside conjugates of hydroxylated pyrenes were identified. Until now, only mutagenic activities of some of these metabolites towards Salmonella typhimurium have been reported. Nothing is known about additional biological activities of these compounds, especially their effects on soil organisms are of ecological importance. During bioremediation processes these compounds could accumulate. In the present study we describe the antimicrobial, nematicidal, phytotoxic, cytotoxic and mutagenic activities of 1-hydroxypyrene, the initial transformation product of pyrene metabolization by C. stipitaria and compares this, with the activities of pyrene and benzo[a]pyrene. 15 refs., 1 fig., 4 tabs.

  14. Urinary metabolites of 14C-labeled thyroxine in man

    PubMed Central

    Pittman, Constance S.; Buck, Melvin W.; Chambers, Joseph B.

    1972-01-01

    Studies were carried out to determine the chemical structures of thyroxine metabolites after total deiodination. Normal subjects were given thyroxine labeled with 14C on the nonphenolic ring and the alanine side chain, 8-11 μg/day for 10 days. By paper chromatography of fresh urine, six or more 14C-labeled compounds were separated. The 14C-labeled metabolites were concentrated by passing the urine through a nonionic polymeric adsorbent. Two major thyroxine metabolites were identified. The identification was made by three different methods: (a) chromatography, (b) synthesis of derivatives, and (c) recrystallization to constant specific activity. One 14C-labeled metabolite was identified as thyroacetic acid or 4-phenoxy-(4′-hydroxy) phenyl-acetic acid. Another one was identified as thyronine. Of the total urinary 14C radioactivity, 43.7% was recovered as thyroacetic acid and 19.8% was recovered as thyronine. Approximately one-fifth of each of these metabolites was present in the urine in bound form which released the free metabolites during acid hydrolysis. The average daily excretion of thyroacetic acid was 13.7% of the renal disposal rate of thyroxine, or approximately 7.5 μg/day. The average daily excretion of thyronine was 6.5% of the renal disposal rate of thyroxine or approximately 3.9 μg/day while the urinary iodide made up 64.7% of the renal disposal rate of thyroxine. Our findings provide the needed proof that the major metabolic pathways of thyroxine remove the iodine atoms by substituting hydrogen for iodine and leave the diphenyl ether nucleus intact. PMID:5032524

  15. Validation of an enzyme immunoassay for assessing adrenocortical activity and evaluation of factors that affect levels of fecal glucocorticoid metabolites in two New World primates.

    PubMed

    Rimbach, Rebecca; Heymann, Eckhard W; Link, Andrés; Heistermann, Michael

    2013-09-15

    Non-invasive methods to assess stress hormone output via fecal glucocorticoid metabolites (FGCMs) have become a powerful tool in behavioral studies and conservation biology because they allow exploring the link between behavior, an animal's socio-ecological environment and its adrenocortical activity. However, FGCM levels are influenced by numerous other factors which often confound their interpretation. Thus, before applying these methods, knowledge on the impact of these factors is important. In this study we investigated the effect of (1) time of day, (2) age, (3) sex and (4) female reproductive state on FGCM levels in brown spider monkeys (Ateles hybridus) and red howler monkeys (Alouatta seniculus). Initially, we validated a 11β-hydroxyetiocholanolone enzyme immunoassay for monitoring the physiological stress response via fecal analysis in both species. We determined FGCM levels in fecal samples collected from two and six groups of wild spider monkeys (n=461 samples) and howler monkeys (n=166 samples), respectively. Our analyses revealed a strong effect of time of day on FGCM levels in spider monkeys, but no effect in howler monkeys. Adults of both species had significantly higher FGCM levels than subadults. In neither of the two species we found a sex-effect on FGCM output. Reproductive condition strongly affected FGCM levels in female spider monkeys which showed increasing concentrations with progressing gestation. This was not investigated in female howler monkeys due to an insufficient sample size. Our data indicate that the influence of the tested factors on fecal glucocorticoid metabolite output is species-specific, and that these variables need to be considered when interpreting FGCM levels in the species. PMID:23707497

  16. Novel concept in the mechanism of injury and protection of gastric mucosa: role of renin-angiotensin system and active metabolites of angiotensin.

    PubMed

    Brzozowski, T; Ptak-Belowska, A; Kwiecien, S; Krzysiek-Maczka, G; Strzalka, M; Drozdowicz, D; Pajdo, R; Olszanecki, R; Korbut, R; Konturek, S J; Pawlik, W W

    2012-01-01

    The term cytoprotection pioneered by Robert and colleagues has been introduced to describe the remarkable ability of endogenous and exogenous prostaglandins (PGs) to prevent acute gastric hemorrhagic lesions induced by noxious stimuli such as ethanol, bile acids, hiperosmolar solutions and nonsteroidal anti-inflammatory agents such as aspirin. Since that time many factors were implicated to possess gastroprotective properties such as growth factors including epidermal growth factor (EGF) and transforming factor alpha (TGFα), vasodilatory mediators such as nitric oxide (NO) and calcitonin gene related peptide (CGRP) as well as appetite gut hormones including gastrin and cholecystokinin (CCK), leptin and recently ghrelin. This protective action of gut peptides has been attributed to the release of PG but question remains whether another peptide angiotensin, the classic component of the systemic and local renin-angiotensin system (RAS) could be involved in the mechanism of gastric integrity and gastroprotection. After renin stimulation, the circulating angiotensin I is converted to angiotensin II (ANG II) by the activity of the Angiotensin Converting Enzyme (ACE). The ANG II acting via its binding to two major receptor subtypes the ANG type 1 (AT1) and type 2 (AT2) has been shown be activated during stress and to contribute to the pathogenesis of cold stress- and ischemia-reperfusion-induced gastric lesions. All bioactive angiotensin peptides can be generated not only in systemic circulation, but also locally in several tissues and organs. Recently the new functional components of RAS, such as Ang-(1-7), Ang IV, Ang-(1-12) and novel pathways ACE2 have been described suggesting the gastroprotective role for the novel ANG II metabolite, Ang-(1-7). The fact that Ang-(1-7) is produced in excessive amounts in the gastric mucosa of rodents and that pretreatment by Ang-(1-7) exhibits a potent gastroprotective activity against the gastric lesions induced by cold

  17. Short-term effect of dietary yeast nucleotide supplementation on small intestinal enzyme activities, bacterial populations and metabolites and ileal nutrient digestibilities in newly weaned pigs.

    PubMed

    Sauer, N; Eklund, M; Roth, S; Rink, F; Jezierny, D; Bauer, E; Mosenthin, R

    2012-08-01

    In previous studies, dietary nucleotides have been shown to improve performance in single-stomached animals by promoting the renewal of small intestine epithelial cells and by influencing the activity and composition of the microbial community in the digestive tract. The present experiment was carried out with 12 barrows weaned at the age of 18 days and fitted with a simple T-cannula at the distal ileum. To determine short-term effects of dietary yeast nucleotides, the piglets received a grain-soybean meal-based basal diet with or without supplementation of 1 g/kg of a dried yeast product containing free nucleotides. Dietary supplementation with yeast did not affect bacterial numbers in the ileum as well as ileal concentrations of individual short-chain fatty acids (SCFA), total SCFA and total lactic acid (p > 0.05). Moreover, there was no effect of supplemental yeast nucleotides on ileal α-amylase, leucine amino peptidase, maltase and lactase activities (p > 0.05), as well as on ileal dry matter, crude protein and crude fibre digestibilities (p > 0.05). In conclusion, short-term supplementation with dietary yeast nucleotides did not affect microbial metabolite concentrations, bacterial numbers and enzyme activities in the ileal digesta as well as ileal nutrient digestibilities of newly weaned pigs. PMID:21797935

  18. A NOVEL METABOLIC ACTIVATION PATHWAY FOR POLYCYCLIC AROMATIC HYDROCARBONS: REACTIVE OXYGEN SPECIES-MEDIATED DNA DAMAGE AND MORPHOLOGICAL CELL TRANSFORMATION IN MOUSE EMBRYO CELLS BY K-REGION DIOL METABOLITES

    EPA Science Inventory

    Benzo[ a ]pyrene (BP) is a well-studied polycyclic aromatic hydrocarbon (P AH) .Many
    mechanisms have been suggested to explain its carcinogenic activity, yet many questions still
    remain. K-region dihydrodiols (diols) ofPAHs are common metabolites and some are genotoxic. W...

  19. Succinyl-5-aminoimidazole-4-carboxamide-1-ribose 5'-Phosphate (SAICAR) Activates Pyruvate Kinase Isoform M2 (PKM2) in Its Dimeric Form.

    PubMed

    Yan, Ming; Chakravarthy, Srinivas; Tokuda, Joshua M; Pollack, Lois; Bowman, Gregory D; Lee, Young-Sam

    2016-08-23

    Human pyruvate kinase isoform M2 (PKM2) is a glycolytic enzyme isoform implicated in cancer. Malignant cancer cells have higher levels of dimeric PKM2, which is regarded as an inactive form of tetrameric pyruvate kinase. This perceived inactivity has fueled controversy about how the dimeric form of pyruvate kinase might contribute to cancer. Here we investigate enzymatic properties of PKM2(G415R), a variant derived from a cancer patient, which we show by size-exclusion chromatography and small-angle X-ray scattering to be a dimer that cannot form a tetramer in solution. Although PKM2(G415R) binds to fructose 1,6-bisphosphate (FBP), unlike the wild type this PKM2 variant shows no activation by FBP. In contrast, PKM2(G415R) is activated by succinyl-5-aminoimidazole-4-carboxamide-1-ribose 5'-phosphate (SAICAR), an endogenous metabolite that we previously showed correlates with an increased level of cell proliferation and promotes protein kinase activity of PKM2. Our results demonstrate an important and unexpected enzymatic activity of the PKM2 dimer that likely has a key role in cancer progression. PMID:27481063

  20. Metabolism and metabolites of polychlorinated biphenyls (PCBs)

    PubMed Central

    Grimm, FA; Hu, D; Kania-Korwel, I; Lehmler, HJ; Ludewig, G; Hornbuckle, KC; Duffel, MW; Bergman, A; Robertson, LW

    2015-01-01

    The metabolism of polychlorinated biphenyls (PCBs) is complex and has an impact on toxicity and thereby assessment of PCB risks. A large number of reactive and stable metabolites are formed in the processes of biotransformation in biota in general and in humans in particular. The aim of this document is to provide an overview of PCB metabolism and to identify metabolites of concern and their occurrence. Emphasis is given to mammalian metabolism of PCBs and their hydroxyl, methylsulfonyl, and sulfated metabolites, especially those that persist in human blood. Potential intracellular targets and health risks are also discussed. PMID:25629923

  1. Antileishmanial Metabolites from Geosmithia langdonii

    PubMed Central

    2015-01-01

    Antileishmanial bioassay guided fractionation of Geosmithia langdonii has resulted in the isolation and identification of two new compounds (1 and 2) together with 10 known compounds (3–12). The structures of the isolated metabolites were elucidated based on comprehensive 1D and 2D NMR spectroscopic data as well as mass spectrometry. The absolute configuration at C4, C5, and C6 of 2 was determined as R using a modified Mosher esterification method and NOESY correlations. The extracts and the isolated metabolites were evaluated for their antileishmanial activities. Compounds 3, 9, 11, and 12 were found to be active against Leishmania donovani with IC50 values of 6.9, 3.3, 8.5, and 9.2 μM, respectively, while compounds 1, 5, and 10 showed lower activities against L. donovani with IC50 values of 13.0, 47.3, and 34.0 μM, respectively. PMID:25084548

  2. Profiling a gut microbiota-generated catechin metabolite's fate in human blood cells using a metabolomic approach.

    PubMed

    Mülek, Melanie; Fekete, Agnes; Wiest, Johannes; Holzgrabe, Ulrike; Mueller, Martin J; Högger, Petra

    2015-10-10

    The microbial catechin metabolite δ-(3,4-dihydroxy-phenyl)-γ-valerolactone (M1) has been found in human plasma samples after intake of maritime pine bark extract (Pycnogenol). M1 has been previously shown to accumulate in endothelial and blood cells in vitro after facilitated uptake and to exhibit anti-inflammatory activity. The purpose of the present research approach was to systematically and comprehensively analyze the metabolism of M1 in human blood cells in vitro and in vivo. A metabolomic approach that had been successfully applied for drug metabolite profiling was chosen to detect 19 metabolite peaks of M1 which were subsequently further analyzed and validated. The metabolites were categorized into three levels of identification according to the Metabolomics Standards Initiative with six compounds each confirmed at levels 1 and 2 and seven putative metabolites at level 3. The predominant metabolites were glutathione conjugates which were rapidly formed and revealed prolonged presence within the cells. Although a formation of an intracellular conjugate of M1 and glutathione (M1-GSH) was already known two GSH conjugate isomers, M1-S-GSH and M1-N-GSH were observed in the current study. Additionally detected organosulfur metabolites were conjugates with oxidized glutathione and cysteine. Other biotransformation products constituted the open-chained ester form of M1 and a methylated M1. Six of the metabolites determined in in vitro assays were also detected in blood cells in vivo after ingestion of the pine bark extract by two volunteers. The present study provides the first evidence that multiple and structurally heterogeneous polyphenol metabolites can be generated in human blood cells. The bioactivity of the M1 metabolites and their contribution to the previously determined anti-inflammatory effects of M1 now need to be elucidated. PMID:26025814

  3. The Significance of Lichens and Their Metabolites

    NASA Astrophysics Data System (ADS)

    Huneck, S.

    Lichens, symbiontic organisms of fungi and algae, synthesize numerous metabolites, the "lichen substances," which comprise aliphatic, cycloaliphatic, aromatic, and terpenic compounds. Lichens and their metabolites have a manifold biological activity: antiviral, antibiotic, antitumor, allergenic, plant growth inhibitory, antiherbivore, and enzyme inhibitory. Usnic acid, a very active lichen substance is used in pharmaceutical preparations. Large amounts of Pseudevernia furfuracea and Evernia prunastri are processed in the perfume industry, and some lichens are sensitive reagents for the evaluation of air pollution.

  4. Primary, secondary metabolites, photosynthetic capacity and antioxidant activity of the Malaysian Herb Kacip Fatimah (Labisia Pumila Benth) exposed to potassium fertilization under greenhouse conditions.

    PubMed

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E; Karimi, Ehsan; Ghasemzadeh, Ali

    2012-01-01

    A randomized complete block design was used to characterize the relationship between production of total phenolics, flavonoids, ascorbic acid, carbohydrate content, leaf gas exchange, phenylalanine ammonia-lyase (PAL), soluble protein, invertase and antioxidant enzyme activities (ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) in Labisia pumila Benth var. alata under four levels of potassium fertilization experiments (0, 90, 180 and 270 kg K/ha) conducted for 12 weeks. It was found that the production of total phenolics, flavonoids, ascorbic acid and carbohydrate content was affected by the interaction between potassium fertilization and plant parts. As the potassium fertilization levels increased from 0 to 270 kg K/ha, the production of soluble protein and PAL activity increased steadily. At the highest potassium fertilization (270 kg K/ha) L. pumila exhibited significantly higher net photosynthesis (A), stomatal conductance (g(s)), intercellular CO(2) (C(i)), apparent quantum yield (ξ) and lower dark respiration rates (R(d)), compared to the other treatments. It was found that the production of total phenolics, flavonoids and ascorbic acid are also higher under 270 kg K/ha compared to 180, 90 and 0 kg K/ha. Furthermore, from the present study, the invertase activity was also found to be higher in 270 kg K/ha treatment. The antioxidant enzyme activities (APX, CAT and SOD) were lower under high potassium fertilization (270 kg K/ha) and have a significant negative correlation with total phenolics and flavonoid production. From this study, it was observed that the up-regulation of leaf gas exchange and downregulation of APX, CAT and SOD activities under high supplementation of potassium fertilizer enhanced the carbohydrate content that simultaneously increased the production of L. pumila secondary metabolites, thus increasing the health promoting effects of this plant. PMID:23203128

  5. Primary, Secondary Metabolites, Photosynthetic Capacity and Antioxidant Activity of the Malaysian Herb Kacip Fatimah (Labisia Pumila Benth) Exposed to Potassium Fertilization under Greenhouse Conditions

    PubMed Central

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z. E.; Karimi, Ehsan; Ghasemzadeh, Ali

    2012-01-01

    A randomized complete block design was used to characterize the relationship between production of total phenolics, flavonoids, ascorbic acid, carbohydrate content, leaf gas exchange, phenylalanine ammonia-lyase (PAL), soluble protein, invertase and antioxidant enzyme activities (ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) in Labisia pumila Benth var. alata under four levels of potassium fertilization experiments (0, 90, 180 and 270 kg K/ha) conducted for 12 weeks. It was found that the production of total phenolics, flavonoids, ascorbic acid and carbohydrate content was affected by the interaction between potassium fertilization and plant parts. As the potassium fertilization levels increased from 0 to 270 kg K/ha, the production of soluble protein and PAL activity increased steadily. At the highest potassium fertilization (270 kg K/ha) L. pumila exhibited significantly higher net photosynthesis (A), stomatal conductance (gs), intercellular CO2 (Ci), apparent quantum yield (ξ) and lower dark respiration rates (Rd), compared to the other treatments. It was found that the production of total phenolics, flavonoids and ascorbic acid are also higher under 270 kg K/ha compared to 180, 90 and 0 kg K/ha. Furthermore, from the present study, the invertase activity was also found to be higher in 270 kg K/ha treatment. The antioxidant enzyme activities (APX, CAT and SOD) were lower under high potassium fertilization (270 kg K/ha) and have a significant negative correlation with total phenolics and flavonoid production. From this study, it was observed that the up-regulation of leaf gas exchange and downregulation of APX, CAT and SOD activities under high supplementation of potassium fertilizer enhanced the carbohydrate content that simultaneously increased the production of L. pumila secondary metabolites, thus increasing the health promoting effects of this plant. PMID:23203128

  6. Comparison of in vitro hormone activities of novel flame retardants TBB, TBPH and their metabolites TBBA and TBMEPH using reporter gene assays.

    PubMed

    Klopčič, Ivana; Skledar, Darja Gramec; Mašič, Lucija Peterlin; Dolenc, Marija Sollner

    2016-10-01

    The anti-androgenic and anti-thyroid hormonal activities of the two novel brominated flame retardants, TBB and TBPH and of their metabolites TBBA and TBMEPH have been compared using the luciferase reporter gene assays. Only the parent compounds TBB and TBPH exhibited anti-glucocorticoid activity with IC50 values of 1.9 μM and 0.3 μM. Furthermore, mode of action for these two compounds is by direct competing to the glucocorticoid receptor (GR) with IC50 values of 0.03 μM and 0.002 μM. All four tested compounds possess anti-androgenic and anti-thyroid hormonal activities, without agonist activities on the respective receptors. Anti-androgenic activities with IC50 values of 43.5 μM, 0.1 μM, 47.5 μM and 1.3 μM were found for TBB, TBPH, TBBA and TBMEPH. The anti-thyroid hormonal IC50 values of 37.5 μM, 0.1 μM, 22.8 μM and 32.3 μM for TBB, TBPH, TBBA and TBMEPH, together with the above quoted results, indicate that metabolism can modify anti-androgenic, anti-glucocorticoid and anti-thyroid hormonal effects of these novel brominated flame retardants. Furthermore, the parent flame retardants are shown to be able to disrupt the function of the GR as antagonists by direct competition to the receptor. PMID:27380226

  7. 75 FR 30098 - Reports, Forms and RecordKeeping Requirements; Agency Information Collection Activity Under OMB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... to help States enhance motorcyclist safety training and motorcyclist awareness programs. To qualify... National Highway Traffic Safety Administration Reports, Forms and RecordKeeping Requirements; Agency Information Collection Activity Under OMB Review AGENCY: National Highway Traffic Safety Administration,...

  8. 78 FR 26766 - Commission Information Collection Activities (FERC Form 580); Comment Request; Revision

    Federal Register 2010, 2011, 2012, 2013, 2014

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  9. 76 FR 52014 - Agency Information Collection Activities: Applicant Information Form (1-783)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-19

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  10. 3,4-Dihydroxyphenylacetic acid, a microbiota-derived metabolite of quercetin, attenuates acetaminophen (APAP)-induced liver injury through activation of Nrf-2.

    PubMed

    Xue, Huiting; Xie, Wenyan; Jiang, Zhihui; Wang, Meng; Wang, Jian; Zhao, Hongqiong; Zhang, Xiaoying

    2016-10-01

    1. Acetaminophen (APAP) overdose leads to severe hepatotoxicity. 3,4-dihydroxyphenylacetic acid (DOPAC) is a scarcely studied microbiota-derived metabolite of quercetin. The aim of this study was to determine the protective effect of DOPAC against APAP-induced liver injury. 2. Mice were treated intragastrically with DOPAC (10, 20 or 50 mg/kg) for 3 days before APAP (300 mg/kg) injection. APAP alone caused increase in serum aminotransferase levels and changes in hepatic histopathology. APAP also promoted oxidative stress by increasing lipid peroxidation and decreasing anti-oxidant enzyme activities. These events led to hepatocellular necrosis and reduced liver function. DOPAC increased nuclear factor erythroid 2-related factor 2 (Nrf-2) translocation to the nucleus and enhanced the expression of phase II enzymes and anti-oxidant enzymes, and thereby reduced APAP hepatotoxicity and enhanced anti-oxidant ability. 3. Our data provide evidence that DOPAC protected the liver against APAP-induced injury, which is involved in Nrf-2 activation, implying that DOPAC can be considered as a potential natural hepatoprotective agent. PMID:26931552

  11. A77 1726, the active metabolite of leflunomide, attenuates lupus nephritis by promoting the development of regulatory T cells and inhibiting IL-17-producing double negative T cells.

    PubMed

    Qiao, Guilin; Yang, Lifen; Li, Zhenping; Williams, James W; Zhang, Jian

    2015-04-01

    Lupus nephritis (LN) is a challenging problem that affects 50% of patients with systemic lupus erythematosus (SLE) without effective therapy. Here, we report that A77 1726, the active metabolite of leflunomide, effectively inhibits development of LN and attenuates the generalized autoimmune features. A77 1726 suppresses the expansion of double negative (DN) T cells, and inhibits T and B cell activation. Intriguingly, A77 1726 treatment significantly increases CD4(+)Foxp3(+) regulatory T cells but suppresses potential "pathogenic" IL-17-producing DN T cells in lymph nodes. In vitro experiment shows that A77 1726 potentiates the conversion of naive CD4(+)CD25(-) T cells into CD4(+)CD25(+)Foxp3(+) inducible regulatory T cells (iTregs) by inhibiting Akt. Taken together, our data indicate that the therapeutic effects of A77 1726 in murine LN are mediated, at least in part, by augmenting iTregs which suppress pathogenic IL-17-producing DN T cells through an Akt-dependent mechanism. PMID:25638413

  12. Seven New and Two Known Lipopeptides as well as Five Known Polyketides: The Activated Production of Silent Metabolites in a Marine-Derived Fungus by Chemical Mutagenesis Strategy Using Diethyl Sulphate

    PubMed Central

    Wu, Chang-Jing; Li, Chang-Wei; Cui, Cheng-Bin

    2014-01-01

    AD-2-1 is an antitumor fungal mutant obtained by diethyl sulfate mutagenesis of a marine-derived Penicillium purpurogenum G59. The G59 strain originally did not produce any metabolites with antitumor activities in MTT assays using K562 cells. Tracing newly produced metabolites under guidance of MTT assay and TLC analysis by direct comparison with control G59 extract, seven new (1–7) and two known (8–9) lipopeptides were isolated together with five known polyketides 10–14 from the extract of mutant AD-2-1. Structures of the seven new compounds including their absolute configurations were determined by spectroscopic and chemical evidences and named as penicimutalides A–G (1–7). Seven known compounds were identified as fellutamide B (8), fellutamide C (9), 1′-O-methylaverantin (10), averantin (11), averufin (12), nidurufin (13), and sterigmatocystin (14). In the MTT assay, 1–14 inhibited several human cancer cell lines to varying extents. All the bioassays and HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses demonstrated that the production of 1–14 in the mutant AD-2-1 was caused by the activated production of silent metabolites in the original G59 fungal strain. Present results provided additional examples for effectiveness of the chemical mutagenesis strategy using diethyl sulphate mutagenesis to discover new compounds by activating silent metabolites in fungal isolates. PMID:24686557

  13. 76 FR 70747 - Agency Information Collection Activities: Form I-90; Revision of a Currently Approved Information...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-15

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-19

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-24

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-10

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  18. 77 FR 21104 - Agency Information Collection Activities: Form I-694, Extension of a Currently Approved...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

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  19. 76 FR 20361 - Agency Information Collection Activities: Form I-694, Extension of a Currently Approved...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

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  1. 76 FR 20362 - Agency Information Collection Activities: Form I-905, Extension of a Currently Approved...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

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    ... information collection was previously published in the Federal Register on June 9, 2010, at 75 FR 32799... asked or required to respond, as well as a brief abstract: